bims-bicyki 2021-06-13 papers

bims-bicyki

Biomed News

on Bicaudal-C1 and interactors in cystic kidney disease

Issue of 2021–06–13
23 papers selected by
Céline Gagnieux, École Polytechnique Fédérale de Lausanne

PKD2 gene variants in Chinese patients with autosomal dominant polycystic kidney disease.
Overweight and Obesity and Progression of ADPKD.
Intraflagellar Transport Proteins as Regulators of Primary Cilia Length.
Mechanoregulation of YAP and TAZ in Cellular Homeostasis and Disease Progression.
[Diagnosis of a case of autosomal recessive polycystic kidney disease with combined prenatal imaging and genetic testing].
The Joubert syndrome protein CEP41 is excluded from the distal segment of cilia in C. elegans.
Geranylgeraniol prevents zoledronic acid-mediated reduction of viable mesenchymal stem cells via induction of Rho-dependent YAP activation.
Structural Design and Analysis of the RHOA-ARHGEF1 Binding Mode: Challenges and Applications for Protein-Protein Interface Prediction.
Lysophosphatidic Acid Regulates Rho Family of GTPases in Lungs.
Primary ciliary dyskinesia due to CCNO mutations-A genotype-phenotype correlation contribution.
Bioprinting of kidney in vitro models: cells, biomaterials, and manufacturing techniques.
The Integral Role of RNA in Stress Granule Formation and Function.
The renal patient seen by non-renal physicians: the kidney embedded in the 'milieu intérieur'.
Rapamycin accelerates axon regeneration through Schwann cell-mediated autophagy following inferior alveolar nerve transection in rats.
Centrosomes: An acentriolar MTOC at the ciliary base.
Augmented Respiratory-Sympathetic Coupling and Hemodynamic Response to Acute Mild Hypoxia in Female Rodents With Chronic Kidney Disease.
A temporal Ca2+-desensitization of myosin light chain kinase in phasic smooth muscles induced by CaMKKß/PP2A pathways.
MicroRNA-145-5p inhibits hypoxia/reoxygenation-induced apoptosis in H9c2 cardiomyocytes by targeting ROCK1.
Cystic fibrosis.
Hypoxia-induced thyroid hormone receptor expression regulates cell-cycle progression in renal tubule epithelial cells.
YAP/TAZ suppress drug penetration into hepatocellular carcinoma via stromal activation.
Chronic restraint stress induces changes in the cerebral Galpha 12/13 and Rho-GTPase signaling network.
Acute kidney disease in hospitalized acute kidney injury patients.

Clin Genet. 2021 Jun 07.

PKD2 gene variants in Chinese patients with autosomal dominant polycystic kidney disease.

Dechao Xu, Rongrong Bian, Suxin Tuo, Xuezhen Li, Jing Chen, Xiaohong Xing, Yunhui Lu, Lijun Sun, Xiaojing Tang, Shengqiang Yu, Zhiguo Mao, Yiyi Ma, Changlin Mei.

  PKD2 gene variants account for 4.5% to 20% of patients with autosomal dominant polycystic kidney disease (ADPKD). Little is known about the clinical characteristics of PKD2 variants in Chinese patients with ADPKD. Herein, we performed a comprehensive search for variants of PKD2 gene in 44 Chinese ADPKD pedigrees and a total of 37 variants were identified. Of these 37 variants, 18 were nonsense variants, 10 frameshift variants, 4 missense variants, and 5 splice site variants. 11/37 variants were detected for the first time. The median age at diagnosis was 30.5 years, and positive family history was detected in 77.27% patients, liver cysts in 68.18%, hypertension in 45.45%, nephrolithiasis in 31.82%, macro-hematuria in 22.73% and proteinuria in 13.63%. The level of estimated glomerular filtration rate in 8/39 patients were blow 60 mL/min/1.73m2 . 11/17 patients were classified as rapid progression by Mayo Clinic classification. The end stage renal disease (ESRD) events were reported in 9/22 pedigrees, and the presence of nephrolithiasis and macro-hematuria were significantly associated with ESRD in the pedigrees with PKD2 variants. The identified variants and clinical features will facilitate the early diagnosis and prognosis prediction in Chinese ADPKD patients with PKD2 variants.

Keywords:  Autosomal dominant polycystic kidney disease; Chinese patients; Clinical features; PKD2 gene variants

DOI:  https://doi.org/10.1111/cge.14008
Clin J Am Soc Nephrol. 2021 Jun;16(6): 908-915

Overweight and Obesity and Progression of ADPKD.

Kristen L Nowak, Cortney Steele, Berenice Gitomer, Wenchyi Wang, John Ouyang, Michel B Chonchol.

