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Objective:To investigate the correlation between serum levels of heme oxygenase-1 (HO-1) and lipoxin A4 (LXA4) and diabetic nephropathy, and to analyze the value of HO-1 and LXA4 in the diagnosis of diabetic nephropathy.Methods:A prospective cohort study was conducted in 185 patients with type 2 diabetes admitted to the Department of Endocrinology, Yan'an Hospital Affiliated to Kunming Medical University from January 2016 to January 2020. There were 96 cases with diabetic nephropathy (nephropathy group) and 89 cases without diabetic nephropathy (non nephropathy group). According to the stage of chronic kidney disease,the nephrotic group was divided into three subgroups: stage 1-2 group (31 cases), stage 3-4 group (40 cases) and stage 5 group (25 cases). Another 82 healthy volunteers were selected as the control group.Serum HO-1, LXA4, oxidative stress,inflammatory factors, glucose metabolism and renal function were detected. Pearson analysis of HO-1, LXA4 and oxidative stress, inflammatory factors, glucose metabolism and renal function index correlation, binary logistic regression analysis of diabetic nephropathy factors.Results:The serum HO-1 ((0.60 ± 0.20) μg/L) and LXA4 levels ((435.12 ± 22.42) ng/L) in nephrotic group were lower than those in non nephrotic ((0.72 ± 0.23) μg/L, (498.21 ± 29.48) ng/L)( t=29.351, 24.135, all P<0.05). The serum HO-1 and LXA4 levels in the 5 stage group were lower than those in the 3-4 stage and 1-2 stage group (all P<0.05). The serum HO-1 and LXA4 levels in the 3-4 stage group were lower than those in the 1-2 stage group (all P<0.05). Pearson correlation analysis showed that HO-1 was positively correlated with total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and estimated glomerular filtration rate (EGFR) ( r=0.516, 0.602, 0.617; all P<0.05), and was positively correlated with malondialdehyde (MDA) and homeostasis model insulin resistance (homeostasis model insulin resistance) Model assessment insulin resistance (HOMA-IR), urinary albumin creatinine ratio (UACR) LXA4 was negatively correlated with T-AOC, SOD and EGFR ( r=-0.559, 0.597, 0.637; all P<0.05), and positively correlated with MDA, IL-6, TGF-β1, HOMA-IR and UACR There was a negative correlation ( r=-0.498, -0.623, -0.725; all P<0.05). Binary logistic regression analysis showed that malondialdehyde ( OR=1.587, 95% CI 1.402-1.603, P=0.016), TGF-β1 ( OR=1.679, 95% CI 1.642-1.739, P=0.012), HOMA-IR ( OR=1.699、95% CI 1.534-1.739, P=0.009) were risk factors of diabetic nephropathy (all P<0.05). HO-1 ( OR=0.506, 95% CI 0.423-0.653, P<0.001) and LXA4 ( OR=0.492, 95% CI 0.409-0.535, P<0.001) were protective factors for DN ( P<0.001). After adjusting for MDA, TGF-β1 and HOMA-IR, HO-1 ( OR=0.485, 95% CI:0.402-0.564, P<0.001) and LXA4 ( OR=0.416, 95% CI:0.386-0.475, P<0.001) were still associated with DN. ROC analysis showed that the area under curve (AUC) of HO-1 and LXA4 were 0.820 (95% CI:0.760-0.880, P<0.001) and 0.763 (95% CI:0.691-0.836, P<0.001), respectively. The sensitivity and specificity were 71.88%, 80.90%, 75.00% and 84.27%, respectively. Conclusion:The decrease of serum LXA4 and HO-1 levels is closely related to diabetic nephropathy, which can be used as a biological indicator for the diagnosis of diabetic nephropathy.
