Bone morphogenetic protein (BMP) 2 is a potent osteogenic factor. Although both Smad1/5 and mitogenactivated protein kinases (MAPKs) are activated by BMP2, the hierarchical relationship between them is unclear. In this study, we examined if BMP2-stimulated MAPK activation is regulated by Smad1/5 or vice versa. When C2C12 cells were treated with BMP2, the activation of extracellular signal-regulated kinase (ERK), p38 MAPK and c-Jun-N-terminal kinase was evident within 5 min. The knockdown of both Smad1 and Smad5 by small interfering RNA did not affect the activation of these MAPKs. In addition, neither the overexpression of Smad1 nor Smad5 induced ERK activation. When ERK activation was induced by constitutively active MEK1 expression, the protein level and activation of Smad1 increased. Furthermore, the inhibition of constitutively active BMP receptor type IB-induced ERK activation significantly suppressed Smad1 activation. These results indicate that Smad1/5 activation is not necessary for BMP2-induced MAPK activation and also that ERK positively regulates Smad1 activation.
Long-term ultraviolet (UV) exposure accelerates the phenomenon of skin photo-aging by activating collagenase and elastase. In this study, we aimed to investigate the effects of a combination of grapefruit and rosemary extracts (cG&Re) on UVB-irradiated damage in HaCaT cells and dorsal mouse skin. In HaCaT cells, cG&Re recovered UVB-reduced cell viability and inhibited protein expression of mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinases (p-Erk), c-Jun N-terminal kinases (p-JNK), and a class of MAPKs (p-P38). Also, cG&Re suppressed UVB-induced collagen and elastin degradation by decreasing matrix metalloproteinases (MMPs) and nuclear factor kappa light chain enhancer of activated B cells (NF-κB) expression, which is a transcription factor. Similar results were observed in dorsal mouse skin. Taken together, our data indicate that cG&Re prevent UVB-induced skin photo-aging due to collagen/elastin degradation via activation of MAPKs, MMPs, and the NF-κB signaling pathway in vitro and in vivo.
Aralia cordata (A. cordata), which belongs to Araliaceae, is a perennial herb widely distributed in East Asia. We evaluated the anti-inflammatory effect of stems (AC-S), roots (AC-R) and leaves (AC-L) extracted with 100% methanol of A. cordata and elucidated the potential signaling pathway in LPS-stimulated RAW264.7 cells. The AC-L showed a strong anti-inflammatory activity through inhibition of NO production. AC-L dose-dependently inhibited NO production by suppressing iNOS, COX-2 and IL-β expression in LPS-stimulated RAW264.7 cells. AC-L inhibited the degradation and phosphorylation of IκB-α, which donated to the inhibition of p65 nuclear accumulation and NF-κB activation. Furthermore, AC-L suppressed the phosphorylation of ERK1/2 and p38. These results suggested that AC-L may utilize anti-inflammatory activity by blocking NF-κB and MAPK signaling pathway and indicated that the AC-L can be used as a natural anti-inflammatory drugs.
Abeliophyllum distichum is a medicinal plant used in regional traditional medicine to relieve pain in inflammatory processes. In this study, anti-inflammatory effects of Abeliophyllum distichum flower (ADF) extract were examined. Furthermore, possible molecular mechanisms of the anti-inflammatory effects were dissected. The anti-inflammatory activity was investigated by inhibition of lipopolysaccharide (LPS) induced pro-inflammatory cytokine production in murine macrophage-like cell line Raw264.7 cells. The measurement of the induced pro-inflammatory cytokine levels were carried out by ELISA. The phosphorylation of ERK1/2, JNK, and MAPK, and the nuclear expression of nuclear factor NF-κ B p65 were investigated by Western blot analysis. The extract of ADF significantly decreased the production of pro-inflammatory cytokines. In addition, the extract suppressed the phosphorylation of ERK1/2, JNK, and p38 MAPK, and the nuclear translocation of NF-κB p65 in activated cells. Our findings provide evidence for the popular use of Abeliophylli distichum in inflammation around Goesan region and also suggest that the flower extract has potential therapeutic benefits against various inflammatory diseases.
Rubia cordifolia has been used to treat diseases for many years in China and India. Although the biological properties and major compounds of R. cordifolia have been extensively studied, the underlying mechanisms of its biological effects remain elusive. In terms of immunological effects, anti-inflammation effect of macrophage (Raw 264.7) simply has been reported. In this study, R. cordifolia was extracted in 70% ethanol and the extract did not affect to macrophage (Raw 264.7) pro-inflammation and T cell (Molt-4). However, in mast cell (RBL-2H3), it showed inhibition of degranulation. The inducing inhibitory effect on degranulation was related to concentration dependent variation in phosphorylation of ERK-1/2 and upregulating the JNK phosphorylation in RBL-2H3 cells. Based on these data, we concluded that R. cordifolia newly have anti-allergenic effects in RBL-2H3 and might be used as a therapeutic agent to treat or prevent allergic diseases such as asthma and atopic dermatitis.