Increased apoptotic response to 2-deoxy-D-ribose in ataxia-telangiectasia

Ataxia-telangiectasia (AT) is an autosomal recessive disease characterized by neurodegeneration and immunodeficiency. Hypersensitivity to radiation and chromosome instability are the biological markers of this disease. The gene responsible for AT (ATM)I has been identified on chromosome 11q22-23; it encodes a large polypeptide partially homologous to the phosphatidylinositol (PI) 3-kinase family. PI 3-kinase is a protein family playing an important role in the prevention of apoptosis. In order to investigate the apoptosis pathway, we tested peripheral blood cells from AT patients and controls exposed to 2-deoxy-D-ribose (dRib), a reducing sugar that induces apoptosis in human quiescent lymphocytes, probably through oxidative damage. Our results show that the response to dRib-induced apoptosis is significantly more elevated in AT cells than in control cells, suggesting that the apoptotic process plays a role in the pathogenesis of AT disease.