RESUMO
The mitochondrial genome of Mystacoleucus marginatus (Cypriniformes, Cyprinidae) has been sequenced. The total sequence is 16,611 bp in size with 56.67% AT content. It contains 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs and 1 putative control region. The gene content and organization are similar to that of most other vertebrates. Most genes are encoded on the heavy strand except ND6 and eight tRNA genes on light strand. This molecular information will contribute to better understand its evolution and population genetics.
Assuntos
Cyprinidae/genética , Genoma Mitocondrial , Animais , Sequência de Bases , Códon de Iniciação/genética , Cyprinidae/classificação , Dados de Sequência Molecular , RNA Ribossômico/genética , RNA de Transferência/genética , Análise de Sequência de DNARESUMO
OBJECTIVES: This study aimed to investigate the roles of connective tissue growth factor (CTGF) and transforming growth factor-ß1 (TGF-ß1) in atrial fibrosis in patients with chronic atrial fibrillation. METHODS: Up to 40 cases involving simple mitral valve replacement surgery were divided into 2 groups: the chronic atrial fibrillation (cAF) group (n = 28) and the sinus rhythm group (n = 12). Echocardiography was used to measure the cardiac cavity size and analyze the cardiac function. Right atrial specimens were obtained during the operation. The collagen volume fraction in the atrial specimens was examined. The mRNA and protein levels of TGF-ß1, Smad3 and CTGF were also investigated. RESULTS: Compared with the sinus rhythm group, the cAF group had higher collagen content in the right atrial tissues. The mRNA and protein levels of TGF-ß1, Smad3 and CTGF were also significantly elevated in the cAF group (p < 0.05). The mRNA and protein levels of TGF-ß1 and CTGF in the cAF group correlated positively with the collagen volume fraction. The positive correlation between the expression of TGF-ß1 and CTGF was also demonstrated. CONCLUSIONS: CTGF is upregulated via the TGF-ß1/Smad pathway in the atrial myocardium of cAF patients. Furthermore, the TGF-ß1/Smad pathway may play an important role in the structural remodeling during atrial fibrosis.
Assuntos
Fibrilação Atrial/metabolismo , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Miocárdio/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Doença Crônica , Colágeno/metabolismo , Feminino , Átrios do Coração , Humanos , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Transdução de Sinais , Proteína Smad3/metabolismoRESUMO
OBJECTIVE: To investigate rapid atrial pacing (RAP) induced atrial ultrastructural changes and mRNA and protein expression changes of L-type calcium channel subunits and potassium channel Kv4.3 in a rabbit model. METHODS: Thirty-six rabbits were electrically paced at a frequency of 600 beats/min for durations ranging from 0 - 48 h via bipolar endocardial leads through surgical techniques. Ultrastructural changes of the atrium were observed through a transmission electron microscope (TEM), L-type calcium channel subunits and potassium channel Kv4.3 expressions at mRNA and protein levels were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. RESULTS: Atrial ultrastructure changes characterized by mitochondrial vacuolization, myofilament lysis, and glycogen accumulation were detected obvious at 3 h post pacing. Down-regulated mRNA expression of Ca(2+) channel beta1 and alpha1 subunits was observed 6 h post pacing, Kv4.3 mRNA down-regulation occurred 24 h post pacing, auxiliary subunit alpha2 was not affected by pacing. Protein expression of alpha1c subunit and potassium channel Kv4.3 paralleled their mRNA expression changes. CONCLUSION: RAP induced ultrastructural changes of the atrium and down-regulated mRNA and protein expressions of L-type calcium channel subunits and potassium channel Kv4.3 occurred thereafter in response to intracellular calcium overload induced by RAP.