Tomohiro M, Aida Y, Inomata M, Ito Y, Mizuno A, Sakuma S
Pharmacia and Upjohn, Tsukuba Research Laboratories, Ibaraki, Japan.
Jpn J Ophthalmol. 1997 May-Jun;41(3):121-9. doi: 10.1016/s0021-5155(97)00029-4.
The UPL (Upjohn Pharmaceutical Limited) rat is a dominant hereditary cataract model that develops early-onset cataracts (E-type) in rats homozygous for the trait, and late-onset cataracts (L-type) in heterozygous rats. Using antibodies specific to the calpain-proteolyzed forms of alpha-crystallin, we determined their immunohistochemical localization of the L- and E-rat lenses. Immunoreactivity indicating the proteolyzed forms was detected and found restricted to degenerated lens fibers of the mature stage of the L-rat cataract. Lenses from E-rats, which have abnormally elongated lens fibers during the fetal period, had proteolyzed alpha-crystallin forms at 1 week of age. The results of this present study indicate that calpain-mediated proteolysis of alpha-crystallin occurred in the UPL rat lenses during cataract formation and that calpain may be an important factor in the development of complete lens opacification.
优普强制药有限公司（UPL）大鼠是一种显性遗传性白内障模型，该模型中，纯合子大鼠会出现早发性白内障（E型），杂合子大鼠会出现迟发性白内障（L型）。我们使用针对钙蛋白酶水解形式的α-晶状体蛋白的特异性抗体，确定了它们在L型和E型大鼠晶状体中的免疫组织化学定位。检测到了表明水解形式的免疫反应性，且发现其局限于L型大鼠白内障成熟期的变性晶状体纤维。E型大鼠的晶状体在胎儿期晶状体纤维异常伸长，在1周龄时就出现了水解形式的α-晶状体蛋白。本研究结果表明，在白内障形成过程中，UPL大鼠晶状体中发生了钙蛋白酶介导的α-晶状体蛋白水解，并且钙蛋白酶可能是晶状体完全浑浊发展的一个重要因素。
