转化生长因子-β1对脊髓损伤后神经细胞凋亡的影响

 目的 探讨转化生长因子(Transforming growth factor-β1,TGF-ββ1)对大鼠脊髓损伤后神 经细胞凋亡及神经动能恢复的影响。方法 采用改良 Allen爷s撞击法制作脊髓损伤大鼠模型, 根据干预 方式不同随机分为对照组、模型组、TGF-β1治疗组(渗透微泵持续蛛网膜下腔泵入 1μg/h TGF-β1)、 TGF-β1抗体组(渗透微泵持续蛛网膜下腔泵入 1μg/h TGF-β1中和抗体), 按设定的不同时间点随机处死各组的实验动物, 取材。应用 TUNEL法、RT-PCR、Western blot和免疫组织化学染色分别检测不同组 别在神经细胞凋亡, 脊髓组织细胞中 TGF-β1和 Fas的 mRNA及蛋白质表达差异。通过 BBB运动功能 评分法评估大鼠后肢运动功能恢复情况。结果 脊髓损伤后 TGF-β1和 Fas表达时间依赖性增加, Fas 表达 24h达高峰, TGF-β1表达 7d达高峰。脊髓损伤后神经细胞凋亡增加, 其中 8h神经元凋亡明显, 7 d神经胶质细胞凋亡明显。局部应用 TGF-β1, 可显著下调损伤脊髓组织 Fas表达, 减少 8h和 7d时神 经元凋亡及神经胶质细胞凋亡数量, BBB运动功能评分结果显示, TGF-β1治疗组大鼠后肢运动功能明显改善(P约0.01)。结论 脊髓损伤部位应用 TGF-β1可抑制 Fas mRNA及蛋白质的表达, 减少脊髓损伤 部位神经细胞的凋亡, 有利于促进脊髓神经功能的恢复。     

大剂量甲基强的松龙对大鼠急性脊髓损伤后神经细胞Bcl-2表达及细胞凋亡的影响

目的：观察大剂量甲基强的松龙（MP）治疗对大鼠急性脊髓损伤（ASCI）后神经细胞凋亡及凋亡基因Bcl-2的影响。方法：选取48只雌性SD大鼠随机等分为2组,对照组与治疗组,按Nystrom法制备大鼠急性脊髓损伤模型。治疗组伤后30min经腹膜腔注入MP30mg／kg,以后每小时腹膜腔注入MP5．4mg／kg,维持24h;对照组应用生理盐水替代MP,处理方法同治疗组。两组分别于伤后4、8h及1、3、7、14d灌注固定后取材。免疫组织化学检测损伤段脊髓内Bcl-2蛋白表达,TUNEL检测细胞凋亡,染色结果应用图像分析仪进行半定量分析。结果：大鼠ASCI后4h即可见脊髓内TUNEL阳性细胞,8h表达达高峰,此后表达量逐渐下降,14d时仍可见少量阳性细胞。凋亡相关蛋白Bcl-2在伤后4h即可见表达,伤后1d达高峰,伤后14d仍有表达,与对照组相比,治疗组伤后8h、1d和3d时凋亡细胞数减少有统计学意义,伤后8h和1d Bcl-2蛋白表达增高有统计学意义。结论：大剂量甲基强的松龙治疗可抑制大鼠ASCI后神经细胞凋亡,并增加凋亡相关蛋白Bcl-2的表达：     

大剂量甲基强地松龙对大鼠脊髓损伤后iNOS表达及细胞凋亡的影响

目的：探讨大鼠脊髓损伤后应用大剂量甲基强地松龙(MP)对诱导型一氧化氮合酶(iNOS)表达及细胞凋亡的影响。方法：成年大鼠随机分为脊髓损伤后应用大剂量甲基强的松龙治疗组(A组)和应用生理盐水对照组(B组)，损伤后不同时间点(4h、8h、1d、3d、7d、14d、21d)按Tarlov标准评价大鼠双后肢神经功能恢复情况，然后处死。用HE染色观察损伤脊髓组织病理变化，用免疫组化染色检测iNOS阳性细胞，原位末端标记法(TUNEL法)标记凋亡细胞。结果：HE染色镜检发现脊髓组织病理学改变A组明显轻于B组。A、B两组均发现凋亡细胞及iNOS表达，神经细胞凋亡指数及iNOS表达均为B组＞A组(P＜0．01)。结论：大剂量甲基强的松龙能抑制大鼠脊髓损伤后iNOS表达及细胞凋亡。     

