Search Results (145)

Neuroinflammation is a key feature of Alzheimer’s disease (AD), and stem cell therapies have emerged as promising candidates due to their immunomodulatory properties. Neuro-Cells (NC), a combination of unmodified mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs), have demonstrated therapeutic potential in models of central nervous system (CNS) injury and neurodegeneration. Here, we studied the effects of NC in APPswe/PS1dE9 mice, an AD mouse model. Twelve-month-old APPswe/PS1dE9 mice or their wild-type littermates were injected with NC or vehicle into the cisterna magna. Five to six weeks post-injection, cognitive, locomotor, and emotional behaviors were assessed. The brain was stained for amyloid plaque density using Congo red, and for astrogliosis using DAPI and GFAP staining. Gene expression of immune activation markers (Il-1β, Il-6, Cd45, Tnf) and plasticity markers (Tubβ3, Bace1, Trem2, Stat3) was examined in the prefrontal cortex. IL-6 secretion was measured in cultured human monocytes following endotoxin challenge and NC treatment. Untreated APPswe/PS1dE9 mice displayed impaired learning in the conditioned taste aversion test, reduced object exploration, and anxiety-like behavior, which were improved in the NC-treated mutants. NC treatment normalized the expression of several immune and plasticity markers and reduced the density of GFAP-positive cells in the hippocampus and thalamus. NC treatment decreased amyloid plaque density in the hippocampus and thalamus, targeting plaques of <100 μm². Additionally, NC treatment suppressed IL-6 secretion by human monocytes. Thus, NC treatment alleviated behavioral deficits and reduced amyloid plaque formation in APPswe/PS1dE9 mice, likely via anti-inflammatory mechanisms. The reduction in IL-6 production in human monocytes further supports the potential of NC therapy for the treatment of AD. Full article

Pharmaceuticals such as fluoxetine, paroxetine, sertraline, and mianserin occur in aquatic environments at low yet persistent concentrations due to their incomplete removal in wastewater treatment plants. Although frequently detected, these neuroactive compounds remain underrepresented in ecotoxicological assessments. Given their pharmacodynamic potency, environmentally relevant concentrations may induce sublethal effects in non-target organisms. In this study, we applied untargeted LC-MS-based metabolomics to investigate the sublethal effects of four widely used antidepressants—paroxetine, sertraline, fluoxetine (SSRIs), and mianserin (TeCA)—on two ecologically relevant freshwater invertebrates: S. ambiguum and D. magna. Organisms were individually exposed to each compound for 48 h at a concentration of 100 µg/L and 25 µg/L, respectively. Untargeted metabolomics captured the sublethal biochemical effects of these antidepressants, revealing both shared disruptions—e.g., in glycerophospholipid metabolism and cysteine and methionine metabolism—and species-specific responses. More pronounced pathway changes observed in D. magna suggest interspecies differences in metabolic capacity or xenobiotic processing mechanisms between taxa. Among the four antidepressants tested, sertraline in D. magna and fluoxetine in S. ambiguum exerted the most extensive metabolomic perturbations, as evidenced by the highest number and pathway impact scores. In D. magna, fluoxetine and mianserin produced similar metabolic profiles, largely overlapping with those of sertraline, whereas paroxetine affected only a single pathway, indicating minimal impact. In S. ambiguum, paroxetine and mianserin elicited comparable responses, also overlapping with those of fluoxetine, while sertraline triggered the fewest changes. These results suggest both compound-specific effects and a conserved metabolic response pattern among the antidepressants used. They also underscore the considerable potential of metabolomics as a powerful and sensitive tool for ecotoxicological risk assessments, particularly when applied across multiple model organisms to capture interspecies variations. However, further research is essential to identify which specific pathway disruptions are most predictive of adverse effects on organismal health. Full article

