LncRNA XIST promotes mitochondrial dysfunction of hepatocytes to aggravate hepatic fibrogenesis via miR-539-3p/ADAMTS5 axis.

A previous study indicated that long non-coding RNA X-inactive-specific transcript (XIST) promoted ethanol-induced HSCs autophagy and activation. Considering the critical role of HSC activation in hepatic fibrosis, the aim of the present study was to reveal the exact role of XIST in liver fibrosis and its underlying mechanism. The expression of XIST in the liver from CCL4-induced mice and control mice as well as human fibrotic liver tissue and healthy liver tissue was examined. The mitochondrial reactive oxygen species (mtROS), mitochondrial membrane potential (MMP), and mitochondrial morphology were measured to assess the mitochondrial damage. The relationship between XIST and miR-539-3p as well as between miR-539-3p and ADAMTS5 was verified by a dual-luciferase reporter assay. The expression levels of HSCs activation markers were examined by Western blot. The results showed that the XIST was upregulated in fibrotic liver tissue, and overexpression of XIST induced mitochondrial dysfunction in hepatocytes. miR-539-3p directly targeted XIST, and ADAMTS5 mRNA was a downstream target of miR-539-3p. Knockdown of miR-539-3p led to an increased mitochondrial damage in hepatocytes in terms of reduced mitochondrial length, decreased MMP, and increased ROS production. However, the depletion of ADAMTS5 reversed the regulatory effect of XIST on mitochondrial damage in hepatocytes and the activation of HSCs. Our study revealed the critical role of the XIST/miR-539-3p/ADAMTS5 axis in regulating mitochondrial damage in hepatocytes and the activation of HSCs. This study may provide a potential therapeutic strategy for the treatment of liver fibrosis.

Protopine alleviates lipopolysaccharide-triggered intestinal epithelial cell injury through retarding the NLRP3 and NF-κB signaling pathways to reduce inflammation and oxidative stress.

BACKGROUND: Inflammatory bowel disease (IBD) is a common chronic intestinal disease. Protopine isolated from different plants has been investigated to understand its special functions on varied diseases. However, the regulatory effects of protopine on the progression of IBD remain unclear. Our study is aimed to explore the effects of protopine on the progression of IBD and its underlying regulatory mechanism of action. METHODS: The cell viability was assessed through MTT colorimetric assay. The protein expressions of genes were examined by Western blot analysis. The cell apoptosis and reactive oxygen species level were measured using flow cytometry. The levels of inflammation and oxidative stress-related proteins were tested through enzyme-linked-immunosorbent serologic assay. The intracellular Ca2+ concentration and mitochondrial membrane potential were measured through immunofluorescence assay. RESULTS: First, different concentrations of lipopolysaccharide (LPS) were treated with NCM460 cells to establish IBD cell model, and 5-µg/mL LPS was chosen for followed experiments. In this study, we discovered that protopine relieved the LPS-induced inhibited intestinal epithelial cell viability and enhanced cell apoptosis. Moreover, protopine attenuated LPS-stimulated inflammation activation and oxidative stress. Further experiments illustrated that the increased intracellular Ca2+ concentration and decreased mitochondrial membrane potential stimulated by LPS were reversed by protopine treatment. Finally, through Western blot analysis, it was demonstrated that protopine retarded the activated NLR family pyrin domain containing 3 (NLRP3) and nuclear factor kappa B (NF-κB) signaling pathways mediated by LPS. CONCLUSION: Protopine alleviated LPS-triggered intestinal epithelial cell injury by inhibiting NLRP3 and NF-κB signaling pathways to reduce inflammation and oxidative stress. This discovery may provide a useful drug for treating IBD.

Betulinic acid triggers apoptosis and inhibits migration and invasion of gastric cancer cells by impairing EMT progress.

