desmosine and pyridinoline

Liver fibrosis is a serious complication of schistosomiasis infection, is associated with increased amounts of collagen and the collagen cross-link, pyridinoline. Non-invasive markers of liver fibrosis have been developed. Serum and urinary markers of collagen synthesis and degradation have been studied to assess the balance between collagen synthesis, measured with markers of collagen synthesis such as amino-terminal propeptide of type III procollagen (PIIINP), and markers of degradation such as pyridinoline or pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP). It has been shown that mice infected with Schistosomiasis mansoni excrete excess pyridinoline cross links in urine and this was correlated with the collagen content of granulomas from the liver. Treatment of infected mice with an anti-parasitic drug, praziquantel, decreased the collagen content of parenchyma and excretion of pyridinoline in the urine. Although the connective tissue protein, elastin, is present in the liver, the role of elastin in liver fibrosis has not been investigated. However, it has been shown that the urinary concentration of elastin specific crosslinks, desmosine and isodesmosine, as well as the urinary concentration of the collagen crosslink, pyridinoline, correlated well with liver fibrosis score in biopsy specimens from patients with liver disease secondary to hepatitis C virus and alcohol. Each biopsy specimen was reviewed by two pathologists who were blinded as to the clinical data. The pathological evaluation generated scores for both inflammation and fibrosis. No correlation was seen between the urinary markers and inflammation scores. The measurement of non-invasive markers of collagen synthesis and degradation may be useful in monitoring the reversal of fibrosis following therapeutic intervention in schistosome infections.

Topics: Amino Acids; Animals; Biomarkers; Collagen; Desmosine; Elastin; Humans; Isodesmosine; Liver Cirrhosis; Schistosomiasis

Changes in the process of cross-linking of collagen molecules are associated with defects in the biomechanical stability of the extracellular matrix. Fibrosis of skin is characterized by an increase in pyridinolines, which are hydroxylysine aldehyde derived cross-links usually absent in healthy skin. In this study, we analyzed cross-links in lipodermatosclerosis and localized scleroderma to address the question whether all the mature cross-links currently characterized are increased in fibrosis in addition to the increase in pyridinolines. As psoralen plus ultraviolet A treatment leads to clinical improvement of fibrotic plaques in localized scleroderma we analyzed the cross-link content in lesional skin after bath psoralen plus ultraviolet A therapy. In skin from patients with localized scleroderma an increase in the total number of mature cross-links was found to be due to an increase in both pyridinolines and dehydro-histidinohydroxymerodesmosine. The concentration of histidinohydroxylysinonorleucine was unchanged. By contrast, the total number of mature cross-links was decreased in lipodermatosclerosis. This decrease was caused by a decrease of lysine aldehyde derived cross-links (dehydro-histidinohydroxymerodesmosine and histidinohydroxylysinonorleucine), whereas the concentration of pyridinolines increased. A decrease in the content of pyridinolines after bath psoralen plus ultraviolet A treatment was found in six out of nine patients with localized scleroderma, which might reflect a remodeling of the extracellular matrix. Our data provide evidence that sclerosis of skin is associated with either an increase in the number of cross-links per molecule of collagen or a change in the molecular nature of the cross-links formed.

Topics: Amino Acids; Collagen; Cross-Linking Reagents; Desmosine; Fibrosis; Humans; Hydroxylation; Hydroxylysine; PUVA Therapy; Pyridones; Scleroderma, Localized; Ultraviolet Rays

We assessed the effects of D-penicillamine (D-PA) on cross-linkages in elastin and vaso-regulatory function in rats. After administration of D-PA at a dose of 100 mg/kg/day for 7 weeks to adult and young rats, the thoracic aortas were isolated. The elastic lamellae in the aorta were disrupted histopathologically in all the treated groups. The content of cross-linkages in elastin, i.e. desmosine and isodesmosine, which gives elasticity to the aortic wall, was significantly reduced in the D-PA treated groups versus the control groups. On the other hand, the content of pyridinoline as a marker of insoluble collagen was significantly reduced in the D-PA treated groups, even though the total collagen content was not changed. In addition, after 7 weeks of treatment with D-PA, the change between systolic blood pressure before and after sympathetic stimulation (Δ-SBP) by L-epinephrine was about 2.5-fold larger than that in the control group. Similar results were obtained using angiotensin II or ouabain instead of L-epinephrine. These findings demonstrated that D-PA disrupted elastic lamellae of the rat aorta by reduction of the cross-linkages in elastin and collagen, which caused dysfunction of vaso-regulation. Also, they suggested the possibility that long-term treatment with D-PA in patients could cause a decrease in vaso-regulatory function and could increase the risk of cardiovascular events.

