1
|
Sangster ML, Bishop MM, Yao Y, Feitor JF, Shahriar S, Miller ME, Chekuri AK, Budnik B, Bei F, Grishchuk Y. A blood-brain barrier-penetrant AAV gene therapy improves neurological function in symptomatic mucolipidosis IV mice. Mol Ther Methods Clin Dev 2024; 32:101269. [PMID: 38934011 PMCID: PMC11201152 DOI: 10.1016/j.omtm.2024.101269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 05/17/2024] [Indexed: 06/28/2024]
Abstract
Mucolipidosis IV (MLIV) is a rare, autosomal recessive, lysosomal disease characterized by intellectual disability, motor deficits, and progressive vision loss. Using adeno-associated vector 9 (AAV9) and AAV-PHP.B as delivery vectors, we previously demonstrated the feasibility of modifying disease course in a mouse model of MLIV by the human MCOLN1 gene transfer. Here, using a primate-enabling capsid AAV.CPP.16 (CPP16), we constructed a new, clinic-oriented MCOLN1 gene expression vector and demonstrated its efficacy in the preclinical model of MLIV. Systemic administration of CPP16-MCOLN1 in adult symptomatic Mcoln1 -/- mice at a dose of 1e12 vg per mouse resulted in MCOLN1 expression in the brain and peripheral tissues, alleviated brain pathology, rescued neuromotor function, and completely prevented paralysis. Notable expression of MCOLN1 transcripts was also detected in the retina of the mouse, which had exhibited significant degeneration at the time of the treatment. However, no increase in retinal thickness was observed after gene therapy treatment. Our results suggest a new AAV-based systemic gene replacement therapy for the treatment of MLIV that could be translated into clinical studies.
Collapse
Affiliation(s)
- Madison L. Sangster
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, 185 Cambridge St, Boston, MA 02114, USA
| | - Martha M. Bishop
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, 185 Cambridge St, Boston, MA 02114, USA
| | - Yizheng Yao
- Department of Neurosurgery, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis St, Boston, MA 02115, USA
| | - Jessica F. Feitor
- Wyss Institute for Biologically Inspired Engineering, Harvard University, 201 Brookline Avenue, Boston, MA 02215, USA
| | - Sanjid Shahriar
- Wyss Institute for Biologically Inspired Engineering, Harvard University, 201 Brookline Avenue, Boston, MA 02215, USA
| | - Maxwell E. Miller
- Grousbeck Gene Therapy Center, Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, 20 Staniford St, Boston, MA 02114, USA
| | - Anil K. Chekuri
- Grousbeck Gene Therapy Center, Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, 20 Staniford St, Boston, MA 02114, USA
| | - Bogdan Budnik
- Wyss Institute for Biologically Inspired Engineering, Harvard University, 201 Brookline Avenue, Boston, MA 02215, USA
| | - Fengfeng Bei
- Department of Neurosurgery, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis St, Boston, MA 02115, USA
| | - Yulia Grishchuk
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute and Harvard Medical School, 185 Cambridge St, Boston, MA 02114, USA
| |
Collapse
|
2
|
Vestuto V, Di Sarno V, Musella S, Di Dona G, Moltedo O, Gomez-Monterrey IM, Bertamino A, Ostacolo C, Campiglia P, Ciaglia T. New Frontiers on ER Stress Modulation: Are TRP Channels the Leading Actors? Int J Mol Sci 2022; 24:185. [PMID: 36613628 PMCID: PMC9820239 DOI: 10.3390/ijms24010185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/15/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022] Open
Abstract
The endoplasmic reticulum (ER) is a dynamic structure, playing multiple roles including calcium storage, protein synthesis and lipid metabolism. During cellular stress, variations in ER homeostasis and its functioning occur. This condition is referred as ER stress and generates a cascade of signaling events termed unfolded protein response (UPR), activated as adaptative response to mitigate the ER stress condition. In this regard, calcium levels play a pivotal role in ER homeostasis and therefore in cell fate regulation since calcium signaling is implicated in a plethora of physiological processes, but also in disease conditions such as neurodegeneration, cancer and metabolic disorders. A large body of emerging evidence highlighted the functional role of TRP channels and their ability to promote cell survival or death depending on endoplasmic reticulum stress resolution, making them an attractive target. Thus, in this review we focused on the TRP channels' correlation to UPR-mediated ER stress in disease pathogenesis, providing an overview of their implication in the activation of this cellular response.
