1
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Ferdaus MZ, Koumangoye RB, Welling PA, Delpire E. Kinase Scaffold Cab39 Is Necessary for Phospho-Activation of the Thiazide-Sensitive NCC. Hypertension 2024; 81:801-810. [PMID: 38258567 PMCID: PMC10954405 DOI: 10.1161/hypertensionaha.123.22464] [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: 11/26/2023] [Accepted: 01/11/2024] [Indexed: 01/24/2024]
Abstract
BACKGROUND Potassium regulates the WNK (with no lysine kinase)-SPAK (STE20/SPS1-related proline/alanine-rich kinase) signaling axis, which in turn controls the phosphorylation and activation of the distal convoluted tubule thiazide-sensitive NCC (sodium-chloride cotransporter) for sodium-potassium balance. Although their roles in the kidney have not been investigated, it has been postulated that Cab39 (calcium-binding protein 39) or Cab39l (Cab39-like) is required for SPAK/OSR1 (oxidative stress response 1) activation. This study demonstrates how they control the WNK-SPAK/OSR1-NCC pathway. METHODS We created a global knockout of Cab39l and a tamoxifen-inducible, NCC-driven, Cab39 knockout. The 2 lines were crossed to generate Cab39-DKO (Cab39 double knockout) animals. Mice were studied under control and low-potassium diet, which activates WNK-SPAK/OSR1-NCC phosphorylation. Western blots were used to assess the expression and phosphorylation of proteins. Blood and urine electrolytes were measured to test for compromised NCC function. Immunofluorescence studies were conducted to localize SPAK and OSR1. RESULTS Both Cab39l and Cab39 are expressed in distal convoluted tubule, and only the elimination of both leads to a striking absence of NCC phosphorylation. Cab39-DKO mice exhibited a loss-of-NCC function, like in Gitelman syndrome. In contrast to the apical membrane colocalization of SPAK with NCC in wild-type mice, SPAK and OSR1 become confined to intracellular puncta in the Cab39-DKO mice. CONCLUSIONS In the absence of Cab39 proteins, NCC cannot be phosphorylated, resulting in a Gitelman-like phenotype. Cab39 proteins function to localize SPAK at the apical membrane with NCC, reminiscent of the Cab39 yeast homolog function, translocating kinases during cytokinesis.
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Affiliation(s)
- Mohammed Z Ferdaus
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN (M.Z.F, R.B.K., E.D.)
| | - Rainelli B Koumangoye
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN (M.Z.F, R.B.K., E.D.)
| | - Paul A Welling
- Division of Nephrology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD (P.A.W.)
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN (M.Z.F, R.B.K., E.D.)
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2
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Qian Y, Galan-Cobo A, Guijarro I, Dang M, Molkentine D, Poteete A, Zhang F, Wang Q, Wang J, Parra E, Panda A, Fang J, Skoulidis F, Wistuba II, Verma S, Merghoub T, Wolchok JD, Wong KK, DeBerardinis RJ, Minna JD, Vokes NI, Meador CB, Gainor JF, Wang L, Reuben A, Heymach JV. MCT4-dependent lactate secretion suppresses antitumor immunity in LKB1-deficient lung adenocarcinoma. Cancer Cell 2023; 41:1363-1380.e7. [PMID: 37327788 PMCID: PMC11161201 DOI: 10.1016/j.ccell.2023.05.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 05/15/2023] [Accepted: 05/24/2023] [Indexed: 06/18/2023]
Abstract
Inactivating STK11/LKB1 mutations are genomic drivers of primary resistance to immunotherapy in KRAS-mutated lung adenocarcinoma (LUAD), although the underlying mechanisms remain unelucidated. We find that LKB1 loss results in enhanced lactate production and secretion via the MCT4 transporter. Single-cell RNA profiling of murine models indicates that LKB1-deficient tumors have increased M2 macrophage polarization and hypofunctional T cells, effects that could be recapitulated by the addition of exogenous lactate and abrogated by MCT4 knockdown or therapeutic blockade of the lactate receptor GPR81 expressed on immune cells. Furthermore, MCT4 knockout reverses the resistance to PD-1 blockade induced by LKB1 loss in syngeneic murine models. Finally, tumors from STK11/LKB1 mutant LUAD patients demonstrate a similar phenotype of enhanced M2-macrophages polarization and hypofunctional T cells. These data provide evidence that lactate suppresses antitumor immunity and therapeutic targeting of this pathway is a promising strategy to reversing immunotherapy resistance in STK11/LKB1 mutant LUAD.
