Brainbow示踪小鼠心肌细胞增殖中他莫昔芬最适标记剂量的探究  

Exploring optimal tamoxifen labeling dose in myocardial cell prolifera⁃tion using Brainbow tracing mice

作　　者：高洋洋 高佳[2] 孙萌[2] 王睿[2] GAO Yangyang;GAO Jia;SUN Meng;WANG Rui(First Clinical Medical College of Shanxi Medical University,Taiyuan 030001,China;The First Hospital of Shanxi Medi-cal University,Taiyuan 030001,China)

机构地区：[1]山西医科大学第一临床医学院,山西太原0300001 [2]山西医科大学第一医院,山西太原0300001

出　　处：《中国病理生理杂志》2024年第6期1147-1152,共6页Chinese Journal of Pathophysiology

基　　金：山西省基础研究计划第二批项目(No.08722)。

摘　　要：目的:运用Brainbow 2.1小鼠进行心肌细胞谱系追踪,探讨用于心肌细胞增殖标记的最适他莫昔芬剂量。方法:采用4周龄的Brainbowfl/+;Myh6-MerCreMe+小鼠,通过腹腔注射的方式给予3个不同剂量(3、9和27 mg/kg)的他莫昔芬诱导Cre重组酶表达,使心肌细胞标上特定的颜色,4周后取材染色,共聚焦显微镜下定量不同剂量的他莫昔芬标记的心肌细胞数量,以及被标记的细胞中单个细胞、临近的2个细胞簇和临近的3个及以上细胞簇的比例。选择合适剂量(9 mg/kg)的他莫昔芬标记Brainbow小鼠,对比假手术组与心肌梗死(MI)模型组心肌细胞增殖情况。结果:(1)注射9 mg/kg的他莫昔芬后标记的单个细胞比例为99.13%±0.03%,临近的2个细胞簇比例为0.82%±0.09%,3个及以上细胞簇比例为0.05%±0.01%。3 mg/kg组标记总数较少;27 mg/kg组出现明显克隆扩增富集。(2)用9 mg/kg的他莫昔芬标记心肌细胞后,MI小鼠2个细胞簇和3个及以上细胞簇标记比例较假手术组均显著升高(P<0.01),MI后心肌细胞增殖比例增加。结论:9 mg/kg他莫昔芬标记的临近心肌细胞簇的比例更接近生理状态下的心肌细胞增殖比例,因此9 mg/kg为示踪心肌细胞增殖的最适他莫昔芬剂量。AIM:This study employs Brainbow 2.1 mice to trace myocardial cell lineage and investigates the optimal dose of tamoxifen for labeling proliferating myocardial cells.METHODS:Four-week-old Brainbowfl/+;Myh6-Mer‐CreMer+mice were administered tamoxifen at three different doses(3,9 and 27 mg/kg)via intraperitoneal injection to induce Cre recombinase expression and label myocardial cells with specific colors.Four weeks later,the samples were stained,and the number of myocardial cells labeled with varying doses of tamoxifen was quantified under confocal microscope.This quantification included the proportion of individually labeled cells,adjacent clusters of two cells,and clusters of three or more cells.An appropriate dose(9 mg/kg)of tamoxifen for labeling Brainbow mice was selected to compare myocardial cell proliferation between sham and myocardial infarction(MI)model groups.RESULTS:(1)After 9 mg/kg tamoxifen injection,the proportion of individually labeled cells was 99.13%±0.03%,that of adjacent 2-cell clusters was 0.82%±0.09%,and that of≥3-cell clusters was 0.05%±0.01%.The 3 mg/kg group had fewer total labeled cells,while the 27 mg/kg group showed significant clonal expansion and enrichment.(2)After labeling myocardial cells with 9 mg/kg tamoxifen,the MI mice showed increased proportions of 2-cell and≥3-cell clusters compared with sham group(P<0.01),indicating an increase in myocardial cell proliferation after MI.CONCLUSION:The proportion of adjacent myocardial cell clusters labeled with 9 mg/kg tamoxifen more closely approximates the physiological myocardial cell proliferation rate,indicating 9 mg/kg as the most suitable tamoxifen dose for tracing myocardial cell proliferation.

关 键 词：Brainbow小鼠 心肌细胞 细胞增殖 他莫昔芬 荧光标记 

分 类 号：R541[医药卫生—心血管疾病] R-331[医药卫生—内科学] R363[医药卫生—临床医学]