IRE1信号通路在热诱导睾丸生殖细胞凋亡中的作用

目的探讨内质网应激IRE1信号通路在急性热应激诱导睾丸生殖细胞凋亡中的作用。方法 24只成年ICR雄性小鼠,随机分为4组。将热处理组小鼠身体的下1/3部分(包括阴囊、后腿和尾巴)浸于43℃恒温水浴中15 min,于热处理后0.5、2和6 h取睾丸组织。将对照组小鼠下腹部浸入22℃水浴15 min,6 h后取睾丸组。采用TUNEL法检测睾丸组织生殖细胞凋亡;用半定量RT-PCR技术检测u XBP-1/s XBP-1 mRNA表达;用Western blot检测睾丸总蛋白p-JNK表达。结果单次热应激能够明显诱导小鼠睾丸生殖细胞凋亡。与对照组相比,热处理能够明显降低睾丸组织u XBP-1/s XBP-1 mRNA的比值,以热处理后0.5和2 h最为显著,而随着时间的延长,又逐渐恢复正常。热应激明显诱导睾丸JNK(另一个IRE1的下游分子)磷酸化水平。结论单次热处理能激活睾丸组织内质网应激IRE1通路,在早期可能激活IRE1-XBP-1通路保护睾丸组织对抗热应激,而后期可能通过激活IRE1-JNK通路诱导睾丸生殖细胞凋亡。     

杨桃根DMDD对高糖诱导的肾小管上皮细胞HK-2内质网应激IRE1α通路及炎症反应的抑制作用北大核心CSCD

目的研究杨桃根活性成分2-十二烷基-6-甲氧基-2,5-二烯-1,4-环己二酮(DMDD)对高糖诱导肾小管上皮细胞HK-2内质网应激及炎症反应的抑制作用。方法体外培养HK-2细胞,并分为正常组、高糖组、内质网应激抑制剂4-PBA组(5 mmoL·L^(-1))和DMDD高、中、低浓度组(8、4、2μmol·L^(-1))。各组细胞培养结束后,采用CCK-8法检测细胞存活率;ELISA检测细胞上清液中TNF-α、IL-6的水平;AO/EB染色法检测细胞凋亡;Western blot法检测细胞中凋亡相关蛋白Bcl-2、Bax的表达水平、内质网应激标志蛋白GRP78、CHOP的表达水平以及IRE1α通路相关蛋白(IRE1α、JNK)的磷酸化水平。结果与高糖组比较,DMDD各浓度组细胞存活率明显升高;TNF-α、IL-6水平,Bax/Bcl-2、GRP78、CHOP蛋白表达水平和IRE1α、JNK蛋白磷酸化水平均明显降低,细胞中橙红色荧光明显减少。结论DMDD可能部分通过抑制内质网应激及IRE1α通路相关蛋白的表达,减少炎症反应,达到HK-2细胞的保护作用。     

酞菁锌光动力治疗诱导大肠癌Lovo细胞产生活性氧 #br#

目的 探究 P38MAPK 介导四-a-（对羧基苯氧基）酞菁锌（TαPcZn）光动力治疗（PDT）诱导的人结肠癌 Lovo 细胞线粒体损伤的机制。方法 将细胞分别设立对照组、siRNA-阴性对照组、siRNA-P38MAPK 转染组、 TαPcZn-PDT组和 TαPcZn-PDT/siRNA-P38MAPK组,各组细胞处理后经红光照射 10 min,然后孵育 3 h。孵育结束后 RT-PCR 和 Western blot 检测 P38MAPK 沉默效果。采用 DCFH-DA 探针检测各组细胞活性氧（ROS）水平、JC-I/7- AAD 双标染色法检测线粒体膜电位（ΔΨm）的变化,AnnexinV-FLOUS/7-AAD 双标染色法检测细胞凋亡率。结果 siRNA干扰后 P38MAPK的 mRNA和蛋白表达水平明显下降。TαPcZn-PDT明显诱导 Lovo细胞 ROS增加,引起线粒 体 ΔΨm去极化,细胞凋亡率升高。siRNA沉默P38MAPK后,TαPcZn-PDT诱导 Lovo细胞产生的 ROS减少,发生 ΔΨm 去极化的细胞减少,凋亡率下降。结论 在 TαPcZn-PDT作用下,沉默 P38MAPK 基因可明显抑制 ROS的产生及释 放,减弱线粒体 ΔΨm的去极化,从而降低光激发 TαPcZn所诱导的细胞凋亡。     

