Objective To verify the regulation of acyl-coenzyme A:cholesterol acyltransferase 2 (ACAT 2), which is associated with cholesterol metabolism, by saturated fatty acids (SFAs). Methods Palmitic acid (PA), the most abun...Objective To verify the regulation of acyl-coenzyme A:cholesterol acyltransferase 2 (ACAT 2), which is associated with cholesterol metabolism, by saturated fatty acids (SFAs). Methods Palmitic acid (PA), the most abundant saturated fatty acid in plasma, and oleic acid (OA), a widely distributed unsaturated fatty acid, were used to treat hepatic cells HepG2, HuH7, and mouse primary hepatocytes. In addition, PA at different concentrations and PA treatment at different durations were applied in HepG2 cells. In in vivo experiment, three-month male C57/BL6 mice were fed with control diet and SFA diet containing hydrogenated coconut oil rich of SFAs. The mRNA level of ACAT2 in those hepatic cells and the mouse livers was detected with real-time polymerase chain reaction (PCR). Results In the three types of hepatic cells treated with PA, that SFA induced significant increase of ACAT2 expression (P<0.01), whereas treatment with OA showed no significant effect. That effect of PA was noticed gradually rising along with the increase of PA concentration and the extension of PA treatment duration (both P<0.05). SFA diet feeding in mice resulted in a short-term and transient increase of ACAT2 expression in vivo, with a peak level appearing in the mice fed with SFA diet for two days (P<0.05). Conclusion SFA may regulate ACAT2 expression in human and mouse hepatic cells and in mouse livers.展开更多
AIM: To examine the expression of Sph K1, an oncogenic kinase that produces sphingosine 1-phosphate(S1P), and its correlation with the expression of LPAR2, a major lysophosphatidic acid(LPA) receptor overexpressed in ...AIM: To examine the expression of Sph K1, an oncogenic kinase that produces sphingosine 1-phosphate(S1P), and its correlation with the expression of LPAR2, a major lysophosphatidic acid(LPA) receptor overexpressed in various cancers, in human colorectal cancer.METHODS: Real-time reverse-transcription polymerase chain reaction was used to measure the m RNA expression of Sph K1, LPAR2, and the three major S1 P receptors in 27 colorectal cancer samples and corresponding normal tissue samples. We also examined the correlation between the expression of Sph K1 and LPAR2.RESULTS: C o l o r e c t a l c a n c e r t i s s u e i n 2 2 o f 2 7 patients had higher levels of Sph K1 m RNA than in normal tissue. In two-thirds of the samples, Sph K1 m RNA expression was more than two-fold higher than in normal tissue. Consistent with previous reports, LPAR2 m RNA expression in 20 of 27 colorectal cancer tissue samples was higher compared to normal tissue samples. Expression profiles of all three major S1 P receptors, S1PR1, S1PR2, and S1PR3, varied without any trend, with no significant difference in expression between cancer and normal tissues. A highly significant positive correlation was found between Sph K1 and LPAR2 expression [Pearson's correlation coefficient(r) = 0.784 and P < 0.01]. The m RNA levels of Sph K1 and LPAR2 did not correlate with TNM stage.CONCLUSION: Our findings suggest that S1 P andLPA may play important roles in the development ofcolorectal cancer via the upregulation of Sph K1 andLPAR2, both of which could serve as new therapeutictargets in the treatment of colorectal cancer.展开更多
Lysophosphatidic acid(LPA), a glycerophospholipid, consists of a glycerol backbone connected to a phosphate head group and an acyl chain linked to sn-1 or sn-2 position. In the circulation, LPA is in submillimolar ran...Lysophosphatidic acid(LPA), a glycerophospholipid, consists of a glycerol backbone connected to a phosphate head group and an acyl chain linked to sn-1 or sn-2 position. In the circulation, LPA is in submillimolar range and mainly derived from hydrolysis of lysophosphatidylcholine, a process mediated by lysophospholipase D activity in proteins such as autotaxin(ATX). Intracellular and extracellular LPAs act as bioactive lipid mediators with diverse functions in almost every mammalian cell type. The binding of LPA to its receptors LPA1-6 activates multiple cellular processes such as migration, proliferation and survival. The production of LPA and activation of LPA receptor signaling pathways in the events of physiology and pathophysiology have attracted the interest of researchers. Results from studies using transgenic and gene knockout animals with alterations of ATX and LPA receptors genes, have revealed the roles of LPA signaling pathways in metabolic active tissues and organs. The present review was aimed to summarize recent progresses in the studies of extracellular and intracellular LPA production pathways. This includes the functional, structural and biochemical properties of ATX and LPA receptors. The potential roles of LPA production and LPA receptor signaling pathways in obesity, insulin resistance and liver fibrosis are also discussed.展开更多
