Osteopontin promotes gastric cancer progression via phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway

BACKGROUND Gastric cancer(GC)is one of the most common malignant tumors.Osteopontin(OPN)is thought to be closely related to the occurrence,metastasis and prognosis of many types of tumors.AIM To investigate the effects of OPN on the proliferation,invasion and migration of GC cells and its possible mechanism.METHODS The mRNA and protein expression of OPN in the GC cells were analyzed by realtime quantitative-reverse transcription polymerase chain reaction and western blotting,and observe the effect of varying degree expression OPN on the proliferation and other behaviors of GC.Next,the effects of OPN knockdown on GC cells migration and invasion were examined.The short hairpin RNA(shRNA)and negative control shRNA targeting OPN-shRNA were transfected into the cells according to the manufacturer’s instructions.Non transfected cells were classified as control in the identical transfecting process.24 h after RNA transfection cell proliferation activity was detected by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-diphenytetrazoliumromide assay,and cell invasiveness and migration were detected by Trans well assay.Meanwhile,the expression of protein kinase B(AKT),matrix metalloproteinase 2(MMP-2)and vascular endothelial growth factor(VEGF)in the human GC cell lines was detected by reverse transcription polymerase chain reaction and western blotting.RESULTS The results of this study revealed that OPN mRNA and protein expression levels were highly expressed in SGC-7901 cells.OPN knockdown by specific shRNA noticeably reduced the capabilities of proliferation,invasion and migration of SGC-7901 cells.Moreover,in the experiments of investigating the underlying mechanism,results showed that OPN knockdown could down-regulated the expression of MMP-2 and VEGF,it also decreased the phosphorylation of AKT.Meanwhile,the protein expression levels of MMP-2,VEGF and phosphorylated AKT was noticeable lower than that in control group in the GC cells after they were added to phosphatidylinositol-3-kinase(PI3K)inhibitor(LY294002).CONCLUSION These results suggested that OPN though PI3K/AKT/mammalian target of rapamycin signal pathway to upregulate MMP-2 and VEGF expression,which contribute SGC-7901 cells to proliferation,invasion and migration.Thus,our results demonstrate that OPN may serve as a novel prognostic biomarkers as well as a potential therapeutic targets for GC.

Protective effects of panax notoginseng saponin on dextran sulfate sodium-induced colitis in rats through phosphoinositide-3-kinase protein kinase B signaling pathway inhibition

BACKGROUND Intestinal inflammation is a common digestive tract disease, which is usually treated with hormone medicines. Hormone medicines are effective to some extent, but long-term use of them may bring about many complications.AIM To explore the protective effects of panax notoginseng saponin(PNS) against dextran sulfate sodium(DSS)-induced intestinal inflammatory injury through phosphoinositide-3-kinase protein kinase B(PI3K/AKT) signaling pathway inhibition in rats.METHODS Colitis rat models were generated via DSS induction, and rats were divided into control(no modeling), DSS, DSS + PNS 50 mg/k, and DSS + PNS 100 mg/kg groups. Then, the intestinal injury, oxidative stress parameters, inflammatory indices, tight junction proteins, apoptosis, macrophage polarization, and TLR4/AKT signaling pathway in colon tissues from rats in each of the groups were detected. The PI3 K/AKT signaling pathway in the colon tissue of rats was blocked using the PI3K/AKT signaling pathway inhibitor, LY294002.RESULTS Compared with rats in the control group, rats in the DSS group showed significantly shortened colon lengths, and significantly increased disease activity indices, oxidative stress reactions and inflammatory indices, as well as significantly decreased expression of tight junction-associated proteins. In addition, the DSS group showed significantly increased apoptotic cell numbers,and showed significantly increased M1 macrophages in spleen and colon tissues.They also showed significantly decreased M2 macrophages in colon tissues, as well as activation of the PI3K/AKT signaling pathway(all P < 0.05). Compared with rats in the DSS group, rats in the DSS + PNS group showed significantly lengthened colon lengths, decreased disease activity indices, and significantly alleviated oxidative stress reactions and inflammatory responses. In addition, this group showed significantly increased expression of tight junction-associated proteins, significantly decreased apoptotic cell numbers, and significantly decreased M1 macrophages in spleen and colon tissues. This group further showed significantly increased M2 macrophages in colon tissues, and significantly suppressed activation of the PI3K/AKT signaling pathway, as well as a dose dependency(all P < 0.05). When the PI3K/AKT signaling pathway was inhibited, the apoptosis rate of colon tissue cells in the DSS + LY294002 group was significantly lower than that of the DSS group(P < 0.05).CONCLUSION PNS can protect rats against DSS-induced intestinal inflammatory injury by inhibiting the PI3K/AKT signaling pathway, and therefore may be potentially used in the future as a drug for colitis.

