Effects of Acute Aerobic Exercise on Rats Serum Extracellular Vesicles Diameter, Concentration and Small RNAs Content.

Physical exercise stimulates organs, mainly the skeletal muscle, to release a broad range of molecules, recently dubbed exerkines. Among them, RNAs, such as miRNAs, piRNAs, and tRNAs loaded in extracellular vesicles (EVs) have the potential to play a significant role in the way muscle and other organs communicate to translate exercise into health. Low, moderate and high intensity treadmill protocols were applied to rat groups, aiming to investigate the impact of exercise on serum EVs and their associated small RNA molecules. Transmission electron microscopy, resistive pulse sensing, and western blotting were used to investigate EVs morphology, size distribution, concentration and EVs marker proteins. Small RNA libraries from EVs RNA were sequenced. Exercise did not change EVs size, while increased EVs concentration. Twelve miRNAs were found differentially expressed after exercise: rno-miR-128-3p, 103-3p, 330-5p, 148a-3p, 191a-5p, 10b-5p, 93-5p, 25-3p, 142-5p, 3068-3p, 142-3p, and 410-3p. No piRNA was found differentially expressed, and one tRNA, trna8336, was found down-regulated after exercise. The differentially expressed miRNAs were predicted to target genes involved in the MAPK pathway. A single bout of exercise impacts EVs and their small RNA load, reinforcing the need for a more detailed investigation into EVs and their load as mediators of health-promoting exercise.

The next generation of antimicrobial peptides (AMPs) as molecular therapeutic tools for the treatment of diseases with social and economic impacts.

Anti-infective drugs have had a key role in the contemporary world, contributing to dramatically decrease mortality rates caused by infectious diseases worldwide. Antimicrobial peptides (AMPs) are multifunctional effectors of the innate immune system of mucosal surfaces and present antimicrobial activity against a range of pathogenic viruses, bacteria, and fungi. However, the discovery and development of new antibacterial drugs is a crucial step to overcome the great challenge posed by the emergence of antibiotic resistance. In this review, we outline recent advances in the development of novel AMPs with improved antimicrobial activities that were achieved through characteristic structural design. In addition, we describe recent progress made to overcome some of the major limitations that have hindered peptide biosynthesis.

Characterization of a Bioactive Acyclotide from Palicourea rigida.

The extraction and purification of parigidin-br3, a cyclotide analogue belonging to the "bracelet" subfamily, from Palicourea rigida leaves is discussed. Unlike conventional cyclotides, parigidin-br3 has free N- and C-termini, as identified by MALDI-TOF/TOF analysis and confirmed by gene structure elucidation, and is one of a small number of acyclotides discovered during recent years. Parigidin-br3 showed cytotoxic activity against MCF-7 (breast cancer) and CACO2 (colorectal adenocarcinoma) cells, with IC50 values of ∼2.5 µM and less than 10% hemolytic activity. Overall, parigidin-br3 is a promising new molecule with cytotoxic properties against tumor cell lines and, unlike many synthetic acyclic analogues, demonstrates that cytotoxic activity is not limited to conventional (i.e., cyclic) cyclotides.

Antifungal nanofibers made by controlled release of sea animal derived peptide.

Candida albicans is a common human-pathogenic fungal species with the ability to cause several diseases including surface infections. Despite the clear difficulties of Candida control, antimicrobial peptides (AMPs) have emerged as an alternative strategy for fungal control. In this report, different concentrations of antifungal Cm-p1 (Cencritchis muricatus peptide 1) were electrospun into nanofibers for drug delivery. The nanofibers were characterized by mass spectrometry confirming the presence of the peptide on the scaffold. Atomic force microscopy and scanning electronic microscopy were used to measure the diameters, showing that Cm-p1 affects fiber morphology as well as the diameter and scaffold thickness. The Cm-p1 release behavior from the nanofibers demonstrated peptide release from 30 min to three days, leading to effective yeast control in the first 24 hours. Moreover, the biocompatibility of the fibers were evaluated through a MTS assay as well as ROS production by using a HUVEC model, showing that the fibers do not affect cell viability and only nanofibers containing 10% Cm-p1-PVA improved ROS generation. In addition, the secretion of pro-inflammatory cytokines IL-6 and TNF-α by the HUVECs was also slightly modified by the 10% Cm-p1-PVA nanofibers. In conclusion, the electrospinning technique applied here allowed for the manufacture of biodegradable biomimetic nanofibrous extracellular membranes with the ability to control fungal infection.

The use of versatile plant antimicrobial peptides in agribusiness and human health.

Plant immune responses involve a wide diversity of physiological reactions that are induced by the recognition of pathogens, such as hypersensitive responses, cell wall modifications, and the synthesis of antimicrobial molecules including antimicrobial peptides (AMPs). These proteinaceous molecules have been widely studied, presenting peculiar characteristics such as conserved domains and a conserved disulfide bond pattern. Currently, many AMP classes with diverse modes of action are known, having been isolated from a large number of organisms. Plant AMPs comprise an interesting source of studies nowadays, and among these there are reports of different classes, including defensins, albumins, cyclotides, snakins and several others. These peptides have been widely used in works that pursue human disease control, including nosocomial infections, as well as for agricultural purposes. In this context, this review will focus on the relevance of the structural-function relations of AMPs derived from plants and their proper use in applications for human health and agribusiness.

Heterologous production of peptides in plants: fusion proteins and beyond.

Recombinant DNA technology has allowed the ectopic production of proteins and peptides of different organisms leading to biopharmaceutical production in large cultures of bacterial, yeasts and mammalian cells. Otherwise, the expression of recombinant proteins and peptides in plants is an attractive alternative presenting several advantages over the commonly used expression systems including reduced production costs, easy scale-up and reduced risks of pathogen contamination. Different types of proteins and peptides have been expressed in plants, including antibodies, antigens, and proteins and peptides of medical, veterinary and industrial applications. However, apart from providing a proof of concept, the use of plants as platforms for heterologous protein and peptide production still depends on key steps towards optimization including the enhancement of expression levels, manipulation of post-transcriptional modifications and improvements in purification methods. In this review, strategies to increase heterologous protein and peptide stability and accumulation are discussed, focusing on the expression of peptides through the use of gene fusions.