Sphingosine kinase-2 induced autophagy activation mediates ischemic tolenrance in primary cortical neurons

Aim This study is aimed to determine whether SPK2 （Sphingosine kinase-2） is involved in isoflurane preconditioning induced autophagy activation in primary cultured neurons. We also examined whether SPK2 pro- tects neurons from ischemic injury by activating autophagy, and explored the molecular mechanism of SPK2 contrib- uting to the autophagy activation in neurons. Methods Isoflurane preconditioning （ISO） and oxygen glucose dep- rivation （OGD） model was established in primary cultured murine cortical neurons. Neurons were transfected by siRNA to interfere SPK2 and Beclin 1, or lentivirus to overexpress SPK2. Protein expression of SPK2, LC3, and Beclinl were detected with immunofluorescence and Western blot analysis. The neurons were treated with lysosomal inhibitor ammonium chloride （NH4 C1） to test the autophagy flux. The protection of SPK2 on OGD/R induced neu- ronal death was detected with CCK-8 （cell counting kit-8） and LDH cytotoxicity assay kit. Autophagy inhibitor 3- MA （3-Methyladenine） was used to detect the protection of autophagy on SPK2 induced isehemie tolerance. Co-im- munoprecipitation was used to detect the interaction between Beclin 1 and Bel-2. Results In primary cultured neu- ISO enhanced SPK2 and LC3 immunofluorescenee. SPK2 siRNA inhibits LC3II upregulation induced by rons, ISO. Beclin 1 siRNA also inhibits LC3II upregulation induced by ISO. Lentivirus-indueed SPK2 overexpression in- creased LC3II/LC3I ratio and enhanced the autophagy flux in neurons. SPK2 overexpression also exerted neuropro- teetion against OGD model in cortical neurons, as evidenced by improvement of neuronal morphology, increased cellular viability and reduced LDH leakage, while 3-MA partly abolished the SPK2-induced neuroprotection. After SPK2 overexpression, Beclin 1 siRNA inhibited SPK2 induced LC3II upregulation, and the coimmunoprecipitation of Beclin 1 and Bcl-2 was reduced.. Conclusion ISO increases SPK2 and activates autophagy in neurons. SPK2 or Beclin 1 interference cancels ISO induced autophagy activation. SPK2 overexpression activates autophagy, and protects the neurons against ischemic injury. SPK2 may induce autophagy by disrupting Beclin 1/Bcl-2 interaction.

Casein kinase-2 inhibition promotes retinal ganglion cell survival after acute intraocular pressure elevation

Intraocular pressure elevation can induce retinal ganglion cell death and is a clinically reversible risk factor for glaucoma,the leading cause of irreversible blindness.We previously demonstrated that casein kinase-2 inhibition can promote retinal ganglion cell survival and axonal regeneration in rats after optic nerve injury.To investigate the underlying mechanism,in the current study we increased the intraocular pressure of adult rats to 75 mmHg for 2 hours and then administered a casein kinase-2 inhibitor(4,5,6,7-tetrabromo-2-azabenzimidazole or 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole)by intravitreal injection.We found that intravitreal injection of 4,5,6,7-tetrabromo-2-azabenzimidazole or 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole promoted retinal ganglion cell survival and reduced the number of infiltrating macrophages.Transcriptomic analysis showed that the mitogen activated protein kinase signaling pathway was involved in the response to intraocular pressure elevation but was not modulated by the casein kinase-2 inhibitors.Furthermore,casein kinase-2 inhibition downregulated the expression of genes(Cck,Htrsa,Nef1,Htrlb,Prph,Chat,Slc18a3,Slc5a7,Scn1b,Crybb2,Tsga10ip,and Vstm21)involved in intraocular pressure elevation.Our data indicate that inhibition of casein kinase-2 can enhance retinal ganglion cell survival in rats after acute intraocular pressure elevation via macrophage inactivation.

MiRNA-145-5p inhibits gastric cancer progression via the serpin family E member 1-extracellular signal-regulated kinase-1/2 axis

