551
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Zhang L, Hu W, Cho CH, Chan FK, Yu J, Fitzgerald JR, Cheung CK, Xiao ZG, Shen J, Li LF, Li MX, Wu JC, Ling TK, Chan JY, Ko H, Tse G, Ng SC, Yu S, Wang MH, Gin T, Ashktorab H, Smoot DT, Wong SH, Chan MT, Wu WK. Reduced lysosomal clearance of autophagosomes promotes survival and colonization of Helicobacter pylori. J Pathol 2018; 244:432-444. [PMID: 29327342 DOI: 10.1002/path.5033] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 11/20/2017] [Accepted: 01/04/2018] [Indexed: 01/25/2023]
Abstract
Evasion of autophagy is key for intracellular survival of bacteria in host cells, but its involvement in persistent infection by Helicobacter pylori, a bacterium identified to invade gastric epithelial cells, remains obscure. The aim of this study was to functionally characterize the role of autophagy in H. pylori infection. Autophagy was assayed in H. pylori-infected human gastric epithelium and the functional role of autophagy was determined via genetic or pharmacological ablation of autophagy in mouse and cell line models of H. pylori infection. Here, we showed that H. pylori inhibited lysosomal function and thereby promoted the accumulation of autophagosomes in gastric epithelial cells. Importantly, inhibiting autophagosome formation by pharmacological inhibitors or genetic ablation of BECN1 or ATG5 reduced H. pylori intracellular survival, whereas inhibition of lysosomal functions exerted an opposite effect. Further experiments demonstrated that H. pylori inhibited lysosomal acidification and the retrograde trafficking of mannose-6-phosphate receptors, both of which are known to positively regulate lysosomal function. We conclude that H. pylori subverts autophagy into a pro-survival mechanism through inhibition of lysosomal clearance of autophagosomes. Disruption of autophagosome formation offers a novel strategy to reduce H. pylori colonization in human stomachs. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Lin Zhang
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong SAR, PR China.,Institute of Digestive Diseases, State Key Laboratory of Digestive Diseases, LKS Institute of Health Sciences, CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong SAR, PR China.,Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, PR China
| | - Wei Hu
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - Chi H Cho
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, PR China.,School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - Francis Kl Chan
- Institute of Digestive Diseases, State Key Laboratory of Digestive Diseases, LKS Institute of Health Sciences, CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong SAR, PR China.,Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - Jun Yu
- Institute of Digestive Diseases, State Key Laboratory of Digestive Diseases, LKS Institute of Health Sciences, CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong SAR, PR China.,Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | | | - Cynthia Ky Cheung
- Institute of Digestive Diseases, State Key Laboratory of Digestive Diseases, LKS Institute of Health Sciences, CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong SAR, PR China.,Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - Zhan G Xiao
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, PR China
| | - Jing Shen
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, PR China
| | - Long F Li
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, PR China
| | - Ming X Li
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, PR China
| | - Justin Cy Wu
- Institute of Digestive Diseases, State Key Laboratory of Digestive Diseases, LKS Institute of Health Sciences, CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong SAR, PR China.,Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - Thomas Kw Ling
- Department of Microbiology, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - Jason Yk Chan
- Department of Otorhinolaryngology, Head and Neck Surgery, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - Ho Ko
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - Gary Tse
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - Siew C Ng
- Institute of Digestive Diseases, State Key Laboratory of Digestive Diseases, LKS Institute of Health Sciences, CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong SAR, PR China.,Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - Sidney Yu
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - Maggie Ht Wang
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - Tony Gin
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - Hassan Ashktorab
- Department of Medicine, Howard University, Washington, DC, USA.,Cancer Center, Howard University, Washington, DC, USA.,Howard University Hospital, Howard University, Washington, DC, USA
| | - Duane T Smoot
- Department of Internal Medicine, Meharry Medical College, Nashville, TN, USA
| | - Sunny H Wong
- Institute of Digestive Diseases, State Key Laboratory of Digestive Diseases, LKS Institute of Health Sciences, CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong SAR, PR China.,Department of Otorhinolaryngology, Head and Neck Surgery, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - Matthew Tv Chan
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong SAR, PR China
| | - William Kk Wu
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong SAR, PR China.,Institute of Digestive Diseases, State Key Laboratory of Digestive Diseases, LKS Institute of Health Sciences, CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong SAR, PR China
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552
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He H, Ye Z, Zheng Y, Xu X, Guo C, Xiao Y, Yang W, Qian X, Yang Y. Super-resolution imaging of lysosomes with a nitroso-caged rhodamine. Chem Commun (Camb) 2018; 54:2842-2845. [PMID: 29393323 DOI: 10.1039/c7cc08886h] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Caged-fluorophores are potentially suitable for photo-activated localization microscopy (PALM) for super-resolution imaging. N-Nitroso is a simple and robust photo-cage with biocompatible nitric oxide as the only byproduct upon photolysis. We herein reported a novel PALM probe (NOR535) for super-resolution imaging of lysosomes with high localization precision.
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Affiliation(s)
- Haihong He
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai, 200237, China.
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553
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She J, Guo J, Chen Q, Zeng W, Jiang Y, Bai XC. Structural insights into the voltage and phospholipid activation of the mammalian TPC1 channel. Nature 2018; 556:130-134. [PMID: 29562233 PMCID: PMC5886804 DOI: 10.1038/nature26139] [Citation(s) in RCA: 137] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 02/19/2018] [Indexed: 01/09/2023]
Abstract
Organellar two-pore channels (TPCs) function as a homodimer with each subunit containing two homologous Shaker-like 6-TM repeats1. They belong to the voltage-gated ion channel superfamily2 and are ubiquitously expressed in animals and plants3,4. Mammalian TPC1 and TPC2 are localized to the endolysosomal membrane and play critical roles in regulating the physiological functions of these acidic organelles5–7. Here we present the cryo-EM structures of mouse TPC1 (MmTPC1), a voltage-dependent, phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2) activated Na+ selective channel, in both the apo closed and ligand-bound open states which, combined with functional analysis, provide comprehensive structural insights into the selectivity and gating mechanisms of mammalian TPC channels. The channel has a coin slot-shaped ion pathway in the filter that defines the selectivity of mammalian TPCs. Only the voltage sensing domain from the second 6-TM domain confers voltage dependence to MmTPC1. Endolysosome-specific PtdIns(3,5)P2 binds to the first 6-TM domain and activates the channel under depolarizing membrane potential. Structural comparison between the apo and PtdIns(3,5)P2-bound structures elucidates the interplay between voltage and ligand in channel activation. In light of the emerging importance of phosphoinositide regulation of ion channels, the MmTPC1 structures exemplify the lipid binding and regulation in a 6-TM voltage-gated channel.
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Affiliation(s)
- Ji She
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA
| | - Jiangtao Guo
- Department of Biophysics, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Qingfeng Chen
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA
| | - Weizhong Zeng
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA
| | - Youxing Jiang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9040, USA
| | - Xiao-Chen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8816, USA.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9039, USA
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554
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Abstract
Cells utilize calcium ions (Ca2+) to signal almost all aspects of cellular life, ranging from cell proliferation to cell death, in a spatially and temporally regulated manner. A key aspect of this regulation is the compartmentalization of Ca2+ in various cytoplasmic organelles that act as intracellular Ca2+ stores. Whereas Ca2+ release from the large-volume Ca2+ stores, such as the endoplasmic reticulum (ER) and Golgi apparatus, are preferred for signal transduction, Ca2+ release from the small-volume individual vesicular stores that are dispersed throughout the cell, such as lysosomes, may be more useful in local regulation, such as membrane fusion and individualized vesicular movements. Conceivably, these two types of Ca2+ stores may be established, maintained or refilled via distinct mechanisms. ER stores are refilled through sustained Ca2+ influx at ER-plasma membrane (PM) membrane contact sites (MCSs). In this review, we discuss the release and refilling mechanisms of intracellular small vesicular Ca2+ stores, with a special focus on lysosomes. Recent imaging studies of Ca2+ release and organelle MCSs suggest that Ca2+ exchange may occur between two types of stores, such that the small stores acquire Ca2+ from the large stores via ER-vesicle MCSs. Hence vesicular stores like lysosomes may be viewed as secondary Ca2+ stores in the cell.
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555
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Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) coordinates cellular growth and metabolism with environmental inputs to ensure that cells grow only under favourable conditions. When active, mTORC1 stimulates biosynthetic pathways including protein, lipid and nucleotide synthesis and inhibits cellular catabolism through repression of the autophagic pathway, thereby promoting cell growth and proliferation. The recruitment of mTORC1 to the lysosomal surface has been shown to be essential for its activation. This finding has significantly enhanced our knowledge of mTORC1 regulation and has focused the attention of the field on the lysosome as a signalling hub which coordinates several homeostatic pathways. The intriguing localisation of mTORC1 to the cellular organelle that plays a crucial role in catabolism enables mTORC1 to feedback to autophagy and lysosomal biogenesis, thus leading mTORC1 to enact precise spatial and temporal control of cell growth. This review will cover the signalling interactions which take place on the surface of lysosomes and the cross-talk which exists between mTORC1 activity and lysosomal function.
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Affiliation(s)
- Yoana Rabanal-Ruiz
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE4 5PL, UK.
| | - Viktor I Korolchuk
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE4 5PL, UK.
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556
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Sterea AM, Almasi S, El Hiani Y. The hidden potential of lysosomal ion channels: A new era of oncogenes. Cell Calcium 2018; 72:91-103. [PMID: 29748137 DOI: 10.1016/j.ceca.2018.02.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 02/28/2018] [Accepted: 02/28/2018] [Indexed: 01/14/2023]
Abstract
Lysosomes serve as the control centre for cellular clearance. These membrane-bound organelles receive biomolecules destined for degradation from intracellular and extracellular pathways; thus, facilitating the production of energy and shaping the fate of the cell. At the base of their functionality are the lysosomal ion channels which mediate the function of the lysosome through the modulation of ion influx and efflux. Ion channels form pores in the membrane of lysosomes and allow the passage of ions, a seemingly simple task which harbours the potential of overthrowing the cell's stability. Considered the master regulators of ion homeostasis, these integral membrane proteins enable the proper operation of the lysosome. Defects in the structure or function of these ion channels lead to the development of lysosomal storage diseases, neurodegenerative diseases and cancer. Although more than 50 years have passed since their discovery, lysosomes are not yet fully understood, with their ion channels being even less well characterized. However, significant improvements have been made in the development of drugs targeted against these ion channels as a means of combating diseases. In this review, we will examine how Ca2+, K+, Na+ and Cl- ion channels affect the function of the lysosome, their involvement in hereditary and spontaneous diseases, and current ion channel-based therapies.
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Affiliation(s)
- Andra M Sterea
- Departments of Physiology & Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Shekoufeh Almasi
- Departments of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Yassine El Hiani
- Departments of Physiology & Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada.
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557
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Targeting of cathepsin C induces autophagic dysregulation that directs ER stress mediated cellular cytotoxicity in colorectal cancer cells. Cell Signal 2018; 46:92-102. [PMID: 29501728 DOI: 10.1016/j.cellsig.2018.02.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 02/28/2018] [Accepted: 02/28/2018] [Indexed: 12/14/2022]
Abstract
As Autophagy is a pivotal mechanism of cancer cell survival and the development of chemotherapeutic resistance; therefore, new approaches are warranted for its targeting which may be fulfilled by cathepsins regulation. Amongst cathepsins, cathepsin C (CTSC) is highly expressed in various cancers and possesses significant therapeutic potential in autoimmune disorders; however, its role in colorectal cancer has not been explored. Herein, we aimed to investigate the role of CTSC in autophagy regulation mediated colorectal carcinoma cell proliferation. Cathepsin C targeting through inhibitors/siRNA leads to the accumulation of light chain 3 II and p62 without affecting the lysosomal integrity, revealed dysfunctional autolysosomal degradation which is also substantiated by proteolytic studies. Cathepsin C inhibition showed comparable autophagy blockade with E64d and augmented the autophagy blockade mediated by bafilomycin. Loss of CTSC function also induced ER stress-mediated JNK phosphorylation accompanied by the translocation of mitochondrial cyt c followed by apoptotic cell death in colorectal carcinoma cells. Taken together, the study reveals that CTSC targeting plays a key role in the regulation of autophagy mediated colorectal cancer cell proliferation. Further investigations are required to determine the functional role of CTSC in other tumors also which may have implications for the therapeutic prevention of cancer in the future.
