1
|
Dingwall CB, Sasaki Y, Strickland A, Summers DW, Bloom AJ, DiAntonio A, Milbrandt J. Suppressing phagocyte activation by overexpressing the phosphatidylserine lipase ABHD12 preserves sarmopathic nerves. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.20.599919. [PMID: 38979309 PMCID: PMC11230269 DOI: 10.1101/2024.06.20.599919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Programmed axon degeneration (AxD) is a key feature of many neurodegenerative diseases. In healthy axons, the axon survival factor NMNAT2 inhibits SARM1, the central executioner of AxD, preventing it from initiating the rapid local NAD+ depletion and metabolic catastrophe that precipitates axon destruction. Because these components of the AxD pathway act within neurons, it was also assumed that the timetable of AxD was set strictly by a cell-intrinsic mechanism independent of neuron-extrinsic processes later activated by axon fragmentation. However, using a rare human disease model of neuropathy caused by hypomorphic NMNAT2 mutations and chronic SARM1 activation (sarmopathy), we demonstrated that neuronal SARM1 can initiate macrophage-mediated axon elimination long before stressed-but-viable axons would otherwise succumb to cell-intrinsic metabolic failure. Investigating potential SARM1-dependent signals that mediate macrophage recognition and/or engulfment of stressed-but-viable axons, we found that chronic SARM1 activation triggers axonal blebbing and dysregulation of phosphatidylserine (PS), a potent phagocyte immunomodulatory molecule. Neuronal expression of the phosphatidylserine lipase ABDH12 suppresses nerve macrophage activation, preserves motor axon integrity, and rescues motor function in this chronic sarmopathy model. We conclude that PS dysregulation is an early SARM1-dependent axonal stress signal, and that blockade of phagocytic recognition and engulfment of stressed-but-viable axons could be an attractive therapeutic target for management of neurological disorders involving SARM1 activation.
Collapse
|
2
|
Sekerková G, Kilic S, Cheng YH, Fredrick N, Osmani A, Kim H, Opal P, Martina M. Phenotypical, genotypical and pathological characterization of the moonwalker mouse, a model of ataxia. Neurobiol Dis 2024; 195:106492. [PMID: 38575093 PMCID: PMC11089908 DOI: 10.1016/j.nbd.2024.106492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 03/13/2024] [Accepted: 04/01/2024] [Indexed: 04/06/2024] Open
Abstract
We performed a comprehensive study of the morphological, functional, and genetic features of moonwalker (MWK) mice, a mouse model of spinocerebellar ataxia caused by a gain of function of the TRPC3 channel. These mice show numerous behavioral symptoms including tremor, altered gait, circling behavior, impaired motor coordination, impaired motor learning and decreased limb strength. Cerebellar pathology is characterized by early and almost complete loss of unipolar brush cells as well as slowly progressive, moderate loss of Purkinje cell (PCs). Structural damage also includes loss of synaptic contacts from parallel fibers, swollen ER structures, and degenerating axons. Interestingly, no obvious correlation was observed between PC loss and severity of the symptoms, as the phenotype stabilizes around 2 months of age, while the cerebellar pathology is progressive. This is probably due to the fact that PC function is severely impaired much earlier than the appearance of PC loss. Indeed, PC firing is already impaired in 3 weeks old mice. An interesting feature of the MWK pathology that still remains to be explained consists in a strong lobule selectivity of the PC loss, which is puzzling considering that TRPC is expressed in every PC. Intriguingly, genetic analysis of MWK cerebella shows, among other alterations, changes in the expression of both apoptosis inducing and resistance factors possibly suggesting that damaged PCs initiate specific cellular pathways that protect them from overt cell loss.
Collapse
Affiliation(s)
- Gabriella Sekerková
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA.
| | - Sumeyra Kilic
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Yen-Hsin Cheng
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Natalie Fredrick
- Department of Neurology, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Anne Osmani
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Haram Kim
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Puneet Opal
- Department of Neurology, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Marco Martina
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA.
| |
Collapse
|
3
|
Chakraborty A, Kamat SS. Lysophosphatidylserine: A Signaling Lipid with Implications in Human Diseases. Chem Rev 2024; 124:5470-5504. [PMID: 38607675 DOI: 10.1021/acs.chemrev.3c00701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2024]
Abstract
Lysophosphatidylserine (lyso-PS) has emerged as yet another important signaling lysophospholipid in mammals, and deregulation in its metabolism has been directly linked to an array of human autoimmune and neurological disorders. It has an indispensable role in several biological processes in humans, and therefore, cellular concentrations of lyso-PS are tightly regulated to ensure optimal signaling and functioning in physiological settings. Given its biological importance, the past two decades have seen an explosion in the available literature toward our understanding of diverse aspects of lyso-PS metabolism and signaling and its association with human diseases. In this Review, we aim to comprehensively summarize different aspects of lyso-PS, such as its structure, biodistribution, chemical synthesis, and SAR studies with some synthetic analogs. From a biochemical perspective, we provide an exhaustive coverage of the diverse biological activities modulated by lyso-PSs, such as its metabolism and the receptors that respond to them in humans. We also briefly discuss the human diseases associated with aberrant lyso-PS metabolism and signaling and posit some future directions that may advance our understanding of lyso-PS-mediated mammalian physiology.
