Neuroprotective effect of LSS on Aβ_(1-42)-induced BV-2 microglial cells through the inhibition of neuroinflammation

OBJECTIVE To investigate the effect of neuroprotective effect of lychee seed saponins(LSS) in BV-2.METHODS Aβ_(1-42) induced BV-2 cells were incubated with LSS for 12 h,the content of the inflammatory factors such as IL~(-1)β,TNF-α,COX-2 and i NOS in the supernatant of BV-2 cell were measured by ELISA.The detection of the m RNA levels and the protein expression of the inflammatory factors including IL~(-1)β,TNF-α,COX-2 and i NOS using real-time PCR and Western blotting,respectively.RESULTS The level of IL~(-1)β,COX-2 and i NOS significantly increased with the treatment of Aβ_(1-42),and 0.117 mg·L~(-1)-0.469 mg·L~(-1) LSS can inhibit these increased level.CONCLUSION LSS conferred neuroprotection via inhibiting the inflammatory factors expression.     

The interplay between TGF-β/SMAD and BMP/SMAD signaling pathways in the epithelial mesenchymal transition of A549 cells induced by silica

The epithelial–mesenchymal transition (EMT) is a phenotype transdifferentiation of epithelial into mesenchymal cells and contributes to pulmonary fibrotic disease. SMAD-dependent pathway has been reported to play a key role in the multiple fibrotic diseases. We hypothesized that TGF-β/SMAD signaling could cross-interact with BMP/SMAD signaling pathways in silica-induced EMT in A549 cells. We investigated that the ability of silica-induced EMT in A549 cells, and this process was significantly inhibited by SB431542 through up-regulation of Vimentin, α-SMA and collagen type I expression and down-regulation of E-cadherin expression. Whereas BMP/SMAD inhibition using LDN193189 enhanced EMT. In addition, we also demonstrated that SB431542 could enhance BMP/SMAD signaling pathways in silica-induced EMT and vice versa. Therefore, our study provides evidence that the TGF-β/SMAD pathway was a crucial regulator in silica-induced EMT and that SB431542 could prevent the EMT. More importantly, we have identified that the interplay of TGF-β/SMAD and BMP/SMAD pathways in silica-induced EMT in A549 cells.     

MicroRNA-147b suppresses the proliferation and invasion of non-small-cell lung cancer cells through downregulation of Wnt/β-catenin signalling via targeting of RPS15A

Deregulation of microRNAs (miRNAs) leads to malignant growth and aggressive invasion during cancer occurrence and progression. miR-147b has emerged as one of the cancer-related miRNAs that are dysregulated in multiple cancers. Yet, the relevance of miR-147b in non-small-cell lung cancer (NSCLC) remains unclear. In the present study, we aimed to report the biological function and signalling pathways mediated by miR-147b in NSCLC. Our results demonstrate that miR-147b expression is significantly downregulated in NSCLC tissues and cell lines. Overexpression of miR-147b decreased the proliferative ability, colony-forming capability, and invasive potential of NSCLC cells. Notably, our study identified ribosomal protein S15A (RPS15A), an oncogene in NSCLC, as a target gene of miR-147b. Our results showed that miR-147b negatively modulates RPS15A expression in NSCLC cells. An inverse correlation between miR-147b and RPS15A was evidenced in NSCLC specimens. Moreover, miR-147b overexpression downregulated the activation of Wnt/β-catenin signalling via targeting of RPS15A. Overexpression of RPS15A partially reversed the miR-147b-mediated antitumour effect in NSCLC cells. Collectively, these findings reveal that miR-147b restricts the proliferation and invasion of NSCLC cells by inhibiting RPS15A-induced Wnt/β-catenin signalling and suggest that the miR-147b/RPS15A/Wnt/β-catenin axis is an important regulatory mechanism for malignant progression of NSCLC.     

Saponins from the roots of Platycodon grandiflorum suppress ultraviolet A-induced matrix metalloproteinase-1 expression via MAPKs and NF-κB/AP-1-dependent signaling in HaCaT cells

Saponins from the roots of Platycodon grandiflorum (CKS) have been shown to exhibit many pharmacological activities, including anti-cancer and anti-inflammatory activities and antioxidant effects. However, anti-skin photoaging effects of CKS have not yet been reported. In this study, we investigated the protective effects of CKS against UVA damage on immortalized human keratinocytes (HaCaT). We then explored the inhibitory effects of CKS on UVA-induced MMP-1 and investigated the molecular mechanism underlying those effects. CKS increased the cell viability and inhibited reactive oxygen species (ROS) production in HaCaT cells exposed to UVA irradiation. Pre-treatment of HaCaT cells with CKS inhibited UVA-induced production of MMP-1 and MMP-9. In addition, CKS decreased UVA-induced expression of the inflammatory cytokines IL-1β and IL-6. Western blot analysis further revealed that CKS markedly suppressed the enhancement of collagen degradation in UVA-exposed HaCaT cells. CKS also suppressed UVA-induced activation of NF-κB or c-Jun and c-Fos, and the phosphorylation of MAPKs, which are upstream modulators of NF-κB and AP-1.     

