冠心病患者外周血核转录因子PPARγ和MMP-9表达的临床研究

目的探讨血核转录因子PPARγmRNA表达与血浆基质金属蛋白酶-9（MMP-9）水平和冠脉病变的关系。方法对确诊为冠心病患者153例，采用RT-PCR法测定外周血中PPARγmRNA表达，ELISA法检测血浆中MMP-9含量，分析冠脉病变程度与PPAR3，mRNA表达、MMP-9水平与冠脉病变程度的相关性。结果CHD组PPARγ比对照组明显降低，MMP-9比对照组明显增加。CHD组中ACS组PPA脚比SAP组明显降低，MMP-9比SAP组明显增加，PPARγmRNA表达与冠脉病变支数、病变类型呈负相关（P〈0．05），MMPO水平与病变支数、病变类型呈正相关（P〈0．05）。PPARγmRNA表达和MMP-9水平呈明显负相关关系。结论MMP-9时ACS不稳定斑块有促进作者，PPARγ具有抑制MMP-9的作用，提示通过激活PPARγmRNA表达和降低MMP-9水平时冠心病高危人群具有保护作用。     

ADFMCHR激活PPARγ抑制人肝癌SMMC-7721细胞生长

目的:研究5-烯丙基-7-二氟亚甲基白杨素(ADFMChR)激活过氧化物酶活化因子受体γ(PPARγ)抑制体外培养人肝癌SMMC-7721细胞增殖作用。方法:体外培养人肝癌SMMC-7721细胞。台盼蓝拒染法检测细胞生长;平皿克隆形成法检测细胞锚定依赖性生长;软琼脂克隆形成法检测细胞集落形成能力。结果:细胞计数结果显示,ADFMChR延长SMMC-7721细胞倍增时间,抑制SMMC-7721细胞生长,呈剂量依赖性。但是对预先用PPARγ阻断剂GW 9662孵育30分钟的SMMC-7721细胞,ADFMChR的生长抑制作用明显降低;平皿克隆、软琼脂克隆形成法结果显示,ADFMChR抑制SMMC-7721细胞的锚定依赖性生长能力和锚定非依赖性生长能力,而GW 9662可以降低ADFMChR对SMMC-7721细胞的增值抑制作用。结论:ADFMChR具有抑制人肝癌SMMC-7721细胞生长作用,其机制与激活PPARγ有关。     

TACE术联合体部伽玛刀序贯治疗中晚期肝癌临床研究

目的：研究肝动脉化疗栓塞（TACE）术联合体部伽马刀治疗原发性肝癌（PHC）的疗效。方法：对已确诊的中晚期原发性肝癌106例分为A、B、c三组，行TACE治疗组（A组）36例，行TACE1—3次，单纯伽马刀治疗组（B组）38例，TACE联合伽马刀序贯治疗组32例（c组）。结果：单纯肝动脉化疗栓塞36例共序贯治疗68次，TACE术联合伽马刀序贯治疗组32例（C组）中32次放射＋介入治疗39次。单纯行TACE治疗组完全缓解率CR2．6％，部分缓解率PR44％，CR＋PR46．6％；单纯伽马刀治疗组38例，完全缓解率CR3．8％，部分缓解率PR53．6％，CR＋PR57．4％，TACE术联合伽马刀序贯治疗组共32例，完全缓解率CR7．6％，部分缓解率PR52％，CR＋PR59．6％。结论：行肝动脉化疗栓塞（TACE术）联合体部伽马刀对不能手术的原发性肝癌进行治疗是目前疗效较好的局部治疗方式，并不增加不良反应，可使肿瘤局部得到准确的高剂量照射，又避免了周围正常组织的损伤，副作用少而轻微。     

罗格列酮对MGC803细胞小鼠肾囊膜下移植瘤生长的影响

目的 探讨过氧化酶体增生物激活受体γ(PPARγ)配体罗格列酮对小鼠体内人类胃癌MGC803细胞移植瘤生长的影响.方法 建立人类胃癌MGC803细胞小鼠肾囊膜下移植瘤模型,通过解剖显微镜和HE染色观察50 mg/kg的罗格列酮连续灌胃5 d作用于荷瘤小鼠后对移植瘤生长的抑制作用.结果 50 mg/kg的罗格列酮能明显抑N4,鼠肾囊膜下移植瘤MGC803细胞增生、诱导肿瘤细胞凋亡而抑制移植瘤的生长,抑瘤率达62.9%.结论 PPARγ配体罗格列酮能抑制小鼠体内肾囊膜下MGC803细胞移植瘤生长.     

