Displaying publications 1 - 20 of 26 in total

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  1. Ong JY, Yong PV, Lim YM, Ho AS
    Life Sci, 2015 Aug 15;135:158-64.
    PMID: 25896662 DOI: 10.1016/j.lfs.2015.03.019
    The compound 2-methoxy-1,4-naphthoquinone (MNQ) was previously shown to be cytotoxic against several cancer cell lines, but its mode of action is poorly understood. In this study, we aimed to explore the molecular mechanism of MNQ-induced cytotoxicity of A549 lung adenocarcinoma cells.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects*
  2. Dai X, Wang L, Deivasigamni A, Looi CY, Karthikeyan C, Trivedi P, et al.
    Oncotarget, 2017 Feb 21;8(8):12831-12842.
    PMID: 28086233 DOI: 10.18632/oncotarget.14606
    A prior screening programme carried out using MTT assay by our group identified a series of novel benzimidazole derivatives, among which Methyl 2-(5-fluoro-2-hydroxyphenyl)-1H- benzo[d]imidazole-5-carboxylate (MBIC) showed highest anticancer efficacy compared to that of chemotherapeutic agent, cisplatin. In the present study, we found that MBIC inhibited cell viability in different hepatocellular carcinoma (HCC) cell lines without exerting significant cytotoxic effects on normal liver cells. Annexin V-FITC/PI flow cytometry analysis and Western blotting results indicated that MBIC can induce apoptosis in HCC cells, which was found to be mediated through mitochondria associated proteins ultimately leading to the activation of caspase-3. The exposure to MBIC also resulted in remarkable impairment of HCC cell migration and invasion. In addition, treatment with MBIC led to a rapid generation of reactive oxygen species (ROS) and substantial activation of c-Jun-N-terminal kinase (JNK). The depletion of ROS by N-Acetyl cysteine (NAC) partially blocked MBIC-induced apoptosis and JNK activation in HCC cells. Finally, MBIC significantly inhibited tumor growth at a dose of 25 mg/kg in an orthotopic HCC mouse model. Taken together, these results demonstrate that MBIC may inhibit cell proliferation via ROS-mediated activation of the JNK signaling cascade in HCC cells.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects*
  3. Teoh WY, Wahab NA, Sim KS
    Nucleosides Nucleotides Nucleic Acids, 2017 Apr 03;36(4):243-255.
    PMID: 28323520 DOI: 10.1080/15257770.2016.1268693
    This study aims to investigate the mechanisms associated with the antiproliferation effect of guanosine on human colon carcinoma HCT 116 cells. In this study, guanosine induced more drastic cell cycle arrest effect than cell death effect on HCT 116 cells. The cell cycle arrest effect of guanosine on HCT 116 cells appeared to be associated with the increased activation of mitogen-activated protein kinases (MAPK) such as ERK1/2, p38 and JNK. The decrease of AMP-activated protein kinase (AMPK) activation and cyclin D1 expression was also involved. Thus, the antiproliferation of colon cancer cells of guanosine could be mediated by the disruption of MAPK and AMPK pathways.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects
  4. Lee KH, Chow YL, Sharmili V, Abas F, Alitheen NB, Shaari K, et al.
    Int J Mol Sci, 2012;13(3):2985-3008.
