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1.
Due to the potential for dietary fat source to alter plasma lipids and tissue antioxidant status, we hypothesized that blends of saturated, n-6 and n-3 fats with cholesterol would affect LDL and tissue susceptibility to in vitro oxidation. The effects of dietary fat blends of butter (B), beef tallow (T), soybean oil (SBO) or menhaden oil (MO) and cholesterol on systolic blood pressure (SBP), plasma lipoproteins and tissue susceptibility to glutathione (GSH) depletion and lipid peroxidation (TBARS) were examined in spontaneously hypertensive (SHR) and Wistar Kyoto (WKY) rats. SBP in SHRs was higher (p < 0.001) than in WKYs at 13-weeks of age but was not altered by dietary fat or cholesterol. LDL- and HDL-cholesterol were greater (p < 0.001) in WKY than SHR. LDL-cholesterol and (VLDL7- + LDL-cholesterol)/HDL-cholesterol ratios were reduced in MO vs. B, T and SBO groups. HDL-cholesterol levels tended to be lower and greater in B and MO groups, respectively vs. T and SBO groups. Initial LDL fluorescence was greater (p < 0.001) in high- vs. low-cholesterol groups. The change in LDL fluorescence was reduced (p < 0.001) in high-cholesterol groups, and MO vs. B, T and SBO rats. MO fed rats had reduced (p < 0.001) RBC, heart and liver GSH depletion and reduced (p < 0.01) tissue TBARS and RBC MDA production. In summary, a moderate level of dietary MO did not increase tissue and LDL in vitro oxidizability in SHR and WKY rats. High dietary cholesterol exhibited a protective effect against in vitro oxidation of LDL and selected tissues.  相似文献   

2.
暴露在低氧环境下,可能会引起胃肠功能障碍和摄食量下降,打破骨骼肌蛋白质合成和分解平衡,造成骨骼肌萎缩。为探讨低氧环境下骨骼肌的萎缩是低氧环境引起的还是低氧诱发的摄食量减少所致,本研究检测大鼠腓肠肌中低氧时蛋白质合成与分解相关基因的蛋白质表达。将21只雄性SD大鼠,随机分为3组:常氧对照组、低氧组(氧浓度为12.4%,模拟海拔4 000 m高度)和配对组(大鼠的摄食量与低氧组前1 d的摄食量相同),每组7只,每天记录大鼠体重和摄食量。4周后,HE染色法观察腓肠肌肌纤维形态,Western印迹测试相关蛋白质水平。低氧组和配对组摄食量在低氧干预初期,较常氧对照组有显著性下降(P<0.05),干预后期差异不明显;干预期间,低氧组大鼠体重平均增加量(102.10 g)、体重(341.20 ± 16.75 g)、肌肉总量(226.83 ± 8.33 g)和腓肠肌肌纤维横截面积(12.67 ± 1.83 mm)较常氧对照组(128.00 g;377.50 ± 20.75 g;260.50 ± 9.35 g;15.78 ± 2.38 mm)和配对组(119.40 g;375.86 ± 11.30 g;262.29 ± 7.90 g;15.71 ± 2.82 mm)均显著下降,配对组较常氧对照组无显著性差异;4周干预后,与常氧对照组相比,低氧组大鼠腓肠肌中与低氧相关的HIF1α显著增加(1.42 ± 0.19, P<0.05),Akt和p-Akt/Akt显著降低 (1.44 ± 0.13; 0.47 ± 0.08, P<0.05),配对组上述3种指标相对表达量均无显著性差异;在蛋白质合成方面,低氧组mTOR较常氧对照组显著下降(0.63 ± 0.18, P<0.05),配对组较常氧对照组差异不明显;低氧组腓肠肌中,4EBP1(1.14 ± 0.14)和p70S6K1(1.14 ± 0.11)较配对组显著下降(P<0.05)。在蛋白质分解方面,低氧组p-FoxO1和p-FoxO1/FoxO1比值较常氧对照组显著下降(0.71 ± 0.15; 0.78 ± 0.14, P<0.05);低氧组大鼠腓肠肌中,Atrogin1、MuRF1、Beclin1、LC3Ⅰ及LC3Ⅱ/Ⅰ比值均高于常氧对照组(1.35 ± 0.12; 1.30 ± 0.22; 1.17 ± 0.11; 1.03 ± 0.11; 1.35 ± 0.13, P<0.05);配对组与常氧对照组间无明显差异。低氧环境下骨骼肌中蛋白质合成相关基因表达减少,蛋白质分解相关基因表达增加,造成骨骼肌萎缩,体重下降,此变化与摄食量减少无关。  相似文献   

