Streptococcus anginosus promotes gastric inflammation, atrophy, and tumorigenesis in mice.

Streptococcus anginosus (S. anginosus) was enriched in the gastric mucosa of patients with gastric cancer (GC). Here, we show that S. anginosus colonized the mouse stomach and induced acute gastritis. S. anginosus infection spontaneously induced progressive chronic gastritis, parietal cell atrophy, mucinous metaplasia, and dysplasia in conventional mice, and the findings were confirmed in germ-free mice. In addition, S. anginosus accelerated GC progression in carcinogen-induced gastric tumorigenesis and YTN16 GC cell allografts. Consistently, S. anginosus disrupted gastric barrier function, promoted cell proliferation, and inhibited apoptosis. Mechanistically, we identified an S. anginosus surface protein, TMPC, that interacts with Annexin A2 (ANXA2) receptor on gastric epithelial cells. Interaction of TMPC with ANXA2 mediated attachment and colonization of S. anginosus and induced mitogen-activated protein kinase (MAPK) activation. ANXA2 knockout abrogated the induction of MAPK by S. anginosus. Thus, this study reveals S. anginosus as a pathogen that promotes gastric tumorigenesis via direct interactions with gastric epithelial cells in the TMPC-ANXA2-MAPK axis.

ALKBH5 Drives Immune Suppression Via Targeting AXIN2 to Promote Colorectal Cancer and Is a Target for Boosting Immunotherapy.

BACKGROUND & AIMS: Immune checkpoint blockade therapy benefits only a small subset of patients with colorectal cancer (CRC), and identification of CRC-intrinsic events modulating immune checkpoint blockade efficacy is an unmet need. We found that AlkB homolog 5 (ALKBH5), an RNA N6-methyladenosine eraser, drives immunosuppression and is a molecular target to boost immune checkpoint blockade therapy in CRC. METHODS: Clinical significance of ALKBH5 was evaluated in human samples (n = 205). Function of ALKBH5 was investigated in allografts, CD34+ humanized mice, and Alkbh5 knockin mice. Immunity change was determined by means of flow cytometry, immunofluorescence, and functional investigation. Methylated RNA immunoprecipitation sequencing and RNA sequencing were used to identify ALKBH5 targets. Vesicle-like nanoparticle-encapsulated ALKBH5-small interfering RNA was constructed for targeting ALKBH5 in vivo. RESULTS: High ALKBH5 expression predicts poor prognosis in CRC. ALKBH5 induced myeloid-derived suppressor cell accumulation but reduced natural killer cells and cytotoxic CD8+ T cells to induce colorectal tumorigenesis in allografts, CD34+ humanized mice, and intestine-specific Alkbh5 knockin mice. Mechanistically, AXIN2, a Wnt suppressor, was identified as a target of ALKBH5. ALKBH5 binds and demethylates AXIN2 messenger RNA, which caused its dissociation from N6-methyladenosine reader IGF2BP1 and degradation, resulting in hyperactivated Wnt/ß-catenin. Subsequently, Wnt/ß-catenin targets, including Dickkopf-related protein 1 (DKK1) were induced by ALKBH5. ALKBH5-induced DKK1 recruited myeloid-derived suppressor cells to drive immunosuppression in CRC, and this effect was abolished by anti-DKK1 in vitro and in vivo. Finally, vesicle-like nanoparticle-encapsulated ALKBH5-small interfering RNA, or anti-DKK1 potentiated anti-PD1 treatment in suppressing CRC growth by enhancing antitumor immunity. CONCLUSIONS: This study identified an ALKBH5-N6-methyladenosine-AXIN2-Wnt-DKK1 axis in CRC, which drives immune suppression to facilitate tumorigenesis. Targeting of ALKBH5 is a promising strategy for sensitizing CRC to immunotherapy.

Targeting m6A reader YTHDF1 augments antitumour immunity and boosts anti-PD-1 efficacy in colorectal cancer.

