1
|
Plumb RS, Gethings LA, Isaac G, Munjoma NC, Wilson ID. Detection of pharmacolipidodynamic effects following the intravenous and oral administration of gefitinib to C57Bl/6JRj mice by rapid UHPLC-MS analysis of plasma. Sci Rep 2024; 14:17061. [PMID: 39048625 PMCID: PMC11269747 DOI: 10.1038/s41598-024-66764-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Accepted: 07/03/2024] [Indexed: 07/27/2024] Open
Abstract
Omics-based biomarker technologies, including metabolic profiling (metabolomics/metabonomics) and lipidomics, are making a significant impact on disease understanding, drug development, and translational research. A wide range of patho-physiological processes involve lipids and monitoring changes in lipid abundance can give valuable insights into mechanisms of drug action, off target pharmacology and toxicity. Here we report changes, detected by untargeted LC-MS, in the plasma lipid profiles of male C57Bl/6JRj mice following the PO and IV administration of the epidermal growth factor receptor (EGFR) inhibitor gefitinib. Statistical analysis of the data obtained for both the IV and PO samples showed time-related changes in the amounts of lipids from several different classes. The largest effects were associated with a rapid onset of these changes following gefitinib administration followed by a gradual return by 24 h post dose to the type of lipid profile seen in predose samples. Investigation of the lipids responsible for the variance observed in the data showed that the PI, PC, LPC, PE and TG were subject to the largest disruption with both transient increases and decreases in relative amounts seen in response to administration of the drug. The pattern of the changes in the relative abundances of those lipids subject to variation appeared to be correlated to the pharmacokinetics of gefitinib (and its major metabolites). These observations support the concept of a distinct pharmacolipidodynamic relationship between drug exposure and plasma lipid abundance.
Collapse
Affiliation(s)
| | | | - Giorgis Isaac
- Program in Molecular Medicine, University of Massachusetts, Chan Medical School, 373 Plantation Street, Worcester, MA, 01605, USA
| | | | - Ian D Wilson
- Computational & Systems Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK.
| |
Collapse
|
2
|
Mehranfar M, Asadi P, Shokohi R, Milev MP, Gamberi C, Sacher M. Lipidomic analysis of human TANGO2-deficient cells suggests a lipid imbalance as a cause of TANGO2 deficiency disease. Biochem Biophys Res Commun 2024; 717:150047. [PMID: 38718569 DOI: 10.1016/j.bbrc.2024.150047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 04/17/2024] [Accepted: 05/01/2024] [Indexed: 05/21/2024]
Abstract
TANGO2 deficiency disease (TDD) is a multisystem disease caused by variants in the TANGO2 gene. Symptoms include neurodevelopmental delays, seizures and potentially lethal metabolic crises and cardiac arrhythmias. While the function of TANGO2 remains elusive, vitamin B5/pantothenic acid supplementation has been shown to alleviate symptoms in a fruit fly model and has also been used with success to treat individuals suffering from TDD. Since vitamin B5 is the precursor to the lipid activator coenzyme A (CoA), we hypothesized that TANGO2-deficient cells would display changes in the lipid profile compared to control and that these changes would be rescued by vitamin B5 supplementation. In addition, the specific changes seen might point to a pathway in which TANGO2 functions. Indeed, we found profound changes in the lipid profile of human TANGO2-deficient cells as well as an increased pool of free fatty acids in both human cells devoid of TANGO2 and Drosophila harboring a previously described TANGO2 loss of function allele. All these changes were reversed upon vitamin B5 supplementation. Pathway analysis showed significant increases in triglyceride as well as in lysophospholipid levels as the top enriched pathways in the absence of TANGO2. Consistent with a defect in triglyceride metabolism, we found changes in lipid droplet numbers and sizes in the absence of TANGO2 compared to control. Our data will allow for comparison between other model systems of TDD and the homing in on critical lipid imbalances that lead to the disease state.
Collapse
Affiliation(s)
- Mahsa Mehranfar
- Concordia University, Department of Chemistry and Biochemistry, Canada
| | - Paria Asadi
- Concordia University, Department of Biology, Canada
| | | | | | - Chiara Gamberi
- Coastal Carolina University, Department of Biology, United States
| | - Michael Sacher
- Concordia University, Department of Biology, Canada; McGill University, Department of Anatomy and Cell Biology, Canada.
| |
Collapse
|
3
|
Wang Y, Liu T, Wu Y, Wang L, Ding S, Hou B, Zhao H, Liu W, Li P. Lipid homeostasis in diabetic kidney disease. Int J Biol Sci 2024; 20:3710-3724. [PMID: 39113692 PMCID: PMC11302873 DOI: 10.7150/ijbs.95216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 06/21/2024] [Indexed: 08/10/2024] Open
Abstract
Lipid homeostasis is crucial for proper cellular and systemic functions. A growing number of studies confirm the importance of lipid homeostasis in diabetic kidney disease (DKD). Lipotoxicity caused by imbalance in renal lipid homeostasis can further exasperate renal injury. Large lipid deposits and lipid droplet accumulation are present in the kidneys of DKD patients. Autophagy plays a critical role in DKD lipid homeostasis and is involved in the regulation of lipid content. Inhibition or reduction of autophagy can lead to lipid accumulation, which in turn further affects autophagy. Lipophagy selectively recognizes and degrades lipids and helps to regulate cellular lipid metabolism and maintain intracellular lipid homeostasis. Therefore, we provide a systematic review of fatty acid, cholesterol, and sphingolipid metabolism, and discuss the responses of different renal intrinsic cells to imbalances in lipid homeostasis. Finally, we discuss the mechanism by which autophagy, especially lipophagy, maintains lipid homeostasis to support the development of new DKD drugs targeting lipid homeostasis.
Collapse
Affiliation(s)
- Ying Wang
- China-Japan Friendship Hospital, Institute of Medical Science, Beijing, China
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Tongtong Liu
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yun Wu
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Lin Wang
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Shaowei Ding
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Baoluo Hou
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Hailing Zhao
- China-Japan Friendship Hospital, Institute of Medical Science, Beijing, China
| | - Weijing Liu
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Ping Li
- China-Japan Friendship Hospital, Institute of Medical Science, Beijing, China
| |
Collapse
|
4
|
Chen Z, Yam JWP, Mao X. The multifaceted roles of small extracellular vesicles in metabolic reprogramming in the tumor microenvironments. Proteomics 2024; 24:e2300021. [PMID: 38171844 DOI: 10.1002/pmic.202300021] [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: 07/24/2023] [Revised: 11/13/2023] [Accepted: 11/14/2023] [Indexed: 01/05/2024]
Abstract
The link between metabolism and tumor progression has been extensively researched for a long time. With the increasing number of studies uncovering the multiple functions of metabolic reprogramming in tumor microenvironments, the regulatory network seems to become even more intricate at the same time. Small extracellular vesicles (sEV), as crucial mediators facilitating intercellular communications, exhibit significant involvement in regulating metabolic reprogramming within the complicated network of tumor microenvironments. sEV derived from tumor cells and those released by other cell populations such as tumor-associated macrophages (TAMs) and cancer-associated fibroblasts (CAFs) can mutually influence each other, giving rise to diverse complex feedback loops. This review includes multiple studies conducted in recent years to summarize the functions of sEV in altering metabolism in various cell types within tumor microenvironments. Additionally, it aims to highlight potential therapeutic targets based on the commonly observed mechanisms identified in different studies.
Collapse
Affiliation(s)
- Zhixian Chen
- Department of Pathology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Judy Wai Ping Yam
- Department of Pathology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Xiaowen Mao
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| |
Collapse
|
5
|
Evergren E, Mills IG, Kennedy G. Adaptations of membrane trafficking in cancer and tumorigenesis. J Cell Sci 2024; 137:jcs260943. [PMID: 38770683 PMCID: PMC11166456 DOI: 10.1242/jcs.260943] [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] [Indexed: 05/22/2024] Open
Abstract
Membrane trafficking, a fundamental cellular process encompassing the transport of molecules to specific organelles, endocytosis at the plasma membrane and protein secretion, is crucial for cellular homeostasis and signalling. Cancer cells adapt membrane trafficking to enhance their survival and metabolism, and understanding these adaptations is vital for improving patient responses to therapy and identifying therapeutic targets. In this Review, we provide a concise overview of major membrane trafficking pathways and detail adaptations in these pathways, including COPII-dependent endoplasmic reticulum (ER)-to-Golgi vesicle trafficking, COPI-dependent retrograde Golgi-to-ER trafficking and endocytosis, that have been found in cancer. We explore how these adaptations confer growth advantages or resistance to cell death and conclude by discussing the potential for utilising this knowledge in developing new treatment strategies and overcoming drug resistance for cancer patients.
Collapse
Affiliation(s)
- Emma Evergren
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Ian G. Mills
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford OX3 9DU, UK
| | - Grace Kennedy
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| |
Collapse
|
6
|
Lin TC, Chung PJ, Shen CA, Nguyen TMH, Lin YS, Lin SC, Hsiao SC, Chiu WT. Depletion of intracellular Ca 2+ induces FOXM1 SUMOylation and accumulation on the inner nuclear membrane and accelerates G2/M cell cycle transition. Eur J Cell Biol 2023; 102:151332. [PMID: 37302175 DOI: 10.1016/j.ejcb.2023.151332] [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: 12/18/2022] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/13/2023] Open
Abstract
Intracellular calcium (Ca2+) has been reported to regulate transcription factor activity and cancer development, but how it affects the function of Forkhead box protein M1 (FOXM1), a crucial transcription factor and key oncogene participating in tumorigenesis, remains unclear. Here, we investigated the regulatory role of Ca2+ on FOXM1 and found that Ca2+ depletion caused the distribution of FOXM1 to aggregate on the nuclear envelope, which was also observed in many cell lines. Further experiments revealed that sequestrated FOXM1 colocalized with lamin B in the inner nuclear membrane (INM) and was affected by the activity of nuclear export protein exportin 1 (XPO1). To investigate how intracellular Ca2+ affects FOXM1, we found that among the posttranscriptional modifications, only SUMOylation of FOXM1 showed a pronounced increase under reduced Ca2+, and suppressed SUMOylation rescued FOXM1 sequestration. In addition, Ca2+-dependent SUMOylated FOXM1 appeared to enhance the G2/M transition of the cell cycle and decrease cell apoptosis. In conclusion, our findings provide a molecular basis for the relationship between Ca2+ signaling and FOXM1 regulation, and we look to elucidate Ca2+-dependent FOXM1 SUMOylation-related biological functions in the future.
Collapse
Affiliation(s)
- Tzu-Chien Lin
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Ping-Jung Chung
- Department of Biomedical Engineering, College of Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - Chen-An Shen
- Department of Biomedical Engineering, College of Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - Thi My Hang Nguyen
- Department of Biomedical Engineering, College of Engineering, National Cheng Kung University, Tainan 701, Taiwan
| | - Yi-Syuan Lin
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Shih-Chieh Lin
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Shih-Chuan Hsiao
- Department of Hematology & Oncology, Saint Martin de Porres Hospital, Chiayi 600, Taiwan.
| | - Wen-Tai Chiu
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan; Department of Biomedical Engineering, College of Engineering, National Cheng Kung University, Tainan 701, Taiwan; Medical Device Innovation Center, National Cheng Kung University, Tainan 701, Taiwan.
| |
Collapse
|
7
|
Vallés AS, Barrantes FJ. The synaptic lipidome in health and disease. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:184033. [PMID: 35964712 DOI: 10.1016/j.bbamem.2022.184033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 08/02/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
Adequate homeostasis of lipid, protein and carbohydrate metabolism is essential for cells to perform highly specific tasks in our organism, and the brain, with its uniquely high energetic requirements, posesses singular characteristics. Some of these are related to its extraordinary dotation of synapses, the specialized subcelluar structures where signal transmission between neurons occurs in the central nervous system. The post-synaptic compartment of excitatory synapses, the dendritic spine, harbors key molecules involved in neurotransmission tightly packed within a minute volume of a few femtoliters. The spine is further compartmentalized into nanodomains that facilitate the execution of temporo-spatially separate functions in the synapse. Lipids play important roles in this structural and functional compartmentalization and in mechanisms that impact on synaptic transmission. This review analyzes the structural and dynamic processes involving lipids at the synapse, highlighting the importance of their homeostatic balance for the physiology of this complex and highly specialized structure, and underscoring the pathologies associated with disbalances of lipid metabolism, particularly in the perinatal and late adulthood periods of life. Although small variations of the lipid profile in the brain take place throughout the adult lifespan, the pathophysiological consequences are clinically manifested mostly during late adulthood. Disturbances in lipid homeostasis in the perinatal period leads to alterations during nervous system development, while in late adulthood they favor the occurrence of neurodegenerative diseases.
