Melatonin-pretreated human umbilical cord mesenchymal stem cells improved endometrium regeneration and fertility recovery through macrophage immunomodulation in rats with intrauterine adhesions†.

Intrauterine adhesions (IUA) are a common gynecological problem. Stem cell therapy has been widely used in the treatment of IUA. However, due to the complex and harsh microenvironment of the uterine cavity, the effectiveness of such therapy is greatly inhibited. This study aimed to investigate whether melatonin pretreatment enhances the efficacy of human umbilical cord mesenchymal stem cells (HucMSCs) in IUA treatment in rats. First, we explored the effect of melatonin on the biological activity of HucMSCs in vitro through a macrophage co-culture system, Cell Counting Kit 8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU), flow cytometry, immunofluorescence staining, and qRT-PCR. Subsequently, we established the IUA rat model and tracked the distribution of HucMSCs in this model. In addition, we observed the number of M1 and M2 macrophages through immunofluorescence staining and detected the levels of inflammatory cytokines. Four weeks after cell transplantation, HE, Masson, and immunohistochemical staining were performed. In vitro experiments showed that melatonin pretreatment of HucMSCs promoted proliferation, reduced apoptosis, up-regulated the stemness gene, and regulated macrophage polarization. In vivo, melatonin pretreatment caused more HucMSCs to remain in the uterine cavity. Melatonin-pretreated HucMSCs recruited more macrophages, regulated macrophage polarization, and reduced inflammation. Melatonin-pretreated HucMSCs relieved fibrosis, increased endometrium thickness, and up-regulated CD34, vimentin, proliferating cell nuclear antigen (PCNA), and alpha small muscle antigen (α-SMA) expression. Fertility tests showed that melatonin-pretreated HucMSCs increased the number of embryos. In summary, pretreatment with melatonin was beneficial for HucMSC treatment because it enhanced the cell's ability to recruit macrophages and regulate macrophage polarization, which led to the regeneration of the endometrium and improved pregnancy outcomes.

Aquaporin 9 causes recurrent spontaneous abortion by inhibiting trophoblast cell epithelial-mesenchymal transformation and invasion through the PI3K/AKT pathway†.

BACKGROUND: Invasion of the endometrium by trophoblast cells is a key event during pregnancy, although the underlying mechanism remains unclear. Aquaporin 9 (AQP 9) is expressed in many eukaryotes and is associated with cell invasion. The objective of this study was to evaluate the significance of AQP9 in recurrent spontaneous abortion. METHODS: We screened the GSE22490 dataset and further differentiated aquaporin 9 expression in villi. AQP9 was evaluated as one of the key factors in abortion by injecting AQP9 overexpressed plasmid into the uterus of CD1 mice. Trophoblast cells were transfected with AQP9-overexpressing plasmid or siAQP9 to measure cell proliferation, migration, invasion, and apoptosis. Western blot was used to measure changes in the expression of invasion, epithelial-mesenchymal transformation process, and PI3K/AKT pathway. Finally, the role of AQP9 in PI3K/AKT signaling pathway was determined using the PI3K/AKT inhibitor, LY294002, and activator, 740Y-P. RESULTS: AQP9 is highly expressed in recurrent spontaneous abortion villus. Intrauterine injections of AQP9-overexpressing plasmid into CD1 mice resulted in atrophy and blackness of the gestational sac and increased the absorption rate, it is the causative factor of abortion. AQP9 upregulation inhibited the proliferation, invasion, migration, and epithelial-mesenchymal transformation process in vitro of trophoblast cells and increased cell apoptosis. The opposite result was observed after silencing AQP9. AQP9 overexpression also inhibited the PI3K/AKT pathway. LY294002 and 740Y-P partially recovered AQP9-induced trophoblast invasion and migration via the PI3K/AKT pathway. CONCLUSIONS: AQP9 reduces the invasive ability of trophoblast cells by regulating PI3K/AKT signaling pathway, participating in recurrent spontaneous abortion.

Talin1 regulates glucose metabolism and endometrial receptivity via GLUT-4 in patients with polycystic ovary syndrome and insulin resistance.

Objectives: Talin1 is a cytoskeletal protein and is localized between cells and the extracellular matrix. This study aimed to investigate the mechanism by which Talin1 affects glucose metabolism and endometrial receptivity via glucose transporter proteins-4 (GLUT-4) in patients with polycystic ovary syndrome (PCOS) and insulin resistance (IR). Methods: We examined the expression of Talin1 and GLUT4 in the receptive endometrium of PCOS-IR and control patients. GLUT4 expression was examined after silencing and overexpression of Talin1 in Ishikawa cells. We validated the interaction between Talin1 and GLUT-4 proteins using a co-immunoprecipitation (Co-IP) assay. After successfully establishing the C57BL/6j mouse model of PCOS-IR, the expression of Talin1 and GLUT-4 were examined in PCOS-IR and control mice. The effect of Talin1 on embryo implantation and the number of live births in mice were examined. Results: Our study found low expression of Talin1 and GLUT-4 in the receptive endometrium of PCOS-IR patients compared to that in control patients (p < 0.01). The level of GLUT-4 expression decreased after silencing Talin1 in Ishikawa cells and increased after overexpression of Talin1. Co-IP results showed that Talin1 interacts with GLUT-4 protein. We successfully established a PCOS-IR C57BL/6j mouse model and found that Talin1 and GLUT-4 expression in the receptive endometrium of PCOS-IR mice were lower than that in control mice (p < 0.05). In vivo experiments confirmed that the knockdown of Talin1 affects embryo implantation (p < 0.05) and live birth rate in mice (p < 0.01). Conclusions: Talin1 and GLUT-4 expression were decreased in the endometrium of PCOS-IR patients, and Talin1 may affect glucose metabolism and endometrial receptivity through GLUT4.

