Search Results (1,329)

The genus Oxyuranus, which includes some of the most venomous snakes in the world, presents a complex venom composition with potent neurotoxic and procoagulant effects. This study provides a comparative proteomic analysis of the venom of Oxyuranus microlepidotus (Inland Taipan) and Oxyuranus scutellatus (Coastal Taipan), aiming to elucidate the molecular basis underlying their distinct toxicological profiles. Using high-resolution chromatographic fractionation and LC-MS/MS, we identified a core set of nine protein families shared between both species, including phospholipases A₂ (PLA₂), three-finger toxins (3FTx), natriuretic peptides (NTP), nerve growth factors (NGF), and prothrombin activators (PTA). O. microlepidotus venom exhibited greater diversity of 3FTxs and unique protein families, such as Waprin and 5′-nucleotidases, suggesting lineage-specific functional adaptations. Quantitative analysis revealed a greater relative abundance of PLA₂s in O. scutellatus (66%) compared to O. microlepidotus (47%), whereas 3FTXs were more prominent in O. microlepidotus (33% vs. 9%). These interspecific differences likely underlie the distinct clinical manifestations of envenomation and reflect evolutionary divergence in the venom composition. Our findings provide molecular insights into taipan venom complexity and highlight novel toxin candidates with potential biomedical applications in neurobiology, hemostasis, and anti-infective therapy. Full article

Spiders of the Sicarius genera (Araneae: Sicariidae) are commonly known as six-eyed sand spiders. Of the species described in Latin America, the species S. thomisoides has previously been shown to possess venom with a toxic potential comparable to that observed in the venom of the spider L. laeta. Although identifying the phospholipase D activity in the venom of S. thomisoides, it is still unknown what other components are part of the venom. In this study, we described the identification of the main protein components of S. thomisoides venom, revealing that the phospholipase D family were the majority toxins, followed by Astacin-like metalloproteinases and serine proteases. Additionally, the presence of CRISP-type allergens and peptides from the U-PHTX-Pmx family was identified for the first time in venoms from Sicarius genera. Identifying the components of the Sicarius spider venom is an essential step to understanding its toxicological potential. Full article

Background/Objectives: This study aimed to identify genes linked to phenotypic traits in Apis cerana cerana through a genome-wide association study. Methods: Genomic data was collected from 116 workers across 12 regions in Guizhou Province, China, and 15 morphological traits were measured, including proboscis length, femur length, tibia length, tarsus length, tarsus width, tergite III and IV length, sternite III length, wax mirror length on sternite III, wax mirror slanted length on sternite III, wax mirror interval on sternite III, sternite VI length, sternite VI width, forewing length, forewing width, and cubital index. Then, a genome-wide association study was performed on these traits. Results: The analysis identified 12 SNPs significantly associated with tergite III and IV length, along with 2 SNPs linked to wax mirror length on sternite III, and 7 SNPs related to the wax mirror interval on sternite III. Eleven candidate genes for tergite III and IV length, two genes for wax mirror length on sternite III, and seven genes for wax mirror interval on sternite III were identified. These genes encode proteins involved in Longitudinals, Zinc, Lamin, BTB/POZ, Dyneins, and Phospholipases. Conclusions: The discovered SNPs and their corresponding genes may regulate the lateral and longitudinal development of the tergum and sternum in the A. c. cerana. Continued in-depth research on these aspects will help clarify how these SNPs regulate the tergum and sternum, thereby enhancing economic returns for beekeepers and promoting the conservation of germplasm resources in the native Apis cerana cerana. Full article

One of the main targets for snake venoms in animal and human organisms is the circulatory system. Mechanisms of circulatory system injury within the victim’s body include, among others, the direct effect of snake toxins on structures in blood vessel walls. The interaction of a toxin with cells and the extracellular matrix of the vessel wall may manifest as cytotoxicity, leading to cell death by necrosis or apoptosis, and damage to vascular wall structures. Such interactions may increase capillary permeability, promoting hemorrhage or edema, and may also induce alterations in vascular tone, resulting in changes in blood pressure. Snake toxins may also affect the growth, function, and regenerative ability of the endothelium, thus modulating angiogenesis; some toxins exert protective or anti-atherosclerotic effects. Toxins interacting with the vasculature may be classified as enzymes (phospholipases A₂, metalloproteinases, L-amino acid oxidases, and hyaluronidases), proteins without enzymatic activity (vascular endothelial growth factors, disintegrins, C-type lectins and snaclecs, three-finger toxins, etc.), peptides (bradykinin-potentiating peptides, natriuretic peptides, sarafotoxins), and low-molecular-weight substances. This review summarizes the data on the vascular effects, particularly on the blood vessel wall, exhibited by various classes and groups of snake toxins. Full article

