scholarly journals SO021REGULATION OF MITOCHONDRIAL FUNCTION BY OVEREXPRESSION OF MITOFUSIN 2 UNDER DIABETES CONDITION IN RAT MESANGIAL CELLS AMELIORATES THE SYNTHESIS OF COLLAGEN IV THROUGH AFFECTING HISTONE MODIFICATIONS AT SPECIFIC CIS-REGULATING ELEMENTS

2016 ◽  
Vol 31 (suppl_1) ◽  
pp. i9-i10
Author(s):  
Wanxin Tang ◽  
Fei Liu ◽  
Xiaolei Chen ◽  
Xiaohong Tang ◽  
Xuhua Mi
Keyword(s):  
Histone Modifications ◽  
Mitochondrial Function ◽  
Mesangial Cells ◽  
Collagen Iv ◽  
Mitofusin 2

scholarly journals Mitofusin 2 attenuates the histone acetylation at collagen IV promoter in diabetic nephropathy

2016 ◽  
Vol 57 (4) ◽  
pp. 233-249 ◽  
Author(s):  
Xuhua Mi ◽  
Wanxin Tang ◽  
Xiaolei Chen ◽  
Fei Liu ◽  
Xiaohong Tang
Keyword(s):  
Diabetic Nephropathy ◽  
Mitochondrial Dysfunction ◽  
Histone Acetylation ◽  
Molecular Mechanisms ◽  
Mesangial Cells ◽  
Collagen Iv ◽  
Mitochondrial Morphology ◽  
Glomerular Mesangial Cells ◽  
Mitofusin 2 ◽  
Protective Function

Extracellular matrix (ECM) increase in diabetic nephropathy (DN) is closely related to mitochondrial dysfunction. The mechanism of protective function of mitofusin 2 (Mfn2) for mitochondria remains largely unknown. In this study, the molecular mechanisms for the effect of Mfn2 on mitochondria and subsequent collagen IV expression in DN were investigated. Ras-binding-deficient mitofusin 2 (Mfn2–Ras(Δ)) were overexpressed in rat glomerular mesangial cells, and then the cells were detected for mitochondrial morphology, cellular reactive oxygen species (ROS), mRNA and protein expression of collagen IV with advanced glycation end-product (AGE) stimulation. Preliminary results reveal that the mitochondrial dysfunction and the increased synthesis of collagen IV after AGE stimulation were reverted by Mfn2–Ras(Δ) overexpression. Bioinformatical computations were performed to search transcriptional factor motifs in the promoter region of collagen IV. Three specific regions for TFAP2A binding were identified, followed by validation with chromatin immunoprecipitation experiments. Knocking down TFAP2A significantly decreased the TF binding in the first two regions and the gene expression of collagen IV. Furthermore, results reveal that Mfn2–Ras(Δ) overexpression significantly mitigated TFAP2A binding and also reverted the histone acetylation at Regions 1 and 2 after AGE stimulation. In streptozotocin-induced diabetic rats, Mfn2–Ras(Δ) overexpression also ameliorated glomerular mesangial lesions with decreased collagen IV expression, accompanied by decreased acetylation and TFAP2A binding at Region 1. In conclusion, this study highlights the pathway by which mitochondria affect the histone acetylation of gene promoter and provides a new potential therapy approach for DN.

Receptor signaling and neutral endopeptidase are involved in the resistance of C-type natriuretic peptide to human mesangial proliferation and collagen-IV expression

2018 ◽  
Vol 66 (5) ◽  
pp. 1.1-9 ◽  
Author(s):  
Huang Huang Luo ◽  
Cheng Wu ◽  
Peng Hu ◽  
Yang Fang Wu ◽  
Dong Dong Zhang ◽  
...  
Keyword(s):  
Natriuretic Peptide ◽  
Mesangial Cells ◽  
Neutral Endopeptidase ◽  
Collagen Iv ◽  
Guanosine Monophosphate ◽  
In Vivo Studies ◽  
Dependent Manner ◽  
Receptor Signaling ◽  
Signal Molecule ◽  
Mesangial Proliferation

