A human neuronal tissue culture model for Lesch-Nyhan disease.
Mutations in the gene encoding the purine salvage enzyme, hypoxanthine-guanine phosphoribosyltransferase (HPRT) cause Lesch-Nyhan disease, a neurodevelopmental disorder characterized by cognitive, neurological, and behavioral abnormalities. Despite detailed knowledge of the enzyme's function, the key pathophysiological changes that accompany loss of purine recycling are unclear. To facilitate delineating the consequences of HPRT deficiency, four independent HPRT-deficient sublines of the human dopaminergic neuroblastoma, SK-N-BE(2) M17, were isolated by targeted mutagenesis with triple helix-forming oligonucleotides. As a group, these HPRT-deficient cells showed several significant abnormalities: (i) impaired purine recycling with accumulation of hypoxanthine, guanine, and xanthine, (ii) reduced guanylate energy charge and GTP:GDP ratio, but normal adenylate energy charge and no changes in any adenine nucleotide ratios, (iii) increased levels of UTP and NADP+, (iv) reduced DOPA decarboxylase, but normal monoamines, and (v) reduction in cell soma size. These cells combine the analytical power of multiple lines and a human, neuronal origin to provide an important tool to investigate the pathophysiology of HPRT deficiency.
Shirley
Thomas L
TL
Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA, and Department of Biology, Necker-Enfants Malades Hospital, Paris, France.
Lewers
J Chris
JC
Egami
Kiyoshi
K
Majumdar
Alokes
A
Kelly
Mairead
M
Ceballos-Picot
Irene
I
Seidman
Michael M
MM
Jinnah
H A
HA
D000704:Analysis of Variance; D015306:Biogenic Monoamines / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D048429:Cell Size; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004296:Dopa Decarboxylase / Q000378:metabolism; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D007926:Lesch-Nyhan Syndrome / Q000201:enzymology* / Q000235:genetics*; D008954:Models, Biological; D009154:Mutation / Q000502:physiology; D009447:Neuroblastoma; D011687:Purines / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
D015306:Biogenic Monoamines; D011687:Purines; D007041:Hypoxanthine Phosphoribosyltransferase; D004296:Dopa Decarboxylase