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1.
Int Heart J ; 61(5): 1022-1033, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32999189

RESUMO

Cardiac hypertrophy is one of the significant risk factors that result in maladaptive cardiac remodeling and heart failure, and exercise is known to exert cardioprotection. In this research, the cardioprotective function and exercise mechanisms were explored.The rats underwent transverse aortic constriction (TAC) or a sham operation. The rats that received TAC were randomly assigned to five groups: (1) rats subjected to a sham operation as control group (SC), (2) rats that underwent TAC group (TC), (3) TAC and moderate-intensity exercise group (TE), (4) TE plus 3-MA group (TEM), and (5) TE plus Compound C group (TEC). The heart function was measured via echocardiography. Histological analysis and relative protein testing were conducted to analyze collagen deposition and apoptosis. Furthermore, western blot was employed to measure the protein expression of relevant signaling pathways. Impaired cardiac function, interstitial fibrosis, enhanced apoptosis, and ER stress were observed in the TAC-induced left ventricular hypertrophy. Exercise attenuated TAC-induced cardiac dysfunction, interstitial fibrosis, and ER stress-related apoptosis. In addition, exercise significantly improved autophagy and upregulated AMPK phosphorylation. Furthermore, AMPK inhibitor Compound C repressed the activation of AMPK, and autophagy inhibitor 3-methyladenine reversed exercise-induced autophagy. All of these abolished the protection of exercise against cardiac dysfunction and fibrosis induced by TAC.Our results indicated that 4 weeks of treadmill exercise could alleviate pressure overload-induced LV dysfunction and remodeling via an autophagy-dependent mechanism, which was induced by enhancing autophagy through the activation of AMPK.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Autofagia , Hipertrofia Ventricular Esquerda/reabilitação , Condicionamento Físico Animal/fisiologia , Disfunção Ventricular Esquerda/reabilitação , Animais , Apoptose , Modelos Animais de Doenças , Estresse do Retículo Endoplasmático , Feminino , Distribuição Aleatória , Ratos Wistar , Remodelação Ventricular
2.
PLoS One ; 15(9): e0235960, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32986718

RESUMO

OBJECTIVE: To investigate the effects of AMPK activation on mitochondrial inhibition by uremic serum through the AMPK-activated rat peritoneal macrophages stimulated by uremic serum, thereby providing a reference for the clinical treatment of chronic kidney disease. METHODS: Twenty-two male Sprague-Dawley (SD) rats were included as experimental subjects. Fifteen rats were constructed into chronic kidney disease models (the model group). The remaining seven rats only received renal capsule stripping instead of nephrectomy (the sham-operated group). Ten weeks after model construction, the bodyweight, blood biochemical indicators, and metabolic parameters of rats in groups were measured. Meanwhile, the expression of the M1 phenotype marker protein in peritoneal macrophages was determined. RESULTS: Ten weeks after model construction, the bodyweight of rats in the model group was significantly lower than that in the sham-operated group. The values of urea nitrogen and serum creatinine were significantly higher than those in the sham-operated group (P<0.01). The levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and the monocyte chemoattractant protein 1 (MCP-1) of rats in the model group were significantly higher than those in the sham-operated group (P <0.01). After the lipopolysaccharide (LPS) stimulation, the expressions of M1 phenotype marker mRNA in the model group was significantly increased. The expression of mitochondrial structural protein mRNA in the peritoneal macrophages of rats in the model group was significantly lower than that in the sham-operated group. The expression of M1 phenotype marker mRNA was significantly decreased in the uremic serum group after AMPK agonist (P<0.01). CONCLUSION: In rats with chronic renal insufficiency, mitochondrial regeneration was dysfunctional in macrophages. By activating AMPK, the inhibitory effect of uremia serum on mitochondrial regeneration of macrophages was improved. Therefore, AMPK was a critical factor that could regulate mitochondrial regeneration of macrophages.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Ativação Enzimática , Macrófagos Peritoneais/metabolismo , Mitocôndrias/metabolismo , Uremia/metabolismo , Animais , Macrófagos Peritoneais/patologia , Masculino , Mitocôndrias/patologia , Dinâmica Mitocondrial , RNA Mensageiro/metabolismo , RNA Mitocondrial/metabolismo , Ratos , Ratos Sprague-Dawley , Uremia/sangue , Uremia/patologia
3.
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
4.
PLoS Biol ; 18(6): e3000732, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32603375

