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Mammalian target of rapamycin (mTOR) is a member of the PI3K/Akt/mTOR signaling pathway that participates in cell growth, proliferation, protein synthesis, transcription, angiogenesis, apoptosis and autophagy. We investigated the role of mTOR and other signaling molecules in the rat uterus during implantation. Female pregnant rats were divided into three groups: embryonic days (ED) 4.5, 5.5 and 6.5 according to vaginal smears. Immunohistochemical staining of mTORC1, mTORC2, IGF1, PI3K, pAkt1/2/3, ERK1 and pERK1/2 was performed on formalin fixed, paraffin embedded uterine tissue samples. pAkt1/2/3 and ERK1 also were analyzed using western blotting. We found that PI3K/Akt/mTOR and ERK/pERK were increased during the implantation period. Different amounts of mTORC1, mTORC2, IGF1, PI3K, pAKT1/2/3, ERK1 and pERK1/2 were expressed in luminal epithelium, decidual cells, embryoblast and trophoblast cells during implantation. We suggest that mTOR and associated signaling molecules may participate in implantation. Celal Bayar Üniversitesi Bilimsel Araştırma Proje Komitesi - 2011/038

Special Issue: Focused Ultrasound in Parkinson's Disease., [Background] Single nucleotide polymorphisms (SNPs) in the α‐synuclein (SNCA ) gene are associated with differential risk and age at onset (AAO) of both idiopathic and Leucine‐rich repeat kinase 2 (LRRK2)‐associated Parkinson's disease (PD). Yet potential combinatory or synergistic effects among several modulatory SNPs for PD risk or AAO remain largely underexplored., [Objectives] The mechanistic target of rapamycin (mTOR ) signaling pathway is functionally impaired in PD. Here we explored whether SNPs in the mTOR pathway, alone or by epistatic interaction with known susceptibility factors, can modulate PD risk and AAO., [Methods] Based on functional relevance, we selected a total of 64 SNPs mapping to a total of 57 genes from the mTOR pathway and genotyped a discovery series cohort encompassing 898 PD patients and 921 controls. As a replication series, we screened 4170 PD and 3014 controls available from the International Parkinson's Disease Genomics Consortium., [Results] In the discovery series cohort, we found a 4‐loci interaction involving STK11 rs8111699, FCHSD1 rs456998, GSK3B rs1732170, and SNCA rs356219, which was associated with an increased risk of PD (odds ratio = 2.59, P, [Conclusions] These findings indicate that genetic variability in the mTOR pathway contributes to SNCA effects in a nonlinear epistatic manner to modulate differential AAO in PD, unraveling the contribution of this cascade in the pathogenesis of the disease. © 2019 International Parkinson and Movement Disorder Society, Funding Information; Fundació la Marató de TV3. Grant Number: 60510; Michael J. Fox Foundation for Parkinson's Research. Grant Numbers: Dyskinesia Challenge 2014, MJF_PPMI_10_001, PI044024; National Institutes of Health. Grant Number: LM010098; Secretaría de Estado de Investigación, Desarrollo e Innovación. Grant Number: SAF2014‐57160R and SAF2017‐88812R.

PubMed ID: 31247220 As seen in other types of cancer, development of drug resistance in NSCLC treatment causes adverse effects on disease fighting process. Recent studies have shown that one of the drug resistance development mechanisms is that cancer cells may acquire the ability to escape from cell death. Therefore, development of anticancer drugs which have the strategy to redirect cancer cells to any cell death pathways may provide positive results for cancer treatments. Autophagy may be a target mechanism of alternative cancer treatment strategy in cases of blocked apoptosis. There is also a complex molecular link between autophagy and apoptosis, has not been fully understood yet. The dicyano compound which we used in our study caused cell death in NSCLC cell lines. When we analyzed the cells which were treated with dicyano compound by transmission electron microscope, we observed autophagosome structures. Upon this result, we investigated expression levels of autophagic proteins in the dicyano compound-treated cells by immunoblotting and observed that expression levels of autophagic proteins were increased significantly. The TUNEL assay and qRT-PCR for pro-apoptotic and anti-apoptotic gene expression, which we performed to assess apoptosis in the dicyano compound-treated cells, showed that the cell death does not occur through apoptotic pathway. We showed that the dicyano compound, which was developed in our laboratories, may play a role in molecular link between apoptosis and autophagy and may shed light on development of new anticancer treatment strategies. © 2019 Elsevier B.V. 2017SAE024 We are grateful to Dr. Nedim KARAGENC because of his valuable contributions. This study was supported by Pamukkale University Research Foundation ( 2017SAE024 ).

