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1.
Biogerontology ; 2023 Oct 04.
Article in English | MEDLINE | ID: mdl-37792135

ABSTRACT

Sex is a crucial biological variable, and influence of biological sex on the change of gene expression in ageing skeletal muscle has not yet been fully revealed. In this study, the mRNA expression profiles were obtained from the Gene Expression Omnibus database. Key genes were identified by differential expression analysis and weighted gene co-expression network analysis. The gene set enrichment analysis software and Molecular Signatures Database were used for functional and enrichment analysis. A protein-protein interaction network was constructed using STRING and visualized in Cytoscape. The results were compared between female and male subgroups. Differentially expressed genes and enriched pathways in different sex subgroups shared only limited similarities. The pathways enriched in the female subgroup were more similar to the pathways enriched in the older groups without taking sex difference into consideration. The pathways enriched in the female subgroup were more similar to the pathways enriched in the older groups without taking sex difference into consideration. The muscle myosin filament pathways were downregulated in the both aged female and male samples whereas transforming growth factor beta pathway and extracellular matrix-related pathways were upregulated. With muscle ageing, the metabolism-related pathways, protein synthesis and degradation pathways, results of predicted immune cell infiltration, and gene cluster associated with slow-type myofibers drastically different between the female and male subgroups. This finding may indicate that changes in muscle type with ageing may differ between the sexes in vastus lateralis muscle.

2.
Malar J ; 20(1): 107, 2021 Feb 19.
Article in English | MEDLINE | ID: mdl-33608015

ABSTRACT

BACKGROUND: The ongoing global malaria eradication campaign requires development of potent, safe, and cost-effective drugs lacking cross-resistance with existing chemotherapies. One critical step in drug development is selecting a suitable clinical candidate from late leads. The process used to select the clinical candidate SJ733 from two potent dihydroisoquinolone (DHIQ) late leads, SJ733 and SJ311, based on their physicochemical, pharmacokinetic (PK), and toxicity profiles is described. METHODS: The compounds were tested to define their physicochemical properties including kinetic and thermodynamic solubility, partition coefficient, permeability, ionization constant, and binding to plasma proteins. Metabolic stability was assessed in both microsomes and hepatocytes derived from mice, rats, dogs, and humans. Cytochrome P450 inhibition was assessed using recombinant human cytochrome enzymes. The pharmacokinetic profiles of single intravenous or oral doses were investigated in mice, rats, and dogs. RESULTS: Although both compounds displayed similar physicochemical properties, SJ733 was more permeable but metabolically less stable than SJ311 in vitro. Single dose PK studies of SJ733 in mice, rats, and dogs demonstrated appreciable oral bioavailability (60-100%), whereas SJ311 had lower oral bioavailability (mice 23%, rats 40%) and higher renal clearance (10-30 fold higher than SJ733 in rats and dogs), suggesting less favorable exposure in humans. SJ311 also displayed a narrower range of dose-proportional exposure, with plasma exposure flattening at doses above 200 mg/kg. CONCLUSION: SJ733 was chosen as the candidate based on a more favorable dose proportionality of exposure and stronger expectation of the ability to justify a strong therapeutic index to regulators.


Subject(s)
Antimalarials/pharmacology , Isoquinolines/pharmacology , Animals , Antimalarials/pharmacokinetics , Antimalarials/toxicity , Biological Availability , Dogs , Hepatocytes/drug effects , Heterocyclic Compounds, 4 or More Rings/pharmacokinetics , Heterocyclic Compounds, 4 or More Rings/pharmacology , Heterocyclic Compounds, 4 or More Rings/toxicity , Humans , Isoquinolines/pharmacokinetics , Isoquinolines/toxicity , Mice , Microsomes, Liver/drug effects , Rats
3.
Proc Natl Acad Sci U S A ; 111(50): E5455-62, 2014 Dec 16.
Article in English | MEDLINE | ID: mdl-25453091

