心肌细胞肥大过程中心脏发育相关转录因子及下游心脏肥大标志基因的时序性表达规律研究

目的观察在心肌细胞肥大过程中心脏发育相关转录因子及下游心脏肥大标志基因时序性表达规律,为心肌肥大机制研究提供线索。方法用异丙肾上腺素(ISO)干预心肌细胞,用CCK-8、细胞计数仪、免疫组化分别检测细胞存活率、细胞直径及表面积,用RT-PCR、Western blotting分别检测相关基因mRNA及蛋白表达水平。结果用ISO成功构建心肌细胞肥大模型。ISO干预后,GATA结合蛋白4(GATA4)、肌细胞增强因子2C(MEF2C)、GATA5、脑钠肽(BNP)、心房利钠因子(ANP)于24h开始升高,P300、α-肌球蛋白重链(α-MHC)、T-框蛋白5(TBX5)于12h开始升高,血清应答因子(SRF)、β-MHC mRNA于6h开始升高(P<0.05);其中GATA4、α-MHC、β-MHC、SRF、P300 mRNA表达呈先升后降的趋势,至干预72h GATA4、SRF、α-MHC、β-MHC、P300 mRNA表达仍高于正常(P<0.05),而MEF2C降至正常(P>0.05);GATA5、TBX5、ANP、BNP mRNA表达与对照组相比持续升高(P<0.05),而NKX2.5 mRNA(P>0.05)无明显变化。ISO干预48h后,GATA4蛋白表达水平升高,HEY2蛋白表达水平降低(P<0.05)。结论在心肌细胞肥大过程中,MEF2C的时序表达规律与心脏发育过程相似,而GATA4、GATA5、SRF、TBX5的时序性表达规律与心脏发育过程不完全一致,提示其在心肌细胞肥大由代偿转为失代偿过程中的重要作用。同时GATA4、MEF2C、SRF与乙酰化酶P300的时序性表达规律相似,提示在心肌细胞肥大过程中其时序性表达可能受P300调控。

丹参酮ⅡA抑制新生大鼠心肌细胞肥大的作用机制

目的本研究在原代培养的新生大鼠心肌细胞的基础上,观察丹参酮ⅡA磺酸钠盐(STS)对血管紧张肽Ⅱ(AngⅡ)诱导的心肌细胞肥大的影响,以探讨STS在钙调神经磷酸酶(CaN)依赖的信号通路心肌肥大中的作用。方法以培养的原代心肌细胞为模型,用AngⅡ刺激细胞外Ca2+内流,丹参酮ⅡA及钙离子拮抗剂维拉帕米(Ver)进行干预,检测心肌细胞[Ca2+]i及CaN活性;[3H]-亮氨酸掺入法测定心肌细胞蛋白质合成速率作为心肌细胞肥大的指标。用Western blot法检测心肌细胞CaN蛋白的表达,逆转录聚合酶链式反应(RT-PCR)检测心肌细胞原癌基因c-fos mRNA的表达。结果AngⅡ组[Ca2+]i水平、CaN蛋白的表达及蛋白核酸合成速率明显增高,与对照组相比差异显著(P<0.01),而STS能有效地降低由AngⅡ剌激引起的[Ca2+]i增高(P<0.01),明显抑制AngⅡ诱导的蛋白质合成速率的增加(P<0.01)。AngⅡ组CaN活性、蛋白表达以及c-fos mRNA的表达与对照组相比差异有显著性(P<0.05,P<0.01,P<0.01)。STS及维拉帕米抑制AngⅡ介导的心肌细胞CaN活性、蛋白表达以及c-fos mRNA表达的增高。结论CaN通路在AngⅡ刺激的心肌细胞肥大中起重要作用;STS具有Ca2+阻滞剂的特点,能有效降低由AngⅡ剌激引起的[Ca2+]i增高,降低CaN活性及其蛋白表达,从而降低c-fos mRNA的表达,抑制心肌肥大的发生和发展。

四磨汤对功能性排便障碍模型大鼠CRH、脑肠肽SP、及肥大细胞的干预作用

目的探讨功能性排便障碍(functional constipationnal disorder FC)发病的可能机制,并尝试解释中药四磨汤治疗功能性排便障碍的作用途径。方法 110只小鼠被随机分为6组:正常对照组,西药组,模型组,中药低剂量组,中药中剂量组,中药高剂量组。治疗2周后,测定各组大鼠的下丘脑部、脑干部位的肾上腺皮质激素释放因子(Corticotropin-releasing hormone,CRH)水平、脊髓腰段的P物质(substance P,SP)含量,采用免疫组化法观察肠粘膜肥大细胞活化状态(c-fos基因表达情况)及中药四磨汤对其影响。结果功能性排便障碍模型大鼠经四磨汤灌胃治疗2周后,与未用药的模型组相比,大鼠内脏的敏感性明显降低(P<0.05)。与正常组相比,功能性排便障碍模型组大鼠脑干部、下丘脑部位的CRH水平明显升高,大鼠脊髓腰段的SP含量降低,肠粘膜c-fos基因表达总阳性显色细胞数总数降低,两组比较P<0.05,差异具有统计学意义;与模型组相比,中药高、中、低剂量组、西药组大鼠脑干部、下丘脑的CRH水平均有所降低,大鼠脊髓腰段的SP含量升高,肠粘膜c-fos基因表达总阳性显色细胞数升高,两组间比较P<0.05,差异具有统计学意义。结论功能性排便障碍模型大鼠脑干、下丘脑CRH含量、脊髓P物质表达的改变提示与功能性排便障碍的发病相关。中药四磨汤能降低功能性排便障碍模型大鼠脑干、下丘脑CRH含量、升高脊髓P物质含量与c-fos基因表达水平,其作用机制可能是与影响脑肠轴通路有关。

