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 sur...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.展开更多
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 ST...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.展开更多
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 n...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.展开更多
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 p...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.展开更多
Gamma-aminobutyric acid(GABA)ergic neurons,the most abundant inhibitory neurons in the human brain,have been found to be reduced in many neurological disorders,including Alzheimer's disease and Alzheimer's dis...Gamma-aminobutyric acid(GABA)ergic neurons,the most abundant inhibitory neurons in the human brain,have been found to be reduced in many neurological disorders,including Alzheimer's disease and Alzheimer's disease-related dementia.Our previous study identified the upregulation of microRNA-502-3p(miR-502-3p)and downregulation of GABA type A receptor subunitα-1 in Alzheimer's disease synapses.This study investigated a new molecular relationship between miR-502-3p and GABAergic synapse function.In vitro studies were perfo rmed using the mouse hippocampal neuronal cell line HT22 and miR-502-3p agomiRs and antagomiRs.In silico analysis identified multiple binding sites of miR-502-3p at GABA type A receptor subunitα-1 mRNA.Luciferase assay confirmed that miR-502-3p targets the GABA type A receptor subunitα-1 gene and suppresses the luciferase activity.Furthermore,quantitative reve rse transcription-polymerase chain reaction,miRNA in situ hybridization,immunoblotting,and immunostaining analysis confirmed that overexpression of miR-502-3p reduced the GABA type A receptor subunitα-1 level,while suppression of miR-502-3p increased the level of GABA type A receptor subunitα-1 protein.Notably,as a result of the overexpression of miR-502-3p,cell viability was found to be reduced,and the population of necrotic cells was found to be increased.The whole cell patch-clamp analysis of human-GABA receptor A-α1/β3/γ2L human embryonic kidney(HEK)recombinant cell line also showed that overexpression of miR-502-3p reduced the GABA current and overall GABA function,suggesting a negative correlation between miR-502-3p levels and GABAergic synapse function.Additionally,the levels of proteins associated with Alzheimer s disease were high with miR-502-3p overexpression and reduced with miR-502-3p suppression.The present study provides insight into the molecular mechanism of regulation of GABAergic synapses by miR-502-3p.We propose that micro-RNA,in particular miR-502-3p,could be a potential therapeutic to rget to modulate GABAergic synapse function in neurological disorders,including Alzheimer's disease and Alzheimer's diseaserelated dementia.展开更多
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 i...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.展开更多
AIM To investigate the effect of(-)-epigallocatechin-3-gallate(EGCG) on polyinosinic-polycytidylic acid(poly I:C)-triggered intracellular innate immunity against hepatitis C virus(HCV) in hepatocytes. METHODS A cell c...AIM To investigate the effect of(-)-epigallocatechin-3-gallate(EGCG) on polyinosinic-polycytidylic acid(poly I:C)-triggered intracellular innate immunity against hepatitis C virus(HCV) in hepatocytes. METHODS A cell culture model of HCV infection was generated by infecting a hepatoma cell line, Huh7, with HCV JFH-1 strain(JFH-1-Huh7). Poly I:C with a high molecular weight and EGCG were used to stimulate the JFH-1-Huh7 cells. Real-time reverse transcription-polymerase chain reaction was used to detect the expression levels of intracellular m RNAs and of intracellular and extracellular HCV RNA. Enzyme-linked immunosorbent assay was used to evaluate the interferon(IFN)-λ1 protein level in the cell culture supernatant. Immunostaining was used to examine HCV core protein expression in Huh7 cells.RESULTS Our recent study showed that HCV replication could impair poly I:C-triggered intracellular innate immune responses in hepatocytes. In the current study, we showed that EGCG treatment significantly increased the poly I:C-induced expression of Toll-like receptor 3(TLR3), retinoic acid-inducible gene I, and IFN-λ1 in JFH-1-Huh7 cells. In addition, supplementation with EGCG increased the poly I:C-mediated antiviral activity in JFH-1-Huh7 cells at the intracellular and extracellular HCV RNA and protein levels. Further investigation of the mechanisms showed that EGCG treatment significantly enhanced the poly I:C-induced expression of IFN-regulatory factor 9 and several antiviral IFNstimulated genes, including ISG15, ISG56, myxovirus resistance A, and 2'-5'-oligoadenylate synthetase 1, which encode the key antiviral elements in the IFN signaling pathway. CONCLUSION Our observations provide experimental evidence that EGCG has the ability to enhance poly I:C-induced intracellular antiviral innate immunity against HCV replication in hepatocytes.展开更多