BACKGROUND MicroRNAs(miRNAs)regulate gene expression and play a critical role in cancer physiology.However,there is still a limited understanding of the function and regulatory mechanism of miRNAs in gastric cancer(GC).AIM To investigate the role and molecular mechanism of miRNA-145-5p(miR145-5p)in the progression of GC.METHODS Real-time polymerase chain reaction(RT-PCR)was used to detect miRNA expression in human GC tissues and cells.The ability of cancer cells to migrate and invade was assessed using wound-healing and transwell assays,respectively.Cell proliferation was measured using cell counting kit-8 and colony formation assays,and apoptosis was evaluated using flow cytometry.Expression of the epithelial-mesenchymal transition(EMT)-associated protein was determined by Western blot.Targets of miR-145-5p were predicated using bioinformatics analysis and verified using a dual-luciferase reporter system.Serpin family E member 1(SERPINE1)expression in GC tissues and cells was evaluated using RT-PCR and immunohistochemical staining.The correlation between SERPINE1 expression and overall patient survival was determined using Kaplan-Meier plot analysis.The association between SERPINE1 and GC progression was also tested.A rescue experiment of SERPINE1 overexpression was conducted to verify the relationship between this protein and miR-145-5p.The mechanism by which miR-145-5p influences GC progression was further explored by assessing tumor formation in nude mice.RESULTS GC tissues and cells had reduced miR-145-5p expression and SERPINE1 was identified as a direct target of this miRNA.Overexpression of miR-145-5p was associated with decreased GC cell proliferation,invasion,migration,and EMT,and these effects were reversed by forcing SERPINE1 expression.Kaplan-Meier plot analysis revealed that patients with higher SERPINE1 expression had a shorter survival rate than those with lower SERPINE1 expression.Nude mouse tumorigenesis experiments confirmed that miR-145-5p targets SERPINE1 to regulate extracellular signal-regulated kinase-1/2(ERK1/2).CONCLUSION This study found that miR-145-5p inhibits tumor progression and is expressed in lower amounts in patients with GC.MiR-145-5p was found to affect GC cell proliferation,migration,and invasion by negatively regulating SERPINE1 levels and controlling the ERK1/2 pathway.

Sphingosine kinase 1 is upregulated with lysophosphatidic acid receptor 2 in human colorectal cancer

AIM: To examine the expression of Sph K1, an oncogenic kinase that produces sphingosine 1-phosphate(S1P), and its correlation with the expression of LPAR2, a major lysophosphatidic acid(LPA) receptor overexpressed in various cancers, in human colorectal cancer.METHODS: Real-time reverse-transcription polymerase chain reaction was used to measure the m RNA expression of Sph K1, LPAR2, and the three major S1 P receptors in 27 colorectal cancer samples and corresponding normal tissue samples. We also examined the correlation between the expression of Sph K1 and LPAR2.RESULTS: C o l o r e c t a l c a n c e r t i s s u e i n 2 2 o f 2 7 patients had higher levels of Sph K1 m RNA than in normal tissue. In two-thirds of the samples, Sph K1 m RNA expression was more than two-fold higher than in normal tissue. Consistent with previous reports, LPAR2 m RNA expression in 20 of 27 colorectal cancer tissue samples was higher compared to normal tissue samples. Expression profiles of all three major S1 P receptors, S1PR1, S1PR2, and S1PR3, varied without any trend, with no significant difference in expression between cancer and normal tissues. A highly significant positive correlation was found between Sph K1 and LPAR2 expression [Pearson's correlation coefficient(r) = 0.784 and P < 0.01]. The m RNA levels of Sph K1 and LPAR2 did not correlate with TNM stage.CONCLUSION: Our findings suggest that S1 P andLPA may play important roles in the development ofcolorectal cancer via the upregulation of Sph K1 andLPAR2, both of which could serve as new therapeutictargets in the treatment of colorectal cancer.

Sodium Butyrate Induces Apoptosis of Human Colon Cancer Cells by Modulating ERK and Sphingosine Kinase 2

Objective To investigate the role of extracellular signal-regulated kinase （ERK） in apoptosis of human colon cancer （HCT116） cells. Methods After the HCT116 cells were pretreated with specific ERK inhibitor （U0126） or specific siRNA and exposed to 10 mmol/L sodium butyrate （NaBT） for 24 h, their apoptosis was detected by flow cytometry, levels of SphK2 and ERK protein were measured by Western blot, and translocation of SphK2 was assayed by immunofluorescence microscopy. Results The U0126 and siRNAs specific for SphK2 blocked the export of SphK2 from nuclei to cytoplasm and increased the apoptosis of HCT116 cells following NaBT exposure. Over-expression of PKD decreased NaBT-induced apoptosis of HCT116 cells, which was reversed by U0126. Furthermore, transfection of HCT116 cells with constitutively activated PKD plasmids recovered the UO126-blocked export of SphK2. Conclusion ERK regulates the export of SphK2 and apoptosis of HCT116 cells by modulating PKD. Modulation of these molecules may help increase the sensitivity of colon cancer cells to the physiologic anti-colon cancer agent, NaBT.

