Lung Extracellular Matrix Hydrogels-Derived Vesicles Contribute to Epithelial Lung Repair

The use of physiomimetic decellularized extracellular matrix-derived hydrogels is attracting interest since they can modulate the therapeutic capacity of numerous cell types, including mesenchymal stromal cells (MSCs). Remarkably, extracellular vesicles (EVs) derived from MSCs display similar functions as their parental cells, mitigating tissue damage in lung diseases. However, recent data have shown that ECM-derived hydrogels could release other resident vesicles similar to EVs. Here, we aim to better understand the contribution of EVs and ECM-vesicles released from MSCs and/or lung-derived hydrogel (L-HG) in lung repair by using an in vitro lung injury model. L-HG derived-vesicles and MSCs EVs cultured either in L-HG or conventional plates were isolated and characterized. The therapeutic capacity of vesicles obtained from each experimental condition was tested by using an alveolar epithelial wound-healing assay. The number of ECM-vesicles released from acellular L-HG was 10-fold greater than EVs from conventional MSCs cell culture revealing that L-HG is an important source of bioactive vesicles. MSCs-derived EVs and L-HG vesicles have similar therapeutic capacity in lung repair. However, when wound closure rate was normalized by total proteins, the MSCs-derived EVs shows higher therapeutic potential to those released by L-HG. The EVs released from L-HG must be considered when HG is used as substrate for cell culture and EVs isolation

A Fast and Efficient Decellularization Method for Tissue Slices

The study and use of decellularized extracellular matrix (dECM) in tissue engineering, regenerative medicine, and pathophysiology have become more prevalent in recent years. To obtain dECM, numerous decellularization procedures have been developed for the entire organ or tissue blocks, employing either perfusion of decellularizing agents through the tissue's vessels or submersion of large sections in decellularizing solutions. However, none of these protocols are suitable for thin tissue slices (less than 100 μm) or allow side-by-side analysis of native and dECM consecutive tissue slices. Here, we present a detailed protocol to decellularize tissue sections while maintaining the sample attached to a glass slide. This protocol consists of consecutive washes and incubations of simple decellularizing agents: ultrapure water, sodium deoxycholate (SD) 2%, and deoxyribonuclease I solution 0.3 mg/mL (DNase I). This novel method has been optimized for a faster decellularization time (2-3 h) and a better correlation between dECM properties and native tissue-specific biomarkers, and has been tested in different types of tissues and species, obtaining similar results. Furthermore, this method can be used for scarce and valuable samples such as clinical biopsies

Plant feeding by Nesidiocoris tenuis: Quantifying its behavioral and mechanical components

Zoophytophagous predators play an important, though sometimes controversial, role in pest management programs in different crops. In tomato crops, damage caused by phytophagy of the mirid Nesidiocoris tenuis has mainly been reported at high predator population levels or when prey is scarce. Previous research has focused on predator/prey ratios, stylet morphology and saliva composition to explain plant damage by N. tenuis. In this study, we investigated the behavioral and mechanical components of the damage. For this, we compared the feeding behaviors of males, females and fifth-instar nymphs of N. tenuis. Additionally, we investigated the type of stylet activities performed by each stage while probing in plant tissue, using the electrical penetration graph technique (EPG). Furthermore, stylectomy was performed and plant histology studied with the aim to correlate the feeding activities observed in the EPG recordings with stylet tip positions in specific tissues of the leaf petioles. Behavioral observations during a 30-min period showed that nymphs probed more frequently (38.6 ± 1.5 probes) than males and females (25.3 ± 1.1 and 24.3 ± 1.1 probes, respectively). Similarly, nymphs spent a higher proportion of time (656.0 ± 67.6 s) feeding on tomato apical sections compared to males and females (403.0 ± 48.8 s and 356.0 ± 43.7 s, respectively). The EPG recordings during 5 h indicated that cell-rupturing was the main stylet activity for all insect stages, and that fifth-instar nymphs spent a higher proportion of time on cell-rupturing events compared to adults. The histological studies revealed a trend of N. tenuis for the tissues within the vascular semi-ring. The stylet tips were found both in the vascular bundles and in the parenchyma of the interfascicular region. The findings of this study confirm an important role of fifth-instar nymphs feeding behavior in the damage potential of N. tenuis. Moreover, the increased time spent on cell rupturing behaviour suggests that stylet laceration and enzymatic maceration of the saliva occurring during this event might greatly contribute to the inflicted damage. A comprehensive understanding of the interactions of N. tenuis with the plant, at both the behavioral and mechanical levels, might shed light on new approaches to minimize its damage potential to tomato while maintaining its benefits as biocontrol agent

