Exploring the interaction between the gut microbiota and cyclic adenosine monophosphate-protein kinase A signaling pathway:a potential therapeutic approach for neurodegenerative diseases

The interaction between the gut microbiota and cyclic adenosine monophosphate(cAMP)-protein kinase A(PKA)signaling pathway in the host's central nervous system plays a crucial role in neurological diseases and enhances communication along the gut–brain axis.The gut microbiota influences the cAMP-PKA signaling pathway through its metabolites,which activates the vagus nerve and modulates the immune and neuroendocrine systems.Conversely,alterations in the cAMP-PKA signaling pathway can affect the composition of the gut microbiota,creating a dynamic network of microbial-host interactions.This reciprocal regulation affects neurodevelopment,neurotransmitter control,and behavioral traits,thus playing a role in the modulation of neurological diseases.The coordinated activity of the gut microbiota and the cAMP-PKA signaling pathway regulates processes such as amyloid-β protein aggregation,mitochondrial dysfunction,abnormal energy metabolism,microglial activation,oxidative stress,and neurotransmitter release,which collectively influence the onset and progression of neurological diseases.This study explores the complex interplay between the gut microbiota and cAMP-PKA signaling pathway,along with its implications for potential therapeutic interventions in neurological diseases.Recent pharmacological research has shown that restoring the balance between gut flora and cAMP-PKA signaling pathway may improve outcomes in neurodegenerative diseases and emotional disorders.This can be achieved through various methods such as dietary modifications,probiotic supplements,Chinese herbal extracts,combinations of Chinese herbs,and innovative dosage forms.These findings suggest that regulating the gut microbiota and cAMP-PKA signaling pathway may provide valuable evidence for developing novel therapeutic approaches for neurodegenerative diseases.

Role of Toll-like receptor 4 and Janus kinase and signal transducer and activator of transcription signal transduction pathway in sepsis-induced brain damage

The Janus kinase and signal transducer and activator of transcription （JAK/STAT） signal transduction pathway is involved in sepsis-induced functional damage to the heart, liver, kidney, and other organs. However, the cellular and molecular mechanisms underlying sepsis-induced brain damage remain elusive. In the present study, we found severe loss of neurons in the hippocampal CA1 region in rats with sepsis-induced brain damage following intraperitoneal injection of endotoxin, The expression of toll-like receptor 4, tumor necrosis factor a, and interleukin-6 was significantly increased in brain tissues following lipopolysaccharide exposure. AG490 （JAK2 antagonist） and rapamycin （STAT3 antagonist） significantly reduced neuronal loss and suppressed the increased expression of toll-like receptor 4, tumor necrosis factor a, and interleukin-6 in the hippocampal CA1 region in sepsis-induced brain damaged rats. Overall, these data suggest that blockade of the JAK/STAT signal transduction pathway is neuroprotective in sepsis-induced brain damage via the inhibition of toll-like receptor 4, tumor necrosis factor a, and interleukin-6 exoression.

Mitogen activated protein kinase signaling pathways participate in the active principle region of Buyang Huanwu decoction-induced differentiation of bone marrow mesenchymal stem cells

Our preliminary studies confirmed that an active principle region of Buyang Huanwu decoction, comprising alkaloid, polysaccharide, aglycon, glucoside and volatile oil, can induce bone marrow mesenchymal stem cell differentiation into neurons. Mitogen-activated protein kinase signaling was identified as one of the key pathways underlying this differentiation process. The present study shows phosphorylated extracellular signal-regulated protein kinase and phosphorylated p38 protein expression was increased after differentiation. Cellular signaling pathway blocking agents, PD98059 and SB203580, inhibited extracellular signal-regulated protein kinase and p38 in mitogen-activated protein kinase signaling pathways respectively, mRNA and protein expression of the neuronal marker, neuron specific enolase, and neural stem cell marker, nestin, were decreased in bone marrow mesenchymal stem cells after treatment with the active principle region of Buyang Huanwu decoction. Experimental findings indicate that, extracellular signal-regulated protein kinase and p38 in mitogen-activated protein kinase signaling pathways participate in bone marrow mesenchymal stem cell differentiation into neuron-like cells, induced by the active principle region of Buyang Huanwu decoction.

