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1.
Hepatology ; 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38377458

RESUMO

BACKGROUND AND AIMS: Apoptosis Signal-regulating Kinase 1 (ASK1) is activated by various pathological stimuli and induces cell apoptosis through downstream p38 activation. We studied the effect of pharmacological ASK1 inhibition on cirrhosis and its sequelae using comprehensive preclinical in vivo and in vitro systems. APPROACH AND RESULTS: Short-term (4-6 wk) and long-term (24-44 wk) ASK1 inhibition using small molecule GS-444217 was tested in thioacetamide-induced and BALB/c. Mdr2-/- murine models of cirrhosis and HCC, and in vitro using primary hepatocyte cell death assays. Short-term GS-444217 therapy in both models strongly reduced phosphorylated p38, hepatocyte death, and fibrosis by up to 50%. Profibrogenic release of mitochondrial DAMP mitochondrial deoxyribonucleic acid from dying hepatocytes was blocked by ASK1 or p38 inhibition. Long-term (24 wk) therapy in BALBc.Mdr2 - / - model resulted in a moderate 25% reduction in bridging fibrosis, but not in net collagen deposition. Despite this, the development of cirrhosis was effectively prevented, with strongly reduced p21 + hepatocyte staining (by 72%), serum ammonia levels (by 46%), and portal pressure (average 6.07 vs. 8.53 mm Hg in controls). Extended ASK1 inhibition for 44 wk in aged BALB/c. Mdr2-/- mice resulted in markedly reduced tumor number and size by ~50% compared to the control group. CONCLUSIONS: ASK1 inhibition suppresses the profibrogenic release of mitochondrial deoxyribonucleic acid from dying hepatocytes in a p38-dependent manner and protects from liver fibrosis. Long-term ASK1 targeting resulted in diminished net antifibrotic effect, but the progression to liver cirrhosis and cancer in BALBc/ Mdr2- / - mice was effectively inhibited. These data support the clinical evaluation of ASK1 inhibitors in fibrotic liver diseases.

2.
J Pharmacol Exp Ther ; 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38409114

RESUMO

The farnesoid X receptor (FXR) is a nuclear receptor that controls bile acid, lipid, and cholesterol metabolism. FXR-targeted drugs have shown promise in late-stage clinical trials for non-alcoholic steatohepatitis. Herein, we used clinical results from our first non-steroidal FXR agonist, Px-102 (4-[2-[2-chloro-4-[[5-cyclopropyl-3-(2,6-dichlorophenyl)-4-isoxazolyl]methoxy]phenyl]cyclopropyl] benzoic acid), to develop cilofexor, a potent, non-steroidal FXR agonist with a more manageable safety profile. Px-102 demonstrated the anticipated pharmacodynamic (PD) effects in healthy volunteers but caused a 2-fold increase in alanine aminotransferase (ALT) activity and changes in cholesterol levels. These data guided development of a high fat diet mouse model to screen FXR agonists based on ALT and cholesterol changes. Cilofexor was identified to elicit only minor changes in these parameters. The differing effects of cilofexor and Px-102 on ALT/cholesterol in the model could not be explained by potency or specificity, and we hypothesized that the relative contribution of intestinal and liver FXR activation may be responsible. Gene expression analysis from rodent studies revealed that cilofexor, but not Px-102, had a bias for FXR transcriptional activity in the intestine compared to the liver. Fluorescent imaging in hepatoma cells demonstrated similar subcellular localization for cilofexor and Px-102, but cilofexor was more rapidly washed out, consistent with a lower membrane residence time contributing to reduced hepatic transcriptional effects. Cilofexor demonstrated antisteatotic and antifibrotic efficacy in rodent models and antisteatotic efficacy in a monkey model, with the anticipated PD and a manageable safety profile in human phase I studies. Significance Statement FXR (farnesoid X receptor) agonists have shown promise in treating non-alcoholic steatohepatitis and other liver diseases in the clinic, but balancing efficacy with undesired side effects has been difficult. Here, we examined the preclinical and clinical effects of the first-generation FXR agonist, Px-102 (4-[2-[2-chloro-4-[[5-cyclopropyl-3-(2,6-dichlorophenyl)-4-isoxazolyl]methoxy]phenyl]cyclopropyl] benzoic acid), to enable the selection of an analog, cilofexor, with unique properties that reduced side effects yet maintained efficacy. Cilofexor is one of few remaining FXR agonists in clinical development.

3.
Am J Respir Crit Care Med ; 197(3): 373-385, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-28910144

RESUMO

RATIONALE: Progression of pulmonary arterial hypertension (PAH) is associated with pathological remodeling of the pulmonary vasculature and the right ventricle (RV). Oxidative stress drives the remodeling process through activation of MAPKs (mitogen-activated protein kinases), which stimulate apoptosis, inflammation, and fibrosis. OBJECTIVES: We investigated whether pharmacological inhibition of the redox-sensitive apical MAPK, ASK1 (apoptosis signal-regulating kinase 1), can halt the progression of pulmonary vascular and RV remodeling. METHODS: A selective, orally available ASK1 inhibitor, GS-444217, was administered to two preclinical rat models of PAH (monocrotaline and Sugen/hypoxia), a murine model of RV pressure overload induced by pulmonary artery banding, and cellular models. MEASUREMENTS AND MAIN RESULTS: Oral administration of GS-444217 dose dependently reduced pulmonary arterial pressure and reduced RV hypertrophy in PAH models. The therapeutic efficacy of GS-444217 was associated with reduced ASK1 phosphorylation, reduced muscularization of the pulmonary arteries, and reduced fibrotic gene expression in the RV. Importantly, efficacy was observed when GS-444217 was administered to animals with established disease and also directly reduced cardiac fibrosis and improved cardiac function in a model of isolated RV pressure overload. In cellular models, GS-444217 reduced phosphorylation of p38 and JNK (c-Jun N-terminal kinase) induced by adenoviral overexpression of ASK1 in rat cardiomyocytes and reduced activation/migration of primary mouse cardiac fibroblasts and human pulmonary adventitial fibroblasts derived from patients with PAH. CONCLUSIONS: ASK1 inhibition reduced pathological remodeling of the pulmonary vasculature and the right ventricle and halted progression of pulmonary hypertension in rodent models. These preclinical data inform the first description of a causal role of ASK1 in PAH disease pathogenesis.


