METTL14 downregulation drives S100A4+ monocyte-derived macrophages via MyD88/NF-κB pathway to promote MAFLD progression.

Without intervention, a considerable proportion of patients with metabolism-associated fatty liver disease (MAFLD) will progress from simple steatosis to metabolism-associated steatohepatitis (MASH), liver fibrosis, and even hepatocellular carcinoma. However, the molecular mechanisms that control progressive MAFLD have yet to be fully determined. Here, we unraveled that the expression of the N6-methyladenosine (m6A) methyltransferase METTL14 is remarkably downregulated in the livers of both patients and several murine models of MAFLD, whereas hepatocyte-specific depletion of this methyltransferase aggravated lipid accumulation, liver injury, and fibrosis. Conversely, hepatic Mettl14 overexpression alleviated the above pathophysiological changes in mice fed on a high-fat diet (HFD). Notably, in vivo and in vitro mechanistic studies indicated that METTL14 downregulation decreased the level of GLS2 by affecting the translation efficiency mediated by YTHDF1 in an m6A-depedent manner, which might help to form an oxidative stress microenvironment and accordingly recruit Cx3cr1+Ccr2+ monocyte-derived macrophages (Mo-macs). In detail, Cx3cr1+Ccr2+ Mo-macs can be categorized into M1-like macrophages and S100A4-positive macrophages and then further activate hepatic stellate cells (HSCs) to promote liver fibrosis. Further experiments revealed that CX3CR1 can activate the transcription of S100A4 via CX3CR1/MyD88/NF-κB signaling pathway in Cx3cr1+Ccr2+ Mo-macs. Restoration of METTL14 or GLS2, or interfering with this signal transduction pathway such as inhibiting MyD88 could ameliorate liver injuries and fibrosis. Taken together, these findings indicate potential therapies for the treatment of MAFLD progression.

Circular RNA cFAM210A, degradable by HBx, inhibits HCC tumorigenesis by suppressing YBX1 transactivation.

Hepatitis B protein x (HBx) has been reported to promote tumorigenesis in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), but the mechanism awaits further investigation. In this study, we found that cFAM210A (a circular RNA derived from the third exon of transcript NM_001098801 of the FAM210A gene; CircBase ID: hsa_circ_0003979) can be silenced by HBx. cFAM210A expression was downregulated and negatively correlated with tumorigenesis in patients with HBV-related HCC. Furthermore, cFAM210A reduced the proliferation, stemness, and tumorigenicity of HCC cells. Mechanistically, HBx increased the N6-methyladenosine (m6A) level of cFAM210A by promoting the expression of RBM15 (an m6A methyltransferase), thus inducing the degradation of cFAM210A via the YTHDF2-HRSP12-RNase P/MRP pathway. cFAM210A bound to YBX1 and inhibited its phosphorylation, suppressing its transactivation function toward MET. These findings suggest the important role of circular RNAs in HBx-induced hepatocarcinogenesis and identify cFAM210A a potential target in the prevention and treatment of HBV-related HCC.

Spatial maps of hepatocellular carcinoma transcriptomes reveal spatial expression patterns in tumor immune microenvironment.

