Statin blocks Rho/Rho-kinase signalling and disrupts the actin cytoskeleton: relationship to enhancement of LPS-mediated nitric oxide synthesis in vascular smooth muscle cells. | LitMetric
We previously demonstrated statins to enhance cytokine-mediated nitric oxide (NO) synthesis in vascular smooth muscle cells (VSMC). To clarify the mechanism by which this occurs, we evaluated the effects of fluvastatin in lipopolysaccharide (LPS)-stimulated VSMC. NO production induced by LPS was dose-dependently enhanced by fluvastatin, as were iNOS mRNA levels and iNOS protein expression. Exogenous mevalonate and geranylgeranylpyrophosphate (GGPP) dampened the stimulatory effect of fluvastatin. A pull-down assay demonstrated fluvastatin to decrease levels of GTP-bound Rho A. Moreover, a Rho-kinase inhibitor, Y-27632, was observed to enhance LPS-induced NO production. We recently demonstrated that disrupting F-actin formation dramatically potentiates the ability of LPS to induce iNOS mRNA and protein expression. In the present study, staining of F-actin with nitrobenzoxadiazole (NBD)-phallacidin demonstrated that fluvastatin significantly impairs F-actin stress fiber formation. In light of these results, the ability of statins to increase NO production is due, at least in part, to their ability to block the biosynthesis of mevalonate, thereby preventing isoprenoid biosynthesis. This inhibits Rho/Rho-kinase signalling and, in turn, disrupts the actin cytoskeleton. Further analysis of the signalling pathway by which the actin cytoskeleton affects iNOS expression might yield new insight into mechanisms of regulation of NO production.
Wiskott-Aldrich syndrome (WAS) is a severe X-linked disorder caused by loss-of-function mutations in the WAS gene, responsible for encoding WASP, a key regulator of actin cytoskeleton in all hematopoietic cells except red blood cells. The mechanism underlying microthrombocytopenia, a distinctive feature of WAS and a major contributor to mortality, remains not fully elucidated. In this study, using different gene editing strategies, we corrected mutations in patient-derived WAS-induced pluripotent stem cell lines, generating isogeneic WAS iPSC lines.
Department of Hematology, The First Affiliated Hospital of USTC, Key Laboratory of Immune Response and Immunotherapy, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Institute of Blood and Cell Therapy and Anhui Provincial Key Laboratory of Blood Research and Applications, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.
The engraftment of haematopoietic stem and progenitor cells (HSPCs), particularly in cord-blood transplants, remains challenging. Here we report the role of the corticotropin-releasing hormone (CRH) in enhancing the homing and engraftment of human-cord-blood HSPCs in bone marrow through mechanical remodelling. By using microfluidics, intravital two-photon imaging and long-term-engraftment assays, we show that treatment with CRH substantially enhances HSPC adhesion, motility and mechanical remodelling, ultimately leading to improved bone-marrow homing and engraftment in immunodeficient mice.
Disulfidptosis is a recently identified form of cell death characterized by the aberrant accumulation of cellular disulfides. This process primarily occurs in glucose-starved cells expressing higher levels of SLC7A11 and has been proposed as a therapeutic strategy for cancers with hyperactive SCL7A11. However, the potential for inducing disulfidptosis through other mechanisms in cancers remains unclear.
is the etiologic agent of trichomoniasis, one of the most common non-viral sexually transmitted infections globally. Our previous work reported the role of phosphatidylinositol 4,5-bisphosphates (PIP) signaling in the actin-dependent pathogenicity of . This study further demonstrated that iron transiently regulated phosphatidylinositol-4-phosphate 5-kinase (PI4P5K) proteostasis and its complex formation with an active ADP ribosylation factor Arf220, facilitating co-trafficking to the plasma membrane, crucial for PIP production.
