Distinguished Scientist Seminar Series featuring Irwin M. Arias, MD – “Hepatocyte Polarity; Neglected, Unique, Complex and Critical”

Distinguished Scientist Seminar Series

Irwin M. Arias, MD
Emeritus Professor of Medicine, Albert Einstein College of Medicine
Emeritus Professor of Physiology (Chair) and Medicine, Tufts University
Emeritus Senior Scientist NIH (currently)

Location: New Research Building Auditorium and via Zoom (https://georgetown.zoom.us/j/95197826709)

Title & Abstract:

“Hepatocyte Polarity; Neglected, Unique, Complex and Critical”

Cell polarity appeared when life began and is essential for formation of organs and organisms. An embryologic “blueprint” determines specific plasma membrane domains in all cells (sans erythrocytes) and is modified by cell-specific signals to form various polarity structues and pathways.  Herpatocyte polarity is almost totally neglected. It  is unique involving union of specific apical domains of two cells which form the bile canaliculus which is the smallest branch of the biliary tree ,and home to four ATP-dependent transporters which specifically secrete bile acids, sterols, phospholipid and organic cations. Inheritable defects in each pathway produce liver disease in man and animals.

For 25 years, we have collaborated with experts and used biochemical, biophysical, high resolution dynamic imaging and morphology, and, more recently, in vivo imaging to identify many of players in the polarity cascade. Experimentally induced molecular defects and inhibitors impaire polarity eventual resulting in  cell death.

The talk will consider the following: How do the transporters selectively target the canalicular apical domain? What regulates these pathways? What happens when individual pathway components are inhibited or deleted? Do these studies apply to acquire as well as inheritable liver disease?  What are the challenges?