Expression of glycodelin and cyclooxygenase-2 in human endometrial tissue following three-dimensional culture

The Comparative Invasiveness of Endometriotic Cell Lines to Breast and Endometrial Cancer Cell Lines

Endometriosis is an invasive condition that affects 10% of women (and people assigned as female at birth) worldwide. The purpose of this study was to characterize the relative invasiveness of three available endometriotic cell lines (EEC12Z, iEc-ESCs, tHESCs) to cancer cell lines (MDA-MB-231, SW1353 and EM-E6/E7/TERT) and assess whether the relative invasiveness was consistent across different invasion assays. All cell lines were subjected to transwell, spheroid drop, and spheroid-gel invasion assays, and stained for vimentin, cytokeratin, E-Cadherin and N-Cadherin to assess changes in expression. In all assays, endometriotic cell lines showed comparable invasiveness to the cancer cell lines used in this study, with no significant differences in invasiveness identified. EEC12Z cells that had invaded within the assay periods showed declines in E-Cadherin expression compared to cells that had not invaded within the assay period, without significant changes in N-Cadherin expression, which may support the hypothesis that an epithelial-to-mesenchymal transition is an influence on the invasiveness shown by this peritoneal endometriosis cell line.

Strategies for modelling endometrial diseases

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.

Stem Cell Therapy in Limb Ischemia: State-of-Art, Perspective, and Possible Impacts of Endometrial-Derived Stem Cells

As an evidence-based performance, the rising incidence of various ischemic disorders has been observed across many nations. As a result, there is a growing need for the development of more effective regenerative approaches that could serve as main therapeutic strategies for the treatment of these diseases. From a cellular perspective, promoted complex inflammatory mechanisms, after inhibition of organ blood flow, can lead to cell death in all tissue types. In this case, using the stem cell technology provides a safe and regenerative approach for ischemic tissue revascularization and functional cell formation. Limb ischemia (LI) is one of the most frequent ischemic disease types and has been shown to have a promising regenerative response through stem cell therapy based on several clinical trials. Bone marrow-derived mononuclear cells (BM-MNCs), peripheral blood CD34-positive mononuclear cells (CD34+ PB-MNCs), mesenchymal stem cells (MSCs), and endothelial stem/progenitor cells (ESPCs) are the main, well-examined stem cell types in these studies. Additionally, our investigations reveal that endometrial tissue can be considered a suitable candidate for isolating new safe, effective, and feasible multipotent stem cells for limb regeneration. In addition to other teams’ results, our in-depth studies on endometrial-derived stem cells (EnSCs) have shown that these cells have translational potential for limb ischemia treatment. The EnSCs are able to generate diverse types of cells which are essential for limb reconstruction, including endothelial cells, smooth muscle cells, muscle cells, and even peripheral nervous system populations. Hence, the main object of this review is to present stem cell technology and evaluate its method of regeneration in ischemic limb tissue.

Development of A 3D Tissue Slice Culture Model for the Study of Human Endometrial Repair and Regeneration

The human endometrium undergoes sequential phases of shedding of the upper functionalis zone during menstruation, followed by regeneration of the functionalis zone from the remaining basalis zone cells, and secretory differentiation under the influence of the ovarian steroid hormones estradiol (E2) and progesterone (P4). This massive tissue regeneration after menstruation is believed to arise from endometrial stromal and epithelial stem cells residing in the basal layer of the endometrium. Although many endometrial pathologies are thought to be associated with defects in these stem cells, studies on their identification and regulation are limited, primarily due to lack of easily accessible animal models, as these processes are unique to primates. Here we describe a robust new method to study endometrial regeneration and differentiation processes using human endometrial tissue slice cultures incorporating an air-liquid interface into a 3D matrix scaffold of type I collagen gel, allowing sustained tissue viability over three weeks. The 3D collagen gel-embedded endometrial tissue slices in a double-dish culture system responded to ovarian steroid hormones, mimicking the endometrial changes that occur in vivo during the menstrual cycle. These changes included the E2-induced upregulation of Ki-67, estrogen receptor (ER), and progesterone receptor (PR) in all endometrial compartments and were markedly suppressed by both P4 and E2 plus P4 treatments. There were also distinct changes in endometrial morphology after E2 and P4 treatments, including subnuclear vacuolation and luminal secretions in glands as well as decidualization of stromal cells, typical characteristics of a progestational endometrium in vivo. This long-term slice culture method provides a unique in vivo-like microenvironment for the study of human endometrial functions and remodeling during early pregnancy and experiments on stem cell populations involved in endometrial regeneration and remodeling. Furthermore, this model has the potential to enable studies on several endometrial diseases, including endometrial cancers and pregnancy complications associated with defects in endometrial remodeling.

