ABSTRACT
Single-cell RNA sequencing (scRNA-seq) enables dissecting cellular heterogeneity in tissues, resulting in numerous biological discoveries. Various computational methods have been devised to delineate cell types by clustering scRNA-seq data, where clusters are often annotated using prior knowledge of marker genes. In addition to identifying pure cell types, several methods have been developed to identify cells undergoing state transitions, which often rely on prior clustering results. The present computational approaches predominantly investigate the local and first-order structures of scRNA-seq data using graph representations, while scRNA-seq data frequently display complex high-dimensional structures. Here, we introduce scGeom, a tool that exploits the multiscale and multidimensional structures in scRNA-seq data by analyzing the geometry and topology through curvature and persistent homology of both cell and gene networks. We demonstrate the utility of these structural features to reflect biological properties and functions in several applications, where we show that curvatures and topological signatures of cell and gene networks can help indicate transition cells and the differentiation potential of cells. We also illustrate that structural characteristics can improve the classification of cell types.
Subject(s)
Algorithms , Single-Cell Analysis , Sequence Analysis, RNA/methods , Single-Cell Analysis/methods , Gene Expression Profiling/methods , Transcriptome , Cluster AnalysisABSTRACT
Rubber (Hevea brasiliensis) is a latex-producing plant that often encounters mechanical wounding, as well as pathogen and pest attacks through wound sites during and after tapping. Terpenoids play an important role in the ecological interactions of many plant species, and their diversity is mainly generated by enzymes known as terpene synthases (TPS). In this study, one cDNA sequence encoding a putative terpene synthase, HbTPS20, was obtained from the bark tissues of H. brasiliensis. The encoded protein contains 610 amino acids with a putative N-terminal plastid transit peptide of approximately 70 residues. It belongs to the TPS-b subfamily. Further phylogenetic analysis showed that HbTPS20 formed a separate branch that diverged from the progenitor of all other potentially functional terpene synthases of the rubber TPS-b subfamily. The truncated HbTPS20 without the signal peptide coding sequence was successfully expressed in E. coli and in vitro enzymatic assays with geranyl diphosphate (GPP) or neryl diphosphate (NPP) as a substrate defined HbTPS20 as an active linalool synthase (HbLIS) with the ability to produce linalool as the principal product. RT-qPCR analysis showed that the highest transcript levels of HbTPS20 were found in barks, and this gene was expressed at 2.26- and 250-fold greater levels in the bark tissues of wounded and MeJA-treated plants, respectively, than in those of the control plants. This indicates that this gene may be involved in the induced stress responses of rubber.
Subject(s)
Hevea , Rubber , Rubber/metabolism , Hevea/genetics , Phylogeny , Plant Bark/metabolism , Escherichia coli , Plant Proteins/metabolism , Gene Expression Regulation, PlantABSTRACT
The identification of agonists of the stimulator of interferon genes (STING) pathway has been an area of intense research due to their potential to enhance innate immune response and tumor immunogenicity in the context of immuno-oncology therapy. Initial efforts to identify STING agonists focused on the modification of 2',3'-cGAMP (1) (an endogenous STING activator ligand) and other closely related cyclic dinucleotides (CDNs). While these efforts have successfully identified novel CDNs that have progressed into the clinic, their utility is currently limited to patients with solid tumors that STING agonists can be delivered to intratumorally. Herein, we report the discovery of a unique class of non-nucleotide small-molecule STING agonists that demonstrate antitumor activity when dosed intratumorally in a syngeneic mouse model.
