Biology subjects

Felix Velez, N. E.

Publications and source records attributed to Felix Velez, N. E..

3 recordsLinked to original sources

bioRxiv2026

Transforming Growth Factor β1 Modulates Sex Differences in Cardiac Myofibroblast Activation on Hydrogel Biomaterials

Cardiac fibrosis is a pathological process in which the myocardium stiffens due to the overproduction of extracellular matrix (ECM) proteins. Cardiac fibroblasts activate to myofibroblasts in response to the inflammatory cytokine transforming growth factor beta1 (TGF-{beta}1) to promote fibrotic scarring. Biological sex also influences cardiac fibrosis progression and patient outcomes, where males exhibit increased fibrotic scarring after acute inflammation relative to females. At the cellular level, sex differences in TGF-{beta}1-mediated cardiac myofibroblast activation processes have not been clearly defined. We hypothesized that TGF-{beta}1 would cause sex-specific cardiac myofibroblast activation levels and alter the secretion of bioactive molecules to modulate sex differences in cardiac fibrosis. Primary left ventricle cardiac fibroblasts were isolated from male and female C57BL/6J mice and cultured on hydrogel biomaterials mimicking native myocardial ECM stiffness and treated with TGF-{beta}1 and/or the TGF-{beta}1 receptor inhibitor SD208. Male myofibroblasts exhibited increased -SMA stress fiber formation, increased SMAD2/3 localization, and greater resistance to SD208 inhibition compared to female myofibroblasts on hydrogels at various time points tested. Sex differences in relative secreted cytokine abundance were also determined, with male CFs secreting increased vascular endothelial growth factor (VEGF) and female CFs producing increased periostin and fibroblast growth factor 21 in response to TGF-{beta}1. Our findings establish that TGF-{beta}1 mediates sex differences in cardiac myofibroblast activation on hydrogels and secreted factors that may modulate the myocardial microenvironment. Our work underscores the importance of using hydrogels as cell culture platforms to recapitulate sex-specific cardiac fibrosis phenotypes as a steppingstone towards identifying sex-dependent therapeutic interventions for cardiac fibrosis.

bioengineering↗

bioRxiv2026

Circulating biomarkers in serum from aortic valve stenosis patients predict sex-specific drug responses in valve myofibroblasts

Aortic valve stenosis (AVS) is a prevalent, sexually dimorphic cardiovascular disease characterized by fibro-calcification of the aortic valve leaflet. Sex differences in AVS arise in part from sexually dimorphic serum composition that differentially regulate valvular interstitial cell (VIC) myofibroblast activation. However, how individual serum factors contribute to sex-specific drug responses targeting VIC myofibroblast activation remains unknown. Here, we integrate serum proteomic profiling with in vitro drug screening using hydrogel biomaterials to identify sex-specific regulators of antifibrotic drug efficacy. We found that Insulin-like Growth Factor Binding Protein 2 (IGFBP2) serum levels are associated with resistance to the antifibrotic drug Evogliptin only in female VICs cultured with female AVS serum. This mechanism is driven by IGFBP2-mediated activation of Rho/ROCK and focal adhesion kinase signaling pathways that counteract Evogliptin treatment. Our findings reveal a sex-specific, serum-mediated mechanism of Evogliptin resistance and highlight IGFBP2 as a candidate biomarker for stratifying female AVS patients for Evogliptin treatment. More broadly, these findings underscore the importance of incorporating sex-stratified biomarker analyses into AVS therapeutic development to improve patient-specific treatment recommendations.

bioengineering↗

bioRxiv2024

Secreted cytokines from inflammatory macrophages modulate sex differences in valvular interstitial cells on hydrogel biomaterials

Patients with aortic valve stenosis (AVS) experience fibrosis and/or calcification in valve tissue, which leads to heart failure if left untreated. Inflammation is a hallmark of AVS and secreted cytokines from pro-inflammatory macrophages are thought to contribute to valve fibro-calcification by driving the activation of valvular interstitial cells (VICs) to myofibroblasts. However, the molecular mechanisms by which inflammatory cytokines differentially regulate myofibroblast activation as a function of biological sex are not fully defined. Here, we developed an in vitro hydrogel culture platform to culture male and female valvular interstitial cells (VICs) and characterize the sex-specific effects of inflammatory cytokines on VIC activation to myofibroblasts and osteoblast-like cells. Our data reveal that tumor necrosis factor alpha (TNF-) modulates female-specific myofibroblast activation via MAPK/ERK signaling, nuclear chromatin availability, and osteoblast-like differentiation via RUNX2 nuclear localization. Collectively, hydrogel biomaterials as cell culture platforms are critical for distinguishing sex differences in cellular phenotypes.

bioengineering↗