Topics: Administration, Oral; Age Factors; Amino Acids; Animals; Aorta; Arterial Pressure; Cardiovascular Diseases; Chelating Agents; Desmosine; Elastic Tissue; Elasticity; Elastin; Humans; Injections, Subcutaneous; Isodesmosine; Male; Penicillamine; Rats; Rats, Sprague-Dawley

We assessed the effects of rofecoxib on cross-linkage formation in elastin and vaso-regulatory function in rats. After administration of rofecoxib at a dose of 10 mg/kg for 7 weeks to young rats and for 7 and 10 weeks to adult rats, thoracic aortas were isolated. The elastic lamellae in the aortas were disrupted histopathologically in all the treated groups. However, the content of cross-linkages in elastin, i.e. desmosine and isodesmosine, which give elasticity to the aortic wall, was not significantly different between the rofecoxib treated and control groups. On the other hand, although the baseline blood pressure was not changed during the treatment period in both young and adult rats, after several weeks of treatment with rofecoxib the change between systolic blood pressure before and after sympathetic stimulation by L-epinephrine was 2 to 3-fold larger than that in the control group. Similar results were obtained using angiotensin II instead of L-epinephrine. The exposure to rofecoxib (area under the plasma concentration-time curve) of rats after single administration was a few times higher than that of humans in clinical use. These findings indicate that rofecoxib did not directly inhibit formation of cross-linkages in elastin of the aorta in rats. However, the treatment with rofecoxib for several weeks disrupted elastic lamellae and caused depression of vaso-regulatory function in rats, which could bring on an increased risk of cardiovascular events in human.

Topics: Administration, Oral; Age Factors; Amino Acids; Animals; Aorta; Arterial Pressure; Cardiovascular Diseases; Cyclooxygenase 2 Inhibitors; Desmosine; Elastic Tissue; Elasticity; Elastin; Humans; Injections, Subcutaneous; Isodesmosine; Lactones; Male; Rats; Rats, Sprague-Dawley; Sulfones

A key challenge in tissue engineering a heart valve is to reproduce the major tissue structures responsible for native valve function. Here we evaluated human adipose-derived stem cells (ADSCs) as a source of cells for heart valve tissue engineering investigating their ability to synthesize and process collagen and elastin. ADSCs were compared with human bone marrow mesenchymal stem cells (BmMSCs) and human aortic valve interstitial cells (hVICs). ADSCs and BmMSCs were stretched at 14% for 3 days and collagen synthesis determined by [(3)H]-proline incorporation. Collagen and elastin crosslinking was assessed by measuring pyridinoline and desmosine respectively, using liquid chromatography/mass spectrometry. Three-dimensional culture was obtained by seeding cells onto bovine collagen type I scaffolds for 2-20 days. Expression of matrix proteins and processing enzymes was assessed by Real Time-PCR, immunofluorescence and transmission electron microscopy. Stretch increased the incorporation of [(3)H]-proline in ADSCs and BmMSCs, however only ADSCs and hVICs upregulated COL3A1 gene. ADSCs produced collagen and elastin crosslinks. ADSCs uniformly populated collagen scaffolds after 2 days, and fibrillar-like collagen was detected after 20 days. ADSCs sense mechanical stimulation and produce and process collagen and elastin. These novel findings have important implications for the use of these cells in tissue engineering.

