1.
Adipocyte Death and Chronic Inflammation in Obesity.
Kuroda, M, Sakaue, H
The journal of medical investigation : JMI. 2017;(3.4):193-196
Abstract
Cell death is closely linked to many diseases including cancer, neurodegenerative diseases, autoimmune diseases, and metabolic disorders. Increased adipocyte death has been reported during the development of obesity. Adipocyte death may be caused by excessive stress during obesity-related adipose tissue remodeling. Adipose tissue macrophages are key players in obesity-related inflammation and systemic insulin resistance. Accumulating evidence suggests that adipocyte death is involved in immune cell function and initiates inflammation through an interaction with macrophages; however, the precise mechanisms remain largely unknown. This review focuses on the contribution of dead cells (particularly dead adipocytes in adipose tissue) to the pathophysiological conditions associated with obesity. J. Med. Invest. 64: 193-196, August, 2017.
2.
Adipose tissue gene expression is differentially regulated with different rates of weight loss in overweight and obese humans.
Vink, RG, Roumans, NJ, Fazelzadeh, P, Tareen, SH, Boekschoten, MV, van Baak, MA, Mariman, EC
International journal of obesity (2005). 2017;(2):309-316
Abstract
BACKGROUND/OBJECTIVES Moderate weight loss (WL) can ameliorate adverse health effects associated with obesity, reflected by an improved adipose tissue (AT) gene expression profile. However, the effect of rate of WL on the AT transcriptome is unknown. We investigated the global AT gene expression profile before and after two different rates of WL that resulted in similar total WL, and after a subsequent weight stabilization period. SUBJECTS/METHODS In this randomized controlled trial, 25 male and 28 female individuals (body mass index (BMI): 28-35 kg m-2) followed either a low-calorie diet (LCD; 1250 kcal day-1) for 12 weeks or a very-low-calorie diet (VLCD; 500 kcal day-1) for 5 weeks (WL period) and a subsequent weight stable (WS) period of 4 weeks. The WL period and WS period together is termed dietary intervention (DI) period. Abdominal subcutaneous AT biopsies were collected for microarray analysis and gene expression changes were calculated for all three periods in the LCD group, VLCD group and between diets (ΔVLCD-ΔLCD). RESULTS WL was similar between groups during the WL period (LCD: -8.1±0.5 kg, VLCD -8.9±0.4 kg, difference P=0.25). Overall, more genes were significantly regulated and changes in gene expression appeared more pronounced in the VLCD group compared with the LCD group. Gene sets related to mitochondrial function, adipogenesis and immunity/inflammation were more strongly upregulated on a VLCD compared with a LCD during the DI period (positive ΔVLCD-ΔLCD). Neuronal and olfactory-related gene sets were decreased during the WL period and DI period in the VLCD group. CONCLUSIONS The rate of WL (LCD vs VLCD), with similar total WL, strongly regulates AT gene expression. Increased mitochondrial function, angiogenesis and adipogenesis on a VLCD compared with a LCD reflect potential beneficial diet-induced changes in AT, whereas differential neuronal and olfactory regulation suggest functions of these genes beyond the current paradigm.