Collapse
Affiliation(s)
- Arnab Chakraborty
- Department of Biology, Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411008, Maharashtra, India
| | - Siddhesh S Kamat
- Department of Biology, Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411008, Maharashtra, India
| |
Collapse
|
4
|
Ahonen T, Ng CP, Farinha B, Almeida B, Victor BL, Reynolds C, Kalso E, Yli-Kauhaluoma J, Greaves J, Moreira VM. Probing the Interactions of Thiazole Abietane Inhibitors with the Human Serine Hydrolases ABHD16A and ABHD12. ACS Med Chem Lett 2023; 14:1404-1410. [PMID: 37849541 PMCID: PMC10577890 DOI: 10.1021/acsmedchemlett.3c00313] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 09/11/2023] [Indexed: 10/19/2023] Open
Abstract
12-Thiazole abietanes are highly selective reversible inhibitors of hABHD16A that could potentially alleviate neuroinflammation. In this study, we used synthetic chemistry, competitive activity-based protein profiling, and computational methodologies to try to establish relevant structural determinants of activity and selectivity of this class of compounds for inhibiting ABHD16A over ABHD12. Five compounds significantly inhibited hABHD16A but also very efficiently discriminated between inhibition of hABHD16A and hABHD12, with compound 35 being the most effective, at 100 μM (55.1 ± 8.7%; p < 0.0001). However, an outstanding switch in the selectivity toward ABHD12 was observed in the presence of a ring A ester, if the C2' position of the thiazole ring possessed a 1-hydroxyethyl group, as in compound 28. Although our data were inconclusive as to whether the observed enzyme inhibition is allosteric or not, we anticipate that the structure-activity relationships presented herein will inspire future drug discovery efforts in this field.
Collapse
Affiliation(s)
- Tiina
J. Ahonen
- Drug
Research Program, Division of Pharmaceutical Chemistry and Technology,
Faculty of Pharmacy, University of Helsinki, 00014 Helsinki, Finland
| | - Choa P. Ng
- Research
Centre for Health and Life Sciences, Coventry
University, CV1 5RW Coventry, U.K.
| | - Beatriz Farinha
- BioISI—Biosystems
& Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016 Lisboa, Portugal
| | - Bárbara Almeida
- BioISI—Biosystems
& Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016 Lisboa, Portugal
| | - Bruno L. Victor
- BioISI—Biosystems
& Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016 Lisboa, Portugal
| | - Christopher Reynolds
- Research
Centre for Health and Life Sciences, Coventry
University, CV1 5RW Coventry, U.K.
- School
of Life Sciences, University of Essex, CO4 3SQ Colchester, U.K.
| | - Eija Kalso
- Department
of Pharmacology, Faculty of Medicine, University
of Helsinki, 00014 Helsinki, Finland
- Department
of Anaesthesiology, Intensive Care and Pain Medicine, Helsinki University Hospital and University of Helsinki, FI-00029 Helsinki, Finland
| | - Jari Yli-Kauhaluoma
- Drug
Research Program, Division of Pharmaceutical Chemistry and Technology,
Faculty of Pharmacy, University of Helsinki, 00014 Helsinki, Finland
| | - Jennifer Greaves
- Research
Centre for Health and Life Sciences, Coventry
University, CV1 5RW Coventry, U.K.
| | - Vânia M. Moreira
- Drug
Research Program, Division of Pharmaceutical Chemistry and Technology,
Faculty of Pharmacy, University of Helsinki, 00014 Helsinki, Finland
- Centre
for Neuroscience and Cell Biology, and Centre for Innovative Biomedicine
and Biotechnology, University of Coimbra, 3000-548 Coimbra, Portugal
- Laboratory
of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
| |
Collapse
|
5
|
Muñoz JP, Basei FL, Rojas ML, Galvis D, Zorzano A. Mechanisms of Modulation of Mitochondrial Architecture. Biomolecules 2023; 13:1225. [PMID: 37627290 PMCID: PMC10452872 DOI: 10.3390/biom13081225] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/27/2023] [Accepted: 08/01/2023] [Indexed: 08/27/2023] Open
Abstract
Mitochondrial network architecture plays a critical role in cellular physiology. Indeed, alterations in the shape of mitochondria upon exposure to cellular stress can cause the dysfunction of these organelles. In this scenario, mitochondrial dynamics proteins and the phospholipid composition of the mitochondrial membrane are key for fine-tuning the modulation of mitochondrial architecture. In addition, several factors including post-translational modifications such as the phosphorylation, acetylation, SUMOylation, and o-GlcNAcylation of mitochondrial dynamics proteins contribute to shaping the plasticity of this architecture. In this regard, several studies have evidenced that, upon metabolic stress, mitochondrial dynamics proteins are post-translationally modified, leading to the alteration of mitochondrial architecture. Interestingly, several proteins that sustain the mitochondrial lipid composition also modulate mitochondrial morphology and organelle communication. In this context, pharmacological studies have revealed that the modulation of mitochondrial shape and function emerges as a potential therapeutic strategy for metabolic diseases. Here, we review the factors that modulate mitochondrial architecture.
