过氧化氢酶过度表达对血管平滑肌细胞凋亡的影响

目的 探讨腺病毒戢体介导的过氧化氢酶基因转染对体外培养的人血管平滑肌细胞凋亡的影响。方法 用含过氧化氢酶基因的重组腺病毒转染人血管平滑肌细胞，采用Western blot方法检测血管平滑肌细胞过氧化氢酶的表达。应用流式细胞术、TUNEL法等方法检测血管平滑肌细胞的凋亡。结果 含过氧化氢酶基因的重组腺病毒转染后血管平滑肌细胞过氧化氢酶表达明显增多；流式细胞术显示含过氧化氢酶基因的重组腺病毒组与对照组比较凋亡率明显增加（P〈0．01）。经TUNEL分析显示，含过氧化氢酶基因的重组腺病毒组凋亡细胞明显多于对照组。两者之间有显著性差异（P〈0．001）。结论 腺病毒载体介导的过氧化氢酶基因转染导致过氧化氢酶过度表达。促进人血管平滑肌细胞的凋亡，这可能是防治经皮腔内冠状动脉血管成形术后再狭窄的一种新方法。     

TFPI基因转染对血管平滑肌细胞中细胞凋亡抑制蛋白的调控

目的研究组织因子途径抑制物(TFPI)基因转染对大鼠血管平滑肌细胞中细胞凋亡抑制蛋白(IAP)表达的影响,探讨TFPI诱导细胞凋亡的可能机制。方法将含有人TFPI基因的重组腺病毒或含β-半乳糖苷酶(LacZ)基因的重组腺病毒或DMEM在体外分别转染大鼠血管平滑肌细胞,用ELISA方法测定转染后细胞中TFPI蛋白的表达水平,用RT-PCR方法测定基因转染后不同时间点细胞中c-IAP1mRNA的表达,用Western-blot方法检测基因转染后不同时间点细胞中survivin的表达。结果基因转染后1天在血管平滑肌细胞中即可检测到TFPI蛋白表达,峰值出现在转染后第3天;基因转染后3天和7天,TFPI组c-IAP1 mRNA的表达与对照组相比明显减少(P0.05);基因转染后3、5、7天,TFPI组survivin的表达与对照组相比明显减少(P0.05),且具有明显的时间依赖性。结论 TFPI可能通过抑制IAP的表达来发挥诱导平滑肌细胞凋亡的作用,从而抑制冠状动脉介入治疗后再狭窄发生。     

重组腺病毒AdCat对血管平滑肌细胞

目的探讨腺病毒载体介导的过氧化氢酶基因转染对体外培养的人血管平滑肌细胞增殖与凋亡的影响.方法用含过氧化氢酶基因的重组腺病毒(AdCat)转染人血管平滑肌细胞,采用Western blot 方法检测血管平滑肌细胞过氧化氢酶的表达,应用细胞计数方法观察血管平滑肌细胞的增殖活性,应用流式细胞术和Hoechst 33258 染色等方法对血管平滑肌细胞的凋亡进行研究.结果Western blot显示AdCat转染后血管平滑肌细胞过氧化氢酶表达明显增多;细胞计数显示AdCat组明显抑制细胞增殖,与阴性对照组、空白对照组相比差异有统计学意义(P<0.01);流式细胞术显示AdCat组与阴性对照组、空白对照组比较凋亡率明显增加(P<0.01).经Hoechst 33258染色后,AdCat组凋亡细胞明显多于空白对照组.结论重组腺病毒AdCat转染导致血管平滑肌细胞过氧化氢酶过度表达,抑制血管平滑肌细胞的增殖,促进血管平滑肌细胞的凋亡.     

