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1.
Circulation ; 142(12): 1190-1204, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32755395

RESUMO

BACKGROUND: Angiotensin-converting enzyme 2 (ACE2) converts angiotensin II, a potent vasoconstrictor, to angiotensin-(1-7) and is also a membrane protein that enables coronavirus disease 2019 (COVID-19) infectivity. AMP-activated protein kinase (AMPK) phosphorylation of ACE2 enhances ACE2 stability. This mode of posttranslational modification of ACE2 in vascular endothelial cells is causative of a pulmonary hypertension (PH)-protective phenotype. The oncoprotein MDM2 (murine double minute 2) is an E3 ligase that ubiquitinates its substrates to cause their degradation. In this study, we investigated whether MDM2 is involved in the posttranslational modification of ACE2 through its ubiquitination of ACE2, and whether an AMPK and MDM2 crosstalk regulates the pathogenesis of PH. METHODS: Bioinformatic analyses were used to explore E3 ligase that ubiquitinates ACE2. Cultured endothelial cells, mouse models, and specimens from patients with idiopathic pulmonary arterial hypertension were used to investigate the crosstalk between AMPK and MDM2 in regulating ACE2 phosphorylation and ubiquitination in the context of PH. RESULTS: Levels of MDM2 were increased and those of ACE2 decreased in lung tissues or pulmonary arterial endothelial cells from patients with idiopathic pulmonary arterial hypertension and rodent models of experimental PH. MDM2 inhibition by JNJ-165 reversed the SU5416/hypoxia-induced PH in C57BL/6 mice. ACE2-S680L mice (dephosphorylation at S680) showed PH susceptibility, and ectopic expression of ACE2-S680L/K788R (deubiquitination at K788) reduced experimental PH. Moreover, ACE2-K788R overexpression in mice with endothelial cell-specific AMPKα2 knockout mitigated PH. CONCLUSIONS: Maladapted posttranslational modification (phosphorylation and ubiquitination) of ACE2 at Ser-680 and Lys-788 is involved in the pathogenesis of pulmonary arterial hypertension and experimental PH. Thus, a combined intervention of AMPK and MDM2 in the pulmonary endothelium might be therapeutically effective in PH treatment.


Assuntos
Peptidil Dipeptidase A/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Hipertensão Arterial Pulmonar/patologia , Ubiquitinação , Proteínas Quinases Ativadas por AMP/deficiência , Proteínas Quinases Ativadas por AMP/genética , Animais , Suscetibilidade a Doenças , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Peptidil Dipeptidase A/genética , Polimorfismo de Nucleotídeo Único , Proteínas Proto-Oncogênicas c-mdm2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-mdm2/genética , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Ratos
2.
Am J Med Sci ; 360(3): 279-286, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32829780

RESUMO

BACKGROUND: The essential role of 6-phosphogluconate dehydrogenase (6PGD), the enzyme catalyzing the oxidative pentose phosphate pathway, in tumor growth and metabolism has garnered attention in recent years. In this work, we are the first to demonstrate that aberrant activation of 6PGD is a feature in renal cell carcinoma (RCC) and is critically involved in renal carcinogenesis and chemo- and immuno-resistance. MATERIALS AND METHODS: 6PGD expression and activity were systematically analyzed in normal and malignant renal cells and tissues. The roles of 6PGD and its downstream mechanism were investigated using gain-of-function and loss-of-function approaches. RESULTS: 6PGD expression and enzyme activity were increased in RCC cells and patients' samples. Activation of 6PGD via gain-of-function approach promoted growth of normal kidney but not RCC cells, and alleviated the efficacy of chemotherapeutic (e.g., 5-FU) and immunotherapeutic (e.g., IFN-α) agents. In contrast, 6PGD inhibition using siRNA knockdown and pharmacological inhibitor physcion augmented the inhibitory effects of 5-FU and IFN-α in RCC. Mechanistic studies demonstrated that 6PGD inhibition activated AMPK signaling, leading to ACC1 enzyme inhibition and reduction of lipid synthesis. In addition, 6PGD inhibition disrupted NADPH and NADH homeostasis in RCC cells as shown by the decreased level of NADPH and NADH, and suppressed SIRT-1 activity. AMPK inhibition by siRNA knockdown reversed the inhibitory effects of physcion, demonstrating that the effect of 6PGD inhibition is AMPK activation dependent. CONCLUSIONS: Our work provides preclinical evidence that 6PGD inhibition may represent a potential therapeutic strategy to augment the efficacy of RCC standard of care drugs.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Carcinoma de Células Renais/terapia , Reprogramação Celular/fisiologia , Neoplasias Renais/terapia , Fosfogluconato Desidrogenase/metabolismo , Transdução de Sinais/fisiologia , Proteínas Quinases Ativadas por AMP/genética , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/patologia , Linhagem Celular , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/fisiologia , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Fluoruracila/uso terapêutico , Técnicas de Silenciamento de Genes , Humanos , Imunoterapia , Interferon-alfa/uso terapêutico , Rim/patologia , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/patologia , NADP/fisiologia , Fosfogluconato Desidrogenase/antagonistas & inibidores , Fosfogluconato Desidrogenase/genética , RNA Interferente Pequeno , Regulação para Cima
3.
Pol J Microbiol ; 69(2): 223-229, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32548987

