bims-amsmem 2022-06-26 papers

bims-amsmem

Biomed News

on AMPK signaling mechanism in energy metabolism

Issue of 2022‒06‒26
34 papers selected by
Dipsikha Biswas, Københavns Universitet

AMPK activates the Nrf2-Keap1 pathway to govern dendrite pruning via insulin pathway in Drosophila.
HM-chromanone suppresses hepatic glucose production via activation of AMP-activated protein kinase in HepG2 cell.
Metformin reduces myogenic contracture and myofibrosis induced by rat knee joint immobilization via AMPK-mediated inhibition of TGF-β1/Smad signaling pathway.
Erratum: MicroRNA-506-3p targets SIRT1 and suppresses AMPK pathway activation to promote hepatic steatosis.
Liver kinase B1 (LKB1) in murine erythroid progenitors modulates erythropoietin setpoint in association with maturation control.
Combination of mTOR inhibitor PP242 and AMPK activator metformin exerts enhanced inhibitory effects on colorectal carcinoma cells in vitro by blocking multiple kinase pathways.
Glucose restriction induces ROS-AMPK-mediated CTR1 expression and increases cisplatin efficiency in NSCLC.
Glycogen phosphorylase isoform regulation of glucose and Energy Sensor expression in male versus female rat hypothalamic astrocyte primary cultures.
Orchestrated Action of AMPK Activation and Combined VEGF/PD-1 Blockade with Lipid Metabolic Tunning as Multi-Target Therapeutics against Ovarian Cancers.
Quinacrine is active in preclinical models of glioblastoma through suppressing angiogenesis, inducing oxidative stress and activating AMPK.
PF-06409577 inhibits renal cyst progression by concurrently inhibiting the mTOR pathway and CFTR channel activity.
Polydatin attenuates chronic alcohol consumption-induced cardiomyopathy through a SIRT6-dependent mechanism.
Rottlerin Stimulates Exosome/Microvesicle Release Via the Increase of Ceramide Levels Mediated by Ampk in an In Vitro Model of Intracellular Lipid Accumulation.
Resveratrol Induces Autophagy and Apoptosis in Non-Small-Cell Lung Cancer Cells by Activating the NGFR-AMPK-mTOR Pathway.
Corrigendum to: "Double knockout of Akt2 and AMPK accentuates high fat diet-induced cardiac anomalies through a cGAS-STING-mediated mechanism" [Biochim Biophys Acta Mol. Basis Dis. 1866 2020; (10): 165855. PMID: 32512189].
Short-term moderate caloric restriction in a high-fat diet alleviates obesity via AMPK/SIRT1 signaling in white adipocytes and liver.
Pentamethylquercetin Regulates Lipid Metabolism by Modulating Skeletal Muscle-Adipose Tissue Crosstalk in Obese Mice.
The Ameliorative Effect of Empagliflozin in Vigabatrin-Induced Cerebellar/Neurobehavioral Deficits: Targeting mTOR/AMPK/SIRT-1 Signaling Pathways.
CTRP9 overexpression attenuates palmitic acid-induced inflammation, apoptosis and impaired migration in HTR8/SVneo cells through AMPK/SREBP1c signaling.
IRW (Isoleucine-Arginine-Tryptophan) Improves Glucose Tolerance in High Fat Diet Fed C57BL/6 Mice via Activation of Insulin Signaling and AMPK Pathways in Skeletal Muscle.
Characterization of Early Alzheimer's Disease-Like Pathological Alterations in Non-Human Primates with Aging: A Pilot Study.
Alpinia katsumadai Hayata induces growth inhibition and autophagy‑related apoptosis by regulating the AMPK and Akt/mTOR/p70S6K signaling pathways in cancer cells.
[Cordycepin inhibits the proliferation and migration of human gastric cancer cells by suppressing lipid metabolism via AMPK and MAPK activation].
Bisdemethoxycurcumin inhibits VEGF-induced HUVECs proliferation, migration and invasion through AMPK/mTOR pathway-dependent autophagy activation and cell cycle arrest.
Metformin protects against ethanol-induced liver triglyceride accumulation by the LKB1/AMPK/ACC pathway.
Joint Transcriptome and Metabolome Analysis Prevails the Biological Mechanisms Underlying the Pro-Survival Fight in In Vitro Heat-Stressed Granulosa Cells.
Potential Application of Gambogic Acid for Retarding Renal Cyst Progression in Polycystic Kidney Disease.
PTP1B inhibition ameliorates inflammatory injury and dysfunction in ox-LDL-induced HUVECs by activating the AMPK/SIRT1 signaling pathway via negative regulation of KLF2.
Adiponectin Ameliorates GMH-Induced Brain Injury by Regulating Microglia M1/M2 Polarization Via AdipoR1/APPL1/AMPK/PPARγ Signaling Pathway in Neonatal Rats.
Abscisic Acid Improves Insulin Action on Glycemia in Insulin-Deficient Mouse Models of Type 1 Diabetes.
Activation of AMPK/miR-181b Axis Alleviates Endothelial Dysfunction and Vascular Inflammation in Diabetic Mice.
The therapeutic activities of metformin: Focus on the Nrf2 signaling pathway and oxidative stress amelioration.
The Activated AMPK/mTORC2 Signaling Pathway Associated with Oxidative Stress in Seminal Plasma Contributes to Idiopathic Asthenozoospermia.
Compositions and Functions of Mitochondria-Associated Endoplasmic Reticulum Membranes and Their Contribution to Cardioprotection by Exercise Preconditioning.

Development. 2022 Jun 23. pii: dev.200536. [Epub ahead of print]

AMPK activates the Nrf2-Keap1 pathway to govern dendrite pruning via insulin pathway in Drosophila.

Liang Yuh Chew, Jianzheng He, Jack Jing Lin Wong, Sheng Li, Fengwei Yu.

  During Drosophila metamorphosis, dendritic arborization sensory neurons ddaCs selectively prune their larval dendrites in response to the steroid hormone ecdysone signaling. The Nrf2-Keap1 pathway acts downstream of ecdysone signaling to promote proteasomal degradation and thereby dendrite pruning. However, how Nrf2-Keap1 pathway is activated remains largely unclear. Here, we identify that the metabolic regulator AMP-activated protein kinase (AMPK) plays a cell-autonomous role in dendrite pruning. Importantly, AMPK is required for both Mical/Headcase expression and activation of Nrf2-Keap1 pathway. We demonstrate a novel pathway in which AMPK promotes Nrf2-Keap1 pathway and dendrite pruning partly via inhibition of insulin pathway. Moreover, the AMPK-insulin pathway is required for ecdysone signaling to activate Nrf2-Keap1 pathway during dendrite pruning. Overall, this study reveals an important mechanism whereby ecdysone signaling activates Nrf2-Keap1 pathway via the AMPK-insulin pathway to promote dendrite pruning, and further suggests that during the nonfeeding prepupal stage the metabolic alterations lead to activation of Nrf2-Keap1 pathway and dendrite pruning.

Keywords:  AMPK kinase; Dendrite pruning; Ecdysone signaling; Insulin pathway; Metamorphosis; Nrf2-Keap1 pathway

DOI:  https://doi.org/10.1242/dev.200536
Eur J Pharmacol. 2022 Jun 16. pii: S0014-2999(22)00369-7. [Epub ahead of print] 175108

HM-chromanone suppresses hepatic glucose production via activation of AMP-activated protein kinase in HepG2 cell.

Jae Eun Park, Ji Sook Han.

  We investigated whether (E)-5-hydroxy-7-methoxy-3-(2-hydroxybenzyl)-4-chromanone (HM-chromanone) could suppress the transcription factors expression and enzymes involved in glucose production by activating AMPK in hepatocytes. HepG2 cells were treated with a medium containing HM-chromanone (5-100 μM), compound C (10 μM) and insulin (100 nM). Glucose production and glycogen synthesis assay were determined using a glucose assay kit and glycogen assay kit, respectively. Activities of AMP-activated protein kinase (AMPK), acetyl CoA carboxylase (ACC), cAMP response element-binding protein (CREB), PPAR coactivator-1α (PGC1α), CREB-regulated transcription coactivator 2 (CRTC2), Glycogen synthase kinase (GSK3β), Phosphoenolpyruvate carboxykinase (PEPCK), glycogen synthase (GS), Glucose 6-phosphatase (G6pase) and β-actin were determined by Western blot analysis. HM-chromanone significantly inhibited hepatic glucose production and increased glycogen synthesis by activating glycogen synthase. HM-chromanone induced the phosphorylation of CRTC2 and GSK-3β by phosphorylating AMPK in HepG2 cells, which was confirmed by compound C. Furthermore, it significantly decreased the phosphorylation of CREB in a time- and concentration-dependent manner, and the effect was reversed in the presence of compound C. Therefore, the complex formation of CRTC2 and CREB was inhibited. HM-chromanone inhibited the expression of PGC-1α, PEPCK, and G6Pase genes involved in production of hepatic glucose. The results showed that HM-chromanone activates AMPK in a time and concentration dependent manner, thus suppressing hepatic glucose production and increasing glycogen synthesis in HepG2 cells.

Keywords:  AMPK; HM-Chromanone; HepG2 cell; Hepatic glucose production; Portulaca oleracea L.