C-type natriuretic peptide (CNP) is regarded as a local, paracrine hormone to regulate vascular tone and cell proliferation. Although several in vivo studies have documented that CNP exerts the inhibitory effects on mesangial cells (MCs) proliferation and collagen production, a limited number of studies exist about the resistance of CNP to MCs proliferation in vitro. Besides, whether its receptor signaling and neutral endopeptidase (NEP) are involved remains unclear. In the present study, human MCs were incubated in serum-containing medium in the absence or presence of CNP (0, 10 and 100 pM) for 24, 48 and 72 hours, respectively. CNP administration significantly suppresses MCs proliferation and collagen-IV (Col-IV) expression in a time-dependent and dose-dependent manner. As a down-stream signal molecule of CNP activation, the expressions of natriuretic peptide receptor (NPR)-B, cyclic guanosine monophosphate-dependent protein kinases II and NPR-C were obviously augmented, whereas NEP expression was significantly decreased after CNP treatment. In conclusion, receptor signaling and NEP are involved in the resistance of CNP to human mesangial proliferation and Col-IV expression.

scholarly journals Glucagon-like peptide-1 receptor pathway inhibits extracellular matrix production by mesangial cells through store-operated Ca2+ channel

2019 ◽  
Vol 244 (14) ◽  
pp. 1193-1201 ◽  
Author(s):  
Linjing Huang ◽  
Rong Ma ◽  
Tingting Lin ◽  
Sarika Chaudhari ◽  
Parisa Y Shotorbani ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
High Glucose ◽  
Protein Production ◽  
Matrix Protein ◽  
Mesangial Cells ◽  
Collagen Iv ◽  
Extracellular Matrix Protein ◽  
Human Mesangial Cells ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

Glomerular mesangial cell is the major source of mesangial matrix. Our previous study demonstrated that store-operated Ca2+ channel signaling suppressed extracellular matrix protein production by mesangial cells. Recent studies demonstrated that glucagon-like peptide-1 receptor (GLP-1R) pathway had renoprotective effects. However, the underlying mechanism(s) remains unclear. The present study was aimed to determine if activation of GLP-1R decreased extracellular matrix protein production by mesangial cells through upregulation of store-operated Ca2+ function. Experiments were conducted in cultured human mesangial cells. Liraglutide and exendin 9–39 were used to activate and inhibit GLP-1R, respectively. Store-operated Ca2+ function was estimated by evaluating the SOC-mediated Ca2+ entry (SOCE). We found that liraglutide treatment reduced high glucose-stimulated production of fibronectin and collagen IV. The inhibitory effects of liraglutide were not observed in the presence of exendin 9–39. Exendin-4, another GLP-1R agonist also blunted high glucose-stimulated fibronectin and collagen IV production. Treatment of human mesangial cells with liraglutide for 24 h significantly attenuated the high glucose-induced reduction of Orai1 protein. Consistently, Ca2+ imaging experiments showed that the inhibition of high glucose on SOCE was significantly attenuated by liraglutide. However, in the presence of exendin 9–39, liraglutide failed to reverse the high glucose effect. Furthermore, liraglutide effects on fibronectin and collagen IV protein abundance were significantly attenuated by GSK-7975A, a selective blocker of store-operated Ca2+. Taken together, our findings suggest that GLP-1R signaling inhibited high glucose-induced extracellular matrix protein production in mesangial cells by restoring store-operated Ca2+ function. Impact statement Diabetic kidney disease continues to be a major challenge to health care system in the world. There are no known therapies currently available that can cure the disease. The present study provided compelling evidence that activation of GLP-1R inhibited extracellular matrix protein production by glomerular mesangial cells. We further showed that the beneficial effect of GLP-1R was attributed to upregulation of store-operated Ca2+ channel function. Therefore, we identified a novel mechanism contributing to the renal protective effects of GLP-1R pathway. Activation of GLP-1R pathway and/or store-operated Ca2+ channel signaling in MCs could be an option for patients with diabetic kidney disease.

scholarly journals The Protective Effect of Alpha-Mangostin against Cisplatin-Induced Cell Death in LLC-PK1 Cells is Associated to Mitochondrial Function Preservation

Antioxidants ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 133 ◽  
Author(s):  
Laura María Reyes-Fermín ◽  
Sabino Hazael Avila-Rojas ◽  
Omar Emiliano Aparicio-Trejo ◽  
Edilia Tapia ◽  
Isabel Rivero ◽  
...  
Keyword(s):  
Cell Death ◽  
Mitochondrial Function ◽  
Anion Channel ◽  
Laboratory Culture ◽  
Mitochondrial Morphology ◽  
Protective Effects ◽  
Mitofusin 2 ◽  
Mitochondrial Mass ◽  
Protein Levels ◽  
Function Preservation

