Project description:The inability of the adult human heart to regenerate lost or damaged myocardial tissue has created one of the most pressing public health dilemmas due to the devastating impact of heart failure. Our group and others have outlined several regulators of cardiomyocyte mitosis that may impact the regenerative capacity of the adult myocardium in mammals. Recently, we reported that the transcription factors Meis1 and Hoxb13 regulate postnatal cardiomyocyte cell cycle arrest, where concomitant deletion of both genes induced cardiomyocyte proliferation and myocardial regeneration following ischemic injury. These studies suggest that pharmacological targeting Meis1 and Hoxb13 transcriptional activity could be a viable path towards heart regeneration. Therefore, we performed an in-silico screen to identify FDA-approved drugs that can inhibit Meis1 and Hoxb13 transcriptional activity based on the published crystal structure of Meis1 and Hoxb13 bound to DNA. Our screen yielded several candidates based on binding profiles to either Meis1 DNA binding domain, Hoxb13 DNA binding domain, or the interface between Meis1 and Hoxb13, as well as safety and side effect profiles. Out of the shortlist of top hits, paromomycin and neomycin induced proliferation of neonatal rat ventricular myocytes in vitro and displayed dose-dependent inhibition of Meis1 and Hoxb13 transcriptional activity by luciferase assay, and disruption of DNA binding by EMSA. X-ray crystal structure revealed that both paromomycin and neomycin bind to Meis1 near the Hoxb13 interaction site where they interact with 3 out of the 5 Meis1 amino acids that participate in DNA-binding. The crystal structure also demonstrates that both drugs bind at the interface of Meis1 homodimer, therefore placing one of the Meis1 monomers in a position incompatible with DNA-binding. Importantly, administration of paromomycin-neomycin combination by intraperitoneal injection in mice induced cardiomyocyte proliferation, improved left ventricular (LV) systolic function and decreased scar formation in two models of ischemic reperfusion injury in mice. Finally, dual intravenous administration of the paromomycin-neomycin combination in Yorkshire pigs following cardiac ischemia/reperfusion injury induced cardiomyocyte proliferation, improved LV systolic function, and decreased scar formation. Collectively, we identified paromomycin and neomycin as FDA-approved drugs with therapeutic potential for induction of heart regeneration in humans.
Project description:The inability of the adult human heart to regenerate lost or damaged myocardial tissue has created one of the most pressing public health dilemmas due to the devastating impact of heart failure. Our group and others have outlined several regulators of cardiomyocyte mitosis that may impact the regenerative capacity of the adult myocardium in mammals. Recently, we reported that the transcription factors Meis1 and Hoxb13 regulate postnatal cardiomyocyte cell cycle arrest, where concomitant deletion of both genes induced cardiomyocyte proliferation and myocardial regeneration following ischemic injury. These studies suggest that pharmacological targeting Meis1 and Hoxb13 transcriptional activity could be a viable path towards heart regeneration. Therefore, we performed an in-silico screen to identify FDA-approved drugs that can inhibit Meis1 and Hoxb13 transcriptional activity based on the published crystal structure of Meis1 and Hoxb13 bound to DNA. Our screen yielded several candidates based on binding profiles to either Meis1 DNA binding domain, Hoxb13 DNA binding domain, or the interface between Meis1 and Hoxb13, as well as safety and side effect profiles. Out of the shortlist of top hits, paromomycin and neomycin induced proliferation of neonatal rat ventricular myocytes in vitro and displayed dose-dependent inhibition of Meis1 and Hoxb13 transcriptional activity by luciferase assay, and disruption of DNA binding by EMSA. X-ray crystal structure revealed that both paromomycin and neomycin bind to Meis1 near the Hoxb13 interaction site where they interact with 3 out of the 5 Meis1 amino acids that participate in DNA-binding. The crystal structure also demonstrates that both drugs bind at the interface of Meis1 homodimer, therefore placing one of the Meis1 monomers in a position incompatible with DNA-binding. Importantly, administration of paromomycin-neomycin combination by intraperitoneal injection in mice induced cardiomyocyte proliferation, improved left ventricular (LV) systolic function and decreased scar formation in two models of ischemic reperfusion injury in mice. Finally, dual intravenous administration of the paromomycin-neomycin combination in Yorkshire pigs following cardiac ischemia/reperfusion injury induced cardiomyocyte proliferation, improved LV systolic function, and decreased scar formation. Collectively, we identified paromomycin and neomycin as FDA-approved drugs with therapeutic potential for induction of heart regeneration in humans.
