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1.
J Biol Chem ; 298(9): 102336, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35931111

RESUMO

Mitochondrial chelatable iron contributes to the severity of several injury processes, including ischemia/reperfusion, oxidative stress, and drug toxicity. However, methods to measure this species in living cells are lacking. To measure mitochondrial chelatable iron in living cells, here we synthesized a new fluorescent indicator, mitoferrofluor (MFF). We designed cationic MFF to accumulate electrophoretically in polarized mitochondria, where a reactive group then forms covalent adducts with mitochondrial proteins to retain MFF even after subsequent depolarization. We also show in cell-free medium that Fe2+ (and Cu2+), but not Fe3+, Ca2+, or other biologically relevant divalent cations, strongly quenched MFF fluorescence. Using confocal microscopy, we demonstrate in hepatocytes that red MFF fluorescence colocalized with the green fluorescence of the mitochondrial membrane potential (ΔΨm) indicator, rhodamine 123 (Rh123), indicating selective accumulation into the mitochondria. Unlike Rh123, mitochondria retained MFF after ΔΨm collapse. Furthermore, intracellular delivery of iron with membrane-permeant Fe3+/8-hydroxyquinoline (FeHQ) quenched MFF fluorescence by ∼80% in hepatocytes and other cell lines, which was substantially restored by the membrane-permeant transition metal chelator pyridoxal isonicotinoyl hydrazone. We also show FeHQ quenched the fluorescence of cytosolically coloaded calcein, another Fe2+ indicator, confirming that Fe3+ in FeHQ undergoes intracellular reduction to Fe2+. Finally, MFF fluorescence did not change after addition of the calcium mobilizer thapsigargin, which shows MFF is insensitive to physiologically relevant increases of mitochondrial Ca2+. In conclusion, the new sensor reagent MFF fluorescence is an indicator of mitochondrial chelatable Fe2+ in normal hepatocytes with polarized mitochondria as well as in cells undergoing loss of ΔΨm.


Assuntos
Corantes Fluorescentes , Quelantes de Ferro , Mitocôndrias , Animais , Cálcio/metabolismo , Cátions Bivalentes/análise , Células Cultivadas , Fluorescência , Corantes Fluorescentes/química , Quelantes de Ferro/análise , Camundongos , Mitocôndrias/química , Proteínas Mitocondriais/química , Oxiquinolina/química , Rodamina 123 , Tapsigargina/farmacologia
2.
Cancers (Basel) ; 13(9)2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-34062962

RESUMO

Polyploid giant cancer cells (PGCC) constitute a transiently senescent subpopulation of cancer cells that arises in response to stress. PGCC are capable of generating progeny via a primitive, cleavage-like cell division that is dependent on the sphingolipid enzyme acid ceramidase (ASAH1). The goal of this study was to understand differences in sphingolipid metabolism between non-polyploid and polyploid cancer cells to gain an understanding of the ASAH1-dependence in the PGCC population. Steady-state and flux analysis of sphingolipids did not support our initial hypothesis that the ASAH1 product sphingosine is rapidly converted into the pro-survival lipid sphingosine-1-phosphate. Instead, our results suggest that ASAH1 activity is important for preventing the accumulation of long chain ceramides such as C16-ceramide. We therefore determined how modulation of C16-ceramide, either through CerS6 or p53, a known PGCC suppressor and enhancer of CerS6-derived C16-ceramide, affected PGCC progeny formation. Co-expression of the CerS6 and p53 abrogated the ability of PGCC to form offspring, suggesting that the two genes form a positive feedback loop. CerS6 enhanced the effect of p53 by significantly increasing protein half-life. Our results support the idea that sphingolipid metabolism is of functional importance in PGCC and that targeting this signaling pathway has potential for clinical intervention.

3.
Methods Mol Biol ; 2277: 423-431, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34080166

RESUMO

Intracellular Ca2+ is strictly regulated to maintain optimal levels for function of cellular organelles as well as mitochondrial respiratory signaling at the tricarboxylic acid cycle and electron transport chain level. Optimal Ca2+ concentration for these processes vary between cell types. Furthermore, exposure of mitochondria to sustained, elevated levels of Ca2+ induces mitochondrial Ca2+ overload and damage to mitochondrial oxidative phosphorylation and ATP production. Isolated mitochondria are widely used to study mitochondrial physiology and drug effects on mitochondrial metabolism and respiratory function. However, isolated mitochondria are easily damaged during the mitochondrial isolation process. The present article describes a mitochondrial isolation method using Ca2+-chelation to minimize mitochondrial damage. We follow up the isolation process with an application that requires an optimized buffer Ca2+ concentration: the characterization of their respiratory function using a high-resolution respirometric assay.


