Chondroitinase treatment is a treatment of

proteoglycan Proteoglycans are proteins that are heavily glycosylated. The basic proteoglycan unit consists of a "core protein" with one or more covalently attached glycosaminoglycan (GAG) chain(s). The point of attachment is a serine (Ser) residue to whic ...

s, a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

in the fluid among cells where (among other things) they affect neural activity (communication,

plasticity Plasticity may refer to: Science * Plasticity (physics), in engineering and physics, the propensity of a solid material to undergo permanent deformation under load * Neuroplasticity, in neuroscience, how entire brain structures, and the brain it ...

). Chondroitinase treatment has been shown to allow adults vision to be restored as far as

ocular dominance Ocular dominance, sometimes called eye preference or eyedness, is the tendency to prefer visual perception, visual input from one eye to the other. It is somewhat analogous to the laterality of right- or left-handedness; however, the side of the d ...

is concerned. Moreover, there is some evidence that Chondroitinase could be used for the treatment of

spinal injuries A spinal cord injury (SCI) is damage to the spinal cord that causes temporary or permanent changes in its function. Symptoms may include loss of muscle function, sensory system, sensation, or autonomic nervous system, autonomic function in the p ...

. In addition, the enzyme that is used in the chondroitinase treatment, chondroitinase ABC, derives from the bacterium ''

Proteus vulgaris ''Proteus vulgaris'' is a rod-shaped, nitrate-reducing, indole-positive and catalase-positive, hydrogen sulfide-producing, Gram-negative bacterium that inhabits the intestinal tracts of humans and animals. It can be found in soil, water, and feca ...

.'' In recent years, pre-clinical research involving the chondroitinase ABC enzyme has been mainly directed towards utilizing it as a way of treating spinal cord injuries in test animals using

viral vector Viral vectors are tools commonly used by molecular biologists to deliver genetic material into cells. This process can be performed inside a living organism (''in vivo'') or in cell culture (''in vitro''). Viruses have evolved specialized molecul ...

s. In general, the way chondroitinase ABC works ''in vivo'' is it cleaves off the side chains of molecules known as

chondroitin sulfate proteoglycan Chondroitin sulfate proteoglycans (CSPGs) are proteoglycans consisting of a protein core and a chondroitin sulfate side chain. They are known to be structural components of a variety of human tissues, including cartilage, and also play key roles i ...

s (CSPGs) which are over produced by glial cells in the central nervous system when a spinal injury occurs. When chondroitin sulfate proteoglycans are bonded to their side chains called chondroitin sulfate glycosaminoglycans, these molecules are known to prevent neural restoration to the damaged region of the central nervous system because they form

glial scar Glial scar formation (gliosis) is a reactive cellular process involving astrogliosis that occurs after injury to the central nervous system. As with scarring in other organs and tissues, the glial scar is the body's mechanism to protect and begin ...

tissue which inhibits both neuroplasticity and repair of damaged axons. However, when the side chains of the chondroitin sulfate proteoglycans are cleaved by chondroitinase ABC, this promotes the damaged region of the CNS to recover from the spinal cord injury. It has recently been proposed that chondroitinase treatment promotes plasticity by activation of Tropomyosin receptor kinase B, receptor for Brain-derived neurotrophic factor and a major plasticity orchestrator in the brain. Cleavage of CSPGs by chondroitinase ABC leads to inactivation of

PTPRS Receptor-type tyrosine-protein phosphatase S, also known as R-PTP-S, R-PTP-sigma, or PTPσ, is an enzyme that in humans is encoded by the ''PTPRS'' gene. Function The protein encoded by this gene is a member of the protein tyrosine phosphata ...

, the membrane receptor for CSPGs and a phosphatase that inactivates TRKB under normal physiological conditions, which subsequently promotes TRKB phosphorylation and activation of neuroplasticity.

References

Neurology procedures {{biochem-stub

See also

References