Inhibition of MAP kinase activity moderates changes in expression and function of Cx32 but not claudin-1 during DNA synthesis in primary cultures of rat hepatocytes

Medical Electron Microscopy : Official Journal of the Clinical Electron Microscopy Society of Japan
Takashi KojimaNorimasa Sawada

Abstract

The signal transduction pathways and activation of the MAP kinase or PI3 kinase signaling cascade regulate a variety of cellular processes, including proliferation and differentiation in hepatocytes. To elucidate the mechanisms of signal transmission required for the regulation of gap and tight junctions during DNA synthesis in rat hepatocytes, we determined changes of expression and function of gap and tight junctions of cells grown in primary culture, using inhibitors of signaling pathways for MAP kinase (PD98059) and PI3 kinase (LY294002). During the stimulation of DNA synthesis induced by epidermal growth factor (EGF), immunoreactivity and mRNAs of gap junction protein Cx32 and of tight junction protein claudin-1 markedly decreased with reduction of gap junctional intercellular communication (GJIC) and the fence function of tight junctions. In Western blots, whole-cell lysate of claudin-1 protein decreased and phosphorylated Cx32 protein in the insoluble fraction of Triton X-100 increased during the stimulation of DNA synthesis. During reinhibition of DNA synthesis, the changes of Cx32 and claudin-1 returned to control levels, as did both functions. In treatment with the inhibitors before DNA synthesis, PD98059 inhibited th...Continue Reading

Citations

May 1, 2012·Histochemistry and Cell Biology·Marie OgawaNorimasa Sawada
Apr 14, 2005·Journal of Hepatology·Toshinobu YamamotoNorimasa Sawada
Aug 31, 2010·Biochimica Et Biophysica Acta·Mathieu VinkenVera Rogiers
Dec 7, 2007·Hepatology : Official Journal of the American Association for the Study of Liver Diseases·Mathieu VinkenVera Rogiers
Mar 24, 2016·Cell Communication & Adhesion·Joost WillebrordsMathieu Vinken
Jul 29, 2009·Critical Reviews in Biochemistry and Molecular Biology·Mathieu VinkenVera Rogiers

❮ Previous
Next ❯

Related Concepts

Related Feeds

AKT Pathway

This feed focuses on the AKT serine/threonine kinase, which is an important signaling pathway involved in processes such as glucose metabolism and cell survival.