Search Results (62)

Background/Objectives: Type 2 diabetes (T2D)-associated sarcopenia is characterized by impaired insulin signaling, lipotoxicity, oxidative stress, and progressive muscle loss. Although liraglutide improves glucose control and reduces lipid burden, its ability to preserve muscle integrity under diabetic lipotoxic conditions remains limited. This study investigated whether β-hydroxy-β-methylbutyrate (HMB) could enhance liraglutide-mediated protection against high-glucose plus free fatty acid (HG+FFA)-induced injury in skeletal muscle cells. Methods: Differentiated C2C12 myotubes were exposed to HG+FFA to establish a sublethal lipotoxic model and treated with liraglutide, HMB, or their combination. Cell viability, lipid accumulation, myotube morphology, insulin signaling, glucose uptake, mitochondrial function, reactive oxygen species (ROS), antioxidant gene expression, and atrophy-related signaling were assessed. Results: HG+FFA induced marked lipid droplet accumulation, impaired insulin signaling, reduced glucose uptake, disrupted mitochondrial membrane potential, increased ROS production, suppressed antioxidant gene expression, and promoted an atrophic phenotype characterized by increased atrogin-1 and MuRF1 and reduced myogenic markers. Liraglutide alone reduced large lipid droplets and partially improved insulin signaling but showed limited efficacy in preserving the myotube phenotype. HMB alone exerted modest effects on lipid accumulation but preserved myotube area. Notably, combined HMB and liraglutide treatment more effectively reduced lipid burden, restored insulin signaling and glucose uptake, attenuated mitochondrial dysfunction and oxidative stress, restored antioxidant gene expression, and preserved MyHC-positive area and myotube diameter while suppressing atrogin-1/MuRF1 activation. These protective effects were largely attenuated by rapamycin, indicating at least partial dependence on mTOR-associated signaling. Conclusions: Overall, HMB and liraglutide exert complementary protective effects against diabetic lipotoxic and atrophic stress, supporting the potential utility of this combination strategy for T2D-associated sarcopenia. Full article

Herbicides considered selective to rice are generally evaluated based on their direct crop safety and weed suppression effects, yet it remains unclear whether they may also trigger indirect or context-dependent effects on rice under rice–barnyardgrass co-cultivation. To address this question, we compared rice performance and associated microbial dynamics under six conditions: rice–barnyardgrass co-cultivation and rice monoculture, each treated with a water spray control or sublethal doses of propanil (Pro, 66.7 mg a.i. L⁻¹) or cyhalofop-butyl (Cyh, 5.86 mg a.i. L⁻¹). Barnyardgrass exhibited visible injury and stronger leaf-level oxidative stress responses, whereas rice displayed no discernible phytotoxic symptoms. Nevertheless, under co-cultivation, herbicide treatment significantly suppressed rice growth, with up to 17.8% lower root lengths and 24.8% lower shoot fresh weights, with reductions varying by herbicide and trait. By contrast, comparable suppression was not observed under herbicide exposure or co-cultivation alone, identifying this response as an emergent, context-dependent negative effect. Microbiota reassembly emerged as an early and stage-specific component of the herbicide-associated response under co-cultivation, with the most pronounced changes detected on day 5 and occurring primarily in bacterial communities. Moreover, bacterial community variation was negatively correlated with root length (ρ = −0.664), and urease activity declined under herbicide treatment. Together, these findings indicate that in paddy fields, herbicides act not only on individual plants but also as an external disturbance to the coupled rice–barnyardgrass system, for which microbiota reorganization represents a key component of the ecological response. Our results suggest that herbicide selectivity should be interpreted within a crop–weed–microbiome context, rather than being inferred solely from their direct crop safety and weed suppression effects. Full article