OBJECTIVE: The role of N6-methyladenosine (m6A) in tumour immune microenvironment (TIME) remains understudied. Here, we elucidate function and mechanism of YTH N6-methyladenosine RNA binding protein 1 (YTHDF1) in colorectal cancer (CRC) TIME. DESIGN: Clinical significance of YTHDF1 was assessed in tissue microarrays (N=408) and TCGA (N=526) cohorts. YTHDF1 function was determined in syngeneic tumours, intestine-specific Ythdf1 knockin mice, and humanised mice. Single-cell RNA-seq (scRNA-seq) was employed to profile TIME. Methylated RNA immunoprecipitation sequencing (MeRIP-seq), RNA sequencing (RNA-seq) and ribosome sequencing (Ribo-seq) were used to identify YTHDF1 direct targets. Vesicle-like nanoparticles (VNPs)-encapsulated YTHDF1-siRNA was used for YTHDF1 silencing in vivo. RESULTS: YTHDF1 expression negatively correlated with interferon-γ gene signature in TCGA-CRC. Concordantly, YTHDF1 protein negatively correlated with CD8+ T-cell infiltration in independent tissue microarrays cohorts, implying its role in TIME. Genetic depletion of Ythdf1 augmented antitumour immunity in CT26 (MSS-CRC) and MC38 (MSI-H-CRC) syngeneic tumours, while Ythdf1 knockin promoted an immunosuppressive TIME facilitating CRC in azoxymethane-dextran sulphate-sodium or ApcMin/+ models. scRNA-seq identified reduction of myeloid-derived suppressor cells (MDSCs), concomitant with increased cytotoxic T cells in Ythdf1 knockout tumours. Integrated MeRIP-seq, RNA-seq and Ribo-seq revealed p65/Rela as a YTHDF1 target. YTHDF1 promoted p65 translation to upregulate CXCL1, which increased MDSC migration via CXCL1-CXCR2 axis. Increased MSDCs in turn antagonised functional CD8+ T cells in TIME. Importantly, targeting YTHDF1 by CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) or VNPs-siYTHDF1 boosted anti-PD1 efficacy in MSI-H CRC, and overcame anti-PD1 resistance in MSS CRC. CONCLUSION: YTHDF1 impairs antitumour immunity via an m6A-p65-CXCL1/CXCR2 axis to promote CRC and serves as a therapeutic target in immune checkpoint blockade therapy.

Systematic review of machine learning-based radiomics approach for predicting microsatellite instability status in colorectal cancer.

This study aimed to systematically summarize the performance of the machine learning-based radiomics models in the prediction of microsatellite instability (MSI) in patients with colorectal cancer (CRC). It was conducted according to the preferred reporting items for a systematic review and meta-analysis of diagnostic test accuracy studies (PRISMA-DTA) guideline and was registered at the PROSPERO website with an identifier CRD42022295787. Systematic literature searching was conducted in databases of PubMed, Embase, Web of Science, and Cochrane Library up to November 10, 2022. Research which applied radiomics analysis on preoperative CT/MRI/PET-CT images for predicting the MSI status in CRC patients with no history of anti-tumor therapies was eligible. The radiomics quality score (RQS) and Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) were applied to evaluate the research quality (full score 100%). Twelve studies with 4,320 patients were included. All studies were retrospective, and only four had an external validation cohort. The median incidence of MSI was 19% (range 8-34%). The area under the receiver operator curve of the models ranged from 0.78 to 0.96 (median 0.83) in the external validation cohort. The median sensitivity was 0.76 (range 0.32-1.00), and the median specificity was 0.87 (range 0.69-1.00). The median RQS score was 38% (range 14-50%), and half of the studies showed high risk in patient selection as evaluated by QUADAS-2. In conclusion, while radiomics based on pretreatment imaging modalities had a high performance in the prediction of MSI status in CRC, so far it does not appear to be ready for clinical use due to insufficient methodological quality.

The α-tubulin of Laodelphax striatellus mediates the passage of rice stripe virus (RSV) and enhances horizontal transmission.

Rice stripe virus (RSV, genus Tenuivirus, family Phenuiviridae) is the causal agent of rice stripe disease transmitted by the small brown planthopper (SBPH, Laodelphax striatellus) in a persistent propagative manner. The midgut and salivary glands of SBPH are the first and last barriers to the viral circulation and transmission processes, respectively; however, the precise mechanisms used by RSV to cross these organs and transmit to rice plants have not been fully elucidated. We obtained the full-length cDNA sequence of L. striatellus α-tubulin 2 (LsTUB) and found that RSV infection increased the level of LsTUB in vivo. Furthermore, LsTUB was shown to co-localize with RSV nonstructural protein 3 (NS3) in vivo and bound NS3 at positions 74-76 and 80-82 in vitro. Transient gene silencing of LsTUB expression caused a significant reduction in detectable RSV loads and viral NS3 expression levels, but had no effect on NS3 silencing suppressor activity and viral replication in insect cells. However, suppression of LsTUB attenuated viral spread in the bodies of SBPHs and decreased RSV transmission rates to rice plants. Electrical penetration graphs (EPG) showed that LsTUB knockdown by RNAi did not impact SBPH feeding; therefore, the reduction in RSV transmission rates was likely caused by a decrease in viral loads inside the planthopper. These findings suggest that LsTUB mediates the passage of RSV through midgut and salivary glands and leads to successful horizontal transmission.

