1
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Chen Y, Chen K, Zhu H, Qin H, Liu J, Cao X. Methyltransferase Setd2 prevents T cell-mediated autoimmune diseases via phospholipid remodeling. Proc Natl Acad Sci U S A 2024; 121:e2314561121. [PMID: 38359295 PMCID: PMC10895270 DOI: 10.1073/pnas.2314561121] [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: 08/23/2023] [Accepted: 12/16/2023] [Indexed: 02/17/2024] Open
Abstract
Coordinated metabolic reprogramming and epigenetic remodeling are critical for modulating T cell function and differentiation. However, how the epigenetic modification controls Th17/Treg cell balance via metabolic reprogramming remains obscure. Here, we find that Setd2, a histone H3K36 trimethyltransferase, suppresses Th17 development but promotes iTreg cell polarization via phospholipid remodeling. Mechanistically, Setd2 up-regulates transcriptional expression of lysophosphatidylcholine acyltransferase 4 (Lpcat4) via directly catalyzing H3K36me3 of Lpcat4 gene promoter in T cells. Lpcat4-mediated phosphatidylcholine PC(16:0,18:2) generation in turn limits endoplasmic reticulum stress and oxidative stress. These changes decrease HIF-1α transcriptional activity and thus suppress Th17 but enhance Treg development. Consistent with this regulatory paradigm, T cell deficiency of Setd2 aggravates neuroinflammation and demyelination in experimental autoimmune encephalomyelitis due to imbalanced Th17/Treg cell differentiation. Overall, our data reveal that Setd2 acts as an epigenetic brake for T cell-mediated autoimmunity through phospholipid remodeling, suggesting potential targets for treating neuroinflammatory diseases.
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Affiliation(s)
- Yali Chen
- Department of Immunology, Center for Immunotherapy, Institute of Basic Medical Sciences, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100005, China
- National Key Laboratory of Immunity and Inflammation, Institute of Immunology, Naval Medical University, Shanghai 200433, China
| | - Kun Chen
- Department of Immunology, Center for Immunotherapy, Institute of Basic Medical Sciences, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100005, China
- Translational Medical Center for Stem Cell Therapy, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200120, China
| | - Ha Zhu
- National Key Laboratory of Immunity and Inflammation, Institute of Immunology, Naval Medical University, Shanghai 200433, China
| | - Hua Qin
- Institute of Immunology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Juan Liu
- National Key Laboratory of Immunity and Inflammation, Institute of Immunology, Naval Medical University, Shanghai 200433, China
| | - Xuetao Cao
- Department of Immunology, Center for Immunotherapy, Institute of Basic Medical Sciences, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100005, China
- National Key Laboratory of Immunity and Inflammation, Institute of Immunology, Naval Medical University, Shanghai 200433, China
- Institute of Immunology, College of Life Sciences, Nankai University, Tianjin 300071, China
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2
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Jiang M, Wang Y, Yu X, He Y, Zheng X, Qin J, Gu Y, Li X, Shi Y, Ma X, Li J, Pu K. An image-based Abplex method for high-throughput GPCRs antibody discovery. Biotechnol J 2024; 19:e2300336. [PMID: 37941478 DOI: 10.1002/biot.202300336] [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: 07/12/2023] [Revised: 09/29/2023] [Accepted: 10/06/2023] [Indexed: 11/10/2023]
Abstract
As the field of antibody therapeutics advances rapidly, membrane proteins, particularly G protein-coupled receptors (GPCRs), have emerged as highly sought-after drug targets. However, the challenges associated with extracting membrane proteins have created a demand for effective antibody screening systems targeting these proteins. In this study, we propose developing an innovative antibody screening strategy (Abplex) based on high-content imaging. This approach leverages intact cells that express target membrane proteins, facilitating the presentation of proteins in their native conformation. Furthermore, it acquires both specific and non-specific binding signals in a single well, thereby bolstering the robustness of the outcomes. The technique involves just one step and can be completed within 50 min, enabling the analysis of a single sample in just one second. The amalgamation of dependable experimental findings, a simplified workflow, reduced hands-on time, and a swift analytical pace positions our method for superior throughput and precision when juxtaposed with traditional techniques such as CbELISA and FACS. Moreover, we introduce the concept of cell barcoding, wherein cells are labeled with different fluorescence spatial patterns. This feature allows for multiplexed detection to meet the needs of various experiments. The characteristics of Abplex promise to expedite GPCR-targeting antibody discovery, advance therapeutics and enable new disease treatments.
