Chicken antimicrobial peptides: Genome-wide identification and functional and structural analysis

Scope and Method of Study: The purpose of the study is to identify novel antimicrobial peptides in chickens and characterize the functions and structures of a few selected peptides for their therapeutic potential. A genome-wide computational screen of the entire chicken genome has been used to identify novel chicken defensins and cathelicidins. Putatively mature cathelicidins, fowlicidin-1 and -2, were synthesized and evaluated for their antibacterial, cytolytic, and LPS-binding activities. The tertiary structure of fowlicidin-1 was determined by CD and NMR. Based on the tertiary structure of fowlicidin-1, a series of truncation and substitution analogs were synthesized and tested separately for their antibacterial, cytolytic, and LPS-binding activities.A gene cluster containing thirteen different beta-defensin genes and a cluster containing three cathelicidin genes have been identified. The beta-defensin gene cluster is found to localize on the chromosome 3q3.5-q3.7 as well as a cluster on chromosome 2p containing three cathelicidin genes. Fowlicidin-1 and -2 were found to display potent and salt-independent activities against a wide range of bacteria, including resistant strains. Furthermore, both fowlicidins are capable of binding lipopolysaccharide (LPS) and neutralize its inflammatory effects. Fowlicidin-1 was revealed to be largely an alpha- helical peptide with a slight kink close to the center. A short peptide variant, namely fowlicidin-1(8-26), stands out with the highest therapeutic potential among all peptide analogs, and represents a safer and more attractive therapeutic candidate than the parent peptide

Low-dose chemotherapy of hepatocellular carcinoma through triggered-release from bilayer-decorated magnetoliposomes

Low-dose (LD) chemotherapy is a promising treatment strategy that may be improved by controlled delivery. Polyethylene glycol-stabilized bilayer-decorated magnetoliposomes (dMLs) have been designed as a stimuli-responsive LD chemotherapy drug delivery system and tested in vitro using Huh-7 hepatocellular carcinoma cell line. The dMLs contained hydrophobic superparamagnetic iron oxide nanoparticles within the lipid bilayer and doxorubicin hydrochloride (DOX, 2 μM) within the aqueous core. Structural analysis by cryogenic transmission electron microscopy and dynamic light scattering showed that the assemblies were approximately 120 nm in diameter. Furthermore, the samples consisted of a mixture of dMLs and bare liposomes (no nanoparticles), which provided dual burst and spontaneous DOX release profiles, respectively. Cell viability results show that the cytotoxicity of DOX-loaded dMLs was similar to that of bare dMLs (∼10%), which indicates that spontaneous DOX leakage had little cytotoxic effect. However, when subjected to a physiologically acceptable radiofrequency (RF) electromagnetic field, cell viability was reduced up to 40% after 8 h and significant cell death (\u3e90%) was observed after 24 h. The therapeutic mechanism was intracellular RF-triggered DOX release from the dMLs and not intracellular hyperthermia due to nanoparticle heating via magnetic losses. [Refer to PDF for graphical abstract

A genome-wide screen identifies a single β-defensin gene cluster in the chicken: implications for the origin and evolution of mammalian defensins

BACKGROUND: Defensins comprise a large family of cationic antimicrobial peptides that are characterized by the presence of a conserved cysteine-rich defensin motif. Based on the spacing pattern of cysteines, these defensins are broadly divided into five groups, namely plant, invertebrate, α-, β-, and θ-defensins, with the last three groups being mostly found in mammalian species. However, the evolutionary relationships among these five groups of defensins remain controversial. RESULTS: Following a comprehensive screen, here we report that the chicken genome encodes a total of 13 different β-defensins but with no other groups of defensins being discovered. These chicken β-defensin genes, designated as Gallinacin 1–13, are clustered densely within a 86-Kb distance on the chromosome 3q3.5-q3.7. The deduced peptides vary from 63 to 104 amino acid residues in length sharing the characteristic defensin motif. Based on the tissue expression pattern, 13 β-defensin genes can be divided into two subgroups with Gallinacin 1–7 being predominantly expressed in bone marrow and the respiratory tract and the remaining genes being restricted to liver and the urogenital tract. Comparative analysis of the defensin clusters among chicken, mouse, and human suggested that vertebrate defensins have evolved from a single β-defensin-like gene, which has undergone rapid duplication, diversification, and translocation in various vertebrate lineages during evolution. CONCLUSIONS: We conclude that the chicken genome encodes only β-defensin sequences and that all mammalian defensins are evolved from a common β-defensin-like ancestor. The α-defensins arose from β-defensins by gene duplication, which may have occurred after the divergence of mammals from other vertebrates, and θ-defensins have arisen from α-defensins specific to the primate lineage. Further analysis of these defensins in different vertebrate lineages will shed light on the mechanisms of host defense and evolution of innate immunity

Toxicity of microplastics and nanoplastics: invisible killers of female fertility and offspring health

