IL-2对垂体瘤细胞系RC-4B/C细胞分泌ACTH的影响

目的 :探讨白细胞介素 2 (IL 2 )对垂体瘤细胞系RC 4B/C细胞ACTH分泌的调控作用及其影响因素 .方法 :以放射免疫方法测定培养的垂体瘤细胞系RC 4B/C细胞的培养液中的ACTH浓度 .结果 :IL 2 (1× 10 4～ 5× 10 5U·L-1)促进RC 4B/C细胞分泌ACTH ;蛋白激酶A的抑制剂H 9(1μmol·L-1)和酪氨酸蛋白激酶的抑制剂tyrphostin2 3 (1μmol·L-1)均可显著性抑制IL 2的促ACTH分泌作用 .结论 :IL 2可促进RC 4B/C细胞分泌ACTH ,该作用与蛋白激酶A和酪氨酸蛋白激酶信号转导途径紧密相关     

TK/GCV、CD/5-Fc双自杀基因系统治疗结肠癌的实验研究

目的观察胸苷激酶/丙氧鸟苷(TK/GCV)、胞嘧啶脱氨酶/5-氟胞嘧啶(CD/5-Fc)双自杀基因系统对结肠癌的治疗效果,并结合研究结果进行作用机理的分析。方法采用培养细胞移植法,将人结肠癌细胞系SW480接种于裸鼠背部皮下,建立裸鼠人结肠癌移植瘤模型。将32只裸鼠随机分为4组:空白对照组,TK/GCV治疗组,CD/5-Fc治疗组,TK/GCV CD/5-Fc联合治疗组,每组8只。TK/GCV CD/5-Fc采用逆转录病毒介导,采用瘤体内直接注射法,同时腹腔注射GCV、5-Fc治疗,观察各组小鼠的生存状况及肿瘤体积、瘤重、肿瘤生长抑制率、常规病理、生存期等指标,比较观察各治疗组的治疗效果及对荷瘤裸鼠存活的影响。结果各治疗组裸鼠人结肠癌移植瘤的生长均受到显著抑制,治疗后各组体积数增加(P<0.05),治疗组裸鼠存活期显著延长,TK/GCV CD/5-Fc联合治疗组效果最好,疗效q值=1.675>1.15,即TK/GCV、CD/5-Fc有交互协同作用。结论TK/GCV与CD/5-Fc对人结肠癌SW480细胞有明显抑制作用,TK/GCV、CD/5-Fc双自杀基因系统效果更强。     

Activities of creatine kinase isoenzymes in single skeletal muscle fibres of trained and untrained rats

Biochemical changes in the creatine kinase isoenzyme compositions in single muscle fibres of different types in rats were induced by endurance running training. Single muscle fibres were dissected from the soleus and extensor digitorum longus muscles of Wistarstrain male rats trained on a motor-driven treadmill for 16 weeks. Each fibre was typed histochemically (SO, slow-twitch oxidative; FOG, fast-twitch oxidative glycolytic; FG, fast-twitch glycolytic), and the activities of total creatine kinase and its four isoenzymes (CK-MM, -MB,-BB, and mitochondrial creatine kinase) were measured. The endurance training did not affect the total creatine kinase activity, but resulted in significantly increased activities of CK-MB and CK-BB in SO and FOG fibres, and the mitochondrial enzyme activity in FOG and FG fibres. Endurance training induced biochemical changes in the isoenzyme compositions, specifically in FOG fibres. These results suggest that changes in creatine kinase isoenzymes with endurance training reflect changes in the energy metabolism in the different muscle fibres, supporting the hypothesis that the different isoenzymes play different roles in energy transduction.     

