骨髓增殖性肿瘤(MPNs)是一类恶性血液病，但心血管事件是主要死因。JAK2V617F突变是MPNs发生的重要机制。我们的前期研究显示JAK2V617F转基因鼠心脏肥大的机制是成纤维细胞功能异常，属于远距离调控。有研究发现miR-143表达与JAK2V617F突变率及临床表型正相关，且miR-143能够调控基质金属蛋白酶(MMPs)的功能。外泌体是传递microRNA信号分子的介质。因此JAK2V617F转基因小鼠骨髓细胞可能通过外泌体转运miR-143至心脏，抑制MMPs功能，引起成纤维细胞功能异常导致心脏肥大。本项目通过原位杂交和PCR检测外泌体中miR-143表达；慢病毒介导miR-143-inhibitor研究miR-143在转基因小鼠心脏肥大中的作用；体内外实验论证外泌体转运miR-143对MMPs活性及心肌的影响。本项目成功实施将为MPNs及其并发症的防治提供新靶点。

Myeloproliferative neoplasms (MPNs) represent a range of incurable haematological malignancies, but the mortality of MPNs can be reduced by retarding and decreasing the patients’ cardiovascular complications. The mutation of JAK2V617F is an important molecular mechanism in the pathogenesis of MPNs. Our early research showed the cardiac hypertrophy in JAK2V617F mice were caused by abnormal matrix protein synthesis and degradation in fibroblasts, and that belonged to the remote control. Recently, some research found that MiR-143 expression was positively related to JAK2V617F and MPNs clinical phenotype, and miR-143 could regulate the expression and activation of matrix metalloproteinase (MMPs). The exosome is an important medium to transfer microRNA signal molecules in regulating function of cardiac fibroblast. Therefore, we put forward the hypothesis that in JAK2V617F transgenic mice，tumor cells in bone marrow secret and transship miR-143 by exosomes to cardiac fibroblast to regulate the activity of MMPs, promote fibroblasts proliferation and collagen secretion, and then mediated cardiac hypertrophy. In order to prove the hypothesis, firstly, the expressions of miR-143 in exosomes will be detected by in situ hybridization and Real-time PCR. Secondly, we will test the effect of miR-143-inhibitor on cardiac hypertrophy mediated by lentivirus to demonstrate the role of miR-143 on cardiac hypertrophy in JAK2V617F transgenic mice. Lastly, we will confirm the role of exosomes transshipping miR-143 to cardiac fibroblast on inhibition of MMPs activity, promoting fibroblasts proliferation, collagen secretion and cardiac hypertrophy in vivo and in vitro. The successful implementation of the project will provide new ideas and new targets for prevention and treatment of MPNs and relative complications.