Endothelin-1, an important mitogen of smooth muscle cells of spontaneously hypertensive rats

OBJECTIVE: To study the features of vascular smooth muscle cell (VSMC) proliferation induced by endothelin-1 (ET-1). METHODS: VSMCs of spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats were cultured and treated with ET-1. Basic fibroblast growth factor (bFGF) gene expression was measured using both Northern blot and an enzyme-linked immunoassay. RESULTS: ET-1 resulted in an increase in bFGF transcripts at 8 - 24 h; bFGF levels were significantly higher in VSMCs treated with ET-1 than in those not treated. However, VSMCs growth responses in SHR and WKY were different. Smooth muscle cells of SHR were hyper-responsive to ET-1. Maximal bFGF mRNA levels were elevated 3.5-fold at 4 h of stimulation in WKY and 8-fold at 8h in SHR4. Moreover, the proliferation of VSMCs induced by ET-1 was inhibited by antisense phosphorothioate oligodeoxynucleotides (10 micromol/L AS-bFGF) but not sense bFGF oligomers at the same concentrations, being reduced by 80% in SHR and 40% in WKY vs control, respectively. Furthermore, the effect of AS-bFGF oligomers on SHR SMC proliferation is significantly greater than on WKY SMC proliferation. CONCLUSION: ET-1 may be required for exaggerated vascular growth responses in SHR and bFGF may be involved.

Influence of Valsartan on myocardial apoptosis in spontaneously hypertensive rats

OBJECTIVE: To explore the pathogenic changes of myocardial apoptosis in heart hypertrophy during hypertension and evaluate the anti-apoptosis effect of Valsartan. METHODS: Thirty spontaneously hypertensive rats (SHRs) were divided into two groups: 15 treated with Valsartan (20 mg x kg(-1) x d(-1)) (SHR + Valsartan group), the others with placebo (SHR + placebo group), with 15 normal Wistar rats as control. Systolic blood pressure was measured by the tail-cuff method. The observation period was from 8 to 16 weeks of age. Cardiac apoptosis was evaluated by a Terminal Deoxynucleotidyl Transferase-Mediated dUTP-biotin Nick End Labeling (TUNEL) assay. RESULTS: Mean blood pressure values were 127 +/- 2 mm Hg in controls, 163 +/- 6 mm Hg in the SHR + Valsartan group and 193 +/- 7 mm Hg in the SHR + placebo group at 16 weeks of age, whereas the blood pressure in 8-week-old SHR and Wistar rats were 175 +/- 3 mm Hg and 125 +/- 5 mm Hg, respectively. The ratio of the heart weight over body weight declined in Wistar (3.07 +/- 0.03 mg/g) and SHR + Valsartan groups (3.22 +/- 0.19 mg/g) compared with the SHR + placebo group (4.02 +/- 0.31 mg/g) (P

Endothelin receptor antagonist combined with a calcium channel blocker attenuates renal injury in spontaneous hypertensive rats with diabetes

OBJECTIVE: To investigate the effects of the mixed endothelin receptor antagonist, bosentan, combined with the long-acting calcium channel blocker, amlodipine, compared to the angiotensin-converting enzyme inhibitor, cilazapril, on the progressive renal injury in spontaneous hypertensive rats (SHR) with diabetes. METHODS: Diabetic hypertensive rats (SHR-DM) were induced by streptozotozin injected in male SHR (7-week-old),and divided into an untreated and three treated groups: 1) cilazapril treated group; 2) bosentan+amlodipine treated group; and 3) amlodipine treated group. Wistar Kyoto rats (WKY) and SHR rats served as normotensive and hypertensive control, respectively. The mean arterial blood pressure, renal function, endothelin and angiotensin II levels as well as the protein expression of renal extracellular matrix components and transforming growth factor (TGF)-beta1 were determined at the end of the 4th week. RESULTS: Mean arterial blood pressure significantly increased in SHR and SHR-DM rats compared to WKY rats. All the therapies reduced the blood pressure to normal levels. However, the enhanced urinary protein excretion, the decreased creatinine clearance as well as the increased plasma and intrarenal endothelin and angiotens in II levels were found in the untreated SHR-DM and prevented by treatment with bosentan+amlodipine and cilazapril. Similarly, these two kinds of therapies in SHR-DM abolished the overexpression of renal TGF-beta1 by Western blot analysis and reduced the accumulation of collagen type IV, laminin and fibronectin proteins by an immunochemical approach. Amlodipine monotherapy had no detectable effects on the above parameters. CONCLUSION: Bosentan combined with amlodipine can offer similar renoprotective effects on that of cilazapril and may be a potent therapy to attenuate renal injury by reducing renal protein levels of TGF-beta1 in diabetes with a hypertensive state.

