Bacteroides fragilis, one of the potential next-generation probiotics, but its protective mechanism is not yet known. We aimed to characterize the anti-inflammatory effect of B. fragilisATCC25285 and to elucidate its mechanism through in vivo and in vitro experiments. An in vitro model of inflammation by induction of colonic cells with TNF-a, and co-cultured with B. fragilis to detect cell viability, apoptosis and invasive capacity. Furthermore, critical proteins of the TLR/NF-κB pathway and the inflammatory cytokines were measured. For animal trials, C57BL/6 J male mice were orally administered B. fragilis or PBS once daily for 21 days. Colitis was induced by drinking 2.5% DSS from days 0 to 7. The mice were weighed daily and rectal bleeding, stool condition and blood in the stool were recorded. We found that B. fragilis treatment alone was harmless and had no effect on cell viability or apoptosis. While predictably TNF-α decreased cell viability and increased apoptosis, B. fragilis attenuated this deterioration. The NF-κB pathway and inflammatory cytokines IL-6 and IL-1β activated by TNF-α were also blocked by B. fragilis. Notably, the metabolic supernatant of B. fragilis also has an anti-inflammatory effect. Animal studies showed that live B. fragilis rather than dead strain ameliorated DSS-induced colitis, as evidenced by weight loss, shortened colon length and enhanced barrier function. The colonic tissue levels of inflammatory cytokines (TNF-α, IL-1β, IL-6) were decreased and IL-10 was increased as a result of B. fragilis administration. In conclusion, B. fragilis ATCC25285 exhibited anti-inflammatory effects whether in vivo or in vitro, and it may be a potential probiotic agent for improving colitis.
7 July 2021 in Signal Transduction and Targeted Therapy
Complement factor B (CFB) serves a pivotal role in the alternative signaling pathway of the complement system and exerts a key role in the labelling of target particles, resulting from effective clearance of the target. The present study aimed to investigate the association between low expression levels of CFB and the clinical features and survival status of patients with lung adenocarcinoma (LUAD). Patient data were based on RNA‑sequencing and clinical data from The Cancer Genome Atlas database. All patients were divided into two groups based on the median expression of CFB. Kaplan‑Meier curve and univariate Cox regression analyses were used to investigate the association between CFB and survival status. Gene set enrichment analysis was used to examine the effects of CFB expression on signaling pathway impairment. Furthermore, reverse transcription‑quantitative PCR (RT‑qPCR) and western blotting were used to verify the relative expression levels of CFB in LUAD tissues. The data revealed that residual tumor classification, Karnofsky performance score and cancer stage were associated with overall survival, and that Karnofsky performance score and stage were associated with disease‑free survival. The results demonstrated that high expression levels of CFB were associated with increased patient overall and disease‑free survival according to both continuous and categorical models. The results of multivariate analysis identified that high expression levels of CFB were associated with increased overall and disease‑free survival according to both the continuous model [hazard ratio (HR), 0.48; 95% confidence interval (95% CI), 0.25‑0.93; P=0.029 for overall survival; HR, 0.29; 95% CI, 0.15‑0.59; P=0.001 for disease‑free survival] and the categorical model (HR, 0.46; 95% CI, 0.22‑0.93; P=0.031 for overall survival; HR, 0.25; 95% CI, 0.12‑0.55; P=0.001 for disease‑free survival) after adjusting for corresponding covariates (residual tumour classification, Karnofsky performance score and stage). Furthermore, the results of both RT‑qPCR and western blotting indicated that the relative mRNA and protein expression levels of CFB in lung tumor tissues were downregulated compared with those in adjacent non‑tumor tissues. Collectively, the present results suggested that CFB expression was an independent predictor of overall and disease‑free survival in patients with LUAD.
