白芦藜醇对骨肉瘤细胞U-2OS增殖和凋亡的影响及其分子机制

目的观察白芦藜醇(resveratrol,Res)对骨肉瘤细胞U-2OS增殖和凋亡的影响,并探讨其可能的分子机制。方法体外培养人骨肉瘤细胞U-2OS,用不同浓度的Res(5、10、20、40、80μmol/L)作用不同时间(24、48、72 h)后,MTT法检测Res对U-2OS细胞增殖活力的影响;流式细胞术检测Res对细胞周期和凋亡的影响;应用Caspase-3活性检测试剂盒检测Caspase-3酶活性;Western blot检测细胞内Bax、Bcl-2和Caspase 3蛋白的表达水平。结果 Res作用24 h时,与空白对照组及DMSO组比较,20和40μmol/L Res组的细胞增殖抑制率、G0/G1和G2/M期的细胞比例、细胞凋亡率、Caspase-3酶活性显著升高(P0.05),S期细胞比例显著降低(P0.05);20μmol/L Res组U-2OS细胞中Bax和Caspase-3蛋白表达水平显著升高(P0.05),而Bcl-2蛋白表达水平明显降低(P0.05)。结论 Res通过诱导提高Caspase-3酶活性,上调促凋亡基因Bax、Caspase-3及下调抗凋亡基因Bcl-2蛋白的表达水平,从而抑制U-2OS细胞的增殖,促进其凋亡,为Res治疗骨肉瘤提供了实验依据。     

聚酯合成动力学模型的建立及其应用

以静脉和腹腔给药方式，观察了刺五加对垂体后叶素和异丙肾上腺素所致ＳＤ大鼠缺血心肌的保护作用。实验结果可见：刺五加能显著减轻垂体后叶素引起的大鼠心肌缺血时过氧化物岐化酶活性降低，抑制脂质过氧化物的生成，并对急性心肌缺血性心电图改变有明显的预防作用；而对异丙肾上腺素所致的大鼠心肌缺血心电图的ＳＴ段偏移亦有对抗作用，也能保护ＳＯＤ活性和减少ＭＤＡ生成，并能明显减轻异丙肾上腺素造成的大鼠心肌超微结构的损伤     

不同剂量瑞芬太尼对缺血再灌注时大鼠肾细胞凋亡和bcl-2、bax表达的影响

目的观察不同剂量瑞芬太尼对大鼠肾缺血再灌注后肾小管细胞凋亡及其调控基因bcl-2和bax表达的影响,探讨瑞芬太尼肾保护作用的分子生物学机制。方法用动脉夹夹闭大鼠双侧肾蒂45min再灌注6h方法制成急性肾缺血再灌注损伤模型。采用脱氧核苷酸末端转移酶介导的DNA原位末端标记技术检测细胞凋亡的情况。免疫组化检测Bcl-2、Bax基因表达。结果缺血再灌注组较假手术组肾小管凋亡细胞数明显增多,Bcl-2、Bax表达均增强,Bax/Bcl-2比值增高;瑞芬太尼各剂量处理组较缺血再灌注组凋亡细胞数明显减少,Bcl-2表达进一步增强,而Bax表达减弱,Bax/Bcl-2降低。结论瑞芬太尼可能通过上调Bcl-2基因表达,下调Bax基因表达,抑制细胞凋亡,从而发挥对缺血再灌注损伤肾脏的保护作用。     

腺苷对缺血再灌注后心肌的保护作用

目的研究腺苷对大鼠心肌细胞凋亡及核因子κB(NF-κB)表达的影响。方法制备对照组(C组)、缺血再灌注损伤组(I/R组)和缺血再灌注前腺苷治疗组(AD组)的大鼠模型。电镜、光镜下观察心肌结构变化,采用原位缺口末端标记法(TUNEL)检测心肌细胞凋亡,免疫组织化学方法检测心肌组织NF-κB表达。结果AD组大鼠心肌细胞凋亡数(2 645.0±326.0)及心肌组织中NF-κB的表达(32.21%±17.91%)明显低于I/R组(5 113.0±503.7和60.30%±10.36%),明显高于对照组(67.7±51.3和11.98%±3.65%)。结论腺苷具有明显降低大鼠缺血再灌注后心肌细胞凋亡的作用,可能与腺苷减轻缺血再灌注心肌组织过度表达NF-κB有关。     

