The study of cellular central carbon metabolism modulations induced by viruses is an emerging field. Human cytomegalovirus (HCMV), herpes simplex virus (HSV), Kaposi's sarcoma-associated herpesvirus (KSHV), and hepatitis C virus (HCV) have been shown recently to reprogram cell metabolism to support their replication. During HCV infection the global glucidolipidic metabolism of hepatocytes is highly impacted. It was suggested that HCV might modify glucose uptake and glycolysis to increase fatty acids synthesis, but underlying mechanisms have not been completely elucidated. We thus investigated how HCV may modulate glycolysis. We observed that in infected Huh7.5 cells and in subgenomic replicon-positive Huh9.13 cells, glucose consumption as well as lactate secretion was increased. Using protein complementation assays and coimmunoprecipitation, we identified a direct interaction between the HCV NS5A protein and cellular hexokinase 2 (HK2), the first rate-limiting enzyme of glycolysis. NS5A expression was sufficient to enhance glucose consumption and lactate secretion in Huh7.5 cells. Moreover, determination of HK activity in cell homogenates revealed that addition of exogenous NS5A protein, either the full-length protein or its D2 or D3, but not D1, domain, was sufficient to increase enzyme activity. Finally, determination of recombinant HK2 catalytic parameters (V max and K m ) in the presence of NS5A identified this viral protein as an activator of the enzyme. In summary, this study describes a direct interaction between HCV NS5A protein and cellular HK2 which is accompanied by an increase in HK2 activity that might contribute to an increased glycolysis rate during HCV infection. IMPORTANCESubstantial evidence indicates that viruses reprogram the central carbon metabolism of the cell to support their replication. Nevertheless, precise underlying mechanisms are poorly described. Metabolic pathways are structured as connected enzymatic cascades providing elemental biomolecular blocks necessary for cell life and viral replication. In this study, we observed an increase in glucose consumption and lactate secretion in HCV-infected cells, revealing higher glycolytic activity. We also identified an interaction between the HCV NS5A nonstructural protein and cellular hexokinase 2, the first rate-limiting enzyme of glycolysis. This interaction results in an enhancement of catalytic parameters of the enzyme, which might explain, at least in part, the aerobic glycolysis shift observed in HCV-infected cells. C hronic infection with hepatitis C virus (HCV) is associated with abnormalities in glucidolipidic metabolism that have been shown to play important roles in various aspects of the virus life cycle, such as genome replication, viral assembly, and secretion (1, 2). In vitro, HCV replication is efficiently inhibited by cholesterol and fatty acid biosynthetic pathway inhibitors (3), and release of viral particles from infected cells can be inhibited by modulation of the very-low-density lipoprotein (VLDL) assembly pr...

Adipose-derived stem/stromal cells (ASCs) reside in the stromal vascular fraction (SVF) of adipose tissue (AT) and can be easily isolated. However, extraction of the SVF from lipoaspirate is a critical step in generating ASC, and semiautomated devices have been developed to enhance the efficacy and reproducibility of the outcomes and to decrease manipulation and contamination. In this study, we compared the reference method used in our lab for SVF isolation from lipoaspirate, with three medical devices: GID SVF-1™, Puregraft™, and Stem.pras®. Cell yield and their viability were evaluated as well as their phenotype with flow cytometry. Further on, we determined their proliferative potential using population doublings (PD), PD time (PDT), and clonogenicity assay (CFU-F). Finally, we checked their genetic stability using RT-qPCR for TERT mRNA assay and karyotyping as well as their multilineage potential including adipogenic, chondrogenic, and osteogenic differentiation. Our results demonstrate that all the devices allow the production of SVF cells with consistent yield and viability, in less time than the reference method. Expanded cells from the four methods showed no significant differences in terms of phenotype, proliferation capabilities, differentiation abilities, and genetic stability.