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Heidari A, Homaei A, Saffari F. Novel Homozygous Nonsense Mutation in the LRP5 Gene in Two Siblings with Osteoporosis-pseudoglioma Syndrome. J Clin Res Pediatr Endocrinol 2023; 15:318-323. [PMID: 34965700 PMCID: PMC10448547 DOI: 10.4274/jcrpe.galenos.2021.2021.0186] [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: 07/11/2021] [Accepted: 11/25/2021] [Indexed: 12/01/2022] Open
Abstract
Osteoporosis-pseudoglioma syndrome (OPPG) is a rare autosomal recessive disorder characterized by severe osteoporosis and eye abnormalities that lead to vision loss. In this study, clinical findings and genetic study of two siblings with OPPG are presented. Whole exome sequencing of DNA enriched for exonic regions was performed with SureSelect 38Mbp all exon kit v. 7.0. The two siblings presented with different clinical manifestations of OPPG. The younger female sibling had blindness and severe osteoporosis with multiple fractures, while her older brother was also blind but with less severe osteoporosis and no fractures. On analysis, a novel homozygous nonsense mutation (c.351G>A) in exon 2 of LRP5 (NM_002335) was found, predicted to change a tryptophan at 117 to a stop codon (p. Trp117Ter). Thus, a variable phenotype was associated with an identical variant in these two siblings. The novel mutation reported herein expands the spectrum of the underlying genetic pathology of OPPG.
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Affiliation(s)
- Abolfazl Heidari
- Reference Laboratory of Qazvin Medical University, Iran Sana Medical Genetics Laboratory, Qazvin, Iran
| | - Ali Homaei
- Shahid Beheshti University of Medical Sciences, Department of General Surgery, Tehran, Iran
| | - Fatemeh Saffari
- Qazvin University of Medical Sciences, Children Growth Research Center, Research Institute for Prevention of Non-Communicable Diseases, Department of Pediatric Endocrinology, Qazvin, Iran
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Dai Z, Xu W, Ding R, Peng X, Shen X, Song J, Du P, Wang Z, Liu Y. Two-sample Mendelian randomization analysis evaluates causal associations between inflammatory bowel disease and osteoporosis. Front Public Health 2023; 11:1151837. [PMID: 37304119 PMCID: PMC10250718 DOI: 10.3389/fpubh.2023.1151837] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 05/15/2023] [Indexed: 06/13/2023] Open
Abstract
Introduction Over the past few years, multiple observational studies have speculated a potential association between inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD), and osteoporosis. However, no consensus has been reached regarding their interdependence and pathogenesis. Herein, we sought to further explore the causal associations between them. Methods We validated the association between IBD and reduced bone mineral density in humans based on genome-wide association studies (GWAS) data. To investigate the causal relationship between IBD and osteoporosis, we performed a two-sample Mendelian randomization study using training and validation sets. Genetic variation data for IBD, CD, UC, and osteoporosis were derived from published genome-wide association studies in individuals of European ancestry. After a series of robust quality control steps, we included eligible instrumental variables (SNPs) significantly associated with exposure (IBD/CD/UC). We adopted five algorithms, including MR Egger, Weighted median, Inverse variance weighted, Simple mode, and Weighted mode, to infer the causal association between IBD and osteoporosis. In addition, we evaluated the robustness of Mendelian randomization analysis by heterogeneity test, pleiotropy test, leave-one-out sensitivity test, and multivariate Mendelian randomization. Results Genetically predicted CD was positively associated with osteoporosis risk, with ORs of 1.060 (95% CIs 1.016, 1.106; p = 0.007) and 1.044 (95% CIs 1.002, 1.088; p = 0.039) for CD in the training and validation sets, respectively. However, Mendelian randomization analysis did not reveal a significant causal relationship between UC and osteoporosis (p > 0.05). Furthermore, we found that overall IBD was associated with osteoporosis prediction, with ORs of 1.050 (95% CIs 0.999, 1.103; p = 0.055) and 1.063 (95% CIs 1.019, 1.109; p = 0.005) in the training and validation sets, respectively. Conclusion We demonstrated the causal association between CD and osteoporosis, complementing the framework for genetic variants that predispose to autoimmune disease.
