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Liebscher G, Vujic N, Schreiber R, Heine M, Krebiehl C, Duta-Mare M, Lamberti G, de Smet CH, Hess MW, Eichmann TO, Hölzl S, Scheja L, Heeren J, Kratky D, Huber LA. The lysosomal LAMTOR / Ragulator complex is essential for nutrient homeostasis in brown adipose tissue. Mol Metab 2023; 71:101705. [PMID: 36907508 PMCID: PMC10074977 DOI: 10.1016/j.molmet.2023.101705] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 02/28/2023] [Accepted: 03/06/2023] [Indexed: 03/13/2023] Open
Abstract
OBJECTIVE In brown adipose tissue (iBAT), the balance between lipid/glucose uptake and lipolysis is tightly regulated by insulin signaling. Downstream of the insulin receptor, PDK1 and mTORC2 phosphorylate AKT, which activates glucose uptake and lysosomal mTORC1 signaling. The latter requires the late endosomal/lysosomal adaptor and MAPK and mTOR activator (LAMTOR/Ragulator) complex, which serves to translate the nutrient status of the cell to the respective kinase. However, the role of LAMTOR in metabolically active iBAT has been elusive. METHODS Using an AdipoqCRE-transgenic mouse line, we deleted LAMTOR2 (and thereby the entire LAMTOR complex) in adipose tissue (LT2 AKO). To examine the metabolic consequences, we performed metabolic and biochemical studies in iBAT isolated from mice housed at different temperatures (30 °C, room temperature and 5 °C), after insulin treatment, or in fasted and refed condition. For mechanistic studies, mouse embryonic fibroblasts (MEFs) lacking LAMTOR 2 were analyzed. RESULTS Deletion of the LAMTOR complex in mouse adipocytes resulted in insulin-independent AKT hyperphosphorylation in iBAT, causing increased glucose and fatty acid uptake, which led to massively enlarged lipid droplets. As LAMTOR2 was essential for the upregulation of de novo lipogenesis, LAMTOR2 deficiency triggered exogenous glucose storage as glycogen in iBAT. These effects are cell autonomous, since AKT hyperphosphorylation was abrogated by PI3K inhibition or by deletion of the mTORC2 component Rictor in LAMTOR2-deficient MEFs. CONCLUSIONS We identified a homeostatic circuit for the maintenance of iBAT metabolism that links the LAMTOR-mTORC1 pathway to PI3K-mTORC2-AKT signaling downstream of the insulin receptor.
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Affiliation(s)
- Gudrun Liebscher
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Nemanja Vujic
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstr. 6, 8010 Graz, Austria
| | - Renate Schreiber
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Markus Heine
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Caroline Krebiehl
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Madalina Duta-Mare
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstr. 6, 8010 Graz, Austria
| | - Giorgia Lamberti
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Cedric H de Smet
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Michael W Hess
- Institute of Histology and Embryology, Medical University of Innsbruck, Müllerstrasse 59, 6020 Innsbruck, Austria
| | - Thomas O Eichmann
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Sarah Hölzl
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Ludger Scheja
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Joerg Heeren
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Dagmar Kratky
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstr. 6, 8010 Graz, Austria; BioTechMed-Graz, Mozartgasse 12, 8010 Graz, Austria
| | - Lukas A Huber
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria.
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Sachdev V, Duta-Mare M, Korbelius M, Vujić N, Leopold C, Freark de Boer J, Rainer S, Fickert P, Kolb D, Kuipers F, Radovic B, Gorkiewicz G, Kratky D. Impaired Bile Acid Metabolism and Gut Dysbiosis in Mice Lacking Lysosomal Acid Lipase. Cells 2021; 10:2619. [PMID: 34685599 PMCID: PMC8533808 DOI: 10.3390/cells10102619] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/26/2021] [Accepted: 09/27/2021] [Indexed: 12/12/2022] Open
Abstract
Lysosomal acid lipase (LAL) is the sole enzyme known to be responsible for the hydrolysis of cholesteryl esters and triglycerides at an acidic pH in lysosomes, resulting in the release of unesterified cholesterol and free fatty acids. However, the role of LAL in diet-induced adaptations is largely unexplored. In this study, we demonstrate that feeding a Western-type diet to Lal-deficient (LAL-KO) mice triggers metabolic reprogramming that modulates gut-liver cholesterol homeostasis. Induction of ileal fibroblast growth factor 15 (three-fold), absence of hepatic cholesterol 7α-hydroxylase expression, and activation of the ERK phosphorylation cascade results in altered bile acid composition, substantial changes in the gut microbiome, reduced nutrient absorption by 40%, and two-fold increased fecal lipid excretion in LAL-KO mice. These metabolic adaptations lead to impaired bile acid synthesis, lipoprotein uptake, and cholesterol absorption and ultimately to the resistance of LAL-KO mice to diet-induced obesity. Our results indicate that LAL-derived lipolytic products might be important metabolic effectors in the maintenance of whole-body lipid homeostasis.
