Melanopsin-expressing retinal ganglion cells are resistant to cell injury, but not always

Mitochondrion. 2017 Sep:36:77-84. doi: 10.1016/j.mito.2017.04.003. Epub 2017 Apr 12.

Abstract

Melanopsin retinal ganglion cells (mRGCs) are intrinsically photosensitive RGCs deputed to non-image forming functions of the eye such as synchronization of circadian rhythms to light-dark cycle. These cells are characterized by unique electrophysiological, anatomical and biochemical properties and are usually more resistant than conventional RGCs to different insults, such as axotomy and different paradigms of stress. We also demonstrated that these cells are relatively spared compared to conventional RGCs in mitochondrial optic neuropathies (Leber's hereditary optic neuropathy and Dominant Optic Atrophy). However, these cells are affected in other neurodegenerative conditions, such as glaucoma and Alzheimer's disease. We here review the current evidences that may underlie this dichotomy. We also present our unpublished data on cell experiments demonstrating that melanopsin itself does not explain the robustness of these cells and some preliminary data on immunohistochemical assessment of mitochondria in mRGCs.

Keywords: Alzheimer; Dominant optic atrophy; Leber's hereditary optic neuropathy; Light; Melanopsin; Mitochondria; Optic atrophy; Retinal ganglion cells; Robustness.

Publication types

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

MeSH terms

  • Gene Expression*
  • Humans
  • Mitochondrial Diseases / pathology*
  • Optic Nerve Diseases / pathology*
  • Retinal Ganglion Cells / pathology*
  • Retinal Ganglion Cells / physiology*
  • Rod Opsins / biosynthesis*
  • Stress, Physiological*

Substances

  • Rod Opsins
  • melanopsin