柴胡皂苷D调控CaMKKβ/AMPK信号通路介导ICCs细胞自噬的机制

目的探讨柴胡皂苷D调控CaMKKβ/AMPK信号通路,在功能性消化不良中对胃肠道Cajal间质细胞(Interstitial cells of Cajal,ICCs)细胞自噬的作用及机制。方法分离大鼠原代ICCs细胞,谷氨酸刺激构建ICCs自噬模型,免疫荧光检测Ca2+水平。将原代ICCs细胞分为对照组、模型组、模型+柴胡皂苷D组、模型+CaMKKβ抑制剂组、模型+柴胡皂苷D+CaMKKβ抑制剂组。透射电镜观察自噬体超微结构,ELISA检测Ghrelin和SP的水平,免疫荧光检测Ca2+和LC-3Ⅱ的表达,Western blot检测LC-3Ⅱ/Ⅰ、CaMKKβ、p-AMPK、Drp1、MFN2、IP3R和RyR的蛋白表达水平。结果谷氨酸诱导的模型组ICCs中LC-3Ⅱ荧光表达增强。柴胡皂苷D干预可降低Ca2+浓度,降低CaMKKβ、AMPK和MFN2水平(P<0.01),增加LC-3Ⅱ/Ⅰ、IP3R、RyR、Drp1、Ghrelin和SP水平(P<0.01)。柴胡皂苷D联合CaMKKβ抑制剂STO-609干预后效果更显著。结论柴胡皂苷D可通过CaMKKβ/AMPK信号通路介导Ca2+外流,影响ICCs细胞过度自噬及胃肠动力相关因子的表达。

miR-145-3p通过调控CaMkkβ/AMPK/CREB通路对MPP^(+)诱导PD细胞模型线粒体自噬的影响

目的探讨miR-145-3p对1-甲基-4苯基吡啶离子(MPP^(+))诱导的帕金森病(PD)细胞模型线粒体自噬的影响及其机制。方法将人神经母细胞瘤细胞(SH-SY5Y)分为对照组、模型组、模拟物(mimics)组、钙调蛋白依赖性蛋白激酶激酶β(CaMkkβ)抑制剂(STO-609)组、mimics+STO-609组、环磷酸腺苷反应元件结合蛋白(CREB)抑制剂(KG-501)组、mimics+KG-501组和STO-609+KG-501组。流式细胞术检测细胞凋亡,透射电镜观察自噬体结构,Western blot检测凋亡、自噬和CaMkkβ/腺苷酸活化蛋白激酶(AMPK)/CREB通路相关蛋白的表达。结果与对照组相比,模型组细胞凋亡率、Bcl-2关联X蛋白(Bax)、半胱氨酸蛋白酶-3(Caspase-3)和微管相关蛋白轻链3-I(LC3-Ⅰ)蛋白表达水平均升高(P<0.01),自噬体结构减少,B淋巴细胞瘤-2(Bcl-2)、自噬基因(Beclin-1)、微管相关蛋白轻链3-II(LC3-Ⅱ)、磷酸化钙调蛋白依赖性蛋白激酶激酶β(p-CaMkkβ)、磷酸化腺苷酸活化蛋白激酶(p-AMPK)、磷酸化环磷酸腺苷反应元件结合蛋白(p-CREB)蛋白水平均降低(P<0.01);与模型组相比,mimics组细胞凋亡率、Bax、Caspase-3和LC3-Ⅰ蛋白表达水平降低(P<0.05),自噬体结构增多,Bcl-2、Beclin-1、LC3-Ⅱ、p-CaMkkβ、p-AMPK、p-CREB蛋白水平升高(P<0.05),STO-609组和KG-501组趋势相同均与mimics组相反;与mimics组相比,mimics+STO-609组和mimics+KG-501组细胞凋亡率、Bax、Caspase-3和LC3-Ⅰ蛋白表达水平升高(P<0.01),自噬体结构减少,Bcl-2、Beclin-1、LC3-Ⅱ、p-CaMkkβ、p-AMPK、p-CREB蛋白水平降低(P<0.01);与STO-609组相比,STO-609+KG-501组细胞凋亡率、Bax、Caspase-3和LC3-Ⅰ蛋白表达水平升高(P<0.01),自噬体结构减少,Bcl-2、Beclin-1、LC3-Ⅱ、p-CaMkkβ、p-AMPK、p-CREB蛋白水平降低(P<0.05)。结论miR-145-3p能够抑制MPP^(+)诱导的PD细胞模型的凋亡,促进线粒体自噬,其机制可能与促进CaMkkβ/AMPK/CREB通路的激活有关。

MIR-448 Regulates MAGEA6/AMPK Signaling Pathway in Hepatocellular Carcinoma Tumor Stem Cells

