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Mo S, Kim MK, Jang JS, Lee SH, Hong SJ, Jung S, Kim HH. Unique expression and critical role of metallothionein 3 in the control of osteoclastogenesis and osteoporosis. Exp Mol Med 2024:10.1038/s12276-024-01290-3. [PMID: 39085359 DOI: 10.1038/s12276-024-01290-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 05/16/2024] [Accepted: 05/17/2024] [Indexed: 08/02/2024] Open
Abstract
Bone homeostasis is maintained by an intricate balance between osteoclasts and osteoblasts, which becomes disturbed in osteoporosis. Metallothioneins (MTs) are major contributors in cellular zinc regulation. However, the role of MTs in bone cell regulation has remained unexplored. Single-cell RNA sequencing analysis discovered that, unlike the expression of other MT members, the expression of MT3 was unique to osteoclasts among various macrophage populations and was highly upregulated during osteoclast differentiation. This unique MT3 upregulation was validated experimentally and supported by ATAC sequencing data analyses. Downregulation of MT3 by gene knockdown or knockout resulted in excessive osteoclastogenesis and exacerbated bone loss in ovariectomy-induced osteoporosis. Transcriptome sequencing of MT3 knockdown osteoclasts and gene set enrichment analysis indicated that the oxidative stress and redox pathways were enriched, which was verified by MT3-dependent regulation of reactive oxygen species (ROS). In addition, MT3 deficiency increased the transcriptional activity of SP1 in a manner dependent on intracellular zinc levels. This MT3-zinc-SP1 axis was crucial for the control of osteoclasts, as zinc chelation and SP1 knockdown abrogated the promotion of SP1 activity and osteoclastogenesis by MT3 deletion. Moreover, SP1 bound to the NFATc1 promoter, and overexpression of an inactive SP1 mutant negated the effects of MT3 deletion on NFATc1 and osteoclastogenesis. In conclusion, MT3 plays a pivotal role in controlling osteoclastogenesis and bone metabolism via dual axes involving ROS and SP1. The present study demonstrated that MT3 elevation is a potential therapeutic strategy for osteolytic bone disorders, and it established for the first time that MT3 is a crucial bone mass regulator.
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Affiliation(s)
- Shenzheng Mo
- Department of Cell and Developmental Biology, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea
- Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea
| | - Min Kyung Kim
- Department of Cell and Developmental Biology, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea
- Bone Science R&D Center, Tissue Regeneration Institute, Osstem Implant, Seoul, 07789, Republic of Korea
| | - Ji Sun Jang
- Department of Cell and Developmental Biology, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea
- Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea
| | - Seung Hye Lee
- Department of Cell and Developmental Biology, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea
- Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea
| | - Seo Jin Hong
- Department of Cell and Developmental Biology, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea
| | - Suhan Jung
- Department of Cell and Developmental Biology, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea
| | - Hong-Hee Kim
- Department of Cell and Developmental Biology, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea.
- Dental Research Institute, School of Dentistry, Seoul National University, Seoul, 03080, Republic of Korea.
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Hu Y, Zhang B, Chen L, He J, Yang L, Chen X. SCAF4 variants are associated with epilepsy with neurodevelopmental disorders. Seizure 2024; 116:113-118. [PMID: 37891035 DOI: 10.1016/j.seizure.2023.10.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 10/17/2023] [Accepted: 10/20/2023] [Indexed: 10/29/2023] Open
Abstract
AIMS The genetic causes of epilepsy with unknown etiology in most patients remain unknown. The aim of this study was to elucidate the phenotype of SCAF4-related epilepsy. METHODS Trio-based whole-exome sequencing was performed in patients with epilepsy. Silico programs and protein modeling were employed to predict the damaging of variants. Previously reported SCAF4 variants were systematically reviewed to analyze the genotype-phenotype correlations. RESULTS Three heterozygous variants in the SCAF4 were detected in three cases, including one missense variant and two frameshift variants. All variants were de novo. None of these variants is present in gnomAD controls. The missense variant was predicted to be damaging in silico tools. Protein modeling showed that two frameshift variants resulted in loss of domains, and the missense variant may disrupt a nearby phosphorylation site and alter the hydrogen bonds around 54C and the stability of the SCAF4 protein. Intellectual development was mildly delayed for all patients except for one with whom contact was lost. All probands experienced epilepsy as infrequent seizures, responded well to antiseizure drugs, and had a median [IQR] seizure onset age of 4 [1.75, 7.5] years. The variants in the domain-encoding exons and upstream exons exhibited a strong association with epilepsy. CONCLUSIONS SCAF4 is a potential causative gene of epilepsy with neurodevelopmental disorders.
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Affiliation(s)
- Yuanyuan Hu
- Epilepsy Center and Neurology Department of Children's Hospital of Soochow University, Suzhou 215000, China
| | - Bingbing Zhang
- Epilepsy Center and Neurology Department of Children's Hospital of Soochow University, Suzhou 215000, China
| | - Li Chen
- Neurogenetic Group, Department of Neurology, Shenzhen Children's Hospital, Shenzhen 518000, China
| | - Jing He
- Department of Neurology, Yuquan Hospital, Tsinghua University, Beijing 100000, China
| | - Letian Yang
- Epilepsy Center and Neurology Department of Children's Hospital of Soochow University, Suzhou 215000, China
| | - Xuqin Chen
- Epilepsy Center and Neurology Department of Children's Hospital of Soochow University, Suzhou 215000, China.
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