Previous studies have suggested that miR-324-3p is related to the pathophysiology of cerebral ischemia,but the mechanism underlying this relationship is unclea r.In this study,we found that miR-324-3p expression was d...Previous studies have suggested that miR-324-3p is related to the pathophysiology of cerebral ischemia,but the mechanism underlying this relationship is unclea r.In this study,we found that miR-324-3p expression was decreased in patients with acute ischemic stroke and in in vitro and in vivo models of ischemic stro ke.miR-324-3p agomir potentiated ischemic brain damage in rats subjected to middle cerebral artery occlusion,as indicated by increased infarct volumes and cell apoptosis rates and greater neurological deficits.In a PC12 cell oxygen-glucose deprivation/reoxygenation model,a miR-324-3 p mimic decreased cell viability and expression of the anti-apoptotic protein BCL2 and increased expression of the pro-apoptotic protein BAX and rates of cell apoptosis,whereas treatment with a miR-324-3p inhibitor had the opposite effects.Silencing miR-324-3p increased adenosine A1 receptor(A1R)expression thro ugh regulation of GATA binding protein 2(GATA2).These findings suggest that silencing miR-324-3p reduces ischemic brain damage via the GATA2/A1R axis.展开更多
This study investigated the modulatory effect of synthetic cannabinoids WIN55,212-2 on 5-HT3 receptor-activated currents (I5-HT3) in cultured rat trigeminal ganglion (TG) neurons using whole-cell patch clamp technique...This study investigated the modulatory effect of synthetic cannabinoids WIN55,212-2 on 5-HT3 receptor-activated currents (I5-HT3) in cultured rat trigeminal ganglion (TG) neurons using whole-cell patch clamp technique. The results showed that: (1) The majority of examined neurons (78.70%) were sensitive to 5-HT (3–300 μmol/L). 5-HT induced inward currents in a concentration-dependent manner and the currents were blocked by ICS 205-930 (1 μmol/L), a selective antagonist of the 5-HT3 receptor; (2) Pre-application of WIN55,212-2 (0.01–1 μmol/L) significantly inhibited I5-HT3 reversibly in concentration-dependent and voltage-independent manners. The concentra-tion-response curve of 5-HT3 receptor was shifted downward by WIN55,212-2 without any change of the threshold value. The EC50 values of two curves were very close (17.5±4.5) mmol/L vs. (15.2±4.5) mmol/L and WIN55,212-2 decreased the maximal amplitude of I5-HT3 by (48.65±4.15)%; (3) Neither AM281, a selective CB1 receptor antagonist, nor AM630, a selective CB2 receptor antagonist reversed the inhibition of I5-HT3 by WIN55,212-2; (4) When WIN55,212-2 was given from 15 to 120 s before 5-HT application, inhibitory effect was gradually increased and the maximal inhibition took place at 90 s, and the inhibition remained at the same level after 90 s. We are led to concluded that-WIN55,212-2 inhibited I5-HT3 significantly and neither CB1 receptor antagonist nor CB2 receptor antagonist could reverse the inhibition of I5-HT3 by WIN55,212-2. Moreover, WIN55,212-2 is not an open channel blocker (OCB) of 5-HT3 receptor. WIN55,212-2 significantly inhibited 5-HT-activated currents in a non-competitive manner. The inhibition of I5-HT3 by WIN55,212-2 is probably new one of peripheral analgesic mechanisms of WIN55,212-2, but the mechanism by which WIN55,212-2 inhibits I5-HT3 warrants further investigation.展开更多
Mangoes (Mangifera indica L.) are one of the most important tropical foods. The seed is one of the main by-products of mango processing. Therefore, it is important to find an economically viable use for this waste (e....Mangoes (Mangifera indica L.) are one of the most important tropical foods. The seed is one of the main by-products of mango processing. Therefore, it is important to find an economically viable use for this waste (e.g., as a food additive or supplement with high nutraceutical value). We investigated the anti-obesity effects of mango seed kernel extract with hot water (MSKE-W) in 3T3-L1 adipocytes and in a high fat diet (HFD)-induced obesity rat model. MSKE-W caused a significant decrease in the activity of glycerol 2-phosphate dehydrogenase in 3T3-L1 adipocytes without eliciting cell cytotoxicity and inhibited cellular lipid accumulation through down-regulation of transcription factors such as PPARγ and C/EBPα. In the animal model, rats fed an HFD containing 1% MSKE-W gained less weight than rats fed an HFD alone. The visceral fat mass in rats fed an HFD containing 1% MSKE-W tended to be lower than that in rats fed an HFD alone. Furthermore, histological examination of rat livers from an HFD showed steatohepatitis. However, rats on an HFD containning 1% MSKE-W showed no histopathological changes in liver tissue. Our results indicate that MSKE-W influences anti-obesity effects, both in vitro and in vivo, and suggest that MSKE-W provides a novel preventive potential against obesity.展开更多
