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Evangelakos I, Kuhl A, Baguhl M, Schlein C, John C, Rohde JK, Heine M, Heeren J, Worthmann A. Cold-Induced Lipoprotein Clearance in Cyp7b1-Deficient Mice. Front Cell Dev Biol 2022; 10:836741. [PMID: 35478959 PMCID: PMC9038073 DOI: 10.3389/fcell.2022.836741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 12/15/2021] [Accepted: 03/08/2022] [Indexed: 12/12/2022] Open
Abstract
Brown adipose tissue (BAT) has emerged as an appealing therapeutic target for cardio metabolic diseases. BAT is a heat-producing organ and upon activation substantially lowers hyperlipidemia. In response to cold exposure, not only the uptake of lipids into BAT is increased but also the Cyp7b1-mediated synthesis of bile acids (BA) from cholesterol in the liver is triggered. In addition to their role for intestinal lipid digestion, BA act as endocrine signals that can activate thermogenesis in BAT. When exposed to cold temperatures, Cyp7b1−/− mice have compromised BAT function along with reduced fecal bile acid levels. Here, we aim to evaluate the role of Cyp7b1 for BAT-dependent lipid clearance. Using metabolic studies with radioactive tracers, we show that in response to a cold stimulus, BAT-mediated clearance of fatty acids derived from triglyceride-rich lipoproteins (TRL), and their remnants are reduced in Cyp7b1−/− mice. The impaired lipid uptake can be explained by reduced BAT lipoprotein lipase (LPL) levels and compromised organ activity in Cyp7b1−/− mice, which may be linked to impaired insulin signaling. Overall, our findings reveal that alterations of systemic lipoprotein metabolism mediated by cold-activated BAT are dependent, at least in part, on CYP7Β1.
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Affiliation(s)
- Ioannis Evangelakos
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Anastasia Kuhl
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Miriam Baguhl
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Schlein
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Clara John
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Julia K. Rohde
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Markus Heine
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Joerg Heeren
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Anna Worthmann
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- *Correspondence: Anna Worthmann,
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Worthmann A, John C, Rühlemann M, Baguhl M, Schlein C, Heinsen F, Heine M, Mineo C, Fischer M, Scheja L, Franke A, Shaul P, Heeren J. Increased hepatic bile acid production shapes the gut microbiome after cold induced brown adipose tissue activation. Atherosclerosis 2018. [DOI: 10.1016/j.atherosclerosis.2018.06.926] [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: 11/25/2022]
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Worthmann A, John C, Rühlemann MC, Baguhl M, Heinsen FA, Schaltenberg N, Heine M, Schlein C, Evangelakos I, Mineo C, Fischer M, Dandri M, Kremoser C, Scheja L, Franke A, Shaul PW, Heeren J. Cold-induced conversion of cholesterol to bile acids in mice shapes the gut microbiome and promotes adaptive thermogenesis. Nat Med 2017; 23:839-849. [PMID: 28604703 DOI: 10.1038/nm.4357] [Citation(s) in RCA: 196] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 05/17/2017] [Indexed: 12/12/2022]
Abstract
Adaptive thermogenesis is an energy-demanding process that is mediated by cold-activated beige and brown adipocytes, and it entails increased uptake of carbohydrates, as well as lipoprotein-derived triglycerides and cholesterol, into these thermogenic cells. Here we report that cold exposure in mice triggers a metabolic program that orchestrates lipoprotein processing in brown adipose tissue (BAT) and hepatic conversion of cholesterol to bile acids via the alternative synthesis pathway. This process is dependent on hepatic induction of cytochrome P450, family 7, subfamily b, polypeptide 1 (CYP7B1) and results in increased plasma levels, as well as fecal excretion, of bile acids that is accompanied by distinct changes in gut microbiota and increased heat production. Genetic and pharmacological interventions that targeted the synthesis and biliary excretion of bile acids prevented the rise in fecal bile acid excretion, changed the bacterial composition of the gut and modulated thermogenic responses. These results identify bile acids as important metabolic effectors under conditions of sustained BAT activation and highlight the relevance of cholesterol metabolism by the host for diet-induced changes of the gut microbiota and energy metabolism.