Telencephalin protects PAJU cells from amyloid beta protein-induced apoptosis by activating the ezrin/radixin/moesin protein family/phosphatidylinositol-3-kinase/protein kinase B pathway

Telencephalin is a neural glycoprotein that reduces apoptosis induced by amyloid beta protein in the human neural tumor cell line PAJU. In this study, we examined the role of the ezrin/radixin/moesin protein family/phosphatidylinositol-3-kinase/protein kinase B pathway in this process. Western blot analysis demonstrated that telencephalin, phosphorylated ezrin/radixin/moesin and phosphatidylinositol-3-kinase/protein kinase B were not expressed in PAJU cells transfected with empty plasmid, while they were expressed in PAJU cells transfected with a telencephalin expression plasmid. After treatment with 1.0 nM amyloid beta protein 42, expression of telencephalin and phosphorylated phosphatidylinositol-3-kinase/protein kinase B in the transfected cells gradually diminished, while levels of phosphorylated ezrin/radixin/moesin increased. In addition, the high levels of telencephalin, phosphorylated ezrin/radixin/moesin and phosphatidylinositol-3-kinase/protein kinase B expression in PAJU cells transfected with a telencephalin expression plasmid could be suppressed by the phosphatidylinositol-3-kinase inhibitor LY294002. These findings indicate that telencephalin activates the ezrin/radixin/moesin family/phosphatidylinositol-3-kinase/protein kinase B pathway and protects PAJU cells from amyloid beta protein-induced apoptosis.

Micro RNA-21 promotes phosphatase gene and protein kinase B/phosphatidylinositol 3-kinase expression in colorectal cancer

AIM: To explore the regulatory mechanism of the target gene of micro RNA-21(mi R-21), phosphatase gene(p TEN), and its downstream proteins, protein kinase B(AKT) and phosphatidylinositol 3-kinase(p I3K), in colorectal cancer(CRC) cells. METHODS: Quantitative real-time p CR(q RT-p CR) and Western blot were used to detect the expression levels of mi R-21 and p TEN in HCT116, HT29, Colo32 and SW480 CRC cell lines. Also, the expression levels of p TEN m RNA and its downstream proteins AKT and p I3 K in HCT116 cells after downregulating mi R-21 were investigated. RESULTS: Comparing the mi R-21 expression in CRC cells, the expression levels of mi R-21 were highest in HCT116 cells, and the expression levels of mi R-21 were lowest in SW480 cells. In comparing mi R-21 and p TEN expression in CRC cells, we found that the protein expression levels of mi R-21 and p TEN were inversely correlated(p < 0.05); when mi R-21 expression was reduced, m RNA expression levels of p TEN did not significantly change(p > 0.05), but the expression levels of its protein significantly increased(p < 0.05). In comparing the levels of p TEN protein and downstream AKT and p I3 K in HCT116 cells after downregulation of mi R-21 expression, the levels of AKT and p I3 K protein expression significantly decreased(p < 0.05). CONCLUSION: p TEN is one of the direct target genesof mi R-21. Thus, phosphatase gene and its downstream AKT and p I3 K expression levels can be regulated by regulating the expression levels of mi R-21, which in turn regulates the development of CRC.

Mechanism of stilbene glycosides on apoptosis of SH-SY5Y cells via regulating PI3K/AKT signaling pathway

Objective:To investigate the effects of stilbene glycoside(TSG)on okadaic acid-induced apoptosis in human neuroblastoma cells(SH-SY5Y)via the PI3K/AKT pathway.Methods:The optimal concentration of OA was screened by CCK-8 assay,and SH-SY5Y cells were divided into control group,model group,TSG group,LY294002 group and LY294002+TSG group.The proliferation and apoptosis in each group were detected by CCK-8 and TUNEL assays;Western blotting method and real-time fluorescence quantitative polymerase chain reaction was used to detect the expression of PI3K,P-PI3K(Y607),AKT,P-AKT(Ser473),Bcl-2 and Bax proteins.The relative protein expression was represented by P-PI3K(Y607)/PI3K,P-AKT(Ser473)/AKT and Bcl-2/Bax gray ratio.Results:CCK-8 screened the optimal concentration of OA as 40 nmol/L.Compared with the control group,the model group increased relative cell viability,decreased apoptosis rate,the pathway and apoptotic proteins expression levels of P-PI3K(Y607)/PI3K,P-AKT(Ser473)/AKT and Bcl-2/Bax were decreased,and the mRNA expression levels of PI3K,AKT and Bcl-2 were decreased.Bax mRNA expression level increased(P<0.05);Compared with model group,TSG group increased relative cell viability,decreased apoptosis rate,increased protein expression levels of P-PI3K(Y607)/PI3K,P-AKT(Ser473)/AKT,Bcl-2/Bax,and increased mRNA expression levels of PI3K,AKT,and Bcl-2.Bax mRNA expression decreased(P<0.05),LY294002 group decreased relative cell viability,increased apoptosis rate,P-PI3K(Y607)/PI3K protein expression levels were significantly decreased(P<0.05),P-AKT(Ser473)/AKT and Bcl-2/Bax protein expression levels were significantly decreased,but there was no statistical significance,PI3K,AKT and Bcl-2 mRNA expression levels were decreased,and Bax mRNA expression levels were increased(all P<0.05);Compared with LY294002 group,LY294002+TSG group increased relative cell viability,decreased apoptosis rate,and the protein expression levels of P-PI3K(Y607)/PI3K,P-AKT(Ser473)/AKT and Bcl-2/Bax were increased.The mRNA expression levels of PI3K,AKT,Bcl-2 were increased,Bax was decreased(all P<0.05).Conclusion:Stilbene glycoside may alleviate okadaic acid-induced apoptosis in SH-SY5Y cells by interfering with the PI3K/AKT signaling pathway,which in turn regulates the expression of apoptotic factors such as Bcl-2 and Bax.

