Inhibition Of MAPK Signaling Pathways Research Articles

Abrus cantoniensis Hance alleviates APAP-triggered acute liver damage via inhibiting the MAPK and NF-κB signaling pathways in mice

Abrus cantoniensis Hance (AC) is popularly consumed as a kind of medicine homologous food plant. This paper was to examine the hepatoprotective effects and mechanism of AC against liver damage triggered by APAP. Results displayed that AC extract could significantly reduce AST and ALT activities and alleviate histopathological injury via attenuating oxidative stress, hepatocyte apoptosis, and inflammation. In vitro, AC extract inhibited the ROS production and apoptosis by inhibiting MAPK signaling pathway in APAP-induced HepG2. Inflammation was relieved via blocking NF-κB signaling pathways in LPS-induced THP-1 cell. Furthermore, we found that AC extract was capable of regulating the expression of APAP metabolism-related enzymes, thus promoting the excretion and detoxification of APAP. Finally, a reliable UPLC-MS/MS method was set up for the chemical profiling of AC extract. These results indicated that AC is expected to be developed as a functional food or health product for the prevention and treatment of APAP poisoning.

Deoxycholic acid inhibits ASFV replication by inhibiting MAPK signaling pathway

African swine fever (ASF) is an acute, febrile, highly contagious infection of pigs caused by the African swine fever virus (ASFV). The purpose of this study is to understand the molecular mechanism of ASFV infection and evaluate the effect of DCA on MAPK pathway, so as to provide scientific basis for the development of new antiviral drugs. The transcriptome analysis found that ASFV infection up-regulated the IL-17 and MAPK signaling pathways to facilitate viral replication. Metabolome analysis showed that DCA levels were up-regulated after ASFV infection, and that exogenous DCA could inhibit activation of the MAPK pathway by ASFV infection and thus inhibit viral replication. Dual-luciferase reporter assays were used to screen the genes of ASFV and revealed that I73R could significantly up-regulate the transcription level of AP-1 transcription factor in the MAPK pathway. Confocal microscopy demonstrated that I73R could promote AP-1 entry into the nucleus, and that DCA could inhibit the I73R-mediated nuclear entry of AP-1, inhibiting MAPK pathway, and I73R interacts with AP-1. These results indicated that DCA can inhibit ASFV-mediated activation of the MAPK pathway, thus inhibiting ASFV replication. This study provides a theoretical basis for research on ASF pathogenesis and for antiviral drug development.

Network pharmacology and experimental validation of effects of total saponins extracted from Abrus cantoniensis Hance on acetaminophen-induced liver injury

Ethnopharmacological relevanceAbrus cantoniensis Hance (AC), an abrus cantoniensis herb, is a Chinese medicinal herb used for the treatment of hepatitis. Total saponins extracted from AC (ACS) are a compound of triterpenoid saponins, which have protective properties against both chemical and immunological liver injuries. Nevertheless, ACS has not been proven to have an influence on drug-induced liver injury (DILI). Aim of the studyThis study used network pharmacology and experiments to investigate the effects of ACS on acetaminophen (APAP)-induced liver injury. Materials and methodsThe targets associated with ACS and DILI were obtained from online databases. Cytoscape software was utilized to construct a “compound-target” network. In addition, Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were used to analyze the related signaling pathways impacted by ACS. AutoDock Vina was utilized to evaluate the binding affinity between bioactive compounds and the key targets. To validate the findings of network pharmacology, in vitro and in vivo experiments were conducted. Cell viability assay, transaminase activity detection, immunofluorescence assay, immunohistochemistry staining, RT-qPCR, and western blotting were utilized to explore the effects of ACS. Results25 active compounds and 217 targets of ACS were screened, of which 94 common targets were considered as potential targets for ACS treating APAP-induced liver injury. GO and KEGG analyses showed that the effects of ACS exert their effects on liver injury through suppressing inflammatory response, oxidative stress, and apoptosis. Molecular docking results demonstrated that core active compounds of ACS were successfully docked to core targets such as CASP3, BCL2L1, MAPK8, MAPK14, PTGS2, and NOS2. In vitro experiments showed that ACS effectively attenuated APAP-induced damage through suppressing transaminase activity and attenuating apoptosis. Furthermore, in vivo studies demonstrated that ACS alleviated pathological changes in APAP-treated mice and attenuated inflammatory response. Additionally, ACS downregulated the expression of iNOS, COX2, and Caspase-3, and upregulated the expression of Bcl-2. ACS also suppressed the MAPK signaling pathway. ConclusionsThis study demonstrated that ACS is a hepatoprotective drug through the combination of network pharmacology and in vitro and in vivo experiments. The findings reveal that ACS effectively attenuate APAP-induced oxidative stress, apoptosis, and inflammation through inhibiting the MAPK signaling pathway. Consequently, this research offers novel evidence supporting the potential preventive efficacy of ACS.

