Warfarin is one of the most frequently prescribed oral anticoagulant. Many researches have shown that the genotypes have been strongly associated with warfarin maintenance doses. Especially, it has been accepted in academia that cytochrome P450 2C9 (CYP2C9) and vitamin K epoxide reductase complex 1 subunit (VKORC1) could affect the warfarin maintenance doses. There are also many other genotypes that were reported to be related to warfarin doses, but the results have been in controversial so far. The studies found that the dose formula which contained the genetic factors and clinical information could accurately predict the maintenance dose of warfarin, however, its usefulness is suspected due to the inconsistent results of clinical trials. Large-sample and multi-center studies are necessary to verify the specific effects of gene and non-gene factors to warfarin dose; at the same time, testing constructed models or building new models help to improve the explained percentages of individual differences.
Objective To explore the mechanism by which ω-3 polyunsaturated fatty acids (hereinafter referred to as “ω-3”) exert antioxidant stress protection and promote osteogenic differentiation in MC3T3-E1 cells, and to reveal the relationship between ω-3 and the key antioxidant stress pathway involving nuclear factor E2-related factor 2 (Nrf2) and NAD (P) H: quinone oxidoreductase 1 (NQO1) in MC3T3-E1 cells. Methods The optimal concentration of H2O2 (used to establish the oxidative stress model of MC3T3-E1 cells in vitro) and the optimal high and low concentrations of ω-3 were screened by cell counting kit 8. MC3T3-E1 cells were divided into blank control group, oxidative stress group (H2O2), low dose ω-3 group (H2O2+low dose ω-3), and high dose ω-3 group (H2O2+high dose ω-3). After osteoblastic differentiation for 7 or 14 days, the intracellular ROS level was measured by fluorescence staining and flow cytometry, and the mitochondrial morphological changes were observed by biological transmission electron microscope; the expression levels of Nrf2, NQO1, heme oxygenase 1 (HO-1), Mitofusin 1 (Mfn1), and Mfn2 were detected by Western blot to evaluate the cells’ antioxidant stress capacity; the expression levels of Runt-related transcription factor 2 (Runx2) and osteocalcin (OCN) were detected by immunofluorescence staining and Western blot; osteogenic potential of MC3T3-E1 cells was evaluated by alkaline phosphatase (ALP) staining and alizarin red staining. Results Compared with the oxidative stress group, the content of ROS in the low and high dose ω-3 groups significantly decreased, and the protein expressions of Nrf2, NQO1, and HO-1 significantly increased (P<0.05). At the same time, the mitochondrial morphology of MC3T3-E1 cells was improved, and the expressions of mitochondrial morphology-related proteins Mfn1 and Mfn2 significantly increased (P<0.05). ALP staining and alizarin red staining showed that the low-dose and high-dose ω-3 groups showed stronger osteogenic ability, and the expression of osteogenesis-related proteins RUNX2 and OCN significantly increased (P<0.05). And the above results showed a dose dependence in the two ω-3 treatment groups (P<0.05). Conclusion ω-3 can enhance the antioxidant capacity of MC3T3-E1 cells under oxidative stress conditions and upregulate their osteogenic activity, possibly through the Nrf2/NQO1 signaling pathway.