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Affiliation(s)
- Yu Qian
- Department of Thoracic/Head and Neck Medical Oncology, Houston, TX, USA
| | - Ana Galan-Cobo
- Department of Thoracic/Head and Neck Medical Oncology, Houston, TX, USA
| | - Irene Guijarro
- Department of Thoracic/Head and Neck Medical Oncology, Houston, TX, USA
| | - Minghao Dang
- Department of Genomic Medicine, Houston, TX, USA
| | - David Molkentine
- Department of Thoracic/Head and Neck Medical Oncology, Houston, TX, USA
| | - Alissa Poteete
- Department of Thoracic/Head and Neck Medical Oncology, Houston, TX, USA
| | - Fahao Zhang
- Department of Thoracic/Head and Neck Medical Oncology, Houston, TX, USA
| | - Qi Wang
- Department of Bioinformatics and Computational Biology, Houston, TX, USA
| | - Jing Wang
- Department of Bioinformatics and Computational Biology, Houston, TX, USA
| | - Edwin Parra
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | | | - Jacy Fang
- Broad Institute of MIT and Harvard, Cambridge, MA, USA; Center for Cancer Research, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | | | - Ignacio I Wistuba
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Svena Verma
- Ludwig Collaborative and Swim Across America Laboratory, MSK, New York, NY, USA
| | - Taha Merghoub
- Ludwig Collaborative and Swim Across America Laboratory, MSK, New York, NY, USA
| | - Jedd D Wolchok
- Ludwig Collaborative and Swim Across America Laboratory, MSK, New York, NY, USA
| | - Kwok-Kin Wong
- Division of Hematology & Medical Oncology, Laura and Isaac Perlmutter Cancer Center, New York University Langone Medical Center, New York, NY, USA
| | - Ralph J DeBerardinis
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - John D Minna
- Hamon Center for Therapeutic Oncology Research, UT Southwestern Medical Center, Dallas, TX, USA
| | - Natalie I Vokes
- Department of Thoracic/Head and Neck Medical Oncology, Houston, TX, USA
| | - Catherine B Meador
- Department of Medicine, Division of Hematology/Oncology, Massachusetts General Hospital Cancer Center, Boston, MA, USA; Center for Thoracic Cancers, Massachusetts General Hospital, Boston, MA, USA
| | - Justin F Gainor
- Center for Cancer Research, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA; Center for Thoracic Cancers, Massachusetts General Hospital, Boston, MA, USA
| | - Linghua Wang
- Department of Genomic Medicine, Houston, TX, USA
| | - Alexandre Reuben
- Department of Thoracic/Head and Neck Medical Oncology, Houston, TX, USA
| | - John V Heymach
- Department of Thoracic/Head and Neck Medical Oncology, Houston, TX, USA.
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3
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Silva B, Mantha OL, Schor J, Pascual A, Plaçais PY, Pavlowsky A, Preat T. Glia fuel neurons with locally synthesized ketone bodies to sustain memory under starvation. Nat Metab 2022; 4:213-224. [PMID: 35177854 PMCID: PMC8885408 DOI: 10.1038/s42255-022-00528-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 01/07/2022] [Indexed: 11/15/2022]
Abstract
During starvation, mammalian brains can adapt their metabolism, switching from glucose to alternative peripheral fuel sources. In the Drosophila starved brain, memory formation is subject to adaptative plasticity, but whether this adaptive plasticity relies on metabolic adaptation remains unclear. Here we show that during starvation, neurons of the fly olfactory memory centre import and use ketone bodies (KBs) as an energy substrate to sustain aversive memory formation. We identify local providers within the brain, the cortex glia, that use their own lipid store to synthesize KBs before exporting them to neurons via monocarboxylate transporters. Finally, we show that the master energy sensor AMP-activated protein kinase regulates both lipid mobilization and KB export in cortex glia. Our data provide a general schema of the metabolic interactions within the brain to support memory when glucose is scarce.
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Affiliation(s)
- Bryon Silva
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, Paris, France
| | - Olivier L Mantha
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, Paris, France
- INSERM UMR1069 'Nutrition, Croissance et Cancer', Tours, France
| | - Johann Schor
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, Paris, France
| | - Alberto Pascual
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain
| | - Pierre-Yves Plaçais
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, Paris, France
| | - Alice Pavlowsky
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, Paris, France.
| | - Thomas Preat
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, Paris, France.
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4
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Marzano M, Herzmann S, Elsbroek L, Sanal N, Tarbashevich K, Raz E, Krahn MP, Rumpf S. AMPK adapts metabolism to developmental energy requirement during dendrite pruning in Drosophila. Cell Rep 2021; 37:110024. [PMID: 34788610 DOI: 10.1016/j.celrep.2021.110024] [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: 03/15/2021] [Revised: 07/30/2021] [Accepted: 10/28/2021] [Indexed: 10/19/2022] Open
Abstract
To reshape neuronal connectivity in adult stages, Drosophila sensory neurons prune their dendrites during metamorphosis using a genetic degeneration program that is induced by the steroid hormone ecdysone. Metamorphosis is a nonfeeding stage that imposes metabolic constraints on development. We find that AMP-activated protein kinase (AMPK), a regulator of energy homeostasis, is cell-autonomously required for dendrite pruning. AMPK is activated by ecdysone and promotes oxidative phosphorylation and pyruvate usage, likely to enable neurons to use noncarbohydrate metabolites such as amino acids for energy production. Loss of AMPK or mitochondrial deficiency causes specific defects in pruning factor translation and the ubiquitin-proteasome system. Our findings distinguish pruning from pathological neurite degeneration, which is often induced by defects in energy production, and highlight how metabolism is adapted to fit energy-costly developmental transitions.
