Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
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Drug
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Target Concepts:
Gene/Protein
Disease
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Enzyme
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Query: EC:1.4.3.13 (
lysyl oxidase
)
1,248
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The palmar aponeurosis removed from ten patients with
Dupuytren's contracture
was studied using morphological and biochemical approaches. The histological characteristic of
Dupuytren's contracture
is the presence of numerous nodules among the lamellar structures of the collagen fibres. In the nodules, there are many active fibroblasts which are surrounded by immature fibres and metachromatic substances demonstrated by toluidine blue staining. Ultrastructurally, the active fibroblasts have the characteristics of myofibroblasts, as previously reported by Dr. Gabbiani. We found that some fibroblasts have intracellular collagen fibrils in the cytoplasm. When assayed by Siegel and Martin's method,
lysyl oxidase
activity of the palmar aponeurosis was significantly higher in
Dupuytren's contracture
than in normal hands. Biochemical studies such as electrophoretic analysis of mucopolysaccharides, determination of uronic acid and collagen contents were undertaken to compare the aponeurosis of
Dupuytren's contracture
with normal cases. The uronic acid contents were higher in
Dupuytren's contracture
than in the controls. However, no difference between the two groups was found in the collagen contents and in the composition of the mucopolysaccharides. These characteristic features; existence of myofibroblasts and intracellular collagen fibrils and increase in the activity of
lysyl oxidase
probably play a significant role in the establishment of flexion contracture of the fingers in
Dupuytren's contracture
.
...
PMID:Dupuytren's contracture: morphological and biochemical changes in palmar aponeurosis. 613 30
Fibrosis is characterized by an excessive accumulation of collagen which contains increased levels of pyridinoline cross-links. The occurrence of pyridinolines in the matrix is an important criterion in assessing the irreversibility of fibrosis, which suggests that collagen containing pyridinoline cross-links significantly contributes to the unwanted collagen accumulation. Pyridinoline cross-links are derived from hydroxylated lysine residues located within the collagen telopeptides (hydroxyallysine pathway). Here, we have investigated whether the increase in hydroxyallysine-derived cross-links in fibrotic conditions can be ascribed to an increased expression of one of the lysyl hydroxylases (LH1, LH2 with its splice variants LH2a and LH2b, or LH3) and/or to an increased expression of
lysyl oxidase
(
LOX
). In fibroblast cultures of hypertrophic scars, keloid and palmar fascia of
Dupuytren
's patients, as well as in activated hepatic stellate cells, increased levels of LH2b mRNA expression were observed. Only minor amounts of LH2a were present. In addition, no consistent increase in the mRNA expression levels of LH1, LH3 and
LOX
could be detected, suggesting that LH2b is responsible for the overhydroxylation of the collagen telopeptides and the concomitant formation of pyridinolines as found in the collagen matrix deposited in long-term cultures by the same fibrotic cells. This is consistent with our previous observation that LH2b is a telopeptide lysyl hydroxylase. We conclude that the increased expression of LH2b, leading to the increased formation of pyridinoline cross-links, is present in a wide variety of fibrotic disorders and thus represents a general fibrotic phenomenon.
...
PMID:Increased formation of pyridinoline cross-links due to higher telopeptide lysyl hydroxylase levels is a general fibrotic phenomenon. 1529 39
