Biology subjects

DeVeaux, S. A.

Publications and source records attributed to DeVeaux, S. A..

4 recordsLinked to original sources

bioRxiv2025

Exogenous Delivery of Sphingomyelinase Mediates Mesenchymal Stromal Cell-Extracellular Vesicle Biogenesis, Alters Cargo Sorting, and Therapeutic Potency in vitro

Mesenchymal stromal cells (MSCs) exert regenerative and immunomodulatory effects largely through secreted paracrine factors and extracellular vesicles (EVs), which transfer proteins, lipids, and nucleic acids to recipient cells. Lipid composition critically influences EV stability, uptake, and bioactivity. Sphingomyelinase (SMase), an enzyme that hydrolyzes sphingomyelin into ceramide, regulates EV biogenesis by inducing membrane curvature and initiating inward membrane budding. Here, MSCs were treated with SMase, and EVs were isolated and characterized by nanoparticle tracking analysis, miRNA sequencing, lipidomics, and proteomics. SMase treatment increased EV yield and altered lipid, protein, and miRNA cargo linked to TNF- signaling, wound healing, and angiogenesis. Functionally, SMase-EVs suppressed TNF- in macrophages, showed trending increased HUVEC tubular formation, and altered T-cell populations following local delivery in a critical murine oral wound defect model. These findings highlight how enzymatic lipid remodeling modifies MSC-EVs, enhancing their therapeutic potential and informing strategies for optimized EV-based therapies and scalable production.

bioengineering↗

bioRxiv2025

Sphingomyelinase Licensing of Mesenchymal Stromal Cells Alters Lipid and Protein Metabolites for Immunomodulation

Mesenchymal stromal cells (MSCs) are widely studied for their immunomodulatory and tissue reparative capabilities, but clinical translation has been hampered by inconsistent efficacy and limited standardization in manufacturing. While cytokine-based priming methods, such as interferon-gamma (IFN-{gamma}) stimulation, have shown promise in enhancing MSC potency, alternative approaches targeting distinct biological metabolism integral to secretome and membrane architecture have not been explored in MSCs. In this study, we investigate sphingomyelinase (SMase), an enzyme that generates ceramide from sphingomyelin, as a novel lipid-based priming strategy to modulate MSC function. Here, human MSCs were treated with SMase and high-content imaging and morphological profiling revealed that SMase-treated cells adopted a phenotype overlapping with IFN-{gamma}-licensed MSCs, including increased cell compactness and solidity. Lipidomic analysis showed broad alterations in sphingolipid species, and dynamic flux estimation (DFE) modeling predicted distinct metabolic shifts in SMase-treated cells compared to untreated controls. These changes were sustained up to 35 hours post-stimulation, indicating stable metabolic reprogramming. SMase priming also altered the MSC secretome, enriching for factors implicated in immune regulation. Functionally, SMase-primed MSCs retained the ability to suppress T-cell activation and promote anti-inflammatory macrophage phenotypes. Collectively, these findings demonstrate that SMase stimulation induces a durable, immunomodulatory-like state in MSCs through coordinated changes in lipid metabolism and secretory activity. This lipid-centric priming approach represents a promising alternative to cytokine-based licensing strategies and may support therapeutic MSC products.

bioengineering↗

bioRxiv2024

Neuroinflammation underlies the development of social stress induced cognitive deficit in sickle cell disease.

Cognitive deficit is a debilitating complication of SCD with multifactorial pathobiology. Here we show that neuroinflammation and dysregulation in lipidomics and transcriptomics profiles are major underlying mechanisms of social stress-induced cognitive deficit in SCD. Townes sickle cell (SS) mice and controls (AA) were exposed to social stress using the repeat social defeat (RSD) paradigm concurrently with or without treatment with minocycline. Mice were tested for cognitive deficit using novel object recognition (NOR) and fear conditioning (FC) tests. SS mice exposed to RSD without treatment had worse performance on cognitive tests compared to SS mice exposed to RSD with treatment or to AA controls, irrespective of their RSD or treatment disposition. Additionally, compared to SS mice exposed to RSD with treatment, SS mice exposed to RSD without treatment had significantly more cellular evidence of neuroinflammation coupled with a significant shift in the differentiation of neural progenitor cells towards astrogliogenesis. Additionally, brain tissue from SS mice exposed to RSD was significantly enriched for genes associated with blood-brain barrier dysfunction, neuron excitotoxicity, inflammation, and significant dysregulation in sphingolipids important to neuronal cell processes. We demonstrate in this study that neuroinflammation and lipid dysregulation are potential underlying mechanisms of social stress-related cognitive deficit in SS mice. Key PointsO_LINeuroinflammation and lipid dysfunction are potential underlying mechanisms of social stress-related cognitive deficit in SCD patients. C_LIO_LIMitigating or ameliorating the impact of cognitive deficits in SCD needs to consider the biological changes already created by exposure to social stress. C_LI Novelty of our FindingsWe show for the first time, that neuroinflammation along with changes in the brain lipidome and transcriptome, are underlying biological mechanism contributing to the development and potentially progression of cognitive impairment among sickle cell patients. These findings also provide for the first time, a mechanistic basis for an earlier reported observation of a higher likelihood of having lower intelligence quotient scores among children with sickle cell disease exposed to social stress in the form of low parental socioeconomic status.

neuroscience↗

bioRxiv2021

Characterizing Human Mesenchymal Stromal Cells Immune Modulatory Potency Using Targeted Lipidomic Profiling of Sphingolipids

Cell therapies are expected to increase over the next decade due to increasing demand for clinical applications. Mesenchymal stromal cells (MSCs) have been explored to treat a number of diseases, with some successes in early clinical trials. Despite early successes, poor MSC characterization results in lessened therapeutic capacity once in vivo. Here, we characterized bone-marrow (BM), adipose derived and umbilical cord tissue MSCs sphingolipids (SLs), a class of bioactive lipids, using liquid chromatography - tandem mass spectrometry. We found ceramide levels differed based upon donors sex in BM-MSCs. We detected fatty acyl chain variants in MSCs from all 3 sources. Linear discriminant analysis revealed that MSCs separated based on tissue source. Principal component analysis showed IFN-{gamma} primed and unstimulated MSCs separated according to their SL signature. Lastly, we detected higher ceramide levels in low IDO MSCs, indicating sphingomeylinase or ceramidase enzymatic activity may be involved in their immune potency.

bioengineering↗