Assuntos
Técnicas Citológicas/métodos , Mitocôndrias/metabolismo , Biologia Molecular/métodos , Epitélio Pigmentado da Retina/citologia , Trifosfato de Adenosina/metabolismo , Quelantes de Cálcio/farmacologia , Técnicas de Cultura de Células/instrumentação , Técnicas de Cultura de Células/métodos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Biologia Molecular/instrumentação , Epitélio Pigmentado da Retina/efeitos dos fármacos
4.
J Ocul Pharmacol Ther ; 37(6): 367-378, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33945330

RESUMO

Purpose: Metabolic stress and associated mitochondrial dysfunction are implicated in retinal degeneration irrespective of the underlying cause. We identified seven unique chemicals from a Chembridge DiverSET screen and tested their protection against photoreceptor cell death in cell- and animal-based approaches. Methods: Calcium overload (A23187) was triggered in 661W murine photoreceptor-derived cells, and changes in redox potential and real-time changes in cellular metabolism were assessed using the MTT and Seahorse Biosciences XF assay, respectively. Cheminformatics to compare structures, and biodistribution in the living pig eye aided in selection of the lead compound. In-situ, retinal organ cultures of rd1 mouse and S334ter-line-3 rat were tested, in-vivo the light-induced retinal degeneration in albino Balb/c mice was used, assessing photoreceptor cell numbers histologically. Results: Of the seven chemicals, six were protective against A23187- and IBMX-induced loss of mitochondrial capacity, as measured by viability and respirometry in 661W cells. Cheminformatic analyses identified a unique pharmacophore with 6 physico-chemical features based on two compounds (CB11 and CB12). The protective efficacy of CB11 was further shown by reducing photoreceptor cell loss in retinal explants from two retinitis pigmentosa rodent models. Using eye drops, CB11 targeting to the pig retina was confirmed. The same eye drops decreased photoreceptor cell loss in light-stressed Balb/c mice. Conclusions: New chemicals were identified that protect from mitochondrial damage and lead to improved mitochondrial function. Using ex-vivo and in-vivo models, CB11 decreased the loss of photoreceptor cells in murine models of retinal degeneration and may be effective as treatment for different retinal dystrophies.


Assuntos
Modelos Animais de Doenças , Mitocôndrias/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Células Fotorreceptoras Retinianas Cones/efeitos dos fármacos , Degeneração Retiniana/complicações , Retinose Pigmentar/prevenção & controle , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Camundongos , Camundongos Endogâmicos BALB C , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Células Fotorreceptoras Retinianas Cones/metabolismo , Células Fotorreceptoras Retinianas Cones/patologia , Retinose Pigmentar/etiologia , Retinose Pigmentar/patologia
5.
Mol Vis ; 27: 151-160, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33907370

RESUMO

PURPOSE: Recent reports linking HDAC6 to mitochondrial turnover and neurodegeneration led us to hypothesize that an inhibitor such as Vorinostat (suberoylanilide hydroxamic acid, SAHA) may reduce mitochondrial damage found in retinitis pigmentosa (RP), a progressive neurodegenerative disease of the eye. Here we tested the efficacy of SAHA for its ability to protect photoreceptors in in-vitro and in-situ models of RP. As the stressor, we focused on calcium overload. Calcium is one of the main drivers of cell death, and is associated with rod loss in the rd1 mouse retina, which harbors a mutation in the Pde6b gene similar to that found in human patients suffering from autosomal recessive RP. METHOD: Murine photoreceptor cell line (661W) were exposed to agents that led to calcium stress. Cell survival and redox capacity were measured using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, real-time changes in cellular metabolism were assessed using the Seahorse Biosciences XF24 analyzer, and mitochondrial fission-fusion using imaging. In-situ, neuroprotection was assessed in RPE/retina organ cultures of the rd1 mouse. SAHA effects on cell survival were compared in 661W cells with those of the specific HDAC6 inhibitor tubastatin A, and those on protein acetylation by Western blotting. RESULTS: In stressed 661W cells, SAHA was found to increase cell survival that was associated with improved mitochondrial respiration and reduced mitochondrial fission. The protective effects of SAHA were also observed on photoreceptor cell survival in whole retinal organ explants of the rd1 mouse. Even though tubastatin A was ineffective in increasing cell survival in 661W cells, HDAC6 activity was confirmed in 661W cells after SAHA treatment with protein acetylation specific for HDAC6, defined by an increase in tubulin, but not histone acetylation. CONCLUSIONS: SAHA was found to protect mitochondria from damage, and concomitantly reduced photoreceptor cell death in cell and organ cultures. The lack of activity of tubastatin A suggests that there must be an additional mechanism of action involved in the protective mechanism of SAHA that is responsible for its neuroprotection. Overall, SAHA may be a useful treatment for the prevention of photoreceptor degeneration associated with human RP. The results are discussed in the context of the effects of inhibitors that target different classes and members of the HDAC family and their effects on rod versus cone survival.