基于生物信息学分析SPNS2对乳腺癌预后、诊断或免疫浸润的影响

目的应用生物信息学方法探讨鞘氨醇-1-磷酸转运体2(sphingosine-1-phosphate transporter 2,SPNS2)在乳腺癌中的表达情况,并分析SPNS2对乳腺癌预后、诊断或免疫浸润的影响。方法癌症基因组图谱(The Cancer Genome Atlas,TCGA)数据库检索乳腺癌组织和非乳腺癌样本中的SPNS2 mRNA差异表达数据,并分析SPNS2与乳腺癌之间的关系。用Cox单因素及多因素模型分析SPNS2 mRNA表达对乳腺癌预后的影响。使用Kaplan-Meier曲线评估SPNS2基因的表达与存活率之间的相关性,分析SPNS2对乳腺癌患者生存预后的影响。使用受试者工作特征曲线(receiver operating characteristic,ROC)分析SPNS2对乳腺癌的诊断效能。使用肿瘤免疫估算资源(Tumor Immune Estimation Resource,TIMER)数据库分析SPNS2表达与乳腺癌免疫微环境中不同类型免疫细胞的相关性。搜索相互作用基因检索的工具(Search Tool for the Retrieval of Interacting Genes,STRING)数据库分析乳腺癌中SPNS2与相关蛋白质之间的相互作用。分析京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)数据库中得到的差异基因富集的信号通路。提取正常乳腺上皮细胞和乳腺癌细胞系RNA,通过RT-qPCR实验比较SPNS2的表达水平。结果在TCGA乳腺癌数据库中,SPNS2在乳腺癌组织中表达水平显著低于癌旁组织(P<0.001),SPNS2 mRNA的表达与T、M分期、病理分期、PAM50分型、年龄和组织学类型等因素相关(P<0.05);Cox分析表明年龄>60岁、T4期、M1期等因素是乳腺癌发生预后不良的风险因素(P<0.01);Kaplan-Meier分析显示低表达SPNS2乳腺癌患者具有更长的疾病特异生存期(disease-specific survival,DSS)和无进展间隔期(progression-free interval,PFI)(P<0.05);ROC曲线提示SPNS2诊断具有较好的敏感性和特异性。TIMER数据库分析显示在Luminal型乳腺癌中,SPNS2与CD4+T细胞,巨噬细胞、中性粒细胞等免疫细胞呈正相关(P<0.05)。STRING和KEGG数据库分析表明SPNS2相关蛋白富集于细胞周期和PPAR信号传导等途径(P<0.05)。RT-qPCR实验结果显示与正常乳腺上皮细胞相比,SPNS2在乳腺癌细胞系中低表达(P<0.001)。结论SPNS2是一种潜在的诊断乳腺癌和评价预后的生物学标志物。

Sphingosine-1-Phosphate Protects Against the Development of Cardiac Remodeling via Sphingosine Kinase 2 and the S1PR2/ERK Pathway

Objective:Cardiac remodeling is a common pathological change in various cardiovascular diseases and can ultimately result in heart failure.Thus,there is an urgent need for more effective strategies to aid in cardiac protection.Our previous work found that sphingosine-1-phosphate(S1P)could ameliorate cardiac hypertrophy.In this study,we aimed to investigate whether S1P could prevent cardiac fibrosis and the associated mechanisms in cardiac remodeling.Methods:Eight-week-old male C57BL/6 mice were randomly divided into a sham,transverse aortic constriction(TAC)or a TAC+S1P treatment group.Results:We found that S1P treatment improved cardiac function in TAC mice and that the cardiac fibrosis ratio in the TAC+S1P group was significantly lower and was accompanied by a decrease inα-smooth muscle actin(α-SMA)and collagen type I(COL I)expression compared with the TAC group.We also found that one of the key S1P enzymes,sphingosine kinase 2(SphK2),which was mainly distributed in cytoblasts,was downregulated in the cardiac remodeling case and recovered after S1P treatment in vivo and in vitro.In addition,our in vitro results showed that S1P treatment activated extracellular regulated protein kinases(ERK)phosphorylation mainly through the S1P receptor 2(S1PR2)and spurred p-ERK transposition from the cytoplasm to cytoblast in H9c2 cells exposed to phenylephrine.Conclusion:These findings suggest that SphK2 and the S1PR2/ERK pathway may participate in the anti-remodeling effect of S1P on the heart.This work therefore uncovers a novel potential therapy for the prevention of cardiac remodeling.

