Metformin promotes angiogenesis and functional recovery in aged mice after spinal cord injury by adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway

Treatment with metformin can lead to the recovery of pleiotropic biological activities after spinal cord injury.However,its effect on spinal cord injury in aged mice remains unclear.Considering the essential role of angiogenesis during the regeneration process,we hypothesized that metformin activates the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway in endothelial cells,thereby promoting microvascular regeneration in aged mice after spinal cord injury.In this study,we established young and aged mouse models of contusive spinal cord injury using a modified Allen method.We found that aging hindered the recovery of neurological function and the formation of blood vessels in the spinal cord.Treatment with metformin promoted spinal cord microvascular endothelial cell migration and blood vessel formation in vitro.Furthermore,intraperitoneal injection of metformin in an in vivo model promoted endothelial cell proliferation and increased the density of new blood vessels in the spinal cord,thereby improving neurological function.The role of metformin was reversed by compound C,an adenosine monophosphate-activated protein kinase inhibitor,both in vivo and in vitro,suggesting that the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway likely regulates metformin-mediated angiogenesis after spinal cord injury.These findings suggest that metformin promotes vascular regeneration in the injured spinal cord by activating the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway,thereby improving the neurological function of aged mice after spinal cord injury.

Amino acids regulate energy utilization through mammalian target of rapamycin complex 1 and adenosine monophosphate activated protein kinase pathway in porcine enterocytes

As major fuels for the small intestinal mucosa,dietary amino acids(AA)are catabolized in the mitochondria and serve as sources of energy production.The present study was conducted to investigate AA metabolism that supply cell energy and the underlying signaling pathways in porcine enterocytes.Intestinal porcine epithelial cells(IPEC-J2)were treated with different concentrations of AA,inhibitor,or agonist of mammalian target of rapamycin complex 1(mTORCl)and adenosine monophosphate activated protein kinase(AMPK),and mitochondrial respiration was monitored.The results showed that AA treatments resulted in enhanced mitochondrial respiration,increased intracellular content of pyruvic acid and lactic acid,and increased hormone-sensitive lipase mRNA expression.Meanwhile,decreased citrate synthase,isocitrate dehydrogenase alpha,and carnitine palmitoyltransferase 1 mRNA expression were also observed.We found that AA treatments increased the protein levels of phosphorylated mammalian target of rapamycin(p-mTOR),phosphorylated-p70 ribosomal protein S6 kinase,and phosphorylated-4 E-binding protein 1.What is more,the protein levels of phosphorylated AMPKα(pAMPKa)and nicotinamide adenine dinucleotide(NAD)-dependent protein deacetylase sirtuin-1(SIRT1)were decreased by AA treatments in a time depending manner.Mitochondrial bioenergetics and the production of tricarboxylic acid cycle intermediates were decreased upon inhibition of mTORCl or AMPK.Moreover,AMPK activation could up-regulate the mRNA expressions of inhibitor of nuclear factor kappa-B kinase subunit beta(Ikbk(3),integrin-linked protein kinase(ILK),unconventional myosin-Ic(Myolc),ribosomal protein S6 kinase beta-2(RPS6 Kβ2),and vascular endothelial growth factor(VEGF)-β,which are downstream effectors of mammalian target of rapamycin(mTOR).The mRNA expressions of phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit delta isoform(PIK3 CD)and5’-AMP-activated protein kinase subunit gamma-1(PRKAG1),which are upstream regulators of mTOR,were also up-regulated by AMPK activation.On the other hand,AMPK activation also down-regulated FK506-binding protein 1 A(FKBP1 A),serine/threonine-protein phosphatase 2 A 55 kDa regulatory subunit B beta isoform,phosphatase and tensin homolog(PTEN),and unc-51 like autophagy activating kinase 1(Ulkl),which are up-stream regulators of mTORCl.Taken together,these data indicated that AA regulated cellular energy metabolism through mTOR and AMPK pathway in porcine enterocytes.These results demonstrated interactions of AMPK and mTORCl pathways in AA catabolism and energy metabolism in intestinal mucosa cells of piglets,and also provided reference for using AA to remedy human intestinal diseases.

Electroacupuncture preconditioning attenuates ischemic brain injury by activation of the adenosine monophosphate-activated protein kinase signaling pathway

Electroacupuncture has therapeutic effects on ischemic brain injury, but its mechanism is still poorly understood. In this study, mice were stimulated by electroacupuncture at the Baihui（GV20） acupoint for 30 minutes at 1 m A and 2/15 Hz for 5 consecutive days. A cerebral ischemia model was established by ligating the bilateral common carotid artery for 15 minutes. At 72 hours after injury, neuronal injury in the mouse hippocampus had lessened, and the number of terminal deoxynucleotide transferase-mediated d UTP nick-end labeling-positive cells reduced after electroacupuncture treatment. Moreover, expression of adenosine monophosphate-activated protein kinase α（AMPKα） and phosphorylated AMPKα was up-regulated. Intraperitoneal injection of the AMPK antagonist, compound C, suppressed this phenomenon. Our findings suggest that electroacupuncture preconditioning alleviates ischemic brain injury via AMPK activation.

