Displaying publications 41 - 60 of 85 in total

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  1. Abu Bakar MH, Shariff KA, Tan JS, Lee LK
    Eur J Pharmacol, 2020 Sep 15;883:173371.
    PMID: 32712089 DOI: 10.1016/j.ejphar.2020.173371
    Accumulating evidence indicates that adipose tissue inflammation and mitochondrial dysfunction in skeletal muscle are inextricably linked to obesity and insulin resistance. Celastrol, a bioactive compound derived from the root of Tripterygium wilfordii exhibits a number of attributive properties to attenuate metabolic dysfunction in various cellular and animal disease models. However, the underlying therapeutic mechanisms of celastrol in the obesogenic environment in vivo remain elusive. Therefore, the current study investigated the metabolic effects of celastrol on insulin sensitivity, inflammatory response in adipose tissue and mitochondrial functions in skeletal muscle of the high fat diet (HFD)-induced obese rats. Our study revealed that celastrol supplementation at 3 mg/kg/day for 8 weeks significantly reduced the final body weight and enhanced insulin sensitivity of the HFD-fed rats. Celastrol noticeably improved insulin-stimulated glucose uptake activity and increased expression of plasma membrane GLUT4 protein in skeletal muscle. Moreover, celastrol-treated HFD-fed rats showed attenuated inflammatory responses via decreased NF-κB activity and diminished mRNA expression responsible for classically activated macrophage (M1) polarization in adipose tissues. Significant improvement of muscle mitochondrial functions and enhanced antioxidant defense machinery via restoration of mitochondrial complexes I + III linked activity were effectively exhibited by celastrol treatment. Mechanistically, celastrol stimulated mitochondrial biogenesis attributed by upregulation of the adenosine monophosphate-activated protein kinase (AMPK) and sirtuin 1 (SIRT1) signaling pathways. Together, these results further demonstrate heretofore the conceivable therapeutic mechanisms of celastrol in vivo against HFD-induced obesity mediated through attenuation of inflammatory response in adipose tissue and enhanced mitochondrial functions in skeletal muscle.
    Matched MeSH terms: AMP-Activated Protein Kinases/metabolism*
  2. Stegger M, Wirth T, Andersen PS, Skov RL, De Grassi A, Simões PM, et al.
    mBio, 2014 Aug 26;5(5):e01044-14.
    PMID: 25161186 DOI: 10.1128/mBio.01044-14
    Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) was recognized in Europe and worldwide in the late 1990s. Within a decade, several genetically and geographically distinct CA-MRSA lineages carrying the small SCCmec type IV and V genetic elements and the Panton-Valentine leukocidin (PVL) emerged around the world. In Europe, the predominant CA-MRSA strain belongs to clonal complex 80 (CC80) and is resistant to kanamycin/amikacin and fusidic acid. CC80 was first reported in 1993 but was relatively rare until the late 1990s. It has since been identified throughout North Africa, the Middle East, and Europe, with recent sporadic reports in sub-Saharan Africa. While strongly associated with skin and soft tissue infections, it is rarely found among asymptomatic carriers. Methicillin-sensitive S. aureus (MSSA) CC80 strains are extremely rare except in sub-Saharan Africa. In the current study, we applied whole-genome sequencing to a global collection of both MSSA and MRSA CC80 isolates. Phylogenetic analyses strongly suggest that the European epidemic CA-MRSA lineage is derived from a PVL-positive MSSA ancestor from sub-Saharan Africa. Moreover, the tree topology suggests a single acquisition of both the SCCmec element and a plasmid encoding the fusidic acid resistance determinant. Four canonical SNPs distinguish the derived CA-MRSA lineage and include a nonsynonymous mutation in accessory gene regulator C (agrC). These changes were associated with a star-like expansion into Europe, the Middle East, and North Africa in the early 1990s, including multiple cases of cross-continent imports likely driven by human migrations.