Front Cover: Anti‐Inflammatory Effects of New Naphthyridine from Sponge Aaptos suberitoides in LPS‐Stimulated RAW 264.7 Macrophages via Regulation of MAPK and Nrf2 Signaling Pathways (Chem. Biodiversity 6/2023)

Chemistry & BiodiversityEarly View e202300701 Cover PictureFree Access Anti-Inflammatory Effects of New Naphthyridine from Sponge Aaptos suberitoides in LPS-Stimulated RAW 264.7 Macrophages via Regulation of MAPK and Nrf2 Signaling Pathways First published: 19 May 2023 https://doi.org/10.1002/cbdv.202300701AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Graphical Abstract Front Cover. Two new naphthyridine compounds, 4-methoxycarbonyl-5-oxo-1,6-naphthyridine (1) and 5-methoxycarbonyl-4-oxo-1,6-naphthyridine (2), were isolated from the MeOH extracts of sponge, Aaptos suberitoides, collected in South Sea, China. Their structures were determined by spectroscopic methods. And the structure of compound 1 was further confirmed via single crystal X-ray diffraction analysis. This is the first report of an anti-inflammatory compound isolated from the sponge genus Aaptos. Biological assays and mechanism research have found that compound 1 can significantly inhibited the production of NO in RAW264.7 cells stimulated by LPS, and exerted anti-inflammatory effects by activating Nrf2/HO-1 and inhibiting MAPK signaling pathways as presented by Meng-Shan Liu et al. in their research article at 10.1002/cbdv.202300410. Early ViewOnline Version of Record before inclusion in an issuee202300701 RelatedInformation

Protective effect of glucosamine on zearalenone-induced reproductive toxicity and placental dysfunction in mice.

This study was conducted to determine the effects of glucosamine (GlcN) on zearalenone (ZEA)-induced reproductive toxicity and placental dysfunction in mice. The pregnant mice were randomly divided into one of the four groups, such as the control group, the ZEA group, the GlcN group, and the GlcN plus ZEA group. Reproductive toxicity was induced by consecutive gavages of ZEA at 5mg/kg body weight during gestational days (GDs 0-14) and in the presence or absence of oral administration of GlcN (0.5mM). The results showed that GlcN significantly alleviated the decrease of growth performance induced by ZEA exposure of pregnant mice. Meanwhile, ZEA ingestion significantly reduced the number and weight of fetuses, and reduction of placenta weight. Moreover, results of blood biochemical markers indicated that ZEA exposure led to increased oxidative stress levels in pregnant mice. Further analyses demonstrated that ZEA inhibited placental development, resulted in placental inflammation, increased the expression of pro-apoptotic proteins, and decreased the expression of placental tight junction proteins, which were reversed by the administration of GlcN. Results of western blot revealed that GlcN reversed ZEA-mediated phenotype by activating PI3K, while inhibiting MAPK signaling pathway. All these findings showed that GlcN was effective in the protection against ZEA-induced placental dysfunction and reproductive toxicity in pregnant mice. Supplementation of GlcN might be potential nutritional intervention with an ability to alleviate ZEA-induced toxicity in pregnant mice.

Vindoline ameliorates intestinal barrier damage in Crohn's disease mice through MAPK signaling pathway.

