The family members of the mitogen-activated protein (MAP) kinases mediate a wide variety of cellular behaviors in response to extracellular stimuli. One of the four main sub-groups, the p38 group of MAP kinases, serve...The family members of the mitogen-activated protein (MAP) kinases mediate a wide variety of cellular behaviors in response to extracellular stimuli. One of the four main sub-groups, the p38 group of MAP kinases, serve as a nexus for signal transduction and play a vital role in numerous biological processes. In this review, we highlight the known characteristics and components of the p38 pathway along with the mechanism and consequences of p38 activation. We focus on the role of p38 as a signal transduction mediator and examine the evidence linking p38 to inflammation, cell cycle, cell death, development, cell differentiation, senescence and tumorigenesis in specific cell types. Upstream and downstream components of p38 are described and questions remaining to be answered are posed. Finally, we propose several directions for future research on p38.展开更多
AIM: To investigate the effects and molecular mechanisms of berberine on improving insulin resistance induced by free fatty acids (FFAs) in 3T3-L1 adipocytes. METHODS: The model of insulin resistance in 3T3-L1 adipocy...AIM: To investigate the effects and molecular mechanisms of berberine on improving insulin resistance induced by free fatty acids (FFAs) in 3T3-L1 adipocytes. METHODS: The model of insulin resistance in 3T3-L1 adipocytes was established by adding palmic acid (0.5 mmol/L) to the culture medium. Berberine treatment was performed at the same time. Glucose uptake rate was determined by the 2-deoxy-[3H]-D-glucose method. The levels of IkB kinase beta (IKKβ) Ser181 phosphorylation, insulin receptor substrate-1(IRS-1) Ser307 phosphorylation, expression of IKKβ, IRS-1, nuclear transcription factor kappaB p65 (NF-κB p65), phosphatidylinositol-3-kinase p85 (PI-3K p85) and glucose transporter 4 (GLUT4) proteins were detected by Western blotting. The distribution of NF-κB p65 proteins inside the adipocytes was observed through confocal laser scanning microscopy (CLSM). RESULTS: After the intervention of palmic acid for 24 h, the insulin-stimulated glucose transport in 3T3-L1 adipocytes was inhibited by 67%. Meanwhile, the expression of IRS-1 and PI-3K p85 protein was reduced, while the levels of IKKβ Ser181 and IRS-1 Ser307 phosphorylation, and nuclear translocation of NF-κB p65 protein were increased. However, the above indexes, which indicated the existence of insulin resistance, were reversed by berberine although the expression of GLUT4, IKKβ and total NF-κB p65 protein were not changed during this study. CONCLUSION: Insulin resistance induced by FFAs in 3T3-L1 adipocytes can be improved by berberine. Berberine reversed free-fatty-acid-induced insulin resistance in 3T3-L1 adipocytes through targeting IKKβ.展开更多
Ischemia reperfusion injury is a major obstacle in liver resection and liver transplantation surgery.Understanding the mechanisms of liver ischemia reperfusion injury(IRI) and developing strategies to counteract this ...Ischemia reperfusion injury is a major obstacle in liver resection and liver transplantation surgery.Understanding the mechanisms of liver ischemia reperfusion injury(IRI) and developing strategies to counteract this injury will therefore reduce acute complications in hepatic resection and transplantation,as well as expanding the potential pool of usable donor grafts.The initial liver injury is initiated by reactive oxygen species which cause direct cellular injury and also activate a cascade of molecular mediators leading to microvascular changes,increased apoptosis and acute inflammatory changes with increased hepatocyte necrosis.Some adaptive pathways are activated during reperfusion that reduce the reperfusion injury.IRI involves a complex interplay between neutrophils,natural killer T-cells cells,CD4+ T cell subtypes,cytokines,nitric oxide synthases,haem oxygenase-1,survival kinases such as the signal transducer and activator of transcription,Phosphatidylinositol 3-kinases/Akt and nuclear factor κβ pathways.Transgenic animals,particularly genetic knockout models,have become a powerful tool at elucidating mechanisms of liver ischaemia reperfusion injury and are complementary to pharmacological studies.Targeted disruption of the protein at the genetic level is more specific and maintained than pharmacological inhibitors or stimulants of the same protein.This article reviews the evidence from knockout models of liver IRI about the cellular and molecular mechanisms underlying liver IRI.展开更多
Objective： To explore the effects and molecular mechanisms of the combination between total Astragalus extract （TAE） and total Panax notoginseng saponins （TPNS） against cerebral ischemia- reperfusion injury. Meth...Objective： To explore the effects and molecular mechanisms of the combination between total Astragalus extract （TAE） and total Panax notoginseng saponins （TPNS） against cerebral ischemia- reperfusion injury. Methods： C57BL/6 mice were randomly divided into sham-operated group, model group, TAE （110 mg/kg） group, TPNS （115 mg/kg） group, TAE-TPNS combination group and Edaravone （4 mg/kg） group, treated for 4 days, then, cerebral ischemia-repeffusion injury was established by bilateral common carotid artery （CCA） ligation for 20 min followed by reperfusion for 1 and 24 h. Results： TPNS could increase adenosine triphosphate （ATP） level, TAE and TAE-TPNS combination increased ATP, adenosine diphosphate （ADP） contents and Na＋-K＋-ATPase activity, and the effects of TAE-TPNS combination were stronger than those of TAE or TPNS alone after reperfusion for 1 h. After reperfusion for 24 h, TAE, TPNS and TAE-TPNS combination significantly increased neurocyte survival rate and decreased the apoptosis rate as well as down-regulated the expression of phosphorylated c-June N-terminal kinasel/2 （p-JNK1/2）, cytochrome C （Cyt C）, cysteine aspartic acid-specific protease （Caspase）-9 and Caspase-3. Furthermore, the effects in TAE-TPNS combination were better than those in TAE or TPNS alone. Conclusion： The combination of TAE 110 mg/kg and TPNS 115 mg/kg could strengthen protective effects on cerebral ischemia injury, the mechanism underlying might be related to improving jointly the early energy metabolism, and relieving the delayed apoptosis via inhibiting the mitochondrial apoptosis pathway of JNK signal transduction.展开更多
