大鼠免疫细胞的促肾上腺皮质激素受体的研究

大鼠免疫细胞都有高、低亲和力两类ＡＣＴＨ受体。脾脏细胞高亲和力促肾上腺皮质激素（ＡＣＴＨ）受体的解离常数（ＫＤ）为０．１１ｎｍｏｌ／Ｌ，最大结合量（Ｂｍａｘ）为１．２ｆｍｏｌ／２×１０￣６细胞，３６６位点／细胞，低亲和力受体ＫＤ为５．７ｎｍｏｌ／Ｌ，Ｂｍａｘ为１４７ｆｍｏｌ／２×１０￣６细胞，４２０００位点／细胞。外周血淋巴细胞（ＰＢＬ）高亲和力ＡＣＴＨ受体的ＫＤ值为０．１５ｎｍｏｌ／Ｌ，Ｂｍａｘ为１．２ｆｍｏｌ／１×１０￣６细胞，１５８０位点／细胞，低亲和力受体ＫＤ值为６．１ｎｍｏｌ／Ｌ，Ｂｍａｘ为３７．５ｆｍｏｌ／１×１０￣６细胞，３２０００位点／细胞。胸腺细胞、Ｔ、Ｂ淋巴细胞及腹腔巨噬细胞（Ｍφ）亦具有高、低亲和力不同的ＡＣＴＨ受体。     

用PCR技术研究缺氧时大鼠肺肾上腺素能β2受体及其mRNA的变化

本文观察常压缺氧性肺动脉高压大鼠肺组织β和β＿２受体以及β受体ｍＲＮＡ含量的变化。动物分对照组，缺氧２周及４周组。用放射性配基结合法测定β和β＿２受体，用反转录一聚合酶链反应（ＲＴ－ＰＣＲ）和液体闪烁计数测定β＿２受体ｍＲＮＡ的变化。结果表明，缺氧２及４周大鼠肺组织β受体从对照组的２２４．９±２３．７ｆｍｏｌ／ｍｇ蛋白分别下降到１４７．０±１９．４和１４２．７±３．１ｆｍｏｌ／ｍｇ蛋白，（均Ｐ＜０．００１）。β＿２受体从对照组的１７３．８±２１．４ｆｍｏｌ／ｍｇ蛋白分别降至６７，１±１１．８和３８．１±４．０ｆｍｏｌ／ｍｇ蛋白，（与对照比及缺氧组间比均Ｐ＜０．００１）。缺氧２周时β＿２受体ｍＲＮＡ水平与对照相比无变化，缺氧４周时明显下降（为对照的４２％，Ｐ＜０．００１）。缺氧４周β＿２受体下降可能与此有关。揭示缺氧后肺β＿２受体下降的分子生物学基础。对肺动脉高压发生发展机制提供新的认识。     

地塞米松对内毒素急性肺损伤磷脂酶A2活性变化的影响

实验采用绵羊慢性肺淋巴瘘－内毒素急性肺损伤模型，检测了肺组织磷脂酶Ａ２（ＰＬＡ２）活性及有关指标改变，并观察了地塞米松（Ｄｅｘ）对ＰＬＡ２活性变化的影响。结果发现，内毒素致伤后肺组织ＰＬＡ２活性及血栓素Ｂ２（ＴＸＢ２）、前列环素（６－Ｋｅｏｔｏ－ＰＧＦ１ａ）水平明显升高（Ｐ＜０．０１），致伤后２、４、６ｈＰＬＡ２活性分别为致伤前的１．９、２．８和３．３倍，肺动脉压（Ｐｐａ）和肺淋巴流量明显升高。应     

雌雄激素受体与胃癌发生发展的相关性研究

本文应用葡聚糖包裹活性炭饱和分析法检测了４０例胃癌组织及其相应癌远隔胃粘膜组织中的雌激素受体（ＥＲ）和雄激素受体（ＡＲ）。结果显示：４０例胃癌组织中ＥＲ阳性率为１５％（６／４０），含量为１５３４＋１００．８ｆｍｏｌ／ｍｇ蛋白质，而在相应癌远隔组织中未检测到ＥＲ；胃癌组织中ＡＲ的阳性率为４５％（１８／４０），含量为１８８±１２．５ｆｍｏｌ／ｍｇ蛋白质，相应癌远隔组织中ＡＲ的阳性率为１５％（６／４０），含量为１９．１±９．４ｆｍｏｌ／ｍｇ蛋白质，而且癌组织中ＡＲ的含量高于相应癌远隔组织（Ｐ＜０．０５）；胃癌的ＡＲ、ＥＲ与患者的年龄、性别、肿瘤大小、肿瘤分型及细胞分化程度均无明显的相关性。     