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Affiliation(s)
- Min Jiang
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei, China
- Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, China
| | - Yuanyuan Wang
- Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, China
| | - Xinke Yu
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X) & Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, China
| | - Yiran He
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei, China
- Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, China
| | - Xuewen Zheng
- Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, China
| | - Jingyi Qin
- Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, China
| | - Yayun Gu
- Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, China
| | - Xin Li
- Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, China
| | - Ying Shi
- Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, China
| | - Xiaochuan Ma
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X) & Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, China
| | - Jiong Li
- Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, China
| | - Kefeng Pu
- Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, China
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3
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Koh DHZ, Naito T, Na M, Yeap YJ, Rozario P, Zhong FL, Lim KL, Saheki Y. Visualization of accessible cholesterol using a GRAM domain-based biosensor. Nat Commun 2023; 14:6773. [PMID: 37880244 PMCID: PMC10600248 DOI: 10.1038/s41467-023-42498-7] [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: 06/23/2023] [Accepted: 10/12/2023] [Indexed: 10/27/2023] Open
Abstract
Cholesterol is important for membrane integrity and cell signaling, and dysregulation of the distribution of cellular cholesterol is associated with numerous diseases, including neurodegenerative disorders. While regulated transport of a specific pool of cholesterol, known as "accessible cholesterol", contributes to the maintenance of cellular cholesterol distribution and homeostasis, tools to monitor accessible cholesterol in live cells remain limited. Here, we engineer a highly sensitive accessible cholesterol biosensor by taking advantage of the cholesterol-sensing element (the GRAM domain) of an evolutionarily conserved lipid transfer protein, GRAMD1b. Using this cholesterol biosensor, which we call GRAM-W, we successfully visualize in real time the distribution of accessible cholesterol in many different cell types, including human keratinocytes and iPSC-derived neurons, and show differential dependencies on cholesterol biosynthesis and uptake for maintaining levels of accessible cholesterol. Furthermore, we combine GRAM-W with a dimerization-dependent fluorescent protein (ddFP) and establish a strategy for the ultrasensitive detection of accessible plasma membrane cholesterol. These tools will allow us to obtain important insights into the molecular mechanisms by which the distribution of cellular cholesterol is regulated.
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Affiliation(s)
- Dylan Hong Zheng Koh
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Tomoki Naito
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Minyoung Na
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Yee Jie Yeap
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Pritisha Rozario
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Franklin L Zhong
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
- Skin Research Institute of Singapore (SRIS), Singapore, 308232, Singapore
| | - Kah-Leong Lim
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
- National Neuroscience Institute, Singapore, 308433, Singapore
| | - Yasunori Saheki
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore.
- Institute of Resource Development and Analysis, Kumamoto University, Kumamoto, 860-0811, Japan.
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4
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Li Z, Zou J, Chen X. In Response to Precision Medicine: Current Subcellular Targeting Strategies for Cancer Therapy. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2209529. [PMID: 36445169 DOI: 10.1002/adma.202209529] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 11/08/2022] [Indexed: 05/26/2023]
Abstract
Emerging as a potent anticancer treatment, subcellular targeted cancer therapy has drawn increasing attention, bringing great opportunities for clinical application. Here, two targeting strategies for four main subcellular organelles (mitochondria, lysosome, endoplasmic reticulum, and nucleus), including molecule- and nanomaterial (inorganic nanoparticles, micelles, organic polymers, and others)-based targeted delivery or therapeutic strategies, are summarized. Phototherapy, chemotherapy, radiotherapy, immunotherapy, and "all-in-one" combination therapy are among the strategies covered in detail. Such materials are constructed based on the specific properties and relevant mechanisms of organelles, enabling the elimination of tumors by inducing dysfunction in the corresponding organelles or destroying specific structures. The challenges faced by organelle-targeting cancer therapies are also summarized. Looking forward, a paradigm for organelle-targeting therapy with enhanced therapeutic efficacy compared to current clinical approaches is envisioned.