脂多糖通过LDLr诱导巨噬细胞泡沫化:炎症应激下巨噬细胞泡沫化的另一条通路

目的研究炎症介质-脂多糖(LPS)诱导的炎症应激是否通过扰乱固醇调节元件结合蛋白裂解激活蛋白-固醇调节元件结合蛋白2(SCAP-SREBP2)复合物介导的低密度脂蛋白受体(LDLr)负反馈调控,增加THP-1巨噬细胞对非修饰低密度脂蛋白胆固醇(LDL)摄取,导致泡沫细胞形成。方法诱导分化成功的THP-1巨噬细胞在无血清培养基中培养4 h后,分为对照组(继续无血清培养),高脂组(加入LDL负荷,终浓度为25 mg·L-1),高脂加炎症刺激组(加入LDL负荷,终浓度为25 mg·L-1,同时加入炎症介质LPS,终浓度200μg·L-1),单纯炎症刺激组(加入炎症介质LPS,终浓度200μg·L-1),以上各组细胞培养24 h后收获。ELISA法检测细胞培养基中TNF-α浓度,酶化学法检测细胞内胆固醇浓度,琼脂糖电泳检测LDL氧化程度,Real time PCR法检测LDLr、SREBP2和SCAP mRNA表达水平,Western blot法检测LDLr、SREBP2和SCAP蛋白表达,激光共聚焦检测SCAP在内质网与高尔基体间的转位情况。结果细胞内胆固醇测定发现,炎症介质LPS通过增加THP-1巨噬细胞对非修饰LDL摄取,导致巨噬细胞转变为泡沫细胞。在无炎症介质LPS时,25 mg·L-1LDL减少LDLr mRNA和蛋白表达(P<0.05)。然而,LPS增加LDLr mRNA和蛋白表达,逆转25 mg·L-1LDL对LDLr的抑制效应,不恰当的增加了巨噬细胞对LDL摄取(P<0.05),LPS刺激也导致了SCAP和SREBP2的mRNA和蛋白过表达(P<0.05),同时促进了SCAP从内质网转移到高尔基体。这些结果提示LPS干扰了胆固醇介导的LDLr负反馈调控,使非修饰LDL在巨噬细胞内堆积,导致泡沫细胞形成。结论本研究提示,在LPS诱导的炎症应激状态条件下,天然LDL可以通过LDLr被巨噬细胞大量摄取入细胞内,导致泡沫细胞形成,这可能是巨噬细胞泡沫化的另一条通路。     

载脂蛋白嵌合模拟肽对低密度脂蛋白诱导的巨噬细胞凋亡的影响

目的观察模拟肽Ac-hE-18A-NH2对氧化低密度脂蛋白(oxLDL)诱导的RAW264.7巨噬细胞凋亡的影响。方法50 mg.L-1oxLDL处理RAW 264.7细胞48 h后加入不同浓度的Ac-hE-18A-NH2(1、10、50、100 mg.L-1)和β-环糊精(β-CD)或布雷菲得菌素(BFA)共同孵育24 h。通过流式细胞仪检测细胞凋亡,试剂盒检测caspase-3活性及细胞内胆固醇含量,Western blot检测细胞bcl-2蛋白的表达,液体闪烁计数器检测细胞内胆固醇流出。结果 oxLDL诱导的RAW 264.7巨噬细胞的凋亡率随着oxLDL浓度的增加和处理时间的延长而明显提高。Ac-hE-18A-NH2(1、10、50、100mg.L-1)干预后细胞凋亡率以浓度依赖的方式减少。Ac-hE-18A-NH2呈浓度依赖性的促进细胞内胆固醇流出和降低细胞内的胆固醇含量,降低caspase-3的活性,上调bcl-2的蛋白表达。β-CD与Ac-hE-18A-NH2共同作用后胆固醇流出明显增加,细胞凋亡率相应减少。而BFA作用相反。结论Ac-hE-18A-NH2明显抑制oxLDL诱导的巨噬细胞凋亡,其作用可能与促进细胞胆固醇流出、减少细胞内胆固醇蓄积有关。     

