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Abstract #8885 Published in IGR 5-2
Protease activated receptor subtype expression in developing eye and adult retina of the rat after optic nerve crush
Rohatgi T; Sedehizade F; Sabel BA; Reiser GJournal of Neuroscience Research 2003; 73: 246-254
Protease activated receptors (PARs), 7 transmembrane domain G protein coupled receptors, are involved in tissue degeneration and repair upon injury. The authors demonstrate the expression of all four PAR subtypes in the postnatal eye and in retina of the adult rat by reverse transcription polymerase chain reaction (RT-PCR). PAR 1 is regulated developmentally in the eye, with a decrease from P1, P9, to P16, while levels for PAR 2, PAR 3, and PAR 4 remain unchanged throughout. In the retina of the adult rat, PAR 1 is highly expressed, while PAR 2 and PAR 3 are moderately expressed, compared to low PAR 4 expression. To elucidate possible roles of PARs after trauma, The authors carried out semi-quantitative RT-PCR analysis of expression of all four PAR subtypes, starting six hours after partial optic nerve crush (ONC) in the adult rat until three weeks after the mild trauma. Levels of PAR mRNA for all four subtypes were upregulated as early as six hours after unilateral ONC, except PAR 3, which showed a delayed upregulation. PAR 1, PAR 3, and PAR 4 mRNA levels returned to almost basal levels at three weeks post-crush, whereas PAR 2 mRNA level was still high by the end of three weeks after crush. Although the lesion was unilateral, PAR mRNA expression in the contralateral, uninjured side was affected to levels almost comparable to those in the injured side. Previous studies have shown an increase in thrombin levels at the site of injury, retinal ganglion cell degeneration by necrosis and apoptosis, and PAR activation as consequences of nerve crush. PAR upregulation because of nerve crush in the mild trauma model could act as an effector of early cell death. Eventual return of receptor mRNA to basal levels is consistent with neuroprotection.
Dr. G. Reiser, Institut fur Neurobiochemie, Otto von Guericke Univ. Magdeburg, Medizinische Fakultat, Leipziger Strasse 44, 39120 Magdeburg, Germany. georg.reiser@medizin.uni magdeburg.de
Classification:
2.13 Retina and retinal nerve fibre layer (Part of: 2 Anatomical structures in glaucoma)
3.5 Molecular biology incl. SiRNA (Part of: 3 Laboratory methods)
5 Experimental glaucoma; animal models