3.
暴露在低氧环境下,可能会引起胃肠功能障碍和摄食量下降,打破骨骼肌蛋白质合成和分解平衡,造成骨骼肌萎缩。为探讨低氧环境下骨骼肌的萎缩是低氧环境引起的还是低氧诱发的摄食量减少所致,本研究检测大鼠腓肠肌中低氧时蛋白质合成与分解相关基因的蛋白质表达。将21只雄性SD大鼠,随机分为3组:常氧对照组、低氧组(氧浓度为12.4%,模拟海拔4 000 m高度)和配对组(大鼠的摄食量与低氧组前1 d的摄食量相同),每组7只,每天记录大鼠体重和摄食量。4周后,HE染色法观察腓肠肌肌纤维形态,Western印迹测试相关蛋白质水平。低氧组和配对组摄食量在低氧干预初期,较常氧对照组有显著性下降(P<0.05),干预后期差异不明显;干预期间,低氧组大鼠体重平均增加量(102.10 g)、体重(341.20 ± 16.75 g)、肌肉总量(226.83 ± 8.33 g)和腓肠肌肌纤维横截面积(12.67 ± 1.83 mm)较常氧对照组(128.00 g;377.50 ± 20.75 g;260.50 ± 9.35 g;15.78 ± 2.38 mm)和配对组(119.40 g;375.86 ± 11.30 g;262.29 ± 7.90 g;15.71 ± 2.82 mm)均显著下降,配对组较常氧对照组无显著性差异;4周干预后,与常氧对照组相比,低氧组大鼠腓肠肌中与低氧相关的HIF1α显著增加(1.42 ± 0.19, P<0.05),Akt和p-Akt/Akt显著降低 (1.44 ± 0.13; 0.47 ± 0.08, P<0.05),配对组上述3种指标相对表达量均无显著性差异;在蛋白质合成方面,低氧组mTOR较常氧对照组显著下降(0.63 ± 0.18, P<0.05),配对组较常氧对照组差异不明显;低氧组腓肠肌中,4EBP1(1.14 ± 0.14)和p70S6K1(1.14 ± 0.11)较配对组显著下降(P<0.05)。在蛋白质分解方面,低氧组p-FoxO1和p-FoxO1/FoxO1比值较常氧对照组显著下降(0.71 ± 0.15; 0.78 ± 0.14, P<0.05);低氧组大鼠腓肠肌中,Atrogin1、MuRF1、Beclin1、LC3Ⅰ及LC3Ⅱ/Ⅰ比值均高于常氧对照组(1.35 ± 0.12; 1.30 ± 0.22; 1.17 ± 0.11; 1.03 ± 0.11; 1.35 ± 0.13, P<0.05);配对组与常氧对照组间无明显差异。低氧环境下骨骼肌中蛋白质合成相关基因表达减少,蛋白质分解相关基因表达增加,造成骨骼肌萎缩,体重下降,此变化与摄食量减少无关。  相似文献   

4.
目的:研究低氧性大鼠肺动脉平滑肌细胞(PASMC)的增殖、凋亡与丝裂原活化蛋白激酶(MAPK)关系。方法:用组织酶消化法获取肺动脉平滑肌细胞(PASMCs),进行原代培养;采用普通光学显微镜和免疫荧光染色法,分别鉴定PASMCs;选择处于对数生长期的4~6代PASMCs,随机分为7组进行造模:常氧对照组(N)、低氧组(H)、DM-SO组(D)、U0126组(U)、SB203580组(S)、Anisomycin组(A)、Staurosporine Aglycone组(SA);N组加入10%培养基后置于常氧培养箱中,其它各组分别加入含相应药物的10%培养基后置于低氧培养箱(3% O2,5% CO2,37℃)中,造模时间均为48 h。CCK-8法检测各组PASMCs增殖情况;TUNEL法测定各组PASMCs凋亡情况。结果:与N组相比,H组PASMCs的OD值显著上调(0.990 ±0.041 vs 1.143 ±0.033,P < 0.01),凋亡指数没有明显变化(4.913 ±0.451 vs 5.452 ±0.557,P > 0.05);与H组相比,D组PASMCs的OD值和凋亡指数均无显著变化(1.143 ±0.033 vs 1.142 ±0.049,5.452 ±0.557 vs 5.402 ±0.651,均P > 0.05);U组PASMCs的OD值下降,凋亡指数升高(1.143 ±0.033 vs 0.985 ±0.078,5.452 ±0.557 vs 10.145 ±2.545,均P < 0.01);S组PASMCs OD值上调,凋亡指数明显下调(1.143 ±0.033 vs 1.295 ±0.039,5.452 ±0.557 vs 3.093 ±0.409,均P < 0.01);A组PASMCs的OD值下降,凋亡指数升高(1.143 ±0.033 vs 0.347 ±0.067,5.452 ±0.557 vs 25.753 ±1.262,均P < 0.01);SA组PASMCs OD值上调,凋亡指数下调(1.143 ±0.033 vs 1.685 ±0.100,5.452 ±0.557 vs 1.700 ±0.095,均P < 0.01)。结论:低氧对PASMCs增殖和凋亡的调控与MAPK信号通路有关。  相似文献   

5.
目的探讨间充质细胞(MSC)外泌体对低氧条件下胰岛内皮细胞(MS-1)血管生成的影响。 方法MSC无血清低氧条件培养48?h,超滤离心法富集条件培养基中的外泌体,采用电镜和Western Blot的方法进行鉴定;通过血管形成试验比较分析不同条件下:常氧培养组(NOR组,21﹪O2、5﹪CO2)、低浓度氧培养组(HYP组,2﹪O2、5﹪CO2)、外泌体+低浓度氧共培养组(HYP+EXO组,2﹪O2、5﹪CO2),MS-1细胞的血管形成能力;image J软件分析血管形成长度;PCR、Q-PCR检测血管内皮生长因子(VEGF) RNA水平的表达,Western Blot检测VEGF、HIF1α蛋白水平表达以及mTOR信号通路激活情况。采用单因素方差分析和SNK-q检验统计学分析。 结果超滤离心法富集的MSC条件培养基中的外泌体,大小为30 ~ 100 nm,表达CD9,CD63,CD81等外泌体表面标志物;血管形成试验结果显示,低氧促进MS-1血管生成,HYP+EXO组形成明显的血管网状结构;HYP+EXO组血管形成相对长度(2386.0±137.7)像素与NOR组(393.3±174.2)像素和HYP组(1467.0±230.0)像素相比增强,差异有统计学意义(t = 12.30,P?= 0.0065;t = 15.74,P = 0.0040);PCR结果显示,HYP+EXO组VEGF相对表达量(20.26±9.972)较常氧对照组(1.000)和低氧组(6.521±3.501)均增强,差异有统计学意义(t = 5.462,P = 0.0009;t = 4.238,P = 0.0038);同时,Western Blot结果显示VEGF蛋白水平表达升高,HIF1-α表达上调,mTOR发生磷酸化。 结论MSC外泌体可促进低氧条件下的小鼠胰岛内皮细胞血管生成。MSC外泌体可能通过上调HIF1-α,调节VEGF表达,激活mTOR信号通路,促进胰岛内皮细胞血管生成。  相似文献   