Comparative Transcriptome Analysis of Chemoreception Organs of Laodelphax striatellus in Response to Rice Stripe Virus Infection.

Many vector-borne viruses possess the ability to manipulate vector behaviors to facilitate their transmission. There is evidence that the mechanism of this phenomenon has been described in part as direct manipulation through regulating vector chemosensation. Rice stripe virus (RSV) is transmitted by the small brown planthopper, Laodelphax striatellus (Fallen), in a persistent, circulative-propagative manner. The effect of RSV infection on the olfactory system of L. striatellus has not been fully elucidated. Here, we employed transcriptomic sequencing to analyze gene expression profiles in antennae, legs and heads (without antennae) from L. striatellus females and males with/without RSV infection. Comparisons of the differentially expressed genes (DEGs) among antennae, legs and heads indicated that tissue-specific changes in the gene expression profile were greater than sex-specific changes. A total of 17 olfactory related genes were differentially expressed in viruliferous antennae as compared to nonviruliferous antennae, including LstrOBP4/9, LstrCSP1/2/5, LstrGR28a/43a/43a-1, LstrIR1/2/NMDA1, LstrOR67/85e/56a/94 and LstrSNMP2/2-2. There are 23 olfactory related DEGs between viruliferous and nonviruliferous legs, including LstrOBP2/3/4/12/13, LstrCSP13/5/10, LstrIR1/2/Delta2/Delta2-1/kainate2/NMDA2, LstrOR12/21/31/68 and LstrORco. A low number of olfactory related DEGs were found between viruliferous and nonviruliferous heads, including LstrCSP1, LstrOBP2, LstrOR67 and LstrSNMP2-2. Among these DEGs, the expression patterns of LstrOBP2, LstrOBP3 and LstrOBP9 in three tissues was validated by quantitative real-time PCR. The demonstration of overall changes in the genes in L. striatellus' chemoreception organs in response to RSV infection would not only improve our understanding of the effect of RSV on the olfactory related genes of insect vectors but also provide insights into developing approaches to control the plant virus transmission and spread as well as pest management in the future.

Transgelin interacts with PARP1 in human colon cancer cells.

BACKGROUND: Transgelin, an actin-binding protein, is associated with cytoskeleton remodeling. Findings from our previous studies demonstrated that transgelin was up-regulated in node-positive colorectal cancer (CRC) versus node-negative disease. Over-expression of TAGLN affected the expression of 256 downstream transcripts and increased the metastatic potential of colon cancer cells in vitro and in vivo. This study aims to explore the mechanisms through which transgelin participates in the metastasis of colon cancer cells. METHODS: Immunofluorescence and immunoblotting analysis were used to determine the cellular localization of endogenous and exogenous transgelin in colon cancer cells. Co-immunoprecipitation and subsequently high-performance liquid chromatography/tandem mass spectrometry were performed to identify the proteins that were potentially interacting with transgelin. The 256 downstream transcripts regulated by transgelin were analyzed with bioinformatics methods to discriminate the specific key genes and signaling pathways. The Gene-Cloud of Biotechnology Information (GCBI) tools were used to predict the potential transcription factors (TFs) for the key genes. The predicted TFs corresponded to the proteins identified to interact with transgelin. The interaction between transgelin and the TFs was verified by co-immunoprecipitation and immunofluorescence. RESULTS: Transgelin was found to localize in both the cytoplasm and nucleus of the colon cancer cells. Approximately 297 proteins were identified to interact with transgelin. The overexpression of TAGLN led to the differential expression of 184 downstream genes. Network topology analysis discriminated seven key genes, including CALM1, MYO1F, NCKIPSD, PLK4, RAC1, WAS and WIPF1, which are mostly involved in the Rho signaling pathway. Poly (ADP-ribose) polymerase-1 (PARP1) was predicted as the unique TF for the key genes and concurrently corresponded to the DNA-binding proteins potentially interacting with transgelin. The interaction between PARP1 and transgelin in human RKO colon cancer cells was further validated by immunoprecipitation and immunofluorescence assays. CONCLUSIONS: Our results suggest that transgelin binds to PARP1 and regulates the expression of downstream key genes, which are mainly involved in the Rho signaling pathway, and thus participates in the metastasis of colon cancer.

Genetic characterization of a novel G9P[23] rotavirus A strain identified in southwestern China with evidence of a reassortment event between human and porcine strains.