    PMID: 22489138 DOI: 10.3390/ijms13032985
    Our preliminary screening has shown that curcumin derivative BDMC33 [2,6-bis(2,5-dimethoxybenzylidene)cyclohexanone] exerted promising nitric oxide inhibitory activity in activated macrophages. However, the molecular basis and mechanism for its pharmacological action is yet to be elucidated. The aim of this study was to investigate the anti-inflammatory properties of BDMC33 and elucidate its underlying mechanism action in macrophage cells. Our current study demonstrated that BDMC33 inhibits the secretion of major pro-inflammatory mediators in stimulated macrophages, and includes NO, TNF-α and IL-1β through interference in both nuclear factor kappaB (NF-κB) and mitogen activator protein kinase (MAPK) signaling cascade in IFN-γ/LPS-stimulated macrophages. Moreover, BDMC33 also interrupted LPS signaling through inhibiting the surface expression of CD-14 accessory molecules. In addition, the inhibitory action of BDMC33 not only restricted the macrophages cell (RAW264.7), but also inhibited the secretion of NO and TNF-α in IFN-γ/LPS-challenged microglial cells (BV-2). The experimental data suggests the inflammatory action of BDMC33 on activated macrophage-like cellular systems, which could be used as a future therapeutic agent in the management of chronic inflammatory diseases.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects*
  5. Subramaniam KS, Tham ST, Mohamed Z, Woo YL, Mat Adenan NA, Chung I
    PLoS One, 2013;8(7):e68923.
    PMID: 23922669 DOI: 10.1371/journal.pone.0068923
    Endometrial cancer is the most commonly diagnosed gynecologic malignancy worldwide; yet the tumor microenvironment, especially the fibroblast cells surrounding the cancer cells, is poorly understood. We established four primary cultures of fibroblasts from human endometrial cancer tissues (cancer-associated fibroblasts, CAFs) using antibody-conjugated magnetic bead isolation. These relatively homogenous fibroblast cultures expressed fibroblast markers (CD90, vimentin and alpha-smooth muscle actin) and hormonal (estrogen and progesterone) receptors. Conditioned media collected from CAFs induced a dose-dependent proliferation of both primary cultures and cell lines of endometrial cancer in vitro (175%) when compared to non-treated cells, in contrast to those from normal endometrial fibroblast cell line (51%) (P<0.0001). These effects were not observed in fibroblast culture derived from benign endometrial hyperplasia tissues, indicating the specificity of CAFs in affecting endometrial cancer cell proliferation. To determine the mechanism underlying the differential fibroblast effects, we compared the activation of PI3K/Akt and MAPK/Erk pathways in endometrial cancer cells following treatment with normal fibroblasts- and CAFs-conditioned media. Western blot analysis showed that the expression of both phosphorylated forms of Akt and Erk were significantly down-regulated in normal fibroblasts-treated cells, but were up-regulated/maintained in CAFs-treated cells. Treatment with specific inhibitors LY294002 and U0126 reversed the CAFs-mediated cell proliferation (P<0.0001), suggesting for a role of these pathways in modulating endometrial cancer cell proliferation. Rapamycin, which targets a downstream molecule in PI3K pathway (mTOR), also suppressed CAFs-induced cell proliferation by inducing apoptosis. Cytokine profiling analysis revealed that CAFs secrete higher levels of macrophage chemoattractant protein (MCP)-1, interleukin (IL)-6, IL-8, RANTES and vascular endothelial growth factor (VEGF) than normal fibroblasts. Our data suggests that in contrast to normal fibroblasts, CAFs may exhibit a pro-tumorigenic effect in the progression of endometrial cancer, and PI3K/Akt and MAPK/Erk signaling may represent critical regulators in how endometrial cancer cells respond to their microenvironment.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects
  6. Mohammed Abdul KS, Rayadurgam J, Faiz N, Jovanović A, Tan W
    J Cell Mol Med, 2020 09;24(18):10924-10934.
    PMID: 32794652 DOI: 10.1111/jcmm.15721
    In the present study, we have investigated potential cardioprotective properties of Isosteviol analogue we recently synthesized and named JC105. Treatment of heart embryonic H9c2 cells with JC105 (10 μM) significantly increased survival of cells exposed to hypoxia-reoxygenation. JC105 (10 μM) activated ERK1/2, DRP1 and increased levels of cardioprotective SUR2A in hypoxia-reoxygenation, but did not have any effects on ERK1/2, DRP1 and/or SUR2A in normoxia. U0126 (10 μM) inhibited JC105-mediated phosphorylation of ERK1/2 and DRP1 without affecting AKT or AMPK, which were also not regulated by JC105. Seahorse bioenergetic analysis demonstrated that JC105 (10 μM) did not affect mitochondria at rest, but it counteracted all mitochondrial effects of hypoxia-reoxygenation. Cytoprotection afforded by JC105 was inhibited by U0126 (10 μM). Taken all together, these demonstrate that (a) JC105 protects H9c2 cells against hypoxia-reoxygenation and that (b) this effect is mediated via ERK1/2. The unique property of JC105 is that selectively activates ERK1/2 in cells exposed to stress, but not in cells under non-stress conditions.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects*
  7. Tahir AA, Sani NF, Murad NA, Makpol S, Ngah WZ, Yusof YA
    Nutr J, 2015;14:31.
