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Andrologia Feb 2022In mammals, 'oocyte activation' is triggered by certain proteins, one of which is phospholipase C-zeta. Recent evidence suggests that low expression of phospholipase...
In mammals, 'oocyte activation' is triggered by certain proteins, one of which is phospholipase C-zeta. Recent evidence suggests that low expression of phospholipase C-zeta might be associated with male infertility, while a limited number of studies claimed the opposite. This study was designed to test whether quantity of phospholipase C-zeta and in vitro fertilisation rates are correlated or not, assessed by flow cytometry. Semen samples from 43 infertile couples were analysed for the percentage and mean fluorescent intensity (MFI) of phospholipase C-zeta protein. Results were confirmed by immunofluorescent labelling. Patients with a fertilisation rate of 40% or lower were involved in the low fertilisation group, while the high fertilization group consisted of patients with a fertilisation rate of 60% and higher. Quantitative analyses by flow cytometry showed no significant difference among the low fertilisation and high fertilisation groups when phospholipase C-zeta ratio or MFI was considered. No correlation was found between pregnancy rates and phospholipase C-zeta quantity. None of the total fertilisation failure cases were lack of phospholipase C-zeta. In fact, fertilisation was possible even when phospholipase C-zeta levels were very low. Thus, we concluded that phospholipase C-zeta quantity cannot be considered as a diagnostic tool for male infertility.
Topics: Female; Fertilization; Humans; Infertility, Male; Male; Pregnancy; Pregnancy Rate; Spermatozoa; Type C Phospholipases
PubMed: 34651330
DOI: 10.1111/and.14269 -
American Journal of Physiology. Lung... Jul 2020Secreted phospholipase A hydrolyzes surfactant phospholipids and is crucial for the inflammatory cascade; preterm neonates are treated with exogenous surfactant, but the...
Secreted phospholipase A hydrolyzes surfactant phospholipids and is crucial for the inflammatory cascade; preterm neonates are treated with exogenous surfactant, but the interaction between surfactant and phospholipase is unknown. We hypothesize that this interplay is complex and the enzyme plays a relevant role in neonates needing surfactant replacement. We aimed to: ) identify phospholipases A isoforms expressed in preterm lung; ) study the enzyme role on surfactant retreatment and function and the effect of exogenous surfactant on the enzyme system; and ) verify whether phospholipase A is linked to respiratory outcomes. In bronchoalveolar lavages of preterm neonates, we measured enzyme activity (alone or with inhibitors), enzyme subtypes, surfactant protein-A, and inflammatory mediators. Surfactant function and phospholipid profile were also tested. Urea ratio was used to obtain epithelial lining fluid concentrations. Follow-up data were prospectively collected. Subtype-IIA is the main phospholipase isoform in preterm lung, although subtype-IB may be significantly expressed. Neonates needing surfactant retreatment have higher enzyme activity ( = 0.021) and inflammatory mediators ( always ≤ 0.001) and lower amounts of phospholipids ( always < 0.05). Enzyme activity was inversely correlated to surfactant adsorption (ρ = -0.6; = 0.008; adjusted = 0.009), total phospholipids (ρ = -0.475; = 0.05), and phosphatidylcholine (ρ = -0.622; = 0.017). Exogenous surfactant significantly reduced global phospholipase activity ( < 0.001) and subtype-IIA ( = 0.005) and increased dioleoylphosphatidylglycerol ( < 0.001) and surfactant adsorption ( < 0.001). Enzyme activity correlated with duration of ventilation (ρ = 0.679, = 0.005; adjusted = 0.04) and respiratory morbidity score at 12 mo postnatal age (τ = 0.349, = 0.037; adjusted = 0.043) but was not associated with mortality, bronchopulmonary dysplasia, or other long-term respiratory outcomes.
Topics: Bronchoalveolar Lavage Fluid; Epithelial Cells; Female; Humans; Infant, Newborn; Infant, Premature; Male; Phospholipases A2, Secretory; Phospholipids; Pulmonary Surfactants; Respiration
PubMed: 32401671
DOI: 10.1152/ajplung.00462.2019 -
EBioMedicine Feb 2021Schizophrenia (SZ) is a severe mental disease with highly heterogeneous clinical manifestations and pathological mechanisms. Schizophrenia is linked to abnormalities in...
BACKGROUND
Schizophrenia (SZ) is a severe mental disease with highly heterogeneous clinical manifestations and pathological mechanisms. Schizophrenia is linked to abnormalities in cell membrane phospholipids and blunting of the niacin skin flush response, but the associations between these phenotypes and its molecular pathogenesis remain unclear. This study aimed to describe the PLA2/COX pathway, the key link between phospholipids and niacin flush, and to illustrate the pathogenic mechanisms in schizophrenia that mediate the above phenotypes.
