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Diaz Escarcega R, Murambadoro K, Valencia R, Moruno-Manchon JF, Furr Stimming EE, Jung SY, Tsvetkov AS. Sphingosine kinase 2 regulates protein ubiquitination networks in neurons. Mol Cell Neurosci 2024; 130:103948. [PMID: 38909878 DOI: 10.1016/j.mcn.2024.103948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 05/31/2024] [Accepted: 06/17/2024] [Indexed: 06/25/2024] Open
Abstract
Two sphingosine kinase isoforms, sphingosine kinase 1 (SPHK1) and sphingosine kinase 2 (SPHK2), synthesize the lipid sphingosine-1-phosphate (S1P) by phosphorylating sphingosine. SPHK1 is a cytoplasmic kinase, and SPHK2 is localized to the nucleus and other organelles. In the cytoplasm, the SPHK1/S1P pathway modulates autophagy and protein ubiquitination, among other processes. In the nucleus, the SPHK2/S1P pathway regulates transcription. Here, we hypothesized that the SPHK2/S1P pathway governs protein ubiquitination in neurons. We found that ectopic expression of SPHK2 increases ubiquitinated substrate levels in cultured neurons and pharmacologically inhibiting SPHK2 decreases protein ubiquitination. With mass spectrometry, we discovered that inhibiting SPHK2 affects lipid and synaptic protein networks as well as a ubiquitin-dependent protein network. Several ubiquitin-conjugating and hydrolyzing proteins, such as the E3 ubiquitin-protein ligases HUWE1 and TRIP12, the E2 ubiquitin-conjugating enzyme UBE2Z, and the ubiquitin-specific proteases USP15 and USP30, were downregulated by SPHK2 inhibition. Using RNA sequencing, we found that inhibiting SPHK2 altered lipid and neuron-specific gene networks, among others. Genes that encode the corresponding proteins from the ubiquitin-dependent protein network that we discovered with mass spectrometry were not affected by inhibiting SPHK2, indicating that the SPHK2/S1P pathway regulates ubiquitination at the protein level. We also show that both SPHK2 and HUWE1 were upregulated in the striatum of a mouse model of Huntington's disease, the BACHD mice, indicating that our findings are relevant to neurodegenerative diseases. Our results identify SPHK2/S1P as a novel regulator of protein ubiquitination networks in neurons and provide a new target for developing therapies for neurodegenerative diseases.
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Affiliation(s)
- Rocio Diaz Escarcega
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX 77030, United States of America
| | - Karen Murambadoro
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX 77030, United States of America
| | - Ricardo Valencia
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX 77030, United States of America
| | - Jose Felix Moruno-Manchon
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX 77030, United States of America
| | - Erin E Furr Stimming
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX 77030, United States of America
| | - Sung Yun Jung
- Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX 77030, United States of America.
| | - Andrey S Tsvetkov
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX 77030, United States of America; The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, United States of America; UTHealth Consortium on Aging, the University of Texas McGovern Medical School, Houston, TX 77030, United States of America.
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2
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Ripa I, Andreu S, Josa-Prado F, Fernández Gómez B, de Castro F, Arribas M, Bello-Morales R, López-Guerrero JA. Herpes Simplex Virus type 1 inhibits autophagy in glial cells but requires ATG5 for the success of viral replication. Front Microbiol 2024; 15:1411655. [PMID: 38915300 PMCID: PMC11194409 DOI: 10.3389/fmicb.2024.1411655] [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: 04/03/2024] [Accepted: 05/21/2024] [Indexed: 06/26/2024] Open
Abstract
Herpes Simplex Virus type 1 (HSV-1) 1 is a neurotropic virus that has been associated with neurodegenerative disorders. The dysregulation of autophagy by HSV-1 has been proposed as a potential cause of neurodegeneration. While studies have extensively tackled the interaction between autophagy and HSV-1 in neurons, research in glial cells is currently limited. Our studies demonstrate that HSV-1 inhibits, but not completely blocks, the formation of autophagosomes in human oligodendroglioma- and astrocytoma- derived cell lines. These findings have been confirmed in murine oligodendrocyte precursor cells (OPCs). Finally, this study investigates the impact of autophagy on HSV-1 infection in glial cells. While the lack of basal autophagy in LC3B knockout glial cells does not have a significant effect on viral infection, cells without the autophagy-related protein ATG5 exhibit reduced viral production. The absence of ATG5 leads to a decrease in the transcription and replication of viral genes, as well as a delay in the initial stages of the formation of HSV-1 replication compartments. These findings indicate that while autophagy may not play a significant role in antiviral defense in glial cells, HSV-1 may be inhibiting autophagy to exploit non-canonical functions of certain components of the autophagic machinery, such as ATG5, to benefit its lifecycle.
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Affiliation(s)
- Inés Ripa
- Department of Molecular Biology, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain
| | - Sabina Andreu
- Department of Molecular Biology, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain
| | - Fernando Josa-Prado
- Grupo de Neurobiología del Desarrollo-GNDe, Instituto Cajal-CSIC, Madrid, Spain
| | | | - Fernando de Castro
- Grupo de Neurobiología del Desarrollo-GNDe, Instituto Cajal-CSIC, Madrid, Spain
| | - María Arribas
- Department of Molecular Biology, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain
| | - Raquel Bello-Morales
- Department of Molecular Biology, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain
| | - José Antonio López-Guerrero
- Department of Molecular Biology, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain
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3
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Tong H, Yang T, Xu S, Li X, Liu L, Zhou G, Yang S, Yin S, Li XJ, Li S. Huntington's Disease: Complex Pathogenesis and Therapeutic Strategies. Int J Mol Sci 2024; 25:3845. [PMID: 38612657 PMCID: PMC11011923 DOI: 10.3390/ijms25073845] [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: 02/19/2024] [Revised: 03/21/2024] [Accepted: 03/26/2024] [Indexed: 04/14/2024] Open
Abstract
Huntington's disease (HD) arises from the abnormal expansion of CAG repeats in the huntingtin gene (HTT), resulting in the production of the mutant huntingtin protein (mHTT) with a polyglutamine stretch in its N-terminus. The pathogenic mechanisms underlying HD are complex and not yet fully elucidated. However, mHTT forms aggregates and accumulates abnormally in neuronal nuclei and processes, leading to disruptions in multiple cellular functions. Although there is currently no effective curative treatment for HD, significant progress has been made in developing various therapeutic strategies to treat HD. In addition to drugs targeting the neuronal toxicity of mHTT, gene therapy approaches that aim to reduce the expression of the mutant HTT gene hold great promise for effective HD therapy. This review provides an overview of current HD treatments, discusses different therapeutic strategies, and aims to facilitate future therapeutic advancements in the field.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Xiao-Jiang Li
- Guangdong Key Laboratory of Non-Human Primate Research, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China; (H.T.); (T.Y.); (S.X.); (X.L.); (L.L.); (G.Z.); (S.Y.); (S.Y.)
| | - Shihua Li
- Guangdong Key Laboratory of Non-Human Primate Research, Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China; (H.T.); (T.Y.); (S.X.); (X.L.); (L.L.); (G.Z.); (S.Y.); (S.Y.)
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4
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Zhang Y, Pei Y, Sun Y, Yang X, Liang J, Yin Z, Liu QS, Zhou Q, Jiang G. AhR Agonistic Components in Urban Particulate Matter Regulate Astrocytic Activation and Function. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:4571-4580. [PMID: 38430186 DOI: 10.1021/acs.est.4c00237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/03/2024]
Abstract
Exposure to atmospheric particulate matter (PM) has been found to accelerate the onset of neurological disorders via the induction of detrimental neuroinflammatory responses. To reveal how astrocytes respond to urban atmospheric PM stimulation, a commercially available standard reference material (SRM1648a) was tested in this study on the activation of rat cortical astrocytes. The results showed that SRM1648a stimulation induced both A1 and A2 phenotypes in astrocytes, as characterized by the exposure concentration-dependent increases in Fkbp5, Sphk1, S100a10, and Il6 mRNA levels. Studying the functional alterations of astrocytes indicated that the neurotrophic factors of Gdnf and Ngf were transcriptionally upregulated due to astrocytic A2-type activation. SRM1648a also promoted autonomous motility of astrocytes and elevated the expressions of chemokines. The aryl hydrocarbon receptor (AhR) agonistic components, such as polycyclic aromatic hydrocarbons (PAHs), were recognized to greatly contribute to SRM1648a-induced effects on astrocytes, which was confirmed by the attenuation of PM-disturbed astrocytic effects via AhR blockage. This study, for the first time, uncovered the direct regulation of urban atmospheric PM on astrocytic activation and function and traced the containing bioactive components (e.g., PAHs) with AhR agonistic activity. The findings provided new knowledge on understanding the ambiguous neurological disturbance from ambient fine PM pollution.
