Interaction of hepatitis C virus envelope glycoprotein E2 with the large extracellular loop of tupaia CD81

AIM: To further analyze the interaction of tupaia CD81 with hepatitis C virus (HCV) envelope protein E2. METHODS: A tupaia CD81 large extracellular loop (CD81 LEL), which binds to HCV E2 protein, was cloned and expressed as a GST-fusion protein, and interaction of HCV E2 protein with a tupaia CD81 LEL was evaluated by enzyme-linked immunosorbent assay (EIA). RESULTS: Although tupaia and human CD81 LEL differed in 6 amino acid changes, tupaia CD81 LEL was strongly recognized by anti-CD81 antibodies against human CD81 LEL conformation-dependent epitopes. Investigating LEL CD81-E2 interactions by EIA, we demonstrated that binding of tupaia CD81 LEL GST fusion protein to recombinant HCV E2 protein was markedly reduced compared to binding of human CD81 LEL GST fusion protein to recombinant HCV E2 protein. CONCLUSION: These data suggest that the structural differences in-between the tupaia and human CD81 may alter the interaction of the large extracellular loop with HCV envelope glycoprotein E2. These findings may be important for the understanding of the mechanisms of binding and entry of HCV to PTHs.

SATB2-associated syndrome caused by a novel SATB2 mutation in a Chinese boy:A case report and literature review

BACKGROUND Special AT-rich sequence binding protein 2(SATB2)-associated syndrome(SAS;OMIM 612313)is an autosomal dominant disorder.Alterations in the SATB2 gene have been identified as causative.CASE SUMMARY We report a case of a 13-year-old Chinese boy with lifelong global developmental delay,speech and language delay,and intellectual disabilities.He had short stature and irregular dentition,but no other abnormal clinical findings.A de novo heterozygous nonsense point mutation was detected by genetic analysis in exon 6 of SATB2,c.687C>A(p.Y229X)(NCBI reference sequence:NM_001172509.2),and neither of his parents had the mutation.This mutation is the first reported and was evaluated as pathogenic according to the guidelines from the American College of Medical Genetics and Genomics.SAS was diagnosed,and special education performed.Our report of a SAS case in China caused by a SATB2 mutation expanded the genotype options for the disease.The heterogeneous manifestations can be induced by complicated pathogenic involvements and functions of SATB2 from reviewed literatures:(1)SATB2 haploinsufficiency;(2)the interference of truncated SATB2 protein to wild-type SATB2;and(3)different numerous genes regulated by SATB2 in brain and skeletal development in different developmental stages.CONCLUSION Global developmental delays are usually the initial presentations,and the diagnosis was challenging before other presentations occurred.Regular follow-up and genetic analysis can help to diagnose SAS early.Verification for genes affected by SATB2 mutations for heterogeneous manifestations may help to clarify the possible pathogenesis of SAS in the future.

CD2AP、F-actin在肾病大鼠中的表达及意义

目的:观察CD2-associatedprotein(CD2AP)、肌动蛋白微丝(F-actin)在氨基核苷肾病大鼠肾小球中的表达变化及其意义。方法:通过建立大鼠氨基核苷肾病模型,采用免疫组织化学、蛋白质印迹技术观察CD2AP在不同时点肾病大鼠肾小球中的表达和分布变化,采用荧光技术检测肾小球F-actin含量的变化。结果:①肾小球足细胞CD2AP的表达在肾病模型建立的早期即有下调;在肾病大鼠蛋白尿的高峰期,CD2AP的表达明显下降(P<0.01);在肾病大鼠的疾病恢复期,CD2AP的表达逐步恢复正常。②肾小球足细胞CD2AP表达量的变化与肾病大鼠24h尿蛋白的变化呈负相关(r=-0.865,P<0.01)。③在肾病大鼠蛋白尿的高峰期,肾小球F-actin含量明显下降(P<0.05)。④肾小球CD2AP蛋白表达量和肾小球F-actin荧光定量变化呈正相关(r=0.873,P<0.01)。结论:①CD2AP、F-actin的表达变化在蛋白尿的发生机制中有着重要作用。②CD2AP可能是判断肾小球足细胞损伤的一个早期重要指标。

