FOXO forkhead transcription factors play an important role in controlling lymphocyte activation and proliferation. To evaluate the possibility that FOXO transcriptional expression is dysregulated in systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) patients, we determined the quantities of FOXO1, FOXO3a, and FOXO4 transcripts in peripheral blood mononuclear cells (PBMCs) from normal controls as well as from SLE and RA patients. Results showed that FOXO1 and FOXO3a are dominant FOXO factors at the transcript level in PBMCs. Statistical analysis showed that the FOXO1 transcript levels in RA patients and in SLE patients with active disease activity were significantly lower than those in normal controls, and the FOXO1 transcript levels were inversely correlated with lupus disease activity. In contrast, the differences in FOXO3a and FOXO4 transcript levels between normal controls and patients were not significant. These data suggest that the transcriptional dysregulation in FOXO1 is possibly linked to the pathogenesis of SLE and RA.

Vascular inflammatory process has been suggested to play a key role in the initiation and progression of atherosclerosis, a major complication of diabetes mellitus. Recent studies have shown that brazilin exhibits antihepatotoxic, antiplatelet, cancer preventive, or anti-inflammatory properties. Thus, we investigated whether brazilin suppresses vascular inflammatory process induced by high glucose (HG) in cultured human umbilical vein endothelial cells (HUVEC). HG induced nitrite production, lipid peroxidation, and intracellular reactive oxygen species formation in HUVEC cells, which was reversed by brazilin. Western blot analysis revealed that brazilin markedly inhibited HG-induced phosphorylation of endothelial nitric oxide synthase. Besides, we investigated the effects of brazilin on the MAPK signal transduction pathway because MAPK families are associated with vascular inflammation under stress. Brazilin blocked HG-induced phosphorylation of extracellular signal-regulated kinase and transcription factor NF-κB. Furthermore, brazilin concentration-dependently attenuated cell adhesion molecules (ICAM-1 and VCAM-1) expression induced by various concentrations of HG in HUVEC. Taken together, the present data suggested that brazilin could suppress high glucose-induced vascular inflammatory process, which may be closely related with the inhibition of oxidative stress, CAMs expression, and NF-κB activation in HUVEC. Our findings may highlight a new therapeutic intervention for the prevention of vascular diseases.