Effects of Lipoxin A4 Pretreatment on Cognitive Function of Aged Rats after Global Cerebral Ischemia Reperfusion

The aim of the present study was to investigate the effect of lipoxin A4 （LXA4） pretreatment on cognitive function of aged rats after global cerebral ischemia reperfusion, and to explore its possible mechanism. Thirty-six aged male Sprague-Dawley rats were randomly divided into three groups （n=12 each）： sham-operation group （S group）, global cerebral ischemia reperfusion group （I/R group） and LXA4-pretreatment group （L group）. The rat model of global cerebral ischemia reperfusion was established by occlusion of the bilateral common carotid artery with hypotension. The cognitive function of rats was determined by a step-down type passive avoidance test and Morris Water Maze test on the third day after reperfusion. Rats were sacrificed after Water Maze test and the pathological changes ofhippocampal CA1 region were observed and the related inflammatory mediators were determined. As compared with S group, the escape latency in I/R group was prolonged from the first day to the fifth day, while that in L group was prolonged from the first day to the third day. The retention time in I/R group and L group in the first quadrant was shortened. The reaction time, frequency of reaction mistake and frequency of escape mistake in I/R group increased, and the latent period shortened. The frequency of escape mistake in L group increased, and the damage in the hippocampal CAI region of I/R group and L group was obvious. The levels of S-10013, TNF-α, IL-1β, IL-10 and NF-κB in I/R group and L group increased. As compared with I/R group, the escape latency in L group was shortened from the first day to the fifth day, and the retention time in the first quadrant prolonged. The reaction time, frequency of reaction mistake and frequency of escape mistake in L group decreased, and the latent period prolonged. The damage in the hippocampal CA1 region of L group was alleviated as well. The levels of S-10013, TNF-α, IL-1β and NF-κB in L group decreased, and those of IL-10 increased. It can be concluded that LXA4 pretreatment can improve the cognitive function in aged rats after global cerebral ischemia reperfusion probably by inhibiting the inflammatory reaction.

Effect of Lipoxin A_4 on IL-1β Production of Monocytes and Its Possible Mechanism in Severe Preeclampsia

This study examined in vitro effect of lipoxin A 4 (LXA 4) on interleukin-1β (IL-1β) production of monocytes and its possible mechanism in severe preeclampsia (PE).Peripheral venous blood was drawn from 15 patients with severe preeclampsia (PE group) and 20 normal pregnant women (control group) to prepare monocytes which were then treated with LXA 4 at different concentrations of 0,10,100 nmol/L respectively.IL-1β level in the supernatant of monocytes was detected by enzyme linked immunoassay.The [Ca 2+ ] i of monocytes was measured by laser scanning confocal microscopy.The results showed that the IL-1β level and the [Ca 2+ ] i of monocytes in the PE group were significantly higher than those in the control group.LXA 4 significantly decreased the generation of IL-1β in a dose-dependent manner in the PE group.After treatment with 100-nmol/L LXA 4,in the PE group,the [Ca 2+ ] i concentration of monocytes was significantly reduced.It was concluded that LXA 4 may inhibit the IL-1β production of monocytes from severe preeclampsia women by inhibiting extracellular calcium influx.

Shp-2／NF-κB Pathway Mediates the Inhibition of Lipoxin A4 onIL-1β-induced Synthesis of IL-6 in Glomerular Mesangial Cells

Objective: To examine whether lipoxin A 4 (LXA 4) has an antagonistic effect on IL-1β-induced synthesis of IL-6 in glomerular mesangial cells, and to explore the molecular mechanisms of signal pathway in LXA 4 actions. Methods: The glomerular mesangial cells of rat were cultured and treated with IL-1β, with or without preincubation with LXA 4 at different concentrations. The amount of IL-6 in the supernatant of cells was analyzed by enzyme-linked immunosorbent assay(ELISA). The expressions of mRNA of IL-6 were determined by RT-PCR. The expressions of Src homology 2(SH 2) containing protein-tyrosine phosphatase 2(Shp-2) were assessed by immunoprecipitation and immunoblotting. Activities of DNA-binding of nuclear factor-kappa B(NF-κB) were measured by electrophoretic mobility shift assay(EMSA). Results: IL-1β-stimulated secretion of protein and expression of mRNA of IL-6 in mesangial cells were inhibited by LXA 4 in a dose-dependent manner. LXA 4 antagonizes the phosphorylation of Shp-2 and activities of NF-κB induced by IL-1β. Conclusion: LXA 4 antagonists IL-1β-induced synthesis of IL-6 in glomerular mesangial cells through the mechanism of Shp-2/NF-κB pathway-dependent signal transduction.

