LEA13 and LEA30 Are Involved in Tolerance to Water Stress and Stomata Density in Arabidopsis thaliana.

Late embryogenesis abundant (LEA) proteins are a large protein family that mainly function in protecting cells from abiotic stress, but these proteins are also involved in regulating plant growth and development. In this study, we performed a functional analysis of LEA13 and LEA30 from Arabidopsis thaliana. The results showed that the expression of both genes increased when plants were subjected to drought-stressed conditions. The insertional lines lea13 and lea30 were identified for each gene, and both had a T-DNA element in the regulatory region, which caused the genes to be downregulated. Moreover, lea13 and lea30 were more sensitive to drought stress due to their higher transpiration and stomatal spacing. Microarray analysis of the lea13 background showed that genes involved in hormone signaling, stomatal development, and abiotic stress responses were misregulated. Our results showed that LEA proteins are involved in drought tolerance and participate in stomatal density.

Placental exosomes isolated from urine of patients with gestational diabetes exhibit a differential profile expression of microRNAs across gestation.

Placenta­derived exosomes play an important role in cellular communication both in the mother and the fetus. Their concentration and composition are altered in several pregnancy disorders, such as gestational diabetes mellitus (GDM). The isolation and characterization of placental exosomes from serum, plasma and tissues from patients with GDM have been previously described; however, to the best of our knowledge, to date, there is no study available on placental exosomes isolated from urine of patients with GDM. In the present study, placental exosomes were purified from urine the 1st, 2nd and 3rd trimester of gestation. Placental exosomes were characterized by transmission electron microscopy in cryogenic mode and by western blot analysis, confirming the presence of exosomal vesicles. The expression profile of five microRNAs (miR­516­5p, miR­517­3p, miR­518­5p, miR­222­3p and miR­16­5p) was determined by RT­qPCR. In healthy pregnant women, the expression of the miRNAs increased across gestation, apart from miR­516­5p, which was not expressed at the 2nd trimester. All the miRNAs examined were downregulated in patients with GDM at the 3rd trimester of gestation. The downregulated miRNAs affected several metabolic pathways closely associated with the pathophysiology of GDM. This provides further evidence of the regulatory role of miRNAs in the GDM. This also suggests that the of urinary exosomes may be an excellent source of biomarkers and therapeutic targets.

Antibacterial mechanism of gold nanoparticles on Streptococcus pneumoniae.

Streptococcus pneumoniae is a causal agent of otitis media, pneumonia, meningitis and severe cases of septicemia. This human pathogen infects elderly people and children with a high mortality rate of approximately one million deaths per year worldwide. Antibiotic-resistance of S. pneumoniae strains is an increasingly serious health problem; therefore, new therapies capable of combating pneumococcal infections are indispensable. The application of gold nanoparticles has emerged as an option in the control of bacterial infections; however, the mechanism responsible for bacterial cell lysis remains unclear. Specifically, it has been observed that gold nanoparticles are capable of crossing different structures of the S. pneumoniae cells, reaching the cytosol where inclusion bodies of gold nanoparticles are noticed. In this work, a novel process for the separation of such inclusion bodies that allowed the analysis of the biomolecules such as carbohydrates, lipids and proteins associated with the gold nanoparticles was developed. Then, it was possible to separate and identify proteins associated with the gold nanoparticles, which were suggested as possible candidates that facilitate the interaction and entry of gold nanoparticles into S. pneumoniae cells.

Aislamiento y caracterización celular de exosomas de plasma para su uso como biomarcadores de diagnóstico / Isolation and cellular characterization of exosomes from plasma for their use as diagnostic biomarkers / Purificação e caracterização celular de exossomos para seu uso como biomarcadores de diagnóstico

Los exosomas son vesículas membranosas extracelulares esenciales en la comunicación intercelular a larga distancia, viajan en los fluidos corporales y entregan mensajes moleculares dirigidos a la mayoría de las células de todo el organismo. La liberación de mensajes vía exosomas ocurre en forma de ADN, ARN o proteínas; dicha liberación se ha asociado a diferentes condiciones fisiológicas normales y patológicas, como el cáncer. Por lo anterior, el aislamiento eficiente y caracterización celular de exosomas de plasma es clave para su uso como biomarcadores no invasivos de diversas enfermedades. En el presente estudio se purificaron exosomas a partir de muestras clínicas de plasmas de pacientes previamente diagnosticados con retinoblastoma y de individuos sanos como control. Los exosomas recuperados fueron caracterizados a nivel celular por microscopia electrónica de transmisión empleando una técnica de criogenia. Para demostrar la correcta purificación de exosomas se confirmó la presencia de las proteínas transmembranales CD63 y CD81 mediante immunoblot. Adicionalmente de los exosomas purificados, se identificaron ARNs pequeños no codificantes llamados microARNs. En general, se describe la purificación y caracterización celular de exosomas obtenidos de plasma humano para su potencial uso como biomarcadores.

Exosomes are small extracellular vesicles essential in intercellular communication; they act as vehicles of broad scope. They are travelling in body fluids and delivering molecular messages to cells in the organism. Messages released by exosomes like DNA, RNA and proteins are associated with different pathological conditions including cancer. Therefore, the efficient isolation and cellular characterization of exosomes from plasma is essential to use them as biomarkers in many diseases. Here, exosomes were purified from patients diagnosed with pediatric cancer and healthy individuals as control. The exosomes recovered were characterized using cryogenic transmission electron microscopy. Moreover, the presence of CD63 and CD81 transmembrane proteins was confirmed using Western blot. Besides, miRNAs presence was identified from exosomes. This work describes a complete technique to isolate and characterize exosomes from human plasma, recognizing their potential as biomarkers.

Os exossomos são vesículas membranosas extracelulares essenciais na comunicação intercelular de longa distância; eles viajam em fluidos corporais e entregam mensagens moleculares dirigidas à maioria das células de todo o organismo. A liberação de mensagens através dos exossomos ocorre em forma de DNA, RNA ou proteínas; essa liberação foi associada a diferentes condições fisiológicas normais e patológicas, tais como o câncer. Por tudo isso, o eficiente isolamento e caracterização celular de exossomos de plasma é chave para sua utilização como biomarcadores não invasivos de várias doenças. No presente estudo, exossomos foram purificados a partir de amostras clínicas de plasmas de pacientes que tinham sido diagnosticados previamente com retinoblastoma e de indivíduos saudáveis como controle. Os exossomos recuperados foram caracterizados a nível celular por microscopia eletrônica de transmissão usando uma técnica de criogenia. Para demonstrar a correta purificação dos exossomos, foi confirmada a presença de proteínas transmembranares CD63 e CD81 usando inmunoblot. Além dos exossomos purificados foram identificados ARNs não codificantes pequenos chamados microARNs. Em geral os métodos de purificação e caracterização celular de exossomos obtidos de plasma humano são descritos por seu potencial utilização como biomarcadores.