Background:Despite optimized blood pressure control and glycemic management reducing the incidence of diabetic nephropathy (DN), significant residual risk remains, suggesting the contribution of pathogenic factors independent of glucose metabolism and hemodynamic disturbances. Methods:Renal tissues from db/db mice underwent integrative multi-omics analysis, encompassing transcriptomics, metabolomics, and lipidomics. Orthogonal projection to latent structures-discriminant analysis (OPLS-DA) was applied to identify significant metabolic perturbations, while bidirectional O2PLS integration elucidated metabolic-transcriptomic correlations. Lipid reaction networks were reconstructed using LINEX2, followed by local topology exploration to identify highly interconnected modules. Mechanistic pathways governing gene-metabolite-lipid interactions were inferred via random walk with restart algorithms and validated by gene set enrichment analysis (GSEA). Results:Transcriptomics revealed extensive dysregulation of metabolic and lipid regulatory pathways in db/db. Metabolomic integration pinpointed perturbations within glycine-serine-threonine (Gly-Ser-Thr) metabolism as the most significantly perturbed pathway (P < 0.001), with cross-omics validation identifying GLUL as a pivotal regulatory gene through. Lipidomics uncovered pronounced abnormalities in cardiolipin species composition and plasmalogen profiles. Transcriptome-lipidome integration demonstrated impaired phosphatidylcholine (PC) biosynthesis, mechanistically linked to dysregulation of choline phosphotransferase 1 (chpt1), which correlated significantly with compromised tissue regeneration capacity. Conclusion:This multi-omics study systematically delineates the molecular landscape of DN pathogenesis, uncovering previously underappreciated metabolic perturbations and distinct lipid dysregulation patterns. Our findings elucidate mechanistic insights into extra-glycemic disease drivers and propose potential therapeutic targets for DN management.

Introduction:Epithelial ovarian cancer (EOC) has a dismal prognosis, and recent therapeutic advancements have been limited. The aim of our study was to clarify the role and mechanism of cetrorelix in EOC apoptosis and to evaluate the clinical relevance of GnRHR, AKT, and FOXO1 in EOC patients. Methods:Apoptosis was assessed using flow cytometry, Hoechst staining, and Western blotting. FOXO1, p-AKT and GnRHR knockdown via siRNA was performed to reverse cetrorelix-induced apoptosis. Mechanistic insights were explored using apoptosis gene PCR arrays, qRT-PCR, and Western blotting. In vivo efficacy was tested in a xenograft mouse model. Immunohistochemistry (IHC) was used to assess GnRHR, AKT,p-AKT and FOXO1 expression in EOC tissues, and survival analysis was performed using Kaplan-Meier and Cox regression analyses. Results:Cetrorelix facilitated EOC apoptosis both in vitro and in a xenograft model. The results of apoptosis PCR arrays linked cetrorelix treatment to the upregulation of the TNF/TNF receptor superfamily (a FOXO1-dependent mechanism). Mechanistically, cetrorelix upregulated FOXO1 expression, and FOXO1 knockdown attenuated cetrorelix-induced apoptosis. Furthermore, cetrorelix-mediated suppression of p-AKT expression and subsequent FOXO1 activation occurred via the PI3K/AKT signaling axis. This mechanism was substantiated by the findings that the PI3K inhibitor LY294002 mimicked cetrorelix's effects without producing an additive apoptotic response, and that GnRHR knockdown abrogated cetrorelix-induced apoptosis, confirming receptor specificity. Experiments in xenograft models recapitulated the PI3K/AKT/FOXO1 cascade modulation observed in vitro. However, the in vivo activation status of FOXO1 was not quantitatively assessed or localized within the xenograft tissues. Clinically, FOXO1/GnRHR positivity and AKT negativity were correlated with early-stage disease (FIGO I-II, p < 0.05), no metastasis (p < 0.05), and improved survival (log-rank p < 0.05). Multivariate analysis revealed GnRHR positivity, AKT negativity, low-grade pathological type and early FIGO stage as independent risk factors for improved overall survival. Conclusion:These findings suggest that cetrorelix may induce EOC apoptosis via the PI3K/AKT-FOXO1 pathway, which provides mechanistic support for the therapeutic potential of GnRH antagonists in EOC management. Moreover, the identified critical regulatory pathways are prospective therapeutic targets for EOC management.

