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1.
Biochemistry ; 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38915291

RESUMEN

The cockroach allergen Bla g 1 encloses an exceptionally large hydrophobic cavity, which allows it to bind and deliver unsaturated fatty acid ligands. Bla g 1-mediated delivery of naturally occurring (nMix) ligands has been shown to destabilize lipid membranes, contributing to its digestive/antiviral functions within the source organism. However, the consequences of this activity on Bla g 1 allergenicity following human exposure remain unknown. In this work, we show that Bla g 1-mediated membrane disruption can induce a proinflammatory immune response in mammalian cells via two complementary pathways. At high concentrations, the cytotoxic activity of Bla g 1 induces the release of proinflammatory cytosolic contents including damage-associated molecular patterns (DAMPs) such as heat-shock Protein-70 (HSP70) and the cytokine interleukin-1 (IL-1ß). Sublytic concentrations of Bla g 1 enhanced the ability of phospholipase A2 (PLA2) to extract and hydrolyze phospholipid substrates from cellular membranes, stimulating the production of free polyunsaturated fatty acids (PUFAs) and various downstream inflammatory lipid mediators. Both of these effects are dependent on the presence of Bla g 1's natural fatty-acid (nMix) ligands with CC50 values corresponding to the concentrations required for membrane destabilization reported in previous studies. Taken together, these results suggest that mechanisms through which Bla g 1-mediated lipid delivery and membrane destabilization could directly contribute to cockroach allergic sensitization.

2.
J Immunol ; 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38912868

RESUMEN

Neutrophils play important roles in inflammatory airway diseases. In this study, we assessed whether apolipoprotein A-I modifies neutrophil heterogeneity as part of the mechanism by which it attenuates acute airway inflammation. Neutrophilic airway inflammation was induced by daily intranasal administration of LPS plus house dust mite (LPS+HDM) to Apoa1-/- and Apoa1+/+ mice for 3 d. Single-cell RNA sequencing was performed on cells recovered from bronchoalveolar lavage fluid on day 4. Unsupervised profiling identified 10 clusters of neutrophils in bronchoalveolar lavage fluid from Apoa1-/- and Apoa1+/+ mice. LPS+HDM-challenged Apoa1-/- mice had an increased proportion of the Neu4 neutrophil cluster that expressed S100a8, S100a9, and Mmp8 and had high maturation, aggregation, and TLR4 binding scores. There was also an increase in the Neu6 cluster of immature neutrophils, whereas neutrophil clusters expressing IFN-stimulated genes were decreased. An unsupervised trajectory analysis showed that Neu4 represented a distinct lineage in Apoa1-/- mice. LPS+HDM-challenged Apoa1-/- mice also had an increased proportion of recruited airspace macrophages, which was associated with a reciprocal reduction in resident airspace macrophages. Increased expression of a common set of proinflammatory genes, S100a8, S100a9, and Lcn2, was present in all neutrophils and airspace macrophages from LPS+HDM-challenged Apoa1-/- mice. These findings show that Apoa1-/- mice have increases in specific neutrophil and macrophage clusters in the lung during acute inflammation mediated by LPS+HDM, as well as enhanced expression of a common set of proinflammatory genes. This suggests that modifications in neutrophil and macrophage heterogeneity contribute to the mechanism by which apolipoprotein A-I attenuates acute airway inflammation.

3.
Angew Chem Int Ed Engl ; : e202407702, 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38751355

RESUMEN

The current bottleneck in the development of efficient photocatalysts for hydrogen evolution is the limited availability of high-performance acceptor units. Over the past nine years, dibenzo[b,d]thiophene sulfone (DBS) has been the preferred choice for the acceptor unit. Despite extensive exploration of alternative structures as potential replacements for DBS, a superior substitute remains elusive. In this study, a symmetry-breaking strategy was employed on DBS to develop a novel acceptor unit, BBTT-1SO. The asymmetric structure of BBTT-1SO proved beneficial for increasing multiple moment and polarizability. BBTT-1SO-containing polymers showed higher efficiencies for hydrogen evolution than their DBS-containing counterparts by up to 166 %. PBBTT-1SO exhibited an excellent hydrogen evolution rate (HER) of 222.03 mmol g-1 h-1 and an apparent quantum yield of 27.5 % at 500 nm. Transient spectroscopic studies indicated that the BBTT-1SO-based polymers facilitated electron polaron formation, which explains their superior HERs. PBBTT-1SO also showed 14 % higher HER in natural seawater splitting than that in deionized water splitting. Molecular dynamics simulations highlighted the enhanced water-PBBTT-1SO polymer interactions in salt-containing solutions. This study presents a pioneering example of a substitute acceptor unit for DBS in the construction of high-performance photocatalysts for hydrogen evolution.