FHL2通过SK-1/S1P通路改善高糖诱导内皮细胞功能障碍的机制研究

目的探讨四个半LIM结构域蛋白2(FHL2)对高糖引起内皮细胞功能障碍的影响及其作用机制。方法采用MTT检测含不同浓度葡萄糖培养基培养下的人脐静脉内皮细胞(HUVECs)的细胞活力。将HUVECs分为对照组(5 mmol/L葡萄糖)、高糖组(30 mmol/L葡萄糖)、siNC组(30 mmol/L葡萄糖+siNC)和siFHL2组(30 mmol/L葡萄糖+siFHL2)。利用Western blot检测对照组和高糖组的HUVECs中FHL2蛋白表达水平。采用实时定量PCR法检测转染siFHL2后FHL2的表达水平。运用Annexin V-FITC/PI双染检测各组细胞凋亡情况。利用Western blot检测凋亡相关蛋白FHL2、B淋巴细胞瘤-2(Bcl-2)、Bcl-2相关X蛋白(Bax)、cleaved caspase 3表达水平。采用成管实验检测各组HUVECs的成管能力。利用Western blot检测各组SK-1/1-磷酸鞘氨醇(SK-1/S1P)通路中的蛋白表达水平,酶联免疫吸附(ELISA)检测S1P表达水平变化。结果与对照组相比,高糖组HUVECs内FHL2表达上调(t=4.407,P<0.05)。与对照组相比,高糖组HUVECs凋亡水平升高,Bax和cleaved caspase 3的表达也较对照组显著上调,而下调FHL2表达后,细胞凋亡减少,凋亡相关蛋白Bax和cleaved caspase 3的表达下调(P<0.05)。此外,FHL2表达下调改善了HUVECs的成管能力。分子机制分析显示,与对照组比较,高糖组p-SK-1表达显著下调(P<0.05),而下调FHL2后p-SK-1水平显著上调(P<0.05),S1P水平也显著上调(P<0.05)。结论FHL2可改善高糖引起的内皮细胞功能障碍,其作用机制可能与SK-1/S1P信号通路有关。

Increased endothelin receptor B and G protein coupled kinase-2 in the mesentery of portal hypertensive rats

AIM: To elucidate the mechanisms of mesenteric vasodilation in portal hypertension (PHT), with a focus on endothelin signaling. METHODS: PHT was induced in rats by common bile duct ligation (CBDL). Portal pressure (PP) was measured directly via catheters placed in the portal vein tract. The level of endothelin-1 (ET-1) in the mesenteric circulation was determined by radioimmunoassay, and the expression of the endothelin A receptor (ETAR) and endothelin B receptor (ETBR) was assessed by immunofluorescence and Western blot. Additionally, expression of G protein coupled kinase-2 (GRK2) and β-arrestin 2, which influence endothelin receptor sensitivity, were also studied by Western blot. RESULTS: PP of CBDL rats increased significantly (11.89 ± 1.38 mmHg vs 16.34 ± 1.63 mmHg). ET-1 expression decreased in the mesenteric circulation 2 and 4 wk after CBDL. ET-1 levels in the systemic circulation of CBDL rats were increased at 2 wk and decreased at 4 wk. There was no change in ETAR expression in response to CBDL; however, increased expression of ETBR in the endothelial cells of mesenteric arterioles and capillaries was observed. In sham-operated rats, ETBR was mainly expressed in the CD31+ endothelial cells of the arterioles. With development of PHT, in addition to the endothelial cells, ETBR expression was noticeably detectable in the SMA+ smooth muscle cells of arterioles and in the CD31+ capillaries. Following CBDL, increased expression of GRK2 was also found in mesenteric tissue, though there was no change in the level of β-arrestin 2. CONCLUSION: Decreased levels of ET-1 and increased ETBR expression in the mesenteric circulation following CBDL in rats may underlie mesenteric vasodilation in individuals with PHT. Mechanistically, increased GRK2 expression may lead to desensitization of ETAR, as well as other vasoconstrictors, promoting this vasodilatory effect.

S1PR2在大鼠慢性根尖周炎模型中的表达

目的:探讨1-磷酸鞘氨醇-2型受体(S1PR2)在大鼠慢性根尖周炎病变过程中的表达变化。方法:选取20只SD大鼠,随机处死4只作为0 d观察对象;在其余大鼠的下颌第一磨牙开髓建立根尖周炎模型,并在7 d、14 d、21 d和28 d随机处死4只;大鼠根尖组织行苏木精—伊红(HE)染色,抗酒石酸酸性磷酸酶(TRAP)染色检测破骨细胞;实时荧光定量聚合酶链式反应(RTqPCR)检测S1PR2、核因子-κB受体活化因子配体(RANKL)、骨保护素(OPG)的表达量。结果:HE染色显示:0 d根尖未见明显异常,7 d少量炎细胞浸润,14 d炎细胞浸润增多,21 d骨组织溶解增加,28 d炎症细胞浸润明显。RT-qPCR结果显示:0~28 d S1PR2的m RNA表达量逐渐升高,7 d、14 d、21 d和28 d均高于0 d(P<0.05),RANKL表达量在0~21 d逐渐增加,21 d达到最高峰,28 d时降低,7 d、14 d、21 d和28 d均高于0 d(P<0.05);OPG表达量在0~14 d逐渐降低,14 d时达到最低值,14~28 d又升高,0 d、7 d和28 d均高于14 d(P<0.05)。TRAP染色结果显示:破骨细胞与RANKL表达趋势一致。S1PR2与RANKL表达量、破骨细胞数呈正相关关系(P<0.05),RANKL与OPG表达量呈负相关关系(P<0.05)。结论:S1PR2的mRNA表达量随根尖周炎的发展而升高,提示其可能参与了慢性根尖周炎的发生、发展。

