Search Results (2,588)

Objective: Self-assembling peptide nanomaterials are increasingly investigated as modular platforms for vaccine delivery and immune modulation. However, their structure-dependent interactions with immune cells remain insufficiently defined, limiting their early evaluation as peptide nanomaterial. This study evaluated the physicochemical properties and immunological effects of three Sup35 G7-derived self-assembling peptide nanomaterials, G7, G7d, and G7d(PEG)HER2, with particular attention to innate immune compatibility and macrophage responses. Methods: The morphology and surface charge of the peptides were characterized by transmission electron microscopy and zeta-potential analysis. Their cytocompatibility was assessed in THP-1 macrophages, Jurkat T cells, and IM-9 B cells. Transcriptomic and proteomic analyses were integrated to identify immune-cell-specific molecular responses. Cellular uptake, apoptosis, cytokine secretion, and intracellular reactive oxygen species production were further examined in macrophages. In vivo immunization in BALB/c mice was conducted to assess systemic immunoglobulin responses. Results: G7 and G7d assembled into large crystalline aggregates with limited dispersibility, whereas PEGylated G7d(PEG)HER2 formed more uniform nanofibers. All three materials showed positive zeta potentials and relatively low cytotoxicity across the tested immune cell models. Among these cells, macrophages displayed the strongest molecular responses. Integrated transcriptomic and proteomic analyses revealed coordinated alterations mainly involving metabolic remodeling, redox homeostasis, proteasome activity, and mitochondrial-associated pathways, rather than predominant activation of classical pro-inflammatory signaling. Ultrastructural analysis confirmed intracellular uptake of assembled peptides and mitochondrial morphological changes without detectable apoptosis. Cytokine profiling showed reduced secretion of multiple cytokines and chemokines, while G7 induced higher intracellular reactive oxygen species than G7d and G7d(PEG)HER2. In vivo, G7d administration was associated with increased serum IgG levels, whereas G7 showed a moderate effect and G7d(PEG)HER2 exhibited minimal changes; IgM levels remained unchanged. Conclusions: Sup35 G7 based self-assembling peptides exhibit low acute toxicity but induce structure-dependent modulation of macrophage function. Differences in assembly morphology and surface modification may influence systemic humoral responses. These findings support the importance of physicochemical design in evaluating immune compatibility of peptide nanomaterial scaffolds. Full article

Postmenopausal ovarian hormone deficiency (OHD) contributes to overactive bladder (OAB) through oxidative stress, mitochondrial dysfunction, and dysregulated estrogen receptor (ER) signaling. This study investigated whether estradiol (E2) alleviates dysfunction by modulating the ER/Smad/miRNA-200/KLF4/mTOR signaling pathway to restore mitochondrial quality control. Thirty female Sprague-Dawley rats were initially allocated to Sham, Ovariectomy (OVX) and OVX + E2 group; after attrition during the 12-month protocol, six surviving animals per group were included in the principal analyses. The OVX + E2 group received daily intramuscular E2 (IM, 30 μg/kg/day) for one month. Bladder function was assessed via micturition volume and frequency by metabolic cages, cystometrograms, and contractility assays. Mechanisms were analyzed using immunofluorescence, Western blotting, transmission electron microscopy (TEM), and miRNA sequencing. OVX rats exhibited significant overactivity and compromised contractility, accompanied by upregulated ERα and downregulated ERβ/GPER. Molecularly, OHD was associated with the upregulation of the miRNA-200 family (miRNA-200a-3p, miRNA-200b-3p and miRNA-200b-5p), which was accompanied by reduced levels of KLF4 and autophagy proteins (ATG7, ATG12 and Beclin-1), as well as elevated p-mTOR expression. TEM revealed the accumulation of damaged mitochondria with ultrastructural features associated with impaired mitophagy. However, E2 treatment ameliorated these abnormalities. These improvements were associated with the restoration of TGF-β/Smad signaling, downregulation of selected miRNA-200 family members, recovery of KLF4 level, and increased expression of autophagy-related markers, accompanied by improved mitochondrial ultrastructural integrity. This cellular restoration might be correlated with improved urodynamic parameters. E2 might exert therapeutic effects by improving mitochondrial quality, potentially via the ER/Smad/miRNA-200/KLF4 signaling pathway. These findings provided mechanistic insights into estrogen-mediated protection and highlight this proposed signaling pathway as a therapeutic target for postmenopausal OAB. Full article