ABSTRACT

Drug discovery for malaria has been transformed in the last 5 years by the discovery of many new lead compounds identified by phenotypic screening. The process of developing these compounds as drug leads and studying the cellular responses they induce is revealing new targets that regulate key processes in the Plasmodium parasites that cause malaria. We disclose herein that the clinical candidate (+)-SJ733 acts upon one of these targets, ATP4. ATP4 is thought to be a cation-transporting ATPase responsible for maintaining low intracellular Na(+) levels in the parasite. Treatment of parasitized erythrocytes with (+)-SJ733 in vitro caused a rapid perturbation of Na(+) homeostasis in the parasite. This perturbation was followed by profound physical changes in the infected cells, including increased membrane rigidity and externalization of phosphatidylserine, consistent with eryptosis (erythrocyte suicide) or senescence. These changes are proposed to underpin the rapid (+)-SJ733-induced clearance of parasites seen in vivo. Plasmodium falciparum ATPase 4 (pfatp4) mutations that confer resistance to (+)-SJ733 carry a high fitness cost. The speed with which (+)-SJ733 kills parasites and the high fitness cost associated with resistance-conferring mutations appear to slow and suppress the selection of highly drug-resistant mutants in vivo. Together, our data suggest that inhibitors of PfATP4 have highly attractive features for fast-acting antimalarials to be used in the global eradication campaign.


Subject(s)
Antimalarials/pharmacology , Calcium-Transporting ATPases/metabolism , Heterocyclic Compounds, 4 or More Rings/pharmacology , Isoquinolines/pharmacology , Malaria/drug therapy , Models, Molecular , Plasmodium/drug effects , Antimalarials/pharmacokinetics , Calcium-Transporting ATPases/genetics , Cellular Senescence/drug effects , Drug Discovery , Drug Resistance/genetics , Erythrocytes/drug effects , Flow Cytometry , Heterocyclic Compounds, 4 or More Rings/pharmacokinetics , High-Throughput Screening Assays , Isoquinolines/pharmacokinetics , Molecular Structure
4.
Nature ; 465(7296): 311-5, 2010 May 20.
Article in English | MEDLINE | ID: mdl-20485428

ABSTRACT

Malaria caused by Plasmodium falciparum is a disease that is responsible for 880,000 deaths per year worldwide. Vaccine development has proved difficult and resistance has emerged for most antimalarial drugs. To discover new antimalarial chemotypes, we have used a phenotypic forward chemical genetic approach to assay 309,474 chemicals. Here we disclose structures and biological activity of the entire library-many of which showed potent in vitro activity against drug-resistant P. falciparum strains-and detailed profiling of 172 representative candidates. A reverse chemical genetic study identified 19 new inhibitors of 4 validated drug targets and 15 novel binders among 61 malarial proteins. Phylochemogenetic profiling in several organisms revealed similarities between Toxoplasma gondii and mammalian cell lines and dissimilarities between P. falciparum and related protozoans. One exemplar compound displayed efficacy in a murine model. Our findings provide the scientific community with new starting points for malaria drug discovery.


Subject(s)
Antimalarials/analysis , Antimalarials/pharmacology , Drug Discovery , Plasmodium falciparum/drug effects , Plasmodium falciparum/genetics , Animals , Antimalarials/isolation & purification , Cell Line , Drug Evaluation, Preclinical , Drug Resistance/drug effects , Drug Therapy, Combination , Erythrocytes/drug effects , Erythrocytes/parasitology , Humans , Malaria, Falciparum/drug therapy , Malaria, Falciparum/parasitology , Mice , Phenotype , Phylogeny , Plasmodium falciparum/metabolism , Reproducibility of Results , Small Molecule Libraries/chemistry , Small Molecule Libraries/pharmacology
5.
Pharm Res ; 31(11): 3060-72, 2014 Nov.
Article in English | MEDLINE | ID: mdl-24906597

ABSTRACT

PURPOSE: Retinoblastoma is a childhood cancer of the retina. Clinical trials have shown that local delivery of broad spectrum chemotherapeutic agents is efficacious. Recent studies characterizing the genomic and epigenomic landscape of retinoblastoma identified spleen tyrosine kinase (SYK) as a promising candidate for targeted therapy. The purpose of this study was to conduct preclinical testing of the SYK antagonist R406 to evaluate it as a candidate for retinoblastoma treatment. METHODS: The efficacy of the SYK antagonist R406 delivered locally in a human orthotopic xenograft mouse model of retinoblastoma was tested. Intraocular exposure of R406 was determined for various routes and formulations. RESULTS: There was no evidence of efficacy for subconjunctival. R406. Maximal vitreal concentration was 10-fold lower than the minimal concentration required to kill retinoblastoma cells in vitro. Dosage of R406 subconjunctivally from emulsion or suspension formulations, direct intravitreal injection of the soluble prodrug of R406 (R788), and repeated topical administration of R406 all increased vitreal exposure, but failed to reach the exposure required for retinoblastoma cell death in culture. CONCLUSION: Taken together, these data suggest that R406 is not a viable clinical candidate for the treatment of retinoblastoma. This study highlights the importance of pharmacokinetic testing of molecular targeted retinoblastoma therapeutics.


