Qian J, Hendrix M, Larsen W J, Dorn G W, Lessard J L
Division of Developmental Biology, Children's Hospital Medical Center, Cincinnati, Ohio 45229-3039, USA.
Mol Reprod Dev. 1997 Jul;47(3):284-94. doi: 10.1002/(SICI)1098-2795(199707)47:3<284::AID-MRD7>3.0.CO;2-H.
A novel smooth muscle/myometrial-like cell line, SMU1-10, has been generated from the uterus of a H-2Kb-tsA58 transgenic mouse carrying a thermolabile SV40 large T-antigen gene. These cells grow continuously when maintained at the permissive temperature (33 degrees C) for the SV40 large T-antigen but stop dividing when placed at the non-permissive temperature (39 degrees C) and ultimately die within 3 weeks. All of the SMU1-10 cells produce smooth muscle alpha-actin (SMAA) at both 33 degrees C and 39 degrees C. A subset of the cells also contain smooth muscle gamma-actin (SMGA), a hallmark of smooth muscle differentiation, and the fraction of cells staining for this actin increases from about 1% when maintained for three days at 33 degrees C to as much as 30% at 39 degrees C over the same length of time. However, the appearance of SMGA in SMU1-10 cells appears to be regulated mainly at a post-transcriptional level since in situ hybridization indicates that all cells contain SMGA mRNA at both 33 degrees C and 39 degrees C. SMU1-10 cultures also contain smooth muscle myosin heavy chain (SM-MHC) and SM22 alpha, both of which are only found in smooth muscle of the adult mouse. Three additional smooth muscle (myometrium)-related markers, connexin 43, the thromboxane A2 receptor, and the progesterone receptor also are present in these cells. At the nonpermissive temperature for SV40 large T-antigen, the both level of SMGA mRNA and the number of cells staining for this actin are significantly increased in the presence of progesterone, a process that is similar to the upregulation of SMGA in the myometrium late in pregnancy. Overall, SMU1-10 cells provides a potentially useful in vitro model system to study smooth muscle/myometrial differentiation.
一种新的平滑肌/子宫肌层样细胞系SMU1-10，是从携带温度敏感型SV40大T抗原基因的H-2Kb-tsA58转基因小鼠的子宫中产生的。当在SV40大T抗原的允许温度（33℃）下培养时，这些细胞持续生长，但置于非允许温度（39℃）时停止分裂，并最终在3周内死亡。所有SMU1-10细胞在33℃和39℃时均产生平滑肌α-肌动蛋白（SMAA）。一部分细胞还含有平滑肌γ-肌动蛋白（SMGA），这是平滑肌分化的一个标志，在相同时间内，在33℃维持三天时，染色为这种肌动蛋白的细胞比例约为1%，而在39℃时可高达30%。然而，SMU1-10细胞中SMGA的出现似乎主要在转录后水平受到调控，因为原位杂交表明所有细胞在33℃和39℃时均含有SMGA mRNA。SMU1-10培养物中还含有平滑肌肌球蛋白重链（SM-MHC）和SM22α，这两者仅在成年小鼠的平滑肌中发现。另外三个与平滑肌（子宫肌层）相关的标志物，连接蛋白43、血栓素A2受体和孕激素受体也存在于这些细胞中。在SV40大T抗原的非允许温度下，在孕激素存在的情况下，SMGA mRNA水平和染色为这种肌动蛋白的细胞数量均显著增加，这一过程类似于妊娠后期子宫肌层中SMGA的上调。总体而言，SMU1-10细胞为研究平滑肌/子宫肌层分化提供了一个潜在有用的体外模型系统。
