Aeroterrestrial and Extremophilic Microalgae as Promising Sources for Lipids and Lipid Nanoparticles in Dermal Cosmetics

Microscopic prokaryotic and eukaryotic algae (microalgae), which can be effectively grown in mass cultures, are gaining increasing interest in cosmetics. Up to now, the main attention was on aquatic algae, while species from aeroterrestrial and extreme environments remained underestimated. In these habitats, algae accumulate high amounts of some chemical substances or develop specific compounds, which cause them to thrive in inimical conditions. Among such biologically active molecules is a large family of lipids, which are significant constituents in living organisms and valuable ingredients in cosmetic formulations. Therefore, natural sources of lipids are increasingly in demand in the modern cosmetic industry and its innovative technologies. Among novelties in skin care products is the use of lipid nanoparticles as carriers of dermatologically active ingredients, which enhance their penetration and release in the skin strata. This review is an attempt to comprehensively cover the available literature on the high-value lipids from microalgae, which inhabit aeroterrestrial and extreme habitats (AEM). Data on different compounds of 87 species, subspecies and varieties from 53 genera (represented by more than 141 strains) from five phyla are provided and, despite some gaps in the current knowledge, demonstrate the promising potential of AEM as sources of valuable lipids for novel skin care products.

Structure of the Potential Virulence Factor from Francisella tularensis Shows Unexpected Presence of the SHS2 Motif and Similarity to Other Bacterial Virulence Factors

Pathogenic bacteria attack their host by secreting virulence factors that in various ways interrupt host defenses and damage their cells. Functions of many virulence factors, even from well-studied pathogens, are still unknown. Francisella tularensis is a class A pathogen and a causative agent of tularemia, a disease that is lethal without proper treatment. Here we report the three-dimensional structure and preliminary analysis of the potential virulence factor identified by the transcriptomic analysis of the F. tularensis disease models that is encoded by the FTT_1539 gene. The structure of the FTT_1539 protein contains two sets of three stranded antiparallel beta sheets, with a helix placed between the first and the second beta strand in each sheet. This structural motif, previously seen in virulence factors from other pathogens, was named the SHS2 motif and identified to play a role in protein-protein interactions and small molecule recognition. Sequence and structure analysis identified FTT_1539 as a member of a large family of secreted proteins from a broad range of pathogenic bacteria, such as Helicobacter pylori and Mycobacterium tuberculosis. While the specific function of the proteins from this class is still unknown, their similarity to the H. pylori Tip-α protein that induces TNF-a and other chemokines through NF-kB activation suggests the existence of a common pathogen-host interference mechanism shared by multiple human pathogens.

Weighted Relative Group Entropies and Associated Fisher Metrics

A large family of new α-weighted group entropy functionals is defined and associated Fisher-like metrics are considered. All these notions are well-suited semi-Riemannian tools for the geometrization of entropy-related statistical models, where they may act as sensitive controlling invariants. The main result of the paper establishes a link between such a metric and a canonical one. A sufficient condition is found, in order that the two metrics be conformal (or homothetic). In particular, we recover a recent result, established for α=1 and for non-weighted relative group entropies. Our conformality condition is “universal”, in the sense that it does not depend on the group exponential.

Structural and Functional Characterization of Camelus dromedarius Glutathione Transferase M1-1

Glutathione transferases (GSTs; EC. 2.5.1.18) are a large family of multifunctional enzymes that play crucial roles in the metabolism and inactivation of a broad range of xenobiotic compounds. In the present work, we report the kinetic and structural characterization of the isoenzyme GSTM1-1 from Camelus dromedarius (CdGSTM1-1). The CdGSΤM1-1 was expressed in E. coli BL21 (DE3) and was purified by affinity chromatography. Kinetics analysis showed that the enzyme displays a relative narrow substrate specificity and restricted ability to bind xenobiotic compounds. The crystal structures of CdGSΤM1-1 were determined by X-ray crystallography in complex with the substrate (GSH) or the reaction product (S-p-nitrobenzyl-GSH), providing snapshots of the induced-fit catalytic mechanism. The thermodynamic stability of CdGSTM1-1 was investigated using differential scanning fluorimetry (DSF) in the absence and in presence of GSH and S-p-nitrobenzyl-GSH and revealed that the enzyme’s structure is significantly stabilized by its ligands. The results of the present study advance the understanding of camelid GST detoxification mechanisms and their contribution to abiotic stress adaptation in harsh desert conditions.