Collapse
Affiliation(s)
- Ana Sofia Vallés
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (UNS-CONICET), 8000 Bahía Blanca, Argentina.
| | - Francisco J Barrantes
- Laboratory of Molecular Neurobiology, Institute of Biomedical Research (BIOMED), UCA-CONICET, Av. Alicia Moreau de Justo 1600, Buenos Aires C1107AAZ, Argentina.
| |
Collapse
|
8
|
Westra M, Gutierrez Y, MacGillavry HD. Contribution of Membrane Lipids to Postsynaptic Protein Organization. Front Synaptic Neurosci 2021; 13:790773. [PMID: 34887741 PMCID: PMC8649999 DOI: 10.3389/fnsyn.2021.790773] [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: 10/07/2021] [Accepted: 11/02/2021] [Indexed: 11/13/2022] Open
Abstract
The precise subsynaptic organization of proteins at the postsynaptic membrane controls synaptic transmission. In particular, postsynaptic receptor complexes are concentrated in distinct membrane nanodomains to optimize synaptic signaling. However, despite the clear functional relevance of subsynaptic receptor organization to synaptic transmission and plasticity, the mechanisms that underlie the nanoscale organization of the postsynaptic membrane remain elusive. Over the last decades, the field has predominantly focused on the role of protein-protein interactions in receptor trafficking and positioning in the synaptic membrane. In contrast, the contribution of lipids, the principal constituents of the membrane, to receptor positioning at the synapse remains poorly understood. Nevertheless, there is compelling evidence that the synaptic membrane is enriched in specific lipid species and that deregulation of lipid homeostasis in neurons severely affects synaptic functioning. In this review we focus on how lipids are organized at the synaptic membrane, with special emphasis on how current models of membrane organization could contribute to protein distribution at the synapse and synaptic transmission. Finally, we will present an outlook on how novel technical developments could be applied to study the dynamic interplay between lipids and proteins at the postsynaptic membrane.
Collapse
Affiliation(s)
- Manon Westra
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | - Yolanda Gutierrez
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | - Harold D MacGillavry
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands
| |
Collapse
|
9
|
Cruz-Gregorio A, Aranda-Rivera AK, Ortega-Lozano AJ, Pedraza-Chaverri J, Mendoza-Hoffmann F. Lipid metabolism and oxidative stress in HPV-related cancers. Free Radic Biol Med 2021; 172:226-236. [PMID: 34129929 DOI: 10.1016/j.freeradbiomed.2021.06.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 05/21/2021] [Accepted: 06/10/2021] [Indexed: 02/06/2023]
Abstract
High-risk human papillomavirus (HR-HPVs) are associated with the development of cervical, anus, vagina, vulva, penis, and oropharynx cancer. HR-HPVs target and modify the function of different cell biomolecules such as glucose, amino acids, lipids, among others. The latter induce cell proliferation, cell death evasion, and genomic instability resulting in cell transformation. Moreover, lipids are essential biomolecules in HR-HPVs infection and cell vesicular trafficking. They are also critical in producing cellular energy, the epithelial-mesenchymal transition (EMT) process, and therapy resistance of HPV-related cancers. HPV proteins induce oxidative stress (OS), which in turn promotes lipid peroxidation and cell damage, resulting in cell death such as apoptosis, autophagy, and ferroptosis. HR-HPV-related cancer cells cope with OS and lipid peroxidation, preventing cell death; however, these cells are sensitized by OS, which could be used as a target for redox therapies to induce their elimination. This review focuses on the role of lipids in HR-HPV infection and HPV-related cancer development, maintenance, resistance to therapy, and the possible treatments associated with lipids. Furthermore, we emphasize the significant role of OS in lipid peroxidation to induce cell death through apoptosis, autophagy, and ferroptosis to eliminate HPV-related cancers.
Collapse
Affiliation(s)
- Alfredo Cruz-Gregorio
- Laboratorio F-225, Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico.
| | - Ana Karina Aranda-Rivera
- Laboratorio F-315, Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico; Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México 04510, Mexico.
| | - Ariadna Jazmin Ortega-Lozano
- Laboratorio F-315, Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico.
| | - José Pedraza-Chaverri
- Laboratorio F-315, Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico.
| | - Francisco Mendoza-Hoffmann
- IHuman Institute, ShanghaiTech University, China; Laboratorio F-206, Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico.
| |
Collapse
|
10
|
Tayyrov A, Wei C, Fetz C, Goryachkin A, Schächle P, Nyström L, Künzler M. Cytoplasmic Lipases-A Novel Class of Fungal Defense Proteins Against Nematodes. FRONTIERS IN FUNGAL BIOLOGY 2021; 2:696972. [PMID: 37744157 PMCID: PMC10512399 DOI: 10.3389/ffunb.2021.696972] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 05/31/2021] [Indexed: 09/26/2023]
Abstract
Fungi are an attractive food source for predators such as fungivorous nematodes. Several fungal defense proteins and their protective mechanisms against nematodes have been described. Many of these proteins are lectins which are stored in the cytoplasm of the fungal cells and bind to specific glycan epitopes in the digestive tract of the nematode upon ingestion. Here, we studied two novel nematotoxic proteins with lipase domains from the model mushroom Coprinopsis cinerea. These cytoplasmically localized proteins were found to be induced in the vegetative mycelium of C. cinerea upon challenge with fungivorous nematode Aphelenchus avenae. The proteins showed nematotoxicity when heterologously expressed in E. coli and fed to several bacterivorous nematodes. Site-specific mutagenesis of predicted catalytic residues eliminated the in-vitro lipase activity of the proteins and significantly reduced their nematotoxicity, indicating the importance of the lipase activity for the nematotoxicity of these proteins. Our results suggest that cytoplasmic lipases constitute a novel class of fungal defense proteins against predatory nematodes. These findings improve our understanding of fungal defense mechanisms against predators and may find applications in the control of parasitic nematodes in agriculture and medicine.
Collapse
Affiliation(s)
- Annageldi Tayyrov
- Department of Biology, Institute of Microbiology, ETH Zürich, Zurich, Switzerland
| | - Chunyue Wei
- Department of Health Sciences and Technology, Institute of Food, Nutrition and Health, ETH Zürich, Zurich, Switzerland
| | - Céline Fetz
- Department of Biology, Institute of Microbiology, ETH Zürich, Zurich, Switzerland
| | - Aleksandr Goryachkin
- Department of Biology, Institute of Microbiology, ETH Zürich, Zurich, Switzerland
| | - Philipp Schächle
- Department of Biology, Institute of Microbiology, ETH Zürich, Zurich, Switzerland
| | - Laura Nyström
- Department of Health Sciences and Technology, Institute of Food, Nutrition and Health, ETH Zürich, Zurich, Switzerland
| | - Markus Künzler
- Department of Biology, Institute of Microbiology, ETH Zürich, Zurich, Switzerland
| |
Collapse
|
11
|
Huda MN, Nafiujjaman M, Deaguero IG, Okonkwo J, Hill ML, Kim T, Nurunnabi M. Potential Use of Exosomes as Diagnostic Biomarkers and in Targeted Drug Delivery: Progress in Clinical and Preclinical Applications. ACS Biomater Sci Eng 2021; 7:2106-2149. [PMID: 33988964 PMCID: PMC8147457 DOI: 10.1021/acsbiomaterials.1c00217] [Citation(s) in RCA: 99] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 05/03/2021] [Indexed: 12/13/2022]
Abstract
Exosomes are cell-derived vesicles containing heterogeneous active biomolecules such as proteins, lipids, mRNAs, receptors, immune regulatory molecules, and nucleic acids. They typically range in size from 30 to 150 nm in diameter. An exosome's surfaces can be bioengineered with antibodies, fluorescent dye, peptides, and tailored for small molecule and large active biologics. Exosomes have enormous potential as a drug delivery vehicle due to enhanced biocompatibility, excellent payload capability, and reduced immunogenicity compared to alternative polymeric-based carriers. Because of active targeting and specificity, exosomes are capable of delivering their cargo to exosome-recipient cells. Additionally, exosomes can potentially act as early stage disease diagnostic tools as the exosome carries various protein biomarkers associated with a specific disease. In this review, we summarize recent progress on exosome composition, biological characterization, and isolation techniques. Finally, we outline the exosome's clinical applications and preclinical advancement to provide an outlook on the importance of exosomes for use in targeted drug delivery, biomarker study, and vaccine development.
Collapse
Affiliation(s)
- Md Nurul Huda
- Environmental Science & Engineering, University of Texas at El Paso, El Paso, TX 79968
| | - Md Nafiujjaman
- Department of Biomedical Engineering, Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI 48824
| | - Isaac G Deaguero
- Biomedical Engineering, University of Texas at El Paso, El Paso, TX 79968
| | - Jude Okonkwo
- John A Paulson School of Engineering, Harvard University, Cambridge, MA 02138
| | - Meghan L. Hill
- Department of Biomedical Engineering, Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI 48824
| | - Taeho Kim
- Department of Biomedical Engineering, Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI 48824
| | - Md Nurunnabi
- Environmental Science & Engineering, University of Texas at El Paso, El Paso, TX 79968
- Biomedical Engineering, University of Texas at El Paso, El Paso, TX 79968
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Texas at El Paso, El Paso, TX 79902
- Border Biomedical Research Center, University of Texas at El Paso, El Paso, TX 79968
| |
Collapse
|
12
|
Pan PY, Zhu J, Rizvi A, Zhu X, Tanaka H, Dreyfus CF. Synaptojanin1 deficiency upregulates basal autophagosome formation in astrocytes. J Biol Chem 2021; 297:100873. [PMID: 34126070 PMCID: PMC8258991 DOI: 10.1016/j.jbc.2021.100873] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/02/2021] [Accepted: 06/10/2021] [Indexed: 01/07/2023] Open
Abstract
Macroautophagy dysregulation is implicated in multiple neurological disorders, such as Parkinson's disease. While autophagy pathways are heavily researched in heterologous cells and neurons, regulation of autophagy in the astrocyte, the most abundant cell type in the mammalian brain, is less well understood. Missense mutations in the Synj1 gene encoding Synaptojanin1 (Synj1), a neuron-enriched lipid phosphatase, have been linked to Parkinsonism with seizures. Our previous study showed that the Synj1 haploinsufficient (Synj1+/−) mouse exhibits age-dependent autophagy impairment in multiple brain regions. Here, we used cultured astrocytes from Synj1-deficient mice to investigate its role in astrocyte autophagy. We report that Synj1 is expressed in low levels in astrocytes and represses basal autophagosome formation. We demonstrate using cellular imaging that Synj1-deficient astrocytes exhibit hyperactive autophagosome formation, represented by an increase in the size and number of GFP-microtubule-associated protein 1A/1B-light chain 3 structures. Interestingly, Synj1 deficiency is also associated with an impairment in stress-induced autophagy clearance. We show, for the first time, that the Parkinsonism-associated R839C mutation impacts autophagy in astrocytes. The impact of this mutation on the phosphatase function of Synj1 resulted in elevated basal autophagosome formation that mimics Synj1 deletion. We found that the membrane expression of the astrocyte-specific glucose transporter GluT-1 was reduced in Synj1-deficient astrocytes. Consistently, AMP-activated protein kinase activity was elevated, suggesting altered glucose sensing in Synj1-deficient astrocytes. Expressing exogenous GluT-1 in Synj1-deficient astrocytes reversed the autophagy impairment, supporting a role for Synj1 in regulating astrocyte autophagy via disrupting glucose-sensing pathways. Thus, our work suggests a novel mechanism for Synj1-related Parkinsonism involving astrocyte dysfunction.
