The Role of Monoacylglycerol Lipase (MAGL) in the Cancer Progress

In recent years, metabolism is talked highly important in cancer research, especially the lipid metabolism. Researchers believe that the de novo fatty acid synthesis plays an important role in tumor development, while many studies illustrated that Endocannabinoids have anti-tumorigenic actions, including anti-proliferation, apoptosis induction, and anti-metastatic effects, MAGL as an important decomposing enzyme of both lipid metabolism and endocannabinoids system, additionally as a part of a gene expression signature contributes to different aspects of tumourigenesis.     

Clarithromycin Attenuates Radiation-Induced Lung Injury in Mice

Radiation-induced lung injury (RILI) is a common and unavoidable complication of thoracic radiotherapy. The current study was conducted to evaluate the ability of clarithromycin (CLA) to prevent radiation-induced pneumonitis, oxidative stress, and lung fibrosis in an animal model. C57BL/6J mice were assigned to control, irradiation only, irradiation plus CLA, and CLA only groups. Test mice received single thoracic exposures to radiation and/or oral CLA (100 mg/kg/day). Histopathologic findings and markers of inflammation, fibrosis, and oxidative stress were compared by group. On a microscopic level, CLA inhibited macrophage influx, alveolar fibrosis, parenchymal collapse, consolidation, and epithelial cell changes. The concentration of collagen in lung tissue was lower in irradiation plus CLA mice. Radiation-induced expression of tumor necrosis factor (TNF)-α, TNF receptor 1, acetylated nuclear factor kappa B, cyclooxygenase 2, vascular cell adhesion molecule 1, and matrix metallopeptidase 9 were also attenuated by CLA. Expression levels of nuclear factor erythroid 2-related factor 2 and heme oxygenase 1, transforming growth factor-β1, connective tissue growth factor, and type I collagen in radiation-treated lungs were also attenuated by CLA. These findings indicate that CLA ameliorates the deleterious effects of thoracic irradiation in mice by reducing pulmonary inflammation, oxidative damage, and fibrosis.     

NMDA Receptor Antagonist Attenuates Bleomycin-Induced Acute Lung Injury

Background

Glutamate is a major neurotransmitter in the central nervous system (CNS). Large amount of glutamate can overstimulate N-methyl-D-aspartate receptor (NMDAR), causing neuronal injury and death. Recently, NMDAR has been reported to be found in the lungs. The aim of this study is to examine the effects of memantine, a NMDAR channel blocker, on bleomycin-induced lung injury mice.

Methods

C57BL/6 mice were intratracheally injected with bleomycin (BLM) to induce lung injury. Mice were randomized to receive saline, memantine (Me), BLM, BLM plus Me. Lungs and BALF were harvested on day 3 or 7 for further evaluation.

Results

BLM caused leukocyte infiltration, pulmonary edema and increase in cytokines, and imposed significant oxidative stress (MDA as a marker) in lungs. Memantine significantly mitigated the oxidative stress, lung inflammatory response and acute lung injury caused by BLM. Moreover, activation of NMDAR enhances CD11b expression on neutrophils.

Conclusions

Memantine mitigates oxidative stress, lung inflammatory response and acute lung injury in BLM challenged mice.     

N-Acetyl-Heparin Attenuates Acute Lung Injury Caused by Acid Aspiration Mainly by Antagonizing Histones in Mice

Acute lung injury (ALI) is the leading cause of death in intensive care units. Extracellular histones have recently been recognized to be pivotal inflammatory mediators. Heparin and its derivatives can bind histones through electrostatic interaction. The purpose of this study was to investigate 1) the role of extracellular histones in the pathogenesis of ALI caused by acid aspiration and 2) whether N-acetyl-heparin (NAH) provides more protection than heparin against histones at the high dose. ALI was induced in mice via intratracheal instillation of hydrochloric acid (HCl). Lethality rate, blood gas, myeloperoxidase (MPO) activity, lung edema and pathological changes were used to evaluate the degree of ALI. Heparin/NAH was administered intraperitoneally, twice a day, for 3 days or until death. Acid aspiration caused an obvious increase in extracellular histones. A significant correlation existed between the concentration of HCl aspirated and the circulating histones. Heparin/NAH (10 mg/kg) improved the lethality rate, blood gas, MPO activity, lung edema and pathological score. At a dose of 20 mg/kg, NAH still provided protection, however heparin tended to aggravate the injury due to hemorrhagic complications. The specific interaction between heparin and histones was verified by the binding assay. In summary, high levels of extracellular histones can be pathogenic in ALI caused by acid aspiration. By neutralizing extracellular histones, heparin/NAH can offer similar protection at the moderate doses. At the high dose, NAH provides better protection than heparin.     

