Calcium-independent phospholipase A2 regulates retinal pigment epithelium proliferation and may be important in the pathogenesis of retinal diseases

Exp Eye Res. 2009 Sep;89(3):383-91. doi: 10.1016/j.exer.2009.04.002. Epub 2009 Apr 18.

Abstract

Calcium-independent phospholipase A2, group VIA (iPLA2-VIA) is involved in cell proliferation. This study aimed to evaluate the role of iPLA2-VIA in retinal pigment epithelium (RPE) cell proliferation and in retinal diseases involving RPE proliferation. A human RPE cell line (ARPE-19) was used to explore this role in vitro. Proliferating ARPE-19 cells had increased expression and activity of iPLA2-VIA. iPLA2-VIA was found in the nuclei of proliferating ARPE-19 cells, whereas in confluent ARPE-19 cells, with limited proliferation, iPLA2-VIA was primarily found in the cytosol. Inhibition of iPLA2-VIA decreased the rate of proliferation, whereas over expression of iPLA2-VIA increased the rate of proliferation. Using an experimental porcine model of RPE proliferation we demonstrated significant nuclear upregulation of iPLA2-VIA in proliferating RPE cells in vivo. We furthermore evaluated the expression of iPLA2-VIA in proliferative vitreoretinopathy (PVR). PVR membranes revealed nuclear expression of iPLA2-VIA in the RPE cells which had migrated and participated in the formation of the membranes. Overall, the present results point to an important role of iPLA2-VIA in the regulation of RPE proliferation suggesting that iPLA2-VIA may be considered as a possible pharmaceutical target in retinal diseases involving RPE proliferation and migration.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing
  • Animals
  • Cell Nucleus / enzymology
  • Cell Nucleus / metabolism
  • Cell Proliferation
  • Cells, Cultured
  • Endoplasmic Reticulum / enzymology
  • Gene Silencing
  • Humans
  • Phospholipases A2, Calcium-Independent / genetics
  • Phospholipases A2, Calcium-Independent / physiology*
  • RNA, Small Interfering / genetics
  • Retinal Pigment Epithelium / cytology*
  • Retinal Pigment Epithelium / enzymology
  • Retinal Pigment Epithelium / pathology
  • Sus scrofa
  • Vitreoretinopathy, Proliferative / enzymology*
  • Vitreoretinopathy, Proliferative / pathology

Substances

  • RNA, Small Interfering
  • Phospholipases A2, Calcium-Independent