RESUMO
MicroRNAs (miRNAs) are non-coding small RNAs that regulate gene expression at the post-transcriptional level. Several miRNAs are exclusively expressed in skeletal muscle and participate in the regulation of muscle differentiation by interacting with myogenic factors. These miRNAs can be found at high levels in the serum of patients and animal models for Duchenne muscular dystrophy, which is expected to be useful as biomarkers for their clinical conditions. By miRNA microarray analysis, we identified miR-188 as a novel miRNA that is elevated in the serum of the muscular dystrophy dog model, CXMDJ. miR-188 was not muscle-specific miRNA, but its expression was up-regulated in skeletal muscles associated with muscle regeneration induced by cardiotoxin-injection in normal dogs and mice. Manipulation of miR-188 expression using antisense oligo and mimic oligo RNAs alters the mRNA expression of the myogenic regulatory factors, MRF4 and MEF2C. Our results suggest that miR-188 is a new player that participates in the gene regulation process of muscle differentiation and that it may serve as a serum biomarker reflecting skeletal muscle regeneration.
Assuntos
Biomarcadores/sangue , Regulação da Expressão Gênica , MicroRNAs/genética , Músculo Esquelético/metabolismo , Distrofia Muscular Animal/genética , Distrofia Muscular de Duchenne/genética , Animais , Diferenciação Celular , Células Cultivadas , Modelos Animais de Doenças , Cães , Camundongos , Músculo Esquelético/patologia , Distrofia Muscular Animal/sangue , Distrofia Muscular Animal/patologia , Distrofia Muscular de Duchenne/sangue , Distrofia Muscular de Duchenne/patologia , Mioblastos/citologia , Mioblastos/metabolismoRESUMO
Seventy-three Pseudomonas aeruginosa isolates were collected from dogs and cats in Japan to investigate antimicrobial susceptibility and resistance mechanisms to anti-pseudomonal agents. Resistance rates against orbifloxacin, enrofloxacin, ciprofloxacin, cefotaxime, aztreonam and gentamicin were 34.2, 31.5, 20.5, 17.8, 12.3 and 4.1%, respectively. The degree of resistance to cefotaxime, orbifloxacin, and enrofloxacin was greatly affected by efflux pump inhibitors, indicating overexpression of efflux pump contributes to these resistances. Notably, orbifloxacin and enrofloxacin resistance was observed even in isolates without mutations in the target sites. This is the first report on cephalosporin- and fluoroquinolone-resistant isolates of P. aeruginosa from Japanese companion animals.