Assuntos
Hipertensão Pulmonar/tratamento farmacológico , Hipertrofia Ventricular Direita/prevenção & controle , MAP Quinase Quinase Quinase 5/administração & dosagem , MAP Quinase Quinase Quinase 5/antagonistas & inibidores , Animais , Biópsia por Agulha , Cardiotônicos , Células Cultivadas , Modelos Animais de Doenças , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Hemodinâmica/fisiologia , Hipertensão Pulmonar/patologia , Imuno-Histoquímica , Camundongos , Artéria Pulmonar/efeitos dos fármacos , Distribuição Aleatória , Ratos , Medição de Risco
4.
Circulation ; 131(12): 1082-97, 2015 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-25628390

RESUMO

BACKGROUND: Thioredoxin 2 (Trx2) is a key mitochondrial protein that regulates cellular redox and survival by suppressing mitochondrial reactive oxygen species generation and by inhibiting apoptosis stress kinase-1 (ASK1)-dependent apoptotic signaling. To date, the role of the mitochondrial Trx2 system in heart failure pathogenesis has not been investigated. METHODS AND RESULTS: Western blot and histological analysis revealed that Trx2 protein expression levels were reduced in hearts from patients with dilated cardiomyopathy, with a concomitant increase in ASK1 phosphorylation/activity. Cardiac-specific Trx2 knockout mice develop spontaneous dilated cardiomyopathy at 1 month of age with increased heart size, reduced ventricular wall thickness, and a progressive decline in left ventricular contractile function, resulting in mortality due to heart failure by ≈4 months of age. The progressive decline in cardiac function observed in cardiac-specific Trx2 knockout mice was accompanied by the disruption of mitochondrial ultrastructure, mitochondrial membrane depolarization, increased mitochondrial reactive oxygen species generation, and reduced ATP production, correlating with increased ASK1 signaling and increased cardiomyocyte apoptosis. Chronic administration of a highly selective ASK1 inhibitor improved cardiac phenotype and reduced maladaptive left ventricular remodeling with significant reductions in oxidative stress, apoptosis, fibrosis, and cardiac failure. Cellular data from Trx2-deficient cardiomyocytes demonstrated that ASK1 inhibition reduced apoptosis and reduced mitochondrial reactive oxygen species generation. CONCLUSIONS: Our data support an essential role for mitochondrial Trx2 in preserving cardiac function by suppressing mitochondrial reactive oxygen species production and ASK1-dependent apoptosis. Inhibition of ASK1 represents a promising therapeutic strategy for the treatment of dilated cardiomyopathy and heart failure.


Assuntos
Cardiomegalia/metabolismo , MAP Quinase Quinase Quinase 5/biossíntese , Mitocôndrias Cardíacas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tiorredoxinas/biossíntese , Animais , Cardiomegalia/fisiopatologia , Células Cultivadas , Humanos , Camundongos , Camundongos Knockout
5.
J Mol Cell Cardiol ; 76: 247-56, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25252177

RESUMO

An increase of late Na(+) current (INaL) in cardiac myocytes can raise the cytosolic Na(+) concentration and is associated with activation of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and alterations of mitochondrial metabolism and Ca(2+) handling by sarcoplasmic reticulum (SR). We tested the hypothesis that augmentation of INaL can increase mitochondrial reactive oxygen species (ROS) production and oxidation of CaMKII, resulting in spontaneous SR Ca(2+) release and increased diastolic Ca(2+) in myocytes. Increases of INaL and/or of the cytosolic Na(+) concentration led to mitochondrial ROS production and oxidation of CaMKII to cause dysregulation of Ca(2+) handling in rabbit cardiac myocytes.


Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Miócitos Cardíacos/enzimologia , Sódio/metabolismo , Potenciais de Ação , Animais , Sinalização do Cálcio , Feminino , Ventrículos do Coração/citologia , Ventrículos do Coração/enzimologia , Espaço Intracelular/metabolismo , Oxirredução , Estresse Oxidativo , Coelhos , Espécies Reativas de Oxigênio/metabolismo
6.
J Neurosci Res ; 91(6): 799-807, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23426889