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Objective@#To explore the role of toll-like receptor 4 (TLR4)/NF-κB signaling pathway in acute necrotizing pancreatitis (ANP)-associated lung injury and the intervention of lipoxin A4 (LXA4) analogue.@*Methods@#Forty-five Sprague-Dawley rats were randomly(random number)divided into the sham operation group, experimental group, and intervention group, each group containing 15 rats. ANP animal models were prepared by injecting sodium taurocholate into biliopancreatic tube in the experimental group. No sodium taurocholate was injected into biliopancreatic duct in the sham operation group. After the preparation of ANP animal models in the intervention group, LXA4 was injected through the tail vein. Rats in each group were randomly divided into 3 subgroups (n=5 each subgroup). The serum amylase, TNF- α, IL-1β, IL-6 and endotoxin levels were detected 6, 12 and 24 h after the operation. The lung injury scores were assessed and the lung wet/dry weight ratio was calculated. The expressions of TLR4 and NF-κB p65 in lung tissues were detected by Western blot.@*Results@#Serum levels of amylase, TNF-α, IL-1β, IL-6 and endotoxin in the experimental and intervention groups were significantly higher than those in the sham operation group, while the levels of the above indicators in the intervention group was significantly lower than those in the experimental group, and the differences were statistically significant (P<0.05). Postoperative lung injury scores and lung wet/dry weight ratio in the experimental group were significantly higher than those in the sham operation group, and the differences were statistically significant (P<0.05). Lung injury scores in the intervention group 6 h after operation had no significant difference compared with those in the sham operation group (P>0.05), while lung wet/dry weight ratio in the intervention group 6 h after operation, and lung injury scores and lung wet/dry weight ratio in the intervention group 12 h or 24 h respectively after operation were significantly higher than those in the sham operation group, with statistically significant differences (P<0.05). Postoperative lung injury scores and lung wet/dry weight ratio in the intervention group were significantly lower than those in the experimental group, and the differences were statistically significant (P<0.05). The expressions of TLR4 and p65 in the lung tissues of the experimental and intervention groups were significantly higher than those of the sham operation group, and the expressions of TLR4 and p65 in the lung tissues of the intervention group were significantly lower than those of the experimental group, with statistically significant differences (P<0.05).@*Conclusions@#LXA4 can reduce the severity of acute necrotizing pancreatitis-associated lung injury, and its mechanism is related to reducing the stimulation of endotoxin, thus inhibiting TLR4 signaling pathway and the activation of p65 to down-regulate the level of pro-inflammatory cytokines.
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Objective To explore the role of toll-like receptor 4 (TLR4)/NF-κB signaling pathway in acute necrotizing pancreatitis (ANP)-associated lung injury and the intervention of lipoxin A4 (LXA4) analogue.Methods Forty-five Sprague-Dawley rats were randomly(random number)divided into the sham operation group,experimental group,and intervention group,each group containing 15 rats.ANP animal models were prepared by injecting sodium taurocholate into biliopancreatic tube in the experimental group.No sodium taurocholate was injected into biliopancreatic duct in the sham operation group.After the preparation of ANP animal models in the intervention group,LXA4 was injected through the tail vein.Rats in each group were randomly divided into 3 subgroups (n=5 each subgroup).The serum amylase,TNF-α,IL-1β,IL-6 and endotoxin levels were detected 6,12 and 24 h after the operation.The lung injury scores were assessed and the lung wet/dry weight ratio was calculated.The expressions of TLR4 and NF-rκB p65 in lung tissues were detected by Western blot.Results Serum levels of amylase,TNF-α,IL-1β,IL-6 and endotoxin in the experimental and intervention groups were significantly higher than those in the sham operation group,while the levels of the above indicators in the intervention group was significantly lower than those in the experimental group,and the differences were statistically significant (P＜0.05).Postoperative lung injury scores and lung wet/dry weight ratio in the experimental group were significantly higher than those in the sham operation group,and the differences were statistically significant (P＜0.05).Lung injury scores in the intervention group 6 h after operation had no significant difference compared with those in the sham operation group (P ＞ 0.05),while lung wet/dry weight ratio in the intervention group 6 h after operation,and lung injury scores and lung wet/dry weight ratio in the intervention group 12 h or 24 h respectively after operation were significantly higher than those in the sham operation group,with statistically significant differences (P＜0.05).Postoperative lung injury scores and lung wet/dry weight ratio in the intervention group were significantly lower than those in the experimental group,and the differences were statistically significant (P＜0.05).The expressions of TLR4 and p65 in the lung tissues of the experimental and intervention groups were significantly higher than those of the sham operation group,and the expressions of TLR4 and p65 in the lung tissues of the intervention group were significantly lower than those of the experimental group,with statistically significant differences (P＜0.05).Conclusions LXA4 can reduce the severity of acute necrotizing pancreatitis-associated lung injury,and its mechanism is related to reducing the stimulation of endotoxin,thus inhibiting TLR4 signaling pathway and the activation of p65 to down-regulate the level of pro-inflammatory cytokines.