Assuntos
Modelos Animais de Doenças , Inibidores de Histona Desacetilases/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Retinose Pigmentar/tratamento farmacológico , Vorinostat/uso terapêutico , Animais , Western Blotting , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Camundongos , Mitocôndrias/efeitos dos fármacos , Doenças Mitocondriais/prevenção & controle , NADH NADPH Oxirredutases/metabolismo , Técnicas de Cultura de Órgãos , Células Fotorreceptoras de Vertebrados/efeitos dos fármacos , Retinose Pigmentar/metabolismo , Retinose Pigmentar/patologia
6.
Front Immunol ; 12: 628062, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33746964

RESUMO

Complement component 3 fragment C3a is an anaphylatoxin involved in promoting cellular responses important in immune response and host defense. Its receptor (C3a receptor, C3aR) is distributed on the plasma membrane; however, lysosomal localization in immune cells has been reported. Oxidative stress increases intracellular reactive oxygen species (ROS), and ROS activate complement signaling in immune cells and metabolic reprogramming. Here we tested oxidative stress and intracellular complement in mitochondrial dysfunction in RPE cells using high resolution live-cell imaging, and metabolism analysis in isolated mitochondria using Seahorse technology. While C3aR levels were unaffected by oxidative stress, its cell membrane levels decreased and mitochondrial (mt) localization increased. Trafficking was dependent on endocytosis, utilizing endosomal-to-mitochondrial cargo transfer. H2O2-treatment also increased C3a-mtC3aR co-localization dose-dependently. In isolated mitochondria from H2O2-treated cells C3a increased mitochondrial Ca2+ uptake, that could be inhibited by C3aR antagonism (SB290157), mitochondrial Ca2+ uniporter blocker (Ru360), and Gαi-protein inhibition (pertussis toxin, PTX); and inhibited mitochondrial repiration in an SB290157- and PTX-dependent manner. Specifically, mtC3aR activation inhibited state III ADP-driven respiration and maximal respiratory capacity. Mitochondria from control cells did not respond to C3a. Furthermore, transmitochondrial cybrid ARPE-19 cells harboring J haplogroup mitochondria that confer risk for age-related macular degeneration, showed high levels of mtC3aR and reduced ATP production upon C3a stimulation. Our findings suggest that oxidative stress increases mtC3aR, leading to altered mitochondrial calcium uptake and ATP production. These studies will have important implication in our understanding on the balance of extra- and intracellular complement signaling in controlling cellular health and dysfunction.


Assuntos
Metabolismo Energético , Células Epiteliais/metabolismo , Mitocôndrias/metabolismo , Estresse Oxidativo , Receptores de Complemento/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Trifosfato de Adenosina/metabolismo , Cálcio/metabolismo , Linhagem Celular , Respiração Celular , Endocitose , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/imunologia , Humanos , Peróxido de Hidrogênio/toxicidade , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/imunologia , Estresse Oxidativo/efeitos dos fármacos , Transporte Proteico , Receptores de Complemento/genética , Epitélio Pigmentado da Retina/efeitos dos fármacos , Epitélio Pigmentado da Retina/imunologia
7.
Front Pharmacol ; 11: 577, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32457608