6.
白藜芦醇是天然存在的沉默信息调节因子2相关酶1(sirtuin1,SIRT1)小分子激动剂,其肾的保护作用已在多种肾疾病动物模型中得到了验证。然而,白藜芦醇是否能够改善力竭训练导致的大鼠肾损伤,以及是否通过SIRT1/NF κB信号通路调节运动性肾损伤大鼠肾炎症反应,尚缺乏系统研究。本研究将32只SD大鼠随机分为安静对照组(Con组),白藜芦醇组(Rsv组),力竭运动组(Ex组),力竭运动+白藜芦醇组(Ex+Rsv组)。Rsv和Ex+Rsv组每天灌胃50 mg/kg体重剂量的白藜芦醇, Ex和Ex+Rsv组进行4周力竭训练,最后1次训练后24 h取材。本研究结果显示,与Con组相比,Ex组大鼠Scr(175.66 ± 16.08 vs.153.34 ± 8.67,P < 0.01)、BUN(6.67 ± 0.53 vs.5.37 ± 019,P < 0.01)和尿NGAL(9.01 ± 0.18 vs.7.48 ± 0.31,P < 0.01)水平均显著升高,Ex组大鼠肾组织NF κB P65在蛋白质水平表达显著升高(0.77 ± 010 vs. 0.27 ± 0.03,P < 0.01);各组大鼠肾组织SIRT1在蛋白质水平表达上,Rsv组显著高于Con组(0.90 ± 0.14 vs. 0.43 ± 0.15,P < 0.05),Ex+Rsv组显著高于Ex组(1.0 ± 0.28 vs. 0.38 ± 0.12,P< 001);与Ex组相比,Ex+Rsv组大鼠肾组织NF-κB P65(0.57 ± 0.13 vs. 0.77 ± 0.10,P < 0.05)和Ac-NF-κB P65(0.52 ± 0.13 vs. 0.78 ± 0.11,P < 0.05)在蛋白质水平表达显著降低。以上结果表明,4周大强度力竭运动导致大鼠出现运动性肾损伤,并激活大鼠肾NF-κB的表达。白藜芦醇可显著提高大鼠肾组织SIRT1在蛋白质水平的表达,并增加脱乙酰化作用,降低NF-κB P65蛋白质乙酰化修饰水平,进一步降低NF-κB的表达。白藜芦醇减轻力竭训练致大鼠肾的炎症反应的机制可能与SIRT1/NF-κB通路有关。  相似文献   

7.
目的分析沉默G蛋白偶联受体48 (Gpr48)基因表达对皮肤鳞状细胞癌(SCC)蛋白激酶C (PKC)信号通路及细胞侵袭能力的影响。 方法构建ShRNA感染皮肤SCC细胞株A431,设计干扰Gpr48表达shRNA(shRNA-Gpr48组)及阴性对照shRNA-NC组,采用实时定量反转录聚合酶联反应(RT-PCR)检测Gpr48相对表达量;以蛋白印迹法(Western Blot)测定PKC相关抗体蛋白表达情况,进行Transwell小室实验检测细胞侵袭能力,总结Gpr48缺失对三丙胺(TPA)刺激A431细胞株PKC活化及细胞侵袭能力的影响,为SCC靶向治疗提供参照。组间比较采用独立样本t检验。 结果qRT-PCR结果:shRNA-Gpr48组Gpr48相对表达量(0.27±0.06)低于shRNA-NC组(1.01±0.12),差异具有统计学意义(t?= 17.441,P?< 0.01),shRNA-Gpr48组p-PKCδ (0.463±0.035)低于shRNA-NC组(0.721±0.074),shRNA-?Gpr48组NF-κB p65 mRNA (0.631±0.079)低于shRNA-NC组(0.834±0.102),差异具有统计学意义(t?= 9.966、4.975,P均< 0.01),Notch1 mRNA(0.981±0.037)高于shRNA-NC组(0.562±0.041),差异具有统计学意义(t?= 23.991,P?< 0.01);Western Blot结果:shRNA-Gpr48组p-PKCδ(0.221±0.034)低于shRNA-NC组(0.292±0.046)、NF-κB p65蛋白表达(0.512±0.047)低于shRNA-NC组(0.636±0.051),差异具有统计学意义(t?= 3.925,5.653,P均< 0.01),Notch1(0.524±0.063)高于shRNA-NC组(0.421±0.076),差异具有统计学意义(t?= 3.299,P?< 0.01);shRNA-Gpr48组侵袭细胞率为(35.03±1.54)﹪,低于shRNA-NC组的(51.83±2.76)﹪,差异具有统计学意义(t?= 16.809,P?< 0.01)。 结论沉默Gpr 48缺失表达可能通过抑制PKC活化,降低p-PKCδ、NF-κB p65表达,上调抑癌基因Notch1表达,抑制癌细胞增殖、侵袭。  相似文献   

