Hepatitis B Virus (HBV)

Category: Ascorbic Acid

Modulation of 72-Kilodalton Type IV Collagenase: DISCUSSION(2)

Vitamin C did not directly deactivate MMP-2 but had an effect on MMP-2 genomic expression as revealed by the Western blots, Northern blots, and run-on assays. Down-regulation of MMP-2 gene expression by vitamin C is exerted at physiologic concentrations if we consider the concentrations in amniotic fluid a good indicator of what is occurring inside […]

Modulation of 72-Kilodalton Type IV Collagenase: DISCUSSION(1)

Type I, type III, and type IV collagens are the main structural constituents of chorioamniotic membranes, and they are responsible for the strength and flexibility of the membranes. In this study, it was demonstrated that vitamin C, in addition to its well-known role in collagen biosynthesis, modulates the degradation of this protein. The regulatory effect of […]

Modulation of 72-Kilodalton Type IV Collagenase: RESULTS(2)

Equimolar amounts of glutathione did not affect the basal expression of MMP-2 (Fig. 1B). According to semiquantitative den-sitometric analysis and taking the vitamin C-free cell media as 100%, residual activity was approximately 60% in the 29 ^g/ml dose (range from 53% to 72%, n = 8) and 18% in the 200 ^g/ml vitamin C dose […]

Modulation of 72-Kilodalton Type IV Collagenase: RESULTS(1)

Media from WISH cells incubated in the absence of vitamin C showed a gelatinase-specific activity (mean ± SD, n = 8) of 124.3 ± 4.9 ^g degraded gelatin/^g protein. Gelatinolytic-specific activity decreased progressively with 10 ^g of vitamin C to 82.1 ± 9.7, with 29 ^g to 63.0 ± 7.8, with 50 ^g to 52.6 […]

Modulation of 72-Kilodalton Type IV Collagenase: MATERIALS AND METHODS(3)

Western Blotting Ten micrograms of protein from conditioned media per lane was applied to a 10% SDS-polyacrylamide gel under nonreducing conditions. Protein electrotransference to Im-mobilon-P membranes (Millipore, Medford, MA) using a semi-dry system was performed according to Towbin et al.. Membrane was developed with monospecific polyclonal antibodies against 72-kDa type IV collagenase (MMP-2), generously donated […]

Modulation of 72-Kilodalton Type IV Collagenase: MATERIALS AND METHODS(2)

Vitamin C Quantitation Ascorbic acid was quantitated at different times (0-4 h) to ensure that vitamin C was present under experimental conditions. Medium and cells were precipitated with 0.35 M perchloric acid, and their filtrates were processed for HPLC. Chromatography was carried out as suggested by Lee et al.. Intracellular ascorbic acid was normalized to […]

Modulation of 72-Kilodalton Type IV Collagenase: MATERIALS AND METHODS(1)

Cell Culture WISH cells, a line of human amnion cells (American Type Culture Collection, Rockville, MD; ATCC CCL5) were cultured in 25-cm2 flasks. Cells were grown in Dul-becco’s Modified Eagle’s medium, supplemented with 10% fetal calf serum (Gibco BRL, Gaithersburg, MD), 25 mM Hepes, 110 mg/L sodium pyruvate, and 20 mM L-gluta-mine, in a 95% […]