Ultraviolet light- and ozone-induced changes in pyridinoline, a trisubstituted 3-hydroxypyridinium crosslink of collagen

Fujimori, Eiji

doi:10.1016/0167-4838(85)90015-9

Cited by 11 publications

(4 citation statements)

References 15 publications

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“…Both UV lamps in the instrument used in the study produced UV light at 297 nm, which is known to produce the maximal rate of Pyr photolysis in acid solution [8]. The high rate of denaturation of Pyr in the aqueous standard was in agreement with that demonstrated by previous workers [7,8]. The increased Pyr photolysis of the aqueous standards compared with urine may be attributed to the fact that the intensity of incident UV light is higher under the same conditions.…”

Section: Discussionsupporting

confidence: 83%

“…Although the exact mechanism involved in the generation of the free and conjugated fractions following collagen degradation is not fully understood, their measurement has provided a specific non-invasive estimate of bone resorption in clinical studies of bone turnover. Previous studies have shown that aqueous samples of Pyr are stable under acid conditions and undergo photolytic oxidation when exposed to UV light [6][7][8], and the aromatic ring of Pyr present in bovine articular cartilage collagen is cleaved by UV irradiation [9,10]. In clinical studies of bone turnover, the measurements of Pyr and Dpyr in serum and urine are used as estimates of bone resorption [11].…”

Section: Introductionmentioning

confidence: 99%

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To determine the effects of ultraviolet light, natural light and ionizing radiation on pyridinium cross‐links in bone and urine using high‐performance liquid chromatography

Colwell¹,

Hamer

Blumsohn³

et al. 1996

Eur J Clin Investigation

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The aims of the study were to characterize the denaturation of urinary free and conjugated pyridinoline (Pyr) and deoxypyridinoline (Dpyr) on exposure to ultraviolet (UV) and natural light at different pH levels and to study the effects of X- and gamma-irradiation on Pyr and Dpyr in urine and in the mineralized and non-mineralized compartments of human bone. Urine samples from six normal subjects, adjusted to pH 3.0, 7.0 and 9.0 were exposed to UV light for up to 3 days. Urine collections (2 mL and 24 h) from three subjects, pH adjusted to 1.0, 2.0, 3.0, 4.0 and 5.0, were exposed to natural light for up to 1 day. Urine samples and bone slices from seven human cadaveric femurs were irradiated with increasing doses of X-rays (0-100 Gy) and high-dose gamma-radiation (28 kGy). Mineralized and non-mineralized bone were separated using a modification of a published method employing heat denaturation followed by trypsin hydrolysis and analysed for Pyr, Dpyr and hydroxyproline (Hypro). The rate of UV photolysis of urinary Pyr and Dpyr increased with pH and was faster in the free fraction (after 3 days' exposure: free Pyr and Dpyr at pH 7.0 vs. 9.0, P < 0.05, conjugated pH 3.0 vs. 9.0, P < 0.05). Exposure to natural light for 3 h did not significantly decrease urinary Pyr and Dpyr in either sample collections, but levels were reduced in the 2-mL aliquots after exposure for 1 day (P < 0.05). X-irradiation of urine and bone did not affect Pyr and Dpyr. Pyr content was similar in both bone compartments (Pyr/ Hypro = 0.12 +/- 0.004), but Dpyr was higher in the non-mineralized compartment (Dpyr/Hypro = 0.047 +/- 0.002 vs. 0.038 +/- 0.002, P < 0.001). UV light and gamma-irradiation result in denaturation of pyridinium cross-links in urine. These cross-links are present in both the mineralized and non-mineralized bone compartments but are not affected by the doses of gamma-irradiation that denature these cross-links in urine.

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Section: Discussionsupporting

confidence: 83%

Section: Introductionmentioning

confidence: 99%

To determine the effects of ultraviolet light, natural light and ionizing radiation on pyridinium cross‐links in bone and urine using high‐performance liquid chromatography

Colwell¹,

Hamer

Blumsohn³

et al. 1996

Eur J Clin Investigation

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“…The continuous sensitization activity observed with pyridinoline exposed to even high doses of SSL irradiation suggested a remarkable photostability of the material. We therefore examined the photostability of our pyridinoline preparation exposed to increasing doses of SSL irradiation using UV and £uorescence spectroscopy ( with formation of photolysis products that retain photosensitization activity (Fujimoto, 1985;Meddah et al, 2000). Next, the photodynamic action of ECM protein-derived pyridinium cross-links on proliferation of cultured human CF3 ¢broblasts was examined (Fig 8).…”

Section: Resultsmentioning

confidence: 99%

Proteins of the Extracellular Matrix Are Sensitizers of Photo-oxidative Stress in Human Skin Cells

