The Role of Autophagy in Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is an idiopathic intestinal inflammatory disease, including ulcerative colitis (UC) and Crohn's disease (CD). The abnormality of inflammatory and immune responses in the intestine contributes to the pathogenesis and progression of IBD. Autophagy is a vital catabolic process in cells. Recent studies report that autophagy is highly involved in various kinds of diseases, especially inflammation-related diseases, such as IBD. In this review, the biological characteristics of autophagy and its role in IBD will be described and discussed based on recent literature. In addition, several therapies for IBD through modulating the inflammasome and intestinal microbiota taking advantage of autophagy regulation will be introduced. We aim to bring new insight in the exploration of mechanisms for IBD and development of novel therapeutic strategies against IBD.

MicroRNA-155-enhanced autophagy in human gastric epithelial cell in response to Helicobacter pylori.

BACKGROUND/AIM: MicroRNAs (miRNAs) are a class of small noncoding RNAs acting as posttranscriptional gene expression regulators in many physiological and pathological conditions. MiR-155 is one kind of miRNAs that plays an important role in causing various diseases. However, the precise molecular mechanism of the ectopic expression of miR-155 in Helicobacter pylori infection remains poorly understood. Autophagy has recently been identified as an effective way to control the intracellular bacterium survival. In the present study, we demonstrate a novel role of miR-155 in regulating the autophagy-mediated anti-H. pylori response. PATIENTS AND METHODS: Totally 86 H. pylori-positive patients together with 10 H. pylori-negative, healthy control subjects were included in the study. Correlation between immunohistochemical grades and miR-155 expression were determined. Molecular mechanism of miR-155 on regulation of autophagy and elimination of intracellular H. pylori were determined using the GES-1 cell model. RESULTS: We found that overexpression of miR-155 by transfecting miR-155 mimics could significantly decrease the survival of intracellular H. pylori, and this process was through induction of autophagy. Furthermore, there was a significant correlation between miR-155 and immunohistochemical grades in H. pylori-positive patients, and miR-155 expression were decreased in the intestinal metaplasia group. CONCLUSIONS: The results have indicated that the miR-155 expression level plays a key role in immunity response against H. pylori and this might provide potential targets for the future treatment of H. pylori-related diseases.

[An analysis of amino acid metabolic profile and its clinical significance in ulcerative colitis].

OBJECTIVE: To determine the relationship between serum amino acid composition and pathogenesis of ulcerative colitis ( UC) , so as to explore some new biomarkers for early diagnosis and treatment. METHODS: This study was conducted in the 309 Hospital of Chinese People's Liberation Army between October 2012 and November 2013. Forty-four UC patients and 52 healthy controls were enrolled and the serum samples were collected. Using high performance liquid chromatography-mass spectrometry technology (HPLC-MS/MS) stable isotope internal standard method, we detected serum amino acid metabolic profiling in the two groups. RESULTS: Compared with the control group, the serum levels of glutamic acid, glutamine, methionine, tryptophan and histidine in UC group were significantly lower [(59.20 +/- 21.93) mol/L vs. (88.14 +/- 34.85) micromol/L; (2200.51 +/- 648.03) [mol/L vs. (2 664.91 +/- 1034.74) micromol/L;(268.69 +/- 211.64) micromol/L vs. (431.48 +/- 298.00) micromol/L; (68.83 +/- 32.33) [mol/L vs. (89.96 +/- 29.29) micromol/L; (101.88 +/- 32.01) micromol/L vs. (115.10 +/- 17.84) micromol/L respectively, all P < 0.05 ]. However, the serum levels of asparagine and isoleucine in UC group were significantly higher than the control group [(195.14 +/- 122.14) micromol/L vs. (140.49 +/- 34.91) micromol/L; (94.61 +/- 29.76) micromol/L vs. (80.99 +/- 19.73) [micromol/L respectively; both P < 0.05]. CONCLUSION: The amino acid metabolic profiling in UC patients is different from that in healthy controls, which suggests that there might be a certain relationship between amino acid composition and pathogenesis of UC. Some amino acids would be tested as potential biomarkers in patients with UC.

