Impact Of MicroRNA-22 On The Anticontractile Role Of PVAT

Impact Of MicroRNA-22 On The Anticontractile Role Of PVAT

• Autor
• Silva, CSB.
• Co-autores
• Lino, CA. , Couto, GK. , Rossoni, LV. , Diniz, GP.
• Resumo

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  Background: Blood vessels are surrounded by perivascular adipose tissue (PVAT), an adipose tissue depot that plays an important role in local regulation of vascular tonus due to its anticontractile effect. However, in obesity, PVAT is dysfunctional. A previous work of our laboratory demonstrated that microRNA-22 is involved in the inflammation of white adipose tissue in obese mice. Despite these findings, the role of microRNA-22 in PVAT and vascular reactivity, and whether this effect can be influenced by obesity are not known. Methods: To investigate the role of microRNA-22 in vascular reactivity, wild-type (n=18) and knockout (n=21) male mice for microRNA-22 were fed a control or a high-fat diet for 16 weeks (9249190719 - CEUA-ICB/USP). After the treatment, concentration-responses curves to noradrenaline were performed in thoracic aortic rings in the absence and presence of the PVAT. The data were analyzed by two-way ANOVA. Results: PVAT induced anticontractile effect in noradrenaline response in thoracic aorta of control WT mice (by 37.9%). Interestingly, loss of microRNA-22 abolished the anticontractile effect of PVAT in control diet-fed mice (represented by overlapping curves) and promoted a pro-contractile effect in the presence of higher concentrations of noradrenaline (10-6.5 - 10-5.5 M). PVAT of high-fat diet-fed animals showed reduced anticontractile effect (represented by a small shift to the right of the curve when compared to a greater shift of their respective control). Moreover, microRNA-22 deletion associated with obesity did not promote additive effects to those promoted by the absence of microRNA-22. Conclusion: MicroRNA-22 is important for the maintenance of the PVAT anticontractile effect. However, further studies are needed to elucidate how microRNA-22 deletion promotes the loss of the anticontractile effect of PVAT.

   

• Palavras-chave
• microRNA-22, obesity, PVAT
• Modalidade
• Comunicação oral
• Área Temática
• Tecido adiposo perivascular