Inhibition Of Rho-associated Kinase Activity Research Articles

ROCK Inhibition Drives Resolution of Acute Inflammation by Enhancing Neutrophil Apoptosis.

Uncontrolled inflammation leads to tissue damage and it is central for the development of chronic inflammatory diseases and autoimmunity. An acute inflammatory response is finely regulated by the action of anti-inflammatory and pro-resolutive mediators, culminating in the resolution of inflammation and restoration of homeostasis. There are few studies investigating intracellular signaling pathways associated with the resolution of inflammation. Here, we investigate the role of Rho-associated kinase (ROCK), a serine/threonine kinase, in a model of self-resolving neutrophilic inflammatory. We show that ROCK activity, evaluated by P-MYPT-1 kinetics, was higher during the peak of lipopolysaccharide-induced neutrophil influx in the pleural cavity of mice. ROCK inhibition by treatment with Y-27632 decreased the accumulation of neutrophils in the pleural cavity and was associated with an increase in apoptotic events and efferocytosis, as evaluated by an in vivo assay. In a model of gout, treatment with Y-27632 reduced neutrophil accumulation, IL-1β levels and hypernociception in the joint. These were associated with reduced MYPT and IκBα phosphorylation levels and increased apoptosis. Finally, inhibition of ROCK activity also induced apoptosis in human neutrophils and destabilized cytoskeleton, extending the observed effects to human cells. Taken together, these data show that inhibition of the ROCK pathway might represent a potential therapeutic target for neutrophilic inflammatory diseases.

A novel cardioprotective mechanism of exogenous nitric oxide: inhibition of Rho-associated kinase activity.

A novel cardioprotective mechanism of exogenous nitric oxide: inhibition of Rho-associated kinase activity

Rho-Associated Kinase Activity Is a Predictor of Cardiovascular Outcomes

Cardiovascular diseases are associated with chronic activation of Rho-associated kinase. Rho-associated kinase activity is significantly correlated with endothelial function and Framingham risk score. However, there is no information on the prognostic value of Rho-associated kinase activity. We evaluated Rho-associated kinase activity in peripheral leukocytes by Western blot analysis in 633 subjects who underwent health-screening examination at Hiroshima University Hospital. We assessed the associations between Rho-associated kinase activity and first major cardiovascular events (death from cardiovascular causes, myocardial infarction, and stroke), death from cardiovascular causes, acute myocardial infarction, stroke, revascularization (percutaneous coronary intervention, coronary artery bypass grafting), and hospitalization for heart failure. During a median period of 42.0 months (interquartile range, 24.4-56.6 months) of follow-up, 29 subjects died (10 from cardiovascular causes), 2 myocardial infarction, 20 revascularization, 15 stroke, and 17 hospitalization for heart failure. After adjustment for age, sex, cardiovascular risk factors, and other relevant variables, Rho-associated kinase activity remained a strong independent indicator of first major cardiovascular events (hazard ratio, 2.19; 95% confidence interval, 1.35-3.70; P=0.002), death from cardiovascular disease (hazard ratio, 2.57; 95% confidence interval, 1.18-6.60; P=0.002), stroke (hazard ratio, 2.14; 95% confidence interval, 1.24-3.86; P=0.006), and revascularization (hazard ratio, 2.68; 95% confidence interval, 1.60-4.66; P<0.001). Leukocyte Rho-associated kinase activity may be a new biomarker of cardiovascular events. These findings suggest that inhibition of Rho-associated kinase activity may be a therapeutic target for prevention of cardiovascular events.

Quantum dots (QDs) restrain human cervical carcinoma HeLa cell proliferation through inhibition of the ROCK-c-Myc signaling

Cancers often cause significant morbidity and even death to patients. To date, conventional therapies, such as chemotherapy, radiation and surgery, are often limited; meanwhile, novel anticancer therapeutics are urgently needed to improve clinical treatments. Rapid application of nanotechnology and nanomaterials represents a promising vista for the development of anti-cancer therapeutics. However, how to integrate the novel properties of nanotechnology and nanomaterials into cancer treatment warrants close investigation. In the current study, we report a novel finding about the inhibitory effect of CdSe quantum dots (QDs) on Rho-associated kinase (ROCK) activity in cervical carcinoma HeLa cells associated with the attenuation of the ROCK-c-Myc signaling. We mechanistically demonstrated that QD-conducted ROCK inhibition greatly diminished c-Myc protein stability due to reduced phosphorylation, and also suppressed its activity in transcribing target genes (e.g. HSPC111). Thus, the treatment of QDs greatly restrained HeLa cell growth by inducing cell cycle arrest at G1 phase due to the reduced ability of c-Myc in driving cell proliferation. Additionally, since HSPC111, one of the c-Myc targets, is involved in regulating cell growth through ribosomal biogenesis and assembly, the downregulation of HSPC111 could also contribute to diminished proliferation in HeLa cells upon QD treatment. These results together suggested that inhibition of ROCK activity or ROCK-mediated c-Myc signaling in tumor cells upon QD treatment might represent a promising strategy to restrain tumor progression for human cervical carcinoma.

