Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.6.4 (chondroitinase)
 2,039 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Damaged axons do not regenerate after axotomy in the adult mammalian central nervous system (CNS). This may be due to local inhibitory factors at the site of injury, such as overexpression of chondroitin sulfate (CS) proteoglycans (CSPG), and the presence of myelin-associated inhibitors (MAI). To overcome CSPG- or myelin-induced inhibition, strategies based on extrinsic and intrinsic treatments have been developed. For example, NEP1-40 is a synthetic peptide that promotes axonal regeneration by blocking Nogo-66/NgR interaction and chondroitinase ABC (ChABC), which degrades CS, thereby also promoting axon regrowth. Here, we examined whether the combination of these complementary strategies facilitates regeneration of the lesioned entorhino-hippocampal pathway (EHP) in slice cultures. In this model, overexpressed CSPG and MAI impaired axon regrowth, which mimics regeneration failure in vivo. Both CS cleavage with ChABC and NEP1-40 strongly facilitated the regrowth of entorhinal axons after axotomy, permitting the re-establishment of synaptic contacts with target cells. However, the combined treatment did not improve the regeneration induced by ChABC alone, and the delayed treatment of ChABC, but not NEP1-40, had a less pronounced effect on axonal regrowth compared with acute treatment. These results provide insight into the development of new assays and strategies to enhance axon regeneration in injured cortical connections.
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PMID:Regeneration of lesioned entorhino-hippocampal axons in vitro by combined degradation of inhibitory proteoglycans and blockade of Nogo-66/NgR signaling. 1640 55

A multifaceted therapeutic approach involving biomaterial scaffolds, neurotrophic factors, exogenous cells, and antagonists to axon growth inhibitors may ultimately prove necessary for the treatment of defects resulting from spinal cord injury (SCI). The objective of this study was to begin to lay the groundwork for such strategies by implanting type I collagen scaffolds alone and incorporating individually a soluble Nogo receptor, chondroitinase ABC (ChABC), and mesenchymal stem cells (MSCs) into a standardized 3-mm-long hemiresection defect in the rat spinal cord. Statistically significant improvement in hindlimb motor function between the first and fourth weeks post-SCI was recorded for the scaffold-alone group and for the ChABC and MSC groups, but not the control group. Four weeks post-SCI, the scaffolds appeared intact with open pores, which were infiltrated with host cells. Of note is that in some cases, a few growth-associated protein 43 (GAP-43)-positive axons were seen reaching the center of the scaffold in the scaffold-alone and ChABC groups, but not in control animals. Angiogenic cells were prevalent in the scaffolds; however, the number of both macrophages and angiogenic cells in the scaffolds was significantly less than in the control lesion at 4 weeks. The results lay the foundation for future dose-response studies and to further investigate a range of therapeutic agents to enhance the regenerative response in SCI.
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PMID:Collagen scaffolds incorporating select therapeutic agents to facilitate a reparative response in a standardized hemiresection defect in the rat spinal cord. 2282 32

Myelin-associated inhibitors (MAIs) and chondroitin sulfate proteoglycans (CSPGs) are major contributors to axon growth inhibition following spinal cord injury and limit functional recovery. The NEP1-40 peptide competitively binds the Nogo receptor and partially blocks inhibition from MAIs, while chondroitinase ABC (ChABC) enzymatically digests CSPGs, which are upregulated at the site of injury. In vitro studies showed that the combination of ChABC and NEP1-40 increased neurite extension compared to either treatment alone when dissociated embryonic dorsal root ganglia were seeded onto inhibitory substrates containing both MAIs and CSPGs. Furthermore, the ability to provide sustained delivery of biologically active ChABC and NEP1-40 from biomaterial scaffolds was achieved by loading ChABC into lipid microtubes and NEP1-40 into poly (lactic-co-glycolic acid) (PLGA) microspheres, obviating the need for invasive intrathecal pumps or catheters. Fibrin scaffolds embedded with the drug delivery systems (PLGA microspheres and lipid microtubes) were capable of releasing active ChABC for up to one week and active NEP1-40 for over two weeks in vitro. In addition, the loaded drug delivery systems in fibrin scaffolds decreased CSPG deposition and development of a glial scar, while also increasing axon growth after spinal cord injury in vivo. Therefore, the sustained, local delivery of ChABC and NEP1-40 within the injured spinal cord may block both myelin and CSPG-associated inhibition and allow for improved axon growth.
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PMID:Sustained dual drug delivery of anti-inhibitory molecules for treatment of spinal cord injury. 2612 30