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Affiliation(s)
- Yuzhu Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yao Pei
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yumiao Sun
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xiaoxi Yang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jiefeng Liang
- Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Zhipeng Yin
- Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Qian S Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Qunfang Zhou
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
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Morishige JI, Yoshioka K, Nakata H, Ishimaru K, Nagata N, Tanaka T, Takuwa Y, Ando H. Sphingosine kinase 1 is involved in triglyceride breakdown by maintaining lysosomal integrity in brown adipocytes. J Lipid Res 2023; 64:100450. [PMID: 37751791 PMCID: PMC10630120 DOI: 10.1016/j.jlr.2023.100450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 08/30/2023] [Accepted: 09/15/2023] [Indexed: 09/28/2023] Open
Abstract
Sphingosine 1-phosphate (S1P) has been implicated in brown adipose tissue (BAT) formation and energy consumption; however, the mechanistic role of sphingolipids, including S1P, in BAT remains unclear. Here, we showed that, in mice, BAT activation by cold exposure upregulated mRNA and protein expression of the S1P-synthesizing enzyme sphingosine kinase 1 (SphK1) and S1P production in BAT. Treatment of wild-type brown adipocytes with exogenous S1P or S1P receptor subtype-selective agonists stimulated triglyceride (TG) breakdown only marginally, compared with noradrenaline. However, genetic deletion of Sphk1 resulted in hypothermia and diminished body weight loss upon cold exposure, suggesting that SphK1 is involved in thermogenesis through mechanisms different from receptor-mediated, extracellular action of S1P. In BAT of wild-type mice, SphK1 was localized largely in the lysosomes of brown adipocytes. In the brown adipocytes of Sphk1-/- mice, the number of lysosomes was reduced and lysosomal function, including proteolytic activity, acid esterase activity, and motility, was impaired. Concordantly, nuclear translocation of transcription factor EB, a master transcriptional regulator of lysosome biogenesis, was reduced, leading to decreased mRNA expression of the lysosome-related genes in Sphk1-/- BAT. Moreover, BAT of Sphk1-/- mice showed greater TG accumulation with dominant larger lipid droplets in brown adipocytes. Inhibition of lysosomes with chloroquine resulted in a less extent of triglyceride accumulation in Sphk1-/- brown adipocytes compared with wild-type brown adipocytes, suggesting a reduced lysosome-mediated TG breakdown in Sphk1-/- mice. Our results indicate a novel role of SphK1 in lysosomal integrity, which is required for TG breakdown and thermogenesis in BAT.
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Affiliation(s)
- Jun-Ichi Morishige
- Department of Cellular and Molecular Function Analysis, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan.
| | - Kazuaki Yoshioka
- Department of Physiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Hiroki Nakata
- Department of Clinical Engineering, Faculty of Health Sciences, Komatsu University, Komatsu, Japan
| | - Kazuhiro Ishimaru
- Department of Physiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Naoto Nagata
- Department of Cellular and Molecular Function Analysis, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Tamotsu Tanaka
- Graduate School of Technology, Industrial and Social Sciences, Tokushima University, Tokushima, Japan
| | - Yoh Takuwa
- Department of Physiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan.
| | - Hitoshi Ando
- Department of Cellular and Molecular Function Analysis, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan.
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Escarcega RD, Patil AA, Meyer MD, Moruno-Manchon JF, Silvagnoli AD, McCullough LD, Tsvetkov AS. The Tardigrade damage suppressor protein Dsup promotes DNA damage in neurons. Mol Cell Neurosci 2023; 125:103826. [PMID: 36858083 PMCID: PMC10247392 DOI: 10.1016/j.mcn.2023.103826] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 02/18/2023] [Accepted: 02/22/2023] [Indexed: 03/02/2023] Open
Abstract
Tardigrades are microscopic invertebrates, which are capable of withstanding extreme environmental conditions, including high levels of radiation. A Tardigrade protein, Dsup (Damage Suppressor), protects the Tardigrade's DNA during harsh environmental stress and X-rays. When expressed in cancer cells, Dsup protects DNA from single- and double-strand breaks (DSBs) induced by radiation, increases survival of irradiated cells, and protects DNA from reactive oxygen species. These unusual properties of Dsup suggested that understanding how the protein functions may help in the design of small molecules that could protect humans during radiotherapy or space travel. Here, we investigated if Dsup is protective in cortical neurons cultured from rat embryos. We discovered that, in cortical neurons, the codon-optimized Dsup localizes to the nucleus and, surprisingly, promotes neurotoxicity, leading to neurodegeneration. Unexpectedly, we found that Dsup expression results in the formation of DNA DSBs in cultured neurons. With electron microscopy, we discovered that Dsup promotes chromatin condensation. Unlike Dsup's protective properties in cancerous cells, in neurons, Dsup promotes neurotoxicity, induces DNA damage, and rearranges chromatin. Neurons are sensitive to Dsup, and Dsup is a doubtful surrogate for DNA protection in neuronal cells.
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Affiliation(s)
- Rocio Diaz Escarcega
- Department of Neurology, The University of Texas McGovern Medical School at Houston, TX 77030, United States of America
| | - Abhijeet A Patil
- Department of Neurology, The University of Texas McGovern Medical School at Houston, TX 77030, United States of America
| | - Matthew D Meyer
- Shared Equipment Authority, Rice University, Houston, TX 77005, United States of America
| | - Jose F Moruno-Manchon
- Department of Neurology, The University of Texas McGovern Medical School at Houston, TX 77030, United States of America
| | - Alexander D Silvagnoli
- Department of Neurology, The University of Texas McGovern Medical School at Houston, TX 77030, United States of America
| | - Louise D McCullough
- Department of Neurology, The University of Texas McGovern Medical School at Houston, TX 77030, United States of America; The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, United States of America
| | - Andrey S Tsvetkov
- Department of Neurology, The University of Texas McGovern Medical School at Houston, TX 77030, United States of America; The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, United States of America; UTHealth Consortium on Aging, The University of Texas McGovern Medical School, Houston, TX 77030, United States of America.
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7
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van Echten-Deckert G. The role of sphingosine 1-phosphate metabolism in brain health and disease. Pharmacol Ther 2023; 244:108381. [PMID: 36907249 DOI: 10.1016/j.pharmthera.2023.108381] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 03/02/2023] [Accepted: 03/06/2023] [Indexed: 03/13/2023]
Abstract
Lipids are essential structural and functional components of the central nervous system (CNS). Sphingolipids are ubiquitous membrane components which were discovered in the brain in the late 19th century. In mammals, the brain contains the highest concentration of sphingolipids in the body. Sphingosine 1-phosphate (S1P) derived from membrane sphingolipids evokes multiple cellular responses which, depending on its concentration and localization, make S1P a double-edged sword in the brain. In the present review we highlight the role of S1P in brain development and focus on the often contrasting findings regarding its contributions to the initiation, progression and potential recovery of different brain pathologies, including neurodegeneration, multiple sclerosis (MS), brain cancers, and psychiatric illnesses. A detailed understanding of the critical implications of S1P in brain health and disease may open the door for new therapeutic options. Thus, targeting S1P-metabolizing enzymes and/or signaling pathways might help overcome, or at least ameliorate, several brain illnesses.
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8
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Supruniuk E, Żebrowska E, Maciejczyk M, Zalewska A, Chabowski A. Lipid peroxidation and sphingolipid alterations in the cerebral cortex and hypothalamus of rats fed a high-protein diet. Nutrition 2023; 107:111942. [PMID: 36621260 DOI: 10.1016/j.nut.2022.111942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 11/10/2022] [Accepted: 12/08/2022] [Indexed: 12/15/2022]
Abstract
OBJECTIVES High-protein diets (HPDs) are widely accepted to enhance satiety and energy expenditure and thus have become a popular strategy to lose weight and facilitate muscle protein synthesis. However, long-term high-protein consumption could be linked with metabolic and clinical problems such as renal and liver dysfunctions. This study verified the effects of 8-wk high-protein ingestion on lipid peroxidation and sphingolipid metabolism in the plasma, cerebral cortex, and hypothalamus in rats. METHODS Immunoenzymatic and spectrophotometric methods were applied to assess oxidation-reduction (redox) biomarkers and neutral sphingomyelinase activity, whereas gas-liquid chromatography and high-performance liquid chromatography were used to examine sphingolipid levels. RESULTS The vast majority of HPD-related alterations was restricted to the hypothalamus. Specifically, an increased rate of lipid peroxidation (increased lipid hydroperoxides, 8-isoprostanes, and thiobarbituric acid reactive substances) associated with ceramide accumulation via the activation of de novo synthesis (decreased sphinganine), salvage pathway (decreased sphingosine), and sphingomyelin hydrolysis (decreased sphingomyelin and increased neutral sphingomyelinase activity) was noted. CONCLUSIONS This study showed that HPD substantially affected hypothalamic metabolic pathways, which potentially alter cerebral output signals to the peripheral tissues.
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Affiliation(s)
- Elżbieta Supruniuk
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland.
| | - Ewa Żebrowska
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland.
| | - Mateusz Maciejczyk
- Department of Hygiene, Epidemiology and Ergonomics, Medical University of Bialystok, Bialystok, Poland.
| | - Anna Zalewska
- Department of Restorative Dentistry, Medical University of Bialystok, Bialystok, Poland; Independent Laboratory of Experimental Dentistry, Medical University of Bialystok, Bialystok, Poland.
| | - Adrian Chabowski
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland.