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Affiliation(s)
- Zheng Li
- Departments of Diagnostic Radiology, Surgery, Chemical and Biomolecular Engineering, and Biomedical Engineering, Yong Loo Lin School of Medicine and Faculty of Engineering, National University of Singapore, Singapore, 119074, Singapore
- Nanomedicine Translational Research Program, NUS Center for Nanomedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
| | - Jianhua Zou
- Departments of Diagnostic Radiology, Surgery, Chemical and Biomolecular Engineering, and Biomedical Engineering, Yong Loo Lin School of Medicine and Faculty of Engineering, National University of Singapore, Singapore, 119074, Singapore
- Nanomedicine Translational Research Program, NUS Center for Nanomedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
| | - Xiaoyuan Chen
- Departments of Diagnostic Radiology, Surgery, Chemical and Biomolecular Engineering, and Biomedical Engineering, Yong Loo Lin School of Medicine and Faculty of Engineering, National University of Singapore, Singapore, 119074, Singapore
- Nanomedicine Translational Research Program, NUS Center for Nanomedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore
- Clinical Imaging Research Centre, Centre for Translational Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117599, Singapore
- Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Singapore
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5
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Hong K, Zhang Y, Yao L, Zhang J, Sheng X, Song L, Guo Y, Guo Y. Pan-cancer analysis of the angiotensin II receptor-associated protein as a prognostic and immunological gene predicting immunotherapy responses in pan-cancer. Front Cell Dev Biol 2022; 10:913684. [PMID: 36060798 PMCID: PMC9437438 DOI: 10.3389/fcell.2022.913684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 07/21/2022] [Indexed: 12/03/2022] Open
Abstract
Background: Understanding interior molecular mechanisms of tumorigenesis and cancer progression contributes to antitumor treatments. The angiotensin II receptor-associated protein (AGTRAP) has been confirmed to be related with metabolic products in metabolic diseases and can drive the progression of hepatocellular carcinoma and colon carcinoma. However, functions of AGTRAP in other kinds of cancers are unclear, and a pan-cancer analysis of AGTRAP has not been carried out. Methods and materials: We downloaded data from The Cancer Genome Atlas and Genotype-Tissue Expression dataset and The Human Protein Atlas databases and then used R software (version 4.1.1) and several bioinformatic tools to conduct the analysis. Results: In our study, we evaluated the expression of AGTRAP in cancers, such as high expression in breast cancer, lung adenocarcinoma, and glioma and low expression in kidney chromophobe. Furthermore, our study revealed that high expression of AGTRAP is significantly related with poor prognosis in glioma, liver cancer, kidney chromophobe, and so on. We also explored the putative functional mechanisms of AGTRAP across pan-cancer, such as endoplasmic reticulum pathway, endocytosis pathway, and JAK-STAT signaling pathway. In addition, the connection between AGTRAP and tumor microenvironment, tumor mutation burden, and immune-related genes was proven. Conclusion: Our study provided comprehensive evidence of the roles of AGTRAP in different kinds of cancers and supported the relationship of AGTRAP and tumorous immunity.