   BACKGROUND AND OBJECTIVES: On the basis of earlier observations, we evaluated the association between overweight and obesity and rapid progression of autosomal dominant polycystic kidney disease in participants in the Tolvaptan Efficacy and Safety in Management of Autosomal Dominant Polycystic Kidney Disease and Its Outcomes (TEMPO) 3:4 trial. More importantly, we also determined whether efficacy of tolvaptan was attenuated in individuals with baseline overweight or obesity.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A total of 1312 study participants with relatively early-stage autosomal dominant polycystic kidney disease (mean eGFR 78±22 ml/min per 1.73 m2) who were at high risk of rapid progression were categorized by body mass index (BMI; calculated using nonkidney weight) as normal weight (18.5-24.9 kg/m2; n=670), overweight (25.0-29.9 kg/m2; n=429), or obese (≥30 kg/m2; n=213). Linear and multinomial logistic regression models were used to determine the association of baseline overweight and obesity with change in total kidney volume (TKV) over the 3-year study period.
RESULTS: In fully adjusted models, higher BMI was associated with greater annual percent change in TKV (difference of 1.20 [95% confidence interval (95% CI), 0.85 to 1.55] per five-unit higher BMI). Overweight and obesity were associated with higher odds of annual percent change in TKV of ≥7% versus <5% (overweight: odds ratio, 2.04 [95% CI, 1.45 to 2.87]; obese: odds ratio, 4.31 [95% CI, 2.83 to 6.57] versus normal weight). eGFR decline did not differ according to BMI (fully adjusted difference in decline of -0.95 [95% CI, -2.32 to 0.40] ml/min per 1.73 m2 per year per five-unit higher BMI). The three-way interaction (treatment×time×BMI group) was not statistically significant in linear mixed models with an outcome of TKV (log-transformed estimated coefficient comparing the treatment effect for overweight versus normal weight: 0.56% [95% CI, -0.70% to 1.84%] per year; P=0.38; obese versus normal weight: 0.07% [95% CI, -1.47% to 1.63%] per year; P=0.93) or eGFR (estimated coefficient comparing overweight versus normal weight: -0.07 [95% CI, -0.95 to 0.82] ml/min per 1.73 m2 per year; P=0.88; obese versus normal weight: 0.22 [95% CI, -0.93 to 1.36] ml/min per 1.73 m2 per year; P=0.71).
CONCLUSIONS: Overweight and particularly obesity are strongly and independently associated with kidney growth, but not eGFR slope, in the TEMPO 3:4 trial, and tolvaptan efficacy is irrespective of BMI categorization.
CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Tolvaptan Efficacy and Safety in Management of Autosomal Dominant Polycystic Kidney Disease and Its Outcomes (TEMPO) 3:4, NCT00428948.

Keywords:  ADPKD; disease progression; epidemiology and outcomes; obesity; overweight; polycystic kidney disease

DOI:  https://doi.org/10.2215/CJN.16871020
Front Cell Dev Biol. 2021 ;9 661350

Intraflagellar Transport Proteins as Regulators of Primary Cilia Length.

Wei Wang, Brittany M Jack, Henry H Wang, Matthew A Kavanaugh, Robin L Maser, Pamela V Tran.

  Primary cilia are small, antenna-like organelles that detect and transduce chemical and mechanical cues in the extracellular environment, regulating cell behavior and, in turn, tissue development and homeostasis. Primary cilia are assembled via intraflagellar transport (IFT), which traffics protein cargo bidirectionally along a microtubular axoneme. Ranging from 1 to 10 μm long, these organelles typically reach a characteristic length dependent on cell type, likely for optimum fulfillment of their specific roles. The importance of an optimal cilia length is underscored by the findings that perturbation of cilia length can be observed in a number of cilia-related diseases. Thus, elucidating mechanisms of cilia length regulation is important for understanding the pathobiology of ciliary diseases. Since cilia assembly/disassembly regulate cilia length, we review the roles of IFT in processes that affect cilia assembly/disassembly, including ciliary transport of structural and membrane proteins, ectocytosis, and tubulin posttranslational modification. Additionally, since the environment of a cell influences cilia length, we also review the various stimuli encountered by renal epithelia in healthy and diseased states that alter cilia length and IFT.

Keywords:  IFT-A; IFT-B; cilia disassembly; ciliogenesis; ectocytosis; kidney; posttranslational modification

DOI:  https://doi.org/10.3389/fcell.2021.661350
Front Cell Dev Biol. 2021 ;9 673599

Mechanoregulation of YAP and TAZ in Cellular Homeostasis and Disease Progression.

Xiaomin Cai, Kuei-Chun Wang, Zhipeng Meng.

  Biophysical cues, such as mechanical properties, play a critical role in tissue growth and homeostasis. During organ development and tissue injury repair, compressive and tensional forces generated by cell-extracellular matrix or cell-cell interaction are key factors for cell fate determination. In the vascular system, hemodynamic forces, shear stress, and cyclic stretch modulate vascular cell phenotypes and susceptibility to atherosclerosis. Despite that emerging efforts have been made to investigate how mechanotransduction is involved in tuning cell and tissue functions in various contexts, the regulatory mechanisms remain largely unknown. One of the challenges is to understand the signaling cascades that transmit mechanical cues from the plasma membrane to the cytoplasm and then to the nuclei to generate mechanoresponsive transcriptomes. YAP and its homolog TAZ, the Hippo pathway effectors, have been identified as key mechanotransducers that sense mechanical stimuli and relay the signals to control transcriptional programs for cell proliferation, differentiation, and transformation. However, the upstream mechanosensors for YAP/TAZ signaling and downstream transcriptome responses following YAP/TAZ activation or repression have not been well characterized. Moreover, the mechanoregulation of YAP/TAZ in literature is highly context-dependent. In this review, we summarize the biomechanical cues in the tissue microenvironment and provide an update on the roles of YAP/TAZ in mechanotransduction in various physiological and pathological conditions.

Keywords:  ECM stiffness; TAZ; YAP; contact inhibition of cells; flow shear; mechanotransduction; stretch; the Hippo pathway

DOI:  https://doi.org/10.3389/fcell.2021.673599
Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2021 Jun 10. 38(6): 585-588

[Diagnosis of a case of autosomal recessive polycystic kidney disease with combined prenatal imaging and genetic testing].

Yinghui Lu, Huili Liu, Haojie Wu, Liu Liu, Tianyou Wang.