Molecular mechanism of the inhibition effect of Lipoxin A4 on corneal dissolving pathology process

AIM:Excessive dissolve of corneal tissue induced by MMPs which were activated by cytokins and chemokines will lead to corneal ulcer. The molecular mechanism of Lipoxin A4 (LXA4) on corneal collagen degradation in three dimensions was investigated. ·METHODS:Rabbit corneal fibroblasts were harvested and suspended in serum -free MEM. Type I collagen, DMEM, collagen reconstitution buffer and corneal fibroblast suspension were mixed on ice. The resultant mixture solidified in an incubator, after which test reagents and plasminogen was overlaid and the cultures were returned to the incubator. The supernatants from collagen gel incubations were collected and the amount of hydroxyproline in the hydrolysate was measured. Immunoblot analysis of MMP-1,-3 and TMMP-1,-2 was performed. MMP-2, -9 was detected by the method of Gelatin zymography. Cytotoxicity assay was measured. RESULTS:LXA4 inhibited corneal collagen degradation in a dose and time manner. LXA4 inhibited the IL -1β induced increases in the pro-MMP-1, -2, -3, -9 and active MMP -1,-2,-3,-9 in a concentration dependent manner. LXA4 also inhibited the IL-1β induced increases in TIMP-1, -2. CONCLUSION:As a potent anti-inflammation reagent, LXA4 can inhibit corneal collagen degradation induced by IL-1β in corneal fibroblasts thus inhibiting corneal dissolving pathology process.

Lipoxin A_4 induces apoptosis of renal interstitial fibroblasts via calcium-dependent up-regulation of calpain 10 and Smac expressions

Objective: To examine whether lipoxin A 4 (LXA 4) induces apoptosis of renal interstitial fibroblasts and explore the mechanisms of signal pathway of LXA 4. Methods: Rat renal inte rstitial fibroblasts (NRK-49F cells) were exposed to LXA 4 at different concen trations. Prior to the experiment, the cells were transfected with Smac or calpa in 10 antisense oligodeoxynucleotide (ODN), or treated with calcium channel inhi bitor SK&F96365. Apoptosis of cells was recognized by double staining using acri dine orange and ethidium bromide, observed in laser scanning confocal microscope , and counted by a flow cytometer. Caspase-3 activities were measured by colori metric assay. The levels of free cytosolic calcium ( i) were anal yzed in fura-2-loaded cells by laser scanning confocal microscopy. Expression of calpain 10 mRNA was determined by RT-PCR. Expres sions of Smac protein and threonine phosphorylated Akt 1 proteins at 308 site w ere determined by a Western blotting analysis. Activity of signal transducers an d activators of transcription-3 (STAT 3) was determined by electrophoretic mob ility shift assay. Results: LXA 4 at the concentrations of 0.1 and 1 μmol/L induced 9.83% and 33.82% apoptosis of NRK-49F cel ls respectively, reduced at S and G 2-M phase and increased the cells at G 0 -G 1 phase in a dose-dependent manner. Treatment of the cells with LXA 4 inc reased the expressions of calpain 10 and Smac, the levels of i a nd activity of caspase-3. It also down-regulated the DNA-binding activity of STAT 3 and expression of threonine phosphorylated Akt 1. Transfection of the c ells with calpain 10 antisense ODN inhibited the LXA 4-induced apoptosis, acti vity of caspase-3 and expression of calpain 10, and ameliorated the decreased a ctivity of STAT 3. Transfection of the cells with Smac antisense ODN inhibited the LXA 4-induced apoptosis, activity of caspase-3 and expression of Smac. Pr etreatment of the cells with SK & F96365 inhibited the LXA 4-induced apoptosis , levels of i, expression of calpain 10 and Smac. Conclu sion: LXA 4 at high concentration induced apoptosis of rat renal inters titial fibroblasts via i-dependent up-regulation of calpain 10 and Smac expressions.