RESUMO

Activation of protein kinase C∊ (PKC∊) confers protection against neuronal ischemia/reperfusion. Activation of PKC∊ leads to its translocation to multiple intracellular sites, so a mitochondria-selective PKC∊ activator was used to test the importance of mitochondrial activation to the neuroprotective effect of PKC∊. PKC∊ can regulate key cytoprotective mitochondrial functions, including electron transport chain activity, reactive oxygen species (ROS) generation, mitochondrial permeability transition, and detoxification of reactive aldehydes. We tested the ability of mitochondria-selective activation of PKC∊ to protect primary brain cell cultures or mice subjected to ischemic stroke. Pretreatment with either general PKC∊ activator peptide, TAT-Ψ∊RACK, or mitochondrial-selective PKC∊ activator, TAT-Ψ∊HSP90, reduced cell death induced by simulated ischemia/reperfusion in neurons, astrocytes, and mixed neuronal cultures. The protective effects of both TAT-Ψ∊RACK and TAT-Ψ∊HSP90 were blocked by the PKC∊ antagonist ∊V1-2 , indicating that protection requires PKC∊ interaction with its anchoring protein, TAT-∊RACK. Further supporting a mitochondrial mechanism for PKC∊, neuroprotection by TAT-Ψ∊HSP90 was associated with a marked delay in mitochondrial membrane depolarization and significantly attenuated ROS generation during ischemia. Importantly, TAT-Ψ∊HSP90 reduced infarct size and reduced neurological deficit in C57/BL6 mice subjected to middle cerebral artery occlusion and 24 hr of reperfusion. Thus selective activation of mitochondrial PKC∊ preserves mitochondrial function in vitro and improves outcome in vivo, suggesting potential therapeutic value clinically when brain ischemia is anticipated, including neurosurgery and cardiac surgery.


Assuntos
Isquemia Encefálica/enzimologia , Mitocôndrias/enzimologia , Proteína Quinase C-épsilon/metabolismo , Acidente Vascular Cerebral/enzimologia , Animais , Western Blotting , Isquemia Encefálica/patologia , Circulação Cerebrovascular/fisiologia , Ativação Enzimática/fisiologia , Potencial da Membrana Mitocondrial , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/patologia , Acidente Vascular Cerebral/patologia
7.
JHEP Rep ; 5(11): 100874, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37841639

RESUMO

Background & Aims: The nuclear receptor farnesoid X receptor (FXR) is a key regulator of hepatic bile acid (BA) and lipid metabolism, inflammation and fibrosis. Here, we aimed to explore the potential of cilofexor (GS-9674), a non-steroidal FXR agonist, as a therapeutic approach for counteracting features of cholestatic liver injury by evaluating its efficacy and mechanisms in the Mdr2/Abcb4 knockout (-/-) mouse model of sclerosing cholangitis. Methods: FVB/N wild-type and Mdr2-/- or BALB/c wild-type and Mdr2-/- mice were treated with 0, 10, 30 or 90 mg/kg cilofexor by gavage every 24 h for 10 weeks. Serum biochemistry, gene expression profile, hydroxyproline content, and picrosirius red and F4/80 immunostaining, were investigated. Bile flow, biliary bicarbonate and BA output, and hepatic BA profile, were assessed. Results: Cilofexor treatment improved serum levels of aspartate aminotransferase, alkaline phosphatase as well as BAs in Mdr2-/- animals. Hepatic fibrosis was improved, as reflected by the reduced picrosirius red-positive area and hydroxyproline content in liver sections of cilofexor-treated Mdr2-/- mice. Intrahepatic BA concentrations were lowered in cilofexor-treated Mdr2-/- mice, while hepatobiliary bile flow and bicarbonate output were increased. Conclusion: Collectively the current data show that cilofexor treatment improves cholestatic liver injury and decreases hepatic fibrosis in the Mdr2-/- mouse model of sclerosing cholangitis. Impact and implications: Treatment with cilofexor, a non-steroidal farnesoid X receptor (FXR) agonist, improved histological features of sclerosing cholangitis, cholestasis and hepatic fibrosis in the Mdr2-/- mouse model. These findings indicate, that pharmacological stimulation of intestinal FXR-mediated gut-liver signaling, via fibroblast growth factor 15 (thereby reducing bile acid synthesis), may be sufficient to attenuate cholestatic liver injury in the Mdr2-/- mouse model of sclerosing cholangitis, thus arguing for potential therapeutic properties of cilofexor in cholestatic liver diseases.

8.
J Cardiovasc Pharmacol ; 60(3): 276-82, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22635076

RESUMO

PURPOSES: We determined whether a small molecule inhibitor of apoptosis signal-regulating kinase 1 (ASK1-i) could reduce myocardial infarct size in a rat ischemia/reperfusion model. METHODS AND RESULTS: Sprague-Dawley rats were randomized to 3 groups: ASK1-i infusion (n = 16), vehicle infusion (n = 16), or ischemic preconditioning (IPC; n = 15). Infusion of ASK1-i (10 mg/kg, iv) or vehicle commenced 45 minutes before myocardial ischemia. IPC consisted of 3 cycles of 3 minutes of coronary occlusion followed by 5 minutes of reperfusion immediately before index myocardial ischemia, which consisted of 30-minute left coronary occlusion followed by 180 minutes of reperfusion. Pathologic analysis revealed no significant difference in the ischemic risk size among the 3 groups. ASK1-I and IPC significantly reduced myocardial infarct size (27.7% ± 3.3%, 16.5% ± 3.4%, and 41.5% ± 4.8% in the ASK1-i group, the IPC group, and the vehicle group, respectively; P = 0.0002) and apoptosis (the percentage of apoptotic nuclei averaged 11.6% ± 1.0%, 10.2% ± 1.7%, and 17.7% ± 2.0% in the ASK1-i group, IPC group, and vehicle group, respectively, P = 0.0055). CONCLUSIONS: A small molecule inhibitor of ASK1 was shown for the first time to reduce apoptosis and myocardial infarct size in a rat model of ischemia/reperfusion.


