Publications (6)29.02 Total impact
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Article: Sorafenib treatment improves hepatopulmonary syndrome in rats with biliary cirrhosis.
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ABSTRACT: Hepatopulmonary syndrome (HPS) is characterized by oxygen desaturation in patients with chronic liver disease. The initiation of HPS comes from abnormal pulmonary vasodilatation and/or angiogenesis. In this study, we evaluated the anti-angiogenesis therapy using sorafenib in experimental HPS animals. HPS was induced by common bile duct ligation (CBDL) in rats. A 2-week 10 mg/kg/day treatment regimen of sorafenib or distilled-water (control) was initiated 2 weeks after operation. Hemodynamics, liver biochemistry, plasma vascular endothelial growth factor (VEGF) measurements and blood gas analysis of the CBDL rats were done. The liver of the CBDL rats were dissected for histopathology examination and the lung was examined by immunohistochemical staining, real-time PCR and Western analysis. In another two parallel groups, intrapulmonary shunts were determined. The alveolar-arterial oxygen gradient (AaPO2) and plasma VEGF levels were reduced after sorafenib treatment (sorafenib vs. control: AaPO2 7.2 ± 3.4 vs. 15.3 ± 4.2 mmHg; P=0.004; VEGF 45.3 ± 2.7 vs. 54.4 ± 7.7 pg/mL; P=0.021). Sorafenib attenuated the pulmonary VEGF mRNA and VEGF, VEGF receptor 2 (VEGFR-2), phospho-VEGFR-2 and Akt protein expressions. In addition, sorafenib significantly attenuated intrapulmonary angiogenesis and decreased the degree of intrapulmonary shunting by 33.7% (sorafenib vs. control: 11.2 ± 5.7 % vs. 16.9 ± 5.9 %; P = 0.003). Our findings suggest that sorafenib attenuates intrapulmonary shunts and decrease AaPO2 in the CBDL rats, implicating the improvement of HPS in this experimental animal model. The beneficial effect may be attributed to the reduction of intrapulmonary angiogenesis through inhibition of VEGF/VEGFR-2/Akt pathway.Clinical Science 10/2012; · 4.61 Impact Factor -
Article: Cannabinoid receptor 2 agonist ameliorates mesenteric angiogenesis and portosystemic collaterals in cirrhotic rats.
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ABSTRACT: Angiogenesis in liver cirrhosis leads to splanchnic hyperemia, increased portal inflow, and portosystemic collaterals formation, which may induce lethal complications, such as gastroesophageal variceal hemorrhage and hepatic encephalopathy. Cannabinoids (CBs) inhibit angiogenesis, but the relevant influences in cirrhosis are unknown. In this study, Spraque-Dawley rats received common bile duct ligation (BDL) to induce cirrhosis. BDL rats received vehicle, arachidonyl-2-chloroethylamide (cannabinoid receptor type 1 [CB(1) ] agonist), JWH-015 (cannabinoid receptor type 2 [CB(2) ] agonist), and AM630 (CB(2) antagonist) from days 35 to 42 days after BDL. On the 43rd day, hemodynamics, presence of CB receptors, severity of portosystemic shunting, mesenteric vascular density, vascular endothelial growth factor (VEGF), VEGFR-1, VEGFR-2, phospho-VEGFR-2, cyclooxygenase (COX)-1, COX-2, and endothelial nitric oxide synthase (eNOS) expressions as well as plasma VEGF levels were evaluated. Results showed that CB(1) and CB(2) receptors were present in left adrenal veins of sham rats, splenorenal shunts (the most prominent intra-abdominal shunts) of BDL rats, and mesentery of sham and BDL rats. CB(2) receptor was up-regulated in splenorenal shunts of BDL rats. Both acute and chronic JWH-015 treatment reduced portal pressure and superior mesenteric arterial blood flow. Compared with vehicle, JWH-015 significantly alleviated portosystemic shunting and mesenteric vascular density in BDL rats, but not in sham rats. The concomitant use of JWH-015 and AM630 abolished JWH-015 effects. JWH-133, another CB(2) agonist, mimicked the JWH-015 effects. JWH-015 decreased mesenteric COX-1, COX-2 messenger RNA expressions, and COX-1, COX-2, eNOS protein expressions. Furthermore, JWH-015 decreased intrahepatic angiogenesis and fibrosis. CONCLUSIONS: CB(2) agonist alleviates portal hypertension (PH), severity of portosystemic collaterals and mesenteric angiogenesis, intrahepatic angiogenesis, and fibrosis in cirrhotic rats. The mechanism is, at least partly, through COX and NOS down-regulation. CBs may be targeted in the control of PH and portosystemic collaterals.Hepatology 01/2012; 56(1):248-58. · 11.66 Impact Factor -
Article: Kinetics of cytokine expression in cirrhotic rats.