Widespread uses of nuclear materials increase the risk of accidental or intentional radiation exposure, which can result in acute radiation syndrome (ARS). Hematopoietic ARS (H-ARS) occurs at relatively low doses and is potentially lethal without intervention. While several FDA-approved cytokine-based radiomitigators exist, many require repeated dosing, complicating deployment in mass-casualty scenarios. This study evaluated a novel long-acting, murine-reactive granulocyte–macrophage colony-stimulating factor (LA-GM-CSF; mPDM608) as a prophylactic and mitigative countermeasure for H-ARS. Male and female C57BL/6 mice were exposed to lethal or sublethal total body irradiation (TBI) and treated with LA-GM-CSF using single- or multi-dose regimens administered before or after TBI. Safety, 30-day survival, hematologic recovery, bone marrow cellularity, serum GM-CSF pharmacokinetics, endothelial injury markers, and cytokine profiles were assessed using standard hematology, histopathology, ELISA, and multiplex assays. LA-GM-CSF was well tolerated at doses up to 30 mg/kg. Single or limited dosing conferred significant survival benefits compared with vehicle controls, with optimal efficacy observed at lower doses (3 mg/kg). Post-TBI administration as a single dose 24 h after exposure markedly improved survival in both sexes, with stronger hematopoietic recovery in males. LA-GM-CSF accelerated recovery of neutrophils, red blood cells, platelets, hematocrit, and sternal megakaryocytes, prolonged circulating GM-CSF levels, and favorably modulated endothelial injury markers and select cytokines. LA-GM-CSF demonstrates strong potential as a next-generation radiation countermeasure, providing robust survival benefit and hematopoietic recovery with minimal dosing. The results shown here support further development for H-ARS management under the FDA Animal Rule. Full article

A recent publication proposed that the main biological function of chromosomal toxin–antitoxin systems (TASs) in free-living bacteria is to optimize fitness by mediating K Sensing and Control via a Nutrient-Responsive Cybernetic System. Viable cell density data were consistent with analog (continuous) regulation of population dynamics and cellular physiology throughout the life cycle; however, exactly how bacteria utilize TASs to regulate this was not explained in that publication. Two different concepts of injury have been proposed in the field of microbiology: (1) injury due to external physical and chemical stresses, which lead to sublethal (reversible) or lethal (irreversible) injury depending on the degree of injury, and (2) injury due to internal, self-inflicted stresses mediated by TA toxins. While self-inflicted injury due to TA toxins has been recognized as playing a role in growth arrest and dormancy, which can be reversed by repair, there is little support for TA toxins causing irreversible programmed cell death under normal physiological conditions. The purpose of the present paper was to explain how merging the above two concepts of injury might reveal how TASs optimize the fitness of free-living bacteria under normal physiological conditions by continuously regulating the ratio of injury: repair throughout the life cycle. Full article

Conventional antimicrobial air filters often conflate physical interception with true biochemical inactivation, posing secondary aerosolization risks during maintenance. This study developed a lactoferricin B-functionalized polypropylene (LfCF) filter to provide a dual-action mechanism: electrostatic capture and robust contact-killing against bioaerosols. To rigorously decouple these mechanisms, a polyallylamine binder-only (PP+PAA) control was incorporated. Dynamic penetration assays at 10 cm/s revealed that the 2.0 mg LfCF achieved significantly lower viable penetration rates for Escherichia coli (41.2%) and λ phage (46.0%) compared to the PP+PAA control (75.1% and 76.3%). This substantial gap demonstrates instantaneous sublethal injury upon aerodynamic impaction, defined here as “dynamic inactivation.” Crucially, time-dependent elution assays confirmed a >2 log reduction in viable counts for both retained E. coli and λ phage on LfCFs within 60 min, definitively validating its genuine contact-killing capability. Furthermore, the amphipathic lactoferricin B peptide maintained exceptional biocidal efficacy even under high-humidity conditions (70% RH), overcoming the electrostatic shielding typical of traditional biopolymers, without increasing aerodynamic pressure drop. Finally, field validation in a dental clinic demonstrated an 83.3% reduction in airborne viable bioaerosols. As a passive, self-sterilizing engineering control, the LfCF offers a highly reliable intervention for mitigating occupational bioaerosol exposures. Full article

Cuminum cyminum (cumin) is widely used as a culinary spice and medicinal plant, yet its endothelial effects remain poorly defined, and viability-only toxicity tests may miss relevant changes. We evaluated whether four C. cyminum extracts (aqueous, methanolic, acetonic, hexane) induce sublethal endothelial injury (SEI), defined as preserved viability with functional, molecular, and morphological alterations. Human microvascular endothelial cells (HMEC-1) were exposed to increasing extract concentrations, and endothelial viability, migration, molecular responses, and cytomorphology were evaluated. Organic extracts (methanolic, acetonic, and hexane) induced endothelial stress and injury-related responses. Methanolic and acetonic extracts caused concentration- and time-dependent cytotoxicity, accompanied by reduced migration, stress-related gene modulation, and marked morphological damage, whereas the hexane extract induced pronounced cytomorphological disruption and strong NOS2 induction. In contrast, the aqueous extract exhibited minimal cytotoxicity and significantly enhanced endothelial migration, together with FGF2 upregulation and moderate NOS2 induction, consistent with a sublethal, pro-migratory phenotype. Overall, extract composition strongly influenced endothelial responses, demonstrating that SEI can occur in the absence of overt cytotoxicity and highlighting the need to incorporate functional endothelial endpoints into the safety evaluation of herbal and plant-derived extracts. Full article