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558
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Jin EJ, Kiral FR, Hiesinger PR. The where, what, and when of membrane protein degradation in neurons. Dev Neurobiol 2018; 78:283-297. [PMID: 28884504 PMCID: PMC5816708 DOI: 10.1002/dneu.22534] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 09/01/2017] [Accepted: 09/04/2017] [Indexed: 12/20/2022]
Abstract
Membrane protein turnover and degradation are required for the function and health of all cells. Neurons may live for the entire lifetime of an organism and are highly polarized cells with spatially segregated axonal and dendritic compartments. Both longevity and morphological complexity represent challenges for regulated membrane protein degradation. To investigate how neurons cope with these challenges, an increasing number of recent studies investigated local, cargo-specific protein sorting, and degradation at axon terminals and in dendritic processes. In this review, we explore the current answers to the ensuing questions of where, what, and when membrane proteins are degraded in neurons. © 2017 The Authors Developmental Neurobiology Published by Wiley Periodicals, Inc. Develop Neurobiol 78: 283-297, 2018.
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Affiliation(s)
- Eugene Jennifer Jin
- Division of NeurobiologyInstitute for Biology, Freie Universität Berlin14195 BerlinGermany
- Graduate School of Biomedical SciencesUniversity of Texas Southwestern Medical CenterDallasTX75390USA
| | - Ferdi Ridvan Kiral
- Division of NeurobiologyInstitute for Biology, Freie Universität Berlin14195 BerlinGermany
| | - Peter Robin Hiesinger
- Division of NeurobiologyInstitute for Biology, Freie Universität Berlin14195 BerlinGermany
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559
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Keeling E, Lotery AJ, Tumbarello DA, Ratnayaka JA. Impaired Cargo Clearance in the Retinal Pigment Epithelium (RPE) Underlies Irreversible Blinding Diseases. Cells 2018; 7:E16. [PMID: 29473871 PMCID: PMC5850104 DOI: 10.3390/cells7020016] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Revised: 02/20/2018] [Accepted: 02/22/2018] [Indexed: 01/09/2023] Open
Abstract
Chronic degeneration of the Retinal Pigment Epithelium (RPE) is a precursor to pathological changes in the outer retina. The RPE monolayer, which lies beneath the neuroretina, daily internalises and digests large volumes of spent photoreceptor outer segments. Impaired cargo handling and processing in the endocytic/phagosome and autophagy pathways lead to the accumulation of lipofuscin and pyridinium bis-retinoid A2E aggregates and chemically modified compounds such as malondialdehyde and 4-hydroxynonenal within RPE. These contribute to increased proteolytic and oxidative stress, resulting in irreversible damage to post-mitotic RPE cells and development of blinding conditions such as age-related macular degeneration, Stargardt disease and choroideremia. Here, we review how impaired cargo handling in the RPE results in their dysfunction, discuss new findings from our laboratory and consider how newly discovered roles for lysosomes and the autophagy pathway could provide insights into retinopathies. Studies of these dynamic, molecular events have also been spurred on by recent advances in optics and imaging technology. Mechanisms underpinning lysosomal impairment in other degenerative conditions including storage disorders, α-synuclein pathologies and Alzheimer's disease are also discussed. Collectively, these findings help transcend conventional understanding of these intracellular compartments as simple waste disposal bags to bring about a paradigm shift in the way lysosomes are perceived.
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Affiliation(s)
- Eloise Keeling
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton SO16 6YD, UK.
| | - Andrew J Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton SO16 6YD, UK.
- Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK.
| | - David A Tumbarello
- Biological Sciences, Faculty of Natural & Environmental Sciences, Life Science Building 85, University of Southampton, Highfield Campus, Southampton SO17 1BJ, UK.
| | - J Arjuna Ratnayaka
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton SO16 6YD, UK.
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560
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Jin ZC, Kitajima T, Dong W, Huang YF, Ren WW, Guan F, Chiba Y, Gao XD, Fujita M. Genetic disruption of multiple α1,2-mannosidases generates mammalian cells producing recombinant proteins with high-mannose-type N-glycans. J Biol Chem 2018; 293:5572-5584. [PMID: 29475941 DOI: 10.1074/jbc.m117.813030] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 02/04/2018] [Indexed: 12/27/2022] Open
Abstract
Recombinant therapeutic proteins are becoming very important pharmaceutical agents for treating intractable diseases. Most biopharmaceutical proteins are produced in mammalian cells because this ensures correct folding and glycosylation for protein stability and function. However, protein production in mammalian cells has several drawbacks, including heterogeneity of glycans attached to the produced protein. In this study, we established cell lines with high-mannose-type N-linked, low-complexity glycans. We first knocked out two genes encoding Golgi mannosidases (MAN1A1 and MAN1A2) in HEK293 cells. Single knockout (KO) cells did not exhibit changes in N-glycan structures, whereas double KO cells displayed increased high-mannose-type and decreased complex-type glycans. In our effort to eliminate the remaining complex-type glycans, we found that knocking out a gene encoding the endoplasmic reticulum mannosidase I (MAN1B1) in the double KO cells reduced most of the complex-type glycans. In triple KO (MAN1A1, MAN1A2, and MAN1B1) cells, Man9GlcNAc2 and Man8GlcNAc2 were the major N-glycan structures. Therefore, we expressed two lysosomal enzymes, α-galactosidase-A and lysosomal acid lipase, in the triple KO cells and found that the glycans on these enzymes were sensitive to endoglycosidase H treatment. The N-glycan structures on recombinant proteins expressed in triple KO cells were simplified and changed from complex types to high-mannose types at the protein level. Our results indicate that the triple KO HEK293 cells are suitable for producing recombinant proteins, including lysosomal enzymes with high-mannose-type N-glycans.
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Affiliation(s)
- Ze-Cheng Jin
- From the Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Toshihiko Kitajima
- From the Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Weijie Dong
- the College of Basic Medical Sciences, Dalian Medical University, Dalian 116044, Liaoning, China, and
| | - Yi-Fan Huang
- From the Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Wei-Wei Ren
- From the Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Feng Guan
- From the Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Yasunori Chiba
- the Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan
| | - Xiao-Dong Gao
- From the Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China,
| | - Morihisa Fujita
- From the Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China,
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561
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Zhang N, Liu X, Liu L, Deng Z, Zeng Q, Pang W, Liu Y, Song D, Deng H. Glycogen synthase kinase-3β inhibition promotes lysosome-dependent degradation of c-FLIP L in hepatocellular carcinoma. Cell Death Dis 2018; 9:230. [PMID: 29445085 PMCID: PMC5833564 DOI: 10.1038/s41419-018-0309-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 01/02/2018] [Accepted: 01/11/2018] [Indexed: 12/16/2022]
Abstract
Glycogen synthase kinase-3β (GSK-3β) is a ubiquitously expressed serine/threonine kinase involved in a variety of functions ranging from the control of glycogen metabolism to transcriptional regulation. We recently demonstrated that GSK-3β inhibition triggered ASK1-JNK-dependent apoptosis in human hepatocellular carcinoma (HCC) cells. However, the comprehensive picture of downstream GSK-3β-regulated pathways/functions remains elusive. In this study, we showed that GSK-3β was aberrantly activated in HCC. Pharmacological inhibition and genetic depletion of GSK-3β suppressed the growth and induced caspase-dependent apoptosis in HCC cells. In addition, GSK-3β inhibition-induced apoptosis through downregulation of c-FLIPL in HCC, which was caused by biogenesis of functional lysosomes and subsequently c-FLIPL translocated to lysosome for degradation. This induction of the lysosome-dependent c-FLIPL degradation was associated with nuclear translocation of transcription factor EB (TFEB), a master regulator of lysosomal biogenesis. Moreover, GSK-3β inhibition-induced TFEB translocation acts through activation of AMPK and subsequently suppression of mTOR activity. Thus our findings reveal a novel mechanism by which inhibition of GSK-3β promotes lysosome-dependent degradation of c-FLIPL. Our study shows that GSK-3β may become a promising therapeutic target for HCC.
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Affiliation(s)
- Na Zhang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050, China
| | - Xiaojia Liu
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050, China
| | - Lu Liu
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050, China
| | - Zhesong Deng
- Medical College, Nanchang University, Nanchang, Jiangxi, 330006, China
| | - Qingxuan Zeng
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050, China
| | - Weiqiang Pang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050, China
| | - Yang Liu
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050, China
| | - Danqing Song
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050, China.
| | - Hongbin Deng
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050, China.
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562
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Hipolito VEB, Ospina-Escobar E, Botelho RJ. Lysosome remodelling and adaptation during phagocyte activation. Cell Microbiol 2018; 20. [PMID: 29349904 DOI: 10.1111/cmi.12824] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/11/2018] [Accepted: 01/15/2018] [Indexed: 12/30/2022]
Abstract
Lysosomes are acidic and hydrolytic organelles responsible for receiving and digesting cargo acquired during endocytosis, phagocytosis, and autophagy. For macrophages and dendritic cells, the lysosome is kingpin, playing a direct role in microbe killing and antigen processing for presentation. Strikingly, the historic view that lysosomes are homogeneous and static organelles is being replaced with a more elegant paradigm, in which lysosomes are heterogeneous, dynamic, and respond to cellular needs. For example, lysosomes are signalling platforms that integrate stress detection and molecular decision hubs such as the mTOR complex 1 and AMPK to modulate cellular activity. These signals can even adjust lysosome activity by modulating transcription factors such as transcription factor EB (TFEB) and TFE3 that govern lysosome gene expression. Here, we review lysosome remodelling and adaptation during macrophage and dendritic cell stimulation. First, we assess the functional outcomes and regulatory mechanisms driving the dramatic restructuring of lysosomes from globular organelles into a tubular network during phagocyte activation. Second, we discuss lysosome adaptation and scaling in macrophages driven by TFEB and TFE3 stimulation in response to phagocytosis and microbe challenges. Collectively, we are beginning to appreciate that lysosomes are dynamic and adapt to serve phagocyte differentiation in response to microbes and immune stress.
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Affiliation(s)
- Victoria E B Hipolito
- Department of Chemistry and Biology and the Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Erika Ospina-Escobar
- Department of Chemistry and Biology and the Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Roberto J Botelho
- Department of Chemistry and Biology and the Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
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563
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Arsov Z, Urbančič I, Štrancar J. Aggregation-induced emission spectral shift as a measure of local concentration of a pH-activatable rhodamine-based smart probe. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 190:486-493. [PMID: 28965064 DOI: 10.1016/j.saa.2017.09.067] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 09/22/2017] [Accepted: 09/23/2017] [Indexed: 06/07/2023]
Abstract
Generating activatable probes that report about molecular vicinity through contact-based mechanisms such as aggregation can be very convenient. Specifically, such probes change a particular spectral property only at the intended biologically relevant target. Xanthene derivatives, for example rhodamines, are able to form aggregates. It is typical to examine aggregation by absorption spectroscopy but for microscopy applications utilizing fluorescent probes it is very important to perform characterization by measuring fluorescence spectra. First we show that excitation spectra of aqueous solutions of rhodamine 6G can be very informative about the aggregation features. Next we establish the dependence of the fluorescence emission spectral maximum shift on the dimer concentration. The obtained information helped us confirm the possibility of aggregation of a recently designed and synthesized rhodamine 6G-based pH-activatable fluorescent probe and to study its pH and concentration dependence. The size of the aggregation-induced emission spectral shift at specific position on the sample can be measured by fluorescence microspectroscopy, which at particular pH allows estimation of the local concentration of the observed probe at microscopic level. Therefore, we show that besides aggregation-caused quenching and aggregation-induced emission also aggregation-induced emission spectral shift can be a useful photophysical phenomenon.
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Affiliation(s)
- Zoran Arsov
- Laboratory of Biophysics, Department of Condensed Matter Physics, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia; Center of Excellence NAMASTE, Jamova 39, 1000 Ljubljana, Slovenia.
| | - Iztok Urbančič
- Laboratory of Biophysics, Department of Condensed Matter Physics, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
| | - Janez Štrancar
- Laboratory of Biophysics, Department of Condensed Matter Physics, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia; Center of Excellence NAMASTE, Jamova 39, 1000 Ljubljana, Slovenia
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564
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Yuan S, Li H, Dang Y, Liu C. Effects of triphenyl phosphate on growth, reproduction and transcription of genes of Daphnia magna. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 195:58-66. [PMID: 29287174 DOI: 10.1016/j.aquatox.2017.12.009] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 12/20/2017] [Indexed: 06/07/2023]
Abstract
The additive flame retardant triphenyl phosphate (TPHP) has been frequently detected in environments and biota. Evidences indicate that TPHP has potential risks to aquatic organisms. Seldom has been reported about its chronic effects to aquatic organism at low trophic levels, such as Cladocera. In the present study, <12 h old Daphnia magna (D. magna) were exposed to 0, 5, 50 or 500 μg/L TPHP for 21 days to investigate the chronic effects of TPHP on body length, fecundity and survival. Meanwhile, D. magna PCR arrays were used to evaluate the transcriptional responses of 155 genes involved in 40 pathways. Exposure to 500 μg/L TPHP for 21 days significantly decreased the body lengths of both F0 and F1 generation and inhibited the fecundity of F0 generation. Results of RT-qPCR showed that the expressions of 76 genes involved in 15 pathways were significantly altered after exposure to 500 μg/L TPHP for 21 days. The significantly altered pathways related to genetic information processing, cellular process and metabolism might be responsible for the observed effects of TPHP. Overall, our results showed that chronic exposure to TPHP caused developmental and reproductive toxicities to D. magna.