Group A rotaviruses (RVAs) are important zoonotic pathogens that cause intestinal disease in humans and other mammals. In this study, the novel strain RVA/Pig/China/SC11/2017/G9P[23](SC11) was isolated from fecal samples from a pig farm in Sichuan province, southwestern China. The complete genome was found to be 18,347 bp in length with 11 segments. The genotype constellation of strain SC11 was G9-P[23]-I12-R1-C1-M1-A1-N1-T1-E1-H1, according to whole-genome sequencing analysis. The VP1, VP2, VP4, VP6, NSP1-NSP3, and NSP5 genes of RVA strain SC11 were found to be closely related to those of porcine and/or porcine-like human RVAs. Meanwhile, the VP7 and NSP4 genes of strain SC11 were closely related to genes of human RVAs. However, it was difficult to pinpoint the porcine or human origin of the VP3 gene of strain SC11 based on the available data. These results showed that SC11 originated from a natural reassortment event between human and pig RVA strains, and crossover points for recombination were identified at nucleotides (nt) 109-806 of NSP2. This is the first report of such a reassortant and recombinant RVA strain in the southwestern region of China.

Tn6450, a Novel Multidrug Resistance Transposon Characterized in a Proteus mirabilis Isolate from Chicken in China.

A novel 65.8-kb multidrug resistance transposon, designated Tn6450, was characterized in a Proteus mirabilis isolate from chicken in China. Tn6450 contains 18 different antimicrobial resistance genes, including cephalosporinase gene blaDHA-1 and fluoroquinolone resistance genes qnrA1 and aac(6')-Ib-cr It carries a class 1/2 hybrid integron composed of intI2 and a 3' conserved segment of the class 1 integron. Tn6450 is derived from Tn7 via acquisition of new mobile elements and resistance genes.

Induction of innate immune response following introduction of infectious bronchitis virus (IBV) in the trachea and renal tissues of chickens.

Infectious bronchitis (IB) is a highly contagious respiratory disease of chickens, which is caused by the infectious bronchitis virus (IBV). The innate immune response is crucial for antiviral infections and revealing the pathogenic mechanisms of IBV. In this study, we presents an evaluation of interferon (I, II and III IFNs) in renal and tracheal samples from chickens experimentally infected previously vaccinated or not. The results suggest differential expression of chicken interferon, among them type I IFN elaborate a major role in fighting off virus. And vaccine confers greater induction ability of innate immunity thereby vaccination prior infection occurs might be necessary. Above all, we found that IFN-λ also have an effect on IBV infection in trachea besides many other respiratory virus. This study provides the first comprehensive analysis of host-virus interactions of IBV with chicken innate immune response mediated by interferon in various groups.

Analysis of the influence of living environment and age on vaginal fungal microbiome in giant pandas (Ailuropoda melanoleuca) by high throughput sequencing.

A recent study has described the normal vaginal bacterial community in giant pandas, but there is a lack of knowledge of the fungal community residing in the vagina of giant pandas. In order to comprehensively understand the vaginal fungal microbial diversity and abundance in giant pandas, high throughput sequencing was used to analyse the ITS1 region, based on thirteen samples taken from the pandas' vaginas, which were grouped by sampling points and age. The results showed that the most abundant phyla were Basidiomycota (73.37%), followed by Ascomycota (20.04%), Zygomycota (5.23%), Glomeromycota (0.014%) and Chytridiomycota (0.006%). At the genus level, Guehomyces (37.92%) was the most abundant, followed by Cladosporium (9.072%), Trichosporon (6.2%) and Mucor (4.97%). Furthermore, Candida only accounted for a low percentage of the vaginal fungal community. With the saturation of rarefaction curves and fungal diversity indices, the samples from Dujiangyan and Chungking Safari Park (DC group) showed a higher fungal species richness and diversity than other living environments. Shannon diversity indices showed significant difference between group WL (Wolong nature reserve) and DC (P < .05). Additionally, a higher diversity was found in ten to fifteen years old (Group 2) than other groups. Group 2 and Group 3 displayed significant differences in the diversities of their vaginal fungal communities (P < .05). These data that has been collected from this research will be helpful for further study to improve the reproductive status of giant pandas.

Prevalence of antimicrobial resistance and integron gene cassettes in Escherichia coli isolated from yaks (Poephagus grunniens) in Aba Tibetan Autonomous Prefecture, China.

