Driscoll H K, Adkins C D, Chertow T E, Cordle M B, Matthews K A, Chertow B S
Medical Service, VA Medical Center, Huntington, West Virginia, USA.
Pancreas. 1997 Jul;15(1):69-77.
Retinol or retinoic acid is required for insulin release. Retinoids increase transglutaminase activity, and transglutaminase has been implicated in islet insulin release. To examine whether transglutaminase could mediate effects of retinoids on insulin secretion, we measured (i) transglutaminase activity in islets from rats deficient in vitamin A or repleted with retinol or retinoic acid, (ii) transglutaminase activity in RINm5F and INS-1 insulin-secreting cells cultured in retinol or retinoic acid, (iii) mRNA for transglutaminase in RINm5F and INS-1 cells, and (iv) insulin secretion from INS-1 cells in response to retinoic acid. Islets from rats repleted with retinol or retinoic acid showed more than twice the transglutaminase activity of islets from vitamin A deficient rats. Retinoic acid increased RINm5F cells and INS-1 cell transglutaminase activity. Retinol did not increase transglutaminase activity. Transglutaminase mRNA was detected in INS-1 cells but not in RINm5F cells. Retinoic acid increased insulin secretion from INS-1 cells as observed previously in RINm5F cells. In conclusion, retinoic acid increases transglutaminase activity in both rat islets and two insulin-secreting from INS-1 cells. Transglutaminase is a candidate for mediating retinoid-induced changes in insulin secretion.
胰岛素释放需要视黄醇或视黄酸。类视黄醇可增加转谷氨酰胺酶的活性，并且转谷氨酰胺酶与胰岛胰岛素释放有关。为了研究转谷氨酰胺酶是否能介导类视黄醇对胰岛素分泌的影响，我们进行了以下测定：（i）检测维生素A缺乏或补充视黄醇或视黄酸的大鼠胰岛中的转谷氨酰胺酶活性；（ii）检测在视黄醇或视黄酸中培养的RINm5F和INS-1胰岛素分泌细胞中的转谷氨酰胺酶活性；（iii）检测RINm5F和INS-1细胞中转谷氨酰胺酶的mRNA；（iv）检测INS-1细胞对视黄酸的胰岛素分泌反应。补充视黄醇或视黄酸的大鼠的胰岛，其转谷氨酰胺酶活性是维生素A缺乏大鼠胰岛的两倍以上。视黄酸可增加RINm5F细胞和INS-1细胞的转谷氨酰胺酶活性。视黄醇不会增加转谷氨酰胺酶活性。在INS-1细胞中检测到了转谷氨酰胺酶mRNA，但在RINm5F细胞中未检测到。视黄酸可增加INS-1细胞的胰岛素分泌，这与之前在RINm5F细胞中观察到的结果一致。总之，视黄酸可增加大鼠胰岛和INS-1细胞这两种胰岛素分泌细胞中的转谷氨酰胺酶活性。转谷氨酰胺酶是介导类视黄醇诱导的胰岛素分泌变化的一个候选因子。