RESUMO

Coordination of gene expression with nutrient availability supports proliferation and homeostasis and is shaped by protein acetylation. Yet how physiological/pathological signals link acetylation to specific gene expression programs and whether such responses are cell-type-specific is unclear. AMP-activated protein kinase (AMPK) is a key energy sensor, activated by glucose limitation to resolve nutrient supply-demand imbalances, critical for diabetes and cancer. Unexpectedly, we show here that, in gastrointestinal cancer cells, glucose activates AMPK to selectively induce EP300, but not CREB-binding protein (CBP). Consequently, EP300 is redirected away from nuclear receptors that promote differentiation towards ß-catenin, a driver of proliferation and colorectal tumorigenesis. Importantly, blocking glycogen synthesis permits reactive oxygen species (ROS) accumulation and AMPK activation in response to glucose in previously nonresponsive cells. Notably, glycogen content and activity of the ROS/AMPK/EP300/ß-catenin axis are opposite in healthy versus tumor sections. Glycogen content reduction from healthy to tumor tissue may explain AMPK switching from tumor suppressor to activator during tumor evolution.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Neoplasias Colorretais/metabolismo , Proteína p300 Associada a E1A/metabolismo , Glucose/farmacologia , Animais , Proteína de Ligação a CREB/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/patologia , Ativação Enzimática/efeitos dos fármacos , Glicogênio/metabolismo , Camundongos Endogâmicos C57BL , Ligação Proteica/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , beta Catenina/metabolismo
5.
Nat Rev Endocrinol ; 16(9): 495-505, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32632275

RESUMO

Exercise is fundamental for good health, whereas physical inactivity underpins many chronic diseases of modern society. It is well appreciated that regular exercise improves metabolism and the metabolic phenotype in a number of tissues. The phenotypic alterations observed in skeletal muscle are partly mediated by transcriptional responses that occur following each individual bout of exercise. This adaptive response increases oxidative capacity and influences the function of myokines and extracellular vesicles that signal to other tissues. Our understanding of the epigenetic and transcriptional mechanisms that mediate the skeletal muscle gene expression response to exercise as well as of their upstream signalling pathways has advanced substantially in the past 10 years. With this knowledge also comes the opportunity to design new therapeutic strategies based on the biology of exercise for a variety of chronic conditions where regular exercise might be a challenge. This Review provides an overview of the beneficial adaptive responses to exercise and details the molecular mechanisms involved. The possibility of designing therapeutic interventions based on these molecular mechanisms is addressed, using relevant examples that have exploited this approach.


Assuntos
Doença Crônica/prevenção & controle , Exercício Físico/fisiologia , Promoção da Saúde , Proteínas Quinases Ativadas por AMP/metabolismo , Adaptação Fisiológica , Animais , Glândulas Endócrinas/fisiologia , Epigênese Genética , Expressão Gênica , Histona Desacetilases/metabolismo , Humanos , Músculo Esquelético/fisiologia , Condicionamento Físico Animal/fisiologia , Transdução de Sinais/fisiologia , Transcrição Genética/fisiologia
6.
Gene ; 758: 144973, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-32707303

RESUMO

Renal ischemia-reperfusion (rI/R) is a risk factor for acute lung injury (ALI). Alveolar macrophages (AMs) activation mediated by rI/R-induced ALI is one of the pathogeneses associated with the development of ALI. In rI/R, α2-adrenergic receptor agonists have been indicated to be effective in decreasing urea nitrogen concentrations. In this study, we explored the underlying pathogenesis of the clinically obtainable α2-adrenergic receptor agonist dexmedetomidine (DEX) in protecting against rI/R -mediated AMs activation. We incubated AMs with the serum of sham and rI/R rats in the presence or absence of various concentrations of DEX. We used an enzyme-linked immunosorbent assay to detect the secretion levels of GSH, LDH, IL-18, IL-1ß, and HMGB1 in the culture supernatant. We employed real-time polymerase chain reaction to assess the expression of NOX-4 mRNA, and western blotting to observe the protein levels of NOX-4, the NLRP3 inflammasome, AMPK, and eNOS. In addition, we used immunofluorescence to analyze ROS and MMP activity. Incubation of AMs with DEX suppressed rI/R-mediated cellular LDH production and ROS release. DEX also abolished the rI/R-mediated decrease in the activity of GSH and increased the levels of the rI/R-related NADPH oxidase protein NOX-4. Furthermore, DEX reduced the amelioration of the mitochondrial potential induced by rI/R. Our study showed that DEX inhibits rI/R-mediated levels of the NLRP3 inflammasome proteins ASC, NLRP3, HMGB1 and p20, and ameliorates rI/R-mediated AMPK signaling inactivation. Therefore, DEX reduces the levels of two mediators that are activated by the NLRP3 inflammasome: IL-18 and IL-1ß. Finally, our study established that DEX mitigates the rI/R-mediated decrease in eNOS, demonstrating its protective functions against AMs activation. In conclusion, our study demonstrated that the protective action of DEX in AMs is induced through amelioration of HMGB1-NLRP3 inflammasome-AMPK signaling. Our results suggest that the anesthetic reagent DEX exerts beneficial effects to ameliorate rI/R-induced ALI.


