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/.

Transcriptome analysis of adenomyosis eutopic endometrium reveals molecular mechanisms involved in adenomyosis-related implantation failure and pregnancy disorders.

BACKGROUND: Women with adenomyosis are characterized by having defective decidualization, impaired endometrial receptivity and/or embryo-maternal communication, and implantation failure. However, the molecular mechanisms underlying adenomyosis-related infertility remain unknown, mainly because of the restricted accessibility and the difficult preservation of endometrial tissue in vitro. We have recently shown that adenomyosis patient-derived endometrial organoids, maintain disease-specific features while differentiated into mid-secretory and gestational endometrial phase, overcoming these research barriers and providing a robust platform to study adenomyosis pathogenesis and the associated molecular dysregulation related to implantation and pregnancy disorders. For this reason, we aim to characterize the dysregulated mechanisms in the mid-secretory and gestational endometrium of patients with adenomyosis by RNA-sequencing. METHODS: Endometrial organoids were derived from endometrial biopsies collected in the proliferative phase of women with adenomyosis (ADENO) or healthy oocyte donors (CONTROL) (n = 15/group) and differentiated into mid-secretory (-SECorg) and gestational (-GESTorg) phases in vitro. Following RNA-sequencing, the significantly differentially expressed genes (DEGs) (FDR < 0.05) were identified and selected for subsequent functional enrichment analysis and QIAGEN Ingenuity Pathway Analysis (IPA). Statistical differences in gene expression were evaluated with the Student's t-test or Wilcoxon test. RESULTS: We identified 1,430 DEGs in ADENO-SECorg and 1,999 DEGs in ADENO-GESTorg. In ADENO-SECorg, upregulated genes included OLFM1, FXYD5, and RUNX2, which are involved in impaired endometrial receptivity and implantation failure, while downregulated genes included RRM2, SOSTDC1, and CHAC2 implicated in recurrent implantation failure. In ADENO-GESTorg, upregulated CXCL14 and CYP24A1 and downregulated PGR were related to pregnancy loss. IPA predicted a significant inhibition of ID1 signaling, histamine degradation, and activation of HMGB1 and Senescence pathways, which are related to implantation failure. Alternatively, IPA predicted an inhibition of D-myo-inositol biosynthesis and VEGF signaling, and upregulation of Rho pathway, which are related to pregnancy loss and preeclampsia. CONCLUSIONS: Identifying dysregulated molecular mechanisms in mid-secretory and gestational endometrium of adenomyosis women contributes to the understanding of adenomyosis-related implantation failure and/or pregnancy disorders revealing potential therapeutic targets. Following experimental validation of our transcriptomic and in silico findings, our differentiated adenomyosis patient-derived organoids have the potential to provide a reliable platform for drug discovery, development, and personalized drug screening for affected patients.

Extracellular vesicles secreted by adenomyosis endometrial organoids contain miRNAs involved in embryo implantation and pregnancy.

RESEARCH QUESTION: Do extracellular vesicles secreted by the endometrium of women with adenomyosis contain miRNAs involved in adenomyosis-related infertility? DESIGN: A descriptive study using organoids from eutopic endometrium of women with adenomyosis (n = 4) generated and differentiated to secretory and gestational phases, in which miRNA cargo from extracellular vesicles secreted by these differentiated organoids in each phase was analysed by next-generation sequencing. miRNAs in secretory-extracellular vesicles and gestational-extracellular vesicles were selected based on the counts per million. miRNAs target genes in each phase were obtained from miRNet and gene ontology was used for enrichment analysis. RESULTS: miRNA sequencing identified 80 miRNAs in secretory-phase extracellular vesicles, including hsa-miR-21-5p, hsa-miR-24-3p, hsa-miR-26a-5p, hsa-miR-92a-3p, hsa-miR-92b-3p, hsa-miR-200c-3p and hsa-miR-423a-5p, related to adenomyosis pathogenesis and implantation failure. Further, 60 miRNAs were identified in gestational-phase extracellular vesicles, including hsa-miR-21-5p, hsa-miR-26a-5p, hsa-miR-30a-5p, hsa-miR-30c-5p, hsa-miR-222-3p and hsa-miR-423a-5p were associated with preeclampsia and miscarriage. Among the target genes of these miRNAs, PTEN, MDM4, PLAGL2 and CELF1, whose downregulation (P = 0.0003, P < 0.0001, P = 0.0002 and P = 0.0003, respectively) contributes to adenomyosis pathogenesis, and impaired early embryo development, leading to implantation failure and miscarriage, are highlihghted. Further, functional enrichment analyses of the target genes revealed their involvement in cell differentiation, proliferation, apoptosis, cell cycle regulation and response to extracellular stimuli. CONCLUSIONS: Eutopic endometrium in secretory and gestational phase from women with adenomyosis releases extracellular vesicles containing miRNAs involved in adenomyosis progression, impaired embryo implantation and pregnancy complications.