Background/Objectives: The role of the molecular chaperone heat shock protein 90 (Hsp90) in pain and analgesia has been recognized; however, no study to date has investigated its role in facial allodynia during headache. In the current study, we examined the role of Hsp90 and its possible connection to the endocannabinoid system utilizing a rodent model of cortical spreading depression (CSD). Methods: CSD, a physiological phenomenon associated with headache disorders, was induced by cortical injection of KCl in female Sprague Dawley rats. To selectively inhibit Hsp90, 17-AAG was applied on the dura mater 24 h before CSD induction. Periorbital allodynia was assessed by von Frey filaments, while tissue samples were subjected to LC-MS, qPCR, Western immunoblotting, and the GTPγS coupling assay. Results: Increased expression of Hsp90 was selectively observed in the periaqueductal gray (PAG) harvested 90 min after cortical KCl injection, suggesting increased cellular stress from CSD induction. Application of 17-AAG (0.5 nmol) on dura mater 24 h before CSD induction significantly prevented facial allodynia as measured by von Frey filaments. This effect was blocked by injection of the CB₁R antagonist rimonabant (1 mg/kg, ip). The pretreatment with 17-AAG significantly increased the level of anandamide (AEA) in PAG 90 min after cortical insult, as measured by LC-MS. This effect was accompanied by reduced expression of FAAH and increased expression of NAPE-PLD in the same nuclei. Conclusions: These results suggest that Hsp90 inhibition positively modulates the endocannabinoid system, causing pain relief through descending pain modulation in PAG post-CSD. Full article

Patent ductus arteriosus (PDA) constitutes a significant clinical condition, frequently associated with a spectrum of complications that may profoundly compromise the health status of neonates, particularly those born preterm. Multiple predisposing factors—including prematurity, low birth weight, and respiratory insufficiency—have been consistently documented in the scientific literature. In this study, we investigated the influence of genetic polymorphisms in genes associated with the arachidonic acid–prostaglandin metabolic pathway. Specifically, we analyzed polymorphisms in genes encoding phospholipase A2 (rs10798059, rs1549637, rs4375, rs1805017, rs1051931), cyclooxygenase-1 (rs1236913), prostaglandin synthase 2 (rs13283456), and the prostaglandin E2 receptor EP4 (rs4613763). The study cohort comprised 99 preterm neonates born between 24 and 32 weeks of gestation. Genetic analyses were performed to identify polymorphisms in the aforementioned genes. Statistical evaluation demonstrated that selected polymorphic were significantly associated with an increased risk of patent ductus arteriosus development. This study represents a preliminary step toward elucidating the contribution of genetic variability to the pathogenesis of patent ductus arteriosus. Improved understanding of these molecular mechanisms may facilitate the early identification of neonates at increased risk and support the implementation of targeted monitoring and preventive strategies in this high-risk population. Full article

Background: As a globally significant aquaculture species, elucidating the molecular mechanisms underlying the regulation of the Pacific White Shrimp (Litopenaeus vannamei) growth holds substantial scientific and industrial value. This study systematically investigates the role of the LvChia2 gene in governing growth and development through a cross-tissue metabolic network approach. Methods: RNA knockdown (RNAi)-mediated knockdown of LvChia2 significantly impaired growth performance and triggered a tissue-specific metabolic compensation mechanism. Results: This mechanism was characterized by reduced crude lipid content in muscle and adaptive modulation of lipase (LPS) activities in hepatopancreatic and intestinal tissues, suggesting inter-tissue metabolic coordination. Transcriptomic profiling identified 610 differentially expressed genes (DEGs), forming a three-dimensional regulatory network encompassing “energy metabolism, molt regulation, and nutrient utilization.” Key mechanistic insights revealed the following: (1) Enhanced mitochondrial energy transduction through the upregulation of ATP synthase subunits and NADH dehydrogenase (ND-SGDH). (2) The disruption of ecdysteroid signaling pathways via suppression of Krueppel homolog 1 (Kr-h1). (3) The coordinated regulation of nitrogen metabolism through the downregulation of glutamine synthetase and secretory phospholipase A2. These molecular adaptations, coupled with tissue-specific oxidative stress responses, reflect an integrated physiological strategy for environmental adaptation. Conclusions: Notably, this study provides the first evidence in crustaceans of chitinase-mediated growth regulation through cross-tissue metabolic interactions and identifies six core functional genes (ATP5L, ATP5G, ND-SGDH, Kr-h1, GS, sPLA2) as potential targets for molecular breeding. A novel “gut-hepatopancreas axis” energy compensation mechanism is proposed, offering insights into resource allocation during metabolic stress. These findings advance our understanding of crustacean growth regulation and establish a theoretical foundation for precision aquaculture strategies, including genome editing and multi-trait genomic selection. Full article

