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

• Published in: Molecules (Basel, Switzerland) Switzerland), 2021-08, Vol.26 (16), p.4747
• Main Authors: Tran, Nhu Nguyen Quynh, Chun, Kwang-Hoon
• Format: Article
• Language: English
• Subjects: 3T3-L1 Cells; adipocyte differentiation; Adipocytes; Adipocytes - cytology; Adipocytes - drug effects; Animals; belumosudil; Binding; Binding sites; Bioavailability; Casein; casein kinase; Casein kinase II; Casein Kinase II - antagonists & inhibitors; Cell differentiation; Cell Differentiation - drug effects; CK2; Cross-reactivity; Differentiation; Disease; Droplets; Gene expression; Gene Expression Regulation - drug effects; Heterocyclic Compounds, 4 or More Rings - pharmacology; KD025; Kinases; Lipids; Mice; mRNA; Peroxisome proliferator-activated receptors; Protein Kinase Inhibitors - pharmacology; Proteins; rho-Associated Kinases - antagonists & inhibitors; ROCK2; Rocks; Stem cells
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules26164747

KD025, a ROCK2 isoform-specific inhibitor, has an anti-adipogenic activity which is not mediated by ROCK2 inhibition. To identify the target, we searched binding targets of KD025 by using the KINOMEscan screening platform, and we identified casein kinase 2 (CK2) as a novel target. KD025 showed comparable binding affinity to CK2α ( = 128 nM). By contrast, CK2 inhibitor CX-4945 and ROCK inhibitor fasudil did not show such cross-reactivity. In addition, KD025 effectively inhibited CK2 at a nanomolar concentration (IC = 50 nM). We examined if the inhibitory effect of KD025 on adipocyte differentiation is through the inhibition of CK2. Both CX-4945 and KD025 suppressed the generation of lipid droplets and the expression of proadipogenic genes and in 3T3-L1 cells during adipocyte differentiation. Fasudil exerted no significant effect on the quantity of lipid droplets, but another ROCK inhibitor Y-27632 increased the expression of and . Both CX-4945 and KD025 acted specifically in the middle stage (days 1-3) but were ineffective when treated at days 0-1 or the late stages, indicating that CX-4945 and KD025 may regulate the same target, CK2. The mRNA and protein levels of CK2α and CK2β generally decreased in 3T3-L1 cells at day 2 but recovered thereafter. Other well-known CK2 inhibitors DMAT and quinalizarin inhibited effectively the differentiation of 3T3-L1 cells. Taken together, the results of this study confirmed that KD025 inhibits ROCK2 and CK2, and that the inhibitory effect on adipocyte differentiation is through the inhibition of CK2.