Expression of phosphatidylinositol-3 kinase and effects of inhibitor Wortmannin on expression of tumor necrosis factor-α in severe acute pancreatitis associated with acute lung injury

BACKGROUND: Acute lung injury(ALI) is a common and serious complication of severe acute pancreatitis(SAP). The study aimed to investigate the protective effect and mechanism of phosphatidylinositol-3 kinase(PI3K) inhibitor Wortmannin in SAP associated with ALI.METHODS: Ninety rats were randomly divided into three groups: sham operation(SO) group(n=30), SAP group(n=30), and SAP+Wortmannin(SAP+W) group(n=30). SAP model was induced by retrograde injection of 4% sodium taurocholate into the biliopancreatic duct of rats. The rate of lung water content, myeloperoxidase(MPO), matrix metalloproteinase 9(MMP-9), protein kinase B(PKB), abdphosphorylation of protein kinase B(P-PKB) activity in the lung tissue were evaluated.RESULTS: In the SAP group, the p-PKB expression in the lung tissue began to rise at 3 hours after modeling, and peaked at 12 hours(P<0.05); the rate of lung water content, MPO and TNF-α activity were also gradually increased, and the degree of lung lesion gradually increased(P<0.05). In the SAP+Wortmannin group, the p-PKB expression in the lung tissue began to rise at 3 hours after modeling, and peaked at 12 hours; it was higher than that in the SO group(P<0.05), but significantly lower than that in the SAP group(P<0.05). The rest indicators in the SAP+Wortmannin group were also significantly decreased as compared with the SAP group(P<0.05).CONCLUSIONS: The expression of phosphatidylinositol-3 kinase/protein kinase B was elevated in severe pancreatitis rats with lung injury. This suggested that PI3 K signal transduction pathway is involved in the control and release of proinfl ammatory cytokines TNF-α, which may play an important role in the pathogenesis of severe acute pancreatitis associated with lung injury. This finding indicated that Wortmannin can block the PI3 K signal transduction pathway, and inhibit the release of infl ammatory factor TNF-α.

Multiple implications of 3-phosphoinositide-dependent protein kinase 1 in human cancer

3-phosphoinositide-dependent protein kinase-1(PDK1) is a central mediator of cellular signaling between phosphoinositide-3 kinase and various intracellular serine/threonine kinases,including protein kinase B,p70 ribosomal S6 kinase,serum and glucocorticoid-inducible kinase,and protein kinase C.PDK1 activates members of the AGC family of protein kinases by phosphorylating serine/threonine residues in the activation loop.Here,we review the regulatory mechanisms of PDK1 and its roles in cancer.PDK1 is activated by autophosphorylation in the activation loop and other serine residues,as well as by phosphorylation of Tyr-9 and Tyr-373/376.Src appears to recognize PDK1 following tyrosine phosphorylation.The role of heat shock protein 90 in regulating PDK1 stability and PDK1-Src complex formation are also discussed.Furthermore,we summarize the subcellular distribution of PDK1.Finally,an important role for PDK1 in cancer chemotherapy is proposed.In conclusion,a better understanding of its molecular regulatory mechanisms in various signaling pathways will help to explain how PDK1 acts as an oncogenic kinase in various cancers,and will contribute to the development of novel cancer chemotherapies.

Anti-diabetic potential of apigenin,luteolin,and baicalein via partially activating PI3K/Akt/GLUT-4 signaling pathways in insulin-resistant HepG2 cells

Dietary flavonoids are abundant in natural plants and possess multiple pharmacological and nutritional activities.In this study,apigenin,luteolin,and baicalein were chosen to evaluate their anti-diabetic effect in high-glucose and dexamethasone induced insulin-resistant(IR)HepG2 cells.All flavonoids improves the glucose consumption and glycogen synthesis abilities in IR-HepG2 cells via activating glucose transporter protein 4(GLUT4)and phosphor-glycogen synthase kinase(GSK-3β).These fl avonoids signifi cantly inhibited the production of reactive oxygen species(ROS)and advanced glycation end-products(AGEs),which were closely related to the suppression of the phosphorylation form of NF-κB and P65.The expression levels of insulin receptor substrate-1(IRS-1),insulin receptor substrate-2(IRS-2)and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)pathway in IR-HepG2 cells were all partially activated by the fl avonoids,with variable effects.Furthermore,the intracellular metabolic conditions of the fl avonoids were also evaluated.

