1 research outputs found
Human amnion epithelial stem cells as a therapy for liver disease
Placenta-derived stem cells have been proposed as potential new treatments for
acute and congenital liver diseases. Of all the different perinatal tissues, amnion
membrane and isolated amnion epithelial cells have been shown to be an outstanding
readily available source of multipotent stem cells. Human amnion epithelial
cells (hAEC) have unique properties, including low immunogenicity and immunomodulatory
properties, which may allow the first allogenic stem cell therapy
without immunosuppression. Animal studies have shown that hAEC differentiate
into hepatocyte-like cells and support missing liver functions commonly responsible
for inborn errors of metabolism. In the present thesis, we describe early preclinical
steps which will likely be necessary to translate hAEC therapy into clinical practice.
These steps include detailed and optimized methods for primary hAEC isolation
and preservation, methods to validate the final cell product and investigations
of the route of infusion for efficient engraftment in the target organ (liver). The
efficacy of hAEC transplants was assessed in preclinical models of liver disease.
In Project 1, we have detailed the hAEC isolation procedure with GMP reagents,
providing a homogenous amnion epithelial cell suspension. The preclinical validation
of hAEC-based therapy was continued in Project 2, where 14 different
batches of primary hAEC were characterized by immunocytological and biomolecular
techniques. The presented findings indicate this technology results in an
enriched suspension of epithelial cells with a minimal contamination with mesenchymal,
endothelial or hematopoietic cells. In Project 5, we validated the route
of infusion of hAEC to reach high level of engraftment in liver. We investigated
the bio-distribution of injected DiR-labelled hAEC administered via tail-vein or
intra-splenic, and monitored their localization using in vivo live imaging (IVIS)
techniques. Twenty-four hours post-splenic infusion, the majority of hAEC was
safely delivered and detected in the liver parenchyma. On the contrary, tail-vein
infusion resulted in a wide distribution pattern to multiple organs.
In Project 3, we have investigated the in vivo engraftment, long-term survival and
hepatic maturation of hAEC. We have injected hAEC into a metabolic liver disease
model of Phenylketonuria (PKU). This immune-competent PAH-deficient mouse
develops a pathological level of phenylalanine (PHE) in the blood, which is commonly
observed in PKU patients. We assessed hAEC engrafted into murine liver
parenchyma out to 100 days. Such long-term survival resulted in significant correction
of blood PHE levels in blood and a statistical complete correction or PHE
levels in the brain. The described xeno-transplantation was carried out without any
immunosuppressant regimen, and no signs of rejection were noticed.
Problems generating clinically relevant results by extrapolation of data from
mouse models was also addressed in Project 4, we successfully generated a liver-humanized
mouse model that faithfully reproduces the metabolic liver disease
observed in patients. We injected hepatocytes isolated from a CPS1 deficient
patient into immune-compromised mice (FRGN), where primary human hepatocytes
have been previously reported to engraft and fully repopulate the mouse
liver. The resultant chimeric CPS1-Deficient (CPS1-D) model exhibited high
blood ammonia levels, elevated disease-correlated amino acids (glutamine and
glutamate) and low CPS1 enzymatic activity.
In conclusion, during the past 4-year study we have successfully analyzed preclinical
data and validated the hypothesis that human amnion epithelial cells are
useful for the cellular therapy of liver disease, supporting their potential to become
a therapeutic tool to treat and support metabolic liver disease patients