Effect of human umbilical cord mesenchymal stem cells transplantation on nerve fibers of a rat model of endometriosis

Abstract

Background: Endometriosis is a common, benign, oestrogen-dependent, chronic gynaecological disorder associated with pelvic pain and infertility. Some researchers have identified nerve fibers in endometriotic lesions in women with endometriosis. Mesenchymal stem cells (MSCs) have attracted interest for their possible use for both cell and gene therapies because of their capacity for self-renewal and multipotentiality of differentiation. We investigated how human umbilical cord-MSCs (hUC-MSCs) could affect nerve fibers density in endometriosis.

Materials and methods: In this experimental study, hUC-MSCs were isolated from fresh human umbilical cord, characterized by flow cytometry, and then transplanted into surgically induced endometriosis in a rat model. Ectopic endometrial implants were collected four weeks later. The specimens were sectioned and stained immunohistochemically with antibodies against neurofilament (NF), nerve growth factor (NGF), NGF receptor p75 (NGFRp75), tyrosine kinase receptor-A (Trk-A), calcitonin gene-related peptide (CGRP) and substance P (SP) to compare the presence of different types of nerve fibers between the treatment group with the transplantation of hUC-MSCs and the control group without the transplantation of hUC-MSCs.

Results: There were significantly less nerve fibers stained with specific markers we used in the treatment group than in the control group (p<0.05).

Conclusion: MSC from human umbilical cord reduced nerve fiber density in the treatment group with the transplantation of hUC-MSCs.

Keywords: Endometriosis; Immunohistochemistry; Mesenchymal Stem Cells; Nerve Fibers.

Fig.1

HUC-derived MSC-like cells in passaged cultures. Immunophenotype (A) and H&E staining of UC-derived MSC-like cells (B). Osteogenic differentiation as indicated by the formation of mineralized matrix shown by alizarin red staining (C) and alkaline phosphatase expression (D). Adipocytic differentiation was noted by the presence of broadened morphology and formation of lipid vacuoles (E) (positive oil-red O staining). Scale bars=80 μm. hUC; Human umbilical cord, MSCs; Mesenchymal stem cells, H&E; Haematoxylin and eosin and CD; Cluster of differentiation.

Fig.2

Nerve fibers in ectopic endometriotic lesions. A. Nerve fibers stained with NF from the control group without the transplantation of hUC-MSCs. B. Nerve fibers stained with NF from the treatment group with the transplantation of hUC-MSCs. C. Nerve fibers stained with NGF from the control group. D. Nerve fibers stained with NGF from the treatment group. E. Nerve fibers stained with Trk-A from the control group. F. Nerve fibers stained with Trk-A from the treatment group. G. Nerve fibers stained with NGFRp75 from the control group. H. Nerve fibers stained with NGFRp75 from the treatment group. I. Nerve fibers stained with CGRP from the control group. J. Nerve fibers stained with CGRP from the treatment group. K. Nerve fibers stained with SP from the control group. L. Nerve fibers stained with SP from the treatment group. Scale bars represent 50 μm in A-R (magnification ×200). Black arrows represent nerve fibers and yellow arrows represent endometrial glands.