8.
氧化低密度脂蛋白(oxygenized low density lipoprotein, ox-LDL)诱导人脐静脉内皮细胞(human umbilical vein endothelial cells, HUVECs)损伤有助于动脉粥样硬化(atherosclerosis, AS)的发展。但ox-LDL对HUVECs自噬的影响及机制尚不清楚。为探究其机制,采用体外培养HUVECs,建立ox-LDL损伤模型。透射电子显微镜观察HUVECs中自噬体的变化;Western印迹法检测p-AMPK、AMPK、p-mTOR、mTOR及Beclin1、LC3-II、P62的表达。结果显示,与对照组比较,透射电子显微镜下观察到ox-LDL组的自噬体明显增多。Western印迹结果显示,与对照组比较,ox-LDL组Beclin1(0.81±0.04 vs. 1.83±0.11,P<0.01)、LC3-II(0.80±0.06 vs. 1.61±0.06, P<0.01)和P62(0.65±0.10 vs. 1.64±0.17, P<0.01)表达显著增高。ox-LDL和BafilomycinA1共同干预组Beclin-1(3.15±0.15 vs. 3.17±0.13, P>0.05)、LC3-II(2.95±0.12 vs. 2.96±0.12, P >0.05)和P62(3.26±0.15 vs. 3.19±0.15, P>0.05)表达与BafilomycinA1组无显著差异,ox-LDL未使自噬起始增加,可能是降解受损导致自噬体的积累。与对照组比较,ox-LDL增加p-AMPK (0.47±0.03 vs. 0.96±0.03, P<0.01)表达,并降低p-mTOR(0.86±0.04 vs. 0.25±0.05, P<0.01)表达。单独阻断mTOR时, Beclin-1(0.81±0.05 vs. 2.19±0.17, P<0.01)、LC3-II(0.76±0.13 vs 2.00±0.05, P<0.01)和P62(0.74±0.12 vs. 1.94±0.11, P<0.01)表达显著增加。亮氨酸(Leucine)可增加p-mTOR(0.87±0.11 vs. 1.67±0.07, P<0.01)表达,并降低Beclin-1(0.81±0.05 vs. 0.37±0.03, P<0.01)、LC3-II(0.76±0.13 vs. 0.41±0.02, P<0.01)和P62(0.76±0.10 vs. 0.44±0.04, P<0.01)表达,但ox-LDL可使Leucine预处理后的p-mTOR(1.67±0.11 vs. 0.82±0.02, P<0.01)表达显著降低,并且Beclin-1(0.37±0.03 vs. 0.78±0.04, P<0.01)、LC3-II(0.41±0.02 vs. 0.78±0.02, P<0.01)和P62(0.44±0.04 vs. 0.74±0.04, P<0.01)表达显著增加。说明mTOR参与ox-LDL诱导的自噬。与ox-LDL组相比,ox-LDL和Si-AMPK共同处理组p-mTOR(0.25±0.05 vs. 0.46±0.03, P<0.01)表达增加以及Beclin-1(1.97±0.04 vs. 1.26±0.12, P<0.01)、LC3-II(1.42±0.10 vs. 0.95±0.05, P<0.01)和P62(1.58±0.09 vs. 0.98±0.11, P<0.01)表达降低。以上结果表明,ox-LDL通过AMPK/mTOR途径诱导HUVECs发生自噬,并且导致自噬体的积累。  相似文献   

9.
In a previous study, high nuclear estrogen receptor concentrations in the preoptic area (POA) were found on Day 16 of pregnancy to prime females to respond to a subsequent low dose of estradiol benzoate (EB) after hysterectomy-ovariectomy by exhibiting maternal behavior in 48 hr. Receptor concentrations in the POA were found to be higher than those in the hypothalamus (HYP). The present study investigated when nuclear estrogen receptors increase during pregnancy in POA and when the difference in receptor concentrations between POA and HYP occurs. An attempt was made to reproduce these pregnancy changes with a 16-day treatment of estrogen and progesterone in ovariectomized (OVX), nulliparous rats. In Experiment 1, we measured cytosol and nuclear estrogen receptor concentrations in the POA and HYP of female rats during pregnancy. Nuclear receptor concentrations in the POA increased beginning on Day 10, increased again on Day 16, and continued at this high level for the remainder of pregnancy. Nuclear estrogen receptor concentrations in the HYP remained at a lower level throughout most of pregnancy until Day 22 when they increased significantly. In Experiment 2, we tested the maternal behavior and measured estrogen receptor concentrations in OVX, steroid-primed, nulliparous rats after hysterectomy (H) and EB treatment. While 90% of estradiol (E) + progesterone (P)-primed females displayed short-latency maternal behavior 48 hr after H and EB treatment, 46% of E + vehicle (V)-treated controls were maternal. At 0 hr (prior to H and EB treatment), there was a significantly larger nuclear receptor accumulation in the POA but significantly attenuated receptor binding in the HYP. P treatment significantly affected cytosol and nuclear estrogen receptor dynamics. Differences in nuclear estrogen receptor concentrations were shown to be based on the number of available binding sites and not to changes in receptor affinity for estradiol.  相似文献   

10.
This study investigated sex differences in chronic social stress-induced pressor and behavioral responses in normotensive and prehypertensive rats. Adult Wistar and borderline hypertensive (BH) rats (offspring of Wistar dams and spontaneously hypertensive sires) of both sexes were exposed to crowding stress (200 cm2/rat, 5 rats/cage) for 6 weeks. Controls were kept 4 rats/cage (480 cm2/rat). Blood pressure (BP) and open field activity were determined before experiment and after 1, 3 and 6 weeks of stress. Basal BP of BH rats was higher than in Wistar (p < 0.001) in both males and females. Horizontal and vertical activity of BH males and females was elevated vs. Wistar (p < 0.01) and females in both phenotypes were more active than the respective males (p < 0.01). Crowding resulted in delayed between-session habituation and significant elevation of BP only in BH males (143 ± 2 vs. 134 ± 3 mmHg in controls after 6-week crowding). No changes of BP were observed in crowded females of both phenotypes regardless of their delayed between-session habituation. Thus chronic social stress produced by crowding seems to represent a significant risk factor for development of stress-related hypertension only in males with genetic predisposition to high blood pressure while females of both phenotypes responded to stress by impaired between-session habituation.  相似文献   

