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Xie L, Cheng Y, Hu B, Chen X, An Y, Xia Z, Cai G, Li C, Peng H. PCLAF induces bone marrow adipocyte senescence and contributes to skeletal aging. Bone Res 2024; 12:38. [PMID: 38961077 PMCID: PMC11222446 DOI: 10.1038/s41413-024-00337-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 03/30/2024] [Accepted: 04/11/2024] [Indexed: 07/05/2024] Open
Abstract
Bone marrow adipocytes (BMAds) affect bone homeostasis, but the mechanism remains unclear. Here, we showed that exercise inhibited PCNA clamp-associated factor (PCLAF) secretion from the bone marrow macrophages to inhibit BMAds senescence and thus alleviated skeletal aging. The genetic deletion of PCLAF in macrophages inhibited BMAds senescence and delayed skeletal aging. In contrast, the transplantation of PCLAF-mediated senescent BMAds into the bone marrow of healthy mice suppressed bone turnover. Mechanistically, PCLAF bound to the ADGRL2 receptor to inhibit AKT/mTOR signaling that triggered BMAds senescence and subsequently spread senescence among osteogenic and osteoclastic cells. Of note, we developed a PCLAF-neutralizing antibody and showed its therapeutic effects on skeletal health in old mice. Together, these findings identify PCLAF as an inducer of BMAds senescence and provide a promising way to treat age-related osteoporosis.
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Affiliation(s)
- Lingqi Xie
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, 410008, China
| | - Yalun Cheng
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, 410008, China
| | - Biao Hu
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, 410008, China
| | - Xin Chen
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, 410008, China
| | - Yuze An
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, 410008, China
| | - Zhuying Xia
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, 410008, China
| | - Guangping Cai
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, 410008, China
| | - Changjun Li
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, Hunan, 410008, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, Hunan, 410008, China
| | - Hui Peng
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, 410008, China.
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Zhou M, An YZ, Guo Q, Zhou HY, Luo XH. Energy homeostasis in the bone. Trends Endocrinol Metab 2024; 35:439-451. [PMID: 38242815 DOI: 10.1016/j.tem.2023.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 12/19/2023] [Accepted: 12/21/2023] [Indexed: 01/21/2024]
Abstract
The bone serves as an energy reservoir and actively engages in whole-body energy metabolism. Numerous studies have determined fuel requirements and bioenergetic properties of bone under physiological conditions as well as the dysregulation of energy metabolism associated with bone metabolic diseases. Here, we review the main sources of energy in bone cells and their regulation, as well as the endocrine role of the bone in systemic energy homeostasis. Moreover, we discuss metabolic changes that occur as a result of osteoporosis. Exploration in this area will contribute to an enhanced comprehension of bone energy metabolism, presenting novel possibilities to address metabolic diseases.
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Affiliation(s)
- Min Zhou
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, PR China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, Hunan 410008, PR China; Key Laboratory of Aging-Related Bone and Joint Diseases Prevention and Treatment, Ministry of Education, Xiangya Hospital, Central South University, Changsha, PR China; Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Hunan 410008, PR China
| | - Yu-Ze An
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, PR China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, Hunan 410008, PR China; Key Laboratory of Aging-Related Bone and Joint Diseases Prevention and Treatment, Ministry of Education, Xiangya Hospital, Central South University, Changsha, PR China; Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Hunan 410008, PR China
| | - Qi Guo
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, PR China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, Hunan 410008, PR China; Key Laboratory of Aging-Related Bone and Joint Diseases Prevention and Treatment, Ministry of Education, Xiangya Hospital, Central South University, Changsha, PR China; Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Hunan 410008, PR China
| | - Hai-Yan Zhou
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, PR China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, Hunan 410008, PR China; Key Laboratory of Aging-Related Bone and Joint Diseases Prevention and Treatment, Ministry of Education, Xiangya Hospital, Central South University, Changsha, PR China; Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Hunan 410008, PR China.
| | - Xiang-Hang Luo
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan 410008, PR China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, Hunan 410008, PR China; Key Laboratory of Aging-Related Bone and Joint Diseases Prevention and Treatment, Ministry of Education, Xiangya Hospital, Central South University, Changsha, PR China; Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Hunan 410008, PR China.
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Niu Z, Zhou Y, Liang M, Su F, Guo Q, Jing J, Xie J, Zhang D, Liu X. Crosstalk between ALK3(BMPR1A) deficiency and autophagy signaling mitigates pathological bone loss in osteoporosis. Bone 2024; 182:117052. [PMID: 38408588 DOI: 10.1016/j.bone.2024.117052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 02/08/2024] [Accepted: 02/18/2024] [Indexed: 02/28/2024]
Abstract
Postmenopausal osteoporosis is recognized to be one of the major skeleton diseases strongly associated with impaired bone formation. Previous reports have indicated that the importance of bone morphogenetic protein (BMP) signaling of osteoblast lineage in bone development via classical Smad signaling, however, its critical role in osteoporosis is still not well understood. In the current study, we aim to investigate the pathological role of BMPR1A, a key receptor of BMPs, in osteoporosis and its underlying mechanism. We first found that knockdown of BMPR1A by using Col1a1-creER in osteoblasts mitigated early bone loss of osteoporosis in mice, yet along with late bone maturation defects by reducing mineral adherence rate and bone formation rate in vivo. At the cellular level, we then observed that BMPR1A deficiency promoted the proliferation of pre-osteoblasts under osteoporotic conditions but hindered their late-stage mineralization. We finally elucidated that BMPR1A deficiency compensatorily triggered mTOR-autophagy perturbation by a higher level in early osteoporotic pre-osteoblasts thus resulting in the enhancement of transient cell proliferation but impairment of final mineralization. Taken together, this study indicated the significance of BMPR1A-mTOR/autophagy axis, as a double-edged sword, in osteoporotic bone formation and provided new cues for therapeutic strategies in osteoporosis.
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Affiliation(s)
- Zhixing Niu
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Yumeng Zhou
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China; Institute of Biomedical Engineering, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Sichuan, China
| | - Muchun Liang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China; Institute of Biomedical Engineering, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Sichuan, China
| | - Fuqiang Su
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China; Institute of Biomedical Engineering, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Sichuan, China
| | - Qiang Guo
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Junjun Jing
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Jing Xie
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China.
| | - Demao Zhang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China; Institute of Biomedical Engineering, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Sichuan, China.
| | - Xiaoheng Liu
- Institute of Biomedical Engineering, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Sichuan, China
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Bermudez B, Brown KC, Vahidi G, Ferreira Ruble AC, Heveran CM, Ackert-Bicknell CL, Sherk VD. Sex-specific effects of Fat-1 transgene on bone material properties, size, and shape in mice. JBMR Plus 2024; 8:ziad011. [PMID: 38523667 PMCID: PMC10958611 DOI: 10.1093/jbmrpl/ziad011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 10/20/2024] [Accepted: 11/10/2024] [Indexed: 03/26/2024] Open
Abstract
Western diets are becoming increasingly common around the world. Western diets have high omega 6 (ω-6) and omega 3 (ω-3) fatty acids and are linked to bone loss in humans and animals. Dietary fats are not created equal; therefore, it is vital to understand the effects of specific dietary fats on bone. We aimed to determine how altering the endogenous ratios of ω-6:ω-3 fatty acids impacts bone accrual, strength, and fracture toughness. To accomplish this, we used the Fat-1 transgenic mice, which carry a gene responsible for encoding a ω-3 fatty acid desaturase that converts ω-6 to ω-3 fatty acids. Male and female Fat-1 positive mice (Fat-1) and Fat-1 negative littermates (WT) were given either a high-fat diet (HFD) or low-fat diet (LFD) at 4 wk of age for 16 wk. The Fat-1 transgene reduced fracture toughness in males. Additionally, male BMD, measured from DXA, decreased over the diet duration for HFD mice. In males, neither HFD feeding nor the presence of the Fat-1 transgene impacted cortical geometry, trabecular architecture, or whole-bone flexural properties, as detected by main group effects. In females, Fat-1-LFD mice experienced increases in BMD compared to WT-LFD mice; however, cortical area, distal femur trabecular thickness, and cortical stiffness were reduced in Fat-1 mice compared to pooled WT controls. However, reductions in stiffness were caused by a decrease in bone size and were not driven by changes in material properties. Together, these results demonstrate that the endogenous ω-6:ω-3 fatty acid ratio influences bone material properties in a sex-dependent manner. In addition, Fat-1 mediated fatty acid conversion was not able to mitigate the adverse effects of HFD on bone strength and accrual.