METHODS
A total of 166 patients with schizophrenia and 54 healthy controls were recruited in this study and assigned to a discovery set and a validation set. We assessed the mRNA levels of 19 genes related to the PLA2/COX cascade in leukocytes by real-time PCR. Plasma IL-6 levels were measured with an ELISA kit. Genetic association analysis was performed on PLA2G4A and PTGS2 to investigate their potential relationship with blunted niacin-skin response in an independent sample set.
FINDINGS
Six of the 19 genes in the PLA2/COX pathway exhibited significant differences between schizophrenia and healthy controls. The disturbance of the pathway indicates the activation of arachidonic acid (AA) hydrolysis and metabolization, resulting in the abnormalities of membrane lipid homeostasis and immune function, further increasing the risk of schizophrenia. On the other hand, the active process of AA hydrolysis from cell membrane phospholipids and decreased transcription of CREB1, COX-2 and PTGER4 may explain the reported findings of a blunted niacin response in schizophrenia. The significant genetic associations between PLA2G4A and PTGS2 with the niacin-skin responses further support the inference.
INTERPRETATION
These results suggested that the activation of AA hydrolysis and the imbalance in COX-1 and COX-2 expression are involved in the pathogenesis of schizophrenia and blunting of the niacin flush response.
FUNDING
This work was supported by the National Key R&D Program of China (2016YFC1306900, 2016YFC1306802); the National Natural Science Foundation of China (81971254, 81771440, 81901354); Interdisciplinary Program of Shanghai Jiao Tong University (ZH2018ZDA40, YG2019GD04, YG2016MS48); Grants of Shanghai Brain-Intelligence Project from STCSM (16JC1420500); Shanghai Key Laboratory of Psychotic Disorders (13DZ2260500); and Shanghai Municipal Science and Technology Major Project (2017SHZDZX01); China Postdoctoral Science Foundation (2018M642029, 2018M630442, 2019M661526, 2020T130407); Natural Science Foundation of Shanghai (20ZR1426700); and Startup Fund for Youngman Research at SJTU (19 × 100040033).
Topics: Adult; Biomarkers; Case-Control Studies; Cyclooxygenase 2; Cytokines; Disease Susceptibility; Female; Gene Expression Regulation; Humans; Male; Middle Aged; Models, Biological; Phospholipases; Prostaglandin-Endoperoxide Synthases; Schizophrenia; Young Adult
PubMed: 33581645
DOI: 10.1016/j.ebiom.2021.103239 -
The EMBO Journal Sep 2022The Arf GTPase family is involved in a wide range of cellular regulation including membrane trafficking and organelle-structure assembly. Here, we have generated a...
The Arf GTPase family is involved in a wide range of cellular regulation including membrane trafficking and organelle-structure assembly. Here, we have generated a proximity interaction network for the Arf family using the miniTurboID approach combined with TMT-based quantitative mass spectrometry. Our interactome confirmed known interactions and identified many novel interactors that provide leads for defining Arf pathway cell biological functions. We explored the unexpected finding that phospholipase D1 (PLD1) preferentially interacts with two closely related but poorly studied Arf family GTPases, ARL11 and ARL14, showing that PLD1 is activated by ARL11/14 and may recruit these GTPases to membrane vesicles, and that PLD1 and ARL11 collaborate to promote macrophage phagocytosis. Moreover, ARL5A and ARL5B were found to interact with and recruit phosphatidylinositol 4-kinase beta (PI4KB) at trans-Golgi, thus promoting PI4KB's function in PI4P synthesis and protein secretion.
Topics: 1-Phosphatidylinositol 4-Kinase; GTP Phosphohydrolases; Golgi Apparatus; Phospholipase D
PubMed: 35844135
DOI: 10.15252/embj.2022110698 -
Biomolecules May 2023Phospholipases are essential intermediaries that work as hydrolyzing enzymes of phospholipids (PLs), which represent the most abundant species contributing to the... (Review)
Review
Phospholipases are essential intermediaries that work as hydrolyzing enzymes of phospholipids (PLs), which represent the most abundant species contributing to the biological membranes of nervous cells of the healthy human brain. They generate different lipid mediators, such as diacylglycerol, phosphatidic acid, lysophosphatidic acid, and arachidonic acid, representing key elements of intra- and inter-cellular signaling and being involved in the regulation of several cellular mechanisms that can promote tumor progression and aggressiveness. In this review, it is summarized the current knowledge about the role of phospholipases in brain tumor progression, focusing on low- and high-grade gliomas, representing promising prognostic or therapeutic targets in cancer therapies due to their influential roles in cell proliferation, migration, growth, and survival. A deeper understanding of the phospholipases-related signaling pathways could be necessary to pave the way for new targeted therapeutic strategies.