11.
上调中枢补体C1q/肿瘤坏死因子相关蛋白4(complement-C1q/tumor necrosis factor-related protein 4, CTRP4) 可以改变下丘脑食欲调节相关蛋白的表达,抑制小鼠摄食且降低其体重。然而,CTRP4如何调控食欲调节相关蛋白的表达尚不清楚。本研究通过上调小鼠神经母细胞瘤细胞(N2a)中的CTRP4,探讨CTRP4调控食欲调节相关蛋白的潜在作用机制。通过对N2a细胞未做干预、转染绿色荧光蛋白(green fluorescent protein, GFP)重组腺病毒和CTRP4过表达重组腺病毒,将其分为空白对照组(Control组)、阴性对照组(Ad-GFP组)及CTRP4过表达组(Ad-CTRP4组)。干预72 h时,用实时荧光定量PCR(RT-PCR)检测细胞CTRP4 mRNA表达,采用Western 印迹检测细胞CTRP4、Pomc、Npy、p-STAT3/t-STAT3、TNF-α、IL-6、SOCS3在蛋白质水平的表达。结果显示,与对照组相比,Ad-CTRP4组的CTRP4 mRNA水平(26 258.44±10 403.47 vs. 1.81±0.79 vs. 1.00±0.00, P<0.01)及蛋白质水平显著增加(10.44±7.99 vs.0.64±0.62 vs. 1.00±0.75, P<0.01)。Ad-CTRP4组的p-STAT3/t-STAT3(3.38±1.70 vs. 0.86±0.57 vs. 1.00±0.63, P<0.01)和Pomc(1.81±0.19 vs. 1.15±0.18 vs. 1.00±0.22, P<0.01)表达均显著增高;SOCS3(0.69±0.15 vs. 1.00±0.12 vs. 1.00±0.07, P<0.01),IL-6(0.40±0.19 vs. 1.03±0.17 vs. 1.00±0.16, P<0.01),TNF.α(0.39±0.27 vs. 1.05±0.46 vs. 1.00±0.29, P<0.05)及Npy (0.55±0.14 vs. 1.21±0.38 vs. 1.00±0.24, P<0.05)表达均显著下降。上述结果提示,在N2a细胞中,上调CTRP4可能通过抑制炎症因子TNF-α和IL-6,降低负性调节因子SOCS3的表达,增加STAT3磷酸化表达水平,从而调控食欲调节相关蛋白的表达。  相似文献   

12.
The ability of a number of hormones to activate cellular responses in a variety of cells declines with age. The mechanisms responsible for these alterations are complex and incompletely understood. Rat adipocytes have served as an important model to study blunted responses to stimulatory hormones which function by activating cAMP accumulation. We have previously found that the blunted lipolytic response of adipocytes from older rats to the beta adrenergic receptor agonist isoproterenol appeared to be due to a lessened ability of isoproterenol to activate cAMP accumulation. Further, the blunted response to isoproterenol was apparently caused by an accentuated inhibition of lipolysis, mediated by adenosine receptors activated by endogenously released adenosine. The present studies were designed to test and extend those conclusions. We have utilized forskolin to augment the cAMP accumulation that occurs in the presence of isoproterenol. Isoproterenol-activated lipolysis was greater in adipocytes from 2 month old rats compared with those from 12 month old rats (603 +/- 32 vs 450 +/- 29 nmol/10(5) cells/hr, P less than 0.01). However, in the presence of forskolin (10(-6) M), there was no significant difference in the response to isoproterenol between the two groups (646 +/- 23 vs 615 +/- 29 nmoles/10(5) cells/hr). As we had seen previously, the adenosine receptor agonist phenylisopropyladenosine more effectively inhibited lipolysis in the adipocytes from older rats. We now also find that PGE1 more efficaciously inhibits lipolysis in the cells from older rats. These data confirm that diminished cAMP accumulation in adipocytes from older rats appears to be a rate-limiting alteration in the regulation of lipolysis.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

13.
Sex differences in blood pressure are evident in experimental models and human subjects, yet the mechanisms underlying this disparity remain equivocal. The current study sought to define the extent of male-female differences in the circulating and tissue renin-angiotensin aldosterone systems (RAASs) of congenic mRen(2). Lewis and control Lewis rats. Male congenics exhibited higher systolic blood pressure than females [200 +/- 4 vs. 146 +/- 7 mmHg, P < 0.01] or Lewis males and females [113 +/- 2 vs. 112 +/- 2 mmHg, P > 0.05]. Plasma ANG II levels were twofold higher in male congenics [47 +/- 3 vs. 19 +/- 3 pM, P < 0.01] and fivefold higher than in male or female Lewis rats [6 +/- 1 vs. 6 +/- 1 pM]. ANG I levels were also highest in the males; however, plasma ANG-(1-7) was higher in female congenics. Male congenics exhibited greater circulating renin and angiotensin-converting enzyme (ACE) activities, as well as angiotensinogen, than female littermates. Renal cortical and medullary ANG II levels were also higher in the male congenics versus all the other groups; ANG I was lower in the males. Cortical ACE2 activity was higher in male congenics, yet neprilysin activity and protein were greater in the females, which may contribute to reduced renal levels of ANG II. These data reveal that sex differences in both the circulating and renal RAAS are apparent primarily in the hypertensive group. The enhanced activity of the RAAS in male congenics may contribute to the higher pressure and tissue injury evident in the strain.  相似文献   