Melanoma Cell Invasiveness Is Promoted at Least in Part by the Epidermal Growth Factor–Like Repeats of Tenascin-C

Tenascin-C (TNC), overexpressed in invasive growths, has been implicated in progression of melanoma but the source and function of this molecule are not well defined. We found TNC expression at the front of invading melanoma cells, and that adding TNC to matrices enhances individual melanoma cell migration. As TNC is a multidomain protein, we examined the role of the TNC EGF-like repeats (EGFL) as these activate motogenic signaling cascades. We overexpressed a TNC fragment containing the assembly and EGFL domains of TNC (TNCEGFL). TNCEGFL-expressing melanoma cells had lower speed and persistence in 2D migration assays due to a shift in the adhesion-contractility balance, as expression of TNCEGFL delayed melanoma cell attachment and spreading. The less adhesive phenotype was due, in part, to increased ROCK signaling concomitant with MLC2 and MYPT phosphorylation. Inhibition of ROCK activity, which drives transcellular contractility, restored adhesion of TNCEGFL expressing melanoma cells and increased their migration in 2D. In contrast to the diminished migration in 2D, TNCEGFL-expressing melanoma cells had higher invasive potential in Matrigel invasion assays, with cells expressing TNCEGFL having amoeboid morphology. Our findings suggest that melanoma-derived TNC EGFL play a role in melanoma invasion by modulating ROCK signaling and cell migration.

Rho kinase inhibitors stimulate the migration of human cultured osteoblastic cells by regulating actomyosin activity

We investigated the effects of Rho-associated kinase (ROCK) on migration and cytoskeletal organization in primary human osteoblasts and Saos-2 human osteosarcoma cells. Both cell types were exposed to two different ROCK inhibitors, Y-27632 and HA-1077. In the improved motility assay used in the present study, Y-27632 and HA-1077 significantly increased the migration of both osteoblasts and osteosarcoma cells on plastic in a dose-dependent and reversible manner. Fluorescent images showed that cells of both types cultured with Y-27632 or HA-1077 exhibited a stellate appearance, with poor assembly of stress fibers and focal contacts. Western blotting showed that ROCK inhibitors reduced myosin light chain (MLC) phosphorylation within 5 min without affecting overall myosin light-chain protein levels. Inhibition of ROCK activity is thought to enhance the migration of human osteoblasts through reorganization of the actin cytoskeleton and regulation of myosin activity. ROCK inhibitors may be potentially useful as anabolic agents to enhance the biocompatibility of bone and joint prostheses.

Korean Red Ginseng Improves Vascular Stiffness in Patients with Coronary Artery Disease

Korean red ginseng (KRG) has been shown to enhance endothelium-dependent vasorelaxation in experimental animals; however, little is known about its pharmacological effects on vascular stiffness in patients with coronary artery disease (CAD). This randomized, double-blind, placebo-controlled crossover trial was carried out to determine whether KRG has beneficial effects on arterial stiffness, cardiovascular risk factors such as plasma lipid profiles and blood pressure (BP), and Rho-associated kinase (ROCK) activity. Twenty patients (mean age, 62.5 years) with stable angina pectoris were given KRG (2.7 g/day) and a placebo alternatively for 10 weeks. Blood biochemical analysis and pulse wave velocity (PWV) recording were performed on day 0 and after the completion of each treatment. ROCK activity was assessed based on the level of phospho-<TEX>$Thr^{853}$</TEX> in the myosin-binding subunit of myosin light chain phosphatase, determined by Western blot analysis of peripheral blood mononuclear cells. KRG significantly decreased the systolic BP, brachial ankle PWV, and heart femoral PWV in the patients (all p<0.05), but did not significantly alter the serum lipid profiles, including triglycerides and total, high-density lipoprotein, and low-density lipoprotein cholesterol levels. The ROCK activity tended to decrease (p=0.068) following KRG treatment. The placebo did not significantly alter any of the variables. In conclusion, KRG decreased systolic BP and arterial stiffness, probably via the inhibition of ROCK activity, in patients with CAD, but had a neutral effect on serum lipid profiles. Our data suggest that KRG has a therapeutic effect on CAD.