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1.
Mol Pharm ; 21(3): 1170-1181, 2024 Mar 04.
Article in English | MEDLINE | ID: mdl-38329909

ABSTRACT

To improve the oral absorption and anticancer efficacy of the BCS-IV drug etoposide (ETO), oral nanocrystal-loaded lipid carriers (Lipo@NCs) were developed in this study by modifying the BCS-IV drug nanocrystal with the lipid bilayer. The ETO-Lipo@NCs were prepared by the thin film hydration high-pressure homogenization method, and the core of positively charged ETO nanocrystals was prepared by the sonoprecipitation-high pressure homogenization method. The optimized ETO-Lipo@NCs were spherical particles with an average particle size of 220.3 ± 14.2 nm and a zeta potential of -9.95 ± 0.81 mV, respectively. The successful coating of a lipid bilayer on the surface of nanocrystals in ETO-Lipo@NCs was confirmed by several characterization methods. Compared to nanocrystals, the release rate and degree of Lipo@NCs in SIF were significantly decreased, indicating that the lipid bilayer can effectively prevent the rapid dissolution of core nanocrystals. ETO-Lipo@NCs demonstrated a significant improvement in the intestinal permeability and absorption of ETO in a single intestinal perfusion experiment. In the cells, ETO-Lipo@NCs showed enhanced cellular uptake and transepithelial transport compared with ETO nanocrystals. Pharmacokinetic analysis indicated that ETO-Lipo@NCs had a longer plasma half-life than ETO solution, and the oral bioavailability of ETO-Lipo@NCs was 1.96- and 10.92-fold higher than that of ETO nanocrystals and ETO coarse crystals, respectively. Moreover, the ETO-Lipo@NCs orally dosed at 10 mg/kg exhibited an excellent inhibitory effect against tumors in a subcutaneous Lewis lung carcinoma (LLC) xenograft model compared with other preparations. These results indicate that the Lipo@NCs formulation has an oral absorption-promoting effect of the BCS-IV drug ETO, which could warrant further application in the oral delivery of other poorly bioavailable drugs.


Subject(s)
Lipid Bilayers , Nanoparticles , Rats , Animals , Humans , Etoposide , Rats, Sprague-Dawley , Administration, Oral , Solubility , Nanoparticles/chemistry , Particle Size , Biological Availability
2.
Mol Cell ; 58(5): 794-803, 2015 Jun 04.
Article in English | MEDLINE | ID: mdl-25982117

ABSTRACT

G protein-coupled receptors (GPCRs) comprise the largest family of cell surface receptors, regulate a wide range of physiological processes, and are the major targets of pharmaceutical drugs. Canonical signaling from GPCRs is relayed to intracellular effector proteins by trimeric G proteins, composed of α, ß, and γ subunits (Gαßγ). Here, we report that G protein ß subunits (Gß) bind to DDB1 and that Gß2 targets GRK2 for ubiquitylation by the DDB1-CUL4A-ROC1 ubiquitin ligase. Activation of GPCR results in PKA-mediated phosphorylation of DDB1 at Ser645 and its dissociation from Gß2, leading to increase of GRK2 protein. Deletion of Cul4a results in cardiac hypertrophy in male mice that can be partially rescued by the deletion of one Grk2 allele. These results reveal a non-canonical function of the Gß protein as a ubiquitin ligase component and a mechanism of feedback regulation of GPCR signaling.


Subject(s)
G-Protein-Coupled Receptor Kinase 2/metabolism , GTP-Binding Protein beta Subunits/physiology , Nuclear Proteins/metabolism , Ubiquitin-Protein Ligases/metabolism , Ubiquitination , Animals , DNA-Binding Proteins/metabolism , Female , HEK293 Cells , Humans , Male , Mice, Knockout , Protein Stability , Proteolysis , Rats , Rats, Wistar , Signal Transduction
3.
J Am Chem Soc ; 144(49): 22622-22632, 2022 12 14.
Article in English | MEDLINE | ID: mdl-36448571

ABSTRACT

Proteolysis Targeting Chimeras (PROTACs) are attractive therapeutic modalities for degrading disease-causing proteins. While many PROTACs have been developed for numerous protein targets, current small-molecule PROTAC approaches cannot target undruggable proteins that do not have small-molecule binders. Here, we present a novel PROTAC approach, termed bridged PROTAC, which utilizes a small-molecule binder of the target protein's binding partner to recruit the protein complex into close proximity with an E3 ubiquitin ligase to target undruggable proteins. Applying this bridged PROTAC strategy, we discovered MS28, the first-in-class degrader of cyclin D1, which lacks a small-molecule binder. MS28 effectively degrades cyclin D1, with faster degradation kinetics and superior degradation efficiency than CDK4/6, through recruiting the CDK4/6-cyclin D1 complex to the von Hippel-Lindau E3 ligase. MS28 also suppressed the proliferation of cancer cells more effectively than CDK4/6 inhibitors and degraders. Altogether, the bridged PROTAC strategy could provide a generalizable platform for targeting undruggable proteins.


