Effectiveness of Stem Cell Therapy in the Treatment of Ovarian Disorders and Female Infertility: A Systematic Review

Ovarian aging in humans: potential strategies for extending reproductive lifespan

Ovarian reserve is a term used to estimate the total number of immature follicles present in the ovaries. Between birth and menopause, there is a progressive decrease in the number of ovarian follicles. Ovarian aging is a continuous physiological phenomenon, with menopause being the clinical mark of the end of ovarian function. Genetics, measured as family history for age at the onset of menopause, is the main determinant. However, physical activity, diet, and lifestyle are important factors that can influence the age of menopause. The low estrogen levels after natural or premature menopause increased the risk for several diseases, resulting in increased mortality risk. Besides that, the decreasing ovarian reserve is associated to reduced fertility. In women with infertility undergoing in vitro fertilization, reduced markers of ovarian reserve, including antral follicular count and anti-Mullerian hormone, are the main indicators of reduced chances of becoming pregnant. Therefore, it becomes clear that the ovarian reserve has a central role in women's life, affecting fertility early in life and overall health later in life. Based on this, the ideal strategy for delaying ovarian aging should have the following characteristics: (1) be initiated in the presence of good ovarian reserve; (2) maintained for a long period; (3) have an action on the dynamics of primordial follicles, controlling the rate of activation and atresia; and (4) safe use in pre-conception, pregnancy, and lactation. In this review, we therefore discuss some of these strategies and its feasibility for preventing a decline in the ovarian reserve.

MicroRNA-146 attenuates lipopolysaccharide induced ovarian dysfunction by inhibiting the TLR4/NF- κB signaling pathway

Premature ovarian insufficiency (POI) is a disease that seriously affects women’s reproductive function and even leads to lifelong infertility. Little is known about the mechanism of lipopolysaccharide (LPS)-induced ovarian dysfunction. Thus, we aimed to identify the role of the up-regulation of microRNA (miRNA)-146 expression offered protection against ovarian dysfunction by inhibiting the toll-like receptor (TLR) 4, TLR4/phosphorylated (p)-nuclear factor (NF)-κB signaling pathway and inflammatory cytokine tumor necrosis factor (TNF)-a and Interleukin (IL)-6. In an in vivo study, we established an LPS-induced ovarian dysfunction mouse model. The mouse ovarian granulosa cells were transfected with miR-146 mimic or negative controls or inhibitor and then treated with LPS. Therefore, cell viability, cells apoptosis, IL-6 and TNF-a, TLR4, NF- κB were assessed, respectively. These results demonstrated that the up-regulation of miRNA-146 expression may protect against LPS-induced ovarian dysfunction and markedly increased the cell viability, and significantly reduced the ovarian granulosa cells apoptotic rate, and down-regulated IL-6 and TNF-a expression. In addition, miRNA-146 exerted protective ovarian functions might be via inhibiting TLR4/NF-κB signaling pathway. In summary, we reveal the up-regulation of miRNA-146 expression mitigated ovarian dysfunction by negatively regulating expression of the IL-6 and TNF-a, which may shed light on the potential molecular mechanisms of overexpression of miRNA-146 may reversed the ovarian dysfunction by inhibiting the TLR4/ NF-κB signaling pathway.

A bibliometric analysis of primary ovarian insufficiency from 2010 to 2020

OBJECTIVE

This study aimed to carry out a bibliometric analysis of primary ovarian insufficiency (POI) from 2010 to 2020 and to reveal the research status and hotspots in the future.

METHOD

A total of 3087 articles and reviews related to POI published from 2010 to 2020 retrieved from the Web of Science Core Collection were used for bibliometric analysis. CiteSpace and VOSviewer were adopted to analyze countries and regions, organizations, authors, journals, keywords and co-cited references.

RESULTS

The number of publications about POI increased year by year. The USA produced the largest number of publications and the most influence in this field. The main research directions of POI can be roughly divided into four aspects according to the analysis of keywords and co-cited references: genetic research of POI; stem cell therapy for patients with POI; prediction of ovarian function; and fertility preservation of cancer patients. Genetic research and stem cell therapy may become research hotspots in the future.

CONCLUSION

This study might be the first bibliometric study to analyze publications of POI from multiple indicators, in order to provide new opinions for the research trends and possible hotspots of POI.

