Key Laboratory of Transplant Engineering and Immunology of Health Ministry of China

China

Key Laboratory of Transplant Engineering and Immunology of Health Ministry of China

China

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Long D.,Key Laboratory of Transplant Engineering and Immunology of Health Ministry of China | Lu J.,Key Laboratory of Transplant Engineering and Immunology of Health Ministry of China | Luo L.,Key Laboratory of Transplant Engineering and Immunology of Health Ministry of China | Guo Y.,Key Laboratory of Transplant Engineering and Immunology of Health Ministry of China | And 8 more authors.
Journal of Surgical Research | Year: 2012

Background: Of solid organ transplantations, pancreas transplantation is associated with the highest incidence of pancreatic fibrosis in the early post-transplantation period. Activated pancreatic stellate cells (PSCs) are the main source of pancreatic fibrosis. Octreotide is widely used as a prophylactic for postoperative complications in pancreas transplant recipients. Recent studies have shown that it can inhibit liver fibrosis. This study investigated the effect of octreotide in pancreas graft fibrosis in rats. Materials and methods: Isolated PSCs from Sprague Dawley rats were co-cultured with different doses of octreotide (1.25, 2.5, 5, 10, 20, and 40 ng/mL). PSC proliferation was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide at 48, 72, and 96 h. The α-smooth muscle actin (α-SMA) and collagen I expressions of PSCs were detected by immunohistochemistry and reverse-transcriptase polymerase chain reaction. Rat heterotopic pancreaticoduodenal transplantation was performed with and without octreotide treatment (0.01 mg/kg). Pancreas grafts were harvested at postoperative d 1, 3, 5, and 7. Hematoxylin-eosin staining, Masson's trichrome staining, and immunohistochemical staining for α-SMA, collagen I, and tumor growth factor-β1 (TGF-β1) were performed. Results: Octreotide at a concentration of >20 ng/mL significantly inhibited PSC activation and proliferation in vitro. Inflammatory infiltration was reduced in the octreotide group in vivo, and the expression levels of α-SMA, collagen I, and TGF-β1 were also lower, with statistic significant difference or not. Masson's trichrome staining showed a decrease in collagen deposition with octreotide treatment. Conclusions: Octreotide effectively inhibits PSC activation and proliferation in vitro, but has a limited inhibitory effect on the development of pancreas graft fibrosis. © 2012 Elsevier Inc. All rights reserved.


Luo L.,Key Laboratory of Transplant Engineering and Immunology of Health Ministry of China | Luo L.,University of Sichuan | Lu J.,Key Laboratory of Transplant Engineering and Immunology of Health Ministry of China | Wei L.,Key Laboratory of Transplant Engineering and Immunology of Health Ministry of China | And 8 more authors.
BMC Cell Biology | Year: 2010

Background: Human major histocompatibility complex class I-related chain A (MICA) plays a dual role in adaptive and innate immune responses. Increasing evidence demonstrates that MICA is closely correlated with acute and chronic kidney allograft rejection. Therefore, understanding the activation mechanisms of MICA is important in kidney transplantation. We previously demonstrated that ischemia/reperfusion injury (IRI) could up-regulate MICA expression on mouse kidney allografts. Since hypoxia-inducible factor-1 (HIF-1) is the master regulator of cellular adaptive responses to hypoxia during IRI, here we investigate whether HIF-1 could up-regulate MICA expression and its influence on NK cell cytotoxicity.Results: We find that HIF-1alpha plays an important role in up-regulating MICA expression, inducing IFNgamma secretion and NK cell cytotoxicity during hypoxia/reoxygenation. First, we generated a HIF-1alphaDELTAODD-expressing adenovirus to stably and functionally express HIF-1alpha in human renal proximal tubular epithelial (HK-2) cells under normoxia conditions. HIF-1alpha over-expression in HK-2 cells induces MICA expression and enhances NK cell cytotoxic activity towards cells that express HIF-1alpha. Second, we used a hypoxia/reoxygenation cell model to simulate IRI in vitro and found that the suppression of HIF-1alpha by RNAi induces down-regulation of MICA expression and inhibits NK cytotoxicity. In antibody blocking experiments, an anti-MICA mAb was able to down-regulate NK cell cytotoxic activity towards HK-2 cells that over-expressed HIF-1alpha. Moreover, when NK cells were co-cultured with the HK-2 cells expressing MICA, which was up-regulated by over-expression of HIF-1alpha, there was a significant increase in the secretion of IFNgamma. In the presence of the blocking MICA mAb, IFNgamma secretion was significantly decreased.Conclusions: These results demonstrate that hypoxia/reoxygenation-promoted MICA expression on HK-2 cells is through a HIF-1 pathway. The increased IFNgamma secretion and enhanced NK cell cytotoxicity was mainly due to the surface expression of MICA induced by over-expression of HIF-1alpha. This study enhances our understanding of MICA activation mechanisms during kidney transplantation and provides insights into how IRI can influence transplant outcome. Moreover, these findings might be also important for developing strategies to reduce the effect of MICA in kidney transplant outcomes in the future. © 2010 Luo et al; licensee BioMed Central Ltd.


