Characterization of antibiofilm compound from marine sponge Stylissa carteri.

The fouling phenomenon grabbed global attention and caused huge economic losses specifically in marine-related industries. Sessile behavior exposed the sponge to the risk of fouling. However, their bodies remained free from foulers, which were attributed to the chemical defense system. The objectives of this study were to determine the antibiofilm activity of the marine sponge, Stylissa carteri, and to characterize the isolated compound involved. The antibiofilm activity of S. carteri methanolic crude extract (MCE) and fractions was tested against biofilm-producing bacteria, Pseudomonas aeruginosa, using two different modes of crystal violet biofilm assays: preventive and detachment. Besides that, the disc-diffusion test was conducted to screen the antibacterial activity against gram-positive and gram-negative bacteria while a cytotoxicity assay was conducted on the HepG2 cell line. Bioassay-guided fractionation was carried out using vacuum liquid chromatography (VLC) and solid phase extraction using a C18 Sep-Pak Cartridge. The crystal compound was isolated and characterized through thin-layer chromatography (TLC), Fourier transform infrared (FTIR) spectroscopy, liquid chromatography-mass spectrometry (LCMS), and nuclear magnetic resonance (NMR) spectroscopy. The S. carteri MCE showed a promising result with a half-maximal inhibitory concentration (IC50) of 20.22 µg/mL in the preventive assay, while no IC50 was determined in the detachment assay since all inhibitions < 50%. The S. carteri MCE exhibited broad-spectrum antibacterial activity and displayed a non-cytotoxic effect. Fraction 4 from MCE of S. carteri (IC50 = 2.40 µg/mL) reduced the biofilm in the preventive assay at all concentrations and exhibited no antibacterial activity indicating the independence of antibiofilm from antibacterial properties. Based on the data obtained, an alkaloid named debromohymenialdisine (DBH) was identified from Fraction 4 of S. carteri MCE. In conclusion, S. carteri was able to reduce the establishment of the biofilm formed by P. aeruginosa and could serve as a prominent source of natural antifouling agents.

Effect of Gracilaria changii extract and its fraction in reverse cholesterol transport by targeting SR-BI gene.

This present study aimed to investigate the effects of Gracilaria changii (Red seaweed) extract and its fraction on scavenger receptor class B type I (SR-BI) gene expressions. In vitro studies of the activity of G. changii extract and its fraction against the therapeutic target for hypocholesterolemia were conducted using high-density lipoprotein (HDL) receptor SR-BI via luciferase assay in HepG2 cells. In the current study, methanol crude extract (MCE) and Fraction-2 of G. changii showed the highest expression levels of the SR-BI gene via luciferase assay and increased SR-BI mRNA expression compared to the negative control. Metabolite profiling of the MCE of G. changii by GC-MS revealed nine major compounds, comprising various fatty acids, particularly hexadecenoic acid. Therefore, the MCE and Fraction-2 of G. changii have the potential to be explored in the treatment of hypercholesterolaemia to prevent or reduce the severity of atherosclerosis development.

Comparative putative metabolites profiling of Tachypleus gigas and Carcinoscorpius rotundicauda hemocytes stimulated with lipopolysaccharide.

Horseshoe crabs are among the most studied invertebrates due to their unique, innate immune system and biological processes. The metabolomics study was conducted on lipopolysaccharide (LPS)-stimulated and non-stimulated hemocytes isolated from the Malaysian Tachypleus gigas and Carcinoscorpius rotundicauda. LC-TOF-MS, multivariate analyses, principal component analysis (PCA), and partial least squares-discriminant analysis (PLS-DA) were included in this study to profile the metabolites. A total of 37 metabolites were identified to be differentially abundant and were selected based on VIP > 1. However, of the 37 putative metabolites, only 23 were found to be significant with ANOVA at p < 0.05. The metabolites were identified using several databases, and the literature review of the metabolites was reported in the manuscript. Thus, this study has provided further insights into the putative metabolites' presence in the hemocytes of horseshoe crabs that are stimulated and non-stimulated with LPS and their abundance in each species. Several putative metabolites showed they have medicinal values from previous studies.