Background/Objectives: Manganese (Mn) is a neurotoxic trace element whose excessive accumulation in the brain can induce hippocampal damage via oxidative stress, mitochondrial dysfunction, neuroinflammation, and apoptosis. This study investigated whether honokiol (HNK) and its liposomal nanoformulation (HNK-LNPs) can ameliorate Mn-induced hippocampal neurotoxicity by modulating key antioxidant and mitochondrial regulatory pathways. Methods: Male Wistar rats were subjected to Mn exposure to induce hippocampal neurotoxicity and were treated with HNK or HNK-LNPs. We assessed oxidative status via NRF2/HO-1 signaling, antioxidant defenses (glutathione, GPx, SOD, CAT), and oxidative indices (ROS, MDA). Neuroinflammatory markers (NF-κB, TNF-α, IL-1β, IL-6, Iba-1), mitochondrial respiratory chain function and ATP levels, SIRT1/PGC-1α signaling, and neurotransmitter homeostasis were evaluated. We analyzed apoptosis using Bax, Bcl-2, caspase-3, and cytochrome c, along with histopathological and ultrastructural examination of the hippocampus. Results: Mn exposure was associated with NRF2/HO-1 downregulation, depleted endogenous antioxidants, increased ROS and MDA levels, and increased NF-κB–driven neuroinflammation and microglial Iba-1 expression. Mn was further associated with reduced ATP synthesis, dysregulation of SIRT1/PGC-1α signaling, and disrupted neurotransmitter balance, with a pro-apoptotic shift (elevated Bax, caspase-3, cytochrome c; reduced Bcl-2) and neuronal degeneration. Co-treatment with HNK, and more prominently with HNK-LNPs, was associated with reversing these alterations, restoring antioxidant and mitochondrial pathways, dampening inflammatory cascades, normalizing neurotransmitters, and favoring neuronal survival, with many indices approaching control values and consistently surpassing free HNK. Conclusions: Liposomal encapsulation significantly enhances honokiol’s neuroprotection against Mn-induced hippocampal neurotoxicity, likely via improved CNS bioavailability and coordinated modulation of NRF2/HO-1 and SIRT1/PGC-1α pathways. These findings support HNK-LNPs as a promising multi-mechanistic therapeutic strategy for metal-induced and related neurotoxic brain disorders. Full article

This study evaluated the effects of reduced inclusion levels of coated inorganic compound trace elements as a reduced substitution for uncoated inorganic trace elements in layer breeder diets. A total of 360 Hy-Line Brown layer breeder hens were randomly assigned to three groups, with six replicate pens of 20 hens per group: control group A (inorganic trace elements), group B (500 mg/kg coated inorganic compound trace elements), and group C (1000 mg/kg coated inorganic compound trace elements). Compared with the control, the coated trace element groups significantly increased the laying rate, eggshell strength and yolk color, and decreased the cracked egg rate and feed-to-egg ratio (p < 0.05). Group B had a lower cracked egg rate and a higher egg shape index than group C. Regarding eggshell ultrastructure, group B had a greater effective layer thickness and proportion and a lower mammillary layer thickness and proportion (p < 0.05), while group C presented increased mammillary width. The coated trace elements increased the deposition of Mn, Zn, and Se in eggs and increased serum GSH-Px and Cu-Zn SOD activities and the T3 concentration. No significant differences in hatching performance were observed among the groups. For progeny, groups B and C had higher birth weight, pectoralis muscle weight, and liver weight, as well as improved serum antioxidant indices and intestinal morphology (p < 0.05). The mRNA expression of intestinal tight junction genes was upregulated in group C (p < 0.05) and showed a modest increase in group B. In conclusion, the coated inorganic compound trace elements, when used at reduced inclusion rates, replaced the conventional uncoated inorganic premix without compromising production performance and improved several performance outcomes. The 500 mg/kg inclusion level provided the most balanced improvements in breeder performance and progeny quality while reducing feed costs. These findings suggest that coated mineral technology may sustain productivity at a substantially lower mineral input and may benefit progeny by increasing egg mineral deposition and supporting intestinal development, thereby providing a more sustainable mineral-feeding strategy for breeder hens. Full article