Human Umbilical Cord-Based Therapeutics: Stem Cells and Blood Derivatives for Female Reproductive Medicine.

There are several conditions that lead to female infertility, where traditional or conventional treatments have limited efficacy. In these challenging scenarios, stem cell (SC) therapies have been investigated as alternative treatment strategies. Human umbilical cord (hUC) mesenchymal stem cells (hUC-MSC), along with their secreted paracrine factors, extracts, and biomolecules, have emerged as promising therapeutic alternatives in regenerative medicine, due to their remarkable potential to promote anti-inflammatory and regenerative processes more efficiently than other autologous treatments. Similarly, hUC blood derivatives, such as platelet-rich plasma (PRP), or isolated plasma elements, such as growth factors, have also demonstrated potential. This literature review aims to summarize the recent therapeutic advances based on hUC-MSCs, hUC blood, and/or other plasma derivatives (e.g., extracellular vesicles, hUC-PRP, and growth factors) in the context of female reproductive medicine. We present an in-depth analysis of the principal molecules mediating tissue regeneration, compiling the application of these therapies in preclinical and clinical studies, within the context of the human reproductive tract. Despite the recent advances in bioengineering strategies that sustain delivery and amplify the scope of the therapeutic benefits, further clinical trials are required prior to the wide implementation of these alternative therapies in reproductive medicine.

Endometrial gene expression differences in women with coronavirus disease 2019.

OBJECTIVE: To study the potential effect of coronavirus disease (COVID-19) on the endometrial transcriptome of affected, symptomatic women for the detection of altered gene expression. DESIGN: Pilot study of the endometrial transcriptomes of women manifesting COVID-19 compared with those of women without COVID-19 undergoing hysteroscopic procedures for benign gynecologic disorders using RNA sequencing. SETTING: Hospital and university laboratories. PATIENT(S): Women with (n = 14) and without a COVID-19 (n = 10) diagnosis based on a nasopharyngeal swab analysis using quantitative reverse-transcription polymerase chain reaction. The endometrium of the patients with COVID-19 had previously been tested for severe acute respiratory syndrome coronavirus 2 infection, revealing the absence of the virus in this tissue. INTERVENTION(S): Endometrial biopsy sample collection. MAIN OUTCOMES MEASURE(S): Endometrial gene expression and functional analysis of symptomatic patients with COVID-19 vs. individuals without the infection. RESULT(S): The systemic disease COVID-19 altered endometrial gene expression in 75% of the women, with the patients exhibiting a preponderance of 163 up-regulated (e.g., UTS2, IFI6, IFIH1, and BNIP3) and 72 down-regulated genes (e.g., CPZ, CDH3, and IRF4) (false discovery rate<0.05). A total of 161 dysregulated functions (36 up-regulated and 125 down-regulated) were typically enriched in the endometria of the patients with COVID-19, including up-regulation in pathways involved in the development of immune responses to viruses and cytokine inflammation, reflecting elicitation of a COVID-19 response pathway. CONCLUSION(S): Coronavirus disease 2019 affects endometrial gene expression despite the absence of severe acute respiratory syndrome coronavirus 2 RNA in endometrial tissues.

Bioengineering trends in female reproduction: a systematic review.

