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Peng H, Jenkins ZA, White R, Connors S, Hunter MF, Ronan A, Zankl A, Markie DM, Daniel PB, Robertson SP. An Activating Variant in CTNNB1 is Associated with a Sclerosing Bone Dysplasia and Adrenocortical Neoplasia. J Clin Endocrinol Metab 2020; 105:5714342. [PMID: 31970420 DOI: 10.1210/clinem/dgaa034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 01/20/2020] [Indexed: 12/13/2022]
Abstract
CONTEXT The WNT/β-catenin pathway is central to the pathogenesis of various human diseases including those affecting bone development and tumor progression. OBJECTIVE To evaluate the role of a gain-of-function variant in CTNNB1 in a child with a sclerosing bone dysplasia and an adrenocortical adenoma. DESIGN Whole exome sequencing with corroborative biochemical analyses. PATIENTS We recruited a child with a sclerosing bone dysplasia and an adrenocortical adenoma together with her unaffected parents. INTERVENTION Whole exome sequencing and performance of immunoblotting and luciferase-based assays to assess the cellular consequences of a de novo variant in CTNNB1. MAIN OUTCOME MEASURE(S)/RESULT A de novo variant in CTNNB1 (c.131C>T; p.[Pro44Leu]) was identified in a patient with a sclerosing bone dysplasia and an adrenocortical adenoma. A luciferase-based transcriptional assay of WNT signaling activity verified that the activity of β-catenin was increased in the cells transfected with a CTNNB1p.Pro44Leu construct (P = 4.00 × 10-5). The β-catenin p.Pro44Leu variant was also associated with a decrease in phosphorylation at Ser45 and Ser33/Ser37/Thr41 in comparison to a wild-type (WT) CTNNB1 construct (P = 2.16 × 10-3, P = 9.34 × 10-8 respectively). CONCLUSION Increased β-catenin activity associated with a de novo gain-of-function CTNNB1 variant is associated with osteosclerotic phenotype and adrenocortical neoplasia.
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Affiliation(s)
- Hui Peng
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, Hunan, China
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Zandra A Jenkins
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Ruby White
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Sam Connors
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Matthew F Hunter
- Monash Genetics, Monash Medical Centre, Melbourne, Victoria, Australia
- Department of Paediatrics, Monash University, Melbourne, Victoria, Australia
| | - Anne Ronan
- Hunter Genetics, Newcastle, New South Wales, Australia
| | - Andreas Zankl
- Department of Clinical Genetics, The Children's Hospital at Westmead, Sydney, New South Wales, Australia
- Discipline of Genomic Medicine, Sydney Medical School, The University of Sydney, Camperdown, New South Wales, Australia
- Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - David M Markie
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin 9016, New Zealand
| | - Philip B Daniel
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Stephen P Robertson
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
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Yang M, Guo Q, Peng H, Xiao YZ, Xiao Y, Huang Y, Li CJ, Su T, Zhang YL, Lei MX, Chen HL, Jiang TJ, Luo XH. Krüppel-like factor 3 inhibition by mutated lncRNA Reg1cp results in human high bone mass syndrome. J Exp Med 2019; 216:1944-1964. [PMID: 31196982 PMCID: PMC6683986 DOI: 10.1084/jem.20181554] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 02/27/2019] [Accepted: 05/16/2019] [Indexed: 12/11/2022] Open
Abstract
The authors report a mutation in the long noncoding RNA Reg1cp that induces osteogenesis via vascular induction in humans. This mutation affects angiogenesis by blocking Klf3’s repressing activity. The Klf3 antagonist Ophiopogonin D could promote CD31hiEmcnhi vessel formation and osteogenesis in osteoporosis mice. High bone mass (HBM) is usually caused by gene mutations, and its mechanism remains unclear. In the present study, we identified a novel mutation in the long noncoding RNA Reg1cp that is associated with HBM. Subsequent analysis in 1,465 Chinese subjects revealed that heterozygous Reg1cp individuals had higher bone density compared with subjects with WT Reg1cp. Mutant Reg1cp increased the formation of the CD31hiEmcnhi endothelium in the bone marrow, which stimulated angiogenesis during osteogenesis. Mechanistically, mutant Reg1cp directly binds to Krüppel-like factor 3 (KLF3) to inhibit its activity. Mice depleted of Klf3 in endothelial cells showed a high abundance of CD31hiEmcnhi vessels and increased bone mass. Notably, we identified a natural compound, Ophiopogonin D, which functions as a KLF3 inhibitor. Administration of Ophiopogonin D increased the abundance of CD31hiEmcnhi vessels and bone formation. Our findings revealed a specific mutation in lncRNA Reg1cp that is involved in the pathogenesis of HBM and provides a new target to treat osteoporosis.
