Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Immuno-Biochemistry Lab, Immunology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
J Cell Biochem. 2019 Sep;120(9):15746-15755. doi: 10.1002/jcb.28844. Epub 2019 May 8.
Inflammatory bowel disease (IBD) is one of the most important immune-mediated disorders of the gastrointestinal tract. Besides, IBD is associated with numerous extraintestinal complications such as venous thromboembolism (VTE), an important risk factor for vascular complications, which results in the increased morbidity and mortality. The JAK2 (Janus kinase 2) V617F mutation is a well-known point mutation which is involved in the pathogenesis of IBD, and VTE. Therefore, the aims of this study were to evaluate expression of JAK2 and association of V617F mutation in JAK2 of Iranian patients with IBD.
Two hundred and forty-six patients with IBD (209 UC and 37 CD) and 206 healthy controls were enrolled in this study. The genomic DNA and total RNA were extracted from peripheral blood mononuclear cells (PBMCs). Then, the JAK2 V617F mutation detection was performed using the restriction fragment length polymorphism (RFLP) method. In addition, the JAK2 mRNA expression was evaluated using a quantitative polymerase chain reaction (q-PCR) using the SYBR Green assay.
There was no association of V61F mutation in patients with IBD with or without thrombosis compared with healthy control. However, the relative mRNA expression of JAK2 was significantly upregulated in patients with IBD in comparison with healthy control (P < 0.0001). In addition, the JAK2 mRNA expression was significantly decreased in patients with IBD having thrombosis compared with those without thrombosis ( P < 0.0001).
Taken together our findings suggested that JAK2 V61F-independent upregulation of JAK2 mRNA expression in patients with IBD. Moreover, despite the absence of JAK2 V617F mutation in patients with IBD, the increased gene expression of JAK2 can be explained by another molecular mechanism such as regulation of gene expression at the transcriptional level which may play crucial roles in the pathogenesis of IBD.
炎症性肠病（IBD）是胃肠道最重要的免疫介导疾病之一。此外，IBD 与许多肠道外并发症相关，如静脉血栓栓塞症（VTE），这是血管并发症的一个重要危险因素，导致发病率和死亡率增加。JAK2（Janus 激酶 2）V617F 突变是一种众所周知的点突变，参与 IBD 和 VTE 的发病机制。因此，本研究旨在评估伊朗 IBD 患者 JAK2 中的 JAK2 和 V617F 突变的表达及其相关性。
本研究纳入了 246 名 IBD 患者（209 名 UC 和 37 名 CD）和 206 名健康对照者。从外周血单核细胞（PBMCs）中提取基因组 DNA 和总 RNA。然后，使用限制性片段长度多态性（RFLP）方法检测 JAK2 V617F 突变。此外，使用 SYBR Green 法通过定量聚合酶链反应（q-PCR）评估 JAK2 mRNA 的表达。
与健康对照组相比，无论是否发生血栓形成，IBD 患者中 V61F 突变与血栓形成均无相关性。然而，与健康对照组相比，IBD 患者的 JAK2 相对 mRNA 表达显著上调（P<0.0001）。此外，与无血栓形成的患者相比，有血栓形成的 IBD 患者的 JAK2 mRNA 表达显著降低（P<0.0001）。
总之，我们的研究结果表明，IBD 患者 JAK2 V61F 独立的 JAK2 mRNA 表达上调。此外，尽管 IBD 患者中不存在 JAK2 V617F 突变，但 JAK2 基因表达的增加可以用另一种分子机制来解释，如转录水平的基因表达调控，这可能在 IBD 的发病机制中发挥关键作用。