The mitogen-activated protein kinases(MAPK) pathway, often known as the RAS-RAFMEK-ERK signal cascade, functions to transmit upstream signals to its downstream effectors to regulate physiological process such as cell ...The mitogen-activated protein kinases(MAPK) pathway, often known as the RAS-RAFMEK-ERK signal cascade, functions to transmit upstream signals to its downstream effectors to regulate physiological process such as cell proliferation, differentiation, survival and death. As the most frequently mutated signaling pathway in human cancer, targeting the MAPK pathway has long been considered a promising strategy for cancer therapy. Substantial efforts in the past decades have led to the clinical success of BRAF and MEK inhibitors. However, the clinical benefits of these inhibitors are compromised by the frequently occurring acquired resistance due to cancer heterogeneity and genomic instability. This review briefly introduces the key protein kinases involved in this pathway as well as their activation mechanisms. We also generalize the correlations between mutations of MAPK members and human cancers, followed by a summarization of progress made on the development of small molecule MAPK kinases inhibitors. In particular, this review highlights the potential advantages of ERK inhibitors in overcoming resistance to upstream targets and proposes that targeting ERK kinase may hold a promising prospect for cancer therapy.展开更多
Autophagy,defined as a scavenging process of protein aggregates and damaged organelles mediated by lysosomes,plays a significant role in the quality control of macromolecules and organelles.Since protein kinases are i...Autophagy,defined as a scavenging process of protein aggregates and damaged organelles mediated by lysosomes,plays a significant role in the quality control of macromolecules and organelles.Since protein kinases are integral to the autophagy process,it is critically important to understand the role of kinases in autophagic regulation.At present,intervention of autophagic processes by small-molecule modulators targeting specific kinases has becoming a reasonable and prevalent strategy for treating several varieties of human disease,especially cancer.In this review,we describe the role of some autophagy-related kinase targets and kinase-mediated phosphorylation mechanisms in autophagy regulation.We also summarize the small-molecule kinase inhibitors/activators of these targets,highlighting the opportunities of these new therapeutic agents.展开更多
Puerarin, a major isoflavonoid derived from the Chinese medical herb radix puerariae （Gegen）, has been reported to inhibit neuronal apoptosis and play an anti-inflammatory role in focal cerebral ischemia model rats....Puerarin, a major isoflavonoid derived from the Chinese medical herb radix puerariae （Gegen）, has been reported to inhibit neuronal apoptosis and play an anti-inflammatory role in focal cerebral ischemia model rats. Recent findings regarding stroke pathophysiology have recognized that anti-inflammation is an important target for the treatment of ischemic stroke. The cholinergic anti-inflammatory pathway is a highly robust neural-immune mechanism for inflammation control. This study was to investigate whether activating the cholinergic anti-inflammatory pathway can be involved in the mechanism of inhibiting the inflammatory response during puerarin-induced cerebral ischemia/reperfusion in rats. Results showed that puerarin pretreatment （intravenous injection） re- duced the ischemic infarct volume, improved neurological deficit after cerebral ischemia/reperfusion and decreased the levels of interleukin-1β, interleukin-6 and tumor necrosis factor-a in brain tissue. Pretreatment with puerarin （intravenous injection） attenuated the inflammatory response in rats, which was accompanied by janus-activated kinase 2 （JAK2） and signal transducers and activators of transcription 3 （STAT3） activation and nuclear factor kappa B （NF-KB） inhibition. These observa- tions were inhibited by the alpha7 nicotinic acetylcholine receptor （a7nAchR） antagonist a-bungarotoxin （a-BGT）. In addition, puerarin pretreatment increased the expression of a7nAchR mRNA in ischemic cerebral tissue. These data demonstrate that puerarin pretreatment strongly protects the brain against cerebral ischemia/reperfusion injury and inhibits the inflammatory re- sponse. Our results also indicated that the anti-inflammatory effect of puerarin may partly be medi- ated through the activation of the cholinergic anti-inflammatory pathway.展开更多
AIM:To investigate whether the apoptotic activities of 8-bromo-7-methoxychrysin(BrMC) involve reactive oxygen species(ROS) generation and c-Jun N-terminal kinase(JNK) activation in human hepatocellular carcinoma cells...AIM:To investigate whether the apoptotic activities of 8-bromo-7-methoxychrysin(BrMC) involve reactive oxygen species(ROS) generation and c-Jun N-terminal kinase(JNK) activation in human hepatocellular carcinoma cells(HCC).METHODS:HepG2,Bel-7402 and L-02 cell lines were cultured in vitro and the apoptotic effects of BrMC were evaluated by flow cytometry(FCM) after propidium iodide(PI) staining,caspase-3 activity using enzymelinked immunosorbent assay(ELISA),and DNA agarose gel electrophoresis.ROS production was evaluated by FCM after dichlorodihydrofluorescein diacetate(DCHFDA) probe labeling.The phosphorylation level of JNK and c-Jun protein was analyzed by Western blotting.RESULTS:FCM after PI staining showed a dose-dependent increase in the percentage of the sub-G1 cell pop-ulation(P < 0.05),reaching 39.0% ± 2.8% of HepG2 cells after 48 h of treatment with BrMC at 10 μmol/L.The potency of BrMC to HepG2 and Bel-7402(32.1% ± 2.6%) cells was found to be more effective than the lead compound,chrysin(16.2% ± 1.6% for HepG2 cells and 11.0% ± 1.3% for Bel-7402 cell) at 40 μmol/L and similar to 5-flurouracil(33.0% ± 2.1% for HepG2 cells and 29.3% ± 2.3% for Bel-7402 cells) at 10 μmol/L.BrMC had little effect on human embryo liver L-02 cells,with the percentage of sub-G1 cell population 5.4% ± 1.8%.Treatment of HepG2 cells with BrMC for 48 h also increased the levels of active caspase-3,in a concentration-dependent manner.z-DEVD-fmk,a caspase-3specific inhibitor,prevented the activation of caspase-3.Treatment with BrMC at 10 μmol/L for 48 h resulted in the formation of a DNA ladder.Treatment of cells with BrMC(10 μmol/L) increased mean fluorescence intensity of DCHF-DA in HepG2 cells from 7.2 ± 1.12 at 0 h to 79.8 ± 3.9 at 3 h and 89.7 ± 4.7 at 6 h.BrMC did not affect ROS generation in L-02 cells.BrMC treatment failed to induce cell death and caspase-3 activation in HepG2 cells pretreated with N-acetylcysteine(10 mmol/L).In addition,in HepG2 cells treated with BrMC(2.5,5.0,10.0 μmol/L) for 12 h,JNK acti展开更多