老年男性初发2型糖尿病患者鞘氨醇-1-磷酸与骨代谢的相关性

目的 探讨鞘氨醇-1-磷酸(sphingosine-1-phosphate, S1P)与骨转换标志物、骨密度和骨折发生风险的相关性。方法 纳入59例老年男性初发2型糖病患者作为2型糖尿病(type 2 diabetes mellitus, T2DM)组,49例非糖尿病居民作为非糖尿病(non diabetes mellitus, NDM)组,收集临床资料,采集静脉血,检查骨密度,计算FRAX评分,比较两组一般资料、糖脂代谢和骨代谢生化指标、骨密度、骨折发生风险及S1P水平的差异,分析S1P与骨转换标志物、骨折发生风险和糖代谢指标的相关性。结果 与NDM组比较,T2DM组空腹血糖(fasting plasma glucose, FPG)、糖化血红蛋白(glycosylated hemoglobin Alc, HbAlc)、游离脂肪酸(free fatty acids, FFA)显著升高(P<0.01),总胆固醇(total cholesterol, TC)、甘油三酯(triglycerides, TG)、低密度脂蛋白胆固醇(low density lipoprotein cholesterol, LDL-C)、高密度脂蛋白胆固醇(high density lipoprotein cholesterol, HDL-C)差异无统计学意义(P≥0.05);T2DM组甲状旁腺激素(parathyroid hormone, PTH)显著降低(P<0.01),钙(calcium, Ca)、磷(phosphorus, P)差异无统计学意义(P≥0.05);T2DM组骨钙素(osteocalcin, OC)、骨型碱性磷酸酶(bone alkaline phosphatase, BALP)、β-Ⅰ型胶原C端肽(β cross-linked c-telopeptide, β-CTX)显著降低(P<0.01),Ⅰ型胶原氨基端延长肽(procollagen type 1 n-terminal propetide, PlNP)、抗酒石酸酸性磷酸酶-5b(tartrate-resistant acid phosphatase-5b, TRACP-5b)和不同部位骨密度差异无统计学意义(P≥0.05);T2DM组10年内主要骨质疏松性骨折风险FRAX评分(FRAX 10-year major osteoporotic fracture risk score, FRAXM)和10年内髋部骨折风险FRAX评分(FRAX 10-year hip fracture risk score, FRAXH)显著升高(P<0.01);T2DM组血清S1P显著高于NDM组(P<0.01)。NDM组S1P与TRACP-5b呈正相关(P<0.05);T2DM组S1P与5种传统骨代谢标志物均无相关性(P≥0.05)。两组血清S1P与骨密度、FRAXM和FRAXH均无相关性(P≥0.05)。两组血清S1P与FPG和HbAlc均无相关性(P≥0.05)。结论 老年男性T2DM组血清S1P水平升高,S1P与传统骨转换标志物、骨密度、FRAXM和FRAXH无相关性。NDM组血清S1P与TRACP-5b呈正相关。

上调LncRNA FEZF1-AS1通过miR-363-3p/Sphk2信号轴促进宫颈癌细胞的机制

目的探讨LncRNA FEZF1-AS1对宫颈癌细胞增殖、侵袭及上皮间充质转化(EMT)的影响及作用机制。方法实时荧光定量PCR分析宫颈癌组织、癌旁正常组织、Hela、H8细胞中LncRNA FEZF1-AS1、miR-363-3p和Sphk2的表达;siRNA FEZF1-AS1转染Hela细胞,MTT、细胞侵袭实验及Western blot检测下调FEZF1-AS1对Hela细胞增殖、侵袭和EMT的影响。miRanda软件分析LncRNA FEZF1-AS1和miR-363-3p之间的靶向关系,双荧光素酶报告基因实验检测二者的相关性。下调miR-363-3p表达,分析Hela细胞增殖、侵袭和EMT。同时上调LncRNA FEZF1-AS1和miR-363-3p表达,检测LncRNA FEZF1-AS1通过miR-363-3p对Hela细胞增殖、侵袭和EMT的影响。TargetScan分析miR-363-3p和Sphk2之间的靶向关系,双荧光素酶报告基因实验检测miR-363-3p和Sphk2相关性。siRNA Sphk2转染Hela细胞,检测Hela细胞增殖、侵袭和EMT能力。结果与H8细胞相比,Hela细胞中LncRNA FEZF1-AS1、Sphk2表达上调(P<0.01),miR-363-3p表达下调(P<0.01)。下调LncRNA FEZF1-AS1表达明显抑制了Hela细胞增殖、侵袭与EMT;LncRNA FEZF1-AS1靶向miR-363-3p;下调miR-363-3p促进Hela细胞增殖、侵袭与EMT;上调LncRNA FEZF1-AS1通过miR-363-3p促进Hela细胞增殖、侵袭与EMT。miR-363-3p与Sphk2具有靶向关系。下调Sphk2表达抑制了Hela细胞增殖、侵袭与EMT。结论上调LncRNA FEZF1-AS1通过miR-363-3p/Sphk2轴促进Hela细胞增殖、侵袭及其EMT。

