Unveiling the biological role of sphingosine-1-phosphate receptor modulators in inflammatory bowel diseases

Inflammatory bowel disease(IBD)is chronic inflammation of the gastrointestinal tract that has a high epidemiological prevalence worldwide.The increasing disease burden worldwide,lack of response to current biologic therapeutics,and treatment-related immunogenicity have led to major concerns regarding the clinical management of IBD patients and treatment efficacy.Understanding disease pathogenesis and disease-related molecular mechanisms is the most important goal in developing new and effective therapeutics.Sphingosine-1-phosphate(S1P)receptor(S1PR)modulators form a class of oral small molecule drugs currently in clinical development for IBD have shown promising effects on disease improvement.S1P is a sphingosine-derived phospholipid that acts by binding to its receptor S1PR and is involved in the regulation of several biological processes including cell survival,differentiation,migration,proliferation,immune response,and lymphocyte trafficking.T lymphocytes play an important role in regulating inflammatory responses.In inflamed IBD tissue,an imbalance between T helper(Th)and regulatory T lymphocytes and Th cytokine levels was found.The S1P/S1PR signaling axis and metabolism have been linked to inflammatory responses in IBD.S1P modulators targeting S1PRs and S1P metabolism have been developed and shown to regulate inflammatory responses by affecting lymphocyte trafficking,lymphocyte number,lymphocyte activity,cytokine production,and contributing to gut barrier function.

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.

STAT3 and sphingosine-1-phosphate in inflammation-associated colorectal cancer

Accumulated evidences have demonstrated that signal transducer and activator of transcription 3(STAT3)is a critical link between inflammation and cancer.Multiple studies have indicated that persistent activation of STAT3 in epithelial/tumor cells in inflammation-associated colorectal cancer(CRC)is associated with sphingosine-1-phosphate(S1P)receptor signaling.In inflammatory response whereby interleukin(IL)-6 production is abundant,STAT3-mediated pathways were found to promote the activation of sphingosine kinases(SphK1and SphK2)leading to the production of S1P.Reciprocally,S1P encourages the activation of STAT3 through a positive autocrine-loop signaling.The crosstalk between IL-6,STAT3 and sphingolipid regulated pathways may play an essential role in tumorigenesis and tumor progression in inflamed intestines.Therapeutics targeting both STAT3 and sphingolipid are therefore likely to contribute novel and more effective therapeutic strategies against inflammation-associated CRC.

Sphingosine-1-phosphate signaling in vasculogenesis and angiogenesis

Blood vessels either form de novo through the process of vasculogenesis or through angiogenesis that involves the sprouting and proliferation of endothelial cells in pre-existing blood vessels. A complex interactive network of signaling cascades downstream from at least three of the nine known G-protein-coupled sphingosine-1-phosphate (S1P) receptors act as a prime effector of neovascularization that occurs in embryonic development and in association with various pathologies. This review focuses on the current knowledge of the roles of S1P signaling in vasculogenesis and angiogenesis, with particular emphasis on vascular cell adhesion and motility responses.

Roles of sphingosine-1-phosphate signaling in angiogenesis

Sphingosine-1-phosphate (S1P) is a blood-borne lipid mediator with pleiotropic biological activities. S1P acts via the specific cell surface G-protein-coupled receptors, S1P1-5. S1P1 and S1P2 were originally identified from vascular endothelial cells (ECs) and smooth muscle cells, respectively. Emerging evidence shows that S1P plays crucial roles in the regulation of vascular functions, including vascular formation, barrier protection and vascular tone via S1P1, S1P2 and S1P3. In particular, S1P regulates vascular formation through multiple mechanisms; S1P exerts both positive and negative effects on angiogenesis and vascular maturation. The positive and negative effects of S1P are mediated by S1P1 and S1P2, respectively. These effects of S1P1 and S1P2 are probably mediated by the S1P receptors expressed in multiple cell types including ECs and bone-marrow-derived cells. The receptor-subtype-specific, distinct effects ofS1P favor the development of novel therapeutic tactics for antitumor angiogenesis in cancer and therapeutic angiogenesis in ischemic diseases.

Roles of sphingosine 1-phosphate on tumorigenesis

Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid with a variety of biological activities.It is generated from the conversion of ceramide to sphingosine by ceramidase and the subsequent conversion of sphingosine to S1P,which is catalyzed by sphingosine kinases.Through increasing its intracellular levels by sphingolipid metabolism and binding to its cell surface receptors,S1P regulates several physiological and pathological processes,including cell proliferation,migration,angiogenesis and autophagy.These processes are responsible for tumor growth,metastasis and invasion and promote tumor survival.Since ceramide and S1P have distinct functions in regulating in cell fate decision,the balance between the ceramide/sphingosine/S1P rheostat becomes a potent therapeutic target for cancer cells.Herein,we summarize our current understanding of S1P signaling on tumorigenesis and its potential as a target for cancer therapy.

