山姜素调节VEGF/SphK1/S1P信号通路对膝骨关节炎大鼠血管生成的影响

目的探讨山姜素(APT)调节血管内皮生长因子/鞘氨醇激酶1/1磷酸鞘氨醇(VEGF/SphK1/S1P)信号通路对膝骨关节炎(KOA)大鼠血管生成的影响。方法采用改良的Videman法构建KOA大鼠模型,将90只大鼠分为对照组(Control组)、模型组(Model组)、山姜素低剂量组(L-APT组)、山姜素高剂量组(H-APT组)、山姜素高剂量组+慢病毒阴性对照组(APT+NC组)、山姜素高剂量组+过表达SphK1慢病毒组(APT+SphK1组),每组15只。HE染色观察大鼠软骨组织病理变化;酶联免疫吸附试验测定软骨组织白细胞介素(IL)-1β、肿瘤坏死因子α(TNF-α)、IL-6、基质金属蛋白酶-13(MMP-13)水平;TUNEL检测软骨组织细胞凋亡情况;免疫组化检测血管内皮生长因子(VEGF)、CD31蛋白表达情况;Western blot检测血管内皮生长因子受体2(VEGFR2)、磷酸化VEGFR2(p-VEGFR2)、SphK1、S1P蛋白水平。结果与Control组比较,Model组大鼠出现病理损伤,细胞凋亡率、IL-1β、TNF-α、IL-6、MMP-13、VEGF阳性表达、CD31阳性表达和p-VEGFR2、SphK1、S1P蛋白表达水平增加(P<0.05);与Model组比较,L-APT组、H-APT组病理损伤明显减轻,细胞凋亡率、IL-1β、TNF-α、IL-6、MMP-13、VEGF阳性表达、CD31阳性表达和pVEGFR2、SphK1、S1P蛋白表达水平降低(P<0.05);与APT+NC组比较,APT+SphK1组软骨组织病理损伤加重,细胞凋亡率、IL-1β、TNF-α、IL-6、MMP-13、VEGF阳性表达、CD31阳性表达和p-VEGFR2、SphK1、S1P蛋白表达水平增加(P<0.05)。结论APT通过抑制VEGF/SphK1/S1P信号通路抑制KOA大鼠血管生成。

阿芬太尼调节SphK1/S1P信号通路保护心肌缺血再灌注损伤大鼠

[目的]探究阿芬太尼对心肌缺血再灌注损伤(MIRI)大鼠的作用及在该过程中对鞘氨醇激酶1(SphK1)/鞘氨醇-1-磷酸(S1P)信号通路的调节机制。[方法]将SPF级SD雄性大鼠随机分为假手术组、模型组、阳性药物组(复方丹参组)和阿芬太尼低剂量组、阿芬太尼高剂量组、阿芬太尼高剂量+SphK1激动剂组(阿芬太尼+PMA组),每组20只。除假手术组,其余组均利用结扎左前降支冠状动脉后再灌注复制MIRI模型。全自动生物化学分析仪检测血清乳酸脱氢酶(LDH)、肌酸激酶(CK)和谷草转氨酶(AST)的活性;TTC检测大鼠心肌梗死面积;HE染色观察大鼠心肌组织形态学特征;TUNEL染色检测大鼠心肌细胞凋亡;ELISA检测血清肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)、白细胞介素1β(IL-1β)及S1P的水平;试剂盒检测心肌组织中丙二醛(MDA)含量和超氧化物歧化酶(SOD)的活性;Western blot检测心肌组织SphK1蛋白表达。[结果]相较于假手术组,模型组大鼠心肌组织病理损伤严重,血清中心肌损伤标志物LDH、CK和AST的活性,心肌梗死面积和心肌细胞凋亡率,TNF-α、IL-6、IL-1β、MDA、S1P水平及SphK1蛋白表达均升高,SOD活性降低(P<0.05);相较于模型组,阳性药物组和阿芬太尼低、高剂量组大鼠心肌组织损伤减轻,血清中心肌损伤标志物LDH、CK和AST的活性,心肌梗死面积和心肌细胞凋亡率,TNF-α、IL-6、IL-1β、MDA、S1P水平及SphK1蛋白表达均降低,SOD活性升高(P<0.05)。SphK1激动剂可逆转高剂量阿芬太尼对上述指标的影响(P<0.05)。[结论]阿芬太尼对MIRI大鼠发挥保护作用,其机制可能与抑制SphK1/S1P信号通路有关。