Collapse
Affiliation(s)
- Juan Pablo Muñoz
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
- Institut d’Investigació Biomèdica Sant Pau (IIB SANT PAU), 08041 Barcelona, Spain
| | - Fernanda Luisa Basei
- Faculdade de Ciências Farmacêuticas, Universidade Estadual de Campinas, 13083-871 Campinas, SP, Brazil
| | - María Laura Rojas
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba X5000HUA, Argentina
| | - David Galvis
- Programa de Química Farmacéutica, Universidad CES, Medellín 050031, Colombia
| | - Antonio Zorzano
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
- Institute for Research in Biomedicine (IRB Barcelona), 08028 Barcelona, Spain
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain
| |
Collapse
|
6
|
Molecular insights on PS-PLA 1 lipase activity of human ABHD16B. Biophys Chem 2023; 296:106976. [PMID: 36841071 DOI: 10.1016/j.bpc.2023.106976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/09/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023]
Abstract
The human alpha beta hydrolase domain (ABHD) proteins are ubiquitous and regulate the cellular lipids' anabolic and catabolic processes. The structural aspects for specific biochemical function of many ABHD proteins related to physiological disorders and its link to pathological conditions remain unknown. Here putative human ABHD16B protein was overexpressed in Saccharomyces cerevisiae for its biological activity. In-vitro enzymatic assay of the recombinant ABHD16B protein with fluorescently tagged glycerophospholipids revealed that the PLA1 activity is observed with phosphatidylserine (PS). In addition, it efficiently hydrolyzed monoacylglycerol over triacylglycerols. Further, molecular dynamic simulations and per residue binding free energy decomposition analysis revealed that the origin of PS-specific PLA1 activity of ABHD16B is due to the electrostatic interaction of the PS head group with K8, R319, and E178, which led to having the hydrogen bond interaction of sn-1 acyl chain ester to the catalytic site residues. Site-directed mutagenesis of the 245GXSXG249 motif of ABHD16B reduced the maximal lipase activity of PS and MAG. In summary, these results revealed that ABHD16B plays a vital role in PS selectivity that in turn, controls the specific subcellular pools of 2-LPS metabolism in the tissues at low pH.
Collapse
|
7
|
Abstract
Interferon-inducible transmembrane (IFITM) proteins are small homologous proteins that are encoded by the interferon-stimulated genes (ISGs), which can be strongly induced by interferon (IFN) and provide resistance to invasion by a variety of viral pathogens. However, the exact molecular mechanisms underlying this function have remained elusive. The antiviral activity of IFITMs from different species depends on S-palmitoylation at conserved cysteine residues. However, specific enzymes involved in the dynamic palmitoylation cycle of IFITMs, especially depalmitoylase, have not yet been reported. Here, we demonstrate that α/-hydrolase domain-containing 16A (ABHD16A) is a depalmitoylase and a negative regulator of IFITM protein that can catalyze the depalmitoyl reaction of S-palmitoylated IFITM proteins, thereby decreasing their antiviral activities on RNA viruses. Using the acyl-PEGyl exchange gel shift (APEGS) assay, we identified ABHD16A proteins from humans, pigs, and mice that can directly participate in the palmitoylation/depalmitoylation cycles of IFITMs in the constructed abhd16a-/- cells and ABHD16A-overexpressing cells. Furthermore, we showed that ABHD16A functions as a regulator of subcellular localization of IFITM proteins and is related to the immune system. It is tempting to suggest that pharmacological intervention in IFITMs and ABHD16A can be achieved either through controlling their expression or regulating their activity, thereby providing a broad-spectrum therapeutic strategy for animal viral diseases. IMPORTANCE IFITM protein is the cells first line of antiviral defense that blocks early stages of viral replication; the underlying mechanism might be associated with the proper distribution in cells. The palmitoylation/depalmitoylation cycle can dynamically regulate protein localization, stability, and function. This work is the first one that found the critical enzyme that participates in the palmitoylation/depalmitoylation cycle of IFITM, and this type of palmitoyl loss may be an essential regulation mode for balancing the antiviral functions of the IFN pathway. These findings imply that the pharmacological intervention in IFITM and ABHD16A, either through controlling their expression or regulating their activities, could provide a broad-spectrum therapeutic strategy for animal viral diseases and complications linked to interferon elevation.
