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Aim To investigate the effect of echinatin on the non-alcoholic fatty liver disease model of free fatty acids ( FFA) -induced HepG2 cells and its mechanism. Methods The experimental groups were divided into control group, FFA model group and echinatin group (0.3 , 1, 3 μmol • L
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OBJECTIVE To investigate the effects of Angelica sinensis polysaccharide on the apoptosis of cardiomyocytes in diabetic KK-Ay mice. METHODS KK-Ay mice were randomly divided into model group， metformin group （200 mg/kg） and A. sinensis polysaccharide high-dose， medium-dose and low-dose groups （400， 200 and 100 mg/kg）； C57BL/6J mice were included in blank group， with 8 mice in each group. Each group was given relevant medicine intragastrically or normal saline， once a day， for consecutive 4 weeks. After the final administration， the levels of fasting glucose， total cholesterol （TC）， low-density lipoprotein cholesterol （LDL-C） and insulin （INS） were detected； the protein expressions of B-cell lymphoma 2 （Bcl-2）， cleaved- caspase-3， apoptosis signal-regulated kinase 1 （ASK1）， phosphorylated c-Jun N-terminal kinase （p-JNK）， phosphorylated inositol- requiring enzyme 1α （p-IRE1α） in myocardium， and apoptosis in cardiomyocytes were also detected. RESULTS Compared with model group， the fasting glucose， TC and LDL-C content， apoptotic rate of cardiomyocyte， protein expressions of p-JNK and p- IRE1α， ASK1， cleaved-caspase-3 were significantly lower in the metformin group and A. sinensis polysaccharide medium-dose， high-dose groups； INS level and relative expression of Bcl-2 protein were significantly increased （P＜0.05 or P＜0.01）. CONCLUSIONS A. sinensis polysaccharide can improve the levels of blood glucose and blood lipid and inhibit cardiomyocyte apoptosis in diabetic KK-Ay mice， and the mechanism may be related to the inhibition of IRE1/ASK1/JNK signaling pathway.
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Aim To investigate the molecular mechanism of the protection of vascular smooth muscle cells by the regulation of endoplasmic reticulum stress and autophagy by Fufang Danshen dripping pills.Methods Fifty patients with atherosclerosis were randomly divided into two groups; one group received normal treatment,while the other group was added Fufang Danshen dripping pills,and the clinical efficacy was observed.Vascular smooth muscle cells were divided into control,ox LDL model,Fufang Danshen dripping pill group,Fufang Danshen dripping pill+endoplasmic reticulum stress inhibitor group,and Fufang Danshen dripping pill+endoplasmic reticulum stress inducer group.Proliferation was detected,and vasodilator function factors and oxidative stress were measured in each group,ER stress marker proteins,autophagy marker proteins and apoptosis related protein expression were detected,and activation of the IRE1-TRAF2-ASK1-JNK signaling pathway was detected.Results Compared with control group,various indicators of cells in ox-LDL model group showed that they were under ER stress,high oxidative stress,high autophagy status,and the IRE1-TRAF2-ASK1-JNK pathway was found to be over activated.However,compared with ox LDL model group,the above indicators in Fufang Danshen dripping pill group and Fufang Danshen dripping pill+endoplasmic reticulum stress inhibitor group were significantly better,the IRE1-TRAF2-ASK1-JNK pathway was over activated,and the endoplasmic reticulum stress inhibitor was more obvious,and Fufang Danshen dripping pill+endoplasmic reticulum stress inducer group significantly reversed the improved effects of Fufang Danshen dripping pills.Conclusions Fufang Danshen dripping pills protect vascular smooth muscle cells by inhibiting excessive activation of the IRE1-TRAF2-ASK1-JNK pathway,decreasing endoplasmic reticulum stress,maintaining proper autophagy,and inhibiting abnormal cell proliferation and apoptosis.
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@#Non-alcoholic steatohepatitis(NASH)is the most common chronic liver disease. However, the treatment of NASH remains challenging. Apoptosis signal regulating kinases-1(ASK-1)is a member of mitogen-activated protein kinase kinase kinases(MAPKKKs). When the body is stimulated by reactive oxygen species, endoplasmic reticulum stress, calcium influx and extracellular inflammatory signals, c-Jun amino terminal kinases(JNK)and p38 MAPK wiube activated, which then promotes cell proliferation, differentiation, apoptosis and production of inflammatory factors, and causes NASH, fibrosis and other diseases. Therefore, ASK-1 inhibitors can be used to treat NASH. This paper reviews the current treatment methods of NASH, the structure and mechanism of ASK-1, and the research progress of ASK-1 inhibitors in the treatment of NASH in recent years, which aims to explore the guiding significance for the design and development of ASK-1 inhibitors.