    PMID: 25889965 DOI: 10.1186/s12937-015-0015-2
    The interconnected Ras/ERK and PI3K/AKT pathways play a central role in colorectal tumorigenesis, and they are targets for elucidating mechanisms involved in attempts to induce colon cancer cell death. Both ginger (Zingiber officinale) and honey have been shown to exhibit anti-tumor and anti-inflammation properties against many types of cancer, including colorectal cancer. However, there are currently no reports showing the combined effect of these two dietary compounds in cancer growth inhibition. The aim of this study was to evaluate the synergistic effect of crude ginger extract and Gelam honey in combination as potential cancer chemopreventive agents against the colorectal cancer cell line HT29.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects*
  8. Razali NA, Nazarudin NA, Lai KS, Abas F, Ahmad S
    BMC Complement Altern Med, 2018 Jul 16;18(1):217.
    PMID: 30012134 DOI: 10.1186/s12906-018-2223-8
    BACKGROUND: Histamine is a well-known mediator involved in skin allergic responses through up-regulation of pro-inflammatory cytokines. Antihistamines remain the mainstay of allergy treatment, but they were found limited in efficacy and associated with several common side effects. Therefore, alternative therapeutic preferences are derived from natural products in an effort to provide safe yet reliable anti-inflammatory agents. Curcumin and their derivatives are among compounds of interest in natural product research due to numerous pharmacological benefits including anti-inflammatory activities. Here, we investigate the effects of chemically synthesized curcumin derivative, 2,6-bis(2-fluorobenzylidene)cyclohexanone (MS65), in reducing cytokine production in histamine-induced HaCaT cells.

    METHODS: Interleukin (IL)-6 cytokine production in histamine-induced HaCaT cells were measured using enzyme-linked immunosorbent assay (ELISA) and cytotoxicity effects were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Real-time polymerase chain reaction (RT-qPCR) was carried out to determine the inhibitory effects of MS65 on nuclear factor-kappa B (NF-κB) and mitogen activated protein kinase (MAPK) pathways.

    RESULTS: Histamine enhanced IL-6 production in HaCaT cells, with the highest production of IL-6 at 97.41 ± 2.33 pg/mL after 24 h of exposure. MS65 demonstrated a promising anti-inflammatory activity by inhibiting IL-6 production with half maximal inhibitory concentration (IC50) value of 4.91 ± 2.50 μM and median lethal concentration (LC50) value of 28.82 ± 7.56 μM. In gene expression level, we found that MS65 inhibits NF-κB and MAPK pathways through suppression of IKK/IκB/NFκB and c-Raf/MEK/ERK inflammatory cascades.

    CONCLUSION: Taken together, our results suggest that MS65 could be used as a lead compound on developing new medicinal agent for the treatment of allergic skin diseases.

    Matched MeSH terms: MAP Kinase Signaling System/drug effects
  9. Ahmad Hidayat AF, Chan CK, Mohamad J, Abdul Kadir H
    Biomed Pharmacother, 2018 Aug;104:806-816.