Focal cortical dysplasia type II (FCDII) is a major cause of drug-resistant epilepsy, but genetic factors explain only some cases, suggesting other mechanisms. In this study, we conduct a molecular analysis of brain lesions and adjacent areas in FCDIIb patients. By analyzing over 217,506 single-nucleus transcriptional profiles from 15 individuals, we find significant changes in smooth muscle cells (SMCs) and astrocytes. We identify abnormal vascular malformations and a unique type of SMC that we call "Firework cells", which migrate from blood vessels into the brain parenchyma and associate with VIM+ cells. These abnormalities create localized ischemic-hypoxic (I/H) microenvironments, as confirmed by clinical data, further impairing astrocyte function, activating the HIF-1α/mTOR/S6 pathway, and causing neuronal loss. Using zebrafish models, we demonstrate that vascular abnormalities resulting in I/H environments promote seizures. Our results highlight vascular malformations as a factor in FCDIIb pathogenesis, suggesting potential therapeutic avenues.

Subsequently to the publication of the above paper, an interested reader drew to the authors' attention the fact that six consecutive β‑actin bands looked similar, comparing across panels in Fig. 6A and B on p. 1040, even though different time points were represented in these experiments.  After having re‑examined their original data files, the authors realized that the β‑actin bands shown in Fig. 6A were inadvertently assembled incorrectly. The revised version of Fig. 6, now featuring the correct β‑actin blots for Fig. 6A, is shown on the next page. Note that the corrections made to this figure do not affect the overall conclusions reported in the paper. The authors are grateful to the Editor of Oncology Reports for allowing them the opportunity to publish this further Corrigendum, and apologize to the readership for any inconvenience caused. [Oncology Reports 39: 1034‑1042, 2018; DOI: 10.3892/or.2017.6159].

Background This study aimed to summarize and analyze clinical characteristics and reproductive outcomes in postoperative deep infiltrating endometriosis (DIE). Methods This retrospective cohort study included 55 reproductive-aged patients who were diagnosed with DIE, wished to conceive and underwent resection surgery at the Obstetrics and Gynecology Hospital, Fudan University, from January 2009–June 2017. Those with any plausible infertility factor or abnormalities in the partner’s semen analysis were excluded. Patient characteristics, preoperative symptoms, infertility history, intraoperative findings and reproductive outcomes were followed up and recorded. Risk factors for reproductive outcomes were identified for women who became pregnant versus those who did not by univariate logistic regression. Additionally, pre- and postoperative endometriosis health profile questionnaire-30 (EHP-30), Knowles–Eccersley–Scott Symptom questionnaire (KESS), Cox Menstrual Symptom Scale (CMSS) and Female Sexual Function Index (FSFI) scores were used to evaluate the effect of DIE surgery on quality of life. Results The average age was 30.22 ± 3.62 years, with no difference between the pregnancy and nonpregnancy groups. The average follow-up time was 26.57 ± 14.51 months. There were 34 pregnancies (61.82%): 24 (70.59%) conceived spontaneously and 10 (29.41%) by in vitro fertilization (IVF). Twenty-eight patients (82.35%) had term deliveries. The interval between operation and pregnancy was 10.33 ± 5.6 (1–26) months. Univariate analysis showed that a lower endometriosis fertility index (EFI) score (EFI < 8) was a risk factor for infertility (OR: 3.17 (1.15–10.14), p = .044). For patients with incomplete surgery, postoperative gonadotropin-releasing hormone agonist (GnRHa) administration improved the pregnancy rate (p < 0.05). Regarding quality of life, there was significant improvement (p < 0.05) in the postoperative EHP-30, KESS and CMSS scores compared with preoperative scores in both groups. Although there was no obvious difference in FSFI scores, significant improvement in dyspareunia was observed (p < 0.05). Conclusions Overall, the postoperative pregnancy rate of DIE patients was 61.82%. Surgical management of DIE for patients with complaints of pain and with pregnancy intentions was feasible and effective. Long-term expectant treatment should not be advised for patients with lower EFI scores (EFI < 8), and postoperative IVF–ET may be a good choice. More cases should be enrolled for further study, and randomized studies are required.