Role of sphingosine 1-phosphate in anti-atherogenic actions of high-density lipoprotein

The reverse cholesterol transport mediated by highdensity lipoprotein(HDL)is an important mechanism for maintaining body cholesterol,and hence,the crucial anti-atherogenic action of the lipoprotein.Recent studies,however,have shown that HDL exerts a variety of anti-inflammatory and anti-atherogenic actions independently of cholesterol metabolism.The present review provides an overview of the roles of sphingosine 1-phosphate(S1P)/S1P receptor and apolipoprotein A-I/ scavenger receptor class B typeⅠsystems in the antiatherogenic HDL actions.In addition,the physiological significance of the existence of S1P in the HDL particles is discussed.

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.

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.

Incorporation of Sphingosine 1-Phosphate Loaded Mesoporous Silica Nanoparticles into Poly ( L-lactic acid ) Nanofibrous Scaffolds for Bone Tissue Engineering

Controlled release of the functional factors is the key to improve clinical therapeutic efficacy during the tissue repair and regeneration.The three-dimensional(3D)scaffold can provide not only physical properties such as high strength and porosity but also an optimal environment to enhance tissue regeneration.Sphingosine1-phosphate(S1P),an angiogenic factor,was loaded into mesoporous silica nanoparticles(MSNs)and then incorporated into poly(L-lactic acid)(PLLA)nanofibrous scaffold,which was fabricated by thermally induced phase separation(TIPS)method.The prepared scaffolds were examined by attenuated total reflection Fourier transform infrared spectroscopy(ATR-FTIR),scanning electron microscopy(SEM),and transmission electron microscopy(TEM)and compressive mechanical test.The ATR-FTIR result demonstrated the existence of MSNs in the PLLA nanofibrous scaffold.The SEM images showed that PLLA scaffold had regular pore channel,interconnected pores and nanofibrous structure.The addition of MSNs at appropriate content had no visible effect on the structure of scaffold.The compressive modulus of scaffold containing MSNs was higher than that of the scaffold without MSNs.Furthermore,fluorescein isothiocyanate(FITC)was used as model molecule to investigate the release behavior of S1P from MSNsincorporated PLLA(MSNs/PLLA)nanofibrous scaffold.The result showed that the composite scaffold largely reduced the initial burst release and exhibited prolonged release of FITC than MSNs.Thus,these results indicated that S1P-loaded composite nanofibrous scaffold has potential applications for bone tissue engineering.

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.

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.

Sphingosine 1-phosphate in inflammation

Sphingolipids are formed via the metabolism of sphingomyelin,aconstituent of the plasma membrane.or by denovosynthesis.Enzymatic pathways result in the formation of sevenal different lipid meiators,which are knowm to bave important roles in many elllar proceses.imcluding polfeatioe,apoptosis and migation Several studies nDowr suggest that these shingolipid mediators,inchding cenamide,ceramside i-pbosphate and sphingosine 1-pbosphate(SIP).are likely to have a integral role in infamation.This can involve,for example activation of po-inammatory transcription factors in different cell types and indiuction of cyloxygenase-2.leading t如o productio of pro-inamatory prostaglandins.The mode of action of each sphingolipid is different.Increased ceramide production leads to the formation of ceramide-rich areas of the membnane.which may assemble sigalling compleses,whereas SIP acts via b-affnity G-protein-coupled SIP receptors on the plasma membrane.Recent studies bave demonstated that in vitro efects of sphingolipids o infammation can translate into in vivo models.This review will higblight the areas of research where spbingolipids ae involved in infamomation and the mecharisms of acion of each mediator.In adirion,the therpeutic poternial of dinugs that alter sphingolipid actions mill be exmined with reference to disease states,such as asthma and infammatary bowel disease,which invove importanot ifmaxmsutory components.A signifcant body of research now indicates that sphingolipids ure intimately inolved in the infammatory process and recent studies have demonstated that these lipids.together with associated enzymes and receptors,can provide effective drug targets for the treatment of pathological inflammation.