4.
Small ; 19(42): e2302682, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37322304

RESUMEN

Conjugated polymers (CPs) have recently gained increasing attention as photocatalysts for sunlight-driven hydrogen evolution. However, they suffer from insufficient electron output sites and poor solubility in organic solvents, severely limiting their photocatalytic performance and applicability. Herein, solution-processable all-acceptor (A1 -A2 )-type CPs based on sulfide-oxidized ladder-type heteroarene are synthesized. A1 -A2 -type CPs showed upsurging efficiency improvements by two to three orders of magnitude, compared to their donor-acceptor -type CP counterparts. Furthermore, by seawater splitting, PBDTTTSOS exhibited an apparent quantum yield of 18.9% to 14.8% at 500 to 550 nm. More importantly, PBDTTTSOS achieved an excellent hydrogen evolution rate of 35.7 mmol h-1  g-1 and 150.7 mmol h-1  m-2 in the thin-film state, which is among the highest efficiencies in thin film polymer photocatalysts to date. This work provides a novel strategy for designing polymer photocatalysts with high efficiency and broad applicability.

5.
Heliyon ; 9(5): e16408, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37251870

RESUMEN

Background: Chromosome analysis is laborious and time-consuming. Automated methods can significantly increase the efficiency of chromosome analysis. For the automated analysis of chromosome images, single and clustered chromosomes must be identified. Herein, we propose a feature-based method for distinguishing between single chromosomes and clustered chromosome. Method: The proposed method comprises three main steps. In the first step, chromosome objects are segmented from metaphase chromosome images in advance. In the second step, seven features are extracted from each segmented object, i.e., the normalized area, area/boundary ratio, side branch index, exhaustive thresholding index, normalized minimum width, minimum concave angle, and maximum boundary shift. Finally, the segmented objects are classified as a single chromosome or chromosome cluster using a combination of the seven features. Results: In total, 43,391 segmented objects, including 39,892 single chromosomes and 3,499 chromosome clusters, are used to evaluate the proposed method. The results show that the proposed method achieves an accuracy of 98.92% by combining the seven features using support vector machine. Conclusions: The proposed method is highly effective in distinguishing between single and clustered chromosomes and can be used as a preprocessing procedure for automated chromosome image analysis.

6.
Drug Des Devel Ther ; 15: 2577-2591, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34168430

RESUMEN

INTRODUCTION: Novel radiotracer development for imaging dopamine transporters is a subject of interest because although [99mTc]TRODAT-1, [123I]ß-CIT, and [123I]FP-CIT are commercially available; 99Mo/99mTc generator is in short supply and 123I production is highly dependent on compact cyclotron. Therefore, we designed a novel positron emission tomography (PET) tracer based on a tropane derivative through C-2 modification to conjugate NOTA for chelating 68Ga, a radioisotope derived from a 68Ge/68Ga generator. METHODS: IPCAT-NOTA 22 was synthesized and labeled with [68Ga]GaCl4 - at room temperature. Biological studies on serum stability, LogP, and in vitro autoradiography (binding assay and competitive assay) were performed. Furthermore, ex vivo autoradiography, biodistribution, and dynamic PET imaging studies were performed in Sprague Dawley rats. RESULTS: [68Ga]IPCAT-NOTA 24 obtained had a radiochemical yield of ≥90% and a specific activity of 4.25 MBq/nmol. [68Ga]IPCAT-NOTA 24 of 85% radiochemical purity (RCP%) was stable at 37°C for up to 60 minutes in serum with a lipophilicity of 0.88. The specific binding ratio (SBR%) reached 15.8 ± 6.7 at 60 minutes, and the 85% specific uptake could be blocked through co-injection at 100- and 1000-fold of the cold precursor in in vitro binding studies. Tissue regional distribution studies in rats with [68Ga]IPCAT-NOTA 24 showed striatal uptake (0.02% at 5 minutes and 0.007% at 60 minutes) with SBR% of 6%, 25%, and 62% at 5-15, 30-40, and 60-70 minutes, respectively, in NanoPET studies. The RCP% of [68Ga]IPCAT-NOTA 24 at 30 minutes in vivo remained 67.65%. CONCLUSION: Data described here provide new information on the design of PET probe of conjugate/pendent approach for DAT imaging. Another chelator or another direct method of intracranial injection must be used to prove the relation between [68Ga]IPCAT-NOTA 24 uptake and transporter localization.


