Abstract Cell therapy has an advantage of compensating hormone in response to physiological stimuli. We have previously shown that mouse mesenchymal stem cells (MSCs) were transformed into steroidogenic cells by forced expression of NR5A1 (a master regulator of steroidogenesis, also known as SF-1/Ad4BP) and that the syngeneic implantation of NR5A1-induced steroidogenic cells extended survival of bilateral adrenoectomised (bAdx) mice. However, ACTH receptor is not induced by NR5A1 in mouse MSCs, and ACTH responsiveness was not detected in recipient mice. In contrast to mice, in human MSCs, ACTH receptor is induced by NR5A1 and ACTH enhances steroid production in NR5A1 induced-steroidogenic cells in vitro studies. In the present study, we implanted human ADSCs-derived steroidogenic cells into immunodeficient mice with adrenal insufficiency. Human adipose tissue-derived stem cells (ADSCs) were inoculated with recombinant adenovirus containing human NR5A1 or LacZ cDNA (MOI=50) and cultured for 7 days. NR5A1 induced-steroidogenic cells secreted both adrenal and gonadal steroids and responded to ACTH. Before xenotransplantation studies, adrenal glands of SCID/Beige mice were surgically removed and implanted into under capsule of the kidney. bAdx mice were dead within 9 days (N=11), bAdx mice (N=12) transplanted with adrenal glands survived to the endpoint of 30 days, and died within 9 days after removal of the kidney containing the graft. We next implanted NR5A1-induced steroidogenic cells or control cells into bAdx mice. The overall survival rate (endpoint of 30 days) of NR5A1 implanted mice was 16.7%, (N=12) while control cell implanted mice died within 13 days (N=10). Median survival time of bAdx mice implanted with NR5A1 induced-steroidogenic cells and control ADSCs was 16. 0 and 11. 0 days, respectively (log-rank test, p < 0. 0001). In the NR5A1 induced-steroidogenic cells implanted mice, serum aldosterone was undetectable, whereas serum corticosterone and cortisol were detectable. Although we performed ACTH loading test on bAdx mice implanted with NR5A1-induced steroidogenic cells, no ACTH responsiveness was detected. The expression of Pomc mRNA in the pituitary gland was increased by bAdx, whereas this increase was not suppressed by implantation of steroid-producing cells (N=3), suggesting that the amount of steroids in the graft complemented survival but was insufficient for negative feedback. These results indicate that human ADSCs are transformed into steroidogenic cells by NR5A1 and are responsive to ACTH in vitro but not in vivo. Xenotransplantation of the induced steroidogenic cells into immunodeficient bAdx mice prolonged the survival, which was supported by the significant detection of basal serum corticosterone and cortisol levels. In particular, serum cortisol indicated hormone secretion from the grafts, suggesting that human ADSCs may also be useful as a regenerative source of steroid-producing cells. Presentation: No date and time listed
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