Osteoarthritis(OA) and intervertebral disc degeneration(IVDD) are degenerative musculoskeletal disorders characterized by degeneration of cartilaginous tissues and inflammation. While inflammation is implicated in the...Osteoarthritis(OA) and intervertebral disc degeneration(IVDD) are degenerative musculoskeletal disorders characterized by degeneration of cartilaginous tissues and inflammation. While inflammation is implicated in the pathogenesis of OA and IVDD, and cytosolic phospholipase A2(cPLA2) is a key mediator of inflammation, direct evidence linking cPLA2 to chondrocyte homeostasis and cartilage degeneration is lacking. This study aims to investigate the role of cPLA2 in chondrocytes and its contribution to the development of cartilage degenerative conditions such as OA and IVDD. Here, single-cell RNA sequencing was used to examine cPLA2 expression in chondrocytes. To explore its importance in chondrocytes and OA/IVDD, various cell-based assays and genetically modified mouse models with age-related and surgically induced OA/IVDD were employed. Furthermore, the therapeutic potential of fexofenadine, an over-the-counter drug recently identified as a cPLA2 inhibitor, was explored in these models. cPLA2 is predominantly expressed in prehypertrophic chondrocytes, characterized by elevated levels of cartilage degeneration markers and senescence-related genes. Genetic deletion and pharmacological inhibition of cPLA2 reduced inflammation induced catabolic activity and senescence in chondrocytes, as well as cartilage degeneration in various OA and IVDD models. This study identifies cPLA2 as a pivotal driver of cartilage degeneration and senescence in OA and IVDD, highlighting its potential as a dual-action therapeutic target that suppresses both inflammation and senescence to preserve cartilage integrity. These findings position cPLA2as a promising candidate for developing disease-modifying therapies for cartilage degenerative conditions such as OA and IVDD.展开更多
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 acu...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.展开更多
Acute pancreatitis(AP)remains a clinical challenge due to its heterogeneous presentation and potential for rapid progression to severe disease.In their editorial,Wang et al highlight phospholipase D2(PLD2)as a novel c...Acute pancreatitis(AP)remains a clinical challenge due to its heterogeneous presentation and potential for rapid progression to severe disease.In their editorial,Wang et al highlight phospholipase D2(PLD2)as a novel candidate biomarker,proposing its involvement in key inflammatory pathways and its inverse correlation with disease severity.While this represents a promising improvement in precision diagnostics,significant gaps remain that require further investigation.Specifically,the functional role of PLD2 in the molecular cascade of AP is not yet fully understood.Questions still remain,such as:Is the observed downregulation of PLD2 a causal factor or an epiphenomenon?Does PLD2 modulation offer a tangible therapeutic benefit beyond a mere correlation?These questions highlight the necessity of mechanistic in vivo studies to validate the role and therapeutic potential of PLD2.Furthermore,interindividual variability in inflammatory responses raises concerns regarding PLD2’s predictive consistency across genetically diverse populations.The temporal dynamics of PLD2 expression in AP also remain unclear;establishing whether its variations precede clinical deterioration is essential for its use in early risk stratification,integrating multiomics research(proteomics,metabolomics,transcriptomics,and lipidomics),which can clarify the biological interactions and regulatory pathways of PLD2 under complex mechanisms.Likewise,well-designed,multicenter,prospective studies will be essential in determining its true clinical value.The research by Wang et al initiates an intriguing direction in the quest for AP biomarkers,but further research is required before PLD2 can be established as a clinically applicable tool.Additional efforts are required to close this gap and define whether its role transcends a mere association in order for it to become a therapeutic target.展开更多