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Objective Lipoxin A4 (LXA4) has been proved to have a good protective effect on spinal cord ischemia-reperfusion injury in rats, but whether autophagy is one of the protective mechanisms remains unclear. This study aims to investigate the effects of lipoxin A4 on rat spinal cord ischemia-reperfusion injury. Methods 48 rats were randomly divided into LXA4 group, ischemia-reperfusion group (SCII group) and sham group with 16 rats in each, and the models of each group were built accordingly. The rats in LXA4 group received intrathecal injection of 10μl LXA4 (300 pmol) 30 minutes after clamping the abdominal aorta. Three groups of rats were sacrificed by cervical dislocation 24 hours after reperfusion and the apoptosis-positive cells were then obtained. The spinal cord tissues of three groups of rats were stained and counted by LC3B fluorescence staining, and the expressions of LC3-II/LC3-I and GABARAP protein were detected by Western blot. Results There were few LC3B positive cells in the sham group. Compared to those in the sham group (73.40±19.42), the number of LC3B positive cells in SCII group (399.80±18.46) and LXA4 group (240.80±12.76) significantly increased (P<0.05), and the number in LXA4 group was significantly lower than that in SCII group (P<0.05). The ratio of LC3-II/LC3-I and the expression of GABARAP in SCII group and LXA4 group was significantly higher than those in sham group (P<0.05). The ratio of LC3-II/LC3-I in spinal cord tissue significantly declined compared with that of SCII group (P<0.05). Conclusion The autophagy is activated when SCII occurs, indicating that the autophagy is involved in SCII. After LXA4 is administered, autophagy is inhibited and SCII is alleviated.
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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 CA1 region of I/R group and L group was obvious.The levels of S-100β,TNF-α,IL-lβ,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-100β,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.
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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 CA1 region of I/R group and L group was obvious.The levels of S-100β,TNF-α,IL-lβ,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-100β,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.
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<p><b>Background</b>Lipoxin A4 (LXA4) can alleviate lipopolysaccharide (LPS)-induced acute lung injury (ALI) 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.</p><p><b>Methods</b>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 of A549 cells. The critical candidate gene was validated by qRT-PCR and Western blot analysis of A549 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.</p><p><b>Results</b>The A549 cell models of ALI were constructed and subjected to transcriptome sequencing. Among candidate genes, N-myc downstream-regulated gene-1 (NDRG1) was validated by real-time-PCR and Western blot. NDRG1 mRNA was elevated in a dose-dependent manner of LXA4, whereas BOC-2 antagonized NDRG1 expression induced by LXA4. NDRG1 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 NDRG1 (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 1 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 NDRG1 expression induced by LXA4.</p><p><b>Conclusion</b>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.</p>
Subject(s)
Humans , A549 Cells , Acute Lung Injury , Metabolism , Cell Cycle Proteins , Metabolism , Cell Line , Epithelial Sodium Channels , Metabolism , Intracellular Signaling Peptides and Proteins , Metabolism , Lipopolysaccharides , Pharmacology , Lipoxins , Pharmacology , Signal TransductionABSTRACT
Objective: To investigate the protective effect of human lipoxin A4 (LXA4) on N2a cell damage induced by β-amyloid protein 25-35 (Aβ25-35) and the underlying mechanism. Methods: Aβ25-35 was used to treat N2a cells to establish Alzheimer's disease (AD) cell injury model. Meanwhile, LXA4 was added to the experimental group at different concentrations (50, 100 and 200 nmol·L-1 ). MTT assay was used to detect the activity of N2a cells. The apoptosis was detected by Hoechst 33258-PI staining, the expression of P62 and TRAF6 mRNA was detected by RT-PCR, and the expression of P62 and TRAF6 protein was detected by Western blot. Results: Compared with that of the model group, the cell survival rate of LXA4 protective group (50,100 and 200 nmol·L-1 ) increased (P <0. 01) and the apoptosis of N2a cells induced by Aβ25-35 was reduced by LXA4 (100 and 200 nmol·L-1 ) . Compared with that of the model group, the expression of P62-mRNA and protein-P62 of N2a cells treated with Aβ25-35 increased (P <0. 05 or P <0. 01) and the expression of TRAF6-mRNA and protein-TRAF6 of N2a cells treated with Aβ25-35 were reduced (P <0. 05 or P <0. 01). Conclusion: LXA4 has protective effect on N2a cell damage induced by Aβ25-35 , and its mechanism may be related to the up-regulation of P62 gene and down-regulation of TRAF6 gene.