Topics: Humans; Phospholipases; Brain Neoplasms; Brain; Glioma; Phospholipids
PubMed: 37238668
DOI: 10.3390/biom13050798 -
Cell Reports Methods Apr 2022Vesicle exo- and endocytosis mediate important biological functions, including synaptic transmission. In this issue of , Seong J. An et al. found that the fluorescently...
Vesicle exo- and endocytosis mediate important biological functions, including synaptic transmission. In this issue of , Seong J. An et al. found that the fluorescently tagged C2 domain of phospholipase A binds to membrane phosphatidylcholine and thus labels vesicle membrane, allowing for super-resolution and electron microscopic visualization of vesicle trafficking.
Topics: Synaptic Vesicles; Phospholipases A2; Endocytosis; Synaptic Transmission; Multimodal Imaging
PubMed: 35497501
DOI: 10.1016/j.crmeth.2022.100206 -
Journal of Materials Chemistry. B Sep 2022Overexpressed secretory phospholipase A2 (sPLA2) is found in many inflammatory diseases and various types of cancer. sPLA2 can catalyze the hydrolysis of phospholipid... (Review)
Review
Overexpressed secretory phospholipase A2 (sPLA2) is found in many inflammatory diseases and various types of cancer. sPLA2 can catalyze the hydrolysis of phospholipid sn-2 ester bonds to lysophosphatidylcholine and free fatty acids, and its catalytic substrate and downstream products mediate a series of cascade reactions and inflammatory responses. Furthermore, different subtypes of sPLA2 can participate in different physiological processes by driving unique lipid pathways. Recently, many diseases have not been treated by appropriate chemotherapy methods due to low bioavailability and severe side effects of clinically available small-molecule drugs. Therefore, they have great development prospects of revealing the therapeutic mechanism of sPLA2 and use sPLA2 as a potential therapeutic target for designing and exploring new drugs and their delivery systems. Notably, the emergence of nanomedicines in recent years provides a practical and innovative means for overcoming the challenges associated with chemotherapy. With these considerations in mind, this paper systematically reviews recent studies on nanomedicines targeting sPLA2 overexpression in various diseases during the past few years.
Topics: Esters; Fatty Acids, Nonesterified; Lysophosphatidylcholines; Nanomedicine; Phospholipases A2, Secretory; Phospholipids
PubMed: 35770707
DOI: 10.1039/d2tb00608a -
Kidney International Mar 2023The M-type phospholipase A2 receptor (PLA2R) is the major autoantigen of primary membranous nephropathy (MN). Despite many studies on B-cell epitopes recognized by...
The M-type phospholipase A2 receptor (PLA2R) is the major autoantigen of primary membranous nephropathy (MN). Despite many studies on B-cell epitopes recognized by antibodies, little is known about T-cell epitopes. Herein, we synthesized 123 linear peptides, each consisting of 15-22 amino acids with 8-12 amino acid overlaps, across ten domains of PLA2R. Their binding capacity to risk (DRB1∗1501, DRB1∗0301) and protective (DRB1∗0901, DRB1∗0701) HLA molecules was then assessed by flow cytometry. Proliferation of CD4+ T cells from patients with anti-PLA2R positive MN was analyzed after peptide stimulation. Cytokines produced by activated peripheral blood mononuclear cells were measured by cytometric bead arrays. We identified 17 PLA2R peptides that bound to both DRB1∗1501 and DRB1∗0301 molecules with high capacity. Some of these peptides showed decreased binding to heterozygous DRB1∗1501/0901 and DRB1∗0301/0701. Ten of the 17 peptides (CysR1, CysR10, CysR12, FnII-3, CTLD3-9, CTLD3-10, CTLD3-11, CTLD5-2-1, CTLD7-1 and CTLD7-2) induced significant proliferation of CD4+ T cells from patients with MN than cells from healthy individuals. Upon activation by these peptides, peripheral blood mononuclear cells from patients with MN produced higher levels of pro-inflammatory cytokines, predominantly IL-6, TNF-α, IL-10, IL-9 and IL-17. Thus, we mapped and identified ten peptides in the CysR, FnII, CTLD3, CTLD5, and CTLD7 domains of PLA2R as potential T-cell epitopes of MN. These findings are a first step towards developing peptide-specific immunotherapies.