Role of Sphingosine 1-Phosphate (S1P) Receptor 1 in Experimental Autoimmune Encephalomyelitis —I

Infiltration of myelin-specific helper T (Th) cells into the central nervous system (CNS) plays a key role in pathogenesis of experimental autoimmune encephalomyelitis (EAE). In this study, we investigated the involvement of sphingosine 1-phosphate (S1P)-S1P receptor 1 (S1P1) axis in lymphocytes for EAE development when C57BL/6 mice were immunized with myelin oliogodendrocyte glycoprotein (MOG). The expression of S1P1 mRNA and S1P responsiveness of lymphocytes in draining lymph nodes (DLN) were down-regulated markedly after MOG immunization until onset of EAE. Accompanying with reacquisition of down-regulated S1P1 transcript and S1P responsiveness in DLN lymphocytes, MOG-immunized mice developed EAE symptoms with significant infiltration of Th1 and Th17 cells into the CNS and a marked elevation of IFN-γ, T-bet, IL-17, and RORγt mRNA expressions. Prophylactic administration of an S1P1 functional antagonist, fingolimod hydrochloride (FTY720, 0.3 mg/kg, orally) significantly inhibited EAE development and almost completely prevented infiltration of Th1 and Th17 cells into the CNS with a marked reduction of IFN-γ, T-bet, IL-17, and RORγt mRNA expressions. Similar results were obtained by treatment with an S1P1-selective agonist, SEW2871 or an S1P lyase inhibitor, 2-acetyl-4-tetrahydroxybutylimidazole. Moreover, FTY720-phosphate and SEW2871 inhibited in vitro migration of Th1 and Th17 cells toward S1P but did not affect cytokine production or generation of Th1 or Th17 cells. These results suggest that reacquisition of S1P1 expression in DLN lymphocytes plays a major role in trafficking of myelin antigen-specific Th1/Th17 cells from DLN to the CNS in EAE and that prophylactic effect of FTY720 on EAE is predominantly caused by functional antagonism via lymphocytic S1P1.

Role of Sphingosine 1-Phosphate (S1P) Receptor 1 in Experimental Autoimmune Encephalomyelitis —II

Therapeutic administration of fingolimod hydrochloride (FTY720), the functional antagonist at sphingosine 1-phosphate (S1P) receptor 1 (S1P1) shows a marked improving effect on experimental autoimmune encephalomyelitis (EAE) induced by myelin oligodendrocyte glycoprotein (MOG) in C57BL/6 mice. However, this treatment showed an only partial inhibition of Th1/Th17 cell infiltration into the central nervous system (CNS), suggesting that down-regulation of lymphocytic S1P1 is insufficient to explain the therapeutic effect of FTY720 on EAE. On the other hand, the therapeutic administration of FTY720 reduced the mRNA expressions of IL-6, CCL2, and glial fibrillary acidic protein, an activation marker of astrocytes, in the CNS of EAE mice. In human astrocytic glyoma, U373MG cells, mRNA expression of S1P1 was higher as compared with those of the other S1P receptor subtypes and phosphorylation of Akt was induced by S1P, FTY720-phosphate (FTY720-P), or an S1P1-selective agonist, SEW2871. FTY720-P appeared to induce down-regulation of S1P1 in U373MG cells, implying a functional antagonism at S1P1 on astrocytes. S1P but not FTY720-P induced production of IL-6, IL-8, and CCL2 significantly and treatment with FTY720-P or SEW2871 inhibited production of these pro-inflammatory cytokines from U373MG cells stimulated with S1P. These results suggest that S1P-S1P1 axis induces production of pro-inflammatory cytokines by astrocytes. Consequently, it is highly probable that the therapeutic effects of FTY720 on EAE are caused by inhibiting not only egress of myelin-specific Th cells from the draining lymph nodes but also activation of astrocytes in the CNS.

Aryl hydrocarbon receptor signaling promotes ORMDL3- dependent generation of sphingosine-1-phosphate by inhibiting sphingosine-1-phosphate lyase

Aryl hydrocarbon receptor(AhR),a cellular chemical sensor,controls cellular homeostasis,and sphingosine-1-phosphate(S1P),a bioactive intermediate of sphingolipid metabolism,is believed to have a role in immunity and inflammation,but their potential crosstalk is currently unknown.We aimed to determine whether there is a functional linkage between AhR signaling and sphingolipid metabolism.We showed that AhR ligands,including an environmental polycyclic aromatic hydrocarbon(PAH),induced S1P generation,and inhibited S1P lyase(S1PL)activity in resting cells,antigen/IgE-activated mast cells,and mouse lungs exposed to the AhR ligand alone or in combination with antigen challenge.The reduction of S1PL activity was due to AhR-mediated oxidation of S1PL at residue 317,which was reversible by the addition of an antioxidant or in cells with knockdown of the ORMDL3 gene encoding an ER transmembrane protein,whereas C317A S1PL mutant-transfected cells were resistant to the AhR-mediated effect.Furthermore,analysis of AhR ligand-treated cells showed a time-dependent increase of the ORMDL3–S1PL complex,which was confirmed by FRET analysis.This change increased the S1P levels,which in turn,induced mast cell degranulation via S1PR2 signaling.In addition,elevated levels of plasma S1P were found in children with asthma compared to non-asthmatic subjects.These results suggest a new regulatory pathway whereby the AhR–ligand axis induces ORMDL3-dependent S1P generation by inhibiting S1PL,which may contribute to the expression of allergic diseases.