The increasing release of nanoparticles into aquatic environments, particularly via wastewater, raises concerns about their biological effects on microbial communities. This study investigated the molecular response of Pseudomonas putida to aluminum oxide nanoparticles (Al₂O₃NPs) under controlled conditions and in synthetic wastewater, both before and after biological treatment. Acute toxicity was evaluated using growth inhibition assays, while the expression of katE, ahpC, and ctaD—genes associated with oxidative stress and energy metabolism—was quantified via RT-qPCR. Exposure to pristine Al₂O₃NPs induced a strong, time-dependent upregulation of all tested genes (e.g., katE and ahpC up to 4.5-fold). In untreated wastewater, this effect persisted but at a lower intensity; bulk Al₂O₃ caused only moderate changes. Treated wastewater samples showed markedly reduced gene expression, indicating partial detoxification. Nanoparticles elicited stronger biological responses than their bulk counterparts, confirming the material form-specific effects. Comparative analysis with Daphnia magna revealed similar patterns of oxidative stress gene activation. These findings highlight the influence of nanoparticle form and environmental matrix on microbial responses and support the use of gene expression analysis as a sensitive biomarker for nanoparticle-induced stress in environmental risk assessment. Full article

The crustacean Daphnia magna produces genetically identical females and males by parthenogenesis. Males are produced in response to environmental cues including crowding and lack of food. For male development, the DM-domain containing transcription factor Doublesex1 (DSX1) is expressed spatiotemporally in male-specific traits and orchestrates male trait formation in both somatic and gonadal tissues. However, it remains unknown how the dsx1 gene is silenced in females to avoid male trait development. Heterochromatin Protein 1 (HP1) plays a crucial role in epigenetic gene silencing during developmental processes. Here we report the identification of four HP1 orthologs in D. magna. None of these orthologs exhibited sexually dimorphic expression, and among them, HP1-1 was most abundantly expressed during embryogenesis. The knock-down of HP1-1 in female embryos led to the derepression of dsx1 in the male-specific traits, resulting in the development of male characteristics, such as the elongation of the first antennae. These results suggest that HP1-1 silences dsx1 for female development while environmental cues unlock this silencing to induce male production. We infer the HP1-dependent formation of a sex-specific chromatin structure on the dsx1 locus is a key process in the environmental sex determination of D. magna. Full article

The widespread use and pseudo-persistent occurrence of the antidepressant citalopram (CIT) could pose a potential ecological risk in the aquatic environment. The message about the bioconcentration and sensitive biomarker identification of CIT at the environmentally relevant concentrations is limited. In this study, an integral evaluation of the phenotypic and biochemical effects of CIT on Daphnia magna (D. magna) was conducted at 0.5 and 10 µg/L. The biomarker screening includes energy metabolism, phototactic behavior, feeding dysfunction, and antioxidant stress responses. The carbohydrate, lipid, and protein content was determined using the assay of anthrone with glucose as standard, thiophosphorate-Vaniline with cholesterol as standard, and Coomassie brilliant blue with serum albumin as standard, respectively. The results showed the bioconcentration equilibrium of CIT reached at the exposure duration of 48 h during the uptake process. At the exposure concentrations of 0.5 and 10 µg/L, the bioconcentration factor of CIT was 571.2 and 67.4 L/kg, respectively. Both protein and lipid content significantly increased at 0.5 µg/L with a 1.78-fold elevation in total energy. Comparatively, the lipid content showed a significant increase at 10 µg/L, while the available total energy rose by 1.25-fold relative to the control group. The phototactic behavior of D. magna exposed to 0.5 µg/L CIT was markedly reduced at 48 h relative to control. In contrast, a significant decrease in phototaxis was observed after 6 h and then a significant increase at 12 h with a continuously obvious decline at 10 µg/L. The filtration rates were increased by 32% compared to controls at 0.5 µg/L, while the stimulatory effects disappeared at 10 µg/L. With regarding to the antioxidant enzyme activities, CIT exposure significantly inhibited the catalase activity both at 0.5 and 10 µg/L, while the glutathione S-transferase activity was obviously induced at 0.5 µg/L and inhibited at 10 µg/L. The expression level of 18s gene was significantly decreased at 10 µg/L. Only the gst gene expression level was significantly increased at 0.5 µg/L, while the 18s and cat gene expression level was obviously inhibited and induced at 10 µg/L. Comprehensively, the responses of the phenotypic traits and energy metabolism of D. magna at various environmental concentrations were sensitive for CIT. This study provided basic data for the risk estimation of CIT in the real freshwater environment. Full article

