Non-muscle Cells (non-muscle + cell)

Distribution by Scientific Domains

Selected Abstracts

Characterization of Bves expression during mouse development using newly generated immunoreagents

Travis K. Smith
Abstract Bves (blood vessel/epicardial substance) is a transmembrane protein postulated to play a role in cell,cell interaction/adhesion. It was independently isolated by two groups as a gene product highly enriched in the developing heart. Disagreement exists about its expression during development. Most notably, the expression of Bves in non-muscle cells is disputed. Determining the expression profile of Bves is a critical initial step preceding the characterization of protein function in development and in the adult. We have generated new monoclonal antibodies against mouse Bves and used these immunoreagents to elucidate Bves expression in development. As expected, we detect Bves in myocytes of the developing heart throughout development. In addition, skeletal and smooth muscle cells including those of the coronary system express Bves. Finally, specific, but not all, epithelial derivatives of the three germ layers are stained positively with these monoclonal antibodies. Protein expression in cultured epithelial and muscle cell lines corroborate our in vivo findings. Taken together, these results demonstrate the expression of Bves in a wide range of epithelial and muscle cells during mouse embryogenesis and indicate a broad function for this protein in development, and show that these newly generated reagents will be invaluable in further investigation of Bves. Developmental Dynamics 235:1701,1708, 2006. 2006 Wiley-Liss, Inc. [source]

Mechanisms of actin stress fibre assembly

Summary Stress fibres are contractile acto-myosin structures found from many types of non-muscle cells, where they are involved in adhesion, motility and morphogenesis. Stress fibres typically display a periodic ,-actinin,myosin II pattern and are thus suggested to resemble the sarcomeric actin filament structures of muscle cells. Mammalian cells contain three categories of stress fibres: ventral stress fibres that are attached to focal adhesions at both ends, dorsal stress fibres that are attached to focal adhesions typically at one end and transverse arcs that are curved acto-myosin bundles, which do not directly attach to focal adhesions. In this review, we discuss the definition of stress fibres, organization of actin filaments and other components within these contractile structures, and the mechanisms of stress fibre assembly. [source]

Genes Differentially Expressed By Schwann Cells Of Motor Versus Sensory Nerves

D Imperiale
Charcot-Marie-Tooth (CMT) disease includes a heterogeneous group of inherited demyelinating peripheral neuropathies related to genetic defects of myelin-forming Schwann cells (SC). In CMT, as in other common acquired demyelinating neuropathies (Guillain Barr syndrome, chronic inflammatory demyelinating polyneuropathy), motor nerves are invariably more involved than sensory nerves. Also in transgenic mouse models of peripheral neuropathy, there is a preferential demyelination of motor districts independent of the type of genetic alteration. The basis for differential susceptibility to demyelination is unknown. The aim of this study was to identify differences in gene and protein expression that may underlie the differential susceptibility to demyelination of motor and sensory myelin-forming SC. Since spinal roots are the only portion of mammalian PNS in which motor and sensory axons are segregated, we extracted RNA from adult rat dorsal (sensory) and ventral (motor) spinal roots and compared corresponding cDNAs by an RNA fingerprint approach. Four differentially displayed bands were isolated. We first characterized the most differentially expressed band, which was highly enriched in sensory roots. Sequence analysis showed that the band encoded a portion of rat sarco/endoplasmic reticulum calcium transporting ATPase type 1 coding sequence (SERCA1). RT-PCR experiments confirmed SERCA1 enrichment in dorsal sensory roots. SERCA enzymes are ubiquitous calcium regulatory systems in muscle and non-muscle cells and SERCA1 is selectively enriched in skeletal muscle. To our knowledge, no studies have investigated SERCA isoform expression in peripheral nerve. Identification of a calcium regulatory molecule in SC is interesting, as calcium is essential for the proper structure and function of the nodal and paranodal portions of SC, as well as the myelin sheath. However, calcium homeostasis in SC is relatively unexplored. Experiments to localize SERCA1 transcript and protein in different PNS districts and to clarify its functional role in peripheral nerve are underway. [source]