    PMID: 29860114 DOI: 10.1016/j.biopha.2018.05.073
    Dioscorea bulbifera, also known as air potato, has been cultivated as food crop mainly in tropical countries in Asia and Australia. The tubers are edible and have often been used in Traditional Chinese Medicine (TCM) and Ayurvedic medicine to treat cancer, diabetes, thyroid disease, and inflammation. This study aimed to investigate the effects of D. bulbifera on HCT116 human colorectal carcinoma cells and to unravel the plausible mechanisms underlying its apoptotic effects. The ethanol crude and fractions (hexane, ethyl acetate and water) of D. bulbifera were subjected to cell viability MTT assay against various cancer cell lines. The lowest IC50 of the extract and fractions on selected cancer cells were selected for further apoptosis assay and western blot analysis. HCT116 cancer cells were treated with D. bulbifera and stained with Annexin/PI or Hoechst 33342/PI for preliminary confirmation of apoptosis. The dissipation of mitochondria membrane potential (MMP) was determined by flow cytometry. The protein expressions of apoptosis-related proteins such as Bcl-2 family, caspases, Fas, PARP, ERK1/2 and JNK were detected by western blot analysis. Moreover, the HCT116 cells were treated with UO126 and SP600125 inhibitors to verify the involvement of ERK1/2 and JNK protein expressions in inducing apoptotic cell death. Based on the result, D. bulbifera ethyl acetate fraction (DBEAF) exhibited the most compelling cytotoxicity on HCT116 cells with an IC50 of 37.91 ± 1.30 µg/mL. The induction of apoptosis was confirmed by phosphatidylserine externalization and chromatin condensation. Depolarization of MMP further conferred the induction of apoptosis was through the regulation of Bcl-2 family proteins. Activation of caspase cascades (caspase-3, -9, -8 and -10) was elicited followed by the observation of cleaved PARP accumulation in DBEAF-treated cells. Furthermore, death receptor, Fas was activated upon exposure to DBEAF. Collective apoptotic evidences suggested the involvement of intrinsic and extrinsic pathways by DBEAF in HCT116 cells. Interestingly, the attenuation of ERK1/2 phosphorylation accompanied by the activation of JNK was detected in DBEAF-treated cells. In conclusion, the findings revealed that DBEAF induced apoptosis through intrinsic and extrinsic pathways involving ERK1/2 and JNK.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects*
  10. Sayem ASM, Giribabu N, Muniandy S, Salleh N
    Biomed Pharmacother, 2017 Dec;96:1016-1021.
    PMID: 29221723 DOI: 10.1016/j.biopha.2017.11.128
    INTRODUCTION: Thyroid hormone is known to play important role during embryo implantation, however mechanisms underlying its actions in uterus during peri-implantation period has not been fully identified. In this study, we hypothesized that thyroid hormone could affect expression of proteins related to its function, where these could explain mechanisms for its action in uterus during this period.

    METHODS: Female rats, once rendered hypothyroid via oral administration of methimazole (0.03% in drinking water) for twenty-one days were mated with fertile euthyroid male rats at 1:1 ratio. Pregnancy was confirmed by the presence of vaginal plug and this was designated as day-1. Thyroxine (20, 40 and 80 μg/kg/day) was then subcutaneously administered to pregnant, hypothyroid female rats for three days. A day after last injection (day four pregnancy), female rats were sacrificed and expression of thyroid hormone receptors (TR-α and β), retinoid X receptor (RXR) and extracellular signal-regulated kinase (ERK1/2) in uterus were quantified by Western blotting while their distribution in endometrium was visualized by immunofluorescence.

    RESULTS: Expression of TRα-1, TRβ-1 and ERK1/2 proteins in uterus increased with increasing doses of thyroxine however no changes in RXR expression was observed. These proteins were found in the stroma with their distribution levels were relatively higher following thyroxine treatment.

    CONCLUSIONS: Increased expression of TRα-1, TRβ-1 and ERK1/2 at day 4 pregnancy in thyroxine-treated hypothyroid pregnant rats indicate the importance of thyroxine in up-regulating expression of these proteins that could help mediate the uterine changes prior to embryo implantation.