Cis-dichlorodiammineplatinum II (CDDP) is a chemotherapeutic agent that induces nephrotoxicity by different mechanisms, including oxidative stress, mitochondrial dysfunction, autophagy, and endoplasmic reticulum stress. This study aimed to evaluate if the protective effects of the antioxidant alpha-mangostin (αM) in CDDP-induced damage in proximal tubule Lilly laboratory culture porcine kidney (LLC-PK1) cells, are related to mitochondrial function preservation. It was found that αM co-incubation prevented CDDP-induced cell death. Furthermore, αM prevented the CDDP-induced decrease in cell respiratory states, in the maximum capacity of the electron transfer system (E) and in the respiration associated to oxidative phosphorylation (OXPHOS). CDDP also decreased the protein levels of voltage dependence anion channel (VDAC) and mitochondrial complex subunits, which together with the reduction in E, the mitofusin 2 decrease and the mitochondrial network fragmentation observed by MitoTracker Green, suggest the mitochondrial morphology alteration and the decrease in mitochondrial mass induced by CDDP. CDDP also induced the reduction in mitochondrial biogenesis observed by transcription factor A, mitochondria (TFAM) decreased protein-level and the increase in mitophagy. All these changes were prevented by αM. Taken together, our results imply that αM’s protective effects in CDDP-induced toxicity in LLC-PK1 cells are associated to mitochondrial function preservation.

Abstract P016: GYY4137, a Hydrogen Sulfide Donor, Mitigates Ang II-induced Extracellular Matrix Remodeling in Glomerular Endothelial and Mesangial Cells

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Matthew Amin ◽  
Sathnur Pushpakumar ◽  
Sourav Kundu ◽  
Geetansh Tyagi ◽  
Aaron Tyagi ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Hydrogen Sulfide ◽  
Mesangial Cells ◽  
Collagen Iv ◽  
Tissue Inhibitors Of Metalloproteinases ◽  
Matrix Remodeling ◽  
Ang Ii ◽  
Hypertensive Nephropathy ◽  
Glomerular Endothelial Cells

Hypertensive nephropathy is associated with progressive alteration of extracellular matrix (ECM) components. Both mesangial and glomerular endothelial cells have the ability to synthesize and degrade ECM proteins such as collagens by changes in the activity of matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs). Endo180 is an extracellular fibronectin type II domain involved in lysosomal degradation of collagen which has been shown to mitigate renal fibrosis. More recently, hydrogen sulfide (H2S) has also been shown to mitigate hypertensive renal remodeling, however, its mechanism remains unclear. In this study, our aim was to investigate whether Angiotensin-II (Ang II) treatment alters the expression of Endo180, MMPs and TIMPs leading to dysregulation of collagen metabolism and whether GYY4137 (H2S donor) restores their levels to achieve homeostasis. Mesangial and mouse glomerular endothelial cells (MCs and MGECs respectively) were treated without or with Ang II (200 nM) and GYY4137 (250 μM) for 48hrs. Cell lysates were analyzed for MMP-13, -14, TIMP-1, Endo180, and collagen IV by Western blot, RT-PCR, and immunohistochemistry. In MGECs, Ang II treatment compared to its control decreased MMP-13/TIMP-1 ratio (0.75±0.44 vs. 2.48 ±0.73), and upregulated MMP-14/TIMP-1 ratio (0.64±2.10 vs. 0.96±1.47), and collagen IV (0.77±0.07 vs. 0.58±0.06). GYY4137 treatment mitigated these changes. In contrast, Ang II treatment in MCs decreased Endo180 compared to control (0.72±0.04 vs. 1.07±0.23), but did not alter the expression of MMP-13/TIMP-1, MMP-14/TIMP-1 ratios, and collagen IV level compared to control or MGECs. Similarly, immunostaining showed downregulation of MMP-13 and Endo180 in Ang II treated MGECs which was normalized following GYY4137 treatment. Endo180 was also normalized in MCs following GYY4137 treatment however, there was no change in MMP-14/TIMP-1 ratio or collagen IV level. We conclude that Ang II treatment causes adverse ECM remodeling in MGECs via downregulation of Endo180 and MMP-13 and upregulation of MMP-14 and TIMP-1 and in MCs by decreasing Endo180, and GYY4137 mitigates these changes in part, by modulating Endo180/MMP/TIMP pathway.