Subject(s)
Cyclin D1 , Proteolysis Targeting Chimera , Proteolysis , Cyclin D1/metabolism , Ubiquitin-Protein Ligases/metabolism , Proteins/metabolism
4.
Drugs R D ; 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38949758

ABSTRACT

BACKGROUND: Vupanorsen is a GalNAc3-conjugated antisense oligonucleotide targeting angiopoietin-like 3 (ANGPTL3) mRNA shown to reduce atherogenic lipoproteins in individuals with dyslipidemia. OBJECTIVES: The aim of this study was to satisfy Chinese regulatory requirements and support ethnic sensitivity assessment by evaluating pharmacokinetics (PK), pharmacodynamics (PD), and safety of vupanorsen in healthy Chinese adults with elevated triglycerides (TG). METHODS: In this phase I, parallel-cohort, open-label study, 18 Chinese adults with elevated fasting TG (≥ 90 mg/dL) were randomized 1:1 to receive a single subcutaneous dose of vupanorsen 80 mg or 160 mg. PK parameters, PD markers (including ANGPTL3, TG, non-high-density lipoprotein cholesterol [non-HDL-C]), and safety were assessed. RESULTS: Absorption of vupanorsen was rapid (median time to maximum concentration [Tmax]: 2.0 h for both doses), followed by a multiphasic decline (mean terminal half-life 475.9 [80 mg] and 465.2 h [160 mg]). Exposure (area under curve [AUC] and maximum plasma concentration [Cmax]) generally increased in a greater than dose-proportional manner from 80 mg to 160 mg. Time-dependent reductions in ANGPTL3 and lipid parameters were observed. Mean percentage change from baseline for the 80-mg and 160-mg doses, respectively, were - 59.7% and - 69.5% for ANGPTL3, - 41.9% and - 52.5% for TG, and - 23.2% and - 25.4% for non-HDL-C. No serious or severe adverse events (AEs), deaths, or discontinuations due to AEs were reported. Three participants experienced treatment-related AEs; all were mild and resolved by end of study. CONCLUSIONS: This study provided the first clinical vupanorsen data in China. In Chinese participants with elevated TG, PK and PD parameters were consistent with those reported previously in non-Chinese participants, including in Japanese individuals. No safety concerns were noted. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT04916795.

5.
ISA Trans ; 129(Pt B): 73-87, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35248369

ABSTRACT

The design of robust state- and output-feedback control for uncertain discrete-time systems with physical magnitude and rate constraints on their actuator dynamics was addressed. Unlike the traditional methods such as anti-windup (AW) methods, nested ellipsoids, model predictive controllers (MPCs) and integral quadratic constraints(IQCs) formulated by sector bounded inequalities, this paper uses a transformation of the system dynamics to a form which considers control signal and its rate as controlled outputs and using discrete-time ℓ∞ induced (peak-to-peak) norm from disturbance inputs to these outputs. To cope with the magnitude and rate bound non-linearities together, the induced ℓ∞ norm from disturbance input to the outputs involving control signal and its rate is utilised. On the other hand, discrete-time(DT) induced ℓ2 norm from disturbance input to the main controlled output is used to mitigate the effects of disturbances. We can tackle this ambitious non-linear control problem in the domain of linear convex multi-objective optimal control problem, which can be solved by effective semi-definite optimisation methods by using the proposed transformation and handling the control constraints in terms of worst case peak-to-peak gain of the system. Extended Linear Matrix Inequalities (LMIs) and full block S-procedure based design conditions developed over Linear Fractional Representation(LFR) framework allow the user to obtain robust state- and output-feedback control solutions with reduced conservatism. For the first time, this paper introduces an extended LMI based robust output-feedback control design for magnitude and rate bounded (MRB) systems, using full block S-procedure. We demonstrate the performance of the proposed controller through several simulations over benchmark examples covering systems having multi-variable structures and uncertainties. Our study also involves comparison results with a recently introduced technique based on multi-stage AW technique. The simulation results show that the proposed method of this paper is much effective and less conservative compared to the recent AW method provided in the literature.

