Mechanistic action of mesenchymal stem cell injection in the treatment of chemically induced ovarian failure in rabbits

Determination of the effects of bone marrow derived mesenchymal stem cells and ovarian stromal stem cells on follicular maturation in cyclophosphamide induced ovarian failure in rats

OBJECTIVE

Chemotherapy causes depletion of primordial follicles that leads to premature ovarian failure in female cancer survivals. We investigated the effect of bone marrow derived mesenchymal (BMMSCs) and ovarian stromal stem cells (OSSCs) on follicle maturation in chemotherapy induced ovarian failure.

MATERIAL AND METHODS

Thirty six Wistar Albino female rats were divided into three groups. Cyclophosphamide at a dose of 200 mg/kg was intraperitoneally (IP) given to the rats in all groups two times. 4 × 10⁶ BMMSCs (IP) was injected to the group-2 and 4 × 10⁶ OSSCs (IP) was injected to the group-3. Serum Anti-Müllerian Hormone (AMH) levels was determined with ELISA and primordial follicles were counted for investigation of primordial follicle reserve. The ovarian structure were evaluated histomorphologically. Localization of BrdU labeled stem cells, the expression of the cell cycle regulator p34Cdc2, gap junction protein p-connexin43 and intraovarian regulators of folliculogenesis Bone Morphogenic Protein 6 and 15 (BMP-6 and BMP-15) were investigated by immunohistochemistry.

RESULTS

The immunstaining of BMP-6 was higher in oocytes of group-3 more than group-1 and group-2. The immunpositivity of p34cdc2 and BMP-15 were also higher in follicular cells of group-3 than the other groups. The presence of p-connexin43 in group-3 was determined more than group-1 and group-2. The ovarian follicles with normal histological structure were observed just in group-3. Although, The AMH levels were decreased in rats from all groups at the end of experimental procedure the primordial follicle counts in group-3 was significantly higher than group-1.

CONCLUSION

Our findings suggest that OSSCs have more protective effect on follicle maturation than BMMSCs in cyclophosphamide induced ovarian damage.

Mesenchymal stem cells for restoration of ovarian function

With the progress of regenerative medicine, mesenchymal stem cells (MSCs) have received attention as a way to restore ovarian function. It has been reported that MSCs derived from bone marrow, adipose, umbilical cord blood, menstrual blood, and amniotic fluid improved ovarian function. In light of previous studies and advances in this field, there are increased expectations regarding the utilization of MSCs to restore ovarian function. This review summarizes recent research into potential applications of MSCs in women with infertility or primary ovarian insufficiency, including cases where these conditions are induced by anticancer therapy.

Umbilical Cord Blood Mesenchymal Stem Cells as an Infertility Treatment for Chemotherapy Induced Premature Ovarian Insufficiency

Background: Premature ovarian insufficiency (POI) is a challenging disease, with limited treatment options at the moment. Umbilical cord blood mesenchymal stem cells (UCMSCs) have demonstrated promising regenerative abilities in several diseases including POI. Materials and Method: A pre-clinical murine case versus vehicle control randomized study. Two experiments ran in parallel in each of the three groups. The first was to prove the ability of UCMSCs in restoring ovarian functions. The second was to prove improved fertility. A total of 36 mice were randomly assigned; 6 mice into each of 3 groups for two experiments. Group 1 (control), group 2 (sham chemotherapy), group 3 (stem cells). Results: In the first experiment, post-UCMSCs treatment (group 3) showed signs of restored ovarian function in the form of increased ovarian weight and estrogen-dependent organs (liver, uterus), increased follicular number, and a significant decrease in FSH serum levels (p < 0.05) compared to group 2, and anti-Mullerian hormone (AMH) serum levels increased (p < 0.05) in group 3 versus group 2. Immuno-histochemistry analysis demonstrated a higher expression of AMH, follicle stimulating hormone receptor (FSHR) and Inhibin A in the growing follicles of group 3 versus group 2. In the second experiment, post-UCMSCs treatment (group 3) pregnancy rates were higher than group 2, however, they were still lower than group 1. Conclusion: We demonstrated the ability of UCMSCs to restore fertility in female cancer survivors with POI and as another source of stem cells with therapeutic potentials.

