Cre-recombinase (CRB) over-expressed mouse driven by a different promoter is normally used for conditional gene inactivation in various *** specificity of this conditional knockout tool is dependent on its promoter lo...
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Cre-recombinase (CRB) over-expressed mouse driven by a different promoter is normally used for conditional gene inactivation in various *** specificity of this conditional knockout tool is dependent on its promoter located at the up-stream of CRB gene.A transgenic mouse MHC-CRB is the myocardial-specific Cre mouse controlled by the cardiac a myosin heavy chain promoter, which commonly used for myocardial-specific conditional removal of gene of ***, the toxic effect of expression of the Cre recombinase has been reported that can induce intro-chromosome rearrangements, micronuclei formation and other forms of DNA damages.
Purpose: To examine caloric expenditure of more than 1,000 kcal per week was meaningful for controlling coronary artery disease risks in female older ***:Older female adults were recruited from Senior Welfare Center i...
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Purpose: To examine caloric expenditure of more than 1,000 kcal per week was meaningful for controlling coronary artery disease risks in female older ***:Older female adults were recruited from Senior Welfare Center in *** had them be hooked up with portable calorimeter from morning till they went to bed for a *** on the average caloric expenditure subjects were divided into two groups: those who expended more than 1,000kcal per week, or expended less than 1,000kcal per week aerobic functional capacity (VO2peak) and CAD risk factors were compared between two groups.
目的:心肌细胞损失及再生不足可导致心功能不全、心律失常和心脏衰竭,而心肌细胞修复和补充对损伤心脏功能恢复意义重大。心肌干(祖)细胞增殖和分化是心脏修复再生的基础,Isl1+细胞是目前研究最多的心脏祖细胞(CPCs),具有定向分化为心肌细胞、内皮细胞和平滑肌细胞系的潜能。我们前期综述表明,Isl1协同多基因共同调节心脏发育。适宜运动负荷可生理性刺激心脏肥大和心肌细胞增殖,但这种内源性生理过程的分子机制知之甚少。本文主要研究示踪有氧运动对Isl1+心肌祖细胞及其分化的影响。方法:利用成簇规律间隔短回文重复序列系统(CRISPR-Cas9),将受他莫昔芬调控的CreERT2基因定点插入小鼠Isl1基因启动子下游,使CreERT2表达受控于Isl1基因启动子。将CreERT2基因敲入小鼠与Rosa26-lacZ小鼠交配,获得Isl1-CreERT(KI)/Rosa26-1acZ+双杂合小鼠,用于示踪Isl1表达的心肌祖细胞的增殖和分化。将双杂合小鼠繁育扩群,取雄性小鼠进行有氧运动实验。采用4周小动物跑台运动,运动强度参照Bedford训练模型标准,对照组正常笼内生活,不运动。运动后测量心脏体重比、心率、心脏射血分数等生理指标,以及real time PCR和X-gal染色等检测示踪有氧运动对Isl1+心肌祖细胞及其分化。结果:经基因型鉴定、组织表达谱测定和lacZ染色、冰冻切片和石蜡切片,从基因和蛋白水平证实,基因敲入小鼠CreERT2表达在成年小鼠心脏窦房结、心脏神经节、主动脉弓和肺动脉根部,成功建立了CreERT2基因敲入小鼠模型。经4周有氧运动小鼠心脏重量和心系数明显高于对照组(P<0.01,P<0.05),收缩末左室后壁厚度(LVPWs)显著增加(P<0.01),心脏射血分数(EF%)和心室短轴缩短率(FS%)增加(P<0.05)。real time PCR、lacZ染色和免疫荧光实验正在进行中,后续结果有待证实。结论:建立了研究心肌祖细胞增殖和谱系示踪模型。有氧运动可刺激心脏肥大和心脏功能增加,是否能够促进Isl1+心肌祖细胞增殖及分化有待研究。
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