Assuntos
Apoptose/efeitos dos fármacos , Modelos Animais de Doenças , MAP Quinase Quinase Quinase 5/antagonistas & inibidores , Infarto do Miocárdio/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Animais , Apoptose/fisiologia , MAP Quinase Quinase Quinase 5/metabolismo , Masculino , Infarto do Miocárdio/enzimologia , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/enzimologia , Traumatismo por Reperfusão Miocárdica/patologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/enzimologia , Miócitos Cardíacos/patologia , Inibidores de Proteínas Quinases/farmacologia , Ratos , Ratos Sprague-Dawley
9.
Circ J ; 76(6): 1476-85, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22453000

RESUMO

BACKGROUND: Epsilon-protein kinase C (εPKC) protects the heart from ischemic injury. However, the mechanism(s) of εPKC cardioprotection is still unclear. Identification of the εPKC targets may aid in elucidating the εPKC-mediated cardioprotective mechanisms. Previous studies, using εPKC transgenic mice and difference in gel electrophoresis, identified proteins involved in glucose metabolism, the expression of which was modified by εPKC. Those studies were accompanied by metabolomic analysis, suggesting that increased glucose oxidation may be responsible for the cardioprotective effect of εPKC. Whether these εPKC-mediated alterations were because of differences in protein expression or phosphorylation was not determined. METHODS AND RESULTS: In the present study, we used an εPKC -specific activator peptide, ψεRACK, combined with phosphoproteomics, to find εPKC targets, and identified that the proteins whose phosphorylation was altered by selective activation of εPKC were mostly mitochondrial proteins. Analysis of the mitochondrial phosphoproteome led to the identification of 55 spots, corresponding to 37 individual proteins, exclusively phosphorylated, in the presence of ψεRACK. The majority of the proteins identified were involved in glucose and lipid metabolism, components of the respiratory chain as well as mitochondrial heat shock proteins. CONCLUSIONS: The protective effect of εPKC during ischemia involves phosphorylation of several mitochondrial proteins involved in glucose and lipid metabolism and oxidative phosphorylation. Regulation of these metabolic pathways by εPKC phosphorylation may lead to εPKC-mediated cardioprotection induced by ψεRACK.


Assuntos
Metabolismo Energético , Mitocôndrias Cardíacas/enzimologia , Isquemia Miocárdica/enzimologia , Miocárdio/enzimologia , Proteína Quinase C-épsilon/metabolismo , Animais , Citoproteção , Modelos Animais de Doenças , Metabolismo Energético/efeitos dos fármacos , Ativação Enzimática , Ativadores de Enzimas/farmacologia , Glucose/metabolismo , Técnicas In Vitro , Metabolismo dos Lipídeos , Isquemia Miocárdica/prevenção & controle , Oligopeptídeos/farmacologia , Fosforilação Oxidativa , Perfusão , Fosforilação , Proteômica/métodos , Ratos , Ratos Wistar , Transdução de Sinais
10.
J Mol Cell Cardiol ; 51(6): 980-7, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21920368

RESUMO

We previously found that in the hearts of hypertensive Dahl salt-sensitive rats, ßIIPKC levels increase during the transition from compensated cardiac hypertrophy to cardiac dysfunction. Here we showed that a six-week treatment of these hypertensive rats with a ßIIPKC-specific inhibitor, ßIIV5-3, prolonged their survival by at least 6weeks, suppressed myocardial fibrosis and inflammation, and delayed the transition from compensated hypertrophy to cardiac dysfunction. In addition, changes in the levels of the Ca(2+)-handling proteins, SERCA2 and the Na(+)/Ca(2+) exchanger, as well as troponin I phosphorylation, seen in the control-treated hypertensive rats were not observed in the ßΙΙPKC-treated rats, suggesting that ßΙΙPKC contributes to the regulation of calcium levels in the myocardium. In contrast, treatment with the selective inhibitor of ßIPKC, an alternative spliced form of ßIIPKC, had no beneficial effects in these rats. We also found that ßIIV5-3, but not ßIV5-3, improved calcium handling in isolated rat cardiomyocytes and enhanced contractility in isolated rat hearts. In conclusion, our data using an in vivo model of cardiac dysfunction (late-phase hypertrophy), suggest that ßIIPKC contributes to the pathology associated with heart failure and thus an inhibitor of ßIIPKC may be a potential treatment for this disease.


Assuntos
Cardiomegalia/enzimologia , Cardiomegalia/prevenção & controle , Peptídeos/farmacologia , Proteína Quinase C/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Sequência de Aminoácidos , Animais , Cálcio/metabolismo , Cardiomegalia/mortalidade , Cardiomiopatias/metabolismo , Cardiomiopatias/patologia , Modelos Animais de Doenças , Fibrose , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/prevenção & controle , Masculino , Contração Miocárdica/efeitos dos fármacos , Miocárdio/metabolismo , Miocárdio/patologia , Miócitos Cardíacos/metabolismo , Proteína Quinase C beta , Ratos , Ratos Endogâmicos Dahl , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Trocador de Sódio e Cálcio/metabolismo
11.
Am J Physiol Cell Physiol ; 301(3): C577-86, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21677263