FTY720对大鼠急性脊髓损伤后神经功能恢复的影响及相关机制

目的:观察FTY720对大鼠急性脊髓损伤(ASCI)后神经功能的影响,并探讨其相关机制。方法:168只雌性SD大鼠,随机分成A、B、C三组,每组56只,A组(假手术组)大鼠麻醉后仅切除T9椎板,不打击脊髓,缝合后立即以0.3ml生理盐水灌胃。B、C组采用Allen′s法制作T9脊髓损伤模型,B组(对照组)以0.3ml生理盐水灌胃,C组(治疗组)以FTY720按3mg/kg生理盐水稀释至0.3ml灌胃。每组取8只大鼠分别于术后1d、3d、7d、14d、21d行斜板试验及BBB评分。分别于术后6h、12h、24h、48h、72h、7d、21d处死大鼠,每个时间点每组8只,取损伤段(A组取相应部位)脊髓行超薄切片,HE染色观察各组脊髓坏死情况、炎细胞浸润情况、胶质瘢痕形成情况及脊髓空洞大小,并计数各组术后12h淋巴细胞数、术后12h与72h炎性细胞、术后7d胶质瘢痕区细胞,计算伤后21d脊髓空洞面积与脊髓面积比值;取术后6h、12h、24h、72h的切片行SP免疫组化染色观察caspase-3表达及Tunel染色观察细胞凋亡情况,计算相应时间点免疫组化染色阳性细胞比值和凋亡指数。所有数据以SPSS 13.0进行统计学分析。结果:B、C两组各时间点斜板实验及BBB评分均较A组同时间点差(P<0.05),在术后1d时B、C组之间无显著性差异(P>0.05),术后3d、7d、14d、21d时C组优于B组(P<0.05)。HE染色结果显示A组各时间点脊髓形态正常;B、C组脊髓术后6h可见脊髓内出血、血肿形成,术后12h~48h脊髓进行性水肿、损伤中心区出现液化坏死,伴有炎细胞浸润,以中性粒细胞、淋巴细胞、单核细胞为主,至术后72h,损伤中心区形成无组织结构空洞,空洞周围有大量炎细胞浸润,以小胶质细胞/单核细胞为主;术后12h及72h,B组炎细胞浸润程度明显重于C组(P<0.05),术后12h C组淋巴细胞浸润程度相对B组明显减少(P<0.05),术后7d,脊髓水肿减轻,空洞周围形成胶质瘢痕,胶质瘢痕细胞计数B组明显大于C组(P<0.05),术后21d脊髓空洞形成,脊髓空洞比值B组明显大于C组(P<0.05)。SP免疫组化染色和Tunel染色结果显示A组各时间点几乎见不到caspase-3和细胞凋亡表达阳性细胞,B、C组脊髓损术后6h即可见凋亡细胞,到术后24h达高峰,而后随术后时间延长而逐渐减弱,但是仍然保持在较高水平;caspase-3表达与细胞凋亡同步,各时间点C组caspase-3表达阳性细胞比值和细胞凋亡指数均显著低于B组(P<0.05)。结论:FTY720可以显著改善大鼠ASCI后神经功能,其可能是通过抑制脊髓损伤后的炎症反应,减少caspase-3的表达及神经细胞凋亡,从而减轻脊髓继发性损伤。     