In this editorial,we critically evaluate the recent article by Niu et al,which ex-plores the potential of phospholipase D2(PLD2)as a biomarker for stratifying disease severity in acute pancreatitis(AP).AP is a clinica...In this editorial,we critically evaluate the recent article by Niu et al,which ex-plores the potential of phospholipase D2(PLD2)as a biomarker for stratifying disease severity in acute pancreatitis(AP).AP is a clinically heterogeneous inflam-matory condition that requires reliable biomarkers for early and accurate classi-fication of disease severity.PLD2,an essential regulator of neutrophil migration and inflammatory responses,has emerged as a promising candidate.Although current biomarkers such as C-reactive protein and procalcitonin provide general indications of inflammation,they lack specificity regarding the molecular mechanisms underlying AP progression.Recent studies,including the research conducted by Niu et al,suggest an inverse correlation between PLD2 expression and AP severity,offering both diagnostic insights and mechanistic understanding.This editorial critically evaluates the role of PLD2 as a biomarker in the broader context of AP research.Evidence indicates that decreased levels of PLD2 are associated with increased neutrophil chemotaxis and cytokine release,con-tributing to pancreatic and systemic inflammation.However,several challenges remain,including the need for large-scale validation and functional studies to establish causation,and standardization of measurement protocols.Additionally,further investigation into the temporal dynamics of PLD2 expression and its variability across diverse populations is warranted.Looking ahead,PLD2 holds the potential to revolutionize AP management by integrating molecular diagnostics with precision medicine.The utilization of large-scale multi-omics approaches and advancements in diagnostic platforms could position PLD2 as a fundamental biomarker for early diagnosis,prognosis,and potentially therapeutic targeting.While promising,it is crucial to conduct critical evaluations and rigorous validations of PLD2’s role to ensure its efficacy in improving patient outcomes.展开更多
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 dest...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.展开更多
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 random...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.展开更多
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 parti...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.展开更多
This study was to investigate the responses of phospholipase D（PLD） and lipoxygenase（LOX） to mechanical wounding in postharvest cucumber（Cucumis sativus L.cv.Biyu-2） fruits.Membrane-associated Ca2＋ content,acti...This study was to investigate the responses of phospholipase D（PLD） and lipoxygenase（LOX） to mechanical wounding in postharvest cucumber（Cucumis sativus L.cv.Biyu-2） fruits.Membrane-associated Ca2＋ content,activities and gene expression of PLD and LOX,and contents of phosphatidylcholine（PC）,phosphatidylinositol（PI）,and phosphatidic acid（PA） were determined in cucumber fruits following mechanical wounding.Results show that PLD and LOX activities increased with the PLD and LOX mRNAs which are upregulated upon wounding,while membrane-associated Ca^2＋ content decreased.Accompanying with the increase of PLD and LOX activities,accumulation of PA and losses of PC and PI were observed in all fruits,but there were differences of degrees between wounded and control fruits.Results suggest that PLD and LOX might be the main hydrolytic enzymes of phospholipids in postharvest cucumber fruits participating in the mechanical wounding injury.The activation of PLD and LOX might be the result of gene expression,which could be This study was to investigate the responses of phospholipase D（PLD） and lipoxygenase（LOX） to mechanical wounding in postharvest cucumber（Cucumis sativus L.cv.Biyu-2） fruits.Membrane-associated Ca^2＋ content,activities and gene expression of PLD and LOX,and contents of phosphatidylcholine（PC）,phosphatidylinositol（PI）,and phosphatidic acid（PA） were determined in cucumber fruits following mechanical wounding.Results show that PLD and LOX activities increased with the PLD and LOX mRNAs which are upregulated upon wounding,while membrane-associated Ca2＋ content decreased.Accompanying with the increase of PLD and LOX activities,accumulation of PA and losses of PC and PI were observed in all fruits,but there were differences of degrees between wounded and control fruits.Results suggest that PLD and LOX might be the main hydrolytic enzymes of phospholipids in postharvest cucumber fruits participating in the mechanical wounding injury.The activation of PLD and LOX might be the result of gene expression,which could be stimulated by the Ca^2＋ flowing from the membrane to the cytoplasm upon receiving the wounding signals.展开更多