14.
15.
创伤性脑损伤(traumatic brain injury,TBI)是极为常见的外伤性疾病,致死率和致残率很高。存活者伴随的空间认知功能障碍,给患者家庭和社会造成了极大的负担。目前,对TBI造成的空间记忆障碍缺乏系统研究。脑损伤后海马组织与记忆有关的分子以及组成神经元骨架的分子如何变化研究甚少。本研究采用Wistar大鼠为研究对象,并随机将其分为假手术(sham)组和创伤性脑损伤(TBI)组。TBI组再按致伤后时间长短分为6 h、12 h、24 h、72 h、15 d五个亚组。TBI组应用PinPointTM颅脑撞击器撞击而致伤,sham组不撞击。采用Morris水迷宫评价实验动物空间记忆能力;干湿重法测定脑含水量,评估脑水肿与海马水通道蛋白4(aquaporin-4,AQP-4)的相关性;海马神经元特异性核蛋白(neuron specific nuclear protein,NeuN)标记和免疫荧光检测评估TBI致大鼠神经元丢失情况;通过Western印迹检测TBI致海马骨架相关蛋白质和记忆相关蛋白质含量变化。本研究证实,与sham组相比,TBI组大鼠潜伏期明显增加[(61.98±12.82) s vs.(28.32±8.52) s,n=5,P<0.01,day 15],探索时间明显缩短[(36.98±0.37) s vs. (73.68±5.09) s,n=5,P<0.01,day15],表明脑创伤损害了动物的空间参考记忆能力和空间工作记忆能力。与sham组相比,TBI组大鼠海马AQP-4在蛋白质水平上的表达和脑含水量持续升高,15 d恢复正常;在12 h[(3.78±0.74),(83.78±0.35)%]和72 h[(3.49±0.85),(82.28±0.63)%]均形成两个波峰,n=5,P均<0.01,表明继发性脑损伤与持续脑水肿和海马AQP-4在蛋白质上的高表达有关。与sham组相比,NeuN标记和免疫荧光检测发现,TBI后24 h 致大鼠海马神经元丢失严重[(198.2±8.002) vs.(297.2±6.866) cells/mm2, n=5,P<0.01],表明TBI动物的海马功能受损。与sham相比,TBI组海马神经元树突标志物微管结合蛋白2(microtubule associated proein 2,MAP2)和突触前终末特异性标记物突触素(synaptophysin,SYN)在蛋白质水平均伤后逐步降低(n=5,P均<0.01),72 h[(0.55±0.05) vs.(1.27±0.08), (0.52±0.14) vs.(1.06±0.16), n=5,P均<0.01]降低最明显;TBI组形成神经元纤维缠结主要成分的过度磷酸化tau(ser404),伤后逐步升高,72 h[(1.25±0.11)vs. (0.33±0.07), n=5,P<0.01]升高最明显。 MAP2、SYN和过度磷酸化的tau(ser404)检测指标的改变,表明脑损伤致神经元受损,神经元生长和损伤修复能力减弱,最终导致神经元骨架破环,TBI损害了动物的海马空间记忆能力。与sham组相比,TBI组大鼠海马环磷酸腺苷反应元件结合蛋白(cAMP response element binding protein,CREB)和磷酸化CREB ser133(phosphorylated CREB Ser133, pCREB Ser133)含量降低明显(n=5,P均<0.05),表明脑损伤动物海马的存储记忆能力减弱;TBI组大鼠海马一般调控阻遏蛋白激酶2(general control nonderepressible 2 kinase,GCN2)蛋白质升高明显(n=5,P均<0.05),表明脑损伤动物海马将新信息转化成长期记忆能力下降。本研究提示,创伤性脑损伤可使大鼠海马神经元骨架破坏,进而导致在学习记忆过程中起重要作用的分子蛋白质下调,抑制记忆储存的蛋白质(GCN2)上调,促使学习记忆功能障碍。  相似文献   

16.
Nogo-B在血管损伤、组织修复和炎症反应中发挥重要作用。然而,Nogo-B在动脉粥样硬化中的作用仍不明确。本研究拟在巨噬细胞中探讨Nogo-B对巨噬细胞泡沫化的影响。在RAW264.7细胞中沉默Nogo-B后,采用氧化低密度脂蛋白(Ox-LDL)或DiI修饰的Ox-LDL诱导巨噬细胞泡沫化;通过激光共聚焦显微镜观察巨噬细胞中荧光脂质,并在透射电镜下观察各组细胞中自噬泡;采用Western 印迹分析Plin2、p62和LC3-II的蛋白质水平;采用实时荧光定量PCR检测p62 mRNA水平;采用氯喹处理以及mRFP-GFP-LC3双荧光体系分析自噬流功能;进一步过表达Nogo-B后,比较巨噬细胞中脂质负荷程度以及Plin2、p62和LC3-II的蛋白质水平。结果显示,DiI-Ox-LDL处理后,Nogo-B沉默组细胞中脂质负荷程度高于对照组(2.34±0.67 vs. 0.69±0.14,P<0.05);Ox-LDL处理后,Nogo-B沉默组细胞中自噬泡数量(8.67±0.58 vs. 4.33±0.58,P<0.01)、Plin2(4.65±0.50 vs. 3.24±0.71,P<0.05)、p62(10.13±1.79 vs. 5.76±1.84,P<0.05)和LC3-II(4.38±0.20 vs. 2-33±1.56,P<0.01)的蛋白质水平均显著高于对照组,而p62 mRNA水平无差异(P>0.05);进一步研究发现,Nogo-B沉默组的自噬流被抑制了;过表达Nogo-B后,虽然p62蛋白质水平无明显变化,但是细胞中脂质负荷程度显著低于对照组(1.68±1.06 vs. 4.94±0.70,P<0.05),Plin2和LC3-II的蛋白质水平也明显降低。上述结果表明,Nogo-B通过促进自噬流抑制了Ox-LDL诱导的巨噬细胞泡沫化,Nogo-B可能具有抗动脉粥样硬化的作用。  相似文献   

