Extended maturation of the HD10.6 immortalised human dorsal root ganglion cell line enables modelling of nociceptive responses and neural injury

Human sensory neuron models are an important resource for studying pain mechanisms and axon injury and repair. Current systems are limited by accessibility, scalability, or incomplete functional maturation. The HD10.6 human dorsal root ganglion-derived immortalised cell line represents a promising alternative; however, its maturation trajectory and suitability for disease modelling remain incompletely defined.

Here, we performed a longitudinal, multi-modal characterisation of HD10.6 cells during differentiation over 28 days. Bulk RNA sequencing revealed progressive transcriptional remodelling, with temporal up-regulation of neuronal and nociceptor-associated gene programmes, including ion channels implicated in pain signalling. Protein-level analyses confirmed increased expression of key nociceptor markers and neuropeptides, including TRPV1, Nav1.7, Nav1.8 and CGRP.

Functional assays demonstrated the emergence of sensory neuron-like properties over time. Calcium imaging revealed increasing responsiveness to capsaicin, allyl isothiocyanate, α,β-MeATP, and prostaglandin E2, while patch-clamp electrophysiology at DIV 21 after maturation showed repetitive firing of action potential and, most importantly, exhibited TTX-Resistant sodium currents. These findings establish a temporal relationship between transcriptional changes and functional competence.

Finally, we evaluated the utility of HD10.6 neurons for modelling axon degeneration. Treatment with vacor-induced robust neurite degeneration, which was attenuated by pharmacological inhibition of SARM1, demonstrating engagement of conserved axon degeneration pathways.

Together, our findings define the progressive maturation of HD10.6 sensory neurons and establish this system as a scalable human platform for studying nociceptor biology and SARM1-dependent axon degeneration.