Contribution of ubiquitous calpains to cataractogenesis in the spontaneous diabetic WBN/Kob rat

Kanako Sakamoto-Mizutani, Chiho Fukiage, Yoshiyuki Tamada, Mitsuyoshi Azuma, Thomas R. Shearer

Research output: Contribution to journalArticle

22 Scopus citations

Abstract

To determine the involvement of calpains in human cataractogenesis, studies in aged animal models are needed. Aged, male WBN/Kob rats spontaneously develop cataract along with severe, persistent diabetes with hyperglycemia and nephropathy. The purpose of present experiments was to provide a biochemical mechanism for the involvement of ubiquitous calpains in cataractogenesis in WBN/Kob rats. Serum and urinary glucose were measured to confirm diabetes, and cataracts were observed by slit lamp biomicroscopy. Calcium determinations were performed on lens samples from several ages of WBN/Kob and Wistar rats. Casein zymography, immunoblot analysis for α-spectrin, calpain 2, and calpain 10 were performed to detect activation of calpain in lens samples. Serum glucose levels increased and cortical cataract developed in male WBN/Kob rats within 1 year, indicating diabetic cataract. Cataract was accompanied by several presumptive biochemical indicators of calpain activation, including increased calcium, proteolysis of α-spectrin, and decreased caseinolytic activity for calpains suggesting calpain activation followed by autolytic degradation. Activation of ubiquitous calpains may contribute to biochemical mechanism of cataractogenesis in spontaneously diabetic WBN/Kob rats. The WBN/Kob model may be useful for elucidating the roles of calpain 2 and calpain 10 in human cataractogenesis.

Original languageEnglish (US)
Pages (from-to)611-617
Number of pages7
JournalExperimental Eye Research
Volume75
Issue number5
DOIs
StatePublished - Jan 1 2002

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Keywords

  • Calcium
  • Calpain 10
  • Calpain 2
  • Cataract
  • Spontaneous diabetes
  • WBN/Kob rat

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience

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