The role of hepatic expression of STAT1, SOCS3 and PIAS1 in the response of chronic hepatitis C patients to therapy.

BACKGROUND: The underlying mechanisms of hepatitis C virus (HCV) resistance to treatment are unknown. Signal transducers and activators of transcription (STAT) proteins play a critical role in antiviral defense. OBJECTIVE: To explore some of the mechanisms of HCV resistance to interferon, the expression of STAT1 and its negative regulators, protein inhibitor of activated STAT (PIAS1) and suppressor of cytokine signalling (SOCS3), in liver tissues of both inteferon responders and nonresponders in chronic HCV patients. METHODS: Sixty patients were divided into the following groups: group 1a comprised 38 treatment-responder chronic HCV patients; group 1b consisted of 22 treatment-nonresponder chronic HCV patients; and group 2 consisted of six control subjects. Liver biopsies were examined for histological scoring; STAT1, SOCS3 and PIAS1 expression was analyzed using Western blotting methods. RESULTS: STAT1 expression in the liver tissue of patients in group 1 was significantly increased compared with group 2 patients (P=0.001), while no significant difference in expression was observed between group 1a and group 1b patients (P=0.747). However, phosphorylated STAT1 protein was expressed at a significantly higher level in liver tissue of patients in group 1a compared with patients in group 1b (P=0.001). Western blot analysis of PIAS1 and SOCS3 protein expression in liver tissues from groups 1 and 2 revealed significantly increased expression in group 1 compared with group 2 (P=0.001). In addition, PIAS1 and SOCS3 protein expression was significantly higher in the liver tissues of patients in group 1b compared with patients in group 1a. CONCLUSION: Levels of STAT1 and/or the protein expression of its negative regulators, PIAS1 and SOCS3, may be a good predictor of response to therapy. These could be used as biomarkers that are easily detected by Western blotting or immunostaining during standard histopathological liver biopsy analysis.

Angiotensin II type 1 receptor gene polymorphism and telomere shortening in essential hypertension.

Several genetic studies were carried out among hypertensive patients to assess allelic association at the 1166 position of the 3' untranslated region of angiotensin II type 1 receptor gene. In addition, attempts have also been made to find out whether telomere length attrition is associated with hypertension. The main aim of this study was to examine the association of A1166C polymorphism of angiotensin II type 1 receptor and telomere length with essential hypertension in Egyptian people. Angiotensin II type 1 genotyping and relative telomere length were investigated by PCR in 40 patients of essential hypertension and 15 healthy controls. The homozygous AA1166 allele frequency was 92.8% among the studied subjects. There was no intergroup variation in A allele frequency in normotensive group. The frequency of homozygous A allele was significantly higher in hypertensive than normotensive subjects (97.5 and 80%, respectively) with higher frequencies in male patients. The average telomere length ratio was significantly shorter in hypertensive than in normal subjects (1.08 ± 0.3 and 1.54 ± 0.18, respectively). No correlation was observed between telomere length ratio and body mass index. This study suggests that the homozygous A1166 allele of angiotensin II type 1 and short telomeres may be predisposing factors for essential hypertension in Egyptians and may be involved in the pathogenesis of the disease. Further strategies for treating high-risk patients could result in prevention or delay of end organ damage.