大鼠脊髓损伤中的细胞凋亡及甲基强的松龙的干预作用

目的：探讨脊髓损伤（SCI）继发损伤机制,研究损伤脊髓细胞的凋亡及其意义,观察甲基强的松龙（MP）对细胞凋亡的影响。方法：使用改良Allen法制作大鼠急性SCI模型,实验分3组,假损伤（脊髓未受打击）,损伤组及MP治疗组,采用HE,荧光Hoechst 33342,TUNEL(末端脱氧核苷转移酶介导的脱氧尿苷三磷酸生物素缺口末端标记技术）等技术观察SCI后4h,8h,3d,7d,14d,21d及28d时损伤中心及邻近节段脊髓细胞的凋亡,治疗组损伤后30min给予大剂量MP,比较MP治疗组与损伤组脊髓细胞凋亡的变化,同时平行观察大鼠神经学和组织学恢复情况及两组神经丝蛋白（NF）含量的变化。结果：假损伤组各检测方法未见脊髓细胞凋亡,损伤组大鼠急性SCI后1d开始出现脊髓细胞凋亡,3d达高峰,自损伤中心向头尾端递减分布,持续21d,MP治疗组在伤后3d及7d凋亡脊髓细胞较损伤组显著减少,神经学恢复及组织学评分较损伤组有显著性提高,结论：凋亡是SCI后脊髓神经元死亡的一种重要方式,在继发性损伤中起极为重要的作用。MP的治疗作用可能与其干预SCI后细胞凋亡有关。     

17β-雌二醇对大鼠脊髓损伤后神经保护作用的研究

目的：探讨17β-雌二醇（E2）对大鼠脊髓损伤（SCI）后的神经保护作用及其机制。方法：应用改良的Allen′s重物打击法建立大鼠急性脊髓损伤模型,将大鼠随机分为两组：A组（PBS对照组）和B组（E2治疗组）,每组42只,B组造模成功后15min及24h腹腔注射E2（4.0mg/kg,以PBS溶解）,A组在相同时间给予等量无菌PBS。分别于伤后7d、14d、21d及28d,应用改良Tarlov评分法和Rivlin斜板试验评价大鼠脊髓神经功能恢复情况。于伤后6h、24h、3d、7d、14d及28d时处死动物,以损伤部位为中心取材,HE染色观察脊髓组织病理变化,TUNEL法染色检测细胞凋亡,免疫组化染色检测caspase-3、Bcl-2的表达情况。结果：从伤后14d起,B组Tarlov评分和斜板试验角度与A组相比差异有显著性（P〈0.01）。TUNEL法检测表明,大鼠SCI后存在细胞凋亡,3d时达高峰,与caspase-3的表达基本一致,B组伤后24h、3d及7d时凋亡细胞比率显著低于A组（P〈0.01或P〈0.05）。免疫组化结果显示B组伤后24h、3d、7d、14d及28d时caspase-3表达低于A组（P〈0.01或P〈0.05）,而Bcl-2表达高于A组（P〈0.01或P〈0.05）。结论：E2能促进大鼠SCI后的神经功能恢复,具有一定的神经保护作用;E2可能是通过减少SCI后继发性细胞凋亡的机制发挥作用的。     

脊髓损伤模型中神经细胞凋亡及Fas抗原和Bax蛋白在神经细胞中的表达

目的：观察脊髓损伤模型中Fas抗原及Bax蛋白在时间和空间上的表达特点以及脊髓损伤后组织形态及超微结构变化特点，探讨SCI后神经细胞的病理改变机理。方法：Wistar大鼠按Allen法建立脊髓损伤模型，分别在术后1h、8h、1d、2d、3d、7d，处死取材，每个时相点5只动物。分别在每只大鼠脊髓损伤中心区，损伤区头侧和尾侧3mm、5mm、7mm、10mm、13mm横截面处各切取3片组织。分别作Bax蛋白、Fas抗原免疫组化，HE染色，电镜下观察细胞超微结构的改变。结果：Fas抗原在损伤后8－24h，损伤区头、尾侧7mm处出现表达高峰。Bax蛋白在损伤后2－3d，损伤区头、尾侧7mm处出现高峰。电镜观察：损伤区死亡细胞呈坏死典型表现，而在非损伤区死亡细胞呈凋亡的典型表现。结论：SCI后急性损伤主要表现为细胞的坏死，继发损伤主要由细胞的凋亡引起。同时证实了凋亡的两条途径：由Fas抗原参与的死亡受体途径及Bax参与的线粒体途径均参与了SCI后细胞凋亡的病理过程。     

