PDTC对高糖培养大鼠肾成纤维细胞中MCP-1表达的影响

目的:探讨核因子-κB(NF-κB)抑制剂吡咯烷二硫氨基甲酸(PDTC)对高糖培养大鼠肾成纤维细胞(NRK)中单核细胞趋化蛋白-1(MCP-1)表达的影响。方法:将NRK分4组进行体外培养:(1)正常组:5.6mmol/L的葡萄糖;(2)高糖组:30mmol/L葡萄糖;(3)高糖+PDTC1组:30mmo/L葡萄糖+5μmol/LPDTC;(4)高糖+PDTC2组:30mmo/L葡萄糖+10μmol/LPDTC,分别于培养24h、48h取各组NRK采用RT-PCR检测其MCP-1mRNA表达水平,采用WesternBlot检测MCP-1蛋白表达水平。结果:与正常组相比,高糖组MCP-1mRNA和蛋白表达水平显著升高(P<0.05),不同浓度PDTC干预后,MCP-1mRNA和蛋白表达水平显著下降(P<0.05),且随PDTC浓度增大,下降更明显。结论:高糖可使NRK中MCP-1表达增高,PDTC能抑制NRK中MCP-1表达。     

二硫代氨基甲酸吡咯烷对小鼠急性凋亡性肝损伤的效应

目的探讨二硫代氨基甲酸吡咯烷(PDTC)对氨基半乳糖(GalN)/细菌脂多糖(LPS)诱导小鼠急性凋亡性肝损伤的作用及其分子机制。方法设置生理盐水(NS)组、GalN/LPS组、PDTC+GalN/LPS组和PDTC组。每组10只小鼠被用于观察LPS处理后72h内的动物死亡情况;每组6只小鼠经LPS处理后1.5h被取血、处死并留取肝脏,用RT-PCR检测肝脏组织TNF-αmRNA表达水平,用EMSA分析肝脏NF-κB结合活性,每组12只小鼠于LPS处理后8h取血、处死并留取肝脏,测定血清丙氨酸转氨酶(ALT)活力,用TUNEL技术检测肝脏细胞凋亡,并对肝组织切片行常规HE染色。结果GalN/LPS共处理升高小鼠血清ALT活力;肝脏组织病理学检查发现,GalN/LPS组小鼠肝脏严重充血、坏死并伴有大量炎性细胞浸润,肝脏组织TUNEL阳性细胞增多;在GalN/LPS共处理72h内有90%小鼠发生死亡,所有死亡小鼠均伴有肝脏严重充血。PDTC预处理抑制GalN/LPS诱导的肝脏NF-κB激活和TNF-α表达,但PDTC预处理反而加重GalN/LPS引起的小鼠肝脏细胞凋亡、进一步升高血清ALT活力、加重肝脏充血和坏死并加速小鼠死亡。结论NF-κB抑制剂PDTC通过抑制肝脏实质细胞NF-κB介导的抗凋亡机制加重GalN/LPS诱导的小鼠急性凋亡性肝损伤。     

高糖及NF-κB抑制剂PTDC对大鼠肾成纤维细胞ICAM-1表达的影响

目的:探讨高糖及NF-κB抑制剂吡咯烷二硫氨基甲酸(PDTC)对大鼠成纤维细胞中,细胞间黏附蛋白-1(ICAM-1)表达的影响。方法:体外培养大鼠肾小管成纤维细胞(NRK);葡萄糖孵育下分6组:正常对照组,高糖1组,高糖2组含葡萄糖分别为5.6,15和30 mmol/L,干预组在葡萄糖30 mmo/L基础上分别加入PDTC 5,10和20μmol/L;RT-PCR检测24,48 h后各组ICAM-1 mRNA表达水平;免疫细胞化学(ICC)法检测24,48 h各组的ICAM-1表达情况。结果:与正常组相比,高糖组ICAM-1的mRNA和蛋白表达水平显著升高(P<0.05),且呈剂量时间依赖性;而不同浓度PDTC干预后,ICAM-1 mRNA和蛋白表达水平显著下降(P<0.05),而且与PDTC呈剂量时间依赖性。结论:NF-κB抑制剂PDTC可以下调高糖环境下NRK中ICAM-1的表达。     

