2023, Vol. 27 ›› Issue (1): 8-14

Adipose-derived stem cells overexpressing growth hormone promote proliferation and migration of fibroblasts

Gao Yixuan1, Wang Lingfeng1, Ba Te1, Li Fang2, Cao Shengjun1, Li Junliang1, Zhou Biao1, Chen Qiang1   

Abstract: BACKGROUND: Growth hormone plays an important physiological role in immune regulation, cell proliferation, and protein synthesis. It has been proven that growth hormone can promote the healing of acute and chronic wounds.
OBJECTIVE: To construct adipose-derived stem cell lines overexpressing growth hormone, and to investigate the effect of adipose-derived stem cell lines overexpressing growth hormone on proliferation and migration of fibroblasts and its molecular mechanism.  
METHODS: (1) Adipose-derived stem cells were isolated and identified in vitro. (2) Growth hormone-overexpressing lentivirus was constructed. Adipose-derived stem cells were divided into growth hormone group, empty group, and control group. The above three groups were transfected with growth hormone-overexpressing lentivirus, empty lentivirus, and no infection. (3) The mRNA and protein expression levels of growth hormone and related genes of ERK1/2 pathway in cells and supernatants of each group were detected by RT-qPCR, western blot assay, and ELISA. (4) The effects of growth hormone group and empty group on the migration and proliferation of fibroblasts were detected by the scratch test, Transwell test, and MTS test. The expression of related genes in fibroblasts after co-culture with adipose-derived stem cell lines overexpressing growth hormone was detected by RT-qPCR. (5) After inhibiting adipose-derived stem cell lines overexpressing growth hormone by ERK inhibitor, the expression of above-mentioned genes in fibroblasts was observed after co-culture with ERK inhibitor.
RESULTS AND CONCLUSION: (1) Adipose-derived stem cells were isolated and identified and the adipose-derived stem cell lines overexpressing growth hormone were successfully constructed. (2) The mRNA and protein expression levels of growth hormone in the growth hormone group were significantly higher than those in the empty group and control group (P < 0.01), and growth hormone in the supernatant of the growth hormone group was higher. The expression of ERK1/2 and p-ERK1/2 protein was up-regulated in the growth hormone group. (3) Compared with the empty group, the growth hormone group promoted the migration and proliferation of fibroblasts (P < 0.05). (4) After adipose-derived stem cell lines overexpressing growth hormone were co-cultured with fibroblasts, the expression of matrix metalloproteinase-2 genes in fibroblasts was down-regulated; the expression of type I collagen gene was up-regulated, and the expression of type III collagen gene was not significantly changed. (5) After inhibition of ERK protein in adipose-derived stem cell lines overexpressing growth hormone, the mRNA expression differences of these genes disappeared. (6) The results showed that lentivirus transfection was efficient in constructing adipose-derived stem cell lines overexpressing growth hormone, and the cells could secrete growth hormone continuously and promote the proliferation and migration of fibroblasts, which might be related to the up-regulation of the intracellular ERK1/2 signaling pathway.  
Key words: wound healing, tissue engineering, adipose-derived stem cell, growth hormone, ERK pathway