Glial cell-mediated spread of retinal degeneration during detachment: a hypothesis based upon studies in rabbits.
In human subjects with peripheral retinal detachments, visual deficits are not restricted to the detached retina but are also present in the non-detached tissue. Based upon studies on a rabbit model of rhegmatogenous retinal detachment, we propose a glial cell-mediated mechanism of spread of retinal degeneration into non-detached retinal areas which may also have importance for the understanding of alterations in the human retina. Both detached and attached portions of the rabbit retina display photoreceptor cell degeneration and cystic degeneration of the innermost layers. An inverse mode of photoreceptor cell degeneration in the attached tissue suggests a disturbed support of the photoreceptor cells by Müller cells which show various indications of gliosis (increased expression of intermediate filaments, cell hypertrophy, decreased plasma membrane K(+) conductance, increased Ca(2+) responsiveness to purinergic stimulation) in both detached and attached tissues. We propose that gliotic alterations of Müller cells contribute to the degeneration of the attached retina, via disturbance of glial homeostasis mechanisms. A down-regulation of the K(+) conductance of Müller cells may prevent effective retinal K(+) and water clearance, and may favor photoreceptor cell degeneration and edema development.
Francke
Mike
M
Paul Flechsig Institute of Brain Research, University of Leipzig, D-04109 Leipzig, Germany.
Faude
Frank
F
Pannicke
Thomas
T
Uckermann
Ortrud
O
Weick
Michael
M
Wolburg
Hartwig
H
Wiedemann
Peter
P
Reichenbach
Andreas
A
Uhlmann
Susann
S
Bringmann
Andreas
A
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism; D016923:Cell Death / Q000502:physiology; D003560:Cysts / Q000473:pathology; D004487:Edema / Q000473:pathology / Q000503:physiopathology; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D006801:Humans; D023421:Models, Animal; D009457:Neuroglia / Q000502:physiology*; D010786:Photoreceptor Cells / Q000473:pathology / Q000503:physiopathology; D011188:Potassium / Q000378:metabolism; D015221:Potassium Channels / Q000378:metabolism; D011817:Rabbits; D018048:Receptors, Purinergic P2 / Q000378:metabolism; D012160:Retina / Q000473:pathology / Q000503:physiopathology; D012162:Retinal Degeneration / Q000473:pathology / Q000503:physiopathology*; D012163:Retinal Detachment / Q000473:pathology / Q000503:physiopathology*; D014786:Vision Disorders / Q000209:etiology / Q000503:physiopathology
D005904:Glial Fibrillary Acidic Protein; D015221:Potassium Channels; D018048:Receptors, Purinergic P2; D000255:Adenosine Triphosphate; D011188:Potassium; D002118:Calcium