BACKGROUND: To provide the optimal milieu for implantation and fetal development, the female reproductive system must orchestrate uterine dynamics with the appropriate hormones produced by the ovaries. Mature oocytes may be fertilized in the fallopian tubes, and the resulting zygote is transported toward the uterus, where it can implant and continue developing. The cervix acts as a physical barrier to protect the fetus throughout pregnancy, and the vagina acts as a birth canal (involving uterine and cervix mechanisms) and facilitates copulation. Fertility can be compromised by pathologies that affect any of these organs or processes, and therefore, being able to accurately model them or restore their function is of paramount importance in applied and translational research. However, innate differences in human and animal model reproductive tracts, and the static nature of 2D cell/tissue culture techniques, necessitate continued research and development of dynamic and more complex in vitro platforms, ex vivo approaches and in vivo therapies to study and support reproductive biology. To meet this need, bioengineering is propelling the research on female reproduction into a new dimension through a wide range of potential applications and preclinical models, and the burgeoning number and variety of studies makes for a rapidly changing state of the field. OBJECTIVE AND RATIONALE: This review aims to summarize the mounting evidence on bioengineering strategies, platforms and therapies currently available and under development in the context of female reproductive medicine, in order to further understand female reproductive biology and provide new options for fertility restoration. Specifically, techniques used in, or for, the uterus (endometrium and myometrium), ovary, fallopian tubes, cervix and vagina will be discussed. SEARCH METHODS: A systematic search of full-text articles available in PubMed and Embase databases was conducted to identify relevant studies published between January 2000 and September 2021. The search terms included: bioengineering, reproduction, artificial, biomaterial, microfluidic, bioprinting, organoid, hydrogel, scaffold, uterus, endometrium, ovary, fallopian tubes, oviduct, cervix, vagina, endometriosis, adenomyosis, uterine fibroids, chlamydia, Asherman's syndrome, intrauterine adhesions, uterine polyps, polycystic ovary syndrome and primary ovarian insufficiency. Additional studies were identified by manually searching the references of the selected articles and of complementary reviews. Eligibility criteria included original, rigorous and accessible peer-reviewed work, published in English, on female reproductive bioengineering techniques in preclinical (in vitro/in vivo/ex vivo) and/or clinical testing phases. OUTCOMES: Out of the 10 390 records identified, 312 studies were included for systematic review. Owing to inconsistencies in the study measurements and designs, the findings were assessed qualitatively rather than by meta-analysis. Hydrogels and scaffolds were commonly applied in various bioengineering-related studies of the female reproductive tract. Emerging technologies, such as organoids and bioprinting, offered personalized diagnoses and alternative treatment options, respectively. Promising microfluidic systems combining various bioengineering approaches have also shown translational value. WIDER IMPLICATIONS: The complexity of the molecular, endocrine and tissue-level interactions regulating female reproduction present challenges for bioengineering approaches to replace female reproductive organs. However, interdisciplinary work is providing valuable insight into the physicochemical properties necessary for reproductive biological processes to occur. Defining the landscape of reproductive bioengineering technologies currently available and under development for women can provide alternative models for toxicology/drug testing, ex vivo fertility options, clinical therapies and a basis for future organ regeneration studies.

Establishment of Adenomyosis Organoids as a Preclinical Model to Study Infertility.

Adenomyosis is related to infertility and miscarriages, but so far there are no robust in vitro models that reproduce its pathological features to study the molecular mechanisms involved in this disease. Endometrial organoids are in vitro 3D models that recapitulate the native microenvironment and reproduce tissue characteristics that would allow the study of adenomyosis pathogenesis and related infertility disorders. In our study, human endometrial biopsies from adenomyosis (n = 6) and healthy women (n = 6) were recruited. Organoids were established and hormonally differentiated to recapitulate midsecretory and gestational endometrial phases. Physiological and pathological characteristics were evaluated by immunohistochemistry, immunofluorescence, qRT-PCR, and ELISA. Secretory and gestational organoids recapitulated in vivo glandular epithelial phenotype (pan-cytokeratin, Muc-1, PAS, Laminin, and Ki67) and secretory and gestational features (α-tubulin, SOX9, SPP1, PAEP, LIF, and 17ßHSD2 expression and SPP1 secretion). Adenomyosis organoids showed higher expression of TGF-ß2 and SMAD3 and increased gene expression of SPP1, PAEP, LIF, and 17ßHSD2 compared with control organoids. Our results demonstrate that organoids derived from endometria of adenomyosis patients and differentiated to secretory and gestational phases recapitulate native endometrial-tissue-specific features and disease-specific traits. Adenomyosis-derived organoids are a promising in vitro preclinical model to study impaired implantation and pregnancy disorders in adenomyosis and enable personalized drug screening.

