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Fujii Y, Okabe I, Hatori A, Sah SK, Kanaujiya J, Fisher M, Norris R, Terasaki M, Reichenberger EJ, Chen IP. Skeletal abnormalities caused by a Connexin43 R239Q mutation in a mouse model for autosomal recessive craniometaphyseal dysplasia. RESEARCH SQUARE 2024:rs.3.rs-3906170. [PMID: 38405920 PMCID: PMC10889043 DOI: 10.21203/rs.3.rs-3906170/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Craniometaphyseal dysplasia (CMD), a rare craniotubular disorder, occurs in an autosomal dominant (AD) or autosomal recessive (AR) form. CMD is characterized by hyperostosis of craniofacial bones and flaring metaphyses of long bones. Many patients with CMD suffer from neurological symptoms. To date, the pathogenesis of CMD is not fully understood. Treatment is limited to decompression surgery. Here, we report a knock in (KI) mouse model for AR CMD carrying a R239Q mutation in CX43. Cx43KI/KI mice replicate many features of AR CMD in craniofacial and long bones. In contrast to Cx43+/+ littermates, Cx43KI/KI mice exhibit periosteal bone deposition and increased osteoclast (OC) numbers in the endosteum of long bones, leading to an expanded bone marrow cavity and increased cortical bone thickness. Although formation of Cx43+/+ and Cx43KI/KI resting OCs are comparable, on bone chips the actively resorbing Cx43KI/KI OCs resorb less bone. Cortical bones of Cx43KI/KI mice have an increase in degenerating osteocytes and empty lacunae. Osteocyte dendrite formation is decreased with reduced expression levels of Fgf23, Sost, Tnf-α, IL-1β, Esr1, Esr2, and a lower Rankl/Opg ratio. Female Cx43KI/KI mice display a more severe phenotype. Sexual dimorphism in bone becomes more evident as mice age. Our data show that the CX43R239Q mutation results in mislocalization of CX43 protein and impairment of gap junction and hemichannel activity. Different from CX43 ablation mouse models, the CX43R239Q mutation leads to the AR CMD-like phenotype in Cx43KI/KI mice not only by loss-of-function but also via a not yet revealed dominant function.
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Affiliation(s)
- Yasuyuki Fujii
- Department of Endodontology, School of Dental Medicine, University of Connecticut Health, Farmington, CT, United States
| | - Iichiro Okabe
- Department of Endodontology, School of Dental Medicine, University of Connecticut Health, Farmington, CT, United States
| | - Ayano Hatori
- Department of Endodontology, School of Dental Medicine, University of Connecticut Health, Farmington, CT, United States
| | - Shyam Kishor Sah
- Department of Endodontology, School of Dental Medicine, University of Connecticut Health, Farmington, CT, United States
| | - Jitendra Kanaujiya
- Department of Cell Biology, University of Connecticut Health, Farmington, CT, United States
| | - Melanie Fisher
- Department of Cell Biology, University of Connecticut Health, Farmington, CT, United States
| | - Rachael Norris
- Department of Cell Biology, University of Connecticut Health, Farmington, CT, United States
| | - Mark Terasaki
- Department of Cell Biology, University of Connecticut Health, Farmington, CT, United States
| | - Ernst J. Reichenberger
- Center for Regenerative Medicine and Skeletal Development, School of Dental Medicine, University of Connecticut Health, Farmington, CT, United States
| | - I-Ping Chen
- Department of Endodontology, School of Dental Medicine, University of Connecticut Health, Farmington, CT, United States
- Center for Regenerative Medicine and Skeletal Development, School of Dental Medicine, University of Connecticut Health, Farmington, CT, United States
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Soto Barros J, Braddock D, Carpenter TO. Hypophosphatemic rickets: An unexplained early feature of craniometaphyseal dysplasia. Bone Rep 2023; 19:101707. [PMID: 37654679 PMCID: PMC10466911 DOI: 10.1016/j.bonr.2023.101707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/08/2023] [Accepted: 08/16/2023] [Indexed: 09/02/2023] Open
Abstract
Craniometaphyseal dysplasia (CMD) is an infrequently occurring skeletal dysplasia often caused by a mutation in ANKH. The most common features are early and progressive hyperostosis of craniofacial bones, which may cause obstruction of cranial nerves, and metaphyseal flaring of long bones. Rarely, rickets has been associated with CMD, occurring early in the course of the disease. We report an infant with CMD who presented with elevated serum alkaline phosphatase activity and low serum phosphorus at age 1 month and radiographic changes of rickets at 3 months of age. Further biochemical investigations revealed a high tubular reabsorption of phosphate and suppressed FGF23 level congruent with a deficit of phosphorus availability. Therapy with phosphorus was started at 4 months of age; calcitriol was subsequently added upon emergence of secondary hyperparathyroidism. A heterozygous pathogenic variant in ANKH c.1124_1126del (p.Ser375del) was identified. At 19 months of age therapy was discontinued in view of the corrected biochemical profile and radiographic improvement of rickets. ©The Authors. All rights reserved.