Purpose: Clear cell adenocarcinoma of the cervix (CCAC) is a rare pathological type of cervical cancer. This study aimed to report our clinical experience with CCAC treatment and analyze the factors associated with patient survival. Patients and Methods: This single-center study included patients diagnosed with CCAC and treated between 01/2003 and 12/2017 at the Obstetrics and Gynecology Hospital of Fudan University. The patients diagnosed with CCAC that underwent radical resection were included. The Kaplan-Meier method and multivariable Cox regression analysis were performed to determine factors associated with patient survival. Results: Fifty-four patients were included. None were exposed to diethylstilbestrol. The median follow-up was 96 (13.0, 120.0) months. The median recurrence-free survival (RFS) and overall survival (OS) were 68 and 78 months, respectively. Positive pelvic lymph nodes (HR=2.87, 95% confidence interval [CI] 1.14-7.22, P=0.03), tumor size > 4 cm (HR=3.31, 95% CI 1.35-8.12, P=0.01), International Federation of Gynecology and Obstetrics (FIGO) IB2-IIA2 stage (HR=2.49, 95% CI 1.56-3.99, P=0.02), and post-operative therapy (HR=1.73, 95% CI 1.07-2.81, P=0.03) were associated with OS. Multivariable analysis showed that FIGO stage IB2-IIA2 (HR=2.36, 95% CI 1.52-3.68, P< 0.01) and lymph node status (HR=3.05, 95% CI 1.12- 8.28, P=0.03) were independently associated with OS. Conclusion: Advanced FIGO stage and positive lymph node status are independently associated with shorter survival in patients with CCAC who were not exposed to diethylstilbestrol. After surgery, chemotherapy and concurrent chemoradiotherapy were not independently associated with the prognosis of patients with CCAC.

OBJECTIVE:Cervical cancer (CC) ranks fourth most diagnosed cancer and cancer mortality in women. Long non-coding RNAs (lncRNAs) take important roles in CC development. This study aimed to identify more and novel competing endogenous RNA (ceRNA) mechanisms of lncRNAs in CC. MATERIALS AND METHODS:The miRNA expression dataset GSE20592 and lncRNA/mRNA expression dataset GSE63514 were downloaded from Gene Expression Omnibus. The differentially expressed genes (DEGs), differentially expressed lncRNAs (DElncRNAs), and differentially expressed miRNAs (DEmiRNAs) between CC tumor and normal samples were identified with the criteria of adj.P.Value < 0.05 (Benjamini & Hochberg) and |log2(fold change)|>2. Functional enrichment analysis was performed for DEGs. The interaction pairs among lncRNAs, miRNAs and mRNAs were predicted and the ceRNA network was then constructed. Survival analysis was performed based on the TCGA dataset. RESULTS:Totally, 42 DEmiRNAs, 25 DElncRNAs, and 518 DEGs were identified in CC tumor samples versus normal tissues. The DEGs were associated with 'GO:0006260: DNA replication', 'GO:0051301: cell division', and 'hsa01100:Metabolic pathways'. The ceRNA network consisted of 878 lncRNA-miRNA-mRNA pairs. Of the miRNAs, lncRNAs, and genes with the top 10 interaction degrees in the ceRNA network, the upregulated cyclin dependent kinase inhibitor 2A gene (CDKN2A) was targeted by the downregulated DEmiRNAs including hsa-miR-125b-5p and hsa-miR-125a-5p, which were targeted by the upregulated DElncRNA BBOX1-AS1. The high expression level of CDKN2A contributed to the poor overall survival of patients with CC. CONCLUSIONS:The BBOX1-AS1-hsa-miR-125b-5p/hsa-miR-125a-5p-CDKN2A ceRNA network is of great value in CC development.