RESUMO

Bovine tuberculosis is an airborne infectious disease caused by organisms of the Mycobacterium tuberculosis (MTB) complex. Mycolic acid (MA) is the main lipid component of the cell membrane of MTB. It is non-enzymatically reduced by NAD(P)H and further produces reactive oxygen species (ROS), which can cause oxidative stress in human cells. N-acetylcysteine (NAC) is a synthetic precursor of glutathione (GSH) and exhibits anti-ROS activity. However, the underlying mechanisms of its protective properties remain uncertain. Herein, after pre-incubation of RAW264.7 cells with NAC, the factors associated with apoptosis and autophagy were measured. Mechanistically, NAC could reduce MA-induced expression of pro-apoptotic and pro-autophagy proteins. At the mRNA level, NAC can inhibit AMPK and activate mTOR expression. The results indicate that NAC might regulate autophagy in RAW264.7 cells through the AMPK/mTOR pathway. To further prove the effect of NAC on MA, ICR mice were used to evaluate the lung injury. Hematoxylin-eosin (HE) staining was performed on the lung. The results show that NAC could reduce cell injury induced by MA. In conclusion, our research showed that NAC attenuates apoptosis and autophagy in response to incubation with mycolic acid.Bovine tuberculosis is an airborne infectious disease caused by organisms of the Mycobacterium tuberculosis (MTB) complex. Mycolic acid (MA) is the main lipid component of the cell membrane of MTB. It is non-enzymatically reduced by NAD(P)H and further produces reactive oxygen species (ROS), which can cause oxidative stress in human cells. N-acetylcysteine (NAC) is a synthetic precursor of glutathione (GSH) and exhibits anti-ROS activity. However, the underlying mechanisms of its protective properties remain uncertain. Herein, after pre-incubation of RAW264.7 cells with NAC, the factors associated with apoptosis and autophagy were measured. Mechanistically, NAC could reduce MA-induced expression of pro-apoptotic and pro-autophagy proteins. At the mRNA level, NAC can inhibit AMPK and activate mTOR expression. The results indicate that NAC might regulate autophagy in RAW264.7 cells through the AMPK/mTOR pathway. To further prove the effect of NAC on MA, ICR mice were used to evaluate the lung injury. Hematoxylin-eosin (HE) staining was performed on the lung. The results show that NAC could reduce cell injury induced by MA. In conclusion, our research showed that NAC attenuates apoptosis and autophagy in response to incubation with mycolic acid.


Assuntos
Acetilcisteína/farmacologia , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Mycobacterium tuberculosis/química , Proteínas Quinases Ativadas por AMP/genética , Animais , Apoptose/genética , Autofagia/genética , Pulmão/efeitos dos fármacos , Pulmão/microbiologia , Lesão Pulmonar/microbiologia , Camundongos , Ácidos Micólicos/farmacologia , Células RAW 264.7 , Serina-Treonina Quinases TOR/genética
4.
Gene ; 753: 144807, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32461017

RESUMO

Mitochondrial transcription factor A (TFAM), which is required for mitochondrial DNA (mtDNA) transcription, has been linked to metabolic changes that contribute to tumorigenesis and chemoresistance. In this work, we investigated the expression pattern and role of TFAM in hepatocellular carcinoma (HCC). TFAM expression level is similar in 18 out of 20 paired normal liver and HCC tissues with only 2 HCC tissues showing 1.8-fold increase in TFAM. Similar phenomenon was observed in HCC cell lines compared to normal liver lines. Interestingly, TFAM expression is upregulated in resistant HCC cells regardless of the differential TFAM expression level in their parental lines and mechanism of resistance. TFAM depletion led to inhibition of growth and survival but not migration, and sensitization to doxorubicin and sorafenib treatment, through AMPK activation, reduction of nucleoside triphosphates and mitochondrial respiration in HCC cells. In addition, we demonstrated that resistant HCC cell lines were more sensitive to TFAM inhibition than parental lines, and this might be due to the increased mitochondrial biogenesis in resistant HCC cell lines. Our work reveals the preferential role of TFAM in HCC cell response to standard of care drugs, which suggests a potential sensitizing therapeutic target for HCC treatment.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Carcinoma Hepatocelular/tratamento farmacológico , Proteínas de Ligação a DNA/deficiência , Doxorrubicina/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Mitocôndrias/metabolismo , Proteínas Mitocondriais/deficiência , Sorafenibe/farmacologia , Fatores de Transcrição/deficiência , Proteínas Quinases Ativadas por AMP/genética , Adulto , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Transformação Celular Neoplásica , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Mitocôndrias/genética , Proteínas Mitocondriais/antagonistas & inibidores , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação para Cima
5.
J Food Sci ; 85(6): 1897-1906, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32449949