Influence of electroacupuncture on mitogen-activated protein kinase signal transduction in a rat model of cerebral ischemia/reperfusion

Following electroacupuncture at Baihui （DU 20） and Dazhui （DU 14） in a rat model of cerebral ischemia/reperfusion, extracellular-signal-regulated kinase expression in cerebral cortex and corpus striatum, serum glutathione reductase, glutathione peroxidase activity, and serum glutathione content were elevated, and neurobehavioral scores improved. However, these effects were antagonized by mitogen-activated protein kinase inhibitor PD98059. Results indicated that electroacupuncture reversed free radical chain reactions and oxidative stress injury caused by cerebral ischemia/reperfusion, thereby providing neuroprotection. This process could correlate with the mitogen-activated protein kinase signal transduction pathway.

JAK/STAT signaling regulates tissue outgrowth and male germline stem cell fate in Drosophila

In multicellular organisms, biological activities are regulated by cell signaling. The various signal transduction path- ways regulate cell fate, proliferation, migration, and polarity. Miscoordination of the communicative signals will lead to disasters like cancer and other fatal diseases. The JAK/STAT signal transduction pathway is one of the pathways, which was first identified in vertebrates and is highly conserved throughout evolution. Studying the JAK/STAT signal transduc- tion pathway in Drosophila provides an excellent opportunity to understand the molecular mechanism of the cell regu- lation during development and tumor formation. In this review, we discuss the general overview of JAK/STAT signaling in Drosophila with respect to its functions in the eye development and stem cell fate determination.

SIGNAL MECHANISM OF INHIBITION OF BIFIDOBACTERIA ON GROWTH OF COLON CANCER

Objective: To explore the antitumor mechanisms of bifidobacteria adolescence in vivo. Methods: The content of extracellular signal regulated proteins (ERK)1/2, C-Jun N-terminal kinase (JNK), p38, c-fos and c-jun in nude mouse transplanted large bowel carcinoma was detected by using laser confocal microscopy. The expression of NF-κB was determined by immunohistochemistry. Results: After the nude mouse transplanted tumor was treated with bifidobacteria, the average fluorescent strength of ERK1/2, JNK, c-fos and c-jun was significantly lower than that in tumor control group (P<0.01). The average fluorescent strength of p38 was not obvious difference in the two groups (P>0.05). The positive cell density of NF-κB in large bowel carcinoma transplantation tumors in Bifidobacterium injection group was markedly lower than that in tumor group(P<0.01). Conclusion: bifidobacteria adolescence could markedly decrease the activity of ERK1/2 and JNK, the expression c-fos and c-jun, and the activity of NF-κB.

Functional Insights of Plant GSK3-like Kinases： Multi-Taskers in Diverse Cellular Signal Transduction Pathways

The physiological importance of GSK3-like kinases in plants emerged when the functional role of plant GSK3-like kinases represented by BIN2 was first elucidated in the brassinosteroid （BR）-regulated signal transduction pathway. While early studies focused more on understanding how GSK3-like kinases regulate BR signaling, recent studies have implicated many novel substrates of GSK3-like kinases that are involved in a variety of cellular processes as well as BR signaling. Plant GSK3-like kinases play diverse roles in physiological and developmental processes such as cell growth, root and stomatal cell development, flower development, xylem differentiation, light response, and stress responses. Here, we review the progress made in recent years in understanding the versatile functions of plant GSK3-like kinases. Based on the relationship between GSK3-like kinases and their newly identified substrates, we discuss the physiological and biochemical relevance of various cellular signaling mediated by GSK3-like kinases in plants.

