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Sanchez S, McDowell-Sanchez AK, Al-Meerani SB, Cala-Garcia JD, Waich Cohen AR, Ochsner SA, McKenna NJ, Celada LJ, Wu M, Assassi S, Rosas IO, Tsoyi K. PIK-III exerts anti-fibrotic effects in activated fibroblasts by regulating p38 activation. PLoS One 2024; 19:e0306624. [PMID: 39240940 PMCID: PMC11379285 DOI: 10.1371/journal.pone.0306624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 06/20/2024] [Indexed: 09/08/2024] Open
Abstract
Systemic sclerosis (SSc), also known as scleroderma, is an autoimmune-driven connective tissue disorder that results in fibrosis of the skin and internal organs such as the lung. Fibroblasts are known as the main effector cells involved in the progression of SSc through the induction of extracellular matrix (ECM) proteins and myofibroblast differentiation. Here, we demonstrate that 4'-(cyclopropylmethyl)-N2-4-pyridinyl-[4,5'-bipyrimidine]-2,2'-diamine (PIK-III), known as class III phosphatidylinositol 3-kinase (PIK3C3/VPS34) inhibitor, exerts potent antifibrotic effects in human dermal fibroblasts (HDFs) by attenuating transforming growth factor-beta 1 (TGF-β1)-induced ECM expression, cell contraction and myofibroblast differentiation. Unexpectedly, neither genetic silencing of PIK3C3 nor other PIK3C3 inhibitors (e.g., SAR405 and Autophinib) were able to mimic PIK-III-mediated antifibrotic effect in dermal fibroblasts, suggesting that PIK-III inhibits fibroblast activation through another signaling pathway. We identified that PIK-III effectively inhibits p38 activation in TGF-β1-stimulated dermal fibroblasts. Finally, PIK-III administration significantly attenuated dermal and lung fibrosis in bleomycin-injured mice.
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Affiliation(s)
- Santiago Sanchez
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Baylor College of Medicine, Houston, TX, United States of America
| | - Aaron K McDowell-Sanchez
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Baylor College of Medicine, Houston, TX, United States of America
| | - Sharaz B Al-Meerani
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Baylor College of Medicine, Houston, TX, United States of America
| | - Juan D Cala-Garcia
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Baylor College of Medicine, Houston, TX, United States of America
| | - Alan R Waich Cohen
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Baylor College of Medicine, Houston, TX, United States of America
| | - Scott A Ochsner
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, United States of America
| | - Neil J McKenna
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, United States of America
| | - Lindsay J Celada
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Baylor College of Medicine, Houston, TX, United States of America
| | - Minghua Wu
- Division of Rheumatology, University of Texas Health Science Center at Houston, McGovern Medical School, Houston, TX, United States of America
| | - Shervin Assassi
- Division of Rheumatology, University of Texas Health Science Center at Houston, McGovern Medical School, Houston, TX, United States of America
| | - Ivan O Rosas
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Baylor College of Medicine, Houston, TX, United States of America
| | - Konstantin Tsoyi
- Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, Baylor College of Medicine, Houston, TX, United States of America
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Schmid M, Fischer P, Engl M, Widder J, Kerschbaum-Gruber S, Slade D. The interplay between autophagy and cGAS-STING signaling and its implications for cancer. Front Immunol 2024; 15:1356369. [PMID: 38660307 PMCID: PMC11039819 DOI: 10.3389/fimmu.2024.1356369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 03/26/2024] [Indexed: 04/26/2024] Open
Abstract
Autophagy is an intracellular process that targets various cargos for degradation, including members of the cGAS-STING signaling cascade. cGAS-STING senses cytosolic double-stranded DNA and triggers an innate immune response through type I interferons. Emerging evidence suggests that autophagy plays a crucial role in regulating and fine-tuning cGAS-STING signaling. Reciprocally, cGAS-STING pathway members can actively induce canonical as well as various non-canonical forms of autophagy, establishing a regulatory network of feedback mechanisms that alter both the cGAS-STING and the autophagic pathway. The crosstalk between autophagy and the cGAS-STING pathway impacts a wide variety of cellular processes such as protection against pathogenic infections as well as signaling in neurodegenerative disease, autoinflammatory disease and cancer. Here we provide a comprehensive overview of the mechanisms involved in autophagy and cGAS-STING signaling, with a specific focus on the interactions between the two pathways and their importance for cancer.
