Format

Send to

Choose Destination
Pain. 2019 Jan;160(1):224-236. doi: 10.1097/j.pain.0000000000001394.

Exploring the transcriptome of resident spinal microglia after collagen antibody-induced arthritis.

Author information

1
Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
2
Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom.
3
Rheumatology Unit, Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
4
Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.

Abstract

Recent studies have suggested a sexually dimorphic role of spinal glial cells in the maintenance of mechanical hypersensitivity in rodent models of chronic pain. We have used the collagen antibody-induced arthritis (CAIA) mouse model to examine differences between males and females in the context of spinal regulation of arthritis-induced pain. We have focused on the late phase of this model when joint inflammation has resolved, but mechanical hypersensitivity persists. Although the intensity of substance P, calcitonin gene-related peptide, and galanin immunoreactivity in the spinal cord was not different from controls, the intensity of microglia (Iba-1) and astrocyte (glial fibrillary acidic protein) markers was elevated in both males and females. Intrathecal administration of the glial inhibitors minocycline and pentoxifylline reversed mechanical thresholds in male, but not in female mice. We isolated resident microglia from the lumbar dorsal horns and observed a significantly lower number of microglial cells in females by flow cytometry analysis. However, although genome-wide RNA sequencing results pointed to several transcriptional differences between male and female microglia, no convincing differences were identified between control and CAIA groups. Taken together, these findings suggest that there are subtle sex differences in microglial expression profiles independent of arthritis. Our experiments failed to identify the underlying mRNA correlates of microglial actions in the late phase of the CAIA model. It is likely that transcriptional changes are either subtle and highly localised and therefore difficult to identify with bulk isolation techniques or that other factors, such as changes in protein expression or epigenetic modifications, are at play.

PMID:
30247264
PMCID:
PMC6319583
DOI:
10.1097/j.pain.0000000000001394
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wolters Kluwer Icon for PubMed Central
Loading ...
Support Center