糖原合成酶激酶-3β介导低氧诱导因子-1α抗心肌缺血/再灌注损伤的作用

目的通过稳定低氧诱导因子-1α(hypoxia inducible factor-1α,HIF-1α)的表达,探讨其是否通过糖原合成酶激酶-3β(glycogen synthase kinase-3β,GSK-3β)减轻大鼠心肌缺血/再灌注损伤。方法将雄性SD大鼠随机分为5组:假手术组(Sham组)、心肌缺血/再灌组(I/R组)、HIF-1α稳定剂二甲氧乙二酰甘氨酸(dimethyloxalyl glycine,DMOG)+心肌缺血/再灌注组(DMOG+I/R组)、HIF-1α抑制剂YC-1+I/R组(YC-1+I/R组)、DMOG+GSK-3β抑制剂SB216763+I/R组(DMOG+SB216763+I/R组)。各组进行相应处理后,处死大鼠并采集样本,Western blot法检测心肌组织中HIF-1α、总GSK-3β、p-GSK-3β(Ser9)、UCP3蛋白表达量;Real-time PCR法检测心肌组织中VEGF、HO-1、Bcl2基因mRNA转录水平;HE染色法检测心肌损伤情况;免疫组化法检测心肌细胞炎性浸润情况;TUNEL染色法检测心肌细胞凋亡情况。结果与I/R组相比,DMOG预处理组可上调I/R大鼠心肌组织中HIF-1α蛋白及其下游因子VEGF、HO-1、Bcl2 mRNA表达水平,并引起线粒体内膜UCP3蛋白及mRNA表达水平升高,同时明显上调p-GSK-3β(Ser9)蛋白表达,并减轻心肌损伤、炎性细胞浸润及降低心肌细胞凋亡率(P <0. 05);与DMOG预处理组相比,给予GSK-3β抑制剂SB216763后,HIF-1α的心肌保护效应明显下降(P <0. 05)。结论 HIF-1α可减轻心肌缺血/再灌注损伤,其心脏保护作用应与GSK-3β的介导有关。     

柚皮苷对大鼠心肌缺血/再灌注损伤细胞凋亡的影响及作用机制

目的观察柚皮苷(Naringin,Nar)对大鼠心肌缺血/再灌注损伤(myocardial ischemia/reperfusion injury,MI/RI)细胞凋亡的影响,并探讨其作用机制。方法将10只大鼠经冠状动脉左前降支结扎30 min,再灌注120 min,建立MI/RI模型;低、中、高Nar干预组大鼠分别用10、20和40 mg/kg的Nar灌胃,1次/d,连续给药7 d,末次灌胃给药后60 min,进行MI/RI手术(同MI/RI模型组),每组10只;同时设假手术组(在冠状动脉前降支下只穿线不结扎)。采用TUNEL染色法检测细胞凋亡情况,Western blot法检测心肌组织中葡萄糖调节蛋白78(glucose-regulated protein78,GRP78)的表达水平。结果与假手术组比较,MI/RI模型组大鼠心肌细胞凋亡数和心肌组织中GRP78表达水平均明显升高(P0.001);与MI/RI模型组相比,10、20和40 mg/kg Nar组大鼠心肌细胞凋亡数和心肌组织中GRP78表达水平均明显降低(P0.01);与10 mg/kg Nar组比较,20和40 mg/kg Nar组的GRP78表达水平显著下调(P0.001)。结论 Nar对MI/RI有明显保护作用,该作用可能与其抑制内质网应激(endoplasmic reticulum stress,ERS)相关蛋白GRP78的表达,减少细胞凋亡有关。     