Role of sphingosine kinases and sphingosine 1-phosphate in mediating adipogenesis

Recent Background: Development of obesity involves promotion of preadipocyte differrentiation. This study investigated the role that sphingosine kinases (SPHK) and ceramide-derived sphingosine 1-phosphate (S1P) play in adipocyte terminal differentiation. Materials and Methods: The mouse 3T3-L1 cell line was used as a model for adipogenesis. Cells were harvested at specific time points after initation of differentiation, and SPHK activity was measured. 3T3-L1 cells were treated with S1P and expression of early adipogenesis transcription markers was measured by real time PCR. The expression of S1P-receptors (S1PRs) during differentiation was measured. Results: SPHK activity is induced when 3T3-L1 cells are treated with insulin, dexamethasone, and isobutylmethylxanthine to induce differentiation. SPHK1 is active in preadipocytes and early in the differentiation process. Both SPHK1 and SPHK2 isozymes contribute to activity in differentiated adipocytes. Inhibition of SPHK1 attenuates adipocyte differentiation;however, extracellular S1P does not rescue the effect of SPHK1 inhibition on adipogenesis. Although treatment of preadipocytes with S1P induced message expression of the early adipogenesis transcription factor CC AAT/ binding proteinalpha, continued treatment did not fully support the development of differentiated adipocytes. Sphingosine 1-phosphate receptors (S1PRs) are expressed in preadipocytes and message expression declines markedly during adipocyte differentiation. Conclusion: These results demonstrate that the contribution of SPHK and S1P to adipogenesis is mediated primarily through biphasic activation of SPHK1 and 2 with extracellular S1P and S1PRs playing little role during preadipocyte differentiation.

白藜芦醇通过调控microRNA-506/sphingosine kinase 1抑制非小细胞肺癌细胞的增殖及促进其凋亡

目的:探讨白藜芦醇对A549细胞增殖、细胞周期及凋亡的影响及机制。方法:实验分为空白对照组、白藜芦醇干预组,miR-506-inhibitor组及白藜芦醇干预miR-506-inhibitor组。CCK-8法检测A549细胞增殖;流式细胞术检测A549的细胞周期及凋亡;qRT-PCR检测miR-506表达及SPHK1的mRNA表达;Western blot法检测SPHK1的蛋白表达。结果:白藜芦醇抑制A549细胞的增殖,使G0-G1期的细胞数量增加,S期的细胞数量减少并且诱导A549细胞的凋亡。白藜芦醇上调miR-506的表达及下调SPHK1的表达。结论:白藜芦醇通过调控miR-506/SPHK1轴从而抑制A549细胞的增殖并且诱导其凋亡。

SphK/S1P在心血管疾病中的作用

磷酸鞘氨醇(S1P)是一种活性高的膜磷脂类代谢物,对心血管系统具有重要的生理作用。鞘氨醇激酶(SphK)是一种脂肪酶,对维持体内S1P水平的稳定非常重要。S1P通过催化调节与细胞表面的G蛋白偶联受体(S1PR1-5)的结合,从而在心血管疾病中发挥不同的生理学效应,如参与调控动脉粥样硬化、心肌缺血再灌注损伤、心肌梗死、心力衰竭等疾病的发生发展,维持血管内皮细胞屏障功能,保护内皮糖萼层,白细胞黏附以及炎性反应等生理病理过程。

