Association of circulating microRNA-122 and microRNA-29a with stage of fibrosis and progression of chronic hepatitis in Labrador Retrievers.

Abstract

BACKGROUND: Chronic hepatitis (CH) in dogs is common and has the tendency to progress to liver cirrhosis (LC). Circulating microRNAs might have the potential as markers for disease progression. OBJECTIVES: To investigate whether concentration of specific microRNAs in serum correlate with the stage and grade of CH in Labrador Retrievers. ANIMALS: Twenty-two Labrador Retrievers with histological CH (n&#x2009;=&#x2009;8), LC (n&#x2009;=&#x2009;7), and normal liver (NL, n&#x2009;=&#x2009;7). METHODS: In this retrospective study, serum concentrations of miR-122, miR-29a, miR-133a, miR-181b, and miR-17-5p were measured by quantitative real-time PCR and evaluated using univariate linear regression in dogs. A multivariate model was fit including the grade of hepatitis and the stage of fibrosis. RESULTS: Of the 5 microRNAs, only circulating miR-122 and miR-29a were significantly associated with the grade of hepatitis and the stage of fibrosis. A positive correlation was identified between the grade of hepatitis with miR-122 (r&#x2009;=&#x2009;0.79, P&#x2009;<&#x2009;.001) and miR-29a (r&#x2009;=&#x2009;0.78, P&#x2009;<&#x2009;.001). Both miR-122 (r&#x2009;=&#x2009;0.81, P&#x2009;<&#x2009;.001) and miR-29a (r&#x2009;=&#x2009;0.67, P&#x2009;<&#x2009;.001) showed a significant positive correlation with the stage of fibrosis. MiR-122 concentrations were significantly higher in the CH (P&#x2009;<&#x2009;.01) and LC groups (P&#x2009;<&#x2009;.001) compared to the NL group. MiR-29a concentrations were significantly higher in the CH (P&#x2009;<&#x2009;.001) and LC (P&#x2009;<&#x2009;.001) groups compared to the NL group. CONCLUSIONS AND CLINICAL IMPORTANCE: Circulating miR-122 and miR-29a concentrations might be useful for monitoring the response to treatment and progression of canine CH.