6.
Oncogene ; 41(40): 4547-4559, 2022 09.
Article in English | MEDLINE | ID: mdl-36064579

ABSTRACT

Anaplastic lymphoma kinase (ALK), a receptor tyrosine kinase of the insulin receptor kinase subfamily, is activated in multiple cancer types through translocation or overexpression. Although several generations of ALK tyrosine kinase inhibitors (TKIs) have been developed for clinic use, drug resistance remains a major challenge. In this study, by quantitative proteomic approach, we identified the glycolytic regulatory enzyme, 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), as a new target of ALK. Expression of PFKFB3 is highly dependent on ALK activity in ALK+ anaplastic large cell lymphoma and non-small-cell lung cancer (NSCLC) cells. Notably, ALK and PFKFB3 expressions exhibit significant correlation in clinic ALK+ NSCLC samples. We further demonstrated that ALK promotes PFKFB3 transcription through the downstream transcription factor STAT3. Upregulation of PFKFB3 by ALK is important for high glycolysis level as well as oncogenic activity of ALK+ lymphoma cells. Finally, targeting PFKFB3 by its inhibitor can overcome drug resistance in cells bearing TKI-resistant mutants of ALK. Collectively, our studies reveal a novel ALK-STAT3-PFKFB3 axis to promote cell proliferation and tumorigenesis, providing an alternative strategy for the treatment of ALK-positive tumors.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Anaplastic Lymphoma Kinase/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Line, Tumor , Drug Resistance, Neoplasm/genetics , Fructose , Humans , Lung Neoplasms/metabolism , Phosphofructokinase-2/genetics , Phosphofructokinase-2/metabolism , Protein Kinase Inhibitors/pharmacology , Proteomics , Receptor Protein-Tyrosine Kinases/genetics , Receptor Protein-Tyrosine Kinases/metabolism , Receptor, Insulin
7.
Chemosphere ; 243: 125372, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31759206

ABSTRACT

Electro-dewatering of sewage sludge with pulsating direct current (PDC-dewatering) was conducted to investigate the effects of pulsating frequency (0.01-60 Hz) and duty cycle (DTC) (20-100%) on sludge dewatering. The results indicated that both the frequency and DTC showed marked influences on electro-dewatering. Compared with the condition under the stable direct current (SDC-dewatering) of 30 V, the filtrate discharged from PDC-dewatering (at DTC of 40-60% and frequency of 30 Hz) was about 8% higher than that from SDC-dewatering. At DTC of 40%, the sludge electro-dewatering performance was promoted when the frequency increased from 0.01 Hz to 30 Hz. Compared with SDC-dewatering, PDC-dewatering can effectively mitigate ohmic heating. Layered tests were also conducted to investigate the differences of SDC- and PDC-dewatering in the distributions of water, pH, organic matters, zeta potential and conductivity in the upper, middle and lower layer of sludge cake. The results indicated that the variation tendencies of these parameters were similar between SDC- and PDC-dewatering, but the water, organic matters and charged ions in sludge cake were more homogeneously distributed during PDC-dewatering than SDC-dewatering. In addition, the anodic pH of PDC-dewatering was higher than that of SDC-dewatering, suggesting the potential of mitigating anodic corrosion during PDC-dewatering. Finally, energy consumptions of PDC- and SDC-dewatering were calculated and compared. The effects of frequency and DTC on energy consumption were investigated. PDC-dewatering was found to be more energy efficient than that of SDC-dewatering, making PDC-dewatering a promising electro-dewatering technology in future.