Despite their potential applications in future regenerative medicine, periodontal ligament stem cells(PDLSCs) are difficult to obtain in large amounts from patients. Therefore, maintaining sternness while expanding th...Despite their potential applications in future regenerative medicine, periodontal ligament stem cells(PDLSCs) are difficult to obtain in large amounts from patients. Therefore, maintaining sternness while expanding the cell numbers for medical use is the key to transitioning PDLSCs from the bench to the clinic. Lysophosphatidic acid(LPA), which is present in the human body and saliva, is a signaling molecule derived from phospholipids. In this study, we examined the effects of LPA on sternness maintenance in human PDLSCs. Several spindle-shaped and fibroblast-like periodontal ligament stem-like cell lines were established from PDLSC isolation. Among these cell lines, the most morphologically appropriate cell line was characterized. The expression levels of OCT4, NANOG(a stem cell marker), and CD90(a mesenchymal stem cell marker) were high. However, CD73(a negative marker of mesenchymal stem cells) expression was not observed. Notably, immunofluorescence analysis identified the expression of STRO-1, CD146(a mesenchymal stem cell marker), and sex determining region Y-box 2 at the protein level. In addition, lipid droplets were stained by Oil red O after the induction of adipogenesis for 21 days, and mineralized nodules were stained by Alizarin Red S after the induction of osteogenesis for 14 days. Alkaline phosphate staining also demonstrated the occurrence of osteogenesis. In summary, we established a human PDLSC line, which could be applied as a cell source for tissue regeneration in dental patients. However, further studies are needed to determine the detailed effects of LPA on PDLSCs.展开更多
AIM:To study the effects of lysophosphatidic acid(LPA) on proliferation,adhesion,migration,and apoptosis in the human colon cancer cell line,SW480,and its mechanisms of action. METHODS:Methyl tetrazolium assay was use...AIM:To study the effects of lysophosphatidic acid(LPA) on proliferation,adhesion,migration,and apoptosis in the human colon cancer cell line,SW480,and its mechanisms of action. METHODS:Methyl tetrazolium assay was used to assess cell proliferation.Flow cytometry was employed to detect cell apoptosis.Cell migration was measured by using a Boyden transwell migration chamber.Cell adhesion assay was performed in 96-well plates according to protocol. RESULTS:LPA significantly stimulated SW480 cell proliferation in a dose-dependent and time-dependent manner compared with the control group(P<0.05) while the mitogen-activated protein kinase(MAPK)inhibitor,PD98059,significantly blocked the LPA stimulation effect on proliferation.LPA also significantly stimulated adhesion and migration of SW480 cells in a dosedependent manner(P<0.05).Rho kinase inhibitor, Y-27632,significantly inhibited the up-regulatory effect of LPA on adhesion and migration(P<0.05).LPA significantly protected cells from apoptosis induced by the chemotherapeutic drugs,cisplatin and 5-FU(P<0.05), but the phosphoinositide 3-kinase(PI3K)inhibitor, LY294002,significantly blocked the protective effect of LPA on apoptosis. CONCLUSION:LPA stimulated proliferation,adhesion,migration of SW480 cells,and protected from apoptosis.The Ras/Raf-MAPK,G12/13-Rho-RhoA and PI3K- AKT/PKB signal pathways may be involved.展开更多
Objective: To observe the effect of Yangxueqingnao particles on rat vascular smooth muscle cell (VSMC) prolif- eration induced by lysophosphatidic acid (LPA). Methods: The amount of 3H-TdR (3H-thymidine) admixed in cu...Objective: To observe the effect of Yangxueqingnao particles on rat vascular smooth muscle cell (VSMC) prolif- eration induced by lysophosphatidic acid (LPA). Methods: The amount of 3H-TdR (3H-thymidine) admixed in cultured rat VSMC was measured and mitogen-activated protein kinase (MAPK) activity and lipid peroxidation end product malondialdehyde (MDA) content of the VSMC were assayed. Results: 1×10?9, 1×10?8, 1×10?7 mol/L LPA in a concentration dependent manner, induced the amount of 3H-TdR admixed, MAP kinase activity, and MDA content of the cultured rat VSMC to increase. However, 5%, 10%, and 15% Yangxueqingnao serum preincubation resulted in a decrease of 23.0%, 42.0%, and 52.0% (P<0.01) respectively in the amount of 3H-TdR admixed, a decline in VSMC MAP kinase activity of 13.9% (P<0.05), 29.6% (P<0.01), and 48.9% (P<0.01) respectively, and also, a decrease in MDA content of VSMC of 19.4%, 24.7%, and 43.2% (P<0.01) respectively, in the 1×10?7 mol/L LPA-treated VSMC. Conclusions: LPA activates the proliferation and lipid peroxidation of VSMC in a concentration dependent manner. The LPA-induced VSMC proliferation is related to the activity of MAP kinases, enzymes involved in an intracellular signalling pathway. The results of the present study showed that Yangxueqingnao particles can effectively inhibit LPA-induced VSMC proliferation, MAP kinase activation, and reduce lipid peroxidative lesion.展开更多