Chronic exposure to the cyanotoxin microcystin-LR is an emerging environmental driver of non-alcoholic fatty liver disease (NAFLD); however, the initiating molecular events at sub-lethal, environmentally relevant concentrations remain elusive. Current safety guidelines focus primarily on acute injury, potentially overlooking silent metabolic disruption. The present study investigates the early metabolic toxicity of chronic low-dose microcystin-LR (10 µg/L) in a 7-week rat model, specifically focusing on pre-symptomatic perturbations in lipid homeostasis. By integrating biochemical profiling with multivariate systems toxicology (LASSO and PLS-DA), we identified a specific phenotype of “Silent Hepatic Total Cholesterol Accumulation” (T-CHOL +16%, p = 0.01) occurring in the absence of systemic dyslipidemia or overt liver injury. Mechanistic analysis revealed a specific dual failure of cholesterol homeostasis, characterized by the paradoxical upregulation of the influx transporter Ldlr (LASSO coef +0.661) and the suppression of the efflux transporter Abcg1 (PLS1 loading −0.358). Crucially, Ldlr upregulation occurred despite the concomitant transcriptional downregulation of Srebp2 (Spearman ρ = −0.585), indicating a regulatory uncoupling mechanism. We propose that microcystin-LR-induced protein phosphatase 2A (PP2A) inhibition likely drives this uncoupling via a post-transcriptional override—possibly involving ERK/RSK-mediated Ldlr mRNA stabilization. Concurrently, this inhibition appears to block LXR-mediated Abcg1 expression through sustained AMPK hyperactivation resulting from the loss of dephosphorylation. These findings indicate liver-specific cholesterol accumulation as the critical first step of environmental NAFLD pathogenesis, suggesting that current WHO guidelines (1 µg/L) may require re-evaluation regarding metabolic safety. We propose the hepatic Ldlr/Abcg1 ratio as a potential early biomarker for revised risk assessment. Full article

Food systems expose bacteria to repeated nonlethal stresses during primary production, processing, storage, and sanitation. Depending on the type, intensity, and sequence of exposure, these stresses may weaken cells, act synergistically to promote inactivation, or fail to eliminate contamination. Instead, they can alter bacterial physiology in ways that affect survival, recovery, detection, and responses to control measures. This review examines how stress history contributes to persistent food safety challenges. Listeria monocytogenes is used as a central biological model, with relevant comparisons to other foodborne pathogens. Evidence from food-processing and environmental studies shows that repeated sublethal stress can shift bacterial populations toward stress-hardened states. Here, “stress-hardened” refers to reversible physiological changes and the survival of more tolerant cells, not permanent genetic adaptation. These states include sublethal injury, delayed growth, viable but nonculturable cells, biofilm formation, and increased tolerance to later stresses. These outcomes contribute to, but do not fully explain, the persistence of L. monocytogenes in food environments; intrinsic traits such as psychrotrophic growth and interactions with endogenous microflora also play important roles. These factors help explain repeated recovery of L. monocytogenes after sanitation and the underestimation of viable cells by routine culture-based methods, which do not reliably indicate whether pre-stressed cells retain the potential to cause foodborne illness. Many monitoring and validation approaches rely on unstressed laboratory cultures and fixed enrichment protocols. These conditions do not reflect the physiological states encountered in real food systems. As a result, negative test results may reflect limited recovery rather than true absence, and control performance may be overestimated when stress-conditioned populations are not considered. Across the farm-to-fork continuum, stress responses, persistence mechanisms, and detection limitations are closely linked, indicating that stress history should be considered a core element of hazard characterization, monitoring, and control validation. Incorporating stress biology into food safety assessment can improve the realism of verification strategies when combined with risk characterization that considers infectious dose and host susceptibility, and support control strategies under real-world processing and environmental conditions. Full article

