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LaCombe JM, Sloan K, Thomas JR, Blackwell MP, Crawford I, Bishop F, Wallace JM, Roper RJ. Sex-specific trisomic Dyrk1a-related skeletal phenotypes during development in a Down syndrome model. Dis Model Mech 2024; 17:dmm050914. [PMID: 39136051 PMCID: PMC11449447 DOI: 10.1242/dmm.050914] [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: 05/28/2024] [Accepted: 08/04/2024] [Indexed: 08/21/2024] Open
Abstract
Skeletal insufficiency affects all individuals with Down syndrome (DS) or trisomy 21 and may alter bone strength throughout development due to a reduced period of bone formation and early attainment of peak bone mass compared to those in typically developing individuals. Appendicular skeletal deficits also appear in males before females with DS. In femurs of male Ts65Dn DS model mice, cortical deficits were pronounced throughout development, but trabecular deficits and Dyrk1a overexpression were transitory until postnatal day (P) 30, when there were persistent trabecular and cortical deficits and Dyrk1a was trending toward overexpression. Correction of DS-related skeletal deficits by a purported DYRK1A inhibitor or through genetic means beginning at P21 was not effective at P30, but germline normalization of Dyrk1a improved male bone structure by P36. Trabecular and cortical deficits in female Ts65Dn mice were evident at P30 but subsided by P36, typifying periodic developmental skeletal normalizations that progressed to more prominent bone deficiencies. Sex-dependent differences in skeletal deficits with a delayed impact of trisomic Dyrk1a are important to find temporally specific treatment periods for bone and other phenotypes associated with trisomy 21.
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Affiliation(s)
- Jonathan M LaCombe
- Department of Biology, Indiana University Indianapolis, Indianapolis, IN 46202, USA
- Labcorp Early Development Laboratories, Inc., Greenfield, IN 46140, USA
| | - Kourtney Sloan
- Department of Biology, Indiana University Indianapolis, Indianapolis, IN 46202, USA
| | - Jared R Thomas
- Department of Biology, Indiana University Indianapolis, Indianapolis, IN 46202, USA
| | - Matthew P Blackwell
- Department of Biology, Indiana University Indianapolis, Indianapolis, IN 46202, USA
| | - Isabella Crawford
- Department of Biology, Indiana University Indianapolis, Indianapolis, IN 46202, USA
| | - Flannery Bishop
- Department of Biology, Indiana University Indianapolis, Indianapolis, IN 46202, USA
| | - Joseph M Wallace
- Department of Biomedical Engineering, Purdue University, Indianapolis, IN 46202, USA
| | - Randall J Roper
- Department of Biology, Indiana University Indianapolis, Indianapolis, IN 46202, USA
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2
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McKean DM, Zhang Q, Narayan P, Morton SU, Strohmenger V, Tang VT, McAllister S, Sharma A, Quiat D, Reichart D, DeLaughter DM, Wakimoto H, Gorham JM, Brown K, McDonough B, Willcox JA, Jang MY, DePalma SR, Ward T, Kim R, Cleveland JD, Seidman J, Seidman CE. Increased endothelial sclerostin caused by elevated DSCAM mediates multiple trisomy 21 phenotypes. J Clin Invest 2024; 134:e167811. [PMID: 38828726 PMCID: PMC11142749 DOI: 10.1172/jci167811] [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: 12/06/2022] [Accepted: 04/11/2024] [Indexed: 06/05/2024] Open
Abstract
Trisomy 21 (T21), a recurrent aneuploidy occurring in 1:800 births, predisposes to congenital heart disease (CHD) and multiple extracardiac phenotypes. Despite a definitive genetic etiology, the mechanisms by which T21 perturbs development and homeostasis remain poorly understood. We compared the transcriptome of CHD tissues from 49 patients with T21 and 226 with euploid CHD (eCHD). We resolved cell lineages that misexpressed T21 transcripts by cardiac single-nucleus RNA sequencing and RNA in situ hybridization. Compared with eCHD samples, T21 samples had increased chr21 gene expression; 11-fold-greater levels (P = 1.2 × 10-8) of SOST (chr17), encoding the Wnt inhibitor sclerostin; and 1.4-fold-higher levels (P = 8.7 × 10-8) of the SOST transcriptional activator ZNF467 (chr7). Euploid and T21 cardiac endothelial cells coexpressed SOST and ZNF467; however, T21 endothelial cells expressed 6.9-fold more SOST than euploid endothelial cells (P = 2.7 × 10-27). Wnt pathway genes were downregulated in T21 endothelial cells. Expression of DSCAM, residing within the chr21 CHD critical region, correlated with SOST (P = 1.9 × 10-5) and ZNF467 (P = 2.9 × 10-4). Deletion of DSCAM from T21 endothelial cells derived from human induced pluripotent stem cells diminished sclerostin secretion. As Wnt signaling is critical for atrioventricular canal formation, bone health, and pulmonary vascular homeostasis, we concluded that T21-mediated increased sclerostin levels would inappropriately inhibit Wnt activities and promote Down syndrome phenotypes. These findings imply therapeutic potential for anti-sclerostin antibodies in T21.