The number of patients with nonalcoholic fatty liver diseases(NAFLD) including nonalcoholic steatohepatitis(NASH), has been increasing. NASH causes cirrhosis and hepatocellular carcinoma(HCC) and is one of the most se...The number of patients with nonalcoholic fatty liver diseases(NAFLD) including nonalcoholic steatohepatitis(NASH), has been increasing. NASH causes cirrhosis and hepatocellular carcinoma(HCC) and is one of the most serious health problems in the world. The mechanism through which NASH progresses is still largely unknown. Activation of caspases, Bcl-2 family proteins, and c-Jun N-terminal kinase-induced hepatocyte apoptosis plays a role in the activation of NAFLD/NASH. Apoptotic hepatocytes stimulate immune cells and hepatic stellate cells toward the progression of fibrosis in the liver through the production of inflammasomes and cytokines. Abnormalities in glucose and lipid metabolism as well as microbiota accelerate these processes. The production of reactive oxygen species, oxidative stress, and endoplasmic reticulum stress is also involved. Cell death, including apoptosis, seems very important in the progression of NAFLD and NASH. Recently, inhibitors of apoptosis have been developed as drugs for the treatment of NASH and may prevent cirrhosis and HCC. Increased hepatocyte apoptosis may distinguish NASH from NAFLD, and the improvement of apoptosis could play a role in controlling the development of NASH. In this review, the association between apoptosis and NAFLD/NASH are discussed. This review could provide their knowledge, which plays a role in seeing the patients with NAFLD/NASH in daily clinical practice.展开更多
Background:On May 8,2018,the China National Medical Products Administration(NMPA)approved anlotinib,an orally administered anti-angiogenesis inhibitor,for the treatment of patients with advanced non-small cell lung ca...Background:On May 8,2018,the China National Medical Products Administration(NMPA)approved anlotinib,an orally administered anti-angiogenesis inhibitor,for the treatment of patients with advanced non-small cell lung can-cer(NSCLC)who have progressed after treatment with two or more lines of prior systemic chemotherapy.Main body of the abstract:China NMPA reviewed and inspected a regional double-blinded,placebo-controlled,Phase III trial comparing the overall survival(OS)of NSCLC patients between the anlotinib and placebo arms.A total of 437 patients were randomized(2:1)to receive either anlotinib(n=294)or placebo(n=143)once daily on a 2-week on and 1-week off schedule.Patients with epidermal growth factor receptor(EGFR)or activating anaplastic lymphoma kinase(ALK)genomic tumor aberrations should have disease progression on NMPA-approved therapy.Anlotinib is the first NMPA-approved drug for patients with advanced NSCLC who have progressed on at least two lines of prior systemic chemotherapies in China.The approval was based on a statistically and clinically significant improvement in median OS with anlotinib(9.46 months)compared with placebo[6.37 months;hazard ratio(HR])=0.70,95%confidence interval(CI)=0.55-0.89;two-sided log-rank P=0.002].The confirmed objective response rate(ORR)was 9.2%in the anlotinib arm and 0.7%in the placebo arm.The median duration of response(DoR)was 4.83 months,with a 95%CI of 3.31-6.97 months.The toxicity profile of anlotinib was consistent with that of known anti-angiogenesis inhibitors.Common adverse drug reactions(ADRs)in anlotinib-treated patients included hypertension(67.4%),hand-foot syndrome(43.9%),hemoptysis(14.0%),thyroid stimulating hormone(TSH)elevation(46.6%),and corrected QT interval(QTc)prolongation(26.2%).Short conclusion:Anlotinib demonstrated a clinically significant OS prolongation as a novel therapeutic option for advanced or metastatic NSCLC following at least two lines of chemotherapy.展开更多
c-Jun,the most extensively studied protein of the activator protein-1(AP-1)complex,is involved in numerous cell activities,such as proliferation,apoptosis,survival,tumorigenesis and tissue morphogenesis.Earlier studie...c-Jun,the most extensively studied protein of the activator protein-1(AP-1)complex,is involved in numerous cell activities,such as proliferation,apoptosis,survival,tumorigenesis and tissue morphogenesis.Earlier studies focused on the structure and function have led to the identification of c-Jun as a basic leucine zipper(bZIP)transcription factor that acts as homo-or heterodimer,binding to DNA and regulating gene transcription.Later on,it was shown that extracellular signals can induce post-translational modifications of c-Jun,resulting in altered transcriptional activity and target gene expression.More recent work has uncovered multiple layers of a complex regulatory scheme in which c-Jun is able to crosstalk,amplify and integrate different signals for tissue development and disease.One example of such scheme is the autocrine amplification loop,in which signal-induced AP-1 activates the c-Jun gene promoter,while increased c-Jun expression feedbacks to potentiate AP-1 activity.Another example of such scheme,based on recent characterization of gene knockout mice,is that c-Jun integrates signals of several developmental pathways,including EGFR-ERK,EGFR-RhoA-ROCK,and activin B-MAP3K1-JNK for embryonic eyelid closure.After more than two decades of extensive research,c-Jun remains at the center stage of a molecular network with mysterious functional properties,some of which are yet to be discovered.In this article,we will provide a brief historical overview of studies on c-Jun regulation and function,and use eyelid development as an example to illustrate the complexity of c-Jun crosstalking with signaling pathways.展开更多