    IMPORTANCE: With increasing levels of CA-MRSA reported from most parts of the Western world, there is a great interest in understanding the origin and factors associated with the emergence of these epidemic lineages. To trace the origin, evolution, and dissemination pattern of the European CA-MRSA clone (CC80), we sequenced a global collection of strains of the S. aureus CC80 lineage. Our study determined that a single descendant of a PVL-positive methicillin-sensitive ancestor circulating in sub-Saharan Africa rose to become the dominant CA-MRSA clone in Europe, the Middle East, and North Africa. In the transition from a methicillin-susceptible lineage to a successful CA-MRSA clone, it simultaneously became resistant to fusidic acid, a widely used antibiotic for skin and soft tissue infections, thus demonstrating the importance of antibiotic selection in the success of this clone. This finding furthermore highlights the significance of horizontal gene acquisitions and underscores the combined importance of these factors for the success of CA-MRSA.

    Matched MeSH terms: Protein Kinases/metabolism
  3. Rullah K, Shamsudin NF, Koeberle A, Tham CL, Fasihi Mohd Aluwi MF, Leong SW, et al.
    Future Med Chem, 2024 Jan;16(1):75-99.
    PMID: 38205612 DOI: 10.4155/fmc-2023-0174
    Targeting lipopolysaccharide (LPS)/toll-like receptor 4 signaling in mononuclear phagocytes has been explored for the treatment of inflammation and inflammation-related disorders. However, only a few key targets have been translated into clinical applications. Flavonoids, a class of ubiquitous plant secondary metabolites, possess a privileged scaffold which serves as a valuable template for designing pharmacologically active compounds directed against diseases with inflammatory components. This perspective provides a general overview of the diversity of flavonoids and their multifaceted mechanisms that interfere with LPS-induced signaling in monocytes and macrophages. Focus is placed on flavonoids targeting MD-2, IκB kinases, c-Jun N-terminal kinases, extracellular signal-regulated kinase, p38 MAPK and PI3K/Akt or modulating LPS-related gene expression.
    Matched MeSH terms: p38 Mitogen-Activated Protein Kinases/metabolism
  4. Harikrishnan H, Jantan I, Haque MA, Kumolosasi E
    BMC Complement Altern Med, 2018 Jul 25;18(1):224.
    PMID: 30045725 DOI: 10.1186/s12906-018-2289-3
    BACKGROUND: Phyllanthus amarus has been used widely in various traditional medicines to treat swelling, sores, jaundice, inflammatory diseases, kidney disorders, diabetes and viral hepatitis, while its pharmacological and biochemical mechanisms underlying its anti-inflammatory properties have not been well investigated. The present study was carried out to investigate the effects of 80% ethanolic extract of P. amarus on pro-inflammatory mediators release in nuclear factor-kappa B (NF-кB), mitogen activated protein kinase (MAPK) and phosphatidylinositol 3-kinase/Akt (PI3K-Akt) signaling activation in lipopolysaccharide (LPS)-induced U937 human macrophages.

    METHODS: The release of prostaglandin E2 (PGE2) and pro-inflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin (IL)-1β in a culture supernatant was determined by ELISA. Determination of cyclooxygenase-2 (COX-2) protein and the activation of MAPKs molecules (JNK, ERK and p38 MAPK), NF-κB and Akt in LPS-induced U937 human macrophages were investigated by immunoblot technique. The relative gene expression levels of COX-2 and pro-inflammatory cytokines were measured by using qRT-PCR. The major metabolites of P. amarus were qualitatively and quantitatively analyzed in the extract by using validated reversed-phase high performance liquid chromatography (HPLC) methods.

    RESULTS: P. amarus extract significantly inhibited the production of pro-inflammatory mediators (TNF-α, IL-1β, PGE2) and COX-2 protein expression in LPS-induced U937 human macrophages. P. amarus-pretreatment also significantly downregulated the increased mRNA transcription of pro-inflammatory markers (TNF-α, IL-1β, and COX-2) in respective LPS-induced U937 macrophages. It downregulated the phosphorylation of NF-κB (p65), IκBα, and IKKα/β and restored the degradation of IκBα, and attenuated the expression of Akt, JNK, ERK, and p38 MAPKs phosphorylation in a dose-dependent manner. P. amarus extract also downregulated the expression of upstream signaling molecules, TLR4 and MyD88, which play major role in activation of NF-κB, MAPK and PI3K-Akt signaling pathways. The quantitative amounts of lignans, phyllanthin, hypophyllahtin and niranthin, and polyphenols, gallic acid, geraniin, corilagin, and ellagic acid in the extract were determined by HPLC analysis.