Gastric cancer (GC) is one of the most prevalent types of malignancies. Betulinic acid (BA) is a natural pentacyclic triterpene with a lupine structure. However, to the best of our knowledge, there is no research study on the anti-tumour and anti-metastasis effect of BA on GC. In this study, we assessed the anti-cancer effect of BA on human GC cells in vitro and in vivo. We first investigated the cytotoxicity and anti-proliferation effect of BA on GC cells of SNU-16 and NCI-N87. The results indicated that BA had significant cytotoxic and inhibitory effects on GC cells in a dose- and time-dependent manner. To further study the cytotoxic action of BA on GC cells, we assessed the apoptotic induction effect of BA on SNU-16 cells and found that BA distinctly induced apoptosis in SNU-16 cells. In addition, BA inhibited the migratory and invasive abilities of SNU-16 cells. Western-blot analysis revealed that BA suppressed the migration and invasion of GC cells by impairing epithelial-mesenchymal transition progression. Furthermore, in vivo experiments showed that BA could delay tumour growth and inhibit pulmonary metastasis, which is consistent with the results of in vitro studies. Overall, we evaluated the anti-cancer effect of BA on human GC cells in vivo and in vitro, and the present study provides new evidence on the use of BA as a potential anti-cancer drug for GC treatment. SIGNIFICANCE OF THE STUDY: BA significantly suppressed proliferation and triggered apoptosis in GC cells. Additionally, BA remarkably inhibited migration and invasion of GC cells by impairing the epithelial-mesenchymal transition signalling pathway. It is worth noting that BA drastically retarded tumour growth in the xenograft mouse model of GC. Our results indicated that BA can be considered a candidate drug for GC therapy.

Knockdown of ZEB2-AS1 inhibits cell invasion and induces apoptosis in colorectal cancer.

PURPOSE: To uncover the potential function of long non-coding RNA (lncRNA) ZEB2-AS1 in the progression of colorectal cancer (CRC), and its underlying mechanism. METHODS: Relative level of ZEB2-AS1 in CRC tissues and matched normal ones was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Correlation between ZEB2-AS1 level and survival of CRC patients was analyzed by Kaplan-Meier method. Regulatory effects of ZEB2-AS1 on cellular behaviors of CRC cells were evaluated. The interactions between ZEB2-AS1 with LSD1 and EZH2 were explored by RNA immunoprecipitation (RIP) assay. 5-Ethynyl-2'- deoxyuridine (EdU) assay was performed to elucidate the roles of ZEB2-AS1, LSD1 and EZH2 on the proliferative ability of CRC cells. Finally, Spearman's correlation analysis was performed to analyze the relationship between ZEB2-AS1 level and expressions of proliferation- and invasion-related genes. RESULTS: ZEB2-AS1 was upregulated in CRC tissues relative to matched controls. Its level remained higher in CRC patients with ≥6 cm in tumor size, nodal metastasis and stage III-IV. CRC patients with low-level ZEB2-AS1 presented worse survival compared with those with high-level ZEB2-AS1. QRT-PCR data showed higher abundance of ZEB2-AS1 in CRC cell lines than colonic epithelial cell line. Knockdown of ZEB2-AS1 attenuated the proliferative, migratory and invasive abilities, but induced apoptosis of DLD1 and SW620 cells. RIP assay demonstrated the interaction between ZEB2-AS1 and LSD1, EZH2. Moreover, EdU assay revealed that transfection of sh-ZEB2-AS1 attenuated the proliferative ability, which was further reduced after co-transfection of sh-LSD1 or sh-EZH2. Finally, correlation analysis showed that mRNA level of ZEB2-AS1 was positively correlated to those of LSD1, EZH2, MMP9, MMP12 and KRAS, but negatively correlated to KLF2. CONCLUSIONS: LncRNA ZEB2-AS1 is upregulated in CRC. It accelerates CRC cells to proliferate via interacting with EZH2 and LSD1, thus promoting the progression of CRC.

MiR-218 regulates epithelial-mesenchymal transition and angiogenesis in colorectal cancer via targeting CTGF.