Objective: To explore the role of miR-448 in regulating MAGEA6/AMPK signaling pathway in the biological study of hepatocellular carcinoma (HCC) tumor stem cells. Methods: Using the database, the hepatocellular carcinoma related expression chips were obtained and the regulatory mirnas of candidate genes were predicted, and the predicted results were analyzed. The effects of miR-448 and MAGEA6 on the pellet formation rate and clone formation rate of hepatocellular carcinoma stem cells were detected by immunofluorescence identification of stem cell markers and light microscope counting method. The effects of miR-448 and MAGEA6 on migration and invasion of hepatocellular carcinoma stem cells were detected by scratch and Transwell assay. Dual luciferase reporter assay to verify whether miR-448 targets MAGEA6. The expression and influence of miR-448 on MAGEA6 and AMPK pathway were detected by qRT-PCR and Western blot. Results: It was found that miR-448 may directly regulate the expression of MAGEA6. Overexpression of miR-448 inhibited the characteristics, proliferation, migration, and invasion of hepatocellular carcinoma stem cells in vitro, as well as the ability of xenograft tumor formation in vivo. However, inhibition of miR-448 showed opposite results. In addition, miR-448 directly targets MAGEA6 and regulates AMPK signaling. Silencing MAGEA6 and adding AMPK activator further verified that miR-448 activated AMPK signaling pathway by targeting MAGEA6, thus affecting characteristics, proliferation, migration and invasion of hepatoma stem cells. Conclusions: Our results reveal that miR-448 activates AMPK signaling pathway by targeting MAGEA6, thereby affecting characteristics, proliferation, migration and invasion of hepatoma stem cells. It is suggested that overexpression of miR-448 may be a new therapeutic strategy for hepatocellular carcinoma.

Fanlian Huazhuo Formula alleviates high-fat diet-induced nonalcoholic fatty liver disease by modulating autophagy and lipid synthesis signaling pathway

BACKGROUND Fanlian Huazhuo Formula(FLHZF)has the functions of invigorating spleen and resolving phlegm,clearing heat and purging turbidity.It has been identified to have therapeutic effects on type 2 diabetes mellitus(T2DM)in clinical application.Non-alcoholic fatty liver disease(NAFLD)is frequently diagnosed in patients with T2DM.However,the therapeutic potential of FLHZF on NAFLD and the underlying mechanisms need further investigation.AIM To elucidate the effects of FLHZF on NAFLD and explore the underlying hepatoprotective mechanisms in vivo and in vitro.METHODS HepG2 cells were treated with free fatty acid for 24 hours to induce lipid accumulation cell model.Subsequently,experiments were conducted with the different concentrations of freeze-dried powder of FLHZF for 24 hours.C57BL/6 mice were fed a high-fat diet for 8-week to establish a mouse model of NAFLD,and then treated with the different concentrations of FLHZF for 10 weeks.RESULTS FLHZF had therapeutic potential against lipid accumulation and abnormal changes in biochemical indicators in vivo and in vitro.Further experiments verified that FLHZF alleviated abnormal lipid metabolism might by reducing oxidative stress,regulating the AMPKα/SREBP-1C signaling pathway,activating autophagy,and inhibiting hepatocyte apoptosis.CONCLUSION FLHZF alleviates abnormal lipid metabolism in NAFLD models by regulating reactive oxygen species,autophagy,apoptosis,and lipid synthesis signaling pathways,indicating its potential for clinical application in NAFLD.

Effect and Mechanism of Dicliptera chinensis Polysaccharide on miR-141/AMPK/SIRT1 Signaling Pathway in Rats with NAFLD

[Objectives]Non-alcoholic fatty liver disease(NAFLD)rat model was established by feeding high-fat and high-sugar fodder to rats,and the protective effect of Dicliptera chinensis polysaccharide(DCP)on NAFLD rats was studied to explore its potential mechanism.[Methods]45 SD rats were randomly divided into 4 groups:normal control group,model control group and DCP treatment groups(100 and 300 mg/kg).The rats in the normal control group were fed with ordinary fodder,and the rats in other groups were fed with high-fat and high-sugar diet for 14 weeks to establish NAFLD model.From the 9^(th)week,the rats in the DCP treatment groups were given different doses of DCP by intragastric administration(5 mL/kg)for 6 weeks.After the last intragastric administration,the rats fasted for 16 h,and the serum and liver of rats were collected for detection.Hematoxylin-eosin(HE)staining was conducted to observe the histopathological changes of rat liver,and alanine aminotransferase(ALT),aspartate aminotransferase(AST),superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),malondialdehyde(MDA),triglyceride(TG),total cholesterol(TC),low density lipoprotein cholesterol(LDL-C),and high density lipoprotein cholesterol(HDL-C)were detected by biochemical method.Interleukin-6(IL-6),interleukin-1β(IL-1β),tumor necrosis factor(TNF-α)and micrornA-141(micro RNA-141)were detected by reverse transcription-polymerase chain reaction(RT-PCR).The expression of SIRT1 and adenosine 5'-monophosphate(AMP)-activated protein kinase(AMPK)in rat liver was detected by western blot.[Results]Compared with the model control group,the inflammatory damage and steatodegeneration of rats in the DCP groups were relieved to varying degrees,and the number of lipid vacuoles significantly reduced.The ALT,AST,TC,TG and LDL-C content in the serum and MDA content in the liver tissue decreased to varying degrees,while the HDL-C,SOD and GSH-Px content increased.The expression of SIRT1 and AMPK increased,while the expression of miR-141,TNF-α,IL-6 and IL-1βdeclined,and the DCP 300 mg/kg treatment group had better improvement effect.[Conclusions]DCP had a certain protective effect on NAFLD rats,which may be related to the regulation of miR-141/AMPK/SIRT1 signaling pathway.