DOI:  https://doi.org/10.1016/j.ejphar.2022.175108
Connect Tissue Res. 2022 Jun 20. 1-14

Metformin reduces myogenic contracture and myofibrosis induced by rat knee joint immobilization via AMPK-mediated inhibition of TGF-β1/Smad signaling pathway.

Feng Wang, Chen Xu Zhou, Zhi Zheng, Du Juan Li, Wen Li, Yun Zhou.

  PURPOSE: The two structural components contributing to joint contracture formation are myogenic and arthrogenic contracture, and myofibrosis is an important part of myogenic contracture. Myofibrosis is a response to long-time immobilization and is described as a condition with excessive deposition of endomysial and perimysial connective tissue components in skeletal muscle. The purpose of this study was to confirm whether metformin can attenuate the formation of myogenic contracture and myofibrosis through the phosphorylation level of adenosine monophosphate-activated protein kinase (AMPK) and inhabitation of subsequent transforming growth factor beta (TGF-β) 1/Smad signaling pathway.MATERIALS AND METHODS: An immobilized rat model was used to determine whether metformin could inhibit myogenic contracture and myofibrosis. The contents of myogenic contracture of knee joint was calculated by measuring instrument of range of motion (ROM), and myofibrosis of rectus femoris were determined by ultrasound shear wave elastography and Masson staining. Protein expression of AMPK and subsequent TGF-β1/Smad signaling pathway were determined by western blot. Subsequently, Compound C, a specific AMPK inhibitor, was used to further clarify the role of the AMPK-mediated inhibition of TGF-β1/Smad signaling pathway.
RESULTS: We revealed that the levels of myogenic contracture and myofibrosis were gradually increased during immobilization, and overexpression of TGF-β1-induced formation of myofibrosis by activating Smad2/3 phosphorylation. Activation of AMPK by metformin suppressed overexpression of TGF-β1 and TGF-β1-induced Smad2/3 phosphorylation, further reducing myogenic contracture and myofibrosis during immobilization. In contrast, inhibition of AMPK by Compound C partially counteracted the inhibitory effect of TGF-β1/Smad signaling pathway by metformin.
CONCLUSION: Notably, we first illustrated the therapeutic effect of metformin through AMPK-mediated inhibition of TGF-β1/Smad signaling pathway in myofibrosis, which may provide a new therapeutic strategy for myogenic contracture.

Keywords:  AMPK; Metformin; TGF-β1/Smad signaling pathway; myofibrosis; myogenic contracture

DOI:  https://doi.org/10.1080/03008207.2022.2088365
Exp Ther Med. 2022 Jul;24(1): 463

Erratum: MicroRNA-506-3p targets SIRT1 and suppresses AMPK pathway activation to promote hepatic steatosis.

Liang-Kai Hu, Jian-Qing Chen, Hao Zheng, Yuan-Ping Tao, Yuan Yang, Xuan-Fu Xu.

[This corrects the article DOI: 10.3892/etm.2021.10865.].

DOI: https://doi.org/10.3892/etm.2022.11390
Blood Cells Mol Dis. 2022 Jun 11. pii: S1079-9796(22)00045-6. [Epub ahead of print]97 102688

Liver kinase B1 (LKB1) in murine erythroid progenitors modulates erythropoietin setpoint in association with maturation control.

Zollie White, Alejandro A Gru, Adam N Goldfarb.

  Erythropoiesis is a tightly regulated process. It is stimulated by decreased oxygen in circulation, which leads to the secretion of the hormone erythropoietin (Epo) by the kidneys. An additional layer of control involves the coordinated sensing and use of nutrients. Much cellular machinery contributes to sensing and responding to nutrient status in cells, and one key participant is the kinase LKB1. The current study examines the role of LKB1 in erythropoiesis using a murine in vivo and ex vivo conditional knockout system. In vivo analysis showed erythroid loss of LKB1 to be associated with a robust increase in serum Epo and mild reticulocytosis. Despite these abnormalities, no evidence of anemia or hemolysis was found. Further characterization using an ex vivo progenitor culture assay demonstrated accelerated erythroid maturation in the LKB1-deficient cells. Based on pharmacologic evidence, this phenotype appeared to result from impaired AMP-activated protein kinase (AMPK) signaling downstream of LKB1. These findings reveal a role for LKB1 in fine-tuning Epo-driven erythropoiesis in association with maturational control.

Keywords:  AMPK; Erythropoiesis; LKB1; Maturation

DOI:  https://doi.org/10.1016/j.bcmd.2022.102688
J Chemother. 2022 Jun 22. 1-11

Combination of mTOR inhibitor PP242 and AMPK activator metformin exerts enhanced inhibitory effects on colorectal carcinoma cells in vitro by blocking multiple kinase pathways.

Cuicui Sun, Xiaoyan Yang, Zhi Jin, Zuhua Gao.

  The second-generation mammalian target of rapamycin (mTOR) inhibitor PP242 has demonstrated limited success in some rapamycin-insensitive tumours. We examined the therapeutic potential of combining PP242 with adenosine 50- monophosphate-activated protein kinase (AMPK) activator metformin, using a panel of colorectal carcinoma (CRC) cell lines. We found that the PP242 and metformin combination enhanced the suppression of CRC cell proliferation, colony formation, and cancer cell apoptosis induction. The effect of this combination was observed on AMPK phosphorylation. Western blotting showed that PP242 inhibited mTORC1 activation, as indicated by the reduced expression of its major substrate p-S6K1 and the partially reduced phosphorylation of eIF4E-binding protein 1 (4E-BP1). The inhibition of mTORC2-mediated AKT phosphorylation at Ser 473 (AKT Ser473) was transient and occurred in the first few hours of PP242 treatment; metformin exposure decreased the PP242 activity, counteracting AKT activation. We further demonstrated that this was related to direct AMPK-mediated phosphorylation of IRS-1 at Ser789. Thus, the combination of PP242 and metformin completely blocked the activity of both mTORC1 and mTORC2 kinase. This study suggests that this combination could be a more effective strategy for the treatment of CRC.

Keywords:  AMPK activator; PP242; colorectal cancer; combination therapy; mTOR inhibitor; metformin

DOI:  https://doi.org/10.1080/1120009X.2022.2091122
Cancer Lett. 2022 Jun 15. pii: S0304-3835(22)00277-4. [Epub ahead of print]543 215793

Glucose restriction induces ROS-AMPK-mediated CTR1 expression and increases cisplatin efficiency in NSCLC.

Pengpeng Zhang, Bohan Li, Qianfeng Chen, Hui Wang, Qing Feng.

  Cisplatin is one of the principal platinum-based chemotherapeutic agents for many types of cancer, including non-small-cell lung cancer (NSCLC). Copper transporter 1 (CTR1) plays a significant role in increasing cellular cisplatin uptake and sensitivity. The current study found that glucose restriction upregulated AMPK (AMP-activated protein kinase) through reactive oxygen species (ROS) to induce CTR1 expression in NSCLC cells. Direct upregulation of ROS levels also activated AMPK expression. The changes in CTR1 expression were consistent with glucose concentrations and AMPK expression. Feeding a low-carbohydrate ketogenic diet (a glucose restriction diet) to a severe combined immune deficiency (SCID) mouse xenograft model significantly enhanced the efficacy of cisplatin. The tumor size was significantly smaller in the group treated with cisplatin plus the low-carbohydrate ketogenic diet than in the group treated with cisplatin alone. Survival was longer in mice treated with the low-carbohydrate ketogenic diet than in the controls. Mice fed the low-carbohydrate ketogenic diet showed increased expression of CTR1 and AMPK in tumor tissues. These results suggest a novel mechanism whereby glucose restriction induces ROS-AMPK-mediated CTR1 expression in NSCLC, indicating glucose restriction as an effective adjuvant NSCLC therapy.

Keywords:  AMPK; CTR1; Glucose restriction; NSCLC; ROS

DOI:  https://doi.org/10.1016/j.canlet.2022.215793
Mol Cell Endocrinol. 2022 Jun 16. pii: S0303-7207(22)00146-0. [Epub ahead of print] 111698

Glycogen phosphorylase isoform regulation of glucose and Energy Sensor expression in male versus female rat hypothalamic astrocyte primary cultures.

Abdulrahman Alhamyani, Prabhat R Napit, Khaggeswar Bheemanapally, Mostafa M H Ibrahim, Paul W Sylvester, Karen P Briski.