柴胡桂枝汤对SE大鼠IRE1、 CHOP蛋白表达的影响

目的：观察柴胡桂枝汤对癫痫持续状态（statusepil epticus,SE）大鼠内质网应激IRE1信号转导通路前存活分子IRE1mRNA与前凋亡分子CHOP蛋白在大鼠海马区表达的变化及该区域神经元细胞凋亡情况。方法：采用氯化锂-匹罗卡品制作SE模型,将90只SD大鼠随机分为对照组、SE组、药物组3组,每组按照SE后2h、4h、8h、24h、72h五个时间点分为5个亚组。应用原位细胞凋亡检测法（TUNEL法）观察海马区神经元细胞凋亡数、用RT-PCR检测SE后海马IRE1mRNA的表达,用免疫组织化学法检测CHOP蛋白表达。结果：①SE组8～72h时间点TUNEL阳性细胞数多于对照组（P〈0.01）,其阳性细胞数随惊厥持续时间延长而增加。药物组8～72h时间点TUNEL阳性细胞数较SE组明显减少（P〈0.05）。②对照组IRE1mRNA有少量表达;SE组IRE1mRNA的表达于SE后4h表达量为最高,随后逐渐下调;其4h,8h,24h时间点较对照组有显著差异（P〈0.01）。药物组4h,6h,24h时间点海马区IRE1mRNA的表达明显高于SE组,差异有显著性（P〈0.05）。③对照组未见CHOP阳性细胞,SE组于2h后在海马区可见CHOP阳性细胞,随时间的延长阳性细胞数逐渐增多,于24h达到高峰,之后逐渐下降;SE组CHOP阳性细胞数与对照组比较,两者有显著差异（P〈0.01）。药物组各个时间点CHOP数量表达明显少于SE组,两者有显著差异（P〈0.01）。结论：柴胡桂枝汤可能通过减少SE对内质网的刺激,上调前存活分子IRE1的表达,下调前凋亡分子CHOP的表达,减轻异常放电对脑组织的病理损害,发挥对神经元的保护作用。     

TREM-1siRNA对内毒素刺激巨噬细胞杉RAW264．7分泌炎性因子影响

目的探讨靶向小鼠髓样细胞触发受体1（triggering receptor expressed on myeloid cells-1,TREM-1）的小分子干扰RNA（small inter-feting RNA,siRNA）在体外对内毒素刺激小鼠巨噬细胞株RAW264．7分泌肿瘤坏死因子α（tumor necrosis factor-α,TNF-α）、白纽胞介素1p（interleukin1B,IL-1β）的抑制作用。方法合成1条靶向小鼠TREM-1分子的siRNA序列,以增强型绿色荧光蛋白（EGFP）作为报告因子,荧光显微镜观察EGFP的荧光强度,验证siRNA序列的干扰率。以pLKO1-1为载体构建针对TREM-1的pLKO1．1-TREM1-shRNA干扰质粒。将小鼠巨噬细胞株RAW264．7分为4组：空白组;内毒素组（LPS组）;空质粒组（pLKO1．1组）：采用脂质体法将pLKO1．1转染细胞;干扰组（siRNA组）：将pLKO1．1-TREM1-shRNA转染细胞;转染72h后用内毒素刺激24h,并以实时定量PCR分别检测TREM．1、TNF-α与IL-1β的表达;以ELISA分别检测上清液中TNF-α、IL-1β含量。结果与LPS组比较,siRNA组中TREM．1、TNF—α、IL-1β的mRNA显著下降（P〈0．01）,上清液中TNF-α、IL-1β含量明显降低（P〈0．01）。结论小分子干扰RNA可能通过抑制TREM-1基因的表达而减少内毒素诱导小鼠巨噬细胞264．7中TNF-α、IL-1β的分泌。     