Woven collagen biotextiles enable mechanically functional rotator cuff tendon regeneration during repair of segmental tendon defects in vivo

Despite advancements in surgical techniques and materials for rotator cuff repair procedures, primary repair failures remain common. This study examines the use of electrochemically aligned collagen (ELAC) threads woven into biotextile scaffolds as grafts to repair critical infraspinatus tendon defects in New Zealand White rabbits. Three surgical treatment groups were evaluated: rabbits undergoing direct repair as operative controls, rabbits receiving ELAC scaffolds alone, and rabbits treated with mesenchymal stem cell (MSC)-seeded ELAC scaffolds. In each animal, the intact, contralateral infraspinatus served as an internal positive control. Tendon-bone constructs were harvested after 3 months in vivo and outcome measures included biomechanical testing, histological staining, and immunohistochemical staining. Biomechanical testing revealed that maximum load-bearing capacity was comparable between all groups, while MSC-seeded scaffold repairs exhibited increased stiffness relative to non-seeded scaffold repairs. Histological staining revealed robust collagen deposition around ELAC fibers and increased cellularity within the continuum of woven scaffolds as compared to native tendon. Immunohistochemical staining revealed presence of collagens I and III in all groups, but procollagen I and the tendon-specific marker tenomodulin were only observed in seeded and non-seeded ELAC scaffold repairs. Findings of this pilot study warrant continued investigation of ELAC biotextile scaffolds for repair of critically-sized rotator cuff tendon defects. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1864-1876, 2019.

Effect of intra-ovarian injection of mesenchymal stem cells in aged mares

PURPOSE

This study aims to determine if intra-ovarian injection of bone marrow-derived mesenchymal stem cells (MSCs) improves or restores ovarian function in aged females.

METHODS

Prospective randomized study of eight aged mares and six young mares receiving intra-ovarian injection of MSCs or vehicle. Main outcome measures were antral follicle count and serum anti-Müllerian hormone (AMH) (aged and young mares), and for aged mares, oocyte meiotic and developmental competence; gross and histological ovarian assessment; evaluation of presence of chimerism in recovered granulosa cells and in ovarian tissue samples; and gene expression in ovarian tissue as assessed by RNA sequencing.

RESULTS

Injection of MSCs was not associated with significant changes in follicle number, oocyte recovery rate on follicle aspiration, oocyte maturation rate, or blastocyst rate after ICSI in aged mares, or in changes in follicle number in young mares. There were no significant changes in peripheral AMH concentrations, indicating a lack of effect on growing follicles. MSC donor DNA was not recovered in granulosa cells or in ovarian tissue, indicating lack of persistence of injected MSC. RNA sequencing revealed significant differences in gene expression between MSC- and vehicle-injected ovaries.

CONCLUSIONS

Intra-ovarian injection of bone marrow-derived MSCs altered gene expression but did not improve ovarian function in aged mares.

Mesenchymal Stem Cells (MSCs) Therapy for Recovery of Fertility: a Systematic Review

In recent years, the mesenchymal stem cells (MSCs) have provided the new opportunities to treat different disorders including infertility. Different studies have suggested that the MSCs have ability to differentiate into germ-like cells under specific induction conditions as well as transplantation to gonadal tissues. The aim of this systematic review was to evaluate the results obtained from different studies on MSCs therapy for promoting fertility. This search was done in PubMed and Science Direct databases using key words MSCs, infertility, therapy, germ cell, azoospermia, ovarian failure and mesenchymal stem cell. Among the more than 11,400 papers, 53 studies were considered eligible for more evaluations. The obtained results indicated that the most studies were performed on MSCs derived from bone marrow and umbilical cord as compared with the other types of MSCs. Different evaluations on animal models as well as in vitro studies supported from their role in the recovery of spermatogenesis and folliculogenesis. Although the data obtained from this systematic review are promising, but the further studies need to assess the efficiency and safety of transplantation of these cells in fertility recovery.

