Characterization of Mechanical Signature of Eutopic Endometrial Stromal Cells of Endometriosis Patients

The matrix stiffness is increased in the eutopic endometrium of adenomyosis patients: a study based on atomic force microscopy and histochemistry

Previous ultrasound studies suggest that patients with adenomyosis (AM) exhibit increased uterine cavity stiffness, although direct evidence regarding extracellular matrix (ECM) content and its specific impact on endometrial stiffness remains limited. This study utilized atomic force microscopy to directly measure endometrial stiffness and collagen morphology, enabling a detailed analysis of the endometrium's mechanical properties: through this approach, we established direct evidence of increased endometrial stiffness and fibrosis in patients with AM. Endometrial specimens were also stained with Picrosirius red or Masson's trichrome to quantify fibrosis, and additional analyses assessed α-SMA and Ki-67 expression. Studies indicate that pathological conditions significantly influence the mechanical properties of endometrial tissue. Specifically, adenomyotic endometrial tissue demonstrates increased stiffness, associated with elevated ECM and fibrosis content, whereas normal endometrial samples are softer with lower ECM content. AM appears to alter both the mechanical and histological characteristics of the eutopic endometrium. Higher ECM content may significantly impact endometrial mechanical properties, potentially contributing to AM-associated decidualization defects and fertility challenges.

Bioengineering approaches for the endometrial research and application

The endometrium undergoes a series of precise monthly changes under the regulation of dynamic levels of ovarian hormones that are characterized by repeated shedding and subsequent regeneration without scarring. This provides the potential for wound healing during endometrial injuries. Bioengineering materials highlight the faithful replication of constitutive cells and the extracellular matrix that simulates the physical and biomechanical properties of the endometrium to a larger extent. Significant progress has been made in this field, and functional endometrial tissue bioengineering allows an in-depth investigation of regulatory factors for endometrial and myometrial defects in vitro and provides highly therapeutic methods to alleviate obstetric and gynecological complications. However, much remains to be learned about the latest progress in the application of bioengineering technologies to the human endometrium. Here, we summarize the existing developments in biomaterials and bioengineering models for endometrial regeneration and improving the female reproductive potential.

Regulatory mechanism of GPER in the invasion and migration of ectopic endometrial stromal cells in endometriosis

Endometriosis (EMS) is a chronic inflammatory disorder of high incidence that causes serious reproductive consequences. High estrogen production is a consistently observed endocrine feature of EMS. The present study aims to probe the molecular mechanism of G protein-coupled estrogen receptor 1 (GPER) in the invasion and migration of ectopic endometrial stromal cells (Ect-ESCs) and provides a new rationale for EMS treatment. Eutopic and ectopic endometrial tissues were collected from 41 EMS patients, and primary ESCs were separated. GPER, miR-16-5p, and miR-103a-3p levels in cells and tissues were determined by qRT-PCR or Western blot assay. Cell viability, proliferation, invasion, and migration were evaluated by CCK-8, colony formation, and Transwell assays. The upstream miRNAs of GPER were predicted by databases, and dual-luciferase assay was performed to validate the binding of miR-16-5p and miR-103a-3p to GPER 3'UTR. GPER was highly expressed in EMS tissues and Ect-ESCs. Inhibition of GPER mitigated the proliferation, invasion, and migration of Ect-ESCs. GPER was regulated by miR-16-5p and miR-103a-3p. Overexpression of miR-16-5p and miR-103a-3p negatively regulated GPER expression and inhibited the invasion and migration of Ect-ESC. In conclusion, GPER promoted the invasion and migration of Ect-ESCs, which can be reversed by upstream miR-16-5p and miR-103a-3p.

Revolutionizing the female reproductive system research using microfluidic chip platform

Comprehensively understanding the female reproductive system is crucial for safeguarding fertility and preventing diseases concerning women's health. With the capacity to simulate the intricate physio- and patho-conditions, and provide diagnostic platforms, microfluidic chips have fundamentally transformed the knowledge and management of female reproductive health, which will ultimately promote the development of more effective assisted reproductive technologies, treatments, and drug screening approaches. This review elucidates diverse microfluidic systems in mimicking the ovary, fallopian tube, uterus, placenta and cervix, and we delve into the culture of follicles and oocytes, gametes' manipulation, cryopreservation, and permeability especially. We investigate the role of microfluidics in endometriosis and hysteromyoma, and explore their applications in ovarian cancer, endometrial cancer and cervical cancer. At last, the current status of assisted reproductive technology and integrated microfluidic devices are introduced briefly. Through delineating the multifarious advantages and challenges of the microfluidic technology, we chart a definitive course for future research in the woman health field. As the microfluidic technology continues to evolve and advance, it holds great promise for revolutionizing the diagnosis and treatment of female reproductive health issues, thus propelling us into a future where we can ultimately optimize the overall wellbeing and health of women everywhere.

Silencing of circ_0007299 suppresses proliferation, migration, and invasiveness and promotes apoptosis of ectopic endometrial stromal cells in endometriosis via miR-424-5p-dependent modulation of CREB1

BACKGROUND

The abnormality of endometrial stromal cells (ESCs) can contribute to endometriosis pathogenesis. Circular RNAs (circRNAs) possess critical roles in endometriosis pathogenesis. Here, we defined the activity and mechanism of human circ_0007299 in the regulation of ectopic ESCs in vitro.