茶黄素调节CaMKK2/AMPK信号通路对脑出血大鼠神经元凋亡和血脑屏障的影响

目的:探讨茶黄素(TFs)通过调节钙调蛋白激酶激酶2(CaMKK2)/单磷酸腺苷活化蛋白激酶(AMPK)信号通路对脑出血大鼠神经元凋亡和血脑屏障(BBB)的影响。方法:选取90只大鼠随机分为假手术组、模型组、TFs低剂量组(20 mg/kg TFs)、TFs高剂量组(40 mg/kg TFs)、TFs高剂量+STO-609组(40 mg/kg TFs+10μL CaMKK2抑制剂-STO-609)、阳性对照组(2 mg/kg尼莫地平注射液),每组15只。采用VII型胶原酶诱导脑出血大鼠模型。对大鼠行为学以及脑组织含水量进行检测;分离大鼠血清,检验炎症因子-血管黏附因子-1(VCAM-1)、肿瘤坏死因子-α(TNF-α)、细胞间黏附因子-1(ICAM-1)水平;取血肿周围脑组织,检测神经元凋亡、BBB通透性参数-伊文思蓝(EB)水平以及p-CaMKK2/CaMKK2、p-AMPK/AMPK和凋亡相关蛋白Bax表达情况。结果:模型组大鼠神经行为学评分(mNSS评分)、ICAM-1、TNF-α、VCAM-1、脑组织含水量、凋亡率、EB水平以及Bax蛋白表达较假手术组均增加,p-CaMKK2/CaMKK2、p-AMPK/AMPK均降低(P<0.05);TFs低、高剂量组、阳性对照组大鼠mNSS评分、ICAM-1、TNF-α、VCAM-1、脑组织含水量、凋亡率、EB水平以及Bax表达较模型组均降低,p-CaMKK2/CaMKK2、p-AMPK/AMPK均增加(P<0.05);与TFs高剂量相比,TFs高剂量+STO-609组大鼠mNSS评分、ICAM-1、TNF-α、VCAM-1、脑组织含水量、凋亡率、EB水平以及Bax表达均增加,p-CaMKK2/CaMKK2、p-AMPK/AMPK降低(P<0.05)。结论:TFs可降低神经元凋亡、炎症反应、BBB通透性,对脑出血损伤大鼠发挥保护作用,其作用机制可能与激活CaMKK2/AMPK信号通路有关。

基于CaMkkβ/AMPK通路介导线粒体自噬探讨敛肝熄风止颤方的神经保护机制

目的:观察敛肝熄风止颤方对帕金森病(Parkinson Disease,PD)的影响,探讨其神经保护机制。方法:将60只SD大鼠分为假手术组10只,造模组50只,造模组大鼠接受PD模型制备,将成模的40只大鼠随机分为模型组10只、低剂量组(0.36 g/kg)10只、中剂量组(0.72 g/kg)及高剂量组(1.44 g/kg)10只,持续灌胃给药30 d,比较各组大鼠阿扑吗啡诱导旋转次数、圆筒实验,纹状体超微结构以及CaMkkβ、AMPK、p-AMPK水平的变化。结果:1)敛肝熄风止颤方可明显减少大鼠转圈以及肢体碰壁的次数,随着剂量增加次数减少更明显,差异有统计学意义(P<0.05)。2)造模大鼠纹状体线粒体自噬现象减弱,敛肝熄风止颤方可明显促进脑组织线粒体自噬。3)中药干预后大鼠纹状体CaMkkβ、p-AMPK蛋白表达上调,与模型组比较,差异有统计学意义(P<0.05),其中高剂量组较低剂量组上调明显,差异有统计学意义(P<0.05)。结论:敛肝熄风止颤方对帕金森病具有神经保护作用,其机制之一可能是通过激活CaMkk/AMPK通路活性促进线粒体自噬有关。

