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Cell Death Differ ; 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31685980


Zinc finger protein 422 (Zfp422) is a widely expressed zinc finger protein that serves as a transcriptional factor to regulate downstream gene expression, but until now, little is known about its roles in myogenesis. We found here that Zfp422 plays a critical role in skeletal muscle development and regeneration. It highly expresses in mouse skeletal muscle during embryonic development. Specific knockout of Zfp422 in skeletal muscle impaired embryonic muscle formation. Satellite cell-specific Zfp422 deletion severely inhibited muscle regeneration. Myoblast differentiation and myotube formation were suppressed in Zfp422-deleted C2C12 cells, isolated primary myoblasts, and satellite cells. Chromatin Immunoprecipitation Sequencing (ChIP-Seq) revealed that Zfp422 regulated ephrin type-A receptor 7 (EphA7) expression by binding an upstream 169-bp DNA sequence, which was proved to be an enhancer of EphA7. Knocking EphA7 down in C2C12 cells or deleting Zfp422 in myoblasts will inhibit cell apoptosis which is required for myoblast differentiation. These results indicate that Zfp422 is essential for skeletal muscle differentiation and fusion, through regulating EphA7 expression to maintain proper apoptosis.

BMC Genet ; 20(1): 72, 2019 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-31477002


BACKGROUND: Myogenic Differentiation 1 (MyoD) is a crucial master switch in regulating muscle-specific gene transcription. Forced expression of myoD is equipped to induce several cell lineages into myoblast, which then differentiate and fuse into myotube. Pig is one of the most significant livestock supplying meat, and has been classified into lean, fat and miniature pig breeds. However, the mechanisms underlying muscle mass variation among different pig breeds have remained unclear. Considering the important effect of MyoD on muscle development, it remains to be investigated whether the difference in muscle mass is caused by its single nucleotide polymorphisms (SNPs) which are the major differences among pig breeds at DNA level. RESULTS: In this study, we identified the locations of porcine myoD regulatory regions including proximal regulatory region (PRR), distal regulatory region (DRR), and core enhancer (CE) region. There are 8 SNPs in the regulatory regions and 6 SNPs in gene body region, which were identified from lean, fat and miniature pig populations. However, these SNPs have no effects on its temporal expression and transcriptional activity which might lead to the distinction in postnatal muscle mass. In addition, overexpression of myoD clones across from amphibious to mammals including xenopus tropicalis, chicken, mouse and pig whose gene identities vary from 68 to 84%, could promote myogenesis in NIH3T3 fibroblasts cells. CONCLUSIONS: These results proved that myoD nucleotide variations from different pig populations have no effect on muscle mass, suggesting that the function of myoD is highly conserved not only among different pig breeds, but also across different species. Thus, it would be futile to discover SNPs affecting muscle mass in pig populations with normal muscle development.

J Anim Sci ; 97(5): 1967-1978, 2019 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-31222274


Pig is one of the major dietary protein sources for human consumption, from which muscle is the largest protein origin. However, molecular mechanisms concerning early porcine embryonic muscle development distinctions between pig breeds are still unclear. In this study, an integrated analysis of transcriptome and miRNAome was conducted using longissimus dorsi muscle of 4 early embryonic stages around the primary myofiber formation time (18-, 21-, 28-, and 35-d post coitus) from 2 pig breeds (Landrace [LR] and Wuzhishan [WZS]) differing in meat mass. The global miRNA/mRNA expression profile showed that WZS prepared for myogenic developmental processes earlier than LR. After identifying and analyzing the interaction network of top 100 up-/down-regulated miRNA and their target genes, we were able to find 3 gene clusters: chromatin modification-related (Chd2, H3f3a, Chd6, and Mll1), myogenesis-related (Pax3, Pbx1, Mef2a, and Znf423), and myosin component-related (Mylk, Myo5a, Mylk4, Myh9, and Mylk2) gene clusters. These genes may involve in miRNA-gene myogenic regulatory network that plays vital role in regulating distinct early porcine embryonic myogenic processes between LR and WZS. In summary, our study reveals an epigenetic-mediated myogenic regulatory axial that will help us to decipher molecular mechanisms concerning early porcine embryonic muscle development distinctions between pig breeds.