红细胞同工酶ADA－EAP一AK_1同步电泳分型方法的建立

综合、改良了分别分型的方法，建立了红细胞同工酶ＡＤＡ一ＥＡＰ一ＡＫ１同步电泳分型方法，为ＡＤＡ，ＥＡＰ和ＡＫ１３种红细胞同工酶在法医学鉴定中更广泛的应用，提供了一种可靠、经济、实用的方法。     

Evidence for negative control in protein kinase C substrate specificity

The peptide Leu-Asp-Asp-Ser-Lys-Arg-Val-Ala-Lys-Arg-Lys-Leu-Ile-Glu, which corresponds to sequence 124 to 137 of c-erb-A protein, was synthesized and tested as substrate for protein kinase C (PKC). Although a typical recognition sequence for PKC, consisting of a cluster of basic residues, is found on the C-terminus side of serine, its phosphorylation was totally prevented by the presence of the two acidic residues on the amino-terminus side. Three analogs in which aspartyl residues were successively replaced with alanine were studied and the influence of the acidic side chain in modulating phosphorylation by PKC was thus possible to determine. The results show that the presence of a single aspartyl residue located in positions i-1 or i-2 with respect to the phosphorylable residue can almost totally abolish the positive effect of a highly favorable cluster of basic residues. These observations highlight the role of negative substrate specificity determinants in settling the protein substrate profile of protein kinase C.     

Wortmannin抑制PI3-K途径对K562及NB4细胞增殖的影响

目的 :为探讨Wortmannin抑制磷酰肌醇 - 3激酶 (PI- 3K)途径对K5 62 ,NB4细胞增殖的影响 ,探寻慢性髓细胞性白血病 (CML)的治疗新途径 .方法 :用磷酰肌醇 - 3激酶 (PI - 3K)特异抑制剂Wort mannin抑制PI - 3K活性 ,观察慢性髓细胞性白血病细胞系K5 62细胞和急性早幼粒细胞性白血病细胞系NB4细胞在 2 4,48,72h增殖能力的变化 .t检验统计分析 .结果 :K5 62和NB4细胞在 2 4,48,72h的增殖抑制率分别为 3 4 67% ,5 7 46% ,65 85 %和 2 6 2 9% ,5 5 1% ,2 10 % .集落形成实验以GM -CSF为主要生长刺激物的培养体系在 3 7℃ ,5 %CO2 孵箱培养 14d后细胞系的集落数和集落形成率分别为K5 62 :80 75±10 2 4和 16 15 % ,K5 62 +WT :3 8 0 0± 12 75和 7 60 % ,NB4:2 9 5 0± 5 97和 5 90 % ,NB4+WT :3 0 5 0± 5 74和 6 10 % .集落形成抑制率为 :5 2 94%和 3 3 9% .结论 :Wortmannin可显著抑制K5 62细胞的增殖和集落形成 ,而对NB4细胞无明显影响 (P均 <0 0 5 ) .Wortmannin可以通过抑制PI - 3K通路抑制K5 62细胞的增殖 ,而对NB4细胞增殖无明显影响     

神经病理性疼痛大鼠脊髓背角蛋白激酶Cγ及Cα表达的变化

目的 评价慢性神经收缩损伤（CCI）和脊神经结扎（SNL）模型大鼠脊髓背角蛋白激酶Cγ及Cα表达的变化，以探讨其在神经病理性疼痛中枢敏化中的作用。方法 24只SD大鼠随机分为假手术组、CCI组和SNL组，CCI组于左肢制备CCI模型，SNL组于左肢制备SNL模型。分别于术前2d、术后2、4、7d行机械痛阈和辐射热痛阈测定。术后7d测痛后大鼠灌注固定，采用免疫组化法检测脊髓背角蛋白激酶Cγ、Cα和Fos蛋白的表达。结果 与假手术组相比，CCI组和SNL组术后4、7d机械痛阈和辐射热痛阈降低，术后7d脊髓背角蛋白激酶Cγ、Cα和Fos蛋白表达增加（P〈0．05）。与CCI组相比，SNL组机械痛阈、辐射热痛阈在各时间点差异无统计学意义，蛋白激酶Cα和Fos蛋白表达差异亦无统计学意义（P〉0．05），而蛋白激酶Cγ表达升高（P〈0．05）。结论 神经病理性疼痛大鼠脊髓背角蛋白激酶Cγ及Cα表达的增加，可能是产生中枢敏化的机制之一。     