Subject(s)
Intracellular Signaling Peptides and Proteins/antagonists & inhibitors , Oxazines/pharmacology , Oxazines/pharmacokinetics , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/pharmacokinetics , Protein-Tyrosine Kinases/antagonists & inhibitors , Pyridines/pharmacology , Pyridines/pharmacokinetics , Retinal Neoplasms/drug therapy , Retinoblastoma/drug therapy , Animals , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Cell Death/drug effects , Disease Models, Animal , Eye/drug effects , Female , Humans , Mice , Mice, Inbred C57BL , Syk Kinase
6.
Sci Rep ; 14(1): 7312, 2024 03 27.
Article in English | MEDLINE | ID: mdl-38538650

ABSTRACT

Urinary incontinence is a common disease among middle-aged and elderly women, which not only affects the physical and mental health of patients, but also brings a great medical burden to society. Obesity is a known risk factor for urinary incontinence and is the most common secondary cause of hyperlipidemia. Most obese patients also suffer from hyperlipidemia in the clinic. However, few studies have explored the role of hyperlipidemia in women with urinary incontinence. Using data from the 2005-2018 National Health and Nutrition Examination Survey (NHANES), we aimed to evaluated the independent associations of high body mass index and hyperlipidemia with urinary incontinence in Americans by conducting a weighted multivariate logistic regression model. Additive interactions were also assessed using the relative excess risk due to interaction (RERI), attributed proportion of interaction (AP) and synergy index (S). This study demonstrated that hyperlipidemia was associated with a higher risk of stress urinary incontinence among women with obesity (OR = 1.52, 95% CI = 1.03-2.25), and there was a significant synergistic effect of hyperlipidemia and obesity on stress urinary incontinence(adjusted RERI: 3.75, 95% CI 0.30-7.20; adjusted AP: 0.67, 95% CI 0.54-0.80; adjusted S: 5.49, 95% CI 4.15-7.27). Moreover, fasting serum triglyceride lipids were the most relevant blood lipid indicator for the risk of stress urinary incontinence, especially among obese women younger than 50 years old, which contributes to the development of more refined lipid control protocols for patients with urinary incontinence in different age groups.


Subject(s)
Hyperlipidemias , Urinary Incontinence, Stress , Urinary Incontinence , Aged , Middle Aged , Humans , Female , United States/epidemiology , Urinary Incontinence, Stress/etiology , Nutrition Surveys , Hyperlipidemias/complications , Risk Factors , Obesity/complications , Urinary Incontinence/etiology , Urinary Incontinence/complications , Lipids
7.
J Med Chem ; 67(5): 3437-3447, 2024 Mar 14.
Article in English | MEDLINE | ID: mdl-38363074

ABSTRACT

Human African trypanosomiasis (HAT), a neglected tropical disease caused by Trypanosoma brucei gambiense (Tbg) or Trypanosoma brucei rhodesiense (Tbr), remains a significant public health concern with over 55 million people at risk of infection. Current treatments for HAT face the challenges of poor efficacy, drug resistance, and toxicity. This study presents the synthesis and evaluation of chloronitrobenzamides (CNBs) against Trypanosoma species, identifying previously reported compound 52 as a potent and selective orally bioavailable antitrypanosomal agent. 52 was well tolerated in vivo and demonstrated favorable oral pharmacokinetics, maintaining plasma concentrations surpassing the cellular EC50 for over 24 h and achieving peak brain concentrations exceeding 7 µM in rodents after single oral administration (50 mg/kg). Treatment with 52 significantly extended the lifespan of mice infected with Trypanosoma congolense and T. brucei rhodesiense. These results demonstrate that 52 is a strong antitrypanosomal lead with potential for developing treatments for both human and animal African trypanosomiasis.