METHODS

Circ_0007299, miR-424-5p and cAMP response element-binding protein 1 (CREB1) were quantified by qRT-PCR or immunoblotting. Cell viability, proliferation, apoptosis, invasion and motility were gauged by CCK-8, 5-Ethynyl-2'-Deoxyuridine (EdU), flow cytometry, transwell, and wound-healing assays, respectively. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were used to verify the direct relationship between miR-424-5p and circ_0007299 or CREB1.

RESULTS

Our data showed that circ_0007299 was upregulated in human ectopic endometrium tissues and ectopic ESCs. Silencing endogenous circ_0007299 impeded the proliferation, invasiveness, and motility and enhanced apoptosis of ectopic ESCs. Mechanistically, circ_0007299 regulated miR-424-5p expression. Moreover, circ_0007299 silencing impeded the proliferation, invasiveness, and motility and enhanced apoptosis of ectopic ESCs via its regulation on miR-424-5p. CREB1 was identified as a direct miR-424-5p target, and miR-424-5p overexpression suppressed ectopic ESC proliferation, migration, and invasiveness and promoted apoptosis by downregulating CREB1. Furthermore, circ_0007299 positively modulated CREB1 expression through miR-424-5p competition.

CONCLUSION

Our findings establish that circ_0007299 silencing impedes the proliferation, invasiveness, and motility and promotes apoptosis of ectopic ESCs at least in part via miR-424-5p-dependent modulation of CREB1.

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.

How Mechanical Forces Change the Human Endometrium during the Menstrual Cycle in Preparation for Embryo Implantation

The human endometrium is characterized by exceptional plasticity, as evidenced by rapid growth and differentiation during the menstrual cycle and fast tissue remodeling during early pregnancy. Past work has rarely addressed the role of cellular mechanics in these processes. It is becoming increasingly clear that sensing and responding to mechanical forces are as significant for cell behavior as biochemical signaling. Here, we provide an overview of experimental evidence and concepts that illustrate how mechanical forces influence endometrial cell behavior during the hormone-driven menstrual cycle and prepare the endometrium for embryo implantation. Given the fundamental species differences during implantation, we restrict the review to the human situation. Novel technologies and devices such as 3D multifrequency magnetic resonance elastography, atomic force microscopy, organ-on-a-chip microfluidic systems, stem-cell-derived organoid formation, and complex 3D co-culture systems have propelled the understanding how endometrial receptivity and blastocyst implantation are regulated in the human uterus. Accumulating evidence has shown that junctional adhesion, cytoskeletal rearrangement, and extracellular matrix stiffness affect the local force balance that regulates endometrial differentiation and blastocyst invasion. A focus of this review is on the hormonal regulation of endometrial epithelial cell mechanics. We discuss potential implications for embryo implantation.

Determination of damping coefficient of soft tissues using piezoelectric transducer

Measuring viscoelastic properties of soft tissues becomes a new biomarker in the medical diagnosis field. It can help in early diagnosis and related fields, such as minimally-invasive-surgery (MIS) applications and cell mechanics. The current work presents a tactile sensor for measuring the damping coefficient of the soft tissues. The proposed sensor can be miniaturized easily and used in MIS applications. Besides the proposed sensor, a mathematical model, based on Jacobsen's approach, is built to calculate the damping coefficient of the specimens and the surrounding. These damping sources significantly influence the proposed sensor, such as air damping and hysteretic damping. The sensor system principally depends on a piezoelectric transducer, which is cheap, commonly available, and easily integrated into MEMS. To conceptually prove the sensor feasibility, silicon rubber samples with different stiffnesses have been fabricated and tested by the new sensor. The obtained results prove the newly proposed sensor's capability to differentiate the damping coefficients for soft materials effectively.

Evidence of the Extrahepatic Replication of Hepatitis E Virus in Human Endometrial Stromal Cells

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis worldwide. The tropism of HEV is not restricted to the liver, and the virus replicates in other organs. Not all the extrahepatic targets for HEV are identified. Herein, we found that non-decidualized primary human endometrial stromal cells (PHESCs), which are precursors for the decidua and placenta, are susceptible to HEV infection. PHESCs, isolated from healthy non-pregnant women (n = 5), were challenged with stool-derived HEV-1 and HEV-3. HEV RNA was measured by qPCR, and HEV capsid protein was assessed by flow cytometry, immunofluorescence (IF), and ELISA. HEV infection was successfully established in PHESCs. Intracellular and extracellular HEV RNA loads were increased over time, indicating efficient replication in vitro. In addition, HEV capsid protein was detected intracellularly in the HEV-infected PHESCs and accumulated extracellularly over time, confirming the viral assembly and release from the infected cells. HEV-1 replicated more efficiently in PHESCs than HEV-3 and induced more inflammatory responses. Ribavirin (RBV) treatment abolished the replication of HEV in PHESCs. In conclusion, PHESCs are permissive to HEV infection and these cells could be an endogenous source of HEV infection during pregnancy and mediate HEV vertical transmission.