    CONCLUSION: The study revealed that P. amarus targeted the NF-κB, MAPK and PI3K-Akt signaling pathways to exert its anti- inflammatory effects by downregulating the prospective inflammatory signaling mediators.

    Matched MeSH terms: Mitogen-Activated Protein Kinases/metabolism
  5. 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: Mitogen-Activated Protein Kinases/metabolism
  6. Wu Q, Wu W, Fu B, Shi L, Wang X, Kuca K
    Med Res Rev, 2019 11;39(6):2082-2104.
    PMID: 30912203 DOI: 10.1002/med.21574
    c-Jun N-terminal kinase (JNK) is involved in cancer cell apoptosis; however, emerging evidence indicates that this Janus signaling promotes cancer cell survival. JNK acts synergistically with NF-κB, JAK/STAT, and other signaling molecules to exert a survival function. JNK positively regulates autophagy to counteract apoptosis, and its effect on autophagy is related to the development of chemotherapeutic resistance. The prosurvival effect of JNK may involve an immune evasion mechanism mediated by transforming growth factor-β, toll-like receptors, interferon-γ, and autophagy, as well as compensatory JNK-dependent cell proliferation. The present review focuses on recent advances in understanding the prosurvival function of JNK and its role in tumor development and chemoresistance, including a comprehensive analysis of the molecular mechanisms underlying JNK-mediated cancer cell survival. There is a focus on the specific "Yin and Yang" functions of JNK1 and JNK2 in the regulation of cancer cell survival. We highlight recent advances in our knowledge of the roles of JNK in cancer cell survival, which may provide insight into the distinct functions of JNK in cancer and its potential for cancer therapy.
    Matched MeSH terms: JNK Mitogen-Activated Protein Kinases/metabolism*
  7. Siti HN, Jalil J, Asmadi AY, Kamisah Y
    Int J Mol Sci, 2021 May 11;22(10).
    PMID: 34064664 DOI: 10.3390/ijms22105063
    Rutin is a flavonoid with antioxidant property. It has been shown to exert cardioprotection against cardiomyocyte hypertrophy. However, studies regarding its antihypertrophic property are still lacking, whether it demonstrates similar antihypertrophic effect to its metabolite, quercetin. Hence, this study aimed to investigate the effects of both flavonoids on oxidative stress and mitogen-activated protein kinase (MAPK) pathway in H9c2 cardiomyocytes that were exposed to angiotensin II (Ang II) to induce hypertrophy. Cardiomyocytes were exposed to Ang II (600 nM) with or without quercetin (331 μM) or rutin (50 μM) for 24 h. A group given vehicle served as the control. The concentration of the flavonoids was chosen based on the reported effective concentration to reduce cell hypertrophy or cardiac injury in H9c2 cells. Exposure to Ang II increased cell surface area, intracellular superoxide anion level, NADPH oxidase and inducible nitric oxide synthase activities, and reduced cellular superoxide dismutase activity and nitrite level, which were similarly reversed by both rutin and quercetin. Rutin had no significant effects on phosphorylated proteins of extracellular signal-related kinases (ERK1/2) and p38 but downregulated phosphorylated c-Jun N-terminal kinases (JNK1/2), which were induced by Ang II. Quercetin, on the other hand, had significantly downregulated the phosphorylated proteins of ERK1/2, p38, and JNK1/2. The quercetin inhibitory effect on JNK1/2 was stronger than the rutin. In conclusion, both flavonoids afford similar protective effects against Ang II-induced cardiomyocyte hypertrophy, but they differently modulate MAPK pathway.
    Matched MeSH terms: Mitogen-Activated Protein Kinases/metabolism*
  8. Yeap SK, Abu N, Akthar N, Ho WY, Ky H, Tan SW, et al.
    Integr Cancer Ther, 2017 09;16(3):373-384.
