scholarly journals A lysophospholipase plays role in generation of neutral-lipids required for hemozoin formation in malaria parasite

2019 ◽  
Author(s):  
Mohd Asad ◽  
Yoshiki Yamaryo-Botté ◽  
Mohammad E. Hossain ◽  
Vandana Thakur ◽  
Shaifali Jain ◽  
...  
Keyword(s):  
Neutral Lipid ◽  
Malaria Parasite ◽  
Neutral Lipids ◽  
Phospholipid Metabolism ◽  
Food Vacuole ◽  
Specific Role ◽  
Lipid Homeostasis ◽  
Knock Down ◽  
Parasite Survival

AbstractPhospholipid metabolism is crucial for membrane dynamics in malaria parasites during entire cycle in the host cell. Plasmodium falciparum harbours several members of phospholipase family, which play key role in phospholipid metabolism. Here we have functionally characterized a parasite lysophospholipase (PfLPL1) with a view to understand its role in lipid homeostasis. We used a regulated fluorescence affinity tagging, which allowed endogenous localization and transient knock-down of the protein. PffLPL1localizes to dynamic vesicular structures that traffic from parasite periphery, through the cytosol to get associated as a multi-vesicular neutral lipid rich body next to the food-vacuole during blood stages. Down-regulation of the PfLPL1 disrupted parasite lipid-homeostasis leading to significant reduction of neutral lipids in lipid-bodies. This hindered conversion of heme to hemozoin, leading to food-vacuole abnormalities, which in turn disrupted parasite development cycle and significantly inhibited parasite growth. Detailed lipidomic analyses of inducible knock-down parasites confirmed role of PfLPL1 in generation of neutral lipid through recycling of phospholipids. Our study thus suggests a specific role of PfLPL1 to generate neutral lipids in the parasite, which are essential for parasite survival.ImportancePresent study was undertaken with a view to understand the functional role of a unique lipase (lysophopholipase, PfLPL1) of the human malaria parasite. We utilized genetic approaches for GFP tagging as well as to knock-down the target protein in the parasite. Our studies showed that PfLPL1 associates closely with the lysosome like organelle in the parasite, the food-vacuole. During the blood stage parasite cycle, the food-vacuole is involved in degradation of host haemoglobin and conversion of heme to hemozoin. Genetic knock-down approaches and detailed lipidomic studies confirmed that PfLPL1 protein plays key role in generation of neutral lipid stores in the parasite; neutral lipids are essentially required for hemozoin formation in the parasite, a vital function of the food-vacuole. Overall, this study identified specific role of PfLPL1 in the parasite which is essential for parasite survival.

scholarly journals An essential vesicular-trafficking phospholipase mediates neutral lipid synthesis and contributes to hemozoin formation in Plasmodium falciparum

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Mohd Asad ◽  
Yoshiki Yamaryo-Botté ◽  
Mohammad E. Hossain ◽  
Vandana Thakur ◽  
Shaifali Jain ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Neutral Lipid ◽  
Neutral Lipids ◽  
Lipid Synthesis ◽  
Large Family ◽  
Degradation Pathway ◽  
Food Vacuole ◽  
Parasite Growth ◽  
Lipid Homeostasis ◽  
Parasite Development

Abstract Background Plasmodium falciparum is the pathogen responsible for the most devastating form of human malaria. As it replicates asexually in the erythrocytes of its human host, the parasite feeds on haemoglobin uptaken from these cells. Heme, a toxic by-product of haemoglobin utilization by the parasite, is neutralized into inert hemozoin in the food vacuole of the parasite. Lipid homeostasis and phospholipid metabolism are crucial for this process, as well as for the parasite’s survival and propagation within the host. P. falciparum harbours a uniquely large family of phospholipases, which are suggested to play key roles in lipid metabolism and utilization. Results Here, we show that one of the parasite phospholipase (P. falciparum lysophospholipase, PfLPL1) plays an essential role in lipid homeostasis linked with the haemoglobin degradation and heme conversion pathway. Fluorescence tagging showed that the PfLPL1 in infected blood cells localizes to dynamic vesicular structures that traffic from the host-parasite interface at the parasite periphery, through the cytosol, to get incorporated into a large vesicular lipid rich body next to the food-vacuole. PfLPL1 is shown to harbour enzymatic activity to catabolize phospholipids, and its transient downregulation in the parasite caused a significant reduction of neutral lipids in the food vacuole-associated lipid bodies. This hindered the conversion of heme, originating from host haemoglobin, into the hemozoin, and disrupted the parasite development cycle and parasite growth. Detailed lipidomic analyses of inducible knock-down parasites deciphered the functional role of PfLPL1 in generation of neutral lipid through recycling of phospholipids. Further, exogenous fatty-acids were able to complement downregulation of PfLPL1 to rescue the parasite growth as well as restore hemozoin levels. Conclusions We found that the transient downregulation of PfLPL1 in the parasite disrupted lipid homeostasis and caused a reduction in neutral lipids essentially required for heme to hemozoin conversion. Our study suggests a crucial link between phospholipid catabolism and generation of neutral lipids (TAGs) with the host haemoglobin degradation pathway.