RESUMO

The anshenyizhi compound (AC), a mixture from Chinese medicine herbs, has numerous biological effects. In the present study, the acute exercise-treated mice model was established to explore the antifatigue properties of AC and its underlying mechanisms. AC increased exercise endurance in the weight-loaded forced swimming test and rota-rod test. The antifatigue properties of AC were closely correlated with enhancing the body's exercise endurance by increasing the levels of cyanmethemoglobin, testosterone/corticosterone, and creatine kinase, while decreasing the levels of lactic acid, lactate dehydrogenase, and blood urea nitrogen in serum. Moreover, our results confirmed the antioxidant ability of AC by improving the activities of superoxide dismutase while reducing reactive oxygen species and malondialdehyde levels in serum. The AC also improved the storage of glycogen by increasing the levels of succinate dehydrogenase, and malate dehydrogenase in liver and muscle. Additionally, AC displayed the antifatigue and antiapoptosis effects via regulating Nrf2-mediated oxidative stress, AMPK-related glucose metabolism, and p53 pathways. Our experimental results first provided a support that AC had effects on antifatigue through regulating AMPK/PGC-1α-related energy metabolism and Nrf2/ARE-mediated oxidative stress. Consequently, AC could be developed into a new functional food supplement for the prevention and treatment of diseases related to fatigue in the future.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Medicamentos de Ervas Chinesas/administração & dosagem , Fadiga/tratamento farmacológico , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Transativadores/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Animais , Elementos de Resposta Antioxidante/efeitos dos fármacos , Antioxidantes/metabolismo , Metabolismo Energético , Fadiga/genética , Fadiga/metabolismo , Glicogênio/metabolismo , Humanos , Fígado/metabolismo , Masculino , Malondialdeído/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Fator 2 Relacionado a NF-E2/genética , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Natação , Transativadores/genética
6.
Int J Mol Sci ; 21(10)2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32429235

RESUMO

We live and to do so we must breathe and eat, so are we a combination of what we eat and breathe? Here, we will consider this question, and the role in this respect of the AMP-activated protein kinase (AMPK). Emerging evidence suggests that AMPK facilitates central and peripheral reflexes that coordinate breathing and oxygen supply, and contributes to the central regulation of feeding and food choice. We propose, therefore, that oxygen supply to the body is aligned with not only the quantity we eat, but also nutrient-based diet selection, and that the cell-specific expression pattern of AMPK subunit isoforms is critical to appropriate system alignment in this respect. Currently available information on how oxygen supply may be aligned with feeding and food choice, or vice versa, through our motivation to breathe and select particular nutrients is sparse, fragmented and lacks any integrated understanding. By addressing this, we aim to provide the foundations for a clinical perspective that reveals untapped potential, by highlighting how aberrant cell-specific changes in the expression of AMPK subunit isoforms could give rise, in part, to known associations between metabolic disease, such as obesity and type 2 diabetes, sleep-disordered breathing, pulmonary hypertension and acute respiratory distress syndrome.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Oxigênio/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Animais , Dieta , Humanos , Doenças Metabólicas/metabolismo , Doenças Metabólicas/patologia , Isoformas de Proteínas/metabolismo , Respiração , Transtornos Respiratórios/metabolismo , Transtornos Respiratórios/patologia , Termogênese
7.
Phytomedicine ; 72: 153232, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32460034

RESUMO

BACKGROUND: In chronic kidney disease, although fibrosis prevention is beneficial, few interventions are available that specifically target fibrogenesis. Poricoic acid A (PAA) isolated from Poria cocos exhibits anti-fibrotic effects in the kidney, however the underlying mechanisms remain obscure. PURPOSE: We isolated PAA and investigated its effects and the underlying mechanisms in renal fibrosis. STUDY DESIGN: Unilateral ureteral obstruction (UUO) and 5/6 nephrectomy (Nx) animal models and TGF-ß1-induced renal fibroblasts (NRK-49F) were used to investigate the anti-fibrotic activity of PAA and its underlying mechanisms. METHODS: Western blots, qRT-PCR, immunofluorescence staining, co-immunoprecipitation and molecular docking methods were used. Knock-down and knock-in of adenosine monophosphate-activated protein kinase (AMPK) in the UUO model and cultured NRK-49F cells were employed to verify the mechanisms of action of PAA. RESULTS: PAA improved renal function and alleviated fibrosis by stimulating AMPK and inhibiting Smad3 specifically in Nx and UUO models. Reduced AMPK activity was associated with Smad3 induction, fibroblast activation, and the accumulation and aberrant remodelling of extracellular matrix (ECM) in human renal puncture samples and cultured NRK-49F cells. PAA stimulated AMPK activity and decreased fibrosis in a dose-dependent manner, thus showing that AMPK was essential for PAA to exert its anti-fibrotic effects. AMPK deficiency reduced the anti-fibrotic effects of PAA, while AMPK overexpression enhanced its effect. CONCLUSION: PAA activated AMPK and further inhibited Smad3 specifically to suppress fibrosis by preventing aberrant ECM accumulation and remodelling and facilitating the deactivation of fibroblasts.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Matriz Extracelular/efeitos dos fármacos , Nefropatias/tratamento farmacológico , Rim/patologia , Triterpenos/farmacologia , Proteínas Quinases Ativadas por AMP/química , Proteínas Quinases Ativadas por AMP/genética , Animais , Estudos de Casos e Controles , Linhagem Celular , Relação Dose-Resposta a Droga , Matriz Extracelular/patologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibrose , Humanos , Rim/efeitos dos fármacos , Rim/metabolismo , Nefropatias/metabolismo , Nefropatias/patologia , Masculino , Camundongos Endogâmicos BALB C , Simulação de Acoplamento Molecular , Ratos Sprague-Dawley , Proteína Smad3/genética , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo , Triterpenos/química , Obstrução Ureteral/tratamento farmacológico , Obstrução Ureteral/metabolismo , Obstrução Ureteral/patologia
9.
Mol Carcinog ; 59(5): 545-556, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32149414