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Affiliation(s)
- Vinay Sachdev
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (V.S.); (M.D.-M.); (M.K.); (N.V.); (C.L.); (S.R.); (B.R.)
| | - Madalina Duta-Mare
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (V.S.); (M.D.-M.); (M.K.); (N.V.); (C.L.); (S.R.); (B.R.)
| | - Melanie Korbelius
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (V.S.); (M.D.-M.); (M.K.); (N.V.); (C.L.); (S.R.); (B.R.)
| | - Nemanja Vujić
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (V.S.); (M.D.-M.); (M.K.); (N.V.); (C.L.); (S.R.); (B.R.)
| | - Christina Leopold
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (V.S.); (M.D.-M.); (M.K.); (N.V.); (C.L.); (S.R.); (B.R.)
| | - Jan Freark de Boer
- Department of Pediatrics, University Medical Center Groningen, 9713 Groningen, The Netherlands; (J.F.d.B.); (F.K.)
- Department of Laboratory Medicine, University Medical Center Groningen, 9713 Groningen, The Netherlands
| | - Silvia Rainer
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (V.S.); (M.D.-M.); (M.K.); (N.V.); (C.L.); (S.R.); (B.R.)
| | - Peter Fickert
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, 8010 Graz, Austria;
| | - Dagmar Kolb
- Cell Biology, Histology and Embryology, Gottfried Schatz Research Center, 8010 Graz, Austria;
- Center for Medical Research Medical University of Graz, 8010 Graz, Austria
| | - Folkert Kuipers
- Department of Pediatrics, University Medical Center Groningen, 9713 Groningen, The Netherlands; (J.F.d.B.); (F.K.)
- Department of Laboratory Medicine, University Medical Center Groningen, 9713 Groningen, The Netherlands
| | - Branislav Radovic
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (V.S.); (M.D.-M.); (M.K.); (N.V.); (C.L.); (S.R.); (B.R.)
| | - Gregor Gorkiewicz
- Diagnostic and Research Institute of Pathology, Medical University of Graz, 8010 Graz, Austria;
| | - Dagmar Kratky
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (V.S.); (M.D.-M.); (M.K.); (N.V.); (C.L.); (S.R.); (B.R.)
- BioTechMed-Graz, 8010 Graz, Austria
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3
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Helderman RC, Whitney DG, Duta-Mare M, Akhmetshina A, Vujic N, Jayapalan S, Nyman JS, Misra BB, Rosen CJ, Czech MP, Kratky D, Rendina-Ruedy E. Loss of function of lysosomal acid lipase (LAL) profoundly impacts osteoblastogenesis and increases fracture risk in humans. Bone 2021; 148:115946. [PMID: 33838322 PMCID: PMC8108562 DOI: 10.1016/j.bone.2021.115946] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/26/2021] [Accepted: 04/01/2021] [Indexed: 11/28/2022]
Abstract
Lysosomal acid lipase (LAL) is essential for cholesteryl ester (CE) and triacylglycerol (TAG) hydrolysis in the lysosome. Clinically, an autosomal recessive LIPA mutation causes LAL deficiency (LALD), previously described as Wolman Disease or Cholesteryl Ester Storage Disease (CESD). LAL-D is associated with ectopic lipid accumulation in the liver, small intestine, spleen, adrenal glands, and blood. Considering the importance of unesterified cholesterol and fatty acids in bone metabolism, we hypothesized that LAL is essential for bone formation, and ultimately, skeletal health. To investigate the role of LAL in skeletal homeostasis, we used LAL-deficient (-/-) mice, in vitro osteoblast cultures, and novel clinical data from LAL-D patients. Both male and female LAL-/- mice demonstarted lower trabecular and cortical bone parameters , which translated to reduced biomechanical properties. Further histological analyses revealed that LAL-/- mice had fewer osteoblasts, with no change in osteoclast or marrow adipocyte numbers. In studying the cell-autonomous role of LAL, we observed impaired differentiation of LAL-/- calvarial osteoblasts and in bone marrow stromal cells treated with the LAL inhibitor lalistat. Consistent with LAL's role in other tissues, lalistat resulted in profound lipid puncta accumulation and an altered intracellular lipid profile. Finally, we analyzed a large de-identified national insurance database (i.e. 2016/2017 Optum Clinformatics®) which revealed that adults (≥18 years) with CESD (n = 3076) had a higher odds ratio (OR = 1.21; 95% CI = 1.03-1.41) of all-cause fracture at any location compared to adults without CESD (n = 13.7 M) after adjusting for demographic variables and osteoporosis. These data demonstrate that alterations in LAL have significant clinical implications related to fracture risk and that LAL's modulation of lipid metabolism is a critical for osteoblast function.