线粒体融合素基因2突变体Mfn2-1A抑制大鼠血管平滑肌细胞增殖及机制研究

目的:研究线粒体融合素基因2(Mfn2)的突变体片段Mfn2-1A,对自发性高血压大鼠血管平滑肌细胞的增殖抑制作用,并进一步探讨相关作用机制。方法:用已构建的重组腺病毒Adv-Mfn2-1A感染大鼠血管平滑肌细胞,利用细胞计数、四甲基偶氮唑盐比色法检测血管平滑肌细胞增殖,流式细胞仪检测细胞生长周期,蛋白免疫印迹法分析Mfn2-1A对信号通路Mek-Erk1/2蛋白表达水平的影响。结果:重组腺病毒Adv-Mfn2-1A感染平滑肌细胞能正常表达相应蛋白;转染Adv-Mfn2-1A后能抑制平滑肌细胞增殖(P<0.05),第3天开始效果明显;Adv-Mfn2-1A较Adv-Mfn2作用效果更显著(P<0.05);转染Adv-Mfn2-1A和Adv-Mfn2后阻滞于G0/G1期的细胞明显增多,转染Mfn2-1A后阻滞在G0/G1期细胞达到(77.74±3.67)%;Mfn2-1A可降低平滑肌细胞中磷酸化Erk1/2蛋白的表达,效果比Mfn2更明显(P<0.05)。结论:Mfn2基因突变体片段1A可明显抑制血管平滑肌增殖,使细胞阻滞在G0/G1期,其机制与抑制Mek-Erk1/2信号通路有关。     

大鼠ANT1基因腺病毒载体的构建及体外表达

目的 构建大鼠线粒体蛋白ANT1基因的腺病毒载体,并检测其在体外培养的血管平滑肌细胞(VSMCs)中的表达.方法 将大鼠线粒体膜蛋白腺(嘌呤核)苷酸移位酶(adenine nucleotide translocase,ANT)1基因片段克隆至穿梭质粒pShuttle-GFP-CMV上,在细菌中将穿梭质粒和pAdXsi载体进行重组,经脂质体转染HEK293细胞对重组腺病毒包装、扩增,用其感染体外培养的VSMC.采用PCR方法对重组体腺病毒进行鉴定,荧光显微镜观察转染效率.用Western印迹检测转染后ANT1在VSMC中的表达.结果 酶切鉴定及PCR结果表明ANT1基因重组腺病毒载体构建成功,病毒滴度达2×1011 pfu/ml,Western印迹检测ANT1在VSMC中表达明显高于对照组(P<0.05).结论 成功构建了含大鼠ANT1基因的重组腺病毒载体并在VSMCs有效表达,为以后将Ad-ANT1应用于VSMCs凋亡的研究奠定了基础.     

去除蛋白激酶A磷酸化位点的线粒体融合素2基因对血管平滑肌细胞凋亡的影响

目的 研究大鼠线粒体融合素2基因在去除蛋白激酶A磷酸化位点后对大鼠血管平滑肌细胞凋亡的影响及其相关的信号通路.方法 利用携带去除蛋白激酶A磷酸化位点的线粒体融合素2基因重组腺病毒(AdvMfn2-PKA(△))和携带线粒体融合素2基因的重组腺病毒(Adv-Mfn2),感染培养的大鼠血管平滑肌细胞.免疫印迹分析相关蛋白的表达;激光共聚焦显微镜观察其亚细胞定位;细胞凋亡酶联免疫吸附法比较其对细胞凋亡的影响;免疫印迹法分析磷酸化蛋白激酶B蛋白表达变化.结果 外源基因转染后可表达特异性蛋白产物;激光共聚焦显微镜显示去除蛋白激酶A磷酸化位点后的线粒体融合素2基因表达产物主要分布于线粒体外膜;酶联免疫吸附法检测显示去除蛋白激酶A磷酸化位点后,线粒体融合素2基因诱导大鼠血管平滑肌细胞凋亡作用显著减弱(P＜0.01),与空白对照组差异无显著性;免疫印迹检测表明Mfn2-PKA(△)组磷酸化蛋白激酶B表达较Mfn2组显著升高(P＜0.01),与空白对照组差异无显著性.结论 去除蛋白激酶A磷酸化位点的线粒体融合素2基因表达产物仍主要分布于线粒体外膜,但其诱导血管平滑肌细胞凋亡的作用丧失,对蛋白激酶B信号通路也无抑制作用.这表明蛋白激酶A磷酸化位点是调控线粒体融合素2基因诱导血管平滑肌细胞凋亡的重要功能位点.     