Primary graft dysfunction (PGD) remains a major cause of early morbidity and mortality after a heart transplant (HTx). Understanding the donor-related mechanisms involved may help improve organ selection and post-HTx outcomes. This study aimed to explore the association between the donor serum biomarkers of cell death and inflammation and the incidence of PGD and rejection in HTx recipients. We conducted a retrospective, multicenter observational study of brain-dead (DBD) heart donors and corresponding recipients between 2013 and 2019. Donor blood samples were analyzed for inflammatory cytokines, cell death-related proteins, and mitochondrial (mtDNA) and genomic DNA (gDNA). A total of 39 donor–recipient pairs were included. Sixteen recipients developed severe PGD, and five experienced ≥2R cellular rejection. Donors whose recipients developed PGD had significantly lower serum Caspase-3 levels compared to those without PGD (391.6 [101.8–1003.3] vs. 65.3 [40.2–163.3] pg/mL; p = 0.04). A trend toward lower mtDNA/gDNA ratio was also observed in the same group (10.5 [5.4–24.6] vs. 6.5 [3.3–10.7]; p = 0.067). Lower Caspase-3 levels in donor serum were significantly associated with the development of severe PGD in recipients. This may suggest that the sublethal activation of apoptotic pathways in the donor could play a protective role, potentially conditioning the graft to tolerate ischemic injury. Full article

Listeria monocytogenes is a foodborne pathogen capable of contaminating ready-to-eat meat products, e.g., frankfurters. Post-packaging mild heat treatment via water immersion is commonly employed; however, this may be sublethal to cells located in protected niches or beneath the product surface. The objectives of this study were to evaluate thermal injury of L. monocytogenes on frankfurters at single-cell versus population level and to comparatively estimate pathogens’ physiological status. Pork frankfurter-type sausages were inoculated (ca. 7.0–7.5 log CFU/cm²) with L. monocytogenes strain EGDE-e. Heat treatment was performed at 61 °C (max. 60 min) and 64 °C (max. 12 min). To determine the injured subpopulation from the total, tryptic soy agar with 0.6% yeast extract (TSAYE), supplemented or not with 5% NaCl, was used. Plating-based quantification of injured cells was compared to CFDA/PIstained cells analysed by fluorescence microscopy and quantified with Fiji software. Injury was recorded mainly after 2 and 4 min at 64 °C, whereas no injury was detected at 61 °C, at population level. Following exposure to 61 °C for 60 min, culturable cells dropped below the enumeration limit (0.3 log CFU/cm²), while a considerable number of CFDA⁺/PI⁻ and CFDA⁺/PI⁺ cells indicated viable-but-non-culturable induction and sublethal injury, respectively. These findings suggest that non-culturability may limit the accuracy of solely culture-based enumeration methods. Full article

Lead is among the most toxic heavy metals, posing significant risks to all living organisms. It is a pervasive and persistent contaminant in the environment. Ingested lead in birds and wildlife induces a range of sublethal effects that disrupt physiological functions and behavior, ultimately resulting in mortality at higher doses or with prolonged exposure. To investigate the relation of lead to accidents and injuries in wild birds, we analyzed lead concentration in 43 wild birds that were admitted as patients to the Wildlife Rehabilitation and Breeding Center (WRBC). The findings reveal a significant dependency between the detected levels of lead in the birds’ bone samples and the reported etiology of their injuries, with variances in the age groups of the patients received at the WRBC in Bulgaria. Full article

Plasma-activated water (PAW) treatment is a promising technique for food processing, but it causes sublethal injury (SI) to microorganisms. This study investigated the effect of ultrasound (US) combined with PAW (US-PAW) on SI of Escherichia coli (E. coli). Results showed that, after plasma activation for 10 min and treatment for 10 min, the US-PAW treatment caused a 4.89 ± 0.07 log CFU/mL reduction in E. coli. Meanwhile, under these conditions, the SI rate of E. coli was decreased to 13.3 ± 2.15%, significantly reduced by 52.74% compared to using PAW alone. The inactivation process of US-PAW treatment fitted the Weibull model better. The morphology of E. coli was destroyed by PAW and US-PAW treatment. Additionally, US-PAW treatment significantly increased the leakage of protein and nucleic acid, as well as cell membrane permeability and potential. Compared to PAW or US treatment, the proportion of membrane fatty acids and the structure of membrane proteins were altered in the US-PAW group. Furthermore, intracellular reactive oxygen species (ROS) levels increased by US-PAW treatment, and the levels of GSH, SOD, and CAT enzyme activities were significantly reduced, compared to PAW or US treatment. The combined treatment also resulted in significant DNA oxidative damage. The disruption of cell membrane structure and oxidative damage caused by US-PAW treatment resulted in irreversible damage to bacteria, thus reducing the SI rate. Full article