黄芪阳和汤调控PI3K/AKT/NF-κB信号通路促进糖尿病足溃疡大鼠创面愈合

目的基于磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(AKT)/核因子-κB(NF-κB)信号通路探究黄芪阳和汤对糖尿病足溃疡(DFU)大鼠创面愈合的影响。方法构建DFU大鼠模型,将建模成功的48只大鼠随机分为模型组,黄芪阳和汤低(8.5 g/kg)、高(17 g/kg)剂量组,黄芪阳和汤高剂量(17 g/kg)+LY294002(PI3K/AKT通路抑制剂,0.3 mg/kg)组;每组12只;另取12只大鼠为对照组。各组大鼠给予对应药物干预,连续4周。第14、28天给药后,观察大鼠一般状态及创面变化,计算创面愈合率,检测大鼠空腹血糖(FBG)水平和大鼠创面周围组织经皮氧分压(TcpO2);酶联免疫吸附试验检测大鼠血清血管内皮生长因子(VEGF)、缺氧诱导因子-1α(HIF-1α)、C反应蛋白(CRP)、白细胞介素(IL)-6水平;苏木素-伊红染色观察大鼠创面组织病理学变化;免疫组织化学染色测定大鼠创面组织微血管密度;蛋白免疫印迹法检测大鼠创面组织中PI3K、磷酸化PI3K(p-PI3K)、AKT、磷酸化AKT(p-AKT)、NF-κB p65、磷酸化NF-κB p65(p-NF-κB p65)、NF-κB抑制蛋白α(IκB-α)蛋白表达。结果对照组大鼠毛色光滑,饮食、饮水、排泄均正常,较活跃,创面愈合快,创面组织炎症反应较轻,新生血管较多,肉芽组织中成纤维细胞及胶原基质丰富;模型组大鼠毛色暗淡无光泽,活动减少,且出现多饮、多食、多尿症状,创面颜色较深,且周围组织出现水肿、溃疡,创面组织可见大量炎性细胞浸润,伴组织坏死、渗出,新生血管及成纤维细胞较少,创面愈合率、创面周围组织TcpO2、血清VEGF、HIF-1α、创面组织微血管密度、p-PI3K、p-AKT、IκB-α蛋白表达水平降低,FBG、血清CRP、IL-6、创面组织p-NF-κB p65蛋白表达升高(P<0.05);与模型组相比,黄芪阳和汤低、高剂量组大鼠状态逐渐改善,创面组织病变程度依次减轻,创面愈合率、创面周围组织TcpO2、血清VEGF、HIF-1α、创面组织微血管密度、p-PI3K、p-AKT、IκB-α蛋白表达水平依次升高,FBG、血清CRP、IL-6、创面组织p-NF-κB p65蛋白表达依次降低(P<0.05);LY294002能部分逆转高剂量黄芪阳和汤对DFU大鼠的治疗作用(P<0.05)。结论黄芪阳和汤能调控PI3K/AKT/NF-κB信号通路,抑制DFU大鼠炎症反应,促进血管新生,从而促进创面愈合。

Bornyl acetate extracted from Sharen(Fructus Amomi)inhibits proliferation,invasion and induces apoptosis by suppressing phosphatidylinositol-3-kinase/protein kinase B signaling in colorectal cancer

OBJECTIVE:To investigate the antitumor effects of bornyl acetate(BA)isolated from Sharen(Fructus Amomi)in colorectal cancer(CRC)and the underlying mechanisms.METHODS:SW480 and HT29 cells were treated with increasing doses of BA in order to determine its antitumor effects in vitro.Cell viability,colony formation,cell cycle,and apoptosis as well as migration and invasion were assessed using various assays.In addition,the in vivo antitumor effects of BA were assessed using a xenograft mouse model.We then assessed the mechanism of action of BA by conducting pathway activator-mediated rescue experiments and assessed the protein levels by Western blot analysis.RESULTS:BA showed anti-CRC tumor activities in vitro by suppressing cell proliferation and colony formation,inducing apoptosis,blocking cell cycle,and inhibiting migration and invasion.These effects were mediated via suppression of the phosphatidylinositol-3-kinase/protein kinase B(PI3K/AKT)pathway.In the tumor xenograft experiment,BA was found to repress tumor growth in vivo with low toxicity.CONCLUSIONS:The results demonstrated that BA exerts antitumor effects by suppressing the PI3K/AKT pathway,with low toxicity.Thus,BA might be a potential novel therapeutic agent for CRC.

白芍总苷调节磷脂酰肌醇3-激酶/蛋白激酶B信号通路对大鼠原发性痛经的改善作用实验研究

目的:探讨白芍总苷(TGP)调节磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(Akt)信号通路对大鼠原发性痛经(PDM)的改善作用。方法:将雌性SD大鼠采用随机数字表法分为正常对照组(Nor组)、PDM模型组(PDM组)、低剂量TGP组(TGP-L组)、高剂量TGP组(TGP-H组)和高剂量TGP+PI3K激活剂740Y-P组(TGP-H+740Y-P组),每组12只。除Nor组外,其余各组大鼠采用苯甲酸雌二醇联合缩宫素制备大鼠PDM模型,并分别用50、100 mg/kg TGP干预TGP-L组、TGP-H组大鼠,TGP-H+740Y-P组大鼠另需10 mg/kg 740Y-P干预。末次给药后观察大鼠的扭体反应,记录扭体次数和潜伏期,行扭体反应评分。HE染色观察大鼠子宫组织的病理学变化,行病理学评分。ELISA法检测大鼠子宫组织前列腺素F2α(PGF2α)、前列腺素E2(PGE2)水平以及血清β-内啡肽(β-EP)水平。免疫印迹法测量子宫组织PI3K、Akt表达及其磷酸化水平。结果:与Nor组比较,PDM组子宫病理损伤严重,子宫组织病理学评分、PGF2α以及p-PI3K、p-Akt水平升高,子宫组织PGE2及血清β-EP水平降低(均P<0.05)。与PDM组比较,TGP-L组、TGP-H组大鼠扭体反应潜伏期延长,扭体反应次数减少,扭体反应评分降低,子宫组织病理损伤减轻,子宫组织病理学评分、PGF2α以及p-PI3K、p-Akt水平降低,子宫组织PGE2及血清β-EP水平升高(均P<0.05)。高剂量TGP对大鼠PDM的改善作用更显著,而740Y-P减弱了TGP对大鼠PDM的改善作用。结论:TGP可能通过抑制PI3K/Akt信号通路改善大鼠PDM。