Subject(s)
Trypanocidal Agents , Trypanosoma brucei brucei , Trypanosomiasis, African , Humans , Animals , Mice , Trypanosomiasis, African/drug therapy , Trypanosoma brucei rhodesiense , Trypanosoma brucei gambiense , Trypanocidal Agents/toxicity , Trypanocidal Agents/therapeutic use
8.
Sci Immunol ; 9(95): eadk0865, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38701189

ABSTRACT

Dysregulated B cell cytokine production contributes to pathogenesis of immune-mediated diseases including multiple sclerosis (MS); however, the underlying mechanisms are poorly understood. In this study we investigated how cytokine secretion by pro-inflammatory (GM-CSF-expressing) and anti-inflammatory (IL-10-expressing) B cells is regulated. Pro-inflammatory human B cells required increased oxidative phosphorylation (OXPHOS) compared with anti-inflammatory B cells. OXPHOS reciprocally modulated pro- and anti-inflammatory B cell cytokines through regulation of adenosine triphosphate (ATP) signaling. Partial inhibition of OXPHOS or ATP-signaling including with BTK inhibition resulted in an anti-inflammatory B cell cytokine shift, reversed the B cell cytokine imbalance in patients with MS, and ameliorated neuroinflammation in a myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalitis mouse model. Our study identifies how pro- and anti-inflammatory cytokines are metabolically regulated in B cells and identifies ATP and its metabolites as a "fourth signal" that shapes B cell responses and is a potential target for restoring the B cell cytokine balance in autoimmune diseases.


Subject(s)
B-Lymphocytes , Cytokines , Encephalomyelitis, Autoimmune, Experimental , Inflammation , Multiple Sclerosis , Oxidative Phosphorylation , Animals , Multiple Sclerosis/immunology , Humans , Cytokines/immunology , Cytokines/metabolism , Mice , B-Lymphocytes/immunology , Encephalomyelitis, Autoimmune, Experimental/immunology , Inflammation/immunology , Female , Male , Mice, Inbred C57BL , Adult , Adenosine Triphosphate/metabolism , Middle Aged
9.
Bioorg Med Chem Lett ; 23(14): 4127-31, 2013 Jul 15.
Article in English | MEDLINE | ID: mdl-23746473

ABSTRACT

We previously reported the phenylchloronitrobenzamides (PCNBs), a novel class of compounds active against the species of trypanosomes that cause Human African Trypanosomiasis (HAT). Herein, we explored the potential to adjust the reactivity of the electrophilic chloronitrobenzamide core. These studies identified compound 7d that potently inhibited the growth of trypanosomes (EC50=120nM for Trypanosoma b. brucei, 18nM for Trypanosoma b. rhodesiense, and 38nM for Trypanosoma b. gambiense) without significant cytotoxicity against mammalian cell lines (EC50>25µM for HepG2, HEK293, Raji, and BJ cell lines) and also had good stability in microsomal models (t1/2>4h in both human and mouse). Overall these properties indicate the compound 7d and its analogs are worth further exploration as potential leads for HAT.


Subject(s)
Benzamides/chemistry , Trypanocidal Agents/chemistry , Trypanosoma brucei brucei/drug effects , Animals , Benzamides/chemical synthesis , Benzamides/toxicity , Cell Line , Hep G2 Cells , Humans , Mice , Microsomes/metabolism , Solubility , Trypanocidal Agents/chemical synthesis , Trypanocidal Agents/toxicity
10.
Sci Rep ; 13(1): 13656, 2023 08 22.
Article in English | MEDLINE | ID: mdl-37608070

ABSTRACT

Urogenital congenital anomalies (UCAs) is defined as "any live-birth with a urinary or genital condition" and affects millions of men and women worldwide. However, sex differences and related environmental risk factors in UCAs burden on a global scale have not been assessed. Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we estimated prevalence, incidence, mortality and disability-adjusted life years (DALYs) of UCAs from 1990 to 2019 by sex, region, and socio-demographic Index (SDI) in 204 countries and territories. The disease burden of UCAs was also estimated attributable to each risk factor were estimated according to risk exposure. In 2019, UCAs caused 10,200 all-ages deaths (95% UI 7550-13,400). The combined global incidence rate was 8.38 per 1000 (95% UI 5.88-12.0) live births. The ASIR increased slightly, while the ASDR decreased from 1990 to 2019.The UCAs burden varies greatly depending on the development level and geographical location. The UCAs burden was significantly higher in men than in women, and the sex differences showed an enlarging trend. Health risks and issues, including pollution, child and maternal malnutrition, diet habits, unsafe sanitation and water source, were detected to be positively related to UCAs burden. Albeit the age-standardised prevalence, mortality, incidence, and DALYs of UCAs have decreased, they still cause a public health challenge worldwide. The high deaths and DALYs rates in low and low-middle SDI countries highlight the urgent need for improved preventive, diagnostic, and therapeutic measures. Global strategies for enhancing water safety, reducing pollution, and healthy diets are crucial steps in reducing the burden of UCAs.


