ABSTRACT
Antidepressant fluoxetine can affect cerebral glucose metabolism in clinic, but the underlying molecular mechanism remains poorly understood. Here, we examined the effect of fluoxetine on brain regional glucose metabolism in a rat model of depression induced by repeated corticosterone injection, and explored the molecular mechanism. Fluoxetine was found to recover the decrease of 18F-fluorodeoxyglucose (18F-FDG) signal in prefrontal cortex (PFC), and increased 2-[N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-D-glucose (2-NBDG, a fluorescent glucose analog) uptake in an astrocyte-specific manner in ex vivo cultured PFC slices from corticosterone-induced depressive rats, which were consistent with its improvement of animal depressive behaviors. Furthermore, fluoxetine restricted nuclear translocation of glucocorticoid receptor (GR) to suppress the transcription of thioredoxin interacting protein (TXNIP). Subsequently, it promoted glucose transporter 1 (GLUT1)-mediated glucose uptake and glycolysis of PFC astrocytes through suppressing TXNIP expression under corticosterone-induced depressive state. More importantly, fluoxetine could improve glucose metabolism of corticosterone-stimulated astrocytes via TXNIP-GLUT1 pathway. These results demonstrated that fluoxetine increased astrocytic glucose uptake and glycolysis in corticosterone-induced depression via restricting GR-TXNIP-GLUT1 pathway. The modulation of astrocytic glucose metabolism by fluoxetine was suggested as a novel mechanism of its antidepressant action.
ABSTRACT
High fructose has been reported to drive glomerular podocyte oxidative stress and then induce podocyte foot process effacement in vivo, which could be partly regarded as podocyte hypermotility in vitro. Atractylodin possesses anti-oxidative effect. The aim of this study was to explore whether atractylodin prevented against fructose-induced podocyte hypermotility via anti-oxidative property. In fructose-exposed conditionally immortalized human podocytes, we found that atractylodin inhibited podocyte hypermotility, and up-regulated slit diaphragm proteins podocin and nephrin, and cytoskeleton protein CD2-associated protein (CD2AP), α-Actinin-4 and synaptopodin expression, which were consistent with its anti-oxidative activity evidenced by up-regulation of catalase (CAT) and superoxide dismutase (SOD) 1 expression, and reduction of reactive oxygen species (ROS) production. Atractylodin also significantly suppressed expression of transient receptor potential channels 6 (TRPC6) and phosphorylated Ca2+/calmodulin-dependent protein kinase IV (CaMK4) in cultured podocytes with fructose exposure. Additionally, in fructose-exposed podocytes, CaMK4 siRNA up-regulated synaptopodin and reduced podocyte hypermotility, whereas, silencing of TRPC6 by siRNA decreased p-CaMK4 expression, inhibited podocyte hypermotility, showing TRPC6/p-CaMK4 signaling activation in podocyte hypermotility under fructose condition. Just like atractylodin, antioxidant N-acetyl-L-cysteine (NAC) could inhibit TRPC6/p-CaMK4 signaling activation to reduce fructose-induced podocytes hypermotility. These results first demonstrated that the anti-oxidative property of atractylodin may contribute to the suppression of podocyte hypermotility via inhibiting TRPC6/p-CaMK4 signaling and restoring synaptopodin expression abnormality.
