Orthotopic
liver transplant (OLT) significantly improves patient outcomes in
maple syrup urine disease (MSUD; OMIM: 248600), yet organ shortages point to the need for
alternative therapies. Hepatocyte
transplantation has shown both clinical and preclinical efficacy as an intervention for metabolic
liver diseases, yet the availability of suitable livers for hepatocyte isolation is also limited. Conversely, human amnion epithelial cells (hAEC) may have utility as a hepatocyte substitute, and they share many of the characteristics of pluripotent embryonic stem cells while lacking their safety and ethical concerns. We reported that like hepatocytes,
transplantation of hAEC significantly improved survival and lifespan, normalized
body weight, and significantly improved
branched-chain amino acid (BCAA) levels in sera and brain in a transgenic murine model of
intermediate maple syrup urine disease (imsud). In the current report, we detail the neural and peripheral metabolic improvements associated with hAEC transplant in imsud mice, including
amino acids associated with bioenergetics, the
urea cycle, as well as the
neurotransmitter systems for
serotonin,
dopamine, and
gamma-aminobutyric acid (
GABA). This stem cell
therapy results in significant global correction of the metabolic profile that characterizes the disease, both in the periphery and the central nervous system, the target organ for toxicity in iMSUD. The significant correction of the disease phenotype, coupled with the theoretical benefits of hAEC, particularly their lack of immunogenicity and tumorigenicity, suggests that human amnion epithelial cells deserve serious consideration for clinical application to treat metabolic
liver diseases.