scholarly journals Negative regulation of Smad1 pathway and collagen IV expression by store-operated Ca2+ entry in glomerular mesangial cells

2017 ◽  
Vol 312 (6) ◽  
pp. F1090-F1100 ◽  
Author(s):  
Peiwen Wu ◽  
Yuezhong Ren ◽  
Yuhong Ma ◽  
Yanxia Wang ◽  
Hui Jiang ◽  
...  
Keyword(s):  
High Glucose ◽  
Protein Production ◽  
Mesangial Cells ◽  
Collagen Iv ◽  
Glomerular Mesangial Cells ◽  
Protein Activation ◽  
Nanoparticle Delivery ◽  
Interfering Rna ◽  
Glomerular Extracellular Matrix

Collagen IV (Col IV) is a major component of expanded glomerular extracellular matrix in diabetic nephropathy and Smad1 is a key molecule regulating Col IV expression in mesangial cells (MCs). The present study was conducted to determine if Smad1 pathway and Col IV protein abundance were regulated by store-operated Ca2+ entry (SOCE). In cultured human MCs, pharmacological inhibition of SOCE significantly increased the total amount of Smad1 protein. Activation of SOCE blunted high-glucose-increased Smad1 protein content. Treatment of human MCs with ANG II at 1 µM for 15 min, high glucose for 3 days, or TGF-β1 at 5 ng/ml for 30 min increased the level of phosphorylated Smad1. However, the phosphorylation of Smad1 by those stimuli was significantly attenuated by activation of SOCE. Knocking down Smad1 reduced, but expressing Smad1 increased, the amount of Col IV protein. Furthermore, activation of SOCE significantly attenuated high-glucose-induced Col IV protein production, and blockade of SOCE substantially increased the abundance of Col IV. To further verify those in vitro findings, we downregulated SOCE specifically in MCs in mice using small-interfering RNA (siRNA) against Orai1 (the channel protein mediating SOCE) delivered by the targeted nanoparticle delivery system. Immunohistochemical examinations showed that expression of both Smad1 and Col IV proteins was significantly greater in the glomeruli with positively transfected Orai1 siRNA compared with the glomeruli from the mice without Orai1 siRNA treatment. Taken together, our results indicate that SOCE negatively regulates the Smad1 signaling pathway and inhibits Col IV protein production in MCs.

Mesangial cell NADPH oxidase upregulation in high glucose is protein kinase C dependent and required for collagen IV expression

2006 ◽  
Vol 290 (2) ◽  
pp. F345-F356 ◽  
Author(s):  
L. Xia ◽  
H. Wang ◽  
H. J. Goldberg ◽  
S. Munk ◽  
I. G. Fantus ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
High Glucose ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Fold Increase ◽  
Collagen Iv ◽  
Oxidase Inhibitor ◽  
Ros Generation ◽  
Rt Pcr ◽  
Diabetic Glomerulosclerosis

Excess collagen IV expression by mesangial cells contributes to diabetic glomerulosclerosis. We hypothesized that in high glucose reactive oxygen species (ROS) generation by NADPH oxidase is PKC dependent and required for collagen IV expression by mesangial cells. In rat mesangial cells cultured in 5 mM (NG) or 25 mM d-glucose (HG), RT-PCR and Western immunoblotting detected p22phox and p47phox mRNA and protein, respectively. Quantitative real-time RT-PCR analyzed collagen IV mRNA. With the use of confocal microscopy, ROS were detected with dichlorofluorescein and intracellular collagen IV by immunofluorescence. In HG, ROS were generated within 1 h, sustained up to 48 h, and prevented by a NADPH oxidase inhibitor, diphenylenechloride iodonium (DPI), or a conventional PKC isozyme inhibitor, Gö6976. In NG, phorbol myristate acetate stimulated ROS generation that was inhibited with DPI. In HG, expression of p22phox and p47phox was increased within 3 to 6 h and inhibited by Gö6976. In HG, Gö6976 or transfection with antisense against p22phox reversed the 1.8-fold increase in collagen IV mRNA. In HG, the antioxidants Tempol or Tiron, or transfection with antisense against p22phox or p47phox, prevented ROS generation and the 2.3-fold increase in collagen IV protein. Increased mitochondrial redox potential in HG was unaffected by transfection with antisense against p22phox. We conclude that in HG, mesangial cell ROS generation by upregulated NADPH oxidase is dependent on conventional PKC isozymes and also required for collagen IV expression.

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