title: PEDF counteracts DL-α-aminoadipate toxicity and rescues gliotoxic damages in RPE-free chicken retinal explants.
abstract: Gliotoxic responses complicate human eye diseases, the causes of which often remain obscure. Here, we activated Müller cells (MCs) by the gliotoxin DL-α-aminoadipate (AAA) and assayed possible protective effects by pigment epithelium-derived factor (PEDF) in RPE-free retinal explants of the E6 chick embryo. These models are suited to analyze gliotoxic reactions in vitro, since the avian retina contains only Müller cells (MCs) as glial components, and the RPE-free explants are devoid of a major PEDF source. ChAT- and AChE-immunohistochemistry (IHC) revealed that AAA treatment disrupted the differentiation of cholinergic amacrine cells in the inner plexiform layer. At the applied concentration of 1 mM AAA, apoptosis of MCs was slightly increased, as shown by TUNEL and caspase-3 activity assays. Concomitantly, cell-free gaps emerged in the middle of the retina, where MCs were swollen and amassed glutamine synthetase (shown by GS and Vimentin IHC). AAA treatment strongly activated MCs, as shown by GFAP IHC, and by an increase of stress-related catalase activity. Remarkably, nearly all effects of AAA on MCs were effectively counter-balanced by 50 ng/ml PEDF co-treatment, as also shown by RT-PCR. These findings suggest that supplementation with PEDF can protect the retina against gliotoxic attacks. Further studies should establish whether PEDF similarly protects a gliotoxic human retina.
authors: Technische Universität Darmstadt, Entwicklungsbiologie und Neurogenetik, Schnittspahnstrasse 13, D-64287 Darmstadt, Germany.
authors: Gopenath
authors: G
authors: Thangaraj
authors: Technische Universität Darmstadt, Entwicklungsbiologie und Neurogenetik, Schnittspahnstrasse 13, D-64287 Darmstadt, Germany.
authors: Jeanette
authors: J
authors: Christophel
authors: Technische Universität Darmstadt, Entwicklungsbiologie und Neurogenetik, Schnittspahnstrasse 13, D-64287 Darmstadt, Germany.
authors: Gesine
authors: G
authors: Bachmann
authors: Technische Universität Darmstadt, Entwicklungsbiologie und Neurogenetik, Schnittspahnstrasse 13, D-64287 Darmstadt, Germany.
authors: Alexander
authors: A
authors: Greif
authors: Technische Universität Darmstadt, Entwicklungsbiologie und Neurogenetik, Schnittspahnstrasse 13, D-64287 Darmstadt, Germany. Electronic address: layer@bio.tu-darmstadt.de.
authors: Paul G
authors: PG
authors: Layer
mesh_terms: D015074:2-Aminoadipic Acid / Q000633:toxicity*; D000109:Acetylcholine / Q000378:metabolism; D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000378:metabolism; D002642:Chick Embryo; D063928:Ependymoglial Cells / Q000187:drug effects* / Q000378:metabolism; D018691:Excitatory Amino Acid Antagonists / Q000633:toxicity*; D005136:Eye Proteins / Q000494:pharmacology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D005911:Gliosis / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009924:Organ Culture Techniques; D018384:Oxidative Stress; D012160:Retina / Q000187:drug effects / Q000196:embryology*; D055213:Retinal Pigment Epithelium / Q000166:cytology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015843:Serpins / Q000494:pharmacology*; D000099174:Pigment Epithelium-Derived Factor
chemical_list: D015074:2-Aminoadipic Acid; D000109:Acetylcholine; D000110:Acetylcholinesterase; D053148:Caspase 3; D018691:Excitatory Amino Acid Antagonists; D005136:Eye Proteins; D005904:Glial Fibrillary Acidic Protein; D009414:Nerve Growth Factors; D015843:Serpins; D000099174:Pigment Epithelium-Derived Factor
keywords: Gliosis; IPL subband; Inner plexiform layer; Müller glial cell; Photoreceptor; Radial glia