51
|
Bermeo S, Al Saedi A, Vidal C, Khalil M, Pang M, Troen BR, Myers D, Duque G. Treatment with an inhibitor of fatty acid synthase attenuates bone loss in ovariectomized mice. Bone 2019; 122:114-122. [PMID: 30779961 DOI: 10.1016/j.bone.2019.02.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 02/03/2019] [Accepted: 02/15/2019] [Indexed: 02/02/2023]
Abstract
Bone and fat cells have an antagonistic relationship. Adipocytes exert a toxic effect on bone cells in vitro through the secretion of fatty acids, which are synthesized by fatty acid synthase (FAS). Inhibition of FAS in vitro rescues osteoblasts from fat-induced toxicity and cell death. In this study, we hypothesized that FAS inhibition would mitigate the loss of bone mass in ovariectomized (OVX) mice. We treated OVX C57BL/6 mice with cerulenin (a known inhibitor of FAS) for 6 weeks and compared their bone phenotype with vehicle-treated controls. Cerulenin-treated mice exhibited a significant decrease in body weight, triglycerides, leptin, and marrow and subcutaneous fat without changes in serum glucose or calciotropic hormones. These effects were associated with attenuation of bone loss and normalization of the bone phenotype in the cerulenin-treated OVX group compared to the vehicle-treated OVX group. Our results demonstrate that inhibition of FAS enhances bone formation, induces uncoupling between osteoblasts and osteoclasts, and favors mineralization, thus providing evidence that inhibition of FAS could constitute a new anabolic therapy for osteoporosis.
Collapse
Affiliation(s)
- Sandra Bermeo
- Sydney Medical School Nepean, The University of Sydney, Penrith, NSW 2750, Australia; Facultad de Ciencias Básicas y Biomédicas, Universidad Simón Bolívar, Barranquilla, Colombia
| | - Ahmed Al Saedi
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St Albans, VIC 3021, Australia; Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St Albans, VIC 3021, Australia
| | - Christopher Vidal
- Sydney Medical School Nepean, The University of Sydney, Penrith, NSW 2750, Australia
| | - Mamdouh Khalil
- ANZAC Research Institute, Sydney Medical School Concord, The University of Sydney, Concord, NSW 2137, Australia
| | - Manhui Pang
- Division of Geriatrics and Palliative Medicine, Jacobs School of Medicine and Biomedical Sciences and Research Service, Veterans Affairs Western New York Healthcare System, University at Buffalo, Buffalo, NY, USA
| | - Bruce R Troen
- Division of Geriatrics and Palliative Medicine, Jacobs School of Medicine and Biomedical Sciences and Research Service, Veterans Affairs Western New York Healthcare System, University at Buffalo, Buffalo, NY, USA
| | - Damian Myers
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St Albans, VIC 3021, Australia; Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St Albans, VIC 3021, Australia
| | - Gustavo Duque
- Sydney Medical School Nepean, The University of Sydney, Penrith, NSW 2750, Australia; Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St Albans, VIC 3021, Australia; Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St Albans, VIC 3021, Australia.
| |
Collapse
|
52
|
Viallon M, Leporq B, Drinda S, Wilhelmi de Toledo F, Galusca B, Ratiney H, Croisille P. Chemical-Shift-Encoded Magnetic Resonance Imaging and Spectroscopy to Reveal Immediate and Long-Term Multi-Organs Composition Changes of a 14-Days Periodic Fasting Intervention: A Technological and Case Report. Front Nutr 2019; 6:5. [PMID: 30881957 PMCID: PMC6407435 DOI: 10.3389/fnut.2019.00005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 01/14/2019] [Indexed: 12/21/2022] Open
Abstract
Objectives: The aim of this study was to investigate the feasibility of measuring the effects of a 14-day Periodic Fasting (PF) intervention (<200 cal) on multi-organs of primary interest (liver, visceral/subcutaneous/bone marrow fat, muscle) using non-invasive advanced magnetic resonance spectroscopic (MRS) and imaging (MRI) methods. Methods: One subject participated in a 14-day PF under daily supervision of nurses and specialized physicians, ingesting a highly reduced intake: 200 Kcal/day coupled with active walking and drinking at least 3 L of liquids/day. The fasting was preceded by a 7-day pre-fasting vegetarian period and followed by 14 days of stepwise reintroduction of food. The longitudinal study collected imaging and biological data before the fast, at peak fasting, and 7 days, 1 month, and 4 months after re-feeding. Body fat mass in the trunk, abdomen, and thigh, liver and muscle mass, were respectively computed using advanced MRI and MRS signal modeling. Fat fraction, MRI relativity index T2* and susceptibility (Chi), as well as Fatty acid composition, were calculated at all-time points. Results: A decrease in body weight (BW: −9.5%), quadriceps muscle volume (−3.2%), Subcutaneous and Visceral Adipose Tissue (SAT −34.4%; VAT −20.8%), liver fat fraction (PDFF = 1.4 vs. 2.6 % at baseline) but increase in Spine Bone Marrow adipose tissue (BMAT) associated with a 10% increase in global adiposity fraction (PDFF: 54.4 vs. 50.9%) was observed. Femoral BMAT showed minimal changes compared to spinal level, with a slight decrease (−3.1%). Interestingly, fatty acid (FA) pattern changes differed depending on the AT locations. In muscle, all lipids increased after fasting, with a greater increase of intramyocellular lipid (IMCL: from 2.7 to 6.3 mmol/kg) after fasting compared to extramyocellular lipid (EMCL: from 6.2 to 9.5 mmol/kg) as well as Carnosine (6.9 to 8.1 mmol/kg). Heterogenous and reverse changes were also observed after re-feeding depending on the organ. Conclusion: These results suggest that investigating the effects of a 14-day PF intervention using advanced MRI and MRS is feasible. Quantitative MR indexes are a crucial adjunct to further understanding the effective changes in multiple crucial organs especially liver, spin, and muscle, differences between adipose tissue composition and the interplay that occurs during periodic fasting.
Collapse
Affiliation(s)
- Magalie Viallon
- Université de Lyon, Lyon, France.,Centre Hospitalier Universitaire de Saint-Étienne, Saint-Étienne, France.,Université Jean Monnet, Saint-Étienne, France.,CNRS UMR 5520, INSERM U1206, CREATIS, Saint-Étienne, France.,Institut National des Sciences Appliquées de Lyon, Villeurbanne, France
| | - Benjamin Leporq
- Université de Lyon, Lyon, France.,Université Jean Monnet, Saint-Étienne, France.,CNRS UMR 5520, INSERM U1206, CREATIS, Saint-Étienne, France.,Institut National des Sciences Appliquées de Lyon, Villeurbanne, France
| | - Stephan Drinda
- Klinik St. Katharinental, Diessenhofen, Switzerland.,Buchinger Wilhelmi Clinic, Uberlingen, Germany
| | | | - Bogdan Galusca
- Université de Lyon, Lyon, France.,Centre Hospitalier Universitaire de Saint-Étienne, Saint-Étienne, France.,Eating Disorders, Addictions & Extreme Bodyweight Research Group (TAPE) EA, Saint-Étienne, France
| | - Helene Ratiney
- Université de Lyon, Lyon, France.,Université Jean Monnet, Saint-Étienne, France.,CNRS UMR 5520, INSERM U1206, CREATIS, Saint-Étienne, France.,Institut National des Sciences Appliquées de Lyon, Villeurbanne, France
| | - Pierre Croisille
- Université de Lyon, Lyon, France.,Centre Hospitalier Universitaire de Saint-Étienne, Saint-Étienne, France.,Université Jean Monnet, Saint-Étienne, France.,CNRS UMR 5520, INSERM U1206, CREATIS, Saint-Étienne, France.,Institut National des Sciences Appliquées de Lyon, Villeurbanne, France
| |
Collapse
|
53
|
Pino AM, Rodríguez JP. Is fatty acid composition of human bone marrow significant to bone health? Bone 2019; 118:53-61. [PMID: 29258874 DOI: 10.1016/j.bone.2017.12.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 12/15/2017] [Indexed: 12/31/2022]
Abstract
The bone marrow adipose tissue (BMAT) is a conserved component of the marrow microenvironment, providing storage and release of energy and stabilizing the marrow extent. Also, it is recognized both the amount and quality of BMAT are relevant to preserve the functional relationships between BMAT, bone, and blood cell production. In this article we ponder the information supporting the tenet that the quality of BMAT is relevant to bone health. In the human adult the distribution of BMAT is heterogeneous over the entire skeleton, and both BMAT accumulation and bone loss come about with aging in healthy populations. But some pathological conditions which increase BMAT formation lead to bone impairment and fragility. Analysis in vivo of the relative content of saturated and unsaturated fatty acids (FA) in BMAT indicates site-related bone marrow fat composition and an association between increased unsaturation index (UI) and bone health. With aging some impairment ensues in the regulation of bone marrow cells and systemic signals leading to local chronic inflammation. Most of the bone loss diseases which evolve altered BMAT composition have as common factors aging and/or chronic inflammation. Both saturated and unsaturated FAs originate lipid species which are active mediators in the inflammation process. Increased free saturated FAs may lead to lipotoxicity of bone marrow cells. The pro-inflammatory, anti-inflammatory or resolving actions of compounds derived from long chain poly unsaturated FAs (PUFA) on bone cells is varied, and depending on the metabolism of the parent n:3 or n:6 PUFAs series. Taking together the evidence substantiate that marrow adipocyte function is fundamental for an efficient link between systemic and marrow fatty acids to accomplish specific energy or regulatory needs of skeletal and marrow cells. Further, they reveal marrow requirements of PUFAs.
