In Silico Cloning and Sequence Analysis of Phospholipase Dα Gene from Peach Fruit

Phospholipase D （PLD, EC 3.1.4.4） plays an important role in adaptive response of postharvest fruit to environment. In this study, a novel cDNA of PLDα was isolated with the strategy of in silico cloning in combination with RT-PCR from peach （Prunus persica L. cv. Jiubao）. The obtained PLDα gene contained a complete open reading frame encoding a 92- kDa protein of 810 amino acid residues, which possessed the characteristic C2 domain and two catalytic HKD motifs. The alignment analysis of the deduced peach PLDa protein with other known PLDα family proteins indicated that peach PLDα was conserved and highly homologous with strawberry PLDα. Semi-quantitative RT-PCR and Northern blot analysis indicated PLDα mRNA in peach fruits could be induced by low temperature. This work provided a scientific basis for further investigating the mechanism of postharvest fruit adaptation to low temperature.

Clinical effects of phospholipase D2 in attenuating acute pancreatitis

BACKGROUND The objective of the current study was to elucidate the clinical mechanism through which phospholipase D2(PLD2)exerted a regulatory effect on neutrophil migra-tion,thereby alleviating the progression of acute pancreatitis.AIM To elucidate the clinical mechanism through which PLD2 exerted a regulatory effect on neutrophil migration,thereby alleviating the progression of acute pan-creatitis.METHODS The study involved 90 patients diagnosed with acute pancreatitis,admitted to our hospital between March 2020 and November 2022.A retrospective analysis was conducted,categorizing patients based on Ranson score severity into mild(n=25),moderate(n=30),and severe(n=35)groups.Relevant data was collected for each group.Western blot analysis assessed PLD2 protein expression in patient serum.Real-time reverse transcription polymerase chain reaction was used to evaluate the mRNA expression of chemokine receptors associated with neutrophil migration.Serum levels of inflammatory factors in patients were detected using enzyme-linked immunosorbent assay.Transwell migration tests were conducted to compare migration of neutrophils across groups and analyze the influence of PLD2 on neutrophil migration.RESULTS Overall data analysis did not find significant differences between patient groups(P>0.05).The expression of PLD2 protein in the severe group was lower than that in the moderate and mild groups(P<0.05).The expression level of PLD2 in the moderate group was also lower than that in the mild group(P<0.05).The severity of acute pancreatitis is negatively correlated with PLD2 expression(r=-0.75,P=0.002).The mRNA levels of C-X-C chemokine receptor type 1,C-X-C chemokine receptor type 2,C-C chemokine receptor type 2,and C-C chemokine receptor type 5 in the severe group are significantly higher than those in the moderate and mild groups(P<0.05),and the expression levels in the moderate group are also higher than those in the mild group(P<0.05).The levels of C-reactive protein,tumor necrosis factor-α,interleukin-1β,and interleukin-6 in the severe group were higher than those in the moderate and mild groups(P<0.05),and the levels in the moderate group were also higher than those in the mild group(P<0.05).The number of migrating neutrophils in the severe group was higher than that in the moderate and mild groups(P<0.05),and the moderate group was also higher than the mild group(P<0.05).In addition,the number of migrating neutrophils in the mild group combined with PLD2 inhibitor was higher than that in the mild group(P<0.05),and the number of migrating neutrophils in the moderate group combined with PLD2 inhibitor was higher than that in the moderate group(P<0.05).The number of migrating neutrophils in the severe group+PLD2 inhibitor group was significantly higher than that in the severe group(P<0.05),indicating that PLD2 inhibitors significantly stimulated neutrophil migration.CONCLUSION PLD2 exerted a crucial regulatory role in the pathological progression of acute pancreatitis.Its protein expression varied among patients based on the severity of the disease,and a negative correlation existed between PLD2 expression and disease severity.Additionally,PLD2 appeared to impede acute pancreatitis progression by limiting neutrophil migration.

