Gut microbiota metabolite TMAO promoted lipid deposition and fibrosis process via KRT17 in fatty liver cells in vitro.

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide but still lacks specific treatment modalities. The gut microbiota and its metabolites have been shown to be intimately involved in NAFLD development, participating in and regulating disease progression. Trimethylamine N-oxide (TMAO), a metabolite highly dependent on the gut microbiota, has been shown to play deleterious regulatory roles in cardiovascular disease, but the relationship between it and NAFLD lacks validation from basic experiments. This research applied TMAO intervention by constructing fatty liver cell models in vitro to observe its effect on fatty liver cells and potential key genes and performed siRNA interference on the gene to verify the action. The results showed that TMAO intervention promoted the appearance of more red-stained lipid droplets in Oil-red O staining results, increased triglyceride (TG) levels and increased mRNA levels of liver fibrosis-related genes, and also identified one of the key genes, keratin17 (KRT17) via transcriptomics. Following the reduction in its expression level, under the same treatment, there were decreased red-stained lipid droplets, decreased TG levels, decreased indicators of impaired liver function as well as decreased mRNA levels of liver fibrosis-related genes. In conclusion, the gut microbiota metabolite TMAO could promote lipid deposition and fibrosis process via the KRT17 gene in fatty liver cells in vitro.

Correction to: Identification of ALDH3A2 as a novel prognostic biomarker in gastric adenocarcinoma using integrated bioinformatics analysis.

An amendment to this paper has been published and can be accessed via the original article.

Identification of ALDH3A2 as a novel prognostic biomarker in gastric adenocarcinoma using integrated bioinformatics analysis.

BACKGROUND: Extensive research has revealed that genes play a pivotal role in tumor development and growth. However, the underlying involvement of gene expression in gastric carcinoma (GC) remains to be investigated further. METHODS: In this study, we identified overlapping differentially expressed genes (DEGs) by comparing tumor tissue with adjacent normal tissue using the Gene Expression Omnibus (GEO) and the Cancer Genome Atlas (TCGA) database. RESULTS: Our analysis identified 79 up-regulated and ten down-regulated genes. Functional enrichment analysis and prognosis analysis were conducted on the identified genes, and the fatty aldehyde dehydrogenase (FALDH) gene, ALDH3A2, was chosen for more detailed analysis. We performed Gene Set Enrichment Analysis (GSEA) and immunocorrelation analysis (infiltration, copy number alterations, and checkpoints) to elucidate the mechanisms of action of ALDH3A2 in depth. The immunohistochemical (IHC) result based on 140 paraffin-embedded human GC samples indicated that ALDH3A2 was over-expressed in low-grade GC cases and the OS of patients with low expression of ALDH3A2 was significantly shorter than those with high ALDH3A2 expression. In vitro results indicated that the expression of ALDH3A2 was negatively correlated with PDCD1, PDCD1LG2, and CTLA-4. CONCLUSION: We conclude that ALDH3A2 might be useful as a potential reference value for the relief and immunotherapy of GC, and also as an independent predictive marker for the prognosis of GC.

Knockdown of ghrelin-O-acyltransferase attenuates colitis through the modulation of inflammatory factors and tight junction proteins in the intestinal epithelium.

Ghrelin-O-acyltransferase (GOAT) is a membrane-bound enzyme that attaches eight-carbon octanoate to a serine residue in ghrelin and thereby acylates inactive ghrelin to produce active ghrelin. In this study, we investigated the function of GOAT in the intestinal mucosal barrier. The intestinal mucosal barrier prevents harmful substances such as bacteria and endotoxin from entering the other tissues, organs, and blood circulation through the intestinal mucosa. Here, we established 5% dextran sodium sulfate (DSS)-induced colitis in mice and found that the body weight and colon weight were significantly decreased in these mice. Furthermore, increased inflammation and apoptosis were observed in the tissues of DSS-induced colitis mice, with increased expression of tumor necrosis factor-α, interleukin-6, phosphorylation of nuclear factor kappa B-p65 (p-NF-κB-p65), and cleaved caspase-3, and decreased expression of tight junction (TJ) proteins such as zonula occluden-1 and occludin. The knockdown of GOAT significantly attenuated colitis-induced inflammation responses and apoptosis, while GOAT overexpression significantly enhanced the induction of colitis. These results suggest that knockdown of GOAT may attenuate colitis-induced inflammation, ulcers, and fecal occult blood by decreasing the intestinal mucosal permeability via the modulation of inflammatory factors and TJ proteins.

Clinical study of autofluorescence imaging combined with narrow band imaging in diagnosing early gastric cancer and precancerous lesions.