绵羊Txl-2基因CDS区克隆及其生物信息学分析

本研究以绵羊睾丸组织为材料,利用RT-PCR技术获得绵羊硫氧还蛋白类蛋白2(Thioredoxin like protein 2,Txl-2)基因的CDS区序列,并对其进行生物信息学分析。结果表明,克隆得到的绵羊Txl-2基因CDS区为795 bp,编码264个氨基酸。生物信息学分析结果表明,Txl-2编码的蛋白无跨膜区、信号肽和N-糖基化位点,存在多个磷酸化位点;预测出了Txl-2蛋白的二级结构和三级结构;Clustel W方法对比绵羊Txl-2与绵羊、山羊预测序列同源性最高。

丝胶蛋白的固定化及其对Cd^2＋的吸附效果研究

通过固定化载体和制备方法的选择,以对Cd^(2+)的吸附量为考察指标,得到了固定化丝胶蛋白的最佳制备条件。结果表明,以壳聚糖为载体,采用包埋—交联法,在壳聚糖质量浓度为20g/L、煮茧废水与壳聚糖溶液体积比为1∶1、戊二醛体积分数为2%的条件下,制备的壳聚糖固定化丝胶蛋白成球效果好、易操作、机械强度适中,对Cd^(2+)的吸附量最大达到102.72mg/g。

IN VITRO CO-STIMULATORY ACTIVITY OF HUMAN B7.2(IgV+C) PROTEIN PRODUCED BY ENGINEERED BACTERIA

Objective To express human B7. 2 extracellular domain with prokaryote expression system and to evaluate its biological activity in vitro. Methods PCR was used to amplify the extracellular region of human B7. 2 which contained both the IgV and IgC domains. The recombinant PGEX-4T-3/hB7. 2 (IgV+C) was obtained by cloning the PCR product into a prokaryote expression plasmid PGEX-4T-3 and was transformed into the host strain of DH5-a. Tke fusion protein consisted of GST and hB7. 2(IgV+C) was identified by SDS-PAGE and Western blotting. T cell activation was observed by exposing purified T lymphocytes to the fusion protein and [3H]-TdR incorporation with the presence of the first signal imitated hy anti-CD3 antibody. Results The fusion protein GST-hB7. 2 (IgV+ C) was produced and detected in inclusive body form from engineered bacterial cells. With the first signal existed,T lymphocytes proliferated when it was co-stimulated by the fusion protein. Conclusion These results indicated that the functional human B7. 2(IgV+C) fusion protein can be produced in bacterial cells and the fusion protein displays the co-stimulatory activity in T lymphocytes activation.

Effect of Icariin on apoptosis and expression of Fas,Fas ligand,B cell lymphoma,and Bcl-2-associated X protein in CD4＋ T lymphocytes from patients with ankylosing spondylitis

OBJECTIVE:To investigate the effects of icariin on apoptosis and the expression of Fas, Fas ligand(Fas L), B cell lymphoma(Bcl-2), and Bcl-2-associated X protein(Bax) in CD4+ T lymphocytes from patients with ankylosing spondylitis.METHODS:Primary cultures of peripheral blood CD4+ T lymphocytes were established and treated with icariin at high, medium, and low doses(0.5,0.25, and 0.125 mg/mL).Sulfasalazine treated and helthy cells were used as controls.Apoptosis of treated cells was determined by flow cytometry.Reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assays were used to determine the effects of icariin on the expression of Fas, Fas L, Bcl-2, and Bax.The activity of caspase 8 and caspase 3 was determined by a colorimetric assay.RESULTS:The m RNA and protein expression of Fas,and activity of caspase 8 and caspase 3 in CD4+ T lymphocytes were increased by icariin(P < 0.05).Conversely, the m RNA and protein expression of Bcl-2 was decreased(P < 0.05).The expression of Fas L and Bax were not significantly different between groups.The proapoptotic effects of icariin were dose-dependent.CONCLUSION:Icariin induces the apoptosis of CD4 + T cells from patients with AS comparing to normal control.Therefore, the induction of apoptosis may be the likely mechanism of action of icariin's antirheumatics activities.

