title: Degeneration of retinal on bipolar cells induced by serum including autoantibody against TRPM1 in mouse model of paraneoplastic retinopathy.
abstract: The paraneoplastic retinopathies (PRs) are a group of eye diseases characterized by a sudden and progressive dysfunction of the retina caused by an antibody against a protein in a neoplasm. Evidence has been obtained that the transient receptor potential melastatin 1 (TRPM1) protein was one of the antigens for the autoantibody against the ON bipolar cells in PR patients. However, it has not been determined how the autoantibody causes the dysfunction of the ON bipolar cells. We hypothesized that the antibody against TRPM1 in the serum of patients with PR causes a degeneration of retinal ON bipolar cells. To test this hypothesis, we injected the serum from the PR patient, previously shown to contain anti-TRPM1 antibodies by westerblot, intravitreally into mice and examined the effects on the retina. We found that the electroretinograms (ERGs) of the mice were altered acutely after the injection, and the shape of the ERGs resembled that of the patient with PR. Immunohistochemical analysis of the eyes injected with the serum showed immunoreactivity against bipolar cells only in wild-type animals and not in TRPM1 knockout mice,consistent with the serum containing anti-TRPM1 antibodies. Histology also showed that some of the bipolar cells were apoptotic by 5 hours after the injection in wild type mice, but no bipolar cell death was found in TRPM1 knockout mice, . At 3 months, the inner nuclear layer was thinner and the amplitudes of the ERGs were still reduced. These results indicate that the serum of a patient with PR contained an antibody against TRPM1 caused an acute death of retinal ON bipolar cells of mice.
authors.affiliation: Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Ueno
authors.forename: Koji M
authors.initials: KM
authors.lastname: Nishiguchi
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Tanioka
authors.forename: Atsushi
authors.initials: A
authors.lastname: Enomoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamanouchi
authors.forename: Mineo
authors.initials: M
authors.lastname: Kondo
authors.forename: Testuhiro R
authors.initials: TR
authors.lastname: Yasuma
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Yasuda
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Kuno
authors.forename: Masahide
authors.initials: M
authors.lastname: Takahashi
authors.forename: Hiroko
authors.initials: H
authors.lastname: Terasaki
mesh_terms: D000818:Animals; D001323:Autoantibodies / Q000276:immunology*; D004596:Electroretinography; D051379:Mice; D051245:Retinal Bipolar Cells / Q000473:pathology*; D012164:Retinal Diseases / Q000276:immunology / Q000473:pathology*; D050053:TRPM Cation Channels / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D050053:TRPM Cation Channels