PI3-K/PKB/NF-κB and p42/44 MAPK pathway mediates inhibition of lipoxin A_4 on CTGF-induced production of RANTES in mesangial cells

In order to investigate the regulatory role of connective tissue growth factor （CTGF） on production of RANTES （regulated on activation, normal T cell expressed and secreted） in rat glomerular mesangial cells, and the modulatory effect of lipoxin A4 （ LXA4 ） on action of CTGF, and to explore the mechanisms of action of CTGF and LXA4, cultured rat mesangial cells were treated with CTGF, with or without preincubation with LXA4. Expression of mRNA was analyzed by RT-PCR. Protein of RANTES in the supematants was determined by ELISA. Monocyte transmigration was assessed by in vitro chemotaxis assay. Expression of p42/44 mitogen-activated protein kinase （MAPK）, phosphoinositide 3-kinase （ PI3- K） and protein kinase B （PKB） was assessed by Western blotting. DNA-binding activity of nuclear factor-roB （NF-kB） was determined by electrophoretic mobility shift assay （EMSA）. To observe whether transfection of LXA4 receptor homologue gene （LRHg） into mesangial cells intensified these modulatory effects of LXA4, mesangial cells were transfected with pcDNA3.1/LRHG vector. The results showed that CTGF enhanced the mRNA expression and protein release of RANTES, and the expression of phospho （P）-p42/44 MAPK, P-PI3-K, P-PKB and NF-kB. P-p42/44 MAPK blockade inhibited the CTgF-induced expression of P-p42/44 MAPK and partially decreased the level of RANTES in supematants. P- PI3-K blockade downregulated the CTGF-stimulated expression of P-PI3-K, P-PKB and NF-kB, and partially decreased the release of RANTES. NF-kB blockade abrogated the CTGF-activated NF-kB and partially decreased the secretion of RANTES. LXA4 dose-dependently inhibited the CTGF-stimulated above action. Transfection of LRHG into mesangial cells intensified these inhibitory effects of LXA4 on CTGFinduced release of RANTES and expression of the P-p42/44 MAPK. In conclusion, LXA4 inhibits CTGFinduced production of RANTES via PI3-K/PKB/NF-kB and p42/44 MAPK-dependent signal pathway, which is mediated by LRHG in rat mesangial cells.

Jak_1/STAT_3 pathway mediates the inhibition of lipoxin A_4 on TNF-α-induced DNA synthesis of glomerular mesangial cells in rats

Objective： To examine whether lipoxin A4 （LXA4） has an inhibitory effect on tumor necrosis factor-α（TNF-α-induced DNA synthesis of glomerular mesangial cells of rat, and explore the molecular mechanisms of LXA4 action. Methods： Glomerular mesangial cells of rat were cultured and preincubated with LXA4 at different concentrations, and then treated with TNF-α（ 10 ng/ml）. DNA synthesis was assessed by the incorporation of [^3H]-thymidine in mesangial cells. Expression of cyclin E protein was determined by Western blotting analysis. Activities of signal transducers and activators of transcription-3 （STAT3） were analyzed by electrophoretic mobility shift assay （EMSA）. Results： TNF-α-stimulated DNA synthesis of mesangial cells, upregulafion of cyclin E protein and STAT3 activities were inhibited by LXA4 in a dose-dependent manner. Conclusion： TNF-α-induced DNA synthesis of mesangial cells can be inhibited by TXA4 probably through the mechanism of Jak1/STAT3 pathway-dependent signal transduction.

Effect of lipoxin receptor agonist BML-111 on the NLRP3 inflammasome after traumatic brain injury in rats

Objective:To investigate the effect of lipoxin receptor agonist BML-111 on the NLRP3 inflammasome after traumatic brain injury in rats.Methods:Sixty male Sprague-Dawley rats,weighing 280~340 g,were randomly divided into 4 groups(n=15):the sham operation group(group Sham),the traumatic brain injury group(group TBI),the BML-111 treatment group(group BML-111),and the BOC-2 treatment group(group BOC-2).The TBI model was prepared by craniocerebral collision,while the rats in group Sham underwent only craniotomy without collision.Acute traumatic brain injury model was prepared in group TBI,BML-111 and BOC-2.The rats in group BOC-2 were intraperitoneally injected with 50μg/kg of BOC-230 min prior to trauma.Then the rats in group BOC-2 and BML-111 were injected intraperitoneally with 1 mg/kg of BML-111 immediately and 24 hours after trauma.The neurological severity scores(NSS)were evaluated at 3 and 7 days after brain trauma.The protein expression levels of NLRP3,Caspase-1-p20 and active Caspase-3 were determined by Western blot.The content of IL-1βand IL-18 was detected by ELISA assays.The apoptotic cells were analyzed by the TUNEL method.Results:Compared with group Sham,the brain water content and NSS scores in group TBI were increased,and the protein levels of NLRP3,Caspase-1-p20,activated Caspase-3,IL-1βand IL-18 as well as TUNEL-positive cells in the cortex were elevated significantly(P<0.05);compared with group TBI,the brain water content and NSS scores in group BML-111 were reduced,and the protein levels of NLRP3,Caspase-1-p20,activated Caspase-3,IL-1βand IL-18 as well as TUNEL-positive cells in the cortex were decreased(P<0.05);Compared with group BML-111,the brain water content and NSS scores in group BOC-2 were increased,and the protein levels of NLRP3,Caspase-1-p20,activated Caspase-3,IL-1βand IL-18 as well as TUNEL-positive cells in the cortex were up-regulated(P<0.05).Conclusions:The lipoxin receptor agonist BML-111 might attenuate traumatic brain injury in rats by inhibiting NLRP3 inflammasome activation.