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Affiliation(s)
- Ron C Helderman
- Maine Medical Center Research Institute, 81 Research Drive, Scarborough, ME 04074, USA; Center for Bone Biology, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Daniel G Whitney
- Department of Physical Medicine and Rehabilitation, University of Michigan, Ann Arbor, MI 48108, USA; Institute for Healthcare Policy and Innovation, University of Michigan, Ann Arbor, MI, 48107, USA
| | - Madalina Duta-Mare
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/6, 8010 Graz, Austria
| | - Alena Akhmetshina
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/6, 8010 Graz, Austria
| | - Nemanja Vujic
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/6, 8010 Graz, Austria
| | - Shobana Jayapalan
- Center for Bone Biology, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Jeffry S Nyman
- Center for Bone Biology, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN 37212, USA
| | - Biswapriya B Misra
- Center for Precision Medicine, Department of Internal Medicine, Section of Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27104, USA
| | - Clifford J Rosen
- Maine Medical Center Research Institute, 81 Research Drive, Scarborough, ME 04074, USA
| | - Michael P Czech
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Dagmar Kratky
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6/6, 8010 Graz, Austria; BioTechMed-Graz, 8010 Graz, Austria
| | - Elizabeth Rendina-Ruedy
- Maine Medical Center Research Institute, 81 Research Drive, Scarborough, ME 04074, USA; Center for Bone Biology, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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4
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Klec C, Madreiter-Sokolowski CT, Ziomek G, Stryeck S, Sachdev V, Duta-Mare M, Gottschalk B, Depaoli MR, Rost R, Hay J, Waldeck-Weiermair M, Kratky D, Madl T, Malli R, Graier WF. Presenilin-1 Established ER-Ca 2+ Leak: a Follow Up on Its Importance for the Initial Insulin Secretion in Pancreatic Islets and β-Cells upon Elevated Glucose. Cell Physiol Biochem 2019; 53:573-586. [PMID: 31529929 DOI: 10.33594/000000158] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2019] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND/AIMS In our recent work, the importance of GSK3β-mediated phosphorylation of presenilin-1 as crucial process to establish a Ca2+ leak in the endoplasmic reticulum and, subsequently, the pre-activation of resting mitochondrial activity in β-cells was demonstrated. The present work is a follow-up and reveals the importance of GSK3β-phosphorylated presenilin-1 for responsiveness of pancreatic islets and β-cells to elevated glucose in terms of cytosolic Ca2+ spiking and insulin secretion. METHODS Freshly isolated pancreatic islets and the two pancreatic β-cell lines INS-1 and MIN-6 were used. Cytosolic Ca2+ was fluorometrically monitored using Fura-2/AM and cellular insulin content and secretion were measured by ELISA. RESULTS Our data strengthened our previous findings of the existence of a presenilin-1-mediated ER-Ca2+ leak in β-cells, since a reduction of presenilin-1 expression strongly counteracted the ER Ca2+ leak. Furthermore, our data revealed that cytosolic Ca2+ spiking upon administration of high D-glucose was delayed in onset time and strongly reduced in amplitude and frequency upon siRNA-mediated knock-down of presenilin-1 or the inhibition of GSK3β in the pancreatic β-cells. Moreover, glucose-triggered initial insulin secretion disappeared by depletion from presenilin-1 and inhibition of GSK3β in the pancreatic β-cells and isolated pancreatic islets, respectively. CONCLUSION These data complement our previous work and demonstrate that the sensitivity of pancreatic islets and β-cells to glucose illustrated as glucose-triggered cytosolic Ca2+ spiking and initial but not long-lasting insulin secretion crucially depends on a strong ER Ca2+ leak that is due to the phosphorylation of presenilin-1 by GSK3β, a phenomenon that might be involved in the development of type 2 diabetes.
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Affiliation(s)
- Christiane Klec
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria.,Research Unit for Non-Coding RNAs and Genome Editing in Cancer, Division of Oncology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Corina T Madreiter-Sokolowski
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria
| | - Gabriela Ziomek
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria
| | - Sarah Stryeck
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria
| | - Vinay Sachdev
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria.,Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Madalina Duta-Mare
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria
| | - Benjamin Gottschalk
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria
| | - Maria R Depaoli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria
| | - Rene Rost
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria
| | - Jesse Hay
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria.,University of Montana, Division of Biological Sciences, Center for Structural & Functional Neuroscience, Missoula, MT, USA
| | - Markus Waldeck-Weiermair
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria
| | - Dagmar Kratky
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Tobias Madl
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Roland Malli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Wolfgang F Graier
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria.,BioTechMed, Graz, Austria,
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5
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Ivanov S, Viaud M, Vujic N, Duta-Mare M, Dugail I, Hainault I, Stehlik C, Marchetti S, Boyer L, Guinamard R, Foufelle F, Bochem A, Hovingh K, Thorp E, Gautier E, Kratky D, Yvan-Charvet L. Lysosomal Cholesterol Hydrolysis Couples Efferocytosis To Anti-Inflammatory Oxysterol Production. Atherosclerosis 2019. [DOI: 10.1016/j.atherosclerosis.2019.06.223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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6
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Klec C, Madreiter-Sokolowski CT, Stryeck S, Sachdev V, Duta-Mare M, Gottschalk B, Depaoli MR, Rost R, Hay J, Waldeck-Weiermair M, Kratky D, Madl T, Malli R, Graier WF. Glycogen Synthase Kinase 3 Beta Controls Presenilin-1-Mediated Endoplasmic Reticulum Ca²⁺ Leak Directed to Mitochondria in Pancreatic Islets and β-Cells. Cell Physiol Biochem 2019; 52:57-75. [PMID: 30790505 PMCID: PMC6459368 DOI: 10.33594/000000005] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 01/15/2019] [Indexed: 01/09/2023] Open
Abstract
Background/Aims In pancreatic β-cells, the intracellular Ca2+ homeostasis is an essential regulator of the cells’ major functions. The endoplasmic reticulum (ER) as interactive intracellular Ca2+ store balances cellular Ca2+. In this study basal ER Ca2+ homeostasis was evaluated in order to reveal potential β-cell-specificity of ER Ca2+ handling and its consequences for mitochondrial Ca2+, ATP and respiration. Methods The two pancreatic cell lines INS-1 and MIN-6, freshly isolated pancreatic islets, and the two non-pancreatic cell lines HeLA and EA.hy926 were used. Cytosolic, ER and mitochondrial Ca2+ and ATP measurements were performed using single cell fluorescence microscopy and respective (genetically-encoded) sensors/dyes. Mitochondrial respiration was monitored by respirometry. GSK3β activity was measured with ELISA. Results An atypical ER Ca2+ leak was observed exclusively in pancreatic islets and β-cells. This continuous ER Ca2+ efflux is directed to mitochondria and increases basal respiration and organellar ATP levels, is established by GSK3β-mediated phosphorylation of presenilin-1, and is prevented by either knockdown of presenilin-1 or an inhibition/knockdown of GSK3β. Expression of a presenlin-1 mutant that mimics GSK3β-mediated phosphorylation established a β-cell-like ER Ca2+ leak in HeLa and EA.hy926 cells. The ER Ca2+ loss in β-cells was compensated at steady state by Ca2+ entry that is linked to the activity of TRPC3. Conclusion Pancreatic β-cells establish a cell-specific ER Ca2+ leak that is under the control of GSK3β and directed to mitochondria, thus, reflecting a cell-specific intracellular Ca2+ handling for basal mitochondrial activity.