  Astrocyte glycogen constitutes the primary energy fuel reserve in the brain. Current research investigated the novel premise that glycogen turnover governs astrocyte responsiveness to critical metabolic and neurotransmitter (i.e. norepinephrine) regulatory signals in a sex-dimorphic manner. Here, rat hypothalamic astrocyte glycogen phosphorylase (GP) gene expression was silenced by short-interfering RNA (siRNA) to investigate how glycogen metabolism controlled by GP-brain type (GPbb) or GP-muscle type (GPmm) activity affects glucose [glucose transporter-2 (GLUT2)] and energy [5'-AMP-activated protein kinase (AMPK)] biomarker and adrenergic receptor (AR) proteins in each sex. Results show that in the presence of glucose, glycogen turnover is regulated by GPbb in the male or by GPmm in the female, yet in the absence of glucose, glycogen breakdown is controlled by GPbb in each sex. GLUT2 expression is governed by GPmm-mediated glycogen breakdown in glucose-supplied astrocytes of each sex, but glycogenolysis regulates sex-specific glucoprivic GLUT2 up-regulation in the male. GPbb-mediated glycogen disassembly regulates total AMPK and phosphoAMPK levels in male, but not female. During glucoprivation, glycogenolysis up-regulates AMPK content in male astrocytes by GPbb- and GPmm-dependent mechanisms, whereas GPbb-mediated glycogen breakdown inhibits phosphoAMPK expression in female. GPbb and GPmm activity governs alpha2-AR and beta1-AR protein levels in male, but has no effect on these profiles in the female. Outcomes provide novel evidence for sex-specific glycogen regulation of glucose- and energy-sensory protein expression in hypothalamic astrocytes, and identify GP isoforms that mediate such control in each sex. Results also show that glycogen regulation of hypothalamic astrocyte receptivity to norepinephrine is male-specific. Further studies are needed to characterize the molecular mechanisms that underlie sex differences in glycogen control of astrocyte protein expression.

Keywords:  AMPK; Adrenergic receptor; GLUT2; Glycogen; Glycogen phosphorylase; Sex differences

DOI:  https://doi.org/10.1016/j.mce.2022.111698
Int J Mol Sci. 2022 Jun 20. pii: 6857. [Epub ahead of print]23(12):

Orchestrated Action of AMPK Activation and Combined VEGF/PD-1 Blockade with Lipid Metabolic Tunning as Multi-Target Therapeutics against Ovarian Cancers.

Mingo M H Yung, Michelle K Y Siu, Hextan Y S Ngan, David W Chan, Karen K L Chan.

  Ovarian cancer is one of the most lethal gynecological malignancies worldwide, and chemoresistance is a critical obstacle in the clinical management of the disease. Recent studies have suggested that exploiting cancer cell metabolism by applying AMP-activated protein kinase (AMPK)-activating agents and distinctive adjuvant targeted therapies can be a plausible alternative approach in cancer treatment. Therefore, the perspectives about the combination of AMPK activators together with VEGF/PD-1 blockade as a dual-targeted therapy against ovarian cancer were discussed herein. Additionally, ferroptosis, a non-apoptotic regulated cell death triggered by the availability of redox-active iron, have been proposed to be governed by multiple layers of metabolic signalings and can be synergized with immunotherapies. To this end, ferroptosis initiating therapies (FITs) and metabolic rewiring and immunotherapeutic approaches may have substantial clinical potential in combating ovarian cancer development and progression. It is hoped that the viewpoints deliberated in this review would accelerate the translation of remedial concepts into clinical trials and improve the effectiveness of ovarian cancer treatment.

Keywords:  AMPK; PD-1 blockade; VEGF; cancer metabolism; ferroptosis; ovarian cancer; polyunsaturated fatty acids; tumor microenvironment

DOI:  https://doi.org/10.3390/ijms23126857
Toxicol In Vitro. 2022 Jun 17. pii: S0887-2333(22)00118-7. [Epub ahead of print] 105420

Quinacrine is active in preclinical models of glioblastoma through suppressing angiogenesis, inducing oxidative stress and activating AMPK.

Xiaohong Fu, Bo Xiong, Min Zhao, Weifeng Wan, Shaofu Zhang, Xuedong Wu, Jianguo Xu.

  The poor prognosis of glioblastoma requires new innovative treatment strategies. We and others have shown that targeting tumor as well as angiogenesis in glioblastoma are effective therapeutic strategies. In line with these efforts, this work reveals that Quinacrine, an antimalarial drug, is a dual inhibitor of angiogenesis and glioblastoma. Using multiple glioblastoma cell lines, we found that Quinacrine inhibited proliferation and induced apoptosis in these cells, and acted in synergy with Temozolomide. Quinacrine potently inhibited tubular structure formations of glioblastoma microvascular endothelial cell (GMVEC) isolated from glioblastoma patients, especially for early stage tubular structure formation. Although Quinacrine induces apoptosis in GMVEC, the anti-angiogenic activity of Quinacrine is independent of its pro-apoptotic activity in GMVECs. Quinacrine inhibits glioblastoma angiogenesis and growth in vivo, and acts synergistically with Temozolomide in inhibiting glioblastoma growth in mice. Mechanistically, we found that Quinacrine acts on glioblastoma through inducing oxidative stress, impairing mitochondrial function and activating AMP-activated protein kinase (AMPK). Our work is the first to demonstrate the anti-angiogenic activity of Quinacrine. Our findings highlight Quinacrine as an attractive candidate to support treatment of glioblastoma.

Keywords:  AMPK; Glioblastoma angiogenesis; Quinacrine; Synergism

DOI:  https://doi.org/10.1016/j.tiv.2022.105420
FEBS Open Bio. 2022 Jun 24.

PF-06409577 inhibits renal cyst progression by concurrently inhibiting the mTOR pathway and CFTR channel activity.

Limin Su, Haoxing Yuan, Haoran Zhang, Ruoqi Wang, Kequan Fu, Long Yin, Ying Ren, Hongli Liu, Qian Fang, Junqi Wang, Dong Guo.

  Renal cyst development and expansion in autosomal dominant polycystic kidney disease (ADPKD) involves over-proliferation of cyst-lining epithelial cells and excessive cystic fluid secretion. While metformin effectively inhibits renal cyst growth in mouse models of ADPKD it exhibits low potency, and thus an AMPK activator with higher potency is required. Herein, we adopted a drug repurposing strategy to explore the potential of PF-06409577, an adenosine monophosphate-activated protein kinase (AMPK) activator for diabetic nephropathy, in cellular, ex vivo and in vivo models of ADPKD. Our results demonstrated that PF-06409577 effectively down-regulated mammalian target of rapamycin (mTOR) pathway-mediated proliferation of cyst-lining epithelial cells and reduced cystic fibrosis transmembrane conductance regulator (CFTR)-regulated cystic fluid secretion. Overall, our data suggest that PF-06409577 holds therapeutic potential for ADPKD treatment.

Keywords:  ADPKD; AMPK; CFTR; PF-06409577; kidney disease; mTOR; renal cyst

DOI:  https://doi.org/10.1002/2211-5463.13459
Food Funct. 2022 Jun 21.

Polydatin attenuates chronic alcohol consumption-induced cardiomyopathy through a SIRT6-dependent mechanism.

Li-Ming Yu, Xue Dong, Ning Li, Hui Jiang, Ji-Kai Zhao, Yin-Li Xu, Deng-Yue Xu, Xiao-Dong Xue, Zi-Jun Zhou, Yu-Ting Huang, Qiu-Sheng Zhao, Zhi-Shang Wang, Zong-Tao Yin, Hui-Shan Wang.

Polydatin has attracted much attention as a potential cardioprotective agent against ischemic heart disease and diabetic cardiomyopathy. However, the effect and mechanism of polydatin supplementation on alcoholic cardiomyopathy (ACM) are still unknown. This study aimed to determine the therapeutic effect of polydatin against ACM and to explore the molecular mechanisms with a focus on SIRT6-AMP-activated protein kinase (AMPK) signaling and mitochondrial function. The ACM model was established by feeding C57/BL6 mice with an ethanol Lieber-DeCarli diet for 12 weeks. The mice received polydatin (20 mg kg-1) or vehicle treatment. We showed that polydatin treatment not only improved cardiac function but also reduced myocardial fibrosis and dynamin-related protein 1 (Drp-1)-mediated mitochondrial fission, and enhanced PTEN-induced putative kinase 1 (PINK1)-Parkin-dependent mitophagy in alcohol-treated myocardium. Importantly, these beneficial effects were mimicked by SIRT6 overexpression but abolished by the infection of recombinant serotype 9 adeno-associated virus (AAV9) carrying SIRT6-specific small hairpin RNA. Mechanistically, alcohol consumption induced a gradual decrease in the myocardial SIRT6 level, while polydatin effectively activated SIRT6-AMPK signaling and modulated mitochondrial dynamics and mitophagy, thus reducing oxidative stress damage and preserving mitochondrial function. In summary, these data present new information regarding the therapeutic actions of polydatin, suggesting that the activation of SIRT6 signaling may represent a new approach for tackling ACM-related cardiac dysfunction.

DOI: https://doi.org/10.1039/d2fo00966h
Biomedicines. 2022 Jun 03. pii: 1316. [Epub ahead of print]10(6):

Rottlerin Stimulates Exosome/Microvesicle Release Via the Increase of Ceramide Levels Mediated by Ampk in an In Vitro Model of Intracellular Lipid Accumulation.

Yessenia L Molina, David García-Seisdedos, Bohdan Babiy, Milagros Lerma, Javier Martínez-Botas, María J Casarejos, María T Vallejo, Diego Gómez-Coronado, Miguel A Lasunción, Óscar Pastor, Rebeca Busto.

