Clinical Efficacy and Safety of Stem Cell-Based Therapy in Treating Asherman Syndrome: A System Review and Meta-Analysis

MeCP2 ubiquitination and sumoylation, in search of a function†

MeCP2 (Methyl CpG binding protein 2) is an intrinsically disordered protein that binds to methylated genome regions. The protein is a critical transcriptional regulator of the brain, and its mutations account for 95% of Rett syndrome (RTT) cases. Early studies of this neurodevelopmental disorder revealed a close connection with dysregulations of the ubiquitin system (UbS), notably as related to UBE3A, a ubiquitin ligase involved in the proteasome-mediated degradation of proteins. MeCP2 undergoes numerous post-translational modifications (PTMs), including ubiquitination and sumoylation, which, in addition to the potential functional outcomes of their monomeric forms in gene regulation and synaptic plasticity, in their polymeric organization, these modifications play a critical role in proteasomal degradation. UbS-mediated proteasomal degradation is crucial in maintaining MeCP2 homeostasis for proper function and is involved in decreasing MeCP2 in some RTT-causing mutations. However, regardless of all these connections to UbS, the molecular details involved in the signaling of MeCP2 for its targeting by the ubiquitin-proteasome system (UPS) and the functional roles of monomeric MeCP2 ubiquitination and sumoylation remain largely unexplored and are the focus of this review.

Unlocking the Potential of Mesenchymal Stem Cells in Gynecology: Where Are We Now?

Stem cells, with their remarkable capacity for differentiation into diverse cell types, are vital for the development as well as maintenance of health and homeostasis. Two unique abilities set them apart from other cells: self-renewal and the capacity for differentiation. They play important roles in embryogenesis, development, regeneration, and various other processes. Over the last decade, there has been increased interest in their potential use in the treatment of numerous diseases and disorders across multiple fields of medicine in acute, chronic, innate, and acquired diseases. Stem cells are key to maintaining the body's homeostasis and regulating growth and tissue functions. There are several types of stem cells-embryonic, adult, and human-induced pluripotent cells. Currently, mesenchymal stem cells are of great interest due to their regenerative, immunomodulatory, analgesic, and antimicrobial (anti-inflammatory) effects. Recent studies have shown the potent regenerative effect of stem cell therapy in gynecologic diseases such as infertility, Asherman syndrome, lichen sclerosus, polycystic ovary syndrome, premature ovarian insufficiency, genitourinary syndrome of menopause, and rectovaginal fistulas. Moreover, the successful isolation of oogonial stem cells could lead to a revolution in the field of gynecology and the potential treatment of the conditions discussed. This review aims to provide a better understanding of the latest therapeutic options involving stem cells and raise awareness of this promising yet not widely known topic in gynecology and medicine in general.

Platelet-derived exosomes induce cell proliferation and wound healing in human endometrial cells

Aim: To investigate the regenerative effects of a platelet-derived purified exosome product (PEP) on human endometrial cells. Materials & methods: Endometrial adenocarcinoma cells (HEC-1A), endometrial stromal cells (T HESC) and menstrual blood-derived stem cells (MenSC) were assessed for exosome absorption and subsequent changes in cell proliferation and wound healing properties over 48 h. Results: Cell proliferation increased in PEP treated T HESC (p < 0.0001) and MenSC (p < 0.001) after 6 h and in HEC-1A (p < 0.01) after 12 h. PEP improved wound healing after 6 h in HEC-1A (p < 0.01) and MenSC (p < 0.0001) and in T HESC between 24 and 36 h (p < 0.05). Conclusion: PEP was absorbed by three different endometrial cell types. PEP treatment increased cell proliferation and wound healing capacity.

Human iPSC-Vascular smooth muscle cell spheroids demonstrate size-dependent alterations in cellular viability and secretory function

Human-induced pluripotent stem cells (hiPSC) and their differentiated vascular cells have been revolutionizing the field of regenerative wound healing. These cells are shown to be rejuvenated with immense potentials in secreting paracrine factors. Recently, hiPSC-derived vascular smooth muscle cells (hiPSC-VSMC) have shown regenerative wound healing ability via their paracrine secretion. The quest to modulate the secretory function of these hiPSC-VSMC is an ongoing effort and involves the use of both biochemical and biophysical stimuli. This study explores the development and optimization of a reproducible, inexpensive protocol to form hiPSC-VSMC derived spheroids to investigate the implications of spheroid size on viability and paracrine secretion. Our data show the successful formation of different sizes of spheroids using various amount of hiPSC-VSMC. The hiPSC-VSMC spheroids formed with 10,000 cells strike an ideal balance between overall cell health and maximal paracrine secretion. The conditioned medium from these spheroids was found to be bioactive in enhancing human dermal fibroblast cell proliferation and migration. This research will inform future studies on the optimal spheroid size for regenerative wound healing applications.