基于UBA2/PTEN/PI3K/Akt通路探讨蔓荆子黄素对结直肠癌细胞增殖、迁移和侵袭的影响

目的 基于泛素样修饰激活酶2(UBA2)/磷酸酶及张力蛋白同源物(PTEN)/磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(Akt)通路探究蔓荆子黄素对结直肠癌SW480细胞增殖、迁移和侵袭的影响。方法 取对数生长期的SW480细胞,对照组细胞常规培养,蔓荆子黄素组细胞加入10μmol/L蔓荆子黄素培养,UBA2抑制剂组细胞加入0.5μmol/L UBA2抑制剂培养,蔓荆子黄素+UBA2抑制剂组细胞加入10μmol/L蔓荆子黄素和0.5μmol/L UBA2抑制剂共培养。CCK-8实验检测细胞增殖情况,克隆形成实验观察细胞的单克隆形成能力,划痕实验观察细胞的迁移能力,Transwell实验观察细胞的侵袭能力,Western blot法检测细胞中UBA2/PTEN/PI3K/Akt通路相关蛋白表达情况。结果 CCK-8实验和克隆形成实验显示,UBA2抑制剂组和蔓荆子黄素+UBA2抑制剂组培养72 h后的细胞增殖吸光度OD值明显低于蔓荆子黄素组(P均<0.05),细胞克隆形成数量均明显少于蔓荆子黄素组(P均<0.05),UBA2抑制剂组和蔓荆子黄素+UBA2抑制剂组培养不同时间的细胞增殖吸光度OD值和细胞克隆形成数量比较差异均无统计学意义(P均>0.05)。划痕实验和Transwell实验显示,UBA2抑制剂组和蔓荆子黄素+UBA2抑制剂组划痕间距均明显宽于蔓荆子黄素组(P均<0.05),穿膜细胞数量均明显少于蔓荆子黄素组(P均<0.05),UBA2抑制剂组和蔓荆子黄素+UBA2抑制剂组比较差异均无统计学意义(P均>0.05)。蔓荆子黄素组、UBA2抑制剂组和蔓荆子黄素+UBA2抑制剂组细胞中PTEN蛋白相对表达量均明显高于对照组(P均<0.05),UBA2、p-PI3K、p-Akt蛋白相对表达量均明显低于对照组(P均<0.05);UBA2抑制剂组和蔓荆子黄素+UBA2抑制剂组细胞中PTEN蛋白相对表达量均明显高于蔓荆子黄素组(P均<0.05),UBA2、p-PI3K、p-Akt蛋白相对表达量均明显低于蔓荆子黄素组(P均<0.05),UBA2抑制剂组和蔓荆子黄素+UBA2抑制剂组UBA2、PTEN、p-PI3K、p-Akt蛋白相对表达量比较差异均无统计学意义(P均>0.05)。结论 蔓荆子黄素可能通过抑制UBA2/PTEN/PI3K/Akt信号通路发挥抗结直肠癌SW480细胞增殖、迁移和侵袭的能力。

薯蓣皂苷经PI3K/AKT通路对肝癌Bel-7402细胞增殖和凋亡的影响

目的分析薯蓣皂苷对肝癌Bel-7402细胞增殖和凋亡的影响并探讨其机制。方法肝癌Bel-7402细胞分为空白组和薯蓣皂苷低、中、高剂量组(给予1、2、8μmol/L的薯蓣皂苷)及薯蓣皂苷+抑制剂组(给予8μmol/L的薯蓣皂苷+10μmol/L的磷脂酰肌醇3激酶/蛋白激酶B(PI3K/AKT)信号通路抑制剂LY294002),于处理后12、24、36、48及72 h时采用四甲基偶氮唑盐(MTT)比色法测定细胞活力,于24 h时采用流式细胞术检测细胞凋亡情况、采用蛋白免疫印迹法(Western blot)检测p-PI3K和p-AKT的表达。结果与空白组相比较,薯蓣皂苷低、中、高剂量组细胞活力及p-PI3K、p-AKT表达均下降,凋亡率升高(P<0.05),且各剂量组间两两比较,上述指标水平差异均有统计学意义(P<0.05);与薯蓣皂苷高剂量组比较,薯蓣皂苷+抑制剂组细胞活力及p-PI3K、p-AKT表达下降,凋亡率升高(P<0.05)。结论薯蓣皂苷可能通过抑制PI3K/AKT通路抑制肝癌Bel-7402细胞增殖,诱导Bel-7402细胞凋亡。

