Chemerin contributes to in vivo adipogenesis in a location-specific manner

Abstract

Since chemerin's identification as an adipokine, it has been associated with a number of human diseases including diabetes and obesity. However, the basic scientific foundation for these clinical determinations is still lacking. Fibroblastic mouse 3T3 cells are unable to develop lipid droplets if chemerin is not present. Thus, we hypothesized that an in vivo rat model chemerin knockout (KO; an advancement from the previously mentioned in vitro cultures) would have limited accumulation of lipid in adipocytes compared to their wild-type (WT) counterparts. Female WT/KO rats (Sprague Dawley background) were fed a low-fat diet starting at 8 weeks of age with weekly body weight and food consumption monitoring. At 25 weeks of age, adipose tissue depots were dissected and flash frozen for PCR analysis or fixed with paraformaldehyde for histology. Over the 17 weeks of experimentation, WT and KO animals did not have differences in total body weight or food consumption but KO animals had a significantly reduced amount of visceral fat compared to WT animals (via microCT at 8 and 25 weeks). Histology of retroperitoneal and mesenteric depots demonstrated a significant leftward shift in adipocyte size in the mesenteric but not the retroperitoneal depot of the KO compared to WT animals. Similarly, in the mesenteric fat of the KO rat, gene expression of adiponectin, fatty acid synthase, perilipin, and leptin were significantly reduced compared to mesenteric fat of WT animals and retroperitoneal fat of both WT and KO animals. Adiponectin was highlighted by a protein-protein interaction network as being important for the physiological effects of chemerin removal. These data are the first, to our knowledge, to demonstrate chemerin's adipokine potential in vivo and identify it as fat depot location-specific.

Male and Female Animals Respond Differently to High-Fat Diet and Regular Exercise Training in a Mouse Model of Hyperlipidemia

“…This is in line with the results of our qPCR analysis, revealing a significant increase in Rarres2 expression in the BAT of APOB-100 male animals. This gene encodes the adipokine chemerin, which is known to be involved in the regulation of adipogenesis and lipid accumulation [28,40]. It is reasonable to suppose that excessive lipid accumulation influences the normal function of BAT.…”

Transcriptomic profiling of adipose tissue inflammation, remodeling, and lipid metabolism in periparturient dairy cows (Bos taurus)

“…Histological analyses were performed using hematoxylin- and eosin-stained sections from paraformaldehyde fixed paraffin-embedded tissue. The area of adipocytes in 5 randomly selected fields per section was measured using the Adiposoft plugin (v. 1.15) for ImageJ Fiji (v 2.0.0), as described in [ 14 ].…”

Dietary Intervention, When Not Associated With Exercise, Upregulates Irisin/FNDC5 While Reducing Visceral Adiposity Markers in Obese Rats

“…The Adiposoft plug-in was equalized with a diameter between 25 and 200 microns according to the program calibration. For each condition, a sample of n = 5 was selected and 100 fat cells per animal were evaluated (Ferland et al, 2020).…”