泛素碳端水解酶L1在邻苯二甲酸二丁酯诱导大鼠睾丸发育异常中的表达变化

目的:利用邻苯二甲酸二丁酯(DBP)诱导大鼠睾丸发育异常,验证泛素碳端水解酶L1(UCHL1)在异常睾丸与正常大鼠睾丸中的差异表达,以进一步探讨UCHL1在DBP导致的大鼠睾丸发育异常中的作用机制。方法:孕SD大鼠40只,妊娠14~18d,随机分为2组,实验组和对照组分别予DBP 800mg/(kg·d)、大豆油5ml/d灌胃,孕期第19d(GD19)和出生后22d(PND22),分别取胎鼠及仔鼠睾丸,定量定位分析UCHL1在胎鼠及仔鼠睾丸中的表达变化。结果:GD19,UCHL1在实验组的相对表达量为0.075±0.02(n=10),对照组为0.150±0.02(n=10),2组差异有显著性(P<0.05),UCHL1在实验组中比正常对照组下降50%;而PND22,UCHL1于实验组隐睾睾丸中的相对表达量为0.344±0.03(n=10),实验组非隐睾睾丸中为0.326±0.02(n=10),对照组为0.322±0.02(n=10),3组间无明显统计学差异(P>0.05)。UCHL1主要定位于睾丸发育时期的精原细胞,初级精母细胞和次级精母细胞的胞质与胞核中。结论:DBP在染毒期间影响了睾丸生精细胞UCHL1的表达,影响了泛素-蛋白酶体系的平衡,从而导致生精小管的变薄,各层生精细胞数目减少的睾丸发育异常现象。     

青春期前邻苯二甲酸二丁酯持续暴露对大鼠睾丸发育的影响

目的:研究青春期前邻苯二甲酸二丁酯(DBP)持续暴露对睾丸发育的影响。方法:21日龄断乳青春期前雄性SD大鼠随机分为对照组(n=24)和实验组(n=54),每日分别用玉米油或DBP玉米油溶液灌胃,DBP暴露剂量分别为50mg/(kg.d)(低剂量组,n=18)、200mg/(kg.d)(中剂量组,n=18)和600mg/(kg.d)(高剂量组,n=18),各组动物持续暴露14、21、28d后(即PND35,PND42和PND49)断颈处死。记录大鼠体重变化,检测睾丸重量和体积、附属性器官重量及附睾精子,化学发光免疫分析法检测血清睾酮含量,苏木精-伊红染色观察睾丸组织形态学变化,测量生精小管平均直径及进行睾丸活检评分。结果:低剂量组PND35少量生精小管生精细胞排列紊乱,PND42和PND49睾丸、附属性器官发育及生精功能正常;中剂量组PND35和PND42生精细胞排列紊乱、数目减少,PND49生精小管内可见各级生精细胞及精子,睾丸未见萎缩,附属性器官发育正常;高剂量组大鼠体重增长减缓,血清睾酮水平低下,睾丸生精小管变性萎缩,生精上皮发育阻滞,生精细胞大量凋亡坏死,青春期大鼠睾丸萎缩,无精子,附睾、前列腺和精囊等附属性器官发育迟缓。结论:青春期前DBP持续暴露可损害睾丸组织发育和正常生精功能形成,其毒性效应具有剂量依赖性,高剂量DBP持续暴露引起的睾丸毒性在青春期前发育过程中不可修复,而低中剂量暴露引起的睾丸毒性在PND49之前可完全或部分逆转性恢复。     

单侧隐睾大鼠对侧睾丸的损害与Bcl-2和Bax基因表达

目的:探讨单侧隐睾大鼠对侧睾丸生精细胞凋亡与Bcl-2/Bax基因表达的关系。方法:20只健康SD雄性大鼠(22日龄)随机分成隐睾组和对照组,每组10只。通过手术建立单侧隐睾动物模型。术后90 d取对侧睾丸,采用原位缺口末端标记(TUNEL)法检测生精细胞凋亡,免疫组化SP法检测Bcl-2/Bax基因表达。结果:与对照组相比,隐睾组对侧睾丸生精细胞凋亡显著增多(P<0.01),重量显著减轻(P<0.01),Bax表达显著升高(P<0.01),Bcl-2表达显著降低(P<0.01)。凋亡细胞主要是初级精母细胞和圆形精子细胞。结论:单侧隐睾大鼠对侧睾丸的生精细胞凋亡增多与Bcl-2基因表达降低、Bax基因表达升高密切相关。细胞内Bc l-2/Bax比值是影响生精细胞凋亡的重要因素之一。     

