Functional evidence of hsa-miR-21-5p and hsa-miR-3158-3p in regulating immune pathways relevant to cerebral malaria.

backgroundCerebral malaria (CM), the most severe manifestation of Plasmodium falciparum infection, is characterized by immune dysregulation, endothelial dysfunction, and brain injury. MicroRNAs (miRNAs) have emerged as promising biomarkers and regulators of malaria pathogenesis. Previous clinical studies identified elevated plasma levels of hsa-miR-21-5p and hsa-miR-3158-3p as correlates of CM severity and poor outcomes. However, their mechanistic roles in modulating host immune responses remain poorly defined.

methodsTo elucidate the regulatory effects of these miRNAs, MCF7 and HepG2 cell lines were transfected with synthetic mimics of hsa-miR-21-5p or hsa-miR-3158-3p. Following 48 h of incubation, mRNA expression levels of key immune-related genes-NF-κB, CD46, THBS1, TNF-α, IL-1β, IL-2, IL-6, IL-8, IL-10, and TLR4-were quantified using SYBR Green-based RT-qPCR. Relative expression levels were calculated using the 2⁻ΔΔCt method and statistically compared with negative control and non-transfected groups.

resultsCells transfected with the hsa-miR-3158-3p mimic exhibited a significant downregulation of NF-κB expression compared with both control groups (p < 0.05). Similarly, transfection with the hsa-miR-21-5p mimic led to significant reductions in NF-κB, IL-10, and TLR4 expression (p < 0.05). No significant alterations were observed in the other immune-related targets examined.

conclusionsThese findings suggest that hsa-miR-21-5p and hsa-miR-3158-3p may regulate immune pathways implicated in CM, providing a mechanistic basis for future validation in disease-relevant models.