scholarly journals GlmS mediated knock-down of a phospholipase expedite alternate pathway to generate phosphocholine required for phosphatidylcholine synthesis in Plasmodium falciparum

2021 ◽  
Author(s):  
Pradeep K Sheokand ◽  
Monika Narwal ◽  
Vandana Thakur ◽  
Asif Mohmmed
Keyword(s):  
Plasmodium Falciparum ◽  
Phospholipid Metabolism ◽  
Food Vacuole ◽  
Lipid Homeostasis ◽  
Parasite Development ◽  
Therapeutic Approaches ◽  
Knock Down ◽  
Alternate Pathway ◽  
Kennedy Pathway ◽  
Phosphatidylcholine Synthesis

Phospholipid synthesis is crucial for membrane proliferation in malaria parasites during the entire cycle in the host cell. The major phospholipid of parasite membranes, phosphatidylcholine (PC), is mainly synthesized through the Kennedy pathway. The phosphocholine required for this synthetic pathway is generated by phosphorylation of choline derived from catabolism of the lyso-phosphatidylcholine (LPC) scavenged from the host milieu. Here we have characterized a Plasmodium falciparum lysophospholipase (PfLPL20) which showed enzymatic activity on LPC substrate to generate choline. Using GFP- targeting approach, PfLPL20 was localized in vesicular structures associated with the neutral lipid storage bodies present juxtaposed to the food-vacuole. The C-terminal tagged glmS mediated inducible knock-down of PfLPL20 caused transient hindrance in the parasite development, however, the parasites were able to multiply efficiently, suggesting that PfLPL20 is not essential for the parasite. However, in PfLPL20 depleted parasites, transcript levels of enzyme of SDPM pathway (Serine Decarboxylase-Phosphoethanolamine Methyltransferase) were altered along with upregulation of phosphocholine and SAM levels; these results show upregulation of alternate pathway to generate the phosphocholine required for PC synthesis through the Kennedy pathway. Our study highlights presence of alternate pathways for lipid homeostasis/membrane-biogenesis in the parasite; these data could be useful to design future therapeutic approaches targeting phospholipid metabolism in the parasite.

scholarly journals The role of neutral lipid nanospheres in Plasmodium falciparum haem crystallization

2007 ◽  
Vol 402 (1) ◽  
pp. 197-204 ◽  
Author(s):  
John M. Pisciotta ◽  
Isabelle Coppens ◽  
Abhai K. Tripathi ◽  
Peter F. Scholl ◽  
Joel Shuman ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Neutral Lipid ◽  
Membrane Lipids ◽  
Neutral Lipids ◽  
Close Association ◽  
Subcellular Fractionation ◽  
Digestive Vacuole ◽  
Lipid Mixture ◽  
Intracellular Mechanism

