Heatstroke induces liver injury via IL-1ß and HMGB1-induced pyroptosis.

BACKGROUND & AIMS: Liver injury is a common complication of heat stroke (HS), and often constitutes a direct cause for patient death. The cellular and molecular mechanism underlying HS-induced liver injury remains unclear. Recent evidence indicates that inflammasome plays an important role in mediating sterile inflammation triggered by tissue damage. Using a rat HS model, we identified a novel mechanism by which inflammasome-dependent interleukin-1ß (IL-1ß) activation and hepatocyte pyroptosis mediate HS-induced liver injury. METHODS: To induce HS, rats were subjected to heat exposure. Inhibition of inflammasomes was achieved by RNA silencing and pharmacologic inhibitor prior to heat exposure. Inflammasome assembly, caspase-1 activation, histological changes, as well as serum levels of liver enzymes were measured. RESULTS: We demonstrated that the onset of HS activated inflammasome in the liver as evidenced by increased capase-1 activity and the association of inflammasome components NOD-like receptor family pyrin domain containing 3 (Nlrp3) and apoptosis speck-like protein containing a caspase-recruitment domain (ASC); and the activated inflammasome, in turn, induced IL-1ß activation and hepatocyte pyroptosis, and subsequent augmented liver injury. HS-induced hepatocyte inflammasome activation seems to be high-mobility group box 1 (HMGB1) dependent. Inhibition of Nlrp3, caspase-1, or HMGB1 prevented HS-induced liver inflammation and ameliorated liver injury. CONCLUSIONS: These findings demonstrate an important role of HMGB1 in mediating inflammasome activation in the development of liver injury following HS, and suggest that targeting inflammasome may represent a novel therapeutic strategy to limit cell death and prevent liver failure after HS.

Anti-inflammatory secoiridoid glycosides from Gentianella azurea.

A phytochemical investigation on crude extract of Gentianella azurea led to the isolation of ten new (1-10) and one known (11) secoiridoid glycosides. Their structures were unambiguously elucidated by analysis of 1D and 2D NMR. Compounds 2, 5 and 11 were found to inhibit nitric oxide (NO) production in RAW 264.7 macrophages with IC50 values of 52.78 ± 8.61, 0.69 ± 0.23 and 5.18 ± 1.33, respectively, while indomethacin, the positive control, showed an IC50 value of 1.25 ± 0.52 µM.

Curcumin protects intestinal mucosal barrier function of rat enteritis via activation of MKP-1 and attenuation of p38 and NF-κB activation.

BACKGROUND: Intestinal mucosa barrier (IMB) dysfunction results in many notorious diseases for which there are currently few effective treatments. We studied curcumin's protective effect on IMB and examined its mechanism by using methotrexate (MTX) induced rat enteritis model and lipopolysaccharide (LPS) treated cell death model. METHODOLOGY/PRINCIPAL FINDINGS: Curcumin was intragastrically administrated from the first day, models were made for 7 days. Cells were treated with curcumin for 30 min before exposure to LPS. Rat intestinal mucosa was collected for evaluation of pathological changes. We detected the activities of D-lactate and diamine oxidase (DAO) according to previous research and measured the levels of myeloperoxidase (MPO) and superoxide dismutase (SOD) by colorimetric method. Intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor α (TNF-α) and interleukin 1ß (IL-1ß) were determined by RT-PCR and IL-10 production was determined by ELISA. We found Curcumin decreased the levels of D-lactate, DAO, MPO, ICAM-1, IL-1ß and TNF-α, but increased the levels of IL-10 and SOD in rat models. We further confirmed mitogen-activated protein kinase phosphatase-1 (MKP-1) was activated but phospho-p38 was inhibited by curcumin by western blot assay. Finally, NF-κB translocation was monitored by immunofluorescent staining. We showed that curcumin repressed I-κB and interfered with the translocation of NF-κB into nucleus. CONCLUSIONS/SIGNIFICANCE: The effect of curcumin is mediated by the MKP-1-dependent inactivation of p38 and inhibition of NF-κB-mediated transcription. Curcumin, with anti-inflammatory and anti-oxidant activities may be used as an effective reagent for protecting intestinal mucosa barrier and other related intestinal diseases.

