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JBRA Assisted Reproduction Aug 2022Endometritis is defined as an infection or inflammation of the endometrium. Endometritis is of two types: acute and chronic. Acute endometritis is the symptomatic acute... (Review)
Review
Endometritis is defined as an infection or inflammation of the endometrium. Endometritis is of two types: acute and chronic. Acute endometritis is the symptomatic acute inflammation of the endometrium, which upon examination with a microscope shows micro-abscess and neutrophil invasion in the superficial endometrium. One of its most common manifestations is postpartum endometritis. Chronic endometritis is a silent disease usually diagnosed on the workup of secondary amenorrhoea and infertility. An important cause of chronic endometritis is tuberculosis, especially in developing nations. Chronic and acute endometritis have been associated with poor reproductive outcomes. Worse outcomes have been reported for individuals with chronic endometritis. This is a scoping review of endometritis and its impact on fertility.
Topics: Endometritis; Endometrium; Female; Fertility; Humans; Infertility; Inflammation
PubMed: 35621273
DOI: 10.5935/1518-0557.20220015 -
International Journal of Women's Health 2019Intrauterine adhesions with symptoms like hypomenorrhea or infertility are known under the term Asherman's syndrome. Although the syndrome has been widely investigated,... (Review)
Review
Intrauterine adhesions with symptoms like hypomenorrhea or infertility are known under the term Asherman's syndrome. Although the syndrome has been widely investigated, evidence of both prevention of the syndrome and the ideal treatment are missing. Understanding the pathogenesis of intrauterine adherences is necessary for the prevention of the formation of intrauterine scarring. Intrauterine adhesions can develop from lesion of the basal layer of the endometrium caused by curettage of the newly pregnant uterus. The syndrome may also occur after hysteroscopic surgery, uterine artery embolization or uterine tuberculosis. For initial diagnosis the less invasive contrast sonohysterography or hysterosalpingography is useful. The final diagnosis is based on hysteroscopy. Magnetic resonance imaging is required in cases with totally obliterated uterine cavity. Intrauterine adherences are classified in accordance with different classification systems based on the hysteroscopic diagnosis of severity and localization of adherences. Classification is necessary for the planning of surgery, information on prognosis and scientific purposes. Surgery is performed in symptomatic patients with either infertility or with painful periods. Intrauterine adherences are divided with a hysteroscope using scissors or a power instrument working from the central part of the uterus to the periphery. Peroperative ultrasonography is useful in an outpatient setting for the prevention of complications. Hysteroscopy with fluoroscopy is a solution in difficult cases. Use of intrauterine devices like balloon catheters or intrauterine contraceptive devices seems to be the preferred methods for the prevention of re-occurrence of adhesions after treatment. Both primary prevention after hysteroscopic surgery or curettage and secondary prevention of new adhesions after adhesiolysis have been investigated. The aim of this review was to summarize the literature on diagnosis, classification, treatment and prevention, based on a literature search with a wide range of search terms.
PubMed: 30936754
DOI: 10.2147/IJWH.S165474 -
Nature Reviews. Endocrinology Dec 2022Each month during a woman's reproductive years, the endometrium undergoes vast changes to prepare for a potential pregnancy. Diseases of the endometrium arise for... (Review)
Review
Each month during a woman's reproductive years, the endometrium undergoes vast changes to prepare for a potential pregnancy. Diseases of the endometrium arise for numerous reasons, many of which remain unknown. These endometrial diseases, including endometriosis, adenomyosis, endometrial cancer and Asherman syndrome, affect many women, with an overall lack of efficient or permanent treatment solutions. The challenge lies in understanding the complexity of the endometrium and the extensive changes, orchestrated by ovarian hormones, that occur in multiple cell types over the period of the menstrual cycle. Appropriate model systems that closely mimic the architecture and function of the endometrium and its diseases are needed. The emergence of organoid technology using human cells is enabling a revolution in modelling the endometrium in vitro. The goal of this Review is to provide a focused reference for new models to study the diseases of the endometrium. We provide perspectives on the power of new and emerging models, from organoids to microfluidics, which have opened up a new frontier for studying endometrial diseases.
Topics: Pregnancy; Female; Humans; Endometrium; Uterine Diseases; Endometriosis; Reproduction
PubMed: 36050476
DOI: 10.1038/s41574-022-00725-z -
International Journal of Environmental... Apr 2022Regenerative medicine combines elements of tissue engineering and molecular biology aiming to support the regeneration and repair processes of damaged tissues, cells and... (Review)
Review
Regenerative medicine combines elements of tissue engineering and molecular biology aiming to support the regeneration and repair processes of damaged tissues, cells and organs. The most commonly used preparation in regenerative medicine is platelet rich plasma (PRP) containing numerous growth factors present in platelet granularities. This therapy is increasingly used in various fields of medicine. This article is a review of literature on the use of PRP in gynecology and obstetrics. There is no doubt that the released growth factors and proteins have a beneficial effect on wound healing and regeneration processes. So far, its widest application is in reproductive medicine, especially in cases of thin endometrium, Asherman's syndrome, or premature ovarian failure (POF) but also in wound healing and lower urinary tract symptoms (LUTS), such as urinary incontinence or recurrent genitourinary fistula auxiliary treatment. Further research is, however, needed to confirm the effectiveness and the possibility of its application in many other disorders.
