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Background: Congenital heart block (CHB) is a transplacentally acquired autoimmune disease associated with anti-Ro/SSA and anti-La/SSB maternal autoantibodies and is characterized primarily by atrioventricular (AV) block of the fetal heart. This study aims to investigate whether the T-type calcium channel subunit α1G may be a fetal target of maternal sera autoantibodies in CHB. Methodology/Principal Findings: We demonstrate differential mRNA expression of the T-type calcium channel CACNA1G (α1G gene) in the AV junction of human fetal hearts compared to the apex (18–22.6 weeks gestation). Using human fetal hearts (20–22 wks gestation), our immunoprecipitation (IP), Western blot analysis and immunofluorescence (IF) staining results, taken together, demonstrate accessibility of the α1G epitope on the surfaces of cardiomyocytes as well as reactivity of maternal serum from CHB affected pregnancies to the α1G protein. By ELISA we demonstrated maternal sera reactivity to α1G was significantly higher in CHB maternal sera compared to controls, and reactivity was epitope mapped to a peptide designated as p305 (corresponding to aa305–319 of the extracellular loop linking transmembrane segments S5–S6 in α1G repeat I). Maternal sera from CHB affected pregnancies also reacted more weakly to the homologous region (7/15 amino acids conserved) of the α1H channel. Electrophysiology experiments with single-cell patch-clamp also demonstrated effects of CHB maternal sera on T-type current in mouse sinoatrial node (SAN) cells. Conclusions/Significance: Taken together, these results indicate that CHB maternal sera antibodies readily target an extracellular epitope of α1G T-type calcium channels in human fetal cardiomyocytes. CHB maternal sera also show reactivity for α1H suggesting that autoantibodies can target multiple fetal targets. [ABSTRACT FROM AUTHOR]

Oxidative stress plays a causative role in the development of hepatic fibrosis and apoptosis. Estradiol (E2) is an antioxidant, and idoxifene is a tissue-specific selective estrogen-receptor modulator. We have previously demonstrated that E2 inhibits hepatic fibrosis in rat models of hepatic fibrosis and that the actions of E2 are mediated through estrogen receptors (ERs). This study reports on the antiapoptotic role of idoxifene and E2, and the functions of ER subtypes ER-alpha and ER-beta in hepatocytes undergoing oxidative stress. Lipid peroxidation was induced in cultured rat hepatocytes with ferric nitrilotriacetate solution with idoxifene or E2. Oxidative stress-induced early apoptosis was linked to its ability to inhibit not only the expression of Bcl-2 and Bcl-XL but the production of antioxidant enzymes as well and to stimulate Bad expression. Hepatocytes possessed functional ER-beta, but not ER-alpha, to respond directly to idoxifene and E2. Idoxifene and E2 suppressed oxidative stress-induced reactive oxygen species generation and lipid peroxidation, and their antiapoptotic effects on the activation of activator protein-1 and nuclear factor-kappaB, the loss of antioxidant enzyme activity, and Bcl-2 family protein expression in early apoptotic hepatocytes were blocked by the pure ER antagonist ICI 182,780. Our results indicate that idoxifene and E2 could enhance antiapoptotic activity through ER-beta during oxidative damage in hepatocytes. [ABSTRACT FROM AUTHOR]

Purpose: Sigma receptor 1 (Sigma1R), a nonopioid putative molecular chaperone, has neuroprotective properties in retina. This study sought to determine whether delaying administration of (+)-pentazocine, a high-affinity Sigma1R ligand after onset of diabetes in Ins2Akita/+ diabetic mice would afford retinal neuroprotection and to determine consequences on retinal phenotype in Ins2Akita/+ diabetic mice in the absence of Sigma1R., Methods: Ins2Akita/+ diabetic and WT mice received intraperitoneal injections of (+)-pentazocine beginning 4 or 8 weeks after onset of diabetes; eyes were harvested at 25 weeks. Retinal histologic sections were analyzed to determine thicknesses of retinal layers, number of ganglion cells, and evidence of gliosis (increased glial fibrillary acidic protein levels). Ins2Akita/+/Sig1R-/-mice were generated and subjected to in vivo assessment of retinal architecture (optical coherence tomography [OCT]) and retinal vasculature using fluorescein angiography (FA) at 12 and 16 weeks compared with age-matched Ins2Akita/+ mice. Eyes were then harvested for retinal morphometric assessment and gliosis assessment., Results: Wild-type mice had 13 ± 0.06 cells/100 μm retinal length; cell bodies in Ins2Akita/+ mice injected 4 and 8 weeks after onset of diabetes with (+)-pentazocine retained significantly more ganglion cells compared with Ins2Akita/+ mice (9 ± 0.04) and demonstrated significant attenuation of gliosis. Ins2Akita/+/Sig1R-/-mouse retinas, analyzed to determine whether the Ins2Akita/+ phenotype was accelerated when lacking Sigma1R, revealed increased nerve fiber layer thickness (OCT), evidence of vitreal opacities, and vessel beading (FA) compared with Ins2Akita/+ mice. Morphometric analysis revealed significantly fewer ganglion cells in Ins2Akita/+/Sig1R-/-mice compared with Ins2Akita/+ mice., Conclusions: Sigma1R may be a novel retinal stress modulator, and targeting it even after disease onset may afford retinal neuroprotection.

The study examines the clinical significance of guanase (GU) measurement in patients with hepatitis C. 688 patients in whom either ALT was abnormal, or in whom HBsAg or HCVAb was detected in the serum, were enrolled into this study. The percentage of cases in which normal ALT while elevated GU was compared among the different disease groups. Then, the percentage of cases with normal ALT but elevated GU was compared between HBV and HCV groups. For the entire population, a significant correlation was observed between ALT and GU (r=0.872). The overall percentage of cases with normal ALT but elevated GU activity was 11.4%. In HCV group, 449 cases had normal ALT. Of these cases, 20.3% had elevated GU, while ALT was normal. Before 1989, no test to check donated blood for HCV antibody was available. However, screening of donated blood for high GU was associated with a reduced incidence of post-transfusion hepatitis. This is probably because following the screening, blood donated by patients with hepatitis C who had normal ALT but elevated GU was rejected. After the introduction of HCV antibody measurement, GU measurement is still useful to reveal the pathophysiological condition in-patients with chronic hepatitis type C.

Oxidative stress has been implicated as a cause of hepatic fibrosis, and hepatic stellate cells (HSCs), which are the most important collagen-producing cell types, have been reported to be activated by lipid peroxidation products. Antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GPx) provide a defense system that plays a critical role in protecting the cell from free radical damage, particularly lipid peroxidation. To elucidate the antioxidant activity of interferon-alpha (IFN-alpha), the effects of IFN-alpha on rat hepatocytes undergoing oxidative stress and HSCs in primary culture as well as isolated rat liver mitochondria were examined. IFN-alpha was observed to dose-dependently increase the immunoreactive protein levels of copper, zinc-and manganese-dependent SOD as well as the enzyme activities of GPx, and decrease the lipid peroxidation product levels and oxidative burst both in stressed hepatocytes and activated HSCs; GPx activities, however, were not detected in the latter cells. IFN-alpha also inhibited HSC activation and lipid peroxidation in liver mitochondria. These findings suggest that IFN-alpha may enhance biological defense activities against oxidative stress and function as a potent fibrosuppressant by protecting hepatocytes and hepatic stellate cells from lipid peroxidation in vivo.