Ventricular remodeling by Scutellarein treatment in spontaneously hypertensive rats

OBJECTIVE: To observe reversal of ventricular remodeling by the protein kinase C inhibitor Scutellarein in spontaneously hypertensive rats (SHRs). METHODS: Twelve SHRs were randomly divided into two groups. Scutellarein and saline (10 mg x kg(-1) x d(-1)) were given by intraperitoneal injection to two groups of rats separately. Systolic blood pressure (SBP) and ventricular weight index (LVW/BW, RVW/BW) were measured. A polarization microscope and an image analyzer system (IAS) were used to observe changes in cardiovascular structure and to count the content of cardiac muscle interstitial collagen. RESULTS: The pathologic changes in the left ventricle in the Scutellarein group rats (SHR(D)) improved to varying degrees, including hypertrophy of the cardiac muscle and collagen volume fraction. CONCLUSION: Scutellarein can reverse ventricular remodeling, improve myocardial stiffness and protect heart cardiac muscle.

Five novel monoclonal antibodies to thymic epithelial cell surface antigens in rats

OBJECTIVE: To establish monoclonal antibodies (mAbs) against thymic epithelial cells and study the function of epithelial cells during T-cell differentiation in the thymus. METHODS: Hybridomas secreting mAbs against thymic epithelial cells were derived by immunization of Balb/c mice with two thymic epithelial cell lines, TaD3 and FTE. The distribution of antigens recognized by these mAbs was detected by immunochemical staining and cytofluorographic analysis, and the molecular weight of the antigens by immunoblotting. RESULTS: Five specific monoclonal antibodies (mAb) were obtained. On the basis of their distribution in the thymus determined by immunochemical staining, mAb RE-4D8 was regarded as clusters of thymic epithelium staining (CTES) type IIA: mAb RE-12B2, which showed a unique distribution pattern only in the medulla, was CTES type V: mAb RE-5C6 was CTES type IV: mAb RE-6D6 might be CTES type IIB: and mAb RE-1D4 was classified as type V. The molecular weight (MW) of antigen RE-4D8, RE-6D6 and RE-12B2 were 120 kDa, 220 kDa and 35 kDa, respectively. Antigen RE-1D4 is a novel marker of cortical epithelium, several established thymic epithelial cell lines were classified and their original intrathymic locations were determined by these mAbs. Thymic cell lines, TuD3 and FTE were cortical phenotypes whereas TaD3 had a medullar phenotype. CONCLUSIONS: These mAbs clearly demonstrate the heterogeneity of the thymic epithelium; they could detect antigens not only in the cytoplasm but also on the surface of thymic epithelial cells. Our data suggest that these newly established mAbs may help elucidate the interaction between thymocytes and epithelial cells during T cell maturation.

PVG大鼠生化标记基因的测定

目的 对PVG大鼠进行生化标记基因的测定。方法 依据国家标准GB/T 14927.1—2008《实验动物近交系小鼠、大鼠生化标记检测法》测定,随机抽取4只PVG大鼠,取(肺、肾、小肠、睾丸)组织器官进行样品制备,用醋酸纤维薄膜电泳法检测11个生化位点(Hbb、Cs1、Alp1、Akp1、Esl、Es3、Es4、Es6、Es8、Es9和Esl0)。结果 PVG大鼠11个位点的基因型分别是Hbb为b型,Cs1为b型,Alp1为b型,Akp1为a型,Esl为a型,Es3为d型,Es4为b型,Es6为b型,Es8为b型,Es9为a型和Esl0为a型,且均为纯合。结论 PVG大鼠遗传生化标记结果符合近交系特征。

Effects of electroacupuncture at Taichong(LR 3) and Baihui(DU 20)on cardiac hypertrophy in rats with spontaneous hypertension