    PMID: 27458249 DOI: 10.1177/1534735416660383
    Flavokawain B (FKB) is known to possess promising anticancer abilities. This is demonstrated in various cancer cell lines including HeLa cells. Cervical cancer is among the most widely diagnosed cancer among women today. Though FKB has been shown to be effective in treating cancer cells, the exact molecular mechanism is still unknown. This study is aimed at understanding the effects of FKB on HeLa cells using a microarray-based mRNA expression profiling and proteome profiling of stress-related proteins. The results of this study suggest that FKB induced cell death through p21-mediated cell cycle arrest and activation of p38. However, concurrent activation of antioxidant-related pathways and iron sequestration pathway followed by activation of ER-resident stress proteins clearly indicate that FKB failed to induce apoptosis in HeLa cells via oxidative stress. This effect implies that the protection of HeLa cells by FKB from H2O2-induced cell death is via neutralization of reactive oxygen species.
    Matched MeSH terms: p38 Mitogen-Activated Protein Kinases/metabolism
  9. Tham CL, Lam KW, Rajajendram R, Cheah YK, Sulaiman MR, Lajis NH, et al.
    Eur J Pharmacol, 2011 Feb 10;652(1-3):136-44.
    PMID: 21114991 DOI: 10.1016/j.ejphar.2010.10.092
    We previously showed that 2,6-bis-(4-hydroxyl-3-methoxybenzylidine)cyclohexanone (BHMC), suppressed the synthesis of various proinflammatory mediators. In this study we explain the mechanism of action of BHMC in lipopolysaccharide (LPS)-induced U937 monocytes and further show that BHMC prevents lethality of CLP-induced sepsis. BHMC showed dose-dependent inhibitory effects on p38, JNK and ERK 1/2 activity as determined by inhibition of phosphorylation of downstream transcription factors ATF-2, c-Jun and Elk-1 respectively. Inhibition of these transcription factors subsequently caused total abolishment of AP-1-DNA binding. BHMC inhibited p65 NF-κB nuclear translocation and DNA binding of p65 NF-κB only at the highest concentration used (12.5μM) but failed to alter phosphorylation of JNK, ERK1/2 and STAT-1. Since the inhibition of p38 activity was more pronounced we evaluated the possibility that BHMC may bind to p38. Molecular docking experiments confirmed that BHMC fits well in the highly conserved hydrophobic pocket of p38 MAP kinase. We also show that BHMC was able to improve survival from lethal sepsis in a murine caecal-ligation and puncture (CLP) model.
    Matched MeSH terms: Mitogen-Activated Protein Kinases/metabolism
  10. Tor YS, Yazan LS, Foo JB, Armania N, Cheah YK, Abdullah R, et al.
    PMID: 24524627 DOI: 10.1186/1472-6882-14-55
    Breast cancer is one of the most dreading types of cancer among women. Herbal medicine has becoming a potential source of treatment for breast cancer. Herbal plant Dillenia suffruticosa (Griff) Martelli under the family Dilleniaceae has been traditionally used to treat cancerous growth. In this study, the anticancer effect of ethyl acetate extract of D. suffruticosa (EADs) was examined on human breast adenocarcinoma cell line MCF-7 and the molecular pathway involved was elucidated.
    Matched MeSH terms: p38 Mitogen-Activated Protein Kinases/metabolism
  11. Wong SK, Chin KY, Ima-Nirwana S
    Phytomedicine, 2020 Jul 15;73:152892.
    PMID: 30902523 DOI: 10.1016/j.phymed.2019.152892
    BACKGROUND: Musculoskeletal disorders are a group of disorders that affect the joints, bones, and muscles, causing long-term disability. Berberine, an isoquinoline alkaloid, has been previously established to exhibit beneficial properties in preventing various diseases, including musculoskeletal disorders.

    PURPOSE: This review article aims to recapitulate the therapeutic potential of berberine and its mechanism of action in treating musculoskeletal disorders.

    METHODS: A wide range of literature illustrating the effects of berberine in ameliorating musculoskeletal disorders was retrieved from online electronic databases (PubMed and Medline) and reviewed.

    RESULTS: Berberine may potentially retard the progression of osteoporosis, osteoarthritis and rheumatoid arthritis. Limited studies reported the effects of berberine in suppressing the proliferation of osteosarcoma cells. These beneficial properties of berberine are mediated in part through its ability to target multiple signaling pathways, including PKA, p38 MAPK, Wnt/β-catenin, AMPK, RANK/RANKL/OPG, PI3K/Akt, NFAT, NF-κB, Hedgehog, and oxidative stress signaling. In addition, berberine exhibited anti-apoptotic, anti-inflammatory, and immunosuppressive properties.