CaMKKβ通过激活AMPK/JAK2/STAT3信号促进小鼠单核巨噬细胞向M2表型转换

目的·探明钙离子/钙调蛋白依赖性蛋白激酶激酶β(CaMKKβ)在白介素4(IL-4)诱导的RAW264.7细胞极化过程中的作用和机制。方法·RT-PCR和ELISA检测IL-4诱导RAW264.7细胞极化水平,Western blotting测定极化过程中CaMKKβ、AMPK、JAK2、STAT3蛋白表达及磷酸化水平。慢病毒为载体的shRNA稳定干扰RAW264.7细胞CaMKKβ表达,RT-PCR和ELISA检测IL-4诱导下细胞极化水平的改变,Western blotting检测AMPK、JAK2、STAT3蛋白及磷酸化蛋白的表达。分别特异性阻断AMPK、JAK2和STAT3蛋白活性,经RT-PCR检测IL-4诱导下RAW264.7细胞极化水平的改变。结果·IL-4主要诱导RAW264.7细胞向M2型巨噬细胞极化(P<0.05),且CaMKKβ、AMPK、JAK2、STAT3的磷酸化水平明显升高(均P<0.05)。shRNA稳定干扰RAW264.7细胞CaMKKβ表达后,IL-4促进巨噬细胞向M2型极化作用降低(P<0.05),且AMPK、JAK2和STAT3的磷酸化水平降低(均P<0.05)。分别阻断AMPK、JAK2和STAT3,巨噬细胞向M2型极化减少(均P<0.05)。结论·CaMKKβ通过激活AMPK/JAK2/STAT3信号通路,促进IL-4诱导的巨噬细胞M2型极化。

利拉鲁肽通过激活CAMKK2/AMPK通路促进骨骼肌FNDC5的表达

目的:探讨利拉鲁肽(LG)对骨骼肌细胞Ⅲ型纤连蛋白结构域包含蛋白5(fibronectin typeⅢdomain-containing protein 5,FNDC5)表达水平的影响并探讨其机制。方法:小鼠成肌细胞系C2C12经诱导分化后,给予梯度浓度(1~1 000 nmol/L)LG处理不同时间(0~24 h),观察LG对FNDC5表达及磷酸化腺苷酸活化蛋白激酶(adenosine 5'-monophosphate-activated protein kinase,AMPK)信号通路活性的影响,以及应用胰高血糖素样肽1(glucagon-like peptide-1,GLP-1)受体拮抗剂exendin_(9-39)、钙/钙调素依赖的蛋白激酶激酶2(Ca^(2+)/calmodulin-dependent protein kinase kinase 2,CAMKK2)的抑制剂STO609或AMPK的抑制剂Compound C预处理C2C12肌管细胞,观察FNDC5蛋白表达的改变。AMPK的活性及FNDC5的表达用Western blot法检测。结果:LG能够促进C2C12骨骼肌细胞FNDC5的蛋白表达,并具有剂量及时间依赖性,同时激活AMPK。LG的上述作用可被exendin_(9-39)、STO609或Compound C阻断。结论:利拉鲁肽可促进C2C12小鼠骨骼肌细胞合成FNDC5,此作用依赖于GLP-1受体,可能是通过激活CAMKK2/AMPK信号通路实现的。

Liraglutide reduces oxidized LDL-induced oxidative stress and fatty degen- eration in Raw 264.7 cells involving the AMPK/SREBP1 pathway

Baekgound Recent studies have suggested a potential role for liraglutide in the prevention and stabilization ofatherosclerotic vascular disease. However, the molecular mechanisms underlying the effect of liraglutide on atherosclerosis have not been well elucidated. The pur- pose of this study was to examine whether liraglutide protects against oxidative stress and fatty degeneration via modulation of AMP-activated protein kinase （AMPK）/sterol regulatory element binding transcription factor 1 （SREBP1） signaling pathway in foam ceils. Methods Mouse macrophages Raw264.7 cells were exposed to oxidized low density lipoprotein （oxLDL） to induce the formation of foam cells. The cells were incubated with oxLDL （50 μg/mL）, liraglutide （0.1, 0.5, 1 and 2 nmol/L） or exendin-3 （9-39） （1, 10 and 100 nmol/L） alone, or in combination. Oil Red O staining was used to detect intracellular lipid droplets. The levels of TG and cholesterol were measured using the commercial kits. Oxidative stress was determined by measuring intracellular reactive oxygen species （ROS）, malondialdehyde （MDA） and superoxide dismutase 1 （SOD）. Western blot analysis was used to examine the expression of AMPKal, SREBP1, phosphory- lated AMPKal, phosphorylated SREBP1, glucagon-like peptide-1 （GLP-1） and GLP-1 receptor （GLP-1R）. Results Oil Red O staining showed that the cytoplasmic lipid droplet accumulation was visibly decreased in foam cells by treatment with liraglutide. The TG and cholesterol content in the liraglutide-treated foam cells was significantly decreased. In addition, foam ceils manifested an impaired oxidative stress following liraglutide treatment, as evidenced by increased SOD, and decreased ROS and MDA. However, these effects of liraglutide on foam cells were attenuated by the use of GLP-IR antagonist exendin-3 （9-39）. Furthermore, we found that the expression level of AMPKa 1 and phosphorylated AMPKct 1 was significantly increased while the expression level of SREBP 1 and phosphorylated SREBP 1 was significantly decreased in foam cells following treatment with liraglutide. Conclusions This study for the first time demonstrated that the effect of liraglutide on reducing oxidative stress and fatty degeneration in oxLDL-induced Raw264.7 cells is accompanied by the alteration of AMPK/SREBP1 pathway. This study provided a potential molecular mechanism for the effect of liraglutide on reducing oxidative stress and fatty degeneration.