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Objective The study aimed to investigate the effect of lipoxin A4 (LXA4) on lipopolysaccharide (LPS)?induced oxidant stress in human renal tubular epithelial cells (HK2 cells) and possible underlying mecha?nisms. MethodsHK2 cells were divided into three groups: Control ,LPS and LPS+LXA4 groups. After cells were treated with indicated conditions,morphological changes were observed. The expressions of Nrf2 were detected by immunofluorescence and cells were collected for RT?PCR experiments.Results HK2 cells seemed disrupted and necrotic with the administration of LPS. However ,LXA4 could prevent cells from injury induced by LPS. LPS decreased Nrf2 expression and promoted it to translocate to cytoplasm ,while LXA4 could increase its expression and promote it to translocate to nucleus. Moreover ,LPS could decrease Nrf2 and its downstream molecule mRNA expressions,but LXA4 could reverse this effect. Conclusion Our results demonstrated that LXA4 effectively inhibit?ed HK2 cell oxidant stress via Nrf2 pathway.
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Objective To investigate the protective effects of lipoxin A4 (LXA4) on the lung epithelial cells (MLE-12) in mice with hyperoxia injury.Methods MLE-12 cells were cultured in vitro and divided into air group,air + LXA4 group,hyperoxia group and hyperoxia + LXA4 group.The receptor of LXA4 (ALX) was verified by using reverse transcription-polymerase chain reaction (RT-PCR).MLE-12 cells were exposed to hyperoxia (＞ 850 mL/L oxygen concentration) for 12 h followed by pretreatment of 1 nmol/L,10 nmol/L and 50 nmol/L LXA4 for 1 h,6 h,12 h and 24 h.Quantitative real-time PCR (qRT-PCR) was applied to analyze the heme oxygenase 1 (HO-1) expression to determine the optimal concentration and the optimal pretreatment time of LXA4.The cell morphology was observed by using inverted microscope.The survival rates and cell viability were determined by using Trypan Blue stain and cell counting kit-8 (CCK-8).The superoxide dismutase (SOD) level was determined by using hydroxylamine method.The expressions of mRNA and protein of HO-1 were measured by using qRT-PCR,western blot and immunofluorescence assay,respectively.The interleukin-6 (IL-6) and monocyte chemotactic protein 1 (MCP-1) were determined by using enzyme-linked immunosorbent assay.Results ALX was expressed in MLE-12 cells.The optimal intervention concentration and time of LXA4 was 10 nmol/L for 12 h.Compared with air group [(84 ± 5) ％,1.22 ± 0.27,(5.33 ± 1.16) kU/L],the cell survival rate,viability and SOD level of hyperoxia group [(66 ± 8) ％,0.67 ± 0.21,(2.38 ± 0.65) kU/L] decreased,and the differences were significant (t =3.98,2.55,4.86;P =0.01,0.03,0.00);compared with the hyperoxia group,the cell survival rate,viability and SOD level of hyperoxia + LXA4 group [(88 ± 5) ％,1.43 ± 0.05,(6.50 ± 0.19) kU/L] significantly increased,and the differences were significant (t =4.83,3.52,6.78;P =0.01,0.02,0.00).The HO-1 mRNA and protein expression of hyperoxia group (0.57 ± 0.03,1.31 ± 0.11) increased as compared to air group (0.13 ± 0.03,0.24 ± 0.10),and the differences were significant (t =8.00,10.10;all P =0.00);the HO-1 expression of hyperoxia + LXA4 group (0.78 ± 0.08,1.82 ± 0.09) significantly increased as compared to hyperoxia group,and the differences were significant (t =3.94,8.82,all P=0.00).The levels of MCP-1 and IL-6 of hypemxia group [(1 025.18 ±35.51) rig/L,(1 136.65 ±160.01) ng/L] significantly increased as compared to air group [(467.63 ± 13.69) ng/L,(470.03 ± 118.22) ng/L],and the differences were significant (t =16.51,7.48;all P =0.00);the MCP-1 and IL-6 of hyperoxia + LXA4 group [(640.25 ± 61.03) ng/L,(655.48 ± 88.57) ng/L] significantly decreased as compared to hyperoxia group,and thedifferences were significant (t =11.40,5.40,all P =0.00).Conclusions LXA4 can attenuate hyperoxia-induced injury in MLE-12 cells.The protective role of LXA4 in the hyperoxia-induced cell injury is related to the up-regulation of HO-1 expression and down-regulation of IL-6 and MCP-1 levels.