Plasma Lysophosphatidylcholine and Phospholipase A2 Activity in Chagas Disease Patients: A Comparative Analysis

Chagas disease (CD) affects 21 countries in the Americas and is caused by the parasite Trypanosoma cruzi. A key molecule involved in CD is lysophosphatidylcholine (LPC), which has been studied in various contexts: in the saliva of insect vectors, during the establishment of infection in the vertebrate host, and for the parasite itself. This lipid can be produced by the action of phospholipases A2 (PLA2), enzymes that catalyze the hydrolysis of phospholipids releasing fatty acids and lysophospholipids, such as LPC. This study investigates LPC levels and PLA2 activities in the plasma of CD patients and compares these levels with those in healthy individuals and patients with idiopathic dilated cardiomyopathy (IDCM). Plasma from 64 CD patients, 54 healthy individuals, and 16 IDCM patients were analyzed. LPC levels and the activity of two types of phospholipase A2: secreted (sPLA2) and lipoprotein-associated (Lp-PLA2) were measured. LPC levels and sPLA2 activity were similar between CD patients and the control groups. However, there were notable differences in LPC levels and sPLA2 activity between subgroups of CD patients and IDCM patients. This study is the first to identify LPC in patients with CD across various stages of the disease. It also offers new insights into the biochemical changes observed in the plasma of patients with IDCM.

High patatin like phospholipase domain containing 8 expression as a biomarker for poor prognosis of colorectal cancer

BACKGROUND Patatin like phospholipase domain containing 8(PNPLA8)has been shown to play a significant role in various cancer entities.Previous studies have focused on its roles as an antioxidant and in lipid peroxidation.However,the role of PNPLA8 in colorectal cancer(CRC)progression is unclear.AIM To explore the prognostic effects of PNPLA8 expression in CRC.METHODS A retrospective cohort containing 751 consecutive CRC patients was enrolled.PNPLA8 expression in tumor samples was evaluated by immunohistochemistry staining and semi-quantitated with immunoreactive scores.CRC patients were divided into high and low PNPLA8 expression groups based on the cut-off va-lues,which were calculated by X-tile software.The prognostic value of PNPLA8 was identified using univariate and multivariate Cox regression analysis.The over-all survival(OS)rates of CRC patients in the study cohort were compared with Kaplan-Meier analysis and Log-rank test.RESULTS PNPLA8 expression was significantly associated with distant metastases in our cohort(P=0.048).CRC patients with high PNPLA8 expression indicated poor OS(median OS=35.3,P=0.005).CRC patients with a higher PNPLA8 expression at either stage I and II or stage III and IV had statistically significant shorter OS.For patients with left-sided colon and rectal cancer,the survival curves of two PN-PLA8-expression groups showed statistically significant differences.Multivariate analysis also confirmed that high PNPLA8 expression was an independent prog-nostic factor for overall survival(hazard ratio HR=1.328,95%CI:1.016-1.734,P=0.038).

维生素D治疗全面性发育迟缓患儿的临床疗效研究

背景 除了某些有明确病因的代谢性疾病导致的全面性发育迟缓(GDD),康复治疗是GDD的主要治疗方式;维生素D通过影响神经营养因子在调节神经细胞的发育和分化方面发挥着重要的神经保护作用;但目前关于补充维生素D对GDD患儿临床疗效的研究开展较少。目的 探讨补充不同剂量的维生素D对GDD患儿康复治疗的临床效果。方法 于2020年9月—2022年6月选取在郑州大学第三附属医院康复医学科首次住院就诊的120例GDD患儿为研究对象,采用随机区组化的方法将其分为常规组(38例)、400 U组(37例)和1 200 U组(35例)。常规组仅进行常规康复治疗;400 U组在常规康复治疗的基础上给予口服400 U/d维生素D;1 200 U组在常规康复训练的基础上给予口服1 200 U/d维生素D。收集3组患儿的性别、就诊年龄等基本资料;于入院时(治疗前)及第3个疗程末(治疗后)行血清25羟维生素D[25(OH)D]水平检测和Gesell发育量表评估[评估适应能力、大运动能力、精细运动能力、语言能力和社交能力5个能区的发育商(DQ)];记录发生在患儿住院期间不良事件的次数,并对上述资料进行分析比较。结果 3组患儿性别、居住地、出生季节、分娩方式、就诊年龄、出生体质量、出生胎龄、主要就诊原因比较,差异均无统计学意义(P>0.05)。治疗前,3组患儿25(OH)D水平、Gesell量表各能区DQ值比较,差异均无统计学意义(P>0.05);治疗后,1 200 U组患儿血25(OH)D水平、Gesell量表大运动能力、精细运动能力、语言能力DQ值高于常规组(P<0.05)。第1、2疗程期间,3组患儿不良事件发生率比较,差异无统计学意义(P>0.05);第3疗程期间,1 200 U组患儿不良事件发生率低于常规组及400 U组(P<0.05)。结论 补充1 200 U维生素D对GDD患儿的康复疗效有益,且能减少康复期间不良事件的发生率。