OBJECTIVE: To explore the genetic basis for a fetus with renal abnormalities through whole exome sequencing and imaging examination.
METHODS: Clinical data and result of medical imaging of the fetus was collected. Amniotic fluid sample was collected for the extraction of fetal DNA. Whole exome sequencing was carried out. Candidate variants were verified by Sanger sequencing.
RESULTS: Prenatal ultrasonography showed that the fetus had bilateral enlargement of the kidneys with hyperechogenicity and diffuse renal cysts. Whole exome sequencing revealed that the fetus carried compound heterozygous variants of the PKHD1 gene, namely c.5137G>T and c.2335_2336delCA, which were derived from its mother and father, respectively.
CONCLUSION: The fetus was diagnosed with autosomal recessive polycystic kidney disease through combined prenatal ultrasonography and whole exome sequencing. The compound heterozygous variants of the PKHD1 gene probably underlay the pathogenesis in the fetus. The results have enabled prenatal diagnosis and genetic counseling for its parents.

DOI: https://doi.org/10.3760/cma.j.cn511374-20210108-00018
MicroPubl Biol. 2021 Jun 07. 2021

The Joubert syndrome protein CEP41 is excluded from the distal segment of cilia in C. elegans.

Sebiha Cevik, Oktay I Kaplan.

Rare diseases are a fundamental issue in today's world, affecting more than 300 million individuals worldwide. According to data from Orphanet and OMIM, about 50-60 new conditions are added to the list of over 6,000 clinically distinct diseases each year, rendering disease diagnosis and treatment even more challenging. Ciliopathies comprise a heterogeneous category of rare diseases made up of over 35 distinct diseases, including Joubert syndrome (JBTS; OMIM 213300), that are caused by functional and structural defects in cilia. JBTS is an autosomal recessive condition characterized by a range of symptoms, including cerebellar vermis hypoplasia and poor muscle tone. There are now a total of 38 genes that cause JBTS, almost all of which encode protein products that are found in cilia and cilia-associated compartments, such as the basal body and transition zone. CEP41 is a JBTS-associated protein that is found in cilia and the basal body of mammals, but its localization in other ciliary organisms remains elusive. C. elegans is an excellent model organism for studying the molecular mechanisms of rare diseases like JBTS. We, therefore, decided to use C. elegans to identify the localization of CEP41. Our microscopy analysis revealed that CEPH-41(CEntrosomal Protein Homolog 41) not only localizes to cilia but is excluded from the distal segment of the amphid and phasmid cilia in C. elegans. Furthermore, we discovered a putative X-box motif located in the promoter of ceph-41 and the expression of ceph-41 is regulated by DAF-19, a sole Regulatory Factor X (RFX) transcription factor.

DOI: https://doi.org/10.17912/micropub.biology.000406
R Soc Open Sci. 2021 Jun 09. 8(6): 202066

Geranylgeraniol prevents zoledronic acid-mediated reduction of viable mesenchymal stem cells via induction of Rho-dependent YAP activation.

Weerachai Singhatanadgit, Weerawan Hankamolsiri, Wanida Janvikul.

  Long-term use of zoledronic acid (ZA) increases the risk of medication-related osteonecrosis of the jaw (MRONJ). This may be attributed to ZA-mediated reduction of viable mesenchymal stem cells (MSCs). ZA inhibits protein geranylgeranylation, thus suppressing cell viability and proliferation. Geranylgeraniol (GGOH), which is a naturally found intermediate compound in the mevalonate pathway, has positive effects against ZA. However, precise mechanisms by which GGOH may help preserve stem cell viability against ZA are not fully understood. The objective of this study was to investigate the cytoprotective mechanisms of GGOH against ZA. The results showed that while ZA dramatically decreased the number of viable MSCs, GGOH prevented this negative effect. GGOH-rescued ZA-exposed MSCs formed mineralization comparable to that produced by normal MSCs. Mechanistically, GGOH preserved the number of viable MSCs by its reversal of ZA-mediated Ki67+ MSC number reduction, cell cycle arrest and apoptosis. Moreover, GGOH prevented ZA-suppressed RhoA activity and YAP activation. The results also established the involvement of Rho-dependent YAP and YAP-mediated CDK6 in the cytoprotective ability of GGOH against ZA. In conclusion, GGOH preserves a pool of viable MSCs with osteogenic potency against ZA by rescuing the activity of Rho-dependent YAP activation, suggesting GGOH as a promising agent and YAP as a potential therapeutic target for MRONJ.

Keywords:  RhoA; YAP; cytotoxicity; geranylgeraniol; mesenchymal stem cell; zoledronic acid

DOI:  https://doi.org/10.1098/rsos.202066
Front Mol Biosci. 2021 ;8 643728

Structural Design and Analysis of the RHOA-ARHGEF1 Binding Mode: Challenges and Applications for Protein-Protein Interface Prediction.

Ennys Gheyouche, Matthias Bagueneau, Gervaise Loirand, Bernard Offmann, Stéphane Téletchéa.

  The interaction between two proteins may involve local movements, such as small side-chains re-positioning or more global allosteric movements, such as domain rearrangement. We studied how one can build a precise and detailed protein-protein interface using existing protein-protein docking methods, and how it can be possible to enhance the initial structures using molecular dynamics simulations and data-driven human inspection. We present how this strategy was applied to the modeling of RHOA-ARHGEF1 interaction using similar complexes of RHOA bound to other members of the Rho guanine nucleotide exchange factor family for comparative assessment. In parallel, a more crude approach based on structural superimposition and molecular replacement was also assessed. Both models were then successfully refined using molecular dynamics simulations leading to protein structures where the major data from scientific literature could be recovered. We expect that the detailed strategy used in this work will prove useful for other protein-protein interface design. The RHOA-ARHGEF1 interface modeled here will be extremely useful for the design of inhibitors targeting this protein-protein interaction (PPI).

