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Li Z, Bagchi DP, Zhu J, Bowers E, Yu H, Hardij J, Mori H, Granger K, Skjaerlund J, Mandair G, Abrishami S, Singer K, Hankenson KD, Rosen CJ, MacDougald OA. Constitutive bone marrow adipocytes suppress local bone formation. JCI Insight 2022; 7:160915. [PMID: 36048537 PMCID: PMC9675472 DOI: 10.1172/jci.insight.160915] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 08/31/2022] [Indexed: 12/15/2022] Open
Abstract
BM adipocytes (BMAd) are a unique cell population derived from BM mesenchymal progenitors and marrow adipogenic lineage precursors. Although they have long been considered to be a space filler within bone cavities, recent studies have revealed important physiological roles in hematopoiesis and bone metabolism. To date, the approaches used to study BMAd function have been confounded by contributions by nonmarrow adipocytes or by BM stromal cells. To address this gap in the field, we have developed a BMAd-specific Cre mouse model to deplete BMAds by expression of diphtheria toxin A (DTA) or by deletion of peroxisome proliferator-activated receptor gamma (Pparg). We found that DTA-induced loss of BMAds results in decreased hematopoietic stem and progenitor cell numbers and increased bone mass in BMAd-enriched locations, including the distal tibiae and caudal vertebrae. Elevated bone mass appears to be secondary to enhanced endosteal bone formation, suggesting a local effect caused by depletion of BMAd. Augmented bone formation with BMAd depletion protects mice from bone loss induced by caloric restriction or ovariectomy, and it facilitates the bone-healing process after fracture. Finally, ablation of Pparg also reduces BMAd numbers and largely recapitulates high-bone mass phenotypes observed with DTA-induced BMAd depletion.
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Affiliation(s)
- Ziru Li
- Department of Molecular & Integrative Physiology and
| | | | - Junxiong Zhu
- Department of Orthopedic Surgery, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Emily Bowers
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Hui Yu
- Department of Molecular & Integrative Physiology and
| | - Julie Hardij
- Department of Molecular & Integrative Physiology and
| | - Hiroyuki Mori
- Department of Molecular & Integrative Physiology and
| | | | - Jon Skjaerlund
- Department of Orthopedic Surgery, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Gurjit Mandair
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Simin Abrishami
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Kanakadurga Singer
- Department of Molecular & Integrative Physiology and
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Kurt D. Hankenson
- Department of Orthopedic Surgery, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | | | - Ormond A. MacDougald
- Department of Molecular & Integrative Physiology and
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
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Li Z, Bowers E, Zhu J, Yu H, Hardij J, Bagchi DP, Mori H, Lewis KT, Granger K, Schill RL, Romanelli SM, Abrishami S, Hankenson KD, Singer K, Rosen CJ, MacDougald OA. Lipolysis of bone marrow adipocytes is required to fuel bone and the marrow niche during energy deficits. eLife 2022; 11:e78496. [PMID: 35731039 PMCID: PMC9273217 DOI: 10.7554/elife.78496] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [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: 03/09/2022] [Accepted: 06/21/2022] [Indexed: 11/13/2022] Open
Abstract
To investigate roles for bone marrow adipocyte (BMAd) lipolysis in bone homeostasis, we created a BMAd-specific Cre mouse model in which we knocked out adipose triglyceride lipase (ATGL, Pnpla2 gene). BMAd-Pnpla2-/- mice have impaired BMAd lipolysis, and increased size and number of BMAds at baseline. Although energy from BMAd lipid stores is largely dispensable when mice are fed ad libitum, BMAd lipolysis is necessary to maintain myelopoiesis and bone mass under caloric restriction. BMAd-specific Pnpla2 deficiency compounds the effects of caloric restriction on loss of trabecular bone in male mice, likely due to impaired osteoblast expression of collagen genes and reduced osteoid synthesis. RNA sequencing analysis of bone marrow adipose tissue reveals that caloric restriction induces dramatic elevations in extracellular matrix organization and skeletal development genes, and energy from BMAd is required for these adaptations. BMAd-derived energy supply is also required for bone regeneration upon injury, and maintenance of bone mass with cold exposure.