Assuntos
Lesão Renal Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/prevenção & controle , Agonistas de Receptores Adrenérgicos alfa 2/farmacologia , Dexmedetomidina/farmacologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Traumatismo por Reperfusão/tratamento farmacológico , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Linhagem Celular , Ensaio de Imunoadsorção Enzimática , Proteína HMGB1/metabolismo , Isquemia/patologia , Macrófagos Alveolares/patologia , NADPH Oxidase 4/biossíntese , NADPH Oxidase 4/genética , Óxido Nítrico Sintase Tipo III/metabolismo , RNA Mensageiro/genética , Ratos , Reação em Cadeia da Polimerase em Tempo Real
7.
PLoS Comput Biol ; 16(7): e1008079, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32730244

RESUMO

Exercise training elicits profound metabolic adaptations in skeletal muscle cells. A key molecule in coordinating these adaptations is AMP-activated protein kinase (AMPK), whose activity increases in response to cellular energy demand. AMPK activity dynamics are primarily controlled by the adenine nucleotides ADP and AMP, but how each contributes to its control in skeletal muscle during exercise is unclear. We developed and validated a mathematical model of AMPK signaling dynamics, and then applied global parameter sensitivity analyses with data-informed constraints to predict that AMPK activity dynamics are determined principally by ADP and not AMP. We then used the model to predict the effects of two additional direct-binding activators of AMPK, ZMP and Compound 991, further validating the model and demonstrating its applicability to understanding AMPK pharmacology. The relative effects of direct-binding activators can be understood in terms of four properties, namely their concentrations, binding affinities for AMPK, abilities to enhance AMPK phosphorylation, and the magnitudes of their allosteric activation of AMPK. Despite AMP's favorable values in three of these four properties, ADP is the dominant controller of AMPK activity dynamics in skeletal muscle during exercise by virtue of its higher concentration compared to that of AMP.


Assuntos
Proteínas Quinases Ativadas por AMP , Difosfato de Adenosina , Exercício Físico/fisiologia , Músculo Esquelético , Proteínas Quinases Ativadas por AMP/química , Proteínas Quinases Ativadas por AMP/metabolismo , Difosfato de Adenosina/química , Difosfato de Adenosina/metabolismo , Difosfato de Adenosina/farmacocinética , Animais , Biologia Computacional , Humanos , Camundongos , Modelos Biológicos , Músculo Esquelético/enzimologia , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiologia , Transdução de Sinais/fisiologia
8.
Life Sci ; 257: 118120, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32693244

RESUMO

AIMS: Catalpol (Cat) can ameliorate oxide stress and inflammation caused by diabetic nephropathy (DN), but the molecular mechanisms are unclear. This study was designed to investigate the anti-diabetic effects of Cat and its potential mechanism. MAIN METHODS: We constructed high-fat diet/streptozotocin (HFD/STZ)-induced DN mice and high glucose (HG)-induced podocyte model. The hypoglycemic effect of Cat was analyzed by general features of DN mice. Kidney function was detected via ELISA assay and Western blotting. Renal histopathology analysis was conducted via hematoxylin and eosin (H&E), Masson and periodic acid-silver metheramine (PASM) staining. Cellular viability was measured by TUNEL assay. In order to further study the potential mechanisms of Cat, various proteins in AMPK/SIRT1/NF-κB pathway were detected in DN mice and podocytes with siRNA-AMPK intervention using Western blotting, respectively. KEY FINDINGS: We found hyperglycemia, renal structural and function abnormalities, and increased renal inflammation in DN mice. However, Cat effectively attenuated kidney damage caused by inflammation and increased AMPK, p-AMPK and SIRT1 levels. After AMPK-siRNA transfected into HG-induced podocyte model, AMPK, p-AMPK and SIRT1 levels were obviously decreased, while Cat reversed these chandes. The levels of p-NF-κB, ASC, Cleaved IL-1ß, NLRP3, Cleaved caspase1 and GSDMD-N significantly decreased by Cat treatment both in DN mice and podocyte model, which indicated that Cat could activate AMPK/SIRT1/NF-κB pathway. SIGNIFICANCE: Cat could effectively inhibit oxide stress and inflammation accompanied with pyroptosis and its mechanism might be related to AMPK/SIRT1/NF-κB pathway, indicating that Cat possessed potential value in the treatment of DN.