Subject(s)
Antioxidants/pharmacology , Fructose/adverse effects , Furans/pharmacology , Podocytes/drug effects , Sweetening Agents/adverse effects , Calcium-Calmodulin-Dependent Protein Kinase Type 4/antagonists & inhibitors , Calcium-Calmodulin-Dependent Protein Kinase Type 4/metabolism , Cell Line , Cell Movement/drug effects , Down-Regulation/drug effects , Humans , Microfilament Proteins/metabolism , Oxidative Stress/drug effects , Phosphorylation , Podocytes/physiology , Proteolysis/drug effects , Signal Transduction/drug effects , TRPC6 Cation Channel/antagonists & inhibitors , TRPC6 Cation Channel/metabolismABSTRACT
BACKGROUND: Atractylodis rhizoma, an aromatic herb for resolving dampness, is used to treat Kidney-related edema in traditional Chinese medicine for thousands years. This herb possesses antioxidant effect. However, it is not yet clear how Atractylodis rhizoma prevents glomerular injury through its anti-oxidation. PURPOSE: Based the analysis of Atractylodis rhizoma water extract (ARE) components and network pharmacology, this study was to explore whether ARE prevented glomerular injury via its anti-oxidation to inhibit oxidative stress-driven transient receptor potential channel 6 (TRPC6) and its downstream molecule calcium/calmodulin-dependent protein kinase IV (CaMK4) signaling. METHODS: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to analyze ARE components. Network pharmacology analysis was preliminarily performed. Male Sprague-Dawley rats were given 10% fructose drinking water (100 mL/d) for 16 weeks. ARE at 720 and 1090 mg/kg was orally administered to rats for the last 8 weeks. Hydrogen peroxide (H2O2) and malondialdehyde (MDA) level, and superoxide dismutase (SOD) activity in rat kidney cortex were detected, respectively. In rat glomeruli, redox-related factors forkhead box O3 (FoxO3), SOD2 and catalase (CAT), podocyte slit diaphragm proteins podocin and nephrin, cytoskeleton proteins CD2-associated protein (CD2AP) and α-Actinin-4, as well as TRPC6, p-CaMK4 and synaptopodin protein levels were analyzed by Western Blotting. SOD2 and CAT mRNA levels were detected by qRT-PCR. RESULTS: 36 components were identified in ARE. Among them, network pharmacology analysis indicated that ARE might inhibit kidney oxidative stress. Accordingly, ARE up-regulated nuclear FoxO3 expression, and then increased SOD2 and CAT at mRNA and protein levels in glomeruli of fructose-fed rats. It reduced H2O2 and MDA levels, and increased SOD activity in renal cortex of fructose-fed rats. Subsequently, ARE down-regulated TRPC6 and p-CaMK4, and up-regulated synaptopodin in glomeruli of fructose-fed rats. Furthermore, ARE increased podocin and nephrin, as well as CD2AP and α-Actinin-4, being consistent with its reduction of urine albumin-to-creatinine ratio and improvement of glomerular structure injury in this animal model. CONCLUSIONS: These results suggest that ARE may prevent glomerular injury in fructose-fed rats possibly by reducing oxidative stress to inhibit TRPC6/p-CaMK4 signaling and up-regulate synaptopodin expression. Therefore, ARE may be a promising drug for treating high fructose-induced glomerular injury in clinic.
Subject(s)
Atractylodes , Calcium-Calmodulin-Dependent Protein Kinase Type 4/metabolism , Kidney Diseases/drug therapy , Plant Extracts/pharmacology , TRPC Cation Channels/metabolism , Animals , Atractylodes/chemistry , Chromatography, Liquid , Fructose/adverse effects , Hydrogen Peroxide/metabolism , Kidney/drug effects , Kidney Diseases/chemically induced , Male , Oxidation-Reduction , Oxidative Stress , Rats , Rats, Sprague-Dawley , Rhizome/chemistry , Signal Transduction , TRPC6 Cation Channel , Tandem Mass SpectrometryABSTRACT
Glomerular hypertrophy is a crucial factor of severe podocyte damage and proteinuria. Our previous study showed that high fructose induced podocyte injury. The current study aimed to explore a novel molecular mechanism underlying podocyte hypertrophy induced by high fructose. Here we demonstrated for the first time that high fructose significantly initiated the hypertrophy in rat glomeruli and differentiated human podocytes (HPCs). Consistently, it induced inflammatory response with the down-regulation of anti-inflammatory factor zinc-finger protein tristetraprolin (TTP) and the activation of interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) signaling in these animal and cell models. Subsequently, high-expression of microRNA-92a-3p (miR-92a-3p) and its target protein cyclin-dependent kinase inhibitor p57 (P57) down-regulation, representing abnormal proliferation and apoptosis, were observed in vivo and in vitro. Moreover, high fructose increased ketohexokinase-A (KHK-A) expression in rat glomeruli and differentiated HPCs. Exogenous IL-6 stimulation up-regulated IL-6/STAT3 signaling and miR-92a-3p, reduced P57 expression and promoted podocyte proliferation, apoptosis and hypertrophy in vitro. The data from anti-inflammatory agent maslinic acid treatment or TTP siRNA transfection showed that high fructose may decrease TTP to activate IL-6/STAT3 signaling in podocyte overproliferation and apoptosis, causing podocyte hypertrophy. Whereas, KHK-A siRNA transfection remarkably restored high fructose-induced TTP down-regulation, IL-6/STAT3 signaling activation, podocyte overproliferation, apoptosis and hypertrophy in differentiated HPCs. Taken together, these results suggested that high fructose possibly increased KHK-A expression to down-regulate TTP, subsequently activated IL-6/STAT3 signaling to interfere with podocyte proliferation and apoptosis by up-regulating miR-92a-3p to suppress P57 expression, causing podocyte hypertrophy. Therefore, the inactivation of IL-6/STAT3 to relieve podocyte hypertrophy mediated by inhibiting KHK-A to increase TTP may be a novel strategy for high fructose diet-associated podocyte injury and proteinuria.
