Displaying publications 1 - 20 of 28 in total

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  1. The role of mTOR signalling pathway in hypoxia-induced cognitive impairment
    Abdo Qaid EY, Zulkipli NN, Zakaria R, Ahmad AH, Othman Z, Muthuraju S, et al.
    Int J Neurosci, 2021 May;131(5):482-488.
    PMID: 32202188 DOI: 10.1080/00207454.2020.1746308
    Hypoxia has been associated with cognitive impairment. Many studies have investigated the role of mTOR signalling pathway in cognitive functions but its role in hypoxia-induced cognitive impairment remains controversial. This review aimed to elucidate the role of mTOR in the mechanisms of cognitive impairment that may pave the way towards the mechanistic understanding and therapeutic intervention of hypoxia-induced cognitive impairment. mTORC1 is normally regulated during mild or acute hypoxic exposure giving rise to neuroprotection, whereas it is overactivated during severe or chronic hypoxia giving rise to neuronal cells death. Thus, it is worth exploring the possibility of maintaining normal mTORC1 activity and thereby preventing cognitive impairment during severe or chronic hypoxia.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism*
  2. Antioxidant Modulation of mTOR and Sirtuin Pathways in Age-Related Neurodegenerative Diseases
    Abdullah A, Mohd Murshid N, Makpol S
    Mol Neurobiol, 2020 Dec;57(12):5193-5207.
    PMID: 32865663 DOI: 10.1007/s12035-020-02083-1
    In the human body, cell division and metabolism are expected to transpire uneventfully for approximately 25 years. Then, secondary metabolism and cell damage products accumulate, and ageing phenotypes are acquired, causing the progression of disease. Among these age-related diseases, neurodegenerative diseases have attracted considerable attention because of their irreversibility, the absence of effective treatment and their relationship with social and economic pressures. Mechanistic (formerly mammalian) target of rapamycin (mTOR), sirtuin (SIRT) and insulin/insulin growth factor 1 (IGF1) signalling pathways are among the most important pathways in ageing-associated conditions, such as neurodegeneration. These longevity-related pathways are associated with a diversity of various processes, including metabolism, cognition, stress reaction and brain plasticity. In this review, we discuss the roles of sirtuin and mTOR in ageing and neurodegeneration, with an emphasis on their regulation of autophagy, apoptosis and mitochondrial energy metabolism. The intervention of neurodegeneration using potential antioxidants, including vitamins, phytochemicals, resveratrol, herbals, curcumin, coenzyme Q10 and minerals, specifically aimed at retaining mitochondrial function in the treatment of Alzheimer's disease, Parkinson's disease and Huntington's disease is highlighted.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism*
  3. PI3K/Akt/mTOR Pathways Inhibitors with Potential Prospects in Non-Small-Cell Lung Cancer
    Alharbi KS, Shaikh MAJ, Almalki WH, Kazmi I, Al-Abbasi FA, Alzarea SI, et al.
    J Environ Pathol Toxicol Oncol, 2022;41(4):85-102.
    PMID: 36374963 DOI: 10.1615/JEnvironPatholToxicolOncol.2022042281
    Lung cancer is the leading cause of cancer-related mortality across the globe. The most prevalent pathological form of lung cancer is non-small-cell lung cancer (NSCLC). Elevated stimulation of the PI3K/Akt/mTOR pathway causes a slew of cancer-related symptoms, making it a promising target for new anticancer drugs. The PI3K/Akt/mTOR path is involved extensively in carcinogenesis and disease advancement in NSCLC. Several new inhibitors targeting this pathway have been discovered in preclinical investigations and clinical trials. The etiology and epidemiology of NSCLC and biology of the PI3K/Akt/mTOR cascade and its role in NSCLC pathogenesis have all been discussed in this article. In this article, we've reviewed PI3K/Akt/mTOR cascade inhibitors that have been proven in vitro and in preclinical trials to be effective in NSCLC. Drugs targeting the PI3K/Akt/mTOR path in the treatment of NSCLC were also addressed. A better knowledge of the underlying molecular biology, including epigenetic changes, is also critical to detecting relevant biomarkers and guiding combination methods. Additionally, improved clinical trial designs will increase the capacity to test novel drugs and combinations for accounting for genomic variation and eventually improve patient outcomes.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism
  4. Sodium alginate encapsulated iron oxide decorated with thymoquinone nanocomposite induces apoptosis in human breast cancer cells via PI3K-Akt-mTOR pathway
    Alzahrani B, Elderdery AY, Alsrhani A, Alzerwi NAN, Althobiti MM, Elkhalifa AME, et al.
