Intravenous high mobility group box 1 upregulates the expression of HIF-1α in the myocardium via a protein kinase B-dependent pathway in rats following acute myocardial ischemia.

The effects of intravenous high mobility group box 1 (HMGB1) on myocardial ischemia/reperfusion (I/R) injury remains to be elucidated. The purpose of the present study was to investigate the effects of intravenous HMGB1 on the expression of hypoxia inducible factor-1α (HIF-1α) in the myocardium of rats following acute myocardial ischemia, and to examine the effects of intravenous HMGB1 on myocardial I/R injury. Male Wistar rats were divided into the following groups: Sham operation group (n=10), a group exposed to ischemia for 30 min and reperfusion for 4 h (I/R group) as a control (n=10), an HMGB group, in which 100 ng/kg HMGB was administered intravenously 30 min prior to ischemia (n=10), an LY group, in which LY294002, an inhibitor of phosphoinositide 3-kinase (PI3K), was administered intravenously (0.3 mg/kg) 40 min prior to ischemia (n=10), and the HMGB1+LY group, in which HMGB1 (100 ng/kg) and LY294002 (0.3 mg/kg) were administered intravenously 30 min and 40 min prior to ischemia, respectively (n=10). The serum levels of cardiac troponin I (cTnI) and tumor necrosis factor-α (TNF-α), and myocardial infarct size were measured. The expression levels of phosphorylated Akt and HIF-1α were investigated using western blot analyses. The results showed that pre-treatment with HMGB1 significantly decreased serum levels of cTnI, and TNF-α, and reduced myocardial infarct size following 4 h reperfusion (all P<0.05). HMGB1 also increased the expression levels of HIF-1α and p-Akt induced by I/R (P<0.05). LY294002 was found to eliminate the effects of intravenous HMGB1 on myocardial I/R injury (P<0.05). These results suggest that intravenous pre-treatment with HMGB1 may exert its cardioprotective effects via the upregulation of the myocardial expression of HIF-1α, which may be regulated by the PI3K/Akt signaling pathway, in rats following acute myocardial I/R.

Postconditioning with simvastatin decreases myocardial injury in rats following acute myocardial ischemia.

The aim of the present study was to investigate whether postconditioning with simvastatin attenuated myocardial ischemia reperfusion injury by inhibiting the expression of high mobility group box 1 (HMGB1) in rat myocardium following acute myocardial ischemia. In total, 30 male Sprague-Dawley rats were divided into sham operation (sham; n=10), acute myocardial infarction (AMI; n=10) and simvastatin (sim; n=10) groups. The AMI and sim groups were subjected to ischemia for 30 min, followed by reperfusion for 180 min. The rats in the sim group were administered 20 mg/kg simvastatin intravenously 5 min prior to reperfusion. Subsequently, the infarct size, serum cardiac troponin (c-TnI), tumor necrosis factor (TNF)-α and myocardial malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity were measured. Western blot analysis was used to detect the protein expression of HMGB1. Postconditioning with simvastatin was shown to decrease the infarct size and HMGB1 expression levels in the myocardium following AMI (P<0.05). In addition, postconditioning with simvastatin not only decreased the serum levels of c-TnI and TNF-α (P<0.05), but also inhibited the increase in MDA levels and the reduction in SOD activity (P<0.05). Therefore, postconditioning with simvastatin was shown to attenuate myocardial injury. The underlying mechanism may be associated with the downregulation of HMGB1 expression in the ischemic myocardium.

Retigeric acid B-induced mitophagy by oxidative stress attenuates cell death against prostate cancer cells in vitro.

AIM: Retigeric acid B (RAB), a pentacyclic triterpenic acid from Lobaria kurokawae Yoshim, has been found to induce apoptosis in prostate cancer cells. The aim of this study was to investigate the roles of mitochondrial damage-caused mitophagy in RAB-induced prostate cancer cell death in vitro. METHODS: Human prostate cancer PC3 and LNCaP cells were tested. Cell viability was analyzed with MTT assay. Cell apoptosis, ROS level and mitochondrial transmembrane potential (mtΔψ) were measured with flow cytometry. Autophagy- and apoptosis-related proteins were studied using Western blotting. GFP-LC3B puncta, mitochondrial swelling and mitophagy were examined morphologically. Quantitative RT-PCR was used to measure LC3B mRNA level, and siRNA was used to knock down LC3BII. RESULTS: In both PC3 and LNCaP cells, RAB (15 µmol/L) increased ROS accumulation and decreased mtΔψ in a time-dependent manner. Furthermore, RAB induced mitochondrial swelling and mitophagy, significantly increased LC3B expression and conversion of LC3BI to LC3BII, and the elimination of mitochondria by LC3BII-containing autophagolysosomes. In addition, RAB suppressed the PI3K/Akt/mTOR pathway activation. Pretreatment of PC3 cells with autophagy inhibitor 3-MA (5 mmol/L) or the lysosomal protease inhibitor CQ (10 µmol/L) significantly increased RAB-induced apoptosis. Similar results were obtained in RAB-treated PC3 cells with LC3B knocked down. CONCLUSION: RAB induces mitochondrial damage and mitophagy that attenuates RAB-induced prostate cancer cell death. Thus, suppression of mitophagy might be a potential strategy for improving the chemotherapeutic effects of RAB.