Phospholipases (PLs) are key enzymes involved in membrane remodeling, structure, and signaling during plant stress responses. This study analyzed early and long-term transcriptional regulation of PL isoforms—PLD (CsPLDα,β,δ,γ,ζ), PLA (CsPLA₂α,₂β, CsPAT1), and PLC (CsNPC3, CsPI-PLC)—in Fortune mandarins exposed to thermal stress. Three conditions were evaluated: heat stress (37 °C, 90–95% relative humidity), cold stress (2 °C), and cold stress in fruit exposed to a prior heat conditioning treatment (3 days at 37 °C) that reduces chilling injury (CI). All genes—except CsNPC3—were rapidly upregulated by heat (4–12 h), suggesting a role as early heat sensors and their putative participation in the heat-induced chilling tolerance. Moreover, after transferring heat-conditioned fruit to cold, CsPLDζ, CsPI-PLC, and CsNPC3 showed marked expression increases, highlighting their relevance in such cross-adaptation. In non-conditioned fruit, CsPLDγ was strongly and consistently induced by cold and associated with CI development, as further confirmed by tissue-specific analysis comparing necrotic and healthy flavedo. Conversely, cold-induced CsPLDα, CsPLDζ, CsPLA₂α, and CsNPC3 may contribute to protective responses via early signaling cascades; although CsPLA₂α might contribute to CI only by 60 days. These findings highlight the isoform-specific and time-dependent regulation of PL genes under thermal stress and their potential role in citrus stress tolerance. Full article

Tuberculosis (TB) is an infection caused by Mycobacterium tuberculosis complex (MTBC), which can be exacerbated by fungal infections. This study evaluated the clinical characteristics and virulence of Candida spp. in patients with tuberculosis. Antifungal sensitivity, phospholipase and proteinase production, biofilm formation, phagocytic index, and reactive oxygen (ROS) and nitrogen (RNS) species were assessed. Candida spp. were isolated from 14 patients, 28.5% women and 71.4% men, mainly from sputum and tracheal secretions. Five (35.7%) patients were co-infected with Mycobacterium, Candida, and HIV. Candida albicans (78.6%) and Candida tropicalis (21.4%) were identified in all 14 patients. All isolates showed sensitivity to amphotericin B and dose-dependent responses to fluconazole (16 μg/mL). Phospholipase activity was detected in 35.7% of the isolates, whereas all isolates showed proteinase activity (100%). A significant difference in phospholipase activity, phagocytosis, and production of reactive oxygen species (ROS) and nitrogen species (RNS) was observed when Candida isolates from patients with TB, living with or without HIV, were compared to Candida isolates from healthy individuals. All isolates were biofilm producers. This study highlights the relevance of mycoses diagnosis in patients with TB, since Candida spp. may be more virulent and contribute to the deterioration of the clinical condition. Full article