Asunto(s)
Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/metabolismo , Radioisótopos de Galio/química , Compuestos Heterocíclicos con 1 Anillo/química , Tomografía de Emisión de Positrones/métodos , Animales , Autorradiografía/métodos , Compuestos Heterocíclicos con 1 Anillo/síntesis química , Masculino , Ratas , Ratas Sprague-Dawley , Factores de Tiempo , Distribución Tisular
7.
Int J Radiat Biol ; 97(7): 916-925, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34003708

RESUMEN

PURPOSE: The dicentric chromosome assay (DCA), the gold standard for radiation biodosimetry, evaluates an individual absorbed radiation dose by the analysis of DNA damage in human lymphocytes. The conventional (C-DCA) and QuickScan (QS-DCA) scoring methods are sensitive for estimating radiation dose. The Biodosimetry Laboratory at Institute of Nuclear Energy Research (INER), Taiwan, participated in intercomparison exercises conducted by Health Canada (HC) in 2014, 2015 and 2018 to validate the laboratory's accuracy and performance. MATERIAL AND METHODS: Blood samples for the conventional dose response curve for Taiwan were irradiated with 0, 0.25, 0.5, 1, 2, 3, 4 and 5 Gy. Ten blind blood samples were provided by HC. Either or both of two methods of conventional (C) or QuickScan (QS) scoring could be chosen for the HC's intercomparison. For C-DCA triage scoring, only cells with 46 centromeres were counted and each scorer recorded the number of dicentrics in the first 50 metaphases or stopped scoring when 30 dicentrics were reached. Scorers also recorded how much time it took to analyze 10, 20, and 50 cells. Subsequently, the data were entered into the Dose Estimate software (DoseEstimate_v5.1) and dose estimates were calculated. With QS-DCA scoring, a minimum of 50 metaphase cells (or 30 dicentrics) were scored in apparently complete metaphases without verification of exactly 46 centromeres. RESULTS: For the blinded blood samples irradiated at HC and shipped to INER, the mean absolute deviation (MAD) derived after scoring 50 cells for C-DCA and QS-DCA was <0.5 Gy for all three intercomparisons, meeting the criteria for acceptance. CONCLUSION: The results indicated that the Biodosimetry Laboratory at INER can provide reliable dose estimates in the case of a large-scale radiation accident.


Asunto(s)
Radiometría/métodos , Cromosomas Humanos/genética , Cromosomas Humanos/efectos de la radiación , Relación Dosis-Respuesta en la Radiación , Humanos , Validez Social de la Investigación , Taiwán
8.
Cell Mol Life Sci ; 78(9): 4095-4124, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33544156