Intestinal inflammation and intestinal barrier damage are important pathological changes in Crohn's disease (CD). Vindoline is a natural monomer with anti-inflammatory effects. We employed CD model mice to explore the effect of Vindoline on CD-like colitis and the possible mechanism. Il-10-deficient (Il-10-/- ) mice and wild-type (WT) mice (both aged 15 weeks, male) were used to explore the effect of Vindoline on colitis and intestinal barrier damage, as well as macrophage-mediated inflammation. Bone-marrow-derived macrophages (BMDMs) and colonic organoids from mice were used to explore the inhibitory effect of Vindoline on macrophage-mediated inflammation and the protective effect on inflammation-induced intestinal barrier damage as well as the possible mechanism. We found that Vindoline significantly ameliorated colitis in CD mice, as evidenced by increased weight change and colon length and decreased the colon macroscopic injury score, histological inflammatory score, and the expression of pro-inflammatory mediators. Vindoline also protected against intestinal barrier damage in CD mice. Furthermore, Vindoline inhibited macrophage-mediated inflammation and protected against inflammation-induced intestinal barrier damage in the coculture system. In addition, Vindoline ameliorated colitis in CD mice by protecting against inflammation-induced intestinal barrier damage, which may be caused by inhibition of MAPK signaling pathway. This protective effect suggests that Vindoline has potential value for clinical application in the treatment of CD.

SEC61G Promotes Cervical Cancer Proliferation by Activating MAPK Signaling Pathway.

Objective The abnormal expression of SEC61G plays an important role in the development of various tumors. This study explored the effects of SEC61G on MAPK signaling pathway and proliferation of cervical cancer (CC) cells. Methods shRNA was used to inhibit the expression of SEC61G and EdU to observe its effect on the proliferation of CC cell SiHa. The effect of SEC61G on invasion was evaluated by Transwell assay. TCGA database was used to analyze the influence of high or low SEC61G expression level on the overall survival of CC patients. Western blot was used to detect the expressions of SEC61G, p-RAF1, Raf1, p-MEK1/2, MEK1/2, and p-ERK1/2 in cells. SiHa cells overexpressing SEC61G (SiHa-SEC61G) and control group (SiHa-mock) were subcutaneously implanted in nude mice. The tumor growth curve was measured at the specified time points between SiHa-SEC61G and SiHa-mock. The inhibitory effect of gefitinib on SEC61G was further evaluated. Results In patients with CC, high SEC61G expression predicted poor prognosis. Silencing SEC61G inhibited proliferation and invasion of CC cells in vitro. Overexpression of SEC61G can promote the proliferation and invasion of CC cells in vitro. Meanwhile, overexpression of SEC61G promoted the proliferation of CC xenografts. Knocking down SEC61G can inhibit MAPK signaling pathway. Gefitinib can inhibit CC proliferation and tumor growth by SEC61G. Conclusion SEC61G is highly expressed in CC and has poor prognosis. Inhibition of SEC61G expression can effectively inhibit the growth and proliferation of human CC cells. The mechanism may be related to the inhibition of MAPK signaling pathway.

Celastrol attenuates amphiregulin expression by inhibiting MAPK signaling pathway in triple-negative breast cancer cells

BackgroundAmphiregulin (AREG) plays an essential role in the metastasis and angiogenesis of various cancers. PurposeThe objective of this study was to investigate the pharmacological effects of celastrol on AREG expression in triple-negative breast cancer (TNBC) cells. MethodsWe analyzed the prognostic value of AREG, EGF, TGFA, and HB-EGF mRNA expression in TNBC patients. Cell proliferation was analyzed by MTT assay and colony-forming assay. Levels of protein and gene expression were analyzed by ELISA, Western blotting, confocal microscopy, and real-time PCR, respectively. The expression of angiogenic proteins was analyzed by using the Human angiogenesis array kit. Cell invasiveness was analyzed by Boyden chamber assay. ResultsOur results showed that abnormal AREG induction remarkably decreased the relapse-free survival (RFS) rate of TNBC patients, whereas epidermal growth factor (EGF), transforming growth factor-alpha (TGFA), or heparin-binding EGF-like growth factor (HBEGF) demonstrated no effect on RFS rate. In addition, the growth of TNBC cells was prevented by drugs targeting EGFR such as neratinib or lapatinib. On the contrary, cell growth and invasion were enhanced by AREG treatment. Interestingly, celastrol reduced AREG expression and the growth of TNBC cells. Furthermore, we found that levels of AREG expression were reduced by a potent inhibitor of MEK1/2, binimetinib (BIN). Our results showed that celastrol significantly decreased the levels of ERK phosphorylation in TNBC cells. Finally, we observed that celastrol also suppressed the AREG-induced EGFR signaling pathway. Taken together, these results suggest that celastrol can downregulate AREG expression by inhibiting the MEK/ERK signaling pathway. In addition, the AREG-induced EGFR signaling pathway was inhibited by celastrol. ConclusionCelastrol can be an effective drug for treating TNBC by inhibiting AREG/EGFR signaling pathways.