We cloned the complete coding sequences of porcine Gpr3, Gpr6, and Gpr12 genes. Further, on the basis of their high levels of sequence similarity, these genes are identified as a subfamily of G protein-coupled recepto...We cloned the complete coding sequences of porcine Gpr3, Gpr6, and Gpr12 genes. Further, on the basis of their high levels of sequence similarity, these genes are identified as a subfamily of G protein-coupled receptors. These putative protein sequences also showed high sequence identity with other mammalian orthologs, including several highly conserved motifs. A wide expression of the Gpr3 gene in pigs was observed through tissue distribution analysis by reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time PCR, specially in the brain, pituitary, fat, liver and oocyte, where its strong expression was observed. The Gpr3 gene was found to be located on chromosome 6 and a single exon coded for the entire open reading frame. Expression of porcine Gpr3 in HEK293 cells resulted in constitutive activation of adenylate cyclase (AC) similar in amplitude to that produced by fully stimulated Gs coupled receptors. Moreover, sphingosine 1-phosphate (S1P) could increase AC activation via the constitutively active Gpr3 receptor. When a Gpr3-green fluorescent protein (GFP) construct was expressed in HEK293 cells, GFP-labeled Gpr3 protein was shown to be localized in the plasmalemma and subcellular membranes. After S1P treatment, agonist-mediated internalization could be visualized by confocal microscopy. In short, our findings suggest the porcine Gpr3, Gpr6, and Gpr12 genes as a subfamily of G protein-coupled receptors, and porcine Gpr3 was a constitutively active G protein-coupled receptor. Constitutive activation of AG and agonist-mediated internalization of Gpr3 receptor could be modulated by the S1 P, suggesting that S1P might act as an activator for porcine Gpr3 receptor.展开更多
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 i...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.展开更多
The role of B7-1 in podocyte injury has received increasing attention.The aim of this study was to investigate whether losartan protects podocytes of patients with diabetic kidney disease(DKD)by regulating B7-1 and th...The role of B7-1 in podocyte injury has received increasing attention.The aim of this study was to investigate whether losartan protects podocytes of patients with diabetic kidney disease(DKD)by regulating B7-1 and the underlying mechanisms.Rats with streptozotocin-induced DKD were treated with losartan for 8 weeks.Biochemical changes in blood and urine were analyzed.Kidneys were isolated for electron microscopy,immunofluorescence,real-time quantitative PCR(RT-PCR),and Western blot analysis.Immortalized mouse podocyte cells were cultured in normal or high glucose medium in the presence or absence of losartan for 48 h,and then the cells were collected for immunofluorescence,PCR,Western blotting and monolayer permeability detection.The phosphatidylinositol 3-kinase(PI3K)110a subunit and angiotensin II type 1 receptor(AT1R)plasmids were transfected into podocytes,respectively,and then Western blotting was performed to assess the expression of B7-1 protein.The results showed that losartan ameliorated podocyte structure and function in the rat model of DKD,and reduced the expression of B7-1 protein.Overexpression of PI3K 110a subunit in podocytes attenuated the inhibitory effect of losartan on B7-1 expression in high glucose-stimulated podocytes.The expression of B7-1 was significantly increased by overexpression of ATI R and significantly reduced by blocking PI3K 110a subunit.We conclude that losartan protects podocytes against high glucose-induced injury by inhibiting AT1R-mediated B7-1 expression.This effect is dependent on the AT1R-PI3K 110a subunit pathway.展开更多
Most hematopoietic stem progenitor cells (HSPCs) reside in bone marrow (BM), but a small amount of HSPCs have been found to circulate between BM and tissues through blood and lymph. Several lines of evidence suggest t...Most hematopoietic stem progenitor cells (HSPCs) reside in bone marrow (BM), but a small amount of HSPCs have been found to circulate between BM and tissues through blood and lymph. Several lines of evidence suggest that sphingosine-1-phosphate (S1P) gradient triggers HSPC egression to blood circulation after mobilization from BM stem cell niches. Stem cells also visit certain tissues. After a temporary 36 h short stay in local tissues, HSPCs go to lymph in response to S1P gradient between lymph and tissue and eventually enter the blood circulation. S1P also has a role in the guidance of the primitive HSPCs homing to BM in vivo, as S1P analogue FTY720 treatment can improve HSPC BM homing and engraftment. In stress conditions, various stem cells or progenitor cells can be attracted to local injured tissues and participate in local tissue cell differentiation and tissue rebuilding through modulation the expression level of S1P1, S1P2 or S1P3 receptors. Hence, S1P is important for stem cells circulation in blood system to accomplish its role in body surveillance and injury recovery.展开更多
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 publ...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.展开更多
BACKGROUND Remarkable progress over the last decade has equipped clinicians with many options in the treatment of inflammatory bowel disease.Clinicians now have the unique opportunity to provide individualized treatme...BACKGROUND Remarkable progress over the last decade has equipped clinicians with many options in the treatment of inflammatory bowel disease.Clinicians now have the unique opportunity to provide individualized treatment that can achieve and sustain remission in many patients.However,issues of primary non-response(PNR)and secondary loss of response(SLOR)to non-tumour necrosis factor inhibitor(TNFi)therapies remains a common problem.Specific issues include the choice of optimization of therapy,identifying when dose optimization will recapture response,establishing optimal dose for