Comparative proteomics analysis of serum proteins in ulcerative colitis patients.

In the present study, we investigated the differentially expressed proteins associated with ulcerative colitis (UC) using proteomic methods. Two-dimensional electrophoresis (2-DE) technology was performed to separate the total proteins of ulcerative tissues from those of the normal tissues of UC patients. PDQuest software was applied to analyze the obtained 2-DE images. Candidate protein spots between the two groups were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and bioinformatics analysis. The well resolution and reproducible 2-DE patterns of UC and normal tissues were established. Of the 12 differentially expressed proteins, 9 were successfully identified, of which 6 proteins were up-regulated including apolipoprotein C-III, haptoglobin, receptor tyrosine kinase, aldehyde reductase, pericentriolar material 1, and heat shock factor protein 2, and 3 were down-regulated including keratin, filamin A-interacting protein 1, and tropomyosin 3. These identified proteins were related to hormonal modulation, immune response, oxidative stress, and signal conduction. The 2-DE protein expression profile of the UC tissues displays an obvious difference from that of the normal controls. Various proteins may be involved in the occurrence of UC.

The role of calcyclin gene in the proliferation and migration of gastric cancer cells.

The aim of this study was to investigate the influence of calcyclin on the growth, proliferation, apoptosis, invasion and cell cycle of gastric cancer cell lines in order to elucidate the role that calcyclin plays in gastric adenocarcinoma. Calcyclin cDNA was subcloned into a constitutive vector pcDNA3.1 followed by liposome-mediated transfection in the MKN45 gastric cancer cell line. Stable transfectants were selected and appraised. Specific inhibition of calcyclin was achieved using a vector-based siRNA system by transfection into the SGC7901 gastric cancer cell line. The apoptosis and cell cycle of these clones were analyzed by flow cytometry. Growth and proliferation were analyzed by cell growth curves and a colony-formation assay, respectively. The invasion of these clones was analyzed by a cell migration assay. MKN-calcyclin grew faster compared to MKN45 and MKN-PC (MKN45 transfected with pcDNA3.1 vector). SGC-SR1,2 grew slower compared to SGC7901 and SGC-SS1,2 (SGC7901 transfected with scrambled control duplexes). Cell cycle analysis showed that proportions of MKN-calcyclin and SGC-SR1,2 cells in G0/G1 and G2/M were significantly different compared to those of their control groups, respectively (P<0.05). The apoptosis rate of MKN-calcyclin was significantly lower compared to those of control groups (P<0.05). Results of colony-formation assay showed that the colony formation rate of MKN-calcyclin was higher compared to those of control groups, otherwise the rates of SGC-SR1,2 were lower compared to those of their control groups (P<0.05). The results of the cell migration assay showed that the migration rate of MKN-calcyclin was significant lower compared to those of its control groups, conversely, the migration rates of SGC-SR1,2 were significantly higher than those of their control groups (P<0.05). In conclusion, calcyclin can promote the growth and proliferation of gastric cancer cells and knockdown of calcyclin can restrain the growth and proliferation of gastric cancer cells. It can help tumor cells maintain the malignant phenotype. However, it can depress the ability of invasion of gastric cancer cells, thus restraining the metastasis of gastric cancer.

The impact of C-MYC gene expression on gastric cancer cell.

