Myricetin induces M2 macrophage polarization to alleviate renal tubulointerstitial fibrosis in diabetic nephropathy via PI3K/Akt pathway

BACKGROUND Development of end-stage renal disease is predominantly attributed to diabetic nephropathy(DN).Previous studies have indicated that myricetin possesses the potential to mitigate the pathological alterations observed in renal tissue.Never-theless,the precise molecular mechanism through which myricetin influences the progression of DN remains uncertain.AIM To investigate the effects of myricetin on DN and explore its potential therapeutic mechanism.METHODS Db/db mice were administered myricetin intragastrically on a daily basis at doses of 50 mg/kg or 100 mg/kg for a duration of 12 wk.Subsequently,blood and urine indexes were assessed,along with examination of renal tissue pathology.Kidney morphology and fibrosis were evaluated using various staining techniques including hematoxylin and eosin,periodic acid–Schiff,Masson’s trichrome,and Sirius-red.Additionally,high-glucose culturing was conducted on the RAW 264.7 cell line,treated with 25 mM myricetin or co-administered with the PI3K/Akt inhibitor LY294002 for a period of 24 h.In both in vivo and in vitro settings,quantification of inflammation factor levels was conducted using western blotting,real-time qPCR and ELISA.RESULTS In db/db mice,administration of myricetin led to a mitigating effect on DN-induced renal dysfunction and fibrosis.Notably,we observed a significant reduction in expressions of the kidney injury markers kidney injury molecule-1 and neutrophil gelatinase associated lipocalin,along with a decrease in expressions of inflammatory cytokine-related factors.Furthermore,myricetin treatment effectively inhibited the up-regulation of tumor necrosis factor-alpha,interleukin-6,and interluekin-1βinduced by high glucose in RAW 264.7 cells.Additionally,myricetin modulated the M1-type polarization of the RAW 264.7 cells.Molecular docking and bioinformatic analyses revealed Akt as the target of myricetin.The protective effect of myricetin was nullified upon blocking the polarization of RAW 264.7 via inhibition of PI3K/Akt activation using LY294002.CONCLUSION This study demonstrated that myricetin effectively mitigates kidney injury in DN mice through the regulation of macrophage polarization via the PI3K/Akt signaling pathway.

Spi1 regulates the microglial/macrophage inflammatory response via the PI3K/AKT/mTOR signaling pathway after intracerebral hemorrhage

Preclinical and clinical studies have shown that microglia and macrophages participate in a multiphasic brain damage repair process following intracerebral hemorrhage.The E26 transformation-specific sequence-related transcription factor Spi1 regulates microglial/macrophage commitment and maturation.However,the effect of Spi1 on intracerebral hemorrhage remains unclear.In this study,we found that Spi1 may regulate recovery from the neuroinflammation and neurofunctional damage caused by intracerebral hemorrhage by modulating the microglial/macrophage transcriptome.We showed that high Spi1expression in microglia/macrophages after intracerebral hemorrhage is associated with the activation of many pathways that promote phagocytosis,glycolysis,and autophagy,as well as debris clearance and sustained remyelination.Notably,microglia with higher levels of Soil expression were chara cterized by activation of pathways associated with a variety of hemorrhage-related cellular processes,such as complement activation,angiogenesis,and coagulation.In conclusion,our results suggest that Spi1 plays a vital role in the microglial/macrophage inflammatory response following intracerebral hemorrhage.This new insight into the regulation of Spi1 and its target genes may advance our understanding of neuroinflammation in intracerebral hemorrhage and provide therapeutic targets for patients with intracerebral hemorrhage.