Collapse
Affiliation(s)
- Vincenzo Vestuto
- Department of Pharmacy, University of Salerno, Via G. Paolo II, 84084 Fisciano, SA, Italy
| | - Veronica Di Sarno
- Department of Pharmacy, University of Salerno, Via G. Paolo II, 84084 Fisciano, SA, Italy
| | - Simona Musella
- Department of Pharmacy, University of Salerno, Via G. Paolo II, 84084 Fisciano, SA, Italy
| | - Giorgio Di Dona
- Pineta Grande Hospital, Via Domiziana, km 30/00, 81030 Castel Volturno, CE, Italy
| | - Ornella Moltedo
- Department of Pharmacy, University of Salerno, Via G. Paolo II, 84084 Fisciano, SA, Italy
| | | | - Alessia Bertamino
- Department of Pharmacy, University of Salerno, Via G. Paolo II, 84084 Fisciano, SA, Italy
| | - Carmine Ostacolo
- Department of Pharmacy, University of Salerno, Via G. Paolo II, 84084 Fisciano, SA, Italy
- Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131 Napoli, NA, Italy
| | - Pietro Campiglia
- Department of Pharmacy, University of Salerno, Via G. Paolo II, 84084 Fisciano, SA, Italy
- European Biomedical Research Institute of Salerno, Via S. De Renzi 50, 84125 Salerno, SA, Italy
| | - Tania Ciaglia
- Department of Pharmacy, University of Salerno, Via G. Paolo II, 84084 Fisciano, SA, Italy
| |
Collapse
|
3
|
Liu Y, Lyu Y, Wang H. TRP Channels as Molecular Targets to Relieve Endocrine-Related Diseases. Front Mol Biosci 2022; 9:895814. [PMID: 35573736 PMCID: PMC9095829 DOI: 10.3389/fmolb.2022.895814] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 03/28/2022] [Indexed: 12/03/2022] Open
Abstract
Transient receptor potential (TRP) channels are polymodal channels capable of sensing environmental stimuli, which are widely expressed on the plasma membrane of cells and play an essential role in the physiological or pathological processes of cells as sensors. TRPs often form functional homo- or heterotetramers that act as cation channels to flow Na+ and Ca2+, change membrane potential and [Ca2+]i (cytosolic [Ca2+]), and change protein expression levels, channel attributes, and regulatory factors. Under normal circumstances, various TRP channels respond to intracellular and extracellular stimuli such as temperature, pH, osmotic pressure, chemicals, cytokines, and cell damage and depletion of Ca2+ reserves. As cation transport channels and physical and chemical stimulation receptors, TRPs play an important role in regulating secretion, interfering with cell proliferation, and affecting neural activity in these glands and their adenocarcinoma cells. Many studies have proved that TRPs are widely distributed in the pancreas, adrenal gland, and other glands. This article reviews the specific regulatory mechanisms of various TRP channels in some common glands (pancreas, salivary gland, lacrimal gland, adrenal gland, mammary gland, gallbladder, and sweat gland).
Collapse
|
4
|
Wang H, Dong Y, Wan B, Ji Y, Xu Q. Identification and Characterization Analysis of Transient Receptor Potential Mucolipin Protein of Laodelphax striatellus Fallén. INSECTS 2021; 12:insects12121107. [PMID: 34940195 PMCID: PMC8706664 DOI: 10.3390/insects12121107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/08/2021] [Accepted: 12/11/2021] [Indexed: 12/29/2022]
Abstract
Transient receptor potential mucolipin (TRPML) protein in flies plays a pivotal role in Ca2+ ions release, resulting in membrane trafficking, autophagy and ion homeostasis. However, to date, the characterization of TRPML in agricultural pests remains unknown. Here, we firstly reported the TRPML of a destructive pest of gramineous crops, Laodelphax striatellus. The L. striatellus TRPML (Ls-TRPML) has a 1818 bp open reading frame, encoding 605 amino acid. TRPML in agricultural pests is evolutionarily conserved, and the expression of Ls-TRPML is predominately higher in the ovary than in other organs of L. striatellus at the transcript and protein level. The Bac-Bac system showed that Ls-TRPML localized in the plasma membrane, nuclear membrane and nucleus and co-localized with lysosome in Spodoptera frugiperda cells. The immunofluorescence microscopy analysis showed that Ls-TRPML localized in the cytoplasm and around the nuclei of the intestine cells or ovary follicular cells of L. striatellus. The results from the lipid-binding assay revealed that Ls-TRPML strongly bound to phosphatidylinositol-3,5-bisphosphate, as compared with other phosphoinositides. Overall, our results helped is identify and characterize the TRPML protein of L. striatellus, shedding light on the function of TRPML in multiple cellular processes in agricultural pests.
Collapse
Affiliation(s)
- Haitao Wang
- Key Laboratory of Food Quality and Safety of Jiangsu Province, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (Y.D.); (Y.J.)
- Correspondence: (H.W.); (Q.X.); Tel.: +86-134-5181-6249 (H.W.); +86-133-2781-7381 (Q.X.)
| | - Yan Dong
- Key Laboratory of Food Quality and Safety of Jiangsu Province, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (Y.D.); (Y.J.)
| | - Baijie Wan
- Institute of Agricultural Sciences in Jiangsu Coastal Area, Yancheng 224002, China;
| | - Yinghua Ji
- Key Laboratory of Food Quality and Safety of Jiangsu Province, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (Y.D.); (Y.J.)
| | - Qiufang Xu
- Key Laboratory of Food Quality and Safety of Jiangsu Province, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (Y.D.); (Y.J.)