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Affiliation(s)
- Siliang Yuan
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Han Li
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Yao Dang
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Chunsheng Liu
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; Collaborative Innovation Centre for Efficient and Health Production of Fisheries in Hunan Province, Changde 415000, China.
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565
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Gómez NM, Lu W, Lim JC, Kiselyov K, Campagno KE, Grishchuk Y, Slaugenhaupt SA, Pfeffer BA, Fliesler SJ, Mitchell CH. Robust lysosomal calcium signaling through channel TRPML1 is impaired by lysosomal lipid accumulation. FASEB J 2018; 32:782-794. [PMID: 29030399 PMCID: PMC5888396 DOI: 10.1096/fj.201700220rr] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 09/26/2017] [Indexed: 12/20/2022]
Abstract
The transient receptor potential cation channel mucolipin 1 (TRPML1) channel is a conduit for lysosomal calcium efflux, and channel activity may be affected by lysosomal contents. The lysosomes of retinal pigmented epithelial (RPE) cells are particularly susceptible to build-up of lysosomal waste products because they must degrade the outer segments phagocytosed daily from adjacent photoreceptors; incomplete degradation leads to accumulation of lipid waste in lysosomes. This study asks whether stimulation of TRPML1 can release lysosomal calcium in RPE cells and whether such release is affected by lysosomal accumulations. The TRPML agonist ML-SA1 raised cytoplasmic calcium levels in mouse RPE cells, hesRPE cells, and ARPE-19 cells; this increase was rapid, robust, reversible, and reproducible. The increase was not altered by extracellular calcium removal or by thapsigargin but was eliminated by lysosomal rupture with glycyl-l-phenylalanine-β-naphthylamide. Treatment with desipramine to inhibit acid sphingomyelinase or YM201636 to inhibit PIKfyve also reduced the cytoplasmic calcium increase triggered by ML-SA1, whereas RPE cells from TRPML1-/- mice showed no response to ML-SA1. Cotreatment with chloroquine and U18666A induced formation of neutral, autofluorescent lipid in RPE lysosomes and decreased lysosomal Ca2+ release. Lysosomal Ca2+ release was also impaired in RPE cells from the ATP-binding cassette, subfamily A, member 4-/- mouse model of Stargardt's retinal dystrophy. Neither TRPML1 mRNA nor total lysosomal calcium levels were altered in these models, suggesting a more direct effect on the channel. In summary, stimulation of TRPML1 elevates cytoplasmic calcium levels in RPE cells, but this response is reduced by lysosomal accumulation.-Gómez, N. M., Lu, W. Lim, J. C., Kiselyov, K., Campagno, K. E., Grishchuk, Y., Slaugenhaupt, S. A., Pfeffer, B., Fliesler, S. J., Mitchell, C. H. Robust lysosomal calcium signaling through channel TRPML1 is impaired by lysosomal lipid accumulation.
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Affiliation(s)
- Néstor Más Gómez
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Wennan Lu
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jason C. Lim
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kirill Kiselyov
- Department of Biological Science, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Keith E. Campagno
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Yulia Grishchuk
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, Massachusetts, USA
- Department of Neurology, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Susan A. Slaugenhaupt
- Center for Genomic Medicine, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, Massachusetts, USA
- Department of Neurology, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Bruce A. Pfeffer
- Department of Ophthalmology, Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, State University of New York (SUNY)–University at Buffalo, Buffalo, New York, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York (SUNY)–University at Buffalo, Buffalo, New York, USA
- State University of New York (SUNY)–Eye Institute, Buffalo, New York, USA
- Research Service, Veterans Affairs Western New York Healthcare System, Buffalo, New York, USA
| | - Steven J. Fliesler
- Department of Ophthalmology, Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, State University of New York (SUNY)–University at Buffalo, Buffalo, New York, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York (SUNY)–University at Buffalo, Buffalo, New York, USA
- State University of New York (SUNY)–Eye Institute, Buffalo, New York, USA
- Research Service, Veterans Affairs Western New York Healthcare System, Buffalo, New York, USA
| | - Claire H. Mitchell
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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566
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Uddin MS, Stachowiak A, Mamun AA, Tzvetkov NT, Takeda S, Atanasov AG, Bergantin LB, Abdel-Daim MM, Stankiewicz AM. Autophagy and Alzheimer's Disease: From Molecular Mechanisms to Therapeutic Implications. Front Aging Neurosci 2018; 10:04. [PMID: 29441009 PMCID: PMC5797541 DOI: 10.3389/fnagi.2018.00004] [Citation(s) in RCA: 256] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 01/08/2018] [Indexed: 01/07/2023] Open
Abstract
Alzheimer’s disease (AD) is the most common cause of progressive dementia in the elderly. It is characterized by a progressive and irreversible loss of cognitive abilities and formation of senile plaques, composed mainly of amyloid β (Aβ), and neurofibrillary tangles (NFTs), composed of tau protein, in the hippocampus and cortex of afflicted humans. In brains of AD patients the metabolism of Aβ is dysregulated, which leads to the accumulation and aggregation of Aβ. Metabolism of Aβ and tau proteins is crucially influenced by autophagy. Autophagy is a lysosome-dependent, homeostatic process, in which organelles and proteins are degraded and recycled into energy. Thus, dysfunction of autophagy is suggested to lead to the accretion of noxious proteins in the AD brain. In the present review, we describe the process of autophagy and its importance in AD. Additionally, we discuss mechanisms and genes linking autophagy and AD, i.e., the mTOR pathway, neuroinflammation, endocannabinoid system, ATG7, BCL2, BECN1, CDK5, CLU, CTSD, FOXO1, GFAP, ITPR1, MAPT, PSEN1, SNCA, UBQLN1, and UCHL1. We also present pharmacological agents acting via modulation of autophagy that may show promise in AD therapy. This review updates our knowledge on autophagy mechanisms proposing novel therapeutic targets for the treatment of AD.
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Affiliation(s)
- Md Sahab Uddin
- Department of Pharmacy, Southeast University, Dhaka, Bangladesh
| | - Anna Stachowiak
- Department of Experimental Embryology, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, Magdalenka, Poland
| | | | - Nikolay T Tzvetkov
- Department of Molecular Biology and Biochemical Pharmacology, Institute of Molecular Biology "Roumen Tsanev", Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Shinya Takeda
- Department of Clinical Psychology, Tottori University Graduate School of Medical Sciences, Tottori, Japan
| | - Atanas G Atanasov
- Department of Molecular Biology, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, Magdalenka, Poland.,Department of Pharmacognosy, University of Vienna, Vienna, Austria
| | - Leandro B Bergantin
- Department of Pharmacology, Federal University of São Paulo, São Paulo, Brazil
| | - Mohamed M Abdel-Daim
- Department of Pharmacology, Suez Canal University, Ismailia, Egypt.,Department of Ophthalmology and Micro-technology, Yokohama City University, Yokohama, Japan
| | - Adrian M Stankiewicz
- Department of Molecular Biology, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, Magdalenka, Poland
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567
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Kosicek M, Gudelj I, Horvatic A, Jovic T, Vuckovic F, Lauc G, Hecimovic S. N-glycome of the Lysosomal Glycocalyx is Altered in Niemann-Pick Type C Disease (NPC) Model Cells. Mol Cell Proteomics 2018; 17:631-642. [PMID: 29367433 DOI: 10.1074/mcp.ra117.000129] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 12/18/2017] [Indexed: 12/17/2022] Open
Abstract
Increasing evidence implicates lysosomal dysfunction in the pathogenesis of neurodegenerative diseases, including the rare inherited lysosomal storage disorders (LSDs) and the most common neurodegenerative diseases, such as Alzheimer's and Parkinson's disease (AD and PD). Although the triggers of the lysosomal impairment may involve the accumulated macromolecules or dysfunction of the lysosomal enzymes, the role of the lysosomal glycocalyx in the lysosomal (dys)function has not been studied. The goal of this work was to analyze whether there are changes in the lysosomal glycocalyx in a cellular model of a LSD Niemann-Pick type C disease (NPC). Using the ferrofluid nanoparticles we isolated lysosomal organelles from NPC1-null and CHOwt cells. The magnetically isolated lysosomal fractions were enriched with the lysosomal marker protein LAMP1 and showed the key features of NPC disease: 3-fold higher cholesterol content and 4-5 fold enlarged size of the particles compared with the lysosomal fractions of wt cells. These lysosomal fractions were further processed to isolate lysosomal membrane proteins using Triton X-114 and their N-glycome was analyzed by HILIC-UPLC. N-glycans presented in each chromatographic peak were elucidated using MALDI-TOF/TOF-MS. We detected changes in the N-glycosylation pattern of the lysosomal glycocalyx of NPC1-null versus wt cells which involved high-mannose and sialylated N-glycans. To the best of our knowledge this study is the first to report N-glycome profiling of the lysosomal glycocalyx in NPC disease cellular model and the first to report the specific changes in the lysosomal glycocalyx in NPC1-null cells. We speculate that changes in the lysosomal glycocalyx may contribute to lysosomal (dys)function. Further glycome profiling of the lysosomal glycocalyx in other LSDs as well as the most common neurodegenerative diseases, such as AD and PD, is necessary to better understand the role of the lysosomal glycocalyx and to reveal its potential contribution in lysosomal dysfunction leading to neurodegeneration.
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Affiliation(s)
- Marko Kosicek
- From the ‡Laboratory for Neurodegenerative Disease Research, Division of Molecular Medicine, Ruđer Bošković Institute, Zagreb, Croatia
| | - Ivan Gudelj
- §Genos Glycoscience Research Laboratory, Zagreb, Croatia
| | - Anita Horvatic
- ¶ERA Chair team, Internal Diseases Clinic, University of Zagreb, Faculty of Veterinary Medicine, Heinzelova 55, 10000 Zagreb, Croatia
| | - Tanja Jovic
- From the ‡Laboratory for Neurodegenerative Disease Research, Division of Molecular Medicine, Ruđer Bošković Institute, Zagreb, Croatia.,‖University of Zagreb Faculty of Pharmacy and Biochemistry, Zagreb, Croatia
| | - Frano Vuckovic
- §Genos Glycoscience Research Laboratory, Zagreb, Croatia
| | - Gordan Lauc
- §Genos Glycoscience Research Laboratory, Zagreb, Croatia.,‖University of Zagreb Faculty of Pharmacy and Biochemistry, Zagreb, Croatia
| | - Silva Hecimovic
- From the ‡Laboratory for Neurodegenerative Disease Research, Division of Molecular Medicine, Ruđer Bošković Institute, Zagreb, Croatia;
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568
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Chávez JC, De la Vega-Beltrán JL, José O, Torres P, Nishigaki T, Treviño CL, Darszon A. Acrosomal alkalization triggers Ca 2+ release and acrosome reaction in mammalian spermatozoa. J Cell Physiol 2018; 233:4735-4747. [PMID: 29135027 DOI: 10.1002/jcp.26262] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 10/12/2017] [Indexed: 01/01/2023]
Abstract
The sperm acrosome reaction (AR), an essential event for mammalian fertilization, involves Ca2+ permeability changes leading to exocytosis of the acrosomal vesicle. The acrosome, an intracellular Ca2+ store whose luminal pH is acidic, contains hydrolytic enzymes. It is known that acrosomal pH (pHacr ) increases during capacitation and this correlates with spontaneous AR. Some AR inducers increase intracellular Ca2+ concentration ([Ca2+ ]i ) through Ca2+ release from internal stores, mainly the acrosome. Catsper, a sperm specific Ca2+ channel, has been suggested to participate in the AR. Curiously, Mibefradil and NNC55-0396, two CatSper blockers, themselves elevate [Ca2+ ]i by unknown mechanisms. Here we show that these compounds, as other weak bases, can elevate pHacr , trigger Ca2+ release from the acrosome, and induce the AR in both mouse and human sperm. To our surprise, μM concentrations of NNC55-0396 induced AR even in nominally Ca2+ free media. Our findings suggest that alkalization of the acrosome is critical step for Ca2+ release from the acrosome that leads to the acrosome reaction.
