Effects of lipopolysaccharide-induced inflammation on the interstitial cells of Cajal
Effects of lipopolysaccharide-induced inflammation on the interstitial cells of Cajal
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DOI：
10.1007/s00441-013-1775-7
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发表时间：
2014-01
影响因子：
3.6
通讯作者：
Jia Wei;Ning Li;Xue Xia;Xuyong Chen;Fei Peng;G. Besner;Jiexiong Feng
中科院分区：
文献类型：
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作者：
Jia Wei;Ning Li;Xue Xia;Xuyong Chen;Fei Peng;G. Besner;Jiexiong Feng
Cajal间质细胞（ICC）最近被发现显示表型变化。本研究旨在确定ICC是否发生与炎症微环境相关的表型变化，以及ICC表型是否可以在炎症刺激停止后恢复。免疫组织化学研究显示，与对照组（n= 12）相比，先天性巨结肠患者（n= 34）的功能性ICC标记物c-kit显著减少，而另一种ICC标记物CD 34则没有显著改变。与溶剂组（n= 6）相比，腹腔注射脂多糖（LPS; 1.5 mg/kg）的小鼠（n= 6）显著诱导血浆肿瘤坏死因子-α（TNF-α）水平，通过酶联免疫吸附试验测定。Western blot和实时荧光定量PCR检测进一步显示LPS注射显著抑制肠c-kit蛋白和mRNA的表达，其可被Toll样受体4（TLR 4）缺陷（n= 6）而不是TLR 2缺陷（n= 6）阻断，并且对CD 34无影响。与溶剂组（n= 6）相比，腹腔注射TNF-α（30 μg/kg）（n= 6）也显著降低了肠道c-kit蛋白和mRNA水平，但未降低CD 34水平。TNF-α诱导的c-kit活性降低不受TLR 4缺陷的抑制（n= 6）。TNF-α停药7 d后，肠c-kit蛋白和mRNA水平明显恢复。此外，免疫荧光分析进一步证实，TNF-α暴露24 h可抑制c-kit表达，停止TNF-α暴露后c-kit表达可恢复。暴露于TNF-α后，CD 34表达没有改变。因此，ICC的表型变化发生在肠道的炎症微环境中，LPS、TLR 4和TNFα对这一过程至关重要。
Interstitial cells of Cajal (ICC) have recently been found to display phenotypic changes. The present study is designed to determine whether phenotypic changes occur in ICC associated with an inflammatory microenvironment and whether the ICC phenotype could be recovered after the discontinuation of inflammatory stimuli. Immunohistochemistry studies revealed that the functional ICC marker, c-kit, was markedly reduced in patients with Hirschsprung’s disease (n= 34) compared with controls (n= 12), whereas another marker of ICC, CD34, was not altered significantly. Compared with the vehicle group (n= 6), intraperitoneal injection of lipopolysaccharide (LPS; 1.5 mg/kg) in mice (n= 6) significantly induced plasma tumor necrosis factor-alpha (TNF-α) levels as determined by enzyme-linked immunosorbent assay. Western blot and real-time polymerase chain reaction assessment further showed that LPS injection markedly suppressed intestinal c-kit protein and mRNA expression, which could be blocked by Toll-like receptor 4 (TLR4) deficiency (n= 6) rather than TLR2 deficiency (n= 6) and had no effects on CD34. Compared with the vehicle group (n= 6), intraperitoneal TNF-α (30 μg/kg) administration (n= 6) also significantly reduced intestinal c-kit protein and mRNA levels but not CD34 levels. However, the reduction of c-kit induced by TNF-α injection was not suppressed by TLR4 deficiency (n= 6). Intestinal c-kit protein and mRNA levels were markedly restored after the discontinuation of TNF-α administration for 7 days. Moreover, immunofluorescence analysis of primary ICC further confirmed that exposure to TNF-α for 24 h suppressed c-kit expression, which could be restored after discontinuation of TNF-α exposure. CD34 expression was not altered upon exposure to TNF-α. Thus, phenotypic changes in ICC occur in an inflammatory microenvironment in the gut and LPS, TLR4 and TNFα are crucial to this process.