Microplastics (MPs) and nanoplastics (NPs) are emergent pollutants, which have sparked widespread concern. They can infiltrate the body via ingestion, inhalation, and cutaneous contact. As such, there is a general worry that MPs/NPs may have an impact on human health in addition to the environmental issues they engender. The threat of MPs/NPs to the liver, gastrointestinal system, and inflammatory levels have been thoroughly documented in the previous research. With the detection of MPs/NPs in fetal compartment and the prevalence of infertility, an increasing number of studies have put an emphasis on their reproductive toxicity in female. Moreover, MPs/NPs have the potential to interact with other contaminants, thus enhancing or diminishing the combined toxicity. This review summarizes the deleterious effects of MPs/NPs and co-exposure with other pollutants on female throughout the reproduction period of various species, spanning from reproductive failure to cross-generational developmental disorders in progenies. Although these impacts may not be directly extrapolated to humans, they do provide a framework for evaluating the potential mechanisms underlying the reproductive toxicity of MPs/NPs

Hybrid Relative Attributes Based on Sparse Coding for Zero-Shot Image Classification

As a specific case of image recognition, zero-shot image classification is difficult to solve since its training set cannot cover all the categories of the testing set. From the view point of human vision recognition, the objects can be recognized through the visible and nameable description to the properties. To be the semantic description of the object property, attributes can be taken as a bridge between the seen and unseen categories, which are capable of using into zero-shot image classification. There are mainly binary attributes and relative attributes for zero-shot classification, where the relative attributes have the ability to catch more general sematic relationship than the binary ones. But relative attributes do not always work in zero-shot classification for those categories having similar relative strength attributes. Aiming at solving the defect of the relative attributes in describing the similar categories, we propose to construct the Hybrid Relative Attributes based on Sparse Coding (SC-HRA). First, sparse coding is implemented on low-level features to get nonsemantic relative attributes, which are the necessary complement to the existing relative attributes. After that, they are integrated with the relative attributes to form the hybrid relative attributes (HRA). HRA ranking functions are then learned by the relative attribute learning. Finally, the class label is obtained according to the predicted ranking results of HRA and the ranking relations of HRA among the categories. To verify the effectiveness of SC-HRA, the extensive experiments are conducted on the datasets of faces and natural scenes. The results show that SC-HRA acquires the higher classification accuracy and AUC value

Discriminative Fusion Correlation Learning for Visible and Infrared Tracking

Discriminative correlation filter- (DCF-) based trackers are computationally efficient and achieve excellent tracking in challenging applications. However, most of them suffer low accuracy and robustness due to the lack of diversity information extracted from a single type of spectral image (visible spectrum). Fusion of visible and infrared imaging sensors, one of the typical multisensor cooperation, provides complementarily useful features and consistently helps recognize the target from the background efficiently in visual tracking. Therefore, this paper proposes a discriminative fusion correlation learning model to improve DCF-based tracking performance by efficiently combining multiple features from visible and infrared images. Fusion learning filters are extracted via late fusion with early estimation, in which the performances of the filters are weighted to improve the flexibility of fusion. Moreover, the proposed discriminative filter selection model considers the surrounding background information in order to increase the discriminability of the template filters so as to improve model learning. Extensive experiments showed that the proposed method achieves superior performances in challenging visible and infrared tracking tasks

Metallogenesis of the Xinjiang Orogens, NW China - New discoveries and ore genesis

The Xinjiang Uygur Autonomous Region in NW China occupies around 1/6 of the total China land size, and contains components of both the Central Asian Orogenic Belt (CADS) and Paleo-Tethyan Orogenic Belt (PTOB). The Paleozoic CAOB is situated in the northern and central parts of Xinjiang, whilst the Paleozoic-Mesozoic PTOB is mainly located in the southern part of Xinjiang. These orogenic belts were formed by the multiphase Paleozoic-Mesozoic terrane accretions and collisions enacted by the Paleo-Asian Ocean and Paleo-Tethys closure, a process that has also generated many well-endowed tectono-metallogenic belts. From north to south, these belts include the Chinese Altay, the Junggar, the Chinese Tianshan and the Kunlun, Alytn and Qimantage mountains. Since the late 1990s, especially in the past 10 years, many Au, Cu, Fe and Pb-Zn deposits have been discovered. These ore deposits commonly show clear but complex relationships with the orogenic processes. Detailed studies of these mineral systems and their associated magmatic-metamorphic events and structural deformation would significantly improve our understanding of the metallogenic evolution of the CAOB and PTOB in Xinjiang. The 33 papers presented in this special issue, which represents the first collective work of Xinjiang mineral resources in international journals, are aimed to convey the latest research findings on key Au, Cu, Fe-(Cu), Pb-Zn and other metal deposits in Xinjiang. It is our wish that this special issue could enhance our knowledge on the nature and evolution of the metallogenesis in the Xinjiang orogens, and reinforce the foundation for future mineral research and exploration