Anti-Hypertensive Action of Fenofibrate via UCP2 Upregulation Mediated by PPAR Activation in Baroreflex Afferent Pathway / 神经科学通报·英文版

Fenofibrate, an agonist for peroxisome proliferator-activated receptor alpha (PPAR-α), lowers blood pressure, but whether this action is mediated via baroreflex afferents has not been elucidated. In this study, the distribution of PPAR-α and PPAR-γ was assessed in the nodose ganglion (NG) and the nucleus of the solitary tract (NTS). Hypertension induced by drinking high fructose (HFD) was reduced, along with complete restoration of impaired baroreceptor sensitivity, by chronic treatment with fenofibrate. The molecular data also showed that both PPAR-α and PPAR-γ were dramatically up-regulated in the NG and NTS of the HFD group. Expression of the downstream signaling molecule of PPAR-α, the mitochondrial uncoupling protein 2 (UCP2), was up-regulated in the baroreflex afferent pathway under similar experimental conditions, along with amelioration of reduced superoxide dismutase activity and increased superoxide in HFD rats. These results suggest that chronic treatment with fenofibrate plays a crucial role in the neural control of blood pressure by improving baroreflex afferent function due at least partially to PPAR-mediated up-regulation of UCP2 expression and reduction of oxidative stress.

Immunoprotective effect of combined pneumococcal endopeptidase O and pneumococcal surface adhesin A vaccines against Streptococcus pneumoniae infection / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the prokaryotic expression of proteins pneumococcal endopeptidase O (PepO) and pneumococcal surface adhesin A (PsaA) in Streptococcus pneumoniae and their immunoprotective effect as vaccine candidate proteins.</p><p><b>METHODS</b>Specific primers of target gene fragments were designed, and then PCR amplification was performed to establish recombinant plasmids pET28a(+)-pepO and pET28a(+)-psaA, which were transformed into host cells, Escherichia coli BL21 and DE3, respectively, to induce expression. Highly purified target proteins PepO and PsaA were obtained after purification. Mucosal immunization was performed for BALB/c mice and specific antiserum was prepared. ELISA was used to measure the antibody titer, and Western blot was used to analyze the specificity of the antiserum of target proteins. The mice were randomly divided into negative control group, PepO group, PsaA group, and PepO+PsaA combined immunization group, with 18 mice in each group. The models of different serotypes of Streptococcus pneumoniae infection were established to evaluate the immunoprotective effect of target proteins used alone or in combination.</p><p><b>RESULTS</b>The target proteins PepO and PsaA were successfully obtained and Western blot demonstrated that the antiserum of these proteins had good specificity. There was no significant difference in the titers of IgA in saliva and IgG in serum between the PepO group and the combined immunization group (P>0.05); however, these two groups had significantly higher antibody titers than the PsaA group (P<0.05). The PepO, PsaA, and combined immunization groups had significantly higher protection rates for mice infected with Streptococcus pneumoniae D39 and CMCC31436 in the nasal cavity than the negative control group (P<0.05). The PepO and combined immunization groups had a significantly higher protection rate for mice infected with Streptococcus pneumoniae D39 than the PsaA group (P<0.05). The results of colonization experiment showed that compared with the control group, the PepO, PsaA, and combined immunization groups showed a significant reduction in the colonization of Streptococcus pneumoniae (CMCC31693 and CMCC31207) in the nasopharynx and lung (P<0.05). The combined immunization group showed a better effect on reducing the colonization of CMCC31207 in the lung than the PepO and PsaA alone groups.</p><p><b>CONCLUSIONS</b>Combined PepO/PsaA vaccines may produce a better protective effect by mucosal immunization compared with the vaccine used alone in mice. The combined vaccines can effectively reduce the colonization of Streptococcus pneumoniae in the nasopharynx and lung. Therefore, such protein vaccines may have a great potential for research and development.</p>

Amino-terminal pro-brain natriuretic peptide and brain natriuretic peptide measurements under various detection conditions in patients with chronic heart failure / 中华心血管病杂志