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9
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Alam S, Afsar SY, Van Echten-Deckert G. S1P Released by SGPL1-Deficient Astrocytes Enhances Astrocytic ATP Production via S1PR 2,4, Thus Keeping Autophagy in Check: Potential Consequences for Brain Health. Int J Mol Sci 2023; 24:ijms24054581. [PMID: 36902011 PMCID: PMC10003137 DOI: 10.3390/ijms24054581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 02/22/2023] [Accepted: 02/24/2023] [Indexed: 03/02/2023] Open
Abstract
Astrocytes are critical players in brain health and disease. Sphingosine-1-phosphate (S1P), a bioactive signaling lipid, is involved in several vital processes, including cellular proliferation, survival, and migration. It was shown to be crucial for brain development. Its absence is embryonically lethal, affecting, inter alia, the anterior neural tube closure. However, an excess of S1P due to mutations in S1P-lyase (SGPL1), the enzyme responsible for its constitutive removal, is also harmful. Of note, the gene SGPL1 maps to a region prone to mutations in several human cancers and also in S1P-lyase insufficiency syndrome (SPLIS) characterized by several symptoms, including peripheral and central neurological defects. Here, we investigated the impact of S1P on astrocytes in a mouse model with the neural-targeted ablation of SGPL1. We found that SGPL1 deficiency, and hence the accumulation of its substrate, S1P, causes the elevated expression of glycolytic enzymes and preferentially directs pyruvate into the tricarboxylic acid (TCA) cycle through its receptors (S1PR2,4). In addition, the activity of TCA regulatory enzymes was increased, and consequently, so was the cellular ATP content. The high energy load activates the mammalian target of rapamycin (mTOR), thus keeping astrocytic autophagy in check. Possible consequences for the viability of neurons are discussed.
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10
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Brandebura AN, Paumier A, Onur TS, Allen NJ. Astrocyte contribution to dysfunction, risk and progression in neurodegenerative disorders. Nat Rev Neurosci 2023; 24:23-39. [PMID: 36316501 DOI: 10.1038/s41583-022-00641-1] [Citation(s) in RCA: 105] [Impact Index Per Article: 105.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2022] [Indexed: 11/06/2022]
Abstract
There is increasing appreciation that non-neuronal cells contribute to the initiation, progression and pathology of diverse neurodegenerative disorders. This Review focuses on the role of astrocytes in disorders including Alzheimer disease, Parkinson disease, Huntington disease and amyotrophic lateral sclerosis. The important roles astrocytes have in supporting neuronal function in the healthy brain are considered, along with studies that have demonstrated how the physiological properties of astrocytes are altered in neurodegenerative disorders and may explain their contribution to neurodegeneration. Further, the question of whether in neurodegenerative disorders with specific genetic mutations these mutations directly impact on astrocyte function, and may suggest a driving role for astrocytes in disease initiation, is discussed. A summary of how astrocyte transcriptomic and proteomic signatures are altered during the progression of neurodegenerative disorders and may relate to functional changes is provided. Given the central role of astrocytes in neurodegenerative disorders, potential strategies to target these cells for future therapeutic avenues are discussed.
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Affiliation(s)
- Ashley N Brandebura
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Adrien Paumier
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Tarik S Onur
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Nicola J Allen
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA.
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11
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Zhu X, Schrader JM, Irizarry BA, Smith SO, Van Nostrand WE. Impact of Aβ40 and Aβ42 Fibrils on the Transcriptome of Primary Astrocytes and Microglia. Biomedicines 2022; 10:2982. [PMID: 36428550 PMCID: PMC9688026 DOI: 10.3390/biomedicines10112982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/27/2022] [Accepted: 11/16/2022] [Indexed: 11/22/2022] Open
Abstract
Fibrillar amyloid β-protein (Aβ) deposits in the brain, which are primarily composed of Aβ40 or Aβ42 peptides, are key pathological features of Alzheimer's disease (AD) and related disorders. Although the underlying mechanisms are still not clear, the Aβ fibrils can trigger a number of cellular responses, including activation of astrocytes and microglia. In addition, fibril structures of the Aβ40 and Aβ42 peptides are known to be polymorphic, which poses a challenge for attributing the contribution of different Aβ sequences and structures to brain pathology. Here, we systematically treated primary astrocytes and microglia with single, well-characterized polymorphs of Aβ40 or Aβ42 fibrils, and performed bulk RNA sequencing to assess cell-specific changes in gene expression. A greater number of genes were up-regulated by Aβ42 fibril-treated glial cells (251 and 2133 genes in astrocyte and microglia, respectively) compared with the Aβ40 fibril-treated glial cells (191 and 251 genes in astrocytes and microglia, respectively). Immunolabeling studies in an AD rat model with parenchymal fibrillar Aβ42 plaques confirmed the expression of PAI-1, MMP9, MMP12, CCL2, and C1r in plaque-associated microglia, and iNOS, GBP2, and C3D in plaque-associated astrocytes, validating markers from the RNA sequence data. In order to better understand these Aβ fibril-induced gene changes, we analyzed gene expression patterns using the Ingenuity pathway analysis program. These analyses further highlighted that Aβ42 fibril treatment up-regulated cellular activation pathways and immune response pathways in glial cells, including IL1β and TNFα in astrocytes, and microglial activation and TGFβ1 in microglia. Further analysis revealed that a number of disease-associated microglial (DAM) genes were surprisingly suppressed in Aβ40 fibril treated microglia. Together, the present findings indicate that Aβ42 fibrils generally show similar, but stronger, stimulating activity of glial cells compared with Aβ40 fibril treatment.
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Affiliation(s)
- Xiaoyue Zhu
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI 02881, USA
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - Joseph M. Schrader
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI 02881, USA
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - Brandon A. Irizarry
- Center for Structural Biology, Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Steven O. Smith
- Center for Structural Biology, Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - William E. Van Nostrand
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI 02881, USA
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA
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12
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Su PW, Zhai Z, Wang T, Zhang YN, Wang Y, Ma K, Han BB, Wu ZC, Yu HY, Zhao HJ, Wang SJ. Research progress on astrocyte autophagy in ischemic stroke. Front Neurol 2022; 13:951536. [PMID: 36110390 PMCID: PMC9468275 DOI: 10.3389/fneur.2022.951536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 07/28/2022] [Indexed: 11/13/2022] Open
Abstract
Ischemic stroke is a highly disabling and potentially fatal disease. After ischemic stroke, autophagy plays a key regulatory role as an intracellular catabolic pathway for misfolded proteins and damaged organelles. Mounting evidence indicates that astrocytes are strongly linked to the occurrence and development of cerebral ischemia. In recent years, great progress has been made in the investigation of astrocyte autophagy during ischemic stroke. This article summarizes the roles and potential mechanisms of astrocyte autophagy in ischemic stroke, briefly expounds on the crosstalk of astrocyte autophagy with pathological mechanisms and its potential protective effect on neurons, and reviews astrocytic autophagy-targeted therapeutic methods for cerebral ischemia. The broader aim of the report is to provide new perspectives and strategies for the treatment of cerebral ischemia and a reference for future research on cerebral ischemia.
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Affiliation(s)
- Pei-Wei Su
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Zhe Zhai
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Tong Wang
- School of Nursing, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Ya-Nan Zhang
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
- Shandong Co-innovation Center of Classic Traditional Chinese Medicine Formula, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Yuan Wang
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
- Shandong Co-innovation Center of Classic Traditional Chinese Medicine Formula, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Ke Ma
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
- Shandong Co-innovation Center of Classic Traditional Chinese Medicine Formula, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Bing-Bing Han
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
- Shandong Co-innovation Center of Classic Traditional Chinese Medicine Formula, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Zhi-Chun Wu
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
- Shandong Co-innovation Center of Classic Traditional Chinese Medicine Formula, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Hua-Yun Yu
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
- Shandong Co-innovation Center of Classic Traditional Chinese Medicine Formula, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Hai-Jun Zhao
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
- Shandong Co-innovation Center of Classic Traditional Chinese Medicine Formula, Shandong University of Traditional Chinese Medicine, Jinan, China
- *Correspondence: Hai-Jun Zhao
| | - Shi-Jun Wang
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
- Shandong Co-innovation Center of Classic Traditional Chinese Medicine Formula, Shandong University of Traditional Chinese Medicine, Jinan, China
- Shi-Jun Wang
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13
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Zhou Z, Zhou J, Liao J, Chen Z, Zheng Y. The Emerging Role of Astrocytic Autophagy in Central Nervous System Disorders. Neurochem Res 2022; 47:3697-3708. [PMID: 35960484 DOI: 10.1007/s11064-022-03714-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 07/15/2022] [Accepted: 07/29/2022] [Indexed: 10/15/2022]
Abstract
Astrocytes act as "housekeeping cells" for maintaining cerebral homeostasis and play an important role in many disorders. Recent studies further highlight the contribution of autophagy to astrocytic functions, including astrogenesis, the astrocytic removal of neurotoxins or stressors, and astrocytic polarization. More importantly, genetic and pharmacological approaches have provided evidence that outlines the contributions of astrocytic autophagy to several brain disorders, including neurodegeneration, cerebral ischemia, and depression. In this study, we summarize the emerging role of autophagy in regulating astrocytic functions and discuss the contributions of astrocytic autophagy to different CNS disorders.
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Affiliation(s)
- Zhuchen Zhou
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Jing Zhou
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Jie Liao
- Pharmaceutical Informatics Institute, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zhong Chen
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Yanrong Zheng
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China.