黑色素及其相关基因的研究进展

黑色素对动物体色的形成起重要的作用。对黑色素的本质、功能以及生成机理做了全面的总结,并归纳了一些影响动物皮肤颜色和毛色的主要基因及其研究现状。

康泰复方对IBS模型大鼠脑肠轴CRH及肥大细胞的干预作用

目的:探讨肠易激综合征(IBS)的发病机制及康泰复方治疗IBS的作用途径。方法:SPF级SD大鼠110只,雌雄各半,随机分为模型组,康泰复方低、中、高剂量组以及西药组各20只,正常组10只;使用幼鼠母子分离加直肠刺激法复制大鼠IBS模型,造模后各用药组分别予以低、中、高剂量康泰复方以及马来酸曲美布汀片灌胃治疗,连续2周;检测大鼠内脏敏感性,大鼠模下丘脑、脑干促肾上腺皮质激素释放因子(CRH)水平,观测肠黏膜肥大细胞数目、肥大细胞c-fos基因表达情况。结果:造模后大鼠触发抬腹压力与正常组比较明显降低(P<0.05),康泰复方治疗后中、高剂量组与模型组比较压力升高(P<0.05),与正常组比较无显著性差异,而西药组与模型组比较无显著性差异;造模后模型组大鼠脑干、下丘脑CRH水平以及结肠远端肠黏膜肥大细胞c-fos基因表达与正常组比较明显升高(P<0.05),康泰复方中、高剂量组以及西药组与模型组比较,脑干、下丘脑CRH水平以及结肠远端肠黏膜肥大细胞c-fos基因表达均降低(P<0.05)。结论:IBS模型大鼠脑干、下丘脑CRH含量升高提示其改变与IBS的发病相关;中药康泰复方能降低IBS内脏高敏感性大鼠脑干、下丘脑CRH含量,其作用机制可能与影响脑肠轴CRH通路有关。

Efficacy of Antisense Oligodeoxynucleotide of Neuropeptide Y Y5 Receptor on Treating of Hyperleptinemia by Intraventricular Administration in Diet-induced Obese Rats

Objective: To study the efficacy of antisense oligonucleotide of neuropeptide Y (NPY) Y5 receptor on treating hyperleptinemia by intracerebral ventricular administration in diet-induced obese rats.Methods: The obese rats were prepared by feeding a high-nutritive diet for 7 weeks. The lateral ventricle of obese rats was cannulated. Either 10 μl of different neuropeptide Y Y5 receptor oligodeoxynucleotide, including antisense, sense and missense oligodeoxynucleotide (5 g/L) or 10 μl saline was administered into the ventricle through cannula three times per day in every rat. Two days later the rats were slaughtered .The weights of both retroperitoneal and epididymal adipose tissues were measured, and the serum insulin and leptin were detected by radioimmunoassay method and the murine leptin ELISA kit respectively. Results: ①The level of serum was significantly higher in experimental rats than that in normal rats. Similarly, the level of serum insulin and the weights of both retroperitoneal and epididymal adipose tissues were increased in experimental rats. ②After the diet-induced obese rats were intraventricularly administered with NPY Y5 receptor antisense oligodeoxynucleotide, the levels of serum leptin and insulin were significantly decreased and combined with the reduction of weight in retroperitoneal adipose tissue. There was, however, no significant difference in the weight of epidymal adipose tissue between pre-treated and post-treated duration. ③There was significant positive correlation among the level of serum leptin, the level of serum insulin and the weight of retroperritoneal adipose tissue in diet-induced obese rats. Conclusion: Intracerebral ventricular administration of antisense oligodeoxynucleotide of neuropeptide Y Y5 receptor may alleviate hyperleptinemia in diet-induced obese rats and decrease the weight of retroperitoneal adipose tissue and the level of serum insulin.

Applications of gene-chip for the detection of mutations in cTnI gene associated with FHCM

Mutations in cardiac troponin I （cTnI） gene were assessed based on gene-chip technology.Special probes were designed to fabricate the low-density gene-chip,which could detect the mutations in exons 3,5,7,and 8 of the cTnI gene simultaneously.For each exon,two oligonucleotide sequences labeled with fluorescein at the 5＇-end were designed,one （oligonucleotide Ⅰ） simulating the wild type and the other （oligonucleotide Ⅱ） simulating the mutant.Oligonucleotides Ⅰ and Ⅱ were mixed together to simulate the heterozygote.After optimizing the hybridization protocols,the fabricated gene-chip could detect the mutations in the exons of the cTnI gene with relative high sensitivity and specificity.The fully complementary probe gave a fluorescent signal almost 50% stronger than that of the one-base mismatched one,which is in accordance with the result from a theoretical estimate. An applicable special gene-chip is available to investigate and diagnose familial hypertrophic cardiomyopathy （FHCM） after further improvement.