热休克因子1通过上调蛋白质C减轻脓毒症凝血功能障碍保护小鼠急性肺损伤

目的 探讨热休克因子1 （HSF1）减轻脓毒症凝血功能障碍,保护小鼠急性肺损伤的机制。方法 本研究采用盲肠结扎穿孔术（cecal ligation and puncture,CLP）制备脓毒症小鼠模型,检测凝血相关指标和观察小鼠肺部病理变化,通过酶联免疫吸附实验（ELISA）、q RT-PCR和蛋白质印迹法（Western blot）等方法检测蛋白质C表达水平,通过质粒转染抑制或增强HSF1表达从而观察蛋白质C表达水平的变化,并利用生物信息学、凝胶电泳迁移实验（EMSA）和双荧光素酶报告基因实验探讨HSF1调节蛋白质C转录的机制。结果 在CLP脓毒症小鼠模型中,HSF-/-组小鼠的凝血活性与HSF1^+/+组相比明显增强,肺损伤明显加重。ELISA、qRT-PCR和Western blot检测发现,HSF^-/-脓毒症小鼠血浆和肺组织中的蛋白质C表达水平显著低于野生型小鼠。体外bEnd.3血管内皮细胞的实验结果显示,HSF1抑制脂多糖（LPS）诱导的蛋白质C表达,HSF1过表达则增强蛋白质C表达。生物信息学数据分析提示,蛋白质C启动子区含有HSF...     

Pressure Controlled Ventilation to Induce Acute Lung Injury in Mice

Murine models are extensively used to investigate acute injuries of different organs systems (1-34). Acute lung injury (ALI), which occurs with prolonged mechanical ventilation, contributes to morbidity and mortality of critical illness, and studies on novel genetic or pharmacological targets are areas of intense investigation (1-3, 5, 8, 26, 30, 33-36). ALI is defined by the acute onset of the disease, which leads to non-cardiac pulmonary edema and subsequent impairment of pulmonary gas exchange (36). We have developed a murine model of ALI by using a pressure-controlled ventilation to induce ventilator-induced lung injury (2). For this purpose, C57BL/6 mice are anesthetized and a tracheotomy is performed followed by induction of ALI via mechanical ventilation. Mice are ventilated in a pressure-controlled setting with an inspiratory peak pressure of 45 mbar over 1 - 3 hours. As outcome parameters, pulmonary edema (wet-to-dry ratio), bronchoalveolar fluid albumin content, bronchoalveolar fluid and pulmonary tissue myeloperoxidase content and pulmonary gas exchange are assessed (2). Using this technique we could show that it sufficiently induces acute lung inflammation and can distinguish between different treatment groups or genotypes (1-3, 5). Therefore this technique may be helpful for researchers who pursue molecular mechanisms involved in ALI using a genetic approach in mice with gene-targeted deletion.     

Stimulation of Brain AMP-Activated Protein Kinase Attenuates Inflammation and Acute Lung Injury in Sepsis

Sepsis and septic shock are enormous public health problems with astronomical financial repercussions on health systems worldwide. The central nervous system (CNS) is closely intertwined in the septic process but the underlying mechanism is still obscure. AMP-activated protein kinase (AMPK) is a ubiquitous energy sensor enzyme and plays a key role in regulation of energy homeostasis and cell survival. In this study, we hypothesized that activation of AMPK in the brain would attenuate inflammatory responses in sepsis, particularly in the lungs. Adult C57BL/6 male mice were treated with 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR, 20 ng), an AMPK activator, or vehicle (normal saline) by intracerebroventricular (ICV) injection, followed by cecal ligation and puncture (CLP) at 30 min post-ICV. The septic mice treated with AICAR exhibited elevated phosphorylation of AMPKα in the brain along with reduced serum levels of aspartate aminotransferase, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6), compared with the vehicle. Similarly, the expressions of TNF-α, IL-1β, keratinocyte-derived chemokine and macrophage inflammatory protein-2 as well as myeloperoxidase activity in the lungs of AICAR-treated mice were significantly reduced. Moreover, histological findings in the lungs showed improvement of morphologic features and reduction of apoptosis with AICAR treatment. We further found that the beneficial effects of AICAR on septic mice were diminished in AMPKα2 deficient mice, showing that AMPK mediates these effects. In conclusion, our findings reveal a new functional role of activating AMPK in the CNS to attenuate inflammatory responses and acute lung injury in sepsis.     