松萝酸通过调节SphK1/S1P信号通路减轻缺氧/复氧诱导的心肌细胞损伤

目的 探讨松萝酸(UA)对缺氧/复氧(H/R)诱导的心肌细胞损伤的影响及其作用机制。方法 构建H9c2细胞H/R模型,使用0.5~64μmol/L UA分别预处理H9c2细胞,MTT法筛选UA浓度;H9c2细胞随机分为对照组、模型组、UA低剂量组(1μmol/L)、UA中剂量组(4μmol/L)、UA高剂量组(16μmol/L)和UA高剂量+Benzyl butyl phthalate(BBP)组(16μmol/L UA+100 nmol/L BBP),检测各组细胞增殖活力、细胞凋亡情况,白介素(IL)-1β、IL-6、丙二醛(MDA)、超氧化物歧化酶(SOD)、腺嘌呤核苷三磷酸(ATP)、鞘氨醇激酶1(SphK1)、鞘氨醇-1-磷酸受体1(S1PR1)、细胞外调节蛋白激酶1/2(ERK1/2)蛋白表达水平。结果 1μmol/L以上浓度UA可以显著提高H/R H9c2细胞增殖活力。与对照组相比,模型组细胞增殖能力和ATP、SOD含量下降,细胞凋亡率和IL-1β、IL-6、MDA、SphK1、S1PR1、ERK1/2表达增加(P<0.05);与模型组相比,UA低、中、高剂量组细胞增殖能力和ATP、SOD含量上升,细胞凋亡率和IL-1β、IL-6、MDA、SphK1、S1PR1、ERK1/2表达下降,干预效果呈浓度依赖性(P<0.05);BBP完全沉默UA对H/R诱导的心肌细胞的治疗作用。结论 UA减轻H/R H9c2细胞损伤与其抑制SphK1/S1P信号通路有关。

Inhibition of sphingosine kinase 1 ameliorates acute liver failure by reducing high-mobility group box 1 cytoplasmic translocation in liver cells

AIM: To determine the therapeutic potential of sphingosine kinase 1(Sphk1) inhibition and its underlying mechanism in a well-characterized mouse model of D-galactosamine(D-Gal N)/lipopolysaccharide(LPS)-induced acute liver failure(ALF).METHODS: Balb/c mice were randomly assigned to different groups,with ALF induced by intraperitoneal injection of D-Ga IN(600 mg/kg) and LPS(10 μg/kg). The Kaplan-Meier method was used for survival analysis. Serum alanine aminotransferase(ALT) and aspartate aminotransferase(AST) levels at different time points within one week were determined using a multi-parametric analyzer. Serum high-mobility group box 1(HMGB1),tumor necrosis factor-α(TNF-α),interleukin(IL)-1β,IL-6,IL-10,and sphingosine-1-phosphate were detected by enzyme-linked immunosorbent assay. Hepatic morphological changes at 36 h after acute liver injury induction were assessed by hematoxylin and eosin staining. HMGB1 expression in hepatocytes and cytoplasmic translocation were detected by immunohistochemistry. Expression of Sphk1 in liver tissue and peripheral blood mononuclear cells(PBMCs) was analyzed by Western blot.RESULTS: The expression of Sphk1 in liver tissue and PBMCs was upregulated in Gal N/LPS-induced ALF. Upregulated Sphk1 expression in liver tissue was mainly caused by Kupffer cells,the resident macrophages of the liver. The survival rates of mice in the N,Ndimethylsphingosine(DMS,a specific inhibitor of Sph K1) treatment group were significantly higher than that of the control group(P < 0.001). DMS treatment significantly decreased the levels of serum ALT and AST at 6,12,and 24 h compared with that of the control group(P < 0.01 for all). Serum HMGB1 levels at 6,12,and 24 h,as well as serum TNF-α,IL-6,and IL-1β levels at 12 h,were significantly lower in the DMS treatment group than in the control group(P < 0.01 for all). Furthermore,hepatic inflammation,necrosis,and HMGB1 cytoplasm translocation in liver cells were significantly decreased in the DMS treatment group compared to the control group(43.72% ± 5.51% vs 3.57% ± 0.83%,χ2 = 12.81,P < 0.01).CONCLUSION: Inhibition of Sph K1 ameliorates ALF by reducing HMGB1 cytoplasmic translocation in liver cells,and so might be a potential therapeutic strategy for this disease.