白藜芦醇对人腺泡横纹肌肉瘤细胞株PLA-802增殖和凋亡的影响及其分子机制

目的观察白藜芦醇(Resveratrol,Res)对人腺泡横纹肌肉瘤(rhabdomyosarcoma,RMS)细胞株PLA-802增殖及凋亡的影响,并探讨其可能的分子机制。方法体外培养PLA-802细胞,用不同浓度的Res(25、50、100、200μmol/L)作用不同时间(24、48、72 h)。MTT法检测Res对PLA-802细胞增殖活力的影响;流式细胞术检测Res对PLA-802细胞周期和凋亡的影响;采用Caspase-3活性检测试剂盒检测Caspase-3酶的活性;Western blot法检测PLA-802细胞中与凋亡密切相关的Bax、Bcl-2、Survivin和Caspase-3酶蛋白的表达水平。结果 Res可明显抑制PLA-802细胞的增殖(P0.05)及提高Caspase-3酶活性(P0.001),且呈剂量-时间依赖性;同时可明显提高处于G0/G1及G2/M期的细胞比例(P0.01),减少S期细胞比例(P0.001),促进PLA-802细胞的凋亡,且可显著增加促凋亡蛋白Bax和Caspase-3的表达水平(P0.05),降低抗凋亡蛋白Bcl-2和Survivin的表达水平(P0.05)。结论 Res可通过上调Bax、Caspase-3及下调Bcl-2和Survivin蛋白的表达水平及激活Caspase-3酶活性,诱导PLA-802细胞的凋亡并抑制其增殖,为治疗RMS提供了实验依据。     

五味子酯乙通过下调Bcl-2表达增强内在耐药肝癌Bel7402细胞对顺铂诱导的凋亡敏感性

目的:研究探讨五味子酯乙对内在耐药肝癌Bel7402细胞对顺铂诱导的凋亡敏感性的影响及机制。方法:MTT法检测顺铂、五味子酯乙单独或两药联用对Bel7402细胞增殖的影响,Hoechst 33258染色和DNA Ladder检测顺铂、五味子酯乙单独或两药联用对Bel7402细胞凋亡的影响,PI染色检测Bel7402细胞凋亡百分率和细胞周期变化,Westen blot检测Ble7402细胞Caspase-3、Bax和Bcl-2表达水平。结果:低浓度顺铂(2. 5μM)单独作用对Ble7402细胞增殖和凋亡无影响,五味子酯乙与低浓度顺铂联用后剂量依赖性增强对Ble7402细胞的抗增殖作用,诱导Ble7402细胞发生典型凋亡形态学特征变化,显著增加Ble7402细胞凋亡率和S期细胞占比,并显著上调活化Caspase-3水平和降低Bcl-2蛋白表达。结论:五味子酯乙与低浓度顺铂联用通过下调抗凋亡蛋白Bcl-2表达,增强内在耐药肝癌Bel7402细胞的凋亡敏感性。     

慢性脑缺血致认知功能障碍大鼠神经细胞Caspase-3表达及GDNF给药的影响

目的观察慢性脑缺血后致认知功能障碍大鼠神经细胞半胱氨酸蛋白酶(Caspase-3)表达,并探讨胶质细胞源性神经营养因子(GDNF)对大鼠认知功能障碍和Caspase-3表达的影响。方法采用双侧颈总动脉永久结扎方法制备慢性前脑缺血大鼠模型,随机分为对照组、GDNF组和生理盐水组,分别在术后1月、2月,根据逃避潜伏期对各组大鼠进行记忆功能测定,应用免疫组织化学方法检测Caspase-3表达。结果双侧颈总动脉结扎1、2月组与对照组相比,逃避潜伏期明显延长;GDNF组与生理盐水组比较,逃避潜伏期明显缩短;与对照组相比,缺血组大鼠额叶皮层、海马的Caspase-3阳性细胞数明显增多,与生理盐水组比较,1、2月GDNF组大鼠额叶皮层、海马的Caspase-3阳性细胞数明显减少。结论GDNF可改善认知功能,其机制可能是通过影响Caspase-3凋亡关键蛋白酶表达,抑制神经细胞凋亡。     

