Inflammatory Cytokine-Induced HIF-1 Activation Promotes Epithelial-Mesenchymal Transition in Endometrial Epithelial Cells

Analysis of cellular responses following interaction with extracellular vesicles derived from HEK293T and human adipose derived stem cells

Extracellular vesicles (EVs), particularly exosomes, are crucial mediators of intercellular communication that influence immune responses, cell proliferation, and angiogenesis. Their therapeutic potential has been explored for the treatment of chronic, non-healing wounds, especially in diabetic patients with chronic inflammation, impaired cellular proliferation, and poor angiogenesis. We investigated the role of exosomes derived from human embryonic kidney 293T (HEK293T) cells and human adipose-derived stem cells (hADSCs) on NIH3T3 fibroblast migration. Exosomes were characterized for size, concentration, and surface markers. Western blotting and scratch assays were used to assess ERK1/2 activation and cell migration. Characterization revealed that HEK293T exosomes were more abundant (3.1 × 10¹¹ ± 4.9 × 10⁹ particles/mL), larger (178 ± 4 nm), and exhibited stronger surface marker protein expression than exosomes from hADSCs (2.4 × 10⁹ ± 4.1 × 10⁸ particles/mL, 153 ± 5 nm). Both types of exosomes significantly enhanced NIH3T3 fibroblast migration with migration indices of 63.2 ± 4.3% and 48.9 ± 2.7% via ERK1/2 signaling, with HEK293T exosomes showing stronger effects because of their higher protein content. Western blot analysis revealed that robust ERK1/2 activation by both exosome types was crucial for fibroblast migration, with scratch assays highlighting their pro-migratory effects. Inhibition of the ERK1/2 pathway significantly reduced migration, with HEK293T exosomes showing a reduction to 9.6 ± 3.2% and hADSC exosomes to 2.6 ± 0.2% when treated with the MEK1/2 inhibitor PD98059. HEK293T exosomes induced more pronounced cell migration, and hADSC exosomes showed improved efficacy under stress, suggesting that both exosome types are promising candidates for targeted regenerative therapies in chronic wound healing.

HIF-1α Promotes Luteinization via NDRG1 Induction in the Human Ovary

Background/Objectives: Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor that plays a crucial role in various physiological and pathological processes of the ovary. However, the timing of HIF-1α expression and its specific biological function in the follicular development of the human ovary remain unclear. Therefore, in this study, we aimed to examine whether HIF-1α and its downstream gene, N-myc downstream-regulated gene 1 (NDRG1), exhibit stage-specific expression during the follicular development process in the human ovary. Methods: We used ovarian tissues from eight women with regular menstrual cycles who were not undergoing hormonal treatment. We investigated HIF-1α and NDRG1 expression and localization using immunohistochemistry. Further, we transfected human ovarian granulosa (KGN) cells with HIF-1α small interfering RNA (siRNA) to investigate the influence of HIF-1α on NDRG1 expression and progesterone synthesis. Results: The immunohistochemical analysis of human ovarian tissues revealed that HIF-1α was localized in the cytoplasm of granulosa cells (GCs) at both the primary and secondary follicular stages. Conversely, in tertiary and later developmental stages, HIF-1α was observed exclusively in the nucleus of GCs. Furthermore, while NDRG1 was not detected in primary follicles, it was present in all GCs beyond the tertiary stage. Notably, transfection of KGN cells with HIF-1α siRNA significantly decreased NDRG1 expression, at both the mRNA and protein levels, and in progesterone synthesis. Conclusion: Our results indicate that HIF-1α and NDRG1 are integral to follicular development and the early luteinization of pre-ovulatory follicles.