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）. ME...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.展开更多
The phosphatidylserine-specific phospholipase A1(PLA1A)is an essential host factor in hepatitis C virus(HCV)assembly.In this study,we mapped the E2,NS2 and NS5A involved in PLA1A interaction to their lumenal domains a...The phosphatidylserine-specific phospholipase A1(PLA1A)is an essential host factor in hepatitis C virus(HCV)assembly.In this study,we mapped the E2,NS2 and NS5A involved in PLA1A interaction to their lumenal domains and membranous parts,through which they form oligomeric protein complexes to participate in HCV assembly.Multiple regions of PLA1A were involved in their interaction and complex formation.Furthermore,the results represented structures with PLA1A and E2 in closer proximity than NS2 and NS5A,and strongly suggest PLA1 A-E2,s physical interaction in cells.Meanwhile,we mapped the NS5A sequence which participated in PLA1A interaction with the C-terminus of domain 1.Interestingly,these amino acids in the sequence are also essential for viral RNA replication.Further experiments revealed that these four proteins interact with each other.Moreover,PLA1A expression levels were elevated in livers from HCV-infected patients.In conclusion,we exposed the structural determinants of PLA1A,E2,NS2 and NS5A proteins which were important for HCV assembly and provided a detailed characterization of PLA1A in HCV assembly.展开更多
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 u...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.展开更多
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 un...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.展开更多
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...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.展开更多
Central nervous system(CNS)trauma,including traumatic brain injury and spinal cord injury,has a high rate of disability and mortality,and effective treatment is currently lacking.Previous studies have revealed that ne...Central nervous system(CNS)trauma,including traumatic brain injury and spinal cord injury,has a high rate of disability and mortality,and effective treatment is currently lacking.Previous studies have revealed that neural inflammation plays a vital role in CNS trauma.As the initial enzyme in neuroinflammation,cytosolic phospholipase A_(2)(cPLA2)can hydrolyze membranous phosphatides at the sn-2 position in a preferential way to release lysophospholipids andω3-polyunsaturated fatty acid dominated by arachidonic acid,thereby inducing secondary injuries.Although there is substantial fresh knowledge pertaining to cPLA2,in-depth comprehension of how cPLA2 participates in CNS trauma and the potential methods to amelio rate the clinical res ults after CNS trauma are still insufficient.The present review summarizes the latest understanding of how cPLA2 participates in CNS trauma,highlighting novel findings pertaining to how cPLA2 activation initiates the potential mechanisms specifically,neuroinflammation,lysosome membrane functions,and autophagy activity,that damage the CNS after trauma.Moreover,we focused on testing a variety of drugs capable of inhibiting cPLA2 or the upstream pathway,and we explored how those agents might be utilized as treatments to improve the results following CNS trauma.This review aimed to effectively understand the mechanism of cPLA2 activation and its role in the pathophysiological processes of CNS trauma and provide clarification and a new referential framework for future research.展开更多
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 combina...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.展开更多
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...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.展开更多
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 ...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.展开更多
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 is...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）.展开更多