阿魏酸钠对大鼠纤维化心肌组织中结缔组织生长因子表达的影响

目的探讨阿魏酸钠(Sodium ferulate,SF)对大鼠纤维化心肌组织中结缔组织生长因子(Connective tissue growth factor,CTGF)表达的影响。方法一次性皮下注射盐酸异丙肾上腺素(Isoproterenol,Iso)15mg/kg体重,复制Wistar大鼠心肌缺血性坏死模型,于不同时间点脱臼处死大鼠,取心脏,采用半定量RT-PCR法检测大鼠组织中CTGF基因mRNA的转录水平,免疫组化法检测CTGF蛋白的表达水平。再次复制大鼠心肌缺血坏死模型,同时注射SF进行同步干预,3周后检测大鼠心肌组织中CTGF基因mRNA的转录水平及蛋白的表达水平。结果注射Iso后24h,CTGF基因mRNA的转录水平达高峰,较正常对照组明显增加,3周时仍高于正常对照组;CTGF蛋白的表达随纤维化病变程度的加重而增加。SF干预后,CTGF基因mRNA的转录水平及蛋白的表达水平均明显下降。结论 CTGF的表达与大鼠心肌纤维化(Myocardial fibrosis,MF)程度密切相关,提示CTGF可能在MF中起重要作用;SF对CTGF的表达具有抑制作用。     

Less Expression of Prohibitin Is Associated with Increased Paired Box 2 (PAX2) in Renal Interstitial Fibrosis Rats

Prohibitin (PHB) and paired box 2 (PAX2) are associated with the development of renal interstitial fibrosis (RIF). This study was performed to investigate whether or not the PHB could regulate the PAX2 gene expression in unilateral ureteral obstruction (UUO) in rats. Eighty Wistar male rats were randomly divided into two groups: sham operation group (SHO) and model group subjected to unilateral ureteral obstruction (GU), n = 40, respectively. The model was established by left ureteral ligation. Renal tissues were collected at 14-day and 28-day after surgery. RIF index, protein expression of PHB, PAX2, transforming growth factor-βl (TGF-β1), α-smooth muscle actin (α-SMA), collagen-IV (Col-IV), fibronectin (FN) or cleaved Caspase-3, and cell apoptosis index in renal interstitium, and mRNA expressions of PHB, PAX2 and TGF-β1 in renal tissue were detected. When compared with those in SHO group, expression of PHB (mRNA and protein) was significantly reduced, and expressions of PAX2 and TGF-β1 (protein and mRNA) were markedly increased in the GU group (each p < 0.01). Protein expressions of α-SMA, Col-IV, FN and cleaved Caspase-3, and RIF index or cell apoptosis index in the GU group were markedly increased when compared with those in the SHO group (each p < 0.01). The protein expression of PHB was negatively correlated with protein expression of PAX2, TGF-β1, α-SMA, Col-IV, FN or cleaved Caspase-3, and RIF index or cell apoptosis index (all p < 0.01). In conclusion, less expression of PHB is associated with increased PAX2 gene expression and RIF index in UUO rats, suggesting that increasing the PHB expression is a potential therapeutic target for prevention of RIF.     