The ovarian structure is complex and diverse, including egg cells, granulosa cells and other cell types. Its organ function depends heavily on normal development. Numerous studies have focused on certain gene function changes during ovarian development, but systematic analyses of its molecular changes are extremely rare. Here, we present a comprehensive transcriptional profile of the mouse ovary from 11 time points across multiple developmental stages, which enables us to explore the dynamics of ovarian development. By performing coexpression analysis, we identified gene modules with similar expression trends and determined 159 functional gene interaction networks based on machine learning. Most of these gene interaction networks are related to biological processes involved in the development of the ovary, which provides functional predictions for some genes with unknown functions and a reference for subsequent functional research. In general, our study provides a resource for understanding ovarian development.

ObjectiveThe aim of our study was to evaluate and compare the differences in the clinicopathological variables and overall survival (OS) of synchronous primary cancers of the endometrium and ovary (SCEO) and endometrial cancer with ovarian metastasis (ECOM). In addition, we aimed to determine the characteristics of and effective treatments for patients with SCEO to avoid misdiagnosis and overtreatment.Materials and methodsA review of medical records from January 2009 to January 2017 revealed 111 patients with coexisting ovarian and endometrial carcinoma diagnosed at the Obstetrics and Gynecology Hospital of Fudan University. Clinicopathological variables were analysed using the Chi square test and Student's t test. The survival rate was estimated using the Kaplan-Meier method, and statistical significance was analysed using the logarithmic rank test (univariate analysis).ResultsThere were 51 cases of SCEO and 60 cases of ECOM. The mean age at diagnosis was 53.96years and 55.41years, respectively. There were no differences in age, menopausal status, BMI, CA125 level or complaints between the two groups. The 5-year survival rates were 58.8 and 36.7%, respectively (P<0.001). Significant differences were found in the endometrial tumour classification, ovarian cancer stage, and lymph node and omentum metastasis between SCEO and ECOM.ConclusionsThe differences found between SCEO and ECOM are of great clinical significance. Our results reveal useful prognostic and clinicopathological features. More aggressive therapies should be administered to both SCEO and ECOM patients, especially elderly patients and those with menopause, endometrial tumours, advanced omentum metastasis, and lymph node dissection.

The aim of this study was to evaluate the stiffness variation of the levator ani in patients with stage I/II pelvic organ prolapse (POP) before and after Kegel exercises by transperineal elastography.

Recent studies have shown that renin angiotensin system (RAS) inhibitors improve the survival of patients with several types of cancer such as pancreatic cancer. However, the anti-tumor mechanisms of RAS inhibitors remain unclear. The objective of this study was to investigate the potential mechanisms of the improvement of survival by RAS inhibitors. MTT and scratch wound healing assays were conducted using pancreatic cancer cells treated with RAS inhibitors or paclitaxel as a single agent or in combination to investigate the influence of RAS inhibitors on pancreatic cancer cell proliferation and migration. Rat aortic ring assays were conducted to investigate the influence of RAS inhibitors on angiogenesis. Cell proliferation assays were conducted using human umbilical vein endothelial cells (HUVECs) treated with RAS inhibitors or angiotensin II as a single agent or in combination to investigate the influence of RAS inhibitors on angiotensin II-mediated cellular effects. Our results showed that a high concentration (100 mu M) of RAS inhibitors suppressed the proliferation of pancreatic cancer cell lines (Panc-1, Bxpc-3, and CFPAC-1) when used alone or in combination with paclitaxel, but did not influence cell migration. RAS inhibitors significantly inhibited angiogenesis in rat thoracic aorta rings. In addition, a low concentration of angiotensin II promoted the growth of HUVEC cells, whereas the high concentration suppressed cell growth. ARBs inhibited the cellular effects caused by angiotensin II in HUVEC cells, whereas ACEIs did not inhibit such effects. In conclusion, RAS inhibitors may improve survival of cancer patients by inhibition of angiogenesis and influencing angiotensin II.