Improvement of the folliculogenesis by transplantation of bone marrow mesenchymal stromal cells in mice with induced polycystic ovary syndrome

BACKGROUND

Many studies have reported that inflammation and oxidative stress are involved in the pathogenesis of polycystic ovary syndrome (PCOS). Bone marrow mesenchymal stromal cells (BM-MSCs) have anti-oxidant and anti-inflammation properties. In this study, we investigate the beneficial effect of stem cell therapy on folliculogenesis in mice with induced PCOS METHODS: Mouse model of PCOS was performed through daily injection of testosterone enanthate (1 mg/100 g/body weight subcutaneous (s.c).) for a period of 5 weeks. Naval Medical Research Institute (NMRI) mice (21 days old) were divided into three groups: control, PCOS and PCOS + BM-MSCs. BM-MSCs were labeled with Hoechst 33342 (0.5 µg/mL) and then injected into the mice (10⁶/animal, via the tail vein) at 1 and 14 days after PCOS confirmation. Mice were humanely killed at 2 weeks after last transplantation. Ovarian stereological studies were done. Follicle-stimulating hormone (FSH), Luteinizing hormone (LH), testosterone, interleukin (IL)-6 and tumor necrosis factor (TNF)-α serum levels were measured. The levels of malondialdehyde (MDA) and total antioxidant capacity (TAC) in serum were analyzed. Apoptotic index for ovarian follicles was assessed using Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL). CD31 expression in ovarian vessels was assessed with the immunohistochemistry.

RESULTS

There was a significant increase in the total volume of ovary, cortex, number of antral follicles, volume of oocyte and zona pellucida thickness, and there was a significant decrease in the primary and preantral follicles number in the PCOS + BM-MSCs group compared with the PCOS group. There was a significant increase in the serum level of FSH and TAC and a significant decrease in the serum level of testosterone, LH, MDA and percentage of TUNEL-positive apoptotic cells in the PCOS + BM-MSCs group in comparison with the PCOS group.

DISCUSSION

BM-MSC transplantation improves folliculogenesis in mice with induced PCOS. BM-MSC therapy can be an operative treatment for PCOS via anti-inflammatory, anti-oxidant and anti-apoptotic properties.

The current understanding of mesenchymal stem cells as potential attenuators of chemotherapy-induced toxicity

Chemotherapeutic agents are part of the standard treatment algorithms for many malignancies; however, their application and dosage are limited by their toxic effects to normal tissues. Chemotherapy-induced toxicities can be long-lasting and may be incompletely reversible; therefore, causative therapies for chemotherapy-dependent side effects are needed, especially considering the increasing survival rates of treated cancer patients. Mesenchymal stem cells (MSCs) have been shown to exhibit regenerative abilities for various forms of tissue damage. Preclinical data suggest that MSCs may also help to alleviate tissue lesions caused by chemotherapeutic agents, mainly by establishing a protective microenvironment for functional cells. Due to the systemic administration of most anticancer agents, the effects of these drugs on the MSCs themselves are of crucial importance to use stem cell-based approaches for the treatment of chemotherapy-induced tissue toxicities. Here, we present a concise review of the published data regarding the influence of various classes of chemotherapeutic agents on the survival, stem cell characteristics and physiological functions of MSCs. Molecular mechanisms underlying the effects are outlined, and resulting challenges of MSC-based treatments for chemotherapy-induced tissue injuries are discussed.

Human chorionic plate-derived mesenchymal stem cells transplantation restores ovarian function in a chemotherapy-induced mouse model of premature ovarian failure

Background

Previous studies have reported that transplantation of mesenchymal stem cells (MSCs) from many human tissues could ameliorate ovarian dysfunction. However, no study has revealed the therapeutic efficiency of MSCs derived from the chorionic plate (CP-MSCs) for premature ovarian failure (POF).

Methods

We investigated the restorative effects of CP-MSCs on cyclophosphamide (CTX)-induced POF. The POF mouse models were established via intraperitoneal injection of 50 mg/kg CTX into female mice for 15 consecutive days. After that, CP-MSCs were intravenously transplanted into the mice once a week for 4 weeks. The serum estradiol (E2) and follicle-stimulating hormone (FSH) levels in the mouse models were detected using enzyme-linked immunosorbent assay (ELISA) before and after treatment. Ovarian function was evaluated through counting the follicles, estrous cycles, and oocytes.

Results

CP-MSC transplantation restored the serum hormone level and ovarian function of the mice in the mouse model of POF induced by CTX. The levels of serum E2 and FSH in the POF model group was 232.33 ± 17.16 pg/mL and 4.48 ± 0.29 mIU/mL, respectively, after 6 weeks of treatment, which were similar to the values in the wild-type (WT) group. The superovulation demonstrated that ovarian function was significantly improved compared with nontreated POF model mice. The CP-MSC transplantation could restore CTX-induced ovarian dysfunction.