邻苯二甲酸二(2-乙基)己酯诱导隐睾对SD幼鼠睾丸生殖细胞凋亡的影响

目的探讨环境内分泌干扰物邻苯二甲酸二(2-乙基)己酯[D(i2-ethylhexy1)phthalate,DEHP]作用于SD孕鼠后,对哺乳期雄性幼鼠睾丸组织中生殖细胞凋亡及凋亡基因Bax和Bcl-2表达的影响。方法将30只妊娠第12.5天的SD孕鼠随机分正常对照组、玉米油对照组和DEHP诱导隐睾组,每组10只。玉米油对照组和DEHP诱导隐睾组自妊娠第12.5～19.5天分别每日灌胃玉米油(2 ml)和DEHP(500 mg/kg),正常对照组不给药。取各组出生后第20天的雄性幼鼠睾丸组织,采用Q-PCR法检测睾丸组织中Bax和Bcl-2基因的水平,流式细胞术检测睾丸生殖细胞的凋亡情况。结果 DEHP诱导隐睾组幼鼠睾丸组织中Bax基因mRNA的水平显著高于两对照组(P<0.000 1),Bcl-2基因mRNA的水平显著低于两对照组(P<0.01);DEHP诱导隐睾组幼鼠睾丸生殖细胞凋亡百分率显著高于两对照组(P<0.000 1)。结论孕期暴露环境内分泌干扰物DEHP可引起雄性子代发生隐睾,且隐睾鼠睾丸生殖细胞凋亡率增加,隐睾子代睾丸组织中凋亡基因Bax和Bcl-2的表达有改变,推测其改变可能参与了生殖细胞的凋亡过程,并可能与隐睾继发的远期不育有关。     

The Role of Sulfur Dioxide in the Regulation of Mitochondrion-Related Cardiomyocyte Apoptosis in Rats with Isopropylarterenol-Induced Myocardial Injury

The authors investigated the regulatory effects of sulfur dioxide (SO₂) on myocardial injury induced by isopropylarterenol (ISO) hydrochloride and its mechanisms. Wistar rats were divided into four groups: control group, ISO group, ISO plus SO₂ group, and SO₂ only group. Cardiac function was measured and cardiomyocyte apoptosis was detected. Bcl-2, bax and cytochrome c (cytc) expressions, and caspase-9 and caspase-3 activities in the left ventricular tissues were examined in the rats. The opening status of myocardial mitochondrial permeability transition pore (MPTP) and membrane potential were analyzed. The results showed that ISO-treated rats developed heart dysfunction and cardiac injury. Furthermore, cardiomyocyte apoptosis in the left ventricular tissues was augmented, left ventricular tissue bcl-2 expression was down-regulated, bax expression was up-regulated, mitochondrial membrane potential was significantly reduced, MPTP opened, cytc release from mitochondrion into cytoplasm was significantly increased, and both caspase-9 and caspase-3 activities were increased. Administration of an SO₂ donor, however, markedly improved heart function and relieved myocardial injury of the ISO-treated rats; it lessened cardiomyocyte apoptosis, up-regulated myocardial bcl-2, down-regulated bax expression, stimulated mitochondrial membrane potential, closed MPTP, and reduced cytc release as well as caspase-9 and caspase-3 activities in the left ventricular tissue. Hence, SO₂ attenuated myocardial injury in association with the inhibition of apoptosis in myocardial tissues, and the bcl-2/cytc/caspase-9/caspase-3 pathway was possibly involved in this process.     

All-trans retinoic Acid treatment is associated with prohibitin expression in renal interstitial fibrosis rats