PubMed | Key Laboratory of Transplant Engineering and Immunology of Health Ministry of China
Type: Journal Article | Journal: The Journal of surgical research | Year: 2012

Of solid organ transplantations, pancreas transplantation is associated with the highest incidence of pancreatic fibrosis in the early post-transplantation period. Activated pancreatic stellate cells (PSCs) are the main source of pancreatic fibrosis. Octreotide is widely used as a prophylactic for postoperative complications in pancreas transplant recipients. Recent studies have shown that it can inhibit liver fibrosis. This study investigated the effect of octreotide in pancreas graft fibrosis in rats.Isolated PSCs from Sprague Dawley rats were co-cultured with different doses of octreotide (1.25, 2.5, 5, 10, 20, and 40 ng/mL). PSC proliferation was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide at 48, 72, and 96 h. The -smooth muscle actin (-SMA) and collagen I expressions of PSCs were detected by immunohistochemistry and reverse-transcriptase polymerase chain reaction. Rat heterotopic pancreaticoduodenal transplantation was performed with and without octreotide treatment (0.01 mg/kg). Pancreas grafts were harvested at postoperative d 1, 3, 5, and 7. Hematoxylin-eosin staining, Massons trichrome staining, and immunohistochemical staining for -SMA, collagen I, and tumor growth factor-1 (TGF-1) were performed.Octreotide at a concentration of >20 ng/mL significantly inhibited PSC activation and proliferation in vitro. Inflammatory infiltration was reduced in the octreotide group in vivo, and the expression levels of -SMA, collagen I, and TGF-1 were also lower, with statistic significant difference or not. Massons trichrome staining showed a decrease in collagen deposition with octreotide treatment.Octreotide effectively inhibits PSC activation and proliferation in vitro, but has a limited inhibitory effect on the development of pancreas graft fibrosis.


PubMed | Key Laboratory of Transplant Engineering and Immunology of Health Ministry of China
Type: | Journal: BMC cell biology | Year: 2010

Human major histocompatibility complex class I-related chain A (MICA) plays a dual role in adaptive and innate immune responses. Increasing evidence demonstrates that MICA is closely correlated with acute and chronic kidney allograft rejection. Therefore, understanding the activation mechanisms of MICA is important in kidney transplantation. We previously demonstrated that ischemia/reperfusion injury (IRI) could up-regulate MICA expression on mouse kidney allografts. Since hypoxia-inducible factor-1 (HIF-1) is the master regulator of cellular adaptive responses to hypoxia during IRI, here we investigate whether HIF-1 could up-regulate MICA expression and its influence on NK cell cytotoxicity.We find that HIF-1alpha plays an important role in up-regulating MICA expression, inducing IFNgamma secretion and NK cell cytotoxicity during hypoxia/reoxygenation. First, we generated a HIF-1alphaDELTAODD-expressing adenovirus to stably and functionally express HIF-1alpha in human renal proximal tubular epithelial (HK-2) cells under normoxia conditions. HIF-1alpha over-expression in HK-2 cells induces MICA expression and enhances NK cell cytotoxic activity towards cells that express HIF-1alpha. Second, we used a hypoxia/reoxygenation cell model to simulate IRI in vitro and found that the suppression of HIF-1alpha by RNAi induces down-regulation of MICA expression and inhibits NK cytotoxicity. In antibody blocking experiments, an anti-MICA mAb was able to down-regulate NK cell cytotoxic activity towards HK-2 cells that over-expressed HIF-1alpha. Moreover, when NK cells were co-cultured with the HK-2 cells expressing MICA, which was up-regulated by over-expression of HIF-1alpha, there was a significant increase in the secretion of IFNgamma. In the presence of the blocking MICA mAb, IFNgamma secretion was significantly decreased.These results demonstrate that hypoxia/reoxygenation-promoted MICA expression on HK-2 cells is through a HIF-1 pathway. The increased IFNgamma secretion and enhanced NK cell cytotoxicity was mainly due to the surface expression of MICA induced by over-expression of HIF-1alpha. This study enhances our understanding of MICA activation mechanisms during kidney transplantation and provides insights into how IRI can influence transplant outcome. Moreover, these findings might be also important for developing strategies to reduce the effect of MICA in kidney transplant outcomes in the future.

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