Conclusions

Our results offer a potential application for human CP-MSCs in POF treatment.

Current approaches for the treatment of premature ovarian failure with stem cell therapy

One of the common disorders found in women is premature ovarian failure (POF). Recently some studies have explained premature ovarian insufficiency (POI). The causes of it are unknown although various types of study have been done. The most common causes such as genetic and autoimmune conditions can have a role in POF and can lead to infertility. Some characterization of POF are hypo-oestrogenism (estrogen deficiency), increased gonadotropin level and most importantly amenorrhea. The main purpose of this review is to describe the cause and treatment of POF, especially stem cell therapy proposed in previous studies. Stem cells have self-renewal and regeneration potential, hence they can be very effective in the treatment of ovarian failure and consequently infertility. There are several kinds of stem cells such as, mesenchymal stem cells (MSCs), stem cells from extra-embryonic tissues, induced pluripotent stem cells (iPSCs), and ovarian stem cells that are used in POF stem cell therapy as observed in previous studies. This article reviews the latest studies on POF to summarize current understanding and future directions.

Fertility rescue and ovarian follicle growth promotion by bone marrow stem cell infusion

OBJECTIVE

To assess if infusion of human bone marrow-derived stem cells (BMDSCs) could promote follicle development in patients with impaired ovarian functions.

DESIGN

Experimental design.

SETTING

University research laboratories.

ANIMAL(S)

Immunodeficient NOD/SCID female mice.

INTERVENTION(S)

Human BMDSCs were injected into mice with chemotherapy-induced ovarian damage and into immunodeficient mice xenografted with human cortex from poor-responder patients (PRs).

MAIN OUTCOME MEASURE(S)

Follicle development, ovulation, and offspring. Apoptosis, proliferation, and vascularization were evaluated in mouse and human ovarian stroma.

RESULT(S)

Fertility rescue and spontaneous pregnancies were achieved in mice ovaries mimicking PRs and ovarian insufficiency, induced by chemotherapy, after BMDSC infusion. Furthermore, BMDSC treatment resulted in production of higher numbers of preovulatory follicles, metaphase II oocytes, 2-cell embryos, and healthy pups. Stem cells promoted ovarian vascularization and cell proliferation, along with reduced apoptosis. In xenografted human ovarian tissues from PRs, infusion of BMDSCs and their CD133+ fraction led to their engraftment close to follicles, resulting in promotion of follicular growth, increases in E₂ secretion, and enhanced local vascularization.

CONCLUSION(S)

Our results raised the possibility that promoting ovarian angiogenesis by BMDSC infusion could be an alternative approach to improve follicular development in women with impaired ovarian function.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02240342.

Effect of stem cell transplantation of premature ovarian failure in animal models and patients: A meta-analysis and case report

Stem cell transplantation has been considered a promising therapeutic approach for premature ovarian failure (POF). However, to date, no quantitative data analysis of stem cell therapy for POF has been performed. Therefore, the present study performed a meta-analysis to assess the efficacy of stem cell transplantation in improving ovarian function in animal models of POF. In addition, a case report of a patient with POF subjected to stem cell treatment was included to demonstrate that stem cell therapy also contributes to the recovery of ovarian function in patients. Published studies were identified by a systematic review of the PubMed, Embase, and Cochrane's library databases, and references cited in associated reviews were also considered. Data regarding follicle-stimulating hormone (FSH), estradiol (E2), ovarian weight, follicle count, the number of pregnancies and other parameters, including delivery route and cell type, were extracted. Pooled analysis, sensitivity analyses, subgroup analyses and meta-regression were performed. In the case of POF, transvaginal ultrasound (TVS), abdominal ultrasound (TAS) and color Doppler flow imaging (CDFI) were performed to observe the endometrial morphology and blood flow signals in the patient. Overall, pooled results from 16 pre-clinical studies demonstrated that stem cell-based therapy significantly improved FSH levels [standardized mean difference (SMD)=-1.330; 95% confidence interval (CI), -(2.095-0.565); P=0.001], E2 levels (SMD=2.334; 95% CI, 1.350-3.319; P<0.001), ovarian weight (SMD=1.310; 95% CI, 0.157-2.463; P=0.026), follicle count (SMD=1.871; 95% CI, 1.226-2.516; P<0.001), and the number of pregnancies (risk ratio=1.715, 95% CI, 1.213-2.424; P=0.002). The results of TVS and TAS demonstrated improved ovarian size and endometrial thickness in the patient with POF after MSC treatment. Of note, a rich blood flow signal in the endometrium was observed on CDFI. It appeared that stem cell-based therapy may be an effective method for the resumption of ovarian function in a patient and in animal models of POF; however, large-scale and high-quality future studies are required to confirm the present findings due to heterogeneity.