This study explores the interaction between Prymnesium parvum and Daphnia magna under low-salinity conditions. P. parvum showed reduced growth below 0.4 PSU and peaked at 1.0 PSU within the tested 0.2–1.0 PSU range. D. magna, exposed to P. parvum across 0.0–6.0 PSU, experienced increased mortality at 4.0 and 6.0 PSU, but tolerated 0.0–1.0 PSU well and grazed actively on P. parvum without significant vitality loss. This range reflects conditions observed in the Oder River during the 2022 fish die-off. The count of P. parvum cells did not vary significantly across the 0.2 to 1.0 PSU range of salinities in D. magna presence, except at 0.6 PSU. All daphnids survived even at P. parvum densities of 1 × 10⁵ cells/mL, though increasing algal concentrations reduced juvenile growth rates. Direct observation under a microscope confirmed algal ingestion. Toxin accumulation in cells and medium likely reduced grazing efficiency via allelopathic effects. The study assessed whether D. magna can tolerate prymnesins while maintaining feeding under varying salinities. Results suggest that Daphnia magna could act as a biological suppressor of golden algae under certain environmental conditions, though further work is needed to quantify grazing efficiency and prymnesins concentrations. Full article

The widespread availability and pseudo-persistence of typical psychiatric pharmaceuticals (PDs) can have serious impacts on aquatic ecosystems and even human health. However, the toxicokinetics of typical PDs and the corresponding enzymatic biomarker responses are unclear. In this study, eight typical PDs [carbamazepine (CBZ), citalopram (CIT), sertraline (SER), venlafaxine (VLF), amitriptyline (AMT), chlorpromazine (CPM), quetiapine (QTP) and clozapine (CLZ)] were selected to study the uptake, depuration and biological effects of PDs in Daphnia magna. The results found that the uptake rates (K_u) were in the sequence of VLF < QTP < CBZ < CLZ < CIT < AMT < SER < CPM, while the depuration rates (K_d) were in the order of CLZ < AMT < CIT < SER < QTP < CBZ < CPM < VLF. Correspondingly, the bioconcentration factors (BCFs) followed on as VLF < QTP < CBZ < CIT < AMT < CLZ < SER < CPM. Both pH-dependent octanol–water partition coefficients (log D_ow) and liposome–water partition coefficients (log D_lip-w) exhibited positive correlations with the log BCF of PDs (p < 0.05), indicating the important roles of ionization degree and biological phospholipid contents on bioconcentration. Superoxide dismutase (SOD) activities were evidently induced in the SER and CPM groups, while ethoxyresorufin-O-deethylase (EROD) and glutathione-S-transferase (GST) activities were significantly induced only in the CBZ group. Acetylcholinesterase (AChE) activity was obviously induced by CBZ, SER and AMT, with levels 1.73, 1.62 and 2.44 times that of the control group (p < 0.05). The K_u of PDs, oxidative stress and metabolic level of D. magna combine to affect BCF levels together. In conclusion, this study contributes to a better understanding of the toxicokinetics and biochemical responses of PDs in D. magna and potential mechanisms of action, which may allow for a better assessment of their environmental health risks to aquatic ecosystems. Full article

