Production of septal fibrosis of the liver by means of foreign protein injections into rats

Antigen Recognition Patterns of Intestinal Capillariasis Using Immunoblot-Based Serodiagnosis

BACKGROUND

Diagnosis of intestinal capillariasis depending on microscopic detection of parasitic stages is of low sensitivity, especially in cases with low worm burden. There is a necessity to develop sensitive and specific diagnostic tools of capillariasis for early treatment to avoid complications. Western blot (WB) technique showed promising results for antigen recognition patterns in several parasitic infections.

AIM OF THE STUDY

This study is directed to identify and evaluate relevant proteins of intestinal capillariasis crude worm antigens using WB immunodiagnosis.

MATERIALS AND METHODS

Capillaria crude worm antigens were extracted and analyzed using SDS-PAGE. Sixty serum samples belonging to 3 groups (20 individuals each) were included; Group I (shedding Capillaria in feces), Group II (infected with other parasites) and Group III (negative parasitological results). Reactivity of the resulting bands of Capillaria with serum samples was analyzed using WB technique.

RESULTS

Thirty-two immunoreactive bands were detected in WB analysis representing recognition of proteins with molecular weights (MW) varying from 19 to 110 kDa. Immunodominant proteins of 23.5, 31, 36.5, 40.5 and 44 kDa were recognized, respectively, in 35%, 30%, 85%, 95% and 75% of sera from patients with confirmed capillariasis and in 30%, 25%, 35%, 25%, and 20% of sera from those infected with other parasitic infections. One serum sample from group III gave reaction with 31 kDa band.

CONCLUSION

Immunodiagnosis of intestinal capillariasis using WB proved that 23.5, 31, 36.5, 40.5 and 44 kDa bands could be considered useful tools for diagnosis of capillariasis.

Depletion of β-arrestin2 in hepatic stellate cells reduces cell proliferation via ERK pathway

β-Arrestins are multifunctional adaptor proteins. Recently, some new roles of β-arrestins in regulating intracellular signaling networks have been discovered, which regulate cell growth, proliferation, and apoptosis. Though, the role of β-arrestins expression in the pathology of hepatic fibrosis remains unclear. In this study, the possible relationship between the expression of β-arrestins with the experimental hepatic fibrosis and the proliferation of hepatic stellate cells (HSCs) were investigated. Porcine serum induced liver fibrosis was established in this study. At five time points, the dynamic expression of β-arrestin1, β-arrestin2, and α-smooth muscle actin (α-SMA) in rat liver tissues, was measured by immunohistochemical staining, double immunofluorescent staining, and Western blotting. This study showed that aggravation of hepatic fibrosis with gradually increasing expression of β-arrestin2 in the hepatic tissues, but not β-arrestin1. Further, as hepatic fibrosis worsens, β-arrestin2-expressing activated HSCs accounts for an increasingly larger percentage of all activated HSCs. And the expression of β-arrestin2 had a significant positive correlation with the expression of α-SMA, an activated HSCs marker. In vitro studies, the dynamic expression of β-arrestin1 and β-arrestin2 in platelet derived growth factor-BB (PDGF-BB) stimulated HSCs was assessed by Western blotting. The expression of β-arrestin2 was remarkably increased in PDGF-BB stimulated HSCs. Furthermore, the small interfering RNA (siRNA) technique was used to explore the effect of β-arrestins on the proliferation of HSCs and the activation of ERK1/2. Transfection of siRNA targeting β-arrestin2 mRNA (siβ-arrestin2) into HSCs led to a 68% and 70% reduction of β-arrestin2 mRNA and protein expression, respectively. siβ-arrestin2 abolished the effect of PDGF-BB on the proliferation of HSCs. In addition, siβ-arrestin2 exerted the inhibition of the activation of ERK1/2 in HSCs. The present study provided strong evidence for the participation of the β-arrestin2 in the pathogenesis of hepatic fibrosis. The β-arrestin2 depletion diminishes HSCs ERK1/2 signaling and proliferation stimulated by PDGF-BB. Selective targeting of β-arrestin2 inhibitors to HSCs might present as a novel strategy for the treatment of hepatic fibrosis.

Capillaria hepatica in rats: focal parasitic hepatic lesions and septal fibrosis run independent courses

Capillaria hepatica causes two main lesions in the liver of rats: multifocal chronic inflammation, directly related to the presence of disintegrating parasites and their eggs, and a process of systematized septal fibrosis. The comparative behavior of these two lesions was investigated in rats experimentally infected with 600 embryonated eggs, following either corticosteroid treatment or specific antigenic stimulation, in an attempt to understand the relationship between these two lesions, and the pathogenesis of septal fibrosis. The two treatments differently modified the morphological aspects of the focal parasitic-related lesions, but did not interfere with the presentation of diffuse septal fibrosis, although a mild decrease in the degree of fibrosis occurred in corticoid-treated animals. These findings indicate that although the two lesions are C. hepatica induced, they are under different pathogenetic control, the induction of septal fibrosis being triggered during early infection to follow an independent pathway.