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Affiliation(s)
- Kai Hong
- Department of Thyroid and Breast Surgery, Ningbo City First Hospital, Ningbo, Zhejiang, China
- Medicine School, Ningbo University, Ningbo, Zhejiang, China
| | - Yingjue Zhang
- Department of Molecular Pathology, Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Lingli Yao
- Department of Thyroid and Breast Surgery, Ningbo City First Hospital, Ningbo, Zhejiang, China
- Medicine School, Ningbo University, Ningbo, Zhejiang, China
| | - Jiabo Zhang
- Department of Thyroid and Breast Surgery, Ningbo City First Hospital, Ningbo, Zhejiang, China
| | - Xianneng Sheng
- Department of Thyroid and Breast Surgery, Ningbo City First Hospital, Ningbo, Zhejiang, China
| | - Lihua Song
- Department of Thyroid and Breast Surgery, Ningbo City First Hospital, Ningbo, Zhejiang, China
- Medicine School, Ningbo University, Ningbo, Zhejiang, China
| | - Yu Guo
- Department of Thyroid and Breast Surgery, Ningbo City First Hospital, Ningbo, Zhejiang, China
- *Correspondence: Yu Guo, ; Yangyang Guo,
| | - Yangyang Guo
- Department of Thyroid and Breast Surgery, Ningbo City First Hospital, Ningbo, Zhejiang, China
- *Correspondence: Yu Guo, ; Yangyang Guo,
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6
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Thomas FB, Omnus DJ, Bader JM, Chung GH, Kono N, Stefan CJ. Tricalbin proteins regulate plasma membrane phospholipid homeostasis. Life Sci Alliance 2022; 5:5/8/e202201430. [PMID: 35440494 PMCID: PMC9018018 DOI: 10.26508/lsa.202201430] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/03/2022] [Accepted: 04/04/2022] [Indexed: 12/26/2022] Open
Abstract
The evolutionarily conserved extended synaptotagmin (E-Syt) proteins are calcium-activated lipid transfer proteins that function at contacts between the ER and plasma membrane (ER-PM contacts). However, roles of the E-Syt family members in PM lipid organisation remain incomplete. Among the E-Syt family, the yeast tricalbin (Tcb) proteins are essential for PM integrity upon heat stress, but it is not known how they contribute to PM maintenance. Using quantitative lipidomics and microscopy, we find that the Tcb proteins regulate phosphatidylserine homeostasis at the PM. Moreover, upon heat-induced membrane stress, Tcb3 co-localises with the PM protein Sfk1 that is implicated in PM phospholipid asymmetry and integrity. The Tcb proteins also control the PM targeting of the known phosphatidylserine effector Pkc1 upon heat-induced stress. Phosphatidylserine has evolutionarily conserved roles in PM organisation, integrity, and repair. We propose that phospholipid regulation is an ancient essential function of E-Syt family members required for PM integrity.
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Affiliation(s)
- Ffion B Thomas
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Deike J Omnus
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Jakob M Bader
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Gary Hc Chung
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Nozomu Kono
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Christopher J Stefan
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
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7
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Tanguy E, Wolf A, Wang Q, Chasserot-Golaz S, Ory S, Gasman S, Vitale N. Phospholipase D1-generated phosphatidic acid modulates secretory granule trafficking from biogenesis to compensatory endocytosis in neuroendocrine cells. Adv Biol Regul 2021; 83:100844. [PMID: 34876384 DOI: 10.1016/j.jbior.2021.100844] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 11/16/2022]
Abstract
Calcium-regulated exocytosis is a multi-step process that allows specialized secretory cells to release informative molecules such as neurotransmitters, neuropeptides, and hormones for intercellular communication. The biogenesis of secretory vesicles from the Golgi cisternae is followed by their transport towards the cell periphery and their docking and fusion to the exocytic sites of the plasma membrane allowing release of vesicular content. Subsequent compensatory endocytosis of the protein and lipidic constituents of the vesicles maintains cell homeostasis. Despite the fact that lipids represent the majority of membrane constituents, little is known about their contribution to these processes. Using a combination of electrochemical measurement of single chromaffin cell catecholamine secretion and electron microscopy of roof-top membrane sheets associated with genetic, silencing and pharmacological approaches, we recently reported that diverse phosphatidic acid (PA) species regulates catecholamine release efficiency by controlling granule docking and fusion kinetics. The enzyme phospholipase D1 (PLD1), producing PA from phosphatidylcholine, seems to be the major responsible of these effects in this model. Here, we extended this work using spinning disk confocal microscopy showing that inhibition of PLD activity also reduced the velocity of granules undergoing a directed motion. Furthermore, a dopamine β-hydroxylase (DβH) internalization assay revealed that PA produced by PLD is required for an optimal recovery of vesicular membrane content by compensatory endocytosis. Thus, among numerous roles that have been attributed to PA our work gives core to the key regulatory role in secretion that has been proposed in different cell models. Few leads to explain these multiple functions of PA along the secretory pathway are discussed.
