Intervention effects of sulfate glycosaminoglycan from swim bladder against arsenic-induced damage in IEC-6 cells

Amelioration of arsenic-induced hepatic injury via sulfated glycosaminoglycan from swim bladder: Modulation of Nrf2 pathway and amino acid metabolism

Arsenic, a known environmental pollutant with a carcinogenic risk, is associated with chronic liver toxicity. Prebiotic regulation represents an emerging dietary strategy to alleviate arsenic-induced hepatotoxicity; however, research in this area remains limited. This study employed sulfated swim bladder glycosaminoglycan (SBSG), a potential prebiotic, to assess its efficacy in mitigating arsenic-induced liver injury. In basic indicators, SBSG resisted oxidative stress by down-regulating AST, ALT, MDA, and MPO, up-regulating antioxidants (T-SOD, GSH, and GSH-px), and ameliorating histopathological damage. RT-qPCR analysis revealed that SBSG could regulate the Nrf2 signaling pathway and affect the expression of o genes related to ferroptosis and detoxification. The expression of protein further verified that SBSG could play an antioxidant and detoxifying role as an Nrf2 activator. Non-targeted metabolomics results demonstrated that SBSG primarily addresses metabolic disorders by up-regulating D-amino acid metabolism, ABC transporter, and alanine, aspartate and glutamate metabolism. Correlation analysis suggests that SBSG alleviates arsenic-induced liver oxidative damage through mechanisms linked to the Nrf2 pathway and amino acid metabolism. This study provided a research basis for expanding the dietary strategy to reduce arsenic induced toxicity.

Polypyrrole/iron-glycol chitosan nanozymes mediate M1 macrophages to enhance the X-ray-triggered photodynamic therapy for bladder cancer by promoting antitumor immunity

X-ray Photodynamic Therapy (XPDT) is an emerging, deeply penetrating, and non-invasive tumor treatment that stimulates robust antitumor immune responses. However, its efficacy is often limited by low therapeutic delivery and immunosuppressant within the tumor microenvironment. This challenge can potentially be addressed by utilizing X-ray responsive iron-glycol chitosan-polypyrrole nanozymes (GCS-I-PPy NZs), which activate M1 macrophages. These nanozymes increase tumor infiltration and enhance the macrophages' intrinsic immune response and their ability to stimulate adaptive immunity. Authors have designed biocompatible, photosensitizer-containing GCS-I-PPy NZs using oxidation/reduction reactions. These nanozymes were internalized by M1 macrophages to form RAW-GCS-I-PPy NZs. Authors' results demonstrated that these engineered macrophages effectively delivered the nanozymes with potentially high tumor accumulation. Within the tumor microenvironment, the accumulated GCS-I-PPy NZs underwent X-ray irradiation, generating reactive oxygen species (ROS). This ROS augmentation significantly enhanced the therapeutic effect of XPDT and synergistically promoted T cell infiltration into the tumor. These findings suggest that nano-engineered M1 macrophages can effectively boost the immune effects of XPDT, providing a promising strategy for enhancing cancer immunotherapy. The ability of GCS-I-PPy NZs to mediate M1 macrophage activation and increase tumor infiltration highlights their potential in overcoming the limitations of current XPDT approaches and improving therapeutic outcomes in melanoma and other cancers.

Mitochondrion-targeted selenium nanoparticles stabilized by Sargassum fusiforme polysaccharides increase reactive oxygen species-mediated antitumour activity

Authors prepared a nanoselenium particle stabilized with Sargassum fusiforme polysaccharide (SFPS-Tw-SeNPs) and confirmed that it could effectively inhibit the proliferation of A549 lung cancer cells in vitro. The aim of this study was to investigate its anti-lung cancer effect in vitro and in vivo and its possible mechanism. In cell experiments, AO/EB staining revealed that SFPS-Tw-SeNPs could induce the apoptosis of A549 cells and produce red fluorescence by inserting into DNA through damaged cell membranes, increasing the production of reactive oxygen species (ROS). SFPS-Tw-SeNPs that is loaded with coumarin-6 entered the cells in a concentration-dependent and time-dependent manner, acting on the mitochondria, reducing the mitochondrial membrane potential, increasing the Bax/Bcl-2 ratio, and increasing the expression of Cleaved-Caspase 3, Cleaved-Caspase 9, Cleaved-PARP and Cytochrome C-induced apoptosis in cells. In addition, the SFPS-Tw-SeNPs blocked the PI3K/AKT signalling pathway, downregulated the expression of Cyclin-A and CDK2, upregulated the expression of P21, and arrested the cell in the G1 phase. In animal experiments, SFPS-Tw-SeNPs treatment significantly inhibited the growth of A549 tumour xenografts but did not significantly negatively affect the body of the animals. Overall, SFPS-Tw-SeNPs have the potential to be developed as a pharmaceutical drug to prevent and treat non-small cell lung cancer.

