Abstract
Purpose::
µ-Crystallin (CRYM) was first identified as a major structural protein of lens. We have previously reported that CRYM was highly expressed in iris-ciliary body (ICB) of endotoxin-induced uveitis(EIU) rats by cDNA microarray analysis. This indicated that CRYM probably had non-crystallin role, like other crystallins. The purpose of this study was to examine a possible role of CRYM in EIU.
Methods::
EIU was induced by a footpad injection of lipopolisaccaride (LPS) in male Lewis rats (6~8 week). The expression level of CRYM expression in the ICB at each time point (3, 6, 12, 24) after LPS injection was studied by real time RT-PCR and Western blot analysis. Immunohistochemical studies were also performed to localize CRYM. Eyes of C57BL/6J (B6) mice and CRYM deficient (CRYM-KO)mice were enucleated on 5 days after LPS injection. Inflammatory cells infiltrated into the anterior chamber (AC) and vitreous cavity were counted on histologic sections of eyes.
Results::
CRYM mRNA was up-regulated in the ICB at 6, 12 hours after LPS injection. CRYM protein up-regulated at 12, 24, 48 hours after LPS injection, and identified in the non-pigment ciliary epithelium. The number (mean ± S. E. M) of inflammatory cells infiltrated into the AC and vitreous body of CRYM-KO mice were significantly less than those of B6 mice (6.1 ± 1.2 , 16.1 ± 1.6 cells/section, respectively).
Conclusions::
CRYM was expressed in the non-pigment ciliary epithelium in EIU. Intraocular inflammation in CRYM-KO mice was milder compared with that in control. These results suggested CRYM might be associated to recurrent of late inflammatory cells or delay inflammation.
Keywords: uveitis-clinical/animal model • crystallins • inflammation