The aim of this study was to compare the succession of natural microbiota in pork held under refrigerated storage for up to 10 days after dielectric barrier discharge (DBD) plasma treatment. Two methods were used to assess the impact of DBD on microorganisms. Firstly, traditional selective media (SM) were employed to detect the bactericidal effects of DBD on Pseudomonas spp., Enterobacteriaceae, Lactic acid bacteria (LAB), and Brochothrix thermosphacta. Secondly, the thin agar layer (TAL) method was used to further evaluate the bactericidal effects of DBD. In addition, the Baranyi and Roberts model was applied to explore the kinetic parameters of Pseudomonas spp., Enterobacteriaceae, LAB, and B. thermosphacta during storage. Finally, the modified Lotka–Volterra model was used to describe the interactions between each microorganism. The study found that when using traditional selective media (SM), 85 kV DBD had a significant bactericidal effect on Pseudomonas spp., Enterobacteriaceae, LAB, and Brochothrix thermosphacta. However, when using the thin agar layer (TAL) method, the results suggested that DBD had no significant bactericidal effect, suggesting that DBD caused sublethal damage to the natural microorganisms on pork. Analysis with the Baranyi and Roberts model showed that DBD treatment significantly extended the lag phase of these four types of microorganisms and significantly reduced the μ_max of all microorganisms except LAB. The analysis results of the modified Lotka–Volterra model showed that LAB had a greater impact on Pseudomonas spp., Enterobacteriaceae, and B. thermosphacta (a₂₁ > a₁₂). In conclusion, DBD treatment was shown to have a significant sublethal bactericidal effect that impacted both the count and composition of natural microorganisms found on pork. Full article

The intestinal tract is a typical radiosensitive tissue, and radiation rectal injury is a severe side effect that limits the prescribed dose in radiotherapy of the abdominal and pelvic region. Understanding the post-irradiation kinetics of Lgr5-positive stem cells is crucial in comprehending this adverse process. In this study, we utilized Lgr5-EGFP knock-in mice expressing EGFP and LGR5 antibody fluorescence staining of wild-type mice. At the state of radiation injury, the qPCR analysis showed a significant decrease in the expression level of Lgr5 in the rectal epithelial tissue. The dose-response relationship analysis showed that at low to moderate doses up to 10 gray (Gy), Lgr5-clustered populations were observed at the base of the crypt, whereas at sublethal doses (20 Gy and 29 Gy), the cells exhibited a dot-like scatter pattern, termed Lgr5-dotted populations. During recovery, 30 days post-irradiation, Lgr5-clustered populations gradually re-emerged while Lgr5-dotted populations declined, implying that some of the Lgr5-dotted stem cell populations re-clustered, aiding regenerations. Based on statistical analysis of the dose-response relationship using wild-type mice, the threshold dose for destroying these stem cell structures is 18 Gy. These findings may help set doses in mouse abdominal irradiation experiments for radiation intestinal injury and for understanding the histological process of injury development. Full article

The present study used the adult earthworm Aporrectodea trapezoides as a bioindicator species to look into the possible dangers of ammonium sulfate (AS) fertilizer. Two complementary toxicity tests were conducted to determine the LC50values, growth rate inhibition, morphological alterations, and histopathological texture of worms. The lethality test included four increasing concentrations of AS fertilizer (ranging from 2500 to 7500 mg/kg of dry soil weight (d.w.)), while sub-lethal concentrations were based on 10%, 30%, 40%, and 50% of the 14-day median lethal concentration (LC50), with a control group included for both tests. The LC₍₅₀₎ values for AS fertilizer were significantly higher at 7 days (4831.13 mg/kg d.w.) than at 14 days (2698.67 mg/kg d.w.) of exposure. Notably, earthworms exhibited significant growth rate inhibition under exposure to various concentrations and time durations (14/28 exposure days). Morphological alterations such as clitellar swelling, bloody lesions, whole body coiling and constriction, body strangulation, and fragmentation were accentuated steadily, with higher concentrations. Histopathological manifestations included severe injuries to the circular and longitudinal muscular layers, vacuolation, muscle layer atrophy, degradation of the chloragogenous tissue in the intestine, collapsed digestive epithelium of the pharynx with weak reserve inclusion, and fibrosis of blood vessels. These effects were primarily influenced by increasing concentrations of fertilizer and time exposure. The study highlights the strong relationship between concentration and exposure time responses and underscores the potential of A. trapezoides earthworms as valuable biological control agents against acidic ammonium sulfate fertilizer. Importantly, this research contributes to the use of such biomarkers in evaluating soil toxicity and the biological control of environmental risk assessment associated with chemical fertilizers. Full article