Role of Notch signaling pathway in treatment of intrauterine adhesions through human amniotic mesenchymal stem cells transplantation

Abstract

Objective To explore the role of Notch signaling pathway in the transplantation of human amniotic mesenchymal stem cells (hAMSCs) for treatment of intrauterine adhesions (IUA). Methods In vitro experiments: hAMSCs were isolated from human amnion obtained from term cesarean section, and then induced and identified. Then the cells were divided into 3 groups: blank control group (hAMSCs only), AdRFP group (Ad-RFP adenovirus+hAMSCs), and AdR-dnNotch1+hAMSCs group (a recombinant adenovirus expressing the dominant-negative mutant of Notch1+hAMSCs), respectively. Then the mRNA level of Notch1 and the protein level of Notch intracellular domain (NICD) were detected by RT-PCR and Western blotting, respectively. In vivo experiments: 40 Sprague-Dawley (SD) female rats were randomized into Sham group, IUA group, hAMSCs group (IUA animals treated with hAMSCs transplantation), AdR-dnNotch1+hAMSCs group (IUA animals receiving transplantation of AdR-dnNotch1-transfected hAMSCs) (n=10). The number of endometrial glands and the thickness of endometrium in each group were observed by HE staining, and the changes of fibrosis were studied by Masson staining. Immunohistochemical assay was adopted to detect the protein expression of Vimentin, Notch1, NICD, and Hes1 in each group, and that of NICD was further tested by Western blotting. In addition, RT-PCR was used to determine the mRNA level of Hes1. Finally, the changes of fertility in each group were evaluated by co-cage of male and female rats. Results AdR-dnNotch1 successfully inhibited Notch signaling pathway in vitro. In vivo experiments: HE and Masson staining showed that when compared with IUA group, the number of glands was increased, and the thickness of endometrium and the ratio of fibrosis area were decreased in hAMSCs group (P 0.05); Immunohistochemical assay indicated that the level of Vimentin was higher and those of Notch1, NICD and Hes1 were lower in the IUA group than the Sham group (P 0.05); Western blotting and RT-PCR results suggested the Notch signaling pathway was activated in hAMSCs group; The co-cage experiment showed that the number of embryos was increased significantly in hAMSCs group (P 0.05). Conclusion Notch signaling pathway is involved in the regulation of biological functions of hAMSCs, and inhibition of Notch signaling pathway may reduce the effect of hAMSCs transplantation in the treatment of IUA.

Keywords

• intrauterine adhesions
• notch signaling pathway
• human amniotic mesenchymal stem cells
• fertility