BACKGROUND: Escherichia coli (E. coli) is one of the most relevant opportunistic pathogenic bacteria as it may cause severe morbidity and mortality in yaks (poephagus grunniens). In recent years, several kinds of antibiotics have been widely used in Tibetan areas to treat the bacterial diseases, resulting in serious repercussions on the bacterial antibiotic resistance in yaks. This investigation was conducted in order to determine the prevalence of antimicrobial resistance and integron gene cassettes in E. coli isolated from yaks in Aba Tibetan Autonomous Prefecture (Aba TAP), China. METHODS: A total of 278 non-duplicated fresh samples were collected from the yaks in Aba TAP for the isolation and identification of E. coli isolates. Antimicrobial susceptibility testing is performed by using the disc diffusion method according to the Clinical and Laboratory Standards Institute guidelines (CLSI, 2013). Various antibiotic resistance genes and integron gene cassettes were detected by polymerase chain reaction (PCR) and sequencing. RESULTS: Overall, a total of 228 E. coli bacteria were isolated from the fresh faeces of yaks in four different geographical regions. 58% of those isolates showed multi-drug resistance capabilities (MDR) in our study. These isolated bacteria showed a high resistance rate to streptomycin (84%), cefotaxime (79%), amikacin (61%) and trimethoprim-sulfamethoxazole (54%). The most common antimicrobial resistance genes in the isolates were blaCTX-M, sul1, aph (3')-IIa, aac (3)-IIa, aac (6')-Ib, tetB, with respective detection rates of 65%, 46%, 35%, 13%, 11%, and 10%. Furthermore, 66% and 6% of the strains carried Class 1 and 2 integrons, respectively. However, the class 3 integron was not detected. Gene cassette arrays in the class 1 integron included aadA1, aadA7, aadA5, aadA17, dfrA1, dfrA5, dfrA1-aadA1, dfrA12-aadA2 and dfrA17-aadA5. The most prevalent gene cassette was aadA1 (20%). For the class 2 integron, dfrA1-sat2-aadA1 (6%) and dfrA1-sat1-aadA1 (0.4%) were also detected as part of this research. CONCLUSION: High multi-drug resistance rates have been discovered, as well as a prevalence of antibiotic resistance genes and integron gene cassettes in the E. coli isolated from the faeces of yak. This might create a potential problem for treatment of the yaks' bacterial infections as well as food hygiene for humans. It is therefore urgently necessary to begin continuous surveillance and analysis of antibiotic resistance and integron cassettes in other bacteria from yaks.

MicroRNA transcriptome analysis in chicken kidneys in response to differing virulent infectious bronchitis virus infections.

Infectious bronchitis virus (IBV) can cause a highly contagious and acute respiratory disease in poultry. MicroRNAs (miRNAs) have emerged as a class of crucial regulators for gene expression and are involved in the regulation of virus defence and immunological processes. To understand miRNA regulation in chickens in response to IBV infection, high-throughput sequencing was performed to compare the small RNA libraries from the kidneys of chicken infected with SCK2, SCDY2 and LDT3-A. By comparing these data to healthy chickens, a total of 58 differentially expressed (DE) miRNAs were identified. The DE miRNAs were further classified into five miRNA expression patterns (up or down regulation compared to control). Using Gene Ontology (GO) enrichment prediction, the DE miRNAs were shown to be mostly associated with metabolic processes, catalytic activities, gene expression, binding activities and immune responses. Seven highly expressed miRNAs (gga-miR-30d, gga-miR-1454, gga-miR-7b, gga-miR-215-5p, gga-miR-1a-3p, gga-miR-3538 and gga-miR-2954) were selected for miRNA-mRNA conjoint analysis. Furthermore, the miRNAs inversely correlated with the corresponding target gene mRNAs. These seven miRNAs were considered to play an important role in IBV-host interactions and the differing virulence of IBV strains. This is the first demonstration that infection with different virulent IBVs elicits different expression of miRNAs in chicken kidneys; this expression also seems to be associated with the virulence of IBV. These results are significant for the study of immune responses to infection with different virulent IBVs mediated by miRNAs as well as the interaction between the chicken host and IBV.

Exploring tumor heterogeneity in colorectal liver metastases by imaging: Unsupervised machine learning of preoperative CT radiomics features for prognostic stratification.