Adenosine monophosphate-activated protein kinase activation enhances embryonic neural stem cell apoptosis in a mouse model of amyotrophic lateral sclerosis

Alterations in embryonic neural stem cells play crucial roles in the pathogenesis of amyotrophic lateral sclerosis. We hypothesized that embryonic neural stem cells from SOD1G93A individuals might be more susceptible to oxidative injury, resulting in a propensity for neurodegeneration at later stages. In this study, embryonic neural stem cells obtained from human superoxide dis- mutase 1 mutant （SOD1G93A） and wild-type （SOD1wv） mouse models were exposed to H202. We assayed cell viability with mitochondrial succinic dehydrogenase colorimetric reagent, and measured cell apoptosis by flow cytometry. Moreover, we evaluated the expression of the adenos- ine monophosphate-activated protein kinase （AMPK） ct-subunit, paired box 3 （Pax3） protein, and p53 in western blot analyses. Compared with SOD1wr cells, SOD1~93A embryonic neural stem cells were more likely to undergo H202-induced apoptosis. Phosphorylation of AMPKct in SOD1G93A cells was higher than that in SOD1wr cells. Pax3 expression was inversely correlated with the phosphorylation levels of AMPKct. p53 protein levels were also correlated with AMPKct phosphorylation levels. Compound C, an inhibitor of AMPKa, attenuated the effects of H20~. These results suggest that embryonic neural stem cells from SOD1C93A mice are more susceptible to apoptosis in the presence of oxidative stress compared with those from wild-type controls, and the effects are mainly mediated by Pax3 and p53 in the AMPKa pathway.

Neuroprotective mechanisms of rutin for spinal cord injury through anti-oxidation and anti-inflammation and inhibition of p38 mitogen activated protein kinase pathway

Rutin has anti-inflammatory, antioxidant, anti-viral, anti-tumor and immune regulatory effects. However, the neuroprotective effects of rutin in spinal cord injury are unknown. The p38 mitogen activated protein kinase （p38 MAPK） pathway is the most important member of the MAPK family that controls inflammation. We assumed that the mechanism of rutin in the repair of spinal cord injury is associated with the inhibition of p38 MAPK pathway. Allen’s method was used to establish a rat model of spinal cord injury. The rat model was intraperitoneally injected with rutin （30 mg/kg） for 3 days. After treatment with rutin, Basso, Beattie and Bresnahan locomotor function scores increased. Water content, tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6 levels, p38 MAPK protein expression and caspase-3 and -9 activities in T8–9 spinal cord decreased. Oxidative stress related markers superoxide dismutase and glutathione peroxidase levels increased in peripheral blood. Rutin exerts neuroprotective effect through anti-oxidation, anti-inflammation, anti-apoptosis and inhibition of p38 MAPK pathway.

Metformin attenuates motility,contraction,and fibrogenic response of hepatic stellate cells in vivo and in vitro by activating AMP-activated protein kinase

AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon tetrachloride(CCl_4) and subsequent treatment with or without metformin. The level of fibrosis was detected by hematoxylin-eosin staining, Sirius Red staining, and immunohistochemistry. The HSC cell line LX-2 was used for in vitro studies. The effect of metformin on cell proliferation(CCK8 assay),motility(scratch test and Transwell assay), contraction(collagen gel contraction assay), extracellular matrix(ECM) secretion(Western blot), and angiogenesis(ELISA and tube formation assay) was investigated. We also analyzed the possible signaling pathways involved by Western blot analysis.RESULTS Mice developed marked liver fibrosis after intraperitoneal injection with CCl_4 for 6 wk. Metformin decreased the activation of HSCs, reduced the deposition of ECM, and inhibited angiogenesis in CCl_4-treated mice. Platelet-derived growth factor(PDGF) promoted the fibrogenic response of HSCs in vitro, while metformin inhibited the activation, proliferation, migration, and contraction of HSCs, and reduced the secretion of ECM. Metformin decreased the expression of vascular endothelial growth factor(VEGF) in HSCs through inhibition of hypoxia inducible factor(HIF)-1α in both PDGF-BB treatment and hypoxic conditions, and it down-regulated VEGF secretion by HSCs and inhibited HSC-based angiogenesis in hypoxic conditions in vitro. The inhibitory effects of metformin on activated HSCs were mediated by inhibiting the Akt/mammalian target of rapamycin(m TOR) and extracellular signal-regulated kinase(ERK) pathways via the activation of adenosine monophosphate-activated protein kinase(AMPK).CONCLUSION Metformin attenuates the fibrogenic response of HSCs in vivo and in vitro, and may therefore be useful for the treatment of chronic liver diseases.

Adenosine triphosphate promotes locomotor recovery after spinal cord injury by activating mammalian target of rapamycin pathway in rats

The mammalian target of rapamycin （mTOR） pathway plays an important role in neuronal growth, proliferation and differentiation. To better understand the role of mTOR pathway involved in the induction of spinal cord injury, rat models of spinal cord injury were established by modified Allen＇s stall method and interfered for 7 days by intraperitoneal administration of mTOR activator adenosine triphosphate and mTOR kinase inhibitor rapamycin. At 1-4 weeks after spinal cord injury induction, the Basso, Beattie and Bresnahan locomotor rating scale was used to evaluate rat locomotor function, and immunohistochemical staining and western blot analysis were used to detect the expression of nestin （neural stem cell marker）, neuronal nuclei （neuronal marker）, neuron specific enolase, neurofilament protein 200 （axonal marker）, glial fibrillary acidic protein （astrocyte marker）, Akt, mTOR and signal transduction and activator of transcription 3 （STAT3）. Results showed that adenosine triphosphate-mediated Akt/mTOR/STAT3 pathway increased endogenous neural stem cells, induced neurogenesis and axonal growth, inhibited excessive astrogliosis and improved the locomotor function of rats with spinal cord injury.