Subject(s)
Waste Disposal, Fluid/methods , Electricity , Electrodes , Ions , Sewage , Wastewater , Water
8.
Sci Adv ; 6(51)2020 12.
Article in English | MEDLINE | ID: mdl-33355139

ABSTRACT

Evolutionarily conserved DCAF1 is a major substrate receptor for the DDB1-CUL4-ROC1 E3 ubiquitin ligase (CRL4) and controls cell proliferation and development. The molecular basis for these functions is unclear. We show here that DCAF1 loss in multiple tissues and organs selectively eliminates proliferating cells and causes perinatal lethality, thymic atrophy, and bone marrow defect. Inducible DCAF1 loss eliminates proliferating, but not quiescent, T cells and MEFs. We identify the ribosome assembly factor PWP1 as a substrate of the CRL4DCAF1 ligase. DCAF1 loss results in PWP1 accumulation, impairing rRNA processing and ribosome biogenesis. Knockdown or overexpression of PWP1 can rescue defects or cause similar defects as DCAF1 loss, respectively, in ribosome biogenesis. DCAF1 loss increases free RPL11, resulting in L11-MDM2 association and p53 activation. Cumulatively, these results reveal a critical function for DCAF1 in ribosome biogenesis and define a molecular basis of DCAF1 function in cell proliferation and development.


Subject(s)
Carrier Proteins , Ubiquitin-Protein Ligases , Carrier Proteins/genetics , Cell Proliferation , Ribosomes/metabolism , Ubiquitin-Protein Ligases/metabolism
9.
Org Lett ; 22(6): 2206-2209, 2020 Mar 20.
Article in English | MEDLINE | ID: mdl-32124611

ABSTRACT

A catalyst-, oxidant-, electrolyte-free method for the preparation of α-ketoamides through the direct electrochemical amidation of α-ketoaldehydes and amines with innocuous hydrogen as the sole byproduct at ambient temperature was developed. The present reaction features clean and mild conditions, excellent functional-group tolerance, and high atom economy and scalability, enabling facile applications in pharmaceutical chemistry.

10.
J Med Chem ; 63(8): 4069-4080, 2020 04 23.
Article in English | MEDLINE | ID: mdl-32223235

ABSTRACT

BRAF is among the most frequently mutated oncogenes in human cancers. Multiple small molecule BRAF kinase inhibitors have been approved for treating melanoma carrying BRAF-V600 mutations. However, the benefits of BRAF kinase inhibitors are generally short-lived. Small molecule-mediated targeted protein degradation has recently emerged as a novel pharmaceutical strategy to remove disease proteins through hijacking the cellular ubiquitin proteasome system (UPS). In this study, we developed thalidomide-based heterobifunctional compounds that induced selective degradation of BRAF-V600E, but not the wild-type BRAF. Downregulation of BRAF-V600E suppressed the MEK/ERK kinase cascade in melanoma cells and impaired cell growth in culture. Abolishing the interaction between degraders and cereblon or blocking the UPS significantly impaired the activities of these degraders, validating a mechanistic role of UPS in mediating targeted degradation of BRAF-V600E. These findings highlight a new approach to modulate the functions of oncogenic BRAF mutants and provide a framework to treat BRAF-dependent human cancers.


Subject(s)
Drug Discovery/methods , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/metabolism , Proteolysis/drug effects , Proto-Oncogene Proteins B-raf/metabolism , Cell Survival/drug effects , Cell Survival/physiology , Dose-Response Relationship, Drug , Humans , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Vemurafenib/chemistry , Vemurafenib/metabolism , Vemurafenib/pharmacology
11.
J Med Chem ; 63(3): 1216-1232, 2020 02 13.
Article in English | MEDLINE | ID: mdl-31895569

ABSTRACT

Several epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors have been developed and approved by Food and Drug Administration for the treatment of non-small-cell lung cancers, but their efficacy can be compromised by acquired drug resistance conferred by EGFR-mutant variants. Here, we described the discovery of a novel E3 ligase von Hippel-Lindau-recruiting EGFR degrader, MS39 (compound 6), and a first-in-class E3 ligase cereblon-recruiting EGFR degrader, MS154 (compound 10), using the proteolysis targeting chimera technology. These compounds potently induced the degradation of mutant but not wild-type EGFR in an E3 ligase-dependent manner in cancer cell lines and effectively suppressed the growth of lung cancer cells compared with the corresponding negative controls. The global proteomic analyses revealed that the compounds were highly selective for EGFR. Furthermore, both compounds were bioavailable in mouse pharmacokinetic studies, and compound 6 is the first EGFR degrader suitable for in vivo efficacy studies. Overall, we provide a set of well-characterized chemical tools to the research community.