The KAI1/CD82 gene inhibits the metastasis of most tumors and is remarkably correlated with tumor invasion and prognosis.Cell metabolism dysregulation is an important cause of tumor occurrence,development,and metastas...The KAI1/CD82 gene inhibits the metastasis of most tumors and is remarkably correlated with tumor invasion and prognosis.Cell metabolism dysregulation is an important cause of tumor occurrence,development,and metastasis.As one of the important characteristics of tumors,cell metabolism dysregulation is attracting increasing research attention.Phospholipids are an indispensable substance in the metabolism in various tumor cells.Phospholipid metabolites have become important cell signaling molecules.The pathological role of lysophosphatidic acid(LPA)in tumors was identified in the early 1990s.Currently,LPA inhibitors have entered clinical trials but are not yet used in clinical treatment.Autotaxin(ATX)has lysophospholipase D(lysoPLD)activity and can regulate LPA levels in vivo.The LPA receptor family and ATX/lysoPLD are abnormally expressed in various gastrointestinal tumors.According to our recent pre-experimental results,KAI1/CD82 might inhibit the migration and metastasis of cancer cells by regulating the ATX-LPA axis.However,no relevant research has been reported.Clarifying the mechanism of ATX-LPA in the inhibition of cancer metastasis by KAI1/CD82 will provide an important theoretical basis for targeted cancer therapy.In this paper,the molecular compositions of the KAI1/CD82 gene and the ATX-LPA axis,their physiological functions in tumors,and their roles in gastrointestinal cancers and target therapy are reviewed.展开更多
AIM: To examine whether lysophosphatidic acid (LPA)induces phosphorylation of c-Met and epidermal growth factor receptor (EGFR), both of which have been proposed as prognostic markers of colorectal cancer, and whether...AIM: To examine whether lysophosphatidic acid (LPA)induces phosphorylation of c-Met and epidermal growth factor receptor (EGFR), both of which have been proposed as prognostic markers of colorectal cancer, and whether LPA induces cyclooxygenase-2 (COX-2) expression in human colon cancer cells.METHODS: Using a human colon cancer cell line, LoVo cells, we performed immunoprecipitation analysis,followed by Western blot analysis. We also examined whether LPA induced COX-2 expression, by Western blot analysis.RESULTS: Immunoprecipitation analysis revealed that 10 μmol/L LPA induced tyrosine phosphorylation of c-Met and EGFR in LoVo cells within a few minutes. We found that c-Met tyrosine phosphorylation induced by LPA was not attenuated by pertussis toxin or a matrix metalloproteinase inhibitor, in marked contrast to the results for EGFR. In addition, 0.2-40 μmol/L LPA induced COX-2 expression in a dose-dependent manner.CONCLUSION: Our results suggest that LPA acts upstream of various receptor tyrosine kinases (RTKs) and COX-2,and thus may act as a potent stimulator of colorectal cancer.展开更多
AIM: To clarify whether Lysophosphatidic acid (LPA) activates the nuclear translocation of nuclear factor-κB (NF-κB) in pancreatic cancer. METHODS: Panc-1, a human pancreatic cancer cell line, was used throughout th...AIM: To clarify whether Lysophosphatidic acid (LPA) activates the nuclear translocation of nuclear factor-κB (NF-κB) in pancreatic cancer. METHODS: Panc-1, a human pancreatic cancer cell line, was used throughout the study. The expression of LPA receptors was confirmed by reverse-transcript polymerase chain reaction (RT-PCR). Cytosolic free calcium was measured by fluorescent calcium indicator fura-2, and the localization of NF-κB was visualized by immunofluorescent method with or without various agents, which effect cell signaling. RESULTS: Panc-1 expressed LPA receptors, LPA1, LPA2 and LPA3. LPA caused the elevation of cytosolic free calcium dose-dependently. LPA also caused the nuclear translocation of NF-κB. Cytosolic free calcium was attenuated by pertussis toxin (PTX) and U73122, an inhibitor of phospholipase C. The translocation of NF-κB was similarly attenuated by PTX and U73122, but phorbol ester, an activator of protein kinase C, alone did not translocate NF-κB. Furthermore, the translocation of NF-κB was completely blocked by Ca2+ chelator BAPTA-AM. Thapsigargin, an endoplasmic- reticulum Ca2+-ATPase pump inhibitor, also promoted the translocation of NF-κB. Staurosporine, a proteinkinase C inhibitor, attenuated translocation of NF-κB induced by LPA. CONCLUSION: These findings suggest that protein kinase C is activated endogenously in Panc-1, and protein kinase C is essential for activating NF-κB with cytosolic calcium and that LPA induces the nuclear translocation of NF-κB in Panc-1 by mobilizing cytosolic free calcium.