Collapse
Affiliation(s)
- Ping-Yue Pan
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA.
| | - Justin Zhu
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Asma Rizvi
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Xinyu Zhu
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Hikari Tanaka
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Cheryl F Dreyfus
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| |
Collapse
|
13
|
Main A, Fuller W. Protein S-Palmitoylation: advances and challenges in studying a therapeutically important lipid modification. FEBS J 2021; 289:861-882. [PMID: 33624421 DOI: 10.1111/febs.15781] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 02/01/2021] [Accepted: 02/22/2021] [Indexed: 12/11/2022]
Abstract
The lipid post-translational modification S-palmitoylation is a vast developing field, with the modification itself and the enzymes that catalyse the reversible reaction implicated in a number of diseases. In this review, we discuss the past and recent advances in the experimental tools used in this field, including pharmacological tools, animal models and techniques to understand how palmitoylation controls protein localisation and function. Additionally, we discuss the obstacles to overcome in order to advance the field, particularly to the point at which modulating palmitoylation may be achieved as a therapeutic strategy.
Collapse
Affiliation(s)
- Alice Main
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, UK
| | - William Fuller
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, UK
| |
Collapse
|
14
|
Weber F, Ivan DC, Proulx ST, Locatelli G, Aleandri S, Luciani P. Beyond Trial and Error: A Systematic Development of Liposomes Targeting Primary Macrophages. ADVANCED NANOBIOMED RESEARCH 2021. [DOI: 10.1002/anbr.202000098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Florian Weber
- Department of Chemistry Biochemistry and Pharmaceutical Sciences University of Bern Bern 3012 Switzerland
| | - Daniela C. Ivan
- Theodor Kocher Institute University of Bern Bern 3012 Switzerland
| | - Steven T. Proulx
- Theodor Kocher Institute University of Bern Bern 3012 Switzerland
| | | | - Simone Aleandri
- Department of Chemistry Biochemistry and Pharmaceutical Sciences University of Bern Bern 3012 Switzerland
| | - Paola Luciani
- Department of Chemistry Biochemistry and Pharmaceutical Sciences University of Bern Bern 3012 Switzerland
| |
Collapse
|
15
|
Xu J, Taubert S. Beyond Proteostasis: Lipid Metabolism as a New Player in ER Homeostasis. Metabolites 2021; 11:52. [PMID: 33466824 PMCID: PMC7830277 DOI: 10.3390/metabo11010052] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/04/2021] [Accepted: 01/11/2021] [Indexed: 12/12/2022] Open
Abstract
Biological membranes are not only essential barriers that separate cellular and subcellular structures, but also perform other critical functions such as the initiation and propagation of intra- and intercellular signals. Each membrane-delineated organelle has a tightly regulated and custom-made membrane lipid composition that is critical for its normal function. The endoplasmic reticulum (ER) consists of a dynamic membrane network that is required for the synthesis and modification of proteins and lipids. The accumulation of unfolded proteins in the ER lumen activates an adaptive stress response known as the unfolded protein response (UPR-ER). Interestingly, recent findings show that lipid perturbation is also a direct activator of the UPR-ER, independent of protein misfolding. Here, we review proteostasis-independent UPR-ER activation in the genetically tractable model organism Caenorhabditis elegans. We review the current knowledge on the membrane lipid composition of the ER, its impact on organelle function and UPR-ER activation, and its potential role in human metabolic diseases. Further, we summarize the bi-directional interplay between lipid metabolism and the UPR-ER. We discuss recent progress identifying the different respective mechanisms by which disturbed proteostasis and lipid bilayer stress activate the UPR-ER. Finally, we consider how genetic and metabolic disturbances may disrupt ER homeostasis and activate the UPR and discuss how using -omics-type analyses will lead to more comprehensive insights into these processes.
Collapse
Affiliation(s)
- Jiaming Xu
- Graduate Program in Cell and Developmental Biology, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada;
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, BC V5Z 4H4, Canada
- Healthy Starts Theme, British Columbia Children’s Hospital Research Institute, Vancouver, BC V5Z 4H4, Canada
| | - Stefan Taubert
- Graduate Program in Cell and Developmental Biology, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada;
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, BC V5Z 4H4, Canada
- Healthy Starts Theme, British Columbia Children’s Hospital Research Institute, Vancouver, BC V5Z 4H4, Canada
- Department of Medical Genetics, The University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| |
Collapse
|
16
|
Delarocque J, Frers F, Feige K, Huber K, Jung K, Warnken T. Metabolic changes induced by oral glucose tests in horses and their diagnostic use. J Vet Intern Med 2020; 35:597-605. [PMID: 33277752 PMCID: PMC7848347 DOI: 10.1111/jvim.15992] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 11/16/2020] [Accepted: 11/20/2020] [Indexed: 12/15/2022] Open
Abstract
Background Little is known about the implications of hyperinsulinemia on energy metabolism, and such knowledge might help understand the pathophysiology of insulin dysregulation. Objectives Describe differences in the metabolic response to an oral glucose test, depending on the magnitude of the insulin response. Animals Twelve Icelandic horses in various metabolic states. Methods Horses were subjected to 3 oral glucose tests (OGT; 0.5 g/kg body weight glucose). Basal, 120 and 180 minutes samples were analyzed using a combined liquid chromatography tandem mass spectrometry and flow injection analysis tandem mass spectrometry metabolomic assay. Insulin concentrations were measured using an ELISA. Analysis was performed using linear models and partial least‐squares regression. Results The kynurenine : tryptophan ratio increased over time during the OGT (adjusted P‐value = .001). A high insulin response was associated with lower arginine (adjusted P‐value = .02) and carnitine (adjusted P‐value = .03) concentrations. A predictive model using only baseline samples performed well with as few as 7 distinct metabolites (sensitivity, 86%; 95% confidence interval [CI], 81%‐90%; specificity, 88%; 95% CI, 84%‐92%). Conclusions and Clinical Importance Our results suggest induction of low‐grade inflammation during the OGT. Plasma arginine and carnitine concentrations were lower in horses with high insulin response and could constitute potential therapeutic targets. Development of screening tools to identify insulin‐dysregulated horses using only baseline blood sample appears promising.
Collapse
Affiliation(s)
- Julien Delarocque
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hanover, Germany
| | - Florian Frers
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hanover, Germany
| | - Karsten Feige
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hanover, Germany
| | - Korinna Huber
- Institute of Animal Science, Faculty of Agricultural Sciences, University of Hohenheim, Stuttgart, Germany
| | - Klaus Jung
- Institute for Animal Breeding and Genetics, University of Veterinary Medicine Hannover, Foundation, Hanover, Germany
| | - Tobias Warnken
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hanover, Germany
| |
Collapse
|
17
|
Allen PE, Martinez JJ. Modulation of Host Lipid Pathways by Pathogenic Intracellular Bacteria. Pathogens 2020; 9:pathogens9080614. [PMID: 32731350 PMCID: PMC7460438 DOI: 10.3390/pathogens9080614] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 07/17/2020] [Accepted: 07/25/2020] [Indexed: 12/22/2022] Open
Abstract
Lipids are a broad group of molecules required for cell maintenance and homeostasis. Various intracellular pathogens have developed mechanisms of modulating and sequestering host lipid processes for a large array of functions for both bacterial and host cell survival. Among the host cell lipid functions that intracellular bacteria exploit for infection are the modulation of host plasma membrane microdomains (lipid rafts) required for efficient bacterial entry; the recruitment of specific lipids for membrane integrity of intracellular vacuoles; and the utilization of host lipid droplets for the regulation of immune responses and for energy production through fatty acid β-oxidation and oxidative phosphorylation. The majority of published studies on the utilization of these host lipid pathways during infection have focused on intracellular bacterial pathogens that reside within a vacuole during infection and, thus, have vastly different requirements for host lipid metabolites when compared to those intracellular pathogens that are released into the host cytosol upon infection. Here we summarize the mechanisms by which intracellular bacteria sequester host lipid species and compare the modulation of host lipid pathways and metabolites during host cell infection by intracellular pathogens residing in either a vacuole or within the cytosol of infected mammalian cells. This review will also highlight common and unique host pathways necessary for intracellular bacterial growth that could potentially be targeted for therapeutic intervention.
Collapse
|
18
|
Hou B, Zhao Y, He P, Xu C, Ma P, Lam SM, Li B, Gil V, Shui G, Qiang G, Liew CW, Du G. Targeted lipidomics and transcriptomics profiling reveal the heterogeneity of visceral and subcutaneous white adipose tissue. Life Sci 2020; 245:117352. [PMID: 32006527 DOI: 10.1016/j.lfs.2020.117352] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 01/14/2020] [Accepted: 01/22/2020] [Indexed: 01/04/2023]
Abstract
AIMS The depot-specific differences in lipidome of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) reflect heterogeneity of white adipose tissue (WAT), which plays a central role in its distinct response to outside stimuli. However, the detailed lipidome of depot-specific WAT is largely unknown, especially the minor constitutes including phospholipid and sphingolipid. MATERIALS AND METHODS To investigate this field, we applied a high-coverage targeted lipidomics approach of VAT and SAT in male C57BL/6J mice to compare the basal level of their lipid profiles. Applying microarray and quantitative real-time polymerase chain reaction, we analyzed the transcriptome of twodepot-specific WAT and verified the differences in individual genes. KEY FINDINGS In total, 342 lipid species from 19 lipid classes were identified. Our results showed the composition of TAG and FFA were different in length of chain and saturation. Interestingly, low abundance phospholipid, sphingolipid and cardiolipin were significantly higher in SAT. Lipid correlation network analysis vindicated that TAG and phospholipid formed distinct subnet and had more connections with other lipid species. Enriched ontology analysis of gene screened from LIPID MAPS and microarray suggested the differences were mainly involved in lipid metabolism, insulin resistance and inflammatory response. SIGNIFICANCE Our comprehensive lipidomics and transcriptomics analyses revealed differences in lipid composition and lipid metabolism of two depot-specific WAT, which would offer new insights into the investigation of heterogeneity of visceral and subcutaneous white adipose tissue.
Collapse
Affiliation(s)
- Biyu Hou
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College and Beijing Key Laboratory of Drug Target and Screening Research, Beijing 100050, China
| | - Yan Zhao
- Qingdao Municipal Hospital, Qingdao 266011, China
| | - Ping He
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College and Beijing Key Laboratory of Drug Target and Screening Research, Beijing 100050, China
| | - Chunyang Xu
- Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing 100026, China
| | - Peng Ma
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College and Beijing Key Laboratory of Drug Target and Screening Research, Beijing 100050, China
| | - Sin Man Lam
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bowen Li
- LipidALL Technologies Ltd., Changzhou, China
| | - Victoria Gil
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, 60612, IL, USA
| | - Guanghou Shui
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Guifen Qiang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College and Beijing Key Laboratory of Drug Target and Screening Research, Beijing 100050, China.
| | - Chong Wee Liew
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, 60612, IL, USA.
| | - Guanhua Du
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College and Beijing Key Laboratory of Drug Target and Screening Research, Beijing 100050, China.
| |
Collapse
|
19
|
Wang H, Zhang C, Xiao H. Mechanism of membrane fusion: protein-protein interaction and beyond. INTERNATIONAL JOURNAL OF PHYSIOLOGY, PATHOPHYSIOLOGY AND PHARMACOLOGY 2019; 11:250-257. [PMID: 31993099 PMCID: PMC6971501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 11/20/2019] [Indexed: 06/10/2023]
Abstract
Membrane fusion is a universal event in all living organism. It is at the heart of intracellular organelle biogenesis and membrane traffic processes such as endocytosis and exocytosis, and is also used by enveloped viruses to enter hosting cells. Regarding the cellular mechanisms underlying membrane fusion, pioneering studies by Randy Schekman, James Rothman, Thomas C. Südhof and their colleagues have demonstrated the function of specific proteins and protein-protein interactions as essential fusogenic factor to initiate membrane fusion. Since then, function of lipids and protein-lipid interaction has also been identified as important players in membrane fusion. Based on that NSF (NEM-sensitive factor where NEM stands for N-ethyl-maleimide) and acyl-CoA are required for the membrane fusion of transporting vesicles with Golgi cisternae, it is further suggested that the transfer of the acyl chain to a molecule(s) is essential for membrane fusion. Among the previously identified fusogens, phosphatidic acid (PA) is found as an acyl chain recipient. Functionally, acylation of PA is required for tethering the membranes of Rab5a vesicles and early endosomes together during membrane fusion. As certain threshold of proximity between the donor and acceptor membrane is required to initiate membrane fusion, fusogenic factors beyond protein-protein and protein-lipid interaction need to be identified.
