Inducible nitric oxide synthase expression in chronic viral hepatitis. Evidence for a virus-induced gene upregulation.
نویسندگان
چکیده
Increased nitric oxide (NO) production may contribute to the pathological changes featuring in some inflammatory diseases, but the role of NO in chronic viral hepatitis is still unknown. We compared the inducible NO synthase (NOS2) expression in the liver of patients with chronic viral hepatitis with that of both nonviral liver disease and histologically normal liver. NOS2 expression was assessed by immunohistochemical and in situ hybridization studies of liver biopsy sections. An intense hepatocellular NOS2 reactivity was detected in chronic viral hepatitis, whereas it was weakly or not observed in nonviral liver disease or normal liver, respectively. In addition, we determined whether the hepatitis B virus (HBV) might regulate the synthesis of this enzyme. NOS2 mRNA and protein levels as well as enzyme activity were assessed in cytokine-stimulated HBV-transfected and untransfected hepatoma cells. Transfection with either HBV genome or HBV X gene resulted in induction of NOS2 mRNA expression, and the maximal induction of this transcript and NO production was observed in cytokine-stimulated HBV-transfected cells. These results indicate that hepatotropic viral infections are able to upregulate the NOS2 gene expression in human hepatocytes, suggesting that NO may mediate important pathogenic events in the course of chronic viral hepatitis.
منابع مشابه
EXPRESSION OF INDUCIBLE NITRIC OXIDE SYNTHASE GENE (iNOS) STIMULATED BY HYDROGEN PEROXIDE IN HUMAN ENDOTHELIAL CELLS
Inducible nitric oxide synthase (iNOS) gene expresses a calcium calmudolin-independent enzyme which can catalyse NO production from L-arginine. The induction of iNOS activity has been demonstrated in a wide variety of cell types under stimulation with cytokines and lipopoly saccharide (LPS). Previous studies indicated that all nitric oxide synthases (NOS) activated in human umbilical vein endot...
متن کاملEffect of 17-? Estradiol on the Expression of Inducible Nitric oxide Synthase in Parent and Tamoxifen Resistant T47D Breast Cancer Cells
Indirect evidence suggests that estrogen is involved in the etiology of breast cancer. Estrogen is also thought to modulate nitric oxide (NO) in human breast tumor tissue via regulation of inducible nitric oxide synthase (iNOS). Objectives of this study were to determine whether estradiol (E2) affects iNOS expression level in breast cancer cells and to study the effect of various concentrations...
متن کاملEffect of 17-? Estradiol on the Expression of Inducible Nitric oxide Synthase in Parent and Tamoxifen Resistant T47D Breast Cancer Cells
Indirect evidence suggests that estrogen is involved in the etiology of breast cancer. Estrogen is also thought to modulate nitric oxide (NO) in human breast tumor tissue via regulation of inducible nitric oxide synthase (iNOS). Objectives of this study were to determine whether estradiol (E2) affects iNOS expression level in breast cancer cells and to study the effect of various concentrations...
متن کاملThe Effect of Dexamethasone on Expression of Inducible Nitric Oxide Synthase Gene During Liver Warm Ischemia-reperfusion in Rat
Background: Liver ischemia / reperfusion Injury (IRI) is one of the major causes of liver failure during various types of liver surgery, trauma and infections. The present study investigates the effect of dexsamethasone on the liver injury and inducible nitric oxide synthase gene expression during hepatic warm ischemia/reperfusion in rats. Materials and Methods: 24 male Wistar rats (200-250 g)...
متن کاملAloe vera toxic effects: expression of inducible nitric oxide synthase (iNOS) in testis of Wistar rat
Objective(s): Nitric oxide (NO), a product of inducible nitric oxide synthase (iNOS), contributes in germ cell apoptosis. This study was aimed to evaluate the effects of Aloe vera gel (AVG) on male Wistar rat reproductive organ, serum NO level, and expression of iNOS gene in leydig cells. Materials and Methods:Adult male Wistar rats (n=36) were used for experiments in three groups. The experim...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- The Journal of clinical investigation
دوره 101 7 شماره
صفحات -
تاریخ انتشار 1998