Inhibition of Rho-kinase induces αB-crystallin expression in lens epithelial cells

Rahul N. Khurana, Rupa Latha Maddala, Hiroaki Shimokawa, J. Samuel Zigler, David L. Epstein, P. Vasantha Rao

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

The small heat shock protein, αB-crystallin, has been shown to interact with actin and intermediate filament proteins. However, little is known regarding the cellular mechanisms regulating such interactions. In this study, we explored the role of the Rho/Rho-kinase pathway in αB-crystallin distribution and expression in porcine lens epithelial cells. αB-crystallin was distributed uniformly throughout the cytoplasm and did not exhibit any unique redistribution in response to actin depolymerization induced by Rho/Rho-kinase inhibitors (C3-exoenzyme or Y-27632) or by overexpression of the dominant negative mutant of Rho-kinase (DNRK) in porcine lens epithelial cells. Interestingly, αB-crystallin levels markedly increased in lens epithelial cells treated with the inhibitors of Rho/Rho-kinase proteins (lovastatin, Y-27632 or DNRK) while a protein kinase C inhibitor (GF109203x) was found to have no effect. Further, Y-27632 showed a dose (2-50 μM) response effect on αB-crystallin induction. Nocodazole, a microtubule-depolymerizing agent, elicited an increase in αB-crystallin levels but latrunculin, an actin depolymerizing agent, did not show any significant effect. Pretreatment with cycloheximide or genistein blocked the Rho-kinase inhibitor-induced increase in αB-crystallin protein levels. Rho-kinase inhibitor-induced increases in αB-crystallin levels were found to be associated with activation of P38 mitogen-activated protein kinase (MAPK). These results suggest that Rho/Rho-kinase negatively regulates αB-crystallin expression, and this response appears to be dependent on tyrosine-protein kinase and P38 MAPK function. Finally, αB-crystallin induction appears to be better correlated with the direct inhibition of Rho/Rho-kinase than with actin depolymerization per se.

Original languageEnglish
Pages (from-to)981-987
Number of pages7
JournalBiochemical and biophysical research communications
Volume294
Issue number5
DOIs
Publication statusPublished - 2002 Jan 1

Keywords

  • Actin
  • Cytoskeleton
  • Lens epithelial cells
  • P38 MAPK
  • Rho GTPase
  • Rho kinase
  • αB-crystallin

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Inhibition of Rho-kinase induces αB-crystallin expression in lens epithelial cells'. Together they form a unique fingerprint.

Cite this