Collapse
Affiliation(s)
- Hongbing Wang
- Department of Physiology, Michigan State UniversityEast Lansing, Michigan 48824, USA
- Neuroscience Program, Michigan State UniversityEast Lansing, Michigan 48824, USA
| | - Chengliang Zhang
- Department of Physiology, Michigan State UniversityEast Lansing, Michigan 48824, USA
| | - Hua Xiao
- Department of Physiology, Michigan State UniversityEast Lansing, Michigan 48824, USA
| |
Collapse
|
20
|
Zhukovsky MA, Filograna A, Luini A, Corda D, Valente C. Phosphatidic acid in membrane rearrangements. FEBS Lett 2019; 593:2428-2451. [PMID: 31365767 DOI: 10.1002/1873-3468.13563] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 12/16/2022]
Abstract
Phosphatidic acid (PA) is the simplest cellular glycerophospholipid characterized by unique biophysical properties: a small headgroup; negative charge; and a phosphomonoester group. Upon interaction with lysine or arginine, PA charge increases from -1 to -2 and this change stabilizes protein-lipid interactions. The biochemical properties of PA also allow interactions with lipids in several subcellular compartments. Based on this feature, PA is involved in the regulation and amplification of many cellular signalling pathways and functions, as well as in membrane rearrangements. Thereby, PA can influence membrane fusion and fission through four main mechanisms: it is a substrate for enzymes producing lipids (lysophosphatidic acid and diacylglycerol) that are involved in fission or fusion; it contributes to membrane rearrangements by generating negative membrane curvature; it interacts with proteins required for membrane fusion and fission; and it activates enzymes whose products are involved in membrane rearrangements. Here, we discuss the biophysical properties of PA in the context of the above four roles of PA in membrane fusion and fission.
Collapse
Affiliation(s)
- Mikhail A Zhukovsky
- Institute of Protein Biochemistry and Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| | - Angela Filograna
- Institute of Protein Biochemistry and Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| | - Alberto Luini
- Institute of Protein Biochemistry and Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| | - Daniela Corda
- Institute of Protein Biochemistry and Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| | - Carmen Valente
- Institute of Protein Biochemistry and Institute of Biochemistry and Cell Biology, National Research Council, Naples, Italy
| |
Collapse
|
21
|
de la Ballina LR, Munson MJ, Simonsen A. Lipids and Lipid-Binding Proteins in Selective Autophagy. J Mol Biol 2019; 432:135-159. [PMID: 31202884 DOI: 10.1016/j.jmb.2019.05.051] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/29/2019] [Accepted: 05/29/2019] [Indexed: 02/07/2023]
Abstract
Eukaryotic cells have the capacity to degrade intracellular components through a lysosomal degradation pathway called macroautophagy (henceforth referred to as autophagy) in which superfluous or damaged cytosolic entities are engulfed and separated from the rest of the cell constituents into double membraned vesicles known as autophagosomes. Autophagosomes then fuse with endosomes and lysosomes, where cargo is broken down into basic building blocks that are released to the cytoplasm for the cell to reuse. Autophagic degradation can target either cytoplasmic material in bulk (non-selective autophagy) or particular cargo in what is called selective autophagy. Proper autophagic turnover requires the orchestrated participation of several players that need to be tightly and temporally coordinated. Whereas a large number of autophagy-related (ATG) proteins have been identified and their functions and regulation are starting to be understood, there is substantially less knowledge regarding the specific lipids constituting the autophagic membranes as well as their role in initiating, enabling or regulating the autophagic process. This review focuses on lipids and their corresponding binding proteins that are crucial in the process of selective autophagy.
Collapse
Affiliation(s)
- Laura R de la Ballina
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway; Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Michael J Munson
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway; Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Anne Simonsen
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway; Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
| |
Collapse
|
22
|
Spatiotemporal Control of Lipid Conversion, Actin-Based Mechanical Forces, and Curvature Sensors during Clathrin/AP-1-Coated Vesicle Biogenesis. Cell Rep 2018; 20:2087-2099. [PMID: 28854360 DOI: 10.1016/j.celrep.2017.08.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 06/29/2017] [Accepted: 07/31/2017] [Indexed: 01/03/2023] Open
Abstract
Clathrin/adaptor protein-1-coated carriers connect the secretory and the endocytic pathways. Carrier biogenesis relies on distinct protein networks changing membrane shape at the trans-Golgi network, each regulating coat assembly, F-actin-based mechanical forces, or the biophysical properties of lipid bilayers. How these different hubs are spatiotemporally coordinated remains largely unknown. Using in vitro reconstitution systems, quantitative proteomics, and lipidomics, as well as in vivo cell-based assays, we characterize the protein networks controlling membrane lipid composition, membrane shape, and carrier scission. These include PIP5K1A and phospholipase C-beta 3 controlling the conversion of PI[4]P into diacylglycerol. PIP5K1A binding to RAC1 provides a link to F-actin-based mechanical forces needed to tubulate membranes. Tubular membranes then recruit the BAR-domain-containing arfaptin-1/2 guiding carrier scission. These findings provide a framework for synchronizing the chemical/biophysical properties of lipid bilayers, F-actin-based mechanical forces, and the activity of proteins sensing membrane shape during clathrin/adaptor protein-1-coated carrier biogenesis.
Collapse
|
23
|
In situ detecting changes in membrane lipid phenotypes of macrophages cultured in different cancer microenvironments using mass spectrometry. Anal Chim Acta 2018; 1026:101-108. [PMID: 29852985 DOI: 10.1016/j.aca.2018.04.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 04/13/2018] [Accepted: 04/14/2018] [Indexed: 12/16/2022]
Abstract
Macrophages, the important cells of immune system, have exhibited distinct gene phenotypes with diverse functions in different microenvironments. In the present study, macrophages RAW264.7 (M0 macrophages) and lipopolysaccharide (LPS) plus interferon gamma (INF-γ)-treated M0 macrophages (M1 macrophages) were cultured in different lung cell-derived culture supernatants (CSs) as imitative tumor microenvironments. The lipids (mainly from cell membrane) of intact macrophages were in situ detected by matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry. Approximately 300 of small molecules were observed in negative ion mode. Partial least square-discriminant analysis (PLS-DA) suggested that two types of the macrophages have different membrane lipid phenotypes. Changes in the levels of phosphatidylethanolamine PE(16:1/18:0), PE(18:1/18:0), PE(36:2), PE-Cer(d36:1), and PE(P-16:0/18:1) were closely associated with membrane phenotypes of macrophages. The heatmap also revealed that directional induction to classically activated macrophages (M1 macrophages) in vitro had greater impact on the membrane lipid phenotypes of macrophages than different lung cell-derived CSs. The results are consistent with the data obtained by biological technologies.
Collapse
|
24
|
Krčková Z, Kocourková D, Daněk M, Brouzdová J, Pejchar P, Janda M, Pokotylo I, Ott PG, Valentová O, Martinec J. The Arabidopsis thaliana non-specific phospholipase C2 is involved in the response to Pseudomonas syringae attack. ANNALS OF BOTANY 2018; 121:297-310. [PMID: 29300825 PMCID: PMC5808806 DOI: 10.1093/aob/mcx160] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 10/24/2017] [Indexed: 05/20/2023]
Abstract
Background and Aims The non-specific phospholipase C (NPC) is a new member of the plant phospholipase family that reacts to abiotic environmental stresses, such as phosphate deficiency, high salinity, heat and aluminium toxicity, and is involved in root development, silicon distribution and brassinolide signalling. Six NPC genes (NPC1-NPC6) are found in the Arabidopsis genome. The NPC2 isoform has not been experimentally characterized so far. Methods The Arabidopsis NPC2 isoform was cloned and heterologously expressed in Escherichia coli. NPC2 enzyme activity was determined using fluorescent phosphatidylcholine as a substrate. Tissue expression and subcellular localization were analysed using GUS- and GFP-tagged NPC2. The expression patterns of NPC2 were analysed via quantitative real-time PCR. Independent homozygous transgenic plant lines overexpressing NPC2 under the control of a 35S promoter were generated, and reactive oxygen species were measured using a luminol-based assay. Key Results The heterologously expressed protein possessed phospholipase C activity, being able to hydrolyse phosphatidylcholine to diacylglycerol. NPC2 tagged with GFP was predominantly localized to the Golgi apparatus in Arabidopsis roots. The level of NPC2 transcript is rapidly altered during plant immune responses and correlates with the activation of multiple layers of the plant defence system. Transcription of NPC2 decreased substantially after plant infiltration with Pseudomonas syringae, flagellin peptide flg22 and salicylic acid treatments and expression of the effector molecule AvrRpm1. The decrease in NPC2 transcript levels correlated with a decrease in NPC2 enzyme activity. NPC2-overexpressing mutants showed higher reactive oxygen species production triggered by flg22. Conclusions This first experimental characterization of NPC2 provides new insights into the role of the non-specific phospholipase C protein family. The results suggest that NPC2 is involved in the response of Arabidopsis to P. syringae attack.
Collapse
Affiliation(s)
- Zuzana Krčková
- Institute of Experimental Botany of the Czech Academy of Sciences, Czech Republic
| | - Daniela Kocourková
- Institute of Experimental Botany of the Czech Academy of Sciences, Czech Republic
| | - Michal Daněk
- Institute of Experimental Botany of the Czech Academy of Sciences, Czech Republic
| | - Jitka Brouzdová
- Institute of Experimental Botany of the Czech Academy of Sciences, Czech Republic
| | - Přemysl Pejchar
- Institute of Experimental Botany of the Czech Academy of Sciences, Czech Republic
| | - Martin Janda
- Institute of Experimental Botany of the Czech Academy of Sciences, Czech Republic
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Czech Republic
| | - Igor Pokotylo
- The Institute of Bioorganic Chemistry and Petrochemistry, National Academy of Sciences of Ukraine, Ukraine
| | - Peter G Ott
- Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Hungary
| | - Olga Valentová
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Czech Republic
| | - Jan Martinec
- Institute of Experimental Botany of the Czech Academy of Sciences, Czech Republic
| |
Collapse
|
25
|
Aznar N, Sun N, Dunkel Y, Ear J, Buschman MD, Ghosh P. A Daple-Akt feed-forward loop enhances noncanonical Wnt signals by compartmentalizing β-catenin. Mol Biol Cell 2017; 28:3709-3723. [PMID: 29021338 PMCID: PMC5706997 DOI: 10.1091/mbc.e17-06-0405] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 08/04/2017] [Accepted: 10/06/2017] [Indexed: 01/12/2023] Open
Abstract
Balance between canonical and noncanonical Wnt pathways controls the β-catenin transcriptional program; how the noncanonical pathway antagonizes the canonical pathway remains unclear. We show that Daple, an enhancer of noncanonical Wnt signals, accomplishes that goal by dictating the subcellular distribution of β-catenin in cells. Cellular proliferation is antagonistically regulated by canonical and noncanonical Wnt signals; their dysbalance triggers cancers. We previously showed that a multimodular signal transducer, Daple, enhances PI3-K→Akt signals within the noncanonical Wnt signaling pathway and antagonistically inhibits canonical Wnt responses. Here we demonstrate that the PI3-K→Akt pathway serves as a positive feedback loop that further enhances noncanonical Wnt signals by compartmentalizing β-catenin. By phosphorylating the phosphoinositide- (PI) binding domain of Daple, Akt abolishes Daple’s ability to bind PI3-P-enriched endosomes that engage dynein motor complex for long-distance trafficking of β-catenin/E-cadherin complexes to pericentriolar recycling endosomes (PCREs). Phosphorylation compartmentalizes Daple/β-catenin/E-cadherin complexes to cell–cell contact sites, enhances noncanonical Wnt signals, and thereby suppresses colony growth. Dephosphorylation compartmentalizes β-catenin on PCREs, a specialized compartment for prolonged unopposed canonical Wnt signaling, and enhances colony growth. Cancer-associated Daple mutants that are insensitive to Akt mimic a constitutively dephosphorylated state. This work not only identifies Daple as a platform for cross-talk between Akt and the noncanonical Wnt pathway but also reveals the impact of such cross-talk on tumor cell phenotypes that are critical for cancer initiation and progression.