Background/Objectives: Dülmen wild horses are kept in a fenced wooden and marsh area around Dülmen in Westphalia, Germany, since 1856. Previous analyses supported early genetic divergence from other domesticated horse populations and the Przewalski horse. Therefore, the objective of this study was to evaluate genetic diversity using high-density genomic data. Methods: We collected 337 one-year-old male Dülmen wild horses, captured at 12 annual auctions, for genotyping on the Illumina GGP Equine Plus Beadchip. All analyses were performed for 63,123 autosomal SNPs. Results: On average, each horse had 27.96 ROH with an average length of 8.237 Mb, resulting in an average genomic inbreeding coefficient F_ROH of 0.107. ROH with a length of 2–4 Mb were most frequent, and the next frequent ROH fall into the length categories of 4–8 and 8–16 Mb. The effective population size (N_e) steadily decreased in the last 100 generations by 4.57 individuals per generation from 498 to 41. We identified 10 ROH islands on equine chromosomes 1, 4, 5, 7, 9, and 10. Only one ROH island on ECA 1 was shared by 45% of the horses. Overrepresented genes of ROH islands were associated with glycerophospholipid catabolism through phospholipase A2 genes, skeletal muscle contraction (TNNI3, TNNT1), synapse activity and structure (CTTNBP2), regulation of inflammatory response (NLRP genes), and zinc finger protein genes, which are involved in many cellular processes and may also act as tumor suppressors and oncogenes. Conclusions: This study highlights the development of genomic inbreeding and shows the importance of the stallions selected for breeding on the genetic diversity of the Dülmen wild horses. The results of this study should be used to develop strategies to slow down increase in inbreeding and prevent transmitting unfavorable alleles from the stallions to the next generation. Full article

Background: Insect-derived proteins constitute an underutilized biological resource requiring urgent exploration to address global food protein shortages. However, their widespread application is hindered by the allergenic potential, particularly phospholipase A2 (PLA2), a highly immunoreactive allergen prevalent in edible insects such as ants and honeybees. Objective: This study systematically investigated the molecular mechanism underlying quercetin-mediated reduction in PLA2 allergenicity, aiming to establish a novel strategy for developing hypoallergenic insect protein resources. Methods and Results: Through integrated computational and experimental approaches, we identified quercetin’s dual non-covalent and covalent binding capabilities with PLA2. Molecular docking revealed robust interactions (the binding energy of −6.49 kcal/mol) within the catalytic pocket. Meanwhile, mass spectrometry specifically identified Cys37 as the covalent modification site, which can bind to quercetin and increase the gyration radius (Rg) of PLA2 within 75–125 ns. Molecular dynamics simulations illustrated quercetin-induced conformational changes affecting critical antigenic epitopes. Murine experiments further confirmed that quercetin-modified PLA2 exhibited significantly reduced IgE reactivity and allergic responses compared to native PLA2, as demonstrated by assessments of anaphylactic behavior, histopathological changes, and measurements of serum IgE antibody and biogenic amine levels. Conclusions: Collectively, these findings provide a transformative approach to safely utilize insect-derived proteins for sustainable nutrition solutions. Full article

With primary membranous nephropathy (pMN), the genetic background is not precisely known. Certain HLA-DQ serotypes however like HLA-DQ 2.5, and single-nucleotide polymorphisms (SNPs) in the phospholipase A2 receptor 1 (PLA2R1) gene pose a risk for the development of pMN. As antigen presentation is linked to a 3-dimensional conformation of the HLA-DQA/DQB dimer, we thought that the specific HLA-DQ haplotype combinations might also be risk factors in the evolution of MN. The HLA-DQ haplotype combinations and the PLA2R1 gene risk variant (rs4664308) genotypes were examined in 67 patients with MN (52 primary, 15 secondary [sMN]) and 77 controls. Based on the presence or absence of PLA2R1 risk alleles, we used a scoring system to assess the risk and to identify protective HLA-DQ haplotype combinations. The HLA-DQ 2.5 serotype was significantly enriched in both pMN and sMN patients compared to the controls. The pMN group had a significantly higher frequency of the PLA2R1 risk allele compared to the sMN group and the controls. HLA-DQ 2.5 appeared to carry the highest risk for the development of pMN, while HLA-DQ 7.5 and 6.2 seemed to be protective. Our results indicate that the HLA-DQ 2.5 probably carries the highest risk in both pMN and sMN, suggesting that this serotype has less specificity for antigens, and it induces an autoimmune response. Here, PLA2R1 played a role in the development of pMN but not in sMN. Full article

