The extracellular matrix of the human aortic wall: Ultrastructural observations by FEG-SEM and by tapping-mode AFM

Raspanti, Mario; Protasoni, Marina; Manelli, A.; Guizzardi, Stefano; Mantovani, Vittorio; Sala, A.

doi:10.1016/j.micron.2005.06.002

Cited by 34 publications

(24 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this case, the absence of fluorescence in collagen gels is not irrelevant; on the contrary, this observation helps us to justify our results because the most important part of tissue fluorescence could be assigned to the elastin content. A recent study based on electron microscopy [31] allows very detailed observations of la- Nevertheless, videomicroscopy allows a global observation of samples and in order to have more detailed information the use of confocal fluorescence microscopy was necessary. This approach permits observation of elastic fibers present in the aortic wall, confirming the data obtained by infrared imaging and supporting the observation that degradation of elastic fibers is the main mechanism implied in the aneurysm development.…”

Section: Fluorescence Microscopies Resultsmentioning

confidence: 99%

FTIR protein secondary structure analysis of human ascending aortic tissues

Bonnier

Rubin

Debelle

et al. 2008

Journal of Biophotonics

View full text Add to dashboard Cite

Journal of BIOPHOTONICSThe advent of moderate dilatations in ascending aortas is often accompanied by structural modifications of the main components of the aortic tissue, elastin and collagen. In this study, we have undertaken an approach based on FTIR microscopy coupled to a curve-fitting procedure to analyze secondary structure modifications in these proteins in human normal and pathological aortic tissues. We found that the outcome of the aortic pathology is strongly influenced by these proteins, which are abundant in the media of the aortic wall, and that the advent of an aortic dilatation is generally accompanied by a decrease of parallel b-sheet structures. Elastin, essentially composed of b-sheet structures, seems to be directly related to these changes and therefore indicative of the elastic alteration of the aortic wall. Conventional microscopy and confocal fluorescence microscopy were used to compare FTIR microscopy results with the organization of the elastic fibers present in the tissues. This in-vitro study on 6 patients (three normal and three pathologic), suggests that such a spectroscopic marker, specific to aneurismal tissue characterization, could be important information for surgeons who face the dilemma of moderate aortic tissue dilatation of the ascending aortas.Infrared spectroscopy and imaging was applied to analyse Human thoracic ascending aortas with the aim to highlight the protein secondary structure reorganisation after an aneurism outcome. We used a curve-fitting procedure to visualise modifications in the protein spectral profile where alteration of b structures in pathological aortas could be detected. Our spectroscopic observations on tissue sections corroborated with confocal fluorescence microscopy clearly demonstrating that elastic fibres of aortic wall are strongly altered. Elastin appears as the privileged target during the pathological process.

show abstract

Section: Fluorescence Microscopies Resultsmentioning

confidence: 99%

FTIR protein secondary structure analysis of human ascending aortic tissues

Bonnier

Rubin

Debelle

et al. 2008

Journal of Biophotonics

View full text Add to dashboard Cite

show abstract

“…In particular, we used here the so-called cluster-assembled thin gold films. Cluster-assembled materials are characterised at the nanoscale by granularity and porosity mimicking those of recently observed extracellular matrix structure [5,6] and by an excellent biocompatibility [5]. Regarding flat gold films, a careful analysis of SE difference spectra allowed to extract information on the state of the adsorbed protein from the examination of the energy position and lineshape of near-UV molecular absorptions, in particular of the intense Soret band at about 410 nm.…”

Section: Introductionmentioning

confidence: 99%

Yeast Cytochrome c Monolayer on Flat and Nanostructured Gold Films Studied by UV–Vis Spectroscopic Ellipsometry

et al. 2011

View full text Add to dashboard Cite

Spectroscopic ellipsometry (SE) has been used to investigate the adsorption of yeast cytochrome c (YCC) on gold films. YCC is a prototypical molecular system to evaluate the sensitivity and reliability of optical methods in probing conformational changes upon adsorption at surfaces. Measurements have been performed in situ in aqueous solutions at room temperature. We have applied to monolayer-thick YCC films the same scheme of analysis of SE spectra used in our recent works on thiolate self-assembled monolayers on gold, exploiting the so-called δ and δ difference spectra. A comparison between δ and δ spectra obtained from YCC adsorption on flat and cluster-assembled nanostructured gold films, obtained by supersonic cluster beam deposition is proposed. For both kinds of substrate δ and δ , difference spectra show well-defined features related to molecular optical absorptions typical of the so-called heme group, in particular the Soret band at about 410 nm. These features appear in the same position found for molecules in solution, suggesting that YCC native conformation is maintained upon adsorption also in the case of a substrate with typical roughness at the nanoscale.

show abstract

“…It has been suggested that the fibril diameter may be related to the amount of collagen types III and V [29,30], but not all authors agree [27] and other mechanisms may be at work. A variety of high-resolution morphological techniques, including freeze-fracture [19][20][21]31] and atomic force microscopy [32,33], have shown that the microfibrillar subunits of these fibrils form an evident right-handed helix, with a winding angle of approximately 17 • .…”

Section: Introductionmentioning

confidence: 99%

Different Crimp Patterns in Collagen Fibrils Relate to the Subfibrillar Arrangement

Franchi

Raspanti

Dell’Orbo

et al. 2008

Connective Tissue Research

Self Cite

View full text Add to dashboard Cite

Collagen fibril ultrastructure and course were examined in different connective tissues by PLM, SEM, TEM, and AFM. In tendons, collagen fibrils were large and heterogeneous with a straight subfibrillar arrangement. They ran densely packed, parallel, and straight changing their direction only in periodic crimps where fibrils showed a local deformation (fibrillar crimps). Other tissues such as aponeurosis, fascia communis, skin, aortic wall, and tendon and nerve sheaths showed thinner uniform fibrils with a helical subfibrillar arrangement. These fibrils appeared in parallel or helical arrangement following a wavy, undulating course. Ligaments showed large fibrils as in tendon, with fibrillar crimps but less packed. Thinner uniform-sized fibrils also were observed. Fibrillar crimps seem to be related to the subfibrillar arrangement being present only in large fibrils with a straight subfibrillar arrangement. These stiffer fibrils respond mainly to unidirectional tensional forces, whereas the flexible thinner fibrils with helical subfibrils can accommodate extreme curvatures without harm, thus responding to multidirectional loadings.

show abstract

The extracellular matrix of the human aortic wall: Ultrastructural observations by FEG-SEM and by tapping-mode AFM

Cited by 34 publications

References 17 publications

FTIR protein secondary structure analysis of human ascending aortic tissues

FTIR protein secondary structure analysis of human ascending aortic tissues

Yeast Cytochrome c Monolayer on Flat and Nanostructured Gold Films Studied by UV–Vis Spectroscopic Ellipsometry

Different Crimp Patterns in Collagen Fibrils Relate to the Subfibrillar Arrangement

Contact Info

Product

Resources

About