Histone Deacetylase 3 Unconventional Splicing Mediates Endothelial-to-mesenchymal Transition through Transforming Growth Factor β2

Lingfang Zeng,Gang Wang,Dario Ummarino,Andriana Margariti,Qihe Xu,Qingzhong Xiao,Wen Wang,Zhongyi Zhang,Xiaoke Yin,Manuel Mayr,Gillian Cockerill,Julie Yi-Shuan Li,Shu Chien,Yanhua Hu,Qingbo Xu

doi:10.1074/jbc.m113.463745

Abstract

Histone deacetylase 3 (HDAC3) plays a critical role in the maintenance of endothelial integrity and other physiological processes. In this study, we demonstrated that HDAC3 undergoes unconventional splicing during stem cell differentiation. Four different splicing variants have been identified, designated as HD3α, -β, -γ, and -δ, respectively. HD3α was confirmed in stem cell differentiation by specific antibody against the sequences from intron 12. Immunofluorescence staining indicated that the HD3α isoform co-localized with CD31-positive or α-smooth muscle actin-positive cells at different developmental stages of mouse embryos. Overexpression of HD3α reprogrammed human aortic endothelial cells into mesenchymal cells featuring an endothelial-to-mesenchymal transition (EndMT) phenotype. HD3α directly interacts with HDAC3 and Akt1 and selectively activates transforming growth factor β2 (TGFβ2) secretion and cleavage. TGFβ2 functioned as an autocrine and/or paracrine EndMT factor. The HD3α-induced EndMT was both PI3K/Akt- and TGFβ2-dependent. This study provides the first evidence of the role of HDAC3 splicing in the maintenance of endothelial integrity.

Highlights

Endothelial-to-mesenchymal transition (EndMT) is involved in embryonic cardiovascular development
Histone deacetylase 3 (HDAC3) undergoes unconventional splicing during stem cell differentiation, which contributes to EndMT
We demonstrated that HDAC3 undergoes unconventional splicing during stem cell differentiation

Summary

Conclusion

HDAC3 unconventional splicing may modulate endothelial cell plasticity. We demonstrated that HDAC3 undergoes unconventional splicing during stem cell differentiation. HD3␣ directly interacts with HDAC3 and Akt and selectively activates transforming growth factor ␤2 (TGF␤2) secretion and cleavage. This study provides the first evidence of the role of HDAC3 splicing in the maintenance of endothelial integrity. Several signaling pathways are reported to be involved in EndMT, such as transforming growth factor ␤ (TGF␤) binding and Notch and Akt activation dpc, days postcoitus; HDAC, histone deacetylase; ES, embryonic stem; HAEC, human aortic endothelial cell; DM, differentiation medium; MOI, multiplicity of infection; DES, differentiated embryonic stem; Ad, adenovirus. We found that HDAC3 undergoes unconventional splicing during embryonic stem (ES) cell differentiation and development. Overexpression of the splicing isoform of HDAC3, HD3␣, reprogrammed ECs into mesenchymal cells

EXPERIMENTAL PROCEDURES

RESULTS

DISCUSSION