Soluble intercellular adhesion molecule-1, D-lactate and diamine oxidase in patients with inflammatory bowel disease.

AIM: To study the levels of serum soluble intercellular adhesion molecule-1 (sICAM-1), plasma D-lactate and diamine oxidase (DAO) in patients with inflammatory bowel disease (IBD), and the potential clinical significance. METHODS: Sixty-nine patients with IBD and 30 healthy controls were included in this study. The concentration of sICAM-1 was detected with enzyme-linked immunosorbent assay, the level of D-lactate and DAO was measured by spectroscopic analysis, and the number of white blood cells (WBC) was determined by routine procedure. RESULTS: The levels of sICAM-l, DAO, and WBC in IBD patients were significantly higher than those in the control group (P < 0.01). sICAM-l in IBD patients was found to be closely related to the levels of DAO and D-lactate (212.94 +/- 69.89 vs 6.35 +/- 2.35, P = 0.000), DAO 212.94 +/- 69.89 vs 8.65 +/- 3.54, P = 0.000) and WBC (212.94 +/- 69.89 vs 7.40 +/- 2.61, P = 0.000), but no significant difference was observed between patients with ulcerative colitis and patients with Crohn's disease. The post-treatment levels of sICAM-l, D-lactate and WBC were significantly lower than before treatment (sICAM-l 206.57 +/- 79.21 vs 146.21 +/- 64.43, P = 0.000), (D-lactate 1.46 +/- 0.94 vs 0.52 +/- 0.32, P = 0.000) and (WBC 7.24 +/- 0.2.33 vs 5.21 +/- 3.21, P = 0.000). CONCLUSION: sICAM-1, D-lactate and DAO are closely related to the specific conditions of IBD, and thus could be used as a major diagnostic index.

[Changyanqing decoction produces anti-inflammatory effect by inhibiting the activation of nuclear factor-kappaB].

OBJECTIVE: To detect the changes in intestinal mucosal permeation in rats with methotrexate-induced small intestinal damage and investigate the protective effects of Changyanqing decoction. METHODS: Rat enteritis model was established by methotrexate (MTX) and sodium chloride. The rats were randomly divided into normal control group, model group, N-acetylcysteine (NAC) group and Changyanqing decoction group, and Changyanqing decoction (100 mg/kg) or saline was administered daily in the corresponding groups by gastric irrigation for 6 days. The disease activity index (DAI), colonic mucosal damage index (CMDI) and histological score (HS) of the rats were observed and evaluated. The levels of mRNA expressions of TNF-alpha and IL-1beta were detected by semi-quantitative RT-PCR. The expression of IL-10 was detected by enzyme linked immunosorbent assay, and IkappaB expression was determined with Western blotting. RESULTS: Compared with the normal control group, the model group showed significantly increased DAI, CMDI and HS. The DAI, CMDI, and HS in rats treated with Changyanqing decoction were significantly decreased in comparison with those in the model group (P<0.01). The expressions of TNF-alpha and IL-1beta were significantly higher in MTX-treated group than in the control group. The expression of TNF-alpha and IL-1beta mRNA in the Changyanqing group and NAC group were significantly lower, but IL-10 significantly higher than those of the MTX group. In MTX group, obvious NF-kappaB activation was observed, whose expression was significantly stronger in the cell nuclei, and the IkappaB in the cytoplasm was markedly degraded. CONCLUSION: Changyanqing decoction offers protection on intestinal mucosa by inhibiting NF-kappaB activation to reduce TNF-alpha and IL-1beta mRNA expressions and increase IL-10 expression.

[Role of Rho-Rock pathways induced by angiotensin II in hepatic stellate cell contraction].

