Abstract
Chondroitin sulfate proteoglycans (CSPGs) act as potent inhibitors of axonal growth and neuroplasticity after spinal cord injury (SCI). Here we reveal that CSPGs also play a critical role in preventing inflammation resolution by blocking the conversion of pro-inflammatory immune cells to a pro-repair phenotype in rodent models of SCI. We demonstrate that enzymatic digestion of CSPG glycosaminoglycans enhances immune cell clearance and reduces pro-inflammatory protein and gene expression profiles at key resolution time points. Analysis of phenotypically distinct immune cell clusters revealed CSPG-mediated modulation of macrophage and microglial subtypes which, together with T lymphocyte infiltration and composition changes, suggests a role for CSPGs in modulating both innate and adaptive immune responses after SCI. Mechanistically, CSPG activation of a pro-inflammatory phenotype in pro-repair immune cells was found to be TLR4-dependent, identifying TLR4 signalling as a key driver of CSPG-mediated immune modulation. These findings establish CSPGs as critical mediators of inflammation resolution failure after SCI in rodents, which leads to prolonged inflammatory pathology and irreversible tissue destruction.
| Original language | English |
|---|---|
| Article number | 2933 |
| Pages (from-to) | 1-23 |
| Number of pages | 23 |
| Journal | Nature Communications |
| Volume | 13 |
| Early online date | 25 May 2022 |
| DOIs | |
| Publication status | Published - 2022 |
Bibliographical note
Publisher Copyright:© 2022, The Author(s).
Funding
The work was supported by grants from the following organisations: the U.K. Medical Research Council (SNCF G1002055; ERA-NET NEURON MR/R005532/1) and the Rosetrees Trust (CF1\100006) to E.J.B.; the Fondo Europeo de Desarrollo Regional (FEDER)/Ministerio de Ciencia e Innovación—Agencia Estatal de Investigación “RTI2018-095872-B-C21/ERDF” (included in the FEDER programme for the Comunidad Valenciana 2014-2020) to V.M.M.; and Wings for Life Spinal Cord Research Foundation (WFL-UK-01/20 Project 214 to E.J.B.; WFL-NL-25/20 Project 238 to J.V.). We thank Dr. S. Akira (Osaka) and Dr C. Guerri for providing TLR4 mice. −/−
| Funders | Funder number |
|---|---|
| Medical Research Council | |
| Ministerio de Ciencia e Innovación | |
| Comunidad Valenciana 2014-2020 | |
| European Regional Development Fund | |
| SNCF | G1002055, ERA-NET NEURON MR/R005532/1 |
| Agencia Estatal de Investigación | RTI2018-095872-B-C21 |
| Rosetrees Trust | CF1\100006 |
| UK Research and Innovation | MR/R005532/1 |
| Wings for Life | WFL-UK-01/20 |