The upregulation or mutation of C-MYC has been observed in gastric, colon, breast, and lung tumors and in Burkitt's lymphoma. However, little is known about the role C-MYC plays in gastric adenocarcinoma. In the present study, we intended to investigate the influence of C-MYC on the growth, proliferation, apoptosis, invasion, and cell cycle of the gastric cancer cell line SGC7901 and the gastric cell line HFE145. C-MYC cDNA was subcloned into a constitutive vector PCDNA3.1 followed by transfection in normal gastric cell line HFE145 by using liposome. Then stable transfectants were selected and appraised. Specific inhibition of C-MYC was achieved using a vector-based siRNA system which was transfected in gastric cancer cell line SGC7901. The apoptosis and cell cycles of these clones were analyzed by using flow cytometric assay. The growth and proliferation were analyzed by cell growth curves and colony-forming assay, respectively. The invasion of these clones was analyzed by using cell migration assay. The C-MYC stable expression clones (HFE-Myc) and C-MYC RNAi cells (SGC-MR) were detected and compared with their control groups, respectively. HFE-Myc grew faster than HFE145 and HFE-PC (HFE145 transfected with PCDNA3.1 vector). SGC-MR1, 2 grew slower than SGC7901 and SGC-MS1, 2 (SGC7901 transfected with scrambled control duplexes). The cell counts of HFE-Myc in the third, fourth, fifth, sixth, and seventh days were significantly more than those of control groups (P < 0.05). Those of SGC-MR1, 2 in the fourth, fifth, sixth, and seventh days were significantly fewer than those of control groups (P < 0.05). Cell cycle analysis showed that proportions of HFE-Myc and SGC-MR cells in G0-G1 and G2-M were different significantly with their control groups, respectively (P < 0.05). The apoptosis rate of HFE-Myc was significantly higher than those of control groups (P < 0.05). Results of colony-forming assay showed that the colony formation rate of HFE-Myc was higher than those of control groups; otherwise, the rate of SGC-MR was lower than those of their control groups (P < 0.05). The results of cell migration assay showed that there were no significant differences between experimental groups and control groups (P > 0.05). In conclusion, C-MYC can promote the growth and proliferation of normal gastric cells, and knockdown of C-MYC can restrain the growth and proliferation of gastric cancer cells. It can induce cell apoptosis and help tumor cell maintain malignant phenotype. But it can have not a detectable influence on the ability of invasion of gastric cancer cells.

Proteomic analysis reveals molecular biological details in varioliform gastritis without Helicobacter pylori infection.

AIM: To investigate and elucidate the molecular mechanism underlying varioliform gastritis for early detection, prevention and intervention of gastric cancer. METHODS: A combination of two-dimensional gel electrophoresis and mass spectrometry was used to detect the differentially expressed proteins between varioliform gastritis and matched normal mucosa. The selected proteins were confirmed by Western blotting and reverse transcription polymerase chain reaction (RT-PCR) in additional samples and the function of some proteins in varioliform gastritis was analyzed by bio-method preliminarily. RESULTS: We identified 21 differentially expressed proteins in varioliform gastritis, and compared them with matched normal mucosa. Eleven proteins were upregulated and ten downregulated in varioliform gastritis when compared with the same proteins in individual-matched normal gastric mucosa. These proteins are related to metabolism, oxidation, cytoskeleton, apoptosis, signal transduction and other aspects of cells. Two novel proteins, thioredoxin domain-containing protein 5 (TXNDC5) upregulated in varioliform gastritis, and neuropolypeptide h3 [phosphatidylethanolamine-binding protein 1 (PEBP1)] downregulated in varioliform gastritis, were further investigated. Their expressions were validated by Western blotting and RT-PCR in 12 cases of varioliform gastritis which was matched with normal mucosa. The expression level of PEBP1 in varioliform gastritis was significantly lower (P < 0.05) while that of TXNDC5 was significantly higher than that in matched normal gastric mucosa (P < 0.05). CONCLUSION: There are some changes of protein expression in varioliform gastritis. Downregulation of PEBP1 and upregulation of TXNDC5 are involved in the development of varioliform gastritis.

The influence of TXNDC5 gene on gastric cancer cell.

