elastin and deoxypyridinoline

In an attempt to identify potential staging markers of effective healing, changes in connective tissue properties were measured in a human skin excisional wound healing model in which tissue was re-excised at intervals up to 6 months after injury. The proportion of collagen III relative to collagen I increased significantly (p<0.001) up to 6 weeks after initial injury and remained elevated up to 6 months, at which time the proportion of collagen III was 70% above baseline values. Extractability of biopsy tissue collagen by pepsin increased significantly throughout the study (baseline, 32.8+/-6.8%; 6 months, 89.1+/-8.9%), with inverse changes in the mature skin cross-link, histidinohydroxylysinonorleucine (baseline, 1.18+/-0.11 mol/mol collagen; 6 months, 0.27+/-0.09 mol/mol collagen). Pyridinoline content increased over the period of the study, although remaining at relatively low concentrations (baseline, 0.037+/-0.011; 6 months, 0.063+/-0.014 mol/mol collagen), and the pyridinoline/deoxypyridinoline ratio was significantly higher (baseline, 3.5+/-0.6; 6 months, 10.3+/-2.2). Elastin content, measured as desmosine cross-links, decreased significantly in the first 3 weeks and continued to decline over the period of study. Overall, the data suggest that remodeling of the wound tissue continues at least up to 6 months after injury. The close inverse correlation between histidinohydroxylysinonorleucine concentrations and extractability by pepsin (r2=0.89, p<0.0001) suggests a causal relationship, consistent with the likely effects of a substantial network of mature, inter-helical bonds in collagen.

Topics: Adult; Amino Acids; Collagen; Collagen Type I; Collagen Type III; Dipeptides; Elastin; Histidine; Humans; Male; Skin; Time Factors; Wound Healing; Wounds, Penetrating

The cranial skeleton of the lamprey, a primitive vertebrate, consists of cartilaginous structures that differ from vertebrate cartilages in having a noncollagenous extracellular matrix. Novel matrix proteins found in these cartilages include lamprin in the annular cartilage and an unidentified protein in the branchial cartilages. Both show biochemical similarities to elastin. The inextractability of these proteins, even to chemical cleavage by cyanogen bromide, indicates a polymer with extensive covalent cross-linking. Here we report on the type of cross-linking. Lysyl pyridinoline was found in high concentration in the elastin-like protein of lamprey branchial cartilage at a ratio of 7:1 to hydroxylysyl pyridinoline, the form that dominates in vertebrate collagens. Both forms of pyridinoline cross-link were absent from annular cartilage and desmosine cross-links, which are characteristic of vertebrate elastin, were not detected in either form of lamprey cartilage. Pyridinoline cross-links are considered to be characteristic of collagen, so their presence in an elastin-like protein in a primitive cartilage poses evolutionary questions about the tissue, the protein, and the cross-linking mechanism.

Topics: Amino Acids; Animals; Cartilage; Cattle; Chromatography, High Pressure Liquid; Collagen; Cross-Linking Reagents; Cyanogen Bromide; Elastin; Extracellular Matrix; Humans; Lampreys; Proteins; Spectrometry, Fluorescence

Urinary levels of collagen- and elastin-crosslink amino acids have been used as biologic markers for degradation of collagen and elastin in the body. Circadian variation of collagen-crosslink amino acids is well known. The current study was undertaken to determine whether there is also circadian variation in excretion of elastin-crosslink amino acids. We used an isotope dilution-HPLC assay to measure the elastin-crosslink amino acids, desmosine (DES) and isodesmosine (IDES), and the collagen-crosslink amino acids, hydroxylysyl pyridinoline (HP) and lysyl pyridinoline (LP), in urine. Sixteen apparently healthy subjects collected urine from 5:00 to 7:00 AM, and from 5:00 to 7:00 PM. Mean urinary excretion of DES and IDES in women was 56% and 41% higher (P < 0.001), respectively, in AM versus PM specimens when normalized by the creatinine content of the urine specimen. For men, the corresponding values were 11% and 13% higher (not statistically significant). Mean urinary excretion of HP and LP in women was 61% and 71% higher (P < 0.001), respectively, in AM versus PM specimens. For men, the corresponding values were 11% and 19% higher (not statistically significant). Differences were not found in the AM versus PM rates of excretion of creatinine in men or women. These findings demonstrate the occurrence of circadian variation in HP, LP, DES and IDES in women but not in men. We conclude that the time of collection of urine specimens, especially from women, must be taken into consideration in using the urinary levels of these crosslink amino acids as biologic markers for collagen or elastin degradation.