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Affiliation(s)
- David M. McKean
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
- Cardiovascular Division, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Qi Zhang
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Priyanka Narayan
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
- Weill Cornell Medicine, New York, New York, USA
| | - Sarah U. Morton
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Viktoria Strohmenger
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
- Walter Brendle Centre of Experimental Medicine, University Hospital, Ludwig Maximilian University of Munich, Munich, Germany
| | - Vi T. Tang
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Sophie McAllister
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Ananya Sharma
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Daniel Quiat
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
- Department of Cardiology, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Daniel Reichart
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | | | - Hiroko Wakimoto
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Joshua M. Gorham
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Kemar Brown
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Barbara McDonough
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Jon A. Willcox
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Min Young Jang
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Steven R. DePalma
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
- Howard Hughes Medical Institute, Harvard University, Boston, Massachusetts, USA
| | - Tarsha Ward
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | | | - Richard Kim
- Section of Cardiothoracic Surgery, University of Southern California Keck School of Medicine, Los Angeles, California, USA
| | - John D. Cleveland
- Section of Cardiothoracic Surgery, University of Southern California Keck School of Medicine, Los Angeles, California, USA
| | - J.G. Seidman
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Christine E. Seidman
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
- Cardiovascular Division, Brigham and Women’s Hospital, Boston, Massachusetts, USA
- Howard Hughes Medical Institute, Harvard University, Boston, Massachusetts, USA
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3
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LaCombe JM, Sloan K, Thomas JR, Blackwell MP, Crawford I, Wallace JM, Roper RJ. Sex specific emergence of trisomic Dyrk1a-related skeletal phenotypes in the development of a Down syndrome mouse model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.24.595804. [PMID: 38826419 PMCID: PMC11142220 DOI: 10.1101/2024.05.24.595804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Skeletal insufficiency affects all individuals with Down syndrome (DS) or Trisomy 21 (Ts21) and may alter bone strength throughout development due to a reduced period of bone formation and early attainment of peak bone mass compared to typically developing individuals. Appendicular skeletal deficits also appear in males before females with DS. In femurs of male Ts65Dn DS model mice, cortical deficits were pronounced throughout development, but trabecular deficits and Dyrk1a overexpression were transitory until postnatal day (P) 30 when there were persistent trabecular and cortical deficits and Dyrk1a was trending overexpression. Correction of DS-related skeletal deficits by a purported DYRK1A inhibitor or through genetic means beginning at P21 was not effective at P30, but germline normalization of Dyrk1a improved male bone structure by P36. Trabecular and cortical deficits in female Ts65Dn mice were evident at P30 but subsided by P36, typifying periodic developmental skeletal normalizations that progressed to more prominent bone deficiencies. Sex-dependent differences in skeletal deficits with a delayed impact of trisomic Dyrk1a are important to find temporally specific treatment periods for bone and other phenotypes associated with Ts21.