Subject(s)
Gefitinib/analogs & derivatives , Gefitinib/pharmacology , Protein Kinase Inhibitors/pharmacology , Adaptor Proteins, Signal Transducing/metabolism , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Design , Drug Discovery , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/genetics , ErbB Receptors/metabolism , Gefitinib/metabolism , Gefitinib/pharmacokinetics , Humans , Male , Mice , Mutation , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/metabolism , Protein Kinase Inhibitors/pharmacokinetics , Proteolysis , Signal Transduction/drug effects , Ubiquitin-Protein Ligases , Von Hippel-Lindau Tumor Suppressor Protein/metabolism
12.
J Med Chem ; 63(23): 14562-14575, 2020 12 10.
Article in English | MEDLINE | ID: mdl-33058680

ABSTRACT

We report compounds 5 (CG416) and 6 (CG428) as two first-in-class tropomyosin receptor kinase (TRK) degraders that target the intracellular kinase domain of TRK. Degraders 5 and 6 reduced levels of the tropomyosin 3 (TPM3)-TRKA fusion protein in KM12 colorectal carcinoma cells and inhibited downstream PLCγ1 signaling at sub-nanomolar concentrations. Both degraders also degraded human wild-type TRKA with similar potency. Interestingly, both degraders, especially 6, showed selectivity for the degradation of endogenous TPM3-TRKA over ectopically expressed ATP/GTP binding protein-like 4 (AGBL4)-TRKB or ETS variant transcription factor 6 (ETV6)-TRKC fusion proteins in KM12 cells. Global proteomic profiling assays demonstrated that 5 is highly selective for the intended target. TPM3-TRKA protein degradation induced by 5 and 6 was further confirmed to be mediated through cereblon and the ubiquitin-proteasome system. Compared with the parental TRK kinase inhibitor, both degraders exhibited higher potency for inhibiting growth of KM12 cells. Moreover, both 5 and 6 showed good plasma exposure levels in mice. Therefore, 5 and 6 are valuable chemical tool compounds for investigating the in vivo function of TRK fusion during tumorigenesis. Our study also paves the way for pharmacological degradation of TRK.


Subject(s)
Protein Kinase Inhibitors/pharmacology , Pyridazines/pharmacology , Receptor Protein-Tyrosine Kinases/antagonists & inhibitors , Thalidomide/analogs & derivatives , Thalidomide/pharmacology , Animals , Cell Line, Tumor , Down-Regulation/drug effects , Drug Design , Drug Discovery , Humans , Male , Mice, Inbred ICR , Molecular Structure , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacokinetics , Proteolysis/drug effects , Pyridazines/chemical synthesis , Pyridazines/pharmacokinetics , Receptor Protein-Tyrosine Kinases/metabolism , Receptor, trkA/antagonists & inhibitors , Receptor, trkA/metabolism , Receptor, trkB/antagonists & inhibitors , Receptor, trkB/metabolism , Receptor, trkC/antagonists & inhibitors , Receptor, trkC/metabolism , Structure-Activity Relationship , Thalidomide/pharmacokinetics , Ubiquitin-Protein Ligases/metabolism
13.
RSC Adv ; 9(54): 31212-31216, 2019 Oct 01.
Article in English | MEDLINE | ID: mdl-35527951

ABSTRACT

This study provides a direct, sustainable and eco-friendly method for the synthesis of various sulfonamides via the sulfonylation of sulfonyl hydrazides with tert-amines. The method utilizes sulfonyl hydrazides to oxidize and couple with tertiary amines through selective cleavage of C-N bonds. In this reaction, molecular iodine was used as the catalyst and t-butyl hydroperoxide was used as the oxidant.

14.
Sci Total Environ ; 663: 793-803, 2019 May 01.
Article in English | MEDLINE | ID: mdl-30738260

ABSTRACT

BACKGROUND: Human infection with the H7N9 virus has been reported recurrently since spring 2013. Given low pathogenicity of the virus in poultry, the outbreak cannot be noticed easily until a case of human infection is reported. Studies showed that the prevalence of influenza A subtype H7 in environmental samples is associated with the number of human H7N9 infection, with the latter associated with meteorological factors. Understanding the association between meteorological factors and the prevalence of H7 subtype in the environmental samples can shed light on how the virus propagates in the environment for disease control. METHOD: Environmental samples and meteorological data (precipitation, temperature, relative humidity, sunshine duration, and wind speed) collected in Zhejiang province, China, during 2013-2017 were used. A Bayesian hierarchical binomial logistic spatiotemporal model which captures spatiotemporal effects was adopted to model the prevalence of H7 subtype with the meteorological factors. RESULTS: The monthly overall prevalence of H7 subtype in the environmental samples was usually <30%. Compared with the odds at median, moderately low precipitation (49.19-115.60 mm), moderately long sunshine duration (4.22-9.25 h) and low temperature (<9.33 °C) were statistically significantly associated with a higher adjusted odds of detecting an H7-positive sample, whereas moderately high precipitation (119.51-146.85 mm), short and moderately short sunshine duration (<1.77 h; 4.00-4.17 h), and high temperature (>23.09 °C) were statistically significantly associated with a lower adjusted odds. The adjusted odds increased multiplicatively by 1.11 per 1% increase in relative humidity. CONCLUSION: Since the prevalence of H7 subtype in environmental samples was associated with meteorological conditions and the number of human H7N9 infection, an environmental surveillance program which incorporates meteorological conditions in planning allows for early detection of the spread of the virus in the environment and better preparation for the outbreak in the human population.


