ABSTRACT
miR-21 expression stimulates osteoclast cells in the context of osteoclastogenesis. A previous report showed that NFκB-miR-21 pathway could serve as an innovative alternative to devise therapeutics for healing diabetic ulcers. Furthermore, our study demonstrated that a highly water-soluble curcuminoids-rich extract (CRE-Ter) inhibits osteoclastogenesis through NFκB pathway. The interplay between miR-21 and CRE-Ter in osteoclastogenesis has not yet been investigated. In this study, we examined the relation of CRE-Ter and miR-21 gene expression in receptor of the nuclear factor κB (NFκB) ligand (RANKL) - induced murine monocyte/macrophage RAW 264.7 cells, osteoclast cells, in osteoclastogenesis. Effect of CRE-Ter on generation of intracellular reactive oxygen species (ROS) was estimated by dichlorofluorescein diacetate (DCFH-DA). The results reveal that CRE-Ter reduced expression levels of miR-21 gene in osteoclasts. The inhibitory effects of CRE-Ter on in vitro osteoclastogenesis were evaluated by reduction in tartrate-resistant acid phosphatase (TRAP) content, and by reduction in expression levels of an osteoclast-specific gene, cathepsin K. Treatment of the osteoclast cells with CRE-Ter suppressed RANKL-induced NFκB activation including phospho-NFκB-p65, and phospho IκBα proteins. Western blot analysis revealed that NFκB inhibitor up-regulated CRE-Ter-promoted expression of phospho-NFκB-p65. In addition, CRE-Ter dose-dependently inhibited phospho-Akt expression. CRE-Ter also dose-dependently reduced DNA binding activity of NFκB and Akt as revealed by EMSA. ChIP assay revealed binding of NFκB-p65 to miR-21 promoters. In conclusion, our results demonstrate that CRE-Ter downregulates miR-21 gene expression in osteoclasts via a de novo mechanism, NFκB- Akt-miR-21 pathway.
ABSTRACT
We identified naturally induced antibodies from malaria patients in Thailand and clarified the effect of the antibodies on gametocyte development. Fifty-nine percent of the Plasmodium falciparum-infected blood samples (17 of 29) fed to female Anopheles mosquitoes showed no oocyst infection. Seventeen percent of the samples (5 of 29) distorted the morphology and hampered the maturity of the gametocytes. A possible mechanism for the gametocyte inhibitory activity was shown by the binding of the plasma antibodies to live, immature, intraerythrocytic gametocytes during the incubation period. One hundred fifty-seven proteins specific to different gametocyte stages were explored to find the targets of the antisera that bound to the live gametocytes. However, no additional gametocyte transmission-blocking vaccine candidate was detected. Therefore, the development of alternative transmission-blocking vaccines in high-transmission areas should focus on the identification of more gametocyte antigens-inducing inhibitory antibodies that reduce gametocytemia.