Objective： To study the effect of salvianolic acid B （SAB） and curcumin, the extracts of Solvie Miltiorrhize and Curcume Longe, on the proliferation and activation of hepatic stellate cell （HSC）, and the extracel...Objective： To study the effect of salvianolic acid B （SAB） and curcumin, the extracts of Solvie Miltiorrhize and Curcume Longe, on the proliferation and activation of hepatic stellate cell （HSC）, and the extracellular signal regulated kinase （ERK） expression in it. Methods： Rat＇s HSC-T6 were cultured and treated by SAB or curcumin. The inhibitory effect on cell proliferation was determined by 3-（4,5-dimthyl-2- 2thiazoly）-2,5-diphenyl-2H-tetrazolium bromide （MTT） colorimetry, and the expression levels of a smooth actin （a-SMA）, collagen type Ⅰ , and ERK were determined by Western blot. Results： SAB and curcumin inhibited the proliferation and activation of rat＇s HSC-T6 in dose-dependent fashion and significantly reduced the expression level of a-SMA （ P〈0.01 ）. Curcumin significantly reduced the expression of collagen type Ⅰ （P〈0.05）. Both SAB and curcumin showed insignificant effect on the ERK expression level, but they could significantly reduce the level of phosphorylated-ERK expression, showing significant difference as compared with that in the control group （ P〈0.01 and P〈0.05 respectively）. Conclusion： SAB and curcumin could significantly inhibit the proliferation, activation of HSC, and the production of type Ⅰ collagen in HSC, the mechanism may be associated with their inhibition on ERK phosphorylation.展开更多
Marsdenia tenacissima extract(MTE, trade name: Xiao-Ai-Ping injection) is an extract of a single Chinese plant medicine. It has been used for the treatment of cancer in China for decades, especially for esophageal can...Marsdenia tenacissima extract(MTE, trade name: Xiao-Ai-Ping injection) is an extract of a single Chinese plant medicine. It has been used for the treatment of cancer in China for decades, especially for esophageal cancer and other cancers in the digestive tract. In the present study, the potential mechanism for MTE's activity in esophageal cancer was explored. The effects of MTE on the proliferation of human esophageal cancer cells(KYSE150 and Eca-109) were investigated by the MTT assay, the Brd U(bromodeoxyuridine) incorporation immunofluorescence assay, and flow cytometric analysis. MTE inhibited cell proliferation through inducing G0/G1 cell cycle arrest in KYSE150 and Eca-109. Western blot analysis was employed to determine protein levels in the MTE treated cells. Compared with the control cells, the expression levels of the cell cycle regulatory proteins cyclin D1/D2/D3, cyclin E1, CDK2/4/6(CDK: cyclin dependent kinase), and p-Rb were decreased significantly in the cells treated with MTE at 40 mg·m L-1. In addition, MTE had an inhibitory effect on the MAPK(mitogen-activated protein kinase) signal transduction pathway, including ERK(extracellular signal-regulated kinase), JNK(c-Jun N-terminal kinase), and p38 MAPK. Moreover, MTE showed little additional effects on the regulation of cyclin D1/D3, CDK4/6, and p-Rb when the ERK pathway was already inhibited by the specific ERK inhibitor U0126. In conclusion, these data suggest that MTE inhibits human esophageal cancer cell proliferation through regulation of cell cycle regulatory proteins and the MAPK signaling pathways, which is probably mediated by the inhibition of ERK activation.展开更多
Cerebral ischemia is one of the leading causes of morbidity and mortality worldwide. Although stroke （a form of cerebral ischemia）-related costs are expected to reach 240.67 billion dollars by 2030, options for trea...Cerebral ischemia is one of the leading causes of morbidity and mortality worldwide. Although stroke （a form of cerebral ischemia）-related costs are expected to reach 240.67 billion dollars by 2030, options for treatment against cerebral ischemia/stroke are limited. All therapies except anti-thrombolytics （i.e., tissue plasminogen activator） and hypothermia have failed to reduce neuronal injury, neurological deficits, and mortality rates following cerebral ischemia, which suggests that development of novel therapies again st stroke/cerebral ischemia are urgently needed. Here, we discuss the possible mechanism（s） underlying cerebral ischemia-induced brain injury, as well as current and future novel therapies （i.e., growth factors, nicotinamide adenine dinucleotide, melatonin, resveratrol, protein kinase C isozymes, pifithrin, hypothermia, fatty acids, sympathoplegic drugs, and stem cells） as it relates to cerebral ischemia.展开更多
AIM： To explore the effect of Astraga/us mongholicus polysaccharide （APS） on gene expression and mitogenactivated protein kinase （MAPK） transcriptional activity in intestinal epithelial cells （IEC）. METHODS： I...AIM： To explore the effect of Astraga/us mongholicus polysaccharide （APS） on gene expression and mitogenactivated protein kinase （MAPK） transcriptional activity in intestinal epithelial cells （IEC）. METHODS： IEC were divided into control group, lipopolysaccharide （LPS） group, LPS＋ 50 μg/mL APS group, LPS＋ 100 μg/mL APS group, LPS＋ 200 μg/mL APS group, and LPS＋ 500 μg/mL APS group. Levels of mRNAs in LPS-induced inflammatory factors, tumor necrosis factor （TNF）-α and interleukin （IL）-8, were measured by reverse transcription-polymerase chain reaction. MAPK protein level was measured by Western blotting. RESULTS： The levels of TNF-α and IL-8 mRNAs were significantly higher in IEC with LPS-induced damage than in control cells. APS significantly abrogated the LPS-induced expression of the TNF-α and IL-8 genes. APS did not block the activation of extracellular signal- regulated kinase or c Jun amino-terminal kinase, but inhibited the activation of p38, suggesting that APS inhibits LPS-induced production of TNF-α and IL-8 mRNAs, possibly by suppressing the p38 signaling pathway.CONCLUSION： APS-modulated bacterial productmediated p38 signaling represents an attractive strategy for prevention and treatment of intestinal inflammation.展开更多
文摘The family members of the mitogen-activated protein (MAP) kinases mediate a wide variety of cellular behaviors in response to extracellular stimuli. One of the four main sub-groups, the p38 group of MAP kinases, serve as a nexus for signal transduction and play a vital role in numerous biological processes. In this review, we highlight the known characteristics and components of the p38 pathway along with the mechanism and consequences of p38 activation. We focus on the role of p38 as a signal transduction mediator and examine the evidence linking p38 to inflammation, cell cycle, cell death, development, cell differentiation, senescence and tumorigenesis in specific cell types. Upstream and downstream components of p38 are described and questions remaining to be answered are posed. Finally, we propose several directions for future research on p38.
