Basic Research
Generation and phenotype of myeloid cell specific Clcn7-mutation osteopetrosis mouse model
Wang Ziyuan, Lyu Shanshan, Li Xiang, Zhang Zhenlin, Wang Chun
Published 2022-04-25
Cite as Chin J Endocrinol Metab, 2022, 38(4): 313-321. DOI: 10.3760/cma.j.cn311282-20211224-00813
Abstract
ObjectiveTo construct a myeloid cell specific Clcn7-G763R mutant mouse model and characterize its phenotype.
MethodsA mouse conditional knocked in p. G763R mutation in Clcn7 gene was constructed and bred with LysM cre mice to obtain osteopetrosis mice with myeloid cell specific Clcn7-G763R mutation. The differences of bone mass in mice with different genotypes were analyzed using Micro CT and the changes of histology were observed with HE staining. Osteoclasts were cultured and the expression levels of osteoclasts differentiation and maturation-related genes were detected by real-time PCR. The functions of osteoclasts were examined through bone resorption assay.
ResultsThe body weight of homozygous mutant mice at 4 weeks old was reduced compared with the wild type mice [(12.000±1.666)g vs(15.630±2.314)g, P=0.021], with shorter femur length [(1.160±0.096)cm vs (1.300±0.082)cm, P=0.037]. Micro CT showed that bone mineral density of homozygous mutant mice was remarkably increased at 4 weeks old [(0.753±0.002)g/cm3vs(0.143±0.034)g/cm3, P=0.003], while bone mineral density of heterozygous mutant mice increased significantly at 8 weeks old [(0.236±0.021)g/cm3vs(0.180±0.020)g/cm3, P=0.030]. HE staining revealed increased trabecula bone volume in the mutant mice, especially in homozygous mutant mice with narrow bone marrow cavity and wider hypertrophic zone of chondrocytes. There was no significant difference in the number of osteoclasts between wild type mice and heterozygous mice in vitro(P=0.358), while total area of osteoclasts increased in heterozygous mutant mice [(3.590×106±0.911×106)μm2vs(1.352×106±0.260×106)μm2, P=0.043]. Impaired function of resorption was unveiled by bone resorption assay. There were no significant differences in the expressions of osteoclast differentiation and maturity-related genes including NFATc1, c-fos, Ctsk, and Acp5 between the two groups.
ConclusionA myeloid cell specific Clcn7-G763R mutation mice with impaired osteoclasts and increased bone mass is successfully constructed.
Key words:
Osteopetrosis; CLCN7; Osteoclast
Contributor Information
Wang Ziyuan
Shanghai Clinical Research Center of Bone Diseases, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People′s Hospital, Shanghai 200233, China
Lyu Shanshan
Shanghai Clinical Research Center of Bone Diseases, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People′s Hospital, Shanghai 200233, China
Li Xiang
Shanghai Clinical Research Center of Bone Diseases, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People′s Hospital, Shanghai 200233, China
Zhang Zhenlin
Shanghai Clinical Research Center of Bone Diseases, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People′s Hospital, Shanghai 200233, China
Wang Chun
Shanghai Clinical Research Center of Bone Diseases, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People′s Hospital, Shanghai 200233, China
本文作者需要对一些地方进行更正。
(1)第314页左栏第31行：Clcn7-R767W应为CLCN7-G741R;
(2)第319页左栏第2~5行：删去“CLCN7-R767W突变位于CBS2结构域，是中国人群的热点突变[6]Leisle等[3]等研究发现R767W突变位点的电流降低，这可能是该突变致骨硬化症的原因之一”。