Topics: Adipose Tissue; Adult; Amino Acids; Cell Shape; Collagen; Cross-Linking Reagents; Desmosine; Elastin; Extracellular Matrix; Gene Expression Regulation; Heart Valve Prosthesis; Humans; Mesenchymal Stem Cells; Middle Aged; Phenotype; Proline; Stem Cells; Stress, Mechanical; Tissue Engineering; Tissue Scaffolds

The aim of this study is to develop a standardized LC-MS/MS method for accurate measurement of desmosine (DES) and isodesmosine (IDS) in all body fluids as biomarkers for in vivo degradation of matrix tissue elastin in man and animals. A reproducible three-step analytical procedure: (1) sample hydrolysis in 6N HCl, (2) SPE by a CF1 cartridge with addition of acetylated pyridinoline as internal standard (IS), and (3) LC/MSMS analysis by SRM monitoring of transition ions; DES or IDS (m/z 526-481+397) and IS (m/z 471-128) was developed. The method achieves accurate measurements of DES/IDS in accessible body fluids (i.e. urine, plasma, and sputum). LOQ of DES/IDS in body fluids is 0.1 ng/ml. The % recoveries and reproducibility from urine, plasma, and sputum samples are above 99 ± 8% (n = 3), 94 ± 9% (n = 3) and 87 ± 11% (n = 3), with imprecision 8%, 9% and 10%, respectively. The proposed method was applied to measure DES/IDS in body fluids of patients with chronic obstructive pulmonary disease (COPD) and healthy controls. Total DES/IDS in sputum and plasma is increased over normal controls along with the free DES/IDS in urine in patients. DES/IDS can be used to study the course of COPD and the response to therapy. This practical and reliable LC-MS/MS method is proposed as a standardized method to measure DES and IDS in body fluids. This method can have wide application for investigating diseases which involve elastic tissue degradation.

Topics: Amino Acids; Biomarkers; Case-Control Studies; Chromatography, Liquid; Desmosine; Elastin; Humans; Hydrochloric Acid; Hydrolysis; Isodesmosine; Pulmonary Disease, Chronic Obstructive; Reproducibility of Results; Sensitivity and Specificity; Sputum; Tandem Mass Spectrometry

Chronic graft-versus-host disease (cGVHD) is a common and potentially lethal complication of allogeneic hematopoietic stem cell transplantation (HSCT). cGVHD as well as the transplant procedure itself (chemotherapy with or without radiotherapy) can lead to the degradation of connective tissue components such as elastin and collagen. The catabolism of these structural proteins releases desmosine (DES), lysylpyridinoline (LP), hydroxylysylpyridonoline (HP), and related pyridinium-based cross-linkers analogues that could represent potential biomarkers for cGVHD. This study reports the development of a sensitive liquid chromatography/tandem mass spectrometry method for the simultaneous analysis of N-propyl derivatives of DES, HP, and LP. The concentrations of free and total forms of urinary DES, HP, and LP were determined using synthetic deuterated internal standards. This method enabled accurate quantitation of these pyridinium-based cross-linkers from as little as 100 microL of urine with detection limits of 0.03-0.10 ng/mL. These compounds were analyzed in urine samples from three groups of patients: (1) Healthy volunteers, (2) Autologous HSCT recipients (who cannot develop cGVHD), and (3) Allogeneic HSCT recipients at onset of cGHVD. These analyses revealed that the urinary concentrations of DES, HP, and LP in the autologous recipients were greater or equal to the cGVHD group although both groups showed marked increase in the levels of these compounds compared to healthy individuals. These results suggest that the chemotherapy treatment has significant effects on the turnover of elastin and collagen, and that these biomarkers could be effective during prospective analyses to determine the onset of cGVHD.

Topics: Adult; Aged; Amino Acids; Biomarkers; Chromatography, Liquid; Desmosine; Female; Graft vs Host Disease; Hematopoietic Stem Cell Transplantation; Humans; Male; Middle Aged; Tandem Mass Spectrometry