Effect of Multiple Intraperitoneal Injections of Human Bone Marrow Mesenchymal Stem Cells on Cuprizone Model of Multiple Sclerosis

Background:

Bone marrow mesenchymal stem cells (BM-MSCs) elicit neuroprotective effects, and their repair ability has been investigated in different experimental models. We aimed to investigate the effect of multiple i.p. BM-MSCs injections in the cuprizone model of multiple sclerosis in mice.

Methods:

Adult male C57BL/6 mice (n = 40) were fed a regular diet or a diet containing cuprizone (0.2% w/w) for six weeks. Bone marrow samples were taken from patients with spinal cord injury. BM-MSCs (2 × 10⁶ in 1 milliliter medium) were administered intraperitoneally for two consecutive weeks at the end of the forth weeks of cuprizone administration. Animals (n = 12) were perfused with 10% paraformaldehyde at the end of sixth week. The brains were sectioned coronally in 6-8-μm thickness (-2.3 to 1.8 mm from bregma). The sections were stained by luxol fast blue-cresyl violet, and images were captured via a microscope. Demyelination ratio was estimated in corpus callosum in a blind manner. A quantitative real-time PCR was used to measure the myelin basic protein gene expression at sixth week.

Results:

Histologically, cuprizone induced demyelination in the corpus callosum. Demyelinated area was diminished in the corpus callosum of cell-administered group. Cuprizone could decrease myelin-binding protein mRNAs expression in corpus callosum, which was significantly recovered after BM-MSCs injections.

Conclusion:

Our data indicated a remyelination potency of multiple i.p. BM-MSCs in the cuprizone model of multiple sclerosis in mice.

Making gametes from alternate sources of stem cells: past, present and future

Infertile couples including cancer survivors stand to benefit from gametes differentiated from embryonic or induced pluripotent stem (ES/iPS) cells. It remains challenging to convert human ES/iPS cells into primordial germ-like cells (PGCLCs) en route to obtaining gametes. Considerable success was achieved in 2016 to obtain fertile offspring starting with mouse ES/iPS cells, however the specification of human ES/iPS cells into PGCLCs in vitro is still not achieved. Human ES cells will not yield patient-specific gametes unless and until hES cells are derived by somatic cell nuclear transfer (therapeutic cloning) whereas iPS cells retain the residual epigenetic memory of the somatic cells from which they are derived and also harbor genomic and mitochondrial DNA mutations. Thus, they may not be ideal starting material to produce autologus gametes, especially for aged couples. Pluripotent, very small embryonic-like stem cells (VSELs) have been reported in adult tissues including gonads, are relatively quiescent in nature, survive oncotherapy and can be detected in aged, non-functional gonads. Being developmentally equivalent to PGCs (natural precursors to gametes), VSELs spontaneously differentiate into gametes in vitro. It is also being understood that gonadal stem cells niche is compromised by oncotherapy and with age. Improving the gonadal somatic niche could regenerate non-functional gonads from endogenous VSELs to restore fertility. Niche cells (Sertoli/mesenchymal cells) can be directly transplanted and restore gonadal function by providing paracrine support to endogenous VSELs. This strategy has been successful in several mice studies already and resulted in live birth in a woman with pre-mature ovarian failure.

Human Mesenchymal Stem Cells Partially Reverse Infertility in Chemotherapy-Induced Ovarian Failure

INTRODUCTION

Chemotherapy is the most commonly used modality to treat human cancers; however, in many cases it causes irreversible ovarian failure. In this work, we plan to evaluate the restorative function of human bone marrow mesenchymal stem cells (BMSCs) in a chemotherapy-induced ovarian failure mouse model.

METHODS

Acclimatized 4 to 6 week-old female mice (C57BL/6) were assigned randomly to a vehicle-treated control group (group 1), chemotherapy-treated group followed by vehicle alone (group 2), or chemotherapy-treated group followed by stem cell intraovarian injection (group 3). Outcomes were evaluated using immunohistochemistry (IHC), serum hormonal assays, and estrous cycle monitoring and breeding potential.