大鼠急性脊髓损伤后Caspase-3、Cathepsin B的表达

[目的]研究大鼠急性脊髓损伤后Caspase-3、Cathepsin B的表达,并初步探讨Caspase-3、Cathepsin B在脊髓损伤后表达的意义.[方法]将78只成年健康SD大鼠按Nystrom法建立大鼠脊髓(T8 、T9)急性压迫损伤模型, HE染色观察脊髓组织病理学变化,免疫组化测定各时间点Cathepsin B、Caspase-3 的表达变化,原位末端脱氧核糖核酸转移酶介导的脱氧尿苷三磷酸(dUTP) 标记法(TUNEL 法) 检测神经细胞的凋亡水平.[结果]免疫组化结果显示正常及假手术组大鼠脊髓神经细胞中Caspase-3,Cathepsin B,TUNEL阳性细胞较少;在脊髓损伤后3 d Cathepsin B阳性细胞数明显增多,5 d达高峰,7 d未见明显衰减.Caspase-3阳性细胞数在脊髓损伤后8 h明显增多,3 d达高峰,7 d表达减弱.TUNEL阳性细胞数也在8 h明显增多,3 d达高峰,7 d表达减弱.Cathepsin B阳性细胞形态及表达的部位均与Caspase-3阳性细胞、TUNEL阳性细胞差别较大.[结论]Caspase-3参与了脊髓损伤细胞凋亡的调节,Cathepsin B则可能通过炎性细胞为媒介参与了脊髓继发性损伤.     

白介素-1受体拮抗剂对大鼠急性脊髓损伤后神经细胞凋亡和caspase-3表达的影响

目的：观察白介素-1受体拮抗剂（IL—1Ra）对脊髓损伤（SCI）后继发性神经细胞凋亡和caspase-3表达的影响。方法：60只SD大鼠，随机分为假手术组、脊髓损伤组、IL-1Ra治疗组和生理盐水对照组，每组15只。采用Allen’s法建立大鼠急性SCI动物模型．IL—1Ra治疗组和生理盐水对照组于SCI后立即硬膜下腔内分别注射IL-1Ra（10μg／10μl）和等量生理盐水，于伤后24h以损伤为中心（假手术组取相应部位），切取长约8mm脊髓组织．用蛋白印迹法和免疫组化染色法检测caspase-3表达的变化：采用实时定量PCR法检测caspase-3mRNA的表达情况；用原位末端标记法（TUNEL）检测SCI后神经细胞凋亡情况。结果：SCI后24h，SCI组与假手术组比较受损伤的脊髓组织中caspase-3mRNA和蛋白表达水平均显著升高（P〈O．05），且TUNEL阳性细胞明显增多（P〈O．01）：IL—1Ra治疗组大鼠受损伤节段脊髓组织caspase-3表达及TUNEL阳性细胞数较生理盐水对照组）均明显减少（P〈O．01）。结论：IL-1Ra治疗可减少急性SCI后脊髓组织中caspase-3的表达和神经细胞凋亡的发生。     

bcl-xL基因转染对脊髓损伤半胱氨酸蛋白酶-3表达的影响

目的 探讨bcl—xL基因转染对大鼠脊髓损伤Caspase-3表达的影响和对神经细胞的保护作用。方法 制备大鼠胸段脊髓T8,9压迫损伤模型，随机分为2组：对照组．bcl—xL组，将阳离子脂质体质粒混合后直接注入大鼠损伤脊髓，伤后1、3和7d利用半定量逆转录-聚合酶链式反应（RT—PCR）和免疫组织化学检测bcl—xL和Caspase-3表达情况；TUNEL法检测细胞凋亡，观察对神经细胞的保护作用。结果 与对照组相比，bcl—xL组各时间段Caspase-3表达明显降低（P〈0．05），TUNEL阳性凋亡的神经细胞明显减少（P〈0．05）。结论 外源性bcl—xL基因体内转染在损伤脊髓的过度表达可减少脊髓不完全性损伤后凋亡，可能与其下调Caspase-3的有关。     