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Affiliation(s)
- Marco Marzano
- Institute for Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Svende Herzmann
- Institute for Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Leonardo Elsbroek
- Institute for Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Neeraja Sanal
- Institute for Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Katsiaryna Tarbashevich
- Institute of Cell Biology, Center for Molecular Biology of Inflammation, University of Münster, 48149 Münster, Germany
| | - Erez Raz
- Institute of Cell Biology, Center for Molecular Biology of Inflammation, University of Münster, 48149 Münster, Germany
| | - Michael P Krahn
- Department of Medical Cell Biology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Sebastian Rumpf
- Institute for Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany.
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5
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Glial Metabolic Rewiring Promotes Axon Regeneration and Functional Recovery in the Central Nervous System. Cell Metab 2020; 32:767-785.e7. [PMID: 32941799 PMCID: PMC7642184 DOI: 10.1016/j.cmet.2020.08.015] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 07/07/2020] [Accepted: 08/26/2020] [Indexed: 12/25/2022]
Abstract
Axons in the mature central nervous system (CNS) fail to regenerate after axotomy, partly due to the inhibitory environment constituted by reactive glial cells producing astrocytic scars, chondroitin sulfate proteoglycans, and myelin debris. We investigated this inhibitory milieu, showing that it is reversible and depends on glial metabolic status. We show that glia can be reprogrammed to promote morphological and functional regeneration after CNS injury in Drosophila via increased glycolysis. This enhancement is mediated by the glia derived metabolites: L-lactate and L-2-hydroxyglutarate (L-2HG). Genetically/pharmacologically increasing or reducing their bioactivity promoted or impeded CNS axon regeneration. L-lactate and L-2HG from glia acted on neuronal metabotropic GABAB receptors to boost cAMP signaling. Local application of L-lactate to injured spinal cord promoted corticospinal tract axon regeneration, leading to behavioral recovery in adult mice. Our findings revealed a metabolic switch to circumvent the inhibition of glia while amplifying their beneficial effects for treating CNS injuries.
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6
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Burger CA, Alevy J, Casasent AK, Jiang D, Albrecht NE, Liang JH, Hirano AA, Brecha NC, Samuel MA. LKB1 coordinates neurite remodeling to drive synapse layer emergence in the outer retina. eLife 2020; 9:e56931. [PMID: 32378514 PMCID: PMC7237215 DOI: 10.7554/elife.56931] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 04/11/2020] [Indexed: 12/04/2022] Open
Abstract
Structural changes in pre and postsynaptic neurons that accompany synapse formation often temporally and spatially overlap. Thus, it has been difficult to resolve which processes drive patterned connectivity. To overcome this, we use the laminated outer murine retina. We identify the serine/threonine kinase LKB1 as a key driver of synapse layer emergence. The absence of LKB1 in the retina caused a marked mislocalization and delay in synapse layer formation. In parallel, LKB1 modulated postsynaptic horizontal cell refinement and presynaptic photoreceptor axon growth. Mislocalized horizontal cell processes contacted aberrant cone axons in LKB1 mutants. These defects coincided with altered synapse protein organization, and horizontal cell neurites were misdirected to ectopic synapse protein regions. Together, these data suggest that LKB1 instructs the timing and location of connectivity in the outer retina via coordinate regulation of pre and postsynaptic neuron structure and the localization of synapse-associated proteins.
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Affiliation(s)
- Courtney A Burger
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Jonathan Alevy
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Anna K Casasent
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Danye Jiang
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Nicholas E Albrecht
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Justine H Liang
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Arlene A Hirano
- Department of Neurobiology, David Geffen School of Medicine at UCLALos AngelesUnited States
- United States Veterans Administration Greater Los Angeles Healthcare SystemLos AngelesUnited States
| | - Nicholas C Brecha
- Department of Neurobiology, David Geffen School of Medicine at UCLALos AngelesUnited States
- United States Veterans Administration Greater Los Angeles Healthcare SystemLos AngelesUnited States
| | - Melanie A Samuel
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
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7
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González-Gutiérrez A, Ibacache A, Esparza A, Barros LF, Sierralta J. Neuronal lactate levels depend on glia-derived lactate during high brain activity in Drosophila. Glia 2019; 68:1213-1227. [PMID: 31876077 DOI: 10.1002/glia.23772] [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] [Received: 09/02/2019] [Revised: 12/10/2019] [Accepted: 12/10/2019] [Indexed: 01/13/2023]
Abstract
Lactate/pyruvate transport between glial cells and neurons is thought to play an important role in how brain cells sustain the high-energy demand that neuronal activity requires. However, the in vivo mechanisms and characteristics that underlie the transport of monocarboxylates are poorly described. Here, we use Drosophila expressing genetically encoded FRET sensors to provide an ex vivo characterization of the transport of monocarboxylates in motor neurons and glial cells from the larval ventral nerve cord. We show that lactate/pyruvate transport in glial cells is coupled to protons and is more efficient than in neurons. Glial cells maintain higher levels of intracellular lactate generating a positive gradient toward neurons. Interestingly, during high neuronal activity, raised lactate in motor neurons is dependent on transfer from glial cells mediated in part by the previously described monocarboxylate transporter Chaski, providing support for in vivo glia-to-neuron lactate shuttling during neuronal activity.
