Smooth muscle cell-specific TMEM16A deletion does not alter Ca2+ signaling, uterine contraction, gestation length, or litter size in mice†
Smooth muscle cell-specific TMEM16A deletion does not alter Ca2+ signaling, uterine contraction, gestation length, or litter size in mice†
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DOI：
10.1093/biolre/ioz096
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发表时间：
2019-06
影响因子：
3.6
通讯作者：
Mingzi Qu;P. Lu;Karl Bellve;K. Fogarty;Lawrence M. Lifshitz;F. Shi;R. Zhuge
中科院分区：
文献类型：
--
作者：
Mingzi Qu;P. Lu;Karl Bellve;K. Fogarty;Lawrence M. Lifshitz;F. Shi;R. Zhuge
摘要子宫肌层细胞中的离子通道在月经周期、妊娠维持和分娩过程中的自发和激动剂诱导的子宫收缩中起着关键作用;因此，识别这些细胞中离子通道的基因并确定其作用对于理解生殖生物学是必不可少的。以前的研究与体外功能和药理学方法产生了有争议的结果TMEM 16 A钙激活的氯离子通道在子宫肌层细胞的存在和作用。为了明确地确定该通道在这些细胞中的功能，我们采用了一种遗传方法，通过使用平滑肌细胞特异性TMEM 16 A缺失（即TMEM 16 ASMKO）小鼠。我们发现，TMEM 16 ASMKO小鼠的子宫肌层细胞在KCl、催产素和PGF 2 α刺激后产生的Ca 2+信号模式和幅度与同基因对照子宫肌层细胞相同。在子宫组织水平，TMEM 16 A缺失也未引起自发或激动剂（即KCl、催产素和PGF 2 α）诱导的收缩的可检测变化。此外，在体内，TMEM 16 ASMKO小鼠以与遗传上相同的对照小鼠相同的窝仔数足月分娩。最后，在对照和TMEM 16 ASMKO小鼠中的TMEM 16 A免疫染色显示，该蛋白在子宫内膜基质中高度表达，但不与平滑肌特异性标志物MYH 11共定位。总的来说，这些结果明确地证明TMEM 16 A不作为自发子宫收缩的起搏通道，也不作为激动剂诱发的子宫收缩的去极化通道。然而，这两种功能可能是TMEM 16 ASMKO小鼠正常妊娠期长度和窝仔数的基础。TMEM 16 A在子宫肌层细胞中不存在，并且对小鼠的Ca 2+信号传导、收缩反应和妊娠没有影响。
Abstract Ion channels in myometrial cells play critical roles in spontaneous and agonist-induced uterine contraction during the menstrual cycle, pregnancy maintenance, and parturition; thus, identifying the genes of ion channels in these cells and determining their roles are essential to understanding the biology of reproduction. Previous studies with in vitro functional and pharmacological approaches have produced controversial results regarding the presence and role of TMEM16A Ca2+-activated Cl– channels in myometrial cells. To unambiguously determine the function of this channel in these cells, we employed a genetic approach by using smooth muscle cell-specific TMEM16A deletion (i.e. TMEM16ASMKO) mice. We found that myometrial cells from TMEM16ASMKO mice generated the same pattern and magnitude in Ca2+ signals upon stimulation with KCl, oxytocin, and PGF2α compared to the isogenic control myometrial cells. At the uterine tissue level, TMEM16A deletion also did not cause detectable changes in either spontaneous or agonist (i.e. KCl, oxytocin, and PGF2α)-induced contractions. Moreover, in vivo the TMEM16ASMKO mice gave birth at full term with the same litter size as genetically identical control mice. Finally, TMEM16A immunostaining in both control and TMEM16ASMKO mice revealed that this protein was highly expressed in the endometrial stroma, but did not co-localize with a smooth muscle specific marker MYH11. Collectively, these results unequivocally demonstrate that TMEM16A does not serve as a pacemaking channel for spontaneous uterine contraction, neither does it function as a depolarizing channel for agonist-evoked uterine contraction. Yet these two functions could underlie the normal gestation length and litter size in the TMEM16ASMKO mice. Summary Sentence The TMEM16A is absent in myometrial cells and exerts no impact on Ca2+ signaling, contractile responses and pregnancy in mice.