Acacetin protects against cerebral ischemia-reperfusion injury via the NLRP3 signaling pathway

Acacetin (5,7-dihydroxy-4'-methoxyflavone), a potential neuroprotective agent, has an inhibitory effect on lipopolysaccharide-induced neuroinflammatory reactions. However, whether acacetin has an effect on inflammatory corpuscle 3 (NLRP3) after cerebral ischemia-reperfusion injury has not been fully determined. This study used an improved suture method to establish a cerebral ischemia-reperfusion injury model in C57BL/6 mice. After ischemia with middle cerebral artery occlusion for 1 hour, reperfusion with intraperitoneal injection of 25 mg/kg of acacetin (acacetin group) or an equal volume of saline (0.1 mL/10 g, middle cerebral artery occlusion group) was used to investigate the effect of acacetin on cerebral ischemia-reperfusion injury. Infarct volume and neurological function scores were determined by 2,3,5-triphenyltetrazolium chloride staining and the Zea-Longa scoring method. Compared with the middle cerebral artery occlusion group, neurological function scores and cerebral infarction volumes were significantly reduced in the acacetin group. To understand the effect of acacetin on microglia-mediated inflammatory response after cerebral ischemia-reperfusion injury, immunohistochemistry for the microglia marker calcium adapter protein ionized calcium-binding adaptor molecule 1 (Iba1) was examined in the hippocampus of ischemic brain tissue. In addition, tumor necrosis factor-α, interleukin-1β, and interleukin-6 expression in ischemic brain tissue of mice was quantified by enzyme-linked immunosorbent assay. Expression of Iba1, tumor necrosis factor-α, interleukin-1β and interleukin-6 was significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Western blot assay results showed that expression of Toll-like receptor 4, nuclear factor kappa B, NLRP3, procaspase-1, caspase-1, pro-interleukin-1β, and interleukin-1β were significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Our findings indicate that acacetin has a protective effect on cerebral ischemia-reperfusion injury, and its mechanism of action is associated with inhibition of microglia-mediated inflammation and the NLRP3 signaling pathway.

MicroRNA-126-3p suppresses cell proliferation by targeting PIK3R2 in Kaposi's sarcoma cells

Kaposi's sarcoma is a highly vascular tumor of lymphatic endothelial origin. Many deregulated miRNAs, including miR-126-3p, have been identified in Kaposi's sarcoma tissues. miR-126-3p is the most highly endothelial-specific miRNA that regulates vascular integrity and angiogenesis. In this study, we aimed to determine the effect of miR-126-3p on Kaposi's sarcoma cells through transfection of a miRNA mimic and inhibitor. Moreover, we searched the target gene (PIK3R2) of miR-126-3p using bioinformatics software and further verified PIK3R2 using luciferase reporter assays, Real-time quantitative PCR (qRT-PCR) and western blot. The results demonstrated that miR-126-3p inhibited cell proliferation, arrested cell cycle progression, induced cell apoptosis, and inhibited cell invasion of SLK cells. The bioinformatics analysis and luciferase reporter assay revealed that PIK3R2 mRNA is a direct target of miR-126-3p. Moreover, the level of expression of the PIK3R2 gene was downregulated in SLK cells transfected with miR-126-3p siRNAs. Therefore, our data demonstrated that miR-126-3p is a tumor suppressor miRNA that acts by targeting PIK3R2 in Kaposi's sarcoma cells. These findings contribute to our understanding of the molecular mechanisms underlying Kaposi's sarcoma.

[Inhibitory effect of imrecoxib combined with lobaplatin on tumor growth and lymph node metastasis of human lung cancer xenografts in nude mice]

OBJECTIVE

To evaluate the inhibitory effect of imrecoxib combined with lobaplatin on tumor growth and lymph node metastasis of human lung adenocarcinoma xenografts in nude mice, and to explore its possible mechanisms.

METHODS

Human lung cancer A549 cells were injected into Bal B/c nude mice subcutaneously. Twenty-eight healthy male nude mice were randomly divided into 4 groups: the control group, imrecoxib group, lobaplatin group and imrecoxib combined with lobaplatin group. Each group was treated with appropriate drugs and the tumor size was measured every five days. The expression of ezrin and E-cadherin protein was detected by immunohistochemistry and flow cytometry. Ezrin and E-cadherin mRNA were detected by real-time PCR.

RESULTS

The tumor inhibition rates of imrecoxib group, lobaplatin group and combination group were 36.7%, 54.6% and 69.2%, respectively. The tumor volumes of imrecoxib group [(905.33±113.31) mm(3)] and combination group [(507.74±77.50) mm(3)] were significantly lower than that of the control group (1355.33±189.04) mm(3) (P<0.05), and the tumor weights were significantly reduced [(1.13±0.14) g, (0.63±0.10) g respectively] vs. (1.69±0.24) g (P<0.05). The expressions of ezrin protein and mRNA in the imrecoxib group and combined treatment group were significantly lower than that of the control group (136.53±35.52, 74.72±19.48 vs. 175.62±21.16 for protein expression level; 0.54±0.03, 0.36±0.03 vs. 1.02±0.02 for mRNA expression level, respectively, P<0.05 for both), while the expression of E-cadherin protein and mRNA in the imrecoxib group and combined treatment group was significantly higher than that of the control group (253.78±38.87, 308.94±24.67 vs. 213.66±30.31 for protein expression level; 2.19±0.02, 3.02±0.02 vs. 1.05±0.03 for mRNA expression level, respectively, P<0.05 for both). There was a significant negative correlation between ezrin protein and E-cadherin protein (r=-0.737, P<0.01), as well as between ezrin mRNA and E-cadherin mRNA (r=-0.977, P<0.01).