Project description:Targeting Meis1 and Hoxb13 transcriptional activity could be a viable therapeutic strategy for heart regeneration. In this study, we performd an in silico screening to identify FDA-approved drugs that can inhibit Meis1 and Hoxb13 transcriptional activity based on the resolved crystal structure of Meis1 and Hoxb13 bound to DNA. Paromomycin (Paro) and neomycin (Neo) induced proliferation of neonatal rat ventricular myocytes in vitro and displayed dose-dependent inhibition of Meis1 and Hoxb13 transcriptional activity by luciferase assay and disruption of DNA binding by electromobility shift assay. X-ray crystal structure revealed that both Paro and Neo bind to Meis1 near the Hoxb13-interacting domain. Administration of Paro-Neo combination in adult mice and in pigs after cardiac ischemia/reperfusion injury induced cardiomyocyte proliferation, improved left ventricular systolic function and decreased scar formation. Collectively, we identified FDA-approved drugs with therapeutic potential for induction of heart regeneration in mammals.
Project description:Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft tissue sarcomas developed from Schwann cell lineage. They account for up to 10% of all soft tissue sarcomas. Although there is an unmet need for new therapeutic agents for MPNSTs, to date there have been few transcriptomic analyses of this tumor type. We studied FDA approved drugs for MPNST treatment and compared their transcriptomic changes in cell lines before and after treatment. We demonstrated that Fludarabine treated NF1 MPNST cells exhibited altered signaling pathways such as the upregulation of the Wnt/Ca+ pathway and downregulation of the hedgehog and hypoxia signaling pathways in the Ingenuity Pathway Analysis (IPA) and Gene Set Enrichment Analysis (GSEA) analysis. The combined Colchicine and Fludarabine treatment enhanced the cytotoxicity of sporadic MPNST cells through altered signaling pathways, including increased Wnt/β-catenin pathway and others. The transcriptomic analysis comparing NF1/sporadic MPNST cells and normal Schwann cells indicated that NF1 MPNST cells had more splicing events, fewer single nucleotide variants, and induced RNA expression than sporadic MPNST cells. In summary, we identified a transcriptomic differences between MPNSTs and Schwann cells, between sporadic MPNST cells and NF1 MPNST cells, and between drug treated MPNST cells and vehicle treated cells.
Project description:The NLRP3 inflammasome is dysregulated in autoinflammatory disorders caused by inherited mutations and contributes to the pathogenesis of several chronic inflammatory diseases. In this study, we discovered that disulfiram, a safe FDA-approved drug, specifically inhibits the NLRP3 inflammasome, but not the NLRC4 or AIM2 inflammasomes. Disulfiram suppresses caspase-1 activation, ASC speck formation, and pyroptosis induced by several stimuli that activate NLRP3. Mechanistically, NLRP3 is palmitoylated at cysteine 126, a modification required for its localization to the trans-Golgi network and inflammasome activation which was inhibited by disulfiram. Administration of disulfiram to animals inhibited the NLRP3, but not the NLRC4 inflammasome in vivo. Our study uncovers a mechanism by which disulfiram targets NLRP3 and provides a rationale for using a safe FDA-approved drug for the treatment of NLRP3-associated inflammatory diseases.
Project description:Identifying the Mechanism of Action (MoA) of drugs is critical for the development of new drugs, understanding their side effects, and drug repositioning. However, identifying drug MoA has been challenging and has been traditionally attempted only though large experimental setups with little success. While advances in computational power offers the opportunity to achieve this in-silico, methods to exploit existing computational resources are still in their infancy. To overcome this, we developed a novel method to identify Drug Mechanism of Action using Network Dysregulation (DeMAND). The method is based on the realization that drugs affect the protein activity of their targets, but not necessarily their mRNA expression levels. In contrast, the change in protein activity directly affects the mRNA expression levels of downstream genes. Based on this hypothesis, DeMAND identifies drug MoA by comparing gene expression profiles following drug perturbation with control samples, and computing the change in the individual interactions within a pre-determined integrated transcriptional and post-translational regulatory model (interactome). This dataset includes GEPs in 3 different B-cell lymphoma cell lines (OCI-LY3, OCI-LY7 and U2932) at 6, 12, and 24hrs. 92 FDA approved compounds were used at a concentration of IC20 at 24h. DMSO was used as control at each time-point. A total of 828 samples and 29 control samples were available for analysis. Total RNA was isolated with the RNAqueous-96 Automated Kit (Ambion) on the Janus automated liquid handling system (Perkin Elmer Inc.), quantified by NanoDrop 6000 spectrophotometer and quality checked by Agilent Bioanalyzer. 300ng of each of the samples with RIN value >7 were converted to biotinylated cRNA with the Illumina TotalPrep-96 RNA Amplification Kit (Ambion) using a standard T7-based amplification protocol and hybridized on the Human Genome U219 96-Array Plate (Affymetrix). Hybridization, washing, staining and scanning of the array plates were performed on the GeneTitan Instrument (Affymetrix) according to manufacturer’s protocols.