Clinical Characteristics, Serum Biochemical Changes, and Expression Profile of Serum Cfa-miRNAs in Dogs Confirmed to Have Congenital Portosystemic Shunts Accompanied by Liver Pathologies

Computed tomography angiography (CTA) and biochemical parameters cannot specify liver pathologies in dogs with congenital portosystemic shunts (CPSS) that are easily determined by invasive histopathology. This study aims to assess the possibility of using circulating serum canine familiaris (cfa) microRNAs (miRNAs) as novel non-invasive serum-based fingerprints for liver injuries associated with various morphologies of extrahepatic and intrahepatic portosystemic shunts (EHPSS and IHPSS). Data were obtained from 12 healthy dogs and 84 dogs confirmed to have EHPSS (splenocaval, splenophrenic, splenoazygos, right gastrocaval (RGC), right gastrocaval with caudal loop (RGC–CL)) and IHPSS (right divisional and left divisional) using CTA. Hepatic pathologies were determined by histopathology. Serum expression of miRNAs was assessed by real-time polymerase chain reaction. Based on the nature of liver injuries in each shunt type, cfa-miR-122 was significantly upregulated in all CPSS groups. Meanwhile, serums cfa-miR-34a and 21 were not significantly expressed in splenophrenic or splenoazygos groups, but they were extensively upregulated in splenocaval, RGC, RGC–CL groups and less frequently in right or left divisional groups. Also, serum cfa-miR126 was significantly upregulated in both IHPSS groups but less significantly expressed in RGC, RGC–CL, and splenocaval groups. Overall, estimated cfa-miRNAs could serve as novel biomarkers to mirror the histopathological and molecular events within the liver in each shunt type.