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Affiliation(s)
- Julio C Chávez
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, CP, México
| | - José L De la Vega-Beltrán
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, CP, México
| | - Omar José
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, CP, México
| | - Paulina Torres
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, CP, México
| | - Takuya Nishigaki
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, CP, México
| | - Claudia L Treviño
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, CP, México
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, CP, México
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569
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Patel S. Ins and outs of Ca 2+ transport by acidic organelles and cell migration. Commun Integr Biol 2018. [PMCID: PMC5824967 DOI: 10.1080/19420889.2017.1331800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Much contemporary evidence underscores the pathophysiological importance of Ca2+ handling by acidic organelles such as lysosomes. Whereas our knowledge of how Ca2+ is released from these acidic Ca2+ stores (the ‘outs’) is advancing, we know relatively little about how Ca2+ uptake is effected (the ‘ins’). Here I highlight new work identifying animal Ca2+/H+ (CAX) exchangers that localize to acidic organelles, mediate Ca2+ uptake and regulate cell migration in vivo. Continued molecular definition of the acidic Ca2+ store toolkit provides new insight into Ca2+-dependent function.
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Affiliation(s)
- Sandip Patel
- Department of Cell and Developmental Biology, University College London, London, UK
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570
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Nieto C, Vega MA, Marcelo G, Martín del Valle E. Polydopamine nanoparticles kill cancer cells. RSC Adv 2018; 8:36201-36208. [PMID: 35558470 PMCID: PMC9088449 DOI: 10.1039/c8ra05586f] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/08/2018] [Indexed: 12/22/2022] Open
Abstract
Polydopamine (PD) is a synthetic melanin analogue of growing importance in the field of biomedicine, especially with respect to cancer research, due, in part, to its biocompatibility.
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Affiliation(s)
- Celia Nieto
- Department of Chemical Engineering
- Universidad de Salamanca
- Salamanca
- Spain
| | - Milena A. Vega
- Department of Chemical Engineering
- Universidad de Salamanca
- Salamanca
- Spain
| | - Gema Marcelo
- Department of Chemical Engineering
- Universidad de Salamanca
- Salamanca
- Spain
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571
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Srivastava P, Srivastava P, Patra AK. Biological perspectives of a FRET based pH-probe exhibiting molecular logic gate operation with altering pH. NEW J CHEM 2018. [DOI: 10.1039/c8nj01318g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A FRET probe for applications in pH sensing, CT-DNA/BSA interactions and logic gate/circuit construction with H+/OH−ions.
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Affiliation(s)
- Priyanka Srivastava
- Department of Chemistry
- Indian Institute of Technology Kanpur
- Kanpur 208016
- India
| | - Payal Srivastava
- Department of Chemistry
- Indian Institute of Technology Kanpur
- Kanpur 208016
- India
| | - Ashis K. Patra
- Department of Chemistry
- Indian Institute of Technology Kanpur
- Kanpur 208016
- India
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572
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Trybus W, Król G, Trybus E, Stachurska A, Kopacz- Bednarska A, Król T. Aloe-Emodin Influence on the Lysosomal Compartment of Hela Cells. Asian Pac J Cancer Prev 2017; 18:3273-3279. [PMID: 29286219 PMCID: PMC5980883 DOI: 10.22034/apjcp.2017.18.12.3273] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Background: Aloe-emodin belongs to the group of anthraquinones having extremely high biological activity. The aim of this study was to evaluate the range of morphological and biochemical changes in HeLa cells treated with aloe-emodin, especially with regard to the lysosomal compartment. Methods: Marking of lysosomes was performed with neutral red staining for conventional light microscopy and acridine orange staining for confocal microscopy. To evaluate ctivity of lysosomal enzymes and permeability of the lysosomal membrane, spectrophotometric techniques were employed. Results: Aloe-emodin caused increased permeability of lysosomal membranes in HeLa cells, expressed inter alia by extinction of the orange color of acridine orange (lysosomal marker) and in reduction of neutral red uptake by lysosomes. These changes are accompanied by release of cathepsins from the interior of the lysosomes with a simultaneous highly significant increase in their activity in the cytoplasm. Conclusion: The results indicate that aloeemodin can activate lysosomal pathway-dependent apoptosis in HeLa cells.
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Affiliation(s)
- Wojciech Trybus
- Department of Cell Biology and Electron Microscopy, Institute of Biology, The Jan Kochanowski University, Świętokrzyska 15, 25-406 Kielce, Poland.
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573
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Kroemer G, Galluzzi L. Lysosome-targeting agents in cancer therapy. Oncotarget 2017; 8:112168-112169. [PMID: 29348815 PMCID: PMC5762500 DOI: 10.18632/oncotarget.21451] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 09/16/2017] [Indexed: 12/22/2022] Open
Abstract
Despite considerable efforts from multiple laboratories worldwide, highly specific inhibitors of autophagy for clinical use are not yet available. Lysosomal inhibitors are being employed instead, in spite of multiple limitations that are summarized herein.
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Affiliation(s)
- Guido Kroemer
- Université Paris Descartes/Paris V, Paris, France
- Université Pierre et Marie Curie/Paris VI, Paris, France
- Equipe 11 labellisée Ligue contre le Cancer, Centre de Recherche des Cordeliers, Paris, France
- INSERM, U1138, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy Comprehensive Cancer Institute, Villejuif, France
- Department of Women’s and Children’s Health, Karolinska Institute, Karolinska University Hospital, Stockholm, Sweden
- Pôle de Biologie, Hopitâl Européen George Pompidou, AP-HP, Paris, France
| | - Lorenzo Galluzzi
- Université Paris Descartes/Paris V, Paris, France
- Department of Radiation Oncology, Weill Cornell Medical College, New York, NY, USA
- Sandra and Edward Meyer Cancer Center, New York, NY, USA
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574
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Dysregulation of autophagy as a common mechanism in lysosomal storage diseases. Essays Biochem 2017; 61:733-749. [PMID: 29233882 PMCID: PMC5869865 DOI: 10.1042/ebc20170055] [Citation(s) in RCA: 126] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Revised: 10/08/2017] [Accepted: 10/12/2017] [Indexed: 12/19/2022]
Abstract
The lysosome plays a pivotal role between catabolic and anabolic processes as the nexus for signalling pathways responsive to a variety of factors, such as growth, nutrient availability, energetic status and cellular stressors. Lysosomes are also the terminal degradative organelles for autophagy through which macromolecules and damaged cellular components and organelles are degraded. Autophagy acts as a cellular homeostatic pathway that is essential for organismal physiology. Decline in autophagy during ageing or in many diseases, including late-onset forms of neurodegeneration is considered a major contributing factor to the pathology. Multiple lines of evidence indicate that impairment in autophagy is also a central mechanism underlying several lysosomal storage disorders (LSDs). LSDs are a class of rare, inherited disorders whose histopathological hallmark is the accumulation of undegraded materials in the lysosomes due to abnormal lysosomal function. Inefficient degradative capability of the lysosomes has negative impact on the flux through the autophagic pathway, and therefore dysregulated autophagy in LSDs is emerging as a relevant disease mechanism. Pathology in the LSDs is generally early-onset, severe and life-limiting but current therapies are limited or absent; recognizing common autophagy defects in the LSDs raises new possibilities for therapy. In this review, we describe the mechanisms by which LSDs occur, focusing on perturbations in the autophagy pathway and present the latest data supporting the development of novel therapeutic approaches related to the modulation of autophagy.
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575
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Todkar K, Ilamathi HS, Germain M. Mitochondria and Lysosomes: Discovering Bonds. Front Cell Dev Biol 2017; 5:106. [PMID: 29270406 PMCID: PMC5725469 DOI: 10.3389/fcell.2017.00106] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 11/22/2017] [Indexed: 01/30/2023] Open
Abstract
In the last decade, the traditional view of lysosomes has been challenged by the recognition that lysosomes are not only degradative organelles, but also metabolic sensors that play a key role in the regulation of metabolism and cell growth. Similarly, mitochondria are now seen as crucial metabolic hubs dictating cell fate decisions, not just ATP-producing machines. Importantly, these functions are generally performed as a coordinate response of distinct organelles that are physically and functionally connected. While the association between mitochondria and the endoplasmic reticulum is well known, a similar interaction between mitochondria and lysosomes is now emerging. This interaction could be required to shuttle amino acids, lipids and ions such as Ca2+ between the two organelles, thereby modulating their metabolic functions. In addition, a tethering complex linking the two organelles has recently been described in yeast, although the mammalian counterpart has yet to be identified. Here, we discuss the implications of these recent findings.
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Affiliation(s)
- Kiran Todkar
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.,Centre de Recherche Biomed, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Hema S Ilamathi
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.,Centre de Recherche Biomed, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Marc Germain
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada.,Centre de Recherche Biomed, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
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576
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Zhou X, Li M, Su D, Jia Q, Li H, Li X, Yang J. Cryo-EM structures of the human endolysosomal TRPML3 channel in three distinct states. Nat Struct Mol Biol 2017; 24:1146-1154. [PMID: 29106414 PMCID: PMC5747366 DOI: 10.1038/nsmb.3502] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 10/10/2017] [Indexed: 12/23/2022]
Abstract
TRPML3 channels are mainly localized to endolysosomes and play a critical role in the endocytic pathway. Their dysfunction causes deafness and pigmentation defects in mice. TRPML3 activity is inhibited by low endolysosomal pH. Here we present cryo-electron microscopy (cryo-EM) structures of human TRPML3 in the closed, agonist-activated, and low-pH-inhibited states, with resolutions of 4.06, 3.62, and 4.65 Å, respectively. The agonist ML-SA1 lodges between S5 and S6 and opens an S6 gate. A polycystin-mucolipin domain (PMD) forms a luminal cap. S1 extends into this cap, forming a 'gating rod' that connects directly to a luminal pore loop, which undergoes dramatic conformational changes in response to low pH. S2 extends intracellularly and interacts with several intracellular regions to form a 'gating knob'. These unique structural features, combined with the results of electrophysiological studies, indicate a new mechanism by which luminal pH and other physiological modulators such as PIP2 regulate TRPML3 by changing S1 and S2 conformations.
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Affiliation(s)
- Xiaoyuan Zhou
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Minghui Li
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Deyuan Su
- Department of Biological Sciences, Columbia University, New York, NY, USA
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, and Ion Channel Research and Drug Development Center, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Qi Jia
- Department of Orthopedic Oncology, Shanghai Changzheng Hospital, The Second Military Medical University, Shanghai 200003, China
| | - Huan Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, and Ion Channel Research and Drug Development Center, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China
| | - Xueming Li
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jian Yang
- Department of Biological Sciences, Columbia University, New York, NY, USA
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, and Ion Channel Research and Drug Development Center, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
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577
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Park HH, Woo YH, Ryu J, Lee HJ, Park JH, Park TH. Enzyme delivery using protein-stabilizing and cell-penetrating 30Kc19α protein nanoparticles. Process Biochem 2017. [DOI: 10.1016/j.procbio.2017.08.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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578
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Jena P, Roxbury D, Galassi TV, Akkari L, Horoszko CP, Iaea DB, Budhathoki-Uprety J, Pipalia N, Haka AS, Harvey JD, Mittal J, Maxfield FR, Joyce JA, Heller DA. A Carbon Nanotube Optical Reporter Maps Endolysosomal Lipid Flux. ACS NANO 2017; 11:10689-10703. [PMID: 28898055 PMCID: PMC5707631 DOI: 10.1021/acsnano.7b04743] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 08/31/2017] [Indexed: 05/18/2023]
Abstract
Lipid accumulation within the lumen of endolysosomal vesicles is observed in various pathologies including atherosclerosis, liver disease, neurological disorders, lysosomal storage disorders, and cancer. Current methods cannot measure lipid flux specifically within the lysosomal lumen of live cells. We developed an optical reporter, composed of a photoluminescent carbon nanotube of a single chirality, that responds to lipid accumulation via modulation of the nanotube's optical band gap. The engineered nanomaterial, composed of short, single-stranded DNA and a single nanotube chirality, localizes exclusively to the lumen of endolysosomal organelles without adversely affecting cell viability or proliferation or organelle morphology, integrity, or function. The emission wavelength of the reporter can be spatially resolved from within the endolysosomal lumen to generate quantitative maps of lipid content in live cells. Endolysosomal lipid accumulation in cell lines, an example of drug-induced phospholipidosis, was observed for multiple drugs in macrophages, and measurements of patient-derived Niemann-Pick type C fibroblasts identified lipid accumulation and phenotypic reversal of this lysosomal storage disease. Single-cell measurements using the reporter discerned subcellular differences in equilibrium lipid content, illuminating significant intracellular heterogeneity among endolysosomal organelles of differentiating bone-marrow-derived monocytes. Single-cell kinetics of lipoprotein-derived cholesterol accumulation within macrophages revealed rates that differed among cells by an order of magnitude. This carbon nanotube optical reporter of endolysosomal lipid content in live cells confers additional capabilities for drug development processes and the investigation of lipid-linked diseases.
