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You-Fei Guan

Publications and source records attributed to You-Fei Guan.

7 recordsLinked to original sources

[PPAR family and its relationship to metabolic syndrome].

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of ligand--activated transcription factors. Three PPAR isoforms , designated PPARalpha, -beta/delta, and -gamma, have been identified and attracted enormous attention due to the key role these receptors play in regulating adipogenesis, lipid metabolism, insulin sensitivity, inflammation and blood pressure. Growing evidence points to a causative relationship between PPAR activity and the metabolic syndrome, including insulin resistance, glucose intolerance or type II diabetes, obesity, dyslipidemia, hypertension, atherosclerosis, and albuminuria. Importantly, both PPARalpha activators such as fibric acid class of hypolipidemic drugs and PPARgamma agonists including antidiabetic thiazolidinediones (TZDs) have been proved to be effective for improving metabolic syndrome. All three PPAR isoforms appear to play important roles in the development of type II diabetes and diabetic nephropathy. Accumulating data has begun to emerge suggesting PPARs may serve as potential therapeutic targets for treating the metabolic syndrome and its related complications. Here we review the literature pertaining to the action, ligand selectivity and physiological role of PPARs. Particular emphasis is placed on their pathogenic roles in the metabolic syndrome and the therapeutic utility of PPAR modulators in the treatment of type II diabetes.

Diabetes Mellitus, Type 2↗

The glomerulosclerosis of aging in females: contribution of the proinflammatory mesangial cell phenotype to macrophage infiltration.

Age-associated renal changes may be an important cause of renal failure. We recently found that aged female B6 mice developed progressive glomerular lesions. This was associated with macrophage infiltration, a frequent finding in glomerulosclerosis. We used these mice as a model for studying the mechanisms of glomerular aging. We compared the gene expression profile of intact glomeruli from late postmenopausal (28-month-old) mice to that of intact glomeruli from premenopausal (5-month-old) mice. We found that inflammation-related genes, especially those expressed by activated macrophages, were up-regulated in the glomeruli of 28-month-old mice, a result correlating with the histological observation of glomerular macrophage infiltration. The mechanism for macrophage recruitment could have been stable phenotypic changes in mesangial cells because we found that mesangial cells isolated from 28-month-old mice expressed higher levels of RANTES and VCAM-1 than cells from 5-month-old mice. The elevated serum tumor necrosis factor (TNF)-alpha levels present in aged mice may contribute to increased RANTES and VCAM-1 expression in mesangial cells. Furthermore, cells from 28-month-old mice were more sensitive to TNF-alpha-induced RANTES and VCAM-1 up-regulation. The effect of TNF-alpha on RANTES expression was mediated by TNF receptor 1. Interestingly, mesangial cells isolated from 28-month-old mice had increased nuclear factor-kappaB transcriptional activity. Inhibition of nuclear factor-kappaB activity decreased baseline as well as TNF-alpha-induced RANTES and VCAM-1 expression in mesangial cells isolated from 28-month-old mice. Thus, phenotypic changes in mesangial cells may predispose them to inflammatory stimuli, such as TNF-alpha, which would contribute to glomerular macrophage infiltration and inflammatory lesions in aging.

Aging↗

[On the bile acid receptor FXR].

Farnesoid X receptor (FXR) was identified as a bile acid receptor for regulation of bile acid biosynthesis and cholesterol metabolism. FXR became a potential therapeutic target for lowering serum cholesterol and certain cardiovascular and liver diseases. In this review, the discovery of FXR, its roles in regulating bile acid and cholesterol metabolism and its application in cardiovascular disease will be summarized.

Animals↗