胰岛素对高糖诱导HepG2细胞ACAT2表达的影响

目的探讨胰岛素对高糖诱导人肝癌组织(HepG2)细胞中酰基辅酶A:胆固醇酰基转移酶2(ACAT2)表达的影响。方法将培养好的HepG2细胞以0.7×106L-1密度接种于6孔培养板内过夜培养,加入无血清培养基继续培养24 h后分别用正常培养基(对照组)、含终浓度为25 mmol/L甘露醇溶液(甘露醇组)和25 mmol/L葡萄糖溶液(高糖组)培养基分别与细胞孵育12 h;胰岛素组用含总浓度25 mmol/L葡萄糖培养基与细胞孵育4 h后,加入终浓度为30 mU/L胰岛素再孵育8 h。采用反转录-聚合酶链反应(RT-PCR)和蛋白免疫印迹(Western blot)法检测ACAT2的表达水平。结果高糖组HepG2细胞ACAT2表达明显高于对照组(P<0.01),胰岛素组ACAT2表达显著低于高糖组(P<0.01)。结论胰岛素可下调高糖诱导的ACAT2的表达。     

前胡甲素通过PPARα抑制LPS诱导的内皮细胞的炎症反应

目的探讨前胡甲素(Pd-Ia)对脂多糖(lipopolysaccha-ride,LPS)诱导的内皮细胞中细胞因子表达的影响及其作用机制。方法体外培养人脐静脉内皮细胞(HUVECs),用1mg·L-1LPS和不同浓度的Pd-Ia(10,20,40μmol·L-1)孵育24 h,采用荧光实时定量PCR检测TNF-α、IL-1β、PPARs(过氧化物酶体增殖激活受体)的表达。进一步在HUVECs中采用siRNA干扰PPARα后观察Pd-Ia的抗炎效应的变化。结果①Pd-Ia可以抑制LPS诱导的内皮细胞中TNF-α、IL-1β的表达。②Pd-Ia选择性上调LPS诱导的内皮细胞中PPAR-α的表达,而对PPAR-β、PPAR-γ的表达没有影响。③采用了siRNA特异性沉默PPARα后,Pd-Ia对TNF-α、IL-1β的下调作用被一定程度的逆转。结论 Pd-Ia对LPS诱导的内皮炎症反应有抑制作用,其机制与激活PPARα有关。     

炎症应激通过激活mTOR通路诱导THP-1巨噬细胞泡沫化的实验研究

目的研究脂多糖(LPS)诱导的炎症应激是否通过激活m TOR通路,增加SCAP/SREBP2表达,干扰SCAP/SREBP2负反馈调控,增加THP-1巨噬细胞对非修饰低密度脂蛋白胆固醇(LDL)摄取,导致泡沫细胞形成。方法诱导分化成功的THP-1源性巨噬细胞在无血清培养基中培养4 h后,分为对照组(5 mg·L~(-1)LDL)、炎症刺激组(5 mg·L~(-1)LDL+200μg·L~(-1)LPS)、炎症+雷帕霉素组(5 mg·L~(-1)LDL+200μg·L~(-1)LPS+10μg·L~(-1)Rapamycin)。以上各组细胞培养24 h后收获。油红O染色法检测各组细胞内脂质沉积情况,Real-time PCR法检测LDLr、SREBP2、SCAP、S6K1和m TOR mRNA水平,Western blot法检测LDLr、S6K1、mTOR蛋白表达,激光共聚焦法检测SCAP在内质网与高尔基体间的转位情况。结果油红O染色发现,炎症应激增加THP-1巨噬细胞内脂质沉积,雷帕霉素抑制炎症应激诱导的脂质聚积。Real-time PCR检测显示,炎症应激上调THP-1巨噬细胞LDLr、SREBP2、SCAP、S6K1和mTOR mRNA水平(P<0.05),雷帕霉素减少炎症应激诱导的LDLr、SREBP2、SCAP、S6K1和mTOR mRNA水平升高(P<0.05)。Western blot检测发现,炎症应激上调LDLr、S6K1和m TOR蛋白表达(P<0.05),雷帕霉素减少炎症应激诱导的LDLr、S6K1和mTOR蛋白表达水平升高(P<0.05)。激光共聚焦检测发现,炎症应激增加SCAP/SREBP2从内质网转位到高尔基体,雷帕霉素则抑制炎症应激诱导的SCAP/SREBP2复合物从内质网转位到高尔基体。结论炎症应激通过激活mTOR通路,上调SCAP/SREBP2表达,致SCAP/SREBP2复合体转位至高尔基体异常增加,LDLr表达上调,致使胆固醇聚积于细胞内,泡沫细胞形成。雷帕霉素能够逆转炎症应激诱导mTOR通路激活,减少细胞内胆固醇沉积,提示炎症应激状态下,mTOR可能是泡沫细胞形成的关键通路。     