Effect of cigarette smoke extract on lipopolysaccharide-activated mitogen-activated protein kinase signal transduction pathway in cultured cells

Background Lipopolysaccharide （LPS） forms outer membrane of the wall of Gram-negative cells. LPS can directly cause damage to epithelia of respiratory tract and is the major factor responsible for the chronic inflammation of respiratory passage. The mitogen-activated protein kinase （MAPK） signal transduction pathway of the airway epithelia is intimately associated with the action of LPS. The chronic inflammation of respiratory tract and smoking are interrelated and entwined in the development and progression of chronic lung diseases. This study was designed to examine the effects of cigarette smoke extract （CSE） and LPS on MAPK signal transduction pathway in order to further understand the roles CSE and LPS play in chronic lung inflammation. Methods Cultured primary human epithelial cells of airway were divided into four groups according to the stimulants used： blank control group, LPS-stimulation group, CSE-stimulation group and CSE plus LPS group. Western blotting was employed for the detection of phosphorylation level of extracellular-signal-regulated-kinase （ERK1/2）, p38 MAPK and c-Jun N-terminal kinase （JNK）. The expression of cytokines of MAPK transduction pathway （granulocyte-macrophage colony stimulating factor （GM-CSF） and mRNA of IL-8） in the primary epithelial cells of respiratory tract was also determined. Results Western blotting revealed that the phosphorylation levels of ERK1/2, p38 MAPK and JNK were low and 2 hours after the LPS stimulation, the phosphorylation of ERK1/2, p38 MAPK and JNK were all increased. There was a significant difference in the phosphorylation between the LPS-stimulation group and blank control group （P〈0.05）; no significant difference was found between CSE-stimulation group and blank control group （P〉0.05）; there was a significant difference between CSE ＋ LPS group and blank control group and between CSE ＋ LPS group and LPS group （P〈0.05）. The phosphorylation of CSE-LPS group was higher than that of blank control group but lower than that of LPS group. In blank control group, the expression of IL-8 and GM-CSF mRNA was low in the epithelial cells of airway and the release of IL-8 and GM-CSF was also at a low level. One hour after LPS stimulation, the level of IL-8 mRNA increased （P〈0.05） and reached a peak after 2 hours. On the other hand, GM-CSF mRNA level increased 2 hours after the stimulation （P〈0.05） and reached the highest level 4 hours after the stimulation. Two hours after LPS stimulation, IL-8 and GM-CSF protein level began to rise （P〈0.05）, and the level was the highest 8 hours after the stimulation （P〈0.01）. Stimulation with CSE alone had no effect on the release of IL-8 and GM-CSF and expression of IL-8 mRNA （P〉0.05）, but pre-treatment with CSE could delay the LPS-induced release of IL-8 and GM-CSF and the expression of IL-8 mRNA and its peak was lower. Conclusions LPS stimulation can significantly increase the phosphorylation of ERK1/2, p38 MAPK and JNK in the epithelial cells of airway and activate the MAPK transduction pathway, thereby can activate the downstream signal transduction pathway, and can ultimately result in the release of cytokines by the epithelial cells of airway. CSE can partially abolish the LPS-induced activation of MAPK signal transduction pathway and the expression of cytokines of the pathway, which might contribute to the development and progression of the inflammatory reactions in COPD patients.

Modified Sijunzi Granules Exhibit Hemostatic Effect by Activating Akt and Erk Signal Pathways via Regulating 5-HT and Its Receptors Levels

