Chromium acetate stimulates adipogenesis through regulation of gene expression and phosphorylation of adenosine monophosphate-activated protein kinase in bovine intramuscular or subcutaneous adipocytes

Abstract

Objective: We hypothesized that Cr source can alter adipogenic-related transcriptional regulations and cell signaling. Therefore, the objective of the study was to evaluate the biological effects of chromium acetate (CrAc) on bovine intramuscular (IM) and subcutaneous (SC) adipose cells.Methods: Bovine preadipocytes isolated from two different adipose tissue depots; IM and SC were used to evaluate the effect of CrAc treatment during differentiation on adipogenic gene expression. Adipocytes were incubated with various doses of CrAc: 0 (differentiation media only, control), 0.1, 1, and 10 μM. Cells were harvested and then analyzed by real-time quantitative polymerase chain reaction in order to measure the quantity of adenosine monophosphate-activated protein kinase-α (<i>AMPK-α</i>), CCAAT enhancer binding protein-β (<i>C/EBPβ</i>), G protein-coupled receptor 41 (<i>GPR41</i>), <i>GPR43</i>, peroxisome proliferator-activated receptor-γ (<i>PPARγ</i>), and stearoyl CoA desaturase (<i>SCD</i>) mRNA relative to ribosomal protein subunit 9 (<i>RPS9</i>). The ratio of phosphorylated-AMPK (pAMPK) to AMPK was determined using a western blot technique in order to determine changing concentration.Results: The high dose (10 μM) of CrAc increased <i>C/EBPβ</i>, in both IM (p = 0.02) and SC (p = 0.02). Expression of <i>PPARγ</i> was upregulated by 10 μM of CrAc in IM but not in SC. Expression of <i>SCD</i> was also increased in both IM and SC with 10 μM of CrAc treatment. Addition of CrAc did not alter gene expression of glucose transporter 4, <i>GPR41</i>, or <i>GPR43</i> in both IM and SC adipocytes. Addition of CrAc, resulted in a decreased pAMPKα to AMPKα ration (p<0.01) in IM.Conclusion: These data may indicate that Cr source may influence lipid filling in IM adipocytes via inhibitory action of AMPK phosphorylation and upregulating expression of adipogenic genes.