escalation and when to switch therapy.AIM To explores the issues of PNR and SLOR to non-TNFi therapies.METHODS This review explores the current evidence and literature to elucidate management options in cases of PNR/SLOR.It will also explore potential predictors for response following SLOR/PNR to therapies including the role of therapeutic drug monitoring(TDM).RESULTS In the setting of PNR and loss of response to alpha-beta7-integrin inhibitors and interleukin(IL)-12 and IL-23 inhibitors dose optimization is a reasonable option to capture response.For Janus kinase inhibitors dose optimization can be utilized to recapture response with loss of response.CONCLUSION The role of TDM in the setting of advanced non-TNFi therapies to identify patients who require dose optimization and as a predictor for clinical remission is not yet established and this remains an area that should be addressed in the future.展开更多
5-HT_(1A)receptor is associated with a variety of pathophysiology of neuropsychiatric disorders.Accordingly,we have synthesized a new 5-HT_(1A) receptor ligand(HYNIC-MPP4)and labeled it with^(99m)Tc using N-(2-hydroxy...5-HT_(1A)receptor is associated with a variety of pathophysiology of neuropsychiatric disorders.Accordingly,we have synthesized a new 5-HT_(1A) receptor ligand(HYNIC-MPP4)and labeled it with^(99m)Tc using N-(2-hydroxyethyl)ethylenediaminetriacetic acid(HEDTA)as coligand.^(99m)Tc-HEDTA/HYNIC-MPP4 was prepared under pH 6 at room temperature.Biodistribution of^(99m)Tc-HEDTA/HYNIC-MPP4 in normal mice showed that this complex had moderate brain uptake(0.60%ID·g^(-1)at 2 min p.i.)and good retention.The hippocampus had the highest radioactivity uptake at 2 min p.i.(1.84%ID·g^(-1)).The ratio of Hipp/CB was 3.1 at 2 min p.i.and increased to 4.4 at 60 min p.i.After blocking with 8-hydroxy-2-(dipropylamino)tetralin,the uptake of hippocampus was decreased significantly from 1.84%ID·g^(-1) to 0.53%ID·g^(-1) at 2 min p.i.,while the cerebellum had no significant decrease.This^(99m)Tc complex could be a potent agent for 5-HT_(1A) receptor imaging.展开更多
Recent research on the underlying mechanisms of cerebral ischemia indicates that the neurovascular unit can be used as a novel subject for general surveys of neuronal damage and protein mechanisms.Fingolimod(FTY-720)i...Recent research on the underlying mechanisms of cerebral ischemia indicates that the neurovascular unit can be used as a novel subject for general surveys of neuronal damage and protein mechanisms.Fingolimod(FTY-720)is a newly developed immunosuppressant isolated from Cordyceps sinensis that exhibits a wide range of biological activities,and has recently attracted much attention for the treatment of ischemic cerebrovascular diseases.In the current research,the role of FTY-720 and its possible mechanisms were assessed from an neurovascular unit perspective using a rat cerebral ischemia model.Our results revealed that FTY-720 markedly decreased infarct volume,promoted neurological function recovery,and weakened the blood-brain barrier permeability of ischemic rats.The protective roles of FTY-720 in ischemic stroke are ascribed to a combination of sphingosin-1-phosphate receptor-1 and reduced expression of sphingosin-1-phosphate receptor-1 in microvessels and reduction of interleukin-17A protein levels.These findings indicate that FTY-720 has promise as a new therapy for neurovascular protection and functional recovery after ischemic stroke.展开更多
Idiopathic pulmonary fibrosis(IPF)is a progressive lung disease with unclear etiology and limited treatment options.The median survival time for IPF patients is approximately 2–3 years and there is no effective inter...Idiopathic pulmonary fibrosis(IPF)is a progressive lung disease with unclear etiology and limited treatment options.The median survival time for IPF patients is approximately 2–3 years and there is no effective intervention to treat IPF other than lung transplantation.As important components of lung tissue,endothelial cells(ECs)are associated with pulmonary diseases.However,the role of endothelial dysfunction in pulmonary fibrosis(PF)is incompletely understood.Sphingosine-1-phosphate receptor 1(S1PR1)is a G protein-coupled receptor highly expressed in lung ECs.Its expression is markedly reduced in patients with IPF.Herein,we generated an endothelial-conditional S1pr1 knockout mouse model which exhibited inflammation and fibrosis with or without bleomycin(BLM)challenge.Selective activation of S1PR1 with an S1PR1 agonist,IMMH002,exerted a potent therapeutic effect in mice with bleomycin-induced fibrosis by protecting the integrity of the endothelial barrier.These results suggest that S1PR1 might be a promising drug target for IPF therapy.展开更多
文摘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.
文摘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.
基金Supported by Grants from the United States Public Health Service/National Institutes of Health, No. HL080404, HL094883 (Argraves KM) and HL061873, HL095067 (Argraves WS)NIH Training Grant to Improve Cardiovascular Therapies HL007260 (Wilkerson BA)American Heart Association 10PRE3910006 (Wilkerson BA)
文摘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.
基金supported by the National Natural Science Foundation of China(No.81873505).
文摘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.
