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

Human promyelocytic cells (HL-60) were labeled with 35S-sulfate and either 3H-glucosamine or 3H-serine as precursors. Accumulation of 35S-labeled macromolecules was approximately linear for up to 96 h, with a mean cell:medium ratio of 5.5:1, although activity/10(5) viable cells reached a plateau level after 24 h. Virtually none of the cell-associated proteoglycan was removed by trypsinization, consistent with a predominantly intracellular localization. Proteoglycan heterogeneity was investigated by DEAE-Sephacel chromatography, isopyknic CsCl gradient centrifugation, and gel filtration chromatography. HL-60 cells appeared to synthesize a single proteoglycan species, Kav = 0.46 on Sepharose CL-4B and Kav = 0.32 on Sepharose CL-6B, recovered primarily from the high-density fractions of a dissociative CsCl gradient (rho greater than 1.40 g/l). Degradation products of lower charge density, lower buoyant density, and lower hydrodynamic size were also present, mainly in the cell pellets. The major proteoglycan was found to contain chondroitin sulfate chains of average Mr = 14.5 kD, yielding virtually 100% 4-sulfated disaccharides on digestion with chondroitinase ABC. The proteoglycan was resistant to trypsin, chymotrypsin, plasmin, and papain, and the core protein Mr was approximately 20 kD by molecular sieve chromatography. Induction of HL-60 cells with 0.15 dimethyl sulfoxide (DMSO) resulted in differentiation to a more mature granulocytic phenotype and was associated with a reduction in 35S-sulfate incorporation to 45% of control values or 32%, expressed as activity/10(5) cells. Proteoglycans synthesized by DMSO-treated cells were identical to those from untreated cells in terms of hydrodynamic size, glycosaminoglycan Mr, and sulfation.
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PMID:Biosynthesis of proteochondroitin sulfate by HL-60 human promyelocytic cells. 291 Oct 20

Epithelial tissues are characterized by specialized cell-cell junctions, typically localized to the apical regions of cells. These junctions are formed by interacting membrane proteins and by cytoskeletal and extracellular matrix components. Within the lingual epithelium, tight junctions join the apical tips of the gustatory sensory cells in taste buds. These junctions constitute a selective barrier that limits penetration of chemosensory stimuli into taste buds (Michlig et al. J Comp Neurol 502: 1003-1011, 2007). We tested the ability of chemical compounds to permeate into sensory end organs in the lingual epithelium. Our findings reveal a robust barrier that surrounds the entire body of taste buds, not limited to the apical tight junctions. This barrier prevents penetration of many, but not all, compounds, whether they are applied topically, injected into the parenchyma of the tongue, or circulating in the blood supply, into taste buds. Enzymatic treatments indicate that this barrier likely includes glycosaminoglycans, as it was disrupted by chondroitinase but, less effectively, by proteases. The barrier surrounding taste buds could also be disrupted by brief treatment of lingual tissue samples with DMSO. Brief exposure of lingual slices to DMSO did not affect the ability of taste buds within the slice to respond to chemical stimulation. The existence of a highly impermeable barrier surrounding taste buds and methods to break through this barrier may be relevant to basic research and to clinical treatments of taste.
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PMID:A permeability barrier surrounds taste buds in lingual epithelia. 2587 57

While it is well established that the axons of adult neurons have a lower capacity for regrowth, some regeneration of certain CNS populations after spinal cord injury (SCI) is possible if their axons are provided with a permissive substrate, such as an injured peripheral nerve. While some axons readily regenerate into a peripheral nerve graft (PNG), these axons almost always stall at the distal interface and fail to reinnervate spinal cord tissue. Treatment of the glial scar at the distal graft interface with chondroitinase ABC (ChABC) can improve regeneration, but most regenerated axons need further stimulation to extend beyond the interface. Previous studies demonstrate that pharmacologically inhibiting kinesin-5, a motor protein best known for its essential role in mitosis but also expressed in neurons, with the pharmacological agent monastrol increases axon growth on inhibitory substrates in vitro. We sought to determine if monastrol treatment after an SCI improves functional axon regeneration. Animals received complete thoracic level 7 (T7) transections and PNGs and were treated intrathecally with ChABC and either monastrol or DMSO vehicle. We found that combining ChABC with monastrol significantly enhanced axon regeneration. However, there were no further improvements in function or enhanced c-Fos induction upon stimulation of spinal cord rostral to the transection. This indicates that monastrol improves ChABC-mediated axon regeneration but that further treatments are needed to enhance the integration of these regrown axons.
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PMID:Pharmacologically inhibiting kinesin-5 activity with monastrol promotes axonal regeneration following spinal cord injury. 2544 35