Winter rapeseed suffers severe damage under cold stress, which seriously restricts its growth and yield. However, differences among cultivars in leaf starch and soluble sugar, as well as their underlying molecular regulatory mechanisms under low-temperature stress, remain poorly understood. We hypothesized that winter rapeseed cultivars with differences in cold tolerance would vary in starch accumulation, soluble sugar contents, and expression of the starch and sugar metabolism-related genes under cold stress. This study aimed to investigate differences in starch accumulation, soluble sugar content, and the gene expression patterns involved in the starch and sugar metabolism pathway in the leaves of winter rapeseed (Brassica napus L.) cultivars with contrasting cold tolerance under cold stress. In this study, two winter rapeseed cultivars, cold-tolerant L88 and cold-sensitive T2288, received 24 h cold treatments at 22 °C (control), 4 °C, 0 °C, and −4 °C. Plant morphology and leaf ultrastructure were observed, iodine–potassium iodide (I₂-KI) staining was performed, and the starch, soluble sugar contents (sucrose, fructose, glucose, and maltose) were analyzed for each temperature regime. Transcriptome sequencing was performed exclusively at −4 °C (0 h versus 24 h). Under −4 °C stress, the two cultivars showed the greatest differences in plant phenotype and leaf ultrastructure, with the cold-sensitive cultivar Tianyou 2288 suffering more severe freezing injury. In Longyou 88, chloroplasts in mesophyll cells were swollen and contained fewer starch granules, whereas in Tianyou 2288 some chloroplasts disintegrated and large numbers of starch granules remained undegraded. As the treatment temperature decreased, leaf starch content declined in both cultivars. At −4 °C, starch content in Longyou 88 was 3.84 mg/g lower than in Tianyou 2288. The contents of soluble sugars, sucrose, glucose, and maltose in leaves increased continuously in both cultivars as stress temperature decreased and reached their maximum values at −4 °C. However, fructose content showed cultivar-specific changes. In Longyou 88, fructose content reached its maximum value of 12.59 mg/g at −4 °C, whereas in Tianyou 2288 it peaked at 7.54 mg/g at 4 °C. At −4 °C, fructose content was 6.69 mg/g higher in Longyou 88 than in Tianyou 2288. Transcriptome analysis revealed that after 24 h of −4 °C stress, Longyou 88 had more upregulated differentially expressed genes (DEGs) than Tianyou 2288, whereas the number of downregulated DEGs in Tianyou 2288 was approximately twice that in Longyou 88. The genes BAM1, BAM3, SUS1, SCRK1, TPS9, and E1314, which were involved in the starch and sucrose metabolism pathway, were upregulated in both cultivars, whereas BGL44 was downregulated. These findings indicate that cold-tolerance winter rapeseed is associated with enhanced starch degradation, maintenance of chloroplast structural integrity in mesophyll cells, and increased soluble sugar accumulation, providing potential physiological indicators for cold-tolerance evaluation. Full article

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most prevalent chronic liver disease, characterized by hepatic steatosis, mitochondrial dysfunction, and oxidative stress. Food-derived polyphenols are promising ingredients that modulate cellular metabolism and redox balance. Açaí (Euterpe oleracea Mart.) seed, a polyphenol-rich agro-industrial by-product, has shown hepatoprotective potential; however, no previous study has comprehensively evaluated its effects on key mitochondrial functions in experimental MASLD. Therefore, this study investigated whether açaí seed extract (ASE), administered alone or in combination with physical training, could improve hepatic mitochondrial respiration, biogenesis, ultrastructural integrity, and redox homeostasis in HF diet-fed Sprague–Dawley rats. Male rats were fed a control or HF diet for 16 weeks and treated with ASE (200 mg/kg/day), aerobic training, or both during the final six weeks. ASE reduced hepatic steatosis by approximately 52% compared with the HF group, improved mitochondrial ultrastructure, increased the expression of the mitochondrial biogenesis regulators PGC-1α and NRF-1, with a 3-fold increase in PGC-1α mRNA expression, increased TFAM immunoreactivity, increased PPARα expression, reduced oxidative stress, and restored lipid-driven mitochondrial respiration. Physical training improved glycemic control and mitochondrial structure, with limited effects on mitochondrial function and redox balance. Combined treatment reduced plasma triglycerides by 41%, increased CPT1α expression, and enhanced carbohydrate-supported mitochondrial respiration. These findings provide mechanistic support for further investigation of açaí seed-derived polyphenols as candidates for nutritional strategies targeting MASLD. Full article