- Institute of Life Sciences, Jiangsu University, Zhenjiang 212013, China
- Correspondence: (H.W.); (Q.X.); Tel.: +86-134-5181-6249 (H.W.); +86-133-2781-7381 (Q.X.)
| |
Collapse
|
5
|
DeRosa S, Salani M, Smith S, Sangster M, Miller-Browne V, Wassmer S, Xiao R, Vandenberghe L, Slaugenhaupt S, Misko A, Grishchuk Y. MCOLN1 gene therapy corrects neurologic dysfunction in the mouse model of mucolipidosis IV. Hum Mol Genet 2021; 30:908-922. [PMID: 33822942 DOI: 10.1093/hmg/ddab093] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 03/24/2021] [Accepted: 03/30/2021] [Indexed: 02/07/2023] Open
Abstract
Mucolipidosis IV (MLIV) is an orphan disease leading to debilitating psychomotor deficits and vision loss. It is caused by loss-of-function mutations in the MCOLN1 gene that encodes the lysosomal transient receptor potential channel mucolipin1, or TRPML1. With no existing therapy, the unmet need in this disease is very high. Here, we showed that AAV-mediated CNS-targeted gene transfer of the human MCOLN1 gene rescued motor function and alleviated brain pathology in the MLIV mouse model. Using the AAV-PHP.b vector in symptomatic mice, we showed long-term reversal of declined motor function and significant delay of paralysis. Next, using self-complementary AAV9 clinical candidate vector, we showed that its intracerebroventricular administration in post-natal day 1 mice significantly improved motor function, myelination and reduced lysosomal storage load in the MLIV mouse brain. Based on our data and general advancements in the gene therapy field, we propose scAAV9-mediated CSF-targeted MCOLN1 gene transfer as a therapeutic strategy in MLIV.
Collapse
Affiliation(s)
- Samantha DeRosa
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute/Harvard Medical School, Boston, MA 02114, USA
| | - Monica Salani
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute/Harvard Medical School, Boston, MA 02114, USA
| | - Sierra Smith
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute/Harvard Medical School, Boston, MA 02114, USA
| | - Madison Sangster
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute/Harvard Medical School, Boston, MA 02114, USA
| | - Victoria Miller-Browne
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute/Harvard Medical School, Boston, MA 02114, USA
| | - Sarah Wassmer
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary and Harvard Medical School, Boston, MA 02114, USA
| | - Ru Xiao
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary and Harvard Medical School, Boston, MA 02114, USA
| | - Luk Vandenberghe
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary and Harvard Medical School, Boston, MA 02114, USA
| | - Susan Slaugenhaupt
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute/Harvard Medical School, Boston, MA 02114, USA
| | - Albert Misko
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute/Harvard Medical School, Boston, MA 02114, USA
| | - Yulia Grishchuk
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute/Harvard Medical School, Boston, MA 02114, USA
| |
Collapse
|
6
|
Vardi A, Pri-Or A, Wigoda N, Grishchuk Y, Futerman AH. Proteomics analysis of a human brain sample from a mucolipidosis type IV patient reveals pathophysiological pathways. Orphanet J Rare Dis 2021; 16:39. [PMID: 33478506 PMCID: PMC7818904 DOI: 10.1186/s13023-021-01679-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 01/06/2021] [Indexed: 12/29/2022] Open
Abstract
Background Mucolipidosis type IV (MLIV), an ultra-rare neurodevelopmental and neurodegenerative disorder, is caused by mutations in the MCOLN1 gene, which encodes the late endosomal/lysosomal transient receptor potential channel TRPML1 (mucolipin 1). The precise pathophysiogical pathways that cause neurological disease in MLIV are poorly understood. Recently, the first post-mortem brain sample became available from a single MLIV patient, and in the current study we performed mass spectrometry (MS)-based proteomics on this tissue with a view to delineating pathological pathways, and to compare with previously-published data on MLIV, including studies using the Mcoln1−/− mouse. Results A number of pathways were altered in two brain regions from the MLIV patient, including those related to the lysosome, lipid metabolism, myelination, cellular trafficking and autophagy, mTOR and calmodulin, the complement system and interferon signaling. Of these, levels of some proteins not known previously to be associated with MLIV were altered, including APOD, PLIN4, ATG and proteins related to interferon signaling. Moreover, when proteins detected by proteomics in the human brain were compared with their orthologs detected in the Mcoln1−/− mouse by RNAseq, the results were remarkably similar. Finally, analysis of proteins in human and mouse CSF suggest that calbindin 1 and calbindin 2 might be useful as biomarkers to help chart the course of disease development. Conclusions Despite the sample size limitations, our findings are consistent with the relatively general changes in lysosomal function previously reported in MLIV, and shed light on new pathways of disease pathophysiology, which is required in order to understand the course of disease development and to determine the efficacy of therapies when they become available for this devastating disease.