Effects of Ginsenoside Rb1 on Skeletal Muscle Insulin Resistance and Adenosine Monophosphate?activated Protein Kinase Signaling Pathway in Obese Mice

Objectives: The objective of the study is to observe the effects of ginsenoside Rb1 on indexes of body weight, body composition, blood lipid, skeletal muscle endurance, and insulin sensitivity in obese mice, probe into its pharmacological action, and further explore its effects on adenosine monophosphate-activated protein kinase(AMPK) signaling pathway in skeletal muscle. Materials and Methods: Eight-week-old C57 BL/6 J mice were fed with high-fat diet for 12 weeks to establish obese mouse model. The model-establishment obese mice were randomly divided into three groups including model control group, metformin group, and ginsenoside Rb1 group. In the normal control group, normal diet was administered. The intervention period was 8 weeks. Body weight and food intake of the mice were measured regularly every week. The treadmill test was performed at weeks 3 and 7, and the oral glucose tolerance test was carried out at weeks 4 and 8. Body composition of the mice was detected by applying NMR Animal Body Composition Analyzer at week 8. Four parameters of blood lipids and free fatty acid(FFA)levels were detected. The m RNA expression of AMPKα and proliferator-activated receptor gamma coactivator-1α(PGC-1α) in skeletal muscle was examined by real-time fluorescence quantitative polymerase chain reaction, and the influence of ginsenoside Rb1 on protein expression of AMPKα, p-AMPKα, and PGC-1α was observed by western blotting. Results: The body weight(since the 5 th week of drug administration)and food intake of the mice in the ginsenoside Rb1 group were significantly lower than those in the model control group(P < 0.05) in a time-dependent manner. Ginsenoside Rb1 could significantly reduce the levels of triglyceride and low-density lipoprotein cholesterol, while increase the high-density lipoprotein cholesterol level(P < 0.05). In addition, ginsenoside Rb1 could reduce the serum FFA level(P < 0.05).After the administration of ginsenoside Rb1 for 8 weeks, the body fat mass of obese mice decreased and the lean mass increased(P < 0.05).The skeletal muscle endurance and the oral glucose tolerance of the obese mice improved using ginsenoside Rb1. At the molecular level,ginsenoside Rb1 could up-regulate the mRNA and protein expression of AMPKα in skeletal muscle, and increase the content of p-AMPK protein significantly(P < 0.01). At the same time, the mRNA and protein level of PGC-1α was also un-regulated, correspondingly(P < 0.01).Conclusion: Ginsenoside Rb1 exerts effects on reducing body weight, decreasing blood lipid levels, enhancing the skeletal muscle endurance,and increasing the insulin sensitivity in obese mice by activating the related proteins in AMPK signaling pathway in skeletal muscle.

淫羊藿苷调控mTOR/Akt/CREB通路对高糖诱导的足细胞自噬及凋亡的影响

目的 探讨淫羊藿苷对高糖诱导的足细胞自噬、凋亡及哺乳动物雷帕霉素靶蛋白(mTOR)/丝氨酸苏氨酸蛋白激酶(Akt)/环磷酸腺苷反应元件结合蛋白(CREB)通路的影响。方法 将小鼠足细胞MPC5分为5组:正常对照组(5.5 mmol·L^(-1)葡萄糖)、高糖组(30 mmol·L^(-1)葡萄糖)、淫羊藿苷组(30 mmol·L^(-1)葡萄糖+5μmol·L^(-1)淫羊藿苷)、GDC-0349组(30 mmol·L^(-1)葡萄糖+50μmol·L^(-1)GDC-0349)、淫羊藿苷+GDC-0349组(30 mmol·L^(-1)葡萄糖+5μmol·L^(-1)淫羊藿苷+50μmol·L^(-1)GDC-0349)。培养48 h后,噻唑蓝法检测MPC5细胞活力;吖啶橙染色观察MPC5细胞自噬情况;流式细胞术检测MPC5细胞凋亡;蛋白印迹法检测MPC5细胞自噬[微管相关蛋白1轻链3(LC3)Ⅱ、LC3Ⅰ、自噬相关蛋白(Beclin-1)]、凋亡[Bcl-2相关X蛋白(Bax)、B淋巴细胞瘤-2(Bcl-2)]和mTOR/Akt/CREB通路相关蛋白的表达。结果 与正常对照组比较,高糖组MPC5细胞活力、Bcl-2、磷酸化mTOR(p-mTOR)/mTOR、磷酸化Akt(p-Akt)/Akt、磷酸化CREB(p-CREB)/CREB蛋白表达水平显著降低(P<0.05),自噬能力增强,自噬体表现出橙色荧光,细胞凋亡率、LC3Ⅱ/LC3Ⅰ、Beclin-1、Bax蛋白表达水平显著升高(P<0.05)。与高糖组比较,淫羊藿苷组MPC5细胞活力、LC3Ⅱ/LC3Ⅰ、Beclin-1、Bcl-2、p-mTOR/mTOR、p-Akt/Akt、p-CREB/CREB蛋白表达水平显著升高,自噬能力进一步增强,自噬体数量增多,自噬体呈现出砖红色荧光(P<0.05),细胞凋亡率、Bax蛋白表达水平显著降低(P<0.05);GDC-0349组MPC5细胞活力、LC3Ⅱ/LC3Ⅰ、Beclin-1、Bcl-2、p-mTOR/mTOR、p-Akt/Akt、p-CREB/CREB蛋白表达水平显著降低,自噬能力减弱,自噬体数量减少,自噬体表现出橙色荧光(P<0.05),细胞凋亡率、Bax蛋白表达水平显著升高(P<0.05);淫羊藿苷+GDC-0349可逆转淫羊藿苷对高糖诱导MPC5细胞的作用效果(P<0.05)。结论 淫羊藿苷通过激活mTOR/Akt/CREB通路促进高糖诱导的足细胞自噬抑制细胞凋亡。

