Regulation of alpha-crystallin gene expression by glucocorticoids in lens epithelial cells

PURPOSE: The purpose of this study was to examine the molecular basis for steroid-induced cataract and the specific aim was to investigate the potential effects of glucocorticoids on modulation of alpha-crystallin gene expression in lens epithelial cells. METHOD: Bovine lens epithelial explants, B-3 human lens epithelial cells, and alphaTN4 mouse lens epithelial cells were incubated in the absence or presence of dexamethasone. At the indicated time point, total cellular RNA was isolated and subjected to RT-PCR and Northern blot analysis to assess mRNA expression of alphaA- and alphaB-crystallin. RESULTS: The mRNA expression of alphaA-crystallin was drastically downregulated by treatment with dexamethasone in bovine, human, and mouse lens epithelial cells. The mRNA level of alphaA-crystallin was also decreased in response to hydrocortisone but not to estrogen. The stability of the alphaA-crystallin mRNA was decreased after dexamethasone treatment. CONCLUSIONS: These results suggest that the alteration of alphaA-crystallin gene expression by glucocorticoids may result in abnomal structure and differentiation of lens epithelial cells on steroid-induced cataract formation.

A Study on Antibody Producing by Intoxication of Cadmium Chloride or Lead Acetate in Rat / 예방의학회지

Among the environmental pollutants, cadmium and lead compounds may impair human health. These compounds may inhibit the biological metabolic function of bum.an body and may furthermore cause the disease directly or indirectly. This study was undertaken to investigate the effects of the immune response by intoxication of cadmium chloride and chloride acetate. Cadmium chloride (8.8 mg/kg, in saline 10 ml) and lead acetate (15 mg/kg, in saline 10 ml) were administered by lntraperitoneal injection. After 3 weeks, the rats were intoxicated with the above chemicals and immunized with sheep RBC. After 4 weeks, the immune response of rat spleen cells was measured by the Jerne's technique. The results were obtained as follows; 1. There was no change in leukocyte counts by the intoxication of cadmium chloride or lead acetate. 2. Cadmium chloride or lead acetate reduced hemoglobin contents for most intoxicated and immunized groups. 3. Hematocrits were decreased by the intoxication of cadmium chloride or lead acetate significantly. 4. It was determined that total protein, A/G (Albumin/Globulin), alpha-, beta- and gamma-globulins in rat serum were not changed. 5. Intoxication by cadmium chloride or lead acetate reduced the number of hemolytic plaque to the sheep RBC in rat spleen cells. Therefore, antibody producing of rat spleen cells was suppressed by the intoxication of cadmium chloride and lead acetate.