OBJECTIVE:To determine whether moxibustion had an anti-inflammatory effect on rheumatoid arthritis(RA)by regulating Annexin 1 expression and interfering with the phospholipaseA2 signaling pathway.METHODS:Thirty male S...OBJECTIVE:To determine whether moxibustion had an anti-inflammatory effect on rheumatoid arthritis(RA)by regulating Annexin 1 expression and interfering with the phospholipaseA2 signaling pathway.METHODS:Thirty male Sprague-Dawley rats were randomly categorized into five groups(six rats per group):blank control(CON)group,RA model(RA)group,moxibustion(MOX)group,Annexin 1 lentiviral intervention(RNAi-Anxa1)group,and Annexin 1 lentiviral intervention+moxibustion(RNAi-Anxa1+MOX)group.The rats in the RNAi-Anxa1 and the RNAi-Anxa1+MOX groups were injected with the lentiviral vector-mediated RNAi-Anxa1 into the rat foot pad.An experimental RA rat model was established by injecting Freund's complete adjuvant(FCA)into the RA,MOX,RNAi-Anxa1,and RNAi-Anxa1+MOX groups.Rats in the MOX and RNAiAnxa1+MOX groups received moxibustion treatment.After modeling,using moxibustion“Shenshu(BL23)”and“Zusanli(ST36)”,each point is 5 times,bilateral alternating,once a day,6 times for a course of treatment,between the courses of rest for a one day.A total of three treatment courses were conducted.Both bilateral pad thicknesses were measured using Vernier calipers on experimental days 1,7,14,21,and 28.The expression of cPLA2αsignaling in the synovium of diseased joints was observed using Western blot.The pathology of the rat ankle synovium was observed using hematoxylineosin(HE)staining.Interleukin(IL)-1β,IL-10,prostaglandin E2(PGE2),and leukotriene B4(LTB4)were detected using enzyme-linked immunosorbent assay.RESULTS:Moxibustion increased the levels of Annexin 1 and decreased the inflammatory response in rats with RA.After increasing the expression of Annexin 1,the phosphorylated expression of cPLA2αwas inhibited,the serum levels of IL-1β,PGE2,and LTB4 decreased,and the level of IL-10 increased.In moxibustion treated RA rats after the Annexin 1 lentiviral intervention,the serum levels of IL-1β,PGE2,LTB4,and IL-10 were almost unchanged.CONCLUSION:Moxibustion enhanced the negative regulation of the cPLA2αsignaling pathway,increased the synovial Annexin 1 expression,inhibited the cPLA2αsignaling pathway,indirectly inhibited the expression of downstream inflammatory factors,and played a role in reducing inflammation.展开更多
Cytosolic phospholipase A2α （cPLA2α） catalyzes the release of arachidonic acid （AA） and lysophosphoglyceride from membrane phospholipids. Although the roles of AA and eicosanoids in cellular viability, the proce...Cytosolic phospholipase A2α （cPLA2α） catalyzes the release of arachidonic acid （AA） and lysophosphoglyceride from membrane phospholipids. Although the roles of AA and eicosanoids in cellular viability, the processes of inflammation and cancer cell development have been extensively studied, the function of cPLA2α in the processes of inflammation and cancer cell development is not clear. This review summarizes published evidences for the biochemical properties and regulatory mechanisms of cPLA2α. The potential for use of cPLA2α as a novel diagnostic target and predictive biomarker for tumors is also discussed.展开更多
基金supported partly by NIH research grants R01AR078035, R01AR062207,R01AR076900 and R01NS070328。
文摘Osteoarthritis(OA) and intervertebral disc degeneration(IVDD) are degenerative musculoskeletal disorders characterized by degeneration of cartilaginous tissues and inflammation. While inflammation is implicated in the pathogenesis of OA and IVDD, and cytosolic phospholipase A2(cPLA2) is a key mediator of inflammation, direct evidence linking cPLA2 to chondrocyte homeostasis and cartilage degeneration is lacking. This study aims to investigate the role of cPLA2 in chondrocytes and its contribution to the development of cartilage degenerative conditions such as OA and IVDD. Here, single-cell RNA sequencing was used to examine cPLA2 expression in chondrocytes. To explore its importance in chondrocytes and OA/IVDD, various cell-based assays and genetically modified mouse models with age-related and surgically induced OA/IVDD were employed. Furthermore, the therapeutic potential of fexofenadine, an over-the-counter drug recently identified as a cPLA2 inhibitor, was explored in these models. cPLA2 is predominantly expressed in prehypertrophic chondrocytes, characterized by elevated levels of cartilage degeneration markers and senescence-related genes. Genetic deletion and pharmacological inhibition of cPLA2 reduced inflammation induced catabolic activity and senescence in chondrocytes, as well as cartilage degeneration in various OA and IVDD models. This study identifies cPLA2 as a pivotal driver of cartilage degeneration and senescence in OA and IVDD, highlighting its potential as a dual-action therapeutic target that suppresses both inflammation and senescence to preserve cartilage integrity. These findings position cPLA2as a promising candidate for developing disease-modifying therapies for cartilage degenerative conditions such as OA and IVDD.