Collapse
Affiliation(s)
- Nicolas Aznar
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Nina Sun
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Ying Dunkel
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Jason Ear
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Matthew D Buschman
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Pradipta Ghosh
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093 .,Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093.,Moores Cancer Centre, University of California, San Diego, La Jolla, CA 92093
| |
Collapse
|
26
|
Paris L, Podo F, Spadaro F, Abalsamo L, Pisanu ME, Ricci A, Cecchetti S, Altabella L, Buoncervello M, Lozneanu L, Bagnoli M, Ramoni C, Canevari S, Mezzanzanica D, Iorio E, Canese R. Phosphatidylcholine-specific phospholipase C inhibition reduces HER2-overexpression, cell proliferation and in vivo tumor growth in a highly tumorigenic ovarian cancer model. Oncotarget 2017; 8:55022-55038. [PMID: 28903399 PMCID: PMC5589638 DOI: 10.18632/oncotarget.18992] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 06/19/2017] [Indexed: 01/02/2023] Open
Abstract
Antagonizing the oncogenic effects of human epidermal growth factor receptor 2 (HER2) with current anti-HER2 agents has not yet yielded major progress in the treatment of advanced HER2-positive epithelial ovarian cancer (EOC). Using preclinical models to explore alternative molecular mechanisms affecting HER2 overexpression and oncogenicity may lead to new strategies for EOC patient treatment. We previously reported that phosphatidylcholine-specific phospholipase C (PC-PLC) exerts a pivotal role in regulating HER2 overexpression in breast cancer cells. The present study, conducted on two human HER2-overexpressing EOC cell lines - SKOV3 and its in vivo-passaged SKOV3.ip cell variant characterized by enhanced in vivo tumorigenicity - and on SKOV3.ip xenografts implanted in SCID mice, showed: a) about 2-fold higher PC-PLC and HER2 protein expression levels in SKOV3.ip compared to SKOV3 cells; b) physical association of PC-PLC with HER2 in non-raft domains; c) HER2 internalization and ca. 50% reduction of HER2 mRNA and protein expression levels in SKOV3.ip cells exposed to the PC-PLC inhibitor tricyclodecan-9-yl-potassium xanthate (D609); d) differential effects of D609 and trastuzumab on HER2 protein expression and cell proliferation; e) decreased in vivo tumor growth in SKOV3.ip xenografts during in vivo treatment with D609; f) potential use of in vivo magnetic resonance spectroscopy (MRS) and imaging (MRI) parameters as biomarkers of EOC response to PC-PLC inhibition. Overall, these findings support the view that PC-PLC inhibition may represent an effective means to target the tumorigenic effects of HER2 overexpression in EOC and that in vivo MR approaches can efficiently monitor its effects.
Collapse
Affiliation(s)
- Luisa Paris
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, 00161, Roma, Italy
| | - Franca Podo
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, 00161, Roma, Italy
| | - Francesca Spadaro
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161, Roma, Italy
| | - Laura Abalsamo
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, 00161, Roma, Italy
| | - Maria Elena Pisanu
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, 00161, Roma, Italy
| | - Alessandro Ricci
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, 00161, Roma, Italy
| | - Serena Cecchetti
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, 00161, Roma, Italy
| | - Luisa Altabella
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, 00161, Roma, Italy
| | - Maria Buoncervello
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161, Roma, Italy
| | - Ludmila Lozneanu
- Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, 20133, Milano, Italy.,Department of Histology, University of Medicine and Pharmacy "Grigore T. Popa", 700115, Iasi, Romania
| | - Marina Bagnoli
- Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, 20133, Milano, Italy
| | - Carlo Ramoni
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, 00161, Roma, Italy
| | - Silvana Canevari
- Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, 20133, Milano, Italy
| | - Delia Mezzanzanica
- Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, 20133, Milano, Italy
| | - Egidio Iorio
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, 00161, Roma, Italy
| | - Rossella Canese
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, 00161, Roma, Italy
| |
Collapse
|
27
|
Abd-El-Haliem AM, Joosten MHAJ. Plant phosphatidylinositol-specific phospholipase C at the center of plant innate immunity. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2017; 59:164-179. [PMID: 28097830 DOI: 10.1111/jipb.12520] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/09/2017] [Indexed: 05/20/2023]
Abstract
Understanding plant resistance to pathogenic microbes requires detailed information on the molecular mechanisms controlling the execution of plant innate immune responses. A growing body of evidence places phosphoinositide-specific phospholipase C (PI-PLC) enzymes immediately downstream of activated immune receptors, well upstream of the initiation of early defense responses. An increase of the cytoplasmic levels of free Ca2+ , lowering of the intercellular pH and the oxidative burst are a few examples of such responses and these are regulated by PI-PLCs. Consequently, PI-PLC activation represents an early primary signaling switch between elicitation and response involving the controlled hydrolysis of essential signaling phospholipids, thereby simultaneously generating lipid and non-lipid second messenger molecules required for a swift cellular defense response. Here, we elaborate on the signals generated by PI-PLCs and their respective downstream effects, while providing an inventory of different types of evidence describing the involvement of PI-PLCs in various aspects of plant immunity. We project the discussed information into a model describing the cellular events occurring after the activation of plant immune receptors. With this review we aim to provide new insights supporting future research on plant PI-PLCs and the development of plants with improved resistance.
Collapse
Affiliation(s)
- Ahmed M Abd-El-Haliem
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Matthieu H A J Joosten
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| |
Collapse
|
28
|
Podo F, Paris L, Cecchetti S, Spadaro F, Abalsamo L, Ramoni C, Ricci A, Pisanu ME, Sardanelli F, Canese R, Iorio E. Activation of Phosphatidylcholine-Specific Phospholipase C in Breast and Ovarian Cancer: Impact on MRS-Detected Choline Metabolic Profile and Perspectives for Targeted Therapy. Front Oncol 2016; 6:171. [PMID: 27532027 PMCID: PMC4969288 DOI: 10.3389/fonc.2016.00171] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 07/05/2016] [Indexed: 12/12/2022] Open
Abstract
Elucidation of molecular mechanisms underlying the aberrant phosphatidylcholine cycle in cancer cells plays in favor of the use of metabolic imaging in oncology and opens the way for designing new targeted therapies. The anomalous choline metabolic profile detected in cancer by magnetic resonance spectroscopy and spectroscopic imaging provides molecular signatures of tumor progression and response to therapy. The increased level of intracellular phosphocholine (PCho) typically detected in cancer cells is mainly attributed to upregulation of choline kinase, responsible for choline phosphorylation in the biosynthetic Kennedy pathway, but can also be partly produced by activation of phosphatidylcholine-specific phospholipase C (PC-PLC). This hydrolytic enzyme, known for implications in bacterial infection and in plant survival to hostile environmental conditions, is reported to be activated in mitogen- and oncogene-induced phosphatidylcholine cycles in mammalian cells, with effects on cell signaling, cell cycle regulation, and cell proliferation. Recent investigations showed that PC-PLC activation could account for 20–50% of the intracellular PCho production in ovarian and breast cancer cells of different subtypes. Enzyme activation was associated with PC-PLC protein overexpression and subcellular redistribution in these cancer cells compared with non-tumoral counterparts. Moreover, PC-PLC coimmunoprecipitated with the human epidermal growth factor receptor-2 (HER2) and EGFR in HER2-overexpressing breast and ovarian cancer cells, while pharmacological PC-PLC inhibition resulted into long-lasting HER2 downregulation, retarded receptor re-expression on plasma membrane and antiproliferative effects. This body of evidence points to PC-PLC as a potential target for newly designed therapies, whose effects can be preclinically and clinically monitored by metabolic imaging methods.
Collapse
Affiliation(s)
- Franca Podo
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Luisa Paris
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Serena Cecchetti
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Francesca Spadaro
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Laura Abalsamo
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Carlo Ramoni
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Alessandro Ricci
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Maria Elena Pisanu
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Francesco Sardanelli
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, Research Hospital Policlinico San Donato , Milan , Italy
| | - Rossella Canese
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| | - Egidio Iorio
- Molecular and Cellular Imaging Unit, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità , Rome , Italy
| |
Collapse
|
29
|
Quercetin regulates hepatic cholesterol metabolism by promoting cholesterol-to-bile acid conversion and cholesterol efflux in rats. Nutr Res 2016; 36:271-9. [DOI: 10.1016/j.nutres.2015.11.019] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 11/02/2015] [Accepted: 11/04/2015] [Indexed: 01/11/2023]
|
30
|
Cífková E, Hájek R, Lísa M, HolĿapek M. Hydrophilic interaction liquid chromatography-mass spectrometry of (lyso)phosphatidic acids, (lyso)phosphatidylserines and other lipid classes. J Chromatogr A 2016; 1439:65-73. [PMID: 26858118 DOI: 10.1016/j.chroma.2016.01.064] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 01/15/2016] [Accepted: 01/25/2016] [Indexed: 01/08/2023]
Abstract
The goal of this work is a systematic optimization of hydrophilic interaction liquid chromatography (HILIC) separation of acidic lipid classes (namely phosphatidic acids-PA, lysophosphatidic acids-LPA, phosphatidylserines-PS and lysophosphatidylserines-LPS) and other lipid classes under mass spectrometry (MS) compatible conditions. The main parameters included in this optimization are the type of stationary phases used in HILIC, pH of the mobile phase, the type and concentration of mobile phase additives. Nine HILIC columns with different chemistries (unmodified silica, modified silica using diol, 2-picolylamine, diethylamine and 1-aminoanthracene and hydride silica) are compared with the emphasis on peak shapes of acidic lipid classes. The optimization of pH is correlated with the theoretical calculation of acidobasic equilibria of studied lipid classes. The final method using the hydride column, pH 4 adjusted by formic acid and the gradient of acetonitrile and 40 mmol/L of aqueous ammonium formate provides good peak shapes for all analyzed lipid classes including acidic lipids. This method is applied for the identification of lipids in real samples of porcine brain and kidney extracts.
Collapse
Affiliation(s)
- Eva Cífková
- Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice, Czech Republic
| | - Roman Hájek
- Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice, Czech Republic
| | - Miroslav Lísa
- Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice, Czech Republic
| | - Michal HolĿapek
- Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice, Czech Republic.
| |
Collapse
|
31
|
Himeno H, Ito H, Higuchi Y, Hamada T, Shimokawa N, Takagi M. Coupling between pore formation and phase separation in charged lipid membranes. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:062713. [PMID: 26764733 DOI: 10.1103/physreve.92.062713] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Indexed: 06/05/2023]
Abstract
We investigated the effect of charge on the membrane morphology of giant unilamellar vesicles (GUVs) composed of various mixtures containing charged lipids. We observed the membrane morphologies by fluorescent and confocal laser microscopy in lipid mixtures consisting of a neutral unsaturated lipid [dioleoylphosphatidylcholine (DOPC)], a neutral saturated lipid [dipalmitoylphosphatidylcholine (DPPC)], a charged unsaturated lipid [dioleoylphosphatidylglycerol (DOPG((-)))], a charged saturated lipid [dipalmitoylphosphatidylglycerol (DPPG((-)))], and cholesterol (Chol). In binary mixtures of neutral DOPC-DPPC and charged DOPC-DPPG((-))), spherical vesicles were formed. On the other hand, pore formation was often observed with GUVs consisting of DOPG((-))) and DPPC. In a DPPC-DPPG((-)))-Chol ternary mixture, pore-formed vesicles were also frequently observed. The percentage of pore-formed vesicles increased with the DPPG((-))) concentration. Moreover, when the head group charges of charged lipids were screened by the addition of salt, pore-formed vesicles were suppressed in both the binary and ternary charged lipid mixtures. We discuss the mechanisms of pore formation in charged lipid mixtures and the relationship between phase separation and the membrane morphology. Finally, we reproduce the results seen in experimental systems by using coarse-grained molecular dynamics simulations.