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Affiliation(s)
- Beatriz Bermudez
- Department of Mechanical Engineering, University of Colorado Denver, Denver, CO 80204, United States
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States
| | - Kenna C Brown
- Department of Mechanical Engineering, Montana State University, Bozeman, MT 59717, United States
| | - Ghazal Vahidi
- Department of Mechanical Engineering, Montana State University, Bozeman, MT 59717, United States
| | - Ana C Ferreira Ruble
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States
| | - Chelsea M Heveran
- Department of Mechanical Engineering, Montana State University, Bozeman, MT 59717, United States
| | - Cheryl L Ackert-Bicknell
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States
| | - Vanessa D Sherk
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, United States
- Center for Scientific Review, National Institutes of Health, Bethesda, MD 20892, United States
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Cheng L, Xu Y, Long Y, Yu F, Gui L, Zhang Q, Lu Y. Liraglutide attenuates palmitate-induced apoptosis via PKA/β-catenin/Bcl-2/Bax pathway in MC3T3-E1 cells. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024; 397:329-341. [PMID: 37439807 DOI: 10.1007/s00210-023-02572-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 06/09/2023] [Indexed: 07/14/2023]
Abstract
Liraglutide (LRG), one agonist of glucagon-like peptide-1 receptor (GLP1R), has multiple lipid-lowering effects in type 2 diabetes mellitus, however, studies on the role of LRG in saturated fatty acid-induced bone loss are limited. Therefore, our aim was to investigate whether LRG reduces palmitate (PA)-induced apoptosis and whether the mechanism involves PKA/β-catenin/Bcl-2/Bax in osteoblastic MC3T3-E1 cells. MC3T3-E1 cells were treated with different concentrations of PA, LRG, or pretreated with Exendin 9-39 and H89, cell viability, intracellular reactive oxygen species (ROS), cAMP levels, apoptosis and the expression of protein kinase A (PKA) and phosphorylation of PKA (p-PKA), β-catenin and phosphorylation of β-catenin (Ser675)(p-β-catenin), GLP1R, cleaved-capase 3, Bcl2-Associated X Protein (Bax) and B-cell lymphoma-2 (Bcl-2) along with expression of Osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) were evaluated. PA treatment inhibited cell proliferation and cAMP levels, elevated intracellular ROS levels and promoted apoptosis, increased protein expressions of RANKL, Bax and cleaved-caspase3, meanwhile decreased protein expression of OPG and Bcl-2 in a dose-dependent manner. LRG inverted PA-induced apoptosis, increased cAMP levels, promoted expression of p-PKA, p-β-catenin (Ser675) and reversed these gene expressions via increasing GLP1R expression. Pretreatment of the cells with Exendin 9-39 and H89 partially eradicated the protective effect of LRG on PA-induced apoptosis and gene expressions. Therefore, these findings indicated that LRG attenuates PA-induced apoptosis possibly by GLP1R-mediated PKA/β-catenin/Bcl-2/Bax pathway in MC3T3-E1 cells. Our results point to LRG as a new strategy to attenuate bone loss associated with high fat diet beyond its lipid-lowering actions. LRG inhibits PA-mediated apoptosis via GLP1R-mediated PKA/β-catenin/Bcl-2/ Bax pathway, while possibly enhances PA-inhibited differentiation by regulating the expression of OPG and RANKL.
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Affiliation(s)
- Lanlan Cheng
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Yijing Xu
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Yueming Long
- Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Anhui Medical University, Hefei, China
| | - Fangmei Yu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Anhui Medical University, Hefei, China
| | - Li Gui
- The Comprehensive Laboratory, School of Basic Medical Science, Anhui Medical University, Hefei, China
| | - Qiu Zhang
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Anhui Medical University, Hefei, China.
| | - Yunxia Lu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Anhui Medical University, Hefei, China.
- The Comprehensive Laboratory, School of Basic Medical Science, Anhui Medical University, Hefei, China.
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Li Z, Rosen CJ. The Multifaceted Roles of Bone Marrow Adipocytes in Bone and Hematopoietic Homeostasis. J Clin Endocrinol Metab 2023; 108:e1465-e1472. [PMID: 37315208 DOI: 10.1210/clinem/dgad355] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 06/07/2023] [Accepted: 06/09/2023] [Indexed: 06/16/2023]
Abstract
Bone marrow adipose tissue (BMAT) makes up a significant portion of the marrow space, ranging from 50% to 70%, in healthy adults. It expands with aging, obesity, anorexia nervosa, and irradiation, which are conditions associated with skeletal complications or hematopoietic disorders. Therefore, BMAT has been viewed as a negative component of the bone marrow niche for decades, although the mechanisms and causative relationships have not been well-addressed. Of note, recent studies have revealed that BMAT is a multifaceted tissue that can serve as an energy reservoir to fuel osteoblasts and hematopoietic cells under stressful situations, and also acts as an endocrine/paracrine organ to suppress bone formation and support hematopoiesis at steady-state conditions. In this review, we summarize the uniqueness of BMAT, the complex findings of previous studies, and update our understanding of the physiological roles of BMAT in bone and hematopoietic metabolism based on a newly established bone marrow adipocyte-specific mouse model.
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Affiliation(s)
- Ziru Li
- Center for Molecular Medicine, MaineHealth Institute for Research, Scarborough, ME 04074, USA
| | - Clifford J Rosen
- Center for Molecular Medicine, MaineHealth Institute for Research, Scarborough, ME 04074, USA
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Afshari H, Noori S, Zarghi A. A novel combination of metformin and resveratrol alleviates hepatic steatosis by activating autophagy through the cAMP/AMPK/SIRT1 signaling pathway. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2023; 396:3135-3148. [PMID: 37209153 DOI: 10.1007/s00210-023-02520-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 05/03/2023] [Indexed: 05/22/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a prevalent liver disorder that is associated with the accumulation of triglycerides (TG) in hepatocytes. Resveratrol (RSV), as a natural product, and metformin have been reported to have potential lipid-lowering effects for the treatment of NAFLD via autophagy, but the combined effects of both have not yet been studied. The current study aimed to investigate the role of autophagy in the lipid-lowering effects of RSV, alone and in combination with metformin, on the hepatic steatosis model of HepG2 cells and elucidate the mechanism of action. Triglyceride measurement and real-time PCR showed that RSV-metformin reduced lipid accumulation and the expression of lipogenic genes in palmitic acid (PA)-induced HepG2 cells. Additionally, the LDH release assay indicated that this combination protected HepG2 cells against PA-induced cell death through autophagy. The western blotting analysis revealed that RSV-metformin induced autophagy by reducing the expression of p62 and increasing LC3-I and LC3-II proteins. This combination also enhanced cAMP, phosphorylated AMP-activated protein kinase (p-AMPK), and Beclin-1 levels in HepG2 cells. Furthermore, SIRT1 inhibitor treatment inhibited autophagy induced by RSV-metformin, which indicated the autophagy induction is SIRT1-dependent. This study demonstrated for the first time that RSV-metformin reduced hepatic steatosis by triggering autophagy via the cAMP/AMPK/SIRT1 signaling pathway.
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Affiliation(s)
- Havva Afshari
- Department of Biochemistry, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shokoofe Noori
- Department of Biochemistry, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Afshin Zarghi
- Department of Pharmaceutical Chemistry, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Ma C, Yu R, Li J, Chao J, Liu P. Targeting proteostasis network in osteoporosis: Pathological mechanisms and therapeutic implications. Ageing Res Rev 2023; 90:102024. [PMID: 37532006 DOI: 10.1016/j.arr.2023.102024] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 07/11/2023] [Accepted: 07/28/2023] [Indexed: 08/04/2023]
Abstract
As the most common bone disease, osteoporosis (OP) increases bone fragility and makes patients more vulnerable to the threat of osteoporotic fractures. With the ageing population in today's society, OP has become a huge and growing public health problem. Unfortunately, the clear pathogenesis of OP is still under exploration, and effective interventions are still scarce. Therefore, exploring new targets for pharmacological interventions to develop promising therapeutic drugs for OP is of great clinical value. Previous studies have shown that normal bone remodeling depends on proteostasis, whereas loss of proteostasis during ageing leads to the dysfunctional proteostasis network (PN) that fails to maintain bone homeostasis. Nevertheless, only a few studies have revealed the pathophysiological relationship between bone metabolism and a single component of PN, yet the role of PN as a whole in the pathogenesis of OP is still under investigation. This review comprehensively summarized the role of PN in the pathogenesis of OP and further discussed the potential of PN as innovative drug targets for the therapy of OP.
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Affiliation(s)
- Cong Ma
- Department of Orthopedics, Liyuan Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430077, China; Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Ronghui Yu
- Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Nanchang 330006, China
| | - Junhong Li
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Jiashuo Chao
- Department of Liver Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
| | - Ping Liu
- Department of Orthopedics, Liyuan Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430077, China.
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Shen X, Lan C, Lin Y, Zhang F, Zhang Y, Chen M, Yan S. Suppression of TLR4 prevents diabetic bone loss by regulating FTO-mediated m 6A modification. Int Immunopharmacol 2023; 122:110510. [PMID: 37413932 DOI: 10.1016/j.intimp.2023.110510] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 06/08/2023] [Accepted: 06/12/2023] [Indexed: 07/08/2023]
Abstract
Toll-like receptor-4 (TLR4) has been implicated in the development and progression of diabetic osteoporosis. However, the mechanisms underlying TLR4-regulated bone metabolism in diabetes are yet to be fully understood. Epigenetic modifications have been indicated as a possible mechanism leading to increased risk of osteoporosis and bone fracture. As N6-methyladenosine (m6A) is the most common epigenetic modification in eukaryotic mRNAs, we hypothesized that TLR4 regulates m6A modification in bone tissues of diabetic rats, thereby potentially explaining the pathogenesis of diabetic bone loss. m6A sequencing (m6A-seq) was performed in samples of the femur of TLR4-wild type (TLR4WT) and TLR4-knockout (TLR4KO) diabetic rats to identify genes with differential m6A modifications that may be associated with the bone loss phenotype. We found that in TLR4KO rats, the rapid weight loss of diabetic rats was prevented, and bone mineral density (BMD) was significantly increased. m6A-seq and Gene Ontology enrichment analysis revealed that m6A-modified genes in the femur of TLR4KO diabetic rats were associated with regulation of biological processes such as osteoclast differentiation. qRT-PCR analysis on the expression levels of the m6A-modified methyltransferases and demethylases demonstrated that only the m6A demethylase fat mass and obesity-associated protein(FTO)was decreased. Using an osteoclast cell model, we confirmed that TLR4-mediated osteoclast differentiation was induced by glycolipid toxicity via inhibition of FTO expression. Taken together, these results suggest that inhibition of TLR4 may prevent diabetic bone loss via regulation of FTO-mediated m6A modification.