  Exosomes/microvesicles originate from multivesicular bodies that allow the secretion of endolysosome components out of the cell. In the present work, we investigated the effects of rottlerin, a polyphenol, on exosome/microvesicle secretion in a model of intracellular lipid trafficking impairment, and elucidated the mechanism of action. In a model of lipid trafficking impairment in C6 glia cells, rottlerin increased ceramide levels, while decreasing hexosylceramide content. This was accompanied by increased exosome/microvesicle secretion, thereby reducing the concentration of lipids in the endolysosomal compartment. The reduction of hexosylceramide levels by rottlerin was attributed to the increase of β-glucosidase (glucosylceramidase) activity, and the effects of rottlerin were abrogated by β-glucosidase inhibitors such as isofagomine D-tartrate and AMP-deoxynojirimycin. Moreover, treatment with ML-266, a potent activator of the β-glucosidase enzyme, recapitulated the effects of rottlerin on the sphingolipid profile and exosome/microvesicle secretion. Finally, inhibition of AMPK (AMP-activated protein kinase) using compound C prevented both exosome/microvesicle secretion and the elimination of endolysosome lipids, which were promoted by rottlerin. The results showed that the decrease in intracellular lipid deposition induced by rottlerin was mediated by β-glucosidase activation and exosome/microvesicle release via the AMPK pathway. Rottlerin consumption could represent an additional health benefit in lysosomal deposition diseases.

Keywords:  AMPK; ceramide; exosome/microvesicle; intracellular lipid trafficking; lysosomal storage disease; rottlerin; sphingolipid

DOI:  https://doi.org/10.3390/biomedicines10061316
Nutrients. 2022 Jun 10. pii: 2413. [Epub ahead of print]14(12):

Resveratrol Induces Autophagy and Apoptosis in Non-Small-Cell Lung Cancer Cells by Activating the NGFR-AMPK-mTOR Pathway.

Jiaqiao Li, Yameng Fan, Yan Zhang, Yamei Liu, Yan Yu, Mao Ma.

  Resveratrol (RSV) has been reported to induce autophagy and apoptosis in non-small-cell lung cancer A549 cells, and the nerve growth factor receptor (NGFR) regulates autophagy and apoptosis in many other cells. However, the effect of NGFR on autophagy and apoptosis induced by RSV in A549 cells remains unclear. Here, we found that RSV reduced the cell survival rate in time- and concentration-dependent manners, activating autophagy and apoptosis. Lethal autophagy was triggered by RSV higher than 55 μM. The relationship between autophagy and apoptosis depended on the type of autophagy. Specifically, mutual promotion was observed between apoptosis and lethal autophagy. Conversely, cytoprotective autophagy facilitated apoptosis but was unaffected by apoptosis. RSV enhanced NGFR by increasing mRNA expression and prolonging the lifespan of NGFR mRNA and proteins. RSV antagonized the enhanced autophagy and apoptosis caused by NGFR knockdown. As the downstream pathway of NGFR, AMPK-mTOR played a positive role in RSV-induced autophagy and apoptosis. Overall, RSV-induced autophagy and apoptosis in A549 cells are regulated by the NGFR-AMPK-mTOR signaling pathway.

Keywords:  A549 cell line; NGFR-AMPK-mTOR pathway; apoptosis; autophagy; non-small-cell lung cancer; resveratrol

DOI:  https://doi.org/10.3390/nu14122413
Biochim Biophys Acta Mol Basis Dis. 2022 Jun 17. pii: S0925-4439(22)00128-4. [Epub ahead of print]1868(10): 166457

Corrigendum to: "Double knockout of Akt2 and AMPK accentuates high fat diet-induced cardiac anomalies through a cGAS-STING-mediated mechanism" [Biochim Biophys Acta Mol. Basis Dis. 1866 2020; (10): 165855. PMID: 32512189].

Y Gong, G Li, J Tao, N N Wu, M R Kandadi, Y Bi, S Wang, Z Pei, J Ren.

DOI: https://doi.org/10.1016/j.bbadis.2022.166457
Food Nutr Res. 2022 ;66

Short-term moderate caloric restriction in a high-fat diet alleviates obesity via AMPK/SIRT1 signaling in white adipocytes and liver.

Shaohong Zhang, Shuoshuo Sun, Xiao Wei, Mengxiao Zhang, Yu Chen, Xiaodong Mao, Guofang Chen, Chao Liu.

  Background: Obesity is a growing problem for public health worldwide. Calorie restriction (CR) is a safety and effective life intervention to defend against obesity. Short-term moderate CR may be a more favorable strategy against this pathology. However, the mechanisms behind the effects of CR remain to be clarified. Increased energy expenditure in the liver and brown adipose tissue could potentially be manipulated to modulate and improve metabolism in obesity. Moreover, nicotinamide adenine dinucleotide (NAD)-dependent deacetylase sirtuin-1 (SIRT1) and AMP-activated protein kinase (AMPK) are well-characterized metabolic modulators. We aim to explore the anti-obesity effects of short-term moderate CR by improving energy metabolism via the SIRT1/AMPK pathway in white adipocytes and liver in a mouse model of obesity.Methods: Male C57BL/6 mice were randomized into two groups receiving either a standard or a high-fat diet (HFD) for 8 weeks to induce obesity. The HFD-induced obese mice were further randomized into two groups: HFD group or CR group (received 75% of the food eaten by HFD group). Their energy metabolism, white adipose tissue (WAT) contents, hepatic fat deposition, the expression of AMPK, SIRT1, peroxisome proliferators γ-activated receptor coactivator-1α (PGC-1α), nuclear factor kappa B (NF-κB), endothelial nitric oxide synthase (eNOS) in WAT, and hepatic tissues were determined.
Results: After 4 weeks, body weight, total serum cholesterol, fasting blood glucose, and insulin levels were significantly lower in the CR group. Moreover, CR ameliorated hepatocyte steatosis, attenuated white adipogenesis, and increased energy expenditure and expressions of SIRT1, PGC-1α, and phosphorylated AMPK in subcutaneous WAT and the hepatic tissues. In addition, CR reduced the protein levels of NF-κB and increased the eNOS expression.
Conclusion: Short-term moderate CR decreases obesity, increases the thermogenesis, and inhibits inflammation in a mouse model of obesity, probably via the activation of the AMPK/SIRT1 pathway in WAT and liver.

Keywords:  AMPK/SIRT1 pathway; calorie restriction; high-fat diet; obesity

DOI:  https://doi.org/10.29219/fnr.v66.7909
Pharmaceutics. 2022 May 29. pii: 1159. [Epub ahead of print]14(6):

Pentamethylquercetin Regulates Lipid Metabolism by Modulating Skeletal Muscle-Adipose Tissue Crosstalk in Obese Mice.

Jianzhao Wu, Jingxia Du, Zhi Li, Wei He, Min Wang, Manwen Jin, Lei Yang, Hui Liu.

  Irisin is an exercise-induced hormone that regulates lipid metabolism. The present study investigates whether the anti-obesity effect of the natural flavonoid pentamethylquercetin (PMQ) is related to irisin secretion from skeletal muscle in whole animals and cultured cells. Obese mice induced by monosodium glutamate were administered oral PMQ to determine blood irisin level and in vivo parameters of lipid metabolism, and cultured mouse C2C12 myoblasts and 3T3-L1 preadipocytes were employed to investigate the related molecular identities. PMQ increased circulating irisin and decreased bodyweight, insulin, and lipid levels accompanied with increasing brown-like adipocyte formation in obese mice. The brown adipocyte marker uncoupling protein 1 (UCP-1) and other brown-like adipocyte-specific genes and/or markers were increased in mouse white fat tissue, while PMQ treatment reversed the above changes. PMQ also dose-dependently increased the reduced levels of AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), and fibronectin type III domain-containing 5 (FNDC5) signal molecules in obese mice. Interestingly, the irisin level was increased in the culture medium of C2C12 cells treated with PMQ, and the conditioned medium stimulated the brown-like transition of 3T3-L1 preadipocytes with the increased expression of PGC-1α, FNDC5, UCP-1, and other brown-like adipocyte-specific genes. The effects of conditioned culture medium were abolished in C2C12 cells with silenced PGC-1α. On the other hand, PMQ-induced upregulation of PGC-1α and FNDC5 expression was reduced by AMPK inhibitor Compound C in C2C12 cells. Our results demonstrate the novel information that PMQ-induced irisin secretion from skeletal muscle involves the improvement of metabolic dysfunction in obese mice via activating the AMPK/PGC-1α/FNDC5 signal pathway, suggesting that PMQ modulates skeletal muscle-adipose tissue crosstalk and may be a promising drug candidate for treating obesity and obesity-related metabolic diseases.

Keywords:  AMP-activated protein kinase; browning of white adipose tissue; fibronectin type III domain-containing 5; irisin; pentamethylquercetin; peroxisome proliferator-activated receptor-γ coactivator-1α; skeletal muscle

DOI:  https://doi.org/10.3390/pharmaceutics14061159
Molecules. 2022 Jun 07. pii: 3659. [Epub ahead of print]27(12):

The Ameliorative Effect of Empagliflozin in Vigabatrin-Induced Cerebellar/Neurobehavioral Deficits: Targeting mTOR/AMPK/SIRT-1 Signaling Pathways.

Rabab M Amer, Amira Kamel Eltokhy, Rasha Osama Elesawy, Amany Nagy Barakat, Eman Basha, Omnia Safwat Eldeeb, Alshimaa Aboalsoud, Nancy Mohamed Elgharabawy, Radwa Ismail.