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ABSTRACT: Cytokines are involved in liver injury and cirrhosis and systemic and hepatic cytokine levels may help predict cirrhosis evolution. However, the relevant survey has not been performed. Male Sprague-Dawley rats (240-270 g) received either common bile duct ligation (BDL, animal model of cholestatic liver injury) or sham operation (control). Five rats were sacrificed and liver and serum were collected from each in weeks 1, 2, 4, 6, 8 and 10 after surgery. Hepatic expression of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) were analyzed by immunohistochemial staining. The corresponding serum levels were measured by ELISA. Compared to the corresponding sham groups, hepatic expression of these cytokines in BDL rats was significantly and progressively enhanced during cirrhosis development. However, serum IFN-γ levels of BDL rats did not change significantly. Serum TNF-α of BDL rats increased gradually and reached a peak in week 6. Serum TGF-β level was elevated up to week 8, whereas IL-10 level decreased progressively until week 6. Cirrhosis development in BDL rats is associated with progressively enhanced expression of hepatic pro-inflammatory and anti-inflammatory cytokines, which is not in accord with the corresponding serum concentration. The circulating cytokine concentration may not totally reflect the hepatic expression level throughout the development of cirrhosis.Journal of the Chinese Medical Association 09/2011; 74(9):385-93. · 0.79 Impact Factor -
Article: H1-A extracted from Cordyceps sinensis suppresses the proliferation of human mesangial cells and promotes apoptosis, probably by inhibiting the tyrosine phosphorylation of Bcl-2 and Bcl-XL.
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ABSTRACT: H1-A, a pure compound used in traditional Chinese medicine, is effective in the treatment of autoimmune disorders of MRL lpr/lpr mice. We have previously reported that after 8 weeks of oral therapy with H1-A, 40 microg/kg/day, MRL lpr/lpr mice demonstrated significantly less proteinuria, lower serum creatinine levels, and less renal mesangial proliferation than mice in an untreated group. To clarify the pharmacologic properties of H1-A, we studied its cellular and subcellular effects in cultured human mesangial cells. Our results show that H1-A inhibits cell proliferation and promotes the apoptosis of interleukin (IL)-1- and platelet-derived growth factor (PDGF)-BB-activated human mesangial cells in vitro. Uptake of tritiated thymidine was nearly totally suppressed by the addition of 12.5 micromol/L H1-A (counts per minute decreased from 3905 +/- 70 to 141 +/- 5). The population of S-phase cells decreased from 15.5% +/- 1.7% to 10.0% +/- 0.3%, and G0 + G1 phase cells increased from 68.8% +/- 0.07% to 74.6% +/- 0.05%. This suppression was not a result of cytotoxicity. Apoptosis of human mesangial cells was detectable after treatment with 12.5 or 25 micromol/L H1-A. Using immunoprecipitation and immunoblotting, we found that H1-A inhibits tyrosine phosphorylation of human mesangial proteins and that Bcl-2 and Bcl-XL were probably among these proteins. These findings suggest that H1-A modulates some subcellular signal-transduction pathways and changes the balance between proliferation and apoptosis of mesangial cells in vitro or in vivo. H1-A may be effective in the management of autoimmune disorders, and the modulation of the signal transduction proteins Bcl-2 and Bcl-XL may represent a target for future pharmacologic interventions.Journal of Laboratory and Clinical Medicine 02/2003; 141(1):74-83. · 2.62 Impact Factor -
Article: Interleukin-17 induces src/MAPK cascades activation in human renal epithelial cells.
