RESUMEN
Effect of succinic acid on the processes of myogenesis was investigated in the study with the cells of C2C12 line. In the concentration range 10-1000 µM, succinic acid stimulated the process of myogenic differentiation, increasing the levels of myogenesis factors MyoD (at all stages of myogenesis) and myogenin (at the stage of terminal differentiation). Presence of the succinate receptors SUCNR1 was revealed in the C2C12 cells using Western blotting, level of which decreased during myogenesis. When succinic acid was added to the cells, the level of intracellular succinate did not change significantly and decreased during myogenic differentiation. Using a specific Gai protein inhibitor, pertussis toxin, it was found that stimulation of myogenesis in the C2C12 cells under the action of succinic acid is realized through SUCNR1-Gai interaction.
Asunto(s)
Diferenciación Celular , Desarrollo de Músculos , Ácido Succínico , Ácido Succínico/metabolismo , Desarrollo de Músculos/efectos de los fármacos , Animales , Ratones , Diferenciación Celular/efectos de los fármacos , Línea Celular , Receptores Acoplados a Proteínas G/metabolismo , Proteína MioD/metabolismo , Miogenina/metabolismoRESUMEN
P-Glycoprotein (P-gp) is one of the most clinically significant representatives of the ABC transporter superfamily due to its participation in the transport of biotic components and xenobiotics across the plasma membrane. It is known that various chemicals, environmental factors, and pathological processes can affect P-gp activity and expression. In this study, we investigated the role of P-gp in limiting the cell membrane permeability during oxidative stress. Human adenocarcinoma colon cells (Caco-2) overexpressing P-gp were cultured for 72 h in the medium containing hydrogen peroxide (0.1-50 µM). The transport of the P-gp substrate fexofenadine was evaluated in a special Transwell system. The amounts of P-gp and Nrf2 transcription factor were analyzed by the enzyme-linked immunosorbent assay. The concentration of SH-groups in proteins and the contents of lipid peroxidation products and protein carbonyl derivatives were determined spectrophotometrically. Hydrogen peroxide at a concentration of 0.1-5 µM did not significantly affect the studied parameters, while incubation with 10 µM H2O2 decreased in the level of SH groups in cell lysates and increased in the amount of Nrf2 in the cell lysates. Nrf2, in its turn, mediated an increase in the content and activity of the P-gp transporter, thus limiting the increasing permeability of the cell membrane. Hydrogen peroxide at a concentration of 50 µM promoted oxidative stress, which was manifested as a decrease in the content of SH-groups, increase in the concentration of lipid peroxidation products and protein carbonyl derivatives, and decrease in the P-gp level, which led to a significantly increased permeability of the plasma membrane. These results show that the transport and protective roles of P-gp, in particular, reduction of the cell membrane permeability, are affected by the intensity of oxidative stress and can be manifested only if the extent of membrane damage is insignificant.