Collapse
Affiliation(s)
- Ayelet Vardi
- Department of Biomolecular Sciences, Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Amir Pri-Or
- The Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Noa Wigoda
- The Life Sciences Core Facilities, Weizmann Institute of Science, 76100, Rehovot, Israel
| | - Yulia Grishchuk
- Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital Research Institute, Harvard Medical School, 185 Cambridge St., Boston, MA, 02114, USA
| | - Anthony H Futerman
- Department of Biomolecular Sciences, Weizmann Institute of Science, 76100, Rehovot, Israel.
| |
Collapse
|
7
|
Nourbakhsh F, Read MI, Barreto GE, Sahebkar A. Boosting the autophagy-lysosomal pathway by phytochemicals: A potential therapeutic strategy against Alzheimer's disease. IUBMB Life 2020; 72:2360-2281. [PMID: 32894821 DOI: 10.1002/iub.2369] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/20/2020] [Accepted: 07/31/2020] [Indexed: 01/14/2023]
Abstract
The lysosome is a membrane-enclosed organelle in eukaryotic cells, which has basic pattern recognition for nutrient-dependent signal transduction. In Alzheimer's disease, the already declining autophagy-lysosomal function is exacerbated by an increased need for clearance of damaged proteins and organelles in aged cells. Recent evidence suggests that numerous diseases are linked to impaired autophagy upstream of lysosomes. In this way, a comprehensive survey on the pathophysiology of the disease seems necessary. Hence, in the first section of this review, we will discuss the ultimate findings in lysosomal signaling functions and how they affect cellular metabolism and trafficking under neurodegenerative conditions, specifically Alzheimer's disease. In the second section, we focus on how natural products and their derivatives are involved in the regulation of inflammation and lysosomal dysfunction pathways, including how these should be considered a crucial target for Alzheimer's disease therapeutics.
Collapse
Affiliation(s)
- Fahimeh Nourbakhsh
- Medical Toxicology Research Centre, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Morgayn I Read
- Department of Pharmacology, University of Otago School of Medical Sciences, Dunedin, New Zealand
| | - George E Barreto
- Department of Biological Sciences, University of Limerick, Limerick, Ireland.,Health Research Institute, University of Limerick, Limerick, Ireland
| | - Amirhossein Sahebkar
- Halal Research Center of IRI, FDA, Tehran, Iran.,Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.,Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,Polish Mother's Memorial Hospital Research Institute (PMMHRI), Lodz, Poland
| |
Collapse
|
8
|
Abstract
Transient Receptor Potential (TRP) channels are evolutionarily conserved integral membrane proteins. The mammalian TRP superfamily of ion channels consists of 28 cation permeable channels that are grouped into six subfamilies based on sequence homology (Fig. 6.1). The canonical TRP (TRPC) subfamily is known for containing the founding member of mammalian TRP channels. The vanilloid TRP (TRPV) subfamily has been extensively studied due to the heat sensitivity of its founding member. The melastatin-related TRP (TRPM) subfamily includes some of the few known bi-functional ion channels, which contain functional enzymatic domains. The ankyrin TRP (TRPA) subfamily consists of a single chemo-nociceptor that has been proposed to be a target for analgesics. The mucolipin TRP (TRPML) subfamily channels are found primarily in intracellular compartments and were discovered based on their critical role in type IV mucolipidosis (ML-IV). The polycystic TRP (TRPP) subfamily is a diverse group of proteins implicated in autosomal dominant polycystic kidney disease (ADPKD). Overall, this superfamily of channels is involved in a vast array of physiological and pathophysiological processes making the study of these channels imperative to our understanding of subcellular biochemistry.
Collapse
Affiliation(s)
- Amrita Samanta
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
- Department of Physiology and Biophysics School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Taylor E T Hughes
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Vera Y Moiseenkova-Bell
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Department of Physiology and Biophysics School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
| |
Collapse
|
9
|
Weinstock LD, Furness AM, Herron SS, Smith SS, Sankar SB, DeRosa SG, Gao D, Mepyans ME, Scotto Rosato A, Medina DL, Vardi A, Ferreira NS, Cho SM, Futerman AH, Slaugenhaupt SA, Wood LB, Grishchuk Y. Fingolimod phosphate inhibits astrocyte inflammatory activity in mucolipidosis IV. Hum Mol Genet 2018; 27:2725-2738. [PMID: 29771310 PMCID: PMC6915831 DOI: 10.1093/hmg/ddy182] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 04/09/2018] [Accepted: 05/08/2018] [Indexed: 12/25/2022] Open
Abstract
Mucolipidosis IV (MLIV) is an orphan neurodevelopmental disease that causes severe neurologic dysfunction and loss of vision. Currently there is no therapy for MLIV. It is caused by loss of function of the lysosomal channel mucolipin-1, also known as TRPML1. Knockout of the Mcoln1 gene in a mouse model mirrors clinical and neuropathologic signs in humans. Using this model, we previously observed robust activation of microglia and astrocytes in early symptomatic stages of disease. Here we investigate the consequence of mucolipin-1 loss on astrocyte inflammatory activation in vivo and in vitro and apply a pharmacologic approach to restore Mcoln1-/- astrocyte homeostasis using a clinically approved immunomodulator, fingolimod. We found that Mcoln1-/- mice over-express numerous pro-inflammatory cytokines, some of which were also over-expressed in astrocyte cultures. Changes in the cytokine profile in Mcoln1-/- astrocytes are concomitant with changes in phospho-protein signaling, including activation of PI3K/Akt and MAPK pathways. Fingolimod promotes cytokine homeostasis, down-regulates signaling within the PI3K/Akt and MAPK pathways and restores the lysosomal compartment in Mcoln1-/- astrocytes. These data suggest that fingolimod is a promising candidate for preclinical evaluation in our MLIV mouse model, which, in case of success, can be rapidly translated into clinical trial.
