阿托伐他汀对兔主动脉粥样斑块中γ-谷氨酰转移酶表达的影响

目的:研究他汀类药物对于兔主动脉粥样斑块内的γ-谷氨酰转移酶(GGT)表达的影响,同时探讨其表达活性的降低是否有助于斑块的进一步稳定,并证实斑块内的GGT与其他炎性因子的相关性。方法:选取15只新西兰雄性大耳白兔随机分成对照组、高脂组与他汀组。首先通过高脂饮食喂养高脂组和他汀组10周,建立兔主动脉粥样硬化模型。在模型成功建立后,以阿托伐他汀1.5mg·kg-1·d-1连续喂养他汀组6周进行干预。分别于0周、10周末、16周末对实验动物进行TC、TG、LDL、HDL及CRP检测。以ELISA法在第16周末进行GGT-1、VCAM-1和ICAM-1水平检测。实时定量PCR及Western blot方法检测主动脉GGT-1、VCAM-1和ICAM-1的表达。结果:经高脂喂养10周后,高脂组、他汀组兔LDL及TG水平较对照组明显增高,经阿托伐他汀干预治疗6周后他汀组LDL及TG水平较高脂组明显降低[LDL:(11.53±1.87)mmo/L︰(16.87±1.24)mmo/L;TG:(1.68±0.14)∶(2.74±1.88)mmo/L,均P0.05]。各组血CRP水平也有明显差异。相对于对照组,高脂组血浆GGT-1、VCAM-1和ICAM-1水平均显著增高。使用他汀干预后,他汀组兔血浆GGT-1、VCAM-1和ICAM-1水平,主动脉粥样斑块中GGT-1、VCAM-1和ICAM-1表达水平较高脂组均有显著下降(均P0.05)。结论:动脉粥样硬化模型兔外周循环中GGT水平明显升高。使用阿托伐他汀干预治疗后,GGT在其主动脉粥样斑块局部组织中的表达明显下降。阿托伐他汀可以有效抑制斑块中GGT的表达。这可能是他汀类药物抗粥样硬化作用的一个新机制。     

阿托伐他汀抗动脉粥样硬化的机制

目的通过观察阿托伐他汀对家兔主动脉粥样硬化消退作用和对血管细胞黏附分子-1(VCAM-1)和纤溶酶原激活物抑制物-1(PAI-1)的影响,探讨其抗动脉粥样硬化(AS)的可能机制.方法24只大耳白兔随机分为常规饲料组、胆固醇饲料组和阿托伐他汀组,饲养16周.观察实验前后血清胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白(LDL)、VCAM-1、PAI-1水平和体重的变化,处死动物后取主动脉进行病理学检查,采用免疫组化方法测定主动脉粥样硬化局部VCAM-1和PAI-1阳性表达百分数.结果实验前3组动物血清TC、TG、LDL、VCAM-1和PAI-1水平无显著差异(P＞0.05),16周后与胆固醇饲喂组比较,阿托伐他汀明显降低血清TC、LDL、VCAM-1和PAI-1水平,明显减少斑块/内膜面积比(0.161±0.027比0.281±0.037,P＜0.01);明显减少内膜厚度(38.11±6.02比67.47±7.13)μm;明显减少内膜/中膜比(0.391±0.213比0.878±0.370,P＜0.01).阿托伐他汀明显减少VCAM-1和PAI-1的阳性表达(P＜0.01).结论AS的发生伴有VCAM-1和PAI-1的过度表达,阿托伐他汀通过抑制它们的表达减轻AS病变可能是其抗AS机制之一.     