Topics: Endometrium; Female; Gynecology; Humans; Platelet-Rich Plasma; Pregnancy; Regenerative Medicine; Tissue Engineering
PubMed: 35564681
DOI: 10.3390/ijerph19095284 -
Stem Cell Research & Therapy Jan 2022Numerous treatment strategies have so far been proposed for treating refractory thin endometrium either without or with the Asherman syndrome. Inconsistency in the... (Review)
Review
Numerous treatment strategies have so far been proposed for treating refractory thin endometrium either without or with the Asherman syndrome. Inconsistency in the improvement of endometrial thickness is a common limitation of such therapies including tamoxifen citrate as an ovulation induction agent, acupuncture, long-term pentoxifylline and tocopherol or tocopherol only, low-dose human chorionic gonadotropin during endometrial preparation, aspirin, luteal gonadotropin-releasing hormone agonist supplementation, and extended estrogen therapy. Recently, cell therapy has been proposed as an ideal alternative for endometrium regeneration, including the employment of stem cells, platelet-rich plasma, and growth factors as therapeutic agents. The mechanisms of action of cell therapy include the cytokine induction, growth factor production, natural killer cell activity reduction, Th17 and Th1 decrease, and Treg cell and Th2 increase. Since cell therapy is personalized, dynamic, interactive, and specific and could be an effective strategy. Despite its promising nature, further research is required for improving the procedure and the safety of this strategy. These methods and their results are discussed in this article.
Topics: Cell- and Tissue-Based Therapy; Chorionic Gonadotropin; Endometrium; Female; Gynatresia; Humans; Platelet-Rich Plasma
PubMed: 35090547
DOI: 10.1186/s13287-021-02698-8 -
Annual Review of Cell and Developmental... Oct 2023The uterine lining (endometrium) regenerates repeatedly over the life span as part of its normal physiology. Substantial portions of the endometrium are shed during... (Review)
Review
The uterine lining (endometrium) regenerates repeatedly over the life span as part of its normal physiology. Substantial portions of the endometrium are shed during childbirth (parturition) and, in some species, menstruation, but the tissue is rapidly rebuilt without scarring, rendering it a powerful model of regeneration in mammals. Nonetheless, following some assaults, including medical procedures and infections, the endometrium fails to regenerate and instead forms scars that may interfere with normal endometrial function and contribute to infertility. Thus, the endometrium provides an exceptional platform to answer a central question of regenerative medicine: Why do some systems regenerate while others scar? Here, we review our current understanding of diverse endometrial disruption events in humans, nonhuman primates, and rodents, and the associated mechanisms of regenerative success and failure. Elucidating the determinants of these disparate repair processes promises insights into fundamental mechanisms of mammalian regeneration with substantial implications for reproductive health.
Topics: Female; Animals; Humans; Endometrium; Uterus; Fibrosis; Mammals
PubMed: 37843929
DOI: 10.1146/annurev-cellbio-011723-021442 -
International Journal of Molecular... May 2021Intrauterine adhesion (IUA), and its severe form Asherman syndrome (Asherman's syndrome), is a mysterious disease, often accompanied with severe clinical problems... (Review)
Review
Intrauterine adhesion (IUA), and its severe form Asherman syndrome (Asherman's syndrome), is a mysterious disease, often accompanied with severe clinical problems contributing to a significant impairment of reproductive function, such as menstrual disturbance (amenorrhea), infertility or recurrent pregnancy loss. Among these, its correlated infertility may be one of the most challenging problems. Although there are many etiologies for the development of IUA, uterine instrumentation is the main cause of IUA. Additionally, more complicated intrauterine surgeries can be performed by advanced technology, further increasing the risk of IUA. Strategies attempting to minimize the risk and reducing its severity are urgently needed. The current review will expand the level of our knowledge required to face the troublesome disease of IUA. It is separated into six sections, addressing the introduction of the normal cyclic endometrial repairing process and its abruption causing the formation of IUA; the etiology and prevalence of IUA; the diagnosis of IUA; the classification of IUA; the pathophysiology of IUA; and the primary prevention of IUA, including (1) delicate surgical techniques, such as the use of surgical instruments, energy systems, and pre-hysteroscopic management, (2) barrier methods, such as gels, intrauterine devices, intrauterine balloons, as well as membrane structures containing hyaluronate-carboxymethylcellulose or polyethylene oxide-sodium carboxymethylcellulose as anti-adhesive barrier.
