Cloning and function analysis of high mobility group box 1(HMGB1)protein of Schistosoma japonicum(Mainland strain) / 中国血吸虫病防治杂志

Objective To clone and express a high mobility group box 1(HMGB1)protein of Schistosoma japonicum(Main-land strain)and analyze its function. Methods The DNA fragment of open reading frame encoding Sj HMGB1 protein was ampli-fied by RT-PCR from the mRNA of S. japonicum worms,then it was subcloned into the expression vector pET28a(+)to form the recombinant expression plasmid SjHMGB1-pET28a. The recombinant expression plasmid was transformed into the component E. coli BL21(DE3),and the tranformant containing recombinant expression plasmid was induced with IPTG to express the recombi-nant protein SjHMGB1. The recombinant SjHMGB1 protein was purified by affinity chromatography with nickel chelating affinity chromatography agarose gel. The Gel retard experiment and animal immunization were performed to analyze the DNA binding ca- pacity and the immunologic property of recombinant SjHMGB1. The expression levels of HMGB1 in different life cycle stages of S. japonicum were analyzed by Western bloting and RT-PCR. Female ICR mice were immunized with the recombinant SjHMGB1 pro-tein and infected with 45±2 cercariae of S. japonicum after three immunizations. Forty-two days post-infection,the worms and eggs of S. japonicum were recovered from the portal vein and liver tissue,respectively. The worm and egg reduction rates were calculat-ed respectively. Results A 530 bp of specific DNA fragment was amplified from mRNA of S. japonicum by RT-PCR,which was the open reading frame(ORF)encoding SjHMGB1protein confirmed by DNA sequencing analysis. The recombinant expression plasmid SjHMGB1-pET28a was constructed by cloning the ORF of SjHMGB1 into a expression vector pET28a(+). The bacterium transformants containing the recombinant plasmid expressed a soluble recombinant protein about 28 kDa after induced by IPTG, and the recombinant SjHMGB1 protein was purified by nickel chelating affinity chromatography. The gel retard experiment showed that the recombinant SjHMGB1 protein could bind to both supercoiled DNA and linear DNA,and the recombinant protein immu-nized mice produced high titers of antiserum IgG. Western bloting indicated that the recombinant SjHMGB1 protein was recognized specifically by the S. japonicum-infected mice serum. Above results showed that the recombinant SjHMGB1 protein possessed both functional activity and immunogenicity as the natural protein. RT-PCR and Western blot results showed that SjHMGB1 was abun-dantly expressed in the adult and egg stages whereas barely detectable in the cercaria stage. The immune protection experiment showed that the recombinant SjHMGB1 induced mice to produce high titers of specific antibody IgG but failed to conduct an effec-tive immune protection against S. japonicum. Conclusion The gene encoding HMGB1 from S. japonicum and the soluble recombi-nant SjHMGB1 protein with natural functional activity are obtained,and the recombinant SjHMGB1 has a high immunogenicity but is not able to induce an effective immune protection against S. japonicum.

Effect of nimodipine on DNA-binding activity of cAMP response element binding protein and CCAAT enhancer binding protein in hippocampus in vascular dementia rats / 中华行为医学与脑科学杂志

ObjectiveTo observe the effect of nimodipine on hippocampal DNA-binding activity change of cAMP response element binding protein ( CREB )and CCAAT enhancer binding protein (C/EBP) in a rat model of vascular dementia(VD),and to explore the treatment mechanism of nimodipine.Methods66 healthy adult male SD rats were assigned to the following three groups of 22 each:VD model group,Sham-operated group,Nimodipine group.VD rat model was prepared by four-vessel occlusion.Physiological saline solution( 8 ml · kg-1 · d-1 )and Nimodipine (20 mg· kg-1 · d-1 )were administered by gavage respectively.The Morris maze was adopted to detect the changes of spatial learning and memorizing capacity,while HE straining was adopted to observe the changes of pathological characteristics in hippocampal CA1 area,and electrophoretic mobility shift assay(EMSA) were adopted to observe DNA-binding activity changes of CREB and C/EBP in hippocampus tissue.ResultsThe Morris maze showed:the learning and memory ability of nimodipine group rats ( escape latency period ( 26.63 ± 1.31 )s,the times of cross-platform(7.25 ±0.92) times) was higher than that of VD model group(escape latency period (41.25 ± 1.83 ) s,the times of cross-platform ( 5.33 ± 0.64 ) times ),with difference of statistical significance (P ＜0.05).HE results:in VD model group,neurons in CA1 were scaltered and boundaries were unclear,nuclei region was stained,coagulation necrosis appeared,obviously cells lost.The CA1 neurons of nimodipine group returned to be normal,nuclear membrane's profile and nudeolus were clear,regularly arranged; the number of hippocampal normal neurons in nimodipine group (43.19 ± 2.87 ) was more than that of VD model group( 16.33 ± 1.09 ),with difference of statistical significance(P＜0.05 ).EMSA:both CREB and C/EBP DNA-binding activity in rat hippocampus of nimodipine group ( ( 369.75 ± 13.22 ),( 428.25 ± 17.69 ) respectively ) were higher than those of VD model group ( ( 142.25 ± 27.86 ),(97.00 ± 5.88 ),respectively),with difference of statistical significance (P ＜0.01 )).ConclusionNimodipine can improve VD rats hippocampal neuronal injuries and their learning and memory impairment may be involved in the upregulating CREB and C/EBP DNA-binding activity.