Protective Effects and Molecular Mechanism of Total Flavonoids from Lycium Barbarum Leaves on Photoaged Human Dermal Fibroblasts.

Objective To investigate the effects and corresponding mechanisms of total flavonoids (TFL) from Lycium barbarum leaves on photoaged human dermal fibroblasts (HDFs). Methods Crude TFL was extracted with 70% ethanol, and a Rutin standard curve was drawn using the sodium nitrite-aluminum nitrate-sodium hydroxide colorimetry method to calculate its yield and mass concentration. After that, the photoaging HDFs model was established by UVA combined with 8-MOP. CCK-8 was performed to assess the influence of TFL on the proliferation of HDFs and photoaging HDFs. β-galactosidase (SA-β-gal) staining and activity assays were performed to evaluate the activity of SA-β-gal and the rate of SA-β-gal-positive cells in HDFs cells. The level of skin ECM proteins and oxidative stress-related substances in HDFs cells of each group was determined by ELISA and biochemical detection, respectively. Apoptosis of HDFs in each group was assessed by flow cytometry. The expressions of MAPK signaling pathway-related proteins in HDFs were detected by western blot. Results The yield rate of TFL extracted by 70% ethanol was 41.9%, and its purity rate was 34.6%. TFL at 25, 50, and 100 μg/mL was able to greatly promote the proliferation of HDFs. A photoaged HDFs model was successfully constructed by combining UVA irradiation at 9 J/cm2 and 8-MOP at 50 mg/L. TFL treatment could significantly inhibit apoptosis, SA-β-gal-positive cell staining rate, SA-β-gal activity, lactate dehydrogenase (LDH) leakage, and malondialdehyde (MDA) content in photoaged HDFs. Further, TFL increased the proliferative activity, superoxide dismutase (SOD) activity, catalase (CAT) activity, type I collagen (Col I), hydroxyproline (HYP), and hyaluronic acid (HA) level of photoaged HDFs in a dose-dependent manner. Additional experiments suggested that TFL played a protective role by downregulating MAPK signaling pathway activity in photoaged HDFs cells. Conclusion TFL could inhibit oxidative stress and apoptosis, promote cell proliferation and the level of ECM-related component proteins, and participate in antiphotoaging in a concentration-dependent manner. The protective role of TFL in photoaged HDFs might be related to its inhibition of MAPK signaling pathways.

Metformin Attenuates Ischemia-Reperfusion Injury in a Rat Lung Transplantation Model

<h3>Purpose</h3> Ischemia-reperfusion injury (IRI), an inevitable acute lung injury during lung transplantation (LTx), contributes to the development of severe complications and limits the success of LTx. Metformin exerts beneficial actions to alleviate acute lung injury induced by a diversity of factors. However, the effect of metformin on IRI has not yet been elucidated in LTx. In this study, we conducted an animal experiment to investigate the effects of metformin on IRI and explore the possible therapeutic mechanism. <h3>Methods</h3> LTx was performed on five groups of rats: sham operation (SM), ischemia-reperfusion (IR), metformin-IR (MI), metformin-anisomycin (MAPK activator)-IR (MAI), metformin-phorbol 12-myristate 13-acetate (PMA, NETosis activator)-IR (MPI). In MI, MAI, and MPI groups, metformin (400 mg/kg) was administered by gavage 72h, 48h, 24h, and 30min before cold ischemia. Anisomycin (15 mg/kg) and PMA (3 ug/kg) were intraperitoneally injected 30min before cold ischemia in MAI and MPI groups, respectively. Each group (n = 5) received a cold ischemic time of 1.5h followed by LTx except the SM group (n = 5). After reperfusion for two hours, recipient rats were sacrificed for further examination of arterial blood gas analysis, histopathology examination, and lung wet-to-dry weight (W/D) ratio. <h3>Results</h3> Compared to the IR group, the MI group showed significantly better PaO₂/FiO₂ ratio and SaO₂, lower W/D ratio, perivascular cuff area/vessel area (P/V) ratio, lung injury score, and red blood cell (RBC) infiltration (all <i>P</i> < 0.05). After the administration of MAPK signaling pathway and NETosis activators, significant deterioration was found in the MAI group with higher lung injury score, RBC infiltration, and W/D ratio (all <i>P</i> < 0.05) and the MPI group with lower SaO₂ and higher lung injury score and P/V ratio (all <i>P</i> < 0.05) (Figure 1). <h3>Conclusion</h3> Metformin attenuates IRI and may be attributed to inhibition of MAPK signaling pathway and NETosis in rat LTx.