Topics: Endometrium; Female; Humans; Pregnancy; Primary Prevention; Tissue Adhesions; Uterine Diseases; Uterus
PubMed: 34068335
DOI: 10.3390/ijms22105175 -
Cells Oct 2020Female infertility is a global medical condition that can be caused by various disorders of the reproductive system, including premature ovarian failure (POF),... (Review)
Review
Female infertility is a global medical condition that can be caused by various disorders of the reproductive system, including premature ovarian failure (POF), polycystic ovary syndrome (PCOS), endometriosis, Asherman syndrome, and preeclampsia. It affects the quality of life of both patients and couples. Mesenchymal stem cells (MSCs) have received increasing attention as a potential cell-based therapy, with several advantages over other cell sources, including greater abundance, fewer ethical considerations, and high capacity for self-renewal and differentiation. Clinical researchers have examined the therapeutic use of MSCs in female infertility. In this review, we discuss recent studies on the use of MSCs in various reproductive disorders that lead to infertility. We also describe the role of microRNAs (miRNAs) and exosomal miRNAs in controlling MSC gene expression and driving MSC therapeutic outcomes. The clinical application of MSCs holds great promise for the treatment of infertility or ovarian insufficiency, and to improve reproductive health for a significant number of women worldwide.
Topics: Exosome Multienzyme Ribonuclease Complex; Female; Humans; Infertility, Female; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; MicroRNAs; Ovarian Follicle; Primary Ovarian Insufficiency
PubMed: 33050021
DOI: 10.3390/cells9102253 -
Human Reproduction Update Nov 2022To provide the optimal milieu for implantation and fetal development, the female reproductive system must orchestrate uterine dynamics with the appropriate hormones...
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.
Topics: Animals; Female; Humans; Pregnancy; Bioengineering; Embryo Implantation; Genitalia, Female; Reproduction; Uterus
PubMed: 35652272
DOI: 10.1093/humupd/dmac025 -
Human Reproduction Update 2016The existence of stem/progenitor cells in the endometrium was postulated many years ago, but the first functional evidence was only published in 2004. The identification... (Review)
Review
BACKGROUND
The existence of stem/progenitor cells in the endometrium was postulated many years ago, but the first functional evidence was only published in 2004. The identification of rare epithelial and stromal populations of clonogenic cells in human endometrium has opened an active area of research on endometrial stem/progenitor cells in the subsequent 10 years.
METHODS
The published literature was searched using the PubMed database with the search terms 'endometrial stem cells and menstrual blood stem cells' until December 2014.
RESULTS
Endometrial epithelial stem/progenitor cells have been identified as clonogenic cells in human and as label-retaining or CD44(+) cells in mouse endometrium, but their characterization has been modest. In contrast, endometrial mesenchymal stem/stromal cells (MSCs) have been well characterized and show similar properties to bone marrow MSCs. Specific markers for their enrichment have been identified, CD146(+)PDGFRβ(+) (platelet-derived growth factor receptor beta) and SUSD2(+) (sushi domain containing-2), which detected their perivascular location and likely pericyte identity in endometrial basalis and functionalis vessels. Transcriptomics and secretomics of SUSD2(+) cells confirm their perivascular phenotype. Stromal fibroblasts cultured from endometrial tissue or menstrual blood also have some MSC characteristics and demonstrate broad multilineage differentiation potential for mesodermal, endodermal and ectodermal lineages, indicating their plasticity. Side population (SP) cells are a mixed population, although predominantly vascular cells, which exhibit adult stem cell properties, including tissue reconstitution. There is some evidence that bone marrow cells contribute a small population of endometrial epithelial and stromal cells. The discovery of specific markers for endometrial stem/progenitor cells has enabled the examination of their role in endometrial proliferative disorders, including endometriosis, adenomyosis and Asherman's syndrome. Endometrial MSCs (eMSCs) and menstrual blood stromal fibroblasts are an attractive source of MSCs for regenerative medicine because of their relative ease of acquisition with minimal morbidity. Their homologous and non-homologous use as autologous and allogeneic cells for therapeutic purposes is currently being assessed in preclinical animal models of pelvic organ prolapse and phase I/II clinical trials for cardiac failure. eMSCs and stromal fibroblasts also exhibit non-stem cell-associated immunomodulatory and anti-inflammatory properties, further emphasizing their desirable properties for cell-based therapies.
CONCLUSIONS
Much has been learnt about endometrial stem/progenitor cells in the 10 years since their discovery, although several unresolved issues remain. These include rationalizing the terminology and diagnostic characteristics used for distinguishing perivascular stem/progenitor cells from stromal fibroblasts, which also have considerable differentiation potential. The hierarchical relationship between clonogenic epithelial progenitor cells, endometrial and decidual SP cells, CD146(+)PDGFR-β(+) and SUSD2(+) cells and menstrual blood stromal fibroblasts still needs to be resolved. Developing more genetic animal models for investigating the role of endometrial stem/progenitor cells in endometrial disorders is required, as well as elucidating which bone marrow cells contribute to endometrial tissue. Deep sequencing and epigenetic profiling of enriched populations of endometrial stem/progenitor cells and their differentiated progeny at the population and single-cell level will shed new light on the regulation and function of endometrial stem/progenitor cells.
Topics: Animals; Biomarkers; Cell Differentiation; Endometriosis; Endometrium; Female; Humans; Mesenchymal Stem Cells; Phenotype; Stem Cells; Uterine Diseases
PubMed: 26552890
DOI: 10.1093/humupd/dmv051