Caspase-8 activation by cigarette smoke induces pro-inflammatory cell death of human macrophages exposed to lipopolysaccharide

Cigarette smoking impairs the lung innate immune response making smokers more susceptible to infections and severe symptoms. Dysregulation of cell death is emerging as a key player in chronic inflammatory conditions. We have recently reported that short exposure of human monocyte-derived macrophages (hMDMs) to cigarette smoke extract (CSE) altered the TLR4-dependent response to lipopolysaccharide (LPS). CSE caused inhibition of the MyD88-dependent inflammatory response and activation of TRIF/caspase-8/caspase-1 pathway leading to Gasdermin D (GSDMD) cleavage and increased cell permeability. Herein, we tested the hypothesis that activation of caspase-8 by CSE increased pro-inflammatory cell death of LPS-stimulated macrophages. To this purpose, we measured apoptotic and pyroptotic markers as well as the expression/release of pro-inflammatory mediators in hMDMs exposed to LPS and CSE, alone or in combination, for 6 and 24 h. We show that LPS/CSE-treated hMDMs, but not cells treated with CSE or LPS alone, underwent lytic cell death (LDH release) and displayed apoptotic features (activation of caspase-8 and -3/7, nuclear condensation, and mitochondrial membrane depolarization). Moreover, the negative regulator of caspase-8, coded by CFLAR gene, was downregulated by CSE. Activation of caspase-3 led to Gasdermin E (GSDME) cleavage. Notably, lytic cell death caused the release of the damage-associated molecular patterns (DAMPs) heat shock protein-60 (HSP60) and S100A8/A9. This was accompanied by an impaired inflammatory response resulting in inhibited and delayed release of IL6 and TNF. Of note, increased cleaved caspase-3, higher levels of GSDME and altered expression of cell death-associated genes were found in alveolar macrophages of smoker subjects compared to non-smoking controls. Overall, our findings show that CSE sensitizes human macrophages to cell death by promoting pyroptotic and apoptotic pathways upon encountering LPS. We propose that while the delayed inflammatory response may result in ineffective defenses against infections, the observed cell death associated with DAMP release may contribute to establish chronic inflammation. CS exposure sensitizes human macrophages to pro-inflammatory cell death. Upon exposure to LPS, CS inhibits the TLR4/MyD88 inflammatory response, downregulating the pro-inflammatory genes TNF and IL6 and the anti-apoptotic gene CFLAR, known to counteract caspase-8 activity. CS enhances caspase-8 activation through TLR4/TRIF, with a partial involvement of RIPK1, resulting on the activation of caspase-1/GSDMD axis leading to increased cell permeability and DAMP release through gasdermin pores [19]. At later timepoints caspase-3 becomes strongly activated by caspase-8 triggering apoptotic events which are associated with mitochondrial membrane depolarization, gasdermin E cleavage and secondary necrosis with consequent massive DAMP release

Effectiveness of combination therapy versus monotherapy with a third-generation cephalosporin in bacteraemic pneumococcal pneumonia: A propensity score analysis

Objective: Combining a macrolide or a fluoroquinolone to beta-lactam regimens in the treatment of patients with moderate to severe community-acquired pneumonia is recommended by the international guidelines. However, the information in patients with bacteraemic pneumococcal pneumonia is limited. Methods: A propensity score technique was used to analyze prospectively collected data from all patients with bacteraemic pneumococcal pneumonia admitted from 2000 to 2015 in our institution, who had received empirical treatment with third-generation cephalosporin in monotherapy or plus macrolide or fluoroquinolone. Results: We included 69 patients in the monotherapy group and 314 in the combination group. After adjustment by PS for receiving monotherapy, 30-day mortality (OR 2.89; 95% CI 1.07-7.84) was significantly higher in monotherapy group. A higher 30-day mortality was observed in monotherapy group in both 1:1 and 1:2 matched samples although it was statistically significant only in 1:2 sample (OR: 3.50 (95% CI 1.03-11.96), P = 0.046). Conclusions: Our study suggests that in bacteraemic pneumococcal pneumonia, empirical therapy with a third-generation cephalosporin plus a macrolide or a fluoroquinolone is associated with a lower mortality rate than beta-lactams in monotherapy. These results support the recommendation of combination therapy in patients requiring admission with moderate to severe disease

Effectiveness of combination therapy versus monotherapy with a third-generation cephalosporin in bacteraemic pneumococcal pneumonia: A propensity score analysis