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Affiliation(s)
- Jonathan M. LaCombe
- Department of Biology, Indiana University-Indianapolis, IN, USA
- Labcorp Early Development Laboratories, Inc., Greenfield, IN, USA
| | - Kourtney Sloan
- Department of Biology, Indiana University-Indianapolis, IN, USA
| | - Jared R. Thomas
- Department of Biology, Indiana University-Indianapolis, IN, USA
| | | | | | - Joseph M. Wallace
- Department of Biomedical Engineering, Purdue University, Indianapolis, IN, USA
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Xing Z, Li Y, Cortes-Gomez E, Jiang X, Gao S, Pao A, Shan J, Song Y, Perez A, Yu T, Highsmith MR, Boadu F, Conroy JM, Singh PK, Bakin AV, Cheng J, Duan Z, Wang J, Liu S, Tycko B, Yu YE. Dissection of a Down syndrome-associated trisomy to separate the gene dosage-dependent and -independent effects of an extra chromosome. Hum Mol Genet 2023; 32:2205-2218. [PMID: 37014740 PMCID: PMC10281752 DOI: 10.1093/hmg/ddad056] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 02/13/2023] [Accepted: 03/27/2023] [Indexed: 04/05/2023] Open
Abstract
As an aneuploidy, trisomy is associated with mammalian embryonic and postnatal abnormalities. Understanding the underlying mechanisms involved in mutant phenotypes is broadly important and may lead to new strategies to treat clinical manifestations in individuals with trisomies, such as trisomy 21 [Down syndrome (DS)]. Although increased gene dosage effects because of a trisomy may account for the mutant phenotypes, there is also the possibility that phenotypic consequences of a trisomy can arise because of the presence of a freely segregating extra chromosome with its own centromere, i.e. a 'free trisomy' independent of gene dosage effects. Presently, there are no reports of attempts to functionally separate these two types of effects in mammals. To fill this gap, here we describe a strategy that employed two new mouse models of DS, Ts65Dn;Df(17)2Yey/+ and Dp(16)1Yey/Df(16)8Yey. Both models carry triplications of the same 103 human chromosome 21 gene orthologs; however, only Ts65Dn;Df(17)2Yey/+ mice carry a free trisomy. Comparison of these models revealed the gene dosage-independent impacts of an extra chromosome at the phenotypic and molecular levels for the first time. They are reflected by impairments of Ts65Dn;Df(17)2Yey/+ males in T-maze tests when compared with Dp(16)1Yey/Df(16)8Yey males. Results from the transcriptomic analysis suggest the extra chromosome plays a major role in trisomy-associated expression alterations of disomic genes beyond gene dosage effects. This model system can now be used to deepen our mechanistic understanding of this common human aneuploidy and obtain new insights into the effects of free trisomies in other human diseases such as cancers.
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Affiliation(s)
- Zhuo Xing
- The Children’s Guild Foundation Down Syndrome Research Program, Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Yichen Li
- The Children’s Guild Foundation Down Syndrome Research Program, Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Eduardo Cortes-Gomez
- Department of Biostatistics and Bioinformatics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Xiaoling Jiang
- The Children’s Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang, China
| | - Shuang Gao
- Department of Biostatistics and Bioinformatics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
- Bioinformatics, OmniSeq Inc., Buffalo, NY, USA
| | - Annie Pao
- The Children’s Guild Foundation Down Syndrome Research Program, Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Jidong Shan
- Molecular Cytogenetics Core, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Yinghui Song
- Molecular Cytogenetics Core, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Amanda Perez
- Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Tao Yu
- The Children’s Guild Foundation Down Syndrome Research Program, Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Max R Highsmith
- Department of Electric Engineering and Computer Science, University of Missouri, Columbia, MO, USA
| | - Frimpong Boadu
- Department of Electric Engineering and Computer Science, University of Missouri, Columbia, MO, USA
| | - Jeffrey M Conroy
- Research and Development, OmniSeq Inc., Buffalo, NY, USA
- Research Support Services, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Prashant K Singh
- Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Andrei V Bakin
- Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Jianlin Cheng
- Department of Electric Engineering and Computer Science, University of Missouri, Columbia, MO, USA
| | - Zhijun Duan
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA
- Division of Hematology, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Jianmin Wang
- Department of Biostatistics and Bioinformatics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Song Liu
- Department of Biostatistics and Bioinformatics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
| | - Benjamin Tycko