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Affiliation(s)
- Andrés González-Gutiérrez
- Department of Neuroscience and Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Andrés Ibacache
- Department of Neuroscience and Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Andrés Esparza
- Department of Neuroscience and Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | | | - Jimena Sierralta
- Department of Neuroscience and Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
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8
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Kalinin S, Meares GP, Lin SX, Pietruczyk EA, Saher G, Spieth L, Nave KA, Boullerne AI, Lutz SE, Benveniste EN, Feinstein DL. Liver kinase B1 depletion from astrocytes worsens disease in a mouse model of multiple sclerosis. Glia 2019; 68:600-616. [PMID: 31664743 PMCID: PMC7337013 DOI: 10.1002/glia.23742] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 09/19/2019] [Accepted: 10/05/2019] [Indexed: 12/15/2022]
Abstract
Liver kinase B1 (LKB1) is a ubiquitously expressed kinase involved in the regulation of cell metabolism, growth, and inflammatory activation. We previously reported that a single nucleotide polymorphism in the gene encoding LKB1 is a risk factor for multiple sclerosis (MS). Since astrocyte activation and metabolic function have important roles in regulating neuroinflammation and neuropathology, we examined the serine/threonine kinase LKB1 in astrocytes in a chronic experimental autoimmune encephalomyelitis mouse model of MS. To reduce LKB1, a heterozygous astrocyte-selective conditional knockout (het-cKO) model was used. While disease incidence was similar, disease severity was worsened in het-cKO mice. RNAseq analysis identified Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enriched in het-cKO mice relating to mitochondrial function, confirmed by alterations in mitochondrial complex proteins and reductions in mRNAs related to astrocyte metabolism. Enriched pathways included major histocompatibility class II genes, confirmed by increases in MHCII protein in spinal cord and cerebellum of het-cKO mice. We observed increased numbers of CD4+ Th17 cells and increased neuronal damage in spinal cords of het-cKO mice, associated with reduced expression of choline acetyltransferase, accumulation of immunoglobulin-γ, and reduced expression of factors involved in motor neuron survival. In vitro, LKB1-deficient astrocytes showed reduced metabolic function and increased inflammatory activation. These data suggest that metabolic dysfunction in astrocytes, in this case due to LKB1 deficiency, can exacerbate demyelinating disease by loss of metabolic support and increase in the inflammatory environment.
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Affiliation(s)
- Sergey Kalinin
- Department of Anesthesiology, University of Illinois, Chicago, Illinois
| | - Gordon P Meares
- Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, West Virginia
| | - Shao Xia Lin
- Department of Anesthesiology, University of Illinois, Chicago, Illinois
| | | | - Gesine Saher
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Gottingen, Germany
| | - Lena Spieth
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Gottingen, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Gottingen, Germany
| | - Anne I Boullerne
- Department of Anesthesiology, University of Illinois, Chicago, Illinois
| | - Sarah E Lutz
- Department of Anatomy and Cell Biology, University of Illinois, Chicago, Illinois
| | - Etty N Benveniste
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Douglas L Feinstein
- Department of Anesthesiology, University of Illinois, Chicago, Illinois.,Department of Veterans Affairs, Jesse Brown VA Medical Center, Chicago, Illinois
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9
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Mosquitoes as Arbovirus Vectors: From Species Identification to Vector Competence. PARASITOLOGY RESEARCH MONOGRAPHS 2018. [PMCID: PMC7122353 DOI: 10.1007/978-3-319-94075-5_9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Mosquitoes and other arthropods transmit a large number of medically important pathogens, in particular viruses. These arthropod-borne viruses (arboviruses) include a wide variety of RNA viruses belonging to the Flaviviridae family (West Nile virus (WNV), Usutu virus (USUV), Dengue virus (DENV), Japanese encephalitis virus (JEV), Zika virus (ZIKV)), the Togaviridae family (Chikungunya virus (CHIKV)), and Bunyavirales order (Rift Valley fever virus (RVFV)) (please refer also to Table 9.1). Arboviral transmission to humans and livestock constitutes a major threat to public health and economy as illustrated by the emergence of ZIKV in the Americas, RVFV outbreaks in Africa, and the worldwide outbreaks of DENV. To answer the question if those viral pathogens also pose a risk to Europe, we need to first answer the key questions (summarized in Fig. 9.1):Who could contribute to such an outbreak? Information about mosquito species resident or imported, potential hosts and viruses able to infect vectors and hosts in Germany is needed. Where would competent mosquito species meet favorable conditions for transmission? Information on the minimum requirements for efficient replication of the virus in a given vector species and subsequent transmission is needed. How do viruses and vectors interact to facilitate transmission? Information on the vector immunity, vector physiology, vector genetics, and vector microbiomes is needed.