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Macrophage plays an important role in human innate immune system. It has powerful functions, such as recognition, phagocytosis, and bacteria and foreign body removal. Periodontitis, which is a chronic infectious disease characterized by gum inflammation and bone loss, is a major cause of tooth loss in adults. Several studies demonstrated that periodontal tissue destruction is caused by the host immune response defending against infections. As an important part of host immune response, macrophage is also involved in periodontitis pathogenesis. Recently, anti-inflammatory and proresolving activities of macrophage was discovered. Thus, the complex function of macrophage in the occurrence, development, and resolution of inflammation and its potential role in periodontitis were reviewed.
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Objective To investigate the changes and significance of the serum myeloperoxidase (MPO) and lipoxin (LXA4) in patients with coronary heart disease (CHD). Methods From December 2010 to February 2011,143 patients with CHD (CHD group) and 44 patients without CHD (control group) were selected. The serum high sensitive C-reactive protein (hs-CRP), MPO and LXA4 levels were assessed, and the ratio of MPO and LXA4 (M/L) was calculated. These indexes were compared between 2 groups. The influencing factors of MPO, LXA4 and M/L levels were analyzed by multifactor Logistic regression analysis. Results The serum levels of hs-CRP, LXA4, MPO, and M/L in CHD group were significantly higher than those in control group: 3.25 mg/L vs. 0.99 mg/L, 229.88 ng/L vs. 178.63 ng/L, 422.58 U/L vs. 186.85 U/L and (1.78 ± 0.52) U/ng vs. (1.02 ± 0.17) U/ng, and there were statistical differences (P0.05). MPO was the impact factor for the increase of LXA4 (P0.05). Stable angina, unstable angina and acute myocardial infarction were the impact factors for the elevation of M/L (P0.05). Conclusions The inflammatory response in patients with CHD is accompanied by the presence of inflammation and resolution imbalance.
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Objective To investigate the change in expressions of lipoxin A4 (LXA4) and lipoxin A4 receptor (ALX) in rats with fat embolism syndrome(FES).Metbods Sixty healthy male SD rats were assigned to control group and FES group which was subgrouped at l,6,12 and 24 h according to the random number table,with 12 rats each.Allogeneic perinephric fat (0.706 ml/kg) was injected to rat caudal veins in FES group.Instead isotonic saline in an equal volume was given to rats in control group.Lung samples were harvested from each group to detect pathological morphology,concentration of total protein and LXA4 in bronchoalveolar lavage fluid (BALF),lung weight to dry ratio (W/D),and activity of myeloperoxidase (MPO) and ALX mRNA.Additional 40 SD rats were divided into control group,FES 24-hour group,BML-1 11 + FES 24-hour group,and Boc-2 + FES 24-hour group according to the random number table,with 10 rats each.Pathology of lung tissue was observed using microscopy and expression of lung MPO mRNA was detected.Results Lung tissues in FES group were seriously injured compared with control group.Total protein concentration in BALF was (71.12 ± 11.05) μg/ml in FES 12-hour group,significantly increased compared to (29.82 ± 0.64) μg/ml in control group (P ＜ 0.05).LXA4 concentration in BALF was (2.72 ± 0.24) ng/ml in FES 24-hour group,significantly higher than (0.69 ±0.05)ng/ml in control group (P ＜ 0.05).Lung W/D value was 9.13 ±0.83 and 9.60 ±0.86 respectively in FES 6-hour and 12-hour groups,higher than 3.09 ±0.10 in control group (P ＜0.05).Activity of MPO in lung tissue was (0.74± 0.07)U/g and (0.53 ±0.08)U/g respectively in FES 6-hour and 12-hour groups,significantly higher than (0.19 ± 0.03) U/g in control group (P ＜ 0.05).Expression of ALX mRNA was 3.99 ± 1.09 in FES 24-hour group,significantly higher than 1.00 ±0.21 in control group (P ＜0.05).Expression of MPO mRNA was lower in BML-111 + FES 24-hour group (0.69-0.08) and was higher in Boc-2 + FES 24-hour group (2.05-0.14),when compared to 1.52 ±-0.07 in FES 24-hour group (P＜0.05).Conclusion LXA4 mainly involves in the resolution of inflammation in FES rats,which may be achieved at least in part by binding to ALX.