<p><b>OBJECTIVE</b>To find the potential interference factors for the detection of NT-proBNP and BNP in patients with chronic heart failure.</p><p><b>METHODS</b>EP15-A2 issued by Clinical and Laboratory Standards Institute (CLSI) was employed to compare the precision and accuracy of commercial NT-proBNP and BNP analyzer electrochemiluminescence immunoassay system Cobas E601 and chemiluminescence system ADVIA Centaur. Moreover, NT-proBNP and BNP were detected in different time interval and in different interfered sampling conditions (haematolysis, choloplania, lipemia). NT-proBNP and BNP of 203 patients with heart failure or heart failure complicated with acute cerebral infarction were analyzed to find the deviation caused by patients' endogenous factors.</p><p><b>RESULTS</b>The precision and accuracy were comparable for NT-proBNP and BNP detection using Cobas E601 and ADVIA Centaur (total-CV below 2.9% and 3.5%, the deviation from definite value below 2.38% and 3.91%). The most suitable sample type for NT-proBNP and BNP detection was serum and EDTA-anticoagulant plasma. The detection results of NT-proBNP and BNP were comparable for at least 120 min post sampling and not affected by Hb (2 g/L), DB (428 µmol/L) and chyle (2000 FIU). NT-proBNP was significantly higher in heart failure patients complicated with cerebral infarction (P = 0.003) than in heart failure patients. BNP was significantly higher in heart failure grade III patients complicated with cerebral infarction (P < 0.01).</p><p><b>CONCLUSIONS</b>Cobas E601 and ADVIA Centaur supplied satisfactory detection of NT-proBNP and BNP in patients with chronic heart failure with strong anti-interference capacity. The diagnostic value of NT-proBNP and BNP for chronic heart failure should be analyzed objectively in the presence of complicating diseases.</p>

Effect of selenium on apoptosis of spleen ceils, T-cell subset of fluorosis chicken / 中国地方病学杂志

Objective To study the effect of selenium on peripheral and splentic T-cell subset, apoptosis of spleen cells in fluorosis chicken and its mechanism. Methods One hundred and eighty 8-day Hailanhe chicks were randomly divided into 3 groups(each 60): ①control group: 195 mg/kg fluoride and 0.08 mg/kg of selenium; ②fluorine group : 1000 mg/kg fluoride and 0.08 mg/kg of selenium ;③selenium antagonism group : 1000 mg/kg On 30~(th), 60~(th), 90~(th) day, peripheral and splentic CD4~+, CD8~+ T-cell subset analyses underwent flow cytometry and apoptosis of spleen cells were detected by TUNEL for study subjects. Results Compared with control group, the CD4~+ T-cell subset of peripheral in fluorine group was decreased obviously in 30,60,90 days[ (35.36± 4.27)% vs (24.29 ± 2.96)%, (47.65 ± 5.42)% vs (41.62 ± 3.96)%, (49.58 ± 3.98) % vs (42.35 ± 6.03 )%, P < 0.05 or < 0.01 ], CD4~+/CD8~+ ratio also was decreased obviously [ ( 1.701 ± 0.145 )% vs (1.393 ± 0.163)%,(2.712 ± 0.345)% vs (1.781 ± 0.201)%,(2.438 ± 0.356)% vs (1.973 ± 0.229)%, P< 0.05 or < 0.01]. Compared with fluorine group, the CD4~+ T-cell subset of peripheral in selenium antagonism group [ (29.40 ± 3.38)%, (45.40 ± 6.01 )%, (46.85 ± 5.25)%, P < 0.05 or < 0.01 ] was increased obviously in 30,60,90 days,CD4~+/CD8~+ ratio in 60,90 days[(2.004 ±0.314)%,(2.211±0.229)%,all P<0.01]also was increased obviously.Compared with control group,the CD4~+ T-cell subset of spleen cells in fluorine group was decreased obviously in 30,60,90 days[(47.33±5.35)% vs(41.91±4.83)%,(49.28±5.24)% vs(41.26 ±4.56)%,(34.31±4.15)%vs(29.33±2.89)%,all P<0.01],CD4~+/CD8~+ ratio also was decreased obviously[(1.927 ±0.244)% vs(1.525 ±0.265)%,(1.847±0.224)% vs(1.640±0.198)%.(1.265±0.174)% vs(0.878±0.092)%,P<0.05 or<0.01].Compared with fluorine group,the CD4~+ T-cell subset of spleen cells in selenium antagonism group in 60,90 days[(44.87±5.43)%,(32.62±3.37)%,all P<0.05]was increased obviously,CD4~+/CD8~+ ratio in 30,60, 90 days[(1.703 ±0.201)%,(1.772±0.215)%,(0.991±0.124)%,P<0.05 or<0.01]also was increased obviously. The apoptosis ratio of spleen cells in fluorine group in 30,60,90 days[(2.31±0.36)%,(2.76±0.22)%,(3.04± 0.29)%]was higher than that in control group[(1.14±0.21)%,(1.23±0.23)%,(1.29±0.20)%,P<0.01].The apoptosis ratio of spleen cells in selenium antagonism group in 60,90 days[(2.42 ±0.32)%,(2.73±0.39)%]was lower than that in fluorine group(P<0.05 or<0.01).Conclusion A certain concentration of selenium can antagonize the immunity inhibition of fluorine by decreasing apoptosis and improving the unbalance of T-cell subset.