Collapse
Affiliation(s)
- Laura D Weinstock
- George W. Woodruff School of Mechanical Engineering, Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory, Parker H. Petit Institute for Bioengineering & Bioscience, Georgia Institute of Technology, 315 Ferst Dr., Atlanta, GA, USA
| | - Amanda M Furness
- Department of Neurology, Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Harvard Medical School, 185 Cambridge St., Boston, MA, USA
| | - Shawn S Herron
- Department of Neurology, Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Harvard Medical School, 185 Cambridge St., Boston, MA, USA
| | - Sierra S Smith
- Department of Neurology, Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Harvard Medical School, 185 Cambridge St., Boston, MA, USA
| | - Sitara B Sankar
- George W. Woodruff School of Mechanical Engineering, Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory, Parker H. Petit Institute for Bioengineering & Bioscience, Georgia Institute of Technology, 315 Ferst Dr., Atlanta, GA, USA
| | - Samantha G DeRosa
- Department of Neurology, Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Harvard Medical School, 185 Cambridge St., Boston, MA, USA
| | - Dadi Gao
- Department of Neurology, Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Harvard Medical School, 185 Cambridge St., Boston, MA, USA
| | - Molly E Mepyans
- Department of Neurology, Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Harvard Medical School, 185 Cambridge St., Boston, MA, USA
| | - Anna Scotto Rosato
- Telethon Institute of Genetics and Medicine (TIGEM), via Campi Flegrei 34, Pozzuoli (NA), Italy
| | - Diego L Medina
- Telethon Institute of Genetics and Medicine (TIGEM), via Campi Flegrei 34, Pozzuoli (NA), Italy
| | - Ayelet Vardi
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Natalia S Ferreira
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Winterthurerstrasse 260, Zurich, Switzerland
| | - Soo Min Cho
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Anthony H Futerman
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Susan A Slaugenhaupt
- Department of Neurology, Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Harvard Medical School, 185 Cambridge St., Boston, MA, USA
| | - Levi B Wood
- George W. Woodruff School of Mechanical Engineering, Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory, Parker H. Petit Institute for Bioengineering & Bioscience, Georgia Institute of Technology, 315 Ferst Dr., Atlanta, GA, USA
| | - Yulia Grishchuk
- Department of Neurology, Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Harvard Medical School, 185 Cambridge St., Boston, MA, USA
| |
Collapse
|
10
|
Zhang S, Li N, Zeng W, Gao N, Yang M. Cryo-EM structures of the mammalian endo-lysosomal TRPML1 channel elucidate the combined regulation mechanism. Protein Cell 2017; 8:834-847. [PMID: 28936784 PMCID: PMC5676595 DOI: 10.1007/s13238-017-0476-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 09/18/2017] [Indexed: 01/10/2023] Open
Abstract
TRPML1 channel is a non-selective group-2 transient receptor potential (TRP) channel with Ca2+ permeability. Located mainly in late endosome and lysosome of all mammalian cell types, TRPML1 is indispensable in the processes of endocytosis, membrane trafficking, and lysosome biogenesis. Mutations of TRPML1 cause a severe lysosomal storage disorder called mucolipidosis type IV (MLIV). In the present study, we determined the cryo-electron microscopy (cryo-EM) structures of Mus musculus TRPML1 (mTRPML1) in lipid nanodiscs and Amphipols. Two distinct states of mTRPML1 in Amphipols are added to the closed state, on which could represent two different confirmations upon activation and regulation. The polycystin-mucolipin domain (PMD) may sense the luminal/extracellular stimuli and undergo a “move upward” motion during endocytosis, thus triggering the overall conformational change in TRPML1. Based on the structural comparisons, we propose TRPML1 is regulated by pH, Ca2+, and phosphoinositides in a combined manner so as to accommodate the dynamic endocytosis process.
Collapse
Affiliation(s)
- Sensen Zhang
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Ningning Li
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Science, Peking University, Beijing, 100871, China
| | - Wenwen Zeng
- Institute for Immunology and School of Medicine, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Science, Peking University, Beijing, 100871, China.
| | - Maojun Yang
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
| |
Collapse
|
11
|
Grishchuk Y, Peña KA, Coblentz J, King VE, Humphrey DM, Wang SL, Kiselyov KI, Slaugenhaupt SA. Impaired myelination and reduced brain ferric iron in the mouse model of mucolipidosis IV. Dis Model Mech 2015; 8:1591-601. [PMID: 26398942 PMCID: PMC4728313 DOI: 10.1242/dmm.021154] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 09/08/2015] [Indexed: 12/11/2022] Open
Abstract
Mucolipidosis type IV (MLIV) is a lysosomal storage disease caused by mutations in the MCOLN1 gene, which encodes the lysosomal transient receptor potential ion channel mucolipin-1 (TRPML1). MLIV causes impaired motor and cognitive development, progressive loss of vision and gastric achlorhydria. How loss of TRPML1 leads to severe psychomotor retardation is currently unknown, and there is no therapy for MLIV. White matter abnormalities and a hypoplastic corpus callosum are the major hallmarks of MLIV brain pathology. Here, we report that loss of TRPML1 in mice results in developmental aberrations of brain myelination as a result of deficient maturation and loss of oligodendrocytes. Defective myelination is evident in Mcoln1(-/-) mice at postnatal day 10, an active stage of postnatal myelination in the mouse brain. Expression of mature oligodendrocyte markers is reduced in Mcoln1(-/-) mice at postnatal day 10 and remains lower throughout the course of the disease. We observed reduced Perls' staining in Mcoln1(-/-) brain, indicating lower levels of ferric iron. Total iron content in unperfused brain is not significantly different between Mcoln1(-/-) and wild-type littermate mice, suggesting that the observed maturation delay or loss of oligodendrocytes might be caused by impaired iron handling, rather than by global iron deficiency. Overall, these data emphasize a developmental rather than a degenerative disease course in MLIV, and suggest that there should be a stronger focus on oligodendrocyte maturation and survival to better understand MLIV pathogenesis and aid treatment development.