Keywords:  ARHGEF1; PPI; RHOA; molecular dynamics simulation; protein-protein docking

DOI:  https://doi.org/10.3389/fmolb.2021.643728
Cell Biochem Biophys. 2021 Jun 10.

Lysophosphatidic Acid Regulates Rho Family of GTPases in Lungs.

Kevin C Tran, Jing Zhao.

  The bio-active lipid, lysophosphatidic acid (LPA) interacts with various lysophosphatidic acid receptors (LPARs) to affect a variety of cellular functions, including proliferation, differentiation, survival, migration, morphogenesis and others. The Rho family of small GTPases, is well-known downstream signaling pathways activated by LPA. Among the Rho GTPases, RhoA, Rac1, and Cdc42 are best characterized and LPA-induced activation of the GTPases RhoA, Rac1, and Cdc42 influences a wide range of cellular processes and functions such as cell differentiation, contractile movements, cellular migration, or infiltration. In this review, we will briefly discuss the interplay between LPA and each of these three Rho family proteins, summarizing the main interactions between them. Our discussion will focus mainly on their interplay within lung endothelial and epithelial cells, drawing attention to how these interactions may contribute to pro-inflammatory processes.

Keywords:  Cdc42; LPA; Lung endothelial and epithelial; Rac1; RhoA

DOI:  https://doi.org/10.1007/s12013-021-00993-y
Pediatr Pulmonol. 2021 Jun 08.

Primary ciliary dyskinesia due to CCNO mutations-A genotype-phenotype correlation contribution.

Ana Raquel Henriques, Carolina Constant, Andreia Descalço, Andreia Pinto, J Moura Nunes, Pedro Sampaio, Susana S Lopes, Luísa Pereira, Teresa Bandeira.

  Primary ciliary dyskinesia (PCD) is genetically and clinically heterogeneous. CCNO mutations are associated with chronic destructive lung disease and were first described in 2014. Early reports suggest that CCNO is mutated more frequently than expected, however, these are considered rare. We report on three eleven-year-old children with PCD due to CCNO mutations. All children presented early-onset respiratory symptoms, no cardiac or situs anomalies and moderate to severe clinical courses. Patients 1 and 3 were admitted to a neonatal intensive care unit due to respiratory distress. Patients 1 and 2 had atelectasis and lobar collapse, for which lobectomy was performed for patient 1. Patient 3 also presented otitis media with effusion with conductive hearing loss, requiring tympanostomy tube insertion twice. Diagnosis of PCD for all three required repeated nasal brushings, delaying diagnostic confirmation. Microscopy analysis revealed severely decreased numbers of cilia, but normal ultrastructure and uncoordinated beat pattern in the residual cilia. Surprisingly, the prevalence of pathogenic CCNO variants in our centre is higher than expected (three out of sixteen patients). Pathogenic variants in PCD-causing genes lead to specific ultrastructural defects, and there is a suggestion for genotype-phenotype association. However, there are little longitudinal data evaluating the impact of specific defects on disease progression, but a recent study showed a worse lung disease and poorer nutritional status. Concluding, this report underlies the importance of patient-oriented diagnosis and management in highly experienced PCD centres.

Keywords:  CCNO mutations; child; chronic diseases; ciliary motility disorders

DOI:  https://doi.org/10.1002/ppul.25440
Essays Biochem. 2021 Jun 07. pii: EBC20200158. [Epub ahead of print]

Bioprinting of kidney in vitro models: cells, biomaterials, and manufacturing techniques.

Maaike F J Fransen, Gabriele Addario, Carlijn V C Bouten, Franck Halary, Lorenzo Moroni, Carlos Mota.

  The number of patients with end-stage renal disease is continuously increasing worldwide. The only therapies for these patients are dialysis and organ transplantation, but the latter is limited due to the insufficient number of donor kidneys available. Research in kidney disease and alternative therapies are therefore of outmost importance. In vitro models that mimic human kidney functions are essential to provide better insights in disease and ultimately novel therapies. Bioprinting techniques have been increasingly used to create models with some degree of function, but their true potential is yet to be achieved. Bioprinted renal tissues and kidney-like constructs presents challenges, for example, choosing suitable renal cells and biomaterials for the formulation of bioinks. In addition, the fabrication of complex renal biological structures is still a major bottleneck. Advances in pluripotent stem cell-derived renal progenitors has contributed to in vivo-like rudiment structures with multiple renal cells, and these started to make a great impact on the achieved models. Natural- or synthetic-based biomaterial inks, such as kidney-derived extracellular matrix and gelatin-fibrin hydrogels, which show the potential to partially replicate in vivo-like microenvironments, have been largely investigated for bioprinting. As the field progresses, technological, biological and biomaterial developments will be required to yield fully functional in vitro tissues that can contribute to a better understanding of renal disease, to improve predictability in vitro of novel therapeutics, and to facilitate the development of alternative regenerative or replacement treatments. In this review, we resume the main advances on kidney in vitro models reported so far.

Keywords:  Bioprinting; biomaterials; in vitro models; kidney

DOI:  https://doi.org/10.1042/EBC20200158
Front Cell Dev Biol. 2021 ;9 621779

The Integral Role of RNA in Stress Granule Formation and Function.

Danae Campos-Melo, Zachary C E Hawley, Cristian A Droppelmann, Michael J Strong.