PPAR-γ配体抗前列腺癌作用研究现状及展望

前列腺癌是男性生殖系统常见的恶性肿瘤。激素依赖性前列腺癌的治疗主要采用内分泌治疗,而激素非依赖性前列腺癌在目前尚缺乏有效的治疗方法。近年来,有研究发现过氧化物酶体增殖物激活受体γ(PPAR-γ)与前列腺癌关系密切,PPAR-γ活化后具有抗前列腺癌作用,有望成为预防、治疗前列腺癌的新位点。本文就其配体在抗前列腺癌作用方面的研究作一综述。     

Modulation of dendritic release of dopamine by metabotropic glutamate receptors in rat substantia nigra

A superfusion system was used to study the effects of metabotropic glutamate receptor (mGluR) ligands upon the release of [(3)H]dopamine ([(3)H]DA) previously taken up by rat substantia nigra (SN) slices. trans-(+/-)-1-Amino-(1S,3R)-cyclopentane dicarboxylic acid (trans-ACPD; 100 and 600 microM), a group I and II mGluR agonist, evoked the release of [(3)H]DA from nigral slices. This last effect was reduced significantly by (2S,3S,4S)-2-methyl-2-(carboxycyclopropyl)-glycine (MCCG; 300 microM), an antagonist of group II mGluR, or by the addition of tetrodotoxin (D-APV; 1 microM) to the superfusion medium. D-(-)-2-Amino-5-phosphono-valeric acid (100 microM), an N-methyl-D-aspartate receptor antagonist, or the presence of Mg(2+) (1.2mM) in the superfusion medium did not modify trans-ACPD-induced [(3)H]DA release. In addition, a group II mGluR agonist such as (2S,1'R,2'R,3'R)-2-(2',3'-dicarboxycyclopropyl)-glycine (DCG-IV; 100 microM) significantly induced the release of [(3)H]DA from nigral slices, whereas a group I mGluR agonist such as (RS)-3,5-dihydroxyphenylglycine (DHPG; 50 and 100 microM) did not modify the release of the [(3)H]-amine. Further experiments showed that the NMDA (100 microM)-evoked release of [(3)H]DA was decreased significantly by prior exposure of SN slices to trans-ACPD. Finally, partial denervation of the DA nigro-striatal pathway with 6-hydroxydopamine (6-OH-DA) increased trans-ACPD-induced release of [(3)H]DA, whereas it decreased trans-ACPD inhibitory effects on NMDA-evoked release of [(3)H]DA from nigral slices. The present results suggest that the dendritic release of DA in the SN is regulated by mGluR activation. Such nigral mGluR activation may produce opposite effects upon basal and NMDA-evoked release of DA in the SN. In addition, such mGluR-induced effects in the SN are modified in response to partial denervation of the DA nigro-striatal pathway.     

Anxiolytic effect of wogonin,a benzodiazepine receptor ligand isolated from Scutellaria baicalensis Georgi

The search for novel anxiolytics devoid of undesirable side-effects typical of classical benzodiazepines (BDZs) has been intense, and flavonoids, as a relative new class of ligands, have been shown to possess anxiolytic effects in vivo. The present study evaluated the pharmacological properties of a naturally occurring monoflavonoid, 5,7-dihydroxy-8-methoxyflavone or wogonin. The affinity (K(i)) of wogonin for the benzodiazepine site (BZD-S) on the gamma-aminobutyric acid(A) (GABA(A)) receptor complex was 0.92 microM. Using electrophysiological techniques, we showed that wogonin enhanced the GABA-activated current in rat dorsal root ganglion neurons, and in Xenopus laevis oocytes expressing recombinant rat GABA(A) receptors, the enhancement was partially reversed by the co-application of a 1 microM concentration of the BZD-S antagonist anexate (Ro15-1788). Acute toxicity and behavioral effects were examined in mice. Acute lethal activity was low, with an LD(50) of 3.9 g/kg. Oral administration of wogonin (7.5 to 30 mg/kg) elicited an anxiolytic response that was similar to that elicited by diazepam in the elevated plus-maze; a dose-dependent increase in open arm entries and time spent in open arms was observed. More importantly, its anxiolytic effect was blocked by the co-administration of Ro15-1788. In the holeboard test, not only did wogonin-treated mice experience an increased number of head-dips but they also spent more time at it, showing no signs of sedation. Furthermore, wogonin did not cause myorelaxant effects in the horizontal wire test. Taken together, these data suggest that wogonin exerts its anxiolytic effect through positive allosteric modulation of the GABA(A) receptor complex via interaction at the BZD-S. Its anxiolytic effect was not accompanied by sedative and myorelaxant side-effects typical of BDZs.     