RESUMO

Late Na(+) current (I(NaL)) and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) are both increased in the diseased heart. Recently, CaMKII was found to phosphorylate the Na(+) channel 1.5 (Na(v)1.5), resulting in enhanced I(NaL). Conversely, an increase of I(NaL) would be expected to cause elevation of intracellular Ca(2+) and activation of CaMKII. However, a relationship between enhancement of I(NaL) and activation of CaMKII has yet to be demonstrated. We investigated whether Na(+) influx via Na(v)1.5 leads to CaMKII activation and explored the functional significance of this pathway. In neonatal rat ventricular myocytes (NRVM), treatment with the I(NaL) activators anemone toxin II (ATX-II) or veratridine increased CaMKII autophosphorylation and increased phosphorylation of CaMKII substrates phospholamban and ryanodine receptor 2. Knockdown of Na(v)1.5 (but not Na(v)1.1 or Na(v)1.2) prevented ATX-II-induced CaMKII phosphorylation, providing evidence for a specific role of Na(v)1.5 in CaMKII activation. In support of this view, CaMKII activity was also increased in hearts of transgenic mice overexpressing a gain-of-function Na(v)1.5 mutant (N(1325)S). The effects of both ATX-II and the N(1325)S mutation were reversed by either I(NaL) inhibition (with ranolazine or tetrodotoxin) or CaMKII inhibition (with KN93 or autocamtide 2-related inhibitory peptide). Furthermore, ATX-II treatment also induced CaMKII-Na(v)1.5 coimmunoprecipitation. The same association between CaMKII and Na(v)1.5 was also found in N(1325)S mice, suggesting a direct protein-protein interaction. Pharmacological inhibitions of either CaMKII or I(NaL) also prevented ATX-II-induced cell death in NRVM and reduced the incidence of polymorphic ventricular tachycardia induced by ATX-II in rat perfused hearts. Taken together, these results suggest that a Na(v)1.5-dependent increase in Na(+) influx leads to activation of CaMKII, which in turn phosphorylates Na(v)1.5, further promoting Na(+) influx. Pharmacological inhibition of either CaMKII or Na(v)1.5 can ameliorate cardiac dysfunction caused by excessive Na(+) influx.


Assuntos
Substituição de Aminoácidos/fisiologia , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Ventrículos do Coração/metabolismo , Miócitos Cardíacos/metabolismo , Canais de Sódio/metabolismo , Sódio/metabolismo , Acetanilidas/farmacologia , Acetanilidas/uso terapêutico , Animais , Animais Recém-Nascidos , Cálcio/metabolismo , Sinalização do Cálcio/efeitos dos fármacos , Sinalização do Cálcio/fisiologia , Proteínas de Ligação ao Cálcio/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/antagonistas & inibidores , Caspase 3/metabolismo , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Venenos de Cnidários/farmacologia , Relação Dose-Resposta a Droga , Fenômenos Eletrofisiológicos/efeitos dos fármacos , Fenômenos Eletrofisiológicos/fisiologia , Feminino , Expressão Gênica/efeitos dos fármacos , Ventrículos do Coração/citologia , Ventrículos do Coração/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos , Camundongos Transgênicos , Miócitos Cardíacos/efeitos dos fármacos , Canal de Sódio Disparado por Voltagem NAV1.5 , Peptídeos/farmacologia , Peptídeos/uso terapêutico , Perfusão , Fosforilação/efeitos dos fármacos , Piperazinas/farmacologia , Piperazinas/uso terapêutico , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/fisiologia , RNA Interferente Pequeno/genética , Coelhos , Ranolazina , Ratos , Ratos Sprague-Dawley , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Canais de Sódio/genética , Trocador de Sódio e Cálcio/antagonistas & inibidores , Trocador de Sódio e Cálcio/metabolismo , Taquicardia Ventricular/induzido quimicamente , Taquicardia Ventricular/prevenção & controle , Tetrodotoxina/farmacologia , Veratridina/farmacologia
12.
Biomolecules ; 11(12)2021 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-34944441

RESUMO

Protein kinase Cε (PKCε) is highly expressed in nociceptor neurons and its activation has been reported as pro-nociceptive. Intriguingly, we previously demonstrated that activation of the mitochondrial PKCε substrate aldehyde dehydrogenase-2 (ALDH2) results in anti-nociceptive effects. ALDH2 is a major enzyme responsible for the clearance of 4-hydroxy-2-nonenal (4-HNE), an oxidative stress byproduct accumulated in inflammatory conditions and sufficient to induce pain hypersensitivity in rodents. Here we determined the contribution of the PKCε-ALDH2 axis during 4-HNE-induced mechanical hypersensitivity. Using knockout mice, we demonstrated that PKCε is essential for the nociception recovery during 4-HNE-induced hypersensitivity. We also found that ALDH2 deficient knockin mice display increased 4-HNE-induced nociceptive behavior. As proof of concept, the use of a selective peptide activator of PKCε (ΨεHSP90), which favors PKCε translocation to mitochondria and activation of PKCε-ALDH2 axis, was sufficient to block 4-HNE-induced hypersensitivity in WT, but not in ALDH2-deficient mice. Similarly, ΨεHSP90 administration prevented mechanical hypersensitivity induced by endogenous production of 4-HNE after carrageenan injection. These findings provide evidence that selective activation of mitochondrial PKCε-ALDH2 axis is important to mitigate aldehyde-mediated pain in rodents, suggesting that ΨεHSP90 and small molecules that mimic it may be a potential treatment for patients with pain.