三七总皂苷对小鼠巨噬细胞源性泡沫细胞形成的影响

目的:观察三七总皂苷(PNS)对小鼠巨噬细胞源性泡沫细胞形成的影响,以探讨PNS抗动脉粥样硬化(AS)作用的机制。方法:采用小鼠腹腔巨噬细胞与40mg.L-1的氧化低密度脂蛋白(ox-LDL)孵育72h建立泡沫细胞模型,用PNS进行干预。油红O染色观察细胞内脂质堆积情况,酶法测定细胞内总胆固醇(TC)、游离胆固醇(FC)、胆固醇酯(CE)的含量及CE/TC比值。结果:模型组细胞中TC、FC、CE及CE/TC均显著高于对照组细胞(P<0.01);与模型组比较,PNS高、中剂量组细胞内TC、FC、CE及CE/TC均有显著性降低(P<0.01);且PNS各剂量组间有显著性差异。形态学上,PNS高、中剂量组细胞的油红O染色阳性细胞数显著减少。结论:PNS可能通过抑制泡沫细胞的形成发挥抗AS的作用。     

S-亚硝基-N-乙酰-DL-青霉安对巨噬细胞诱导型一氧化氮合酶的影响

目的 观察S-亚硝基-N-乙酰-DL-青霉胺（SNAP）对RAW 264.7诱导型一氧化氮合酶（iNOS）表达的影响,探讨NO在动脉粥样硬化（炎症）过程中的作用.方法 以RAW 264.7巨噬细胞为研究对象,分为空白对照组、SNAP组,采用不同浓度（30、100、300、400、500μmol/L）的SNAP对巨噬细胞进行干预24 h,应用RT-PCR法检测RAW 264.7巨噬细胞iNOS mRNA的表达,采用Western blotting技术检测iNOS蛋白的表达.结果 与空白对照组比较,不同浓度SNAP（30、100、300、400、500 μmol/L）组iNOS mRNA的表达比空白对照组均明显降低（P＜0.05）,不同浓度SNAP（30、100、300 μmol/L）组iNOS蛋白表达明显低于空白对照组（P＜0.05）.结论 NO可以抑制巨噬细胞自身iNOS mRNA基因转录,降低iNOS的合成而发挥负反馈作用.     

Involvement of unfolded protein responses in neurodegeneration]

Various stresses cause the accumulation of unfolded proteins in the endoplasmic reticulum (ER). To manage the state, cells have the unfolded protein responses (UPR). If the UPR is unsuccessful, ER-mediated apoptosis occurs. To date, three types of UPR, i.e. the induction of chaperones, the translation block, and ER-associated degradation (ERAD) have been reported. To sense the accumulation of unfolded proteins, the ER has IRE1, PERK, and ATF6. The pathways mediated by IRE1 and ATF6 cause the induction of chaperones. The pathway mediated by PERK causes a translation block. The induction of caspase 12, the activation of the JNK pathway, and the induction of CHOP have been reported as apoptosis caused by ER stress. The stability of the cell is based on the balance between UPR and ER-mediated apoptosis. Recently several diseases have been reported to be related to ER stress. We reported that mutant presenilin 1 causes a vulnerability to ER stress because it attenuates the activation of IRE1, PERK, and ATF6. Recent reports have also shown that Parkinson disease and polyglutamine diseases are relevant to ER stress. Therefore it is suggested that the ER stress story is the common mechanism for neurodegerative disorders.     

