Metalloproteinases In Traumatic Retinal Detachment

Purpose: Penetrating eye trauma is the leading cause of blindness in the young. Traumatic retinal detachment is one of the most significant factors threatening the prognosis of penetrating eye trauma. Matrix metalloproteinases, a group of proteinases, the main contributors of extra cellular matrix degradation, participate hi the most of the physiological and pathological processes involved in cell migration, proliferation, and matrix remodeling. It is assumed that metalloproteinases play a critical role in wound healing process. This study aims to evaluate the possible roles of gelatinase MMP-2 and MMP-9 in the pathologic processes of traumatic retinal detachment.Methods: To study the relationship between metalloproteinases and traumatic retinal detachment we first devised a rabbit model of traumatic retinal detachment, on which we, using method of gelatin zymography, detected levels of MMP-2 and MMP-9 in vitreous, in the detached and non-detached retinas. We also studied the expression of mRNA of MMP-2 and MMP-9 in the retina by RT-PCR. At last we purified and cultured Muller cells of retina on which we tested MMP-2 and MMP-9 by zymography.Results: Traumatic retinal detachment was successfully induced in the rabbits. Photoreceptors necrosis and sub-retinal gliosis are the main pathological changes of traumatic retinal detachment. MMP-2 exists in the vitreous and retina of both retinal detachment and non-retinal detachment groups. MMP-9 was elevated in vitreous of both groups, but detected only in the detached retina. mRNA of MMP-9 was only detected in the detached retinas, too. Cultured Muller cells from both normal and detached retinas express MMP-2 and MMP-9.Conclusions: MMP-9 was increased in both vitreous and retina of the eyes with traumatic retinal detachment. Expression of mRNA of MMP-2 and MMP-9 in the retina implies that the MMPs detected by zymograph in the retina were secreted by the retina itself. And cultured Muller cells secrete MMP-2 and MMP-9, indicating that the Muller cell may be a candidate of MMP-9 secretion in the retina.