Fish Collagen Peptides Protect against Cisplatin-Induced Cytotoxicity and Oxidative Injury by Inhibiting MAPK Signaling Pathways in Mouse Thymic Epithelial Cells.

Thymic epithelial cells (TECs) account for the most abundant and dominant stromal component of the thymus, where T cells mature. Oxidative- or cytotoxic-stress associated injury in TECs, a significant and common problem in many clinical settings, may cause a compromised thymopoietic capacity of TECs, resulting in clinically significant immune deficiency disorders or impairment in the adaptive immune response in the body. The present study demonstrated that fish collagen peptides (FCP) increase cell viability, reduce intracellular levels of reactive oxygen species (ROS), and impede apoptosis by repressing the expression of Bax and Bad and the release of cytochrome c, and by upregulating the expression of Bcl-2 and Bcl-xL in cisplatin-treated TECs. These inhibitory effects of FCP on TEC damage occur via the suppression of ROS generation and MAPK (p38 MAPK, JNK, and ERK) activity. Taken together, our data suggest that FCP can be used as a promising protective agent against cytotoxic insults- or ROS-mediated TEC injury. Furthermore, our findings provide new insights into a therapeutic approach for the future application of FCP in the prevention and treatment of various types of oxidative- or cytotoxic stress-related cell injury in TECs as well as age-related or acute thymus involution.

Gamma-oryzanol protects human liver cell (L02) from hydrogen peroxide-induced oxidative damage through regulation of the MAPK/Nrf2 signaling pathways.

Gamma-oryzanol (Orz), a mixture of the ferulic acid ester of triterpene alcohols and phytosterols, was found abundantly in rice bran and rice bran oil which could be available and served as an antioxidant. The present study was to explore the potential protective effects of Orz on oxidative stress and cell apoptosis in human hepatic cells (L02 cells) induced by hydrogen peroxide (H2 O2 ). Flow cytometry detection and Hoechst 33258 staining showed that Orz significantly restored cell cycle and ameliorated apoptosis in H2 O2 -challenged L02 cells. Orz pretreatment inhibited H2 O2 -induced cell apoptosis by increasing the scavenging of hydroxyl radicals (OH·), and efficiently decreasing the production of nitric oxide (NO). Moreover, a loss of total antioxidant capacity (T-AOC) and adenosine triphosphatase (ATPase) were enhanced in H2 O2 -mediated L02 cells pretreated with Orz. Furthermore, preincubation with Orz reduced H2 O2 -mediated the proapoptotic protein of Bak expression and the phosphorylation of ASK1, p38, JNK, and ERK, and increased the anti-apoptotic protein of Bcl-xl expression and anti-oxidative stress proteins of Nrf2 and HO-1 expression. The findings suggested that Orz exerts the cytoprotective effects in H2 O2 -induced L02 cells apoptosis by ameliorating oxidative stress via inhibiting MAPK signaling pathway and activating Nrf2 signaling pathway. PRACTICAL APPLICATIONS: Gamma-oryzanol (Orz), a mixture of the ferulic acid ester of triterpene alcohols and phytosterols, was found abundantly in rice bran and rice bran oil which could be availably served as an antioxidant. In this study, it was found that Orz exerts the cytoprotective effects in H2 O2 -induced L02 cell apoptosis by ameliorating oxidative stress via the inhibition of MAPK signaling pathway and the activation of Nrf2 signaling pathway, which provides a theoretical basis for dietary adding natural products to prevent or treat oxidative stress-related diseases.