过热对大鼠下丘脑肾上腺素α2受体的影响

本文用ＳＤ大鼠，清醒状态于热环境中引起过热（至直肠温度３９．５±０．５℃和４２．０±０．５℃，并维持３０ｍｉｎ），用放射配基结合分析方法（￣３Ｈ－ｄｏｎｉｄｉｎｅ）发现急性热暴露后，其４２℃组α＿２受体最大结合容量（Ｂｍａｘ）为４５．０±１７．７ｍｏｌ／ｍｇ蛋白，低于对照组（７５．５±２３．９ｆｍｏｌ／ｍｇ蛋白）和３９．５℃组（８１．１±２１，７ｆｍｏｌ／ｍｇ），而亲和力（Ｋｄ）无显著差别．结果表明，在过热状态下，α＿２受体数量明显下降，但其亲和力并不下降。由于α＿２受体密度的下降，可能使儿茶酚胺对体温调节中枢的作用下降。     

糖皮质激素受体减少对严重烫伤大鼠体内炎症介质水平的影响

目的：阐明糖皮质激素受体（ＧＲ）减少对严重烫伤大鼠体内几种炎闰介质水平的影响。方法：以ＲＵ３８４８６阻断严重烫伤大鼠体内的ＧＲ,观察其血浆磷脂酶Ａ２（ＰＬＡ２）活性、肿瘤坏在子α（ＴＮＦα）和丙二醛（ＭＤＡ）呈以及脏器组织匀浆中ＰＬＡ２活性和ＭＤＡ含量变化。结果：烫伤后８ｈ,大鼠血浆及肺、肾组织匀浆中ＰＬＡ２活性,ＭＤＡ和ＴＮＦ含量均明显高于假处理对照组;烫伤复合ＧＲ阻断组以上效应更显著。结论：烫     

急性肺损伤大鼠肺组织β和β2受体及β2受体mRNA表达的变化

目的：观察急性肺损伤（ＡＬＩ）大鼠肺组织β、β２受体和β２受体ｍＲＮＡ含量的变化,探讨上述变化与ＡＬＩ的关系及β２受体变化可能的分子机制。方法：静注内毒素复制大鼠ＡＬＩ模型,肺组织β、β２受体及β２受体ｍＲＮＡ含量,分别用放射性配基结合分析法和斑点杂交技术测定。结果：静注内毒素后１、４、６ｈ,大鼠肺组织β和β２受体的最大结合容量（Ｂｍａｘ）均明显低于正常对照组（Ｐ＜０．０１）,尤以β２受体为甚;静注内毒素后４及６小时,大鼠肺组织β２受体ｍＲＮＡ含量分别下降至正常对照组的７６４％±１９６％（Ｐ＜０．０１）和５２８％±２０４％（Ｐ＜０．０１）。结论：肺组织β受体数目的减少在ＡＬＩ发生发展中可能起一定的作用,β２受体数目的减少可能与ＡＬＩ关系更密切;β２受体ｍＲＮＡ含量的减少可能是ＡＬＩ后一定阶段肺组织β２受体数目减少的原因之一。     

大鼠内毒素性肺损伤中肺α1和β受体的变化

本研究动态观察大鼠内毒素性肺损伤中肺α１－和β－ＡＲ的变化，以探讨肺ＡＲ变化与急性肺损伤的关系及其机制。结果表明，内毒素诱导大鼠急性肺损伤过程中，肺α１－ＡＲ和β－ＡＲ的Ｂｍａｘ值均明显降低（下调），分别较对照组下降３５和４３％。β－ＡＲ下调可能是导致急性肺损伤的原因之一；α－ＡＲ下调则是一种保护性反应。活性氧在肺ＡＲ下调中起重要作用，而循环血去甲肾上腺素和肾上腺素水平的升高不是其主要因素。静注肿     

