miR-4792 regulates inflammatory responses in Cryptococcus neoformans-infected microglia

Abstract

Investigating the factors that influence the inflammatory response of microglial cells is crucial for understanding the pathogenesis of cryptococcal meningitis (CM). MicroRNAs (miRNAs/miRs) play an important role in inducing host defenses and activating the immune response during microbial infection; however, the regulatory mechanisms of miRNAs in cryptococcal meningitis remain poorly defined. In a previous study, the authors assessed the miRNA profiles of THP-1 (human acute monocytic leukemia cells) cells following Cryptococcus neoformans (C. neoformans) infection. In the present study, it was found that miR-4792 expression was downregulated in BV2 cells infected with C. neoformans, whilst that of its target gene, epidermal growth factor receptor (EGFR), was upregulated. Infected cells in which miR-4792 was overexpressed exhibited a decreased EGFR transcript expression, reduced mitogen-activated protein kinase (MAPK) signaling and a decreased secretion of inflammatory cytokines. In addition, following antifungal treatment in patients with cryptococcal meningitis, the levels of miR-4792 in the cerebrospinal fluid significantly increased, whilst the expression of EGFR significantly decreased. In addition, receiver operator characteristic analysis revealed miR-4792 (AUCROC=0.75) and EGFR (AUCROC=0.79) as potential diagnostic markers in patients with cryptococcal meningitis.