PDTC对大鼠急性肺血栓栓塞症溶栓后再灌注损伤的保护性研究

目的 探讨抗氧化剂二硫代氨基甲酸吡咯啉烷(PDTC)对大鼠急性肺血栓栓塞症溶栓后肺损伤的干预作用.方法 健康雄性SD大鼠72只.随机分为空白对照组、肺血栓栓塞(PTE)组、溶栓组、溶栓+PDTC组(简称PDTC组).按组再分为栓塞术后或溶栓术后1、2、4 h观测组,每组6只.建立大鼠急性肺血栓栓塞症模型即PTE模型.采用苏木精-伊红染色观测肺组织病理形态,原位缺口末端标记(TUNEL)法检测肺组织细胞凋亡率,Western印迹法检测Caspase-3蛋白含量,采用黄嘌呤氧化酶法检测血浆超氧化物歧化酶(SOD)活性,硫代巴比妥酸法检测丙二醛(MDA)含量.结果 PDTC能有效减轻急性肺血栓栓塞溶栓治疗后肺组织细胞凋亡和再灌注损伤,尤以溶栓后2 h明显.溶栓后2 h,PDTC组Caspase-3蛋白吸光度比值为(0.166±0.005),显著低于溶栓组同时间的吸光度比值(0.228±0.005)(P<0.01);PDTC组肺组织的细胞凋亡率为(24.67±1.21)%,显著低于溶栓组同时间的细胞凋亡率(41.17±2.32)%;PDTC组血浆SOD活性为(69.25±1.64)U/ml,显著高于溶栓组同时间的SOD活性(49.19±1.19)U/ml,PDTC组血浆MDA含量为(3.68±0.13)nmol/ml,显著低于溶栓组同时间血浆MDA含量(5.20±0.14)nmol/ml(均P<0.01).结论 PDTC可能通过提高血浆SOD活性,降低MDA含量,下调Caspase-3蛋白表达,从而抑制溶栓后肺组织细胞异常凋亡,减轻急性肺栓塞溶栓后肺组织的损伤.     

Gypenoside XLIX, a naturally occurring gynosaponin, PPAR-alpha dependently inhibits LPS-induced tissue factor expression and activity in human THP-1 monocytic cells

Tissue factor (TF) is involved not only in the progression of atherosclerosis and other cardiovascular diseases, but is also associated with tumor growth, metastasis, and angiogenesis and hence may be an attractive target for directed cancer therapeutics. Gynostemma pentaphyllum (GP) is widely used in the treatment of various cardiovascular diseases including atherosclerosis, as well as cancers. Gypenoside (Gyp) XLIX, a dammarane-type glycoside, is one of the prominent components in GP. We have recently reported Gyp XLIX to be a potent peroxisome proliferator-activated receptor (PPAR)-alpha activator. Here we demonstrate that Gyp XLIX (0-300 microM) concentration dependently inhibited TF promoter activity after induction by the inflammatory stimulus lipopolysaccharide (LPS) in human monocytic THP-1 cells transfected with promoter reporter constructs pTF-LUC. Furthermore, Gyp XLIX inhibited LPS-induced TF mRNA and protein overexpression in THP-1 monocyte cells. Its inhibition of LPS-induced TF hyperactivity was further confirmed by chromogenic enzyme activity assay. The activities of Gyp XLIX reported in this study were similar to those of Wy-14643, a potent synthetic PPAR-alpha activator. Furthermore, the Gyp XLIX-induced inhibitory effect on TF luciferase activity was completely abolished in the presence of the PPAR-alpha selective antagonist MK-886. The present findings suggest that Gyp XLIX inhibits LPS-induced TF overexpression and enhancement of its activity in human THP-1 monocytic cells via PPAR-alpha-dependent pathways. The data provide new insights into the basis of the use of the traditional Chinese herbal medicine G. pentaphyllum for the treatment of cardiovascular and inflammatory diseases, as well as cancers.     

Role of peroxidases, thiols and Bak/Bax in tumor cell susceptibility to Cu[DEDTC]2

Copper and two molecules of diethyl dithiocarbamate [DEDTC] form the Cu[DEDTC](2) complex, which shows cytotoxicity against melanoma and carcinoma cells, making it a potentially useful anti-cancer agent. The differential response to Cu[DEDTC](2) in susceptible human SKBR3 carcinoma and C8161 melanoma cell variants of moderate and high resistance to this organometallic complex was evaluated in this study. Both cell lines underwent apoptosis-associated PARP cleavage, changes in expression of nuclear NFkB p65, p21WAF1 and cyclin A, with loss of clonogenicity in response to this agent. However, a threefold greater concentration [IC(50) 0.6 microM DEDTC: 0.3 microM Cu] was required to kill moderately resistant C8161 melanoma compared to highly susceptible SKBR3 cells. Decreased susceptibility to Cu[DEDTC](2) in C8161 melanoma correlated with greater levels of glutathione peroxidase and catalase, and a fourfold lower requirement for N-acetyl cysteine (1mM) to overcome toxicity. Whereas melanoma cells selected for resistance to [0.8 microM DEDTC: 0.4 microM Cu] showed persistent catalase and GPx activity, melanoma cells with moderate susceptibility showed decreased catalase and Gpx when responding to treatment. Cytotoxic response in moderately susceptible C8161 melanoma cells involved an early accumulation of pro-apoptotic Bax in the G2 cell cycle phase, followed by an increased ratio of pro-apoptotic Bak to anti-apoptotic Mcl-1 in mitochondria. Our data suggests that Cu[DEDTC](2) toxicity is mediated through an increase in pro-apoptotic Bak/Bax via disruption of the peroxide and thiol metabolism.     

