TY - JOUR
T1 - Large-scale chondroitin sulfate proteoglycan digestion with chondroitinase gene therapy leads to reduced pathology and modulates macrophage phenotype following spinal cord contusion injury
AU - Bartus, Katalin
AU - James, Nicholas D
AU - Didangelos, Athanasios
AU - Bosch, Karen D
AU - Verhaagen, J.
AU - Yáñez-Muñoz, Rafael J
AU - Rogers, John H
AU - Schneider, Bernard L
AU - Muir, Elizabeth M
AU - Bradbury, Elizabeth J
PY - 2014/4/2
Y1 - 2014/4/2
N2 - Chondroitin sulfate proteoglycans (CSPGs) inhibit repair following spinal cord injury. Here we use mammalian-compatible engineered chondroitinase ABC (ChABC) delivered via lentiviral vector (LV-ChABC) to explore the consequences of large-scale CSPG digestion for spinal cord repair. We demonstrate significantly reduced secondary injury pathology in adult rats following spinal contusion injury and LV-ChABC treatment, with reduced cavitation and enhanced preservation of spinal neurons and axons at 12 weeks postinjury, compared with control (LV-GFP)-treated animals. To understand these neuroprotective effects, we investigated early inflammatory changes following LV-ChABC treatment. Increased expression of the phagocytic macrophage marker CD68 at 3 d postinjury was followed by increased CD206 expression at 2 weeks, indicating that large-scale CSPG digestion can alter macrophage phenotype to favor alternatively activated M2 macrophages. Accordingly, ChABC treatment in vitro induced a significant increase in CD206 expression in unpolarized monocytes stimulated with conditioned medium from spinal-injured tissue explants. LV-ChABC also promoted the remodelling of specific CSPGs as well as enhanced vascularity, which was closely associated with CD206-positive macrophages. Neuroprotective effects of LV-ChABC corresponded with improved sensorimotor function, evident as early as 1 week postinjury, a time point when increased neuronal survival correlated with reduced apoptosis. Improved function was maintained into chronic injury stages, where improved axonal conduction and increased serotonergic innervation were also observed. Thus, we demonstrate that ChABC gene therapy can modulate secondary injury processes, with neuroprotective effects that lead to long-term improved functional outcome and reveal novel mechanistic evidence that modulation of macrophage phenotype may underlie these effects.
AB - Chondroitin sulfate proteoglycans (CSPGs) inhibit repair following spinal cord injury. Here we use mammalian-compatible engineered chondroitinase ABC (ChABC) delivered via lentiviral vector (LV-ChABC) to explore the consequences of large-scale CSPG digestion for spinal cord repair. We demonstrate significantly reduced secondary injury pathology in adult rats following spinal contusion injury and LV-ChABC treatment, with reduced cavitation and enhanced preservation of spinal neurons and axons at 12 weeks postinjury, compared with control (LV-GFP)-treated animals. To understand these neuroprotective effects, we investigated early inflammatory changes following LV-ChABC treatment. Increased expression of the phagocytic macrophage marker CD68 at 3 d postinjury was followed by increased CD206 expression at 2 weeks, indicating that large-scale CSPG digestion can alter macrophage phenotype to favor alternatively activated M2 macrophages. Accordingly, ChABC treatment in vitro induced a significant increase in CD206 expression in unpolarized monocytes stimulated with conditioned medium from spinal-injured tissue explants. LV-ChABC also promoted the remodelling of specific CSPGs as well as enhanced vascularity, which was closely associated with CD206-positive macrophages. Neuroprotective effects of LV-ChABC corresponded with improved sensorimotor function, evident as early as 1 week postinjury, a time point when increased neuronal survival correlated with reduced apoptosis. Improved function was maintained into chronic injury stages, where improved axonal conduction and increased serotonergic innervation were also observed. Thus, we demonstrate that ChABC gene therapy can modulate secondary injury processes, with neuroprotective effects that lead to long-term improved functional outcome and reveal novel mechanistic evidence that modulation of macrophage phenotype may underlie these effects.
KW - Animals
KW - Cells, Cultured
KW - Chondroitin ABC Lyase
KW - Chondroitin Sulfate Proteoglycans
KW - Disease Models, Animal
KW - Electric Stimulation
KW - Female
KW - Gene Expression Regulation
KW - Genetic Therapy
KW - Injections, Spinal
KW - Macrophages
KW - Nerve Tissue Proteins
KW - Neural Conduction
KW - Psychomotor Performance
KW - Rats
KW - Rats, Sprague-Dawley
KW - Spinal Cord Injuries
KW - Time Factors
U2 - 10.1523/JNEUROSCI.4369-13.2014
DO - 10.1523/JNEUROSCI.4369-13.2014
M3 - Article
C2 - 24695702
SN - 0270-6474
VL - 34
SP - 4822
EP - 4836
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 14
ER -