Search Results (2,136)

Saline–alkaline water resources are globally widespread, and their rational development offers significant potential to alleviate freshwater scarcity. Saline–alkaline water aquaculture farming not only affects fish growth and survival but also impairs reproductive and developmental functions. Largemouth bass (Micropterus salmoides), an economically important fish, has demonstrated excellent high tolerance to such environments, in order to investigate the effects of alkaline water aquaculture environments on its growth performance, sex hormone levels, gonadal development, and molecular adaptation mechanisms. In this study, largemouth bass were chronically exposed to freshwater (0.55 mmol/L), low alkalinity (10 mmol/L), or high alkalinity (25 mmol/L) and cultured for 80 days. Alkalinity exposure more severely impacted the growth rate of females. High alkalinity significantly increased the hepatosomatic index and decreased the gonadosomatic index in both sexes; moreover, it induced oxidative stress in both sexes, evidenced by reduced superoxide dismutase (SOD), catalase (CAT), and total antioxidant capacity (TAOC) levels and elevated malondialdehyde (MDA) content. Furthermore, the levels of sex hormones Serum estradiol (E2), 11-ketotestosterone (11-KT), and testosterone were significantly reduced, accompanied by either an elevated ratio of primary oocytes and follicular atresia, or by reduced spermatogenesis. Apoptotic signals appeared in gonadal interstitial cells, with upregulated expression of genes P53, Bax, Casp3, and Casp8. Ultrastructural damage included fewer mitochondria and cristae blurring, further indicating tissue damage causing dysfunction. Transcriptome results showed that oxidative stress damage and energy metabolism imbalance caused by carbonate alkalinity were key to the delayed gonadal development, which was mainly manifested in enrichment of the ECM–receptor interaction and PI3K-Akt signaling pathways in females exposed to low alkalinity, and the GnRH secretion and chemokine signaling pathways in males. Glycosphingolipid biosynthesis and Ferroptosis pathway were enriched in females exposed to high alkalinity, and the Cortisol synthesis and secretion pathway were enriched in males. Overall, high-alkalinity exposure significantly delayed gonadal development in both sexes of largemouth bass, leading to reproductive impairment. Full article

Rift Valley Fever Virus (RVFV) is an arbovirus that predominantly affects sheep, goats, and cattle, causing epizootics in livestock and epidemics in humans. Infection in pregnant livestock leads to high abortion rates and neonatal mortality. In humans, RVFV usually causes a self-limiting febrile illness, but severe forms can develop, such as hepatitis, hemorrhage, encephalitis, and death. In addition, the association between RVFV infection during pregnancy and miscarriages or stillbirths has been documented. RVFV is transmitted by a range of mosquito species, and, due to the diffusion of these insects, the virus has spread in several world regions, making possible the risk of a public health emergency. Nevertheless, research remains limited and cellular pathology is still poorly characterized. This work aimed to fill some knowledge gaps on the comprehension of RVFV pathogenesis. For this purpose, transmission electron microscopy (TEM) was used to analyze cellular modifications associated with RVFV morphogenesis in four human cell lines (HuH-7, LAN-5, A549, and HTR-8/SVneo) derived from liver, brain, lung, and placenta. Our results showed that all four cell lines are permissive to RVFV infection and highlighted differences in the cytopathogenesis associated with the cell type. These findings could have important implications in understanding disease mechanisms and developing antiviral strategies. Full article

Cytoplasmic male sterility (CMS) is a crucial tool for exploiting plant heterosis, though its underlying mechanisms in tobacco remain incompletely understood. In this study, Tobacco CMSK326, derived from a naturally occurring variant of Nicotiana tabacum, exhibited a range of stamen abnormalities, including stamen degeneration, stamen absence, and carpelloid, petaloid, and sepaloid traits. Histological and electron microscopy showed that CMS K326 and its maintainer differentiated at the early bud stage. Analysis of differentially expressed genes (DEGs) revealed abnormal expressions of several key genes, including WUSCHEL (WUS), GLOBOSA (GLO), SUPERMAN (SUP), and auxin-related genes such as AUX22, during bud development. Weighted gene correlation network analysis (WGCNA) identified a module highly correlated with flower development, the tricarboxylic acid cycle (TCA), auxin, and the mitochondrial retrograde regulation signal molecules CDKE1 and KIN10. The promoter regions of 19 out of the 42 hub genes in this module possess auxin cis-response elements. These results point to a correlation between auxin irregularities and stamen development in CMS K326. Full article