黄芩苷调节cAMP/PKA/CREB信号通路对湿疹大鼠皮肤屏障功能的影响

目的探讨黄芩苷(BA)调节环磷酸腺苷(cAMP)/蛋白激酶A(PKA)/cAMP反应元件结合蛋白(CREB)通路对湿疹大鼠皮肤屏障功能的影响。方法将SD大鼠随机分为对照组(NC组)、Model组、低剂量BA组(BA-L组,25 mg/kg)、中剂量BA组(BA-M组,50 mg/kg)、高剂量BA组(BA-H组,100 mg/kg)、泼尼松组(PNS组,25 mg/kg)、BAH+cAMP抑制剂(SQ22536)组(100 mg/kg+2.13 mg/kg)、BA-H+PKA抑制剂(H-89)组(100 mg/kg+5 mg/kg),每组12只。除NC组外,其余组大鼠均构建湿疹大鼠模型。建模成功2 d后,分组进行给药处理。检测湿疹面积及严重度指数(EASI)评分、经皮肤水分流失量(TEWL)、角质层含水量(WCSC)变化;酶联免疫吸附试验(ELISA)检测大鼠血清中免疫球蛋白E(IgE)、干扰素-γ(IFN-γ)、白细胞介素-4(IL-4)水平及大鼠背部受试区皮损组织中c AMP蛋白表达;HE染色检测大鼠背部受试区皮损组织病理变化;Western blot检测大鼠背部受试区皮损组织中水通道蛋白3(AQP3)、cathelicidin相关抗菌肽(CRAMP)、p-PKA、p-CREB蛋白表达。结果与NC组比较,Model组大鼠背部受试区皮损组织病理损伤严重,EASI评分、TEWL、IgE、IL-4水平升高,WCSC、IFN-γ水平、AQP3、CRAMP、cAMP、p-PKA、p-CREB蛋白水平降低(P<0.05)。与Model组比较,BA-L组、BA-M组、BA-H组、PNS组大鼠背部受试区皮损组织病理损伤减轻,EASI评分、TEWL、IgE、IL-4水平降低,WCSC、IFN-γ水平、AQP3、CRAMP、cAMP、p-PKA、p-CREB蛋白水平升高(P<0.05);且BA-L组、BA-M组、BA-H组上述指标变化呈剂量依赖性。SQ22536或H-89减弱了高剂量BA对湿疹大鼠皮肤屏障功能的改善作用。结论BA可能通过激活cAMP/PKA/CREB信号通路改善湿疹大鼠皮肤屏障功能。

补阳还五汤对糖尿病周围神经病变大鼠的止痛作用及机制研究

【目的】探讨补阳还五汤对糖尿病周围神经病变(DPN)大鼠的止痛作用及机制。【方法】将60只大鼠分为正常组,模型组(MNCV)和感觉神经传导速度(SNCV),中药低、中、高剂量组,中药高剂量+H-89[蛋白激酶A(PKA)抑制剂]组,每组10只。除正常组,其他各组大鼠采用高脂高糖饲料饲喂结合腹腔注射链脲佐菌素(STZ)法构建DPN模型。给药结束后,检测大鼠足热痛阈值,测定大鼠运动神经传导速度(MNCV)和感觉神经传导速度(SNCV),免疫组织化学法观察表皮内神经纤维密度(IENF),酶联免疫吸附分析(ELISA)检测血清空腹胰岛素(FINS)、总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、胰岛素抵抗指数(HOMA-IR),白细胞介素(IL)-1β、IL-6、肿瘤坏死因子α(TNF-α),血管内皮生长因子(VEGF)、血管生成素1(Ang-1)、CD34水平,坐骨神经组织中环磷酸腺苷(cAMP)浓度,Western Blot法检测坐骨神经组织中PKA和反应元件结合蛋白(CREB)表达水平。【结果】与正常组比较,模型组足热痛阈值,TC、TG、LDL-C、HOMA-IR,IL-1β、IL-6和TNF-α水平均显著增加(P<0.05),HDL-C、FINS,VEGF、Ang-1、CD34,IENF,MNCV和SNCV值,cAMP浓度水平,PKA和CREB磷酸化水平均显著降低(P<0.05);与模型组比较,中药低、中、高剂量组上述指标均得到显著改善(P<0.05),且呈剂量依赖性;与中药高剂量+H-89组比较,中药高剂量组各指标水平均被逆转。【结论】补阳还五汤可改善DPN大鼠胰岛素抵抗、血脂代谢,减轻肢体疼痛,改善局部微循环障碍,保护神经功能,体现了“活血通络止痛”的治疗特点;补阳还五汤的止痛作用可能与改善局部微循环障碍、抑制炎症因子释放及调节cAMP/PKA/CREB信号通路蛋白表达有关。

