Swedish Nerve Growth Factor Mutation (NGFR100W) Defines a Role for TrkA and p75NTR in Nociception
Authors: Sung Kijung , Ferrari Luiz F. , Yang Wanlin , Chung ChiHye , Zhao Xiaobei , Gu Yingli , Lin Suzhen , Zhang Kai , Cui Bianxiao , Pearn Matthew L. , Maloney Michael T. , Mobley William C. , Levine Jon D. , Wu Chengbiao 
Published: February 2018

AbstractNerve growth factor (NGF) exerts multiple functions on target neurons throughout development. The recent discovery of a point mutation leading to a change from arginine to tryptophan at residue 100 in the mature NGFβ sequence (NGFR100W) in patients with hereditary sensory and autonomic neuropathy, type V (HSAN V), made it possible to distinguish the signaling mechanisms that lead to two functionally different outcomes of NGF: trophic versus nociceptive. We performed extensive biochemical, cellular and live imaging experiments to examine the binding and signaling properties of NGFR100W. Our results show that, similar to the wildtype NGF (wtNGF), the naturally occurring NGFR100Wmutant was capable of binding to and activating the TrkA receptor and its downstream signaling pathways to support neuronal survival and differentiation. However, NGFR100Wfailed to bind and stimulate the 75kD neurotrophic factor receptor (p75NTR)-mediated signaling cascades (i.e. the RhoA-Cofilin pathway). Intraplantar injection of NGFR100Winto adult rats induced neither TrkA-mediated thermal nor mechanical acute hyperalgesia, but retained the ability to induce chronic hyperalgesia based on agonism for TrkA signaling. Taken together, our studies provide evidence that NGFR100Wretains trophic support capability through TrkA and one aspect of its nociceptive signaling, but fails to engage p75NTRsignaling pathways. Our findings suggest that wtNGF acts through TrkA to regulate the delayed priming of nociceptive responses. The integration of both TrkA and p75NTRsignaling thus appears to regulate neuroplastic effects of NGF in peripheral nociception.Significance StatementIn the present study, we characterized the naturally occurring NGFR100Wmutant that is associated with hereditary sensory and autonomic neuropathy, type V. We have demonstrated for the first time that NGFR100Wretains trophic support capability through TrkA but fails to engage p75NTRsignaling pathways. Furthermore, following Intraplantar injection into adult rats, NGFR100Winduced neither thermal nor mechanical acute hyperalgesia, but retained the ability to induce chronic hyperalgesia. We have also provided evidence that the integration of both TrkA-and p75NTR-mediated signaling thus appears to regulate neuroplastic effects of NGF in peripheral nociception. Our study with NGFR100Wsuggests that it is possible to uncouple trophic effect from nociceptive function, both induced by wildtype NGF.AbbreviationsNGFnerve growth factor;NGFR100WNGF mutation with a change from tryptophan (W) to arginine (R) at the 100 residue.TrkATropomyosin receptor kinase A;p75NTRthe 75kD neurotrophic factor receptor;HSAN Vhereditary sensory and autonomic neuropathy, type V;BFCNbasal forebrain cholinergic neurons;PNSperipheral nervous system;CNScentral nervous system;BDNFbrain-derived neurotrophic factor;NTneurotrophin;TrkBTropomyosin receptor kinase B;TrkCTropomyosin receptor kinase C;RhoARas homolog gene family, member A;NF-κBnuclear factor kappa B;AktProtein kinase B;JNKc-Jun N-terminal kinases;ADAlzheimer’s disease;CSFcerebrospinal fluid;HIVhuman immunodeficiency virusCIPAcongenital insensitivity to pain with anhidrosis;ERKextracellular signal-related kinase;PI3Kphosphatidylinositol 3-kinase;PLCγand phospholipase Cγ;PGE2Prostaglandin E2;PCRpolymerase chain reaction;GFPgreen fluorescent protein;QDquantum dots;HEK293FTHuman embryonic kidney 293FT cell line;KKENGF mutant protein with mutation at:K32A/K34A/E35A in the mature sequence;Δ9/13NGF mutant protein with deletion of N-terminal 9-13 residues in the mature sequence;DMEMDulbecco’s Modified Eagle’s Medium;PMSFphenylmethylsulfonyl fluoride;SDS-PAGEsodium dodecyl sulfate polyacrylamide gel electrophoresis;DMSOdimethyl sulfoxide;ASanti-sense oligos;MMmis-matched oligos;E15.5 DRGembryonic day 15.5 dorsal root ganglion;ECDextracellular domain;MEMMinimum Essential Medium;TIRFTotal Internal Reflection Fluorescence;EMCCDelectron multiplying charge-coupled device;PC12a cell line derived from a pheochromocytoma of the rat adrenal medulla;BSABovine Serum Albumin;PBSphosphate buffered saline;IgGImmunoglobulin G;DICDays In Culture;