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14
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Custodia A, Romaus-Sanjurjo D, Aramburu-Núñez M, Álvarez-Rafael D, Vázquez-Vázquez L, Camino-Castiñeiras J, Leira Y, Pías-Peleteiro JM, Aldrey JM, Sobrino T, Ouro A. Ceramide/Sphingosine 1-Phosphate Axis as a Key Target for Diagnosis and Treatment in Alzheimer's Disease and Other Neurodegenerative Diseases. Int J Mol Sci 2022; 23:8082. [PMID: 35897658 PMCID: PMC9331765 DOI: 10.3390/ijms23158082] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 07/15/2022] [Accepted: 07/20/2022] [Indexed: 12/10/2022] Open
Abstract
Alzheimer's disease (AD) is considered the most prevalent neurodegenerative disease and the leading cause of dementia worldwide. Sphingolipids, such as ceramide or sphingosine 1-phosphate, are bioactive molecules implicated in structural and signaling functions. Metabolic dysfunction in the highly conserved pathways to produce sphingolipids may lead to or be a consequence of an underlying disease. Recent studies on transcriptomics and sphingolipidomics have observed alterations in sphingolipid metabolism of both enzymes and metabolites involved in their synthesis in several neurodegenerative diseases, including AD. In this review, we highlight the most relevant findings related to ceramide and neurodegeneration, with a special focus on AD.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Tomás Sobrino
- Neuro Aging Laboratory Group (NEURAL), Clinical Neurosciences Research Laboratories (LINCs), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain; (A.C.); (D.R.-S.); (M.A.-N.); (D.Á.-R.); (L.V.-V.); (J.C.-C.); (Y.L.); (J.M.P.-P.); (J.M.A.)
| | - Alberto Ouro
- Neuro Aging Laboratory Group (NEURAL), Clinical Neurosciences Research Laboratories (LINCs), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain; (A.C.); (D.R.-S.); (M.A.-N.); (D.Á.-R.); (L.V.-V.); (J.C.-C.); (Y.L.); (J.M.P.-P.); (J.M.A.)
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15
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Autophagy: Identification of MTMR5 as a neuron-enriched suppressor. Curr Biol 2022; 32:R574-R577. [PMID: 35728530 PMCID: PMC9994184 DOI: 10.1016/j.cub.2022.04.075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A puzzle of autophagy in neurons is that, unlike in other cells, it is not robustly induced by inhibition of mammalian target of rapamycin (mTOR). A new study now solves this conundrum and establishes that myotubularin-related phosphatase 5 limits the induction of neuronal autophagy by mTOR inhibitors.
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16
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Granatiero V, Sayles NM, Savino AM, Konrad C, Kharas MG, Kawamata H, Manfredi G. Modulation of the IGF1R-MTOR pathway attenuates motor neuron toxicity of human ALS SOD1 G93A astrocytes. Autophagy 2021; 17:4029-4042. [PMID: 33749521 PMCID: PMC8726657 DOI: 10.1080/15548627.2021.1899682] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 02/25/2021] [Accepted: 03/03/2021] [Indexed: 12/13/2022] Open
Abstract
ALS (amyotrophic lateral sclerosis), the most common motor neuron disease, causes muscle denervation and rapidly fatal paralysis. While motor neurons are the most affected cells in ALS, studies on the pathophysiology of the disease have highlighted the importance of non-cell autonomous mechanisms, which implicate astrocytes and other glial cells. In ALS, subsets of reactive astrocytes lose their physiological functions and become toxic for motor neurons, thereby contributing to disease pathogenesis. Evidence of astrocyte contribution to disease pathogenesis are well established in cellular and animal models of familial ALS linked to mutant SOD1, where astrocytes promote motor neuron cell death. The mechanism underlying astrocytes reactivity in conditions of CNS injury have been shown to involve the MTOR pathway. However, the role of this conserved metabolic signaling pathway, and the potential therapeutic effects of its modulation, have not been investigated in ALS astrocytes. Here, we show elevated activation of the MTOR pathway in human-derived astrocytes harboring mutant SOD1, which results in inhibition of macroautophagy/autophagy, increased cell proliferation, and enhanced astrocyte reactivity. We demonstrate that MTOR pathway activation in mutant SOD1 astrocytes is due to post-transcriptional upregulation of the IGF1R (insulin like growth factor 1 receptor), an upstream positive modulator of the MTOR pathway. Importantly, inhibition of the IGF1R-MTOR pathway decreases cell proliferation and reactivity of mutant SOD1 astrocytes, and attenuates their toxicity to motor neurons. These results suggest that modulation of astrocytic IGF1R-MTOR pathway could be a viable therapeutic strategy in SOD1 ALS and potentially other neurological diseases.Abbreviations: ACM: astrocyte conditioned medium; AKT: AKT serine/threonine kinase; ALS: amyotrophic lateral sclerosis; BrdU: thymidine analog 5-bromo-2'-deoxyuridine; CNS: central nervous system; EIF4EBP1/4EBP1: eukaryotic translation initiation factor 4E binding protein 1; GFAP: glial fibrillary acidic protein; IGF1R: insulin like growth factor 1 receptor; INSR: insulin receptor; iPSA: iPSC-derived astrocytes; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta;MTOR: mechanistic target of rapamycin kinase; NES: nestin; PPK1: 3-phosphoinositide dependent protein kinase 1; PI: propidium iodide; PPP: picropodophyllotoxin; PTEN: phosphatase and tensin homolog; S100B/S100β: S100 calcium binding protein B; SLC1A3/ EAAT1: solute carrier family 1 member 3; SMI-32: antibody to nonphosphorylated NEFH; SOD1: superoxide dismutase 1; TUBB3: tubulin beta 3 class III; ULK1: unc-51 like autophagy activating kinase 1.
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Affiliation(s)
- Veronica Granatiero
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York, USA
| | - Nicole M. Sayles
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York, USA
| | - Angela M. Savino
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Csaba Konrad
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York, USA
| | - Michael G. Kharas
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Hibiki Kawamata
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York, USA
| | - Giovanni Manfredi
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York, USA
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17
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Patrizz AN, Moruno-Manchon JF, O’Keefe LM, Doran SJ, Patel AR, Venna VR, Tsvetkov AS, Li J, McCullough LD. Sex-Specific Differences in Autophagic Responses to Experimental Ischemic Stroke. Cells 2021; 10:cells10071825. [PMID: 34359998 PMCID: PMC8304137 DOI: 10.3390/cells10071825] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/14/2021] [Accepted: 07/16/2021] [Indexed: 12/25/2022] Open
Abstract
Ischemic stroke triggers a series of complex pathophysiological processes including autophagy. Differential activation of autophagy occurs in neurons derived from males versus females after stressors such as nutrient deprivation. Whether autophagy displays sexual dimorphism after ischemic stroke is unknown. We used a cerebral ischemia mouse model (middle cerebral artery occlusion, MCAO) to evaluate the effects of inhibiting autophagy in ischemic brain pathology. We observed that inhibiting autophagy reduced infarct volume in males and ovariectomized females. However, autophagy inhibition enhanced infarct size in females and in ovariectomized females supplemented with estrogen compared to control mice. We also observed that males had increased levels of Beclin1 and LC3 and decreased levels of pULK1 and p62 at 24 h, while females had decreased levels of Beclin1 and increased levels of ATG7. Furthermore, the levels of autophagy markers were increased under basal conditions and after oxygen and glucose deprivation in male neurons compared with female neurons in vitro. E2 supplementation significantly inhibited autophagy only in male neurons, and was beneficial for cell survival only in female neurons. This study shows that autophagy in the ischemic brain differs between the sexes, and that autophagy regulators have different effects in a sex-dependent manner in neurons.
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Affiliation(s)
- Anthony N. Patrizz
- Department of Neurology, McGovern Medical School at the University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA; (A.N.P.); (J.F.M.-M.); (V.R.V.); (A.S.T.); (J.L.)
| | - Jose F. Moruno-Manchon
- Department of Neurology, McGovern Medical School at the University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA; (A.N.P.); (J.F.M.-M.); (V.R.V.); (A.S.T.); (J.L.)
| | - Lena M. O’Keefe
- Department of Neurology, Beth Israel Deaconess Hospital, 330 Brookline Avenue, Boston, MA 02215, USA;
| | - Sarah J. Doran
- Department of Neuroscience, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030, USA; (S.J.D.); (A.R.P.)
| | - Anita R. Patel
- Department of Neuroscience, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030, USA; (S.J.D.); (A.R.P.)
| | - Venugopal R. Venna
- Department of Neurology, McGovern Medical School at the University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA; (A.N.P.); (J.F.M.-M.); (V.R.V.); (A.S.T.); (J.L.)
| | - Andrey S. Tsvetkov
- Department of Neurology, McGovern Medical School at the University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA; (A.N.P.); (J.F.M.-M.); (V.R.V.); (A.S.T.); (J.L.)
| | - Jun Li
- Department of Neurology, McGovern Medical School at the University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA; (A.N.P.); (J.F.M.-M.); (V.R.V.); (A.S.T.); (J.L.)
| | - Louise D. McCullough
- Department of Neurology, McGovern Medical School at the University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77030, USA; (A.N.P.); (J.F.M.-M.); (V.R.V.); (A.S.T.); (J.L.)