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Affiliation(s)
- Ximei Shen
- Department of Endocrinology, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Department of Endocrinology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350212, China; Clinical Research Center for Metabolic Diseases of Fujian Province, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Fujian Key Laboratory of Glycolipid and Bone Mineral Metabolism, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Diabetes Research Institute of Fujian Province, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Metabolic Diseases Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China
| | - Chao Lan
- Department of Endocrinology, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Department of Endocrinology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350212, China; Clinical Research Center for Metabolic Diseases of Fujian Province, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Fujian Key Laboratory of Glycolipid and Bone Mineral Metabolism, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Diabetes Research Institute of Fujian Province, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Metabolic Diseases Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China
| | - Youfen Lin
- Department of Endocrinology, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Department of Endocrinology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350212, China; Clinical Research Center for Metabolic Diseases of Fujian Province, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Fujian Key Laboratory of Glycolipid and Bone Mineral Metabolism, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Diabetes Research Institute of Fujian Province, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Metabolic Diseases Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China
| | - Fuyashi Zhang
- Department of Endocrinology, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China
| | - Yongze Zhang
- Department of Endocrinology, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Department of Endocrinology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350212, China; Clinical Research Center for Metabolic Diseases of Fujian Province, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Fujian Key Laboratory of Glycolipid and Bone Mineral Metabolism, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Diabetes Research Institute of Fujian Province, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Metabolic Diseases Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China
| | - Mingyun Chen
- Department of Endocrinology, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Department of Endocrinology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350212, China; Clinical Research Center for Metabolic Diseases of Fujian Province, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Fujian Key Laboratory of Glycolipid and Bone Mineral Metabolism, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Diabetes Research Institute of Fujian Province, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Metabolic Diseases Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China
| | - Sunjie Yan
- Department of Endocrinology, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Department of Endocrinology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350212, China; Clinical Research Center for Metabolic Diseases of Fujian Province, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Fujian Key Laboratory of Glycolipid and Bone Mineral Metabolism, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Diabetes Research Institute of Fujian Province, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China; Metabolic Diseases Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, China.
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10
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Gerosa L, Malvandi AM, Malavolta M, Provinciali M, Lombardi G. Exploring cellular senescence in the musculoskeletal system: Any insights for biomarkers discovery? Ageing Res Rev 2023; 88:101943. [PMID: 37142059 DOI: 10.1016/j.arr.2023.101943] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/21/2023] [Accepted: 05/01/2023] [Indexed: 05/06/2023]
Abstract
The locomotor system comprises skeletal muscles and bones with active metabolism and cellular turnover. Chronic locomotor system disorders gradually arising with aging are inversely associated with the correct function of bone and muscles. Senescent cells appear more frequently in advanced ages or pathological conditions, and the accumulation of senescent cells in muscle tissue negatively correlates with muscle regeneration, which is crucial for maintaining strength and preventing frailty. Senescence in the bone microenvironment, osteoblasts, and osteocytes affects bone turnover favoring osteoporosis. It is likely that in response to injury and age-related damage over the lifetime, a subset of niche cells accumulates oxidative stress and DNA damage beyond the threshold that primes the onset of cellular senescence. These senescent cells may acquire resistance to apoptosis that, combined with the weakened immune system, results in impaired clearance of senescent cells and their accumulation. The secretory profile of senescent cells causes local inflammation, further spreading senescence in neighboring niche cells and impairing tissue homeostasis. The resulting impairment of turnover/tissue repair in the musculoskeletal system reduces the efficiency of the organ in response to environmental needs that finally lead to functional decline. Management of the musculoskeletal system at the cellular level can benefit the quality of life and reduce early aging. This work discusses current knowledge of cellular senescence of musculoskeletal tissues to conclude with biologically active biomarkers effective enough to reveal the underlying mechanisms of tissue flaws at the earliest possible.
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Affiliation(s)
- Laura Gerosa
- Laboratory of Experimental Biochemistry and Molecular Biology, IRCCS Istituto Ortopedico Galeazzi, Milano, Italy
| | - Amir Mohammad Malvandi
- Laboratory of Experimental Biochemistry and Molecular Biology, IRCCS Istituto Ortopedico Galeazzi, Milano, Italy.
| | - Marco Malavolta
- Advanced Technology Center for Aging Research, IRCCS INRCA, 60121 Ancona, Italy
| | - Mauro Provinciali
- Advanced Technology Center for Aging Research, IRCCS INRCA, 60121 Ancona, Italy
| | - Giovanni Lombardi
- Laboratory of Experimental Biochemistry and Molecular Biology, IRCCS Istituto Ortopedico Galeazzi, Milano, Italy; Department of Athletics, Strength and Conditioning, Poznań University of Physical Education, Poznań, Poland
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11
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Gielen E, Dupont J, Dejaeger M, Laurent MR. Sarcopenia, osteoporosis and frailty. Metabolism 2023; 145:155638. [PMID: 37348597 DOI: 10.1016/j.metabol.2023.155638] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 05/21/2023] [Accepted: 06/17/2023] [Indexed: 06/24/2023]
Abstract
Muscles and bones are intricately connected tissues displaying marked co-variation during development, growth, aging, and in many diseases. While the diagnosis and treatment of osteoporosis are well established in clinical practice, sarcopenia has only been classified internationally as a disease in 2016. Both conditions are associated with an increased risk of adverse health outcomes such as fractures, dysmobility and mortality. Rather than focusing on one dimension of bone or muscle mass or weakness, the concept of musculoskeletal frailty captures the overall loss of physiological reserves in the locomotor system with age. The term osteosarcopenia in particular refers to the double jeopardy of osteoporosis and sarcopenia. Muscle-bone interactions at the biomechanical, cellular, paracrine, endocrine, neuronal or nutritional level may contribute to the pathophysiology of osteosarcopenia. The paradigm wherein muscle force controls bone strength is increasingly facing competition from a model centering on the exchange of myokines, osteokines and adipokines. The most promising results have been obtained in preclinical models where common drug targets have been identified to treat these conditions simultaneously. In this narrative review, we critically summarize the current understanding of the definitions, epidemiology, pathophysiology, and treatment of osteosarcopenia as part of an integrative approach to musculoskeletal frailty.
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Affiliation(s)
- Evelien Gielen
- Gerontology and Geriatrics Unit, Department of Public Health and Primary Care, University of Leuven, Leuven, Belgium; Centre for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium
| | - Jolan Dupont
- Gerontology and Geriatrics Unit, Department of Public Health and Primary Care, University of Leuven, Leuven, Belgium
| | - Marian Dejaeger
- Gerontology and Geriatrics Unit, Department of Public Health and Primary Care, University of Leuven, Leuven, Belgium; Centre for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium
| | - Michaël R Laurent
- Centre for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium; Geriatrics Department, Imelda Hospital, Bonheiden, Belgium.
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12
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Menale C, Trinchese G, Aiello I, Scalia G, Dentice M, Mollica MP, Yoon NA, Diano S. Nutrient-Dependent Mitochondrial Fission Enhances Osteoblast Function. Nutrients 2023; 15:2222. [PMID: 37432387 DOI: 10.3390/nu15092222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 05/05/2023] [Accepted: 05/05/2023] [Indexed: 07/12/2023] Open
Abstract
BACKGROUND The bone synthesizing function of osteoblasts (OBs) is a highly demanding energy process that requires nutrients. However, how nutrient availability affects OBs behavior and bone mineralization remain to be fully understood. METHODS MC3T3-E1 cell line and primary OBs (OBs) cultures were treated with physiological levels of glucose (G; 5.5 mM) alone or with the addition of palmitic acid (G+PA) at different concentrations. Mitochondria morphology and activity were evaluated by fluorescence microscopy, qPCR, and oxygen consumption rate (OCR) measurement, and OBs function was assessed by mineralization assay. RESULTS The addition of non-lipotoxic levels of 25 μM PA to G increased mineralization in OBs. G+25 μM PA exposure reduced mitochondria size in OBs, which was associated with increased activation of dynamin-related protein 1, a mitochondrial fission protein, enhanced mitochondria OCR and ATP production, and increased expression of oxidative phosphorylation genes. Treatment with Mdivi-1, a putative inhibitor of mitochondrial fission, reduced osteogenesis and mitochondrial respiration in OBs. CONCLUSIONS Our results revealed that OBs function was enhanced in the presence of glucose and PA at 25 μM. This was associated with increased OBs mitochondrial respiration and dynamics. These results suggest a role for nutrient availability in bone physiology and pathophysiology.
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Affiliation(s)
- Ciro Menale
- Department of Clinical Medicine and Surgery, University of Naples "Federico II", 80131 Naples, Italy
| | - Giovanna Trinchese
- Department of Biology, University of Naples "Federico II", 80126 Naples, Italy
| | - Immacolata Aiello
- Department of Clinical Medicine and Surgery, University of Naples "Federico II", 80131 Naples, Italy
| | - Giulia Scalia
- CEINGE-Biotecnologie Avanzate Franco Salvatore, 80145 Naples, Italy
| | - Monica Dentice
- Department of Clinical Medicine and Surgery, University of Naples "Federico II", 80131 Naples, Italy
| | - Maria Pina Mollica
- Department of Biology, University of Naples "Federico II", 80126 Naples, Italy
- Centro Servizi Metrologici e Tecnologici Avanzati (CeSMA), Complesso Universitario di Monte Sant'Angelo, 80126 Naples, Italy
- Task Force on Microbiome Studies, University of Naples "Federico II", 80138 Naples, Italy
| | - Nal Ae Yoon
- Institute of Human Nutrition, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Sabrina Diano
- Institute of Human Nutrition, Columbia University Irving Medical Center, New York, NY 10032, USA
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, New York, NY 10032, USA
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
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13
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Bermudez B, Ishii T, Wu YH, Carpenter RD, Sherk VD. Energy Balance and Bone Health: a Nutrient Availability Perspective. Curr Osteoporos Rep 2023; 21:77-84. [PMID: 36542294 DOI: 10.1007/s11914-022-00765-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/27/2022] [Indexed: 12/24/2022]
Abstract
PURPOSE OF REVIEW Obesity is highly prevalent and is associated with bone fragility and fracture. The changing nutrient availability to bone in obesity is an important facet of bone health. The goal of this article is to summarize current knowledge on the effects of carbohydrate and dietary fat availability on bone, particularly in the context of other tissues. RECENT FINDINGS The skeleton is a primary site for fatty acid and glucose uptake. The trafficking of carbohydrates and fats into tissues changes with weight loss and periods of weight gain. Exercise acutely influences nutrient uptake into bone and may affect nutrient partitioning to bone. Bone cells secrete hormones that signal to the brain and other tissues information about its energetic state, which may alter whole-body nutrient trafficking. There is a critical need for studies to address the changes that metabolic perturbations have on nutrient availability in bone.