    Int J Biol Macromol, 2023 Jul 31;244:125054.
    PMID: 37245766 DOI: 10.1016/j.ijbiomac.2023.125054
    The present study investigated the cytotoxicity and proapoptotic properties of iron oxide-sodium-alginate-thymoquinone nanocomposites against breast cancer MDA-MB-231 cells in vitro and in silico. This study used chemical synthesis to formulate the nanocomposite. Electron microscopies such as scanning (SEM) and transmission (TEM), Fourier transform infrared (FT-IR), Ultraviolet-Visible, Photoluminescence spectroscopy, selected area (electron) diffraction (SAED), energy dispersive X-ray analysis (EDX), and X-ray diffraction studies (XRD) were used to characterize the synthesized ISAT-NCs and the average size of them was found to be 55 nm. To evaluate the cytotoxic, antiproliferative, and apoptotic potentials of ISAT-NCs on MDA-MB-231 cells, MTT assays, FACS-based cell cycle studies, annexin-V-PI staining, ELISA, and qRT-PCR were used. PI3K-Akt-mTOR receptors and thymoquinone were predicted using in-silico docking studies. Cell proliferation is reduced in MDA-MB-231 cells due to ISAT-NC cytotoxicity. As a result of FACS analysis, ISAT-NCs had nuclear damage, ROS production, and elevated annexin-V levels, which resulted in cell cycle arrest in the S phase. The ISAT-NCs in MDA-MB-231 cells were found to downregulate PI3K-Akt-mTOR regulatory pathways in the presence of inhibitors of PI3K-Akt-mTOR, showing that these regulatory pathways are involved in apoptotic cell death. We also predicted the molecular interaction between thymoquinone and PI3K-Akt-mTOR receptor proteins using in-silico docking studies which also support PI3K-Akt-mTOR signaling inhibition by ISAT-NCs in MDA-MB-231 cells. As a result of this study, we can conclude that ISAT-NCs inhibit the PI3K-Akt-mTOR pathway in breast cancer cell lines, causing apoptotic cell death.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism
  5. Discovery of a highly active anticancer analogue of cardamonin that acts as an inducer of caspase-dependent apoptosis and modulator of the mTOR pathway
    Break MKB, Hossan MS, Khoo Y, Qazzaz ME, Al-Hayali MZK, Chow SC, et al.
    Fitoterapia, 2018 Mar;125:161-173.
    PMID: 29355749 DOI: 10.1016/j.fitote.2018.01.006
    Cardamonin is a natural chalcone that has been shown to exhibit high anticancer activity. In an attempt to discover analogues of cardamonin with enhanced anticancer activity, 19 analogues were synthesized and tested against A549 and HK1 cell lines. Results of the MTS cell viability assay showed that several derivatives possessed cytotoxic activities that were several-fold more potent than cardamonin. SAR analysis showed the importance of the ketone and alkene groups for bioactivity, while substituting cardamonin's phenolic groups with more polar moieties resulted in activity enhancement. As part of the SAR study and further exploration of chemical space, the effect of metal coordination on cytotoxicity was also investigated, but it was only possible to successfully obtain the Cu (II) complex of cardamonin (19). Compound 19 was the most active analogue possessing IC50 values of 13.2μM and 0.7μM against A549 and HK1 cells, corresponding to a 5- and 32-fold increase in activity, respectively. It was also able to significantly inhibit the migration of A549 and HK1 cells. Further mode of action studies have shown that the most active analogue, 19, induced DNA damage resulting in G2/M-phase cell- cycle arrest in both cell lines. These events further led to the induction of apoptosis by the compound via caspase-3/7 and caspase-9 activation, PARP cleavage and downregulation of Mcl-1 expression. Moreover, 19 inhibited the expression levels of p-mTOR and p-4EBP1, which indicated that it exerted its anticancer activity, at least in part, via inhibition of the mTOR signalling pathway.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism*
  6. Fulltext Melatonin Induces Autophagy via Reactive Oxygen Species-Mediated Endoplasmic Reticulum Stress Pathway in Colorectal Cancer Cells
    Chok KC, Koh RY, Ng MG, Ng PY, Chye SM
    Molecules, 2021 Aug 20;26(16).