基金supported by the National Institute on Aging (NIA)National Institutes of Health (NIH)+3 种基金Nos.K99AG065645,R00AG065645R00AG065645-04S1 (to SK)NIH research grants,NINDS,No.R01 NS115834NINDS/NIA,No.R01 NS115834-02S1 (to LG)。
文摘Gamma-aminobutyric acid(GABA)ergic neurons,the most abundant inhibitory neurons in the human brain,have been found to be reduced in many neurological disorders,including Alzheimer's disease and Alzheimer's disease-related dementia.Our previous study identified the upregulation of microRNA-502-3p(miR-502-3p)and downregulation of GABA type A receptor subunitα-1 in Alzheimer's disease synapses.This study investigated a new molecular relationship between miR-502-3p and GABAergic synapse function.In vitro studies were perfo rmed using the mouse hippocampal neuronal cell line HT22 and miR-502-3p agomiRs and antagomiRs.In silico analysis identified multiple binding sites of miR-502-3p at GABA type A receptor subunitα-1 mRNA.Luciferase assay confirmed that miR-502-3p targets the GABA type A receptor subunitα-1 gene and suppresses the luciferase activity.Furthermore,quantitative reve rse transcription-polymerase chain reaction,miRNA in situ hybridization,immunoblotting,and immunostaining analysis confirmed that overexpression of miR-502-3p reduced the GABA type A receptor subunitα-1 level,while suppression of miR-502-3p increased the level of GABA type A receptor subunitα-1 protein.Notably,as a result of the overexpression of miR-502-3p,cell viability was found to be reduced,and the population of necrotic cells was found to be increased.The whole cell patch-clamp analysis of human-GABA receptor A-α1/β3/γ2L human embryonic kidney(HEK)recombinant cell line also showed that overexpression of miR-502-3p reduced the GABA current and overall GABA function,suggesting a negative correlation between miR-502-3p levels and GABAergic synapse function.Additionally,the levels of proteins associated with Alzheimer s disease were high with miR-502-3p overexpression and reduced with miR-502-3p suppression.The present study provides insight into the molecular mechanism of regulation of GABAergic synapses by miR-502-3p.We propose that micro-RNA,in particular miR-502-3p,could be a potential therapeutic to rget to modulate GABAergic synapse function in neurological disorders,including Alzheimer's disease and Alzheimer's diseaserelated dementia.
文摘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.
基金Supported by the National Natural Science Foundation of China,No.81500449the Natural Science Foundation of Shanghai,No.14ZR1434200+2 种基金Shanghai Municipal Commission of Health and Family Planning,No.20144Y0175the Scientific Research Foundation for the Returned Overseas Chinese Scholarsthe State Education Ministry of China,No.20150909-6
文摘AIM To investigate the effect of(-)-epigallocatechin-3-gallate(EGCG) on polyinosinic-polycytidylic acid(poly I:C)-triggered intracellular innate immunity against hepatitis C virus(HCV) in hepatocytes. METHODS A cell culture model of HCV infection was generated by infecting a hepatoma cell line, Huh7, with HCV JFH-1 strain(JFH-1-Huh7). Poly I:C with a high molecular weight and EGCG were used to stimulate the JFH-1-Huh7 cells. Real-time reverse transcription-polymerase chain reaction was used to detect the expression levels of intracellular m RNAs and of intracellular and extracellular HCV RNA. Enzyme-linked immunosorbent assay was used to evaluate the interferon(IFN)-λ1 protein level in the cell culture supernatant. Immunostaining was used to examine HCV core protein expression in Huh7 cells.RESULTS Our recent study showed that HCV replication could impair poly I:C-triggered intracellular innate immune responses in hepatocytes. In the current study, we showed that EGCG treatment significantly increased the poly I:C-induced expression of Toll-like receptor 3(TLR3), retinoic acid-inducible gene I, and IFN-λ1 in JFH-1-Huh7 cells. In addition, supplementation with EGCG increased the poly I:C-mediated antiviral activity in JFH-1-Huh7 cells at the intracellular and extracellular HCV RNA and protein levels. Further investigation of the mechanisms showed that EGCG treatment significantly enhanced the poly I:C-induced expression of IFN-regulatory factor 9 and several antiviral IFNstimulated genes, including ISG15, ISG56, myxovirus resistance A, and 2'-5'-oligoadenylate synthetase 1, which encode the key antiviral elements in the IFN signaling pathway. CONCLUSION Our observations provide experimental evidence that EGCG has the ability to enhance poly I:C-induced intracellular antiviral innate immunity against HCV replication in hepatocytes.