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Affiliation(s)
- Zhujiang Dai
- Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Shanghai Colorectal Cancer Research Center, Shanghai, China
| | - Weimin Xu
- Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Shanghai Colorectal Cancer Research Center, Shanghai, China
| | - Rui Ding
- Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Shanghai Colorectal Cancer Research Center, Shanghai, China
| | - Xiang Peng
- Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Shanghai Colorectal Cancer Research Center, Shanghai, China
| | - Xia Shen
- Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Shanghai Colorectal Cancer Research Center, Shanghai, China
| | - Jinglue Song
- Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Shanghai Colorectal Cancer Research Center, Shanghai, China
| | - Peng Du
- Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Shanghai Colorectal Cancer Research Center, Shanghai, China
| | - Zhongchuan Wang
- Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Shanghai Colorectal Cancer Research Center, Shanghai, China
| | - Yun Liu
- Department of Colorectal Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
- Shanghai Colorectal Cancer Research Center, Shanghai, China
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Abdel-Hamid MS, Elhossini RM, Otaify GA, Abdel-Ghafar SF, Aglan MS. Osteoporosis-pseudoglioma syndrome in four new patients: identification of two novel LRP5 variants and insights on patients' management using bisphosphonates therapy. Osteoporos Int 2022; 33:1501-1510. [PMID: 35106624 DOI: 10.1007/s00198-022-06313-1] [Citation(s) in RCA: 4] [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: 10/21/2021] [Accepted: 01/18/2022] [Indexed: 11/30/2022]
Abstract
UNLABELLED This study describes the clinical, radiological, and molecular data of four new patients with osteoporosis-pseudoglioma syndrome and assesses their response to bisphosphonate therapy. INTRODUCTION Osteoporosis-pseudoglioma syndrome (OPPG) is a very rare disorder characterized mainly by severe juvenile osteoporosis and congenital blindness. OPPG is caused by biallelic mutations in the gene encoding low-density lipoprotein receptor-related protein 5 (LRP5). METHODS We present the clinical, radiological, and molecular findings of four new patients with OPPG from Egypt. We also assessed patients' response to oral and intravenous bisphosphonate therapy. RESULTS All patients had reduced bone mineral density (BMD) with variable number of fractures per year, in addition to bone abnormalities and the characteristic eye phenotype associated with OPPG. Mutation analyses of LRP5 gene revealed three different homozygous variants including two novel ones, c.7delG (p.A3Qfs*80) and c.3280G > A (p.E1094K). The c.3280G > A (p.E1094K) was recurrent in two unrelated patients who shared a unique haplotype suggesting a possible founder effect. The use of bisphosphonate therapy was beneficial; however, intravenous bisphosphonate administration led to a more favorable response. CONCLUSION Our study described the phenotypic and genetic features of four patients with OPPG and identified two new LRP5 variants, thus expanding the mutational spectrum of OPPG. In addition, our study reinforces the efficiency of using intravenous bisphosphonates in the management of patients with OPPG.
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Affiliation(s)
- Mohamed S Abdel-Hamid
- Medical Molecular Genetics Department, Institute of Human Genetics and Genome Research, National Research Centre, Tahrir street, Dokki, Cairo, Egypt.