隐睾及睾丸固定术后对大鼠生精能力的影响

目的 观察隐睾及睾丸固定术后对睾丸生精能力的影响.方法 通过手术方法对80只SD大鼠制作单侧隐睾模型,随机分为10组,其中4组(每组10只)于隐睾术后7、14 d切取患侧睾丸组织,6组于隐睾术后7、14d行睾丸固定术,分别于术后2、4、6周取材.将所取得的睾丸组织称重后行流式细胞仪检测其细胞凋亡率和各生精细胞百分比以及组织中B淋巴细胞/白血病-2( bcl-2)和bax基因表达量.结果 隐睾睾丸重量明显下降,隐睾组1C细胞(7d组:10.61 ±1.10,14d组:11.79 ±0.91)较对照组降低(16.48±1.60,P＜0.05)、4C细胞也明显降低,而2C细胞(7d组:40.41±2.93,14 d组:51.41±6.45)较对照组增加(30.17±3.24,P＜0.05).隐睾各组生精细胞凋亡率(7d组:14.9±1.26,14 d组:6.90±0.96)高于正常对照组(2.50±0.44,P＜0.01),而睾丸复位固定术后各组生精细胞凋亡率均下降(P＜0.05).隐睾7、14 d睾丸中bc1-2蛋白表达量(7d组:4.68±0.47;14 d组:5.66 ±0.71)较对照组(7.47±1.01)降低而bax蛋白表达量(7d组:8.27±1.08;14 d组:6.26±0.21)较对照组(5.82 ±0.47,P＜0.05)升高,睾丸固定术后各组bcl-2蛋白表达量升高而bax蛋白表达量降低(P＜0.01).结论 隐睾可以使睾丸生精细胞凋亡增加,睾丸复位固定术后,睾丸生精功能可部分或全部恢复,其恢复程度和隐睾时间长短有关;bcl-2和bax表达在生精细胞凋亡的调控中起重要作用.     

己烯雌酚摄入对大鼠生精细胞凋亡及Bax和Bcl-2蛋白表达的影响

目的研究青春期己烯雌酚(diethylstilbestrol,DES)摄入对SD(Sprague-Dawley)大鼠性成熟后睾丸生精细胞凋亡的影响,并初步探讨其机制。方法30只35d龄雄性SD大鼠,随机分为DES 0.01、0.1、1.0、10.0μg/kg·d~(-1)4个实验组和1个对照组(编码为BDa、BDb、BDc、BDd和BC组,每组n=6)。于青春期[出生后第36天(postnatal day 36,PND 36)至49d(PND 49)],实验组每日皮下注射相应剂量的DES,对照组仅注射溶媒。于大鼠性成熟后(PND 64)处死各组大鼠切取双侧睾丸,采用TUNEL法检测大鼠睾丸生精细胞凋亡,用免疫组化方法检测凋亡相关蛋白Bcl-2和Bax在生精细胞中的表达。结果与对照组相比,BDa组大鼠性成熟后生精细胞凋亡无明显变化,BDb、BDc和BDd 3组生精细胞凋亡增加,且随DES摄入剂量增加而有增加趋势。BC、BDa组生精细胞Bax相对弱表达而Bcl-2强表达,伴随DES摄入剂量增加,Bax表达逐渐增强而Bcl-2表达逐渐减弱,BDd组Bax强表达而Bcl-2弱表达。结论青春期较大剂量DES摄入可使大鼠性成熟后睾丸生精细胞凋亡增加,且随DES摄入剂量增加而有加强趋势。凋亡相关蛋白Bax和Bcl-2参与青春期DES摄入所致的生精细胞凋亡过程。     