Freshwater cyanobacterial harmful algal blooms (FCHABs) alter zooplankton communities, often adversely, through the production of cyanotoxins. While Daphnia magna is frequently used to evaluate the impact of toxicants, it is not commonly found in tropical waters; cladocerans from tropical and subtropical waterbodies should be used in bioassays. Here, we evaluated the impact of crude cyanobacteria extracts on three common, native species (Daphnia laevis, Ceriodaphnia dubia, and Simocephalus vetulus) based on acute and chronic bioassays. We analyzed the toxicity of cyanobacterial consortium collected from Lake Zumpango, Mexico. The FCHAB was dominated by Planktothrix agardhii (1.16 × 10⁶ ind mL⁻¹). A series of freeze/thaw/sonification cycles at 20 kHz was used to extract the toxic metabolites and the concentration of dissolved microcystin-LR equivalents was measured using an ELISA immunological kit. S. vetulus was the most sensitive species, with a median lethal concentration of 0.43 compared to 1.19 µg L⁻¹ of D. magna at 48 h. S. vetulus was also the most sensitive in chronic evaluations, showing a negative rate of population increase (−0.10 d⁻¹) in experiments with 20% crude extract. Full article

The growing need for sustainable protein sources in aquaculture has led to interest in microalgae, such as Chlorella vulgaris, known for its high nutritional value. One promising strategy for delivering these nutrients is through bioencapsulation in Daphnia magna, a common live feed used in aquaculture. This study evaluated the effect of including D. magna bioencapsulated with C. vulgaris as live feed for marine shrimp Penaeus vannamei post-larvae. Shrimp were fed at two D. magna densities (5 and 10 per shrimp, 5DF and 10DF), offered weekly, and compared with a control group receiving only commercial feed (F) for 36 days in a synbiotic nursery system. Water quality, zootechnical performance, protein, and lipid content of the shrimp were analyzed using correlation analyses, nonlinear prediction models, and principal component analysis (PCA). Shrimp fed with the 10DF treatment exhibited superior zootechnical performance, characterized by a lower feed conversion ratio (1.01) and higher feed efficiency (99.97%), protein (70.91%), and lipid (32.45%) content in comparison with the 5DF and control. Quadratic regression predictive models indicated the possibility of further testing higher concentrations of D. magna per shrimp. The results indicates that the use of C. vulgaris bioencapsulated in D. magna as live feed for P. vannamei is a promising approach to improve shrimp diets and increase production in aquaculture. Full article

The agricultural production process contributes to the global issue of pesticide pollution. Based on the static toxicity test of diuron (DCMU) on Daphnia magna (D. magna) for EC₅₀-48 h, a concentration range of 0.2 to 1 mg/L was set as sublethal concentrations, while lethal concentrations were set at 2 mg/L and 4 mg/L. This study analyzes the toxic response patterns of the swimming behavior indicators of D. magna exposed to different concentrations of DCMU. The results showed that the average speed (V) of D. magna decreased step by step with exposure time, regardless of exposure to sublethal concentration or lethal concentration. However, during the same short-term exposure period, the V of D. magna at lethal concentration was higher than that at sublethal concentration, which indicates that the swimming behavior of D. magna exposed to DCMU may be stimulated and accelerated. Compared to the control group, there is a statistically significant difference in the V of D. magna after short-term exposure, especially showing an extremely significant difference after 5 min of exposure. Evidently, compared to the traditional 48 h static toxicity testing method, the swimming behavior indicators of D. magna show a more sensitive response to DCMU after 5 min of exposure, making it more suitable for rapid toxicity detection. By expanding the range of exposure concentrations, it was found that the V indicator of D. magna responded significantly to a DCMU concentration of 0.05 mg/L after only 5 min of exposure, and a high degree of correlation was observed between the indicator and the exposure concentration. Through nonlinear fitting, the relationship between V and the dose–effect of DCMU toxicity presents an S-shaped curve, with R² > 0.9. Consequently, it becomes possible to study the dose–effect relationship between the changes in the swimming behavior indicators of D. magna and the stress concentration based on this theory. This further establishes a foundation for the development of comprehensive aquatic toxicity rapid detection technology based on the toxic response of swimming behavior indicators. Full article

