Regulation of neuronal gene expression and survival by basal NMDA receptor activity: a role for Histone Deacetylase 4
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ABSTRACT: Gene expression analysisis of NR2A and NR2B containing NMDA receptors after treatment with AP5, NVP-AAM077 and Ro25-6981 4 conditions, vehicle, AP5, Ro25, and NVP, 4-5 replicates of each sample
Project description:Nevirapine (NVP), a non-nucleoside reverse transcriptase inhibitor widely used in combined antiretroviral therapy and to prevent mother-to-child transmission of the human immunodefi-ciency virus type 1, is associated with several adverse side effects. Using 12-mesyloxy-nevirapine, a model electrophile of the reactive metabolites derived from the NVP Phase I metabolite, 12-hydroxy-NVP, we demonstrate that the nucleophilic core and C-terminal residues of histones are targets for covalent adduct formation. We identified multiple NVP-modification sites at lysine (e.g. H2BK47, H4K32), histidine (e.g. H2BH110, H4H76) and serine (e.g. H2BS33) residues of the four histones using a mass spectrometry-based bottom-up proteomic analysis. In particular, H2BK47, H2BH110, H2AH83 and H4H76 were evidenced to be potential hot spots for NVP incorporation. In fact, a remarkable selectivity to the imidazole ring of histidine was observed: 3 out of the 11 histidine residues of histones were NVP-modified. This suggests that NVP-modified histidine residues of histones are prospective markers of this an-ti-HIV drug bioactivation and/or toxicity. Importantly, NVP-derived modifications were iden-tified at sites known to determine chromatin structure (e.g. H4H76) and that can undergo multi-ple types of PTMs (e.g. H2BK47, H4H76). These results open new insights into the molecular mechanisms of drug-induced adverse reactions.
Project description:Ewing's Sarcoma cell lines were made resistant to different IGF-1R drugs to investigate mechanisms and pathways modulated by the resistance. EWS TC-71 cell line was exposed to increasing concentration to three different anti-IGF-1R drugs (HAb AVE1642, TKI NVP-AEW541, HAb CP-751,871, cell lines named respectively as TC/AVE, TC/AEW or TC/CP) for at least six months. Expression profile of resistant cell variants was compared either singularly for each resistance or commonly vs. parental cell line. Two technical replicates for resistant variants and three biological replicated for parental cell were present.
Project description:Protein kinases are prime targets for drug development due to their involvement in various cancers. However, selective inhibition of kinases, while avoiding off-target effects remains a significant challenge for the development of protein kinase inhibitors. Activity-based protein profiling (ABPP), in combination with pan-kinase activity-based probes (ABPs) and mass spectrometry-based proteomics, enables the identification of kinase drug targets. Here, we extend existing ABPP strategies for kinase profiling with a site-specific analysis, allowing for protein kinase inhibitor target engagement profiling with amino acid specificity. The site-specific approach involves highly efficient enrichment of ABP-labeled peptides, resulting in a less complex peptide matrix, straightforward data analysis, and the screening of over ~100 kinase active sites in a single LC-MS run. The use of both trypsin and pepsin in parallel to generate the ABP-labeled peptides considerably expanded the coverage of kinases and exact binding sites. Using the site-specific strategy to examine the on- and off-targets of the Ephrin receptor (Eph) B4 inhibitor NVP-BHG712 showed binding to EphA2 with an IC50 of 17 nM (95% CI 10 - 28 nM) and EphB4 with an IC50 of 20.2 nM (95% CI 13.7 - 30.4 nM). Next to the known targets, EphA2 and EphB4, NVP-BHG712 bound to the discoidin domain-containing receptor 1 (DDR1) with an IC50 of 2.1 nM (95% CI 1.3 - 3.4 nM), suggesting that a DDR1-targeting regioisomer of NVP-BHG712 was analyzed. The promiscuity of XO44 toward ATP-binding pockets on other proteins facilitated the screening of an additional 475 sites, revealing inosine-5’-monophosphate dehydrogenase 2 (IMPDH2) as an off-target. Therefore, the presented approach, which can be fully automated with liquid handling platforms, provides a straightforward, valuable strategy for competitive site-specific kinase inhibitor target profiling.
