HEPATIC DIFFERENTIATION OF FELINE LIVER ORGANOIDS

Abstract

Feline liver disease is a major clinical problem that in most cases difficult to treat. The pathogenesis of abundant liver disease is poorly understood. Since the liver is the most important organ for detoxifying the body, it is no wonder that it is largely known for its unequaled regenerative capacity. Regeneration can occur in two ways, the first is replication of mature hepatocytes which are normally quiescent. A second mechanism comes in to play when the liver is severe or chronically injured and normal hepatocyte proliferation is no longer sufficient to regenerate the liver, due to impairment and exhaustion. This is achieved by proliferation of local stem cells or hepatic progenitor cells. (HPCs). In recent years, a threedimensional (3D) culture system was developed for feline liver progenitor cells. These structures called “organoids” resemble whole organs that retain their continuous proliferation over a long period of time. In dog, mice and human differentiation of HPCs is already been accomplished. In this study cat organoids were subjected to a differentiation protocol based on a special medium where proliferation signals are blocked, leading to differentiation of adult stem cells toward functional hepatocytes. In total four organoid lines from individual donors were used. Gene expression and protein profiles with different markers (including HNF1b, HNF4a, PROX-1, TJP, TTR, TBX, LGR5, ALB, K19, K7, Cyp3a132, FAH, BMI and HEPPAR.) was executed. In the present study results showing a significant increase of maturation markers in the differentiation media, indicating that they have evolved to hepatocyte-like cells. In addition, they continue to express stem cell markers. Seemingly in this study, HPCs prompted for differentiation still preserve some of their stemness. However, overall gene expression clearly shows that differentiation media designed for this study induces a change toward hepatocyte differentiation in feline hepatic organoids.