Histamine differentially interacts with tumor necrosis factor-α and thrombin in endothelial tissue factor induction: the role of c-Jun NH2-terminal kinase

BACKGROUND: Histamine plays an important role in vascular disease. Tissue factor (TF) expression is induced in vascular inflammation and acute coronary syndromes. OBJECTIVES: This study examined the effect of histamine on tumor necrosis factor-alpha- (TNF-alpha-) vs. thrombin-induced endothelial TF expression. METHODS AND RESULTS: Histamine (10(-8)-10(-5) mol L-1), TNF-alpha (5 ng mL-1), and thrombin (1 U mL-1) induced TF expression in human endothelial cells. Although TF expression by TNF-alpha and thrombin was identical, histamine augmented TNF-alpha-induced expression 7.0-fold, but thrombin-induced expression only 2.6-fold. Similar responses occurred with TF activity. The H1-receptor antagonist mepyramine abrogated these effects. Differential augmentation by histamine was also observed at the mRNA level. Histamine-induced p38 activation preceded a weak second activation to both TNF-alpha and thrombin. Histamine-induced c-Jun NH2-terminal kinase (JNK) activation was followed by a strong second activation to TNF-alpha, and less to thrombin. Selective inhibition of this second JNK activation by SP600125 reduced TF induction to histamine plus TNF-alpha by 67%, but to histamine plus thrombin by only 32%. Histamine augmented TNF-alpha- and thrombin-induced vascular cell adhesion molecule 1 (VCAM-1) expression to a similar extent. Consistent with this observation, VCAM-1 induction to TNF-alpha and thrombin was mediated by p38, but not by JNK. CONCLUSIONS: Histamine differentially augments TNF-alpha- vs. thrombin-induced TF expression and activity, which is mediated by the H1-receptor, occurs at the mRNA level, and is related to differential JNK activation.     

靶向性蛋白激酶B1和环氧合酶-2 shRNA腺病毒载体的构建和在人胃癌细胞的表达

Objective To construct a short hairpin RNA (shRNA) adenovirus vector targeting protein kinase BI (PKB1/Akt1) and cyclooxygenase-2 (COX-2) and observe their expression in human gastric carcinoma cell line SGC-7901. Methods Akt1 and COX-2 shRNA expression frames were sub-cloned to pGSadeno adenovirus vector by homologous recombination technology to construct pGSadeno-Aktl + COX-2 ( pGSadeno-A + C) vector. Furthermore after screening and amplification,recombinant ade-novirus vector was digested with Pacl and transfected into HEK293 cells. The replication adenovirus rAd5-A + C was packed and amplified in the HEK293 cells, and its titer was detected. After human SGC-7901 cells in vitro were transfected by rAd5-A + C,Akt1 and COX-2 mRNA and protein expression levels were detected by real-time PCR and Western blot respectively. Compared with rAdS-A + C,SGC-7901 and gen-eral rAd5-HK were selected as the negative controls. Results The recombinant adenovirus rAd5-A + C was constructed successfully and its titer reached 1.0 ×1010 pfu/ml. Aktl and COX-2 mRNA expression was downregulated significantly, and their ACt values ( 12.26±0.05 and 5.41±0.09 respectively ) were higher than rAd5-HK group (10.63±0.02 and 3.75 +0.08 respectively) and control group (10.57± 0.02 and 3.73±0.08 respectively) (P <0.01 ). There was no significant difference between rAd5-HK and control groups (P >0.05). Aktl and COX-2 protein expression was downregulated by 70.5% and 63.7% respectively ( P < 0.01 ) in rAd5-HK group as compared with control group ( P > 0.05 ). Conclu-sion The shRNA aclenovirus vector targeting Akt1 and COX-2 can specifically inhibit Akt1 and COX-2 expression,and this may be a new strategy in gastric carcinoma gene therapy targeting Akt1 and COX-2.