Puerarin protects rat brain against ischemia/reperfusion injury by suppressing autophagy via the AMPK-mT OR-ULK1 signaling pathway

Puerarin suppresses autophagy to alleviate cerebral ischemia/reperfusion injury, and accumulating evidence indicates that the AMPKm TOR signaling pathway regulates the activation of the autophagy pathway through the coordinated phosphorylation of ULK1. In this study, we investigated the mechanisms underlying the neuroprotective effect of puerarin and its role in modulating autophagy via the AMPK-m TOR-ULK1 signaling pathway in the rat middle cerebral artery occlusion model of cerebral ischemia/reperfusion injury. Rats were intraperitoneally injected with puerarin, 50 or 100 mg/kg, daily for 7 days. Then, 30 minutes after the final administration, rats were subjected to transient middle cerebral artery occlusion for 90 minutes. Then, after 24 hours of reperfusion, the Longa score and infarct volume were evaluated in each group. Autophagosome formation was observed by transmission electron microscopy. LC3, Beclin-1 p62, AMPK, m TOR and ULK1 protein expression levels were examined by immunofluorescence and western blot assay. Puerarin substantially reduced the Longa score and infarct volume, and it lessened autophagosome formation in the hippocampal CA1 area following cerebral ischemia/reperfusion injury in a dose-dependent manner. Pretreatment with puerarin（50 or 100 mg/kg） reduced Beclin-1 expression and the LC3-II/LC3-I ratio, as well as p-AMPK and p S317-ULK1 levels. In comparison, it increased p62 expression. Furthermore, puerarin at 100 mg/kg dramatically increased the levels of p-m TOR and p S757-ULK1 in the hippocampus on the ischemic side. Our findings suggest that puerarin alleviates autophagy by activating the APMK-m TOR-ULK1 signaling pathway. Thus, puerarin might have therapeutic potential for treating cerebral ischemia/reperfusion injury.

Jian-Gan-Xiao-Zhi decoction ameliorates high-fat high-carbohydrate diet-induced non-alcoholic fatty liver disease and insulin resistance by regulating the AMPK/JNK pathway

Background:Non-alcoholic fatty liver disease(NAFLD)can cause insulin resistance(IR)and diabetes.Our previous studies have demonstrated that Jian-Gan-Xiao-Zhi decoction(JGXZ)could be effective for the treatment of NAFLD and IR.However,the possible mechanism underlying the effects of JGXZ on NAFLD and IR remains unknown.Methods:Fifty rats received a high-fat high-carbohydrate(HFHC)diet for 12 weeks to induce NAFLD.After 4 weeks of HFHC treatment,rats were orally treated with JGXZ(8,16,and 32 g/kg weight)for 8 weeks.Ten rats in the control group received standard chow.In the positive control group,rats were orally treated with metformin(90 mg/kg weight)for 8 weeks.After JGXZ and metformin treatment,H&E staining was conducted on rat livers and serum biochemical markers,including alanine aminotransferase(ALT),aspartate aminotransferase(AST),triglyceride(TG),and total cholesterol(TC),were measured using test kits.Moreover,a fasting blood glucose test and an oral glucose tolerance test(OGTT)were conducted.Serum levels of insulin were determined using ELISA kit,and the homeostatic model assessment of insulin resistance(HOMA-IR)was calculated.The levels of total insulin receptor substrate-1(IRS1),AMP-activated protein kinase-α(AMPKα)and c-Jun N-terminal kinase(JNK)as well as the levels of phosphorylation of IRS1(p-IRS1),phosphorylation of AMPK(p-AMPK)and phosphorylation of JNK(p-JNK)were measured using western blotting.Results:The body weights in JGXZ low-,middle-,and high-dose groups were lower than those in the model group(P<0.05,P<0.01,P<0.01,respectively).The serum levels of AST(P<0.05 in JGXZ middle-and high-dose groups),ALT(P<0.01 in JGXZ middle-dose group and P<0.05 in JGXZ high-dose group),TG(P<0.01 in JGXZ middle-and high-dose groups),and TC(P<0.01)upon JGXZ treatment were lower those than in NAFLD model rats.H&E staining showed that JGXZ treatment reduced steatosis of the hepatocytes in NAFLD model rats.JGXZ decreased the levels of fasting blood glucose(P<0.01),HOMA-IR(P<0.01),AUC(area under the curve)of the OGTT(P<0.05)and p-IRS1(P<0.01 in JGXZ middle-and high-dose groups,P<0.05 in JGXZ low-dose groups).Moreover,JGXZ regulated the hepatic AMPKα/JNK pathway in NAFLD model rats,which reflected the induction of p-AMPKαand inhibition of p-JNK.Conclusion:This study showed that JGXZ improved liver function and reduced steatosis of the hepatocytes in NAFLD model rats.Moreover,JGXZ improved IR in NAFLD model rats.The possible mechanism underlying the effects of JGXZ on NAFLD and IR involves the modulation of the AMPK/JNK pathway.

