PDGF-BB-mediated activation of CREB in vascular smooth muscle cells alters cell cycling via Rb, FoxO1 and p27kip1

Raissa Perrault; Peter Molnar; Jenna Poole; Peter Zahradka

doi:10.1016/j.yexcr.2021.112612

PDGF-BB-mediated activation of CREB in vascular smooth muscle cells alters cell cycling via Rb, FoxO1 and p27^kip1

Exp Cell Res. 2021 Jul 1;404(1):112612. doi: 10.1016/j.yexcr.2021.112612. Epub 2021 Apr 22.

Authors

Raissa Perrault¹, Peter Molnar², Jenna Poole³, Peter Zahradka⁴

Affiliations

¹ Department of Physiology and Pathophysiology, University of Manitoba, Canada; Molecular Physiology Laboratory, St. Boniface Albrechtsen Research Centre, Canada; Department of Experimental Sciences, Université de Saint Boniface, Winnipeg, Manitoba, Canada.
² Department of Physiology and Pathophysiology, University of Manitoba, Canada; Molecular Physiology Laboratory, St. Boniface Albrechtsen Research Centre, Canada.
³ Molecular Physiology Laboratory, St. Boniface Albrechtsen Research Centre, Canada.
⁴ Department of Physiology and Pathophysiology, University of Manitoba, Canada; Molecular Physiology Laboratory, St. Boniface Albrechtsen Research Centre, Canada. Electronic address: peterz@sbrc.ca.

PMID: 33895117
DOI: 10.1016/j.yexcr.2021.112612

Abstract

Introduction & aim: The vascular response to injury leads to the secretion of several factors, including platelet-derived growth factor (PDGF-BB). PDGF-BB stimulates smooth muscle cell (SMC) conversion to the synthetic phenotype, thereby enhancing proliferation and migration, and contributing to neointimal hyperplasia. Likewise, the cAMP response element binding protein (CREB) transcription factor has been shown to mediate SMC proliferation in response to various mitogens. We therefore investigated the contribution of CREB to PDGF-BB-dependent proliferation of SMCs with the intention of identifying signaling pathways involved both up and downstream of CREB activation.

Methods & results: Treatments were performed on vascular SMCs from a porcine coronary artery explant model. The role of CREB was examined via adenoviral expression of a dominant-negative CREB mutant (kCREB) as well as inhibition of CREB binding protein (CBP). Involvement of the p27^kip1 pathway was determined using a constitutively expressing p27^kip1 adenoviral vector. PDGF-BB stimulated transient CREB phosphorylation on Ser-133 via ERK1/2-, PI3-kinase- and Src-dependent pathways. Expression of kCREB decreased PDGF-BB-dependent cell proliferation. PCNA expression and Rb phosphorylation were also inhibited by kCREB. These cell cycle proteins are controlled via p27^kip1 expression in response to CREB-dependent post-translational modification of FoxO1. kCREB had no effect on Cyclin D1 expression, but did prevent PDGF-BB-induced Cyclin D1 nuclear translocation. An interaction inhibitor of CBP confirmed that Cyclin D1 is downstream of PDGF-BB and CREB.

Conclusion: CREB phosphorylation is required for SMC proliferation in response to PDGF-BB. This phenotypic change requires CBP and is mediated by Cyclin D1 and p27^kip as a result of changes in FoxO1 activity.

Keywords: Forkhead; Proliferation; Smooth muscle; cAMP-dependent response element binding protein.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Cell Cycle / physiology*
Cell Division / physiology
Cell Proliferation / physiology
Cyclic AMP Response Element-Binding Protein / metabolism
Forkhead Box Protein O1 / metabolism*
Gene Expression Regulation / physiology*
Muscle, Smooth, Vascular / metabolism*
Myocytes, Smooth Muscle / metabolism*
Proto-Oncogene Proteins c-sis / metabolism
Swine

Substances

Cyclic AMP Response Element-Binding Protein
Forkhead Box Protein O1
Proto-Oncogene Proteins c-sis