    PMID: 34443626 DOI: 10.3390/molecules26165038
    Even though an increasing number of anticancer treatments have been discovered, the mortality rates of colorectal cancer (CRC) have still been high in the past few years. It has been discovered that melatonin has pro-apoptotic properties and counteracts inflammation, proliferation, angiogenesis, cell invasion, and cell migration. In previous studies, melatonin has been shown to have an anticancer effect in multiple tumors, including CRC, but the underlying mechanisms of melatonin action on CRC have not been fully explored. Thus, in this study, we investigated the role of autophagy pathways in CRC cells treated with melatonin. In vitro CRC cell models, HT-29, SW48, and Caco-2, were treated with melatonin. CRC cell death, oxidative stress, and autophagic vacuoles formation were induced by melatonin in a dose-dependent manner. Several autophagy pathways were examined, including the endoplasmic reticulum (ER) stress, 5'-adenosine monophosphate-activated protein kinase (AMPK), phosphoinositide 3-kinase (PI3K), serine/threonine-specific protein kinase (Akt), and mammalian target of rapamycin (mTOR) signaling pathways. Our results showed that melatonin significantly induced autophagy via the ER stress pathway in CRC cells. In conclusion, melatonin demonstrated a potential as an anticancer drug for CRC.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism
  7. Nanocomposites of iron oxide, sodium alginate, and eugenol induce apoptosis via PI3K/Akt/mTOR signaling in Hep3 cells and in vivo hepatotoxicity in the zebrafish model
    Elderdery AY, Alzerwi NAN, Alzahrani B, Alsrhani A, Alsultan A, Rayzah M, et al.
    Int J Biol Macromol, 2024 Jan;256(Pt 2):127490.
    PMID: 37979758 DOI: 10.1016/j.ijbiomac.2023.127490
    Hepatic cancer is among the most recurrently detected malignancies worldwide and one of the main contributors to cancer-associated mortality. With few available therapeutic choices, there is an instant necessity to explore suitable options. In this aspect, Nanotechnology has been employed to explore prospective chemotherapeutic approaches, especially for cancer treatment. Nanotechnology is concerned with the biological and physical properties of nanoparticles in the therapeutic use of drugs. In the current work, formulation, and characterization of α-Fe2O3-Sodium Alginate-Eugenol nanocomposites (FSE NCs) using several approaches like SEM and TEM, UV-visible, FTIR, and PL spectroscopy, XRD, EDAX, and DLS studies have been performed. With an average size of 50 nm, the rhombohedral structure of NCs was identified. Further, their anticancer activity against Hep3B liver cancer cell lines has been performed by cell viability, dual staining, DCFH-DA, Annexin-V/-FITC/PI, cell cycle analysis methods, and PI3K/Akt/mTOR signaling proteins were studied to assess the anticancer effects of the NCs in Hep3B cells. Also, anti-cancer activity on animal modeling in-vivo using zebra fishes to hematological parameters, liver enzymes, and histopathology study effectiveness was noticed. Moreover, the NCs reduced the viability, elevated the ROS accumulation, diminished the membrane integrity, reduced the antioxidants, blocked the cell cycle, and triggered the PI3K/Akt/mTOR signaling axis that eventually resulted in cell death. As a result, FSE NCs possess huge potential for use as a possible anticancer candidate.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism
  8. Fulltext The role of autophagy-related proteins in the pathogenesis of neuromyelitis optica spectrum disorders
    Guo HL, Shen XR, Liang XT, Li LZ
    Bioengineered, 2022 Jun;13(6):14329-14338.