急性低氧性肺动脉高压与磷脂酶A2活力关系初探

目的：探讨ＰＬＡ２及相关炎症介质在急性低氧性肺动脉高压形成中的作用。方法：用３０只ＳＤ大鼠随机分为三组（各１０只）：正常对照组（Ａ）、低氧组（Ｂ）、低氧加地塞米松组（Ｃ）。测定磷脂酶Ａ２活力（ＰＬＡ２）、血小板活化因子（ＰＡＦ）、前列腺素Ｅ２（ＰＧＥ２）、血栓素Ｂ２（ＴＸＢ２）。结果：Ｂ组低氧３０ｍｉｎ后，平均肺动脉压（ｍＰＡＰ）、血及肺中ＰＬＡ２活力、ＰＧＥ２、ＴＸＢ２、ＰＡＦ均明显增高；Ｃ组上述指标均明显低于Ｂ组。低氧情况下，ＰＬＡ２与ｍＰＡＰ、ＰＡＦ、ＰＧＥ２、ＴＸＢ２均呈正相关；ＰＡＦ、ＰＧＥ２、ＴＸＢ２分别又与ｍＰＡＰ呈正相关。结论：ＰＬＡ２通过相关炎症介质在急性低氧性肺动脉压的形成中可能起重要的介导作用。     

IL—10抗内毒素气管内滴注致急性肺损伤作用的实 …

目的：探讨中性粒细胞（ＰＭＮ）在急性肺损伤（ＡＬＩ）发生中的作用及ＩＬ－１０对ＡＬＩ的拮抗作用。方法：用ＬＰＳ（１００μｇ／只）或ＬＰＳ＋ＩＬ－１０（１μｇ／只）向ＳＤ大鼠气管内滴注复制ＡＬＩ模型，检测支气管肺泡灌洗液（ＢＡＬＦ）中ＰＭＮ数目、蛋白质及丙二醛（ＭＤＡ）含量，并进行组织学观察。结果：ＬＰＳ气管内滴注可引起ＢＡＬＦ中ＰＭＮ数目明显增加，伴有蛋白质及ＭＤＡ含量的增高，光镜观察显示肺组织间     

The separation of three antibody populations from anti-poly(A).poly(U) antibodies elicited in mice or rabbits and antigenic features of poly(A).poly(U))

Anti-poly(A).poly(U) antibodies in ascitic fluid of DDY mice immunized with poly(A).poly(U)-methylated bovine serum albumin complexes were fractionated into three major antibody populations, Ab-1, Ab-2 and Ab-3, by precipitating with poly(I).poly(C), poly(A).poly(U), and poly(A).2 poly(U), respectively. Antibody population one, Ab-2, reacted with various double-stranded RNAs [poly(I).poly(C), poly(A).poly(U), and rice dwarf virus ribonucleic acid (RDV-RNA)] and poly(A).2 poly(U). Ab-2 reacted with poly(A).poly(U) and poly(A).2 poly(U). Although both Ab-1 and Ab-2 reacted with poly(A).poly(U), the two populations were distinguishable by their different reactivities against chemically modified antigens and oligonucleotides. In contrast to Ab-2, acetylation at the furanose 2'-position of poly(U) resulted in a dramatic decrease in the complement fixation reactivity of Ab-2. Also, Ab-2 was capable of binding with complexes of hexa- to heptaadenylates and poly(U), whereas Ab-1 required oligoadenylates of longer chain lengths (9-10 chain length) for binding. Therefore, it appears that poly(A).poly(U) possesses unique antigenic determinants which are recognizable only by Ab-2, in addition to those determinants which are common to a variety of double-stranded RNAs.     

Gab2在人骨肉瘤细胞U2-OS中的表达及意义

目的:探讨Grb2协同结合蛋白2(Gab2)在人骨肉瘤细胞系中的表达及其与人骨肉瘤细胞侵袭转移的关系。方法:应用小RNA干扰技术,将合成的小RNA干扰质粒转染给人骨肉瘤U2-OS细胞,采用Western blotting和RT-PCR法检测转染后Gab2的蛋白和mRNA表达水平;体外细胞趋化运动实验和侵袭实验检测细胞的迁移和侵袭能力。结果:Gab2在人骨肉瘤U2-OS细胞系中高表达,且转染Gab2 siRNA后的细胞(Si Gab2/U2-OS)中Gab2蛋白及mRNA的表达水平低于转染scramble siRNA细胞(Scr/U2-OS)和U2-OS;趋化运动实验发现在10μg/L表皮生长因子(EGF)的诱导下Si Gab2/U2-OS细胞的迁移能力较U2-OS和Scr/U2-OS细胞明显下降,差异有统计学意义(P0.01);Si Gab2/U2-OS细胞侵袭并穿透Matrigel膜基质的细胞数量均比Scr/U2-OS细胞和U2-OS细胞少,Si Gab2/U2-OS细胞的体外侵袭能力显著降低(P0.01)。结论:利用siRNA干扰技术降低Gab2的表达对人骨肉瘤U2-OS细胞的迁移和侵袭能力有明显的抑制作用。     

