LPS-induced NF-kappa B activation requires Ca2+ as a mediator in isolated pancreatic acinar cells of rat / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the effect of Ca(2+) on lipopolysaccharide (LPS)-induced NF-kappa B activation in pancreatic acinar cells and the role of NF-kappa B in LPS-induced acinar cell injury.</p><p><b>METHODS</b>Male rat pancreatic acinar cells were isolated by collagenase digestion, then exposed to varying concentrations of LPS (from 1 to 20 mg/L) in the presence or absence of EGTA. At various time points (30 minutes, 1 hour, 2 hours, 4 hours and 10 hours) after treatment with the agents, cell viability was determined by MTT. Nuclear translocation of NF-kappa B's subunit p65 was visualized by immunofluorescence staining and nuclei protein was extracted to perform EMSA which was used to assay the activity of NF-kappa B binding to the DNA sequence containing the recognition site of NF-kappa B.</p><p><b>RESULTS</b>LPS induced cell damage in a time- and concentration-dependent manner while EGTA attenuated LPS-induced cell damage (P < 0.05). NF-kappa B p65 immunofluorescence staining had increased intensity in the cytoplasm and indicated that nuclear translocation occurred within 30 minutes and its zenith was reached at 1 hour after LPS (10 mg/L) treatment. Testing of NF-kappa B DNA binding activity showed the same alteration phase as p65 immunofluorescence staining. NF-kappa B activation preceded the pathological alteration of pancreatic acinar cells. The Ca(2+) chelator EGTA inhibited LPS-induced NF-kappa B activation.</p><p><b>CONCLUSIONS</b>NF-kappa B activation is an important early event in LPS-induced injury to pancreatic acinar cells. Ca(2+) is an important mediator in the process of LPS-induced NF-kappa B activation.</p>

The effects of sulindac on induction of apoptosis and expression of cyclooxygenase-2 and Bcl-2 protein in human hepatocellular carcinoma cells / 中华消化杂志

Objective To investigate the value of sulindac in chemoprevention and treatment of human hepatocellular carcinoma. Methods The hepatocellular carcinoma cell(HCC) lines (SMMC 7721 and HepG 2) were used in this study. Antiproliferation effects was measured by MTT assay, and apoptosis, cyclooxygenase 2 (COX 2) and Bcl 2 were detected by Western dot blotting. Results The growth inhibition and apoptosis of HCC cells could be induced by sulindac in a dose and time dependent manner. The effects of growth inhibition and apoptosis induction were different between 2 cell lines. After 24 hours of incubation with sulindac at the concentration of 2 mmol/L and 4 mmol/L, the expression of COX 2 and Bcl 2 were markedly reduced. Conclusions Sulindac could inhibit the growth of two HCC cell lines effectively in vitro by induction of apoptosis, which were associated with the inhibition of COX 2 and Bcl 2 expression.