The intraerythrocytic malaria parasite constructs an intracellular haem crystal, called haemozoin, within an acidic digestive vacuole where haemoglobin is degraded. Haem crystallization is the target of the widely used antimalarial quinoline drugs. The intracellular mechanism of molecular initiation of haem crystallization, whether by proteins, polar membrane lipids or by neutral lipids, has not been fully substantiated. In the present study, we show neutral lipid predominant nanospheres, which envelop haemozoin inside Plasmodium falciparum digestive vacuoles. Subcellular fractionation of parasite-derived haemozoin through a dense 1.7 M sucrose cushion identifies monoacylglycerol and diacylglycerol neutral lipids as well as some polar lipids in close association with the purified haemozoin. Global MS lipidomics detects monopalmitic glycerol and monostearic glycerol, but not mono-oleic glycerol, closely associated with haemozoin. The complex neutral lipid mixture rapidly initiates haem crystallization, with reversible pH-dependent quinoline inhibition associated with quinoline entry into the neutral lipid microenvironment. Neutral lipid nanospheres both enable haem crystallization in the presence of high globin concentrations and protect haem from H2O2 degradation. Conceptually, the present study shifts the intracellular microenvironment of haem crystallization and quinoline inhibition from a polar aqueous location to a non-polar neutral lipid nanosphere able to exclude water for efficient haem crystallization.

scholarly journals Recruitment of Peroxin14 to lipid droplets affects triglyceride storage in Drosophila

2021 ◽  
Author(s):  
Matthew Anderson-Baron ◽  
Kazuki Ueda ◽  
Julie Haskins ◽  
Sarah C Hughes ◽  
Andrew Simmonds
Keyword(s):  
Neutral Lipid ◽  
Lipid Droplet ◽  
Functional Role ◽  
Lipid Droplets ◽  
Droplet Surface ◽  
Lipid Homeostasis ◽  
Cellular Lipid ◽  
Peroxisome Biogenesis ◽  
Drosophila Cells

The activity of multiple organelles must be coordinated to ensure cellular lipid homeostasis. This includes the peroxisomes which metabolise certain lipids and lipid droplets which act as neutral lipid storage centres. Direct organellar contact between peroxisomes and lipid droplets has been observed, and interaction between proteins associated with the membranes of these organelles has been shown, but the functional role of these interactions is not clear. In Drosophila cells, we identified a novel localization of a subset of three transmembrane Peroxin proteins (Peroxin3, Peroxin13, and Peroxin14), normally required for peroxisome biogenesis, to newly formed lipid droplets. This event was not linked to significant changes in peroxisome size or number, nor was recruitment of other Peroxin proteins or mature peroxisomes observed. The presence of these Peroxin proteins at lipid droplets influences their function as changes in the relative levels of Peroxin14 associated with the lipid droplet surface directly affected the presence of regulatory perilipin and lipases with corresponding effects on triglyceride storage.

scholarly journals Benzoquinone alters the lipid homeostasis in Saccharomyces cerevisiae

2019 ◽  
Vol 8 (6) ◽  
pp. 1035-1041
Author(s):  
Abhishek Raj ◽  
Vasanthi Nachiappan
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Neutral Lipids ◽  
Gene Knockout ◽  
Phospholipid Metabolism ◽  
Lipid Homeostasis ◽  
Wild Type ◽  
Kennedy Pathway ◽  
Expression Studies ◽  
Gene Expression Studies ◽  
The Impact

Abstract Objective: To elucidate the impact of benzoquinone (BQ) on lipid homeostasis and cytotoxicity in Saccharomyces cerevisiae. Methods: The impact of BQ exposure on wild-type and knockouts of PC biosynthesizing genes revealed the alterations in the lipids that were analyzed by fluorescence microscopy, thin layer chromatography, and gene expression studies. Results: In yeast, BQ exposure reduced the growth pattern in wild-type cells. The gene knockout strains of the phospholipid metabolism altered the mRNA expression of the apoptosis genes – both caspase-dependent and independent. The BQ exposure revealed an increase in both the phospholipids and neutral lipids via the CDP:DAG and the Kennedy pathway genes. The accumulation of both neutral lipids and phospholipids during the BQ exposure was discrete and regulated by different pathways. Conclusions: BQ exposure inhibited cell growth, increased the reactive oxygen species (ROS), and altered membrane proliferation. The CDP:DAG and Kennedy pathway lipids also discretely altered by BQ, which is required for the membrane functions and energy purposes of life.