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Affiliation(s)
- Maximilian Schmid
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
- Department of Medical Biochemistry, Medical University of Vienna, Max Perutz Labs, Vienna Biocenter, Vienna, Austria
| | - Patrick Fischer
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
- Department of Medical Biochemistry, Medical University of Vienna, Max Perutz Labs, Vienna Biocenter, Vienna, Austria
| | - Magdalena Engl
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
- Department of Medical Biochemistry, Medical University of Vienna, Max Perutz Labs, Vienna Biocenter, Vienna, Austria
- Vienna Biocenter PhD Program, a Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Joachim Widder
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Sylvia Kerschbaum-Gruber
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
| | - Dea Slade
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
- Department of Medical Biochemistry, Medical University of Vienna, Max Perutz Labs, Vienna Biocenter, Vienna, Austria
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3
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Salloum G, Bresnick AR, Backer JM. Macropinocytosis: mechanisms and regulation. Biochem J 2023; 480:335-362. [PMID: 36920093 DOI: 10.1042/bcj20210584] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/22/2023] [Accepted: 02/27/2023] [Indexed: 03/16/2023]
Abstract
Macropinocytosis is defined as an actin-dependent but coat- and dynamin-independent endocytic uptake process, which generates large intracellular vesicles (macropinosomes) containing a non-selective sampling of extracellular fluid. Macropinocytosis provides an important mechanism of immune surveillance by dendritic cells and macrophages, but also serves as an essential nutrient uptake pathway for unicellular organisms and tumor cells. This review examines the cell biological mechanisms that drive macropinocytosis, as well as the complex signaling pathways - GTPases, lipid and protein kinases and phosphatases, and actin regulatory proteins - that regulate macropinosome formation, internalization, and disposition.
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Affiliation(s)
- Gilbert Salloum
- Department of Molecular Pharamacology, Albert Einstein College of Medicine, Bronx, NY, U.S.A
| | - Anne R Bresnick
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, U.S.A
| | - Jonathan M Backer
- Department of Molecular Pharamacology, Albert Einstein College of Medicine, Bronx, NY, U.S.A
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, U.S.A
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4
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Hosios AM, Wilkinson ME, McNamara MC, Kalafut KC, Torrence ME, Asara JM, Manning BD. mTORC1 regulates a lysosome-dependent adaptive shift in intracellular lipid species. Nat Metab 2022; 4:1792-1811. [PMID: 36536136 PMCID: PMC9799240 DOI: 10.1038/s42255-022-00706-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 11/03/2022] [Indexed: 12/24/2022]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) senses and relays environmental signals from growth factors and nutrients to metabolic networks and adaptive cellular systems to control the synthesis and breakdown of macromolecules; however, beyond inducing de novo lipid synthesis, the role of mTORC1 in controlling cellular lipid content remains poorly understood. Here we show that inhibition of mTORC1 via small molecule inhibitors or nutrient deprivation leads to the accumulation of intracellular triglycerides in both cultured cells and a mouse tumor model. The elevated triglyceride pool following mTORC1 inhibition stems from the lysosome-dependent, but autophagy-independent, hydrolysis of phospholipid fatty acids. The liberated fatty acids are available for either triglyceride synthesis or β-oxidation. Distinct from the established role of mTORC1 activation in promoting de novo lipid synthesis, our data indicate that mTORC1 inhibition triggers membrane phospholipid trafficking to the lysosome for catabolism and an adaptive shift in the use of constituent fatty acids for storage or energy production.