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Objective To explore the protective role of lipoxin A4 (LXA4) during early process of atherosclerosis formation in rats with juvenile metabolic syndrome (MS).Methods Rat models of juvenile MS were established with 3-week Sprague-Dawley (SD) rats fed on high-carbonhydrates and high-fat diet for 6 weeks.The other qualified ones were randomly grouped into model group,LXA4 low-dose group,LXA4 middle-dose group,and LXA4high dose group,and a control group fed with normal forage.The low,middle,high-dose groups were injected different doses of LXA4 daily,while the model group and control group were injected with the same dose of isotonic NaCl solution for 2 consecutive weeks.After 2-week medication,the visceral adipose tissue were isolated by laparotomy and heart blood collected by thoracotomy under anesthesia,followed the fixation of thoracic and abdominal aortas in the immobilized rats.The mRNA expression level of inflammation cytokines interleukin-6 (IL-6),tumor necrosis factor-α (TNF-α),C-reactive protein (CRP) in the adipose tissue were determined by semi-quantitative reverse transcription PCR (RT-PCR),respectively.Secretions of IL-6,and TNF-α in serum were determined by enzyme linked immunosorbent assay (ELISA).Immunocytochemistry was used to label endomembrane and middle-membrane of thoracic aorta,and endothelial cell layer in each group and the ratios of thickness of endomembrane and middle-membrane were compared.Results Compared with the control group,weight,body length and abdominal circumference of juvenile MS rats increased significantly (all P ＜ 0.05),and levels of fasting plasma glucose (FPG),triglyceride (TG),high density lipoprotein cholesterol (HDL-C) and insulin in models increased significantly (P ＜ 0.05).RT-PCR showed that the mRNA expressions of inflammatory cytokines IL-6,TNF-α and CRP in adipose tissue in model rats were upexpressed (all P ＜ 0.05).Compared with model rats,mRNA of IL-6,TNF-oα,and CRP in mid,high-dose rats were downexpressed (all P ＜ 0.05),mRNA of TNF-α in low-dose rat downexpressed (all P ＜ 0.05),and there were no significant differences between mRNA expressions of IL-6,CRP in low-dose and model rats according to statistics (all P ＞0.05).Compared with control group,inflammatory cytokines IL-6,TNF-α secreted in serum of model rats were increased significantly (all P ＜ 0.05),and inflammatory cytokines secreted in serum of intervention rats were decreased significantly compared with model rats (P ＜ 0.05).Pathological changes were as follows:HE staining:compared to model group,aortic tunica intima of model rats were remarkably thickened and endothelial cell layer was fragmented and incomplete,which was attenuated in each intervention group.The ratios of endomembrane and middle-membrane in rats:at the end of consecutive medication for 2 weeks,the ratios of endomembrane and middle-membrane in model rats were significantly greater than those of control group (P ＜ O.05),and the ratios of endomembrane and middle-membrane in high-dose intervention rats were significantly smaller than those of the model group (P ＜ 0.05),but still greater than control group,while there were no statistical differences between the ratios in low,middle-dose intervention rats and model rats (P ＞ 0.05).Conclusions The increasing inflammatory cytokines are involved in early process of atherosclerosis formation in rats with juvenile MS.LXA4 by reducing the expression of inflammatory factor level in adipose tissue,thereby reducing the inflammatory cytokines in serum,alleviate the damage of arterial wall.
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Objective This study aims to investigate the effect of Lipoxin A4 receptor on acute lung injury (ALI) induced by intestine ischemia-reperfusion (IIR). Methods Thirty-two 8-week old SD rats were randomly divided into four groups: sham, intestine ischemia-reperfusion (IIR), IIR + BML111 (BML-111), Boc-2 + IIR +BML111 (Boc-2). BML-111 (1 mg/kg) was given intraperitoneally at the onset of reperfusion in the BML-111 and the Boc-2 group. Boc-2 (50 μg/kg) was given intraperitoneally after anesthesia in the Boc-2 group. Rats were subjected to superior mesenteric artery occlusion consisting of 45-min ischemia and 6-h reperfusion, and the sham laparotomy was served as controls. The lung pathology was assayed by the H&E staining. Lung water content was detected using dry/wet ratio. Concentrations of TNF-α, IL-1β, and IL-6 in lung tissue were determined by ELISA. The protein expression of p38 MAPK and NF-κB of lung was assayed by western blot. Results IIR induced serious ALI, with poor lung pathology and increased lung water content, elevation of TNF-α, IL-1β, and IL-6 levels in lung, accompanied with activation of p38 MAPK/NF-κB pathway. However, BML-111 could inhibit the activation of p38 MAPK/NF-κB pathway, leading to the reductions of TNF-α, IL-1β, and IL-6 in lung and attenuation of IIR-induced ALI. Conclusion BML-111 treatment could attenuate inflammation in lung after IIR injury via inactivating the p38 MAPK/NF-κB signaling pathway.