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10
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Liu L, MacKenzie KR, Putluri N, Maletić-Savatić M, Bellen HJ. The Glia-Neuron Lactate Shuttle and Elevated ROS Promote Lipid Synthesis in Neurons and Lipid Droplet Accumulation in Glia via APOE/D. Cell Metab 2017; 26:719-737.e6. [PMID: 28965825 PMCID: PMC5677551 DOI: 10.1016/j.cmet.2017.08.024] [Citation(s) in RCA: 306] [Impact Index Per Article: 43.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 06/21/2017] [Accepted: 08/30/2017] [Indexed: 01/04/2023]
Abstract
Elevated reactive oxygen species (ROS) induce the formation of lipids in neurons that are transferred to glia, where they form lipid droplets (LDs). We show that glial and neuronal monocarboxylate transporters (MCTs), fatty acid transport proteins (FATPs), and apolipoproteins are critical for glial LD formation. MCTs enable glia to secrete and neurons to absorb lactate, which is converted to pyruvate and acetyl-CoA in neurons. Lactate metabolites provide a substrate for synthesis of fatty acids, which are processed and transferred to glia by FATP and apolipoproteins. In the presence of high ROS, inhibiting lactate transfer or lowering FATP or apolipoprotein levels decreases glial LD accumulation in flies and in primary mouse glial-neuronal cultures. We show that human APOE can substitute for a fly glial apolipoprotein and that APOE4, an Alzheimer's disease susceptibility allele, is impaired in lipid transport and promotes neurodegeneration, providing insights into disease mechanisms.
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Affiliation(s)
- Lucy Liu
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Kevin R MacKenzie
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, TX 77030, USA; Center for Drug Discovery, Baylor College of Medicine, Houston, TX 77030, USA
| | - Nagireddy Putluri
- Department of Molecular and Cellular Biology and Advanced Technology Cor, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mirjana Maletić-Savatić
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA
| | - Hugo J Bellen
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Baylor College of Medicine, Houston, TX 77030, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA.
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11
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Raja E, Tzavlaki K, Vuilleumier R, Edlund K, Kahata K, Zieba A, Morén A, Watanabe Y, Voytyuk I, Botling J, Söderberg O, Micke P, Pyrowolakis G, Heldin CH, Moustakas A. The protein kinase LKB1 negatively regulates bone morphogenetic protein receptor signaling. Oncotarget 2016; 7:1120-43. [PMID: 26701726 PMCID: PMC4811448 DOI: 10.18632/oncotarget.6683] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 12/08/2015] [Indexed: 01/24/2023] Open
Abstract
The protein kinase LKB1 regulates cell metabolism and growth and is implicated in intestinal and lung cancer. Bone morphogenetic protein (BMP) signaling regulates cell differentiation during development and tissue homeostasis. We demonstrate that LKB1 physically interacts with BMP type I receptors and requires Smad7 to promote downregulation of the receptor. Accordingly, LKB1 suppresses BMP-induced osteoblast differentiation and affects BMP signaling in Drosophila wing longitudinal vein morphogenesis. LKB1 protein expression and Smad1 phosphorylation analysis in a cohort of non-small cell lung cancer patients demonstrated a negative correlation predominantly in a subset enriched in adenocarcinomas. Lung cancer patient data analysis indicated strong correlation between LKB1 loss-of-function mutations and high BMP2 expression, and these two events further correlated with expression of a gene subset functionally linked to apoptosis and migration. This new mechanism of BMP receptor regulation by LKB1 has ramifications in physiological organogenesis and disease.
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Affiliation(s)
- Erna Raja
- Ludwig Institute for Cancer Research, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Kalliopi Tzavlaki
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Robin Vuilleumier
- BIOSS, Centre for Biological Signaling Studies and Institute for Biology I, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Karolina Edlund
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Kaoru Kahata
- Ludwig Institute for Cancer Research, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Agata Zieba
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Anita Morén
- Ludwig Institute for Cancer Research, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Yukihide Watanabe
- Ludwig Institute for Cancer Research, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Iryna Voytyuk
- Ludwig Institute for Cancer Research, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Johan Botling
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Ola Söderberg
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Patrick Micke
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - George Pyrowolakis
- BIOSS, Centre for Biological Signaling Studies and Institute for Biology I, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Carl-Henrik Heldin
- Ludwig Institute for Cancer Research, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Aristidis Moustakas
- Ludwig Institute for Cancer Research, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.,Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
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Abstract
Over the last two decades, several genes have been identified that appear to play a role in the regulation of energy homeostasis and body weight. For a small subset of them, a reduction or an absence of expression confers a resistance to the development of obesity. Recently, a knockin mouse for a member of the monocarboxylate transporter (MCT) family, MCT1, was demonstrated to exhibit a typical phenotype of resistance to diet-induced obesity and a protection from its associated metabolic perturbations. Such findings point out at MCTs as putatively new therapeutic targets in the context of obesity. Here, we will review what is known about MCTs and their possible metabolic roles in different organs and tissues. Based on the description of the phenotype of the MCT1 knockin mouse, we will also provide some insights about their putative roles in weight gain regulation.
