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Song W, Yang Y, Heizer P, Tu Y, Weston TA, Kim JR, Munguia P, Jung H, Fong JLC, Tran C, Ploug M, Beigneux AP, Young SG, Fong LG. Intracapillary LPL levels in brown adipose tissue, visualized with an antibody-based approach, are regulated by ANGPTL4 at thermoneutral temperatures. Proc Natl Acad Sci U S A 2023; 120:e2219833120. [PMID: 36787365 PMCID: PMC9974459 DOI: 10.1073/pnas.2219833120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 01/18/2023] [Indexed: 02/15/2023] Open
Abstract
Lipoprotein lipase (LPL) is secreted into the interstitial spaces by parenchymal cells and then transported into capillaries by GPIHBP1. LPL carries out the lipolytic processing of triglyceride (TG)-rich lipoproteins (TRLs), but the tissue-specific regulation of LPL is incompletely understood. Plasma levels of TG hydrolase activity after heparin injection are often used to draw inferences about intravascular LPL levels, but the validity of these inferences is unclear. Moreover, plasma TG hydrolase activity levels are not helpful for understanding LPL regulation in specific tissues. Here, we sought to elucidate LPL regulation under thermoneutral conditions (30 °C). To pursue this objective, we developed an antibody-based method to quantify (in a direct fashion) LPL levels inside capillaries. At 30 °C, intracapillary LPL levels fell sharply in brown adipose tissue (BAT) but not heart. The reduced intracapillary LPL levels were accompanied by reduced margination of TRLs along capillaries. ANGPTL4 expression in BAT increased fourfold at 30 °C, suggesting a potential explanation for the lower intracapillary LPL levels. Consistent with that idea, Angptl4 deficiency normalized both LPL levels and TRL margination in BAT at 30 °C. In Gpihbp1-/- mice housed at 30 °C, we observed an ANGPTL4-dependent decrease in LPL levels within the interstitial spaces of BAT, providing in vivo proof that ANGPTL4 regulates LPL levels before LPL transport into capillaries. In conclusion, our studies have illuminated intracapillary LPL regulation under thermoneutral conditions. Our approaches will be useful for defining the impact of genetic variation and metabolic disease on intracapillary LPL levels and TRL processing.
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Affiliation(s)
- Wenxin Song
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Ye Yang
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Patrick Heizer
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Yiping Tu
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Thomas A. Weston
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Joonyoung R. Kim
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Priscilla Munguia
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Hyesoo Jung
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Jared L.-C. Fong
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Caitlyn Tran
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Michael Ploug
- Finsen Laboratory, RigshospitaletDK-2200Copenhagen N, Denmark
- Biotech Research and Innovation Centre, University of CopenhagenDK-220Copenhagen N, Denmark
| | - Anne P. Beigneux
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Stephen G. Young
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Loren G. Fong
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
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Chen NY, Yang Y, Weston TA, Belling JN, Heizer P, Tu Y, Kim P, Edillo L, Jonas SJ, Weiss PS, Fong LG, Young SG. An absence of lamin B1 in migrating neurons causes nuclear membrane ruptures and cell death. Proc Natl Acad Sci U S A 2019; 116:25870-25879. [PMID: 31796586 PMCID: PMC6926041 DOI: 10.1073/pnas.1917225116] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Deficiencies in either lamin B1 or lamin B2 cause both defective migration of cortical neurons in the developing brain and reduced neuronal survival. The neuronal migration abnormality is explained by a weakened nuclear lamina that interferes with nucleokinesis, a nuclear translocation process required for neuronal migration. In contrast, the explanation for impaired neuronal survival is poorly understood. We hypothesized that the forces imparted on the nucleus during neuronal migration result in nuclear membrane (NM) ruptures, causing interspersion of nuclear and cytoplasmic contents-and ultimately cell death. To test this hypothesis, we bred Lmnb1-deficient mice that express a nuclear-localized fluorescent Cre reporter. Migrating neurons within the cortical plate of E18.5 Lmnb1-deficient embryos exhibited NM ruptures, evident by the escape of the nuclear-localized reporter into the cytoplasm and NM discontinuities by electron microscopy. The NM ruptures were accompanied by DNA damage and cell death. The NM ruptures were not observed in nonmigrating cells within the ventricular zone. NM ruptures, DNA damage, and cell death were also observed in cultured Lmnb1-/- and Lmnb2-/- neurons as they migrated away from neurospheres. To test whether mechanical forces on the cell nucleus are relevant to NM ruptures in migrating neurons, we examined cultured Lmnb1-/- neurons when exposed to external constrictive forces (migration into a field of tightly spaced silicon pillars). As the cells entered the field of pillars, there were frequent NM ruptures, accompanied by DNA damage and cell death.