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Affiliation(s)
- Beatriz Bermudez
- Department of Mechanical Engineering, University of Colorado Denver, Denver, CO, USA
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Toru Ishii
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Yuan-Haw Wu
- Department of Surgery, Johns Hopkins University, Baltimore, MD, USA
| | - R Dana Carpenter
- Department of Mechanical Engineering, University of Colorado Denver, Denver, CO, USA
| | - Vanessa D Sherk
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
- Division of Translational and Clinical Sciences, Center for Scientific Review, National Institutes of Health, Bethesda, MD, USA.
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14
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Ji C, Zhang Z, Xu X, Song D, Zhang D. Hyperlipidemia impacts osteogenesis via lipophagy. Bone 2023; 167:116643. [PMID: 36513279 DOI: 10.1016/j.bone.2022.116643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 12/04/2022] [Accepted: 12/04/2022] [Indexed: 12/14/2022]
Abstract
The mechanism of the impact of hyperlipidemia on bone tissue homeostasis is unclear, and the role of lipophagy is yet to be investigated. This study investigated changes in lipophagy and osteogenesis levels under hyperlipemic conditions and explored the effects of lipophagy on bone regeneration. In vivo, femurs of mice with diet-induced moderate hyperlipidemia were ground out with a ball drill to create defects. In vitro, mouse osteoblast cell lines were grown in two different concentrations of the high-fat medium. We found that at hyperphysiological of lipid conditions, activation of lipophagy restored osteoblast function in a way, and similar results were observed in mice with diet-induced hyperlipidemia. Still, at suprahyperphysiological concentrations of lipid culture, the activation of lipophagy further inhibited osteogenesis, and inhibition of autophagy instead promoted osteogenesis to a small extent. These results demonstrate that lipophagy functions differently in diverse high-fat environments, suggesting that cellular and organismal changes in response to high-fat stimuli are dynamic. This may provide new ideas for improving bone dysfunction caused by lipid metabolism disorders.
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Affiliation(s)
- Chonghao Ji
- Department of Implantology, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University, Jinan, China; Shandong Key Laboratory of Oral Tissue Regeneration, Jinan, China; Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, China
| | - Zhanwei Zhang
- Department of Implantology, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University, Jinan, China; Shandong Key Laboratory of Oral Tissue Regeneration, Jinan, China; Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, China
| | - Xin Xu
- Department of Implantology, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University, Jinan, China; Shandong Key Laboratory of Oral Tissue Regeneration, Jinan, China; Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, China
| | - Dawei Song
- School of Stomatology, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China.
| | - Dongjiao Zhang
- Department of Implantology, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University, Jinan, China; Shandong Key Laboratory of Oral Tissue Regeneration, Jinan, China; Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, China.
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15
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He W, Tran A, Chen CT, Loganathan N, Bazinet RP, Belsham DD. Oleate restores altered autophagic flux to rescue palmitate lipotoxicity in hypothalamic neurons. Mol Cell Endocrinol 2022; 557:111753. [PMID: 35981630 DOI: 10.1016/j.mce.2022.111753] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 07/29/2022] [Accepted: 08/10/2022] [Indexed: 01/18/2023]
Abstract
Accumulation of excess lipids in non-adipose tissues, such as the hypothalamus, is termed lipotoxicity and causative of free fatty acid-mediated pathology in metabolic disease. This study aimed to elucidate the molecular mechanisms behind oleate (OA)- and palmitate (PA)-mediated changes in hypothalamic neurons. Using the well-characterized hypothalamic neuronal cell model, mHypoE-46, we assessed gene changes through qRT-PCR, cell death with quantitative imaging, PA metabolism using stable isotope labeling, and cellular mechanisms using pharmacological modulation of lipid metabolism and autophagic flux. Palmitate (PA) disrupts gene expression, including Npy, Grp78, and Il-6 mRNA in mHypoE-46 hypothalamic neurons. Blocking PA metabolism using triacsin-C prevented the increase of these genes, implying that these changes depend on PA intracellular metabolism. Co-incubation with oleate (OA) is also potently protective and prevents cell death induced by increasing concentrations of PA. However, OA does not decrease U-13C-PA incorporation into diacylglycerol and phospholipids. Remarkably, OA can reverse PA toxicity even after significant PA metabolism and cellular impairment. OA can restore PA-mediated impairment of autophagy to prevent or reverse the accumulation of PA metabolites through lysosomal degradation, and not through other reported mechanisms. The autophagic flux inhibitor chloroquine (CQ) mimics PA toxicity by upregulating autophagy-related genes, Npy, Grp78, and Il-6, an effect partially reversed by OA. CQ also prevented the OA defense against PA toxicity, whereas the autophagy inducer rapamycin provided some protection. Thus, PA impairment of autophagic flux significantly contributes to its lipotoxicity, and OA-mediated protection requires functional autophagy. Overall, our results suggest that impairment of autophagy contributes to hypothalamic lipotoxicity.
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Affiliation(s)
- Wenyuan He
- Department of Physiology, University of Toronto, Ontario, Canada
| | - Andy Tran
- Department of Physiology, University of Toronto, Ontario, Canada
| | - Chuck T Chen
- Department of Nutritional Sciences, University of Toronto, Ontario, Canada
| | | | - Richard P Bazinet
- Department of Nutritional Sciences, University of Toronto, Ontario, Canada
| | - Denise D Belsham
- Department of Physiology, University of Toronto, Ontario, Canada; Department of Medicine, University of Toronto, Ontario, Canada; Department of Obstetrics and Gynaecology, University of Toronto, Ontario, Canada.
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16
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Saedi AA, Wang Z, Shah A, Brotto M, Duque G. Comparative Analysis of Fat Composition in Marrow, Serum, and Muscle from Aging C57BL6 mice. Mech Ageing Dev 2022; 206:111690. [PMID: 35752298 DOI: 10.1016/j.mad.2022.111690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/08/2022] [Accepted: 06/21/2022] [Indexed: 10/17/2022]
Abstract
Osteosarcopenia is an age-related condition characterized by fragile bone and low muscle mass and function. Fat infiltration concomitantly contributes to age-related bone and muscle decline. Fat-secreted factors could be locally secreted in the muscle and bone marrow milieu affecting cell function and survival. However, the specific fat-related secretory factors that may simultaneously affect those tissues remain unknown. Using targeted-lipidomics approach, we comprehensively quantified fat composition (lipid mediators [LMs]) in bone marrow flush, gastrocnemius and serum obtained from 6-, 24- and 42-week-old C57BL6 mice. Compared to young mice (6wks), all tissues in older mice showed significantly higher levels of arachidonic acid (AA) and AA-derived eicosanoids, PGA 2, TXB 2, and 11,12-EET, which are known to affect muscle and bone function. Moreover, Lipoxin B4, another AA product and an enhancer of bone turnover and negative regulator for muscle, showed significantly lower values in older mice compared to young mice in both genders. Furthermore, eicosapentaenoic acid and docosahexaenoic acid autoxidation products (20-HDoHE, 11-HDoHE, 7-HDoHE and 4-HDoHE), and omega-3 fatty acids that negatively regulate bone and muscle health, were significantly higher in older mice. In conclusion, these results suggest that LMs could play a role in modulating musculoskeletal function during aging.
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Affiliation(s)
- Ahmed Al Saedi
- Australian Institute for Musculoskeletal Science (AIMSS), Geroscience & Osteosarcopenia Research Program, The University of Melbourne and Western Health, St. Albans, VIC, Australia; Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St. Albans, VIC, Australia
| | - Zhiying Wang
- Bone-Muscle Research Center, College of Nursing and Health Innovation, The University of Texas-Arlington, Arlington, TX 76019, USA
| | - Anup Shah
- Monash Bioinformatics Platform and Monash Proteomics & Metabolomics Facility, Monash University, Clayton, VIC, Australia
| | - Marco Brotto
- Bone-Muscle Research Center, College of Nursing and Health Innovation, The University of Texas-Arlington, Arlington, TX 76019, USA
| | - Gustavo Duque
- Australian Institute for Musculoskeletal Science (AIMSS), Geroscience & Osteosarcopenia Research Program, The University of Melbourne and Western Health, St. Albans, VIC, Australia; Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St. Albans, VIC, Australia.
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17
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Fu J, Yang Y, Zhu L, Chen Y, Liu B. Unraveling the Roles of Protein Kinases in Autophagy: An Update on Small-Molecule Compounds for Targeted Therapy. J Med Chem 2022; 65:5870-5885. [PMID: 35390258 DOI: 10.1021/acs.jmedchem.1c02053] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Protein kinases, which catalyze the phosphorylation of proteins, are involved in several important cellular processes, such as autophagy. Of note, autophagy, originally described as a mechanism for intracellular waste disposal and recovery, has been becoming a crucial biological process closely related to many types of human diseases. More recently, the roles of protein kinases in autophagy have been gradually elucidated, and the design of small-molecule compounds to modulate targets to positively or negatively interfere with the cytoprotective autophagy or autophagy-associated cell death may provide a new clue on the current targeted therapy. Thus, in this Perspective, we focus on summarizing the different roles of protein kinases, including positive, negative, and bidirectional regulations of autophagy. Moreover, we discuss several small-molecule compounds targeting these protein kinases in human diseases, highlighting their pivotal roles in autophagy for targeted therapeutic purposes.