Downregulation of Serum PTEN Expression in Mercury-Exposed Population and PI3K/AKT Pathway-Induced Inflammation

Objective This study investigated the impact of occupational mercury(Hg) exposure on human gene transcription and expression, and its potential biological mechanisms.Methods Differentially expressed genes related to Hg exposure were identified and validated using gene expression microarray analysis and extended validation. Hg-exposed cell models and PTEN lowexpression models were established in vitro using 293T cells. PTEN gene expression was assessed using qRT-PCR, and Western blotting was used to measure PTEN, AKT, and PI3K protein levels. IL-6 expression was determined by ELISA.Results Combined findings from gene expression microarray analysis, bioinformatics, and population expansion validation indicated significant downregulation of the PTEN gene in the high-concentration Hg exposure group. In the Hg-exposed cell model(25 and 10 μmol/L), a significant decrease in PTEN expression was observed, accompanied by a significant increase in PI3K, AKT, and IL-6 expression.Similarly, a low-expression cell model demonstrated that PTEN gene knockdown led to a significant decrease in PTEN protein expression and a substantial increase in PI3K, AKT, and IL-6 levels.Conclusion This is the first study to report that Hg exposure downregulates the PTEN gene, activates the PI3K/AKT regulatory pathway, and increases the expression of inflammatory factors, ultimately resulting in kidney inflammation.

Hypoglycemic mechanism of Tegillarca granosa polysaccharides on type 2 diabetic mice by altering gut microbiota and regulating the PI3K-akt signaling pathwaye

Type 2 diabetes mellitus(T2DM)is a complex metabolic disease threatening human health.We investigated the effects of Tegillarca granosa polysaccharide(TGP)and determined its potential mechanisms in a mouse model of T2DM established through a high-fat diet and streptozotocin.TGP(5.1×10^(3) Da)was composed of mannose,glucosamine,rhamnose,glucuronic acid,galactosamine,glucose,galactose,xylose,and fucose.It could significantly alleviate weight loss,reduce fasting blood glucose levels,reverse dyslipidemia,reduce liver damage from oxidative stress,and improve insulin sensitivity.RT-PCR and Western blotting indicated that TGP could activate the phosphatidylinositol-3-kinase/protein kinase B signaling pathway to regulate disorders in glucolipid metabolism and improve insulin resistance.TGP increased the abundance of Allobaculum,Akkermansia,and Bifidobacterium,restored the microbiota abundance in the intestinal tracts of mice with T2DM,and promoted short-chain fatty acid production.This study provides new insights into the antidiabetic effects of TGP and highlights its potential as a natural hypoglycemic nutraceutical.

MicroRNA (let-7b-5p)-targeted DARS2 regulates lung adenocarcinoma growth by PI3K/AKT signaling pathway

Background:The aberrant intraellular expression of a mitochondrial aspartyl tRNA synthetase 2(DARS2)has been reported in human cancers.Nevertheless its critical role and detailed mechanism in lung adenocarcinoma(LUAD)remain unexplored.Methods:Initially,The Cancer Genome Atlas(TCGA)based Gene Expression Profiling Interactive Analysis(GEPIA)database (http:/gepia.cancer-pku.cn/)was used to analyze the prognostic relevance of DARS2 expression in LUAD.Further,cell counting kit(CCK)8,immunostaining,and transwell invasion assays in LUAD cell lines in vitro,as well as DARS2 silence on LUAD by tumorigenicity experiments in wivo in nude mice,were performed.Besides,we analyzed the expression levels of p-PI3K(phosphorylated Phosphotylinosital3 kinase),PI3K,AKT(Protein Kinase B),p-AKT(phosphorylated Protein Kinase B),PCNA(proliferating cell nudear antigen),cleaved-caspase 3,E cadherin,and N-cadherin proteins using the Westem blot analysis.Results:LUAD tissues showed higher DARS2 expression compared to normal tissues.Upregulation of DARS2 could be related to Tumor-Node-Metastasis(TNM)stage,high lymph node metastasis,and inferior prognosis.DARS2 silence decreased the proliferation,migration,and invasion abilities of LUAD cells.In addition,the DARS2 downregulation decreased the PCNA and N-cadherin expression and increased cleaved:caspase 3 and E cadherin expressions in LUAD cells,coupled with the inactivation of the PI3K/AKT signaling pathway.Moreover,DARS2 silence impaired the tumonigenicity of LUAD in vivo.Interestingly,let:7b-5p could recognize DARS2 through a complementary sequence.Mechanistically,the increased let 7b 5p expression attenuated the promo oncogenic action of DARS2 during LUAD progression,which were inversely correlated to each other in the LUAD tssues Conclusion:In summary,let 7b-5p,downregulated DARS2 expression,regulating the progression of LUAD cells by the PI3K/AKT signaling pathway.