To elucidate the roles of LH2b in collagen cross-linking, MC3T3-E1 cell clones expressing higher (S) or lower (AS) levels of LH2b were established. Compared with controls, the collagen cross-linking pattern was shifted toward hydroxylysine-aldehyde (S clones)- or lysine-aldehyde (AS clones)-derived pathways. The data indicate that LH2b directs collagen cross-linking pathways through its action on telopeptidyl lysine residues.. Lysine (Lys) hydroxylation is a post-translational modification of collagen critical for cross-linking and glycosylation. Currently, three isoforms of lysyl hydroxylase (LH) have been identified, but their specific functions are still not well defined. Recently, we proposed that LH2 might modulate collagen cross-linking pattern through its action on Lys residues located in the telopeptide domains of collagen.. To directly test this hypothesis, several MC3T3-E1 cell-derived clones expressing higher (sense [S]) or lower (antisense [AS]) levels of LH2b, the predominant form of LH2 in this cell line, were established and cultured for 2 weeks, and collagen cross-links and precursor aldehydes in the matrices were analyzed.. In S clones tested, the ratio of dihydroxylysinonorleucine (DHLNL) to hydroxylysinonorleucine (HLNL) was significantly higher than the average of controls (76% and 140% increase, respectively), and the level of pyridinoline (Pyr) was elevated (100% and 150% increase, respectively). In contrast, when MC3T3-E1 cells were transfected with a LH2b antisense construct (AS clones), the DHLNL/HLNL ratios were significantly lower than that of controls (56% and 73% decrease, respectively), and Pyr was not detected. Furthermore, significant amounts of an aldol-derived cross-link, dehydrohistidinohydroxymerodesmosine, were produced ( approximately 0.3 mol/mol of collagen) in AS clones.. The data clearly show a critical role of LH2b in determining collagen cross-linking pathways, most likely through its action on telopeptidyl Lys residues.

Topics: 3T3 Cells; Amino Acids; Animals; Blotting, Western; Collagen; Desmosine; Dipeptides; DNA, Antisense; DNA, Complementary; Gene Expression; Genetic Vectors; Histidine; Immunoprecipitation; Isoenzymes; Lysine; Mice; Osteoblasts; Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase; Protein Processing, Post-Translational; Reverse Transcriptase Polymerase Chain Reaction; RNA; Transfection

The aim of this study was to detect crosslinks of collagen and elastin in formalin-fixed tissue, to perform quantification of these crosslinks, and to investigate the effects of formalin fixation on crosslink contents in human yellow ligament and cartilage. Pyridinoline (Pyr) is a stable and nonreducible crosslink of collagen. Pentosidine (Pen) is a senescent crosslink formed between arginine and lysine in matrix proteins, including collagen. Desmosine (Des) and its isomer isodesmosine (Isodes) are crosslinks specifically found in elastin. It is useful to measure crosslink contents of collagen and elastin as a way of investigating the properties of various tissues or their pathological changes. If it is possible to evaluate crosslinks of collagen and elastin in formalin-fixed tissues, we can investigate crosslinks in a wide variety of tissues. We used HPLC to compare the concentrations of Pyr, Pen, Des, and Isodes in the formalin-fixed tissues with their concentrations in the frozen tissues. Pyr and Pen were detected in both the formalin-fixed yellow ligament and the cartilage, and their concentrations were not significantly affected by or related to the duration of formalin fixation. Des and Isodes were detected in the formalin-fixed yellow ligament but in significantly lower amounts compared to the frozen samples. We concluded that crosslinks of collagen were preserved in formalin, but crosslinks of elastin were not preserved in it. The reason for this might be that formalin did not fix elastin tissues sufficiently or it destroyed, masked, or altered elastin crosslinks.

Topics: Aged; Aged, 80 and over; Amino Acids; Arginine; Cartilage; Chromatography, High Pressure Liquid; Collagen; Cross-Linking Reagents; Desmosine; Elastin; Formaldehyde; Freezing; Hip Joint; Humans; Isodesmosine; Ligaments; Lysine; Tissue Fixation

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

Keloid is a tissue with an excessive accumulation of collagen. In this study, we have partially characterized post-translational modifications of type I collagen in human keloid in order to pursue their potential involvement in this pathology. The levels of lysyl hydroxylation of the helical portions of alpha 1 and alpha 2 chains of type I collagen in keloid were significantly higher than those of normal, while the levels of prolyl hydroxylation were identical between these two groups. The contents of the major reducible cross-links in dermal collagen, dehydro-hydroxylysinonorleucine and dehydro-histidinohydroxymero-desmosine, were both significantly higher in keloids (up to sixfold) than those of normal. In addition, significant amounts of hydroxylysine-aldehyde derived cross-links that are characteristic of skeletal tissue collagens, dehydro-dihydroxylysinonorleucine (about 0.3 mole/mole of collagen) and pyridinoline (about 0.1 mole/mole of collagen), were found in keloids. These results indicate that keloid-forming cells are phenotypically different from those in normal dermis and that the collagen produced is highly cross-linked. The increased cross-linking provides the fibrils with more stability that may result in an accumulation of collagen.