急性缺血性脑卒中患者血清Kruppel样转录因子2水平表达与脑梗死体积及预后的相关性研究

目的 研究急性缺血性脑卒中(acute ischemic stroke,AIS)患者血清Kruppel样转录因子2(kruppel-like factor 2,KLF2)水平表达与脑梗死体积及预后的关系,探讨KLF2对AIS脑梗死体积及预后不良的预测价值,并分析KLF2诱导AIS发生的可能机制。方法 收集2021年4月~2022年11月在空军军医大学第二附属医院收治的141例AIS患者为研究对象,并收集同期行健康体检者50例作为对照。根据Pullicino公式计算AIS脑梗死体积,分为小梗死灶组、中梗死灶组和大梗死灶组;根据改良Rankin量表(modified rankin scale,mRS)评分分为预后良好组和预后不良组;采用Pearson相关性分析血清KLF2表达与AIS患者脑梗死体积、预后及白细胞介素6(interleukin-6,IL-6)、鞘氨醇激酶1(sphingosine kinase 1,SphK1)和鞘氨醇-1-磷酸(sphingosine-1-phosphate,S1P)表达的相关性;绘制ROC曲线评估血清KLF2对AIS预后不良的预测价值。结果 AIS组患者血清KLF2(194.37±32.37pg/ml)水平显著低于对照组(242.85±17.39pg/ml);IL-6(13.70±2.89pg/ml),S1P(432.58±101.37pg/ml)和SphK1(2.65±0.58pg/ml)水平显著高于对照组(9.92±2.45pg/ml,259.15±78.24pg/ml,1.48±0.36 pg/ml),差异具有统计学意义(t=10.076,-8.253,-10.986,-13.367,均P <0.05)。小梗死灶组、中梗死灶组和大梗死灶组血清KLF2水平分别为217.69±33.14pg/ml,196.48±29.53pg/ml和168.94±31.62pg/ml,差异有统计学意义(F=25.753,P<0.001)。AIS预后良好组血清KLF2水平为211.83±28.46pg/ml,明显高于预后不良组的170.12±25.34pg/ml,差异有统计学意义(t=8.982,P<0.001)。血清KLF2水平与AIS脑梗死体积、预后及IL-6,SphK1水平呈负相关性(r=-0.607,-0.586,-0.480,-0.522,均P<0.05),与S1P水平无明显相关性(r=0.172,P>0.05);血清SphK1与S1P水平呈明显正相关(r=0.480,P<0.05)。血清KLF2预测AIS脑梗死体积(中~大梗死灶)和预后不良的AUC值分别为0.871和0.889,当截断值分别取206.1 pg/ml和192.37 pg/ml时,诊断灵敏度和特异度较高。结论 AIS血清中KLF2表达降低与患者脑梗死体积及预后关系密切,可作为AIS病情评估及判断预后不良的有效生物指标。血清KLF2表达与IL-6,SphK1水平存在明显相关性,KLF2可能调控SphK1/S1P途径参与神经炎症反应,介导AIS发生、发展,为临床研究及治疗提供了新的靶标。

线粒体神经酰胺酶通过其下游代谢产物1-磷酸鞘氨醇,上调K562细胞Bcl-2蛋白表达水平

目的:将线粒体神经酰胺酶(mtCDase)转染到K562细胞,观察线粒体神经酰胺酶的细胞生物学效应。方法:以脂质体介导将含有mtCDase cDNA的pCDNA3·1/His-CDase质粒转染到K562细胞,G418筛选阳性克隆,建立稳定表达mtCDase的K562TC细胞株。AnnexinⅤ/PI法、FCM及Western印迹法分别检测K562与K562TC细胞在无血清培养耐受性及Bcl-2蛋白表达水平方面的差异。结果:稳定表达mtCDase的K562TC细胞Bcl-2蛋白水平明显升高,抗血清剥夺能力明显增强。以硫代反义寡核苷酸特异性封闭K562TC细胞mtCDase,Bcl-2蛋白表达水平下调;二甲基鞘氨醇(DMS,鞘氨醇激酶抑制剂,降低细胞内1-磷酸鞘氨醇水平)同样下调K562TC细胞Bcl-2蛋白表达水平,而外源性1-磷酸鞘氨醇(SPP)显著上调K562细胞Bcl-2表达水平。结论:mtCDase转染K562细胞导致Bcl-2蛋白表达水平升高及无血清培养耐受能力增强。这种效应是通过mtCDase的下游代谢产物-SPP产生的。本研究证实mtCDase通过其下游代谢产物代谢SPP,上调K562细胞Bcl-2蛋白表达水平。