Inhibition of Monoacylglycerol Lipase Activity Decreases Glucose-Stimulated Insulin Secretion in INS-1 (832/13) Cells and Rat Islets

Lipid signals derived from lipolysis and membrane phospholipids play an important role in glucose-stimulated insulin secretion (GSIS), though the exact secondary signals remain unclear. Previous reports have documented a stimulatory role of exogenously added mono-acyl-glycerol (MAG) on insulin secretion from cultured β-cells and islets. In this report we have determined effects of increasing intracellular MAG in the β-cell by inhibiting mono-acyl-glycerol lipase (MGL) activity, which catalyzes the final step in triacylglycerol breakdown, namely the hydrolysis of MAG to glycerol and free fatty acid (FA). To determine the role of MGL in GSIS, we used three different pharmacological agents (JZL184, MJN110 and URB602). All three inhibited GSIS and depolarization-induced insulin secretion in INS-1 (832/13). JZL184 significantly inhibited both GSIS and depolarization-induced insulin secretion in rat islets. JZL184 significantly decreased lipolysis and increased both mono- and diacyglycerol species in INS-1 cells. Analysis of the kinetics of GSIS showed that inhibition was greater during the sustained phase of secretion. A similar pattern was observed in the response of Ca²⁺ to glucose and depolarization but to a lesser degree suggesting that altered Ca²⁺ handling alone could not explain the reduction in insulin secretion. In addition, a significant reduction in long chain-CoA (LC-CoA) was observed in INS-1 cells at both basal and stimulatory glucose following inhibition of MGL. Our data implicate an important role for MGL in insulin secretion.     

α-酮戊二酸减轻脂多糖/D-半乳糖胺诱导的小鼠急性肝损伤

该文旨在探讨α-酮戊二酸对脂多糖(lipopolysaccharide,LPS)及D-半乳糖胺(d-galac-tosamine,D-Ga1)诱导的急性肝损伤发生发展的影响及其可能机制.实验分组:正常对照组、AKG单独处理组、LPS/D-Ga1组、LPS/D-Ga1+AKG组.在雄性BALB/c小鼠中,经腹腔注射LPS...     

急性肺损伤的生物标记物

急性呼吸窘迫综合征(ARDS)和急性肺损伤(ALI)多由低氧性呼吸衰竭引起,导致高通透性肺水肿,临床上有较高的发病率与死亡率。近十年来,针对血浆和支气管肺泡灌洗液中相关生物标记物的研究为探索急性肺损伤的病理生理机制指明了新的方向。个别生物标记物已在一些大型、多中心ARDS试验中得到证实。但迄今仍没有一个或一组生物标记物常规应用于临床。随着人类对ALI发病机制理解的进一步深入,或许不久的将来,生物标记物会真正应用于评估疾病的严重程度和预后。本文将概述近年来ALI相关生物标记物的研究进展。     

NLRP1-Dependent Pyroptosis Leads to Acute Lung Injury and Morbidity in Mice

Acute inflammation in response to both exogenous and endogenous danger signals can lead to the assembly of cytoplasmic inflammasomes that stimulate the activation of caspase-1. Subsequently, caspase-1 facilitates the maturation and release of cytokines and also, under some circumstances, the induction of cell death by pyroptosis. Using a mouse line lacking expression of NLRP1, we show that assembly of this inflammasome in cells is triggered by a toxin from anthrax and that it initiates caspase-1 activation and release of IL-1β. Furthermore, NLRP1 inflammasome activation also leads to cell death, which escalates over 3 d following exposure to the toxin and culminates in acute lung injury and death of the mice. We show that these events are not dependent on production of IL-1β by the inflammasome but are dependent on caspase-1 expression. In contrast, muramyl dipeptide-mediated inflammasome formation is not dependent on NLRP1 but NLRP3. Taken together, our findings show that assembly of the NLRP1 inflammasome is sufficient to initiate pyroptosis, which subsequently leads to a self-amplifying cascade of cell injury within the lung from which the lung cannot recover, eventually resulting in catastrophic consequences for the organism.     