This study was performed to investigate the association of prohibitin with renal interstitial fibrosis (RIF) lesion and to explore the association of all-trans retinoic acid (ATRA) treatment with prohibitin expression in RIF rats. Rats were divided into three groups: the sham operation group (SHO), the model group subjected to unilateral ureteral obstruction (UUO), and the model group treated with ATRA (GA). Renal tissues were collected at 14 and 28 days after surgery, and the relevant indicators were detected. In comparison with the SHO group, the RIF index in the UUO group was markedly elevated (p < 0.01), and the RIF index in the GA group was alleviated compared with that in the UUO group (p < 0.01). Compared with the SHO group, the expression of prohibitin (protein or mRNA) in the UUO group was significantly reduced (each p < 0.01). Prohibitin expression in the GA group was markedly increased when compared with that in the UUO (p < 0.01). The expression of TGF-β1 (protein and mRNA), protein expressions of Col-IV, fibronectin, α-SMA and cleaved Caspase-3, ROS generation and cell apoptosis index in the UUO group were markedly higher than those in the SHO group (all p < 0.01), and their expressions in the GA group were markedly down-regulated compared to those in the UUO group (all p < 0.01, respectively). The protein expression of prohibitin was negatively correlated with the RIF index, protein expression of TGF-β1, Col-IV, fibronectin, α-SMA or cleaved Caspase-3, ROS generation and the cell apoptosis index (each p < 0.01). In conclusion, lower expression of prohibitin is associated with the RIF, and ATRA treatment is associated with increased prohibitin, which can prevent the progression of RIF.     

阿苯达唑对人结肠癌SW480细胞增殖、凋亡及Bcl-2表达的影响

目的观察阿苯达唑(Albendazole,ABZ)对人结肠癌SW480细胞增殖、凋亡及其对Bcl-2表达的影响,并探讨其作用机制。方法用不同终浓度的ABZ(0.5、1.0、2.0及4.0 mg/ml)处理SW480细胞24、48、72 h,设对照组(ABZ浓度为0 mg/ml),CCK-8法检测ABZ对SW480细胞增殖活力的影响,并计算增殖抑制率及IC50。用不同终浓度的ABZ(1.0、2.0 mg/ml)处理SW480细胞,设对照组(ABZ浓度为0 mg/ml),流式细胞术检测细胞凋亡率,RT-PCR及Western blot检测Bcl-2 mRNA及蛋白的表达。结果与对照组比较,0.5、1.0、2.0及4.0 mg/ml ABZ处理组A值均明显降低(P﹤0.05),随着作用浓度的增加及作用时间的延长,抑制作用逐渐增强,且呈时间-剂量依赖性,2.0 mg/ml ABZ处理组24、48、72 h的IC50值分别为3.18、1.96和1.03 mg/ml;与对照组比较,1.0、2.0 mg/mlABZ处理组细胞凋亡率均明显增加(P﹤0.05),Bcl-2 mRNA及蛋白的表达均明显降低(P﹤0.05)。结论 ABZ能抑制结肠癌SW480细胞的增殖,并显著促进细胞凋亡,其作用机制可能与下调Bcl-2表达有关。     

短暂前脑缺血再灌注对大鼠海马脑区脑源性神经营养因子蛋白及mRNA表达的影响

目的探讨短暂前脑缺血再灌注(transient forebrain ischemia-reperfusion,I/R)对脑源性神经营养因子(brainderived neurotrophic factor,BDNF)蛋白及mRNA表达的影响,为进一步探索大鼠海马CA1区神经元损伤机制提供新的思路。方法将雄性SD大鼠随机分为control组、sham组和I/R组,利用Western blot和荧光定量PCR分析I/R后大鼠BDNF蛋白及mRNA表达的变化;染色质免疫共沉淀(chromatin immunoprecipitation,ChIP)试验检测I/R后大鼠BDNF基因启动子上H3K27的乙酰化水平。结果与control组相比,sham组大鼠CA1和CA3区BDNF蛋白和mRNA表达差异无统计学意义(P>0.05)。与sham组相比,I/R组大鼠CA1区BDNF蛋白表达显著下降(P<0.001),而CA3区BDNF蛋白表达增高(P<0.05);I/R组大鼠CA1区BDNF mRNAⅠ、Ⅱ和Ⅵ的表达均显著增高(P<0.01),而mRNAⅣ的表达显著下降(P<0.01),在CA3区4种mRNA均显著增高(P<0.01)。与sham组相比,I/R组大鼠CA1区BDNF启动子4的H3K27乙酰化水平显著下降(P<0.001),而CA3区BDNF启动子区域H3K27乙酰化水平增高(P<0.01)。结论I/R诱导大鼠海马CA1区BDNF蛋白及mRNA表达降低,并改变了BDNF基因启动子区乙酰化水平,为进一步研究BDNF表达降低引起神经元死亡的机制提供了新的方向。     