SPK1通过调节Bcl-2/Bax途径干扰LLC细胞凋亡

目的:研究鞘氨醇激酶1(SPK1)是否通过调节Bcl-2/Bax途径干扰小鼠Lewis肺癌(LLC)细胞的凋亡。方法:通过构建SPK1基因小干扰RNA(siRNA)真核表达载体,将siRNA转染至LLC细胞,在荧光显微镜下观察LLC细胞转染的情况。采用流式细胞术检测转染后LLC细胞的凋亡率,Western blot法检测转染后LLC细胞中SPK1、Bcl-2和Bax蛋白表达水平,ELISA法检测Bax和Bcl-2的蛋白表达。结果:转染后的LLC细胞在荧光显微镜下发出绿色荧光。siRNA-SPK1组细胞凋亡明显高于siRNA-SPK1-Neg组(P<0.01)。Western blot结果显示, siRNA-SPK1组中Bax蛋白表达明显较siRNA-SPK1-Neg组高,Bcl-2蛋白表达较siRNA-SPK1-Neg组低。ELISA结果显示siRNA-SPK1组中Bax表达水平显著高于siRNA-SPK1-Neg组(P<0.01), siRNA-SPK1组中Bcl-2表达水平显著低于siRNA-SPK1-Neg组(P<0.01)。结论:SPK1在LLC细胞中的表达与细胞凋亡率有关。SPK1可能是通过Bcl-2/Bax途径干扰LLC细胞凋亡。

鞘氨醇激酶1通过ERK1/2信号通路促进非小细胞肺癌细胞的侵袭和迁移

目的:探讨鞘氨醇激酶1(SphK1)对非小细胞肺癌(NSCLC)细胞迁移和侵袭的影响及其作用机制。方法:选取31例外科手术切除并经常规组织学检查确诊为NSCLC的肿瘤组织标本和配对癌旁肺组织标本,应用免疫组织化学染色和RT-qPCR检测SphK1的表达。将pcDNA3.1-SphK1载体(SphK1组)、空白pcDNA3.1载体对照(NC组)、SphK1 siRNA(siSphK1组)和对照siRNA(siNC组)分别转染人肺腺癌A549细胞,Western blot法检测SphK1、E-cadherin、fibronectin和p-ERK1/2的表达;利用Transwell实验评估过表达SphK1和抑制ERK1/2对A549细胞迁移和侵袭的影响。结果:SphK1在NSCLC组织中高表达,并与肿瘤分期相关。SphK1过表达可显著促进A549细胞的迁移和侵袭,提高p-ERK1/2和fibronectin蛋白水平,减少E-cadherin蛋白表达(P<0.05),而干扰SphK1则呈现相反的结果。ERK1/2抑制剂U0126可显著抑制SphK1过表达诱导的p-ERK1/2和fibronectin上调及E-cadherin下调,也抑制了SphK1过表达增强的A549细胞侵袭和迁移能力(P<0.05)。结论:SphK1可能通过ERK1/2通路降低E-cadherin蛋白水平、提高fibronectin蛋白水平,并促进NSCLC细胞的侵袭和迁移。

1-磷酸鞘氨醇受体2抑制脂多糖诱导的急性肺损伤

目的:探讨1-磷酸鞘氨醇受体2(S1P2R)对脂多糖(LPS)诱导的急性肺损伤(ALI)中的作用及机制。方法:野生小鼠和S1pr2-/-小鼠经气管滴注LPS,建立急性肺损伤动物模型。LPS注射24 h时观察肺组织的病理改变,测定支气管肺泡灌洗液(BALF)中的蛋白浓度、总细胞数、中性粒细胞的比值及TNF-α、IL-6细胞因子的表达。为了观察S1P2R在肺损伤中的作用机制,LPS注射10 min前野生小鼠和S1pr2-/-小鼠经尾静脉注射一氧化氮合酶抑制剂L-NAME,LPS注射12 h时,再观察肺的病理组织学变化以及BALF中的蛋白浓度,总细胞数及TNF-α、IL-6细胞因子表达的变化。结果:与野生小鼠比较,S1pr2-/-小鼠恶化LPS诱导的急性肺损伤,BALF中的蛋白浓度、总细胞数,中性粒细胞比值及炎症细胞因子表达显著增加。而L-NAME的预处理显著抑制在S1pr2-/-小鼠LPS诱导加重的急性肺损伤。结论:S1P2R通过抑制NO合成,维持血管屏障,从而抑制急性肺损伤。