Collapse
|
8
|
Lipid Dyshomeostasis and Inherited Cerebellar Ataxia. Mol Neurobiol 2022; 59:3800-3828. [PMID: 35420383 PMCID: PMC9148275 DOI: 10.1007/s12035-022-02826-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 04/01/2022] [Indexed: 12/04/2022]
Abstract
Cerebellar ataxia is a form of ataxia that originates from dysfunction of the cerebellum, but may involve additional neurological tissues. Its clinical symptoms are mainly characterized by the absence of voluntary muscle coordination and loss of control of movement with varying manifestations due to differences in severity, in the site of cerebellar damage and in the involvement of extracerebellar tissues. Cerebellar ataxia may be sporadic, acquired, and hereditary. Hereditary ataxia accounts for the majority of cases. Hereditary ataxia has been tentatively divided into several subtypes by scientists in the field, and nearly all of them remain incurable. This is mainly because the detailed mechanisms of these cerebellar disorders are incompletely understood. To precisely diagnose and treat these diseases, studies on their molecular mechanisms have been conducted extensively in the past. Accumulating evidence has demonstrated that some common pathogenic mechanisms exist within each subtype of inherited ataxia. However, no reports have indicated whether there is a common mechanism among the different subtypes of inherited cerebellar ataxia. In this review, we summarize the available references and databases on neurological disorders characterized by cerebellar ataxia and show that a subset of genes involved in lipid homeostasis form a new group that may cause ataxic disorders through a common mechanism. This common signaling pathway can provide a valuable reference for future diagnosis and treatment of ataxic disorders.
Collapse
|
9
|
Emerging Role of Phospholipids and Lysophospholipids for Improving Brain Docosahexaenoic Acid as Potential Preventive and Therapeutic Strategies for Neurological Diseases. Int J Mol Sci 2022; 23:ijms23073969. [PMID: 35409331 PMCID: PMC9000073 DOI: 10.3390/ijms23073969] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/23/2022] [Accepted: 03/25/2022] [Indexed: 01/25/2023] Open
Abstract
Docosahexaenoic acid (DHA, 22:6n-3) is an omega-3 polyunsaturated fatty acid (PUFA) essential for neural development, learning, and vision. Although DHA can be provided to humans through nutrition and synthesized in vivo from its precursor alpha-linolenic acid (ALA, 18:3n-3), deficiencies in cerebral DHA level were associated with neurodegenerative diseases including Parkinson’s and Alzheimer’s diseases. The aim of this review was to develop a complete understanding of previous and current approaches and suggest future approaches to target the brain with DHA in different lipids’ forms for potential prevention and treatment of neurodegenerative diseases. Since glycerophospholipids (GPs) play a crucial role in DHA transport to the brain, we explored their biosynthesis and remodeling pathways with a focus on cerebral PUFA remodeling. Following this, we discussed the brain content and biological properties of phospholipids (PLs) and Lyso-PLs with omega-3 PUFA focusing on DHA’s beneficial effects in healthy conditions and brain disorders. We emphasized the cerebral accretion of DHA when esterified at sn-2 position of PLs and Lyso-PLs. Finally, we highlighted the importance of DHA-rich Lyso-PLs’ development for pharmaceutical applications since most commercially available DHA formulations are in the form of PLs or triglycerides, which are not the preferred transporter of DHA to the brain.
Collapse
|
10
|
Nguyen TT, Voeltz GK. An ER phospholipid hydrolase drives ER-associated mitochondrial constriction for fission and fusion. eLife 2022; 11:84279. [PMID: 36448541 PMCID: PMC9725753 DOI: 10.7554/elife.84279] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 11/29/2022] [Indexed: 12/02/2022] Open
Abstract
Mitochondria are dynamic organelles that undergo cycles of fission and fusion at a unified platform defined by endoplasmic reticulum (ER)-mitochondria membrane contact sites (MCSs). These MCSs or nodes co-localize fission and fusion machinery. We set out to identify how ER-associated mitochondrial nodes can regulate both fission and fusion machinery assembly. We have used a promiscuous biotin ligase linked to the fusion machinery, Mfn1, and proteomics to identify an ER membrane protein, ABHD16A, as a major regulator of node formation. In the absence of ABHD16A, fission and fusion machineries fail to recruit to ER-associated mitochondrial nodes, and fission and fusion rates are significantly reduced. ABHD16A contains an acyltransferase motif and an α/β hydrolase domain, and point mutations in critical residues of these regions fail to rescue the formation of ER-associated mitochondrial hot spots. These data suggest a mechanism whereby ABHD16A functions by altering phospholipid composition at ER-mitochondria MCSs. Our data present the first example of an ER membrane protein that regulates the recruitment of both fission and fusion machineries to mitochondria.