Preferences Single-Peaked on a Tree: Multiwinner Elections and Structural Results

A preference profile is single-peaked on a tree if the candidate set can be equipped with a tree structure so that the preferences of each voter are decreasing from their top candidate along all paths in the tree. This notion was introduced by Demange (1982), and subsequently Trick (1989b) described an efficient algorithm for deciding if a given profile is single-peaked on a tree. We study the complexity of multiwinner elections under several variants of the Chamberlin–Courant rule for preferences single-peaked on trees. We show that in this setting the egalitarian version of this rule admits a polynomial-time winner determination algorithm. For the utilitarian version, we prove that winner determination remains NP-hard for the Borda scoring function; indeed, this hardness results extends to a large family of scoring functions. However, a winning committee can be found in polynomial time if either the number of leaves or the number of internal vertices of the underlying tree is bounded by a constant. To benefit from these positive results, we need a procedure that can determine whether a given profile is single-peaked on a tree that has additional desirable properties (such as, e.g., a small number of leaves). To address this challenge, we develop a structural approach that enables us to compactly represent all trees with respect to which a given profile is single-peaked. We show how to use this representation to efficiently find the best tree for a given profile for use with our winner determination algorithms: Given a profile, we can efficiently find a tree with the minimum number of leaves, or a tree with the minimum number of internal vertices among trees on which the profile is single-peaked. We then explore the power and limitations of this framework: we develop polynomial-time algorithms to find trees with the smallest maximum degree, diameter, or pathwidth, but show that it is NP-hard to check whether a given profile is single-peaked on a tree that is isomorphic to a given tree, or on a regular tree.

Characterization of CAP1 and ECA4 adaptors participating in clathrin-mediated endocytosis

Formation of endomembrane vesicles is crucial in all eukaryotic cells and relies on vesicle coats such as clathrin. Clathrin-coated vesicles form at the plasma membrane and the trans-Golgi Network. They contain adaptor proteins, which serve as binding bridges between clathrin, vesicle membranes, and cargoes. A large family of monomeric ANTH/ENTH/VHS adaptors is present in A. thaliana. Here, we characterize two homologous ANTH-type clathrin adaptors, CAP1 and ECA4, in clathrin-mediated endocytosis (CME). CAP1 and ECA4 are recruited to sites at the PM identified as clathrin-coated pits (CCPs), where they occasionally exhibit early bursts of high recruitment. Subcellular binding preferences of N- and C-terminal fluorescent protein fusions of CAP1 identified a functional adaptin-binding motif in the unstructured tails of CAP1 and ECA4. In turn, no function can be ascribed to a double serine phosphorylation site conserved in these proteins. Double knockout mutants do not exhibit deficiencies in general development or CME, but a contribution of CAP1 and ECA4 to these processes is revealed in crosses into sensitized endocytic mutant backgrounds. Overall, our study documents a contribution of CAP1 and ECA4 to CME in A. thaliana and opens questions about functional redundancy among non-homologous vesicle coat components.

Polysaccharide 3D Printing for Drug Delivery Applications

3D printing, or additive manufacturing, has gained considerable interest due to its versatility regarding design as well as in the large choice of materials. It is a powerful tool in the field of personalized pharmaceutical treatment, particularly crucial for pediatric and geriatric patients. Polysaccharides are abundant and inexpensive natural polymers, that are already widely used in the food industry and as excipients in pharmaceutical and cosmetic formulations. Due to their intrinsic properties, such as biocompatibility, biodegradability, non-immunogenicity, etc., polysaccharides are largely investigated as matrices for drug delivery. Although an increasing number of interesting reviews on additive manufacturing and drug delivery are being published, there is a gap concerning the printing of polysaccharides. In this article, we will review recent advances in the 3D printing of polysaccharides focused on drug delivery applications. Among the large family of polysaccharides, the present review will particularly focus on cellulose and cellulose derivatives, chitosan and sodium alginate, printed by fused deposition modeling and extrusion-based printing.