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Affiliation(s)
- Ziru Li
- University of Michigan Medical School, Department of Molecular & Integrative PhysiologyAnn ArborUnited States
| | - Emily Bowers
- University of Michigan Medical School, Department of PediatricsAnn ArborUnited States
| | - Junxiong Zhu
- Department of Orthopedic Surgery, University of Michigan Medical SchoolAnn ArborUnited States
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Hui Yu
- University of Michigan Medical School, Department of Molecular & Integrative PhysiologyAnn ArborUnited States
| | - Julie Hardij
- University of Michigan Medical School, Department of Molecular & Integrative PhysiologyAnn ArborUnited States
| | - Devika P Bagchi
- University of Michigan Medical School, Department of Molecular & Integrative PhysiologyAnn ArborUnited States
| | - Hiroyuki Mori
- University of Michigan Medical School, Department of Molecular & Integrative PhysiologyAnn ArborUnited States
| | - Kenneth T Lewis
- University of Michigan Medical School, Department of Molecular & Integrative PhysiologyAnn ArborUnited States
| | - Katrina Granger
- University of Michigan Medical School, Department of Molecular & Integrative PhysiologyAnn ArborUnited States
| | - Rebecca L Schill
- University of Michigan Medical School, Department of Molecular & Integrative PhysiologyAnn ArborUnited States
| | - Steven M Romanelli
- University of Michigan Medical School, Department of Molecular & Integrative PhysiologyAnn ArborUnited States
| | - Simin Abrishami
- University of Michigan Medical School, Department of PediatricsAnn ArborUnited States
| | - Kurt D Hankenson
- Department of Orthopedic Surgery, University of Michigan Medical SchoolAnn ArborUnited States
| | - Kanakadurga Singer
- University of Michigan Medical School, Department of Molecular & Integrative PhysiologyAnn ArborUnited States
- University of Michigan Medical School, Department of PediatricsAnn ArborUnited States
| | | | - Ormond A MacDougald
- University of Michigan Medical School, Department of Molecular & Integrative PhysiologyAnn ArborUnited States
- University of Michigan Medical School, Department of Internal MedicineAnn ArborUnited States
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Corsa CAS, Walsh CM, Bagchi DP, Foss Freitas MC, Li Z, Hardij J, Granger K, Mori H, Schill RL, Lewis KT, Maung JN, Azaria RD, Rothberg AE, Oral EA, MacDougald OA. Adipocyte-Specific Deletion of Lamin A/C Largely Models Human Familial Partial Lipodystrophy Type 2. Diabetes 2021; 70:1970-1984. [PMID: 34088712 PMCID: PMC8576431 DOI: 10.2337/db20-1001] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 05/25/2021] [Indexed: 11/13/2022]
Abstract
Mechanisms by which autosomal recessive mutations in Lmna cause familial partial lipodystrophy type 2 (FPLD2) are poorly understood. To investigate the function of lamin A/C in adipose tissue, we created mice with an adipocyte-specific loss of Lmna (Lmna ADKO). Although Lmna ADKO mice develop and maintain adipose tissues in early postnatal life, they show a striking and progressive loss of white and brown adipose tissues as they approach sexual maturity. Lmna ADKO mice exhibit surprisingly mild metabolic dysfunction on a chow diet, but on a high-fat diet they share many characteristics of FPLD2 including hyperglycemia, hepatic steatosis, hyperinsulinemia, and almost undetectable circulating adiponectin and leptin. Whereas Lmna ADKO mice have reduced regulated and constitutive bone marrow adipose tissue with a concomitant increase in cortical bone, FPLD2 patients have reduced bone mass and bone mineral density compared with controls. In cell culture models of Lmna deficiency, mesenchymal precursors undergo adipogenesis without impairment, whereas fully differentiated adipocytes have increased lipolytic responses to adrenergic stimuli. Lmna ADKO mice faithfully reproduce many characteristics of FPLD2 and thus provide a unique animal model to investigate mechanisms underlying Lmna-dependent loss of adipose tissues.