Lutein is a dietary xanthophyll carotenoid valued for its antioxidant properties that has been shown to benefit liver health and reduce hepatic lipid accumulation; however, this lipid-lowering effect cannot be fully attributed to its antioxidant activity, and the underlying mechanism remains poorly understood. Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by excessive hepatic lipid accumulation, oxidative stress, and limited therapeutic options. Transcription factor EB (TFEB) coordinates the autophagy–lysosomal pathways involved in cellular lipid clearance, including lipophagy and lysosomal exocytosis, and is sensitive to the cellular redox state; however, whether the antioxidant lutein modulates TFEB-regulated lipid homeostasis remains unclear. HepG2 cells were exposed to free fatty acids (FFAs) to induce intracellular lipid accumulation and co-treated with lutein. TFEB localization and the expression of TFEB-related genes were assessed by immunofluorescence and qPCR, respectively. Immunofluorescence was also used to evaluate lipid droplet accumulation, LC3 content, and LAMP1 localization. Lipid droplet ultrastructure was analyzed by transmission electron microscopy, and extracellular triglyceride levels were measured as a functional readout of lipid extrusion. Lutein attenuated lipid droplet accumulation in FFA-treated cells, increased nuclear TFEB immunoreactivity, upregulated LC3 mRNA expression, and enhanced LC3 colocalization with lipid droplets. Chloroquine abolished the lipid-lowering effect of lutein, supporting an autophagy-dependent mechanism. In addition, lutein increased the abundance of LAMP1-positive compartments, while ultrastructural analysis and elevated extracellular triglyceride levels suggested enhanced lipid extrusion. These findings position the antioxidant lutein as a candidate natural compound whose lipid-lowering action is associated with TFEB nuclear translocation/activation and with the autophagy–lysosomal pathway, warranting further investigation in MASLD. Full article

This study evaluated how culture system and culture medium composition influence the phenotype and functional quality of Talaromyces sayulitensis HC1 conidia. Conidia were produced by solid-state fermentation (SSF) and submerged fermentation (SmF) using two culture medium compositions differing in sucrose and ammonium phosphate concentrations and, consequently, in C:N ratio. Morphological, ultrastructural, physicochemical and functional attributes were analyzed together with the expression of four selected conidiation-related genes (brlA, abaA, fluG and rodA). Conidia produced under SSF were significantly smaller and displayed a more cylindrical morphology and accumulated significantly more melanin than those produced under SmF, whereas SmF-derived conidia exhibited significantly higher relative ergosterol content. Outer cell wall thickness was significantly influenced by both culture system and culture medium composition. Across both culture systems, the medium containing a lower sucrose concentration and a higher ammonium phosphate concentration (C:N ratio 10:1) resulted in significantly higher germination but significantly lower thermotolerance than the medium containing a higher sucrose concentration and a lower ammonium phosphate concentration (C:N ratio 50:1). The medium was also associated with significantly greater melanization. Expression of brlA, abaA, fluG and rodA was generally higher under SSF, although the magnitude of the response varied among genes and culture medium compositions. The integrated analysis revealed that germination and thermotolerance were not necessarily coupled and that culture system and culture medium composition influenced different dimensions of conidial quality. The main innovation of this study is the integration of structural, physicochemical, functional and selected molecular indicators to identify distinct conidial quality profiles relevant to application-oriented production of fungal inoculants. Full article