Uterine Cavity Parameters Evaluated by Hysteroscopy can Predict the Live Birth Rate For Intrauterine Adhesion Patients

We aim to establish an objective and accurate prediction model by evaluating the uterine cavity and correlate these key factors with the live birth rate after hysteroscopic adhesiolysis (HA). A total of 457 intrauterine adhesions (IUA) patients were retrospectively enrolled in this study. The participants underwent HA and second-look hysteroscopy at the Third Xiangya Hospital of Central South University. Pregnancy outcomes, including spontaneous live births and no live births (miscarriages and infertility), were followed. Clinical parameters, containing the number of visible uterine horns and tubal ostia, the length of the uterine cavity, among others, were measured and analyzed to determine the dominant variables in an attempt to establish the live birth rate, prediction models. Women in the no live birth group were older than that in the live birth group (P = 0.0002, OR = 0.895, 95% CI: 0.844–0.949) and were more likely to be 2 gravidity (P = 0.0136, OR = 2.558, 95% CI: 1.213–5.394). Uterine cavity length in pre-HA hysteroscopy was longer in the live birth group (P = 0.0018, OR = 1.735, 95% CI: 1.227–2.453), and adhesion scores in pre-HA hysteroscopy were more frequently above 6 (P = 0.0252, OR = 0.286, 95% CI: 0.096–0.856) in the no live birth group. During the second-look, hysteroscopy, visible bilateral fallopian tube ostia were more frequently observed in the live birth group (P = 0.0339, OR = 11.76, 95% CI: 1.207–114.611), and adhesion scores were 4–6 (P < 0.0001, OR = 0.032, 95% CI: 0.007–0.146) and above 6 (P < 0.0001, OR = 0.012, 95% CI: 0.002–0.073) in the no live birth group. The areas under the curves (AUCs) of the pre-HA and second-look hysteroscopy prediction models were 0.7552 and 0.8484, respectively. We established an objective and accurate method for evaluating the uterine cavity by hysteroscopy, and second-look hysteroscopy is more valuable than the fist hysteroscopy in predicting the live birth rate following HA. Visible bilateral fallopian tube ostia or adhesion scores were <4 in the second-look hysteroscopy might predict live birth after surgery.

Correlative study of preoperative three-dimensional transvaginal ultrasound findings and ongoing pregnancy/live birth in patients with intrauterine adhesions following hysteroscopic adhesiolysis: a retrospective study

BACKGROUND

Three-dimensional transvaginal ultrasound (3D-TVUS) has recently been adopted in the gynecological sciences as it provides an accurate illustration of adhesions and the extent of cavity damage, and hence, can be used as an essential tool for the prognosis of intrauterine adhesions (IUA). This study aims to demonstrate whether preoperative 3D-TVUS features are relevant to ongoing pregnancy and live births in patients with IUA following hysteroscopic adhesiolysis (HA).

METHODS

From February 22, 2018, to October 31, 2018, a total of 401 patients with moderate to severe IUA and underwent HA were retrospectively enrolled. Preoperative 3D-TVUS diagnosed data and the patients' basic information were collected, and patients were followed up over 2 years after HA for reproductive outcomes. The correlation between each imaging variable and ongoing pregnancy or live birth was analyzed by binary logistic regression.

RESULTS

Among the 401 patients, 143 had live births, 41 patients had abortions, and 217 patients were infertile. Thick endometrium was found to be favorable for ongoing pregnancy (ongoing pregnancy group =5.4±1.95 mm, no-ongoing pregnancy group =4.7±2.24 mm, P=0.0095) and live birth (live birth group=5.6±1.92 mm, no-live birth group =4.7±2.20 mm, P=0.0029). Scar contraction was not conducive for pregnancy, while the lower segmentation was not a risk factor for ongoing pregnancy (P=0.0003). It also was a risk factor for ongoing pregnancy (P<0.0001) and live birth (P<0.0001) when the segmentation of the endometrial absence was mainly in the upper and middle segments of the uterine cavity. The area under the curves (AUCs) of the prediction model for ongoing pregnancy and live birth were 0.9116 and 0.8751, respectively, based on the meaningful variables above combined with other clinical characteristics.

CONCLUSIONS

Preoperative 3D-TVUS features have a close correlation with ongoing pregnancy and live births in patients with IUA following HA, and can be applied for predicting ongoing pregnancy and live births in IUA patients post-HA.

Comparative analysis of extracellular vesicles isolated from human mesenchymal stem cells by different isolation methods and visualisation of their uptake

Various types of cells secrete extracellular vesicle (EVs) which contain proteins, lipids and nucleic acids and play important roles in inter-cellular signalling and pathological processes to impact the recipient cells. EVs have demonstrated their potential as biomarkers for disease and as therapeutic agents in regenerative medicine. In recent times, EVs derived from mesenchymal stem cells (MSCs), which are widely used as a promising medicinal product in many clinical applications, are being tested in many preclinical trials. However, the lack of standardization of MSC-derived EV isolation and analysis methods, restricts the utility of MSC-derived EVs in the clinical setting. Here, we focused on optimising the isolation method for EVs derived from MSCs. Four samples of EVs were isolated from human adipose derived MSC culture medium by differential ultracentrifugation with three different ultracentrifuge durations to investigate the influence of ultracentrifuge time on quality and quantity of MSC-derived EVs. Additionally, we used a commercial kit to extract EVs from MSC cultured medium and compared it with the ultracentrifugation method. The EV samples were then characterised for particle concentration, protein concentration, size distribution and the presence of known EV protein markers, by western blot and flow cytometry. A comparison of these results for the five samples demonstrated that 1 h of differential ultracentrifugation was optimal to isolate high quality and quantity of MSC-derived EVs from MSC cultured medium. Additionally, fluorescence imaging of the freshly isolated vs frozen EVs showed that freshly isolated EVs are taken up by cells more efficiently than frozen EVs. These finding establish a simple and reliable method of EV isolation from MSCs.