RESULTS

Post BMSCs administration, group 3 promptly showed detectable vaginal smears with estrogenic changes. Increase in total body weight, ovarian weight, and weight of estrogen-responsive organs (uterus and liver) was observed at 2 weeks and continued to end of the experiment. Hematoxylin and Eosin histological evaluation of the ovaries demonstrated a higher mean follicle count in group 3 than in group 2. Group 3 had lower follicle-stimulating hormone (FSH) levels ( P = .03) and higher anti-Müllerian hormone serum (AMH) levels ( P = .0005) than group 2. The IHC analysis demonstrated higher expression of AMH, FSH receptor, inhibin A, and inhibin B in growing follicles of group 3 versus group 2. Tracking studies demonstrated that human BMSCs evenly repopulated the growing follicles in treated ovaries. Importantly, breeding data showed significant increases in the pregnancies numbers, 2 pregnancies in group 1 and 12 in group 3 ( P = .02).

CONCLUSIONS

Intraovarian administered BMSCs are able to restore ovarian hormone production and reactivate folliculogenesis in chemotherapy-induced ovarian failure mouse model.

Human umbilical cord blood-mesenchymal stem cells transplantation renovates the ovarian surface epithelium in a rat model of premature ovarian failure: Possible direct and indirect effects

This study aimed to isolate mesenchymal stem cells (MSC) from human umbilical cord blood (HCB) and to explore their influence on the ovarian epithelium after paclitaxel-induced ovarian failure. Ninety-five rats were divided into 6 groups: control, paclitaxel, paclitaxel and saline, HCB-MSC-treated for 2 weeks, HCB-MSC-treated for 4 weeks, and HCB-MSC-treated for 6 weeks. HCB cells were studied for CD34, CD44, and Oct ¾ using flow cytometry. Serum levels of FSH and E2 were measured using ELISA, RT-PCR analysis for human gene; beta-actin (ACTB), immunohistochemical analysis for CK 8/18, TGF-ß, PCNA and CASP-3 were performed. We found that ACTB gene was expressed in all rats' ovaries received HCB-MSC. After 4 weeks of transplantation, there was significant reduction in FSH, elevation in E2 levels, stabilization of the surface epithelium morphostasis, an increase in the antral follicle count and increase in integrated densities (ID) of CK 8/18, TGF-ß, and PCNA expressions and decrease in ID of CASP-3 expression. We concluded that HCB-MSC can restore the ovarian function after paclitaxel injection through a direct triggering effect on the ovarian epithelium and/or indirect enrichment of ovarian niche through regulating tissue expression of CK 8/18, TGF-ß and PCNA. These molecules are crucial in regulating folliculogenesis and suppressing CASP-3-induced apoptosis.

Human Umbilical Cord Mesenchymal Stem Cells Therapy in Cyclophosphamide-Induced Premature Ovarian Failure Rat Model

Premature ovarian failure (POF) is one of the most common causes of infertility in women. In our present study, we established cyclophosphamide- (CTX-) induced POF rat model and elucidated its effect on ovarian function. We detected the serum estrogen, follicle stimulating hormone, and anti-Müllerian hormone of mice models by ELISA and evaluated their folliculogenesis by histopathology examination. Our study revealed that CTX administration could severely disturb hormone secretion and influence folliculogenesis in rat. This study also detected ovarian cells apoptosis by deoxy-UTP-digoxigenin nick end labeling (TUNEL) and demonstrated marked ovarian cells apoptosis in rat models following CTX administration. In order to explore the potential of human umbilical cord mesenchymal stem cells (UCMSCs) in POF treatment, the above indexes were used to evaluate ovarian function. We found that human UCMSCs transplantation recovered disturbed hormone secretion and folliculogenesis in POF rat, in addition to reduced ovarian cell apoptosis. We also tracked transplanted UCMSCs in ovaries by fluorescence in situ hybridization (FISH). The results manifested that the transplanted human UCMSCs could reside in ovarian tissues and could survive for a comparatively long time without obvious proliferation. Our present study provides new insights into the great clinical potential of human UCMSCs in POF treatment.