Decellularization Methods of Ovary in Tissue Engineering.

The ovaries or female gonads are situated in the ovarian fossa of the abdominal cavity. These are paired, almond-shaped organs measuring about 3.5 cm long and 1.5 cm thick and exist out of a central medullary zone and a peripheral cortex that are enclosed in a fibrous capsule called the tunica albuginea. The ovaries serve 2 main functions, the first one being the production of female gametes called oocytes (oogenesis). Interestingly, the number of primary oocytes that reside in the ovary is determined at birth. About 400 oocyte-containing follicles successfully go through all the developmental stages from this limited pool during folliculogenesis throughout the female reproductive life. In this process, primordial follicles grow and advance until forming a mature or Graafian follicle; during ovulation, secondary oocytes are released and the remaining follicular wall collapses and forms the highly vascularized corpus luteum or luteal gland. This ovarian cycle is regulated by several hormones secreted from the adenohypophysis and lasts about 28 days. During this cycle, the ovaries also serve as endocrine glands and produce female sex hormones such as estrogens and progesterone (steroidogenesis), influencing the growth and development of tissues sensitive to these hormones such as the endometrium. Hence, the endometrial cycle goes synchronized with the ovarian cycle.

Bioengineered endometrial hydrogels with growth factors promote tissue regeneration and restore fertility in murine models.

Extracellular matrix (ECM) hydrogels obtained from decellularized tissues are promising biocompatible materials for tissue regeneration. These biomaterials may provide important options for endometrial pathologies such as Asherman's syndrome and endometrial atrophy, which lack effective therapies thus far. First, we performed a proteomic analysis of a decellularized endometrial porcine hydrogel (EndoECM) to describe the specific role of ECM proteins related to regenerative processes. Furthermore, we investigated the ability of a bioengineered system-EndoECM alone or supplemented with growth factors (GFs)-to repair the endometrium in a murine model of endometrial damage. For this model, the uterine horns of female C57BL/6 mice were first injected with 70% ethanol, then four days later, they were treated with: saline (negative control); biotin-labeled EndoECM; or biotin-labeled EndoECM plus platelet-derived GF, basic fibroblast GF, and insulin-like GF 1 (EndoECM+GF). Endometrial regeneration and fertility restoration were evaluated by assessing the number of glands, endometrial area, cell proliferation, neaoangiogenesis, reduction of collagen deposition, and fertility restoration. Interestingly, regenerative effects such as an increased number of endometrial glands, increased area, high cell proliferative index, development of new blood vessels, reduction of collagen deposition, and higher pregnancy rate occurred in mice treated with EndoECM+GF. Thus, a bioengineered system based on EndoECM hydrogel supplemented with GFs may be promising for the clinical treatment of endometrial conditions such as Asherman's syndrome and endometrial atrophy. STATEMENT OF SIGNIFICANCE: In the last years, the bioengineering field has developed new and promising approaches to regenerate tissues or replace damaged and diseased tissues. Bioengineered hydrogels offer an ideal option because these materials can be used not only as treatments but also as carriers of drugs and other therapeutics. The present work demonstrates for the first time how hydrogels derived from pig endometrium loaded with growth factors could treat uterine pathologies in a mouse model of endometrial damage. These findings provide scientific evidence about bioengineered hydrogels based on tissue-specific extracellular matrix offering new options to treat human infertility from endometrial causes such as Asherman's syndrome or endometrial atrophy.

5-aza-2'-deoxycitidine inhibits cell proliferation, extracellular matrix formation and Wnt/ß-catenin pathway in human uterine leiomyomas.