Subject(s)
Membrane Proteins/agonists , Animals , Crystallography, X-Ray , Cyclic AMP/chemistry , Cyclic AMP/pharmacology , Cyclic GMP/chemistry , Cyclic GMP/pharmacology , Female , Humans , Immunity, Innate/drug effects , Immunotherapy/methods , Membrane Proteins/chemistry , Mice , Mice, Inbred BALB C , Models, Molecular , Neoplasms/immunology , Signal Transduction/drug effects , Small Molecule LibrariesABSTRACT
Inhibition of the bromodomain and extra-terminal (BET) family of adaptor proteins is an attractive strategy for targeting transcriptional regulation of key oncogenes, such as c-MYC. Starting with the screening hit 1, a combination of structure-activity relationship and protein structure-guided drug design led to the discovery of a differently oriented carbazole 9 with favorable binding to the tryptophan, proline, and phenylalanine (WPF) shelf conserved in the BET family. Identification of an additional lipophilic pocket and functional group optimization to optimize pharmacokinetic (PK) properties culminated in the discovery of 18 (BMS-986158) with excellent potency in binding and functional assays. On the basis of its favorable PK profile and robust in vivo activity in a panel of hematologic and solid tumor models, BMS-986158 was selected as a candidate for clinical evaluation.
Subject(s)
Antineoplastic Agents/pharmacology , Carbazoles/pharmacology , Drug Discovery , Phenylalanine/pharmacology , Proline/pharmacology , Tryptophan/pharmacology , Administration, Oral , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/chemistry , Carbazoles/administration & dosage , Carbazoles/chemistry , Cell Cycle Proteins/antagonists & inhibitors , Cell Cycle Proteins/metabolism , Dose-Response Relationship, Drug , Humans , Molecular Structure , Phenylalanine/administration & dosage , Phenylalanine/chemistry , Proline/administration & dosage , Proline/chemistry , Structure-Activity Relationship , Transcription Factors/antagonists & inhibitors , Transcription Factors/metabolism , Tryptophan/administration & dosage , Tryptophan/chemistryABSTRACT
The protein O-mannosyltransferase catalyzes O-mannosylation in the endoplasmic reticulum by transferring mannose to the seryl or threonyl residues of substrate proteins. We previously reported a deletion mutant of O-mannosyltransferase C (ΔpmtC) in Aspergillus nidulans with impaired vegetative growth and sterigmatocystin (ST) production. In this study, we investigated whether osmotic conditions contribute to the developmental processes and ST biosynthesis of the ΔpmtC deletion mutant. We found that hyphal growth and ST production partially improved in the presence of NaCl, KCl or sorbitol as osmotic stabilizers. Conidiation of the ΔpmtC deletion mutant was not restored under osmotic stress conditions when the hogA gene was deleted. The hogA gene encodes a protein required for the cellular response to osmotic pressure. However, the yield of ST and the vegetative growth of the ΔhogA ΔpmtC double deletant was restored by high osmolarity in a HogA-independent manner.
Subject(s)
Aspergillus nidulans , Fungal Proteins , Sterigmatocystin , Aspergillus nidulans/genetics , Aspergillus nidulans/metabolism , Culture Media , Fungal Proteins/genetics , Fungal Proteins/metabolism , Gene Expression Regulation, Fungal , Mutation , Osmotic Pressure , Sterigmatocystin/biosynthesisABSTRACT
A series of tetrahydroisoquinoline-based benzodiazepine dimers were synthesized and tested for in vitro cytotoxicity against a panel of cancer cell lines. Structure-activity relationship investigation of various spacers guided by molecular modeling studies helped to identify compounds with picomolar activity. Payload 17 was conjugated to anti-mesothelin and anti-fucosylated monosialotetrahexosylganglioside (FucGM1) antibodies using lysosome-cleavable valine-citrulline dipeptide linkers via heterogeneous lysine conjugation and bacterial transglutaminase-mediated site-specific conjugation. In vitro, these antibody drug conjugates (ADCs) exhibited significant cytotoxic and target-mediated selectivity on human cancer cell lines. The pharmacokinetics and efficacy of these ADCs were further evaluated in gastric and lung cancer xenograft models in mice. Consistent pharmacokinetic profiles, high target specificity, and robust antitumor activity were observed in these models after a single dose of the ADC-46 (0.02 µmol/kg).