近视视网膜病变与CaMKKβ/AMPK信号通路的相关性

多项研究发现,目前近视的患病率在全球范围内成爆发性增长,且逐渐呈低龄化趋势。伴随着近视进展,屈光度不断增加、眼轴进行性的延长会引起一系列的眼部并发症,例如视网膜萎缩、视网膜脱离、视网膜变薄及撕裂等。Ca^(2+)/钙调蛋白活化的蛋白激酶-β(Ca^(2+)/calmodulin-dependent protein kinase kinaseβ,CaMKKβ)/腺苷单磷酸激活的蛋白激酶(adenosine monophosphate-activated protein kinase,AMPK)信号通路是调节细胞能量代谢的经典途径之一,CaMKKβ响应于Ca^(2+)的增加而通过磷酸化激活AMPK,进一步激活自噬。近期研究发现近视视网膜病变与CaMKKβ/AMPK信号通路密切相关,故本文将主要探讨和介绍近视患者的视网膜病变与CaMKKβ/AMPK信号通路的相关性。

Artemisinin protected human SY5Y and hippocampal neurons from H2O2-induced oxidative damage through activation of AMPK pathway

Oxidative stress is one of the main causes of neurodegenerative diseases such as Alzheimer disease(AD).Our previous studies have shown that artemisinin,a anti-malaria Chinese medicine,with neuroprotective effect,however,the antioxidative effect of artemisinin and its potential mechanism remain to be elucidated.In the present study,the protective effect and the underlying mechanism of artemisinin against injury of hydrogen peroxide(H_2O_2) in SH-SY5Y and hippocampal neurons were studied.Our results show that artemisinin protected SH-SY5Y and hippocampal neuronal cells from H_2O_2-induced cell death at clinically relevant concentrations in a concentration-dependent manner.Further studies showed that artemisinin significantly reduced cell death caused by H_2O_2 by restoring nuclear morphology,abnormal changes in intracellular ROS,activation of caspase 3,lactate dehydrogenase release and mitochondrial membrane potential.Hoechst staining and flow cytometry showed that artemisinin significantly reduced the apoptosis of SH-SY5Y cells exposed to H_2O_2.Western blotting analysis showed that artemisinin stimulated the phosphorylation and activation of AMP-activated protein kinase(AMPK) in SH-SY5Y cells in a time and concentration-dependent manner,whereas the application of AMPK inhibitor Compound C or decrease in expression of AMPKα with shRNA specific for AMPKα blocked the protective effect of artemisinin.Similar results were obtained in primary cultured hippocampal neurons.Taken together,these results indicate that artemisinin can protect neuronal cells from oxidative damage,at least in part through the activation of AMPK.Because artemisinin is relatively inexpensive and has few side effects,our findings support the role of artemisinin as a potential therapeutic agent for neurodegenerative diseases.

Mu-Xiang-You-Fang protects PC12 cells against OGD/R-induced autophagy via AMPK/mTOR signaling pathway

OBJECTIVE Mu-Xiang-You-Fang(MXYF)is a classic prescription of Hui medicine,composed of five herbs,which has been used to treat ischemic stroke for many years.However,the potential pharmacological mecha⁃nisms of MXYF remain unclear.The present research is to investigate the neuroprotective effect of MXYF and its role in modulating autophagy via AMPK/mTOR signaling pathway in the PC12 oxygen-glucose deprivation and reperfusion(OGD/R)injury model.METHODS MXYF was extracted by supercritical CO2 fluid extraction apparatus.PC12 OGD/R injury model was established by oxygen-glucose deprivation for 2 h and reperfusion for 24 h.The effects of MXYF on the viability and cytotoxicity of PC12 cells were determined through cell counting kit(CCK-8)assay.Colorimetric method was performed to determine the LDH leakage rate.The calcium concentration was determined by chemical fluorescence method and the mitochondrial membrane potential was determined through flow cytometry.Monodansylcadaverine(MDC)staining was conducted to detect autophagosome formation.The expression of LC3,Beclin1,p62,p-AMPK,ULK1,p-mTOR and p-p70s6k proteins were determined by immunofluorescence and Western blotting analyses.RESULTS MXYF(1,2 and 4 mg·L^-1)could significantly increase the cell viability and mitochondrial membrane potential,while decreased the release of lactate dehydrogenase(LDH)and calcium concentration in PC12 cells.Mechanistic studies showed that MXYF reduced the LC3-II/LC3-I ratio and inhibited the expression of beclin1,p-AMPK and ULK1.In comparison,the expres⁃sion of p-mTOR,p-p70s6k and p62 were significantly enhanced.CONCLUSION MXYF inhibits autophagy after OGD/Rinduced PC12 cell injury through AMPK-mTOR pathway,thus MXYF might have therapeutic potential for treating the ischemic stroke.