富含半胱氨酸蛋白61RNA干扰质粒抑制血管平滑肌细胞的增殖

目的 观察富含半胱氨酸蛋白61(Cyr61)RNA干扰质粒(pCyr61-shRNA)对大鼠血管平滑肌细胞增殖的影响.方法 构建Cyr61 RNA干扰质粒转染大鼠血管平滑肌细胞,采用半定量逆转录聚合酶链反应及Western blot检测Cyr61 RNA和蛋白表达;采用MTT法检测细胞增殖;3H-标记胸腺嘧啶掺入法检测细胞DNA含量.结果 测序证实成功构建Cyr61 RNA干扰质粒;转染pCyr61-shRNA组mRNA及蛋白表达均明显降低(P<0 01);pCyr61-shRNA组细胞数、吸光度值和DNA含量均明显降低(P<0 01).结论 Cyr61 RNA干扰质粒抑制大鼠血管平滑肌细胞的增殖.     

血管紧张素Ⅱ型受体基因转染表达对血管平滑肌细胞迁移的影响

目的 :探讨血管紧张素 （Ang ） 2型受体 （AT2 R）基因表达对血管平滑肌细胞 （VSMC）迁移能力的影响。方法 :构建带 AT2 R基因的重组复制缺陷腺病毒载体 （Ad CMV - AT2 R） ,体外转染培养的大鼠主动脉 VSMC,用流式细胞仪检测 AT2 R转染表达率 ,RT- PCR方法检测 AT2 R m RNA表达 ,VSMC迁移用改良 Boyden’s趋化小室法检测 ,用激光共聚焦显微镜检测细胞骨架蛋白 F- actin的表达。结果 :构建的 Ad CMV - AT2 R体外转染培养 VSMC表达率为 89.5 %。 AT2 R峰值表达时 ,VSMC的跨膜迁移数降低 6 2 .2 % ,F- actin表达明显减少。结论 :AT2 R转染表达可显著抑制体外培养 VSMC迁移 ,这为防治血管再狭窄提供了新的思路。     

野生型P53基因导入诱导血管平滑肌细胞凋亡

为观察野生型P53基因诱导血管平滑肌细胞凋亡的现象，探讨对生型P53基因导入抑制平滑肌细胞增殖的作用机理，构建了野生型P53基因的重组腺病毒载体，体外转染兔主动脉血管平滑肌细胞。应用流式细胞议分析细胞周期，氚标胸腺嘧啶脱氧核苷掺入试验检测DNA合成，琼脂糖凝胶电泳观察DNA区带图谱，末端脱氧核苷酸转移酶介导的dUTP切口末端标记技术原位检测细胞凋亡。结果发现，野生型P53基因重组腺病毒载体转梁平滑肌细胞后，细胞内DNA合成减少。流式细胞仪分析显示77％的平滑肌细胞生长停滞在G0／Gl期，约45％的细胞发生细胞凋亡。dUTP切口末端标记阳性细胞百分率为40％～50％。DNA在琼脂糖凝胶电泳中呈现阶梯状区带图谱。以上结果提示，野生型P53基因通过诱导细胞凋亡对血管平滑肌细胞增殖起抑制作用。     

IGF-1重组腺病毒转染对缺氧诱导的神经干细胞凋亡的影响

将人胰岛素样生长因子-1(IGF-1)重组腺病毒(Ad IGF-1)转染C17.2神经干细胞;Western blot法检测IGF-1 蛋白的表达;建立神经干细胞缺氧模型,TUNEL 法检测细胞凋亡指数,流式细胞术测定细胞凋亡率的变化.发现转染Ad IGF-1的C17.2神经干细胞成功表达IGF-1 蛋白;缺氧诱导C17.2神经干细胞凋亡,转染Ad IGF-1的C17.2神经干细胞凋亡指数、凋亡率与对照组相比有显著差异.提示转染Ad IGF-1能减轻缺氧诱导的C17.2神经干细胞凋亡.     

