title: Restoring Ureagenesis in Hepatocytes by CRISPR/Cas9-mediated Genomic Addition to Arginase-deficient Induced Pluripotent Stem Cells.
abstract: Urea cycle disorders are incurable enzymopathies that affect nitrogen metabolism and typically lead to hyperammonemia. Arginase deficiency results from a mutation in Arg1, the enzyme regulating the final step of ureagenesis and typically results in developmental disabilities, seizures, spastic diplegia, and sometimes death. Current medical treatments for urea cycle disorders are only marginally effective, and for proximal disorders, liver transplantation is effective but limited by graft availability. Advances in human induced pluripotent stem cell research has allowed for the genetic modification of stem cells for potential cellular replacement therapies. In this study, we demonstrate a universally-applicable CRISPR/Cas9-based strategy utilizing exon 1 of the hypoxanthine-guanine phosphoribosyltransferase locus to genetically modify and restore arginase activity, and thus ureagenesis, in genetically distinct patient-specific human induced pluripotent stem cells and hepatocyte-like derivatives. Successful strategies restoring gene function in patient-specific human induced pluripotent stem cells may advance applications of genetically modified cell therapy to treat urea cycle and other inborn errors of metabolism.
authors.affiliation: Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.|Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
authors.forename: Patrick C
authors.initials: PC
authors.lastname: Lee
authors.affiliation: Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.|Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Truong
authors.affiliation: Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.|Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
authors.forename: Agustin
authors.initials: A
authors.lastname: Vega-Crespo
authors.affiliation: Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
authors.forename: W Blake
authors.initials: WB
authors.lastname: Gilmore
authors.affiliation: Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.|Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
authors.forename: Kip
authors.initials: K
authors.lastname: Hermann
authors.affiliation: Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
authors.forename: Stephanie Ak
authors.initials: SA
authors.lastname: Angarita
authors.affiliation: Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.|Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
authors.forename: Jonathan K
authors.initials: JK
authors.lastname: Tang
authors.affiliation: Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.|Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Chang
authors.affiliation: Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
authors.forename: Austin E
authors.initials: AE
authors.lastname: Wininger
authors.affiliation: Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
authors.forename: Alex K
authors.initials: AK
authors.lastname: Lam
authors.affiliation: Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.|Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
authors.forename: Benjamen E
authors.initials: BE
authors.lastname: Schoenberg
authors.affiliation: Department of Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.|Intellectual and Developmental Disabilities Research Center at UCLA, Los Angeles, California, USA.|Semel Institute for Neuroscience, UCLA, Los Angeles, California, USA.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Cederbaum
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, UCLA, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
authors.forename: April D
authors.initials: AD
authors.lastname: Pyle
authors.affiliation: Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.|Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Byrne
authors.affiliation: Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.|Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.|Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.|Department of Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.|Intellectual and Developmental Disabilities Research Center at UCLA, Los Angeles, California, USA.|Semel Institute for Neuroscience, UCLA, Los Angeles, California, USA.|Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.|Department of Urology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
authors.forename: Gerald S
authors.initials: GS
authors.lastname: Lipshutz