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Affiliation(s)
- Emeline Tanguy
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France
| | - Alexander Wolf
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France
| | - Qili Wang
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France
| | - Sylvette Chasserot-Golaz
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France
| | - Stéphane Ory
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France
| | - Stéphane Gasman
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France
| | - Nicolas Vitale
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France.
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8
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Jeyasimman D, Ercan B, Dharmawan D, Naito T, Sun J, Saheki Y. PDZD-8 and TEX-2 regulate endosomal PI(4,5)P 2 homeostasis via lipid transport to promote embryogenesis in C. elegans. Nat Commun 2021; 12:6065. [PMID: 34663803 PMCID: PMC8523718 DOI: 10.1038/s41467-021-26177-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 09/22/2021] [Indexed: 11/10/2022] Open
Abstract
Different types of cellular membranes have unique lipid compositions that are important for their functional identity. PI(4,5)P2 is enriched in the plasma membrane where it contributes to local activation of key cellular events, including actomyosin contraction and cytokinesis. However, how cells prevent PI(4,5)P2 from accumulating in intracellular membrane compartments, despite constant intermixing and exchange of lipid membranes, is poorly understood. Using the C. elegans early embryo as our model system, we show that the evolutionarily conserved lipid transfer proteins, PDZD-8 and TEX-2, act together with the PI(4,5)P2 phosphatases, OCRL-1 and UNC-26/synaptojanin, to prevent the build-up of PI(4,5)P2 on endosomal membranes. In the absence of these four proteins, large amounts of PI(4,5)P2 accumulate on endosomes, leading to embryonic lethality due to ectopic recruitment of proteins involved in actomyosin contractility. PDZD-8 localizes to the endoplasmic reticulum and regulates endosomal PI(4,5)P2 levels via its lipid harboring SMP domain. Accumulation of PI(4,5)P2 on endosomes is accompanied by impairment of their degradative capacity. Thus, cells use multiple redundant systems to maintain endosomal PI(4,5)P2 homeostasis.
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Affiliation(s)
- Darshini Jeyasimman
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Bilge Ercan
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Dennis Dharmawan
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Tomoki Naito
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Jingbo Sun
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Yasunori Saheki
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore.
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, 860-8556, Japan.
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9
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Endoplasmic reticulum stress and unfolded protein response in cardiovascular diseases. Nat Rev Cardiol 2021; 18:499-521. [PMID: 33619348 DOI: 10.1038/s41569-021-00511-w] [Citation(s) in RCA: 278] [Impact Index Per Article: 92.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/11/2021] [Indexed: 02/07/2023]
Abstract
Cardiovascular diseases (CVDs), such as ischaemic heart disease, cardiomyopathy, atherosclerosis, hypertension, stroke and heart failure, are among the leading causes of morbidity and mortality worldwide. Although specific CVDs and the associated cardiometabolic abnormalities have distinct pathophysiological and clinical manifestations, they often share common traits, including disruption of proteostasis resulting in accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER). ER proteostasis is governed by the unfolded protein response (UPR), a signalling pathway that adjusts the protein-folding capacity of the cell to sustain the cell's secretory function. When the adaptive UPR fails to preserve ER homeostasis, a maladaptive or terminal UPR is engaged, leading to the disruption of ER integrity and to apoptosis. ER stress functions as a double-edged sword, with long-term ER stress resulting in cellular defects causing disturbed cardiovascular function. In this Review, we discuss the distinct roles of the UPR and ER stress response as both causes and consequences of CVD. We also summarize the latest advances in our understanding of the importance of the UPR and ER stress in the pathogenesis of CVD and discuss potential therapeutic strategies aimed at restoring ER proteostasis in CVDs.
