The relationship of visfatin/pre-B-cell colony-enhancing factor/nicotinamide phosphoribosyltransferase in adipose tissue with inflammation, insulin resistance, and plasma lipids.
Visfatin/pre-B-cell colony-enhancing factor (PBEF)/nicotinamide phosphoribosyltransferase (Nampt) has been proposed as an insulin-mimicking adipocytokine predominantly secreted from visceral adipose tissue (VAT) and correlated with obesity. However, recent evidence challenged this proposal and instead suggested visfatin/PBEF/Nampt as a proinflammatory cytokine. The study aimed to examine whether visfatin/PBEF/Nampt was predominantly expressed in VAT and was correlated with obesity. The relationship of visfatin/PBEF/Nampt gene expression in adipose tissues with proinflammatory gene expression and metabolic phenotypes was also examined. The relative messenger RNA (mRNA) levels of visfatin/PBEF/Nampt, macrophage-specific marker CD68, and proinflammatory genes were measured in paired abdominal VAT and subcutaneous adipose tissues (SAT) and from 53 nondiabetic adults using quantitative real-time polymerase chain reaction. Fasting glucose, insulin, triglyceride, cholesterol, and uric acid levels were measured; and systemic insulin sensitivity was quantified with modified insulin suppression tests. There was no difference in visfatin/PBEF/Nampt mRNA levels between VAT and SAT, and neither was associated with measures of obesity. Visfatin/PBEF/Nampt mRNA levels were strongly correlated with proinflammatory gene expression including CD68 and tumor necrosis factor-alpha gene in both VAT and SAT. The VAT and SAT visfatin/PBEF/Nampt mRNA expressions were positively correlated with steady-state plasma glucose concentrations measured with modified insulin suppression tests, a direct measurement of systemic insulin resistance (r = 0.42, P = .03 and r = 0.44, P = .03, respectively). The VAT visfatin/PBEF/Nampt mRNA expression was also positively correlated with fasting triglyceride (r = 0.42, P = .002) and total cholesterol levels (r = 0.37, P = .009). Visfatin/PBEF/Nampt is not predominantly secreted from VAT and is not correlated with obesity. Our findings suggest that visfatin/PBEF/Nampt is a proinflammatory marker of adipose tissue associated with systemic insulin resistance and hyperlipidemia.
Chang
Yi-Cheng
YC
Department of Internal Medicine, National Taiwan University Hospital Yun-Lin Branch, Yunlin 640, Taiwan.
Chang
Tien-Jyun
TJ
Lee
Wei-Jei
WJ
Chuang
Lee-Ming
LM
D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000378:metabolism*; D007333:Insulin Resistance; D008055:Lipids / Q000097:blood*; D008297:Male; D008875:Middle Aged; D054409:Nicotinamide Phosphoribosyltransferase / Q000378:metabolism*; D016133:Polymerase Chain Reaction
D016207:Cytokines; D008055:Lipids; D054409:Nicotinamide Phosphoribosyltransferase; C085455:nicotinamide phosphoribosyltransferase, human