基质金属蛋白酶及其抑制剂与眼部疾病

基质金属蛋白酶(matrix metalloproteinases,MMPs)是一类金属依赖的水解酶家族,是细胞外基质(extracelluarmatrix,ECM)降解的主要介质,其主要功能是降解细胞外基质,在细胞迁移、组织重建和修复等病理生理过程中发挥作用.     

内质网应激在UCH-L1抑制剂诱导细胞凋亡中的作用

目的探讨内质网应激(ERS)在泛素羧基末端水解酶-1(UCH-L1)抑制剂导致的细胞损伤过程中的作用。方法采用50μmol/L的UCH-L1抑制剂处理人神经母细胞瘤SK-N-SH细胞。于处理前(对照组)和处理后不同时间点(2、4、6、12、24h),分别采用MTT比色法和Western blotting法检测细胞活力和ERS相关蛋白Bip/Grp78、Xbp-1、p-eIF2α及其促凋亡转录因子CHOP/Gadd153的表达。结果MTT比色法检测发现,50μmol/LUCH-L1抑制剂处理后4h,SK-N-SH细胞活力下降43.1%(P<0.05),且随处理时间的延长继续呈现显著下降趋势(P<0.01)。Western blotting检测显示,经50μmol/LUCH-L1抑制剂处理后,SK-N-SH细胞ERS相关蛋白Bip/Grp78、p-eIF2α和Xbp-1表达分别于处理后2、4、6h时显著增加;转录因子CHOP/Gadd153表达则在处理后2h和4h时略有增加,6h后达到高峰。结论在UCH-L1抑制剂诱导的细胞凋亡过程中,ERS是导致细胞损伤的路径之一。     

菌斑蛋白水解酶的分离纯化及活性测定

为了解人牙根面菌斑中蛋白水解酶的种类和活性。采用ＳｅｐｈａｄｅｘＧ－２００层析技术和荧光分光光度法对收集和菌斑中的蛋白水解酶进行了分离纯化及活性测定。结果发现，亮氨酸氨肽酶和甘氨酰脯氨酸二肽酶和胰酶样蛋白酶存在于根面菌斑中，且均有一定的活性。     

氟对大鼠软骨丝氨酸蛋白水解酶活性的影响

目的；研究慢氟中毒大鼠软丝氨酸蛋白水解酶（ＳＰＥ）活性的变化。方法：用不同饲料喂养大白鼠，测定软骨中的ＳＰＥ活力。结果：偏食大鼠在饮用含２００ｐｐｍ的氟化钠水１０周后，股骨头软骨和肋软骨中ＳＰＥ蛋白水解酶活力仅显著高于正常膳食和饮氟水组；而与单纯偏食组比较无显著差异。两个偏食组动物软骨中ＤＮＡ含量高于两个正常膳食组，但饮氟水未能使软骨中的ＤＮＡ含量改变。结论：高氟可能提高营养不良鼠软骨中的ＳＰＥ活     

小儿支气管哮喘与血小板活化因子乙酰水解酶的相关性研究

为探讨血浆血小板活化因子乙酰水解酶(PAF-AH)基因多态性与我国哮喘儿童的相关性及其多态性与血浆PAF-AH酶活性的关系,我们于2001年10月至2003年3月。应用等位基因特异性聚合酶链式反应(AS—PCR)技术,对哮喘发作期儿童PAF-AH第9外显子上G994-T基因位点的突变进行了检测,同时应用酶水解底物显色法检测血浆PAF-AH活性。现报告如下。     

Relationship between polymorphisms of genes encoding microsomal epoxide hydrolase and glutathione S-transferase P1 and chronic obstructive pulmonary disease

Background Cigarette smoking is the major risk factor for chronic obstructive pulmonary disease (COPD). However, only 10% -20% of chronic heavy cigarette smokers develop symptomatic disease. COPD is most likely the result of complex interactions between environmental and genetic factors. Genetic susceptibility to COPD might depend on the variations in enzyme activities that detoxify cigarette smoke products, such as microsomal epoxide hydrolase (mEH) and glutathione Stransferase (GST). In this study, we investigated the relationship between polymorphisms in the genes encoding mEH and glutathione S-transferase P1 (GSTP1) and COPD in a Chinese population.Methods Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed to find mEH polymorphism in exon 3 (Tyr113→His), exon 4 (His139→Arg) and GSTP1 polymorphism in exon 5 (Ile105→Val) in 100 COPD patients and 100 age- and sex-matched healthy controls.Results The proportion of mEH exon 3 heterozygotes was significantly higher in patients with COPD than that in the control subjects (42% vs 32% ). The odds ratio (OR) adjusted by age, sex, body mass index (BMI) and cigarette years was 2.96 (95% CI 1.24 - 7. 09). There was no marked difference in very slow activity genotype versus other genotypes between COPD patients and the controls. When COPD patients were non-smokers, the OR of very slow activity genotype versus other genotypes was more than 1.00; and when COPD patients were smokers ( current smokers and exsmokers), the OR was less than 1.00. There was no significant difference in GSTP1 polymorphism adjusted by age, sex, BMI and smoking between COPD patients and the controls.Conclusions mEH exon 3 heterozygotes might be associated with susceptibility to COPD in China.The interaction might exist between mEH genotype and smoke. The gene polymorphism for GSTP1 might not be associated with susceptibility to COPD in the Chinese population.     

