Shuqin Chen

Response to Letter in regards to Metabolomics Analysis Reveals Gut Microbiota-Associated Sakuranin Modulates Endometrial Stem Cell Differentiation and Inflammation to Alleviate Pain in Endometriosis [Letter]

CDK4/6 inhibitors (CDK4/6i) have shown striking clinical potential in hormone receptor-positive breast cancers (BC) and endometrial cancers (EC), whereas resistance hinders their clinical utilization. The role of epigenetic alterations in CDK4/6i resistance remains poorly elucidated. Herein, through a comprehensive analysis of transcriptomic and chromatin profiles in 16 EC tissues and cell-based resistance models, we delineate the super-enhancer (SE) landscape and identify aldehyde dehydrogenase 1 family member A1 (ALDH1A1) as a SE-driven gene closely associated with CDK4/6i resistance. ALDH1A1 inhibition increases susceptibility to CDK4/6i in multiple EC and BC models. Mechanistically, we demonstrate that ALDH1A1 promotes vitamin A (vitA) metabolism and induces the accumulation of its downstream metabolite, retinoic acid (RA), in resistant cells. In return, the elevated RA potentiates the interaction between retinoic acid receptor alpha (RARα) and estrogen receptor alpha (ERα) in the nucleus and facilitates RARα/ERα-occupied SE-driven transcriptional activation of ALDH1A1, establishing a positive feedback loop that promotes CDK4/6i resistance. These findings highlight the crucial role of vitA metabolism in the epigenetic transcriptional program associated with CDK4/6i resistance, suggesting that avoiding high vitA intake or inhibiting the ALDH1A1-RA axis may be effective strategies to overcome this challenge.

Endometriosis (EMS) is characterized by pain symptoms that seriously affect patients’ quality of life. Gut microbiome-related metabolites (GMRM) play an important role in the process of EMS. However, the role of GMRM in endometrial stem cells and EMS-related pain remains unclear. An untargeted metabolomics approach was employed to analyze the fecal samples of 10 healthy individuals (heal), 11 EMS patients without dysmenorrhea (pless), and 14 EMS patients with dysmenorrhea (pain). The impact of potential key metabolite sakuranin on EMS-related pain was further investigated in vitro and in vivo. We identified 33 metabolites that were commonly changed in the painful group compared to the health and pless groups, and these metabolites were associated with differential microorganisms. Among them, sakuranin was downregulated in the painful group and exhibited a notably inverse correlation with the degree of pain. ROC curve revealed that sakuranin had a relatively high predictive value for EMS-related pain (AUC=0.8027). Functionally, sakuranin inhibited differentiation, migration, and inflammatory cytokine production, and decreased the expression of VEGF and ALCAM in SUSD2-positive primary endometrial cells. In EMS mice, sakuranin suppressed ectopic lesion growth, reduced inflammation, modulated angiogenesis and proliferation markers (VEGF, ALCAM, Ki-67), and regulated sympathetic and sensory nerve markers, resulting in alleviated pain behaviors. We delineated the metabolic landscape related to EMS-related pain and uncovered that sakuranin has the potential to inhibit the growth of EMS and alleviate EMS-related pain. This finding offers therapeutic strategies of sakuranin in alleviating the pain symptoms associated with EMS.

Background: Endometriosis (EMS), which affects >10% of women, is characterized by painful symptoms, such as dysmenorrhea. Meanwhile, the gut microbiota is linked to EMS; however, the relationship between the gut microbiota and EMS-related pain remains unclear. Methods: This study conducted 16S rRNA sequencing on fecal samples from 20 patients with EMS and dysmenorrhea, 13 patients with EMS but not dysmenorrhea, and 12 healthy controls. Results: Carbohydrate antigen 125 (CA125) levels were significantly higher in patients with EMS and dysmenorrhea. No significant differences in α- and β-diversity values were observed among the three groups (p > 0.05). However, Proteobacteria and Subdoligranulum showed increased abundance trends in patients with EMS and dysmenorrhea. Acinetobacter and Colidextribacter were less abundant in patients with EMS and dysmenorrhea than in those without dysmenorrhea (p < 0.05). Faecalicoccus pleomorphus and its genus also showed consistent depletion. At the genus level, a correlation analysis of the differential microbes revealed that UCG_005 and UCG_002 were central nodes in the correlation network (p < 0.05). Functional prediction indicated significant enrichment in cofactor and vitamin metabolism pathways in the EMS group with dysmenorrhea (p < 0.05). Several differential microbes, such as Faecalicoccus, Colidextribacter, and Acinetobacter, were negatively correlated with pain severity. Receiver operating characteristic curve analysis identified 10 microbial species with moderate diagnostic potential (area under the curve >0.7) for discriminating patients with EMS and dysmenorrhea, notably Ligilactobacillus. Conclusions: These results highlight distinct microbial alterations and functional pathways associated with EMS-related pain, suggesting potential diagnostic biomarkers for this condition.

