Biology subjects

Hulsmans, M.

Publications and source records attributed to Hulsmans, M..

3 recordsLinked to original sources

bioRxiv2025

Bone marrow mesenchymal stromal cells mediate cellular inflammation in HFpEF

During the genesis of heart failure, the myocardium recruits an abundance of bone marrow-derived leukocytes, primarily monocytes, with various disease-promoting functions. Increased hematopoiesis fuels these unfavorable changes in cardiac leukocyte origin, number and phenotype. Here we examine hematopoietic niche cells, which regulate blood progenitor proliferation and systemic monocyte supply, in obese, hypertensive mice that develop heart failure with preserved ejection fraction (HFpEF). Single cell transcriptomics revealed that in HFpEF, stromal bone marrow niche cells expand and respond strongly to IFN{gamma}. Deleting the IFN{gamma} receptor in stromal cells of Prrx1CreERT2;Ifngr1fl/fl mice reduced hematopoietic progenitor proliferation and systemic monocytes in both the steady state and HFpEF and also increased the canonical hematopoietic maintenance factor CXCL12, resulting in reduced fibrosis and improved diastolic function. CD8+ T cells in adipose tissue were a major source of IFN{gamma} in mice with HFpEF; their depletion restored CXCL12 expression and lowered monocyte numbers. ScRNA-seq in mice with ischemic heart disease uncovered a diverging marrow response. These data indicate that in HFpEF, adipose tissue, bone marrow and adaptive and innate immune cells conspire to expand harmful macrophage subsets in the heart.

immunology↗

bioRxiv2024

Therapeutic Spp1 silencing in TREM2+ cardiac macrophages suppresses atrial fibrillation

Atrial fibrillation (AFib) and the risk of its lethal complications are propelled by fibrosis, which induces electrical heterogeneity and gives rise to reentry circuits. Atrial TREM2+ macrophages secrete osteopontin (encoded by Spp1), a matricellular signaling protein that engenders fibrosis and AFib. Here we show that silencing Spp1 in TREM2+ cardiac macrophages with an antibody-siRNA conjugate reduces atrial fibrosis and suppresses AFib in mice, thus offering a new immunotherapy for the most common arrhythmia.

immunology↗

bioRxiv2021

Genetic Inhibition of Serum Glucocorticoid Kinase 1 Prevents Obesity-related Atrial Fibrillation

RationaleGiven its rising prevalence in both the adult and pediatric populations, obesity has become an increasingly important risk factor in the development of atrial fibrillation. However, a better mechanistic understanding of obesity-related atrial fibrillation is required. Serum glucocorticoid kinase 1 (SGK1) is a kinase positioned downstream of multiple obesity-related pathways, and prior work has shown a pathologic role for SGK1 signaling in ventricular remodeling and arrhythmias. ObjectiveTo determine the mechanistic basis of obesity associated atrial fibrillation and explore the therapeutic potential of targeting SGK1 in this context. Methods and ResultsWe utilized a mouse model of diet induced obesity to determine the atrial electrophysiologic effects of obesity using electrophysiologic studies, optical mapping, and biochemical analyses. In C57BL/6J mice fed a high fat diet, there was upregulation of SGK1 signaling along with an increase in AF inducibility determined at electrophysiology (EP) study. These changes were associated with an increase in fibrotic and inflammatory signaling. Transgenic mice expressing a cardiac specific dominant negative SGK1 (SGK1 DN) were protected from obesity-related AF as well as the fibrotic and inflammatory consequences of AF. Finally, optical mapping demonstrated a shorter action potential duration and patch clamp revealed effects on INa, with a decreased peak current as well as a depolarizing shift in activation/inactivation properties in atrial myocytes. ConclusionsDiet induced obesity leads to increased cardiac SGK1 signaling as well as an increase in AF inducibility in obese mice. Genetic SGK1 inhibition reduced AF inducibility, and this effect may be mediated by effects on inflammation, fibrosis, and cellular electrophysiology.

physiology↗