Although melatonin has a variety of biological actions such as antitumor, antiangiogenic, and antioxidant activities, the osteogenic mechanism of melatonin still remains unclear. Thus, in the present study, the molecular mechanism of melatonin was elucidated in the differentiation of mouse osteoblastic MC3T3-E1 cells. Melatonin enhanced osteoblastic differentiation and mineralization compared to untreated controls in preosteoblastic MC3T3-E1 cells. Also, melatonin increased wound healing and dose-dependently activated osteogenesis markers such as runt-related transcription factor 2 (Runx2), osteocalcin (OCN), bone morphogenic protein (BMP)-2 and -4 in MC3T3-E1 cells. Of note, melatonin activated Wnt 5 α/β, β-catenin and the phosphorylation of c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) in a time-dependent manner while it attenuated phosphorylation of glycogen synthase kinase 3 beta (GSK-3β) in MC3T3-E1 cells. Consistently, confocal microscope observation revealed that BMP inhibitor Noggin blocked melatonin-induced nuclear localization of β-catenin. Furthermore, Western blotting showed that Noggin reversed activation of β-catenin and Wnt5 α/β and suppression of GSK-3β induced by melatonin in MC3T3-E1 cells, which was similarly induced by ERK inhibitor PD98059. Overall, these findings demonstrate that melatonin promotes osteoblastic differentiation and mineralization in MC3T3-E1 cells via the BMP/ERK/Wnt pathways.
Rigorous and systematic pre-clinical studies are necessary and essential to establish the efficacy and safety of Oriental herbs and formulas in order to transform traditional herbal practices into evidence-based medicine. Here we evaluated the anti-cancer activities of the ethanol extract of Ka-mi-kae-kyuk-tang (KMKKT), a formula of ten Oriental herbs, with a battery of in vitro and in vivo mechanism-based biomarkers involving angiogenesis, apoptosis and metastasis. The results show that KMKKT suppressed the vascular endothelial responses by inhibiting basic fibroblast growth factor (bFGF)-induced ERK1/2 phosphorylation, cell migration as well as tube formation in the human umbilical vein endothelial cell model, and decreased the hypoxia-induced HIF1alpha and vascular epithelial growth factor (VEGF) expression in the mouse Lewis lung carcinoma (LLC) cells in vitro, and inhibited the bFGF-induced angiogenesis in chick chorioallantoic membrane model, and in the Matrigel plugs in mice. Intraperitoneal delivery of KMKKT potently inhibited the growth of the subcutaneously inoculated LLC cells in syngenic mice. In addition, KMKKT inhibited the invasion ability of the mouse colon 26-L5 cancer cells in vitro and decreased their formation of liver metastasis when intraportally inoculated in syngenic mice. Furthermore, KMKKT suppressed the growth of the human PC-3 prostate cancer xenografts in athymic nude mice and averted the cancer-related body weight loss. The in vivo cancer growth suppression was associated with a decreased microvessel density and VEGF abundance as well as an increased PARP cleavage and the TUNEL-positive apoptosis. Together, our data support broad-spectra in vivo anti-cancer activities of KMKKT targeting angiogenesis, apoptosis and metastasis without any adverse effect on the body weight. This formula merits serious consideration for further evaluation for the chemoprevention and treatment of cancers of multiple organ sites.
Transplanting fetal kidney precursor cells showed the potential for the partial augmentation of kidney structure and function in the treatment of kidney failure.
Transient receptor potential vanilloid 1 (TRPV1), which has been identified as a molecular target for the activation of sensory neurons by various painful stimuli, was reported to regulate the signaling and activation of CD4+ T cells. However, the role of TRPV1 in CD4+ T cell in allergic rhinitis remains poorly understood. In this study, TRPV1 expression was localized in CD4+ T cells. Both knockout and chemical inhibition of TRPV1 suppressed Th2/Th17 cytokine production in CD4 T cells and Jurkat T cells, respectively, and can suppress T cell receptor signaling pathways including NF-κB, MAP kinase, and NFAT. In TRPV1 knockout allergic rhinitis (AR) mice, eosinophil infiltration, Th2/Th17 cytokines in the nasal mucosa, and total and ova-specific IgE levels in serum decreased, compared with wild-type AR mice. The TRPV1 antagonists, BCTC or theobromine, showed similar inhibitory immunologic effects on AR mice models. In addition, the number of TRPV1+/CD4+ inflammatory cells increased in the nasal mucosa of patients with AR, compared with that of control subjects. Thus, TRPV1 activation on CD4+ T cells is involved in T cell receptor signaling, and it could be a novel therapeutic target in AR.
We investigated the effects of an acidic environment on the G2/M-phase arrest, apoptosis, clonogenic death, and changes in cyclin B1-CDC2 kinase activity caused by a 4-Gy irradiation in RKO.C human colorectal cancer cells in vitro. The time to reach peak G2/M-phase arrest after irradiation was delayed in pH 6.6 medium compared to that in pH 7.5 medium. Furthermore, the radiation-induced G2/M-phase arrest decayed more slowly in pH 6.6 medium than in pH 7.5 medium. Finally, there was less radiation-induced apoptosis and clonogenic cell death in pH 6.6 medium than in pH 7.5 medium. It appeared that the prolongation of G2-phase arrest after irradiation in the acidic environment allowed for greater repair of radiation-induced DNA damage, thereby decreasing the radiation-induced cell death. The prolongation of G2-phase arrest after irradiation in the acidic pH environment appeared to be related at least in part to a prolongation of the phosphorylation of CDC2, which inhibited cyclin B1-CDC2 kinase activity.
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