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Affiliation(s)
- Prakrit
V. Jena
- Memorial
Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Daniel Roxbury
- Department
of Chemical Engineering, University of Rhode
Island, Kingston, Rhode Island 02881, United States
| | - Thomas V. Galassi
- Memorial
Sloan Kettering Cancer Center, New York, New York 10065, United States
- Weill
Cornell Medicine, New York, New York 10065, United States
| | - Leila Akkari
- Memorial
Sloan Kettering Cancer Center, New York, New York 10065, United States
- Division
of Tumor Biology & Immunology, The Netherlands
Cancer Institute, Amsterdam 1066 CX, The Netherlands
| | - Christopher P. Horoszko
- Memorial
Sloan Kettering Cancer Center, New York, New York 10065, United States
- Weill
Cornell Medicine, New York, New York 10065, United States
| | - David B. Iaea
- Weill
Cornell Medicine, New York, New York 10065, United States
| | | | - Nina Pipalia
- Weill
Cornell Medicine, New York, New York 10065, United States
| | - Abigail S. Haka
- Weill
Cornell Medicine, New York, New York 10065, United States
| | - Jackson D. Harvey
- Memorial
Sloan Kettering Cancer Center, New York, New York 10065, United States
- Weill
Cornell Medicine, New York, New York 10065, United States
| | - Jeetain Mittal
- Department
of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | | | - Johanna A. Joyce
- Memorial
Sloan Kettering Cancer Center, New York, New York 10065, United States
- Weill
Cornell Medicine, New York, New York 10065, United States
- Ludwig Center
for Cancer Research, University of Lausanne, Lausanne CH 1066, Switzerland
| | - Daniel A. Heller
- Memorial
Sloan Kettering Cancer Center, New York, New York 10065, United States
- Weill
Cornell Medicine, New York, New York 10065, United States
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579
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Xiao S, Li R, El Zowalaty AE, Diao H, Zhao F, Choi Y, Ye X. Acidification of uterine epithelium during embryo implantation in mice. Biol Reprod 2017; 96:232-243. [PMID: 28395338 DOI: 10.1095/biolreprod.116.144451] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Accepted: 11/22/2016] [Indexed: 12/31/2022] Open
Abstract
Uterine luminal epithelium (LE) is essential for establishing uterine receptivity. Previous microarray analysis revealed upregulation of Atp6v0d2 in gestation day 4.5 (D4.5) LE in mice. Realtime PCR showed upregulation of uterine Atp6v0d2 starting right before embryo attachment ∼D4.0. In situ hybridization demonstrated specific uterine localization of Atp6v0d2 in LE upon embryo implantation. Atp6v0d2 encodes one subunit for vacuolar-type H+-ATPase (V-ATPase), which regulates acidity of intracellular organelles and extracellular environment. LysoSensor Green DND-189 detected acidic signals in LE and glandular epithelium upon embryo implantation, correlating with Atp6v0d2 upregulation in early pregnant uterus. Atp6v0d2-/- females had significantly reduced implantation rate and marginally reduced delivery rate from first mating only, but comparable number of implantation sites and litter size compared to control and comparable fertility to control from subsequent matings, suggesting a nonessential role of Atp6v0d2 subunit in embryo implantation. Successful implantation in both control and Atp6v0d2-/- females was associated with uterine epithelial acidification. No significant compensatory upregulation of Atp6v0d1 mRNA was detected in D4.5 Atp6v0d2-/- uteri. To determine the role of V-ATPase instead of a single subunit in embryo implantation, a specific V-ATPase inhibitor bafilomycin A1 (2.5 μg/kg) was injected via uterine fat pad on D3 18:00 h. This treatment resulted in reduced uterine epithelial acidification, delayed implantation, and reduced number of implantation sites. It also suppressed oil-induced artificial decidualization. These data demonstrate uterine epithelial acidification as a novel phenomenon during embryo implantation and V-ATPase is involved in uterine epithelial acidification and uterine preparation for embryo implantation.
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Affiliation(s)
- Shuo Xiao
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.,Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA
| | - Rong Li
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.,Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA
| | - Ahmed E El Zowalaty
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.,Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA
| | - Honglu Diao
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.,Reproductive Medical Center, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei 442000, China
| | - Fei Zhao
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.,Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA
| | - Yongwon Choi
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Xiaoqin Ye
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.,Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA
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580
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Kondratskyi A, Kondratska K, Skryma R, Klionsky DJ, Prevarskaya N. Ion channels in the regulation of autophagy. Autophagy 2017; 14:3-21. [PMID: 28980859 PMCID: PMC5846505 DOI: 10.1080/15548627.2017.1384887] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 09/07/2017] [Accepted: 09/21/2017] [Indexed: 12/18/2022] Open
Abstract
Autophagy is a cellular process in which the cell degrades and recycles its own constituents. Given the crucial role of autophagy in physiology, deregulation of autophagic machinery is associated with various diseases. Hence, a thorough understanding of autophagy regulatory mechanisms is crucially important for the elaboration of efficient treatments for different diseases. Recently, ion channels, mediating ion fluxes across cellular membranes, have emerged as important regulators of both basal and induced autophagy. However, the mechanisms by which specific ion channels regulate autophagy are still poorly understood, thus underscoring the need for further research in this field. Here we discuss the involvement of major types of ion channels in autophagy regulation.
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Affiliation(s)
- Artem Kondratskyi
- Inserm, U-1003, Laboratory of Excellence, Ion Channels Science and Therapeutics, University of Lille 1, Villeneuve d'Ascq, France
| | - Kateryna Kondratska
- Inserm, U-1003, Laboratory of Excellence, Ion Channels Science and Therapeutics, University of Lille 1, Villeneuve d'Ascq, France
| | - Roman Skryma
- Inserm, U-1003, Laboratory of Excellence, Ion Channels Science and Therapeutics, University of Lille 1, Villeneuve d'Ascq, France
| | - Daniel J. Klionsky
- Life Sciences Institute, and Department of Molecular, Cellular and Developmental Biology; University of Michigan, Ann Arbor, MI, USA
| | - Natalia Prevarskaya
- Inserm, U-1003, Laboratory of Excellence, Ion Channels Science and Therapeutics, University of Lille 1, Villeneuve d'Ascq, France
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581
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Rahman N, Ramos-Espiritu L, Milner TA, Buck J, Levin LR. Soluble adenylyl cyclase is essential for proper lysosomal acidification. J Gen Physiol 2017; 148:325-39. [PMID: 27670898 PMCID: PMC5037342 DOI: 10.1085/jgp.201611606] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 09/08/2016] [Indexed: 01/07/2023] Open
Abstract
Lysosomes, the degradative organelles of the endocytic and autophagic pathways, function at an acidic pH. Lysosomes are acidified by the proton-pumping vacuolar ATPase (V-ATPase), but the molecular processes that set the organelle's pH are not completely understood. In particular, pH-sensitive signaling enzymes that can regulate lysosomal acidification in steady-state physiological conditions have yet to be identified. Soluble adenylyl cyclase (sAC) is a widely expressed source of cAMP that serves as a physiological pH sensor in cells. For example, in proton-secreting epithelial cells, sAC is responsible for pH-dependent translocation of V-ATPase to the luminal surface. Here we show genetically and pharmacologically that sAC is also essential for lysosomal acidification. In the absence of sAC, V-ATPase does not properly localize to lysosomes, lysosomes fail to fully acidify, lysosomal degradative capacity is diminished, and autophagolysosomes accumulate.
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Affiliation(s)
- Nawreen Rahman
- Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065 Graduate Program in Neuroscience, Weill Cornell Medical College, New York, NY 10065
| | | | - Teresa A Milner
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065 Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY 10065
| | - Jochen Buck
- Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065
| | - Lonny R Levin
- Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065
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582
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Wang L, Wang K. Highlights for the 6th International Ion Channel Conference: ion channel structure, function, disease and therapeutics. Acta Pharm Sin B 2017; 7:665-669. [PMID: 29159026 PMCID: PMC5687311 DOI: 10.1016/j.apsb.2017.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 08/15/2017] [Indexed: 11/17/2022] Open
Abstract
To foster communication and interactions amongst international scholars and scientists in the field of ion channel research, the 6th International Ion Channel Conference (IICC-2017) was held between June 23–27, 2017 in the eastern coastal city of Qingdao, China. The meeting consisted of 450 attendees and 130 speakers and poster presenters. The program consisted of research progress, new findings and ongoing studies that were focused on (1) Ion channel structure and function; (2) Ion channel physiology and human diseases; (3) Ion channels as targets for drug discovery; (4) Technological advances in ion channel research. An insightful overview was presented on the structure and function of the mechanotransduction channel Drosophila NOMPC (No mechanoreceptor potential C), a member of the transient receptor potential (TRP) channel family. Recent studies on Transmembrane protein 16 or Anoctamin-1 (TMEM16A, a member of the calcium-activated chloride channel [CaCC] family) were summarized as well. In addition, topics for ion channel regulation, homeostatic feedback and brain disorders were thoroughly discussed. The presentations at the IICC-2017 offer new insights into our understanding of ion channel structures and functions, and ion channels as targets for drug discovery.
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583
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Rozenfeld P, Feriozzi S. Contribution of inflammatory pathways to Fabry disease pathogenesis. Mol Genet Metab 2017; 122:19-27. [PMID: 28947349 DOI: 10.1016/j.ymgme.2017.09.004] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 09/11/2017] [Accepted: 09/11/2017] [Indexed: 01/25/2023]
Abstract
Lysosomal storage diseases are usually considered to be pathologies in which the passive deposition of unwanted materials leads to functional changes in lysosomes. Lysosomal deposition of unmetabolized glycolipid substrates stimulates the activation of pathogenic cascades, including immunological processes, and particularly the activation of inflammation. In lysosomal storage diseases, the inflammatory response is continuously being activated because the stimulus cannot be eliminated. Consequently, inflammation becomes a chronic process. Lysosomes play a role in many steps of the immune response. Leukocyte perturbation and over-expression of immune molecules have been reported in Fabry disease. Innate immunity is activated by signals originating from dendritic cells via interactions between toll-like receptors and globotriaosylceramide (Gb3) and/or globotriaosylsphingosine (lyso-Gb3). Evidence indicates that these glycolipids can activate toll-like receptors, thus triggering inflammation and fibrosis cascades. In the kidney, Gb3 deposition is associated with the increased release of transforming growth factor beta and with epithelial-to-mesenchymal cell transition, leading to the over-expression of pro-fibrotic molecules and to renal fibrosis. Interstitial fibrosis is also a typical feature of heart involvement in Fabry disease. Endomyocardial biopsies show infiltration of lymphocytes and macrophages, suggesting a role for inflammation in causing tissue damage. Inflammation is present in all tissues and may be associated with other potentially pathologic processes such as apoptosis, impaired autophagy, and increases in pro-oxidative molecules, which could all contribute synergistically to tissue damage. In Fabry disease, the activation of chronic inflammation over time leads to organ damage. Therefore, enzyme replacement therapy must be started early, before this process becomes irreversible.
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Affiliation(s)
- Paula Rozenfeld
- IIFP (Instituto de Estudios Inmunológicos y Fisiopatológicos) UNLP, CONICET, Facultad de Ciencias Exactas, Buenos Aires, Argentina.
| | - Sandro Feriozzi
- Nephrology and Dialysis Unit, Belcolle Hospital, Viterbo, Italy.
