@article {10421, title = {Hypomorphic FANCA mutations correlate with mild mitochondrial and clinical phenotype in Fanconi anemia.}, journal = {Haematologica}, volume = {103}, year = {2018}, month = {2018 Mar}, pages = {417-426}, abstract = {

Fanconi anemia is a rare disease characterized by congenital malformations, aplastic anemia, and predisposition to cancer. Despite the consolidated role of the Fanconi anemia proteins in DNA repair, their involvement in mitochondrial function is emerging. The purpose of this work was to assess whether the mitochondrial phenotype, independent of genomic integrity, could correlate with patient phenotype. We evaluated mitochondrial and clinical features of 11 affected individuals homozygous or compound heterozygous for p.His913Pro and p.Arg951Gln/Trp, the two residues of FANCA that are more frequently affected in our cohort of patients. Although p.His913Pro and p.Arg951Gln proteins are stably expressed in cytoplasm, they are unable to migrate in the nucleus, preventing cells from repairing DNA. In these cells, the electron transfer between respiring complex I-III is reduced and the ATP/AMP ratio is impaired with defective ATP production and AMP accumulation. These activities are intermediate between those observed in wild-type and FANCA-/- cells, suggesting that the variants at residues His913 and Arg951 are hypomorphic mutations. Consistent with these findings, the clinical phenotype of most of the patients carrying these mutations is mild. These data further support the recent finding that the Fanconi anemia proteins play a role in mitochondria, and open up possibilities for genotype/phenotype studies based on novel mitochondrial criteria.

}, issn = {1592-8721}, doi = {10.3324/haematol.2017.176131}, author = {Bottega, Roberta and Nicchia, Elena and Cappelli, Enrico and Ravera, Silvia and De Rocco, Daniela and Faleschini, Michela and Corsolini, Fabio and Pierri, Filomena and Calvillo, Michaela and Russo, Giovanna and Casazza, Gabriella and Ramenghi, Ugo and Farruggia, Piero and Dufour, Carlo and Savoia, Anna} } @article {10521, title = {Defects in mitochondrial energetic function compels Fanconi Anaemia cells to glycolytic metabolism.}, journal = {Biochim Biophys Acta Mol Basis Dis}, volume = {1863}, year = {2017}, month = {2017 06}, pages = {1214-1221}, abstract = {

Energetic metabolism plays an essential role in the differentiation of haematopoietic stem cells (HSC). In Fanconi Anaemia (FA), DNA damage is accumulated during HSC differentiation, an event that is likely associated with bone marrow failure (BMF). One of the sources of the DNA damage is altered mitochondrial metabolism and an associated increment of oxidative stress. Recently, altered mitochondrial morphology and a deficit in the energetic activity in FA cells have been reported. Considering that mitochondria are the principal site of aerobic ATP production, we investigated FA metabolism in order to understand what pathways are able to compensate for this energy deficiency. In this work, we report that the impairment in mitochondrial oxidative phosphorylation (OXPHOS) in FA cells is countered by an increase in glycolytic flux. By contrast, glutaminolysis appears lower with respect to controls. Therefore, it is possible to conclude that in FA cells glycolysis represents the main pathway for producing energy, balancing the NADH/NAD ratio by the conversion of pyruvate to lactate. Finally, we show that a forced switch from glycolytic to OXPHOS metabolism increases FA cell oxidative stress. This could be the cause of the impoverishment in bone marrow HSC during exit from the homeostatic quiescent state. This is the first work that systematically explores FA energy metabolism, highlighting its flaws, and discusses the possible relationships between these defects and BMF.

}, keywords = {Cell Line, Fanconi Anemia, Glycolysis, Humans, Mitochondria, Oxidative Phosphorylation, Oxidative Stress}, issn = {0925-4439}, doi = {10.1016/j.bbadis.2017.03.008}, author = {Cappelli, Enrico and Cuccarolo, Paola and Stroppiana, Giorgia and Miano, Maurizio and Bottega, Roberta and Cossu, Vanessa and Degan, Paolo and Ravera, Silvia} } @article {8350, title = {Evaluation of energy metabolism and calcium homeostasis in cells affected by Shwachman-Diamond syndrome.}, journal = {Sci Rep}, volume = {6}, year = {2016}, month = {2016}, pages = {25441}, 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.

}, issn = {2045-2322}, doi = {10.1038/srep25441}, author = {Ravera, Silvia and Dufour, Carlo and Cesaro, Simone and Bottega, Roberta and Faleschini, Michela and Cuccarolo, Paola and Corsolini, Fabio and Usai, Cesare and Columbaro, Marta and Cipolli, Marco and Savoia, Anna and Degan, Paolo and Cappelli, Enrico} }