Catechins, renowned for their health benefits, have unexamined environmental impacts. This study assessed the toxicity of crude catechin and catechin hydrate on invertebrate larvae, plant, and microalgae. The survival rates of Daphnia magna Straus and Artemia salina L. were monitored every 24 h over a three-day period. The germination rate and radicle length of Lactuca sativa L. was measured every 24 h for four days. Inhibitory effects were evaluated in both freshwater and seawater cultures of Chlorella vulgaris Beijerinck, with cell density recorded every 24 h and yield inhibition calculated after 96 h. Results indicated that increasing catechin concentration and exposure duration decreased the survival rate of D. magna and A. salina. Daphnia magna was more sensitive to catechins than A. salina, with 24 h lethal concentration 50 (LC-50) values of 1174 µg/mL compared to 1895 µg/mL for crude catechin, and 54 µg/mL compared to 153 µg/mL for catechin hydrate. The germination rate and radicle length of L. sativa, along with the cell density of C. vulgaris, decreased with increasing catechin concentration, but remained higher even after prolonged exposure. At low catechin concentrations, C. vulgaris cell density exceeded control levels. This study demonstrates that catechins in aquatic environments can significantly impact ecosystems. At certain concentrations, catechins are toxic and potentially lethal to aquatic organisms. Conversely, at lower concentrations, catechins may promote microalgal growth, suggesting a fertilizing effect. Understanding these dynamics is crucial for maintaining the stability of aquatic ecosystems. Full article

The percentage of historical heritage buildings in Italy is substantial. Many of these buildings are abandoned or not adequately restored for public access due to safety concerns. However, some are managed by city councils and made available to local communities. These heritage buildings, valued for their historical significance, are now frequently used for live events, including musical performances by ensembles and small groups. This paper deals with the acoustics of two rooms provided with barrel-vaulted ceilings: Sisto V Hall in Naples and Aula Magna at the University of Parma. These spaces are structurally very similar, differing mainly in length. Acoustic measurements conducted in both halls reveal reverberation times of approximately 4.5 s at mid frequencies, resulting in poor speech clarity. This is primarily due to the presence of reflective surfaces, as the walls and ceilings are plastered, and the floors are tiled. To optimize their acoustic properties for functions such as celebrations, gatherings, and conferences, an acoustic design intervention was proposed. Digital models of the halls were calibrated and used to correct the acoustics by incorporating absorbing panels on the walls and carpeting on the floors of the central walk path. This treatment successfully balanced the reverberation time to approximately 1.3–1.4 s at mid frequencies, making speech more intelligible. Additionally, an amplified audio system was analyzed to enhance sound distribution, ensuring uniform coverage, even in the last rows of seating. Under amplified conditions, sound pressure levels (SPLs) range between 90 dB and 93 dB, with appropriate gain control applied to the column array speakers. Full article

Microplastics (MPs), ubiquitous environmental pollutants, pose substantial threats to aquatic ecosystems and organisms, including the model species Daphnia magna. This study examined the effects of polyethylene (PE) and polystyrene (PS) MPs on D. magna, focusing on their ingestion, epigenetic alterations, and transcriptional responses. Exposure experiments revealed a concentration-dependent accumulation of MPs, with PS particles showing higher ingestion rates due to their higher density and propensity for aggregation. Epigenetic analyses demonstrated that exposure to PE MPs significantly reduced the global DNA methylation (5-mC) of Daphnia magna, suggesting hypomethylation as a potential stress response. Conversely, the DNA hydroxymethylation (5-hmC) of Daphnia magna displayed variability under PS exposure. Transcriptional analysis identified a marked downregulation of Vitellogenin 1 (v1) and upregulation of Ecdysone Receptor B (ecr-b), highlighting the occurrence of stress-related and adaptive molecular responses. These findings enhance our understanding of the molecular and epigenetic effects of MPs on aquatic organisms, offering critical insights for the development of effective environmental management and conservation strategies in the face of escalating MP pollution. Full article