RESUMO

Gynecologic cancers are among the most lethal cancers found in women, and, advanced stage cancers are still a treatment challenge. Ion channels are known to contribute to cellular homeostasis in all cells and mounting evidence indicates that ion channels could be considered potential therapeutic targets against cancer. Nevertheless, the pharmacologic effect of targeting ion channels in cancer is still understudied. We found that the expression of Kir6.2/SUR2 potassium channel is a potential favorable prognostic factor in gynecologic cancers. Also, pharmacological stimulation of the Kir6.2/SUR2 channel activity with the selective activator molecule minoxidil arrests tumor growth in a xenograft model of ovarian cancer. Investigation on the mechanism linking the Kir6.2/SUR2 to tumor growth revealed that minoxidil alters the metabolic and oxidative state of cancer cells by producing mitochondrial disruption and extensive DNA damage. Consequently, application of minoxidil results in activation of a caspase-3 independent cell death pathway. Our data show that repurposing of FDA approved K+ channel activators may represent a novel, safe adjuvant therapeutic approach to traditional chemotherapy for the treatment of gynecologic cancers.

8.
Nat Biomed Eng ; 4(4): 446-462, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32284552

RESUMO

Environmental factors are the largest contributors to cardiovascular disease. Here we show that cardiac organoids that incorporate an oxygen-diffusion gradient and that are stimulated with the neurotransmitter noradrenaline model the structure of the human heart after myocardial infarction (by mimicking the infarcted, border and remote zones), and recapitulate hallmarks of myocardial infarction (in particular, pathological metabolic shifts, fibrosis and calcium handling) at the transcriptomic, structural and functional levels. We also show that the organoids can model hypoxia-enhanced doxorubicin cardiotoxicity. Human organoids that model diseases with non-genetic pathological factors could help with drug screening and development.


Assuntos
Avaliação Pré-Clínica de Medicamentos/métodos , Coração/efeitos dos fármacos , Modelos Cardiovasculares , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Organoides/efeitos dos fármacos , Cardiotoxicidade/metabolismo , Cardiotoxicidade/patologia , Desenvolvimento de Medicamentos , Humanos , Infarto do Miocárdio/induzido quimicamente , Infarto do Miocárdio/genética , Organoides/metabolismo , Organoides/patologia , Oxigênio/metabolismo
9.
Cell Rep ; 28(7): 1879-1893.e7, 2019 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-31412253

RESUMO

Sphingosine 1-phosphate (S1P), a bioactive lysophospholipid generated by sphingosine kinase 1 (SphK1), regulates lymphocyte egress into circulation via S1P receptor 1 (S1PR1) signaling, and it controls the differentiation of regulatory T cells (Tregs) and T helper-17 cells. However, the mechanisms by which receptor-independent SphK1-mediated intracellular S1P levels modulate T cell functionality remains unknown. We show here that SphK1-deficient T cells maintain central memory phenotype and exhibit higher mitochondrial respiration and reduced differentiation to Tregs. Mechanistically, we discovered a direct correlation between SphK1-generated S1P and lipid transcription factor PPARγ (peroxisome proliferator-activated receptor gamma) activity, which in turn regulates lipolysis in T cells. Genetic and pharmacologic inhibition of SphK1 improved metabolic fitness and anti-tumor activity of T cells against murine melanoma. Further, inhibition of SphK1 and PD1 together led to improved control of melanoma. Overall, these data highlight the clinical potential of limiting SphK1/S1P signaling for enhancing anti-tumor-adoptive T cell therapy.


Assuntos
Reprogramação Celular , Regulação Neoplásica da Expressão Gênica , Lisofosfolipídeos/metabolismo , Melanoma Experimental/patologia , PPAR gama/fisiologia , Fosfotransferases (Aceptor do Grupo Álcool)/fisiologia , Esfingosina/análogos & derivados , Linfócitos T/imunologia , Animais , Feminino , Masculino , Melanoma Experimental/imunologia , Melanoma Experimental/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosforilação Oxidativa , Receptores de Lisoesfingolipídeo/metabolismo , Transdução de Sinais , Esfingosina/metabolismo , Linfócitos T/metabolismo
10.
Sci Rep ; 9(1): 6790, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31043635