Topics: Adult; Amino Acids; Collagen; Cross-Linking Reagents; Desmosine; Dipeptides; Histidine; Humans; Hydroxylation; Hydroxylysine; Hydroxyproline; Keloid; Middle Aged; Protein Processing, Post-Translational; Protein Structure, Secondary; Skin

Collagen and elastin fibres are of major importance in providing the aorta with tensile strength and elasticity. The presence of cross-links in collagen and elastin is essential for the mechanical stability of collagen and elastin fibres. beta-aminopropionitrile (BAPN) reduces the formation of cross-links by inhibiting the enzyme lysyloxidase. Young rats were injected with BAPN to inhibit the formation of cross-links, and the changes in the biomechanical and biochemical properties of the thoracic aorta were studied. The biomechanical analyses of aortic samples from BAPN-treated rats showed a significantly increased diameter (1.64 +/-0.02 mm), a significantly reduced maximum load (1.08+/-0.08 N), and a significantly reduced maximum stiffness (3.34+/-0.10 N) compared with controls (1.57+/-0.02 mm, 1.55+/-0.04 N and 4.49 +/-0.14 N, respectively). No changes in the concentrations of collagen and elastin were found. The content of pyridinoline, a mature collagen cross-link, was significantly decreased by 49% in the BAPN-treated group compared with controls. No changes in the concentration of desmosine + isodesmosine, the major cross-links of elastin. were found. The present study shows that cross-links are essential in providing mechanical stability of the aorta. Even a partial inhibition of the cross-linking processes results in a destabilisation of the aortic wall with increased diameter and reduced strength and stiffness.

Topics: Aging; Amino Acids; Animals; Aorta; Collagen; Desmosine; Elasticity; Elastin; Female; Rats; Rats, Wistar; Structure-Activity Relationship

Non-invasive markers of liver fibrosis have great potential for both the diagnosis and therapy of liver disease and cirrhosis. The aim of this study was to evaluate the potential of urinary amino acids desmosine (DES) and isodesmosine (IDES) derived from the breakdown of elastin and hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) derived from fibrillar collagen in diagnosing chronic liver disease.. We studied 48 patients with chronic liver disease who had varying degrees of liver fibrosis, graded 0-6 using a modified Knodell score, and 20 control subjects without liver disease. Urinary DES (microg/g creatinine) and HP (nmol/mmol creatinine) were measured by an isotope dilution, high performance liquid chromatography method. For liver disease patients, aminoterminal propeptide of type III procollagen (PIIINP) and alanine aminotransferase were determined. The urine and serum markers were correlated to degree of fibrosis and inflammation on liver biopsies. Differences between groups were analyzed by ANOVA and multiple linear regression was applied to determine independence of variables. Sensitivity, specificity and receiver operating curves were derived for each marker.. In the 17 patients with liver fibrosis score of 5-6, mean urinary DES, IDES, HP and LP were all significantly greater than in the control group (p<0.05). Urinary DES and IDES correlated best with fibrosis score, r=0.61 for both markers. The correlation coefficient between serum PIIINP and fibrosis score was 0.47. Urinary DES and HP each had an overall diagnostic accuracy of 77% for fibrosis. Combining markers improved accuracy to over 80%. No correlation was seen between the urinary markers and inflammation scores.. Urinary DES and HP are potentially useful clinical markers for liver fibrosis, especially when used in combination or in association with PIIINP.