Three layer functional model and energy exchange concept of aging process

Relying on a certain degree of abstraction, we can propose that no particular distinction exists between animate or living matter and inanimate matter. While focusing attention on some specifics, the dividing line between the two can be drawn. The most apparent distinction is in the level of structural and functional organization with the dissimilar streams of ‘energy flow’ between the observed entity and the surrounding environment. In essence, living matter is created from inanimate matter which is organized to contain internal intense energy processes and maintain lower intensity energy exchange processes with the environment. Taking internal and external energy processes into account, we contend in this paper that living matter can be referred to as matter of dissipative structure, with this structure assumed to be a common quality of all living creatures and living matter in general. Interruption of internal energy conversion processes and terminating the controlled energy exchange with the environment leads to degeneration of dissipative structure and reduction of the same to inanimate matter, (gas, liquid and/or solid inanimate substances), and ultimately what can be called ‘death.’ This concept of what we call dissipative nature can be extended from living organisms to social groups of animals, to mankind. An analogy based on the organization of matter provides a basis for a functional model of living entities. The models relies on the parallels among the three central structures of any cell (nucleus, cytoplasm and outer membrane) and the human body (central organs, body fluids along with the connective tissues, and external skin integument). This three-part structural organization may be observed almost universally in nature. It can be observed from the atomic structure to the planetary and intergalactic organizations. This similarity is corroborated by the membrane theory applied to living organisms. According to the energy nature of living matter and the proposed functional model, the decreased integrity of a human body's external envelope membrane is a first cause of the structural degradation and aging of the entire organism. The aging process than progresses externally to internally, as in single cell organisms, suggesting that much of the efforts towards the restoration and maintenance of the mechanisms responsible for structural development should be focused accordingly, on the membrane, i.e., the skin. Numerous reports indicate that all parts of the human body, like: bones, blood with blood vessels, muscles, skin, and so on, have some ability for restoration. Therefore, actual revival of not only aging tissue of the human body's membrane, but the entire human body enclosed within, with all internal organs, might be expected. We assess several aging theories within the context of our model and provide suggestions on how to activate the body's own anti-aging mechanisms and increase longevity. This paper presents some analogies and some distinctions that exist between the living dissipative structure matter and inanimate matter, discusses the aging process and proposes certain aging reversal solutions.     

Unusual responses of nocturnal pineal melatonin synthesis and secretion to swimming: Attempts to define mechanisms

Abstract: The effect of swimming at night on rat pineal melatonin synthesis was compared with that of light exposure at night. Rats were forced to swim at 0030 hr (lights out at 2000 hr) and sacrificed by decapitation 15 and 30 min later, immediately after swimming. Other groups of animals were exposed to white light (650μW/cm²) for 15 and 30 min at same time. Swimming caused a rapid and highly significant drop in the melatonin content in the pineal gland; however, the activity of N-acetyltransferase (NAT), the supposed rate limiting enzyme in the melatonin production, was not changed. Despite the drop in pineal melatonin levels, serum concentrations of the indole remained elevated in the rats that swam. In contrast, melatonin levels in the pineal and serum of light exposed rats fell precipitously, accompanied by a significant suppression of NAT activity. Since we anticipated that the strenuous exercise associated with swimming may induce release of artrial natriuretic peptide (ANP) from the heart, which in turn could cause the release of pineal melatonin, in a second study we injected physiological saline intravenously to stretch the cardiac muscle and release ANP. Three milliliters of normal saline was injected during the day into the jugular vein of anesthetized rats that were pretreated with isoproterenol to stimulate pineal melatonin production. Animals were killed 15 min after the saline injection, and pineal NAT activity and pineal melatonin levels were measured. The saline injections caused no alteration in the elevated levels of either NAT or melatonin. These data suggest that the disparity in pineal NAT activity (which was high) and pineal melatonin (which was low), in animals swum at night, may not be caused by ANP which is released during strenuous exercise such as swimming.     

Melatonin and photoperiodic time measurement: Seasonal breeding in the sheep

Abstract: Well-established circadian physiology supports the view that photoperiodic time measurement utilizes the coincidence between the presence of light and a photosensitive phase of a 'biological clock' to alter reproductive status—the so-called external coincidence model of seasonal breeding. In this review, we examine the mechanism whereby photoperiod interacts with presumed suprachiasmatic nuclei activity to allow endogenous melatonin to normally synchronize reproductive activity to the optimal time of year. The Romney Marsh sheep is particularly explored as an experimental model. It is suggested that the on/off activity of seasonal reproduction may be a robust mechanism able to be predictably manipulated by the judicious use of the light/dark cycle and exogenous melatonin, but firmly based on circadian principles.     