Lung cancer in Xuanwei (LCXW), China, is known throughout the world for its distinctive characteristics, but little is known about its pathogenesis. The purpose of this study was to screen potential novel “driver genes” in LCXW. Genome-wide DNA copy number alterations (CNAs) were detected by array-based comparative genomic hybridization and differentially expressed genes (DEGs) by gene expression microarrays in 8 paired LCXW and non-cancerous lung tissues. Candidate driver genes were screened by integrated analysis of CNAs and DEGs. The candidate genes were further validated by real-time quantitative polymerase chain reaction. Large numbers of CNAs and DEGs were detected, respectively. Some of the most frequently occurring CNAs included gains at 5p15.33-p15.32, 5p15.1-p14.3, and 5p14.3-p14.2 and losses at 11q24.3, 21q21.1, 21q22.12-q22.13, and 21q22.2. Integrated analysis of CNAs and DEGs identified 24 candidate genes with frequent copy number gains and concordant upregulation, which were considered potential oncogenes, including CREB3L4, TRIP13, and CCNE2. In addition, the analysis identified 19 candidate genes with a negative association between copy number change and expression change, considered potential tumor suppressor genes, including AHRR, NKD2, and KLF10. One of the most studied oncogenes, MYC, may not play a carcinogenic role in LCXW. This integrated analysis of CNAs and DEGs identified several potential novel LCXW-related genes, laying an important foundation for further research on the pathogenesis of LCXW and identification of novel biomarkers or therapeutic targets.
Evidence from multiple studies suggests metabolic abnormalities play an important role in lung cancer. Lung adenocarcinoma (LUAD) is the most common subtype of lung cancer. The present study aimed to explore differences in the global metabolic response between male and female patients in LUAD and to identify the metabolic genes associated with lung cancer susceptibility. Transcriptome and clinical LUAD data were acquired from The Cancer Genome Atlas (TCGA) database. Information on metabolic genes and metabolic subsystems were collected from the Recon3D human metabolic model. Two validation datasets (GSE68465 and GSE72094) were downloaded from the Gene Expression Omnibus (GEO) database. Differential expression analysis, gene set enrichment analysis and protein-protein interaction networks were used to identified key metabolic pathways and genes. Functional experiments were used to verify the effects of genes on proliferation, migration, and invasion in lung cancer cells in vitro. Samples of tumors and adjacent non-tumor tissue from both male and female patients exhibited distinct global patterns of gene expression. In addition, we found large differences in methionine and cysteine metabolism, pyruvate metabolism, cholesterol metabolism, nicotinamide adenine dinucleotide (NAD) metabolism, and nuclear transport between male and female LUAD patients. We identified 34 metabolic genes associated with lung cancer susceptibility in males and 15 in females. Most of the metabolic cancer-susceptibility genes had high prediction accuracy for lung cancer (AUC > 0.9). Furthermore, both bioinformatics analysis and experimental results showed that TAOK2 was down-regulated and ASAH1 was up-regulated in male tumor tissue and female tumor tissue in LUAD. Functional experiments showed that inhibiting ASAH1 suppressed the proliferation, migration, and invasion of lung cancer cells. Metabolic cancer-susceptibility genes may be used alone or in combination as diagnostic markers for LUAD. Further studies are required to elucidate the functions of these genes in LUAD.
22 August 2017 in Annals of Clinical Microbiology and Antimicrobials
In recent years, New Delhi metallo-beta-lactamases 1 (bla NDM-1) has been reported with increasing frequency and become prevalent. The present study was undertaken to investigate the epidemiological dissemination of the bla NDM-1 gene in Enterobacter cloacae isolates at a teaching hospital in Yunnan, China. Antimicrobial susceptibility testing was performed using VITEK 2 system and E test gradient strips. The presence of integrons and insertion sequence common region 1 were examined by PCR and sequencing. Clonal relatedness was assessed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. Conjugation experiments and Southern blot hybridization were performed to determine the transferability of plasmids. Ten E. cloacae isolates and their Escherichia coli transconjugants were exhibited similar resistant patterns to carbapenems, cephalosporins and penicillins. 8 (80%) of E. cloacae isolates carried class 1 integron and 1 (12.5%) carried class 2 integron. Integron variable regions harbored the genes which encoded resistance to aminoglycosides (aadA1, aadA2, aadA5, aadB, aac(6′)-Ib-cr), sulfamethoxazole/trimethoprim (dfrA17, dfrA12, dfrA15) and Streptozotocin (sat2). Six E. cloacae isolates belonged to ST74 and exhibited highly similar PFGE patterns. Each isolate shared an identical plasmid with ~33.3 kb size that carried the bla NDM-1 gene, except T3 strain, of which the bla NDM-1 gene was located on a ~50 kb plasmid. Our findings suggested that plasmid was able to contribute to the dissemination of bla NDM-1. Hence, more attention should be devoted to monitor the dissemination of the bla NDM-1 gene due to its horizontal transfer via plasmid. In addition, nosocomial surveillance system should actively monitor the potential endemic clone of ST74 to prevent their further spread.