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Affiliation(s)
- Jiahui Fu
- State Key Laboratory of Biotherapy and Cancer Center, Department of Thoracic Surgery, and Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yushang Yang
- State Key Laboratory of Biotherapy and Cancer Center, Department of Thoracic Surgery, and Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Lingjuan Zhu
- State Key Laboratory of Biotherapy and Cancer Center, Department of Thoracic Surgery, and Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yi Chen
- State Key Laboratory of Biotherapy and Cancer Center, Department of Thoracic Surgery, and Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Bo Liu
- State Key Laboratory of Biotherapy and Cancer Center, Department of Thoracic Surgery, and Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu 610041, China
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18
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Pan Y, Li Y, Liu P, Zhang Y, Li B, Liu Z, Shui G, Ma L. Metabolomics-Based Frailty Biomarkers in Older Chinese Adults. Front Med (Lausanne) 2022; 8:830723. [PMID: 35155487 PMCID: PMC8825494 DOI: 10.3389/fmed.2021.830723] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 12/20/2021] [Indexed: 11/14/2022] Open
Abstract
Background/Objectives Owing to accelerated population aging, health in older adults is becoming increasingly important. Frailty can reflect the health status and disease risks of older adults; however, appropriate biomarkers for early screening of frailty have not been identified. Here, we applied metabolomics to identify frailty biomarkers and potential pathogenic mechanisms of frailty. Methods Serum metabolic profiles from 25 frail and 49 non-frail (control) older adults were systematically investigated by liquid chromatography-mass spectrometry-based metabolomics. Results We identified 349 metabolites of 46 classes, with four increased and seven decreased metabolites in frail older adults. Pearson correlation analysis identified 11 and 21 metabolites that were positively and negatively correlated with grip strength, and 7 and 76 metabolites that were positively and negatively correlated with gait speed, respectively. Pathway analysis identified 10 metabolite sets and 13 pathways significantly associated with one or more frailty phenotype criteria. Conclusion These results revealed the metabolite characteristics of serum in frail older adults. Intermediates of carbohydrate metabolism (e.g., isocitrate, malate, fumarate, cis-aconitate, glucuronate, and pyruvate), saturated fatty acids (e.g., palmitic acid), unsaturated fatty acids (e.g., arachidonate and linoleic acid), and certain essential amino acids (e.g., tryptophan) may be candidate biomarkers for the early diagnosis of frailty. Mitochondrial function disorders, saturated fatty acid-mediated lipotoxicity, aberrant unsaturated fatty acid metabolism, and increased tryptophan degradation could be potential mechanisms of frailty.
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Affiliation(s)
- Yiming Pan
- Department of Geriatrics, National Research Center for Geriatric Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yun Li
- Department of Geriatrics, National Research Center for Geriatric Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Pan Liu
- Department of Geriatrics, National Research Center for Geriatric Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yaxin Zhang
- Department of Geriatrics, National Research Center for Geriatric Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Bowen Li
- LipidALL Technologies Company Limited, Changzhou, China
| | - Zuyun Liu
- Center for Clinical Big Data and Analytics, School of Public Health, Second Affiliated Hospital and Department of Big Data in Health Science, Zhejiang University School of Medicine, Hangzhou, China
| | - Guanghou Shui
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Lina Ma
- Department of Geriatrics, National Research Center for Geriatric Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China
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19
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Lin Y, Shen X, Ke Y, Lan C, Chen X, Liang B, Zhang Y, Yan S. Activation of osteoblast ferroptosis via the METTL3/ASK1‐p38 signaling pathway in high glucose and high fat (HGHF)‐induced diabetic bone loss. FASEB J 2022; 36:e22147. [PMID: 35104016 DOI: 10.1096/fj.202101610r] [Citation(s) in RCA: 64] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/11/2021] [Accepted: 12/21/2021] [Indexed: 12/14/2022]
Affiliation(s)
- Youfen Lin
- Department of Endocrinology the First Affiliated Hospital of Fujian Medical University Fuzhou China
| | - Ximei Shen
- Department of Endocrinology the First Affiliated Hospital of Fujian Medical University Fuzhou China
- Clinical Research Center for Metabolic Diseases of Fujian Province the First Affiliated Hospital of Fujian Medical University Fuzhou China
- Diabetes Research Institute of Fujian Province the First Affiliated Hospital of Fujian Medical University Fuzhou China
- Metabolic Diseases Research Institute the First Affiliated Hospital of Fujian Medical University Fuzhou China
| | - Yuzhen Ke
- Department of Endocrinology the First Affiliated Hospital of Fujian Medical University Fuzhou China
| | - Chao Lan
- Department of Endocrinology the First Affiliated Hospital of Fujian Medical University Fuzhou China
| | - Xiaoyuan Chen
- Department of Endocrinology the First Affiliated Hospital of Fujian Medical University Fuzhou China
| | - Bo Liang
- Department of Endocrinology the First Affiliated Hospital of Fujian Medical University Fuzhou China
| | - Yongze Zhang
- Department of Endocrinology the First Affiliated Hospital of Fujian Medical University Fuzhou China
| | - Sunjie Yan
- Department of Endocrinology the First Affiliated Hospital of Fujian Medical University Fuzhou China
- Clinical Research Center for Metabolic Diseases of Fujian Province the First Affiliated Hospital of Fujian Medical University Fuzhou China
- Diabetes Research Institute of Fujian Province the First Affiliated Hospital of Fujian Medical University Fuzhou China
- Metabolic Diseases Research Institute the First Affiliated Hospital of Fujian Medical University Fuzhou China
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20
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Rinonapoli G, Pace V, Ruggiero C, Ceccarini P, Bisaccia M, Meccariello L, Caraffa A. Obesity and Bone: A Complex Relationship. Int J Mol Sci 2021; 22:ijms222413662. [PMID: 34948466 PMCID: PMC8706946 DOI: 10.3390/ijms222413662] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 12/13/2021] [Accepted: 12/13/2021] [Indexed: 12/29/2022] Open
Abstract
There is a large literature on the relationship between obesity and bone. What we can conclude from this review is that the increase in body weight causes an increase in BMD, both for a mechanical effect and for the greater amount of estrogens present in the adipose tissue. Nevertheless, despite an apparent strengthening of the bone witnessed by the increased BMD, the risk of fracture is higher. The greater risk of fracture in the obese subject is due to various factors, which are carefully analyzed by the Authors. These factors can be divided into metabolic factors and increased risk of falls. Fractures have an atypical distribution in the obese, with a lower incidence of typical osteoporotic fractures, such as those of hip, spine and wrist, and an increase in fractures of the ankle, upper leg, and humerus. In children, the distribution is different, but it is not the same in obese and normal-weight children. Specifically, the fractures of the lower limb are much more frequent in obese children. Sarcopenic obesity plays an important role. The authors also review the available literature regarding the effects of high-fat diet, weight loss and bariatric surgery.
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Affiliation(s)
- Giuseppe Rinonapoli
- Orthopaedic and Traumatology Unit, Department of Medicine, University of Perugia, 06156 Perugia, Italy; (V.P.); (P.C.); (A.C.)
- Correspondence:
| | - Valerio Pace
- Orthopaedic and Traumatology Unit, Department of Medicine, University of Perugia, 06156 Perugia, Italy; (V.P.); (P.C.); (A.C.)
| | - Carmelinda Ruggiero
- Orthogeriatric Service, Geriatric Unit, Institute of Gerontology and Geriatrics, Department of Medicine, University of Perugia, 06156 Perugia, Italy;
| | - Paolo Ceccarini
- Orthopaedic and Traumatology Unit, Department of Medicine, University of Perugia, 06156 Perugia, Italy; (V.P.); (P.C.); (A.C.)
| | - Michele Bisaccia
- Department of Orthopaedics and Traumatology, AORN San Pio “Gaetano Rummo Hospital”, Via R.Delcogliano, 82100 Benevento, Italy; (M.B.); (L.M.)
| | - Luigi Meccariello
- Department of Orthopaedics and Traumatology, AORN San Pio “Gaetano Rummo Hospital”, Via R.Delcogliano, 82100 Benevento, Italy; (M.B.); (L.M.)
| | - Auro Caraffa
- Orthopaedic and Traumatology Unit, Department of Medicine, University of Perugia, 06156 Perugia, Italy; (V.P.); (P.C.); (A.C.)
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21
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Tang Y, Mo Y, Xin D, Xiong Z, Zeng L, Luo G, Cao Y. Regulation of osteoblast autophagy based on PI3K/AKT/mTOR signaling pathway study on the effect of β-ecdysterone on fracture healing. J Orthop Surg Res 2021; 16:719. [PMID: 34924000 PMCID: PMC8684673 DOI: 10.1186/s13018-021-02862-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 11/24/2021] [Indexed: 11/24/2022] Open
Abstract
Objectives To investigate the effects of β-ecdysterone on fracture healing and the underlying mechanism. Methods MTT assay was used to detect the cell viability. AO/PI and flow cytometry assays were used to determine the apoptotic rate. The expression level of RunX2, ATG7 and LC3 was evaluated by qRT-PCR and Western blot assays. X-ray and HE staining were conducted on the fractured femur. Immunohistochemical assay was used to detect the expression level of Beclin-1 and immunofluorescence assay was used to measure the expression level of LC3 in the fractured femurs. Western blot was utilized to determine the expression level of PI3K, p-AKT1, AKT1, p-mTOR, mTOR, p-p70S6K, and p70S6K. Results The ALP activity and the expression of RunX2 in fractured osteoblasts were significantly elevated, the apoptotic rate was suppressed by rapamycin, 60, and 80 μM β-ecdysterone. The state of autophagy both in fractured osteoblasts and femurs was facilitated by rapamycin and β-ecdysterone. Compared to control, Garrett score was significantly promoted in rapamycin and β-ecdysterone groups, accompanied by ameliorated pathological state. Lastly, the PI3K/AKT/mTOR pathway both in fractured osteoblasts and femurs was inhibited by rapamycin and β-ecdysterone. Conclusion β-ecdysterone might facilitate fracture healing by activating autophagy through suppressing PI3K/AKT/mTOR signal pathway.