Assuntos
Nefropatias Diabéticas/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Glucosídeos Iridoides/uso terapêutico , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Western Blotting , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/tratamento farmacológico , Nefropatias Diabéticas/patologia , Ensaio de Imunoadsorção Enzimática , Rim/efeitos dos fármacos , Rim/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Sirtuína 1/metabolismo
9.
Life Sci ; 257: 118122, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32702446

RESUMO

AIMS: Berberine is an isoquinoline alkaloid extracted from the root, rhizome and stem bark of Coptidis Rhizoma. Previous studies have revealed the anti-tumor potential of berberine against various types of cancer cells. However, the underlying mechanisms are not yet fully understood. In this study, we focused on the effects of berberine on fatty acid synthesis and extracellular vesicles formation in cancer cells, and revealed the internal mechanism of berberine inhibition on cancer cell proliferation. MATERIALS AND METHODS: Anti-proliferative activity of berberine was determined by cell counting and microscope observation and cell cycle analysis. Activities of AMPK and ACC, expression of extracellular vesicles markers were detected by western blotting. 13C labeling metabolic flux analysis was used for determination of de novo synthesis of fatty acids. The excreted extracellular vesicles in culture mediums were separated by both polyethylene glycol enrichment of extracellular vesicles and differential centrifugation separation. KEY FINDINGS: Among our early experiments, 5-10 µmol/L berberine exhibited the substantial anti-proliferative effect against human colon cancer cell line HCT116, cervical cancer cell line HeLa and other cancer cells. It was also revealed that, through activating AMPK, berberine inhibited ACC activity then suppressed intracellular fatty acid synthesis, finally decreased the biogenesis of extracellular vesicles. Moreover, supplement with citrate acid, palmitic acid, as well as exogenous extracellular vesicles, could rescue the inhibitory effect of berberine on cell proliferation, suggesting that inhibited ACC activity, suppressed fatty acid synthesis and decreased extracellular vesicles production were important mechanisms account for berberine inhibiting cancer cell proliferation. SIGNIFICANCE: Our study indicates that berberine suppresses cancer cell proliferation through inhibiting the synthesis of fatty acids and decreasing biogenesis and secretion of extracellular vesicles, suggests that berberine is a promising candidate for the development of new therapies for cancer.


Assuntos
Antineoplásicos/farmacologia , Berberina/farmacologia , Vesículas Extracelulares/metabolismo , Ácidos Graxos/metabolismo , Neoplasias/tratamento farmacológico , Proteínas Quinases Ativadas por AMP/metabolismo , Acetil-CoA Carboxilase/metabolismo , Western Blotting , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Ácido Cítrico/farmacologia , Vesículas Extracelulares/efeitos dos fármacos , Células HCT116/efeitos dos fármacos , Células HeLa/efeitos dos fármacos , Humanos
10.
Life Sci ; 257: 118040, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32622943

RESUMO

AIMS: Timosaponin AIII (TAIII), an active component with anti-tumor activity from Anemarrhena asphodeloides Bunge, can induce both autophagy and apoptosis of cancer cells. The present study aimed to reveal the promoting or inhibiting role of TAIII-induced autophagy on TAIII-induced apoptosis, to determine the respective upstream signaling pathways for TAIII-induced autophagy and apoptosis; and to observe the therapeutic potential of TAIII in human non-small cell lung cancer in vivo. METHODS AND MATERIALS: WST-1 assay was used to determine the effect of TAIII on cell growth and proliferation. Apoptosis was detected by DAPI staining and flow cytometry. Autophagy was verified by immunofluorescence and transmission electron microscopy. Western blot was used to determine the levels of protein expression. Furthermore, the anti-tumor activity of TAIII was observed in nude mice. KEY FINDINGS: TAIII at high concentrations from 10 µM to 30 µM induced both autophagy and apoptosis in human non-small cell lung cancer cells in a time- and concentration-dependent manner. TAIII at low concentration (1 µM) only induced autophagy. The AMP-activated protein kinase (AMPK) signaling pathway was identified to be responsible for TAIII-induced autophagy both at high or low concentrations. The MAPK/Erk1/2 signaling pathway was identified to be responsible for TAIII-induced apoptosis at the high concentration (20 µM). TAIII-induced autophagy protected cancer cells from apoptosis, and combination of TAIII and autophagy inhibitor showed higher anti-cancer activity.