    CONCLUSION: The current evidence indicates that berberine may be effective in preventing musculoskeletal disorders. However, findings from in vitro and in vivo investigations await further validation from human clinical trial.

    Matched MeSH terms: p38 Mitogen-Activated Protein Kinases/metabolism
  12. Choy KW, Mustafa MR, Lau YS, Liu J, Murugan D, Lau CW, et al.
    Biochem Pharmacol, 2016 09 15;116:51-62.
    PMID: 27449753 DOI: 10.1016/j.bcp.2016.07.013
    Endoplasmic reticulum (ER) stress in endothelial cells often leads to endothelial dysfunction which underlies the pathogenesis of cardiovascular diseases. Paeonol, a major phenolic component extracted from Moutan Cortex, possesses various medicinal benefits which have been used extensively in traditional Chinese medicine. The present study investigated the protective mechanism of paeonol against tunicamycin-induced ER stress in isolated mouse aortas and human umbilical vein endothelial cells (HUVECs). Vascular reactivity in aorta was measured using a wire myograph. The effects of paeonol on protein expression of ER stress markers, reactive oxygen species (ROS) production, nitric oxide (NO) bioavailability and peroxisome proliferator-activated receptor δ (PPARδ) activity in the vascular wall were assessed by Western blot, dihydroethidium fluorescence (DHE) or lucigenin enhanced-chemiluminescence, 4-amino-5-methylamino-2',7'-difluorofluorescein (DAF-FM DA) and dual luciferase reporter assay, respectively. Ex vivo treatment with paeonol (0.1μM) for 16h reversed the impaired endothelium-dependent relaxations in C57BJ/6J and PPARδ wild type (WT) mouse aortas following incubation with tunicamycin (0.5μg/mL). Elevated ER stress markers, oxidative stress and reduction of NO bioavailability induced by tunicamycin in HUVECs, C57BJ/6J and PPARδ WT mouse aortas were reversed by paeonol treatment. These beneficial effects of paeonol were diminished in PPARδ knockout (KO) mouse aortas. Paeonol increased the expression of 5' adenosine monophosphate-activated protein kinase (AMPK) and PPARδ expression and activity while restoring the decreased phosphorylation of eNOS. The present study delineates that paeonol protects against tunicamycin-induced vascular endothelial dysfunction by inhibition of ER stress and oxidative stress, thus elevating NO bioavailability via the AMPK/PPARδ signaling pathway.
    Matched MeSH terms: AMP-Activated Protein Kinases/metabolism*
  13. Jeevaratnam K, Salvage SC, Li M, Huang CL
    Ann N Y Acad Sci, 2018 Dec;1433(1):18-28.
    PMID: 29846007 DOI: 10.1111/nyas.13861
    Alterations in cellular levels of the second messenger 3',5'-cyclic adenosine monophosphate ([cAMP]i ) regulate a wide range of physiologically important cellular signaling processes in numerous cell types. Osteoclasts are terminally differentiated, multinucleated cells specialized for bone resorption. Their systemic regulator, calcitonin, triggers morphometrically and pharmacologically distinct retraction (R) and quiescence (Q) effects on cell-spread area and protrusion-retraction motility, respectively, paralleling its inhibition of bone resorption. Q effects were reproduced by cholera toxin-mediated Gs -protein activation known to increase [cAMP]i , unaccompanied by the [Ca2+ ]i changes contrastingly associated with R effects. We explore a hypothesis implicating cAMP signaling involving guanine nucleotide-exchange activation of the small GTPase Ras-proximate-1 (Rap1) by exchange proteins directly activated by cAMP (Epac). Rap1 activates integrin clustering, cell adhesion to bone matrix, associated cytoskeletal modifications and signaling processes, and transmembrane transduction functions. Epac activation enhanced, whereas Epac inhibition or shRNA-mediated knockdown compromised, the appearance of markers for osteoclast differentiation and motility following stimulation by receptor activator of nuclear factor kappa-Β ligand (RANKL). Deficiencies in talin and Rap1 compromised in vivo bone resorption, producing osteopetrotic phenotypes in genetically modified murine models. Translational implications of an Epac-Rap1 signaling hypothesis in relationship to N-bisphosphonate actions on prenylation and membrane localization of small GTPases are discussed.