Collapse
Affiliation(s)
- Ana María Pino
- Laboratorio de Biología Celular, INTA, Universidad de Chile, Chile
| | | |
Collapse
|
54
|
Pierce JL, Begun DL, Westendorf JJ, McGee-Lawrence ME. Defining osteoblast and adipocyte lineages in the bone marrow. Bone 2019; 118:2-7. [PMID: 29782940 PMCID: PMC6240509 DOI: 10.1016/j.bone.2018.05.019] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 05/16/2018] [Accepted: 05/16/2018] [Indexed: 12/22/2022]
Abstract
Bone is a complex endocrine organ that facilitates structural support, protection to vital organs, sites for hematopoiesis, and calcium homeostasis. The bone marrow microenvironment is a heterogeneous niche consisting of multipotent musculoskeletal and hematopoietic progenitors and their derivative terminal cell types. Amongst these progenitors, bone marrow mesenchymal stem/stromal cells (BMSCs) may differentiate into osteogenic, adipogenic, myogenic, and chondrogenic lineages to support musculoskeletal development as well as tissue homeostasis, regeneration and repair during adulthood. With age, the commitment of BMSCs to osteogenesis slows, bone formation decreases, fracture risk rises, and marrow adiposity increases. An unresolved question is whether osteogenesis and adipogenesis are co-regulated in the bone marrow. Osteogenesis and adipogenesis are controlled by specific signaling mechanisms, circulating cytokines, and transcription factors such as Runx2 and Pparγ, respectively. One hypothesis is that adipogenesis is the default pathway if osteogenic stimuli are absent. However, recent work revealed that Runx2 and Osx1-expressing preosteoblasts form lipid droplets under pathological and aging conditions. Histone deacetylase 3 (Hdac3) and other epigenetic regulators suppress lipid storage in preosteoblasts and/or control marrow adiposity. Establishing a better understanding of fat storage in bone marrow cells, as well as the osteoblast-adipocyte relationship within the bone marrow niche is necessary to understand the mechanisms underlying disease- and aging-related marrow fat storage and may lead to the development of new therapeutic targets for "fatty bone" and osteoporosis.
Collapse
Affiliation(s)
- J L Pierce
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - D L Begun
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA
| | - J J Westendorf
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA; Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA
| | - M E McGee-Lawrence
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; Department of Orthopaedic Surgery, Augusta University, Augusta, GA, USA.
| |
Collapse
|
55
|
Li W, Wang C, Zhang M, Wu J, Gu Y, Deng Y, Wang J, Zhang X, Feng J, Chen K, Zhu J, Xie J, Zhang J. Young and old adipocytes have differential influence on the development of osteoblasts. Obes Res Clin Pract 2018; 12:520-527. [DOI: 10.1016/j.orcp.2018.06.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 06/08/2018] [Accepted: 06/18/2018] [Indexed: 01/13/2023]
|
56
|
Raffaele M, Barbagallo I, Licari M, Carota G, Sferrazzo G, Spampinato M, Sorrenti V, Vanella L. N-Acetylcysteine (NAC) Ameliorates Lipid-Related Metabolic Dysfunction in Bone Marrow Stromal Cells-Derived Adipocytes. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2018; 2018:5310961. [PMID: 30416532 PMCID: PMC6207898 DOI: 10.1155/2018/5310961] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 09/27/2018] [Indexed: 12/24/2022]
Abstract
Recent experimental data suggest that fatty acids and lipotoxicity could play a role in the initiation and evolution of metabolic bone diseases such as osteoporosis. A functional bone marrow adipose tissue (BMAT) may provide support to surrounding cells and tissues or may serve as a lipid reservoir that protects skeletal osteoblasts from lipotoxicity. The present study examined the effect of N-acetylcysteine (NAC), a powerful antioxidant and precursor of glutathione, commonly used to treat chronic obstructive pulmonary disease, on triglycerides accumulation in bone marrow stromal cells-derived adipocytes. Quantification of Oil Red O stained cells showed that lipid droplets decreased following NAC treatment. Additionally, exposure of bone marrow stromal cells (HS-5) to NAC increased adiponectin, PPARγ, HO-1, and SIRT-1 and increased beta-oxidation markers such as PPARα and PPARδ mRNA levels. As there is now substantial interest in alternative medicine, the observed therapeutic value of NAC should be taken into consideration in diabetic patients.
Collapse
Affiliation(s)
- Marco Raffaele
- Department of Drug Science, Biochemistry Section, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Ignazio Barbagallo
- Department of Drug Science, Biochemistry Section, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Maria Licari
- Department of Drug Science, Biochemistry Section, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Giuseppe Carota
- Department of Drug Science, Biochemistry Section, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Giuseppe Sferrazzo
- Department of Drug Science, Biochemistry Section, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Mariarita Spampinato
- Department of Drug Science, Biochemistry Section, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Valeria Sorrenti
- Department of Drug Science, Biochemistry Section, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Luca Vanella
- Department of Drug Science, Biochemistry Section, University of Catania, Viale A. Doria 6, 95125 Catania, Italy
| |
Collapse
|
57
|
Bani Hassan E, Demontiero O, Vogrin S, Ng A, Duque G. Marrow Adipose Tissue in Older Men: Association with Visceral and Subcutaneous Fat, Bone Volume, Metabolism, and Inflammation. Calcif Tissue Int 2018; 103:164-174. [PMID: 29582133 DOI: 10.1007/s00223-018-0412-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 03/16/2018] [Indexed: 12/16/2022]
Abstract
Marrow (MAT) and subcutaneous (SAT) adipose tissues display different metabolic profiles and varying associations with aging, bone density, and fracture risk. Using a non-invasive imaging methodology, we aimed to investigate the associations between MAT, SAT, and visceral fat (VAT) with bone volume, bone remodeling markers, insulin resistance, and circulating inflammatory mediators in a population of older men. In this cross-sectional study, 96 healthy men (mean age 67 ± 5.5) were assessed for anthropometric parameters, body composition, serum biochemistry, and inflammatory panel. Using single-energy computed tomography images, MAT (in L2 and L3 and both hips), VAT, and SAT (at the level of L2-L3 and L4-L5) were measured employing Slice-O-Matic software (Tomovision), which enables specific tissue demarcation applying previously reported Hounsfield unit thresholds. MAT volume was similar in all anatomical sites and independent of BMI. In all femoral regions of interest (ROIs) there was a strong negative association between bone and MAT volumes (r = - 0.840 to - 0.972, p < 0.001), with location-dependent variations in the lumbar spine. Unlike VAT and SAT, no associations between MAT and serum glucose, inflammatory markers or insulin resistance indicators were found. Bone decline occurred without red marrow expansion; thus lost bone was mainly (if not exclusively) replaced by MAT. In conclusion, strong inverse correlations between MAT and bone mass, which have been previously observed in women, were also confirmed in older men. However, MAT volume in all ROIs was interrelated and unlike women, mainly independent of VAT or SAT. The lack of strong association between MAT vs VAT/SAT, and its discordant associations with metabolic and inflammatory mediators provide further evidence on MAT's distinct attributes in older men.
Collapse
Affiliation(s)
- Ebrahim Bani Hassan
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, VIC, Australia
- Department of Medicine-Western Health, The University of Melbourne, St. Albans, VIC, Australia
| | - Oddom Demontiero
- Sydney Medical School Nepean, The University of Sydney, Sydney, NSW, Australia
| | - Sara Vogrin
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, VIC, Australia
- Department of Medicine-Western Health, The University of Melbourne, St. Albans, VIC, Australia
| | - Alvin Ng
- Department of Endocrinology, Singapore National Hospital, Singapore, Singapore
| | - Gustavo Duque
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, VIC, Australia.