Molecular docking and dynamics simulation studies uncover the host-pathogen protein-protein interactions in Penaeus vannamei and Vibrio parahaemolyticus.

Shrimp aquaculture contributes significantly to global economic growth, and the whiteleg shrimp, Penaeus vannamei, is a leading species in this industry. However, Vibrio parahaemolyticus infection poses a major challenge in ensuring the success of P. vannamei aquaculture. Despite its significance in this industry, the biological knowledge of its pathogenesis remains unclear. Hence, this study was conducted to identify the interaction sites and binding affinity between several immune-related proteins of P. vannamei with V. parahaemolyticus proteins associated with virulence factors. Potential interaction sites and the binding affinity between host and pathogen proteins were identified using molecular docking and dynamics (MD) simulation. The P. vannamei-V. parahaemolyticus protein-protein interaction of Complex 1 (Ferritin-HrpE/YscL family type III secretion apparatus protein), Complex 2 (Protein kinase domain-containing protein-Chemotaxis CheY protein), and Complex 3 (GPCR-Chemotaxis CheY protein) was found to interact with -4319.76, -5271.39, and -4725.57 of the docked score and the formation of intermolecular bonds at several interacting residues. The docked scores of Complex 1, Complex 2, and Complex 3 were validated using MD simulation analysis, which revealed these complexes greatly contribute to the interactions between P. vannamei and V. parahaemolyticus proteins, with binding free energies of -22.50 kJ/mol, -30.20 kJ/mol, and -26.27 kJ/mol, respectively. This finding illustrates the capability of computational approaches to search for molecular binding sites between host and pathogen, which could increase the knowledge of Vibrio spp. infection on shrimps, which then can be used to assist in the development of effective treatment.

Correction: Nordin et al. The State of the Art of Natural Polymer Functionalized Fe3O4 Magnetic Nanoparticle Composites for Drug Delivery Applications: A Review. Gels 2023, 9, 121.

In the original publication [...].

Peptide-Based Vaccine against Breast Cancer: Recent Advances and Prospects.

Breast cancer is considered the second-leading cancer after lung cancer and is the most prevalent cancer among women globally. Currently, cancer immunotherapy via vaccine has gained great attention due to specific and targeted immune cell activity that creates a potent immune response, thus providing long-lasting protection against the disease. Despite peptides being very susceptible to enzymatic degradation and poor immunogenicity, they can be easily customized with selected epitopes to induce a specific immune response and particulate with carriers to improve their delivery and thus overcome their weaknesses. With advances in nanotechnology, the peptide-based vaccine could incorporate other components, thereby modulating the immune system response against breast cancer. Considering that peptide-based vaccines seem to show remarkably promising outcomes against cancer, this review focuses on and provides a specific view of peptide-based vaccines used against breast cancer. Here, we discuss the benefits associated with a peptide-based vaccine, which can be a mainstay in the prevention and recurrence of breast cancer. Additionally, we also report the results of recent trials as well as plausible prospects for nanotechnology against breast cancer.

Natural Polymeric Composites Derived from Animals, Plants, and Microbes for Vaccine Delivery and Adjuvant Applications: A Review.

A key element in ensuring successful immunization is the efficient delivery of vaccines. However, poor immunogenicity and adverse inflammatory immunogenic reactions make the establishment of an efficient vaccine delivery method a challenging task. The delivery of vaccines has been performed via a variety of delivery methods, including natural-polymer-based carriers that are relatively biocompatible and have low toxicity. The incorporation of adjuvants or antigens into biomaterial-based immunizations has demonstrated better immune response than formulations that just contain the antigen. This system may enable antigen-mediated immunogenicity and shelter and transport the cargo vaccine or antigen to the appropriate target organ. In this regard, this work reviews the recent applications of natural polymer composites from different sources, such as animals, plants, and microbes, in vaccine delivery systems.