柚皮素对口腔鳞状细胞癌细胞的干预作用研究

目的:探究柚皮素(NRG)对口腔鳞状细胞癌(OSCC)细胞增殖、凋亡、迁移与侵袭的影响。方法:采用浓度(μmol/L)为0、5、10、15、20、25、30的NRG处理OSCC CAL-27细胞,CCK-8法检测细胞活力;将CAL-27细胞分为低、中、高剂量NRG组(NRG-L、NRG-M组、NRG-H组)、Compound C(AMPK抑制剂)组、NRG-H+Compound C组、对照组(NC组,正常培养),CCK-8与EdU染色、流式细胞术、划痕实验、Transwell分别检测细胞增殖、凋亡、迁移、侵袭;Western blot检测天冬氨酸特异性半胱氨酸蛋白酶-3(Caspase-3)、增殖细胞核抗原(PCNA)、基质金属蛋白酶(MMP)-2、MMP-9、磷酸化腺苷酸活化蛋白激酶(p-AMPK)、沉默信息调节蛋白1(SIRT1)、乙酰化核因子κB p65(Ac-NF-κB p65)蛋白表达。结果:选取5、10、20μmol/L NRG分别作为后续处理CAL-27细胞的低、中、高剂量;与NC组比较,NRG-L组、NRG-M组、NRG-H组EdU阳性率、划痕愈合率、A 450值、侵袭细胞数及MMP-2、PCNA、MMP-9、Ac-NF-κB p65蛋白下调,细胞凋亡率及p-AMPK、Caspase-3、SIRT1蛋白上调(P<0.05);与NC组相比,Compound C组EdU阳性率、划痕愈合率、A 450值、侵袭细胞数及MMP-2、PCNA、MMP-9、Ac-NF-κB p65蛋白升高,细胞凋亡率及p-AMPK、Caspase-3、SIRT1蛋白表达下调(P<0.05);Compound C逆转了高剂量NRG对CAL-27细胞增殖、迁移、凋亡及侵袭的影响。结论:NRG抑制CAL-27细胞增殖、迁移与侵袭,并诱导细胞凋亡,其机制可能与激活AMPK进而抑制NF-κB通路有关。

金合欢素调节Sirt1/AMPK/Nrf2信号通路对糖尿病白内障大鼠氧化应激损伤的影响

目的探讨金合欢素对糖尿病白内障(DC)大鼠氧化应激损伤的影响及其对沉默调节蛋白1(Sirt1)/腺苷酸活化蛋白激酶(AMPK)/核因子E2相关因子2(Nrf2)信号通路的调控作用。方法60只SD大鼠随机分为对照组、模型组、金合欢素低剂量组、金合欢素高剂量组、金合欢素+Sirt1抑制剂(EX527)组,除对照组以外均构建DC大鼠模型,其中,金合欢素低剂量组、金合欢素高剂量组大鼠分别经颈部皮下注射10 mg·kg^(-1)、20 mg·kg^(-1)的金合欢素,金合欢素+EX527组大鼠经颈部皮下注射20 mg·kg^(-1)金合欢素,均为每天2次,同时金合欢素+EX527组大鼠经皮下埋入渗透微型泵每天泵入3.5 mg·kg^(-1)EX527,其余组别均泵入等量生理盐水,给药持续4周。给药结束后,测量血压和空腹血糖(FBG),裂隙灯照射法观察大鼠晶状体混浊状况,HE染色观察晶状体组织病理学变化,ELISA测定血清丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、白细胞介素(IL)-6、IL-1β的含量,Western blot检测Sirt1、p-AMPK、AMPK、Nrf2蛋白表达水平。结果与对照组相比,模型组大鼠晶状体上皮细胞呈片状、条索状,发生迁移性聚集,收缩压、FBG、晶状体混浊评分、MDA、IL-6、IL-1β水平均升高,SOD、GSH-Px含量及Sirt1、p-AMPK/AMPK、Nrf2蛋白表达水平均降低(均为P<0.05);与模型组比较,金合欢素低、高剂量组大鼠晶状体上皮细胞迁移性聚集现象改善,收缩压、FBG、晶状体混浊评分、MDA、IL-6、IL-1β水平均降低,SOD、GSH-Px含量及Sirt1、p-AMPK/AMPK、Nrf2蛋白表达水平均升高(均为P<0.05);与金合欢素高剂量组比较,金合欢素+EX527组晶状体上皮细胞形态改变和聚集现象加重,收缩压、FBG、晶状体混浊评分、MDA、IL-6、IL-1β水平均升高,SOD、GSH-Px含量及Sirt1、p-AMPK/AMPK、Nrf2蛋白表达水平均降低(均为P<0.05)。结论金合欢素可能通过激活Sirt1/AMPK/Nrf2通路保护DC大鼠免受氧化应激损伤。

红景天苷改善顺铂引起的小鼠耳蜗毛细胞和螺旋神经节神经元损伤的机制

目的探究红景天苷(SAL)改善顺铂(CIS)引起的耳蜗毛细胞(CHC)和螺旋神经节神经元(SGN)损伤的作用及其与环磷腺苷(cAMP)/蛋白激酶A(PKA)/cAMP效应元件结合蛋白(CREB)通路的关系。方法分离新生C57BL/6小鼠的耳蜗基底膜,分为对照组(C组)、CIS组、SAL组、SAL+SQ22536(cAMP抑制剂)组和SAL+H-89(PKA抑制剂)组,每组20条。C组仅加入无血清BME培养液;CIS组在培养液中加入15μmol/L CIS;SAL组在CIS组基础上加入5μmol/L SAL;SAL+SQ22536组在CIS组基础上加入5μmol/L SAL和5μmol/L SQ22536;SAL+H-89组在CIS组基础上加入5μmol/L SAL和30μmol/L H-89。各组在培养箱中孵育48 h后,免疫荧光染色观察各组CHC和SGN损伤;试剂盒检测各组耳蜗基底膜中ROS和cAMP含量;Western blot检测各组PKA、p-CREB、CREB、Bcl-2、BDNF、NF-M蛋白水平。结果CIS组CHC排列混乱、体积肿大,SGN细胞核破碎、神经突缺失,SAL可减轻CHC和SGNs损伤。与C组相比,CIS组CHC、SGN数量较少(P<0.05),ROS、cAMP含量、PKA、BDNF、NF-M、Bcl-2蛋白及p-CREB/CREB水平较高(P<0.05);与CIS组相比,SAL组CHC、SGN数量较多(P<0.05),ROS含量较低(P<0.05),cAMP含量、PKA、BDNF、NF-M、Bcl-2蛋白及p-CREB/CREB水平较高(P<0.05)。SQ22536和H-89均可逆转SAL对CHC和SGN的保护作用。结论SAL可能通过激活cAMP/PKA/CREB通路,促进抗凋亡蛋白和神经保护因子表达,缓解CIS引起的CHC和SGN损伤。