| | - Rasha M Elhossini
- Clinical Genetics Department, Institute of Human Genetics and Genome Research, National Research Centre, Cairo, Egypt
| | - Ghada A Otaify
- Clinical Genetics Department, Institute of Human Genetics and Genome Research, National Research Centre, Cairo, Egypt
| | - Sherif F Abdel-Ghafar
- Medical Molecular Genetics Department, Institute of Human Genetics and Genome Research, National Research Centre, Tahrir street, Dokki, Cairo, Egypt
| | - Mona S Aglan
- Clinical Genetics Department, Institute of Human Genetics and Genome Research, National Research Centre, Cairo, Egypt
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Homaei A, Chegini V, Saffari F. Clinical Response to Treatment with Teriparatide in an Adolescent with Osteoporosis-Pseudoglioma Syndrome (OPPG): A Case Report. Int J Endocrinol Metab 2022; 20:e121031. [PMID: 35993038 PMCID: PMC9383542 DOI: 10.5812/ijem-121031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 03/27/2022] [Accepted: 04/04/2022] [Indexed: 12/11/2022] Open
Abstract
INTRODUCTION Osteoporosis-pseudoglioma syndrome (OPPG) is a rare autosomal recessive disorder characterized by severe osteoporosis and eye abnormalities that leads to vision loss. In this study, we report the outcome of a short period of treatment with teriparatide in one patient with OPPG. CASE PRESENTATION The patient was a 17-year-old girl who suffered a bone fracture at the age of two and was diagnosed with OPPG at the age of three. Genetic testing was performed for the patient, and a novel homozygous nonsense mutation (c.351G>A) in exon 2 of the LRP5 gene was reported. She was treated with pamidronate, but the bone fracture increased, and the disability progressed. Therefore, at the age of 11 years and nine months, teriparatide was administered subcutaneously at a dose of 20 micrograms per day for four consecutive months. After the treatment with teriparatide, physical activity was achieved, and no further fractures were observed besides the gradual rise in bone mineral density (BMD) (from 0.532 to 0.711 gr/cm2 in lumbar spine and 0.372 to 0.635 gr/cm2 in femur neck). CONCLUSIONS In children and adolescents diagnosed with OPPG who do not respond to other conventional therapies, short courses of teriparatide therapy may be helpful.
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Affiliation(s)
- Ali Homaei
- School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Victoria Chegini
- Department of Pediatrics, School of Medicine, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fatemeh Saffari
- Children Growth Research Center, Research Institute for Prevention of Non-communicable Diseases, Qazvin University of Medical Sciences, Qazvin, Iran
- Clinical Research Development Unit, Qods Hospital, Qazvin University of Medical Sciences, Qazvin, Iran
- Corresponding Author: Children Growth Research Center, Research Institute for Prevention of Non-communicable Diseases, Qazvin University of Medical Sciences, Qazvin, Iran.
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Uludağ Alkaya D, Uyguner ZO, Güneş N, Tüysüz B. Long-term follow-up findings in a Turkish girl with osteogenesis imperfecta type XX caused by a homozygous MESD variant. Am J Med Genet A 2022; 188:1639-1646. [PMID: 35092157 DOI: 10.1002/ajmg.a.62664] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 10/01/2021] [Accepted: 10/10/2021] [Indexed: 11/09/2022]
Abstract
Osteogenesis imperfecta (OI) is a heterogeneous group of disorders with bone fragility. In 2019, homozygous pathogenic variants in MESD were described for the first time in five patients with severe form of OI. To date, 12 patients have been reported. The aim of this study is to report long-term follow-up findings of a girl with MESD variant. She had triangular face, sparse hair, wide fontanelle, blue sclera, softening of the occipital bone, congenital torticollis, and long fingers. Wormian bones, multiple rib and long bone fractures, and platyspondyly were detected in her skeletal radiographs. During the 21-years follow-up, intellectual disability, oligodontia, recurrent fractures, bowing of humerus, hip and knee contractures leading to crossing of the legs, swelling of the interphalangeal joints, and kyphoscoliosis were observed. Although the bisphosphonate treatment was started at 2.5 years of age, recurrent fractures continued to occur until 13 years of age. She lost her walking ability at 4.5 years of age. The final adult height was 128 cm (-6.0 SD). Homozygous c.631_632delAA (p.Lys211Glufs*19) variant in MESD was detected at 19 years of age. In conclusion, this study provides long-term clinical and radiological findings in a patient with a very rare type of OI.