Subject(s)
Urinary Tract , Urogenital Abnormalities , Child , Pregnancy , Female , Humans , Male , Sex Characteristics , Risk Factors , Cost of Illness
11.
Int Immunopharmacol ; 123: 110748, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37531831

ABSTRACT

Acupuncture at ST36 can alleviate a variety of autoimmune diseases, including experimental autoimmune encephalomyelitis (EAE), while the specific mechanism for the treatment of EAE is not clear. In this study, we found that acupuncture at ST36 can significantly increase the excitability of splenic sympathetic nerve, and promote the differentiation of peripheral B and CD4+T cells in the anti-inflammatory direction. After blocking the splenic sympathetic nerve with 6-OHDA, this anti-inflammatory effect of acupuncture is partially reversed. In addition, the results of western blot and qPCR showed that acupuncture at ST36 simultaneously activated the ß2-AR-cAMP signaling pathway in the splenic B and CD4+T cells, and this activation was more significant in B cells. In vitro, when CD4+T cells were cultured alone, norepinephrine (NE) had no significant effect on their differentiation. While in the presence of B cells, NE significantly promotes the anti-inflammatory differentiation of B and CD4+T cells. Therefore, the above results reveal that acupuncture can relieve EAE by stimulating the sympathetic nerves of spleen, mainly through acting on B cells to mediate anti-inflammatory effects, and indirectly affecting the function of CD4+T cells.


Subject(s)
Acupuncture Therapy , Encephalomyelitis, Autoimmune, Experimental , Animals , Mice , T-Lymphocytes , Signal Transduction , Anti-Inflammatory Agents/therapeutic use , Mice, Inbred C57BL
12.
J Biol Chem ; 286(14): 11895-908, 2011 Apr 08.
Article in English | MEDLINE | ID: mdl-21321127

ABSTRACT

Thyroid hormone receptors (TRs) are members of the nuclear hormone receptor (NR) superfamily and regulate development, growth, and metabolism. Upon binding thyroid hormone, TR undergoes a conformational change that allows the release of corepressors and the recruitment of coactivators, which in turn regulate target gene transcription. Although a number of TR antagonists have been developed, most are analogs of the endogenous hormone that inhibit ligand binding. In a screen for inhibitors that block the association of TRß with steroid receptor coactivator 2 (SRC2), we identified a novel methylsulfonylnitrobenzoate (MSNB)-containing series that blocks this interaction at micromolar concentrations. Here we have studied a series of MSNB analogs and characterized their structure activity relationships. MSNB members do not displace thyroid hormone T3 but instead act by direct displacement of SRC2. MSNB series members are selective for the TR over the androgen, vitamin D, and PPARγ NR members, and they antagonize thyroid hormone-activated transcription action in cells. The methylsulfonylnitro group is essential for TRß antagonism. Side-chain alkylamine substituents showed better inhibitory activity than arylamine substituents. Mass spectrum analysis suggested that MSNB inhibitors bind irreversibly to Cys-298 within the AF-2 cleft of TRß to disrupt SRC2 association.