  Introduction. Vigabatrin (VGB) is an antiepileptic drug that acts to irreversibly inhibit the γ-aminobutyric acid (GABA) transaminase enzyme, elevating GABA levels. Broad studies have established that long-term treatment and/or high doses of VGB lead to variable visual defects. However, little attention has been paid to its other side effects, especially those demonstrating cerebellar involvement. Sodium glucose-linked co-transporter 2 (SGLT2) inhibitors are antidiabetic agents with protective effects far greater than expected based on their anti-hyperglycemic effect. Method. Our study herein was designed to investigate the possible ameliorative effect of empagliflozin, the SGLT2 inhibitors, in VGB-induced cerebellar toxicity. A total of 40 male Wistar rats were allocated equally into 4 groups: Group I: control group; Group II: VGB group; Group III empagliflozin treated VGB group; and Group IV: empagliflozin treated group. All groups were subjected to the detection of cerebellar messenger RNA gene expression of silent mating type information regulation 2 homolog 1 (SIRT1) and Nucleoporin p62 (P62). Mammalian target of rapamycin (mTOR), adenosine monophosphate-activated protein kinase (AMPK), and beclin1 levels were assessed by the ELISA technique while malondialdehyde (MDA) level and superoxide dismutase (SOD) activity were detected spectrophotometrically. Immuno-histochemical studies, focusing on glial fibrillary acidic protein (GFAP) and S100 were performed, and the optical color density and the mean area percentage of GFAP positive astrocytes and the number of S 100 positive cells were also counted. Results. Following empagliflozin treatment, we documented significant upregulation of both SIRT1 and P62 mRNA gene expression. Additionally, AMPK, Beclin1 levels, and SOD activity were significantly improved, while both mTOR and MDA levels were significantly reduced. Conclusions. We concluded for the first time that empagliflozin efficiently ameliorated the VGB-induced disrupted mTOR/AMPK/SIRT-1 signaling axis with subsequent improvement of the autophagy machinery and mitigation of the oxidative and inflammatory cellular environment, paving the way for an innovative therapeutic potential in managing VGB-induced neurotoxicity.

Keywords:  AMPK; GFAP; SIRT-1; empagliflozin; mTOR; vigabatrin

DOI:  https://doi.org/10.3390/molecules27123659
Exp Ther Med. 2022 Jul;24(1): 459

CTRP9 overexpression attenuates palmitic acid-induced inflammation, apoptosis and impaired migration in HTR8/SVneo cells through AMPK/SREBP1c signaling.

Li Li, Zhongyi Gu, Junjie Zhang.

  Obesity in pregnant mothers often leads to a range of obstetric complications, including miscarriage, pre-eclampsia, gestational hypertension and diabetes. C1q/TNF-related protein 9 (CTRP9) is an adipokine with an anti-inflammatory effect. The aim of the present study was to identify the role of CTRP9 in the pathogenesis of maternal obesity during pregnancy. Following treatment with palmitic acid (PA), HTR8/SVneo cell viability and CTRP9 expression were analyzed using Cell Counting Kit-8 (CCK-8), reverse transcription-quantitative PCR (RT-qPCR) and western blot analyses. The effects of CTRP9 overexpression on cell viability, apoptosis, pro-inflammatory cytokine levels and migration were assessed using CCK-8, TUNEL, RT-qPCR and Transwell assays, respectively. Subsequently, sterol-regulatory element binding protein 1c (SREBP1c) overexpression efficiency was verified using RT-qPCR, and its effects on cell viability, apoptosis, pro-inflammatory cytokines and migration damage were then examined in HTR8/SVneo cells. The results showed that CTRP9 overexpression attenuated the inhibition of cell viability and apoptosis caused by PA in HTR8/SVneo cells, reduced pro-inflammatory cytokine release, improved cell migration and regulated the protein expression level of AMP-activated protein kinase (AMPK)/SREBP1c signaling. In addition, CTRP9 inhibited SREBP1c expression through AMPK signaling, thereby attenuating the inflammation, apoptosis and inhibited migration caused by PA in HTR8/SVneo cells. In brief, CTRP9 protected against inflammation, apoptosis and migration defects in HTR8/SVneo cells exposed to PA treatment through AMPK/SREBP1c signaling, which suggested the potential role of CTRP9 in alleviating the toxicity of PA.

Keywords:  AMPK/SREBP1c signaling; CTRP9; HTR8/SVneo cells; apoptosis; inflammation

DOI:  https://doi.org/10.3892/etm.2022.11386
Biomedicines. 2022 May 26. pii: 1235. [Epub ahead of print]10(6):

IRW (Isoleucine-Arginine-Tryptophan) Improves Glucose Tolerance in High Fat Diet Fed C57BL/6 Mice via Activation of Insulin Signaling and AMPK Pathways in Skeletal Muscle.

Stepheny C de Campos Zani, Myoungjin Son, Khushwant S Bhullar, Catherine B Chan, Jianping Wu.

  IRW (Isoleucine-Arginine-Tryptophan), has antihypertensive and anti-inflammatory properties in cells and animal models and prevents angiotensin-II- and tumor necrosis factor (TNF)-α-induced insulin resistance (IR) in vitro. We investigated the effects of IRW on body composition, glucose homeostasis and insulin sensitivity in a high-fat diet (HFD) induced insulin resistant (IR) model. C57BL/6 mice were fed HFD for 6 weeks, after which IRW was incorporated into the diet (45 or 15 mg/kg body weight (BW)) until week 14. IRW45 (at a dose of 45 mg/kg BW) reduced BW (p = 0.0327), fat mass gain (p = 0.0085), and preserved lean mass of HFD mice (p = 0.0065), concomitant with enhanced glucose tolerance and reduced fasting glucose (p < 0.001). In skeletal muscle, IRW45 increased insulin-stimulated protein kinase B (AKT) phosphorylation (p = 0.0132) and glucose transporter 4 (GLUT4) translocation (p < 0.001). Angiotensin 2 receptor (AT2R) (p = 0.0024), phosphorylated 5'-AMP-activated protein kinase (AMPKα) (p < 0.0124) and peroxisome proliferator-activated receptor gamma (PPARγ) (p < 0.001) were enhanced in skeletal muscle of IRW45-treated mice, as was the expression of genes involved in myogenesis. Plasma angiotensin converting enzyme-2 (ACE2) activity was increased (p = 0.0016). Uncoupling protein-1 in white adipose tissue (WAT) was partially restored after IRW supplementation. IRW improves glucose tolerance and body composition in HFD-fed mice and promotes glucose uptake in skeletal muscle via multiple signaling pathways, independent of angiotensin converting enzyme (ACE) inhibition.

Keywords:  ACE; IRW; bioactive peptides; insulin resistance; obesity

DOI:  https://doi.org/10.3390/biomedicines10061235
J Alzheimers Dis. 2022 Jun 13.

Characterization of Early Alzheimer's Disease-Like Pathological Alterations in Non-Human Primates with Aging: A Pilot Study.

Hannah Jester, Saahj Gosrani, Huiping Ding, Xueyan Zhou, Mei-Chuan Ko, Tao Ma.

  BACKGROUND: Sporadic or late onset Alzheimer's disease (LOAD) is a multifactorial neurodegenerative disease with aging the most known risk factor. Non-human primates (NHPs) may serve as an excellent model to study LOAD because of their close similarity to humans in many aspects including neuroanatomy and neurodevelopment. Recent studies reveal AD-like pathology in old NHPs.OBJECTIVE: In this pilot study, we took advantage of brain samples from 6 Cynomolgus macaques that were divided into two groups: middle aged (average age 14.81 years) and older (average age 19.33 years). We investigated whether AD-like brain pathologies are present in the NHPs.
METHODS: We used immunohistochemical method to examine brain Aβ pathology and neuron density. We applied biochemical assays to measure tau phosphorylation and multiple signaling pathways indicated in AD. We performed electron microscopy experiments to study alterations of postsynaptic density and mitochondrial morphology in the brain of NHPs.
RESULTS: We found multiple AD-like pathological alteration in the prefrontal cortex (but not in the hippocampus) of the older NHPs including tau hyperphosphorylation, increased activity of AMP-activated protein kinase (AMPK), decreased expression of protein phosphatase 2A (PP2A), impairments in mitochondrial morphology, and postsynaptic densities formation.
CONCLUSION: These findings may provide insights into the factors contributing to the development of LOAD, particularly during the early stage transitioning from middle to old age. Future endeavors are warranted to elucidate mechanisms underlying the regional (and perhaps cellular) vulnerability with aging and the functional correlation of such pathological changes in NHPs.

Keywords:  AMPK; Aging; Alzheimer’s disease; mitochondria; non-human primate; synapses

DOI:  https://doi.org/10.3233/JAD-215303
Oncol Rep. 2022 Aug;pii: 142. [Epub ahead of print]48(2):

Alpinia katsumadai Hayata induces growth inhibition and autophagy‑related apoptosis by regulating the AMPK and Akt/mTOR/p70S6K signaling pathways in cancer cells.

Weixiao An, Yuxi Zhang, Honglin Lai, Yangyang Zhang, Hongmei Zhang, Ge Zhao, Minghua Liu, Yang Li, Xiukun Lin, Shousong Cao.

