Differential effects of myocilin and optineurin, two glaucoma genes, on neurite outgrowth

Am J Pathol. 2010 Jan;176(1):343-52. doi: 10.2353/ajpath.2010.090194. Epub 2009 Dec 3.

Abstract

Myocilin and optineurin are two genes linked to glaucoma, a major blinding disease characterized by progressive loss of retinal ganglion cells (RGCs) and their axons. To investigate the effects of force-expressed wild-type and mutant myocilin and optineurin on neurite outgrowth in neuronal cells, we transiently transfected cells with pEGFP-N1 (mock control) as well as myocilin and optineurin plasmids including pMYOC(WT)-EGFP, pMYOC(P370L)-EGFP, pMYOC(1-367)-EGFP, pOPTN(WT)-EGFP, and pOPTN(E50K)-EGFP. PC12 cells transfected with pEGFP-N1 produced, as anticipated, long and extensive neuritis on nerve growth factor induction. The neurite length in those cells transfected with myocilin constructs was shortened and the number of neurites was also reduced. A similar inhibitory effect on neurite outgrowth was also elicited by myocilin transfection in RGC5 cells. In contrast, neither transfection of the optineurin constructs pOPTN(WT)-EGFP and pOPTN(E50K)-EGFP nor the myocilin and optineurin small-interfering RNA treatments induced significant alterations in neurite outgrowth. Transfection with the wild-type optineurin construct, but not with that of the wild-type myocilin, increased the apoptotic activity in cells. These results demonstrated that the two glaucoma genes, myocilin and optineurin, exhibited differential effects on neurite outgrowth. They may contribute to the development of neurodegenerative glaucoma via distinct mechanisms.

Publication types

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

MeSH terms

  • Adult
  • Animals
  • Apoptosis / drug effects
  • Caspase 3 / metabolism
  • Caspase 7 / metabolism
  • Colforsin / pharmacology
  • Cytoskeletal Proteins / genetics*
  • Cytoskeletal Proteins / metabolism
  • Cytoskeletal Proteins / pharmacology
  • Endocytosis / drug effects
  • Eye Proteins / genetics*
  • Eye Proteins / metabolism
  • Eye Proteins / pharmacology
  • Fluorescein-5-isothiocyanate / metabolism
  • Glaucoma / genetics*
  • Glycoproteins / genetics*
  • Glycoproteins / metabolism
  • Glycoproteins / pharmacology
  • Humans
  • Middle Aged
  • Mutant Proteins / metabolism
  • Neurites / drug effects
  • Neurites / metabolism*
  • PC12 Cells
  • RNA, Small Interfering / metabolism
  • Rats
  • Recombinant Proteins / pharmacology
  • Solutions
  • Staining and Labeling
  • Young Adult

Substances

  • Cytoskeletal Proteins
  • Eye Proteins
  • Glycoproteins
  • Mutant Proteins
  • RNA, Small Interfering
  • Recombinant Proteins
  • Solutions
  • trabecular meshwork-induced glucocorticoid response protein
  • Colforsin
  • Caspase 3
  • Caspase 7
  • Fluorescein-5-isothiocyanate