Therapeutic Effects and Repair Mechanism of HGF Gene-Transfected Mesenchymal Stem Cells on Injured Endometrium

Evolution of biotechnological advances and regenerative therapies for endometrial disorders: a systematic review

BACKGROUND

The establishment and maintenance of pregnancy depend on endometrial competence. Asherman syndrome (AS) and intrauterine adhesions (IUA), or endometrial atrophy (EA) and thin endometrium (TE), can either originate autonomously or arise as a result from conditions (i.e. endometritis or congenital hypoplasia), or medical interventions (e.g. surgeries, hormonal therapies, uterine curettage or radiotherapy). Affected patients may present an altered or inadequate endometrial lining that hinders embryo implantation and increases the risk of poor pregnancy outcomes and miscarriage. In humans, AS/IUA and EA/TE are mainly treated with surgeries or pharmacotherapy, however the reported efficacy of these therapeutic approaches remains unclear. Thus, novel regenerative techniques utilizing stem cells, growth factors, or tissue engineering have emerged to improve reproductive outcomes.

OBJECTIVE AND RATIONALE

This review comprehensively summarizes the methodologies and outcomes of emerging biotechnologies (cellular, acellular, and bioengineering approaches) to treat human endometrial pathologies. Regenerative therapies derived from human tissues or blood which were studied in preclinical models (in vitro and in vivo) and clinical trials are discussed.

SEARCH METHODS

A systematic search of full-text articles available in PubMed and Embase was conducted to identify original peer-reviewed studies published in English between January 2000 and September 2023. The search terms included: human, uterus, endometrium, Asherman syndrome, intrauterine adhesions, endometrial atrophy, thin endometrium, endometritis, congenital hypoplasia, curettage, radiotherapy, regenerative therapy, bioengineering, stem cells, vesicles, platelet-rich plasma, biomaterials, microfluidic, bioprinting, organoids, hydrogel, scaffold, sheet, miRNA, sildenafil, nitroglycerine, aspirin, growth hormone, progesterone, and estrogen. Preclinical and clinical studies on cellular, acellular, and bioengineering strategies to repair or regenerate the human endometrium were included. Additional studies were identified through manual searches.

OUTCOMES

From a total of 4366 records identified, 164 studies (3.8%) were included for systematic review. Due to heterogeneity in the study design and measured outcome parameters in both preclinical and clinical studies, the findings were evaluated qualitatively and quantitatively without meta-analysis. Groups using stem cell-based treatments for endometrial pathologies commonly employed mesenchymal stem cells (MSCs) derived from the human bone marrow or umbilical cord. Alternatively, acellular therapies based on platelet-rich plasma (PRP) or extracellular vesicles are gaining popularity. These are accompanied by the emergence of bioengineering strategies based on extracellular matrix (ECM)-derived hydrogels or synthetic biosimilars that sustain local delivery of cells and growth factors, reporting promising results. Combined therapies that target multiple aspects of tissue repair and regeneration remain in preclinical testing but have shown translational value. This review highlights the myriad of therapeutic material sources, administration methods, and carriers that have been tested.

WIDER IMPLICATIONS

Therapies that promote endometrial proliferation, vascular development, and tissue repair may help restore endometrial function and, ultimately, fertility. Based on the existing evidence, cost, accessibility, and availability of the therapies, we propose the development of triple-hit regenerative strategies, potentially combining high-yield MSCs (e.g. from bone marrow or umbilical cord) with acellular treatments (PRP), possibly integrated in ECM hydrogels. Advances in biotechnologies together with insights from preclinical models will pave the way for developing personalized treatment regimens for patients with infertility-causing endometrial disorders such as AS/IUA, EA/TE, and endometritis.

REGISTRATION NUMBER

https://osf.io/th8yf/.

Mesenchymal Stem Cells Accelerate Recovery of Acetic Acid-Induced Chronic Gastric Ulcer by Regulating Ekt/Akt/TRIM29 Axis

Chronic gastric ulcer (CGU), a prevalent digestive disease, has a high incidence and is seriously harmful to human health. Mesenchymal stem cells (MSCs) have been proven to have beneficial therapeutic effects in many human diseases. Here, a CGU model induced by acetic acid in mice was used to evaluate the repair effects and potential mechanism of human umbilical cord-derived MSCs (hUC-MSCs) and hUC-MSCs derived conditioned medium (hUC-MSC-CM). We found that hUC-MSCs and hUC-MSC-CM treatment significantly repaired morphological characteristics of CGU, improved proliferation and decreased apoptosis of gastric cells, and promoted the generation of new blood vessels in granulation tissues. In addition, we could detect the homing of MSCs in gastric tissue, and MSCs may differentiate into Lgr5-positive cells. As well as this, in vitro experiments showed that hUC-MSC-CM could promote cell proliferation, stimulate cell cycle progression, and reduce the incidence of apoptosis. The transcriptome of cells and the iTRAQ proteome of gastric tissues suggest that MSCs may play a therapeutic role by increasing the expression of TRIM29. Additionally, it was found that knocking down TRIM29 significantly decreased the ameliorative effects of hUC-MSC-CM on cell apoptosis. As a result of further molecular experiments, it was found that TRIM29 is capable of phosphorylating Erk/Akt in specific cell type. As a whole, it appears that hUC-MSCs can be an effective therapeutic approach for promoting gastric ulcer healing and may exert therapeutic effects in the form of paracrine and differentiation into gastric cells.

The role and participation of immune cells in the endometrial tumor microenvironment

The tumor microenvironment is surrounded by blood vessels and consists of malignant, non-malignant, and immune cells, as well as signalling molecules, which primarily affect the therapeutic response and curative effects of drugs in clinical studies. Tumor-infiltrating immune cells participate in tumor progression, impact anticancer therapy, and eventually lead to the development of immune tolerance. Immunotherapy is evolving as a promising therapeutic intervention to stimulate and activate the immune system to suppress cancer cell growth. Endometrial cancer (EC) is an immunogenic disease, and in recent years, immunotherapy has shown benefit in the treatment of recurrent and advanced EC. This review discusses the key molecular pathways associated with the intra-tumoral immune response and the involvement of circulatory signalling molecules. Specific immunologic signatures in EC which offer targets for immunomodulating agents, are also discussed. We have summarized the available literature in support of using immunotherapy in EC. Lastly, we have also discussed ongoing clinical trials that may offer additional promising immunotherapy options in the future. The manuscript also explored innovative approaches for screening and identifying effective drugs, and to reduce the financial burdens for the development of personalized treatment strategies. Collectively, we aim to provide a comprehensive review of the role of immune cells and the tumor microenvironment in the development, progression, and treatment of EC.