Rationale: Hepatocellular carcinoma (HCC) is a highly heterogeneous and malignant disease with the complex immune microenvironment, which ultimately influence clinic outcomes of patients. However, the spatial expression patterns of diverse immune cells among tumor microenvironment remain to be further deciphered. Methods: Spatial transcriptomics sequencing (ST) was implemented on two portions of HCC specimens. Differentially expressed genes, cell cycle phases, epithelial-mesenchymal features, pseudo-time and immune infiltration analysis were applied to demonstrate the intratumor heterogeneity and define the specific immune-related regions, and the results were further validated by a second analysis on another ST study. In vitro and in vivo experiments were conducted to confirm the functional mechanisms of key molecules such as CCL15, CCL19 and CCL21. Clinical tissue samples were used to assess their potential prognostic and therapeutic values. Results: Totally, 7553 spots were categorized into 15 subsets by hierarchical clustering, and malignant subsets with intratumor heterogeneity phenotypes were identified. Spatial heterogeneity from distinct sectors highlights specific chemokines: CCL15 is remarkable in the core region of the carcinoma sector and facilitates the immunosuppressive microenvironment by recruiting and polarizing M2-like macrophages in vitro and in vivo; High expression of CCL15 and CD163 respectively predicts poor prognosis of HCC patients, and the combined application of them has better predictive value. CCL19 and CCL21, sharing similar spatial expression patterns, are highly-correlated and prominent in the immune infiltration enrichment and recruit CD3+ T cells and CD20+ B cells to inhibit the growth of HCC, indicating a good prognosis of HCC patients. Conclusions: Taken together, our studies preliminarily reveal intratumor heterogeneity of HCC based on ST techniques and unravel the previously unexplored spatial expression patterns in the immune microenvironment. We also highlight the clinical significance and spatial discrepancy of key molecules, providing novel insight for further developing therapeutic strategies in HCC.

Incidence and Risk Factors for Cerebrovascular-Specific Mortality in Patients with Colorectal Cancer: A Registry-Based Cohort Study Involving 563,298 Patients.

BACKGROUND: Colorectal cancer (CRC) is one of the most prevalent diseases and the second leading cause of death worldwide. However, the relationship between CRC and cerebrovascular-specific mortality (CVSM) remains elusive, and less is known about the influencing factors associated with CVSM in CRC. Here, we aimed to analyze the incidence as well as the risk factors of CVSM in CRC. METHODS: Patients with a primary CRC diagnosed between 1973 and 2015 were identified from the Surveillance Epidemiology and End Results database, with follow-up data available until 31 December 2016. Conditional standardized mortality ratios were calculated to compare the incidence of CVSM between CRC patients and the general U.S. POPULATION: Univariate and multivariate survival analyses with a competing risk model were used to interrogate the risk factors for CVSM. RESULTS: A total of 563,298 CRC individuals were included. The CVSM in CRC patients was significantly higher than the general population in all age subgroups. Among the competing causes of death in patients, the cumulative mortality caused by cerebrovascular-specific diseases steadily increased during the study period. While age, surgery, other/unknown race and tumors located at the transverse colon positively influenced CVSM on both univariate and multivariate analyses, male patients and those who had radiotherapy, chemotherapy, a more recent year (2001-2015) of diagnosis, a grade II or III CRC, rectal cancer, or multiple primary or distant tumors experienced a lower risk of CVSM. INTERPRETATION: Our data suggest a potential role for CRC in the incidence of CVSM and also identify several significant predictors of CVSM that may be helpful for risk stratification and the therapeutic optimization of cerebrovascular-specific diseases in CRC patients.

Dysregulated N6-methyladenosine (m6A) processing in hepatocellular carcinoma.

N6-methyladenosine (m6A) is the most thoroughly studied type of internal RNA modification, as this epigenetic modification is the most abundant in eukaryotic RNAs to date. This modification occurs in various types of RNAs and plays significant roles in dominant RNA-related processes, such as translation, splicing, export and degradation. These processes are catalyzed by three types of prominent enzymes: writers, erasers and readers. Increasing evidence has shown that m6A modification is vital for the regulation of gene expression, carcinogenesis, tumor progression and other abnormal changes, and recent studies have shown that m6A is important in the development of hepatocellular carcinoma (HCC). Herein, we summarize the nature and regulatory mechanisms of m6A modification, including its role in the pathogenesis of HCC and related chronic liver diseases. We also highlight the clinical significance and future strategies involving RNA m6A modifications in HCC.

The m6A mRNA demethylase FTO in granulosa cells retards FOS-dependent ovarian aging.

