Comparing The Characteristics Of Different ECMs And Their Effects On Endometrial Regeneration In A Rat Uterine Injury Model

Background:The decellularized extracellular matrices(d-ECMs)currently utilized to repair endometrial injuries are derived from three tissue sources,the endometrium(dE-ECM),placental amniotic membrane(dA-ECM),and urinary(dU-ECM).Notably,the structures of dU-ECM and dE-ECM are similar.These d-ECMs are derived from different tissues,and their specific roles in endometrial injury repair remain unclear.Objective:This study aimed to analyse the characteristics of the tissue microstructures and compositions to confirm specific differences among the three ECM types.And the importance of dECM for maintaining the secretory function of endometrial stromal cells;To clarify the role of ECM components in endometrial injury repair,and explore the potential mechanism of endometrial repair from the perspective of ECM.Methods:1.HE and electron microscopy were used to compare the tissue microstructure,ELISA was used to detect growth factors,collagen and other components,and the specific structural characteristics of the three ECM were analyzed.2.Three kinds of dECM were used to culture endometrium-derived stromal cells in vitro.Edu was used to detect cell proliferation,and RT-PCR was used to detect the difference of growth factor secretion function of stromal cells under estrogen stimulation.3.And using a rat model of endometrial injury,the effects of all the matrices after implantation in vivo on the promotion of endometrial regeneration were analysed.Result:1.dE-ECM and dU-ECM are highly similar in structure,and the structure is looser than DA-ECM.The structures of three kinds of D-ECM are similar under electron microscope.The dE-ECM group has higher VEGF,HGF and bFGF mRNA than other groups.2.After decellularization,dE-ECM had more residual active factors than the other two ECM types,while dA-ECM had significantly less DNA,α-Gal antigen components and extracellular matrix components than the other two groups.Although the three ECMs had no effect on the proliferation of stromal cells in vitro,dA-ECM may have increased the sensitivity of stromal cells to oestradiol(E2)responses.3.In vivo experiments confirmed the promotional effect of dA-ECM on endometrial regeneration.For example,the endometrial thickness,collagen deposition,endometrial tissue regeneration,vascular regeneration and pregnancy outcomes were significantly better in this group than in the other two groups.Conclusion:1.When selecting a d-ECM for the treatment of endometrial injury,dE-ECM,which has the strongest tissue specificity,is not the preferred choice.These findings might be associated with the excellent immune tolerance of dA-ECM.2.Controlling the inflammatory responses in local lesions at the early stage may be a prerequisite for ECMs to exert their functions.