Objective: Combining a macrolide or a fluoroquinolone to beta-lactam regimens in the treatment of patients with moderate to severe community-acquired pneumonia is recommended by the international guidelines. However, the information in patients with bacteraemic pneumococcal pneumonia is limited. Methods: A propensity score technique was used to analyze prospectively collected data from all patients with bacteraemic pneumococcal pneumonia admitted from 2000 to 2015 in our institution, who had received empirical treatment with third-generation cephalosporin in monotherapy or plus macrolide or fluoroquinolone. Results: We included 69 patients in the monotherapy group and 314 in the combination group. After adjustment by PS for receiving monotherapy, 30-day mortality (OR 2.89; 95% CI 1.07-7.84) was significantly higher in monotherapy group. A higher 30-day mortality was observed in monotherapy group in both 1:1 and 1:2 matched samples although it was statistically significant only in 1:2 sample (OR: 3.50 (95% CI 1.03-11.96), P = 0.046). Conclusions: Our study suggests that in bacteraemic pneumococcal pneumonia, empirical therapy with a third-generation cephalosporin plus a macrolide or a fluoroquinolone is associated with a lower mortality rate than beta-lactams in monotherapy. These results support the recommendation of combination therapy in patients requiring admission with moderate to severe disease

The Urban-Rural Continuum. The Bioclimatic Approach to Design, Between Past and Future

L’ambiente costruito rurale, insieme multiscalare di trasformazioni praticate dall’uomo per accogliere le attività collegate all’agricoltura, suggerisce varie riflessioni sull’approccio bioclimatico nel progetto di architettura. Il contributo mette subito in evidenza il tema del continuum urbano-rurale (luogo intermedio e contraddittorio che condensa le trasformazioni che stanno avvenendo nella contemporaneità, offrendo un banco di prova necessario per tutti i campi del sapere e per tutte le discipline tecnologiche) per evidenziare che la contrapposizione tra urbano e rurale non solo è superata nei fatti, ma anche è teoricamente inadeguata a identificare l’ambiente costruito rurale, nonostante sia stata utilizzata sin da antico, sui livelli sia analitico che progettuale. Il superamento di tale contrapposizione viene confermato dal legame tra attività agricole e costruttive, di cui viene proposta una lettura in chiave tecnologica, con riferimento alle sfere del prodotto e del processo, dopo averne ricordato le origini culturali remote e profondamente radicate. Il possibile duplice e contraddittorio carattere dell’ambiente costruito rurale, vernacolare o colto, viene illustrato con riferimento alla specificità degli aspetti bioclimatici riconosciuti negli edifici tradizionali (sostenibilità ante litteram), evidenziando come nel XX secolo si sia cancellato il legame con il fattore sito e con la tradizionale cultura costruttiva, creando le premesse per una ingente e diffusa emergenza qualitativa anche per le costruzioni che ospitano attività produttive primarie. Accennando all’interrogativo se oggi abbia senso una precisa tipologia di edificio produttivo rurale e evidenziando l’importanza delle interrelazioni con gli aspetti socioeconomici del settore produttivo dell’agricoltura, il contributo sottolinea che il costruito rurale nel suo insieme contribuisce all’identità ibrida del paesaggio contemporaneo e conclude dimostrando che proprio l’approccio bioclimatico possa svolgere un ruolo di collante, sia teoretico che operativo, perché contribuisce a creare una comune metodologia, adeguata ad affrontare le sfide contemporanee. superando una certa tendenza alla improvvisazione e eccessivi specialismi e facendo leva su opportune azioni di formazione e divulgazione.The rural built environment, as a multiscale whole of human transformations aimed at accommodating agriculture-related activities, prompts various reflections on the bioclimatic approach in architectural design. This contribution, firstly, highlights the theme of the urban-rural continuum (an intermediate and contradictory place, which epitomizes on-going contemporary transformations) in order to demonstrate that the contrast between urban and rural – although it has been used, since ancient times, on both analytical and design level – has not only been superseded, but is also, theoretically, inadequate for identifying the rural built environment. The link between agricultural and construction activities confirms the overcoming of this contrast; a reading in technological terms is proposed, with reference to the spheres of the product and the process, whilst recollecting its remote and deeply rooted cultural origins. The possible dual and contradictory character (vernacular or scholarly) of the rural built environment is illustrated with reference to the specificity of the bioclimatic aspects recognized in traditional buildings (“ante litteram sustainability”), highlighting how the relationship with the site-factor (microclimatic characteristics and local construction culture) was annulled in the 20th century, also creating the basis for a widespread emergency for the quality of the buildings employed in agricultural activities. Touching upon the question of whether the rural building can be a typology distinct from other production buildings, this paper highlights the importance of the relationships with the socio-economic aspects of the agricultural sector, underlining the fact that the main identity for rural buildings in every age, in addition to the role that they play in the landscape, should be a stronger bond with the environmental elements, showing the centrality of the bioclimatic approach in updating the primordial interactions between agriculture and construction. Furthermore, the distinction between vernacular or scholarly character of the rural buildings prompted a reflection on the contemporary epistemological bases of the bioclimatic approach to general architectural design, which risks being ineffective whether it remains on an empirical level or if it is confined to a hyper-specialized niche. Finally, the bioclimatic approach is indicated as a common analytical and design methodological basis, useful for addressing the contradictory nature of the urban-rural continuum, in the framework of contemporary challenges