miR-19b对冠心病大鼠血管内皮细胞损伤的影响及PTEN/PI3K/AKT信号通路的作用

目的探讨微小RNA(miR)-19b对冠心病大鼠血管内皮细胞损伤的影响及磷酸酶及张力蛋白同源物/磷脂酰肌醇3-激酶/蛋白激酶B(PTEN/PI3K/AKT)信号通路的作用。方法选取72只大鼠随机分为正常组、模型组、模拟对照物(NC)组、miR-19b组、miR-19b+质粒互补DNA(pcDNA)3.1组、miR-19b+PTEN组。采用高脂饲料+垂体后叶素建立冠心病模型,尾静脉注射miR-19b mimic、pcDNA3.1-PTEN慢病毒液构建miR-19b、PTEN过表达大鼠。采用荧光定量聚合酶链反应检测冠状动脉组织miR-19b和PTEN信使RNA(mRNA)水平,测定大鼠心功能,观察大鼠冠状动脉病理变化,检测心肌组织细胞凋亡情况、血管内皮功能、冠状动脉中PTEN/PI3K/AKT信号通路、含半胱氨酸的天冬氨酸蛋白水解酶(cleaved Caspase)-3、cleaved Caspase-9水平。分离培养冠心病大鼠冠状动脉内皮细胞,根据转染方式分为野生型质粒(WT)+NC组、WT+miR-19b mimic组、突变型质粒(MUT)+NC组、MUT+miR-19b mimic组,采用双荧光素酶报告基因实验验证miR-19b与PTEN的靶向关系。将冠心病大鼠冠状动脉内皮细胞分为正常细胞组、NC细胞组和miR-19b细胞组,检测PTEN mRNA和PTEN蛋白水平。结果miR-19b组左心室射血分数(LVEF)、miR-19b、血清血管内皮生长因子(VEGF)、一氧化氮(NO)、磷酸化磷脂酰肌醇-3激酶(p-PI3K)/PI3K蛋白、磷酸化蛋白激酶B(p-AKT)/AKT蛋白水平高于模型组,左心室收缩末期容积(LVESV)、舒张末期容积(LVEDV)、细胞凋亡率、cleaved Caspase-3和cleaved Caspase-9、PTEN mRNA、内皮素-1(ET-1)、PTEN蛋白水平低于模型组,差异均有统计学意义(P<0.05)。miR-19b+PTEN组LVESV、LVEDV、细胞凋亡率、PTEN mRNA、cleaved Caspase-3、cleaved Caspase-9、ET-1、VEGF、PTEN蛋白水平高于miR-19b组,LVEF、NO、p-PI3K/PI3K蛋白和p-AKT/AKT蛋白水平低于miR-19b组,差异均有统计学意义(P<0.05)。模型组LVEF、miR-19b、VEGF、NO、p-PI3K/PI3K蛋白、p-AKT/AKT蛋白水平低于正常组,LVESV和LVEDV、细胞凋亡率、PTEN mRNA、cleaved Caspase-3、cleaved Caspase-9、ET-1、PTEN蛋白水平高于正常组,差异均有统计学意义(P<0.05)。与正常组比较,模型组大鼠冠状动脉内皮细胞排列紊乱,并伴有明显的水肿。与模型组比较,miR-19b组冠状动脉组织病理损伤明显减轻。WT+miR-19b mimic组细胞中荧光素酶相对活性低于WT+NC组、MUT+NC组、MUT+miR-19b mimic组,差异均有统计学意义(P<0.05)。miR-19b mimic细胞组PTEN mRNA和PTEN蛋白水平低于正常细胞组,差异均有统计学意义(P<0.05)。结论miR-19b靶向抑制PTEN,激活PI3K/AKT信号通路,保护冠心病大鼠心功能和血管内皮功能,减少心肌细胞凋亡。

黄芩素调节PI3K/Akt/NF-κB信号通路及对细菌性脑膜炎大鼠血脑屏障的影响

目的:探讨黄芩素调控磷脂酰肌醇3激酶(PI3K)/蛋白激酶B(Akt)/核因子κB(NF-κB)信号通路对细菌性脑膜炎(BM)大鼠血脑屏障的影响。方法:制备大鼠BM模型,将大鼠分为对照组、模型组、黄芩素组(腹腔注射30 mg/kg黄芩素)、黄芩素+抑制剂组(腹腔注射30 mg/kg黄芩素+7.5 mg/kg LY294002),对大鼠进行Loeffler神经行为评分,H-E染色观察大鼠脑组织病理学变化,伊文思蓝染色检测血脑屏障通透性,分别检测脑脊液IL-1β、IL-6水平及白细胞计数(WBC)、脑组织含水量,水通道蛋白4(AQP4)、闭锁蛋白-5(claudin-5)、PI3K/Akt/NF-κB通路相关蛋白表达。结果:对照组大鼠脑组织结构正常,细胞排列整齐,模型组大鼠脑组织细胞排列紊乱,大量炎症细胞浸润。与对照组比较,模型组Loeffler评分及脑组织AQP4、claudin-5、p-PI3K、p-Akt表达水平显著降低,脑脊液IL-1β、IL-6水平及WBC、脑组织EB含量及含水量、p-NF-κB p65表达水平显著升高;黄芩素组较模型组病理损伤减轻,炎症细胞减少。与模型组比较,黄芩素组Loeffler评分及脑组织AQP4、claudin-5、p-PI3K、p-Akt表达水平显著升高,脑脊液IL-1β、IL-6水平及WBC、脑组织EB含量及含水量、p-NF-κB p65表达水平显著降低;LY294002可部分逆转黄芩素对BM大鼠血脑屏障通透性的改善作用。结论:黄芩素可改善BM大鼠脑水肿及血脑屏障通透性,可能与调控PI3K/Akt/NF-κB信号通路有关。

