Hepatocytes are commonly used in drug discovery and preclinical drug development to perform experiments requiring intact cellular systems. Intact hepatocytes contain the major hepatic drug-metabolizing enzymes required to study the four categories of xenobiotic biotransformation: Hydrolysis, Reduction, Oxidation and Conjugation. Because of these enzymes, hepatocytes provide a viable and cost-effective alternative to in vivo compound testings.
However one type of hepatocytes lot doesn’t fit all!
The choice of a particular lot shall be driven by the experimental applications, and not only the availability. To reduce availability concerns, we have selected 4 types of plateable hepatocytes:
- Cryoplateable from individual donors,
- Cryoplateable from pooled donors,
- Transporter certified
- Freshly isolated hepatocytes.
Below, I have summarized the main characteristics from each lot type. Please let me know if I can be of help to select the one for your application.
#1 – Cryoplateable Hepatocytes – Individual donors
Cryoplateable hepatocytes are the closest alternative to using fresh hepatocytes and are unique in their ability to attach to collagen substratum.
They respond to prototypical inducers even after being cryogenically frozen. Cryopreservation allows for long-term testing from the same donor while maintaining the ability to respond to prototypical inducers, maintain drug metabolizing enzymes and express transporter activity. Since these cryopreserved hepatocytes are not as time-sensitive as fresh hepatocytes, they are most commonly used for long-term metabolic stability, induction and toxicity, and transporter studies. These human plateable hepatocytes are characterised for specific CYP activity, general UGT and SULT activities and for induction application (both enzyme induction and mRNA induction).
Applications related to Individual donors’s Cryoplatable Heps
- Regulatory induction
- Long-term metabolic stability
- Transporter studies
Features and Benefits of Individual donor Cryoplatable Heps
- Large lot sizes & large number of lots,
- Market-leading characterization data available (including mRNA induction),
- High viability and cell yield.
#2 – Cryoplateable Hepatocytes – Pooled donors
CryostaX™ Plateable Pooled human hepatocytes are recommended for use in extended metabolism studies where long incubation times are required, as well as drug transport studies.
All of the CryostaX™ products are developed with a patent pending single-freeze process which minimizes cryoinjury and promotes high viability and cell yield.
CryostaX™ Plateable Pools contain five donors and meet XenoTech’s stringent culture criteria, maintaining good confluency and morphology for at least five days.
Applications related to Pooled donor Cryoplatable Heps
- Extended metabolism studies
- Transporter studies
- Early screening for induction
Features and benefits of Pooled donor Cryoplatable Heps
- Single-freeze process = minimized cryoinjury
- Unique pool of plateable hepatocytes on the market
#3 – Qualyst Transporter Certified™ Cryoplateable Hepatocytes
The Transporter Certified™ hepatocytes have passed a multi-point evaluation starting with plating/culturing characteristics and ending with a broad evaluation of hepatic functions including uptake and efflux transporter functions, metabolic function and baseline bile acid synthesis/production
Aside from just using high quality cells in your study, these cells can also be used in B-CLEAR® studies with a Qualyst Transporter Solutions Cell-Less B-CLEAR® Kit. Each lot of Transporter Certified™ hepatocytes contains the following information:
- Hepatic transporter activity for uptake OATPs (probe substrate Rosuvastatin, Pravastatin, Taurocholate), NTCP (Taurocholate), OAT1 & OAT3 (Methotrexate), OCT1 (Metformin). Efflux for BSEP (Taurocholate), P-gp (Digoxin), MATE 1 (Metformin), MRP2/BCRP (Rosuvastatin, Pravastatin, Methotrexate). The characterisation includes transported relative to fresh hepatocytes
- Bile acid profiles. % Glycine conjugates and % Taurine conjugates for the following: Transporter Certified™ lot,Fresh hepatocytes and In vivo
- Hepatic exposure (Kp Ratio) Provided. Kp ratios for Transporter Certified and fresh hepatocytes using the following substrates: Taurocholate, Digoxin, Metformin, Rosuvastatin, Pravastatin & Methotrexate
- Additional information provided: Viability, Cell yield, Protein content (mg/mL in 24-well), Conjugation capacity and biliary excretion & Drug-transporter interactions
Qualyst Transporter Certified™ Cryoplateable Hepatocyte applications
- Uptake and efflux transporter functions
- Metabolic function
- Baseline bile acid synthesis/production
- Hepatobiliary drug disposition
Features and Benefits of Qualyst Transporter Certified™ Cryoplateable Hepatocytes
- Highly characterized lots
- Bile canniculi formation
- Uptake & Efflux transporters expressed
# 4 – Fresh plated or Suspension Hepatocytes
Fresh human hepatocytes are available cultured on collagen coated plates and are an ideal alternative to in vivo testing. Cultured hepatocytes can be maintained over extended periods of time while maintaining hepatic specific functions for longer-term metabolism studies.
Because of the time-sensitive nature of fresh hepatocyte products, the availability of these unique heps is donor dependant. It is now possible to receive automatic notifications when fresh human hepatocyte lots are available. At tebu-bio, such a notication system is based on a subscription to an e-mail alert at firstname.lastname@example.org.
Fresh plated or suspension heps released are qualified with clear specifications (ex. ≥70% viability and ≥80% monolayer confluency (for plated cells)).
Applications of Fresh plated or Suspension Hepatocytes
- Regulatory inductions
- Long-term metabolic stability
- Transporter studies
Features and Benefits of Fresh plated or Suspension Hepatocytes
- Gold strandard for hepatocytes
- APHP located in Paris for efficient logistics in Europe
Various human hepatic-derived cell are now commercially available. These cell sources can now provide Drug discoverers with not only Hepatocytes but also with Total Liver Cell Population (TLC), Non-Parenchymal Cell Population, Stellates, Liver MyoFibroblasts, Kupffer Cells, Progenitors, Intra-hepatic biliary epithelial cells… under fresh or cryopreserved formats.
#5 – Hepatocytes and technical expertise!
Once you have selected the type of hepatocytes the most suited to your applications, you might be sure to have the most accurate experimental procedure to use these heps. You’ll find below some tips& tricks related to hepatocyte-based experimental procedures. These technical notes are based on the obesrvations I made during discussions with researchers and during the lab training I am doing in ADME labs in Europe.
How to find highly qualified Hepatocytes, lot availability and optimal technical support?
Simply feel free to contact me !
Hepatocyte cell sourcing:
For cryopreserved human and animal hepatocytes, tebu-bio selected XenoTech. As the industry leader in tissue-derived products for drug metabolism studies, XenoTech offers the widest variety of hepatocyte product.
For freshly isolated hepatocytes, tebu-bio is the distribution partner of Human HepCell, a spin-off from APHP (Assistance Publique – Hôpitaux de Paris). Human HepCell is a preclinical Contract Research Organization specialized in liver pathologies.