Low-cost, open-source device for simultaneously subjecting rodents to different circadian cycles of light, food, and temperature

Exposure of experimental rodents to controlled cycles of light, food, and temperature is important when investigating alterations in circadian cycles that profoundly influence health and disease. However, applying such stimuli simultaneously is difficult in practice. We aimed to design, build, test, and open-source describe a simple device that subjects a conventional mouse cage to independent cycles of physiologically relevant environmental variables. The device is based on a box enclosing the rodent cage to modify the light, feeding, and temperature environments. The device provides temperature-controlled air conditioning (heating or cooling) by a Peltier module and includes programmable feeding and illumination. All functions are set by a user-friendly front panel for independent cycle programming. Bench testing with a model simulating the CO2 production of mice in the cage showed: a) suitable air renewal (by measuring actual ambient CO2), b) controlled realistic illumination at the mouse enclosure (measured by a photometer), c) stable temperature control, and d) correct cycling of light, feeding, and temperature. The cost of all the supplies (retail purchased by e-commerce) was <300 US$. Detailed technical information is open-source provided, allowing for any user to reliably reproduce or modify the device. This approach can considerably facilitate circadian research since using one of the described low-cost devices for any mouse group with a given light-food-temperature paradigm allows for all the experiments to be performed simultaneously, thereby requiring no changes in the light/temperature of a general-use laboratory

Development of a physiomimetic model of acute respiratory distress syndrome by using ECM hydrogels and organ-on-a-chip devices

Acute Respiratory Distress Syndrome is one of the more common fatal complications in COVID-19, characterized by a highly aberrant inflammatory response. Pre-clinical models to study the effect of cell therapy and anti-inflammatory treatments have not comprehensively reproduced the disease due to its high complexity. This work presents a novel physiomimetic in vitro model for Acute Respiratory Distress Syndrome using lung extracellular matrix-derived hydrogels and organ-on-a-chip devices. Monolayres of primary alveolar epithelial cells were cultured on top of decellullarized lung hydrogels containing primary lung mesenchymal stromal cells. Then, cyclic stretch was applied to mimic breathing, and an inflammatory response was induced by using a bacteriotoxin hit. Having simulated the inflamed breathing lung environment, we assessed the effect of an anti-inflammatory drug (i.e., dexamethasone) by studying the secretion of the most relevant inflammatory cytokines. To better identify key players in our model, the impact of the individual factors (cyclic stretch, decellularized lung hydrogel scaffold, and the presence of mesenchymal stromal cells) was studied separately. Results showed that developed model presented a more reduced inflammatory response than traditional models, which is in line with what is expected from the response commonly observed in patients. Further, from the individual analysis of the different stimuli, it was observed that the use of extracellular matrix hydrogels obtained from decellularized lungs had the most significant impact on the change of the inflammatory response. The developed model then opens the door for further in vitro studies with a better-adjusted response to the inflammatory hit and more robust results in the test of different drugs or cell therapy

Lung Extracellular Matrix Hydrogels Enhance Preservation of Type II Phenotype in Primary Alveolar Epithelial Cells

One of the main limitations of in vitro studies on lung diseases is the difficulty of maintaining the type II phenotype of alveolar epithelial cells in culture. This fact has previously been related to the translocation of the mechanosensing Yes-associated protein (YAP) to the nuclei and Rho signaling pathway. In this work, we aimed to culture and subculture primary alveolar type II cells on extracellular matrix lung-derived hydrogels to assess their suitability for phenotype maintenance. Cells cultured on lung hydrogels formed monolayers and maintained type II phenotype for a longer time as compared with those conventionally cultured. Interestingly, cells successfully grew when they were subsequently cultured on a dish. Moreover, cells cultured on a plate showed the active form of the YAP protein and the formation of stress fibers and focal adhesions. The results of chemically inhibiting the Rho pathway strongly suggest that this is one of the mechanisms by which the hydrogel promotes type II phenotype maintenance. These results regarding protein expression strongly suggest that the chemical and biophysical properties of the hydrogel have a considerable impact on the transition from ATII to ATI phenotypes. In conclusion, culturing primary alveolar epithelial cells on lung ECM-derived hydrogels may facilitate the prolonged culturing of these cells, and thus help in the research on lung diseases

