scholarly journals Activation of the Nrf2-ARE Pathway Ameliorates Hyperglycemia-Mediated Mitochondrial Dysfunction in Podocytes Partly Through Sirt1

2018 ◽  
Vol 48 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Qunzi Zhang ◽  
Qiongxia Deng ◽  
Jun Zhang ◽  
JianTing Ke ◽  
Ye Zhu ◽  
...  
Keyword(s):  
Mitochondrial Dysfunction ◽  
Structural Damage ◽  
Antioxidant Response ◽  
Sirtuin 1 ◽  
Small Interfering Rnas ◽  
Matrix Deposition ◽  
Mitochondrial Superoxide ◽  
Study Results ◽  
Oxidative Pathway ◽  
Nrf2 Expression

Background/Aims: Previously we have shown that activation of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-antioxidant response element (ARE) attenuated hyperglycemia-induced damage in podocytes, but the molecular mechanism remains unknown. Methods: Tert-butylhydroquinone (t-BHQ) and small interfering RNAs (siRNAs) were used to regulate Nrf2 expression, while nicotinamide and siRNAs were used to regulate sirtuin 1 (Sirt1) activity and expression, respectively. Mitochondrial superoxide, membrane potential and ATP levels were measured to assess changes in mitochondrial function. Nephrin and synaptopodin expression were measured by western blot analysis. Human podocytes and db/db diabetic mice were used in this study. Results: t-BHQ pretreatment of human podocytes exposed to high glucose (HG) alleviated mitochondrial dysfunction, enhanced the expression of Sirt1, nephrin and synaptopodin and lowered BSA permeability compared with podocytes exposed to HG without t-BHQ pretreatment (p< 0.05). Human podocytes exposed to HG had more severe mitochondrial dysfunction, lower expression of Sirt1, synaptopodin and nephrin and higher BSA permeability than podocytes exposed to HG when Nrf2 expression was downregulated by siRNAs (p< 0.05). The protection provided by activation of the Nrf-ARE pathway in podocytes exposed to HG was partially diminished when Sirt1 expression or activity was decreased by siRNAs or inhibitor compared with podocytes exposed to HG and pretreated with t-BHQ (p< 0.05). When nicotinamide and t-BHQ were both administered to db/db mice, we observed higher levels of urinary albumin/creatinine, lower nephrin and synaptopodin expression, more severe mesangial matrix deposition, collagen deposition on pathological slides and mitochondrial structural damage in podocytes compared to db/db mice treated only with t-BHQ. Conclusions: Our findings suggest that crosstalk between Sirt1 and the Nrf2-ARE anti-oxidative pathway forms a positive feedback loop and that protection provided by t-BHQ activation of the Nrf2-ARE pathway in db/db mice is partly dependent on Sirt1.

scholarly journals Aqueous Extract of Pepino Leaves Ameliorates Palmitic Acid-Induced Hepatocellular Lipotoxicity via Inhibition of Endoplasmic Reticulum Stress and Apoptosis

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 903
Author(s):  
Jen-Ying Hsu ◽  
Hui-Hsuan Lin ◽  
Charng-Cherng Chyau ◽  
Zhi-Hong Wang ◽  
Jing-Hsien Chen
Keyword(s):  
Fatty Acid ◽  
Palmitic Acid ◽  
Er Stress ◽  
Lipid Accumulation ◽  
Hepg2 Cells ◽  
Target Genes ◽  
Liver Lipid ◽  
Antioxidant Response ◽  
Long Chain Fatty Acid ◽  
Nrf2 Expression

Saturated fatty acid is one of the important nutrients, but contributes to lipotoxicity in the liver, causing hepatic steatosis. Aqueous pepino leaf extract (AEPL) in the previous study revealed alleviated liver lipid accumulation in metabolic syndrome mice. The study aimed to investigate the mechanism of AEPL on saturated long-chain fatty acid-induced lipotoxicity in HepG2 cells. Moreover, the phytochemical composition of AEPL was identified in the present study. HepG2 cells treated with palmitic acid (PA) were used for exploring the effect of AEPL on lipid accumulation, apoptosis, ER stress, and antioxidant response. The chemical composition of AEPL was analyzed by HPLC-ESI-MS/MS. AEPL treatment reduced PA-induced ROS production and lipid accumulation. Further molecular results revealed that AEPL restored cytochrome c in mitochondria and decreased caspase 3 activity to cease apoptosis. In addition, AEPL in PA-stressed HepG2 cells significantly reduced the ER stress and suppressed SREBP-1 activation for decreasing lipogenesis. For defending PA-induced oxidative stress, AEPL promoted Nrf2 expression and its target genes, SOD1 and GPX3, expressions. The present study suggested that AEPL protected from PA-induced lipotoxicity through reducing ER stress, increasing antioxidant ability, and inhibiting apoptosis. The efficacy of AEPL on lipotoxicity was probably concerned with kaempferol and isorhamnetin derived compounds.