- Department of Medicine-Western Health, The University of Melbourne, St. Albans, VIC, Australia.
| |
Collapse
|
58
|
Martel D, Leporq B, Bruno M, Regatte RR, Honig S, Chang G. Chemical shift-encoded MRI for assessment of bone marrow adipose tissue fat composition: Pilot study in premenopausal versus postmenopausal women. Magn Reson Imaging 2018; 53:148-155. [PMID: 30006022 DOI: 10.1016/j.mri.2018.07.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 07/03/2018] [Accepted: 07/05/2018] [Indexed: 12/27/2022]
Abstract
OBJECT To quantify and compare subregional proximal femur bone marrow fat composition in premenopausal and postmenopausal women using chemical shift-encoded-MRI (CSE-MRI). MATERIALS AND METHODS A multi gradient-echo sequence at 3 T was used to scan both hips of premenopausal (n = 9) and postmenopausal (n = 18) women. Subregional fat composition (saturation, poly-unsaturation, mono-unsaturation) was quantitatively assessed in the femoral head, femoral neck, Ward's triangle, greater trochanter, and proximal shaft in bone marrow adipose tissue and separately within red and yellow marrow adipose tissue. RESULTS Significant differences in fat composition in postmenopausal compared to premenopausal women, which varied depending on the subregion analyzed, were found. Within both whole and yellow marrow adipose tissue, postmenopausal women demonstrated higher saturation (+14.7% to +43.3%), lower mono- (-11.4% to -33%) and polyunsaturation (-52 to -83%) (p < 0.05). Within red marrow adipose tissue, postmenopausal women demonstrated lower fat quantity (-16% to -24%) and decreased polyunsaturation (-80 to -120%) in the femoral neck, greater trochanter, and Ward's triangle (p < 0.05). CONCLUSION CSE-MRI can be used to detect subregional differences in proximal femur marrow adipose tissue composition between pre- and post-menopausal women in clinically feasible scan times.
Collapse
Affiliation(s)
- Dimitri Martel
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York City, NY, USA.
| | - Benjamin Leporq
- University of Lyon, Laboratoire CREATIS, CNRS UMR 5220, Inserm U1206, INSA-Lyon, UJM Saint-Etienne, UCBL Lyon 1, Lyon, France
| | - Mary Bruno
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York City, NY, USA
| | - Ravinder R Regatte
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York City, NY, USA
| | - Stephen Honig
- Osteoporosis Center, Hospital for Joint Diseases, New York University School of Medicine, New York City, NY, USA
| | - Gregory Chang
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York City, NY, USA
| |
Collapse
|
59
|
Xu J, Qiu X, Liang Z, Smiley-Jewell S, Lu F, Yu M, Pinkerton KE, Zhao D, Shi B. Exposure to tobacco smoke increases bone loss in spontaneously hypertensive rats. Inhal Toxicol 2018; 30:229-238. [PMID: 30257116 DOI: 10.1080/08958378.2018.1506838] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 06/27/2018] [Accepted: 07/23/2018] [Indexed: 01/12/2023]
Abstract
PURPOSE To define if exposure to tobacco smoke (TS) could induce reduction of bone mass and impairment of bone architecture, features observed in osteoporosis in normotensive rats and the influence of TS exposure on the osteoporotic features exhibited in the spontaneously hypertensive (SH) rats. METHODS Normotensive Wistar Kyoto (WKY) and SH rats were exposed to filtered air or TS for 8 weeks, then their proximal femurs were extracted for micro-computed tomography (micro-CT) assessment, histological and immune-histological examinations to quantify the adverse influence of TS exposure on the bone mass and density, as well as bone architecture. RESULTS We found that TS exposure not only induced significant decreases in bone mineral density (BMD), bone volume (BV), cortical and trabecular thickness (Ct.Th and Tb.Th), trabecular surface area (Tb.Ar), expression of hypoxia-inducible factor-1α (HIF-1α) in the trabecular marrow, delayed ossification of cartilage, as well as statistical increases in trabecular separation (Tb.SP) and the number of trabecular marrow adipocytes in both WKY and SH rats, but also exacerbated multiple features of osteoporosis exhibited in SH rats, including decreased BMD, Ct.Th, Tb.Ar, HIF-1α expression, delayed cartilage ossification, and increased Tb.SP. CONCLUSIONS Our results show that TS exposure can reduce bone mass and impair bone architecture and exacerbate multiple features of osteoporosis exhibited in SH rats.
Collapse
Affiliation(s)
- Jingyi Xu
- a Department of Endocrinology , First Affiliated Hospital of Xi'an Jiaotong University , Xi'an , China
| | - Xing Qiu
- b Department of Orthopaedics , Affiliated Zhongshan Hospital of Dalian University , Dalian , China
| | - Zhou Liang
- b Department of Orthopaedics , Affiliated Zhongshan Hospital of Dalian University , Dalian , China
| | | | - Faqiang Lu
- b Department of Orthopaedics , Affiliated Zhongshan Hospital of Dalian University , Dalian , China
| | - Mang Yu
- d Center for Clinical Sciences Research , Stanford University School of Medicine , Stanford , CA , USA
| | - Kent E Pinkerton
- c Center for Health and the Environment , University of California , Davis CA , USA
| | - Dewei Zhao
- b Department of Orthopaedics , Affiliated Zhongshan Hospital of Dalian University , Dalian , China
| | - Bingyin Shi
- a Department of Endocrinology , First Affiliated Hospital of Xi'an Jiaotong University , Xi'an , China
| |
Collapse
|
60
|
Abstract
PURPOSE OF REVIEW Bone marrow fat expresses mixed characteristics, which could correspond to white, brown, and beige types of fat. Marrow fat could act as either energy storing and adipokine secreting white fat or as a source of energy for hematopoiesis and bone metabolism, thus acting as brown fat. However, there is also a negative interaction between marrow fat and other elements of the bone marrow milieu, which is known as lipotoxicity. In this review, we will describe the good and bad roles of marrow fat in the bone, while focusing on the specific components of the negative effect of marrow fat on bone metabolism. RECENT FINDINGS Lipotoxicity in the bone is exerted by bone marrow fat through the secretion of adipokines and free fatty acids (FFA) (predominantly palmitate). High levels of FFA found in the bone marrow of aged and osteoporotic bone are associated with decreased osteoblastogenesis and bone formation, decreased hematopoiesis, and increased osteoclastogenesis. In addition, FFA such as palmitate and stearate induce apoptosis and dysfunctional autophagy in the osteoblasts, thus affecting their differentiation and function. Regulation of marrow fat could become a therapeutic target for osteoporosis. Inhibition of the synthesis of FFA by marrow fat could facilitate osteoblastogenesis and bone formation while affecting osteoclastogenesis. However, further studies testing this hypothesis are still required.
Collapse
Affiliation(s)
- Lakshman Singh
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, Level 3 WCHRE, 176 Furlong Road, St. Albans, VIC, 3021, Australia
- Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St. Albans, VIC, Australia
| | - Sonia Tyagi
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, Level 3 WCHRE, 176 Furlong Road, St. Albans, VIC, 3021, Australia
- Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St. Albans, VIC, Australia
| | - Damian Myers
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, Level 3 WCHRE, 176 Furlong Road, St. Albans, VIC, 3021, Australia
- Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St. Albans, VIC, Australia
| | - Gustavo Duque
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, Level 3 WCHRE, 176 Furlong Road, St. Albans, VIC, 3021, Australia.
- Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St. Albans, VIC, Australia.
| |
Collapse
|
61
|
Abstract
Marrow adipocytes, collectively termed marrow adipose tissue (MAT), reside in the bone marrow in close contact to bone cells and haematopoietic cells. Marrow adipocytes arise from the mesenchymal stem cell and share their origin with the osteoblast. Shifts in the lineage allocation of the mesenchymal stromal cell could potentially explain the association between increased MAT and increased fracture risk in diseases such as postmenopausal osteoporosis, anorexia nervosa and diabetes. Functionally, marrow adipocytes secrete adipokines, such as adiponectin, and cytokines, such as RANK ligand and stem cell factor. These mediators can influence both bone remodelling and haematopoiesis by promoting bone resorption and haematopoietic recovery following chemotherapy. In addition, marrow adipocytes can secrete free fatty acids, acting as a energy supply for bone and haematopoietic cells. However, this induced lipolysis is also used by neoplastic cells to promote survival and proliferation. Therefore, MAT could represent a new therapeutic target for multiple diseases from osteoporosis to leukaemia, although the exact characteristics and role of the marrow adipocyte in health and diseases remain to be determined.
Collapse
Affiliation(s)
- A G Veldhuis-Vlug
- Department of Endocrinology and Metabolism, Academic Medical Center, Amsterdam, The Netherlands
- Center for Clinical and Translational Research, Maine Medical Center Research Institute, Scarborough, ME, USA
| | - C J Rosen
- Center for Clinical and Translational Research, Maine Medical Center Research Institute, Scarborough, ME, USA
| |
Collapse
|
62
|
Ponti F, Guerri S, Sassi C, Battista G, Guglielmi G, Bazzocchi A. Imaging of diabetic bone. Endocrine 2017; 58:426-441. [PMID: 28293856 DOI: 10.1007/s12020-017-1278-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 02/24/2017] [Indexed: 01/02/2023]
Abstract
Diabetes is an important concern in terms of medical and socioeconomic costs; a high risk for low-trauma fractures has been reported in patients with both type 1 and type 2 diabetes. The mechanism involved in the increased fracture risk from diabetes is highly complex and still not entirely understood; obesity could play an important role: recent evidence suggests that the influence of fat on bone is mainly dependent on the pattern of regional fat deposition and that an increased amount of visceral adipose tissue negatively affects skeletal health.Correct and timely individuation of people with high fracture risk is critical for both prevention and treatment: Dual-energy X-ray Absorptiometry (currently the "gold standard" for diagnosis of osteoporosis) underestimates fracture risk in diabetic patients and therefore is not sufficient by itself to investigate bone status. This paper is focused on imaging, covering different modalities involved in the evaluation of skeletal deterioration in diabetes, discussing the limitations of conventional methods and exploring the potential of new tools and recent high-resolution techniques, with the intent to provide interesting insight into pathophysiology and fracture risk.