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Affiliation(s)
- Dilek Uludağ Alkaya
- Department of Pediatric Genetics, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Zehra Oya Uyguner
- Department of Medical Genetics, Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Nilay Güneş
- Department of Pediatric Genetics, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Beyhan Tüysüz
- Department of Pediatric Genetics, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey
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Khrystoforova I, Shochat-Carvalho C, Harari R, Henke K, Woronowicz K, Harris MP, Karasik D. Zebrafish mutants reveal unexpected role of Lrp5 in osteoclast regulation. Front Endocrinol (Lausanne) 2022; 13:985304. [PMID: 36120446 PMCID: PMC9478031 DOI: 10.3389/fendo.2022.985304] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 08/16/2022] [Indexed: 11/24/2022] Open
Abstract
Low-density Lipoprotein Receptor-related Protein 5 (LRP5) functions as a co-receptor for Wnt ligands, controlling expression of genes involved in osteogenesis. In humans, loss-of-function mutations in LRP5 cause Osteoporosis-Pseudoglioma syndrome, a low bone mass disorder, while gain-of-function missense mutations have been observed in individuals with high bone mass. Zebrafish (Danio rerio) is a popular model for human disease research, as genetic determinants that control bone formation are generally conserved between zebrafish and mammals. We generated lrp5- knock-out zebrafish to study its role in skeletogenesis and homeostasis. Loss of lrp5 in zebrafish leads to craniofacial deformities and low bone mineral density (total body and head) at adult ages. To understand the mechanism and consequences of the observed phenotypes, we performed transcriptome analysis of the cranium of adult lrp5 mutants and siblings. Enrichment analysis revealed upregulation of genes significantly associated with hydrolase activity: mmp9, mmp13a, acp5a. acp5a encodes Tartrate-resistant acid phosphatase (TRAP) which is commonly used as an osteoclast marker, while Matrix metalloprotease 9, Mmp9, is known to be secreted by osteoclasts and stimulate bone resorption. These genes point to changes in osteoclast differentiation regulated by lrp5. To analyze these changes functionally, we assessed osteoclast dynamics in mutants and observed increased TRAP staining, significantly larger resorption areas, and developmental skeletal dysmorphologies in the mutant, suggesting higher resorptive activity in the absence of Lrp5 signaling. Our findings support a conserved role of Lrp5 in maintaining bone mineral density and revealed unexpected insights into the function of Lrp5 in bone homeostasis through moderation of osteoclast function.
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Affiliation(s)
| | | | - Ram Harari
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Katrin Henke
- Department of Orthopedics, Emory University, Atlanta, GA, United States
| | - Katherine Woronowicz
- Department of Orthopaedics, Boston Children’s Hospital, Boston, MA, United States
- Department of Genetics, Harvard Medical School, Boston, MA, United States
| | - Matthew P. Harris
- Department of Orthopaedics, Boston Children’s Hospital, Boston, MA, United States
- Department of Genetics, Harvard Medical School, Boston, MA, United States
| | - David Karasik
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
- *Correspondence: David Karasik,
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Yang Z, Liu J, Fu J, Li S, Chai Z, Sun Y. Associations between WNT signaling pathway-related gene polymorphisms and risks of osteoporosis development in Chinese postmenopausal women: a case-control study. Climacteric 2021; 25:257-263. [PMID: 34254535 DOI: 10.1080/13697137.2021.1941848] [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] [Indexed: 10/20/2022]
Abstract