Sphingosine-1-phosphate signaling and the gut-liver axis in liver diseases

The liver is the central organ involved in lipid metabolism and the gastrointestinal(GI)tract is responsible for nutrient absorption and partitioning.Obesity,dyslipidemia and metabolic disorders are of increasing public health concern worldwide,and novel therapeutics that target both the liver and the GI tract(gut-liver axis)are much needed.In addition to aiding fat digestion,bile acids act as important signaling molecules that regulate lipid,glucose and energy metabolism via activating nuclear receptor,G protein-coupled receptors(GPCRs),Takeda G protein receptor 5(TGR5)and sphingosine-1-phosphate receptor 2(S1PR2).Sphingosine-1-phosphate(S1P)is synthesized by two sphingosine kinase isoforms and is a potent signaling molecule that plays a critical role in various diseases such as fatty liver,in-flammatory bowel disease(IBD)and colorectal cancer.In this review,we will focus on recent findings related to the role of S1P-mediated signaling pathways in the gut-liver axis.

Down-regulation of miR-155 inhibits inflammatory response in human pulmonary microvascular endothelial cells infected with influenza A virus by targeting sphingosine-1-phosphate receptor 1

Background:Endothelial cells play a key role in the cytokine storm caused by influenza A virus. MicroRNA-155 (miR-155) is an important regulator in inflammation. Its role in the inflammatory response to influenza A infection, however, has yet to be elucidated. In this study, we explored the role as well as the underlying mechanism of miR-155 in the cytokine production in influenza A-infected endothelial cells.Methods:Human pulmonary microvascular endothelial cells (HPMECs) were infected with the influenza A virus strain H1N1. The efficiency of H1N1 infection was confirmed by immunofluorescence. The expression levels of proinflammatory cytokines and miR-155 were determined using real-time polymerase chain reaction. A dual-luciferase reporter assay characterized the interaction between miR-155 and sphingosine-1-phosphate receptor 1 (S1PR1). Changes in the target protein levels were determined using Western blot analysis.Results:MiR-155 was elevated in response to the H1N1 infection in HPMECs (24 h post-infection vs. 0 h post-infection, 3.875 ± 0.062 vs. 1.043 ± 0.013, P = 0.001). Over-expression of miR-155 enhanced inflammatory cytokine production (miR-155 mimic vs. negative control, all P < 0.05 in regard of cytokine levels) and activation of nuclear factor kappa B in infected HPMECs (miR-155 mimic vs. negative control, P = 0.004), and down-regulation of miR-155 had the opposite effect. In addition, S1PR1 was a direct target of miR-155 in the HPMECs. Inhibition of miR-155 enhanced the expression of the S1PR1 protein. Down-regulation of S1PR1 decreased the inhibitory effect of the miR-155 blockade on H1N1-induced cytokine production and nuclear factor kappa B activation in HPMECs. Conclusion:MiR-155 maybe modulate influenza A-induced inflammatory response by targeting S1PR1.

青藤碱可有效抑制白细胞介素1β介导的髓核细胞凋亡

背景:椎间盘退变是导致脊柱退行性疾病的基础,然而目前尚无有效的治疗药物。目的:探讨青藤碱是否可以抑制白细胞介素1β诱导的髓核细胞凋亡及其分子机制。方法:采用胰酶联合Ⅱ型胶原酶消化法体外培养大鼠髓核细胞,并绘制细胞生长曲线,采用CCK-8法筛选合适的青藤碱药物浓度。将髓核细胞分为对照组、青藤碱组、白细胞介素1β组、青藤碱+白细胞介素1β组、锌原卟啉(血红素氧合酶1抑制剂)组、锌原卟啉+青藤碱组、锌原卟啉+白细胞介素1β组、青藤碱+锌原卟啉+白细胞介素1β组。分别检测各组髓核细胞增殖活性、活性氧含量、凋亡率及血红素氧合酶1的表达情况。结果与结论:①体外培养的大鼠髓核细胞呈现多角形、三角形、短楔形等形态,其呈现“S”型曲线生长,接种第1-3天生长缓慢,第4-6天生长迅速,第七八天生长速度缓慢,进入“平台期”,细胞数量不再增加;②当青藤碱的浓度≤80μmol/L时,髓核细胞的增殖活性不会受到显著影响(P>0.05);③白细胞介素1β可以显著降低髓核细胞的增殖活性,增加活性氧含量,导致细胞凋亡(P<0.01);④当采用青藤碱干预后,不仅可以促进血红素氧合酶1的表达(P<0.05),而且可以抑制白细胞介素1β诱导的髓核细胞增殖活性降低、活性氧含量和凋亡率增加(P<0.05),其作用可被锌原卟啉逆转(P<0.01)。