  Alpinia katsumadai Hayata (AKH), a widely used traditional Chinese medicine, exerts various biological functions, including anti‑inflammatory, antioxidant, anti‑microbial and anti‑asthmatic effects. However, studies on its anticancer activity and associated mechanisms are limited. The present study investigated the effects of ethanol extract from AKH on the viability of various human cancer and normal liver LX‑2 cells using Cell Counting Kit‑8 assay. Apoptosis was detected by Hoechst 33342/PI staining and Annexin‑V‑FITC/PI double staining. Autophagy was examined by Ad‑GFP‑LC3B transfection. The association between AKH‑induced autophagy and apoptosis was investigated by pre‑treatment of the cells with the autophagy inhibitors, 3‑methyladenine (3MA) and bafilomycin A1 (Baf‑A1), followed by treatment with AKH. The expression levels of cleaved poly(ADP‑ribose) polymerase (PARP), caspase‑8, caspase‑3, caspase‑9, phosphorylated (p‑)AMP‑activated protein kinase (AMPK), Akt, mTOR and p70S6K were examined using western blot analysis. The in vivo antitumor activity of AKH was investigated in nude mice bearing A549 lung cancer xenografts. The components of AKH were detected by liquid chromatography mass spectrometry‑ion trap‑time‑of‑flight mass spectrometry. The results revealed that AKH significantly inhibited the proliferation of various cancer cells with the half maximal inhibitory concentration (IC50) values of 203‑284 µg/ml; however, its inhibitory effect was much less prominent against normal liver LX‑2 cells with an IC50 value of 395 µg/ml. AKH markedly induced apoptosis and autophagy, and upregulated the protein expression of cleaved‑caspase‑3, caspase‑8, caspase‑9 and cleaved PARP in a concentration‑dependent manner. Of note, the autophagy inhibitors (3MA and Baf‑A1) significantly attenuated its pro‑apoptotic effects on human pancreatic cancer Panc‑28 and lung cancer A549 cells. Furthermore, AKH significantly increased the levels of p‑AMPK, and decreased those of p‑Akt, p‑mTOR and p‑p70S6K in Panc‑28 and A549 cells. AKH markedly inhibited the growth of A549 tumor xenografts in vivo. In addition, a total of nine compounds were detected from AKH. The present study demonstrates that AKH markedly inhibits the growth and induces autophagy‑related apoptosis in cancer cells by regulating the AMPK and Akt/mTOR/p70S6K signaling pathways. AKH and/or its active fractions may thus have potential to be developed as novel anticancer agents for clinical use.

Keywords:  Alpinia katsumadai Hayata; adenosine 5'‑monophosphate‑activated protein kinase; apoptosis; autophagy; serine‑threonine kinase/mammalian target of rapamycin/70‑kDa ribosomal protein S6 kinase signaling pathway

DOI:  https://doi.org/10.3892/or.2022.8353
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi. 2022 Jun;38(6): 513-521

[Cordycepin inhibits the proliferation and migration of human gastric cancer cells by suppressing lipid metabolism via AMPK and MAPK activation].

Xin Zhang, Xuebing Zhou, Ming Gao, You Lyu, Ying Wang, Chunyu Yang, Yingshi Piao, Xiangshan Ren.

Objective To explore the inhibitory effect of cordycepin on the proliferation and migration of gastric cancer cells and its molecular mechanism. Methods MGC-803 cells were treated with 0, 25, 50, 100 μmol/L of cordycepin and HGC-27 cells with 0, 5, 25, 50 μmol/L of cordycepin for 48 hours. The proliferation ability of MGC-803 and HGC-27 cells was detected by MTT assay and EdU assay; the colony formation ability of cells was detected by colony formation assay; both wound healing assay and cell migration assay were applied to detect the cell migration ability of MGC-803 and HGC-27 cells; the chromatin agglutination was detected by Hoechst 33342 staining; the apoptosis of gastric cancer cells was detected by annexin V-FITC/PI double labeling combined with flow cytometry; Western blot was used to measure the protein expression levels of lipid metabolism-related proteins including sterol regulatory element binding transcription factor 1 (SREBF1), fatty acid synthase (FASN), and acetyl coA carboxylase 1 (ACC1), epithelial-mesenchymal transition (EMT)-related proteins including E-cadherin, vimentin, Snail, Slug, matrix metalloproteinase 2 (MMP2), MMP9, AMPK, and phosphorylated AMPK (p-AMPK), MAPK signaling pathway-related proteins including JNK, phosphorylated JNK (p-JNK), p38 MAPK, and p-p38 MAPK, and apoptosis-related proteins including cleaved caspase-9 (c-caspase-9), c-caspase-3, and cleaved poly (ADP-ribose) polymerase (c-PARP). Results Cordycepin significantly inhibited the proliferation, colony formation, and migration of gastric cancer cells. After cordycepin treatment, the karyopycnosis, karyorrhexis, and apoptosis rate of cancer cells increased, and the expressions of apoptosis-related proteins c-caspase-3, c-caspase-9, and c-PARP increased. The expression of E-cadherin increased, while the expressions of vimentin, Snail, Slug, SREBF1, FASN, ACC1, MMP2, MMP9 significantly decreased; the phosphorylation levels of AMPK, JNK and P38 proteins significantly increased. Conclusion Cordycepin inhibits the proliferation and migration of gastric cancer cells by suppressing the lipid metabolism and EMT process via activating AMPK and MAPK signaling pathway.
Biol Pharm Bull. 2022 Jun 21.

Bisdemethoxycurcumin inhibits VEGF-induced HUVECs proliferation, migration and invasion through AMPK/mTOR pathway-dependent autophagy activation and cell cycle arrest.

Xianbin Wang, Tiantian Qu, Chuanfen Sun, Mingyu Wang.

  Vascular endothelial growth factor (VEGF) is a key mediator of angiogenesis, which plays a key role in the proliferation, migration and invasion of endothelial cell. Bisdemethoxycurcumin (BDMC) is a natural demethoxy curcumin derivative. In this study, we explored the mechanisms whereby BDMC is able to influence the proliferative, migratory and invasive activity of human umbilical vein endothelial cells (HUVECs) in response to VEGF treatment. These experiments revealed that BDMC at 10 and 20μM suppressed HUVECs proliferation in response to VEGF (10 ng/mL) without impacting the proliferation in absence of VEGF. BDMC treatment also signifantly suppressed VEGF-induced migratory and invasive activity in HUVECs. However, the selective AMPK inhibitor compound C (3 μM) treatment signifantly reversed all of these effects. Flow cytometric assay showed BDMC treatment was found to induce G0/G1 phase cell cycle arrest. Western blotting further indicated that BDMC treatment increased the ratios of p-AMPK/AMPK and LC3B/LC3A, up-regulated the expression of Beclin-1, decreased the ratio of p-mTOR/mTOR, down-regulated the expression of cyclin D1 and CDK4. Overall, these data suggested that BDMC may exert benefical effect on HUVECs activation by activating autophagy and inducing cell cycle arrest through regulation of the AMPK/mTOR pathway, which could provide a potential compound candidate for the treatment of diseases related to VEGF overproduction.

Keywords:  Autophagy; Bisdemethoxycurcumin; Cell cycle; Human umbilical vein endothelial cells

DOI:  https://doi.org/10.1248/bpb.b22-00194
Mol Biol Rep. 2022 Jun 22.

Metformin protects against ethanol-induced liver triglyceride accumulation by the LKB1/AMPK/ACC pathway.

Fotian Xie, Yuanming Zhong, Dongmei Wang, Kwok Fai So, Jia Xiao, Yi Lv.

  BACKGROUND: Hepatic lipid accumulation is one of the main pathological features of alcoholic liver disease (ALD). Metformin serves as an AMPK activator and has been shown to have lipids lowering effects in non-alcoholic fatty liver disease (NAFLD), but its role in ALD remains unclear. The purpose of this study was to explore the potential mechanism of metformin regulating lipid metabolism in ALD.METHODS AND RESULTS: In vitro and in vivo ALD models were established using AML12 cells and C57BL/6 mice, respectively. To determine the effect of metformin on ALD in vitro, the concentration of cellular triglyceride was examined by Nile red staining and a biochemical kit. To further reveal the role of metformin on ALD in vivo, liver tissues were examined by HE and oil red O staining, and the levels of ALT and AST in serum were determined via an automatic biochemical analyzer. The expression of mRNA and proteins were measured using qRT-PCR and Western blot, respectively. The role of the LKB1/AMPK/ACC axis on metformin regulating ethanol-induced lipid accumulation was evaluated by siRNA and AAV-shRNA interference. The results showed metformin reduced the ethanol-induced lipid accumulation in AML12 cells through activating AMPK, inhibiting ACC, reducing SREBP1c, and increasing PPARα. In addition, compared with control mice, metformin treatment inhibited ethanol-induced liver triglyceride accumulation and the increase of ALT and AST in serum. Interference with LKB1 attenuated the effect of metformin on ethanol-induced lipid accumulation both in vitro and in vivo.
CONCLUSION: Metformin protects against lipid formation in ALD by activating the LKB1/AMPK/ACC axis.

Keywords:  ACC; ALD; AMPK; LKB1; Metformin

DOI:  https://doi.org/10.1007/s11033-022-07610-y
Biology (Basel). 2022 May 30. pii: 839. [Epub ahead of print]11(6):

Joint Transcriptome and Metabolome Analysis Prevails the Biological Mechanisms Underlying the Pro-Survival Fight in In Vitro Heat-Stressed Granulosa Cells.

