bims-noxint 2022-05-01 papers

Issue of 2022–05–01
four papers selected by
Laia Caja Puigsubira, Uppsala University

Life Sci. 2022 Apr 21. pii: S0024-3205(22)00267-3. [Epub ahead of print] 120567

Deficiency of NARFL increases transcription of NADPH oxidases and ROS production impairing the function of endothelial cells.

Hong-Zhou Liu, Jie Peng, Mei-Zhen Zhao, Ying Xu.

AIMS: Nuclear prelamin A recognition factor-like (NARFL) is involved in cytosolic iron‑sulfur (FeS) protein biogenesis and cellular defense against oxidative stress. Previous study reported that increased oxidative stress and subintestinal vessel (SIV) malformation in narfl knockout zebrafish. However, the underlying mechanism of oxidative stress caused by NARFL deficiency remains unclear. The present study was sought to investigate the function of NARFL in endothelial cells.
METHODS: NARFL knockdown assay was performed in two cell lines and NADPH oxidase (Nox) were measured using Western blotting. Nox inhibitors were selected for assessing the potential sources of ROS generation. Cell migration was detected using wound healing assay and transwell assay. Cell cycle was analyzed using flow cytometry. Promoter activity assay and Chromatin immunoprecipitation (ChIP) assay were chosen for investigating the molecular mechanism of Nox transcription.
RESULTS: NARFL deficiency resulted in upregulated expressions of Nox2, Nox4, and p47phox and increased reactive oxygen species (ROS) levels in endothelial cells. Nox2 knockdown reversed the effects and improved endothelial dysfunctions caused by NARFL deficiency. Chromatin immunoprecipitation (ChIP) experiments revealed that NARFL knockdown increased the recruitment of RNA polymerase II and modification of histones at the promoter sites of Nox2 and Nox4.
CONCLUSION: NARFL knockdown induced the transcriptional activation of Nox2 and Nox4, which resulted in increased ROS levels and impaired endothelial functions.

Keywords: Endothelial cells; NADPH oxidase; Nuclear prelamin A recognition factor-like; Oxidative stress; Reactive oxygen species

DOI: https://doi.org/10.1016/j.lfs.2022.120567

Basic Res Cardiol. 2022 Apr 25. 117(1): 24

NADPH oxidase 4 contributes to TRPV4-mediated endothelium-dependent vasodilation in human arterioles by regulating protein phosphorylation of TRPV4 channels.

Yangjing Xie, Yoshinori Nishijima, Natalya S Zinkevich, Ankush Korishettar, Juan Fang, Angela J Mathison, Michael T Zimmermann, David A Wilcox, David D Gutterman, Yuxian Shen, David X Zhang.

Impaired endothelium-dependent vasodilation has been suggested to be a key component of coronary microvascular dysfunction (CMD). A better understanding of endothelial pathways involved in vasodilation in human arterioles may provide new insight into the mechanisms of CMD. The goal of this study is to investigate the role of TRPV4, NOX4, and their interaction in human arterioles and examine the underlying mechanisms. Arterioles were freshly isolated from adipose and heart tissues obtained from 71 patients without coronary artery disease, and vascular reactivity was studied by videomicroscopy. In human adipose arterioles (HAA), ACh-induced dilation was significantly reduced by TRPV4 inhibitor HC067047 and by NOX 1/4 inhibitor GKT137831, but GKT137831 did not further affect the dilation in the presence of TRPV4 inhibitors. GKT137831 also inhibited TRPV4 agonist GSK1016790A-induced dilation in HAA and human coronary arterioles (HCA). NOX4 transcripts and proteins were detected in endothelial cells of HAA and HCA. Using fura-2 imaging, GKT137831 significantly reduced GSK1016790A-induced Ca2+ influx in the primary culture of endothelial cells and TRPV4-WT-overexpressing human coronary artery endothelial cells (HCAEC). However, GKT137831 did not affect TRPV4-mediated Ca2+ influx in non-phosphorylatable TRPV4-S823A/S824A-overexpressing HCAEC. In addition, treatment of HCAEC with GKT137831 decreased the phosphorylation level of Ser824 in TRPV4. Finally, proximity ligation assay (PLA) revealed co-localization of NOX4 and TRPV4 proteins. In conclusion, both TRPV4 and NOX4 contribute to ACh-induced dilation in human arterioles from patients without coronary artery disease. NOX4 increases TRPV4 phosphorylation in endothelial cells, which in turn enhances TRPV4-mediated Ca2+ entry and subsequent endothelium-dependent dilation in human arterioles.

Keywords: Coronary artery disease; Human arterioles; NADPH oxidase; Transient receptor potential vanilloid; Vasodilation

DOI: https://doi.org/10.1007/s00395-022-00932-9

J Mol Neurosci. 2022 Apr 27.