Effect of ClpE depletion on the bacterial protein expression profiles of Streptococcus pneumoniae / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of ClpE on the protein expression profiles of Streptococcus pneumoniae.</p><p><b>METHODS</b>clpE-deficient Streptococcus pneumoniae strain was constructed by long flanking homology-polymerase chain reaction (LFH-PCR) and identified by PCR and sequencing. The total bacterial proteins were analyzed by two-dimensional gel electrophoresis and imaging analysis, and the differentially expressed protein spots were excised by dot-gel digestion with trypsin. Peptide mass fingerprinting (PMF) was obtained by analysis of the fragment length by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The PMF was analyzed using software to identify the proteins.</p><p><b>RESULTS</b>The number of matched protein spots of the two gels was 61%. By sequence database searching, 4 out of the 17 differential protein spots were identified, namely hypoxanthine-guanine, pyrrolidone-carboxylate peptidase1, formate-tetrahydrofolate ligase, and bifunctional protein pyrR.</p><p><b>CONCLUSION</b>clpE gene-deficient Streptococcus pneumoniae expresses fewer kinds of proteins at also lower levels than the wild-type bacteria, suggesting that ClpE allows the bacteria to adapt to different host environments by inducing the expression of special proteins.</p>

Cloning the coding cDNA sequence of alpha1, beta2 and gamma2 subunit of GABA-A receptor in American king pigeon / 中国应用生理学杂志

<p><b>AIM</b>To clone and analyse the coding cDNA sequence of alpha1, beta2 and gamma2 subunit of GABAA receptor in American king Pigeon.</p><p><b>METHODS</b>Withdrew total RNA from the American king pigeon brain, reverse transcribing general primers to acquire a gene set cDNA. Designing specific primers of three subunit mRNA of the GABAA receptor, by RT-PCR respectively expanded the conservative gene of al subunit, beta2 subunit and gamma2 subunit of GABAA receptor, and carried on clone, plastid identification and the sequence measurese of three genes.</p><p><b>RESULTS</b>The experiment on sequence measures has succeeded that sequence analysis indicated that lengths of the conservative gene of alpha1 subunit, beta2 subunit and gamma2 subunit of GABAA receptor was respectively 899 bp, 597 bp and 563 bp, homology on reference sequence was respectively 94.99%, 94.64% and 96.28%.</p><p><b>CONCLUSION</b>Homology is high on the conservative gene of alpha1 subunit, beta2 subunit and gamma2 subunit of GABAA receptor of brain tissue of pigeon and chicken but there is a discriminating characteristic in different kinds of animals.</p>

Preparation of metal chelate affinity chromatographic medium and its application in the purification of 6 x histidine-tagged protein / 生物工程学报

Using Sepharose CL-6B as support, 3-Chloro-1, 2-epoxypropane as activated agent, carboxymethylated aspartate (CM-Asp) as chelating ligand, A chelate affinity chromatographic medium based on Co2+, named Co-CM-Asp-Sepharose, was prepared and used to purify 6 x His-tagged fusion proteins. The amount of Co-CM-Asp-Sepharose reacted with 200 microL of lysate, the incubation time, wash condition and the imidazole concentration in the elution buffer were optimized. The purification results using Co-CM-Asp-Sepharose and Ni-NTA-Agarose (product of Qiagen) were compared. The CD155D1 fusion protein was also purified from 5mL of lysate and the amount of protein was determined by Bradford method. The results show that 60 microL of Co-CM-Asp-Sepharose (50% suspension) was suitable for the protein purification from 200 microL of lysate, the optimal incubation time of medium and lysate was 30 min, the optimal imidazole concentration in the eluting buffer was 200 mmol/L, and 200 microg of fusion protein was obtained. In a big scale experiment, 4.6 mg of fusion protein was obtained from 5 mL of lysate using 1.5 mL of Co-CM-Asp-Sepharose (50% suspension). Compared with Ni-NTA-Agarose, the Co-CM-Asp-Sepharose medium exhibits higher selectivity and the protein possesses higher purity.