The allocation of nutrient resources to growth and metabolism is an essential function for controlling biomass accumulation in photoautotrophic organisms. One essential protein complex involved in this process is the target of rapamycin (TOR) kinase. It has been shown that the inhibition of TOR leads to a considerable upsurge in the amino acid levels. This molecular phenotype relies mainly on the availability of light, carbon (C) and nitrogen (N). To validate the time-resolved response of C and N metabolites, we used a targeted gas chromatography mass spectrometery (GC-MS)-based metabolomic approach, where we examined the response of Chlamydomonas reinhardtii upon TOR inhibition under C-limited condition, namely extended darkness. Contrary to C-supplemented conditions, the rapid increase in the amino acid levels is suppressed almost completely 4 h after TOR inhibition, confirming that C supply is essential to raise the amino acid levels mediated by their de novo synthesis. An exception to this observation was the levels of aspartate, which is presumably synthesized via the anaplerotic pathway. In agreement with previous reports, TOR repression, under these C-limited conditions, leads to a significant reduction in the C/N ratio, corroborating with the crucial role of the pathway in maintaining the metabolic balance of the cells and consequently propelling growth.

Combinatorial targeted therapies are more effective in treating cancer by blocking by-pass mechanisms or inducing synthetic lethality. However, their clinical application is hampered by resistance and toxicity. To meet this important challenge, we developed and tested a novel concept of biomarker-guided sequential applications of various targeted therapies using ErbB2-overexpressing/PTEN-low, highly aggressive breast cancer as our model. Strikingly, sustained activation of ErbB2 and downstream pathways drives trastuzumab resistance in both PTEN-low/trastuzumab-resistant breast cancers from patients and mammary tumors with intratumoral heterogeneity from genetically-engineered mice. Although lapatinib initially inhibited trastuzumab-resistant mouse tumors, tumors by-passed the inhibition by activating the PI3K/mTOR signaling network as shown by the quantitative protein arrays. Interestingly, activation of the mTOR pathway was also observed in neoadjuvant lapatinib-treated patients manifesting lapatinib resistance. Trastuzumab + lapatinib resistance was effectively overcome by sequential application of a PI3K/mTOR dual kinase inhibitor (BEZ235) with no significant toxicity. However, our p-RTK array analysis demonstrated that BEZ235 treatment led to increased ErbB2 expression and phosphorylation in genetically-engineered mouse tumors and in 3-D, but not 2-D, culture, leading to BEZ235 resistance. Mechanistically, we identified ErbB2 protein stabilization and activation as a novel mechanism of BEZ235 resistance, which was reversed by subsequent treatment with lapatinib + BEZ235 combination. Remarkably, this sequential application of targeted therapies guided by biomarker changes in the tumors rapidly evolving resistance doubled the life-span of mice bearing exceedingly aggressive tumors. This fundamentally novel approach of using targeted therapies in a sequential order can effectively target and reprogram the signaling networks in cancers evolving resistance during treatment. © 2014 IBCB, SIBS, CAS All rights reserved.

