Metallopeptidades 2 and 9 genes epigenetically modulate equine endometrial fibrosis

Ovarian steroids modulate mRNA expression of ECM associated genes and collagen deposition induced by TGF β1 in equine endometrium in vitro

Equine endometrosis is a major cause of infertility in mares and is characterized by degenerative, functional and fibrotic changes in the endometrium with increased collagen (COL) deposition. Transforming growth factor (TGF)-β1 is one of the major pro-fibrotic factors involved in the excessive deposition of extracellular matrix (ECM) components in the equine endometrium. It has been demonstrated that ovarian steroids, specifically 17β-estradiol (E2) and progesterone (P4), not only regulate the cyclicity of the estrous cycle, but also have been implicated as anti- or pro-fibrotic factors. This study aimed to evaluate (i) the effect of E2 and P4 on the expression of ECM-associated genes including COL1A1, COL3A1, matrix metalloproteases (MMPs): MMP-1, MMP-2, MMP-3, MMP-9, and MMP-13, and tissue inhibitors of MMPs (TIMPs): TIMP-1 and TIMP-2 in equine endometrial fibroblasts, and (ii) the effect of ovarian steroids on TGF-β1-induced COL1 expression in equine endometrial explants from the follicular and mid-luteal phases of the estrous cycle. The mRNA expression of ECM-associated genes in endometrial fibroblasts and TGF-β1-induced COL1 expression in endometrial explants was modulated by ovarian steroids, with variations depending on the type of steroid and the duration of treatment. Moreover, P4 decreased TGF-β1-induced COL1 protein abundance in the mid-luteal phase of the estrous cycle after 48 h (p < 0.05). The results of our study indicate that during the estrous cycle, the ovarian steroids E2 or P4 may act directly on endometrial fibroblasts, thereby affecting the expression of genes involved in tissue remodeling, namely MMPs and TIMPs. Furthermore, P4 appears to affect not only the ECM-associated genes in endometrial fibroblasts, but also to attenuate the pro-fibrotic action of TGF-β1 in the mid-luteal stage of the estrous cycle.

Extracellular vesicles secreted by equine adipose mesenchymal stem cells preconditioned with transforming growth factor β-1 are enriched in anti-fibrotic miRNAs and inhibit the expression of fibrotic genes in an in vitro system of endometrial stromal cells fibrosis

Mare endometrosis is a major reproductive problem associated with low fertility and is characterized by persistent inflammation, TGFβ-1 signaling, and consequently, extracellular matrix deposition, which compromises endometrial glands. Mesenchymal stem cell-based products (MSCs), such as extracellular vesicles (EVs), have gained attention due to the regulatory effects exerted by their miRNA cargo. Here, we evaluated the impact of preconditioning equine adipose mesenchymal stem cells with TGFβ-1 for short or long periods on the anti-fibrotic properties of secreted extracellular vesicles. MSCs were isolated from six healthy horses and exposed to TGFβ-1 for 4, 24, and 0 h. The expression of anti-fibrotic and pro-fibrotic miRNAs and mRNAs in treated cells and miRNAs in the cargo of secreted extracellular vesicles was measured. The resulting EVs were added for 48 h to endometrial stromal cells previously induced to a fibrotic status. The expression of anti-fibrotic and pro-fibrotic genes and miRNAs was evaluated in said cells using qPCR and next-generation sequencing. Preconditioning MSCs with TGFβ-1 for 4 h enriched the anti-fibrotic miRNAs (mir29c, mir145, and mir200) in cells and EVs. Conversely, preconditioning the cells for 24 h leads to a pro-fibrotic phenotype overexpressing mir192 and mir433. This finding might have implications for developing an EV-based protocol to treat endometrial fibrosis in mares.

The path to fertility: Current approaches to mare endometritis and endometrosis

The path to fertility in the mare requires an understanding of the hormonal influences, the immune response, genetics, and epigenetic mechanisms involved not only in physiological reproductive processes, but also such pathologies as endometritis and endometrosis. Endometritis may lead to endometrosis establishment. In the presence of endometritis, neutrophils arrive at the mare endometrium, and form neutrophil extracellular traps. While NETosis plays pivotal roles, prolonged inflammation can lead to chronic endometritis, endometrosis, and fertility issues. Matrix metalloproteinases and epigenetic changes influence the course of endometrosis. Inhibitors of specific enzymes involved in NETosis and epigenetic inhibitors have shown potential in reducing pro-fibrotic effects. Collagen type III (COL3) has emerged as a putative biomarker, correlating with endometrosis and useful in fertility assessment. Thus, COL3 may offer a non-invasive diagnostic tool, as a complement to histopathological methods. Epigenetic modifications and miRNA expressions offer new avenues for therapeutic strategies, emphasizing the importance of understanding the cellular mechanisms at play in mare endometrial fibrosis.