Human leukocyte antigen-C and killer cell immunoglobulin-like receptor gene polymorphisms among patients with syphilis in a Chinese Han population.

Syphilis is a sexually transmitted infection caused by the Treponema pallidum subspecies pallidum spirochete bacterium. The killer cell immunoglobulin-like receptors (KIR), interacting with human leukocyte antigens (HLA), regulate the activations of natural killer (NK) cells and certain T-cell subsets in response to microbe infection. The objective of this study was to explore whether KIR and HLA-C gene polymorphisms were associated with syphilis in a Chinese Han population. Polymerase chain reaction with sequence-specific primers (PCR-SSP) method was used to genotype KIR and HLA-C genes in 231 syphilis patients and 247 healthy controls. Framework genes KIR2DL4, KIR3DL2, KIR3DL3 and KIR3DP1 were present in all individuals. The frequencies of KIR2DS3 and KIR3DS1 were higher in syphilis patients than in healthy controls (p = 0.030 and p = 0.038, respectively), while the frequency of KIR2DS5 was higher in healthy controls than in syphilis patients (p = 0.015; OR = 0.575). The homozygote for HLA-C1 allele (HLA-C1C1) was more common in controls compared with syphilis patients (p = 0.030; OR = 0.667). The frequency of individuals with HLA-C1C1 and KIR2DL3 genotype was higher in control group relative to syphilis patient group (p = 0.018; OR = 0.647). These data indicated that KIR2DS3 and KIR3DS1 were more prevalent in syphilis patients than in controls, and that KIR2DS5, HLA-C1C1 and HLA-C1C1-KIR2DL3 were more prevalent in controls than in syphilis patients, respectively. These will require further investigation using functional studies.

Preventive action of curcumin in experimental acute pancreatitis in mouse.

BACKGROUND & OBJECTIVES: Curcuma longa (turmeric) has a long history of use in Ayurvedic medicine as a treatment for inflammatory conditions. The purpose of the present study was to investigate the preventive effects of curcumin against acute pancreatitis (AP) induced by caerulein in mouse and to elucidate possible mechanism of curcumin action. METHODS: Curcumin (50 mg/kg/day) was intraperitoneally injected to Kun Ming male mice for 6 days, followed by injection of caerulein to induce AP. GW9662 (0.3 mg/kg), a specific peroxisome proliferator-activated receptor gamma (PPARγ) antagonist, was intravenously injected along with curcumin. Murine macrophage RAW264.7 cells were treated with 100 µmol/l curcumin for 2 h, and then stimulated with 0.1 µ g/ml lipopolysaccharide (LPS). Serum amylase and transaminase levels were measured at 10 h after AP. TNF-α level in mouse serum and cell culture medium were detected by ELISA. Expression of PPARγ and NF-κB were analyzed by RT-PCR and Western blot. RESULTS: Curcumin significantly decreased the pancreas injury and reversed the elevation of serum amylase, ALT and AST activities and TNF-α level in mice with AP. Curcumin treatment inhibited the elevation of NF-κB-p65 in the nucleus of mouse pancreas AP group and RAW264.7 cells, but significantly increased the expression of PPARγ. GW9662 could abolish the effects of curcumin on serum levels of amylase, ALT, AST, TNF-α, and NF-κB level. INTERPRETATION & CONCLUSIONS: Our results suggest that curcumin could attenuate pancreas tissue and other organ injury by inhibiting the release of inflammatory cytokine TNF-α. These effects may involve upregulation of PPARγ and subsequent downregulation of NF-κB.

Growth inhibition and induction of apoptosis in MCF-7 breast cancer cells by oridonin nanosuspension.