- Correspondence:
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18
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Tabor N, Ngwa C, Mitteaux J, Meyer MD, Moruno-Manchon JF, Zhu L, Liu F, Monchaud D, McCullough LD, Tsvetkov AS. Differential responses of neurons, astrocytes, and microglia to G-quadruplex stabilization. Aging (Albany NY) 2021; 13:15917-15941. [PMID: 34139671 PMCID: PMC8266374 DOI: 10.18632/aging.203222] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 06/12/2021] [Indexed: 12/29/2022]
Abstract
The G-quadruplex (G4-DNA or G4) is a secondary DNA structure formed by DNA sequences containing multiple runs of guanines. While it is now firmly established that stabilized G4s lead to enhanced genomic instability in cancer cells, whether and how G4s contribute to genomic instability in brain cells is still not clear. We previously showed that, in cultured primary neurons, small-molecule G4 stabilizers promote formation of DNA double-strand breaks (DSBs) and downregulate the Brca1 gene. Here, we determined if G4-dependent Brca1 downregulation is unique to neurons or if the effects in neurons also occur in astrocytes and microglia. We show that primary neurons, astrocytes and microglia basally exhibit different G4 landscapes. Stabilizing G4-DNA with the G4 ligand pyridostatin (PDS) differentially modifies chromatin structure in these cell types. Intriguingly, PDS promotes DNA DSBs in neurons, astrocytes and microglial cells, but fails to downregulate Brca1 in astrocytes and microglia, indicating differences in DNA damage and repair pathways between brain cell types. Taken together, our findings suggest that stabilized G4-DNA contribute to genomic instability in the brain and may represent a novel senescence pathway in brain aging.
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Affiliation(s)
- Natalie Tabor
- Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA
| | - Conelius Ngwa
- Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA
| | - Jeremie Mitteaux
- Institut de Chimie Moléculaire (ICMUB), UBFC Dijon, CNRS UMR6302, Dijon, France
| | - Matthew D. Meyer
- Shared Equipment Authority, Rice University, Houston, TX 77005, USA
| | - Jose F. Moruno-Manchon
- Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA
| | - Liang Zhu
- Biostatistics and Epidemiology Research Design Core Center for Clinical and Translational Sciences, The University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA
- Department of Internal Medicine, The University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA
| | - Fudong Liu
- Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA
| | - David Monchaud
- Institut de Chimie Moléculaire (ICMUB), UBFC Dijon, CNRS UMR6302, Dijon, France
| | - Louise D. McCullough
- Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Andrey S. Tsvetkov
- Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, USA
- UTHealth Consortium on Aging, The University of Texas McGovern Medical School, Houston, TX 77030, USA
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19
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Pan PY, Zhu J, Rizvi A, Zhu X, Tanaka H, Dreyfus CF. Synaptojanin1 deficiency upregulates basal autophagosome formation in astrocytes. J Biol Chem 2021; 297:100873. [PMID: 34126070 PMCID: PMC8258991 DOI: 10.1016/j.jbc.2021.100873] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/02/2021] [Accepted: 06/10/2021] [Indexed: 01/07/2023] Open
Abstract
Macroautophagy dysregulation is implicated in multiple neurological disorders, such as Parkinson's disease. While autophagy pathways are heavily researched in heterologous cells and neurons, regulation of autophagy in the astrocyte, the most abundant cell type in the mammalian brain, is less well understood. Missense mutations in the Synj1 gene encoding Synaptojanin1 (Synj1), a neuron-enriched lipid phosphatase, have been linked to Parkinsonism with seizures. Our previous study showed that the Synj1 haploinsufficient (Synj1+/−) mouse exhibits age-dependent autophagy impairment in multiple brain regions. Here, we used cultured astrocytes from Synj1-deficient mice to investigate its role in astrocyte autophagy. We report that Synj1 is expressed in low levels in astrocytes and represses basal autophagosome formation. We demonstrate using cellular imaging that Synj1-deficient astrocytes exhibit hyperactive autophagosome formation, represented by an increase in the size and number of GFP-microtubule-associated protein 1A/1B-light chain 3 structures. Interestingly, Synj1 deficiency is also associated with an impairment in stress-induced autophagy clearance. We show, for the first time, that the Parkinsonism-associated R839C mutation impacts autophagy in astrocytes. The impact of this mutation on the phosphatase function of Synj1 resulted in elevated basal autophagosome formation that mimics Synj1 deletion. We found that the membrane expression of the astrocyte-specific glucose transporter GluT-1 was reduced in Synj1-deficient astrocytes. Consistently, AMP-activated protein kinase activity was elevated, suggesting altered glucose sensing in Synj1-deficient astrocytes. Expressing exogenous GluT-1 in Synj1-deficient astrocytes reversed the autophagy impairment, supporting a role for Synj1 in regulating astrocyte autophagy via disrupting glucose-sensing pathways. Thus, our work suggests a novel mechanism for Synj1-related Parkinsonism involving astrocyte dysfunction.
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Affiliation(s)
- Ping-Yue Pan
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA.
| | - Justin Zhu
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Asma Rizvi
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Xinyu Zhu
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Hikari Tanaka
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
| | - Cheryl F Dreyfus
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, USA
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20
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Chua JP, De Calbiac H, Kabashi E, Barmada SJ. Autophagy and ALS: mechanistic insights and therapeutic implications. Autophagy 2021; 18:254-282. [PMID: 34057020 PMCID: PMC8942428 DOI: 10.1080/15548627.2021.1926656] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Mechanisms of protein homeostasis are crucial for overseeing the clearance of misfolded and toxic proteins over the lifetime of an organism, thereby ensuring the health of neurons and other cells of the central nervous system. The highly conserved pathway of autophagy is particularly necessary for preventing and counteracting pathogenic insults that may lead to neurodegeneration. In line with this, mutations in genes that encode essential autophagy factors result in impaired autophagy and lead to neurodegenerative conditions such as amyotrophic lateral sclerosis (ALS). However, the mechanistic details underlying the neuroprotective role of autophagy, neuronal resistance to autophagy induction, and the neuron-specific effects of autophagy-impairing mutations remain incompletely defined. Further, the manner and extent to which non-cell autonomous effects of autophagy dysfunction contribute to ALS pathogenesis are not fully understood. Here, we review the current understanding of the interplay between autophagy and ALS pathogenesis by providing an overview of critical steps in the autophagy pathway, with special focus on pivotal factors impaired by ALS-causing mutations, their physiologic effects on autophagy in disease models, and the cell type-specific mechanisms regulating autophagy in non-neuronal cells which, when impaired, can contribute to neurodegeneration. This review thereby provides a framework not only to guide further investigations of neuronal autophagy but also to refine therapeutic strategies for ALS and related neurodegenerative diseases.Abbreviations: ALS: amyotrophic lateral sclerosis; Atg: autophagy-related; CHMP2B: charged multivesicular body protein 2B; DPR: dipeptide repeat; FTD: frontotemporal dementia; iPSC: induced pluripotent stem cell; LIR: LC3-interacting region; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; PINK1: PTEN induced kinase 1; RNP: ribonuclear protein; sALS: sporadic ALS; SPHK1: sphingosine kinase 1; TARDBP/TDP-43: TAR DNA binding protein; TBK1: TANK-binding kinase 1; TFEB: transcription factor EB; ULK: unc-51 like autophagy activating kinase; UPR: unfolded protein response; UPS: ubiquitin-proteasome system; VCP: valosin containing protein.
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Affiliation(s)
- Jason P Chua
- Department of Neurology, University of Michigan, Ann Arbor, MI, United States
| | - Hortense De Calbiac
- Recherche translationnelle sur les maladies neurologiques, Institut Imagine, UMR-1163 INSERM et Université Paris Descartes, Hôpital Universitaire Necker-Enfants Malades, Paris, France
| | - Edor Kabashi
- Recherche translationnelle sur les maladies neurologiques, Institut Imagine, UMR-1163 INSERM et Université Paris Descartes, Hôpital Universitaire Necker-Enfants Malades, Paris, France
| | - Sami J Barmada
- Department of Neurology, University of Michigan, Ann Arbor, MI, United States
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21
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Tang M, Liu T, Jiang P, Dang R. The interaction between autophagy and neuroinflammation in major depressive disorder: From pathophysiology to therapeutic implications. Pharmacol Res 2021; 168:105586. [PMID: 33812005 DOI: 10.1016/j.phrs.2021.105586] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/19/2021] [Accepted: 03/25/2021] [Indexed: 12/14/2022]
Abstract
The past decade has revealed neuroinflammation as an important mechanism of major depressive disorder (MDD). Nod-like receptors family pyrin domain containing 3 (NLRP3) inflammasome is the key regulator interleukin-1β (IL-1β) maturation, whose activation has been reported in MDD patients and various animal models. Function as a dominant driver of neuroinflammation, NLRP3 bridges the gap between immune activation with stress exposure, and further leads to subsequent occurrence of neuropsychiatric disorders such as MDD. Of note, autophagy is a tightly regulated cellular degradation pathway that removes damaged organelles and intracellular pathogens, and maintains cellular homeostasis from varying insults. Serving as a critical cellular monitoring system, normal functioned autophagy signaling prevents excessive NLRP3 inflammasome activation and subsequent release of IL-1 family cytokines. This review will describe the current understanding of how autophagy regulates NLRP3 inflammasome activity and discuss the implications of this regulation on the pathogenesis of MDD. The extensive crosstalk between autophagy pathway and NLRP3 inflammasome is further discussed, as it is critical for developing new therapeutic strategies for MDD aimed at modulating the neuroinflammatory responses.