文摘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.
基金Supported by Mexican Association of Gastroenterology 2023 for the scholarship warded.
文摘Acute pancreatitis(AP)remains a clinical challenge due to its heterogeneous presentation and potential for rapid progression to severe disease.In their editorial,Wang et al highlight phospholipase D2(PLD2)as a novel candidate biomarker,proposing its involvement in key inflammatory pathways and its inverse correlation with disease severity.While this represents a promising improvement in precision diagnostics,significant gaps remain that require further investigation.Specifically,the functional role of PLD2 in the molecular cascade of AP is not yet fully understood.Questions still remain,such as:Is the observed downregulation of PLD2 a causal factor or an epiphenomenon?Does PLD2 modulation offer a tangible therapeutic benefit beyond a mere correlation?These questions highlight the necessity of mechanistic in vivo studies to validate the role and therapeutic potential of PLD2.Furthermore,interindividual variability in inflammatory responses raises concerns regarding PLD2’s predictive consistency across genetically diverse populations.The temporal dynamics of PLD2 expression in AP also remain unclear;establishing whether its variations precede clinical deterioration is essential for its use in early risk stratification,integrating multiomics research(proteomics,metabolomics,transcriptomics,and lipidomics),which can clarify the biological interactions and regulatory pathways of PLD2 under complex mechanisms.Likewise,well-designed,multicenter,prospective studies will be essential in determining its true clinical value.The research by Wang et al initiates an intriguing direction in the quest for AP biomarkers,but further research is required before PLD2 can be established as a clinically applicable tool.Additional efforts are required to close this gap and define whether its role transcends a mere association in order for it to become a therapeutic target.
基金Supported by National Natural Sciences Foundation of China,No.82301700Liaoning Province Natural Science Foundation Project,No.2024-MS-157+2 种基金Youth Talent Cultivation Fund Key Project of Dalian Medical UniversityScientific Research Projects from Wuhan Municipal Health Commission,No.WX23Z26Science and Technology of Liaoning Province,No.2023-MS-266.
文摘In this editorial,we critically evaluate the recent article by Niu et al,which ex-plores the potential of phospholipase D2(PLD2)as a biomarker for stratifying disease severity in acute pancreatitis(AP).AP is a clinically heterogeneous inflam-matory condition that requires reliable biomarkers for early and accurate classi-fication of disease severity.PLD2,an essential regulator of neutrophil migration and inflammatory responses,has emerged as a promising candidate.Although current biomarkers such as C-reactive protein and procalcitonin provide general indications of inflammation,they lack specificity regarding the molecular mechanisms underlying AP progression.Recent studies,including the research conducted by Niu et al,suggest an inverse correlation between PLD2 expression and AP severity,offering both diagnostic insights and mechanistic understanding.This editorial critically evaluates the role of PLD2 as a biomarker in the broader context of AP research.Evidence indicates that decreased levels of PLD2 are associated with increased neutrophil chemotaxis and cytokine release,con-tributing to pancreatic and systemic inflammation.However,several challenges remain,including the need for large-scale validation and functional studies to establish causation,and standardization of measurement protocols.Additionally,further investigation into the temporal dynamics of PLD2 expression and its variability across diverse populations is warranted.Looking ahead,PLD2 holds the potential to revolutionize AP management by integrating molecular diagnostics with precision medicine.The utilization of large-scale multi-omics approaches and advancements in diagnostic platforms could position PLD2 as a fundamental biomarker for early diagnosis,prognosis,and potentially therapeutic targeting.While promising,it is crucial to conduct critical evaluations and rigorous validations of PLD2’s role to ensure its efficacy in improving patient outcomes.