基于“肾脑相济”理论探讨艾灸对阿尔茨海默病大鼠海马AMPK/mTOR信号通路的影响

目的观察艾灸对阿尔茨海默病(Alzheimer’s disease,AD)大鼠腺苷酸活化蛋白激酶(adenosine 5-monophosphate activated protein kinase,AMPK)/雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)信号通路相关递质表达的影响,探讨艾灸治疗AD的作用机制。方法将SD大鼠按照随机数字表法分为正常组8只、模型组32只,采取侧脑室注射β淀粉样蛋白(amyloidβ-protein,Aβ)_(25-35)的方法建立大鼠AD模型。将模型复制成功的大鼠随机分为模型组、药物组、艾灸组,每组8只。艾灸组大鼠用艾条灸“百会”“肾俞”“三阴交”,每次15 min,同时按3 mg/kg灌胃蒸馏水;药物组大鼠按3 mg/kg灌胃盐酸多奈哌齐;对照组及模型组大鼠按3 mg/kg灌胃蒸馏水。采用Morris水迷宫法检测大鼠行为学表现,苏木精—伊红染色法观察大鼠海马病理组织改变,Western blot法检测大鼠海马磷酸化雷帕霉素靶蛋白(phosphorylated mammalian target of rapamycin,p-mTOR)、核糖体蛋白S6激酶(ribosomal protein S6 kinase p70,P70S6K)、自噬相关基因5(autophagy-related gene 5,ATG5)、磷酸化腺苷酸活化蛋白激酶(phosphorylated adenosine 5-monophosphate activated protein kinase,p-AMPK)、微管相关蛋白1轻链3B(microtubule associated protein light chain 3B,LC3B)-Ⅱ/LC3B-Ⅰ的表达水平。结果苏木精—伊红染色结果表明,模型组海马神经元萎缩明显,与模型组比较,药物组和艾灸组海马神经元形态及分化程度均有明显改善。与正常组比较,模型组大鼠的逃避潜伏期显著延长(P<0.05),p-mTOR及P70S6K表达水平均显著升高(P<0.05),ATG5、LC3B-Ⅱ/LC3B-Ⅰ、p-AMPK表达水平均显著降低(P<0.05)。与模型组比较,药物组和艾灸组大鼠的逃避潜伏期均显著缩短(P<0.05),p-mTOR及P70S6K表达水平均显著下降(P<0.05),ATG5、LC3B-Ⅱ/LC3B-Ⅰ、p-AMPK表达水平均显著上升(P<0.05)。与药物组比较,艾灸组大鼠逃避潜伏期显著缩短(P<0.05);p-mTOR及P70S6K表达水平显著降低(P<0.05),ATG5、LC3B-Ⅱ/LC3B-Ⅰ、p-AMPK表达水平均显著上升(P<0.05)。结论艾灸能够调控AMPK/mTOR信号通路,诱导细胞自噬,阻断脑内Aβ表达,从而改善认知功能。

基于环磷酸腺苷/蛋白激酶A/环磷酸腺苷反应元件结合蛋白通路探究丙泊酚对局灶性脑缺血再灌注大鼠神经功能改善机制

目的:基于环磷酸腺苷/蛋白激酶A/环磷酸腺苷反应元件结合蛋白(cAMP/PKA/CREB)通路探究丙泊酚对局灶性脑缺血再灌注大鼠神经功能的改善机制。方法:采用改良线栓法缺血2 h,再灌注24 h建立大鼠脑缺血再灌注损伤(CIRI)模型,将造模成功大鼠随机分为模型组和丙泊酚低(1 mg/ml)、中(2.5 mg/ml)、高剂量(5 mg/ml)组,各12只,另设含有12只大鼠的假手术组。分组后即开始给药,1次/d,共4周,末次给药12 h后,采用改良神经功能评分(mNSS)法进行神经缺损评分;采用TTC染色法检测脑梗死面积;HE、Nissl染色进行神经元细胞及尼氏小体形态学观察;Tunel法进行神经元细胞凋亡检测;Elisa法检测脑组织cAMP、脑源性神经营养因子(BDNF)、神经生长因子(NGF)含量;免疫荧光法检测脑组织环磷酸腺苷(cAMP)、p-PKA、p-CREB阳性细胞数及其蛋白共表达阳性细胞数;Western blot法检测脑组织PKA、p-PKA、CREB、p-CREB蛋白表达量。结果:模型组大鼠比较假手术组大鼠的mNSS评分、脑梗死面积百分比显著增加(均P<0.05),HE染色和Nissl染色可见明显的神经元细胞损伤和尼氏小体破坏,脑组织cAMP、BDNF、NGF含量和PKA、p-PKA、CREB、p-CREB蛋白表达量显著下降,模型组大鼠比较假手术组大鼠的cAMP、p-PKA、p-CREB阳性细胞数和蛋白共表达阳性细胞数也明显下降(均P<0.05)。与模型组比较,丙泊酚给药组大鼠mNSS评分、脑梗死面积百分比显著降低(均P<0.05),HE染色和Nissl染色可见神经元细胞损伤和尼氏小体破坏有不同程度改善,脑组织cAMP、BDNF、NGF含量和PKA、p-PKA、CREB、p-CREB蛋白表达量显著升高(均P<0.05),cAMP、p-PKA、p-CREB阳性细胞数及其蛋白共表达阳性细胞数均显著升高(均P<0.05)。结论:丙泊酚可能通过cAMP/PKA/CREB通路改善CIRI大鼠神经功能。