Topics: Adult; Amino Acids; Desmosine; Female; Humans; Liver Cirrhosis; Male; Middle Aged; Peptide Fragments; Procollagen

It is well known that the elastic property of human aorta decreases gradually with age. Since the cross-linking structures are responsible for this elasticity, age-related changes of cross-linking amino acids in human aorta were studied using a high-performance liquid chromatography (HPLC). Non-atherosclerotic areas of thoracic aorta of 27 autopsy cases which had no particular aortic disease were obtained. After acid hydrolysis, SEP-PAK silica-gel column and Fe3+/activated charcoal column pretreatment were carried out for analysis of desmosine (DES), isodesmosine (ISDES), neodesmosine (NEO), oxodesmosine (OXO) and isooxodesomosine (ISOXO), and for analysis of aldosine (ALD), respectively. These prepared samples were applied to the reversed-phase HPLC column. We also analyzed pyridinoline (PYR), a major cross-linking amino acid of collagen as an index of fibrosis. All cross-linking amino acids of elastin rapidly increased in infancy and then gradually decreased with age. In the middle- and old-age, the amount of OXO showed marked variety. PYR was little detected at 0-year-old, and then gradually increased with age. The crosslinks of elastin were rapidly formed in childhood and then decreased with age. These findings suggest that the relative increase of NEO, OXO or ISOXO to DES and ISDES is associated with age-related weakening and/or damage of elastin, and that the gradual shift from elastin- to collagen-dominant state is a possible cause of the loss of elasticity and the gain of stiffness in the aging aorta.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Aging; Amino Acids; Aorta, Thoracic; Autopsy; Child; Child, Preschool; Chromatography, High Pressure Liquid; Cross-Linking Reagents; Desmosine; Elasticity; Elastin; Humans; Infant; Infant, Newborn; Isodesmosine; Middle Aged; Muscle Development; Muscle, Smooth, Vascular; Piperidines; Pyridines

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

It is hypothesized that emphysema develops in some severely alpha 1-antitrypsin (AAT)-deficient persons because endogenous elastases are not adequately controlled by AAT, and accelerated elastin degradation occurs. It is not known whether augmentation therapy with AAT diminishes degradation of lung elastin in severely deficient persons with lung disease. Two severely deficient, PiZ patients were studied, a 63-year-old never-smoking woman with bronchiectasis and a 41-year-old smoking man with emphysema. Urinary desmosine (DES) was determined before and after augmentation therapy with AAT, 260 mg/kg/month. Mean +/- SEM pretreatment urinary DES was elevated in both patients, 19.7 +/- 0.9 (n = 2) and 10.8 +/- 0.2 (n = 2) micrograms/g creatinine, respectively, compared to normal values of 7.5 +/- 0.3 (n = 22) micrograms/g creatinine. Following augmentation therapy, urinary DES values decreased 40 and 36%, respectively, to 11.9 +/- 0.3 (n = 8) and 6.9 +/- 0.4 (n = 7) microgram/g creatinine (p < 0.05). We conclude that monthly AAT augmentation therapy decreased DES excretion in the urine of these PiZ patients. We speculate that since there was lung disease in both patients, a decrease in degradation of lung elastin is the most likely explanation for this observation.

Topics: Adult; alpha 1-Antitrypsin; alpha 1-Antitrypsin Deficiency; Amino Acids; Bronchiectasis; Desmosine; Elastin; Emphysema; Female; Humans; Isodesmosine; Lung; Male; Middle Aged; Smoking

To help validate the use of urinary desmosine (DES), isodesmosine (IDES), and hydroxylysyl pyridinoline (HP) as specific markers of host elastin and collagen degradation, respectively, a study was carried out on the effect of dietary elastin and collagen on urinary DES, IDES, and HP. Ingestion of a meal of calf ligamentum nuchae containing 33 g elastin, 500 mg DES, and 400 mg IDES produced a 10-fold increase in urinary DES and an 8-fold increase in IDES. The urinary DES values remained elevated for more than 10 days following the ingestion. We estimate that about 0.3 mg, or < 0.1%, of the ingested DES was excreted in the urine. Since ligamentum nuchae is not a usual ingredient of human diets, we also determined whether a more typical source and amount of DES, IDES, and HP might affect urinary DES, IDES, or HP values. Lean ground beef (454 g) was ingested. Our analysis showed that this meal contained 4 mg DES, 2 mg IDES, and 0.9 mg HP. The meat-rich diet caused a significant increase of 16 and 34% in the creatinine and DES content of the urine, respectively. When DES, IDES, and HP values were normalized for the urine creatinine content, diet had no effect on the measured amounts. The baseline values (mean +/- SE) for the volunteers before ingestion of the beef were 8.3 +/- 0.7 micrograms DES/24 h, 8.3 +/- 0.6 micrograms IDES/24 h, and 340 +/- 48 nmol HP/24 h; 5.7 +/- 0.5 micrograms DES/g creatinine, 5.6 +/- 0.4 micrograms IDES/g creatinine, and 26.9 +/- 2.2 nmol HP/mmol creatinine.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Amino Acids; Analysis of Variance; Animals; Bias; Biomarkers; Cattle; Chromatography, High Pressure Liquid; Collagen; Creatinine; Desmosine; Diet; Dietary Proteins; Elastin; Humans; Isodesmosine; Male; Meat; Reproducibility of Results