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Affiliation(s)
- L Carneiro
- Department of Physiology, University of Lausanne, Lausanne, Switzerland
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Limmer S, Weiler A, Volkenhoff A, Babatz F, Klämbt C. The Drosophila blood-brain barrier: development and function of a glial endothelium. Front Neurosci 2014; 8:365. [PMID: 25452710 PMCID: PMC4231875 DOI: 10.3389/fnins.2014.00365] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 10/23/2014] [Indexed: 01/01/2023] Open
Abstract
The efficacy of neuronal function requires a well-balanced extracellular ion homeostasis and a steady supply with nutrients and metabolites. Therefore, all organisms equipped with a complex nervous system developed a so-called blood-brain barrier, protecting it from an uncontrolled entry of solutes, metabolites or pathogens. In higher vertebrates, this diffusion barrier is established by polarized endothelial cells that form extensive tight junctions, whereas in lower vertebrates and invertebrates the blood-brain barrier is exclusively formed by glial cells. Here, we review the development and function of the glial blood-brain barrier of Drosophila melanogaster. In the Drosophila nervous system, at least seven morphologically distinct glial cell classes can be distinguished. Two of these glial classes form the blood-brain barrier. Perineurial glial cells participate in nutrient uptake and establish a first diffusion barrier. The subperineurial glial (SPG) cells form septate junctions, which block paracellular diffusion and thus seal the nervous system from the hemolymph. We summarize the molecular basis of septate junction formation and address the different transport systems expressed by the blood-brain barrier forming glial cells.
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Affiliation(s)
- Stefanie Limmer
- Institut für Neuro- und Verhaltensbiologie, Universität Münster Münster, Germany
| | - Astrid Weiler
- Institut für Neuro- und Verhaltensbiologie, Universität Münster Münster, Germany
| | - Anne Volkenhoff
- Institut für Neuro- und Verhaltensbiologie, Universität Münster Münster, Germany
| | - Felix Babatz
- Institut für Neuro- und Verhaltensbiologie, Universität Münster Münster, Germany
| | - Christian Klämbt
- Institut für Neuro- und Verhaltensbiologie, Universität Münster Münster, Germany
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14
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Lengacher S, Nehiri-Sitayeb T, Steiner N, Carneiro L, Favrod C, Preitner F, Thorens B, Stehle JC, Dix L, Pralong F, Magistretti PJ, Pellerin L. Resistance to diet-induced obesity and associated metabolic perturbations in haploinsufficient monocarboxylate transporter 1 mice. PLoS One 2013; 8:e82505. [PMID: 24367518 PMCID: PMC3867350 DOI: 10.1371/journal.pone.0082505] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Accepted: 10/24/2013] [Indexed: 01/04/2023] Open
Abstract
The monocarboxylate transporter 1 (MCT1 or SLC16A1) is a carrier of short-chain fatty acids, ketone bodies, and lactate in several tissues. Genetically modified C57BL/6J mice were produced by targeted disruption of the mct1 gene in order to understand the role of this transporter in energy homeostasis. Null mutation was embryonically lethal, but MCT1 (+/-) mice developed normally. However, when fed high fat diet (HFD), MCT1 (+/-) mice displayed resistance to development of diet-induced obesity (24.8% lower body weight after 16 weeks of HFD), as well as less insulin resistance and no hepatic steatosis as compared to littermate MCT1 (+/+) mice used as controls. Body composition analysis revealed that reduced weight gain in MCT1 (+/-) mice was due to decreased fat accumulation (50.0% less after 9 months of HFD) notably in liver and white adipose tissue. This phenotype was associated with reduced food intake under HFD (12.3% less over 10 weeks) and decreased intestinal energy absorption (9.6% higher stool energy content). Indirect calorimetry measurements showed ∼ 15% increase in O₂ consumption and CO₂ production during the resting phase, without any changes in physical activity. Determination of plasma concentrations for various metabolites and hormones did not reveal significant changes in lactate and ketone bodies levels between the two genotypes, but both insulin and leptin levels, which were elevated in MCT1 (+/+) mice when fed HFD, were reduced in MCT1 (+/-) mice under HFD. Interestingly, the enhancement in expression of several genes involved in lipid metabolism in the liver of MCT1 (+/+) mice under high fat diet was prevented in the liver of MCT1 (+/-) mice under the same diet, thus likely contributing to the observed phenotype. These findings uncover the critical role of MCT1 in the regulation of energy balance when animals are exposed to an obesogenic diet.