胡黄连苷Ⅱ调节cAMP/PKA信号轴对脊髓损伤大鼠神经功能恢复的影响

目的探讨胡黄连苷Ⅱ(PicrosideⅡ,PⅡ)对脊髓损伤(spinal cord injury,SCI)大鼠神经功能恢复的影响及对环磷酸腺苷(cAMP)-蛋白激酶A(PKA)信号通路的调节作用。方法建立SCI大鼠模型,大鼠分为正常组(CT组)、SCI模型组(SCI组)、PⅡ低剂量组(PⅡL组,5 mg·kg^(-1)·d^(-1))、PⅡ高剂量组(PⅡH组,20 mg·kg^(-1)·d^(-1))和PⅡ高剂量+PKA抑制剂组(PⅡH+H-89组,20 mg·kg^(-1)·d^(-1) PⅡ+5 mg·kg^(-1)·d^(-1)),每组18只。Basso-Beattie-Bresnahan(BBB)评分评价SCI大鼠运动功能,HE染色评价脊髓组织病理学特征,劳克坚牢蓝(LFB)染色观察脱髓鞘情况,免疫荧光检测胶质纤维酸性蛋白(GFAP)、离子钙结合适配器分子-1(IBA-1)表达,ELISA检测丙二醛(MDA)、超氧化物歧化酶(SOD)、环腺苷酸(cAMP)的含量,Western blot检测磷酸化(p)-PKA、PKA、p-环磷酸腺苷反应成分结合蛋白(CREB)、CREB蛋白表达。结果与CT组比较,SCI组大鼠脊髓组织缺损、空腔,大量炎性细胞浸润,脱髓鞘以及GFAP、IBA-1、MDA表达增加,BBB评分以及SOD、cAMP、p-PKA/PKA、p-CREB/CREB表达减少(P<0.05);与SCI组比较,PⅡL组、PⅡH组组织损伤改善,空腔及炎性细胞减少,脱髓鞘以及GFAP、IBA-1、MDA表达降低,BBB评分以及SOD、cAMP、p-PKA/PKA、p-CREB/CREB表达增加(P<0.05);与PⅡH组比较,PⅡH+H-89组组织损伤严重,脱髓鞘以及GFAP、IBA-1、MDA表达增加,BBB评分以及SOD、cAMP、p-PKA/PKA、p-CREB/CREB表达减少(P<0.05)。结论PⅡ可能通过激活cAMP/PKA信号轴促进SCI大鼠神经功能恢复。

牡荆素调控AMPK/NLRP3途径介导的细胞焦亡对大鼠急性咽炎的作用机制研究

目的:基于AMPK/NLRP3信号通路探究牡荆素对大鼠急性咽炎的影响及其调控机制。方法:60只SD大鼠随机分为对照组、模型组、阿莫西林组和牡荆素低、中、高剂量组,每组各10只。除对照组外,其余各组大鼠均采用咽部定向喷射25%氨水的方法构建急性咽炎模型。牡荆素各剂量组大鼠分别腹腔注射3、6、12 mg/kg牡荆素;阿莫西林组大鼠给予0.36 g/kg阿莫西林灌胃;其余腹腔注射等量0.9%生理盐水。各组大鼠于给药干预7 d后进行行为状态评分、咽部组织病理学染色观察,并进行血清炎症因子IL-6、IL-1β、TNF-α、PGE_(2)检测,筛选出牡荆素最佳给药剂量;同时检测咽部组织焦亡相关蛋白及AMPK/NLRP3表达。随后将40只SD大鼠随机分为对照组、模型组、牡荆素组(腹腔注射12 mg/kg牡荆素)、牡荆素+CC(AMPK抑制剂)组(腹腔注射12 mg/kg牡荆素后,立刻注射20 mg/kgCC),每组各10只。除对照组外,其余各组大鼠均采用咽部定向喷射25%氨水的方法构建急性咽炎,造模后使用相应药物干预,1次/d,共干预7 d。苏木素-伊红(HE)染色观察咽部组织病理学变化;酶联免疫吸附法(ELISA)测定血清IL-6、IL-1β、TNF-α、PGE_(2)水平;Western blot检测咽部组织AMPK/NLRP3通路及细胞焦亡相关蛋白表达。结果:与模型组相比,牡荆素各剂量组大鼠行为状态评分均显著降低(P<0.05),血清IL-6、IL-1β、TNF-α、PGE_(2)水平降低(P<0.05),咽部组织病理性损伤明显减轻,且呈剂量相关性,筛选得出牡荆素12 mg/kg为最佳给药剂量。与模型组相比,牡荆素组大鼠咽部组织p-AMPK蛋白阳性率明显升高,NLRP3蛋白阳性率明显降低,细胞焦亡相关蛋白表达明显降低(P<0.05)。与牡荆素组相比,牡荆素+CC组大鼠咽部组织损伤程度加重,血清IL-6、IL-1β、TNF-α、PGE_(2)水平,细胞焦亡相关蛋白和NLRP3蛋白表达显著升高,p-AMPK/AMPK降低(P<0.05)。结论:牡荆素能够通过调控AMPK/NLRP3信号通路,抑制细胞焦亡,进而改善大鼠急性咽炎。