Collapse
Affiliation(s)
- Hiroki Himeno
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu 761-0395, Japan
| | - Hiroaki Ito
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Yuji Higuchi
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - Tsutomu Hamada
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
| | - Naofumi Shimokawa
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
| | - Masahiro Takagi
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
| |
Collapse
|
32
|
Marchini-Alves CMM, Barbosa Lorenzi VC, da Silva EZM, Mazucato VM, Jamur MC, Oliver C. Phospholipase D2 Modulates the Secretory Pathway in RBL-2H3 Mast Cells. PLoS One 2015; 10:e0139888. [PMID: 26492088 PMCID: PMC4619593 DOI: 10.1371/journal.pone.0139888] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 09/18/2015] [Indexed: 11/19/2022] Open
Abstract
Phospholipase D (PLD) hydrolyses phosphatidylcholine to produce phosphatidic acid (PA) and choline. It has two isoforms, PLD1 and PLD2, which are differentially expressed depending on the cell type. In mast cells it plays an important role in signal transduction. The aim of the present study was to clarify the role of PLD2 in the secretory pathway. RBL-2H3 cells, a mast cell line, transfected to overexpress catalytically active (PLD2CA) and inactive (PLD2CI) forms of PLD2 were used. Previous observations showed that the Golgi complex was well organized in CA cells, but was disorganized and dispersed in CI cells. Furthermore, in CI cells, the microtubule organizing center was difficult to identify and the microtubules were disorganized. These previous observations demonstrated that PLD2 is important for maintaining the morphology and organization of the Golgi complex. To further understand the role of PLD2 in secretory and vesicular trafficking, the role of PLD2 in the secretory process was investigated. Incorporation of sialic acid was used to follow the synthesis and transport of glycoconjugates in the cell lines. The modified sialic acid was subsequently detected by labeling with a fluorophore or biotin to visualize the localization of the molecule after a pulse-chase for various times. Glycoconjugate trafficking was slower in the CI cells and labeled glycans took longer to reach the plasma membrane. Furthermore, in CI cells sialic acid glycans remained at the plasma membrane for longer periods of time compared to RBL-2H3 cells. These results suggest that PLD2 activity plays an important role in regulating glycoconjugate trafficking in mast cells.
Collapse
Affiliation(s)
- Claudia Maria Meirelles Marchini-Alves
- Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Valeria Cintra Barbosa Lorenzi
- Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Elaine Zayas Marcelino da Silva
- Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Vivian Marino Mazucato
- Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Maria Celia Jamur
- Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Constance Oliver
- Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
- * E-mail:
| |
Collapse
|
33
|
Kondakova T, D'Heygère F, Feuilloley MJ, Orange N, Heipieper HJ, Duclairoir Poc C. Glycerophospholipid synthesis and functions in Pseudomonas. Chem Phys Lipids 2015; 190:27-42. [PMID: 26148574 DOI: 10.1016/j.chemphyslip.2015.06.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 06/29/2015] [Accepted: 06/30/2015] [Indexed: 11/25/2022]
Abstract
The genus Pseudomonas is one of the most heterogeneous groups of eubacteria, presents in all major natural environments and in wide range of associations with plants and animals. The wide distribution of these bacteria is due to the use of specific mechanisms to adapt to environmental modifications. Generally, bacterial adaptation is only considered under the aspect of genes and protein expression, but lipids also play a pivotal role in bacterial functioning and homeostasis. This review resumes the mechanisms and regulations of pseudomonal glycerophospholipid synthesis, and the roles of glycerophospholipids in bacterial metabolism and homeostasis. Recently discovered specific pathways of P. aeruginosa lipid synthesis indicate the lineage dependent mechanisms of fatty acids homeostasis. Pseudomonas glycerophospholipids ensure structure functions and play important roles in bacterial adaptation to environmental modifications. The lipidome of Pseudomonas contains a typical eukaryotic glycerophospholipid--phosphatidylcholine -, which is involved in bacteria-host interactions. The ability of Pseudomonas to exploit eukaryotic lipids shows specific and original strategies developed by these microorganisms to succeed in their infectious process. All compiled data provide the demonstration of the importance of studying the Pseudomonas lipidome to inhibit the infectious potential of these highly versatile germs.
Collapse
Affiliation(s)
- Tatiana Kondakova
- Normandie University of Rouen, Laboratory of Microbiology Signals and Microenvironment (LMSM), EA 4312, 55 rue St. Germain, 27000 Evreux, France
| | - François D'Heygère
- Centre de Biophysique Moléculaire, CNRS, UPR4301, rue Charles Sadron, 45071 Orléans, France
| | - Marc J Feuilloley
- Normandie University of Rouen, Laboratory of Microbiology Signals and Microenvironment (LMSM), EA 4312, 55 rue St. Germain, 27000 Evreux, France
| | - Nicole Orange
- Normandie University of Rouen, Laboratory of Microbiology Signals and Microenvironment (LMSM), EA 4312, 55 rue St. Germain, 27000 Evreux, France
| | - Hermann J Heipieper
- Department of Environmental Biotechnology, UFZ Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
| | - Cécile Duclairoir Poc
- Normandie University of Rouen, Laboratory of Microbiology Signals and Microenvironment (LMSM), EA 4312, 55 rue St. Germain, 27000 Evreux, France.
| |
Collapse
|
34
|
Stith BJ. Phospholipase C and D regulation of Src, calcium release and membrane fusion during Xenopus laevis development. Dev Biol 2015; 401:188-205. [PMID: 25748412 DOI: 10.1016/j.ydbio.2015.02.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 02/15/2015] [Accepted: 02/24/2015] [Indexed: 11/28/2022]
Abstract
This review emphasizes how lipids regulate membrane fusion and the proteins involved in three developmental stages: oocyte maturation to the fertilizable egg, fertilization and during first cleavage. Decades of work show that phosphatidic acid (PA) releases intracellular calcium, and recent work shows that the lipid can activate Src tyrosine kinase or phospholipase C during Xenopus fertilization. Numerous reports are summarized to show three levels of increase in lipid second messengers inositol 1,4,5-trisphosphate and sn 1,2-diacylglycerol (DAG) during the three different developmental stages. In addition, possible roles for PA, ceramide, lysophosphatidylcholine, plasmalogens, phosphatidylinositol 4-phosphate, phosphatidylinositol 5-phosphate, phosphatidylinositol 4,5-bisphosphate, membrane microdomains (rafts) and phosphatidylinositol 3,4,5-trisphosphate in regulation of membrane fusion (acrosome reaction, sperm-egg fusion, cortical granule exocytosis), inositol 1,4,5-trisphosphate receptors, and calcium release are discussed. The role of six lipases involved in generating putative lipid second messengers during fertilization is also discussed: phospholipase D, autotaxin, lipin1, sphingomyelinase, phospholipase C, and phospholipase A2. More specifically, proteins involved in developmental events and their regulation through lipid binding to SH3, SH4, PH, PX, or C2 protein domains is emphasized. New models are presented for PA activation of Src (through SH3, SH4 and a unique domain), that this may be why the SH2 domain of PLCγ is not required for Xenopus fertilization, PA activation of phospholipase C, a role for PA during the calcium wave after fertilization, and that calcium/calmodulin may be responsible for the loss of Src from rafts after fertilization. Also discussed is that the large DAG increase during fertilization derives from phospholipase D production of PA and lipin dephosphorylation to DAG.
Collapse
Affiliation(s)
- Bradley J Stith
- University of Colorado Denver, Department of Integrative Biology, Campus Box 171, PO Box 173364, Denver, CO 80217-3364, United States.
| |
Collapse
|
35
|
Pejchar P, Potocký M, Krčková Z, Brouzdová J, Daněk M, Martinec J. Non-specific phospholipase C4 mediates response to aluminum toxicity in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2015; 6:66. [PMID: 25763003 PMCID: PMC4329606 DOI: 10.3389/fpls.2015.00066] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 01/26/2015] [Indexed: 05/06/2023]
Abstract
Aluminum ions (Al) have been recognized as a major toxic factor for crop production in acidic soils. The first indication of the Al toxicity in plants is the cessation of root growth, but the mechanism of root growth inhibition is largely unknown. Here we examined the impact of Al on the expression, activity, and function of the non-specific phospholipase C4 (NPC4), a plasma membrane-bound isoform of NPC, a member of the plant phospholipase family, in Arabidopsis thaliana. We observed a lower expression of NPC4 using β-glucuronidase assay and a decreased formation of labeled diacylglycerol, product of NPC activity, using fluorescently labeled phosphatidylcholine as a phospholipase substrate in Arabidopsis WT seedlings treated with AlCl3 for 2 h. The effect on in situ NPC activity persisted for longer Al treatment periods (8, 14 h). Interestingly, in seedlings overexpressing NPC4, the Al-mediated NPC-inhibiting effect was alleviated at 14 h. However, in vitro activity and localization of NPC4 were not affected by Al, thus excluding direct inhibition by Al ions or possible translocation of NPC4 as the mechanisms involved in NPC-inhibiting effect. Furthermore, the growth of tobacco pollen tubes rapidly arrested by Al was partially rescued by the overexpression of AtNPC4 while Arabidopsis npc4 knockout lines were found to be more sensitive to Al stress during long-term exposure of Al at low phosphate conditions. Our observations suggest that NPC4 plays a role in both early and long-term responses to Al stress.
Collapse
Affiliation(s)
- Přemysl Pejchar
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, PragueCzech Republic
| | | | | | | | | | | |
Collapse
|
36
|
Pejchar P, Martinec J. Aluminum ions alter the function of non-specific phospholipase C through the changes in plasma membrane physical properties. PLANT SIGNALING & BEHAVIOR 2015; 10:e1031938. [PMID: 26024014 PMCID: PMC4622580 DOI: 10.1080/15592324.2015.1031938] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 03/12/2015] [Accepted: 03/12/2015] [Indexed: 05/20/2023]
Abstract
The first indication of the aluminum (Al) toxicity in plants growing in acidic soils is the cessation of root growth, but the detailed mechanism of Al effect is unknown. Here we examined the impact of Al stress on the activity of non-specific phospholipase C (NPC) in the connection with the processes related to the plasma membrane using fluorescently labeled phosphatidylcholine. We observed a rapid and significant decrease of labeled diacylglycerol (DAG), product of NPC activity, in Arabidopsis seedlings treated with AlCl₃. Interestingly, an application of the membrane fluidizer, benzyl alcohol, restored the level of DAG during Al treatment. Our observations suggest that the activity of NPC is affected by Al-induced changes in plasma membrane physical properties.
Collapse
Key Words
- Arabidopsis thaliana
- BA, benzyl alcohol
- BODIPY
- BODIPY, 4, 4-difluoro-4-bora-3a, 4a-diaza-s-indacene
- BY-2, Bright Yellow 2
- DAG, diacylglycerol
- HP-TLC, high-performance thin-layer chromatography
- MS, Murashige-Skoog
- NPC, non-specific phospholipase C
- PA, phosphatidic acid
- PC, phosphatidylcholine
- PC-PLC, phosphatidylcholine-specific phospholipase C
- PI-PLC, phosphatidylinositol-specific phospholipase C
- PIP2, phosphatidylinositol 4, 5-bisphosphate
- PLD, phospholipase D
- PM, plasma membrane.