scholarly journals NLRP3 Deficiency Attenuates Renal Fibrosis and Ameliorates Mitochondrial Dysfunction in a Mouse Unilateral Ureteral Obstruction Model of Chronic Kidney Disease

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Honglei Guo ◽  
Xiao Bi ◽  
Ping Zhou ◽  
Shijian Zhu ◽  
Wei Ding
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Mitochondrial Dysfunction ◽  
Ureteral Obstruction ◽  
Renal Fibrosis ◽  
Unilateral Ureteral Obstruction ◽  
Tubulointerstitial Fibrosis ◽  
Mitochondrial Morphology ◽  
Glomerular Injury ◽  
Matrix Deposition

Background and Aims. The nucleotide-binding domain and leucine-rich repeat containing PYD-3 (NLRP3) inflammasome has been implicated in the pathogenesis of chronic kidney disease (CKD); however, its exact role in glomerular injury and tubulointerstitial fibrosis is still undefined. The present study was performed to identify the function of NLRP3 in modulating renal injury and fibrosis and the potential involvement of mitochondrial dysfunction in the murine unilateral ureteral obstruction (UUO) model of CKD. Methods. Employing wild-type (WT) and NLRP3−/− mice with or without UUO, we evaluated renal structure, tissue injury, and mitochondrial ultrastructure, as well as expression of some vital molecules involved in the progression of fibrosis, apoptosis, inflammation, and mitochondrial dysfunction. Results. The severe glomerular injury and tubulointerstitial fibrosis induced in WT mice by UUO was markedly attenuated in NLRP3−/− mice as evidenced by blockade of extracellular matrix deposition, decreased cell apoptosis, and phenotypic alterations. Moreover, NLRP3 deletion reversed UUO-induced impairment of mitochondrial morphology and function. Conclusions. NLRP3 deletion ameliorates mitochondrial dysfunction and alleviates renal fibrosis in a murine UUO model of CKD.

Methane biogenesis during sodium azide-induced chemical hypoxia in rats

2013 ◽  
Vol 304 (2) ◽  
pp. C207-C214 ◽  
Author(s):  
Eszter Tuboly ◽  
Andrea Szabó ◽  
Dénes Garab ◽  
Gábor Bartha ◽  
Ágnes Janovszky ◽  
...  
Keyword(s):  
Mitochondrial Dysfunction ◽  
Sodium Azide ◽  
Methane Production ◽  
Structural Damage ◽  
Bacterial Flora ◽  
Laser Scanning Microscopy ◽  
Whole Body ◽  
Oral Antibiotic ◽  
Methane Generation ◽  
Chemical Hypoxia

Previous studies demonstrated methane generation in aerobic cells. Our aims were to investigate the methanogenic features of sodium azide (NaN3)-induced chemical hypoxia in the whole animal and to study the effects of l-α-glycerylphosphorylcholine (GPC) on endogenous methane production and inflammatory events as indicators of a NaN3-elicited mitochondrial dysfunction. Group 1 of Sprague-Dawley rats served as the sham-operated control; in group 2, the animals were treated with NaN3 (14 mg·kg−1·day−1 sc) for 8 days. In group 3, the chronic NaN3 administration was supplemented with daily oral GPC treatment. Group 4 served as an oral antibiotic-treated control (rifaximin, 10 mg·kg−1·day−1) targeting the intestinal bacterial flora, while group 5 received this antibiotic in parallel with NaN3 treatment. The whole body methane production of the rats was measured by means of a newly developed method based on photoacoustic spectroscopy, the microcirculation of the liver was observed by intravital videomicroscopy, and structural changes were assessed via in vivo fluorescent confocal laser-scanning microscopy. NaN3 administration induced a significant inflammatory reaction and methane generation independently of the methanogenic flora. After 8 days, the hepatic microcirculation was disturbed and the ATP content was decreased, without major structural damage. Methane generation, the hepatic microcirculatory changes, and the increased tissue myeloperoxidase and xanthine oxidoreductase activities were reduced by GPC treatment. In conclusion, the results suggest that methane production in mammals is connected with hypoxic events associated with a mitochondrial dysfunction. GPC is protective against the inflammatory consequences of a hypoxic reaction that might involve cellular or mitochondrial methane generation.