  Stress granules (SGs) are phase-separated, membraneless, cytoplasmic ribonucleoprotein (RNP) assemblies whose primary function is to promote cell survival by condensing translationally stalled mRNAs, ribosomal components, translation initiation factors, and RNA-binding proteins (RBPs). While the protein composition and the function of proteins in the compartmentalization and the dynamics of assembly and disassembly of SGs has been a matter of study for several years, the role of RNA in these structures had remained largely unknown. RNA species are, however, not passive members of RNA granules in that RNA by itself can form homo and heterotypic interactions with other RNA molecules leading to phase separation and nucleation of RNA granules. RNA can also function as molecular scaffolds recruiting multivalent RBPs and their interactors to form higher-order structures. With the development of SG purification techniques coupled to RNA-seq, the transcriptomic landscape of SGs is becoming increasingly understood, revealing the enormous potential of RNA to guide the assembly and disassembly of these transient organelles. SGs are not only formed under acute stress conditions but also in response to different diseases such as viral infections, cancer, and neurodegeneration. Importantly, these granules are increasingly being recognized as potential precursors of pathological aggregates in neurodegenerative diseases. In this review, we examine the current evidence in support of RNA playing a significant role in the formation of SGs and explore the concept of SGs as therapeutic targets.

Keywords:  RNA; RNP; cancer; neurodegeneration; stress granules; virus

DOI:  https://doi.org/10.3389/fcell.2021.621779
Clin Kidney J. 2021 Apr;14(4): 1077-1087

The renal patient seen by non-renal physicians: the kidney embedded in the 'milieu intérieur'.

Felix Perez-Villa, Marie Hélène Lafage-Proust, Eveline Gielen, Alberto Ortiz, Goce Spasovski, Àngel Argilés.

  Chronic kidney disease is defined as a decrease in renal function or evidence of kidney injury for >3 months. This represents an oversimplification that may confuse physicians. Thus kidney function is equated to glomerular filtration rate, which represents one of multiple kidney functions. Some potentially more important renal functions are lost earlier, such as the production for the anti-ageing factor Klotho. Overall, these changes modify the emergent properties of the body, altering the relationships between different organs and systems, in a manner that is difficult to predict the response to interventions based on normal physiology concepts, as there is a novel steady state of interorgan relations. In this regard we now discuss the impact of CKD on heart failure; osteomuscular and joint pain and bone fragility and fractures; and osteosarcopaenia as seen by a cardiologist, a rheumatologist and a geriatrician.

Keywords:  bone fragility; chronic kidney disease; emergence; fracture; heart failure; network disease; osteosarcopaenia

DOI:  https://doi.org/10.1093/ckj/sfaa234
Neuroscience. 2021 Jun 05. pii: S0306-4522(21)00280-3. [Epub ahead of print]

Rapamycin accelerates axon regeneration through Schwann cell-mediated autophagy following inferior alveolar nerve transection in rats.

Takanobu Inada, Hitoshi Sato, Yoshinori Hayashi, Suzuro Hitomi, Akihiko Furukawa, Masatoshi Ando, Eri Oshima, Jo Otsuji, Naoto Taguchi, Ikuko Shibuta, Hiromasa Tsuda, Koichi Iwata, Tatsuo Shirota, Masamichi Shinoda.

  Sensory disturbance in the orofacial region owing to trigeminal nerve injury is caused by dental treatment or accident. Commercially available therapeutics are ineffective for the treatment of sensory disturbance. Additionally, the therapeutic effects of rapamycin, an allosteric inhibitor of mammalian target of rapamycin (mTOR), which negatively regulates autophagy, on the sensory disturbance are not fully investigated. Thus, we investigated the therapeutic effects of rapamycin on the sensory disturbance in the mandibular region caused by inferior alveolar nerve (IAN) transection (IANX) in rats. The expression levels of the phosphorylated p70S6K, a downstream molecule of mTOR, in the proximal and distal stumps of the transected IAN were significantly reduced by rapamycin administration to the injured site. Conversely, the increments of both Beclin 1 and microtubule-associated protein-1 light chain 3-II protein levels in the proximal and distal stumps of the transected IAN was induced by rapamycin administration. Immunohistochemical analyses revealed that Beclin 1 was located in Schwann cells in the proximal stump of the IAN. Accumulation of myelin protein zero and myelin basic protein in the proximal and distal stumps of the IAN was significantly reduced by rapamycin administration. Rapamycin administration facilitated axon regeneration after IANX and increased the number of brain-derived neurotrophic factor positive neurons in the trigeminal ganglion. Thus, recovery from sensory disturbance in the lower lip caused by IANX was markedly facilitated by rapamycin. These findings suggest that rapamycin administration is a promising treatment for the sensory disturbance caused by IANX.

Keywords:  Rapamycin; Schwann cell; autophagy; axon regeneration; peripheral nerve transection

DOI:  https://doi.org/10.1016/j.neuroscience.2021.05.033
Curr Biol. 2021 Jun 07. pii: S0960-9822(21)00474-7. [Epub ahead of print]31(11): R730-R733

Centrosomes: An acentriolar MTOC at the ciliary base.

Kevin F O'Connell.

Centrioles are microtubule-based organelles that are embedded within pericentriolar material (PCM). Together, they comprise the centrosome, a microtubule-organizing center. PCM can sometimes exist in the absence of centrioles, but a new example of acentriolar PCM in neurons offers deeper insight into the relationship between these two entities.

DOI: https://doi.org/10.1016/j.cub.2021.03.101
Front Physiol. 2021 ;12 623599

Augmented Respiratory-Sympathetic Coupling and Hemodynamic Response to Acute Mild Hypoxia in Female Rodents With Chronic Kidney Disease.