基金The National Natural Science Foundation of China, No. 30371816
文摘AIM: To investigate the effects and molecular mechanisms of berberine on improving insulin resistance induced by free fatty acids (FFAs) in 3T3-L1 adipocytes. METHODS: The model of insulin resistance in 3T3-L1 adipocytes was established by adding palmic acid (0.5 mmol/L) to the culture medium. Berberine treatment was performed at the same time. Glucose uptake rate was determined by the 2-deoxy-[3H]-D-glucose method. The levels of IkB kinase beta (IKKβ) Ser181 phosphorylation, insulin receptor substrate-1(IRS-1) Ser307 phosphorylation, expression of IKKβ, IRS-1, nuclear transcription factor kappaB p65 (NF-κB p65), phosphatidylinositol-3-kinase p85 (PI-3K p85) and glucose transporter 4 (GLUT4) proteins were detected by Western blotting. The distribution of NF-κB p65 proteins inside the adipocytes was observed through confocal laser scanning microscopy (CLSM). RESULTS: After the intervention of palmic acid for 24 h, the insulin-stimulated glucose transport in 3T3-L1 adipocytes was inhibited by 67%. Meanwhile, the expression of IRS-1 and PI-3K p85 protein was reduced, while the levels of IKKβ Ser181 and IRS-1 Ser307 phosphorylation, and nuclear translocation of NF-κB p65 protein were increased. However, the above indexes, which indicated the existence of insulin resistance, were reversed by berberine although the expression of GLUT4, IKKβ and total NF-κB p65 protein were not changed during this study. CONCLUSION: Insulin resistance induced by FFAs in 3T3-L1 adipocytes can be improved by berberine. Berberine reversed free-fatty-acid-induced insulin resistance in 3T3-L1 adipocytes through targeting IKKβ.
文摘Ischemia reperfusion injury is a major obstacle in liver resection and liver transplantation surgery.Understanding the mechanisms of liver ischemia reperfusion injury(IRI) and developing strategies to counteract this injury will therefore reduce acute complications in hepatic resection and transplantation,as well as expanding the potential pool of usable donor grafts.The initial liver injury is initiated by reactive oxygen species which cause direct cellular injury and also activate a cascade of molecular mediators leading to microvascular changes,increased apoptosis and acute inflammatory changes with increased hepatocyte necrosis.Some adaptive pathways are activated during reperfusion that reduce the reperfusion injury.IRI involves a complex interplay between neutrophils,natural killer T-cells cells,CD4+ T cell subtypes,cytokines,nitric oxide synthases,haem oxygenase-1,survival kinases such as the signal transducer and activator of transcription,Phosphatidylinositol 3-kinases/Akt and nuclear factor κβ pathways.Transgenic animals,particularly genetic knockout models,have become a powerful tool at elucidating mechanisms of liver ischaemia reperfusion injury and are complementary to pharmacological studies.Targeted disruption of the protein at the genetic level is more specific and maintained than pharmacological inhibitors or stimulants of the same protein.This article reviews the evidence from knockout models of liver IRI about the cellular and molecular mechanisms underlying liver IRI.
基金Supported by National Natural Science Foundation of China(No.81102557)Doctoral Program Foundation of Higher Education of China(No.20104323110001)+4 种基金Key Project of Hunan Province Education Department(No.08A050)Aid Project for Innovation Platform Open Fund of Hunan Province University(No.11K050 and No.14K068)Key Project of Administration of Traditional Chinese Medicine of Hunan Province(No.201301)General Project of Science and Technology Department of Hunan Province(No.2014SK3001)General Project of Education Bureau of Hunan Province(No.11C0963)
文摘Objective： To explore the effects and molecular mechanisms of the combination between total Astragalus extract （TAE） and total Panax notoginseng saponins （TPNS） against cerebral ischemia- reperfusion injury. Methods： C57BL/6 mice were randomly divided into sham-operated group, model group, TAE （110 mg/kg） group, TPNS （115 mg/kg） group, TAE-TPNS combination group and Edaravone （4 mg/kg） group, treated for 4 days, then, cerebral ischemia-repeffusion injury was established by bilateral common carotid artery （CCA） ligation for 20 min followed by reperfusion for 1 and 24 h. Results： TPNS could increase adenosine triphosphate （ATP） level, TAE and TAE-TPNS combination increased ATP, adenosine diphosphate （ADP） contents and Na＋-K＋-ATPase activity, and the effects of TAE-TPNS combination were stronger than those of TAE or TPNS alone after reperfusion for 1 h. After reperfusion for 24 h, TAE, TPNS and TAE-TPNS combination significantly increased neurocyte survival rate and decreased the apoptosis rate as well as down-regulated the expression of phosphorylated c-June N-terminal kinasel/2 （p-JNK1/2）, cytochrome C （Cyt C）, cysteine aspartic acid-specific protease （Caspase）-9 and Caspase-3. Furthermore, the effects in TAE-TPNS combination were better than those in TAE or TPNS alone. Conclusion： The combination of TAE 110 mg/kg and TPNS 115 mg/kg could strengthen protective effects on cerebral ischemia injury, the mechanism underlying might be related to improving jointly the early energy metabolism, and relieving the delayed apoptosis via inhibiting the mitochondrial apoptosis pathway of JNK signal transduction.
