The therapeutic effect of stem cell‐derived exosomes in the treatment of chronic endometritis as assessed by histopathological, Doppler and hormonal expression in Arabian mares

Abstract

SummaryBackgroundBone‐derived exosomes are considered nano‐sized extracellular vesicles secreted by the bone marrow stromal cells.ObjectivesThis study used exosomes derived from bone marrow mesenchymal stem cells to treat chronic endometritis in Arabian mares with follow‐up alterations in haemodynamics, hormonal and histopathological expressions.Methods and study designFourteen (n = 14) Arabian mares (aged 13–15 years old) were equally divided into the control group and an endometritis group (chronic type). Exosomes were infused twice 21 days apart at the first and second ovulations. Follow‐up was done ultrasonographically, and samples were taken for histopathology. Blood samples were taken to estimate hormonal levels.ResultsUterine biopsy samples before treatment showed a marked degree of degeneration, while the second exosomal treatment showed regression of fibrous tissue and restoration of healthy endometrial glands with normal epithelium. Uterine body and horns thickness/mm were decreased after treatment at day 0 of the 3rd ovulation compared to day −1 before treatment, the uterine body‐coloured area and total uterine coloured areas/pixels were elevated (p < 0.05) at day 0 of the 3rd ovulation compared to day −1 before treatment. Uterine artery blood parameters (pulsatility index, resistance index, peak systolic and end‐diastolic points) did not change before, during and after treatment, but the blood flow rate was elevated (p < 0.05) on day 0 of the 3rd ovulation compared to day −1 before treatment. Oestradiol level was decreased (p < 0.05), while progesterone level was increased (p < 0.05) on day 0 of the 3rd ovulation compared to day −1 before treatment.ConclusionTwo intrauterine administrations of exosomes restored the normal endometrial appearance after chronic endometritis resulting in the elevation of the conception rate in infertile mares.