Apoptosis, mastocytosis, and diminished adipocytokine gene expression accompany reduced epididymal fat mass in long-standing diet-induced obese mice

Lipids in Health and Disease

Research

George McNamara¹  Behzad Nayer²  Ali Nayer³  Mehmet M Altintas³  Luis M Ortega³  Jochen Reiser³  Patricia Zagallo³  Alvaro Puig³  Kevin B Johnson⁴  Maria A Rossetti⁴  Armando J Mendez⁴ 

[1] Analytical Imaging Core Facility, Diabetes Research Institute, and UM/Sylvester Comprehensive Cancer Center, University of Miami, Miami, FL, USA;College of Engineering, University of Miami, Coral Gables, FL, USA;Department of Medicine, Miller School of Medicine, University of Miami, Miami, FL, USA;Diabetes Research Institute and Division of Endocrinology, Diabetes and Metabolism, University of Miami, Miami, FL, USA;

关键词: Obesity;    adipose tissue;    inflammation;    mast cells;    macrophages;    crown-like structures;    apoptosis;    adipokines;   

DOI  :  10.1186/1476-511X-10-198

 received in 2011-10-16, accepted in 2011-11-03,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundObesity is characterized by increased cell death and inflammatory reactions in the adipose tissue. Here, we explored pathophysiological alterations taking place in the adipose tissue in long-standing obesity. In the epididymal fat of C57BL/6 mice fed a high-fat diet for 20 weeks, the prevalence and distribution of dead adipocytes (crown-like structures), mast cells (toluidine blue, mMCP6), macrophages (F4/80), and apoptotic cells (cleaved caspase-3) were measured. Moreover, gene and/or protein expression of several adipocytokines (leptin, adiponectin, TNF-α, IL-10, IL-6, MCP-1), F4/80, mMCP6, cleaved caspase-3 were determined.ResultsWe observed that the epididymal fat mass was lower in obese than in lean mice. In obese mice, the epididymal fat mass correlated inversely with body weight and liver mass. Dead adipocytes, mast cells, macrophages, and apoptotic cells were abundant in the epididymal fat of obese mice, especially in the rostral vs. caudal zone. Accordingly, mMCP6, F4/80, and cleaved caspase-3 gene and/or protein expression was increased. Conversely, adiponectin, leptin, IL-6, and MCP-1 gene expression levels were lower in the epididymal fat of obese than lean mice. Although TNF-α and IL-10 gene expression was higher in the epididymal fat of obese mice, their expression relative to F4/80 and mMCP6 expression were lower in the heavily infiltrated rostral than caudal zone.ConclusionsThis study demonstrates that in mice with long-standing obesity diminished gene expression of several adipocytokines accompany apoptosis and reduced mass of the epididymal fat. Our findings suggest that this is due to both increased prevalence of dead adipocytes and altered immune cell activity. Differential distribution of metabolically challenged adipocytes is indicative of the presence of biologically diverse zones within the epididymal fat.

【 授权许可】

Unknown   
© Altintas et al; licensee BioMed Central Ltd. 2011. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.