基金Supported by FORICA(the FOundation for Advanced Research in Hypertension and Cardiovascular diseases,www.forica.it)
文摘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.
基金Supported by the Traditional Chinese Medicine Administration Bureau Foundation of Jiangsu Province,No.9965the Applied Basic Research Program of Science and Technology Commission Foundation of Jiangsu Province,No.BJ2000327
文摘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.
基金supported by the National Natural Science Foundation of China [Grant No. 81973112 and Grant No.9204930002]
文摘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.
基金Project (No.30771513) supported by the National Natural Science Foundation of China
文摘This study was to investigate the responses of phospholipase D（PLD） and lipoxygenase（LOX） to mechanical wounding in postharvest cucumber（Cucumis sativus L.cv.Biyu-2） fruits.Membrane-associated Ca2＋ content,activities and gene expression of PLD and LOX,and contents of phosphatidylcholine（PC）,phosphatidylinositol（PI）,and phosphatidic acid（PA） were determined in cucumber fruits following mechanical wounding.Results show that PLD and LOX activities increased with the PLD and LOX mRNAs which are upregulated upon wounding,while membrane-associated Ca^2＋ content decreased.Accompanying with the increase of PLD and LOX activities,accumulation of PA and losses of PC and PI were observed in all fruits,but there were differences of degrees between wounded and control fruits.Results suggest that PLD and LOX might be the main hydrolytic enzymes of phospholipids in postharvest cucumber fruits participating in the mechanical wounding injury.The activation of PLD and LOX might be the result of gene expression,which could be This study was to investigate the responses of phospholipase D（PLD） and lipoxygenase（LOX） to mechanical wounding in postharvest cucumber（Cucumis sativus L.cv.Biyu-2） fruits.Membrane-associated Ca^2＋ content,activities and gene expression of PLD and LOX,and contents of phosphatidylcholine（PC）,phosphatidylinositol（PI）,and phosphatidic acid（PA） were determined in cucumber fruits following mechanical wounding.Results show that PLD and LOX activities increased with the PLD and LOX mRNAs which are upregulated upon wounding,while membrane-associated Ca2＋ content decreased.Accompanying with the increase of PLD and LOX activities,accumulation of PA and losses of PC and PI were observed in all fruits,but there were differences of degrees between wounded and control fruits.Results suggest that PLD and LOX might be the main hydrolytic enzymes of phospholipids in postharvest cucumber fruits participating in the mechanical wounding injury.The activation of PLD and LOX might be the result of gene expression,which could be stimulated by the Ca^2＋ flowing from the membrane to the cytoplasm upon receiving the wounding signals.
基金Supported by FIRST Università degli Studi di Milano 2007,2008 to Valenti L, Fargion SRicerca corrente Ospedale Maggiore Policlinico 2006 and 2008 to Valenti L, Fargion SCentro per lo Studio delle Malattie del Fegato e del Metabolismo
文摘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.
基金supported by grants of the National Basic Research Priorities Program of China (2015CB554304)
文摘The phosphatidylserine-specific phospholipase A1(PLA1A)is an essential host factor in hepatitis C virus(HCV)assembly.In this study,we mapped the E2,NS2 and NS5A involved in PLA1A interaction to their lumenal domains and membranous parts,through which they form oligomeric protein complexes to participate in HCV assembly.Multiple regions of PLA1A were involved in their interaction and complex formation.Furthermore,the results represented structures with PLA1A and E2 in closer proximity than NS2 and NS5A,and strongly suggest PLA1 A-E2,s physical interaction in cells.Meanwhile,we mapped the NS5A sequence which participated in PLA1A interaction with the C-terminus of domain 1.Interestingly,these amino acids in the sequence are also essential for viral RNA replication.Further experiments revealed that these four proteins interact with each other.Moreover,PLA1A expression levels were elevated in livers from HCV-infected patients.In conclusion,we exposed the structural determinants of PLA1A,E2,NS2 and NS5A proteins which were important for HCV assembly and provided a detailed characterization of PLA1A in HCV assembly.