Grape Seed Proanthocyanidins Exert a Radioprotective Effect on the Testes and Intestines Through Antioxidant Effects and Inhibition of MAPK Signal Pathways.

The testes and intestines are highly sensitive to ionizing radiation. Low-dose radiation can cause infertility and enteritis. However, there is a lack of safe and efficient radioprotective agents. This study aims to investigate the radioprotective effects of grape seed proanthocyanidins (GSPs) on testicular and intestinal damage induced by ionizing radiation. In vitro, GSPs reduced the apoptosis and proliferation inhibition of mouse testicular stromal cells TM3 and human small intestinal crypt epithelial cells HIEC induced by ionizing radiation, and alleviated DNA double-strand breaks. In vivo, GSPs ameliorated the pathological damage of the testes and intestines induced by ionizing radiation, and protected the endocrine function of the testes and the barrier function of the intestines. In addition, we preliminarily proved that the radioprotective effect of GSPs is related to its antioxidant effect and inhibition of MAPK signaling pathways. Our results indicate that GSPs are expected to be a safe and effective radioprotective drug.

Huanglian Jiedu Decoction Exerts Antipyretic Effect by Inhibiting MAPK Signaling Pathway.

Aim The aim of this study was to explore the antipyretic effect and potential mechanism of Huanglian Jiedu Decoction (HLJDD) on LPS-induced fever in rats. Materials and Methods The fever rat model was established by LPS. Anal temperature of rats was measured every 1 hour after modeling. TNF-α, IL-6, PGE2, and cAMP in rat serum or hypothalamus tissue were detected by ELISA kit. In order to explore the potential active ingredients and mechanism of antipyretic effect of HLJDD, we predicted the underlying antipyretic mechanism by using network pharmacology and then verified its mechanism by Western Blotting. Results The results showed that HLJDD can alleviate LPS-induced fever in rats. The expression levels of TNF-α, IL-6, PGE2, and cAMP in the treatment group were significantly lower than those in the model group. Western Blotting results showed that the protein expression of p-ERK, p-JNK, and p-P38 was significantly inhibited. Conclusion The findings suggest that HLJDD has a good antipyretic effect on LPS-induced fever in rats, which may be closely related to the inhibition of MAPK signaling pathway.

An Integration of Network Pharmacology and Experimental Verification to Investigate the Mechanism of Guizhi to Treat Nephrotic Syndrome.

Background: Guizhi has the pharmacological activity of anti-inflammatory. However, the effect mechanism of Guizhi against nephrotic syndrome (NS) remains unclear. A network pharmacological approach with experimental verification in vitro and in vivo was performed to investigate the potential mechanisms of Guizhi to treat NS. Methods: Active compounds and potential targets of Guizhi, as well as the related targets of NS were obtained from the public databases. The intersecting targets of Guizhi and NS were obtained through Venny 2.1.0. The key targets and signaling pathways were determined by protein-protein interaction (PPI), genes ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) analysis. And the overall network was constructed with Cytoscape. Molecular docking verification was carried out by AutoDock Vina. Finally, in vitro and in vivo experiments were performed to verify the mechanism of Guizhi to treat NS. Results: 63 intersecting targets were obtained, and the top five key targets mainly involed in NF- Kappa B and MAPK signaling pathway. In the overall network, cinnamaldehyde (CA) was the top one active compound with the highest degree value. The molecular docking showed that the top five key targets were of good binding activity with the active components of Guizhi. To in vitro experiment, CA, the main active component of Guizhi, inhibited the secretion of IL-1β, IL-6, TNF-α in LPS challenged RAW264.7 cells, and down regulated the protein expression of p-NF-κB p65 and p-p38 MAPK in LPS challenged RAW264.7 cells. In vitro experiment showed that, 24 urinary protein and renal function were increased in ADR group. To western blot, CA down regulated the protein expression of p-p38 MAPK in rats of adriamycin-induced nephropathy. Conclusion: CA might be the main active component of Guizhi to treat NS, and the underlying mechanism might mainly be achieved by inhibiting MAPK signaling pathway.