In-vitro models of human endometriosis

Endometriosis is one of the most common benign gynecological diseases in women of reproductive age worldwide. In past decades, a number of in-vitro models have been used to investigate the pathology and therapeutic methods for the treatment of endometriosis. The current review summarized the majority of currently available in-vitro models, which utilize a variety of cell or tissues types, including endometriotic cell lines, primary endometrial stromal cells, endometrial stem cells, endometrial explants, peritoneal explants and immune cells. These cells or tissues are cultured individually, co-cultured in 2D or 3D systems with various matrices or cultured in chicken chorioallantotic membranes and amniotic membranes culture systems. These models are able to represent one or more aspects of the process of endometriosis. These models are helpful and can be used to investigate the development of endometriosis and the underlying mechanisms of this disorder in detail, and help investigators select appropriate models for their experiments. Recently, the new concept of endometriosis as a fibrotic condition will lead research to investigate the differentiation of myofibroblasts and the development of fibrosis in endometriotic lesions, which will increase the development of novel models that can be used to investigate endometriotic fibrosis.

Relevant human tissue resources and laboratory models for use in endometriosis research

Endometriosis is characterized by the growth of endometrium‐like tissue outside the uterus, most commonly on the pelvic peritoneum and ovaries. Although it may be asymptomatic in some women, in others it can cause debilitating pain, infertility or other symptoms including fatigue. Current research is directed both at understanding the complex etiology and pathophysiology of the disorder and at the development of new nonsurgical approaches to therapy that lack the unwanted side effects of current medical management. Tools for endometriosis research fall into two broad categories; patient‐derived tissues, and fluids (and cells isolated from these sources) or models based on the use of cells or animals. In this review, we discuss the literature that has reported data from the use of these tools in endometriosis research and we highlight the strengths and weaknesses of each. Although many different models are reported in the literature, hypothesis‐driven research will only be facilitated with careful experimental design and selection of the most appropriate human tissue from patients with and without endometriosis and combinations of physiologically relevant in vitro and in vivo laboratory models.

BMP-2 can promote the osteogenic differentiation of human endometrial stem cells

Background: Human endometrial-derived stem cells (hEnSCs) as multipotent accessible source of cells are known as useful cell candidates in the field of bone tissue engineering. However, the effect of bone morphogenic protein-2 (BMP-2) as an osteoinductive growth factor has not been clearly ascertained.

Objective: To evaluate the effect of the remarkable osteoinductive growth factor BMP-2, on promotion of osteogenic differentiation in hEnSCs.

Methods: Endometrial biopsies were obtained from healthy women referred to the hospital for infertility treatment. After tissue digestion in collagenase, the isolated endometrial cells were expanded in Dulbecco’s modified Eagle medium (DMEM) supplemented with 10% FBS. The propagated cells were characterized based on the expression of endometrial (CD90, CD105), endothelial (CD31), and hematopoietic (CD34, CD133) stem cell markers. Cells were differentiated in osteogenic medium containing DMEM supplemented with 10% FBS, 10 nM dexamethasone, 50 μg/ml Ascorbic acid, and 10 mM β-glycerophosphate in the presence or absence of BMP-2 for 21 days. Alizarin red staining was performed to verify the matrix mineralization. Immunocytochemical staining was conducted to detect the expression of OCT-4, CD133, and osteopontin as well as osteocalcin. The expression of osteoblast transcripts, including osteopontin, osteonectin, and alkaline phosphatase (ALP) were analyzed by semi quantitative PCR.

Results: The expanded EnSCs were spindle shaped. They were positive for the expression of Oct-4, CD90, and CD105, while they were negative for endothelial and hematopoietic markers. The matrix mineralization was confirmed by Alizarin red in both groups at day 21. Although the expression of osteopontin and osteocalcin was detected in both groups by immunological staining, the expression of osteocalcin was more intense in the presence of BMP-2. ALP, Osteonectin and osteopontin transcripts were expressed in all groups; however, the expression of ALP and osteopontin was upregulated in the presence of BMP-2.

Conclusion: BMP-2 as an osteoinductive growth factor, could promote the osteogenic differentiation of EnSCs in vitro.