OBJECTIVE: To investigate the mechanism of Ca(2+)-independent pathways mediated by Rho-kinase in contraction of hepatic stellate cells (HSCs) induced by angiotonin II (Ang II). METHODS: Human HSCs of the line HSC-T6 were cultured and randomly divided into 6 groups: negative control group, Ang II group treated by Ang II10 micromol/L for 15 min, Ang II + irbesartan (Ang II receptor inhibitor) group, exposed to irbesartan for 60 min prior to Ang II treatment, Ang II + Y27632 (Rho kinase specific inhibitor) exposed to Y27632 for 60 min prior to Ang II treatment, Ang II + ML-7 (myosin light chain kinase specific inhibitor) + saturo (protein kinase C specific inhibitor) group exposed to stauro for 60 min prior to Ang II treatment, and Ang II + Y27632 + ML-7 + stauro group, exposed to Y27632 and stauro for 60 min prior to Ang II treatment. The cell contraction was detected by silicone-rubber-membrane cultivation directly. The protein levels of MLC and phosphorylated MLC were detected by Western blotting 5, 15, 30, 60, and 120 min after Ang II treatment. RT-PCR was used to detect the expression of Rock2, RhoAGTP, and RhoGEF in Ca(2+)-independent pathways mediated by Rho-kinase. RESULTS: The silicone-rubber-membrane covered by Ang II treated HSCs showed obvious wrinkles indicating the contraction of HSCs. The ratios of phosphorylated MLC protein at the time pints 5, 15, 30, 60, and 120 min of the Ang II group to the control group (0 min) were 11.7 +/- 0.1, 26.9 +/- 0.1, 11.2 +/- 0.1, 4.1 +/- 0.1, and 1.0 +/- 0.1, showing that Ang II increased the phosphorylated MLC protein level time-dependently with the peak level at the time point of 15 minutes. The levels of phosphorylated MLC protein of the Ang II + irbesartan and Ang II + Y27632 groups were (1.12 +/- 0.09)and (1.22 +/- 0.10) respectively, both significantly lower than that of the Ang II group (1.33 +/- 0.06, both P < 0.01). The level of phosphorylated MLC protein of the Ang I + ML-7 + stauro group was (1.43 +/- 0.09), significantly higher than that of the Ang II + Y27632 group (0.64 +/- 0.04, P < 0. 01). The level of phosphorylated MLC protein of the Ang II + Y27632 + ML-7 + stauro group was (0.64 +/- 0.04), significantly lower than that of the Ang II group (P = 0. 003). The mRNA expression levels of Rock2, RhoAGTP, and RhoGEF of the Ang II group were (0.36 +/- 0.01), (0.80 +/- 0.01), and(0.65 +/- 0.11)respectively, all significantly higher than those of the control group [(0.12 +/- 0.01), (0.40 +/- 0.02), and (0.33 +/- 0.09) respectively, all P = 0. 000], and the mRNA expression levels of Rock2, RhoAGTP, and RhoGEF of the Ang II + irbesartan + group were (0.21 +/- 0.02), (0.62 +/- 0.02), and (0.41 +/- 0.10) respectively, all significantly lower than those of the control group. The mRNA expression levels of Rock2 (0.15 +/- 0.01) and RhoGEF (0.28 +/- 0.08) were lower, but The mRNA expression level of RhoAGTP (1.14 +/- 0.02) was higher in the Ang II + Y27632 group. The mRNA expression levels of Rock2, RhoAGTP, and RhoGEF of the Ang II + ML-7 + stauro group were (0.22 +/- 0.01), (0.55 +/- 0.03), and (0.44 +/- 0.10) respectively, all significantly higher than those of the control group. The mRNA expression levels of Rock2, RhoAGTP, and RhoGEF of the Ang II + Y27632 + ML-7 + stauro group were (0.23 +/- 0.01), (0.83 +/- 0.02), and (0.69 +/- 0.08) respectively, all significantly higher than those of the Ang II + ML-7 + stauro group. CONCLUSION: Ang II induces HSCs contraction in Ca(2+)-independent pathways mediated by Rho-kinase.

[Effects of Changyanqing decoction on the expressions of interleukin-10 and intercellular adhesion molecule-1 in rats with ulcerative colitis].