复杂越野场景无人履带平台3D语义占据预测方法

为了理解和处理复杂越野场景中环境要素形状不规则、地形多变及路面属性复杂等问题,提出了一种基于多模态融合感知的3D语义占据预测方法.首先,基于图像和激光雷达融合网络获取初始3D语义标签;然后,对越野场景稀疏点云采用贝叶斯稠密化算法补全3D语义占据标签;最后,生成包含复杂环境要素大小、位置和语义信息的3D语义占据栅格地图.试验结果表明,该方法能够有效地提取和表示复杂越野环境中的3D信息,为复杂越野环境下无人履带平台的路径规划提供了更加准确和丰富的先验信息.

3D打印矩形粗糙通道内火箭煤油流动换热特性试验方法研究

为探究3D打印再生冷却通道在液体火箭发动机推力室中的替代应用特性,研制了具有不同内表面粗糙度的正弦波纹结构3D打印304不锈钢矩形通道。内截面名义尺寸为2.0 mm×2.0 mm,设计粗糙度分别为6.3、25.0、100.0μm,实际粗糙度Ra分别为11.88、12.70、17.53μm,通过将高温电阻率法和像素法相结合获得了3D打印通道的实际内径和壁厚,修正了火箭煤油流动换热的内壁温和热流密度,建立了3D打印粗糙通道内火箭煤油流动换热特性试验研究方法。试验参数如下:压力处于15~20 MPa范围、质量流速在12450~24900 kg·m^(-2)·s^(-1)之间、热流密度为5~15 MW·m^(-2)、流体温度为-150℃。研究结果表明:火箭煤油流动换热特性受到热流密度、流体温度和质量流速的影响;流体温度处于50~135℃范围内,换热系数增加约25%~33%;热流密度处于5.0~15.0 MW·m^(-2)范围内,换热系数增加了8.3%;质量流速为12450~24900 kg·m^(-2)·s^(-1)范围内,换热系数增加了60.2%。粗糙度增加对火箭煤油流动换热起到强化作用,粗糙度从11.88μm增加到17.53μm时,换热强化幅度超过20%以上。该研究可为3D打印通道在火箭发动机推力室中的替代应用提供参考。