血清AMPK-αmRNA、Caspase-6 mRNA水平对非酒精性脂肪肝疗效的预测价值及影响因素分析

目的 分析血清腺苷酸活化蛋白激酶-αmRNA(Adenosine monophosphate activated protein kinase α,AMPK-αmRNA)、半胱氨酸天冬氨酸蛋白酶-6(Cystein-asparate protease,caspase-6) mRNA水平对非酒精性脂肪肝(Non-alcoholic fatty liver disease,NAFLD)疗效的预测价值及影响因素。方法 选取2021年10月-2023年8月聊城市人民医院感染性疾病科收治的188例NAFLD患者为研究对象,治疗6个月后以甘油三酯(TG)降低≥20%和(或)总胆固醇(TC)降低≥10%判断为治疗有效,归入有效组,否则判断为治疗无效,归入无效组。所有患者治疗前后检测血清AMPK-αmRNA、Caspase-6 mRNA水平。收集NAFLD患者一般资料,分析NAFLD疗效的影响因素。绘制受试者工作特征(Receiver operating characteristic curve,ROC)曲线分析血清AMPK-αmRNA,Caspase-6 mRNA水平对NAFLD疗效的预测价值。结果 188例NAFLD患者治疗6个月脱落6例,有效随访182例,其中治疗有效126例(69.23%),纳入有效组,治疗无效56例(30.77%),纳入无效组。与本组治疗前比较,治疗6个月后患者血清AMPK-αmRNA水平升高,Caspase-6 mRNA水平降低,差异有统计学意义(P<0.05)。与无效组比较,有效组治疗前、治疗6个月血清AMPK-αmRNA水平升高,Caspase-6 mRNA水平降低,差异有统计学意义(P<0.05)。患有糖尿病,血清TC、TG、低密度脂蛋白胆固醇(Low-density lipoprotein,LDL-C)、谷丙转氨酶(Alanime aminotransferase,ALT)、谷草转氨酶(Aspartate aminotransferase,AST),Caspase-6 mRNA水平是NAFLD疗效的独立危险因素,治疗前血清AMPK-αmRNA水平是其独立保护因素(P<0.05)。建立Logistic回归模型:logit(P)=-29.182-0.867×AMPK-αmRNA+0.890×Caspase-6 mRNA+1.956×糖尿病+1.283×TG+0.982×TC+0.703×LDL-C+0.066×ALT+0.101×AST,拟合度较好。治疗前血清AMPK-αmRNA、Caspase-6 mRNA水平及Logistic回归模型预测NAFLD疗效的曲线下面积(Area under curve,AUC)值分别为0.757、0.717、0.816,Logistic回归模型的预测价值大于AMPK-αmRNA,Caspase-6 mRNA单独评估价值(Z=2.149,P=0.032;Z=2.879,P=0.004)。结论 患者是否患有糖尿病,血清TG、TC、LDL-C、ALT、AST、AMPK-αmRNA、Caspase-6 mRNA水平是NAFLD疗效的影响因素,检测血清AMPK-αmRNA、Caspase-6 mRNA水平对NAFLD疗效具有一定预测价值。

山姜素调节cAMP/PKA/CREB信号通路促进骨质疏松性骨折大鼠骨折愈合

背景:山姜素具有抗炎、抗肿瘤、抗菌等作用,已被证实能够缓解骨质疏松症,但山姜素对骨质疏松性骨折的影响及机制仍不清楚。目的:探讨山姜素调节环磷酸腺苷/蛋白激酶A/环磷酸腺苷反应元件结合蛋白信号通路对骨质疏松性骨折大鼠的改善作用。方法:采用双侧卵巢切除手术构建骨质疏松症骨折大鼠模型,将成功造模大鼠依据随机数字表法分为山姜素低、中、高剂量组、抑制剂组和模型组,另选12只大鼠作为假手术组。骨折造模当天,山姜素低、中、高剂量组大鼠灌胃7.5,15,30 mg/kg的山姜素+腹腔注射等量的生理盐水,抑制剂组灌胃30 mg/kg的山姜素+腹腔注射5 mg/kg的H-89(通路抑制剂),模型组与假手术组给予(灌胃+腹腔注射)等量生理盐水,1次/d,连续8周。放射性检查评估大鼠骨折愈合情况并进行愈合评分;骨密度扫描仪测定骨折处骨密度;通过三点弯曲实验和压缩实验评估大鼠股骨生物力学状况;苏木精-伊红染色观察大鼠骨折处病理损伤;酶联免疫吸附(ELISA)法检测血清碱性磷酸酶、骨钙素和Ⅰ型胶原交联C-末端肽、环磷酸腺苷水平的变化;Western blot检测股骨组织中骨形态发生蛋白2和环磷酸腺苷/蛋白激酶A/环磷酸腺苷反应元件结合蛋白通路蛋白表达。结果与结论:①相较于假手术组,模型组大鼠骨折愈合评分、骨密度、最大负荷、最大应力、碱性磷酸酶、骨钙素、环磷酸腺苷水平、骨形态发生蛋白2、磷酸化蛋白激酶A/蛋白激酶A、磷酸化环磷酸腺苷反应元件结合蛋白/环磷酸腺苷反应元件结合蛋白表达下降,Ⅰ型胶原交联羧基末端肽水平增加(P<0.05);与模型组比较,山姜素各剂量组大鼠上述各项指标呈现相反的变化(P<0.05);与山姜素高剂量组比较,抑制剂组大鼠上述指标变化均被逆转(P<0.05)。②结论:山姜素可能通过激活环磷酸腺苷/蛋白激酶A/环磷酸腺苷反应元件结合蛋白信号通路加速骨质疏松症骨折大鼠的骨折愈合。