RESUMEN

The neutrophil, a short-lived effector leukocyte of the innate immune system best known for its proteases and other degradative cargo, has unique, reciprocal physiological interactions with the lung. During health, large numbers of 'marginated' neutrophils reside within the pulmonary vasculature, where they patrol the endothelial surface for pathogens and complete their life cycle. Upon respiratory infection, rapid and sustained recruitment of neutrophils through the endothelial barrier, across the extravascular pulmonary interstitium, and again through the respiratory epithelium into the airspace lumen, is required for pathogen killing. Overexuberant neutrophil trafficking to the lung, however, causes bystander tissue injury and underlies several acute and chronic lung diseases. Due in part to the unique architecture of the lung's capillary network, the neutrophil follows a microanatomic passage into the distal airspace unlike that observed in other end-organs that it infiltrates. Several of the regulatory mechanisms underlying the stepwise recruitment of circulating neutrophils to the infected lung have been defined over the past few decades; however, fundamental questions remain. In this article, we provide an updated review and perspective on emerging roles for the neutrophil in lung biology, on the molecular mechanisms that control the trafficking of neutrophils to the lung, and on past and ongoing efforts to design therapeutics to intervene upon pulmonary neutrophilia in lung disease.


Asunto(s)
Infiltración Neutrófila/fisiología , Neutrófilos/inmunología , Quimiocinas/metabolismo , Factores Quimiotácticos/farmacología , Citocinas/metabolismo , Endotelio/inmunología , Endotelio/metabolismo , Matriz Extracelular/metabolismo , Humanos , Pulmón/inmunología , Pulmón/metabolismo , Enfermedades Pulmonares/inmunología , Enfermedades Pulmonares/metabolismo , Enfermedades Pulmonares/patología , Infiltración Neutrófila/efectos de los fármacos , Neutrófilos/citología , Neutrófilos/metabolismo
9.
Nat Immunol ; 22(3): 312-321, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33510463

RESUMEN

Mitochondrial abnormalities have been noted in lupus, but the causes and consequences remain obscure. Autophagy-related genes ATG5, ATG7 and IRGM have been previously implicated in autoimmune disease. We reasoned that failure to clear defective mitochondria via mitophagy might be a foundational driver in autoimmunity by licensing mitochondrial DNA-dependent induction of type I interferon. Here, we show that mice lacking the GTPase IRGM1 (IRGM homolog) exhibited a type I interferonopathy with autoimmune features. Irgm1 deletion impaired the execution of mitophagy with cell-specific consequences. In fibroblasts, mitochondrial DNA soiling of the cytosol induced cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING)-dependent type I interferon, whereas in macrophages, lysosomal Toll-like receptor 7 was activated. In vivo, Irgm1-/- tissues exhibited mosaic dependency upon nucleic acid receptors. Whereas salivary and lacrimal gland autoimmune pathology was abolished and lung pathology was attenuated by cGAS and STING deletion, pancreatic pathology remained unchanged. These findings reveal fundamental connections between mitochondrial quality control and tissue-selective autoimmune disease.


Asunto(s)
Enfermedades Autoinmunes/metabolismo , Autoinmunidad , Fibroblastos/metabolismo , Proteínas de Unión al GTP/metabolismo , Mitocondrias/metabolismo , Mitofagia , Animales , Enfermedades Autoinmunes/genética , Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/patología , Células Cultivadas , Fibroblastos/inmunología , Fibroblastos/patología , Proteínas de Unión al GTP/deficiencia , Proteínas de Unión al GTP/genética , Regulación de la Expresión Génica , Macrófagos/inmunología , Macrófagos/metabolismo , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones Endogámicos C57BL , Mitocondrias/genética , Mitocondrias/inmunología , Mitocondrias/patología , Nucleotidiltransferasas/genética , Nucleotidiltransferasas/metabolismo , Transducción de Señal , Receptor Toll-Like 7/genética , Receptor Toll-Like 7/metabolismo
10.
Am J Occup Ther ; 74(3): 7403205130p1-7403205130p10, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32365319