Epigênese Genética , Regulação da Expressão Gênica no Desenvolvimento/genética , MicroRNAs/genética , RNA Mensageiro/genética , Suínos/genética , Transcriptoma , Animais , Desenvolvimento Embrionário/genética , Feminino , Perfilação da Expressão Gênica/veterinária , Redes Reguladoras de Genes , Masculino , Desenvolvimento Muscular/genética , Especificidade da Espécie , Suínos/embriologia , Suínos/crescimento & desenvolvimento
FASEB J ; 33(8): 9638-9655, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31145867


Here, we performed whole-genome bisulfite sequencing of longissimus dorsi muscle from Landrace and Wuzhishan (WZS) miniature pigs during 18, 21, and 28 d postcoitum. It was uncovered that in regulatory regions only around transcription start sites (TSSs), gene expression and methylation showed negative correlation, whereas in gene bodies, positive correlation occurred. Furthermore, earlier myogenic gene demethylation around TSSs and earlier hypermethylation of myogenic genes in gene bodies were considered to trigger their earlier expression in miniature pigs. Furthermore, by analyzing the methylation pattern of the myogenic differentiation 1(MyoD) promoter and distal enhancer, we found that earlier demethylation of the MyoD distal enhancer in WZSs contributes to its earlier expression. Moreover, DNA demethylase Tet1 was found to be involved in the demethylation of the myogenin promoter and promoted immortalized mouse myoblast cell line (C2C12) and porcine embryonic myogenic cell differentiation. This study reveals that earlier demethylation of myogenic genes contributes to precocious terminal differentiation of myoblasts in miniature pigs.-Zhang, X., Nie, Y., Cai, S., Ding, S., Fu, B., Wei, H., Chen, L., Liu, X., Liu, M., Yuan, R., Qiu, B., He, Z., Cong, P., Chen, Y., Mo, D. Earlier demethylation of myogenic genes contributes to embryonic precocious terminal differentiation of myoblasts in miniature pigs.

Respir Med ; 134: 110-116, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29413496


BACKGROUND AND OBJECTIVE: Bronchiectasis has been associated with increased risks of cardiovascular disease, in which early-stage endothelial dysfunction might have played pivotal roles. We aimed to investigate endothelial function in bronchiectasis patients, by measuring flow-mediated dilatation (FMD) and carotid intima-media thickness (CIMT) as compared with control subjects, and to elucidate the impact of different risk factors on subclinical atherosclerosis. METHODS: The study included 80 bronchiectasis patients and 80 age- and sex-matched healthy subjects. Vascular endothelial function was evaluated with FMD in the brachial artery in response to reactive hyperemia, and CIMT was measured with high-resolution ultrasonography. Disease severity was evaluated with Bronchiectasis Severity Index and FACED scores. Demographic, disease duration, radiology, spirometry, sputum bacteriology and systemic inflammatory indices were also assessed. RESULTS: FMD was significantly lower in bronchiectasis patients than in control subjects (8.92 ± 2.70% vs. 11.17 ± 3.44%, P < 0.001). FMD significantly correlated with Bronchiectasis Severity Index (rho = -0.60, P < 0.001) and FACED score (rho = -0.39, P < 0.001). In multivariate regression analysis, age, body-mass index, Pseudomonas aeruginosa colonization and high-resolution computed tomography scores were independent factors influencing on the FMD in bronchiectasis patients, even after adjustment for other clinical variables. No significant difference in CIMT was detected between bronchiectasis patients and healthy subjects (P > 0.05). CONCLUSIONS: Compared with healthy subjects, bronchiectasis patients have greater risks of endothelial dysfunction which is independent of previously well-studied risk factors, calling for the vigilance to screen early for vascular changes to minimize the future risks of cardiovascular events.

Aterosclerose/etiologia , Bronquiectasia/complicações , Adulto , Idoso , Aterosclerose/fisiopatologia , Artéria Braquial/fisiopatologia , Bronquiectasia/fisiopatologia , Espessura Intima-Media Carotídea , Estudos de Casos e Controles , Endotélio Vascular/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Índice de Gravidade de Doença , Vasodilatação/fisiologia