- aluminum toxicity
- benzyl alcohol
- diacylglycerol
- membrane fluidity
- non-specific phospholipase C
Collapse
Affiliation(s)
- Přemysl Pejchar
- Institute of Experimental Botany, v. v. i.; Academy of Sciences of the Czech Republic; Prague, Czech Republic
| | - Jan Martinec
- Institute of Experimental Botany, v. v. i.; Academy of Sciences of the Czech Republic; Prague, Czech Republic
| |
Collapse
|
37
|
Kokotos AC, Cousin MA. Synaptic vesicle generation from central nerve terminal endosomes. Traffic 2014; 16:229-40. [PMID: 25346420 DOI: 10.1111/tra.12235] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 10/15/2014] [Accepted: 10/20/2014] [Indexed: 01/01/2023]
Abstract
Central nerve terminals contain a small number of synaptic vesicles (SVs) that must sustain the fidelity of neurotransmission across a wide range of stimulation intensities. For this to be achieved, nerve terminals integrate a number of complementary endocytosis modes whose activation spans the breadth of these neuronal stimulation patterns. Two such modes are ultrafast endocytosis and activity-dependent bulk endocytosis, which are triggered by stimuli at either end of the physiological range. Both endocytosis modes generate endosomes directly from the nerve terminal plasma membrane, before the subsequent production of SVs from these structures. This review will discuss the current knowledge relating to the molecular mechanisms involved in the generation of SVs from nerve terminal endosomes, how this relates to other mechanisms of SV production and the functional role of such SVs.
Collapse
Affiliation(s)
- Alexandros C Kokotos
- Centre for Integrative Physiology, George Square, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | | |
Collapse
|
38
|
Martínez-Martínez N, Martínez-Alonso E, Ballesta J, Martínez-Menárguez JA. Phospholipase D2 is involved in the formation of Golgi tubules and ArfGAP1 recruitment. PLoS One 2014; 9:e111685. [PMID: 25354038 PMCID: PMC4213061 DOI: 10.1371/journal.pone.0111685] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 10/03/2014] [Indexed: 11/19/2022] Open
Abstract
Lipids and lipid-modifying enzymes play a key role in the biogenesis, maintenance and fission of transport carriers in the secretory and endocytic pathways. In the present study we demonstrate that phosphatidic acid generated by phospholipase D2 (PLD2) is involved in the formation of Golgi tubules. The main evidence to support this is: 1) inhibitors of phosphatidic acid formation and PLD2 depletion inhibit the formation of tubules containing resident enzymes and regulators of intra-Golgi transport in a low temperature (15°C) model of Golgi tubulation but do not affect brefeldin A-induced tubules, 2) inhibition of PLD2 enzymatic activity and PLD2 depletion in cells cultured under physiological conditions (37°C) induce the formation of tubules specifically containing Golgi matrix proteins, and, 3) over-expression of PLD2 induces the formation of a tubular network. In addition, it was found that the generation of this lipid by the isoenzyme is necessary for ArfGAP1 recruitment to Golgi membranes. These results suggest that both proteins are involved in the molecular mechanisms which drive the formation of different types of Golgi tubules.
Collapse
Affiliation(s)
- Narcisa Martínez-Martínez
- Department of Cell Biology and Histology, Medical School, IMIB-Arrixaca, University of Murcia, Murcia, Spain
| | - Emma Martínez-Alonso
- Department of Cell Biology and Histology, Medical School, IMIB-Arrixaca, University of Murcia, Murcia, Spain
| | - José Ballesta
- Department of Cell Biology and Histology, Medical School, IMIB-Arrixaca, University of Murcia, Murcia, Spain
| | - José A. Martínez-Menárguez
- Department of Cell Biology and Histology, Medical School, IMIB-Arrixaca, University of Murcia, Murcia, Spain
- * E-mail:
| |
Collapse
|
39
|
Baba T, Kashiwagi Y, Arimitsu N, Kogure T, Edo A, Maruyama T, Nakao K, Nakanishi H, Kinoshita M, Frohman MA, Yamamoto A, Tani K. Phosphatidic acid (PA)-preferring phospholipase A1 regulates mitochondrial dynamics. J Biol Chem 2014; 289:11497-11511. [PMID: 24599962 PMCID: PMC4036285 DOI: 10.1074/jbc.m113.531921] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 03/04/2014] [Indexed: 12/14/2022] Open
Abstract
Recent studies have suggested that phosphatidic acid (PA), a cone-shaped phospholipid that can generate negative curvature of lipid membranes, participates in mitochondrial fusion. However, precise mechanisms underling the production and consumption of PA on the mitochondrial surface are not fully understood. Phosphatidic acid-preferring phospholipase A1 (PA-PLA1)/DDHD1 is the first identified intracellular phospholipase A1 and preferentially hydrolyzes PA in vitro. Its cellular and physiological functions have not been elucidated. In this study, we show that PA-PLA1 regulates mitochondrial dynamics. PA-PLA1, when ectopically expressed in HeLa cells, induced mitochondrial fragmentation, whereas its depletion caused mitochondrial elongation. The effects of PA-PLA1 on mitochondrial morphology appear to counteract those of MitoPLD, a mitochondrion-localized phospholipase D that produces PA from cardiolipin. Consistent with high levels of expression of PA-PLA1 in testis, PA-PLA1 knock-out mice have a defect in sperm formation. In PA-PLA1-deficient sperm, the mitochondrial structure is disorganized, and an abnormal gap structure exists between the middle and principal pieces. A flagellum is bent at that position, leading to a loss of motility. Our results suggest a possible mechanism of PA regulation of the mitochondrial membrane and demonstrate an in vivo function of PA-PLA1 in the organization of mitochondria during spermiogenesis.
Collapse
Affiliation(s)
- Takashi Baba
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Yuriko Kashiwagi
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Nagisa Arimitsu
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Takeshi Kogure
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Ayumi Edo
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Tomohiro Maruyama
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Kazuki Nakao
- RIKEN Center for Developmental Biology, 2-2-3 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Hiroki Nakanishi
- Research Center for Biosignal, Akita University, Akita 010-8543, Japan
| | - Makoto Kinoshita
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Michael A Frohman
- Department of Pharmacology and Center for Developmental Genetics, Stony Brook University, Stony Brook, New York 11794-5140, and
| | - Akitsugu Yamamoto
- Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Nagahama, Shiga 526-0829, Japan
| | - Katsuko Tani
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan,.
| |
Collapse
|
40
|
Sahini N, Borlak J. Recent insights into the molecular pathophysiology of lipid droplet formation in hepatocytes. Prog Lipid Res 2014; 54:86-112. [PMID: 24607340 DOI: 10.1016/j.plipres.2014.02.002] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 02/17/2014] [Accepted: 02/21/2014] [Indexed: 12/11/2022]
Abstract
Triacyglycerols are a major energy reserve of the body and are normally stored in adipose tissue as lipid droplets (LDs). The liver, however, stores energy as glycogen and digested triglycerides in the form of fatty acids. In stressed condition such as obesity, imbalanced nutrition and drug induced liver injury hepatocytes accumulate excess lipids in the form of LDs whose prolonged storage leads to disease conditions most notably non-alcoholic fatty liver disease (NAFLD). Fatty liver disease has become a major health burden with more than 90% of obese, nearly 70% of overweight and about 25% of normal weight patients being affected. Notably, research in recent years has shown LD as highly dynamic organelles for maintaining lipid homeostasis through fat storage, protein sorting and other molecular events studied in adipocytes and other cells of living organisms. This review focuses on the molecular events of LD formation in hepatocytes and the importance of cross talk between different cell types and their signalling in NAFLD as to provide a perspective on molecular mechanisms as well as possibilities for different therapeutic intervention strategies.
Collapse
Affiliation(s)
- Nishika Sahini
- Centre for Pharmacology and Toxicology, Hannover Medical School, 30625 Hannover, Germany
| | - Jürgen Borlak
- Centre for Pharmacology and Toxicology, Hannover Medical School, 30625 Hannover, Germany.
| |
Collapse
|
41
|
Liu C, Huang D, Yang T, Cremer PS. Monitoring phosphatidic acid formation in intact phosphatidylcholine bilayers upon phospholipase D catalysis. Anal Chem 2014; 86:1753-9. [PMID: 24456402 PMCID: PMC3983022 DOI: 10.1021/ac403580r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 01/15/2014] [Indexed: 12/25/2022]
Abstract
We have monitored the production of the negatively charged lipid, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidic acid acid (POPA), in supported lipid bilayers via the enzymatic hydrolysis of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (PC), a zwitterionic lipid. Experiments were performed with phospholipase D (PLD) in a Ca(2+) dependent fashion. The strategy for doing this involved using membrane-bound streptavidin as a biomarker for the charge on the membrane. The focusing position of streptavidin in electrophoretic-electroosmotic focusing (EEF) experiments was monitored via a fluorescent tag on this protein. The negative charge increased during these experiments due to the formation of POPA lipids. This caused the focusing position of streptavidin to migrate toward the negatively charged electrode. With the use of a calibration curve, the amount of POPA generated during this assay could be read out from the intact membrane, an objective that has been otherwise difficult to achieve because of the lack of unique chromophores on PA lipids. On the basis of these results, other enzymatic reactions involving the change in membrane charge could also be monitored in a similar way. This would include phosphorylation, dephosphorylation, lipid biosynthesis, and additional phospholipase reactions.
Collapse
Affiliation(s)
- Chunming Liu
- Department
of Chemistry, Texas A&M University, 3255 TAMU, College Station, TX 77843, United States
| | - Da Huang
- Department
of Chemistry, Texas A&M University, 3255 TAMU, College Station, TX 77843, United States
| | - Tinglu Yang
- Department
of Chemistry, Texas A&M University, 3255 TAMU, College Station, TX 77843, United States
| | - Paul S. Cremer
- Department
of Chemistry, Texas A&M University, 3255 TAMU, College Station, TX 77843, United States
| |
Collapse
|
42
|
van der Sluijs P, Zibouche M, van Kerkhof P. Late steps in secretory lysosome exocytosis in cytotoxic lymphocytes. Front Immunol 2013; 4:359. [PMID: 24302923 PMCID: PMC3831147 DOI: 10.3389/fimmu.2013.00359] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 10/22/2013] [Indexed: 12/16/2022] Open
Abstract
Natural Killer cells are a subset of cytotoxic lymphocytes that are important in host defense against infections and transformed cells. They exert this function through recognition of target cells by cell surface receptors, which triggers a signaling program that results in a re-orientation of the microtubule organizing center and secretory lysosomes toward the target cell. Upon movement of secretory lysosomes to the plasma membrane and subsequent fusion, toxic proteins are released by secretory lysosomes in the immunological synapse which then enter and kill the target cell. In this minireview we highlight recent progress in our knowledge of late steps in this specialized secretion pathway and address important open questions.
Collapse
Affiliation(s)
- Peter van der Sluijs
- Department of Cell Biology, University Medical Center Utrecht , Utrecht , Netherlands
| | | | | |
Collapse
|
43
|
Zhang H, Kim A, Abraham N, Khan LA, Göbel V. Vesicular sorting controls the polarity of expanding membranes in the C. elegans intestine. WORM 2013; 2:e23702. [PMID: 24058862 PMCID: PMC3670463 DOI: 10.4161/worm.23702] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 01/16/2013] [Indexed: 11/19/2022]
Abstract
Biological tubes consist of polarized epithelial cells with apical membranes building the central lumen and basolateral membranes contacting adjacent cells or the extracellular matrix. Cellular polarity requires distinct inputs from outside the cell, e.g., the matrix, inside the cell, e.g., vesicular trafficking and the plasma membrane and its junctions.1 Many highly conserved polarity cues have been identified, but their integration during the complex process of polarized tissue and organ morphogenesis is not well understood. It is assumed that plasma-membrane-associated polarity determinants, such as the partitioning-defective (PAR) complex, define plasma membrane domain identities, whereas vesicular trafficking delivers membrane components to these domains, but lacks the ability to define them. In vitro studies on lumenal membrane biogenesis in mammalian cell lines now indicate that trafficking could contribute to defining membrane domains by targeting the polarity determinants, e.g., the PARs, themselves.2 This possibility suggests a mechanism for PARs’ asymmetric distribution on membranes and places vesicle-associated polarity cues upstream of membrane-associated polarity determinants. In such an upstream position, trafficking might even direct multiple membrane components, not only polarity determinants, an original concept of polarized plasma membrane biogenesis3,4that was largely abandoned due to the failure to identify a molecularly defined intrinsic vesicular sorting mechanism. Our two recent studies on C. elegans intestinal tubulogenesis reveal that glycosphingolipids (GSLs) and the well-recognized vesicle components clathrin and its AP-1 adaptor are required for targeting multiple apical molecules, including polarity regulators, to the expanding apical/lumenal membrane.5,6 These findings support GSLs’ long-proposed role in in vivo polarized epithelial membrane biogenesis and development and identify a novel function in apical polarity for classical post-Golgi vesicle components. They are also compatible with a vesicle-intrinsic sorting mechanism during membrane biogenesis and suggest a model for how vesicles could acquire apical directionality during the assembly of the functionally critical polarized lumenal surfaces of epithelial tubes.
