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Karim MR, Gasparini E, Tiegs E, Schlichte R, Vermilyea SC, Lee MK. Internalized α-synuclein fibrils become truncated and resist degradation in neurons while glial cells rapidly degrade α-synuclein fibrils. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.05.597615. [PMID: 38895363 PMCID: PMC11185753 DOI: 10.1101/2024.06.05.597615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Parkinson's disease (PD) and other α-synucleinopathies are characterized by the accumulation of α-synuclein (αS) pathology that can spread via the cell-to-cell transmission of αS aggregates. To better understand how various brain cells contribute to the spreading of αS pathology, we examined the metabolism of αS aggreges or pre-formed fibrils (PFFs) in neuronal and glial cells (microglia, astrocytes, and oligodendrocytes). In neurons, while the full-length αS rapidly disappeared following αS PFF uptake, truncated αS accumulated with a half-life of days rather than hours. Epitope mapping and fractionation studies indicate that αS PFF was truncated at the C-terminal region following uptake and remained insoluble/aggregated. In contrast, microglia and astrocytes rapidly metabolized αS PFF as the half-lives of αS PFF in these glial cells were <6 hours. Differential processing of αS by neurons was recapitulated in cell lines as differentiated CLU neuronal cell lines stably accumulate truncated αS while undifferentiated cells rapidly metabolize αS. Immunolocalization and subcellular fractionation studies show that internalized αS PFF is initially localized to endosomes followed by lysosomes. The lysosome is largely responsible for the degradation of internalized αS PFF as the inhibition of lysosomal function leads to the stabilization of αS in all cell types. Significantly, αS PFF causes lysosomal dysfunction in neurons. In summary, we show that neurons are inefficient in metabolizing internalized αS aggregates, partially because αS aggregates cause lysosomal dysfunction, potentially generating aggregation-prone truncated αS. In contrast, glial cells may protect neurons from αS aggregates by rapidly clearing αS aggregates.
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Affiliation(s)
- Md. Razaul Karim
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD
| | - Emilie Gasparini
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
| | - Elizabeth Tiegs
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD
| | - Riley Schlichte
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD
| | - Scott C. Vermilyea
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD
| | - Michael K. Lee
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN 55414, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD
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Xu G, Peng H, Yao R, Yang Y, Li B. TFEB and TFE3 cooperate in regulating inorganic arsenic-induced autophagy-lysosome impairment and immuno-dysfunction in primary dendritic cells. Cell Biol Toxicol 2024; 40:4. [PMID: 38267572 PMCID: PMC10808261 DOI: 10.1007/s10565-024-09841-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 12/04/2023] [Indexed: 01/26/2024]
Abstract
Arsenic (As) is a prevalent and hazardous environmental toxicant associated with cancer and various health problems, which has been shown suppressive effects on dendritic cells (DCs). Autophagy is essential for the innate and adaptive immune responses of DCs, and the transcription factors TFEB and TFE3 are key regulators of autophagic and lysosomal target genes. However, the detrimental alterations of the autophagy-lysosome pathway in As-exposed DCs and the possible coordinating roles of TFEB and TFE3 in the immune dysfunction of this cell are less understood. In this paper, we found that As exposure significantly impaired lysosomal number, lysosomal acidic environment, and lysosomal membrane permeabilization, which might lead to blocked autophagic flux in cultured DCs. Furthermore, our results confirmed that TFEB or TFE3 knockdown exacerbated the disorders of lysosome and the blockade of autophagic flux in As-exposed DCs, and also enhanced the inhibitory expression of co-stimulatory molecules Cd80 and Cd83; adhesion molecule Icam1; cytokines TNF-α, IL-1β, and IL-6; chemokine receptor Ccr7; and antigen-presenting molecules MHC II and MHC I. By contrast, overexpression of TFEB or TFE3 partially alleviated the above-mentioned impairment of DCs by inorganic As exposure. In conclusion, these findings reveal a previously unappreciated inhibition of lysosome-mediated degradation and damage of lysosomal membrane integrity leading to dysregulated autophagy and impaired immune functions of DCs by arsenicals, and also suggest TFEB and TFE3 as potential therapeutic targets for ameliorating As toxicity.
