Myosin light-chain phosphorylation is the primary mechanism for activating smooth-muscle contraction and occurs principally at Ser-19 of the 20 kDa light chains of myosin (LC(20)). In some circumstances, Thr-18 phosphorylation may also occur. Protein kinase C (PKC) can regulate LC(20) phosphorylation indirectly via signalling pathways leading to inhibition of myosin light-chain phosphatase. The...

Rho-associated kinase (ROCK) regulates neural cell migration, proliferation and survival, dendritic spine morphology, and axon guidance and regeneration. There is, however, little information about whether ROCK modulates the electrical activity and information processing of neuronal circuits. At neonatal stage, ROCKα is expressed in hypoglossal motoneurons (HMNs) and in their afferent inputs, w...

In this study, we propose that diprophylline exerts bidirectional modulation (BM) on the isolated rat jejunal segment depending on its contractile state. The results supported the hypothesis. Diprophylline (20 µM) exerted stimulatory effects on the contractility of jejunal segment in six low contractile states while inhibitory effects in six high contractile states, showing the characteristics ...

We and others have shown that the fetal pulmonary arterial smooth muscle potential for contraction and relaxation is significantly reduced compared with the adult. Whether these developmental changes relate to age differences in the expression and/or activity of key enzymes regulating the smooth muscle mechanical properties has not been previously evaluated. Therefore, we studied the catalytic ...

AIM To examine the effects of Acanthopanax senticosus polysaccharides (ASPS) on intestinal tight junction (TJ) disruption and nuclear factor-kappa B (NF-κB)/myosin light chain kinase (MLCK) activation in endotoxemia. METHODS BALB/C mice (6-8-weeks-old) received continuous intragastric gavage of ASPS for 7 d before injection of lipopolysaccharide (LPS), or received ASPS once after LPS injectio...

Shigella flexneri, the causitive agent of bacillary dysentery, has been shown to disseminate in colonic epithelial cells via protrusions that extend from infected cells and are endocytosed by adjacent cells. This phenomenon occurs in the region of the eukaryotic cell's adherens junctions and is inhibited by pharmacological reagents or host cell mutations that completely disrupt the junctional c...

A defective intestinal epithelial tight junction (TJ) barrier has been proposed as an important pathogenic factor contributing to the intestinal inflammation of Crohn's disease. Glucocorticoids are first-line therapeutic agents for the treatment of moderate to severe Crohn's disease. Glucocorticoid treatment has been shown to induce retightening of the intestinal TJ barrier defect in Crohn's di...

RhoA, an important member of the Rho family of GTPases, has been implicated in many cellular processes. Our pilot study found that RhoA participated in the regulation of vascular reactivity after shock, but the mechanism was incompletely understood. Whether RhoA regulates vascular reactivity through the Rho kinase-myosin light-chain phosphatase (MLCP) and Rac1-p21-activated kinase (PAK)-myosin ...

The functions of long smooth muscle myosin light chain kinase (L-MLCK), a molecule with multiple domains, are poorly understood. To examine the existence of further potentially functional domains in this molecule, we analyzed its amino acid sequence with a tango program and found a putative aggregation domain located at the 4Ig domain of the N-terminal extension. To verify its aggregation capab...

The defective intestinal epithelial tight junction (TJ) barrier has been postulated to be an important pathogenic factor contributing to intestinal inflammation. It has been shown that the proinflammatory cytokine IL-1β causes an increase in intestinal permeability; however, the signaling pathways and the molecular mechanisms involved remain unclear. The major purpose of this study was to inves...