Removal of an enzyme required for biosynthesis of chondroitin sulphate - a component of scars in the nervous system - leads to improved motor function recovery in mice after spinal cord injury. This study, reported a paper published in Nature Communications, enhances our understanding of recovery from spinal cord injury and could point towards a new target for therapy after such injuries.
Proteoglycans are components of glial scars that form upon spinal cord injury and that work to help heal the central nervous system, but also prevent regrowth of neurons. Treatment of mice with chondroitinase - an enzyme that degrades the proteoglycan chondroitin sulphate - is known to improve recovery from spinal cord lesions. Michihiro Igarashi and colleagues now show that by knocking out an enzyme for chondroitin sulphate synthesis in mice, the animals have smaller glial scars, higher neuronal regrowth and improved motor function of limbs after spinal cord injury than mice treated with chondroitinase. They show that this is not only due to reduced chondroitin sulphate levels, but also due to an increase in the levels of another proteoglycan, heparin sulphate, which is known to promote axon growth.