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The Journal of Biological Chemistry Dec 2021Many studies have confirmed the enzymatic activity of a mammalian phosphatidylcholine (PC) phospholipase C (PLC) (PC-PLC), which produces diacylglycerol (DAG) and...
Many studies have confirmed the enzymatic activity of a mammalian phosphatidylcholine (PC) phospholipase C (PLC) (PC-PLC), which produces diacylglycerol (DAG) and phosphocholine through the hydrolysis of PC in the absence of ceramide. However, the protein(s) responsible for this activity have never yet been identified. Based on the fact that tricyclodecan-9-yl-potassium xanthate can inhibit both PC-PLC and sphingomyelin synthase (SMS) activities, and SMS1 and SMS2 have a conserved catalytic domain that could mediate a nucleophilic attack on the phosphodiester bond of PC, we hypothesized that both SMS1 and SMS2 might have PC-PLC activity. In the present study, we found that purified recombinant SMS1 and SMS2 but not SMS-related protein have PC-PLC activity. Moreover, we prepared liver-specific Sms1/global Sms2 double-KO mice. We found that liver PC-PLC activity was significantly reduced and steady-state levels of PC and DAG in the liver were regulated by the deficiency, in comparison with control mice. Using adenovirus, we expressed Sms1 and Sms2 genes in the liver of the double-KO mice, respectively, and found that expressed SMS1 and SMS2 can hydrolyze PC to produce DAG and phosphocholine. Thus, SMS1 and SMS2 exhibit PC-PLC activity in vitro and in vivo.
Topics: Animals; COS Cells; Chlorocebus aethiops; Liver; Mice; Mice, Knockout; Phosphatidylcholines; Protein Domains; Recombinant Proteins; Transferases (Other Substituted Phosphate Groups); Type C Phospholipases
PubMed: 34774525
DOI: 10.1016/j.jbc.2021.101398 -
Medical Archives (Sarajevo, Bosnia and... Dec 2022Toxoplasma gondii, a protozoan parasite with a worldwide distribution, is considered to infect one-third of all humans. many species. The intracellular parasite...
BACKGROUND
Toxoplasma gondii, a protozoan parasite with a worldwide distribution, is considered to infect one-third of all humans. many species. The intracellular parasite Toxoplasma gondii causes toxoplasmosis. Numerous physiological abnormalities are documented in toxoplasmosis-infected women.
OBJECTIVE
This study aims to demonstrate the connection between cyclophilins, the phospholipase enzyme, and latent toxoplasmosis.
METHODS
The research was carried out between January 2022 and June 2022. out of 150 patients had blood samples drawn, 250 had serum samples drawn from women with toxoplasma gondi infection, and 50 had healthy samples drawn from Hila city, Iraq. To exclude subjects who had any medical disorders, information from the subjects was gathered via an interviewer-managed questionnaire. ELISA was used to examine the serum. Results: About 250 samples from women with infertility were infected with Toxoplasma gondii overall (24%) Enzyme-Linked Immunosorbent Assay was utilized to evaluate the levels of phospholipase and cyclophilin, while automated VIDAS family instruments were employed to determine the qualitative and quantitative anti-Toxoplasma-IgG-tests (ELISA). Since there was a substantial difference in the statistical analysis and a significant difference in the cyclophilin protein, parasite infection changed the quantity of the enzyme phospholipase.
CONCLUSION
This study put forth the theory that toxoplasmosis infection. Our investigation showed that patients with toxoplasma Gondi infection had higher levels of cyclophilins and phospholipase than control subjects.
Topics: Humans; Female; Cyclophilins; Phospholipases; Toxoplasmosis; Toxoplasma; Enzyme-Linked Immunosorbent Assay
PubMed: 36937607
DOI: 10.5455/medarh.2022.76.443-446 -
Atherosclerosis Jun 2021Secretory phospholipase A (PLA) hydrolyzes LDL phospholipids generating modified LDL particles (PLA-LDL) with increased atherogenic properties. Exocytosis of...
BACKGROUND AND AIMS
Secretory phospholipase A (PLA) hydrolyzes LDL phospholipids generating modified LDL particles (PLA-LDL) with increased atherogenic properties. Exocytosis of Weibel-Palade bodies (WPB) releases angiopoietin 2 (Ang2) and externalizes P-selectin, which both play important roles in vascular inflammation. Here, we investigated the effects of PLA-LDL on exocytosis of WPBs.
METHODS
Human coronary artery endothelial cells (HCAECs) were stimulated with PLA- LDL, and its uptake and effect on Ang2 release, leukocyte adhesion, and intracellular calcium levels were measured. The effects of PLA-LDL on Ang2 release and WPB exocytosis were measured in and ex vivo in mice.