Objective:To investigate the hemostatic effect of modified Sijunzi Granules(MSG)in primary immune thrombocytopenia(ITP)zebrafish model and explore the potential mechanism.Methods:AB strain wild type zebrafish were treated with simvastatin(6μmol/L)for 24 h to establish the hemorrhage model(model control group).The zebrafish were treated with MSG at different doses(55.6,167,and 500μg/mL),respectively.The hemostatic effect was assessed by examining the intestinal bleeding and hemostatic rate.5-hydroxytryptamine(5-HT)content was determined using enzyme-linked immunosorbent assay(ELISA)assay.The expressions of5-HT2aR,5-HT2bR,and SERT genes were detected by quantitative real-time polymerase chain reaction(PCR).The protein expressions of protein kinase B(Akt),p-Akt,extracellular regulated protein kinases(Erk),and p-Erk were examined using Western blot analysis.Results:The intestinal bleeding rate was 37%,40%,and 80%in the55.6,167,and 500μg/mL dose of MSG,respectively,in which 55.6 and 167μg/mL MSG dose groups were associated with significantly decreased intestinal bleeding rate when compared with the model control group(70%,P<0.05).Significantly higher hemostatic rates were also observed in the 55.6μg/mL(54%)and 167μg/mL(52%)MSG dose groups(P<0.05).MSG increased the 5-HT content and mRNA expression levels of 5-HT2aR,5-HT2bR,and SERT(P<0.05).In addition,caspase3/7 activity was inhibited(P<0.05).Significant increase in p-Akt and p-Erk was also detected after treatment with MSG(P<0.05).Conclusions:MSG could reduce the incidence and severity of intestinal bleeding in zebrafish by activating MAPK/Erk and PI3K/Akt signal pathways through regulating the levels of 5-HT and its receptors,which may provide evidence for the treatment of ITP.

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.

Regulation of the EGFR pathway by visfatin and its effect on cardiac hypertrophy

Objective:To investigate the regulation of the epidermal growth factor receptor(EGFR)pathway by visfatin and its effect on cardiac hypertrophy.Methods:60 Wistar male rats were randomly divided into control group,visfatin group and visfatin+AG1478 group,with 20 rats in each group.The cardiac mass index,left ventricular mass index and cardiomyocyte volume of rats in each group were calculated.The total protein content of each group of cardiomyocytes was detected by coomassie bright blue staining,and the protein expression was detected by Western blotting.Results:Compared with the control group,the cardiac mass index,left ventricular mass index,cardiomyocyte volume,protein content,and relative expressions of ANP and BNP were significantly increased in the visfatin group(P<0.05).The relative expression levels of EGFR,p-AKT,p-ERK1/2,p-STAT3,ANP and BNP in cardiac myocytes in the visfatin group were significantly higher than those in the control group and the visfatin+AG1478 group(P<0.05).Conclusion:Visfatin induces hypertrophy in cardiomyocytes by activating the EGFR signaling pathway.

ERK信号转导途径在哮喘大鼠气道重塑中作用的初步探讨

目的:研究支气管哮喘不同时期细胞外信号调节激酶(External signal regulated kinase,ERK)的磷酸化与c-Fos表达,以探讨ERK信号转导途径在支气管哮喘气道重塑中的作用。方法:复制大鼠哮喘模型,随机分为对照组(包括4周、8周及12周对照组)、哮喘组(包括4周、8周及12周哮喘组),图像分析软件测定支气管壁厚度(Wat)和平滑肌厚度(Wam),免疫组化测定肺组织磷酸化的ERK(Phospho-ERK,P-ERK)与c-Fos表达,免疫印迹法测定磷酸化的ERK水平,直线相关分析法显示Wat和Wam与P-ERK的相关性。结果:各哮喘组Wat和Wam,P-ERK和c-Fos的平均吸光度均显著高于相应对照组(P均<0.01);各哮喘组磷酸化的ERK水平均显著高于相应对照组(其中A12也与C8组比)(P<0.01);Wat、Wam与P-ERK平均吸光度均呈显著正相关性(P<0.01)。结论:ERK磷酸化水平和c-Fos在哮喘大鼠均增加,ERK信号转导途径在支气管哮喘气道重塑中起重要作用。