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Affiliation(s)
- Mimi Tang
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Ting Liu
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Pei Jiang
- Institute of Clinical Pharmacy, Jining First People's Hospital, Jining Medical University, Jining 272000, China.
| | - Ruili Dang
- Institute of Clinical Pharmacy, Jining First People's Hospital, Jining Medical University, Jining 272000, China.
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22
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Wang X, Sun Y, Peng X, Naqvi SMAS, Yang Y, Zhang J, Chen M, Chen Y, Chen H, Yan H, Wei G, Hong P, Lu Y. The Tumorigenic Effect of Sphingosine Kinase 1 and Its Potential Therapeutic Target. Cancer Control 2020; 27:1073274820976664. [PMID: 33317322 PMCID: PMC8480355 DOI: 10.1177/1073274820976664] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Sphingosine kinase 1 (SPHK1) regulates cell proliferation and survival by converting sphingosine to the signaling mediator sphingosine 1-phosphate (S1P). SPHK1 is widely overexpressed in most cancers, promoting tumor progression and is associated with clinical prognosis. Numerous studies have explored SPHK1 as a promising target for cancer therapy. However, due to insufficient knowledge of SPHK1 oncogenic mechanisms, its inhibitors’ therapeutic potential in preventing and treating cancer still needs further investigation. In this review, we summarized the metabolic balance regulated by the SPHK1/S1P signaling pathway and highlighted the oncogenic mechanisms of SPHK1 via the upregulation of autophagy, proliferation, and survival, migration, angiogenesis and inflammation, and inhibition of apoptosis. Drug candidates targeting SPHK1 were also discussed at the end. This review provides new insights into the oncogenic effect of SPHK1 and sheds light on the future direction for targeting SPHK1 as cancer therapy.
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Affiliation(s)
- Xianwang Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, China
- Laboratory of Oncology, Center for Molecular Medicine, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, China
| | - Yong Sun
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, China
| | - Xiaochun Peng
- Laboratory of Oncology, Center for Molecular Medicine, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, China
| | - Syed Manzar Abbas Shah Naqvi
- Laboratory of Oncology, Center for Molecular Medicine, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, China
| | - Yue Yang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, China
| | - Jing Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, China
| | - Meiwen Chen
- Laboratory of Oncology, Center for Molecular Medicine, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, China
| | - Yuan Chen
- Laboratory of Oncology, Center for Molecular Medicine, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, China
| | - Hongyue Chen
- Laboratory of Oncology, Center for Molecular Medicine, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, China
| | - Huizi Yan
- Laboratory of Oncology, Center for Molecular Medicine, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, China
| | - Guangliang Wei
- Laboratory of Oncology, Center for Molecular Medicine, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, China
| | - Peng Hong
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, Guangdong, China
| | - Yingying Lu
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, Guangdong, China
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23
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Di Pardo A, Pepe G, Capocci L, Marracino F, Amico E, Del Vecchio L, Giova S, Jeong SK, Park BM, Park BD, Maglione V. Treatment with K6PC-5, a selective stimulator of SPHK1, ameliorates intestinal homeostasis in an animal model of Huntington's disease. Neurobiol Dis 2020; 143:105009. [PMID: 32634578 DOI: 10.1016/j.nbd.2020.105009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 06/10/2020] [Accepted: 06/29/2020] [Indexed: 02/08/2023] Open
Abstract
Emerging evidence indicates that Huntington's disease (HD) may be described as multi-organ pathology. In this context, we and others have contributed to demonstrate that the disease is characterized by an impairment of the homeostasis of gastro-intestinal (GI) tract. Sphingolipids represent a class of molecules involved in the regulation and maintenance of different tissues and organs including GI system. In this study, we investigated whether the alteration of Sphingosine-1-phosphate (S1P) metabolism, previously described in human HD brains and animal models, is also detectable peripherally in R6/2 HD mice. Our findings indicate, for the first time, that sphingolipid metabolism is perturbed early in the disease in the intestinal tract of HD mice and, its modulation by K6PC-5, a selective activator of S1P synthesis, preserved intestinal integrity and homeostasis. These results further support the evidence that modulation of sphingolipid pathways may represent a potential therapeutic option in HD and suggest that it has also the potential to counteract the peripheral disturbances which may usually complicate the management of the disease and affect patient's quality of life.
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Affiliation(s)
| | - G Pepe
- IRCCS Neuromed, Pozzilli, Italy
| | | | | | - E Amico
- IRCCS Neuromed, Pozzilli, Italy
| | - L Del Vecchio
- IRCCS Neuromed, Pozzilli, Italy; Unità complessa di radiodiagnostica (U.O.C.) POS, University of Foggia, Foggia, Italy
| | - S Giova
- IRCCS Neuromed, Pozzilli, Italy
| | - S K Jeong
- Department of Cosmetic Science, Seowon University, Cheongju, Republic of Korea
| | - B M Park
- NeoPharm USA Inc., Engelwood Cliffs, NJ, USA
| | - B D Park
- Dr. Raymond Laboratories, Inc, Englewood cliffs, NJ, USA
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24
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Lejault P, Moruno-Manchon JF, Vemu SM, Honarpisheh P, Zhu L, Kim N, Urayama A, Monchaud D, McCullough LD, Tsvetkov AS. Regulation of autophagy by DNA G-quadruplexes. Autophagy 2020; 16:2252-2259. [PMID: 32420812 DOI: 10.1080/15548627.2020.1769991] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Guanine-rich DNA strands can form secondary structures known as G-quadruplexes (G4-DNA or G4s). G4-DNA is important for the regulation of replication and transcription. We recently showed that the expression of Atg7, a gene that is critical for macroautophagy/autophagy, is controlled by G4-DNA in neurons. We demonstrated that the transcription factor SUB1/PC4 and the G4-DNA-specific antibody HF2 bind to a putative G4-DNA motif located in the Atg7 gene. Stabilizing G4-DNA with the G4-ligand pyridostatin (PDS) downregulates Atg7 expression in neurons. Here, we further investigated how G4-DNA in the Atg7 gene is stabilized by PDS. We show that PDS can form 1:1 and 2:1 complexes with the Atg7's G4. We also demonstrate that PDS downregulates the ATG7 protein and the expression of Atg7 in astrocytes as well as in neurons. Together with our previous findings, these data establish a novel G4-DNA-associated mechanism of autophagy regulation at a transcriptional level in neurons and astrocytes.
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Affiliation(s)
- Pauline Lejault
- UBFC Dijon, Institut De Chimie Moléculaire (ICMUB) , Dijon, France
| | - Jose F Moruno-Manchon
- Department of Neurology, The University of Texas McGovern Medical School at Houston , Houston, TX, USA
| | - Sree M Vemu
- Summer Research Program, the University of Texas Medical School at Houston , TX, USA
| | - Pedram Honarpisheh
- Department of Neurology, The University of Texas McGovern Medical School at Houston , Houston, TX, USA.,The University of Texas Graduate School of Biomedical Sciences , Houston, TX, USA
| | - Liang Zhu
- Biostatistics and Epidemiology Research Design Core Center for Clinical and Translational Sciences, The University of Texas McGovern Medical School at Houston , Houston, TX, USA.,Department of Internal Medicine, The University of Texas McGovern Medical School at Houston , Houston, TX, USA
| | - Nayun Kim
- The University of Texas Graduate School of Biomedical Sciences , Houston, TX, USA.,Department of Microbiology and Molecular Genetics, The University of Texas McGovern Medical School at Houston , TX
| | - Akihiko Urayama
- Department of Neurology, The University of Texas McGovern Medical School at Houston , Houston, TX, USA.,The University of Texas Graduate School of Biomedical Sciences , Houston, TX, USA
| | - David Monchaud
- UBFC Dijon, Institut De Chimie Moléculaire (ICMUB) , Dijon, France
| | - Louise D McCullough
- Department of Neurology, The University of Texas McGovern Medical School at Houston , Houston, TX, USA.,The University of Texas Graduate School of Biomedical Sciences , Houston, TX, USA
| | - Andrey S Tsvetkov
- Department of Neurology, The University of Texas McGovern Medical School at Houston , Houston, TX, USA.,The University of Texas Graduate School of Biomedical Sciences , Houston, TX, USA.,UTHealth Consortium on Aging, The University of Texas McGovern Medical School , Houston, TX, USA
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25
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Abstract
Neurodegenerative diseases are, at present, major socio-economic burdens without effective treatments and their increasing prevalence means that these diseases will be a challenge for future generations. Neurodegenerative diseases may differ in etiology and pathology but are often caused by the accumulation of dysfunctional and aggregation-prone proteins. Autophagy, a conserved cellular mechanism, deals with cellular stress and waste product build-up and has been shown to reduce the accumulation of dysfunctional proteins in animal models of neurodegenerative diseases. Historically, progress in understanding the precise function of lipids has traditionally been far behind other biological molecules (like proteins) but emerging works demonstrate the importance of lipids in the autophagy pathway and how the disturbance of lipid metabolism is connected to neurodegeneration. Here we review how altered autophagy and the disturbance of lipid metabolism, particularly of phosphoinositols and sphingolipids, feature in neurodegenerative diseases and address work from the field that suggests that these potentially offer an opportunity of therapeutic intervention.