Caspase activation in neuronal and glial apoptosis following spinal cord injury in mice

The involvement of caspases in apoptosis after spinal cord injury (SCI) was investigated in adult mouse spinal cord after contusion. Sections of spinal cord were processed for staining 7 days after SCI with the fluorescent dye Hoechst 33342, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL), and immunostaining with an antibody (CM1) recognizing activated caspase-3. Caspase-3- and caspase-8-like enzyme activities were measured colorimetrically at 8 hours to 7 days after SCI using the specific substrates Asp-Glu-Val-Asp-p-nitroanilide and Ile-Glu-Thr-Asp-p-nitroanilide, respectively. Hoechst 33342 staining showed small, bright areas in fragmented nuclei. Double labeling with TUNEL plus immunostaining with cell type-specific markers identified TUNEL-positive neurons stained by anti-neuronal nuclear protein/neurons antibody, and TUNEL-positive oligodendrocytes stained by anti-cyclic nucleotide 3'-phosphohydrolase antibody. Double labeling with CM1 and cell-type specific markers similarly identified CM1-positive neurons and oligodendrocytes. Caspase-8-like enzyme activity was increased significantly on days 3 and 7 (p < 0.01), whereas caspase-3-like activity increased on day 7 (p < 0.01). Intraventricular injection of a nonspecific tetrapeptide caspase inhibitor or a specific tetrapeptide inhibitor of caspase-3 just after SCI reduced enzyme activity at 7 days. Apoptotic cells were identified with TUNEL staining in both neurons and oligodendrocytes in mice after SCI, which also showed activated caspase-3. Increased caspase-3- and caspase-8-like activity was detected in the injured spinal cord on days 3 and 7. Caspase protease activities may be involved in delayed neuronal and glial apoptosis after SCI.     

Apoptotic neuronal death following deep hypothermic circulatory arrest in piglets

BACKGROUND: Deep hypothermic circulatory arrest (DHCA), as used in infant heart surgery, carries a risk of brain injury. In a piglet DHCA model, neocortical neurons appear to undergo apoptotic death. Caspases, cytochrome c, tumor necrosis factor (TNF), and Fas play a role in apoptosis in many ischemic models. This study examined the expression of these factors in a DHCA piglet model. METHODS: Thirty-nine anesthetized piglets were studied. After cardiopulmonary bypass (CPB) cooling of the brain temperature to 19 degrees C, DHCA was induced for 90 min, followed by CPB rewarming. After separation from CPB, piglets were killed at 1, 4, 8, 24, and 72 h and 1 week. Caspase-8 and -3 activity, and concentrations of TNF-alpha, Fas, Fas-ligand, cytochrome c, and adenosine triphosphate (ATP) were measured in the neocortex by enzymatic assay and Western blot analysis. Caspase-8 and -3 activity and cell death were examined histologically. Significance was set at P < 0.05. RESULTS: In neocortex, damaged neurons were not observed in control (no CPB), rarely observed in CPB (no DHCA), and rarely observed in the DHCA 1-h, 4-h, and 1-week reperfusion groups. However, they were seen frequently in the DHCA 8-, 24-, and 72-h reperfusion groups. Although neuronal death was widespread 8-72 h after DHCA, cortical ATP concentrations remained unchanged from control. Both caspase-3 and -8 activities were significantly increased at 8 h after DHCA, and caspase-3 concentration remained elevated for as long as 72 h. Caspase-3 and -8 activity was also observed in damaged neocortical neurons. Cytosolic cytochrome c and Fas were significantly expressed at 1 h and 4 h after DHCA, respectively. Fas-ligand and TNF-alpha were not observed in any group. CONCLUSION: After DHCA, induction of apoptosis in the neocortex occurs within a few hours of reperfusion and continues for several days. Increased Fas, cytochrome c, and caspase concentrations, coupled with normal brain ATP concentrations and apoptotic histologic appearance, are consistent with the occurrence of apoptotic cell death.     