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584
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Naufer A, Hipolito VEB, Ganesan S, Prashar A, Zaremberg V, Botelho RJ, Terebiznik MR. pH of endophagosomes controls association of their membranes with Vps34 and PtdIns(3)P levels. J Cell Biol 2017; 217:329-346. [PMID: 29089378 PMCID: PMC5748975 DOI: 10.1083/jcb.201702179] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 09/03/2017] [Accepted: 09/26/2017] [Indexed: 12/19/2022] Open
Abstract
Specific changes in phospholipid content are a hallmark of the membranes of maturing endosomes and phagosomes, but is it unclear how this is controlled. Naufer et al. now show that acidification of the lumen of endosomes and phagosomes triggers dissociation of the Vps34 lipid kinase from these organelles, which terminates PtdIns(3)P synthesis and signaling. Phagocytosis of filamentous bacteria occurs through tubular phagocytic cups (tPCs) and takes many minutes to engulf these filaments into phagosomes. Contravening the canonical phagocytic pathway, tPCs mature by fusing with endosomes. Using this model, we observed the sequential recruitment of early and late endolysosomal markers to the elongating tPCs. Surprisingly, the regulatory early endosomal lipid phosphatidylinositol-3-phosphate (PtdIns(3)P) persists on tPCs as long as their luminal pH remains neutral. Interestingly, by manipulating cellular pH, we determined that PtdIns(3)P behaves similarly in canonical phagosomes as well as endosomes. We found that this is the product of a pH-based mechanism that induces the dissociation of the Vps34 class III phosphatidylinositol-3-kinase from these organelles as they acidify. The detachment of Vps34 stops the production of PtdIns(3)P, allowing for the turnover of this lipid by PIKfyve. Given that PtdIns(3)P-dependent signaling is important for multiple cellular pathways, this mechanism for pH-dependent regulation of Vps34 could be at the center of many PtdIns(3)P-dependent cellular processes.
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Affiliation(s)
- Amriya Naufer
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Canada.,Department of Cell and System Biology, University of Toronto Scarborough, Toronto, Canada
| | - Victoria E B Hipolito
- Molecular Science Graduate Program, Ryerson University, Toronto, Canada.,Department of Chemistry and Biology, Ryerson University, Toronto, Canada
| | | | - Akriti Prashar
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Canada.,Department of Cell and System Biology, University of Toronto Scarborough, Toronto, Canada
| | - Vanina Zaremberg
- Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - Roberto J Botelho
- Molecular Science Graduate Program, Ryerson University, Toronto, Canada .,Department of Chemistry and Biology, Ryerson University, Toronto, Canada
| | - Mauricio R Terebiznik
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Canada .,Department of Cell and System Biology, University of Toronto Scarborough, Toronto, Canada
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585
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Muallem S, Chung WY, Jha A, Ahuja M. Lipids at membrane contact sites: cell signaling and ion transport. EMBO Rep 2017; 18:1893-1904. [PMID: 29030479 DOI: 10.15252/embr.201744331] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 06/10/2017] [Accepted: 09/21/2017] [Indexed: 12/14/2022] Open
Abstract
Communication between organelles is essential to coordinate cellular functions and the cell's response to physiological and pathological stimuli. Organellar communication occurs at membrane contact sites (MCSs), where the endoplasmic reticulum (ER) membrane is tethered to cellular organelle membranes by specific tether proteins and where lipid transfer proteins and cell signaling proteins are located. MCSs have many cellular functions and are the sites of lipid and ion transfer between organelles and generation of second messengers. This review discusses several aspects of MCSs in the context of lipid transfer, formation of lipid domains, generation of Ca2+ and cAMP second messengers, and regulation of ion transporters by lipids.
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Affiliation(s)
- Shmuel Muallem
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
| | - Woo Young Chung
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
| | - Archana Jha
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
| | - Malini Ahuja
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
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586
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Schmiege P, Fine M, Blobel G, Li X. Human TRPML1 channel structures in open and closed conformations. Nature 2017; 550:366-370. [PMID: 29019983 DOI: 10.1038/nature24036] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Accepted: 08/24/2017] [Indexed: 12/20/2022]
Abstract
Transient receptor potential mucolipin 1 (TRPML1) is a Ca2+-releasing cation channel that mediates the calcium signalling and homeostasis of lysosomes. Mutations in TRPML1 lead to mucolipidosis type IV, a severe lysosomal storage disorder. Here we report two electron cryo-microscopy structures of full-length human TRPML1: a 3.72-Å apo structure at pH 7.0 in the closed state, and a 3.49-Å agonist-bound structure at pH 6.0 in an open state. Several aromatic and hydrophobic residues in pore helix 1, helices S5 and S6, and helix S6 of a neighbouring subunit, form a hydrophobic cavity to house the agonist, suggesting a distinct agonist-binding site from that found in TRPV1, a TRP channel from a different subfamily. The opening of TRPML1 is associated with distinct dilations of its lower gate together with a slight structural movement of pore helix 1. Our work reveals the regulatory mechanism of TRPML channels, facilitates better understanding of TRP channel activation, and provides insights into the molecular basis of mucolipidosis type IV pathogenesis.
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Affiliation(s)
- Philip Schmiege
- Laboratory of Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, New York 10065, USA.,Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Michael Fine
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Günter Blobel
- Laboratory of Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, New York 10065, USA
| | - Xiaochun Li
- Laboratory of Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, New York 10065, USA.,Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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587
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Hirschi M, Herzik MA, Wie J, Suo Y, Borschel WF, Ren D, Lander GC, Lee SY. Cryo-electron microscopy structure of the lysosomal calcium-permeable channel TRPML3. Nature 2017; 550:411-414. [PMID: 29019979 PMCID: PMC5762132 DOI: 10.1038/nature24055] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Accepted: 09/01/2017] [Indexed: 01/09/2023]
Abstract
The modulation of ion channel activity by lipids is increasingly recognized as a fundamental component of cellular signalling. The transient receptor potential mucolipin (TRPML) channel family belongs to the TRP superfamily and is composed of three members: TRPML1-TRPML3. TRPMLs are the major Ca2+-permeable channels on late endosomes and lysosomes (LEL). They regulate the release of Ca2+ from organelles, which is important for various physiological processes, including organelle trafficking and fusion. Loss-of-function mutations in the MCOLN1 gene, which encodes TRPML1, cause the neurodegenerative lysosomal storage disorder mucolipidosis type IV, and a gain-of-function mutation (Ala419Pro) in TRPML3 gives rise to the varitint-waddler (Va) mouse phenotype. Notably, TRPML channels are activated by the low-abundance and LEL-enriched signalling lipid phosphatidylinositol-3,5-bisphosphate (PtdIns(3,5)P2), whereas other phosphoinositides such as PtdIns(4,5)P2, which is enriched in plasma membranes, inhibit TRPMLs. Conserved basic residues at the N terminus of the channel are important for activation by PtdIns(3,5)P2 and inhibition by PtdIns(4,5)P2. However, owing to a lack of structural information, the mechanism by which TRPML channels recognize PtdIns(3,5)P2 and increase their Ca2+ conductance remains unclear. Here we present the cryo-electron microscopy (cryo-EM) structure of a full-length TRPML3 channel from the common marmoset (Callithrix jacchus) at an overall resolution of 2.9 Å. Our structure reveals not only the molecular basis of ion conduction but also the unique architecture of TRPMLs, wherein the voltage sensor-like domain is linked to the pore via a cytosolic domain that we term the mucolipin domain. Combined with functional studies, these data suggest that the mucolipin domain is responsible for PtdIns(3,5)P2 binding and subsequent channel activation, and that it acts as a 'gating pulley' for lipid-dependent TRPML gating.
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Affiliation(s)
- Marscha Hirschi
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710, USA
| | - Mark A Herzik
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Jinhong Wie
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Yang Suo
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710, USA
| | - William F Borschel
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710, USA
| | - Dejian Ren
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Gabriel C Lander
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Seok-Yong Lee
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710, USA
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588
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Houben T, Oligschlaeger Y, Bitorina AV, Hendrikx T, Walenbergh SMA, Lenders MH, Gijbels MJJ, Verheyen F, Lütjohann D, Hofker MH, Binder CJ, Shiri-Sverdlov R. Blood-derived macrophages prone to accumulate lysosomal lipids trigger oxLDL-dependent murine hepatic inflammation. Sci Rep 2017; 7:12550. [PMID: 28970532 PMCID: PMC5624963 DOI: 10.1038/s41598-017-13058-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 09/18/2017] [Indexed: 12/31/2022] Open
Abstract
Despite the consistent rise of non-alcoholic steatohepatitis (NASH) worldwide, the mechanisms that govern the inflammatory aspect of this disease remain unknown. Previous research showed an association between hepatic inflammation and lysosomal lipid accumulation in blood-derived hepatic macrophages. Additionally, in vitro findings indicated that lipids, specifically derived from the oxidized low-density lipoprotein (oxLDL) particle, are resistant to removal from lysosomes. On this basis, we investigated whether lysosomal lipid accumulation in blood-derived hepatic macrophages is causally linked to hepatic inflammation and assessed to what extent increasing anti-oxLDL IgM autoantibodies can affect this mechanism. By creating a proof-of-concept mouse model, we demonstrate a causal role for lysosomal lipids in blood-derived hepatic macrophages in mediating hepatic inflammation and initiation of fibrosis. Furthermore, our findings show that increasing anti-oxLDL IgM autoantibody levels reduces inflammation. Hence, therapies aimed at improving lipid-induced lysosomal dysfunction and blocking oxLDL-formation deserve further investigation in the context of NASH.
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Affiliation(s)
- Tom Houben
- Departments of Molecular Genetics, Molecular Cell Biology and Electron Microscopy, School of Nutrition and Translational Research in Metabolism (NUTRIM), University of Maastricht; Universiteitssingel 50, ER 6229 ER, Maastricht, The Netherlands
| | - Yvonne Oligschlaeger
- Departments of Molecular Genetics, Molecular Cell Biology and Electron Microscopy, School of Nutrition and Translational Research in Metabolism (NUTRIM), University of Maastricht; Universiteitssingel 50, ER 6229 ER, Maastricht, The Netherlands
| | - Albert V Bitorina
- Departments of Molecular Genetics, Molecular Cell Biology and Electron Microscopy, School of Nutrition and Translational Research in Metabolism (NUTRIM), University of Maastricht; Universiteitssingel 50, ER 6229 ER, Maastricht, The Netherlands
| | - Tim Hendrikx
- Departments of Molecular Genetics, Molecular Cell Biology and Electron Microscopy, School of Nutrition and Translational Research in Metabolism (NUTRIM), University of Maastricht; Universiteitssingel 50, ER 6229 ER, Maastricht, The Netherlands
| | - Sofie M A Walenbergh
- Departments of Molecular Genetics, Molecular Cell Biology and Electron Microscopy, School of Nutrition and Translational Research in Metabolism (NUTRIM), University of Maastricht; Universiteitssingel 50, ER 6229 ER, Maastricht, The Netherlands
| | - Marie-Hélène Lenders
- Departments of Molecular Genetics, Molecular Cell Biology and Electron Microscopy, School of Nutrition and Translational Research in Metabolism (NUTRIM), University of Maastricht; Universiteitssingel 50, ER 6229 ER, Maastricht, The Netherlands
| | - Marion J J Gijbels
- Departments of Molecular Genetics, Molecular Cell Biology and Electron Microscopy, School of Nutrition and Translational Research in Metabolism (NUTRIM), University of Maastricht; Universiteitssingel 50, ER 6229 ER, Maastricht, The Netherlands
| | - Fons Verheyen
- Departments of Molecular Genetics, Molecular Cell Biology and Electron Microscopy, School of Nutrition and Translational Research in Metabolism (NUTRIM), University of Maastricht; Universiteitssingel 50, ER 6229 ER, Maastricht, The Netherlands
| | - Dieter Lütjohann
- Institute of Clinical Chemistry and Clinical Pharmacology, University of Bonn; Sigmund-Freud-Str. 25, D-53127, Bonn, Germany
| | - Marten H Hofker
- Department of Pathology and Medical Biology, Molecular Genetics, Medical Biology Section, University of Groningen, University Medical Center Groningen; Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Christoph J Binder
- Department of Laboratory Medicine, Medical University of Vienna; Spitalgasse 23, 1090, Vienna, Austria
- Center for Molecular Medicine (CeMM), Austrian Academy of Sciences; Lazarettgasse 14, A-1090, Vienna, Austria
| | - Ronit Shiri-Sverdlov
- Departments of Molecular Genetics, Molecular Cell Biology and Electron Microscopy, School of Nutrition and Translational Research in Metabolism (NUTRIM), University of Maastricht; Universiteitssingel 50, ER 6229 ER, Maastricht, The Netherlands.