Harnessing the tumor microenvironment: targeted cancer therapies through modulation of epithelial-mesenchymal transition

The tumor microenvironment (TME) is integral to cancer progression, impacting metastasis and treatment response. It consists of diverse cell types, extracellular matrix components, and signaling molecules that interact to promote tumor growth and therapeutic resistance. Elucidating the intricate interactions between cancer cells and the TME is crucial in understanding cancer progression and therapeutic challenges. A critical process induced by TME signaling is the epithelial-mesenchymal transition (EMT), wherein epithelial cells acquire mesenchymal traits, which enhance their motility and invasiveness and promote metastasis and cancer progression. By targeting various components of the TME, novel investigational strategies aim to disrupt the TME's contribution to the EMT, thereby improving treatment efficacy, addressing therapeutic resistance, and offering a nuanced approach to cancer therapy. This review scrutinizes the key players in the TME and the TME's contribution to the EMT, emphasizing avenues to therapeutically disrupt the interactions between the various TME components. Moreover, the article discusses the TME's implications for resistance mechanisms and highlights the current therapeutic strategies toward TME modulation along with potential caveats.

[The role of leptin in endometrium disorders: literature review]

Leptin is not only the main regulator of energy balance, but also it affects the reproductive and immune systems. Leptin and its receptors are expressed in the endometrium and are actively involved in the embryo implantation. According to numerous studies, expression and level changes of leptin are associated with the inflammatory and autoimmune diseases, including endometriosis and chronic endometritis. Hyperplastic and inflammatory diseases of the uterus are accompanied by a violation of the receptivity of the endometrium due to the dysregulation of many factors involved in proliferation, vascularization and decidualization of cells. Activity of most of these factors is due to the leptin action, however, there are no studies of the direct effect of leptin in the pathogenesis of disorders of the endometrium in hyperplastic and inflammatory diseases.Thus, the purpose of this literature review was to describe the putative molecular mechanisms of the effect of leptin on the development of endometrial pathology.Literature search was carried out from 03/20/2023 to 05/11/2023 using scientific literature databases: NCBI PubMed, Google Scholar (foreign sources), Cyberleninka, Elibrary (domestic sources): references for the period 1995-2023 were analyzed. The following keywords were used for the search: leptin, endometrial dysfunction, endometrial receptivity, inflammation, pelvic inflammatory disease.

Hypoxia-induced upregulation of hsa-miR-584-3p suppresses endometrial glandular epithelial cell function by targeting DKK-1

OBJECTIVE

To investigate the impact of hypoxia on microRNA (miRNA) expression profiles in endometrial glandular epithelial cells (EECs) and elucidate potential mechanisms underlying proliferation, migration, and invasion.

METHODS

EECs in the logarithmic growth phase were exposed to normoxic (21% oxygen) and hypoxic (1% oxygen) conditions. MiRNA expression profiles were analyzed using RNA sequencing, and differential expression of hsa-miR-584-3p was confirmed by real-time quantitative PCR (RT-qPCR). Target prediction through TargetScan identified Dickkopf-1 (DKK-1) as a target gene of hsa-miR-584-3p. The interaction between hsa-miR-584-3p and DKK-1 was validated through a double-luciferase reporter gene assay and Western blotting. Cell proliferation, migration, and invasion were assessed using the Cell Counting Kit-8 (CCK-8) assay, wound healing assay, and Transwell invasion assay, respectively.

RESULTS

Hypoxic conditions significantly upregulated the expression of hsa-miR-584-3p in EECs (P<0.001). TargetScan analysis predicted DKK-1 as a downstream target of hsa-miR-584-3p. The double-luciferase reporter gene assay confirmed the binding of hsa-miR-584-3p to the 3' untranslated region of the DKK-1 gene, leading to reduced DKK-1 protein expression (P<0.001). Functional assays demonstrated decreased proliferation and increased migration and invasion of EECs under hypoxia.

CONCLUSION

Hypoxia-induced upregulation of hsa-miR-584-3p suppresses the function of EECs by targeting DKK-1 protein activity, thereby influencing their proliferation, migration, and invasion.