Apoptotic Neuronal Death following Deep Hypothermic Circulatory Arrest in Piglets

Background: Deep hypothermic circulatory arrest (DHCA), as used in infant heart surgery, carries a risk of brain injury. In a piglet DHCA model, neocortical neurons appear to undergo apoptotic death. Caspases, cytochrome c, tumor necrosis factor (TNF), and Fas play a role in apoptosis in many ischemic models. This study examined the expression of these factors in a DHCA piglet model.

Methods: Thirty-nine anesthetized piglets were studied. After cardiopulmonary bypass (CPB) cooling of the brain temperature to 19[degrees]C, DHCA was induced for 90 min, followed by CPB rewarming. After separation from CPB, piglets were killed at 1, 4, 8, 24, and 72 h and 1 week. Caspase-8 and -3 activity, and concentrations of TNF-[alpha], Fas, Fas-ligand, cytochrome c, and adenosine triphosphate (ATP) were measured in the neocortex by enzymatic assay and Western blot analysis. Caspase-8 and -3 activity and cell death were examined histologically. Significance was set at P < 0.05.

Results: In neocortex, damaged neurons were not observed in control (no CPB), rarely observed in CPB (no DHCA), and rarely observed in the DHCA 1-h, 4-h, and 1-week reperfusion groups. However, they were seen frequently in the DHCA 8-, 24-, and 72-h reperfusion groups. Although neuronal death was widespread 8-72 h after DHCA, cortical ATP concentrations remained unchanged from control. Both caspase-3 and -8 activities were significantly increased at 8 h after DHCA, and caspase-3 concentration remained elevated for as long as 72 h. Caspase-3 and -8 activity was also observed in damaged neocortical neurons. Cytosolic cytochrome c and Fas were significantly expressed at 1 h and 4 h after DHCA, respectively. Fas-ligand and TNF-[alpha] were not observed in any group.     

过度训练可部分通过上调TLR4的表达激活死亡受体凋亡通路诱导大鼠肾小管上皮细胞凋亡

目的：观察过度训练大鼠肾组织TLR4、Fas及Caspase-8表达的变化,探讨TLR4在死亡受体凋亡通路中的作用。方法：将48只雄性SD大鼠按随机数字表法分为对照组（CN）、力竭运动组（ES）、山莨菪碱干预组（AD）。CN组为安静对照;ES组又根据力竭后恢复时间分为力竭后即刻（ESI）、力竭后6 h（ES 6 h）和力竭后24 h（ES 24 h）;AD组于力竭运动前20 min腹腔注射山莨菪碱10 mg/kg后进行力竭运动,分为AD 6 h和AD 24 h组。采用大鼠游泳至力竭建立过度训练模型。采用Western印记测定肾组织TLR4和Fas的表达,免疫组织化学法检测肾组织Caspase-8的表达,并分别对TLR4与Fas、Caspase-8、肾组织细胞凋亡率进行相关性分析。结果：Western印记测定结果显示,过度训练大鼠肾组织TLR4及Fas的表达于力竭后即刻、6 h及24 h逐渐增高,均显著高于对照组（P〈0.05）。免疫组化显示,过度训练大鼠肾组织Caspase-8的表达于力竭后即刻、6 h及24 h逐渐增强,均显著高于对照组（P〈0.05）。过度训练大鼠肾组织TLR4与Fas、Caspase-8和细胞凋亡率的表达均呈正相关性（r=0.848,P〈0.05;r=0.916,P〈0.05;r=0.95,P〈0.05）。用山莨菪碱干预后,过度训练引起的肾组织TLR4、Fas及Caspase-8的过度表达均被显著抑制（均P〈0.05）。结论：过度训练可通过上调TLR4强化死亡受体凋亡通路,进而诱导大鼠肾小管上皮细胞凋亡。     

FasL, Fas, and death-inducing signaling complex (DISC) proteins are recruited to membrane rafts after spinal cord injury