    Matched MeSH terms: MAP Kinase Signaling System/drug effects
  11. Salleh N, Sayem ASM, Giribabu N, Khaing SL
    Cell Biol Int, 2019 May;43(5):486-494.
    PMID: 30761678 DOI: 10.1002/cbin.11114
    Hypothyroidism has been linked to infertility, but the mechanisms underlying infertility-related hypothyroidism have yet to be fully elucidated. Therefore, in this study, effects of hypothyroidism on expression of the proteins related to thyroid hormone function in the uterus, which were thought to play a role implantation, including thyroid hormone receptor (TR), thyroid stimulating hormone receptor (TSHR), retinoic acid receptor (RAR) and extracellular kinase (ERK) were identified. Pregnant female rats were rendered hypothyroid by giving methimazole (MMI), orally. Following hypothyroid induction, rats were grouped into control (non-treated) and received subcutaneous thyroxine at 20, 40, and 80 μg/kg/day for five consecutive days. At Day 6, which is the day of implantation (GD 6), rats were sacrificed and the number of embryo implantation site in the uterus was calculated. Then, uterine horns were harvested and expression of the above proteins and their mRNAs were identified by Western blotting and real-time PCR, respectively. In non-treated hypothyroid pregnant rats, the number of embryo implantation sites decreased as compared to euthyroid and hypothyroid rats receiving thyroxine treatment. Similarly, expression of TRα-1, TRβ-1, TSHR, ERK1/2 and RAR proteins and mRNA in the uterus of non-treated hypothyroid rats also decreased (P 
    Matched MeSH terms: MAP Kinase Signaling System/drug effects
  12. Phang CW, Karsani SA, Sethi G, Abd Malek SN
    PLoS One, 2016;11(2):e0148775.
    PMID: 26859847 DOI: 10.1371/journal.pone.0148775
    Flavokawain C (FKC) is a naturally occurring chalcone which can be found in Kava (Piper methysticum Forst) root. The present study evaluated the effect of FKC on the growth of various human cancer cell lines and the underlying associated mechanisms. FKC showed higher cytotoxic activity against HCT 116 cells in a time- and dose-dependent manner in comparison to other cell lines (MCF-7, HT-29, A549 and CaSki), with minimal toxicity on normal human colon cells. The apoptosis-inducing capability of FKC on HCT 116 cells was evidenced by cell shrinkage, chromatin condensation, DNA fragmentation and increased phosphatidylserine externalization. FKC was found to disrupt mitochondrial membrane potential, resulting in the release of Smac/DIABLO, AIF and cytochrome c into the cytoplasm. Our results also revealed that FKC induced intrinsic and extrinsic apoptosis via upregulation of the levels of pro-apoptotic proteins (Bak) and death receptors (DR5), while downregulation of the levels of anti-apoptotic proteins (XIAP, cIAP-1, c-FlipL, Bcl-xL and survivin), resulting in the activation of caspase-3, -8 and -9 and cleavage of poly(ADP-ribose) polymerase (PARP). FKC was also found to cause endoplasmic reticulum (ER) stress, as suggested by the elevation of GADD153 protein after FKC treatment. After the cells were exposed to FKC (60μM) over 18hrs, there was a substantial increase in the phosphorylation of ERK 1/2. The expression of phosphorylated Akt was also reduced. FKC also caused cell cycle arrest in the S phase in HCT 116 cells in a time- and dose-dependent manner and with accumulation of cells in the sub-G1 phase. This was accompanied by the downregulation of cyclin-dependent kinases (CDK2 and CDK4), consistent with the upregulation of CDK inhibitors (p21Cip1 and p27Kip1), and hypophosphorylation of Rb.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects
  13. Phan CW, Lee GS, Hong SL, Wong YT, Brkljača R, Urban S, et al.
    Food Funct, 2014 Dec;5(12):3160-9.
