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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

PGC-1α inhibited hyperglycemia-induced elevation of ROS production as well as mitochondrial fragmentation.A: Mesangial cells were transfected with PGC-1α short hairpin RNA (shRNA) for 48 h, and PGC-1α protein expression was detected by western blotting. PGC-1α expression was inhibited (~66% reduction) by PGC-1α shRNA. B: PGC-1α expression in transfected mesangial cells. Mesangial cells were transfected with the pcDNA3-PGC-1α (PGC-1α expression) plasmid or empty vector (pcDNA3), with untreated cells used as the control. Expression levels of PGC-1α in the indicated transfectants were analyzed by Western blotting. (C-F) ROS production, mitochondrial morphology changes, and computer-assisted morphometric analyses of mitochondrial morphology in RMCs exposed to normal glucose (NG) and high glucose (HG) conditions, RMCs transfected with PGC-1α shRNA plasmid (NG + PGC-1α shRNA) and shRNA control plasmid (NG+shRNA-con) and exposed to NG conditions, RMCs transfected with pcDNA-PGC-1α plasmid (HG + pcDNA3-PGC-1α) and empty plasmid pcDNA3 (HG + pcDNA3) and exposed to HG conditions, RMCs transfected with PGC-1α shRNA plasmid and DRP1-shRNA plasmid (NG + PGC-1α shRNA+DRP1-shRNA). ***P < 0.001, ** P < 0.01 versus NG, ## P < 0.01, # P < 0.05 versus HG. Scale bar: 10 μm.
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pone.0125176.g003: PGC-1α inhibited hyperglycemia-induced elevation of ROS production as well as mitochondrial fragmentation.A: Mesangial cells were transfected with PGC-1α short hairpin RNA (shRNA) for 48 h, and PGC-1α protein expression was detected by western blotting. PGC-1α expression was inhibited (~66% reduction) by PGC-1α shRNA. B: PGC-1α expression in transfected mesangial cells. Mesangial cells were transfected with the pcDNA3-PGC-1α (PGC-1α expression) plasmid or empty vector (pcDNA3), with untreated cells used as the control. Expression levels of PGC-1α in the indicated transfectants were analyzed by Western blotting. (C-F) ROS production, mitochondrial morphology changes, and computer-assisted morphometric analyses of mitochondrial morphology in RMCs exposed to normal glucose (NG) and high glucose (HG) conditions, RMCs transfected with PGC-1α shRNA plasmid (NG + PGC-1α shRNA) and shRNA control plasmid (NG+shRNA-con) and exposed to NG conditions, RMCs transfected with pcDNA-PGC-1α plasmid (HG + pcDNA3-PGC-1α) and empty plasmid pcDNA3 (HG + pcDNA3) and exposed to HG conditions, RMCs transfected with PGC-1α shRNA plasmid and DRP1-shRNA plasmid (NG + PGC-1α shRNA+DRP1-shRNA). ***P < 0.001, ** P < 0.01 versus NG, ## P < 0.01, # P < 0.05 versus HG. Scale bar: 10 μm.

Mentions: To clarify the role of PGC-1α in the regulation of mitochondrial ROS, we first transfected RMCs with PGC-1α shRNA plasmid, or pcDNA3-PGC-1α plasmid to silence or overexpress the expression of PGC-1α (Fig 3A and 3B). As shown in Fig 3C, cells that were transfected with PGC-1α shRNA plasmid (incubated in NG medium) had significantly increased levels of ROS that were comparable to those cells under high glucose conditions (P < 0.01). Similarly, the level of mitochondrial fragmentation in RMCs transfected with PGC-1α shRNA incubated in normal glucose is comparable to that under high glucose conditions (Fig 3D and 3E). In addition, the average FF and AR values showed similar changes (Fig 3F). There were no changes in the RMCs transfected with the shRNA-con plasmid (incubated in NG medium) and in the RMCs transfected with pcDNA3 plasmid (incubated with HG medium). On the contrary, the overexpression of PGC-1α significantly decreased levels of hyperglycemia-induced mitochondrial fragmentation and subsequent ROS production (Fig 3C–3E).


