TZDs reduce mitochondrial ROS production and enhance mitochondrial biogenesis
ABSTRACT Although it has been reported that thiazolidinediones (TZDs) may reduce cardiovascular events in type 2 diabetic patients, its precise mechanism is unclear. We previously demonstrated that hyperglycemia-induced production of reactive oxygen species from mitochondria (mtROS) contributed to the development of diabetic complications, and metformin normalized mt ROS production by induction of MnSOD and promotion of mitochondrial biogenesis by activating the PGC-1alpha pathway. In this study, we examined whether TZDs could inhibit hyperglycemia-induced mtROS production by activating the PGC-1alpha pathway. We revealed that pioglitazone and ciglitazone attenuated hyperglycemia-induced ROS production in human umbilical vein endothelial cells (HUVECs). Both TZDs increased the expression of NRF-1, TFAM and MnSOD mRNA. Moreover, pioglitazone increased mtDNA and mitochondrial density. These results suggest that TZDs normalize hyperglycemia-induced mtROS production by induction of MnSOD and promotion of mitochondrial biogenesis by activating PGC-1alpha. This phenomenon could contribute to the prevention of diabetic vascular complications.
- SourceAvailable from: Xiaoqiang Tang
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- "Metformin, which activates AMPK, has been shown to inhibit mPTP opening and endothelial cell apoptosis and to prevent endothelial dysfunction in experimental models (Schulz et al., 2008) and to stimulate microvascular repair in acute lung injury (Jian et al., 2013). The thiazolidinediones, including pioglitazone, have been reported to activate PGC1-α, a downstream factor of AMPK and SIRT1, and enhance mitochondrial biogenesis in ECs (Fujisawa et al., 2009). Rapamycin, the inhibitor of mTOR, is evidenced to attenuate atherosclerosis (Waksman et al., 2003), hypertension and PAH (Morales et al., 2001; Nishimura et al., 2001). "
ABSTRACT: Mitochondria are perhaps the most sophisticated and dynamic responsive sensing systems in eukaryotic cells. The role of mitochondria goes beyond their capacity to create molecular fuel and includes the generation of reactive oxygen species, the regulation of calcium, and the activation of cell death. In endothelial cells, mitochondria have a profound impact on cellular function under both healthy and diseased conditions. In this review, we summarize the basic functions of mitochondria in endothelial cells and discuss the roles of mitochondria in endothelial dysfunction and vascular diseases, including atherosclerosis, diabetic vascular dysfunction, pulmonary artery hypertension, and hypertension. Finally, the potential therapeutic strategies to improve mitochondrial function in endothelial cells and vascular diseases are also discussed, with a focus on mitochondrial-targeted antioxidants and calorie restriction.Frontiers in Physiology 05/2014; 5:175. DOI:10.3389/fphys.2014.00175 · 3.50 Impact Factor
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- "The hypothesis that mitochondrial biogenesis might be a cell response contributing to the cytoprotective effects of PPAR agonists is also indicated by previous results. Thus, thiazolidinedione-induced mitochondrial biogenesis sustains cell survival of normal and malignant T cells (Jo et al., 2006; Yang et al., 2007a), preserves the integrity of human umbilical vein endothelial cells (Fujisawa et al., 2009) and could contribute to the neuroprotection exerted by pioglitazone and rosiglitazone (Strum et al., 2007; Miglio et al., 2009; Semple and Noble-Haeusslein, 2011). Interestingly, mitochondrial biogenesis has been proposed to mediate (at least in part) the protective effects exerted by different agents shared by the ability to induce PGC-1a expression. "
ABSTRACT: BACKGROUND AND PURPOSE Peroxisome proliferator-activated receptor (PPAR) agonists exert anti-albuminuric effects. However, the nephroprotective effects of these drugs remain to be fully understood. We have investigated whether gemfibrozil, GW0742 and pioglitazone protect human podocytes against nutrient deprivation (ND)-induced cell death and the role of mitochondrial biogenesis as a cytoprotective process. EXPERIMENTAL APPROACH Immortalized human podocytes were pre-treated with the PPAR agonists and exposed to ND (5 h) under normoxia, hypoxia or in the presence of pyruvate. Cell death was measured at the end of the ND and of the recovery phase (24 h). Mitochondrial mass, cytochrome c oxidase (COX) subunits 1 and 4 were measured as markers of mitochondrial cell content, while membrane potential as an index of mitochondrial function. PGC-1α, NRF1 and Tfam expression was studied, as crucial regulators of mitochondrial biogenesis. KEY RESULTS Cell pre-treatment with gemfibrozil, GW0742, or pioglitazone significantly decreased the ND-induced cell loss, necrosis and apoptosis. These effects were attenuated by hypoxia and potentiated by pyruvate. Pre-treatment with these drugs significantly increased mitochondrial cell content, while it did not affect mitochondrial function. In all these experiments pioglitazone exerted significantly larger effects than gemfibrozil or GW0742. CONCLUSIONS AND IMPLICATIONS Gemfibrozil, GW0742 and pioglitazone may exert direct protective effects on human podocytes. Mitochondrial biogenesis is a cell response to the PPAR agonists related to their cytoprotective activity. These results provide a mechanistic support to the clinical evidence indicating PPAR agonists as disease-modifying agents for glomerular diseases.British Journal of Pharmacology 05/2012; 167(3):641-53. DOI:10.1111/j.1476-5381.2012.02026.x · 4.99 Impact Factor
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ABSTRACT: Peroxisome proliferator-activated receptor (PPAR)gamma stimulation provides protection in several models of neurological disorders, but the mechanisms underlying these effects remain to be fully elucidated. Here we have studied whether two PPARgamma agonists, pioglitazone and rosiglitazone, prevent loss of differentiated SH-SY5Y cells transiently exposed to glucose deprivation (GD). Nanomolar drug concentrations prevented GD-induced cell loss in a concentration- and time-dependent manner. These effects were abolished by malonate, a reversible mitochondrial Complex II inhibitor, while significantly potentiated by pyruvate, thus suggesting that they are related to mitochondrial function. During cell pretreatment, PPARgamma agonists promoted biogenesis of functional mitochondria, as indicated by the up-regulation of PPARgamma coactivator (PGC)-1alpha, NRF1, TFAM, cytochrome c oxidase subunit (CO) I and CO IV, and the increased level of mtDNA, while did not significantly change mitochondrial membrane potential. In addition, the analysis of the concentration-response and time-course curves for the protective effects and the up-regulation of mitochondrial biogenesis markers suggests that mitochondrial biogenesis and cell loss prevention are related effects. In conclusion our data indicate that a prolonged PPARgamma stimulation, by repeated administration of nanomolar pioglitazone or rosiglitazone concentrations, decreases GD-induced loss of differentiated SH-SY5Y cells. In addition, they suggest that mitochondrial biogenesis may contribute to these effects.Neurochemistry International 06/2009; 55(7):496-504. DOI:10.1016/j.neuint.2009.05.001 · 2.65 Impact Factor