Curcumin improves experimentally induced colitis in mice by regulating follicular helper T cells and follicular regulatory T cells by inhibiting interleukin-21.

To determine whether curcumin (Cur) can treat mice with experimentally-induced colitis by regulating follicular helper T cells (Tfh) and follicular regulatory T cells (Tfr) by inhibiting interleukin (IL)-21. In this study, 40 male C57BL/6 mice were randomly grouped into four groups, i.e., normal, trinitrobenzene sulfonic acid (TNBS), TNBS + curcumin, and TNBS + anti-IL-21. Mice with experimental colitis were induced by 100 mg/kg TNBS. The mice in the TNBS + Cur group were treated with 100 mg/kg curcumin for seven days, and mice in the TNBS + anti-IL-21 group were treated with anti-IL-21 (150 µg/mouse) once per week, intraperitoneally, starting on the second day after establishing the experimental colitis model. On day eight, the therapeutic effect of curcumin was evaluated by colon mucosa damage index (CMDI), histological examination, and disease activity index (DAI). Furthermore, the number of CD4 + CXCR5 + PD-1 + Tfh and CD4 + CXCR5 + FoxP3 + Tfr cells were measured by flow cytometry. The mRNA and protein expression of IL-21, Bcl-6, FOXP3, ICOS, and PD-1 in colonic mucosa was detected by reverse transcription polymerase chain reaction and the Western blot technique. Compared with the TNBS group, the DAI, CMDI, histological score, the number of CD4 + CXCR5 + PD-1 + Tfh cells, the expression of IL-21, Bcl-6, ICOS, and PD-1 were significantly decreased in the TNBS + curcumin group and TNBS + anti-IL-21 group; body weight, number of CD4 + CXCR5 + FoxP3 + Tfr cells, and the expression of FoxP3 were observably elevated in the TNBS + curcumin group (all P < 0.05). Curcumin may have a potential therapeutic effect on mice with colitis treated experimentally through regulation of the balance of Tfh and Tfr cells via inhibiting the synthesis of IL-21.

Exogenous expression of p21(WAF1/CIP1) exerts cell growth inhibition and enhances sensitivity to cisplatin in hepatoma cells.

The effects of exogenous expression of p21(WAF1/CIP1) in hepatoma cells were examined. Two stably p21(WAF1/CIP1)-transfected clones and one clone transfected with expression vector only were used for study. Introduction of p21(WAF1/CIP1) resulted in significant cell growth inhibition, and the magnitude of the cell growth inhibition in these transfected cells was proportional to the level of p21(WAF1/CIP1) protein expressed. Exogenous p21(WAF1/CIP1) expression also significantly enhanced chemosensitivity to cisplatin. In addition, apoptosis occurred earlier in cells transfected with p21(WAF1/CIP1) after cisplatin treatment. These findings raise the potential that forced upregulation of p21(WAF1/CIP1) in hepatocellular carcinoma (HCC) may reduce the doses of cisplatin to achieve similar responses and suggest the possible use of p21(WAF1/CIP1) in HCC treatment.

Expression of p27(KIP1) and p21(WAF1/CIP1) in primary hepatocellular carcinoma: clinicopathologic correlation and survival analysis.

To investigate the possible roles of p27(KIP1) and p21(WAF1/CIP1), inhibitors of cyclin-dependent kinases, in hepatocellular carcinoma (HCC), we examined p27(KIP1) and p21(WAF1/CIP1) expression in primary HCC with immunohistochemistry and Northern blot hybridization and correlated the results with clinicopathologic features and survival. With immunohistochemistry, positive staining for p27(KIP1) and p21(WAF1/CIP1) protein was found in 54.3% and 63.8% of HCCs, respectively. Both p27(KIP1) and p21(WAF1/CIP1) scores of the tumors were significantly higher than those of the corresponding nontumorous livers (P <.0001 and.009, respectively). Higher levels of p27(KIP1) were associated with a lower incidence of direct liver invasion (P =.021) and, less significantly, with a low incidence of multiple tumor nodules (P =.056). Patients whose tumors had higher p27(KIP1) protein scores had longer disease-free survival (P =.011). For p21(WAF1/CIP1), in contrast to the overexpression of the p21(WAF1/CIP1) protein in HCC, the relative amounts of p21(WAF1/CIP1) messenger RNA (mRNA) in the tumors were found to be reduced compared with those of the nontumorous livers (P =.039). In conclusion, p27(KIP1) and p21(WAF1/CIP1) proteins were frequently overexpressed in HCC. Longer disease-free survival rates were seen in patients whose tumors had higher p27(KIP1) expression. The accumulation of p21(WAF1/CIP) protein in the presence of a reduced mRNA level suggests probable posttranslational protein stabilization, and the reduced transcription of p21(WAF1/CIP) may represent a form of dysfunction of cyclin-dependent kinase inhibitor involved in hepatocarcinogenesis.

