Keywords
host–pathogen interactions
CX3CL1
RT-qPCR
post-infection
Abstract
Background: Trypanosoma cruzi, the etiological agent of Chagas disease, is associated with chronic cardiac complications, including fibrosis and cardiomyopathy. Cardiac fibroblasts play a central role in myocardial remodeling. PIWI-interacting RNAs (piRNAs), a class of small non-coding RNAs, are emerging regulators of gene expression; however, their role in host–pathogen interactions and cardiac fibrosis remains poorly understood.
Objectives: To evaluate alterations in piRNA expression in primary human cardiac fibroblasts (PHCF) following T. cruzi infection and to identify potential piRNA-mediated regulatory networks involved in early pathogenic mechanisms.
Methods: PHCF were infected with T. cruzi (Tulahuen strain), and RNA was extracted at 1-, 3-, and 6-hours post-infection. High-throughput RNA sequencing was performed using the BGISEQ-500 platform. Differential expression analysis was conducted using NOISeq (fold change ≥2). Target gene prediction was performed using the miRanda algorithm. Selected genes were validated using RT-qPCR, and interaction networks were analyzed using GeneMANIA.
Results: A total of 441 piRNAs were differentially expressed during early infection, with the majority being upregulated. Many of these were novel piRNAs. Predicted targets included key genes involved in inflammation and fibrosis, such as ICAM1, SMAD2, CXCR2, CX3CL1, and EGR1. RT-qPCR validation demonstrated dynamic expression changes, including downregulation of ICAM1 and time-dependent modulation of CX3CL1 and EGR1. Network analysis revealed involvement of TGF-β signaling and chemokine pathways, suggesting a role in cardiac remodelling.
Conclusion: cruzi infection significantly dysregulates piRNA expression in cardiac fibroblasts. These findings highlight a novel layer of post-transcriptional regulation that may contribute to inflammation and fibrosis, offering potential targets for therapeutic intervention in Chagas cardiomyopathy.