Abdul Sammad, Hanpeng Luo, Lirong Hu, Shanjiang Zhao, Jianfei Gong, Saqib Umer, Adnan Khan, Huabin Zhu, Yachun Wang.

  Previous studies reported the physical, transcriptome, and metabolome changes in in vitro acute heat-stressed (38 °C versus 43 °C for 2 h) bovine granulosa cells. Granulosa cells exhibited transient proliferation senescence, oxidative stress, an increased rate of apoptosis, and a decline in steroidogenic activity. In this study, we performed a joint integration and network analysis of metabolomic and transcriptomic data to further narrow down and elucidate the role of differentially expressed genes, important metabolites, and relevant cellular and metabolic pathways in acute heat-stressed granulosa cells. Among the significant (raw p-value < 0.05) metabolic pathways where metabolites and genes converged, this study found vitamin B6 metabolism, glycine, serine and threonine metabolism, phenylalanine metabolism, arginine biosynthesis, tryptophan metabolism, arginine and proline metabolism, histidine metabolism, and glyoxylate and dicarboxylate metabolism. Important significant convergent biological pathways included ABC transporters and protein digestion and absorption, while functional signaling pathways included cAMP, mTOR, and AMPK signaling pathways together with the ovarian steroidogenesis pathway. Among the cancer pathways, the most important pathway was the central carbon metabolism in cancer. Through multiple analysis queries, progesterone, serotonin, citric acid, pyridoxal, L-lysine, succinic acid, L-glutamine, L-leucine, L-threonine, L-tyrosine, vitamin B6, choline, and CYP1B1, MAOB, VEGFA, WNT11, AOX1, ADCY2, ICAM1, PYGM, SLC2A4, SLC16A3, HSD11B2, and NOS2 appeared to be important enriched metabolites and genes, respectively. These genes, metabolites, and metabolic, cellular, and cell signaling pathways comprehensively elucidate the mechanisms underlying the intricate fight between death and survival in acute heat-stressed bovine granulosa cells and essentially help further our understanding (and will help the future quest) of research in this direction.

Keywords:  AMPK pathway; cancer pathways; genes; granulosa cells; heat stress; integrated analysis; metabolites; protein metabolism

DOI:  https://doi.org/10.3390/biology11060839
Molecules. 2022 Jun 15. pii: 3837. [Epub ahead of print]27(12):

Potential Application of Gambogic Acid for Retarding Renal Cyst Progression in Polycystic Kidney Disease.

Nutchanard Khunpatee, Kanit Bhukhai, Varanuj Chatsudthipong, Chaowalit Yuajit.

  Abnormal cell proliferation and accumulation of fluid-filled cysts along the nephrons in polycystic kidney disease (PKD) could lead to a decline in renal function and eventual end-stage renal disease (ESRD). Gambogic acid (GA), a xanthone compound extracted from the brownish resin of the Garcinia hanburyi tree, exhibits various pharmacological properties, including anti-inflammation, antioxidant, anti-proliferation, and anti-cancer activity. However, its effect on inhibiting cell proliferation in PKD is still unknown. This study aimed to determine the pharmacological effects and detailed mechanisms of GA in slowing an in vitro cyst growth model of PKD. The results showed that GA (0.25-2.5 μM) significantly retarded MDCK cyst growth and cyst formation in a dose-dependent manner, without cytotoxicity. Using the BrdU cell proliferation assay, it was found that GA (0.5-2.5 μM) suppressed MDCK and Pkd1 mutant cell proliferation. In addition, GA (0.5-2.5 μM) strongly inhibited phosphorylation of ERK1/2 and S6K expression and upregulated the activation of phosphorylation of AMPK, both in MDCK cells and Pkd1 mutant cells. Taken together, these findings suggested that GA could retard MDCK cyst enlargement, at least in part by inhibiting the cell proliferation pathway. GA could be a natural plant-based drug candidate for ADPKD intervention.

Keywords:  AMPK; ERK1/2; MDCK cyst growth; S6K; gambogic acid

DOI:  https://doi.org/10.3390/molecules27123837
Exp Ther Med. 2022 Jul;24(1): 467

PTP1B inhibition ameliorates inflammatory injury and dysfunction in ox-LDL-induced HUVECs by activating the AMPK/SIRT1 signaling pathway via negative regulation of KLF2.

Yunfeng Zhang, Qiang Guan, Zhenfeng Wang.

  Atherosclerosis is a key pathogenic factor of cardiovascular diseases. However, the role of protein tyrosine phosphatase 1B (PTP1B) in oxidized low-density lipoprotein (ox-LDL)-treated vascular endothelial cells remains unclear. The aim of the present study was to explore the possible physiological roles and mechanism of PTP1B in atherosclerosis using HUVECs as an in vitro model. PTP1B expression was assessed by reverse transcription-quantitative PCR. Cell viability was measured using the Cell Counting Kit-8 and lactate dehydrogenase activity assays. Levels of inflammatory factors, including IL-1β, IL-6 and TNF-α, and oxidative stress factors, including malondialdehyde, superoxide dismutase and glutathione peroxidase, were assessed using ELISA and commercially available kits, respectively. Furthermore, TUNEL assay and western blotting were performed to assess the extent of apoptosis-related factors, including Bcl-2, Bax, Cleaved caspase-3 and Caspase-3. Tube formation assay was used to assess tubule formation ability and western blotting was to analyze VEGFA protein level. Binding sites for the transcription factor Kruppel-like factor 2 (KLF2) on the PTP1B promoter were predicted using the JASPAR database and verified using luciferase reporter assays and chromatin immunoprecipitation. The protein levels of phosphorylated 5'AMP-activated protein kinase (p-AMPK), AMPK and SIRT1 were measured using western blotting. The results demonstrated that the PTP1B mRNA and protein expression levels were significantly upregulated in oxidized low-density lipoprotein (ox-LDL)-induced HUVECs. In addition, ox-LDL-induced HUVECs transfected with short hairpin RNA against PTP1B exhibited a significant increase in cell viability, reduced inflammatory factor levels, apoptosis and oxidative stress, as well as increased tubule formation ability. KLF2 was found to negatively regulate the transcriptional activity of PTP1B. KLF2 knockdown reversed the protective effects of PTP1B knockdown on ox-LDL-induced HUVECs. KLF2 knockdown also abolished PTP1B knockdown-triggered AMPK/SIRT1 signaling pathway activation in ox-LDL-induced HUVECs. To conclude, the results of the present study suggested that PTP1B knockdown can prevent ox-LDL-induced inflammatory injury and dysfunction in HUVECs, which is regulated at least in part by the AMPK/SIRT1 signaling pathway through KLF2.

Keywords:  KLF2; PTP1B; atherosclerosis; inflammation; ox-LDL; transcription factor

DOI:  https://doi.org/10.3892/etm.2022.11394
Front Immunol. 2022 ;13 873382

Adiponectin Ameliorates GMH-Induced Brain Injury by Regulating Microglia M1/M2 Polarization Via AdipoR1/APPL1/AMPK/PPARγ Signaling Pathway in Neonatal Rats.

Ningbo Xu, Xifeng Li, Jun Weng, Chunhua Wei, Zhenyan He, Desislava Met Doycheva, Cameron Lenahan, Wenhui Tang, Jian Zhou, Yanchao Liu, Qiang Xu, Yahong Liu, Xuying He, Jiping Tang, John H Zhang, Chuanzhi Duan.

  Adiponectin (APN), a fat-derived plasma hormone, is a classic anti-inflammatory agent. Multiple studies have demonstrated the beneficial role of APN in acute brain injury, but the effect of APN in germinal matrix hemorrhage (GMH) is unclear, and the underlying molecular mechanisms remain largely undefined. In the current study, we used a GMH rat model with rh-APN treatment, and we observed that APN demonstrated a protective effect on neurological function and an inhibitory effect on neuroinflammation after GMH. To further explore the underlying mechanisms of these effects, we found that the expression of Adiponectin receptor 1 (AdipoR1) primarily colocalized with microglia and neurons in the brain. Moreover, AdiopR1, but not AdipoR2, was largely increased in GMH rats. Meanwhile, further investigation showed that APN treatment promoted AdipoR1/APPL1-mediated AMPK phosphorylation, further increased peroxisome proliferator-activated receptor gamma (PPARγ) expression, and induced microglial M2 polarization to reduce the neuroinflammation and enhance hematoma resolution in GMH rats. Importantly, either knockdown of AdipoR1, APPL1, or LKB1, or specific inhibition of AMPK/PPARγ signaling in microglia abrogated the protective effect of APN after GMH in rats. In all, we propose that APN works as a potential therapeutic agent to ameliorate the inflammatory response following GMH by enhancing the M2 polarization of microglia via AdipoR1/APPL1/AMPK/PPARγ signaling pathway, ultimately attenuating inflammatory brain injury induced by hemorrhage.

Keywords:  GMH; adiponectin; hematoma resolution; microglial polarization; neuroinflammation

DOI:  https://doi.org/10.3389/fimmu.2022.873382
Metabolites. 2022 Jun 06. pii: 523. [Epub ahead of print]12(6):

Abscisic Acid Improves Insulin Action on Glycemia in Insulin-Deficient Mouse Models of Type 1 Diabetes.