Antifouling Potential of Ethyl Acetate Extract of Marine Bacteria Pseudomonas aeruginosa Strain RLimb.

Biofouling is defined as the excessive colonization process of epibiotic organisms, ranging from microfoulers to macrofoulers, on any submerged surface in water. Previous research has attempted to explore the antifouling activity of bacterial isolates due to the biofouling problems occurring worldwide. One solution is to inhibit the early stage of fouling using secondary metabolites produced by marine bacteria. This study aims to determine the antifouling activities of the marine microorganism P. aeruginosa and to characterize the bacteria isolated as a potential anti-biofouling agent. The bacterial isolate was cultured and isolated on a media culture. The bacteria culture extract was extracted using ethyl acetate and concentrated prior to the bioassay method. It was screened for antibacterial activities against Gram-positive and Gram-negative bacteria, such as Bacillus cereus, Streptococcus uberis, Pseudomonas sp., and Vibrio parahaemolyticus, using the disk diffusion technique. The extract was investigated to verify its bioactivity in the prevention of biofilm formation following the crystal violet assay and aquarium test. The results indicated the inhibition of activity through biofilm formation, with the highest percentage at 83% of biofilm inhibition at a concentration of 0.1563 mg/mL. The bacterial isolate at a concentration of 5% showed the highest reduction in bacteria colonies in the aquarium test (161.8 × 103 CFU/mL compared to 722.5 × 103 CFU/mL for the blank sample). The bacterial isolate was characterized through phenotypic and genotypic tests for species identification. It was identified as a Gram-stain-negative, aerobic, and long-rod-shaped bacteria, designated as RLimb. Based on the 16S rDNA gene sequencing analysis, RLimb was identified as Pseudomonas aeruginosa (accession number: OP522351), exhibiting a similarity of 100% to the described neighbor P. aeruginosa strain DSM 50071. These results indicated that these isolated bacteria can potentially be used as a substitute for toxic antifoulants to prevent the formation of microfoulers.

The State of the Art of Natural Polymer Functionalized Fe3O4 Magnetic Nanoparticle Composites for Drug Delivery Applications: A Review.

Natural polymers have received a great deal of interest for their potential use in the encapsulation and transportation of pharmaceuticals and other bioactive compounds for disease treatment. In this perspective, the drug delivery systems (DDS) constructed by representative natural polymers from animals (gelatin and hyaluronic acid), plants (pectin and starch), and microbes (Xanthan gum and Dextran) are provided. In order to enhance the efficiency of polymers in DDS by delivering the medicine to the right location, reducing the medication's adverse effects on neighboring organs or tissues, and controlling the medication's release to stop the cycle of over- and under-dosing, the incorporation of Fe3O4 magnetic nanoparticles with the polymers has engaged the most consideration due to their rare characteristics, such as easy separation, superparamagnetism, and high surface area. This review is designed to report the recent progress of natural polymeric Fe3O4 magnetic nanoparticles in drug delivery applications, based on different polymers' origins.

Transcriptomic Signature of Horseshoe Crab Carcinoscorpius rotundicauda Hemocytes' Response to Lipopolysaccharides.

Carcinoscorpius rotundicauda (C. rotundicauda) is one of the four species of horseshoe crabs (HSCs). The HSC hemocytes store defense molecules that are released upon encountering invading pathogens. The HSCs rely on this innate immunity to continue its existence as a living fossil for more than 480 million years. To gain insight into the innate mechanisms involved, transcriptomic analysis was performed on isolated C. rotundicauda hemocytes challenged with lipopolysaccharides (LPS), the main components of the outer cell membrane of gram-negative bacteria. RNA-sequencing with Illumina HiSeq platform resulted in 232,628,086 and 245,448,176 raw reads corresponding to 190,326,253 and 201,180,020 high-quality mappable reads from control and LPS-stimulated hemocytes, respectively. Following LPS-stimulation, 79 genes were significantly upregulated and 265 genes were downregulated. The differentially expressed genes (DEGs) were related to multiple immune functional categories and pathways such as those of the cytoskeleton, Toll and Imd, apoptosis, MAP kinase (MAPK), inositol phosphate metabolism, phagosome, leucocyte endothelial migration, and gram-negative bacterial infection, among others. This study provides important information about the mechanisms of response to LPS, which is relevant for the understanding the HSCs' immune response.