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10
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Ercan B, Naito T, Koh DHZ, Dharmawan D, Saheki Y. Molecular basis of accessible plasma membrane cholesterol recognition by the GRAM domain of GRAMD1b. EMBO J 2021; 40:e106524. [PMID: 33604931 PMCID: PMC7957428 DOI: 10.15252/embj.2020106524] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 12/16/2020] [Accepted: 01/08/2021] [Indexed: 12/25/2022] Open
Abstract
Cholesterol is essential for cell physiology. Transport of the "accessible" pool of cholesterol from the plasma membrane (PM) to the endoplasmic reticulum (ER) by ER-localized GRAMD1 proteins (GRAMD1a/1b/1c) contributes to cholesterol homeostasis. However, how cells detect accessible cholesterol within the PM remains unclear. We show that the GRAM domain of GRAMD1b, a coincidence detector for anionic lipids, including phosphatidylserine (PS), and cholesterol, possesses distinct but synergistic sites for sensing accessible cholesterol and anionic lipids. We find that a mutation within the GRAM domain of GRAMD1b that is associated with intellectual disability in humans specifically impairs cholesterol sensing. In addition, we identified another point mutation within this domain that enhances cholesterol sensitivity without altering its PS sensitivity. Cell-free reconstitution and cell-based assays revealed that the ability of the GRAM domain to sense accessible cholesterol regulates membrane tethering and determines the rate of cholesterol transport by GRAMD1b. Thus, cells detect the codistribution of accessible cholesterol and anionic lipids in the PM and fine-tune the non-vesicular transport of PM cholesterol to the ER via GRAMD1s.
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Affiliation(s)
- Bilge Ercan
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Tomoki Naito
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | | | - Dennis Dharmawan
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Yasunori Saheki
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.,Institute of Resource Development and Analysis, Kumamoto University, Kumamoto, Japan
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11
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Lucken-Ardjomande Häsler S, Vallis Y, Pasche M, McMahon HT. GRAF2, WDR44, and MICAL1 mediate Rab8/10/11-dependent export of E-cadherin, MMP14, and CFTR ΔF508. J Cell Biol 2021; 219:151714. [PMID: 32344433 PMCID: PMC7199855 DOI: 10.1083/jcb.201811014] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 11/07/2019] [Accepted: 02/26/2020] [Indexed: 02/07/2023] Open
Abstract
In addition to the classical pathway of secretion, some transmembrane proteins reach the plasma membrane through alternative routes. Several proteins transit through endosomes and are exported in a Rab8-, Rab10-, and/or Rab11-dependent manner. GRAFs are membrane-binding proteins associated with tubules and vesicles. We found extensive colocalization of GRAF1b/2 with Rab8a/b and partial with Rab10. We identified MICAL1 and WDR44 as direct GRAF-binding partners. MICAL1 links GRAF1b/2 to Rab8a/b and Rab10, and WDR44 binds Rab11. Endogenous WDR44 labels a subset of tubular endosomes, which are closely aligned with the ER via binding to VAPA/B. With its BAR domain, GRAF2 can tubulate membranes, and in its absence WDR44 tubules are not observed. We show that GRAF2 and WDR44 are essential for the export of neosynthesized E-cadherin, MMP14, and CFTR ΔF508, three proteins whose exocytosis is sensitive to ER stress. Overexpression of dominant negative mutants of GRAF1/2, WDR44, and MICAL1 also interferes with it, facilitating future studies of Rab8/10/11-dependent exocytic pathways of central importance in biology.
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Affiliation(s)
| | - Yvonne Vallis
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| | - Mathias Pasche
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| | - Harvey T McMahon
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
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12
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Abstract
Excess adiposity is a risk factor for several cancer types. This is likely due to complex mechanisms including alterations in the lipid milieu that plays a pivotal role in multiple aspects of carcinogenesis. Here we consider the direct role of lipids in regulating well-known hallmarks of cancer. Furthermore, we suggest that obesity-associated remodelling of membranes and organelles drives cancer cell proliferation and invasion. Identification of cancer-related lipid-mediated mechanisms amongst the broad metabolic disturbances due to excess adiposity is central to the identification of novel and more efficacious prevention and intervention strategies.