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Affiliation(s)
- Natalie Y Chen
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Ye Yang
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Thomas A Weston
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Jason N Belling
- California NanoSystems Institute, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Chemistry and Biochemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Patrick Heizer
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Yiping Tu
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Paul Kim
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Lovelyn Edillo
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Steven J Jonas
- Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Children's Discovery and Innovation Institute, University of California, Los Angeles, CA 90095
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, CA 90095
| | - Paul S Weiss
- California NanoSystems Institute, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Chemistry and Biochemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Bioengineering, University of California, Los Angeles, CA 90095
- Department of Materials Science and Engineering, University of California, Los Angeles, CA 90095
| | - Loren G Fong
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095;
| | - Stephen G Young
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095;
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Molecular Biology Institute, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
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Kim PH, Luu J, Heizer P, Tu Y, Weston TA, Chen N, Lim C, Li RL, Lin PY, Dunn JCY, Hodzic D, Young SG, Fong LG. Disrupting the LINC complex in smooth muscle cells reduces aortic disease in a mouse model of Hutchinson-Gilford progeria syndrome. Sci Transl Med 2018; 10:eaat7163. [PMID: 30257952 PMCID: PMC6166472 DOI: 10.1126/scitranslmed.aat7163] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 09/07/2018] [Indexed: 12/27/2022]
Abstract
Hutchinson-Gilford progeria syndrome is a disorder of premature aging in children caused by de novo mutations in LMNA that lead to the synthesis of an internally truncated form of prelamin A (commonly called progerin). The production of progerin causes multiple disease phenotypes, including an unusual vascular phenotype characterized by the loss of smooth muscle cells in the arterial media and fibrosis of the adventitia. We show that progerin expression, combined with mechanical stress, promotes smooth muscle cell death. Disrupting the linker of the nucleoskeleton and cytoskeleton (LINC) complex in smooth muscle cells ameliorates the toxic effects of progerin on smooth muscle cells and limits the accompanying adventitial fibrosis.
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Affiliation(s)
- Paul H Kim
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jennings Luu
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Patrick Heizer
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Yiping Tu
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Thomas A Weston
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Natalie Chen
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Christopher Lim
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Robert L Li
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Po-Yu Lin
- Department of Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | - James C Y Dunn
- Department of Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | - Didier Hodzic
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Stephen G Young
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
- Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Loren G Fong
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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He C, Hu X, Weston TA, Jung RS, Heizer P, Tu Y, Ellison R, Matsumoto K, Gerhardt H, Tontonoz P, Fong LG, Young SG, Jiang H. NanoSIMS imaging reveals unexpected heterogeneity in nutrient uptake by brown adipocytes. Biochem Biophys Res Commun 2018; 504:899-902. [PMID: 30224066 DOI: 10.1016/j.bbrc.2018.09.051] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 09/08/2018] [Indexed: 11/16/2022]
Abstract
Heterogeneity in the metabolic properties of adipocytes in white adipose tissue has been well documented. We sought to investigate metabolic heterogeneity in adipocytes of brown adipose tissue (BAT), focusing on heterogeneity in nutrient uptake. To explore the possibility of metabolic heterogeneity in brown adipocytes, we used nanoscale secondary ion mass spectrometry (NanoSIMS) to quantify uptake of lipids in adipocytes interscapular BAT and perivascular adipose tissue (PVAT) after an intravenous injection of triglyceride-rich lipoproteins (TRLs) containing [2H]triglycerides (2H-TRLs). The uptake of deuterated lipids into brown adipocytes was quantified by NanoSIMS. We also examined 13C enrichment in brown adipocytes after administering [13C]glucose or 13C-labeled mixed fatty acids by gastric gavage. The uptake of 2H-TRLs-derived lipids into brown adipocytes was heterogeneous, with 2H enrichment in adjacent adipocytes varying by more than fourfold. We also observed substantial heterogeneity in 13C enrichment in adjacent brown adipocytes after administering [13C]glucose or [13C]fatty acids by gastric gavage. The uptake of nutrients by adjacent brown adipocytes within a single depot is variable, suggesting that there is heterogeneity in the metabolic properties of brown adipocytes.