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589
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Sahoo N, Gu M, Zhang X, Raval N, Yang J, Bekier M, Calvo R, Patnaik S, Wang W, King G, Samie M, Gao Q, Sahoo S, Sundaresan S, Keeley TM, Wang Y, Marugan J, Ferrer M, Samuelson LC, Merchant JL, Xu H. Gastric Acid Secretion from Parietal Cells Is Mediated by a Ca 2+ Efflux Channel in the Tubulovesicle. Dev Cell 2017; 41:262-273.e6. [PMID: 28486130 DOI: 10.1016/j.devcel.2017.04.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 03/10/2017] [Accepted: 04/03/2017] [Indexed: 12/12/2022]
Abstract
Gastric acid secretion by parietal cells requires trafficking and exocytosis of H/K-ATPase-rich tubulovesicles (TVs) toward apical membranes in response to histamine stimulation via cyclic AMP elevation. Here, we found that TRPML1 (ML1), a protein that is mutated in type IV mucolipidosis (ML-IV), is a tubulovesicular channel essential for TV exocytosis and acid secretion. Whereas ML-IV patients are reportedly achlorhydric, transgenic overexpression of ML1 in mouse parietal cells induced constitutive acid secretion. Gastric acid secretion was blocked and stimulated by ML1 inhibitors and agonists, respectively. Organelle-targeted Ca2+ imaging and direct patch-clamping of apical vacuolar membranes revealed that ML1 mediates a PKA-activated conductance on TV membranes that is required for histamine-induced Ca2+ release from TV stores. Hence, we demonstrated that ML1, acting as a Ca2+ channel in TVs, links transmitter-initiated cyclic nucleotide signaling with Ca2+-dependent TV exocytosis in parietal cells, providing a regulatory mechanism that could be targeted to manage acid-related gastric diseases.
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Affiliation(s)
- Nirakar Sahoo
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Mingxue Gu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Xiaoli Zhang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Neel Raval
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Junsheng Yang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA; Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, China
| | - Michael Bekier
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Raul Calvo
- National Center for Advancing Translational Sciences, National Institute of Health, 9800 Medical Center Drive, Rockville, MD 20850, USA
| | - Samarjit Patnaik
- National Center for Advancing Translational Sciences, National Institute of Health, 9800 Medical Center Drive, Rockville, MD 20850, USA
| | - Wuyang Wang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Greyson King
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Mohammad Samie
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Qiong Gao
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Sasmita Sahoo
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Sinju Sundaresan
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Theresa M Keeley
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yanzhuang Wang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Juan Marugan
- National Center for Advancing Translational Sciences, National Institute of Health, 9800 Medical Center Drive, Rockville, MD 20850, USA
| | - Marc Ferrer
- National Center for Advancing Translational Sciences, National Institute of Health, 9800 Medical Center Drive, Rockville, MD 20850, USA
| | - Linda C Samuelson
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Juanita L Merchant
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Haoxing Xu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA.
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590
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Abstract
The evolution of a nervous system as a control system of the body's functions is a key innovation of animals. Its fundamental units are neurons, highly specialized cells dedicated to fast cell-cell communication. Neurons pass signals to other neurons, muscle cells, or gland cells at specialized junctions, the synapses, where transmitters are released from vesicles in a Ca2+-dependent fashion to activate receptors in the membrane of the target cell. Reconstructing the origins of neuronal communication out of a more simple process remains a central challenge in biology. Recent genomic comparisons have revealed that all animals, including the nerveless poriferans and placozoans, share a basic set of genes for neuronal communication. This suggests that the first animal, the Urmetazoan, was already endowed with neurosecretory cells that probably started to connect into neuronal networks soon afterward. Here, we discuss scenarios for this pivotal transition in animal evolution.
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Affiliation(s)
- Frederique Varoqueaux
- Département des Neurosciences Fondamentales, Université de Lausanne, Lausanne, CH-1005 Switzerland; ,
| | - Dirk Fasshauer
- Département des Neurosciences Fondamentales, Université de Lausanne, Lausanne, CH-1005 Switzerland; ,
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591
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Nixon RA. Amyloid precursor protein and endosomal-lysosomal dysfunction in Alzheimer's disease: inseparable partners in a multifactorial disease. FASEB J 2017; 31:2729-2743. [PMID: 28663518 DOI: 10.1096/fj.201700359] [Citation(s) in RCA: 213] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 04/21/2017] [Indexed: 12/15/2022]
Abstract
Abnormalities of the endosomal-lysosomal network (ELN) are a signature feature of Alzheimer's disease (AD). These include the earliest known cytopathology that is specific to AD and that affects endosomes and induces the progressive failure of lysosomes, each of which are directly linked by distinct mechanisms to neurodegeneration. The origins of ELN dysfunction and β-amyloidogenesis closely overlap, which reflects their common genetic basis, the established early involvement of endosomes and lysosomes in amyloid precursor protein (APP) processing and clearance, and the pathologic effect of certain APP metabolites on ELN functions. Genes that promote β-amyloidogenesis in AD (APP, PSEN1/2, and APOE4) have primary effects on ELN function. The importance of primary ELN dysfunction to pathogenesis is underscored by the mutations in more than 35 ELN-related genes that, thus far, are known to cause familial neurodegenerative diseases even though different pathogenic proteins may be involved. In this article, I discuss growing evidence that implicates AD gene-driven ELN disruptions as not only the antecedent pathobiology that underlies β-amyloidogenesis but also as the essential partner with APP and its metabolites that drive the development of AD, including tauopathy, synaptic dysfunction, and neurodegeneration. The striking amelioration of diverse deficits in animal AD models by remediating ELN dysfunction further supports a need to integrate APP and ELN relationships, including the role of amyloid-β, into a broader conceptual framework of how AD arises, progresses, and may be effectively therapeutically targeted.-Nixon, R. A. Amyloid precursor protein and endosomal-lysosomal dysfunction in Alzheimer's disease: inseparable partners in a multifactorial disease.
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Affiliation(s)
- Ralph A Nixon
- Center for Dementia Research, Nathan S. Kline Institute, Orangeburg, New York, USA; .,Department of Psychiatry and Department of Cell Biology, New York University Langone Medical Center, New York, New York, USA
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592
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Sharma A, Vaghasiya K, Ray E, Verma RK. Lysosomal targeting strategies for design and delivery of bioactive for therapeutic interventions. J Drug Target 2017; 26:208-221. [DOI: 10.1080/1061186x.2017.1374390] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Ankur Sharma
- Institute of Nano Science and Technology (INST), Phase 10, Mohali, India
| | - Kalpesh Vaghasiya
- Institute of Nano Science and Technology (INST), Phase 10, Mohali, India
| | - Eupa Ray
- Institute of Nano Science and Technology (INST), Phase 10, Mohali, India
| | - Rahul Kumar Verma
- Institute of Nano Science and Technology (INST), Phase 10, Mohali, India
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593
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Martinez-Carreres L, Nasrallah A, Fajas L. Cancer: Linking Powerhouses to Suicidal Bags. Front Oncol 2017; 7:204. [PMID: 28932704 PMCID: PMC5592205 DOI: 10.3389/fonc.2017.00204] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 08/21/2017] [Indexed: 11/26/2022] Open
Abstract
Membrane-bound organelles are integrated into cellular networks and work together for a common goal: regulating cell metabolism, cell signaling pathways, cell fate, cellular maintenance, and pathogen defense. Many of these interactions are well established, but little is known about the interplay between mitochondria and lysosomes, and their deregulation in cancer. The present review focuses on the common signaling pathways of both organelles, as well as the processes in which they both physically interact, their changes under pathological conditions, and the impact on targeting those organelles for treating cancer.
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Affiliation(s)
- Laia Martinez-Carreres
- Cancer and Metabolism Laboratory, Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Anita Nasrallah
- Cancer and Metabolism Laboratory, Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Lluis Fajas
- Cancer and Metabolism Laboratory, Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
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594
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Castonguay J, Orth JHC, Müller T, Sleman F, Grimm C, Wahl-Schott C, Biel M, Mallmann RT, Bildl W, Schulte U, Klugbauer N. The two-pore channel TPC1 is required for efficient protein processing through early and recycling endosomes. Sci Rep 2017; 7:10038. [PMID: 28855648 PMCID: PMC5577145 DOI: 10.1038/s41598-017-10607-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 08/11/2017] [Indexed: 02/06/2023] Open
Abstract
Two-pore channels (TPCs) are localized in endo-lysosomal compartments and assumed to play an important role for vesicular fusion and endosomal trafficking. Recently, it has been shown that both TPC1 and 2 were required for host cell entry and pathogenicity of Ebola viruses. Here, we investigate the cellular function of TPC1 using protein toxins as model substrates for distinct endosomal processing routes. Toxin uptake and activation through early endosomes but not processing through other compartments were reduced in TPC1 knockout cells. Detailed co-localization studies with subcellular markers confirmed predominant localization of TPC1 to early and recycling endosomes. Proteomic analysis of native TPC1 channels finally identified direct interaction with a distinct set of syntaxins involved in fusion of intracellular vesicles. Together, our results demonstrate a general role of TPC1 for uptake and processing of proteins in early and recycling endosomes, likely by providing high local Ca2+ concentrations required for SNARE-mediated vesicle fusion.
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Affiliation(s)
- Jan Castonguay
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Albertstrasse 25, 79104, Freiburg, Germany
| | - Joachim H C Orth
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Albertstrasse 25, 79104, Freiburg, Germany
| | - Thomas Müller
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Albertstrasse 25, 79104, Freiburg, Germany
| | - Faten Sleman
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Albertstrasse 25, 79104, Freiburg, Germany
| | - Christian Grimm
- Department of Pharmacy, Center for Drug Research and Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-University, Munich, Germany
| | - Christian Wahl-Schott
- Department of Pharmacy, Center for Drug Research and Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-University, Munich, Germany
| | - Martin Biel
- Department of Pharmacy, Center for Drug Research and Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-University, Munich, Germany
| | - Robert Theodor Mallmann
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Albertstrasse 25, 79104, Freiburg, Germany
| | - Wolfgang Bildl
- Institute of Physiology II, Faculty of Medicine, Albert-Ludwigs-University, Hermann-Herder-Strasse 7, 79104, Freiburg, Germany
| | - Uwe Schulte
- Institute of Physiology II, Faculty of Medicine, Albert-Ludwigs-University, Hermann-Herder-Strasse 7, 79104, Freiburg, Germany.,Logopharm GmbH, Schlossstrasse 14, 79232, March-Buchheim, Germany.,Center for Biological Signaling Studies (BIOSS), Schänzlestrasse 18, 79104, Freiburg, Germany
| | - Norbert Klugbauer
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University, Albertstrasse 25, 79104, Freiburg, Germany.
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595
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Zheng K, Jiang Y, Liao C, Hu X, Li Y, Zeng Y, Zhang J, Wu X, Wu H, Liu L, Wang Y, He Z. NOX2-Mediated TFEB Activation and Vacuolization Regulate Lysosome-Associated Cell Death Induced by Gypenoside L, a Saponin Isolated from Gynostemma pentaphyllum. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:6625-6637. [PMID: 28697598 DOI: 10.1021/acs.jafc.7b02296] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Downregulation of apoptotic signal pathway and activation of protective autophagy mainly contribute to the chemoresistance of tumor cells. Therefore, exploring efficient chemotherapeutic agents or isolating novel natural products that can trigger nonapoptotic and nonautophagic cell death such as lysosome-associated death is emergently required. We have recently extracted a saponin, gypenoside L (Gyp-L), from Gynostemma pentaphyllum and showed that Gyp-L was able to induce nonapoptotic cell death of esophageal cancer cells associated with lysosome swelling. However, contributions of vacuolization and lysosome to cell death remain unclear. Herein, we reveal a critical role for NADPH oxidase NOX2-mediated vacuolization and transcription factor EB (TFEB) activation in lysosome-associated cell death. We found that Gyp-L initially induced the abnormal enlarged and alkalized vacuoles, which were derived from lipid rafts dependent endocytosis. Besides, NOX2 was activated to promote vacuolization and mTORC1-independent TFEB-mediated lysosome biogenesis. Finally, raising lysosome pH could enhance Gyp-L induced cell death. These findings suggest a protective role of NOX2-TFEB-mediated lysosome biogenesis in cancer drug resistance and the tight interaction between lipid rafts and vacuolization. In addition, Gyp-L can be utilized as an alternative option to overcome drug-resistance though inducing lysosome associated cell death.