RESUMO

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

11.
FASEB J ; 33(7): 8186-8201, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30951369

RESUMO

Statins, widely used to treat hypercholesterolemia, inhibit the 3-hydroxy-3-methylglutaryl-coenzyme A reductase, the rate-limiting enzyme of de novo cholesterol (Chol) synthesis. Statins have been also reported to slow tumor progression. In cancer cells, ATP is generated both by glycolysis and oxidative phosphorylation. Mitochondrial membrane potential (ΔΨ), a readout of mitochondrial metabolism, is sustained by the oxidation of respiratory substrates in the Krebs cycle to generate NADH and flavin adenine dinucleotide, which are further oxidized by the respiratory chain. Here, we studied the short-term effects of statins (3-24 h) on mitochondrial metabolism on cancer cells. Lovastatin (LOV) and simvastatin (SIM) increased ΔΨ in HepG2 and Huh7 human hepatocarcinoma cells and HCC4006 human lung adenocarcinoma cells. Mitochondrial hyperpolarization after LOV and SIM was dose and time dependent. Maximal increase in ΔΨ occurred at 10 µM and 24 h for both statins. The structurally unrelated atorvastatin also hyperpolarized mitochondria in HepG2 cells. Cellular and mitochondrial Chol remained unchanged after SIM. Both LOV and SIM decreased basal respiration, ATP-linked respiration, and ATP production. LOV and SIM did not change the rate of lactic acid production. In summary, statins modulate mitochondrial metabolism in cancer cells independently of the Chol content in cellular membranes without affecting glycolysis.-Christie, C. F., Fang, D., Hunt, E. G., Morris, M. E., Rovini, A., Heslop, K. A., Beeson, G. C., Beeson, C. C., Maldonado, E. N. Statin-dependent modulation of mitochondrial metabolism in cancer cells is independent of cholesterol content.


Assuntos
Adenocarcinoma de Pulmão/metabolismo , Carcinoma Hepatocelular/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Neoplasias Hepáticas/metabolismo , Lovastatina/farmacologia , Neoplasias Pulmonares/metabolismo , Mitocôndrias Hepáticas/metabolismo , Sinvastatina/farmacologia , Adenocarcinoma de Pulmão/tratamento farmacológico , Adenocarcinoma de Pulmão/patologia , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/patologia , Células Hep G2 , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias Hepáticas/patologia
12.
Anal Biochem ; 577: 52-58, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31022379

RESUMO

Optimum cytosolic calcium concentrations support balanced mitochondrial respiration. However, cytosolic Ca2+ concentrations vary among cell types and excess Ca2+ can cause mitochondrial dysfunction. We optimized an isolation protocol to eliminate excess Ca2+ and thereby minimizing structural damage. Ca2+ uptake was monitored by measuring mitochondrial Ca2+-dependent PKA activity using cAMP ELISAs, and O2 consumption levels during mitochondrial respiration using high-resolution respirometry. 3 nM Ca2+ was found to increase cAMP levels and produce optimal state III respiration. Hence, optimized isolation of mitochondria from cell lines using calcium denudation provides the best platform for the study of Ca2+-dependent regulation of mitochondrial signaling.


Assuntos
Cálcio , Mitocôndrias/metabolismo , Cálcio/análise , Cálcio/metabolismo , Sinalização do Cálcio , Linhagem Celular , AMP Cíclico/metabolismo , Citosol/química , Humanos , Oxigênio/metabolismo
13.
Nat Commun ; 10(1): 1296, 2019 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-30899002

RESUMO

The dysregulation of Fbxo4-cyclin D1 axis occurs at high frequency in esophageal squamous cell carcinoma (ESCC), where it promotes ESCC development and progression. However, defining a therapeutic vulnerability that results from this dysregulation has remained elusive. Here we demonstrate that Rb and mTORC1 contribute to Gln-addiction upon the dysregulation of the Fbxo4-cyclin D1 axis, which leads to the reprogramming of cellular metabolism. This reprogramming is characterized by reduced energy production and increased sensitivity of ESCC cells to combined treatment with CB-839 (glutaminase 1 inhibitor) plus metformin/phenformin. Of additional importance, this combined treatment has potent efficacy in ESCC cells with acquired resistance to CDK4/6 inhibitors in vitro and in xenograft tumors. Our findings reveal a molecular basis for cancer therapy through targeting glutaminolysis and mitochondrial respiration in ESCC with dysregulated Fbxo4-cyclin D1 axis as well as cancers resistant to CDK4/6 inhibitors.