Progranulin promotes proliferation, migration and invasion via the PI3K/Akt signalling pathway in a model of endometriosis.

RESEARCH QUESTION: What are the levels of progranulin (PGRN) expression in primary endometrial stromal cells (ESC) and endometrial tissue in patients with endometriosis (EMS)? What is the role and mechanism of action of PGRN in EMS? DESIGN: Endometrial tissue was collected from 30 patients, 15 with EMS (EMS group) and 15 without EMS (non-EMS group). PGRN expression in endometrial tissue and ESC was analysed by immunohistochemistry, immunofluorescence, western blotting and quantitative reverse transcription polymerase chain reaction. PGRN overexpression and silencing ESC were established with lentivirus to detect the effect on proliferation, invasion and migration. The relationship between PGRN and the phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) signalling pathway was verified by western blotting. A rescue assay was performed with PI3K inhibitor treatment. RESULTS: The PGRN expression was significantly higher in EMS samples. PGRN up-regulation promoted proliferation (P = 0.007), migration (P = 0.002) and invasion (P < 0.001) of eutopic endometrial stromal cells (EUESC). The ratio of p-AKT/AKT was higher in the overexpression PGRN (ovPGRN) group than in the overexpression-NC (ovNC) group (P = 0.004). Silencing PGRN produced the opposite results, and LY2940002 addition reversed the effect of PGRN up-regulation on the proliferation, invasion and migration of EUESC. CONCLUSIONS: PGRN might promote the proliferation, invasion and migration of EUESC via the PI3K/Akt signalling pathway. These preliminary in-vitro findings may present a new perspective and inspire further study of the mechanism of EMS.

The diagnostic value of serum YKL-40 in endometrial cancer: a meta-analysis.

BACKGROUND: Serum YKL-40 is a promising non-invasive biomarker for the early diagnosis of endometrial cancer (EC), but its value is disputed. OBJECTIVE: To investigate the serum YKL-40 in the early diagnostic value of EC. METHODS: Databases were systematically searched again before April 2021 and 14 studies were finally included in this meta-analysis. Pooled sensitivity, specificity, negative likelihood ratio (NLR), positive likelihood ratio (PLR), diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curve analyses were assessed. This meta-analysis investigated the source of heterogeneity using sensitivity analysis, subgroup analysis, and meta-regression. RESULTS: Databases were systematically searched again before April 2021 and 14 studies were finally included in this meta-analysis. First, the SROC curve presented an area under the curve (AUC) of 0.853 (SE = 0.0213) for YKL-40 alone and an AUC of 0.946 (SE = 0.0268) for YKL-40 combined with other biomarkers. Second, diagnostic types might be related to the diagnostic accuracy and is a significant source of heterogeneity (P = 0.035). CONCLUSION: Serum YKL-40 helped diagnose EC, and its combination with other biomarkers was better than itself alone.

Activated Human Umbilical Cord Blood Platelet-Rich Plasma Enhances the Beneficial Effects of Human Umbilical Cord Mesenchymal Stem Cells in Chemotherapy-Induced POF Rats.

Saving the ovarian function of premature ovarian failure (POF) patients undergoing chemotherapy is an important problem in the field of reproductive medicine. At present, human umbilical cord mesenchymal stem cells (HucMSCs) have been used in the treatment of POF, but the effect is still not optimal. The purpose of this study was to determine whether human umbilical cord blood platelet-rich plasma (ucPRP) enhances the beneficial effects of HucMSCs in the treatment of POF. First, we observed the effects of changes in the biological activity of ucPRP on HucMSCs in vitro. Subsequently, we tracked the distribution and function of the HucMSCs in POF rats, and the rats' estrus cycle and serum sex hormones, follicular development, ovarian angiogenesis, ovarian granulosa cell proliferation, and apoptosis were assessed. The results of the study showed that the addition of ucPRP in vitro accelerates proliferation and reduces apoptosis of the HucMSCs while upregulating the stemness gene of the HucMSCs. The combined transplantation of HucMSCs and ucPRP resulted in more stem cells being retained in the ovaries of POF rats, the estrus cycle of the POF rats being restored, the levels of serum E2, AMH, and FSH improving, and damaged follicles beginning to grow. Finally, we confirmed that the potential mechanism of the combination of HucMSCs and ucPRP to rescue the ovarian function of POF rats is to promote ovarian angiogenesis and to promote the proliferation and reduce the apoptosis of ovarian granulosa cells. The upregulation of AMH and FHSR expression and the downregulation of caspase-3 expression in granulosa cells are potential mechanisms for the recovery of ovarian function. Our research results suggest that the combined application of HucMSCs and ucPRP is a safe and efficient transplantation program for the treatment of POF, thus providing a reliable experimental basis for the clinical application of stem cell therapy in POF.