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Affiliation(s)
- Christiane Klec
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria
| | - Corina T Madreiter-Sokolowski
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria
| | - Sarah Stryeck
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria
| | - Vinay Sachdev
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria.,Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Madalina Duta-Mare
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria
| | - Benjamin Gottschalk
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria
| | - Maria R Depaoli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria
| | - Rene Rost
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria
| | - Jesse Hay
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria.,University of Montana, Division of Biological Sciences, Center for Structural & Functional Neuroscience, Missoula, MT, USA
| | - Markus Waldeck-Weiermair
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria
| | - Dagmar Kratky
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Tobias Madl
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Roland Malli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Wolfgang F Graier
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria.,BioTechMed, Graz, Austria.,Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cellular Signaling, Metabolism & Aging, Medical University of Graz, Graz, Austria,
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7
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Leopold C, Duta-Mare M, Sachdev V, Goeritzer M, Maresch LK, Kolb D, Reicher H, Wagner B, Stojakovic T, Ruelicke T, Haemmerle G, Hoefler G, Sattler W, Kratky D. Hepatocyte-specific lysosomal acid lipase deficiency protects mice from diet-induced obesity but promotes hepatic inflammation. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:500-511. [PMID: 30639734 PMCID: PMC6372077 DOI: 10.1016/j.bbalip.2019.01.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/20/2018] [Accepted: 01/06/2019] [Indexed: 12/21/2022]
Abstract
Lysosomal acid lipase (LAL) hydrolyzes cholesteryl esters (CE) and triglycerides (TG) to generate fatty acids (FA) and cholesterol. LAL deficiency (LAL-D) in both humans and mice leads to hepatomegaly, hypercholesterolemia, and shortened life span. Despite its essential role in lysosomal neutral lipid catabolism, the cell type-specific contribution of LAL to disease progression is still elusive. To investigate the role of LAL in the liver in more detail and to exclude the contribution of LAL in macrophages, we generated hepatocyte-specific LAL-deficient mice (Liv-Lipa−/−) and fed them either chow or high fat/high cholesterol diets (HF/HCD). Comparable to systemic LAL-D, Liv-Lipa−/− mice were resistant to diet-induced obesity independent of food intake, movement, and energy expenditure. Reduced body weight gain was mainly due to reduced white adipose tissue depots. Furthermore, Liv-Lipa−/− mice exhibited improved glucose clearance during glucose and insulin tolerance tests compared to control mice. Analysis of hepatic lipid content revealed a massive reduction of TG, whereas CE concentrations were markedly increased, leading to CE crystal formation in the livers of Liv-Lipa−/− mice. Elevated plasma transaminase activities, increased pro-inflammatory cytokines and chemokines as well as hepatic macrophage infiltration indicated liver inflammation. Our data provide evidence that hepatocyte-specific LAL deficiency is sufficient to alter whole-body lipid and energy homeostasis in mice. We conclude that hepatic LAL plays a pivotal role by preventing liver damage and maintaining lipid and energy homeostasis, especially during high lipid availability.
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Affiliation(s)
- Christina Leopold
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Madalina Duta-Mare
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Vinay Sachdev
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | | | | | - Dagmar Kolb
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria; Center for Medical Research, Medical University of Graz, Graz, Austria
| | - Helga Reicher
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Bettina Wagner
- Institute of Laboratory Animal Science, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Tatjana Stojakovic
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
| | - Thomas Ruelicke
- Institute of Laboratory Animal Science, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Guenter Haemmerle
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Gerald Hoefler
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Wolfgang Sattler
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Dagmar Kratky
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria.
