Effect of silencing connective tissue growth factor on rat liver fibrosis and the accumulation of extracellular matrix / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the anti-fibrogenesis property of intraportal vein injection of small interfering RNA targeting connective tissue growth factor (CTGF) in a rat model of liver fibrosis and its effect on the accumulation of extracellular matrix (ECM).</p><p><b>METHODS</b>Thirty male rats were randomly divided into five groups. Some rats received CCl4 subcutaneously every three days for 6 consecutive weeks, and in the meantime they also received either siRNA targeting CTGF (preventive group), saline (model group) or siRNA (siRNA control group) by intraportal vein injections. Other rats received CCl4 by subcutaneous injection for 2 weeks, followed by CCl4 and CTGF siRNA intraportal vein injection for 4 more weeks (as treatment group). The expressions of CTGF and type I and III collagen genes were detected by means of reverse transcription-polymerase chain reaction (RT-PCR) and/or Western blot respectively. Hepatic histology was evaluated by HE and Sirius red stained sections. The collagen staining areas were measured quantitatively using a computer-aided manipulator with slight modifications. Serum procollagen type III and hyaluronic acid were determined by radioimmunoassay.</p><p><b>RESULTS</b>Six weeks after CCl4 injection, prominent upregulation of gene expressions of CTGF, type I and III collagen, and laminin in saline or siRNA-treated rat livers were observed. The expressions of CTGF at mRNA and protein level and type I and III collagen at mRNA level were markedly reduced in rats with CTGF siRNA treated for four or six weeks. Expressions of CTGF at mRNA and protein levels decreased by 76%+/-8%, 80%+/-3% (F = 68.630) and 95%+/-2%, 93%+/-3% (F = 21.234, P < 0.01); type I and III collagen and laminin at mRNA levels decreased by 74%+/-8%, 78%+/-8%, 31%+/-7% and 57%+/-6%, 59%+/-10%, 43%+/-9% (F = 24.219, 16.315, 9.716, P < 0.01) compared with rats in the model group at 72 h. The CTGF siRNA treatment markedly reduced serum levels of procollagen type III and hyaluronic acid and the degrees of liver fibrosis.</p><p><b>CONCLUSION</b>Intraportal vein siRNA injection targeting CTGF could significantly inhibit CTGF gene expression in rats, thereby attenuating liver fibrosis by reducing ECM accumulation.</p>

Effects of silencing connective tissue growth factor on rat transforming growth factor beta/Smads signal / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the effects of small interfering RNA targeting connective tissue growth factor (CTGF) on rat transforming growth factor beta (TGF beta)/Smads signal pathway.</p><p><b>METHODS</b>Chemically synthetic siRNA targeting CTGF was transfected into HSC T6 and then they were injected into rat livers through their intraportal veins. At the same time these rats also received CCl4 subcutaneously every three days for 6 consecutive weeks. Untreated HSC T6 or/and rats with random siRNA treatment served as controls. Total RNA or/and protein in HSC T6 and rat hepatic tissues were extracted. The expressions of CTGF and TGF beta 1, Smad2, 3 and 7 genes were detected by reverse transcription-polymerase chain reaction (RT-PCR) and/or Western blot.</p><p><b>RESULTS</b>CTGF siRNA significantly reduced the expression of CTGF protein in HSC T6. At 48 h after CTGF siRNA treatment, the down-regulation of CTGF protein was the most significant, up to 94%+/-4% (t=46.196, P less than 0.01), but the expressions of TGF beta 1, Smad2, 3 and 7 mRNA showed no differences in HSC T6 compared with the blank controls. Six weeks after CCl4 injections, prominent up-regulations were observed in the gene expressions of CTGF and TGF beta 1 in saline control or siRNA-treated rat livers. Administering CTGF siRNA for six weeks markedly attenuated the induction of CTGF and TGF beta 1 genes; the expressions of CTGF and TGF beta 1 protein decreased by 95%+/-2% (F=21.234, P less than 0.01) and 74%+/-8% (F=13.464, P less than 0.05), respectively, whereas Smad2, 7 protein expressions were not affected.</p><p><b>CONCLUSION</b>Silencing the CTGF gene can suppress the TGF beta /Smads signal pathway in rat livers.</p>

Risk factors of irritable bowel syndrome in adolescents in China / 中华儿科杂志

<p><b>OBJECTIVE</b>To explore the risk factors for irritable bowel syndrome (IBS) among school adolescents in China.</p><p><b>METHOD</b>A stratified, randomized study by cluster sampling was conducted, which recruited 51,956 students from high and primary schools in Chinese cities. All students were requested to fill in a questionnaire.</p><p><b>RESULT</b>(1) Factors including class (odds ratio 1.12), excessive intake of pepper (odds ratio 1.17), fried (odds ratio 1.08) and starch-based foods (odds ratio 1.06), gastrointestinal tract infection (odds ratio 2.66), abuse of analgesic (odds ratio 1.49), inheritance (odds ratio 1.83), fatigue (odds ratio 1.32) and repression (odds ratio 1.45) were significantly associated with the presence of IBS (P < 0.05). High protein food (odds ratio 0.90) was a protective factor.</p><p><b>CONCLUSION</b>Different food intake, gastrointestinal tract infection, abuse of analgesic, inheritance and psychological factors might be related to development of IBS in the students of the cities involved in this study.</p>