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Affiliation(s)
- Guowei Xu
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education (China Medical University), Shenyang, Liaoning, People's Republic of China
- Environment and Non-Communicable Disease Research Center, Key Laboratory of Arsenic-Related Biological Effects and Prevention and Treatment in Liaoning Province, School of Public Health, China Medical University, No.77 Puhe Road, Shenyang North New Area Liaoning Province, Shenyang, 110122, People's Republic of China
| | - Huaguang Peng
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education (China Medical University), Shenyang, Liaoning, People's Republic of China
- Environment and Non-Communicable Disease Research Center, Key Laboratory of Arsenic-Related Biological Effects and Prevention and Treatment in Liaoning Province, School of Public Health, China Medical University, No.77 Puhe Road, Shenyang North New Area Liaoning Province, Shenyang, 110122, People's Republic of China
| | - Ran Yao
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education (China Medical University), Shenyang, Liaoning, People's Republic of China
- Environment and Non-Communicable Disease Research Center, Key Laboratory of Arsenic-Related Biological Effects and Prevention and Treatment in Liaoning Province, School of Public Health, China Medical University, No.77 Puhe Road, Shenyang North New Area Liaoning Province, Shenyang, 110122, People's Republic of China
| | - Yuqing Yang
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education (China Medical University), Shenyang, Liaoning, People's Republic of China
- Environment and Non-Communicable Disease Research Center, Key Laboratory of Arsenic-Related Biological Effects and Prevention and Treatment in Liaoning Province, School of Public Health, China Medical University, No.77 Puhe Road, Shenyang North New Area Liaoning Province, Shenyang, 110122, People's Republic of China
| | - Bing Li
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education (China Medical University), Shenyang, Liaoning, People's Republic of China.
- Environment and Non-Communicable Disease Research Center, Key Laboratory of Arsenic-Related Biological Effects and Prevention and Treatment in Liaoning Province, School of Public Health, China Medical University, No.77 Puhe Road, Shenyang North New Area Liaoning Province, Shenyang, 110122, People's Republic of China.
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Nakamura H, Tanaka T, Zheng C, Afione SA, Warner BM, Noguchi M, Atsumi T, Chiorini JA. Lysosome-Associated Membrane Protein 3 Induces Lysosome-Dependent Cell Death by Impairing Autophagic Caspase 8 Degradation in the Salivary Glands of Individuals With Sjögren's Disease. Arthritis Rheumatol 2023; 75:1586-1598. [PMID: 37096570 PMCID: PMC11132095 DOI: 10.1002/art.42540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 03/03/2023] [Accepted: 04/10/2023] [Indexed: 04/26/2023]
Abstract
OBJECTIVE Lysosome-associated membrane protein 3 (LAMP3) overexpression is implicated in the development and progression of Sjögren's disease (SjD) by inducing lysosomal membrane permeabilization (LMP) and apoptotic cell death in salivary gland epithelium. The aim of this study was to clarify the molecular details of LAMP3-induced lysosome-dependent cell death and to test lysosomal biogenesis as a therapeutic intervention. METHODS Human labial minor salivary gland biopsies were analyzed using immunofluorescence staining for LAMP3 expression levels and galectin-3 puncta formation, a marker of LMP. Expression level of caspase 8, an initiator of LMP, was determined by Western blotting in cell culture. Galectin-3 puncta formation and apoptosis were evaluated in cell cultures and a mouse model treated with glucagon-like peptide 1 receptor (GLP-1R) agonists, a known promoter of lysosomal biogenesis. RESULTS Galectin-3 puncta formation was more frequent in the salivary glands of SjD patients compared to control glands. The proportion of galectin-3 puncta-positive cells was positively correlated with LAMP3 expression levels in the glands. LAMP3 overexpression increased caspase 8 expression, and knockdown of caspase 8 decreased galectin-3 puncta formation and apoptosis in LAMP3-overexpressing cells. Inhibition of autophagy increased caspase 8 expression, while restoration of lysosomal function using GLP-1R agonists decreased caspase 8 expression, which reduced galectin-3 puncta formation and apoptosis in both LAMP3-overexpressing cells and mice. CONCLUSION LAMP3 overexpression induced lysosomal dysfunction, resulting in lysosome-dependent cell death via impaired autophagic caspase 8 degradation, and restoring lysosomal function using GLP-1R agonists could prevent this. These findings suggested that LAMP3-induced lysosomal dysfunction is central to disease development and is a target for therapeutic intervention in SjD.