BACKGROUND: Uterine leiomyoma is a benign tumor with unclear pathogenesis and inaccurate treatment. This tumor exhibits altered DNA methylation related to disease progression. DNMT inhibitors as 5-aza-2'-deoxycytidine (5-aza-CdR), have been suggested to treat tumors in which DNA methylation is altered. We aimed to evaluate whether DNA methylation reversion with 5-aza-CdR reduces cell proliferation and extracellular matrix (ECM) formation in uterine leiomyoma cells to provide a potential treatment option. METHODS: Prospective study using uterine leiomyoma and adjacent myometrium tissues and human uterine leiomyoma primary (HULP) cells (n = 16). In tissues, gene expression was analyzed by qRT-PCR and DNMT activity by ELISA. Effects of 5-aza-CdR treatment on HULP cells were assessed by CellTiter, western blot, and qRT-PCR. RESULTS: DNMT1 gene expression was higher in uterine leiomyoma vs myometrium. Similarly, DNMT activity was greater in uterine leiomyoma and HULP cells (6.5 vs 3.8 OD/h/mg; 211.3 vs 63.7 OD/h/mg, respectively). After 5-aza-CdR treatment on HULP cells, cell viability was reduced, significantly so at 10 µM (85.3%). Treatment with 10 µM 5-aza-CdR on HULP cells significantly decreased expression of proliferation marker PCNA (FC = 0.695) and of ECM proteins (COLLAGEN I FC = 0.654; PAI-1, FC = 0.654; FIBRONECTIN FC = 0.733). 5-aza-CdR treatment also decreased expression of Wnt/ß-catenin pathway final targets, including WISP1 protein expression (10 µM, FC = 0.699), c-MYC gene expression (2 µM, FC = 0.745 and 10 µM, FC = 0.728), and MMP7 gene expression (5 µM, FC = 0.520 and 10 µM, FC = 0.577). CONCLUSIONS: 5-aza-CdR treatment inhibits cell proliferation, ECM formation, and Wnt/ß-catenin signaling pathway targets in HULP cells, suggesting that DNA methylation inhibition is a viable therapeutic target in uterine leiomyoma.

Strategies for managing Asherman's syndrome and endometrial atrophy: Since the classical experimental models to the new bioengineering approach.

Endometrial function is essential for embryo implantation and pregnancy, but managing endometrial thickness that is too thin to support pregnancy or an endometrium of compromised functionality due to intrauterine adhesions is an ongoing challenge in reproductive medicine. Here, we review current and emerging therapeutic and experimental options for endometrial regeneration with a focus on animal models used to study solutions for Asherman's syndrome and endometrial atrophy, which both involve a damaged endometrium. A review of existing literature was performed that confirmed the lack of consensus on endometrial therapeutic options, though promising new alternatives have emerged in recent years (platelet-rich plasma, exosomes derived from stem cells, bioengineering-based techniques, endometrial organoids, among others). In the future, basic research using established experimental models of endometrial pathologies (combined with new high-tech solutions) and human clinical trials with large population sizes are needed to evaluate these emerging and new endometrial therapies.

Stem Cells and the Endometrium: From the Discovery of Adult Stem Cells to Pre-Clinical Models.

Adult stem cells (ASCs) were long suspected to exist in the endometrium. Indeed, several types of endometrial ASCs were identified in rodents and humans through diverse isolation and characterization techniques. Putative stromal and epithelial stem cell niches were identified in murine models using label-retention techniques. In humans, functional methods (clonogenicity, long-term culture, and multi-lineage differentiation assays) and stem cell markers (CD146, SUSD2/W5C5, LGR5, NTPDase2, SSEA-1, or N-cadherin) facilitated the identification of three main types of endogenous endometrial ASCs: stromal, epithelial progenitor, and endothelial stem cells. Further, exogenous populations of stem cells derived from bone marrow may act as key effectors of the endometrial ASC niche. These findings are promoting the development of stem cell therapies for endometrial pathologies, with an evolution towards paracrine approaches. At the same time, promising therapeutic alternatives based on bioengineering have been proposed.