Topics: Adult; Amino Acids; Biomarkers; Circadian Rhythm; Collagen; Cross-Linking Reagents; Desmosine; Elastin; Female; Humans; Isodesmosine; Male; Middle Aged; Reference Values; Sex Characteristics

Elastin degradation has been reported to be increased in patients with cystic fibrosis (CF). In order to further explore evidence for elastin degradation in a group of 18 patients with CF with a wide range of disease severity, we used an isotope dilution method to measure urinary desmosine (DES) and isodesmosine (IDES), amino acids derived exclusively from cross-linked elastin, and hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP), amino acids derived exclusively from cross-linked collagen. Urinary DES and IDES (mean +/- SD) were 23.9 +/- 30.7 and 18.5 +/- 22.4 micrograms/g creatinine, respectively, in the patients with CF versus 7.5 +/- 1.7 and 6.8 +/- 1.4 micrograms/g creatinine, respectively, in 10 healthy control subjects (p < 0.001); only two patients with CF had DES values within the control range. The values of urinary HP and LP in the CF group were 54.9 +/- 39.1 and 12.3 +/- 8.6 nmol/mmol creatinine, respectively, versus 24.5 +/- 5.8 and 5.1 +/- 2.7 nmol/mmol creatinine, respectively, in the controls (p < 0.005). Both HP and LP were highly correlated (r = 0.71, p < 0.0001). Patients with CF had active pulmonary inflammation; neutrophils were abundant in the bronchoalveolar lavage fluid of the CF group and correlated with elastase activity measured with methoxysuccinyl Ala-Ala-Pro-Val paranitroanilide (r = 0.61, p < 0.05). Airway neutrophils had decreased expression of the complement receptor CR1 (CR1/CR3 of 0.17 +/- 0.15 versus 1.0 for blood neutrophils), a change known to be caused by uninhibited neutrophil elastase. We conclude that lung elastin is the most likely source of the increased DES and IDES in CF.

Topics: Adult; Amino Acids; Bronchoalveolar Lavage Fluid; Case-Control Studies; Collagen; Cystic Fibrosis; Desmosine; Elastin; Female; Humans; Isodesmosine; Leukocyte Elastase; Male; Neutrophils; Pancreatic Elastase; Receptors, Complement

One of the most rapid changes in collagen and elastin content of a tissue occurs in the uterus following postpartum involution. We measured the urinary excretion of specific amino acid markers for mature elastin (desmosine [DES] and isodesmosine [IDES]) and fibrillar collagen (hydroxylysyl pyridinoline [HP] and lysyl pyridinoline [LP]) before and after parturition in three gravid subjects. For that purpose, we used an isotope dilution method coupled with gel filtration and HPLC. The highest DES values were found 2-5 weeks postpartum and were 18-45 micrograms/g creatinine or two to six times those found for healthy neversmoking nongravid females (7.7 +/- 0.3 micrograms/g creatinine, mean +/- SE). The highest levels of urinary HP for each subject were found 2-3 weeks after parturition and were 115-607 nmol/mmol creatinine or 4-21 times those found for healthy neversmoking nongravid females (28.1 +/- 1.3 nmol/mmol creatinine). For the gravid subjects as a group and also for each subject, the mean values for urinary DES, IDES, HP, and HP/LP during the first 6 weeks postpartum were significantly greater than the mean baseline values beginning 27 weeks postpartum. For the gravid subjects as a group, the mean value for urinary HP/LP during the first 6 weeks postpartum was significantly greater than the value during the 20 weeks preceding parturition. This suggested that the tissue(s) of origin of the excess HP, during the 6 weeks following parturition, was not bony and was consistent with a uterine origin.