OBJECTIVES: This study aimed to investigate tumor heterogeneity of colorectal liver metastases (CRLM) and stratify the patients into different risk groups of prognoses following liver resection by applying an unsupervised radiomics machine-learning approach to preoperative CT images. METHODS: This retrospective study retrieved clinical information and CT images of 197 patients with CRLM from The Cancer Imaging Archive (TCIA) database. Radiomics features were extracted from a segmented liver lesion identified at the portal venous phase. Those features which showed high stability, non-redundancy, and indicative information were selected. An unsupervised consensus clustering analysis on these features was adopted to identify subgroups of CRLM patients. Overall survival (OS), disease-free survival (DFS), and liver-specific DFS were compared between the identified subgroups. Cox regression analysis was applied to evaluate prognostic risk factors. RESULTS: A total of 851 radiomics features were extracted, and 56 robust features were finally selected for unsupervised clustering analysis which identified two distinct subgroups (96 and 101 patients respectively). There were significant differences in the OS, DFS, and liver-specific DFS between the subgroups (all log-rank p < 0.05). The subgroup with worse outcome using the proposed radiomics model was consistently associated with shorter OS, DFS, and liver-specific DFS, with hazard ratios of 1.78 (95 %CI: 1.12-2.83), 1.72 (95 %CI: 1.16-2.54), and 1.59 (95 %CI: 1.10-2.31), respectively. The general performance of this radiomics model outperformed the traditional Clinical Risk Score and Tumor Burden Score in the prognosis prediction after surgery for CRLM. CONCLUSION: Radiomics features derived from preoperative CT images can reveal the heterogeneity of CRLM and stratify the patients with CRLM into subgroups with significantly different clinical outcomes.

Proteome-wide profiling reveals dysregulated molecular features and accelerated aging in osteoporosis: A 9.8-year prospective study.

The role of circulatory proteomics in osteoporosis is unclear. Proteome-wide profiling holds the potential to offer mechanistic insights into osteoporosis. Serum proteome with 413 proteins was profiled by liquid chromatography-tandem mass spectrometry (LC-MS/MS) at baseline, and the 2nd, and 3rd follow-ups (7704 person-tests) in the prospective Chinese cohorts with 9.8 follow-up years: discovery cohort (n = 1785) and internal validation cohort (n = 1630). Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry (DXA) at follow-ups 1 through 3 at lumbar spine (LS) and femoral neck (FN). We used the Light Gradient Boosting Machine (LightGBM) to identify the osteoporosis (OP)-related proteomic features. The relationships between serum proteins and BMD in the two cohorts were estimated by linear mixed-effects model (LMM). Meta-analysis was then performed to explore the combined associations. We identified 53 proteins associated with osteoporosis using LightGBM, and a meta-analysis showed that 22 of these proteins illuminated a significant correlation with BMD (p < 0.05). The most common proteins among them were PHLD, SAMP, PEDF, HPTR, APOA1, SHBG, CO6, A2MG, CBPN, RAIN APOD, and THBG. The identified proteins were used to generate the biological age (BA) of bone. Each 1 SD-year increase in KDM-Proage was associated with higher risk of LS-OP (hazard ratio [HR], 1.25; 95% CI, 1.14-1.36, p = 4.96 × 10-06 ), and FN-OP (HR, 1.13; 95% CI, 1.02-1.23, p = 9.71 × 10-03 ). The findings uncovered that the apolipoproteins, zymoproteins, complements, and binding proteins presented new mechanistic insights into osteoporosis. Serum proteomics could be a crucial indicator for evaluating bone aging.

RUVBL1/2 Blockade Targets YTHDF1 Activity to Suppress m6A-Dependent Oncogenic Translation and Colorectal Tumorigenesis.

The N6-methyladenosine (m6A) RNA binding protein YTHDF1 is frequently overexpressed in colorectal cancer (CRC) and drives chemotherapeutic resistance. To systematically identify druggable targets in CRC with high expression of YTHDF1, we employed a CRISPR/Cas9 screening strategy that revealed RUVBL1 and RUVBL2 as putative targets.RUVBL1/2 were overexpressed in primary CRC samples and represented independent predictors of poor patient prognosis. Functionally, loss of RUVBL1/2 preferentially impaired the growth ofYTHDF1-high CRC cells, patient-derived primary CRC organoids, and subcutaneous xenografts. Mechanistically, YTHFD1 and RUVBL1/2 formed a positive feed-forward circuit to accelerate oncogenic translation. YTHDF1 bound to m6A-modified RUVBL1/2 mRNA to promote translation initiation and protein expression. Co-IP and mass spectrometry identified that RUVBL1/2 reciprocally interacted with YTHDF1 at 40S translation initiation complexes. Consequently, RUVBL1/2 depletion stalled YTHDF1-driven oncogenic translation and nascent protein biosynthesis, leading to proliferative arrest and apoptosis. Ribo-seq revealed that RUVBL1/2 loss impaired the activation of MAPK, RAS and PI3K-AKT signaling induced by YTHDF1. Finally, blockade of RUVBL1/2 by the pharmacological inhibitor CB6644 or vesicle-like nanoparticle-encapsulated siRNAs preferentially arrested the growth of YTHDF1-expressing CRC in vitro and in vivo. Together, this study uncovered that RUVBL1/2 are potential prognostic markers and druggable targets that regulate protein translation in YTHDF1-high CRC.