MyD88/PI3-K/NF-κB pathway mediates the antagonism of lipoxin A_4 on LPS-induced synthesis of interleukins in endothelial cells

In order to investigate whether lipoxin A4 （LXA4） has an antagonistic effect on lipopolysaccharide （LPS）-induced synthesis of interleukin （IL）-β3, IL-6 and IL-8 in rat pulmonary microvascular endothelial cells （PMVEC）, and to explore the molecular mechanisms of signal pathway in LXA4 actions, cultured PMVEC were treated with LPS, with or without preincubation with LXA4. Proteins of IL-β3, IL-6 and IL-8 in supernatant were analyzed by enzyme-linked immunosorbent assay （ELISA）. Expressions of mRNA of IL-β3, IL-6 and IL-8 were determined by RT-PCR. Expressions of phosphorylation of phosphoinositide 3-kinase （PI3-K） and myeloid differentiation factor 88 （MyD88） were analyzed by Western blot. Activities of DNA-binding of nuclear factor-kappa B （NF-κB） and activator protein-1 （AP-1） were measured by electrophoretic mobility shift assay （EMSA）. The results showed that LPS induced production of IL-β3, IL-6 and IL-8 in rat PMVEC via MyD88/PI3-K/NF-κB and AP-1 pathway-dependent signal transduction. LPS-stimulated expression of PI3-K, activities of NF-κB and AP-1, secretion of protein and expression of mRNA of IL-β3, IL-6 and IL-8 but not MyD88 expression in PMVEC were inhibited by LXA4 in a dose-dependent manner. In conclusion, LXA4 inhibits synthesis of IL-β3, IL-6 and IL-8 by down-regulation of PI3-K/NF-κB and AP-1 signal pathway in PMVEC.

LXA4、SAA、ECP水平预测咳嗽变异性哮喘患儿预后的价值

目的探讨咳嗽变异性哮喘(CVA)患儿血清脂氧素A4(LXA4)、淀粉样蛋白A(SAA)、嗜酸性细胞阳离子蛋白(ECP)水平预测咳嗽变异性哮喘患儿预后的价值,以期为临床治疗提供参考。方法本研究选取2020年1月—2023年10月在延安市人民医院就诊的114例CVA患儿为观察组;选取同期健康体检82例儿童为对照组。比较2组研究对象LXA4、SAA、ECP水平及呼气峰值流速(PEF)、呼出气一氧化氮(FeNO)。利用Pearson相关分析患儿LXA4、SAA、ECP水平与PEF、FeNO相关性。依据患儿预后将患儿分为预后良好组(n=80)与预后不良组(n=34)。比较2组患儿LXA4、SAA、ECP与PEF、FeNO水平。绘制受试者工作特征(ROC)曲线分析血清LXA4、SAA、ECP水平对患儿预后的预测效能。结果观察组患儿LXA4、SAA、ECP及FeNO水平高于对照组研究对象,PEF低于对照组研究对象,差异均有统计学意义(P<0.05)。Pearson相关分析结果显示:CVA患儿血清LXA4、SAA、ECP水平与PEF呈负相关,与FeNO呈正相关(P<0.05)。预后良好组患儿LXA4、SAA、ECP及FeNO水平均低于预后不良组,PEF高于预后不良组(P<0.05)。绘制LXA4、SAA、ECP水平预测CVA患儿预后的ROC曲线,计算曲线下面积(AUC),结果显示:LXA4、SAA、ECP水平对CVA患儿预后具有较高的预测价值(AUC>0.7)。结论CVA患儿存在血清LXA4、SAA、ECP及FeNO水平增高,PEF下降的现象。血清LXA4、SAA、ECP水平对患儿预后具有较高的预测价值,可评估患儿的疾病严重程度。