Assuntos
Autofagia/efeitos dos fármacos , Neoplasias Pulmonares/metabolismo , Saponinas/farmacologia , Esteroides/farmacologia , Células A549 , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Antineoplásicos , Apoptose/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Sistema de Sinalização das MAP Quinases , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Saponinas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Esteroides/metabolismo
11.
Life Sci ; 256: 117990, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32574665

RESUMO

AIM: Luteolin and lycopene are common natural products, widely existing in nature, and both of which were reported to have various biological functions including anti-inflammatory, anti-obesity and anti-NAFLD. In the present study, we aimed to evaluate the therapeutic efficacy of luteolin and lycopene in combination and its latent molecular mechanisms in vitro and in vivo models of NAFLD. MAIN METHODS: Sodium palmitate (PA)-induced steatotic HepG2 cells and primary hepatocytes, and high-fat diet-induced C57BL/6J obese mice were treated with luteolin, lycopene and their combination. Metabolic parameters were measured. KEY FINDINGS: We found that luteolin (20 µM) + lycopene (10 µM) was the best therapeutic combination in PA-induced HepG2 cells, and significantly improve cell viability and lipid accumulation in PA-induced HepG2 cells and primary hepatocytes. In addition, luteolin (20 mg/kg) + lycopene (20 mg/kg) could ameliorate increased body weight and hepatocyte steatosis; regulate serum triglycerides, serum total cholesterol, hepatic triglycerides and hepatic total cholesterol; decrease serum alanine transaminase and aspartate transaminase. Furthermore, in vivo and in vitro, luteolin, lycopene and their combination had no effect on Sirt1 expression, but all of them could upregulate the expression of NAMPT, which could increase the level of NAD+, the co-substrate of Sirt1, indirectly activating Sirt1/AMPK pathway, and then inhibited lipogenesis and increased ß-oxidation, defensing the "first hit"; they also inactivated nuclear factor-κB (NF-κB) and decreased the levels of IL-6, IL-1ß and TNF-α, defensing the "second hit". SIGNIFICANCE: Thus, luteolin and lycopene in combination can effectively ameliorate "two-hit" in NAFLD through activation of the Sirt1/AMPK pathway.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Luteolina/administração & dosagem , Licopeno/administração & dosagem , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Sirtuína 1/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Dieta Hiperlipídica/efeitos adversos , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Células Hep G2 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/etiologia , Substâncias Protetoras/administração & dosagem , Distribuição Aleatória
12.
Life Sci ; 256: 117997, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32585242

RESUMO

AIMS: Non-alcoholic fatty liver disease (NAFLD) characterized by excessive hepatic fat deposition is an increasing public health issue worldwide. Insulin resistance is a pivotal factor in NAFLD progression. Studies have found that IGFBP5 was related to insulin sensitivity. Nevertheless, the role of IGFBP5 in NAFLD remains unclear. MATERIALS AND METHODS: NAFLD models were established in vitro and in vivo by treating HepG2 cells with free fatty acids (FFA) and feeding mice with high-fat diet (HFD), respectively. IGFBP5 expression was then analyzed in these models. The effects and mechanism of IGFBP5 on lipid lipogenesis, fatty acid ß-oxidation, and insulin resistance were investigated following IGFBP5 overexpression. Additionally, AMPK inhibitor compound C was used to treat HepG2 cells to confirm whether IGFBP5 functioned via activating AMPK pathway. KEY FINDINGS: IGFBP5 expression was decreased in both NAFLD models. IGFBP5 overexpression reduced levels of lipogenesis-associated proteins (SREBP-1c, FAS and ACC1), elevated expression of fatty acid ß-oxidation-related genes (PPARα, CPT1A and ACOX1), decreased intracellular lipid droplets, promoted glucose uptake and glycogenesis, and activated IRS1/Akt and AMPK pathways. Administration of IGFBP5 vectors also decreased body weight and relieved liver damage in HFD-treated mice. In contrast, compound C abrogated the influences of IGFBP5 overexpression on cell models. SIGNIFICANCE: IGFBP5 dampened hepatic lipid accumulation and insulin resistance in NAFLD development via activating AMPK pathway. This study indicates that IGFBP5 may be a novel therapeutic agent for NAFLD.


