ABSTRACT
Interleukin-27 (IL-27), a heterodimeric cytokine, plays a protective role in diabetes. Ghrelin, a gastric hormone, provides a hunger signal to the central nervous system to stimulate food intake. The relationship between IL-27 and ghrelin is still unexplored. Here we investigated that signal transducer and activator of transcription 3 (STAT3)-mechanistic target of rapamycin (mTOR) signaling mediates the suppression of ghrelin induced by IL-27. Co-localization of interleukin 27 receptor subunit alpha (WSX-1) and ghrelin was observed in mouse and human gastric mucosa. Intracerebroventricular injection of IL-27 markedly suppressed ghrelin synthesis and secretion while stimulating STAT3-mTOR signaling in both C57BL/6J mice and high-fat diet-induced-obese mice. IL-27 inhibited the production of ghrelin in mHypoE-N42 cells. Inhibition of mTOR activity induced by siRNA or rapamycin blocked the suppression of ghrelin production induced by IL-27 in mHypoE-N42 cells. siRNA also abolished the inhibitory effect of IL-27 on ghrelin. IL-27 increased the interaction between STAT3 and mTOR in mHypoE-N42 cells. In conclusion, IL-27 suppresses ghrelin production through the STAT3-mTOR dependent mechanism.
ABSTRACT
AIM To study the effects of protein tyrosine kinase inhibitor and protein tyrosine phosphatase inhibitor on cultured bovine cerebrovascular smooth muscle cells (CSMC) Ca 2+ store operated Ca 2+ influx. METHODS Cell culture and single intracellular free Ca 2+ concentration was measured in fura 2/Am flueorescence probe by MetaFluor Fluorescence ratio imaging system. RESULTS (1) protein tyrosine kinase inhibitor (genistein,2.5,5,10 ?mol?L -1 )decreased Ca 2+ influx significantly induced by endothelin 1(ET 1),ATP,cyclopiazonic acid(CPA) in concentration dependent manner; (2) Protein tyrosine phosphatase inhibitor (vanadate,2,4,8 ?mol?L -1 ) increased Ca 2+ influx significantly induced by ET 1,ATP,CPA in concentration dependent manner. CONCLUSION Protein tyrosine kinase inhibitor and protein tyrosine phosphatase inhibitor have effects on Ca 2+ store operated Ca 2+ influx induced by ET 1, ATP, CPA. Protein tyrosine phosphorylation participats in the signal transduction of Ca 2+ store operat Ca 2+ influx in cerebrovascular smooth muscle cells.
ABSTRACT
AIM To study the effects of endothelin 1(ET 1) on ClC 3 chloride channel protein expression in cultured bovine cerebrovascular smooth muscle cells (CSMC). METHODS Cell culture and Western blot. RESULTS ① The endogenous ClC 3 expression was found in basilar artery, middle cerebral artery, and microvessel; ② The molecular weight of expressed ClC 3 chloride channel protein was about 95 ku; ③ ET 1 enhanced ClC 3 protein expression which was inhibited by nifedipine and SK&F96365. Cyclopiazonic acid(CPA) increased the expression of ClC 3 protein in a concentration dependant manner, and enhanced ET 1 effect on this protein expression. CONCLUSION ET 1 stimulated ClC 3 chloride channel protein expression in cultured bovine cerebrovascular smooth muscle cells. The intracellular Ca 2+ plays an important role on signal transduction pathway in ClC 3 protein expression process.
ABSTRACT
Cl - ,ClC 3 chloride current can be inhibited by chloride channel inhibitor DIDS?tamoxifen and extracellular ATP. ClC 3 is modulated by cell volume and regulated by PKC.The present review discusses the expression, eletrophysiology,molecular properties,signal transduction of such channel.