SPHK1靶向NF-κB信号通路调控胃癌细胞的迁移与侵袭

目的探讨鞘氨醇激酶-1(SPHK1)在胃癌(GC)组织中的表达及其靶向核因子-κB(NF-κB)调控GC细胞迁移和侵袭能力的分子机制。方法基于TIMER2.0、GEPIA与HPA数据库分析SPHK1在GC组织中的表达。使用Kaplan-Meier Plotter数据库预测SPHK1与GC患者预后的关联。利用IHC检测GC及癌旁组织中SPHK1和MKI67的表达并分析两者相关性。运用Western blotting与qRT-PCR检测GC各细胞系中SPHK1蛋白及mRNA水平。基因富集通路数据库检索SPHK1对GC进展的生物学功能。使用慢病毒敲低HGC-27/过表达MGC-803细胞中SPHK1的表达;采用细胞划痕实验探究SPHK1对GC细胞迁移能力的影响;Transwell实验探究SPHK1对GC细胞迁移和侵袭能力的作用;通过Western blotting检测各蛋白表达情况。体内成瘤实验中,将裸鼠随机分为shNC组、shSPHK1组、oeNC组与oeSPHK1组,利用稳转株验证SPHK1的促癌作用。结果生物信息学表明SPHK1在GC组织中显著高表达(P<0.001);同时高表达的SPHK1预示着较差的总生存期(P<0.001)和进展后总生存期(P<0.001)以及更差的无复发生存期(P<0.001)。IHC结果表明GC组织中SPHK1与MKI67表达明显上调(P<0.001)且呈正相关(P<0.001)。基因富集通路数据库提示,SPHK1参与GC中的细胞黏附、迁移及血管生成等,且NF-κB参与GC进展(P<0.05)。细胞实验数据显示,抑制SPHK1减弱GC细胞的迁移和侵袭能力,而过表达SPHK1会产生相反的结果(P<0.01);SPHK1正向调节磷酸化P65(p-P65)、血管内皮生长因子(VEGFA)和白细胞介素(IL-17)蛋白表达(P<0.05);利用PDTC阻断NF-κB信号通路可削弱SPHK1促进的GC细胞迁移与侵袭能力以及各蛋白表达水平(P<0.01);动物实验表明,与NC组相比,shSPHK1组肿瘤大小和质量明显减小,而oeSPHK1组显著增加(P<0.001)。结论SPHK1可靶向NF-κB信号通路表达进而调控GC细胞的迁移与侵袭,提示SPHK1可能是GC进展的潜在诊断分子标志物。

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

AIM: To examine the expression of SphK1, 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 mRNA expression of SphK1, LPAR2, and the three major S1P receptors in 27 colorectal cancer samples and corresponding normal tissue samples. We also examined the correlation between the expression of SphK1 and LPAR2.RESULTS: Colorectal cancer tissue in 22 of 27 patients had higher levels of SphK1 mRNA than in normal tissue. In two-thirds of the samples, SphK1 mRNA expression was more than two-fold higher than in normal tissue. Consistent with previous reports, LPAR2 mRNA expression in 20 of 27 colorectal cancer tissue samples was higher compared to normal tissue samples. Expression profiles of all three major S1P 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 SphK1 and LPAR2 expression [Pearson&#x02019;s correlation coefficient (r) = 0.784 and P &#x0003c; 0.01]. The mRNA levels of SphK1 and LPAR2 did not correlate with TNM stage.CONCLUSION: Our findings suggest that S1P and LPA may play important roles in the development of colorectal cancer via the upregulation of SphK1 and LPAR2, both of which could serve as new therapeutic targets in the treatment of colorectal cancer.

Sphingosine kinase 1 knockout alleviates hepatic ischemia/reperfusion injury by attenuating inflammation and oxidative stress in mice

Background: Hepatic ischemia/reperfusion(I/R) injury remains a significant problem in clinical practice. Sphingosine kinase 1(Sph K1) phosphorylates sphingosine to sphingosine-1-phosphate(S1 P) which participates in multiple bioactive processes. However, little is known about the role of Sph K1 in hepatic I/R injury. This study aimed to investigate the effect of Sph K1 knockout on liver I/R injury and to explore underlying mechanisms. Methods: Sph K1 knockout and wild type mice were subjected to 70% partial hepatic I/R. Serum alanine aminotransferase was determined to indicate the degree of liver damage. Hematoxylin-eosin staining and TUNEL assay were used to assess histological changes and hepatocellular apoptosis, respectively. Immunohistochemistry was performed to detect the expression and translocation of phosphorylated p65 and signal transducer and activator of transcription 3(STAT3). Western blotting was used to determine the expression of S1 P receptor 1(S1 PR1), phosphorylated p65 and STAT3. Real-time PCR was used to demonstrate the changes of proinflammatory cytokines. Oxidative stress markers were also determined through biochemical assays. Results: Sph K1 knockout significantly ameliorated I/R-induced liver damage, mitigated liver tissue necrosis and apoptosis compared with wild type control. I/R associated inflammation was alleviated in Sph K1 knockout mice as demonstrated by attenuated expression of S1 PR1 and reduced phosphorylation of nuclear factor kappa B p65 and STAT3. The proinflammatory cytokines interleukin-1 β, interleukin-6 and tumor necrosis factor-α were also inhibited by Sph K1 genetic deletion. The oxidative stress markers were lower in Sph K1 knockout mice after I/R injury than wild type mice. Conclusions: Knockout of Sph K1 significantly alleviated damage after hepatic I/R injury, possibly through inhibiting inflammation and oxidative stress. Sph K1 may be a novel and potent target in clinical practice in I/R-related liver injury.