蛋白激酶C和磷脂酰肌醇4,5二磷酸之间相互调节作用的研究进展

蛋白激酶C(protein kinase C,PKC)是一个多基因家族,包含多种同工酶,分布广泛且功能复杂,在许多信号转导通路发挥重要作用。磷脂酰肌醇(4,5)二磷酸(PIP2)是分布在细胞膜中的磷脂类信号分子,在细胞中的分布和含量处于动态变化中。PIP2的水解后生成DAG和IP3。DAG可以直接激活PKC,而IP3通过调节细胞内钙离子的浓度从而改变钙依赖型PKCs的活性。同时,PKC通过激活PI4K或PIP5K可以调节细胞膜PIP2水平。PKCs使离子通道蛋白发生磷酸化,改变通道蛋白与PIP2的亲和力,从而影响PIP2对离子通道的调节。该文对PKCs和PIP2在细胞信号转导过程中相互调节的相关研究进展进行综述。

针刺对大鼠局部筋膜和脊髓细胞外信号调节激酶1/2和P38丝裂酶原活化蛋白激酶信号通路的影响

目的:观察针刺捻转拉伸大鼠皮下筋膜对局部筋膜和脊髓背角细胞外信号调节激酶1/2(ERK1/2)和丝裂原活化蛋白激酶P38(P38MAPK)信号通路的影响及筋膜结缔组织的形态学变化。方法:20只SD大鼠通过随机分组,每组5只,针刺后三里组和针刺非穴位组进行手针捻转,拉伸刺激组进行拉伸刺激,采用免疫组化技术观察筋膜和脊髓组织中细胞信号蛋白的变化;利用相差显微镜观察拉伸刺激组局部皮下筋膜形态学变化。结果:组织学改变:拉伸刺激组皮下筋膜的纤维以拉伸点为中心呈向心性分布,单位面积内细胞密度增大,细胞骨架和胞核重构成"扁梭形"。细胞信号蛋白变化:针刺组筋膜结缔组织ERK1/2和P38MAPK表达与对照组相比均有增加,但以非穴组增加显著;ERK1/2与P38MAPK在脊髓中的表达位置由胞质转向胞核,ERK1/2与空白对照组相比差异没有显著性意义;P38MAPK的表达有所增加。结论:针刺对局部浅筋膜的ERK1/2和P38有上调作用,但与脊髓中的信号蛋白增加幅度并不完全一致,提示筋膜结缔组织支架可能在微观的信号转导层面对局部细胞分化与增殖具有促进作用。

ERK2和PI-3K在小柴胡汤抗大鼠肝纤维化中的表达

目的观察小柴胡汤对肝纤维化大鼠肝组织细胞外信号调节激酶2(ERK2)、磷酸肌醇-3激酶(PI-3K)表达的影响,探讨小柴胡汤治疗肝纤维化的分子机制。方法皮下注射10%四氯化碳制备大鼠肝纤维化模型,第9周开始四氯化碳给药同时给予小柴胡汤灌胃治疗6周。通过血清生化检测反映肝脏功能;HE染色法观察肝组织病理学变化;免疫组织化学方法观察肝组织α-平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)的表达,以反映肝星状细胞的活化情况;Real time RT-PCR观察ERK2、PI-3K mRNA的表达。结果与模型组相比,小柴胡汤中、高剂量组在血清学和组织学上均有明显改善,肝组织ERK2、PI-3K mRNA的表达明显减少,具有统计学意义。结论小柴胡汤抗四氯化碳诱导大鼠肝纤维化作用可能与干预Ras/ERK和PI-3K信号通路有关。