Aspirin protected against endothelial damage induced by LDL： role of endogenous NO synthase inhibitors in rats

AIM: To study the protective effect of aspirin on damages of the endothelium induced by low-density lipoprotein (LDL), and whether the protective effect of aspirin is related to reduction of nitric oxide synthase inhibitor level.METHODS: Vascular endothelial injury was induced by a single injection of native LDL (4 mg/kg) in rats. Vasodilator responses to acetylcholine (ACh) in the isolated aortic rings were determined, and serum concentrations ofasymmetric dimethylarginine (ADMA), malondialdehyde (MDA), tumour necrosis factor-α (TNF-α), and the activity of dimethylaminohydrolase (DDAH) were measured. RESULTS: A single injection of LDL (4 mg/kg)significantly decreased vasodilator responses to ACh, increased the serum level of ADMA, MDA, and TNF-α, anddecreased DDAH activity. Aspirin (30 or 100 mg/kg) markedly reduced the inhibition of vasodilator responses toACh by LDL, and the protective effect of aspirin at the lower dose was greater compared with high-dose aspiringroup. Aspirin inhibited the increased level of MDA and TNF-α induced by LDL. Aspirin at the dose of 30 mg/kg,but not at higher dose (100 mg/kg), significantly reduced the concentration of ADMA and increased the activity ofDDAH. CONCLUSION: Aspirin at the lower dose (30 mg/kg) protects the endothelium against damages elicitedby LDL in vivo, and the protective effect of aspirin on endothelium is related to reduction of ADMA concentrationby increasing DDAH activity.     

052重组有机磷水解酶的研究进展

有机磷水解酶(OPH)是处理有机磷杀虫剂和化学战剂污染最有前途的酶.大规模使用需要进行重组.目前的研究主要集中于提高重组有机磷水解酶的表达水平、活性及稳定性.对其在化学防护与洗消、临床和有机磷生物探测器等方面的应用也有研究.     

人参养荣汤改善老龄鼠小肠粘膜上皮纹状缘吸收功能作用的研究

目的：观察中药人参养荣汤对老龄鼠小肠粘膜纹状缘吸收功能的影响。方法：将ICR系70周龄雌性小鼠分为老龄对照与人参养荣汤用药组,每组20只,灌胃4周,取空肠组织进行碱性磷酸酶（ALP）,亮氨酸氨肽酶（LAP）,腺苷三磷酸酶（ATPase）染色,利用图象处理系统测量ALP、LAP、ATPase养 色面积,计算消化酶活性率。采用冰冻蚀法复制微绒毛膜膜内粒子形态,透射电镜下观察二糖类分解酶活性部位的变化。通过计测微绒毛及表面糖衣吸附feritin的个数、微绒毛糖衣层钌红电子染色,观察糖衣吸附功能及荷电位,结果：人参养荣汤用药组可显著提高ALP、LAP,ATPase活性率。结论：人参养荣汤能促进二糖酶合成,并显著提高糖衣吸附蛋白能力和增强糖锁阴性荷电位。     

血小板活化因子水解酶基因突变与原发性肾病综合征的相关性

目的研究血小板活化因子水解酶（PAF—AH）基因突变与不同类型原发性肾病综合征（PNS）的相关性。方法94例PNS患儿，依据对激素治疗的效应分为激素敏感型NS（SSNS）组37例,激素耐药型NS（SRNS）组26例，激素依赖型NS（SPNS）组31例，239例健康对照组儿童作为对照，应用聚合酶链反应（PER）及聚丙烯酰胺凝胶电泳分析的方法检测其PAF—AH基因第9外显子-994位点基因型及等位基因频率，同时对各种PAF—AH基因型的PNS患儿的病情反复情况进行对比分析。结果NTNS患儿血浆型-PAF—AH基因-994位点基因突变频率显著高于STNS及健康对照组；所有PNS及SSNS、SRNS与健康对照组儿童比较，PAF—AH基因．第9外显子-994位点基因突变频率差异无统计学意义，SDNS组突变频率显著高于健康对照及SSNS组；PAF—AH基因第9外显子-994位点基因GT型或TT型第1年内反复次数显著高于GG型者。结论血浆型PAF—AH基因第9外显子-994位点基因突变的PNS患儿在临床类型上多为NTNS，且易于在以后的治疗中出现依赖倾向。