Background/Objectives: The global increase in multidrug-resistant (MDR) bacterial infections underscores the urgent need for effective and sustainable antimicrobial alternatives. This study investigates the antimicrobial activity of exometabolite-based formulations (ExAFs), derived from the cell-free supernatants (CFS) of native lactic acid bacteria (LAB) applied individually or in combination thereof, against MDR-Escherichia coli strain L1PEag1. Methods: Fourteen ExAFs were screened for inhibitory activity using time–kill assays, and structural damage to bacterial cells was assessed via scanning and transmission electron microscopy (SEM/TEM). The most potent formulation was further characterized by liquid chromatography–tandem mass spectrometry (LC–MS/MS) employing a Sequential Windowed Acquisition of All Theoretical Fragment Ion Mass Spectra (SWATH) approach for untargeted metabolite profiling. Results: Among the tested formulations, E10, comprising CFS from Weissella cibaria UTNGt21O, exhibited the strongest inhibitory activity (zone of inhibition: 17.12 ± 0.22 mm), followed by E1 (CFS from Lactiplantibacillus plantarum Gt28L and Lactiplantibacillus plantarum Gt2, 3:1 v/v) and E2 (Gt28L CFS + EPS from Gt2, 3:1 v/v). Time–kill assays demonstrated rapid, dose-dependent bactericidal activity: E1 and E10 achieved >98% reduction in viable counts within 2–3 h, at 1× MIC, while E2 sustained 98.24% inhibition over 18 h, at 0.25× MIC. SEM and TEM revealed pronounced ultrastructural damage, including membrane disruption, cytoplasmic condensation, and intracellular disintegration, consistent with a membrane-targeting mode of action. Metabolomic profiling of E10 identified 22 bioactive metabolites, including lincomycin, the proline-rich peptide Val–Leu–Pro–Val–Pro–Gln, multiple flavonoids, and loperamide. Several compounds shared structural similarity with ribosomally synthesized and post-translationally modified peptides (RiPPs), including lanthipeptides and lassopeptides, suggesting a multifaceted antimicrobial mechanism. Conclusions: These findings position ExAFs, particularly E10, as promising, peptide-rich, bio-based antimicrobial candidates for food safety or therapeutic applications. The co-occurrence of RiPP analogs and secondary metabolites in the formulation suggests the potential for complementary or multi-modal bactericidal effects, positioning these compounds as promising eco-friendly alternatives for combating MDR pathogens. Full article

Seedling cultivation of rice (Oryza sativa L.) is a critical initial step in rice production. This study investigated the effects of sowing methods and strigolactone (GR24) on rice seedlings under salt stress. Results showed that drill-sown seedlings exhibited superior quality under normal conditions compared to broadcast-sown seedlings. Salt stress significantly increased the contents of Cl⁻, Na⁺, reactive oxygen species (ROS), and malondialdehyde (MDA), disrupted chloroplast structure and hormonal balance, and reduced gas exchange parameters and chlorophyll fluorescence parameters. Notably, drill-sowing conferred stronger salt tolerance than broadcast-sowing. Exogenous application of GR24 enhanced activities of antioxidant enzymes—including superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase (POD), and catalase (CAT)—and elevated non-enzymatic antioxidant contents such as ascorbic acid (ASA), glutathione (GSH), total phenolics, and flavonoids, alongside related enzyme activities. Concurrently, GR24 reduced Na⁺ and Cl⁻ accumulation, lowered the Na⁺/K⁺ ratio, and increased the contents of K⁺, Ca²⁺, Mg²⁺, and hormones. Consequently, GR24 decreased MDA and ROS levels, protected membrane integrity, reduced electrolyte leakage, repaired chloroplast structure, and improved gas exchange and chlorophyll fluorescence parameters. Due to their superior spatial distribution and photosynthetic efficiency, drill-sown seedlings synergized with GR24 to enhance antioxidant capacity under salt stress, enabling more effective scavenging of peroxidative radicals, stabilization of the photosynthetic system, and mitigation of salt-induced growth inhibition. Ultimately, this combination demonstrated greater stress alleviation than broadcast-sown seedlings. Full article