文摘The mitogen-activated protein kinases(MAPK) pathway, often known as the RAS-RAFMEK-ERK signal cascade, functions to transmit upstream signals to its downstream effectors to regulate physiological process such as cell proliferation, differentiation, survival and death. As the most frequently mutated signaling pathway in human cancer, targeting the MAPK pathway has long been considered a promising strategy for cancer therapy. Substantial efforts in the past decades have led to the clinical success of BRAF and MEK inhibitors. However, the clinical benefits of these inhibitors are compromised by the frequently occurring acquired resistance due to cancer heterogeneity and genomic instability. This review briefly introduces the key protein kinases involved in this pathway as well as their activation mechanisms. We also generalize the correlations between mutations of MAPK members and human cancers, followed by a summarization of progress made on the development of small molecule MAPK kinases inhibitors. In particular, this review highlights the potential advantages of ERK inhibitors in overcoming resistance to upstream targets and proposes that targeting ERK kinase may hold a promising prospect for cancer therapy.
基金supported by grants from National Key R&D Program of China(Grants 2017YFC0909301 and 2017YFC0909302)National Natural Science Foundation of China(Grants 81874290,81673290,81673455,81602953,and 81903502)the Opening Foundation of State Key Laboratory of Pharmaceutical Biotechnology,Nanjing University,China(Grant KF-GN-201904).
文摘Autophagy,defined as a scavenging process of protein aggregates and damaged organelles mediated by lysosomes,plays a significant role in the quality control of macromolecules and organelles.Since protein kinases are integral to the autophagy process,it is critically important to understand the role of kinases in autophagic regulation.At present,intervention of autophagic processes by small-molecule modulators targeting specific kinases has becoming a reasonable and prevalent strategy for treating several varieties of human disease,especially cancer.In this review,we describe the role of some autophagy-related kinase targets and kinase-mediated phosphorylation mechanisms in autophagy regulation.We also summarize the small-molecule kinase inhibitors/activators of these targets,highlighting the opportunities of these new therapeutic agents.
基金supported by the Young Scientists Foundation of Hubei Provincial Health Department,No.QJX2012-16
文摘Puerarin, a major isoflavonoid derived from the Chinese medical herb radix puerariae （Gegen）, has been reported to inhibit neuronal apoptosis and play an anti-inflammatory role in focal cerebral ischemia model rats. Recent findings regarding stroke pathophysiology have recognized that anti-inflammation is an important target for the treatment of ischemic stroke. The cholinergic anti-inflammatory pathway is a highly robust neural-immune mechanism for inflammation control. This study was to investigate whether activating the cholinergic anti-inflammatory pathway can be involved in the mechanism of inhibiting the inflammatory response during puerarin-induced cerebral ischemia/reperfusion in rats. Results showed that puerarin pretreatment （intravenous injection） re- duced the ischemic infarct volume, improved neurological deficit after cerebral ischemia/reperfusion and decreased the levels of interleukin-1β, interleukin-6 and tumor necrosis factor-a in brain tissue. Pretreatment with puerarin （intravenous injection） attenuated the inflammatory response in rats, which was accompanied by janus-activated kinase 2 （JAK2） and signal transducers and activators of transcription 3 （STAT3） activation and nuclear factor kappa B （NF-KB） inhibition. These observa- tions were inhibited by the alpha7 nicotinic acetylcholine receptor （a7nAchR） antagonist a-bungarotoxin （a-BGT）. In addition, puerarin pretreatment increased the expression of a7nAchR mRNA in ischemic cerebral tissue. These data demonstrate that puerarin pretreatment strongly protects the brain against cerebral ischemia/reperfusion injury and inhibits the inflammatory re- sponse. Our results also indicated that the anti-inflammatory effect of puerarin may partly be medi- ated through the activation of the cholinergic anti-inflammatory pathway.
