In chronic respiratory diseases (CRDs), oxidative stress and inflammation are closely linked, driving disease onset, progression, and comorbidities. Oxidative stress activates inflammatory pathways, while chronic inflammation promotes further reactive oxygen species (ROS) production, creating a vicious cycle leading to airway remodeling, reduced lung function, and exacerbations. This review highlights the central roles of inflammation and oxidative stress in chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA). In COPD, chronic hypoxemia associates with emphysema, appearing with disease progression. In OSA, beyond systemic consequences, pulmonary inflammation and oxidative stress contribute to lung injury as well. Although COPD and OSA are distinct conditions, some patients present with “overlap syndrome”, a term used in this review to describe the coexistence of both. This combination poses unique diagnostic and therapeutic challenges. We also examine the role of hypoxia and its transcriptional effects via hypoxia-inducible factors (HIFs) in promoting oxidative stress and inflammation. Finally, we explore how artificial intelligence (AI) offers promising tools to improve diagnosis, monitoring, and management of CRDs and may help elucidate mechanistic links between hypoxia, inflammation, and oxidative stress, contributing to more personalized therapeutic strategies.
Chronic obstructive pulmonary disease (COPD), whose main risk factor is cigarette smoking, is among the most prevalent diseases worldwide. Previous studies have shown that cigarette smoke extract (CSE) can directly affect pulmonary artery function independently of hypoxia resulting from the airway obstruction. In addition, CSE also affects bronchial smooth muscle, leading to airway hyper-responsiveness. However, its specific impact on the contractile machinery of this compartment remains unclear. In this study, using in vitro experiments with human bronchial smooth muscle cells (hBSMCs), we found that CSE exposure disrupted calcium homeostasis, increased ROS and lipid peroxidation, and reduced cell antioxidant defenses. Furthermore, CSE exposure altered the cell contractile apparatus by decreasing key cytoskeletal proteins and impairing actin dynamics, potentially contributing to the dysregulated contractile response of cells. Notably, these effects were significantly attenuated by antioxidant drugs such as mitoTEMPO and N-acetylcysteine, as well as by the inhibition of the endoplasmic reticulum (ER) calcium channels with 2-aminoethoxydiphenyl borate (2-APB). More importantly, mitoTEMPO partially restored the contractile response of bronchus upon CSE challenge. Collectively, our findings give evidence that CSE-mediated increase in ROS and intracellular calcium contribute to cytoskeletal disruption and functional impairment in airway smooth muscle. Moreover, these results also point to potential therapeutical approaches for mitigating the harmful effects of cigarette smoke in the lung.
6 January 2025 in Journal of the Endocrine Society
The hypothalamus integrates peripheral signals and modulates food intake and energy expenditure by regulating the metabolic function of peripheral tissues, including the liver and adipose tissue. In a previous study, we demonstrated that s-resistin, an intracellular resistin isoform highly expressed in the hypothalamus and upregulated during aging, is important in the central control of energy homeostasis, affecting mainly the peripheral response to insulin by still unknown mechanisms. Herein, using an intracerebroventricular injection of a specific lentiviral RNAi against s-resistin, we assessed, in the Wistar rat, the effects of central s-resistin downregulation on the expression and phosphorylation levels of intermediates involved in insulin signaling and the inflammatory response in epididymal white adipose tissue (eWAT) and liver. Additionally, we studied the imbalance of eWAT hypertrophy/hyperplasia remodeling. Our results indicate that central downregulation of s-resistin regulates insulin signaling cascade in a tissue-specific manner, reduces the inflammatory status both in the liver and eWAT, and prevents eWAT hypertrophy. Taken together, our results highlight the pivotal role of central s-resistin in maintaining metabolic homeostasis in AT and the liver. This suggests a direct association between its function and the modulation of the inflammatory response in these tissues.
Chronic obstructive pulmonary disease (COPD), whose main risk factor is cigarette smoking, is among the most prevalent diseases worldwide. Previous studies have shown that cigarette smoke extract (CSE) can directly affect pulmonary artery function independently of hypoxia resulting from the airway obstruction. In addition, CSE also affects bronchial smooth muscle, leading to airway hyper-responsiveness. However, its specific impact on the contractile machinery of this compartment remains unclear. In this study, using in vitro experiments with human bronchial smooth muscle cells (hBSMC) we found that CSE exposure disrupted calcium homeostasis, increased ROS and lipid peroxidation, and reduced cell antioxidant defenses. Furthermore, CSE exposure altered the cell contractile apparatus by decreasing key cytoskeletal proteins and impairing actin dynamics, this potentially contributing to cell dysregulated contractile response. Notably, these effects were significantly attenuated by antioxidant drugs such as mitoTEMPO and N-acetylcysteine, as well as by the inhibition of the RE calcium channels with 2-aminoethoxydiphenyl borate (2-APB). More importantly, mitoTEMPO partially restored the contractile response of bronchus upon CSE challenge. Collectively, our findings give evidence that CSE-mediated increase in ROS and intracellular calcium contribute to cytoskeletal disruption and functional impairment in airway smooth muscle. Moreover, these results also point to potential therapeutical approaches for mitigating the harmful effects of cigarette smoke in the lung.
In chronic respiratory diseases (CRDs), oxidative stress and inflammation exhibit a strong pathophysiological interplay, playing essential roles in the onset and progression of these conditions and their associated comorbidities. Oxidative stress can activate inflammatory pathways, leading to sustained airway inflammation. In turn, chronic inflammation can increase the production of reactive oxygen species (ROS), thereby exacerbating oxidative stress. This vicious cycle contributes to airway remodeling, reduced lung function, and disease progression. This review emphasizes the central roles of inflammation and oxidative stress in two of the most prevalent hypoxemic conditions, chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA), as well as their involvement in the development of major comorbidities. A comprehensive understanding of these processes is crucial to developing therapeutic strategies aimed at reducing oxidative stress and inflammation for the effective management and treatment of CRDs and their comorbidities. It also underscores the crucial role of hypoxia and its transcriptional effects, mediated by hypoxia-inducible factors (HIF), as a primary driver of disease progression through the promotion of oxidative stress and inflammation. Another key element is the rapid advancement of Artificial Intelligence (AI), which presents promising strategies to mitigate the global burden of CRDs. AI holds potential for reducing healthcare costs while improving diagnostic specificity, enabling earlier detection, and optimizing disease monitoring and management. This review explores the current landscape and future prospects of AI in transforming the diagnosis, clinical management, and prognosis of these respira-tory disorders.
Hypoxia-inducible factors (HIFs) are constitutively active in clear cell renal cell carcinoma (ccRCC) cells. Here, we investigated whether these cells could still respond to hypoxia independently of canonical HIF activation. We found that hypoxia provokes a NADH reductive stress that attenuates lactate release when the supply of extracellular pyruvate becomes limited, a response that was restored by the ectopic expression of the cytosolic and mitochondria-targeted NADH oxidase ( Lb NOX). Suppression of the mitochondrial electron transport chain (mtETC) alone is sufficient to attenuate glycolytic flux when extracellular pyruvate is limited, a situation consistent with metabolomic data from human ccRCCs. Furthermore, this response can be mimicked by pharmacological or genetic inhibition of mitochondrial complex IV (CIV) activity and restored by the mitochondrial-targeted alternative oxidase (AOX). Therefore, our data suggest that cells can respond to low oxygen tension through a mitochondrial-dependent elevation of NADH/NAD + , resulting in the suppression of glycolysis when pyruvate availability is compromised.