Lead toxicity mitigation effect of a Lactiplantibacillus plantarum-chondroitin sulfate complex revealed by microbiome and metabolomic analyses

Lead (Pb) is a highly toxic metal with no physiological function in humans, accumulates in the body through food intake, and causes gut microbiome disorders and other hazards. In the present study, we examined the efficacy of a combination of chondroitin sulfate and Lactiplantibacillus plantarum CCFM8661 (CCFM8661 + CS) on tissue Pb accumulation and pathological damage to the liver and kidneys, gut microbiota, and fecal metabolites in Pb-exposed mice. Oral administration of CCFM8661 + CS to Pb-exposed mice reduced Pb accumulation in the liver, kidney, and bone tissues (from 3.70, 14.11 and 121.20 mg g-1 wet tissue to 2.26, 8.72 and 65.57 mg g-1 wet tissue, respectively) and increased total antioxidant capacity, superoxide dismutase, and glutathione in the liver and kidneys. Additionally, gut microbiome analysis showed that CCFM8661 + CS intervention attenuated Pb-induced perturbation in gut microbiota, altering the abundance of bacteria such as Faecalibaculum, Ruminococcaceae UCG 014, Anaerostipes, and Enterorhabdus. Untargeted metabolomics analyses showed that CCFM8661 + CS significantly increased cinnamoylglycine, hippuric acid, and equol (to 31.24, 28.77 and 20.13 times the baseline, respectively) and decreased guanine and 4-coumaric acid (0.30 and 0.09 times the baseline, respectively) in the feces, affecting pathways such as purine and amino acid metabolism. Further analyses showed that promoting Pb excretion and restoring the Pb-impaired gut microbiome and its metabolism may be important contributors to CCFM8661 + CS alleviation of Pb toxicity.

Sulfate glycosaminoglycan from swim bladder exerts immunomodulatory potential on macrophages via toll-like receptor 4 mediated NF-κB signaling pathways

This study explored the immunomodulatory impact and potential mechanisms on macrophages RAW264.7 using a purified macromolecular sulfate glycosaminoglycan (SBSG) from the swim bladder, whose structure was similar to chondroitin sulfate A. The results showed that SBSG at 0.25-1 mg/mL increased the viability and phagocytosis of RAW264.7 cells. Meanwhile, SBSG promoted the secretion of tumor necrosis factor α (TNF-α), interleukin 10 (IL-10), and nitric oxide (NO), as well as the production of reactive oxygen species (ROS). According to the RT-PCR and Western blot data, SBSG activated TLR4-nuclear factor kappa B (NF-κB) signaling pathways, which decreased the relative mRNA and protein levels of Toll-like receptor 4 (TLR4), IκB kinase β (IKKβ), NF-κB p65, and p-NF-κB p65. The molecular docking and molecular dynamic simulation findings revealed that the main binding force between TLR4 and SBSG was conventional hydrogen bond interaction, resulting in more stable ligand receptor complexes. In summary, SBSG exhibits significant immunomodulatory potential, similar to chondroitin sulfate C. The underlying molecular mechanism involved the binding of SBSG through hydrogen bonding to TLR4 receptors, triggering the NF-κB signaling pathway to downregulate the expression of related genes and proteins. This, in turn, regulated the secretion of various cytokines that were mediated by macrophages to exert the immunity of the body.