The signaling pathway AKT/mTOR is a central axis in regulating cellular processes, particularly in neurological diseases. In the case of epilepsy, it has been observed alteration in the pathophysiological process of the same. However, they have not described all the mechanisms of these signaling pathways that could open the opportunity to new research and therapeutic strategies.To review existing partnerships between intracellular signaling pathways AKT and mTOR in the pathophysiology of epilepsy.Epilepsy is a disease with a high epidemiological impact globally, so it is widely investigated regarding the pathophysiological components thereof. In that search they have been involved different intracellular signaling pathways in neurons, as determinants epileptogenic. Advances in this field have even allowed the successful implementation of new therapeutic strategies and to open the way to new research in the field.Improving knowledge about the pathophysiological role of the signaling pathway mTOR/AKT in epilepsy can raise new investigations regarding therapeutic alternatives. The use of mTOR inhibitors, has emerged in recent years as effective in treating this disease entity alternative however is clear the necessity of continue the research for new drug therapies.Vias de señalizacion mTOR y AKT en epilepsia.Introduccion. La via de señalizacion AKT/mTOR es un eje central en la regulacion celular, especialmente en las enfermedades neurologicas. En la epilepsia, se ha evidenciado su alteracion dentro de su proceso fisiopatologico. Sin embargo, aun no se han descrito todos los mecanismos de estas rutas de señalizacion, las cuales podrian abrir la puerta hacia nuevas investigaciones y estrategias terapeuticas, que finalmente permitan desarrollar tratamientos efectivos en enfermedades neurologicas como la epilepsia. Objetivo. Revisar las asociaciones existentes entre las rutas de señalizacion intracelular de mTOR y AKT en la fisiopatologia de la epilepsia. Desarrollo. La epilepsia es una enfermedad neurologica con un alto impacto epidemiologico en el mundo, por lo cual es de sumo interes la investigacion de los componentes fisiopatologicos que puedan generar nuevos tratamientos farmacologicos. En esta busqueda se han involucrado diferentes rutas de señalizacion intracelular en neuronas, como determinantes epileptogenos. Los avances en esta materia han permitido incluso la implementacion de nuevas estrategias terapeuticas exitosas y que abren el camino hacia nuevas investigaciones. Conclusiones. Mejorar los conocimientos respecto al papel fisiopatologico de la via de señalizacion mTOR/AKT en la epilepsia permite plantear nuevas investigaciones que ofrezcan nuevas alternativas terapeuticas para el tratamiento de la enfermedad. El uso de inhibidores de mTOR ha surgido en los ultimos años como una alternativa eficaz en el tratamiento de algunos tipos de epilepsias, pero es evidente la necesidad de seguir en la busqueda de nuevas terapias farmacologicas involucradas en estas vias de señalizacion.

Mechanistic target of rapamycin (mTOR) is a conserved serine/threonine kinase important in cell proliferation, growth and protein translation. Rapamycin, a well-known anti-cancer agent and immunosuppressant drug, inhibits mTOR activity in different taxa including zebrafish. In the present study, the effect of rapamycin exposure on the transcriptome of a zebrafish fibroblast cell line, ZF4, was investigated. Microarray analysis demonstrated that rapamycin treatment modulated a large set of genes with varying functions including protein synthesis, assembly of mitochondrial and proteasomal machinery, cell cycle, metabolism and oxidative phosphorylation in ZF4 cells. A mild however, coordinated reduction in the expression of proteasomal and mitochondrial ribosomal subunits was detected, while the expression of numerous ribosomal subunits increased. Meta-analysis of heterogeneous mouse rapamycin microarray datasets enabled the comparison of zebrafish and mouse pathways modulated by rapamycin, using Kyoto Encyclopedia of Genes and Genomes and Gene Ontology pathway analysis. The analyses demonstrated a high degree of functional conservation between zebrafish and mice in response to rapamycin. In addition, rapamycin treatment resulted in a marked dose-dependent reduction in body size and pigmentation in zebrafish embryos. The present study is the first, to the best of our knowledge, to evaluate the conservation of rapamycin-modulated functional pathways between zebrafish and mice, in addition to the dose-dependent growth curves of zebrafish embryos upon rapamycin exposure.