BACKGROUND The WNT signaling pathway is involved in the regulation of bone homeostasis, and the effect of WNT signaling pathway-related gene (WNT16 and LRP5) polymorphisms on osteoporosis risk among Chinese postmenopausal women is still unknown. Hence, we performed a case-control study to assess the association of WNT signaling pathway-related gene polymorphisms and osteoporosis risk. METHODS A total of 1026 women (515 osteoporosis patients and 511 controls) of postmenopausal age who were randomly sampled from Xi'an 630 Hospital (Shaanxi Province, China) were involved in this study. Seven genetic polymorphisms in WNT16 (rs3779381, rs3801387, rs917727 and rs7776725) and LRP5 (rs2291467, rs11228240 and rs12272917) were selected and genotyped using the Agena MassARRAY iPLEX system. The association of the genetic polymorphisms and osteoporosis risk was assessed by odds ratios and 95% confidence intervals. The multifactor dimensionality reduction (MDR) method was conducted to analyze single nucleotide polymorphism (SNP)-SNP interaction. RESULTS We found that LRP5 polymorphisms (rs2291467, rs11228240 and rs12272917) were significantly associated with a decreased risk of osteoporosis in homozygote, recessive and additive models (p < 0.05). Stratification analysis showed that LRP5 polymorphisms (rs2291467, rs11228240 and rs12272917) significantly decreased the osteoporosis risk in the subgroup of body mass index (BMI) ≤ 24 (p < 0.05) and that individuals carrying a heterozygote genotype of WNT16 polymorphisms (rs3779381, rs3801387, rs917727 and rs7776725) had a higher osteoporosis risk in the subgroup of BMI > 24 (p < 0.05). Two haplotypes (haplotype 1: rs3779381, rs3801387, rs917727 and rs7776725; haplotype 2: rs2291467 and rs11228240) were observed, yet only Trs2291467Trs11228240 and Crs2291467Crs11228240 had a strong association with a decreased risk of osteoporosis (p < 0.05). Additionally, MDR analysis revealed that LRP5 rs2291467 was the best model in single-locus MDR analysis. A seven-locus model including rs3779381-AG, rs7776725-TC, rs3801387-GA and rs917727-TC in WNT16 and rs11228240-CC, rs12272917-TC and rs2291467-CC in LRP5 was the best model in multiple-loci MDR analysis (p < 0.001). These two best models were the most significantly associated with osteoporosis risk. CONCLUSIONS Our findings suggested that WNT16 and LRP5 genetic polymorphisms are associated with osteoporosis risk among Chinese postmenopausal women.
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Affiliation(s)
- Z Yang
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
| | - J Liu
- Department of Internal Neurology, Inner Mongolia Medical University Affiliated Hospital, Hohhot, China
| | - J Fu
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
| | - S Li
- Department of Minimal Invasive Spine Surgery, The Second Affiliated Hospital of Inner Mongolia Medical College, Hohhot, China
| | - Z Chai
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
| | - Y Sun
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
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Güemes-Villahoz N, Acón D, Hamichi SE, Tanenbaum R, Berrocal AM. Serpiginous Intraretinal Lesions Associated With Familial Exudative Vitreoretinopathy. Ophthalmic Surg Lasers Imaging Retina 2021; 52:155-159. [PMID: 34038691 DOI: 10.3928/23258160-20210302-07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Familial exudative vitreoretinopathy (FEVR) is a rare inherited disorder affecting retinal angiogenesis that may present with a wide range of phenotypic characteristics. In this report, the authors describe an atypical presentation of FEVR in a healthy 9-year-old male with progressive decreased visual acuity in the left eye. Fundus examination showed an avascular retina in the temporal periphery bilaterally. The left eye also revealed serpiginous hypopigmented lesions in the superior quadrant, which showed intraretinal location on optical coherence tomography and hyperautofluorescence. Genetic testing revealed LRP5 mutation, confirming a diagnosis of FEVR. The serpiginous lesions represent an unusual finding associated with FEVR not previously described in the literature. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:155-159.].