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Affiliation(s)
- J Molendijk
- QIMR Berghofer Medical Research Institute, Herston, Brisbane, 4006, Australia.
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Naito T, Ercan B, Krshnan L, Triebl A, Koh DHZ, Wei FY, Tomizawa K, Torta FT, Wenk MR, Saheki Y. Movement of accessible plasma membrane cholesterol by the GRAMD1 lipid transfer protein complex. eLife 2019; 8:51401. [PMID: 31724953 PMCID: PMC6905856 DOI: 10.7554/elife.51401] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 11/13/2019] [Indexed: 12/18/2022] Open
Abstract
Cholesterol is a major structural component of the plasma membrane (PM). The majority of PM cholesterol forms complexes with other PM lipids, making it inaccessible for intracellular transport. Transition of PM cholesterol between accessible and inaccessible pools maintains cellular homeostasis, but how cells monitor the accessibility of PM cholesterol remains unclear. We show that endoplasmic reticulum (ER)-anchored lipid transfer proteins, the GRAMD1s, sense and transport accessible PM cholesterol to the ER. GRAMD1s bind to one another and populate ER-PM contacts by sensing a transient expansion of the accessible pool of PM cholesterol via their GRAM domains. They then facilitate the transport of this cholesterol via their StART-like domains. Cells that lack all three GRAMD1s exhibit striking expansion of the accessible pool of PM cholesterol as a result of less efficient PM to ER transport of accessible cholesterol. Thus, GRAMD1s facilitate the movement of accessible PM cholesterol to the ER in order to counteract an acute increase of PM cholesterol, thereby activating non-vesicular cholesterol transport. The human body contains trillions of cells. At the outer edge of each cell is the plasma membrane, which protects the cell from the external environment. This membrane is mostly made of fatty molecules known as lipids and about half of these lipids are specifically cholesterol. Human cells can either take up cholesterol that were obtained via the diet or produce it within a compartment of the cell called the endoplasmic reticulum. Cells need to monitor the cholesterol levels in both the endoplasmic reticulum and the plasma membrane in order to regulate the uptake or production of this lipid. For example, if there is too much of cholesterol in the plasma membrane, then the cell transports some to the endoplasmic reticulum to tell it to shut down cholesterol production. However, how these different areas of the cell communicate with each other, and transport cholesterol, has remained unclear. Naito et al. set out to look for key regulators of cholesterol transport and identified a group of endoplasmic reticulum proteins called GRAMD1 proteins. Cholesterol in the plasma membrane is either accessible or inaccessible, meaning it either can or cannot be moved back into the cell. The GRAMD1 proteins sense accessible cholesterol, and experiments with human cells grown in the laboratory showed that, specifically, the GRAMD1 proteins work together in a complex to sense accessible cholesterol at or near the plasma membrane. One particular part of the protein senses when the amount of accessible cholesterol reaches a certain level at the plasma membrane; when this threshold is reached, the complex flips a switch to start the transport of cholesterol to the endoplasmic reticulum and tell it to shut down cholesterol production. This coupling of sensing and transporting lipids by one protein complex also helps maintain the right ratio of accessible and inaccessible cholesterol in the plasma membrane to prevent cells from activating unwanted cell-signaling events. Getting rid of the GRAMD1 proteins in cells, or removing sensing part of these proteins, leads to inefficient transport of cholesterol. A better understanding of how GRAMD1 proteins sense the accessibility of cholesterol could potentially help identify new approaches to control cholesterol transport inside cells. This may in turn eventually lead to new treatments that counteract the defects in cholesterol metabolism seen in some forms of neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease.
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Affiliation(s)
- Tomoki Naito
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Bilge Ercan
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Logesvaran Krshnan
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Alexander Triebl
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Dylan Hong Zheng Koh
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Fan-Yan Wei
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Kazuhito Tomizawa
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Federico Tesio Torta
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Markus R Wenk
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Yasunori Saheki
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.,Institute of Resource Development and Analysis, Kumamoto University, Kumamoto, Japan
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