LIM kinase inhibition reduces endothelial cell cortical stiffness in diabetic arteries

Abstract

Type 2 diabetes is associated with endothelial stiffening, which precedes the development of increased arterial stiffness. The role of endothelial cell stiffening in the pathogenesis of vascular disease is increasingly recognized. Indeed, evidence exists that cellular pathways that result in polymerization of endothelial cell actin filaments (F-actin) and increased cellular stiffness impair the formation of nitric oxide, a potent vasodilator and anti-inflammatory molecule. We and others have shown that, in vascular smooth muscle cells, LIM kinase (LIMK) is a critical regulator of actin dynamics and cellular stiffness via the phosphorylation and consequent inactivation of the F-actin severing molecule, cofilin. However, whether LIMK regulates actin polymerization and stiffness in endothelial cells remains unknown. Here we report that pharmacological inhibition of LIMK with LIMKi3 in cultured human endothelial cells for 18 hours decreases cofilin phosphorylation and cortical stiffness, as assessed by atomic force microscopy. These endothelial softening effects are accompanied with a reduction in F-actin content. Reduced F-actin in endothelial cells is also recapitulated with S3, a cofilin mimetic. Furthermore, we show that the aortic endothelium of diabetic ( i.e., db/db) male mice is stiffer than that of wild-type counterparts, and that stiffer diabetic arteries also exhibit a tendency for increased p-cofilin. Notably, treatment of diabetic aortas with LIMKi3 for 18 hours also reduces endothelial cortical stiffness. Collectively, our findings demonstrate that LIMK inhibition reduces endothelial cortical stiffness in naïve cultured endothelial cells and in diabetic arteries ex vivo. These findings support the hypothesis that LIMK may serve as a potential target for reversing endothelial stiffening in type 2 diabetes. Funding: R01HL151384, R01HL153264, and R01HL137769 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.