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Li L, Qiu X, Zhang N, Sun Y, Wang Y, Wang L. Crosstalk between adipocytes and M2 macrophages compensates for osteopenic phenotype in the Lrp5-deficient mice. Exp Biol Med (Maywood) 2021; 246:572-583. [PMID: 33197324 PMCID: PMC7934148 DOI: 10.1177/1535370220972320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/19/2020] [Indexed: 02/06/2023] Open
Abstract
A loss-of-function mutation in the Lrp5 gene in mice leads to a low bone mass disorder due to the inhibition of the canonical Wnt signaling pathway; however, the role of bone marrow microenvironment in mice with this mutation remains unclear. In this study, we evaluated proliferation and osteogenic potential of mouse osteoblasts using the MTT assay and Alizarin red staining. The levels of alkaline phosphatase, tartrate-resistant acid phosphatase, and adiponectin in culture supernatants were measured using the enzyme-linked immunosorbent assay. Osteoclast bone resorbing activity was evaluated by toluidine staining and the number and area of bone resorption pits were determined. We observed increased osteogenesis in osteoblasts co-cultured with the BM-derived myeloid cells compared to the osteoblasts cultured alone. Mice with global Lrp5 deletion had a relatively higher bone density compared to the mice carrying osteoblast/osteocyte-specific Lrp5 deletion. An increased frequency of M2 macrophages and reduced expression of inflammatory cytokines were detected in the myeloid cells derived from the bone marrow of mice with global Lrp5 deletion. Higher adipogenic potential and elevated levels of adiponectin in the global Lrp5 deletion mice contributed to the preferential M2 macrophage polarization. Here, we identified a novel systemic regulatory mechanism of bone formation and degradation in mice with global Lrp5 deletion. This mechanism depends on a crosstalk between the adipocytes and M2 macrophages in the bone marrow and is responsible for partly rescuing osteopenia developed as a result of decreased Wnt signaling.
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Affiliation(s)
- Lisha Li
- Obstetrics and Gynecology Hospital of Fudan University, Shanghai 200011, China
- The Academy of Integrative Medicine of Fudan University, Shanghai 200011, China
- Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Shanghai 200011, China
| | - Xuemin Qiu
- Obstetrics and Gynecology Hospital of Fudan University, Shanghai 200011, China
- The Academy of Integrative Medicine of Fudan University, Shanghai 200011, China
- Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Shanghai 200011, China
| | - Na Zhang
- Obstetrics and Gynecology Hospital of Fudan University, Shanghai 200011, China
- The Academy of Integrative Medicine of Fudan University, Shanghai 200011, China
- Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Shanghai 200011, China
| | - Yan Sun
- Obstetrics and Gynecology Hospital of Fudan University, Shanghai 200011, China
- The Academy of Integrative Medicine of Fudan University, Shanghai 200011, China
- Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Shanghai 200011, China
| | - Yan Wang
- Obstetrics and Gynecology Hospital of Fudan University, Shanghai 200011, China
| | - Ling Wang
- Obstetrics and Gynecology Hospital of Fudan University, Shanghai 200011, China
- The Academy of Integrative Medicine of Fudan University, Shanghai 200011, China
- Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Shanghai 200011, China
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Yamada M, Kubota K, Uchida A, Yagihashi T, Kawasaki M, Suzuki H, Uehara T, Takenouchi T, Kurosaka H, Kosaki K. Fork-shaped mandibular incisors as a novel phenotype of LRP5-associated disorder. Am J Med Genet A 2021; 185:1544-1549. [PMID: 33619830 DOI: 10.1002/ajmg.a.62132] [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: 09/28/2020] [Revised: 01/10/2021] [Accepted: 02/06/2021] [Indexed: 11/10/2022]
Abstract
The LRP5 gene encodes a Wnt signaling receptor to which Wnt binds directly. In humans, pathogenic monoallelic variants in LRP5 have been associated with increased bone density and exudative vitreoretinopathy. In mice, LRP5 plays a role in tooth development, including periodontal tissue stability and cementum formation. Here, we report a 14-year-old patient with a de novo non-synonymous variant, p.(Val1245Met), in LRP5 who exhibited mildly reduced bone density and mild exudative vitreoretinopathy together with a previously unreported phenotype consisting of dental abnormalities that included fork-like small incisors with short roots and an anterior open bite, molars with a single root, and severe taurodontism. In that exudative vitreoretinopathy has been reported to be associated with heterozygous loss-of-function variants of LRP5 and that our patient reported here with the p.(Val1245Met) variant had mild exudative vitreoretinopathy, the variant can be considered as an incomplete loss-of-function variant. Alternatively, the p.(Val1245Met) variant can be considered as exerting a dominant-negative effect, as no patients with truncating LRP5 variants and exudative vitreoretinopathy have been reported to exhibit dental anomalies. The documentation of dental anomalies in the presently reported patient strongly supports the notion that LRP5 plays a critical role in odontogenesis in humans, similar to its role in mice.