Attractin蛋白在不同病理分型无精子症患者睾丸组织中的表达

目的探讨Attractin蛋白在不同生精功能状态的人睾丸组织中的表达情况。方法对31例无精子症患者进行睾丸组织病理检查诊断,根据病理形态的不同分为:唯支持细胞综合征型(n=4),生精功能低下型(n=12),生精阻滞型(n=5),生精功能基本正常型(n=10)。选择上述各型结构完整的睾丸组织,分别应用免疫组化法(SP)观察Attractin蛋白在不同生精功能状态的睾丸组织中的表达。结果各组睾丸组织内均存在Attractin蛋白的表达,其分布特点为:睾丸生精小管和间质细胞、管周肌样细胞、支持细胞上均有Attractin蛋白的表达,主要表达于胞膜和胞质,胞膜表达强于胞质。Leydig细胞、Sertoli细胞、精原细胞、精母细胞及精子细胞均为阳性表达,呈棕黄色着染。Attractin的表达与生精功能有关,正常组表达明显高于其它组,唯支组表达明显低于其他组。结论 Attractin蛋白与男性生殖密切相关,但其具体作用环节尚有待进一步研究。     

青春期前己烯雌酚暴露对大鼠性成熟后生精细胞凋亡的影响及其机制初探

目的:研究青春期前己烯雌酚(d iethylstilbestrol,DES)暴露对SD大鼠性成熟后睾丸生精细胞凋亡的影响并初步探讨其机制。方法:30只21日龄雄性SD大鼠,随机分为DES 0.01、0.1、1.0、10.0μg/(kg.d)4个实验组和1个对照组(编码为ADa、ADb、AD c、ADd和AC组,每组6只)。于青春期前[出生后第22 d(postnatal day 22,PND22)至35 d(PND35)],实验组每日皮下注射相应剂量的DES,对照组仅注射溶媒。于大鼠性成熟后(PND 64)处死各组大鼠切取双侧睾丸,采用TUNEL法检测大鼠睾丸生精细胞凋亡,用免疫组化方法检测凋亡相关蛋白Bc l-2和Bax在生精细胞中的表达。结果:与对照组相比,ADa组大鼠性成熟后生精细胞凋亡无明显变化,ADb、AD c和ADd 3组生精细胞凋亡增加,且随DES暴露剂量增加而有增加趋势。AC、ADa组生精细胞Bax相对弱表达而Bc l-2强表达,伴随DES暴露剂量增加,Bax表达逐渐增强而Bc l-2表达逐渐减弱,ADd组Bax强表达而Bc l-2弱表达。结论:青春期前较大剂量DES暴露可使大鼠性成熟后睾丸生精细胞凋亡增加,且随DES暴露剂量增加而有加强趋势。凋亡相关蛋白Bax和Bc l-2参与青春期前DES暴露所致的生精细胞凋亡过程。     

睾丸特异表达基因-1在小鼠隐睾模型中的表达及其意义

目的 探讨睾丸特异表达基因-1(TSEG-1)在小鼠隐睾模型中的定位、定量表达变化及其意义.方法 将46只雄性昆明新生小鼠随机分为对照组(n=10)、丙二醇(溶剂)注射组(n=15)、17β-雌二醇注射组(n=21),应用苏术素-伊红(HE)染色观察睾丸组织形态学改变,原位杂交、逆转录-聚合酶链反应(RT-PCR)和实时定量PCR检测TSEG-1 mRNA的定位和定量变化.结果 17β-雌二醇注射组发生隐睾,而对照组和丙二醇注射组睾丸位置正常.与对照组比较,17β-雌二醇组睾丸组织80%曲精小管管腔消失,Ⅰ～Ⅳ级生精细胞数目减少,60%精母细胞或精子细胞核皱缩,90%精子发生障碍.在对照组睾丸组织中,TSEG-1 mRNA表达水平是模型组25倍,主要定位于精母细胞和早期精子细胞,而隐睾组TSEG-1 mRNA表达水平显著下调.结论 17β-雌二醇诱导小鼠隐睾模型是制作隐睾模型的有效方法 ,新基因TSEG-1可能参与雌激素诱导隐睾模型的发生过程.     