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Objective To study the effect of formononetin on the expression of ASK1 and JNK on the protein level in rat after unilateral ureteral obstruction (UUO). Methods Rats were then randomly divided into control group, model group, the enalapril group, and the high, medium, and low dose groups of formononetin (100, 50, and 25 mg/kg). Renal interstitial fibrosis (RIF) rats model was established by unilateral ureteral obstruction except the control group. The rats were sacrificed 14 d after surgery, and blood samples were collected to detect serum creatinine (Scr) and blood urea nitrogen (BUN) levels. HE staining was used to observe renal pathologic change and determine renal tubular damage index. The area percentage of RIF was detected by Masson staining. Expressions of ASK1 and JNK protein in kidney were determined by Western blotting. Tubular epithelial cell apoptosis was detected by TUNEL assay. Results Serum Scr, BUN level, tubulointerstitial injury index, RIF, the expressions of ASK1 and JNK protein, and apoptotic index were significantly decreased in the treatment groups when compared with the model group (P < 0.05, 0.01). The high dose group of formononetin was more effective than enalapril group. Conclusion Formononetin inhibited the expressions of ASK1 and JNK protein in UUO rats model. Ultimately renal tubular epithelial cell apoptosis was suppressed and the progression of obstructive nephropathy pathologic process was retarded.
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Objective To investigate the treatment effect of ginsenoside compound K (CK) on glucose and lipid metabolism in diabetic mellitus mice and the potential molecular mechanism.Methods A total of 36 mice were randomly divided into normal group,diabetic mellitus group,CK treatment groups (100 or 200 mg/kg body weight),dimethyldiguanide group and p38MAPK pathway agonist P79350 group,with 6 mice in each group.Diabetic mice were established by intraperitoneal injection of streptozotocin combined with high-fat diet,and CK with different doses was administrated by gastric lavage for consecutive 8 weeks.The levels of fasting blood-glucose,triglyceride (TG),total cholesterol (TC),high-density lipoprotein (HDL C),fasting serum insulin were measured,and the insulin sensitive index (ISI) was calculated in different treatment groups.Glucose tolerance was detected by oral glucose tolerance test.The protein levels of ASK1,p-ASK1 and p38,p-p38,was detected by Western blot.The mRNA expression of apoptosis signal regulating kinase-1 (ASK1) was detected by real-time quantitative PCR.Results The fasting blood-glucose,TG,TC,HDL C,fasting serum insulin and ISI were (28.31 ± 3.40),(1.90 ± 0.28),(5.00 ± 0.72),(0.50 ± 0.08),(9.01 ± 1.70) mmol/L and-6.42 ± 0.76 in diabetic mice,respectively.The corresponding values were (12.02± 1.81),(0.97 ±0.09),(2.90 ±0.49),(0.91 ±0.08),(15.12 ± 1.93)mmol/L and-4.33 ± 0.46 in 200 mg/kg CK treatment diabetic mice,and were (12.87 ± 2.61),(1.09 ± 0.11),(3.08 ± 0.27),(0.87 ±0.08),(14.97 ± 1.27) mmol/L and-4.42 ± 0.35 in dimethyldiguanide group.All of the fasting blood-glucose,TG and TC in CK treatment groups were significantly lower than those of diabetic mellitus group (P ＜0.05 or ＜0.01),but the fasting serum insulin and ISI in CK treatment groups were significantly higher than that of diabetic mellitus group (P ＜ 0.05 or ＜ 0.01).There were no significant difference between 200 mg/kg CK treatment group and dimethyldiguanide group.The mRNA levels of ASK1 in normal group,diabetic mellitus group and 200 mg/kg CK treatment group were 1.00 ± 0.07,2.52 ± 0.14 and 1.25 ± 0.08,respectively.The mRNA levels of ASK1 in diabetic mellitus group and 200 mg/kg CK treatment group were significantly up-regulated than that of normal group (P＜0.01),but there was no significant difference between 200 mg/kg CK treatment group and diabetic mellitus group in the mRNA levels of ASK1.There was no significant difference in the protein expression levels of ASK1 and p38 among normal group,diabetic mellitus group and 200 mg/kg CK treatment group,but the protein expression levels of p-ASK1 and p-p38 were significant higher in diabetic mellitus group than that in normal group (P＜0.05 or ＜0.01),and were significant lower in 200 mg/kg CK treatment group than that in diabetic mellitus group (P ＜ 0.05 or ＜ 0.01),and were no significant difference between 200 mg/kg CK treatment group and normal group.Conclusions Ginsenoside CK effectively attenuates diabetic mellitus in mouse model,possibly by inhibiting the phosphorylation of ASK1-p38MAPK signaling pathway.