阿托伐他汀对小鼠实验性动脉粥样硬化病变形成的抑制作用

目的观察阿托伐他汀对载脂蛋白E基因缺陷(apoE-/-)小鼠实验性动脉粥样硬化(AS)病变形成及血管细胞黏附分子-1(VCAM-1)表达的影响,探讨阿托伐他汀抑制AS病变形成的可能机制。方法将apoE-/-小鼠随机分为3组:阿托伐他汀高、低剂量组、模型组(等量生理盐水),每组8只,给药第8周后全部处死。酶法检测血清脂质含量;比色法检测氧化指标一氧化氮(NO)、总抗氧化能力(TAC)及丙二醛(MDA);病理图像分析法测定主动脉AS斑块面积及其与管腔面积的比值;免疫组织化学染色方法测定主动脉壁VCAM-1表达。结果阿托伐他汀高、低剂量组与模型组apoE-/-小鼠比较显示:(1)阿托伐他汀(高、低剂量)可以显著降低总胆固醇、甘油三酯水平(P<0.01),升高高密度脂蛋白胆固醇水平(P<0.01);(2)明显增加血浆NO及TAC(P<0.01),减少MDA的生成(P<0.01);(3)阿托伐他汀可减少斑块面积与管腔面积比值(P<0.01);(4)阿托伐他汀可下调VCAM-1的表达(P<0.01)。结论阿托伐他汀可能通过调节apoE-/-小鼠血脂代谢、增强其抗氧化能力及下调主动脉壁VCAM-1表达,抑制apoE-/-小鼠AS病变形成的发展。     

通心络超微粉对高脂饮食兔胸主动脉NF-κB、胞间黏附分子1及血管细胞黏附分子1表达的影响

目的探讨通心络超微粉对高脂饮食兔胸主动脉NF-κB、胞间黏附分子1（ICAM-1）及血管细胞黏附分子1（VCAM-1）表达的影响。方法健康雄性新西兰白兔32只,随机分为空白对照组、模型组、阿托伐他汀组、通心络组四组。空白对照组,饲以普通饲料;模型组,饲以高脂饲料;阿托伐他汀组,饲以高脂饲料同时阿托伐他汀（3mg·kg^-1·d^-1）灌胃;通心络组,饲以高脂饲料同时通心络超微粉（0．31g·kg^-1·d^-1）灌胃,连续给药,于6周末免疫组织化学染色法检测主动脉壁中NF-κB核转位情况、ICAM-1及VCAM-1蛋白表达情况,RT—PCR法检测ICAM-1 mRNA及VCAM-1 mRNA表达。结果与空白对照组相比,模型组家兔主动脉壁中NF—KB核转位明显增加。ICAM-1、VCAM-1基因及蛋白表达明显增多（P〈O．01）。与模型组相比,通心络组与阿托伐他汀组家兔主动脉壁中NF-κB核转位明显减少、ICAM-1、VCAM-1基因及蛋白表达明显减少（P〈0．01或P〈0．05）,通心络组显著少于阿托伐他汀组（P〈0．01）。结论通心络超微粉通过抑制NF-κB核转位进而降低ICAM-1、VCAM-1基因及蛋白表达,减轻动脉粥样硬化病理改变。     

JAZF1基因过表达对ApoE~(-/-)小鼠脂代谢及动脉粥样硬化的影响

目的探讨JAZF1基因过表达对ApoE-/-小鼠脂代谢及动脉粥样硬化(AS)的影响。方法将48只雄性ApoE-/-小鼠随机分为:高脂+空载(GF组)及高脂+JAZF1质粒组(JAZF1组)、高脂+生理盐水组(HF组)。检测各组血脂、生化指标、组织脂质含量、粪便胆汁酸及主动脉内膜粥样硬化病变。采用[1-14 C]醋酸盐腹腔注射,免疫荧光观察JAZF1基因过表达对ApoE-/-小鼠肝脏TC合成代谢及斑块巨噬细胞聚集的影响。结果JAZF1组肝脏JAZF1表达以及HDL-C/TC高于HF、GF组(P均0.05),而FBG、FIns、TC、胰岛素抵抗指数(HOMA-IR)、动脉粥样硬化指数(AI)、血脂综合指数(LCI)和肝脏TC含量低于HF、GF组(P均0.05);与HF组和GF组比较,JAZF1组血管内膜脂质堆积减少,主动脉内斑块泡沫细胞聚集较少,斑块面积、斑块面积/管腔面积、主动脉粥样斑块内巨噬细胞CD68表达、肝脏14 C标记TC放射活性及肝和小肠14 C标记TC放射活性降低(P0.05或P0.01)。结论 JAZF1基因过表达可减少ApoE-/-小鼠肝脏TC含量,并抑制TC合成,改善脂代谢,抑制巨噬细胞在斑块内的聚集,减轻和延缓AS的形成。     

