Abstract
Background The development of collateral arteries after a myocardial infarction (MI) was intensively studied, while the mechanism by which pericytes (PCs) contribute to arteriologenesis remains unexplored. This study aimed to 1) investigate if cardiac PCs gain functional features of contractile vascular smooth muscle cells (VSMCs) in vitro, and 2) determine if this potential can be evoked pharmacologically to encourage heart arteriologenesis in vivo.
Methods PCs were immunosorted as CD31neg/CD34pos cells from human and mouse hearts. Contractile reprogramming was induced by either depletion of growth factors or addition of PD0325901, a clinically available MEK inhibitor. Next generation RNA-Sequencing was performed in naïve and differentiated human PCs to assess the whole-transcriptome profile. Three in vivo studies were conducted in C57BL6/J mice to determine: 1) the ability of human PCs to promote arteriole formation when implanted subcutaneously within PD0325901-containing Matrigel plugs, 2) the effect of orally administered PD0325901 on the arteriole density of normoperfused hearts, and 3) the possibility of promoting capillary formation and muscularization of the infarcted heart through the same pharmacological approach.
Results Removal of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) from the culture medium induced the differentiation of PCs into contractile VSMC-like cells. Because both growth factors induce the extracellular signal-regulated kinase 1/2 (ERK1/2) signalling, we attempted to induce PC differentiation in vitro and in vivo using PD0325901. RNA-sequencing revealed that differentiated PCs were enriched in transcripts associated with smooth muscle contraction and biological function. PD0325901-treated PCs rapidly acquired antigenic and functional features of contractile VSMCs in vitro. Moreover, human PCs formed new arterioles when implanted subcutaneously within PD0325901-containing Matrigel plugs in mice. Oral administration of PD0325901 for two weeks increased the density and expression of contractile proteins in small-calibre arterioles of the murine heart, thereby increasing myocardial perfusion. Similarly, PD0325901 induced reparative arteriologenesis and capillarization, reduced the scar, and improved left ventricular performance in a murine model of MI.
Conclusion We propose a novel method to promote the heart vascularization through the pharmacological modulation of resident mural cells. This novel approach could have an immediate impact on the treatment of coronary artery disease.
What is new?
Human myocardial pericytes have intrinsic vascular plasticity that can be pharmacologically evoked using PD0325901, a clinically available MEK inhibitor.
In mice, the pharmacological inhibition of ERK1/2 signalling, by the oral administration of PD0325901 for 2 weeks, encouraged the heart arteriologenesis through pericyte differentiation.
In a preclinical mouse model of myocardial infarction, the oral administration of PD0325901 for 2 weeks induced reparative arteriologenesis and capillarization, reduced the scar, and improved left ventricular performance.
What are the clinical implications?
This novel drug-based therapeutic approach is readily available to all patients.
Therefore, it could have an immediate clinical impact for the treatment of coronary artery disease and other heart conditions associated with deficient coronary vascularization.
- Arteriologenesis
- Capillarization
- Cardiac pericyte
- ERK1/2
- PD0325901
- Vascular smooth muscle cell
- Myocardial infarction
Competing Interest Statement
The authors have declared no competing interest.
Frequently used abbreviations
- Non-standard abbreviations and acronyms
- bFGF
- basic fibroblast growth factor
- DAPI
- 4′,6-diamidino-2-phenylindole
- EGF
- epidermal growth factor
- FBS
- Foetal bovine serum
- IGF1
- insulin-like growth factor 1
- PBS
- phosphate buffer saline
- PC
- pericyte
- PFA
- paraformaldehyde
- VEGF
- vascular endothelial growth factor
- VSMC
- vascular smooth muscle cell
- ANGPT
- angiopoietin
- ANOVA
- analysis of variance
- ATP
- adenosine triphosphate
- CAECs
- coronary artery endothelial cells
- CALP
- smooth muscle calponin
- cTn-I
- cardiac troponin I
- DEGs
- differentially expressed genes
- DMSO
- dimethyl sulfoxide
- DPCs
- PD0325901-differentiated PCs
- ECGM2
- growth factor enriched pericyte medium
- ECM
- extracellular matrix
- EGFR
- EGF Receptor
- ELK1
- E26 transformation-specific (ETS) Like-1 protein
- ERK1/2
- extracellular signal-regulated kinase 1/2
- ET-1
- endothelin-1
- FGFR
- FGF Receptor
- GFs
- growth factors
- GO
- gene ontology
- HGF
- hepatocyte growth factor
- LAD
- left anterior descending
- LV
- left ventricle
- LVEF
- LV ejection fraction
- MEK1/2
- dual specificity mitogen-activated protein kinase kinase
- MEKi
- MEK inhibitor
- MI
- myocardial infarction
- NG2
- neuron-glial antigen 2
- NM-MyoIIB
- non-muscle myosin IIB
- PCs
- pericytes
- PDGF-BB
- platelet-derived growth factor-BB
- PDGFRα
- platelet-derived growth factor receptor alpha
- PDGFRβ
- platelet-derived growth factor receptor beta
- p-ERK1/2
- phospho-ERK1/2
- PPI
- protein-protein interaction
- SDF-1α
- stromal derived factor-1 alpha
- SM
- smooth muscle
- SM22α
- smooth muscle protein 22-alpha
- SMA-α
- Smooth Muscle Actin-alpha
- SM-MHC
- smooth muscle myosin heavy chain
- TCF21
- transcription factor 21
- TUNEL
- terminal deoxynucleotidyl transferase dUTP nick end labelling
- VSMCs
- vascular smooth muscle cells