17β-Estradiol mediates TGFBR3/Smad2/3 signaling to attenuate the fibrosis of TGF-β1-induced bovine endometrial epithelial cells via GPER

Abnormal function and fibrosis of endometrium caused by cows' endometritis pose difficult implantation of embryos and uterine cavity adhesions. 17β-Estradiol (E2) serves as the most effective aromatized estrogen, and its synthetase and receptors have been detected in the endometrium. Studies have demonstrated the positive role of estrogen in combating pathological fibrosis in diverse diseases. However, it is still unknown whether E2 regulates endometrium fibrosis in bovine endometritis. Herein, we evaluated the expression patterns of transforming growth factor-β1 (TGF-β1), epithelial-mesenchymal transformation (EMT)-related proteins (α-SMA, vimentin N-cadherin and E-cadherin), cytochrome P450 19A1 (CYP19A1), and G protein-coupled estrogen receptor (GPER) in bovine healthy endometrium and Inflammatory endometrium. Our data showed that the inflamed endometrium presented low CYP19A1 and GPER expression, and significantly higher EMT process versus the normal tissue. Moreover, we established a TGF-β1-induced fibrosis model in BEND cells, and found that E2 inhibited the EMT process of BEND cells in a dose-dependent manner. The anti-fibrotic effect of E2 was blocked by the GPER inhibitor G15, but not the estrogen nuclear receptors (ERs) inhibitor ICI182780. Moreover, the GPER agonist G1 inhibited fibrosis and Smad2/3 phosphorylation but increased the expression of TGFBR3 in BEND cells. Transfection with TGFBR3 small interfering RNA blocked the effect of G1 on fibrosis of BEND cells and upregulated the expression of P-Smad2/3. Our in vivo data also showed that E2 and G1 affected uterus fibrosis in mice endometritis model caused by LPS, which was associated with the inhibition of TGFBR3/Smad2/3 signaling. In conclusion, our data implied that E2 alleviates the fibrosis of TGF-β1-induced BEND cells, which is associated with the GPER mediation of TGFBR3/Smad2/3 signaling.

Overexpression of miR-199a-5p improves brain injury in newborn rats with intrauterine infection via inhibition of astrocyte activation

White matter injury is the most common form of brain injury in preterm infants. In addition to hypoxia ischemia, intrauterine infection is most closely related to brain white matter injury. Our study aimed to explore the mechanism of the miR-199a-5p/HIF-1α axis on astrocyte activation and brain injury in newborn rats caused by intrauterine infection. The animal/cell model was established via escherichia coli infection/lipopolysaccharide induction, followed by the measurement of body weight, brain weight, and the pathological changes in brain tissues of newborn rats, and the pathological changes in placenta and uterus wall of pregnant rats. Also, the levels of GFAP, TNF-α, MDA, GSH, SOD, miR-199a-5p, and HIF-1α were detected though corresponding assays or kits. In vitro, cell viability and apoptosis and the levels of IL-6 and TNF-α were evaluated in astrocytes. Moreover, the targeting relationship between miR-199a-5p and HIF-1α was verified. miR-199a-5p was lowly expressed in the brain tissues of newborn rats with intrauterine infection. Overexpression of miR-199a-5p relieved the injury of placenta and uterus wall in pregnant rats and brain injury in newborn rats, accompanied by decreased HIF-1α, GFAP, TNF-α, and MDA levels and increased GSH and SOD levels. Results from cell models showed that miR-199a-5p overexpression inhibited astrocyte activation, shown by enhanced cell viability, weakened cell apoptosis, and decreased GFAP, IL-6, and TNF-α. Mechanistically, miR-199a-5p targeted HIF-1α to decrease its expression. Collectively, miR-199a-5p inhibited astrocyte activation and alleviated brain injury in newborn rats with intrauterine infection by reducing HIF-1α expression.

COVID-19-The Shift of Homeostasis into Oncopathology or Chronic Fibrosis in Terms of Female Reproductive System Involvement

The COVID-19 pandemic caused by the SARS-CoV-2 coronavirus remains a global public health concern due to the systemic nature of the infection and its long-term consequences, many of which remain to be elucidated. SARS-CoV-2 targets endothelial cells and blood vessels, altering the tissue microenvironment, its secretion, immune-cell subpopulations, the extracellular matrix, and the molecular composition and mechanical properties. The female reproductive system has high regenerative potential, but can accumulate damage, including due to SARS-CoV-2. COVID-19 is profibrotic and can change the tissue microenvironment toward an oncogenic niche. This makes COVID-19 and its consequences one of the potential regulators of a homeostasis shift toward oncopathology and fibrosis in the tissues of the female reproductive system. We are looking at SARS-CoV-2-induced changes at all levels in the female reproductive system.