Subject(s)
MicroRNAs , Podocytes , Animals , Down-Regulation , Fructokinases/genetics , Fructokinases/metabolism , Fructose/metabolism , Hypertrophy/metabolism , Interleukin-6/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , Podocytes/metabolism , Rats , STAT3 Transcription Factor/metabolism , Tristetraprolin/genetics , Tristetraprolin/metabolismABSTRACT
High fructose is considered a causative factor for oxidative stress and autophagy imbalance that cause kidney pathogenesis. Antioxidant polydatin isolated from Polygonum cuspidatum has been reported to protect against kidney injury. In this study, polydatin was found to ameliorate fructose-induced podocyte injury. It activated mammalian target of rapamycin complex 1 (mTORC1) and suppressed autophagy in glomeruli of fructose-fed rats and in fructose-exposed conditionally immortalized human podocytes (HPCs). Polydatin also enhanced nuclear factor-E2-related factor 2 (Nrf2)-dependent antioxidant capacity to suppress fructose-induced autophagy activation in vivo and in vitro, with the attenuation of fructose-induced up-regulation of cellular light chain 3 (LC3) II/I protein levels. This effect was abolished by Raptor siRNA in fructose-exposed HPCs. These results demonstrated that polydatin ameliorated fructose-induced autophagy imbalance in an mTORC1-dependent manner via improving Nrf2-dependent antioxidant capacity during podocyte injury. In conclusion, polydatin with anti-oxidation activity suppressed autophagy to protect against fructose-induced podocyte injury.
Subject(s)
Antioxidants/metabolism , Autophagy , Feeding Behavior , Glucosides/pharmacology , Homeostasis , NF-E2-Related Factor 2/metabolism , Podocytes/metabolism , Stilbenes/pharmacology , Adenosine Triphosphate/biosynthesis , Adenylate Kinase/metabolism , Animals , Autophagy/drug effects , Fructose , Homeostasis/drug effects , Humans , Male , Mechanistic Target of Rapamycin Complex 1/metabolism , Oxidative Stress/drug effects , Podocytes/drug effects , Podocytes/pathology , Proteinuria/complications , Rats, Sprague-Dawley , Signal Transduction/drug effects , p38 Mitogen-Activated Protein Kinases/metabolismABSTRACT
Magnesium as an enzymatic activator is essential for various physiological functions such as cell cycle, metabolic regulation, muscle contraction, and vasomotor tone. A growing body of evidence supports that magnesium supplementation (mainly magnesium sulfate and magnesium oxide) prevents or treats various types of disorders or diseases related to respiratory system, reproductive system, nervous system, digestive system, and cardiovascular system as well as kidney injury, diabetes and cancer. The ongoing pandemic coronavirus disease 19 (COVID-19) characterized by respiratory tract symptoms with different degrees of important organ and tissue damages has attracted global attention. Particularly, effective drugs are still lacking in the COVID-19 therapy. In this review, we find and summarize the effectiveness of magnesium supplementation on the disorders or diseases, and provide a reference to the possibility of magnesium supplementation for supportive treatment in patients with COVID-19.