Collapse
Affiliation(s)
- Federico Ponti
- Diagnostic and Interventional Radiology, The "Rizzoli" Orthopaedic Institute, Via G. C. Pupilli 1, 40136, Bologna, Italy
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), Division of Radiology S.Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy
| | - Sara Guerri
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), Division of Radiology S.Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy
| | - Claudia Sassi
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), Division of Radiology S.Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy
| | - Giuseppe Battista
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), Division of Radiology S.Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy
| | - Giuseppe Guglielmi
- Department of Radiology, University of Foggia, Viale Luigi Pinto 1, 71100, Foggia, Italy
- Department of Radiology, Scientific Institute "Casa Sollievo della Sofferenza" Hospital, Viale Cappuccini 1, 71013, San Giovanni Rotondo, Foggia, Italy
| | - Alberto Bazzocchi
- Diagnostic and Interventional Radiology, The "Rizzoli" Orthopaedic Institute, Via G. C. Pupilli 1, 40136, Bologna, Italy.
| |
Collapse
|
63
|
Abstract
PURPOSE OF REVIEW Bone disease is a defining characteristic of multiple myeloma (MM) and the major cause of morbidity. It manifests as lytic lesions or osteopenia and is often associated with severe pain, pathological fracture, spinal cord compression, vertebral collapse, and hypercalcemia. Here, we have reviewed recent data on understanding its biology and treatment. RECENT FINDINGS The imbalance between bone regeneration and bone resorption underlies the pathogenesis of osteolytic bone disease. Increased osteoclast proliferation and activity accompanied by inhibition of bone-forming osteoblasts leads to progressive bone loss and lytic lesions. Although tremendous progress has been made, MM remains an incurable disease. Novel agents targeting bone disease are under investigation with the goal of not only preventing bone loss and improving bone quality but also harnessing MM tumor growth. Current data illustrate that the interactions between MM cells and the tumor-bone microenvironment contribute to the bone disease and continued MM progression. A better understanding of this microenvironment is critical for novel therapeutic treatments of both MM and associated bone disease.
Collapse
Affiliation(s)
- Cristina Panaroni
- Center for Multiple Myeloma, Massachusetts General Hospital Cancer Center, Professional Office Building 216, 55 Fruit Street, Boston, MA, 02114, USA
- Harvard Medical School, Boston, MA, 02115, USA
| | - Andrew J Yee
- Center for Multiple Myeloma, Massachusetts General Hospital Cancer Center, Professional Office Building 216, 55 Fruit Street, Boston, MA, 02114, USA
- Harvard Medical School, Boston, MA, 02115, USA
| | - Noopur S Raje
- Center for Multiple Myeloma, Massachusetts General Hospital Cancer Center, Professional Office Building 216, 55 Fruit Street, Boston, MA, 02114, USA.
- Harvard Medical School, Boston, MA, 02115, USA.
| |
Collapse
|
64
|
Suchacki KJ, Roberts F, Lovdel A, Farquharson C, Morton NM, MacRae VE, Cawthorn WP. Skeletal energy homeostasis: a paradigm of endocrine discovery. J Endocrinol 2017; 234:R67-R79. [PMID: 28455432 DOI: 10.1530/joe-17-0147] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 04/28/2017] [Indexed: 12/15/2022]
Abstract
Throughout the last decade, significant developments in cellular, molecular and mouse models have revealed major endocrine functions of the skeleton. More recent studies have evolved the interplay between bone-specific hormones, the skeleton, marrow adipose tissue, muscle and the brain. This review focuses on literature from the last decade, addressing the endocrine regulation of global energy metabolism via the skeleton. In addition, we will highlight several recent studies that further our knowledge of new endocrine functions of some organs; explore remaining unanswered questions; and, finally, we will discuss future directions for this more complex era of bone biology research.
Collapse
Affiliation(s)
- Karla J Suchacki
- The Queen's Medical Research InstituteThe University of Edinburgh, Edinburgh, UK
| | - Fiona Roberts
- The Roslin InstituteThe University of Edinburgh, Easter Bush, Midltohian, UK
| | - Andrea Lovdel
- The Queen's Medical Research InstituteThe University of Edinburgh, Edinburgh, UK
| | - Colin Farquharson
- The Roslin InstituteThe University of Edinburgh, Easter Bush, Midltohian, UK
| | - Nik M Morton
- The Queen's Medical Research InstituteThe University of Edinburgh, Edinburgh, UK
| | - Vicky E MacRae
- The Roslin InstituteThe University of Edinburgh, Easter Bush, Midltohian, UK
| | - William P Cawthorn
- The Queen's Medical Research InstituteThe University of Edinburgh, Edinburgh, UK
| |
Collapse
|
65
|
Craft CS, Scheller EL. Evolution of the Marrow Adipose Tissue Microenvironment. Calcif Tissue Int 2017; 100:461-475. [PMID: 27364342 PMCID: PMC5618436 DOI: 10.1007/s00223-016-0168-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 06/21/2016] [Indexed: 12/29/2022]
Abstract
Adipocytes of the marrow adipose tissue (MAT) are distributed throughout the skeleton, are embedded in extracellular matrix, and are surrounded by cells of the hematopoietic and osteogenic lineages. MAT is a persistent component of the skeletal microenvironment and has the potential to impact local processes including bone accrual and hematopoietic function. In this review, we discuss the initial evolution of MAT in vertebrate lineages while emphasizing comparisons to the development of peripheral adipose, hematopoietic, and skeletal tissues. We then apply these evolutionary clues to define putative functions of MAT. Lastly, we explore the regulation of MAT by two major components of its microenvironment, the extracellular matrix and the nerves embedded within. The extracellular matrix and nerves contribute to both rapid and continuous modification of the MAT niche and may help to explain evolutionary conserved mechanisms underlying the coordinated regulation of blood, bone, and MAT within the skeleton.
Collapse
Affiliation(s)
- Clarissa S Craft
- Department of Cell Biology & Physiology, Washington University, Saint Louis, MO, 63110, USA
- Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University, Saint Louis, MO, 63110, USA
| | - Erica L Scheller
- Department of Cell Biology & Physiology, Washington University, Saint Louis, MO, 63110, USA.
- Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University, Saint Louis, MO, 63110, USA.
| |
Collapse
|
66
|
Chkourko Gusky H, Diedrich J, MacDougald OA, Podgorski I. Omentum and bone marrow: how adipocyte-rich organs create tumour microenvironments conducive for metastatic progression. Obes Rev 2016; 17:1015-1029. [PMID: 27432523 PMCID: PMC5056818 DOI: 10.1111/obr.12450] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 05/31/2016] [Accepted: 06/01/2016] [Indexed: 12/30/2022]
Abstract
A number of clinical studies have linked adiposity with increased cancer incidence, progression and metastasis, and adipose tissue is now being credited with both systemic and local effects on tumour development and survival. Adipocytes, a major component of benign adipose tissue, represent a significant source of lipids, cytokines and adipokines, and their presence in the tumour microenvironment substantially affects cellular trafficking, signalling and metabolism. Cancers that have a high predisposition to metastasize to the adipocyte-rich host organs are likely to be particularly affected by the presence of adipocytes. Although our understanding of how adipocytes influence tumour progression has grown significantly over the last several years, the mechanisms by which adipocytes regulate the metastatic niche are not well-understood. In this review, we focus on the omentum, a visceral white adipose tissue depot, and the bone, a depot for marrow adipose tissue, as two distinct adipocyte-rich organs that share common characteristic: they are both sites of significant metastatic growth. We highlight major differences in origin and function of each of these adipose depots and reveal potential common characteristics that make them environments that are attractive and conducive to secondary tumour growth. Special attention is given to how omental and marrow adipocytes modulate the tumour microenvironment by promoting angiogenesis, affecting immune cells and altering metabolism to support growth and survival of metastatic cancer cells.