OBJECTIVE: To investigate the effects of electroacupuncture(EA) at Taichong(LR 3) and Baihui(DU 20)on myocardial hypertrophy in spontaneously hypertensive rats(SHRs).METHODS: Thirty-six SHRs were randomly assigned to model, EA, and Losartan groups, with twelve rats per group. Twelve Wistar Kyoto rats were selected as the normal control group. Systolic blood pressure(SBP) and cardiac function were measured in all rats.Expression levels of factors associated with the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/Akt/mTOR) pathway were evaluated by Western blotting and real-time PCR.Pathological changes of the heart tissue were observed by hematoxylin-eosin staining.RESULTS: After treatment, enhanced SBP was significantly decreased in the EA and Losartan groups compared with the model group(P < 0.01). Echocardiographic and morphological analyses revealed that enhanced end-diastolic interventricular septal thickness and left ventricular posterior wall thickness, as well as ratio of left ventricular weight to body weight were markedly diminished in the EA and Losartan groups(P < 0.01 or P < 0.05), while reduced left ventricular end-diastolic dimension and left ventricular ejection fraction were significantly ameliorated(P < 0.01). Real-time PCR and western blotting analyses showed that the expression levels of PI3K,Akt, and mT OR in SHRs were significantly up-regulated by EA and Losartan(P < 0.01), while the expression levels of PTEN and ANP were down-regulated(P < 0.01).CONCLUSION: EA at Taichong(LR 3) and Baihui(DU20) inhibited the development of cardiac hypertrophy and improved the cardiac function in SHRs, possibly through regulation of the PI3K/Akt/mTOR signalling pathway.

Effect of Taichong(LR 3) acupuncture in spontaneously hypertensive rats

OBJECTIVE: To evaluate the effects of Taichong(LR3) acupuncture points(acupoints) on the expression of glucose transporter protein 1(GLUT1) in the hypothalamus of spontaneously hypertensive rats(SHRs) as measured by combined positron emission tomography and computed tomography(PETCT).METHODS: Spontaneously hypertensive rats(SHR)were divided into model, Taichong(LR 3) acupuncture, and sham groups. Additionally, Tokyo Wistar rats were used as the control group. Changes in blood pressure were recorded in different groups of rats before and after the corresponding treatment. Hematoxylin and eosin(HE) staining was used to study basic morphological changes, and immunohistochemistry was used to determine GLUT1 expression in the hypothalamus. Further,PET-CT was utilized to elucidate the antihypertensive mechanism after acupuncture at the Taichong(LR 3) acupoints.RESULTS: PET-CT indicated activation of the hypothalamus. Measurement of blood pressure showed that acupuncture at the Taichong(LR 3) acupoints lowered blood pressure. HE staining did not show any significant pathological changes, although differences in cell number were observed. Immunohistochemical analysis indicated a GLUT1 downregulation in the SHRs of the Taichong(LR 3) acupuncture group after the treatment.CONCLUSION: Acupuncture at Taichong(LR 3) acupoints lowered blood pressure in SHRs, with possible mechanisms being changes in cell number and GLUT1 expression in the hypothalamus.

Mechanism and effect of Shijueming (Concha Haliotidis) on serum calcium in spontaneously hypertensive rats

OBJECTIVE： To observe the impact of Shijueming （Concha Haliotidis） on spontaneously hypertensive rats via blood pressure, serum calcium, vascular smooth muscle membrane L-type calcium channel α1 C subunit （CaL-α1C）, plasma membrane calci- um-ATPase （PMCA） mRNA expression, and the L-type calcium channel in vascular smooth muscle cells. METHODS： Twelve-week-old male rats with sponta- neous hypertension were divided into three groups： a Shijueming （Concha Haliotidis） group （group 1）, a nifedipine group （group 2）, and a dis- tilled water group （group 3）. All were given a four-week treatment. Blood pressure and dissocia- tive serum calcium were examined before treat- ment. Blood pressure was taken every week during treatment. Atomic absorption spectrometry was used to examine dissociative serum calcium. Re-verse transcription-polymerase chain reaction was used to examine the expression of CaL-α1C and PM- CA1 mRNA. The patch clamp technique was used to examine the electrophysiological characteristics of the vascular smooth muscle cell calcium chan- nels. RESULTS： After treatment, blood pressure of the Shijueming （Concha Halioticlis） group lowered but not significantly （P〉0.05）. Blood pressure of the nifedipine group lowered significantly （P〈0.05）. Blood pressure of the distilled water group re- mained high. The concentration of serum calcium in the Shijueming （Concha Haliotidis） and the dis- tilled water groups lowered （P〈0.05）. Expression of CaL-α1C mRNA in the nifedipine group decreased compared with the distilled water group （P〈0.01）. There was the decreasing trend in the Shijueming （Concha Haliotidis） group, but it was not statistically significant. Shijueming （Concha Haliotidis） also had effects on the expression of PMCA1 mRNA but with- out statistical significance. However, there was a significant decreasing effect on vascular smooth muscle cell Ica-L flow. CONCLUSION： This study indicated that Shijuem- ing （Concha Haliotidis） could increase serum calci- um and decrease blood pressure. It may work by in- fluencing calcium channels, expression of PMCA1 mRNA, and regulating ion calcium channels and calcium-ATPase.

