Extrahepatic bile ducts outside the liver are a critical but poorly understood component of the human digestive system. The extrahepatic branches of the biliary tree feature glands that connect to the surface epithelium through narrow pits. Despite the continuous renewal of duct epithelia, the specific cells responsible for maintaining this tissue and their multiplicity remain unidentified.
A new study from Yale School of Medicine provides essential insights into the extrahepatic bile ducts. Using marker-free and targeted clonal fate mapping in mice, scientists offer insights that the extrahepatic bile duct is compartmentalized.
The study is significant as it explains how diseases affect these ducts.
Thanks to innovative methods, scientists have determined the complex structure of the extrahepatic bile duct. They used whole organ three-dimensional imaging and genetic labeling to track cells within different compartments of the extrahepatic bile duct. This helped us understand how these glands maintain homeostasis.
A significant discovery from the research is the identification of two distinct zones within the duct, each independently responsible for renewing specific parts of the duct. This compartmentalization resembles patterns observed in other organs, such as the body of the stomach, implying broader implications for our understanding of human biology.
Vikas Gupta, MD, PhD, assistant professor of medicine (digestive diseases), said, “We’ve known that the peribiliary glands become very active during diseases like cholangiocarcinoma. Studying how different compartments of epithelial cells change during biliary neoplasia can potentially give us better insight into cholangiocarcinoma.”
Despite advances, there are limitations to the study. Gupta cautioned, “Our study was conducted in a preclinical model, and while this provides valuable insights, it may not fully represent human biology. Accessing whole human extrahepatic bile duct tissue for research is a significant hurdle.”
In future research, the team aims to explore the cellular origins of cancer development further. Scientists aim to uncover new possibilities for early detection and treatment by investigating which cells within these compartments may initiate cancer.
Gupta said, “This research stands out for its potential to transform our understanding of a traditionally understudied area of human anatomy and disease. Our findings open the door to further exploration into how these ducts function and how diseases affecting them develop. This could lead to better diagnostic tools and treatments for conditions with limited therapeutic options.”
Journal Reference:
- Sarrena Singh, Qiuyu Lian, Tifanny Budiman et al. Heterogeneous murine peribiliary glands orchestrate compartmentalized epithelial renewal. Developmental Cell. DOI: 10.1016/j.devcel.2023.10.004