Locus-Conserved Circular RNA cZNF292 Controls Endothelial Cell Flow Responses

Area of Science:

• Molecular Biology
• Genetics
• Cell Biology

Background:

• Circular RNAs (circRNAs) are emerging regulatory RNAs with largely unknown in vivo functions.
• Genetic inactivation of circRNAs is challenging, hindering studies on their physiological roles and conservation.
• This study aimed to identify conserved circRNAs for functional analysis through genetic deletion.

Purpose of the Study:

• To identify locus-conserved circRNAs between mice and humans.
• To investigate the in vivo function of conserved circRNAs, specifically cZfp292.
• To elucidate the molecular mechanism underlying circRNA-mediated endothelial cell regulation.

Main Methods:

• Combined RNA-sequencing data with circRNA databases to identify conserved circRNAs.
• Utilized CRISPR/Cas9 for genetic depletion of circRNA cZfp292 in vivo and in vitro.
• Employed RNA-affinity purification and mass spectrometry to identify interacting proteins.
• Investigated the role of protein SDOS and its binding partner Syndecan-4.

Main Results:

• Identified locus-conserved circRNAs between mice and humans.
• Genetic depletion of cZfp292 altered endothelial morphology and aortic flow alignment in vivo.
• cZNF292 depletion in vitro abolished laminar flow-induced changes in endothelial cell orientation and focal adhesion.
• Discovered specific interaction between cZNF292 and protein SDOS.
• SDOS or Syndecan-4 silencing, or disruption of their binding site, recapitulated cZfp292 knockout phenotypes.

Conclusions:

• Revealed a novel role for cZNF292/cZfp292 in endothelial cell responses to blood flow.
• Demonstrated that cZNF292 influences endothelial cell shape and cytoskeletal organization.
• Established a molecular mechanism involving SDOS and Syndecan-4 in circRNA-mediated flow responses.