海南木榄叶的蛋白鉴定及在Pb^(2+)、Cd^(2+)胁迫下差异蛋白的分析

木榄(Bruguiera gymnorhiza(L.)Lam.)是海南红树药用植物之一,为深入研究开发木榄叶的价值和功能,采用优化条件下BPP+酚抽提法的双向电泳技术,获得海南木榄叶的蛋白指纹图谱,并筛选出高表达蛋白;利用基质辅助激光解析电离飞行时间质谱(MALDI-TOF-MS)鉴定高表达蛋白的酶水解产物及确定蛋白名称,并进行初步功能分析;另外,对重金属Pd^(2+)和Cd^(2+)胁迫木榄叶条件下的差异蛋白进行分离提取及鉴定。结果表明,海南木榄叶有60个高表达的蛋白,包括差向异构酶、DNA连接酶等42个蛋白,涉及木榄叶生长、发育、遗传及植物抗逆等多种功能;重金属Pd^(2+)和Cd^(2+)胁迫的差异蛋白分别有4个和6个,与植物生长、遗传及高效光合作用等植物功能有关。本研究不仅为进一步开发利用海南产木榄叶中的植物蛋白提供理论依据,也对发现木榄叶与重金属Pd^(2+)、Cd^(2+)胁迫相关的关键蛋白、理解海南岛的生态系统服务和生态效益具有一定的理论和实际意义。

Hg^(2+)-牛血清白蛋白复合体系中蛋白质微观结构的研究

研究了Hg2+在生物体内与牛血清白蛋白相互作用的毒性机理以及蛋白质的微观结构变化。测定了Hg2+与牛血清白蛋白(BSA)复合体系的红外光谱(FT-IR)和圆二色谱(CD),并对图谱进行拟合解析处理。红外光谱实验数据表明Hg2+与BSA发生作用的结合位点可能包括—SH、—OH和—NH基团,采用红外拟合技术对BSA二级结构的变化进行了研究,结果表明蛋白质α-螺旋结构含量降低,β-折叠结构含量升高。圆二色谱图也表明由于一定浓度的Hg2+与BSA结合,从而导致蛋白质的二级结构被破坏,这与拟合红外光谱得到的蛋白质二级结构数据相吻合。Hg2+与牛血清蛋白作用致使蛋白质的构象改变,形成金属离子与蛋白质作用的复合物,因而蛋白质失去活性导致生物体发生病变。

HCV通过抑制T细胞IL-2分泌逃避人体免疫机制的实验研究

目的:探讨丙型肝炎病毒(hepatitisCvirus,HCV)抑制T细胞IL-2分泌的机制,为预防、诊断和治疗丙型肝炎提供新思路。方法:利用卟啉醇肉豆蔻酸乙酸酯(phorobol12-myristate13-acetate,PMA)、植物血凝素(phyto-haemagglutinin,PHA)、Ca2+以及抗CD3抗体(OrthoKungTcell3,OKT3)、抗CD81单克隆抗体以及HCV表面蛋白(envelopeproteinofHCV,EP)刺激jurkatT细胞,采用ELISA方法检测培养液中IL-2的产生量并讨论。结果:单独采用PMA和PHA,PHA和Ca2+,OKT3和抗CD81单克隆抗体刺激jurkatT细胞24h,会产生大量的IL-2。如果在采用上述刺激之前,分别使用抗CD81单克隆抗体或EP预处理jurkatT细胞1h,则在上述刺激之后IL-2的产量明显减少。结论:由于EP可与CD81分子特异结合,可以说明HCVEP通过T细胞表面的CD81分子抑制了IL-2的分泌,导致免疫功能受损。