RESUMO

Colorectal cancer (CRC) is a common malignancy. Many reports have implicated aberrant mitochondrial activity in the progression of CRC, with particular emphasis on the dysregulation of redox signaling and oxidative stress. In this study, we focused on manganese superoxide dismutase (MnSOD/SOD2), a key antioxidant enzyme, which maintains intracellular redox homeostasis. Current literature presents conflicting mechanisms for how SOD2 influences tumorigenesis and tumor progression. Here, we explored the role of SOD2 in CRC specifically. We found high levels of SOD2 expression in CRC tissues. We carried out a series of experiments to determine whether knockdown of SOD2 expression in CRC cell lines would reverse features of tumorigenesis. We found that reduced SOD2 expression decreased cell proliferation, migration, and invasion activity in CRC cells. Results from an additional series of experiments on mitochondrial function implicated a dual role for SOD2 in promoting CRC progression. First, proper level of SOD2 helped CRC cells maintain mitochondrial function by disposal of superoxide (O2 .- ). Second, over-expression of SOD2 induced H2 O2 -mediated tumorigenesis by upregulating AMPK and glycolysis. Our results indicate that SOD2 may promote the occurrence and development of CRC by regulating the energy metabolism mediated by AMPK signaling pathways.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Transformação Celular Neoplásica/patologia , Neoplasias Colorretais/patologia , Metabolismo Energético , Mitocôndrias/patologia , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Apoptose , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Movimento Celular , Proliferação de Células , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Glicólise , Humanos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Oxirredução , Estresse Oxidativo , Prognóstico , Superóxido Dismutase/genética , Células Tumorais Cultivadas
10.
Proc Natl Acad Sci U S A ; 117(14): 8013-8021, 2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32193335

RESUMO

AMP-activated protein kinase (AMPK) functions as an energy sensor and is pivotal in maintaining cellular metabolic homeostasis. Numerous studies have shown that down-regulation of AMPK kinase activity or protein stability not only lead to abnormality of metabolism but also contribute to tumor development. However, whether transcription regulation of AMPK plays a critical role in cancer metastasis remains unknown. In this study, we demonstrate that AMPKα1 expression is down-regulated in advanced human breast cancer and is associated with poor clinical outcomes. Transcription of AMPKα1 is inhibited on activation of PI3K and HER2 through ΔNp63α. Ablation of AMPKα1 expression or inhibition of AMPK kinase activity leads to disruption of E-cadherin-mediated cell-cell adhesion in vitro and increased tumor metastasis in vivo. Furthermore, restoration of AMPKα1 expression significantly rescues PI3K/HER2-induced disruption of cell-cell adhesion, cell invasion, and cancer metastasis. Together, these results demonstrate that the transcription control is another layer of AMPK regulation and suggest a critical role for AMPK in regulating cell-cell adhesion and cancer metastasis.


Assuntos
Proteínas Quinases Ativadas por AMP/genética , Neoplasias da Mama/genética , Regulação Neoplásica da Expressão Gênica , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Proteínas Quinases Ativadas por AMP/antagonistas & inibidores , Animais , Mama/patologia , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Adesão Celular/efeitos dos fármacos , Adesão Celular/genética , Linhagem Celular Tumoral , Cromonas/farmacologia , Intervalo Livre de Doença , Regulação para Baixo , Feminino , Técnicas de Silenciamento de Genes , Humanos , Lapatinib/farmacologia , Camundongos , Morfolinas/farmacologia , Estadiamento de Neoplasias , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase/farmacologia , Prognóstico , Receptor ErbB-2/antagonistas & inibidores , Receptor ErbB-2/metabolismo , Análise Serial de Tecidos , Transcrição Genética/efeitos dos fármacos , Ativação Transcricional , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Ann Rheum Dis ; 79(5): 635-645, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32156705

