Patritti-Cram, J. | Search bioRxiv

bioRxiv2023

Schwann cells modulate nociception in neurofibromatosis 1

Pain of unknown etiology is frequent in individuals with the tumor predisposition syndrome Neurofibromatosis 1 (NF1), even when tumors are absent. Schwann cells (SC) were recently shown to play roles in nociceptive processing, and we find that chemogenetic activation of SCs is sufficient to induce afferent and behavioral mechanical hypersensitivity in mice. In mouse models, animals show afferent and behavioral hypersensitivity when SC, but not neurons, lack Nf1. Importantly, hypersensitivity corresponds with SC-specific upregulation of mRNA encoding glial cell line derived neurotrophic factor (GDNF), independent of the presence of tumors. Neuropathic pain-like behaviors in the NF1 mice were inhibited by either chemogenetic silencing of SC calcium or by systemic delivery of GDNF targeting antibodies. Together, these findings suggest that Nf1 loss in SCs causes mechanical pain by influencing adjacent neurons and, data may identify cell-specific treatment strategies to ameliorate pain in individuals with NF1. Graphical AbstractGDNF released from Schwann cells acts on sensory neurons leading to mechanical hypersensitivity and pain-like behaviors in preclinical models of NF1. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=181 SRC="FIGDIR/small/533004v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@d17177org.highwire.dtl.DTLVardef@706f56org.highwire.dtl.DTLVardef@19db1ccorg.highwire.dtl.DTLVardef@3e28d_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2021

Purinergic receptor P2RY14 cAMP signaling regulates EGFR-driven Schwann cell precursor self-renewal and nerve tumor initiation in neurofibromatosis.

Neurofibromatosis type 1 (NF1) is a genetic disorder characterized by nerve tumors called neurofibromas, in which Schwann cells (SCs) lack NF1 and show deregulated RAS signaling. NF1 is also implicated in regulation of cAMP. Gene expression profiling and protein expression identified P2RY14 in SCs and SC precursors (SCPs) implicating P2RY14 as a candidate upstream regulator of cAMP in EGF-dependent SCP. We found that SCP self-renewal was reduced by genetic or pharmacological inhibition of P2RY14. In NF1 deficient SCs and malignant peripheral nerve sheath tumor (MPNST) cells, P2RY14 inhibition decreased EGFR-driven phospho-Akt and increased cAMP signaling. In a neurofibroma mouse model, genetic deletion of P2RY14 increased mouse survival, delayed neurofibroma initiation and rescued cAMP signaling. Conversely, elevation of cAMP diminished SCP number in vitro and diminished SC proliferation in neurofibroma bearing mice in vivo. These studies identify the purinergic receptor P2RY14 as a critical G-protein-coupled receptor (GPCR) in NF1 mutant SCPs and SCs and suggest roles for EGFR-GPCR crosstalk in facilitating SCP self-renewal and neurofibroma initiation via cAMP and EGFR-driven phospho-Akt.

neuroscience↗