Importance of Fibrosis in the Pathogenesis of Uterine Leiomyoma and the Promising Anti-fibrotic Effects of Dipeptidyl Peptidase-4 and Fibroblast Activation Protein Inhibitors in the Treatment of Uterine Leiomyoma

Investigating Aging-Related Endometrial Dysfunction Using Endometrial Organoids

Ageing of the endometrium is a critical factor that affects reproductive health, yet its intricate mechanisms remain poorly explored. In this study, we performed transcriptome profiling and experimental verification of endometrium and endometrial organoids from young and advanced age females, to elucidate the underlying mechanisms and to explore novel treatment strategies for endometrial ageing. First, we found that age-associated decline in endometrial functions including fibrosis and diminished receptivity, already exists in reproductive age. Subsequently, based on RNA-seq analysis, we identified several changes in molecular processes affected by age, including fibrosis, imbalanced inflammatory status including Th1 bias in secretory phase, cellular senescence and abnormal signalling transduction in key pathways, with all processes been further validated by molecular experiments. Finally, we uncovered for the first time that PI3K-AKT-FOXO1 signalling pathway is overactivated in ageing endometrium and is closely correlated with fibrosis and impaired receptivity characteristics of ageing endometrium. Blocking or activation of PI3K by LY294002 or 740Y-P could attenuate the effect of ageing or accelerate dysfunction of endometrial organoids. This discovery is expected to bring new breakthroughs for understanding the pathophysiological processes associated with endometrial ageing, as well as treatment strategies to improve reproductive outcomes in women of advanced reproductive age.

Mapping Human Uterine Disorders Through Single-Cell Transcriptomics

Disruptions in uterine tissue function contribute to disorders such as endometriosis, adenomyosis, endometrial cancer, and fibroids, which all significantly impact health and fertility. Advances in transcriptomics, particularly single-cell RNA sequencing, have revolutionized uterine biological research by revealing the cellular heterogeneity and molecular mechanisms underlying disease states. Single-cell RNA sequencing and spatial transcriptomics have mapped endometrial and myometrial cellular landscapes, which helped to identify critical cell types, signaling pathways, and phase-specific dynamics. Said transcriptomic technologies also identified stromal and immune cell dysfunctions, such as fibroblast-to-myofibroblast transitions and impaired macrophage activity, which drive fibrosis, chronic inflammation, and lesion persistence in endometriosis. For endometrial cancer, scRNA-seq uncovered tumor microenvironmental complexities, identifying cancer-associated fibroblast subtypes and immune cell profiles contributing to progression and therapeutic resistance. Similarly, studies on adenomyosis highlighted disrupted signaling pathways, including Wnt and VEGF, and novel progenitor cell populations linked to tissue invasion and neuroinflammation, while single-cell approaches characterized smooth muscle and fibroblast subpopulations in uterine fibroids, elucidating their roles in extracellular matrix remodeling and signaling pathways like ERK and mTOR. Despite challenges such as scalability and reproducibility, single-cell transcriptomic approaches may have potential applications in biomarker discovery, therapeutic target identification, and personalized medicine in gynecological disorders.

Elucidating the linagliptin and fibroblast activation protein binding mechanism through molecular dynamics and binding free energy analysis

Fibroblast activation protein (FAP) is highly expressed in solid tumors and may be a potential diagnostic and therapeutic target in solid cancers. Linagliptin inhibits FAP; however, the interaction mechanism between linagliptin and FAP remains unclear. In this study, the binding free energy for linagliptin with human FAP was estimated at -13.66 kcal/mol, and the dissociation constant was 243 nM based on surface plasmon resonance analyses. E203, E204, and Y656 formed hydrogen bonds with ammonium. Y625 formed an unstable hydrogen bond with the carbonyl group. W623 and Y541 interacted with the quinazoline and pyrimidine-2,4-dione rings, respectively, via π-π interactions. The butyne group formed hydrophobic interactions with residues V650, Y653, Y656, and Y660. ZINC000299754517 and ZINC000299754576 were identified as potential FAP inhibitors. The R1 and R4 regions of linagliptin could be optimized to increase its FAP binding affinity. These findings can guide linagliptin structural optimization to improve its FAP binding affinity.

