Juliane F.C. Viana

Bio: Juliane F.C. Viana is an academic researcher from Universidade Católica de Brasília. The author has contributed to research in topics: Cyclotide & Cyclotides. The author has an hindex of 7, co-authored 8 publications receiving 276 citations. Previous affiliations of Juliane F.C. Viana include University of Brasília & Empresa Brasileira de Pesquisa Agropecuária.

Effects of acute aerobic exercise on rats serum extracellular vesicles diameter, concentration and small RNAs content

Abstract: 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.

Characterization of a Bioactive Acyclotide from Palicourea rigida

Abstract: 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

Abstract: 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.

Methods Molecular Biology

Abstract: For over 35 years, biological scientists have come to rely on the research protocols and methodologies in the critically acclaimed Methods in Molecular Biology series. The series was the first to introduce the step-by-step protocols approach that has become the standard in all biomedical protocol publishing. Each protocol is provided in readilyreproducible step-bystep fashion, opening with an introductory overview, a list of the materials and reagents needed to complete the experiment, and followed by a detailed procedure that is supported with a helpful notes section offering tips and tricks of the trade as well as troubleshooting advice. These hallmark features were introduced by series editor Dr. John Walker and constitute the key ingredient in each and every volume of the Methods in Molecular Biology series. Tested and trusted, comprehensive and reliable, all protocols from the series are indexed in PubMed.

Antimicrobial peptides: Promising alternatives in the post feeding antibiotic era.

Abstract: Antimicrobial peptides (AMPs), critical components of the innate immune system, are widely distributed throughout the animal and plant kingdoms. They can protect against a broad array of infection-causing agents, such as bacteria, fungi, parasites, viruses, and tumor cells, and also exhibit immunomodulatory activity. AMPs exert antimicrobial activities primarily through mechanisms involving membrane disruption, so they have a lower likelihood of inducing drug resistance. Extensive studies on the structure-activity relationship have revealed that net charge, hydrophobicity, and amphipathicity are the most important physicochemical and structural determinants endowing AMPs with antimicrobial potency and cell selectivity. This review summarizes the recent advances in AMPs development with respect to characteristics, structure-activity relationships, functions, antimicrobial mechanisms, expression regulation, and applications in food, medicine, and animals.

The Plant Peptidome: An Expanding Repertoire of Structural Features and Biological Functions

Abstract: Peptides fulfill a plethora of functions in plant growth, development, and stress responses. They act as key components of cell-to-cell communication, interfere with signaling and response pathways, or display antimicrobial activity. Strikingly, both the diversity and amount of plant peptides have been largely underestimated. Most characterized plant peptides to date acting as small signaling peptides or antimicrobial peptides are derived from nonfunctional precursor proteins. However, evidence is emerging on peptides derived from a functional protein, directly translated from small open reading frames (without the involvement of a precursor) or even encoded by primary transcripts of microRNAs. These novel types of peptides further add to the complexity of the plant peptidome, even though their number is still limited and functional characterization as well as translational evidence are often controversial. Here, we provide a comprehensive overview of the reported types of plant peptides, including their described functional and structural properties. We propose a novel, unifying peptide classification system to emphasize the enormous diversity in peptide synthesis and consequent complexity of the still expanding knowledge on the plant peptidome.

Trends in microbiology.

Abstract: Recent years have witnessed dramatic progress in microbiology just as in any branch of science. It is no longer enough for the microbiologist to be versed in his own field and to keep abreast with the latest developments in his specialty all over the world and to help advance his or her science, he or she must closely collaborate with specialists in other areas such as biology, chemistry and physics. Other qualities critically important for anybody seeking to carry out research include an ability to predict, to formulate working hypotheses to be later confirmed or refuted, and to be able to foresee future trends in his or her area of interest. As part of the preparation of the Prague Congress of IUMS: Bacteriology and Mycology in 1994 (scheduled for 3-8 July of that year), we invited prominent international microbiologists to join the International Scientific Council forthe 1994 Congress. Most of them accepted the invitation and have taken an active part in preparations for the event. In 1990, we asked the Council's members to let us have their views on future developments in their particular specialties. While some of the would-be contributors were unable to submit their papers because of their rather tight schedules, this book includes 38 contributions from a number of the world's international centres of microbiology even though we do not claim to provide an all-round and in-depth look at outstanding issues of microbiology. Hopefully the presented articles will provide a stimulus for other microbiologists, especially for young scientists just starting their careers. The Czechoslovak Society for Microbiology regards it as a great privilege to have been chosen to organise the IUMS Congress in Prague in I994. Due credit for the success of all, often difficult, discussions regarding all the aspects of the Prague Congress goes to Dr Milog R~zc, the Society's Scientific Secretary, whose sudden demise in 1989 did not allow him to see his dream come true. The presented proceedings should become the first issue of a future series entitled Trends in Microbiology, and we are currently preparing the first volume to be published on the occasion of the Prague IUMS Congress. The idea behind this project is to make such proceedings part of the materials issued for each congress and provide them, together with the Book of Abstracts, to all those attending.

Antifungal Plant Defensins: Mechanisms of Action and Production

Abstract: Plant defensins are small, cysteine-rich peptides that possess biological activity towards a broad range of organisms. Their activity is primarily directed against fungi, but bactericidal and insecticidal actions have also been reported. The mode of action of various antifungal plant defensins has been studied extensively during the last decades and several of their fungal targets have been identified to date. This review summarizes the mechanism of action of well-characterized antifungal plant defensins, including RsAFP2, MsDef1, MtDef4, NaD1 and Psd1, and points out the variety by which antifungal plant defensins affect microbial cell viability. Furthermore, this review summarizes production routes for plant defensins, either via heterologous expression or chemical synthesis. As plant defensins are generally considered non-toxic for plant and mammalian cells, they are regarded as attractive candidates for further development into novel antimicrobial agents.