MICRORNA REGULATION OF NEURITE OUTGROWTH AND NEURONAL REPAIR IN THE PERIPHERAL NERVOUS SYSTEM

MicroRNAs (miRNAs) are small non-coding RNAs that modulate gene expression and are increasingly recognized as critical regulators of all biological processes, including neuropathic pain and neuronal repair after injury. Injury-induced changes in miRNA expression suggest that these molecules coordinate complex molecular programs underlying axonal repair and regeneration. In this study, we investigated the role of a specific miRNA using a knockout (KO) mouse line combined with behavioural, anatomical, transcriptomic analyses following spared nerve injury (SNI) as well as ex vivo dorsal root ganglia (DRG) explant and in vitro neuronal outgrowth assessment. Sensorimotor testing revealed normal development of SNI-induced pain-like behaviours, whereas structural analysis showed impaired sciatic nerve fiber sprouting seven days after SNI. mRNA sequencing of KO DRG identified extensive alterations in gene networks associated with axonal growth, cytoskeletal dynamics, and chromatin regulation. Consistent with these findings, KO DRG explants and neurons exhibited reduced intrinsic outgrowth capacity. Together, these results indicate a selective role for this miRNA in axonal remodelling rather than nociceptive processes, highlighting its role as a regulator of regenerative pathways involved in peripheral nerve repair and neurite outgrowth. Future studies will investigate whether similar mechanisms regulate neurite outgrowth in other ganglia and assess the implications of this miRNA within the central nervous system. Defining these shared regulatory pathways may help clarify the broader role of miRNAs in neuronal growth and repair.