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Affiliation(s)
- Callie A S Corsa
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI
| | - Carolyn M Walsh
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI
| | - Devika P Bagchi
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI
| | - Maria C Foss Freitas
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | - Ziru Li
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI
| | - Julie Hardij
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI
| | - Katrina Granger
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI
| | - Hiroyuki Mori
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI
| | - Rebecca L Schill
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI
| | - Kenneth T Lewis
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI
| | - Jessica N Maung
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI
| | - Ruth D Azaria
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI
| | - Amy E Rothberg
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | - Elif A Oral
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | - Ormond A MacDougald
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI
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Mori H, Dugan CE, Nishii A, Benchamana A, Li Z, Cadenhead TS, Das AK, Evans CR, Overmyer KA, Romanelli SM, Peterson SK, Bagchi DP, Corsa CA, Hardij J, Learman BS, El Azzouny M, Coon JJ, Inoki K, MacDougald OA. The molecular and metabolic program by which white adipocytes adapt to cool physiologic temperatures. PLoS Biol 2021; 19:e3000988. [PMID: 33979328 PMCID: PMC8143427 DOI: 10.1371/journal.pbio.3000988] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 05/24/2021] [Accepted: 04/14/2021] [Indexed: 02/07/2023] Open
Abstract
Although visceral adipocytes located within the body's central core are maintained at approximately 37°C, adipocytes within bone marrow, subcutaneous, and dermal depots are found primarily within the peripheral shell and generally exist at cooler temperatures. Responses of brown and beige/brite adipocytes to cold stress are well studied; however, comparatively little is known about mechanisms by which white adipocytes adapt to temperatures below 37°C. Here, we report that adaptation of cultured adipocytes to 31°C, the temperature at which distal marrow adipose tissues and subcutaneous adipose tissues often reside, increases anabolic and catabolic lipid metabolism, and elevates oxygen consumption. Cool adipocytes rely less on glucose and more on pyruvate, glutamine, and, especially, fatty acids as energy sources. Exposure of cultured adipocytes and gluteal white adipose tissue (WAT) to cool temperatures activates a shared program of gene expression. Cool temperatures induce stearoyl-CoA desaturase-1 (SCD1) expression and monounsaturated lipid levels in cultured adipocytes and distal bone marrow adipose tissues (BMATs), and SCD1 activity is required for acquisition of maximal oxygen consumption at 31°C.
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Affiliation(s)
- Hiroyuki Mori
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Colleen E. Dugan
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Akira Nishii
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Ameena Benchamana
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Ziru Li
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Thomas S. Cadenhead
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Arun K. Das
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Charles R. Evans
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Katherine A. Overmyer
- Morgridge Institute for Research, Madison, Wisconsin, United States of America
- National Center for Quantitative Biology of Complex Systems, Madison, Wisconsin, United States of America
| | - Steven M. Romanelli
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Sydney K. Peterson
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Devika P. Bagchi
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Callie A. Corsa
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Julie Hardij
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Brian S. Learman
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Mahmoud El Azzouny
- Agilent Technologies, Inc., Santa Clara, California, United States of America
| | - Joshua J. Coon
- Morgridge Institute for Research, Madison, Wisconsin, United States of America
- National Center for Quantitative Biology of Complex Systems, Madison, Wisconsin, United States of America
- Department of Biomolecular Chemistry, University of Wisconsin, Madison, Wisconsin, United States of America
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Ken Inoki
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Ormond A. MacDougald
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
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5
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Bagchi DP, Nishii A, Li Z, DelProposto JB, Corsa CA, Mori H, Hardij J, Learman BS, Lumeng CN, MacDougald OA. Wnt/β-catenin signaling regulates adipose tissue lipogenesis and adipocyte-specific loss is rigorously defended by neighboring stromal-vascular cells. Mol Metab 2020; 42:101078. [PMID: 32919095 PMCID: PMC7554252 DOI: 10.1016/j.molmet.2020.101078] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 08/14/2020] [Accepted: 09/06/2020] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVE Canonical Wnt/β-catenin signaling is a well-studied endogenous regulator of mesenchymal cell fate determination, promoting osteoblastogenesis and inhibiting adipogenesis. However, emerging genetic evidence in humans links a number of Wnt pathway members to body fat distribution, obesity, and metabolic dysfunction, suggesting that this pathway also functions in adipocytes. Recent studies in mice have uncovered compelling evidence that the Wnt signaling pathway plays important roles in adipocyte metabolism, particularly under obesogenic conditions. However, complexities in Wnt signaling and differences in experimental models and approaches have thus far limited our understanding of its specific roles in this context. METHODS To investigate roles of the canonical Wnt pathway in the regulation of adipocyte metabolism, we generated adipocyte-specific β-catenin (β-cat) knockout mouse and cultured cell models. We used RNA sequencing, ChIP sequencing, and molecular approaches to assess expression of Wnt targets and lipogenic genes. We then used functional assays to evaluate effects of β-catenin deficiency on adipocyte metabolism, including lipid and carbohydrate handling. In mice maintained on normal chow and high-fat diets, we assessed the cellular and functional consequences of adipocyte-specific β-catenin deletion on adipose tissues and systemic metabolism. RESULTS We report that in adipocytes, the canonical Wnt/β-catenin pathway regulates de novo lipogenesis (DNL) and fatty acid monounsaturation. Further, β-catenin mediates effects of Wnt signaling on lipid metabolism in part by transcriptional regulation of Mlxipl and Srebf1. Intriguingly, adipocyte-specific loss of β-catenin is sensed and defended by CD45-/CD31- stromal cells to maintain tissue-wide Wnt signaling homeostasis in chow-fed mice. With long-term high-fat diet, this compensatory mechanism is overridden, revealing that β-catenin deletion promotes resistance to diet-induced obesity and adipocyte hypertrophy and subsequent protection from metabolic dysfunction. CONCLUSIONS Taken together, our studies demonstrate that Wnt signaling in adipocytes is required for lipogenic gene expression, de novo lipogenesis, and lipid desaturation. In addition, adipose tissues rigorously defend Wnt signaling homeostasis under standard nutritional conditions, such that stromal-vascular cells sense and compensate for adipocyte-specific loss. These findings underscore the critical importance of this pathway in adipocyte lipid metabolism and adipose tissue function.