- Hackensack-Meridian Health Center for Discovery and Innovation, Nutley, NJ, USA
- John Theurer Cancer Center, Hackensack University Medical Center, Hackensack, NJ, USA
| | - Y Eugene Yu
- The Children’s Guild Foundation Down Syndrome Research Program, Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA
- Genetics, Genomics and Bioinformatics Program, State University of New York at Buffalo, Buffalo, NY, USA
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5
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O'Donohue AK, Xiao Y, Lee LR, Schofield T, Cheng TL, Munns CF, Baldock PA, Schindeler A. Targeted postnatal knockout of Sclerostin using a bone-targeted adeno-associated viral vector increases bone anabolism and decreases canalicular density. Bone 2023; 167:116636. [PMID: 36462771 DOI: 10.1016/j.bone.2022.116636] [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: 06/06/2022] [Revised: 11/27/2022] [Accepted: 11/28/2022] [Indexed: 12/02/2022]
Abstract
PURPOSE The creation of murine gene knockout models to study bone gene functions often requires the resource intensive crossbreeding of Cre transgenic and gene-floxed strains. The developmental versus postnatal roles of genes can be difficult to discern in such models. For example, embryonic deletion of the Sclerostin (Sost) gene establishes a high-bone mass phenotype in neonatal mice that may impact on future bone growth. To generate a postnatal skeletal knockout of Sost in adult mice, this study used a single injection of a bone-targeted recombinant adeno-associated virus (rAAV) vector. METHODS 8-week-old Sostflox/flox mice were injected with saline (control) or a single injection containing 5 × 1011 vg AAV8-Sp7-Cre vector. Ai9 fluorescent Cre reporter mice were dosed in parallel to confirm targeting efficiency. After 6 weeks, detailed bone analysis was performed via microCT, biomechanical testing, and bone histology on vertebral and long bone specimens. RESULTS The AAV8-Sp7-Cre vector induced widespread persistent recombination in the bone compartment. Regional microCT analyses revealed significant increases in bone with vector treatment. In the L3 vertebrae, Sostflox/flox:AAV-Cre showed a 22 % increase in bone volume and 21 % in trabecular bone fraction compared to controls; this translated to a 17 % increase in compressive strength. In the tibiae, Sostflox/flox:AAV-Cre led to small but statistically significant increases in cortical bone volume and thickness. These were consistent with a 25 % increase in mineral apposition rate, but this did not translate into increased four-point bending strength. Ploton silver nitrate stain on histological sections revealed an unexpected increase in canalicular density associated with Sost ablation. CONCLUSION This report demonstrates a proof-of-concept that the AAV8-Sp7-Cre vector can efficiently produce postnatal skeletal knockout mice using gene-floxed strains. This technology has the potential for broad utility in the bone field with existing conditional lines. These data also confirm an important postnatal role for Sost in regulating bone homeostasis, consistent with prior studies using neutralizing Sclerostin antibodies, and highlights a novel role of Sost in canalicular remodeling.
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Affiliation(s)
- Alexandra K O'Donohue
- Bioengineering & Molecular Medicine Laboratory, The Children's Hospital at Westmead and the Westmead Institute for Medical Research, Westmead, NSW, Australia; The Children's Hospital at Westmead Clinical School, The University of Sydney, Camperdown, NSW, Australia
| | - Ya Xiao
- Bone Division, Garvan Institute for Medical Research, Darlinghurst, NSW, Australia
| | - Lucinda R Lee
- Bioengineering & Molecular Medicine Laboratory, The Children's Hospital at Westmead and the Westmead Institute for Medical Research, Westmead, NSW, Australia; The Children's Hospital at Westmead Clinical School, The University of Sydney, Camperdown, NSW, Australia
| | - Timothy Schofield
- Bioengineering & Molecular Medicine Laboratory, The Children's Hospital at Westmead and the Westmead Institute for Medical Research, Westmead, NSW, Australia; The Children's Hospital at Westmead Clinical School, The University of Sydney, Camperdown, NSW, Australia
| | - Tegan L Cheng
- University of Sydney School of Health Sciences, University of Sydney, Camperdown, NSW, Australia; Engineering Prototypes & Implants for Children (EPIC) Lab, The Children's Hospital at Westmead, Sydney, NSW, Australia
| | - Craig F Munns
- Department of Endocrinology and Diabetes, Queensland Children's Hospital, Brisbane, QLD, Australia; Child Health Research Centre and Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Paul A Baldock
- Bone Division, Garvan Institute for Medical Research, Darlinghurst, NSW, Australia
| | - Aaron Schindeler
- Bioengineering & Molecular Medicine Laboratory, The Children's Hospital at Westmead and the Westmead Institute for Medical Research, Westmead, NSW, Australia; The Children's Hospital at Westmead Clinical School, The University of Sydney, Camperdown, NSW, Australia.