Rhipicephalus microplus is a cattle ectoparasite responsible for economic losses in livestock systems. The present study aimed to evaluate the essential oil (EO) of Piper hemmendorffii and its major constituent, limonene, for their activity against R. microplus larvae. The EO of P. hemmendorffii and its major compound, limonene, were evaluated against pyrethroid-resistant R. microplus larvae using larval immersion bioassays, biochemical analyses of detoxification enzymes and acetylcholinesterase, and scanning electron microscopy (SEM). The EO showed higher larvicidal potency (LC₅₀ = 10.46 mg/mL; 95% CI: 9.86–11.09) compared to limonene (LC₅₀ = 31.62 mg/mL; 95% CI: 30.86–32.40). Piper hemmendorffii EO affected the following classes of enzymes investigated: α-Esterase (α-EST) activity increased at LC₂₅ and LC₅₀, reaching its highest level at LC₅₀, whereas β-esterase (β-EST) activity increased only at LC₂₅. Cytochrome P450 (CYP450)-associated heme content activity showed a significant increase exclusively at LC₅₀, suggesting a response of the surviving larvae to EO exposure, although this increase does not by itself demonstrate the activation of detoxification pathways. In contrast, limonene did not significantly affect the activity of the three evaluated enzymes. The inhibition of AChE by the EO suggests a possible effect on the cholinergic system, which may be associated with neurotoxic activity, whereas limonene had no significant effect. The absence of detectable ultrastructural changes by SEM suggests that treatment with either EO or limonene did not induce evident external morphological damage to the larval cuticle under the evaluated conditions. EO toxicity seems to be associated with changes in detoxification enzyme and AChE activities, suggesting the involvement of these biochemical pathways in larval response. Full article

Background: Facial nerve regeneration across segmental defects remains challenging despite advances in nerve guidance conduits. Tissue engineering strategies that combine biomaterial scaffolds with bioactive and cellular components may enhance functional and structural nerve repair. This study investigated the regenerative efficacy of a cellulose-based nerve conduit augmented with Matrigel, mesenchymal stem cells (MSCs), and placental extract (PE) in a rat facial nerve gap model. Methods: A 2 mm defect was created at the main trunk of the facial nerve in adult Sprague–Dawley rats. Animals were divided into three groups: control group (Cellulose/Matrigel), group I (Cellulose/Matrigel/MSC), and group II (Cellulose/Matrigel/MSC/PE). Functional recovery was assessed at 2, 4, 6, and 8 weeks postoperatively using slow-motion vibrissa movement analysis, electrically stimulated facial nerve action potential measurements, and facial nerve blood flow by laser Doppler blood flow analysis. Morphological regeneration was evaluated using light microscopy and transmission electron microscopy. Western blotting using facial muscle was performed. Results: All groups exhibited time-dependent facial nerve regeneration. However, group II demonstrated significantly enhanced functional recovery, greater electrophysiological responses, increased nerve blood flow, and superior histological and ultrastructural regeneration compared with the other groups. These improvements were particularly prominent at 6 and 8 weeks postoperatively. Conclusions: The combination of mesenchymal stem cells and PE within a cellulose-based nerve conduit synergistically enhanced facial nerve regeneration. This tissue-engineered strategy may represent an effective approach for improving peripheral nerve repair. Full article

Objectives: This study aimed to explore the cellular injury phenotypes induced by outer membrane vesicles (OMVs) from uropathogenic Escherichia coli (E. coli, UPEC) and Proteus mirabilis (P. mirabilis, P. m) in human renal tubular epithelial HK-2 cells in vitro. Introduction: In urological practice, UPEC and P. mirabilis are representative pathogens of uncomplicated and complicated UTIs, respectively. Both are Gram-negative bacteria, and a notable feature of these bacteria is their ability to secrete OMVs. OMVs are nanoscale vesicles containing lipopolysaccharides (LPS), phospholipids, peptidoglycan, nucleic acids, and various virulence factors such as proteases and toxins. OMVs serve as effective carriers, delivering these toxic substances to host cells, triggering inflammatory responses, cellular damage, and ultimately cell death. Methods: In this study, we cultured standard pathogenic strains of E. coli and P. mirabilis in lysogeny broth (LB) medium until they reached the logarithmic growth phase. OMVs were isolated and identified. The uptake of OMVs by HK-2 cells was observed in vitro, and we evaluated the cytotoxic effects of both types of OMVs by measuring cell viability, oxidative stress, membrane permeability, mitochondrial function, and organelle morphology. Results: The results demonstrated that OMVs from both bacterial strains were efficiently internalized by HK-2 cells. Both OMVs induced oxidative stress, decreased antioxidant capacity, disrupted membrane permeability, and damaged mitochondrial function, leading to cell injury. Interestingly, while the two types of OMVs caused comparable cytotoxicity in terms of cell viability, oxidative stress and mitochondrial membrane potential, they produced distinct patterns of mitochondrial ultrastructural injury: P. mirabilis OMVs primarily caused mitochondrial structural deformation and blurred cristae, while E. coli OMVs led to mitochondrial swelling, cristae breakage, and vacuolization. These findings provide phenotypic evidence and experimental clues for understanding OMV-associated renal tubular epithelial injury caused by different uropathogens. Full article