Subject(s)
Antibodies, Monoclonal/chemistry , Antineoplastic Agents/pharmacology , Benzodiazepines/chemistry , Drug Design , Immunoconjugates/pharmacology , Small Cell Lung Carcinoma/drug therapy , Stomach Neoplasms/drug therapy , Tetrahydroisoquinolines/chemistry , Animals , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/metabolism , Antineoplastic Agents/chemistry , Apoptosis , Benzodiazepines/metabolism , Cell Proliferation , Female , G(M1) Ganglioside/analogs & derivatives , G(M1) Ganglioside/immunology , GPI-Linked Proteins/immunology , Humans , Immunoconjugates/chemistry , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Mesothelin , Mice , Mice, SCID , Small Cell Lung Carcinoma/pathology , Stomach Neoplasms/pathology , Structure-Activity Relationship , Tetrahydroisoquinolines/metabolism , Tumor Cells, Cultured , Xenograft Model Antitumor AssaysABSTRACT
Substituted benzyloxy aryl compound 2 was identified as an RORγt agonist. Structure based drug design efforts resulted in a potent and selective tricyclic compound 19 which, when administered orally in an MC38 mouse tumor model, demonstrated a desired pharmacokinetic profile as well as a dose-dependent pharmacodynamic response. However, no perceptible efficacy was observed in this tumor model at the doses investigated.
Subject(s)
Benzyl Compounds/pharmacology , Heterocyclic Compounds/pharmacology , Receptors, Retinoic Acid/agonists , Animals , Benzyl Compounds/chemistry , Dose-Response Relationship, Drug , Female , Heterocyclic Compounds/chemistry , Mice , Mice, Inbred C57BL , Molecular Structure , Structure-Activity Relationship , Retinoic Acid Receptor gammaABSTRACT
Aspergillus nidulans produces sterigmatocystin (ST), a precursor of a carcinogenic secondary metabolite aflatoxin (AF), during its developmental process. ST biosynthesis has been shown to be affected by various regulatory factors. In this study, we investigated the involvement of O-mannosyltransferases (PmtA, PmtB, PmtC), in ST production and morphological development. Deletion of pmtA (ΔpmtA), pmtB (ΔpmtB) or pmtC (ΔpmtC) caused no spore production and a significant decline of vegetative growth. A tremendous decline of ST level was observed in all Δpmt mutants at the third day after inoculation. By extending the growth period, ST production of ΔpmtA and ΔpmtB increased to the wild-type level 7 days after inoculation. On the other hand, ST was not detected from 7- or 14-day cultures in ΔpmtC. Expression levels of aflR gene, an essential regulator of the ST biosynthesis pathway, were also down-regulated in the Δpmt strains. By introducing the aflR overexpression cassette, ST production in the ΔpmtA and ΔpmtB significantly increased to levels comparable to the wild type. However, the presence of the aflR overexpression cassette could not improve ST production in the ΔpmtC mutant. These data suggest that the PMT family is a new endogenous factor that is required for ST biosynthesis in A. nidulans. These findings provide better understanding of the regulatory mechanisms of AF/ST biosynthesis, which can ultimately contribute to our ability to control aflatoxin contamination.