Project description:The N-methyl-d-aspartate (NMDA) receptor is a glutamate-activated cation channel critical to many processes in the brain. Genome-wide association studies (GWAS) suggest that glutamatergic neurotransmission and NMDA receptor-mediated synaptic plasticity is important for body weight homeostasis1. Here, we report the engineering and preclinical development of a first-in-class bimodal molecule that integrates NMDA receptor antagonism with glucagon-like peptide-1 (GLP-1) receptor agonism to effectively reverse obesity, hyperglycemia, and dyslipidemia in rodent models of metabolic disease. We demonstrate that GLP-1-directed delivery of the NMDA receptor antagonist MK-801 affects NMDA receptor-mediated synaptic plasticity in the hypothalamus. Importantly, peptide-targeting of MK-801 specifically to GLP-1 receptor-expressing brain regions circumvent adverse physiological and behavioral effects associated with MK-801 monotherapy. In sum, our approach demonstrates the feasibility of cell specific ionotropic receptor-modulation via peptide targeting and highlights the therapeutic potential of unimolecular mixed GLP-1 receptor agonism and NMDA receptor antagonism for obesity treatment.
Project description:The N-methyl-d-aspartate (NMDA) receptor is a glutamate-activated cation channel critical to many processes in the brain. Genome-wide association studies (GWAS) suggest that glutamatergic neurotransmission and NMDA receptor-mediated synaptic plasticity is important for body weight homeostasis1. Here, we report the engineering and preclinical development of a first-in-class bimodal molecule that integrates NMDA receptor antagonism with glucagon-like peptide-1 (GLP-1) receptor agonism to effectively reverse obesity, hyperglycemia, and dyslipidemia in rodent models of metabolic disease. We demonstrate that GLP-1-directed delivery of the NMDA receptor antagonist MK-801 affects NMDA receptor-mediated synaptic plasticity in the hypothalamus. Importantly, peptide-targeting of MK-801 specifically to GLP-1 receptor-expressing brain regions circumvent adverse physiological and behavioral effects associated with MK-801 monotherapy. In sum, our approach demonstrates the feasibility of cell specific ionotropic receptor-modulation via peptide targeting and highlights the therapeutic potential of unimolecular mixed GLP-1 receptor agonism and NMDA receptor antagonism for obesity treatment.
Project description:Analysis of the effects of a dual specificity PI3K/mTOR inhibitor on two human ovarian cell lines, OV2008 and MCAS. Results provide insight into the adaptive response to PI3K/mTOR inhibition in matrix attached ovarian cancer cells. The PI3K/mTOR-pathway is the most commonly deregulated pathway in epithelial cancers and thus represents an important target for cancer therapeutics. Here we show that dual inhibition of PI3K/mTOR in ovarian cancer 3D-spheroids leads to death of the inner matrix-deprived cells, whereas matrix-attached cells are resistant. Resistance is associated with up-regulation of a cellular survival program that involves both FOXO-regulated transcription and a novel translational resistance mechanism resulting in specific up-regulation of IRES-mediated, cap-independent translation. Inhibition of any of several up-regulated proteins, including Bcl-2, EGFR, or IGF1R, abrogates resistance to dual PI3K/mTOR inhibition. These results demonstrate that acute adaptive response to PI3K/mTOR inhibition resembles well-conserved adaptive response to nutrient and growth factor deprivation and how development of rational drug combinations can bypass resistance mechanisms. Total RNA was isolated 6h and 24h after treatment with 1 M-NM-<M NVP-BEZ235 or DMSO vehicle control from 3D grown structures
Project description:The N-methyl-D-aspartate (NMDA) receptor is a glutamate-activated cation channel critical to many processes in the brain. Genome-wide association studies (GWAS) suggest that glutamatergic neurotransmission and NMDA receptor-mediated synaptic plasticity is important for body weight homeostasis1. Here, we report the engineering and preclinical development of a first-in-class bimodal molecule that integrates NMDA receptor antagonism with glucagon-like peptide-1 (GLP-1) receptor agonism to effectively reverse obesity, hyperglycemia, and dyslipidemia in rodent models of metabolic disease. We demonstrate that GLP-1-directed delivery of the NMDA receptor antagonist MK-801 affects NMDA receptor-mediated synaptic plasticity in the hypothalamus. Importantly, peptide-targeting of MK-801 specifically to GLP-1 receptor-expressing brain regions circumvent adverse physiological and behavioral effects associated with MK-801 monotherapy. In sum, our approach demonstrates the feasibility of cell specific ionotropic receptor-modulation via peptide targeting and highlights the therapeutic potential of unimolecular mixed GLP-1 receptor agonism and NMDA receptor antagonism for obesity treatment.