Potential for the Postharvest Biological Control of Phthorimaea operculella (Lepidoptera, Gelechiidae) by Blattisocius tarsalis (Mesostigmata, Blattisociidae)

Phthorimaea operculella is one of the most important pests causing damage to stored potatoes. In this work, the effect of temperature (at 10, 20 and 30 °C) on the predation of pest eggs by Blattisocius tarsalis was studied in the laboratory. In addition, the effect of three predatory release rates on two pest densities was studied under microcosm conditions. The results showed that B. tarsalis maintains its predatory capacity at low temperatures (10 °C), obtaining an efficiency of 49.66 ± 5.06% compared to the control. In turn, at 20 °C, a maximum efficacy of 78.17 ± 4.77% was achieved, very similar to that presented at 30 °C (75.57 ± 4.34%). Under microcosm conditions and at low pest density (10 eggs/container), the mortality due to the mite was 96.97 ± 3.03%, 81.82 ± 8.84%, and 84.85 ± 8.30%, respectively, for the three predatory release rates (5, 10 or 20 mites/container). At the high infestation level, the pest control ranged from 61.54 ± 9.21% to 92.31 ± 2.74%, depending on the predatory release rate. The results obtained show that B. tarsalis could be a relevant control agent against P. operculella under non-refrigerated potato storage conditions, as well as in the first stages of their storage under refrigerated conditions

Finite Element Analysis of Electrically Excited Quartz Tuning Fork Devices

Quartz Tuning Fork (QTF)-based Scanning Probe Microscopy (SPM) is an important field of research. A suitable model for the QTF is important to obtain quantitative measurements with these devices. Analytical models have the limitation of being based on the double cantilever configuration. In this paper, we present an electromechanical finite element model of the QTF electrically excited with two free prongs. The model goes beyond the state-of-the-art of numerical simulations currently found in the literature for this QTF configuration. We present the first numerical analysis of both the electrical and mechanical behavior of QTF devices. Experimental measurements obtained with 10 units of the same model of QTF validate the finite element model with a good agreement

Col·leccions singulars a les biblioteques de la Universitat Autònoma de Barcelona

Les biblioteques de la Universitat Autònoma de Barcelona són, com la mateixa institució, entitats amb una història curta; però, malgrat que van començar la seva activitat fa menys de cinquanta anys, els seus fons han assolit una importància considerable i superen en quantitat els de moltes universitats centenàries del nostre context. Les col·leccions de fons antics de les biblioteques de la UAB són, per aquesta mateixa raó, limitades, si bé se n'han anat creant algunes d'especialitzades d'importància i valor singulars. Aquest llibre pretén donar-les a conèixer al món universitari, però també al públic en general. Moltes són col·leccions úniques, fruit del treball persistent del personal bibliotecari, del professorat i de la generositat de moltes persones particulars, que han donat o llegat a la nostra universitat els seus arxius, les seves biblioteques personals o les seves col·leccions especialitzades. Aquestes col·leccions comprenen molts àmbits de les ciències i de les humanitats i, molt sovint, es tracta de col·leccions úniques al nostre país. Hi trobareu també un ampli ventall de tipologies documentals en llengües diverses, des dels mapes fins als audiovisuals, des de les revistes i diaris fins als cartells, des dels fons antics fins als més actuals, arxius personals i fons institucionals. Les biblioteques de la Universitat, a més d'inventariar i catalogar aquests fons documentals, també porten a terme una tasca constant de preservació i difusió, que sovint inclou la digitalització dels documents, que després es posen a l'abast del públic general mitjançant el dipòsit digital institucional (ddd.uab.cat)