The Role of Stem Cells in the Treatment of Cerebral Palsy: a Review

Cerebral palsy (CP) is a neuromuscular disease due to injury in the infant's brain. The CP disorder causes many neurologic dysfunctions in the patient. Various treatment methods have been used for the management of CP disorder. However, there has been no absolute cure for this condition. Furthermore, some of the procedures which are currently used for relief of symptoms in CP cause discomfort or side effects in the patient. Recently, stem cell therapy has attracted a huge interest as a new therapeutic method for treatment of CP. Several investigations in animal and human with CP have demonstrated positive potential of stem cell transplantation for the treatment of CP disorder. The ultimate goal of this therapeutic method is to harness the regenerative capacity of the stem cells causing a formation of new tissues to replace the damaged tissue. During the recent years, there have been many investigations on stem cell therapy. However, there are still many unclear issues regarding this method and high effort is needed to create a technology as a perfect treatment. This review will discuss the scientific background of stem cell therapy for cerebral palsy including evidences from current clinical trials.

The Impact of Endometriosis across the Lifespan of Women: Foreseeable Research and Therapeutic Prospects

In addition to estrogen dependence, endometriosis is characterized by chronic pelvic inflammation. The impact of the chronic pelvic inflammatory state on other organ systems and women's health is unclear. Endometriosis associated chronic inflammation and potential adverse health effects across the lifespan render it imperative for renewed research vigor into the identification of novel biomarkers of disease and therapeutic options. Herein we propose a number of opportunities for research and development of new therapeutics to address the unmet needs in the treatment of endometriosis per se and its ancillary risks for other diseases in women across the lifespan.

The role of placental protein 14 in the pathogenesis of endometriosis

Placental protein 14 (PP-14) is the principal secretory phase product of endometrium and has been shown to inhibit cell immune function. But its role in the pathogenesis of endometriosis is controversy. The objective of this study is to determine the concentrations of PP-14 in peritoneal fluid (PF) and serum and PP-14 protein expression in endometriotic lesions in women with ovarian endometriosis (n = 75) when compared to women without endometriosis (n = 49) between day 7 and day 20 of their menstrual cycle. Concentrations of PP-14 in PF and serum as well as PP-14 protein expression in endometriotic lesions in women with and without endometriosis were evaluated by using enzyme-linked immunosorbent assay and immunohistochemical staining, respectively. Serum PP-14 concentrations were significantly increased in women with endometriosis (7.5 ± 1.4 ng/mL) compared to those in women without endometriosis (5.8 ± 0.9 ng/mL; P < .05) and statistically decreased after surgery and further reduced by using gonadotropin-releasing hormone agonist therapy (P < .05). However, the concentrations of PP-14 in PF did not reach a significant difference between women with and without endometriosis (P > .05). In women with endometriosis, scores of PP-14 protein expression in the lesions (n = 50, 2.2 [0~5.8]) were significantly correlated with serum PP-14 concentrations (n = 50, 7.6 ± 1.3 ng/mL; P < .01). Our results suggest that PP-14 may play an important role in the pathogenesis of endometriosis.

Effect of a dienogest for an experimental three-dimensional endometrial culture model for endometriosis

The pathogenesis of endometriosis remains poorly understood at least in part because early stages of the disease process are difficult to investigate. Previous studies have proposed a three-dimensional fibrin matrix culture model to study human endometriosis. We examined the ultrastructural features of the endometriosis in this model and assessed the effect of a progestin on endometrial outgrowth and apoptosis in this culture system. Endometrial explants were placed in three-dimensional fibrin matrix culture and treated with and without various concentrations of the progestin dienogest. By the second week, endometrial gland-like formation was established in outgrowths both attached to and at a distance from the explants. These cells formed a combination of clumps and tubular monolayers surrounding a central cavity. Electron microscopy demonstrated that these cells are polarized with microvilli on the apical surface, desmosome-like structures, and basement membrane; features consistent with glandular epithelial cells. Outgrowth of endometrial stromal cells and glandular formation was impaired in response to dienogest in a dose-dependent manner. Our study shows that the human endometrial explants cultured in three-dimensional fibrin matrix establish outgrowths that ultrastructurally resemble ectopic endometrial implants. This model may provide insight into the cellular processes leading to endometriosis formation and enables screening of therapeutic compounds.

