ROCK2 inhibition enhances the thermogenic program in white and brown fat tissue in mice

Abstract

The RhoA/ROCK‐mediated actin cytoskeleton dynamics have been implicated in adipogenesis. The two ROCK isoforms, ROCK1 and ROCK2, are highly homologous. The contribution of ROCK2 to adipogenesis in vivo has not been elucidated. The present study aimed at the in vivo and in vitro roles of ROCK2 in the regulation of adipogenesis and the development of obesity. We performed molecular, histological, and metabolic analyses in ROCK2+/− and ROCK2+/KD mouse models, the latter harboring an allele with a kinase‐dead (KD) mutation. Both ROCK2+/− and ROCK2+/KD mouse models showed a lean body mass phenotype during aging, associated with increased amounts of beige cells in subcutaneous white adipose tissue (sWAT) and increased thermogenic gene expression in all fat depots. ROCK2+/− mice on a high‐fat diet showed increased energy expenditure accompanying by reduced obesity, and improved insulin sensitivity. In vitro differentiated ROCK2+/− stromal‐vascular (SV) cells revealed increased beige adipogenesis associated with increased thermogenic gene expressions. Treatment with a selective ROCK2 inhibitor, KD025, to inhibit ROCK2 activity in differentiated SV cells reproduced the pro‐beige phenotype of ROCK2+/− SV cells. In conclusion, ROCK2 activity‐mediated actin cytoskeleton dynamics contribute to the inhibition of beige adipogenesis in WAT, and also promotes age‐related and diet‐induced fat mass gain and insulin resistance.

ROCK2-Specific Inhibitor KD025 Suppresses Adipocyte Differentiation by Inhibiting Casein Kinase 2

“…ROCK2 functions differently from ROCK1 in glucose metabolism in that ROCK2 directly interacts and phosphorylates IRS-1 in cells [ 5 ]. ROCK2-partially deleted (ROCK2 +/− ) mice show a lean body mass phenotype and improved insulin sensitivity during aging [ 46 ]. ROCK2 suppresses adipocyte differentiation in 3T3-L1 and hADSCs, whereas ROCK1 performs no special function [ 15 , 19 ].…”

Genome Profiling of H3k4me3 Histone Modification in Human Adipose Tissue during Obesity and Insulin Resistance

“…As examples of genes that could be H3K4me3 regulated with a role in obesity and IR: (1) CXCL14 is a chemokine that in mice has been shown to be released by brown adipocytes and that exerts a beneficial role in white adipose tissue causing increased of insulin sensitivity in obese mice [30]. Therefore, higher levels of this cytokine in Ob.LIR could be in part responsible for the low IR level shown compared to Ob.HIR; (2) ZBTB16, which has been proposed as a regulator of adipogenesis in epigenetic studies, has been shown to stimulate adipogenesis and induce brown-like adipocyte formation in bovine primary cells [31]; (3) another upregulated gene was ROCK2, an inhibitor of adipogenesis in 3T3L1 cells, while partial ROCK KO mice display a pronounced thermogenic rewiring of white AT, AT mass gain and an amelioration of IR [32,33]; (4) PLIN2, which is located in the droplet surface, can inhibit glucose uptake in several models including differentiated 3T3L1 cell lines [34,35]; therefore, the higher regulation of PLIN2 in Ob.HIR would also be in concordance; (5) CD36 is upregulated both in high IR states. Lack of CD36 in a Cd36-KO mouse model presented lower adiposity with alteration in leptin production and higher insulin sensitivity [36].…”

Rho Kinases in Embryonic Development and Stem Cell Research

“…Together, these genetic studies using ROCK1 -/and ROCK2 -/mice provide significant insights into the biological functions of ROCK1 and ROCK2 isoforms which appear to be largely redundant during development. (Wei et al 2020) (Fig. 2H).…”

“…Viewed in this way, KD knockin mutation may not be functionally identical to null mutation. Molecular analyses indicate that the KD mutation in each isoform inactivates kinase activity, but has no detectable changes in protein expression (Wei et al 2020 ) (Fig. 2 H).…”