原儿茶酸对脂多糖诱导的急性肺损伤小鼠的保护作用

目的:探索原儿茶酸(protocatechuicacid,PCA)对脂多糖(lipopolysaccharide,LPS)诱导的急性肺损伤(acute lung injury,ALI)小鼠的保护作用,探讨其保护机制。方法:将40只昆明小鼠按随机数字表法均分为空白对照组(NC组)、LPS模型组、原儿茶酸预处理组(PCA+LPS组)、地塞米松阳性对照组(Dex+LPS组),每组10只,模型组以5mg·kg-1脂多糖腹腔内注射诱导急性肺损伤。6h后处死小鼠,HE染色观察肺组织病理学变化;BCA法检测肺泡灌洗液中总蛋白浓度;ELISA检测肺泡灌洗液炎症因子TNF-α、IL-1β含量;Western Blot检测肺组织中p38MAPK、p-p38MAPK、p-ATF2蛋白的表达水平。结果:与对照组相比,模型组小鼠肺损伤明显,肺泡内出血、水肿、炎细胞浸润,肺泡灌洗液中TNF-α、IL-1β的含量及总蛋白浓度增加,肺组织中p38MAPK/p-p38MAPK、p-ATF2表达均明显增加(均P0.01)。与模型组相比,原儿茶酸预处理组、地塞米松阳性对照组肺组织病理损伤程度明显减轻,肺泡灌洗液中TNF-α、IL-1β的含量及总蛋白浓度、肺组织中p38MAPK/p-p38MAPK、p-ATF2表达均明显降低(均P0.01)。结论:PCA对LPS诱导的急性肺损伤有保护作用,其作用机制可能与其抑制p38MAPK-p-ATF2信号通路的活化、降低肺组织炎症反应有关。     

大鼠胰腺炎相关性急性肺损伤模型的探讨

目的研究5%牛磺胆酸钠(TAC)逆行胆胰管注射诱发急性胰腺炎相关肺损伤的大鼠模型。方法采用改进的胆胰管逆行注射TAC造成大鼠急性出血坏死型胰腺炎(AHNP)模型,将大鼠随机分为3组:AHNP组、假手术组、地塞米松(DXM)治疗组。造模成功后,立即静脉注射大剂量DXM(5 mg/kg)。术后于3、6、12 h处死,留取外周血测定血清淀粉酶、脂肪酶,取右肺中叶测定肺湿干比值及作病理切片,计算等级评分评价肺损伤;行支气管肺泡灌洗,以灌洗液白蛋白与血清白蛋白含量比值计算肺指数。结果AHNP组36、、12 h肺通透性指数、湿干比值及病理学评分逐渐增加,经单因素方差分析,61、2 h组高于3 h组(P<0.05),前两者于6、12 h组组内比较差异不显著(P>0.05)。DXM组于术后61、2 h,各项肺损伤指标均低于AHNP组(P<0.05)。结论TAC胆胰管逆行注射造成AHNP模型大鼠于术后6 h即出现明显的肺损伤表现,符合PALI病理改变,与临床AHNP合并急性肺损伤(ALI)的病理过程相似,可于此时相点作为研究AHNP合并肺损伤的模型。     

Inhibition of Peroxynitrite-Induced Mitophagy Activation Attenuates Cerebral Ischemia-Reperfusion Injury

Activated autophagy/mitophagy has been intensively observed in ischemic brain, but its roles remain controversial. Peroxynitrite (ONOO^?), as a representative of reactive nitrogen species, is considered as a critical neurotoxic factor in mediating cerebral ischemia-reperfusion (I/R) injury, but its roles in autophagy/mitophagy activation remain unclear. Herein, we hypothesized that ONOO^? could induce PINK1/Parkin-mediated mitophagy activation via triggering dynamin-related protein 1 (Drp1) recruitment to damaged mitochondria, contributing to cerebral I/R injury. Firstly, we found PINK1/Parkin-mediated mitophagy activation was predominant among general autophagy, leading to rat brain injury at the reperfusion phase after cerebral ischemia. Subsequently, increased nitrotyrosine was found in the plasma of ischemic stroke patients and ischemia-reperfused rat brains, indicating the generation of ONOO^? in ischemic stroke. Moreover, in vivo animal experiments illustrated that ONOO^? was dramatically increased, accompanied with mitochondrial recruitment of Drp1, PINK1/Parkin-mediated mitophagy activation, and progressive infarct size in rat ischemic brains at the reperfusion phase. FeTMPyP, a peroxynitrite decomposition catalyst, remarkably reversed mitochondrial recruitment of Drp1, mitophagy activation, and brain injury. Intriguingly, further study revealed that ONOO^? induced tyrosine nitration of Drp1 peptide, which might contribute to mitochondrial recruitment of Drp1 for mitophagy activation. In vitro cell experiments yielded consistent results with in vivo animal experiments. Taken together, all above findings support the hypothesis that ONOO^?-induced mitophagy activation aggravates cerebral I/R injury via recruiting Drp1 to damaged mitochondria.     

