Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.4.3.13 (lysyl oxidase)
 1,248 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was performed to compare the extractability of dwarf growth plate collagen and hexosamine and that of homozygous nonaffected Malamutes and to measure the activity of three of the enzymes involved in the post-translational modifications of the collagen molecule. No significant differences were found in the activity of prolyl hydroxylase or lysyl oxidase in the dwarf growth plates. Lysyl hydroxylase activity in the dwarf was decreased to 22% and 33% that of the activity present in the homozygous nonaffected growth plates. Amino acid analysis of the collagen isolated from dwarf growth plates failed to reveal any decrease in hydroxylysine content. Growth plates were extracted with either 1 M sodium chloride or 4 M guanidine hydrochloride. The extracts were applied to a DEAE-cellulose column. Amino acid analyses of the material which did not bind to DEAE revealed a slight decrease in the amount of guanidine-extractable hydroxyproline in the dwarf but a 60-fold increase in the amount of salt-extractable hydroxyproline in the dwarf growth plates. Material which eluted with 1 M sodium choloride was analyzed for hexosamine. There was a 10-fold increase in the amount of salt-extractable hexosamine present in the dwarf growth plates, whereas no significant differences were observed in the guanidine-extracted material. Hexosamine analysis of the growth plates revealed a significant increase in the total amount of hexosamine present in the dwarf growth plates. SDS-polyacrylamide gels of the material which did not bind to DEAE as well as the pepsin digested, 0.9M sodium chloride precipitated collagen demonstrated the presence of only type II collagen.
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PMID:Studies of the intercellular matrix of growth plates from dwarf and homozygous nonaffected Alaskan Malamutes: collagen and hexosamine. 625 32

The hallmark of fibrosis is the excessive accumulation of collagen. The deposited collagen contains increased pyridinoline cross-link levels due to an overhydroxylation of lysine residues within the collagen telopeptides. Lysyl hydroxylase 2b (LH2b) is the only lysyl hydroxylase consistently up-regulated in several forms of fibrosis, suggesting that an enhanced LH2b level is responsible for the overhydroxylation of collagen telopeptides. The present paper reports the effect of profibrotic cytokines on the expression of collagen, lysyl hydroxylases and lysyl oxidase in normal human skin fibroblasts, as well as the effect on pyridinoline formation in the deposited matrix. All three isoforms of TGF-beta induce a substantial increase in LH2b mRNA levels, also when expressed relatively to the mRNA levels of collagen type I alpha2 (COL1A2). The TGF-beta isoforms also clearly influence the collagen cross-linking pathway, since higher levels of pyridinoline cross-links were measured. Similar stimulatory effects on LH2b/COL1A2 mRNA expression and pyridinoline formation were observed for IL-4, activin A, and TNF-alpha. An exception was BMP-2, which has no effect on LH2b/COL1A2 mRNA levels nor on pyridinoline formation. Our data show for the first time that two processes, i.e., up-regulation of LH2b mRNA levels and increased formation of pyridinoline cross-links, previously recognized to be inherent to fibrotic processes, are induced by various profibrotic cytokines.
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PMID:Elevated formation of pyridinoline cross-links by profibrotic cytokines is associated with enhanced lysyl hydroxylase 2b levels. 1595 52

Lysyl hydroxylase (LH) catalyzes the hydroxylation of lysine residues in collagens, and contributes to the formation of more stable collagen cross-links. However, in teleost, there is little information about collagen modification enzymes including lysyl oxidase (LOX) family members. Here, we cloned cDNAs encoding LH1, 2 and 3 from tiger puffer Takifugu rubripes. To determine the mRNA expressions of LH family members in a tiger puffer, we performed a northern blot analysis. Results showed that both fgLH1 and fgLH3 mRNAs were almost constitutively expressed in tissues, but highly expressed in muscle and ovary, respectively. However, fgLH2 mRNA was detected only in RT-PCR, indicating that expression level of fgLH2 is very low in tissues. It may be that low expression level of fgLH2 contributes to the fewer contents of stable collagen cross-links in tiger puffer tissues. To further investigate expression profiles of fgLHs, we examined gene expressions in embryos during development. In embryos, expression profiles differ among three fgLHs, indicating that there are functional differences among the three fgLHs. This is the first report that examined gene expression patterns of three LHs in emrbyos and adult tissues in teleost.
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PMID:Cloning and expression of cDNA encoding lysyl hydroxylase 1, 2 and 3 in tiger puffer Takifugu rubripes. 2395 82