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Affiliation(s)
- Mamiko Yamada
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
| | - Kazumi Kubota
- Department of Plastic and Reconstructive Surgery, Keio University School of Medicine, Tokyo, Japan.,Department of Special Needs Dentistry, Division of Hygiene and Oral Health, Showa University School of Dentistry, Tokyo, Japan
| | - Atsuro Uchida
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Tatsuhiko Yagihashi
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
| | | | - Hisato Suzuki
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
| | - Tomoko Uehara
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan.,Department of Pediatrics, Central Hospital, Aichi Developmental Disability Center, Kasugai, Aichi, Japan
| | - Toshiki Takenouchi
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
| | - Hiroshi Kurosaka
- Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Osaka University, Osaka, Japan
| | - Kenjiro Kosaki
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
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Estell EG, Rosen CJ. Emerging insights into the comparative effectiveness of anabolic therapies for osteoporosis. Nat Rev Endocrinol 2021; 17:31-46. [PMID: 33149262 DOI: 10.1038/s41574-020-00426-5] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/18/2020] [Indexed: 01/01/2023]
Abstract
Over the past three decades, the mainstay of treatment for osteoporosis has been antiresorptive agents (such as bisphosphonates), which have been effective with continued administration in lowering fracture risk. However, the clinical landscape has changed as adherence to these medications has declined due to perceived adverse effects. As a result, decreases in hip fracture rates that followed the introduction of bisphosphonates have now levelled off, which is coincident with a decline in the use of the antiresorptive agents. In the past two decades, two types of anabolic agents (including three new drugs), which represent a novel approach to improving bone quality by increasing bone formation, have been approved. These therapies are expected to lead to a new clinical paradigm in which anabolic agents will be used either alone or in combination with antiresorptive agents to build new bone and reduce fracture risk. This Review examines the mechanisms of action for these anabolic agents by detailing their receptor-activating properties for key cell types in the bone and marrow niches. Using these advances in bone biology as context, the comparative effectiveness of these anabolic agents is discussed in relation to other therapeutic options for osteoporosis to better guide their clinical application in the future.