基金Supported by Hunan Provincial Natural Science Foundation of China,No.03JJY5009
文摘AIM:To investigate whether the apoptotic activities of 8-bromo-7-methoxychrysin(BrMC) involve reactive oxygen species(ROS) generation and c-Jun N-terminal kinase(JNK) activation in human hepatocellular carcinoma cells(HCC).METHODS:HepG2,Bel-7402 and L-02 cell lines were cultured in vitro and the apoptotic effects of BrMC were evaluated by flow cytometry(FCM) after propidium iodide(PI) staining,caspase-3 activity using enzymelinked immunosorbent assay(ELISA),and DNA agarose gel electrophoresis.ROS production was evaluated by FCM after dichlorodihydrofluorescein diacetate(DCHFDA) probe labeling.The phosphorylation level of JNK and c-Jun protein was analyzed by Western blotting.RESULTS:FCM after PI staining showed a dose-dependent increase in the percentage of the sub-G1 cell pop-ulation(P < 0.05),reaching 39.0% ± 2.8% of HepG2 cells after 48 h of treatment with BrMC at 10 μmol/L.The potency of BrMC to HepG2 and Bel-7402(32.1% ± 2.6%) cells was found to be more effective than the lead compound,chrysin(16.2% ± 1.6% for HepG2 cells and 11.0% ± 1.3% for Bel-7402 cell) at 40 μmol/L and similar to 5-flurouracil(33.0% ± 2.1% for HepG2 cells and 29.3% ± 2.3% for Bel-7402 cells) at 10 μmol/L.BrMC had little effect on human embryo liver L-02 cells,with the percentage of sub-G1 cell population 5.4% ± 1.8%.Treatment of HepG2 cells with BrMC for 48 h also increased the levels of active caspase-3,in a concentration-dependent manner.z-DEVD-fmk,a caspase-3specific inhibitor,prevented the activation of caspase-3.Treatment with BrMC at 10 μmol/L for 48 h resulted in the formation of a DNA ladder.Treatment of cells with BrMC(10 μmol/L) increased mean fluorescence intensity of DCHF-DA in HepG2 cells from 7.2 ± 1.12 at 0 h to 79.8 ± 3.9 at 3 h and 89.7 ± 4.7 at 6 h.BrMC did not affect ROS generation in L-02 cells.BrMC treatment failed to induce cell death and caspase-3 activation in HepG2 cells pretreated with N-acetylcysteine(10 mmol/L).In addition,in HepG2 cells treated with BrMC(2.5,5.0,10.0 μmol/L) for 12 h,JNK acti
文摘The number of patients with nonalcoholic fatty liver diseases(NAFLD) including nonalcoholic steatohepatitis(NASH), has been increasing. NASH causes cirrhosis and hepatocellular carcinoma(HCC) and is one of the most serious health problems in the world. The mechanism through which NASH progresses is still largely unknown. Activation of caspases, Bcl-2 family proteins, and c-Jun N-terminal kinase-induced hepatocyte apoptosis plays a role in the activation of NAFLD/NASH. Apoptotic hepatocytes stimulate immune cells and hepatic stellate cells toward the progression of fibrosis in the liver through the production of inflammasomes and cytokines. Abnormalities in glucose and lipid metabolism as well as microbiota accelerate these processes. The production of reactive oxygen species, oxidative stress, and endoplasmic reticulum stress is also involved. Cell death, including apoptosis, seems very important in the progression of NAFLD and NASH. Recently, inhibitors of apoptosis have been developed as drugs for the treatment of NASH and may prevent cirrhosis and HCC. Increased hepatocyte apoptosis may distinguish NASH from NAFLD, and the improvement of apoptosis could play a role in controlling the development of NASH. In this review, the association between apoptosis and NAFLD/NASH are discussed. This review could provide their knowledge, which plays a role in seeing the patients with NAFLD/NASH in daily clinical practice.
基金This work was supported by the Grant from Chinese National Major Project for New Drug Innovation(Grant No.2017ZX09304015)
文摘Background:On May 8,2018,the China National Medical Products Administration(NMPA)approved anlotinib,an orally administered anti-angiogenesis inhibitor,for the treatment of patients with advanced non-small cell lung can-cer(NSCLC)who have progressed after treatment with two or more lines of prior systemic chemotherapy.Main body of the abstract:China NMPA reviewed and inspected a regional double-blinded,placebo-controlled,Phase III trial comparing the overall survival(OS)of NSCLC patients between the anlotinib and placebo arms.A total of 437 patients were randomized(2:1)to receive either anlotinib(n=294)or placebo(n=143)once daily on a 2-week on and 1-week off schedule.Patients with epidermal growth factor receptor(EGFR)or activating anaplastic lymphoma kinase(ALK)genomic tumor aberrations should have disease progression on NMPA-approved therapy.Anlotinib is the first NMPA-approved drug for patients with advanced NSCLC who have progressed on at least two lines of prior systemic chemotherapies in China.The approval was based on a statistically and clinically significant improvement in median OS with anlotinib(9.46 months)compared with placebo[6.37 months;hazard ratio(HR])=0.70,95%confidence interval(CI)=0.55-0.89;two-sided log-rank P=0.002].The confirmed objective response rate(ORR)was 9.2%in the anlotinib arm and 0.7%in the placebo arm.The median duration of response(DoR)was 4.83 months,with a 95%CI of 3.31-6.97 months.The toxicity profile of anlotinib was consistent with that of known anti-angiogenesis inhibitors.Common adverse drug reactions(ADRs)in anlotinib-treated patients included hypertension(67.4%),hand-foot syndrome(43.9%),hemoptysis(14.0%),thyroid stimulating hormone(TSH)elevation(46.6%),and corrected QT interval(QTc)prolongation(26.2%).Short conclusion:Anlotinib demonstrated a clinically significant OS prolongation as a novel therapeutic option for advanced or metastatic NSCLC following at least two lines of chemotherapy.
文摘c-Jun,the most extensively studied protein of the activator protein-1(AP-1)complex,is involved in numerous cell activities,such as proliferation,apoptosis,survival,tumorigenesis and tissue morphogenesis.Earlier studies focused on the structure and function have led to the identification of c-Jun as a basic leucine zipper(bZIP)transcription factor that acts as homo-or heterodimer,binding to DNA and regulating gene transcription.Later on,it was shown that extracellular signals can induce post-translational modifications of c-Jun,resulting in altered transcriptional activity and target gene expression.More recent work has uncovered multiple layers of a complex regulatory scheme in which c-Jun is able to crosstalk,amplify and integrate different signals for tissue development and disease.One example of such scheme is the autocrine amplification loop,in which signal-induced AP-1 activates the c-Jun gene promoter,while increased c-Jun expression feedbacks to potentiate AP-1 activity.Another example of such scheme,based on recent characterization of gene knockout mice,is that c-Jun integrates signals of several developmental pathways,including EGFR-ERK,EGFR-RhoA-ROCK,and activin B-MAP3K1-JNK for embryonic eyelid closure.After more than two decades of extensive research,c-Jun remains at the center stage of a molecular network with mysterious functional properties,some of which are yet to be discovered.In this article,we will provide a brief historical overview of studies on c-Jun regulation and function,and use eyelid development as an example to illustrate the complexity of c-Jun crosstalking with signaling pathways.