Network-based drug repositioning of linagliptin as a potential agent for uterine fibroids targeting transforming growth factor-beta mediated fibrosis

Uterine fibroid is the most common non-cancerous tumor with no satisfactory options for long-term pharmacological treatment. Fibroblast activation protein-α (FAP) is one of the critical enzymes that enhances the fibrosis in uterine fibroids. Through STITCH database mining, we found that dipeptidyl peptidase-4 inhibitors (DPP4i) have the potential to inhibit the activity of FAP. Both DPP4 and FAP belong to the dipeptidyl peptidase family and share a similar catalytic domain. Hence, ligands which have a binding affinity with DPP4 could also bind with FAP. Among the DPP4i, linagliptin exhibited the highest binding affinity (Dock score = -8.562 kcal/mol) with FAP. Our study uncovered that the differences in the S2 extensive-subsite residues between DPP4 and FAP could serve as a basis for designing selective inhibitors specifically targeting FAP. Furthermore, in a dynamic environment, linagliptin was able to destabilize the dimerization interface of FAP, resulting in potential inhibition of its biological activity. True to the in-silico results, linagliptin reduced the fibrotic process in estrogen and progesterone-induced fibrosis in rat uterus. Furthermore, linagliptin reduced the gene expression of transforming growth factor-β (TGF-β), a critical factor in collagen secretion and fibrotic process. Masson trichrome staining confirmed that the anti-fibrotic effects of linagliptin were due to its ability to reduce collagen deposition in rat uterus. Altogether, our research proposes that linagliptin has the potential to be repurposed for the treatment of uterine fibroids.

EZH2 activates Wnt/β-catenin signaling in human uterine fibroids, which is inhibited by the natural compound methyl jasmonate

OBJECTIVE

To investigate the link between EZH2 and Wnt/β-catenin signaling and its role in uterine fibroids (UFs) pathogenesis and explore the potential effect of natural compound methyl jasmonate (MJ) against UFs.

DESIGN

EZH2 overexpression or inhibition was achieved in human uterine leiomyoma (HuLM) cells using EZH2-expressing adenovirus or chemical EZH2 inhibitor (DZNep), respectively. The HuLM and normal uterine smooth muscle cells were treated with 0.1-3 mM of MJ, and several experiments were employed.

SETTING

Laboratory study.

PATIENTS(S)

None.

INTERVENTION(S)

Methyl jasmonate.

MAIN OUTCOME MEASURE(S)

Protein expression of EZH2, β-catenin, and proliferating cell nuclear antigen (PCNA) was measured by Western blot as well as gene expression alterations of Wnt ligands (Wnt5A, Wnt5b, and Wnt9A), WISP1, CTNNB1, and its responsive gene PITX2 using quantitative real-time polymerase chain reaction. The protein and ribonucleic acid (RNA) levels of several markers were measured in MJ-treated or untreated HuLM cells, including EZH2 and β-catenin, extracellular matrix markers collagen type 1 (COL1A1) and fibronectin (FN), proliferation markers cyclin D1 (CCND1) and PCNA, tumor suppressor marker p21, and apoptotic markers (BAX, cytochrome c, and cleaved caspase 3).

RESULT(S)

EZH2 overexpression significantly increased the gene expression of several Wnt ligands (PITX2, WISP1, WNT5A, WNT5B, and WNT9A), which increased nuclear translocation of β-catenin and PCNA and eventually HuLM cell proliferation. EZH2 inhibition blocked Wnt/β-catenin signaling activation where the aforementioned genes significantly decreased as well as PCNA, cyclin D1, and PITX2 protein expression compared with those in untreated HuLM. Methyl jasmonate showed a potent antiproliferative effect on HuLM cells in a dose- and time-dependent manner. Interestingly, the dose range (0.1-0.5 mM) showed a selective growth inhibitory effect on HuLM cells, not on normal uterine smooth muscle cells. Methyl jasmonate treatment at 0.5 mM for 24 hours significantly decreased both protein and RNA levels of EZH2, β-catenin, COL1A1, FN, CCND1, PCNA, WISP1, and PITX2 but increased the protein levels of p21, BAX, cytochrome, c and cleaved caspase 3 compared with untreated HuLM. Methyl jasmonate-treated cells exhibited down-regulation in the RNA expression of 36 genes, including CTNNB1, CCND1, Wnt5A, Wnt5B, and Wnt9A, and up-regulation in the expression of 34 genes, including Wnt antagonist genes WIF1, PRICKlE1, and DKK1 compared with control, confirming the quantitative real-time polymerase chain reaction results.