Immunostimulatory activity and anti-obesity activity of Hibiscus manihot leaves in mouse macrophages, RAW264.7 cells and mouse adipocytes, 3T3-L1 cells

• HML activates the production of immunostimulatory factors and phagocytosis in RAW264.7 cells. • HML induces MAPK/TLR2/4-dependent production of immunostimulatory factors in RAW264.7 cells. • HML inhibits the accumulation of lipid and triglyceride in 3T3-L1 cells. • HML decreases the levels of differentiation and adipogenesis-related protein in 3T3-L1 cells. In this study, we investigated whether Hibiscus manihot leaves (HML) exhibits immune-enhancing activity and anti-obesity in RAW264.7 and 3T3-L1 cells. HML increased the production of inflammatory molecules, cell viability and phagocytosis in RAW264.7 cells. TLR2 and TLR4 blocked HML-mediated production of inflammatory molecules in RAW264.7 cells. In addition, the inhibition of MAPK signaling pathway reduced HML-mediated production of inflammatory molecules and the activation of MAPK signaling pathway by HML suppressed the inhibition of TLR2/4. HML reduced the lipid accumulation and TG contents in 3T3-L1 cells. HML inhibited the protein expressions such as CEBPα, PPARγ, perilipin-1, adiponectin and FABP4 related to the lipid accumulation of the mature adipocytes. In addition, HML reduced CEBPα and PPARγ during the differentiation process from preadipocytes to mature adipocytes.

Blocking tumor necrosis factor-α delays progression of chronic obstructive pulmonary disease in rats through inhibiting MAPK signaling pathway and activating SOCS3/TRAF1.

The present study was conducted in order to study the detailed molecular mechanism of tumor necrosis factor (TNF)-α in chronic obstructive pulmonary disease (COPD). The rats were treated with cigarette smoke (CS) and lipopolysaccharide (LPS) to establish the COPD model. Next, the changes in lung injury in COPD rats with TNF-α knockdown was tested. Meanwhile, the regulation of TNF-α on MAPK pathway and its downstream molecules (SOCS3/TRAF1) was determined by western blotting. On this basis, the activation of MAPK and inhibition of SOCS3/TRAF1 was also examined. Subsequently, the lung function was tested with the plethysmograph, the cells of bronchoalveolar lavage fluid was counted and classified. Furthermore, lung tissue sections were stained with hematoxylin and eosin to verify whether the treatment of MAPK pathway and downstream molecules affected the effect of TNF-α knockdown on COPD. The present study showed that TNF-α knockdown could alleviate the decrease in the function and inflammatory injury of the lungs of rats with COPD. Western blot analysis verified that TNF-α knockdown could inhibit the activation of MAPK pathway and increase the expression of SOCS3/TRAF1. The following experimental results showed that the relief of lung injury caused by TNF-α knockdown could be deteriorated by activating MAPK pathway. It was also found that the symptom of COPD was decreased following transfection with sh-TNF-α but worsened by SOCS3/TRAF1 knockdown. Overall, TNF-α knockdown inhibited the activation of MAPK pathway and increased the expression of SOCS3/TRAF1, thus delaying the process of COPD.

Baicalin Alleviates Oxidative Stress and Inflammation in Diabetic Nephropathy via Nrf2 and MAPK Signaling Pathway.