The Regulation of AP-1 DNA Binding Activity by Long-term Nicotine Stimulation in Bovine Adrenal Medullary Chromaffin Cells: Role of Second Messengers

The signal pathways involved in the regulation of AP-1 DNA binding activity in long-term nicotine stimulated bovine adrenal medullary chromaffin (BAMC) cells have not been well characterized. To understand the involvement of second messengers in the regulation of AP-1 DNA binding activity, the present study was designed to define the time-course for inhibition of nicotine-induced responses by cholinergic antagonists, Ca2+ and calmodulin (CaM) antagonists, and calcium/calmodulin-dependent protein kinase (CaMK) II inhibitor using electrophoretic mobility shift assay. Nicotine (10microM) stimulation increased AP-1 DNA binding activity at 24 hr after treatment. Posttreatment with hexamethonium (1 mM) plus atropine (1microM) (HA), nimodipine (1microM), or calmidazolium (1microM) at 0.5, 3, and 6 hr after the nicotine treatment significantly inhibited the AP-1 DNA binding activity increased by long-term nicotine stimulation. However, posttreatment with HA, nimodipine, or calmidazolium at 9 or 12 hr after the nicotine treatment did not affect the nicotine-induced increase of AP-1 DNA binding activity. The pretreatment of BAMC cells with various concentrations of KN-62 inhibited the increase of AP-1 DNA binding activity induced by nicotine in a concentration-dependent manner. KN-62 (10microM) posttreatment beginning at 0.5, 3, or 6 hr after the nicotine treatment significantly inhibited the increase of AP-1 DNA binding activity. However, KN-62 posttreatment beginning at 9 or 12 hr after the nicotine treatment did not affect the increase of AP-1 DNA binding activity. This study suggested that stimulation (for at least 6 hr) of nicotinic receptors on BAMC cells was necessary for increase of AP-1 DNA binding activity, and activation of Ca2+, CaM, and CaMK II up to 6 hr at least seemed to be required for the increase of nicotine-induced AP-1 DNA binding activity.

A radioimmunoassay method for detection of DNA based on chemical immobilization of anti-DNA antibody

High selectivity provided by biomolecules such as antibodies and enzymes has been exploited during the last two decades for development of biosensors. Of particular importance are efficient immobilization methods for biomolecules in order to preserve their biological activities. In this study, we have evaluated immobilization strategies for an anti-DNA antibody on a self-assembled monolayer of omega-functionalized thiols. The antibody was immobilized via peptide bond formation between the primary amines in the antibody and the carboxyl groups on the self-assembled monolayer. The peptide bond coupling was achieved by activating COOH groups on the surface through N-Hydroxysuccimide (NHS)-ester formation, followed by acylation of NH2 group in the antibody. DNA binding activity of the immobilized antibody was examined by counting beta emission from 35S-labeled DNA.

Role of nuciear factor-?B in the ischemic acute renal failure rat / 中华肾脏病杂志

Objective To determine the role of nuclear factor-?B(NF-?B) in ischemic acute renal failure (ARF) rats. Methods Gel mobility shift assay was used to detect the DNA binding activity of NF-KB in ischemic ARF rats and reverse transcription-polymerase chain reaction (RT-PCR) assay was used to study the expression of renal inducible nitric oxide synthase (iNOS) . The relationship between DNA binding activity of NF-?B and expression of iNOS was also analyzed. Results The DNA binding activity of NF-?B in renal cortex increased from 1.00 ?0.17 of controls to 3. 67 ? 1. 94 of 6 hours after ischemia-reperfusion ( P