Assuntos
Resistência à Insulina/genética , Proteína 5 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Metabolismo dos Lipídeos/genética , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Proteínas de Transporte/genética , Dieta Hiperlipídica , Modelos Animais de Doenças , Ácidos Graxos não Esterificados/administração & dosagem , Regulação da Expressão Gênica , Células Hep G2 , Humanos , Lipogênese/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/genética
13.
Chemosphere ; 259: 127448, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32593828

RESUMO

Ivermectin (IVM), a broad-spectrum antiparasitic drug, is widely used in agriculture and animal husbandry. Due to widespread use and little metabolism in animals, the toxicity of IVM has received increasing attention. The accumulation of IVM in animal tissues and the excretion of urine and feces in the environment is the major source of potential toxicity. Human consumption of meat or milk contaminated with livestock can result in exposure to high levels of IVM exposure. The aim of this study was to reveal the cytotoxic mechanism of IVM in model cell HeLa in vitro, in order to provide a theoretical basis for the safe and rational use of IVM. Here we observed the γH2AX and 8-oxodG foci to detect the DNA damage in HeLa cells. As expected, we found that IVM can induce oxidative double-stranded damage in HeLa cells, indicating that IVM has potential genotoxicity to human health. In addition, we observed the formation of LC3-B in HeLa cells, the accumulation of Beclin1, the degradation of p62 and the activation of the AMPK/mTOR signal transduction pathway. This suggests that IVM confers cytotoxicity through autophagy mediated by the AMPK/mTOR signaling pathway. We conclude that IVM produces genotoxicity and cytotoxicity by inducing DNA damage and AMPK/mTOR-mediated autophagy, thereby posing a potential risk to human health.


Assuntos
Inseticidas/toxicidade , Ivermectina/toxicidade , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Antiparasitários/farmacologia , Autofagia/efeitos dos fármacos , Proteína Beclina-1/metabolismo , Dano ao DNA/efeitos dos fármacos , Células HeLa , Humanos , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo
14.
Life Sci ; 255: 117818, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32445757

RESUMO

Activation of hepatic stellate cells (HSCs) is a central event in the pathogenesis of liver fibrosis and is characterized by the disappearance of lipid droplets. Although the exogenous supplementation of lipid droplet content can effectively reverse the activation of HSCs, the underlying molecular mechanisms are largely unknown. In our current study, we sought to investigate the role of lncRNA-H19 in the process of lipid droplets disappearance and to further examine the underlying molecular mechanisms. We found that the lncRNA-H19 level was increased in CCl4-induced fibrotic liver, which activated HSCs. Further research showed that hypoxia inducible factor-1α (HIF-1α) significantly increased lncRNA-H19 expression by binding to the lncRNA-H19 promoter at two hypoxia response element (HRE) sites located at 492-499 and 515-522 bp. Importantly, lncRNA-H19 knockdown markedly inhibited HSC activation and alleviated liver fibrosis, indicating that lncRNA-H19 may be a potential target for anti-fibrosis therapeutic approaches. Moreover, lncRNA-H19 knockdown could reverse the lipid droplet phenotype of activated HSCs, inhibiting the phosphorylated AMPKα-mediated lipid oxidation signaling pathway. The AMPK agonist AICAR promoted AMPKα phosphorylation and abrogated lipid droplets restoration in HSCs transfected with the lncRNA-H19 knockdown plasmid. Experimental molecular analysis showed that lncRNA-H19 triggered AMPKα to interact with LKB1 and resulted in AMPKα phosphorylation, which accelerating lipid droplets degradation and lipid oxidation. Taken together, our results highlighted the role of lncRNA-H19 in the metabolism of lipid droplets in HSCs, and revealed a new molecular target for alleviating liver fibrosis.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Células Estreladas do Fígado/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Cirrose Hepática/patologia , RNA Longo não Codificante/genética , Animais , Linhagem Celular , Técnicas de Silenciamento de Genes , Humanos , Gotículas Lipídicas/metabolismo , Cirrose Hepática/genética , Masculino , Camundongos , Camundongos Endogâmicos ICR , Elementos de Resposta/genética
15.
Life Sci ; 254: 117793, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32416164