展开更多
Autotaxin(ATX or ENPP2) is a secreted glycoprotein widely present in biological fluids. ATX primarily functions as a plasma lysophospholipase D and is largely responsible for the bulk of lysophosphatidic acid(LPA) pro...Autotaxin(ATX or ENPP2) is a secreted glycoprotein widely present in biological fluids. ATX primarily functions as a plasma lysophospholipase D and is largely responsible for the bulk of lysophosphatidic acid(LPA) production in the plasma and at inflamed and/or malignant sites. LPA is a phospholipid mediator produced in various conditions both in cells and in biological fluids, and it evokes growth-factor-like responses, including cell growth, survival, differentiation and motility, in almost all cell types. The large variety of LPA effector functions is attributed to at least six G-protein coupled LPA receptors(LPARs) with overlapping specificities and widespread distribution. Increased ATX/LPA/LPAR levels have been detected in a large variety of cancers and transformed cell lines, as well as in non-malignant inflamed tissues, suggesting a possible involvement of ATX in chronic inflammatory disorders and cancer. In this review, we focus exclusively on the role of the ATX/LPA axis in pulmonary pathophysiology, analysing the effects of ATX/LPA on pulmonary cells and leukocytes in vitro and in the context of pulmonary pathophysi-ological situations in vivo and in human diseases.展开更多
目的探讨与分析脑梗死(cerebral infarction,CI)患者脑脊液溶血磷脂酸(plasma lysophosphatidic acid,LPA)水平与神经功能缺损状态的相关性分析。方法选择2020年3月—2022年11月在北京市昌平区中西医结合医院诊治的67例脑梗死患者作为...目的探讨与分析脑梗死(cerebral infarction,CI)患者脑脊液溶血磷脂酸(plasma lysophosphatidic acid,LPA)水平与神经功能缺损状态的相关性分析。方法选择2020年3月—2022年11月在北京市昌平区中西医结合医院诊治的67例脑梗死患者作为研究对象,所有患者在入院时进行神经功能缺损状态美国国立卫生研究院卒中量表(National Institute of Health Stroke Scale,NIHSS)评分,检测脑脊液溶血磷脂酸水平并进行相关性分析。结果在67例患者中,平均神经功能缺损状态NIHSS评分为(18.32±2.15)分,其中>21分17例(重度组)。重度组性别、身体质量指数、受教育程度、合并疾病等与非重度组对比,差异无统计学意义(P>0.05),重度组与非重度组的年龄、发病到入院时间等对比,差异有统计学意义(P<0.05)。重度组与非重度组的血糖、同型半胱氨酸、总胆固醇、甘油三酯含量对比,差异无统计学意义(P>0.05),重度组的低密度脂蛋白胆固醇含量高于非重度组,差异有统计学意义(P<0.05)。重度组的脑脊液溶血磷脂酸水平显著高于非重度组,差异有统计学意义(P<0.05)。Pearson分析显示NIHSS评分与年龄、发病到入院时间、脑脊液溶血磷脂酸水平都存在正相关性(P<0.05)。logistic回归分析显示年龄、发病到入院时间、脑脊液溶血磷脂酸水平为影响脑梗死患者NIHSS评分的重要因素(P<0.05)。结论脑梗死患者的神经功能缺损状态比较严重,神经功能缺损状态越差的脑梗死患者,脑脊液溶血磷脂酸水平越高,脑梗死患者脑脊液溶血磷脂酸水平与神经功能缺损状态存在相关性。展开更多
ABSTRACT:Two separate studies tested the hypoth- esis that plasma low-density lipoprotein cholesterol LDL-C ) can be decreased by conjugated linoleic acid (CLA) by depressing hepatic acyl-coenzyme A: cholesterol...ABSTRACT:Two separate studies tested the hypoth- esis that plasma low-density lipoprotein cholesterol LDL-C ) can be decreased by conjugated linoleic acid (CLA) by depressing hepatic acyl-coenzyme A: cholesterol acyltransferase (ACAT) activity. In the first experiment, 3 groups of 6 early-weaned piglets were fed low-fat diets containing either 1.5% CLA, 1.5% corn oil or 1.5% beef tallow;fat provided 8% of the energy intake. In the second experiment, 4 groups of 6 early-weaned piglets were fed high-fat di- ets containing either 15% beef tallow, 12% beef tal- low plus 3% CLA, 15% corn oil, or 12% corn oil plus 3% CLA; fat provided 29% of energy intake. Cholesterol was balanced across diets in both experi-ments. In pigs fed the low-fat diets, all dietary fats in- creased LDL-C and triacylglycerols and decreased high-density lipoprotein cholesterol ( HDL-C ) and very low-density lipoprotein cholesterol (VLDL-C). LDL-C was the same in pigs fed low-fat tallow or low-fat CLA diets. However, ACAT activity was near- ly 80% higher in pigs fed the low-fat tallow diet than in pigs fed the low-fat CLA diets. All high-fat diets increased LDL-C, HDL-C and triacylglycerols equally with no effect on VLDL-C. There were no unique fat- ty acid effects of the high-fat diets on ACAT activity. We conclude that supplemental fats had differential effects on hepatic ACAT activity and LDL-C, but on- ly in pigs fed low-fat diets.展开更多