RESUMO

OBJECTIVES: In this study, we aim to determine the effect of metformin on osteoarthritis (OA) development and progression. METHODS: Destabilisation of the medial meniscus (DMM) surgery was performed in 10-week-old wild type and AMP-activated protein kinase (AMPK)α1 knockout (KO) mice. Metformin (4 mg/day in drinking water) was given, commencing either 2 weeks before or 2 weeks after DMM surgery. Mice were sacrificed 6 and 12 weeks after DMM surgery. OA phenotype was analysed by micro-computerised tomography (µCT), histology and pain-related behaviour tests. AMPKα1 (catalytic alpha subunit of AMPK) expression was examined by immunohistochemistry and immunofluorescence analyses. The OA phenotype was also determined by µCT and MRI in non-human primates. RESULTS: Metformin upregulated phosphorylated and total AMPK expression in articular cartilage tissue. Mild and more severe cartilage degeneration was observed at 6 and 12 weeks after DMM surgery, evidenced by markedly increased Osteoarthritis Research Society International scores, as well as reduced cartilage areas. The administration of metformin, commencing either before or after DMM surgery, caused significant reduction in cartilage degradation. Prominent synovial hyperplasia and osteophyte formation were observed at both 6 and 12 weeks after DMM surgery; these were significantly inhibited by treatment with metformin either before or after DMM surgery. The protective effects of metformin on OA development were not observed in AMPKα1 KO mice, suggesting that the chondroprotective effect of metformin is mediated by AMPK signalling. In addition, we demonstrated that treatment with metformin could also protect from OA progression in a partial medial meniscectomy animal model in non-human primates. CONCLUSIONS: The present study suggests that metformin, administered shortly after joint injury, can limit OA development and progression in injury-induced OA animal models.


Assuntos
Proteínas Quinases Ativadas por AMP/genética , Cartilagem Articular/efeitos dos fármacos , Metformina/farmacologia , Osteoartrite/tratamento farmacológico , Regulação para Cima/genética , Animais , Cartilagem Articular/patologia , Células Cultivadas , Condrócitos/efeitos dos fármacos , Condrócitos/patologia , Modelos Animais de Doenças , Progressão da Doença , Regulação da Expressão Gênica , Humanos , Hipoglicemiantes/farmacologia , Meniscos Tibiais/patologia , Meniscos Tibiais/cirurgia , Camundongos , Camundongos Knockout , Camundongos Obesos , Osteoartrite/patologia , Distribuição Aleatória , Sensibilidade e Especificidade , Transdução de Sinais/genética
12.
J Med Food ; 23(3): 266-272, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32191574

RESUMO

Mulberry (Morus alba L.) fruits have long been used in traditional medicine and as edible berries in many countries. This study investigated the antiadipogenic effect of high hydrostatic pressure mulberry fruit extract (MFE) during 3T3-L1 adipocyte differentiation. MFE decreased lipid and triglyceride accumulation and glycerol-3-phosphate dehydrogenase activity. The mRNA expression levels of genes related to adipogenesis, such as the adipocyte protein 2, proliferator-activated receptor-γ, and CCAAT/enhancer binding protein-α, were suppressed by MFE. They also reduced microRNA (miR)-21 and miR-143 expression, which are involved in adipogenesis. In contrast, adenosine monophosphate-activated protein kinase (AMPK) activity was increased by MFE. These results suggested that MFE may suppress adipogenesis through modulating miR-21/143 expression and AMPK activity in 3T3-L1 adipocytes, which may be useful as antiobesity food agents.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Adipócitos/citologia , Adipogenia/efeitos dos fármacos , MicroRNAs/genética , Morus/química , Extratos Vegetais/farmacologia , Células 3T3-L1 , Proteínas Quinases Ativadas por AMP/genética , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Animais , Fármacos Antiobesidade/química , Fármacos Antiobesidade/farmacologia , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Regulação para Baixo/efeitos dos fármacos , Frutas/química , Humanos , Camundongos , MicroRNAs/metabolismo , Obesidade/genética , Obesidade/metabolismo , PPAR gama/metabolismo , Extratos Vegetais/química , Triglicerídeos/metabolismo
13.
J Med Food ; 23(3): 250-257, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32191575

RESUMO

Obesity is a world-wide health concern with increasing mortality and morbidity rates. Development of novel therapeutic agents for obesity from phytochemicals may lead to the effective prevention and control of obesity and obesity-related complications. 6-acetyl-2,2-dimethylchroman-4-one (1) was isolated from a dietary plant, Artemisia princeps. The antiobesity effect of compound 1 was determined in human bone marrow-derived mesenchymal stromal cells (hBM-MSCs) induced to differentiate into adipocytes. Treatment with compound 1 resulted in decreased lipid accumulation and expression of key adipogenic markers, proliferator-activated receptor-γ, CCAAT/enhancer-binding protein-α, and sterol regulatory element-binding transcription factor 1. It was also shown that compound 1 downregulated the adipogenesis-induced p38 and JNK MAPK activation, while upregulating adipogenesis inhibitory ß-catenin-dependent Wnt10b pathway. Compound 1 was also able to stimulate adenosine monophosphate-activated protein kinase phosphorylation, which was suggested to be the underlying mechanism that resulted in inhibition of adipogenesis in hBM-MSCs. In conclusion, 6-acetyl-2,2-dimethylchroman-4-one was identified as a bioactive constituent of A. princeps that exerts antiobesity properties via suppressing adipocyte formation.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Adipócitos/citologia , Adipogenia/efeitos dos fármacos , Artemisia/química , Medicamentos de Ervas Chinesas/farmacologia , Células-Tronco Mesenquimais/citologia , Obesidade/fisiopatologia , Proteínas Quinases Ativadas por AMP/genética , Adipócitos/metabolismo , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Diferenciação Celular/efeitos dos fármacos , Medicamentos de Ervas Chinesas/química , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Obesidade/tratamento farmacológico , Obesidade/genética , Obesidade/metabolismo , PPAR gama/genética , PPAR gama/metabolismo , Transdução de Sinais/efeitos dos fármacos
14.
J Med Food ; 23(3): 312-318, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32191579