Collapse
Affiliation(s)
- H Chkourko Gusky
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, USA
| | - J Diedrich
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, USA.,Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, USA
| | - O A MacDougald
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA.,Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - I Podgorski
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, USA. .,Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, USA.
| |
Collapse
|
67
|
Lombardi G, Sanchis-Gomar F, Perego S, Sansoni V, Banfi G. Implications of exercise-induced adipo-myokines in bone metabolism. Endocrine 2016; 54:284-305. [PMID: 26718191 DOI: 10.1007/s12020-015-0834-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 12/14/2015] [Indexed: 12/12/2022]
Abstract
Physical inactivity has been recognized, by the World Health Organization as the fourth cause of death (5.5 % worldwide). On the contrary, physical activity (PA) has been associated with improved quality of life and decreased risk of several diseases (i.e., stroke, hypertension, myocardial infarction, obesity, malignancies). Bone turnover is profoundly affected from PA both directly (load degree is the key determinant for BMD) and indirectly through the activation of several endocrine axes. Several molecules, secreted by muscle (myokines) and adipose tissues (adipokines) in response to exercise, are involved in the fine regulation of bone metabolism in response to the energy availability. Furthermore, bone regulates energy metabolism by communicating its energetic needs thanks to osteocalcin which acts on pancreatic β-cells and adipocytes. The beneficial effects of exercise on bone metabolism depends on the intermittent exposure to myokines (i.e., irisin, IL-6, LIF, IGF-I) which, instead, act as inflammatory/pro-resorptive mediators when chronically elevated; on the other hand, the reduction in the circulating levels of adipokines (i.e., leptin, visfatin, adiponectin, resistin) sustains these effects as well as improves the whole-body metabolic status. The aim of this review is to highlight the newest findings about the exercise-dependent regulation of these molecules and their role in the fine regulation of bone metabolism.
Collapse
Affiliation(s)
- Giovanni Lombardi
- Laboratory of Experimental Biochemistry & Molecular Biology, I.R.C.C.S. Istituto Ortopedico Galeazzi, Via Riccardo Galeazzi 4, 20161, Milan, Italy.
| | | | - Silvia Perego
- Laboratory of Experimental Biochemistry & Molecular Biology, I.R.C.C.S. Istituto Ortopedico Galeazzi, Via Riccardo Galeazzi 4, 20161, Milan, Italy
| | - Veronica Sansoni
- Laboratory of Experimental Biochemistry & Molecular Biology, I.R.C.C.S. Istituto Ortopedico Galeazzi, Via Riccardo Galeazzi 4, 20161, Milan, Italy
| | - Giuseppe Banfi
- Laboratory of Experimental Biochemistry & Molecular Biology, I.R.C.C.S. Istituto Ortopedico Galeazzi, Via Riccardo Galeazzi 4, 20161, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
| |
Collapse
|
68
|
Scheller EL, Cawthorn WP, Burr AA, Horowitz MC, MacDougald OA. Marrow Adipose Tissue: Trimming the Fat. Trends Endocrinol Metab 2016; 27:392-403. [PMID: 27094502 PMCID: PMC4875855 DOI: 10.1016/j.tem.2016.03.016] [Citation(s) in RCA: 137] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 03/25/2016] [Accepted: 03/29/2016] [Indexed: 02/07/2023]
Abstract
Marrow adipose tissue (MAT) is a unique fat depot, located in the skeleton, that has the potential to contribute to both local and systemic metabolic processes. In this review we highlight several recent conceptual developments pertaining to the origin and function of MAT adipocytes; consider the relationship of MAT to beige, brown, and white adipose depots; explore MAT expansion and turnover in humans and rodents; and discuss future directions for MAT research in the context of endocrine function and metabolic disease. MAT has the potential to exert both local and systemic effects on metabolic homeostasis, skeletal remodeling, hematopoiesis, and the development of bone metastases. The diversity of these functions highlights the breadth of the potential impact of MAT on health and disease.
Collapse
Affiliation(s)
- Erica L Scheller
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA; Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University, Saint Louis, MO 63110, USA.
| | - William P Cawthorn
- University/BHF Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Aaron A Burr
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Mark C Horowitz
- Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Ormond A MacDougald
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA.
| |
Collapse
|
69
|
Miranda M, Pino AM, Fuenzalida K, Rosen CJ, Seitz G, Rodríguez JP. Characterization of Fatty Acid Composition in Bone Marrow Fluid From Postmenopausal Women: Modification After Hip Fracture. J Cell Biochem 2016; 117:2370-6. [PMID: 27416518 DOI: 10.1002/jcb.25534] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 03/04/2016] [Indexed: 12/16/2022]
Abstract
Bone marrow adipose tissue (BMAT) is associated with low bone mass, although the functional consequences for skeletal maintenance of increased BMAT are currently unclear. BMAT might have a role in systemic energy metabolism, and could be an energy source as well as an endocrine organ for neighboring bone cells, releasing cytokines, adipokines and free fatty acids into the bone marrow microenvironment. The aim of the present report was to compare the fatty acid composition in the bone marrow supernatant fluid (BMSF) and blood plasma of postmenopausal women women (65-80 years old). BMSF was obtained after spinning the aspirated bone marrow samples; donors were classified as control, osteopenic or osteoporotic after dual-energy X-ray absorptiometry. Total lipids from human bone marrow fluid and plasma were extracted, converted to the corresponding methyl esters, and finally analyzed by a gas chromatographer coupled with a mass spectrometer. Results showed that fatty acid composition in BMSF was dynamic and distinct from blood plasma, implying significance in the locally produced lipids. The fatty acid composition in the BMSF was enriched in saturated fatty acid and decreased in unsaturated fatty acids as compared to blood plasma, but this relationship switched in women who suffered a hip fracture. On the other hand, there was no relationship between BMSF and bone mineral density. In conclusion, lipid composition of BMSF is distinct from the circulatory compartment, most likely reflecting the energy needs of the marrow compartment. J. Cell. Biochem. 117: 2370-2376, 2016. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Melissa Miranda
- Laboratorio de Biología Celular, INTA, Universidad de Chile, Santiago, Chile
| | - Ana María Pino
- Laboratorio de Biología Celular, INTA, Universidad de Chile, Santiago, Chile
| | - Karen Fuenzalida
- Laboratorio de Enfermedades Metabólicas y Genéticas, INTA, Universidad de Chile, Santiago, Chile
| | | | | | - J Pablo Rodríguez
- Laboratorio de Biología Celular, INTA, Universidad de Chile, Santiago, Chile
| |
Collapse
|
70
|
Hardouin P, Rharass T, Lucas S. Bone Marrow Adipose Tissue: To Be or Not To Be a Typical Adipose Tissue? Front Endocrinol (Lausanne) 2016; 7:85. [PMID: 27445987 PMCID: PMC4928601 DOI: 10.3389/fendo.2016.00085] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 06/21/2016] [Indexed: 12/12/2022] Open
Abstract
Bone marrow adipose tissue (BMAT) emerges as a distinct fat depot whose importance has been proved in the bone-fat interaction. Indeed, it is well recognized that adipokines and free fatty acids released by adipocytes can directly or indirectly interfere with cells of bone remodeling or hematopoiesis. In pathological states, such as osteoporosis, each of adipose tissues - subcutaneous white adipose tissue (WAT), visceral WAT, brown adipose tissue (BAT), and BMAT - is differently associated with bone mineral density (BMD) variations. However, compared with the other fat depots, BMAT displays striking features that makes it a substantial actor in bone alterations. BMAT quantity is well associated with BMD loss in aging, menopause, and other metabolic conditions, such as anorexia nervosa. Consequently, BMAT is sensed as a relevant marker of a compromised bone integrity. However, analyses of BMAT development in metabolic diseases (obesity and diabetes) are scarce and should be, thus, more systematically addressed to better apprehend the bone modifications in that pathophysiological contexts. Moreover, bone marrow (BM) adipogenesis occurs throughout the whole life at different rates. Following an ordered spatiotemporal expansion, BMAT has turned to be a heterogeneous fat depot whose adipocytes diverge in their phenotype and their response to stimuli according to their location in bone and BM. In vitro, in vivo, and clinical studies point to a detrimental role of BM adipocytes (BMAs) throughout the release of paracrine factors that modulate osteoblast and/or osteoclast formation and function. However, the anatomical dissemination and the difficulties to access BMAs still hamper our understanding of the relative contribution of BMAT secretions compared with those of peripheral adipose tissues. A further characterization of the phenotype and the functional regulation of BMAs are ever more required. Based on currently available data and comparison with other fat tissues, this review addresses the originality of the BMAT with regard to its development, anatomy, metabolic properties, and response to physiological cues.