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Affiliation(s)
- Anna Worthmann
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Clara John
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Malte C Rühlemann
- Institute of Clinical Molecular Biology, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Miriam Baguhl
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Femke-Anouska Heinsen
- Institute of Clinical Molecular Biology, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Nicola Schaltenberg
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Markus Heine
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Schlein
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ioannis Evangelakos
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Chieko Mineo
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Markus Fischer
- Institute of Food Chemistry, University of Hamburg, Hamburg, Germany
| | - Maura Dandri
- Department of Internal Medicine I, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Ludger Scheja
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Andre Franke
- Institute of Clinical Molecular Biology, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Philip W Shaul
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Joerg Heeren
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Abstract
From September 1991 to October 1992, the cosmic dust detector on the Ulysses spacecraft recorded 11 short bursts, or streams, of dust. These dust grains emanated from the jovian system, and their trajectories were strongly affected by solar wind magnetic field forces. Analyses of the on-board measurements of these fields, and of stream approach directions, show that stream-associated dust grain masses are of the order of 10(-18) gram and dust grain velocities exceed 200 kilometers per second. These masses and velocities are, respectively, about 10(3) times less massive and 5 to 10 times faster than earlier reported.
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Affiliation(s)
- H A Zook
- SN3, NASA Johnson Space Center, Houston, TX 77058, USA. Hamilton, Department of Astronomy, University.
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Grün E, Baguhl M, Hamilton DP, Riemann R, Zook HA, Dermott S, Fechtig H, Gustafson BA, Hanner MS, Horányi M, Khurana KK, Kissel J, Kivelson M, Lindblad BA, Linkert D, Linkert G, Mann I, McDonnell JAM, Morfill GE, Polanskey C, Schwehm G, Srama R. Constraints from Galileo observations on the origin of jovian dust streams. Nature 1996. [DOI: 10.1038/381395a0] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Baguhl M, Hamilton DP, Grün E, Fechtig H, Kissel J, Linkert D, Linkert G, Riemann R, Staubach P, Dermott SF, Hanner MS, Polanskey C, Lindblad BA, McDonnell JA, Morfill GE, Schwehm G, Zook HA. Dust Measurements at High Ecliptic Latitudes. Science 1995; 268:1016-9. [PMID: 17774227 DOI: 10.1126/science.268.5213.1016] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Along Ulysses' path from Jupiter to the south ecliptic pole, the onboard dust detector measured a dust impact rate that varied slowly from 0.2 to 0.5 impacts per day. The dominant component of the dust flux arrived from an ecliptic latitude and longitude of 100 + 10 degrees and 280 degrees +/- 30 degrees which indicates an interstellar origin. An additional flux of small particles, which do not come from the interstellar direction and are unlikely to be zodiacal dust grains, appeared south of -45 degrees latitude. One explanation is that these particles are beta-meteoroids accelerated away from the sun by radiation pressure and electromagnetic forces.
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Abstract
Submicrometer- to micrometer-sized particles were recorded by the Ulysses dust detector within 40 days of the Jupiter flyby. Nine impacts were recorded within 50 Jupiter radii with most of them recorded after closest approach. Three of these impacts are consistent with particles on prograde orbits around Jupiter and the rest are believed to have resulted from gravitationally focused interplanetary dust. From the ratio of the impact rate before the Jupiter flyby to the impact rate after the Jupiter flyby it is concluded that interplanetary dust particles at the distance of Jupiter move on mostly retrograde orbits. On 10 March 1992, Ulysses passed through an intense dust stream. The dust detector recorded 126 impacts within 26 hours. The stream particles were moving on highly inclined and apparently hyperbolic orbits with perihelion distances of >5 astronomical units. Interplanetary dust is lost rather quickly from the solar system through collisions and other mechanisms and must be almost continuously replenished to maintain observed abundances. Dust flux measurements, therefore, give evidence of the recent rates of production from sources such as comets, asteroids, and moons, as well as the possible presence of interstellar grains.
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Affiliation(s)
- E Grün
- Max-Planck-Institut für Kernphysik, Heidelberg, Germany
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