Collapse
Affiliation(s)
- Yulia Grishchuk
- Center for Human Genetic Research and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 185 Cambridge Street, Boston, MA 02114, USA
| | - Karina A Peña
- Department of Biological Sciences, University of Pittsburgh, 519 Langley Hall, 4249 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Jessica Coblentz
- Department of Biological Sciences, University of Pittsburgh, 519 Langley Hall, 4249 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Victoria E King
- Center for Human Genetic Research and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 185 Cambridge Street, Boston, MA 02114, USA
| | - Daniel M Humphrey
- Center for Human Genetic Research and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 185 Cambridge Street, Boston, MA 02114, USA
| | - Shirley L Wang
- Center for Human Genetic Research and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 185 Cambridge Street, Boston, MA 02114, USA
| | - Kirill I Kiselyov
- Department of Biological Sciences, University of Pittsburgh, 519 Langley Hall, 4249 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Susan A Slaugenhaupt
- Center for Human Genetic Research and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 185 Cambridge Street, Boston, MA 02114, USA
| |
Collapse
|
12
|
Abstract
Lysosomes are acidic compartments filled with more than 60 different types of hydrolases. They mediate the degradation of extracellular particles from endocytosis and of intracellular components from autophagy. The digested products are transported out of the lysosome via specific catabolite exporters or via vesicular membrane trafficking. Lysosomes also contain more than 50 membrane proteins and are equipped with the machinery to sense nutrient availability, which determines the distribution, number, size, and activity of lysosomes to control the specificity of cargo flux and timing (the initiation and termination) of degradation. Defects in degradation, export, or trafficking result in lysosomal dysfunction and lysosomal storage diseases (LSDs). Lysosomal channels and transporters mediate ion flux across perimeter membranes to regulate lysosomal ion homeostasis, membrane potential, catabolite export, membrane trafficking, and nutrient sensing. Dysregulation of lysosomal channels underlies the pathogenesis of many LSDs and possibly that of metabolic and common neurodegenerative diseases.
Collapse
Affiliation(s)
- Haoxing Xu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109;
| | | |
Collapse
|
13
|
Evolutionary dynamics of metazoan TRP channels. Pflugers Arch 2015; 467:2043-53. [DOI: 10.1007/s00424-015-1705-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 03/19/2015] [Accepted: 03/19/2015] [Indexed: 10/23/2022]
|
14
|
Rigamonti M, Groppi S, Belotti F, Ambrosini R, Filippi G, Martegani E, Tisi R. Hypotonic stress-induced calcium signaling in Saccharomyces cerevisiae involves TRP-like transporters on the endoplasmic reticulum membrane. Cell Calcium 2015; 57:57-68. [DOI: 10.1016/j.ceca.2014.12.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 12/05/2014] [Accepted: 12/06/2014] [Indexed: 11/28/2022]
|
15
|
Grishchuk Y, Sri S, Rudinskiy N, Ma W, Stember KG, Cottle MW, Sapp E, Difiglia M, Muzikansky A, Betensky RA, Wong AMS, Bacskai BJ, Hyman BT, Kelleher RJ, Cooper JD, Slaugenhaupt SA. Behavioral deficits, early gliosis, dysmyelination and synaptic dysfunction in a mouse model of mucolipidosis IV. Acta Neuropathol Commun 2014; 2:133. [PMID: 25200117 PMCID: PMC4173007 DOI: 10.1186/s40478-014-0133-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 08/26/2014] [Indexed: 12/04/2022] Open
Abstract
Mucolipidosis IV (MLIV) is caused by mutations in the gene MCOLN1. Patients with MLIV have severe neurologic deficits and very little is known about the brain pathology in this lysosomal disease. Using an accurate mouse model of mucolipidosis IV, we observed early behavioral deficits which were accompanied by activation of microglia and astrocytes. The glial activation that persisted during the course of disease was not accompanied by neuronal loss even at the late stage. In vivo [Ca2+]-imaging revealed no changes in resting [Ca2+] levels in Mcoln1−/− cortical neurons, implying their physiological health. Despite the absence of neuron loss, we observed alterations in synaptic plasticity, as indicated by elevated paired-pulse facilitation and enhanced long-term potentiation. Myelination deficits and severely dysmorphic corpus callosum were present early and resembled white matter pathology in mucolipidosis IV patients. These results indicate the early involvement of glia, and challenge the traditional view of mucolipidosis IV as an overtly neurodegenerative condition.