Elevated temperature accelerates and amplifies the induction of nitric oxide synthesis in rat macrophages

Evidence has accrued that nitric oxide (NO) is an effector molecule in cell-mediated immunity, and it is generally agreed that fever is beneficial to host defence. Therefore, the role of elevated temperature in the induction of NO synthesis was examined in rat peritoneal macrophages activated by lipopolysaccharide (LPS). When macrophages were incubated in vitro at 40°C, the time between macrophage activation and the induction of NO synthesis, as assessed by nitrite accumulation in the medium, was shortened as compared with incubation at 37°C, and nitrite accumulation was markedly enhanced by 2.6- and 1.8-fold after 6 and 9 h of LPS activation, respectively. These results suggest that elevated temperature may contribute to enhance host defence by accelerating and amplifying the induction of NO synthesis in macrophages.     

GLUCOSE-REGULATED PROTEIN 78 PROMPTS SCAVENGER RECEPTOR A-MEDIATED SECRETION OF TUMOUR NECROSIS FACTOR-α BY RAW 264.7 CELLS

• 1 Activation of macrophages plays an important role in atherosclerosis. In order to investigate the effect of endoplasmic reticulum (ER) stress on cytokine release from macrophages, the RAW 264.7 mouse macrophage cell line was treated with 0.2 mmol/L 6‐aminonicotinamide (6‐AN) for 36 h and the secretion of tumour necrosis factor (TNF)‐α determined. In addition, Raw 264.7 cells were incubated in the presence of 10 µg/mL acetylated low‐density lipoprotein (acLDL) at 37°C for 8 h.
• 2 Secretion of TNF‐α from RAW 264.7 cells was stimulated by both loading of cells with acLDL and following 6‐AN treatment. In addition, the expression of glucose‐regulated protein (GRP) 78 was increased in 6‐AN‐treated cells (by 165%).
• 3 In separate experiments, PD98059, a specific inhibitor of the mitogen‐activated protein kinase kinase (MEK) pathway, blocked acLDL‐ and/or 6‐AN‐induced TNF‐α secretion, whereas LY294002, which blocks the AKT signalling pathway, had no effect. On the basis of these results, we speculate that acLDL/6‐AN‐induced secretion of TNF‐α from RAW 264.7 cells may be regulated by activation of the MEK signalling pathway.
• 4 The present study suggests that the accumulation of lipids in cells and/or ER stress could lead to macrophage apoptosis as a result of the increased production of TNF‐α, which integrates into atherosclerosis.

     