Clinical heterogeneity of NLRP12-associated autoinflammatory diseases

Nod-like receptor family pyrin domain-containing protein 12 (NLRP12) is one of the critical pattern recognition receptors which participates in the regulation of multiple inflammatory responses. Mutations in NLRP12 cause exceptionally rare NLRP12-associated autoinflammatory disease (NLRP12-AID). So far, very few patients with NLRP12-AID have been identified worldwide;therefore, data on the clinical phenotype and genetic profile are limited. In this study, we reported 10 patients who presented mainly with periodic fever syndrome or arthritis. Next-generation sequencing (NGS) identified 6 heterozygous mutations of NLRP12, including 2 novel null mutations. Of the patients, some with same mutations showed different clinical features. Compared to healthy controls, the increased levels of cytokines were revealed in the patients' plasmas, as well as in the supernatants of patients’ cells stimulated with lipopolysaccharide (LPS) or tumor necrosis factor-α (TNF-α). The missense mutations did not change the protein expression;but decreased level of NLRP12 protein was shown in the null mutations. And in vitro expression assay demonstrated a truncating protein induced by the frameshift mutation. Further functional studies revealed the deleterious effect of mutations on nuclear factor-kappa B (NF-κB) signaling. Both the null and missense mutations impaired their inhibition of NF-κB activation induced by p65. Collectively, this study reported a relatively large NLRP12-AID case series. Our findings expand the clinical spectrum, and reinforce the diversity of genetic mutations and clinical phenotypes. The NLRP12-associated disorder should be considered when autoinflammatory diseases are encountered in the clinical practice, especially for patients presenting with periodic fever but no other genetic cause identified.

Effect of Lichong decoction on expression of Bcl-2 and Bcl-2-associated X protein mRNAs in hysteromyoma model rat

OBJECTIVE:To study on effects of Lichong decoction on expression of apoptosis-controlling genes,Bcl-2 and Bcl-2-associated X protein(Bax) mRNAs in hysteromyoma tissue of the hysteromyoma model rat.METHODS:Fifty Wistar female rats were randomly divided into a normal group,a model group,a Lichong decoction group,a Guizifuling capsule group and a Mifepristone group.The hysteromyoma rat model was established by intraperitoneal injection of exogenous estrin and progestogens.Pathological examination of uterine tissue,uterine coefficient and uterine transverse diameter were made under optic microscope and expressions of Bcl-2 and Bax mRNAs in uterine tissue in the groups were detected with real-time fluorescent quantitative polymerase chain reaction(PCR) technique.RESULTS:After treatment,under microscope it was found that in the Lichong decoction group myometrium thinned,muscle fiber slightly overgrowth or long and thin,regular arrangement,inserting phenomenon of inner circular muscle and external longitudinal muscle was occasionally or not seen in the Lichong decoction group.The uterine coefficient and the uterine transverse diameter significantly decreased(P<0.01),and Bcl-2 mRNA expression significantly decreased(P<0.01) and Bax mRNA expression significantly increased in hysteromyoma tissue(P<0.01) in the Lichong decoction group as compared with the model group.CONCLUSION:Therapeutic effects of Lichong decoction on hysteromyoma is related with decrease of Bcl-2 mRNA expression and increase of Bax mRNA expression.

Baicalin extracted from Huangqin(Radix Scutellariae Baicalensis) induces apoptosis in gastric cancer cells by regulating B cell lymphoma(Bcl-2)/Bcl-2-associated X protein and activating caspase-3 and caspase-9

OBJECTIVE:To evaluate the effects of baicalin in human gastric cancer cells, including apoptosis-inducing effects, and to investigate its underlying mechanisms of action.METHODS:Cell proliferation and apoptosis assays were performed to investigate the anti-proliferation effects of baicalin in human gastric cancer BGC-823 and MGC-803 cells.Real time-quantitative polymerase chain reaction and Western blotting analysis were performed to elucidate the molecular mechanisms underlying the anti-tumor properties of baicalin.RESULTS:In BGC-823 and MGC-803 gastric cancer cells treated with 80, 120, and 160 μmol/L baicalin for 48 h, a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay showed that baicalin significantly inhibited cell proliferation in a dose-dependent manner, while flow cytometric analysis demonstrated that baicalin could induce apoptosis, also in a dose-dependent manner.Moreover, baicalin up-regulated the expression of caspase-3, caspase-9, and B cell lymphoma(Bcl-2)-associated X protein and down-regulated the expression of Bcl-2 at both the m RNA and protein level.CONCLUSION:Baicalin has potential as a therapeutic agent for gastric cancer by inducing apoptosis in cancer cells.

