Structural variations of collagen in normal and pathological tissues: role of electron microscopy

Eyden, Brian P; Tzaphlidou, Margaret

doi:10.1016/s0968-4328(00)00045-7

Cited by 82 publications

(52 citation statements)

References 117 publications

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“…In a number of tumors, abnormal collagen fibril aggregates occur, manifesting themselves as wide variations in diameter and cross-sectional profile of the collagen fibrils. 24 A strong SHG signal is produced only by ordered structures, and analysis in terms of magnitude and angular dependence could be used as a method to study the structure of the extracellular matrix. Such analysis may be used to distinguish between normal and malignant tissue and to characterize the influence of treatment in tissues.…”

Section: Discussionmentioning

confidence: 99%

Quantification of the second-order nonlinear susceptibility of collagen I using a laser scanning microscope

et al. 2007

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Abstract. Characteristic changes in the organization of fibrillar collagen can potentially serve as an early diagnostic marker in various pathological processes. Tissue types containing collagen I can be probed by pulsed high-intensity laser radiation, thereby generating second harmonic light that provides information about the composition and structure at a microscopic level. A technique was developed to determine the essential second harmonic generation ͑SHG͒ parameters in a laser scanning microscope setup. A rat-tail tendon frozen section was rotated in the xy-plane with the pulsed laser light propagating along the z-axis. By analyzing the generated second harmonic light in the forward direction with parallel and crossed polarizer relative to the polarization of the excitation laser beam, the second-order nonlinear optical susceptibilities of the collagen fiber were determined. Systematic variations in SHG response between ordered and less ordered structures were recorded and evaluated. A 500m-thick z-cut lithiumniobate ͑LiNbO 3 ͒ was used as reference. The method was applied on frozen sections of malignant melanoma and normal skin tissue. Significant differences were found in the values of d 22 , indicating that this parameter has a potential role in differentiating between normal and pathological processes.

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Section: Discussionmentioning

confidence: 99%

Quantification of the second-order nonlinear susceptibility of collagen I using a laser scanning microscope

et al. 2007

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“…Second harmonic generation (SHG) is a secondorder nonlinear imaging method to visualize anisotropic biological structures lacking a center of symmetry, such as collagen [Georgiou et al, 2000;Campagnola et al, 2002;Zipfel et al, 2003;Strupler et al, 2007]. This technique is preferred to other methods established for collagen observation, like electron microscopy [Eyden and Tzaphlidou, 2001], X-ray diffraction [James et al, 1991] and histological analysis, since it provides high-resolution images with detailed information without photobleaching and extra staining.…”

Section: Introductionmentioning

confidence: 99%

Collagen Matrix Remodeling in Stented Pulmonary Arteries after Transapical Heart Valve Replacement

Ghazanfari¹,

Driessen-Mol²,

Hoerstrup

et al. 2016

Cells Tissues Organs

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The use of valved stents for minimally invasive replacement of semilunar heart valves is expected to change the extracellular matrix and mechanical function of the native artery and may thus impair long-term functionality of the implant. Here we investigate the impact of the stent on matrix remodeling of the pulmonary artery in a sheep model, focusing on matrix composition and collagen (re)orientation of the host tissue. Ovine native pulmonary arteries were harvested 8 (n = 2), 16 (n = 4) and 24 (n = 2) weeks after transapical implantation of self-expandable stented heart valves. Second harmonic generation (SHG) microscopy was used to assess the collagen (re)orientation of fresh tissue samples. The collagen and elastin content was quantified using biochemical assays. SHG microscopy revealed regional differences in collagen organization in all explants. In the adventitial layer of the arterial wall far distal to the stent (considered as the control tissue), we observed wavy collagen fibers oriented in the circumferential direction. These circumferential fibers were more straightened in the adventitial layer located behind the stent. On the luminal side of the wall behind the stent, collagen fibers were aligned along the stent struts and randomly oriented between the struts. Immediately distal to the stent, however, fibers on both the luminal and the adventitial side of the wall were oriented in the axial direction, demonstrating the stent impact on the collagen structure of surrounding arterial tissues. Collagen orientation patterns did not change with implantation time, and biochemical analyses showed no changes in the trend of collagen and elastin content with implantation time or location of the vascular wall. We hypothesize that the collagen fibers on the adventitial side of the arterial wall and behind the stent straighten in response to the arterial stretch caused by oversizing of the stent. However, the collagen organization on the luminal side suggests that stent-induced remodeling is dominated by contact guidance.

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“…In human beings, for instance, they are responsible for the integrity of skin, bone, cornea, tendons, teeth, cartilage, etc (Prockop, 1998). Consequently, alterations in these matrices, both at a molecular level or in their overall macroscopic organization, are correlated with different diseases (Eyden and Tzaphlidou, 2001). Therefore, three dimensional substrates representative of living tissues are needed in in vitro experiments in order to further understand the cellular or molecular processes in normal and pathological situations.…”

Section: Introductionmentioning

confidence: 99%

Dense tissue-like collagen matrices formed in cell-free conditions

et al. 2006

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Structural variations of collagen in normal and pathological tissues: role of electron microscopy

Cited by 82 publications

References 117 publications

Quantification of the second-order nonlinear susceptibility of collagen I using a laser scanning microscope

Quantification of the second-order nonlinear susceptibility of collagen I using a laser scanning microscope

Collagen Matrix Remodeling in Stented Pulmonary Arteries after Transapical Heart Valve Replacement

Dense tissue-like collagen matrices formed in cell-free conditions

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