P38MAPK信号通路与uPA在卵巢癌细胞及组织中表达的相关性

背景与目的:P38丝裂原活化蛋白激酶(P38 mitogen-activated protein kinase,P38MAPK)信号通路参与多种肿瘤的发生、发展和转移过程,尿激酶型纤溶酶原激活剂(urokinase-type plasminogen activator,uPA)在肿瘤浸润和转移中发挥着重要作用。本实验研究卵巢癌组织中P38MAPK、细胞外信号调节激酶(extracellular signal-regulated kinase,ERK)、丝氨酸苏氨酸蛋白激酶(serine threonine kinase,AKT)及uPA的表达与临床病理特征的关系,并分析上述蛋白与u PA表达的相关性,探讨P38MAPK信号通路与uPA在卵巢癌细胞及组织中的表达及临床意义。方法:应用免疫组织化学法检测49例卵巢癌组织中u PA、P38MAPK、ERK和AKT蛋白的表达,采用蛋白[质]印迹法(Western blot)检测不同卵巢癌细胞系HO8910、HO-8910PM、SKOV3和CAOV3中uPA和P38MAPK蛋白的表达,使用特异性抑制剂SB203580阻断P38MAPK信号通路后检测u PA蛋白表达水平的变化。结果:uPA、P38MAPK、ERK和AKT蛋白在卵巢癌组织中的表达阳性率分别为61.22%、57.14%、53.06%和55.10%。uPA蛋白的表达与P38MAPK呈正相关(r=0.865,P=0.001),且与卵巢癌组织的临床病理分期(P=0.029)、分化(P=0.03)和转移程度(P淋巴=0.022,P大网膜=0.012)有关,而与患者的年龄(P=0.754)及组织学类型(P=0.652)无关。ERK、AKT蛋白的表达与卵巢癌淋巴结转移(PERK=0.011,PAKT=0.022)和大网膜转移(PERK=0.006,PAKT=0.000)有关,而与患者的年龄(PERK=0.000,PAKT=0.022)、组织类型(PERK=0.771,PAKT=0.245)及病理分期(PERK=1.000,PAKT=0.254)无关。卵巢癌细胞系HO-8910PM中uPA蛋白的表达水平明显高于HO8910、SKOV3和CAOV3细胞系,使用SB203580阻断P38MAPK信号通路后可降低uPA蛋白的表达,且随着SB203580浓度升高u PA蛋白表达水平逐渐降低。卵巢癌中P38MAPK及u PA蛋白的表达与卵巢癌的预后显著相关(Log-rank=3.897和11.044,P=0.048和0.001)。结论:卵巢癌组织中P38MAPK信号通路处于激活状态;P38MAPK信号通路的激活可上调u PA的表达,促进卵巢癌的恶性进展;P38MAPK信号通路和u PA可能在卵巢癌侵袭和转移的过程中发挥重要作用。P38MAPK和uPA蛋白有望成为卵巢癌预后评估的重要指标。

nm23-H_1基因对人肺癌细胞中细胞外信号调节激酶活性的影响

目的 探讨肿瘤转移抑制基因nm2 3 H1 对人高转移大细胞肺癌细胞株L9981中细胞外信号调节激酶ERK1/2活性的影响。方法 应用特异性识别总ERK1/2 ( p44 /4 2MAPkinase)和双磷酸化ERK1/2( phospho p44 /4 2MAPkinase)的抗体及蛋白印迹法 (Westernblot) ,检测L9981(缺失nm2 3 H1 基因的原代肺癌细胞株 )、L9981 nm 2 3 H1 (转染了nm 2 3 H1 基因的L9981细胞株 )、L9981 PLXSN (转染了空载体的L9981细胞株 )中总ERK1/2和磷酸化ERK1/2的水平。磷酸化ERK 1/2活性应用非放射性免疫沉淀和Westernblot法以及 p44 /4 2MAPkinase分析试剂盒予以检测。 结果 L9981 nm2 3 H1 细胞株中磷酸化ERK 1/2的水平 ,以及ERK1/2活性均显著低于L9981细胞株和L9981 PLXSN细胞株 (P <0 .0 1) ,L9981和L9981 PLXSN细胞株间磷酸化ERK 1/2水平和ERK 1/2活性比较均无显著性差异 (P >0 .0 5 )。三个细胞株间总ERK1/2水平比较均无显著性差异 (P >0 .0 5 )。结论 nm2 3 H1 基因可明显靶向地抑制人高转移肺癌细胞株L9981中ERK 1/2的转录表达和ERK 1/2的活性。推测nm2 3 H1 基因的作用机制可能与其抑制了MAPK/ERK信号传导通路有关。