Alleviatory effect of isoquercetin on benign prostatic hyperplasia via IGF-1/PI3K/Akt/mTOR pathway

We evaluated the effect of isoquercetin(quercetin-O-3-glucoside-quercetin,IQ)as a functional component of Abeliophyllum disistichum Nakai ethanol extract(ADLE)on prostate cell proliferation and apoptosis and its effects on the IGF-1/PI3K/Akt/mTOR pathway in benign prostatic hyperplasia(BPH).Metabolites in ADLE were analyzed using UHPLC-qTOF-MS and HPLC.IQ was orally administered(1 or 10 mg/kg)to a testosterone propionate-induced BPH rat model,and its effects on the prostate weight were evaluated.The effect of IQ on androgen receptor(AR)signaling was analyzed in LNCaP cells.Whether IGF-1 and IQ affect the IGF-1/PI3K/Akt/mTOR pathway in BPH-1 cells was also examined.The metabolites in ADLE were identified and quantified,which confirmed that ADLE contained abundant IQ(20.88 mg/g).IQ significantly reduced the prostate size in a concentration-dependent manner in a BPH rat model,and significantly decreased the expression of AR signaling factors in the rat prostate tissue and LNCaP cells in a concentration-dependent manner.IQ also inhibited the PI3K/AKT/mTOR pathway activated by IGF-1 treatment in BPH-1 cells.In BPH-1 cells,IQ led to G0/G1 arrest and suppressed the expression of proliferation factors while inducing apoptosis.Thus,IQ shows potential for use as a pharmaceutical and nutraceutical for BPH.

Acalypha australis L.extract inhibits B16 melanoma cell metastasis through PI3K/AKT signaling pathway

Background:Melanoma is a deadly skin tumor resulting from the malignant transformation of melanocytes.It is highly malignant and invasive,with the highest mortality rate among skin cancers.Acalypha australis L.(AAL),a plant with dual medicinal and culinary purposes,is commonly regarded as an edible wild vegetable in southern China.Additionally,AAL has a long history of medicinal use in China,often employed for its hemostatic,anti-diarrheal,and anti-inflammatory properties.Modern pharmacology has demonstrated that AAL possesses functions such as weight loss,antimicrobial activity,antiviral effects,and treatment for ulcerative colitis.However,there is currently no research available regarding its effectiveness and mechanisms of action on melanoma.Methods:In this investigation,we used methyl thiazolyl tetrazolium assay to detect cell viability,transwell assay to detect cell migration and invasion ability,and Western blot assay to detect relevant signaling pathways.Results:The present study reveals that 2 mg/mL AAL effectively suppresses the metastasis of B16 cells,while simultaneously triggering the expression of key apoptosis-related proteins,including Bcl-2,Bax,and cleaved caspased 3.Subsequent investigations demonstrate that AAL exerts this inhibitory effect via the PI3K/AKT signal transduction pathway,as evidenced by the observed deficits in Ras,AKT,p-AKT,and PI3K expression levels.Conclusion:These findings indicated that AAL could be a valuable therapeutic option for reducing the metastatic potential of B16 melanoma cells.