Background/Objectives: G protein-coupled receptors (GPCRs) can promote ligand-biased signaling, yet the mechanisms that promote bias are not well understood. We have shown that C-C Chemokine Ligand 19 (CCL19) and CCL21 promote ligand-biased internalization and signaling of C-C Chemokine Receptor 7 (CCR7) in T cells. The roles of GPCR kinases (GRKs) in regulating biased CCR7 internalization and biased signaling in T cells are unclear. GRK2 is a serine/threonine kinase that phosphorylates GPCRs in response to ligand binding and is recruited to the plasma membrane via its C-terminal pleckstrin homology domain to phosphatidylinositol 4,5-bisphosphate (PIP₂). Methods: Human embryonic kidney cells (HEK293) transfected to express wild-type and mutant GRK2 and human CCR7, human T cell lines harboring heterozygous deletions of GRK2, and naïve primary T cells from GRK2 heterozygous (GRK2^+/−) or GRK2^f/f CD4-Cre mice were used to examine the effects of GRK2 on ligand-induced CCR7 signaling in T cells. We used flow cytometry to assay the effect of GRK2 on CCR7 internalization, Fluorescence Resonance Energy Transfer (FRET) to define the effect of GRK2 on CCR7 activation of Gα_i isoforms and transwell migration assays to examine the effect of GRK2 on chemotaxis. Since chemotaxis via CCR7 is mediated by phospholipase Cγ1 (PLCγ1), Western blot assays were used to measure the effect of GRK2 during downstream signaling via phosphorylation of PLCγ1. Results: We found that following CCL19 binding, GRK2 promoted kinase-dependent CCR7 recruitment of arrestin-3, rapid CCR7 internalization and Gα_i3 recruitment to CCR7. In contrast, following binding of CCL21 to CCR7, GRK2 slowed CCR7 internalization, induced recruitment of Gα_i2 to the activated receptor_, and promoted chemotaxis. Since we have shown that CCL21 promotes chemotaxis via PLCγ1, we examined the effect of GRK2 on PLCγ1 activation and found that GRK2 had no effect on CCL21-mediated PLCγ1 phosphorylation. Conclusions: GRK2 promotes differential signaling downstream of CCR7 activation by CCL19 and CCL21 and provides a model for biased signaling downstream of a GPCR driven by GRK2. Full article

This study aimed to describe phospholipase C zeta (PLCζ) deficiency from patients who experienced oocyte fertilization failure following intracytoplasmic sperm injection (ICSI) and to investigate the relationship between sperm DNA fragmentation, chromatin decondensation, and PLCζ. A total of 135 patients participated in this study—65 fertile men and 70 infertile patients— and semen samples were obtained to analyze concentration, motility, and morphology. PLCζ protein levels were assessed by immunofluorescence and quantitative techniques, DNA fragmentation by TUNEL essay, and chromatin decondensation by aniline blue staining. The proportion of spermatozoa presenting PLCζ was significantly lower in infertile patients (18.41 ± 18.84%) compared to fertile controls (67.31 ± 13.79%) (p < 0.001). A significant decrease in PLCζ protein levels was observed in infertile patients compared to fertile controls, which was the same for localization patterns for each region (acrosomal, equatorial, and combination of these regions). Significant correlations were also observed between sperm parameters and PLCζ levels, DNA fragmentation, and chromatin decondensation. Furthermore, a statistically significant correlation was detected between the percentage of spermatozoa presenting PLCζ and DNA integrity (p < 0.001). In summary, DNA fragmentation and chromatin decondensation are associated with alterations in the localization patterns and reduced protein levels of PLCζ, which may contribute to total fertilization failure. Full article

Although the pancreas is the organ that produces the most critical digestive enzymes, there are other important contributors to the cleavage of food into absorbable units. Pre-pancreatic digestion of carbohydrates occurs through the action of salivary amylase. Pre-pancreatic digestion of fats is mediated by lingual and gastric lipases, and their action may be important as a signal for coordinated digestion. Pepsin, which is present in the stomach, initiates the digestion of dietary proteins into peptides and amplifies distal proteolysis. The major post-pancreatic intestinal carbohydrate-digesting enzymes are sucrase-isomaltase, maltase-glucoamylase and lactase-phlorizin hydrolase. There are no post-pancreatic mucosal enzymes that act on dietary triglycerides; however, the complete digestion of phospholipids depends on several brush border phospholipases. Intestinal processing is an important contributor to digestion of proteins, although mucosal proteases may serve as signaling proteins rather than as primary adjuncts to dietary protein digestion and absorption. This review describes the role of these non-pancreatic digestive enzymes in supporting nutritional health. Full article