Abstract:
Interstitial cells of Cajal (ICC) and PDGFRα+ cells regulate smooth muscle motility in the gastrointestinal (GI) tract. However, their role(s) in esophageal motility are still unclear. The mouse esophagus has traditionally been described as almost entirely skeletal muscle in nature though ICC have been identified along its entire length. The current study evaluated the distribution of skeletal and smooth muscle within the esophagus using a mouse selectively expressing eGFP in smooth muscle cells (SMCs). The relationship of SMCs to ICC and PDGFRα+ cells was also examined. SMCs declined in density in the oral direction however SMCs represented ~ 25% of the area in the distal esophagus suggesting a likeness to the transition zone observed in humans. ANO1+ intramuscular ICC (ICC-IM) were distributed along the length of the esophagus though like SMCs, declined proximally. ICC-IM were closely associated with SMCs but were also found in regions devoid of SMCs. Intramuscular and submucosal PDGFRα+ cells were densely distributed throughout the esophagus though only intramuscular PDGFRα+ cells within the LES and distal esophagus highly expressed SK3. ICC-IM and PDGFRα+ cells were closely associated with nNOS+, VIP+, VAChT+ and TH+ neurons throughout the LES and distal esophagus. GFAP+ cells resembling intramuscular enteric glia were observed within the muscle and were closely associated with ICC-IM and PDGFRα+ cells, occupying a similar location to c. These data suggest that the mouse esophagus is more similar to the human than thought previously and thus set the foundation for future functional and molecular studies using transgenic mice.
摘要:
Cajal间质细胞(ICC)和PDGFRα细胞调节胃肠道(GI)中的平滑肌运动。然而,它们在食管运动中的作用尚不清楚。小鼠食道传统上被描述为本质上几乎完全是骨骼肌,尽管ICC已经沿其整个长度被鉴定。本研究使用在平滑肌细胞(SMC)中选择性表达eGFP的小鼠评估了食管内骨骼肌和平滑肌的分布。还检查了SMC与ICC和PDGFRα+细胞的关系。SMC的密度在口腔方向上下降,但是SMC占食道远端区域的约25%,这表明与人类观察到的过渡区相似。ANO1+肌内ICC(ICC-IM)沿食管长度分布,但与SMC相似,向近端下降。ICC-IM与SMC密切相关,但也存在于缺乏SMC的地区。肌内和粘膜下PDGFRα细胞在整个食道中密集分布,尽管LES和远端食道中只有肌内PDGFRα细胞高度表达SK3。ICC-IM和PDGFRα+细胞与nNOS+密切相关,VIP+,整个LES和远端食管的VAChT+和TH+神经元。在肌肉中观察到类似于肌内肠胶质细胞的GFAP细胞,并且与ICC-IM和PDGFRα细胞密切相关,占据与运动神经纤维相似的位置。这些数据表明,小鼠食道比以前认为的更类似于人类,因此为将来使用转基因小鼠进行功能和分子研究奠定了基础。