Knock Out of S1P3 Receptor Signaling Attenuates Inflammation and Fibrosis in Bleomycin-Induced Lung Injury Mice Model

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid metabolite involved in many critical cellular processes, including proliferation, migration, and angiogenesis, through interaction with a family of five G protein–coupled receptors (S1P1–5). Some reports have implicated S1P as an important inflammatory mediator of the pathogenesis of airway inflammation, but the role of S1P3 in the pathogenesis of lung diseases is not completely understood. We used S1P3-deficient (knockout (KO)) mice to clarify the role of S1P3 receptor signaling in the pathogenesis of pulmonary inflammation and fibrosis using a bleomycin-induced model of lung injury. On the seventh day after bleomycin administration, S1P3 KO mice exhibited significantly less body weight loss and pulmonary inflammation than wild-type (WT) mice. On the 28th day, there was less pulmonary fibrosis in S1P3 KO mice than in WT mice. S1P3 KO mice demonstrated a 56% reduction in total cell count in bronchoalveolar lavage fluid (BALF) collected on the seventh day compared with WT mice; however, the differential white blood cell profiles were similar. BALF analysis on the seventh day showed that connective tissue growth factor (CTGF) levels were significantly decreased in S1P3 KO mice compared with WT mice, although no differences were observed in monocyte chemotactic protein-1 (MCP-1) or transforming growth factor β1 (TGF-β1) levels. Finally, S1P levels in BALF collected on the 7th day after treatment were not significantly different between WT and S1P3 KO mice. Our results indicate that S1P3 receptor signaling plays an important role in pulmonary inflammation and fibrosis and that this signaling occurs via CTGF expression. This suggests that this pathway might be a therapeutic target for pulmonary fibrosis.     

Inhibiting Monoacylglycerol Acyltransferase 1 Ameliorates Hepatic Metabolic Abnormalities but Not Inflammation and Injury in Mice

Abnormalities in hepatic lipid metabolism and insulin action are believed to play a critical role in the etiology of nonalcoholic steatohepatitis. Monoacylglycerol acyltransferase (MGAT) enzymes convert monoacylglycerol to diacylglycerol, which is the penultimate step in one pathway for triacylglycerol synthesis. Hepatic expression of Mogat1, which encodes an MGAT enzyme, is increased in the livers of mice with hepatic steatosis, and knocking down Mogat1 improves glucose metabolism and hepatic insulin signaling, but whether increased MGAT activity plays a role in the etiology of nonalcoholic steatohepatitis is unclear. To examine this issue, mice were placed on a diet containing high levels of trans fatty acids, fructose, and cholesterol (HTF-C diet) or a low fat control diet for 4 weeks. Mice were injected with antisense oligonucleotides (ASOs) to knockdown Mogat1 or a scrambled ASO control for 12 weeks while remaining on diet. The HTF-C diet caused glucose intolerance, hepatic steatosis, and induced hepatic gene expression markers of inflammation, macrophage infiltration, and stellate cell activation. Mogat1 ASO treatment, which suppressed Mogat1 expression in liver and adipose tissue, attenuated weight gain, improved glucose tolerance, improved hepatic insulin signaling, and decreased hepatic triacylglycerol content compared with control ASO-treated mice on HTF-C chow. However, Mogat1 ASO treatment did not reduce hepatic diacylglycerol, cholesterol, or free fatty acid content; improve histologic measures of liver injury; or reduce expression of markers of stellate cell activation, liver inflammation, and injury. In conclusion, inhibition of hepatic Mogat1 in HTF-C diet-fed mice improves hepatic metabolic abnormalities without attenuating liver inflammation and injury.