Collapse
Affiliation(s)
- Pierre Hardouin
- Laboratory of Pathophysiology of Inflammatory Bone Diseases PMOI, University of Littoral-Opale Coast ULCO, Boulogne sur Mer, France
| | - Tareck Rharass
- Laboratory of Pathophysiology of Inflammatory Bone Diseases PMOI, University of Littoral-Opale Coast ULCO, Boulogne sur Mer, France
| | - Stéphanie Lucas
- Laboratory of Pathophysiology of Inflammatory Bone Diseases PMOI, University of Littoral-Opale Coast ULCO, Boulogne sur Mer, France
- *Correspondence: Stéphanie Lucas,
| |
Collapse
|
71
|
Gillet C, Spruyt D, Rigutto S, Dalla Valle A, Berlier J, Louis C, Debier C, Gaspard N, Malaisse WJ, Gangji V, Rasschaert J. Oleate Abrogates Palmitate-Induced Lipotoxicity and Proinflammatory Response in Human Bone Marrow-Derived Mesenchymal Stem Cells and Osteoblastic Cells. Endocrinology 2015; 156:4081-93. [PMID: 26327577 DOI: 10.1210/en.2015-1303] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Osteoporosis is a metabolic bone disease associated with unequilibrated bone remodeling resulting from decreased bone formation and/or increased bone resorption, leading to progressive bone loss. In osteoporotic patients, low bone mass is associated with an increase of bone marrow fat resulting from accumulation of adipocytes within the bone marrow. Marrow adipocytes are active secretory cells, releasing cytokines, adipokines and free fatty acids (FA) that influence the bone marrow microenvironment and alter the biology of neighboring cells. Therefore, we examined the effect of palmitate (Palm) and oleate (Ole), 2 highly prevalent FA in human organism and diet, on the function and survival of human mesenchymal stem cells (MSC) and MSC-derived osteoblastic cells. The saturated FA Palm exerted a cytotoxic action via initiation of endoplasmic reticulum stress and activation of the nuclear factor κB (NF-κB) and ERK pathways. In addition, Palm induced a proinflammatory response, as determined by the up-regulation of Toll-like receptor 4 expression as well as the increase of IL-6 and IL-8 expression and secretion. Moreover, we showed that MSC-derived osteoblastic cells were more sensitive to lipotoxicity than undifferentiated MSC. The monounsaturated FA Ole fully neutralized Palm-induced lipotoxicity by impairing activation of the pathways triggered by the saturated FA. Moreover, Ole promoted Palm detoxification by fostering its esterification into triglycerides and storage in lipid droplets. Altogether, our data showed that physiological concentrations of Palm and Ole differently modulated cell death and function in bone cells. We therefore propose that FA could influence skeletal health.
Collapse
Affiliation(s)
- C Gillet
- Laboratory of Bone and Metabolic Biochemistry (C.G., D.S., S.R., A.D.V., J.B., N.G., W.J.M., V.G., J.R.), Faculty of Medicine, Université libre de Bruxelles, B-1070 Brussels, Belgium; Institute of Life Sciences (C.L., C.D.), Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium; and Department of Rheumatology and Physical Medicine (V.G.), Erasme Hospital, B-1070 Brussels, Belgium
| | - D Spruyt
- Laboratory of Bone and Metabolic Biochemistry (C.G., D.S., S.R., A.D.V., J.B., N.G., W.J.M., V.G., J.R.), Faculty of Medicine, Université libre de Bruxelles, B-1070 Brussels, Belgium; Institute of Life Sciences (C.L., C.D.), Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium; and Department of Rheumatology and Physical Medicine (V.G.), Erasme Hospital, B-1070 Brussels, Belgium
| | - S Rigutto
- Laboratory of Bone and Metabolic Biochemistry (C.G., D.S., S.R., A.D.V., J.B., N.G., W.J.M., V.G., J.R.), Faculty of Medicine, Université libre de Bruxelles, B-1070 Brussels, Belgium; Institute of Life Sciences (C.L., C.D.), Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium; and Department of Rheumatology and Physical Medicine (V.G.), Erasme Hospital, B-1070 Brussels, Belgium
| | - A Dalla Valle
- Laboratory of Bone and Metabolic Biochemistry (C.G., D.S., S.R., A.D.V., J.B., N.G., W.J.M., V.G., J.R.), Faculty of Medicine, Université libre de Bruxelles, B-1070 Brussels, Belgium; Institute of Life Sciences (C.L., C.D.), Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium; and Department of Rheumatology and Physical Medicine (V.G.), Erasme Hospital, B-1070 Brussels, Belgium
| | - J Berlier
- Laboratory of Bone and Metabolic Biochemistry (C.G., D.S., S.R., A.D.V., J.B., N.G., W.J.M., V.G., J.R.), Faculty of Medicine, Université libre de Bruxelles, B-1070 Brussels, Belgium; Institute of Life Sciences (C.L., C.D.), Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium; and Department of Rheumatology and Physical Medicine (V.G.), Erasme Hospital, B-1070 Brussels, Belgium
| | - C Louis
- Laboratory of Bone and Metabolic Biochemistry (C.G., D.S., S.R., A.D.V., J.B., N.G., W.J.M., V.G., J.R.), Faculty of Medicine, Université libre de Bruxelles, B-1070 Brussels, Belgium; Institute of Life Sciences (C.L., C.D.), Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium; and Department of Rheumatology and Physical Medicine (V.G.), Erasme Hospital, B-1070 Brussels, Belgium
| | - C Debier
- Laboratory of Bone and Metabolic Biochemistry (C.G., D.S., S.R., A.D.V., J.B., N.G., W.J.M., V.G., J.R.), Faculty of Medicine, Université libre de Bruxelles, B-1070 Brussels, Belgium; Institute of Life Sciences (C.L., C.D.), Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium; and Department of Rheumatology and Physical Medicine (V.G.), Erasme Hospital, B-1070 Brussels, Belgium
| | - N Gaspard
- Laboratory of Bone and Metabolic Biochemistry (C.G., D.S., S.R., A.D.V., J.B., N.G., W.J.M., V.G., J.R.), Faculty of Medicine, Université libre de Bruxelles, B-1070 Brussels, Belgium; Institute of Life Sciences (C.L., C.D.), Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium; and Department of Rheumatology and Physical Medicine (V.G.), Erasme Hospital, B-1070 Brussels, Belgium
| | - W J Malaisse
- Laboratory of Bone and Metabolic Biochemistry (C.G., D.S., S.R., A.D.V., J.B., N.G., W.J.M., V.G., J.R.), Faculty of Medicine, Université libre de Bruxelles, B-1070 Brussels, Belgium; Institute of Life Sciences (C.L., C.D.), Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium; and Department of Rheumatology and Physical Medicine (V.G.), Erasme Hospital, B-1070 Brussels, Belgium
| | - V Gangji
- Laboratory of Bone and Metabolic Biochemistry (C.G., D.S., S.R., A.D.V., J.B., N.G., W.J.M., V.G., J.R.), Faculty of Medicine, Université libre de Bruxelles, B-1070 Brussels, Belgium; Institute of Life Sciences (C.L., C.D.), Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium; and Department of Rheumatology and Physical Medicine (V.G.), Erasme Hospital, B-1070 Brussels, Belgium
| | - J Rasschaert
- Laboratory of Bone and Metabolic Biochemistry (C.G., D.S., S.R., A.D.V., J.B., N.G., W.J.M., V.G., J.R.), Faculty of Medicine, Université libre de Bruxelles, B-1070 Brussels, Belgium; Institute of Life Sciences (C.L., C.D.), Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium; and Department of Rheumatology and Physical Medicine (V.G.), Erasme Hospital, B-1070 Brussels, Belgium
| |
Collapse
|
72
|
Scheller EL, Doucette CR, Learman BS, Cawthorn WP, Khandaker S, Schell B, Wu B, Ding SY, Bredella MA, Fazeli PK, Khoury B, Jepsen KJ, Pilch PF, Klibanski A, Rosen CJ, MacDougald OA. Region-specific variation in the properties of skeletal adipocytes reveals regulated and constitutive marrow adipose tissues. Nat Commun 2015; 6:7808. [PMID: 26245716 PMCID: PMC4530473 DOI: 10.1038/ncomms8808] [Citation(s) in RCA: 290] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 06/12/2015] [Indexed: 12/22/2022] Open
Abstract
Marrow adipose tissue (MAT) accumulates in diverse clinical conditions but remains poorly understood. Here we show region-specific variation in MAT adipocyte development, regulation, size, lipid composition, gene expression and genetic determinants. Early MAT formation in mice is conserved, whereas later development is strain dependent. Proximal, but not distal tibial, MAT is lost with 21-day cold exposure. Rat MAT adipocytes from distal sites have an increased proportion of monounsaturated fatty acids and expression of Scd1/Scd2, Cebpa and Cebpb. Humans also have increased distal marrow fat unsaturation. We define proximal 'regulated' MAT (rMAT) as single adipocytes interspersed with active haematopoiesis, whereas distal 'constitutive' MAT (cMAT) has low haematopoiesis, contains larger adipocytes, develops earlier and remains preserved upon systemic challenges. Loss of rMAT occurs in mice with congenital generalized lipodystrophy type 4, whereas both rMAT and cMAT are preserved in mice with congenital generalized lipodystrophy type 3. Consideration of these MAT subpopulations may be important for future studies linking MAT to bone biology, haematopoiesis and whole-body metabolism.