绝经后女性维生素D水平与生殖特点和运动膳食情况的关系

背景:研究证明绝经后骨质疏松症与女性生殖特点和运动膳食有关,但是鲜有研究证明女性生殖特点及运动膳食是否对绝经后女性维生素D有影响。目的:探讨北京市绝经后女性维生素D水平与女性生殖特点和运动膳食情况的关系及其影响因素。方法:选取2017年9月至2018年5月北京市多个城区的17个社区现场问卷调查的727例46-75岁绝经后女性作为研究对象,问卷内容包括受试者的基本信息和月经史、绝经史、妊娠史、运动膳食情况等。采用电化学发光免疫分析仪及其配套试剂测定25-(OH)D水平;使用双能X射线骨密度检测仪测定腰椎(L1-L4、整体)和双髋关节(股骨颈、整体)的骨密度和T值;观察维生素D与生殖特点和运动膳食的相关性,并进行维生素D的影响因素分析。结果与结论:①维生素D正常组136例(18.7%),维生素D不足组389例(53.5%),维生素D缺乏组202例(27.8%);平均维生素D水平为(15.60±5.85)ng/mL。②随着维生素D水平的升高,不同部位的骨密度值及T值也随之升高。③维生素D水平与初潮年龄、月经持续天数、绝经阶段、运动情况、饮食类型、饮食偏好均呈正相关(P<0.05);与月经周期、绝经年龄、生育次数均呈负相关(P<0.05);与初孕年龄、怀孕次数无相关性(P>0.05)。④多因素有序Logistic回归分析结果显示,喝奶制品频率对绝经后女性维生素D值存在正向相关(P<0.05),且奶制品是维生素D水平的保护因素。⑤调查结果说明,北京市绝经后女性维生素D水平普遍不足、骨密度值普遍低下,维生素D水平与部分生殖特点、运动膳食情况存在关联,且其中喝奶制品是其保护因素。因此可以通过开展相关骨质疏松的健康教育,对绝经后女性膳食情况进行调整加以干预,增加体内维生素D含量,以期增加骨密度值,减少绝经后骨质疏松患病率。

Lipoprotein-associated phospholipase A2 prognostic role in atherosclerotic complications

Atherosclerosis manifests itself clinically at advanced stages when plaques undergo hemorrhage and/or rupture with superimposed thrombosis, thus abruptly stopping blood supply. Identification of markers of plaque destabilization at a pre-clinical stage is, therefore, a major goal of cardiovascular research. Promising results along this line were provided by studies investigating the lipoprotein-associated phospholipase A2(Lp-PLA2), a member of phospholipase A2 proteins family that plays a key role in the metabolism of pro-inflammatory phospholipids, as oxidized low-density lipoproteins, and in the generation of pro-atherogenic metabolites, including lysophosphatidylcholine and oxidized free fatty acids. We herein review the experimental and clinical studies supporting use of Lp-PLA2 activity for predicting cardiovascular events. To his end we considered not only Lp-PLA2 activity and mass, but also Lp-PLA2 gene variations and their association with incident coronary artery disease, stroke, and cardiovascular mortality. Based on these evidences the major scientific societies have included in their guidelines the measurement of Lp-PLA2 activity among the biomarkers that are useful in risk stratification of adult asymptomatic patients at intermediate cardiovascular risk. The results of two recently published major clinical trials with the LpPLA2 inhibitor darapladib, which seem to challenge the pathogenic role of Lp-PLA2, will also be discussed.

Dual Functions of Phospholipase Dα1 in Plant Response to Drought

Phospholipase Dα1 （PLDα1） has been shown to mediate the abscisic acid regulation of stomatal movements. Arabidopsis plants deficient in PLDα1 increased, whereas PLDα1-overexpressing tobacco decreased, transpirational water loss. In the early stage of drought, the decrease in water loss was associated with a rapid stomatal closure caused by a high level of PLD in PLDα1-overexpressing plants. However, in the late stage of drought, the overexpressing plants displayed more susceptibility to drought than control plants. PLDα1 activity in the overexpressing plants was much higher than that of control plants in which drought also induced an increase in PLDα1 activity. The high level of PLDα1 activity was correlated to membrane degradation in late stages of drought, as demonstrated by ionic leakage and lipid peroxidation. These findings indicate that a high level of PLDα1 expression has different effects on plant response to water deficits. It promotes stomatal closure at earlier stages, but disrupts membranes in prolonged drought stress. These findings are discussed in relation to the understanding of PLD functions and potential applications.