Apoptosis Signaling Is Altered in CD4(+)CD25(+)FoxP3(+) T Regulatory Lymphocytes in Pre-Eclampsia

The aim of our study was to estimate the surface expressions of CD95 (APO-1/Fas) antigen and the intracellular expressions of anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bax in CD4(+)CD25(+)FoxP3(+) T regulatory lymphocytes (Tregs) as well as the percentage of CD8(+)CD28(+) T cytotoxic cells in peripheral blood of patients with pre-eclampsia in comparison with healthy pregnant women in the third trimester of physiological pregnancy. Twenty-four women with pre-eclampsia and 20 normal third trimester pregnant women were included in the study. The lymphocytes were isolated from peripheral blood samples and labeled with monoclonal antibodies. The expressions of surface antigens and intracellular proteins were estimated using flow cytometry. The population of CD4(+)CD25(+)FoxP3(+) Treg cells was significantly lower in peripheral blood of patients with pre-eclampsia when compared to normal third trimester pregnant women. The percentages of CD4(+)CD25(+)FoxP3(+) Treg cells that express Bcl-2 protein were significantly lower in peripheral blood of patients with pre-eclampsia when compared to healthy pregnant women, whereas the percentages of CD4(+)CD25(+)FoxP3(+) Treg cells with the expressions of Bax protein did not differ in both groups. Moreover, the mean fluorescence intensity (MFI) of Bcl-2 protein in CD4(+)CD25(+)FoxP3(+) Treg cells was significantly lower and MFI of Bax protein significantly higher in pre-eclampsia when compared to the control group. The percentage of CD8(+)CD28(+) T cells did not differ in both studied groups but MFI of CD28 antigen on T CD8(+) cells was significantly higher in pre-eclampsia when compared to the control group. The obtained results suggest that the deficit of CD4(+)CD25(+)FoxP3(+) Treg lymphocytes which is observed in pre-eclampsia may be associated with altered apoptosis signaling in Tregs.     

Atrazine Causes Autophagy- and Apoptosis-Related Neurodegenerative Effects in Dopaminergic Neurons in the Rat Nigrostriatal Dopaminergic System

Atrazine (2-chloro-4-ethytlamino-6-isopropylamine-1,3,5-triazine; ATR) is widely used as a broad-spectrum herbicide. Animal studies have demonstrated that ATR exposure can cause cell death in dopaminergic neurons. The molecular mechanisms underlying ATR-induced neuronal cell death, however, are unknown. In this study, we investigated the autophagy and apoptosis induced by ATR in dopaminergic neurons in vivo. Wistar rats were administered with ATR at doses of 10, 50 and 100 mg/kg body weight by oral gavage for three months. In terms of histopathology, the expression of autophagy- and apoptosis-related genes as well as proteins related to the Beclin-1/B-cell lymphoma 2 (Bcl-2) autophagy and apoptosis pathways were examined in the rat nigrostriatal dopaminergic system. We observed degenerative micromorphology indicative of neuronal apoptosis and mitochondrial autophagy by electron microscopy in ATR-exposed rat striatum. The rat ventral mesencephalon in the ATR-exposed groups also showed increased expression of Beclin-1, LC3-II, Bax and Caspase-9, and decreased expression of tyrosine hydroxylase (TH), Bcl-xl and Bcl-2. These findings indicate that ATR may induce autophagy- and apoptosis-related changes in doparminergic neurons. Furthermore, this induction may be regulated by the Beclin-1 and Bcl-2 autophagy and apoptosis pathways, and this may help to better understand the mechanism underlying the neurotoxicity of ATR.