PDTC对缺氧/再给氧时血管内皮细胞ICAM-1,VCAM-1表达的作用

目的为研究心肌缺血-再灌注损伤的机制和治疗途径,检测血管内皮细胞缺氧/再给氧后细胞间黏附分子-1(intracellular adhesion molecule 1,ICAM-1)和血管细胞黏附分子-1(vascular cell adhesion molecule 1,VCAM-1)的表达,探讨抗氧化剂吡咯烷二硫氨基甲酸酯(pyrrolidine dithiocarbamate,PDTC)对血管内皮细胞表面细胞黏附分子表达的抑制作用.方法将培养的人胚肾血管内皮细胞分为3组,缺氧组:细胞经过缺氧/再给氧处理;PDTC组:在缺氧前于培养液中加入PDTC;对照组:未经处理.以多光子激光共聚焦显微镜分别检测3组细胞ICAM-1、VCAM-1的表达情况.结果对照组内皮细胞表面ICAM-1和VCAM-1呈较低表达,缺氧组呈较高表达;PDTC组ICAM-1和VCAM-1的表达明显低于缺氧组,但仍高于对照组.结论缺氧/再给氧促进内皮细胞活化,增强细胞黏附分子的表达,抗氧化剂PDTC能有效降低ICAM-1和VCAM-1的表达,为心肌缺血-再灌注损伤的治疗提供理论基础.     

Pyrrolidine dithiocarbamate reduces ischemia-reperfusion injury of the small intestine

AIM: To evaluate whether pyrrolidine dithiocarbamate (PDTC), an enhancer of HO production, attenuates intestinal IR injury. METHODS: Eighteen male rats were randomly allocated into three groups: (a) sham; (b) IR, consisting of 30 min of intestinal ischemia, followed by 2-h period of reperfusion; and (c) PDTC treatment before IR. Intestinal microvascular perfusion (IMP) was monitored continuously by laser Doppler flowmetry. At the end of the reperfusion, serum samples for lactate dehydrogenase (LDH) levels and biopsies of ileum were obtained. HO activity in the ileum was assessed at the end of the reperfusion period. RESULTS: At the end of the reperfusion in the IR group, IMP recovered partially to 42.5% of baseline (P<0.05 vs sham), whereas PDTC improved IMP to 67.3% of baseline (P<0.01 vs IR). There was a twofold increase in HO activity in PDTC group (2 062.66±106.11) as compared to IR (842.3±85.12) (P<0.001). LDH was significantly reduced (P<0.001) in PDTC group (585.6±102.4) as compared to IR group (1 973.8±306.5). Histological examination showed that the ileal mucosa was significantly less injured in PDTC group as compared with IR group. CONCLUSION: Our study demonstrates that PDTC improves the IMP and attenuates IR injury of the intestine possibly via HO production. Additional studies are warranted to evaluate the clinical efficacy of PDTC in the prevention of IR injury of the small intestine.     

CX3CR1参与NF-κB在脊髓水平调控大鼠癌痛的研究

目的 研究鞘内注射核因子-κB（NF-κB）抑制剂二硫代氨基甲酸吡咯烷（pyrrolidine dithiocar-bamate,PDTC）对骨癌痛大鼠痛觉过敏、脊髓NF-κB和CX3CR1表达的影响.方法 雌性SD大鼠40只,随机分为5组（n=8）：对照组（naive组）、假手术组（sham组）、骨癌痛组（BCP组）、骨癌痛＋生理盐水组（BCP＋ saline组）、骨癌痛＋ PDTC 100 pmol·d-组（BCP＋PDTC组）.术后7～ 14天,BCP＋PDTC组将100pmol·d-1PDTC溶于10μl生理盐水鞘内注射;sham组、BCP＋ saline组给予等容积的生理盐水.分别测定0、1、3、5、7、9、11、14天的大鼠机械性痛觉过敏（PMWT）及自发性疼痛评分;Western blot法测定脊髓NF-κB和CX3CR1蛋白的表达水平.结果 与sham组比,术后第3天开始,BCP组大鼠PMWT减少,自发性疼痛评分增加（P＜0.05或P＜0.01）.与BCP＋ saline组比,BCP＋ PDTC组大鼠PMWT增加,自发性疼痛评分减少（P＜0.05或P＜0.01）.NF-κB和CX3CR1表达下调（P＜0.01）.结论 PDTC可以减轻骨癌痛大鼠的痛觉过敏,其机制可能与降低脊髓NF-κB和CX3CR1表达有关.