Association between single nucleotide polymorphisms of tropoelastin gene and aortic dissection / 中南大学学报(医学版)

OBJECTIVES@#To evaluate the relation between single nucleotide polymorphisms (SNPs) of tropoelastin gene and aortic dissection (AD) via identifying SNPs in the tropoelastin gene, and to detect the level of tropoelastin mRNA, elastin and elastic fibers.@*METHODS@#The specimens of the AD group (@*RESULTS@#Seven SNP loci of the tropoelastin gene were detected in these samples. Among them, 5 SNP loci were polymorphic. The frequency of 3 SNP loci[rs2071307 (G/A), rs34945509 (C/T) and rs17855988 (G/C)] was significantly different between the AD group and the control group (all @*CONCLUSIONS@#The polymorphisms of rs2071307 (G/A), rs34945509 (C/T), and rs17855988(G/C) in the tropoelastin gene may eventually affect the synthesis of elastic fibers and they may play an important role in the occurrence of AD.

Elastic fiber regeneration in vitro and in vivo for treatment of experimental abdominal aortic aneurysm / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The pathological characteristics of abdominal aortic aneurysm (AAA) involved the regression of extracellular matrix (ECM) in aortic walls, especially elastic structure in medial layer. As the major structural protein of aorta, elastin contributes to the extensibility and elastic recoil of the vessels. We hypothesized that overexpression of elastin in vessel walls might regenerate the elastic structure of ECM, restore the elastic structure of the aneurysmal wall, and eventually lead to a reduction of aortic diameters (ADs) in an experimental model of AAA.</p><p><b>METHODS</b>Tropoelastin (TE) of Sprague Dawley (SD) rat was synthesized by reverse transcription polymerase chain reaction and used to construct adneviral vectors containing elastin precursor protein (AdTE-GFP). Cultured vascular smooth muscle cells (VSMCs) from aortas of male SD rats were transfected with AdTE-GFP, AdGFP, adenoviral vector (AdNull), and phosphate buffered saline (PBS). Immunofluorescence staining was performed to determine the expression of elastin in transfected cells. The expression of elastic fibers in ECM of VSMCs transfected with AdTE-GFP were detected by fluorescence microscopy and transmission electron microscopy (TEM) at 1, 3, and 5 days following gene transfer. The AAA vessel walls were infused with AdTE-GFP or an empty AdNull, or PBS directly into the aneurysmal lumen. ADs of the aneurysms were compared in infused aortas. Formation of new elastic fibers in vivo was assessed by hematoxylin and eosin, and elastic von-Giesson staining. Recombinant elastin-GFP in vivo was identified by immunohistochemical staining.</p><p><b>RESULTS</b>Elastic fibers were increased both in ECM of VSMC and in vessel walls after gene transfer. Histological studies revealed that the AdTE-GFP-transduced aortas had elastic fiber regeneration in the aneurysmal walls. The AdTE-GFP-transduced aortas showed a decreased AD (23.04% ± 14.49%, P < 0.01) in AAA vessel walls.</p><p><b>CONCLUSIONS</b>Elastic fibers have been successfully overexpressed both in vitro and in a rat model of AAA by a technique of gene transfer. The overexpression of elastic fibers within the aneurysmal tissue appeared to reverse the aneurysm dilatation in this model.</p>

A Case of Fibroelastolytic Papulosis on the Neck of a Young Man

Fibroelastolytic papulosis of the neck (FEPN) encompasses a spectrum of two disorders that were previously reported as pseudoxanthoma elasticum-like papillary dermal elastolysis (PXE-PDE) and white fibrous papulosis of the neck (WFPN). The clinical presentation of FEPN is asymptomatic to mildly pruritic whitish-yellow papules that may coalesce into cobblestone patterned plaques that resemble pseudoxanthoma elasticum (PXE). The histology is characterized by a decrease or loss of elastic fibers in the papillary dermis and this is sometimes accompanied by a minimal or nodular increase of dermal collagen fibers. We report here on a 28-year-old Korean man with asymptomatic, multiple, skin-colored to slightly yellowish, match-head sized, cobblestone-patterned papules on the neck, and these were histologically consistent with FEPN and the papules showed slightly increased dermal collagen associated with decreased and fragmented elastic fibers, elastin and tropoelastin. The pathogenesis of FEPN in this case might have been related with mild dermal inflammation, followed by fragmentation, elastolysis and increased dermal collagen.

Las fibras elásticas y el pulmón / The elastic fibers and the lung

La matriz extracelular (ME) del tejido conectivo pulmonar se diferencia en membranas basales y matriz intersticial. Esta última se constituye por un armazón de proteínas colagénicas fibrosas y de fibras elásticas amorfas, que están embebidas dentro de una sustancia basal viscoelástica compuesta por proteoglicanos y glicoproteínas. La ME le proporciona al pulmón sus propiedad mecánicas. Las colágenas proveen tensión, mientras que las fibras elásticas permiten el desarrollo de la expansión elástica, con la subsecuente recuperación característica de este órgano. Las fibras elásticas se constituyen por fibras amorfas de elastina polimérica combinada con ciertas glicoproteínas conocidas como microfibrillas, con proporciones variables según su estadio ontogénico. Este material amorfo constituye toda una malla que comprende un armazón continuo, por todo el pulmón, y en conexión estrecha con las fibras de colágena permite la actividad mecánica del pulmón. La elastina es una molécula altamente hidrofóbica, con una relación intron: exón de 15:1, sintetizada junto con un receptor que guía su polimerización en sitios determinados por las microfibrillas previamente depositadas