Topics: Amino Acids; Collagen; Creatinine; Desmosine; Elastin; Female; Humans; Kinetics; Postpartum Period; Pregnancy; Reference Values; Smoking; Uterus

It has been hypothesized that emphysema results from damage to the elastic fiber network of the lungs as a result of elastase-antielastase imbalance. We used a new assay for urinary desmosine (DES) and isodesmosine (IDES), specific markers for the degradation of mature crosslinked elastin, and hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP), specific markers for the degradation of mature crosslinked collagen, in order to examine elastin and collagen degradation in relation to current cigarette smoking and the presence of chronic obstructive pulmonary disease (COPD). The study sample consisted of 22 never-smokers (NSM group), 13 current smokers without airflow obstruction (SM group), and 21 patients with COPD (COPD group), including both current and former smokers. The relation between the creatinine-height index and FEV1 was used to correct for possible loss of muscle mass and decreased excretion of creatinine in the COPD group. Mean urinary excretion of elastin-derived crosslinks in the COPD group (DES, 11.8 +/- 5.1 [mean +/- SD]; IDES, 11.3 +/- 5.0 micrograms/g creatinine) and in the SM group (DES, 11.0 +/- 4.2; IDES, 10.2 +/- 2.5 micrograms/g creatinine) was significantly higher than in the NSM group (DES, 7.5 +/- 1.4; IDES, 6.9 +/- 1.3 micrograms/g creatinine). In multivariate analysis, current smoking and the presence of COPD were significantly and independently associated with higher urinary excretion of elastin degradation products, and there was no significant interaction between current smoking and the presence of COPD.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Amino Acids; Biomarkers; Collagen; Desmosine; Elastin; Female; Humans; Isodesmosine; Lung Diseases, Obstructive; Male; Middle Aged; Prospective Studies; Smoking

To measure the urinary excretion of specific cross-link amino acid markers for mature elastin (desmosine [DES] and isodesmosine [IDES]) and fibrillar collagen (hydroxylysylpyridinoline [HP] and lysylpyridinoline [LP]) in systemic sclerosis (SSc) patients and healthy controls.. Urine specimens from 20 patients with SSc and 22 controls were assessed for DES, IDES, HP, and LP using high performance liquid chromatography and ultraviolet absorption spectroscopy, in combination with an isotope dilution technique in which the urine specimen was spiked with isotopically labeled cross-link amino acids.. Mean +/- SD levels of urinary DES and IDES were elevated in SSc patients by 2-3-fold, and urinary HP and LP by 3-4-fold, compared with controls (DES 21.0 +/- 9.4 versus 7.5 +/- 1.4 micrograms/gm creatinine; HP 109.0 +/- 72.9 versus 24.9 +/- 5.7 nmoles/mmole creatinine). Nineteen of the 20 SSc patients had urinary DES and HP values that were > 3 SD above the control mean. A significant elevation in the HP:LP ratio in SSc patients as compared with controls (mean +/- SD 6.9 +/- 1.5 versus 5.5 +/- 1.3) indicated a soft tissue origin for much of the increased HP.. Patients with SSc have higher levels of urinary cross-link amino acids specific for the degradation of mature collagen and elastin. These markers distinguish most SSc patients from healthy controls.

Topics: Adult; Aged; Amino Acids; Collagen; Desmosine; Elastin; Female; Humans; Isodesmosine; Male; Middle Aged; Reference Values; Scleroderma, Systemic