Mitochondrial Dysfunction Contributes To Zinc-induced Neurodegeneration: a Link with NADPH Oxidase.

Amit Kumar Chauhan, Namrata Mittra, Garima Singh, Chetna Singh.

Mitochondrial dysfunction and nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) are the major sources of augmentation in free radical generation leading to neurodegeneration. Although NADPH oxidase involvement is reported in zinc (Zn)-induced neurodegeneration, contribution of the mitochondrial dysfunction and its association with NADPH oxidase are not known. Therefore, the study was aimed to decipher the role of mitochondrial dysfunction and its link with NADPH oxidase in Zn-induced Parkinsonism. Zn reduced the motor activities, the number of tyrosine hydroxylase (TH)-positive neurons, and level of TH protein. Conversely, Zn increased the mitochondrial reactive oxygen species (ROS) production, lipid peroxidation (LPO), and superoxide dismutase (SOD) activity and reduced the mitochondrial membrane potential and catalytic activities of complex I and III. Zn also attenuated B-cell lymphoma-2 (Bcl-2) and pro-caspase 9/3 levels and augmented the translocation of cytosolic Bcl-2 associated X (Bax) protein to the mitochondria and cytochrome c release into cytosol from the mitochondria. Cyclosporine A, a mitochondrial outer membrane transition pore inhibitor and apocynin, a NADPH oxidase inhibitor, independently, ameliorated the Zn-induced changes. Similarly, Zn reduced cell viability through mitochondrial dysfunction and apoptosis in human neuroblastoma SH-SY5Y cells, which were notably normalized in the presence of cyclosporine or apocynin. The results demonstrate that mitochondrial dysfunction contributes to Zn-induced neurodegeneration, which could be partially aided by the NADPH oxidase.

Keywords: Mitochondrial dysfunction; NADPH oxidase; Neurodegeneration; Zinc

DOI: https://doi.org/10.1007/s12031-022-02008-8

Eur J Clin Invest. 2022 Apr 30. e13807

Liraglutide treatment attenuates inflammation markers in the cardiac, cerebral and renal microvasculature in streptozotocin-induced diabetic rats.

U Baylan, A Korn, R W Emmens, C G Schalkwijk, H Wm Niessen, P Aj Krijnen, S Simsek.

BACKGROUND: Diabetes mellitus (DM) induces cardiac and cerebral microvascular dysfunction via increased glycation, oxidative stress and endothelial activation. Liraglutide, a glucagon-like peptide-1 analogue, inhibited NOX2 and adhesion molecules in isolated endothelial cells. Here we have studied how Liraglutide affects advanced glycation, NOX expression and inflammation of the cardiac, cerebral and renal microvasculature in diabetic rats.
METHODS: DM was induced in Sprague-Dawley rats (n=15) via intraperitoneal streptozotocin (STZ) injection (60 mg/kg body weight). 10 control rats remained non-diabetic. From day 9 post-STZ injection, Liraglutide (200 μg/kg bodyweight; n=7) or vehicle (n=8) was injected subcutaneously daily until termination on day 29. The advanced glycation end-product N-ε-(carboxymethyl)lysine (CML), NOX2, NOX4, ICAM-1 and VCAM-1 were subsequently immunohistochemically analysed and quantified to compare Liraglutide treatment to placebo.
RESULTS: In the heart, Liraglutide treatment significantly reduced the DM-increased scores/cm2 for CML in both ventricles (from 253±53 to 72±12; p=0.003) and atria (343±29 to 122±8; p=0.0001) as well as for NOX2, ICAM-1 and VCAM-1, but not for NOX4. Also in the cerebrum and cerebellum of the brain, Liraglutide significantly reduced the scores/cm2 for CML (to 60±7 (p=0.0005) and 47±13 (p=0.02) respectively) as well as for NOX2 and NOX4. In the kidney the DM-induced expression of ICAM-1 and VCAM-1 was decreased in the blood vessels and glomeruli by Liraglutide treatment. Liraglutide did not affect blood glucose levels or body weight.
CONCLUSIONS: Our study implies that Liraglutide protects the cardiac, cerebral and renal microvasculature against diabetes-induced dysfunction, independent of lowering blood glucose in a type 1 diabetes rat model.

Keywords: Advanced glycation endproducts; CML; Diabetes mellitus; GLP-1 analogue; ICAM-1 (CD54); Liraglutide; NADPH-oxidases (NOX); VCAM-1 (CD106); cerebral vasculature; intramyocardial vasculature; renal vasculature

DOI: https://doi.org/10.1111/eci.13807