Application of collagen and mesenchymal stem cells in regenerative dentistry

Collagen is an important macromolecule of extracellular matrix (ECM) in bones, teeth, and temporomandibular joints. Mesenchymal stem cells (MSCs) interact with the components of the ECM such as collagen, proteoglycans, glycosaminoglycans (GAGs), and several proteins on behalf of variable matrix elasticity and bioactive cues. Synthetic collagen-based biomaterials could be effective scaffolds for regenerative dentistry applications due to mimicking of host tissues' ECM. These biomaterials are biocompatible, biodegradable, readily available, and non-toxic to cells whose capability promotes cellular response and wound healing in the craniofacial region. Collagen could incorporate other biomolecules to induce mineralization in calcified tissues such as bone and tooth. Moreover, the addition of these molecules or other polymers to collagen-based biomaterials could enhance mechanical properties, which is important in load-bearing areas such as the mandible. A literature review was performed via reliable internet database (mainly PubMed) based on MeSH keywords. This review first describes the properties of collagen as a key protein in the structure of hard tissues. Then, it introduces different types of collagens, the correlation between collagen and MSCs, and the methods used to modify collagen in regenerative dentistry including recent progression on the regeneration of periodontium, dentin-pulp complex, and temporomandibular joint by applying collagen. Besides, the prospects and challenges of collagen-based biomaterials in the craniofacial region pointes out.

Restoration of Fertility in Patients with Spontaneous Premature Ovarian Insufficiency: New Techniques under the Microscope

Premature ovarian insufficiency (POI), a condition affecting up to 1% of women by the age of 40 years, is characterized by an extremely low chance of spontaneous pregnancy. Currently, fertility restoration options are virtually nonexistent for this population. To become pregnant, the only solution is egg donation. Interestingly, animal studies have provided encouraging results in terms of fertility restoration, and consequently, research has begun into the most promising approaches for women suffering from POI. The PubMed database was searched for studies in which techniques aiming at restoring fertility in women with spontaneous POI were tested. Although robust studies are lacking, the literature suggests a positive effect of certain techniques on fertility restoration in women with POI. The most promising approaches seem to be intraovarian injection of autologous platelet-rich plasma or of mesenchymal stem cells. In addition to these, in vitro and mechanical activation of dormant follicles and etiology-driven therapies have also been studied with mixed results. No safety concerns were raised in these studies. The absence of robust studies does not allow us to draw meaningful conclusions on the efficacy or superiority of any single technique at this stage, and so research in this area should continue using robust study designs, i.e., multicenter randomized controlled trials including sufficient subjects to achieve statistical power.

Effects of single and multiple transplantations of human umbilical cord mesenchymal stem cells on the recovery of ovarian function in the treatment of premature ovarian failure in mice

BACKGROUND

Currently, there is no effective treatment for premature ovarian failure (POF), and stem cell therapy is considered the most promising treatment. Human umbilical cord blood mesenchymal stem cells (hUC-MSCs) have shown good regenerative ability in various diseases, including POF; however, their underlying mechanism and dosage for POF treatment remain unclear. This study aimed to compare the effect of single and multiple injections of hUC-MSCs on ovarian function repair in chemotherapy-induced POF.

METHODS

Female mice were intraperitoneally injected with 30 mg/kg busulfan and 120 mg/kg cyclophosphamide (CTX) to induce POF. In the single hUC-MSC injection group, hUC-MSCs were transplanted into mice D7 after CTX and busulfan administration, while in the multiple injection group, hUC-MSCs were transplanted on D7, D14, and D21 after CTX and busulfan administration. We evaluated the ovarian morphology, fertility, follicle-stimulating hormone and estradiol concentrations, follicle count, POF model, and cell transplantation results. In addition, real-time polymerase chain reaction, immunohistochemistry, and miRNA and mRNA chips were used to evaluate the effect of the cell therapy.

RESULTS

Ovary size, number of follicle at all developmental stages, and fertility were significantly reduced in the POF group compared with the control. Under hUC-MSC treatment, the ovarian morphology and follicle count were significantly restored, and fertility was significantly increased. By comparing the single and multiple hUC-MSC injection groups, we found that the anti-Müllerian hormone and Ki-67 levels were significantly increased in the multiple hUC-MSC group on D60 after chemotherapy. The expression of stimulating hormone receptors, inhibin α, and inhibin β was significantly restored, and the therapeutic effect was superior to that of the single hUC-MSC injection group.