The potential role of miRNAs and regulation of their expression in the development of mare endometrial fibrosis

Mare endometrial fibrosis (endometrosis), is one of the main causes of equine infertility. Despite the high prevalence, both ethology, pathogenesis and the nature of its progression remain poorly understood. Recent studies have shown that microRNAs (miRNAs) are important regulators in multiple cellular processes and functions under physiological and pathological circumstances. In this article, we reported changes in miRNA expression at different stages of endometrosis and the effect of transforming growth factor (TGF)-β1 on the expression of the most dysregulated miRNAs. We identified 1, 26, and 5 differentially expressed miRNAs (DEmiRs), in categories IIA (mild fibrosis), IIB (moderate fibrosis), and III (severe fibrosis) groups compared to category I (no fibrosis) endometria group, respectively (Padjusted < 0.05, log2FC ≥ 1.0/log2FC ≤  - 1.0). This study indicated the potential involvement of miRNAs in the regulation of the process associated to the development and progression of endometrosis. The functional enrichment analysis revealed, that DEmiRs target genes involved in the mitogen-activated protein kinases, Hippo, and phosphoinositide-3-kinase (PI3K)-Akt signalling pathways, focal adhesion, and extracellular matrix-receptor interaction. Moreover, we demonstrated that the most potent profibrotic cytokine-TGF-β1-downregulated novel-eca-miR-42 (P < 0.05) expression in fibroblasts derived from endometria at early-stage endometrosis (category IIA).

5-Aza-2′-Deoxycytidine (5-Aza-dC, Decitabine) Inhibits Collagen Type I and III Expression in TGF-β1-Treated Equine Endometrial Fibroblasts

Endometrosis negatively affects endometrial function and fertility in mares, due to excessive deposition of type I (COL1) and type III (COL3) collagens. The pro-fibrotic transforming growth factor (TGF-β1) induces myofibroblast differentiation, characterized by α-smooth muscle actin (α-SMA) expression, and collagen synthesis. In humans, fibrosis has been linked to epigenetic mechanisms. To the best of our knowledge, this has not been described in mare endometrium. Therefore, this study aimed to investigate the in vitro epigenetic regulation in TGF-β1-treated mare endometrial fibroblasts and the use of 5-aza-2′-deoxycytidine (5-aza-dC), an epigenetic modifier, as a putative treatment option for endometrial fibrosis. Methods and Results: The in vitro effects of TGF-β1 and of 5-aza-dC on DNA methyltransferases (DNMT1, DNMT3A, and DNMT3B), COL1A1, COL3A1, and α-SMA transcripts were analyzed in endometrial fibroblasts, and COL1 and COL3 secretion in a co-culture medium. TGF-β1 upregulated DNMT3A transcripts and collagen secretion. In TGF-β1-treated endometrial fibroblasts, DNA methylation inhibitor 5-aza-dC decreased collagen transcripts and secretion, but not α-SMA transcripts. Conclusion: These findings suggest a possible role of epigenetic mechanisms during equine endometrial fibrogenesis. The in vitro effect of 5-aza-dC on collagen reduction in TGF-β1-treated fibroblasts highlights this epigenetic involvement. This may pave the way to different therapeutic approaches for endometrosis.

Identification and verification of IGFBP3 and YTHDC1 as biomarkers associated with immune infiltration and mitophagy in hypertrophic cardiomyopathy

Background: Hypertrophic cardiomyopathy (HCM) is the main cause of sudden cardiac death among young adults, yet its pathogenesis remains vague. N6-methyladenosine (m6A) methylation modification was involved in various cardiovascular diseases such as coronary heart disease and heart failure, although its influence on HCM remains unclear. This study aimed to explore the potential role of m6A in the diagnosis and pathogenesis of HCM.

Methods: GSE36961 including 106 HCM and 39 controls was used in the study. The HCM-related m6A regulators were selected using support vector machine recursive feature elimination and random forest algorithm. A significant gene signature was then established using least absolute shrinkage and selection operator and then verified by GSE130036. Subgroup classification of HCM was performed based on the expression of m6A biomarkers. Gene set variation analysis was employed to explore the functional difference between distinct subgroups. Weighted gene co-expression network analysis was used to determine the m6A-related hub module. Single-sample gene set enrichment analysis was conducted to assess the immune and mitophagy features between subgroups. Besides, transfection of recombinant plasmids with targeted genes into H9c2 cells was performed to further verify the function of the significant biomarkers.

Results: Significant difference existed in m6A landscape between HCM and control patients, among which IGFBP3 and YTHDC1 were identified as the independent biomarkers of HCM. Highly infiltrated immune cells (MDSC, macrophages, etc.), more enriched immune-related pathways (TNFα signaling via NFκB and IL6-JAK-STAT3 signaling) and cardiac remodeling-associated pathways (epithelial mesenchymal transition, angiogenesis, etc.) were identified in the subgroup with higher IGFBP3. Consistently, overexpression of IGFBP3 in H9c2 cells led to upregulation of extracellular-matrix-related genes (COL1A2, COL3A1 and MMP9) and inflammation-related genes (TNFα and IL6). Besides, higher YTHDC1 expression seemed to be consistent with less-activated mitophagy (PINK1-PRKN mediated mitophagy) and energy metabolism. Further experiments demonstrated that overexpression of YTHDC1 resulted in up-regulation of PINK and PRKN in cardiomyocytes, which are essential genes mediating mitophagy.

Conclusion: Two m6A readers (IGFBP3 and YTHDC1) well distinguished HCM and may facilitate clinical diagnosis. IGFBP3 may play a role in the immune-microenvironments and remodeling of cardiac tissues, while YTHDC1 may influence mitophagy and energy metabolism in HCM.