Subject(s)
Nitrobenzoates/pharmacology , Nuclear Receptor Coactivator 2/metabolism , Receptors, Thyroid Hormone/metabolism , Aniline Compounds/pharmacology , HEK293 Cells , Hep G2 Cells , Humans , Methylamines/pharmacology , Nitrobenzoates/chemistry , Piperidines/pharmacology , Protein Binding/drug effects , Reverse Transcriptase Polymerase Chain Reaction , Structure-Activity Relationship
13.
Am J Chin Med ; 50(3): 639-652, 2022.
Article in English | MEDLINE | ID: mdl-35282807

ABSTRACT

Autoimmune diseases (AIDs) are conditions arising from abnormal immune reactions to autoantigens, which can be defined as the loss of immune tolerance to autoantigens, causing the production of autoantibodies and subsequent inflammation and tissue injury. The etiology of AIDs remains elusive, which may involve both genetic and environmental factors, such as diet, drugs, and infections. Despite rapid progress in the treatment of autoimmune diseases over the past few decades, there is still no approach that can cure AIDs. As an alternative approach, traditional Chinese medicine (TCM) such as acupuncture has been used in an attempt to treat AIDs including multiple sclerosis (MS), rheumatoid arthritis (RA), and inflammatory bowel disease (IBD), and the results have proven to be quite promising, despite the fact that its mechanism is still not fully understood. In this review, the present knowledge regarding mechanisms of acupuncture in the treatment of AIDs has been summarized, and deeper insights will be provided in order to better understand how acupuncture may regulate immune responses during AIDs.


Subject(s)
Acquired Immunodeficiency Syndrome , Acupuncture Therapy , Arthritis, Rheumatoid , Autoimmune Diseases , Acquired Immunodeficiency Syndrome/complications , Acupuncture Therapy/methods , Arthritis, Rheumatoid/therapy , Autoantigens , Autoimmune Diseases/therapy , Humans
14.
Pain Ther ; 11(4): 1095-1112, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35922617

ABSTRACT

INTRODUCTION: Acupuncture has gradually penetrated into many disciplines in clinical medicine, such as surgery, anesthesia, and outpatient examinations. Although a number of clinical trials have investigated the effects of acupuncture on colonoscopy, the results were inconsistent. In this meta-analysis, we analyzed the effects of acupuncture on colonoscopy to provide evidence for subsequent research and clinical application of acupuncture in colonoscopy. METHODS: This meta-analysis was performed using Review Manager version 5.4 and Stata version 16 software. The primary outcome was the incidence of adverse events, and the secondary outcomes included patients' anxiety score before colonoscopy, time to insert the colonoscope, total detection time, propofol consumption, patients' pain score, and patient satisfaction rate. RESULTS: The results showed that the incidence of adverse events (odds ratio [OR] 0.27, 95% confidence interval [CI] 0.16-0.43, P = 0.00, I2 = 25%), patients' pain score (mean difference [MD] - 1.03, 95% CI - 1.45 to - 0.62, P = 0.00, I2 = 94%), and time to insert the colonoscope (MD = - 2.54, 95% CI - 4.96 to - 0.13, P = 0.04, I2 = 0%) were significantly lower in the treatment group than in the control group. Compared with the control group, the satisfaction rate of patients (OR 2.53, 95% CI 1.56-4.10, P = 0.00, I2 = 47%) in the treatment group was significantly improved. There was no significant between-group difference in patients' anxiety score, the total detection time, and propofol dosage. CONCLUSIONS: During colonoscopy, acupuncture can significantly reduce the incidence of adverse events, relieve patients' pain, and improve patient satisfaction. REGISTRATION: PROSPERO registration number CRD42022324428.

15.
J Biol Chem ; 285(14): 10786-96, 2010 Apr 02.
Article in English | MEDLINE | ID: mdl-20080970

ABSTRACT

The p53 pathway is disrupted in virtually every human tumor. In approximately 50% of human cancers, the p53 gene is mutated, and in the remaining cancers, the pathway is dysregulated by genetic lesions in other genes that modulate the p53 pathway. One common mechanism for inactivation of the p53 pathway in tumors that express wild-type p53 is increased expression of MDM2 or MDMX. MDM2 and MDMX bind p53 and inhibit its function by distinct nonredundant mechanisms. Small molecule inhibitors and small peptides have been developed that bind MDM2 in the p53-binding pocket and displace the p53 protein, leading to p53-mediated cell cycle exit and apoptosis. To date, peptide inhibitors of MDMX have been developed, but no small molecule inhibitors have been reported. We have developed biochemical and cell-based assays for high throughput screening of chemical libraries to identify MDMX inhibitors and identified the first MDMX inhibitor SJ-172550. This compound binds reversibly to MDMX and effectively kills retinoblastoma cells in which the expression of MDMX is amplified. The effect of SJ-172550 is additive when combined with an MDM2 inhibitor. Results from a series of biochemical and structural modeling studies suggest that SJ-172550 binds the p53-binding pocket of MDMX, thereby displacing p53. This lead compound is a useful chemical scaffold for further optimization of MDMX inhibitors that may eventually be used to treat pediatric cancers and various adult tumors that overexpress MDMX or have similar genetic lesions. When combined with selective MDM2 inhibitors, SJ-172550 may also be useful for treating tumors that express wild-type p53.