Collapse
Affiliation(s)
- Tricia T Nguyen
- Howard Hughes Medical InstituteChevy ChaseUnited States,Department of Molecular, Cellular and Developmental Biology, University of ColoradoBoulderUnited States
| | - Gia K Voeltz
- Howard Hughes Medical InstituteChevy ChaseUnited States,Department of Molecular, Cellular and Developmental Biology, University of ColoradoBoulderUnited States
| |
Collapse
|
11
|
Singh S, Kamat SS. The loss of enzymatic activity of the PHARC-associated lipase ABHD12 results in increased phagocytosis that causes neuroinflammation. Eur J Neurosci 2021; 54:7442-7457. [PMID: 34727579 PMCID: PMC7612011 DOI: 10.1111/ejn.15516] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 10/12/2021] [Accepted: 10/28/2021] [Indexed: 01/08/2023]
Abstract
Phagocytosis is an important evolutionary conserved process, essential for clearing pathogens and cellular debris in higher organisms, including humans. This well‐orchestrated innate immunological response is intricately regulated by numerous cellular factors, important amongst which are the immunomodulatory lysophosphatidylserines (lyso‐PSs) and the pro‐apoptotic oxidized phosphatidylserines (PSs) signalling lipids. Interestingly, in mammals, both these signalling lipids are physiologically regulated by the lipase ABHD12, mutations of which cause the human neurological disorder PHARC. Despite the biomedical significance of this lipase, detailed mechanistic studies and the specific contribution of ABHD12 to innate processes like phagocytosis remain poorly understood. Here, by immunohistochemical and immunofluorescence approaches, using the murine model of PHARC, we show, that upon an inflammatory stimulus, activated microglial cells in the cerebellum of mice deficient in ABHD12 have an amoeboid morphology, increased soma size and display heightened phagocytosis activity. We also report that upon an inflammatory stimulus, cerebellar levels of ABHD12 increase to possibly metabolize the heightened oxidized PS levels, temper phagocytosis and, in turn, control neuroinflammation during oxidative stress. Next, to complement these findings, with the use of biochemical approaches in cultured microglial cells, we show that the pharmacological inhibition and/or genetic deletion of ABHD12 results in increased phagocytic uptake in a fluorescent bead uptake assay. Together, our studies provide compelling evidence that ABHD12 plays an important role in regulating phagocytosis in cerebellar microglial cells and provides a possible explanation, as to why human PHARC subjects display neuroinflammation and atrophy in the cerebellum.
Collapse
Affiliation(s)
- Shubham Singh
- Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Pune, India
| | - Siddhesh S Kamat
- Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Pune, India
| |
Collapse
|
12
|
Lemire G, Ito YA, Marshall AE, Chrestian N, Stanley V, Brady L, Tarnopolsky M, Curry CJ, Hartley T, Mears W, Derksen A, Rioux N, Laflamme N, Hutchison HT, Pais LS, Zaki MS, Sultan T, Dane AD, Gleeson JG, Vaz FM, Kernohan KD, Bernard G, Boycott KM, Boycott KM. ABHD16A deficiency causes a complicated form of hereditary spastic paraplegia associated with intellectual disability and cerebral anomalies. Am J Hum Genet 2021; 108:2017-2023. [PMID: 34587489 DOI: 10.1016/j.ajhg.2021.09.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 09/08/2021] [Indexed: 01/18/2023] Open
Abstract
ABHD16A (abhydrolase domain-containing protein 16A, phospholipase) encodes the major phosphatidylserine (PS) lipase in the brain. PS lipase synthesizes lysophosphatidylserine, an important signaling lipid that functions in the mammalian central nervous system. ABHD16A has not yet been associated with a human disease. In this report, we present a cohort of 11 affected individuals from six unrelated families with a complicated form of hereditary spastic paraplegia (HSP) who carry bi-allelic deleterious variants in ABHD16A. Affected individuals present with a similar phenotype consisting of global developmental delay/intellectual disability, progressive spasticity affecting the upper and lower limbs, and corpus callosum and white matter anomalies. Immunoblot analysis on extracts from fibroblasts from four affected individuals demonstrated little to no ABHD16A protein levels compared to controls. Our findings add ABHD16A to the growing list of lipid genes in which dysregulation can cause complicated forms of HSP and begin to describe the molecular etiology of this condition.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Kym M Boycott
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada.
| |
Collapse
|
13
|
Yahia A, Elsayed LEO, Valter R, Hamed AAA, Mohammed IN, Elseed MA, Salih MA, Esteves T, Auger N, Abubaker R, Koko M, Abozar F, Malik H, Adil R, Emad S, Musallam MA, Idris R, Eltazi IZM, Babai A, Ahmed EAA, Abd Allah ASI, Mairey M, Ahmed AKMA, Elbashir MI, Brice A, Ibrahim ME, Ahmed AE, Lamari F, Stevanin G. Pathogenic Variants in ABHD16A Cause a Novel Psychomotor Developmental Disorder With Spastic Paraplegia. Front Neurol 2021; 12:720201. [PMID: 34489854 PMCID: PMC8417901 DOI: 10.3389/fneur.2021.720201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/28/2021] [Indexed: 12/20/2022] Open
Abstract
Introduction: Hereditary spastic paraplegia is a clinically and genetically heterogeneous neurological entity that includes more than 80 disorders which share lower limb spasticity as a common feature. Abnormalities in multiple cellular processes are implicated in their pathogenesis, including lipid metabolism; but still 40% of the patients are undiagnosed. Our goal was to identify the disease-causing variants in Sudanese families excluded for known genetic causes and describe a novel clinico-genetic entity. Methods: We studied four patients from two unrelated consanguineous Sudanese families who manifested a neurological phenotype characterized by spasticity, psychomotor developmental delay and/or regression, and intellectual impairment. We applied next-generation sequencing, bioinformatics analysis, and Sanger sequencing to identify the genetic culprit. We then explored the consequences of the identified variants in patients-derived fibroblasts using targeted-lipidomics strategies. Results and Discussion: Two homozygous variants in ABHD16A segregated with the disease in the two studied families. ABHD16A encodes the main brain phosphatidylserine hydrolase. In vitro, we confirmed that ABHD16A loss of function reduces the levels of certain long-chain lysophosphatidylserine species while increases the levels of multiple phosphatidylserine species in patient's fibroblasts. Conclusion:ABHD16A loss of function is implicated in the pathogenesis of a novel form of complex hereditary spastic paraplegia.