Manash Saha, Qi-Jian Sun, Cara M Hildreth, Peter G R Burke, Jacqueline K Phillips.

  Carotid body feedback and hypoxia may serve to enhance respiratory-sympathetic nerve coupling (respSNA) and act as a driver of increased blood pressure. Using the Lewis polycystic kidney (LPK) rat model of chronic kidney disease, we examined respSNA in adult female rodents with CKD and their response to acute hypoxia or hypercapnia compared to Lewis control animals. Under urethane anesthesia, phrenic nerve activity, splanchnic sympathetic nerve activity (sSNA), and renal sympathetic nerve activity (rSNA) were recorded under baseline conditions and during mild hypoxic or hypercapnic challenges. At baseline, tonic SNA and blood pressure were greater in female LPK rats versus Lewis rats (all P < 0.05) and respSNA was at least two-fold larger [area under the curve (AUC), sSNA: 7.8 ± 1.1 vs. 3.4 ± 0.7 μV s, rSNA: 11.5 ± 3 vs. 4.8 ± 0.7 μV s, LPK vs. Lewis, both P < 0.05]. Mild hypoxia produced a larger pressure response in LPK [Δ mean arterial pressure (MAP) 30 ± 6 vs. 12 ± 6 mmHg] and augmented respSNA (ΔAUC, sSNA: 8.9 ± 3.4 vs. 2 ± 0.7 μV s, rSNA: 6.1 ± 1.2 vs. 3.1 ± 0.7 μV s, LPK vs. Lewis, all P ≤ 0.05). In contrast, central chemoreceptor stimulation produced comparable changes in blood pressure and respSNA (ΔMAP 13 ± 3 vs. 9 ± 5 mmHg; respSNA ΔAUC, sSNA: 2.5 ± 1 vs. 1.3 ± 0.7 μV s, rSNA: 4.2 ± 0.9 vs. 3.5 ± 1.4 μV s, LPK vs. Lewis, all P > 0.05). These results demonstrate that female rats with CKD exhibit heightened respSNA coupling at baseline that is further augmented by mild hypoxia, and not by hypercapnia. This mechanism may be a contributing driver of hypertension in this animal model of CKD.

Keywords:  chemoreflex; chronic kidney disease; female; hypercapnia; hypertension; hypoxia; respiratory sympathetic modulation

DOI:  https://doi.org/10.3389/fphys.2021.623599
Am J Physiol Cell Physiol. 2021 06 09.

A temporal Ca2+-desensitization of myosin light chain kinase in phasic smooth muscles induced by CaMKKß/PP2A pathways.

Toshio Kitazawa, Toshiyasu Matsui, Shuichi Katsuki, Akira Goto, Kai Akagi, Naoya Hatano, Hiroshi Tokumitsu, Kosuke Takeya, Masumi Eto.

  Cell signaling pathways regulating myosin regulatory light chain (LC20) phosphorylation contribute to determining contractile responses in smooth muscles. Following excitation and contraction, phasic smooth muscles, such as digestive tract and urinary bladder, undergo a relaxation due to a decline of cellular [Ca2+] and a decreased Ca2+ sensitivity of LC20 phosphorylation, named Ca2+ desensitization. Here, we determined mechanisms underlying the temporal Ca2+ desensitization of LC20 phosphorylation in phasic smooth muscles using permeabilized strips of mouse ileum and urinary bladder. Upon the stimulation with pCa6.0 at 20°C, the contraction and the LC20 phosphorylation peaked within 30 sec and then declined to about 50% of the peak force at 2 min after stimulation. During the relaxation phase after the contraction, the LC20 kinase (MLCK) was inactivated, but no fluctuation in the LC20 phosphatase activity occurred, suggesting that the MLCK inactivation is a cause of the Ca2+-induced Ca2+-desensitization of LC20 phosphorylation. The MLCK inactivation was associated with phosphorylation at the calmodulin binding domain of the kinase. Treatment with antagonists for CaMKKß (STO-609 and TIM-063) attenuated both the phasic response of the contraction and MLCK phosphorylation, whereas neither CaMKII, AMPK nor PAK induced the MLCK inactivation in phasic smooth muscles. Conversely, PP2A inhibition amplified the phasic response. Signaling pathways through CaMKKß and PP2A may contribute to regulating the Ca2+ sensitivity of MLCK and the contractile response of phasic smooth muscles.

Keywords:  digestive tract; kinase cascade; myography; signal transduction; smooth muscle

DOI:  https://doi.org/10.1152/ajpcell.00136.2021
Exp Ther Med. 2021 Aug;22(2): 796

MicroRNA-145-5p inhibits hypoxia/reoxygenation-induced apoptosis in H9c2 cardiomyocytes by targeting ROCK1.

Chao Cheng, Dong-Ling Xu, Xiao-Bo Liu, Shao-Jie Bi, Juan Zhang.