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6
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Sherman KM, Williams DK, Welsh CA, Cooper AM, Falck A, Huggins S, Bokhari RS, Gaddy D, McKelvey KD, Dawson LA, Suva LJ. Low bone mass and impaired fracture healing in mouse models of Trisomy21 (Down syndrome). Bone 2022; 162:116471. [PMID: 35716916 PMCID: PMC9356441 DOI: 10.1016/j.bone.2022.116471] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/01/2022] [Accepted: 06/09/2022] [Indexed: 11/16/2022]
Abstract
Individuals with Down syndrome (DS), the result of trisomy of human chromosome Hsa21 (Ts21), present with an array of skeletal abnormalities typified by altered craniofacial features, short stature and low bone mineral density (BMD). While bone deficits progress with age in both sexes, low bone mass is more pronounced in DS men than women and osteopenia appears earlier. In the current study, the reproductive hormone status (FSH, LH, testosterone) of 17 DS patients (males, ages range 19-52 years) was measured. Although testosterone was consistently low, the hypothalamic-pituitary-gonadal axis was intact with corresponding rises in FSH and LH. To provide further insight into the heterogeneity of the bone mass in DS, the skeletal phenotypes of three of the most used murine DS models, Ts65Dn (Ts65), TC1, and Dp16(Yey1) (Dp16) were characterized and contrasted. Evaluation of the bone phenotype of both male and female 3-month-old Dp16 mice demonstrated sexual dimorphism, with low bone mass apparent in males, as it is in Ts65, but not in female Dp16. In contrast, male TC1 mice had no apparent bone phenotype. To determine whether low bone mass in DS impacted fracture healing, fractures of the middle phalanx (P2) digits were generated in both male and female Dp16 mice at 15 weeks of age, an age where the sexually dimorphic low BMD persisted. Fracture healing was assessed via in vivo microCT over (13 weeks) 93 days post fracture (DPF). At 93 DPF, 0 % of DS male (n = 12) or female (n = 8) fractures healed, compared to 50 % of the male (n = 28) or female (n = 8) WT littermate fractures. MicroCT revealed periosteal unbridged mineralized callus formation across the fracture gap in Dp16 mice, which was confirmed by subsequent histology. These studies provide the first direct evidence of significantly impaired fracture healing in the setting of DS.
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Affiliation(s)
- Kirby M Sherman
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, United States of America
| | - Diarra K Williams
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, United States of America
| | - Casey A Welsh
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, United States of America
| | - Alexis M Cooper
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, United States of America
| | - Alyssa Falck
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, United States of America
| | - Shannon Huggins
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, United States of America
| | - Rihana S Bokhari
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, United States of America
| | - Dana Gaddy
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, United States of America
| | - Kent D McKelvey
- Department of Family Medicine, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States of America; Department of Medical Genetics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States of America
| | - Lindsay A Dawson
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, United States of America
| | - Larry J Suva
- Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, United States of America.
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7
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Thomas JR, Sloan K, Cave K, Wallace JM, Roper RJ. Skeletal Deficits in Male and Female down Syndrome Model Mice Arise Independent of Normalized Dyrk1a Expression in Osteoblasts. Genes (Basel) 2021; 12:1729. [PMID: 34828335 PMCID: PMC8624983 DOI: 10.3390/genes12111729] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 01/11/2023] Open
Abstract
Trisomy 21 (Ts21) causes alterations in skeletal development resulting in decreased bone mass, shortened stature and weaker bones in individuals with Down syndrome (DS). There is a sexual dimorphism in bone mineral density (BMD) deficits associated with DS with males displaying earlier deficits than females. The relationships between causative trisomic genes, cellular mechanisms, and influence of sex in DS skeletal abnormalities remain unknown. One hypothesis is that the low bone turnover phenotype observed in DS results from attenuated osteoblast function, contributing to impaired trabecular architecture, altered cortical geometry, and decreased mineralization. DYRK1A, found in three copies in humans with DS, Ts65Dn, and Dp1Tyb DS model mice, has been implicated in the development of postnatal skeletal phenotypes associated with DS. Reduced copy number of Dyrk1a to euploid levels from conception in an otherwise trisomic Ts65Dn mice resulted in a rescue of appendicular bone deficits, suggesting DYRK1A contributes to skeletal development and homeostasis. We hypothesized that reduction of Dyrk1a copy number in trisomic osteoblasts would improve cellular function and resultant skeletal structural anomalies in trisomic mice. Female mice with a floxed Dyrk1a gene (Ts65Dn,Dyrk1afl/wt) were mated with male Osx-Cre+ (expressed in osteoblasts beginning around E13.5) mice, resulting in reduced Dyrk1a copy number in mature osteoblasts in Ts65Dn,Dyrk1a+/+/Osx-Cre P42 male and female trisomic and euploid mice, compared with littermate controls. Male and female Ts65Dn,Dyrk1a+/+/+ (3 copies of DYRK1A in osteoblasts) and Ts65Dn,Dyrk1a+/+/Osx-Cre (2 copies of Dyrk1a in osteoblasts) displayed similar defects in both trabecular architecture and cortical geometry, with no improvements with reduced Dyrk1a in osteoblasts. This suggests that trisomic DYRK1A does not affect osteoblast function in a cell-autonomous manner at or before P42. Although male Dp1Tyb and Ts65Dn mice exhibit similar skeletal deficits at P42 in both trabecular and cortical bone compartments between euploid and trisomic mice, female Ts65Dn mice exhibit significant cortical and trabecular deficits at P42, in contrast to an absence of genotype effect in female Dp1Tyb mice in trabecular bone. Taken together, these data suggest skeletal deficits in DS mouse models and are sex and age dependent, and influenced by strain effects, but are not solely caused by the overexpression of Dyrk1a in osteoblasts. Identifying molecular and cellular mechanisms, disrupted by gene dosage imbalance, that are involved in the development of skeletal phenotypes associated with DS could help to design therapies to rescue skeletal deficiencies seen in DS.