Proliferation of aortic smooth muscle cells and renin-angiotensin system in SHR rats

目的：探讨ＳＨＲ大鼠主动脉平滑肌细胞（ＡＳＭＣ）异常增殖和肾素血管紧张素系统（ＲＡＳ）的关系．方法：测定血管紧张素Ｉ（Ａｎｇ）、卡托普利（Ｃａｐ）、沙拉新（Ｓａｒ）对培养的ＳＨＲ、ＷＫＹＡＳＭＣ增殖和Ａｎｇ、血管紧张素转化酶（ＡＣＥ）的影响．结果：Ａｎｇ在２％血清培养基中可刺激ＳＨＲＡＳＭＣ增生．ＳＨＲＡＳＭＣ分裂增殖能力比ＷＫＹ强，ＳＨＲＡＳＭＣＲＡＳ处于高功能状态．Ｃａｐ长期（４周）干预显著抑制ＳＨＲＡＳＭＣ异常增殖和Ａｎｇ、ＡＣＥ活性，Ｓａｒ长期干预同样抑制ＳＨＲＡＳＭＣ的增殖和ＡＣＥ活性，但Ａｎｇ水平反而升高．Ｃａｐ短期（２４小时）干预不影响两种大鼠ＡＳＭＣＲＡＳ．结论：Ｃａｐ和Ｓａｒ长期干预通过减少ＳＨＲＡＳＭＣＡｎｇ生成或阻断Ａｎｇ和特异受体结合，抑制其异常增殖．

Upregulation of the angiotensin-converting enzyme 2-angiotensin-(1-7)-Mas receptor axis by a combination of Yinyanghuo(Herba Epimedii Brevicornus) and Cheqianzi(Semen Plantaginis) improves erectile function in spontaneously hypertensive rats

OBJECTIVE:To evaluate the effects of a combination of Yinyanghuo(Herba Epimedii Brevicornus)(HEB)and Cheqianzi(Semen Plantaginis)(SP)on erectile dysfunction caused by essential hypertension in spontaneously hypertensive rats(SHRs),and to elucidate the role of the angiotensin-converting enzyme 2-angiotensin-(1-7)-Mas receptor(ACE2/Ang[1-7]/Mas receptor)axis in this process.METHODS:A total of 24 SHRs were randomly assigned to three groups:SHR-control,low-dose(12.5 g/kg)and high-dose(25 g/kg)HEB+SP(HEBSP).Eight Wistar-Kyoto rats were used as normal controls.HEBSP was administered by oral gavage for 28 d.Erectile function was measured once a week using the Heaton test.After 4 weeks of treatment,the corpus cavernosum was harvested from each rat to measure nitric oxide(NO),nitric oxide synthase(e NOS)and Ang(1-7)levels,as well as ACE2,Mas receptor and neuronal nitric oxide synthase(n NOS)protein expression.RESULTS:After 4 weeks of treatment,HEBSP significantly increased erectile function in the treated group compared with SHR-control group(P<0.01).Additionally,HEBSP treatment significantly increased cavernosal levels of Ang(1-7),e NOS and NO.Moreover,HEBSP significantly elevated the expression levels of ACE2,Mas receptor and n NOS.These beneficial effects were elevated in the high-dose HEBSP group.CONCLUSION:HEBSP improved erectile function in SHRs by upregulating the ACE2/Ang(1-7)/Mas receptor axis,e NOS and n NOS pathways.