Involvement of the peroxisome proliferator-activated receptor alpha in the immunomodulation caused by peroxisome proliferators in mice

Peroxisome proliferators (PPs) are a large class of structurally diverse chemicals, which includes drugs designed to improve the metabolic abnormalities linking hypertriglyceridemia to diabetes, hyperglycemia, insulin-resistance and atherosclerosis. We have recently demonstrated that exposure of rodents to potent PPs indirectly causes a number of immunomodulating effects, resulting in severe adaptive immunosuppression. Since the peroxisome proliferator-activated receptor alpha (PPARalpha) plays a central role in mediating the pleiotropic responses exerted by PPs, we have compared here the immunomodulating effects of the PPs perfluorooctanoic acid (PFOA) and Wy-14,643 in wild-type and PPARalpha-null mice. The reductions in spleen weight and in the number of splenocytes caused by PP treatment in wild-type mice was not observed in PPARalpha-null mice. Furthermore, the reductions in thymus weight and in the number of thymocytes were potently attenuated in the latter animals. Similarly, the dramatic decreases in the size of the CD4(+)CD8(+) population of cells in the thymus and in the number of thymocytes in the S and G2/M phases of the cell cycle observed in wild-type mice administered PPs were much less extensive in PPARalpha-null mice. Finally, in contrast to the case of wild-type animals, the response of splenocytes isolated from the spleen of PP-treated PPARalpha-null mice to appropriate T- or B-cell activators in vitro was not reduced. Altogether, these data indicate that PPARalpha plays a major role in the immunomodulation caused by PPs. The possible relevance of these changes to the alterations in plasma lipids also caused by PPs is discussed.     

Autoschizis: a novel cell death

Vitamin C (VC) and vitamin K(3) (VK(3)) administered in a VC:VK(3) ratio of 100:1 exhibit synergistic antitumor activity and preferentially kill tumor cells by autoschizis, a novel type of necrosis characterized by exaggerated membrane damage and progressive loss of organelle-free cytoplasm through a series of self-excisions. During this process, the nucleus becomes smaller, cell size decreases one-half to one-third of its original size, and most organelles surround an intact nucleus in a narrow rim of cytoplasm. While the mitochondria are condensed, tumor cell death does not result from ATP depletion. However, vitamin treatment induces a G(1)/S block, diminishes DNA synthesis, increases H(2)O(2) production, and decreases cellular thiol levels. These effects can be prevented by the addition of catalase to scavenge the H(2)O(2). There is a concurrent 8- to 10-fold increase in intracellular Ca(2+) levels. Electrophoretic analysis of DNA reveals degradation due to the caspase-3-independent reactivation of deoxyribonuclease I and II (DNase I, DNase II). Redox cycling of the vitamins is believed to increase oxidative stress until it surpasses the reducing ability of cellular thiols and induces Ca(2+) release, which triggers activation of Ca(2+)-dependent DNase and leads to degradation of DNA. Recent experiments indicate that oral VC:VK(3) increases the life-span of tumor-bearing nude mice and significantly reduces the growth rate of solid tumors without any significant toxicity by reactivating DNase I and II and inducing autoschizis. This report discusses the mechanisms of action employed by these vitamins to induce tumor-specific death by autoschizis.     

Cellular energetics and glutathione status in NRK-52E cells: toxicological implications

Cellular energetics and redox status were evaluated in NRK-52E cells, a stable cell line derived from rat proximal tubules. To assess toxicological implications of these properties, susceptibility to apoptosis induced by S-(1,2-dichlorovinyl)-L-cysteine (DCVC), a well-known mitochondrial and renal cytotoxicant, was studied. Cells exhibited high activities of several glutathione (GSH)-dependent enzymes, including gamma-glutamylcysteine synthetase, GSH peroxidase, glutathione disulfide reductase, and GSH S-transferase, but very low activities of gamma-glutamyltransferase and alkaline phosphatase, consistent with a low content of brush-border microvilli. Uptake and total cellular accumulation of [14C]alpha-methylglucose was significantly higher when cells were exposed at the basolateral as compared to the brush-border membrane. Similarly, uptake of GSH was nearly 2-fold higher across the basolateral than the brush-border membrane. High activities of (Na(+)+K(+))-ATPase and malic dehydrogenase, but low activities of other mitochondrial enzymes, respiration, and transport of GSH and dicarboxylates into mitochondria were observed. Examination of mitochondrial density by confocal microscopy, using a fluorescent marker (MitoTracker Orange), indicated that NRK-52E cells contain a much lower content of mitochondria than rat renal proximal tubules in vivo. Incubation of cells with DCVC caused time- and concentration-dependent ATP depletion that was largely dependent on transport and bioactivation, as observed in the rat, on induction of apoptosis, and on morphological damage. Comparison with primary cultures of rat and human proximal tubular cells suggests that the NRK-52E cells are modestly less sensitive to DCVC. In most respects, however, NRK-52E cells exhibited functions similar to those of the rat renal proximal tubule in vivo.