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Affiliation(s)
- Yanghua Tang
- Department of Orthopedics, Hospital of Traditional Chinese Medicine of Xiaoshan District, No. 156, Yucai Road, Xiaoshan District, Hangzhou City, Zhejiang Province, China
| | - Yafeng Mo
- Department of Orthopedics, Hospital of Traditional Chinese Medicine of Xiaoshan District, No. 156, Yucai Road, Xiaoshan District, Hangzhou City, Zhejiang Province, China
| | - Dawei Xin
- Department of Orthopedics, Hospital of Traditional Chinese Medicine of Xiaoshan District, No. 156, Yucai Road, Xiaoshan District, Hangzhou City, Zhejiang Province, China
| | - Zhenfei Xiong
- Department of Orthopedics, Hospital of Traditional Chinese Medicine of Xiaoshan District, No. 156, Yucai Road, Xiaoshan District, Hangzhou City, Zhejiang Province, China
| | - Linru Zeng
- Department of Orthopedics, Hospital of Traditional Chinese Medicine of Xiaoshan District, No. 156, Yucai Road, Xiaoshan District, Hangzhou City, Zhejiang Province, China
| | - Gan Luo
- Department of Orthopedics, Hospital of Traditional Chinese Medicine of Xiaoshan District, No. 156, Yucai Road, Xiaoshan District, Hangzhou City, Zhejiang Province, China
| | - Yanguang Cao
- Department of Orthopedics, The Second Affiliated Hospital of Zhejiang Chinese Medical University, No. 318, ChaoWang Road, Gongshu District, Hangzhou City, Zhejiang Province, China.
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22
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FGF19 protects against obesity-induced bone loss by promoting osteogenic differentiation. Biomed Pharmacother 2021; 146:112524. [PMID: 34906775 DOI: 10.1016/j.biopha.2021.112524] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 11/20/2021] [Accepted: 12/06/2021] [Indexed: 12/12/2022] Open
Abstract
Human fibroblast growth factor 19 (FGF19) has become a potential therapeutic target for metabolic-related diseases. However, the effects of FGF19 on obesity-induced bone loss have not been completely elucidated. The aim of this study was to investigate the protective effects of FGF19 in high-fat diet (HFD)-fed obese mice and palmitic acid (PA)-treated osteoblasts and to further explore its underlying mechanisms. In vivo, we found that FGF19 alleviated the decreased bone mineral density (BMD) induced by HFD. Micro-CT analysis of femur samples and histological analysis indicated that FGF19 alleviated HFD-induced loss of bone trabeculae and damage to the bone trabecular structure. In vitro, the results suggested that FGF19 ameliorated the PA-induced decline in osteoblast proliferation, increased cell death and impaired cell morphology. Additionally, FGF19 protected against the decline in activation of alkaline phosphatase (ALP) and protein expression of Collagen-1, Runx-2, and osteopontin (OPN) induced by PA. Furthermore, FGF19 might enhance osteogenic differentiation via the Wnt/β-catenin pathway and inhibit osteoclastogenesis by regulating the osteoprotegerin (OPG)/receptor activator of NF-κB ligand (RANKL) axis, thus attenuating the negative effect of PA in osteoblasts. In conclusion, our results suggested that FGF19 might promote osteogenic differentiation partially through activation of the Wnt/β-catenin pathway and alleviate obesity-induced bone loss.
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23
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Up-regulation of SIRT1 induced by 17beta-estradiol promotes autophagy and inhibits apoptosis in osteoblasts. Aging (Albany NY) 2021; 13:23652-23671. [PMID: 34711685 PMCID: PMC8580331 DOI: 10.18632/aging.203639] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 09/11/2021] [Indexed: 12/11/2022]
Abstract
Osteoporosis is a common systemic skeletal metabolism disorder resulting in bone fragility and increased fracture risk. Silent information regulator factor 2 homolog 1 (SIRT1) is crucial in the regulation of several biological processes, including bone metabolism, autophagy, apoptosis, and aging. This study aimed to assess whether the up-regulation of SIRT1 induced by 17beta-estradiol (17β-E2) could promote autophagy and inhibit apoptosis in osteoblasts via the AMPK-mTOR and FOXO3a pathways, respectively. The study found that 17β-E2 (10-6 M) administration induced the up-regulation of SIRT1 in osteoblasts. Up-regulation of SIRT1 induced by 17β-E2 increased the expression level of LC3, Beclin-1, Bcl-2, p-AMPK, FOXO3a but decreased caspase-3 and p-mTOR expression, and then promoted autophagy and inhibited apoptosis. More autophagosomes were observed under a transmission electron microscope (TEM) in 17β-E2 and SRT1720 (a selective SIRT1 activator) co-treated group. When Ex527 (a SIRT1-specific inhibitor) was pretreated, the reversed changes were observed. Taken together, our findings demonstrated that the up-regulation of SIRT1 induced by 17β-E2 could promote autophagy via the AMPK-mTOR pathway and inhibit apoptosis via the FOXO3a activation in osteoblasts, and SIRT1 might become a more significant target in osteoporosis treatment.
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24
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Liang B, Shen X, Lan C, Lin Y, Li C, Zhong S, Yan S. Glycolipid toxicity induces osteogenic dysfunction via the TLR4/S100B pathway. Int Immunopharmacol 2021; 97:107792. [PMID: 34051593 DOI: 10.1016/j.intimp.2021.107792] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/11/2021] [Accepted: 05/16/2021] [Indexed: 01/22/2023]
Abstract
Diabetes can cause bone metabolism disorders and osteoporosis. The occurrence of both diabetes mellitus and osteoporosis increases the disability and mortality of elderly individuals due to pathological fracture. Abnormal metabolism of nutrientsis considered to be one of the important mechanisms of diabetes mellitus-induced osteoporosis. This study preliminarily explored the roles of TLR4 (Toll-like receptor 4) and S100B in osteogenic dysfunction induced by glycolipid toxicity. In this study, a diabetic rat model and TLR4-knockdown diabetic rat model were used in vivo. MC3T3-E1 cells in a high glucose and palmitic acid environment were used as glycolipid toxicity cell models in vitro. We investigated the effects of TLR4 and S100B on osteogenesis by overexpression or inhibition of TLR4 and S100B in vitro. We found that when TLR4 or S100B was inhibited, ALP and OCN were significantly up-regulated and p-ERK was significantly down regulated in the glycolipid model. These results suggest that TLR4/S100B may play a role in reducing glycolipid toxicity by regulating ERK phosphorylation.
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Affiliation(s)
- Bo Liang
- Department of Endocrinology, M.D. Candidate, The First Affiliated Hospital of Fujian Medical University, China; Department of Endocrinology, The Second Affiliated Hospital of Fujian Medical University, China
| | - Ximei Shen
- Department of Endocrinology, M.D. Candidate, The First Affiliated Hospital of Fujian Medical University, China; Diabetes Research Institute of Fujian Province, Fuzhou, Fujian, China
| | - Chao Lan
- Department of Endocrinology, M.D. Candidate, The First Affiliated Hospital of Fujian Medical University, China
| | - Youfen Lin
- Department of Endocrinology, M.D. Candidate, The First Affiliated Hospital of Fujian Medical University, China
| | - Chuanchuan Li
- Department of Endocrinology, M.D. Candidate, The First Affiliated Hospital of Fujian Medical University, China
| | - Shuai Zhong
- Department of Endocrinology, M.D. Candidate, The First Affiliated Hospital of Fujian Medical University, China
| | - Sunjie Yan
- Department of Endocrinology, M.D. Candidate, The First Affiliated Hospital of Fujian Medical University, China; Diabetes Research Institute of Fujian Province, Fuzhou, Fujian, China.
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25
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Targeting intramuscular adipose tissue expansion to preserve contractile function in volumetric muscle loss: A potentially novel therapy? Curr Opin Pharmacol 2021; 58:21-26. [PMID: 33848932 DOI: 10.1016/j.coph.2021.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 03/06/2021] [Accepted: 03/11/2021] [Indexed: 11/20/2022]
Abstract
In volumetric muscle loss (VML), the severity of trauma exceeds a muscle's regenerative capacity. VML causes permanent functional impairments for which there are no rehabilitative, pharmacological, or regenerative medicine interventions. Driving failed regeneration in VML is a hostile microenvironment characterized by heightened inflammation, fibrosis, and denervation, which may reduce the remaining muscle tissue's quality, and stimulate intramuscular adipose tissue (IMAT) expansion. IMAT is increased in various muscle disease states, and has known lipotoxic effects on regeneration and contractile function. The contribution of ectopic fat deposition to the hostile VML microenvironment at the injury site and in the remaining tissue warrants further investigation. Targeting IMAT may lead to novel therapeutic strategies for improving functional outcomes in VML.
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26
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Goodman CA, Davey JR, Hagg A, Parker BL, Gregorevic P. Dynamic Changes to the Skeletal Muscle Proteome and Ubiquitinome Induced by the E3 Ligase, ASB2β. Mol Cell Proteomics 2021; 20:100050. [PMID: 33516941 PMCID: PMC8042406 DOI: 10.1016/j.mcpro.2021.100050] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 01/12/2021] [Accepted: 01/15/2021] [Indexed: 02/06/2023] Open
Abstract
Ubiquitination is a posttranslational protein modification that has been shown to have a range of effects, including regulation of protein function, interaction, localization, and degradation. We have previously shown that the muscle-specific ubiquitin E3 ligase, ASB2β, is downregulated in models of muscle growth and that overexpression ASB2β is sufficient to induce muscle atrophy. To gain insight into the effects of increased ASB2β expression on skeletal muscle mass and function, we used liquid chromatography coupled to tandem mass spectrometry to investigate ASB2β-mediated changes to the skeletal muscle proteome and ubiquitinome, via a parallel analysis of remnant diGly-modified peptides. The results show that viral vector-mediated ASB2β overexpression in murine muscles causes progressive muscle atrophy and impairment of force-producing capacity, while ASB2β knockdown induces mild muscle hypertrophy. ASB2β-induced muscle atrophy and dysfunction were associated with the early downregulation of mitochondrial and contractile protein abundance and the upregulation of proteins involved in proteasome-mediated protein degradation (including other E3 ligases), protein synthesis, and the cytoskeleton/sarcomere. The overexpression ASB2β also resulted in marked changes in protein ubiquitination; however, there was no simple relationship between changes in ubiquitination status and protein abundance. To investigate proteins that interact with ASB2β and, therefore, potential ASB2β targets, Flag-tagged wild-type ASB2β, and a mutant ASB2β lacking the C-terminal SOCS box domain (dSOCS) were immunoprecipitated from C2C12 myotubes and subjected to label-free proteomic analysis to determine the ASB2β interactome. ASB2β was found to interact with a range of cytoskeletal and nuclear proteins. When combined with the in vivo ubiquitinomic data, our studies have identified novel putative ASB2β target substrates that warrant further investigation. These findings provide novel insight into the complexity of proteome and ubiquitinome changes that occur during E3 ligase-mediated skeletal muscle atrophy and dysfunction.