茯苓酸调节PI3K/AKT/NF-κB信号通路对大鼠幽门螺旋杆菌相关性胃炎的治疗作用

目的 探讨茯苓酸(PA)对大鼠幽门螺旋杆菌(Hp)相关性胃炎的治疗效果及作用机制。方法 建立Hp相关性胃炎大鼠模型;所有大鼠分为对照组(CT组)、模型组(M组)、PA低剂量组(PA L组)和PA高剂量组(PA H组)、PA H+磷脂酰肌醇3-激酶(PI3K)激活剂(740 Y-P)组;评估各组大鼠胃黏膜损伤指数(UI),透射电子显微镜观察胃黏膜细胞形态学,HE染色评价胃黏膜病理学特征,ELISA检测胃组织白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、IL-10、诱导型一氧化氮合酶(iNOS)、超氧化物歧化酶(SOD)的水平,Western blot法检测PI3K、磷酸化-PI3K(p-PI3K)、蛋白激酶B(AKT)、p-AKT、核因子(NF)-κB p65、p-NF-κB p65蛋白表达。结果 与CT组比较,M组大鼠胃黏膜糜烂,上皮水肿、充血、溃疡严重,上皮细胞固缩,炎性细胞浸润,UI、IL-6、TNF-α、iNOS以及p-PI3K/PI3K、p-AKT/AKT、p-NF-κB p65/NF-κB p65蛋白表达水平升高,IL-10和SOD水平降低(P<0.05);与M组比较,PA L组、PA H组大鼠胃黏膜损伤改善,炎性细胞浸润减少,UI、IL-6、TNF-α、iNOS以及p-PI3K/PI3K、p-AKT/AKT、p-NF-κB p65/NF-κB p65蛋白表达水平降低,IL-10和SOD水平升高(P<0.05);与PA H组比较,PA H+740 Y-P组大鼠胃黏膜病理损伤加重,上皮细胞固缩,UI、IL-6、TNF-α、iNOS以及p-PI3K/PI3K、p-AKT/AKT、p-NF-κB p65/NF-κB p65蛋白表达水平升高,IL-10和SOD水平降低(P<0.05)。结论 PA可能通过抑制PI3K/AKT/NF-κB信号通路发挥对大鼠Hp相关性胃炎的治疗作用。

肠病药方调控PI3K/AKT/NF-κB信号通路改善溃疡性结肠炎的研究

目的探讨肠病药方调控磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(AKT)/核因子kappa B(NF-κB)信号通路对抗溃疡性结肠炎(UC)的作用机制。方法42只C57BL/6小鼠随机分为正常对照组(n=6,Control组,自由饮去离子水)、模型组(n=12,DSS组)、美沙拉嗪组(n=12,MES组)及肠病药方组(n=12,CBD组),后3组小鼠自由饮用3%葡聚糖硫酸钠(DSS)溶液7 d诱导UC模型,后两组同期灌胃美沙拉嗪或肠病药方,前两组灌胃等体积去离子水;观察实验期间小鼠体质量改变,评测小鼠疾病活动指数(DAI);造模结束后麻醉处死小鼠,测量结肠长度、观察结肠内容物及黏膜,采用苏木素-伊红(HE)染色观察各组小鼠结肠病理组织学变化,酶联免疫吸附试验(ELISA)检测各组小鼠结肠组织匀浆白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)水平,蛋白免疫印迹法(WB)检测各组小鼠结肠组织中磷酸化PI3K(p-PI3K)-p85、磷酸化AKT1(p-AKT1)、磷酸化NF-κB(p-NF-κB)-p65蛋白表达,实时荧光定量PCR技术(qRT-PCT)检测各组小鼠结肠组织PI3K、AKT、NF-κB信使RNA(mRNA)表达水平。结果与DSS组比较,CBD组治疗后,有效缓解UC小鼠症状,粪便性状及便血情况改善,结肠黏膜炎症浸润减少,体质量下降有所缓解,DAI评分降低及结肠长度接近正常,结肠组织匀浆中IL-6、TNF-α表达降低(P<0.05),p-PI3K-p85、p-AKT1、p-NF-κB-p65蛋白及mRNA表达明显减少(P<0.05)。结论肠病药方可缓解UC小鼠的症状、减轻结肠黏膜损伤,其机制可能与调解结肠组织中PI3K/AKT/NF-κB信号通路中相关蛋白质及mRNA表达、降低结肠组织炎症因子表达有关。

