Endocrine Abstracts

Introduction: 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) has been associated with several human metabolic disorders and is converted from inactive 11-keto form to glucocorticoid (GC or cortisol). GC overproduction or hypercortisolism is a major diagnostic factor of Cushing syndrome and Anorexia. GCs regulate carbohydrate, fat, and protein metabolism.

Materials and methods: Previously we established porcine fibroblasts overexpressing 11β-HSD1. Based on these, transgenic piglets overexpressing 11β-HSD1 were born through somatic cell nuclear transfer (SCNT) and re-cloning methods. Transgenic piglets were identified by PCR methods using specific primers for the targeting cassettes from the genomic DNA of piglets. HepG2 cell line overproducing 11β-HSD1 (11β-HSD1-HepG2) was established for in vitro model. In vivo porcine and in vitro hepatic models were analyzed by real-time PCR, immunohistochemistry and Western blotting methods.

Results: Six live piglets were born. Integration of target gene into the genomic DNA was confirmed from all of them. Excessive expression of 11β-HSD1 induced up-regulation of gluconeogenesis (G6PT, G6Pase, PEPCK and etc.) and lipogenesis related genes (FASN, ACC, and SCD) in in vivo and in vitro models. To compensate for energy loss by anabolism, it stimulates AMPK and SIRT signaling, which controls energy balance and mitochondrial biogenesis.

Conclusions: These results suggest that the overproduction of 11β-HSD1 induce activation of complementary energy gaining processes through mitochondrial respiration. Our in vivo and in vitro models will be useful for further study and potential application in metabolic diseases.