International audience; The mTOR (mammalian target of rapamycin) signal transduction pathway integrates various signals, regulating ribosome biogenesis and protein synthesis as a function of available energy and amino acids, and assuring an appropriate coupling of cellular proliferation with increases in cell size. In addition, recent evidence has pointed to an interplay between the mTOR and p53 pathways. We investigated the genetic variability of 67 key genes in the mTOR pathway and in genes of the p53 pathway which interact with mTOR. We tested the association of 1,084 tagging SNPs with prostate cancer risk in a study of 815 prostate cancer cases and 1,266 controls nested within the European Prospective Investigation into Cancer and Nutrition (EPIC). We chose the SNPs (n = 11) with the strongest association with risk (p

Various mitogenic or growth inhibitory stimuli induce a rapid change in the association of terminal oligopyrimidine (TOP) mRNAs with polysomes. It is generally believed that such translational control hinges on the mammalian target of rapamycin (mTOR)-S6 kinase pathway. Amino acid availability affects the translation of TOP mRNAs, although the signaling pathway involved in this regulation is less well characterized. To investigate both serum- and amino acid-dependent control of TOP mRNA translation and the signaling pathways involved, HeLa cells were subjected to serum and/or amino acid deprivation and stimulation. Our results indicate the following. 1). Serum and amino acid deprivation had additive effects on TOP mRNA translation. 2). The serum content of the medium specifically affected TOP mRNA translation, whereas amino acid availability affected both TOP and non-TOP mRNAs. 3). Serum signaling to TOP mRNAs involved only a rapamycin-sensitive pathway, whereas amino acid signaling depended on both rapamycin-sensitive and rapamycin-insensitive but wortmannin-sensitive events. 4). Eukaryotic initiation factor-2alpha phosphorylation increased during amino acid deprivation, but not following serum deprivation. Interestingly, rapamycin treatment suggests a novel connection between the mTOR pathway and eukaryotic initiation factor-2alpha phosphorylation in mammalian cells, which may not, however, be involved in TOP mRNA translational regulation.

Many adverse effects of glucose were attributed to its increased routing through the hexosamine pathway (HBP). There is evidence for an autocrine role of the insulin signaling in β-cell function. We tested the hypothesis that activation of the HBP induces defects in insulin biosynthesis by affecting the insulin-mediated protein translation signaling. Exposure of human pancreatic islets and RIN β-cells to glucosamine resulted in reduction in glucose- and insulin-stimulated insulin biosynthesis, which in RIN β-cells was associated with impairment in insulin-stimulated insulin receptor substrate-1 (IRS-1) phosphorylation at Tyr608 and Tyr628, which are essential for engaging phosphatidylinositol 3-kinase (PI 3-kinase). These changes were accompanied by impaired activation of PI 3-kinase, and activation of Akt/mammalian target of rapamycin/phosphorylated heat- and acid-stable protein-1/p70S6 kinase pathway. RIN β-cells exposed to high glucose exhibited increased c-Jun N-terminal kinase (JNK) and ERK1/2 activity, which was associated with increased IRS-1 phosphorylation at serine (Ser)307 and Ser612, respectively, that inhibits coupling of IRS-1 to the insulin receptor and is upstream of the inhibition of IRS-1 tyrosine phosphorylation. Azaserine reverted the stimulatory effects of high glucose on JNK and ERK1/2 activity and IRS-1 phosphorylation at Ser307 and Ser612. Glucosamine mimicked the stimulatory effects of high glucose on JNK and ERK1/2 activity and IRS-1 phosphorylation at Ser307 and Ser612. Inhibition of JNK and MAPK kinase-1 activity reverted the negative effects of glucosamine on insulin-mediated protein synthesis. These results suggest that activation of the HBP accounts, in part, for glucose-induced phosphorylation at Ser307 and Ser612 of IRS-1 mediated by JNK and ERK1/2, respectively. These changes result in impaired coupling of IRS-1 and PI 3-kinase, and activation of the Akt/mammalian target of rapamycin/phosphorylated heat- and acid-stable protein-1/p70S6 kinase pathway.