ApN/TNF-α信号途径在有氧运动防治ApoE-/-小鼠动脉粥样硬化过程中的抗炎症作用

目的观察有氧运动对ApoE-/-小鼠动脉粥样硬化(AS)的防治效果,探讨脂联素(ApN)/肿瘤坏死因子(TNF)-α信号途径的抗炎症作用。方法 8周龄雄性ApoE-/-小鼠随机分为对照组(C,10只)和运动组(E,10只)。14 w运动干预结束后取材观察主动脉管壁的病理变化,检测脂肪组织ApN mRNA表达和血清ApN水平及主动脉脂联素受体(AdipoR)1、TNF-α蛋白表达水平。结果 C组小鼠主动脉血管壁纤维板断裂,可见大量泡沫细胞浸润和纤维斑块,E组小鼠较C组主动脉病变有所延缓;E组小鼠ApN mRNA表达及血清水平显著高于C组(P0.05);E组小鼠主动脉AdipoR1蛋白表达显著高于C组(P0.05),主动脉TNF-α蛋白表达显著低于C组(P0.05)。结论有氧运动通过增强ApoE-/-小鼠ApN信号途径,抑制主动脉TNF-α蛋白表达,发挥防治AS的抗炎症作用。     

阿托伐他汀对动脉粥样硬化大鼠主动脉内膜增生的影响及与树突细胞分布的关系

目的 探讨动脉粥样硬化(AS)大鼠树突细胞(DCs)在外周血、动脉璧分布情况与主动脉内膜增生的关系以及阿托伐他汀的干预效应.方法 SD大鼠30只分组饲养12 w后,测定主动脉内膜增生情况.分别取外周血、动脉壁组织,并制备组织单细胞悬液,应用流式细胞仪检测DCs比例情况.用荧光定量RT-PCR技术检测DCs的CX3CR1表达情况.结果 AS大鼠内膜较正常对照大鼠内膜增生明显(P＜0.001),其外周血DCs分布明显减少(P＜0.05)且主动脉内DCs比例明显升高(P＜0.05).应用阿托伐他汀后AS大鼠内膜增生明显减轻(P＜0.05),其外周血DCs分布增多(P＜0.001)且主动脉壁内DCs比例明显降低(P＜0.001).AS大鼠DCs的CX3CR1基因相对表达量较对照组明显升高(P＜0.05),应用阿托伐他汀后CX3CR1基因相对表达量减少(P＜0.05).结论 AS大鼠主动脉内膜增生与DCs比例变化有关,DCs在AS大鼠主动脉内膜增生、管壁粥样硬化形成中可能起重要作用.阿托伐他汀可能通过抵制DCs向动脉内膜迁移,降低局部免疫炎症反应,此作用可能与DCs下调CX3CR1基因表达有关.     

阿托伐他汀对动脉粥样硬化大鼠热休克蛋白60、核转录因子-κB表达的影响

目的:探讨阿托伐他汀对动脉粥样硬化大鼠主动脉及心肌热休克蛋白60(HSP60)及核转录因子-κB(NF-κB)表达的影响。方法:选取普通级SD雄性大鼠18只,分为健康对照组(6只)、模型组(6只)和阿托伐他汀干预组(6只)。对照组给予基础饲料喂养;模型组给予高脂饲料喂养;阿托伐他汀干预组给予高脂饲料喂养12周后,阿托伐他汀干预4周(10 mg·kg~(-1)·d~(-1)灌胃)。实验终点处死大鼠,腹主动脉取血检测各组TC、TG、LDL-C,HE染色观察各组主动脉的病理改变,免疫组织化学法检测主动脉及心肌HSP60、NF-κB的蛋白表达。结果:模型组大鼠TC、LDL-C均高于对照组(均P0.01)。模型组大鼠主动脉组织内可见动脉粥样斑块形成;主动脉及心肌HSP60、NF-κB的表达均高于对照组(均P0.01)。阿托伐他汀干预组大鼠TC、LDL-C均低于模型组(均P0.01);主动脉组织内动脉粥样硬化斑块病变减轻;主动脉及心肌HSP60、NF-κB的表达均低于模型组(均P0.05)。结论:阿托伐他汀可调节血脂,降低HSP60的表达;并通过抑制NF-κB信号通路,减轻动脉粥样硬化病变。     