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ABSTRACT: Interleukin-17 (IL-17) is a T cell derived pro-inflammatory cytokine exhibiting multiple biological activities in a variety of cells. In our previous study, we found that IL-17 expressed early on borderline change of renal allograft rejection by Banff classification both in rat renal allograft model and human renal specimens. Renal epithelial cells (RECs) are the important targets in renal allograft rejection. The purpose of this study was to explore the signalling pathways by which human interleukin-17 (hIL-17) contributes to renal allograft rejection by inducing IL-6, IL-8 and MCP-1 expression in human renal epithelial cells (hRECs). Using reverse transcriptase-polymerase chain reaction (RT-PCR), immunoprecipitation and western blot analysis, we report that the early signalling events triggered by the hIL-17 involved tyrosyl phosphorylation of proteins and increased the levels of IL-6, IL-8 and MCP-1 in a dose-dependent manner. Tyrosyl phosphorylation of proteins was induced by IL-17 in 1 min and peaked in 5 min. Further, IL-17 induced the phosphorylation of src kinase and mitogen-activated protein (MAP) kinase. Using a specific src kinase inhibitor, PP2, to treat the hRECs before hIL-17 stimulation, we found that PP2 not only inhibited the phosphorylation of src kinase but also inhibited IL-6, IL-8 and MCP-1 mRNA expression, in a dose-dependent manner. These findings provide the first evidence that the mechanism of IL-17 signalling involves src/MAPK cascades activation.Cytokine 09/2002; 19(4):159-74. · 3.02 Impact Factor -
Article: Evidence for the early involvement of interleukin 17 in human and experimental renal allograft rejection.
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ABSTRACT: Inflammatory processes can stimulate renal epithelial cells to release cytokines, chemoattractants and matrix proteins into the interstitium, thus contributing to interstitial injury during acute allograft rejection. To test the role of interleukin 17 (IL-17) in this process, cultured human renal epithelial cells (hRECs) were first established and treated with or without human IL-17 (hIL-17) for 2, 4, 8 and 10 h in vitro. Significant elevations of IL-6 and IL-8 levels were noted in the supernatants in a dose-dependent and time-dependent manner, as also for IL-6 mRNA expression. Secondly, using a rat acute allograft rejection model, the correlation between IL-17 expression and histopathological changes was serially studied. The results demonstrated that increased expression of IL-17 protein on infiltrating mononuclear cells (MNCs) was detectable on day 2. This corresponds to the borderline change of acute rejection according to the Banff classification, and it increased progressively to day 5. Serial study of IL-6, IL-8 and IL-17 mRNA expression of the renal allograft confirmed IL-17 mRNA expression in the allograft early on post-transplant day 2, whereas IL-6 and IL-8 expression started on day 3. Thirdly, IL-17 expression was observed in human renal allograft and urinary sediment. IL-17 protein expression was found in human subclinical (borderline) rejection renal allograft biopsy tissue and none in biopsy tissue not showing any evidence of rejection. There was also a 100% detectable rate of IL-17 mRNA expression in the MNCs of urinary sediment of patients with subclinical borderline rejection. These results demonstrate that hRECs exposed to IL-17 can produce inflammatory mediators with the potential to stimulate early alloimmune responses, which may also serve to give warning of acute renal allograft rejection.The Journal of Pathology 08/2002; 197(3):322-32. · 6.32 Impact Factor
Top co-authors
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Institutions
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2002–2012
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Taipei Veterans General Hospital
- • Department of Medicine
- • Department of Medical Research and Education
- • Department of Pediatrics
- • Surgery Division
Taipei, Taipei, Taiwan -
National Yang Ming University
- Institute of Microbiology and Immunology
Taipei, Taipei, Taiwan
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