scholarly journals Amhr2-Cre–Mediated Global Tspo Knockout

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Jinjiang Fan ◽  
Enrico Campioli ◽  
Chantal Sottas ◽  
Barry Zirkin ◽  
Vassilios Papadopoulos
Keyword(s):  
Embryonic Development ◽  
Neutral Lipid ◽  
Conditional Knockout ◽  
Translocator Protein ◽  
Lipid Homeostasis ◽  
Loss Of Function ◽  
Sequencing Data ◽  
Compensatory Mechanisms ◽  
Normal Morphology

Abstract Although the role of translocator protein (TSPO) in cholesterol transport in steroid-synthesizing cells has been studied extensively, recent studies of TSPO genetic depletion have questioned its role. Amhr2-Cre mice have been used to generate Leydig cell-specific Tspo conditional knockout (cKO) mice. Using the same Cre line, we were unable to generate Tspo cKO mice possibly because of genetic linkage between Tspo and Amhr2 and coexpression of Amhr2-Cre and Tspo in early embryonic development. We found that Amhr2-Cre is expressed during preimplantation stages, resulting in global heterozygous mice (gHE; Amhr2-Cre+/–,Tspo–/+). Two gHE mice were crossed, generating Amhr2-Cre–mediated Tspo global knockout (gKO; Tspo–/–) mice. We found that 33.3% of blastocysts at E3.5 to E4.5 showed normal morphology, whereas 66.7% showed delayed development, which correlates with the expected Mendelian proportions of Tspo+/+ (25%), Tspo–/– (25%), and Tspo+/– (50%) genotypes from crossing 2 Tspo–/+ mice. Adult Tspo gKO mice exhibited disturbances in neutral lipid homeostasis and reduced intratesticular and circulating testosterone levels, but no change in circulating basal corticosterone levels. RNA-sequencing data from mouse adrenal glands and lungs revealed transcriptome changes in response to the loss of TSPO, including changes in several cholesterol-binding and transfer proteins. This study demonstrates that Amhr2-Cre can be used to produce Tspo gKO mice instead of cKO, and can serve as a new global “Cre deleter.” Moreover, our results show that Tspo deletion causes delayed preimplantation embryonic development, alters neutral lipid storage and steroidogenesis, and leads to transcriptome changes that may reflect compensatory mechanisms in response to the loss of function of TSPO.

Interpassivity and Misdemeanours: The Art of Thinking in Examples and the Žižekian Toolbox

2018 ◽  
Author(s):  
Robert Pfaller
Keyword(s):  
Specific Role ◽  
Slavoj Zizek ◽  
Slavoj Žižek ◽  
The Sublime

Starting from a passage from Slavoj Žižek`s brilliant book The Sublime Object of Ideology, the very passage on canned laughter that gave such precious support for the development of the theory of interpassivity, this chapter examines a question that has proved indispensable for the study of interpassivity: namely, what does it mean for a theory to proceed by examples? What is the specific role of the example in certain example-friendly theories, for example in Žižek’s philosophy?

Participation of ABCA1 transporter in development of chronic obstructive pulmonary disease

2020 ◽  
Vol 28 (3) ◽  
pp. 360-370
Author(s):  
Stanislav N. Kotlyarov ◽  
Anna A. Kotlyarova
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Significant Contribution ◽  
Modern Medicine ◽  
Lipid Homeostasis ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Reverse Transport ◽  
Current Paradigm

Despite all achievements of the modern medicine, the problem of chronic obstructive pulmonary disease (COPD) does not lose its relevance. The current paradigm suggests a key role of macrophages in inflammation in COPD. Macrophages are known to be heterogeneous in their functions. This heterogeneity is determined by their immunometabolic profile and also by peculiarities of lipid homeostasis of cells. Aim. To analyze the role of the ABCA1 transporter, a member of the ABC A subfamily, in the pathogenesis of COPD. The expression of ABCA1 in lung tissues is on the second place after the liver, which shows the important role of the carrier and of lipid homeostasis in the function of lungs. Analysis of the literature shows that participation of the transporter in inflammation consists in regulation of the content of cholesterol in the lipid rafts of the membranes, in phagocytosis and apoptosis. Conclusion. Through regulation of the process of reverse transport of cholesterol in macrophages of lungs, ABCA1 can change their inflammatory response, which makes a significant contribution to the pathogenesis of COPD.

Sign in / Sign up

Export Citation Format

Share Document