基金This work was supported by grants from Key Project of Tianjin Natural Science Foundation (Grant No.18JCZDJC35200)NSFC-FRQS program (Grant No.81661128009)+1 种基金The Science & Technology Development Fund of Tianjin Education Commission for Higher Education (Grant No.2017KJ202)Scientific Research Foundation for Returned Scholars and Doctoral Program of Tianjin Medical University Cancer Institute and Hospital (Grant No.B1703)
文摘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.
文摘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.
文摘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.
基金supported by the National Natural Science Foundation of China,No.82072192(to KLZ)Public Welfare Technology Research Project of Zhejiang Province,No.LGF20H150003(to KLZ)+1 种基金the Natural Science Foundation of Zhejiang Province,Nos.LY17H060009 and Y21H060050(both to WFN)Wenzhou Science and Technology Bureau Foundation,No.Y20210438(to KLZ)。
文摘Central nervous system(CNS)trauma,including traumatic brain injury and spinal cord injury,has a high rate of disability and mortality,and effective treatment is currently lacking.Previous studies have revealed that neural inflammation plays a vital role in CNS trauma.As the initial enzyme in neuroinflammation,cytosolic phospholipase A_(2)(cPLA2)can hydrolyze membranous phosphatides at the sn-2 position in a preferential way to release lysophospholipids andω3-polyunsaturated fatty acid dominated by arachidonic acid,thereby inducing secondary injuries.Although there is substantial fresh knowledge pertaining to cPLA2,in-depth comprehension of how cPLA2 participates in CNS trauma and the potential methods to amelio rate the clinical res ults after CNS trauma are still insufficient.The present review summarizes the latest understanding of how cPLA2 participates in CNS trauma,highlighting novel findings pertaining to how cPLA2 activation initiates the potential mechanisms specifically,neuroinflammation,lysosome membrane functions,and autophagy activity,that damage the CNS after trauma.Moreover,we focused on testing a variety of drugs capable of inhibiting cPLA2 or the upstream pathway,and we explored how those agents might be utilized as treatments to improve the results following CNS trauma.This review aimed to effectively understand the mechanism of cPLA2 activation and its role in the pathophysiological processes of CNS trauma and provide clarification and a new referential framework for future research.
基金supported by China Post doctoral Science Foundation (20070420095)the National Natural Science Foundation of China (30571279,30871699,30901012)+1 种基金Innovative Foundation of Shanghai UniversitySystems Biology Research Foundation of Shanghai University
文摘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.
基金Supported by Grant from Department of Education of Liaoning Province (2008810)
文摘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.
文摘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.
文摘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）.
