Targeting the β2-integrin LFA-1, reduces adverse neuroimmune actions in neuropathic susceptibility caused by prenatal alcohol exposure | Acta Neuropathologica Communications | Full Text

Targeting the β2-integrin LFA-1, reduces adverse neuroimmune actions in neuropathic susceptibility caused by prenatal alcohol exposure | Acta Neuropathologica Communications | Full Text



Acta Neuropathologica Communications

Targeting the β2-integrin LFA-1, reduces adverse neuroimmune actions in neuropathic susceptibility caused by prenatal alcohol exposure

• Joshua J. Sanchez,
• Jacob E. Sanchez,
• Shahani Noor,
• Chaselyn D. Ruffaner-Hanson,
• Suzy Davies,
• Carston R. Wagner,
• Lauren L. Jantzie,
• Nikolaos Mellios,
• Daniel D. Savage and
• Erin D. MilliganEmail author

Acta Neuropathologica Communications20197:54

https://doi.org/10.1186/s40478-019-0701-y

©  The Author(s). 2019

• Received: 16 January 2019
• Accepted: 16 March 2019
• Published: 8 April 2019

Abstract

Recently, moderate prenatal alcohol exposure (PAE) was shown to be a risk factor for peripheral neuropathy following minor nerve injury. This effect coincides with elevated spinal cord astrocyte activation and ex vivo immune cell reactivity assessed by proinflammatory cytokine interleukin (IL) -1β protein expression. Additionally, the β2-integrin adhesion molecule, lymphocyte function-associated antigen-1 (LFA-1), a factor that influences the expression of the proinflammatory/anti-inflammatory cytokine network is upregulated. Here, we examine whether PAE increases the proinflammatory immune environment at specific anatomical sites critical in the pain pathway of chronic sciatic neuropathy; the damaged sciatic nerve (SCN), the dorsal root ganglia (DRG), and the spinal cord. Additionally, we examine whether inhibiting LFA-1 or IL-1β actions in the spinal cord (intrathecal; i.t., route) could alleviate chronic neuropathic pain and reduce spinal and DRG glial activation markers, proinflammatory cytokines, and elevate anti-inflammatory cytokines. Results show that blocking the actions of spinal LFA-1 using BIRT-377 abolishes allodynia in PAE rats with sciatic neuropathy (CCI) of a 10 or 28-day duration. This effect is observed (utilizing immunohistochemistry; IHC, with microscopy analysis and protein quantification) in parallel with reduced spinal glial activation, IL-1β and TNFα expression. DRG from PAE rats with neuropathy reveal significant increases in satellite glial activation and IL-1β, while IL-10 immunoreactivity is reduced by half in PAE rats under basal and neuropathic conditions. Further, blocking spinal IL-1β with i.t. IL-1RA transiently abolishes allodynia in PAE rats, suggesting that IL-1β is in part, necessary for the susceptibility of adult-onset peripheral neuropathy caused by PAE. Chemokine mRNA analyses from SCN, DRG and spinal cord reveal that increased CCL2 occurs following CCI injury regardless of PAE and BIRT-377 treatment. These data demonstrate that PAE creates dysregulated proinflammatory IL-1β and TNFα /IL-10 responses to minor injury in the sciatic-DRG-spinal pain pathway. PAE creates a risk for developing peripheral neuropathies, and LFA-1 may be a novel therapeutic target for controlling dysregulated neuroimmune actions as a consequence of PAE.

Keywords

• Neuropathic pain
• Prenatal alcohol exposure
• Glia
• Neuroimmune function
• Peripheral immune system
• Spinal cord