脂氧素A4对Ⅱ型肺泡上皮细胞-间质转化的抑制作用及其机制

目的 探讨脂氧素A4(lipoxin A4, LXA4)对Ⅱ型肺泡上皮细胞(alveolar epithelial typeⅡcell, ATⅡ)间质转化(epithelial-mesenchymal transition, EMT)的影响及可能机制。方法 将A549细胞分为对照组、转化生长因子β1(transforming growth factor, TGF-β1)组、空质粒+TGF-β1组、pcDNA3.1-Nrf2+TGF-β1组及LXA4+TGF-β1组。TGF-β1组以5 ng/mL TGF-β1干预A549细胞48 h;空质粒+TGF-β1组和pcDNA3.1-Nrf2+TGF-β1组A549细胞先分别转染空质粒或Nrf2过表达质粒,再以5 ng/mL TGF-β1干预48 h;LXA4+TGF-β1组A549细胞先用100 nmol/L LXA4预处理6 h再给予5 ng/mL TGF-β1干预48 h。光镜观察细胞形态变化,免疫印迹及免疫荧光法检测上皮标志物E钙黏蛋白(E-cadherin)、间质标志物α-平滑肌肌动蛋白(α-smooth muscle actin, α-SMA)表达;免疫印迹法检测核因子红细胞2相关因子2(nuclear factor erythroid 2-related factor 2, Nrf2)蛋白水平。结果 与对照组相比,TGF-β1组光镜下可见部分A549细胞形态从鹅卵石状变成细长不规则状,呈间质性改变,E-cadherin表达减少(P<0.05)、α-SMA表达增多(P<0.01),Nrf2蛋白水平下调(P<0.05)。与TGF-β1组相比,pcDNA3.1-Nrf2+TGF-β1组A549细胞E-cadherin表达增多(P<0.05)、α-SMA表达减少(P<0.01);LXA4+TGF-β1组A549细胞E-cadherin上调、α-SMA下调以及Nrf2蛋白水平增多(P<0.05)。结论 LXA4可抑制A549细胞发生EMT,其机制与上调Nrf2表达相关。

特发性血小板减少性紫癜患儿血清LXA4、ADAMTS-1水平及其在预后评估中的价值

目的 探讨特发性血小板减少性紫癜(ITP)患儿血清脂氧素A4(LXA4)及含凝血酶敏感素1型基序的解聚素样金属蛋白酶(ADAMTS-1)水平以及二者在ITP预后评估中的价值。方法 将2020年8月至2022年8月于该院确诊为ITP的112例患儿纳入研究作为ITP组。另选取同期于该院体检的106例健康志愿者作为对照组。采用酶联免疫吸附法检测受检者血清LXA4、ADAMTS-1水平。采用Pearson相关分析患儿血清LXA4、ADAMTS-1水平的相关性。对不同病情及预后患儿的血清LXA4与ADAMTS-1水平进行比较。采用受试者工作特征(ROC)曲线分析血清LXA4与ADAMTS-1对ITP预后不良的预测价值。采用Logistic回归分析影响ITP患儿预后的因素。结果 与对照组相比,ITP组血清LXA4与ADAMTS-1的水平均升高(t=16.921、17.360,P<0.05)。Pearson相关分析显示,血清LXA4与ADAMTS-1呈正相关性(r=0.577,P<0.05)。与轻度组相比,中度组与重度组血清LXA4与ADAMTS-1表达水平较高(P<0.05);与中度组比较,重度组血清LXA4与ADAMTS-1水平较高(P<0.05)。预后不良组血清LXA4与ADAMTS-1水平均高于预后良好组(t=7.903、11.480,P<0.05);血清LXA4、ADAMTS-1单独及联合检测用于ITP预后不良预测的曲线下面积(AUC)分别为0.695、0.816、0.882,二者联合预测ITP预后的AUC大于LXA4单独预测的AUC(Z=3.363,P<0.05)和ADAMTS-1单独预测的AUC(Z=2.534,P<0.05)。Logistic回归分析显示,LXA4与ADAMTS-1是ITP预后不良的危险因素(P<0.05)。结论 ITP患儿血清LXA4与ADAMTS-1水平升高,联合检测LXA4、ADAMTS-1水平有助于评估患儿预后。