VSELs may obviate cryobanking of gonadal tissue in cancer patients for fertility preservation

Background

Infertility is an undesirable side effect and gonadal tissue banking is advocated in young cancer patients who are unable to preserve embryos or gametes prior to oncotherapy to achieve biological parenthood later on. Banking gonadal tissue is challenging and protocols to mature gametes in vitro are not yet clinically established. Transplanting ovarian cortical tissue at hetero-or orthotopic sites in women and bone marrow transplantation (BMT) in both men and women has resulted in spontaneous recovery of fertility, pregnancy and live births. Various studies in humans and mice suggest that genetic origin of offspring after BMT is similar to transplanted patient and not the donor. Thus the source of oocytes/sperm which result in spontaneous pregnancies still remains contentious.

Findings

Very small embryonic-like stem cells (VSELs) have been reported in adult human testis and ovary, in azoospermic testicular biopsies from survivors of childhood cancer and also in women with premature ovarian failure and menopause. VSELs survive chemotherapy because of their quiescent nature and can be detected in chemoablated mice gonads at protein and mRNA level and also by flow cytometry. Surviving VSELs spontaneously differentiate into oocyte-like structures and sperm when inhibitory factors are overcome in vitro. Transplantation of mesenchymal cells (isolated from different sources) has led to regeneration of chemoablated mouse gonads and also live births. Spermatogenesis is also restored from endogenous stem cells on inter-tubular transplantation of Sertoli cells in chemoablated mouse testis.

Conclusions

Endogenous VSELs (which survive oncotherapy) can possibly regenerate non-functional gonads in cancer survivors when exposed to a healthy niche in vitro or in vivo (by way of transplanting mesenchymal cells which secrete trophic factors required for endogenous VSELs to differentiate into gametes). Presence of VSELs can also explain spontaneous pregnancies after BMT and cortical tissue transplantation (at heterotopic or orthotopic sites). This understanding once verified and accepted by the scientific community could obviate the need to remove whole ovary or testicular biopsy for cryopreservation prior to oncotherapy.

The Paracrine Effect of Transplanted Human Amniotic Epithelial Cells on Ovarian Function Improvement in a Mouse Model of Chemotherapy-Induced Primary Ovarian Insufficiency

Human amnion epithelial cells (hAECs) transplantation via tail vein has been reported to rescue ovarian function in mice with chemotherapy-induced primary ovarian insufficiency (POI). To test whether intraperitoneally transplanted hAECs could induce therapeutic effect and to characterize the paracrine effect of transplanted hAECs, we utilized a chemotherapy induced mice model of POI and investigated the ability of hAECs and conditioned medium collected from cultured hAECs (hAECs-CM) to restore ovarian function. We found that transplantation of hAECs or hAECs-CM either 24 hours or 7 days after chemotherapy could increase follicle numbers and partly restore fertility. By PCR analysis of recipient mice ovaries, the presence of SRY gene was only detected in mice transplanted with male hAECs 24 hours following chemotherapy. Further, the gene expression level of VEGFR1 and VEGFR2 in the ovaries decreased, although VEGFA increased 2 weeks after chemotherapy. After treatment with hAECs or hAEC-CM, the expression of both VEGFR1 and VEGFR2 increased, consistent with the immunohistochemical analysis. In addition, both hAECs and hAECs-CM treatment enhanced angiogenesis in the ovaries. The results suggested that hAECs-CM, like hAECs, could partly restore ovarian function, and the therapeutic function of intraperitoneally transplanted hAECs was mainly induced by paracrine-mediated ovarian protection and angiogenesis.

Postnatal oogenesis in humans: a review of recent findings

In spite of generally accepted dogma that the total number of follicles and oocytes is established in human ovaries during the fetal period of life rather than forming de novo in adult ovaries, some new evidence in the field challenges this understanding. Several studies have shown that different populations of stem cells, such as germinal stem cells and small round stem cells with diameters of 2 to 4 μm, that resembled very small embryonic-like stem cells and expressed several genes related to primordial germ cells, pluripotency, and germinal lineage are present in adult human ovaries and originate in ovarian surface epithelium. These small stem cells were pushed into the germinal direction of development and formed primitive oocyte-like cells in vitro. Moreover, oocyte-like cells were also formed in vitro from embryonic stem cells and induced pluripotent stem cells. This indicates that postnatal oogenesis is not excluded. It is further supported by the occurrence of mesenchymal stem cells that can restore the function of sterilized ovaries and lead to the formation of new follicles and oocytes in animal models. Both oogenesis in vitro and transplantation of stem cell-derived "oocytes" into the ovarian niche to direct their natural maturation represent a big challenge for reproductive biomedicine in the treatment of female infertility in the future and needs to be explored and interpreted with caution, but it is still very important for clinical practice in the field of reproductive medicine.