Assuntos
Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias Esofágicas/tratamento farmacológico , Carcinoma de Células Escamosas do Esôfago/tratamento farmacológico , Regulação Neoplásica da Expressão Gênica , Glutamina/metabolismo , Hipoglicemiantes/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Animais , Benzenoacetamidas/farmacologia , Linhagem Celular Tumoral , Ciclina D1/genética , Ciclina D1/metabolismo , Quinase 4 Dependente de Ciclina/antagonistas & inibidores , Quinase 4 Dependente de Ciclina/genética , Quinase 4 Dependente de Ciclina/metabolismo , Quinase 6 Dependente de Ciclina/antagonistas & inibidores , Quinase 6 Dependente de Ciclina/genética , Quinase 6 Dependente de Ciclina/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Sinergismo Farmacológico , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/genética , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/genética , Carcinoma de Células Escamosas do Esôfago/metabolismo , Carcinoma de Células Escamosas do Esôfago/patologia , Proteínas F-Box/genética , Proteínas F-Box/metabolismo , Glutaminase/antagonistas & inibidores , Glutaminase/genética , Glutaminase/metabolismo , Glutamina/antagonistas & inibidores , Humanos , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Metformina/farmacologia , Camundongos , Terapia de Alvo Molecular , Fenformin/farmacologia , Proteína do Retinoblastoma/genética , Proteína do Retinoblastoma/metabolismo , Transdução de Sinais , Tiadiazóis/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
15.
J Pharmacol Exp Ther ; 369(1): 173-180, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30709866

RESUMO

Acute kidney injury (AKI) is the rapid loss of renal function after an insult, and renal proximal tubule cells (RPTCs) are central to the pathogenesis of AKI. The ß 2-adrenergic receptor (ß 2AR) agonist formoterol accelerates the recovery of renal function in mice after ischemia-reperfusion injury (IRI) with associated rescue of mitochondrial proteins; however, the cell type responsible for this recovery remains unknown. The role of RPTCs in formoterol-induced recovery of renal function was assessed in a proximal tubule-specific knockout of the ß 2AR (γGT-Cre:ADRB2Flox/Flox). These mice and wild-type controls (ADRB2Flox/Flox) were subjected to renal IRI, followed by once-daily dosing of formoterol beginning 24 hours post-IRI and euthanized at 144 hours. Compared with ADRB2Flox/Flox mice, γGT-Cre:ADRB2Flox/Flox mice had decreased renal cortical mRNA expression of the ß 2AR. After IRI, formoterol treatment restored renal function in ADRB2Flox/Flox but not γGT-Cre:ADRB2Flox/Flox mice as measured by serum creatinine, histopathology, and expression of kidney injury marker-1 (KIM-1). Formoterol-treated ADRB2Flox/Flox mice exhibited recovery of mitochondrial proteins and DNA copy number, whereas γGT-Cre:ADRB2Flox/Flox mice treated with formoterol did not. Analysis of mitochondrial morphology by transmission electron microscopy demonstrated that formoterol increased mitochondrial number and density in ADRB2Flox/Flox mice but not in γGT-Cre:ADRB2Flox/Flox mice. These data demonstrate that proximal tubule ß 2AR regulates renal mitochondrial homeostasis. Formoterol accelerates the recovery of renal function after AKI by activating proximal tubule ß 2AR to induce mitochondrial biogenesis and demonstrates the overall requirement of RPTCs in renal recovery.


Assuntos
Fumarato de Formoterol/farmacologia , Túbulos Renais Proximais/efeitos dos fármacos , Túbulos Renais Proximais/fisiopatologia , Mitocôndrias/efeitos dos fármacos , Receptores Adrenérgicos beta 2/metabolismo , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/fisiopatologia , Animais , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , Masculino , Camundongos , Mitocôndrias/patologia , Recuperação de Função Fisiológica/efeitos dos fármacos , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais/efeitos dos fármacos
16.
Clin Cancer Res ; 25(3): 1036-1049, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30327305