    Matched MeSH terms: Cyclic AMP-Dependent Protein Kinases/metabolism
  14. Khew CY, Teo CJ, Chan WS, Wong HL, Namasivayam P, Ho CL
    J Plant Physiol, 2015 Jun 15;182:23-32.
    PMID: 26037695 DOI: 10.1016/j.jplph.2015.05.003
    Brassinosteroid Insensitive 1 (BRI1)-Associated Kinase I (BAK1) has been reported to interact with BRI1 for brassinosteroid (BR) perception and signal transduction that regulate plant growth and development. The aim of this study is to investigate the functions of a rice OsBAK1 homologue, designated as OsI-BAK1, which is highly expressed after heading. Silencing of OsI-BAK1 in rice plants produced a high number of undeveloped green and unfilled grains compared to the untransformed plants. Histological analyses demonstrated that embryos were either absent or retarded in their development in these unfilled rice grains of OsI-BAK1 RNAi plants. Down regulation of OsI-BAK1 caused a reduction in cell number and enlargement in leaf bulliform cells. Furthermore, transgenic rice plants overexpressing OsI-BAK1 were demonstrated to have corrugated and twisted leaves probably due to increased cell number that caused abnormal bulliform cell structure which were enlarged and plugged deep into leaf epidermis. The current findings suggest that OsI-BAK1 may play an important role in the developmental processes of rice grain filling and leaf cell including the bulliform cells.
    Matched MeSH terms: Protein Kinases/metabolism
  15. 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: p38 Mitogen-Activated Protein Kinases/metabolism*
  16. Lane SC, Camera DM, Lassiter DG, Areta JL, Bird SR, Yeo WK, et al.
    J Appl Physiol (1985), 2015 Sep 15;119(6):643-55.
    PMID: 26112242 DOI: 10.1152/japplphysiol.00857.2014
    We determined the effects of "periodized nutrition" on skeletal muscle and whole body responses to a bout of prolonged exercise the following morning. Seven cyclists completed two trials receiving isoenergetic diets differing in the timing of ingestion: they consumed either 8 g/kg body mass (BM) of carbohydrate (CHO) before undertaking an evening session of high-intensity training (HIT) and slept without eating (FASTED), or consumed 4 g/kg BM of CHO before HIT, then 4 g/kg BM of CHO before sleeping (FED). The next morning subjects completed 2 h of cycling (120SS) while overnight fasted. Muscle biopsies were taken on day 1 (D1) before and 2 h after HIT and on day 2 (D2) pre-, post-, and 4 h after 120SS. Muscle [glycogen] was higher in FED at all times post-HIT (P < 0.001). The cycling bouts increased PGC1α mRNA and PDK4 mRNA (P < 0.01) in both trials, with PDK4 mRNA being elevated to a greater extent in FASTED (P < 0.05). Resting phosphorylation of AMPK(Thr172), p38MAPK(Thr180/Tyr182), and p-ACC(Ser79) (D2) was greater in FASTED (P < 0.05). Fat oxidation during 120SS was higher in FASTED (P = 0.01), coinciding with increases in ACC(Ser79) and CPT1 as well as mRNA expression of CD36 and FABP3 (P < 0.05). Methylation on the gene promoter for COX4I1 and FABP3 increased 4 h after 120SS in both trials, whereas methylation of the PPARδ promoter increased only in FASTED. We provide evidence for shifts in DNA methylation that correspond with inverse changes in transcription for metabolically adaptive genes, although delaying postexercise feeding failed to augment markers of mitochondrial biogenesis.
    Matched MeSH terms: Protein Kinases/metabolism; p38 Mitogen-Activated Protein Kinases/metabolism; AMP-Activated Protein Kinases/metabolism
  17. Thomas W, Dooley R, Quinn S, Robles MY, Harvey BJ
    Steroids, 2020 03;155:108553.