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Affiliation(s)
- Jared R. Thomas
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA; (J.R.T.); (K.S.); (K.C.)
| | - Kourtney Sloan
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA; (J.R.T.); (K.S.); (K.C.)
| | - Kelsey Cave
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA; (J.R.T.); (K.S.); (K.C.)
| | - Joseph M. Wallace
- Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA;
| | - Randall J. Roper
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA; (J.R.T.); (K.S.); (K.C.)
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8
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Sclerostin Depletion Induces Inflammation in the Bone Marrow of Mice. Int J Mol Sci 2021; 22:ijms22179111. [PMID: 34502021 PMCID: PMC8431516 DOI: 10.3390/ijms22179111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/18/2021] [Accepted: 08/20/2021] [Indexed: 01/25/2023] Open
Abstract
Romosozumab, a humanized monoclonal antibody specific for sclerostin (SOST), has been approved for treatment of postmenopausal women with osteoporosis at a high risk for fracture. Previous work in sclerostin global knockout (Sost-/-) mice indicated alterations in immune cell development in the bone marrow (BM), which could be a possible side effect in romosozumab-treated patients. Here, we examined the effects of short-term sclerostin depletion in the BM on hematopoiesis in young mice receiving sclerostin antibody (Scl-Ab) treatment for 6 weeks, and the effects of long-term Sost deficiency on wild-type (WT) long-term hematopoietic stem cells transplanted into older cohorts of Sost-/- mice. Our analyses revealed an increased frequency of granulocytes in the BM of Scl-Ab-treated mice and WT→Sost-/- chimeras, indicating myeloid-biased differentiation in Sost-deficient BM microenvironments. This myeloid bias extended to extramedullary hematopoiesis in the spleen and was correlated with an increase in inflammatory cytokines TNFα, IL-1α, and MCP-1 in Sost-/- BM serum. Additionally, we observed alterations in erythrocyte differentiation in the BM and spleen of Sost-/- mice. Taken together, our current study indicates novel roles for Sost in the regulation of myelopoiesis and control of inflammation in the BM.
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Abstract
PURPOSE Down syndrome (DS) is caused by trisomy 21 (Ts21) and results in skeletal deficits including shortened stature, low bone mineral density, and a predisposition to early onset osteoporosis. Ts21 causes significant alterations in skeletal development, morphology of the appendicular skeleton, bone homeostasis, age-related bone loss, and bone strength. However, the genetic or cellular origins of DS skeletal phenotypes remain unclear. RECENT FINDINGS New studies reveal a sexual dimorphism in characteristics and onset of skeletal deficits that differ between DS and typically developing individuals. Age-related bone loss occurs earlier in the DS as compared to general population. Perturbations of DS skeletal quality arise from alterations in cellular and molecular pathways affected by the overexpression of trisomic genes. Sex-specific alterations occur in critical developmental pathways that disrupt bone accrual, remodeling, and homeostasis and are compounded by aging, resulting in increased risks for osteopenia, osteoporosis, and fracture in individuals with DS.
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Affiliation(s)
- Jared R Thomas
- Department of Biology, Indiana University-Purdue University Indianapolis, 723 West Michigan Street, SL 306, Indianapolis, IN, 46202-3275, USA
| | - Randall J Roper
- Department of Biology, Indiana University-Purdue University Indianapolis, 723 West Michigan Street, SL 306, Indianapolis, IN, 46202-3275, USA.