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Affiliation(s)
- Aaron M Hosios
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Meghan E Wilkinson
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Molly C McNamara
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Krystle C Kalafut
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Margaret E Torrence
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - John M Asara
- Mass Spectrometry Core, Beth Israel Deaconess Medical Center, Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Brendan D Manning
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
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5
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Gillson J, Abd El-Aziz YS, Leck LYW, Jansson PJ, Pavlakis N, Samra JS, Mittal A, Sahni S. Autophagy: A Key Player in Pancreatic Cancer Progression and a Potential Drug Target. Cancers (Basel) 2022; 14:3528. [PMID: 35884592 PMCID: PMC9315706 DOI: 10.3390/cancers14143528] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 07/10/2022] [Accepted: 07/11/2022] [Indexed: 01/18/2023] Open
Abstract
Pancreatic cancer is known to have the lowest survival outcomes among all major cancers, and unfortunately, this has only been marginally improved over last four decades. The innate characteristics of pancreatic cancer include an aggressive and fast-growing nature from powerful driver mutations, a highly defensive tumor microenvironment and the upregulation of advantageous survival pathways such as autophagy. Autophagy involves targeted degradation of proteins and organelles to provide a secondary source of cellular supplies to maintain cell growth. Elevated autophagic activity in pancreatic cancer is recognized as a major survival pathway as it provides a plethora of support for tumors by supplying vital resources, maintaining tumour survival under the stressful microenvironment and promoting other pathways involved in tumour progression and metastasis. The combination of these features is unique to pancreatic cancer and present significant resistance to chemotherapeutic strategies, thus, indicating a need for further investigation into therapies targeting this crucial pathway. This review will outline the autophagy pathway and its regulation, in addition to the genetic landscape and tumor microenvironment that contribute to pancreatic cancer severity. Moreover, this review will also discuss the mechanisms of novel therapeutic strategies that inhibit autophagy and how they could be used to suppress tumor progression.
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Affiliation(s)
- Josef Gillson
- Faculty of Medicine and Health, University of Sydney, Camperdown, Sydney, NSW 2050, Australia; (J.G.); (Y.S.A.E.-A.); (L.Y.W.L.); (P.J.J.); (N.P.); (J.S.S.); (A.M.)
- Bill Walsh Translational Cancer Research Laboratory, Kolling Institute of Medical Research, St Leonards, Sydney, NSW 2065, Australia
| | - Yomna S. Abd El-Aziz
- Faculty of Medicine and Health, University of Sydney, Camperdown, Sydney, NSW 2050, Australia; (J.G.); (Y.S.A.E.-A.); (L.Y.W.L.); (P.J.J.); (N.P.); (J.S.S.); (A.M.)
- Bill Walsh Translational Cancer Research Laboratory, Kolling Institute of Medical Research, St Leonards, Sydney, NSW 2065, Australia
- Oral Pathology Department, Faculty of Dentistry, Tanta University, Tanta 31527, Egypt
| | - Lionel Y. W. Leck
- Faculty of Medicine and Health, University of Sydney, Camperdown, Sydney, NSW 2050, Australia; (J.G.); (Y.S.A.E.-A.); (L.Y.W.L.); (P.J.J.); (N.P.); (J.S.S.); (A.M.)
- Bill Walsh Translational Cancer Research Laboratory, Kolling Institute of Medical Research, St Leonards, Sydney, NSW 2065, Australia
- Cancer Drug Resistance and Stem Cell Program, University of Sydney, Sydney, NSW 2006, Australia
| | - Patric J. Jansson
- Faculty of Medicine and Health, University of Sydney, Camperdown, Sydney, NSW 2050, Australia; (J.G.); (Y.S.A.E.-A.); (L.Y.W.L.); (P.J.J.); (N.P.); (J.S.S.); (A.M.)
- Bill Walsh Translational Cancer Research Laboratory, Kolling Institute of Medical Research, St Leonards, Sydney, NSW 2065, Australia
- Cancer Drug Resistance and Stem Cell Program, University of Sydney, Sydney, NSW 2006, Australia
| | - Nick Pavlakis
- Faculty of Medicine and Health, University of Sydney, Camperdown, Sydney, NSW 2050, Australia; (J.G.); (Y.S.A.E.-A.); (L.Y.W.L.); (P.J.J.); (N.P.); (J.S.S.); (A.M.)