Topics: Humans; Glomerulonephritis, Membranous; Epitopes, T-Lymphocyte; Receptors, Phospholipase A2; Leukocytes, Mononuclear; Amino Acids; Phospholipases A2; Cytokines; Autoantibodies
PubMed: 36549363
DOI: 10.1016/j.kint.2022.11.021 -
Renal Failure Dec 2023Hepatitis B virus-associated glomerulonephritis (HBV-GN) is one of the main types of secondary glomerular diseases, and podocyte injury is an important pathogenic...
INTRODUCTION
Hepatitis B virus-associated glomerulonephritis (HBV-GN) is one of the main types of secondary glomerular diseases, and podocyte injury is an important pathogenic mechanism of HBV-GN, participating in the occurrence and development of HBV-GN. However, the specific mechanism of podocyte injury remains to be studied.
METHODS
Human renal podocytes cultured were divided into six groups. The podocyte morphology was observed under a transmission electron microscope, and the expression of M-type phospholipase A receptor (M-PLAR) on the podocyte membrane was observed by indirect immunofluorescence staining under a fluorescence microscope. The pyroptosis rate and reactive oxygen species (ROS) of podocytes were assessed by FLICA/PI double staining and flow cytometry. Western blot (WB) and quantitative real-time PCR (qPCR) were used to determine the expression of PLAR, nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing card (ASC), caspase-1, IL-1β, and IL-18.
RESULTS
Hepatitis B virus X (HBx) transfected into human renal podocytes induced the overexpression of PLAR. Moreover, the overexpressed PLAR combined with secretory phospholipase A group IB (sPLA-IB) aggravated podocyte injury and increased the pyroptosis rate. In addition, the expression of ROS, the NLRP3 inflammasome and downstream inflammatory factors was increased. In contrast, after inhibiting the expression of PLAR and ROS, podocyte damage was alleviated, and the pyroptosis rate and the expression of genes related to the ROS-NLRP3 signaling pathway were decreased.
CONCLUSION
HBx-induced PLAR overexpression on the podocyte membrane can significantly upregulate the ROS-NLRP3 signaling pathway, thereby mediating podocyte pyroptosis.
Topics: Humans; Podocytes; NLR Family, Pyrin Domain-Containing 3 Protein; Pyroptosis; Reactive Oxygen Species; Signal Transduction; Phospholipases; Polyesters
PubMed: 36698326
DOI: 10.1080/0886022X.2023.2170808 -
Applied Microbiology and Biotechnology Jan 2021Phospholipases play vital roles in immune and inflammatory responses in mammals and plants; however, knowledge of phospholipase functions in fungi is limited. In this...
Phospholipases play vital roles in immune and inflammatory responses in mammals and plants; however, knowledge of phospholipase functions in fungi is limited. In this study, we investigated the effects of deleting predicted phospholipase genes on cellulase and xylanase production, and morphological phenotype, in Penicillium oxalicum. Individual deletion of nine of the ten predicted phospholipase genes resulted in alteration of cellulase and xylanase production, and the morphological phenotypes, to various degrees. The mutant ∆POX07277 lost 22.5 to 82.8% of cellulase (i.e., filter paper cellulase, carboxymethylcellulase, and p-nitrophenyl-β-cellobiosidase) and xylanase production, whereas p-nitrophenyl-β-glucopyranosidase production increased by 5.8-127.8 fold. POX07277 (P. oxalicum gene No. 07277) was predicted to encode phospholipase A2 and was found to negatively affect the sporulation of P. oxalicum. Comparative transcriptomic and quantitative reverse transcription-PCR analysis indicated that POX07277 dynamically affected the expression of cellulase and xylanase genes and the regulatory genes for fungal sporulation, under micro-crystalline cellulose induction. POX07277 was required for the expression of the known regulatory gene PoxCxrB (cellulolytic and xylanolytic regulator B in P. oxalicum), which is involved in cellulase and xylanase gene expression in P. oxalicum. Conversely, POX07277 expression was regulated by PoxCxrB. These findings will aid the understanding of phospholipase functions and provide novel insights into the mechanism of fungal cellulase and xylanase gene expression. KEY POINTS : • The roles of phospholipases were investigated in Penicillium oxalicum. • POX07277 (PLA) is required for the expression of cellulase and xylanase genes. • PoxCxrB dynamically regulated POX07277 expression.
Topics: Cellulase; Endo-1,4-beta Xylanases; Gene Expression Regulation, Fungal; Penicillium; Phospholipases
PubMed: 33394158
DOI: 10.1007/s00253-020-11065-1