Liver transplantation in rats using small-for-size grafts: a study of hemodynamic and morphological changes.

BACKGROUND: Damage to a small-for-size liver graft after reperfusion is frequently observed but the mechanism of injury remains unclear. HYPOTHESIS: Injury to a small-for-size liver graft is related to the changes of portal pressure and blood flow. MAIN OUTCOME MEASURES: Survival rates, portal hemodynamics, microcirculatory changes, and morphological changes (by light microscopy and electron microscopy). SETTING: A rat model of nonarterialized orthotopic liver transplantation comparing 2 groups of rats transplanted with whole grafts (100% of recipient liver weight) and small-for-size grafts (30% of recipient liver weight). RESULTS: Median survival of the rats with small-for-size grafts was 30 hours (range, 27-37 hours). During the first 15 minutes after reperfusion, mean arterial pressure of the small-for-size graft group was significantly lower than that of the whole graft group (10-minute: 100 vs 132 mm Hg, P =.04; 15-minute: 96 vs 127 mm Hg, P =.04). Portal pressure (in centimeters of water) of the small-for-size graft group was significantly higher in the first 20 minutes after reperfusion than the level before the anhepatic phase (5-minute: 15.1 vs 9.3, P =.02; 10-minute: 16.1 vs 9.3, P =.03; 15-minute, 13.5 vs 9.3, P =.03; 20-minute: 13.4 vs 9.3, P =.03) and was significantly higher than that of the whole graft group in the first 10 minutes after reperfusion (5-minute: 15.1 vs 9.6, P =.02; 10-minute: 16.1 vs 10.3, P =.04). Hepatic microcirculatory blood flow (in milliliters per minute per 100 g) was also significantly higher in the small-for-size graft group during the first 40 minutes after reperfusion (5-minute: 16.3 vs 9.3, P =.02; 10-minute: 14.9 vs 6.6, P =.02; 15-minute: 14.8 vs 5.5, P =.02; 20-minute: 13.1 vs 7.0, P =.02; 30-minute: 13.2 vs 8.8, P =.04; 40-minute: 14.6 vs 7.1, P =.02). Light and electron microscopy showed normal morphological features of whole graft up to 24 hours after reperfusion. The small-for-size graft, however, showed sinusoidal congestion, tremendous swelling of mitochondria of hepatocytes, irregular large gap of sinusoidal lining cells, and collapse of the space of Disse. CONCLUSIONS: In a rat model, the portal hemodynamic changes in small-for-size grafts are transient. Progressive damage of the graft may result from microcirculatory failure due to irreversible endothelial injury after reperfusion.

p21/WAF1, p53 and PCNA expression and p53 mutation status in hepatocellular carcinoma.

The cyclin-dependent kinase inhibitor p21/WAF1 is regulated by p5S3-dependent and p53-independent pathways. In addition, p21/WAF1 binds with proliferating cell nuclear antigen (PCNA) and inhibits the action of PCNA. To investigate the possible role of p21/WAF1 in human hepatocellular carcinomas (HCCs), we examined the expression of p21/WAF1 and its relation with PCNA and p53 expression in 97 surgically resected HCCs by immunohistochemistry and with the mutation status of p53 in 26 HCCs. p53 mutation status was examined by direct DNA sequencing using 3 sets of primers covering exons 5-9. Six of the 26 tumors showed p53 point mutations and only 33% of these HCCs demonstrated p21/WAF1 expression. In contrast, 75% of HCCs without p53 mutations showed p21/WAF1 expression. Of all 97 HCCs, p21/WAF1 expression was significantly higher in the tumors than in corresponding non-tumorous liver. When the tumors were stratified into 2 groups by the median tumor p21/WAF1 score, those with higher expression were found to have a lower incidence of multiple tumor nodules (p = 0.008) and tumor microsatellite formation (p = 0.050). The tumor p21/WAF1 score was positively associated with tumor PCNA expression (p = 0.036) but not with tumor p53 expression. Thus, in HCC, expression of p21/WAF1 is in part dependent on p53 status, but a p53-independent pathway also plays a significant role in the regulation of p21/WAF1 expression. High p21/WAF1 expression is significantly associated with solitary tumor nodules and, to a lesser extent, tumor microsatellites but may not be enough to suppress tumor progression.