RESUMEN

IMPORTANCE: Before introducing strategy training into a cross-cultural (Chinese) context, it is necessary to evaluate its feasibility. OBJECTIVE: To examine the feasibility of applying strategy training to improve participation outcomes of rehabilitation patients in Taiwan and evaluate the potential intervention effects. DESIGN: A single-group, repeated-measures study. SETTING: Rehabilitation outpatient settings. PARTICIPANTS: A convenience sample of adults (N = 20) with a primary diagnosis of acquired brain injury (ABI) and with cognitive impairment received the intervention and were assessed before and after it. INTERVENTION: The participation-focused strategy training intervention, a modified version of the strategy training intervention, was provided to participants in 1-2 sessions weekly for a total of 10-20 intervention sessions. OUTCOMES AND MEASURES: Feasibility indicators, Participation Measure-3 Domains, 4 Dimensions (PM-3D4D), and Canadian Occupational Performance Measure (COPM). RESULTS: Eighteen participants completed 100% of the scheduled intervention sessions. Participants had very good engagement in the intervention sessions with sufficient comprehension. Participants reported moderate to high satisfaction. Positive score changes were observed for the PM-3D4D (d = 0.46-1.25) and COPM scales (d = 1.82 and 2.12). CONCLUSIONS AND RELEVANCE: This study demonstrated the feasibility of delivering participation-focused strategy training in Taiwan to people with cognitive impairment after ABI. The preliminary evidence also showed that participants who received the strategy training intervention had positive changes in participation outcomes and in performance of their self-identified goals. On the basis of this study's findings, a larger clinical trial is warranted to evaluate the efficacy of the strategy training intervention. WHAT THIS ARTICLE ADDS: Participation-focused strategy training is feasible and acceptable for Taiwanese community-dwelling adults with cognitive impairment after ABI. However, because strategy training is quite different from traditional rehabilitation delivered in Taiwan, additional instructions and discussion among the therapist, client, and caregiver may be needed before the intervention is provided.


Asunto(s)
Lesiones Encefálicas/rehabilitación , Disfunción Cognitiva/rehabilitación , Terapia Ocupacional , Adulto , Estudios de Factibilidad , Humanos , Taiwán
12.
J Clin Invest ; 130(1): 157-170, 2020 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-31550239

RESUMEN

Whether respiratory epithelial cells regulate the final transit of extravasated neutrophils into the inflamed airspace or are a passive barrier is poorly understood. Alveolar epithelial type 1 (AT1) cells, best known for solute transport and gas exchange, have few established immune roles. Epithelial membrane protein 2 (EMP2), a tetraspan protein that promotes recruitment of integrins to lipid rafts, is highly expressed in AT1 cells but has no known function in lung biology. Here, we show that Emp2-/- mice exhibit reduced neutrophil influx into the airspace after a wide range of inhaled exposures. During bacterial pneumonia, Emp2-/- mice had attenuated neutrophilic lung injury and improved survival. Bone marrow chimeras, intravital neutrophil labeling, and in vitro assays suggested that defective transepithelial migration of neutrophils into the alveolar lumen occurs in Emp2-/- lungs. Emp2-/- AT1 cells had dysregulated surface display of multiple adhesion molecules, associated with reduced raft abundance. Epithelial raft abundance was dependent upon putative cholesterol-binding motifs in EMP2, whereas EMP2 supported adhesion molecule display and neutrophil transmigration through suppression of caveolins. Taken together, we propose that EMP2-dependent membrane organization ensures proper display on AT1 cells of a suite of proteins required to instruct paracellular neutrophil traffic into the alveolus.


Asunto(s)
Células Epiteliales Alveolares/fisiología , Glicoproteínas de Membrana/fisiología , Neutrófilos/fisiología , Animales , Línea Celular , Movimiento Celular , Quimiocina CXCL1/fisiología , Microdominios de Membrana/fisiología , Ratones , Ratones Endogámicos C57BL , Neumonía Bacteriana/mortalidad
13.
Nat Commun ; 10(1): 5114, 2019 11 08.
Artículo en Inglés | MEDLINE | ID: mdl-31704972

RESUMEN

Triple-negative breast cancer (TNBC), which lacks estrogen receptor α (ERα), progesterone receptor, and human epidermal growth factor receptor 2 (HER2) expression, is closely related to basal-like breast cancer. Previously, we and others report that cyclin E/cyclin-dependent kinase 2 (CDK2) phosphorylates enhancer of zeste homolog 2 (EZH2) at T416 (pT416-EZH2). Here, we show that transgenic expression of phospho-mimicking EZH2 mutant EZH2T416D in mammary glands leads to tumors with TNBC phenotype. Coexpression of EZH2T416D in mammary epithelia of HER2/Neu transgenic mice reprograms HER2-driven luminal tumors into basal-like tumors. Pharmacological inhibition of CDK2 or EZH2 allows re-expression of ERα and converts TNBC to luminal ERα-positive, rendering TNBC cells targetable by tamoxifen. Furthermore, the combination of either CDK2 or EZH2 inhibitor with tamoxifen effectively suppresses tumor growth and markedly improves the survival of the mice bearing TNBC tumors, suggesting that the mechanism-based combination therapy may be an alternative approach to treat TNBC.


