Chlorogenic acid alleviates autophagy and insulin resistance by suppressing JNK pathway in a rat model of nonalcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver diseases around the world and commonly associated with insulin resistance and hyperlipidemia. Chlorogenic acid (CG) was reported to have insulinsensitizing activity and exert hypocholesterolemic and hypoglycemic effect. However, the involvement of CG in NAFLD remains far from being addressed. In this study, a high-fat diet-induced NAFLD rat model was used to investigate the biological roles and underlying mechanism of CG in NAFLD. The results showed that high-fat diet-fed rats exhibited an increase in body weight, glucose tolerance, liver injury, insulin resistance, as well as autophagy and C-Jun N-terminal kinase (JNK) pathway. Nevertheless, all these effects were alleviated by CG treatment. Moreover, angiotensin treatment in CG group activated the JNK pathway, and promoted autophagy, insulin resistance, and liver injury. In conclusion, our findings demonstrated that CG ameliorated liver injury and insulin resistance by suppressing autophagy via inactivation of JNK pathway in a rat model of NAFLD. Therefore, CG might be a potential application for the treatment of NAFLD.

Short-segment Barrett's esophagus and cardia intestinal metaplasia: A comparative analysis.

AIM: to investigate the endoscopy and histology of short-segment Barrett's esophagus (SSBE) and cardia intestinal metaplasia (CIM), and their correlation with Helicobacter pylori (H. pylori) gastritis and gastroesophageal reflux disease (GERD). METHODS: biopsy specimens were taken from 32 SSBE patients and 41 CIM patients with normal appearance of the esophagogastric junction. Eight biopsy specimens from the lower esophagus, cardia, and gastric antrum were stained with hematoxylin/eosin, Alcian blue/periodic acid-Schiff, Alcian blue/high iron diamine and Gimenez dye. Results were graded independently by one pathologist. RESULTS: the SSBE patients were younger than the CIM patients (P < 0.01). The incidence of dysplasia and incomplete intestinal metaplasia subtype was higher in SSBE patients than in CIM patients (P < 0.01). H. pylori infection was correlated with antral intestinal metaplasia (P < 0.05), but not with reflux symptomatic, endoscopic, or histological markers of GERD in CIM patients. SSBE was correlated with reflux symptomatic and endoscopic esophagitis (P < 0.01), but not with H. pylori infection and antral intestinal metaplasia. CONCLUSION: dysplasia risk is significantly greater in SSBE patients than in CIM patients. CIM is a manifestation of H. pylori-associated and multifocal atrophic gastritis, whereas SSBE may result from GERD.

[Porcine follistatin cDNA cloning and expression in Escherichia coli].

The total RNA was extracted from porcine ovary. Porcine Follistatin cDNA was cloned by RT-PCR. Complete porcine follistatin cDNA coding sequences are presented including 1038 bp of open reading frame. The purified porcine follistatin cDNA was inserted into pGEX-4T-3 vector to construct the prokaryotic fusion protein expression vector. The recombinant expression plasmid was transformed into BL21 (DE3) and expression was induced by IPTG. Protein products were detected by SDS-PAGE and confirmed by Western blotting analysis, which showed that the yield of the Follistatin cDNA was a 63kD protein expression vector. Follistatin protein was expressed in the form of glutathione-S-transferase (GST) fusion protein in E. coli.

[Expression of intestine-specific transcription factor CDX2 in different subtypes of intestinal metaplasia and gastric carcinoma].