    PMID: 36694421 DOI: 10.1080/21655979.2022.2084273
    This study aimed to investigate the expression of autophagy-related proteins in a mouse model of neuromyelitis optica (NMO). Mice were assigned to one of four groups: an animal experimental model group (NMO-EAE group, given with exogenous IL-17A), Interleukin-17 monoclonal antibody intervention group (NMO-EAE_0IL17inb), No exogenous interleukin-17 enhanced immune intervention group (NMO-EAE_0IL17), and a control group. Behavioral scores were assessed in each group, and the protein expressions of sequestosome 1 (P62), Beclin-1, the mammalian target of rapamycin (mTOR), phosphoinositide 3-kinase (PI3K-I), and LC3II/LC3I were detected using Western blotting. In the NMO-EAE_0IL17 group, the expression of Beclin-1 decreased, the LC3II/LC3I ratio was lower, and the expressions of P62, mTOR, and PI3K-I increased; after administration of IL-17A inhibitor into the brain tissue, however, the expression of Beclin-1 increased significantly, along with the LC3II/LC3I ratio, while the expressions of P62, mTOR and PI3K-I protein decreased significantly. In terms of behavioral scores, the scores of optic neuritis and myelitis were more serious, onset occurred earlier and the progress was faster, after the administration of IL-17A. In the mechanism of NMO animal model, IL-17A may regulate autophagy and affect the disease process through the activation of the PI3K-mTOR signaling pathway.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism
  9. Fulltext Understanding the Role of ztor in Aging-related Diseases Using the Zebrafish Model
    Khor ES, Noor SM, Wong PF
    In Vivo, 2019 10 31;33(6):1713-1720.
    PMID: 31662495 DOI: 10.21873/invivo.11661
    The mammalian target of rapamycin (mTOR), a 289 kDa serine/threonine protein kinase of the phosphoinositide 3-kinase (PI3K)-related family is known for its role in regulating lifespan and the aging process in humans and rodents. Aging in zebrafish very much resembles aging in humans. Aged zebrafish often manifest with spinal curvature, cataracts and cognitive frailty, akin to human age-related phenotypical effects such as osteoarthritis, dwindling vision and cognitive dysfunction. However, the role of the zebrafish orthologue of mTOR, ztor, is less defined in these areas. This review paper discusses the tale of growing old in the zebrafish, the physiological roles of ztor in normal developmental processes and its involvement in the pathogenesis of aging-related diseases such as metabolic disorders and cancers.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism*
  10. Panduratin A induces protective autophagy in melanoma via the AMPK and mTOR pathway
    Lai SL, Mustafa MR, Wong PF
    Phytomedicine, 2018 Mar 15;42:144-151.
    PMID: 29655680 DOI: 10.1016/j.phymed.2018.03.027
    BACKGROUND: Targeting autophagy is emerging as a promising strategy in cancer therapeutics in recent years. Autophagy can be modulated to drive cancer cell deaths that are notoriously resistant to apoptotic-inducing drugs. In addition, autophagy has been implicated as a prosurvival mechanism in mediating cancer chemoresistance. Our previous study has demonstrated that Panduratin A (PA), a plant-derived active compound exploits ER-stress-mediated apoptosis as its cytotoxic mechanism on melanoma.

    PURPOSE: Our previous proteomics analysis revealed that treatment with PA resulted in the upregulation of an autophagy marker, LC3B in melanoma cells. Therefore, the present study sought to investigate the role of PA-induced autophagy in melanoma cells.