脂氧素A_(4)在运动改善骨关节炎中的作用与机制研究

骨关节炎(osteoarthritis,OA)是一种慢性关节疾病,主要表现为软骨退行性改变、滑膜炎症及关节功能衰退。在其病理发展中,炎症反应及炎症因子的过度释放起关键作用。脂氧素A_(4)(lipoxin A_(4),LXA_(4)),是一种具有显著抗炎特性的脂质调节因子,在OA的发病中展现出内源性抗炎和免疫调节效应。近期研究揭示,作为OA的非药物治疗策略,运动能显著调控LXA_(4)水平及炎症反应。LXA_(4)能抑制NF-κB和p38-MAPK信号通路,缓解OA相关炎症和疼痛。运动能激活12-氧脂合酶(12-LOX)和氧化脂质途径,增强LXA_(4)合成,并进一步通过与滑膜成纤维细胞、巨噬细胞及中性粒细胞的交互作用,降低炎症因子水平。运动的强度和频率也对LXA_(4)水平和OA治疗效果产生影响。中至高强度运动在提升LXA_(4)水平和抑制炎症因子方面表现尤为显著,但高强度运动可能对软骨产生负面效应。目前适宜的运动模式为每次20~30 min,每日2~3次,间隔4 h,此模式在降低软骨分解相关酶及优化软骨组织结构方面展现出卓越效果。

Lipoxin A_4 negatively regulates lipopolysaccharide-induced differentiation of RAW264.7 murine macrophages into dendritic-like cells

Background Lipoxins （LXs）, endogenous anti-inflammatory and pro-resolving eicosanoids generated during various inflammatory conditions, have novel immunomodulatory properties. Because dendritic cells （DCs） play crucial roles in the initiation and maintenance of immune response, we determined whether LXs could modulate the maturation process of DCs and investigated the effects of lipoxin A4 （LXA4） on lipopolysaccharide （LPS）-induced differentiation of RAW264.7 cells into dendritic-like cells. Methods RAW264.7 cells were cultured in vitro with 1 pg/ml LPS in the absence or presence of LXA4 for 24 hours, and cellular surface markers （MHC-II, CD80 （B7-1）, CD86（B7-2）） were measured by flow cytometry （FCM）. Mixed lymphocyte reaction was performed to evaluate the allostimulatory activity. Cytoplastic IKB degradation and nuclear factor kappa B （NF-KB） translocation were detected by Western blotting. Luciferase reporter plasmid was transiently transfected into RAW264.7 cells, and luciferase activity was determined to measure the transcriptional activity of NF-KB. Results LXA4 reduced the ratio of LPS-treated RAW264.7 cells to DCs with morphological characteristics and inhibited the expression of MHC I1. LPS-induced up-regulation of CD86 was moderately suppressed by LXA4 but no obvious change of CD80 was observed. Moreover, LXA4 weakened the aUostimulatory activity of LPS-treated RAW264.7 cells. These alterations of LPS＋LXA4-treated cells were associated with a marked inhibition of IKB degradation, NF-KB translocation and then the transcriptional activity of NF-KB. Conclusions LXA4 negatively regulates LPS-induced differentiation of RAW264.7 cells into dendritic-like cells.This activity reveals an undescribed mechanism of LXA4 to prevent excessive and sustained immune reaction by regulating maturation of DCs.

脂氧素A4及其类似物与巨噬细胞的相互作用促进炎症反应消退的研究进展

脂氧素A4(lipoxin A4,LXA4)是花生四烯酸的产物之一,是内源性脂肪酸产生的天然促分解代谢分子,被誉为炎症因子的“刹车信号”,有强大的抗炎作用,但其代谢迅速,而LXA4类似物相对更稳定,也具有一定的抗炎效果。对抗炎症的明星细胞——巨噬细胞,是天然免疫屏障的重要组分,和LXA4一样,在炎症的消退中有着不可替代的作用。LXA4及其类似物与巨噬细胞在抑制炎症反应的过程中有着千丝万缕的联系,本文就两者在炎症反应中的相互作用进行综述,为多种炎症相关疾病的治疗提供新思路。

Lipoxin A4 Ameliorates Lipopolysaccharide-lnduced A549 Cell Injury through Upregulation of N-myc Downstream-Regulated Gene-1