Subject(s)
Aspergillus nidulans/metabolism , Carcinogens/metabolism , Isoenzymes/metabolism , Mannosyltransferases/metabolism , Sterigmatocystin/biosynthesis , Aspergillus nidulans/enzymology , Aspergillus nidulans/genetics , Aspergillus nidulans/growth & development , Gene Deletion , Gene Expression Regulation, Fungal , Gene Knockdown Techniques , Genes, Fungal , Genetic Complementation Test , Isoenzymes/genetics , Mannosyltransferases/genetics , MutationABSTRACT
CONTEXT: Half of children experience wheezing by age 6 years, and optimal strategies for preventing severe exacerbations are not well defined. OBJECTIVE: Synthesize the evidence of the effects of daily inhaled corticosteroids (ICS), intermittent ICS, and montelukast in preventing severe exacerbations among preschool children with recurrent wheeze. DATA SOURCES: Medline (1946, 2/25/15), Embase (1947, 2/25/15), CENTRAL. STUDY SELECTION: Studies were included based on design (randomized controlled trials), population (children ≤6 years with asthma or recurrent wheeze), intervention and comparison (daily ICS vs placebo, intermittent ICS vs placebo, daily ICS vs intermittent ICS, ICS vs montelukast), and outcome (exacerbations necessitating systemic steroids). DATA EXTRACTION: Completed by 2 independent reviewers. RESULTS: Twenty-two studies (N = 4550) were included. Fifteen studies (N = 3278) compared daily ICS with placebo and showed reduced exacerbations with daily medium-dose ICS (risk ratio [RR] 0.70; 95% confidence interval [CI], 0.61-0.79; NNT = 9). Subgroup analysis of children with persistent asthma showed reduced exacerbations with daily ICS compared with placebo (8 studies, N = 2505; RR 0.56; 95% CI, 0.46-0.70; NNT = 11) and daily ICS compared with montelukast (1 study, N = 202; RR 0.59; 95% CI, 0.38-0.92). Subgroup analysis of children with intermittent asthma or viral-triggered wheezing showed reduced exacerbations with preemptive high-dose intermittent ICS compared with placebo (5 studies, N = 422; RR 0.65; 95% CI, 0.51-0.81; NNT = 6). LIMITATIONS: More studies are needed that directly compare these strategies. CONCLUSIONS: There is strong evidence to support daily ICS for preventing exacerbations in preschool children with recurrent wheeze, specifically in children with persistent asthma. For preschool children with intermittent asthma or viral-triggered wheezing, there is strong evidence to support intermittent ICS for preventing exacerbations.
Subject(s)
Anti-Asthmatic Agents/therapeutic use , Asthma/drug therapy , Respiratory Sounds , Secondary Prevention , Asthma/prevention & control , Child, Preschool , Humans , RecurrenceABSTRACT
Previously disclosed dihydropyrazolopyrimidines are potent and selective blockers of I(Kur) current. A potential liability with this chemotype is the formation of a reactive metabolite which demonstrated covalent binding to protein in vitro. When substituted at the 2 or 3 position, this template yielded potent I(Kur) inhibitors, with selectivity over hERG which did not form reactive metabolites. Subsequent optimization for potency and PK properties lead to the discovery of ((S)-5-(methoxymethyl)-7-(1-methyl-1H-indol-2-yl)-2-(trifluoromethyl)-4,7-dihydropyrazolo[1,5-a]pyrimidin-6-yl)((S)-2-(3-methylisoxazol-5-yl)pyrrolidin-1-yl)methanone (13j), with an acceptable PK profile in preclinical species and potent efficacy in the preclinical rabbit atrial effective refractory period (AERP) model.
Subject(s)
Kv1.5 Potassium Channel/antagonists & inhibitors , Pyrazoles/chemical synthesis , Pyrimidines/chemical synthesis , Animals , Dogs , Heart/drug effects , Heart/physiology , Humans , Pyrazoles/pharmacokinetics , Pyrazoles/pharmacology , Pyrimidines/pharmacokinetics , Pyrimidines/pharmacology , Rabbits , Rats , Refractory Period, Electrophysiological/drug effects , Stereoisomerism , Structure-Activity RelationshipABSTRACT
A series of 2,2-dimethyl-3,3-diphenyl-propanamides as novel glucocorticoid receptor modulators is reported. SAR exploration led to the identification of 4-hydroxyphenyl propanamide derivatives displaying good agonist activity in GR-mediated transrepression assays and reduced agonist activity in GR-mediated transactivation assays. Compounds 17 and 30 showed anti-inflammatory activity comparable to prednisolone in the rat carrageenan-induced paw edema model, with markedly decreased side effects with regard to increases in blood glucose and expression of hepatic tyrosine aminotransferase. A hypothetical binding mode accounting for the induction of the functional activity by a 4-hydroxyl group is proposed.