流式细胞术检测小鼠腹腔巨噬细胞吞噬功能

目的确立采用流式细胞仪检测小鼠腹腔巨噬细胞吞噬功能的实验条件,以提供一种快速、准确和敏感的方法评价保健食品对吞噬功能的影响。方法取昆明种小鼠巨噬细胞,与荧光素标记大肠杆菌于37℃避光孵育1.5h,与荧光微球于4℃,25℃及37℃避光孵育1.5h或于37℃避光孵育0.5,1.0,1.5和2h后,用流式细胞仪观察和分析腹腔巨噬细胞吞噬荧光微球或荧光素标记大肠杆菌的能力。吞噬百分率(PP)表示吞噬一个或多个荧光微球的巨噬细胞占巨噬细胞总数的百分比;吞噬指数(PI)表示平均每个巨噬细胞吞噬荧光微球的数量;或吞噬荧光素标记大肠杆菌实验中,在M1处每个巨噬细胞的平均荧光强度(FI)。为验证和确定实验条件的可靠性,取昆明种小鼠每日经口分别给予蛹虫草菌丝体或灵芝孢子油30d后,取腹水巨噬细胞,分别与荧光微球或荧光素标记E.colik-12于37℃,培养1.5h后用流式仪进行吞噬功能的检测。结果25℃及37℃孵育条件时,PP分别为(28.0±1.4)%和(44.0±3.3)%,显著高于4℃的结果;1.5h及2.0h孵育时间,PP分别为(34.9±4.0)%和(39.5±11.3)%,显著高于0.5h及1.0h的结果。25~37℃孵育1.5~2.0h是合适的孵育条件。37℃孵育未加重组小鼠IFN-γ(rmIFN-γ)刺激时,PP为33.8%,PI为1.80,经rmIFN-γ处理后,PP为73.6%,PI为2.64,吞噬功能明显增强。0.15,0.30及0.90g.kg-1蛹虫草菌丝体处理组PP和0.30及0.90g.kg-1蛹虫草菌丝体处理组PI均较阴性对照组显著提高。0.33和1.00g.kg-1灵芝孢子油处理组M1处的FI显著高于阴性对照组。结论流式细胞术检测小鼠腹腔巨噬细胞吞噬功能是一种灵敏、简便、准确而高通量的定量评价保健食品影响吞噬功能的方法。     

金银花抗氧化作用的分子学机理研究

目的探讨金银花抗氧化作用分子学机理。方法采用过氧化氢（H2O2）作用于人正常RBL肝细胞，制作氧化应激损伤的细胞模型。将培养的细胞分为四个实验组：正常对照组（C），H2O2损伤组（H2），金银花前保护组（Jb），金银花后保护组（Ja）。采用TUNEL和DNA Ladder法，检测各组细胞凋亡情况。应用免疫组化和Western blot观察各组细胞的HSP-70、NF-kB、Bcl-2、Bax及Caspase-3的表达及免疫反应活性。应用MTT实验检测RBL细胞的生存率。结果Jb组的细胞凋亡率明显低于H2和Ja组，Bcl-2表达增高，HSP-70、NF-kB、Bax和Caspase-3的表达降低。结论金银花对RBL细胞氧化应激损伤具有一定保护作用．且前保护作用效果好于后保护作用，其保护作用机理可能是通过抑制HSP-70和NF-kB的表达，阻抑NF-kB信号传导途径并提高细胞内抗氧化防御酶系水平。     

ROLE OF LIPOPROTEIN-X IN FOAM CELL FORMATION AND RAT MESANGIAL CELL PROLIFERATION

1. In the present study, the effect of reconstituted lipoprotein-X (rLp-X) on lipid accumulation and foam cell formation in rat peritoneal macrophages was evaluated. Furthermore, the combined effect of rLp-X and macrophages on mesangial cell proliferation was examined. 2. Incubation of macrophages with rLp-X (177 and 387nmol unesterified cholesterol (FC)/mL) resulted in an increase of cellular cholestero. (162%) and cholesteryl esters (223 to 245%) relative to control. 3. Oil Red O staining of macrophages treated with rLp-X revealed the presence of foa. cells. 4. In conclusion, rLp-X had no effect on the proliferation of mesangial cells incubated in macrophage-conditione. medium.     

Induction of metallothionein by a macrophage factor and the partial characterization of the factor

The mechanism of metallothionein (MT) induction by lipopolysaccharide (LPS) was studied using an in vitro system. Rat peritoneal macrophages were incubated with or without LPS, after which the incubation medium was overlaid on human hepatic (Chang) cells. MT synthesis was induced in Chang cells treated with the macrophage medium incubated with LPS. No induction was observed when LPS was added directly to the Chang cell medium or when Chang cells were treated with the macrophage medium incubated without LPS. These results suggest that induction of MT by LPS is mediated by a factor released from macrophages. The factor is different from the known primary inducers of MT, such as heavy metals, glucocorticoid hormones, interleukin 1, and interferon. The factor is heat stable, nondialyzable, and stable at pH 2. Although its activity is lost by pepsin and trichloroacetic acid, it is resistant to trypsin.