This study aimed to identify risk and protective factors for postoperative recurrence of deep infiltrating endometriosis (DIE). We analyzed 320 patients undergoing laparoscopic excision with ≥ 6 years follow-up at the First Affiliated Hospital of Sun Yat-sen University. Cumulative recurrence rates increased from 7.1% at 6 years to 14.1% by 12 years post-surgery. Multivariate analysis identified left ovarian endometrioma (EMA) as an independent risk factor (HR: 6.413, 95% CI: 2.961-13.889, P < 0.001), while older age (HR: 0.836, 95% CI: 0.788-0.887, P < 0.001), GnRH-a use ≥ 6 months (HR: 0.324, 95% CI: 0.178-0.589, p < 0.001), and postoperative pregnancy (HR: 0.847, 95% CI: 0.179-0.748, p = 0.006) were protective. Gravidity, parity, and unilateral EMA showed univariate associations (P < 0.05), but BMI, dysmenorrhea severity, infertility, and hysterectomy status were nonsignificant. These findings highlight left-side EMA presence was an independent risk factor for the recurrence of deep infiltrating endometriosis after surgery during long-term follow-up. Age, use of GnRH-a for 6 months and postoperative pregnancy were protective factors against recurrence.

Multifunctional small‐molecule theranostic agents hold significant clinical potential for non‐invasive endometriosis (EMS) management. Current EMS treatment faces challenges due to imprecise lesion localization and therapy‐associated side effects. Herein, an integrated theranostic probe, cRGDyK‐ICG‐Lys‐DTPA@Gd (cRGD‐ILD), designed for concurrent precise lesion localization and targeted phototherapy in EMS, is developed. This molecular probe integrates three key functional components: the DTPA@Gd complex provides contrast for magnetic resonance imaging, the ICG fragment enables fluorescence imaging and photoacoustic imaging while serving as the phototherapeutic agent, and the cRGD peptide targets integrin α _v β ₃ receptors to facilitate precise accumulation in ectopic endometrial tissue. Specifically, cRGD‐ILD leverages its small size and receptor‐mediated transcytosis to penetrate neovascularized tissue and target ectopic endometrial cells. Under 808 nm laser irradiation, the ICG moiety generates reactive oxygen species and heat, exerting combined photodynamic and photothermal therapeutic effects that effectively suppress lesion progression in both autografted EMS rats and xenografted nude mice. Notably, composed of clinically available and FDA‐approved constituents, the probe demonstrates favorable biocompatibility and biosafety for in vivo applications. Overall, this well‐designed molecular probe enables precise multimodal imaging guidance and localized phototherapy for EMS.

Endometriosis, a chronic immune-mediated inflammatory disease, remains elusive in its pathogenesis. Given vitamin D (VD)’s pivotal role in modulating innate and adaptive immune responses, we sought to elucidate how VD modulates inflammatory responses in endometriosis. We isolated primary human ectopic endometrial stromal cells (EESCs) from ectopic endometrium of ovarian endometrioma, alongside Ishikawa cells, and subjected them to treatment with lipopolysaccharide (LPS), a potent inducer of inflammation, alongside varying concentrations of 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃), the biologically active form of VD, and its analog TEI-9647 (25-dehydro-1α-hydroxyvitamin D₃-26,23-lactone). Our results revealed that 1,25(OH)₂D₃ significantly reversed LPS-induced cell proliferation, migration, and inflammatory factor production in EESCs and Ishikawa cells, and induced apoptosis. Additionally, 1,25(OH)₂D₃ inhibited the expression and nuclear translocation of phosphorylated p65 in LPS-activated EESCs and Ishikawa cells. Furthermore, 1,25(OH)₂D₃ counteracted LPS-induced suppression of VD receptor (VDR)/IκBα and enhancement of Toll-like receptor 4 (TLR4)/pyrin domain (PYD)-containing protein 3 (NLRP3) activation, while the addition of TEI-9647 reversed VD’s regulatory effects on the NF-κB pathway. In vivo experimental results showed that 1,25(OH)₂D₃ significantly inhibited lesion growth, suppressed NF-κB pathway activation, and corresponding inflammatory phenotypes in a rat model of endometriosis. Collectively, these results underscore the potential of 1,25(OH)₂D₃ as a therapeutic target for endometriosis via VDR-dependent endometrial homeostasis regulation, suppressing LPS-mediated inflammatory responses and NF-κB signaling pathway through VDR activation and IκBα stabilization.

An increasing number of research have suggested that ferroptosis plays an important role in endometriosis (EMS). This study was to identify a ferroptosis-related diagnosis gene in EMS by using bioinformatics. R Bioconductor package limma was used to analyzed the differentially expressed genes (DEGs) between the EMS groups and control groups. CIBERSORT was used to analyze the differences between the EMS group and control group of 22 immune cells. Quantitative real-time PCR (RT-qPCR) and Western blot (WB) were used to validate the expression level of FZD7 in tissue samples. The study found that FZD7 was upregulated and showed good diagnostic value in five EMS transcriptome databases. RT-qPCR and WB experiments also verified that FZD7 was upregulated in EMS. Moreover, we found that macrophages, especially M2 macrophages, were significantly infiltrated in EMS. FZD7 was positively correlated with M2 macrophage infiltration, and was up-regulated in the endometrial stromal cells co-cultured with macrophages. The study identified an ferroptosis repressor gene, FZD7, validated in five EMS transcriptome datasets, which is significantly up-regulated in ectopic lesions of EMS and is a potential target for the treatment of EMS.