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Affiliation(s)
- Sylvain Lengacher
- Department of Physiology, University of Lausanne, Lausanne, Switzerland
- Laboratory of Neuroenergetic and Cellular Dynamics, Brain and Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | | | - Nadia Steiner
- Department of Physiology, University of Lausanne, Lausanne, Switzerland
| | - Lionel Carneiro
- Department of Physiology, University of Lausanne, Lausanne, Switzerland
| | - Céline Favrod
- Department of Physiology, University of Lausanne, Lausanne, Switzerland
| | - Frédéric Preitner
- Mouse Metabolic Evaluation Facility, Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Bernard Thorens
- Mouse Metabolic Evaluation Facility, Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Jean-Christophe Stehle
- Mouse Pathology Facility, Institut Universitaire de Pathologie, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Laure Dix
- Mouse Pathology Facility, Institut Universitaire de Pathologie, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - François Pralong
- Service d’endocrinologie, diabétologie et métabolisme, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Pierre J. Magistretti
- Laboratory of Neuroenergetic and Cellular Dynamics, Brain and Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Luc Pellerin
- Department of Physiology, University of Lausanne, Lausanne, Switzerland
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16
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Cook RK, Christensen SJ, Deal JA, Coburn RA, Deal ME, Gresens JM, Kaufman TC, Cook KR. The generation of chromosomal deletions to provide extensive coverage and subdivision of the Drosophila melanogaster genome. Genome Biol 2012; 13:R21. [PMID: 22445104 PMCID: PMC3439972 DOI: 10.1186/gb-2012-13-3-r21] [Citation(s) in RCA: 152] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 02/27/2012] [Accepted: 03/22/2012] [Indexed: 01/04/2023] Open
Abstract
Background Chromosomal deletions are used extensively in Drosophila melanogaster genetics research. Deletion mapping is the primary method used for fine-scale gene localization. Effective and efficient deletion mapping requires both extensive genomic coverage and a high density of molecularly defined breakpoints across the genome. Results A large-scale resource development project at the Bloomington Drosophila Stock Center has improved the choice of deletions beyond that provided by previous projects. FLP-mediated recombination between FRT-bearing transposon insertions was used to generate deletions, because it is efficient and provides single-nucleotide resolution in planning deletion screens. The 793 deletions generated pushed coverage of the euchromatic genome to 98.4%. Gaps in coverage contain haplolethal and haplosterile genes, but the sizes of these gaps were minimized by flanking these genes as closely as possible with deletions. In improving coverage, a complete inventory of haplolethal and haplosterile genes was generated and extensive information on other haploinsufficient genes was compiled. To aid mapping experiments, a subset of deletions was organized into a Deficiency Kit to provide maximal coverage efficiently. To improve the resolution of deletion mapping, screens were planned to distribute deletion breakpoints evenly across the genome. The median chromosomal interval between breakpoints now contains only nine genes and 377 intervals contain only single genes. Conclusions Drosophila melanogaster now has the most extensive genomic deletion coverage and breakpoint subdivision as well as the most comprehensive inventory of haploinsufficient genes of any multicellular organism. The improved selection of chromosomal deletion strains will be useful to nearly all Drosophila researchers.
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Affiliation(s)
- R Kimberley Cook
- Bloomington Drosophila Stock Center, Department of Biology, Indiana University, 47405, USA
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Park J, Kim Y, Choi S, Koh H, Lee SH, Kim JM, Chung J. Drosophila Porin/VDAC affects mitochondrial morphology. PLoS One 2010; 5:e13151. [PMID: 20949033 PMCID: PMC2951900 DOI: 10.1371/journal.pone.0013151] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Accepted: 09/08/2010] [Indexed: 11/18/2022] Open
Abstract
Voltage-dependent anion channel (VDAC) has been suggested to be a mediator of mitochondrial-dependent cell death induced by Ca(2+) overload, oxidative stress and Bax-Bid activation. To confirm this hypothesis in vivo, we generated and characterized Drosophila VDAC (porin) mutants and found that Porin is not required for mitochondrial apoptosis, which is consistent with the previous mouse studies. We also reported a novel physiological role of Porin. Loss of porin resulted in locomotive defects and male sterility. Intriguingly, porin mutants exhibited elongated mitochondria in indirect flight muscle, whereas Porin overexpression produced fragmented mitochondria. Through genetic analysis with the components of mitochondrial fission and fusion, we found that the elongated mitochondria phenotype in porin mutants were suppressed by increased mitochondrial fission, but enhanced by increased mitochondrial fusion. Furthermore, increased mitochondrial fission by Drp1 expression suppressed the flight defects in the porin mutants. Collectively, our study showed that loss of Drosophila Porin results in mitochondrial morphological defects and suggested that the defective mitochondrial function by Porin deficiency affects the mitochondrial remodeling process.
