What question did this study set out to answer?

This research investigates the role of the TGF-β1/CDK5 signaling pathway in endothelial-to-mesenchymal transition (EndMT) and explores the potential of CDK5 inhibitors for reversing these changes.

May 20, 2026

B65-05 Inhibition of Tgf-β1/cdk5 Signaling Axis Reverses Endothelial-to-mesenchymal Transition

Key Points

This research investigates the role of the TGF-β1/CDK5 signaling pathway in endothelial-to-mesenchymal transition (EndMT) and explores the potential of CDK5 inhibitors for reversing these changes.
Utilized mouse lung endothelial cells from Tg(TIE2GFP)287Sato/J mice to assess purity and morphology.
Induced EndMT with TGF-β1 and evaluated changes in morphology and mesenchymal markers using various CDK5 inhibitors.
Performed single-cell RNA sequencing for a detailed transcriptomic analysis throughout transition stages.
Elevated CDK5 expression associated with pulmonary arterial hypertension (PAH) in SuHx5 rat lungs.
TGF-β1 treatment led to significant phenotypic changes, increased proliferation, and upregulation of mesenchymal markers such as αSMA, SM22α, Calponin.
Inhibition of CDK5 notably reversed EndMT and restored endothelial function, marked by reduced mesenchymal markers and enhanced angiogenesis.

Abstract

Abstract Rationale Vascular remodeling in PAH involves endothelial-to-mesenchymal transition (EndMT), characterized by phenotypic shift, increased proliferation, loss of endothelial markers, and acquisition of mesenchymal markers. Although in vitro models utilize TGF-β1 to induce these changes, there are limited strategies available for phenotypic reversal and functional restoration. Hypothesis Targeting TGF-β1 CDK5 axis, novel reversible CDK5 small molecule inhibitor can effectively restrict EndMT and restore endothelial function. Methods Mouse lung endothelial cells from Tg(TIE2GFP)287Sato/J mice were validated for purity via morphology and endothelial markers. EndMT was induced with TGF-β1 at multiple time points, assessing morphological and mesenchymal marker changes. CDK5 expression was examined in WT and SuHx5 rat lungs. TGF-β1-treated cells were combined with various CDK5 inhibitors, including a novel reversible small molecule, to evaluate CDK5’s role in EndMT. Functional assays included proliferation, angiogenesis, and collagen gel contraction. Single-cell RNA sequencing was performed across transition stages for detailed transcriptomic analysis. Results Elevated CDK5 expression in SuHx5 rat lungs indicates its role in PAH. TGF-β1 induced phenotypic transition, characterized by fibroblast-like morphology, increased proliferation, and upregulation of mesenchymal markers (αSMA, SM22α, Calponin). CDK5 inhibition, especially with a reversible inhibitor, suppressed these changes, restoring endothelial function by reducing mesenchymal markers and enhancing angiogenesis while decreasing collagen contraction. scRNA-seq revealed phenotypic reversal of EndMT through CDK5 inhibition. Conclusion CDK5 is a key regulator of EndMT in PAH. A novel small molecule inhibitor of CDK5 effectively suppresses EndMT and restores endothelial function in TGF-β1-stimulated mLECs, supporting CDK5 inhibition as a potential therapeutic strategy for vascular diseases, including PAH. This abstract is funded by: NIH

Mark Helpful

Bookmark

Relay