RESUMO

PURPOSE: Adoptive T-cell therapy (ACT) of cancer, which involves the infusion of ex vivo-engineered tumor epitope reactive autologous T cells into the tumor-bearing host, is a potential treatment modality for cancer. However, the durable antitumor response following ACT is hampered either by loss of effector function or survival of the antitumor T cells. Therefore, strategies to improve the persistence and sustain the effector function of the antitumor T cells are of immense importance. Given the role of metabolism in determining the therapeutic efficacy of T cells, we hypothesize that inhibition of PIM kinases, a family of serine/threonine kinase that promote cell-cycle transition, cell growth, and regulate mTORC1 activity, can improve the potency of T cells in controlling tumor. EXPERIMENTAL DESIGN: The role of PIM kinases in T cells was studied either by genetic ablation (PIM1-/-PIM2-/-PIM3-/-) or its pharmacologic inhibition (pan-PIM kinase inhibitor, PimKi). Murine melanoma B16 was established subcutaneously and treated by transferring tumor epitope gp100-reactive T cells along with treatment regimen that involved inhibiting PIM kinases, anti-PD1 or both. RESULTS: With inhibition of PIM kinases, T cells had significant reduction in their uptake of glucose, and upregulated expression of memory-associated genes that inversely correlate with glycolysis. In addition, the expression of CD38, which negatively regulates the metabolic fitness of the T cells, was also reduced in PimKi-treated cells. Importantly, the efficacy of antitumor T-cell therapy was markedly improved by inhibiting PIM kinases in tumor-bearing mice receiving ACT, and further enhanced by adding anti-PD1 antibody to this combination. CONCLUSIONS: This study highlights the potential therapeutic significance of combinatorial strategies where ACT and inhibition of signaling kinase with checkpoint blockade could improve tumor control.


Assuntos
Compostos de Bifenilo/farmacologia , Imunoterapia Adotiva/métodos , Neoplasias Experimentais/terapia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-pim-1/antagonistas & inibidores , Linfócitos T/imunologia , Tiazolidinas/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , Animais , Anticorpos/imunologia , Anticorpos/farmacologia , Linhagem Celular Tumoral , Humanos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/metabolismo , Receptor de Morte Celular Programada 1/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-pim-1/genética , Proteínas Proto-Oncogênicas c-pim-1/metabolismo , Linfócitos T/metabolismo , Resultado do Tratamento
17.
Cell Rep ; 25(6): 1469-1484.e5, 2018 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-30404003

RESUMO

Patients with mtDNA depletion syndrome 3 (MTDPS3) often die as children from liver failure caused by severe reduction in mtDNA content. The identification of treatments has been impeded by an inability to culture and manipulate MTDPS3 primary hepatocytes. Here we generated DGUOK-deficient hepatocyte-like cells using induced pluripotent stem cells (iPSCs) and used them to identify drugs that could improve mitochondrial ATP production and mitochondrial function. Nicotinamide adenine dinucleotide (NAD) was found to improve mitochondrial function in DGUOK-deficient hepatocyte-like cells by activating the peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α). NAD treatment also improved ATP production in MTDPS3-null rats and in hepatocyte-like cells that were deficient in ribonucleoside-diphosphate reductase subunit M2B (RRM2B), suggesting that it could be broadly effective. Our studies reveal that DGUOK-deficient iPSC-derived hepatocytes recapitulate the pathophysiology of MTDPS3 in culture and can be used to identify therapeutics for mtDNA depletion syndromes.


Assuntos
DNA Mitocondrial/genética , Hepatócitos/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , NAD/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Sequência de Bases , Diferenciação Celular , Respiração Celular , Feminino , Glucose/metabolismo , Glicólise , Hepatócitos/citologia , Hepatócitos/ultraestrutura , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Masculino , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Mutação/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Ratos , Ribonucleotídeo Redutases/metabolismo , Síndrome
18.
Am J Physiol Renal Physiol ; 315(4): F1119-F1128, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-29846105

RESUMO

Our laboratory previously reported that agonists of the 5-hydoxytryptamine 1F (5-HT1F) receptor induce renal mitochondrial biogenesis (MB) and that stimulation of the 5-HT1F receptor following ischemia/reperfusion (I/R)-induced acute kidney injury (AKI) accelerated the recovery of renal function in mice. The goal of this study was to examine the contribution of the 5-HT1F receptor in the regulation of renal mitochondrial homeostasis and renal function in naïve and injured mice. Although 5-HT1F receptor knockout (KO) mice were healthy and fertile, and did not exhibit renal dysfunction, renal mitochondrial DNA copy number and mitochondrial fission gene expression increased at 10 wk of age. The 5-HT1F receptor KO mice exhibited greater proximal tubular injury and diminished renal recovery after I/R-induced AKI compared with wild-type mice. These findings were associated with persistent suppression of renal cortical MB and ATP levels after injury. In summary, the 5-HT1F receptor is a component of physiological MB regulation in the kidney, and its absence potentiates renal injury and impedes recovery.