Functional Organization of the Endoplasmic Reticulum Dictates the Susceptibility of Target Cells to Arsenite-Induced Mitochondrial Superoxide Formation, Mitochondrial Dysfunction and Apoptosis

2021 ◽  
Author(s):  
Andrea Guidarelli ◽  
Alessia Catalani ◽  
Ersilia Varone ◽  
Stefano Fumagalli ◽  
Ester Zito ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Mitochondrial Dysfunction ◽  
Functional Organization ◽  
Close Contact ◽  
Cell Types ◽  
Target Cells ◽  
Close Apposition ◽  
Mitochondrial Superoxide ◽  
Low Concentrations ◽  
Absolute Requirement

Abstract Arsenite induces many critical effects associated with the formation of reactive oxygen species (ROS) through different mechanisms. We focused on the Ca2+-dependent mitochondrial superoxide (mitoO2-.) formation and addressed questions on the effects of low concentrations of arsenite on the mobilization of the cation from the endoplasmic reticulum and the resulting mitochondrial accumulation. Using various differentiated and undifferentiated cell types uniquely expressing the inositol-1, 4, 5-triphosphate receptor (IP3R), or both the IP3R and the ryanodine receptor (RyR), we determined that expression of this second Ca2+ channel is an absolute requirement for mitoO2-. formation and for the ensuing mitochondrial dysfunction and downstream apoptosis. In arsenite-treated cells, RyR was recruited after IP3R stimulation and agonist studies indicated that in these cells RyR is in close apposition with mitochondria. It was also interesting to observe that arsenite fails to promote mitochondrial Ca2+ accumulation, mitoO2-. formation, mitochondrial toxicity in RyR-devoid cells, in which the IP3R is in close contact with the mitochondria. We therefore conclude that low dose arsenite-induced mitoO2- formation and the resulting mitochondrial dysfunction and toxicity, are prerequisite of cell types expressing the RyR in close apposition with mitochondria.

scholarly journals Centella asiatica Attenuates Mitochondrial Dysfunction and Oxidative Stress in Aβ-Exposed Hippocampal Neurons

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Nora E. Gray ◽  
Jonathan A. Zweig ◽  
Donald G. Matthews ◽  
Maya Caruso ◽  
Joseph F. Quinn ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Function ◽  
Hippocampal Neurons ◽  
Neuroblastoma Cells ◽  
Water Extract ◽  
Centella Asiatica ◽  
Antioxidant Response ◽  
And Oxidative Stress

Centella asiatica has been used for centuries to enhance memory. We have previously shown that a water extract of Centella asiatica (CAW) protects against the deleterious effects of amyloid-β (Aβ) in neuroblastoma cells and attenuates Aβ-induced cognitive deficits in mice. Yet, the neuroprotective mechanism of CAW has yet to be thoroughly explored in neurons from these animals. This study investigates the effects of CAW on neuronal metabolism and oxidative stress in isolated Aβ-expressing neurons. Hippocampal neurons from amyloid precursor protein overexpressing Tg2576 mice and wild-type (WT) littermates were treated with CAW. In both genotypes, CAW increased the expression of antioxidant response genes which attenuated the Aβ-induced elevations in reactive oxygen species (ROS) and lipid peroxidation in Tg2576 neurons. CAW also improved mitochondrial function in both genotypes and increased the expression of electron transport chain enzymes and mitochondrial labeling, suggesting an increase in mitochondrial content. These data show that CAW protects against mitochondrial dysfunction and oxidative stress in Aβ-exposed hippocampal neurons which could contribute to the beneficial effects of the extract observed in vivo. Since CAW also improved mitochondrial function in the absence of Aβ, these results suggest a broader utility for other conditions where neuronal mitochondrial dysfunction occurs.

scholarly journals Testosterone Decreases Placental Mitochondrial Content and Cellular Bioenergetics

Biology ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 176 ◽  
Author(s):  
Jay S. Mishra ◽  
Chellakkan S. Blesson ◽  
Sathish Kumar
Keyword(s):  
Mitochondrial Dysfunction ◽  
Copy Number ◽  
Structural Damage ◽  
Plasma Testosterone ◽  
Sprague Dawley ◽  
Pregnant Rats ◽  
Testosterone Levels ◽  
Mitochondrial Copy Number ◽  
Maternal Testosterone