  There is increasing evidence that microRNAs (miRs) play critical roles in the pathological and physiological processes associated with myocardial ischemia reperfusion (I/R). miR-145 has been extensively studied in the cardiovascular system; however, the role of miR-145 in myocardial I/R remains unclear. Therefore, the present study aimed to investigate the role and mechanism of miR-145-5p in myocardial I/R by establishing a hypoxia/reoxygenation (H/R) model using H9c2 cardiomyocytes. The expression of miR-145-5p was regulated by transfection and the potential target of miR-145-5p was identified. In addition, apoptosis of the cardiomyocytes was evaluated using flow cytometry and the detection of cleaved caspase-3 by western blotting. The results revealed that miR-145-5p expression was decreased while cell apoptosis and Rho-associated coiled-coil-containing kinase 1 (ROCK1) expression were increased in H/R-stimulated H9c2 cardiomyocytes. The upregulation of miR-145-5p reduced apoptosis and the expression of ROCK1 in H/R-stimulated H9c2 cardiomyocytes. Furthermore, the overexpression of ROCK1 significantly attenuated the miR-145-5p-induced reduction of apoptosis following H/R. In conclusion, the present study indicates that the overexpression of miR-145-5p inhibits H/R-induced cardiomyocyte apoptosis by targeting ROCK1.

Keywords:  H9c2; ROCK1; cardiomyocyte apoptosis; hypoxia/reoxygenation; microRNA-145-5p

DOI:  https://doi.org/10.3892/etm.2021.10228
Lancet. 2021 Jun 05. pii: S0140-6736(20)32542-3. [Epub ahead of print]397(10290): 2195-2211

Cystic fibrosis.

Michal Shteinberg, Iram J Haq, Deepika Polineni, Jane C Davies.

Cystic fibrosis is a monogenic disease considered to affect at least 100 000 people worldwide. Mutations in CFTR, the gene encoding the epithelial ion channel that normally transports chloride and bicarbonate, lead to impaired mucus hydration and clearance. Classical cystic fibrosis is thus characterised by chronic pulmonary infection and inflammation, pancreatic exocrine insufficiency, male infertility, and might include several comorbidities such as cystic fibrosis-related diabetes or cystic fibrosis liver disease. This autosomal recessive disease is diagnosed in many regions following newborn screening, whereas in other regions, diagnosis is based on a group of recognised multiorgan clinical manifestations, raised sweat chloride concentrations, or CFTR mutations. Disease that is less easily diagnosed, and in some cases affecting only one organ, can be seen in the context of gene variants leading to residual protein function. Management strategies, including augmenting mucociliary clearance and aggressively treating infections, have gradually improved life expectancy for people with cystic fibrosis. However, restoration of CFTR function via new small molecule modulator drugs is transforming the disease for many patients. Clinical trial pipelines are actively exploring many other approaches, which will be increasingly needed as survival improves and as the population of adults with cystic fibrosis increases. Here, we present the current understanding of CFTR mutations, protein function, and disease pathophysiology, consider strengths and limitations of current management strategies, and look to the future of multidisciplinary care for those with cystic fibrosis.

DOI: https://doi.org/10.1016/S0140-6736(20)32542-3
Endocr J. 2021 Jun 08.

Hypoxia-induced thyroid hormone receptor expression regulates cell-cycle progression in renal tubule epithelial cells.

Shunichiro Hanai, Kohei Uchimura, Kazuya Takahashi, Toshihisa Ishii, Takahiko Mitsui, Fumihiko Furuya.

  Hypoxia occurs in the kidneys of chronic kidney disease (CKD) patients, inducing interstitial fibrosis and tubule cell death. Renal tubule cell death is an important determinant of mortality in CKD. We focused on the regulation of cell-cycle-mediated protein expression to prevent cell death under chronic hypoxia in the kidneys of CKD patients. Paraffin-embedded kidney sections from patients with CKD (diabetes nephropathy, nephrosclerosis, or IgA nephropathy) were analyzed for the expression of hypoxia-inducible factor (HIF), thyroid hormone receptor (TR) β, or p21 and levels of interstitial fibrosis. Human renal proximal tubule cells were exposed to hypoxia and analyzed for the expression of HIF, TRβ, or p21 and the cell-cycle stage. TRβ expression was enhanced early on when fibrosis was not fully developed in the tubule cells of CKD patients. HIF1α bound to the TRβ promoter and directly induced its transcription. Further, HIF1α expression induced the expression of TRβ and inhibited cell-cycle progression. In the early stage of kidney injury, TRβ might act as a guardian to prepare and organize cell-cycle proliferation and prevent cell death. While the molecular mechanism that regulates the expression of cell-cycle regulators in renal tubule cells remains controversial, TRβ has strong potential as a new therapeutic target.

Keywords:  Chronic kidney disease; Hypoxia; Thyroid hormone receptor

DOI:  https://doi.org/10.1507/endocrj.EJ21-0245
Hepatology. 2021 Jun 08.

YAP/TAZ suppress drug penetration into hepatocellular carcinoma via stromal activation.

Kyungjoo Cho, Simon Weonsang Ro, Hye Won Lee, Hyuk Moon, Sojung Han, Hye Rim Kim, Sang Hoon Ahn, Jun Yong Park, Do Young Kim.

   BACKGROUD & AIMS: Hepatocellular carcinoma (HCC) is the most predominant type of liver cancer affecting 800,000 people globally each year. Various small-molecule compounds targeting diverse oncogenic signaling pathways have been tested for HCC patients and clinical outcomes were not satisfactory. In this study, we investigated molecular signaling that determines the efficiency of drug delivery into HCC.
APPROACH & RESULTS: Hydrodynamics-based transfection (HT) was performed to develop mouse models for HCC induced by various oncogenes. Mice bearing liver cancer were treated with verteporfin at 5 weeks post HT. Multi-cellular HCC organoid (MCHO) models were established which contained various types of stromal cells, such as hepatic stellate cells, fibroblasts, and endothelial cells together with HCC cells. Tumor organoids were treated with verteporfin and distributions of the drug in the organoids were assessed using fluorescence microscopy. Murine HCC models developed by HT methods showed that a high YAP/TAZ activity in HCC cells impaired verteporfin penetration into the cancer. Activation of tumor stroma was observed in HCC with a high YAP/TAZ activity. Consistent with the findings in the in vivo models of HCC, MCHOs with activated YAP/TAZ signaling showed stromal activation and impaired penetration of verteporfin into the tumor organoids. Inhibition of YAP/TAZ transcriptional activity in HCC cells significantly increased drug penetration into the MCHO.
CONCLUSIONS: Drug delivery into liver cancer is impaired by YAP/TAZ signaling in tumor cells and subsequent activation of stroma by the signaling. Disrupting or targeting activated tumor stroma might improve drug delivery into HCC with an elevated YAP/TAZ activity.

