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Updated: Aug 29, 2026

Isolation of Primary Patient-specific Aortic Smooth Muscle Cells and Semiquantitative Real-time Contraction Measurements In Vitro
Published on: February 15, 2022
Disruption of the actin cytoskeleton up-regulates iNOS expression in vascular smooth muscle cells
Yoshiyuki Hattori1, Kikuo Kasai
1Department of Endocrinology & Metabolism, Dokkyo University School of Medicine, Mibu, Tochigi, Japan. yhattori@dokkyomed.ac.jp
Abstract:
Cytokines and bacterial lipopolysaccharide (LPS) induce the expression of inducible nitric oxide synthase (iNOS), resulting in the release of nitric oxide (NO) from vascular smooth muscle cells. We here demonstrated that disruption of F-actin formation by sequestration of G-actin with the toxin latrunculin B (Lat B) dramatically potentiated LPS-induced iNOS mRNA and protein expression. We also showed that Lat B enhanced interleukin-1beta- andbgr;- and TNFalpha-induced NO production. Lat B by itself had little or no effect on iNOS expression. Cytochalasin D also enhanced LPS-induced NO production. Lat B dose-dependently enhanced LPS-induced iNOS promoter activity but had no effect on the stability of iNOS mRNA. Staining of F-actin with nitrobenzoxadiazole (NBD)-phallacidin demonstrated that Lat B significantly impaired F-actin stress fiber formation. These data indicate that disruption of the actin cytoskeleton up-regulates cytokine-induced iNOS expression via transcriptional regulation. Further analysis of the signaling pathway from the actin cytoskeleton to iNOS expression may yield new insight into the mechanism of iNOS regulation.
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