The human Müller cell line MIO-M1 expresses opsins

Mol Vis. 2011:17:2738-50. Epub 2011 Oct 20.

Abstract

Purpose: To determine whether the human Müller cell line Moorfields/Institute of Ophthalmology-Müller 1 (MIO-M1) expresses opsins.

Methods: The gene expression of opsins was determined by reverse-transcription PCR (RT-PCR). The presence of opsin proteins was determined by western blotting and immunocytochemistry. The light sensitivity of the cells was examined with imaging experiments using the calcium-sensitive dye Fluo-4.

Results: MIO-M1 cells express glial (glutamine synthase [GLUL], vimentin [VIM], glial fibrillary acidic protein [GFAP], cellular retinaldehyde-binding protein [RLBP1], glial high-affinity glutamate transporter [SLCA1], aquaporin-4 [AQP4], inwardly rectifying potassium channel Kir4.1 [Kir4.1]), neuronal (Thy-1 cell surface antigen [THY1], heavy neurofilament polypeptide [NEFH], microtubule-associated protein 2 [MAP2], neurogenic differentiation 1 [NEUROD1], neuronal nuclei [NEUN]), and neural progenitor markers (Nestin [NES], paired-type homeobox transcription factor [PAX6], neurogenic locus notch homolog 1 [NOTCH1]). The cells contain mRNA for the following opsins: blue opsin (OPN1SW), rhodopsin (OPN2), panopsin (OPN3), melanopsin (OPN4), neuropsin (OPN5), and peropsin (RRH), as well as for the transducins (guanine nucleotide binding protein [GNAZ], alpha transducing activity polypeptide 1 [GNAT1], alpha transducing activity polypeptide 2 [GNAT2]). The presence of blue opsin and melanopsin was confirmed with immunocytochemistry and western blotting. The immunoreactivity and mRNA of red-green opsin were found in some but not all cultures, while the immunoreactivity for rhodopsin was absent in all cultures investigated. Repetitive stimulation with 480 nm light evoked slow and fast transient calcium responses in the majority of cells investigated, while irradiation with 600 nm light was ineffective.

Conclusions: The human Müller cell line MIO-M1 expresses opsins. This suggests immortalized Müller cells could be used as a cellular source to produce human opsins for their potential application as therapeutic agents in patients with retinitis pigmentosa.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aniline Compounds / analysis
  • Blotting, Western
  • Calcium / metabolism
  • Cell Line*
  • Gene Expression / radiation effects*
  • Humans
  • Immunohistochemistry
  • Light
  • Opsins / biosynthesis*
  • Opsins / genetics
  • Opsins / pharmacology
  • RNA, Messenger / analysis
  • RNA, Messenger / biosynthesis
  • Retina / metabolism*
  • Retina / pathology
  • Retina / radiation effects
  • Retinitis Pigmentosa / drug therapy
  • Retinitis Pigmentosa / metabolism*
  • Retinitis Pigmentosa / pathology
  • Xanthenes / analysis

Substances

  • Aniline Compounds
  • Fluo 4
  • Opsins
  • RNA, Messenger
  • Xanthenes
  • Calcium