STUDY QUESTION:Could human umbilical cord mesenchymal stem cell-derived exosomes (hucMSC-Ex) accelerate vaginal epithelium cell (VK2) growth?SUMMARY ANSWER:HucMSC-Ex play a significant role in promoting proliferation of VK2 cells by accelerating the cell cycle and inhibiting apoptosis through exosomal microRNAs in vitro.WHAT IS KNOWN ALREADY:Numerous studies have reported that MSC-Ex play an important role in tissue injury repair.STUDY DESIGN, SIZE, DURATION:hucMSC and exosomes isolated from their conditioned medium were used to treat a vaginal epithelial cell line (VK2). Normal human fibroblasts (HFF-1) were used as negative control to hucMSC.PARTICIPANTS/MATERIALS, SETTING, METHODS:VK2 cells were co-cultured with hucMSC whose paracrine effect on the viability, cell cycle and cell apoptosis of VK2 vaginal epithelial cells was further assessed by the CCK-8 assay and flow cytometry. HucMSC-Ex isolated from culture medium by ultracentrifuge were characterized by transmission electron microscopy, nanoparticle tracking analysis and Western blot. HucMSC-Ex at different concentrations and HFF-1 exosomes were used to treat VK2 cells. High-throughput RNA sequencing was utilized to reveal the profile of microRNAs in hucMSC, hucMSC-Ex, HFF-1 and HFF-1 exosomes and GO analysis was applied to demonstrate their functions. To evaluate the function of these specific microRNAs in hucMSC-Ex, VK2 cells were treated with RNA-interfered-hucMSC-Ex (RNAi-hucMSC-Ex) and their proliferation was measured by Label-free Real-time Cellular Analysis System.MAIN RESULTS AND THE ROLE OF CHANCE:The study showed that hucMSC stimulate VK2 cell growth possibly through a paracrine route by promoting cell cycle and inhibiting apoptosis. Compared with control and low dose groups, hucMSC-Ex of high concentration (more than 1000 ng/ml) significantly increased VK2's growth after treatment in a dose-depended manner (P < 0.05). HucMSC-Ex raised the proportion of cells in S-phase and reduced the percentage of apoptotic cells in VK2 cells in comparison with the HFF-1 exosomes and control groups (P < 0.05). microRNAs, including miR-100 (16.92%), miR-146a (9.21%), miR-21 (6.67%), miR-221 (6.39%) and miR-143 (4.63%), were found to be specifically enriched (P < 0.05) in hucMSC-Ex and their functions concentrated on cell cycle, development and differentiation. Collectively, our findings indicate that hucMSC-Ex may play a significant role in accelerating VK2's proliferation by promoting cell cycle and inhibiting apoptosis through exosomal microRNAs in vitro.LARGE-SCALE DATA:N/A.LIMITATIONS, REASONS FOR CAUTION:Our study did not confirm the function of hucMSC-Ex or specifically enriched exosomal microRNAs in vivo. miR-100 and miR-146a are well-known immunomodulatory miRNAs that participate in the regulation of inflammatory disorders and may enhance the therapeutic effect of hucMSC-Ex by promoting the surgical injury repair after vaginal reconstruction. But whether it acts through anti-inflammatory responses needs further study.WIDER IMPLICATIONS OF THE FINDINGS:This finding supports the potential use of hucMSC-Ex as a cell-free therapy of Meyer-Rokitansky-Küster-Hauser syndrome (MRKHS) after vaginoplasty.STUDY FUNDING/COMPETING INTEREST(S):This study was supported by the Chinese National Nature Sciences Foundation (grant number 91440107, 81471416 and 81771524) and the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB19040102). All authors state that there is no conflict of interest to disclose.