瑞舒伐他汀对载脂蛋白E基因敲除小鼠动脉粥样硬化中调节性T细胞的影响

目的观察瑞舒伐他汀对载脂蛋白E基因敲除小鼠动脉粥样硬化中调节性T细胞的影响。方法 C57BL/6J ApoE-/-小鼠18只,高脂饮食饲养8周建立动脉粥样硬化模型。随机分为高剂量组[瑞舒伐他汀5mg/（kg.d）灌胃]、低剂量组[瑞舒伐他汀2.5 mg/（kg.d）灌胃）]与模型组[生理盐水5 ml/（kg.d）灌胃）]。8周后处死小鼠取心脏及主动脉根部组织,Western blot检测病变处Foxp3、CD68、IL-6、IL-10表达。结果与模型组相比,高剂量组及低剂量组病变处Foxp3、IL-10表达增多,CD68、IL-6表达减少（P〈0.05）。高剂量组与低剂量组相比Foxp3、IL-10表达增多,CD68、IL-6表达减少（P〈0.05）。结论瑞舒伐他汀能阻止高脂饮食饲养的ApoE-/-小鼠动脉粥样硬化进展,其机制可能与增加病变处调节性T细胞的表达有关。     

养心氏片对动脉粥样硬化模型小鼠的作用机制研究

目的探讨养心氏片治疗动脉粥样硬化(AS)的可能作用机制。方法以高脂饲料喂养雄性载脂蛋白E基因敲除(ApoE~(-/-))小鼠12周,复制AS模型。将AS小鼠随机分成模型组,养心氏片高剂量组、中剂量组、低剂量组及阳性对照组,每组8只。另设雄性C57BL/6J小鼠8只作为正常对照组。养心氏片高剂量组、中剂量组、低剂量组及阳性对照组给药量分别相当于70 kg成人临床剂量的2倍、1倍、0.5倍及1倍。养心氏片高剂量组、中剂量组、低剂量组给予养心氏片,剂量分别为1.40 g/(kg·d)、0.70 g/(kg·d)、0.35 g/(kg·d)灌胃,阳性对照组给予阿托伐他汀剂量为2.57 mg/(kg·d)灌胃,共给药12周。采用苏木素-伊红(HE)染色法观察小鼠升主动脉病理学变化,Image J软件测定小鼠升主动脉斑块校正后斑块面积。采用实时定量PCR(qPCR)法检测各组小鼠主动脉组织核转录因子-κB(NF-κB)、单核细胞趋化蛋白-1(MCP-1)、血管内皮细胞黏附分子-1(VCAM-1)、白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)mRNA的表达。结果与模型组比较,养心氏片高剂量组、中剂量组、低剂量组及阳性对照组升主动脉斑块校正后斑块面积呈现不同程度的降低(P0.05),以养心氏片高剂量组小鼠升主动脉斑块校正后斑块面积最低,而养心氏片高剂量组小鼠升主动脉斑块校正后斑块面积与阳性对照组相比差异无统计学意义(P0.05)。与正常对照组比较,模型组小鼠主动脉组织NF-κB、MCP-1、VCAM-1、IL-6、TNF-αmRNA的表达水平明显升高(P0.05),各药物干预组小鼠主动脉组织NF-κB、MCP-1、VCAM-1、IL-6、TNF-αmRNA表达水平较模型组均显著降低(P0.05),与养心氏片高剂量组相比,养心氏片中剂量组及低剂量组小鼠主动脉NF-κB、MCP-1、VCAM-1、IL-6、TNF-αmRNA表达升高(P0.05),而养心氏片高剂量组小鼠主动脉NF-κB、MCP-1、VCAM-1、IL-6、TNF-αmRNA表达与阳性对照组相比差异无统计学意义(P0.05)。结论养心氏片可抗动脉粥样硬化,并具有剂量依赖性,养心氏片给药组以养心氏片高剂量组抗AS效果最佳,其机制可能与降低AS小鼠升主动脉斑块校正后斑块面积及下调主动脉NF-κB信号通路相关因子mRNA表达有关。     

