Stem cell-based modeling and single-cell multiomics reveal gene-regulatory mechanisms underlying human skeletal...

Area of Science:

• Developmental Biology
• Stem Cell Biology
• Genomics

Background:

• The molecular mechanisms governing human skeletal development are not fully understood.
• The skeleton's crucial roles in locomotion, endocrine functions, and hematopoiesis necessitate further investigation into its development.

Purpose of the Study:

• To establish an integrative in vitro and in vivo model for studying human skeletal development.
• To elucidate the molecular mechanisms and gene regulatory networks (GRNs) underlying human osteogenesis.

Main Methods:

• Induction of sclerotome from human pluripotent stem cells in vitro.
• In vivo endochondral bone formation by implanting induced sclerotome in immunodeficient mice.
• Histological, scRNA-seq, and single-cell multiome analyses to characterize cellular composition and gene regulation.

Main Results:

• The model successfully recapitulated human endochondral ossification, yielding human skeletal cells within mouse tissues.
• Skeletal cell types and developmental trajectories mirrored those observed in human embryos.
• Dynamic chromatin accessibility changes and cell-type-specific gene-regulatory networks (GRNs) were identified, highlighting ZEB2's potential role in human osteogenesis.

Conclusions:

• The developed model provides a valuable platform for investigating human skeletal development.
• Key components of gene regulatory networks (GRNs) in human osteogenesis have been identified.
• The study offers insights into the molecular underpinnings of skeletal formation and potential therapeutic targets.