Gonadotropins, including luteinizing hormone (LH) and follicle stimulating hormone (FSH), are conducive to the growth of ovarian cancer based on the gonadotropin theory' and are regulated by gonadotropin-releasing hormone (GnRH). The present study was carried out to investigate the effect of goserelin, a GnRH agonist, on the apoptosis of epithelial ovarian cancer (EOC) cells and the underlying in vitro and in vivo mechanisms. Through flow cytometry, Hoechst staining and TUNEL staining, we demonstrated that goserelin promoted the apoptosis of EOC cells both in vitro and in vivo. Through human apoptosis gene PCR array, we verified that the promotion of EOC cell apoptosis by goserelin was linked to the upregulation of members of the tumor necrosis factor (TNF) and TNF receptor superfamilies, which have been identified as downstream targets of forkhead box O1 (FOXO1). Goserelin enhanced FOXO1 expression, and siRNA-mediated knockdown of FOXO1 abrogated the induction of apoptosis by goserelin. Moreover, goserelin decreased AKT activity, and FOXO1 upregulation by goserelin was dependent on the phosphatidylinositol 3-kinase (PI3K)/AKT pathway. In vivo, the expression of key factors in the PI3K/AKT/FOXO1 pathway was consistent with that observed in vitro. In conclusion, our data suggested that goserelin may promote EOC cell apoptosis by upregulating FOXO1 through the PI3K/AKT signaling pathway. We believe that GnRH agonists may be potential antitumor agents, and key factors in the PI3K/AKT-FOXO1 pathway may also be novel therapeutic targets for the treatment of EOC.

Long non-coding RNA RAD51 antisense RNA 1 (RAD51-AS1, also known as TODRA) has been shown to be down-regulated by E2F1, a key cell cycle and apoptosis regulator, in breast cancer. Little is known regarding the role of RAD51-AS1 in disease. Here, we investigate the role of RAD51-AS1 in epithelial ovarian cancer (EOC). Using luciferase reporter and chromatin immunoprecipitation experiments, we verified RAD51-AS1 as a target of E2F1 under negative regulation in EOC. We then examined RAD51-AS1 expression in EOC samples using in situ hybridization (ISH). RAD51-AS1 was localized to the nucleus and found to be a critical marker for clinical features that significantly correlated with poor survival in EOC patients. RAD51-AS1 was also an independent prognostic factor for EOC. Overexpression of RAD51-AS1 promoted EOC cell proliferation, while silencing of RAD51-AS1 inhibited EOC cell proliferation, delayed cell cycle progression and promoted apoptosis in vitro and in vivo. RAD51-AS1 may participate in carcinogenesis via regulation of p53 and p53-related genes. Our study highlights the role of RAD51-AS1 as a prognostic marker of EOC. Based on its regulation of the tumor suppressor p53, RAD51-AS1-based therapy may represent a viable therapeutic option for EOC in the near future.

Previously, the novel oestrogen (E2)-upregulated lncRNA TC0101441, was identified by us, via microarray analysis. However, the detailed mechanism by which E2 upregulates TC0101441 and the role of TC0101441 in epithelial ovarian cancer (EOC) progression have not been elucidated. In the present study, we further analysed TC0101441, which we designated oestrogen-induced long non-coding RNA-1 (ElncRNA1). We showed that E2 transcriptionally upregulates ElncRNA1 through the oestrogen receptor α (ERα)-oestrogen response element (ERE) pathway using RNA stability assays, bioinformatics-based searches for ERE binding sites, chromatin immunoprecipitation (ChIP) assays and dual luciferase reporter assays. Clinically, ElncRNA1 levels are significantly higher in EOC tissues than in normal ovarian surface epithelium. In vitro and in vivo loss-of-function assays revealed that ElncRNA1 promotes EOC cell proliferation. This pro-proliferation effect of ElncRNA1 was partially mediated by the regulation of CDK4, CDK6 and cyclin D1. These findings provide the first evidence that E2 upregulates ElncRNA1 at the transcriptional level through the ERα-ERE pathway and that this novel E2-upregulated lncRNA has an oncogenic role in EOC growth. The placement of ElncRNA1 in the E2-ERα-ERE signalling pathway may provide greater insight into the effects of oestrogen on EOC progression from the perspective of lncRNA.