    PMID: 25288148 DOI: 10.1039/c4fo00452c
    Hericium erinaceus (Bull.: Fr.) Pers. is an edible and medicinal mushroom used traditionally to improve memory. In this study, we investigated the neuritogenic effects of hericenones isolated from H. erinaceus and the mechanisms of action involved. H. erinaceus was cultivated and the secondary metabolites were elucidated by high performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC-MS), and nuclear magnetic resonance (NMR). The secondary metabolites were tested for neurite outgrowth activity (if any). Rat pheochromocytoma (PC12) cells were employed and the nerve growth factor (NGF) level was also determined. The signaling pathways involved in the mushroom-induced neuritogenesis were investigated using several pharmacological inhibitors. Hericenones B-E (1-4), erinacerin A (5) and isohericerin (6) were isolated from the basidiocarps of H. erinaceus. The hericenones did not promote neurite outgrowth but when induced with a low concentration of NGF (5 ng mL(-1)), the neuritogenic activity was comparable to that of the positive control (50 ng mL(-1) of NGF). Hericenone E was able to stimulate NGF secretion which was two-fold higher than that of the positive control. The neuritogenesis process was partially blocked by the tyrosine kinase receptor (Trk) inhibitor, K252a, suggesting that the neuritogenic effect was not solely due to NGF. Hericenone E also increased the phosphorylation of extracellular-signal regulated kinases (ERKs) and protein kinase B (Akt). Taken together, this study suggests that hericenone E potentiated NGF-induced neuritogenesis in PC12 cells via the MEK/ERK and PI3K/Akt pathways.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects*
  14. Rajajendram R, Tham CL, Akhtar MN, Sulaiman MR, Israf DA
    Mediators Inflamm, 2015;2015:176926.
    PMID: 26300589 DOI: 10.1155/2015/176926
    Asthma is associated with increased pulmonary inflammation and airway hyperresponsiveness. The interaction between airway epithelium and inflammatory mediators plays a key role in the pathogenesis of asthma. In vitro studies evaluated the inhibitory effects of 3-(2,5-dimethoxyphenyl)-1-(5-methylfuran-2-yl)prop-2-en-1-one (DMPF-1), a synthetic chalcone analogue, upon inflammation in the A549 lung epithelial cell line. DMPF-1 selectively inhibited TNF-α-stimulated CC chemokine secretion (RANTES, eotaxin-1, and MCP-1) without any effect upon CXC chemokine (GRO-α and IL-8) secretion. Western blot analysis further demonstrated that the inhibitory activity resulted from disruption of p65NF-κB nuclear translocation without any effects on the mitogen-activated protein kinase (MAPK) pathway. Treatment of ovalbumin-sensitized and ovalbumin-challenged BALB/c mice with DMPF-1 (0.2-100 mg/kg) demonstrated significant reduction in the secretion and gene expression of CC chemokines (RANTES, eotaxin-1, and MCP-1) and Th2 cytokines (IL-4, IL-5, and IL-13). Furthermore, DMPF-1 treatment inhibited eosinophilia, goblet cell hyperplasia, peripheral blood total IgE, and airway hyperresponsiveness in ovalbumin-sensitized and ovalbumin-challenged mice. In conclusion, these findings demonstrate the potential of DMPF-1, a nonsteroidal compound, as an antiasthmatic agent for further pharmacological evaluation.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects
  15. Seow SL, Eik LF, Naidu M, David P, Wong KH, Sabaratnam V
    Sci Rep, 2015 Nov 06;5:16349.