Subject(s)
Epidemiological Monitoring/veterinary , Influenza A Virus, H7N9 Subtype/physiology , Influenza, Human/epidemiology , Orthomyxoviridae Infections/veterinary , Population Surveillance , Animals , China/epidemiology , Humans , Influenza, Human/virology , Meteorological Concepts , Orthomyxoviridae Infections/epidemiology , Orthomyxoviridae Infections/virology , Prevalence , Spatio-Temporal Analysis
15.
EBioMedicine ; 45: 393-407, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31303501

ABSTRACT

BACKGROUND: Recent studies have revealed that vitamin D deficiency may increase the risk of Alzheimer's disease, and vitamin D supplementation may be effective strategy to ameliorate the neurodegenerative process in Alzheimer's disease patients. Paricalcitol (PAL), a low-calcemic vitamin D receptor agonist, is clinically used to treat secondary hyperparathyroidism. However, the potential application of PAL for treating neurodegenerative disorders remains unexplored. METHODS: The APP/PS1 mice were intraperitoneally injected with PAL or vehicle every other day for 15 weeks. The ß-amyloid (Aß) production was confirmed using immunostaining and enzyme linked immunosorbent assay. The underlying mechanism was verified by western blot and immunostaining in vivo and in vitro. FINDINGS: Long-term PAL treatment clearly reduced ß-amyloid (Aß) generation and neuronal loss in APP/PS1 transgenic mouse brains. PAL stimulated the expression of low-density lipoprotein receptor-related protein 1 (LRP1) possibly through inhibiting sterol regulatory element binding protein-2 (SREBP2); PAL also promoted LRP1-mediated ß-site APP cleavage enzyme 1 (BACE1) transport to late endosomes, thus increasing the lysosomal degradation of BACE1. Furthermore, PAL diminished 8-hydroxyguanosine (8-OHdG) generation in neuronal mitochondria via enhancing base excision repair (BER), resulting in the attenuation of calpain-1-mediated neuronal loss. INTERPRETATION: The present data demonstrate that PAL can reduce Aß generation through accelerating BACE1 lysosomal degradation and can inhibit neuronal loss through suppressing mitochondrial 8-OHdG generation. Hence, PAL might be a promising agent for treating Alzheimer's disease. FUND: This study was financially supported by the Natural Science Foundation of China (U1608282).


Subject(s)
Alzheimer Disease/drug therapy , Amyloid Precursor Protein Secretases/genetics , Aspartic Acid Endopeptidases/genetics , Ergocalciferols/pharmacology , Neurons/drug effects , 8-Hydroxy-2'-Deoxyguanosine/metabolism , Alzheimer Disease/genetics , Alzheimer Disease/pathology , Amyloid beta-Peptides/genetics , Animals , Brain/metabolism , Brain/pathology , Calpain/genetics , Disease Models, Animal , Gene Expression Regulation/drug effects , Humans , Low Density Lipoprotein Receptor-Related Protein-1/genetics , Lysosomes/drug effects , Lysosomes/genetics , Mice , Mice, Transgenic , Mitochondria/metabolism , Neurons/pathology , Oligopeptides/genetics , Presenilin-1/genetics , Proteolysis/drug effects
16.
Sci Rep ; 9(1): 4869, 2019 03 19.
Article in English | MEDLINE | ID: mdl-30890762

