Hepatic Gene Expression of Angiogenic and Regeneration Markers in Cats with Congenital Portosystemic Shunts (CPSS)

Congenital portosystemic shunts (CPSS) are vascular anomalies resulting in liver hypoplasia and hepatic insufficiency. Cats with CPSS typically show signs of hepatic encephalopathy associated with increased ammonia, inflammatory cytokines, and oxidative stress. Surgical attenuation of the CPSS results in improved liver function, resolution of clinical signs, and increased portal blood flow. Hepatic gene expression has not previously been investigated in cats with CPSS. Here, we compared the hepatic expression of genes involved in the urea cycle (CPS1, NAGS), angiogenesis (VEGFR2, NPPA, NPR1, NPPC, NPR2, HIF1a), liver regeneration (SERPINB1, HGF, TGFβ), and metabolism (FGF21) from a small series of cats (n = 18) with CPSS to that of control cats (n = 10). The expression of TGFβ, VEGFR2, HGF, FGF21, and CPS1 was significantly elevated in liver biopsies from cats with CPSS. Cats that could only tolerate partial closure of their CPSS had increased hepatic expression of SERPINB1, HIF1a, and NPR2 compared with those that could tolerate complete ligation. Furthermore, there were no significant correlations between gene expression and pre-operative plasma ammonia concentrations in cats with CPSS. The changes in hepatic gene expression in cats with CPSS are in direct contrast to those seen in dogs with CPSS, suggesting alternative mechanisms may be involved in mediating hepatic changes in cats with CPSS.