Collapse
Affiliation(s)
- Erica L Scheller
- Departments of Molecular and Integrative Physiology and Internal Medicine, University of Michigan, Ann Arbor, Michigan 48105, USA
| | - Casey R Doucette
- Center for Clinical and Translational Research, Maine Medical Center Research Institute, Scarborough, Maine 04074, USA
| | - Brian S Learman
- Departments of Molecular and Integrative Physiology and Internal Medicine, University of Michigan, Ann Arbor, Michigan 48105, USA
| | - William P Cawthorn
- Departments of Molecular and Integrative Physiology and Internal Medicine, University of Michigan, Ann Arbor, Michigan 48105, USA
| | - Shaima Khandaker
- Departments of Molecular and Integrative Physiology and Internal Medicine, University of Michigan, Ann Arbor, Michigan 48105, USA
| | - Benjamin Schell
- Departments of Molecular and Integrative Physiology and Internal Medicine, University of Michigan, Ann Arbor, Michigan 48105, USA
| | - Brent Wu
- Departments of Molecular and Integrative Physiology and Internal Medicine, University of Michigan, Ann Arbor, Michigan 48105, USA
| | - Shi-Ying Ding
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Miriam A Bredella
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Pouneh K Fazeli
- Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Basma Khoury
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Karl J Jepsen
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Paul F Pilch
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Anne Klibanski
- Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Clifford J Rosen
- Center for Clinical and Translational Research, Maine Medical Center Research Institute, Scarborough, Maine 04074, USA
| | - Ormond A MacDougald
- Departments of Molecular and Integrative Physiology and Internal Medicine, University of Michigan, Ann Arbor, Michigan 48105, USA
| |
Collapse
|
73
|
Yeh LCC, Wilkerson M, Lee JC, Adamo ML. IGF-1 Receptor Insufficiency Leads to Age-Dependent Attenuation of Osteoblast Differentiation. Endocrinology 2015; 156:2872-9. [PMID: 26076041 PMCID: PMC4511128 DOI: 10.1210/en.2014-1945] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In the current study, we determined the effects of IGF-1 receptor haploinsufficiency on osteoblast differentiation and bone formation throughout the lifespan. Bone mineral density was significantly decreased in femurs of male and female Igf1r(+/-) mice compared with wild-type mice. mRNA expression of osteoblast differentiation markers was significantly decreased in femurs and calvariae from Igf1r(+/-) mice compared with cells from wild-type mice. Bone morphogenetic protein-7-induced ectopic bone in Igf1r(+/-) mice was significantly smaller with fewer osteoblasts but more lipid droplets and had reduced expression of osteoblast differentiation markers compared with wild-type mice. In bone marrow cells from middle-aged and old wild-type and Igf1r(+/-) male mice, palmitate inhibited osteoblast markers expression. In cells from young wild-type male mice, palmitate did not inhibit marker expression, but in cells from young male Igf1r(+/-) mice, palmitate inhibited bone sialoprotein and osterix but not osteocalcin or type I collagen (TIC). In female wild-type mice, palmitate inhibited osteoblast markers expression in cells from young, middle-aged, and old mice except TIC in cells from middle-aged mice. Palmitate inhibited bone sialoprotein expression in cells from middle-aged and old female Igf1r(+/-) mice and osteocalcin, osterix, and TIC expression in young and middle-aged female Igf1r(+/-) mice but stimulated expression in cells from old female Igf1r(+/-) mice. We conclude that IGF-1 receptor haploinsufficiency results in a prolipid accrual phenotype in bone in association with inhibition of growth factor-induced osteoblast differentiation, a situation which may phenocopy age-related decreases in bone formation.
Collapse
Affiliation(s)
- Lee-Chuan C Yeh
- Department of Biochemistry (L.-C.C.Y., M.W., J.C.L., M.L.A.) and The Sam and Ann Barshop Institute for Longevity and Aging Studies (J.C.L., M.L.A.), The University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3900
| | - Matthew Wilkerson
- Department of Biochemistry (L.-C.C.Y., M.W., J.C.L., M.L.A.) and The Sam and Ann Barshop Institute for Longevity and Aging Studies (J.C.L., M.L.A.), The University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3900
| | - John C Lee
- Department of Biochemistry (L.-C.C.Y., M.W., J.C.L., M.L.A.) and The Sam and Ann Barshop Institute for Longevity and Aging Studies (J.C.L., M.L.A.), The University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3900
| | - Martin L Adamo
- Department of Biochemistry (L.-C.C.Y., M.W., J.C.L., M.L.A.) and The Sam and Ann Barshop Institute for Longevity and Aging Studies (J.C.L., M.L.A.), The University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3900
| |
Collapse
|
74
|
Lecka-Czernik B, Stechschulte LA, Czernik PJ, Dowling AR. High bone mass in adult mice with diet-induced obesity results from a combination of initial increase in bone mass followed by attenuation in bone formation; implications for high bone mass and decreased bone quality in obesity. Mol Cell Endocrinol 2015; 410:35-41. [PMID: 25576855 DOI: 10.1016/j.mce.2015.01.001] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 12/23/2014] [Accepted: 01/02/2015] [Indexed: 11/22/2022]
Abstract
Obesity is generally recognized as a condition which positively influences bone mass and bone mineral density (BMD). Positive effect of high body mass index (BMI) on bone has been recognized as a result of increased mechanical loading exerted on the skeleton. However, epidemiologic studies indicate that obesity is associated with increased incidence of fractures. The results presented here offer a new perspective regarding the mechanisms which may be responsible for the increase of bone mass and concurrent decrease in bone quality. Two groups of 12 week old C57BL/6 males were fed either high fat diet (HFD) or regular diet (RD) for 11 weeks. Metabolic profile, bone parameters and gene expression were assessed in these groups at the end of the experiment. Additionally, bone status was evaluated in a third group of 12 week old animals corresponding to animals at the start of the feeding period. Administration of HFD resulted in development of a diet-induced obesity (DIO), glucose intolerance, alteration in energy metabolism, and impairment in WAT function, as compared to the age-matched control animals fed RD. The expression of adiponectin, FABP4/aP2, DIO2 and FoxC2 were decreased in WAT of DIO animals, as well as transcript levels for IGFBP2, the cytokine regulating both energy metabolism and bone mass. At the end of experiment, DIO mice had higher bone mass than both control groups on RD, however they had decreased bone formation, as assessed by calcein labeling, and increased marrow adipocyte content. This study suggests that the bone mass acquired in obesity is a result of a two-phase process. First phase would consist of either beneficial effect of fat expansion to increase bone mass by increased mechanical loading and/or increased production of bone anabolic adipokines and/or nutritional effect of fatty acids. This is followed by a second phase characterized by decreased bone formation and bone turnover resulting from development of metabolic impairment.
Collapse
Affiliation(s)
- B Lecka-Czernik
- Department of Orthopaedic Surgery, University of Toledo Health Sciences Campus, 3000 Arlington Avenue, Toledo, OH 43614, USA; Department of Physiology and Pharmacology, University of Toledo Health Sciences Campus, 3000 Arlington Avenue, Toledo, OH 43614, USA; Center for Diabetes and Endocrine Research (CeDER), University of Toledo Health Sciences Campus, 3000 Arlington Avenue, Toledo, OH 43614, USA.
| | - L A Stechschulte
- Department of Orthopaedic Surgery, University of Toledo Health Sciences Campus, 3000 Arlington Avenue, Toledo, OH 43614, USA; Center for Diabetes and Endocrine Research (CeDER), University of Toledo Health Sciences Campus, 3000 Arlington Avenue, Toledo, OH 43614, USA
| | - P J Czernik
- Department of Orthopaedic Surgery, University of Toledo Health Sciences Campus, 3000 Arlington Avenue, Toledo, OH 43614, USA
| | - A R Dowling
- Department of Physiology and Pharmacology, University of Toledo Health Sciences Campus, 3000 Arlington Avenue, Toledo, OH 43614, USA
| |
Collapse
|
75
|
Vimalraj S, Arumugam B, Miranda P, Selvamurugan N. Runx2: Structure, function, and phosphorylation in osteoblast differentiation. Int J Biol Macromol 2015; 78:202-8. [DOI: 10.1016/j.ijbiomac.2015.04.008] [Citation(s) in RCA: 236] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 04/02/2015] [Accepted: 04/03/2015] [Indexed: 02/07/2023]
|
76
|
Wang S, Song K, Srivastava R, Dong C, Go GW, Li N, Iwakiri Y, Mani A. Nonalcoholic fatty liver disease induced by noncanonical Wnt and its rescue by Wnt3a. FASEB J 2015; 29:3436-45. [PMID: 25917329 DOI: 10.1096/fj.15-271171] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 04/16/2015] [Indexed: 12/17/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease, which begins with isolated steatosis and advances to nonalcoholic steatohepatitis (NASH), steatofibrosis, and cirrhosis. The pathways involved in disease progression are not understood. Loss-of-function mutations in Wnt coreceptor LDL receptor-related protein 6 (LRP6) underlie early-onset atherosclerosis, metabolic risk factors, and NAFLD in humans by unknown mechanisms. We generated mice with the human disease-associated LRP6(R611C) mutation and phenotypically characterized their liver. Homozygote LRP6(R611C) (LRP6(mut/mut)) mice exhibited both steatohepatitis and steatofibrosis. These traits were associated with increased activity of the noncanonical Wnt/Ras homolog family member A, Rho-associated protein kinase 2, and PKC-α/-μ pathways. Accordingly, there was increased TGF-β1 activity, coupled with enhanced expression of smooth muscle α-actin and vimentin that colocalized with albumin in LRP6(mut/mut) mouse liver. LRP6 knockdown reprogramed HepG2 cells to express both these markers, linking impaired Wnt signaling with hepatocyte transdifferentiation. The causal link between altered Wnt signaling and NASH was established by normalization of the disease pathways and rescue of the liver traits by Wnt3a administration to LRP6(mut/mut) mice. Thus, this study identifies diverse disease pathways that underlie a spectrum of NASH-related liver diseases and are linked by a single human genetic variant. LRP6 and noncanonical Wnt pathways are important potential therapeutic targets against NASH.
