Khan I, Blennerhassett M G, Kataeva G V, Collins S M
Department of Medicine, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada.
Gastroenterology. 1995 Jun;108(6):1720-8. doi: 10.1016/0016-5085(95)90133-7.
BACKGROUND/AIMS: The increased expression of several cytokines, including interleukin 6 (IL-6), has recently been reported in a study of the longitudinal muscle and myenteric plexus layers of rat intestine following Trichinella spiralis infection. However, the putative cellular sources and the mechanism underlying the induction of IL-6 in these tissues are presently unknown. The aim of this study was to examine the ability of cultured smooth muscle cells from rat jejunum to produce IL-6 messenger RNA and protein and to investigate the underlying mechanism.
Cultured smooth muscle cells were treated with human recombinant interleukin 1 beta (HrIL-1 beta). The level of IL-6 messenger RNA was estimated by polymerase chain reaction, and the released IL-6 protein was estimated by bioassay.
HrIL-1 beta induced IL-6 messenger RNA expression in the smooth muscle cells in a time- and concentration-dependent manner. This was accompanied by the secretion of IL-6 protein into the medium. The effect of HrIL-1 beta was blocked by the IL-1 receptor antagonist, by actinomycin D, or by prior boiling of the cytokine.
These findings show that HrIL-1 beta interacts with its receptor on smooth muscle cells to induce transcription of the IL-6 gene and to cause the secretion of IL-6. These results indicate that intestinal smooth muscle cells are not only targets for but also a source of cytokine.
背景/目的：最近在一项关于旋毛虫感染后大鼠肠道纵肌层和肌间神经丛层的研究中报道了包括白细胞介素6（IL-6）在内的几种细胞因子表达增加。然而，这些组织中IL-6的假定细胞来源及其诱导机制目前尚不清楚。本研究的目的是检测大鼠空肠培养的平滑肌细胞产生IL-6信使核糖核酸和蛋白质的能力，并研究其潜在机制。
用重组人白细胞介素1β（HrIL-1β）处理培养的平滑肌细胞。通过聚合酶链反应评估IL-6信使核糖核酸水平，通过生物测定法评估释放的IL-6蛋白。
HrIL-1β以时间和浓度依赖性方式诱导平滑肌细胞中IL-6信使核糖核酸表达。这伴随着IL-6蛋白分泌到培养基中。IL-1受体拮抗剂、放线菌素D或预先煮沸细胞因子可阻断HrIL-1β的作用。
这些发现表明，HrIL-1β与其在平滑肌细胞上的受体相互作用，诱导IL-6基因转录并导致IL-6分泌。这些结果表明，肠道平滑肌细胞不仅是细胞因子的作用靶点，也是细胞因子的来源。
