Sergeant Gerard P, Large Roddy J, Beckett Elizabeth A H, McGeough Cathrine M, Ward Sean M, Horowitz Burton
Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada 89557-0046, USA.
Physiol Genomics. 2002 Oct 2;11(1):1-9. doi: 10.1152/physiolgenomics.00052.2002.
Interstitial cells of Cajal (ICC) have been identified in specific areas throughout the smooth musculature of the gastrointestinal (GI) tract. Located within the circular and longitudinal muscle layers of the gastric fundus lies a specific type of ICC, termed "intramuscular" ICC or IC-IM. The principal function of this cell type is to act as "mediators of excitatory and inhibitory enteric neurotransmission." The functional role of these cells has been investigated using W/W(v) mutant mice that specifically lack IC-IM, resulting in disrupted enteric neurotransmission. The aim of the present study was to investigate differential gene expression in W/W(v) mutant mice, from the tunica muscularis of the gastric fundus using a mouse cDNA microarray containing 1,081 known genes. Verification of the microarray data was attained using real-time "quantitative" PCR (qPCR). Of the 1,081 arrayed genes, 36 demonstrated differential expression by >2-fold in the W/W(v) mice. An agreement rate of 50% (7 of 14 tested) was obtained using qPCR. Of the seven confirmed changes in expression, several were indicative of a supersensitive phenotype, observed in denervation models. Expression of several putative neurotransmitter receptors including P2Y, the receptor for the inhibitory neurotransmitter ATP, was upregulated. The functional role of the P2Y receptor was also investigated using electrophysiological recordings. These results offer a new insight into the molecular changes that occur in W/W(v) fundic smooth muscle and may also provide novel information with regard to the importance of IC-IM in enteric neurotransmission.
在胃肠道（GI）平滑肌的特定区域已鉴定出 Cajal 间质细胞（ICC）。胃底环行肌层和纵行肌层内存在一种特定类型的 ICC，称为“肌内”ICC 或 IC-IM。这种细胞类型的主要功能是充当“兴奋性和抑制性肠神经传递的介质”。已使用特异性缺乏 IC-IM 的 W/W(v)突变小鼠来研究这些细胞的功能作用，这导致肠神经传递中断。本研究的目的是使用包含 1,081 个已知基因的小鼠 cDNA 微阵列，研究 W/W(v)突变小鼠胃底肌层的差异基因表达。通过实时“定量”PCR（qPCR）对微阵列数据进行验证。在 1,081 个阵列基因中，有 36 个在 W/W(v)小鼠中的表达差异>2 倍。使用 qPCR 获得了 50%（14 个测试中有 7 个）的一致率。在七个确认的表达变化中，有几个表明在去神经模型中观察到的超敏表型。包括 P2Y（抑制性神经递质 ATP 的受体）在内的几种假定神经递质受体的表达上调。还使用电生理记录研究了 P2Y 受体的功能作用。这些结果为 W/W(v)胃底平滑肌中发生的分子变化提供了新的见解，也可能为 IC-IM 在肠神经传递中的重要性提供新的信息。