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8
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Huber K, Hofer DC, Trefely S, Pelzmann HJ, Madreiter-Sokolowski C, Duta-Mare M, Schlager S, Trausinger G, Stryeck S, Graier WF, Kolb D, Magnes C, Snyder NW, Prokesch A, Kratky D, Madl T, Wellen KE, Bogner-Strauss JG. N-acetylaspartate pathway is nutrient responsive and coordinates lipid and energy metabolism in brown adipocytes. Biochim Biophys Acta Mol Cell Res 2018; 1866:337-348. [PMID: 30595160 PMCID: PMC6390944 DOI: 10.1016/j.bbamcr.2018.08.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 08/27/2018] [Indexed: 12/22/2022]
Abstract
The discovery of significant amounts of metabolically active brown adipose tissue (BAT) in adult humans renders it a promising target for anti-obesity therapies by inducing weight loss through increased energy expenditure. The components of the N-acetylaspartate (NAA) pathway are highly abundant in BAT. Aspartate N-acetyltransferase (Asp-NAT, encoded by Nat8l) synthesizes NAA from acetyl-CoA and aspartate and increases energy expenditure in brown adipocytes. However, the exact mechanism how the NAA pathway contributes to accelerated mobilization and oxidation of lipids and the physiological regulation of the NAA pathway remained elusive. Here, we demonstrate that the expression of NAA pathway genes corresponds to nutrient availability and specifically responds to changes in exogenous glucose. NAA is preferentially produced from glucose-derived acetyl-CoA and aspartate and its concentration increases during adipogenesis. Overexpression of Nat8l drains glucose-derived acetyl-CoA into the NAA pool at the expense of cellular lipids and certain amino acids. Mechanistically, we elucidated that a combined activation of neutral and lysosomal (acid) lipolysis is responsible for the increased lipid degradation. Specifically, translocation of the transcription factor EB to the nucleus activates the biosynthesis of autophagosomes and lysosomes. Lipid degradation within lysosomes accompanied by adipose triglyceride lipase-mediated lipolysis delivers fatty acids for the support of elevated mitochondrial respiration. Together, our data suggest a crucial role of the NAA pathway in energy metabolism and metabolic adaptation in BAT.
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Affiliation(s)
- Katharina Huber
- Institute of Biochemistry, Graz University of Technology, Graz, Austria; Department of Cancer Biology, University of Pennsylvania, Philadelphia, USA; Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, USA
| | - Dina C Hofer
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
| | - Sophie Trefely
- Department of Cancer Biology, University of Pennsylvania, Philadelphia, USA; Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, USA; AJ Drexel Autism Institute, Drexel University, Philadelphia, USA
| | - Helmut J Pelzmann
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
| | - Corina Madreiter-Sokolowski
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Cell Biology, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Madalina Duta-Mare
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Cell Biology, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Stefanie Schlager
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Cell Biology, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Gert Trausinger
- HEALTH Institute for Biomedicine and Health Sciences, Joanneum Research, Graz, Austria
| | - Sarah Stryeck
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Cell Biology, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Wolfgang F Graier
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Cell Biology, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Dagmar Kolb
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Cell Biology, Histology and Embryology, Medical University of Graz, Graz, Austria
| | - Christoph Magnes
- HEALTH Institute for Biomedicine and Health Sciences, Joanneum Research, Graz, Austria
| | | | - Andreas Prokesch
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Cell Biology, Histology and Embryology, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Dagmar Kratky
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Cell Biology, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Tobias Madl
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Cell Biology, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Kathryn E Wellen
- Department of Cancer Biology, University of Pennsylvania, Philadelphia, USA; Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, USA
| | - Juliane G Bogner-Strauss
- Institute of Biochemistry, Graz University of Technology, Graz, Austria; BioTechMed-Graz, Graz, Austria.
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9
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Vujic N, Korbelius M, Leopold C, Duta-Mare M, Rainer S, Schlager S, Goeritzer M, Kolb D, Eichmann TO, Diwoky C, Zimmer A, Zimmermann R, Lass A, Radovic B, Kratky D. Monoglyceride lipase deficiency affects hepatic cholesterol metabolism and lipid-dependent gut transit in ApoE-/- mice. Oncotarget 2018; 8:33122-33136. [PMID: 28380440 PMCID: PMC5464855 DOI: 10.18632/oncotarget.16529] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 03/14/2017] [Indexed: 11/25/2022] Open
Abstract
Monoglyceride lipase (MGL) hydrolyzes monoglycerides (MGs) to glycerol and fatty acids. Among various MG species MGL also degrades 2-arachidonoylglycerol (2-AG), the most abundant endocannabinoid and potent activator of cannabinoid receptors (CBR) 1 and 2. MGL-knockout (-/-) mice exhibit pronounced 2-AG accumulation, but lack central cannabimimetic effects due to CB1R desensitization. We have previously shown that MGL affects plaque stability in apolipoprotein E (ApoE)-/- mice, an established animal model for dyslipidemia and atherosclerosis. In the current study, we investigated functional consequences of MGL deficiency on lipid and energy metabolism in ApoE/MGL double knockout (DKO) mice. MGL deficiency affected hepatic cholesterol metabolism by causing increased cholesterol elimination via the biliary pathway. Moreover, DKO mice exhibit lipid-triggered delay in gastric emptying without major effects on overall triglyceride and cholesterol absorption. The observed phenotype of DKO mice is likely not a consequence of potentiated CB1R signaling but rather dependent on the activation of alternative signaling pathways. We conclude that MGL deficiency causes complex metabolic changes including cholesterol metabolism and regulation of gut transit independent of the endocannabinoid system.