Subject(s)
Coronavirus Infections/drug therapy , Dietary Supplements , Magnesium/pharmacology , Pneumonia, Viral/drug therapy , Animals , COVID-19 , Coronavirus Infections/complications , Coronavirus Infections/prevention & control , Humans , Magnesium/adverse effects , Magnesium/therapeutic use , Pandemics/prevention & control , Pneumonia, Viral/complications , Pneumonia, Viral/prevention & control , SafetyABSTRACT
High fructose intake promotes hepatic lipid accumulation. Pterostilbene, a natural analogue of resveratrol found in diet berries, exhibits a hepatoprotective property. Here, we studied the protection by pterostilbene against fructose-induced hepatic lipid accumulation and explored its possible mechanism. We observed a high expression of microRNA-34a (miR-34a, P < 0.05) and a low expression of its target, sirtuin1 (Sirt1, mRNA: P < 0.01; protein: P < 0.001), with the overactivation of downstream sterol regulatory element-binding protein-1 (SREBP-1) lipogenic pathway (nuclear SREBP-1 protein: P < 0.05; FAS and SCD1 mRNA: P < 0.01), in rat livers, as well as BRL-3A and HepG2 cells, stimulated by fructose. More interestingly, pterostilbene recovered the fructose-disturbed miR-34a expression (0.3-0.5-fold vs fructose control, P < 0.05), Sirt1 protein level (1.2- to 1.5-fold vs fructose control, P < 0.05), and SREBP-1 lipogenic pathway, resulting in significant amelioration of hepatocyte lipid accumulation in animal [hepatic triglyceride and total cholesterol (TG&TC) mg/g·wet tissue: 4.90 ± 0.19, 5.23 ± 0.16, 5.20 ± 0.29 vs fructose control 9.73 ± 1.06, P < 0.001; 3.18 ± 0.30, 3.31 ± 0.39, 3.37 ± 0.47 vs 5.67 ± 0.28, P < 0.001] and cell models (BRL-3A TG&TC mmol/g·protein: 0.123 ± 0.011 vs 0.177 ± 0.004, P < 0.001; 0.169 ± 0.011 vs 0.202 ± 0.008, P < 0.05; HepG2: 0.257 ± 0.005 vs 0.303 ± 0.016, P < 0.05; 0.143 ± 0.004 vs 0.201 ± 0.008, P < 0.001). These results provide the experimental evidence supporting the anti-lipogenic effect of pterostilbene against fructose-induced hepatic lipid accumulation via modulating the miR-34a/Sirt1/SREBP-1 pathway.
Subject(s)
Fructose/metabolism , Liver/drug effects , MicroRNAs/metabolism , Sirtuin 1/metabolism , Sterol Regulatory Element Binding Protein 1/metabolism , Stilbenes/administration & dosage , Animals , Cholesterol/metabolism , Fructose/adverse effects , Liver/metabolism , Male , MicroRNAs/genetics , Rats , Rats, Sprague-Dawley , Sirtuin 1/genetics , Sterol Regulatory Element Binding Protein 1/genetics , Triglycerides/metabolismABSTRACT
Excessive fructose consumption induces oxidative stress and myocardial fibrosis. Antioxidant compound pterostilbene has cardioprotective effect in experimental animals. This study is aimed at investigating how fructose drove fibrotic responses via oxidative stress in cardiomyocytes and explored the attenuation mechanisms of pterostilbene. We observed fructose-induced myocardial hypertrophy and fibrosis with ROS overproduction in rats. Paired-like homeodomain 2 (Pitx2c) increase, microRNA-15b (miR-15b) low expression, and p53 phosphorylation (p-p53) upregulation, as well as activation of transforming growth factor-ß1 (TGF-ß1)/drosophila mothers against DPP homolog (Smads) signaling and connective tissue growth factor (CTGF) induction, were also detected in fructose-fed rat hearts and fructose-exposed rat myocardial cell line H9c2 cells. The results from p53 siRNA or TGF-ß1 siRNA transfection