抑制PI3K/PKB通路逆转胃癌耐药的作用及其机制

目的观察抑制PI3K/PKB信号通路对胃癌耐药性的逆转作用,并探讨其可能机制。方法通过体内外实验方法检测长春新碱(vincristine,VCR)及联合LY294002(PI3K/PKB通路抑制剂)对SGC7901/VCR细胞的生长抑制作用;采用Western blot及RT-PCR分别检测细胞中PKB、磷酸化PKB的蛋白表达水平及MDR1、Bax、Bcl-2基因表达水平;流式细胞仪检测细胞的凋亡。结果LY294002能明显增加SGC7901/VCR细胞对VCR的敏感性,促进VCR诱导细胞凋亡,使其耐药指数从40.45降至8.50;LY294002可明显降低耐药细胞中磷酸化PKB的蛋白表达和MDR1、Bcl-2的基因表达水平(P<0.01),促进Bax的基因表达(P<0.01);体内实验显示联合用药组的裸鼠移植瘤大小明显小于VCR组(P<0.01)。结论抑制PI3K/PKB通路可逆转胃癌耐药,其机制可能与降低耐药基因MDR1的表达以及调控相关凋亡基因Bax和Bcl-2的表达有关。

PI3K/PKB信号通路在TGF-β_1诱导人肝星状细胞表达骨桥蛋白中的作用

目的:研究磷脂酰肌醇3-激酶/蛋白激酶B(PI3K/PKB)信号通路在转化生长因子β1(TGF-β1)诱导人肝星状细胞表达骨桥蛋白(OPN)的调控作用。方法:体外培养LX-2人肝星状细胞株,予TGF-β1(终浓度2.5、5、10、20μg/L)刺激24 h或予TGF-β1(终浓度10μg/L)刺激12 h、24 h、48 h;先经PI3K/PKB信号通路特异性抑制剂wortmannin(0.1μmol/L)预处理1 h,再予10μg/L TGF-β1刺激24 h,收集细胞,采用real-time PCR及Western blotting法检测OPN表达情况。结果:TGF-β1能够促进LX-2细胞表达OPN,在一定浓度和时间范围内,其表达量随着TGF-β1浓度和时间的增加而增加,呈剂量和时间依赖性关系;经wortmannin预处理再予TGF-β1刺激的LX-2细胞,与对照组相比,OPN表达受到明显抑制(P<0.01)。结论:TGF-β1对LX-2人肝星状细胞OPN表达具有诱导作用,此作用可能受PI3K/PKB信号通路的调控。

高住低练对大鼠骨骼肌PI3K/PKB/mTOR信号通路基因表达的影响

目的:探讨高住低练对大鼠骨骼肌PI3K/PKB/mTOR信号通路基因表达的影响。方法:40只8周龄SD大鼠适应训练后,随机分为低住安静组(LC)、低住低练组(LoLo)、高住安静组(HC)和高住低练组(HiLo)。高住组每天低氧暴露12 h(氧浓度13.6%,相当于海拔3500 m),低练组进行35 m/min、1 h/d、5 d/周、共4周的跑台训练。采用实时荧光定量PCR检测大鼠腓肠肌PI3K、PKB、mTOR mRNA表达,以双因素方差分析进行统计。结果:低氧和运动均显著提高大鼠骨骼肌PI3K和PKB mRNA表达(P<0.01),但低氧和运动无显著交互作用(P>0.05);运动显著提高大鼠骨骼肌mTOR mRNA表达(P<0.01),低氧却显著降低mTOR mRNA表达(P<0.01),且低氧和运动有交互作用,显著降低mTOR mRNA表达(P<0.01)。结论:低氧和运动促进PI3K和PKB基因表达,低氧抑制而运动促进mTOR基因表达;HiLo训练促进PI3K和PKB基因表达,却抑制mTOR基因表达。不同条件下PI3K/PKB/mTOR信号通路基因表达水平不一致。

Melatonin improves synapse development by PI3K/Akt signaling in a mouse model of autism spectrum disorder

