Nanocarrier lipid composition modulates the impact of pulmonary surfactant protein B (SP-B) on cellular delivery of siRNA

Two decades since the discovery of the RNA interference (RNAi) pathway, we are now witnessing the approval of the first RNAi-based treatments with small interfering RNA (siRNA) drugs. Nevertheless, the widespread use of siRNA is limited by various extra- and intracellular barriers, requiring its encapsulation in a suitable (nanosized) delivery system. On the intracellular level, the endosomal membrane is a major barrier following endocytosis of siRNA-loaded nanoparticles in target cells and innovative materials to promote cytosolic siRNA delivery are highly sought after. We previously identified the endogenous lung surfactant protein B (SP-B) as siRNA delivery enhancer when reconstituted in (proteo) lipid-coated nanogels. It is known that the surface-active function of SP-B in the lung is influenced by the lipid composition of the lung surfactant. Here, we investigated the role of the lipid component on the siRNA delivery-promoting activity of SP-B proteolipid-coated nanogels in more detail. Our results clearly indicate that SP-B prefers fluid membranes with cholesterol not exceeding physiological levels. In addition, SP-B retains its activity in the presence of different classes of anionic lipids. In contrast, comparable fractions of SP-B did not promote the siRNA delivery potential of DOTAP:DOPE cationic liposomes. Finally, we demonstrate that the beneficial effect of lung surfactant on siRNA delivery is not limited to lung-related cell types, providing broader therapeutic opportunities in other tissues as well

SP-D attenuates LPS-induced formation of human neutrophil extracellular traps (NETs), protecting pulmonary surfactant inactivation by NETs

An exacerbated amount of neutrophil extracellular traps (NETs) can cause dysfunction of systems during inflammation. However, host proteins and factors that suppress NET formation (NETosis) are not clearly identified. Here we show that an innate immune collectin, pulmonary surfactant protein-D (SP-D), attenuates lipopolysaccharide (LPS)-mediated NETosis in human neutrophils by binding to LPS. SP-D deficiency in mice (Sftpd−/−) leads to excess NET formation in the lungs during LPS-mediated inflammation. In the absence of SP-D, NETs inhibit the surface-active properties of lung surfactant, essential to prevent the collapse of alveoli, the air breathing structures of the lungs. SP-D reverses NET-mediated inhibition of surfactant and restores the biophysical properties of surfactant. To the best of our knowledge, this study establishes for the first time that (i) SP-D suppresses LPS-mediated NETosis, (ii) NETs inhibit pulmonary surfactant function in the absence of SP-D, and (iii) SP-D can restore NET-mediated inhibition of the surfactant system

In Vitro functional and structural characterization of a synthetic clinical pulmonary surfactant with enhanced resistance to inhibition

CHF5633 is a novel synthetic clinical pulmonary surfactant preparation composed by two phospholipid species, dipalmitoyl phosphatidylcholine (DPPC) and palmitoyloleoyl phosphatidylglycerol (POPG), and synthetic analogues of the hydrophobic surfactant proteins SP-B and SP-C. In this study, the interfacial properties of CHF5633 in the absence and in the presence of inhibitory serum proteins have been assessed in comparison with a native surfactant purifed from porcine lungs and with poractant alpha, a widely used clinical surfactant preparation. The study of the spreading properties of CHF5633 in a Wilhelmy balance, its ability to adsorb and accumulate at air-liquid interfaces as revealed by a multiwell fuorescence assay, and its dynamic behavior under breathing-like compression-expansion cycling in a Captive Bubble Surfactometer (CBS), all revealed that CHF5633 exhibits a good behavior to reduce and sustain surface tensions to values below 5 mN/m. CHF5633 shows somehow slower initial interfacial adsorption than native surfactant or poractant alpha, but a better resistance to inhibition by serum proteins than the animal-derived clinical surfactant, comparable to that of the full native surfactant complex. Interfacial CHF5633 flms formed in a Langmuir-Blodgett balance coupled with epifuorescence microscopy revealed similar propensity to segregate condensed lipid domains under compression than flms made by native porcine surfactant or poractant alpha. This ability of CHF5633 to segregate condensed lipid phases can be related with a marked thermotropic transition from ordered to disordered membrane phases as exhibited by diferential scanning calorimetry (DSC) of CHF5633 suspensions, occurring at similar temperatures but with higher associated enthalpy than that shown by poractant alpha. The good interfacial behavior of CHF5633 tested under physiologically meaningful conditions in vitro and its higher resistance to inactivation by serum proteins, together with its standardized and well-defned composition, makes it a particularly useful therapeutic preparation to be applied in situations associated with lung infammation and edema, alone or in combined strategies to exploit surfactant-facilitated drug delivery

Metabolic dyshomeostasis induced by SARS-CoV-2 structural proteins reveals immunological insights into viral olfactory interactions