基金Supported by National Natural Science Foundation of China (30721063)National High Technology Research and Development Program of China (863 Program) (2006AA02A406)+1 种基金National Basic Research Program of China (973 Program) (2006CB503801)Special Fund of the National Laboratory of China (2060204)
文摘Objective To verify the regulation of acyl-coenzyme A:cholesterol acyltransferase 2 (ACAT 2), which is associated with cholesterol metabolism, by saturated fatty acids (SFAs). Methods Palmitic acid (PA), the most abundant saturated fatty acid in plasma, and oleic acid (OA), a widely distributed unsaturated fatty acid, were used to treat hepatic cells HepG2, HuH7, and mouse primary hepatocytes. In addition, PA at different concentrations and PA treatment at different durations were applied in HepG2 cells. In in vivo experiment, three-month male C57/BL6 mice were fed with control diet and SFA diet containing hydrogenated coconut oil rich of SFAs. The mRNA level of ACAT2 in those hepatic cells and the mouse livers was detected with real-time polymerase chain reaction (PCR). Results In the three types of hepatic cells treated with PA, that SFA induced significant increase of ACAT2 expression (P<0.01), whereas treatment with OA showed no significant effect. That effect of PA was noticed gradually rising along with the increase of PA concentration and the extension of PA treatment duration (both P<0.05). SFA diet feeding in mice resulted in a short-term and transient increase of ACAT2 expression in vivo, with a peak level appearing in the mice fed with SFA diet for two days (P<0.05). Conclusion SFA may regulate ACAT2 expression in human and mouse hepatic cells and in mouse livers.
基金Supported by Grant 2010 from Tokyo MetropolisJapan
文摘AIM: To examine the expression of Sph K1, an oncogenic kinase that produces sphingosine 1-phosphate(S1P), and its correlation with the expression of LPAR2, a major lysophosphatidic acid(LPA) receptor overexpressed in various cancers, in human colorectal cancer.METHODS: Real-time reverse-transcription polymerase chain reaction was used to measure the m RNA expression of Sph K1, LPAR2, and the three major S1 P receptors in 27 colorectal cancer samples and corresponding normal tissue samples. We also examined the correlation between the expression of Sph K1 and LPAR2.RESULTS: C o l o r e c t a l c a n c e r t i s s u e i n 2 2 o f 2 7 patients had higher levels of Sph K1 m RNA than in normal tissue. In two-thirds of the samples, Sph K1 m RNA expression was more than two-fold higher than in normal tissue. Consistent with previous reports, LPAR2 m RNA expression in 20 of 27 colorectal cancer tissue samples was higher compared to normal tissue samples. Expression profiles of all three major S1 P receptors, S1PR1, S1PR2, and S1PR3, varied without any trend, with no significant difference in expression between cancer and normal tissues. A highly significant positive correlation was found between Sph K1 and LPAR2 expression [Pearson's correlation coefficient(r) = 0.784 and P < 0.01]. The m RNA levels of Sph K1 and LPAR2 did not correlate with TNM stage.CONCLUSION: Our findings suggest that S1 P andLPA may play important roles in the development ofcolorectal cancer via the upregulation of Sph K1 andLPAR2, both of which could serve as new therapeutictargets in the treatment of colorectal cancer.
基金Supported by the National Natural Science Foundation of China,No.31401510
文摘Lysophosphatidic acid(LPA), a glycerophospholipid, consists of a glycerol backbone connected to a phosphate head group and an acyl chain linked to sn-1 or sn-2 position. In the circulation, LPA is in submillimolar range and mainly derived from hydrolysis of lysophosphatidylcholine, a process mediated by lysophospholipase D activity in proteins such as autotaxin(ATX). Intracellular and extracellular LPAs act as bioactive lipid mediators with diverse functions in almost every mammalian cell type. The binding of LPA to its receptors LPA1-6 activates multiple cellular processes such as migration, proliferation and survival. The production of LPA and activation of LPA receptor signaling pathways in the events of physiology and pathophysiology have attracted the interest of researchers. Results from studies using transgenic and gene knockout animals with alterations of ATX and LPA receptors genes, have revealed the roles of LPA signaling pathways in metabolic active tissues and organs. The present review was aimed to summarize recent progresses in the studies of extracellular and intracellular LPA production pathways. This includes the functional, structural and biochemical properties of ATX and LPA receptors. The potential roles of LPA production and LPA receptor signaling pathways in obesity, insulin resistance and liver fibrosis are also discussed.