Changes of gastric and intestinal blood flow, serum phospholipase A_2 and interleukin-1β in rats with acute necrotizing pancreatitis

AIM:To explore the relationship between gastric and intestinal microcirculatory impairment and inflammatory mediators released in rats with acute necrotizing pancreatitis (ANP). METHODS: A total of 64 rats were randomized into control group and ANP group. ANP model was induced by injection of 5% sodium taurocholate under the pancreatic membrane. Radioactive biomicrosphere technique was used to measure the gastric and intestinal tissue blood flow at 2 and 12 h after the induction of ANP, meanwhile serum phospholipase A2 (PLA2) activities and interleukin-1β levels were determined. Pathologic changes in pancreas, gastric and intestinal mucosae were studied. RESULTS: The gastric blood flow in ANP group (0.62±0.06 and 0.35±0.05) mL/(min·g) was significantly lower than that in control group (0.86±0.11 and 0.85±0.06) mL/(min·g) (P<0.01) at 2 and 12 h after induction of ANP. The intestinal blood flow in ANP group (0.80±0.07 and 0.50±0.06) mlV(min·g) was significantly lower than that in control group (1.56±0.18 and 1.61±0.11) mL/(min·g) (P<0.01). Serum PLA2 activities (94.29±9.96 and 103.71± 14.40) U/L and IL-1β levels (0.78±0.13 and 0.83±0.20)μg/L in ANP group were higher than those in control group (65.27±10.52 and 66.63±9.81) U/L, (0.32±0.06 and 0.33±0.07)μg/L (P<0.01). At 2 and 12 h after introduction of the model, typical pathologic changes were found in ANP. Compared with control group, the gastric and intestinal mucosal pathologic changes were aggravated significantly (P<0.01) at 12 h after induction of ANP. Gastric and intestinal mucosal necrosis, multiple ulcer and hemorrhage occurred. CONCLUSION: Decrease of gastric and intestinal blood flow and increase of inflammatory mediators occur simultaneously early in ANP, both of them are important pathogenic factors for gastric and intestinal mucosal injury in ANP.

Cytosolic phospholipase A2α modulates cell-matrix adhesion via the FAK/paxillin pathway in hepatocellular carcinoma

Objective: To explore the effect of cytosolic phospholipase A2α(cPLA2α) on hepatocellular carcinoma(HCC) cell adhesion and the underlying mechanisms.Methods: Cell adhesion, detachment, and hanging-drop assays were utilized to examine the effect of cPLA2α on the cell-matrix and cell-cell adhesion. Downstream substrates and effectors of cPLA2α were screened via a phospho-antibody microarray.Associated signaling pathways were identified by the functional annotation tool DAVID. Candidate proteins were verified using Western blot and colocalization was investigated via immunofluorescence. Western blot and immunohistochemistry were used to detect protein expression in HCC tissues. Prognosis evaluation was conducted using Kaplan-Meier and Cox-proportional hazards regression analyses.Results: Our findings showed that cPLA2α knockdown decreases cell-matrix adhesion but increases cell-cell adhesion in HepG2 cells. Microarray analysis revealed that phosphorylation of multiple proteins at specific sites were regulated by cPLA2α. These phosphorylated proteins were involved in various biological processes. In addition, our results indicated that the focal adhesion pathway was highly enriched in the cPLA2α-relevant signaling pathway. Furthermore, cPLA2α was found to elevate phosphorylation levels of FAK and paxillin, two crucial components of focal adhesion. Moreover, localization of p-FAK to focal adhesions in the plasma membrane was significantly reduced with the downregulation of cPLA2α. Clinically, cPLA2α expression was positively correlated with p-FAK levels. Additionally, high expression of both cPLA2α and p-FAK predicted the worst prognoses for HCC patients.Conclusions: Our study indicated that cPLA2α may promote cell-matrix adhesion via the FAK/paxillin pathway, which partly explains the malignant cPLA2α phenotype seen in HCC.