RESUMO

AIMS: Oxygen and glucose deprivation and reperfusion (OGD/R) injury contributes to the pathophysiology after ischemic stroke, which needs to urgently develop treatment strategies. Previous studies have demonstrated that autophagy in reperfusion period exerted adverse effects on the cerebral ischemic injury. Ginsenoside monomer compound K (CK) is the main intestinal metabolite of ginseng that exerts the pharmacological activities and has a protective effect against cerebral OGD/R injury. However, the specific molecular mechanism of CK protects against OGD/R injury in neurons is still unclear. MATERIALS AND METHODS: In this study, cell viability, reactive oxygen species (ROS) generation, Ca2+ overload, mitochondrial membrane potential depolarization, autophagy and apoptosis were investigated in OGD/R-induced neuronal cells injury after pretreatment with CK and in combination with BML-275 or rapamycin. KEY FINDINGS: Our study found that pretreatment with CK protected neurons against OGD/R injury by increasing cell viability and decreasing the ROS generation, mitochondrial damage, and Ca2+ overload. Moreover, CK cut down autophagy-mediated apoptosis via promoting the process of forming autophagosomes into phagocytic precursors. Furthermore, our study clarified the neuroprotective of CK against OGD/R-induced neural autophagy and apoptosis through the regulation of the AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) pathway. SIGNIFICANCE: Taken together, our study provides credible experimental evidence and explains the potential molecular mechanism of CK as one of the main bioactive ingredients of ginseng for the treatment of cerebral ischemia/reperfusion injury.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Morte Celular Autofágica/efeitos dos fármacos , Ginsenosídeos/farmacologia , Glucose/deficiência , Hipóxia/metabolismo , Traumatismo por Reperfusão/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Apoptose/efeitos dos fármacos , Autofagossomos/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Hipóxia/complicações , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Neurônios/metabolismo , Ratos , Traumatismo por Reperfusão/complicações , Transdução de Sinais/efeitos dos fármacos
16.
Life Sci ; 254: 117785, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32416167

RESUMO

As the most important bioactive substance in Garcinia cambogia, (-)-hydroxycitric acid (HCA) is widely used in food additives to regulate obesity and diabetes in animals or humans, while the mechanism is poorly understood. The purpose of this study was to elucidate the regulatory effect and mechanism of (-)-HCA in regulating glucose and lipid metabolism in chicken primary hepatocytes. The results showed that (-)-HCA obviously decreased triglyceride content through inhibiting the fatty acid synthase protein level, and enhancing the protein level of phosphorylated acetyl CoA carboxylase, enoyl coenzyme A hydratase short chain 1 and carnitine palmitoyltransferase 1A in hepatocytes. Moreover, (-)-HCA markedly enhanced the protein level of phosphofructokinase-1, pyruvate dehydrogenase, succinate dehydrogenase A and complex IV, and which led to the enhancing of glucose uptake and catabolism in hepatocytes. Importantly, the regulation of (-)-HCA on these key factors associated with lipid and glucose metabolism in hepatocytes was mainly achieved through activation of AMP-activated protein kinase/peroxisome proliferator-activated receptor gamma coactivator 1α-nuclear respiratory factor 1 signaling pathway. These results convincingly demonstrated the mechanism of (-)-HCA's regulating on glucose and lipid metabolism, and provided a strategy in prevention of diseases associated with glycolipid metabolic abnormalities in animals, even in humans.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Citratos/farmacologia , Metabolismo Energético/fisiologia , Hepatócitos/metabolismo , Fator 1 Relacionado a NF-E2/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Acetil-CoA Carboxilase/metabolismo , Animais , Carnitina O-Palmitoiltransferase/metabolismo , Galinhas , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Enoil-CoA Hidratase/metabolismo , Glucose/metabolismo , Fosfofrutoquinase-1/metabolismo , Fosforilação/efeitos dos fármacos , Cultura Primária de Células , Piruvato Desidrogenase (Lipoamida)/metabolismo , Transdução de Sinais/fisiologia , Succinato Desidrogenase/metabolismo , Triglicerídeos/metabolismo
17.
Life Sci ; 253: 117750, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32380078

RESUMO

AIM: Osteoarthritis (OA) is the main cause of disability and joint replacement surgery in the elderly. As a crucial cell survival mechanism, autophagy has been reported to decrease in OA. PHF23 is a new autophagy inhibitor which was first reported by us previously. This study aimed to explore the anti-autophagic mechanism of PHF23 to make it a possible therapeutic target of OA. MAIN METHOD: Lentiviral vectors specific to PHF23 were used on chondrocytes (C28/I2) to establish PHF23 overexpressed or knockdown stable cell strains. Interleukin (IL)-1ß (10 ng/mL) and chloroquine (CQ, 25 uM) were used as an inducer of OA and inhibitor of lysosome, respectively. Autophagy was evaluated by autophagosome formation using transmission electron microscopy (TEM) and western blot analysis of P62 and LC3B on different groups of cells. Effects of PHF23 on OA were evaluated by collagen II immunofluorescent staining and western blot analysis of OA-associated proteins MMP13 and ADAMTS5. Effects of PHF23 on AMPK and mTOR/S6K pathways and mitophagy were determined by western blot analysis. KEY FINDINGS: Knockdown of PHF23 enhanced IL-1ß-induced autophagy, while overexpression of PHF23 exerted the opposite effect. Knockdown of PHF23 protected chondrocytes against IL-1ß-induced OA by decreasing the levels of OA-associated proteins and increasing expression of Collagen II. Knockdown of PHF23 also increased mitophagy level and altered the phosphorylation levels of AMPK, mTOR, and S6K. SIGNIFICANCE: PHF23 downregulates autophagy, mitophagy in IL-1ß-induced OA-like chondrocytes and alters the activities of AMPK and mTOR/S6K, which suggests that PHF23 may be a possible therapeutic target for OA.