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Objective To investigate the effects of lipoxin A4 ( LXA4 ) on inflammatory related factors induced by uric acid( UA) in human umbilical vein endothelial cells( HUVECs) . Methods HUVECs were treated with 5, 25, and 50 ng/ml LXA4 prior to exposure to 12 mg/dl UA. Tumor necrosis factor-alpha(TNF-α), interleukin ( IL)-1β, and IL-6 were analyzed with ELISA and realtime PCR. The phosphorylation levels of p38 mitogen-activated protein kinases( MAPK) and NF-κB/p65 were observed with Western blot. Results Stimulation of HUVECs with 12 mg/dl UA markedly increased TNF-α, IL-1β, and IL-6 production(P<0. 01). Pretreatment with LXA4 significantly inhibited UA-induced production of TNF-α, IL-1β, and IL-6 in a concentration dependent manner(P<0. 01). The mRNA expressions of TNF-α, IL-1β, and IL-6 in response to UA were also decreased by LXA4(P<0. 05). Western blot analysis showed that the phosphorylation levels of p38 MAPK and NF-κB/p65 were significantly raised by 12 mg/dl UA in HUVECs(P<0. 05), but attenuated significantly in the presence of 50 ng/ml LXA4. Conclusion LXA4 may inhibit the expressions of inflammatory related factors induced by UA via reducing p38 MAPK and NF-κB/p65 phosphorylation and play a role in anti-inflammation.
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Objective To investigate the effect of lipoxin A4 LXA4) on radicular pain caused by intervertebral disc herniation.Methods Non-compressive intervertebral disc herniation was induced into forty-eight adult male Sprague-Dawley rats,and they were divided into a sham group (sham operation + 10 μl normal saline),a control group (modeled + 10 μl normal saline),an LXA4 10 ng group (modeled + 10 ng LXA4) and an LXA4 100 ng group (modeled + 100 ng LXA4),with 12 rats in each group.The normal saline (10 μl) or LXA4 (10 μl) was administered intrathecally right after the operation and on each of the three succeeding days.General behavior was observed and the 50％ paw withdrawal threshold (50％ PWT) was measured.On postoperative day 7 all the rats were killed and the ipsilateral lumbar (L4~) segments of their spinal dorsal horns were removed for determination of the expression of p-JNK,t-JNK,p-ERK and t-ERK proteins using western blotting.TNF-α,IL-1β and TGF-β1 expression were determined using ELISA.Results There was no significant difference in the 50％PWT of the sham group before and after surgery,but the 50％ PWTs of the control group and the LXA4 10 ng group were significantly decreased after the operation compared with their values beforehand and significantly lower than the value of the sham group at all time points.Moreover,the 50％ PWT of the LXA4 10 ng group on postoperative days 3 and 5 was significantly higher than the control group;as was the value of the LXA4 100 ng group on postoperative days 2,3,4,5,6 and 7.The p-JNK and p-ERK expression in the control group,the LXA4 10 ng group and the LXA4 100 ng group were all increased significantly more than in the sham group,but their expression in the LXA4 10 ng group and LXA4 100 ng group were decreased significantly more in a dose-dependent manner compared with the control group,with the LXA4 100 ng group showing the greatest decrease.There were no significant differences in t-JNK or t-ERK expression within each group.Conclusion LXA4 can alleviate radicular pain caused by non-compressive lumbar intervertebral disc herniation.The underlying mechanism involves inhibiting the activation of the ERK and JNK pathways,reducing the expression of pro-inflammatory cytokines and increasing the expression of anti-inflammatory cytokines.