Assuntos
Aldeído-Desidrogenase Mitocondrial/genética , Aldeídos/efeitos adversos , Dor/metabolismo , Proteína Quinase C-épsilon/metabolismo , Aldeído-Desidrogenase Mitocondrial/metabolismo , Animais , Carragenina/efeitos adversos , Modelos Animais de Doenças , Técnicas de Introdução de Genes , Técnicas de Inativação de Genes , Masculino , Camundongos , Mitocôndrias/metabolismo , Dor/induzido quimicamente , Transporte Proteico
13.
Biomedicines ; 9(1)2021 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-33435509

RESUMO

BACKGROUND: The farnesoid X receptor (FXR) influences hepatic metabolism, inflammation and liver fibrosis as key components of non-alcoholic steatohepatitis (NASH). We studied the effects of the non-steroidal FXR agonist cilofexor (formerly GS-9674) on portal pressure and fibrosis in experimental NASH. METHODS: NASH was induced in Wistar rats using a choline-deficient high-fat diet plus intraperitoneal sodium nitrite injections. First, a dose-finding study was performed with 10 mg/kg and 30 mg/kg of cilofexor, focusing on histological readouts. Liver fibrosis was assessed by Picro-Sirius-Red, desmin staining and hepatic hydroxyproline content. Gene expression was determined by RT-PCR. In a subsequent hemodynamic study, rats received 30 mg/kg cilofexor with or without propranolol (25 mg/kg). Portal pressure, systemic hemodynamics and splanchnic blood flow were measured. RESULTS: Cilofexor dose-dependently induced FXR target genes shp, cyp7a1 and fgf15 in hepatic and ileal tissues, paralleled by a dose-dependent reduction in liver fibrosis area (Picro-Sirius-Red) of -41% (10 mg/kg) and -69% (30 mg/kg), respectively. The 30 mg/kg cilofexor dose significantly reduced hepatic hydroxyproline content (-41%), expression of col1a1 (-37%) and pdgfr-ß (-36%), as well as desmin area (-42%) in NASH rats. Importantly, cilofexor decreased portal pressure (11.9 ± 2.1 vs. 8.9 ± 2.2 mmHg; p = 0.020) without affecting splanchnic blood-flow or systemic hemodynamics. The addition of propranolol to cilofexor additionally reduced splanchnic inflow (-28%) but also mean arterial pressure (-25%) and heart rate (-37%). CONCLUSION: The non-steroidal FXR agonist cilofexor decreased portal hypertension and reduced liver fibrosis in NASH rats. While cilofexor seems to primarily decrease sinusoidal resistance in cirrhotic portal hypertension, the combination with propranolol additionally reduced mesenteric hyperperfusion.

14.
Sci Transl Med ; 13(616): eabe8939, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34669440

RESUMO

Noninvasive detection of nonalcoholic steatohepatitis (NASH), the progressive form of nonalcoholic fatty liver disease, promises to improve patient screening, accelerate drug trials, and reduce health care costs. On the basis of protease dysregulation of the biological pathways of fibrotic NASH, we developed the Glympse Bio Test System (GBTS) for multiplexed quantification of liver protease activity. GBTS-NASH comprises a mixture of 19 mass-barcoded PEGylated peptides that is administered intravenously and senses liver protease activity by releasing mass-barcoded reporters into urine for analysis by mass spectrometry. To identify a protease signature of NASH, transcriptomic analysis of 355 human liver biopsies identified a 13-protease panel that discriminated clinically relevant NASH ≥F2 fibrosis from F0-F1 with high classification accuracy across two independent patient datasets. We screened 159 candidate substrates to identify a panel of 19 peptides that exhibited high activity for our 13-protease panel. In the choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) mouse model, binary classifiers trained on urine samples discriminated fibrotic NASH from simple steatosis and healthy controls across a range of nondisease conditions and indicated disease regression upon diet change [area under receiver operating characteristics (AUROCs) > 0.97]. Using a hepatoprotective triple combination treatment (FXR agonist, ACC and ASK1 inhibitors) in a rat model of NASH, urinary classification distinguished F0-F1 from ≥F2 animals and indicated therapeutic response as early as 1 week on treatment (AUROCs >0.91). Our results support GBTS-NASH to diagnose fibrotic NASH via an infusion of peptides, monitor changes in disease severity, and indicate early treatment response.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Fibrose , Humanos , Peptídeos
15.
J Mol Cell Cardiol ; 48(4): 757-64, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19913552

RESUMO

Acute administration of ethanol can reduce cardiac ischemia/reperfusion injury. Previous studies demonstrated that the acute cytoprotective effect of ethanol on the myocardium is mediated by protein kinase C epsilon (PKCvarepsilon). We recently identified aldehyde dehydrogenase 2 (ALDH2) as a PKCvarepsilon substrate, whose activation is necessary and sufficient to confer cardioprotection in vivo. ALDH2 metabolizes cytotoxic reactive aldehydes, such as 4-hydroxy-2-nonenal (4-HNE), which accumulate during cardiac ischemia/reperfusion. Here, we used a combination of PKCvarepsilon knockout mice and a direct activator of ALDH2, Alda-44, to further investigate the interplay between PKCvarepsilon and ALDH2 in cardioprotection. We report that ethanol preconditioning requires PKCvarepsilon, whereas direct activation of ALDH2 reduces infarct size in both wild type and PKCvarepsilon knockout hearts. Our data suggest that ALDH2 is downstream of PKCvarepsilon in ethanol preconditioning and that direct activation of ALDH2 can circumvent the requirement of PKCvarepsilon to induce cytoprotection. We also report that in addition to ALDH2 activation, Alda-44 prevents 4-HNE induced inactivation of ALDH2 by reducing the formation of 4-HNE-ALDH2 protein adducts. Thus, Alda-44 promotes metabolism of cytotoxic reactive aldehydes that accumulate in ischemic myocardium. Taken together, our findings suggest that direct activation of ALDH2 may represent a method of harnessing the cardioprotective effect of ethanol without the side effects associated with alcohol consumption.


