Abnormal Purine and Pyrimidine Nucleotide Content in Primary Astroglia Cultures from Hypoxanthine-Guanine Phosphoribosyltransferase-Deficient Transgenic Mice
Autor: | Dori Pelled, Esther Zoref-Shani, Oded Sperling |
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Rok vydání: | 2008 |
Předmět: |
Purine
Hypoxanthine Phosphoribosyltransferase Mice Transgenic Biology Biochemistry Mice Cellular and Molecular Neuroscience chemistry.chemical_compound Adenosine Triphosphate Adenine nucleotide medicine Animals Nucleotide Purine metabolism Purine Nucleotides Cells Cultured Hypoxanthine chemistry.chemical_classification medicine.disease Adenosine Diphosphate chemistry Purines Hypoxanthine-guanine phosphoribosyltransferase Astrocytes Pyrimidine Nucleotides Guanosine Triphosphate Lesch–Nyhan syndrome |
Zdroj: | Journal of Neurochemistry. 72:1139-1145 |
ISSN: | 0022-3042 |
Popis: | Lesch-Nyhan syndrome is a pediatric metabolic-neurological syndrome caused by the X-linked deficiency of the purine salvage enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT). The cause of the metabolic consequences of HGPRT deficiency has been clarified, but the connection between the enzyme deficiency and the neurological manifestations is still unknown. In search for this connection, in the present study, we characterized purine nucleotide metabolism in primary astroglia cultures from HGPRT-deficient transgenic mice. The HGPRT-deficient astroglia exhibited the basic abnormalities in purine metabolism reported before in neurons and various other HGPRT-deficient cells. The following abnormalities were found : absence of detectable uptake of guanine and of hypoxanthine into intact cell nucleotides ; 27.8% increase in the availability of 5-phosphoribosyl-1-pyrophosphate ; 9.4-fold acceleration of the rate of de novo nucleotide synthesis ; manyfold increase in the excretion into the culture media of hypoxanthine (but normal excretion of xanthine) ; enhanced loss of label from prelabeled adenine nucleotides (loss of 71% in 24 h, in comparison with 52.7% in the normal cells), due to 4.2-fold greater excretion into the media of labeled hypoxanthine. In addition, the HGPRT-deficient astroglia were shown to contain lower cellular levels of ADP, ATP, and GTP, indicating that the accelerated de novo purine synthesis does not compensate adequately for the deficiency of salvage nucleotide synthesis, and higher level of UTP, probably due to enhanced de novo synthesis of pyrimidine nucleotides. Altered nucleotide content in the brain may have a role in the pathogenesis of the neurological deficit in Lesch-Nyhan syndrome. |
Databáze: | OpenAIRE |
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