Autism spectrum disorders are a group of neurodevelopmental disorders involving more than 1100 genes,including Ctnnd2 as a candidate gene.Ctnnd2knockout mice,serving as an animal model of autis m,have been demonstrated to exhibit decreased density of dendritic spines.The role of melatonin,as a neuro hormone capable of effectively alleviating social interaction deficits and regulating the development of dendritic spines,in Ctnnd2 deletion-induced nerve injury remains unclea r.In the present study,we discove red that the deletion of exon 2 of the Ctnnd2 gene was linked to social interaction deficits,spine loss,impaired inhibitory neurons,and suppressed phosphatidylinositol-3-kinase(PI3K)/protein kinase B(Akt) signal pathway in the prefrontal cortex.Our findings demonstrated that the long-term oral administration of melatonin for 28 days effectively alleviated the aforementioned abnormalities in Ctnnd2 gene-knockout mice.Furthermore,the administration of melatonin in the prefro ntal cortex was found to improve synaptic function and activate the PI3K/Akt signal pathway in this region.The pharmacological blockade of the PI3K/Akt signal pathway with a PI3K/Akt inhibitor,wo rtmannin,and melatonin receptor antagonists,luzindole and 4-phenyl-2-propionamidotetralin,prevented the melatonin-induced enhancement of GABAergic synaptic function.These findings suggest that melatonin treatment can ameliorate GABAe rgic synaptic function by activating the PI3K/Akt signal pathway,which may contribute to the improvement of dendritic spine abnormalities in autism spectrum disorders.

自噬和PI3K/PKB通路在七氟烷麻醉结肠癌手术患者神经认知紊乱中的作用研究

目的探讨自噬和PI3K/PKB通路在七氟烷麻醉结肠癌手术患者神经认知紊乱中的作用。方法选取2016年1月至2019年1月在郑州人民医院接受腹腔镜下结肠癌根治术治疗的100例老年结肠癌患者作为研究对象,并随机分为SEV组(麻醉通过七氟醚)和ISO组(麻醉通过异氟烷),每组50例。比较两组术前和术后1 d血清PI3K和PKB的表达水平,分析血液中LC3Ⅰ和LC3Ⅱ表达水平;记录两组简易智力状态检查(MMSE)量表评分;比较两组不良反应发生情况,并进行线性关系分析。结果与ISO组比较,SEV组术后1 d血清PI3K和PKB表达水平降低(P<0.05),而血液LC3Ⅱ表达水平明显增加(P<0.05),MMSE评分增加(P<0.05)。SEV组术后1 d认知功能障碍的发生率低于ISO组(P<0.05)。MMSE评分与PI3K和PKB表达水平呈负相关关系(r=-0.412和-0.398,P<0.001),而与LC3Ⅰ和LC3Ⅱ表达水平呈正相关关系(r=0.452和0.427,P<0.001)。结论七氟烷可以通过PI3K/PKB信号通路调节神经细胞自噬,改善结肠癌手术患者术后的认知功能。

PI3K/PKB信号激活在妊娠滋养细胞疾病发病机制中的作用

目的:探讨磷脂酰肌醇3-激酶/蛋白激酶B(PI3K/PKB)信号激活对妊娠滋养细胞疾病(GTD)进展及相关干细胞转录因子FoxD3、Nanog、Stat3、Oct4和Sox2表达的影响。方法:选取20例正常胎盘、38例良性转归葡萄胎(HM-regressed)和13例恶性进展葡萄胎(HM-progressed)、6例绒癌的石蜡包埋组织,采用免疫组化检测p-PKBSer473表达。实时荧光定量PCR(RT-PCR)和Western blot法检测绒癌细胞株JEG3和JAR中FoxD3、Nanog、Stat3、Oct4和Sox2 mRNA和蛋白表达。CCK8和Transwell小室检测细胞增殖、迁移/侵袭能力。结果:p-PKBSer473表达的免疫组化评分由高到低依次为绒癌、HM-progressed、HM-regressed和正常胎盘,两两比较差异均有统计学意义(P<0.05)。PI3K抑制剂LY294002阻遏了PKB的活化,显著减弱了绒癌细胞的增殖、迁移和侵袭能力,降低了FoxD3、Nanog、Stat3的mRNA和蛋白表达,差异均有统计学意义(P<0.05)。结论:PI3K/PKB信号通道激活与GTD的进展和侵袭表型有关,可通过增强调控滋养细胞的干细胞特性而发挥作用。