Assuntos
Aldeído Desidrogenase/metabolismo , Regulação Enzimológica da Expressão Gênica , Proteína Quinase C-épsilon/metabolismo , Aldeído-Desidrogenase Mitocondrial , Animais , Ativação Enzimática , Etanol/química , Coração/fisiologia , Humanos , Camundongos , Camundongos Knockout , Mutação , Isquemia Miocárdica/patologia , Proteína Quinase C/metabolismo , Proteína Quinase C-épsilon/genética , Traumatismo por Reperfusão , Transdução de Sinais
16.
Pulm Circ ; 10(2): 2045894020922810, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32523684

RESUMO

Pulmonary arterial hypertension, group 1 of the pulmonary hypertension disease family, involves pulmonary vascular remodelling, right ventricular dysfunction and cardiac failure. Oxidative stress, through activation of mitogen-activated protein kinases is implicated in these changes. Inhibition of apoptosis signal-regulating kinase 1, an apical mitogen-activated protein kinase, prevented pulmonary arterial hypertension developing in rodent models. Here, we investigate apoptosis signal-regulating kinase 1 in pulmonary arterial hypertension by examining the impact that its inhibition has on the molecular and cellular signalling in established disease. Apoptosis signal-regulating kinase 1 inhibition was investigated in in vivo pulmonary arterial hypertension and in vitro pulmonary hypertension models. In the in vivo model, male Sprague Dawley rats received a single subcutaneous injection of Sugen SU5416 (20 mg/kg) prior to two weeks of hypobaric hypoxia (380 mmHg) followed by three weeks normoxia (Sugen/hypoxic), then animals were either maintained for three weeks on control chow or one containing apoptosis signal-regulating kinase 1 inhibitor (100 mg/kg/day). Cardiovascular measurements were carried out. In the in vitro model, primary cultures of rat pulmonary artery fibroblasts and rat pulmonary artery smooth muscle cells were maintained in hypoxia (5% O2) and investigated for proliferation, migration and molecular signalling in the presence or absence of apoptosis signal-regulating kinase 1 inhibitor. Sugen/hypoxic animals displayed significant pulmonary arterial hypertension compared to normoxic controls at eight weeks. Apoptosis signal-regulating kinase 1 inhibitor decreased right ventricular systolic pressure to control levels and reduced muscularised vessels in lung tissue. Apoptosis signal-regulating kinase 1 inhibition was found to prevent hypoxia-induced proliferation, migration and cytokine release in rat pulmonary artery fibroblasts and also prevented rat pulmonary artery fibroblast-induced rat pulmonary artery smooth muscle cell migration and proliferation. Apoptosis signal-regulating kinase 1 inhibition reversed pulmonary arterial hypertension in the Sugen/hypoxic rat model. These effects may be a result of intrinsic changes in the signalling of adventitial fibroblast.

17.
JCI Insight ; 5(2)2020 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-31996485

RESUMO

Hepatic inflammasome activation is considered a major contributor to liver fibrosis in NASH. Apoptosis signal-regulating kinase 1 (ASK1) is an apical mitogen-activated protein kinase that activates hepatic JNK and p38 to promote apoptosis, inflammation, and fibrosis. The aim of the current study was to investigate whether pharmacologic inhibition of ASK1 could attenuate hepatic fibrosis driven by inflammasome activation using gain-of-function NOD-like receptor protein 3 (Nlrp3) mutant mice. Tamoxifen-inducible Nlrp3 knock-in (Nlrp3A350V/+CreT-KI) mice and WT mice were administered either control chow diet or diet containing the selective ASK1 inhibitor GS-444217 for 6 weeks. Livers of Nlrp3-KI mice had increased inflammation, cell death, and fibrosis and increased phosphorylation of ASK1, p38, and c-Jun. GS-444217 reduced ASK1 pathway activation, liver cell death, and liver fibrosis. ASK1 inhibition resulted in a significant downregulation of genes involved in collagen production and extracellular matrix deposition, as well as in a reduced hepatic TNF-α expression. ASK1 inhibition also directly reduced LPS-induced gene expression of Collagen 1A1 (Col1a1) in hepatic stellate cells isolated from Nlrp3-KI mice. In conclusion, ASK1 inhibition reduced liver cell death and fibrosis downstream of inflammatory signaling induced by NLRP3. These data provide mechanistic insight into the antifibrotic mechanisms of ASK1 inhibition.


Assuntos
Morte Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Cirrose Hepática/metabolismo , Fígado/lesões , Fígado/metabolismo , MAP Quinase Quinase Quinase 5/efeitos dos fármacos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Administração Oral , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Cadeia alfa 1 do Colágeno Tipo I , Inibidores Enzimáticos/administração & dosagem , Feminino , Regulação da Expressão Gênica , Células Estreladas do Fígado/metabolismo , Inflamassomos/metabolismo , Inflamação/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Cirrose Hepática/patologia , MAP Quinase Quinase Quinase 5/genética , MAP Quinase Quinase Quinase 5/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos NOD , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Fosforilação , Transdução de Sinais , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
18.
Cell Rep ; 29(7): 1832-1847.e8, 2019 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-31722201

RESUMO

Iterative liver injury results in progressive fibrosis disrupting hepatic architecture, regeneration potential, and liver function. Hepatic stellate cells (HSCs) are a major source of pathological matrix during fibrosis and are thought to be a functionally homogeneous population. Here, we use single-cell RNA sequencing to deconvolve the hepatic mesenchyme in healthy and fibrotic mouse liver, revealing spatial zonation of HSCs across the hepatic lobule. Furthermore, we show that HSCs partition into topographically diametric lobule regions, designated portal vein-associated HSCs (PaHSCs) and central vein-associated HSCs (CaHSCs). Importantly we uncover functional zonation, identifying CaHSCs as the dominant pathogenic collagen-producing cells in a mouse model of centrilobular fibrosis. Finally, we identify LPAR1 as a therapeutic target on collagen-producing CaHSCs, demonstrating that blockade of LPAR1 inhibits liver fibrosis in a rodent NASH model. Taken together, our work illustrates the power of single-cell transcriptomics to resolve the key collagen-producing cells driving liver fibrosis with high precision.