RESUMO

The aim of this study was to investigate the efficacy of an ethanol extract of Physalis alkekengi (PA) and its mechanistic pathway of action at the molecular level for its antiobesity properties. Four-week old male Institute of Cancer Research (ICR) mice were acclimatized for a week before starting the high-fat diet (HFD) for 2 weeks to induce obesity, followed by 8 more weeks of oral administration of 10 mg/kg orlistat and 300 mg/kg of PA extract, along with HFD. Body weights of the mice and feed and water intake were recorded weekly. After a total of 12 weeks, mice were euthanized, and blood, liver, and adipose tissues were harvested for further analysis. Administration of PA extract inhibited the progression of obesity by reducing weight gain, weight of adipose tissue, and normalizing serum triglyceride, glucose, total cholesterol, high-density lipoprotein, low-density lipoprotein, alanine aminotransferase, and aspartate aminotransferase. PA extract prevented the progression of nonalcoholic steatohepatitis induced by HFD and prevented the enlargement of liver. Phosphorylation of adenosine monophosphate-activated protein kinase α increased while phosphorylation of acetyl-CoA carboxylase was reduced. The browning gene uncoupling protein 1 expression was also increased by PA extract treatment. Our findings revealed that the antiobesity properties of PA extract may be mediated by browning of white adipose tissue.


Assuntos
Tecido Adiposo Branco/metabolismo , Fármacos Antiobesidade/administração & dosagem , Obesidade/tratamento farmacológico , Physalis/química , Extratos Vegetais/administração & dosagem , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Acetil-CoA Carboxilase/genética , Acetil-CoA Carboxilase/metabolismo , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/efeitos dos fármacos , Animais , Dieta Hiperlipídica/efeitos adversos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Obesidade/genética , Obesidade/metabolismo , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
15.
Life Sci ; 248: 117474, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32112869

RESUMO

BACKGROUND/OBJECTIVES: Nicotinamide N-methyltransferase (NNMT) is a novel regulator of energy homeostasis in adipocytes. NNMT expression in adipose tissue is increased in obesity and diabetes. Knockdown of NNMT prevents mice from developing diet-induced obesity, which is closely linked to insulin resistance. An early sign of systemic insulin resistance is reduced expression of glucose transporter 4 (GLUT4) selectively in adipose tissue. Adipose tissue-specific knockout and overexpression of GLUT4 cause reciprocal changes in NNMT expression. The aim of the current study was to elucidate the mechanism that regulates NNMT expression in adipocytes. METHODS: 3T3-L1 adipocytes were cultured in media with varying glucose concentrations or activators and inhibitors of intracellular pathways. NNMT mRNA and protein levels were measured with quantitative polymerase chain reaction and Western blotting. RESULTS: Glucose deprivation of 3T3-L1 adipocytes induced a 2-fold increase in NNMT mRNA and protein expression. This effect was mimicked by inhibition of glucose transport with phloretin, and by inhibition of glycolysis with the phosphoglucose isomerase inhibitor 2-deoxyglucose. Conversely, inhibition of the pentose phosphate pathway did not affect NNMT expression. Pharmacological activation of the cellular energy sensor AMP-activated protein kinase (AMPK) and inhibition of the mammalian target of rapamycin (mTOR) pathway caused an increase in NNMT levels that was similar to the effect of glucose deprivation. Activation of mTOR with MHY1485 prevented the effect of glucose deprivation on NNMT expression. Furthermore, upregulation of NNMT levels depended on functional autophagy and protein translation. CONCLUSION: Glucose availability regulates NNMT expression via an mTOR-dependent mechanism.


Assuntos
Adipócitos/efeitos dos fármacos , Transportador de Glucose Tipo 4/genética , Glucose/farmacologia , Nicotinamida N-Metiltransferase/genética , Serina-Treonina Quinases TOR/genética , Células 3T3-L1 , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Adipócitos/citologia , Adipócitos/metabolismo , Animais , Autofagia/efeitos dos fármacos , Autofagia/genética , Transporte Biológico/efeitos dos fármacos , Diferenciação Celular , Desoxiglucose/farmacologia , Metabolismo Energético/genética , Regulação da Expressão Gênica , Glucose/metabolismo , Transportador de Glucose Tipo 4/antagonistas & inibidores , Transportador de Glucose Tipo 4/metabolismo , Glucose-6-Fosfato Isomerase/antagonistas & inibidores , Glucose-6-Fosfato Isomerase/genética , Glucose-6-Fosfato Isomerase/metabolismo , Homeostase/genética , Camundongos , Morfolinas/farmacologia , Nicotinamida N-Metiltransferase/antagonistas & inibidores , Nicotinamida N-Metiltransferase/metabolismo , Via de Pentose Fosfato/efeitos dos fármacos , Via de Pentose Fosfato/genética , Floretina/farmacologia , Biossíntese de Proteínas , RNA Mensageiro/antagonistas & inibidores , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Triazinas/farmacologia
16.
Biochem Biophys Res Commun ; 524(4): 853-860, 2020 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-32046856