肉苁蓉苯乙醇总苷对压力超负荷大鼠心肌肥厚及PI3K/PKB信号通路的影响

目的探讨肉苁蓉苯乙醇总苷(CPhGs)对压力超负荷大鼠心肌肥厚的抑制作用及其可能的作用机制。方法♂SPF级SD大鼠70只,随机分为空白组(Con)、假手术组(Sham)、模型组(Mod)、阳性药对照组(Vst)、CPhGs 125、250、500 mg·kg^-1组。检测心脏超声指标、心脏体质量指数(HWI)、心肌组织病理学变化、心肌细胞面积(AMC),Elisa法检测血浆ET-1、BNP水平,Western blot法检测p-PI3K、PI3K、p-PKB、PKB蛋白表达变化。结果与Mod组相比,CPhGs不同剂量给药后,LVPWT、HWI、血浆ET-1和BNP、AMC均有不同程度下降,LVEDD、LVEF、LVFS以及心肌组织p-PI3K、p-PKB蛋白表达有不同程度的增加,其中CPhGs 250、500 mg·kg^-1组相比于Mod组各指标有明显差异(P<0.05或0.01);与Vst组相比,CPhGs 500 mg·kg^-1组各指标,没有明显差异。结论CPhGs对压力超负荷引起的大鼠心肌肥厚具有抑制作用,其作用可能与PI3K/PKB信号通路的激活有关。

PI3K/PKB信号通路在重症急性胰腺炎肺损伤发病机制中的研究进展

PI3K/PKB信号通路广泛存在于组织细胞中,参与细胞的生长、增殖、凋亡等重要生理活动。近年来研究发现该信号通路与重症急性胰腺炎急性肺损伤的发病过程密切相关。因此,本文就该通路在重症急性胰腺炎肺损伤发病机制中的研究现状作一综述。

Activation of the PI3K/AKT pathway mediates FSH-stimulated VEGF expression in ovarian serous cystadenocarclnoma

There is evidence to suggest that follicle-stimulating hormone （FSH） can facilitate the neovascularization of ovarian cancers by increasing vascular endothelial growth factor （VEGF） expression in cancer cells, although the underlying molecular mechanism of this process is not well known. Therefore, we investigated the effect of FSH on VEGF expression in the ovarian cancer cell lines SKOV-3 and ES-2. Treatment with FSH significantly increased VEGF expression in a dose- and time-dependent manner. In addition, FSH treatment enhanced the expression of survivin and hypoxlainducible factor-1 （HIF-1α）. Knockdown of survivin or HIF-1α suppressed VEGF expression, but only knockdown of survivin inhibited FSH-stimulated VEGF expression. Pretreatment with LY294002, a phosphoinositide 3-kinase （PI3K）/AKT inhibitor, neutralized the enhanced expression of survivin induced by FSH, but treatment with U0126, a mitogen-activated protein kinase/extracellular signal-regulated kinase inhibitor, had no such effect. We further showed that ovarian serous cystadenocarcinoma samples had much higher incidence of positive AKT and phosphorylated AKT （pAKT） protein staining than did benign ovarian cystadenoma samples （p 〈 0.01）. The 5-year survival rate was only about 15% in patients with ovarian serous cystadenocarcinoma who had AKT and pAKT expression, whereas it was about 80% in those who did not have AKT or pAKT expression. Taken together, these results indicate that FSH increases the expression of VEGF by upregulating the expression of survivin, which is activated by the PI3K/AKT signaling pathway. Understanding the role of the PI3K/AKT pathway in FSH-stimulated expression of survivin and VEGF will be beneficial for evaluating the prognosis for patients with ovarian serous cystadenocarcinoma and for pursulug effective treatment against this disease.