Collapse
Affiliation(s)
- Shuxia Wang
- *Yale Cardiovascular Research Center, Department of Internal Medicine, Yale Liver Center, and Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Geriatric Cardiology and The Cardiology Department, Chinese Peoples' Liberation Army General Hospital & Medical School, Beijing, China; and Department of Food and Nutrition, Kookmin University, Seoul, South Korea
| | - Kangxing Song
- *Yale Cardiovascular Research Center, Department of Internal Medicine, Yale Liver Center, and Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Geriatric Cardiology and The Cardiology Department, Chinese Peoples' Liberation Army General Hospital & Medical School, Beijing, China; and Department of Food and Nutrition, Kookmin University, Seoul, South Korea
| | - Roshni Srivastava
- *Yale Cardiovascular Research Center, Department of Internal Medicine, Yale Liver Center, and Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Geriatric Cardiology and The Cardiology Department, Chinese Peoples' Liberation Army General Hospital & Medical School, Beijing, China; and Department of Food and Nutrition, Kookmin University, Seoul, South Korea
| | - Chao Dong
- *Yale Cardiovascular Research Center, Department of Internal Medicine, Yale Liver Center, and Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Geriatric Cardiology and The Cardiology Department, Chinese Peoples' Liberation Army General Hospital & Medical School, Beijing, China; and Department of Food and Nutrition, Kookmin University, Seoul, South Korea
| | - Gwang-Woong Go
- *Yale Cardiovascular Research Center, Department of Internal Medicine, Yale Liver Center, and Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Geriatric Cardiology and The Cardiology Department, Chinese Peoples' Liberation Army General Hospital & Medical School, Beijing, China; and Department of Food and Nutrition, Kookmin University, Seoul, South Korea
| | - Na Li
- *Yale Cardiovascular Research Center, Department of Internal Medicine, Yale Liver Center, and Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Geriatric Cardiology and The Cardiology Department, Chinese Peoples' Liberation Army General Hospital & Medical School, Beijing, China; and Department of Food and Nutrition, Kookmin University, Seoul, South Korea
| | - Yasuko Iwakiri
- *Yale Cardiovascular Research Center, Department of Internal Medicine, Yale Liver Center, and Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Geriatric Cardiology and The Cardiology Department, Chinese Peoples' Liberation Army General Hospital & Medical School, Beijing, China; and Department of Food and Nutrition, Kookmin University, Seoul, South Korea
| | - Arya Mani
- *Yale Cardiovascular Research Center, Department of Internal Medicine, Yale Liver Center, and Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Geriatric Cardiology and The Cardiology Department, Chinese Peoples' Liberation Army General Hospital & Medical School, Beijing, China; and Department of Food and Nutrition, Kookmin University, Seoul, South Korea
| |
Collapse
|
77
|
Li GW, Xu Z, Chang SX, Zhou L, Wang XY, Nian H, Shi X. Influence of early zoledronic acid administration on bone marrow fat in ovariectomized rats. Endocrinology 2014; 155:4731-8. [PMID: 25243855 DOI: 10.1210/en.2014-1359] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Although the primary target cell of bisphosphonates is the osteoclast, increasing attention is being given to other effector cells influenced by bisphosphonates, such as osteoblasts and marrow adipocytes. Early zoledronic acid (ZA) treatment to ovariectomized (OVX) rats has been found to fully preserve bone microarchitecture over time. However, little is known regarding the influence of ZA on marrow adipogenesis. The purpose of this study was to monitor the ability of early administration of ZA in restoring marrow adiposity in an estrogen-deficient rat model. Thirty female Sprague-Dawley rats were randomly divided into sham-operated (SHAM), OVX + vehicle, and OVX + ZA groups (n=10/group). Dual-energy x-ray absorptiometry and water/fat magnetic resonance imaging were performed at baseline, 6 weeks, and 12 weeks after treatment to assess bone mineral density and marrow fat fraction. Serum biochemical markers, bone remodeling, and marrow adipocyte parameters were analyzed using biochemistry, histomorphometry, and histopathology, respectively. The expression levels of osteoblast, adipocyte, and osteoclast-related genes in bone marrow were assessed using RT-PCR. The OVX rats showed marked bone loss, first detected at 12 weeks, but estrogen deficiency resulted in a remarked increase in marrow fat fraction, first detected at 6 weeks compared with the SHAM rats (all P < .001). Similarly, the OVX rats had a substantially larger percent adipocyte area (+163.0%), mean diameter (+29.5%), and higher density (+57.3%) relative to the SHAM rats. Bone histomorphometry, levels of osteoclast-related gene expression, and a serum resorption marker confirmed that ZA significantly suppressed bone resorption activities. Furthermore, ZA treatment returned adipocyte-related gene expression and marrow adipocyte parameters toward SHAM levels. These data suggest that a single dose of early ZA treatment acts to reverse marrow adipogenesis occurring during estrogen deficiency, which may contribute to its capacity to reduce bone loss.
Collapse
Affiliation(s)
- Guan-Wu Li
- Departments of Radiology (G.-W.L., S.-X.C., L.Z., X.-Y.W.), Pharmacy (H.N.), and Gerontology (X.S.), Yueyang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China; and Medico-Technical Department (Z.X.), Xin-Zhuang Community Health Service Center, Shanghai 201199, China
| | | | | | | | | | | | | |
Collapse
|
78
|
Yeh LCC, Ford JJ, Lee JC, Adamo ML. Palmitate attenuates osteoblast differentiation of fetal rat calvarial cells. Biochem Biophys Res Commun 2014; 450:777-81. [PMID: 24955854 DOI: 10.1016/j.bbrc.2014.06.063] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 06/12/2014] [Indexed: 10/25/2022]
Abstract
Aging is associated with the accumulation of ectopic lipid resulting in the inhibition of normal organ function, a phenomenon known as lipotoxicity. Within the bone marrow microenvironment, elevation in fatty acid levels may produce an increase in osteoclast activity and a decrease in osteoblast number and function, thus contributing to age-related osteoporosis. However, little is known about lipotoxic mechanisms in intramembraneous bone. Previously we reported that the long chain saturated fatty acid palmitate inhibited the expression of the osteogenic markers RUNX2 and osteocalcin in fetal rat calvarial cell (FRC) cultures. Moreover, the acetyl CoA carboxylase inhibitor TOFA blocked the inhibitory effect of palmitate on expression of these two markers. In the current study we have extended these observations to show that palmitate inhibits spontaneous mineralized bone formation in FRC cultures in association with reduced mRNA expression of RUNX2, alkaline phosphatase, osteocalcin, and bone sialoprotein and reduced alkaline phosphatase activity. The effects of palmitate on osteogenic marker expression were inhibited by TOFA. Palmitate also inhibited the mRNA expression of fatty acid synthase and PPARγ in FRC cultures, and as with osteogenic markers, this effect was inhibited by TOFA. Palmitate had no effect on FRC cell proliferation or apoptosis, but inhibited BMP-7-induced alkaline phosphatase activity. We conclude that palmitate accumulation may lead to lipotoxic effects on osteoblast differentiation and mineralization and that increases in fatty acid oxidation may help to prevent these lipotoxic effects.
Collapse
Affiliation(s)
- Lee-Chuan C Yeh
- Department of Biochemistry, The University of Texas Health Science Center at San Antonio, TX, United States
| | - Jeffery J Ford
- Department of Biochemistry, The University of Texas Health Science Center at San Antonio, TX, United States
| | - John C Lee
- Department of Biochemistry, The University of Texas Health Science Center at San Antonio, TX, United States; The Sam and Ann Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, TX, United States
| | - Martin L Adamo
- Department of Biochemistry, The University of Texas Health Science Center at San Antonio, TX, United States; The Sam and Ann Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, TX, United States.
| |
Collapse
|
79
|
Abstract
Fat and bone have a complicated relationship. Although obesity has been associated with low fracture risk, there is increasing evidence that some of the factors that are released by peripheral fat into the circulation may also have a deleterious effect on bone mass, thus, predisposing to fractures. More importantly, the local interaction between fat and bone within the bone marrow seems to play a significant role in the pathogenesis of age-related bone loss and osteoporosis. This "local interaction" occurs inside the bone marrow and is associated with the autocrine and paracrine release of fatty acids and adipokines, which affect the cells in their vicinity including the osteoblasts, reducing their function and survival. In this review, we explore the particularities of the fat and bone cell interactions within the bone marrow, their significance in the pathogenesis of osteoporosis, and the potential therapeutic applications that regulating marrow fat may have in the near future as a novel pharmacologic treatment for osteoporosis.
Collapse
Affiliation(s)
- Sandra Bermeo
- Ageing Bone Research Program, Sydney Medical School Nepean, The University of Sydney, Level 5, South Block, Nepean Hospital, Penrith, NSW., Australia, 2750
| | | | | |
Collapse
|