KAI1 inhibits HGF-induced invasion of pancreatic cancer by sphingosine kinase activity

BACKGROUND:KAI1/CD82 has been reported to attenuate the process of metastases in a variety of tumors;however,its mechanism of action in invasion has not been fully elucidated. The present study aimed to investigate the importance of KAI1 in invasion and its correlation with activation of sphingosine kinase(SPK)in human pancreatic cancer PANC1 and Miapaca-2 cell lines. METHODS:The expression of KAI1 in PANC1 and Miapaca-2 cells,which was mediated by recombinant adenovirus(Ad-KAI1), was assessed by a flow cytometer and Western blotting.After successful infection was established,in vitro growth curve and invasive ability in Boyden Chamber assay were studied.The presence of KAI1 correlating with c-Met and SPK was detected by co-immunoprecipitation and[γ-32P]ATP incorporation. RESULTS:KAI1 genes had no significant effects on the curve representing cell growth.After infection with the KAI1 gene,decreased invasive ability in the Boyden Chamber assay was observed in PANC1 and Miapaca-2 cells that were induced by hepatocyte growth factor.Over-expression of KAI1 in the cells led to the deactivation of SPK and a decreased level of intracellular sphingosine-1-phosphate.No correlation was observed between c-Met and KAI1 during co-immunoprecipitation. CONCLUSION:The results of this study for the first time demonstrated a regulatory role for KAI1 in SPK activation, which leads to decreased invasive ability in disease progression of human pancreatic cancer.

Role of sphingosine kinase and sphingosine-1-phosphate in inflammatory arthritis

The importance of sphingosine kinase(SphK)and sphingosine-1-phosphate(S1P)in inflammation has been extensively demonstrated.As an intracellular second messenger,S1P plays an important role in calcium signaling and mobilization,and cell proliferation and survival.Activation of various plasma membrane receptors,such as the formyl methionyl leucyl phenylalanine receptor,C5a receptor,and tumor necrosis factor α receptor,leads to a rapid increase in intracellular S1P level via SphK stimulation.SphK and S1P are implicated in various chronic autoimmune conditions such as rheumatoid arthritis, primary Sjgren's syndrome,and inflammatory bowel disease.Recent studies have demonstrated the important role of SphK and S1P in the development of arthritis by regulating the pro-inflammatory responses.These novel pathways represent exciting potential therapeutic targets.

Regulatory role of sphingosine kinase and sphingosine-1-phosphate receptor signaling in progenitor/stem cells

Balanced sphingolipid signaling is important for the maintenance of homeostasis. Sphingolipids were demonstrated to function as structural components, second messengers, and regulators of cell growth and survival in normal and disease-affected tissues. Particularly, sphingosine kinase 1 (SphK1) and its product sphingosine-1-phosphate (S1P) operate as mediators and facilitators of proliferation-linked signaling. Unlimited proliferation (selfrenewal) within the regulated environment is a hallmark of progenitor/stem cells that was recently associated with the S1P signaling network in vasculature, nervous,muscular, and immune systems. S1P was shown to regulate progenitor-related characteristics in normal and cancerstemcells(CSCs) viaG-protein coupled receptorsS1Pn(n=1 to 5). The SphK/S1P axis is crucially involved in the regulation of embryonic development of vasculature and the nervous system, hematopoietic stem cell migration, regeneration of skeletal muscle, and development of multiple sclerosis. The ratio of the S1P receptor expression, localization, and specific S1P receptoractivated downstream effectors influenced the rate of selfrenewal and should be further explored as regeneration related targets. Considering malignant transformation,it is essential to control the level of self-renewal capacity.Proliferation of the progenitor cell should be synchronized with differentiation to provide healthy lifelong function of blood, immune systems, and replacement of damaged ordead cells. The differentiation-related role of SphK/S1P remains poorly assessed. A few pioneering investigations exploredpharmacologicaltoolsthattargetsphingolipid signaling and can potentially confine and direct self-renewal towards normal differentiation. Further investigation is required to test the role of the SphK/S1P axis in regulation of self-renewal and differentiation.