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Affiliation(s)
- Craig A Goodman
- Department of Physiology, Centre for Muscle Research (CMR), The University of Melbourne, Victoria, Australia; Australian Institute for Musculoskeletal Science (AIMSS), Sunshine Hospital, The University of Melbourne, St Albans, Victoria, Australia
| | - Jonathan R Davey
- Department of Physiology, Centre for Muscle Research (CMR), The University of Melbourne, Victoria, Australia; Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Adam Hagg
- Department of Physiology, Centre for Muscle Research (CMR), The University of Melbourne, Victoria, Australia; Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia; Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Benjamin L Parker
- Department of Physiology, Centre for Muscle Research (CMR), The University of Melbourne, Victoria, Australia; Charles Perkins Centre, School of Life and Environmental Science, The University of Sydney, Sydney, NSW, Australia.
| | - Paul Gregorevic
- Department of Physiology, Centre for Muscle Research (CMR), The University of Melbourne, Victoria, Australia; Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia; Department of Neurology, The University of Washington School of Medicine, Seattle, Washington, USA.
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27
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Guo YF, Su T, Yang M, Li CJ, Guo Q, Xiao Y, Huang Y, Liu Y, Luo XH. The role of autophagy in bone homeostasis. J Cell Physiol 2021; 236:4152-4173. [PMID: 33452680 DOI: 10.1002/jcp.30111] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 09/24/2020] [Accepted: 10/05/2020] [Indexed: 12/15/2022]
Abstract
Autophagy is an evolutionarily conserved intracellular process and is considered one of the main catabolism pathways. In the process of autophagy, cells are digested nonselectively or selectively to recover nutrients and energy, so it is regarded as an antiaging process. In addition to the essential role of autophagy in cellular homeostasis, autophagy is a stress response mechanism for cell survival. Here, we review recent literature describing the pathway of autophagy and its role in different bone cell types, including osteoblasts, osteoclasts, and osteocytes. Also discussed is the mechanism of autophagy in bone diseases associated with bone homeostasis, including osteoporosis and Paget's disease. Finally, we discuss the application of autophagy regulators in bone diseases. This review aims to introduce autophagy, summarize the understanding of its relevance in bone physiology, and discuss its role and therapeutic potential in the pathogenesis of bone diseases such as osteoporosis.
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Affiliation(s)
- Yi-Fan Guo
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Tian Su
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Mi Yang
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Chang-Jun Li
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Qi Guo
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Ye Xiao
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Yan Huang
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Ya Liu
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Xiang-Hang Luo
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital of Central South University, Changsha, Hunan, China
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28
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Hou J, He C, He W, Yang M, Luo X, Li C. Obesity and Bone Health: A Complex Link. Front Cell Dev Biol 2020; 8:600181. [PMID: 33409277 PMCID: PMC7779553 DOI: 10.3389/fcell.2020.600181] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 11/30/2020] [Indexed: 12/12/2022] Open
Abstract
So far, the connections between obesity and skeleton have been extensively explored, but the results are inconsistent. Obesity is thought to affect bone health through a variety of mechanisms, including body weight, fat volume, bone formation/resorption, proinflammatory cytokines together with bone marrow microenvironment. In this review, we will mainly describe the effects of adipokines secreted by white adipose tissue on bone cells, as well as the interaction between brown adipose tissue, bone marrow adipose tissue, and bone metabolism. Meanwhile, this review also reviews the evidence for the effects of adipose tissue and its distribution on bone mass and bone-related diseases, along with the correlation between different populations with obesity and bone health. And we describe changes in bone metabolism in patients with anorexia nervosa or type 2 diabetes. In summary, all of these findings show that the response of skeleton to obesity is complex and depends on diversified factors, such as mechanical loading, obesity type, the location of adipose tissue, gender, age, bone sites, and secreted cytokines, and that these factors may exert a primary function in bone health.
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Affiliation(s)
- Jing Hou
- Department of Endocrinology, Endocrinology Research Center, The Xiangya Hospital of Central South University, Changsha, China
| | - Chen He
- Department of Endocrinology, Endocrinology Research Center, The Xiangya Hospital of Central South University, Changsha, China
| | - Wenzhen He
- Department of Endocrinology, Endocrinology Research Center, The Xiangya Hospital of Central South University, Changsha, China
| | - Mi Yang
- Department of Endocrinology, Endocrinology Research Center, The Xiangya Hospital of Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders (Xiangya Hospital), Changsha, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
| | - Xianghang Luo
- Department of Endocrinology, Endocrinology Research Center, The Xiangya Hospital of Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders (Xiangya Hospital), Changsha, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
| | - Changjun Li
- Department of Endocrinology, Endocrinology Research Center, The Xiangya Hospital of Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders (Xiangya Hospital), Changsha, China
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
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29
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Al Saedi A, Myers DE, Stupka N, Duque G. 1,25(OH) 2D 3 ameliorates palmitate-induced lipotoxicity in human primary osteoblasts leading to improved viability and function. Bone 2020; 141:115672. [PMID: 33011427 DOI: 10.1016/j.bone.2020.115672] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/22/2020] [Accepted: 09/28/2020] [Indexed: 12/13/2022]
Abstract
Contributing to bone loss with aging is a progressive reduction in osteoblast number and function leading to decreased bone formation. In aging bone, mesenchymal stem cells decrease in number and their differentiation potential into osteoblasts is reduced. Instead, there is a shift towards adipogenic differentiation and increased lipid accumulation in the marrow of osteoporotic bones. Bone marrow adipocytes produce palmitic acid (PA), a saturated fatty acid, which is toxic to osteoblasts in vitro. Vitamin D (1,25(OH)2D3) stimulates osteoblastogenesis and has known anti-apoptotic effects on osteoblasts, as such it may protect human primary osteoblasts from PA-induced lipotoxicity. Here, the effects of PA (250 μM) or 1,25(OH)2D3 (10-8 M), alone or in combination, on osteoblast differentiation and mineralization, viability and autophagy were investigated. In PA-treated osteoblasts, 1,25(OH)2D3 ameliorated the decrease in the mRNA transcript abundance of representative palmitoylation (ZDHHC1, ZDHHC2 and ZDHHC12) and osteogenic (alkaline phosphatase and osteocalcin) genes. Collectively these gene regulate signaling pathways pertinent to osteoblastogenesis. In osteoblasts treated with PA and 1,25(OH)2D3, the capacity to undergo differentiation and mineralization was recovered and cell viability was increased when compared to osteoblasts treated with PA alone. 1,25(OH)2D3, irrespective of PA treatment, increased the expression of key osteogenic signaling proteins; specifically, SMAD1-3,5, Runx2 and β-catenin. 1,25(OH)2D3 also attenuated the high level of impaired autophagy induced by PA and potentiated a shift towards activated, functional autophagy and increased flux through autolysosomes. Altogether, these findings provide in vitro evidence regarding the potential of 1,25(OH)2D3 to protect osteoblasts from lipotoxicity by modulating autophagy and facilitating cell differentiation, which may enhance bone formation in an osteoporotic microenvironment with a high level of marrow adipose tissue.
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Affiliation(s)
- Ahmed Al Saedi
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, VIC, Australia; Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St. Albans, VIC, Australia
| | - Damian E Myers
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, VIC, Australia; Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St. Albans, VIC, Australia
| | - Nicole Stupka
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, VIC, 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, St. Albans, VIC, Australia; Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St. Albans, VIC, Australia.
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30
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Ando T, Ichikawa J, Fujimaki T, Taniguchi N, Takayama Y, Haro H. Gemcitabine and Rapamycin Exhibit Additive Effect against Osteosarcoma by Targeting Autophagy and Apoptosis. Cancers (Basel) 2020; 12:cancers12113097. [PMID: 33114161 PMCID: PMC7690839 DOI: 10.3390/cancers12113097] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 10/12/2020] [Accepted: 10/21/2020] [Indexed: 12/11/2022] Open
Abstract
The overall prognosis for sarcoma-based cancer patients has remained largely unchanged over the past 10 years. Because there is no effective anticancer drug for patients with chemoresistant osteosarcoma (OS), novel approaches are needed to improve the prognosis. Here, we investigated whether rapamycin (Rapa) could enhance the anti-tumor effects of gemcitabine (Gem) in OS. Gem dose-dependently killed the OS cells, but exhibited much lower cytotoxicity on osteoblasts. Treatment with a combination Gem and Rapa was much more effective than that of either single agent with respect to reducing cell viability, cell invasion, cell migration, and vascular endothelial growth factor production in vitro. Moreover, the combination of these agents suppressed tumor growth, angiogenesis, and lung metastasis in allograft and xenograft murine models of OS with minimal adverse effects. Overall, the combination therapy prolonged the overall survival of tumor-bearing mice. Mechanistically, Gem induced apoptosis and increased the levels of cleaved caspases, while Rapa induced autophagy and microtubule-associated protein light chain 3 (LC3)-I/LC3-II expression both in vitro and in vivo. Our findings suggest that chemotherapy using Gem combined with Rapa may be a novel and promising therapeutic approach for the treatment of OS.