Background： Lipoxin A4 （LXA4） can alleviate lipopolysaccharide （LPS）-induced acute lung injury （ALl） and acute respiratory distress syndrome through promoting epithelial sodium channel （ENaC） expression in lung epithelial cells. However, how LXA4 promote ENaC expression is still largely elusive. The present study aimed to explore genes and signaling pathway involved in regulating ENaC expression induced by LXA4. Methods： A549 cells were incubated with LPS and LXA4, or in combination, and analyzed by quantitative real-time polymerase chain reaction （qRT-PCR） of ENaC-α/γ. Candidate genes affected by LXA4 were explored by transcriptome sequencing ofA549 cells. The critical candidate gene was validated by qRT-PCR and Western blot analysis ofA549 cells treated with LPS and LXA4 at different concentrations and time intervals. LXA4 receptor （ALX） inhibitor BOC-2 was used to test induction of candidate gene by LXA4. Candidate gene siRNA was adopted to analyze its influence on A549 viability and ENaC-α expression. Phosphoinositide 3-kinase （PI3K） inhibitor LY294002 was utilized to probe whether the PI3K signaling pathway was involved in LXA4 induction of candidate gene expression. Results： The A549 cell models of ALl were constrticted and subjected to transcriptome sequencing. Among candidate genes, N-myc downstream- regulated gent- 1 （NDRG 1 ） was validated by real-time-PCR and Western blot. NDRG 1 mRNA was elevated in a dose-dependent manner of LXA4, whereas BOC-2 antagonized NDRG 1 expression induced by LXA4. NDRG I siRNA suppressed viability of LPS-treated A549 cells （treatment vs. control, 0.605± 0.063 vs. 0.878 ± 0.083, P = 0.040） and ENaC-α expression （treatment vs. control, 0.458 ± 0.038 vs. 0.711 ± 0.035, P = 0.008）. LY294002 inhibited NDRG 1 （treatment vs. control, 0.459 ± 0.023 vs. 0.726 ± 0.020, P 0.001 ） and ENaC-α （treatment vs. control, 0.236 ± 0.021 vs. 0.814 ±0.025, P 〈 0.001 ） expressions and serum- and glucocorticoid-inducible kinase I phosphorylation （treatment vs. control, 0.442± 0.024 vs. 1.046 ± 0.082, P = 0.002）, indicating the PI3K signaling pathway was involved in regulating NDRG 1 expression induced by LXA4. Conclusion： Our research uncovered a critical role of NDRG1 in LXA4 alleviation of LPS-induced A549 cell injury through mediating PI3K signaling to restore ENaC expression.

过敏性鼻炎患者血清LXA4、Gal-3水平与病情进展的关系

目的探究过敏性鼻炎(AR)患者血清脂氧素A4(LXA4)、半乳糖凝集素-3(Gal-3)水平与其病情进展的关系。方法纳入2022-07至2023-10解放军总医院京南医疗区门诊就诊的113例AR患者为AR组,根据世界卫生组织的分级标准分为轻度组48例,中重度组65例。同时选取110例健康志愿者为对照组。血清LXA4、Gal-3水平采用酶联免疫吸附试剂盒测定,收集AR患者一般资料。变量间的相关分析采用Spearman相关检验。使用受试者工作特征(ROC)曲线来评估血清LXA4、Gal-3水平区分AR不同严重程度的能力。采用Logistic回归分析AR疾病严重程度的影响因素。结果与对照组相比,AR组血清LXA4、Gal-3水平明显升高(P<0.05)。中重度组视觉模拟量表评分(VAS)、鼻部症状评分(TNSS)、血清LXA4、Gal-3水平显著高于轻度组(P<0.05)。Spearman相关分析显示,AR患者血清LXA4、Gal-3水平与VAS、TNSS评分均呈正相关(P<0.05)。血清LXA4、Gal-3及两者联合诊断中重度AR发生的AUC分别为0.829、0.812、0.912,显著高于单独检测(Z联合-LXA4=3.076、Z联合-Gal-3=2.940,P<0.05)。血清LXA4、Gal-3水平是影响中重度AR发生的独立危险因素(P<0.05)。结论血清LXA4、Gal-3在AR患者中水平升高,且与其病情进展关系密切。