Stem cell-secreted factor therapy regenerates the ovarian niche and rescues follicles.

BACKGROUND: Ovarian senescence is a normal age-associated phenomenon, but increasingly younger women are affected by diminished ovarian reserves or premature ovarian insufficiency. There is an urgent need for developing therapies to improve ovarian function in these patients. In this context, previous studies suggest that stem cell-secreted factors could have regenerative properties in the ovaries. OBJECTIVE: This study aimed to test the ability of various human plasma sources, enriched in stem cell-secreted factors, and the mechanisms behind their regenerative properties, to repair ovarian damage and to promote follicular development. STUDY DESIGN: In the first phase, the effects of human plasma enriched in bone marrow stem cell soluble factors by granulocyte colony-stimulating factor mobilization, umbilical cord blood plasma, and their activated forms on ovarian niche, follicle development, and breeding performance were assessed in mouse models of chemotherapy-induced ovarian damage (n=7 per group). In addition, the proteomic profile of each plasma was analyzed to find putative proteins and mechanism involved in their regenerative properties in ovarian tissue. In the second phase, the most effective plasma treatment was validated in human ovarian cortex xenografted in immunodeficient mice (n=4 per group). RESULTS: Infusion of human plasma enriched bone marrow stem cell soluble factors by granulocyte colony-stimulating factor mobilization or of umbilical cord blood plasma-induced varying degrees of microvessel formation and cell proliferation and reduced apoptosis in ovarian tissue to rescue follicular development and fertility in mouse models of ovarian damage. Plasma activation enhanced these effects. Activated granulocyte colony-stimulating factor plasma was the most potent inducing ovarian rescue in both mice and human ovaries, and proteomic analysis indicated that its effects may be mediated by soluble factors related to cell cycle and apoptosis, gene expression, signal transduction, cell communication, response to stress, and DNA repair of double-strand breaks, the most common form of age-induced damage in oocytes. CONCLUSION: Our findings suggested that stem cell-secreted factors present in both granulocyte colony-stimulating factor-mobilized and umbilical cord blood plasma could be an effective treatment for increasing the reproductive outcomes in women with impaired ovarian function owing to several causes. The activated granulocyte colony-stimulating factor plasma, which is already enriched in both stem cell-secreted factors and platelet-enclosed growth factors, seems to be the most promising treatment because of its most potent restorative effects on the ovary together with the autologous source.

Comparison of different sources of platelet-rich plasma as treatment option for infertility-causing endometrial pathologies.

OBJECTIVE: To study the effect of human plasma from different sources, namely, umbilical cord blood and adult blood platelet-rich plasma (PRP), on the regeneration of endometrial damage. DESIGN: Composition analysis, in vitro approaches, and a preclinical murine model using plasma to promote endometrial regeneration. SETTING: Hospital and university laboratories. PATIENT(S)/ANIMAL(S): Adult plasma from four Asherman syndrome/endometrial atrophy patients and one fertile woman, commercial umbilical cord plasma, and uterine-damaged NOD/SCID mice model were used. INTERVENTION(S): Endometrial stromal cells from primary culture and an endometrial stem cell line were cultured in vitro, and uterine-damaged NOD/SCID mice were treated with plasma samples from several origins. MAIN OUTCOME MEASURE(S): To investigate the possible beneficial effects of PRP from Asherman syndrome/endometrial atrophy patients. To test if plasma from human umbilical cord blood had a stronger effect than adult PRP in endometrial regeneration. To demonstrate if PRP from Asherman syndrome/endometrial atrophy patients was as effective as PRP from a healthy woman and could therefore be used for autologous treatment. RESULT(S): All plasma samples contained molecules with a high potential for regeneration (stem cell factor, platelet-derived growth factor BB, thrombospondin-1, von Willebrand factor). Furthermore, the highest increase in in vitro proliferation and migration rate was found when endometrial stromal cells were treated with umbilical cord plasma; adult PRP also revealed a significant increment. In the mouse model, a higher expression of Ki67 and Hoxa10 in the endometrium was detected after applying adult PRP, and the proteomic analysis revealed a specific protein expression profile depending on the treatment. The damaged uterine tissue showed more proregenerative markers after applying umbilical cord plasma (Stat5a, Uba3, Thy1) compared with the other treatments (nonactivated umbilical cord plasma, activated adult PRP, and no treatment). CONCLUSION(S): Human PRP possesses regeneration properties usable for endometrial pathologies. Besides that, these regenerative effects seem to be more apparent when the source of obtaining is umbilical cord blood.