Assuntos
Células Estreladas do Fígado/metabolismo , Cirrose Hepática/metabolismo , Análise de Célula Única , Transcriptoma , Animais , Modelos Animais de Doenças , Células Estreladas do Fígado/patologia , Humanos , Cirrose Hepática/genética , Cirrose Hepática/patologia , Camundongos , Camundongos Transgênicos , Ratos , Ratos Wistar , Receptores de Ácidos Lisofosfatídicos/genética , Receptores de Ácidos Lisofosfatídicos/metabolismo
19.
Biochem Pharmacol ; 151: 282-290, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29408488

RESUMO

Despite improved therapy, rheumatoid arthritis (RA) remains an unmet medical need. Previous efforts to validate therapeutic targets in the mitogen-activated protein kinase (MAPK) family have had minimal success. Therefore, we evaluated the potential for targeting an upstream MAPK, namely apoptosis signal-regulating kinase 1 (ASK1), as an alternative approach. ASK1 protein and gene expression were observed in RA and osteoarthritis (OA) synovium as determined by immunohistochemistry (IHC) and qPCR, respectively, particularly in the synovial intimal lining. For RA, but not OA synovium, ASK1 correlated with IL-1ß and TNF gene expression. ASK1 was also expressed by cultured fibroblast-like synoviocytes (FLS), with significantly higher levels in RA compared with OA cells. IL-1ß and TNF stimulation significantly increased ASK1 expression in a time-and concentration-dependent manner in cultured FLS. ASK1 promoter activity was significantly increased by IL-1ß and TNF and was dependent on an upstream RelA binding motif. A selective small molecule ASK1 inhibitor reduced RA FLS invasion, migration and proliferation in vitro and decreased arthritis severity in the rat collagen-induced arthritis (CIA) model. In summary, our findings demonstrate that ASK1 modulates signaling pathways relevant to RA in vitro and in vivo. It is induced by inflammatory cytokines through the activation of NF-κB, which could provide some site- and event specificity. Thus, inhibitors of the upstream MAPK ASK1 could be a novel approach to treating inflammatory arthritis.


Assuntos
Artrite Reumatoide/enzimologia , MAP Quinase Quinase Quinase 5/metabolismo , Osteoartrite/enzimologia , Animais , Artrite Experimental/tratamento farmacológico , Artrite Experimental/metabolismo , Artrite Experimental/patologia , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/patologia , Células Cultivadas , Citocinas/imunologia , Inibidores Enzimáticos/uso terapêutico , Feminino , Regulação da Expressão Gênica , Humanos , MAP Quinase Quinase Quinase 5/antagonistas & inibidores , MAP Quinase Quinase Quinase 5/genética , Terapia de Alvo Molecular , Osteoartrite/tratamento farmacológico , Osteoartrite/patologia , Ratos Endogâmicos Lew , Transdução de Sinais , Membrana Sinovial/efeitos dos fármacos , Membrana Sinovial/metabolismo , Membrana Sinovial/patologia , Sinoviócitos/efeitos dos fármacos , Sinoviócitos/metabolismo , Sinoviócitos/patologia
20.
J Clin Invest ; 128(10): 4485-4500, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30024858

RESUMO

Oxidative stress is an underlying component of acute and chronic kidney disease. Apoptosis signal-regulating kinase 1 (ASK1) is a widely expressed redox-sensitive serine threonine kinase that activates p38 and c-Jun N-terminal kinase (JNK) mitogen-activated protein kinase kinases, and induces apoptotic, inflammatory, and fibrotic signaling in settings of oxidative stress. We describe the discovery and characterization of a potent and selective small-molecule inhibitor of ASK1, GS-444217, and demonstrate the therapeutic potential of ASK1 inhibition to reduce kidney injury and fibrosis. Activation of the ASK1 pathway in glomerular and tubular compartments was confirmed in renal biopsies from patients with diabetic kidney disease (DKD) and was decreased by GS-444217 in several rodent models of kidney injury and fibrosis that collectively represented the hallmarks of DKD pathology. Treatment with GS-444217 reduced progressive inflammation and fibrosis in the kidney and halted glomerular filtration rate decline. Combination of GS-444217 with enalapril, an angiotensin-converting enzyme inhibitor, led to a greater reduction in proteinuria and regression of glomerulosclerosis. These results identify ASK1 as an important target for renal disease and support the clinical development of an ASK1 inhibitor for the treatment of DKD.


Assuntos
Nefropatias Diabéticas/enzimologia , Fibroblastos/enzimologia , Glomérulos Renais/enzimologia , MAP Quinase Quinase Quinase 5/metabolismo , Sistema de Sinalização das MAP Quinases , Animais , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/genética , Nefropatias Diabéticas/patologia , Modelos Animais de Doenças , Feminino , Fibroblastos/patologia , Fibrose , Humanos , Glomérulos Renais/patologia , MAP Quinase Quinase Quinase 5/antagonistas & inibidores , MAP Quinase Quinase Quinase 5/genética , Masculino , Camundongos , Camundongos Knockout , Inibidores de Proteínas Quinases/farmacologia , Distribuição Aleatória , Ratos Sprague-Dawley
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