Controlled Growth Factor Delivery and Cyclic Stretch Induces a Smooth Muscle Cell-like Phenotype in Adipose-Derived Stem Cells

Abstract

Adipose-derived stem cells (ASCs) are an abundant and easily accessible multipotent stem cell source with potential application in smooth muscle regeneration strategies. In 3D collagen hydrogels, we investigated whether sustained release of growth factors (GF) PDGF-AB and TGF-β1 from GF-loaded microspheres could induce a smooth muscle cell (SMC) phenotype in ASCs, and if the addition of uniaxial cyclic stretch could enhance the differentiation level. This study demonstrated that the combination of cyclic stretch and GF release over time from loaded microspheres potentiated the differentiation of ASCs, as quantified by protein expression of early to late SMC differentiation markers (SMA, TGLN and smooth muscle MHC). The delivery of GFs via microspheres produced large ASCs with a spindle-shaped, elongated SMC-like morphology. Cyclic strain produced the largest, longest, and most spindle-shaped cells regardless of the presence or absence of growth factors or the growth factor delivery method. Protein expression and cell morphology data confirmed that the sustained release of GFs from GF-loaded microspheres can be used to promote the differentiation of ASCs into SMCs and that the addition of uniaxial cyclic stretch significantly enhances the differentiation level, as quantified by intermediate and late SMC markers and a SMC-like elongated cell morphology.

Cell morphology as a biological fingerprint of chondrocyte phenotype in control and inflammatory conditions

“…the expression of COL2A1 and IL-6 ( Figures 2 , 4 ), which highlights that small changes in morphology cannot be dismissed because of their small scale. In this context, we have reported comparable findings in MSCs induced by biomechanical forces ( 45 – 47 ), biophysical stimuli including biomaterials and nanoscale surface stiffness ( 46 ), implant surface topography ( 48 ) and growth factors ( 45 ), highlighting that small changes in morphology are related to large phenotypic effects. In term of the underlying mechanisms of cytokine-mediated cell morphology and associated gene effects, we refer the interested reader to our recent review ( 67 ) that discusses how inflammatory cytokines such as IL-1β and other factors regulate articular chondrocyte phenotype through the cytoskeleton and the signaling processes that originate from or converge on the cytoskeleton.…”

“…A solidity value of 1 signifies a solid cell, and a value less than 1 signifies a cell with an irregular boundary or a cell containing holes. We had introduced this panel of quantitative shape descriptors originally in the context of mesenchymal stromal cell (MSC) experiments ( 30 , 45 , 46 , 47 , 48 , 75 ) and used the panel here, which allowed testing for correlations between multiple aspects of cell shape with experimental conditions, phenotype, donor and macroscopic grade.…”

“…Indeed, the morphological status of cells can be linked to fundamental cell functions ( 33 ) such as cell proliferation ( 34 ), cell differentiation ( 35 – 39 ), cell cycle progression ( 40 ), cell spreading and cell migration ( 41 ), the invasive potential of cancerous cells ( 42 ), as well as inflammation ( 43 , 44 ). Thus, the morphological status of cells can be utilized as a “morphological fingerprint” ( 30 ) and quantifying single cell morphology using high-throughput techniques can hence be useful for describing and better understanding the impact of biochemical ( 45 ) and biophysical ( 45 – 48 ) stimuli on cells.…”

Engineering Smooth Muscle to Understand Extracellular Matrix Remodeling and Vascular Disease

“…Cyclic strain is a standard method of mechanical stimulation applied to cell culture constructs to induce the desired SMC behavior [ 44 , 45 , 46 ]. In one study, incrementally increasing the frequency of cyclic stretch resulted in a higher degree of SMC alignment and denser collagen structure but decreased the expression of many ECM proteins and proteases compared to unstretched controls [ 47 ].…”

Tissue Engineering as a Promising Treatment for Glottic Insufficiency: A Review on Biomolecules and Cell-Laden Hydrogel

“…Growth factor incorporation will increase the bioactivity of the hydrogel [ 119 ]. For instance, Walters and colleagues demonstrated [ 120 ] that combining platelet-derived growth factor AB (PDGF-AB) and TGF-1 in collagen hydrogel promotes the differentiation of ASCs into smooth muscle cells. The thermosensitive heparin-poloxamer hydrogel containing bFGF and NGF enhances Schwann cell proliferation via the PI3K/Akt, JAK/STAT and MAPK/ERK signalling pathways [ 121 ].…”