Baicalin attenuates blood-spinal cord barrier disruption and apoptosis through PI3K/Akt signaling pathway after spinal cord injury

Baicalin is a natural active ingredient isolated from Scutellariae Radix that can cross the blood-brain barrier and exhibits neuroprotective effects on multiple central nervous system diseases.However,the mechanism behind the neuroprotective effects remains unclear.In this study,rat models of spinal cord injury were established using a modified Allen's impact method and then treated with intraperitoneal injection of Baicalin.The results revealed that Baicalin greatly increased the Basso,Beattie,Bresnahan Locomotor Rating Scale score,reduced blood-spinal cord barrier permeability,decreased the expression of Bax,Caspase-3,and nuclear factorκB,increased the expression of Bcl-2,and reduced neuronal apoptosis and pathological spinal cord injury.SH-SY5 Y cell models of excitotoxicity were established by application of 10 m M glutamate for 12 hours and then treated with 40μM Baicalin for 48 hours to investigate the mechanism of action of Baicalin.The results showed that Baicalin reversed tight junction protein expression tendencies(occludin and ZO-1)and apoptosis-related protein expression(Bax,Bcl-2,Caspase-3,and nuclear factor-κB),and also led to up-regulation of PI3 K and Akt phosphorylation.These effects on Bax,Bcl-2,and Caspase-3 were blocked by pretreatment with the PI3 K inhibitor LY294002.These findings suggest that Baicalin can inhibit bloodspinal cord barrier permeability after spinal cord injury and reduce neuronal apoptosis,possibly by activating the PI3 K/Akt signaling pathway.This study was approved by Animal Ethics Committee of Xi'an Jiaotong University on March 6,2014.

Fibroblast-derived CXCL12/SDF-1α promotes CXCL6 secretion and co-operatively enhances metastatic potential through the PI3K/Akt/m TOR pathway in colon cancer

AIM To investigate the underlying mechanism by which CXCL12 and CXCL6 influences the metastatic potential of colon cancer and internal relation of colon cancer and stromal cells. METHODS Western blotting was used to detect the expression of CXCL12 and CXCL6 in colon cancer cells and stromal cells. The co-operative effects of CXCL12 and CXCL6 on proliferation and invasion of colon cancer cells and human umbilical vein endothelial cells(HUVECs) were determined by enzyme-linked immunosorbent assay,and proliferation and invasion assays. The angiogenesis of HUVECs through interaction with cancer cells and stromal cells was examined by angiogenesis assay. We eventually investigated activation of PI3K/Akt/m TOR signaling by CXCL12 involved in the metastatic process of colon cancer.RESULTS CXCL12 was expressed in DLD-1 cancer cells and fibroblasts. The secretion level of CXCL6 by colon cancer cells and HUVECs were significantly promoted by fibroblasts derived from CXCL12. CXCL6 and CXCL2 could significantly enhance HUVEC proliferation and migration(P < 0.01). CXCL6 and CXCL2 enhanced angiogenesis by HUVECs when cultured with fibroblast cells and colon cancer cells(P < 0.01). CXCL12 also enhanced the invasion of colon cancer cells. Stromal cell-derived CXCL12 promoted the secretion level of CXCL6 and co-operatively promoted metastasis of colon carcinoma through activation of the PI3K/Akt/m TOR pathway.CONCLUSION Fibroblast-derived CXCL12 enhanced the CXCL6 secretion of colon cancer cells,and both CXCL12 and CXCL6 co-operatively regulated the metastasis via the PI3K/Akt/m TOR signaling pathway. Blocking this pathway may be a potential anti-metastatic therapeutic target for patients with colon cancer.

