Association between metabolites in tryptophan-kynurenine pathway and inflammatory bowel disease: a two-sample Mendelian randomization.

Previous observational studies have suggested an association between tryptophan (TRP)-kynurenine (KYN) pathway and inflammatory bowel disease (IBD). However, whether there is a causal relationship among them remains unclear. Therefore, a two-sample Mendelian randomization (MR) study was conducted to explore the potential causal effects of crucial metabolites in TRP-KYN pathway on IBD and its subtypes. Using summary data from genome-wide association studies, a two-sample MR was employed to evaluate the genetic associations between TRP and KYN as exposures and IBD as an outcome. The inverse variance weighted method was used as the primary MR analysis, with MR-Egger, weighted mode, simple mode, and weighted median methods as complementary analyses. The odds ratios (OR) and 95% confidence intervals (CI) were determined for TRP-IBD (OR 0.739, 95% CI [0.697; 0.783]), TRP-UC (OR 0.875, 95% CI [0.814; 0.942]), TRP-CD (OR 0.685, 95% CI [0.613; 0.765]), KYN-IBD (OR 4.406, 95% CI [2.247; 8.641]), KYN-UC (OR 2.578, 95% CI [1.368; 4.858], and KYN-CD (OR 13.516, 95% CI [4.919; 37.134]). Collectively, the MR analysis demonstrated a significant protective association between TRP and IBD, whereas KYN was identified as a risk factor for IBD.

Single-cell RNA sequence presents atlas analysis for chondrocytes in the talus and reveals the potential mechanism in coping with mechanical stress.

Chondrocytes are indispensable for the function of cartilage because they provide the extracellular matrix. Therefore, gaining insight into the chondrocytes may be helpful in understanding cartilage function and pinpointing potential therapeutical targets for diseases. The talus is a part of the ankle joint, which serves as the major large joint that bears body weight. Compared with the distal tibial and fibula, the talus bears much more mechanical loading, which is a risk factor for osteoarthritis (OA). However, in most individuals, OA seems to be absent in the ankle, and the cartilage of the talus seems to function normally. This study applied single-cell RNA sequencing to demonstrate atlas for chondrocyte subsets in healthy talus cartilage obtained from five volunteers, and chondrocyte subsets were annotated. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses for each cell type, cell-cell interactions, and single-cell regulatory network inference and clustering for each cell type were conducted, and hub genes for each cell type were identified. Immunohistochemical staining was used to confirm the presence and distribution of each cell type. Two new chondrocyte subsets were annotated as MirCs and SpCs. The identified and speculated novel microenvironment may pose different directions in chondrocyte composition, development, and metabolism in the talus.

INHBB is a novel prognostic biomarker and correlated with immune infiltrates in gastric cancer.

Inhibin subunit beta B (INHBB) is a potential prognostic biomarker for a variety of cancers. However, its role in gastric cancer (GC) remains elusive. The differential expression data of INHBB in tumor and normal tissues were extracted from several databases and genetic alterations of INHBB were assessed by cBioPortal. Kaplan-Meier analysis was used to evaluate the survival rate of patients with GC with INHBB and association with clinical features in GC. Cox regression analysis was used to explore the prognostic value of clinical indicators and INHBB in GC, and a nomogram prognostic model was established. In addition, the predictive validity of the nomogram model was assessed by time-depended receiver operating characteristic (ROC) and calibration curves. Functional enrichment analyses were conducted to functionally annotate INHBB. Notably, we found that the quantitative assessment of immune cell subpopulation infiltration correlated with INHBB expression. INHBB expression is upregulated in GC and is correlated with several clinical features including prognostic indicators and a histological type. Genetic alterations were observed in INHBB, its DNA methylation level was negatively correlated with INHBB expression. High INHBB expression is associated with a poor prognosis and is an independent risk factor for prognosis in GC, along with age and residual tumor. The nomogram model showed a good prediction ability and was validated by time-depended ROC and calibration curves. Functional enrichment analysis indicated that INHBB-associated genes were enriched in tumor microenvironment Gene Ontology (GO) terms and were correlated with tumor-associated pathways. INHBB has a regulatory function in immune cell infiltration, especially macrophage infiltration in GC. Specifically, patients with GC with high INHBB expression and high macrophage infiltration have a worse prognosis. INHBB expression was negatively correlated with the expression of chemokines/chemokine receptors and plays a regulatory role in immunoinhibitor/immunostimulator-involved pathways. INHBB is a potential prognostic biomarker for GC and may drive the abnormal activity of critical cancer-associated pathways, potentially contributing to immune cell infiltration to promote GC development.

D-galacturonic acid ameliorates the intestinal mucosal permeability and inflammation of functional dyspepsia in rats.