RESULTS
Exposure of HCAECs to PLA-LDL triggered Ang2 secretion and promoted leukocyte-HCAEC interaction. Lysophosphatidylcholine was identified as a critical component of PLA-LDL regulating the WPB exocytosis, which was mediated by cell-surface proteoglycans, phospholipase C, intracellular calcium, and cytoskeletal remodeling. PLA-LDL also induced murine endothelial WPB exocytosis in blood vessels in and ex vivo, as evidenced by secretion of Ang2 in vivo, P-selectin translocation to plasma membrane in intact endothelial cells in thoracic artery and tracheal vessels, and reduced Ang2 staining in tracheal endothelial cells. Finally, in contrast to normal human coronary arteries, in which Ang2 was present only in the endothelial layer, at sites of advanced atherosclerotic lesions, Ang2 was detected also in the intima, media, and adventitia.
CONCLUSIONS
Our studies reveal PLA-LDL as a potent agonist of endothelial WPB exocytosis, resulting in increased secretion of Ang2 and translocation of P-selectin. The results provide mechanistic insight into PLA-LDL-dependent promotion of vascular inflammation and atherosclerosis.
Topics: Angiopoietin-2; Animals; Cells, Cultured; Endothelial Cells; Humans; Lysophosphatidylcholines; Mice; Phospholipases; Weibel-Palade Bodies
PubMed: 34020784
DOI: 10.1016/j.atherosclerosis.2021.04.007 -
Progress in Lipid Research Apr 2022Cell membranes are the initial site of stimulus perception from environment and phospholipids are the basic and important components of cell membranes. Phospholipases... (Review)
Review
Cell membranes are the initial site of stimulus perception from environment and phospholipids are the basic and important components of cell membranes. Phospholipases hydrolyze membrane lipids to generate various cellular mediators. These phospholipase-derived products, such as diacylglycerol, phosphatidic acid, inositol phosphates, lysophopsholipids, and free fatty acids, act as second messengers, playing vital roles in signal transduction during plant growth, development, and stress responses. This review focuses on the structure, substrate specificities, reaction requirements, and acting mechanism of several phospholipase families. It will discuss their functional significance in plant growth, development, and stress responses. In addition, it will highlight some critical knowledge gaps in the action mechanism, metabolic and signaling roles of these phospholipases and their products in the context of plant growth, development and stress responses.
Topics: Humans; Hydrolysis; Phosphatidic Acids; Phospholipase D; Phospholipases; Phospholipids; Type C Phospholipases
PubMed: 35134459
DOI: 10.1016/j.plipres.2022.101158 -
Fertility and Sterility Jul 2020
Topics: Algorithms; Female; Humans; Oocytes; Pregnancy; Sperm Injections, Intracytoplasmic; Type C Phospholipases
PubMed: 32532496
DOI: 10.1016/j.fertnstert.2020.03.038 -
Free Radical Biology & Medicine Aug 2023Lung fibroblast senescence is involved in the pathophysiology of chronic obstructive pulmonary disease (COPD). However, the mechanisms underlining this phenomenon are...
RATIONALE
Lung fibroblast senescence is involved in the pathophysiology of chronic obstructive pulmonary disease (COPD). However, the mechanisms underlining this phenomenon are still poorly understood. Secreted phospholipases (sPLA2, a subclass of phospholipases) are secreted by senescent cells and can in turn induce senescence. However, their role in fibroblasts senescence in COPD is unknown.
OBJECTIVES
The aim of this study was to analyze the role of sPLA2 in pulmonary fibroblast senescence.
METHODS
Fibroblasts were isolated from patients with COPD and control subjects, and senescence markers and inflammatory profile was analyzed. sPLA2 levels were quantified in serum of COPD and controls.
MAIN RESULTS
In comparison with non-smokers and smoker controls, senescent lung COPD fibroblasts exhibited a higher mRNA and protein expression of the sPLA2 isoform XIIA and of syndecan 4 (one of its receptors). sPLA2 XIIA induced in turn senescence of non-senescent pulmonary fibroblasts via a pathway involving consecutively syndecan 4, activation of MAPK and p-serine 727 STAT-3, increased mitochondrial ROS production, and activation of AMPK/p53. This pathway was associated with a specific inflammatory secretome (IL-10, IL-12 and TNFα), globally suggesting occurrence of a mitochondrial damage-induced senescence. COPD fibroblasts were more susceptible to this sPLA2 XIIA effect than cells from controls subjects. sPLA2 XIIA levels were significantly higher in serum from COPD patients as compared to controls.
CONCLUSION
sPLA2 XIIA is involved in senescence in COPD and could be a potential target to dampen this process.