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Affiliation(s)
- Mi Yang
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, China
| | - Qi Guo
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, China.,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
| | - Hui Peng
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, China
| | - Yu-Zhong Xiao
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, China.,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
| | - Ye Xiao
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, China
| | - Yan Huang
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, China
| | - Chang-Jun Li
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, China
| | - Tian Su
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, China
| | - Yun-Lin Zhang
- Department of Metabolic Endocrinology, The Second People's Hospital of Xiangxiang, Xiangxiang, China
| | - Min-Xiang Lei
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, China
| | - Hui-Ling Chen
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, China
| | - Tie-Jian Jiang
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, China
| | - Xiang-Hang Luo
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, China
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Affiliation(s)
- Allen W. Root
- Department of Pediatrics, Johns Hopkins Medicine – All Children’s Hospital, St. Petersburg, FL, USA
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Terry N, Margolis KG. Serotonergic Mechanisms Regulating the GI Tract: Experimental Evidence and Therapeutic Relevance. Handb Exp Pharmacol 2016; 239:319-342. [PMID: 28035530 DOI: 10.1007/164_2016_103] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Serotonin (5-hydroxytryptamine; 5-HT) is best known as a neurotransmitter critical for central nervous system (CNS) development and function. 95% of the body's serotonin, however, is produced in the intestine where it has been increasingly recognized for its hormonal, autocrine, paracrine, and endocrine actions. This chapter provides the most current knowledge of the critical autocrine and paracrine roles of 5-HT in intestinal motility and inflammation as well as its function as a hormone in osteocyte homeostasis. Therapeutic applications in each of these areas are also discussed.
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Affiliation(s)
- Natalie Terry
- Division of Pediatric Gastroenterology, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Kara Gross Margolis
- Division of Pediatric Gastroenterology, Department of Pediatrics, Morgan Stanley Children's Hospital, Columbia University Medical Center, New York, NY, USA.
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Buenzli PR, Sims NA. Quantifying the osteocyte network in the human skeleton. Bone 2015; 75:144-50. [PMID: 25708054 DOI: 10.1016/j.bone.2015.02.016] [Citation(s) in RCA: 171] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 01/25/2015] [Accepted: 02/10/2015] [Indexed: 11/26/2022]
Abstract
Osteocytes form an extensive cellular network throughout the hard tissue matrix of the skeleton, which is known to regulate skeletal structure. However due to limitations in imaging techniques, the magnitude and complexity of this network remain undefined. We have used data from recent papers obtained by new imaging techniques, in order to estimate absolute and relative quantities of the human osteocyte network and form a more complete understanding of the extent and nature of this network. We estimate that the total number of osteocytes within the average adult human skeleton is ~42 billion and that the total number of osteocyte dendritic projections from these cells is ~3.7 trillion. Based on prior measurements of canalicular density and a mathematical model of osteocyte dendritic process branching, we calculate that these cells form a total of 23 trillion connections with each other and with bone surface cells. We estimate the total length of all osteocytic processes connected end-to-end to be 175,000 km. Furthermore, we calculate that the total surface area of the lacuno-canalicular system is 215 m(2). However, the residing osteocytes leave only enough space for 24 mL of extracellular fluid. Calculations based on measurements in lactation-induced murine osteocytic osteolysis indicate a potential total loss of ~16,000 mm(3) (16 mL) of bone by this process in the human skeleton. Finally, based on the average speed of remodelling in the adult, we calculate that 9.1 million osteocytes are replenished throughout the skeleton on a daily basis, indicating the dynamic nature of the osteocyte network. We conclude that the osteocyte network is a highly complex communication network, and is much more vast than commonly appreciated. It is at the same order of magnitude as current estimates of the size of the neural network in the brain, even though the formation of the branched network differs between neurons and osteocytes. Furthermore, continual replenishment of large numbers of osteocytes in the process of remodelling allows therapeutic changes to the continually renewed osteoblast population to be rapidly incorporated into the skeleton.