Smad通路参与ERK通路诱导血管平滑肌细胞增殖的过程

目的:探讨Smad通路是否参与细胞外信号调节激酶(ERK)通路诱导血管平滑肌细胞(VSMCs)增殖的过程及其可能机制。方法:将人脐动脉平滑肌细胞(hUASMCs)分为对照组、血小板源性生长因子(PDGF)组、ERK阻断剂组和PDGF+ERK阻断剂组。用MTT法测hUASMCs的增殖活性(A值),用免疫组化法测hUASMCs内细胞核增殖抗原(PCNA)、磷酸化ERK和磷酸化Smad蛋白的表达,用RT-PCR法测hUASMCs内Smad2/3mRNA的表达。结果:PDGF组hUASMCs的增殖活性(A值)及hUASMCs内的PCNA、磷酸化ERK和磷酸化Smad2/3蛋白的表达都明显高于其它各组(P<0.01);各组hUASMCs内Smad2/3mRNA的表达没有差异。结论:Smad通路可在蛋白水平参与ERK通路诱导VSMCs的增殖过程。

阿司匹林对人胃黏膜上皮细胞生长和occludin蛋白表达的影响及其机制研究

背景:研究显示ERK信号通路激活可促进细胞生长,上调紧密连接蛋白occludin表达,而阿司匹林可抑制ERK的磷酸化激活。目的:探讨阿司匹林对人胃黏膜上皮细胞生长和occludin蛋白表达的影响及其可能机制。方法:建立人胃黏膜上皮细胞株GES-1单层细胞模型,MTT法检测阿司匹林(5～20 mmol/L)和MEK抑制剂U0126(10～40μmol/L)对GES-1细胞的生长抑制作用。将GES-1细胞分为阿司匹林(8.78 mmol/L)组、U0126(14.91μmol/L)组、联合组(U0126+阿司匹林)和阴性对照组,倒置相差显微镜下观察细胞形态学变化,流式细胞术检测细胞凋亡情况,蛋白质印迹法检测p-ERK1/2、occludin蛋白表达。结果:阿司匹林和U0126均能剂量依赖性地抑制GES-1细胞生长,联合组细胞凋亡较两药单用更为显著,贴壁细胞数量减少更为明显,细胞变圆、悬浮。阿司匹林组、U0126组和联合组p-ERK1/2、occludin蛋白表达量均显著低于阴性对照组,U0126组和联合组降低更为明显。结论:阿司匹林可抑制人胃黏膜上皮细胞生长,下调occludin蛋白表达,其机制至少部分与抑制ERK信号通路激活有关。

ERK1/2通路在4-AP诱导大鼠肺动脉收缩中的作用

目的探讨细胞外信号调节激酶-1/2(ERK1/2)通路在4-氨基吡啶(4-aminopyridione,4-AP)阻断正常大鼠肺动脉平滑肌细胞(PASMCs)膜上电压依赖性钾通道(KV)所引起的肺动脉收缩中的作用。方法取正常鼠肺动脉制作肺动脉环,分别加入4-AP(KV通道阻断剂),PD98059/U0126+4-AP,比较肺动脉收缩的变化。同时培养肺动脉平滑肌细胞进行Western blot分析4-AP对ERK1/2的影响。结果①在血管环试验中,4-AP引起的肺动脉收缩有浓度依赖性;加入20mmol.L-1PD98059或2μmol.L-1U0126可以抑制4-AP引起的肺动脉收缩。②4-AP可刺激PASMCs ERK1/2蛋白磷酸化;③U0126可抑制4-AP引起的ERK1/2蛋白磷酸化。结论ERK1/2通路参与4-AP阻断正常大鼠肺动脉平滑肌细胞膜上电压依赖性钾通道(KV)引起肺动脉收缩。