ABSTRACT

Hong Kong is a high-income city with intermediate tuberculosis (TB) burden primarily driven by endogenous reactivations. A high proportion of remote latently infected people, particularly elderly, hinders the effectiveness of current strategies focusing on passive TB detection. In this study, we developed a mathematical model to evaluate the impact of treating latent TB infection (LTBI) in the elderly in addition to current TB control strategies. The model was calibrated using the annual age-stratified TB notifications from 1965-2013 in Hong Kong. Our results showed that at present, approximately 75% of annual new notifications were from reactivations. Given the present treatment completion rate, even if only a low to moderate proportion (approximately 20% to 40%) of elderly people were screened and treated for LTBI, the overall TB incidence could be reduced by almost 50%, to reach the 2025 milestone of the global End TB Strategy. Nevertheless, due to a high risk of hepatotoxicity in elderly population, benefit-risk ratios were mostly below unity; thus, intervention programs should be carefully formulated, including prioritising LTBI treatment for high-risk elderly groups who are closely monitored for possible adverse side effects.


Subject(s)
Cost of Illness , Latent Tuberculosis/epidemiology , Models, Theoretical , Aged , Antitubercular Agents/therapeutic use , Cities/epidemiology , Hong Kong/epidemiology , Humans , Latent Tuberculosis/microbiology , Risk Assessment
17.
Eur J Med Chem ; 151: 304-314, 2018 May 10.
Article in English | MEDLINE | ID: mdl-29627725

ABSTRACT

Anaplastic lymphoma kinase (ALK) activation has been associated with many types of human cancer. Significant efforts have been devoted to the development of ALK inhibitors to antagonize the kinase activity of ALK. Four ALK inhibitors have been approved by the FDA to date for treating patients with ALK-positive non-small cell lung cancers (NSCLC). However, drug resistance has been observed in the majority of patients treated with these inhibitors. New therapeutic strategies (e.g., compounds with novel mechanisms of action) are needed to overcome the drug resistance issue. The emerging PROTAC (Proteolysis Targeting Chimera) technology has been successfully applied to selective degradation of multiple protein targets, but not ALK. Since ALK protein levels are not important for viability in mammals, ALK PROTACs could lead to novel therapeutics with minimal toxicity. Here we report the design, synthesis and biological evaluation of novel PROTACs (degraders) of ALK. MS4077 (5) and MS4078 (6) potently decreased cellular levels of oncogenic active ALK fusion proteins in a concentration- and time-dependent manner in SU-DHL-1 lymphoma and NCI-H2228 lung cancer cells. The ALK protein degradation induced by compounds 5 and 6 was cereblon and proteasome dependent. In addition, compounds 5 and 6 potently inhibited proliferation of SU-DHL-1 cells. Furthermore, compound 6 displayed good plasma exposure in a mouse pharmacokinetic study, thus is suitable for in vivo efficacy studies. We also developed MS4748 (7) and MS4740 (8), very close analogs of 5 and 6 respectively, which are incapable to degrade the ALK fusion proteins, as negative controls. Compounds 5-8 are valuable chemical tools for investigating effects of ALK pharmacological degradation. Our study paved the way for developing the next generation of ALK PROTACs.


Subject(s)
Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Proteolysis/drug effects , Receptor Protein-Tyrosine Kinases/antagonists & inhibitors , Anaplastic Lymphoma Kinase , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Design , Humans , Lung Neoplasms/drug therapy , Lung Neoplasms/metabolism , Lymphoma/drug therapy , Lymphoma/metabolism , Male , Mice , Protein Kinase Inhibitors/pharmacokinetics , Receptor Protein-Tyrosine Kinases/metabolism , Signal Transduction/drug effects
18.
Sci Total Environ ; 644: 696-709, 2018 Dec 10.
Article in English | MEDLINE | ID: mdl-29990917

