Human primary and iPSC-derived hepatocyte cell therapies to treat liver disease
OA Version
Citation
Abstract
The liver is known for its fascinating ability to regenerate. However, in cases of both chronic and acute liver injury, innate liver regenerative mechanisms may become exhausted leading to end stage liver disease (ESLD), which can only be treated with liver transplantation. This study investigates two approaches aimed at alleviating liver damage: one involves stimulating the intrinsic, naturally occurring liver repair mechanisms, while the other explores the potential of hepatocyte cell therapy. Induction of intrinsic liver regeneration is an unmet need that can be achieved by temporally activating key hepatocyte regenerative pathways. Here, we establish an efficient, safe, non-integrative method to transiently express hepatocyte growth factor (HGF) and epidermal growth factor (EGF) in hepatocytes via nucleoside-modified mRNA encapsulated in lipid nanoparticles (mRNA-LNP) in mice. We confirm specific hepatotropism of intravenous injected mRNA-LNP, with protein expression lasting about three days. In the liver, virtually all hepatocytes are transfected along with a subpopulation of endothelial and Kupffer cells. In homeostasis, HGF+EGF mRNA-LNP efficiently induce hepatocyte proliferation. In a chronic liver injury mouse model recapitulating nonalcoholic fatty liver disease (NAFLD), injections of HGF+EGF mRNA-LNP sharply reverse steatosis and accelerate restoration of liver function. Likewise, HGF+EGF mRNA-LNP accelerate liver regeneration after acetaminophen induced acute liver injury with rapid return to baseline alanine aminotransferase (ALT) levels. This work introduces mRNA-LNP as a potentially translatable, safe, and therapeutic intervention to harness liver regeneration via controlled expression of endogenous hepatocyte mitogens in vivo. Primary human hepatocyte (PHH) transplantation is a promising alternative to liver transplantation, whereby liver function could be restored by partial repopulation of the diseased organ with healthy cells. However, currently clinical PHH engraftment efficiency is low, and benefits are not maintained long-term. Here we refine two mouse models of human chronic and acute liver diseases to recapitulate compromised hepatocyte proliferation observed in nearly all human liver diseases by overexpression of p21 in hepatocytes. In these clinically relevant contexts, we demonstrate that transient, yet robust expression of HGF and EGF in the liver via mRNA-LNP drastically improves PHH engraftment, reduces disease burden, and improves overall liver function. This novel strategy may overcome the critical barriers to clinical translation of cell therapies with primary or stem cell-derived hepatocytes for the treatment of liver diseases. To overcome the scarcity of donor livers for transplantation and primary cell therapy, hepatocytes generated from human induced pluripotent stem cells (hiPSC) could provide an unlimited supply of cells to treat liver diseases. However, generating hiPSC-derived hepatocyte-like cells (HLC) that can repopulate diseased livers remains a challenge. We demonstrate that continued HGF+EGF mRNA-LNP injections improves longer-term survival of transplanted HLCs for up to 5 weeks in a chronic liver injury mouse model. Given the known immaturity and poor survival of HLCs in vivo in comparison to primary cells, we propose that engineering HLCs to express key regenerative and maturation factors represents a potential strategy to overcome the obstacles of HLC therapies. This approach includes HLCs engineered to express maturation factors and activate mitogen pathways in combination with the use of clinically safe nucleoside-modified mRNA-LNP technology, with the goal to develop successful HLC based treatment for liver disease.
Description
2024
License
Attribution 4.0 International