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Affiliation(s)
- Sergio Hernandez-Diaz
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, 33000, Bordeaux, France.,CNRS, Institut des Maladies Neurodégénératives, UMR 5293, 33000, Bordeaux, France
| | - Sandra-Fausia Soukup
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, 33000, Bordeaux, France.,CNRS, Institut des Maladies Neurodégénératives, UMR 5293, 33000, Bordeaux, France
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26
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Loos B, Klionsky DJ, Du Toit A, Hofmeyr JHS. On the relevance of precision autophagy flux control in vivo - Points of departure for clinical translation. Autophagy 2020; 16:750-762. [PMID: 31679454 PMCID: PMC7138200 DOI: 10.1080/15548627.2019.1687211] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 10/11/2019] [Accepted: 10/28/2019] [Indexed: 12/14/2022] Open
Abstract
Macroautophagy (which we will call autophagy hereafter) is a critical intracellular bulk degradation system that is active at basal rates in eukaryotic cells. This process is embedded in the homeostasis of nutrient availability and cellular metabolic demands, degrading primarily long-lived proteins and specific organelles.. Autophagy is perturbed in many pathologies, and its manipulation to enhance or inhibit this pathway therapeutically has received considerable attention. Although better probes are being developed for a more precise readout of autophagic activity in vitro and increasingly in vivo, many questions remain. These center in particular around the accurate measurement of autophagic flux and its translation from the in vitro to the in vivo environment as well as its clinical application. In this review, we highlight key aspects that appear to contribute to stumbling blocks on the road toward clinical translation and discuss points of departure for reaching some of the desired goals. We discuss techniques that are well aligned with achieving desirable spatiotemporal resolution to gather data on autophagic flux in a multi-scale fashion, to better apply the existing tools that are based on single-cell analysis and to use them in the living organism. We assess how current techniques may be used for the establishment of autophagic flux standards or reference points and consider strategies for a conceptual approach on titrating autophagy inducers based on their effect on autophagic flux . Finally, we discuss potential solutions for inherent controls for autophagy analysis, so as to better discern systemic and tissue-specific autophagic flux in future clinical applications.Abbreviations: GFP: Green fluorescent protein; J: Flux; MAP1LC3/LC3: Microtubule-associated protein 1 light chain 3; nA: Number of autophagosomes; TEM: Transmission electron microscopy; τ: Transition time.
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Affiliation(s)
- Ben Loos
- Department of Physiological Sciences, Faculty of Natural Sciences, University of Stellenbosch, Stellenbosch, South Africa
| | - Daniel J. Klionsky
- Life Sciences Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, USA
| | - Andre Du Toit
- Department of Biochemistry, Faculty of Natural Sciences, University of Stellenbosch, Stellenbosch, South Africa
| | - Jan-Hendrik S. Hofmeyr
- Department of Biochemistry, Faculty of Natural Sciences, University of Stellenbosch, Stellenbosch, South Africa
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27
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Uzor NE, McCullough LD, Tsvetkov AS. Peroxisomal Dysfunction in Neurological Diseases and Brain Aging. Front Cell Neurosci 2020; 14:44. [PMID: 32210766 PMCID: PMC7075811 DOI: 10.3389/fncel.2020.00044] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 02/18/2020] [Indexed: 12/17/2022] Open
Abstract
Peroxisomes exist in most cells, where they participate in lipid metabolism, as well as scavenging the reactive oxygen species (ROS) that are produced as by-products of their metabolic functions. In certain tissues such as the liver and kidneys, peroxisomes have more specific roles, such as bile acid synthesis in the liver and steroidogenesis in the adrenal glands. In the brain, peroxisomes are critically involved in creating and maintaining the lipid content of cell membranes and the myelin sheath, highlighting their importance in the central nervous system (CNS). This review summarizes the peroxisomal lifecycle, then examines the literature that establishes a link between peroxisomal dysfunction, cellular aging, and age-related disorders that affect the CNS. This review also discusses the gap of knowledge in research on peroxisomes in the CNS.
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Affiliation(s)
- Ndidi-Ese Uzor
- Department of Neurobiology and Anatomy, University of Texas McGovern Medical School, Houston, TX, United States
- The University of Texas Graduate School of Biomedical Sciences, Houston, TX, United States
| | - Louise D. McCullough
- The University of Texas Graduate School of Biomedical Sciences, Houston, TX, United States
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX, United States
- UTHealth Consortium on Aging, University of Texas McGovern Medical School, Houston, TX, United States
| | - Andrey S. Tsvetkov
- Department of Neurobiology and Anatomy, University of Texas McGovern Medical School, Houston, TX, United States
- The University of Texas Graduate School of Biomedical Sciences, Houston, TX, United States
- UTHealth Consortium on Aging, University of Texas McGovern Medical School, Houston, TX, United States
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28
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Moruno-Manchon JF, Lejault P, Wang Y, McCauley B, Honarpisheh P, Morales Scheihing DA, Singh S, Dang W, Kim N, Urayama A, Zhu L, Monchaud D, McCullough LD, Tsvetkov AS. Small-molecule G-quadruplex stabilizers reveal a novel pathway of autophagy regulation in neurons. eLife 2020; 9:e52283. [PMID: 32043463 PMCID: PMC7012600 DOI: 10.7554/elife.52283] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 01/07/2020] [Indexed: 12/22/2022] Open
Abstract
Guanine-rich DNA sequences can fold into four-stranded G-quadruplex (G4-DNA) structures. G4-DNA regulates replication and transcription, at least in cancer cells. Here, we demonstrate that, in neurons, pharmacologically stabilizing G4-DNA with G4 ligands strongly downregulates the Atg7 gene. Atg7 is a critical gene for the initiation of autophagy that exhibits decreased transcription with aging. Using an in vitro assay, we show that a putative G-quadruplex-forming sequence (PQFS) in the first intron of the Atg7 gene folds into a G4. An antibody specific to G4-DNA and the G4-DNA-binding protein PC4 bind to the Atg7 PQFS. Mice treated with a G4 stabilizer develop memory deficits. Brain samples from aged mice contain G4-DNA structures that are absent in brain samples from young mice. Overexpressing the G4-DNA helicase Pif1 in neurons exposed to the G4 stabilizer improves phenotypes associated with G4-DNA stabilization. Our findings indicate that G4-DNA is a novel pathway for regulating autophagy in neurons.
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Affiliation(s)
- Jose F Moruno-Manchon
- Department of Neurobiology and AnatomyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - Pauline Lejault
- Institut de Chimie Moléculaire (ICMUB), UBFC Dijon, CNRS UMR6302DijonFrance
| | - Yaoxuan Wang
- Department of Neurobiology and AnatomyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - Brenna McCauley
- Huffington Center on AgingBaylor College of MedicineHoustonUnited States
| | - Pedram Honarpisheh
- Department of NeurologyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
- The University of Texas Graduate School of Biomedical SciencesHoustonUnited States
| | - Diego A Morales Scheihing
- Department of NeurologyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - Shivani Singh
- Department of Microbiology and Molecular GeneticsThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - Weiwei Dang
- Huffington Center on AgingBaylor College of MedicineHoustonUnited States
| | - Nayun Kim
- Department of Microbiology and Molecular GeneticsThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - Akihiko Urayama
- Department of NeurologyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
- The University of Texas Graduate School of Biomedical SciencesHoustonUnited States
| | - Liang Zhu
- Biostatistics and Epidemiology Research Design Core Center for Clinical and Translational SciencesThe University of Texas McGovern Medical School at HoustonHoustonUnited States
- Department of Internal MedicineThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - David Monchaud
- Institut de Chimie Moléculaire (ICMUB), UBFC Dijon, CNRS UMR6302DijonFrance
| | - Louise D McCullough
- Department of NeurologyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
- The University of Texas Graduate School of Biomedical SciencesHoustonUnited States
| | - Andrey S Tsvetkov
- Department of Neurobiology and AnatomyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
- The University of Texas Graduate School of Biomedical SciencesHoustonUnited States
- UTHealth Consortium on AgingThe University of Texas McGovern Medical School at HoustonHoustonUnited States
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29
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Sung K, Jimenez-Sanchez M. Autophagy in Astrocytes and its Implications in Neurodegeneration. J Mol Biol 2020; 432:2605-2621. [PMID: 31931011 DOI: 10.1016/j.jmb.2019.12.041] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 12/12/2019] [Accepted: 12/18/2019] [Indexed: 12/12/2022]
Abstract
Autophagy is a major degradation pathway where double-membrane vesicles called autophagosomes deliver cytoplasmic content to the lysosome. Increasing evidence suggests that autophagy dysfunction contributes to the pathogenesis of neurodegenerative diseases. In addition, misfolded proteins that accumulate in these diseases and constitute a common pathological hallmark are substrates for autophagic degradation. Astrocytes, a major type of glial cells, are emerging as a critical component in most neurodegenerative diseases. This review will summarize the recent efforts to investigate the role that autophagy plays in astrocytes in the context of neurodegenerative diseases. While the field has mostly focused on the implications of autophagy in neurons, autophagy may also be involved in the clearance of disease-related proteins in astrocytes as well as in maintaining astrocyte function, which could impact the cell autonomous and non-cell autonomous contribution of astrocytes to neurodegeneration.
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Affiliation(s)
- Katherine Sung
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, 5 Cutcombe Road, London, SE5 9RX, UK
| | - Maria Jimenez-Sanchez
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, 5 Cutcombe Road, London, SE5 9RX, UK.