    METHODS: Transmission electron microscopy was performed for examination of autophagic ultra-structures in PA-treated A375 cells. Cytoplasmic LC3B and p62/SQSMT1 punctate structures were detected using immunofluorescene staining. Expression levels of LC3B II, p62/SQSMT1, ATG 12, Beclin 1, phospho S6 (ser235/236), phospho AMPK (Thr172) and cleaved PARP were evaluated by western blotting.

    RESULTS: Autophagosomes, autolysosomes and punctuates of LC3 proteins could be observed in PA-treated A375 cells. PA-induced autophagy in A375 melanoma cells was found to be mediated through the inhibition of mTOR signaling and activation of AMPK pathway. Furthermore, we showed that PA-induced apoptosis was increased in the presence of an autophagy inhibitor, signifying the cytoprotective effect of PA-induced autophagy in melanoma cells.

    CONCLUSION: Taken together, results from the present study suggest that the inhibition of autophagy by targeting mTOR and AMPK could potentiate the cytotoxicity effects of PA on melanoma cells.

    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism*
  11. Caralluma pauciflorabased Ag-NPs activate ROS - induced apoptosis through down-regulation of AKT, mTOR and pI3K signaling in human gastric cancer (AGS) cells
    Navaneethan RD, N C J PL, Ramaiah M, Ravindran R, T AK, Chinnathambi A, et al.
    Nanotechnology, 2024 Feb 21;35(19).
    PMID: 38320329 DOI: 10.1088/1361-6528/ad26d9
    The phytochemicals found inCaralluma pauciflorawere studied for their ability to reduce silver nitrate in order to synthesise silver nanoparticles (AgNPs) and characterise their size and crystal structure. Thunbergol, 1,1,6-trimethyl-3-methylene-2-(3,6,9,13-tetram, Methyl nonadecanoate, Methyl cis-13,16-Docosadienate, and (1R,4aR,5S)-5-[(E)-5-Hydroxy-3-methylpent were the major compounds identified in the methanol extract by gas chromatography-mass spectrum analysis. UV/Vis spectra, Fourier-transform infrared spectroscopy, x-ray diffraction, scanning electron microscope with Energy Dispersive Xâray Analysis (EDAX), Dynamic Light Scattering (DLS) particle size analyser and atomic force microscope (AfM) were used to characterise theCaralluma paucifloraplant extract-based AgNPs. The crystal structure and estimated size of the AgNPs ranged from 20.2 to 43 nm, according to the characterization data. The anti-cancer activity of silver nanoparticles (AgNPs) synthesised fromCaralluma paucifloraextract. The AgNPs inhibited more than 60% of the AGS cell lines and had an IC50 value of 10.9640.318 g, according to the findings. The cells were further examined using fluorescence microscopy, which revealed that the AgNPs triggered apoptosis in the cells. Furthermore, the researchers looked at the levels of reactive oxygen species (ROS) in cells treated with AgNPs and discovered that the existence of ROS was indicated by green fluorescence. Finally, apoptotic gene mRNA expression analysis revealed that three target proteins (AKT, mTOR, and pI3K) were downregulated following AgNP therapy. Overall, the findings imply that AgNPs synthesised from Caralluma pauciflora extract could be used to treat human gastric cancer.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism
  12. Fulltext Curculigoside and polyphenol-rich ethyl acetate fraction of Molineria latifolia rhizome improved glucose uptake via potential mTOR/AKT activated GLUT4 translocation
    Ooi J, Azmi NH, Imam MU, Alitheen NB, Ismail M
    J Food Drug Anal, 2018 10;26(4):1253-1264.