Inhibition ELISA assay was used to examine the cross-reaction of the polyclonal anti-desmosine antiserum produced in rabbit against molecules possessing a "pyridinium ring" as their core structure i.e. isodesmosine, pentasine, pyridinoline and 2'-deoxypyridinoline, highly purified with column chromatography, and structurally unrelated substances, i.e. cysteic acid, taurine and 2-aminopyridine (core structure of desmosine). No cross-reaction was observed to the pyridinoline, 2'-deoxypyridinoline possessing "pyridinium ring" and derived from collagen cross-links, structurally unrelated cysteic acid and taurine, nor core structure of 2-aminopyridine. The antiserum specifically recognized the molecules derived from the elastin cross-links. Using the ELISA assay system with antisera and amino acids analysis, 10 micrograms of desmosine were extracted from 1.0 mg of the hydrolysate of commercial elastin.

Topics: Amino Acids; Animals; Antibodies; Antibody Specificity; Cross Reactions; Desmosine; Elastin; Enzyme-Linked Immunosorbent Assay; Rabbits

The wet weight of the rat uterus increased 8-fold during pregnancy and fell by 70% within 5 days postpartum. Uterine collagen increased about 5-fold during pregnancy and also fell by 70% within 5 days. The crosslink pyridinoline remained constant at 0.28 mole/mole collagen at every time point, with the possible exception of 11-12 days of pregnancy. The pyridinoline link can therefore form within the short time span of a few days, a feature presumed to be necessary to maintain the full mechanical strength of the uterus during labor. Uterine elastin increased about 8-fold during pregnancy, but the desmosines did not keep pace and fell from a normal value of 1.43 mole/mole elastin to a low of 0.89 at term. Moreover, elastin content reached a maximum several days prior to parturition and then declined continuously to 5 days postpartum. During this decline there was a selective loss of the poorly crosslinked elastin. The desmosines cannot be used as a direct measure of uterine elastin content, because of their continuously changing levels. Desmosines and pyridinoline were measured both by ELISA and by the amino acid analyzer. The two methods gave almost identical results when elastin and collagen were first separated from each other.

Topics: Amino Acids; Animals; Collagen; Desmosine; Elastin; Female; Organ Size; Pregnancy; Pregnancy, Animal; Rats; Rats, Inbred Strains; Uterus

The cross-links histidinoalanine (HA); pyridinoline (Pyr); desmosine (Des); and isodesmosine (Ides) in human atherosclerotic aortas were studied. Only HA showed a significant increase in calcified aortas, with a high concentration in the insoluble "mineralized" fraction, which was separated out after treatment of tissues with pronase E. The cross-links composition was similar among "mineralized" fractions prepared from tissues of varying degrees of calcification: values were 2.40; 0.10; 0.17; and 0.16 moles per 1000 moles of amino acid residues for HA; Pyr; Des; and Ides, respectively. The findings suggest that the HA-containing peptide may play an important role in the calcification process of aortic tissues.

Topics: Amino Acids; Aorta; Arteriosclerosis; Calcinosis; Cross-Linking Reagents; Desmosine; Dipeptides; Humans; Isodesmosine

Topics: Aged; Aging; Amino Acids; Aorta; Chromatography, High Pressure Liquid; Desmosine; Dipeptides; Humans; Isodesmosine; Peptide Fragments; Peptide Hydrolases; Proteins