Recently, R. Palanivel et al. investigated the role that RhoA-mediated re-organization of the actin cytoskeleton has in adiponectin-regulated glucose uptake in cardiomyocytes. Adiponectin is a protein secreted by adipose tissue that modulates glucose and fatty acid metabolism. In concert with APPL1, an adiponectin receptor binding partner, adiponectin carries out these functions which are important in obesity and type 2 diabetes, two diseases that reduce cardiac energy metabolism. The authors found that adiponectin (both full-length and globular) elevates RhoA activity which correlates with increased actin polymerization and glucose uptake. Changes in the G-/F-actin ratio likely involve APPL1 as adiponectin increases colocalization of actin and APPL1. Inhibition of actin polymerization or RhoA signaling significantly reduces the adiponectin-mediated increase in glucose uptake. Thus, RhoA-mediated actin cytoskeleton remodeling is required for adiponectin-regulated glucose uptake in cardiomyocytes. Increased glucose uptake is cardioprotective in diabetes. A number of products by Cytoskeleton Inc. (“The Protein Experts”) were essential in this study, providing accurate and sensitive assays for quantifying levels of activated RhoA and changes in G- and F-actin levels or binding partners in cardiomyocytes under conditions of RhoA inhibition.
- RhoA G-LISA activation assay
- G-/F-actin In Vivo Assay Kit
- Anti-actin antibody
- Cell-permeable Rho inhibitor
These reagents are available in Europe through tebu-bio, who have also compiled useful selection tools:
Reference: Palanivel et al. 2014. Adiponectin stimulates Rho-mediated actin cytoskeleton remodeling and glucose uptake via APPL1 in primary cardiomyocytes. Metabolism. 63, 1363-1373.