基金supported,in part,by a grant from the"Korea Research Fellowship(KRF)Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(NRF-2015HlD3A1066175)"the"NRF Grant funded by the Ministry of Science and ICT(NRF-2016RIDIAIB-03933191,NRF-2017RIA2B4002546)"+1 种基金the"Global Research and Development Center(GRDC)Program through the NRF funded by the Ministry of Science and ICT(NRF-2017KlA4A3014959)""Korea Institute of Planning and Evaluation for Technology in Food,Agriculture,Forestry and Fisheries(IPET)through Agri-Bio industry Technology Development Program,funded by Ministry of Agriculture,Food and Rural Affairs(MAFRA)(318016-5)",Republic of Korea
文摘Despite their potential applications in future regenerative medicine, periodontal ligament stem cells(PDLSCs) are difficult to obtain in large amounts from patients. Therefore, maintaining sternness while expanding the cell numbers for medical use is the key to transitioning PDLSCs from the bench to the clinic. Lysophosphatidic acid(LPA), which is present in the human body and saliva, is a signaling molecule derived from phospholipids. In this study, we examined the effects of LPA on sternness maintenance in human PDLSCs. Several spindle-shaped and fibroblast-like periodontal ligament stem-like cell lines were established from PDLSC isolation. Among these cell lines, the most morphologically appropriate cell line was characterized. The expression levels of OCT4, NANOG(a stem cell marker), and CD90(a mesenchymal stem cell marker) were high. However, CD73(a negative marker of mesenchymal stem cells) expression was not observed. Notably, immunofluorescence analysis identified the expression of STRO-1, CD146(a mesenchymal stem cell marker), and sex determining region Y-box 2 at the protein level. In addition, lipid droplets were stained by Oil red O after the induction of adipogenesis for 21 days, and mineralized nodules were stained by Alizarin Red S after the induction of osteogenesis for 14 days. Alkaline phosphate staining also demonstrated the occurrence of osteogenesis. In summary, we established a human PDLSC line, which could be applied as a cell source for tissue regeneration in dental patients. However, further studies are needed to determine the detailed effects of LPA on PDLSCs.
文摘AIM:To study the effects of lysophosphatidic acid(LPA) on proliferation,adhesion,migration,and apoptosis in the human colon cancer cell line,SW480,and its mechanisms of action. METHODS:Methyl tetrazolium assay was used to assess cell proliferation.Flow cytometry was employed to detect cell apoptosis.Cell migration was measured by using a Boyden transwell migration chamber.Cell adhesion assay was performed in 96-well plates according to protocol. RESULTS:LPA significantly stimulated SW480 cell proliferation in a dose-dependent and time-dependent manner compared with the control group(P<0.05) while the mitogen-activated protein kinase(MAPK)inhibitor,PD98059,significantly blocked the LPA stimulation effect on proliferation.LPA also significantly stimulated adhesion and migration of SW480 cells in a dosedependent manner(P<0.05).Rho kinase inhibitor, Y-27632,significantly inhibited the up-regulatory effect of LPA on adhesion and migration(P<0.05).LPA significantly protected cells from apoptosis induced by the chemotherapeutic drugs,cisplatin and 5-FU(P<0.05), but the phosphoinositide 3-kinase(PI3K)inhibitor, LY294002,significantly blocked the protective effect of LPA on apoptosis. CONCLUSION:LPA stimulated proliferation,adhesion,migration of SW480 cells,and protected from apoptosis.The Ras/Raf-MAPK,G12/13-Rho-RhoA and PI3K- AKT/PKB signal pathways may be involved.
基金Project (No. 491010-W50339) supported by Chinese Traditional Medicine Administration Bureau of Zhejiang Province, China
文摘Objective: To observe the effect of Yangxueqingnao particles on rat vascular smooth muscle cell (VSMC) prolif- eration induced by lysophosphatidic acid (LPA). Methods: The amount of 3H-TdR (3H-thymidine) admixed in cultured rat VSMC was measured and mitogen-activated protein kinase (MAPK) activity and lipid peroxidation end product malondialdehyde (MDA) content of the VSMC were assayed. Results: 1×10?9, 1×10?8, 1×10?7 mol/L LPA in a concentration dependent manner, induced the amount of 3H-TdR admixed, MAP kinase activity, and MDA content of the cultured rat VSMC to increase. However, 5%, 10%, and 15% Yangxueqingnao serum preincubation resulted in a decrease of 23.0%, 42.0%, and 52.0% (P<0.01) respectively in the amount of 3H-TdR admixed, a decline in VSMC MAP kinase activity of 13.9% (P<0.05), 29.6% (P<0.01), and 48.9% (P<0.01) respectively, and also, a decrease in MDA content of VSMC of 19.4%, 24.7%, and 43.2% (P<0.01) respectively, in the 1×10?7 mol/L LPA-treated VSMC. Conclusions: LPA activates the proliferation and lipid peroxidation of VSMC in a concentration dependent manner. The LPA-induced VSMC proliferation is related to the activity of MAP kinases, enzymes involved in an intracellular signalling pathway. The results of the present study showed that Yangxueqingnao particles can effectively inhibit LPA-induced VSMC proliferation, MAP kinase activation, and reduce lipid peroxidative lesion.