Implication of the RAGE-EN-RAGE axis in endometriosis

OBJECTIVE

To investigate the involvement of the receptor gene for advanced glycation (RAGE), its ligand EN-RAGE, and COX-2 in endometriosis.

METHODS

The mRNA and protein expression of the corresponding genes were determined from endometriotic cells from 28 study patients and healthy endometrial stromal cells from 20 controls by semiquantitative RT-PCR and Western blot analysis, respectively, using beta-actin as an invariant control.

RESULTS

The expression of COX-2, RAGE, and EN-RAGE was significantly increased, as evidenced by the significantly greater mRNA and protein expression in the cells of the study patients (P<0.001). Previous treatment for endometriosis did not lessen mRNA and protein expression (P<0.001).

CONCLUSION

Our findings strengthen the hypothesis of an underlying inflammation in the pathophysiology of endometriosis and suggest exploring anti-inflammatory therapies as adjunct treatment.

In vitro effects of atorvastatin on lipopolysaccharide-induced gene expression in endometriotic stromal cells

OBJECTIVE

To investigate the in vitro effects of atorvastatin on lipopolysaccharide (LPS)-induced gene expression in endometrial-endometriotic stromal cells.

DESIGN

In vitro experimental study using flow cytometry, ELISA, semiquantitative reverse transcriptase polymerase chain reaction, and Western blot.

SETTING

Postgraduate Institute of Medical Education and Research.

PATIENT(S)

Twenty-five women undergoing laparoscopy (n = 10) and laparotomy (n = 15).

INTERVENTION(S)

Endometriotic cyst wall (group I) and endometrial biopsy (group II) collection.

MAIN OUTCOME MEASURE(S)

The endometrial-endometriotic stromal cells were isolated from ectopic (group I) and eutopic (group II) endometrium by established methods, cultured, and stimulated with LPS (1 μg/mL), followed by atorvastatin treatment in a time- and dose-dependent manner to investigate the effects of LPS on proliferation (Ki-67) and expression of cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF), receptor for advanced glycation end products (RAGE), extracellular newly identified RAGE binding protein (EN-RAGE), peroxisome proliferator activated receptor-γ (PPAR-γ), and liver X receptor-α (LXR-α) genes in endometrial-endometriotic stromal cells and on levels of insulin-like growth factor binding protein-1 (IGFBP-1) and 17β-E(2) in endometrial-endometriotic stromal cell culture supernatant.

RESULT(S)

Significant inhibition of Ki-67 and LPS-induced expression of inflammatory and angiogenic genes (COX-2, VEGF, RAGE, and EN-RAGE) was observed in atorvastatin-treated endometrial-endometriotic stromal cells. In contrast, a significant dose- and time-dependent increase in expression of anti-inflammatory genes (PPAR-γ and LXR-α) and levels of IGFBP-1 was observed after atorvastatin treatment in both the groups. However, atorvastatin treatment had no effect on 17β-E(2) levels in endometrial/endometriotic stromal cell culture supernatant.

CONCLUSION(S)

The data of the present study provide new insights for the implication of atorvastatin treatment for endometriosis in humans.

Letrozole stimulates the growth of human endometrial explants cultured in three-dimensional fibrin matrix

OBJECTIVE

To investigate the effects of an aromatase inhibitor, letrozole, on the growth of human endometrium in a three-dimensional fibrin matrix model of endometriosis.

DESIGN

Experimental study of human endometrial biopsies in a three-dimensional fibrin matrix culture system.

SETTING

Academic research center.

PATIENT(S)

Eight normal women with benign gynecologic problems.

INTERVENTION(S)

Endometrial biopsy samples were washed, cut into small pieces, and placed between two layers of fibrin gel in the presence or absence of letrozole in the culture medium. Tissue changes were assessed by histological and immunohistochemical staining using an inverted microscope, image analysis, and a semiquantitative scoring system.

MAIN OUTCOME MEASURE(S)

Stromal and epithelial cell outgrowth into the fibrin matrix and angiogenesis comprising endothelial cell invasion of the matrix.

RESULT(S)

Letrozole (0.1 micromol/L, 1 micromol/L, and 10 micromol/L) exerted a significant growth stimulation effect on endometrial tissue in this model.

CONCLUSION(S)

In contrast to our expectations, letrozole stimulated growth of normal human endometrium in an in vitro model of endometriosis. Normal endometrium may respond differently than endometriotic lesions to therapeutic agents. Our findings should be kept in mind when considering future research to explore new clinical treatments for endometriosis.