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Affiliation(s)
- Nemanja Vujic
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Melanie Korbelius
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Christina Leopold
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Madalina Duta-Mare
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Silvia Rainer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Stefanie Schlager
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Madeleine Goeritzer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Dagmar Kolb
- Center for Medical Research, Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Austria
| | - Thomas O Eichmann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Clemens Diwoky
- Institute of Biomedical Engineering, Graz University of Technology, Graz, Austria.,Current address: Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Andreas Zimmer
- Institute of Pharmaceutical Sciences, University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Achim Lass
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Branislav Radovic
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
| | - Dagmar Kratky
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria.,BioTechMed, Graz, Austria
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10
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Viaud M, Ivanov S, Vujic N, Duta-Mare M, Aira LE, Barouillet T, Garcia E, Orange F, Dugail I, Hainault I, Stehlik C, Marchetti S, Boyer L, Guinamard R, Foufelle F, Bochem A, Hovingh KG, Thorp EB, Gautier EL, Kratky D, Dasilva-Jardine P, Yvan-Charvet L. Lysosomal Cholesterol Hydrolysis Couples Efferocytosis to Anti-Inflammatory Oxysterol Production. Circ Res 2018. [PMID: 29523554 DOI: 10.1161/circresaha.117.312333] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Macrophages face a substantial amount of cholesterol after the ingestion of apoptotic cells, and the LIPA (lysosomal acid lipase) has a major role in hydrolyzing cholesteryl esters in the endocytic compartment. OBJECTIVE Here, we directly investigated the role of LIPA-mediated clearance of apoptotic cells both in vitro and in vivo. METHODS AND RESULTS We show that LIPA inhibition causes a defective efferocytic response because of impaired generation of 25-hydroxycholesterol and 27-hydroxycholesterol. Reduced synthesis of 25-hydroxycholesterol after LIPA inhibition contributed to defective mitochondria-associated membrane leading to mitochondrial oxidative stress-induced NLRP3 (NOD-like receptor family, pyrin domain containing) inflammasome activation and caspase-1-dependent Rac1 (Ras-related C3 botulinum toxin substrate 1) degradation. A secondary event consisting of failure to appropriately activate liver X receptor-mediated pathways led to mitigation of cholesterol efflux and apoptotic cell clearance. In mice, LIPA inhibition caused defective clearance of apoptotic lymphocytes and stressed erythrocytes by hepatic and splenic macrophages, culminating in splenomegaly and splenic iron accumulation under hypercholesterolemia. CONCLUSIONS Our findings position lysosomal cholesterol hydrolysis as a critical process that prevents metabolic inflammation by enabling efficient macrophage apoptotic cell clearance.
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Affiliation(s)
- Manon Viaud
- From the Institut National de la Santé et de la Recherche Médicale (Inserm) U1065, Université Côte d'Azur, Centre Méditerranéen de Médecine Moléculaire (C3M), Atip-Avenir, Fédération Hospitalo-Universitaire (FHU) Oncoage, Nice, France (M.V., S.I., L.-E.A., E.G., S.M., L.B., R.G., L.Y.-C.)
| | - Stoyan Ivanov
- From the Institut National de la Santé et de la Recherche Médicale (Inserm) U1065, Université Côte d'Azur, Centre Méditerranéen de Médecine Moléculaire (C3M), Atip-Avenir, Fédération Hospitalo-Universitaire (FHU) Oncoage, Nice, France (M.V., S.I., L.-E.A., E.G., S.M., L.B., R.G., L.Y.-C.)
| | - Nemanja Vujic
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria (N.V., M.D.-M., D.K.)
| | - Madalina Duta-Mare
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria (N.V., M.D.-M., D.K.)
| | - Lazaro-Emilio Aira
- From the Institut National de la Santé et de la Recherche Médicale (Inserm) U1065, Université Côte d'Azur, Centre Méditerranéen de Médecine Moléculaire (C3M), Atip-Avenir, Fédération Hospitalo-Universitaire (FHU) Oncoage, Nice, France (M.V., S.I., L.-E.A., E.G., S.M., L.B., R.G., L.Y.-C.)
| | | | - Elsa Garcia
- From the Institut National de la Santé et de la Recherche Médicale (Inserm) U1065, Université Côte d'Azur, Centre Méditerranéen de Médecine Moléculaire (C3M), Atip-Avenir, Fédération Hospitalo-Universitaire (FHU) Oncoage, Nice, France (M.V., S.I., L.-E.A., E.G., S.M., L.B., R.G., L.Y.-C.)
| | - Francois Orange
- UFR Sciences, Faculté des Sciences de l'Université de Nice-Sophia Antipolis, France (F.O.)
| | - Isabelle Dugail
- Institut National de la Santé et de la Recherche Médicale (INSERM) UMR_S 1166, Pierre & Marie Curie University, ICAN Institute of Cardiometabolism & Nutrition, Hôpital de la Pitié, Boulevard de l'Hôpital, Paris, France (I.D., E.L.G.)