OBJECTIVE: To investigate the effect of Changyanqing decoction, a traditional Chinese medicinal preparation, on the expressions of interleukin-10 (IL-10) and intercellular adhesion molecule-1 (ICAM-1) in the colon mucosa of rats with ulcerative colitis. METHODS: The rats with ulcerative colitis induced by trinitrobenzene sulphonic acid and ethanol enema were randomly divided into 3 groups, namely the model group, sulfasalazine (SASP) group, and Changyanqing decoction group. Daily treatment with intragastric administration and enema of normal saline, SASP (100 mg/kg), and Changyanqing decoction (39.75 mg/kg), respectively, were administered 24 h after the establishment of colitis till the end of the experiment. Another group of rats was used as the normal control group. The disease activity index (DAI) and colon mucosa damage index (CMDI) of the rats were calculated. The activity of myeloperoxidase (MPO) was measured by biochemical method, and the expressions of IL-10 and ICAM-1 protein were measured by ELISA and immunohistochemistry, respectively. RESULTS: Compared with the normal group, the model group showed significantly increased DAI, CMDI, HS score and MPO activity in the colon tissues (P < 0.01), with also significantly increased expression of ICAM-1 (P < 0.01) and decreased expression of IL-10 in the rat colon mucosa (P < 0.01). Treatment with Changyanqing decoction resulted in a significant reduction in DAI, CMDI, HS score and MPO activity (P < 0.01), and decreased the expression of ICAM-1 (P < 0.01) and increased the expression of IL-10 (P < 0.01) in the colon mucosa. The expression of ICAM-1 in the colon mucosa was positively correlated to that of IL-10 (r = 0.927, P < 0.01) and the activity of MPO (r = 0.621, P < 0.01). CONCLUSIONS: Changyanqing decoction has protective effect against rat ulcerative colitis, mediated probably by enhancement of IL-10 expression and reduction in ICAM-1 expression and neutrophil infiltration.

[Effect of angiotensin II on Rho-Rock pathway in rat hepatic stellate cell contraction].

OBJECTIVE: To investigate the mechanisms of angiotonin II (AngII)-induced Ca(2+)-independent pathways mediated by Rho kinase in hepatic stellate cells (HSCs). METHODS: HSC-T6 cells were treated with 1 micromol/L of AngII, and the subsequent cell contraction was directly observed with silicone rubber membrane culture method. The cells with 10 micromol/L AngII treatment were examined for myosin light chain (MLC) phosphorylation level using Western blotting, and the effects of irbesartan (a specific inhibitor of AngII 1- receptor) and Y27632 (a Rho kinase inhibitor) on AngII-induced MLC phosphorylation were evaluated. RT-PCR was used to detect the expression of Rock2 in Ca(2+)- independent pathways mediated by Rho kinase. RESULTS: AngII induced HSC contraction and time-dependent MLC phosphorylation changes, which peaked 15 min after the treatment followed by gradual reduction. Irbesartan or Y27632 treatment significantly lowered MLC phosphorylation level in AngII-induced cells (P<0.01). The mRNA expression of Rock2 increased significantly after AngII treatment (P<0.01), but decreased following subsequent irbesartan or Y27632 treatment. CONCLUSION: AngII induces HSC contraction through Ca(2+)-independent pathways mediated by Rho kinase.

[Protective effect of curcumin against methotrexate-induced small intestinal damage in rats].

OBJECTIVE: To observe the changes in intestinal mucosal permeability in rats with methotrexate (MTX)-induced small intestinal damage and investigate the protective effects of curcumin. METHODS: The experiment was carried out using 4 groups of rats, namely the normal control group, enteritis model group, sulfasalazine (SASP) group and curcumin group. With the exception of the rats in the normal control group, all rats were subjected to intraperitoneal MTX injection to induce enteritis and received subsequent daily intragastric administration of SASP (100 mg/kg), curcumin (100 mg/kg), or normal saline for 5 days. The disease activity index (DAI), colonic mucosal damage index (CMDI) and histological score (HS) of the rats were evaluated. The levels of diamine oxidase (DAO) and D-lactate were assessed using spectrophotometric assay, and myeloperoxidase (MPO) activity and intracellular adhesion molecule-1 (ICAM-1) protein expression were measured by biochemical and immunohistochemical methods, respectively. RESULTS: Compared with the normal control group, the rats in the model group showed significantly increased DAI, CMDI and HS and levels of DAO, D-lactate, ICAM-1 and MPO. Curcumin treatment resulted in significantly decreased DAI, CMDI, HS and lowered activities of D-lactate, ICAM-1 and MPO in comparison with the model group (P<0.01). CONCLUSION: MTX induces increased mucosal permeability of the small intestines in rats, and curcumin may offer protective effects against MTX-induced rat enteritis by lowering the intestinal mucosal permeability.