The Fas/CD95 receptor-ligand system plays an essential role in apoptosis that contributes to secondary damage after spinal cord injury (SCI), but the mechanism regulating the efficiency of FasL/Fas signaling in the central nervous system (CNS) is unknown. Here, FasL/Fas signaling complexes in membrane rafts were investigated in the spinal cord of adult female Fischer rats subjected to moderate cervical SCI and sham operation controls. In sham-operated animals, a portion of FasL, but not Fas was present in membrane rafts. SCI resulted in FasL and Fas translocation into membrane raft microdomains where Fas associates with the adaptor proteins Fas-associated death domain (FADD), caspase-8, cellular FLIP long form (cFLIPL ), and caspase-3, forming a death-inducing signaling complex (DISC). Moreover, SCI induced expression of Fas in clusters around the nucleus in both neurons and astrocytes. The formation of the DISC signaling platform leads to rapid activation of initiator caspase-8 and effector caspase-3, and the modification of signaling intermediates such as FADD and cFLIP(L) . Thus, FasL/Fas-mediated signaling after SCI is similar to Fas expressing Type I cell apoptosis.     

Expression and effect of Caspase-3 in neurons after tractive spinal cord injury in rats

Thereisextensiveapoptosisafterinjuryofthecentralnervoussystem.Apoptosisisarathercomplicatedprocess,involvingwithsubtleregulationsofmacromolecules,likecellreceptor,adaptormolecule,proteaseandinhibitor.Among them,Caspaseproteasefamilyisthecoreinthe processo…     

血清抗精子抗体阳性对青春期雄性大鼠睾丸组织及睾丸生殖细胞中Fas/Fas-L凋亡途径的影响

目的:通过人工免疫雄性大鼠获得抗精子抗体(AsAb)介导的血清AsAb阳性的免疫性不育大鼠动物模型,观察AsAb对青春期大鼠睾丸组织及睾丸生殖细胞中Fas/Fas-L凋亡途径的影响。方法:5周龄(青春期)雄性Wistar大鼠30只,其中10只处死,取精子制备精子悬液免疫大鼠,余20只动物随机分为实验组(10只)和对照组(10只),4周后摘取睾丸。光镜观察睾丸组织改变,免疫组化法检测Fas、Fas-L和Caspase-3蛋白的表达。结果:实验组睾丸组织切片呈凋亡样改变,实验组Fas、Fas-L及Caspase-3蛋白的OD值(176.97±4.58,187.52±7.76,157.65±7.38)较对照组(161.87±5.37,150.27±8.65,120.37±6.76)显著增高(P<0.01)。结论:同种精子免疫大鼠,可成功制作AsAb介导的免疫性不育模型;AsAb影响雄性大鼠的生育力,其机制可能与Fas/Fas-L凋亡途径中Fas、Fas-L和Caspase-3蛋白的表达升高有关。     

Influence of propofol on neuronal damage and apoptotic factors after incomplete cerebral ischemia and reperfusion in rats: a long-term observation

BACKGROUND: Propofol reduces neuronal damage from cerebral ischemia when investigated for less than 8 postischemic days. This study investigates the long-term effects of propofol on neuronal damage and apoptosis-related proteins after cerebral ischemia and reperfusion. METHODS: Male Sprague-Dawley rats were randomly assigned as follows: group 1 (n = 32, control): fentanyl and nitrous oxide-oxygen; group 2 (n = 32, propofol): propofol and oxygen-air. Ischemia (45 min) was induced by carotid artery occlusion and hemorrhagic hypotension. Pericranial temperature and arterial blood gases were maintained constant. After 1, 3, 7, and 28 postischemic days, brains were removed, frozen, and sliced. Hippocampal eosinophilic cells were counted. The amount of apoptosis-related proteins Bax, p53, Bcl-2, and Mdm-2 and neurons positive for activated caspase-3 were analyzed. RESULTS: In propofol-anesthetized rats, no eosinophilic neurons were detected, whereas in control animals, 16-54% of hippocampal neurons were eosinophilic (days 1-28). In control animals, the concentration of Bax was 70-200% higher after cerebral ischemia compared with that in animals receiving propofol over time. Bcl-2 was 50% lower in control animals compared with propofol-anesthetized rats during the first 3 days. In both groups, a maximal 3% of the hippocampal neurons were positive for activated caspase-3. CONCLUSIONS: These data show sustained neuroprotection with propofol. This relates to reduced eosinophilic and apoptotic injury. Activated caspase-3-dependent apoptotic pathways were not affected by propofol. This suggests the presence of activated caspase-3-independent apoptotic pathways.     