Subject(s)
Acetates/pharmacology , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Proto-Oncogene Proteins c-mdm2/antagonists & inhibitors , Proto-Oncogene Proteins c-mdm2/metabolism , Pyrazoles/pharmacology , Retinoblastoma/drug therapy , Retinoblastoma/pathology , Animals , Cell Line, Tumor , Computer Simulation , High-Throughput Screening Assays , Humans , Mice , Retinoblastoma/metabolism , Small Molecule Libraries , Tumor Suppressor Protein p53/antagonists & inhibitors , Tumor Suppressor Protein p53/metabolism
16.
Drug Metab Dispos ; 39(1): 15-21, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20947617

ABSTRACT

Nutlin-3a is an MDM2 inhibitor that is under investigation in preclinical models for a variety of pediatric malignancies, including retinoblastoma, rhabdomyosarcoma, neuroblastoma, and leukemia. We used physiologically based pharmacokinetic (PBPK) modeling to characterize the disposition of nutlin-3a in the mouse. Plasma protein binding and blood partitioning were assessed by in vitro studies. After intravenous (10 and 20 mg/kg) and oral (50, 100, and 200 mg/kg) dosing, tissue concentrations of nutlin-3a were determined in plasma, liver, spleen, intestine, muscle, lung, adipose, bone marrow, adrenal gland, brain, retina, and vitreous fluid. The PBPK model was simultaneously fit to all pharmacokinetic data using NONMEM. Nutlin-3a exhibited nonlinear binding to murine plasma proteins, with the unbound fraction ranging from 0.7 to 11.8%. Nutlin-3a disposition was characterized by rapid absorption with peak plasma concentrations at approximately 2 h and biphasic elimination consistent with a saturable clearance process. The final PBPK model successfully described the plasma and tissue disposition of nutlin-3a. Simulations suggested high bioavailability, rapid attainment of steady state, and little accumulation when administered once or twice daily at dosages up to 400 mg/kg. The final model was used to perform simulations of unbound tissue concentrations to determine which dosing regimens are appropriate for preclinical models of several pediatric malignancies.


Subject(s)
Imidazoles/administration & dosage , Imidazoles/pharmacokinetics , Piperazines/administration & dosage , Piperazines/pharmacokinetics , Administration, Oral , Animals , Biological Availability , Blood Proteins/metabolism , Dose-Response Relationship, Drug , Drug Evaluation, Preclinical , Female , Imidazoles/blood , Imidazoles/pharmacology , Injections, Intravenous , Male , Mice , Mice, Inbred C57BL , Piperazines/blood , Piperazines/pharmacology , Protein Binding , Proto-Oncogene Proteins c-mdm2/antagonists & inhibitors , Tissue Distribution
17.
Bioorg Med Chem Lett ; 20(1): 149-52, 2010 Jan 01.
Article in English | MEDLINE | ID: mdl-19963377

ABSTRACT

A series of halo-nitrobenzamide were synthesized and evaluated for their ability to block proliferation of Trypanosoma brucei brucei. A number of these compounds had significant activity against the parasite, particularly 2-chloro-N-(4-chlorophenyl)-5-nitrobenzamide 17 which exhibited low micromolar inhibitory potency against T. brucei and selectivity towards both malaria and mammalian cells.


Subject(s)
Benzamides/chemistry , Trypanocidal Agents/chemistry , Benzamides/chemical synthesis , Benzamides/pharmacology , Drug Discovery , Humans , Parasitic Sensitivity Tests , Trypanocidal Agents/chemical synthesis , Trypanocidal Agents/pharmacology , Trypanosoma brucei brucei/drug effects , Trypanosomiasis, African/drug therapy
18.
Bioorg Med Chem Lett ; 20(5): 1787-91, 2010 Mar 01.
Article in English | MEDLINE | ID: mdl-20129783