Toxoplasma gondii is a globally distributed protozoan parasite and a major cause of congenital infections, particularly in South America. Current therapies for congenital toxoplasmosis are limited by toxicity, long treatment regimens, and suboptimal efficacy, highlighting the urgent need for safer and more effective alternatives. In this study, we evaluated the antiparasitic effects of crude ethanolic extract of Brazilian Red Propolis (BRP) and its isolated compounds, focusing on 7-O-methylvestitol, in human trophoblast (BeWo) cells and third-trimester placental explants. Both BRP and 7-O-methylvestitol significantly reduced T. gondii adhesion, invasion, and intracellular replication, without compromising host cell viability. Ultrastructural analyses revealed irreversible parasite damage, and cytokine profiling demonstrated immunomodulatory effects, with enhanced production of interleukin (IL)-6, IL-8, and macrophage migration inhibitory factor (MIF) in BeWo cells and downregulation of IL-6, MIF, and tumor Necrosis Factor (TNF) in infected placental villi. Notably, 7-O-methylvestitol reproduced and, in some assays, surpassed the antiparasitic activity of BRP, suggesting it as a key bioactive constituent responsible for the therapeutic potential of the extract. These findings support the identification of 7-O-methylvestitol as a promising lead compound for structure-based drug design and repositioning strategies, advancing the development of novel, safe, and targeted therapies against congenital toxoplasmosis. Full article

Metabolic syndrome (MetS) is a worldwide problem affecting at least one-third of the population. MetS patients have increased cardiovascular risk associated with an abnormal β-adrenergic response; however, it is not clear how MetS affects the cardiac β-adrenergic system. We analyzed cardiac function and the β-adrenergic response in an experimental model of MetS in rats by recording pressure–volume (PV) loops via an open-chest approach and performed a biochemical characterization of the cardiac β-adrenergic system through ELISA, radioligand binding assays, and Western blotting. Microscopy was employed to evaluate cardiac hypertrophy, fibrosis, and ultrastructure. MetS rats exhibited cardiac dysfunction, evidenced by a reduced cardiac output and ejection fraction, not explained by heart hypertrophy or fibrosis. MetS rats also had an elevated susceptibility to lethal arrhythmia following intra-cardiac administration of the non-selective β-adrenergic agonist isoproterenol, suggesting alterations in the β-adrenergic system. The total serum adrenaline and noradrenaline levels were higher in the MetS animals than those in the control group. The radioligand binding assays indicated no change in the βAR density; however, the Western blot analyses revealed decreased levels of Gα_s proteins and β-arrestin 1, but increased β₂AR and Gα_i protein levels. This study contributes to our understanding of how MetS can alter cardiac function, raising the risk of lethal arrhythmia induced by the β-adrenergic (fight or flight) response and underscores the relevance of therapeutically targeting MetS before its pathological progression toward cardiomyopathy. Full article

Background: The epiphyseal vascularization of long bones generates a particular flow pattern that is important for adequate angiogenesis to be achieved. Imaging reveals that vessel development in murine long bone involves the expansion and anastomotic fusion of endothelial buds. Impaired blood flow leads to defective angiogenesis and osteogenesis and downregulation of Notch signaling in endothelial cells. We examined whether altered blood flow and endothelial signaling via the Notch pathway—a highly conserved cell–cell communication mechanism that regulates angiogenesis and vascular remodeling—contributes to hip joint degeneration. Material and Methods: In our study, we used two groups of patients. The first is a control group of 15 patients without degenerative joint pathology. The second group consists of 51 patients diagnosed with an advanced form of degenerative joint pathology. On both study groups, we used immunohistochemical markers that highlight the endothelium of epiphyseal capillaries, the collagen matrix, and the presence of joint lubricant-secreting cells. Ultrastructural analysis was performed on hematoxylin-eosin slides that were exposed to a surface electron microscope, following a previously tested protocol. Results: The results of our study show that there are numerous anastomoses between epiphyseal vessels and that these capillaries persist even after pathological bone resorption, for a certain period of time. Discussions: Our results are complementary to recent studies on this research topic that emphasize the possibility that the main cause of joint degeneration is vascular. Revascularization of an area of bone demineralization after bone infarction has become a reality. Conclusions: This study opens new perspectives regarding the research on epiphyseal capillary vascularization and the modern concept of morpho functional rehabilitation of the hip joint. Full article

