[Should we interfere with the interleukin-6 receptor during COVID-19: What do we know?] / Inhibiteurs du récepteur de l'IL-6 dans le traitement de la COVID-19 : que savons-nous ?

COVID-19 is a viral infection with predominant respiratory tropism. In its most severe forms, the initial viral aggression leads to acute respiratory failure due to damage secondary to an exacerbated inflammatory response provoked by the activation of innate, followed by adaptive immunity. The inflammatory response may entail respiratory distress syndrome, if not multivisceral failure and death. IL-6 receptor inhibitors (Tocilizumab and Sarilumab) have been proposed as treatments. Numerous studies have provided new information, which remains heterogeneous and difficult to interpret. This review is aimed at clarifying the potential role of IL-6 receptor inhibitors in severe forms of COVID-19.

Dietary obesity in mice is associated with lipid deposition and metabolic shifts in the lungs sharing features with the liver.

Obesity is associated with both chronic and acute respiratory illnesses, such as asthma, chronic obstructive pulmonary disease (COPD) or increased susceptibility to infectious diseases. Anatomical but also systemic and local metabolic alterations are proposed contributors to the pathophysiology of lung diseases in the context of obesity. To bring perspective to this discussion, we used NMR to compare the obesity-associated metabolomic profiles of the lung with those of the liver, heart, skeletal muscles, kidneys, brain and serum from male C57Bl/6J mice fed with a high-fat and high-sucrose (HFHSD) diet vs. standard (SD) chow for 14 weeks. Our results showed that the lung was the second most affected organ after the liver, and that the two organs shared reduced one-carbon (1C) metabolism and increased lipid accumulation. Altered 1C metabolism was found in all organs and in the serum, but serine levels were increased only in the lung of HFHSD compared to SD. Lastly, tricarboxylic acid (TCA)-derived metabolites were specifically and oppositely regulated in the serum and kidneys but not in other organs. Collectively, our data highlighted that HFHSD induced specific metabolic changes in all organs, the lung being the second most affected organ, the main alterations affecting metabolite concentrations of the 1C pathway and, to a minor extend, TCA. The absolute metabolite quantification performed in this study reveals some metabolic specificities affecting both the liver and the lung, that may reveal common metabolic determinants to the ongoing pathological process.