BACKGROUND & OBJECTIVE: Intestinal metaplasia (IM) is thought as the precancerous lesion of gastric carcinoma, and CDX2 gene plays important roles in development and differentiation of intestinal epithelium, and maintenance of intestinal phenotype. Recent studies found that CDX2 were expressed aberrantly in IM of chronic atrophic gastritis (CAG) and some gastric carcinomas, which implied that CDX2 may play an important role in IM formation and gastric carcinogenesis. This study was to investigate the roles of CDX2 in the development and progression of IM and gastric carcinogenesis, and determine the correlation of IM to gastric carcinogenesis. METHODS: A tissue microarray containing 46 cases of CAG with IM, 40 cases of gastric carcinoma, and 32 cases of IM foci in paracancerous tissues was constructed. High iron diamine/alcian blue (HID/AB) and HE staining were used to classify IM and gastric carcinoma, and the expression of CDX2 protein and mRNA in different gastric lesions was assessed with immunohistochemistry and in situ hybridization, respectively. RESULTS: The proportion of type III IM was significantly higher in IM foci in paracancerous tissues than in CAG with IM (56.25% vs. 21.74%, P<0.01). The positive rates of CDX2 protein were 69.56% in IM foci in CAG, 53.13% in IM foci in paracancerous tissues, and 42.50% in gastric carcinomas, and the positive rates of CDX2 mRNA were 63.04%, 46.87%, and 35.00%, respectively. The positive rates were significantly lower in gastric cancer than in IM in CAG (P<0.01), but there was no significant difference between gastric cancer and IM foci in paracancerous tissues (P>0.05). The expression of CDX2 protein and mRNA was significantly higher in intestinal-type gastric cancer than in diffuse-type gastric cancer (54.55% vs. 27.78%, 45.45% vs. 22.22%, P<0.05). The expression of CDX2 protein was significantly lower in type III IM than in type I IM (46.42% vs. 79.31%, P<0.05). CONCLUSIONS: CDX2 may play important roles in the development and progression of IM and gastric carcinogenesis.

Gene expression in rats with Barrett's esophagus and esophageal adenocarcinoma induced by gastroduodenoesophageal reflux.

AIM: To study the different gene expression profiles in rats with Barrett's esophagus (BE) and esophageal adenocarcinoma (EA) induced by gastro-duodeno-esophageal reflux. METHODS: Esophagoduodenostomy was performed in 8-wk old Sprague-Dawley rats to induce gastro-duodeno-esophageal reflux, and a group of rats that received sham operation served as control. Esophageal epithelial pathological tissues were dissected and frozen in liquid nitrogen immediately. The expression profiles of 4096 genes in EA and BE tissues were compared to normal esophagus epithelium in normal control (NC) by cDNA microarray. RESULTS: Four hundred and forty-eight genes in BE were more than three times different from those in NC, including 312 upregulated and 136 downregulated genes. Three hundred and seventy-seven genes in EA were more than three times different from those in NC, including 255 upregulated and 142 downregulated genes. Compared to BE, there were 122 upregulated and 156 downregulated genes in EA. In the present study, the interested genes were those involved in carcinogenesis. Among them, the upregulated genes included cathepsin C, aminopeptidase M, arachidonic acid epoxygenase, tryptophan-2,3-dioxygenase, ubiquitin-conjugating enzyme, cyclic GMP-stimulated phosphodiesterase, tissue inhibitor of metalloproteinase-1, betaine-homocysteine methyltransferase, lysozyme, complement 4b binding protein, complement 9 protein, insulin-like growth factor binding protein, UDP-glucuronosyltransferase, tissue inhibitor of metalloproteinase-3, aldolase B, retinoid X receptor gamma, carboxylesterase and testicular cell adhesion molecule 1. The downregulated genes included glutathione synthetase, lecithin-cholesterol acyltransferase, p55CDC, heart fatty acid binding protein, cell adhesion regulator and endothelial cell selectin ligand. CONCLUSION: Esophageal epithelium exposed excessively to harmful ingredients of duodenal and gastric reflux may develop into BE and even EA gradually. The gene expression level is different between EA and BE, and may be related to the occurrence and progression of EA.

Gene expression in Barrett's esophagus and reflux esophagitis induced by gastroduodenoesophageal reflux in rats.