Cytokines production of U5A2-13-positive T cells by stimulation with glycolipid alpha-galactosylceramide

We have previously established and reported a novel monoclonal antibody (mAb), U5A2-13, which recognizes a phenotypically similar population of natural killer (NK)-like T cells. Using U5A2-13 mAb, we now describe the functional properties of U5A2-13(+) T cells in both NK1.1-positive or -negative mouse strains. Similar to NK1.1(+) T cells, hepatic U5A2-13(+) T cells of C57BL/6 (NK1.1(+) strain) mice, but not U5A2-13(-) T cells, could be induced to produce large amounts of IL-4 and IFN-gamma by stimulation with glycolipid alpha-galactosylceramide (alpha-GalCer) present on dendritic cells (DC) in a dose-dependent manner. The abundant production of these cytokines from U5A2-13(+) T cells of BALB/c (NK1.1(-) strain) mice is similar to that noted in C57BL/6 mice. Cytokine production by cultures stimulated with DC of beta2-microglobulin-deficient mice was significantly less than that of cultures stimulated with DC of intact mice. Overall, U5A2-13(+) T cells recognize alpha-GalCer presented by CD1d, indicating that U5A2-13(+) T cells can be used to analyze NK-like T cell function in various strains of mice.     

The anti-tumor drug E7107 reveals an essential role for SF3b in remodeling U2 snRNP to expose the branch point-binding region

Duplex formation between the branch point-binding region (BBR) of U2 snRNA and the branch point sequence (BPS) in the intron is essential for splicing. Both the BBR and BPS interact with the U2 small nuclear ribonucleoprotein (snRNP)-associated SF3b complex, which is the target of the anti-tumor drug E7107. We show that E7107 blocks spliceosome assembly by preventing tight binding of U2 snRNP to pre-mRNA. E7107 has no apparent effect on U2 snRNP integrity. Instead, E7107 abolishes an ATP-dependent conformational change in U2 snRNP that exposes the BBR. We conclude that SF3b is required for this remodeling, which exposes the BBR for tight U2 snRNP binding to pre-mRNA.     

血清HBsAg与HBV DNA水平与乙肝患者肝纤维化程度的相关性分析

目的 探讨血清HBsAg与HBV DNA对乙肝患者肝纤维化的相关性分析.方法 选取2010年5月至2014年9月在我院进行治疗的100例肝脏穿刺活组织学检查的患者,根据肝脏炎症程度将患者分为G0-G1、G2、G3-G4三组,根据不同纤维化分期将患者分为S0-S1、S2、S3、S4四组,根据丙氨酸转氨酶(ALT)水平,将患者分为A1 (ALT≤40U/L)组、A2(40＜ALT≤80U/L)组,对不同分组患者进行血清HBsAg测定、HBV DNA测定及ALT测定,分析其含量与肝脏炎症程度及纤维化程度的相关性.结果 G0-G1组、G2组、G3-G4组HBsAg定量分别为(3.85±0.87)U/ml、(3.54±0.79) U/ml、(2.79 ±0.58) U/ml,三组间具有统计学差异(P＜0.05).G0-G1组、G2组、G3-G4组HBV DNA定量分别为(6.27±1.67) U/ml、(5.68±1.49) U/ml、(5.84±1.59) U/ml,三组间差异无统计学差异(P＞0.05).S0-S1组、S2组、S3组、S4组患者HBsAg定量分别为(3.95±0.93) U/ml、(3.62±0.86) U/ml、(3.55±0.62) U/ml、(3.35 ±0.54) U/ml,四组差异有统计学差异(P＜0.05).S0-S1组、S2组、S3组、S4组患者HBV DNA定量分别为(6.23±1.72) U/ml、(5.79±1.62U/ml)、(5.50±1.48) U/ml、(5.48±1.35U/ml),四组差异有统计学意义(P＜0.05).ALT水平与炎症程度及纤维化程度没有相关性(P＞0.05).结论 HBsAg、乙肝病毒随着肝纤维化程度的加重逐渐减低,血清HBsAg结合HBV DNA载量作为检测乙肝病毒感染者肝纤维化指标更为可靠.     