ABSTRACT

BACKGROUND: Since the first reported human infection with an avian-origin influenza A (H7N9) virus in China in early 2013, there have been recurrent outbreaks of the virus in the country. Previous studies have shown that meteorological factors are associated with the risk of human infection with the virus; however, their possible nonlinear and lagged effects were not commonly taken into account. METHOD: To quantify the effect of meteorological factors on the risk of human H7N9 infection, daily laboratory-confirmed cases of human H7N9 infection and meteorological factors including total rainfall, average wind speed, average temperature, average relative humidity, and sunshine duration of the 11 sub-provincial/prefecture cities in Zhejiang during the first four outbreaks (13 March 2013-30 June 2016) were analyzed. Separate models were built for the 6 sub-provincial/prefecture cities with the greatest number of reported cases using a combination of logistic generalized additive model and distributed lag nonlinear models, which were then pooled by a multivariate meta-regression model to determine their overall effects. RESULTS: According to the meta-regression model, for rainfall, the log adjusted overall cumulative odds ratio was statistically significant when log of rainfall was >4.0, peaked at 5.3 with a value of 12.42 (95% confidence intervals (CI): [3.23, 21.62]). On the other hand, when wind speed was 2.1-3.0 m/s or 6.3-7.1 m/s, the log adjusted overall cumulative odds ratio was statistically significant, peaked at 7.1 m/s with a value of 6.75 (95% CI: [0.03, 13.47]). There were signs of nonlinearity and lag effects in their associations with the risk of infection. CONCLUSION: As rainfall and wind speed were found to be associated with the risk of human H7N9 infection, weather conditions should be taken into account when it comes to disease surveillance, allowing prompt actions when an outbreak takes place.


Subject(s)
Influenza A Virus, H7N9 Subtype , Influenza, Human/epidemiology , Meteorological Concepts , Animals , Birds , China , Cities , Humans , Influenza in Birds/epidemiology , Influenza in Birds/transmission , Influenza, Human/transmission
19.
Cell Discov ; 2: 16005, 2016.
Article in English | MEDLINE | ID: mdl-27462452

ABSTRACT

Population-based and case-control studies in different ethnicities have linked a polymorphism, C825T, in exon 10 of GNB3 gene to hypertension and several additional diseases. The 825T allele is associated with alternative splicing and results in a shortened Gß3 protein, referred to as Gß3s, which loses 41 amino acids encompassing one WD40 repeat domain. The mechanism of how Gß3 C825T polymorphism is associated with hypertension has remained unclear, but an impairment of its canonical function in G-protein-coupled receptor signaling has been ruled out. Here, we report that Gß3, like other Gß proteins, binds to DDB1 and assembles a DDB1-CUL4A-ROC1 E3 ubiquitin ligase (CRL4A(Gß3)) to target GRK2 ubiquitination. The loss of the 41 amino-acid residues disrupts the Gß3-DDB1 binding and impairs the function of Gß3s to ubiquitinate GRK2. GRK2 ubiquitination levels were decreased and protein levels were accumulated in the blood samples of Gß3 825T allele carriers. Deletion of Cul4a in mice resulted in systolic pressure increased and weakened heart function in male mice that can be partially rescued by the deletion of one Grk2 allele. These results reveal a mechanism explaining the link between Gß3 C825T polymorphism and hypertension.

20.
Oncotarget ; 7(48): 78985-78993, 2016 Nov 29.
Article in English | MEDLINE | ID: mdl-27738317

ABSTRACT

OBJECTIVES: Estimate the epidermal growth factor receptor (EGFR) mutation prevalence in all non-small cell lung cancer (NSCLC) patients and patient subgroups. RESULTS: A total of 456 studies were included, reporting 30,466 patients with EGFR mutation among 115,815 NSCLC patients. The overall pooled prevalence for EGFR mutations was 32.3% (95% CI 30.9% to 33.7%), ranging from 38.4% (95% CI: 36.5% to 40.3%) in China to 14.1% (95% CI: 12.7% to 15.5%) in Europe. The pooled prevalence of EGFR mutation was higher in females (females vs. males: 43.7% vs. 24.0%; OR: 2.7, 95% CI: 2.5 to 2.9), non-smokers (non-smokers vs. past or current smokers: 49.3% vs. 21.5%; OR: 3.7, 95% CI: 3.4 to 4.0), and patients with adenocarcinoma (adenocarcinoma vs. non-adenocarcinoma: 38.0% vs. 11.7%; OR: 4.1, 95% CI: 3.6 to 4.8). MATERIALS AND METHODS: PubMed, EMBASE, and the Cochrane Library were searched to June 2013. Eligible studies reported EGFR mutation prevalence and the association with at least one of the following factors: gender, smoking status and histology. Random-effects models were used to pool EGFR mutation prevalence data. CONCLUSION: This study provides the exact prevalence of EGFR mutations in different countries and NSCLC patient subgroups.


Subject(s)
Carcinoma, Non-Small-Cell Lung/genetics , ErbB Receptors/genetics , Lung Neoplasms/genetics , Mutation , Asian People/genetics , China , Europe , Female , Genetic Predisposition to Disease , Humans , Male , Mutation Rate , Prevalence , Risk Factors , Smoking/genetics , White People/genetics
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