山姜素调控PI3K/Akt/NF-κB信号通路对冠心病大鼠心肌损伤的影响

目的:探讨山姜素调控磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(Akt)/核转录因子-κB(NF-κB)信号通路对冠心病(CHD)大鼠心肌损伤的影响。方法:选取健康成年SPF级SD雄性大鼠60只,随机分为空白组、模型组、山姜素小剂量组、山姜素中剂量组、山姜素高剂量组各12只,采用Western blot法检测大鼠PI3K/Akt/NF-κB信号通路蛋白表达,采用ELISA法检测大鼠炎症因子指标[肿瘤坏死因子α(TNF-α)、白介素-1β(IL-1β)、白介素-18(IL-18)]和氧化应激指标[活性氧(ROS)、谷胱甘肽过氧化物酶(GSH-Px)、丙二醛(MDA)],观察并记录大鼠心肌损伤情况。结果:与空白组比较,模型组的心肌缺血和心肌梗死面积更大(P<0.05),与模型组比较,山姜素小、中、高剂量组的心肌缺血和心肌梗死面积均缩小(P<0.05),且高剂量组的心肌缺血和心肌梗死面积小于山姜素中、小剂量组,中剂量组心肌缺血和心肌梗死面积小于山姜素小剂量组(P<0.05)。与空白组比较,模型组的PI3K、Akt、NF-κB更高(P<0.05),与模型组比较,山姜素小、中、高剂量组的PI3K、Akt、NF-κB均升高(P<0.05),且高剂量组的PI3K、Akt、NF-κB高于山姜素中、小剂量组,中剂量组PI3K、Akt、NF-κB高于山姜素小剂量组(P<0.05)。与空白组比较,模型组的TNF-α、IL-1β、IL-18更高(P<0.05),与模型组比较,山姜素小、中、高剂量组的TNF-α、IL-1β、IL-18均降低(P<0.05),且山姜素高剂量组的TNF-α、IL-1β、IL-18低于中、小剂量组,山姜素中剂量组的TNF-α、IL-1β、IL-18低于山姜素小剂量组(P<0.05)。与空白组比较,模型组的ROS、GSH-Px、MDA更高(P<0.05),与模型组比较,山姜素小、中、高剂量组的ROS、GSH-Px、MDA均降低(P<0.05),且山姜素高剂量组ROS、GSH-Px、MDA低于山姜素中、小剂量组,山姜素中剂量组的ROS、GSH-Px、MDA低于山姜素小剂量组(P<0.05)。结论:山姜素可通过调控PI3K/Akt/NF-κB信号通路改善CHD大鼠心肌炎症和氧化应激状况,进而发挥心肌保护作用。

替米沙坦通过磷脂酰肌醇-3-激酶/蛋白激酶B/哺乳动物雷帕霉素靶蛋白信号通路抑制硬化性胃癌细胞增殖

目的研究替米沙坦对硬化性胃癌(SGC)细胞增殖的影响,并探讨其作用机制。方法常规培养胃癌细胞MKN1和SGC细胞HSC45。采用细胞计数盒8实验检测替米沙坦对MKN1和HSC45增殖能力的影响;流式细胞仪检测替米沙坦对HSC45凋亡和细胞周期的影响;蛋白质印迹法检测激活替米沙坦对HSC45自噬和磷脂酰肌醇-3-激酶(PI3K)/蛋白激酶B(AKT)/哺乳动物雷帕霉素靶蛋白(mTOR)信号通路相关蛋白表达的影响;采用PI3K/AKT/mTOR信号通路激活剂SC79和替米沙坦共同处理HSC45,分别检测激活PI3K/AKT/mTOR信号通路后,替米沙坦对HSC45增殖、凋亡、自噬和细胞周期的影响。结果替米沙坦呈浓度和时间依赖性抑制MKN1和HSC45细胞增殖(均P<0.001),且对HSC45细胞增殖抑制效果更为显著(P<0.05)。替米沙坦组HSC45早期凋亡率、LC3Ⅱ/Ⅰ蛋白表达量、G_(0)/G_(1)期细胞周期比例均高于对照组[(26.2±2.6)%比(1.3±0.4)%、(1.02±0.09)比(0.29±0.04)、(53.4±3.4)%比(38.1±2.9)%],磷酸化PI3K、磷酸化AKT和磷酸化mTOR蛋白表达均低于对照组(均P<0.05)。替米沙坦组和替米沙坦+SC79组HSC45细胞增殖抑制率、细胞凋亡率、LC3Ⅱ/Ⅰ蛋白表达及G_(0)/G_(1)期细胞比例均高于对照组,但替米沙坦+SC79组均低于替米沙坦组(均P<0.05)。结论替米沙坦下调PI3K/AKT/mTOR信号通路,促进SGC细胞凋亡、自噬和周期阻滞,进而抑制SGC细胞增殖能力。

磷脂酰肌醇-3-激酶/蛋白激酶B与子宫内膜蜕膜化关系的研究进展

子宫内膜蜕膜化是决定妊娠能否成功的关键因素之一。磷脂酰肌醇-3-激酶(PI3K)是哺乳动物细胞内基础信号转导通路中的主要细胞因子,在细胞的生长、增殖、凋亡、自噬、血管生成等生理和病理过程中发挥着极其重要的生物学功能。PI3K/蛋白激酶B(PKB/Akt)信号通路在细胞代谢、迁移、分化等方面影响子宫内膜蜕膜化。深入研究PI3K/Akt在子宫内膜蜕膜化中的作用,可为蜕膜化缺陷相关疾病的诊断和治疗提供新思路,对更好地指导临床、提高妊娠成功率具有重要意义。