Hepatocyte B-CLEAR® Bilary Efflux Analysis

ADME/Tox Liver Drug Transporter Models

To aid in the investigation of specific drug transporters within the liver barrier, Sigma has generated transporter knockout (KO) cell lines using CompoZR Zinc Finger Nuclease (ZFN) technology in HepaRG cells. The transporters targeted include: MDR1 (P-gp), BSEP, MRP3, and OATP1B3.The HepaRG cells are ideal in that they express multiple transporters, are human derived and exhibit functionality of primary liver cells.

What is B-CLEAR?

The B-CLEAR technology refers to a patented methodology that, when applied to properly functioning hepatocytes in culture, opens the bile pockets (analogous to bile canaliculi in vivo), allowing the measurement of material that has been transported from inside the cell. Measurement of biliary efflux allows us to exclusively evaluate biliary clearance and biliary transporter interactions, as well as perform cellular mass balance measurements.

Data from the B-CLEAR model has been used in a variety of ways including in the prediction of clinically relevant drug interactions and in regulatory submissions to the FDA in support of mechanisms of transporter interactions and hepatotoxicity.

 

What is an integrated hepatic model and why is it important?

An integrated in vitro model maintains physiologic cellular components and processes at in vivo-relevant amounts. In the sandwich-cultured hepatocyte model, relevant drug transporter proteins (uptake and efflux), as well as drug metabolizing enzymes (Phase I and II), are expressed, maintained, and functioning together in the same system. The figure below graphically represents this concept.

To obtain a true in vivo understanding of hepatic disposition and drug interactions, all three major clearance pathways (uptake, metabolism, and efflux) must be present, ideally, within the same model system. A system that integrates these three pathways together can assess cellular compensation effects, which mirrors the in vivo situation. In addition, the presence of functional clearance pathways together means that studies to assess induction, hepatotoxicity, cholestasis, clearance, or drug interactions automatically generate physiologic concentrations and metabolites, thereby removing the need to artificially estimate or guess appropriate intracellular concentrations or conditions.

 

Application Highlight

HepaRG BSEP KO

HepaRG MDR1 KO

HepaRG MRP3 KO

HepaRG OATP1B3 KO

The HepaRG  knockout cell lines allows detailed investigations of BSEP-associated Drug-Induced Liver Injury (DILI) including; bile acid synthesis, transport, and accumulation, drug-drug interactions, transporter substrate assessment, CYP induction/inhibition, and metabolism mediated DILI.

Product Formats

24, 48 and 96 well Assay Ready Plates

Vials