    PMID: 30249324 DOI: 10.1016/j.jfda.2018.03.003
    Adipose tissue is one of the major organs responsible for rapid restoration of postprandial glucose fluxes. Being the major isoform of glucose transporter in adipose tissue, regulations of insulin-dependent GLUT4 trafficking have always been of research interest. The present study aimed to examine the molecular mechanisms underlying the efficacy of curculigoside and polyphenol-rich ethyl acetate fraction (EAF) of Molineria latifolia rhizome in triggering glucose uptake. We assessed the adipogenic potential and glucose uptake stimulatory activity of curculigoside and EAF by employing a murine 3T3-L1 adipocyte model. The transcriptional and translational expressions of selected intermediates in the insulin signalling pathway were evaluated. While curculigoside neither promoted adipogenesis nor activated peroxisome proliferator activated receptor gamma, treatment with polyphenol-rich EAF resulted otherwise. However, both treatments enhanced insulin-stimulated uptake of glucose. This was coupled with increased availability of GLUT4 at the plasma membrane of the differentiated adipocytes although the total GLUT4 protein level was unaffected. In addition, the treatment increased the phosphorylation of both AKT and mTOR, which have been reported to be associated with GLUT4 translocation. The present findings proposed that curculigoside and EAF increased glucose transport activity of 3T3-L1 adipocytes via GLUT4 translocation as a result of potential mTOR/AKT activation. The more potent efficacy observed with EAF suggested potential synergistic and multi-targeted action.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism*
  13. para-Phenylenediamine induces apoptosis through activation of reactive oxygen species-mediated mitochondrial pathway, and inhibition of the NF-κB, mTOR, and Wnt pathways in human urothelial cells
    Reena K, Ng KY, Koh RY, Gnanajothy P, Chye SM
    Environ Toxicol, 2017 Jan;32(1):265-277.
    PMID: 26784575 DOI: 10.1002/tox.22233
    para-Phenylenediamine (PPD) has long been used in two-thirds of permanent oxidative hair dye formulations. Epidemiological studies and in vivo studies have shown that hair dye is a suspected carcinogen of bladder cancer. However, the toxicity effects of PPD to human bladder remains elusive. In this study, the effects of PPD and its involvement in the apoptosis pathways in human urothelial cells (UROtsa) was investigated. It was demonstrated that PPD decreased cell viability and increased the number of sub-G1 hypodiploid cells in UROtsa cells. Cell death due to apoptosis was detected using Annexin V binding assay. Further analysis showed PPD generated reactive oxygen species (ROS), induced mitochondrial dysfunction through the loss of mitochondrial membrane potential and increased caspase-3 level in UROtsa cells. Western blot analysis of PPD-treated UROtsa cells showed down-regulation of phosphorylated proteins from NF-κB, mTOR, and Wnt pathways. In conclusion, PPD induced apoptosis via activation of ROS-mediated mitochondrial pathway, and possibly through inhibition of NF-κB, mTOR, and Wnt pathways. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 265-277, 2017.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism
  14. Mutations in the mammalian target of rapamycin pathway regulators NPRL2 and NPRL3 cause focal epilepsy
    Ricos MG, Hodgson BL, Pippucci T, Saidin A, Ong YS, Heron SE, et al.
    Ann Neurol, 2016 Jan;79(1):120-31.
    PMID: 26505888 DOI: 10.1002/ana.24547
    Focal epilepsies are the most common form observed and have not generally been considered to be genetic in origin. Recently, we identified mutations in DEPDC5 as a cause of familial focal epilepsy. In this study, we investigated whether mutations in the mammalian target of rapamycin (mTOR) regulators, NPRL2 and NPRL3, also contribute to cases of focal epilepsy.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism*
  15. Dual mTORC1/mTORC2 blocker as a possible therapy for tauopathy in cellular model
    Salama M, Elhussiny M, Magdy A, Omran AG, Alsayed A, Ashry R, et al.
    Metab Brain Dis, 2018 04;33(2):583-587.