Topics: Humans; Syndecan-4; Cellular Senescence; Pulmonary Disease, Chronic Obstructive; Lung; Fibroblasts; Phospholipases A2, Secretory
PubMed: 37257701
DOI: 10.1016/j.freeradbiomed.2023.05.025 -
Critical Reviews in Biotechnology Feb 2022Phospholipases D (PLDs) are important membrane lipid-modifying enzymes in eukaryotes. Phosphatidic acid, the product of PLD activity, is a vital signaling molecule.... (Review)
Review
Phospholipases D (PLDs) are important membrane lipid-modifying enzymes in eukaryotes. Phosphatidic acid, the product of PLD activity, is a vital signaling molecule. PLD-mediated lipid signaling has been the subject of extensive research leading to discovery of its crystal structure. PLDs are involved in the pathophysiology of several human diseases, therefore, viewed as promising targets for drug design. The availability of a eukaryotic PLD crystal structure will encourage PLD targeted drug designing. PLDs have been implicated in plants response to biotic and abiotic stresses. However, the molecular mechanism of response is not clear. Recently, several novel findings have shown that PLD mediated modulation of structural and developmental processes, such as: stomata movement, root growth and microtubule organization are crucial for plants adaptation to environmental stresses. Involvement of PLDs in regulating membrane remodeling, auxin mediated alteration of root system architecture and nutrient uptake to combat nitrogen and phosphorus deficiencies and magnesium toxicity is established. PLDs via vesicle trafficking modulate cytoskeleton and exocytosis to regulate self-incompatibility (SI) signaling in flowering plants, thereby contributes to plants hybrid vigor and diversity. In addition, the important role of PLDs has been recognized in biotechnologically important functions, including oil/TAG synthesis and maintenance of seed quality. In this review, we describe the crystal structure of a plant PLD and discuss the molecular mechanism of catalysis and activity regulation. Further, the role of PLDs in regulating plant development under biotic and abiotic stresses, nitrogen and phosphorus deficiency, magnesium ion toxicity, SI signaling and pollen tube growth and in important biotechnological applications has been discussed.
Topics: Phosphatidic Acids; Phospholipase D; Plant Development; Plants; Stress, Physiological
PubMed: 34167393
DOI: 10.1080/07388551.2021.1924113 -
Reproduction (Cambridge, England) May 2022Oocyte activation deficiency (OAD) remains the predominant cause of total/low fertilization rate in assisted reproductive technology. Phospholipase C zeta (PLCZ1) is the... (Review)
Review
Oocyte activation deficiency (OAD) remains the predominant cause of total/low fertilization rate in assisted reproductive technology. Phospholipase C zeta (PLCZ1) is the dominant sperm-specific factor responsible for triggering oocyte activation in mammals. OAD has been linked to numerous PLCZ1 abnormalities in patients experiencing failed in vitro fertilization or intracytoplasmic sperm injection cycles. While significant efforts have enhanced our understanding of the clinical relevance of PLCZ1, and the potential effects of genetic variants upon functionality, our ability to apply PLCZ1 in a diagnostic or therapeutic role remains limited. Artificial oocyte activation is the only option for patients experiencing OAD but lacks a reliable diagnostic approach. Immunofluorescence analysis has revealed that the levels and localization patterns of PLCZ1 within sperm can help us to indirectly diagnose a patient's ability to induce oocyte activation. Screening of the gene encoding PLCZ1 protein is also critical if we are to fully determine the extent to which genetic factors might play a role in the aberrant expression and/or localization patterns observed in infertile patients. Collectively, these findings highlight the clinical potential of PLCZ1, both as a prognostic indicator of OAD and eventually as a therapeutic agent. In this review, we focus on our understanding of the association between OAD and PLCZ1 by discussing the localization and expression of this key protein in human sperm, the potential genetic causes of OAD, and the diagnostic tools that are currently available to us to identify PLCZ1 deficiency and select patients that would benefit from targeted therapy.
Topics: Animals; Fertilization; Humans; Infertility, Male; Male; Mammals; Oocytes; Phosphoinositide Phospholipase C; Spermatozoa; Type C Phospholipases
PubMed: 35312629
DOI: 10.1530/REP-21-0458 -
Molecules (Basel, Switzerland) Apr 2022Phospholipase is an enzyme that hydrolyzes various phospholipid substrates at specific ester bonds and plays important roles such as membrane remodeling, as digestive...
Phospholipase is an enzyme that hydrolyzes various phospholipid substrates at specific ester bonds and plays important roles such as membrane remodeling, as digestive enzymes, and the regulation of cellular mechanism. Phospholipase proteins are divided into following the four major groups according to the ester bonds they cleave off: phospholipase A1 (PLA1), phospholipase A2 (PLA2), phospholipase C (PLC), and phospholipase D (PLD). Among the four phospholipase groups, PLA1 has been less studied than the other phospholipases. Here, we report the first molecular structures of plant PLA1s: AtDSEL and CaPLA1 derived from and , respectively. AtDSEL and CaPLA1 are novel PLA1s in that they form homodimers since PLAs are generally in the form of a monomer. The dimerization domain at the C-terminal of the AtDSEL and CaPLA1 makes hydrophobic interactions between each monomer, respectively. The C-terminal domain is also present in PLA1s of other plants, but not in PLAs of mammals and fungi. An activity assay of AtDSEL toward various lipid substrates demonstrates that AtDSEL is specialized for the cleavage of -1 acyl chains. This report reveals a new domain that exists only in plant PLA1s and suggests that the domain is essential for homodimerization.
Topics: Arabidopsis; Capsicum; Dimerization; Esters; Phospholipases A1; Plant Proteins
PubMed: 35408716
DOI: 10.3390/molecules27072317 -
Cancer Communications (London, England) Nov 2021
Topics: Ferroptosis; Humans; Phospholipases
PubMed: 34657380
DOI: 10.1002/cac2.12231