- Bill Walsh Translational Cancer Research Laboratory, Kolling Institute of Medical Research, St Leonards, Sydney, NSW 2065, Australia
| | - Jaswinder S. Samra
- Faculty of Medicine and Health, University of Sydney, Camperdown, Sydney, NSW 2050, Australia; (J.G.); (Y.S.A.E.-A.); (L.Y.W.L.); (P.J.J.); (N.P.); (J.S.S.); (A.M.)
- Upper GI Surgical Unit, Royal North Shore Hospital and North Shore Private Hospital, St Leonards, Sydney, NSW 2065, Australia
- Australian Pancreatic Centre, St Leonards, Sydney, NSW 2065, Australia
| | - Anubhav Mittal
- Faculty of Medicine and Health, University of Sydney, Camperdown, Sydney, NSW 2050, Australia; (J.G.); (Y.S.A.E.-A.); (L.Y.W.L.); (P.J.J.); (N.P.); (J.S.S.); (A.M.)
- Upper GI Surgical Unit, Royal North Shore Hospital and North Shore Private Hospital, St Leonards, Sydney, NSW 2065, Australia
- Australian Pancreatic Centre, St Leonards, Sydney, NSW 2065, Australia
- School of Medicine, University of Notre Dame, Darlinghurst, Sydney, NSW 2010, Australia
| | - Sumit Sahni
- Faculty of Medicine and Health, University of Sydney, Camperdown, Sydney, NSW 2050, Australia; (J.G.); (Y.S.A.E.-A.); (L.Y.W.L.); (P.J.J.); (N.P.); (J.S.S.); (A.M.)
- Bill Walsh Translational Cancer Research Laboratory, Kolling Institute of Medical Research, St Leonards, Sydney, NSW 2065, Australia
- Australian Pancreatic Centre, St Leonards, Sydney, NSW 2065, Australia
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6
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Stempels FC, Janssens MH, Ter Beest M, Mesman RJ, Revelo NH, Ioannidis M, van den Bogaart G. Novel and conventional inhibitors of canonical autophagy differently affect LC3-associated phagocytosis. FEBS Lett 2022; 596:491-509. [PMID: 35007347 DOI: 10.1002/1873-3468.14280] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 12/06/2021] [Accepted: 12/23/2021] [Indexed: 11/09/2022]
Abstract
In autophagy, LC3-positive autophagophores fuse and encapsulate the autophagic cargo in a double-membrane structure. In contrast, lipidated LC3 (LC3-II) is directly formed at the phagosomal membrane in LC3-associated phagocytosis (LAP). In this study, we dissected the effects of autophagy inhibitors on LAP. SAR405, an inhibitor of VPS34, reduced levels of LC3-II and inhibited LAP. In contrast, the inhibitors of endosomal acidification bafilomycin A1 and chloroquine increased levels of LC3-II, due to reduced degradation in acidic lysosomes. However, while bafilomycin A1 inhibited LAP, chloroquine did not. Finally, EACC, which inhibits the fusion of autophagosomes with lysosomes, promoted LC3 degradation possibly by the proteasome. Targeting LAP with small molecule inhibitors is important given its emerging role in infectious and autoimmune diseases.
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Affiliation(s)
- Femmy C Stempels
- Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Maaike H Janssens
- Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Martin Ter Beest
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rob J Mesman
- Department of Microbiology, RIBES, Faculty of Science, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Natalia H Revelo
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Melina Ioannidis
- Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Geert van den Bogaart
- Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.,Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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7
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Abstract
The distinct movements of macropinosome formation and maturation have corresponding biochemical activities which occur in a defined sequence of stages and transitions between those stages. Each stage in the process is regulated by variously phosphorylated derivatives of phosphatidylinositol (PtdIns) which reside in the cytoplasmic face of the membrane lipid bilayer. PtdIns derivatives phosphorylated at the 3' position of the inositol moiety, called 3' phosphoinositides (3'PIs), regulate different stages of the sequence. 3'PIs are synthesized by numerous phosphoinositide 3'-kinases (PI3K) and other lipid kinases and phosphatases, which are themselves regulated by small GTPases of the Ras superfamily. The combined actions of these enzymes localize four principal species of 3'PI to distinct domains of the plasma membrane or to discrete organelles, with distinct biochemical activities confined to those domains. Phosphatidylinositol (3,4,5)-trisphosphate (PtdIns(3,4,5)P3) and phosphatidylinositol (3,4)-bisphosphate (PtdIns(3,4)P2) regulate the early stages of macropinosome formation, which include cell surface ruffling and constrictions of circular ruffles which close into macropinosomes. Phosphatidylinositol 3-phosphate (PtdIns3P) regulates macropinosome fusion with other macropinosomes and early endocytic organelles. Phosphatidylinositol (3,5)-bisphosphate (PtdIns(3,5)P2) mediates macropinosome maturation and shrinkage, through loss of ions and water, and subsequent traffic to lysosomes. The different characteristic rates of macropinocytosis in different cell types indicate levels of regulation which may be governed by the cell's capacity to generate 3'PIs.