    PMID: 29080085 DOI: 10.1007/s11011-017-0137-7
    Tauopathy comprises a group of disorders caused by abnormal aggregates of tau protein. In these disorders phosphorylated tau protein tends to accumulate inside neuronal cells (soma) instead of the normal axonal distribution of tau. A suggested therapeutic strategy for tauopathy is to induce autophagy to increase the ability to get rid of the unwanted tau aggregates. One of the key controllers of autophagy is mTOR. Blocking mTOR leads to stimulation of autophagy. Recently, unravelling molecular structure of mTOR showed that it is formed of two subunits: mTORC1/C2. So, blocking both subunits of mTOR seems more attractive as it will explore all abilities of mTOR molecule. In the present study, we report using pp242 which is a dual mTORC1/C2 blocker in cellular model of tauopathy using LUHMES cell line. Adding fenazaquin to LUHMES cells induced tauopathy in the form of increased phospho tau aggregates. Moreover, fenazaquin treated cells showed the characteristic somatic redistribution of tau. PP242 use in the present tauopathy model reversed the pathology significantly without observable cellular toxicity for the used dosage of 1000 nM. The present study suggests the possible use of pp242 as a dual mTOR blocker to treat tauopathy.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism
  16. siRNA Blocking of Mammalian Target of Rapamycin (mTOR) Attenuates Pathology in Annonacin-Induced Tauopathy in Mice
    Salama M, El-Desouky S, Alsayed A, El-Hussiny M, Magdy K, Fekry E, et al.
    Neurotox Res, 2019 May;35(4):987-992.
    PMID: 30362086 DOI: 10.1007/s12640-018-9974-3
    Tauopathy is a pathological hallmark of many neurodegenerative diseases. It is characterized by abnormal aggregates of pathological phosphotau and somatodendritic redistribution. One suggested strategy for treating tauopathy is to stimulate autophagy, hence, getting rid of these pathological protein aggregates. One key controller of autophagy is mTOR. Since stimulation of mTOR leads to inhibition of autophagy, inhibitors of mTOR will cause stimulation of autophagy process. In this report, tauopathy was induced in mice using annonacin. Blocking of mTOR was achieved through stereotaxic injection of siRNA against mTOR. The behavioral and immunohistochemical evaluation revealed the development of tauopathy model as proven by deterioration of behavioral performance in open field test and significant tau aggregates in annonacin-treated mice. Blocking of mTOR revealed significant clearance of tau aggregates in the injected side; however, tau expression was not affected by mTOR blockage.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism
  17. Fulltext Upregulation of miR-101 during Influenza A Virus Infection Abrogates Viral Life Cycle by Targeting mTOR Pathway
    Sharma S, Chatterjee A, Kumar P, Lal S, Kondabagil K
    Viruses, 2020 04 15;12(4).
    PMID: 32326380 DOI: 10.3390/v12040444
    Micro RNAs (miRNAs) are a class of small non-coding single-stranded RNA, which play an important role in modulating host-Influenza A virus (IAV) crosstalk. The interplay between influenza and miRNA interaction is defined by a plethora of complex mechanisms, which are not fully understood yet. Here, we demonstrate that in IAV infected A549 cells, a synchronous increase was observed in the expression of mTOR up to 24 hpi and significant downregulation at 48 hpi. Additionally, NP of IAV interacts with mTOR and modulates the levels of mTOR mRNA and protein, thus regulating the translation of host cell. RNA sequencing and qPCR analysis of IAV-infected A549 cells and NP transfected cells revealed that miR-101 downregulates mTOR transcripts at later stages of infection. Ectopic expression of miR-101 mimic led to a decrease in expression of NP, a reduction in IAV titer and replication. Moreover, treatment of the cells with Everolimus, a potent inhibitor of mTOR, resulted in an increase of miR-101 transcript levels, which further suppressed the viral protein synthesis. Collectively, the data suggest a novel mechanism that IAV stimulates mTOR pathway at early stages of infection; however, at a later time-point, positive regulation of miR-101 restrains the mTOR expression, and hence, the viral propagation.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism*
  18. Fulltext A KLF6-driven transcriptional network links lipid homeostasis and tumour growth in renal carcinoma
    Syafruddin SE, Rodrigues P, Vojtasova E, Patel SA, Zaini MN, Burge J, et al.