The prognostic significance of CC chemokine receptor type 7 (CCR7) for survival of patients with gastric cancer remains controversial. To investigate the impacts of CCR7 on clinicopathological findings and survival outcome in gastric cancer, we performed a meta-analysis.A comprehensive search in PubMed, Embase, the Cochrane Library, and the CNKI database (1966 to November 2015) was undertaken for relevant studies. The relative risk and hazard ratios with their 95 % confidence intervals were used as measures to investigate the correlation between CCR7 expression and clinicopathological findings and overall survival rate. Sensitivity analysis was conducted to assess the stability of outcomes.Fifteen eligible studies comprising 1697 participants were included in our analysis. The pooled relative risks indicated CCR7 expression was significantly associated with deeper tumor invasion [0.61, 95 % confidence interval (CI) 0.45-0.84, p = 0.003], advanced stage (0.47, 95 % CI 0.32-0.69, p < 0.001), vascular invasion (2.12, 95 % CI 1.20-3.73, p = 0.009), lymph node metastasis (2.00, 95 % CI 1.48-2.70, p < 0.001), and lymphatic invasion (1.98, 95 % CI 1.43-2.72, p < 0.001) but not with age, tumor size, and histological type. The pooling of hazard ratios showed a significant relationship between positive CCR7 expression and worse 5-year overall survival rate (0.46, 95 % CI 0.31-0.70, p < 0.001).Our meta-analysis indicated high CCR7 expression is likely to be a negative clinicopathological prognostic factor for patients with gastric cancer and to predict a worse long-term survival outcome.

Interleukin-37 (IL-37) is an inhibitory member of the IL-1 family of cytokines. We previously found that balanced selection maintains common variations of the human IL37 gene. However, the functional consequences of this selection have yet to be validated. Here, using cells expressing exogenous IL-37 variants, including IL-37 Ref and IL-37 Var1 and Var2, we found that the three variants of IL-37 exhibited different immunoregulatory potencies in response to immune stimulation. The protein level of IL-37 Var2 was found to be significantly less than that of IL-37 Ref or Var1, despite the comparable mRNA levels of all three variants. Further study showed that IL-37 Var2 was rapidly degraded by a proteasome-dependent mechanism mediated by enhanced polyubiquitination, leading to a transient upregulation of IL-37 Var2 after immune stimulation. Finally, when ectopically expressed in cells, human IL-37 Var2 exerted less inhibition on proinflammatory cytokine production than did other IL-37 variants. Conversely, purified extracellular IL-37 variant proteins demonstrated comparable inhibitory abilities in vitro. In conclusion, our study reveals that common genetic variants of IL37 lead to different immune-inhibitory potencies, primarily as a result of differences in IL-37 protein stability, suggesting the possible involvement of these variants in various human diseases.

UHRF1 is an important epigenetic regulator for maintenance DNA methylation. UHRF1 recognizes hemi-methylated DNA (hm-DNA) and trimethylation of histone H3K9 (H3K9me3), but the regulatory mechanism remains unknown. Here we show that UHRF1 adopts a closed conformation, in which a C-terminal region (Spacer) binds to the tandem Tudor domain (TTD) and inhibits H3K9me3 recognition, whereas the SET-and-RING-associated (SRA) domain binds to the plant homeodomain (PHD) and inhibits H3R2 recognition. Hm-DNA impairs the intramolecular interactions and promotes H3K9me3 recognition by TTD-PHD. The Spacer also facilitates UHRF1-DNMT1 interaction and enhances hm-DNA-binding affinity of the SRA. When TTD-PHD binds to H3K9me3, SRA-Spacer may exist in a dynamic equilibrium: either recognizes hm-DNA or recruits DNMT1 to chromatin. Our study reveals the mechanism for regulation of H3K9me3 and hm-DNA recognition by URHF1.