Thromboxane a(2) induces differentiation of human mesenchymal stem cells to smooth muscle-like cells

Thromboxane A(2) (TxA(2)) is involved in smooth muscle contraction and atherosclerotic vascular diseases. Accumulating evidence suggests a pivotal role for mesenchymal stem cells (MSCs) in vascular remodeling. In the present study, we demonstrate for the first time that the TxA(2) mimetic U46619 induces differentiation of human adipose tissue-derived MSCs (hADSCs) to smooth muscle-like cells, as demonstrated by increased expression of smooth muscle-specific contractile proteins such as alpha-smooth muscle actin (alpha-SMA), calponin, smoothelin, and smooth muscle-myosin heavy chain. Using an in vitro collagen gel lattice contraction assay, we showed that U46619-induced expression of the contractile proteins was associated with increased contractility of the cells. U46619 increased the intracellular Ca(2+) concentration in hADSCs and pretreatment of the cells with the thromboxane receptor antagonist SQ29548 or the calmodulin (CaM) inhibitor W13 abrogated the U46619-induced alpha-SMA expression and contractility, suggesting a pivotal role of Ca(2+)/CaM in the U46619-stimulated smooth muscle differentiation of hADSCs. In addition, U46619 elicited activation of RhoA in hADSCs, and pretreatment of the cells with the Rho kinase-specific inhibitor Y27632 or overexpression of the dominant-negative mutants of RhoA and Rho kinase blocked U46619-stimulated alpha-SMA expression and contractility. Furthermore, U46619 induced phosphorylation of myosin light chain (MLC) through CaM/MLC kinase- and Rho kinase-dependent pathways, and the MLC kinase inhibitor ML-7 abrogated U46619-induced alpha-SMA expression and contractility. These results suggest that U46619 induces differentiation of hADSCs to contractile smooth muscle-like cells through CaM/MLCK- and RhoA-Rho kinase-dependent actin polymerization.     

Mammalian U2 snRNP has a sequence-specific RNA-binding activity

The RNA branch formed during pre-mRNA splicing occurs at a wide variety of sequences (branch sites) in different mammalian pre-mRNAs. U2 small nuclear ribonucleoprotein (snRNP) binds to the pre-mRNA branch site following the interaction of a protein, U2AF, with the 3' splice site/polypyrimidine tract. Here we show that despite the variability of mammalian branch sites, U2 snRNP has a sequence-specific RNA-binding activity. Thus, RNA branch formation is regulated by two sequence-specific interactions: U2AF with the 3' splice site/polypyrimidine tract, and U2 snRNP with the branch site. The affinity of the branch site for U2 snRNP affects the efficiency of spliceosome assembly and splicing.     

The Prp8 RNase H-like domain inhibits Brr2-mediated U4/U6 snRNA unwinding by blocking Brr2 loading onto the U4 snRNA

The spliceosomal RNA helicase Brr2 catalyzes unwinding of the U4/U6 snRNA duplex, an essential step for spliceosome catalytic activation. Brr2 is regulated in part by the spliceosomal Prp8 protein by an unknown mechanism. We demonstrate that the RNase H (RH) domain of yeast Prp8 binds U4/U6 small nuclear RNA (snRNA) with the single-stranded regions of U4 and U6 preceding U4/U6 stem I, contributing to its binding. Via cross-linking coupled with mass spectrometry, we identify RH domain residues that contact the U4/U6 snRNA. We further demonstrate that the same single-stranded region of U4 preceding U4/U6 stem I is recognized by Brr2, indicating that it translocates along U4 and first unwinds stem I of the U4/U6 duplex. Finally, we show that the RH domain of Prp8 interferes with U4/U6 unwinding by blocking Brr2''s interaction with the U4 snRNA. Our data reveal a novel mechanism whereby Prp8 negatively regulates Brr2 and potentially prevents premature U4/U6 unwinding during splicing. They also support the idea that the RH domain acts as a platform for the exchange of U6 snRNA for U1 at the 5′ splice site. Our results provide insights into the mechanism whereby Brr2 unwinds U4/U6 and show how this activity is potentially regulated prior to spliceosome activation.