Collapse
Affiliation(s)
- Ashraf Yahia
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan.,Department of Biochemistry, Faculty of Medicine, National University, Khartoum, Sudan.,Sorbonne Université, Institut du Cerveau-Paris Brain Institute, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France.,Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
| | - Liena E O Elsayed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan.,College of Medicine, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Remi Valter
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France.,Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
| | - Ahlam A A Hamed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | | | - Maha A Elseed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Mustafa A Salih
- Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Typhaine Esteves
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France.,Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
| | - Nicolas Auger
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France.,Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
| | - Rayan Abubaker
- Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Mahmoud Koko
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, Tubingen, Germany
| | - Fatima Abozar
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Hiba Malik
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Rawaa Adil
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Sara Emad
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | | | - Razaz Idris
- Letterkenny University Hospital, Letterkenny, Ireland
| | - Isra Z M Eltazi
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Arwa Babai
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Elhami A A Ahmed
- UNESCO Chair on Bioethics, University of Khartoum, Khartoum, Sudan
| | | | - Mathilde Mairey
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Ahmed K M A Ahmed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan.,Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Suita, Japan.,Immunology Frontier Research Center, Osaka University, Suita, Japan
| | | | - Alexis Brice
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Muntaser E Ibrahim
- Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Ammar E Ahmed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Foudil Lamari
- APHP, Pitié-Salpêtrière Hospital, Metabolic Biochemistry unit, Department of Biochemistry of Neurometabolic Diseases, Paris, France
| | - Giovanni Stevanin
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France.,Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
| |
Collapse
|
14
|
Khandelwal N, Shaikh M, Mhetre A, Singh S, Sajeevan T, Joshi A, Balaji KN, Chakrapani H, Kamat SS. Fatty acid chain length drives lysophosphatidylserine-dependent immunological outputs. Cell Chem Biol 2021; 28:1169-1179.e6. [PMID: 33571455 PMCID: PMC7611549 DOI: 10.1016/j.chembiol.2021.01.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/30/2020] [Accepted: 01/06/2021] [Indexed: 12/23/2022]
Abstract
In humans, lysophosphatidylserines (lyso-PSs) are potent lipid regulators of important immunological processes. Given their structural diversity and commercial paucity, here we report the synthesis of methyl esters of lyso-PS (Me-lyso-PSs) containing medium- to very-long-chain (VLC) lipid tails. We show that Me-lyso-PSs are excellent substrates for the lyso-PS lipase ABHD12, and that these synthetic lipids are acted upon by cellular carboxylesterases to produce lyso-PSs. Next, in macrophages we demonstrate that VLC lyso-PSs orchestrate pro-inflammatory responses and in turn neuroinflammation via a Toll-like receptor 2 (TLR2)-dependent pathway. We also show that long-chain (LC) lyso-PSs robustly induce intracellular cyclic AMP production, cytosolic calcium influx, and phosphorylation of the nodal extracellular signal-regulated kinase to regulate macrophage activation via a TLR2-independent pathway. Finally, we report that LC lyso-PSs potently elicit histamine release during the mast cell degranulation process, and that ABHD12 is the major lyso-PS lipase in these immune cells.
Collapse
Affiliation(s)
- Neha Khandelwal
- Department of Biology, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India
| | - Minhaj Shaikh
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India
| | - Amol Mhetre
- Department of Biology, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India.
| | - Shubham Singh
- Department of Biology, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India
| | - Theja Sajeevan
- Department of Biology, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India
| | - Alaumy Joshi
- Department of Biology, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India
| | | | - Harinath Chakrapani
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India.
| | - Siddhesh S Kamat
- Department of Biology, Indian Institute of Science Education and Research (IISER) Pune, Dr. Homi Bhabha Road, Pashan, Pune, Maharashtra 411008, India.