Vitamin D as an effective treatment in human uterine leiomyomas independent of mediator complex subunit 12 mutation.

OBJECTIVE: To study whether vitamin D (VitD) inhibits cell proliferation and Wnt/ß-catenin and transforming growth factor-ß (TGFß) signaling pathways in uterine leiomyomas independent of mediator complex subunit 12 (MED12) mutation status. DESIGN: Prospective study comparing leiomyoma vs. myometrial tissues and human uterine leiomyoma primary (HULP) cells treated with or without VitD and analyzed by MED12 mutation status. SETTING: Hospital and university laboratories. PATIENT(S): Women with uterine leiomyoma without any treatment (n = 37). INTERVENTION(S): Uterine leiomyoma and myometrium samples were collected from women undergoing surgery because of symptomatic leiomyoma pathology. MAIN OUTCOME MEASURE(S): Analysis of Wnt/ß-catenin and TGFß pathways and proliferation by quantitative real-time polymerase chain reaction in leiomyoma and myometrial tissue as well as in VitD-treated HULP cells analyzed by Sanger sequencing. RESULTS: Sequencing data showed that 46% of leiomyomas presented MED12 mutation, whereas no mutations were detected in adjacent myometrium. Expression of Wnt/ß-catenin and TGFß pathway genes was significantly increased in MED12-mutated leiomyomas compared to matched myometrium; no significant differences were found in wild-type (WT) leiomyomas. In HULP cells, VitD significantly decreased PCNA expression of both MED12-mutated and WT groups. VitD treatment decreased WNT4 and ß-catenin expression in both groups compared to controls, with significance for WNT4 expression in MED12-mutated samples. Similarly, VitD significantly inhibited TGFß3 expression in cells from both groups. MMP9 expression also decreased. CONCLUSION: Despite molecular differences between MED12-mutated and WT leiomyomas, VitD inhibited Wnt/ß-catenin and TGFß pathways in HULP cells, suggesting VitD as an effective treatment to reduce proliferation and extracellular matrix formation in different molecular subtypes of uterine leiomyomas.

Microphysiological Modeling of the Human Endometrium.

Since the beginning of clinical medicine, the human uterus has held the fascination of clinicians and researchers, given its critical role in the reproduction of our species. The endometrial lining provides residence for the embryo; however, this symbiotic interaction can be disrupted if the timing is not correct and the endometrium is not receptive. Diseases associated with the endometrium interfere with the reproductive process and cause a life-altering burden of pain and even death. With the advancement of technologies and new insights into the biology of the endometrium, much has been uncovered about the dynamic and essential changes that need to occur for normal endometrial function, as well as aberrations that lead to endometrial diseases. As expected, the more that is uncovered, the more the complexity of the endometrium is made evident. In this study, we bring together three areas of scientific advancement that remain in their infancy, but which together have the potential to mirror this complexity and enable understanding. Studies on induced pluripotent stem cells, three-dimensional tissue mimics, and microfluidic culture platforms will be reviewed with a focus on the endometrium. These unconventional approaches will provide new perspectives and appreciation for the elegance and complexity of the endometrium. Impact statement The ability of the human endometrium to regenerate on a monthly basis for ∼4 decades of reproductive years exemplifies its complexity as well as its susceptibility to disease. Restrictions on the types of research that can be done in the human endometrium motivate the development of new technologies and model systems. The three areas of technological advancement reviewed here-induced pluripotent stem cells, three-dimensional model systems, and microfluidic culture systems-will highlight some of the tools that can be applied to studying the human endometrium in ways that have not been done before.

Long-term vitamin D treatment decreases human uterine leiomyoma size in a xenograft animal model.