Sphk1抑制剂PF543对非小细胞肺癌细胞凋亡及增殖的影响

目的探讨鞘氨醇激酶1(Sphk1)抑制剂PF543对非小细胞肺癌A549细胞的凋亡和增殖的影响。方法体外培养并采集非小细胞肺癌细胞株A549,采用不同浓度的PF543处理并将其记为A组(0μmol·L^(-1))、B组(10μmol·L^(-1))、C组(20μmol·L^(-1)),另选取健康人体肺细胞作为对照组。使用逆转录聚合酶链反应(RT-PCR)检测各组的Sphk1表达水平。使用CCK8试剂盒检测在不同浓度PF543作用下,A549细胞的增殖能力;使用流式细胞仪检测在不同浓度PF543作用下,A549细胞的凋亡率;使用Western blot检测在不同浓度PF543作用下,A549细胞的Caspase-3、Ki67、Sphk1的相对表达水平。结果A组的Sphk1 mRNA表达水平高于对照组(P<0.05);B组和C组的Sphk1 mRNA表达水平均低于A组,且C组低于B组(P<0.05)。在同一培养时间下,与A组相比,B组和C组的肿瘤细胞生长抑制率均升高,且C组高于B组(P<0.05);在同一浓度下,培养时间越长,肿瘤细胞生长抑制率越高(P<0.05)。与A组相比,B组和C组的A549细胞凋亡率均升高,且C组低于B组(P<0.05)。与A组相比,B组和C组Caspase-3的相对表达水平均升高,且C组高于B组(P<0.05);B组和C组Ki67、Sphk1的相对表达水平均降低,且C组低于B组(P<0.05)。结论Sphk1在非小细胞肺癌中高表达,PF543可下调A549细胞中Sphk1的表达水平,并且可抑制A549细胞增殖以及促进A549细胞凋亡,其作用机制可能在于PF543可上调Caspase-3表达水平以促进细胞凋亡、下调Ki67表达水平以抑制细胞增殖。

Sphingosine kinase 1 dependent protein kinase C-δ activation plays an important role in acute liver failure in mice

AIM: To investigate the role of protein kinase C(PKC)-δ activation in the pathogenesis of acute liver failure(ALF) in a well-characterized mouse model of D-galactosamine(D-Gal N)/lipopolysaccharide(LPS)-induced ALF.METHODS: BALB/c mice were randomly assigned to five groups, and ALF was induced in mice by intraperitoneal injection of D-Ga IN(600 mg/kg) and LPS(10 μg/kg). Kaplan-Meier method was used for survival analysis. Serum alanine aminotransferase(ALT) and aspartate aminotransferase(AST) levels at different time points within one week were determined using a multiparameteric analyzer. Serum levels of high-mobility group box 1(HMGB1), tumor necrosis factor(TNF)-α, interleukin(IL)-1β, IL-6, and IL-10 as well as nuclear factor(NF)-κB activity were determined by enzyme-linked immunosorbent assay. Hepatic morphological changes at 36 h after ALF induction were assessed by hematoxylin and eosin staining. Expression of PKC-δ in liver tissue and peripheral blood mononuclear cells(PBMCs) was analyzed by Western blot.RESULTS: The expression and activation of PKC-δ were up-regulated in liver tissue and PBMCs of mice with D-Gal N/LPS-induced ALF. Inhibition of PKC-δ activation with rottlerin significantly increased the survival rates and decreased serum ALT/AST levels at 6, 12 and 24 h compared with the control group(P < 0.001). Rottlerin treatment also significantly decreased serum levels of HMGB1 at 6, 12, and 24 h, TNF-α, IL-6 and IL-1 β at 12 h compared with the control group(P < 0.01). The inflammatory cell infiltration and necrosis in liver tissue were also decreased in the rottlerin treatment group. Furthermore, sphingosine kinase 1(Sph K1) dependent PKC-δ activation played an important role in promoting NF-κB activation and inflammatory cytokine production in ALF.CONCLUSION: Sph K1 dependent PKC-δ activation plays an important role in promoting NF-κB activation and inflammatory response in ALF, and inhibition of PKC-δ activation might be a potential therapeutic strategy for this disease.