Serological survey of HIV and syphilis in pregnant women in Madagascar

Objectives Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow‐up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Methods Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow‐up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Results Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Conclusions Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.     

Variabilité des concentrations plasmatiques de l’angiotensinogène et risque d’hypertension artérielle chez le rat transgénique

Aim

Genetic polymorphisms of the human angiotensinogen gene are frequent and may induce up to 30% increase of plasma angiotensinogen concentrations with a blood pressure increase of up to 5 mmHg. Their role for the pathogenesis of human arterial hypertension remains unclear. High plasma angiotensinogen levels could increase the sensitivity to other blood pressure stressors.

Methods

Male transgenic rats with a 9-fold increase of plasma angiotensinogen concentrations and male non-transgenic rats aged 10 weeks were treated or not with NG-Nitro-L-arginine-methyl ester for 3 weeks in their drinking water (n = 3/group). Systolic blood pressure and body weight were measured at baseline and at the end of the study when left ventricular weight and ventricular expression of angiotensin I-converting enzyme and procollagen Iα1 were determined (polymerase chain reaction).

Results

At baseline, transgenic rats had +18 mmHg higher bood pressure and –8% lower body weight compared to non-transgenic rats (P < 0.05) without significant changes for the vehicle groups throughout the study (P > 0.05). NG-Nitro-L-arginine-methyl ester increased blood pressure, left ventricular weight and left ventricular weight indexed for body weight by +41%, +17.6% and +18.6% (P < 0.05) in transgenic and +25%, +5.3% and +6.7% (P > 0.05) in non-transgenic rats compared to untreated animals, respectively. Cardiac gene expression showed no differences between groups (P > 0.05).

Conclusion

Increased plasma angiotensinogen levels may sensitize to additional blood pressure stressors. Our preliminary results point towards an independent role of angiotensinogen in the pathogenesis of human hypertension and associated end-organ damage.     

Morphological and immunocytochemical heterogeneity of cultured pinealocytes from one-week-and two-month-old rats: Planimetric and densitometric investigations

Abstract: In vitro preparations of rat pinealocytes are widely used for biochemical analyses of signal transduction processes. This paper deals with morphological and immunocytochemical features of such preparations. Special attention was paid to the problems of whether pinealocytes represent a heterogeneous cell population and how such heterogeneity may develop during ontogeny. The investigations were performed with cells which were obtained from the pineal organ of one-week-and two-month-old rats, attached to synthetic peptide-coated coverslips or tissue culture chamber slides, and maintained under in vitro conditions overnight. The attached cells were then fixed with paraformaldehyde. These preparations yielded monolayers of spherical cells of different sizes; most cells were isolated, but some of them were aggregated and formed small clusters. On the average, the cells from the one-week-old animals were smaller than the cells from the two-month-old animals. Immunocytochemical demonstration of S-antigen, a pinealocyte-specific marker, showed that the majority of the cells from two-month-old animals were intensely or moderately labelled. Pinealocytes from one-week-old animals were less S-antigen immunoreactive. Only very few cells (less than 1% displayed glial fibrillary acidic protein (GFAP)-immunoreactivity. Planimetric investigations of the cell size and semiquantitative densitometric investigations of the intensity of the S-antigen immunoreaction revealed that (i) pinealocytes kept in vitro form a heterogeneous cell population, and that (ii) this heterogeneity increases during postnatal development from one-week-old to two-month-old animals. Two groups of pinealocytes can be distinguished based on their developmental fate: pinealocytes of one group grow dramatically, but show only a moderate increase in S-antigen immunoreactivity, and pinealocytes of the other group retain their size, but display a distinct increment in S-antigen immunoreacti vitv.     

MUTATION FREQUENCY IN NURSES AND PHARMACISTS WORKING WITH CYTOTOXIC DRUGS

Individuals occupationally exposed to cytotoxic drugs may be at risk owing to the effects of these agents on DNA. As an index of DNA damage, in vivo mutations were measured in lymphocytes from 24 oncology nurses or pharmacists and 24 matched controls. Mutation frequency was significantly increased in exposed individuals and appeared to be related to duration of exposure. However, the overall magnitude of the increase was small and its biological significance remains to be determined.