COX-2 expression in the H. pylori infected gastric mucosal epithelia and its significance / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study COX-2 expression in H. pylori infected gastric mucosal epithelia and its significance in the carcinogenesis of the stomach.</p><p><b>METHODS</b>Rapid urease test and histological examination with basic magnenta staining were used to assess the status of H. pylori infection in the stomach. COX-2 was detected immunohistochemically.</p><p><b>RESULTS</b>COX-2 immunostaining was positive in 1 out of 12 cases with H. pylori-negative gastric mucosa and also in 1 out of 10 cases with H. pylori-positive gastric mucosa without macroscopic alterations, while COX-2 expression was found to be positive in 5 out of 9 cases with H. pylori related superficial gastritis with mucosal erosions. COX-2 expression was detected in 5 out of 10 cases with H. pylori-positive mild atrophic gastritis, 8 out of 10 cases with H. pylori-positive moderate-severe atrophic gastritis and intestinal metaplasia, and 6 out of 8 cases with H. pylori-positive moderate-severe dysplasia. COX-2 expression was positive in 22 out of 32 cases of gastric cancer.</p><p><b>CONCLUSION</b>H. pylori may induce COX-2 expression of gastric mucosal epithelia in chronic superficial gastritis, which is related to the development of mucosal injury. According to gastric mucosal carcinogenesis pattern up-regulation of COX-2 expression is associated with gastric mucosal carcinogenesis, and involved in the early development of premalignant lesions.</p>

Relationship between somatostatin receptors and activation of hepatic stellate cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Somafostatin receptors (SSTRs) have been suggested to involve in mediating the effect of somatostatin on hepatic stellate cells (HSCs) in an activation-dependent way. We, therefore, try to investigate the relationship between expression of SSTRs and activation of rat HSCs.</p><p><b>METHODS</b>HSCs were isolated from rats by in situ perfusion and single-step density gradient centrifugation. SSTR1-5 mRNA levels in the differentiated first passage HSCs were detected by means of a reverse transcription polymerase chain reaction. On the other hand, hepatic fibrosis was induced in adult male Sprague-Dawley rats by carbon tetrachloride intoxication, and the expression of SSTR1-5 in normal as well as fibrotic livers was measured by immunohistochemical staining.</p><p><b>RESULTS</b>SSTR mRNA and SSTR could not be found in freshly isolated rat HSCs or normal rat liver. However, SSTR1-3 mRNA appeared as HSCs became wholly activated, and could also be identified on the membrane of activated HSCs in the perisinusoid space, fibrous septa, etc.</p><p><b>CONCLUSION</b>The expression of SSTR1-3 in the rat HSC is closely related to its activation. This may reflect one of the main negative regulation mechanisms in the course of HSC activation.</p>

Therapeutic effects of octreotide on hepatofibrosis-induced with carbon tetrachloride in rats / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To investigate the therapeutic effects and mechanism of octreotide on experimental hepatic fibrosis in rats.</p><p><b>METHODS</b>Hepatofibrotic rats models were established with carbon tetrachloride. All the experimental rats were divided into four groups: normal control group, pre-and post-treatment model group, and octreotide-treated group in which the rats were injected subcutaneously with octreotide at the dose of 50ng/100g, twice daily, for thirty days. Serum levels of hyaluronic acid (HA), laminin (LN) and pro-collagen type III peptide (PCIII) were detected by radioimmunoassay. Hepatic fibrosis scoring grade was assessed through Van-Gieson staining and observed under light microscope. Protein expression levels of alpha-smooth muscle actin (alpha-SMA) and transforming growth factor beta1 (TGFbeta1) were determined with immunohistochemical staining method. Messenger RNA (mRNA) levels of collagen type I and PCIII were detected by reverse transcription polymerase chain reaction.</p><p><b>RESULTS</b>Serum levels of HA (ng/L), LN (microg/L) and PCIII (ng/L) in pre- and post-treatment model groups were higher than those in normal control group (121.8+/-9.5 and 110.3+/-13.4 vs. 33.1+/-3.7, 85.7+/-12.1 and 78.2+/-7.9 vs. 37.1+/-6.3, 35.9+/-3.5 and 33.7+/-2.6 vs. 15.6+/-2.8, respectively, t > or = 9.41, P<0.05), and there was no significant difference between the two model groups. Concentrations of HA (55.8ng/L+/-7.2ng/L), LN (43.1microg/L+/-3.4microg/L) and PCIII (27.8ng/L+/-3.4ng/L) decreased significantly in octreotide-treated group, compared with those in model groups (t >or=2.76, P<0.05). With histological analysis, fibrotic scoring grade in octreotide-treated group was obviously ameliorated, compared with that in model groups (chi2 > or = 3.97, P<0.05). Imaging analysis revealed that alpha-SMA and TGFbeta1 immunohistological staining areas were markedly shrinked in octreotide-treated group (t > or = 2.47, P < 0.05). In two model groups, PCIII and type I mRNA levels significantly up-regulated as compared with those in normal group (t > or = 9.27, P<0.001), and they were inhibited by octreotide markedly (t > or = 2.47, P<0.05).</p><p><b>CONCLUSIONS</b>Octreotide can inhibit hepatic stellate cells transforming into myofibroblasts, down-regulate TGFbeta1, collagen type I and PCIII transcriptions, so that it has therapeutic effects on experimental hepatic fibrosis.</p>