MicroRNA-520e targets AEG-1 to suppress the proliferation and invasion of colorectal cancer cells through Wnt/GSK-3β/β-catenin signalling

MicroRNA-520e (miR-520e) is increasingly being recognized as a cancer-related miRNA in multiple cancer types; however, little is known about its role in colorectal cancer. In this study, we determined the specific role of miR-520e in colorectal cancer. Expression of miR-520e was lower in colorectal cancer tissues compared to normal tissues. Overexpression of miR-520e significantly decreased the proliferation, colony formation and invasion of colorectal cancer cells, while inhibition of miR-520e exhibited the opposite effect. Moreover, miR-520e was found to target the 3′-untranslated region of astrocyte elevated gene-1 (AEG-1) and inhibit AEG-1 expression in colorectal cancer cells. An inverse correlation between miR-520e and AEG-1 expression was confirmed in colorectal cancer tissues. Notably, miR-520e suppressed the phosphorylation of glycogen synthase kinase-3β and decreased the expression of β-catenin, leading to inactivation of Wnt/β-catenin signalling in colorectal cells. A rescue assay confirmed that miR-520e regulates cell proliferation, invasion and Wnt/β-catenin signalling through targeting AEG-1. Taken together, these results indicate that miR-520e plays a critical role in regulating colorectal cancer cell proliferation and invasion by inhibiting Wnt/β-catenin signalling via AEG-1. Our study highlights the importance of the miR-520e/AEG-1/Wnt/β-catenin signalling axis in colorectal cancer, thus targeting miR-520e may represent an effective therapeutic strategy.     

Anti-inflammatory activity of bark of Dioscorea batatas DECNE through the inhibition of iNOS and COX-2 expressions in RAW264.7 cells via NF-κB and ERK1/2 inactivation

We identified a bioactive herbal medicine with anti-inflammatory activity from an ethanol extract derived from the bark of Dioscorea batatas DECNE (BDB) in RAW264.7 cells. We examined the effects of BDB on nitric oxide (NO) and prostaglandin E₂ (PGE₂) production in LPS-induced RAW264.7 cells. BDB consistently inhibited both NO and PGE₂ production in a dose-dependent manner, with an IC₅₀ of 87–71 μg/ml, respectively. The reduction of NO and PGE₂ production were accompanied by a reduction in iNOS and COX-2 protein expression, as evaluated by Western blotting. To evaluate the action mode of BDB and its ability to inhibit iNOS and COX-2 protein expression, we assessed the effects of BDB on nuclear factor-κB (NF-κB) DNA-binding activity, NF-κB-dependent reporter gene activity, inhibitory factor-κB (IκB) phosphorylation and degradation, and p65 nuclear translocation. BDB suppressed DNA-binding activity and reporter gene activity as well as translocation of the NF-κB p65 subunit. BDB also down-regulated IκB kinase (IKK), thus inhibiting LPS-induced both phosphorylation and the degradation of IκBα. In addition, BDB also inhibited the LPS-induced activation of ERK1/2.     

Insulin-like growth factor-1 promotes cell cycle progression via upregulation of cyclin D1 expression through the phosphatidylinositol 3-kinase/nuclear factor-κB signaling pathway in FRTL thyroid cells

Aim： Insulin-like growth factor-1 （IGF-1） is an important hypertrophic and cell cycle progression factor for a number of cell types. It has been proven that IGF-1 is involved in the regulation of thyroid proliferation and cell cycle progression; however, the exact mechanism of this regulation has not been fully elucidated. In the present study, we investigated the effect of IGF-1 on the expression of cyclin D1, an important cell cycle regulatory protein, and a signaling pathway involved in IGF-1＇s effect on cyclinD1 expression in FRTL thyroid cells.
Methods： FRTL thyroid cells were treated with IGF-1 or vector control for 24 h. As appropriate to individual experiments, a phosphatidylinositol 3-kinase （PI3K） inhibitor, LY294002, and/or a nuclear factor-κB （NF-κB） inhibitor, BAY11-7082, were added 1 h prior to IGF-1 treatment. Western blotting was used to detect cyclin D1 protein expression. Immunofluorescence was performed to analyze the expression of IκBα, an NF-κB inhibitory protein. Cell cycle analysis was performed by fluorescence activated cell sorting （FACS）.
Results： IGF-1 increased the cyclin D1 expression in thyroid cells. This increase was blocked by pretreatment with LY294002 or BAY11-7082. Further studies showed that IGF-1 specifically induced NF-κB activity. Treatment with IGF-1 could accelerate cell cycle progression from G0/G1 to S phase, whereas this progression was inhibited by the presence of LY294002 or BAY11-7082.
Conclusion： In summary, the results of the present study show that in FRTL cells, IGF-1 promotes cell cycle progression via an upregulation of cyclin D1 expression, at least partially through the PI3K/NF-κB signaling pathway.     

