ABSTRACT
Isomorphic mutation of the SBDS gene causes Shwachman-Diamond syndrome (SDS). SDS is a rare genetic bone marrow failure and cancer predisposition syndrome. SDS cells have ribosome biogenesis and their protein synthesis altered, which are two high-energy consuming cellular processes. The reported changes in reactive oxygen species production, endoplasmic reticulum stress response and reduced mitochondrial functionality suggest an energy production defect in SDS cells. In our work, we have demonstrated that SDS cells display a Complex IV activity impairment, which causes an oxidative phosphorylation metabolism defect, with a consequent decrease in ATP production. These data were confirmed by an increased glycolytic rate, which compensated for the energetic stress. Moreover, the signalling pathways involved in glycolysis activation also appeared more activated; i.e. we reported AMP-activated protein kinase hyper-phosphorylation. Notably, we also observed an increase in a mammalian target of rapamycin phosphorylation and high intracellular calcium concentration levels ([Ca(2+)]i), which probably represent new biochemical equilibrium modulation in SDS cells. Finally, the SDS cell response to leucine (Leu) was investigated, suggesting its possible use as a therapeutic adjuvant to be tested in clinical trials.
Subject(s)
Bone Marrow Cells/metabolism , Bone Marrow Diseases/metabolism , Calcium/metabolism , Cytochrome-c Oxidase Deficiency/metabolism , Exocrine Pancreatic Insufficiency/metabolism , Lipomatosis/metabolism , Mitochondria/metabolism , Proteins/genetics , Ribosomes/metabolism , AMP-Activated Protein Kinases/genetics , AMP-Activated Protein Kinases/metabolism , Adenosine Triphosphate/deficiency , Bone Marrow Cells/drug effects , Bone Marrow Cells/pathology , Bone Marrow Diseases/genetics , Bone Marrow Diseases/pathology , Cytochrome-c Oxidase Deficiency/genetics , Cytochrome-c Oxidase Deficiency/pathology , Electron Transport Complex IV/genetics , Electron Transport Complex IV/metabolism , Endoplasmic Reticulum Stress/drug effects , Endoplasmic Reticulum Stress/genetics , Exocrine Pancreatic Insufficiency/genetics , Exocrine Pancreatic Insufficiency/pathology , Gene Expression Regulation , Glycolysis/genetics , Humans , Leucine/pharmacology , Lipomatosis/genetics , Lipomatosis/pathology , Mitochondria/drug effects , Mitochondria/pathology , Mutation , Phosphorylation , Primary Cell Culture , Protein Biosynthesis , Proteins/metabolism , Reactive Oxygen Species/metabolism , Ribosomes/drug effects , Ribosomes/pathology , Shwachman-Diamond Syndrome , Signal Transduction , TOR Serine-Threonine Kinases/genetics , TOR Serine-Threonine Kinases/metabolismABSTRACT
Fanconi anemia (FA) is a genetic disorder characterised by chromosome instability, cytokine ipersensibility, bone marrow failure and abnormal haematopoiesis associated with acute myelogenous leukemia. Recent reports are contributing to characterize the peculiar FA metabolism. Central to these considerations appears that cells from complementation group A (FANCA) display an altered red-ox metabolism. Consequently the possibility to improve FA phenotypical conditions with antioxidants is considered. We have characterized from the structural and biochemical point of view the response of FANCA lymphocytes to N-acetyl-cysteine (NAC) and resveratrol (RV). Surprisingly both NAC and RV failed to revert all the characteristic of FA phenotype and moreover their effects are not super imposable. Our data suggest that we must be aware of the biological effects coming from antioxidant treatment.