Background/Objectives: Cryptococcus gattii presents a significant threat to healthy individuals. Titan cell formation, a key virulence factor, is influenced by the nutritional environment and plays a critical role in immune evasion and stress resistance. This study investigates the molecular and biophysical changes in titanized C. gattii cells grown in nutrient-rich Neurobasal™ medium, a potent inducer of titan cells. Methods: An integrative approach was used, combining scanning electron microscopy, optical tweezers, fluorescence microscopy, and physicochemical methods to analyze C. gattii cells grown in Neurobasal™ medium and minimal media. Results: Cells grown in Neurobasal™ medium exhibited significant differences compared to those grown in minimal media. These included a thicker and more defined polysaccharide capsule, enhanced capsule elasticity, and the secretion of more elastic polysaccharides. Furthermore, cells grown in the enriched medium showed reduced susceptibility to antifungals and delayed mortality in infection models. Conclusions: C. gattii adapts to nutritional cues by forming titan cells, thereby enhancing its pathogenicity. Targeting nutritional sensing pathways may offer novel therapeutic strategies against cryptococcal infections. Full article

Adenosine signaling plays protective roles in gingival mitochondrial health and inflammation control, with the ectoenzyme CD73 implicated in periodontitis. Here, we investigated the effects of selective adenosine A2a receptor (A2aR) stimulation using the agonist CGS21680 in a mouse model of ligature-induced periodontitis (LIP) and in gingival fibroblast mitochondrial function. Mature C57Bl/6 mice underwent LIP and received daily intraperitoneal injections of CGS21680 (0.1 mg/Kg) or saline. After 8 days, gingival tissues and maxillae were analyzed for alveolar bone loss and Il-1β levels. In parallel, murine gingival fibroblasts (mGFs) were treated with Tnf-α (5 ng/mL) ± CGS21680 (10 µM) to assess mitochondrial function, morphology, and quality control. A2aR activation significantly reduced alveolar bone loss and Il-1β expression in vivo. In vitro, CGS21680 suppressed Tnf-α-induced Cxcl10 and Cxcl12 expressions and enhanced Vegf production. Mitochondrial analysis revealed increased mitochondrial complex levels, membrane potential, and mass, alongside reduced reactive oxygen species (ROS), proton leak, and mitochondrial stress. Ultrastructural studies showed elongated, healthier mitochondria and increased pro-fusion markers, indicating enhanced mitochondrial quality control. Overall, A2aR stimulation attenuates periodontal inflammation and confers mitoprotective effects on gingival fibroblasts, supporting its potential as a therapeutic strategy to both mitigate periodontitis progression and preserve tissue bioenergetics supporting cellular resilience. Full article

Background/Objectives: Dyslipidemia is a prevalent metabolic disorder closely linked to cardiovascular complications and muscular pathologies, often managed using statins such as simvastatin. However, statin-induced myopathy remains a significant treatment-limiting side effect, necessitating the exploration of safe, natural alternatives. Spirulina platensis, a phytochemical-rich marine-derived cyanobacterium, has emerged as a promising bioactive nutraceutical with potent antioxidant and anti-inflammatory properties. This study evaluated the comparative effects of Spirulina platensis and simvastatin in attenuating dyslipidemia-induced skeletal muscle injury in adult male albino rats. Methods: Forty animals were allocated to the control and high-fat diet (HFD) groups. After 4 weeks, the dyslipidemic rats were subdivided into untreated, simvastatin-treated, and Spirulina platensis-treated subgroups. Serum lipid profile, creatine kinase (CK), and malondialdehyde (MDA) levels were assessed. Histological, ultrastructural, and immunohistochemical analyses were conducted to assess muscle fiber integrity and expression of TGF-β1 and Bcl2. Results: Spirulina platensis significantly improved lipid parameters, reduced CK and MDA levels, preserved muscle histoarchitecture, and downregulated fibrotic (↓TGF-β1) and apoptotic (↑Bcl2) responses compared to the dyslipidemic and simvastatin-treated groups. Our results proved that Spirulina platensis ameliorates the effects of statin-associated myopathy while exerting lipid-lowering, cytoprotective, and antifibrotic effects. Conclusion: These molecular and ultrastructural benefits position Spirulina platensis as a promising, natural alternative to statins for managing dyslipidemia and preventing statin-induced myopathy. Future translational and clinical studies are warranted to further validate its efficacy and safety, supporting its broader application in metabolic and muscle-related disorders. Full article