基金funded by the National Natural Science Foundation of China,No.81803937(to YCM and QXD)Science and Technology Innovation Activity Plan for College Students of Zhejiang Province(Xinmiao Talent Plan),No.2020R413079(to AQZ)Wenzhou Science and Technology Plan Project,No.Y20210122(to QXD)。
文摘Previous studies have suggested that miR-324-3p is related to the pathophysiology of cerebral ischemia,but the mechanism underlying this relationship is unclea r.In this study,we found that miR-324-3p expression was decreased in patients with acute ischemic stroke and in in vitro and in vivo models of ischemic stro ke.miR-324-3p agomir potentiated ischemic brain damage in rats subjected to middle cerebral artery occlusion,as indicated by increased infarct volumes and cell apoptosis rates and greater neurological deficits.In a PC12 cell oxygen-glucose deprivation/reoxygenation model,a miR-324-3 p mimic decreased cell viability and expression of the anti-apoptotic protein BCL2 and increased expression of the pro-apoptotic protein BAX and rates of cell apoptosis,whereas treatment with a miR-324-3p inhibitor had the opposite effects.Silencing miR-324-3p increased adenosine A1 receptor(A1R)expression thro ugh regulation of GATA binding protein 2(GATA2).These findings suggest that silencing miR-324-3p reduces ischemic brain damage via the GATA2/A1R axis.
基金supported by National Natural Science Foundation of China(No.30271500)Science and Tech-nology Research Project Fund from the Department of Edu-cation of Hubei Province of China(No.B20115101)
文摘This study investigated the modulatory effect of synthetic cannabinoids WIN55,212-2 on 5-HT3 receptor-activated currents (I5-HT3) in cultured rat trigeminal ganglion (TG) neurons using whole-cell patch clamp technique. The results showed that: (1) The majority of examined neurons (78.70%) were sensitive to 5-HT (3–300 μmol/L). 5-HT induced inward currents in a concentration-dependent manner and the currents were blocked by ICS 205-930 (1 μmol/L), a selective antagonist of the 5-HT3 receptor; (2) Pre-application of WIN55,212-2 (0.01–1 μmol/L) significantly inhibited I5-HT3 reversibly in concentration-dependent and voltage-independent manners. The concentra-tion-response curve of 5-HT3 receptor was shifted downward by WIN55,212-2 without any change of the threshold value. The EC50 values of two curves were very close (17.5±4.5) mmol/L vs. (15.2±4.5) mmol/L and WIN55,212-2 decreased the maximal amplitude of I5-HT3 by (48.65±4.15)%; (3) Neither AM281, a selective CB1 receptor antagonist, nor AM630, a selective CB2 receptor antagonist reversed the inhibition of I5-HT3 by WIN55,212-2; (4) When WIN55,212-2 was given from 15 to 120 s before 5-HT application, inhibitory effect was gradually increased and the maximal inhibition took place at 90 s, and the inhibition remained at the same level after 90 s. We are led to concluded that-WIN55,212-2 inhibited I5-HT3 significantly and neither CB1 receptor antagonist nor CB2 receptor antagonist could reverse the inhibition of I5-HT3 by WIN55,212-2. Moreover, WIN55,212-2 is not an open channel blocker (OCB) of 5-HT3 receptor. WIN55,212-2 significantly inhibited 5-HT-activated currents in a non-competitive manner. The inhibition of I5-HT3 by WIN55,212-2 is probably new one of peripheral analgesic mechanisms of WIN55,212-2, but the mechanism by which WIN55,212-2 inhibits I5-HT3 warrants further investigation.
文摘Mangoes (Mangifera indica L.) are one of the most important tropical foods. The seed is one of the main by-products of mango processing. Therefore, it is important to find an economically viable use for this waste (e.g., as a food additive or supplement with high nutraceutical value). We investigated the anti-obesity effects of mango seed kernel extract with hot water (MSKE-W) in 3T3-L1 adipocytes and in a high fat diet (HFD)-induced obesity rat model. MSKE-W caused a significant decrease in the activity of glycerol 2-phosphate dehydrogenase in 3T3-L1 adipocytes without eliciting cell cytotoxicity and inhibited cellular lipid accumulation through down-regulation of transcription factors such as PPARγ and C/EBPα. In the animal model, rats fed an HFD containing 1% MSKE-W gained less weight than rats fed an HFD alone. The visceral fat mass in rats fed an HFD containing 1% MSKE-W tended to be lower than that in rats fed an HFD alone. Furthermore, histological examination of rat livers from an HFD showed steatohepatitis. However, rats on an HFD containning 1% MSKE-W showed no histopathological changes in liver tissue. Our results indicate that MSKE-W influences anti-obesity effects, both in vitro and in vivo, and suggest that MSKE-W provides a novel preventive potential against obesity.