基金Supported by the National Natural Science Foundation of China (No. 30300458)
文摘Objective： To study the effect of salvianolic acid B （SAB） and curcumin, the extracts of Solvie Miltiorrhize and Curcume Longe, on the proliferation and activation of hepatic stellate cell （HSC）, and the extracellular signal regulated kinase （ERK） expression in it. Methods： Rat＇s HSC-T6 were cultured and treated by SAB or curcumin. The inhibitory effect on cell proliferation was determined by 3-（4,5-dimthyl-2- 2thiazoly）-2,5-diphenyl-2H-tetrazolium bromide （MTT） colorimetry, and the expression levels of a smooth actin （a-SMA）, collagen type Ⅰ , and ERK were determined by Western blot. Results： SAB and curcumin inhibited the proliferation and activation of rat＇s HSC-T6 in dose-dependent fashion and significantly reduced the expression level of a-SMA （ P〈0.01 ）. Curcumin significantly reduced the expression of collagen type Ⅰ （P〈0.05）. Both SAB and curcumin showed insignificant effect on the ERK expression level, but they could significantly reduce the level of phosphorylated-ERK expression, showing significant difference as compared with that in the control group （ P〈0.01 and P〈0.05 respectively）. Conclusion： SAB and curcumin could significantly inhibit the proliferation, activation of HSC, and the production of type Ⅰ collagen in HSC, the mechanism may be associated with their inhibition on ERK phosphorylation.
基金financially supported by National Natural Science Foundation of China(Nos.81302794,81071841,81102853)the Study of Marsdenia tenacissima extract(MTE):Study on quality control of antitumor traditional Chinese medicine Xiao-Ai-Ping injection(No.2011ZX09201-201)
文摘Marsdenia tenacissima extract(MTE, trade name: Xiao-Ai-Ping injection) is an extract of a single Chinese plant medicine. It has been used for the treatment of cancer in China for decades, especially for esophageal cancer and other cancers in the digestive tract. In the present study, the potential mechanism for MTE's activity in esophageal cancer was explored. The effects of MTE on the proliferation of human esophageal cancer cells(KYSE150 and Eca-109) were investigated by the MTT assay, the Brd U(bromodeoxyuridine) incorporation immunofluorescence assay, and flow cytometric analysis. MTE inhibited cell proliferation through inducing G0/G1 cell cycle arrest in KYSE150 and Eca-109. Western blot analysis was employed to determine protein levels in the MTE treated cells. Compared with the control cells, the expression levels of the cell cycle regulatory proteins cyclin D1/D2/D3, cyclin E1, CDK2/4/6(CDK: cyclin dependent kinase), and p-Rb were decreased significantly in the cells treated with MTE at 40 mg·m L-1. In addition, MTE had an inhibitory effect on the MAPK(mitogen-activated protein kinase) signal transduction pathway, including ERK(extracellular signal-regulated kinase), JNK(c-Jun N-terminal kinase), and p38 MAPK. Moreover, MTE showed little additional effects on the regulation of cyclin D1/D3, CDK4/6, and p-Rb when the ERK pathway was already inhibited by the specific ERK inhibitor U0126. In conclusion, these data suggest that MTE inhibits human esophageal cancer cell proliferation through regulation of cell cycle regulatory proteins and the MAPK signaling pathways, which is probably mediated by the inhibition of ERK activation.
基金supported by the National Institutes of Health/National Institute of Neurological Disorders and Stroke grant 1R01NS096225-01A1the American Heart Association grants AHA-13SDG1395001413,AHA-17GRNT33660336,AHA-17POST33660174+1 种基金the Louisiana State University Grant in Aid research councilThe Malcolm Feist Cardiovascular Research Fellowship
文摘Cerebral ischemia is one of the leading causes of morbidity and mortality worldwide. Although stroke （a form of cerebral ischemia）-related costs are expected to reach 240.67 billion dollars by 2030, options for treatment against cerebral ischemia/stroke are limited. All therapies except anti-thrombolytics （i.e., tissue plasminogen activator） and hypothermia have failed to reduce neuronal injury, neurological deficits, and mortality rates following cerebral ischemia, which suggests that development of novel therapies again st stroke/cerebral ischemia are urgently needed. Here, we discuss the possible mechanism（s） underlying cerebral ischemia-induced brain injury, as well as current and future novel therapies （i.e., growth factors, nicotinamide adenine dinucleotide, melatonin, resveratrol, protein kinase C isozymes, pifithrin, hypothermia, fatty acids, sympathoplegic drugs, and stem cells） as it relates to cerebral ischemia.
文摘AIM： To explore the effect of Astraga/us mongholicus polysaccharide （APS） on gene expression and mitogenactivated protein kinase （MAPK） transcriptional activity in intestinal epithelial cells （IEC）. METHODS： IEC were divided into control group, lipopolysaccharide （LPS） group, LPS＋ 50 μg/mL APS group, LPS＋ 100 μg/mL APS group, LPS＋ 200 μg/mL APS group, and LPS＋ 500 μg/mL APS group. Levels of mRNAs in LPS-induced inflammatory factors, tumor necrosis factor （TNF）-α and interleukin （IL）-8, were measured by reverse transcription-polymerase chain reaction. MAPK protein level was measured by Western blotting. RESULTS： The levels of TNF-α and IL-8 mRNAs were significantly higher in IEC with LPS-induced damage than in control cells. APS significantly abrogated the LPS-induced expression of the TNF-α and IL-8 genes. APS did not block the activation of extracellular signal- regulated kinase or c Jun amino-terminal kinase, but inhibited the activation of p38, suggesting that APS inhibits LPS-induced production of TNF-α and IL-8 mRNAs, possibly by suppressing the p38 signaling pathway.CONCLUSION： APS-modulated bacterial productmediated p38 signaling represents an attractive strategy for prevention and treatment of intestinal inflammation.