The successful application of assisted reproductive technologies (ARTs), such as in vitro maturation (IVM) and artificial oocyte activation, requires species-specific adaptations. Although these methods are routinely used in laboratory rodents, their use in wild or non-model species remains limited, such as the Spix’s yellow-toothed cavy, a Neotropical species of ecological and reproductive interest. This study evaluated the effects of different concentrations of epidermal growth factor (EGF; 10 or 50 ng/mL) on IVM (Experiment 1) and of 6-dimethylaminopurine (6-DMAP) on artificial oocyte activation (Experiment 2). EGF at 10 ng/mL (93.8% ± 1.6; 84.9% ± 0.7) promoted greater viability and less apoptosis in cumulus cells, compared to 50 ng/mL (83.0% ± 1.6; 78.9% ± 2.7), maintaining cumulus expansion, ultrastructural integrity, and better morphometric quality of oocytes. Thus, this concentration was used in the next step, where oocytes were activated with or without 6-DMAP. After five days, the presence of 6-DMAP increased cleavage rates (69.3% ± 5.0) compared to activation without the compound (53.5% ± 3.5), without significantly affecting morula formation (13.2% ± 3.1 to 17.3% ± 2.9). It is concluded that EGF improves the oocyte microenvironment, while 6-DMAP enhances cleavage, with these being the initial steps in the development of ARTs for Spix’s yellow-toothed cavy. Full article

Gonadal development and spermatogenesis critically influence fish reproductive performance. Neomales (genetically female but functionally male) are indispensable for generating all-female populations, yet their spermatogenesis remains understudied. In the present study, we systematically investigated gonadal maturation in neomales of the large yellow croaker (Larimichthys crocea), an economically important marine species exhibiting sexually dimorphic growth. We examined the growth performance and gonadal development throughout the maturation process in neomales and control males. Results showed comparable growth performance but a temporal divergence in gonadal development: the gonadosomatic index (GSI) of neomales was significantly higher than control males at 400 and 430 days post-hatching (dph), but not at 460 dph during the reproductive period. Histological, ultrastructural (TEM), and immunofluorescence analyses collectively demonstrated that neomale testes contained all major spermatogenic cell types. Their morphological characteristics and expression patterns of key markers—germ cells (vasa), Sertoli cells (sox9a), and meiotic recombination (dmc1)—were similar to control males. These findings enhance understanding of gonadal development and spermatogenesis in neomales, providing a theoretical and technical foundation for large-scale production of all-female large yellow croaker. Full article

Grain chalkiness is an undesirable trait that significantly compromises rice quality, attracting considerable attention from both consumers and breeders. In this study, we characterized the role of the autophagy-related gene OsATG4b in rice grain development. OsATG4b was predominantly expressed in the endosperm. Compared with wild-type plants, OsATG4b-overexpressing lines exhibited significantly reduced grain chalkiness, whereas OsATG4b knockout mutants displayed a marked increase in chalkiness. Importantly, OsATG4b had no significant effect on other major agronomic traits. Ultrastructure analysis of the endosperm and evaluation of seed storage components revealed that the chalky endosperm in OsATG4b Knockout mutants contained loosely packed starch granules, aberrant protein bodies, and reduced levels of seed storage proteins. Furthermore, gene expression analysis indicated that OsATG4b regulates the expression of genes involved in storage protein biosynthesis. Together, these findings demonstrate that OsATG4b plays a critical regulatory role in determining grain chalkiness in rice. Full article

IBV is a key pathogenic agent in poultry, causing significant respiratory and renal diseases. This study investigated NLRP3 inflammasome and pyroptosis involvement in IBV-infected chicken macrophage HD11 cells. IBV infection triggered a time-dependent increase in the release of IL-1β/IL-18, along with the upregulation of inflammasome-related genes. MCC950 treatment, an NLRP3 inhibitor, notably decreased inflammatory markers while enhancing viral replication, highlighting the NLRP3 inflammasome’s function in restricting viral proliferation and mediating immunopathology. Experiments with UV-inactivated IBV demonstrated that active viral replication was essential for inflammasome activation. Pyroptosis was confirmed in IBV-infected HD11 cells through increased LDH release, characteristic ultrastructural damage, and upregulation of pyroptosis-related genes. Additionally, transfection with the IBV nucleocapsid (N) gene alone induced inflammasome activation and pyroptosis, indicating that the N protein is a key viral factor in this process. Our study offers a new understanding of IBV pathogenesis mechanisms and indicates that targeting the NLRP3 inflammasome may serve as a therapeutic approach. Full article