Alkaloids derived from flowers of Senna spectabilis, (−)-cassine and (−)-spectaline,have antiproliferative activity on HepG2 cells for inducing cell cycle arrest in G1/S transition through ERK inactivation and downregulation of cyclin D1 expression

Cancer is one of the most critical problems of public health in the world and one of the main challenges for medicine in this century. Unfortunately, most patients are diagnosed at advanced stage, when the treatment options are palliative. Consequently, the search for novel therapeutic options is imperative. In the context, the plants represent an important source for discovering of novel compounds with pharmacological potential including antineoplastic agents. Herein, we aimed to investigate in vitro antiproliferative and cytotoxic potentials of an alkaloid mixture derived from Senna spectabilis, (−)-cassine (1) and (−)-spectaline (2). These alkaloids reduced cell viability in a concentration-dependent manner of six tumor cell lines. From initial screening, HepG2 cells were selected for further investigations. We show that alkaloids 1/2 have an important antiproliferative activity on HepG2 cells due to their ability in inducing cell cycle arrest in G1/S transition. This effect was associated to ERK inactivation and down-regulation of cyclin D1 expression. In addition, we evidenced a disruption of the microfilaments and microtubules in a consequence of the treatment. Taken together, the data showed by the first time that alkaloids 1/2 strongly inhibit cell proliferation of hepatocellular carcinoma cells. Therefore, they represent promise antitumor compounds against liver cancer and should be considered for further anticancer in vivo studies.     

Cordycepin (3′-deoxyadenosine) inhibits the growth of B16-BL6 mouse melanoma cells through the stimulation of adenosine A3 receptor followed by glycogen synthase kinase-3β activation and cyclin D1 suppression

Cordyceps sinensis, a parasitic fungus on the larvae of Lepidoptera, has been used as a traditional Chinese medicine. We previously reported that the growth of B16-BL6 mouse melanoma (B16-BL6) cells was inhibited by cordycepin (3'-deoxyadenosine), an active ingredient of C. sinensis, and its effect was antagonized by MRS1191, a selective adenosine A3 receptor antagonist. In this study, the radioligand binding assay using [125I]-AB-MECA (a selective adenosine A3 receptor agonist) has shown that B16-BL6 cells express adenosine A3 receptors and that cordycepin binds to these receptors. We also confirmed the involvement of adenosine A3 receptors in the action of cordycepin using MRS1523 and MRS1220, specific adenosine A3 receptor antagonists. Next, indirubin, a glycogen synthase kinase-3beta (GSK-3beta) inhibitor, antagonized the growth suppression induced by cordycepin. Furthermore, the level of cyclin D1 protein in B16-BL6 cells was decreased by cordycepin using Western blot analysis. In conclusion, this study demonstrated that cordycepin inhibits the proliferation of B16-BL6 cells by stimulating adenosine A3 receptors followed by the Wnt signaling pathway, including GSK-3beta activation and cyclin D1 inhibition.     

<Emphasis Type="Italic">Atractylodes japonica</Emphasis> Koidzumi inhibits the production of proinflammatory cytokines through inhibition of the NF-κB/IκB signal pathway in HMC-1 human mast cells

The rhizome of Atractylodes japonica Koidzumi (AJK) has been used in traditional medicine for treatment of arthritis, bronchitis and respiratory infectious disease, whereas its effects on inflammatory reactions have not been unknown recently. In this study, the effects of AJK on allergic inflammation and its signaling were investigated in the induced human mast cells and animal model. This study showed that ethanol extract of AJK interestingly suppressed the production and mRNA expression of TNF-α, IL-6 and IL-8, as important inflammatory cytokines. Furthermore, AJK inhibited the nuclear translocation of nuclear factor (NF)-κB through inhibition of the phosphorylation of IB-κ, which was additionally elucidated by NF-κB promoter-mediated luciferase activity. In addition, the phosphorylation of ERK was increased in pretreatment with AJK, whereas there was no change in JNK and p38 MAPK. However, AJK showed no effects on anti-DNP IgE-mediated in vivo PCA reaction and histamine release, as key events of mast cell-mediated immediate allergic reactions. These results suggest that AJK might be involved in not early-phase but transition to late-phase reactions of allergic inflammation and could modulate through other signal pathways. Taken together, AJK could be used as a treatment for mast cell mediated late-phase/chronic allergic inflammatory reactions.