Amino Acid Metabolism in Leukocytes Showing In Vitro IgG Memory from SARS-CoV2-Infected Patients.

The immune response to infectious diseases is directly influenced by metabolic activities. COVID-19 is a disease that affects the entire body and can significantly impact cellular metabolism. Recent studies have focused their analysis on the potential connections between post-infection stages of SARS-CoV2 and different metabolic pathways. The spike S1 antigen was found to have in vitro IgG antibody memory for PBMCs when obtaining PBMC cultures 60-90 days post infection, and a significant increase in S-adenosyl homocysteine, sarcosine, and arginine was detected by mass spectrometric analysis. The involvement of these metabolites in physiological recovery from viral infections and immune activity is well documented, and they may provide a new and simple method to better comprehend the impact of SARS-CoV2 on leukocytes. Moreover, there was a significant change in the metabolism of the tryptophan and urea cycle pathways in leukocytes with IgG memory. With these data, together with results from the literature, it seems that leukocyte metabolism is reprogrammed after viral pathogenesis by activating certain amino acid pathways, which may be related to protective immunity against SARS-CoV2.

Mechano-induced cell metabolism disrupts the oxidative stress homeostasis of SAOS-2 osteosarcoma cells.

There has been an increasing focus on cancer mechanobiology, determining the underlying-induced changes to unlock new avenues in the modulation of cell malignancy. Our study used LC-MS untargeted metabolomic approaches and real-time polymerase chain reaction (PCR) to characterize the molecular changes induced by a specific moderate uniaxial stretch regimen (i.e., 24 h-1 Hz, cyclic stretch 0,5% elongation) on SAOS-2 osteosarcoma cells. Differential metabolic pathway analysis revealed that the mechanical stimulation induces a downregulation of both glycolysis and the tricarboxylic acid (TCA) cycle. At the same time, the amino acid metabolism was found to be dysregulated, with the mechanical stimulation enhancing glutaminolysis and reducing the methionine cycle. Our findings showed that cell metabolism and oxidative defense are tightly intertwined in mechanically stimulated cells. On the one hand, the mechano-induced disruption of the energy cell metabolism was found correlated with an antioxidant glutathione (GSH) depletion and an accumulation of reactive oxygen species (ROS). On the other hand, we showed that a moderate stretch regimen could disrupt the cytoprotective gene transcription by altering the expression levels of manganese superoxide dismutase (SOD1), Sirtuin 1 (SIRT1), and NF-E2-related factor 2 (Nrf2) genes. Interestingly, the cyclic applied strain could induce a cytotoxic sensitization (to the doxorubicin-induced cell death), suggesting that mechanical signals are integral regulators of cell cytoprotection. Hence, focusing on the mechanosensitive system as a therapeutic approach could potentially result in more effective treatments for osteosarcoma in the future.