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Affiliation(s)
- Jeehye Park
- National Creative Research Initiatives Center for Energy Homeostasis Regulation, Seoul National University, Seoul, Korea
| | - Yongsung Kim
- National Creative Research Initiatives Center for Energy Homeostasis Regulation, Seoul National University, Seoul, Korea
- School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Sekyu Choi
- National Creative Research Initiatives Center for Energy Homeostasis Regulation, Seoul National University, Seoul, Korea
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Korea
| | - Hyongjong Koh
- Department of Pharmacology, Dong-A University College of Medicine, Busan, Korea
| | - Sang-Hee Lee
- Department of Pathology, Chungnam National University School of Medicine, Daejeon, Korea
| | - Jin-Man Kim
- Department of Pathology, Chungnam National University School of Medicine, Daejeon, Korea
| | - Jongkyeong Chung
- National Creative Research Initiatives Center for Energy Homeostasis Regulation, Seoul National University, Seoul, Korea
- School of Biological Sciences, Seoul National University, Seoul, Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Korea
- * E-mail:
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Granot Z, Swisa A, Magenheim J, Stolovich-Rain M, Fujimoto W, Manduchi E, Miki T, Lennerz JK, Stoeckert CJ, Meyuhas O, Seino S, Permutt MA, Piwnica-Worms H, Bardeesy N, Dor Y. LKB1 regulates pancreatic beta cell size, polarity, and function. Cell Metab 2009; 10:296-308. [PMID: 19808022 PMCID: PMC2790403 DOI: 10.1016/j.cmet.2009.08.010] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 06/12/2009] [Accepted: 08/19/2009] [Indexed: 02/08/2023]
Abstract
Pancreatic beta cells, organized in the islets of Langerhans, sense glucose and secrete appropriate amounts of insulin. We have studied the roles of LKB1, a conserved kinase implicated in the control of cell polarity and energy metabolism, in adult beta cells. LKB1-deficient beta cells show a dramatic increase in insulin secretion in vivo. Histologically, LKB1-deficient beta cells have striking alterations in the localization of the nucleus and cilia relative to blood vessels, suggesting a shift from hepatocyte-like to columnar polarity. Additionally, LKB1 deficiency causes a 65% increase in beta cell volume. We show that distinct targets of LKB1 mediate these effects. LKB1 controls beta cell size, but not polarity, via the mTOR pathway. Conversely, the precise position of the beta cell nucleus, but not cell size, is controlled by the LKB1 target Par1b. Insulin secretion and content are restricted by LKB1, at least in part, via AMPK. These results expose a molecular mechanism, orchestrated by LKB1, for the coordinated maintenance of beta cell size, form, and function.
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Affiliation(s)
- Zvi Granot
- Department of Developmental Biology and Cancer Research and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
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Jansen M, Ten Klooster JP, Offerhaus GJ, Clevers H. LKB1 and AMPK family signaling: the intimate link between cell polarity and energy metabolism. Physiol Rev 2009; 89:777-98. [PMID: 19584313 DOI: 10.1152/physrev.00026.2008] [Citation(s) in RCA: 165] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Research on the LKB1 tumor suppressor protein mutated in cancer-prone Peutz-Jeghers patients has continued at a feverish pace following exciting developments linking energy metabolism and cancer development. This review summarizes the current state of research on the LKB1 tumor suppressor. The weight of the evidence currently indicates an evolutionary conserved role for the protein in the regulation of various aspects of cellular polarity and energy metabolism. We focus on studies examining the concept that both cellular polarity and energy metabolism are regulated through the conserved LKB1-AMPK signal transduction pathway. Recent studies from a variety of model organisms have given new insight into the mechanism of polyp development and cancer formation in Peutz-Jeghers patients and the role of LKB1 mutation in sporadic tumorigenesis. Conditional LKB1 mouse models have outlined a tissue-dependent context for pathway activation and suggest that LKB1 may affect different AMPK isoforms independently. Elucidation of the molecular mechanism responsible for Peutz-Jeghers syndrome will undoubtedly reveal important insight into cancer development in the larger population.
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Affiliation(s)
- Marnix Jansen
- Hubrecht Institute, Developmental Biology and Stem Cell Research, 3584 CT Utrecht, The Netherlands
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Filippi BM, Alessi DR. Novel role for the LKB1 pathway in controlling monocarboxylate fuel transporters. ACTA ACUST UNITED AC 2008; 183:7-9. [PMID: 18838550 PMCID: PMC2557034 DOI: 10.1083/jcb.200809056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A question preoccupying many researchers is how signal transduction pathways control metabolic processes and energy production. A study by Jang et al. (Jang, C., G. Lee, and J. Chung. 2008. J. Cell Biol. 183:11–17) provides evidence that in Drosophila melanogaster a signaling network controlled by the LKB1 tumor suppressor regulates trafficking of an Sln/dMCT1 monocarboxylate transporter to the plasma membrane. This enables cells to import additional energy sources such as lactate and butyrate, enhancing the repertoire of fuels they can use to power vital activities.
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Affiliation(s)
- Beatrice Maria Filippi
- Medical Research Council Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK.
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