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Affiliation(s)
- Hiroyuki Nakamura
- Adeno-Associated Virus Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Tsutomu Tanaka
- Adeno-Associated Virus Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Changyu Zheng
- Adeno-Associated Virus Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Sandra A Afione
- Adeno-Associated Virus Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Blake M. Warner
- Salivary Disorder Unit, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Masayuki Noguchi
- Division of Cancer Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
| | - Tatsuya Atsumi
- Department of Rheumatology, Endocrinology and Nephrology, Faculty of Medicine, Hokkaido University, Sapporo, Japan
| | - John A. Chiorini
- Adeno-Associated Virus Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
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Bierschenk D, Papac-Milicevic N, Bresch IP, Kovacic V, Bettoni S, Dziedzic M, Wetsel RA, Eschenburg S, Binder CJ, Blom AM, King BC. C4b-binding protein inhibits particulate- and crystalline-induced NLRP3 inflammasome activation. Front Immunol 2023; 14:1149822. [PMID: 37283747 PMCID: PMC10239802 DOI: 10.3389/fimmu.2023.1149822] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 05/05/2023] [Indexed: 06/08/2023] Open
Abstract
Dysregulated NLRP3 inflammasome activation drives a wide variety of diseases, while endogenous inhibition of this pathway is poorly characterised. The serum protein C4b-binding protein (C4BP) is a well-established inhibitor of complement with emerging functions as an endogenously expressed inhibitor of the NLRP3 inflammasome signalling pathway. Here, we identified that C4BP purified from human plasma is an inhibitor of crystalline- (monosodium urate, MSU) and particulate-induced (silica) NLRP3 inflammasome activation. Using a C4BP mutant panel, we identified that C4BP bound these particles via specific protein domains located on the C4BP α-chain. Plasma-purified C4BP was internalised into MSU- or silica-stimulated human primary macrophages, and inhibited MSU- or silica-induced inflammasome complex assembly and IL-1β cytokine secretion. While internalised C4BP in MSU or silica-stimulated human macrophages was in close proximity to the inflammasome adaptor protein ASC, C4BP had no direct effect on ASC polymerisation in in vitro assays. C4BP was also protective against MSU- and silica-induced lysosomal membrane damage. We further provide evidence for an anti-inflammatory function for C4BP in vivo, as C4bp-/- mice showed an elevated pro-inflammatory state following intraperitoneal delivery of MSU. Therefore, internalised C4BP is an inhibitor of crystal- or particle-induced inflammasome responses in human primary macrophages, while murine C4BP protects against an enhanced inflammatory state in vivo. Our data suggests C4BP has important functions in retaining tissue homeostasis in both human and mice as an endogenous serum inhibitor of particulate-stimulated inflammasome activation.