Asunto(s)
Quinasa 2 Dependiente de la Ciclina/metabolismo , Proteína Potenciadora del Homólogo Zeste 2/genética , Receptor alfa de Estrógeno/efectos de los fármacos , Neoplasias Mamarias Experimentales/genética , Neoplasias de la Mama Triple Negativas/genética , Animales , Benzamidas/farmacología , Compuestos de Bifenilo , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Óxidos N-Cíclicos , Quinasa 2 Dependiente de la Ciclina/antagonistas & inhibidores , Proteína Potenciadora del Homólogo Zeste 2/antagonistas & inhibidores , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismo , Femenino , Humanos , Indolizinas , Glándulas Mamarias Humanas/efectos de los fármacos , Glándulas Mamarias Humanas/metabolismo , Neoplasias Mamarias Experimentales/metabolismo , Ratones , Ratones Transgénicos , Morfolinas , Fosforilación , Compuestos de Piridinio/farmacología , Piridonas/farmacología , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Receptores de Progesterona/metabolismo , Neoplasias de la Mama Triple Negativas/metabolismo
14.
J Biol Chem ; 294(6): 1997-2008, 2019 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-30523158

RESUMEN

Toll-like receptors (TLRs) are pathogen-recognition receptors that trigger the innate immune response. Recent reports have identified accessory proteins that provide essential support to TLR function through ligand delivery and receptor trafficking. Herein, we introduce leucine-rich repeats (LRRs) and calponin homology containing 4 (Lrch4) as a novel TLR accessory protein. Lrch4 is a membrane protein with nine LRRs in its predicted ectodomain. It is widely expressed across murine tissues and has two expression variants that are both regulated by lipopolysaccharide (LPS). Predictive modeling indicates that Lrch4 LRRs conform to the horseshoe-shaped structure typical of LRRs in pathogen-recognition receptors and that the best structural match in the protein database is to the variable lymphocyte receptor of the jawless vertebrate hagfish. Silencing Lrch4 attenuates cytokine induction by LPS and multiple other TLR ligands and dampens the in vivo innate immune response. Lrch4 promotes proper docking of LPS in lipid raft membrane microdomains. We provide evidence that this is through regulation of lipid rafts as Lrch4 silencing reduces cell surface gangliosides, a metric of raft abundance, as well as expression and surface display of CD14, a raft-resident LPS co-receptor. Taken together, we identify Lrch4 as a broad-spanning regulator of the innate immune response and a potential molecular target in inflammatory disease.


Asunto(s)
Regulación de la Expresión Génica , Inmunidad Innata , Receptores Toll-Like , Animales , Gangliósidos/metabolismo , Leucina , Ligandos , Receptores de Lipopolisacáridos , Lipopolisacáridos/metabolismo , Microdominios de Membrana/metabolismo , Proteínas de la Membrana/química , Proteínas de la Membrana/metabolismo , Ratones , Conformación Proteica , Dominios Proteicos
15.
Cell Rep ; 18(9): 2243-2255, 2017 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-28249168

RESUMEN

Mutant KRAS and c-MYC are oncogenic drivers and rational therapeutic targets for the treatment of pancreatic cancer. Although tumor growth and homeostasis are largely dependent on these oncogenes, a few residual cancer cells are able to survive the ablation of mutant KRAS and c-MYC. By performing a genome-wide gene expression analysis of in vivo-derived bulk tumor cells and residual cancer cells lacking the expression of mutant KRAS or c-MYC, we have identified an increase in autocrine IGF1/AKT signaling as a common survival mechanism in dormant cancer cells. The pharmacological inhibition of IGF-1R reduces residual disease burden and cancer recurrence, suggesting that this molecular pathway is crucial for the survival of cancer cells in the absence of the primary oncogenic drivers.