Multifunctional N6-methyladenosine (m6A) has been revealed to be an important epigenetic component in various physiological and pathological processes, but its role in female ovarian aging remains unclear. Thus, we demonstrated m6A demethylase FTO downregulation and the ensuing increased m6A in granulosa cells (GCs) of human aged ovaries, while FTO-knockdown GCs showed faster aging-related phenotypes mediated. Using the m6A-RNA-sequence technique (m6A-seq), increased m6A was found in the FOS-mRNA-3'UTR, which is suggested to be an erasing target of FTO that slows the degradation of FOS-mRNA to upregulate FOS expression in GCs, eventually resulting in GC-mediated ovarian aging. FTO acts as a senescence-retarding protein via m6A, and FOS knockdown significantly alleviates the aging of FTO-knockdown GCs. Altogether, the abovementioned results indicate that FTO in GCs retards FOS-dependent ovarian aging, which is a potential diagnostic and therapeutic target against ovarian aging and age-related reproductive diseases.

CD24: a marker of granulosa cell subpopulation and a mediator of ovulation.

Granulosa cells (GCs) play a critical role in driving the formation of ovarian follicles and building the cumulus-oocyte complex surrounding the ovum. We are particularly interested in assessing oocyte quality by examining the detailed gene expression profiles of human cumulus single cells. Using single-cell RNAseq techniques, we extensively investigated the single-cell transcriptomes of the cumulus GC populations from two women with normal ovarian function. This allowed us to elucidate the endogenous heterogeneity of GCs by uncovering the hidden GC subpopulation. The subsequent validation results suggest that CD24(+) GCs are essential for triggering ovulation. Treatment with human chorionic gonadotropin (hCG) significantly increases the expression of CD24 in GCs. CD24 in cultured human GCs is associated with hCG-induced upregulation of prostaglandin synthase (ARK1C1, PTGS2, PTGES, and PLA2G4A) and prostaglandin transporter (SLCO2A1 and ABCC4) expression, through supporting the EGFR-ERK1/2 pathway. In addition, it was observed that the fraction of CD24(+) cumulus GCs decreases in PCOS patients compared to that of controls. Altogether, the results support the finding that CD24 is an important mediator of ovulation and that it may also be used for therapeutic target of ovulatory disorders.

The RNA-binding protein RBM3 promotes cell proliferation in hepatocellular carcinoma by regulating circular RNA SCD-circRNA 2 production.

BACKGROUND: With the development of RNA-seq technology, tens of thousands of circular RNAs (circRNAs), a novel class of RNAs, have been identified. However, little is known about circRNA formation and biogenesis in hepatocellular carcinoma (HCC). METHODS: We performed ribosomal-depleted RNA-seq profiling of HCC and para-carcinoma tissues and analyzed the expression of a hotspot circRNA derived from the 3'UTR of the stearoyl-CoA desaturase (SCD) gene, termed SCD-circRNA 2. FINDINGS: It was significantly upregulated in HCC and correlated with poor patient prognosis. Moreover, we observed that the production of SCD-circRNA 2 was dynamically regulated by RNA-binding protein 3 (RBM3). RBM3 overexpression was indicative of a short recurrence-free survival and poor overall survival for HCC patients. Furthermore, by modulating the RBM3 or SCD-circRNA 2 levels, we found that RBM3 promoted the HCC cell proliferation in a SCD-circRNA 2 dependent manner. INTERPRETATION: Herein, we report that RBM3 is crucial for the SCD-circRNA 2 formation in HCC cells, which not only provides mechanistic insights into cancer-related circRNA dysregulation but also establishes RBM3 as an oncogene with both therapeutic potential and prognostic value. FUND: This work was supported by the National Key Research and Development Program of China (2016YFC1302303), the National Natural Science Foundation of China (Grant No. 81672345 and 81,402,269). The funders did not have any roles in study design, data collection, data analysis, interpretation, writing of the report.

Role of interleukin-17 in the pathogenesis of perianal abscess and anal fistula: a clinical study on 50 patients with perianal abscess.