Mirko Magnone, Sonia Spinelli, Giulia Begani, Lucrezia Guida, Laura Sturla, Laura Emionite, Elena Zocchi.

  Abscisic acid (ABA), a plant hormone, has recently been shown to play a role in glycemia regulation in mammals, by stimulating insulin-independent glucose uptake and metabolism in skeletal muscle. The aim of this study was to test whether ABA could improve glycemic control in a murine model of type 1 diabetes (T1D). Mice were rendered diabetic with streptozotocin and the effect of ABA administration, alone or with insulin, was tested on glycemia. Diabetic mice treated with a single oral dose of ABA and low-dose subcutaneous insulin showed a significantly reduced glycemia profile compared with controls treated with insulin alone. In diabetic mice treated for four weeks with ABA, the effect of low-dose insulin on the glycemia profile after glucose load was significantly improved, and transcription both of the insulin receptor, and of glycolytic enzymes in muscle, was increased. Moreover, a significantly increased transcription and protein expression of AMPK, PGC1-α, and GLUT4 was observed in the skeletal muscle from diabetic mice treated with ABA, compared with untreated controls. ABA supplementation in conjunction with insulin holds the promise of reducing the dose of insulin required in T1D, reducing the risk of hypoglycemia, and improving muscle insulin sensitivity and glucose consumption.

Keywords:  ABA; AMPK; GLUT4; LANCL; T1D; skeletal muscle

DOI:  https://doi.org/10.3390/metabo12060523
Antioxidants (Basel). 2022 Jun 09. pii: 1137. [Epub ahead of print]11(6):

Activation of AMPK/miR-181b Axis Alleviates Endothelial Dysfunction and Vascular Inflammation in Diabetic Mice.

Chak-Kwong Cheng, Wenbin Shang, Jian Liu, Wai-San Cheang, Yu Wang, Li Xiang, Chi-Wai Lau, Jiang-Yun Luo, Chi-Fai Ng, Yu Huang, Li Wang.

  Hyperglycemia in diabetes mellitus impairs endothelial function and disrupts microRNA (miRNA) profiles in vasculature, increasing the risk of diabetes-associated complications, including coronary artery disease, diabetic retinopathy, and diabetic nephropathy. miR-181b was previously reported to be an anti-inflammatory mediator in vasculature against atherosclerosis. The current study aimed to investigate whether miR-181b ameliorates diabetes-associated endothelial dysfunction, and to identify potential molecular mechanisms and upstream inducer of miR-181b. We found that miR-181b level was decreased in renal arteries of diabetic patients and in advanced glycation end products (AGEs)-treated renal arteries of non-diabetic patients. Transfection of miR-181b mimics improved endothelium-dependent vasodilation in aortas of high fat diet (HFD)/streptozotocin (STZ)-induced diabetic mice, accompanied by suppression of superoxide overproduction and vascular inflammation markers. AMPK activator-induced AMPK activation upregulated miR-181b level in human umbilical vein endothelial cells (HUVECs). Chronic exercise, potentially through increased blood flow, activated AMPK/miR-181b axis in aortas of diabetic mice. Exposure to laminar shear stress upregulated miR-181b expression in HUVECs. Overall, our findings highlight a critical role of AMPK/miR-181b axis and extend the benefits of chronic exercise in counteracting diabetes-associated endothelial dysfunction.

Keywords:  ROS; diabetes mellitus; endothelial dysfunction; exercise; microRNA; shear stress; vascular inflammation

DOI:  https://doi.org/10.3390/antiox11061137
Curr Mol Pharmacol. 2022 Jun 20.

The therapeutic activities of metformin: Focus on the Nrf2 signaling pathway and oxidative stress amelioration.

Mohammad Yassin Zamanian, Lydia Giménez-Llort, Marjan Nikbakhtzadeh, Zahra Kamiab, Mahsa Heidari, Gholamreza Bazmandegan.

  In the present study, the health-protective and therapeutic properties of MET are revisited, giving focusing on the effect of MET on the Nrf2 expression in patients with different pathological conditions. Metformin (MET) regulates high blood glucose, thus being an integral part of the antidiabetic medications used to treat type 2 diabetes mellitus. It belongs to biguanide class medications that are administered through the oral route. Moreover, the agent is widely known for its anticancer, antioxidant, anti-inflammatory, and neuroprotective effects. The MET actually modulates the nuclear factor erythroid-2 related factor-2 (Nrf2) signaling pathway, which in turn yields the above-mentioned medical benefits to patients. The Nrf2 signaling pathways are modulated in multiple ways described subsequently: 1) MET acts on the cancer cells and inactivates Raf-ERK signaling, thus reducing Nrf2 expression, 2) MET obstructs the expression of proteins that are involved in apoptosis of tumor cells and also prevents tumor cells from oxidation through an AMPK-independent pathway; 3) MET carries out Keap1-independent mechanism for reducing the levels of Nrf2 protein in cancer cells; 4) MET upregulates the Nrf2-mediated transcription to stimulate the antioxidant process that prevents oxidative stress in cells system and consequently gives neuroprotection from rotenone and 5) MET downregulates p65 and upregulates Nrf2 which helps improve the angiogenesis impairment stimulated by gestational diabetes mellitus. This article presents an analysis of the health-protective properties of MET and also sheds light on the effect of MET on the Nrf2 expression in patients with different pathological conditions.

Keywords:  Cancer; Metformin; Neuroprotective; Nrf2; Oxidative stress; Tumor cell

DOI:  https://doi.org/10.2174/1874467215666220620143655
Oxid Med Cell Longev. 2022 ;2022 4240490

The Activated AMPK/mTORC2 Signaling Pathway Associated with Oxidative Stress in Seminal Plasma Contributes to Idiopathic Asthenozoospermia.

Nannan Cao, Chunhui Hu, Bintong Xia, Yan He, Jiaolong Huang, Zhicheng Yuan, Jie Deng, Peng Duan.

Asthenozoospermia is a common form of abnormal sperm quality in idiopathic male infertility. While most sperm-mediated causes have been investigated in detail, the significance of seminal plasma has been neglected. Herein, we aimed to investigate the possible pathogenic factors leading to decreased sperm motility based on seminal plasma. Semen was collected from normo- (NOR, n = 70), idiopathic oligo- (OLI, n = 57), and idiopathic asthenozoospermic (AST, n = 53) patients. Using attenuated total reflection-Fourier transform infrared coupled with chemometrics, distinct differences in the biochemical compositions of nucleic acids, protein structure (amides I, II, and III), lipids, and carbohydrates in seminal plasma of AST were observed when compared to NOR and OLI. Compared with NOR and OLI, the levels of peptide aggregation, protein phosphorylation, unsaturated fatty acid, and lipid to protein ratio were significantly increased in AST; however, the level of lipid saturation was significantly decreased in seminal plasma of AST. Compared with NOR, the levels of ROS, MDA, 8-iso-prostaglandin F2α (8-isoPGF2α), and the ratio of phospho-AMPKα/AMPKα1 were significantly increased in AST; however, the levels of SOD, glutathione S-transferase (GSTs), protein carbonyl derivative (PC), and the ratio of phospho-Rictor/Rictor were significantly decreased in seminal plasma of AST. Changes of the AMPK/mTORC2 signaling in the seminal microenvironment possibly induce abnormal glucose and lipid metabolism, which impairs energy production. Oxidative stress potentially damages seminal plasma lipids and proteins, which in turn leads to impaired sperm structure and function. These findings provide evidence that the changes in seminal plasma compositions, oxidative stress, and activation of the AMPK/mTORC2 signaling contribute to the development of asthenozoospermia.

DOI: https://doi.org/10.1155/2022/4240490
Front Physiol. 2022 ;13 910452

Compositions and Functions of Mitochondria-Associated Endoplasmic Reticulum Membranes and Their Contribution to Cardioprotection by Exercise Preconditioning.

Yuhu Lv, Lin Cheng, Fenglin Peng.

  Mitochondria-associated endoplasmic reticulum membranes (MAMs) are important components of intracellular signaling and contribute to the regulation of intracellular Ca2+/lipid homeostasis, mitochondrial dynamics, autophagy/mitophagy, apoptosis, and inflammation. Multiple studies have shown that proteins located on MAMs mediate cardioprotection. Exercise preconditioning (EP) has been shown to protect the myocardium from adverse stimuli, but these mechanisms are still being explored. Recently, a growing body of evidence points to MAMs, suggesting that exercise or EP may be involved in cardioprotection by modulating proteins on MAMs and subsequently affecting MAMs. In this review, we summarize the latest findings on MAMs, analyzing the structure and function of MAMs and the role of MAM-related proteins in cardioprotection. We focused on the possible mechanisms by which exercise or EP can modulate the involvement of MAMs in cardioprotection. We found that EP may affect MAMs by regulating changes in MFN2, MFN1, AMPK, FUNDC1, BECN1, VDAC1, GRP75, IP3R, CYPD, GSK3β, AKT, NLRP3, GRP78, and LC3, thus playing a cardioprotective role. We also provided direction for future studies that may be of interest so that more in-depth studies can be conducted to elucidate the relationship between EP and cardioprotection.

Keywords:  cardioprotection; exercise; exercise preconditioning; heart; mitochondria-associated endoplasmic reticulum membranes; preconditioning

DOI:  https://doi.org/10.3389/fphys.2022.910452