Background and aims Defective autophagy has been proposed as an important event in a growing number of autoimmune and inflammatory diseases such as rheumatoid arthritis and lupus. However, the precise role of mechanistic target of rapamycin (mTOR)-dependent autophagy and its underlying regulatory mechanisms in the intestinal epithelium in response to inflammation and oxidative stress remain poorly understood. Methods The levels of p-mTOR, LC3B, p62 and autophagy in mice and LPS-treated cells were examined by immunoblotting, immunohistochemistry, confocal microscopy and transmission electron microscopy (TEM). We evaluated the expression of IL-1β, IL-8, TNF-α, MDA, SOD and T-AOC by quantitative real time-polymerase chain reaction (qRT-PCR) and commercially available kits after silencing of mTOR and ATG5. In vivo modulation of mTOR and autophagy was achieved by using AZD8055, rapamycin and 3-methyladenine. Finally, to verify the involvement of TLR4 signalling and the NF-κB pathway in cells and active ulcerative colitis (UC) patients, immunofluorescence, qRT-PCR, immunoblotting and TEM were performed to determine TLR4 signalling relevance to autophagy and inflammation. Results The mTOR-dependent autophagic flux impairment in a murine model of colitis, human intestinal epithelial cells and active UC patients is probably regulated by TLR4-MyD88-MAPK signalling and the NF-κB pathway. Silencing mTOR remarkably attenuated, whereas inhibiting ATG5 aggravated, LPS-induced inflammation and oxidative injury. Pharmacological administration of mTOR inhibitors and autophagy stimulators markedly ameliorated experimental colitis and oxidative stress in vivo. Conclusions Our findings not only shed light on the regulatory mechanism of mTOR-dependent autophagy, but also provided potential therapeutic targets for intestinal inflammatory diseases such as refractory inflammatory bowel disease.
BackgroundGrowing evidence suggests that SALL4 plays a vital role in tumor progression and metastasis. However, the molecular mechanism of SALL4 promoting esophageal squamous cell carcinoma (ESCC) remains to be elucidated.MethodsThe gene and protein expression profiles- were examined by using quantitative real-time PCR, immunohistochemistry and western blotting. Small hairpin RNA was used to evaluate the role of SALL4 both in cell lines and in animal models. Cell proliferation, apoptosis and invasion were assessed by CCK8, flow cytometry and transwell-matrigel assays. Sphere formation assay was used for cancer stem cell derivation and characterization.ResultsOur study showed that the transcription factor SALL4 was overexpressed in a majority of human ESCC tissues and closely correlated with a poor outcome. We established the lentiviral system using short hairpin RNA to knockdown SALL4 in TE7 and EC109 cells. Silencing of SALL4 inhibited the cell proliferation, induced apoptosis and the G1 phase arrest in cell cycle, decreased the ability of migration/invasion, clonogenicity and stemness in vitro. Besides, down-regulation of SALL4 enhanced the ESCC cells’ sensitivity to cisplatin. Xenograft tumor models showed that silencing of SALL4 decreased the ability to form tumors in vivo. Furthermore, our study demonstrated that SALL4 played a vital role in modulating the stemness of ESCC cells via Wnt/β-catenin signaling pathway and in epithelial-mesenchymal transition.ConclusionsOur results revealed that SALL4 might serve as a functional marker for ESCC cancer stem cell, a crucial marker for prognosis and an attractive candidate for target therapy of ESCC.
Left ventricular remodeling after acute myocardial infarction (AMI) is associated with adverse prognosis. It is becoming increasingly clear that circulating miRNAs could be promising biomarkers for various pathological processes in the heart, including myocardial infarction, myocardial remodeling and progression to heart failure. In the present study, a total of 359 consecutive patients were recruited. Plasma samples were collected on admission. Echocardiographic studies were performed during the admission and at six months follow-up after AMI. Remodeling was defined as an at least 10% increase from baseline in the left ventricular end-diastolic volume. Plasma miRNA levels were assessed for association with six months mortality or development of heart failure. Results showed that levels of plasma miR-208b and miR-34a were significantly higher in patients with remodeling than those without. Increased miRNA levels were strongly associated with increased risk of mortality or heart failure within six months for miR-208b (OR 17.91, 95% confidence interval = 2.07–98.81, p = 0.003), miR-34a (OR 4.18, 95% confidence interval = 1.36–12.83, p = 0.012) and combination of the two miRNAs (OR 18.73, 95% confidence interval = 1.96–101.23, p = 0.000). The two miRNA panels reclassified a significant proportion of patients with a net reclassification improvement of 11.7% (p = 0.025) and an integrated discrimination improvement of 7.7% (p = 0.002). These results demonstrated that circulating miR-208b and miR-34a could be useful biomarkers for predicting left ventricular remodeling after AMI, and the miRNA levels are associated with increased risk of mortality or heart failure.
Inflammatory bowel disease (IBD), which encompasses ulcerative colitis (UC) and Crohn's disease (CD), is a complicated, uncontrolled, and multifactorial disorder characterized by chronic, relapsing, or progressive inflammatory conditions that may involve the entire gastrointestinal tract. The protracted nature has imposed enormous economic burdens on patients with IBD, and the treatment is far from optimal due to the currently limited comprehension of IBD pathogenesis. In spite of the exact etiology still remaining an enigma, four identified components, including personal genetic susceptibility, external environment, internal gut microbiota, and the host immune response, are responsible for IBD pathogenesis, and compelling evidence has suggested that IBD may be triggered by aberrant and continuing immune responses to gut microbiota in genetically susceptibility individuals. The past decade has witnessed the flourishing of research on genetics, gut microbiota, and immunity in patients with IBD. Therefore, in this review, we will comprehensively exhibit a series of novel findings and update the major advances regarding these three fields. Undoubtedly, these novel findings have opened a new horizon and shed bright light on the causality research of IBD.
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