Mobile Genetic Elements Drive Antimicrobial Resistance Gene Spread in Pasteurellaceae Species

Mobile genetic elements (MGEs) and antimicrobial resistance (AMR) drive important ecological relationships in microbial communities and pathogen-host interaction. In this study, we investigated the resistome-associated mobilome in 345 publicly available Pasteurellaceae genomes, a large family of Gram-negative bacteria including major human and animal pathogens. We generated a comprehensive dataset of the mobilome integrated into genomes, including 10,820 insertion sequences, 2,939 prophages, and 43 integrative and conjugative elements. Also, we assessed plasmid sequences of Pasteurellaceae. Our findings greatly expand the diversity of MGEs for the family, including a description of novel elements. We discovered that MGEs are comparable and dispersed across species and that they also co-occur in genomes, contributing to the family’s ecology via gene transfer. In addition, we investigated the impact of these elements in the dissemination and shaping of AMR genes. A total of 55 different AMR genes were mapped to 721 locations in the dataset. MGEs are linked with 77.6% of AMR genes discovered, indicating their important involvement in the acquisition and transmission of such genes. This study provides an uncharted view of the Pasteurellaceae by demonstrating the global distribution of resistance genes linked with MGEs.

Self-similar solutions to fully nonlinear curvature flows by high powers of curvature

In this paper, we investigate closed strictly convex hypersurfaces in ℝ n + 1 {\mathbb{R}^{n+1}} which shrink self-similarly under a large family of fully nonlinear curvature flows by high powers of curvature. When the speed function is given by powers of a homogeneous of degree 1 and inverse concave function of the principal curvatures with power greater than 1, we prove that the only such hypersurfaces are round spheres. We also prove that slices are the only closed strictly convex self-similar solutions to such curvature flows in the hemisphere 𝕊 + n + 1 {\mathbb{S}^{n+1}_{+}} with power greater than or equal to 1.

Differential mosquito attraction to humans is associated with skin-derived carboxylic acid levels

Female Aedes aegypti mosquitoes feed on human blood, which they use to develop their eggs. It has been widely noted that some people are more attractive to mosquitoes than others, but the mechanistic basis of this phenomenon is poorly understood. Here we tested mosquito attraction to skin odor collected from human subjects and identified people who are exceptionally attractive or unattractive to mosquitoes. Notably, these preferences were stable over several years, indicating consistent longitudinal differences in skin odor between subjects. We carried out gas chromatography/quadrupole time of flight-mass spectrometry to analyze the chemical composition of human skin odor in these subjects and discovered that highly attractive people produce significantly increased levels of carboxylic acids. Consistent with the hypothesis that odor concentration is a major driver of differential attraction, mosquitoes could reliably distinguish a highly attractive human from their weakly attractive counterparts unless we substantially diluted the odor of the most attractive subject. Our work suggests that an increased abundance of mosquito attractants on the preferred subject explains differential attraction, rather than the non-preferred skin odor blend being repellent. Mosquitoes detect carboxylic acids with a large family of odor-gated ion channels encoded by the Ionotropic Receptor gene superfamily. Mutant mosquitoes lacking any of the Ionotropic Receptor (IR) co-receptors Ir8a, Ir25a, and Ir76b, were severely impaired in attraction to human scent but retained the ability to differentiate highly and weakly attractive people. The link between elevated carboxylic acids in mosquito-magnet human skin odor and phenotypes of genetic mutations in carboxylic acid receptors suggests that such compounds contribute to differential mosquito attraction. Understanding why some humans are more attractive than others will provide insights into what skin odorants are most important to the mosquito and could inform the development of more effective repellents.