RESUMO

Telmisartan, an angiotensin II type 1 receptor blocker (ARB), is widely used to treat hypertension. Dysfunction of vascular smooth muscle cells (VSMCs) is well-established to contribute to the pathogenesis of various vascular diseases. A growing body of evidence indicates that increased VSMC contractility plays a primary role in the development of pathological artery spasms. Nevertheless, effect of telmisartan on VSMC contractility, and its mechanism of action remain unknown. Here, we investigated the mechanism by which telmisartan inhibits VSMC contractility and vessel contraction in rat VSMCs and endothelium-deprived aortas. Telmisartan inhibited phenylephrine-induced vessel contraction in endothelium-deprived aortas, and decreased myosin light chain kinase (MLCK) levels (without altering corresponding mRNA levels) and myosin light chain (MLC) phosphorylation at Ser19 (p-MLC-Ser19) in VSMCs. MG-132 but not doxycycline significantly restored telmisartan-inhibited MLCK expression and p-MLC-Ser19. Telmisartan induced AMP-activated protein kinase (AMPK) phosphorylation at Thr172 (p-AMPK-Thr172), and compound C or ectopic expression of the dominant negative (dn)-AMPKα1 gene significantly reversed telmisartan-inhibited MLCK expression and p-MLC-Ser19. Of the ARBs tested (including losartan and fimasartan), only telmisartan increased p-AMPK-Thr172, and inhibited MLCK expression and p-MLC-Ser19. GW9662 had no effects on telmisartan-induced changes. Similar to the in vitro results, telmisartan enhanced p-AMPK-Thr172, and inhibited MLCK expression and p-MLC-Ser19 in endothelium-deprived aortas. Furthermore, the telmisartan-inhibited vessel contraction in the aortas was significantly reversed by MG-132 or compound C. In conclusion, we demonstrated that telmisartan inhibits VSMC contractility and vessel contraction by activating AMPK/proteasome/MLCK degradation signaling axis. These results suggest that telmisartan can be used to treat pathological vasospasms.


Assuntos
Proteínas Quinases Ativadas por AMP/genética , Anti-Hipertensivos/farmacologia , Contração Muscular/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Quinase de Cadeia Leve de Miosina/genética , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Telmisartan/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Aorta/citologia , Aorta/efeitos dos fármacos , Aorta/metabolismo , Doxiciclina/farmacologia , Regulação da Expressão Gênica , Leupeptinas/farmacologia , Masculino , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/metabolismo , Quinase de Cadeia Leve de Miosina/metabolismo , Fenilefrina/antagonistas & inibidores , Fenilefrina/farmacologia , Fosforilação/efeitos dos fármacos , Cultura Primária de Células , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Vasoconstritores/antagonistas & inibidores , Vasoconstritores/farmacologia
17.
Nat Cell Biol ; 22(2): 225-234, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32029897

RESUMO

Energy stress depletes ATP and induces cell death. Here we identify an unexpected inhibitory role of energy stress on ferroptosis, a form of regulated cell death induced by iron-dependent lipid peroxidation. We found that ferroptotic cell death and lipid peroxidation can be inhibited by treatments that induce or mimic energy stress. Inactivation of AMP-activated protein kinase (AMPK), a sensor of cellular energy status, largely abolishes the protective effects of energy stress on ferroptosis in vitro and on ferroptosis-associated renal ischaemia-reperfusion injury in vivo. Cancer cells with high basal AMPK activation are resistant to ferroptosis and AMPK inactivation sensitizes these cells to ferroptosis. Functional and lipidomic analyses further link AMPK regulation of ferroptosis to AMPK-mediated phosphorylation of acetyl-CoA carboxylase and polyunsaturated fatty acid biosynthesis. Our study demonstrates that energy stress inhibits ferroptosis partly through AMPK and reveals an unexpected coupling between ferroptosis and AMPK-mediated energy-stress signalling.


Assuntos
Proteínas Quinases Ativadas por AMP/genética , Acetil-CoA Carboxilase/genética , Ferroptose/genética , Rim/enzimologia , Peroxidação de Lipídeos/genética , Traumatismo por Reperfusão/genética , Células A549 , Proteínas Quinases Ativadas por AMP/antagonistas & inibidores , Proteínas Quinases Ativadas por AMP/metabolismo , Acetil-CoA Carboxilase/metabolismo , Animais , Linhagem Celular Tumoral , Cicloexilaminas/farmacologia , Embrião de Mamíferos , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/genética , Ácidos Graxos Insaturados/biossíntese , Ferroptose/efeitos dos fármacos , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Glucose/deficiência , Glucose/farmacologia , Humanos , Ferro/metabolismo , Rim/efeitos dos fármacos , Rim/patologia , Peroxidação de Lipídeos/efeitos dos fármacos , Células MCF-7 , Camundongos , Camundongos Transgênicos , Fenilenodiaminas/farmacologia , Fosforilação , Piperazinas/antagonistas & inibidores , Piperazinas/farmacologia , Cultura Primária de Células , Pirazóis/farmacologia , Pirimidinas/farmacologia , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/patologia , Transdução de Sinais , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética
18.
Science ; 367(6478): 652-660, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-32029622