showed that TGF-ß1-induced upregulation of CTGF expression and p-p53 activated TGF-ß1/Smads signaling in fructose-exposed H9c2 cells. Of note, Pitx2c negatively modulated miR-15b expression via binding to the upstream of the miR-15b genetic loci by chromatin immunoprecipitation and transfection analysis with pEX1-Pitx2c plasmid and Pitx2c siRNA, respectively. In H9c2 cells pretreated with ROS scavenger N-acetylcysteine, or transfected with miR-15b mimic and inhibitor, fructose-induced cardiac ROS overload could drive Pitx2c-mediated miR-15b low expression, then cause p-p53-activated TGF-ß1/Smads signaling and CTGF induction in myocardial fibrosis. We also found that pterostilbene significantly improved myocardial hypertrophy and fibrosis in fructose-fed rats and fructose-exposed H9c2 cells. Pterostilbene reduced cardiac ROS to block Pitx2c-mediated miR-15b low expression and p-p53-dependent TGF-ß1/Smads signaling activation and CTGF induction in high fructose-induced myocardial fibrosis. These results firstly demonstrated that the ROS-driven Pitx2c/miR-15b pathway was required for p-p53-dependent TGF-ß1/Smads signaling activation in fructose-induced myocardial fibrosis. Pterostilbene protected against high fructose-induced myocardial fibrosis through the inhibition of Pitx2c/miR-15b pathway to suppress p-p53-activated TGF-ß1/Smads signaling, warranting the consideration of Pitx2c/miR-15b pathway as a therapeutic target in myocardial fibrosis.
Subject(s)
Fibrosis/drug therapy , Fibrosis/metabolism , Fructose/toxicity , Heart Diseases/drug therapy , Heart Diseases/metabolism , Reactive Oxygen Species/metabolism , Stilbenes/therapeutic use , Animals , Male , Oxidative Stress/drug effects , Rats , Rats, Sprague-Dawley , Signal Transduction/drug effectsABSTRACT
BACKGROUND: Polygonum cuspidatum has been used in traditional Chinese medicine to treat liver disorders associated with oxidative stress, inflammation and lipid accumulation for centuries in patients. PURPOSE: The aim of this study was to examine whether P. cuspidatum extract (PCE) prevented against fructose-induced liver lipid accumulation via regulating Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. METHOD: PCE was administered orally to male Sprague-Dawley rats given 10% fructose drinking water for 6 weeks at 80 and 160â¯mg/kg once daily for 11 weeks. RESULTS: PCE significantly alleviated liver lipid accumulation in fructose-fed rats with metabolic syndrome. It also inhibited Keap1, activated Nrf2 antioxidant pathway, resulting in the suppression of oxidative stress, evidenced by reducing hydrogen peroxide (H2O2), malondialdehyde (MDA) and hydroxy radical (OHâ¢) levels, and increasing glutathione (GSH)/oxidized glutathione (GSSG) ratio as well as superoxidase dismutase (SOD) and catalase (CAT) activity in the liver of fructose-fed rats. Additionally, PCE up-regulated peroxisome proliferator activated receptor-α (PPAR-α), and down-regulated sterol regulatory element binging protein 1 (SREBP-1), fatty acid synthetase (FAS) and stearoyl-CoA desaturase-1 (SCD-1) in this animal model, being consistent with its reduction of triglyceride (TG) levels. CONCLUSION: These results demonstrate that PCE reduces oxidative stress, and prevent lipid accumulation in the liver of fructose-fed rats possibly by targeting the Keap1/Nrf2 pathway. PCE may be a promising therapeutic strategy for fructose-associated liver lipid accumulation.