CHANGES IN NEUROPEPTIDES AFTER MUSIC EXPOSURE 429Cardioprotective effect of ivabradine via the AMPK/SIRT1/PGC-1αsignaling pathway in myocardial ischemia/reperfusion injuryinduced in H9c2 cell

Post-resuscitation myocardial dysfunction(PRMD)is the most severe myocardial ischemia-reperfusion injury(MIRI)and is characterized by difficult treatment and poor prognosis.Research has shown the protective effects of the rational use of ivabradine(IVA)against PRMD,however,the molecular mechanisms of IVA remain unknown.In this study,an ischemia-reperfusion injury(IRI)model was established using hypoxic chambers.The results demonstrated that pretreatment with IVA reduced IRI-induced cytotoxicity and apoptosis.IVA attenuated mitochondrial damage,eliminated excess reactive oxygen species(ROS),suppressed IRI-induced ATP and NAD+,and increased the AMP/ATP ratio.We further found that IVA increased the mRNA levels of sirtuin 1(SIRT1)and peroxisome proliferator-activated receptor-γcoactivator 1α(PGC-1α)and upregulated the expression levels of phosphorylated AMP-activated protein kinase(p-AMPK)/AMPK,SIRT1,and PGC-1αproteins.Interestingly,no change in AMPK mRNA levels was observed.Cardiomyocyte energy metabolism significantly changed after IRI.The aim of this study was to demonstrate the cardioprotective effect of Ivabradine via the AMPK/SIRT1/PGC-1αsignaling pathway in myocardial ischemia/reperfusion injury-induced in H9c2 cell.

Main alkaloids of Rhizoma Coptidis improved palmitic acidinduced insulin resistance in HepG2 cells via AMPK and MAPK signaling pathway

Rhizoma Coptidis,a traditional Chinese herbal medicine,has been used for treating diabetes for thousands of years.However,the molecular basis for this action has not been elucidated.In the present study,the effects of seven main alkaloids of Rhizoma Coptidis on glycometabolism were investigated and the related molecular mechanism of five active compounds on insulin resistant(IR)cell model was explored for the first time.Results showed that berberine,palmatine,epiberberine,columbamine and groenlandicine enhanced glucose consumption in the palmitic acid(PA)-induced IR-HepG2 cells,indicating that these compounds could improve IR.In addition,we found that among these active alkaloids,berberine,columbamine,epiberberine and groenlandicine could inhibit the activation of ERK and p38 pathway,while berberine,columbamine,palmatine and epiberberine could activate AMPK pathway.Moreover,palmatine and columbamine regulated the mRNA expression of GLUT2 to ameliorate IR via activating AMPK and inactivating p38 MAPK signal pathway.To sum up,berberine,columbamine,palmatine,epiberberine and groenlandicine might be the active reagents,which contribute to the glucose lowering effects of Rhizoma Coptidis.

Analysis of feasibility of application of Beishu point acupressure therapy in treating gastroesophageal reflux disease via AMPK / ULK1 mediated autophagy pathway based on "adjusting central axis via pivot" theory

Gastroesophageal reflux disease(GERD)is a digestive system disease characterized by uncomfortable symptoms caused by reflux of gastric contents.It has increased sharply with the development of my country’s society and economy.If there is no reasonable and effective Prevention and treatment measures will inevitably increase the financial burden of patients,and also pose a major threat to the quality of life and health of patients.Cell signal transduction mediated by various receptors participates in the regulation mechanism of the body's various levels of biological functions.By inhibiting or activating its functions,the purpose of curing diseases can be achieved,and cell signal transduction has been used in traditional Chinese medicine.Studying.The theory of"adjusting the central axis"was explored by Professor Xie Sheng through decades of clinical experience.It has been proven in practice to treat GERD.It starts from the model of TCM viscera and expounds that the pathogenesis of GERD involves multiple viscera.Multi-system and multi-factor,explain the correlation of the disease with a variety of zang-fu syndromes,and use this as a basis to guide the clinical use of hidden prescriptions.The back-shu pointer therapy can prevent GERD by correcting the unbalanced state of the viscera and qi machine,and promoting the junction of the two channels of Ren and Du.Based on the theory of"adjusting the hub by the pivot",this article expounds the pathogenesis of GERD from the perspective of traditional Chinese medicine.By consulting the literature and combining with the previous research,it proposes to analyze the methods and methods of Backshu pointer therapy to prevent and treat GERD from the AMPK/ULK1 mediated autophagy pathway.