建立6种近交系大鼠遗传质量检测及品系鉴别的单核苷酸多态性组合

目的 筛选出均匀分布在大鼠染色体上的单核苷酸多态性(SNP)位点,建立常用近交系大鼠遗传质量检测及品系鉴别方法。方法 在文献中获得SNP共141个,利用Ensembl数据库中获取的信息筛选出在BN、F344、GK、LEW、SHR和WKY 6种大鼠品系中呈现多态性的SNP位点,并从中优化出均匀分布各染色体且包含品系特异性SNP的最佳位点组合。通过PCR扩增技术和Sanger测序方法对组合位点用于常用近交系大鼠遗传质量检测和品系鉴别的效果进行验证。结果 优化出了在各品系内表现单态性、品系间呈多态性的40个SNP标记。其中包含可以用于品系鉴别的特异性位点:4个BN大鼠特异性位点,3个F344大鼠特异性位点,2个GK大鼠特异性位点,2个LEW大鼠特异性位点和1个SHR大鼠特异性位点。分别利用BN、F344、LEW、SHR和WKY大鼠的DNA混合样本对优化出的40个位点进行验证,结果与网站数据一致。结论 成功建立了常用近交系大鼠遗传质量检测及品系鉴别的SNP组合。

Tong-xin-luo capsule inhibits left ventricular remodeling in spontaneously hypertensive rats by enhancing PPAR-γ expression and suppressing NF-κB activity

Background Tong-xin-luo capsule （TXL）, used as a traditional Chinese herb, offeres a therapeutic potential for treatment of cardiovascular diseases. It has been shown to exert a variety of pharmacological effects, including antihypertensive effects, and is able to improve ventricular remodeling. However, the mechanisms of its action are not completely understood. The aim of this study was to evaluate the molecular mechanisms of Tong-xin-luo capsule on left ventricular remodeling in spontaneously hypertensive rats （SHR）. Methods Sixteen eight-week-old SHRs were randomized into an SHR group （n=8） and a TXL group （n=8） that were given Tong-xin-luo capsule （1.5 mg·kg^-1·d^-1）. Eight Wistar Kyoto （WKY） rats fed with 0.9% NaCl served as the control group （WKY group）. Systolic blood pressure （BP）, body weight and heart rate were monitored once every two weeks. Ventricular remodeling was detected by histopathological examination. Nuclear factor kappa B P65 （NF-κB P65） and peroxisome proliferators activated receptor y （PPAR-γ） protein and phosphorylated inhibitor kappa a （IκBα） protein were detected by immunohistochemistry and western blot respectively. The physical interaction of the P65-P50 heterodimer with IκBα and NF-κB were measured by co-immunoprecipitation. PPAR-γ mRNA, collagen Ⅰ mRNA and collagen Ⅲ mHNA were measured by real-time PCR.Results TXL inhibited NF-κB P65 expression and ventricular remodeling and suppressed the activation of NF-κB compared with the SHR group （P〈0.01, P〈0.05）. TXL reduced IκBα phosphorylation, increased expression of PPAR-γ protein and enhanced the physical interaction of the P65-P50 heterodimer with IκBα. The mRNA expression of PPAR-γ was enhanced but the mRNA expression of collagen Ⅰ mRNA and collagen Ⅲ mRNA were suppressed by TXL. Conclusions In spontaneously hypertensive rats, TXL could inhibit ventricular remodeling induced by hypertension, and the inhibitory effect might be associated with the process of TXL increasing the expression of PPAR-γ that could result in the inhibition of the activation of NF-κB.