Subject(s)
Amides/pharmacology , Receptors, Glucocorticoid/agonists , Amides/chemistry , Animals , Models, Molecular , RatsABSTRACT
Dihydropyrazolopyrimidines with a C6 heterocycle substituent were found to have high potency for block of K(V)1.5. Investigation of the substitution in the benzimidazole ring and the substituent in the 5-position of the dihydropyrazolopyrimidine ring produced 31a with an IC50 for K(V)1.5 block of 0.030muM without significant block of other cardiac ion channels. This compound also showed good bioavailability in rats and robust pharmacodynamic effects in a rabbit model.
Subject(s)
Kv1.5 Potassium Channel/antagonists & inhibitors , Potassium Channel Blockers/pharmacology , Pyrazoles/pharmacology , Pyrimidines/pharmacology , Animals , Atrial Fibrillation/drug therapy , Cell Line , Humans , Kv1.5 Potassium Channel/metabolism , Mice , Potassium Channel Blockers/chemistry , Potassium Channel Blockers/pharmacokinetics , Pyrazoles/chemistry , Pyrazoles/pharmacokinetics , Pyrimidines/chemistry , Pyrimidines/pharmacokinetics , Rabbits , Rats , Structure-Activity RelationshipABSTRACT
Hit to Lead optimization and SAR development led to the identification of the potent and selective benzo[d]imidazole inhibitor (17b) of Co-activator Associated Arginine Methyltransferase (CARM1).
Subject(s)
Antineoplastic Agents/chemistry , Benzimidazoles/chemistry , Enzyme Inhibitors/chemistry , Piperidines/chemistry , Protein-Arginine N-Methyltransferases/antagonists & inhibitors , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Benzimidazoles/chemical synthesis , Benzimidazoles/pharmacology , Drug Design , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Piperidines/chemical synthesis , Piperidines/pharmacology , Protein-Arginine N-Methyltransferases/metabolism , Structure-Activity RelationshipABSTRACT
Design, synthesis, and SAR development led to the identification of the potent, novel, and selective pyrazole based inhibitor (7f) of Coactivator Associated Arginine Methyltransferase (CARM1).
Subject(s)
Enzyme Inhibitors/chemistry , Protein-Arginine N-Methyltransferases/antagonists & inhibitors , Pyrazoles/chemistry , Drug Design , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Humans , Protein-Arginine N-Methyltransferases/metabolism , Pyrazoles/chemical synthesis , Pyrazoles/pharmacology , Structure-Activity RelationshipABSTRACT
A series of dihydro-9,10-ethano-anthracene-11-carboxamides as novel glucocorticoid receptor modulators is reported. SAR exploration identified compounds from this series displaying a promising dissociation profile in discriminating between transrepression and transactivation activities. 17a is a partial agonist of GR-mediated transactivation which elicits potent and efficacious transrepression in reporter gene assays. A hypothetical binding mode is provided which accounts for the induction of functional activity by a bridgehead methyl group.
Subject(s)
Anthracenes/pharmacology , Drug Discovery , Receptors, Glucocorticoid/metabolism , Anthracenes/chemistry , Cell Line , Crystallography, X-Ray , Drug Discovery/methods , Glucocorticoids/chemistry , Glucocorticoids/pharmacology , Humans , Protein Binding/drug effects , Protein Binding/physiology , Receptors, Glucocorticoid/agonists , Receptors, Glucocorticoid/physiology , Structure-Activity RelationshipABSTRACT
A series of dihydropyrazolopyrimidine inhibitors of K(V)1.5 (I(Kur)) have been identified. The synthesis, structure-activity relationships and selectivity against several other ion channels are described.