CONCLUSION(S)

Our studies provide a novel link between EZH2 and the Wnt/β-catenin signaling pathway in UFs. Targeting EZH2 with MJ interferes with the activation of wnt/β-catenin signaling in our model. Methyl jasmonate may offer a promising therapeutic option as a nonhormonal and cost-effective treatment against UFs with favorable clinical utility, pending proven safe and efficient in human clinical trials.

Curcumol, a major terpenoid from Curcumae Rhizoma, attenuates human uterine leiomyoma cell development via the p38MAPK/NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Uterine fibroids (UFs) are the most common benign tumors in women of reproductive age. Curcumae Rhizoma, the main essential oil component of which is curcumol, is widely used for the treatment of phymatosis in China due to its antitumor, anti-inflammatory, antithrombin, anti-tissue fibrosis and anti-oxygen pharmacological activities, but its potential for the treatment of UFs has not been evaluated.

AIM OF THE STUDY

This study aimed to investigate the effects and mechanisms of curcumol intervention in human uterine leiomyoma cells (UMCs).

MATERIALS AND METHODS

Putative targets of curcumol intervention in UFs were identified using network pharmacology strategies. Molecular docking was performed to assess the binding affinity of curcumol to core targets. A concentration gradient of curcumol (0, 50, 100, 200, 300, 400 and 500 μM) or RU-486 (mifepristone, 0, 10, 20, 40, 50, and 100 μM) was applied to UMCs, and cell viability was detected by the CCK-8 assay. Cell apoptosis and cell cycle were examined by flow cytometry, and cell migration was assessed by a wound-healing assay. Additionally, the mRNA and protein expression levels of critical pathway components were evaluated by RT‒PCR and western blotting. Finally, the actions of curcumol on different tumor cell lines were summarized.

RESULTS

Network pharmacology predicted 62 genes with roles in the treatment of UFs with curcumol, and MAPK14 (p38MAPK) displayed a higher interaction degree. GO enrichment and KEGG analyses revealed that the core genes were abundantly enriched in the MAPK signaling pathway. The molecular binding of curcumol to core targets was relatively stable. In UMCs, 200, 300 and 400 μM curcumol treatment for 24 h decreased cell viability compared with that in the control group, and the greatest effect was detected at 48 h and maintained until 72 h. Curcumol arrested cells in the G0/G1 phase and subsequently suppressed mitosis, promoted early apoptosis and reduced the degree of wound healing in a concentration-dependent manner in UMCs. Furthermore, 200 μM curcumol decreased the mRNA and protein expression of p38MAPK, the mRNA expression of NF-κB, and the protein expression of Ki-67 and increased the mRNA and protein expression of Caspase 9. Curcumol (300 and 400 μM) decreased the mRNA and protein expression of p38MAPK, NF-κB, and Ki-67 and increased the protein expression of Caspase 9 in UMCs. Curcumol was demonstrated to treat tumor cell lines, including breast cancer, ovarian cancer, lung cancer, gastric cancer, liver cancer and nasopharyngeal carcinoma, but its effects on benign tumors have not yet been reported.

CONCLUSION

Curcumol suppresses cell proliferation and cell migration while arresting the cell cycle in the G0/G1 phase and inducing cell apoptosis in UMCs via a mechanism related to p38MAPK/NF-κB pathway regulation. Curcumol may be a potential therapeutic and preventive agent in the treatment of benign tumors such as UFs.

Role and mechanism of fibroblast-activated protein-α expression on the surface of fibroblast-like synoviocytes in rheumatoid arthritis

Fibroblast-activated protein-α (FAP) is a type II integrated serine protease expressed by activated fibroblasts during fibrosis or inflammation. Fibroblast-like synoviocytes (FLSs) in rheumatoid arthritis (RA) synovial sites abundantly and stably overexpress FAP and play important roles in regulating the cellular immune, inflammatory, invasion, migration, proliferation, and angiogenesis responses in the synovial region. Overexpression of FAP is regulated by the initial inflammatory microenvironment of the disease and epigenetic signaling, which promotes RA development by regulating FLSs or affecting the signaling cross-linking FLSs with other cells at the local synovium and inflammatory stimulation. At present, several treatment options targeting FAP are in the process of development. This review discusses the basic features of FAP expressed on the surface of FLSs and its role in RA pathophysiology and advances in targeted therapies.