Xestospongia muta Fraction-7 and Linoleic Acid: Effects on SR-BI Gene Expression and HDL Cholesterol Uptake.

Xestospongia muta is a marine sponge belonging to the family Petrosiidae. It is an important source of biologically active marine natural products, with different kinds of essential fatty acids. Scavenger receptor class B type I (SR-BI) is the main receptor for high-density lipoprotein (HDL) cholesterol, which plays a pivotal role in preventing atherosclerosis. It removes cholesterol from HDL cholesterol, returning lipid-poor lipoprotein into blood circulation. The present study investigated the effects of X. muta Fraction-7 and linoleic acid on SR-BI gene expression and HDL cholesterol uptake. In vitro studies of the activity of X. muta and linoleic acid against the therapeutic target for hypercholesterolemia were conducted using the HDL receptor SR-BI via luciferase assay and HepG2 cells. In the present study, Fraction-7 of X. muta showed the highest expression level of the SR-BI gene via luciferase assay. Profiling of Fraction-7 of X. muta by GC-MS revealed 58 compounds, comprising various fatty acids, particularly linoleic acid. The in vitro study in HepG2 cells showed that the Fraction-7 of X. muta and linoleic acid (an active compound in X. muta) increased SR-BI mRNA expression by 129% and 85%, respectively, compared to the negative control. Linoleic acid increased HDL uptake by 3.21-fold compared to the negative control. Thus, the Fraction-7 of X. muta and linoleic acid have the potential to be explored as adjuncts in the treatment of hypercholesterolemia to prevent or reduce the severity of atherosclerosis development.

Effect of Linoleic Acid on Cholesterol Levels in a High-Fat Diet-Induced Hypercholesterolemia Rat Model.

Cardiovascular disease is the leading cause of morbidity and mortality worldwide, accounting for almost one-third of all deaths. The risk factors for developing this disease include high levels of serum total cholesterol (TC), triglycerides (TG), and low-density lipoprotein (LDL), alongside low levels of high-density lipoprotein (HDL). Dietary linoleic acid has been suggested to reduce these risk factors. This study aims to determine the effects of linoleic acid on cholesterol levels, liver function tests, and structural changes in liver tissue in comparison with fenofibrate in a hypercholesterolemic rat model. Thirty-six male Sprague Dawley rats (150-180 g) were divided into non-hypercholesterolemic and hypercholesterolemic groups. Hypercholesterolemia was induced in the rats by feeding them with a high-fat diet for two weeks. After two weeks, the non-hypercholesterolemic and hypercholesterolemic rats were equally divided into six groups (n = 6): control non-hypercholesterolemic rats, non-hypercholesterolemic rats treated with fenofibrate (60 mg/kg), non-hypercholesterolemic rats treated with linoleic acid (5 mg/kg), control hypercholesterolemic rats, hypercholesterolemic rats treated with fenofibrate (60 mg/kg), and hypercholesterolemic rats treated with linoleic acid (5 mg/kg). The changes in the rats' body weight, serum lipid profiles, atherogenic indices, and liver function test results were obtained. The rats' liver tissues were stained for histopathological analysis. The linoleic acid-treated hypercholesterolemic rats exhibited significantly reduced serum TC, TG, LDL, aspartate aminotransferase, and alanine aminotransferase levels, as well as increased HDL levels compared with the control hypercholesterolemic rats. These linoleic acid effects were comparable to those in the fenofibrate-treated hypercholesterolemic rats. In conclusion, linoleic acid possesses early anti-hypercholesterolemic properties, which may be due to the reductions in serum cholesterol levels and mild early structural changes in the liver tissues of hypercholesterolemic rats. Therefore, continued studies on linoleic acid in atherosclerotic and/or obese animal models are suggested.