基金Project supported by the National High-Tech R&D Program(863)of China(No.2006AA10Z136)a Grant-in-Aid for Innovative Training of Doctoral Students in Jiangsu Province of China(No.CXLX11-0701)
文摘We cloned the complete coding sequences of porcine Gpr3, Gpr6, and Gpr12 genes. Further, on the basis of their high levels of sequence similarity, these genes are identified as a subfamily of G protein-coupled receptors. These putative protein sequences also showed high sequence identity with other mammalian orthologs, including several highly conserved motifs. A wide expression of the Gpr3 gene in pigs was observed through tissue distribution analysis by reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time PCR, specially in the brain, pituitary, fat, liver and oocyte, where its strong expression was observed. The Gpr3 gene was found to be located on chromosome 6 and a single exon coded for the entire open reading frame. Expression of porcine Gpr3 in HEK293 cells resulted in constitutive activation of adenylate cyclase (AC) similar in amplitude to that produced by fully stimulated Gs coupled receptors. Moreover, sphingosine 1-phosphate (S1P) could increase AC activation via the constitutively active Gpr3 receptor. When a Gpr3-green fluorescent protein (GFP) construct was expressed in HEK293 cells, GFP-labeled Gpr3 protein was shown to be localized in the plasmalemma and subcellular membranes. After S1P treatment, agonist-mediated internalization could be visualized by confocal microscopy. In short, our findings suggest the porcine Gpr3, Gpr6, and Gpr12 genes as a subfamily of G protein-coupled receptors, and porcine Gpr3 was a constitutively active G protein-coupled receptor. Constitutive activation of AG and agonist-mediated internalization of Gpr3 receptor could be modulated by the S1 P, suggesting that S1P might act as an activator for porcine Gpr3 receptor.
基金This work was supported,in part,by grants from the National Health Research Institutes,Taiwan(EOPP10-014 and EOSP07-014 to S.-K.H.)Kaohsiung Medical University“The Talent Plan”(105KMUOR04 to S.-K.H.)+6 种基金the Ministry of Science and Technology,Taiwan(MOST 105-2320-B-039-004 and MOST 106-2320-B-039-037,to H.-C.W.)China Medical University Hospital,Taiwan(DMR-106-154 and DMR-107-117,to H.-C.W.)the Community Medicine Research Center,Chang Gung Memorial Hospital at Keelung(CMRPG3E1183 to L.-C.C.)the 1000 Young Talents Plan Program,China(to Y.Z.)the Initial Funding for New PI,Fudan Children’s Hospital and Fudan University(to Y.Z.)the National Natural Science Foundation of China(81671561,to Y.Z.)the National Key Research and Development Program of China(2016YFC1305102,to Y.Z.)。
文摘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.
基金the National Natural Science Foundation of China(No.81400333).
文摘The role of B7-1 in podocyte injury has received increasing attention.The aim of this study was to investigate whether losartan protects podocytes of patients with diabetic kidney disease(DKD)by regulating B7-1 and the underlying mechanisms.Rats with streptozotocin-induced DKD were treated with losartan for 8 weeks.Biochemical changes in blood and urine were analyzed.Kidneys were isolated for electron microscopy,immunofluorescence,real-time quantitative PCR(RT-PCR),and Western blot analysis.Immortalized mouse podocyte cells were cultured in normal or high glucose medium in the presence or absence of losartan for 48 h,and then the cells were collected for immunofluorescence,PCR,Western blotting and monolayer permeability detection.The phosphatidylinositol 3-kinase(PI3K)110a subunit and angiotensin II type 1 receptor(AT1R)plasmids were transfected into podocytes,respectively,and then Western blotting was performed to assess the expression of B7-1 protein.The results showed that losartan ameliorated podocyte structure and function in the rat model of DKD,and reduced the expression of B7-1 protein.Overexpression of PI3K 110a subunit in podocytes attenuated the inhibitory effect of losartan on B7-1 expression in high glucose-stimulated podocytes.The expression of B7-1 was significantly increased by overexpression of ATI R and significantly reduced by blocking PI3K 110a subunit.We conclude that losartan protects podocytes against high glucose-induced injury by inhibiting AT1R-mediated B7-1 expression.This effect is dependent on the AT1R-PI3K 110a subunit pathway.
文摘Most hematopoietic stem progenitor cells (HSPCs) reside in bone marrow (BM), but a small amount of HSPCs have been found to circulate between BM and tissues through blood and lymph. Several lines of evidence suggest that sphingosine-1-phosphate (S1P) gradient triggers HSPC egression to blood circulation after mobilization from BM stem cell niches. Stem cells also visit certain tissues. After a temporary 36 h short stay in local tissues, HSPCs go to lymph in response to S1P gradient between lymph and tissue and eventually enter the blood circulation. S1P also has a role in the guidance of the primitive HSPCs homing to BM in vivo, as S1P analogue FTY720 treatment can improve HSPC BM homing and engraftment. In stress conditions, various stem cells or progenitor cells can be attracted to local injured tissues and participate in local tissue cell differentiation and tissue rebuilding through modulation the expression level of S1P1, S1P2 or S1P3 receptors. Hence, S1P is important for stem cells circulation in blood system to accomplish its role in body surveillance and injury recovery.
基金This work was supported by the USA National Institutes of Health(NIH)grants R01 DK104893 and R01DK-057543VA Merit Award I01BX004033 and 1I01BX001390Research Career Scientist Award(IK6BX004477)from the Department of Veterans Affairs.
文摘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.