Yiqi Yangyin and Huatan Quyu granule can improve skeletal muscle energy metabolism in a type 2 diabetic rat model by promoting the AMPK/SIRT/PGC-1α signalling pathway

Objective:To investigate how Yiqi Yangyin and Huatan Quyu granule (YYHO) improves skeletal muscle insulin resistance in a type 2 diabetic rat model and to discover whether the molecular mechanism is related to the promotion of the AMPK/SIRT/PGC-1α signalling pathway.Methods:Rats were randomly divided into 4 groups:the normal group,the model group,the YYHQ granule group,and the pioglitazone group.The type 2 diabetic rat model was established by feeding a high-fat diet for 5 weeks along with a single intraperitoneal injection of 30 mg/kg streptozotocin (STZ).After modelling successfully,the appropriate drug was intragastrically administered to diabetic rats for 2 weeks,once per day.The YYHQ granule group was given a dose of 4.8 g/kg body weight per day,the pioglitazone group was given a dose of 1.35 mg/kg body weight per day.The doses for both groups were equivalent to the clinical equivalent dose based on a previous study.Other groups were gavaged with the same amount of saline water.Body weight,food intake,water intake,urine volume and grip strength were recorded weekly.The fasting blood glucose(FBG) was determined weekly using blood glucose test strips.The related glucose and lipid metabolism indexes,e.g.,fasting insulin (Fins),glycated haemoglobin (GHb),HOMA-IR,ISI,triglycerides (TG),total cholesterol (TC),high-density lipoprotein cholesterol (HDL-C),low-density lipoprotein cholesterol (LDL-C) and free fatty acid (FFA),were determined using biochemical method.The mRNA expression levels of adenosine monophosphate-activated protein kinase (AMPK),peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α),carnitine palmitoyl transterase-1 (CPT-1),Sirtuin 1 (SIRT1),and Sirtuin 3 (SIRT3) were assessed using quantitative real-time PCR (qRT-PCR).The protein expression levels of creatine kinase (CK),Ca2+ ATPase,α-Actin,AMPK,PGC-1α and CPT-1 were determined using enzyme-linked immunosorbent assay method (ELISA).Results:Body weight decreased significantly (P <.01),food intake,water intake and urine volume increased significantly (P <.01),and grip strength decreased significantly (P <.01) in the model group compared with the normal group.The levels of FBG,Fins,GHb and HOMA-IR increased significantly (P <.01),and the ISI decreased significantly (P <.01) in the model group.The levels of TG,TC,LDL-C and FFA increased significantly (P <.05 or P <.01),and the level of HDL-C decreased significantly (P <.05) in the model group.These changes were reversed after treatment with YYHQ granule or pioglitazone.Compared with the model group,the YYHQ granule and pioglitazone groups significantly improve body weight,water intake and urine volume (P <.05 or P <.01),however,both treatments had no significant effect on food intake (P >.05).The levels of FBG,Fins,GHb,HOMA-IR and ISI were improved significantly (P <.01) and the levels of TG,TC and LDL-C were improved significantly (P <.05 or P <.01),however,both treatments had no significant effect on the levels of HDL-C and FFA (P >.05).Further results indicated that YYHQ granule significantly decreased the mRNA expression of AMPK,PGC-1α,CPT-1,SIRT1 and SIRT3 in skeletal muscle (P <.01) and the pioglitazone group showed similar effects;moreover,the protein expression levels of CK,Ca2+ATPase,α-Actin,AMPK,PGC-1α and CPT-1 in skeletal muscle significantly decreased (P <.01),however,pioglitazone had no significant effect on CK and α-Actin (P >.05).Conclusion:The possible molecular mechanism of YYHQ granule improving skeletal muscle insulin resistance in a type 2 diabetic rat model may be related to the stimulation of energy metabolism in skeletal muscle via the AMPK/SIRT/PGC-1α signalling pathway.

CaMKK2通过调控AMPK通路减轻肺缺血再灌注损伤

目的探讨CaMKK2是否通过调控AMPK通路减轻肺缺血再灌注损伤。方法45只8周龄健康雄性C57BL/6小鼠随机分为假手术组(Sham组)、肺缺血再灌注组(IR组)和IR+CaMKK2抑制剂组(CaMKK2inhibitor组),每组15只,建立缺血再灌注诱导的肺缺血再灌注损伤(LIRI)小鼠模型,通过生存分析评价小鼠存活率,血气分析评价小鼠呼吸功能,肺湿干重比评价肺水肿,HE染色评价肺组织病理情况,Westernblot实验分析肺组织NF-κB、TNF-α及CaMKK2/AMPK/mTOR信号通路蛋白表达。结果抑制CaMKK2会增加LIRI导致的小鼠死亡率,加重肺水肿和呼吸功能障碍(P<0.05),增加肺组织炎细胞浸润,增加肺组织炎症蛋白NF-κB和TNF-α的表达,加重LIRI导致的磷酸化AMPK减少和磷酸化mTOR的增多(P<0.05)。结论CaMKK2/AMPK/mTOR信号通路参与调控LIRI的炎症反应。