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BACKGROUND/OBJECTIVES: Resveratrol, a natural polyphenol, has multiple functions in cellular responses including apoptosis, survival, and differentiation. It also participates in the regulation of inflammatory response and oxidative stress. MicroRNA-Let-7A (miR-Let7A), known as a tumor suppressor miRNA, was recently reported to play a crucial role in both inflammation and apoptosis. Therefore, we examined involvement of miR-Let7A in the modulation of inflammation and cell survival/apoptosis regulated by resveratrol. MATERIALS/METHODS: mRNA expression of pro-/anti-inflammatory cytokines and sirtuin 1 (SIRT1), and protein expression of apoptosis signal-regulating kinase 1 (ASK1), p-ASK1, and caspase-3 and cleaved caspase-3 were measured, and cell viability and Hoechst/PI staining for apoptosis were observed in Lipopolysaccharide (LPS)-stimulated human THP-1 macrophages with the treatment of resveratrol and/or miR-Let7A overexpression. RESULTS: Pre-treatment with resveratrol (25-200 µM) resulted in significant recovery of the reduced cell viabilities under LPS-induced inflammatory condition and in markedly increased expression of miR-Let7A in non-stimulated or LPS-stimulated cells. Increased mRNA levels of tumor necrosis factor-α and interleukin (IL)-6 induced by LPS were significantly attenuated, and decreased levels of IL-10 and brain-derived neurotrophic factor were significantly restored by resveratrol and miR-Let7A overexpression, respectively, or in combination. Decreased expression of IL-4 mRNA by LPS stimulation was also significantly increased by miR-Let7A overexpression co-treated with resveratrol. In addition, decreased SIRT1 mRNA levels, and increased p-ASK1 levels and PI-positive cells by LPS stimulation were significantly restored by resveratrol and miR-Let7A overexpression, respectively, or in combination. CONCLUSIONS: miR-Let7A may be involved in the inflammatory response and cell survival/apoptosis modulated by resveratrol in human THP-1 macrophages.
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Humans , Apoptosis , Brain-Derived Neurotrophic Factor , Caspase 3 , Cell Survival , Cytokines , Inflammation , Interleukin-10 , Interleukin-4 , Interleukins , Macrophages , MAP Kinase Kinase Kinase 5 , MicroRNAs , Necrosis , Oxidative Stress , RNA, Messenger , Sirtuin 1ABSTRACT
Neural stem cells (NSCs) have been suggested as a groundbreaking solution for stroke patients because they have the potential for self-renewal and differentiation into neurons. The differentiation of NSCs into neurons is integral for increasing the therapeutic efficiency of NSCs during inflammation. Apoptosis signal-regulating kinase 1 (ASK1) is preferentially activated by oxidative stress and inflammation, which is the fundamental pathology of brain damage in stroke. ASK1 may be involved in the early inflammation response after stroke and may be related to the differentiation of NSCs because of the relationship between ASK1 and the p38 mitogen-activated protein kinase pathway. Therefore, we investigated whether ASK1 is linked to the differentiation of NSCs under the context of inflammation. On the basis of the results of a microarray analysis, we performed the following experiments: western blot analysis to confirm ASK1, DCX, MAP2, phospho-p38 expression; fluorescence-activated cell sorting assay to estimate cell death; and immunocytochemistry to visualize and confirm the differentiation of cells in brain tissue. Neurosphere size and cell survival were highly maintained in ASK1-suppressed, lipopolysaccharide (LPS)-treated brains compared with only LPS-treated brains. The number of positive cells for MAP2, a neuronal marker, was lower in the ASK1-suppressed group than in the control group. According to our microarray data, phospho-p38 expression was inversely linked to ASK1 suppression, and our immunohistochemistry data showed that slight upregulation of ASK1 by LPS promoted the differentiation of endogenous, neuronal stem cells into neurons, but highly increased ASK1 levels after cerebral ischemic damage led to high levels of cell death. We conclude that ASK1 is regulated in response to the early inflammation phase and regulates the differentiation of NSCs after inflammatory-inducing events, such as ischemic stroke.
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Animals , Male , Mice , Cell Death , Infarction, Middle Cerebral Artery/metabolism , Lipopolysaccharides/pharmacology , MAP Kinase Kinase Kinase 5/genetics , Mice, Inbred C57BL , Microtubule-Associated Proteins/genetics , Neural Stem Cells/cytology , Neurogenesis , Neuropeptides/genetics , p38 Mitogen-Activated Protein Kinases/geneticsABSTRACT
Epstein-Barr virus (EBV) latent infection transforms B lymphocytes into proliferating lymphoblastoid cell lines (LCLs). EBV latent infection membrane protein 1 (LMP1) is required for EBV-mediated B lymphocyte transformation, and LMP1-induced NF-kappaB activation is essential for LCL survival. Previously, it was reported that the level of reactive oxygen species (ROS) and the expression of apoptosis signal-regulating kinase 1 (ASK1) are elevated in EBV-positive Burkitt's lymphoma (BL) cells, the potential role of ASK1 in LMP1-induced NF-kappaB activation was thus investigated in this study. In EBV-positive BL cells, ASK1 was highly expressed and activated. In addition, TRAF6-ASK1 interaction was significantly increased in EBV-positive BL cells. Interestingly, the expression of LMP1 alone facilitated ASK1 activation. The expression of a dominant negative ASK1 mutant (ASK1KM) strongly blocked LMP1-induced NF-kappaB activation. Furthermore, LMP1-induced NF-kappaB activation was significantly reduced in ASK1 knock out (ASK1-/-) mouse embryonic fibroblasts (MEFs). Taken together, these results demonstrate that ASK1 is activated by LMP1 and is critical for LMP1-induced NF-kappaB activation.