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.

Expressions of Sphingosine-1-phosphate (S1P) Receptors, Sphingosine Kinases in Malignant Bone and Soft Tissue Tumors, and The role of Sphingosine Kinase-1 in Growth of MFH Cell Lines

Sphingolipids are ubiquitous components of cell membranes. Their metabolites ceramide, sphingosine, and sphingosine-1-phosphate (S1P) have important physiological functions, including regulation of cell growth and survival. S1P is generated by phosphorylation of sphingosine catalyzed by sphingosine kinase-1 (SPHK1). The purpose of this study is to explore the roles of S1P, S1P receptors, and sphingosine kinases in malignant musculoskeletal tumors. Twenty-one tumor samples (7 liposarcomas, 3 chondrosarcomas, 6 osteosarcomas, 5 MFH) obtained at open biopsy, and four human MFH cell lines (Nara H, Nara F, TNMY1, GBS-1) were used. We examined the mRNA expression of S1P receptors by RT-PCR, and the expression levels of SPHK by Real-time PCR. We used 4 MFH cell lines to analyze SPHK1 proteins by Western blotting. SPHK1 siRNA was transfected into MFH cell lines by lipofection method. Cell proliferation (control and transfected with siRNA) was assayed using WST-8 (Cell Counting Kit-8) assay. All high grade malignant tumors expressed S1P1, S1P2, S1P3 receptors, whereas the expression of S1P1 receptor was detected in 50% of low-grade malignant tumors, S1P2 receptor in 30%, and S1P3 in 50%. No statistically significant difference was found in the expression level of SPHK1 between high-grade and low-grade malignant tumors by Real-time PCR. By results of Western blotting, proteins of SPHK1 were expressed in all MFH cell lines. In MFH cell lines, transfection with SPHK1 siRNA oligonucleotides resulted in approximately 50 to 80% suppression of SPHK1 mRNA expression as determined by real-time PCR. Down-regulation of SPHK1 with small interfering RNA significantly reduced SPHK1 protein levels by Western blotting. Knock down of SPHK1 expression significantly decreased cell proliferation of all MFH cells. These results suggest that the expression of S1P receptors may play an important role for cell proliferation and may correlate with histologic grade in malignant bone and soft tissue tumors, and that SPHK1 may be one of essential molecules for cell proliferation in MFH cell lines.

Research progress of sphingosine 1-phosphate and its signal transduction in central nervous system diseases

Sphingosine 1-phosphate(S1P),as a sphingolipid metabolite,has become a key substance in regulating various physiological processes,involved in differentiation,proliferation,migration,morphogenesis,cytoskeleton formation,adhesion,apoptosis,etc.process.Sphingosine 1-phosphate can not only activate the S1P-S1PR signaling pathway by binding to the corresponding receptors on the cell membrane,but also play a role in the cell.In recent years,studies have found that there is a certain relationship between its level changes and the occurrence and development of central nervous system diseases.This article reviews the latest knowledge of sphingosine-1-phosphate in the occurrence and treatment of nervous system diseases,and further clarifies its molecular mechanism in the treatment and development of central nervous system diseases.