PURPOSE: To evaluate the diagnostic values of autofluorescence imaging (AFI) combined with narrow band imaging (NBI) in diagnosing early gastric cancer and precancerous lesions. METHODS: 140 patients were investigated for lesions such as gastric mucosal roughness, erosion, plaque, abnormal color, bump or pitting by conventional endoscopy. AFI endoscope was used for the observation, and the endoscopic diagnosis was performed according to the fluorescence forms under the endoscopic AFI mode, as well as the changes of gastric mucosal capillaries and gastric pits under the NBI mode. The corresponding lesions were also biopsied for pathological examination. RESULTS: 78 patients were diagnosed as gastritis (including superficial and atrophic gastritis), 45 as intestinal metaplasia, 6 as dysplasia, and 11 as early gastric cancer. The sensitivity and specificity of AFI-NBI combination were 88.89 and 91.58% in the diagnosis of intestinal metaplasia; 83.33 and 98.51% for dysplasia; and 90.91 and 99.22% for early gastric cancer. All of them were significantly higher than the simple fluorescence endoscopy. CONCLUSIONS: The AFI-NBI combination could improve the detection rate of early gastric cancer and precancerous lesions.

Diagnostic value of autofluorescence imaging combined with narrow band imaging in intraepithelial neoplasia of Barrett's esophagus.

PURPOSE: To evaluate the diagnostic values of Auto Fluorescence Imaging (AFI) combined with Narrow Band Imaging (NBI) in the diagnosis of the intraepithelial neoplasia of Barrett's esophagus (BE). METHODS: Seventy four suspicious BE intraepithelial lesions were assessed in 50 patients by AFI, who were further subjected to NBI mode to observe the changes of gastric mucosal capillaries and gastric pits. The corresponding lesions were biopsied for pathological examination. RESULTS: Among the 74 AFI-diagnosed cases of suspicious lesions, 44 (59.5%) were high-grade intraepithelial neoplasias (BEHGIN), while the remaining 30 cases (40.5%) were false-positive. The NBI-diagnostic results of these 44 BEHGIN lesions were as follows: 39 cases were confirmed and 5 were suspicious; among the 30 false-positive BEHGIN cases, NBI gave 7 false-positive cases. The false-positive rates decreased from 40.5% of AFI to 9.5% (7/74) of NBI-AFI (p<0.05). The positive predictive value of AFI in BEHGIN was 59.5% (44/74), while that of AFI-NBI combination was 84.8% (39/46; p<0.05). CONCLUSIONS: The AFI-NBI combination technology could significantly improve (p<0.05) the detection rate of BEHGIN.

Prophylactic treatment with Bacteroides uniformis and Bifidobacterium bifidum counteracts hepatic NK cell immune tolerance in nonalcoholic steatohepatitis induced by high fat diet.

Hepatic immunity is one of the driving forces for the development of nonalcoholic steatohepatitis (NASH), and targeting gut microbiota is believed to affect the hepatic immune constitution. Here, we aimed to investigate the hepatic immunological state in NASH, with a specific emphasis on natural killer (NK) cells. In addition, we aimed to identify the contributing species that target hepatic immunity to provide new directions and support the feasibility of immunotherapy for NASH. A possible NASH population was determined by combination of long-term severe fatty liver, metabolic disorders and increased serum CK18 to detect serum immune factors and gut microbiota. NASH was induced in mice fed a high-fat diet to verify the prophylactic effect of the functional species on the immunopathology and development of NASH. Hepatic immunologic state was examined, and the effector functions of NK cells were detected. Hepatic transcriptome, proteomic, and fecal metagenome were performed. We observed a statistical increase in serum IL-10 (p < 0.001) and non-statistical decrease in interferon-γ and IL-6 in NASH population, hinting at the possibility of immune tolerance. Fecal Bacteroides uniformis and Bifidobacterium bifidum were abundant in healthy population but depleted in NASH patients. In NASH mice, hepatic CD8+T cells, macrophages, and dendritic cells were increased (p < 0.01), and NK cells were inhibited, which were identified with decreased granzyme B (p < 0.05). Bacteroides uniformis and Bifidobacterium bifidum improved hepatic pathological and metabolic cues, increased hepatic NK cells and reduced macrophages (p < 0.05). Bacteroides uniformis also restored hepatic NK cell function, which was identified as increased CD107a (p < 0.05). Transcriptional and translational profiling revealed that the functional species might restore the function of hepatic NK cells through multiple pathways, such as reduction of inhibitory molecules in NK cells. Bacteroides uniformis and Bifidobacterium bifidum are novel prophylactics for NASH that restore the impaired function of hepatic NK cells.

MicroRNA-221-3p Plays an Oncogenic Role in Gastric Carcinoma by Inhibiting PTEN Expression.

Gastric carcinoma is one of the most common malignancies in men, and microRNA plays a critical role in regulating the signaling networks of gastric carcinoma tumorigenesis and metastasis. We first report the functional characteristics of miR-221-3p in gastric carcinoma. Quantification in gastric carcinoma cell lines and tumor samples reveals significantly increasing miR-221-3p expression. Moreover, a high level of miR-221-3p is correlated with a poor prognosis for gastric carcinoma patients. Ectopic miR-221-3p expression significantly promotes gastric carcinoma cell proliferation, invasion, and sphere formation, while silencing miR-221-3p significantly inhibits these abilities in gastric carcinoma cells. Tests in vivo showed that miR-221-3p significantly promotes tumor growth in xenograft mouse models. In this study, we reveal that miR-221-3p targets PTEN mRNA and downregulates PTEN, which is the possible mechanism of miR-221-3p-induced oncogenic properties. Collectively, we reveal a critical role for miR-221-3p in gastric carcinoma development and progression.