Collapse
Affiliation(s)
- Hongjie Zhang
- Department of Pediatrics; Massachusetts General Hospital; Harvard Medical School; Boston, MA USA
| | | | | | | | | |
Collapse
|
44
|
Dall'Armi C, Devereaux KA, Di Paolo G. The role of lipids in the control of autophagy. Curr Biol 2013; 23:R33-45. [PMID: 23305670 DOI: 10.1016/j.cub.2012.10.041] [Citation(s) in RCA: 211] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Macroautophagy is an essential cellular pathway mediating the lysosomal degradation of defective organelles, long-lived proteins and a variety of protein aggregates. Similar to other intracellular trafficking pathways, macroautophagy involves a complex sequence of membrane remodeling and trafficking events. These include the biogenesis of autophagosomes, which engulf portions of cytoplasm at specific subcellular locations, and their subsequent maturation into autophagolysosomes through fusion with the endo-lysosomal compartment. Although the formation and maturation of autophagosomes are controlled by molecular reactions occurring at the membrane-cytosol interface, little is known about the role of lipids and their metabolizing enzymes in this process. Historically dominated by studies on class III phosphatidylinositol 3-kinase (also known as Vps34) and its product phosphatidylinositol-3-phosphate, as well as on the lipidation of Atg8/LC3-like proteins, this area of research has recently expanded, implicating a variety of other lipids, such as phosphatidic acid and diacylglycerol, and their metabolizing enzymes in macroautophagy. This review summarizes this progress and highlights the role of specific lipids in the various steps of macroautophagy, including the signaling processes underlying macroautophagy initiation, autophagosome biogenesis and maturation.
Collapse
Affiliation(s)
- Claudia Dall'Armi
- Department of Pathology and Cell Biology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY 10032, USA
| | | | | |
Collapse
|
45
|
Synaptic vesicle generation from activity-dependent bulk endosomes requires calcium and calcineurin. J Neurosci 2013; 33:3370-9. [PMID: 23426665 DOI: 10.1523/jneurosci.4697-12.2013] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Activity-dependent bulk endocytosis (ADBE) is the dominant mode of synaptic vesicle (SV) endocytosis during high-frequency stimulation in central nerve terminals. ADBE generates endosomes direct from the plasma membrane, meaning that high concentrations of calcium will be present in their interior due to fluid phase uptake from the extracellular space. Morphological and fluorescent assays were used to track the generation of SVs from bulk endosomes in primary neuronal culture. This process was functionally uncoupled from both SV exocytosis and plasma membrane retrieval events by intervening only after SV fusion and endocytosis were completed. Either intracellular (BAPTA-AM) or intra-endosomal (Rhod-dextran) calcium chelation inhibited SV generation from bulk endosomes, indicating that calcium efflux from this compartment is critical for this process. The V-type ATPase antagonist bafilomycin A1 also arrested SV generation from bulk endosomes, indicating endosomal acidification may be required for calcium efflux. Finally, pharmacological inhibition of the calcium-dependent protein phosphatase calcineurin blocked endosomal SV generation, identifying it as a key downstream effector in this process. These results reveal a novel and key role for the fluid phase uptake of extracellular calcium and its subsequent efflux in the SV lifecycle.
Collapse
|
46
|
Mitochondria-type GPAT is required for mitochondrial fusion. EMBO J 2013; 32:1265-79. [PMID: 23572076 PMCID: PMC3642685 DOI: 10.1038/emboj.2013.77] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 03/12/2013] [Indexed: 01/09/2023] Open
Abstract
Glycerol-3-phosphate acyltransferase (GPAT) is involved in the first step in glycerolipid synthesis and is localized in both the endoplasmic reticulum (ER) and mitochondria. To clarify the functional differences between ER-GPAT and mitochondrial (Mt)-GPAT, we generated both GPAT mutants in C. elegans and demonstrated that Mt-GPAT is essential for mitochondrial fusion. Mutation of Mt-GPAT caused excessive mitochondrial fragmentation. The defect was rescued by injection of lysophosphatidic acid (LPA), a direct product of GPAT, and by inhibition of LPA acyltransferase, both of which lead to accumulation of LPA in the cells. Mitochondrial fragmentation in Mt-GPAT mutants was also rescued by inhibition of mitochondrial fission protein DRP-1 and by overexpression of mitochondrial fusion protein FZO-1/mitofusin, suggesting that the fusion/fission balance is affected by Mt-GPAT depletion. Mitochondrial fragmentation was also observed in Mt-GPAT-depleted HeLa cells. A mitochondrial fusion assay using HeLa cells revealed that Mt-GPAT depletion impaired mitochondrial fusion process. We postulate from these results that LPA produced by Mt-GPAT functions not only as a precursor for glycerolipid synthesis but also as an essential factor of mitochondrial fusion.
Collapse
|
47
|
Raab A, Newcombe C, Pitton D, Ebel R, Feldmann J. Comprehensive analysis of lipophilic arsenic species in a brown alga (Saccharina latissima). Anal Chem 2013; 85:2817-24. [PMID: 23394220 DOI: 10.1021/ac303340t] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Approaches for the unambiguous identification of lipophilic arsenic species in Saccharina latissima (sugar kelp) have been studied. Parallel use of high resolution ICPMS and electrospray ionization (ESI)-MS after separation revealed that Saccharina latissima contained three distinct classes of lipophilic As-species, a family of arsenic containing phospholipids (AsPL), all including As in the form of As-sugar-PO4, As-containing hydrocarbons (AsHC), and As-containing polyunsaturated fatty acids (AsFA). For detailed identification, the use of phospholipases, in particular phospholipase A2, was essential to define the fatty acid composition (determination of regioisomers) of the lipids without purification of the sample, while fragmentation of the molecules by MS(2) measurements alone did not supply this information. Some of the identified AsPL contained unsaturated fatty acids (C16:1, C18:1 to C18:3), but saturated fatty acids dominated the AsPL. The fatty acid bound to the position 2″ was predominantly C16:0. Complete lipid hydrolysis showed that this alga did not contain arsenic containing fatty acids (AsFA) bound to complex lipids. Our investigations indicate that in addition to RP-HPLC-ICPMS/ESI-MS a range of different derivatization methods should be used for the comprehensive identification of unknown lipid-soluble arsenic compounds.
Collapse
Affiliation(s)
- Andrea Raab
- TESLA (Trace Element Speciation Laboratory), Department of Chemistry, Meston Walk, University of Aberdeen, Aberdeen AB24 3UE, Scotland, United Kingdom
| | | | | | | | | |
Collapse
|
48
|
Pokotylo I, Pejchar P, Potocký M, Kocourková D, Krčková Z, Ruelland E, Kravets V, Martinec J. The plant non-specific phospholipase C gene family. Novel competitors in lipid signalling. Prog Lipid Res 2012; 52:62-79. [PMID: 23089468 DOI: 10.1016/j.plipres.2012.09.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 09/25/2012] [Accepted: 09/25/2012] [Indexed: 11/16/2022]
Abstract
Non-specific phospholipases C (NPCs) were discovered as a novel type of plant phospholipid-cleaving enzyme homologous to bacterial phosphatidylcholine-specific phospholipases C and responsible for lipid conversion during phosphate-limiting conditions. The six-gene family was established in Arabidopsis, and growing evidence suggests the involvement of two articles NPCs in biotic and abiotic stress responses as well as phytohormone actions. In addition, the diacylglycerol produced via NPCs is postulated to participate in membrane remodelling, general lipid metabolism and cross-talk with other phospholipid signalling systems in plants. This review summarises information concerning this new plant protein family and focusses on its sequence analysis, biochemical properties, cellular and tissue distribution and physiological functions. Possible modes of action are also discussed.
Collapse
Affiliation(s)
- Igor Pokotylo
- Institute of Bioorganic Chemistry and Petrochemistry, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Roach AN, Wang Z, Wu P, Zhang F, Chan RB, Yonekubo Y, Di Paolo G, Gorfe AA, Du G. Phosphatidic acid regulation of PIPKI is critical for actin cytoskeletal reorganization. J Lipid Res 2012; 53:2598-609. [PMID: 22991193 DOI: 10.1194/jlr.m028597] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Type I phosphatidylinositol-4-phosphate 5-kinase (PIPKI) is the main enzyme generating the lipid second messenger phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2], which has critical functions in many cellular processes, such as cytoskeletal reorganization, membrane trafficking, and signal transduction. All three members of the PIPKI family are activated by phosphatidic acid (PA). However, how PA regulates the activity and functions of PIPKI have not been fully elucidated. In this study, we identify a PA-binding site on PIPKIγ. Mutation of this site inhibited the PA-stimulated activity and membrane localization of PIPKIγ as well as the formation of actin comets and foci induced by PIPKIγ. We also demonstrate that phospholipase D (PLD) generates a pool of PA involved in PIPKIγ regulation by showing that PLD inhibitors blocked the membrane localization of PIPKIγ and its ability to induce actin cytoskeletal reorganization. Targeting the PIPKIγ PA-binding-deficient mutant to membranes by a membrane localization sequence failed to restore the actin reorganization activity of PIPKIγ, suggesting that PA binding is not only involved in recruiting PIPKIγ to membranes but also may induce a conformational change. Taken together, these results reveal a new molecular mechanism through which PA regulates PIPKI and provides direct evidence that PA is important for the localization and functions of PIPKI in intact cells.
Collapse
Affiliation(s)
- Akua N Roach
- Department of Pharmacology and Center for Developmental Genetics, Stony Brook University, Stony Brook, NY 11794, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Kawaguchi M, Valencia JC, Namiki T, Suzuki T, Hearing VJ. Diacylglycerol kinase regulates tyrosinase expression and function in human melanocytes. J Invest Dermatol 2012; 132:2791-9. [PMID: 22895365 PMCID: PMC3502659 DOI: 10.1038/jid.2012.261] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Diacylglycerol increases the melanin content of human melanocytes in vitro and increases the pigmentation of guinea pig skin in vivo, but the mechanism(s) underlying those effects remain unknown. In this study, we characterized the role of diacylglycerol kinase (DGK), which phosphorylates diacylglycerol to generate phosphatidic acid, in the regulation of pigmentation. Ten isoforms of DGK have been identified, and we show that DGKζ is the most abundant isoform expressed by human melanocytic cells. Melanin content, tyrosinase activity and tyrosinase protein levels were significantly reduced by a DGK inhibitor, but tyrosinase and MITF mRNA levels were not changed by that inhibition, and there were no effects on the expression of other melanogenesis-related proteins. Isoform-specific siRNAs showed that knockdown of DGKζ decreased melanin content and tyrosinase expression in melanocytic cells. Over-expression of DGKζ increased tyrosinase protein levels, but did not increase tyrosinase mRNA levels. Glycosidase digestion revealed that inhibition of DGK reduced only the mature form of tyrosinase and the decrease of tyrosinase resulting from DGK inhibition could be blocked partially by protease inhibitors. These results suggest that DGK regulates melanogenesis via modulation of the post-translational processing of tyrosinase, which may be related with the protein degradation machinery.
Collapse
Affiliation(s)
- Masakazu Kawaguchi
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | | | | | | | | |
Collapse
|