A two-step lineage reprogramming strategy to generate functionally competent human hepatocytes from fibroblasts.

Area of Science:

• Cell Biology
• Regenerative Medicine
• Hepatology

Background:

• Lineage reprogramming aims to generate terminally differentiated cells but faces challenges like incomplete conversion and partial functionality.
• Existing methods often result in residual cell identity and limited functional capacity in reprogrammed cells.

Purpose of the Study:

• To develop a new reprogramming strategy that mimics natural regeneration for generating expandable hepatic progenitor cells and functional human hepatocytes.
• To overcome the limitations of incomplete conversion and partial functionality associated with traditional lineage reprogramming.

Main Methods:

• Fibroblasts were induced into human hepatic progenitor-like cells (hHPLCs).
• hHPLCs were expanded in vitro and assessed for in vivo engraftment.
• hHPLCs were further differentiated into mature human hepatocytes (hiHeps) in vitro.

Main Results:

• The new strategy successfully generated expandable hHPLCs that engrafted efficiently in vivo.
• Mature human hepatocytes (hiHeps) derived from hHPLCs exhibited molecular identity similar to primary human hepatocytes (PHHs).
• Generated hiHeps were functionally competent for drug metabolism estimation, toxicity prediction, and hepatitis B virus infection modeling.

Conclusions:

• Mimicking natural regeneration offers an advantageous route for lineage reprogramming, particularly by utilizing a progenitor cell stage.
• This strategy provides a promising method for generating large quantities of functional human hepatocytes and potentially other mature human cell types.
• The developed method addresses key challenges in cell reprogramming, paving the way for advancements in regenerative medicine and disease modeling.