    PMID: 31836481 DOI: 10.1016/j.steroids.2019.108553
    Protein kinase D2 (PKD2) is a serine/threonine protein kinase which plays an important role in vesicle fission at the trans-Golgi network (TGN) to coordinate subcellular trafficking with gene expression. We found that in the rat kidney, PKD2 is specifically expressed in collecting duct principal cells predominantly at the apical membrane and with lower basal expression in cytosolic compartments. When rats were maintained on a Na+ depleted diet (<0.87 mmol Na+/kg) to increase plasma aldosterone levels, PKD2 became internalized to a cytoplasmic compartment. Treatment of murine M1 cortical collecting duct (M1-CCD) cells with aldosterone (10 nM) promoted PKD2 co-localization with the trans-Golgi network within 30 min. PKD2 underwent autophosphorylation at Ser876 within 10 min of aldosterone treatment and remained phosphorylated (active) for at least 24 h. A stable PKD2 shRNA knock-down (PKD2 KD) M1-CCD cell line was developed to study the role of PKD2 in epithelial Na+ channel (ENaC) trafficking and transepithelial Na+ transport (SCC) in epithelial monolayers grown in Ussing chambers. The PKD2 KD cells developed transepithelial resistance with kinetics equivalent to wild-type cells, however the transepithelial voltage and Na+ current were significantly elevated in PKD2 knock-down CCD epithelia. The higher basal SCC was due to increased ENaC activity. Aldosterone treatment for 24 h resulted in a decline in ENaC activity in the PKD2 KD cells as opposed to the increase observed in the wild-type cells. The paradoxical inhibition of SCC by aldosterone in PKD2 KD epithelium was attributed to a reduction in ENaC current and lower membrane abundance of ENaC, demonstrating that PKD2 plays a critical tonic role in ENaC trafficking and channel subunit stability. The rapid activation of PKD2 by aldosterone is synergistic with the transcriptional activity of MR and contributes to increased ENaC activity.
    Matched MeSH terms: Protein Kinases/metabolism*
  18. Haque MA, Jantan I, Harikrishnan H
    Int Immunopharmacol, 2018 Feb;55:312-322.
    PMID: 29310107 DOI: 10.1016/j.intimp.2018.01.001
    Zerumbone (ZER), isolated mainly from the Zingiber zerumbet (Z. zerumbet) rhizomes was found to be effective against numerous inflammatory and immune disorders, however, the molecular and biochemical mechanisms underlying its anti-inflammatory and immunosuppressive properties have not been well studied. This study was carried out to examine the profound effects of ZER on inflammatory mediated MyD88-dependent NF-κB/MAPK/PI3K-Akt signaling pathways in LPS-stimulated U937 human macrophages. ZER significantly suppressed the up-regulation pro-inflammatory mediators, TNF-α, IL-1β, PGE2, and COX-2 protein in LPS-induced human macrophages. Moreover, ZER significantly downregulated the phosphorylation of NF-κB (p65), IκBα, and IKKα/β as well as restored the degradation of IκBα. ZER correspondingly showed remarkable attenuation of the expression of Akt, JNK, ERK, and p38 MAPKs phosphorylation in a concentration-dependent manner. ZER also diminished the expression of upstream signaling molecules TLR4 and MyD88, which are prerequisite for the NF-κB, MAPK and PI3K-Akt activation. Additionally, quantification of relative gene expression of TNF-α, IL-1β, and COX-2 indicated that, at a higher dose (50μM), ZER significantly downregulated the elevated mRNA transcription levels of the stated pro-inflammatory markers in LPS-stimulated U937 macrophages. The strong suppressive effects of ZER on the activation of inflammatory markers in the macrophages via MyD88-dependent NF-κB/MAPK/PI3K-Akt signaling pathways suggest that ZER can be a preventive and potent therapeutic candidate for the management of various inflammatory-mediated immune disorders.
    Matched MeSH terms: Mitogen-Activated Protein Kinases/metabolism
  19. Dutta S, Shah RB, Singhal S, Dutta SB, Bansal S, Sinha S, et al.
    Drug Des Devel Ther, 2023;17:1907-1932.