Project description:Ewing Sarcoma is caused by a pathognomonic genomic translocation that places an N-terminal EWSR1 gene in approximation with one of several ETS genes (typically FLI1). This aberration, in turn, alters the transcriptional regulation of more than five hundred genes and perturbs a number of critical pathways that promote oncogenesis, cell growth, invasion, and metastasis. Among them, translocation-mediated up-regulation of the insulin-like growth factor receptor 1 (IGF-1R) and mammalian target of rapamycin (mTOR) are of particular importance since they work in concert to facilitate IGF-1R expression and ligand-induced activation, respectively, of proven importance in ES transformation. When used as a single agent in Ewing sarcoma therapy, IGF-1R or mTOR inhibition leads to rapid counter-regulatory effects that blunt the intended therapeutic purpose. Therefore, identify new mechanisms of resistance that are used by Ewing sarcoma to evade cell death to single-agent IGF-1R inhibition might suggest a number of therapeutic combinations that could improve its clinical activity. TC32 and TC71 ES clones with acquired resistance to OSI-906 or NVP-ADW-742 were generated by maintaining the corresponding parental cell lines with increasing concentrations of the agents (up to 2.3 μM for OSI-906, 1.5 μM for NVP-ADW-742) for 7 months. All parental and acquired drug resistant cell lines were tested twice per year for mycoplasma contamination using the MycoAlert Detection Kit (Lonza Group Ltd.) according to the manufacturerâs protocol and validated using short-tandem repeat fingerprinting with an AmpFLSTR Identifier kit as previously described. Herein, we determine subtle differences in acquired mechanism of resistance by two promising small molecule inhibitors of IGF-1R/IR-α. OSI-906, which inhibits IGF-1R and IR, and NVP-ADW-742, which inhibits only IGF-1R, were evaluated using in vitro assays to decipher the mechanism(s) by which IGF-1R inhibition induces drug resistance in Ewing sarcoma cells. The preparation of extracted proteins from sensitive and acquired resistant Ewing sarcoma cells to OSI-906 and NVP-ADW-742 for reverse-phase protein lysate array (RPPA) analysis were prepared using the same array. Lysates were processed, spotted onto nitrocellulose-coated FAST slides, probed with 115 validated primary antibodies, and detected using a DakoCytomation-catalyzed system with secondary antibodies. MicroVigene software program (VigeneTech) was used for automated spot identification, background correction, and individual spot-intensity determination. Expression data was normalized for possible unequal protein loading, taking into account the signal intensity for each sample for all antibodies tested. Log2 values were media-centered by protein to account for variability in signal intensity by time and were calculated using the formula log2 signal â log2 median. Principal component analysis was used to check for a batch effect and feature-by-feature two-sample t-tests were used to assess differences between sensitive and resistant cell lines to drug treatments. We also used feature-by-feature one-way analysis of variance (ANOVA) followed by the Tukey test to perform pair comparisons for all groups. Beta-uniform mixture models were used to fit the resulting p value distributions to adjust for multiple comparisons. The cutoff p values and number of significant proteins were computed for several different false discovery rates (FDRs). Biostatistical analyses comparing two groups were performed using an unpaired t-test with Gaussian distribution followed by the Welch correction. To distinguish between treatment groups, we used one-way ANOVA with the Geisser-Greenhouse correction. Differences with p values <0.05 were considered significant. Within clustered image maps (CIM), unsupervised double hierarchical clustering used the Pearson correlation distance and Wardâs linkage method as the clustering algorithm to link entities (proteins) and samples.