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Affiliation(s)
- Julio Soto Barros
- Department of Pediatrics, Faculty of Medicine, University of Concepcion, Chacabuco esquina Janequeo S/N, 4070106 Concepcion, Chile
- Las Higueras Hospital, Alto Horno 777, 4270918 Talcahuano, Chile
- Department of Pediatrics (Endocrinology), Yale University School of Medicine, PO Box 208064, New Haven, CT 06520-8064, USA
| | - Demetrios Braddock
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Thomas O Carpenter
- Department of Pediatrics (Endocrinology), Yale University School of Medicine, PO Box 208064, New Haven, CT 06520-8064, USA
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Fujii Y, Kozak E, Dutra E, Varadi A, Reichenberger EJ, Chen IP. Restriction of Dietary Phosphate Ameliorates Skeletal Abnormalities in a Mouse Model for Craniometaphyseal Dysplasia. J Bone Miner Res 2020; 35:2070-2081. [PMID: 33463757 PMCID: PMC9164311 DOI: 10.1002/jbmr.4110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/22/2020] [Accepted: 06/07/2020] [Indexed: 11/08/2022]
Abstract
Craniometaphyseal dysplasia (CMD), a rare genetic bone disorder, is characterized by lifelong progressive thickening of craniofacial bones and metaphyseal flaring of long bones. The autosomal dominant form of CMD is caused by mutations in the progressive ankylosis gene ANKH (mouse ortholog Ank), encoding a pyrophosphate (PPi) transporter. We previously reported reduced formation and function of osteoblasts and osteoclasts in a knockin (KI) mouse model for CMD (AnkKI/KI) and in CMD patients. We also showed rapid protein degradation of mutant ANK/ANKH. Mutant ANK protein displays reduced PPi transport, which may alter the inorganic phosphate (Pi) and PPi ratio, an important regulatory mechanism for bone mineralization. Here we investigate whether reducing dietary Pi intake can ameliorate the CMD-like skeletal phenotype by comparing male and female Ank+/+ and AnkKI/KI mice exposed to a low (0.3%) and normal (0.7%) Pi diet for 13 weeks from birth. Serum Pi and calcium (Ca) levels were not significantly changed by diet, whereas PTH and 25-hydroxy vitamin D (25-OHD) were decreased by low Pi diet but only in male Ank+/+ mice. Importantly, the 0.3% Pi diet significantly ameliorated mandibular hyperostosis in both sexes of AnkKI/KI mice. A tendency of decreased femoral trabeculation was observed in male and female Ank+/+ mice as well as in male AnkKI/KI mice fed with the 0.3% Pi diet. In contrast, in female AnkKI/KI mice the 0.3% Pi diet resulted in increased metaphyseal trabeculation. This was also the only group that showed increased bone formation rate. Low Pi diet led to increased osteoclast numbers and increased bone resorption in all mice. We conclude that lowering but not depleting dietary Pi delays the development of craniofacial hyperostosis in CMD mice without severely compromising serum levels of Pi, Ca, PTH, and 25-OHD. These findings may have implications for better clinical care of patients with CMD. © 2020 American Society for Bone and Mineral Research.