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Affiliation(s)
- Joel A Swanson
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Nobukazu Araki
- Department of Histology and Cell Biology, School of Medicine, Kagawa University, Miki, Kagawa, Japan
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8
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The Role of Phosphatidylinositol 3-Kinase Catalytic Subunit Type 3 in the Pathogenesis of Human Cancer. Int J Mol Sci 2021; 22:ijms222010964. [PMID: 34681622 PMCID: PMC8535862 DOI: 10.3390/ijms222010964] [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: 08/13/2021] [Revised: 10/02/2021] [Accepted: 10/08/2021] [Indexed: 12/12/2022] Open
Abstract
Phosphatidylinositol 3-kinase catalytic subunit type 3 (PIK3C3), the mammalian ortholog of yeast vesicular protein sorting 34 (Vps34), belongs to the phosphoinositide 3-kinase (PI3K) family. PIK3C3 can phosphorylate phosphatidylinositol (PtdIns) to generate phosphatidylinositol 3-phosphate (PI3P), a phospholipid central to autophagy. Inhibition of PIK3C3 successfully inhibits autophagy. Autophagy maintains cell survival when modifications occur in the cellular environment and helps tumor cells resist metabolic stress and cancer treatment. In addition, PIK3C3 could induce oncogenic transformation and enhance tumor cell proliferation, growth, and invasion through mechanisms independent of autophagy. This review addresses the structural and functional features, tissue distribution, and expression pattern of PIK3C3 in a variety of human tumors and highlights the underlying mechanisms involved in carcinogenesis. The implications in cancer biology, patient prognosis prediction, and cancer therapy are discussed. Altogether, the discovery of pharmacological inhibitors of PIK3C3 could reveal novel strategies for improving treatment outcomes for PIK3C3-mediated human diseases.
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9
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Reis LB, Filippi-Chiela EC, Ashton-Prolla P, Visioli F, Rosset C. The paradox of autophagy in Tuberous Sclerosis Complex. Genet Mol Biol 2021; 44:e20200014. [PMID: 33821877 PMCID: PMC8022228 DOI: 10.1590/1678-4685-gmb-2020-0014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 01/17/2021] [Indexed: 12/21/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder caused by germline mutations in TSC1 or TSC2 genes, which leads to the hyperactivation of the mTORC1 pathway, an important negative regulator of autophagy. This leads to the development of hamartomas in multiple organs. The variability in symptoms presents a challenge for the development of completely effective treatments for TSC. One option is the treatment with mTORC1 inhibitors, which are targeted to block cell growth and restore autophagy. However, the therapeutic effect of rapamycin seems to be more efficient in the early stages of hamartoma development, an effect that seems to be associated with the paradoxical role of autophagy in tumor establishment. Under normal conditions, autophagy is directly inhibited by mTORC1. In situations of bioenergetics stress, mTORC1 releases the Ulk1 complex and initiates the autophagy process. In this way, autophagy promotes the survival of established tumors by supplying metabolic precursors during nutrient deprivation; paradoxically, excessive autophagy has been associated with cell death in some situations. In spite of its paradoxical role, autophagy is an alternative therapeutic strategy that could be explored in TSC. This review compiles the findings related to autophagy and the new therapeutic strategies targeting this pathway in TSC.