Regulation of Sodium/Iodide Symporter

Reviews in Endocrine and Metabolic Disorders -     

L-type Ca channel facilitation mediated by H2O2-induced activation of CaMKII in rat ventricular myocytes

The Ca²⁺-dependent facilitation (CDF) of L-type Ca²⁺ channels, a major mechanism for force-frequency relationship of cardiac contraction, is mediated by Ca²⁺/CaM-dependent kinase II (CaMKII). Recently, CaMKII was shown to be activated by methionine oxidation. We investigated whether oxidation-dependent CaMKII activation is involved in the regulation of L-type Ca²⁺ currents (I_Ca,L) by H₂O₂ and whether Ca²⁺ is required in this process. Using patch clamp, I_Ca,L was measured in rat ventricular myocytes. H₂O₂ induced an increase in I_Ca,L amplitude and slowed inactivation of I_Ca,L. This oxidation-dependent facilitation (ODF) of I_Ca,L was abolished by a CaMKII blocker KN-93, but not by its inactive analog KN-92, indicating that CaMKII is involved in ODF. ODF was not affected by replacement of external Ca²⁺ with Ba²⁺ or presence of EGTA in the internal solutions. However, ODF was abolished by adding BAPTA to the internal solution or by depleting sarcoplasmic reticulum (SR) Ca²⁺ stores using caffeine and thapsigargin. Alkaline phosphatase, β-iminoadenosine 5′-triphosphate (AMP-PNP), an autophosphorylation inhibitor autocamtide-2-related inhibitory peptide (AIP), or a catalytic domain blocker (CaM-KIINtide) did not affect ODF. In conclusion, oxidation-dependent facilitation of L-type Ca²⁺ channels is mediated by oxidation-dependent CaMKII activation, in which local Ca²⁺ increases induced by SR Ca²⁺ release is required.     

脑蛋白水解物对鼠缺血半暗带神经元Na+-K+-ATP酶活性影响

目的探讨脑蛋白水解物对大鼠急性脑缺血再灌注损伤后缺血半暗带神经元Na~+-K~+-ATP酶活性的影响。方法选取270只雄性Wistar大鼠随机分为假手术组、模型组、干预组,三组大鼠根据缺血再灌注不同时间又随机分为缺血2 h再灌注6 h、24 h、48 h、72 h、7 d五个亚组,每个亚组18只大鼠。采用线栓法制备大鼠缺血2 h再灌注模型,仅干预组采用药物进行干预。分别于再灌注6 h、24 h、48 h、72 h、7 d后观察大鼠神经症状评分,相应时间断头取脑,测定缺血半暗带脑组织Na~+-K~+-ATP酶活性、脑组织含水量、脑梗死范围的变化。结果模型组大鼠缺血半暗带神经元Na~+-K~+-ATP酶活性于6 h开始下降,48 h达最小值,72 h稍有回升,7 d趋于稳定;干预组大鼠缺血2 h后再灌注24 h、48 h、72 h各时间点Na~+-K~+-ATP酶活性与模型组大鼠相应时间点比较差异有统计学意义(P0.05)。结论脑蛋白水解物可保护大鼠急性脑缺血再灌注损伤后缺血半暗带神经元,该作用可能与提高缺血半暗带神经元Na~+-K~+-ATP酶活性有关。     

Glomerular hyperfiltration during the onset of diabetes mellitus in two strains of diabetic mice (C57BL/6Jdb/db and C57BL/KsJdb/db)

Summary GFR estimated by the total clearence of⁵¹Cr-EDTA increases from 41 to 60 ml/min·m² at the onset and during the development of marked hyperglycaemia and obesity in female diabetic mice (db/db) of the C57BL/6J and the C57BL/KsJ strains (blood sugar rises from 160 to 400 mg/100 ml). GFR decreases slowly in older diabetic mice (>120 days old) approaching the control values (42±7 ml/ min·m²) and then decreases still further. The total clearance of¹⁴C-hippuric acid is unaltered indb/db mice and controls between 45 and 150 days of age (96±20 ml/min·m²). This suggests no alteration of RPF during the development of the diabetic syndrome. The glomerular hyperfiltration of diabetic mice lasts until they are 120 days old and shows no correlation with the different blood glucose levels typical for diabetic mice (db/db) of the two strains.     