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Affiliation(s)
- Damien Bierschenk
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, Malmö, Sweden
| | | | - Ian P. Bresch
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Valentina Kovacic
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Serena Bettoni
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Mateusz Dziedzic
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Rick A. Wetsel
- Research Center for Immunology and Autoimmune Diseases, Brown Foundation Institute of Molecular Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Susanne Eschenburg
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Christoph J. Binder
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Anna M. Blom
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Ben C. King
- Division of Medical Protein Chemistry, Department of Translational Medicine, Lund University, Malmö, Sweden
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5
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Carbó JM, Cornet-Masana JM, Cuesta-Casanovas L, Delgado-Martínez J, Banús-Mulet A, Clément-Demange L, Serra C, Catena J, Llebaria A, Esteve J, Risueño RM. A Novel Family of Lysosomotropic Tetracyclic Compounds for Treating Leukemia. Cancers (Basel) 2023; 15:cancers15061912. [PMID: 36980800 PMCID: PMC10047683 DOI: 10.3390/cancers15061912] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 03/13/2023] [Accepted: 03/20/2023] [Indexed: 03/30/2023] Open
Abstract
Acute myeloid leukemia (AML) is a heterogeneous hematological cancer characterized by poor prognosis and frequent relapses. Aside from specific mutation-related changes, in AML, the overall function of lysosomes and mitochondria is drastically altered to fulfill the elevated biomass and bioenergetic demands. On the basis of previous results, in silico drug discovery screening was used to identify a new family of lysosome-/mitochondria-targeting compounds. These novel tetracyclic hits, with a cationic amphiphilic structure, specifically eradicate leukemic cells by inducing both mitochondrial damage and apoptosis, and simultaneous lysosomal membrane leakiness. Lysosomal leakiness does not only elicit canonical lysosome-dependent cell death, but also activates the terminal differentiation of AML cells through the Ca2+-TFEB-MYC signaling axis. In addition to being an effective monotherapy, its combination with the chemotherapeutic arsenic trioxide (ATO) used in other types of leukemia is highly synergistic in AML cells, widening the therapeutic window of the treatment. Moreover, the compounds are effective in a wide panel of cancer cell lines and possess adequate pharmacological properties rendering them promising drug candidates for the treatment of AML and other neoplasias.
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Affiliation(s)
- José M Carbó
- Josep Carreras Leukaemia Research Institute (IJC), 08916 Barcelona, Spain
- Leukos Biotech, 08021 Barcelona, Spain
| | | | - Laia Cuesta-Casanovas
- Josep Carreras Leukaemia Research Institute (IJC), 08916 Barcelona, Spain
- Faculty of Biosciences, Autonomous University of Barcelona, 08193 Barcelona, Spain
| | - Jennifer Delgado-Martínez
- Josep Carreras Leukaemia Research Institute (IJC), 08916 Barcelona, Spain
- Faculty of Pharmacy, University of Barcelona, 08028 Barcelona, Spain
| | | | | | - Carme Serra
- MCS, Laboratory of Medicinal Chemistry and Synthesis, Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), 08034 Barcelona, Spain
- SIMChem, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), 08034 Barcelona, Spain
| | - Juanlo Catena
- MCS, Laboratory of Medicinal Chemistry and Synthesis, Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), 08034 Barcelona, Spain
- SIMChem, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), 08034 Barcelona, Spain
| | - Amadeu Llebaria
- MCS, Laboratory of Medicinal Chemistry and Synthesis, Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), 08034 Barcelona, Spain
| | - Jordi Esteve
- Josep Carreras Leukaemia Research Institute (IJC), 08916 Barcelona, Spain
- Department of Hematology, Hospital Clínic, 08036 Barcelona, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Ruth M Risueño
- Josep Carreras Leukaemia Research Institute (IJC), 08916 Barcelona, Spain
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Feng L, Liang L, Zhang S, Yang J, Yue Y, Zhang X. HMGB1 downregulation in retinal pigment epithelial cells protects against diabetic retinopathy through the autophagy-lysosome pathway. Autophagy 2021; 18:320-339. [PMID: 34024230 PMCID: PMC8942416 DOI: 10.1080/15548627.2021.1926655] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Diabetic retinopathy (DR) is a serious complication of diabetes mellitus and currently one of the major causes of blindness. Several previous studies have demonstrated that autophagy, which is regulated by HMGB1 (high mobility group box 1), is involved in DR development. However, the role of autophagy in DR is quite complicated in that it promotes pericyte survival in early DR, whereas excessive autophagy causes excess stress and leads to necrosis. Therefore, this study aimed to investigate the relationship between HMGB1, the macroautophagy/autophagy-lysosome pathway, and DR, as well as their underlying molecular mechanisms. In brief, the relationship between high glucose (HG) and the autophagy-lysosome pathway was examined in retinal pigment epithelial (RPE) cells. The relationship was studied by detecting classical autophagic features, and siRNAs targeting HMGB1 and pharmacological regulators were used to explore the role of the autophagy-lysosome pathway in DR development. The results demonstrated that HG inhibited autophagy and diminished the degradative capacity of autophagy due to lysosome membrane permeabilization (LMP). In addition, HMGB1 was found to be involved in LMP via the CTSB (cathepsin B)-dependent pathway, but not the CTSL (cathepsin L)-dependent pathway. Knockdown of HMGB1 expression rescued LMP, restored the degradative capacity of autophagy, decreased the expression of inflammatory factors and VEGF (vascular endothelial growth factor), and protected against apoptosis in RPE cells in the early stages of DR.