Subject(s)
Chemistry, Pharmaceutical/methods , Potassium Channel Blockers/chemical synthesis , Potassium Channels, Voltage-Gated/antagonists & inhibitors , Pyrimidines/chemical synthesis , Pyrimidines/pharmacology , Animals , Atrial Fibrillation/metabolism , Cell Line , Drug Design , Humans , Ions/chemistry , Mice , Models, Chemical , Potassium Channel Blockers/pharmacology , Stereoisomerism , Structure-Activity RelationshipABSTRACT
This study reports the identification and Hits to Leads optimization of inhibitors of coactivator associated arginine methyltransferase (CARM1). Compound 7b is a potent, selective inhibitor of CARM1.
Subject(s)
Protein-Arginine N-Methyltransferases/antagonists & inhibitors , Pyrazoles/chemical synthesis , Pyrazoles/pharmacology , Combinatorial Chemistry Techniques , Molecular Structure , Pyrazoles/chemistry , Stereoisomerism , Structure-Activity RelationshipABSTRACT
An amide library derived from the pyrrolo[2,1-f][1,2,4]triazine scaffold led to the identification of modest inhibitors of Met kinase activity. Introduction of polar side chains at C-6 of the pyrrolotriazine core provided significant improvements in in vitro potency. The amide moiety could be replaced with acylurea and malonamide substituents to give compounds with improved potency in the Met-driven GTL-16 human gastric carcinoma cell line. Acylurea pyrrolotriazines with substitution at C-5 demonstrated single digit nanomolar kinase activity. X-ray crystallography revealed that the C-5 substituted pyrrolotriazines bind to the Met kinase domain in an ATP-competitive manner.
Subject(s)
Enzyme Inhibitors/pharmacology , Proto-Oncogene Proteins/antagonists & inhibitors , Pyrroles/chemistry , Receptor Protein-Tyrosine Kinases/antagonists & inhibitors , Receptors, Growth Factor/antagonists & inhibitors , Stomach Neoplasms/drug therapy , Triazines/chemistry , Animals , Caco-2 Cells/drug effects , Cell Proliferation/drug effects , Cells, Cultured/drug effects , Crystallography, X-Ray , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacokinetics , Ether-A-Go-Go Potassium Channels/antagonists & inhibitors , Glutathione Transferase/antagonists & inhibitors , Hepatocytes/drug effects , Hepatocytes/metabolism , Humans , Mice , Microsomes, Liver/drug effects , Microsomes, Liver/metabolism , Molecular Structure , Protein Conformation , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins c-met , Receptor Protein-Tyrosine Kinases/metabolism , Receptors, Growth Factor/metabolism , Stomach Neoplasms/blood , Stomach Neoplasms/enzymology , Structure-Activity RelationshipABSTRACT
K(V)1.5 blockers have the potential to be atrium-selective agents for treatment of atrial fibrillation. The benzopyrans provide a template for the synthesis of potent and selective K(V)1.5 blockers.
Subject(s)
Atrial Fibrillation/drug therapy , Atrial Function/drug effects , Benzopyrans/pharmacology , Kv1.5 Potassium Channel/drug effects , Potassium Channel Blockers/pharmacology , Sulfonamides/pharmacology , Atrial Function/physiology , Benzopyrans/chemistry , Kv1.5 Potassium Channel/metabolism , Models, Chemical , Potassium Channel Blockers/chemical synthesis , Sulfonamides/chemistryABSTRACT
In a high-throughput screening effort, a series of tetrahydroisoquinolines was identified as modest inhibitors of human Eg5. A medicinal chemistry optimization effort led to the identification of R-4-(3-hydroxyphenyl)-N,N-7,8-tetramethyl-3,4-dihydroisoquinoline-2(1H)-carboxamide (32a) as a potent inhibitor of human Eg5 (ATPase IC50 104 nM) with good anti-proliferative activity in A2780 cells (IC50 234 nM).