17.
创伤性脑损伤(traumatic brain injury,TBI)是极为常见的外伤性疾病,致死率和致残率很高。存活者伴随的空间认知功能障碍,给患者家庭和社会造成了极大的负担。目前,对TBI造成的空间记忆障碍缺乏系统研究。脑损伤后海马组织与记忆有关的分子以及组成神经元骨架的分子如何变化研究甚少。本研究采用Wistar大鼠为研究对象,并随机将其分为假手术(sham)组和创伤性脑损伤(TBI)组。TBI组再按致伤后时间长短分为6 h、12 h、24 h、72 h、15 d五个亚组。TBI组应用PinPointTM颅脑撞击器撞击而致伤,sham组不撞击。采用Morris水迷宫评价实验动物空间记忆能力;干湿重法测定脑含水量,评估脑水肿与海马水通道蛋白4(aquaporin-4,AQP-4)的相关性;海马神经元特异性核蛋白(neuron specific nuclear protein,NeuN)标记和免疫荧光检测评估TBI致大鼠神经元丢失情况;通过Western印迹检测TBI致海马骨架相关蛋白质和记忆相关蛋白质含量变化。本研究证实,与sham组相比,TBI组大鼠潜伏期明显增加[(61.98±12.82) s vs.(28.32±8.52) s,n=5,P<0.01,day 15],探索时间明显缩短[(36.98±0.37) s vs. (73.68±5.09) s,n=5,P<0.01,day15],表明脑创伤损害了动物的空间参考记忆能力和空间工作记忆能力。与sham组相比,TBI组大鼠海马AQP-4在蛋白质水平上的表达和脑含水量持续升高,15 d恢复正常;在12 h[(3.78±0.74),(83.78±0.35)%]和72 h[(3.49±0.85),(82.28±0.63)%]均形成两个波峰,n=5,P均<0.01,表明继发性脑损伤与持续脑水肿和海马AQP-4在蛋白质上的高表达有关。与sham组相比,NeuN标记和免疫荧光检测发现,TBI后24 h 致大鼠海马神经元丢失严重[(198.2±8.002) vs.(297.2±6.866) cells/mm2, n=5,P<0.01],表明TBI动物的海马功能受损。与sham相比,TBI组海马神经元树突标志物微管结合蛋白2(microtubule associated proein 2,MAP2)和突触前终末特异性标记物突触素(synaptophysin,SYN)在蛋白质水平均伤后逐步降低(n=5,P均<0.01),72 h[(0.55±0.05) vs.(1.27±0.08), (0.52±0.14) vs.(1.06±0.16), n=5,P均<0.01]降低最明显;TBI组形成神经元纤维缠结主要成分的过度磷酸化tau(ser404),伤后逐步升高,72 h[(1.25±0.11)vs. (0.33±0.07), n=5,P<0.01]升高最明显。 MAP2、SYN和过度磷酸化的tau(ser404)检测指标的改变,表明脑损伤致神经元受损,神经元生长和损伤修复能力减弱,最终导致神经元骨架破环,TBI损害了动物的海马空间记忆能力。与sham组相比,TBI组大鼠海马环磷酸腺苷反应元件结合蛋白(cAMP response element binding protein,CREB)和磷酸化CREB ser133(phosphorylated CREB Ser133, pCREB Ser133)含量降低明显(n=5,P均<0.05),表明脑损伤动物海马的存储记忆能力减弱;TBI组大鼠海马一般调控阻遏蛋白激酶2(general control nonderepressible 2 kinase,GCN2)蛋白质升高明显(n=5,P均<0.05),表明脑损伤动物海马将新信息转化成长期记忆能力下降。本研究提示,创伤性脑损伤可使大鼠海马神经元骨架破坏,进而导致在学习记忆过程中起重要作用的分子蛋白质下调,抑制记忆储存的蛋白质(GCN2)上调,促使学习记忆功能障碍。  相似文献   

18.
Nogo-B在血管损伤、组织修复和炎症反应中发挥重要作用。然而,Nogo-B在动脉粥样硬化中的作用仍不明确。本研究拟在巨噬细胞中探讨Nogo-B对巨噬细胞泡沫化的影响。在RAW264.7细胞中沉默Nogo-B后,采用氧化低密度脂蛋白(Ox-LDL)或DiI修饰的Ox-LDL诱导巨噬细胞泡沫化;通过激光共聚焦显微镜观察巨噬细胞中荧光脂质,并在透射电镜下观察各组细胞中自噬泡;采用Western 印迹分析Plin2、p62和LC3-II的蛋白质水平;采用实时荧光定量PCR检测p62 mRNA水平;采用氯喹处理以及mRFP-GFP-LC3双荧光体系分析自噬流功能;进一步过表达Nogo-B后,比较巨噬细胞中脂质负荷程度以及Plin2、p62和LC3-II的蛋白质水平。结果显示,DiI-Ox-LDL处理后,Nogo-B沉默组细胞中脂质负荷程度高于对照组(2.34±0.67 vs. 0.69±0.14,P<0.05);Ox-LDL处理后,Nogo-B沉默组细胞中自噬泡数量(8.67±0.58 vs. 4.33±0.58,P<0.01)、Plin2(4.65±0.50 vs. 3.24±0.71,P<0.05)、p62(10.13±1.79 vs. 5.76±1.84,P<0.05)和LC3-II(4.38±0.20 vs. 2-33±1.56,P<0.01)的蛋白质水平均显著高于对照组,而p62 mRNA水平无差异(P>0.05);进一步研究发现,Nogo-B沉默组的自噬流被抑制了;过表达Nogo-B后,虽然p62蛋白质水平无明显变化,但是细胞中脂质负荷程度显著低于对照组(1.68±1.06 vs. 4.94±0.70,P<0.05),Plin2和LC3-II的蛋白质水平也明显降低。上述结果表明,Nogo-B通过促进自噬流抑制了Ox-LDL诱导的巨噬细胞泡沫化,Nogo-B可能具有抗动脉粥样硬化的作用。  相似文献   

