Gene expression profile evaluation of integrins in 3T3-L1 cells differentiated to adipocyte, insulin resistant and hypertrophied cells

Abstract Integrins are cell attachment receptors that function in the communication between the intracellular and extracellular compartments. Integrins and extra cellular matrix (ECM) collaborate to regulate gene expression by extracellular signal-regulated kinases (ERKs). Integrins as regulators, have critical role in ECM remodeling. Fibrosis is the hallmark of obesity and insulin resistance originated by aberrant ECM remodeling. Therefore deciphering integrins' expression profile in cells at different conditions is worthy. The aim of this study is evaluation of integrins' gene expression profile changes in mouse 3T3-L1 preadipocytes, adipocytes, insulin resistant and hypertrophic adipocytes. For this purpose, we differentiated mouse 3T3-L1 preadipocytes to adipocytes, insulin resistant and hypertrophied adipocytes and assayed integrinsʼ gene expression in four conditions by real time-PCR. Also the proteins expression changes of ERK and collagen VI assayed by Western blotting. Data analysis has shown that integrins' gene expression changes throughout adipocyte differentiation and pathological processes. The expressions of many integrins genes were significantly up- or down-regulated by >1.5-fold during differentiation, insulin resistant, and hypertrophic adipocytes. In addition to changes in the type of integrin, the integrins expression levels were different. Integrins, on the whole were more expressed in pathological processes relative to normal adipocytes. Also, phosphorylation of ERK 1,2 was increased >1.5-fold in differentiated, insulin resistant and hypertrophied adipocytes versus preadipocytes. Collagen VI only increased 2-fold in hypertrophied adipocytes. Examination of the total integrin gene family expression during adipocyte differentiation and pathological processes, leads to the identification of differential integrin gene expression. These results suggest that the type of integrin may not only play a role in adipocyte differentiation but also in pathological processes which may associate to increased ERK pathway activity in these conditions.