Endocrine disruptors such as 17α-ethinylestradiol pose significant ecological risks in aquatic environments. This study assessed the catalytic performance of Fe- and Cu-impregnated delaminated clays (DCs) and layered double hydroxides (LDHs) in a Fenton-like process for EE2 removal. The effects of key parameters—including hydrogen peroxide concentration, initial contaminant load, and catalyst dosage—were analyzed using HPLC-QqTOF. Delaminated clays (DCs) demonstrated higher removal efficiencies compared to layered double hydroxides (LDHs), reaching 55% with Fe and 47% with Cu, while LDHs achieved 40% and 33% for Fe and Cu, respectively. Ecotoxicity was evaluated using bioassays (L. sativa, S. capricornutum, D. magna) and the Ames test. Notably, S. capricornutum exhibited 100% inhibition at the highest tested concentration, with IC₅₀ values of 11.2–12.4 for Cu and 31.5–32.7 for Fe. L. sativa was inhibited by Cu- and Fe-impregnated LDH/DC, with IC50 values of 71.0 (DC-Cu), 56.6 (DC-Fe), and 58.6 (LDH-Fe). D. magna exhibited 17–75% mortality when exposed to untreated EE2, while LC50 values confirmed Cu’s greater toxicity. The Ames test indicated no mutagenic effects. Integrating the Fenton-like process with complementary techniques is recommended to enhance efficiency. These findings highlight the need to optimize operational parameters for effective removal of 17α-ethinylestradiol. Full article

(4Z,8Z)-Matricaria lactone (MAT) and (4Z)-lachnophyllum lactone (LAC) are natural acetylenic furanones with bioherbicidal potential. This study evaluates their possibilities and ecotoxicological impact on aquatic (Aliivibrio fischeri, Raphidocelis subcapitata, and Daphnia magna) and terrestrial (Caenorhabditis elegans, Lepidum sativum) model organisms. MAT exhibited rapid degradation, with 90% decomposition within 24 h and over 98% by day 16, while LAC was more stable, degrading by only 8.5% in 24 h and 67% by day 16. Despite its rapid breakdown, MAT exhibited higher acute toxicity to A. fischeri (EC₁₀ = 0.063 mg L⁻¹; EC₅₀ = 0.642 mg L⁻¹) compared to LAC (EC₁₀ = 0.524 mg L⁻¹; EC₅₀ = 8.078 mg L⁻¹). Toxicity patterns in R. subcapitata differed, with MAT promoting slightly higher growth compared to the control, suggesting hormetic effects (EC₁₀ = 3.417 mg L⁻¹; EC₅₀ = 4.520 mg L⁻¹), while LAC inhibited growth concentration (EC₁₀ = 0.304 mg L⁻¹; EC₅₀ = 9.880 mg L⁻¹). Both compounds immobilized D. magna, with LAC showing greater delayed toxicity (EC₅₀ = 1.728 mg L⁻¹ vs. MAT EC₅₀ = 2.239 mg L⁻¹). Furthermore, for L. sativum, there were no effects on the germination, but effects were observed in the lengths of the shoots (LAC EC₅₀ = 85.89 mg L⁻¹ vs. MAT EC₅₀ = 82.30 mg L⁻¹). In contrast, C. elegans showed no mortality, suggesting lower terrestrial toxicity. These findings suggest that MAT and LAC may pose risks to aquatic ecosystems through runoff or leaching, necessitating further studies on their degradation products, soil microbiota, and non-target terrestrial organisms. Comparative analyses with conventional herbicides highlight MAT and LAC as selective, lower-impact alternatives. Future research should focus on their effects on terrestrial organisms, the ecological safety of degradation products, and large-scale bioassays to ensure their sustainability in agriculture. Full article