Homing and restorative effects of bone marrow-derived mesenchymal stem cells on cisplatin injured ovaries in rats

Premature ovarian failure (POF) is a long-term adverse effect of chemotherapy treatment. However, current available treatment regimens are not optimal. Emerging evidence suggests that bone marrow-derived mesenchymal stem cells (BMSCs) could restore the structure and function of injured tissues, but the homing and restorative effects of BMSCs on chemotherapy injured ovaries are still not clear. In this study, we found that granulosa cell (GC) apoptosis induced by cisplatin was reduced when BMSCs were migrated to granulosa cells (GCs) in vitro. Chemotherapy-induced POF was induced by intraperitoneal injection of cisplatin in rats. BMSCs labeled with enhanced green fluorescent protein (EGFP) were injected into the rats via the tail vein to investigate the homing and distribution of BMSCs in vivo. The number of BMSCs in the ovarian hilum and medulla was greater than in the cortex, but no BMSCs were found in the follicles and corpus lutea. In addition, the BMSCs treatment group's antral follicle count and estradiol levels increased after 30 days, compared with the POF group. Hence, our study demonstrates that intravenously delivered BMSCs can home to the ovaries, and restore its structure and function in POF model rats.

Cell therapy for chemically induced ovarian failure in mice

Cell therapy has been linked to an unexplained return of ovarian function and fertility in some cancer survivors. Studies modeling this in mice have shown that cells transplantation generates donor-derived oocytes in chemotherapy-treated recipients. This study was conducted to further clarify the impact of cell transplantation from different sources on female reproductive function after chemotherapy using a preclinical mouse model. Methods. Female mice were administered 7.5 mg/kg cisplatin followed by cell transplantation (one week later) using GFP+ female cell donors. For cell tracking, adipose derived stem cell GFP+ (ADSC), female germline stem cell GFP+/MVH+ (FGSC), or ovary cell suspension GFP+ mice were transplanted into cisplatin-treated wild-type recipients. After 7 or 14 days animals were killed and histological analysis, IHQ for GFP cells, and ELISA for estradiol were performed. Results. Histological examinations showed that ADSC, ovary cell suspension, and FGSC transplant increase the number of follicles with apparent normal structure in the cells recipient group euthanized on day 7. Cell tracking showed GFP+ samples 7 days after transplant. Conclusion. These data suggest that intraovarian injection of ADSCs and FGSC into mice with chemotherapy-induced ovarian failure diminished the damage caused by cisplatin.

Putative mesenchymal stem cells isolated from adult human ovaries

PURPOSE

The purpose of this study was to show that healthy adult human ovaries can be a source of cells showing typical MSCs characteristics under in vitro conditions.

METHODS AND RESULTS

The cells, which were isolated from ovarian cortex tissue and named putative ovarian mesenchymal stem cells (PO-MSCs), were compared to bone marrow-derived MSCs (BM-MSCs) and to adult human dermal fibroblasts (HDFs). The results of a gene expression analysis using the Human Mesenchymal Stem Cell RT² Profiler™ PCR Array revealed that PO-MSCs were different than fibroblasts. They expressed most of the analyzed genes as BM-MSCs, although some genes were differentially expressed. However, the heterogeneity of PO-MSCs samples was revealed. The PO-MSCs expressed the characteristic genes related to MSCs, such as CD105, CD44, CD90, M-CAM, CD73 and VCAM1. In addition, the expression of markers CD44, CD90, M-CAM and STRO-1 was confirmed in PO-MSCs using immunocytochemistry. The PO-MSCs showed multipotent character, since they were able to differentiate into the cells of adipogenic, osteogenic, neural and pancreatic lineage.

CONCLUSIONS

Healthy adult human ovaries can harbour an interesting population of cells showing typical MSCs characteristics under in vitro conditions and for this reason we named these cells putative MSCs. These cells express genes encoding main MSCs markers and have an interesting differential potential. Based on these results, we propose PO-MSCs as a novel type of MSCs which share some similarities with BM-MSCs. Nevertheless they show distinct and specific characteristics and are not fibroblasts.