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Objective To evaluate the effect of BML?111 on ventilator?induced lung injury in rats. Methods Forty?eight healthy male Sprague?Dawley rats, weighing 200-250 g, aged 6-8 weeks, were randomized into 6 groups ( n=8 each) using a random number table: control group ( C group) , low tidal volume (VT) group (LVTgroup), high VT group (HVTgroup), low dose BML?111 group (BL group), high dose BML?111 group ( BH group) , and BML?111 plus BOC?2 ( lipoxin A4 receptor antagonist) group ( BOC?2 group) . Group C kept spontaneous breathing after tracheotomy, and received no mechanical venti?lation. The rats in the other 5 groups were mechanically ventilated ( respiratory rate 80 breaths∕min, frac? tion of inspired oxygen 21%, positive end?expiratory pressure 0) . The VT was 6 ml∕kg in group LVT , or 20 ml∕kg in HVT, BL, BH and BOC?2 groups. BML?111 0?1 and 1?0 mg∕kg were injected intraperitoneally during ventilation in BL and BH groups, respectively. In group BOC?2, BOC?2 50 μg∕kg was injected in?traperitoneally before ventilation, and BML?111 1?0 mg∕kg was injected intraperitoneally during ventilation. Arterial blood samples were collected at 4 h of ventilation, arterial oxygen partial pressure ( PaO2 ) was de?termined. Then animals were sacrificed by exsanguination. Bronchoalveolar lavage fluid ( BALF) of the left lung was collected for determination of neutrophil count, and the level of neutrophil was calculated. The right lung tissue specimens were obtained for microscopic examination, and for determination of wet∕dry lung weight ratio ( W∕D ratio ) , myeloperoxidase ( MPO ) activity, and contents of malondialdehyde ( MDA) , monocyte chemoattractant protein?1 ( MCP?1) , tumor necrosis factor?alpha ( TNF?α) , interleu?kin?1beta ( IL?1β) and IL?6. Results Compared with group C, PaO2 was significantly decreased, and the level of neutrophil in BALF, W∕D ratio, MPO activity, and contents of MDA, MCP?1, TNF?α, IL?1β and IL?6 were increased in group HVT ( P0?05) . Compared with group HVT , PaO2 was significantly increased, and the level of neutrophil in BALF, W∕D ratio, MPO activity, and contents of MDA, MCP?1, TNF?α, IL?1β and IL?6 were decreased in group BH, and the contents of TNF?α, IL?1βand IL?6 were significantly decreased ( P0?05) . Compared with group BH, PaO2 was significantly decreased, and the level of neutrophil in BALF, W∕D ratio, MPO activity, and contents of MDA, MCP?1, TNF?α, IL?1β and IL?6 were increased in group BOC?2 (P<0?05). The pathological changes were significantly attenuated in group BL as compared with HVT and BOC?2 groups. Conclusion BML?111 can attenuate ventilator?induced lung injury in rats, and activated lipoxin A4 receptors are involved in the mechanism.
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Objective To evaluate the effect of BML-111 on NF-κB pathway during acute lung injury induced by hemorrhagic shock and resuscitation in rats.Methods Thirty-two adult male Sprague-Dawley rats,weighing 200-250 g,were randomly divided into 4 groups (n =8 each) using a random number table:sham operation group (group S),hemorrhagic shock and resuscitation group (group HSR),BML-111 group,and BML-111 + BOC-2 (lipoxin A4 receptor antagonist) group (group BOC-2).The animals were anesthetized with intraperitoneal pentobarbital sodium.Hemorrhagic shock was induced by blood letting and maintained for 30 min.The animals were then resuscitated for 30 min by infusion of the shed blood and lactated Ringer's solution.In group BOC-2,BOC-2 (50 μg/kg) was injected intraperitoneally before blood letting.In BML-111 and BOC-2 groups,BML-111 (1 mg/kg) was injected intraperitoneally at the beginning of resuscitation.The rats were sacrificed at 2 h after the end of resuscitation and lungs were removed for determination of pathological changes,myeloperoxidase (MPO) activity,intercellular adhesion molecule-1 (ICAM-1) expression (by immunohistochemistry),tumor necrosis factor-alpha (TNF-α) content (by ELISA),and NF-κB p65 and IκB-α expression (by Western blot).Results Compared with group S,the MPO activity,ICAM-1 expression,and TNF-α content were significantly increased,NF-κB p65 expression was up-regulated,and IκB-α expression was down-regulated in group HSR.Compared with group.HSR,the MPO activity,ICAM-1 expression,and TNF-α content were significantly decreased,NF-κB p65 expression was down-regulated,IκB-α expression was up-regulated,and pathological changes of lung were attenuated in group BML-111.Compared with group BML-111,the MPO activity,ICAM-1 expression,and TNF-α content were significantly increased,NF-κB p65 expression was up-regulated,and lκ:B-α expression was down-regulated,and pathological changes of lung were aggravated in group BOC-2.Conclusion BML-1 11 inhibits activation of NF-κB pathway and inflammatory responses,thus mitigating acute lung injury induced by hemorrhagic shock and resuscitation in rats.
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The morbidity of obesity-related glomerulopathy(ORG) is on the increase in recent years.Studies have demonstrated that the chronic inflammation may play a key role in the pathogenesis of obesity related metabolic dysfunction.LipoxinA4 (LXA4) is an important anti-inflammatory lipid mediator,which is well known as the stop signal of the inflammatory reaction that can promote the resolution of inflammation.This review will provide a survey of recent advances on ORG and LXA4.