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Affiliation(s)
- Kai Zheng
- Department of Pharmacy, School of Medicine; Shenzhen Key Laboratory of Novel Natural Health Care Products; Innovation Platform for Natural Small Molecule Drugs; Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University , Shenzhen 518060, China
- College of Life Science and Technology, Jinan University , Guangzhou 510632, China
| | - Yingchun Jiang
- Department of Pharmacy, School of Medicine; Shenzhen Key Laboratory of Novel Natural Health Care Products; Innovation Platform for Natural Small Molecule Drugs; Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University , Shenzhen 518060, China
| | - Chenghui Liao
- Department of Pharmacy, School of Medicine; Shenzhen Key Laboratory of Novel Natural Health Care Products; Innovation Platform for Natural Small Molecule Drugs; Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University , Shenzhen 518060, China
| | - Xiaopeng Hu
- Department of Pharmacy, School of Medicine; Shenzhen Key Laboratory of Novel Natural Health Care Products; Innovation Platform for Natural Small Molecule Drugs; Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University , Shenzhen 518060, China
| | - Yan Li
- The First Affiliated Hospital of Kunming Medical University , Kunming 650032, China
| | - Yong Zeng
- The First Affiliated Hospital of Kunming Medical University , Kunming 650032, China
| | - Jian Zhang
- Department of Pharmacy, School of Medicine; Shenzhen Key Laboratory of Novel Natural Health Care Products; Innovation Platform for Natural Small Molecule Drugs; Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University , Shenzhen 518060, China
| | - Xuli Wu
- Department of Pharmacy, School of Medicine; Shenzhen Key Laboratory of Novel Natural Health Care Products; Innovation Platform for Natural Small Molecule Drugs; Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University , Shenzhen 518060, China
| | - Haiqiang Wu
- Department of Pharmacy, School of Medicine; Shenzhen Key Laboratory of Novel Natural Health Care Products; Innovation Platform for Natural Small Molecule Drugs; Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University , Shenzhen 518060, China
| | - Lizhong Liu
- Department of Pharmacy, School of Medicine; Shenzhen Key Laboratory of Novel Natural Health Care Products; Innovation Platform for Natural Small Molecule Drugs; Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University , Shenzhen 518060, China
| | - Yifei Wang
- College of Life Science and Technology, Jinan University , Guangzhou 510632, China
| | - Zhendan He
- Department of Pharmacy, School of Medicine; Shenzhen Key Laboratory of Novel Natural Health Care Products; Innovation Platform for Natural Small Molecule Drugs; Engineering Laboratory of Shenzhen Natural Small Molecule Innovative Drugs, Shenzhen University , Shenzhen 518060, China
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596
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Duncan R. Polymer therapeutics at a crossroads? Finding the path for improved translation in the twenty-first century. J Drug Target 2017; 25:759-780. [PMID: 28783978 DOI: 10.1080/1061186x.2017.1358729] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Despite the relatively small early investment, first generation 'polymer therapeutics' have been remarkably successful with more than 25 products licenced for human use as polymeric drugs, sequestrants, conjugates, and as an imaging agent. Many exhibit both clinical and commercial success with new concepts already in clinical trials. Nevertheless after four decades of evolution, this field is arriving at an important crossroads. Over the last decade, the landscape has changed rapidly. There are an increasing number of failed clinical trials, the number of 'copy' and 'generic' products is growing (danger of ignoring the biological rationale for design and suppression of innovation), potential drawbacks of PEG are becoming more evident, and the 'nanomedicine' boom has brought danger of loss of scientific focus/hype. Grasping opportunities provided by advances in understanding of the patho-physiology and molecular basis of diseases, new polymer/conjugate synthetic and analytical methods, as well as the large database of clinical experience will surely ensure a successful future for innovative polymer therapeutics. Progress will, however, be in jeopardy if polymer safety is overlooked in respect of the specific route of administration/clinical use, poorly characterised materials/formulations are used to define biological or early clinical properties, and if clinical trial protocols fail to select patients most likely to benefit from these macromolecular therapeutics. Opportunities to improve clinical trial design for polymer-anticancer drug conjugates are discussed. This short personal perspective summarises some of the important challenges facing polymer therapeutics in R&D today, and future opportunities to improve successful translation.
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Affiliation(s)
- Ruth Duncan
- a Polymer Therapeutics Laboratory , Centro de Investigación Príncipe Felipe , Valencia , Spain.,b Intracellular Delivery Solutions Laboratory, Faculty of Engineering and Science , University of Greenwich , Kent , UK
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597
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Pham CD, Smith CE, Hu Y, Hu JCC, Simmer JP, Chun YHP. Endocytosis and Enamel Formation. Front Physiol 2017; 8:529. [PMID: 28824442 PMCID: PMC5534449 DOI: 10.3389/fphys.2017.00529] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 07/10/2017] [Indexed: 12/12/2022] Open
Abstract
Enamel formation requires consecutive stages of development to achieve its characteristic extreme mineral hardness. Mineralization depends on the initial presence then removal of degraded enamel proteins from the matrix via endocytosis. The ameloblast membrane resides at the interface between matrix and cell. Enamel formation is controlled by ameloblasts that produce enamel in stages to build the enamel layer (secretory stage) and to reach final mineralization (maturation stage). Each stage has specific functional requirements for the ameloblasts. Ameloblasts adopt different cell morphologies during each stage. Protein trafficking including the secretion and endocytosis of enamel proteins is a fundamental task in ameloblasts. The sites of internalization of enamel proteins on the ameloblast membrane are specific for every stage. In this review, an overview of endocytosis and trafficking of vesicles in ameloblasts is presented. The pathways for internalization and routing of vesicles are described. Endocytosis is proposed as a mechanism to remove debris of degraded enamel protein and to obtain feedback from the matrix on the status of the maturing enamel.
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Affiliation(s)
- Cong-Dat Pham
- Department of Periodontics, School of Dentistry, University of Texas Health Science Center at San AntonioSan Antonio, TX, United States
| | - Charles E. Smith
- Department of Anatomy and Cell Biology, McGill UniversityMontreal, QC, Canada
- Department of Biologic and Materials Sciences, University of MichiganAnn Arbor, MI, United States
| | - Yuanyuan Hu
- Department of Biologic and Materials Sciences, University of MichiganAnn Arbor, MI, United States
| | - Jan C-C. Hu
- Department of Biologic and Materials Sciences, University of MichiganAnn Arbor, MI, United States
| | - James P. Simmer
- Department of Biologic and Materials Sciences, University of MichiganAnn Arbor, MI, United States
| | - Yong-Hee P. Chun
- Department of Periodontics, School of Dentistry, University of Texas Health Science Center at San AntonioSan Antonio, TX, United States
- Department of Cell Systems & Anatomy, School of Medicine, University of Texas Health Science Center at San AntonioSan Antonio, TX, United States
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598
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Kintzer AF, Stroud RM. On the structure and mechanism of two-pore channels. FEBS J 2017; 285:233-243. [PMID: 28656706 DOI: 10.1111/febs.14154] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/24/2017] [Accepted: 06/23/2017] [Indexed: 12/22/2022]
Abstract
In eukaryotes, two-pore channels (TPC1-3) comprise a family of ion channels that regulate the conductance of Na+ and Ca2+ ions across cellular membranes. TPC1-3 form endolysosomal channels, but TPC3 can also function in the plasma membrane. TPC1/3 are voltage-gated channels, but TPC2 opens in response to binding endolysosome-specific lipid phosphatidylinositol-3,5-diphosphate (PI(3,5)P2 ). Filoviruses, such as Ebola, exploit TPC-mediated ion release as a means of escape from the endolysosome during infection. Antagonists that block TPC1/2 channel conductance abrogate filoviral infections. TPC1/2 form complexes with the mechanistic target of rapamycin complex 1 (mTORC1) at the endolysosomal surface that couple cellular metabolic state and cytosolic nutrient concentrations to the control of membrane potential and pH. We determined the X-ray structure of TPC1 from Arabidopsis thaliana (AtTPC1) to 2.87Å resolution-one of the two first reports of a TPC channel structure. Here, we summarize these findings and the implications that the structure may have for understanding endolysosomal control mechanisms and their role in human health.
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Affiliation(s)
- Alexander F Kintzer
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA
| | - Robert M Stroud
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA
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599
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Chakraborty K, Leung K, Krishnan Y. High lumenal chloride in the lysosome is critical for lysosome function. eLife 2017; 6. [PMID: 28742019 PMCID: PMC5526669 DOI: 10.7554/elife.28862] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 06/23/2017] [Indexed: 12/31/2022] Open
Abstract
Lysosomes are organelles responsible for the breakdown and recycling of cellular machinery. Dysfunctional lysosomes give rise to lysosomal storage disorders as well as common neurodegenerative diseases. Here, we use a DNA-based, fluorescent chloride reporter to measure lysosomal chloride in Caenorhabditis elegans as well as murine and human cell culture models of lysosomal diseases. We find that the lysosome is highly enriched in chloride, and that chloride reduction correlates directly with a loss in the degradative function of the lysosome. In nematodes and mammalian cell culture models of diverse lysosomal disorders, where previously only lysosomal pH dysregulation has been described, massive reduction of lumenal chloride is observed that is ~103 fold greater than the accompanying pH change. Reducing chloride within the lysosome impacts Ca2+ release from the lysosome and impedes the activity of specific lysosomal enzymes indicating a broader role for chloride in lysosomal function. DOI:http://dx.doi.org/10.7554/eLife.28862.001 In cells, worn out proteins and other unnecessary materials are sent to small compartments called lysosomes to be broken down and recycled. Lysosomes contain many different proteins including some that break down waste material into recyclable fragments and others that transport the fragments out of the lysosome. If any of these proteins do not work, waste products build up and cause disease. There are around 70 such lysosomal storage diseases, each arising from a different lysosomal protein not working correctly. A recently developed “nanodevice” called Clensor can measure the levels of chloride ions inside cells. Clensor is constructed from DNA, and its fluorescence changes when it detects chloride ions. Although chloride ions have many biological roles, chloride ion levels had not been measured inside a living organism. Now, Chakraborty et al. – including some of the researchers who developed Clensor – have used this nanodevice to examine chloride ion levels in the lysosomes of the roundworm Caenorhabditis elegans. This revealed that the lysosomes contain high levels of chloride ions. Furthermore, reducing the amount of chloride in the lysosomes made them worse at breaking down waste. Do lysosomes affected by lysosome storage diseases also contain low levels of chloride ions? To find out, Chakraborty et al. used Clensor to study C. elegans worms and mouse and human cells whose lysosomes accumulate waste products. In all these cases, the levels of chloride in the diseased lysosomes were much lower than normal. This had a number of effects on how the lysosomes worked, such as reducing the activity of key lysosomal proteins. Chakraborty et al. also found that Clensor can be used to distinguish between different lysosomal storage diseases. This means that in the future, Clensor (or similar methods that directly measure chloride ion levels in lysosomes) may be useful not just for research purposes. They may also be valuable for diagnosing lysosomal storage diseases early in infancy that, if left undiagnosed, are fatal. DOI:http://dx.doi.org/10.7554/eLife.28862.002
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Affiliation(s)
- Kasturi Chakraborty
- Department of Chemistry, University of Chicago, Chicago, United States.,Grossman Institute of Neuroscience, Quantitative Biology and Human Behavior, University of Chicago, Chicago, United States
| | - KaHo Leung
- Department of Chemistry, University of Chicago, Chicago, United States.,Grossman Institute of Neuroscience, Quantitative Biology and Human Behavior, University of Chicago, Chicago, United States
| | - Yamuna Krishnan
- Department of Chemistry, University of Chicago, Chicago, United States.,Grossman Institute of Neuroscience, Quantitative Biology and Human Behavior, University of Chicago, Chicago, United States
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600
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Patch-clamp technique to characterize ion channels in enlarged individual endolysosomes. Nat Protoc 2017; 12:1639-1658. [PMID: 28726848 DOI: 10.1038/nprot.2017.036] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
According to proteomics analyses, more than 70 different ion channels and transporters are harbored in membranes of intracellular compartments such as endosomes and lysosomes. Malfunctioning of these channels has been implicated in human diseases such as lysosomal storage disorders, neurodegenerative diseases and metabolic pathologies, as well as in the progression of certain infectious diseases. As a consequence, these channels have engendered very high interest as future drug targets. Detailed electrophysiological characterization of intracellular ion channels is lacking, mainly because standard methods to analyze plasma membrane ion channels, such as the patch-clamp technique, are not readily applicable to intracellular organelles. Here we present a protocol detailing how to implement a manual patch-clamp technique for endolysosomal compartments. In contrast to the alternatively used planar endolysosomal patch-clamp technique, this method is a visually controlled, direct patch-clamp technique similar to conventional patch-clamping. The protocol assumes basic knowledge and experience with patch-clamp methods. Implementation of the method requires up to 1 week, and material preparation takes ∼2-4 d. An individual experiment (i.e., measurement of channel currents across the endolysosomal membrane), including control experiments, can be completed within 1 h. This excludes the time for endolysosome enlargement, which takes between 1 and 48 h, depending on the approach and cell type used. Data analysis requires an additional hour.
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