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Osumi R, Wang Z, Ishihara Y, Odagaki N, Iimura T, Kamioka H. Changes in the intra- and peri-cellular sclerostin distribution in lacuno-canalicular system induced by mechanical unloading. J Bone Miner Metab 2021; 39:148-159. [PMID: 32844318 DOI: 10.1007/s00774-020-01135-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 07/26/2020] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Mechanical stimuli regulate Sclerostin (Scl), a negative regulator of bone formation, expression in osteocytes. However, the detailed Scl distribution in osteocytes in response to mechanical unloading remains unclear. MATERIALS AND METHODS Twelve-week-old male rats were used. The sciatic and femoral nerves on the right side were excised as mechanical unloading treatment. A sham operation was performed on the left side. One week after neurotrauma, the bone density of the femora was evaluated by peripheral quantitative computed tomography, and immunofluorescence was performed in coronal sections of the femoral diaphysis. The mean fluorescence intensity and fluorescent profile of Scl from the marrow to the periosteal side were analyzed to estimate the Scl expression and determine to which side (marrow or periosteal) the Scl prefers to distribute in response to mechanical unloading. The most sensitive region indicated by the immunofluorescence results was further investigated by transmission electron microscopy (TEM) with immunogold staining to show the Scl expression changes in different subcellular structures. RESULTS In femur distal metaphysis, neurotrauma-induced mechanical unloading significantly decreased the bone density, made the distribution of Scl closer to the marrow on the anterior and medial side, and increased the Scl expression only on the lateral side. TEM findings showed that only the expression of Scl in canaliculi was increased by mechanical unloading. CONCLUSIONS Our results showed that even short-term mechanical unloading is enough to decrease bone density, and mechanical unloading not only regulated the Scl expression but also changed the Scl distribution in both the osteocyte network and subcellular structures.
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Affiliation(s)
- Ryuta Osumi
- Department of Orthodontics, Okayama University Hospital, Okayama, Japan
| | - Ziyi Wang
- Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, Okayama, 700-8558, Japan
- Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | | | - Naoya Odagaki
- Department of Orthodontics, Okayama University Hospital, Okayama, Japan
| | - Tadahiro Iimura
- Department of Pharmacology, Graduate School of Dental Medicine, Hokkaido University, Hokkaido, Japan
| | - Hiroshi Kamioka
- Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, Okayama, 700-8558, Japan.
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LaCombe JM, Roper RJ. Skeletal dynamics of Down syndrome: A developing perspective. Bone 2020; 133:115215. [PMID: 31887437 PMCID: PMC7044033 DOI: 10.1016/j.bone.2019.115215] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 12/05/2019] [Accepted: 12/24/2019] [Indexed: 01/14/2023]
Abstract
Individuals with Down syndrome (DS) display distinctive skeletal morphology compared to the general population, but disparate descriptions, methodologies, analyses, and populations sampled have led to diverging conclusions about this unique skeletal phenotype. As individuals with DS are living longer, they may be at a higher risk of aging disorders such as osteoporosis and increased fracture risk. Sexual dimorphism has been suggested between males and females with DS in which males, not females, experience an earlier decline in bone mineral density (BMD). Unfortunately, studies focusing on skeletal health related to Trisomy 21 (Ts21) are few in number and often too underpowered to answer questions about skeletal development, resultant osteoporosis, and sexual dimorphism, especially in stages of bone accrual. Further confounding the field are the varied methods of bone imaging, analysis, and data interpretation. This review takes a critical look at the current knowledge of DS skeletal phenotypes, both from human and mouse studies, and presents knowledge gaps that need to be addressed, differences in research methodologies and analyses that affect the interpretation of results, and proposes guidelines for overcoming obstacles to understand skeletal traits associated with DS. By examining our current knowledge of bone in individuals with Ts21, a trajectory for future studies may be established to provide meaningful solutions for understanding the development of and improving skeletal structures in individuals with and without DS.
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Affiliation(s)
- Jonathan M LaCombe
- Department of Biology, Indiana University-Purdue University Indianapolis, United States of America
| | - Randall J Roper
- Department of Biology, Indiana University-Purdue University Indianapolis, United States of America.
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Zhang ZH, Jia XY, Fang JY, Chai H, Huang Q, She C, Jia P, Geng DC, Xu W. Reduction of SOST gene promotes bone formation through the Wnt/β-catenin signalling pathway and compensates particle-induced osteolysis. J Cell Mol Med 2020; 24:4233-4244. [PMID: 32134561 PMCID: PMC7171346 DOI: 10.1111/jcmm.15084] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 01/14/2020] [Accepted: 01/29/2020] [Indexed: 12/16/2022] Open
Abstract
The increase in bone resorption and/or the inhibition of bone regeneration caused by wear particles are the main causes of periprosthetic osteolysis. The SOST gene and Sclerostin, a protein synthesized by the SOST gene, are the characteristic marker of osteocytes and regulate bone formation and resorption. We aimed to verify whether the SOST gene was involved in osteolysis induced by titanium (Ti) particles and to investigate the effects of SOST reduction on osteolysis. The results showed osteolysis on the skull surface with an increase of sclerostin levels after treated with Ti particles. Similarly, sclerostin expression in MLO-Y4 osteocytes increased when treated with Ti particles in vitro. After reduction of SOST, local bone mineral density and bone volume increased, while number of lytic pores on the skull surface decreased and the erodibility of the skull surface was compensated. Histological analyses revealed that SOST reduction increased significantly alkaline phosphatase- (ALP) and osterix-positive expression on the skull surface which promoted bone formation. ALP activity and mineralization of MC3T3-E1 cells also increased in vitro when SOST was silenced, even if treated with Ti particles. In addition, Ti particles decreased β-catenin expression with an increase in sclerostin levels, in vivo and in vitro. Inversely, reduction of SOST expression increased β-catenin expression. In summary, our results suggested that reduction of SOST gene can activate the Wnt/β-catenin signalling pathway, promoting bone formation and compensated for bone loss induced by Ti particles. Thus, this study provided new perspectives in understanding the mechanisms of periprosthetic osteolysis.