    PMID: 37397787 DOI: 10.2147/DDDT.S409373
    Metformin has been designated as one of the most crucial first-line therapeutic agents in the management of type 2 diabetes mellitus. Primarily being an antihyperglycemic agent, metformin also has a plethora of pleiotropic effects on various systems and processes. It acts majorly by activating AMPK (Adenosine Monophosphate-Activated Protein Kinase) in the cells and reducing glucose output from the liver. It also decreases advanced glycation end products and reactive oxygen species production in the endothelium apart from regulating the glucose and lipid metabolism in the cardiomyocytes, hence minimizing the cardiovascular risks. Its anticancer, antiproliferative and apoptosis-inducing effects on malignant cells might prove instrumental in the malignancy of organs like the breast, kidney, brain, ovary, lung, and endometrium. Preclinical studies have also shown some evidence of metformin's neuroprotective role in Parkinson's disease, Alzheimer's disease, multiple sclerosis and Huntington's disease. Metformin exerts its pleiotropic effects through varied pathways of intracellular signalling and exact mechanism in the majority of them remains yet to be clearly defined. This article has extensively reviewed the therapeutic benefits of metformin and the details of its mechanism for a molecule of boon in various conditions like diabetes, prediabetes, obesity, polycystic ovarian disease, metabolic derangement in HIV, various cancers and aging.
    Matched MeSH terms: AMP-Activated Protein Kinases/metabolism
  20. Motaghed M, Al-Hassan FM, Hamid SS
    Int J Mol Med, 2014 Jan;33(1):8-16.
    PMID: 24270600 DOI: 10.3892/ijmm.2013.1563
    New drugs are continuously being developed for the treatment of patients with estrogen receptor-positive breast cancer. Thymoquinone is one of the drugs that exhibits anticancer characteristics based on in vivo and in vitro models. This study further investigates the effects of thymoquinone on human gene expression using cDNA microarray technology. The quantification of RNA samples was carried out using an Agilent 2100 Bioanalyser to determine the RNA integrity number (RIN). The Agilent Low Input Quick Amplification Labelling kit was used to generate cRNA in two-color microarray analysis. Samples with RIN >9.0 were used in this study. The universal human reference RNA was used as the common reference. The samples were labelled with cyanine-3 (cye-3) CTP dye and the universal human reference was labelled with cyanine-5 (cye-5) CTP dye. cRNA was purified with the RNeasy Plus Mini kit and quantified using a NanoDrop 2000c spectrophotometer. The arrays were scanned data analysed using Feature Extraction and GeneSpring software. Two-step qRT-PCR was selected to determine the relative gene expression using the High Capacity RNA-to-cDNA kit. The results from Gene Ontology (GO) analysis, indicated that 8 GO terms were related to biological processes (84%) and molecular functions (16%). A total of 577 entities showed >2-fold change in expression. Of these entities, 45.2% showed an upregulation and 54.7% showed a downregulation in expression. The interpretation of single experiment analysis (SEA) revealed that the cytochrome P450, family 1, subfamily A, polypeptide 1 (CYP1A1) and UDP glucuronosyltransferase 1 family, polypeptide A8 (UGT1A8) genes in the estrogen metabolic pathway were downregulated significantly by 43- and 11‑fold, respectively. The solute carrier family 7 (anionic amino acid transporter light chain, xc-system), member 11 (SLC7A11) gene in the interferon pathway, reported to be involved in the development of chemoresistance, was downregulated by 15‑fold. The interferon-induced protein with tetratricopeptide repeats (IFIT)1, IFIT2, IFIT3, interferon, α-inducible protein (IFI)6 (also known as G1P3), interferon regulatory factor 9 (IRF9, ISGF3), 2'-5'-oligoadenylate synthetase 1, 40/46 kDa (OAS1) and signal transducer and activator of transcription 1 (STAT1) genes all showed changes in expression following treatment with thymoquinone. The caspase 10, apoptosis-related cysteine peptidase (CASP10) gene was activated and the protein tyrosine phosphatase, receptor type, R (PTPRR) and myocyte enhancer factor 2C (MEF2C) genes were upregulated in the classical MAPK and p38 MAPK pathways. These findings indicate that thymquinone targets specific genes in the estrogen metabolic and interferon pathways.
    Matched MeSH terms: p38 Mitogen-Activated Protein Kinases/metabolism
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