title: The human Müller cell line MIO-M1 expresses opsins.
abstract: OBJECTIVE
  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.
authors: Department of Ophthalmology and Eye Hospital, University of Leipzig, Leipzig, Germany. hollbm@medizin.uni-leipzig.de
authors: Margrit
authors: M
authors: Hollborn
authors: Elke
authors: E
authors: Ulbricht
authors: Katja
authors: K
authors: Rillich
authors: Sladjana
authors: S
authors: Dukic-Stefanovic
authors: Antje
authors: A
authors: Wurm
authors: Lysann
authors: L
authors: Wagner
authors: Andreas
authors: A
authors: Reichenbach
authors: Peter
authors: P
authors: Wiedemann
authors: Gloria Astrid
authors: GA
authors: Limb
authors: Andreas
authors: A
authors: Bringmann
authors: Leon
authors: L
authors: Kohen
mesh_terms: D000814:Aniline Compounds / Q000032:analysis; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D015870:Gene Expression / Q000528:radiation effects*; D006801:Humans; D007150:Immunohistochemistry; D008027:Light; D055355:Opsins / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D012160:Retina / Q000378:metabolism* / Q000473:pathology / Q000528:radiation effects; D012174:Retinitis Pigmentosa / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D014966:Xanthenes / Q000032:analysis
chemical_list: D000814:Aniline Compounds; C409648:Fluo 4; D055355:Opsins; D012333:RNA, Messenger; D014966:Xanthenes; D002118:Calcium