Assuntos
Injúria Renal Aguda/metabolismo , Homeostase/fisiologia , Mitocôndrias/metabolismo , Receptores de Serotonina/metabolismo , Animais , DNA Mitocondrial/metabolismo , Rim/metabolismo , Córtex Renal/metabolismo , Masculino , Camundongos Knockout , Biogênese de Organelas , Receptores de Serotonina/genética , Traumatismo por Reperfusão/metabolismo , Receptor 5-HT1F de Serotonina
19.
Mol Neurobiol ; 55(1): 267-275, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28889362

RESUMO

Myelin basic protein (MBP) is a major target of T cells in lesions of multiple sclerosis (MS) patients and its animal model, experimental autoimmune encephalomyelitis (EAE). Interactions between the major histocompatibility complex II containing antigenic peptides and the T cell receptor activate CD4+ T cells that perpetuate EAE and MS. Previously reported data has shown that treating with an altered peptide ligand (APL) in which the normal antigenic peptide sequence of MBP has been slightly changed at T cell contact positions is helpful in reducing disease in both rodents and humans. The use of natural peptides, which are susceptible to protease degradation, requires high concentrations that can create hypersensitivity reactions. Our hypothesis is that APL containing aza substitutions, CH(R)-N- > N(R)N, could lead to improved protease resistance, reduced clinical disease scores, and a shift in T cell profile. In this study, several aza-APLs and control peptides were synthesized and screened for the best aza-APL candidate (3aza-APL) based on dissociation half time from major histocompatibility complex (MHC) class II, induction of IL-2 response, and resistance to degradation by proteases. The efficacy was then tested in vivo. Results indicate that 3aza-APL is superior to currently available APLs in terms of protease resistance and disease suppression in EAE mice. The 3aza-APL induced anti-inflammatory immune responses by altering key transcription factors and cytokine genes which regulate T cell subpopulations. These data suggest that the novel 3aza-APL has increased protease resistance property and is effective in reducing clinical and physiological signs of disease in EAE animals.


Assuntos
Compostos Aza/administração & dosagem , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/metabolismo , Proteína Básica da Mielina/administração & dosagem , Animais , Linhagem Celular , Encefalomielite Autoimune Experimental/patologia , Masculino , Camundongos , Resultado do Tratamento
20.
Cell Metab ; 27(1): 85-100.e8, 2018 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-29129787

RESUMO

Heightened effector function and prolonged persistence, the key attributes of Th1 and Th17 cells, respectively, are key features of potent anti-tumor T cells. Here, we established ex vivo culture conditions to generate hybrid Th1/17 cells, which persisted long-term in vivo while maintaining their effector function. Using transcriptomics and metabolic profiling approaches, we showed that the enhanced anti-tumor property of Th1/17 cells was dependent on the increased NAD+-dependent activity of the histone deacetylase Sirt1. Pharmacological or genetic inhibition of Sirt1 activity impaired the anti-tumor potential of Th1/17 cells. Importantly, T cells with reduced surface expression of the NADase CD38 exhibited intrinsically higher NAD+, enhanced oxidative phosphorylation, higher glutaminolysis, and altered mitochondrial dynamics that vastly improved tumor control. Lastly, blocking CD38 expression improved tumor control even when using Th0 anti-tumor T cells. Thus, strategies targeting the CD38-NAD+ axis could increase the efficacy of anti-tumor adoptive T cell therapy.


Assuntos
ADP-Ribosil Ciclase 1/metabolismo , Imunoterapia , NAD/metabolismo , Neoplasias/imunologia , Neoplasias/terapia , Linfócitos T/imunologia , Animais , Proteína Forkhead Box O1/metabolismo , Glutamina/metabolismo , Camundongos Endogâmicos C57BL , Neoplasias/metabolismo , Sirtuína 1/metabolismo , Células Th1/imunologia , Células Th17/imunologia
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