RanGAP1 maintains chromosome stability in limb bud mesenchymal cells during bone development

Minjun Huang; Bochong Chen; Xiaoli Chen; Tianxiao Liu; Siying Liang; Hongling Hu; Xiaochun Bai; Yan Gong

doi:10.1016/j.cellsig.2024.111222

RanGAP1 maintains chromosome stability in limb bud mesenchymal cells during bone development

Cell Signal. 2024 May 8:120:111222. doi: 10.1016/j.cellsig.2024.111222. Online ahead of print.

Authors

Minjun Huang¹, Bochong Chen², Xiaoli Chen², Tianxiao Liu², Siying Liang², Hongling Hu³, Xiaochun Bai⁴, Yan Gong⁵

Affiliations

¹ Department of Spine Surgery, The Tenth Affiliated Hospital of Southern Medical University (Dongguan People's Hospital), Dongguan 523059, China; Department of Orthopaedics, Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, Orthopedic Hospital of Guangdong Province, The Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, China.
² Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China.
³ Department of Trauma and Joint Surgery, Shunde Hospital, Southern Medical University, Foshan 528399, China.
⁴ Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China. Electronic address: baixc15@smu.edu.cn.
⁵ Department of Spine Surgery, The Tenth Affiliated Hospital of Southern Medical University (Dongguan People's Hospital), Dongguan 523059, China; Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China. Electronic address: gongyan0702@smu.edu.cn.

PMID: 38729327
DOI: 10.1016/j.cellsig.2024.111222

Abstract

Background: Bone development involves the rapid proliferation and differentiation of osteogenic lineage cells, which makes accurate chromosomal segregation crucial for ensuring cell proliferation and maintaining chromosomal stability. However, the mechanism underlying the maintenance of chromosome stability during the rapid proliferation and differentiation of Prx1-expressing limb bud mesenchymal cells into osteoblastic precursor cells remains unexplored.

Methods: A transgenic mouse model of RanGAP1 knockout of limb and head mesenchymal progenitor cells was constructed to explore the impact of RanGAP1 deletion on bone development by histomorphology and immunostaining. Subsequently, G-banding karyotyping analysis and immunofluorescence staining were used to examine the effects of RanGAP1 deficiency on chromosome instability. Finally, the effects of RanGAP1 deficiency on chromothripsis and bone development signaling pathways were elucidated by whole-genome sequencing, RNA-sequencing, and qPCR.

Results: The ablation of RanGAP1 in limb and head mesenchymal progenitor cells expressing Prx1 in mice resulted in embryonic lethality, severe cartilage and bone dysplasia, and complete loss of cranial vault formation. Moreover, RanGAP1 loss inhibited chondrogenic or osteogenic differentiation of mesenchymal stem cells (MSCs). Most importantly, we found that RanGAP1 loss in limb bud mesenchymal cells triggered missegregation of chromosomes, resulting in chromothripsis of chromosomes 1q and 14q, further inhibiting the expression of key genes involved in multiple bone development signaling pathways such as WNT, Hedgehog, TGF-β/BMP, and PI3K/AKT in the chromothripsis regions, ultimately disrupting skeletal development.

Conclusions: Our results establish RanGAP1 as a critical regulator of bone development, as it supports this process by preserving chromosome stability in Prx1-expressing limb bud mesenchymal cells.

Keywords: Bone development; Chromosomal instability; Mesenchymal stem cells; RanGAP1.