Collapse
|
16
|
Peng G, Shi X, Kadowaki T. Evolution of TRP channels inferred by their classification in diverse animal species. Mol Phylogenet Evol 2014; 84:145-57. [PMID: 24981559 DOI: 10.1016/j.ympev.2014.06.016] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Revised: 06/05/2014] [Accepted: 06/17/2014] [Indexed: 12/11/2022]
Abstract
The functions of TRP channels have primarily been characterized in model organisms within a limited evolutionary context. We thus characterize the TRP channels in choanoflagellate, sponge, Cnidaria, Lophotrochozoa, and arthropods to understand how they emerged during early evolution of animals and have changed during diversification of various species. As previously reported, five metazoan TRP subfamily members (TRPA, TRPC, TRPM, TRPML, and TRPV) were identified in choanoflagellates, demonstrating that they evolved before the emergence of multicellular animals. TRPN was identified in Hydra magnipapillata, and therefore emerged in the last common ancestor of Cnidaria-Bilateria. A novel subfamily member (TRPVL) was identified in Cnidaria and Capitella teleta, indicating that it was present in the last common ancestor of Cnidaria-Bilateria but has since been lost in most bilaterians. The characterization of arthropod TRP channels revealed that Daphnia pulex and insects have specifically expanded the TRPA subfamily, which diverged from the ancient TRPA1 channel gene. The diversity of TRPA channels except TRPA1 was detectable even within a single insect family, namely the ant lineage. The present study demonstrates the evolutionary history of TRP channel genes, which may have diverged in conjunction with the specific habitats and life histories of individual species.
Collapse
Affiliation(s)
- Guangda Peng
- Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, 111 Ren'ai Road, Suzhou Dushu Lake Higher Education Town, Jiangsu Province 215123, China
| | - Xiao Shi
- Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, 111 Ren'ai Road, Suzhou Dushu Lake Higher Education Town, Jiangsu Province 215123, China
| | - Tatsuhiko Kadowaki
- Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, 111 Ren'ai Road, Suzhou Dushu Lake Higher Education Town, Jiangsu Province 215123, China.
| |
Collapse
|
17
|
Nilius B, Szallasi A. Transient Receptor Potential Channels as Drug Targets: From the Science of Basic Research to the Art of Medicine. Pharmacol Rev 2014; 66:676-814. [DOI: 10.1124/pr.113.008268] [Citation(s) in RCA: 348] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
|
18
|
Loss of TRPML1 promotes production of reactive oxygen species: is oxidative damage a factor in mucolipidosis type IV? Biochem J 2013; 457:361-8. [DOI: 10.1042/bj20130647] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
TRPML1 is a lysosomal ion channel permeable to cations, including Fe2+. Our data suggest that TRPML1 redistributes Fe2+ between the lysosomes and the cytoplasm. Loss of TRPML1 leads to production of reactive oxygen species, and to mitochondrial deterioration.
Collapse
|
19
|
Kukic I, Lee JK, Coblentz J, Kelleher SL, Kiselyov K. Zinc-dependent lysosomal enlargement in TRPML1-deficient cells involves MTF-1 transcription factor and ZnT4 (Slc30a4) transporter. Biochem J 2013; 451:155-63. [PMID: 23368743 PMCID: PMC3654546 DOI: 10.1042/bj20121506] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Zinc is critical for a multitude of cellular processes, including gene expression, secretion and enzymatic activities. Cellular zinc is controlled by zinc-chelating proteins and by zinc transporters. The recent identification of zinc permeability of the lysosomal ion channel TRPML1 (transient receptor potential mucolipin 1), and the evidence of abnormal zinc levels in cells deficient in TRPML1, suggested a role for TRPML1 in zinc transport. In the present study we provide new evidence for such a role and identify additional cellular components responsible for it. In agreement with the previously published data, an acute siRNA (small interfering RNA)-driven TRPML1 KD (knockdown) leads to the build-up of large cytoplasmic vesicles positive for LysoTracker™ and zinc staining, when cells are exposed to high concentrations of zinc. We now show that lysosomal enlargement and zinc build-up in TRPML1-KD cells exposed to zinc are ameliorated by KD of the zinc-sensitive transcription factor MTF-1 (metal-regulatory-element-binding transcription factor-1) or the zinc transporter ZnT4. TRPML1 KD is associated with a build-up of cytoplasmic zinc and with enhanced transcriptional response of mRNA for MT2a (metallothionein 2a). TRPML1 KD did not suppress lysosomal secretion, but it did delay zinc leak from the lysosomes into the cytoplasm. These results underscore a role for TRPML1 in zinc metabolism. Furthermore, they suggest that TRPML1 works in concert with ZnT4 to regulate zinc translocation between the cytoplasm and lysosomes.