BACKGROUND: TXNDC5 (thioredoxin domain containing 5) is over-expressed in tumors of the cervix, uterus, stomach and lung. However, not much is known about the functional roles of TXNDC5 gene in gastric adenocarcinoma. In the present study, we intend to investigate the effects of TXNDC5 on the growth, proliferation, apoptosis, invasion and cell cycle of the gastric cancer cell line MKN45 and normal gastric cell line HFE145. METHODS: TXNDC5 cDNA was inserted into a constitutive vector pcDNA3.1 followed by transfection into normal gastric cell line HFE145 using liposome. Then, stable transfectants were selected and appraised. Specific silencing of TXNDC5 gene was achieved using a vector-based short interference RNAs (siRNA) system in gastric cancer cell line MKN45. The growth and proliferation were analyzed by cell growth curves and colony-forming assay, respectively. The apoptosis and cell cycles of these clones were analyzed using flow cytometry. The invasion of these cells was analyzed by cell migration assay. The TXNDC5 stable expression cell lines (HFE-TXNDC5) and TXNDC5 RNAi cell lines (MKN-SR1,2) were detected and compared with their control groups, respectively. RESULTS: HFE-TXNDC5 grew faster than HFE145 and HFE-PC(HFE145 transfected with pcDNA3.1 vector). MKN-SR1 grew slower than MKN45 and MKN-SS1,2 (MKN45 transfected with scrambled control duplexes). The cell counts of HFE-TXNDC5 in the fifth, sixth and seventh days were significantly higher than those of control groups (P < 0.05). The cell counts of MKN-SR1 in the fifth, sixth and seventh days were significantly lower than those of control groups (P < 0.05). Cell cycle analysis showed that there were significant differences in proportions of G0-G1 and G2-M phase between HFE-TXNDC5, MKN-SR1 cells and their control groups, respectively (P < 0.05). The apoptosis rate of HFE-TXNDC5 was significantly lower than that of control groups (P < 0.05). The results of colony-forming assay showed that the colony formation rate of HFE-TXNDC5 was higher than those of control groups, otherwise the rate of MKN-SR1 were lower than those of their control groups (P < 0.05). The results of cell migration assay showed that the migration rate of HFE-TXNDC5 were significantly higher than that of its control group. Conversely, the migration rate of MKN-SR1 was significantly lower than that of its control group (P < 0.05). CONCLUSION: TXNDC5 can promote the growth and proliferation of gastric cells. Silencing of TXNDC5 can restrain the growth and proliferation of gastric cancer cells. The gene can enhance the capability of invasion of gastric cancer cells. In some respects, TXNDC5 could be thought as a tumor-enhancing gene in gastric cancer.

Study of glue extrusion after endoscopic N-butyl-2-cyanoacrylate injection on gastric variceal bleeding.

AIM: To investigate glue extrusion after endoscopic N-butyl-2-cyanoacrylate injection on gastric variceal bleeding and to evaluate the long-term efficacy and safety of this therapy. METHODS: A total of 148 cirrhotic patients in our hospital with esophagogastric variceal bleeding (EGVB) were included in this study. N-butyl-2-cyanoacrylate was mixed with lipiodol in a 1:1 ratio and injected as a bolus of 1-3 mL according to variceal size. Patients underwent endoscopic follow-up the next week, fourth week, second month, fourth month, and seventh month after injection and then every 6 mo to determine the cast shape. An abdominal X-ray film and ultrasound or computed tomographic scan were also carried out in order to evaluate the time of variceal disappearance and complete extrusion of the cast. The average follow-up time was 13.1 mo. RESULTS: The instantaneous hemostatic rate was 96.2%. Early re-bleeding after injection in 9 cases (6.2%) was estimated from rejection of adhesive. Late re-bleeding occurred in 12 patients (8.1%) at 2-18 mo. The glue cast was extruded into the lumen within one month in 86.1% of patients and eliminated within one year. Light erosion was seen at the injection position and mucosa edema in the second week. The glue casts were extruded in 18 patients (12.1%) after one week and in 64 patients (42.8%) after two weeks. All kinds of glue clumping shapes and colors on endoscopic examination were observed in 127 patients (86.1%) within one month, including punctiform, globular, pillar and variform. Forty one patients (27.9%) had glue extrusion after 3 mo and 28 patients (28.9%) after six months. The extrusion time was not related to the injection volume of histoacryl. Obliteration was seen in 70.2% (104 cases) endoscopically. The main complication was re-bleeding resulting from extrusion. The prognosis of the patients depended on the severity of the underlying liver disease. CONCLUSION: Endoscopic injection of cyanoacrylate is highly effective for gastric varices bleeding. The glue clump shape is correlated with anatomic structure of vessels. The time of extrusion was not related to dosage of the glue.