基金Grants from the National Natural Science Foundation of China:Study on the Immune Mechanism of Macrophages 1/Macrophages 2 Polarization of Macrophages Treated with Moxibustion"Strengthening the Body and Expelling Pathogenic Qi"for"Struggle Between Healthy Qi and Pathogenic Qi"in Rheumatoid Arthritis(No.81973959)the National Key R&D Program of China:a Comparative Study of Moxibustion at Zusanli(ST36)on the Polarization of Knee Synovial Macrophage in Kneeosteoar-thritis and Rheumatoid Arthritis Rat Models(No.2019YFC1709001)+2 种基金the National Natural Science Foundation of China:Study on the Regulatory Mechanism of the"Immune-Inflammation"Molecular Signal of the Nucleotide—Binding Oligomerization Domain,Leucine rich Repeat and Pyrin domain containing Proteins 3 Inflammasome Treated by Moxibustion for Rheumatoid Arthritis(No.81774435)the Foundation of Chengdu University of Traditional Chinese Medicine:Study on the Mechanism of"Macrophage Migration Inhibitory Factor-Target Protein-Glucocorticoid-Inflammation"in Moxibustion Treatment and Anti-inflammatory Effect of Rheumatoid Arthritis(No.QNXZ2018034)the Science and Technology Innovation Seedling Project of Sichuan Province:Exploring the Effector Mechanism of Moxibustion Treatment in the Experimental Rheumatoid Arthritis Model based on the Macrophage Macrophages 1 Polarization Signaling Pathway Toll-like Receptors 4-Maximum Tolerated Dose 88-Nuclear Factor-Kappa B and its Regulatory Molecule T Cell Immunoglobulin and Mucin Domain-containing Protein 3(No.2022037)。
文摘OBJECTIVE:To determine whether moxibustion had an anti-inflammatory effect on rheumatoid arthritis(RA)by regulating Annexin 1 expression and interfering with the phospholipaseA2 signaling pathway.METHODS:Thirty male Sprague-Dawley rats were randomly categorized into five groups(six rats per group):blank control(CON)group,RA model(RA)group,moxibustion(MOX)group,Annexin 1 lentiviral intervention(RNAi-Anxa1)group,and Annexin 1 lentiviral intervention+moxibustion(RNAi-Anxa1+MOX)group.The rats in the RNAi-Anxa1 and the RNAi-Anxa1+MOX groups were injected with the lentiviral vector-mediated RNAi-Anxa1 into the rat foot pad.An experimental RA rat model was established by injecting Freund's complete adjuvant(FCA)into the RA,MOX,RNAi-Anxa1,and RNAi-Anxa1+MOX groups.Rats in the MOX and RNAiAnxa1+MOX groups received moxibustion treatment.After modeling,using moxibustion“Shenshu(BL23)”and“Zusanli(ST36)”,each point is 5 times,bilateral alternating,once a day,6 times for a course of treatment,between the courses of rest for a one day.A total of three treatment courses were conducted.Both bilateral pad thicknesses were measured using Vernier calipers on experimental days 1,7,14,21,and 28.The expression of cPLA2αsignaling in the synovium of diseased joints was observed using Western blot.The pathology of the rat ankle synovium was observed using hematoxylineosin(HE)staining.Interleukin(IL)-1β,IL-10,prostaglandin E2(PGE2),and leukotriene B4(LTB4)were detected using enzyme-linked immunosorbent assay.RESULTS:Moxibustion increased the levels of Annexin 1 and decreased the inflammatory response in rats with RA.After increasing the expression of Annexin 1,the phosphorylated expression of cPLA2αwas inhibited,the serum levels of IL-1β,PGE2,and LTB4 decreased,and the level of IL-10 increased.In moxibustion treated RA rats after the Annexin 1 lentiviral intervention,the serum levels of IL-1β,PGE2,LTB4,and IL-10 were almost unchanged.CONCLUSION:Moxibustion enhanced the negative regulation of the cPLA2αsignaling pathway,increased the synovial Annexin 1 expression,inhibited the cPLA2αsignaling pathway,indirectly inhibited the expression of downstream inflammatory factors,and played a role in reducing inflammation.
文摘Cytosolic phospholipase A2α （cPLA2α） catalyzes the release of arachidonic acid （AA） and lysophosphoglyceride from membrane phospholipids. Although the roles of AA and eicosanoids in cellular viability, the processes of inflammation and cancer cell development have been extensively studied, the function of cPLA2α in the processes of inflammation and cancer cell development is not clear. This review summarizes published evidences for the biochemical properties and regulatory mechanisms of cPLA2α. The potential for use of cPLA2α as a novel diagnostic target and predictive biomarker for tumors is also discussed.