Placental mitochondrial dysfunction plays a central role in the pathogenesis of preeclampsia. Since preeclampsia is a hyperandrogenic state, we hypothesized that elevated maternal testosterone levels induce damage to placental mitochondria and decrease bioenergetic profiles. To test this hypothesis, pregnant Sprague–Dawley rats were injected with vehicle or testosterone propionate (0.5 mg/kg/day) from gestation day (GD) 15 to 19. On GD20, the placentas were isolated to assess mitochondrial structure, copy number, ATP/ADP ratio, and biogenesis (Pgc-1α and Nrf1). In addition, in vitro cultures of human trophoblasts (HTR-8/SVneo) were treated with dihydrotestosterone (0.3, 1.0, and 3.0 nM), and bioenergetic profiles using seahorse analyzer were assessed. Testosterone exposure in pregnant rats led to a 2-fold increase in plasma testosterone levels with an associated decrease in placental and fetal weights compared with controls. Elevated maternal testosterone levels induced structural damage to the placental mitochondria and decreased mitochondrial copy number. The ATP/ADP ratio was reduced with a parallel decrease in the mRNA and protein expression of Pgc-1α and Nrf1 in the placenta of testosterone-treated rats compared with controls. In cultured trophoblasts, dihydrotestosterone decreased the mitochondrial copy number and reduced PGC-1α, NRF1 mRNA, and protein levels without altering the expression of mitochondrial fission/fusion genes. Dihydrotestosterone exposure induced significant mitochondrial energy deficits with a dose-dependent decrease in basal respiration, ATP-linked respiration, maximal respiration, and spare respiratory capacity. In summary, our study suggests that the placental mitochondrial dysfunction induced by elevated maternal testosterone might be a potential mechanism linking preeclampsia to feto-placental growth restriction.

scholarly journals Chronic dietary supplementation of proanthocyanidins corrects the mitochondrial dysfunction of brown adipose tissue caused by diet-induced obesity in Wistar rats

2011 ◽  
Vol 107 (2) ◽  
pp. 170-178 ◽  
Author(s):  
David Pajuelo ◽  
Helena Quesada ◽  
Sabina Díaz ◽  
Anabel Fernández-Iglesias ◽  
Anna Arola-Arnal ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Function ◽  
Citrate Synthase ◽  
Sirtuin 1 ◽  
Male Rats ◽  
Diet Induced Obesity ◽  
Brown Adipose

The present study aims to determine the effects of grape seed proanthocyanidin extract (GSPE) on brown adipose tissue (BAT) mitochondrial function in a state of obesity induced by diet. Wistar male rats were fed with a cafeteria diet (Cd) for 4 months; during the last 21 d, two groups were treated with doses of 25 and 50 mg GSPE/kg body weight. In the BAT, enzymatic activities of citrate synthase, cytochrome c oxidase (COX) and ATPase were determined and gene expression was analysed by real-time PCR. The mitochondrial function of BAT was determined in fresh mitochondria by high-resolution respirometry using both pyruvate and carnitine–palmitoyl-CoA as substrates. The results show that the Cd causes an important decrease in the gene expression of sirtuin 1, nuclear respiratory factor 1, isocitrate dehydrogenase 3γ and COX5α and, what is more telling, decreases the levels of mitochondrial respiration both with pyruvate and canitine–palmitoyl-CoA. Most of these parameters, which are indicative of mitochondrial dysfunction due to diet-induced obesity, are improved by chronic supplementation of GSPE. The beneficial effects caused by the administration of GSPE are exhibited as a protection against weight gain, in spite of the Cd the rats were fed. These data indicate that chronic consumption of a moderate dose of GSPE can correct an energy imbalance in a situation of diet-induced obesity, thereby improving the mitochondrial function and thermogenic capacity of the BAT.

scholarly journals Sirtuin 1 suppresses mitochondrial dysfunction of ischemic mouse livers in a mitofusin 2-dependent manner

2015 ◽  
Vol 23 (2) ◽  
pp. 279-290 ◽  
Author(s):  
T G Biel ◽  
S Lee ◽  
J A Flores-Toro ◽  
J W Dean ◽  
K L Go ◽  
...  
Keyword(s):  
Mitochondrial Dysfunction ◽  
Sirtuin 1 ◽  
Dependent Manner ◽  
Mitofusin 2
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