PI3K/AKT/mTOR signaling pathway inhibitors in proliferation of retinal pigment epithelial cells

AIM: To determine whether the PI3K/AKT/mTOR pathway is activated in proliferative vitreoretinopathy (PVR) in homo-sapiens. METHODS: The retina of controls and patients with PVR were collected and their levels of PI3K, phospho-AKT, phospho-mTOR, phospho-p70S6k and phospho-4EBP-1 were determined by Western blot. The cultured human retinal pigment epithelial cell line D407 was treated with a specific mTOR inhibitor, rapamycin (RAPA) or a PI3K inhibitor, LY294002, of various concentrations and durations. Cell morphology was observed by phase contrast microscopy and the proliferation and apoptosis of treated cells were determined by MTT assay and flow cytometry. RESULTS: Levels of PI3K, phospho-AKT, phospho-mTOR, phospho-P70S6K and phospho-4EBP1 was increased in the retina in PVR (P <0.05). In D407 cells, both RAPA and LY294002 significantly inhibited cell proliferation and cell cycle progression, and promoted apoptosis (P <0.05); morphologically, the cells became smaller. Both RAPA and LY294002 reduced levels of phospho-AKT, phospho-mTOR, phospho-p70S6k and phospho-4EBP1 expression (P <0.05). RAPA, but not LY294002, had no significant effect on PI3K expression. CONCLUSION: PI3K/AKT/mTOR signaling pathway is highly activated in the retinal pigment epithelial cells of PVR. The inhibitors of PI3K/AKT/mTOR signaling pathway, RAPA and LY294002, could inhibited the PI3K/AKT/mTOR signaling pathway by reducing the levels of phosphorylation of mTOR pathway components.

shRNA-interfering LSD1 inhibits proliferation and invasion of gastric cancer cells via VEGF-C/PI3K/AKT signaling pathway

BACKGROUND Histone Lysine Specific Demethylase 1(LSD1)is the first histone demethylase to be discovered,which regulates various biological functions by making lysine of histone H3K4,H3K9 and non-histone substrates demethylated.Abnormal regulation of LSD1 is closely related to the occurrence and development of gastric cancer.The change of LSD1 expression level plays an important role in the proliferation and metastasis of gastric cancer cells.The study of its function and mechanism may provide a theoretical basis for early diagnosis and targeted therapy of gastric cancer.AIM To investigate the effect of downregulation of lysine-specific demethylase 1(LSD1)expression on proliferation and invasion of gastric cancer cells and the possible regulatory mechanisms of the VEGF-C/PI3K/AKT signaling pathway.METHODS The LSD1-specific short hairpin RNA(shRNA)interference plasmid was transiently transfected,and expression of LSD1 was downregulated.The cell proliferation ability of LSD1 was observed by CCK-8 assay after downregulating expression of LSD1.Transwell invasion assay was used to observe the change of cell invasion ability after downregulating expression of LSD1.Expression of phosphorylated phosphoinositide 3-kinase(p-PI3K),PI3K,p-AKT,AKT,vascular endothelial growth factor receptor(VEGFR)-3,matrix metalloproteinase(MMP)-2 and MMP-9 in each group was detected by Western blotting.RESULTS The cell proliferation ability of transiently transfected LSD1-shRNA interference plasmid group was significantly lower than that of the control group(P<0.05).Transwell invasion assay showed that the number of cells across the membrane of the LSD1-shRNA transfection group(238.451±5.216)was significantly lower than that of the control group(49.268±6.984)(P<0.01).Western blotting showed that expression level of VEGF-C,p-PI3K,PI3K,p-AKT,AKT,VEGFR-3,MMP-2 and MMP-9 in the LSD1-shRNA group was significantly lower than that in the control group(P<0.05).CONCLUSION Downregulation of LSD1 expression inhibits metastatic potential of gastric cancer cells,and VEGF-C-mediated activation of PI3K/AKT signaling pathway,which may be an important mechanism for inhibiting lymph node metastasis in gastric cancer cells.