Wondrak

Roberts

Cervantes-Laurean

et al. 2003

Journal of Investigative Dermatology

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Sensitized production of reactive oxygen species after photo-excitation of endogenous chromophores is thought to contribute to skin photo-oxidative stress. Here we present experimental evidence in support of a potential role of extracellular matrix proteins as skin photosensitizers. Human and bovine type I collagen and elastin sensitized of hydrogen peroxide generation upon irradiation with solar simulated light or ultraviolet A. Induction of intracellular oxidative stress by extracellular matrix-protein sensitization was demonstrated by flow cytometric analysis of fibroblasts preloaded with the intracellular redox dye dihydrorhodamine 123 and exposed to pre-irradiated type I collagen. Pre-irradiated collagen and elastin induced pronounced inhibition of proliferation in cultured keratinocytes and fibroblasts, which was reversed by antioxidant or catalase treatment and reproduced by exposure to concentrations of H2O2 formed during extracellular matrix-protein irradiation. In fibroblasts, chromosomal DNA damage as a consequence of collagen-sensitized H2O2 formation was demonstrated using a single cell electrophoresis assay. The enzymatic cross-links pyridinoline and desmosine were examined as candidate sensitizer chromophores contained in collagen and elastin, respectively. Pyridinoline, but not desmosine, sensitized light-driven H2O2 production and inhibition of fibroblast proliferation. Our results support the hypothesis that extracellular matrix proteins play a functional role in skin photoaging and carcinogenesis by sensitization of photo-oxidative damage.

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“…III A cannot act as validation standards since multiple parameters contribute to the lifetime of a biological compound (e.g., excitation and detection wavelength, prolonged sample exposure to laser radiation, humidity, and age of sample), they have been broadly studied and reported in the literature. 1 In addition, the fluorescence of biological compounds has contributions from multiple fluorophores, 1,40,41 therefore, the 10% difference in the elastin lifetimes measured from two different channels can be expected. The measurements reported in Table II were similar to the ones reported in Refs.…”

Section: System Time-domain Characteristicsmentioning

confidence: 99%

Design and evaluation of a device for fast multispectral time-resolved fluorescence spectroscopy and imaging

Yankelevich

Liu

et al. 2014

Review of Scientific Instruments

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The application of time-resolved fluorescence spectroscopy (TRFS) to in vivo tissue diagnosis requires a method for fast acquisition of fluorescence decay profiles in multiple spectral bands. This study focusses on development of a clinically compatible fiber-optic based multispectral TRFS (ms-TRFS) system together with validation of its accuracy and precision for fluorescence lifetime measurements. It also presents the expansion of this technique into an imaging spectroscopy method. A tandem array of dichroic beamsplitters and filters was used to record TRFS decay profiles at four distinct spectral bands where biological tissue typically presents fluorescence emission maxima, namely, 390, 452, 542, and 629 nm. Each emission channel was temporally separated by using transmission delays through 200 μm diameter multimode optical fibers of 1, 10, 19, and 28 m lengths. A Laguerreexpansion deconvolution algorithm was used to compensate for modal dispersion inherent to large diameter optical fibers and the finite bandwidth of detectors and digitizers. The system was found to be highly efficient and fast requiring a few nano-Joule of laser pulse energy and <1 ms per point measurement, respectively, for the detection of tissue autofluorescent components. Organic and biological chromophores with lifetimes that spanned a 0.8-7 ns range were used for system validation, and the measured lifetimes from the organic fluorophores deviated by less than 10% from values reported in the literature. Multi-spectral lifetime images of organic dye solutions contained in glass capillary tubes were recorded by raster scanning the single fiber probe in a 2D plane to validate the system as an imaging tool. The lifetime measurement variability was measured indicating that the system provides reproducible results with a standard deviation smaller than 50 ps. The ms-TRFS is a compact apparatus that makes possible the fast, accurate, and precise multispectral time-resolved fluorescence lifetime measurements of low quantum efficiency sub-nanosecond fluorophores. © 2014 AIP Publishing LLC. [http://dx

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Ultraviolet light- and ozone-induced changes in pyridinoline, a trisubstituted 3-hydroxypyridinium crosslink of collagen

Cited by 11 publications

References 15 publications

To determine the effects of ultraviolet light, natural light and ionizing radiation on pyridinium cross‐links in bone and urine using high‐performance liquid chromatography

To determine the effects of ultraviolet light, natural light and ionizing radiation on pyridinium cross‐links in bone and urine using high‐performance liquid chromatography

Proteins of the Extracellular Matrix Are Sensitizers of Photo-oxidative Stress in Human Skin Cells

Design and evaluation of a device for fast multispectral time-resolved fluorescence spectroscopy and imaging

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