Asunto(s)
Comunicación Autocrina/genética , Factor I del Crecimiento Similar a la Insulina/genética , Oncogenes/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patología , Transducción de Señal/genética , Animales , Carcinogénesis/genética , Carcinogénesis/patología , Línea Celular Tumoral , Proliferación Celular/genética , Expresión Génica/genética , Genes myc/genética , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Mutación/genética , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patología , Páncreas/patología , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas p21(ras)/genética , Receptor IGF Tipo 1/genética
16.
Cancer Cell ; 30(6): 925-939, 2016 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-27866850

RESUMEN

Pro-inflammatory cytokines produced in the tumor microenvironment lead to eradication of anti-tumor immunity and enhanced tumor cell survival. In the current study, we identified tumor necrosis factor alpha (TNF-α) as a major factor triggering cancer cell immunosuppression against T cell surveillance via stabilization of programmed cell death-ligand 1 (PD-L1). We demonstrated that COP9 signalosome 5 (CSN5), induced by NF-κB p65, is required for TNF-α-mediated PD-L1 stabilization in cancer cells. CSN5 inhibits the ubiquitination and degradation of PD-L1. Inhibition of CSN5 by curcumin diminished cancer cell PD-L1 expression and sensitized cancer cells to anti-CTLA4 therapy.


Asunto(s)
Antígeno B7-H1/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , FN-kappa B/metabolismo , Neoplasias/metabolismo , Péptido Hidrolasas/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Antígeno B7-H1/química , Complejo del Señalosoma COP9 , Línea Celular Tumoral , Curcumina/farmacología , Femenino , Humanos , Ratones , Trasplante de Neoplasias , Estabilidad Proteica , Ubiquitinación
18.
J Biol Chem ; 291(37): 19651-60, 2016 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-27471270

RESUMEN

MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression by promoting degradation and/or repressing translation of specific target mRNAs. Several miRNAs have been identified that regulate the amplitude of the innate immune response by directly targeting Toll-like receptor (TLR) pathway members and/or cytokines. miR-33a and miR-33b (the latter present in primates but absent in rodents and lower species) are located in introns of the sterol regulatory element-binding protein (SREBP)-encoding genes and control cholesterol/lipid homeostasis in concert with their host gene products. These miRNAs regulate macrophage cholesterol by targeting the lipid efflux transporters ATP binding cassette (ABC)A1 and ABCG1. We and others have previously reported that Abca1(-/-) and Abcg1(-/-) macrophages have increased TLR proinflammatory responses due to augmented lipid raft cholesterol. Given this, we hypothesized that miR-33 would augment TLR signaling in macrophages via a raft cholesterol-dependent mechanism. Herein, we report that multiple TLR ligands down-regulate miR-33 in murine macrophages. In the case of lipopolysaccharide, this is a delayed, Toll/interleukin-1 receptor (TIR) domain-containing adapter-inducing interferon-ß-dependent response that also down-regulates Srebf-2, the host gene for miR-33. miR-33 augments macrophage lipid rafts and enhances proinflammatory cytokine induction and NF-κB activation by LPS. This occurs through an ABCA1- and ABCG1-dependent mechanism and is reversible by interventions upon raft cholesterol and by ABC transporter-inducing liver X receptor agonists. Taken together, these findings extend the purview of miR-33, identifying it as an indirect regulator of innate immunity that mediates bidirectional cross-talk between lipid homeostasis and inflammation.