Lactobacillus acidophilus suppresses non-alcoholic fatty liver disease-associated hepatocellular carcinoma through producing valeric acid.

BACKGROUND: Gut probiotic depletion is associated with non-alcoholic fatty liver disease-associated hepatocellular carcinoma (NAFLD-HCC). Here, we investigated the prophylactic potential of Lactobacillus acidophilus against NAFLD-HCC. METHODS: NAFLD-HCC conventional and germ-free mice were established by diethylnitrosamine (DEN) injection with feeding of high-fat high-cholesterol (HFHC) or choline-deficient high-fat (CDHF) diet. Orthotopic NAFLD-HCC allografts were established by intrahepatic injection of murine HCC cells with HFHC feeding. Metabolomic profiling was performed using liquid chromatography-mass spectrometry. Biological functions of L. acidophilus conditional medium (L.a CM) and metabolites were determined in NAFLD-HCC human cells and mouse organoids. FINDINGS: L. acidophilus supplementation suppressed NAFLD-HCC formation in HFHC-fed DEN-treated mice. This was confirmed in orthotopic allografts and germ-free tumourigenesis mice. L.a CM inhibited the growth of NAFLD-HCC human cells and mouse organoids. The protective function of L. acidophilus was attributed to its non-protein small molecules. By metabolomic profiling, valeric acid was the top enriched metabolite in L.a CM and its upregulation was verified in liver and portal vein of L. acidophilus-treated mice. The protective function of valeric acid was demonstrated in NAFLD-HCC human cells and mouse organoids. Valeric acid significantly suppressed NAFLD-HCC formation in HFHC-fed DEN-treated mice, accompanied by improved intestinal barrier integrity. This was confirmed in another NAFLD-HCC mouse model induced by CDHF diet and DEN. Mechanistically, valeric acid bound to hepatocytic surface receptor GPR41/43 to inhibit Rho-GTPase pathway, thereby ablating NAFLD-HCC. INTERPRETATION: L. acidophilus exhibits anti-tumourigenic effect in mice by secreting valeric acid. Probiotic supplementation is a potential prophylactic of NAFLD-HCC. FUNDING: Shown in Acknowledgments.

The associations of erythrocyte membrane polyunsaturated fatty acids with skeletal muscle loss: A prospective cohort study.

BACKGROUND & AIMS: Polyunsaturated fatty acids (PUFAs) may play a vital role in maintaining skeletal muscle mass in the aged population. This study investigated the longitudinal relationship between the concentrations of erythrocyte membrane PUFAs and age-related changes in skeletal muscle mass over an average 6.5 years of follow-up in a Chinese middle-aged and older adult population. METHODS: A total of 1494 participants aged 57.4 ± 4.7 years were included in this study. Skeletal muscle mass was determined using dual-energy X-ray absorptiometry. Per year percent changes in the skeletal muscle index (Δ% SMI), appendicular skeletal muscle index (Δ% ASMI), and total body lean mass index (Δ% TBLMI) from baseline were calculated. Concentrations of total and individual cis-n-3 and cis-n-6 PUFAs of the erythrocyte membrane were determined using gas-liquid chromatography. RESULTS: Fully adjusted linear regression models showed that per unit increases in the concentrations of C18:2 n-6, C20:4 n-6, C22:4 n-6, and total n-6 PUFAs resulted in increases of 0.022%-0.155 % in the Δ% SMI (P for linearity: <0.001-0.006). Restricted cubic spline analysis revealed an inverted U-shaped relationship between the concentrations of C20:2 n-6, C22:5 n-3, C22:6 n-3, and total n-3 PUFAs and the Δ% SMI (P for non-linearity: <0.001-0.036). In addition, an inverted U-shaped curve was also detected for the relationships of the linoleic acid/α-linolenic acid ratio (P for non-linearity = 0.010) and n-6/n-3 PUFA ratio (P for non-linearity = 0.013) with the Δ% SMI, with the Δ% SMI peaking at respective ratios of 124.96 and 3.69. Similar associations were revealed by the Bayesian kernel machine regression model. No interaction effect was detected between the individual PUFAs for the Δ% SMI in the bivariate exposure-response analysis. Overall, similar results were observed for the Δ% ASMI and Δ% TBLMI. CONCLUSIONS: The associations between different individual PUFAs and age-related muscle loss in middle-aged and older adults may be different. Our results suggest that high concentrations of erythrocyte membrane n-6 PUFAs may be correlated with less skeletal muscle mass loss, whereas extremely high concentrations of n-3 PUFAs may be correlated with more muscle loss.