Collapse
Affiliation(s)
- Ira Kukic
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jeffrey K. Lee
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jessica Coblentz
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Shannon L. Kelleher
- Departments of Nutrition, Surgery and Cell & Molecular Physiology, The Pennsylvania State University, State College, PA, USA
| | - Kirill Kiselyov
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| |
Collapse
|
20
|
Abstract
Described by the Belgian cytologist Christian De Duve in 1949,1 lysosomes (from the Greek “digestive bodies”) are ubiquitous specialized intracellular organelles that ensure the degradation/recycling of macromolecules (proteins, lipids, membranes) through the activity of specific enzymes (i.e., acid hydrolases). They receive their substrates through different internalization pathways (i.e., endocytosis, phagocytosis and autophagy) and are involved in a wide range of physiological functions from cell death and signaling to cholesterol homeostasis and plasma membrane repair.2 In Mammals, 50 soluble lysosomal hydrolases have been described, each targeting specific substrates. They are confined in the lumen of the lysosome and require an optimum pH (i.e., pH 4.5) to work. This acidic pH compared with the slightly alkaline pH of the cytosol (i.e., ~pH 7.2) is maintained by the activity of integral lysosomal membrane proteins (LMPs, that represent the second class of lysosomal proteins), including the V-type proton (H+)-ATPase3 and the chloride ion channel CLC74 that pumps protons from the cytosol across the lysosomal membrane.
Collapse
Affiliation(s)
- Norbert Weiss
- Hotchkiss Brain Institute; Department of Physiology and Pharmacology; University of Calgary; Calgary, AB Canada
| |
Collapse
|
21
|
Kiselyov KK, Ahuja M, Rybalchenko V, Patel S, Muallem S. The intracellular Ca²⁺ channels of membrane traffic. Channels (Austin) 2012; 6:344-51. [PMID: 22907062 DOI: 10.4161/chan.21723] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Regulation of organellar fusion and fission by Ca ( 2+) has emerged as a central paradigm in intracellular membrane traffic. Originally formulated for Ca ( 2+) -driven SNARE-mediated exocytosis in the presynaptic terminals, it was later expanded to explain membrane traffic in other exocytic events within the endo-lysosomal system. The list of processes and conditions that depend on the intracellular membrane traffic includes aging, antigen and lipid processing, growth factor signaling and enzyme secretion. Characterization of the ion channels that regulate intracellular membrane fusion and fission promises novel pharmacological approaches in these processes when their function becomes aberrant. The recent identification of Ca ( 2+) permeability through the intracellular ion channels comprising the mucolipin (TRPMLs) and the two-pore channels (TPCs) families pinpoints the candidates for the Ca ( 2+) channel that drive intracellular membrane traffic. The present review summarizes the recent developments and the current questions relevant to this topic.
Collapse
Affiliation(s)
- Kirill K Kiselyov
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | | | | | | | | |
Collapse
|
22
|
|
23
|
Invertebrate models of lysosomal storage disease: what have we learned so far? INVERTEBRATE NEUROSCIENCE 2011; 11:59-71. [PMID: 22038288 DOI: 10.1007/s10158-011-0125-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 10/08/2011] [Indexed: 01/17/2023]
Abstract
The lysosomal storage diseases (LSDs) collectively account for death in 1 in 8,000 children. Although some forms are treatable, they are essentially incurable and usually are lethal in the first decade of life. The most intractable forms of LSD are those with neuronal involvement. In an effort to identify the pathological signaling driving pathology in the LSDs, invertebrate models have been developed. In this review, we outline our current understanding of LSDs and recent findings using invertebrate models. We outline strategies and pitfalls for the development of such models. Available models of LSD in Drosophila and Caenorhabditis elegans are uncovering roles for LSD-related proteins with previously unknown function using both gain-of-function and loss-of-function strategies. These models of LSD in Drosophila and C. elegans have identified potential pathogenic signaling cascades that are proving critical to our understanding of these lethal diseases.
Collapse
|
24
|
Kiselyov K, Colletti GA, Terwilliger A, Ketchum K, Lyons CWP, Quinn J, Muallem S. TRPML: transporters of metals in lysosomes essential for cell survival? Cell Calcium 2011; 50:288-94. [PMID: 21621258 DOI: 10.1016/j.ceca.2011.04.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Accepted: 04/29/2011] [Indexed: 01/09/2023]
Abstract
Key aspects of lysosomal function are affected by the ionic content of the lysosomal lumen and, therefore, by the ion permeability in the lysosomal membrane. Such functions include regulation of lysosomal acidification, a critical process in delivery and activation of the lysosomal enzymes, release of metals from lysosomes into the cytoplasm and the Ca(2+)-dependent component of membrane fusion events in the endocytic pathway. While the basic mechanisms of lysosomal acidification have been largely defined, the lysosomal metal transport system is not well understood. TRPML1 is a lysosomal ion channel whose malfunction is implicated in the lysosomal storage disease Mucolipidosis Type IV. Recent evidence suggests that TRPML1 is involved in Fe(2+), Ca(2+) and Zn(2+) transport across the lysosomal membrane, ascribing novel physiological roles to this ion channel, and perhaps to its relatives TRPML2 and TRPML3 and illuminating poorly understood aspects of lysosomal function. Further, alterations in metal transport by the TRPMLs due to mutations or environmental factors may contribute to their role in the disease phenotype and cell death.
Collapse
Affiliation(s)
- Kirill Kiselyov
- Department of Biological Science, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| | | | | | | | | | | | | |
Collapse
|