甲泼尼龙预干预脊髓缺血再灌注损伤对Caspase-3表达的影响

目的 探讨甲泼尼龙(MP)预处理脊髓缺血再灌注损伤(SCII)对Caspase-3的影响.方法 取健康纯种成年雄性SD大鼠120只,随机分成3组:对照组(A组)只暴露腹主动脉,不做模型;SCII组(B组)夹闭腹主动脉30 min后松开,再灌注3 h建立SCII模型,然后处死大鼠,取腰段脊髓标本;MP组(C组)于建立SCII模型前30 min尾部静脉注射MP(30 mg/kg).通过HE染色观察损伤节段脊髓病理形态学变化,用免疫组织化学染色方法观察脊髓组织Casepase-3的表达.结果 A组神经元细胞轮廓清晰、极性存在、核圆、核仁清楚,尼氏体呈网状均匀排列于细胞核周围,胞浆均匀深染,组织结构完整清楚,无中性粒细胞浸润,无出血、水肿等异常现象;B组神经元细胞肿胀,数目减少,极性变钝,核仁轻度萎缩,尼氏体呈颗粒状、淡染,组织中有中性粒细胞浸润;C组部分神经元细胞轻度水肿,核仁尚清,组织中未见中性粒细胞浸润.B组脊髓组织内Caspase-3大量表达,与对照组比较差异有统计学意义(P<0.05);C组脊髓细胞内Caspase-3轻度增加,与B组比较差异有统计学意义(P<0.05).结论 MP预处理可降低大鼠SCII中Caspase-3的表达,预防性应用MP能减轻SCII,保护脊髓神经功能.

Abstract：

Objective To investigate the effect of methylprednisolone (MP) pretreatment of ischemia-reperfusion injury of spinal cord (SCII) on expression of caspase-3 in rats. Methods One hundred and twenty healthy, purebred, adult male SD rats were randomly divided into 3 equal groups (n = 40).Croup A was a normal one in which only the abdominal aorta was exposed without establishing an injury model. Croup B was an SCII model in which the abdominal aorta was first obstructed for 30 minutes and then relaxed and next reperfused. After reperfusion for 3 hours, the rats were killed to harvest samples of lumbar spinal cord. Group C was an MP pretreatment one in which tail intravenous injection of MP (30mg/kg) was conducted 30 minutes before establishment of an SCII model. Pathological changes of the injured spinal cord were observed by HE staining, and expressions of caspase-3 in the spinal cord tissue were observed by immunohistochemical staining. Results In group A, the outlines of neuronal cells were clear with polarity and a round nucleus. Ramified Nissl bodies were evenly arranged around the nucleus. Cytoplasm was stained uniformly dark. Organizational structure was integrated and clear without neutrophile granulocyte infiltration,hemorrhage or edema. In group B, neuronal cells were swelling and decreased in quantity, with blunt polarity and mild atrophy of nucleolus. Cranuloses of Nissl bodies were observed with pale staining. There was neutrophile granulocyte infiltration. In group C, mild edema was observed in part of neuronal cells, nucleoli were still clear and there was no neutrophile granulocyte infiltration. Caspase-3 was highly expressed in the spinal cord tissue in group B, with significant differences compared with group A ( P < 0. 05). Expression of caspase-3 in the spinal cord was slightly increased in group C, but the difference was significant compared with group B (P < 0. 05) . Conclusion Since MP pretreatment can reduce expression of caspase-3 in SCII rats, preventive use of MP may alleviate SCII and help protect neural function of the spinal cord.