Inhibitory effect of antisense basic fibroblast growth factor oligonucleotides on proliferation of cultured aortic smooth muscle cells induced by angiotensin Ⅱ in SHR rats

目的：研究转染反义碱性成纤维细胞生长因子（ｂＦＧＦ）寡核苷酸（ＯＤＮ）对培养的自发性高血压大鼠（ＳＨＲ）主动脉平滑肌细胞（ＳＭＣ）生长的影响．方法：用脂质体介导法将反义ｂＦＧＦＯＤＮ转入ＳＭＣ内，用Ｎｏｒｔｈｅｒｎ杂交检测ｂＦＧＦ基因表达，并测定［３Ｈ］ｔｈｙｍｉｄｉｎｅ掺入和细胞计数．结果：转染反义ｂＦＧＦＯＤＮ（５μｍｏｌ·Ｌ－１）几乎完全抑制血管紧张素Ⅱ（ＡｎｇⅡ，１μｍｏｌ·Ｌ－１）诱导增高的ｂＦＧＦｍＲＮＡ表达和明显抑制ＳＭＣ增殖，在基础状态和ＡｎｇⅡ刺激条件下，［３Ｈ］ｔｈｙｍｉｄｉｎｅ掺入分别被抑制２６５％（Ｐ＜００１）和４２０％（Ｐ＜００１），细胞数分别被抑制１７３％（Ｐ＜００１）和２２２％（Ｐ＜００１）．结论：反义ｂＦＧＦＯＤＮ能有效抑制ＡｎｇⅡ诱导的ｂＦＧＦ基因表达和ＳＭＣ增殖．

蓝光致棕色挪威大鼠慢性视网膜光损伤的实验研究

目的通过构建蓝光致棕色挪威(Brown Norway,BN)大鼠慢性视网膜光损伤的模型,探究大鼠光感受器细胞及视网膜色素上皮细胞(RPEc)损伤的特点及可能损伤机制。方法根据随机数字表法将大鼠分组为光照0 d(正常对照组)和光照1、3、7及14 d组,每组8只。正常对照组不进行光照;余各组每日暴露于光照强度为(1000±100)Lux的LED蓝光光源环境中3 h,连续1、3、7及14 d,观察大鼠的行为活动;视网膜电流图(ERG)记录最大混合反应的a、b波振幅和潜伏期;进行眼底照相;HE染色观察视网膜组织;酶联免疫吸附试验(ELISA)检测大鼠视网膜组织的活性氧(ROS)含量。结果与正常对照组比较,光照3 d组对光声刺激的反应迟钝,光照7 d及14 d组精神较萎靡,行动稍迟缓,对光声刺激反应更为迟钝;光照3 d组偶见视网膜出血点,RPEc层基底部色素颗粒增多,外核层可见轻度细胞核固缩;光照7 d组视网膜上见散在点状出血点、黄白色点状颗粒物,视网膜静脉迂曲扩张;光照14 d组视网膜上见大量黄白色点状渗出,视网膜动脉呈铜丝样甚至银丝样外观,视网膜静脉迂曲扩张;光照7、14 d组视网膜光感受器内节/外节结构排列紊乱,外核层细胞核固缩,RPEc层基底部色素颗粒沉积。与正常对照组比较,光照3、7、14 d组大鼠视网膜变薄(P<0.05);光照3、7及14 d组ERG b波潜伏期逐渐延长、a波、b波振幅逐渐降低,视网膜组织ROS逐渐升高(P<0.05)。结论蓝光持续照射BN大鼠可产生氧化应激反应,导致慢性视网膜光损伤,且照射时间越长,视网膜光损伤越重。

腺病毒介导PD-L1基因局部转染供肾在缓解肾移植排异反应中的机制

目的探讨腺病毒介导程序性死亡受体配体1(PD-L1)基因局部转染供肾在缓解肾移植排异反应中的作用机制。方法选择24只健康Lewis雄性大鼠作为肾脏供体,另选24只Wistar雄性大鼠作为受体。所有无特定病原体(SPF)的大鼠3个月龄,体重(300±30)g。将受体大鼠按随机数字表法分为对照组、空白组和转染组。采用实时PCR和Western blot法检测PD-L1的表达。比较受体大鼠存活率与血清肌酐水平,酶联免疫吸附测定(ELISA)检测γ干扰素(IFN-γ)、白细胞介素-2(IL-2)、白细胞介素-6(IL-6)和白细胞介素-10(IL-10)的水平。结果转染组大鼠平均存活时间长于空白组及对照组,差异有统计学意义(P<0.05),转染组大鼠平均体重高于空白组及对照组,差异有统计学意义(P<0.05),转染组大鼠的血肌酐水平低于空白组及对照组,差异有统计学意义(P<0.05);空白组和对照组的平均存活时间、体重及血肌酐比较差异无统计学意义(P>0.05)。转染组大鼠PD-L1 mRNA和蛋白的表达高于对照组及空白组,差异有统计学意义(P<0.05);对照组和空白组大鼠PD-L1中mRNA和蛋白表达比较,差异无统计学意义(P>0.05)。转染组大鼠细胞因子IL-10和IL-6高于对照组及空白组,IFN-γ和IL-2低于对照组及空白组(P<0.05);对照组和空白组大鼠细胞因子IL-10、IL-6、IFN-γ和IL-2比较,差异无统计学意义(P>0.05)。结论腺病毒介导的PD-L1转染供肾通过调节免疫因子的表达,调节Th1/Th2细胞因子平衡,提高受体功能,抑制肾脏排异反应,延长移植肾存活时间。