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Affiliation(s)
- Pascal R Buenzli
- School of Mathematical Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Natalie A Sims
- St Vincent's Institute of Medical Research, The University of Melbourne, Fitzroy, VIC 3065, Australia.
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Fu HJ, Zhou YR, Bao BH, Jia MX, Zhao Y, Zhang L, Li JX, He HL, Zhou XM. Tryptophan hydroxylase 1 (Tph-1)-targeted bone anabolic agents for osteoporosis. J Med Chem 2014; 57:4692-709. [PMID: 24844139 DOI: 10.1021/jm5002293] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Tryptophan hydroxylase 1 (Tph-1), the principal enzyme for peripheral serotonin biosynthesis, provides a novel target to design anabolic agents for osteoporosis. Here, we present a design, synthesis of a novel series of ursolic acid derivatives under the guidance of docking technique, and bioevaluation of the derivatives using RBL2H3 cells and ovariectomized (OVX) rats. Of the compounds, 9a showed a potent inhibitory activity on serotonin biosynthesis. Further investigations revealed that 9a, as an efficient Tph-1 binder identified by SPR (estimated KD: 6.82 μM), suppressed the protein and mRNA expressions of Tph-1 and lowered serotonin contents in serum and gut without influence on brain serotonin. Moreover, oral administration of 9a elevated serum level of N-terminal propeptide of procollagen type 1 (P1NP), a bone formation marker, and improved bone microarchitecture without estrogenic side effects in ovariectomized rats. Collectively, 9a may serve as a new candidate for bone anabolic drug discovery.
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Affiliation(s)
- Hai-Jian Fu
- State Key Lab of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University , 22 Hankou Road, Nanjing 210093, P. R. China
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LRP5 and bone mass regulation: Where are we now? BONEKEY REPORTS 2012; 1:1. [PMID: 23951413 DOI: 10.1038/bonekey.2012.1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Accepted: 09/23/2011] [Indexed: 12/13/2022]
Abstract
The discovery of causal mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) gene underlying conditions of altered bone mass ushered in a new era in bone research. Since those original publications, the role of Lrp5 and the Wnt/β-catenin signaling pathway controlled by Lrp5 and its homologs, Lrp6 and Lrp4, in bone mass regulation has been an intense area of investigation. Studies to date have implicated this pathway in skeletal development, osteoblast differentiation and proliferation, osteoblast/osteocyte apoptosis, regulation of the balance between osteogenesis-chondrogenesis-adipogenesis, regulation of osteoclastogenesis and the response of bone to mechanical loading. Interestingly, the data from knockout and transgenic mice involving Lrp4/5/6 and/or their regulators, as well as β-catenin signaling pathway components, and in vitro studies have sometimes yielded conflicting results. Adding to the complexity of the system are the studies that suggested Lrp5 regulated bone mass through a gut-bone endocrine signaling system involving Lrp5 mediated control of gut serotonin synthesis. However, recent studies have called this into question and so this provocative concept remains an open question. Clearly, the manipulation of Lrp5/Wnt/β-catenin pathway presents as a major target for drug development to treat diseases of low bone mass such as osteoporosis and these new therapies are in full progress. At present, although it is clear that Lrp5 has a role in bone mass regulation, much of the details remain to be elucidated and this is a major and exciting challenge for future studies.
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