ABSTRACT

In an effort to discover novel anti-trypanosomal compounds, a series of podophyllotoxin analogues coupled to non-steroidal anti-inflammatory drugs (NSAIDs) has been synthesized and evaluated for activity versus Trypanosoma brucei and a panel of human cell lines, revealing compounds with low nano-molar potencies. It was discovered that coupling of NSAIDs to podophyllotoxin increased the potencies of both compounds over 1300-fold. The compounds were shown to be cytostatic in nature and seem to act via de-polymerization of tubulin in a manner consistent with the known activities of podophyllotoxin. The potencies against T. brucei correlated directly with LogP values of the compounds, suggesting that the conjugates are acting as hydrophobic tags allowing podophyllotoxin to enter the cell.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/chemistry , Podophyllotoxin/analogs & derivatives , Trypanocidal Agents/chemistry , Trypanosoma brucei brucei/drug effects , Anti-Inflammatory Agents, Non-Steroidal/chemical synthesis , Anti-Inflammatory Agents, Non-Steroidal/toxicity , Cell Line , Humans , Indomethacin/chemistry , Indomethacin/toxicity , Podophyllotoxin/chemistry , Podophyllotoxin/toxicity , Trypanocidal Agents/chemical synthesis , Trypanocidal Agents/toxicity
19.
Bioorg Med Chem ; 18(23): 8302-9, 2010 Dec 01.
Article in English | MEDLINE | ID: mdl-21051236

ABSTRACT

There are currently only four clinical drugs available for treating human African trypanosomiasis (HAT), three of which were developed over 60 years ago. Despite years of effort, there has been relatively little progress towards identifying orally available chemotypes active against the parasite in vivo. Here, we report the lead optimization of a purine-nitrile scaffold that inhibits the essential TbcatB protease and its evaluation in murine models. A lead inhibitor that had potent activity against the trypanosomal protease TbcatB in vitro and cultured parasites ex vivo was optimized by rationally driven medicinal chemistry to an inhibitor that is orally available, penetrates the CNS, has a promising pharmacokinetic profile, and is non-toxic at 200mg/kg in a repeat dosage study. Efficacy models using oral administration of this lead inhibitor showed a significantly increased survival time in Trypanosoma brucei brucei infected mice but little effect on Trypanosoma brucei rhodesiense infected mice.


Subject(s)
Cysteine Endopeptidases/chemistry , Nitriles/chemistry , Protease Inhibitors/chemistry , Purines/chemistry , Trypanocidal Agents/chemistry , Administration, Oral , Animals , Cysteine Endopeptidases/metabolism , Disease Models, Animal , Humans , Mice , Protease Inhibitors/pharmacokinetics , Protease Inhibitors/therapeutic use , Trypanocidal Agents/pharmacokinetics , Trypanocidal Agents/therapeutic use , Trypanosoma brucei brucei/drug effects , Trypanosoma brucei brucei/enzymology , Trypanosomiasis, African/drug therapy
20.
Bioorg Med Chem ; 18(7): 2756-66, 2010 Apr 01.
Article in English | MEDLINE | ID: mdl-20206533

ABSTRACT

Malaria is endemic in tropical and subtropical regions of Africa, Asia, and the Americas. The increasing prevalence of multi-drug-resistant Plasmodium falciparum drives the ongoing need for the development of new antimalarial drugs. In this light, novel scaffolds to which the parasite has not been exposed are of particular interest. Recently, workers at the Swiss Tropical Institute discovered two novel 4-oxo-3-carboxyl quinolones active against the intra-erythrocytic stages of P. falciparum while carrying out rationally directed low-throughput screening of potential antimalarial agents as part of an effort directed by the World Health Organization. Here we report the design, synthesis, and preliminary pharmacologic characterization of a series of analogues of 4-oxo-3-carboxyl quinolones. These studies indicate that the series has good potential for preclinical development.


Subject(s)
Antimalarials/chemical synthesis , Antimalarials/pharmacology , Quinolones/chemical synthesis , Quinolones/pharmacology , Animals , Antimalarials/toxicity , Cell Line , Cell Survival/drug effects , Drug Resistance , Erythrocytes/parasitology , Escherichia coli/drug effects , Humans , Indicators and Reagents , Mefloquine/pharmacology , Membranes, Artificial , Permeability , Plasmodium falciparum/drug effects , Quinolones/toxicity , Solubility , Structure-Activity Relationship
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