ABSTRACT: The mechanisms that regulate nitric oxide (NO)-induced apoptosis, especially in T cell apoptosis, are largely uncharacterized. Here, we report that protection from NO-induced cell death by phorbol 12-myristate 13-acetate (PMA) is dependent on both p38 and extracellular signal-regulated kinase (ERK) activation. Exposure of Molt4 cells to NO donor S-nitroso-N-acetyl-DL-penicillamine (SNAP) induced both apoptotic and necrotic modes of cell death along with a sustained increase in p38 kinase phosphorylation. However, the p38 inhibitor SB202190 only slightly protected Molt4 cells from NO toxicity. In contrast, PMA rapidly phosphorylated both p38 kinase and ERK, and the phosphorylation statuses were not altered in the presence of SNAP. Interestingly, although each mitogen-activated protein kinase (MAPK) inhibitor by itself had only a modest effect, the combination of inhibitors for both MAPKs almost completely abolished the protective effect of PMA. Furthermore, dominant negative or catalytically inactive variants that modulate p38 and ERK mimicked the effects of MAPK inhibitors. We located the action of p38 and ERK upstream of the p53/mitochondrial membrane potential loss and caspases cascade. Together, these findings suggest that the PMA-induced activations of ERK and p38 kinase are parallel events that are both required for inhibition of NO-induced death of Molt4 cells.
Free Radical Biology and Medicine 09/2004; 37(4):463-79. · 5.42 Impact Factor
ABSTRACT: Although the viral load is correlated with HBcAg, liver injury was not correlated to viral load in HBeAg positive patient. We aimed to study the inter-relationship of clinical parameters such as the level of HBV-DNA, the level of aminotransferase, intrahepatic expression of HBcAg and severity of histological liver damage in the young male chronic HBV carriers according to HBeAg status.
The study group included 85 young male patients (mean age: 19.8) with biopsy-proven chronic hepatitis B (HBeAg-positive group: n=60, HBeAg-negative group: n=25).
Serum levels of HBV-DNA and the expression of intrahepatic HBcAg in the HBeAg-positive group were significantly higher than in the HBeAg-negative (p<0.001), but fibrosis score was lower (p<0.01). Serum levels of HBV-DNA positively correlated with lobular activity, portal/periportal activity, biochemical activities in the HBeAg-negative group but negatively correlated in the HBeAg-positive group. There were no significant differences in histological activity according to the pattern of expression of intrahepatic HBcAg in both groups. The lobular activity correlated positively with biochemical activity in both groups, and portal/periportal activity correlated with biochemical activity only in the HBeAg-positive group.
There are close correlations among liver injury, intrahepatic expression of HBcAg, and detectable HBV-DNA in the young male chronic HBV carriers with HBeAg-negativity, but in the HBeAg-positive group, the correlations are diversified.
The Korean journal of gastroenterology = Taehan Sohwagi Hakhoe chi 08/2004; 44(2):84-92.
ABSTRACT: Hepatitis B virus (HBV) was classified into 8 genotypes by a sequence divergence in the entire genome designated from A to H. HBV genotypes have distinct geographic distributions. Recently, HBV genotypes have been partially found as influencing the clinical manifestation of chronic liver disease in hosts. In Korea, the distribution of HBV genotypes remains unclear. The aim of this study was to evaluate the prevalence of the HBV genotype on Jeju Island.
Hepatitis B virus genotypes were evaluated among 107 hepatitis B carriers residing on Jeju Island. We used single PCR and multiplex-PCR assay with genotype-specific primer pairs for HBV genotypes A-F for the genotyping.
1. Fifty nine samples (55%) were positive for HBV DNA. The positivity was different according to the pattern of HBeAg/ anti-HBe expression, as -/-; 2/3 (66.7%), -/+; 30/73 (30%), +/-; 24/28 (85.7%) and +/+; 3/3 (100%). 2. In the single primer set of genotype-specific PCR, 59 samples (100%) were detected as genotype C and 2 (3%) were also detected as genotype A and B. 3. In multiplex-PCR, 58 samples (98%) were detected as genotype C and only one (2%) as a mixed pattern of genotype B and C. 4. When the PCR products were amplified with universal sense and genotype specific anti-sense from one genotype A, one B, and 2 C, all were included in genotype C.
These results suggest that on Jeju Island, almost all HBV genotypes are C.
The Korean Journal of Hepatology 04/2004; 10(1):42-50.