| |
Collapse
|
15
|
Minamihata T, Takano K, Nakamura Y, Seto R, Moriyama M. Increase in Cellular Lysophosphatidylserine Content Exacerbates Inflammatory Responses in LPS-Activated Microglia. Neurochem Res 2021; 47:2602-2616. [PMID: 34383250 DOI: 10.1007/s11064-021-03425-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 07/20/2021] [Accepted: 08/06/2021] [Indexed: 10/20/2022]
Abstract
Mutations in alpha/beta-hydrolase domain containing (ABHD) 12 gene, which encodes lysophosphatidylserine (LysoPS) lipase, cause the neurodegenerative disease PHARC (Polyneuropathy, Hearing loss, Ataxia, Retinitis pigmentosa, Cataract). Since ABHD12 is expressed by microglia in the central nervous system and is localized to the endoplasmic reticulum, accumulation of intracellular LysoPS by ABHD12 mutations is assumed to be one of the pathological mechanisms associated with microglial activation in PHARC. However, the role of microglia in the PHARC brain and the relationship between microglial function and cellular LysoPS content remains unclear. Therefore, we explored the influence of cellular LysoPS content in microglial inflammatory responses. We evaluated the effects of inhibitors of cellular LysoPS metabolism, KC01 and DO-264, on inflammatory responses using a lipopolysaccharide (LPS)-stimulated mouse microglial cell line, BV-2 and primary microglia. Treatment of DO-264, an inhibitor of cellular LysoPS degradation, enhanced LPS-induced phagocytosis concomitant with the increase in cellular LysoPS content in BV-2 cells. On the other hand, treatment with KC01, an agent had been developed as an inhibitor of LysoPS synthase, reduced phagocytosis without affecting cellular LysoPS content. Such effects of both inhibitors on phagocytosis were also confirmed using primary microglia. KC01 treatment decreased nitric oxide (NO) production, accompanied by a reduction in inducible NO synthase expression in BV-2 microglia. KC01 also suppressed LPS-induced generation of intracellular reactive oxygen species and cytokines such as interleukin-6. Our results suggest that increase in cellular LysoPS levels can exacerbate microglial inflammatory responses. Treatment to prevent the increase in cellular LysoPS in microglia may have therapeutic potential for PHARC.
Collapse
Affiliation(s)
- Tomoki Minamihata
- Laboratory of Integrative Physiology in Veterinary Sciences, Osaka Prefecture University, 1-58 Rinku Ourai Kita, Izumisano, Osaka, 598-8531, Japan
| | - Katsura Takano
- Laboratory of Integrative Physiology in Veterinary Sciences, Osaka Prefecture University, 1-58 Rinku Ourai Kita, Izumisano, Osaka, 598-8531, Japan
| | - Yoichi Nakamura
- Laboratory of Integrative Physiology in Veterinary Sciences, Osaka Prefecture University, 1-58 Rinku Ourai Kita, Izumisano, Osaka, 598-8531, Japan
| | - Ryoya Seto
- Chemicals Evaluation and Research Institute, Kitakatsushika, Saitama, Japan
| | - Mitsuaki Moriyama
- Laboratory of Integrative Physiology in Veterinary Sciences, Osaka Prefecture University, 1-58 Rinku Ourai Kita, Izumisano, Osaka, 598-8531, Japan.
| |
Collapse
|
16
|
Bononi G, Tuccinardi T, Rizzolio F, Granchi C. α/β-Hydrolase Domain (ABHD) Inhibitors as New Potential Therapeutic Options against Lipid-Related Diseases. J Med Chem 2021; 64:9759-9785. [PMID: 34213320 PMCID: PMC8389839 DOI: 10.1021/acs.jmedchem.1c00624] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Much of the experimental evidence in the literature has linked altered lipid metabolism to severe diseases such as cancer, obesity, cardiovascular pathologies, diabetes, and neurodegenerative diseases. Therefore, targeting key effectors of the dysregulated lipid metabolism may represent an effective strategy to counteract these pathological conditions. In this context, α/β-hydrolase domain (ABHD) enzymes represent an important and diversified family of proteins, which are involved in the complex environment of lipid signaling, metabolism, and regulation. Moreover, some members of the ABHD family play an important role in the endocannabinoid system, being designated to terminate the signaling of the key endocannabinoid regulator 2-arachidonoylglycerol. This Perspective summarizes the research progress in the development of ABHD inhibitors and modulators: design strategies, structure-activity relationships, action mechanisms, and biological studies of the main ABHD ligands will be highlighted.