The gut microbiota-bile acid axis mediates the beneficial associations between plasma vitamin D and metabolic syndrome in Chinese adults: A prospective study.

BACKGROUND & AIMS: Previous studies have suggested that circulating 25-hydroxyvitamin D (25 [OH]D, VD) and the gut microbiota-bile acid axis play crucial roles in metabolic health. Exploring the mediating role of the gut microbiota-bile acid axis would improve our understanding of the mechanisms underlying the effects of VD on human metabolic health. This study examined the association between plasma 25(OH)D and the prevalence/incidence of metabolic syndrome (MetS) and the mediating role of the gut microbiota-bile acid axis. METHODS: This prospective study included 3180 participants with plasma 25(OH)D data at baseline and 2966 participants with a 9-year follow-up. MetS was determined every three years. The gut microbiota was analyzed by 16S rRNA sequencing in 1752 participants, and targeted bile acid metabolites in feces were further determined in 974 participants using UPLC‒MS/MS at the middle of the study. Mediating roles of microbiota and bile acids in the VD-MetS associations were analyzed using mediation/path analyses adjusted for potential confounders. RESULTS: Among the 2966 participants who were followed-up, 1520, 193, 647, and 606 were MetS-free (normal), recovered, had incident MetS, and had persistent MetS, respectively. The multivariable-adjusted ORs (95% CIs) of MetS prevalence were 0.65 (0.50, 0.84) for baseline MetS and 0.46 (0.33, 0.65) for 9-year persistent MetS in quartile 4 (compared to quartile 1) of plasma 25(OH)D (median: 37.7 vs. 19.6, ng/ml). The corresponding HR (95% CI) of 9-year MetS incidence was 0.71 (0.56, 0.90) (all P-trend < 0.05). Higher VD concentrations were associated with greater α-diversity of the gut microbiota, which was inversely correlated with MetS risk. The groups classified by VD and MetS status had significantly different ß-diversity. Ruminiclostridium-6 and Christensenellaceae R-7 group were enriched in the high-VD group and were inversely associated with MetS. However, opposite associations were observed for Lachnoclostridium and Acidaminococcus. The overlapping differential microbial score (ODMS) developed from the four differential genera explained 12.2% of the VD-MetS associations (Pmediation = 0.015). Furthermore, the fecal bile acid score created from 11 differential bile acids related to ODMS and MetS mediated 34.2% of the association between ODMS and MetS (Pmediation = 0.029). Path analyses showed that the inverse association between plasma 25(OH)D and MetS could be mediated by the gut microbiota-bile acid axis. CONCLUSIONS: The findings suggest that the gut microbiota-bile acid axis partially mediates the beneficial association between plasma 25(OH)D and the risk of persistent MetS and incident MetS in the Chinese population.

METTL3 drives NAFLD-related hepatocellular carcinoma and is a therapeutic target for boosting immunotherapy.

Non-alcoholic fatty liver disease (NAFLD) is an emerging risk factor of hepatocellular carcinoma (HCC). However, the mechanism and target therapy of NAFLD-HCC are still unclear. Here, we identify that the N6-methyladenosine (m6A) methyltransferase METTL3 promotes NAFLD-HCC. Hepatocyte-specific Mettl3 knockin exacerbated NAFLD-HCC formation, while Mettl3 knockout exerted the opposite effect in mice. Single-cell RNA sequencing revealed that METTL3 suppressed antitumor immune response by reducing granzyme B (GZMB+) and interferon gamma-positive (IFN-γ+) CD8+ T cell infiltration, thereby facilitating immune escape. Mechanistically, METTL3 mediates sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP) mRNA m6A to promote its translation, leading to the activation of cholesterol biosynthesis. This enhanced secretion of cholesterol and cholesteryl esters that impair CD8+ T cell function in the tumor microenvironment. Targeting METTL3 by single-guide RNA, nanoparticle small interfering RNA (siRNA), or pharmacological inhibitor (STM2457) in combination with anti-programmed cell death protein 1 (PD-1) synergized to reinvigorate cytotoxic CD8+ T cells and mediate tumor regression. Together, METTL3 is a therapeutic target in NAFLD-HCC, especially in conjunction with immune checkpoint blockade (ICB) therapy.