Estudi comparat del comportament i els d'anys mecànics en tomaquera causats per Nesidiocoris tenuis i Macrolophus pygmaeus

Treball Final en Màster Universitari en Investigació i Biotecnologia Agràries. Codi: SIZ014. Curs acadèmic: 2016/2017The use of the predatory mirids Nesidiocoris tenuis and Macrolophus pygmaeus in tomato is very effective for the biological control of of the whiteflies (Trialeurodes vaporariorum and Bemisia Tabaci) and more recently for the South American pinkworm Tuta absoluta. Whereas the use of M. pygmaus is considered safe in tomatoes, the use of N. tenuis is controversial due to possible damages derived from its phytophagous feeding. In this context, the present work evaluates the behavior of the two species in order to more accurately determine the causes of the differences in feeding behavior . A total of 120 observations of 30 minutes duration each on tomato apical parts were conducted (20 per sex for adults and 20 for nymphs in both species) . Both adults and nimphs were starved 24 h before used. Mirid observations were made on apical part of tomato plants under binocular microscope and the duration of the different behaviors, the locations visited and the number of feeding punctures performed were measured. Results showed a higher phytophagous activity for N. tenuis. Both, the feeding time and the number of feeding punctured achieved were higher for N. tenuis, especially for the nymphal instar. These results may explain the greater capacity to produce damages of N. tenuis respect to M. pygmaeus in tomato crop.Generalizado el uso de los míridos zoofitófagos Nesidiocoris tenuis y Macrolophus pygmaeus en tomatera en el control biológico de moscas blancas (Trialeurodes vaporariorum y Bemisia Tabaci) y más recientemente en la polilla del tomate Tuta absoluta, se ha observado que mientras que el uso de M. pygmaeus resulta seguro el de N. tenuis es controvertido debido a los posibles perjuicios derivados de su alimentación fitófaga. En este contexto, en el presente trabajo se evalúa los comportamientos de ambas especies a fin de discernir con mayor exactitud las causas de las diferencias en los daños causados al cultivo de tomate por su fitófaga. Para hacerlo se realizaron un total de 120 observaciones (20 por sexo para los adultos i 20 para las ninfas en ambas especies) de 30 min. de duración cada una, en régimen de herbívora previo ayuno de 24 h, sobre los ápices de la tomatera con lupa binocular de manera que se midió el tiempo invertido por los míridos en las actividades realizadas i se contabilizaron el número de picadas. Los resultados mostraron una mayor actividad fitófaga para N. tenuis presentando el mismo unos mayores valores tanto en el tiempo invertido en la alimentación, como en el número de picadas, siendo estos valores especialmente más altos en ninfas. Estos resultados pueden explicar la mayor capacidad de producir daños de N. tenuis respecto a M.pygmaeus en el cultivo de tomate.Generalitzat l’ús dels mírids zoofitòfags Nesidiocoris tenuis i Macrolophus pygmaeus en tomaquera en el control biològic de mosques blanques (Trialeurodes vaporariorum i Bemisia Tabaci) i més recentment en l’arna de la tomaca Tuta absoluta, s’ha trobat que mentre que la utilització de M. pygmaeus resulta segura, la de N. tenuis és controvertida degut a possibles perjudicis derivats de la seua alimentació fitòfaga. En aquest context en el present treball s’ avalua el comportament de les dues espècies a fi de discernir amb major exactitud les causes de les diferències en els danys causats al cultiu de tomaca per la seua fitofàgia. Per fer-ho es van realitzar un total de 120 observacions (20 per sexe per als adults i 20 per a les nimfes en ambdós especies) de 30 min. de durada cadascuna, en règim d’herbívora i amb un dejú previ de 24 h, sobre àpexs de tomaquera amb lupa binocular, de manera que es va mesurar el temps invertit pels mírids en les activitats realitzades i es van comptabilitzar el nombre de picades. Els resultats van mostrar una major activitat de N. tenuis, presentant el mateix uns valors molts més elevats tant en el temps dedicat a l’alimentació, com en el nombre de picades realitzades, sent especialment més alts aquests valors en els estats nimfals. Estos resultats poden explicar la major capacitat de N. tenuis respecte a M. pygmaeus per provocar danys al cultiu de tomaca