CONCLUSION

These results indicate that hUC-MSCs can restore the structure of injured ovarian tissue and its function in chemotherapy-induced POF mice and ameliorate fertility. Multiple hUC-MSC transplantations have a better effect on the recovery of ovarian function than single hUC-MSC transplantation in POF.

Qilin Pill Exerts Therapeutic Effect on Resection-Induced Premature Ovarian Insufficiency Rats by Inhibiting the MAPK and PI3K-AKT Signaling Pathways

Background

The Qilin pill (QLP) is a traditional Chinese compound prescription comprising 15 herbs that has demonstrated significant therapeutic effects on premature ovarian insufficiency (POI) in recent years. However, a pharmacological evaluation of QLP on ovarian function remains to be conducted, and the key mechanism of QLP treatment on POI is unclear.

Methods

Premature ovarian insufficiency rats were established by bilateral partial ovariectomy. The model rats were administrated with low (QLP-L), medium (QLP-M) and high (QLP-H) doses of QLP for 4 weeks to evaluate the ovarian function in terms of estrous cycle, hormone level, and follicle count. The mechanism of QLP in the treatment of POI was systematically explored by network pharmacology, and expression levels of the MAPK and PI3K-AKT signaling pathways were verified by Western blotting and molecular docking.

Results

The rat model of resection-induced POI was successfully established, and QLP could significantly recover the estrous cycle, decrease serum FSH levels, and decelerate follicle depletion after 4 weeks of administration. The optimal dose of QLP in the experiment was preliminarily determined to be 0.9 g/kg. Based on the network pharmacology methods, we constructed the compound-target network and protein protein interaction (PPI) network of QLP for the treatment of POI. The experimental verification of the enrichment analysis showed that QLP inhibited the MAPK and PI3K-AKT signaling pathways, and the key compounds and key targets involved were verified by molecular docking.

Conclusion

QLP exerted significant therapeutic effects on resection-induced POI rats, and this was achieved by the inhibition of the MAPK and PI3K-AKT signaling pathways. This study is the first to systematically investigate the effects and mechanism of QLP on POI rats, which will provide valuable guidance in clinic.

Intra-ovarian injection of platelet-rich plasma into ovarian tissue promoted rejuvenation in the rat model of premature ovarian insufficiency and restored ovulation rate via angiogenesis modulation

Premature Ovarian Insufficiency (POI) is viewed as a type of infertility in which the menopausal status occurs before the physiological age. Several therapeutic strategies have been introduced in clinic for POI treatment, although the outputs are not fully convincing. Platelet-rich plasma (PRP) is a unique blood product widely applied in regenerative medicine, which is based on the releasing of the growth factors present in platelets α-granules. In the current investigation, we examined the effectiveness of PRP as a therapeutic alternative for POI animals. POI in Wistar albino rats was induced by daily intraperitoneal (IP) administration of gonadotoxic chemical agent, 4-vinylcyclohexene dioxide (VCD) (160 mg/ kg) for 15 consecutive days. After POI induction, the PRP solution was directly injected intra-ovarian in two concentrations via a surgical intervention. Every two weeks post-injection, pathological changes were monitored in the ovaries using Hematoxylin-Eosin staining method, until eight weeks. Follicle Stimulating Hormone (FSH) content in serum was measured, together with the expression of the angiogenic-related transcripts ANGPT2 and KDR by real-time qPCR. Furthermore the fertility status of the treated rats was evaluated by mating trials. Histopathological examination revealed successful POI induction via the depletion of morphologically normal follicles in rats following VCD treatment compared to the control rats. The injection of PRP at two concentrations reduced the number and extent of the follicular atresia and inflammatory responses (p < 0.05). The expression of both ANGPT2 and KDR transcripts were significantly increased in POI rats due to enhanced inflammation, while these values were modulated after PRP administration (p < 0.05) compared to POI rats. FSH showed a decreased trend in concentration eight weeks after PRP treatment, but not statistically significant (p > 0.05). Nevertheless, a clear improvement in litter counts was found in POI rats receiving PRP compared to the non-treated POI group, being able to consider PRP as a facile, quick, accessible, safe and relatively cheap alternative therapeutic strategy to revert POI-related pathologies.