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Affiliation(s)
- Eben G Estell
- Maine Medical Center Research Institute, Scarborough, ME, USA
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Wang QF, Bi HS, Qin ZL, Wang P, Nie FF, Zhang GW. Associations of LRP5 Gene With Bone Mineral Density, Bone Turnover Markers, and Fractures in the Elderly With Osteoporosis. Front Endocrinol (Lausanne) 2020; 11:571549. [PMID: 33101205 PMCID: PMC7545741 DOI: 10.3389/fendo.2020.571549] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 08/20/2020] [Indexed: 12/06/2022] Open
Abstract
Objective: The study aimed to explore the associations of rs4988300 and rs634008 in the low-density lipoprotein receptor-related protein 5 (LRP5) gene with bone mineral density (BMD), bone turnover markers (BTM), and fractures in elderly patients with osteoporosis (OP). Methods: Our study included 328 unrelated OP patients with or without fractures. Genomic DNA was extracted for genotyping. BTM levels were assessed by electrochemiluminescence (ECL). Dual-energy X-ray absorptiometry (DXA) was employed to measure BMD in the lumbar spine (LS) and proximal femur. Basic features between the OP and fracture groups were analyzed using the t-test. The Chi-square test was performed to analyze the differences in allele and genotype frequencies. The associations of single-nucleotide polymorphisms (SNPs) with BMD and BTM in the subgroups were investigated by the analysis of covariance (ANCOVA) adjusted for confounding factors. Results: In both females and males, individuals with fractures exhibited higher BTM levels and lower BMD values than those with OP (P < 0.05). The allele and genotype frequencies of rs4988300 in the subgroups were significantly different (P < 0.05). In both females and males suffering from OP, participants with rs4988300 GG or rs634008 TT presented lower procollagen I N-terminal propeptide (PINP) levels (P < 0.05). Women with OP carrying rs4988300 GG exhibited lower BMD values at FN and TH (P < 0.05). In both females and males with fractures, individuals carrying rs4988300 GG genotype or rs634008 TT genotype exhibited lower PINP levels and BMD values at FN and TH than those with other genotypes (P < 0.05). Conclusions: Rs4988300 and rs634008 polymorphisms in the LRP5 gene are associated with bone phenotypes in the elderly with OP or fractures.
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Affiliation(s)
- Qi-Fei Wang
- Department of Plastic Surgery, Peking University Third Hospital, Beijing, China
| | - Hong-Sen Bi
- Department of Plastic Surgery, Peking University Third Hospital, Beijing, China
| | - Ze-Lian Qin
- Department of Plastic Surgery, Peking University Third Hospital, Beijing, China
- *Correspondence: Ze-Lian Qin
| | - Pu Wang
- Department of Plastic Surgery, Peking University Third Hospital, Beijing, China
| | - Fang-Fei Nie
- Department of Plastic Surgery, Peking University Third Hospital, Beijing, China
| | - Guang-Wu Zhang
- Department of Orthopedics, Peking University Shougang Hospital, Beijing, China
- Guang-Wu Zhang
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Abstract
The phenotypic trait of high bone mass (HBM) is an excellent example of the nexus between common and rare disease genetics. HBM may arise from carriage of many 'high bone mineral density [BMD]'-associated alleles, and certainly the genetic architecture of individuals with HBM is enriched with high BMD variants identified through genome-wide association studies of BMD. HBM may also arise as a monogenic skeletal disorder, due to abnormalities in bone formation, bone resorption, and/or bone turnover. Individuals with monogenic disorders of HBM usually, though not invariably, have other skeletal abnormalities (such as mandible enlargement) and thus are best regarded as having a skeletal dysplasia rather than just isolated high BMD. A binary etiological division of HBM into polygenic vs. monogenic, however, would be excessively simplistic: the phenotype of individuals carrying rare variants of large effect can still be modified by their common variant polygenic background, and by the environment. HBM disorders-whether predominantly polygenic or monogenic in origin-are not only interesting clinically and genetically: they provide insights into bone processes that can be exploited therapeutically, with benefits both for individuals with these rare bone disorders and importantly for the many people affected by the commonest bone disease worldwide-i.e., osteoporosis. In this review we detail the genetic architecture of HBM; we provide a conceptual framework for considering HBM in the clinical context; and we discuss monogenic and polygenic causes of HBM with particular emphasis on anabolic causes of HBM.
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Affiliation(s)
- Celia L. Gregson
- Musculoskeletal Research Unit, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
- *Correspondence: Celia L. Gregson, ; Emma L. Duncan,
| | - Emma L. Duncan
- Department of Twin Research & Genetic Epidemiology, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King’s College London, London, United Kingdom
- *Correspondence: Celia L. Gregson, ; Emma L. Duncan,
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