Keywords:  drug penetration; hepatocellular carcinoma; YAP/TAZ; stromal activation; targeted therapy

DOI:  https://doi.org/10.1002/hep.32000
Pharmacol Rep. 2021 Jun 11.

Chronic restraint stress induces changes in the cerebral Galpha 12/13 and Rho-GTPase signaling network.

Katarzyna Rafa-Zabłocka, Agnieszka Zelek-Molik, Beata Tepper, Piotr Chmielarz, Grzegorz Kreiner, Michał Wilczkowski, Irena Nalepa.

   BACKGROUND: Evidence indicates that Gα12, Gα13, and its downstream effectors, RhoA and Rac1, regulate neuronal morphology affected by stress. This study was aimed at investigating whether repeated stress influences the expression of proteins related to the Gα12/13 intracellular signaling pathway in selected brain regions sensitive to the effects of stress. Furthermore, the therapeutic impact of β(1)adrenergic receptors (β1AR) blockade was assessed.
METHODS: Restraint stress (RS) model in mice (2 h/14 days) was used to assess prolonged stress effects on the mRNA expression of Gα12, Gα13, RhoA, Rac1 in the prefrontal cortex (PFC), hippocampus (HIP) and amygdala (AMY). In a separate study, applying RS model in rats (3-4 h/1 day or 14 days), we evaluated stress effects on the expression of Gα12, Gα11, Gαq, RhoA, RhoB, RhoC, Rac1/2/3 in the HIP. Betaxolol (BET), a selective β1AR antagonist, was introduced (5 mg/kg/p.o./8-14 days) in the rat RS model to assess the role of β1AR in stress effects. RT-qPCR and Western Blot were used for mRNA and protein assessments, respectively.
RESULTS: Chronic RS decreased mRNA expression of Gα12 and increased mRNA for Rac1 in the PFC of mice. In the mice AMY, decreased mRNA expression of Gα12, Gα13 and RhoA was observed. Fourteen days of RS exposure increased RhoA protein level in the rats' HIP in the manner dependent on β1AR activity.
CONCLUSIONS: Together, these results suggest that repeated RS affects the expression of genes and proteins known to be engaged in neural plasticity, providing potential targets for further studies aimed at unraveling the molecular mechanisms of stress-related neuropsychiatric diseases.

Keywords:  Chronic stress; G-protein-coupled receptors; Galpha proteins; Mouse brain; Rat brain; Rho GTPases

DOI:  https://doi.org/10.1007/s43440-021-00294-4
PeerJ. 2021 ;9 e11400

Acute kidney disease in hospitalized acute kidney injury patients.

Ping Yan, Xiang-Jie Duan, Yu Liu, Xi Wu, Ning-Ya Zhang, Fang Yuan, Hao Tang, Qian Liu, Ying-Hao Deng, Hong-Shen Wang, Mei Wang, Shao-Bin Duan.

   Background: Acute kidney injury (AKI) and chronic kidney disease (CKD) have become worldwide public health problems, but little information is known about the epidemiology of acute kidney disease (AKD)-a state in between AKI and CKD. We aimed to explore the incidence and outcomes of hospitalized patients with AKD after AKI, and investigate the prognostic value of AKD in predicting 30-day and one-year adverse outcomes.
Methods: A total of 2,556 hospitalized AKI patients were identified from three tertiary hospitals in China in 2015 and followed up for one year.AKD and AKD stage were defined according to the consensus report of the Acute Disease Quality Initiative 16 workgroup. Multivariable regression analyses adjusted for confounding variables were used to examine the association of AKD with adverse outcomes.
Results: AKD occurred in 45.4% (1161/2556) of all AKI patients, 14.5% (141/971) of AKI stage 1 patients, 44.6% (308/691) of AKI stage 2 patients and 79.6% (712/894) of AKI stage 3 patients. AKD stage 1 conferred a greater risk of Major Adverse Kidney Events within 30 days (MAKE30) (odds ratio [OR], 2.36; 95% confidence interval 95% CI [1.66-3.36]) than AKD stage 0 but the association only maintained in AKI stage 3 when patients were stratified by AKI stage. However, compared with AKD stage 0, AKD stage 2-3 was associated with higher risks of both MAKE30 and one-year chronic dialysis and mortality independent of the effects of AKI stage with OR being 31.35 (95% CI [23.42-41.98]) and 2.68 (95% CI [2.07-3.48]) respectively. The association between AKD stage and adverse outcomes in 30 days and one year was not significantly changed in critically ill and non-critically ill AKI patients. The results indicated that AKD is common among hospitalized AKI patients. AKD stage 2-3 provides additional information in predicting 30-day and one-year adverse outcomes over AKI stage. Enhanced follow-up of renal function of these patients may be warranted.

Keywords:  Acute kidney injury; Kidney disease; Mortality; Outcome; Renal dysfunction

DOI:  https://doi.org/10.7717/peerj.11400