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Affiliation(s)
- Devika P Bagchi
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Akira Nishii
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Ziru Li
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Jennifer B DelProposto
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Callie A Corsa
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Hiroyuki Mori
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Julie Hardij
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Brian S Learman
- Department of Microbiology and Immunology, University of Buffalo, Buffalo, NY, USA.
| | - Carey N Lumeng
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Ormond A MacDougald
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA; Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA.
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Bagchi DP, Li Z, Corsa CA, Hardij J, Mori H, Learman BS, Lewis KT, Schill RL, Romanelli SM, MacDougald OA. Wntless regulates lipogenic gene expression in adipocytes and protects against diet-induced metabolic dysfunction. Mol Metab 2020; 39:100992. [PMID: 32325263 PMCID: PMC7264081 DOI: 10.1016/j.molmet.2020.100992] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/27/2020] [Accepted: 04/02/2020] [Indexed: 02/08/2023] Open
Abstract
OBJECTIVE Obesity is a key risk factor for many secondary chronic illnesses, including type 2 diabetes and cardiovascular disease. Canonical Wnt/β-catenin signaling is established as an important endogenous inhibitor of adipogenesis. This pathway is operative in mature adipocytes; however, its roles in this context remain unclear due to complexities of Wnt signaling and differences in experimental models. In this study, we used novel cultured cell and mouse models to investigate functional roles of Wnts secreted from adipocytes. METHODS We generated adipocyte-specific Wntless (Wls) knockout mice and cultured cell models to investigate molecular and metabolic consequences of disrupting Wnt secretion from mature adipocytes. To characterize Wls-deficient cultured adipocytes, we evaluated the expression of Wnt target and lipogenic genes and the downstream functional effects on carbohydrate and lipid metabolism. We also investigated the impact of adipocyte-specific Wls deletion on adipose tissues and global glucose metabolism in mice fed normal chow or high-fat diets. RESULTS Many aspects of the Wnt signaling apparatus are expressed and operative in mature adipocytes, including the Wnt chaperone Wntless. Deletion of Wntless in cultured adipocytes results in the inhibition of de novo lipogenesis and lipid monounsaturation, likely through repression of Srebf1 (SREBP1c) and Mlxipl (ChREBP) and impaired cleavage of immature SREBP1c into its active form. Adipocyte-specific Wls knockout mice (Wls-/-) have lipogenic gene expression in adipose tissues and isolated adipocytes similar to that of controls when fed a normal chow diet. However, closer investigation reveals that a subset of Wnts and downstream signaling targets are upregulated within stromal-vascular cells of Wls-/- mice, suggesting that adipose tissues defend loss of Wnt secretion from adipocytes. Interestingly, this compensation is lost with long-term high-fat diet challenges. Thus, after six months of a high-fat diet, Wls-/- mice are characterized by decreased adipocyte lipogenic gene expression, reduced visceral adiposity, and improved glucose homeostasis. CONCLUSIONS Taken together, these studies demonstrate that adipocyte-derived Wnts regulate de novo lipogenesis and lipid desaturation and coordinate the expression of lipogenic genes in adipose tissues. In addition, we report that Wnt signaling within adipose tissues is defended, such that a loss of Wnt secretion from adipocytes is sensed and compensated for by neighboring stromal-vascular cells. With chronic overnutrition, this compensatory mechanism is lost, revealing that Wls-/- mice are resistant to diet-induced obesity, adipocyte hypertrophy, and metabolic dysfunction.
