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Protective role of PGC-1α in diabetic nephropathy is associated with the inhibition of ROS through mitochondrial dynamic remodeling.

Guo K, Lu J, Huang Y, Wu M, Zhang L, Yu H, Zhang M, Bao Y, He JC, Chen H, Jia W - PLoS ONE (2015)

Bottom Line: This was associated with an increase in ROS generation and mesangial cell hypertrophy.These data suggest that PGC-1α may protect DN via the inhibition of DRP1-mediated mitochondrial dynamic remodeling and ROS production.These findings may assist the development of novel therapeutic strategies for patients with DN.

View Article: PubMed Central - PubMed

Affiliation: Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai, 200233, China.

ABSTRACT
The overproduction of mitochondrial reactive oxygen species (ROS) plays a key role in the pathogenesis of diabetic nephropathy (DN). However, the underlying molecular mechanism remains unclear. Our aim was to investigate the role of PGC-1α in the pathogenesis of DN. Rat glomerular mesangial cells (RMCs) were incubated in normal or high glucose medium with or without the PGC-1α-overexpressing plasmid (pcDNA3-PGC-1α) for 48 h. In the diabetic rats, decreased PGC-1α expression was associated with increased mitochondrial ROS generation in the renal cortex, increased proteinuria, glomerular hypertrophy, and higher glomerular 8-OHdG (a biomarker for oxidative stress). In vitro, hyperglycemia induced the downregulation of PGC-1α, which led to increased DRP1 expression, increased mitochondrial fragmentation and damaged network structure. This was associated with an increase in ROS generation and mesangial cell hypertrophy. These pathological changes were reversed in vitro by the transfection of pcDNA3-PGC-1α. These data suggest that PGC-1α may protect DN via the inhibition of DRP1-mediated mitochondrial dynamic remodeling and ROS production. These findings may assist the development of novel therapeutic strategies for patients with DN.

No MeSH data available.


Related in: MedlinePlus

Inhibitory action of PGC-1α on mitochondrial fragmentation occurs via the downregulation of DRP1.A: Western blotting analysis of DRP-1 and PGC-1α expression in the NG, NG+shRNA-con, NG+PGC-1α shRNA, HG, HG+pcDNA3, and HG+pcDNA3-PGC-1α groups. Equal protein loading was confirmed with tubulin antibody staining. Data are presented as the mean ± SD values for three cells per group, and experiments were repeated independently at least three times (*P < 0.05 vs. NG, # P < 0.05 vs. HG). B: Mesangial cells were transfected with DRP1 short hairpin RNA (shRNA) for 48 h, and DRP1 protein expression was detected by western blotting. DRP1 expression was inhibited (~50% reduction) by DRP1 shRNA. C-F: ROS production, mitochondrial morphology changes, and computer-assisted morphometric analyses of mitochondrial morphology in RMCs exposed to normal glucose (NG), NG incubated with DRP1 protein and high glucose (HG) conditions, RMCs transfected with DRP1 shRNA to silence the expression of DRP1 under HG conditions (HG+DRP1-shRNA), and RMCs transfected with pcDNA-PGC-1α to overexpress PGC-1α and exogenous DPR1 protein under HG conditions (HG+pcDNA3-PGC-1α+DRP1). ***P < 0.001,** P < 0.01 versus NG, ## P < 0.01, # P < 0.05 versus HG.
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pone.0125176.g004: Inhibitory action of PGC-1α on mitochondrial fragmentation occurs via the downregulation of DRP1.A: Western blotting analysis of DRP-1 and PGC-1α expression in the NG, NG+shRNA-con, NG+PGC-1α shRNA, HG, HG+pcDNA3, and HG+pcDNA3-PGC-1α groups. Equal protein loading was confirmed with tubulin antibody staining. Data are presented as the mean ± SD values for three cells per group, and experiments were repeated independently at least three times (*P < 0.05 vs. NG, # P < 0.05 vs. HG). B: Mesangial cells were transfected with DRP1 short hairpin RNA (shRNA) for 48 h, and DRP1 protein expression was detected by western blotting. DRP1 expression was inhibited (~50% reduction) by DRP1 shRNA. C-F: ROS production, mitochondrial morphology changes, and computer-assisted morphometric analyses of mitochondrial morphology in RMCs exposed to normal glucose (NG), NG incubated with DRP1 protein and high glucose (HG) conditions, RMCs transfected with DRP1 shRNA to silence the expression of DRP1 under HG conditions (HG+DRP1-shRNA), and RMCs transfected with pcDNA-PGC-1α to overexpress PGC-1α and exogenous DPR1 protein under HG conditions (HG+pcDNA3-PGC-1α+DRP1). ***P < 0.001,** P < 0.01 versus NG, ## P < 0.01, # P < 0.05 versus HG.

Mentions: DRP1 expression has been reported to be associated with mitochondrial fragmentation. To investigate whether DRP1 plays a role in PGC-1α-induced mitochondrial fragmentation, we measured the protein expression of DRP1 and PGC-1α in RMCs grown in NG and HG medium, and RMCs transfected with PGC-1α-shRNA and its control plasmid (shRNA-con) grown in NG medium or pcDNA-PGC-1α and its control plasmid(pcDNA3) grown in HG medium (Fig 4A). The protein expression of DRP1 was significantly higher in HG than in NG conditions, while there was no difference between the shRNA-con group grown in NG medium and the NG group, similar results were observed between RMCs transfected with PGC-1α-shRNA in NG medium and RMCs in HG medium. In addition, our results indicated that the upregulation of DRP1 induced by hyperglycemia could be inhibited by overexpression of PGC-1α.