RESUMO

Liver cell death has an essential role in nonalcoholic steatohepatitis (NASH). The activity of the energy sensor adenosine monophosphate (AMP)-activated protein kinase (AMPK) is repressed in NASH. Liver-specific AMPK knockout aggravated liver damage in mouse NASH models. AMPK phosphorylated proapoptotic caspase-6 protein to inhibit its activation, keeping hepatocyte apoptosis in check. Suppression of AMPK activity relieved this inhibition, rendering caspase-6 activated in human and mouse NASH. AMPK activation or caspase-6 inhibition, even after the onset of NASH, improved liver damage and fibrosis. Once phosphorylation was decreased, caspase-6 was activated by caspase-3 or -7. Active caspase-6 cleaved Bid to induce cytochrome c release, generating a feedforward loop that leads to hepatocyte death. Thus, the AMPK-caspase-6 axis regulates liver damage in NASH, implicating AMPK and caspase-6 as therapeutic targets.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Caspase 6/metabolismo , Fígado/enzimologia , Fígado/patologia , Hepatopatia Gordurosa não Alcoólica/enzimologia , Hepatopatia Gordurosa não Alcoólica/patologia , Proteínas Quinases Ativadas por AMP/genética , Animais , Apoptose/genética , Caspase 3/metabolismo , Caspase 7/metabolismo , Inibidores de Caspase/farmacologia , Inibidores de Caspase/uso terapêutico , Ativação Enzimática , Hepatócitos/enzimologia , Hepatócitos/patologia , Humanos , Camundongos , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Fosforilação
19.
J Agric Food Chem ; 68(9): 2673-2683, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32050765

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is rapidly becoming the leading cause of chronic liver diseases throughout the world. The deficit of pharmacotherapy for NAFLD calls for an urgent need for a new drug discovery and lifestyle management. Black tea is the most popular and functional drink consumed worldwide. Its main bioactive constituent theaflavin helps to prevent obesity-a major risk factor for NAFLD. To find new targets for the development of effective and safe therapeutic drugs from natural plants for NAFLD, we found a theaflavin monomer theaflavin-3,3'-digallate (TF3), which significantly reduced lipid droplet accumulation in hepatocytes, and directly bound and inhibited the activation of plasma kallikrein (PK), which was further proved to stimulate adenosine monophosphate activated protein kinase (AMPK) and its downstream targets. Taken together, we proposed that the TF3-PK-AMPK regulatory axis is a novel mechanism of lipid deposition mitigation, and PK could be a new target for NAFLD treatment.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Biflavonoides/farmacologia , Catequina/farmacologia , Hepatócitos/metabolismo , Gotículas Lipídicas/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Extratos Vegetais/farmacologia , Calicreína Plasmática/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Apoptose/efeitos dos fármacos , Camellia sinensis/química , Células Hep G2 , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Humanos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Transdução de Sinais/efeitos dos fármacos
20.
J Immunol ; 204(5): 1322-1333, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-31996460

RESUMO

With the development of liver surgery, ischemia-reperfusion (IR) injury has received increasing attention. Roquin-1 has been shown to play an important role in innate immune and immune balance. We demonstrate that Roquin-1 expression increased at 1 h after IR and then decreased in C57B/L mice. The immunofluorescence double-label showed that Roquin-1 was mainly expressed in macrophages (mø). Furthermore, we used clodronate liposomes to remove mø, and injected the bone marrow-derived mø (BMDM) through the tail vein in 1 h before IR. We found that liver IR injury was aggravated by Roquin-1 interference. The results of PCR and ELISA suggested that after interference with Roquin-1, mø increased toward M1 and decreased toward M2. Then, interference with Roquin-1 promoted the polarization of mø to M1 and inhibited the polarization of M2. By Western blot technology and AMPKα and mTOR inhibitors, we found that Roquin-1 promotes the phosphorylation of mTOR and STAT3 by inhibiting the phosphorylation of AMPKα. We used AICAR to activate AMPKα in mø and found that the level of ubiquitination of AMPKα was decreased after activation of AMPKα. Furthermore, by bioinformatics methods, we identified potential ubiquitination sites on AMPKα. By the point mutation experiments in vitro, we confirmed that the ubiquitination of these sites is regulated by Roquin-1. Meanwhile, Roquin-1 interference inhibited the activation and function of AMPKα. This topic describes the protection of liver IR injury by Roquin-1 and discusses its main mechanism for regulating AMPKα activity through ubiquitination and affecting the polarization of mø.


Assuntos
Hepatopatias/imunologia , Fígado/imunologia , Macrófagos/imunologia , Traumatismo por Reperfusão/imunologia , Ubiquitina-Proteína Ligases/imunologia , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/imunologia , Animais , Ativação Enzimática/imunologia , Regulação da Expressão Gênica/genética , Regulação da Expressão Gênica/imunologia , Fígado/patologia , Hepatopatias/genética , Hepatopatias/patologia , Macrófagos/patologia , Masculino , Camundongos , Mutação Puntual , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/patologia , Ubiquitina-Proteína Ligases/genética , Ubiquitinação/genética , Ubiquitinação/imunologia
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