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Affiliation(s)
- Lujia Feng
- Chongqing Key Lab of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, P. R. China
| | - Liang Liang
- Chongqing Key Lab of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, P. R. China
| | - Shaochong Zhang
- Shenzhen Key Laboratory of Ophthalmology, Ophthalmology, Shenzhen Eye Hospital, Shenzhen, Guangdong, China
| | - Jinglu Yang
- Chongqing Key Lab of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, P. R. China
| | - Yanan Yue
- Chongqing Key Lab of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, P. R. China
| | - Xuedong Zhang
- Chongqing Key Lab of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Eye Institute, Chongqing Branch of National Clinical Research Center for Ocular Diseases, Chongqing, P. R. China
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7
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Hu M, Carraway KL. Repurposing Cationic Amphiphilic Drugs and Derivatives to Engage Lysosomal Cell Death in Cancer Treatment. Front Oncol 2020; 10:605361. [PMID: 33425762 PMCID: PMC7793984 DOI: 10.3389/fonc.2020.605361] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 11/13/2020] [Indexed: 12/22/2022] Open
Abstract
A major confounding issue in the successful treatment of cancer is the existence of tumor cell populations that resist therapeutic agents and regimens. While tremendous effort has gone into understanding the biochemical mechanisms underlying resistance to each traditional and targeted therapeutic, a broader approach to the problem may emerge from the recognition that existing anti-cancer agents elicit their cytotoxic effects almost exclusively through apoptosis. Considering the myriad mechanisms cancer cells employ to subvert apoptotic death, an attractive alternative approach would leverage programmed necrotic mechanisms to side-step therapeutic resistance to apoptosis-inducing agents. Lysosomal cell death (LCD) is a programmed necrotic cell death mechanism that is engaged upon the compromise of the limiting membrane of the lysosome, a process called lysosomal membrane permeabilization (LMP). The release of lysosomal components into the cytosol upon LMP triggers biochemical cascades that lead to plasma membrane rupture and necrotic cell death. Interestingly, the process of cellular transformation appears to render the limiting lysosomal membranes of tumor cells more fragile than non-transformed cells, offering a potential therapeutic window for drug development. Here we outline the concepts of LMP and LCD, and discuss strategies for the development of agents to engage these processes. Importantly, the potential exists for existing cationic amphiphilic drugs such as antidepressants, antibiotics, antiarrhythmics, and diuretics to be repurposed to engage LCD within therapy-resistant tumor cell populations.
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Affiliation(s)
- Michelle Hu
- Department of Biochemistry and Molecular Medicine, UC Davis School of Medicine, Sacramento, CA, United States
- UC Davis Comprehensive Cancer Center, UC Davis School of Medicine, Sacramento, CA, United States
| | - Kermit L. Carraway
- Department of Biochemistry and Molecular Medicine, UC Davis School of Medicine, Sacramento, CA, United States
- UC Davis Comprehensive Cancer Center, UC Davis School of Medicine, Sacramento, CA, United States
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