19.
The effect of immunization against male accessory gland (MAG) homogenates over androgenic cytosolic and nuclear receptors of rat prostate was studied. In the MAG-immunized rats the Bmax of cytosolic receptors was significantly increased (120.3 +/- 44.3 vs 47.7 +/- 24.9 fmol/mg protein, p less than 0.01, mean +/- SD). In contrast, the Bmax of nuclear receptors in the MAG-immunized rats showed no significant difference as regarded controls (kidney immunized rats) when expressed as fmol/100 micrograms DNA (196.1 +/- 84.8 vs 148.3 +/- 88.9) but it show to slight differences (p less than 0.1) when data were reported as percent of weight of tissue (2,189 +/- 918.6 vs 1,303 +/- 611.2 fmol/g wet issue). Results (mean +/- SD) on binding affinity of cytosolic receptors showed no significant differences in MAG-immunized rats as compared with controls (Kd: 1.98 +/- 0.66 vs 1.92 +/- 0.20 nM). Likewise, only a slight difference between both groups was attained for Kds of nuclear receptors (2.34 +/- 0.28 vs 1.80 +/- 0.62 nM, p less than 0.2). On the other hand, 5 alpha 1-dihydrotestosterone (DHT) values obtained in prostate homogenates were significantly decreased in MAG-immunized rats as compared with controls (17.4 +/- 2.0 vs 7.1 +/- 0.9 ng/g tissue, mean +/- SD, p less than 0.01). However, testosterone (T) levels in gland tissue showed no significant differences between both groups (2.4 +/- 0.5 vs 2.6 +/- 0.3 ng/g tissue) with an increase in the T: DHT ratio from 0.14 to 0.37.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

20.
目的探究miR-142-3p靶向卵泡抑素样蛋白1(FSTL1)对结直肠癌(CRC)细胞增殖、凋亡以及放疗敏感性的影响。 方法培养正常人结肠细胞FHC与CRC细胞系SW480、DLD-1、HCT116和Caco-2,qRT-PCR检测细胞中miR-142-3P水平,Western Blot检测FSTL1蛋白水平;分别转染miR-142-3p模拟物(miR-142-3p组)、模拟物阴性对照(miR-NC组)、FSTL1的si-RNA9(si-FSTL1组)、si-RNA阴性对照(si-con组)至CRCSW480细胞,MTT检测细胞增殖情况,流式细胞仪检测细胞凋亡水平,Western Blot检测增殖、凋亡相关蛋白水平,克隆形成实验检测放射敏感性;双荧光素酶报告基因、Western Blot验证miR-142-3p与FSTL1关系及在CRC中作用。采用t检验和方差分析进行统计学分析。 结果CRC细胞SW480、DLD-?1、HCT116、Caco-2中miR-142-3p水平(0.86±0.09、1.09±0.11、0.76±0.08、0.98±0.10)低于正常结肠细胞FHC (2.56±0.26),差异具有统计学意义(t?= 18.536,15.621,19.851,17.016,P均< 0.01),FSTL1 mRNA水平2.26±0.23、1.39±0.14、2.01±0.20、1.98±0.19高于FHC细胞(0.79±0.08),差异具有统计学意义(t?= 18.110,11.163,16.991,17.317,P均?< 0.01),FSTL1蛋白水平(1.16±0.12、1.09±0.11、0.96±0.09、0.95±0.10)高于FHC细胞(0.37±0.04),差异有统计学意义(t?= 18.736,18.454,17.972,16.155,P均?< 0.01);miR-?142-?3p组CRC细胞SW480凋亡率(30.23±3.10)和Bax水平(1.02±0.11)高于miR-?con?组8.96±0.89,0.45±0.05,t?= 19.785,14.152,P均< 0.01,72?h细胞增殖活力(1.16±0.11)、CyclinD1 (0.35±0.05)、Bcl-2 (0.38±0.04)、8?Gy (7.56±0.75)细胞存活率低于miR-con组(1.60±0.16,1.02±0.12,0.98±0.10,10.35±1.25,t?= 6.798,15.462,16.713,5.742,P均< 0.01);si-FSTL1组SW480细胞72?h的细胞增殖活力(1.05±0.11)、CyclinD1(0.40±0.05)、Bcl-2(0.42±0.05)低于si-?con组(1.60±0.16,1.05±0.10,1.00±0.12,t?= 8.498,17.441,13.385,P均< 0.01),Bax(1.00±0.11)高于si-con组(0.41±0.04,t?= 15.122,P?< 0.01);miR-?142-3p负调控FSTL1表达,过表达FSTL1逆转了miR-142-3p过表达SW480细胞增殖、凋亡及放射敏感性的影响。 结论过表达miR-142-3p可能通过下调FSTL1表达抑制CRC细胞增殖,诱导其凋亡,并增强其放疗敏感性。  相似文献   

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