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Affiliation(s)
- Cuiwen He
- Departments of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Xuchen Hu
- Departments of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Thomas A Weston
- Departments of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Rachel S Jung
- Departments of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Patrick Heizer
- Departments of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Yiping Tu
- Departments of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Rochelle Ellison
- Departments of Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Ken Matsumoto
- VIB Center for Cancer Biology, KU Leuven, Leuven, Belgium
| | - Holger Gerhardt
- VIB Center for Cancer Biology, KU Leuven, Leuven, Belgium; Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Peter Tontonoz
- Departments of Pathology and Laboratory Medicine, University of California, Los Angeles, CA, 90095, USA
| | - Loren G Fong
- Departments of Medicine, University of California, Los Angeles, CA, 90095, USA.
| | - Stephen G Young
- Departments of Medicine, University of California, Los Angeles, CA, 90095, USA; Departments of Human Genetics, University of California, Los Angeles, CA, 90095, USA.
| | - Haibo Jiang
- Departments of Medicine, University of California, Los Angeles, CA, 90095, USA; School of Molecular Sciences and Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth, 6009, Australia.
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He C, Weston TA, Jung RS, Heizer P, Larsson M, Hu X, Allan CM, Tontonoz P, Reue K, Beigneux AP, Ploug M, Holme A, Kilburn M, Guagliardo P, Ford DA, Fong LG, Young SG, Jiang H. NanoSIMS Analysis of Intravascular Lipolysis and Lipid Movement across Capillaries and into Cardiomyocytes. Cell Metab 2018; 27:1055-1066.e3. [PMID: 29719224 PMCID: PMC5945212 DOI: 10.1016/j.cmet.2018.03.017] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [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: 12/14/2017] [Revised: 02/16/2018] [Accepted: 03/24/2018] [Indexed: 10/17/2022]
Abstract
The processing of triglyceride-rich lipoproteins (TRLs) in capillaries provides lipids for vital tissues, but our understanding of TRL metabolism is limited, in part because TRL processing and lipid movement have never been visualized. To investigate the movement of TRL-derived lipids in the heart, mice were given an injection of [2H]triglyceride-enriched TRLs, and the movement of 2H-labeled lipids across capillaries and into cardiomyocytes was examined by NanoSIMS. TRL processing and lipid movement in tissues were extremely rapid. Within 30 s, TRL-derived lipids appeared in the subendothelial spaces and in the lipid droplets and mitochondria of cardiomyocytes. Enrichment of 2H in capillary endothelial cells was not greater than in cardiomyocytes, implying that endothelial cells may not be a control point for lipid movement into cardiomyocytes. Remarkably, a deficiency of the putative fatty acid transport protein CD36, which is expressed highly in capillary endothelial cells, did not impede entry of TRL-derived lipids into cardiomyocytes.
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Affiliation(s)
- Cuiwen He
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Thomas A Weston
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Rachel S Jung
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Patrick Heizer
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Mikael Larsson
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Xuchen Hu
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Christopher M Allan
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Peter Tontonoz
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Karen Reue
- Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Anne P Beigneux
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Michael Ploug
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark; Biotech Research and Innovation Centre, University of Copenhagen, Copenhagen, Denmark
| | - Andrea Holme
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth 6009, Australia
| | - Matthew Kilburn
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth 6009, Australia
| | - Paul Guagliardo
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth 6009, Australia
| | - David A Ford
- Department of Biochemistry and Molecular Biology, Center for Cardiovascular Research, Saint Louis University, St. Louis, MO 63104, USA
| | - Loren G Fong
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Stephen G Young
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Haibo Jiang
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth 6009, Australia.
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Marschall A, Ficjian A, Husic R, Stradner M, Zauner D, Seel W, Simmet N, Klammer A, Heizer P, Brickmann K, Gertler J, Fürst-Moazedi F, Thonhofer R, Hermann J, Graninger W, Quasthoff S, Dejaco C. AB1036 Ultrasound in Carpal Tunnel Syndrome: Predictive Value of Baseline B-Mode and Power Doppler Assessment for Long-Term Functional Outcome. Ann Rheum Dis 2015. [DOI: 10.1136/annrheumdis-2015-eular.5643] [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] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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