Collapse
Affiliation(s)
- Giulia Bononi
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Tiziano Tuccinardi
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Flavio Rizzolio
- Pathology Unit, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, 33081 Aviano, Italy.,Department of Molecular Sciences and Nanosystems, Ca' Foscari University, 30123 Venezia, Italy
| | - Carlotta Granchi
- Department of Pharmacy, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy
| |
Collapse
|
17
|
Zhao Y, Hasse S, Bourgoin SG. Phosphatidylserine-specific phospholipase A1: A friend or the devil in disguise. Prog Lipid Res 2021; 83:101112. [PMID: 34166709 DOI: 10.1016/j.plipres.2021.101112] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/30/2021] [Accepted: 06/18/2021] [Indexed: 02/06/2023]
Abstract
Various human tissues and cells express phospholipase A1 member A (PLA1A), including the liver, lung, prostate gland, and immune cells. The enzyme belongs to the pancreatic lipase family. PLA1A specifically hydrolyzes sn-1 fatty acid of phosphatidylserine (PS) or 1-acyl-lysophosphatidylserine (1-acyl-lysoPS). PS externalized by activated cells or apoptotic cells or extracellular vesicles is a potential source of substrate for the production of unsaturated lysoPS species by PLA1A. Maturation and functions of many immune cells, such as T cells, dendritic cells, macrophages, and mast cells, can be regulated by PLA1A and lysoPS. Several lysoPS receptors, including GPR34, GPR174 and P2Y10, have been identified. High serum levels and high PLA1A expression are associated with autoimmune disorders such as Graves' disease and systemic lupus erythematosus. Increased expression of PLA1A is associated with metastatic melanomas. PLA1A may contribute to cardiometabolic disorders through mediating cholesterol transportation and producing lysoPS. Furthermore, PLA1A is necessary for hepatitis C virus assembly and can play a role in the antivirus innate immune response. This review summarizes recent findings on PLA1A expression, lysoPS and lysoPS receptors in autoimmune disorders, cancers, cardiometabolic disorders, antivirus immune responses, as well as regulations of immune cells.
Collapse
Affiliation(s)
- Yang Zhao
- Centre de recherche du CHU de Québec-Université Laval, Centre ARThrite de l'Université Laval, Département de microbiologie-infectiologie et d'immunologie, Université Laval, Québec, G1V 4G2, Canada
| | - Stephan Hasse
- Centre de recherche du CHU de Québec-Université Laval, Centre ARThrite de l'Université Laval, Département de microbiologie-infectiologie et d'immunologie, Université Laval, Québec, G1V 4G2, Canada
| | - Sylvain G Bourgoin
- Centre de recherche du CHU de Québec-Université Laval, Centre ARThrite de l'Université Laval, Département de microbiologie-infectiologie et d'immunologie, Université Laval, Québec, G1V 4G2, Canada.
| |
Collapse
|
18
|
Current Knowledge on the Biology of Lysophosphatidylserine as an Emerging Bioactive Lipid. Cell Biochem Biophys 2021; 79:497-508. [PMID: 34129148 PMCID: PMC8551102 DOI: 10.1007/s12013-021-00988-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/16/2021] [Indexed: 01/22/2023]
Abstract
Lysophosphatidylserine (LysoPS) is an emerging lysophospholipid (LPL) mediator, which acts through G protein-coupled receptors, like lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P). LysoPS is detected in various tissues and cells and thought to be produced mainly by the deacylation of phosphatidylserine. LysoPS has been known to stimulate degranulation of mast cells. Recently, four LysoPS-specific G protein-coupled receptors (GPCRs) were identified. These GPCRs belong to the P2Y family which covers receptors for nucleotides and LPLs and are predominantly expressed in immune cells such as lymphocytes and macrophages. Studies on knockout mice of these GPCRs have revealed that LysoPS has immune-modulatory functions. Up-regulation of a LysoPS-producing enzyme, PS-specific phospholipase A1, was frequently observed in situations where the immune system is activated including autoimmune diseases and organ transplantations. Therefore, modulation of LysoPS signaling appears to be a promising method for providing therapies for the treatment of immune diseases. In this review, we summarize the biology of LysoPS-producing enzymes and receptors, recent developments in LysoPS signal modulators, and prospects for future therapeutic applications.
Collapse
|
19
|
The Lysophosphatidylserines-An Emerging Class of Signalling Lysophospholipids. J Membr Biol 2020; 253:381-397. [PMID: 32767057 DOI: 10.1007/s00232-020-00133-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 07/24/2020] [Indexed: 12/30/2022]
Abstract
Lysophospholipids are potent hormone-like signalling biological lipids that regulate many important biological processes in mammals (including humans). Lysophosphatidic acid and sphingosine-1-phosphate represent the best studied examples for this lipid class, and their metabolic enzymes and/or cognate receptors are currently under clinical investigation for treatment of various neurological and autoimmune diseases in humans. Over the past two decades, the lysophsophatidylserines (lyso-PSs) have emerged as yet another biologically important lysophospholipid, and deregulation in its metabolism has been linked to various human pathophysiological conditions. Despite its recent emergence, an exhaustive review summarizing recent advances on lyso-PSs and the biological pathways that this bioactive lysophospholipid regulates has been lacking. To address this, here, we summarize studies that led to the discovery of lyso-PS as a potent signalling biomolecule, and discuss the structure, its detection in biological systems, and the biodistribution of this lysophospholipid in various mammalian systems. Further, we describe in detail the enzymatic pathways that are involved in the biosynthesis and degradation of this lipid and the putative lyso-PS receptors reported in the literature. Finally, we discuss the various biological pathways directly regulated by lyso-PSs in mammals and prospect new questions for this still emerging biomedically important signalling lysophospholipid.
Collapse
|