Effect of heparin on apoptosis in human nasopharyngeal carcinoma CNE2 cells

In order to study the mechanism of the effect of heparin on apoptosis in carcinoma cells, the nasopharyngeal carcinoma cell line CNE2 was used to identify the effect of heparin on apoptosis associated with the expression of c-myc, bax, bcl-2 proteins by use of Hoechst 33258 staining, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), agarose gel electrophoresis, and flow cytometry, as well as Western blot analysis. The results showed that heparin induced apoptosis of CNE2 cells including the morphologic changes such as reduction in the volume, and the nuclear chromatin condensation, as well as the 'ladder pattern' revealed by agarose gel electrophoresis of DNA in a concentration-dependent manner. The number of TUNEL-positive cells was dramatically increased to 33.6+/-1.2% from 2.8+/-0.3% by treatment with heparin in different concentrations (10 to approximately 40 kU/L). The apoptotic index was increased to 32.5% from 3.5% by detecting SubG1 peaks on flow cytometry. Western blot analysis showed that levels of bcl-2, bax and c-myc were significantly overexpressed by treatment with the increase of heparin concentrations. These results suggest that heparin induces apoptosis of CNE2 cells, which may be regulated by differential expression of apoptosis-related genes.

JTE-522-induced apoptosis in human gastric adenocarinoma cell line AGS cells by caspase activation accompanying cytochrome C release,membrane translocation of Bax and loss of mitochondrial membrane potential

AIM: To investigate the role of the mitochondrial pathway in JTE-522-induced apoptosis and to investigate the relationship between cytochrome C release, caspase activity and loss of mitochondrial membrane potential (Deltapsim). METHODS: Cell culture, cell counting, ELISA assay, TUNEL, flow cytometry, Western blot and fluorometric assay were employed to investigate the effect of JTE-522 on cell proliferation and apoptosis in AGS cells and related molecular mechanism. RESULTS: JTE-522 inhibited the growth of AGS cells and induced the apoptosis. Caspases 8 and 9 were activated during apoptosis as judged by the appearance of cleavage products from procaspase and the caspase activities to cleave specific fluorogenic substrates. To elucidate whether the activation of caspases 8 and 9 was required for the apoptosis induction, we examined the effect of caspase-specific inhibitors on apoptosis. The results showed that caspase inhibitors significantly inhibited the apoptosis induced by JTE-522. In addition, the membrane translocation of Bax and cytosolic release of cytochrome C accompanying with the decrease of the uptake of Rhodamin 123, were detected at an early stage of apoptosis. Furthermore, Bax translocation, cytochrome C release, and caspase 9 activation were blocked by Z-VAD.fmk and Z-IETD-CHO. CONCLUSION: The present data indicate a crucial association between activation of caspases 8, 9, cytochrome C release, membrane translocation of Bax, loss of Deltapsim and JTE-522-induced apoptosis in AGS cells.

CD99and CD 106(VCAM-1)in human testis

Aim: The expression of the cytokines IL-2, IL-6, IL-10, IFN-γ and TNF-α and the adhesion proteins CD99 and CD106 was studied in the human testis at the protein level. Methods: The expression of the cytokines and the adhesion proteins was assessed using immunohistochemistry and immunoblotting. Results: None of the cytokines studied was present in the human testis, but CD99 and CD106 (VCAM-1) strongly were expressed in all the testes investigated. CD99 was present in the interstitial tissue of the human testis as well as in the Sertoli cells. The identity of the CD99+ interstitial cells is unclear. CD106 (VCAM-1) was present in Leydig cells as well as the basal parts of the Sertoli cells in the seminiferous tubules. In immunoblotting, CD99 was demonstrated at molecular ratios of 46-57 (kD). This is a novel isoform of the molecule. Conclusion: The human testis produces both CD99 and CD106 and as CD106 mediates cell binding to lymphocytes, it is possible that the human Leydig cells adhere to lymphocytes like the rodent Leydig cells. (Asian J Androl 2002 Dec; 4: 243-248)