基金Supported by the National Natural Science Foundation of China,No.81672465the Science and Technology Program of Liaoning Province,No.2019JH8/10300080。
文摘The KAI1/CD82 gene inhibits the metastasis of most tumors and is remarkably correlated with tumor invasion and prognosis.Cell metabolism dysregulation is an important cause of tumor occurrence,development,and metastasis.As one of the important characteristics of tumors,cell metabolism dysregulation is attracting increasing research attention.Phospholipids are an indispensable substance in the metabolism in various tumor cells.Phospholipid metabolites have become important cell signaling molecules.The pathological role of lysophosphatidic acid(LPA)in tumors was identified in the early 1990s.Currently,LPA inhibitors have entered clinical trials but are not yet used in clinical treatment.Autotaxin(ATX)has lysophospholipase D(lysoPLD)activity and can regulate LPA levels in vivo.The LPA receptor family and ATX/lysoPLD are abnormally expressed in various gastrointestinal tumors.According to our recent pre-experimental results,KAI1/CD82 might inhibit the migration and metastasis of cancer cells by regulating the ATX-LPA axis.However,no relevant research has been reported.Clarifying the mechanism of ATX-LPA in the inhibition of cancer metastasis by KAI1/CD82 will provide an important theoretical basis for targeted cancer therapy.In this paper,the molecular compositions of the KAI1/CD82 gene and the ATX-LPA axis,their physiological functions in tumors,and their roles in gastrointestinal cancers and target therapy are reviewed.
基金Supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan and a grant from the Ministry of Health, Labour and Welfare of Japan
文摘AIM: To examine whether lysophosphatidic acid (LPA)induces phosphorylation of c-Met and epidermal growth factor receptor (EGFR), both of which have been proposed as prognostic markers of colorectal cancer, and whether LPA induces cyclooxygenase-2 (COX-2) expression in human colon cancer cells.METHODS: Using a human colon cancer cell line, LoVo cells, we performed immunoprecipitation analysis,followed by Western blot analysis. We also examined whether LPA induced COX-2 expression, by Western blot analysis.RESULTS: Immunoprecipitation analysis revealed that 10 μmol/L LPA induced tyrosine phosphorylation of c-Met and EGFR in LoVo cells within a few minutes. We found that c-Met tyrosine phosphorylation induced by LPA was not attenuated by pertussis toxin or a matrix metalloproteinase inhibitor, in marked contrast to the results for EGFR. In addition, 0.2-40 μmol/L LPA induced COX-2 expression in a dose-dependent manner.CONCLUSION: Our results suggest that LPA acts upstream of various receptor tyrosine kinases (RTKs) and COX-2,and thus may act as a potent stimulator of colorectal cancer.
基金The Research Committee of Intractable Pancreatic Diseases, provided by the Ministry of Health, Labour, and Welfare, Japan, No. 50253448
文摘AIM: To clarify whether Lysophosphatidic acid (LPA) activates the nuclear translocation of nuclear factor-κB (NF-κB) in pancreatic cancer. METHODS: Panc-1, a human pancreatic cancer cell line, was used throughout the study. The expression of LPA receptors was confirmed by reverse-transcript polymerase chain reaction (RT-PCR). Cytosolic free calcium was measured by fluorescent calcium indicator fura-2, and the localization of NF-κB was visualized by immunofluorescent method with or without various agents, which effect cell signaling. RESULTS: Panc-1 expressed LPA receptors, LPA1, LPA2 and LPA3. LPA caused the elevation of cytosolic free calcium dose-dependently. LPA also caused the nuclear translocation of NF-κB. Cytosolic free calcium was attenuated by pertussis toxin (PTX) and U73122, an inhibitor of phospholipase C. The translocation of NF-κB was similarly attenuated by PTX and U73122, but phorbol ester, an activator of protein kinase C, alone did not translocate NF-κB. Furthermore, the translocation of NF-κB was completely blocked by Ca2+ chelator BAPTA-AM. Thapsigargin, an endoplasmic- reticulum Ca2+-ATPase pump inhibitor, also promoted the translocation of NF-κB. Staurosporine, a proteinkinase C inhibitor, attenuated translocation of NF-κB induced by LPA. CONCLUSION: These findings suggest that protein kinase C is activated endogenously in Panc-1, and protein kinase C is essential for activating NF-κB with cytosolic calcium and that LPA induces the nuclear translocation of NF-κB in Panc-1 by mobilizing cytosolic free calcium.