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)

PGC-1α inhibited hyperglycemia-induced elevation of ROS production as well as mitochondrial fragmentation.A: Mesangial cells were transfected with PGC-1α short hairpin RNA (shRNA) for 48 h, and PGC-1α protein expression was detected by western blotting. PGC-1α expression was inhibited (~66% reduction) by PGC-1α shRNA. B: PGC-1α expression in transfected mesangial cells. Mesangial cells were transfected with the pcDNA3-PGC-1α (PGC-1α expression) plasmid or empty vector (pcDNA3), with untreated cells used as the control. Expression levels of PGC-1α in the indicated transfectants were analyzed by Western blotting. (C-F) ROS production, mitochondrial morphology changes, and computer-assisted morphometric analyses of mitochondrial morphology in RMCs exposed to normal glucose (NG) and high glucose (HG) conditions, RMCs transfected with PGC-1α shRNA plasmid (NG + PGC-1α shRNA) and shRNA control plasmid (NG+shRNA-con) and exposed to NG conditions, RMCs transfected with pcDNA-PGC-1α plasmid (HG + pcDNA3-PGC-1α) and empty plasmid pcDNA3 (HG + pcDNA3) and exposed to HG conditions, RMCs transfected with PGC-1α shRNA plasmid and DRP1-shRNA plasmid (NG + PGC-1α shRNA+DRP1-shRNA). ***P < 0.001, ** P < 0.01 versus NG, ## P < 0.01, # P < 0.05 versus HG. Scale bar: 10 μm.
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Related In: Results  -  Collection

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pone.0125176.g003: PGC-1α inhibited hyperglycemia-induced elevation of ROS production as well as mitochondrial fragmentation.A: Mesangial cells were transfected with PGC-1α short hairpin RNA (shRNA) for 48 h, and PGC-1α protein expression was detected by western blotting. PGC-1α expression was inhibited (~66% reduction) by PGC-1α shRNA. B: PGC-1α expression in transfected mesangial cells. Mesangial cells were transfected with the pcDNA3-PGC-1α (PGC-1α expression) plasmid or empty vector (pcDNA3), with untreated cells used as the control. Expression levels of PGC-1α in the indicated transfectants were analyzed by Western blotting. (C-F) ROS production, mitochondrial morphology changes, and computer-assisted morphometric analyses of mitochondrial morphology in RMCs exposed to normal glucose (NG) and high glucose (HG) conditions, RMCs transfected with PGC-1α shRNA plasmid (NG + PGC-1α shRNA) and shRNA control plasmid (NG+shRNA-con) and exposed to NG conditions, RMCs transfected with pcDNA-PGC-1α plasmid (HG + pcDNA3-PGC-1α) and empty plasmid pcDNA3 (HG + pcDNA3) and exposed to HG conditions, RMCs transfected with PGC-1α shRNA plasmid and DRP1-shRNA plasmid (NG + PGC-1α shRNA+DRP1-shRNA). ***P < 0.001, ** P < 0.01 versus NG, ## P < 0.01, # P < 0.05 versus HG. Scale bar: 10 μm.
Mentions: To clarify the role of PGC-1α in the regulation of mitochondrial ROS, we first transfected RMCs with PGC-1α shRNA plasmid, or pcDNA3-PGC-1α plasmid to silence or overexpress the expression of PGC-1α (Fig 3A and 3B). As shown in Fig 3C, cells that were transfected with PGC-1α shRNA plasmid (incubated in NG medium) had significantly increased levels of ROS that were comparable to those cells under high glucose conditions (P < 0.01). Similarly, the level of mitochondrial fragmentation in RMCs transfected with PGC-1α shRNA incubated in normal glucose is comparable to that under high glucose conditions (Fig 3D and 3E). In addition, the average FF and AR values showed similar changes (Fig 3F). There were no changes in the RMCs transfected with the shRNA-con plasmid (incubated in NG medium) and in the RMCs transfected with pcDNA3 plasmid (incubated with HG medium). On the contrary, the overexpression of PGC-1α significantly decreased levels of hyperglycemia-induced mitochondrial fragmentation and subsequent ROS production (Fig 3C–3E).

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