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Affiliation(s)
- Devika P Bagchi
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Ziru Li
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Callie A Corsa
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Julie Hardij
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Hiroyuki Mori
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Brian S Learman
- Department of Microbiology and Immunology, University of Buffalo, Buffalo, NY, USA.
| | - Kenneth T Lewis
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Rebecca L Schill
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Steven M Romanelli
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Ormond A MacDougald
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA; Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA.
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7
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Li Z, Hardij J, Evers SS, Hutch CR, Choi SM, Shao Y, Learman BS, Lewis KT, Schill RL, Mori H, Bagchi DP, Romanelli SM, Kim KS, Bowers E, Griffin C, Seeley RJ, Singer K, Sandoval DA, Rosen CJ, MacDougald OA. G-CSF partially mediates effects of sleeve gastrectomy on the bone marrow niche. J Clin Invest 2019; 129:2404-2416. [PMID: 31063988 PMCID: PMC6546463 DOI: 10.1172/jci126173] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [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: 11/13/2018] [Accepted: 03/05/2019] [Indexed: 01/26/2023] Open
Abstract
Bariatric surgeries are integral to the management of obesity and its metabolic complications. However, these surgeries cause bone loss and increase fracture risk through poorly understood mechanisms. In a mouse model, vertical sleeve gastrectomy (VSG) caused trabecular and cortical bone loss that was independent of sex, body weight, and diet, and this loss was characterized by impaired osteoid mineralization and bone formation. VSG had a profound effect on the bone marrow niche, with rapid loss of marrow adipose tissue, and expansion of myeloid cellularity, leading to increased circulating neutrophils. Following VSG, circulating granulocyte-colony stimulating factor (G-CSF) was increased in mice, and was transiently elevated in a longitudinal study of humans. Elevation of G-CSF was found to recapitulate many effects of VSG on bone and the marrow niche. In addition to stimulatory effects of G-CSF on myelopoiesis, endogenous G-CSF suppressed development of marrow adipocytes and hindered accrual of peak cortical and trabecular bone. Effects of VSG on induction of neutrophils and depletion of marrow adiposity were reduced in mice deficient for G-CSF; however, bone mass was not influenced. Although not a primary mechanism for bone loss with VSG, G-CSF plays an intermediary role for effects of VSG on the bone marrow niche.
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Affiliation(s)
- Ziru Li
- Department of Molecular & Integrative Physiology
| | - Julie Hardij
- Department of Molecular & Integrative Physiology
| | | | | | | | | | | | | | | | | | | | | | | | - Emily Bowers
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Cameron Griffin
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | | | - Kanakadurga Singer
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, Michigan, USA
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Abstract
Most adipocytes exist in discrete depots throughout the body, notably in well-defined white and brown adipose tissues. However, adipocytes also reside within specialized niches, of which the most abundant is within bone marrow. Whereas bone marrow adipose tissue (BMAT) shares many properties in common with white adipose tissue, the distinct functions of BMAT are reflected by its development, regulation, protein secretion, and lipid composition. In addition to its potential role as a local energy reservoir, BMAT also secretes proteins, including adiponectin, RANK ligand, dipeptidyl peptidase-4, and stem cell factor, which contribute to local marrow niche functions and which may also influence global metabolism. The characteristics of BMAT are also distinct depending on whether marrow adipocytes are contained within yellow or red marrow, as these can be thought of as 'constitutive' and 'regulated', respectively. The rBMAT for instance can be expanded or depleted by myriad factors, including age, nutrition, endocrine status and pharmaceuticals. Herein we review the site specificity, age-related development, regulation and metabolic characteristics of BMAT under various metabolic conditions, including the functional interactions with bone and hematopoietic cells.
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Affiliation(s)
- Ziru Li
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Julie Hardij
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Devika P Bagchi
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Erica L Scheller
- Division of Bone and Mineral Diseases, Department of Medicine, Washington University, Saint Louis, MO, United States
| | - Ormond A MacDougald
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, United States.