CONCLUSIONS

Administration of imrecoxib combined with lobaphatin has inhibitory effects on the growth of non-small cell lung cancer xenografts and lymph node metastasis via down-regulated ezrin and upregulated E-cadherin. Imrecoxib and lobaplatin have a synergistic antitumor effect.

[Cloning and expression of the genes of glutathione synthetases]

The genes(gsh-I,gsh-II) for gamma-glutamyl-cysteine synthetase(GSH-I) and glutathione synthetase(GSH-II) from Escherichia coli B were amplified by PCR and then subcloned into plasmid pUC19 respectively. The DNA fragments harboring gshII and gsh I were inserted into plasmid pTrc99A one by one to get a hybrid plasmid pTrc-gsh. E. coli BL21 was transformed by pTrc-gsh for expression of the related enzymes. Analysis of SDS-PAGE showed that the expected products were expressed. E. coli BL21(pTrc-gsh) were incubated at 37 degrees C and pH 7.2 to OD550 = 0.5. The conditions were then switched to 34 degrees C and pH6.7 after the addition of 0.1 mmol/L IPTG. The expressed products were up to 25% of the total protein of the bacteria. Acetone-treated cells of the engineered strain could synthesize GSH efficiently.

Tapeworm infection resulting from pork eaten at a wedding banquet

Forty-five people who had attended a wedding banquet were examined by means of both Avidin-Biotin Peroxidase Complex-ELISA (ABC-ELISA) and Kato stool thick smear technic. The results revealed that the positive rates with ABC-ELISA were 15.56% (7/45) and Kato Katz 0.62% (1/161). There was a significant difference between the two positive rates (p < 0.005). Six people at the wedding had taeniasis and 4 of them also had cysticercosis. Local people have no habit of eating uncooked pork, but at this banquet the meat from an infected cysticerci pig was used for preparing dishes for the wedding feast and the cold dishes were contaminated by the bladder worms as the result of using the same chopping block.

A study on the culture medium antigens of Cystcercus cellulosae for detecting antibodies of cysticercosis by means of ABC-ELISA

Two antigens of Cysticercus cellulosae, cystic fluid antigen (CFA) and the culture medium antigen (CMA), were used in Avidin-Biotin Peroxdase Complex-ELISA (ABC-ELISA) to detect IgG antibodies in 45 cases of cysticercosis treated with praziquantel. The results revealed the total positive rates as 51.11% with CMA and 82.22% with CFA. The positive rates in the cases treated within 2 courses of treatment were 79.17% for CMA and 87.50% for CFA, and only 19.05% for CMA and 71.43% for CFA in the cases treated for more then 3 courses. The fact that the positive rates decreased as the courses of treatment increased showed that the sensitivity of CMA might be related to the vital conditions of the worms in the body, whether alive or dead. It is, therefore, recommended that CMA has the potential to be employed in ABC-ELISA both as an indicator for diagnosing cysticercosis and as a reference for the evaluation of the treatment.

Observations on the effects of cysticercosis immune sera on cysticercosis by scanning electronmicroscopy

Two antigens of Taenia solium cysticercus, cystic fluid antigen (CFA) and the culture medium antigen (CMA), were used respectively to immunize rabbits in order to obtain immunosera. The CMA immunoserum added to culture medium with cysticerci limited the activities of the bladder worms. By using the scanning electronmicroscope, we could observe particulate deposits on the surface of the scolices, suckers and necks of the worms. The CFA immunoserum group showed similar changes but the deposit was less than that on the worms in the former group and appeared mainly on the cystic wall. After adding complement to the two groups mentioned above, we found that the microcilia on the surface of the worms were swollen and were seriously damaged. The worms treated with praziquantel were damaged over large area of their surfaces and were affected deep into their tissues. The damaged parts of the worms were quite different between the two groups. CMA is secreted by the living worms and therefore the serum antibodies are more effective than CFA in anti-parasite activity.

Single-sweep polarographic investigation of concanavalin A and its interaction with polysaccharide

A simple, rapid, and sensitive single-sweep polarographic method has been developed for investigation of concanavalin A (con A) and its interaction with selected polysaccharides. In a solution containing 0.001 M 2,2'-bipyridine, 0.015 M hexamethylenetetramine, and 0.1 M sodium chloride, con A exhibits a single-sweep polarographic wave, and the cathodic peak potential is -1.50 V (vs SCE). The peak current varies linearly with con A concentration over a range of 1.0 x 10(-8) to 1.2 x 10(-7) M by derivative single sweep polarography. A preliminary discussion on properties of the con A polarographic wave has been made. In addition, it has been demonstrated that single sweep polarography can be a useful method for studies on interactions of con A with its complementary polysaccharides in solution.

Single-sweep polarography of the copper(II)-3-hydroxy-1-p-sulphonatophenyl-3-phenyltriazene complex and its analytical applications

A polarographic investigation of the copper-3-hydroxy-1-p-sulphonatophenyl-3-phenyltriazene (HSPT) complex in 0.05 M sodium tetraborate medium is described and a simple and sensitive single-sweep polarographic method for the determination of trace amounts of copper in biological samples is proposed. The complex was shown to be Cu(HSPT)2 with log beta' = 11.38. The polarographic wave is caused by the reduction of copper(II) in the adsorbed complex to copper amalgam on the surface of a mercury electrode. The current peak is directly proportional to the concentration of copper in the range 8.0 x 10(-9)-4.0 x 10(-6) M and the detection limit is 5.0 x 10(-9) M.