AIM: To investigate the difference of gene expression profiles between Barrett's esophagus and reflux esophagitis induced by gastroduodenoesophageal reflux in rats. METHODS: Eight-week-old Sprague-Dawley rats were treated esophagoduodenostomy to produce gastroduodenoesophageal reflux, and another group received sham operation as control. Esophageal epithelial tissues were dissected and frozen in liquid nitrogen immediately for pathology 40 wk after surgery. The expression profiles of 4 096 genes in reflux esophagitis and Barrett's esophagus tissues were compared with normal esophageal epithelium by cDNA microarray. RESULTS: Four hundred and forty-eight genes in Barrett's esophagus were more than three times different from those in normal esophageal epithelium, including 312 up-regulated and 136 down-regulated genes. Two hundred and thirty-two genes in RE were more than three times different from those in normal esophageal epithelium, 90 up-regulated and 142 down-regulated genes. Compared to reflux esophagitis, there were 214 up-regulated and 142 down-regulated genes in Barrett's esophagus. CONCLUSION: Esophageal epithelium exposed excessively to harmful ingredients of duodenal and gastric reflux can develop esophagitis and Barrett's esophagus gradually. The gene expression level is different between reflux esophagitis and Barrett's esophagus and the differentially expressed genes might be related to the occurrence and development of Barrett's esophagus and the promotion or progression in adenocarcinoma.

Distinction between short-segment Barrett's esophageal and cardiac intestinal metaplasia.

AIM: To investigate the roles of mucin histochemistry, cytokeratin 7/20 (CK7/20) immunoreactivity, clinical characteristics and endoscopy to distinguish short-segment Barrett's esophageal (SSBE) from cardiac intestinal metaplasia (CIM). METHODS: High iron diamine/Alcian blue (HID/AB) mucin-histochemical staining and immunohistochemical staining were used to classify intestinal metaplasia (IM) and to determine CK7/20 immunoreactivity pattern in SSBE and CIM, respectively, and these results were compared with endoscopical diagnosis and the positive rate of gastroesophageal reflux disease (GERD) symptoms and H pylori infection. Long-segment Barrett's esophageal and IM of gastric antrum were designed as control. RESULTS: The prevalence of type III IM was significantly higher in SSBE than in CIM (63.33% vs 23.08%, P< 0.005). The CK7/20 immunoreactivity in SSBE showed mainly Barrett's pattern (76.66%), and the GERD symptoms in most cases which showed Barrett's pattern were positive, whereas H pylori infection was negative. However, the CK7/20 immunoreactivity in CIM was gastric pattern preponderantly (61.54%), but there were 23.08% cases that showed Barrett's pattern. H pylori infection in all cases which showed gastric pattern was significantly higher than those which showed Barrett's pattern (63.83% vs 19.30%, P< 0.005), whereas the GERD symptoms in gastric pattern were significantly lower than that in Barrett's pattern (21.28% vs 85.96%, P< 0.005). CONCLUSION: Distinction of SSBE from CIM should not be based on a single method; however, the combination of clinical characteristics, histology, mucin histochemistry, CK7/20 immunoreactivity, and endoscopic biopsy should be applied. Type III IM, presence of GERD symptoms, and Barrett's CK7/20 immunoreactivity pattern may support the diagnosis of SSBE, whereas non-type III IM, positive H pylori infection, and gastric CK7/20 immunoreactivity pattern may imply CIM.

[Isolation and identification of reprogramming genes related to the development of the rabbit reconstructed embryos].

By the method of single preimplantation embryos differential display polymerase chain reaction (SPEDDRT-PCR), 25 reprogramming cDNA fragments were obtained from single 2-cell, 8-cell embryos and blastula. After cloning and sequencing, five of them were identified by reverse-Northern and characterized with stage-specific expression during reconstructed embryo development. This results will help to isolate full length reprogramming genes and study their function during embryonic development.

Analysis of gene expression in rabbit nuclear transfer embryos: Use of single-embryo mRNA differential display.

Lack of or abnormal expression of developmentally important genes is believed to hamper early development of the nuclear transfer (NT) embryo. To identify stage-specific genes in rabbit NT embryo development, mRNA differential display was used to compare the mRNA content of rabbit NT embryos at different developmental stages, from Metaphase II oocytes to 8-16-cell stage embryos. Thirty-four zygotic transcripts, which abruptly appeared at the 8-16-cell stage in rabbit NT embryos, were isolated; 11 of these were potential novel genes with no matches in the current databases. Of the remaining 23, 12 were matched with established sequence tags with functions uncharacterized and the other 11 were homologous to those in the European Molecular Biology Laboratory (EMBL) and GenBank databases. The differential expression of eight of the 34 amplicons were confirmed by reverse Northern blotting, and four positive clones were validated. Previous studies and present data indicated that these three genes were probably related to preimplantation rabbit embryo development.