Real-Time PCR Platform RPT09A, Laboratory of Molecular Virology and Parasitology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
Laboratory of Biology of the Interactions, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
PLoS Negl Trop Dis. 2023 Mar 27;17(3):e0011223. doi: 10.1371/journal.pntd.0011223. eCollection 2023 Mar.
Chronic Chagas cardiomyopathy (CCC) is one of the leading causes of morbidity and mortality due to cardiovascular disorders in endemic areas of Chagas disease (CD), a neglected tropical illness caused by the protozoan parasite Trypanosoma cruzi. CCC is characterized by parasite persistence and inflammatory response in the heart tissue, which occur parallel to microRNA (miRNA) alterations. Here, we investigated the miRNA transcriptome profiling in the cardiac tissue of chronically T. cruzi-infected mice treated with a suboptimal dose of benznidazole (Bz), the immunomodulator pentoxifylline alone (PTX), or the combination of both (Bz+PTX), following the CCC onset. At 150 days post-infection, Bz, PTX, and Bz+PTX treatment regimens improved electrocardiographic alterations, reducing the percentage of mice afflicted by sinus arrhythmia and second-degree atrioventricular block (AVB2) when compared with the vehicle-treated animals. miRNA Transcriptome profiling revealed considerable changes in the differential expression of miRNAs in the Bz and Bz+PTX treatment groups compared with the control (infected, vehicle-treated) group. The latter showed pathways related to organismal abnormalities, cellular development, skeletal muscle development, cardiac enlargement, and fibrosis, likely associated with CCC. Bz-Treated mice exhibited 68 differentially expressed miRNAs related to signaling pathways like cell cycle, cell death and survival, tissue morphology, and connective tissue function. Finally, the Bz+PTX-treated group revealed 58 differentially expressed miRNAs associated with key signaling pathways related to cellular growth and proliferation, tissue development, cardiac fibrosis, damage, and necrosis/cell death. The T. cruzi-induced upregulation of miR-146b-5p, previously shown in acutely infected mice and in vitro T. cruzi-infected cardiomyocytes, was reversed upon Bz and Bz+PTX treatment regimens when further experimentally validated. Our results further our understanding of molecular pathways related to CCC progression and evaluation of treatment response. Moreover, the differentially expressed miRNAs may serve as drug targets, associated molecular therapy, or biomarkers of treatment outcomes.
慢性恰加斯心肌病（CCC）是导致恰加斯病（CD）流行地区心血管疾病发病率和死亡率的主要原因之一，CD 是一种由原生动物寄生虫克氏锥虫引起的被忽视的热带病。CCC 的特征是寄生虫在心脏组织中的持续存在和炎症反应，这与 microRNA（miRNA）的改变同时发生。在这里，我们研究了慢性 T. cruzi 感染的小鼠心脏组织中的 miRNA 转录组谱，这些小鼠在 CCC 发病后接受了低剂量苯硝唑（Bz）、免疫调节剂己酮可可碱（PTX）单独治疗（PTX）或两者联合治疗（Bz+PTX）。在感染后 150 天，与 vehicle 处理的动物相比，Bz、PTX 和 Bz+PTX 治疗方案改善了心电图改变，降低了患有窦性心律失常和二度房室传导阻滞（AVB2）的小鼠比例。miRNA 转录组谱分析显示，与对照组（感染、vehicle 处理）相比，Bz 和 Bz+PTX 治疗组的 miRNA 表达差异有显著变化。后者显示与机体异常、细胞发育、骨骼肌发育、心脏增大和纤维化相关的途径，可能与 CCC 有关。Bz 处理的小鼠表现出 68 个与细胞周期、细胞死亡和存活、组织形态和结缔组织功能等信号通路相关的差异表达 miRNA。最后，Bz+PTX 处理组显示 58 个与细胞生长和增殖、组织发育、心脏纤维化、损伤和坏死/细胞死亡等关键信号通路相关的差异表达 miRNA。先前在急性感染的小鼠和体外 T. cruzi 感染的心肌细胞中已经显示 T. cruzi 诱导的 miR-146b-5p 上调，在 Bz 和 Bz+PTX 治疗方案中得到了逆转，进一步实验验证。我们的研究结果进一步加深了我们对与 CCC 进展相关的分子途径的理解，并评估了治疗反应。此外，差异表达的 miRNA 可作为药物靶点，与分子治疗或治疗结果的生物标志物相关。