Destabilization of acrosome and elastase influence mediate the release of secretory phospholipase A2 from human spermatozoa

Aim： To determine the cellular distribution of secretory phospholipase A2 （sPLA2） in dependence on the acrosomal state and under the action of elastase released under inflammatory processes from leukocytes. Methods： Acrosome reaction of spermatozoa was triggered by calcimycin. Human leukocyte elastase was used to simulate inflammatory conditions. To visualize the distribution of sPLA2 and to determine the acrosomal state, immunofluorescence techniques and lectin binding combined with confocal laser scanning fluorescence microscopy and flow cytometry were used. Results： Although sPLA2 was detected at the acrosome and tail regions in intact spermatozoa, it disappeared from the head region after triggering the acrosome reaction. This release of sPLA2 was associated with enhanced binding of annexin V-fluoroscein isothiocyanate （FITC） to spermatozoa surfaces, intercalation of ethidium-homodimer I, and binding of FITC-labelled concanavalin A at the acrosomal region. Spermatozoa from healthy subjects treated with elastase were characterized by release of sPLA2, disturbance of acrosome structure, and loss of vitality. Conclusion： The ability of spermatozoa to release secretory phospholipase A2 is related to the acrosomal state. Premature destabi- lization of the acrosome and loss of sPLA2 can occur during silent inflammations in the male genital tract. The distribution pattern of sPLA2 in intact spermatozoa might be an additional parameter for evaluating sperm quality.

Phospholipase C from Pseudomonas aeruginosa and Bacillus cereus:characterization of catalytic activity

Objective:To study characteristics of phospholipases C(PLCs),their importance for producing microorganisms us well us the potential of their use for industrial purposes.Methods:PLC from Bacillus cereus(B.cereus) D101 was selected as an example of Gram-positive PLCs and PLC from Pseudomanas aeruginosa(P.aeruginosa) D183 of Gram-negative ones.Enzymes were partially purified by ammonium sulfate precipitation followed by membrane dialysis.Partially purified preparations were used to study effect of different factors on activities as well as in substrate specificity tests which were conducted using a turbidimetric assay method.Results:Maximum activity was at pH 7 and 8 and 40 ℃ for P.aeruginosa PLC,and pH 8-10 and 37 ℃ for B.cereus PLC.Both PLCs were inhibited by Pi at 5 mM or higher,whereas,PLC from B.cereus only was inhibited by EDTA.Activity of P.aeruginosa PLC was not affected by removing Zn^(2+) ions from reaction mixture or their replacement with Ca^(2+),Ba^(2+),Mg^(2+) or Mn^(2+)ions.Vis-a-vis,activity of B.cereus PLC was found to be metal ion dependent PLCs from both isolates were relatively thermostable and showed maximum affinity toward phosphatidylcholine.Sphingomyelin and phosphatidylethanolamine were not good substrates and phosphatidylinositol,phosphatidylserine,phosphatidylglycerol and cardiolipin could be considered nonsubstrates.Conclusions:Human body physiological conditions could favor activity of P.aeruginosa and B.cereus PLCs.These enzymes may participate in phosphate scavenging and virulence of producing isolates but not in autolysis.PLCs from both isolates are potential candidates for industrial use.

The Use of Lipoprotein-Associated Phospholipase A2 in a Chinese Population to Predict Cardiovascular Events

Objective To explore associations between lipoprotein-associated phospholipase A2(Lp-PLA2)and the risk of cardiovascular events in a Chinese population,with a long-term follow-up.Methods A random sample of 2,031 participants(73.6%males,mean age=60.4 years)was derived from the Asymptomatic Polyvascular Abnormalities Community study(APAC)from 2010 to 2011.Serum Lp-PLA2 levels were determined by enzyme-linked immunosorbent assay(ELISA).The composite endpoint was a combination of first-ever stroke,myocardial infarction(MI)or all-cause death.Lp-PLA2 associations with outcomes were assessed using Cox models.Results The median Lp-PLA2 level was 141.0 ng/m L.Over a median follow-up of 9.1 years,we identified 389 events(19.2%),including 137 stroke incidents,43 MIs,and 244 all-cause deaths.Using multivariate Cox regression,when compared with the lowest Lp-PLA2 quartile,the hazard ratios with95%confidence intervals for developing composite endpoints,stroke,major adverse cardiovascular events,and all-cause death were 1.77(1.24–2.54),1.92(1.03–3.60),1.69(1.003–2.84),and 1.94(1.18–3.18)in the highest quartile,respectively.Composite endpoints in 145(28.6%)patients occurred in the highest quartile where Lp-PLA2(159.0 ng/m L)was much lower than the American Association of Clinical Endocrinologists recommended cut-off point,200 ng/m L.Conclusion Higher Lp-PLA2 levels were associated with an increased risk of cardiovascular event/death in a middle-aged Chinese population.The Lp-PLA2 cut-off point may be lower in the Chinese population when predicting cardiovascular events.