Subject(s)
Fallopia japonica/chemistry , Kelch-Like ECH-Associated Protein 1/metabolism , Lipid Metabolism/drug effects , Liver/drug effects , NF-E2-Related Factor 2/metabolism , Plant Extracts/pharmacology , Animals , Antioxidants/metabolism , Fructose/adverse effects , Glutathione/metabolism , Liver/metabolism , Male , Metabolic Syndrome/drug therapy , Metabolic Syndrome/metabolism , Oxidative Stress/drug effects , Rats, Sprague-Dawley , Stearoyl-CoA Desaturase/metabolism , Sterol Regulatory Element Binding Protein 1/metabolismABSTRACT
BACKGROUND AND PURPOSE: Excessive fructose consumption is a risk factor for liver fibrosis. Pterostilbene protects against liver fibrosis. Here, we investigated the potential role and the mechanisms underlying the hepatocyte epithelial-mesenchymal transition (EMT) in fructose-induced liver fibrosis and protection by pterostilbene. EXPERIMENTAL APPROACH: Characteristic features of liver fibrosis in 10% fructose-fed rats and EMT in 5 mM fructose-exposed BRL-3A cells with or without pterostilbene and the change of miR-34a/Sirt1/p53 and transforming growth factor-ß1 (TGF-ß1)/Smads signalling were examined. MiR-34a inhibitor, miR-34a minic, or p53 siRNA were used to explore the role of miR-34a/Sirt1/p53 signalling in fructose-induced EMT and the action of pterostilbene. KEY RESULTS: Pterostilbene prevented fructose-induced liver injury with fibrosis in rats. Fructose caused hepatocyte undergoing EMT, gaining fibroblast-specific protein 1 and vimentin, and losing E-cadherin, effects attenuated by pterostilbene. Moreover, fructose induced miR-34a overexpression in hepatocytes with down-regulated Sirt1, increased p53 and ac-p53, and activated TGF-ß1/Smads signalling, whereas these disturbances were suppressed by miR-34a inhibitor. Additionally, miR-34a inhibitor and p53 siRNA prevented TGF-ß1-driven hepatocyte EMT under fructose exposure. Pterostilbene down-regulated miR-34a, up-regulated Sirt1, and suppressed p53 activation and TGF-ß1/Smads signalling in fructose-stimulated animals and cells but showed no additional effects with miR-34a inhibitor on miR-34a/Sirt1/p53 signalling in fructose-exposed hepatocytes. CONCLUSIONS AND IMPLICATIONS: These results strongly suggest that activation of miR-34a/Sirt1/p53 signalling is required for fructose-induced hepatocyte EMT mediated by TGF-ß1/Smads signalling, contributing to liver fibrosis in rats. Pterostilbene exhibits a protective effect against liver fibrosis at least partly through inhibiting miR-34a/Sirt1/p53 signalling activation.
Subject(s)
Epithelial-Mesenchymal Transition/drug effects , Hepatocytes/drug effects , Liver Cirrhosis/metabolism , Protective Agents/pharmacology , Stilbenes/pharmacology , Animals , Fructose , Hepatocytes/physiology , Liver/drug effects , Liver/metabolism , Liver/pathology , Liver Cirrhosis/pathology , Male , MicroRNAs/genetics , Rats, Sprague-Dawley , Signal Transduction/drug effects , Sirtuin 1/genetics , Smad Proteins/metabolism , Transforming Growth Factor beta1/metabolism , Tumor Suppressor Protein p53/geneticsABSTRACT
Increasing evidence has demonstrated that excessive fructose intake induces liver fibrosis. Epithelial-mesenchymal transition (EMT) driven by transforming growth factor-ß1 (TGF-ß1)/mothers against decapentaplegic homolog (Smad) signaling activation promotes the occurrence and development of liver fibrosis. Magnesium isoglycyrrhizinate is clinically used as a hepatoprotective agent to treat liver fibrosis, but its underlying molecular mechanism has not been identified. Using a rat model, we found that high fructose intake reduced microRNA (miR)-375-3p expression and activated the janus-activating kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) cascade and TGF-ß1/Smad signaling, which is consistent with the EMT and liver fibrosis. To further verify these observations, BRL-3A cells and/or primary rat hepatocytes were exposed to high fructose and/or transfected with a miR-375-3p mimic or inhibitor or treated with a JAK2 inhibitor, and we found that the low expression of miR-375-3p could induce the JAK2/STAT3 pathway to activate TGF-ß1/Smad signaling and promote the EMT. Magnesium isoglycyrrhizinate was found to ameliorate high fructose-induced EMT and liver fibrosis in rats. More importantly, magnesium isoglycyrrhizinate increased miR-375-3p expression to suppress the JAK2/STAT3 pathway and TGF-ß1/Smad signaling in these animal and cell models. This study provides evidence showing that magnesium isoglycyrrhizinate attenuates liver fibrosis associated with a high fructose diet.