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Affiliation(s)
- Yasuyuki Fujii
- Department of Oral Health and Diagnostic Sciences, School of Dental Medicine, University of Connecticut Health, Farmington, CT, USA
| | - Eszter Kozak
- Institute of Enzymology, Research Center for Natural Sciences, Hungarian Academy of Sciences Centre of Excellence, Budapest, Hungary
| | - Eliane Dutra
- Department of Craniofacial Sciences, School of Dental Medicine, University of Connecticut Health, Farmington, CT, USA
| | - Andras Varadi
- Institute of Enzymology, Research Center for Natural Sciences, Hungarian Academy of Sciences Centre of Excellence, Budapest, Hungary
| | - Ernst J Reichenberger
- Department of Reconstructive Sciences, School of Dental Medicine, University of Connecticut Health, Farmington, CT, USA
| | - I-Ping Chen
- Department of Oral Health and Diagnostic Sciences, School of Dental Medicine, University of Connecticut Health, Farmington, CT, USA
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Dai G, Wang D, Dong H. Effects of recombinant human growth hormone on protein malnutrition and IGF-1 and IL-2 gene expression levels in chronic nephrotic syndrome. Exp Ther Med 2018; 15:4167-4172. [PMID: 29725365 PMCID: PMC5920232 DOI: 10.3892/etm.2018.5953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 12/11/2017] [Indexed: 11/05/2022] Open
Abstract
The aim of the study was to investigate the effects of recombinant human growth hormone on protein malnutrition and insulin-like growth factor-1 (IGF-1) and interleukin-2 (IL-2) gene expressions in chronic nephrotic syndrome. Eighty patients with chronic nephrotic syndrome were admitted to our hospital. The patients were included in the study period from January 2015 to December 2016 and were divided into two groups (40 cases in each group) according to the random number method. All the patients enrolled received symptomatic and supportive treatment. The observation group was injected subcutaneously with recombinant human growth hormone, while the control group was treated with Shenyankangfu tablets. The recovery time of the clinical symptoms, change in serum protein, caloric intake and protein metabolism after intervention were compared between the two groups. Changes in serum cystatin C, IGF-1 and IL-2 before intervention, and at 1 week, 1 month and 3 months after intervention were detected, and the adverse reactions in the two groups were observed during the treatment. After intervention, the improvement time of proteinuria, hypoproteinemia, edema and hyperlipidemia in the observation group was significantly shorter than that in the control group (P<0.05). The expression of transferrin, pre-albumin, albumin and total protein in the observation group was significantly superior increased compared to those in the observation group prior to intervention and the control group after intervention (P<0.05). In addition the caloric intake, protein intake and urea nitrogen survival rate in the observation group were significantly superior to those in the observation group prior to intervention and the control group after intervention (P<0.05). At 1 week, 1 month and 3 months after intervention, the levels of serum cystatin C, IGF-1 and IL-2 in the observation group were markedly obviously lower than those in the control group during the same period (P<0.05). The total proportion of allergy, systemic pruritus, nausea and vomiting, abdominal distension and abdominal pain in the observation group was obviously lower than that in the control group (P<0.05). Compared with the traditional Chinese medicine Shenyankangfu tablets applied in the control group, the recombinant human growth hormone used for patients with chronic nephrotic syndrome can improve the clinical symptoms more quickly, regulate the protein metabolism and reduce the inflammatory response in the body, which also has fewer adverse reactions and higher safety.
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Affiliation(s)
- Guang Dai
- Department of Nephrology, Zhumadian Central Hospital, Zhumadian, Henan 463000, P.R. China
| | - Donghai Wang
- Department of Nephrology, Zhumadian Central Hospital, Zhumadian, Henan 463000, P.R. China
| | - Hua Dong
- Department of Nephrology, The Affiliated Hospital of Binzhou Medical College, Binzhou, Shandong 256603, P.R. China
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