OBJECTIVE: To study the effects of short- and long-term vitamin D treatment on uterine leiomyomas in vivo through cell proliferation, extracellular matrix (ECM) degradation, and apoptosis. DESIGN: Preclinical study of human leiomyoma treatment with vitamin D in an nonhuman animal model. SETTING: Hospital and university laboratories. PATIENT(S)/ANIMAL(S): Human leiomyomas were collected from patients and implanted in ovariectomized NOD-SCID mice. INTERVENTION(S): Mice were treated with vitamin D (0.5 µg/kg/d or 1 µg/kg/d) or vehicle for 21 or 60 days. MAIN OUTCOME MEASURE(S): Vitamin D effect in xenograft tissue was assessed by monitoring tumor size (18F-FDG positron-emission tomography/computerized tomography and macroscopic examination), cell proliferation (immunohistochemistry and quantitative real-time polymerase chain reaction [qRT-PCR]), ECM (Western blot), transforming growth factor (TGF) ß3 (qRT-PCR), and apoptosis (Westrn blot and TUNEL). RESULT(S): Short-term treatment with vitamin D did not appear to alter leiomyoma size, based on in vivo monitoring and macroscopic examination. However, long-term high-dose treatment induced a significant reduction in leiomyoma size. Cell proliferation was not decreased in the short term, whereas 1 µg/kg/d vitamin D in the long term significantly reduced proliferation compared with control. Although collagen-I and plasminogen activator inhibitor 1 were not modified by short-term treatment, they were both significantly reduced by long-term high-dose vitamin D. Similarly, long-term high-dose vitamin D significantly reduced TGF-ß3 expression. Finally, apoptosis significantly increased with both short- and long-term high-dose vitamin D treatment. CONCLUSION(S): Long-term vitamin D acts as an antiproliferative, antifibrotic, and proapoptotic therapy that provides a safe, nonsurgical therapeutic option for reducing uterine leiomyoma size without side-effects.

Tissue-specific decellularized endometrial substratum mimicking different physiological conditions influences in vitro embryo development in a rabbit model.

In the last decades, the decellularization (DC) of organs has become an established technique in the field of regenerative medicine to yield complex and vascularized bioscaffolds. Furthermore, it has been demonstrated in vitro that these decellularized scaffolds retain their native tissue-specificity. This is also the case when this tissue-specific extracellular matrix (ECM) is solubilized and used as hydrogels or coatings to create a biomimetic environment. In this study we investigated if this specificity not only remains when applied to distinct tissues but even more, that these differences can be distinguished within the same tissue at different stages of proliferation. To address this question, a sensitive in vitro animal model was used: rabbit embryos at the third day of development were cultured on coatings made from acellular endometrium that was non-proliferating (non-synchronous, NS) and proliferating (synchronous with the embryo, S) and their development was compared. For this, we obtained whole NS and S rabbit uteri and subjected them to an adapted decellularization protocol. The acellular endometrium was carefully separated by microdissection and converted into a pre-gel solution to be used as hydrogels and coatings for in vitro assays. First, the characteristics of these NS and S hydrogels were investigated by proteomic analysis, electron microscopy and gelling kinetics. When used as substrata for day 3 embryos culture, it became apparent that only the acellular ECM from synchronous endometrial coating achieved similar results to the gold standard culture protocols and conditions, possibly because of the slow release of growth factors present in the synchronous/proliferating endometrium. STATEMENT OF SIGNIFICANCE: It has been shown by in vitro culture of stem cells, progenitor cells and primary culture cells that decellularized tissues retain their specific functions and biochemical and structural compositions. The present work demonstrates that using a mild SDS and perfusion based decellularization (DC) protocol not only effectively decellularize whole rabbit uteri, adding to the growing field of reproductive tissue engineering, but more importantly that the differences in the proliferating endometrium are translated after DC. This implies that DC not only retains the interspecificity of tissues but also the intraspecificity of a developing hormonally stimulated tissue. For the first time, we demonstrate that the coating from decellularized synchronous endometrium acts as a biological support for in vitro embryo development, achieving comparable results with the current gold standard that only uses serum-containing media.