有氧运动抑制衰老大鼠脑动脉平滑肌STOC/BKCa功能下调

目的　探讨有氧运动训练对衰老大鼠脑动脉平滑肌细胞全细胞K⁺电流、自发瞬时外向电流及大电导钙激活钾通道生物物理特性的影响。方法　19～21月龄雄性Wistar大鼠12只（老年组）,随机分为安静组和有氧运动组,并选用2月龄Wistar大鼠安静处理作为青年对照组。12周后取脑动脉,急性分离动脉平滑肌细胞。分别采用膜片钳全细胞模式、穿孔膜片钳模式和单通道内面向外模式观察运动对全细胞K⁺电流、自发瞬时外向电流和大电导钙激活钾通道门控特性的影响。结果　安静组全细胞K⁺电流密度及对Iberiotoxin敏感性降低;安静组自发瞬时外向电流幅值降低,频率无明显变化;安静组大电导钙激活钾通道平均开放概率和平均开放时间显著低于青年对照组,而平均关闭时间高于青年对照组;电压依赖性和钙敏感性亦显著下降;与安静组相比,有氧运动可以增加全细胞K⁺电流密度、自发瞬时外向电流幅值及大电导钙激活钾通道平均开放概率、电压依赖性和钙敏感性来实现对大鼠脑动脉平滑肌自发瞬时外向电流/大电导钙激活钾通道功能的保护作用。结论　长期规律有氧运动可以减弱衰老所致的大鼠脑动脉平滑肌细胞大电导钙激活钾通道功能下调,这可能是有氧运动改善衰老动脉功能的重要机制之一。     

Ca/calmodulin-dependent protein kinase II contributes to intracellular pH recovery from acidosis via Na/H exchanger activation

The Na⁺/H⁺ exchanger (NHE-1) plays a key role in pH_i recovery from acidosis and is regulated by pH_i and the ERK1/2-dependent phosphorylation pathway. Since acidosis increases the activity of Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) in cardiac muscle, we examined whether CaMKII activates the exchanger by using pharmacological tools and highly specific genetic approaches. Adult rat cardiomyocytes, loaded with the pH_i indicator SNARF-1/AM were subjected to different protocols of intracellular acidosis. The rate of pH_i recovery from the acid load (dpH_i/dt)—an index of NHE-1 activity in HEPES buffer or in NaHCO₃ buffer in the presence of inhibition of anion transporters—was significantly decreased by the CaMKII inhibitors KN-93 or AIP. pH_i recovery from acidosis was faster in CaMKII-overexpressing myocytes than in overexpressing β-galactosidase myocytes (dpH_i/dt: 0.195 ± 0.04 vs. 0.045 ± 0.010 min^− 1, respectively, n = 8) and slower in myocytes from transgenic mice with chronic cardiac CaMKII inhibition (AC3-I) than in controls (AC3-C). Inhibition of CaMKII and/or ERK1/2 indicated that stimulation of NHE-1 by CaMKII was independent of and additive to the ERK1/2 cascade. In vitro studies with fusion proteins containing wild-type or mutated (Ser/Ala) versions of the C-terminal domain of NHE-1 indicate that CaMKII phosphorylates NHE-1 at residues other than the canonical phosphorylation sites for the kinase (Ser648, Ser703, and Ser796). These results provide new mechanistic insights and unequivocally demonstrate a role of the already multifunctional CaMKII on the regulation of the NHE-1 activity. They also prove clinically important in multiple disorders which, like ischemia/reperfusion injury or hypertrophy, are associated with increased NHE-1 and CaMKII.     