免疫组化、Western blot蛋白印迹和免疫荧光染色观察磷酸鞘氨醇受体2大鼠海马中的表达变化

目的观察磷酸鞘氨醇受体2(S1PR2)基因在颞叶癫痫大鼠海马中的表达变化。方法将72只健康雄性Wistar大鼠随机均分为实验组(36例)和对照组(36例)。实验组使用氯化锂—匹罗卡品进行颞叶癫痫诱导制模,成功后持续大发作1h终止待检,对照组以相同剂量生理盐水注射,然后以进行免疫组化、Western blot印迹和免疫荧光染色检测并进行统计学分析。结果免疫组化检测结果显示,两组1d、3d、7d、28d、56d海马S1PR2阳性细胞计数相比有统计学意义(P<0.05);Western blot检测结果显示,两组3d、7d、28d、56d海马S1PR2蛋白表达水平相比有统计学意义(P<0.05);免疫荧光染色检测显示,S1PR2蛋白表达阳性为红色,星形胶质细胞为绿色,细胞核为蓝色。结论颞叶癫痫大鼠海马中S1PR2表达水平显著下降,说明颞叶癫痫发病机制可能与神经元功能、星形胶质细胞增生受到S1PR2影响有关。

SPHK1与MMP2蛋白在结肠癌组织中的表达及临床意义

目的探讨鞘氨醇激酶1(SPHK1)与基质金属蛋白酶2(MMP2)在人结肠癌组织中的表达及其与临床病理特征之间的关系。方法2014年1月至2018年12月于宝鸡市中心医院行结肠癌根治术患者共201例,使用免疫组织化学法检测SPHK1蛋白与MMP2蛋白在结肠癌组织中的表达情况,使用χ2检验分析其与临床各病理资料之间的关系。结果SPHK1蛋白在结肠癌组织中的表达率为54.7%,明显高于癌旁组织中的39.7%,差异具有统计学意义(P<0.05);SPHK1蛋白的高表达与患者的淋巴结是否转移、T分期、组织学分化程度以及是否血管侵犯有关(P<0.05);MMP2在结肠癌组织中的表达率为64.7%,明显高于癌旁组织中的24.4%,差异具有统计学意义(P<0.05);MMP2蛋白的高表达与淋巴结转移与否、T分期、M分期以及血管侵犯有关(P<0.05);SPHK1蛋白在结肠癌组织中的表达与MMP2蛋白呈正相关(r=0.352,P<0.05)。结论SPHK1蛋白与MMP2蛋白在人结肠癌组织中均异常表达,且可能参与到结肠癌的侵袭与转移过程中。

LDB2在肺癌组织中的表达及与S1PR1的相关性分析

目的探讨LIM域结合蛋白2(LDB2)在肺癌组织中的表达及其与1-磷酸神经鞘氨醇受体1(S1PR1)的相关性。方法选取2010年4月至2011年5月南通市肿瘤医院就诊的52例肺癌患者的癌组织作为实验组,相应的癌旁组织作为对照组。采用实时荧光定量PCR(qRT-PCR)检测两组LDB2及S1PR1基因的表达水平;通过Oncomine数据库对LDB2的表达结果进行验证,并分析其与临床病理参数之间的关系;绘制ROC曲线,评价其对肺癌的诊断价值;利用Kaplan-Meier Plotter数据库分析其与肺癌预后的关系;同时检测其与S1PR1的相关性。结果LDB2基因在肺癌组织中的表达量为0.158(0.062,0.383),癌旁组织中表达量为0.403(0.261,0.711),两组间差异具有统计学意义(U=700.0,P<0.01)。Oncomine数据库共检索出9项符合筛选条件的研究,其LDB2基因均呈低表达(P<0.01)。肺癌组织中LDB2基因的表达与性别、年龄、吸烟情况、病理类型、肿瘤大小、TNM分期及是否淋巴结转移均无关(P>0.05)。ROC曲线分析结果表明,当ROC曲线下面积(AUC ROC)为0.741(95%CI:0.643~0.839),cut-off值取0.247时,LDB2筛查肺癌的敏感性为80.8%,特异性为61.5%。Kaplan-Meier生存分析发现,低表达LDB2患者的5年总生存期显著低于高表达患者(P<0.01)。S1PR1基因在肺癌组织中表达量为0.710(0.337,1.523),在癌旁组织中的表达量为1.582(0.913,3.533),两组间差异具有统计学意义(U=780.0,P<0.01),且肺癌组织中LDB2与S1PR1的表达水平呈正相关(r=0.827,P<0.01)。结论LDB2及S1PR1在肺癌中均低表达且呈强相关性,两者在肺癌的发生、发展中具有重要的作用。