Gupta S K, Fitzgerald J F, Chong S K, Croffie J M, Garcia J G
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, USA.
Am J Gastroenterol. 1998 May;93(5):795-8. doi: 10.1111/j.1572-0241.1998.227_a.x.
Increasing evidence suggests that nitric oxide participates in the pathophysiology of intestinal barrier function/dysfunction and inflammation. Increases in inducible nitric oxide synthase (iNOS) mRNA and protein expression have been observed in colonic mucosal biopsies of adults with inflammatory bowel disease (IBD). It is unclear whether iNOS induction is specific for IBD or a reflection of nonspecific mucosal inflammation. Furthermore, the characteristics of iNOS mRNA expression in pediatric patients with gastrointestinal disorders remains ill-defined. Our objective was to examine the relationship between iNOS mRNA expression and gastrointestinal mucosal inflammation in a pediatric population.
Esophageal and colonic mucosal biopsies were obtained during endoscopy. Total RNA was isolated from these biopsies and reverse transcription-polymerase chain reaction (RT-PCR) performed (35 PCR cycles) using two 20-bp primers that amplified a predicted 372-bp conserved iNOS mRNA fragment.
Biopsies were obtained from 29 children (22 boys; mean age 10.6 yr [range 1.7-16.5 yr]). Endoscopic and histological findings included normal esophageal mucosa (n = 3), esophagitis (n = 10), normal rectal mucosa (n = 2), ulcerative colitis (n = 10), and Crohn disease (n = 4). Evidence of iNOS mRNA was detected by PCR amplification in six of 10 patients with ulcerative colitis and in two of four patients with Crohn disease. However, iNOS mRNA was not amplified in any esophageal biopsy or in rectal mucosa biopsies with normal histology.
These data indicate that upregulation of iNOS mRNA expression in colonic mucosa is a feature of IBD in children. iNOS mRNA expression is not upregulated in esophageal mucosa or in the absence of colonic inflammation. Further studies designed to determine the site- and cell-specificity of iNOS mRNA upregulation in mucosal biopsies from children with IBD may further illuminate the pathophysiology of these disorders.
越来越多的证据表明，一氧化氮参与肠道屏障功能/功能障碍及炎症的病理生理过程。在患有炎症性肠病（IBD）的成年患者的结肠黏膜活检中，已观察到诱导型一氧化氮合酶（iNOS）mRNA和蛋白表达增加。目前尚不清楚iNOS的诱导是IBD所特有的，还是非特异性黏膜炎症的一种反映。此外，患有胃肠道疾病的儿科患者中iNOS mRNA表达的特征仍不明确。我们的目的是研究儿科人群中iNOS mRNA表达与胃肠道黏膜炎症之间的关系。
在内镜检查过程中获取食管和结肠黏膜活检样本。从这些活检样本中分离出总RNA，并使用两条20个碱基对的引物进行逆转录-聚合酶链反应（RT-PCR）（35个PCR循环），这两条引物可扩增出一个预测的372个碱基对的保守iNOS mRNA片段。
从29名儿童（22名男孩；平均年龄10.6岁[范围1.7 - 16.5岁]）获取了活检样本。内镜和组织学检查结果包括正常食管黏膜（n = 3）、食管炎（n = 10）、正常直肠黏膜（n = 2）、溃疡性结肠炎（n = 10）和克罗恩病（n = 4）。通过PCR扩增在10例溃疡性结肠炎患者中的6例以及4例克罗恩病患者中的2例中检测到iNOS mRNA的证据。然而，在任何食管活检样本或组织学正常的直肠黏膜活检样本中均未扩增出iNOS mRNA。
这些数据表明，结肠黏膜中iNOS mRNA表达上调是儿童IBD的一个特征。在食管黏膜或无结肠炎症的情况下，iNOS mRNA表达不会上调。旨在确定IBD患儿黏膜活检中iNOS mRNA上调的位点和细胞特异性的进一步研究，可能会进一步阐明这些疾病的病理生理学。