基于多重PCR-LDR技术建立近交系大鼠单核苷酸多态性遗传检测方案

目的建立一套基于多重PCR-连接酶检测反应(ligase detection reaction,LDR)技术的近交系大鼠单核苷酸多态性(single nucleotide polymorphisms,SNP)检测方案。方法在5个品系的SPF级近交系大鼠1~20号常染色体和X染色体上共选取40个大鼠SNP位点,将SNP位点随机分为4组,构建基于多重PCR-LDR技术的近交系大鼠4组SNP位点基因检测方案。采用本方案检测国内另两家大鼠供应商的9个常用大鼠品系。最后,通过第三方实验室对不同DNA聚合酶的扩增效果进行比对,验证本方案的可行性。结果用所构建的近交系大鼠SNP遗传检测方案测试5个大鼠品系时,各样本的所有位点均得到了良好的扩增结果。采用本方案检测国内另两家大鼠供应商的9个常用大鼠品系时也得到了良好的扩增结果,40个SNP位点在每个近交系大鼠中均为纯合。用3种来源不同的DNA聚合酶同时检测相同大鼠DNA样本的结果显示,Multiplex PCR Kit、AmpliTaq Gold^(TM)360 DNA聚合酶、PlatinumⅡTaq热启动DNA聚合酶在第1~3组SNP位点均有扩增产物的电泳峰,其中PlatinumⅡTaq热启动DNA聚合酶在第4组SNP位点中少了一个扩增产物的电泳峰。另外,不同实验室间的比对结果显示,相同扩增体系的检测结果一致。结论基于多重PCR-LDR技术成功建立了一套覆盖所有常染色体与X染色体的大鼠SNP检测方案,该方法的稳定性和重复性俱佳。

Intravenous administration of glutathione protects parenchymal and non-parenchymal liver cells against reperfusion injury following rat liver transplantation

AIM:To investigate the effects of intravenous administration of the antioxidant glutathione (GSH) on reperfusion injury following liver transplantation. METHODS:Livers of male Lewis rats were transplanted after 24 h of hypothermic preservation in University of Wisconsin solution in a syngeneic setting.During a 2-h reperfusion period either saline (controls,n=8) or GSH (50 or 100 μmol/(h·kg),n=5 each) was continuously administered via the jugular vein. RESULTS:Two hours after starting reperfusion plasma ALT increased to 1 457±281 U/L (mean±SE) in controls but to only 908±187 U/L (P<0.05) in animals treated with 100 μmol GSH/(h·kg).No protection was conveyed by 50μmol GSH/(h·kg).Cytoprotection was confirmed by morphological findings on electron microscopy:GSH treatment prevented detachment of sinusoidal endothelial cells (SECs) as well as loss of microvilli and mitochondrial swelling of hepatocytes.Accordingly,postischemic bile flow increased 2-fold.Intravital fluorescence microscopy revealed a nearly complete restoration of sinusoidal blood flow and a significant reduction of leukocyte adherence to sinusoids and postsinusoidal venules.Following infusion of 50μmol and 100 μmol GSH/(h·kg),plasma GSH increased to 65±7 mol/L and 97±18 mol/L,but to only 20±3 mol/L in untreated recipients. Furthermore,plasma glutathione disulfide (GSSG) increased to 7.5±1.0 mol/L in animals treated with 100μmol/(h·kg) GSH but infusion of 50μmol GSH/(h·kg) did not raise levels of untreated controls (1.8±0.5 mol/L vs 2.2±0.2 mol/L). CONCLUSION:Plasma GSH levels above a critical level may act as a “sink” for ROS produced in the hepatic vasculature during reperfusion of liver grafts.Therefore,GSH can be considered a candidate antioxidant for the Drevention of reperfusion injury after liver transplantation,in particular since it has a low toxicity in humans.