BackgroundOxidative stress and inflammation play essential roles in the development and progression of diabetic nephropathy (DN). Baicalin (BAI), a natural flavonoid, has been showed to have a renoprotective effect in various renal diseases. However, its underlying mechanisms in DN remain unclear. In this study, we explored the potential effects and underlying mechanisms of BAI on DN using a spontaneous DN model.MethodsThe protective effects of BAI on DN have been evaluated by detecting DN-related biochemical indicators, kidney histopathology and cell apoptosis. After that, we examined the level of renal oxidative stress and inflammation to explain BAI’s renoprotective effects. Then, Nrf2 pathway was tested to clarify its antioxidant activity, and kidney transcriptomics was conducted to elucidate its anti-inflammatory activity. Finally, Western blot was applied for final mechanism verification.ResultsOur results found that BAI effectively ameliorated diabetic conditions, proteinuria, renal histopathological changes and cell apoptosis in DN. BAI significantly improved the kidney levels of glutathione peroxidase (GSH-PX), superoxide dismutase (SOD) and catalase (CAT), and reduced malondialdehyde (MDA) level. Meanwhile, the infiltration of inflammatory cells including T-lymphocytes, T-helper cells, neutrophils and macrophages, and the mRNA levels of pro-inflammatory cytokines (IL-1β, IL-6, MCP-1 and TNFα) were also obviously inhibited by BAI. Afterward, Western blot found that BAI significantly activated Nrf2 signaling and increased the expression of downstream antioxidant enzymes (HO-1, NQO-1). Kidney transcriptomics revealed that the inhibition of MAPK signaling pathway may contribute to BAI’s anti-inflammatory activity, which has also been verified in later experiment. BAI treatment did obviously inhibit the activation of canonical pro-inflammatory signaling pathway MAPK family, such as Erk1/2, JNK and P38.ConclusionIn summary, our data demonstrated that BAI can treat DN by alleviating oxidative stress and inflammation, and its underlying mechanisms were associated with the activation of Nrf2-mediated antioxidant signaling pathway and the inhibition of MAPK-mediated inflammatory signaling pathway.

Puerarin Ameliorates Caerulein-Induced Chronic Pancreatitis via Inhibition of MAPK Signaling Pathway.

Pancreatic fibrosis is one of the most important pathological features of chronic pancreatitis (CP), and pancreatic stellate cells (PSCs) are considered to be the key cells. Puerarin is the most important flavonoid active component in Chinese herb Radix Puerariae, and it exhibited anti-fibrotic effect in various fibrous diseases recently. However, the impact and molecular mechanism of puerarin on CP and pancreatic fibrosis remain unknown. This study systematically investigated the effect of puerarin on CP and pancreatic fibrosis in vivo and in vitro. H&E staining, Sirius Red staining, qRT-PCR and Western blotting analysis of fibrosis and inflammation related genes of pancreatic tissues showed that puerarin notably ameliorated pancreatic atrophy, inflammation and fibrosis in a model of caerulein-induced murine CP. Western blotting analysis of pancreatic tissues showed the phosphorylation level of MAPK family proteins (JNK1/2, ERK1/2 and p38 MAPK) significantly increased after modeling of cerulein, while puerarin could inhibit their phosphorylation levels to a certain extent. We found that puerarin exerted a marked inhibition on the proliferation, migration and activation of PSCs, determined by CCK-8 assay, transwell migration assay, scratch wound-healing assay and expression levels of α-SMA, Fibronectin, Col1α1 and GFAP. Western blotting result demonstrated that puerarin markedly inhibited the phosphorylation of MAPK family proteins (JNK1/2, ERK1/2 and p38 MAPK) of PSCs in a dose-dependent manner whether or not stimulated by platelet-activating factor. In conclusion, the present study showed that puerarin could be a potential therapeutic candidate in the treatment of CP, and the MAPK pathway might be its important target.

MicroRNA-126 Attenuates the Effect of Chemokine CXCL8 on Proliferation, Migration, Apoptosis, and MAPK-Dependent Signaling Activity of Vascular Endothelial Cells Cultured in a Medium with High Glucose Concentration.

We studied the mechanisms by which microRNA-126 regulates proliferation and migration of human umbilical vein endothelial cells (HUVEC) cultured in a medium with high glucose concentration and treated with chemokine CXCL8. Cell proliferation, apoptosis, and migration were analyzed by the CCK-8 assay, Annexin V-PI staining, and Transwell assay, respectively. The ratios of p-ERK/ERK, p-P38/P38, p-JNK/JNK were determined by ELISA. HUVEC cells cultured in the presence of high glucose concentration (30 mmol/ml) and treated with CXCL8 (50 ng/ml) demonstrated more intensive proliferation, migration, and p-ERK/ERK, p-P38/P38, and p-JNK/JNK ratios and significantly lower apoptosis rate than control cells (high glucose, no treatment) and cells treated with CXCL8 and transfected with microRNA-126-mimic. Thus, microRNA-126 regulates proliferation and migration of HUVEC cells cultured in the presence of high glucose concentrations and treated with CXCL8 through inhibition of MAPK signaling pathway.