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Animals , Mice , B-Lymphocytes , Burkitt Lymphoma , Cell Line , Fibroblasts , Herpesvirus 4, Human , Lymphocyte Activation , MAP Kinase Kinase Kinase 5 , Membrane Proteins , NF-kappa B , Reactive Oxygen SpeciesABSTRACT
Dual-specificity tyrosine (Y)-phosphorylation-regulated protein kinase 1A (Dyrk1A) is the mammalian homologue of Drosophila melanogaster minibrain and its human gene is mapped to the Down syndrome critical region of chromosome 21. Dyrk1A phosphorylates several transcription factors, including NFAT and CREB and a number of cytosolic proteins such as APP, tau, and alpha-synuclein. Although Dyrk1A is involved in the control of cell growth and postembryonic neurogenesis, its potential role during cell death and signaling pathway is not clearly understood. In the present study, we show that Dyrk1A is activated under the condition of apoptotic cell death. In addition, Dyrk1A is coupled to JNK1 activation, and directly interacts with apoptosis signal-regulating kinase 1 (ASK1). Moreover, Dyrk1A positively regulates ASK1-mediated JNK1-signaling, and appears to directly phosphorylate ASK1. These data indicate that Dyrk1A regulates cell death through facilitating ASK1-mediated signaling events.
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Humans , alpha-Synuclein , Cell Death , Chromosomes, Human, Pair 21 , Cytosol , Down Syndrome , Drosophila melanogaster , MAP Kinase Kinase Kinase 5 , Neurogenesis , Protein Kinases , Proteins , Signal Transduction , Transcription Factors , TyrosineABSTRACT
Apoptosis signal-regulating kinase 1 (ASK1), a mitogen- activated protein kinase kinase kinase, plays pivotal roles in stress responses. In addition, ASK1 has emerged as a key regulator of immune responses elicited by pathogen-associated molecular patterns (PAMPs) and endogenous danger signals. Recent studies have demonstrated that reactive oxygen species (ROS)-dependent activation of ASK1 is required for LPS-stimulated cytokine production as well as extracellular ATP-induced apoptosis in immune cells. The mechanism of ROS-dependent regulation of ASK1 activity by thioredoxin and TRAFs has been well characterized. In this review, we focus on the molecular details of the activation of ASK1 and its involvement in innate immunity.
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Apoptosis , Immunity, Innate , MAP Kinase Kinase Kinase 5 , Oxygen , Phosphotransferases , Protein Kinases , Reactive Oxygen Species , ThioredoxinsABSTRACT
Apoptosis signal-regulating kinase 1 (ASK1), a mitogen- activated protein kinase kinase kinase, plays pivotal roles in stress responses. In addition, ASK1 has emerged as a key regulator of immune responses elicited by pathogen-associated molecular patterns (PAMPs) and endogenous danger signals. Recent studies have demonstrated that reactive oxygen species (ROS)-dependent activation of ASK1 is required for LPS-stimulated cytokine production as well as extracellular ATP-induced apoptosis in immune cells. The mechanism of ROS-dependent regulation of ASK1 activity by thioredoxin and TRAFs has been well characterized. In this review, we focus on the molecular details of the activation of ASK1 and its involvement in innate immunity.
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Apoptosis , Immunity, Innate , MAP Kinase Kinase Kinase 5 , Oxygen , Phosphotransferases , Protein Kinases , Reactive Oxygen Species , ThioredoxinsABSTRACT
Objective:To determine the effects of Valsartan on cardiomyocyte apoptosis and apoptosis signal-regulating kinase 1 (ASK1)-dependent signal pathway in cardiac pressure-overload hypertrophy.Methods:The hypertensive model was established by abdominal aortic constriction.24 wistar rats were randomized into three groups,banding group,banding and Valsartan admin- istration group,sham-operated group.Six weeks later,cardiomyocyte apoptosis was measured by TUNEL,ASKI protein expres- sion was measured by western blot and immunohistochemistry.Results:The left ventricular mass index,apoptosis index and ASKI protein content all significantly decreased in Valsartan group,as compared with banding group(P