Tetramethylpyrazine stimulates cystic fibrosis transmembrane conductance regulator-mediated anion secretion in distal colon of rodents

AIM： To investigate the effect of tetramethylpyrazine （TMP）, an active compound from Ligustium Wollichii Franchat, on electrolyte transport across the distal colon of rodents and the mechanism involved.METHODS： The short-circuit current （Isc） technique in conjunction with pharmacological agents and specific inhibitors were used in analyzing the electrolyte transport across the distal colon of rodents. The underlying cellular signaling mechanism was investigated by radioimmunoassay analysis （RIA） and a special mouse model of cystic fibrosis.RESULTS： IMP stimulated a conoentration-dependent rise in ISCl, which was dependent on both Cl^- and HCO3^-, and inhibited by apical application of diphenylamine-2,2＇-dicarboxylic acid （DPC） and glibenclamide, but resistant to 4,4＇-diisothiocyanatostilbene-2,2＇-disulfonic acid disodium salt hydrate （DIDS）. Removal of Na^＋ from basolateral solution almost completely abolished the Isc response to TMP, but it was insensitive to apical Na^＋ replacement or apical Na^＋ channel blocker, amiloride. Pretreatment of colonic mucosa with BAPTA-AM, a membrane-permeable selective Ca2＋ chelator, did not significantly alter the TMP-induced Iso No additive effect of forskolin and 3-isobutyl-l-methylxanthine （[BMX） was observed on the TMP-induced Isc, but it was significantly reduced by a protein kinase A inhibitor, H89.RIA results showed that TMP （1 mmol/L） elicited a significant increase in cellular cAMP production, which was similar to that elicited by the adenylate cyclase activator, forskolin （10μmol/L）. The TMP-elicited Isc as well as forskolin- or IBMX-induced Isc were abolished in mice with homozygous mutation of the cystic fibrosis transmembrane conductance regulator （CFTR） presenting defective CFTR functions and secretions.CONCLUSION： TMP may stimulate cAMP-dependent and CFTR-mediated Cl^- and HCO3^- secretion. This may have implications in the future development of alternative treatment for constipation.

The effect of adenovirus expressing wild-type p53 on 5-fluorouracil chemosensitivity is related to p53 status in pancreatic cancer cell lines

AIM:There are conflicting data about p53 function on cellular sensitivity to the cytotoxic action of 5-fluorouracil (5-FU). Therefore the objective of this study was to determine the combined effects of adenovirus-mediated wild-type (wt) p53 gene transfer and 5-FU chemotherapy on pancreatic cancer cells with different p53 gene status. METHODS:Human pancreatic cancer cell lines Capan-1^(p53mut), Capan-2^(p53wt),FAMPAC^(p53mut),PANC1^(p53mut),and rat pancreatic cancer cell lines AS^(p53wt) and DSL6A^(p53null) were used for in vitro studies.Following infection with different ratios of Ad- p53-particles (MOI) in combination with 5-FU,proliferation of tumor cells and apoptosis were quantified by cell proliferation assay (WST-1) and FACS (PI-staining).In addition,DSL6A syngeneic pancreatic tumor cells were inoculated subcutaneously in to Lewis rats for in vivo studies. Tumor size,apoptosis (TUNEL) and survival were determined. RESULTS:Ad-p53 gene transfer combined with 5-FU significantly inhibited tumor cell proliferation and substantially enhanced apoptosis in all four cell lines with an alteration in the p53 gene compared to those two cell lines containing wt-p53.In vivo experiments showed the most effective tumor regression in animals treated with Ad-p53 plus 5-FU.Both in vitro and in vivo analyses revealed that a sublethal dose of Ad-p53 augmented the apoptotic response induced by 5-FU. CONCLUSION:Our results suggest that Ad-p53 may synergistically enhance 5-FU-chemosensitivity most strikingly in pancreatic cancer cells lacking p53 function.These findings illustrate that the anticancer efficacy of this combination treatment is dependent on the p53 gene status of the target tumor cells.