Kupffer细胞对日本血吸虫病肉芽肿期CD4~+CD25~+T细胞的影响

目的探讨Kupffer细胞对日本血吸虫病肉芽肿期CD4+CD25+T细胞的影响。方法6～8周龄雌性C57BL/6J小鼠30只分为对照组、感染组与感染/氯化钆组3组,每组10只。感染组和感染/氯化钆组小鼠通过腹部感染尾蚴(10条/只),感染/氯化钆组于感染后第4周经尾静脉注射氯化钆,剂量为每次15mg/kg,每周2次;对照组通过尾静脉注射PBS。感染8周后流式细胞仪检测小鼠CD4+CD25+T细胞数量;免疫组织化学染色检测Foxp3的分布;ELISA检测血清细胞因子IL-4、IL-5、IL-10、TGF-β1与IFN-γ的水平,并进行肝功能检测。结果感染组小鼠CD4+CD25+T细胞数量为13.8%,感染/氯化钆组为9.3%;感染组IL-10为41.4pg/ml,感染/氯化钆组为22.6pg/ml;氯化钆可下调Foxp3的分布、血清丙氨酸氨基转移酶的水平,并减轻血吸虫肉芽肿周围的炎症反应。结论Kupffer细胞通过调控CD4+CD25+T细胞数量而参与日本血吸虫肉芽肿的形成。     

Alterations of Na/K-ATPase function in caveolin-1 knockout cardiac fibroblasts

Recent studies have demonstrated that the Na⁺/K⁺-ATPase is not only an ion pump, but also a membrane receptor that confers the ligand-like effects of cardiotonic steroids (CTS) such as ouabain on protein kinases and cell growth. Because CTS have been implicated in cardiac fibrosis, this study examined the role of caveolae in the regulation of Na⁺/K⁺-ATPase function and CTS signaling in cardiac fibroblasts. In cardiac fibroblasts prepared from wild-type and caveolin-1 knockout [Cav-1(−/−)] mice, we found that the absence of caveolin-1 did not affect total cellular amount or surface expression of Na⁺/K⁺-ATPase α1 subunit. However, it did increase ouabain-sensitive ⁸⁶Rb⁺ uptake. While knockout of caveolin-1 increased basal activities of Src and ERK1/2, it abolished the activation of these kinases induced by ouabain but not angiotensin II. Finally, ouabain stimulated collagen synthesis and cell proliferation in wild type but not Cav-1(−/−) cardiac fibroblasts. Thus, we conclude that caveolae are important for regulating both pumping and signal transducing functions of Na⁺/K⁺-ATPase. While depletion of caveolae increases the pumping function of Na⁺/K⁺-ATPase, it suppresses CTS-induced signal transduction, growth, and collagen production in cardiac fibroblasts.     

Na/K-ATPase inhibition by ouabain induces CaMKII-dependent apoptosis in adult rat cardiac myocytes

The positive inotropic effect produced by Na⁺/K⁺-ATPase inhibition has been used for the treatment of heart failure for over 200 years. Recently, administration of toxic doses of ouabain has been shown to induce cardiac myocyte apoptosis. However, whether prolonged administration of non-toxic doses of ouabain can also promote cardiac myocyte cell death has never been explored. The aim of this study was to assess whether non-toxic doses of ouabain can induce myocyte apoptosis and if so, to examine the underlying mechanisms. For this purpose, cardiac myocytes from rat and cat, two species with different sensitivity to digitalis, were cultured for 24 h in the presence or absence of 2 µM (rat) and 25 nm-2 µM ouabain (cat). Cell viability and apoptosis assays showed that ouabain produced, in the rat, a 43 ± 5% decrease in cell viability due to apoptosis (enhanced caspase-3 activity, increased Bax/Bcl-2 and TUNEL-positive nuclei) and necrosis (LDH release and trypan blue staining). Similar results were obtained with 25 nM ouabain in the cat. Ouabain-induced reduction in cell viability was prevented by the NCX inhibitor KB-R7943 and by the CaMKII inhibitors, KN93 and AIP. Furthermore, CaMKII overexpression exacerbated ouabain-induced cell mortality which in contrast was reduced in transgenic mice with chronic CaMKII inhibition. However, KN93 failed to affect ouabain-induced inotropy. In addition, whereas ERK½ inhibition with PD-98059 had no effect on cell mortality, PI3K inhibition with wortmannin, exacerbated myocyte death. We conclude that ouabain triggers an apoptotic cascade that involves NCX and CaMKII as a downstream effector. Ouabain simultaneously activates an antiapoptotic cascade involving PI3K/AKT which is however, insufficient to completely repress apoptosis. The finding that KN93 prevents ouabain-induced apoptosis without affecting inotropy suggests the potential use of CaMKII inhibitors as an adjunct to digitalis treatment for cardiovascular disease.