抑制素B βB亚单位在不同病理分型的无精子症患者睾丸组织中的表达

目的:探讨抑制素B(INH B)βB亚单位在不同生精功能状态的人睾丸组织中的表达情况。方法:对83例无精子症患者进行睾丸组织病理检查诊断,根据病理形态的不同分为:唯支持细胞综合征型(n=21);生精功能低下型(n=20);生精阻滞型(n=24);生精功能基本正常型(n=18)。选择上述各型结构完整的睾丸组织,分别应用免疫组化法(SP)对血清INH B βB亚单位在不同生精功能状态的睾丸组织,进行定位研究。结果:各型睾丸组织内均存在血清INH B βB的表达,其分布特点为:间质细胞(Leydig cell)和早期生精细胞多为强阳性表达,呈深棕黄色;支持细胞(Sertoli cell)多为阳性表达;而晚期精子细胞和成熟精子未见表达;生精小管管周类肌细胞呈弱阳性表达。结论:INH B可能是睾丸Sertoli细胞和早期生精细胞的一个联合产物。     

抗氧化剂与钙离子拮抗剂联合应用预防大鼠睾丸纤维化实验研究

目的 :研究抗氧化剂与钙离子拮抗剂联合应用对大鼠睾丸纤维化的防治效果 ,以探索防治睾丸纤维化发生的理想药物。　方法 :将正常雄性Wistar大鼠 80只分为正常对照组 (n =10 ) ,高 (n =2 0 )、中 (n =2 0 )、低 (n =17)预防睾丸纤维化组和睾丸纤维化模型组 (n =13) ,采用王涛等建立的大鼠睾丸纤维化模型的方法略加改进。从第 1次免疫的次日起 ,高剂量组给予维生素E、C合剂 90mg/ (kg·d)、维拉帕米 5 0mg/ (kg·d)灌胃 ,中剂量组给予维生素E、C合剂 90mg/ (kg·d)、维拉帕米 2 5mg/ (kg·d)灌胃 ,低剂量组给予维生素E、C合剂 90mg/ (kg·d)、维拉帕米 12 .5mg/ (kg·d)灌胃 ,共 15 0d。纤维化模型组未予干预措施。正常对照组未加任何处理。检测精子计数、精子畸形率、睾丸长度、精曲小管直径 ,光镜和透射电镜观察睾丸间质及精曲小管生精细胞的变化。　结果 :高、中剂量组对于预防大鼠睾丸纤维化效果显著 ,睾丸精曲小管直径、基膜厚度与正常对照组相比差异无显著性。低剂量组精曲小管界膜略增厚 ,生精细胞损伤较重 ,但病变仍轻于模型组。模型组睾丸间质增生显著 ,间质中、精曲小管的管周及睾丸被膜下可见肥大细胞增多 ,精曲小管的界膜显著增厚 ,生精上皮空泡变。　结论 :抗氧化剂与钙离子拮抗剂联合应用 ,     

阿霉素肾病大鼠肾皮质环加氧酶2的表达及调节

目的 探讨阿霉素肾病大鼠肾皮质环加氧酶2(C0X2)的表达及特异性C0X2抑制剂rofecoxib对其的影响。方法 将大鼠随机分为正常对照组(n＝6)、阿霉素肾病(ADR)组(n＝8)、rofecoxib组(n＝7)、吲哚美辛组(n＝8)及氯沙坦组(n＝7)。8周后检测大鼠尿蛋白与尿TXB2的排泄量，检测肾皮质血管紧张素Ⅱ(AngⅡ)浓度；应用免疫组织化学、RT—PCR及western印迹的方法检测C0X2及C0Xl mRNA及蛋白质的表达。结果 与正常对照组相比，ADR肾病大鼠尿蛋白及肾皮质COX2的表达与尿TXB2排泄明显增多，C0X1表达无明显变化，AngⅡ浓度明显增高；rofecoxib组肾皮质C0X2表达下调，尿TXB2排泄明显减少，C0X1表达无明显变化，AngⅡ浓度降低；吲哚美辛组C0X2及C0X1表达均下调，尿TXB2排泄明显减少；氯沙坦对C0X2及C0X1无明显影响。结论 ADR肾病大鼠肾皮质C0X2的表达与尿TXB2排泄明显增多，C0X1表达无明显变化。特异性C0X2抑制剂(rofecoxib)使C0X2的表达下调，部分抑制肾素—血管紧张素系统的兴奋。     

Aldose reductase expression is induced by hyperglycemia in diabetic nephropathy.