Probiotic Lactobacillus rhamnosus downregulates FCER1 and HRH4 expression in human mast cells

AIM:To investigate the effects of four probiotic bacteria and their combination on human mast cell gene expression using microarray analysis.METHODS:Human peripheral-blood-derived mast cells were stimulated with Lactobacillus rhamnosus (L.rhamnosus) GG (LGG),L.rhamnosus Lc705 (Lc705),Propionibacterium freudenreichii ssp.shermanii JS (PJS) and Bifidobacterium animalis ssp.lactis Bb12 (Bb12) and their combination for 3 or 24 h,and were subjected to global microarray analysis using an Affymetrix GeneChip Human Genome U133 Plus 2.0 Array.The gene expression differences between unstimulated and bacteria-stimulated samples were further analyzed with GOrilla Gene Enrichment Analysis and Visualization Tool and MeV Multiexperiment Viewer-tool.RESULTS:LGG and Lc705 were observed to suppress genes that encoded allergy-related high-affinity IgE receptor subunits α and γ (FCER1A and FCER1G,respectively) and histamine H4 receptor.LGG,Lc705 and the combination of four probiotics had the strongest effect on the expression of genes involved in mast cell immune system regulation,and on several genes that encoded proteins with a pro-inflammatory impact,such as interleukin (IL)-8 and tumour necrosis factor alpha.Also genes that encoded proteins with anti-inflammatory functions,such as IL-10,were upregulated.CONCLUSION:Certain probiotic bacteria might diminish mast cell allergy-related activation by downregulation of the expression of high-affinity IgE and histamine receptor genes,and by inducing a pro-inflammatory response.

The Role of β3-adrenergic Receptor Gene in Neuropeptide Y Y5Receptor Antisense Gene Therapy of Diet-induced Obese Rats

Objective: To study the role of β3-adrenergic receptor gene in neuropeptide Y(NPY) Y5 receptor antisense gene therapy of diet-induced obese rats.Methods: The diet-induced obese rats were prepared by feeding a high-nutrition diet. Lateral ventricular was cannulated in obese rats which then received an intraventricular injection of either 5 μg/μl NPY Y5 receptor antisense or 10 μl missense oligodeoxynucleotide or saline of 10 μl respectively in every rat. When the rats were killed, the wet weight of abdominal adipose tissue, the level of serum lipid and lipoprotein were measured. Total RNA from the retroperitoneal adipose tissue was extracted and the level of β3-adrenergic receptor gene mRNA expression was evaluated by RT-PCR.Results: ①The wet weight of abdominal adipose tissue, the levels of serum lipids were greatly higher in diet-induced obese rats than those in normal rats. However, there were much lower β3-adrenergic receptor gene mRNA expression levels in retroperitoneal adipose tissue in diet-induced obese rats as compared with those in normal rats. ②After the diet-induced obese rats were intraventricularly administered with NPY Y5 receptor antisense oligodeoxynucleotide, the levels of β3-adrenergic receptor gene mRNA expression in retroperitoneal adipose tissue of diet-induced obese rats were strikingly up-regulated, whereas the wet weight of abdominal adipose tissue, the levels of serum lipids were markedly reduced.Conclusion: Intraventricular administration of antisense oligodeoxynucleotide to NPY Y5 receptor could significantly reduce the abdominal adipose tissue and the levels of serum lipids in diet-induced obese rats by up-regulating the level of β3-adrenergic receptor gene mRNA expression in retroperitoneal adipose tissue.

Calcineurin signalling mechanisms in myocardial hypertrophy

Calcineurin dephosphorylates multiple serine residues near the N terminus of NFAT proteins enabling them to translocate from cytoplasm to nucleus, where they activate a subset of hypertrophic response genes. Transgenic mice over-expressing a constitu- tively active form of calcineurin or NFAT3, developed obviously hypertrophy and heart failure or sudden death proving its pathogenic role. Here we used literatures on MEDLINE （2000-2011）, systematically reviewed the new development of calcineurin signaling pathway in myocardial hypertrophy

血管紧张素转换酶抑制剂致干咳机制的研究进展

干咳是血管紧张素转换酶抑制剂类药物一种常见的不良反应,对患者的服药依从性和生活质量具有一定的影响。女性较男性更易发生,除此之外未发现更特异的环境变量或行为因素可以解释该不良反应的发生。基础研究提示其发生机制可能涉及激肽系统、花生四烯酸通路等。已有的少数候选基因研究主要涉及血管紧张素转换酶基因和缓激肽β_2受体基因等,但未得到一致的关联结果。今后的候选基因研究应该注意考虑基因与基因间、同一基因中不同变异位点间、以及性别与基因表达间的交互作用对干咳发生的影响。