Molecular Signatures of Proliferation and Maturation in Oligodendrocyte Precursor Cells Following High-Rate Mechanical Trauma

Abstract

Mild traumatic brain injury (mTBI), clinically defined as concussion, is a prevalent public health challenge affecting individuals across all demographics. While mTBI commonly results from falls, collisions, and vehicular accidents in the general population, athletes and military personnel face disproportionately elevated risk due to the repetitive high-impact nature of their activities. Diagnosis remains a significant challenge, as mTBI often lacks overt clinical indicators such as loss of consciousness or structural damage detectable by standard neuroimaging. This challenge is further exemplified in blast-induced TBI (bTBI), where exposure to explosive-generated blast waves produce complex injury patterns. In military personnel and civilians in conflict zones, where chronic neuropsychiatric sequelae such as PTSD, depression, and cognitive impairment frequently emerge before the injury is clinically recognized. The absence of effective therapeutic interventions reflects a fundamental gap in our understanding of its heterogeneous pathophysiology, injury biomechanics, and complex cellular and molecular responses associated with mTBI. Glial cells have recently gained recognition as compelling therapeutic targets, owing to their indispensable roles in maintaining cerebral homeostasis and modulating neuronal function. Among these, oligodendrocyte precursor cells (OPCs), are of particular interest given their remyelination capacity — a critical but inherently limited regenerative process in the adult brain. OPC-mediated tissue recovery encompasses lesion-directed migration, proliferation, and differentiation into mature oligodendrocytes, collectively supporting the restoration of neuronal function in the context of neurodegeneration and tissue loss. However, these mechanisms governing the OPC response to mTBI remain poorly characterized, representing a critical gap in the field. To elucidate the cellular and molecular mechanisms underlying OPC responses to mechanical injury, a Shock Wave Generator (SWG) system was utilized to generate high-rate mechanical insult replicating key features of preclinical blast-induced TBI. OPCs were encapsulated within a norbornene-modified hyaluronic acid (NorHA) hydrogel, establishing a three-dimensional culture platform that enables physiologically relevant transmission of mechanical force and recapitulates intracranial pressure dynamics observed in preclinical models. In OPC monoculture, mechanical insult acutely upregulated proliferation-associated gene expression (PDGFRA) while downregulating maturation-associated protein (GALC) expression. Comprehensive proteomic analysis identified widespread dysregulation with bioinformatic interrogation revealed disruption of signaling pathways governing oligodendrocyte differentiation and myelination. To incorporate neuroinflammatory conditions, microglia were introduced into a co-culture system. Notably, the presence of microglial substantially attenuated injury-induced dysregulation of OPC proliferation and maturation markers (GPR17 and GALC). Collectively, these findings establish that OPCs are intrinsically susceptible to high-rate mechanical insult, while microglial interactions exert a regulatory influence that mitigates molecular dysregulation. This foundational study advances our mechanistic understanding of glial responses to mechanical injury and provides a critical framework for future investigations into OPC-targeted regenerative and therapeutic strategies.