Inhibitory Function of Tregs via Soluble FGL2 in Chronic Hepatitis B

CD4 + CD25 + CD127 dim/regulatory T cells(Tregs) have been implicated in suppressing T cell immune responses to hepatitis B virus(HBV),but the inhibition mechanism has not being clear yet.This study investigated the effects of soluble FGL2(sFGL2) secreted by Tregs on immune suppression in chronic HBV-infected patients.We verified that sFGL2 protein and mRNA were highly expressed in Tregs.The separated Tregs by using magnetic beads from peripheral blood mononuclear cells(PBMCs) in 20 patients with chronic hepatitis B were co-cultured with PBMCs at a ratio of 1:3 with anti-CD3 stimulating antibody or FGL2 blocking antibody.The proliferation index of CD8 + T cells after blocking FGL2 was higher than that in blank group(3.58±0.18 vs.3.28±0.17,P=0.034) in 18 of 20 samples,and lower than that in CD3 stimulation group(3.82±0.19,P=0.026) in 16 of 20 samples.The IFN-γ secreted in the mixed culture in the absence of Tregs was higher than that in the culture in the presence of Tregs,but it could be abolished by FGL2 blocking antibody.These results suggest that sFGL2 protein secreted by Tregs suppresses the proliferation and function of CD8 + T cells in chronic hepatitis B.

Comparison between synthetic retinoid CD437 and acitretin inhibiting melanoma A375 cell in vitro

Objective： To investigate the effects of synthetic retinoid CD437 and acitretin on cell proliferation, apoptosis, cycle arrest and Bax/ Bcl-2 protein expression of melanoma A375 cell, Methods：MTT assay was used to determine the anti-proliferative effects of CD437 and acitretin on melanoma A375 cell, Flow cytometry was performed to investigate the influence of CD437 and acitretin on cell cycle and cell apoptosis. SABC immunocytochemistry was employed for detection of Bax/bcl-2 protein expressions. Results：10^-5 mol/L CD437 was more effective than acitretin in inhibiting proliferation and inducing apoptosis of A375 cell after 24 h treatment, growth inhibiting ratio and apoptosis ratio（58.6%vs43.25% and 28.03%vs17.13%, P 〈 0.05 respectively）. CD437 promoted G0/G1 arrest in melanoma A375 cell, however acitretin could not. CD437 and acitretin could up-regulate the expression of Bax protein and downregulate the expression of bcl-2 protein（P 〈 0.05）. Conclusion：CD437 is more effective than acitretin in inhibiting proliferation and inducing apoptosis and cycle arrest on A375 cell, CD437 may have more potentialities than acitretin for subsidiary treatment of melanoma. Mitochondrial apoptosis pathway is partially involved in two drugs inducing apoptosis on A375 cell.

A <i>wzt</i>Mutant <i>Burkholderia mallei</i>Is Attenuated and Partially Protects CD1 Mice against Glanders

Burkholderia mallei is the etiologic agent of glanders in solipeds and humans. Lipopolysaccharide (LPS) is a major component of cell envelop of this pathogen. O-antigen, the most external component of LPS, is a virulence factor and a protective antigen in many pathogenic bacteria. Two putative proteins named Wzm (integral membrane protein) and Wzt (hydrophilic ATP-binding protein) are believed to make up an ABC-2 transporter of B. mallei that facilitates transport of components of O-antigen from cytosol to outer-membrane. We studied the importance of wzt (encoding Wzt) to growth, LPS O-antigen profile, and pathogenicity of B. mallei. A wzt mutant strain was generated by deleting a portion of the wzt in B. mallei wild type strain ATCC 23344 by gene replacement. Compared to the wild type strain, the wzt mutant displayed slower growth in vitro and less lethality in CD1 mice when inoculated intraperitoneally. The 50% lethal doses (LD50) of the wild type and the wzt mutant strains were 5.9 × 105 and 9.1 × 105 cfu, respectively. CD1 mice inoculated with a non-lethal dose of the wzt mutant produced specific serum immunoglobulins IgG1 and IgG2a and were partially protected against challenge with 11.2 times LD50 of the wild type strain. These findings suggest that the wzt is required for optimal in vitro growth and pathogenesis of B. mallei, and a wzt mutant protects CD1 mice against glanders.