title: Human Bacterial Artificial Chromosome (BAC) Transgenesis Fully Rescues Noradrenergic Function in Dopamine β-Hydroxylase Knockout Mice.
abstract: Dopamine β-hydroxylase (DBH) converts dopamine (DA) to norepinephrine (NE) in noradrenergic/adrenergic cells. DBH deficiency prevents NE production and causes sympathetic failure, hypotension and ptosis in humans and mice; DBH knockout (Dbh -/-) mice reveal other NE deficiency phenotypes including embryonic lethality, delayed growth, and behavioral defects. Furthermore, a single nucleotide polymorphism (SNP) in the human DBH gene promoter (-970C>T; rs1611115) is associated with variation in serum DBH activity and with several neurological- and neuropsychiatric-related disorders, although its impact on DBH expression is controversial. Phenotypes associated with DBH deficiency are typically treated with L-3,4-dihydroxyphenylserine (DOPS), which can be converted to NE by aromatic acid decarboxylase (AADC) in the absence of DBH. In this study, we generated transgenic mice carrying a human bacterial artificial chromosome (BAC) encompassing the DBH coding locus as well as ~45 kb of upstream and ~107 kb of downstream sequence to address two issues. First, we characterized the neuroanatomical, neurochemical, physiological, and behavioral transgenic rescue of DBH deficiency by crossing the BAC onto a Dbh -/- background. Second, we compared human DBH mRNA abundance between transgenic lines carrying either a "C" or a "T" at position -970. The BAC transgene drove human DBH mRNA expression in a pattern indistinguishable from the endogenous gene, restored normal catecholamine levels to the peripheral organs and brain of Dbh -/- mice, and fully rescued embryonic lethality, delayed growth, ptosis, reduced exploratory activity, and seizure susceptibility. In some cases, transgenic rescue was superior to DOPS. However, allelic variation at the rs1611115 SNP had no impact on mRNA levels in any tissue. These results indicate that the human BAC contains all of the genetic information required for tissue-specific, functional expression of DBH and can rescue all measured Dbh deficiency phenotypes, but did not reveal an impact of the rs11115 variant on DBH expression in mice.
authors.affiliation: Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America.|Emory Autism Center, Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Cubells
authors.affiliation: Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors.forename: Jason P
authors.initials: JP
authors.lastname: Schroeder
authors.affiliation: Center for Pharmacogenomics, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America.
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Barrie
authors.affiliation: Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Manvich
authors.affiliation: Center for Pharmacogenomics, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Sadee
authors.affiliation: Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors.forename: Tiina
authors.initials: T
authors.lastname: Berg
authors.affiliation: Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America.|Graduate Program in Genetics and Molecular Biology, Emory University, Atlanta, Georgia, United States of America.
authors.forename: Kristina
authors.initials: K
authors.lastname: Mercer
authors.affiliation: Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors.forename: Taylor A
authors.initials: TA
authors.lastname: Stowe
authors.affiliation: Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors.forename: L Cameron
authors.initials: LC
authors.lastname: Liles
authors.affiliation: Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors.forename: Katherine E
authors.initials: KE
authors.lastname: Squires
authors.affiliation: Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors.forename: Andrew
authors.initials: A
authors.lastname: Mezher
authors.affiliation: Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors.forename: Patrick
authors.initials: P
authors.lastname: Curtin
authors.affiliation: Graduate Program in Genetics and Molecular Biology, Emory University, Atlanta, Georgia, United States of America.
authors.forename: Dannie L
authors.initials: DL
authors.lastname: Perdomo
authors.affiliation: MIRECC, VA Puget Sound Health Care System, Seattle, Washington, United States of America.|Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington, United States of America.
authors.forename: Patricia
authors.initials: P
authors.lastname: Szot
authors.affiliation: Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America.
authors.forename: David
authors.initials: D
authors.lastname: Weinshenker
mesh_terms: D000311:Adrenal Glands / Q000737:chemistry; D059331:Adrenergic Neurons / Q000378:metabolism; D000818:Animals; D001923:Brain Chemistry; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics / Q000502:physiology*; D004298:Dopamine / Q000032:analysis; D004299:Dopamine beta-Hydroxylase / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D018014:Gene Transfer Techniques; D006801:Humans; D017403:In Situ Hybridization; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009043:Motor Activity; D009206:Myocardium / Q000737:chemistry; D009638:Norepinephrine / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D004299:Dopamine beta-Hydroxylase; D004298:Dopamine; D009638:Norepinephrine