文摘BACKGROUND Remarkable progress over the last decade has equipped clinicians with many options in the treatment of inflammatory bowel disease.Clinicians now have the unique opportunity to provide individualized treatment that can achieve and sustain remission in many patients.However,issues of primary non-response(PNR)and secondary loss of response(SLOR)to non-tumour necrosis factor inhibitor(TNFi)therapies remains a common problem.Specific issues include the choice of optimization of therapy,identifying when dose optimization will recapture response,establishing optimal dose for escalation and when to switch therapy.AIM To explores the issues of PNR and SLOR to non-TNFi therapies.METHODS This review explores the current evidence and literature to elucidate management options in cases of PNR/SLOR.It will also explore potential predictors for response following SLOR/PNR to therapies including the role of therapeutic drug monitoring(TDM).RESULTS In the setting of PNR and loss of response to alpha-beta7-integrin inhibitors and interleukin(IL)-12 and IL-23 inhibitors dose optimization is a reasonable option to capture response.For Janus kinase inhibitors dose optimization can be utilized to recapture response with loss of response.CONCLUSION The role of TDM in the setting of advanced non-TNFi therapies to identify patients who require dose optimization and as a predictor for clinical remission is not yet established and this remains an area that should be addressed in the future.
基金Supported by the National Natural Science Foundation of China(Grant No.20401004)the Analysis and Test fund of Beijing Normal University
文摘5-HT_(1A)receptor is associated with a variety of pathophysiology of neuropsychiatric disorders.Accordingly,we have synthesized a new 5-HT_(1A) receptor ligand(HYNIC-MPP4)and labeled it with^(99m)Tc using N-(2-hydroxyethyl)ethylenediaminetriacetic acid(HEDTA)as coligand.^(99m)Tc-HEDTA/HYNIC-MPP4 was prepared under pH 6 at room temperature.Biodistribution of^(99m)Tc-HEDTA/HYNIC-MPP4 in normal mice showed that this complex had moderate brain uptake(0.60%ID·g^(-1)at 2 min p.i.)and good retention.The hippocampus had the highest radioactivity uptake at 2 min p.i.(1.84%ID·g^(-1)).The ratio of Hipp/CB was 3.1 at 2 min p.i.and increased to 4.4 at 60 min p.i.After blocking with 8-hydroxy-2-(dipropylamino)tetralin,the uptake of hippocampus was decreased significantly from 1.84%ID·g^(-1) to 0.53%ID·g^(-1) at 2 min p.i.,while the cerebellum had no significant decrease.This^(99m)Tc complex could be a potent agent for 5-HT_(1A) receptor imaging.
基金supported by grants from the National Natural Science Foundation of China,No.81971231(to JL)Liaoning Revitalization Talents Program,No.XLYC1907178(to JL)。
文摘Recent research on the underlying mechanisms of cerebral ischemia indicates that the neurovascular unit can be used as a novel subject for general surveys of neuronal damage and protein mechanisms.Fingolimod(FTY-720)is a newly developed immunosuppressant isolated from Cordyceps sinensis that exhibits a wide range of biological activities,and has recently attracted much attention for the treatment of ischemic cerebrovascular diseases.In the current research,the role of FTY-720 and its possible mechanisms were assessed from an neurovascular unit perspective using a rat cerebral ischemia model.Our results revealed that FTY-720 markedly decreased infarct volume,promoted neurological function recovery,and weakened the blood-brain barrier permeability of ischemic rats.The protective roles of FTY-720 in ischemic stroke are ascribed to a combination of sphingosin-1-phosphate receptor-1 and reduced expression of sphingosin-1-phosphate receptor-1 in microvessels and reduction of interleukin-17A protein levels.These findings indicate that FTY-720 has promise as a new therapy for neurovascular protection and functional recovery after ischemic stroke.
基金supported by National Key Research&Development Program from the Ministry of Science and Technology of the PRC(No.2019YFE0111800,China)National Natural Science Foundation of China(No.81872923,China)+1 种基金Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences(No.2021-JKCS-016,China)The Science and Technology Development Fund,Macao SAR(No.0074/2019/AMJ,China).
文摘Idiopathic pulmonary fibrosis(IPF)is a progressive lung disease with unclear etiology and limited treatment options.The median survival time for IPF patients is approximately 2–3 years and there is no effective intervention to treat IPF other than lung transplantation.As important components of lung tissue,endothelial cells(ECs)are associated with pulmonary diseases.However,the role of endothelial dysfunction in pulmonary fibrosis(PF)is incompletely understood.Sphingosine-1-phosphate receptor 1(S1PR1)is a G protein-coupled receptor highly expressed in lung ECs.Its expression is markedly reduced in patients with IPF.Herein,we generated an endothelial-conditional S1pr1 knockout mouse model which exhibited inflammation and fibrosis with or without bleomycin(BLM)challenge.Selective activation of S1PR1 with an S1PR1 agonist,IMMH002,exerted a potent therapeutic effect in mice with bleomycin-induced fibrosis by protecting the integrity of the endothelial barrier.These results suggest that S1PR1 might be a promising drug target for IPF therapy.