BACKGROUND: Despite good metabolic control, many patients with type 1 diabetes still develop nephropathy, implicating a role for genetic factors. Recent studies examining the regulatory region of the aldose reductase (ALR2) gene, the rate-limiting enzyme of the polyol pathway, support its role as a candidate gene for nephropathy. Here we report the quantitation of ALR2, together with sorbitol dehydrogenase mRNA in the peripheral blood mononuclear cells (PBMCs) of type 1 diabetic patients with (N = 29) and without nephropathy (N = 11) following stimulation with high levels of D-glucose. METHODS: PBMCs from patients and normal controls were cultured for five days with phytohemagglutinin in either normoglycemia (11 mmol/L D-glucose) or supplemented with 10 mmol/L D-glucose (moderate hyperglyemia) or 20 mmol/L D-glucose (hyperglycemia). The RNA was extracted and analyzed by ribonuclease protection assay. RESULTS: ALR2 mRNA levels were significantly elevated with increasing D-glucose concentration (normal to hyperglycemic) in those patients with nephropathy (P < 0.0001). In marked contrast, in those without nephropathy and in the normal healthy controls, there was no change in mRNA expression. Furthermore, those patients with nephropathy and the Z-2/X susceptibility genotype had the greatest increase in ALR2 mRNA compared with those with low-risk genotypes (P < 0.007). CONCLUSION: These results show that patients with nephropathy exhibit marked disturbances in the expression of the enzyme components of the polyol pathway. Ultimately this leads to tissue damage and ischemia.     

氟他胺诱导大鼠隐睾生殖母细胞残留模型

目的:观察胚胎期氟他胺(Flu)对SD大鼠睾丸生殖细胞发育的影响,建立研究隐睾生殖母细胞(Go)发育缺陷机制及治疗的模型。方法:36只SD孕鼠随机分为Flu组(n=20)、玉米油组(n=8)和空白对照组(n=8)3组,Flu组和玉米油组于妊娠12～21 d(GD12-21)分别给予Flu 25 mg/(kg.d)和1 ml/(kg.d)皮下注射,在出生后1 d(PD1)、PD10、PD20、PD80收集标本,观察睾丸形态学、组织学的差异,免疫组化及RT-PCR检测神经母细胞粘附分子(NCAM)表达。结果:Flu诱导隐睾发生率为43.9%(29/66)。PD20、PD80隐睾睾丸质量、脏器系数较对照组有显著性差异;PD10 Flu诱导睾丸组织中可见Go迁移障碍,滞留于管腔中央,Flu诱导PD20、PD80隐睾组织中仍可见迁移障碍的Go位于管腔中央;免疫组化检测结果显示迁移障碍的Go胞膜阳性表达NCAM,且PD10、PD20睾丸RT-PCR检测结果显示Flu诱导隐睾组织中NCAM的mRNA表达高于对照组。结论:Flu成功诱导大鼠隐睾Go残留模型,可以用于研究隐睾生殖母细胞发育缺陷的机制及治疗。     