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Hardij J, Cecchet F, Berquand A, Gheldof D, Chatelain C, Mullier F, Chatelain B, Dogné JM. Characterisation of tissue factor-bearing extracellular vesicles with AFM: comparison of air-tapping-mode AFM and liquid Peak Force AFM. J Extracell Vesicles 2013; 2:21045. [PMID: 24223257 PMCID: PMC3823107 DOI: 10.3402/jev.v2i0.21045] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [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: 04/05/2013] [Revised: 07/02/2013] [Accepted: 07/08/2013] [Indexed: 12/31/2022] Open
Abstract
Introduction Extracellular vesicles (EVs) are shed from cells and carry markers of the parent cells. Vesicles derived from cancer cells reach the bloodstream and locally influence important physiological processes. It has been previously shown that procoagulant vesicles are circulating in patients’ fluids. These EVs are therefore considered as promising biomarkers for the thrombotic risk. Because of their small size, classical methods such as flow cytometry suffer from limitation for their characterisation. Atomic force microscopy (AFM) has been proposed as a promising complementary method for the characterisation of EVs. Objectives The objectives of this study are: (a) to develop and validate AFM with specific antibodies (anti-TF) and (b) to compare air and liquid modes for EVs’ size and number determination as potential biomarkers of the prothrombotic risk. Methods AFM multimode nanoscope III was used for air tapping mode (TM). AFM catalyst was used for liquid Peak Force Tapping (PFT) mode. Vesicles are generated according to Davila et al.'s protocol. Substrates are coated with various concentrations of antibodies, thanks to ethanolamine and glutaraldehyde. Results Vesicles were immobilised on antibody-coated surfaces to select tissue factor (TF)-positive vesicles. The size range of vesicles observed in liquid PFT mode is 6–10 times higher than in air mode. This corresponds to the data found in the literature. Conclusion We recommend liquid PFT mode to analyse vesicles on 5 µg/ml antibody-coated substrates.
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Affiliation(s)
- Julie Hardij
- Department of Pharmacy, NARILIS, Namur Thrombosis and Hemostasis Center (NTHC), University of Namur, Namur, Belgium
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Gheldof D, Hardij J, Cecchet F, Chatelain B, Dogné JM, Mullier F. Thrombin generation assay and transmission electron microscopy: a useful combination to study tissue factor-bearing microvesicles. J Extracell Vesicles 2013; 2:19728. [PMID: 24009889 PMCID: PMC3760633 DOI: 10.3402/jev.v2i0.19728] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [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: 09/18/2012] [Revised: 02/06/2013] [Accepted: 02/12/2013] [Indexed: 11/14/2022] Open
Abstract
Introduction Patients with cancer have a 7- to 10-fold increased risk of developing venous thromboembolism. Circulating microvesicles could be a useful predictive biomarker for venous thromboembolism in cancer. Validated and standardised techniques that could be used to determine the complete microvesicle phenotype are required. Objectives These were two-fold: a) to characterise tissue factor (TF)-bearing microvesicles released by cultured breast cancer cells MDA-MB-231 by flow cytometry (FCM), transmission electron microscopy (TEM) and thrombin generation assay (TGA); and b) to validate the sensitivity and variability intra/inter-assay of TGA as a useful method to study the procoagulant activity (PCA) of microvesicles. Methods Cultured breast cancer cells MDA-MB-231 were incubated for 45 minutes at 37°C. Samples were then centrifuged or not at 4,500 g for 15 minutes, and cells and MVs or MV-containing supernatants were used for TEM, FCM and TGA. In activity assays, microvesicles (i.e. cell-depleted supernatants) were incubated with anti-TF antibodies or with annexin V to assess the contribution of TF and phospholipids to the PCA. Alternatively, supernatants were filtered through 0.1, 0.22, 0.45 or 0.65 µm membranes and subjected to TGA. Results The majority of the PCA was associated with microvesicles smaller than 0.1 µm, and the mean microvesicle size estimated by TEM after 10,000 g centrifugation was 121±54 nm with a majority of vesicles between 100 and 200 nm. Microvesicles derived from 5,000 MDA-MB-231cells/ml were sufficient to significantly increase the thrombin generation of normal pooled plasma. Conclusions TEM, FCM and filtration coupled to TGA represent a useful combination to study the PCA of TF-bearing microvesicles, whatever their size. And it will be interesting to implement these techniques in patients.
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Affiliation(s)
- Damien Gheldof
- Department of Pharmacy, Namur Research Institute for LIfe Sciences, Namur Thrombosis and Hemostasis Center (NTHC), University of Namur, Belgium ; Haematology Laboratory, Namur Research Institute for LIfe Sciences, Namur Thrombosis and Hemostasis Center (NTHC), CHU Mont-Godinne, Université Catholique de Louvain, Belgium
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