Telocytes are small mesenchymal cells with unknown hepatic functions. In primary cultures of rat hepatocytes and non-parenchymal liver cells (NPLC), we observed, at a very low incidence, small-sized, highly motile cells. Because these cells fulfill ultrastructural/morphological ‘telocytes hallmarks’, foremost their minuteness and the presence of very thin telopodia, we refer to them as hepatic telocyte-like cells (hTCLs). Unique among hepatic cells and beyond these telocyte characteristics is their high motility and pronounced cell plasticity. Surprisingly, hTCLs display an exceptional exploratory behavior by moving along/between cell borders as well as beneath cells. Their fast motility apart, hTCLs share structural and behavioral similarities with Kupffer cells/macrophages in NPLC cultures, suggesting a relationship between both cell types that needs to be addressed by further investigation. In EGF/insulin-treated hepatocyte cultures, hTCLs’ motility declines, and the cells adopt an extremely small cell body with very long processes. In cultured hepatocyte monolayers, hTCLs associate with dividing hepatocytes, especially during advanced mitosis (cytokinesis). In conclusion, our observations demonstrate the presence of a small population of highly mobile, telocyte-like cells in liver-derived cell cultures, and a correlative association between hTCLs and hepatocytes, hypothetically accounting for an integrative function of this cell type. Full article

Chagas disease, caused by Trypanosoma cruzi, remains a neglected tropical disease of relevance due to its chronic complications and limited therapeutic options. Current treatments, mainly benznidazole and nifurtimox, are limited by toxicity, adverse effects, and reduced efficacy in chronic infection. Therefore, antimicrobial peptides (AMPs) have emerged as promising candidates for identifying new antiparasitic strategies because of their ability to affect multiple cellular targets. In this study, we evaluated the anti-trypanosomal activity, host-cell cytotoxicity, and cellular alterations induced by the human salivary peptide Histatin 5 (Hist 5) against T. cruzi epimastigotes. The reversibility of the antiparasitic effect was assessed through washout assays after 48 h of exposure. Cytotoxicity was evaluated in Vero cells and RAW264.7 macrophages, whereas parasite susceptibility was determined using dose–response curves. The reversibility of the antiparasitic effect was assessed through washout assays after 48 h of exposure. Ultrastructural alterations induced by Hist 5 were analyzed by transmission electron microscopy. Cell death-associated events were assessed using Annexin V/PI staining and TUNEL assays to detect phosphatidylserine externalization and DNA fragmentation, respectively. Reactive oxygen species and nitric oxide production were quantified using 2′,7′-dichlorodihydrofluorescein diacetate (H₂DCFDA) fluorescence and the Griess reaction. Hist 5 showed limited cytotoxicity toward mammalian cells and reduced parasite viability in a time- and concentration-dependent manner. Following peptide removal, parasite growth recovered only partially, indicating that the antiparasitic effect was not completely reversible. Hist 5 also induced marked ultrastructural damage, apoptosis-like cell death, increased intracellular ROS levels, and enhanced NO production. These findings suggest that Hist 5 affects T. cruzi epimastigotes through multiple cellular alterations while exerting limited effects on host-cell viability. Full article