One of the most common symptoms in COVID-19 is a sudden loss of smell. SARS-CoV-2 has been detected in the olfactory bulb (OB) from animal models and sporadically in COVID-19 patients. To decipher the specific role over the SARS-CoV-2 proteome at olfactory level, we characterized the in-depth molecular imbalance induced by the expression of GFP-tagged SARS-CoV-2 structural proteins (M, N, E, S) on mouse OB cells. Transcriptomic and proteomic trajectories uncovered a widespread metabolic remodeling commonly converging in extracellular matrix organization, lipid metabolism and signaling by receptor tyrosine kinases. The molecular singularities and specific interactome expression modules were also characterized for each viral structural factor. The intracellular molecular imbalance induced by each SARS-CoV-2 structural protein was accompanied by differential activation dynamics in survival and immunological routes in parallel with a differentiated secretion profile of chemokines in OB cells. Machine learning through a proteotranscriptomic data integration uncovered TGF-beta signaling as a confluent activation node by the SARS-CoV-2 structural proteome. Taken together, these data provide important avenues for understanding the multifunctional immunomodulatory properties of SARS-CoV-2 M, N, S and E proteins beyond their intrinsic role in virion formation, deciphering mechanistic clues to the olfactory inflammation observed in COVID-19 patients.This work was funded by grants from the Spanish Ministry of Science, Innovation and Universities (Ref. PID2019-110356RB-I00/AEI/10.13039/501100011033) to JF-I. and ES), the Department of Economic and Business Development from Government of Navarra (Ref. 0011-1411-2020-000028 to ES), the Instituto de Salud Carlos III (ISCIII)-FEDER project grants (Ref. FIS PI17/02119, FIS PI20/00010; COV20-00237 to DE), the Department of Health of the Government of Navarre (Ref: BMED 050-2019 to DE) and the European Project Horizon 2020 (ref: ID: 848166; Improved vaccination for older adults-ISOLDA to DE)

Nanocarrier lipid composition modulates the impact of pulmonary surfactant protein B (SP-B) on cellular delivery of siRNA

Two decades since the discovery of the RNA interference (RNAi) pathway, we are now witnessing the approval of the first RNAi-based treatments with small interfering RNA (siRNA) drugs. Nevertheless, the widespread use of siRNA is limited by various extra- and intracellular barriers, requiring its encapsulation in a suitable (nanosized) delivery system. On the intracellular level, the endosomal membrane is a major barrier following endocytosis of siRNA-loaded nanoparticles in target cells and innovative materials to promote cytosolic siRNA delivery are highly sought after. We previously identified the endogenous lung surfactant protein B (SP-B) as siRNA delivery enhancer when reconstituted in (proteo) lipid-coated nanogels. It is known that the surface-active function of SP-B in the lung is influenced by the lipid composition of the lung surfactant. Here, we investigated the role of the lipid component on the siRNA delivery-promoting activity of SP-B proteolipid-coated nanogels in more detail. Our results clearly indicate that SP-B prefers fluid membranes with cholesterol not exceeding physiological levels. In addition, SP-B retains its activity in the presence of different classes of anionic lipids. In contrast, comparable fractions of SP-B did not promote the siRNA delivery potential of DOTAP:DOPE cationic liposomes. Finally, we demonstrate that the beneficial effect of lung surfactant on siRNA delivery is not limited to lung-related cell types, providing broader therapeutic opportunities in other tissues as well

Molecular and biophysical mechanisms behind the enhancement of lung surfactant function during controlled therapeutic hypothermia

Therapeutic hypothermia (TH) enhances pulmonary surfactant performance in vivo by molecular mechanisms still unknown. Here, the interfacial structure and the composition of lung surfactant flms have been analysed in vitro under TH as well as the molecular basis of its improved performance both under physiological and inhibitory conditions. The biophysical activity of a purifed porcine surfactant was tested under slow and breathing-like dynamics by constrained drop surfactometry (CDS) and in the captive bubble surfactometer (CBS) at both 33 and 37 °C. Additionally, the temperaturedependent surfactant activity was also analysed upon inhibition by plasma and subsequent restoration by further surfactant supplementation. Interfacial performance was correlated with lateral structure and lipid composition of flms made of native surfactant. Lipid/protein mixtures designed as models to mimic diferent surfactant contexts were also studied. The capability of surfactant to drastically reduce surface tension was enhanced at 33 °C. Larger DPPC-enriched domains and lower percentages of less active lipids were detected in surfactant flms exposed to TH-like conditions. Surfactant resistance to plasma inhibition was boosted and restoration therapies were more efective at 33 °C. This may explain the improved respiratory outcomes observed in cooled patients with acute respiratory distress syndrome and opens new opportunities in the treatment of acute lung injury

Guía para la elaboración del Trabajo de Fin de Grado en Relaciones Internacionales

Este proyecto de innovación docente ha desarrollado una guía y tres videotutoriales para ayudar al alumnado en la elaboración y exposición del Trabajo Final de Grado en Relaciones Internacionales

Los fondos americanos de la Biblioteca Histórica de la Universidad Complutense de Madrid: Guía de recursos

La Biblioteca Histórica de la Universidad Complutense de Madrid guarda entre sus fondos más de un millar de libros antiguos sobre América o impresos en América, lo que la convierte en uno de los conjuntos más importantes de España sobre tema americano. Esta guía de recursos reúne manuscritos e impresos producidos en el continente americano, así como los que tratan sobre América. Dadas sus especiales características, se ha dedicado un capítulo a Estados Unidos y Canadá

Adquisición, entrenamiento y práctica de competencias y destrezas digitales para estudiar Historia Contemporánea del primer curso de los grados de Antropología Social y Cultural y de la Administración Pública en las Facultades de Políticas y Sociología

Depto. de Historia, Teorías y Geografías PolíticasFac. de Ciencias Políticas y SociologíaFALSEsubmitte