| | - Isabelle Hainault
- Institut National de la Santé et de la Recherche Médicale (Inserm) UMRS 1138, Centre de Recherche des Cordeliers, Paris, France (I.H., F.F.)
| | - Christian Stehlik
- Department of Pathology, Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL (C.S., E.B.T.)
| | - Sandrine Marchetti
- From the Institut National de la Santé et de la Recherche Médicale (Inserm) U1065, Université Côte d'Azur, Centre Méditerranéen de Médecine Moléculaire (C3M), Atip-Avenir, Fédération Hospitalo-Universitaire (FHU) Oncoage, Nice, France (M.V., S.I., L.-E.A., E.G., S.M., L.B., R.G., L.Y.-C.)
| | - Laurent Boyer
- From the Institut National de la Santé et de la Recherche Médicale (Inserm) U1065, Université Côte d'Azur, Centre Méditerranéen de Médecine Moléculaire (C3M), Atip-Avenir, Fédération Hospitalo-Universitaire (FHU) Oncoage, Nice, France (M.V., S.I., L.-E.A., E.G., S.M., L.B., R.G., L.Y.-C.)
| | - Rodolphe Guinamard
- From the Institut National de la Santé et de la Recherche Médicale (Inserm) U1065, Université Côte d'Azur, Centre Méditerranéen de Médecine Moléculaire (C3M), Atip-Avenir, Fédération Hospitalo-Universitaire (FHU) Oncoage, Nice, France (M.V., S.I., L.-E.A., E.G., S.M., L.B., R.G., L.Y.-C.)
| | - Fabienne Foufelle
- Institut National de la Santé et de la Recherche Médicale (Inserm) UMRS 1138, Centre de Recherche des Cordeliers, Paris, France (I.H., F.F.)
| | | | | | - Edward B Thorp
- Department of Pathology, Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL (C.S., E.B.T.)
| | - Emmanuel L Gautier
- Institut National de la Santé et de la Recherche Médicale (INSERM) UMR_S 1166, Pierre & Marie Curie University, ICAN Institute of Cardiometabolism & Nutrition, Hôpital de la Pitié, Boulevard de l'Hôpital, Paris, France (I.D., E.L.G.)
| | - Dagmar Kratky
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria (N.V., M.D.-M., D.K.)
| | - Paul Dasilva-Jardine
- Academic Medical Center, Amsterdam, The Netherlands; and Staten Biotechnology, Nijmegen, The Netherlands (P.D.-J.)
| | - Laurent Yvan-Charvet
- From the Institut National de la Santé et de la Recherche Médicale (Inserm) U1065, Université Côte d'Azur, Centre Méditerranéen de Médecine Moléculaire (C3M), Atip-Avenir, Fédération Hospitalo-Universitaire (FHU) Oncoage, Nice, France (M.V., S.I., L.-E.A., E.G., S.M., L.B., R.G., L.Y.-C.)
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11
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Duta-Mare M, Sachdev V, Leopold C, Kolb D, Vujic N, Korbelius M, Hofer DC, Xia W, Huber K, Auer M, Gottschalk B, Magnes C, Graier WF, Prokesch A, Radovic B, Bogner-Strauss JG, Kratky D. Lysosomal acid lipase regulates fatty acid channeling in brown adipose tissue to maintain thermogenesis. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:467-478. [PMID: 29374543 DOI: 10.1016/j.bbalip.2018.01.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 01/02/2018] [Accepted: 01/22/2018] [Indexed: 02/07/2023]
Abstract
Lysosomal acid lipase (LAL) is the only known enzyme, which hydrolyzes cholesteryl esters and triacylglycerols in lysosomes of multiple cells and tissues. Here, we explored the role of LAL in brown adipose tissue (BAT). LAL-deficient (Lal-/-) mice exhibit markedly reduced UCP1 expression in BAT, modified BAT morphology with accumulation of lysosomes, and mitochondrial dysfunction, consequently leading to regular hypothermic events in mice kept at room temperature. Cold exposure resulted in reduced lipid uptake into BAT, thereby aggravating dyslipidemia and causing life threatening hypothermia in Lal-/- mice. Linking LAL as a potential regulator of lipoprotein lipase activity, we found Angptl4 mRNA expression upregulated in BAT. Our data demonstrate that LAL is critical for shuttling fatty acids derived from circulating lipoproteins to BAT during cold exposure. We conclude that inhibited lysosomal lipid hydrolysis in BAT leads to impaired thermogenesis in Lal-/- mice.
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Affiliation(s)
- Madalina Duta-Mare
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Vinay Sachdev
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Christina Leopold
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Dagmar Kolb
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria; Center for Medical Research, Medical University of Graz, Graz, Austria
| | - Nemanja Vujic
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Melanie Korbelius
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Dina C Hofer
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
| | - Wenmin Xia
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
| | - Katharina Huber
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
| | - Martina Auer
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | | | - Christoph Magnes
- Health, Bioanalytik und Metabolomics, Joanneum Research, Graz, Austria
| | - Wolfgang F Graier
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Andreas Prokesch
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Branislav Radovic
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Juliane G Bogner-Strauss
- Institute of Biochemistry, Graz University of Technology, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Dagmar Kratky
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria.