BACKGROUND: Endothelial-to-mesenchymal transition (EMT) and angiogenesis play important roles in colorectal cancer (CRC) development. Connective tissue growth factor (CTGF) has been reported to promote several kinds of cancer progression and miR-218 has been identified as a tumor suppressor miRNA. However, little is known about the function of miR-218 in CRC. Here we investigated the effects of miR-218 on EMT and angiogenesis process in CRC cells. As well, the relation between miR-218 and CTGF was identified. The mechanism of miR-218's function was illustrated. METHODS: CRC cell lines were transfected with miR-218 mimics. Proliferation, migration and angiogenesis were identified by MTT assay, Transwell assay, colony formation assay and tube formation assay. Protein and mRNA expression levels of associated genes were measured by Western blotting and RT-PCR. Dual luciferase assay was used to determine the relation of miR-218 and CTGF. RESULTS: miR-218 was down-regulated in CRC cell lines and over expression of miR-218 could significantly inhibit EMT and angiogenesis. CTGF was a direct target of miR-218. Up regulation of CTGF level after miR-218 transfection could sufficiently rescue the suppression effects on EMT and angiogenesis. CONCLUSION: miR-218 directly targets CTGF and inhibits its expression, leading to suppression on EMT and angiogenesis of CRC cells. miR-218 might be used as potential therapeutic strategy for CRC treatment.

Baicalin inhibits PDGF-BB-induced hepatic stellate cell proliferation, apoptosis, invasion, migration and activation via the miR-3595/ACSL4 axis.

Hepatic fibrosis is a physiological response to liver injury that includes a range of cell types. The pathogenesis of hepatic fibrosis currently focuses on hepatic stellate cell (HSC) activation into muscle fiber cells and fibroblasts. Baicalin is a flavone glycoside. It is the glucuronide of baicalein, which is extracted from the dried roots of Scutellaria baicalensis Georgi. Previous work focused on the anti­viral, ­inflammatory and ­tumor properties of baicalin. However, the potential anti­fibrotic effects and mechanisms of baicalin are not known. The present study demonstrated that baicalin influenced the activation, proliferation, apoptosis, invasion and migration of platelet­derived growth factor­BB­induced activated HSC­T6 cells in a dose­dependent manner. To investigate the anti­fibrotic effect of baicalin, a one­color micro (mi)RNA array and reverse transcription­quantitative polymerase chain reaction analyses were used. Results demonstrated that baicalin increased the expression of the miRNA, miR­3595. In addition, the inhibition of miR­3595 substantially reversed the anti­fibrotic effect of baicalin. The present data also suggested that miR­3595 negatively regulates the long­chain­fatty­acid­CoA ligase 4 (ACSL4). Furthermore, ACSL4 acted in a baicalin­dependent manner to exhibit anti­fibrotic effects. Taken together, it was concluded that baicalin induces miR­3595 expression that modulates the expression levels of ACSL4. To the best of our knowledge, the present study is the first to demonstrate that baicalin induces overexpression of human miR­3595, and subsequently decreases the expression of ACSL4, resulting in an anti-fibrotic effect.

Low temperature 65Cu NMR spectroscopy of the Cu+ site in azurin.

(65)Cu central-transition NMR spectroscopy of the blue copper protein azurin in the reduced Cu(I) state, conducted at 18.8 T and 10 K, gave a strongly second order quadrupole perturbed spectrum, which yielded a (65)Cu quadrupole coupling constant of +/-71.2 +/- 1 MHz, corresponding to an electric field gradient of +/-1.49 atomic units at the copper site, and an asymmetry parameter of approximately 0.2. Quantum chemical calculations employing second order Møller-Plesset perturbation theory and large basis sets successfully reproduced these experimental results. Sensitivity and relaxation times were quite favorable, suggesting that NMR may be a useful probe of the electronic state of copper sites in proteins.