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31
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Li X, Xu J, Dai B, Wang X, Guo Q, Qin L. Targeting autophagy in osteoporosis: From pathophysiology to potential therapy. Ageing Res Rev 2020; 62:101098. [PMID: 32535273 DOI: 10.1016/j.arr.2020.101098] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/26/2020] [Accepted: 06/03/2020] [Indexed: 12/19/2022]
Abstract
Osteoporosis is a highly prevalent disorder characterized by the loss of bone mass and microarchitecture deterioration of bone tissue, attributed to various factors, including menopause (primary), aging (primary) and adverse effects of relevant medications (secondary). In recent decades, knowledge regarding the etiological mechanisms underpinning osteoporosis emphasizes that bone cellular homeostasis, including the maintenance of cell functions, differentiation, and the response to stress, is tightly regulated by autophagy, which is a cell survival mechanism for eliminating and recycling damaged proteins and organelles. With the important roles in the maintenance of cellular homeostasis and organ function, autophagy has emerged as a potential target for the prevention and treatment of osteoporosis. In this review, we update and discuss the pathophysiology of autophagy in normal bone cell life cycle and metabolism. Then, the alternations of autophagy in primary and secondary osteoporosis, and the accompanied pathological process are discussed. Finally, we discuss current strategies, limitations, and challenges involved in targeting relevant pathways and propose strategies by which such hurdles may be circumvented in the future for their translation into clinical validations and applications for the prevention and treatment of osteoporosis.
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32
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Lamming DW, Salmon AB. TORwards a Victory Over Aging. J Gerontol A Biol Sci Med Sci 2020; 75:1-3. [PMID: 31544928 DOI: 10.1093/gerona/glz212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Indexed: 01/12/2023] Open
Affiliation(s)
- Dudley W Lamming
- William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin.,Department of Medicine, University of Wisconsin-Madison, San Antonio
| | - Adam B Salmon
- Geriatric Research, Education and Clinical Center, South Texas Veterans Healthcare System, San Antonio.,The Sam and Ann Barshop Institute for Longevity and Aging Studies, Department of Molecular Medicine, UT Health San Antonio, Texas
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33
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Abstract
BACKGROUND Osteosarcopenia, the presence of osteopenia/osteoporosis and sarcopenia, is an emerging geriatric giant, which poses a serious global health burden. METHODS AND RESULTS The prevalence of osteosarcopenia ranges in community-dwelling older adults [5-37% (≥65 years)] with the highest rates observed in those with fractures (low-trauma fracture: ~46%; hip fracture: 17.1-96.3%). Among 2353 community-dwelling adults, risk factors associated with osteosarcopenia include older age [men: 14.3% (60-64 years) to 59.4% (≥75 years); women: 20.3% (60-64 years) to 48.3% (≥75 years), P < 0.05], physical inactivity [inverse relationship: 0.64, 95% confidence interval (CI) 0.46-0.88 (sexes combined)], low body mass index (inverse relationship: men: 0.84, 95% CI 0.81-0.88; women: 0.77, 95% CI 0.74-0.80), and higher fat mass (men: 1.46, 95% CI 1.11-1.92; women: 2.25, 95% CI 1.71-2.95). Among 148 geriatric inpatients, osteosarcopenic individuals demonstrate poorer nutritional status (mini-nutritional assessment scores: 8.50 ± 2.52 points, P < 0.001) vs. osteoporosis or sarcopenia alone, while among 253 older Australians, osteosarcopenia is associated with impaired balance and functional capacity [odds ratios (ORs): 2.56-7.19; P < 0.05] vs. non-osteosarcopenia. Osteosarcopenia also associates with falls (ORs: 2.83-3.63; P < 0.05), fractures (ORs: 3.86-4.38; P < 0.05), and earlier death [hazard ratio (1-year follow-up): 1.84, 95% CI; 0.69-4.92, P = 0.023] vs. non-osteosarcopenia. CONCLUSIONS This syndrome is expected to grow in age-related and disease-related states, a likely consequence of immunosenescence coinciding with increased sedentarism, obesity, and fat infiltration of muscle and bone. Evidence suggests the pathophysiology of osteosarcopenia includes genetic polymorphisms, reduced mechanical loading, and impaired endocrine functioning, as well as altered crosstalk between muscle, bone, and fat cells. Clinicians should screen for osteosarcopenia via imaging methods (i.e. dual-energy X-ray absorptiometry) to quantify muscle and bone mass, in addition to assessing muscle strength (i.e. grip strength) and functional capacity (i.e. gait speed). A comprehensive geriatric assessment, including medical history and risk factors, must also be undertaken. Treatment of this syndrome should include osteoporotic drugs [bone anabolics/antiresorptives (i.e. teriparatide, denosumab, bisphosphates)] where indicated, and progressive resistance and balance exercises (at least 2-3 times/week). To maximize musculoskeletal health, nutritional recommendations [protein (1.2-1.5 g/kg/day), vitamin D (800-1000 IU/day), calcium (1300 mg/day), and creatine (3-5 g/day)] must also be met. It is anticipated that diagnosis and treatment for osteosarcopenia will become part of routine healthcare in the future. However, further work is required to identify biomarkers, which, in turn, may increase diagnosis, risk stratification, and targeted treatments to improve health outcomes.
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Affiliation(s)
- Ben Kirk
- Department of Medicine, Western Health, Melbourne Medical SchoolUniversity of MelbourneMelbourneAustralia
- Australian Institute for Musculoskeletal Science (AIMSS)University of Melbourne and Western HealthMelbourneAustralia
| | - Jesse Zanker
- Department of Medicine, Western Health, Melbourne Medical SchoolUniversity of MelbourneMelbourneAustralia
- Australian Institute for Musculoskeletal Science (AIMSS)University of Melbourne and Western HealthMelbourneAustralia
| | - Gustavo Duque
- Department of Medicine, Western Health, Melbourne Medical SchoolUniversity of MelbourneMelbourneAustralia
- Australian Institute for Musculoskeletal Science (AIMSS)University of Melbourne and Western HealthMelbourneAustralia
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Abstract
Osteoporosis is a condition where bone resorption exceeds bone formation leading to degeneration. With an aging population, the prevalence of osteoporosis is on the rise. Although advances in the field have made progress in targeting the mechanisms of the disease, the efficacy of current treatments remains limited and is complicated by unexpected side effects. Therefore, to overcome this treatment gap, new approaches are needed to identify and elucidate the cellular mechanisms mediating the pathogenesis of osteoporosis, which requires a strong understanding of bone biology. This chapter will focus on bone cells (osteoclasts, osteoblasts, and osteocytes) and their role in the bone turnover process in normal physiology and in pathology. With regard to osteoclast function, the regulators and underpinning signaling pathways leading to bone resorption will be discussed. Decreased osteoblastogenesis also contributes to bone deterioration with aging and osteoporosis; hence the factors and signaling pathways mediating osteoblast formation and function will be examined. Osteocytes are mature osteoblasts embedded in bone matrix and act as endocrine cells; their role in bone health and pathology will also be reviewed. In addition, this chapter will explore the emerging role of adipocytes in bone biology and the implications of increased bone marrow fat infiltration with aging on bone degeneration. In conclusion, a greater understanding of the pathogenesis of osteoporosis is of utmost importance in order to develop more effective treatments for osteoporosis and other bone diseases.
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Affiliation(s)
- Ahmed Al Saedi
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, VIC, Australia
- Department of Medicine, Melbourne Medical School - Western Precinct, The University of Melbourne, St. Albans, VIC, Australia
| | - Nicole Stupka
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, VIC, Australia
- Department of Medicine, Melbourne Medical School - Western Precinct, The University of Melbourne, St. Albans, VIC, Australia
| | - Gustavo Duque
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, VIC, Australia.
- Department of Medicine, Melbourne Medical School - Western Precinct, The University of Melbourne, St. Albans, VIC, Australia.
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35
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Kirk B, Al Saedi A, Duque G. Osteosarcopenia: A case of geroscience. Aging Med (Milton) 2019; 2:147-156. [PMID: 31942528 PMCID: PMC6880711 DOI: 10.1002/agm2.12080] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 08/19/2019] [Indexed: 12/12/2022] Open
Abstract
Many older persons lose their mobility and independence due to multiple diseases occurring simultaneously. Geroscience is aimed at developing innovative approaches to better identify relationships among the biological processes of aging. Osteoporosis and sarcopenia are two of the most prevalent chronic diseases in older people, with both conditions sharing overlapping risk factors and pathogenesis. When occurring together, these diseases form a geriatric syndrome termed "osteosarcopenia," which increases the risk of frailty, hospitalizations, and death. Findings from basic and clinical sciences aiming to understand osteosarcopenia have provided evidence of this syndrome as a case of geroscience. Genetic, endocrine, and mechanical stimuli, in addition to fat infiltration, sedentarism, and nutritional deficiencies, affect muscle and bone homeostasis to characterize this syndrome. However, research is in its infancy regarding accurate diagnostic markers and effective treatments with dual effects on muscle and bone. To date, resistance exercise remains the most promising strategy to increase muscle and bone mass, while sufficient quantities of protein, vitamin D, calcium, and creatine may preserve these tissues with aging. More recent findings, from rodent models, suggest treating ectopic fat in muscle and bone marrow as a possible avenue to curb osteosarcopenia, although this needs testing in human clinical trials.
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Affiliation(s)
- Ben Kirk
- Department of MedicineWestern HealthMelbourne Medical SchoolUniversity of MelbourneMelbourneVic.Australia
- Australian Institute for Musculoskeletal Science (AIMSS)University of Melbourne and Western HealthMelbourneVic.Australia
| | - Ahmed Al Saedi
- Department of MedicineWestern HealthMelbourne Medical SchoolUniversity of MelbourneMelbourneVic.Australia
- Australian Institute for Musculoskeletal Science (AIMSS)University of Melbourne and Western HealthMelbourneVic.Australia
| | - Gustavo Duque
- Department of MedicineWestern HealthMelbourne Medical SchoolUniversity of MelbourneMelbourneVic.Australia
- Australian Institute for Musculoskeletal Science (AIMSS)University of Melbourne and Western HealthMelbourneVic.Australia
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