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12
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Schilcher I, Kern S, Hrzenjak A, Eichmann TO, Stojakovic T, Scharnagl H, Duta-Mare M, Kratky D, Marsche G, Frank S. Impact of Endothelial Lipase on Cholesterol Efflux Capacity of Serum and High-density Lipoprotein. Sci Rep 2017; 7:12485. [PMID: 28970555 PMCID: PMC5624901 DOI: 10.1038/s41598-017-12882-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/15/2017] [Indexed: 12/31/2022] Open
Abstract
Endothelial lipase (EL) is a potent modulator of the structural and functional properties of HDL. Impact of EL on cholesterol efflux capacity (CEC) of serum and isolated HDL is not well understood and apparently contradictory data were published. Here, we systematically examined the impact of EL on composition and CEC of serum and isolated HDL, in vitro and in vivo, using EL-overexpressing cells and EL-overexpressing mice. CEC was examined in a validated assay using 3H-cholesterol labelled J774 macrophages. In vitro EL-modification of serum resulted in complex alterations, including enrichment of serum with lipid-free/-poor apoA-I, decreased size of human (but not mouse) HDL and altered HDL lipid composition. EL-modification of serum increased CEC, in line with increased lipid-free/-poor apoA-I formation. In contrast, CEC of isolated HDL was decreased likely through altered lipid composition. In contrast to in vitro results, EL-overexpression in mice markedly decreased HDL-cholesterol and apolipoprotein A-I serum levels associated with a decreased CEC of serum. HDL lipid composition was altered, but HDL particle size and CEC were not affected. Our study highlights the multiple and complex effects of EL on HDL composition and function and may help to clarify the seemingly contradictory data found in published articles.
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Affiliation(s)
- Irene Schilcher
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University Graz, Neue Stiftingtalstraße 6/6, 8010, Graz, Austria
| | - Sabine Kern
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Universitätsplatz 4, 8010, Graz, Austria
| | - Andelko Hrzenjak
- Division of Pulmonology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 20, 8036, Graz, Austria.,Ludwig Boltzmann Institute for Lung Vascular Research, Stiftingtalstrasse 24, 8010, Graz, Austria
| | - Thomas O Eichmann
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010, Graz, Austria
| | - Tatjana Stojakovic
- Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria
| | - Hubert Scharnagl
- Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria
| | - Madalina Duta-Mare
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University Graz, Neue Stiftingtalstraße 6/6, 8010, Graz, Austria
| | - Dagmar Kratky
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University Graz, Neue Stiftingtalstraße 6/6, 8010, Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Gunther Marsche
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Universitätsplatz 4, 8010, Graz, Austria. .,BioTechMed-Graz, Graz, Austria.
| | - Saša Frank
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University Graz, Neue Stiftingtalstraße 6/6, 8010, Graz, Austria. .,BioTechMed-Graz, Graz, Austria.
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13
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Schlager S, Vujic N, Korbelius M, Duta-Mare M, Dorow J, Leopold C, Rainer S, Wegscheider M, Reicher H, Ceglarek U, Sattler W, Radovic B, Kratky D. Lysosomal lipid hydrolysis provides substrates for lipid mediator synthesis in murine macrophages. Oncotarget 2017; 8:40037-40051. [PMID: 28402950 PMCID: PMC5522325 DOI: 10.18632/oncotarget.16673] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/19/2017] [Indexed: 11/25/2022] Open
Abstract
Degradation of lysosomal lipids requires lysosomal acid lipase (LAL), the only intracellular lipase known to be active at acidic pH. We found LAL to be expressed in murine immune cells with highest mRNA expression in macrophages and neutrophils. Furthermore, we observed that loss of LAL in mice caused lipid accumulation in white blood cells in the peripheral circulation, which increased in response to an acute inflammatory stimulus. Lal-deficient (-/-) macrophages accumulate neutral lipids, mainly cholesteryl esters, within lysosomes. The cholesteryl ester fraction is particularly enriched in the PUFAs 18:2 and 20:4, important precursor molecules for lipid mediator synthesis. To investigate whether loss of LAL activity affects the generation of lipid mediators and to eliminate potential systemic effects from other cells and tissues involved in the pronounced phenotype of Lal-/- mice, we treated macrophages from Wt mice with the LAL-specific inhibitor LAListat-2. Acute inhibition of LAL resulted in reduced release of 18:2- and 20:4-derived mediators from macrophages, indicating that lipid hydrolysis by LAL is an important source for lipid mediator synthesis in macrophages. We conclude that lysosomes should be considered as organelles that provide precursor molecules for lipid mediators such as eicosanoids.
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Affiliation(s)
- Stefanie Schlager
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
- Boehringer Ingelheim, Vienna, Austria
| | - Nemanja Vujic
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Melanie Korbelius
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Madalina Duta-Mare
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Juliane Dorow
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
- LIFE-Leipzig Research Center for Civilization Diseases, University of Leipzig, Leipzig, Germany
| | - Christina Leopold
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Silvia Rainer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Martin Wegscheider
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Helga Reicher
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Uta Ceglarek
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
- LIFE-Leipzig Research Center for Civilization Diseases, University of Leipzig, Leipzig, Germany
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Branislav Radovic
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Dagmar Kratky
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
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