Subject(s)
Liver Cirrhosis/drug therapy , MicroRNAs/metabolism , Saponins/therapeutic use , Signal Transduction/drug effects , Triterpenes/therapeutic use , Animals , Cell Line , Epithelial-Mesenchymal Transition/drug effects , Fructose , Janus Kinase 2/metabolism , Liver Cirrhosis/chemically induced , Male , Rats, Sprague-Dawley , STAT3 Transcription Factor/metabolism , Saponins/pharmacology , Smad Proteins, Receptor-Regulated/metabolism , Transforming Growth Factor beta1/metabolism , Triterpenes/pharmacologyABSTRACT
Excess fructose consumption causes high prevalence of metabolic syndrome and inflammatory liver diseases. The aim of the current study was to investigate the therapeutic effects and underlying molecular mechanisms of curcumin and allopurinol in high fructose-induced hepatic inflammation. Male Sprague-Dawley rats were supplied with standard rat chow and drinking water containing 10% (w/v) fructose for consecutive 12 weeks. Curcumin (15, 30 and 60 mg/kg) and allopurinol (5 mg/kg) were administered to rats via oral gavage daily from Week 7 to 12. For in vitro experiments, curcumin (2.5 µM) and allopurinol (100 µM) were treated to 5 mM fructose-exposed Buffalo rat liver cell line (BRL-3 A) and human hepatoblastoma cell line (HepG2), respectively. The data from these animal and hepatocyte models showed that curcumin and allopurinol ameliorated fructose-induced metabolic symptom, especially hepatic inflammation in rats. Interestingly, down-regulation of microRNA-200a (miR-200a) was screened out in livers of fructose-fed rats and then validated in fructose-exposed BRL-3 A and HepG2 cells. Fructose-induced miR-200a low-expression was identified as a negative mediator of thioredoxin interacting protein (TXNIP) by direct targeting of 3'UTR-rTXNIP, subsequently activating the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome in BRL-3 A cells. Curcumin, as well as allopurinol, notably up-regulated miR-200a expression, accordingly, down-regulated TXNIP and inhibited NLRP3 inflammasome activation in fructose-fed rat livers and fructose-exposed BRL-3 A and HepG2 cells. Taken together, this study firstly identified miR-200a as a biomarker of fructose-induced hepatic inflammation, and revealed the hepatoprotection of curcumin and allopurinol via up-regulating miR-200a-mediated TXNIP/NLRP3 inflammasome pathway.
Subject(s)
Allopurinol/pharmacology , Carrier Proteins/metabolism , Curcumin/pharmacology , MicroRNAs/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Protective Agents/pharmacology , Animals , Cell Cycle Proteins , Cell Line , Fructose , Humans , Inflammation/chemically induced , Inflammation/drug therapy , Inflammation/metabolism , Liver/drug effects , Liver/metabolism , Liver/pathology , Male , Rats, Sprague-DawleyABSTRACT
Oxidative stress is a critical factor in nonalcoholic fatty liver disease pathogenesis. MicroRNA-200a (miR-200a) is reported to target Kelch-like ECH-associated protein 1 (Keap1), which regulates nuclear factor erythroid 2-related factor 2 (Nrf2) anti-oxidant pathway. Polydatin (3,4',5-trihydroxy-stilbene-3-ß-D-glucoside), a polyphenol found in the rhizome of Polygonum cuspidatum, have anti-oxidative, anti-inflammatory and anti-hyperlipidemic effects. However, whether miR-200a controls Keap1/Nrf2 pathway in fructose-induced liver inflammation and lipid deposition and the blockade of polydatin are still not clear. Here, we detected miR-200a down-regulation, Keap1 up-regulation, Nrf2 antioxidant pathway inactivation, ROS-driven thioredoxin-interacting protein (TXNIP) over-expression, NOD-like receptor (NLR) family, pyrin domain containing 3 (NLRP3) inflammasome activation and dysregulation of peroxisome proliferator activated receptor-α (PPAR-α), carnitine palmitoyl transferase-1 (CPT-1), sterol regulatory element binging protein 1 (SREBP-1) and stearoyl-CoA desaturase-1 (SCD-1) in rat livers, BRL-3A