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Affiliation(s)
- Larissa Brussa Reis
- Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul (UFRGS), Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil
| | - Eduardo C Filippi-Chiela
- Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul (UFRGS), Instituto de Ciências Básicas da Saúde, Departamento de Ciências Morfológicas, Porto Alegre, RS, Brazil
| | - Patricia Ashton-Prolla
- Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul (UFRGS), Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil.,Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Genética Médica, Porto Alegre, RS, Brazil
| | - Fernanda Visioli
- Universidade Federal do Rio Grande do Sul, Faculdade de Odontologia, Departamento de Patologia Oral, Porto Alegre, RS, Brazil
| | - Clévia Rosset
- Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Pesquisa Experimental, Laboratório de Medicina Genômica, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul (UFRGS), Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil
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10
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Kovalenko A, Sanin A, Kosmas K, Zhang L, Wang J, Akl EW, Giannikou K, Probst CK, Hougard TR, Rue RW, Krymskaya VP, Asara JM, Lam HC, Kwiatkowski DJ, Henske EP, Filippakis H. Therapeutic Targeting of DGKA-Mediated Macropinocytosis Leads to Phospholipid Reprogramming in Tuberous Sclerosis Complex. Cancer Res 2021; 81:2086-2100. [PMID: 33593821 DOI: 10.1158/0008-5472.can-20-2218] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 11/16/2020] [Accepted: 02/10/2021] [Indexed: 11/16/2022]
Abstract
Lymphangioleiomyomatosis is a rare destructive lung disease affecting primarily women and is the primary lung manifestation of tuberous sclerosis complex (TSC). In lymphangioleiomyomatosis, biallelic loss of TSC1/2 leads to hyperactivation of mTORC1 and inhibition of autophagy. To determine how the metabolic vulnerabilities of TSC2-deficient cells can be targeted, we performed a high-throughput screen utilizing the "Repurposing" library at the Broad Institute of MIT and Harvard (Cambridge, MA), with or without the autophagy inhibitor chloroquine. Ritanserin, an inhibitor of diacylglycerol kinase alpha (DGKA), was identified as a selective inhibitor of proliferation of Tsc2-/- mouse embryonic fibroblasts (MEF), with no impact on Tsc2+/+ MEFs. DGKA is a lipid kinase that metabolizes diacylglycerol to phosphatidic acid, a key component of plasma membranes. Phosphatidic acid levels were increased 5-fold in Tsc2-/- MEFs compared with Tsc2+/+ MEFs, and treatment of Tsc2-/- MEFs with ritanserin led to depletion of phosphatidic acid as well as rewiring of phospholipid metabolism. Macropinocytosis is known to be upregulated in TSC2-deficient cells. Ritanserin decreased macropinocytic uptake of albumin, limited the number of lysosomes, and reduced lysosomal activity in Tsc2-/- MEFs. In a mouse model of TSC, ritanserin treatment decreased cyst frequency and volume, and in a mouse model of lymphangioleiomyomatosis, genetic downregulation of DGKA prevented alveolar destruction and airspace enlargement. Collectively, these data indicate that DGKA supports macropinocytosis in TSC2-deficient cells to maintain phospholipid homeostasis and promote proliferation. Targeting macropinocytosis with ritanserin may represent a novel therapeutic approach for the treatment of TSC and lymphangioleiomyomatosis. SIGNIFICANCE: This study identifies macropinocytosis and phospholipid metabolism as novel mechanisms of metabolic homeostasis in mTORC1-hyperactive cells and suggest ritanserin as a novel therapeutic strategy for use in mTORC1-hyperactive tumors, including pancreatic cancer. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/8/2086/F1.large.jpg.
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Affiliation(s)
- Andrii Kovalenko
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Andres Sanin
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Kosmas Kosmas
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Long Zhang
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ji Wang
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Elie W Akl
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Krinio Giannikou
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Clemens K Probst
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Thomas R Hougard
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ryan W Rue
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Lung Biology Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Vera P Krymskaya
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Lung Biology Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - John M Asara
- Division of Signal Transduction, Beth Israel Deaconess Medical Center, Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Hilaire C Lam
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - David J Kwiatkowski
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Elizabeth P Henske
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
| | - Harilaos Filippakis
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
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