Therapeutic Potential of Menstrual Blood-Derived Stem Cell Transplantation for Intrauterine Adhesions

An increasing number of women experience intrauterine adhesion as a result of intrauterine operations, such as induced abortion, which can cause infertility, recurrent abortion and amenorrhea. Although some strategies have been applied clinically, such as hysteroscopy adhesiolysis of intrauterine adhesions, the results have not been promising. As regenerative medicine develops, research on menstrual blood-derived stem cell transplantation is increasing due to the properties of these cells, including self-renewal, differentiation, angiogenesis, anti-inflammation and immunomodulation. As a result, menstrual blood-derived stem cells may be an ideal cell source for the treatment of intrauterine adhesion. Excitingly, it has been reported that autologous menstrual blood stem cells could recovery injured endometrium and improve infertility in patients with refractory intrauterine adhesion. In this review, we discuss the possible potential of menstrual blood-derived stem cell transplantation for intrauterine adhesion, including the antifibrosis, angiogenesis, anti-inflammation and immunoregulation properties of the cells, which brings hopes for clinical therapy.

A Robust and Highly Efficient Approach for Isolation of Mesenchymal Stem Cells From Wharton's Jelly for Tissue Repair

Mesenchymal stem cells derived from umbilical cord Wharton's Jelly (WJ-MSCs) are emerging as promising therapeutics for a variety of diseases due to their ability of regeneration and immunomodulation, and their non-tumorigenic and non-immunogenic properties. Although multiple protocols have been developed for WJ-MSC isolation, insufficient cell numbers, heterogeneous cell population, and variations in procedures between different laboratories impede further clinical applications. Here, we compared six widely used WJ-MSC isolation methods regarding cell morphology, yield, purity, proliferation rate, and differentiation potential. Based on these analyses, we identified that the inefficiency of the extracellular matrix digestion results in low cell yield. Thus, we developed a new method called "Mince-Soak-Digest (MSD)" to isolate MSCs from WJ by incorporating a soaking step to facilitate the digestion of the extracellular matrix and release of the cells. Our newly developed method generates significantly higher cell yield (4- to 10-fold higher) than six widely used methods that we tested with high purity and consistency. Importantly, by transplantation of WJ-MSCs to the rat uterus, we repair the endometrial injury and restore the fertility of the rats. In conclusion, our results provide a robust and highly efficient approach for the isolation of WJ-MSCs to restore injured tissue. The higher efficiency of MSD assures the abundance of WJ-MSCs for clinical applications. Furthermore, the reliability of MSD contributes to the standardization of WJ-MSC isolation, which eliminates the discrepancies due to isolation procedures, thus facilitating the evaluation of the efficacy of WJ-MSCs across various human clinical applications.

Variability in the levels of exosomal miRNAs among human subjects could be explained by differential interactions of exosomes with the endothelium

Exosomes are 30-100 nm endosome-derived membrane vesicles, that contain specific RNA transcripts including mRNAs, and microRNAs (miRNAs) and have been implicated in cell-to-cell communication. Exosomal miRNAs in blood circulation have been attracting major interest as potential diagnostic and prognostic biomarkers in a variety of diseases including stroke, cancer, and inflammatory disorders. Despite the progress made in the utilization of circulating exosomal miRNAs as biomarkers for various human diseases and conditions, there are still difficulties in functionally utilizing such methods in the clinic due to the high variability observed among subjects. Attempts to use miRNA signatures have improved but have not eliminated the problem. Additionally, standardized laboratory practices may partially reduce variability but there is still an unknown biological factor that hinders the proper use of miRNAs as biomarkers. We hypothesize that this variability might be partially attributed to a differential interaction among circulating exosomes carrying those miRNAs with endothelial surface molecules that themselves may vary among individuals due to secondary conditions, for example, inflammation status. This differential interaction could potentially add variability to the level of the examined miRNA that is not directly attributed to the primary condition under study.

Endometrial Perivascular Progenitor Cells and Uterus Regeneration

Ovarian steroid-regulated cyclical regeneration of the endometrium is crucial for endometrial receptivity and embryo implantation, and it is dependent on the dynamic remodeling of the endometrial vasculature. Perivascular cells, including pericytes surrounding capillaries and microvessels and adventitial cells located in the outermost layer of large vessels, show properties of mesenchymal stem cells, and they are thus promising candidates for uterine regeneration. In this review, we discuss the structure and functions of the endometrial blood vasculature and their roles in endometrial regeneration, the main biomarkers and characteristics of perivascular cells in the endometrium, and stem cell-based angiogenetic therapy for Asherman’s syndrome.