and HepG2 cells under high fructose induction. Furthermore, the data from the treatment or transfection of miR-200a minic, Keap1 and TXNIP siRNA, Nrf2 activator and ROS inhibitor demonstrated that fructose-induced miR-200a low-expression increased Keap1 to block Nrf2 antioxidant pathway, and then enhanced ROS-driven TXNIP to activate NLRP3 inflammasome and disturb lipid metabolism-related proteins, causing inflammation and lipid deposition in BRL-3A cells. We also found that polydatin up-regulated miR-200a to inhibit Keap1 and activate Nrf2 antioxidant pathway, resulting in attenuation of these disturbances in these animal and cell models. These findings provide a novel pathological mechanism of fructose-induced redox status imbalance and suggest that the enhancement of miR-200a to control Keap1/Nrf2 pathway by polydatin is a therapeutic strategy for fructose-associated liver inflammation and lipid deposition.
Subject(s)
Anti-Inflammatory Agents/therapeutic use , Fructose/adverse effects , Glucosides/therapeutic use , Inflammation/chemically induced , Inflammation/prevention & control , Liver/drug effects , MicroRNAs/immunology , Stilbenes/therapeutic use , Animals , Antioxidants/therapeutic use , Cell Line , Drugs, Chinese Herbal/therapeutic use , Inflammation/immunology , Inflammation/pathology , Kelch-Like ECH-Associated Protein 1/immunology , Lipids/analysis , Lipids/immunology , Liver/immunology , Liver/pathology , Male , NF-E2-Related Factor 2/immunology , Oxidative Stress/drug effects , Rats, Sprague-Dawley , Signal Transduction/drug effectsABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: Banxia-houpu decoction is a famous formula in traditional Chinese medicine (TCM) with the powerful anti-depressant activity. AIM OF THE STUDY: This study aimed to investigate the effect of Banxia-houpu decoction on glucose intolerance associated with anhedonia in chronic unpredictable mild stress (CUMS) rats, then to explore its underlying pharmacological mechanisms. MATERIALS AND METHODS: After 6-week CUMS procedure, male Wistar rats were given Banxia-houpu decoction (3.29 and 6.58g/kg, intragastrically) for 6 weeks. Sucrose solution consumption test was employed to evaluate the anhedonia behavior. Oral glucose tolerance test (OGTT) was used to determine glucose tolerance. Serum levels of corticosterone, corticotropin-releasing factor (CRF), insulin and interleukin-1 beta (IL-1ß) were measured by commercial enzyme-linked immunosorbent assay kits, respectively. Furthermore, the key proteins for insulin signaling, as well as nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, were analyzed by Western blot in periphery liver and brain regions hypothalamus, hippocampus and prefrontal cortex, respectively. RESULTS: Banxia-houpu decoction significantly increased sucrose solution consumption and decreased serum corticosterone and CRF levels in CUMS rats, further demonstrating its antidepressant activity. More importantly, Banxia-houpu decoction improved glucose tolerance in OGTT in this animal model. Furthermore, it protected against CUMS-induced insulin signaling impairment in the liver, as well as hypothalamus and prefrontal cortex in rats. Although without significant effect on serum IL-1ß levels, Banxia-houpu decoction inhibited NLRP3 inflammasome activation in the liver, hypothalamus, hippocampus and prefrontal cortex of CUMS rats, respectively. CONCLUSIONS: The present study demonstrates that Banxia-houpu decoction suppresses NLRP3 inflammasome activation and improves insulin signaling impairment in both periphery liver and brain regions in CUMS rats, possibly contributing to its anti-depressive effect with glucose tolerance improvement. These results may provide the evidence that Banxia-houpu decoction is a potential antidepressant with the advantage to reduce the risk of comorbid depression with type 2 diabetes mellitus.