Assuntos
Autofagia/genética , Condrócitos/patologia , Proteínas de Homeodomínio/genética , Osteoartrite/patologia , Proteínas Quinases Ativadas por AMP/metabolismo , Sobrevivência Celular/genética , Células Cultivadas , Colágeno Tipo II/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Interleucina-1beta/administração & dosagem , Lisossomos/metabolismo , Osteoartrite/genética , Proteínas Quinases S6 Ribossômicas/metabolismo , Serina-Treonina Quinases TOR/metabolismo
18.
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
19.
Chem Biol Interact ; 325: 109126, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32430275

RESUMO

Alzheimer's disease (AD) is a common neurodegenerative disease, and its pathogenesis is closely related to ß-amyloid (Aß) peptide. The deposition of Aß in the brain due to impaired Aß clearance is considered as an important cause of AD. The decrease in Aß clearance is closely related to the autophagy dysfunction in brains of AD patients. It is feasible to treat AD by increasing the autophagy level of cells such as microglia and neurons to accelerate Aß clearance. In this article we explored the ability of graphene oxide (GO) to clear Aß through activating autophagy. Our work demonstrated that GO could inhibit the mTOR signaling pathway by activating AMPK to induce the autophagy of microglial and neurons. As expected, with the improvement of autophagy ability of microglia, GO promoted microglia-mediated Aß phagocytosis. Under the conditions of co-culture of microglia and neurons, GO induced the autophagy of microglia and neurons, especially the autophagy of microglia, thereby promoting the clearance of Aß, and ultimately achieved the effect of protecting neurons. Moreover, GO was not only non-cytotoxic to microglia and neurons but also able to reduce the toxicity of Aß to neurons through its clearance. These results have shown the potential of GO in treating Alzheimer's disease.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Autofagia/efeitos dos fármacos , Grafite/farmacologia , Microglia/citologia , Microglia/efeitos dos fármacos , Neurônios/citologia , Neurônios/efeitos dos fármacos , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Linhagem Celular Tumoral , Ativação Enzimática/efeitos dos fármacos , Humanos , Camundongos , Microglia/metabolismo , Neurônios/metabolismo , Fagocitose/efeitos dos fármacos
20.
Biochim Biophys Acta Rev Cancer ; 1874(1): 188379, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32439311

RESUMO

Breast cancer is the most ubiquitous type of neoplasms among women worldwide. Molecular aberrations associated with breast development and progressions have been extensively investigated in recent years. An AMP-activated kinase (AMPK) initially identified as a cellular energy sensor that plays a crucial role in cellular energy homeostasis. Intensive research over the last decade about the molecular mechanisms of AMPK has demonstrated that AMPK mediated diverse biological functions are achieved through phosphorylation and regulation of multiple downstream signaling molecules in normal tissue. Downregulation of AMPK activity or decreased level involved in the promotion of breast tumorigenesis, and thus activation of AMPK found to oppose tumor progression. In this review, we epitomize the recent advances in exploring the tumor suppressor function of AMPK pathways. Besides, we discuss the developments in the area of AMPK activator and its molecular mechanisms for breast cancer treatment.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Ativadores de Enzimas/uso terapêutico , Animais , Antineoplásicos/farmacologia , Aspirina/farmacologia , Aspirina/uso terapêutico , Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Neoplasias da Mama/patologia , Carcinogênese/efeitos dos fármacos , Carcinogênese/patologia , Linhagem Celular Tumoral , Ensaios Clínicos como Assunto , Modelos Animais de Doenças , Progressão da Doença , Ativadores de Enzimas/farmacologia , Feminino , Humanos , Metformina/farmacologia , Metformina/uso terapêutico , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Sorafenibe/farmacologia , Sorafenibe/uso terapêutico , Resultado do Tratamento
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