NS-1: A novel partial peroxisome proliferator-activated receptor γ agonist to improve insulin sensitivity and metabolic profile

2012 ◽  
Vol 684 (1-3) ◽  
pp. 154-160 ◽  
Author(s):  
Sumit Chaudhary ◽  
Aakanksha Dube ◽  
Vishal Kothari ◽  
Narsingh Sachan ◽  
Chandrashekhar Devidas Upasani
2000 ◽  
Vol 275 (22) ◽  
pp. 16638-16642 ◽  
Author(s):  
Michèle Guerre-Millo ◽  
Philippe Gervois ◽  
Eric Raspé ◽  
Lise Madsen ◽  
Philippe Poulain ◽  
...  

PPAR Research ◽  
2009 ◽  
Vol 2009 ◽  
pp. 1-15 ◽  
Author(s):  
Weimin He

The nuclear hormone receptor peroxisome proliferator activated receptor gamma (PPAR) is an important transcription factor regulating adipocyte differentiation, lipid and glucose homeostasis, and insulin sensitivity. Numerous genetic mutations of PPAR have been identified and these mutations positively or negatively regulate insulin sensitivity. Among these, a relatively common polymorphism of PPAR, Pro12Ala of PPAR2, the isoform expressed only in adipose tissue has been shown to be associated with lower body mass index, enhanced insulin sensitivity, and resistance to the risk of type 2 diabetes in human subjects carrying this mutation. Subsequent studies in different ethnic populations, however, have revealed conflicting results, suggesting a complex interaction between the PPAR2 Pro12Ala polymorphism and environmental factors such as the ratio of dietary unsaturated fatty acids to saturated fatty acids and/or between the PPAR2 Pro12Ala polymorphism and genetic factors such as polymorphic mutations in other genes. In addition, this polymorphic mutation in PPAR2 is associated with other aspects of human diseases, including cancers, polycystic ovary syndrome, Alzheimer disease and aging. This review will highlight findings from recent studies.


Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Shailendra P Singh ◽  
Maayan Waldman ◽  
Joseph Schragenheim ◽  
Lars Bellner ◽  
Jian Cao ◽  
...  

Background/Objectives: Obesity is a risk factor in the development of type 2 diabetes mellitus (DM2), which is associated with increased morbidity and mortality, predominantly as a result of cardiovascular complications. Increased adiposity is a systemic condition characterized by increased oxidative stress (ROS), inflammation, inhibition of anti-oxidant genes such as HO-1 and increased degradation of epoxyeicosatrienoic acids (EETs). Hypothesis: We postulate that EETs increase peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) activity, which controls mitochondrial function, oxidative metabolism and may also increase antioxidants and HO-1 gene expression. Methods: C57/B16 mice were fed a high fat (HF) diet for 26 wks. The protocol comprised three groups: A) WT, B) HF control and C) HF-treated with EET agonist (EET-A). Renal and visceral fat tissues were harvested to measure signaling protein. Consumption was measured at 6 and 24 wks. Mice were used to assess insulin levels, insulin sensitivity, blood pressure and mitochondrial OXPHOS and mitochondrial biogenesis (Mfn1, 2 and Opa1), and oxygen consumption (VO 2 ). Results: Animals on a HF diet exhibited increased body weight, fat content, fasting blood glucose levels, systolic blood pressure (BP) and a significant reduction in VO 2 . Administration of EET-A to HF-fed mice decreased the RQ (VCO 2 /VO 2 ) ratio and normalized BP. The HF diet produced increased levels of the adipogenic markers MEST, aP2, C/EBPα and FAS. EET-A attenuated these perturbations through an increase in renal and adipose tissue PGC1α levels. The EET-mediated HO-1 induction increased mitochondrial function as measured by OXPHOS, MnSOD and thermogenic genes, TFAM, UCP1 and SIRT 1. EET-A also increased adiponectin levels, and insulin receptor phosphorylation IRP Tyr 972 and 1146 and normalized glucose levels. Conclusion: These data show that an EET agonist increased PGC-1α-HO-1 levels thereby providing metabolic protection and increased VO 2 consumption in HF-induced obesity in mice. This novel finding suggests that the EET-mediated PGC-1α activation is essential to increase HO-1 levels, mitochondrial biogenesis, and to decrease mitochondrial ROS and adiposity.