    PMID: 26542212 DOI: 10.1038/srep16349
    The traditional application of the sclerotium of Lignosus rhinocerotis (tiger's milk mushroom) by the indigenous folks as tonic and remedy to treat a variety of ailments has been documented in Malaysia. Indigenous communities claimed to have consumed the decoction to boost their alertness during hunting. Mental alertness is believed to be related to neuronal health and neuroactivity. In the present study, the cell viability and neuritogenic effects of L. rhinocerotis sclerotium hot aqueous and ethanolic extracts, and crude polysaccharides on rat pheochromocytoma (PC-12) cells were studied. Interestingly, the hot aqueous extract exhibited neuritogenic activity comparable to NGF in PC-12 cells. However, the extracts and crude polysaccharides stimulated neuritogenesis without stimulating the production of NGF in PC-12 cells. The involvements of the TrkA receptor and MEK/ERK1/2 pathway in hot aqueous extract-stimulated neuritogenesis were examined by Trk (K252a) and MEK/ERK1/2 (U0126 and PD98059) inhibitors. There was no significant difference in protein expression in NGF- and hot aqueous extract-treated cells for both total and phosphorylated p44/42 MAPK. The neuritogenic activity in PC-12 cells stimulated by hot aqueous and ethanolic extracts, and crude polysaccharides of L. rhinocerotis sclerotium mimicking NGF activity via the MEK/ERK1/2 signaling pathway is reported for the first time.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects*
  16. Gautam V, Nimmanpipug P, Zain SM, Rahman NA, Lee VS
    Molecules, 2021 Jul 27;26(15).
    PMID: 34361694 DOI: 10.3390/molecules26154540
    Extracellular signal-regulated kinases 1 and 2 (ERK1/2) play key roles in promoting cell survival and proliferation through the phosphorylation of various substrates. Remarkable antitumour activity is found in many inhibitors that act upstream of the ERK pathway. However, drug-resistant tumour cells invariably emerge after their use due to the reactivation of ERK1/2 signalling. ERK1/2 inhibitors have shown clinical efficacy as a therapeutic strategy for the treatment of tumours with mitogen-activated protein kinase (MAPK) upstream target mutations. These inhibitors may be used as a possible strategy to overcome acquired resistance to MAPK inhibitors. Here, we report a class of repeat proteins-designed ankyrin repeat protein (DARPin) macromolecules targeting ERK2 as inhibitors. The structural basis of ERK2-DARPin interactions based on molecular dynamics (MD) simulations was studied. The information was then used to predict stabilizing mutations employing a web-based algorithm, MAESTRO. To evaluate whether these design strategies were successfully deployed, we performed all-atom, explicit-solvent molecular dynamics (MD) simulations. Two mutations, Ala → Asp and Ser → Leu, were found to perform better than the original sequence (DARPin E40) based on the associated energy and key residues involved in protein-protein interaction. MD simulations and analysis of the data obtained on these mutations supported our predictions.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects*
  17. Ali F, Ismail A, Kersten S
    Mol Nutr Food Res, 2014 Jan;58(1):33-48.
    PMID: 24259381 DOI: 10.1002/mnfr.201300277
    Obesity and related metabolic diseases (e.g., type 2 diabetes, cardiovascular diseases, and hypertension) are the most prevailing nutrition-related issues in the world. An emerging feature of obesity is their relationship with chronic inflammation that begins in white adipose tissue and eventually becomes systemic. One potential dietary strategy to reduce glucose intolerance and inflammation is consumption of polyphenol-rich cocoa-like cocoa or their by-products. In vitro as well as in vivo data indicate that cocoa polyphenols (CPs) may exhibit antioxidant and anti-inflammatory properties. Polyphenols commonly found in cocoa have been reported to regulate lipid metabolism via inducing metabolic gene expression or activating transcription factors that regulate the expression of numerous genes, many of which play an important role in energy metabolism. Currently, several molecular targets (e.g., nuclear factor Kappa B, activated protein-1, peroxisome proliferator-activated receptors, liver X receptors, and adiponectin gene) have been identified, which may explain potential beneficial obesity-associated diseases effects of CPs. Further studies have been performed regarding the protective effects of CPs against metabolic diseases by suppressing transcription factors that antagonize lipid accumulation. Thus, polyphenols-rich cocoa products may diminish obesity-mediated metabolic diseases by multiple mechanisms, thereby attenuating chronic inflammation.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects
  18. Harikrishnan H, Jantan I, Haque MA, Kumolosasi E
    Phytother Res, 2018 Dec;32(12):2510-2519.