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30
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Autophagy in the Immunosuppressive Perivascular Microenvironment of Glioblastoma. Cancers (Basel) 2019; 12:cancers12010102. [PMID: 31906065 PMCID: PMC7016956 DOI: 10.3390/cancers12010102] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/23/2019] [Accepted: 12/27/2019] [Indexed: 02/07/2023] Open
Abstract
Glioblastoma (GB) has been shown to up-regulate autophagy with anti- or pro-oncogenic effects. Recently, our group has shown how GB cells aberrantly up-regulate chaperone-mediated autophagy (CMA) in pericytes of peritumoral areas to modulate their immune function through cell-cell interaction and in the tumor’s own benefit. Thus, to understand GB progression, the effect that GB cells could have on autophagy of immune cells that surround the tumor needs to be deeply explored. In this review, we summarize all the latest evidence of several molecular and cellular immunosuppressive mechanisms in the perivascular tumor microenvironment. This immunosuppression has been reported to facilitate GB progression and may be differently modulated by several types of autophagy as a critical point to be considered for therapeutic interventions.
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31
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Kulkarni A, Dong A, Kulkarni VV, Chen J, Laxton O, Anand A, Maday S. Differential regulation of autophagy during metabolic stress in astrocytes and neurons. Autophagy 2019; 16:1651-1667. [PMID: 31876243 DOI: 10.1080/15548627.2019.1703354] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Macroautophagy/autophagy is a key homeostatic process that targets cytoplasmic components to the lysosome for breakdown and recycling. Autophagy plays critical roles in glia and neurons that affect development, functionality, and viability of the nervous system. The mechanisms that regulate autophagy in glia and neurons, however, are poorly understood. Here, we define the molecular underpinnings of autophagy in primary cortical astrocytes in response to metabolic stress, and perform a comparative study in primary hippocampal neurons. We find that inducing metabolic stress by nutrient deprivation or pharmacological inhibition of MTOR (mechanistic target of rapamycin kinase) robustly activates autophagy in astrocytes. While both paradigms of metabolic stress dampen MTOR signaling, they affect the autophagy pathway differently. Further, we find that starvation-induced autophagic flux is dependent on the buffering system of the starvation solution. Lastly, starvation conditions that strongly activate autophagy in astrocytes have less pronounced effects on autophagy in neurons. Combined, our study reveals the complexity of regulating autophagy in different paradigms of metabolic stress, as well as in different cell types of the brain. Our findings raise important implications for how neurons and glia may collaborate to maintain homeostasis in the brain. ABBREVIATIONS ACSF: artificial cerebrospinal fluid; baf A1: bafilomycin A1; EBSS: earle's balanced salt solution; GFAP: glial fibrillary acidic protein; Glc: glucose; GM: glial media; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; p-RPS6: phospho-RPS6; p-ULK1: phospho-ULK1; RPS6: ribosomal protein S6; SQSTM1/p62: sequestosome 1; ULK1: unc-51-like kinase 1.
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Affiliation(s)
- Aditi Kulkarni
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania , Philadelphia, PA 19104, USA
| | - Audrey Dong
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania , Philadelphia, PA 19104, USA
| | - Vineet Vinay Kulkarni
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania , Philadelphia, PA 19104, USA
| | - Jessica Chen
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania , Philadelphia, PA 19104, USA
| | - Olivia Laxton
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania , Philadelphia, PA 19104, USA
| | - Anip Anand
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania , Philadelphia, PA 19104, USA
| | - Sandra Maday
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania , Philadelphia, PA 19104, USA
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32
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Grassi S, Mauri L, Prioni S, Cabitta L, Sonnino S, Prinetti A, Giussani P. Sphingosine 1-Phosphate Receptors and Metabolic Enzymes as Druggable Targets for Brain Diseases. Front Pharmacol 2019; 10:807. [PMID: 31427962 PMCID: PMC6689979 DOI: 10.3389/fphar.2019.00807] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 06/21/2019] [Indexed: 12/12/2022] Open
Abstract
The central nervous system is characterized by a high content of sphingolipids and by a high diversity in terms of different structures. Stage- and cell-specific sphingolipid metabolism and expression are crucial for brain development and maintenance toward adult age. On the other hand, deep dysregulation of sphingolipid metabolism, leading to altered sphingolipid pattern, is associated with the majority of neurological and neurodegenerative diseases, even those totally lacking a common etiological background. Thus, sphingolipid metabolism has always been regarded as a promising pharmacological target for the treatment of brain disorders. However, any therapeutic hypothesis applied to complex amphipathic sphingolipids, components of cellular membranes, has so far failed probably because of the high regional complexity and specificity of the different biological roles of these structures. Simpler sphingosine-based lipids, including ceramide and sphingosine 1-phosphate, are important regulators of brain homeostasis, and, thanks to the relative simplicity of their metabolic network, they seem a feasible druggable target for the treatment of brain diseases. The enzymes involved in the control of the levels of bioactive sphingoids, as well as the receptors engaged by these molecules, have increasingly allured pharmacologists and clinicians, and eventually fingolimod, a functional antagonist of sphingosine 1-phosphate receptors with immunomodulatory properties, was approved for the therapy of relapsing-remitting multiple sclerosis. Considering the importance of neuroinflammation in many other brain diseases, we would expect an extension of the use of such analogs for the treatment of other ailments in the future. Nevertheless, many aspects other than neuroinflammation are regulated by bioactive sphingoids in healthy brain and dysregulated in brain disease. In this review, we are addressing the multifaceted possibility to address the metabolism and biology of bioactive sphingosine 1-phosphate as novel targets for the development of therapeutic paradigms and the discovery of new drugs.
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Affiliation(s)
- Sara Grassi
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Laura Mauri
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Simona Prioni
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Livia Cabitta
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Sandro Sonnino
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Alessandro Prinetti
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Paola Giussani
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
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33
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Di Pardo A, Pepe G, Castaldo S, Marracino F, Capocci L, Amico E, Madonna M, Giova S, Jeong SK, Park BM, Park BD, Maglione V. Stimulation of Sphingosine Kinase 1 (SPHK1) Is Beneficial in a Huntington's Disease Pre-clinical Model. Front Mol Neurosci 2019; 12:100. [PMID: 31068790 PMCID: PMC6491579 DOI: 10.3389/fnmol.2019.00100] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/03/2019] [Indexed: 12/19/2022] Open
Abstract
Although several agents have been identified to provide therapeutic benefits in Huntington disease (HD), the number of conventionally used treatments remains limited and only symptomatic. Thus, it is plausible that the need to identify new therapeutic targets for the development of alternative and more effective treatments is becoming increasingly urgent. Recently, the sphingosine-1-phosphate (S1P) axis has been reported to be a valid potential novel molecular target for therapy development in HD. Modulation of aberrant metabolism of S1P in HD has been proved to exert neuroprotective action in vitro settings including human HD iPSC-derived neurons. In this study, we investigated whether promoting S1P production by stimulating Sphingosine Kinase 1 (SPHK1) by the selective activator, K6PC-5, may have therapeutic benefit in vivo in R6/2 HD mouse model. Our findings indicate that chronic administration of 0.05 mg/kg K6PC-5 exerted an overall beneficial effect in R6/2 mice. It significantly slowed down the progressive motor deficit associated with disease progression, modulated S1P metabolism, evoked the activation of pro-survival pathways and markedly reduced the toxic mutant huntingtin (mHtt) aggregation. These results suggest that K6PC-5 may represent a future therapeutic option in HD and may potentially counteract the perturbed brain function induced by deregulated S1P pathways.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Se Kyoo Jeong
- Department of Cosmetic Science, Seowon University, Cheongju, South Korea
| | - Bu-Mahn Park
- NeoPharm USA Inc., Engelwood Cliffs, NJ, United States
| | - Byeong Deog Park
- Dr. Raymond Laboratories, Inc., Englewood Cliffs, NJ, United States
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Wang G, Bieberich E. Sphingolipids in neurodegeneration (with focus on ceramide and S1P). Adv Biol Regul 2018; 70:51-64. [PMID: 30287225 PMCID: PMC6251739 DOI: 10.1016/j.jbior.2018.09.013] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 09/20/2018] [Accepted: 09/21/2018] [Indexed: 04/14/2023]
Abstract
For many decades, research on sphingolipids associated with neurodegenerative disease focused on alterations in glycosphingolipids, particularly glycosylceramides (cerebrosides), sulfatides, and gangliosides. This seemed quite natural since many of these glycolipids are constituents of myelin and accumulated in lipid storage diseases (sphingolipidoses) resulting from enzyme deficiencies in glycolipid metabolism. With the advent of recognizing ceramide and its derivative, sphingosine-1-phosphate (S1P), as key players in lipid cell signaling and regulation of cell death and survival, research focus shifted toward these two sphingolipids. Ceramide and S1P are invoked in a plethora of cell biological processes participating in neurodegeneration such as ER stress, autophagy, dysregulation of protein and lipid transport, exosome secretion and neurotoxic protein spreading, neuroinflammation, and mitochondrial dysfunction. Hence, it is timely to discuss various functions of ceramide and S1P in neurodegenerative disease and to define sphingolipid metabolism and cell signaling pathways as potential targets for therapy.
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Affiliation(s)
- Guanghu Wang
- Department of Physiology, University of Kentucky, Lexington, KY, USA
| | - Erhard Bieberich
- Department of Physiology, University of Kentucky, Lexington, KY, USA.
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