Asunto(s)
Transportador 1 de Casete de Unión a ATP/inmunología , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 1/inmunología , Inmunidad Innata , Macrófagos/inmunología , Microdominios de Membrana/inmunología , MicroARNs/inmunología , Transportador 1 de Casete de Unión a ATP/genética , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 1/genética , Animales , Microdominios de Membrana/genética , Ratones , Ratones Noqueados , MicroARNs/genética , Células RAW 264.7 , Proteína 2 de Unión a Elementos Reguladores de Esteroles/genética , Proteína 2 de Unión a Elementos Reguladores de Esteroles/inmunología
19.
Nat Med ; 22(2): 194-201, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26779812

RESUMEN

Poly (ADP-ribose) polymerase (PARP) inhibitors have emerged as promising therapeutics for many diseases, including cancer, in clinical trials. One PARP inhibitor, olaparib (Lynparza, AstraZeneca), was recently approved by the FDA to treat ovarian cancer with mutations in BRCA genes. BRCA1 and BRCA2 have essential roles in repairing DNA double-strand breaks, and a deficiency of BRCA proteins sensitizes cancer cells to PARP inhibition. Here we show that the receptor tyrosine kinase c-Met associates with and phosphorylates PARP1 at Tyr907 (PARP1 pTyr907 or pY907). PARP1 pY907 increases PARP1 enzymatic activity and reduces binding to a PARP inhibitor, thereby rendering cancer cells resistant to PARP inhibition. The combination of c-Met and PARP1 inhibitors synergized to suppress the growth of breast cancer cells in vitro and xenograft tumor models, and we observed similar synergistic effects in a lung cancer xenograft tumor model. These results suggest that the abundance of PARP1 pY907 may predict tumor resistance to PARP inhibitors, and that treatment with a combination of c-Met and PARP inhibitors may benefit patients whose tumors show high c-Met expression and who do not respond to PARP inhibition alone.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Apoptosis/efectos de los fármacos , Neoplasias de la Mama , Proliferación Celular/efectos de los fármacos , Neoplasias Pulmonares , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Poli(ADP-Ribosa) Polimerasas/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-met/antagonistas & inhibidores , Anilidas/farmacología , Animales , Bencimidazoles/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Crizotinib , Humanos , Técnicas In Vitro , Indoles/farmacología , Células MCF-7 , Ratones , Trasplante de Neoplasias , Fosforilación/efectos de los fármacos , Ftalazinas/farmacología , Piperazinas/farmacología , Poli(ADP-Ribosa) Polimerasa-1 , Poli(ADP-Ribosa) Polimerasas/efectos de los fármacos , Pirazoles/farmacología , Piridinas/farmacología , Quinolinas/farmacología , Ensayos Antitumor por Modelo de Xenoinjerto
20.
Biomaterials ; 71: 71-83, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26318818

RESUMEN

Overcoming limitations often experienced in nanomedicine delivery toward hypoxia regions of malignant tumors remains a great challenge. In this study, a promising modality for active hypoxia drug delivery was developed by adopting tumortropic monocytes/macrophages as a cellular vehicle for co-delivery of echogenic polymer/C5F12 bubbles and doxorubicin-loaded polymer vesicles. Through the remote-controlled focused ultrasound (FUS)-triggered drug liberation, therapeutic monocytes show prominent capability of inducing apoptosis of cancer cells. The in vivo and ex vivo fluorescence imaging shows appreciable accumulation of cell-mediated therapeutics in tumor as compared to the nanoparticle counterpart residing mostly in liver. Inhibition of tumor recurrence with γ-ray pre-irradiated Tramp-C1-bearing mice receiving therapeutic monocytes intravenously alongside the FUS activation at tumor site was significantly observed. Immunohistochemical examination of tumor sections confirms successful cellular transport of therapeutic payloads to hypoxic regions and pronounced cytotoxic action against hypoxic cells. Following the intravenous administration, the cellular-mediated therapeutics can penetrate easily to a depth beyond 150 µm from the nearest blood vessels within pre-irradiated tumor while nanoparticles are severely limited to a depth of ca 10-15 µm. This work demonstrates the great promise of cellular delivery to carry therapeutic payloads for improving chemotherapy in hypoxia by combining external trigger for drug release.


Asunto(s)
Antineoplásicos/farmacología , Hipoxia de la Célula/efectos de los fármacos , Monocitos/metabolismo , Neoplasias/patología , Polímeros/química , Animales , Antineoplásicos/química , Antineoplásicos/farmacocinética , Humanos , Ratones , Ratones Endogámicos C57BL , Distribución Tisular
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