和血柔肝方含药血清通过鞘氨醇激酶-1对肝星状细胞增殖与凋亡的作用

目的:和血柔肝方(HXRGF)含药血清调节鞘氨醇激酶-1(SphK1)对肝星状细胞(HSC)增殖与凋亡的作用。方法:采用Resistin处理HSC-T6细胞,建立纤维化HSC模型,采用LV-rSphK1-OE、LV-rSphk1-shRNA慢病毒方法构建SphK1过表达、低表达稳转细胞株,运用实时定量PCR、WB检测TGF-β、α-SMA、Col I、FN、Smad、SphK1mRNA及蛋白的表达、CCK8实验检测细胞活力、AnnexinV-APC/7-AAD流式细胞学检测细胞凋亡情况。结果:与对照组比较,MF-HSC-T6细胞中可见TGF-β、α-SMA、Col I、FN、SphK1mRNA及蛋白表达水平升高,Smad mRNA水平降低(P<0.01);HSC-T6 SphK1过表达细胞株中SphK1及相关纤维化标志物的表达水平升高(P<0.01);HSC-T6 SphK1低表达细胞株中TGF-β、α-SMA、Col I、FN mRNA等纤维化相关标志物降低,Smad mRNA水平升高(P<0.01)。与模型组比较,中药复方HXRGF含药血清干预后,可见MF-HSC T6 SphK1mRNA及蛋白表达水平降低,并同时伴有α-SMA、Col I、FN表达水平的下降(P<0.01),HSC细胞增殖率下降(110.85%);shRNA-SphK1转染组细胞增殖率下降,凋亡率(12.14%)升高(P<0.01);HSC-T6 SphK1低表达组细胞凋亡率(16.48%)升高(P<0.01)。结论:SphK1可作为肝纤维化潜在治疗靶点。HXRGF干预通过抑制SphK1表达,下调TGF-β、α-SMA等促纤维化因子的表达水平,抑制活化的HSC增殖,诱导HSC凋亡,缓解肝纤维化。

LncRNA PVT1对弥漫大B细胞淋巴瘤细胞活性的影响及其机制

目的 探究长链非编码RNA(LncRNA)浆细胞瘤变体异位基因1(PVT1)对弥漫大B细胞淋巴瘤(DLBCL)细胞生物学行为的影响,并分析其潜在机制。方法 收集41例DLBCL病人和15例淋巴结反应性增生(RLH)病人的组织标本,体外培养人正常B淋巴细胞GM12878和人DLBCL细胞(OCI-Ly3、U2932、TMD8),对TMD8细胞进行转染,将其分为control组(只转染Lipofectamine-2000)、si-NC组(转染si-NC)、inhibitor-NC组(转染inhibitor-NC)、si-PVT1组(转染si-PVT1)、miR-145-5p inhibitor组(转染miR-145-5p inhibitor)、si-PVT1+miR-145-5p inhibitor组(转染si-PVT1和miR-145-5p inhibitor)。应用qRT-PCR方法检测各组细胞PVT1 mRNA和miR-145-5p表达,Western Blot方法检测CDK6蛋白表达,CCK-8法检测TMD8细胞增殖,流式细胞术检测TMD8细胞周期变化,Transwell实验检测TMD8细胞迁移和侵袭能力,RNA pull down和双荧光素酶报告基因法验证PVT1、miR-145-5p与细胞周期蛋白依赖性激酶6(CDK6)的靶向关系。结果 DLBCL组织PVT1 mRNA、CDK6蛋白的表达水平高于RLH组织,miR-145-5p表达低于RLH组织(t=14.264~24.445,P<0.05)。与GM12878细胞比较,OCI-Ly3、U2932、TMD8细胞中PVT1 mRNA、CDK6蛋白表达均增加,miR-145-5p表达均减少(F=69.557~234.718,P<0.05)。6组细胞PVT1 mRNA、miR-145-5p、CDK6蛋白表达及增殖率、G0/G1期细胞比例、S期细胞比例、迁移和侵袭细胞数差异有统计学意义(F=25.589~319.150,P<0.05);与control组比较,si-PVT1组细胞PVT1 mRNA、CDK6蛋白、增殖率、S期细胞比例、迁移和侵袭数量降低,miR-145-5p表达、G0/G1期细胞比例升高(P<0.05),miR-145-5p inhibitor组呈相反变化(P<0.05);下调miR-145-5p表达可减弱敲低PVT1对TMD8细胞恶性生物学行为的抑制作用(P<0.05)。过表达PVT1 mRNA增高CDK6蛋白表达、细胞增殖率、S期细胞比例、迁移和侵袭数量,降低miR-145-5p表达、G0/G1期的细胞比例(F=38.025~327.887,P<0.05)。miR-145-5p是PVT1的靶基因,且miR-145-5p可靶向下调CDK6表达。结论 敲低PVT1可抑制DLBCL细胞恶性生物学行为,其作用机制可能与调控miR-145-5p/CDK6轴有关。