A shed form of LDL receptor-related protein-1 regulates peripheral nerve injury and neuropathic pain in rodents.
J Clin Invest
; 118(1): 161-72, 2008 Jan.
Article
em En
| MEDLINE
| ID: mdl-18060043
ABSTRACT
Injury to the peripheral nervous system (PNS) initiates a response controlled by multiple extracellular mediators, many of which contribute to the development of neuropathic pain. Schwann cells in an injured nerve demonstrate increased expression of LDL receptor-related protein-1 (LRP1), an endocytic receptor for diverse ligands and a cell survival factor. Here we report that a fragment of LRP1, in which a soluble or shed form of LRP1 with an intact alpha-chain (sLRP-alpha), was shed by Schwann cells in vitro and in the PNS after injury. Injection of purified sLRP-alpha into mouse sciatic nerves prior to chronic constriction injury (CCI) inhibited p38 MAPK activation (P-p38) and decreased expression of TNF-alpha and IL-1beta locally. sLRP-alpha also inhibited CCI-induced spontaneous neuropathic pain and decreased inflammatory cytokine expression in the spinal dorsal horn, where neuropathic pain processing occurs. In cultures of Schwann cells, astrocytes, and microglia, sLRP-alpha inhibited TNF-alpha-induced activation of p38 MAPK and ERK/MAPK. The activity of sLRP-alpha did not involve TNF-alpha binding, but rather glial cell preconditioning, so that the subsequent response to TNF-alpha was inhibited. Our results show that sLRP-alpha is biologically active and may attenuate neuropathic pain. In the PNS, the function of LRP1 may reflect the integrated activities of the membrane-anchored and shed forms of LRP1.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Dor
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Nervo Isquiático
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Sistema de Sinalização das MAP Quinases
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Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade
Limite:
Animals
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Humans
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Male
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article