BACKGROUND: Functional dyspepsia (FD) is a gastrointestinal disease caused by imbalanced gastrointestinal function. Traditional treatments are deemed to be limited, and new therapeutic drugs are required. New study suggested that duodenal low-grade inflammation and increased intestinal permeability play an important role in the pathogenesis of FD. Previous studies have shown that polysaccharides containing D-galacturonic acid (GA) could modulate intestinal immune activity in vitro and in animal models. However, the ability of GA monomer to improve intestinal mucosal permeability and inflammation in FD has not been clearly elucidated. METHODS: A FD rat model was established using iodoacetamide (IA). FD Rats were administrated different doses of GA. Subsequently, the body weight and behavioral sensitivity of the rats were measured and evaluated; the permeability of the intestinal barrier was measured by determining D-lactose, lactulose/mannitol ratio (LMR), and permeability-related genes [desmocollin-2 (DSC2), TJP1, and OCLN] in FD rats. Also, inflammatory cells [cluster of differentiation (CD)3+ cells and mast cells] were assessed by immunohistochemistry, and the levels of immune-related factors, such as the Toll-like receptor-nuclear factor kappa B (TLR/NF-κB) pathway, were monitored by reverse transcription quantitative polymerase chain reaction (RT-qPCR) or western blot assays. RESULTS: Our results suggested that GA could markedly increase the body weight and attenuate the behavioral sensitivity of FD rats. Moreover, GA also has an obvious ameliorating effect on the intestinal mucosal permeability and inflammatory response of FD rats. Furthermore, we found that GA could markedly downregulate TLR2, TLR4, and NF-κB in FD rats. CONCLUSIONS: These findings indicate that GA could significantly attenuate the intestinal mucosal permeability and inflammation FD rats. The effect of GA was partially mediated by the TLR/NF-κB signaling pathway.

A case report of a post-polypectomy syndrome with severe sepsis and organ dysfunction.

Post-polypectomy syndrome (PPS) results from electrocoagulation injury to the bowel wall that induces a transmural burn and localized peritonitis. It has a good prognosis; however, there are exceptions when complications are observed. We here report a case of a 50-year-old man who developed lumbosacral pain and high fever with chills four days after colonoscopy, during which polypectomy was performed by endoscopic mucosal resection (EMR) and argon plasma coagulation (APC). Both the plain abdominal film and abdominal CT scan showed no free air, and lumbar CT showed no apparent lesions, which satisfied the diagnosis of PPS. However, the patient was in a critical condition as he developed septic shock caused by bacteremia. Following active treatment, the patient's condition rapidly improved. Therefore, we suggest that clinicians should consider the severity of PPS with sepsis and colon transmural burn. Patients with a diagnosis of PPS should be admitted to the hospital for observation and treatment to avoid adverse consequences.

Low expression of A-kinase anchor protein 5 predicts poor prognosis in non-mucin producing stomach adenocarcinoma based on TCGA data.

BACKGROUND: In the past, there were not a lot of studies on how A-kinase anchor protein 5 (AKAP5) involving in the pathogenesis and prognosis of non-mucin producing stomach adenocarcinoma (NMSA). Therefore, we studied the relationship between AKAP5 and the prognosis of NMSA and its possible mechanisms using publicly available data from The Cancer Genome Atlas (TCGA). METHODS: RNA high-throughput sequencing and clinicopathologic data of NMSA were downloaded from the TCGA. Clinical pathologic features associated with AKAP5 expression were analyzed using the chi-square and Fisher exact tests. The relationship between the overall survival (OS) and AKAP5 expression was analyzed by the Kaplan-Meier method and the Cox regression analysis. GSEA analysis was performed using the TCGA dataset. RESULTS: Our results indicated that the AKAP5 expression was increased in NMSA (all tumor vs. adjacent mucosa). Also, histologic grade, clinical stage, N classification, and survival status were significantly correlated with AKAP5 expression. Kaplan-Meier curves showed that low AKAP5 expression was associated with a poor OS among the NMSA patients (P=5.003e-05), and in the clinical stage III and IV (P=4.646e-05), TNM stage T3 (P=0.016), T4 (P=0.001), N2 (P=0.012), N3 (P=0.003), M0 (P=3.911e-05), and histological grade G3 (P=1.658e-04) subgroups. Cox regression analysis showed that reduced AKAP5 expression in NMSA is associated with age (HR =1.03, P=0.007), stage (HR =1.84 for stage I, II vs. stage III, IV, P=0.002) and M classification (HR =1.8 for M0 vs. M1, P=0.010). Gene sets related to cholesterol homeostasis, glycolysis, estrogen response late, adipogenesis, estrogen response early, notch signaling, and peroxisome were differentially enriched with the low AKAP5 expression phenotype. CONCLUSIONS: Low expression of AKAP5 may be a potential molecular marker for predicting poor prognosis of NMSA. Besides, cholesterol homeostasis, glycolysis, estrogen response, adipogenesis, notch signaling, and peroxisome may be the key pathways regulated by AKAP5 in NMSA. It also suggested that AKAP5 might potentially have biological functions in the development of stomach adenocarcinoma.

The landscape of somatic mutation in sporadic Chinese colorectal cancer.

Colorectal cancer is the fifth prevalent cancer in China. Nevertheless, a large-scale characterization of Chinese colorectal cancer mutation spectrum has not been carried out. In this study, we have performed whole exome-sequencing analysis of 98 patients' tumor samples with matched pairs of normal colon tissues using Illumina and Complete Genomics high-throughput sequencing platforms. Canonical CRC somatic gene mutations with high prevalence (>10%) have been verified, including TP53, APC, KRAS, SMAD4, FBXW7 and PIK3CA. PEG3 is identified as a novel frequently mutated gene (10.6%). APC and Wnt signaling exhibit significantly lower mutation frequencies than those in TCGA data. Analysis with clinical characteristics indicates that APC gene and Wnt signaling display lower mutation rate in lymph node positive cancer than negative ones, which are not observed in TCGA data. APC gene and Wnt signaling are considered as the key molecule and pathway for colorectal cancer initiation, and these findings greatly undermine their importance in tumor progression for Chinese patients. Taken together, the application of next-generation sequencing has led to the determination of novel somatic mutations and alternative disease mechanisms in colorectal cancer progression, which may be useful for understanding disease mechanism and personalizing treatment for Chinese patients.