Patatin-like phospholipase domain containing-3 gene I148M polymorphism, steatosis, and liver damage in hereditary hemochromatosis

AIM： To investigate whether the patatin-/ike phosph- olipase domain containing-3 gene （PNPLA3） I148M polymorphism is associated with steatosis, fibrosis stage, and cirrhosis in hereditary hemochromatosis （HH）. METHODS： We studied 174 consecutive unrelated homozygous for the C282Y HFE mutation of HH （C282Y＋/＋ HH） patients from Northern Italy, for whom the presence of cirrhosis could be determined based on histological or clinical criteria, without excessive alcohol intake （〈 30/20 g/d in males or females） or hepatitis B virus and hepatitis C virus viral hepatitis. Steatosis was evaluated in 123 patients by histology （n = 100） or ul- trasound （n = 23）. The PNPLA3 rs738409 single nucle- otide polymorphism, encoding for the p.148M protein variant, was genotyped by a Taqman assay （assay on demand, Applied Biosystems）. The association of the PNPLA3 I148M protein variant （p.I148M） with steatosis, fibrosis stage, and cirrhosis was evaluated by logistic regression analysis. RESULTS： PNPLA3 genotype was not associated with metabolic parameters, including body mass index （BMI）, the presence of diabetes, and lipid levels, but the pres- ence of the p.148M variant at risk was independently associated with steatosis [odds ratio （OR） 1.84 per p.148M allele, 95% confidence interval （CI）： 1.05-3.31; P = 0.037], independently of BMI and alanine amino- transaminase （ALT） levels. The p.148M variant was also associated with higher aspartate aminotransferase （P = 0.0014） and ALT levels （P = 0.017） at diagnosis, independently of BMI and the severity of iron overload. In patients with liver biopsy, the 148M variant was independently associated with the severity （stage） of fibrosis （estimated coefficient 0.56 ± 0.27, P = 0.041）. In the overall series of patients, the p.148M variant was associated with cirrhosis in lean （P = 0.049）, but not in overweight patients （P = not significant）. At logistic regression analysis, cirrhosis was associated with BMI 〉~ 25 （OR 1.82, 95% CI： 1.02-3.55）, ferritin 〉 1000 ng/mL at diagnosis （OR 19.3, 95% CI： 5.3-125）, and with the G allele in patients with BMI 〈 25 （OR 3.26, 95% CI： 1.3-10.3）. CONCLUSION： The PNPLA3 I148M polymorphism may represent a permissive factor for fibrosis progression in patients with C282Y＋/＋ HH.

Oxidized phospholipids and lipoprotein-associated phospholipase A_2 as important determinants of Lp(a) functionality and pathophysiological role

Lipoprotein（a） [Lp（a）] is composed of a low density lipoprotein（LDL）-like particle to which apolipoprotein（a）[apo（a）] is linked by a single disulfide bridge. Lp（a） is considered a causal risk factor for ischemic cardiovascular disease（CVD） and calcific aortic valve stenosis（CAVS）. The evidence for a causal role of Lp（a） in CVD and CAVS is based on data from large epidemiological databases, mendelian randomization studies, and genome-wide association studies. Despite the well-established role of Lp（a） as a causal risk factor for CVD and CAVS, the underlying mechanisms are not well understood. A key role in the Lp（a） functionality may be played by its oxidized phospholipids（OxPL） content. Importantly, most of circulating OxPL are associated with Lp（a）; however, the underlying mechanisms leading to this preferential sequestration of OxPL on Lp（a） over the other lipoproteins,are mostly unknown. Several studies support the hypothesis that the risk of Lp（a） is primarily driven by its OxPL content.An important role in Lp（a） functionality may be played by the lipoprotein-associated phospholipase A_2（Lp-PLA_2）,an enzyme that catalyzes the degradation of OxPL and is bound to plasma lipoproteins including Lp（a）. The present review article discusses new data on the pathophysiological role of Lp（a） and particularly focuses on the functional role of OxPL and Lp-PLA_2 associated with Lp（a）.