肝再生增强因子对大鼠腹腔移植的肝细胞的影响

目的 探讨肝再生增强因子(ALR)对急性肝功能衰竭大鼠腹腔移植的肝细胞的影响.方法 采用D-氨基半乳糖诱导SD大鼠急性肝功能衰竭(AHF),然后将其随机分为空白对照组(仅接受生理盐水腹腔注射)、移植对照组(腹腔移植SD大鼠的肝细胞2×107个)、环孢素A组(CsA组,接受肝细胞移植后腹腔注射CsA 6 d)、ALR组(接受肝细胞移植后腹腔注射ALR 6 d)和ALR对照组(仅腹腔注射ALR 6 d).实验期为14 d,观察受者的存活情况及移植肝细胞存活情况,检测腹腔内细胞CD4、CD8及CD68的表达情况,测定血清及腹腔冲洗液中自细胞介素1β(IL-1β)和肿瘤坏死因子a(TNF-a)的水平.结果 空白对照组、移植对照组、CsA组、ALR组及ALR对照组的受者2周存活率分别为0、46.7%、20%、66.7%和14.3%,ALR组显著高于空白对照组(P=0.001).移植后1～2 d,ALR组血清TNF-a和IL-1β明显低于空白对照组和移植对照组(P<0.01);移植对照组腹腔冲洗液中TNF-a和IL-1β水平明显高于其它各组(P<0.05,P<0.01).至移植后14 d,各组存活大鼠的血清TNF-a和IL-1β水平接近正常水平.移植后1～2 d,ALR组移植物内CD68表达水平为(0.5±0.3)%,明显低于移植对照组和CsA组(P<0.01);ALR组腹腔内细胞CD68、CD4及CD8表达水平分别为(1.3±1.2)%、(0.1±0.3)%和(0.2±0.1)%,均明显低于移植对照组(P<0.01,P<0.01,P<0.05).移植后1～3 d,接受肝细胞移植的大鼠腹腔内可见聚集成团的肝细胞结节,ALR组存活的肝细胞数明显多于移植对照组和CsA组,且炎症细胞浸润较少,至移植后14 d,仅ALR组可见少量形态正常的肝细胞.结论 腹腔内肝细胞移植联合ALR腹腔注射能提高AHF大鼠的存活率;ALR能短期改善移植肝细胞的存活状况.     

Artificial intra-abdominal cryptorchidism in young adult rats leads to irreversible azoospermia

To study reversibility of artificial intra-abdominal cryptorchidism, in four groups of 5 rats at 3 months of age vasocystostomies (a microsurgical operation anastomosing both sperm ducts into the urine bladder) were carried out. This procedure enables sperm output measurements, which was performed by putting the animals for 24 h in metabolic cages. Four weeks later 15 of the remaining animals were operated again to induce artificial cryptorchidism. In a fourth group, 3 animals were sham-operated only, leaving the testes in place. Two weeks later in the animals of group I cryptorchidism was reversed by an orchiopexy operation; in group II orchiopexy was carried out after 4 weeks, in group III after 8 weeks. In group IV the animals were sham-operated again. Evaluation of sperm output took place for 3 months after orchiopexy. In the 1st week after vasocystostomy the animals showed a large variation in sperm output, but 2 weeks later, all animals had sperm output between 30-60 x 10(6) of spermatoza/24 h. Immediately after cryptorchidism sperm output decreased dramatically, and 2 weeks later all animals were azoospermic, except for sham-operated controls. After orchiopexy not one of the experimental animals showed any return of spermatozoa. We concluded that intra-abdominal cryptorchidism soon leads to irreversible damage to the testes resulting in azoospermia.     

同源盒基因-A10在人体睾丸组织的表达及其临床意义

目的比较同源盒基因-A10(HOXA10)在正常人和隐睾症患者睾丸组织的表达差异。方法收集正常人和隐睾症患者的睾丸组织,采用反转录-多聚酶链式反应(RT-PCR)和免疫组织化学的方法检测HOXA10的表达水平。结果HOXA10在正常人和隐睾症患者的睾丸组织均有表达,与正常组织比较,HOXA10在隐睾症患者睾丸组织的表达显著降低。结论HOXA10的表达减少与隐睾症的发生有密切关系。     

Anti‐inflammatory effect of platelet‐rich plasma on nucleus pulposus cells with response of TNF‐α and IL‐1

The purpose of this study was to investigate the anti‐inflammatory effect of platelet‐rich plasma (PRP) with collagen matrix on human nucleus pulposus (NP) cell in response to pro‐inflammatory cytokines such as tumor necrosis factor‐alpha (TNF‐α) and interleukin‐1 (IL‐1). NP cells from human disks were cultured in a monolayer and maintained in the collagen matrix prior to the addition of recombinant human IL‐1 and TNF‐α. After applying IL‐1 and TNF‐α, PRP prepared by using a commercially available platelet concentration system was added. The response was investigated using real‐time PCR for mRNA expression of type II collagen, aggrecan, matrix metalloproteinase‐3 (MMP‐3), and cyclooxygenase‐2 (COX‐2). The combination of IL‐1β and TNF‐α led to decrease of matrix synthesis gene expression such as collagen type II and aggrecan and increase of the degradation gene expression of COX‐2 and MMP‐3, compared to the control. Consecutive PRP exposure significantly recovered the down‐regulated gene expression of collagen type II and aggrecan and significantly reduced the increased MMP‐3 and COX‐2 gene expression, compared to that of control groups with pro‐inflammatory cytokines. The administration of PRP with collagen matrix markedly suppressed cytokine‐induced pro‐inflammatory degrading enzymes and mediators in the NP cell. It also rescued gene expression concerning matrix synthesis, thereby stabilizing NP cell differentiation. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:551–556, 2014.     

