Biology subjects

Peces-Barba, G.

Publications and source records attributed to Peces-Barba, G..

2 recordsLinked to original sources

bioRxiv2025

Intermittent Hypoxia Drives Early Metabolic Dysfunction in Brown Adipose Tissue

BackgroundObstructive sleep apnea (OSA) is associated with metabolic dysfunction, yet the early impact of intermittent hypoxia (IH)--a defining feature of OSA--on brown adipose tissue (BAT) remains unclear. MethodsWe investigated the direct and early effects of IH on BAT using both in vitro and in vivo approaches. Differentiated mouse brown adipocytes were exposed to IH for 48 hours and analyzed for {beta}3-adrenergic signaling, lipolysis, and thermogenic activation. Complementary in vivo studies assessed transcriptomic, morphological, and functional changes in BAT, white adipose tissue (WAT), and liver after 1 or 4 weeks of IH exposure in mice. ResultsIH blunted {beta}3-adrenergic signaling in cultured brown adipocytes, leading to reduced phosphorylation of key signaling proteins, impaired lipolytic response, and decreased expression of UCP1. In vivo, BAT exhibited early and sustained transcriptomic rewiring characterized by downregulation of pathways related to fatty acid metabolism, oxidative phosphorylation, and peroxisomal function. These molecular changes were accompanied by abnormal lipid droplet enlargement and a reduced lipolytic response to adrenergic stimulation. In contrast, WAT showed transient gene expression changes, and the liver displayed a delayed and robust transcriptomic response evident only after four weeks of IH exposure. Despite these metabolic alterations, thermogenic responses to cold challenge remained intact in IH-treated mice. ConclusionsBAT is uniquely and rapidly affected by intermittent hypoxia, undergoing functional, molecular, and morphological changes within one week of exposure. These alterations precede systemic inflammation and metabolic dysfunction, positioning BAT dysfunction as an early event in the pathogenesis of OSA-associated metabolic disease.

pathology↗

bioRxiv2024

Cigarette smoke impairs pulmonary vascular function through nAChR activation

Tobacco smoke is the main risk factor for the development of chronic obstructive pulmonary disease (COPD), a major health concern worldwide. Despite current therapies alleviate symptoms; there remain some limitations in the efficacy of treatments to curb COPD and its cardiovascular morbidities, particularly pulmonary hypertension. Our previous studies demonstrate that cigarette smoke (CS) has direct effects on pulmonary vascular tone homeostasis and contribute to pulmonary arterial dysfunction. This is in part due to altered activity of the voltage-dependent K+ channel, and to an exacerbated oxidative stress promoting a switch in the sGCs redox state. However, further characterization of the molecular basis of CS-mediated PA dysfunction is needed for more effective targeted treatment and prevention. Our current studies explored these molecular pathways and specifically addressed their contribution to the cellular contractile apparatus within pulmonary arteries. Our results proved deleterious effects on the contractile machinery of pulmonary artery smooth muscle cells. Increased oxidative stress and calcium dysregulation resulting from the activation of acetylcholine receptors (nAChR) in the pulmonary artery led to the manifestation of these effects. This groundbreaking discovery unveiled, for the first time, the expression of these receptors in human pulmonary arteries. Furthermore, we proved that inhibitors directed at these receptors demonstrate efficacy in alleviating various harmful effects of smoking and safeguarding pulmonary artery function from damage. These discoveries hold significant clinical implications, as they suggest that treatment with nAChR-targeted inhibitors could constitute a viable therapeutic option for COPD-related pulmonary hypertension in patients who do not respond to conventional medication.

cell biology↗