Comparative transcriptome profiling of horseshoe crab Tachypleus gigas hemocytes in response to lipopolysaccharides.

Horseshoe crabs (HSCs) are living fossil species of marine arthropods with a long evolutionary history spanning approximately 500 million years. Their survival is helped by their innate immune system that comprises cellular and humoral immune components to protect them against invading pathogens. To help understand the genetic mechanisms involved, the present study utilised the Illumina HiSeq platform to perform transcriptomic analysis of hemocytes from the HSC, Tachypleus gigas, that were challenged with lipopolysaccharides (LPS). The high-throughput sequencing resulted in 352,077,208 and 386,749,136 raw reads corresponding to 282,490,910 and 305,709,830 high-quality mappable reads for the control and LPS-treated hemocyte samples, respectively. Based on the log-fold change of > 0.3 or < -0.3, 1338 genes were significantly upregulated and 215 genes were significantly downregulated following LPS stimulation. The differentially expressed genes (DEGs) were further identified to be associated with multiple pathways such as those related to immune defence, stress response, cytoskeleton function and signal transduction. This study provides insights into the underlying molecular and regulatory mechanisms in hemocytes exposed to LPS, which has relevance for the study of the immune response of HSCs to infection.

Mitochondrial DNA sequence of the horseshoe crab Tachypleus gigas.

This paper reports on the complete mitochondrial (mt) genome of a horseshoe crab, Tachypleus gigas (T. gigas), in Kuala Kemaman, Terengganu, Malaysia. Whole-genome sequencing of hemocyte DNA was performed with Illumina HiSeq system and the generated reads were de novo assembled with ABySS 2.1.5 and reassembled using mitoZ against Carcinoscorpius rotundicauda and Limulus polyphemus, resulting in a contig of 15 Kb. Phylogenetic analysis of the assembled mt genome suggests that the Tachypleus gigas is closely related to Tachypleus tridentatus than to Carcinoscorpius rotundicauda.

Horseshoe crab genomes reveal the evolution of genes and microRNAs after three rounds of whole genome duplication.

Whole genome duplication (WGD) has occurred in relatively few sexually reproducing invertebrates. Consequently, the WGD that occurred in the common ancestor of horseshoe crabs ~135 million years ago provides a rare opportunity to decipher the evolutionary consequences of a duplicated invertebrate genome. Here, we present a high-quality genome assembly for the mangrove horseshoe crab Carcinoscorpius rotundicauda (1.7 Gb, N50 = 90.2 Mb, with 89.8% sequences anchored to 16 pseudomolecules, 2n = 32), and a resequenced genome of the tri-spine horseshoe crab Tachypleus tridentatus (1.7 Gb, N50 = 109.7 Mb). Analyses of gene families, microRNAs, and synteny show that horseshoe crabs have undergone three rounds (3R) of WGD. Comparison of C. rotundicauda and T. tridentatus genomes from populations from several geographic locations further elucidates the diverse fates of both coding and noncoding genes. Together, the present study represents a cornerstone for improving our understanding of invertebrate WGD events on the evolutionary fates of genes and microRNAs, at both the individual and population level. We also provide improved genomic resources for horseshoe crabs, of applied value for breeding programs and conservation of this fascinating and unusual invertebrate lineage.

Genome Sequence of Serratia marcescens subsp. sakuensis Strain K27, a Marine Bacterium Isolated from Sponge (Haliclona amboinensis).

Serratia marcescens subsp. sakuensis strain K27 was isolated from sponge (Haliclona amboinensis). The genome of this strain consists of 5,325,727 bp, with 5,140 open reading frames (ORFs), 3 rRNAs, and 67 tRNAs. It contains genes for the production of amylases, lipases, and proteases. Gene clusters for the biosynthesis of nonribosomal peptides and thiopeptide were also identified.