2014 ◽  
Vol 53 (2) ◽  
pp. 191-200 ◽  
Author(s):  
Xiaoting Jiang ◽  
Xin Ye ◽  
Wei Guo ◽  
Hongyun Lu ◽  
Zhanguo Gao

Peroxisome proliferator-activated receptor gamma (PPARγ) is a nuclear receptor whose activation is dependent on a ligand. PPARγ activation by exogenous ligands, such as thiazolidinediones (TZDs), is a strategy in the treatment of type 2 diabetes mellitus for the improvement of insulin sensitivity. In addition to a ligand, PPARγ function is also regulated by posttranslational modifications, such as phosphorylation, sumoylation, and ubiquitination. Herein, we report that the PPARγ protein is modified by acetylation, which induces the PPARγ function in the absence of an external ligand. We observed that histone deacetylase 3 (HDAC3) interacted with PPARγ to deacetylate the protein. In immunoprecipitation assays, the HDAC3 protein was associated with the PPARγ protein. Inhibition of HDAC3 using RNAi-mediated knockdown or HDAC3 inhibitor increased acetylation of the PPARγ protein. Furthermore, inhibition of HDAC3 enhanced the expression of PPARγ target genes such as adiponectin and aP2. The expression was associated with an increase in glucose uptake and insulin signaling in adipocytes. HDAC3 inhibition enhanced lipid accumulation during differentiation of adipocytes. PPARγ acetylation was also induced by pioglitazone and acetylation was required for PPARγ activation. In the absence of TZDs, the acetylation from HDAC3 inhibition was sufficient to induce the transcriptional activity of PPARγ. Treating diet-induced obesity mice with HDAC3 inhibitor or pioglitazone for 2 weeks significantly improved high-fat-diet-induced insulin resistance. Our results indicate that acetylation of PPARγ is a ligand-independent mechanism of PPARγ activation. HDAC3 inhibitor is a potential PPARγ activator for the improvement of insulin sensitivity.


2010 ◽  
Vol 35 (2) ◽  
pp. 151-162 ◽  
Author(s):  
Scott P. Naples ◽  
Sarah J. Borengasser ◽  
R. Scott. Rector ◽  
Grace M. Uptergrove ◽  
E. Matthew Morris ◽  
...  

Rats selected artificially to be low-capacity runners (LCR) possess a metabolic syndrome phenotype that is worsened by a high-fat diet (HFD), whereas rats selected to be high-capacity runners (HCR) are protected against HFD-induced obesity and insulin resistance. This study examined whether protection against, or susceptibility to, HFD-induced insulin resistance in the HCR–LCR strains is associated with contrasting metabolic adaptations in skeletal muscle. HCR and LCR rats (generation 20; n = 5–6; maximum running distance ∼1800 m vs. ∼350 m, respectively (p < 0.0001)) were divided into HFD (71.6% energy from fat) or normal chow (NC) (16.7% energy from fat) groups for 7 weeks (from 24 to 31 weeks of age). Skeletal muscle (red gastrocnemius) mitochondrial-fatty acid oxidation (FAO), mitochondrial-enzyme activity, mitochondrial-morphology, peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), and peroxisome proliferator-activated receptor δ (PPARδ) expression and insulin sensitivity (intraperitoneal glucose tolerance tests) were measured. The HFD caused increased adiposity and reduced insulin sensitivity only in the LCR and not the HCR strain. Isolated mitochondria from the HCR skeletal muscle displayed a 2-fold-higher rate of FAO on NC, but both groups increased FAO following HFD. PGC-1α mRNA expression and superoxide dismutase activity were significantly reduced with the HFD in the LCR rats, but not in the HCR rats. PPARδ expression did not differ between strains or dietary conditions. These results do not provide a clear connection between protection of insulin sensitivity and HFD-induced adaptive changes in mitochondrial function or transcriptional responses but do not dismiss the possibility that elevated mitochondrial FAO in the HCR may play a protective role.


2009 ◽  
Vol 296 (5) ◽  
pp. E1120-E1132 ◽  
Author(s):  
Christelle Veyrat-Durebex ◽  
Xavier Montet ◽  
Manlio Vinciguerra ◽  
Asllan Gjinovci ◽  
Paolo Meda ◽  
...  

The inbred Lou/C rat, originating from the Wistar strain, has been described as a model of resistance to diet-induced obesity, but little is known about its metabolism. Since this knowledge could provide some clues about the etiology of obesity/insulin resistance, this study aimed at characterizing glucose and lipid metabolism in Lou/C vs. Wistar rats. This was achieved by performing glucose and insulin tolerance tests, euglycemic hyperinsulinemic clamps, and characterization of intracellular insulin signaling in skeletal muscle. Substrate-induced insulin secretion was evaluated using perfused pancreas and isolated islets. Finally, body fat composition and the expression of various factors involved in lipid metabolism were determined. Body weight and caloric intake were lower in Lou/C than in Wistar rats, whereas food efficiency was similar. Improved glucose tolerance of Lou/C rats was not related to increased insulin output but was related to improved insulin sensitivity/responsiveness in the liver and in skeletal muscles. In the latter tissue, this was accompanied by improved insulin signaling, as suggested by higher activation of the insulin receptor and of the Akt/protein kinase B pathway. Fat deposition was markedly lower in Lou/C than in Wistar rats, especially in visceral adipose tissue. In the inguinal adipose depot, expression of uncoupling protein-1 was detected in Lou/C but not in Wistar rats, in keeping with a higher expression of peroxisome proliferator-activated receptor-γ coactivator-1 in these animals. The Lou/C rat is a valuable model of spontaneous food restriction with associated improved insulin sensitivity. Independently from its reduced caloric intake, it also exhibits a preferential channeling of nutrients toward utilization rather than storage.


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