Protective role of PGC-1α in diabetic nephropathy is associated with the inhibition of ROS through mitochondrial dynamic remodeling.

Guo K, Lu J, Huang Y, Wu M, Zhang L, Yu H, Zhang M, Bao Y, He JC, Chen H, Jia W - PLoS ONE (2015)

Inhibitory action of PGC-1α on mitochondrial fragmentation occurs via the downregulation of DRP1.A: Western blotting analysis of DRP-1 and PGC-1α expression in the NG, NG+shRNA-con, NG+PGC-1α shRNA, HG, HG+pcDNA3, and HG+pcDNA3-PGC-1α groups. Equal protein loading was confirmed with tubulin antibody staining. Data are presented as the mean ± SD values for three cells per group, and experiments were repeated independently at least three times (*P < 0.05 vs. NG, # P < 0.05 vs. HG). B: Mesangial cells were transfected with DRP1 short hairpin RNA (shRNA) for 48 h, and DRP1 protein expression was detected by western blotting. DRP1 expression was inhibited (~50% reduction) by DRP1 shRNA. C-F: ROS production, mitochondrial morphology changes, and computer-assisted morphometric analyses of mitochondrial morphology in RMCs exposed to normal glucose (NG), NG incubated with DRP1 protein and high glucose (HG) conditions, RMCs transfected with DRP1 shRNA to silence the expression of DRP1 under HG conditions (HG+DRP1-shRNA), and RMCs transfected with pcDNA-PGC-1α to overexpress PGC-1α and exogenous DPR1 protein under HG conditions (HG+pcDNA3-PGC-1α+DRP1). ***P < 0.001,** P < 0.01 versus NG, ## P < 0.01, # P < 0.05 versus HG.
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Related In: Results  -  Collection

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pone.0125176.g004: Inhibitory action of PGC-1α on mitochondrial fragmentation occurs via the downregulation of DRP1.A: Western blotting analysis of DRP-1 and PGC-1α expression in the NG, NG+shRNA-con, NG+PGC-1α shRNA, HG, HG+pcDNA3, and HG+pcDNA3-PGC-1α groups. Equal protein loading was confirmed with tubulin antibody staining. Data are presented as the mean ± SD values for three cells per group, and experiments were repeated independently at least three times (*P < 0.05 vs. NG, # P < 0.05 vs. HG). B: Mesangial cells were transfected with DRP1 short hairpin RNA (shRNA) for 48 h, and DRP1 protein expression was detected by western blotting. DRP1 expression was inhibited (~50% reduction) by DRP1 shRNA. C-F: ROS production, mitochondrial morphology changes, and computer-assisted morphometric analyses of mitochondrial morphology in RMCs exposed to normal glucose (NG), NG incubated with DRP1 protein and high glucose (HG) conditions, RMCs transfected with DRP1 shRNA to silence the expression of DRP1 under HG conditions (HG+DRP1-shRNA), and RMCs transfected with pcDNA-PGC-1α to overexpress PGC-1α and exogenous DPR1 protein under HG conditions (HG+pcDNA3-PGC-1α+DRP1). ***P < 0.001,** P < 0.01 versus NG, ## P < 0.01, # P < 0.05 versus HG.
Mentions: DRP1 expression has been reported to be associated with mitochondrial fragmentation. To investigate whether DRP1 plays a role in PGC-1α-induced mitochondrial fragmentation, we measured the protein expression of DRP1 and PGC-1α in RMCs grown in NG and HG medium, and RMCs transfected with PGC-1α-shRNA and its control plasmid (shRNA-con) grown in NG medium or pcDNA-PGC-1α and its control plasmid(pcDNA3) grown in HG medium (Fig 4A). The protein expression of DRP1 was significantly higher in HG than in NG conditions, while there was no difference between the shRNA-con group grown in NG medium and the NG group, similar results were observed between RMCs transfected with PGC-1α-shRNA in NG medium and RMCs in HG medium. In addition, our results indicated that the upregulation of DRP1 induced by hyperglycemia could be inhibited by overexpression of PGC-1α.

Bottom Line: This was associated with an increase in ROS generation and mesangial cell hypertrophy.These data suggest that PGC-1α may protect DN via the inhibition of DRP1-mediated mitochondrial dynamic remodeling and ROS production.These findings may assist the development of novel therapeutic strategies for patients with DN.

View Article: PubMed Central - PubMed

Affiliation: Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai, 200233, China.

ABSTRACT
The overproduction of mitochondrial reactive oxygen species (ROS) plays a key role in the pathogenesis of diabetic nephropathy (DN). However, the underlying molecular mechanism remains unclear. Our aim was to investigate the role of PGC-1α in the pathogenesis of DN. Rat glomerular mesangial cells (RMCs) were incubated in normal or high glucose medium with or without the PGC-1α-overexpressing plasmid (pcDNA3-PGC-1α) for 48 h. In the diabetic rats, decreased PGC-1α expression was associated with increased mitochondrial ROS generation in the renal cortex, increased proteinuria, glomerular hypertrophy, and higher glomerular 8-OHdG (a biomarker for oxidative stress). In vitro, hyperglycemia induced the downregulation of PGC-1α, which led to increased DRP1 expression, increased mitochondrial fragmentation and damaged network structure. This was associated with an increase in ROS generation and mesangial cell hypertrophy. These pathological changes were reversed in vitro by the transfection of pcDNA3-PGC-1α. These data suggest that PGC-1α may protect DN via the inhibition of DRP1-mediated mitochondrial dynamic remodeling and ROS production. These findings may assist the development of novel therapeutic strategies for patients with DN.

No MeSH data available.


Related in: MedlinePlus