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Affiliation(s)
- Zai Hang Zhang
- Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Xin Yu Jia
- Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Jing Yi Fang
- The Experiment Center, The Medical College of Soochow University, Suzhou, China
| | - Hao Chai
- Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Qun Huang
- Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou, China.,Department of Orthopedics, The Affiliated Zhangjiagang Hospital of Soochow University, Suzhou, China
| | - Chang She
- Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Peng Jia
- Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - De Chun Geng
- Department of Orthopedics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Wei Xu
- Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou, China
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Surowiec RK, Battle LF, Ward FS, Schlecht SH, Khoury BM, Robbins C, Wojtys EM, Caird MS, Kozloff KM. A xenograft model to evaluate the bone forming effects of sclerostin antibody in human bone derived from pediatric osteogenesis imperfecta patients. Bone 2020; 130:115118. [PMID: 31678490 PMCID: PMC6918492 DOI: 10.1016/j.bone.2019.115118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 10/01/2019] [Accepted: 10/21/2019] [Indexed: 12/18/2022]
Abstract
Osteogenesis imperfecta (OI) is a rare and severe skeletal dysplasia marked by low bone mass and poor bone quality which is especially burdensome during childhood. Since clinical trials for pediatric OI are difficult, there is a widespread reliance on genetically modified murine models to understand the skeletal effects of emerging therapeutics. However a common model does not yet exist to understand how patient-specific genotype may influence treatment efficacy. Recently, sclerostin antibody (SclAb) has been introduced as a novel putative anabolic therapy for diseases of low bone mass, but effects in pediatric patients remain unexplored. In this study, we aim to establish a direct xenograft approach using OI patient-derived bone isolates which retain patient-specific genetic defects and cells residing in their intrinsic extracellular environment to evaluate the bone-forming effects of SclAb as a bridge to clinical trials. OI and age matched non-OI patient bone typically discarded as surgical waste during corrective orthopaedic procedures were collected, trimmed and implanted subcutaneously (s.c.) on the dorsal surface of 4-6-week athymic mice. A subset of implanted mice were evaluated at short (1 week), intermediate (4 week), and long-term (12 week) durations to assess bone cell survival and presence of donor bone cells in order to determine an appropriate treatment duration. Remaining implanted mice were randomly assigned to a two or four-week SclAb-treated (25mg/kg s.c. 2QW) or untreated control group. Immunohistochemistry determined osteocyte and osteoblast donor/host relationship, TRAP staining quantified osteoclast activity, and TUNEL assay was used to understand rates of bone cell apoptosis at each implantation timepoint. Longitudinal changes of in vivo μCT outcomes and dynamic histomorphometry were used to assess treatment response and ex vivo μCT and dynamic histomorphometry of host femora served as a positive internal control to confirm a bone forming response to SclAb. Human-derived osteocytes and lining cells were present up to 12 weeks post-implantation with nominal cell apoptosis in the implant. Sclerostin expression remained donor-derived throughout the study. Osterix expression was primarily donor-derived in treated implants and shifted in favor of the host when implants remained untreated. μCT measures of BMD, TMD, BV/TV and BV increased with treatment but response was variable and impacted by bone implant morphology (trabecular, cortical) which was corroborated by histomorphometry. There was no statistical difference between treated and untreated osteoclast number in the implants. Host femora confirmed a systemic bone forming effect of SclAb. Findings support use of the xenograft model using solid bone isolates to explore the effects of novel bone-targeted therapies. These findings will impact our understanding of SclAb therapy in pediatric OI tissue through establishing the efficacy of this treatment in human cells prior to extension to the clinic.
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Affiliation(s)
- Rachel K Surowiec
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Lauren F Battle
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Ferrous S Ward
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Stephen H Schlecht
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA; Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Basma M Khoury
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Christopher Robbins
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Edward M Wojtys
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Michelle S Caird
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Kenneth M Kozloff
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.
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