scholarly journals PPARγAgonist Rosiglitazone Suppresses Renal mPGES-1/PGE2 Pathway in db/db Mice

PPAR Research ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Ying Sun ◽  
Zhanjun Jia ◽  
Gang Liu ◽  
Li Zhou ◽  
Mi Liu ◽  
...  

Evidence had shown the detrimental effect of prostaglandin (PG) E2 in diabetic nephropathy (DN) of STZ-induced type-1 diabetes but its role in the development of DN of type-2 diabetes remains uncertain. The present study was undertaken to investigate the regulation of PGE2 synthetic pathway and the interaction between peroxisome proliferator-activated receptor (PPAR)γand PGE2 synthesis in the kidneys of db/db mice. Strikingly, urinary PGE2 was remarkably elevated in db/db mice paralleled with the increased protein expressions of COX-2 and mPGES-1. In contrast, the protein expressions of COX-1, mPGES-2, cPGES, and 15-hydroxyprostaglandin dehydrogenase (15-PGDH) were not altered. Following 1-week rosiglitazone (Rosi) therapy, urinary PGE2, but not other prostanoids, was reduced by 57% in parallel with significant reduction of mPGES-1 protein and EP4 mRNA expressions. By immunohistochemistry, mPGES-1 was significantly induced in the glomeruli of db/db mice, which was almost entirely abolished by Rosi. In line with the reduction of glomerular mPGES-1, the glomerular injury score showed a tendency of improvement after 1 week of Rosi therapy. Collectively, the present study demonstrated an inhibitory effect of PPARγactivation on renal mPGES-1/PGE2/EP4 pathway in type-2 diabetes and suggested that mPGES-1 may potentially serve as a therapeutic target for treating type-2 diabetes-associated DN.

2001 ◽  
Vol 86 (7) ◽  
pp. 3452-3452 ◽  
Author(s):  
Hiroyuki Koshiyama ◽  
Dai Shimono ◽  
Naomitsu Kuwamura ◽  
Jun Minamikawa ◽  
Yoshio Nakamura

There have been increasing evidences that thiazolidinediones, peroxisome proliferator-activated receptor γ (PPARγ) agonists, may have some antiatherogenic actions. We have previously reported that troglitazone has a potent inhibitory effect on common carotid arterial intima-media thickness (IMT) in subjects with type 2 diabetes. However, some studies suggested a possibility that PPARγ activators may have protoatherogenic actions, raising concern about their detrimental effects in diabetic subjects. In the present study, we investigated the effect of treatment with pioglitazone, another PPARγ agonist, on IMT in a total of 106 Japanese subjects with type 2 diabetes. Pioglitazone (30 mg daily) was administered for 6 months in 53 patients. Compared to control group (n = 53), the group given pioglitazone showed a significant decrease in IMT as early as 3 months after the administration. The decrease in IMT was also found after 6 months (IMT change: −0.084[SE 0.023] mm vs. control 0.022[SE 0.006] mm, P < 0.001), although the difference between those after 3 and 6 months did not reach any statistical significance. These findings indicate that thiazolidinediones cause an inhibition of early atherosclerotic process PPARγ activation.


2015 ◽  
Vol 165 (2) ◽  
pp. 336-345 ◽  
Author(s):  
Tomoko Terasawa ◽  
Yoshimasa Aso ◽  
Kyoko Omori ◽  
Maiko Fukushima ◽  
Atsushi Momobayashi ◽  
...  

2006 ◽  
Vol 92 (2) ◽  
pp. 386-395 ◽  
Author(s):  
Arya M. Sharma ◽  
Bart Staels

Abstract Context: Adipose tissue is a metabolically dynamic organ, serving as a buffer to control fatty acid flux and a regulator of endocrine function. In obese subjects, and those with type 2 diabetes or the metabolic syndrome, adipose tissue function is altered (i.e. adipocytes display morphological differences alongside aberrant endocrine and metabolic function and low-grade inflammation). Evidence Acquisition: Articles on the role of peroxisome proliferator-activated receptor γ (PPARγ) in adipose tissue of healthy individuals and those with obesity, metabolic syndrome, or type 2 diabetes were sourced using MEDLINE (1990–2006). Evidence Synthesis: Articles were assessed to provide a comprehensive overview of how PPARγ-activating ligands improve adipose tissue function, and how this links to improvements in insulin resistance and the progression to type 2 diabetes and atherosclerosis. Conclusions: PPARγ is highly expressed in adipose tissue, where its activation with thiazolidinediones alters fat topography and adipocyte phenotype and up-regulates genes involved in fatty acid metabolism and triglyceride storage. Furthermore, PPARγ activation is associated with potentially beneficial effects on the expression and secretion of a range of factors, including adiponectin, resistin, IL-6, TNFα, plasminogen activator inhibitor-1, monocyte chemoattractant protein-1, and angiotensinogen, as well as a reduction in plasma nonesterified fatty acid supply. The effects of PPARγ also extend to macrophages, where they suppress production of inflammatory mediators. As such, PPARγ activation appears to have a beneficial effect on the relationship between the macrophage and adipocyte that is distorted in obesity. Thus, PPARγ-activating ligands improve adipose tissue function and may have a role in preventing progression of insulin resistance to diabetes and endothelial dysfunction to atherosclerosis.


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