Purchase this article with an account.
P. Ahuja, A.R. Caffe, S. Ahuja, P. Ekström, T. van Veen; Cellular Distribution and Differences in levels of TIMP–1 and TIMP–2 in rd1/rd1 and +/+ mice. . Invest. Ophthalmol. Vis. Sci. 2004;45(13):4010.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: Extensive studies have established a critical role for extracellular proteases in normal and pathological brain processes, but little of this knowledge extends to the retina. Scattered information about matrix metalloproteases and their inhibitors (TIMP) on the retina suggest involvement of these molecules in retinal degeneration, but a comprehensive and consistent pattern of their sources and variation during the retinal degenerative process is missing. For this reason we are conducting a detailed investigation on the cellular sources and levels of TIMPs during normal retinal development and degeneration in the rd1/rd1 mouse. Methods: Eyes were collected from congenic rd1/rd1 and +/+ at different ages in development i.e. postnatal day (PN) 2, PN7, PN14, PN21 and PN28. The eyes were frozen in dry ice after enucleation then sectioned on cryostat and fixed shortly in mixture of methanol and acetic acid (3:1) before staining with antibodies against TIMP–1 and TIMP–2. To determine levels, retinas with attached RPE were dissected out, homogenized and centrifuged. TIMP–1 and TIMP–2 levels were measured in the lysate using commercial sandwich ELISA kits. Results: Preliminary results show that TIMP–1 and TIMP–2 immunostaining is present in both the rd1/rd1 and +/+ in the inner segments and outer limiting membrane (OLM) in all the age groups except that in the rd1/rd1 at after PN14 the staining is present only in the OLM as the inner segments have degenerated by this time. ELISA shows that the levels of TIMP–1 in rd1/rd1 retina was always higher than those in corresponding extracts of +/+ retinas and decreased with increasing age of retina of both the genotypes. The level of TIMP–2 in PN2 +/+ and PN7 rd1/rd1 retina was respectively higher than that in PN2 rd1/rd1 and PN7 +/+ retinas, whereas those at other time points were similar in both genotypes. Conclusions: We report here that in rd1/rd1 retina TIMP–1 levels are always higher than corresponding control, but levels decrease during maturation. Since in a companion abstract we are reporting increasing secretion of MMP–9 by rd1/rd1 retinal explants combined results suggest higher proportions of uninhibited MMP–9 activities in rd1/rd1 retina. This condition may contribute to the retinal degenerative process. The difference in TIMP–2 levels between rd1/rd1 and +/+ retina occur during the first postnatal week. The significance of this phenomenon is unclear at present.
This PDF is available to Subscribers Only