BACKGROUND: To investigate the role of interleukin (IL)-17 in tissue and peripheral blood of perianal abscess and anal fistula. METHODS: Patients with primary perianal abscess (n = 50) admitted to Jinhua Municipal Central Hospital between March 2003 and August 2004 were enrolled. Fifty patients with mixed haemorrhoids, who showed no perianal abscess or anal fistula, were also recruited as the control. After surgery, patients were followed up for 6 months. Protein and gene expression of IL-17 was determined in surgically harvested anal tissues and peripheral blood, respectively. The relationship between IL-17 and clinical pathological features were analysed. RESULTS: As shown by immunohistochemistry of anorectal tissues, the positive rate of IL-17 protein was higher in the perianal abscess group than in the control group. In patients with perianal abscess, the expression of IL-17 significantly correlated with the diameter of the abscess (P = 0.013), the wound surface healing time (P = 0.010) and the progression into anal fistula (P = 0.003). For the gene expression of IL-17 in peripheral blood cells, the level was significantly higher in patients with perianal abscess comparing to the control group (0.4350 ± 0.1190 versus 0.1785 ± 0.1230, P ≤ 0.001). Comparing to the recovery group, patients with their perianal abscess progressed to anal fistula showed higher levels of IL-17 gene expression (P = 0.014). CONCLUSIONS: Expression of IL-17 was increased in the anorectal tissues and peripheral blood of patients with perianal abscess and anal fistula. IL-17 may play an important role in the pathogenesis of perianal abscess and anal fistula.

Coupled molybdenum carbide and reduced graphene oxide electrocatalysts for efficient hydrogen evolution.

Electrochemical water splitting is one of the most economical and sustainable methods for large-scale hydrogen production. However, the development of low-cost and earth-abundant non-noble-metal catalysts for the hydrogen evolution reaction remains a challenge. Here we report a two-dimensional coupled hybrid of molybdenum carbide and reduced graphene oxide with a ternary polyoxometalate-polypyrrole/reduced graphene oxide nanocomposite as a precursor. The hybrid exhibits outstanding electrocatalytic activity for the hydrogen evolution reaction and excellent stability in acidic media, which is, to the best of our knowledge, the best among these reported non-noble-metal catalysts. Theoretical calculations on the basis of density functional theory reveal that the active sites for hydrogen evolution stem from the pyridinic nitrogens, as well as the carbon atoms, in the graphene. In a proof-of-concept trial, an electrocatalyst for hydrogen evolution is fabricated, which may open new avenues for the design of nanomaterials utilizing POMs/conducting polymer/reduced-graphene oxide nanocomposites.

Postoperative initial single fungal discitis progressively spreading to adjacent multiple segments after lumbar discectomy.

OBJECTIVE: To report multiple cases and investigate etiology of initially single fungal spondylodiscitis that progressively spread to adjacent segments following lumbar discectomy, resulting in multiple spinal involvements. METHODS: From January 2005 to May 2013, ten adult patients were admitted or referred to our institution with postoperative discitis. Fungal infections were confirmed by microbiologic and pathologic examinations. The clinical appearance, radiographic features, and treatments of this pathology were investigated. RESULTS: All the patients were previously healthy. The average interval between the occurrence of symptoms and primary lumbar discectomy was 61 days (range, 15-120 days). All the patients were treated with anterior surgical debridement, interbody fusion, and prolonged antifungal therapy. Three patients additionally received combined posterior instrumented fusion. Despite aggressive surgical debridement and antifungal therapy, spread of the infections to adjacent multiple discs was observed. No deaths, severe neurologic deficits, or deterioration of neurologic status were noted. The infections were completely resolved in all cases with spontaneous fusion within an average follow-up of 32.4 months. CONCLUSION: Fungal spondylodiscitis after surgery represents an intractable and troublesome complication, and surgical debridement may not impede the progression of the infection in cases where an insufficient course of antifungal treatment is administered. Such cases may require prolonged antifungal treatment with regular consultation by an infectious disease specialist.