The mechanism for anti-tumor activity of oridonin (ORI) nanosuspension, prepared by the high pressure homogenization method, was studied using MCF-7 human breast carcinoma cells in vitro. MTT assay, observation of morphologic changes, flow cytometric analysis, and western blot analysis indicated that ORI nanosuspension could significantly intensify the in vitro anti-tumor activity to MCF-7 cells, as compared with ORI solution. Furthermore, ORI nanosuspension induced G2/M stage proliferation arrest and apoptosis in MCF-7 cells depending on its concentration. In addition, western blot analysis indicated that the pro-caspase-3 protein was not cleaved into the activated form and the expression of anti-apoptotic Bcl-2 protein decreased, on the contrary, the expression of pro-apoptotic Bax protein increased in a dose-dependent manner in ORI nanosuspension-treated cells. These observations indicated that the anti-tumor activity of ORI nanosuspension was intensified by cell-cycle arrest and apoptosis induction.

[Effects of 9-cis-retinoic acid on cell cycle and expression of cyclin D1 and cdk4 in lung cancer cells].

AIM: To study the effects of 9-cis-retinoic acid (9-cis-RA) on cell cycle and expression of cyclin D1 and cdk4 in lung cancer cells. METHODS: 9-cis-RA (1 x 10(-6) mol.L-1) was used to treat lung cancer cells for 24 h; Flow cytometry (FCM) was used to detect the percent of G0/G1 phase and S phase cells of three groups including blank control, DMSO control and 9-cis-RA groups; RT-PCR was used to analyze the expression changes of cyclin D1 and cdk4 before and after treatment with 9-cis-RA in lung cancer cells. RESULTS: The percent of G0/G1 phase cells of 9-cis-RA groups was significantly higher than that of the control groups (P < 0.01 or P < 0.05) and the percent of S phase cells of 9-cis-RA groups was lower than that of the control groups (P < 0.01 or P < 0.05); the expression of cyclin D1 of PG, SPC-A1 and L78 cells was decreased (P < 0.01) and the expression of cdk4 of PG, A549 and L78 cells was also decreased (P < 0.01) after treatment with 9-cis-RA. CONCLUSION: Most of the proliferation and the expression of cyclin D1 and cdk4 of PG, A549, SPC-A1 and L78 were inhibited by 9-cis-RA.

Conversion of an obligate autotrophic bacteria to heterotrophic growth: expression of a heterogeneous phosphofructokinase gene in the chemolithotroph Acidithiobacillus thiooxidans.

A plasmid pSDK-1 containing the Escherichia coli phosphofructokinase-1 gene (pfkA) was constructed, and transferred into Acidithiobacillus thiooxidans Tt-7 by conjugation. The pfkA gene from E. coli could be expressed in this obligately autotrophic bacterium but the enzyme activity (18 U g-1) was lower than that in E. coli (K12: 86 U g-1; DF1010 carrying plasmid pSDK-1: 97 U g-1). In the presence of glucose, the Tt-7 transconjugant consumed glucose leading to a better growth yield.

Clinical significance of plasma D-dimer and von Willebrand factor levels in patients with ulcer colitis.

AIM: To investigate the levels of D-dimer(DD) and von Willebrand factor(vWF) and the relationship between DD and vWF in ulcerative colitis(UC) patients. METHODS: A total of 29 plasma specimens were obtained from patients with ulcerative colitis (male 13, female 16) aged 21-47 years (33+/-11). Disease activity was assessed by Truelove-Writeria. Patients with a score of above 5 were regarded as having active colitis. Twenty healthy people(male 12, female 8) aged 19-53 years(31+/-14) served as normal controls. Blood samples were taken from an antecubital vein puncture. Blood(1.8 mL) was injected into the tubes containing sodium citrate (0.13 mmol/L). The plasma was obtained by centrifugation at 3000 r.min(-1) for 10 min, and stored at -80 degrees until assayed by ELISA. RESULTS: The mean plasma levels of DD and vWF in active UC patients were significantly higher than those of the controls (0.69+/-0.41 vs 0.27+/-0.11, P<0.01 143+/-46 vs 103+/-35, P<0.01). The mean plasma levels of DD in the patients with active disease were higher than those with inactive disease(0.69+/-0.41 vs 0.48+/-0.29 P<0.05). The levels of vWF were not different between active and inactive patients. DD levels were positively related to vWF levels( r =0.574, P<0.01). There was no significant difference between levels of DD and vWF and the scope of disease and sex of the patients. CONCLUSION: vWF is an important feature and a good marker of UC intravascular thrombus and endothelial cell dysfunction were found in UC patients and the combined test of DD and vWF is helpful to distinguish the activity of the UC patients.