    PMID: 30238535 DOI: 10.1002/ptr.6190
    Phyllanthin, a lignan from Phyllanthus species, has been reported to possess potent immunosuppressive properties on immune cells and on adaptive and innate immune responses in animal models. Herein, we investigated the inhibitory effects of phyllanthin isolated from Phyllanthus amarus on nuclear factor-kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and PI3K-Akt signal transducing pathways in LPS-activated U937 cells. The lipopolysaccharide-stimulated excess production of prostaglandin was significantly suppressed by phyllanthin via the mechanisms linked to the modulatory effects of cyclooxygenase 2 protein and gene expression. Phyllanthin also significantly inhibited the release and mRNA expression of proinflammatory cytokines (interleukin-1 beta and tumor necrosis factor-alpha). Phyllanthin also significantly downregulated the phosphorylation of IκBα, NF-κB (p65), and IKKα/β and suppressed the activation of JNK, ERK, p38MAPK, and Akt in a concentration-dependent manner. Additionally, phyllanthin downregulated the expression of upstream signaling molecules including MyD88 and toll-like receptor 4 that are essential for the activation of NF-κB, MAPKs, and PI3K-Akt signal transducing pathways. Based on these observations, phyllanthin may exert their suppressive effects on inflammatory process by mediating the release of inflammatory signaling molecules via the NF-κB, MAPKs, and PI3K-Akt signal transducing pathways. Thus, phyllanthin holds a great promise as a potential anti-inflammatory agent to treat various inflammatory diseases.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects
  19. Phan CW, Wong WL, David P, Naidu M, Sabaratnam V
    PMID: 22812497 DOI: 10.1186/1472-6882-12-102
    Drugs dedicated to alleviate neurodegenerative diseases like Parkinson's and Alzheimer's have always been associated with debilitating side effects. Medicinal mushrooms which harness neuropharmacological compounds offer a potential possibility for protection against such diseases. Pleurotus giganteus (formerly known as Panus giganteus) has been consumed by the indigenous people in Peninsular Malaysia for many years. Domestication of this wild mushroom is gaining popularity but to our knowledge, medicinal properties reported for this culinary mushroom are minimal.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects*
  20. Ong MH, Wong HK, Tengku-Muhammad TS, Choo QC, Chew CH
    Mol Biol Rep, 2019 Jun;46(3):2631-2641.
    PMID: 30989556 DOI: 10.1007/s11033-019-04661-6
    The prevalence of atherosclerosis has increased significantly in the recent years due to sedentary lifestyle and high-fat diet. However, the association between saturated fat intake and the increased risk for atherosclerotic cardiovascular diseases remains heavily debated. Lauric acid belongs to the saturated fatty acid group and its unique medium chain fatty acid properties are proven to be beneficial to humans in many ways. Thus, the aim of this project is to investigate the effect of lauric acid on the expression of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) genes-ADAMTS-1, ADAMTS-4, and ADAMTS-5-in macrophages. These genes encode for proteases that participate in the extracellular matrix remodeling and they play important roles in the vulnerability of atherosclerotic plaque. Here, we show that the treatment of 20 µM of lauric acid successfully reduced both transcriptional and translational expressions of these genes in THP-1 differentiated macrophages after 24-h incubation. Further cell signaling experiments using a panel of kinase inhibitors and phosphorylated antibodies proved that lauric acid down-regulated ADAMTS-1 by reducing the activation of PI3K and JNK at Tyr458 and Tyr185, respectively. Finally, JNK1 siRNA knockdown assay confirmed that ADAMTS-1 was regulated through JNK pathway, and lauric acid interfered with this pathway to down-regulate ADAMTS-1 expression. Although preliminary, this present study indicates that lauric acid has the potential to stabilize atherosclerotic plaque and may prevent thrombosis by interfering with the ADAMTS-1 expression through PI3K/JNK pathways.
    Matched MeSH terms: MAP Kinase Signaling System/drug effects*
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