基金Supported by National Grants from the Hellenic Ministry of Education,Lifelong Learning and Religious Affairs,No.09SYN-12-679/680
文摘Autotaxin(ATX or ENPP2) is a secreted glycoprotein widely present in biological fluids. ATX primarily functions as a plasma lysophospholipase D and is largely responsible for the bulk of lysophosphatidic acid(LPA) production in the plasma and at inflamed and/or malignant sites. LPA is a phospholipid mediator produced in various conditions both in cells and in biological fluids, and it evokes growth-factor-like responses, including cell growth, survival, differentiation and motility, in almost all cell types. The large variety of LPA effector functions is attributed to at least six G-protein coupled LPA receptors(LPARs) with overlapping specificities and widespread distribution. Increased ATX/LPA/LPAR levels have been detected in a large variety of cancers and transformed cell lines, as well as in non-malignant inflamed tissues, suggesting a possible involvement of ATX in chronic inflammatory disorders and cancer. In this review, we focus exclusively on the role of the ATX/LPA axis in pulmonary pathophysiology, analysing the effects of ATX/LPA on pulmonary cells and leukocytes in vitro and in the context of pulmonary pathophysi-ological situations in vivo and in human diseases.
文摘目的探讨与分析脑梗死(cerebral infarction,CI)患者脑脊液溶血磷脂酸(plasma lysophosphatidic acid,LPA)水平与神经功能缺损状态的相关性分析。方法选择2020年3月—2022年11月在北京市昌平区中西医结合医院诊治的67例脑梗死患者作为研究对象,所有患者在入院时进行神经功能缺损状态美国国立卫生研究院卒中量表(National Institute of Health Stroke Scale,NIHSS)评分,检测脑脊液溶血磷脂酸水平并进行相关性分析。结果在67例患者中,平均神经功能缺损状态NIHSS评分为(18.32±2.15)分,其中>21分17例(重度组)。重度组性别、身体质量指数、受教育程度、合并疾病等与非重度组对比,差异无统计学意义(P>0.05),重度组与非重度组的年龄、发病到入院时间等对比,差异有统计学意义(P<0.05)。重度组与非重度组的血糖、同型半胱氨酸、总胆固醇、甘油三酯含量对比,差异无统计学意义(P>0.05),重度组的低密度脂蛋白胆固醇含量高于非重度组,差异有统计学意义(P<0.05)。重度组的脑脊液溶血磷脂酸水平显著高于非重度组,差异有统计学意义(P<0.05)。Pearson分析显示NIHSS评分与年龄、发病到入院时间、脑脊液溶血磷脂酸水平都存在正相关性(P<0.05)。logistic回归分析显示年龄、发病到入院时间、脑脊液溶血磷脂酸水平为影响脑梗死患者NIHSS评分的重要因素(P<0.05)。结论脑梗死患者的神经功能缺损状态比较严重,神经功能缺损状态越差的脑梗死患者,脑脊液溶血磷脂酸水平越高,脑梗死患者脑脊液溶血磷脂酸水平与神经功能缺损状态存在相关性。
基金Supported by USDA/CSREES Competitive Grant 98-35206-6286federal funds from the USDA,ARS under Cooperative Agreement no.58-6250-1-003
文摘ABSTRACT:Two separate studies tested the hypoth- esis that plasma low-density lipoprotein cholesterol LDL-C ) can be decreased by conjugated linoleic acid (CLA) by depressing hepatic acyl-coenzyme A: cholesterol acyltransferase (ACAT) activity. In the first experiment, 3 groups of 6 early-weaned piglets were fed low-fat diets containing either 1.5% CLA, 1.5% corn oil or 1.5% beef tallow;fat provided 8% of the energy intake. In the second experiment, 4 groups of 6 early-weaned piglets were fed high-fat di- ets containing either 15% beef tallow, 12% beef tal- low plus 3% CLA, 15% corn oil, or 12% corn oil plus 3% CLA; fat provided 29% of energy intake. Cholesterol was balanced across diets in both experi-ments. In pigs fed the low-fat diets, all dietary fats in- creased LDL-C and triacylglycerols and decreased high-density lipoprotein cholesterol ( HDL-C ) and very low-density lipoprotein cholesterol (VLDL-C). LDL-C was the same in pigs fed low-fat tallow or low-fat CLA diets. However, ACAT activity was near- ly 80% higher in pigs fed the low-fat tallow diet than in pigs fed the low-fat CLA diets. All high-fat diets increased LDL-C, HDL-C and triacylglycerols equally with no effect on VLDL-C. There were no unique fat- ty acid effects of the high-fat diets on ACAT activity. We conclude that supplemental fats had differential effects on hepatic ACAT activity and LDL-C, but on- ly in pigs fed low-fat diets.