    Nat Commun, 2019 03 11;10(1):1152.
    PMID: 30858363 DOI: 10.1038/s41467-019-09116-x
    Transcriptional networks are critical for the establishment of tissue-specific cellular states in health and disease, including cancer. Yet, the transcriptional circuits that control carcinogenesis remain poorly understood. Here we report that Kruppel like factor 6 (KLF6), a transcription factor of the zinc finger family, regulates lipid homeostasis in clear cell renal cell carcinoma (ccRCC). We show that KLF6 supports the expression of lipid metabolism genes and promotes the expression of PDGFB, which activates mTOR signalling and the downstream lipid metabolism regulators SREBF1 and SREBF2. KLF6 expression is driven by a robust super enhancer that integrates signals from multiple pathways, including the ccRCC-initiating VHL-HIF2A pathway. These results suggest an underlying mechanism for high mTOR activity in ccRCC cells. More generally, the link between super enhancer-driven transcriptional networks and essential metabolic pathways may provide clues to the mechanisms that maintain the stability of cell identity-defining transcriptional programmes in cancer.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism
  19. Temporal proteomic profiling of Chlamydia trachomatis-infected HeLa-229 human cervical epithelial cells
    Tan GM, Lim HJ, Yeow TC, Movahed E, Looi CY, Gupta R, et al.
    Proteomics, 2016 05;16(9):1347-60.
    PMID: 27134121 DOI: 10.1002/pmic.201500219
    Chlamydia trachomatis is the leading causative agent of bacterial sexually transmitted infections worldwide which can lead to female pelvic inflammatory disease and infertility. A greater understanding of host response during chlamydial infection is essential to design intervention technique to reduce the increasing incidence rate of genital chlamydial infection. In this study, we investigated proteome changes in epithelial cells during C. trachomatis infection by using an isobaric tags for relative and absolute quantitation (iTRAQ) labeling technique coupled with a liquid chromatography-tandem mass spectrometry (LC-MS(3) ) analysis. C. trachomatis (serovar D, MOI 1)-infected HeLa-229 human cervical carcinoma epithelial cells (at 2, 4 and 8 h) showed profound modifications of proteome profile which involved 606 host proteins. MGST1, SUGP2 and ATXN10 were among the top in the list of the differentially upregulated protein. Through pathway analysis, we suggested the involvement of eukaryotic initiation factor 2 (eIF2) and mammalian target of rapamycin (mTOR) in host cells upon C. trachomatis infection. Network analysis underscored the participation of DNA repair mechanism during C. trachomatis infection. In summary, intense modifications of proteome profile in C. trachomatis-infected HeLa-229 cells indicate complex host-pathogen interactions at early phase of chlamydial infection.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism
  20. The mTOR signalling pathway in cancer and the potential mTOR inhibitory activities of natural phytochemicals
    Tan HK, Moad AI, Tan ML
    Asian Pac J Cancer Prev, 2014;15(16):6463-75.
    PMID: 25169472
    The mammalian target of rapamycin (mTOR) kinase plays an important role in regulating cell growth and cell cycle progression in response to cellular signals. It is a key regulator of cell proliferation and many upstream activators and downstream effectors of mTOR are known to be deregulated in various types of cancers. Since the mTOR signalling pathway is commonly activated in human cancers, many researchers are actively developing inhibitors that target key components in the pathway and some of these drugs are already on the market. Numerous preclinical investigations have also suggested that some herbs and natural phytochemicals, such as curcumin, resveratrol, timosaponin III, gallic acid, diosgenin, pomegranate, epigallocatechin gallate (EGCC), genistein and 3,3'-diindolylmethane inhibit the mTOR pathway either directly or indirectly. Some of these natural compounds are also in the clinical trial stage. In this review, the potential anti-cancer and chemopreventive activities and the current status of clinical trials of these phytochemicals are discussed.
    Matched MeSH terms: TOR Serine-Threonine Kinases/metabolism
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