Mu-Crystallin, New Candidate Protein In Endotoxin-Induced Uveitis

PURPOSE. mu-Crystallin (CRYM) is a major taxon-specific lens protein. The purpose of this study was to investigate the function of CRYM in eyes of mice with endotoxin-induced uveitis (EIU).METHODS. EIU was induced by an injection of a lipopolysaccharide (LPS) into the footpad of male C57BL/6J, CRYM knockout (CRYM-/-), and wild-type (CRYM+/+) mice. The expression of CRYM in the iris-ciliary body (ICB) was investigated by Western blot analyses and real-time RT-PCR at 12 hours and 1, 3, and 5 days after the LPS injection. The number of cells that had infiltrated the anterior chamber (AC) of the CRYM+/+ mice was compared to that in the CRYM-/- mice at 1, 3, 5, and 7 days. The expressions of the mRNA of interleukin (IL)-1 alpha, IL-6, tumor necrosis factor (TNF)-alpha, and granulocyte macrophage- colony stimulating factor (GM-CSF) in the ICB of the two groups of mice were compared.RESULTS. The mRNA of CRYM was upregulated at 12 hours after LPS injection, and CRYM protein increased at 3 days. The number of inflammatory cells in the AC of the CRYM-/- mice was not significantly different on day 1 from that in the CRYM+/+ mice, but was significantly lower (17.9 +/- 1.6 vs. 27.1 +/- 2.4 cells/section) on day 5. Expression of the mRNA of IL-1 alpha and -6 in the CRYM-/- mice was significantly lower than that in the CRYM+/+ mice on day 5.CONCLUSIONS. CRYM plays an important role in the development of the second peak of murine EIU. (Invest Ophthalmol Vis Sci. 2010;51:3554-3559) DOI: 10.1167/iovs.09-3728