Expression of tropomyosin 2 in aortic dissection tissue / 中华心血管病杂志

Objective: To investigate the expression pattern of tropomyosin 2(TPM2) in aorta of patients with aortic dissection and explore its clinical implication. Methods: Thirteen cases with acute type A aortic dissection(TAAD) diagnosed by transabdominal aortic angiography from 2015 in Tongji Hospital were included. During the operation, the aortic wall tissues of these patients were collected. Ten patients with heart transplantation were selected as control group, and normal aortic wall tissues were taken. The hematoxylin-eosin (HE) and Verhoeff's Van Gieson (EVG) staining were performed to observe the morphological changes of aorta. The mRNA expression level of TPM2 was measured by real-time fluorescent quantitative-PCR, and the protein levels of TPM2 were detected by Western blot and immunohistochemical staining. Image The J software was used to collect the optical density values of each point on the image, obtain the integrated optical density(IOD) value, and calculate the average density(%, IOD/area of the target distribution area). Results: HE and EVG staining revealed medial degeneration and broken elastic fiber in aorta of TAAD patients. The mRNA expression levels of TPM2 were significantly upregulated in aorta of TAAD patients as compared to the control group (P<0.05), so as the TPM2 protein expression levels ((9.73±1.20)% vs. (0.11±0.04)%, P<0.05). And TPM2 was mainly expressed in cytoplasm. Conclusion: The increased expression of TPM2 in TAAD patients hints that TPM2 might be involved in the pathogenesis of aortic dissection.

Aneurismas da Aorta Torácica: Avaliação Genética e de Imagem para Cirurgias Eletivas / Thoracic Aortic Aneurysm: Genetic and Image Evaluation for Elective Surgeries

Evidências mostram que variações genéticas de um único gene, denominadas “mutações genéticas”, predispõem indivíduos aos aneurismas e dissecções da aorta e seus ramos. Com a identificação dessas mutações, diretrizes sugerem o manuseio no diagnóstico, o momento ideal para a correção cirúrgica e a identificação de indivíduos sob alto risco de ruptura ou dissecção e suas respectivas famílias. Essas mutações podem se apresentar de forma “sindrômica”, com identificação fenotípica simples ou apresentação “familiar”. Nos indivíduos sem características fenotípicas, a ocorrência familiar da mutação genética deve ser investigada através da história familiar, exames de imagem e através de marcadores genéticos.

Evidence shows that genetic variations in a single gene called gene mutations predispose individuals to aneurysms and dissections of the aorta and its branches. With the identification of these mutations, guidelines suggest that diagnosis management is the idealtime for surgical correction and the identification of individuals at high risk of rupture or dissection and their families. These mutations may be present in a syndromic way with simple phenotypic identification or family presentation. In individuals without phenotypic characteristics, familial occurrence of genetic mutation should be investigated through the family history, imaging scansand through genetic markers.

Doenças da aorta torácica: alterações morfológicas e o papel das metaloproteínases na gênese dos aneurismas e das dissecções / Morphologic alterations in diseases of the thoracic aorta: the role of metalloproteases in aneurysms and aortic dissections

Alterações da matriz extracelular (MEC), cujos principais componentes são os proteoglicanos, o colágeno e o tecido elástico, têm papel proeminente nas doenças da aorta. Proteoglicanos são uma família de macromoléculas com esqueleto proteico e cadeias laterais de um tipo de açúcares, os glicosaminoglicanos. O sistema elástico tem um componente microfibrilar, constituído por proteínas tais como fibrilina e emilina, sobre as quais elastina se deposita, moldando as fibras elásticas. Colégenos, principalmente dos tipos I e III, são as proteínas estruturais mais importantes nos corpos dos mamíferos. Destruição do tecido elástico é considerada o mais importante fator subjacente a todos os tipos de aneurisma. As dissecções aórticas e os aneurisma de aorta ascedente (AAAsc) têm as mesmas alterações histopatológicas na túnica média: fragmentação das fibras elásticas, acúmulos de material mucoide (proteoglicanos) cuja natureza real não está ainda esclarecida , e um possível decréscimo na população de células musculares lisas. O colágeno está diminuído nessas doenças, em toda a parede nos AAAsc e na metade externa na dissecções. Na arterite de Takayasu, a inflamação e a destruíção do tecido tecido elástico...

Alterations in the extracellular matrix (ECM), whose main components are proteoglycans, collagen and the elastic tissue play a prominent role in aortic diseases. Proteoglycans are a family of macromolecules with a proteic core and lateral chains of highly charged sugars, the glycosaminoglycans. The elastic system has a microfibrillar component, constituted by many proteins such as fibrillin and emilin, over which elastin deposits in order to mold elastic sheets. Collagens, mostly types I and III, are the most important structural proteins in mammal bodies. Elastic tissue destruction is considered the most important factor related to all types of aneurysms. Aortic dissections and ascending aortic aneurysms (AscAA) share their histopathological features, on the medial layer: fragmentation of elastic tissue, deposits of mucoid (proteoglycan) content whose actual constitution is not clear yet, and a probable decrease in the population of smooth muscle cells. Collagen is diminished in these conditions, in the whole wall in AscAA and in the external half only in dissections. In Takayasu’s arteritis, the inflammation and elastic destruction area are associated to a dense fibrosis that causes stenosis in arterial lumen.

Cystic medial necrosis: pathological findings and clinical implications / Necrose cística da média: manifestações patológicas com implicações clínicas

Cystic medial necrosis (CMN) is a disorder of large arteries, in particular the aorta, characterized by an accumulation of basophilic ground substance in the media with cyst-like lesions. CMN is known to occur in certain connective tissue diseases such as Marfan syndrome, Ehlers-Danlos syndrome, and annuloaortic ectasia, which usually result from degenerative changes in the aortic wall. The relationships between CMN and congenital heart defects as well as other disorders have been evidenced. The mechanisms are still controversial, even though many molecular studies have been conducted. The aim of the present article is to provide a comprehensive overview of the CMN lesion in terms of pathologic features, clinical implications and etiologies based on molecular research results.

A necrose cística da média (NCM) é uma desordem das grandes artérias, em particular a aorta, caracterizada por acúmulo de substância basofílica na camada média com lesões císticas-símile. É sabido que a NCM ocorre em certas doenças do tecido conjuntivo tal como síndrome de Marfan, síndrome de Ehlers-Danlos, e ectasia ânulo-aórtica, que normalmente resulta de mudanças degenerativas na parede aórtica. A relação entre NCM e defeitos congênitos do coração, assim como outras desordens, tem sido evidenciada. Os mecanismos são ainda controversos, embora muitos estudos moleculares tenham sido conduzidos. O objetivo do presente artigo é fornecer uma visão geral da NCM em termos de características patológicas, implicações clínicas e etiologia baseada em resultados de pesquisa molecular.