Gene damages of mitochondrial DNA encoding cytochrome oxidase of intestinal epithelial cells in hemorrhagic shock rats

Objective: To investigate the detrimental effects of hemorrhagic shock on the structure and function of mitochondria DNA (mtDNA) encoding cytochrome oxidase genes in intestinal epithelial cells. Methods: Wistar rats were used and divided into two groups: hemorrhagic shock group and control group. Hemorrhagic shock model of rats was utilized in this experiment. The mtDNA was extracted from the intestinal epithelial cells and amplified by polymerase chain reaction (PCR) with different primers of cytochrome oxidase (COX I, COX II and COX III). The products of PCR were directly sequenced. Results: Hemorrhagic shock could result in the point mutagenesis in mitochondrial genome encoding cytochrome oxidase (COX I and COX II). There were 4, 4, 22, 16, 35 point mutations in COX I from 5545 to 6838 bp in 5 shocked rats. There were five point mutations in COX II from 7191 to 7542 bp at the site of t7191c, t7212c, a7386g, a7483g, c7542g in 1 shocked rat. There was no mutation found in COX III. Conclusions: Hemorrhagic shock could significantly induce the damage of the gene of cytochrome oxidase encoded by mtDNA.     

Cyclooxygenase-2 induces genomic instability, BCL2 expression, doxorubicin resistance, and altered cancer-initiating cell phenotype in MCF7 breast cancer cells

INTRODUCTION: Cyclooxygenase (COX2) expression in primary breast cancer correlates with a worse prognosis. We reported previously that COX2 expression in MCF10A breast epithelial cells of basal subtype induces genomic instability. To understand the role of COX2 in estrogen receptor-positive (non-basal) breast cancer, we transfected the MCF7 cell line with COX2 and analyzed its chromosomal profile, BCL2 protein expression, and resistance to doxorubicin. We also analyzed cell cultures grown as mammospheres to determine whether COX2 expression affects the cancer-initiating ("stem") cell phenotype in MCF7 cells. METHODS: MCF7 Tet On cells (obtained from Clontech) were stably transfected with pTRE2pur-COX2 or pTRE2pur-COX2-GFP to produce COX2 or COX2-GFP protein, respectively. BCL2 protein was detected by Western blotting. Sensitivity of cells to drug treatment was analyzed by MTT assay. Groups were compared using Chi-Square test. We analyzed the genomic instability phenotype by chromosome analysis of control and COX2 transfected metaphase-arrested MCF7 cells after Giemsa staining. We assessed the tumorigenic potential of cells grown as mammospheres with a clonogenic assay. RESULTS: Cytogenetic analysis of early passage COX2 transfected MCF7 cells demonstrated significant genomic instability as compared to parental MCF7 cells. COX2 overexpression was associated with a significant increase in chromosomal aberrations (chromatid breaks, chromosome fusions, C anaphase). COX2 transfected MCF7 cells produced a significantly higher level of the anti-apoptotic protein BCL2 than the parental cells. In a functional assay, we found that COX2 expression correlated with increased resistance to doxorubicin. In a complimentary approach to determine tumorigenic potential of cells, we found that COX2 increased the ability of MCF7 cells to grow as mammospheres in culture, which correlated with an increase in clonogenic efficiency. CONCLUSIONS: We found that COX2 expression in MCF7 breast cancer cells induced genomic instability, BCL2 expression, and doxorubicin resistance, thus making them significantly more tumorigenic. This data suggests that COX-2 may be an important target for breast cancer treatment.