Project description:Supranormal levels of aldosterone are associated with increased cardiovascular risk in humans, and with accelerated atherosclerosis in animal models. Atherosclerosis is a low-grade inflammatory disorder, with monocyte-derived macrophages as major drivers of plaque formation. Monocytes can adopt a long-term pro-inflammatory phenotype after brief stimulation with microbial pathogens or endogenous atherogenic lipoproteins via a process termed trained immunity. Using a primary human in vitro model, we demonstrate that aldosterone induces trained immunity via the mineralocorticoid receptor. We identify fatty acid synthesis as a crucial pathway necessary for the induction of trained immunity in monocyte-derived macrophages and demonstrate that pharmacological inhibition of this pathway blunts aldosterone-induced trained immunity. At the level of gene regulation, aldosterone promotes enrichment of the transcriptionally-permissive H3K4me3 modification at promoters of genes central to the fatty acid synthesis pathway. These data provide mechanistic insight into the contribution of aldosterone to inflammation, atherosclerosis and cardiovascular disease.
Project description:Background: Aldosterone-producing adenomas (APA) are a major cause of primary aldosteronism. While gene mutations in APA trigger aldosterone overproduction via Calcium signaling, their precise regulatory mechanisms remain unclear. Our prior proteomic analysis identified significant upregulation of Tumor protein D52 (TPD52), an oncogene protein implicated in cancer progression, in APA. This study investigates the role of TPD52 in regulating aldosterone synthesis and its molecular mechanism. Method: TPD52 expression was validated in APA specimens. Gain- and loss-of-function studies in NCI-H295R cells were performed to assess its role in aldosterone synthesis. Mechanistic insights were obtained through transcriptomics and immunoprecipitation-mass spectrometry (IP-MS), with key results validated in NCI-H295R and HEK-293T cells. Results: TPD52 was upregulated in APA tissues. Functionally, TPD52 overexpression suppressed aldosterone synthesis in NCI-H295R cells, whereas its knockdown enhanced aldosterone production. Transcriptomics confirmed that TPD52 knockdown promoted CYP11B2 expression and aldosterone synthesis. IP-MS identified calcium/calmodulin-dependent protein kinase kinase 2 (CAMKK2) as a novel TPD52-interacting protein. This interaction suppressed phosphorylation of calmodulin-dependent protein kinase 4 (CAMK4) and CREB. Importantly, CAMKK2 overexpression rescued the TPD52-mediated suppression of CYP11B2 expression and aldosterone synthesis. Conclusion: TPD52 acts as a negative regulator of aldosterone synthesis by inhibiting the CAMKK2–CAMK4–CREB signaling axis.
Project description:scRNAseq of monocytes from in vitro Trained immunity experiments stimulated by β-glucan (BG), uric acid (UA), muramyl dipeptide (MDP), oxidized low-density lipoprotein (oxLDL), or RPMI-Control, and respective samples restimulated with Lipopolysaccharide (LPS).
Project description:We demonstrate that hydroxychloroquine inhibits trained immunity at the functional and epigenetic level and is accompanied by reduced expression of interferon-stimulated genes. Trained immunity comprises a functional adaptation induced by epigenetic reprogramming which facilitates the anti-viral innate immune response.
Project description:Cells harbor two systems for the synthesis of fatty acids, one in the cytoplasm (FASN or fatty acid synthase) and one in the mitochondria (mtFAS). In contrast to FASN, mtFAS is poorly characterized, with the major product(s), metabolic roles, and cellular function(s) essentially unknown. Here we show that hypomorphic mtFAS mutants display a profound loss of electron transport chain (ETC) complexes and exhibit compensatory reductive carboxylation. This effect on ETC complexes is independent of the synthesis of lipoic acid, the best characterized function of mtFAS, as mutants lacking lipoic acid synthesis have an intact ETC. Finally, mtFAS impairment blocks the differentiation of skeletal myoblasts in vitro. These data suggest that ETC activity in mammals is profoundly controlled by mtFAS function, thereby connecting anabolic fatty acid synthesis with the oxidation of carbon fuels.
Project description:Antibiotic resistance and the pandemic of infectious diseases pose major hazards to human health. As a novel anti-infection strategy, trained immunity has a promising future. Recombinant Streptococcus pneumoniae Endopeptidase O (rPepO) is a novel trained immunity inducer that is a highly effective broad-spectrum anti-infective molecule. Here, we demonstrate that rPepO training induces a protective effect by improving the function of several immune cells. rPepO trains macrophages in the periphery to improve their immunological response. In addition, macrophage-derived complement C3 stimulates B lymphocytes to bolster the host's initial line of defense. While trained-macrophage-derived G-CSF changes the host's hematopoiesis and promotes central trained immunity. The "trained" label is found on freshly differentiated mononuclear macrophages, which also possess significantly enhanced anti-infective properties. Consequently, our research reveals that rPepO can induce peripheral and central trained immunity and possesses broad-spectrum and durable antimicrobial characteristics.