Dengue remains one of the most important mosquito-borne viral diseases worldwide, and vector control continues to be the cornerstone of disease prevention. Vertical transmission has been proposed as a mechanism contributing to the maintenance of dengue virus (DENV) during interepidemic periods. In this study, field-collected egg pools and second-generation eggs derived from field-collected females from the state of Rio de Janeiro were analyzed by RT-qPCR, Sanger sequencing, plaque assay, and transmission electron microscopy. The second-generation egg samples (E1–E4), corresponding to F2 eggs of the AEDES-RIO strain, were all DENV positive. Sample E1 was positive for DENV-1, whereas samples E2–E4 were positive for DENV-4, confirming transovarial vertical transmission. The detection of DENV-1 and DENV-2 in field-collected egg pools further supports the occurrence of vertical transmission. All PCR-amplified viral fragments were confirmed by Sanger sequencing. Furthermore, homogenized egg samples naturally infected with DENV successfully infected Vero cells, demonstrating that the virus remained infectious. Transmission electron microscopy revealed virus-like particles of approximately 50 nm in diameter within egg tissues, providing ultrastructural evidence that corroborated the molecular and virological findings. Collectively, these findings provide additional evidence supporting vertical transmission of DENV in naturally infected Aedes aegypti populations and highlight the potential of egg-based surveillance as a complementary tool for entomological monitoring. However, further longitudinal studies are needed to establish its epidemiological value. Full article

This study investigated age- and sex-related variations in pituitary gonadotroph morphometry and serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) concentrations in 90 clinically healthy dromedary camels (Camelus dromedarius). Animals were grouped into three age categories (2–4, 5–10, and ≥11 years), with equal representation of males and females. The precise reproductive status of the female camels (e.g., estrous stage or pregnancy status) was not determined and should be considered when interpreting the endocrine findings. Immunocytochemical analysis revealed significant age- and sex-related differences in gonadotroph number and morphometric characteristics (p < 0.05). Gonadotroph counts were 8.3 ± 0.4, 9.4 ± 0.5, and 8.1 ± 0.4 cells in the 2–4, 5–10, and ≥11-year age groups, respectively, with males showing a higher overall count than females (9.1 ± 0.4 vs. 8.2 ± 0.3; p < 0.05). Overall cell size, cell area, cell volume, nucleus area, and nucleus volume were also greater in males than females (p < 0.05). The largest nucleus size, nucleus area, and nucleus volume were observed in camels ≥11 years of age, with values of 4.7 ± 0.1 µm, 18.5 ± 0.8 µm², and 60.3 ± 4.1 µm³, respectively. Ultrastructural analysis further showed a significant sex difference in granule size (58.0 ± 0.7 vs. 52.2 ± 0.8 nm) and granule percentage (56.2 ± 3.6 vs. 43.5 ± 3.3% in males and females, respectively; p < 0.05). Serum FSH concentrations were higher in males than females (4.8 ± 0.1 vs. 4.2 ± 0.1 µIU/mL; p < 0.05), whereas LH concentrations were 1.2 ± 0.1 and 1.2 ± 0.1 µIU/mL in males and females, respectively. LH concentration was highest in 5–10-year-old males (1.3 ± 0.2 µIU/mL), while FSH concentration was highest in ≥11-year-old males (4.8 ± 0.2 µIU/mL). Pearson correlation analysis demonstrated significant positive associations between gonadotroph morphometric parameters and circulating gonadotropins, with correlations ranging from 0.52 to 0.74 for cell/nuclear measurements with LH and FSH. Overall, the findings demonstrate marked age- and sex-associated differences in gonadotroph morphology, ultrastructure, and circulating gonadotropin concentrations in dromedary camels, with males generally exhibiting greater gonadotroph dimensions and secretory granule characteristics. These structural and endocrine differences provide evidence of age- and sex-related variation in pituitary gonadotrophic activity, although the findings should be interpreted in light of the cross-sectional design and the undetermined reproductive status of female camels. Overall, these findings demonstrate pronounced age- and sex-associated differences in pituitary gonadotroph morphology, ultrastructure, and endocrine activity, with males generally exhibiting greater cellular and secretory characteristics. The findings provide novel morphological and endocrine evidence of reproductive aging and sexual dimorphism in the dromedary camel pituitary and may contribute to improved understanding of reproductive function across different life stages. However, interpretation should consider the cross-sectional design and the inability to determine the precise reproductive stage of female camels before slaughter. Full article