支气管哮喘患者血清CCR5、LXA4表达水平及其与免疫功能失调、气道重塑的相关性分析

目的分析支气管哮喘患者血清细胞趋化因子受体5(CCR5)、脂氧素A4(LXA4)表达水平及其与免疫功能失调、气道重塑的相关性。方法采用回顾性研究,根据疾病严重程度将2021年1月至2023年5月北京市大兴区人民医院收治的80例支气管哮喘患者分为轻中度组(n=60)和重度组(n=20),另选取同期入院体检的50名健康体检者作为对照组。检测各组血清CCR5、LXA4和免疫功能指标(CD3^(+)、CD4^(+)、CD8^(+)、CD4^(+)/CD8^(+)),并采用CT仪检查其右肺上叶尖段的气道重塑指标[气道管腔面积(LA)、气道管壁面积(WA)和气道总面积(TA)]。根据双变量Spearman相关性检验分析血清CCR5、LX4A与免疫功能失调和气道重塑的相关性,并建立多因素Logistic模型分析影响支气管哮喘患者血清CCR5、LX4A的独立危险因素。结果轻中度组、重度组患者血清CCR5、LX4A水平均高于对照组,重度组患者血清CCR5高于轻中度组患者,LXA4水平低于轻中度组患者,差异均有统计学意义(P<0.05)。轻中度组、重度组患者血清CD3^(+)、CD4^(+)、CD4^(+)/CD8^(+)水平均低于对照组,CD8^(+)水平高于对照组患者,且重度组患者CD3^(+)、CD4^(+)、CD4^(+)/CD8^(+)水平均低于轻中度组患者,CD8^(+)水平高于轻中度组患者,差异均有统计学意义(P<0.05)。轻中度组、重度组患者右肺上叶尖段LA、WA、TA水平均低于对照组,且重度组患者右肺上叶尖段LA、WA、TA水平均低于轻中度组,差异均有统计学意义(P<0.05)。血清CCR5、LX4A与CD3^(+)、CD4^(+)、CD4^(+)/CD8^(+)呈负相关性(P<0.05),与CD8^(+)、LA、WA、TA呈正相关性(P<0.05)。多因素Logistic回归分析结果显示,疾病严重程度、CD3^(+)、CD4^(+)、CD8^(+)、CD4^(+)/CD8^(+)、LA、WA、TA均是导致支气管哮喘患者血清CCR5、LX4A升高的独立危险因素(P<0.05)。结论血清CCR5、LX4A与支气管哮喘疾病严重程度、免疫功能失调和气道重塑密切相关。

外周血CD8^(+)、PTX3、LXA4水平联合检测在变应性鼻炎严重程度鉴别中的诊断效能

目的:分析外周血CD8^(+)、正五聚蛋白3(PTX3)和脂氧素A4(LXA4)水平联合检测在变应性鼻炎严重程度鉴别中的诊断效能。方法:选取2022年8月至2023年8月该院收治的100例变应性鼻炎患者,设为观察组,另选取同期100名健康体检者,设为对照组。比较两组CD8^(+)、PTX3、LXA4水平,并将变应性鼻炎患者按不同严重程度分为轻度患者、中-重度患者,比较轻度与中-重度患者外周血CD8^(+)、PTX3、LXA4水平;分析外周血CD8^(+)、PTX3、LXA4水平单项及联合检测在变应性鼻炎轻度与中-重度鉴别中的诊断效能。结果:观察组外周血CD8^(+)、PTX3、LXA4水平均高于对照组,差异有统计学意义(P<0.05);中-重度患者外周血CD8^(+)、PTX3、LXA4水平均高于轻度患者,差异有统计学意义(P<0.05);受试者工作特征(ROC)曲线分析结果显示,外周血CD8^(+)、PTX3、LXA4水平单项及联合检测诊断变应性鼻炎中-重度的曲线下面积分别为0.675、0.664、0.673、0.936,联合检测诊断效能最高。结论:外周血CD8^(+)、PTX3、LXA4水平联合检测在变应性鼻炎轻度与中-重度鉴别中的诊断效能高于三者单项检测。

Lipoxin A_4通过调节肿瘤相关巨噬细胞对肝癌细胞株HepG2 microRNA表达谱的影响

肿瘤与炎症密切相关,作者以往已证实内源性促炎症缓解介质脂氧素A4(Lipoxin A4,LXA4)能在整体和细胞水平发挥抗肝癌细胞增殖和转移的作用。为进一步探讨LXA4通过调节肿瘤相关巨噬细胞对肝癌细胞株HepG2 microRNAs(miRNAs)表达谱的影响,该文首先提取经脂多糖(LPS)或LPS+LXA4作用24 h的人巨噬细胞株U937培养上清液,分别称为ACM或LCM,以模拟肿瘤的炎症微环境,并用此上清液刺激HepG2细胞,24 h后提取细胞总RNA,采用microRNA芯片miRCURYTM LNA Array(V16.0)检测,计算各样本中的miRNAs标准值及比值。以两组间Hy3荧光标记信号强度的比值≤0.5或≥2为标准判定差异表达miRNA。Real-time PCR检测hsa-miR-623的相对含量以验证基因芯片的结果。结果发现,与对照组细胞相比,经过ACM作用24 h的HepG2细胞有35个miRNAs上调、130个miRNAs下调。LCM组与ACM组相比,HepG2细胞有185个miRNAs上调、71个miRNAs下调。Real-time PCR检测的结果证实,hsa-miR-623的变化与基因芯片趋势一致。综上所述,LXA4能通过肿瘤相关巨噬细胞而间接发挥其调节HepG2细胞miRNAs表达谱的作用。