Bromophenacyl bromide,a phospholipase A_2 inhibitor attenuates chemically induced gastroduodenal ulcers in rats

AIM: To study the effect of bromophenacyl bromide (BPB), a phospholipase A2 inhibitor on gastric secretion and to protect chemically induced gastric and duodenal ulcers in rats. METHODS: Acid secretion studies were undertaken in pylorus-ligated rats with BPB treatment (0, 5, 15 and 45 mg/kg). Gastric and duodenal lesions in the rats were induced by ethanol and cysteamine respectively. The levels of gastric wall mucus, nonprotein sulfhydryls (NP- SH) and myeloperoxidase (MPO) were also measured in the glandular stomach of rats following ethanol induced gastric lesions. RESULTS: BPB produced a dose-dependent inhibition of gastric acid secretion and acidity in rats. Pretreatment with BPB significantly attenuated the formation of etha- nol induced gastric lesion. BPB also protected intestinal mucosa against cysteamine-induced duodenal ulcers. The antiulcer activity of BPB was associated with signifi- cant inhibition of ethanol-induced depletion of gastric wall mucus, NP-SH and MPO. These findings pointed towards the mediation of sulfhydryls in BPB induced gas- trointestinal cytoprotection. CONCLUSION: BPB possesses significant antiulcer and cytoprotective activity against experimentally induced gastroduodenal lesions.

Linoleic Acid Activates GPR40/FFA1 and Phospholipase C to Increase [Ca^(2+)]_i Release and Insulin Secretion in Islet Beta-Cells

Objective To elucidate GPR40/FFA1 and its downstream signaling pathways in regulating insulin secretion. Methods GPR40/FFA1 expression was detected by immunofluorescence imaging. We employed linoleic acid (LA), a free fatty acid that has a high affinity to the rat GPR40, and examined its effect on cytosolic free calcium concentration ([Ca2+]i) in primary rat β-cells by Fluo-3 intensity under confocal microscopy recording. Downregulation of GPR40/FFA1 expression by antisense oligonucleotides was performed in pancreatic β-cells, and insulin secretion was assessed by enzyme-linked immunosorbent assay. Results LA acutely stimulated insulin secretion from primary cultured rat pancreatic islets. LA induced significant increase of [Ca2+]i in the presence of 5.6 mmol/L and 11.1 mmol/L glucose, which was reflected by increased Fluo-3 intensity under confocal microscopy recording. LA-stimulated increase in [Ca2+]i and insulin secretion were blocked by inhibition of GPR40/FFA1 expression in β-cells after GPR40/FFA1-specific antisense treatment. In addition, the inhibition of phospholipase C (PLC) activity by U73122, PLC inhibitor, also markedly inhibited the LA-induced [Ca2+]i increase. Conclusion LA activates GPR40/FFA1 and PLC to stimulate Ca2+ release, resulting in an increase in [Ca2+]i and insulin secretion in rat islet β-cells.

Lotus"Domain Formation by the Hydrolysis Reaction of Phospholipase D to Phospholipid Monolayer

Hydrolysis reaction of L-a-dipalmitoylphosphatidylcholine (L-DPPC) monolayer with phospholipase D (PLD) has been investigated by Brewster angle microscopy (BAM) combined with the film balance. It has been found that the L-DPPC domains were changed into the 搇otus?structure by PLD. It suggests that the hydrolysis reaction is incomplete and the products together with the nonreacted materials undergo a molecular rearrangement at the interface.