Signal transduction by G-proteins, Rho-kinase and protein phosphatase to smooth muscle and non-muscle myosin II

Andrew P. Somlyo
We here review mechanisms that can regulate the activity of myosin II, in smooth muscle and non-muscle cells, by modulating the Ca2+ sensitivity of myosin regulatory light chain (RLC) phosphorylation. The major mechanism of Ca2+ sensitization of smooth muscle contraction and non-muscle cell motility is through inhibition of the smooth muscle myosin phosphatase (MLCP) that dephosphorylates the RLC in smooth muscle and non-muscle. The active, GTP-bound form of the small GTPase RhoA activates a serine/threonine kinase, Rho-kinase, that phosphorylates the regulatory subunit of MLCP and inhibits phosphatase activity. G-protein-coupled release of arachidonic acid may also contribute to inhibition of MLCP acting, at least in part, through the Rho/Rho-kinase pathway. Protein kinase C(s) activated by phorbol esters and diacylglycerol can also inhibit MLCP by phosphorylating and thereby activating CPI-17, an inhibitor of its catalytic subunit; this mechanism is independent of the Rho/Rho-kinase pathway and plays only a minor, transient role in the G-protein-coupled mechanism of Ca2+ sensitization. Ca2+ sensitization by the Rho/Rho-kinase pathway contributes to the tonic phase of agonist-induced contraction in smooth muscle, and abnormally increased activation of myosin II by this mechanism is thought to play a role in diseases such as high blood pressure and cancer cell metastasis. [source]

In Vitro and In Vivo Relaxation of Corpus Cavernosum Smooth Muscle by the Selective Myosin II Inhibitor, Blebbistatin

Xin-hua Zhang MD
ABSTRACT Introduction., Blebbistatin (BLEB) is a small cell permeable molecule originally reported as a selective inhibitor of myosin II isoforms expressed by striated muscle and non-muscle cells (IC50 = 0.5,5 M) with poor inhibition of turkey gizzard smooth muscle (SM) myosin II (IC50,80 M). However, recently it was found that BLEB can potently inhibit mammalian arterial SM (IC50,5 M). Aim., To investigate the effect of BLEB on corpus cavernosum SM (CCSM) tone and erectile function (EF). Methods., CC tissue obtained from penile implant patients along with CC, aorta and bladder from adult male rats were used for BLEB organ bath studies. Intracavernosal BLEB was administered to rats and EF was assessed via intracavernous pressure (ICP). Main Outcome Measures., Effects of BLEB on agonist-induced CCSM, aorta and bladder contraction in vitro and ICP in vivo. Results., BLEB completely relaxed human CCSM pre-contracted with phenylephrine (PE) in a dose-dependent manner decreasing tension by 76.5% at 10 M. BLEB pre-incubation attenuated PE-induced contraction of human CC by ,85%. Human CC strips pre-contracted with endothelin-1 or KCl were almost completely relaxed by BLEB. Rat CCSM pre-contracted with PE showed BLEB relaxation comparable to human CCSM. BLEB inhibition was similar for rat aorta but slower for bladder. Both maximal ICP and ICP/mean arterial pressure were dose-dependently increased by BLEB intracavernous injections with full erection at 1 micromole. Conclusion., Our novel data reveals that BLEB nearly completely relaxes rat and human CCSM pre-contracted with a variety of potent agonists and exhibits tissue selectivity. Coupled with our in vivo data in which nanomole doses of BLEB significantly increase ICP, our data substantiates an important role for the SM contractile apparatus in the molecular mechanism for EF and suggests the possibility of BLEB binding at myosin II as a therapeutic treatment for ED by targeting SM contractile pathways. Zhang X, Aydin M, Kuppam D, Melman A, and DiSanto ME. In vitro and in vivo relaxation of corpus cavernosum smooth muscle by the selective myosin II inhibitor, blebbistatin. J Sex Med 2009;6:2661,2671. [source]