Inhibiting ferroptosis in brain microvascular endothelial cells: A potential strategy to mitigate polystyrene nanoplastics‒induced blood‒brain barrier dysfunction

Polystyrene nanoplastics (PS-NPs), a group of ubiquitous pollutants, may injure the central nervous system through the blood‒brain barrier (BBB). However, whether exposure to PS-NPs contributes to BBB disruption and the underlying mechanisms are still unclear. In vivo, we found that PS-NPs (25 mg/kg BW) could significantly increase BBB permeability in mice and downregulate the distribution of the tight junction-associated protein zona occludens 1 (ZO-1) in brain microvascular endothelial cells (BMECs). Using an in vitro BBB model, exposure to PS-NPs significantly reduced the transendothelial electrical resistance and altered ZO-1 expression and distribution in a dose-dependent manner. RNA-seq analysis and functional investigations were used to investigate the molecular pathways involved in the response to PS-NPs. The results revealed that the ferroptosis and glutathione metabolism signaling pathways were related to the disruption of the BBB model caused by the PS-NPs. PS-NPs treatment promoted ferroptosis in bEnd.3 cells by inducing disordered glutathione metabolism in addition to Fe2+ and lipid peroxide accumulation, while suppressing ferroptosis with ferrostatin-1 (Fer-1) suppressed ferroptosis-related changes in bEnd.3 cells subjected to PS-NPs. Importantly, Fer-1 alleviated the decrease in ZO-1 expression in bEnd.3 cells and the exacerbation of BBB damage induced by PS-NPs. Collectively, our findings suggest that inhibiting ferroptosis in BMECs may serve as a potential therapeutic target against BBB disruption induced by PS-NPs exposure.

Thermally stabilized chondroitin sulfate-hemoglobin nanoparticles and their interaction with bioactive compounds

The preparation of nanoparticles (NPs) based on hemoglobin (Hb) with a fully biocompatible methodology is presented. The spontaneous formation of electrostatic complexes of Hb with chondroitin sulfate (CS) at pH 4 in the polysaccharide/protein mass ratio regime where charge neutrality is met leads to spherical nanostructures with monomodal hydrodynamic radii distribution in the range of 50-100 nm. The integrity of the electrostatic complexes is disturbed at pH 7 as the net electric charge of Hb is very low. Treating the NPs at mildly elevated temperature stabilizes them against the pH increase taking advantage of Hb's ability of unfolding and self-associating upon thermal treatment. The NPs surface charge is pH-tunable and changes from positive to strongly negative upon pH increase to 7 proving the presence of negative surface patches of Hb and CS segments in their exterior. The α-helix content of Hb does not change significantly by thermal treatment. The NPs are found to bind the bioactive compounds curcumin and β-carotene and are stable in solutions with high salt content. This investigation introduces a straightforward method to formulate Hb in NPs with possibilities in the nanodelivery of nutrients and drugs.

Chondroitin Sulfate/Dermatan Sulfate Hybrid Chains from Swim Bladder: Isolation, Structural Analysis, and Anticoagulant Activity

Glycosaminoglycans (GAGs) with unique structures from marine animals show intriguing pharmacological activities and negligible biological risks, providing more options for us to explore safer agents. The swim bladder is a tonic food and folk medicine, and its GAGs show good anticoagulant activity. In this study, two GAGs, CMG-1.0 and GMG-1.0, were extracted and isolated from the swim bladder of Cynoscion microlepidotus and Gadus morhua. The physicochemical properties, precise structural characteristics, and anticoagulant activities of these GAGs were determined for the first time. The analysis results of the CMG-1.0 and GMG-1.0 showed that they were chondroitin sulfate (CS)/dermatan sulfate (DS) hybrid chains with molecular weights of 109.3 kDa and 123.1 kDa, respectively. They were mainly composed of the repeating disaccharide unit of -{IdoA-α1,3-GalNAc4S-β1,4-}- (DS-A). The DS-B disaccharide unit of -{IdoA2S-α1,3-GalNAc4S-β1,4-}- also existed in both CMG-1.0 and GMG-1.0. CMG-1.0 had a higher proportion of CS-O disaccharide unit -{-GlcA-β1,3-GalNAc-β1,4-}- but a lower proportion of CS-E disaccharide unit -{-GlcA-β1,3-GalNAc4S6S-β1,4-}- than GMG-1.0. The disaccharide compositions of the GAGs varied in a species-specific manner. Anticoagulant activity assay revealed that both CMG-1.0 and GMG-1.0 had potent anticoagulant activity, which can significantly prolong activated partial thromboplastin time. GMG-1.0 also can prolong the thrombin time. CMG-1.0 showed no intrinsic tenase inhibition activity, while GMG-1.0 can obviously inhibit intrinsic tenase with EC50 of 58 nM. Their significantly different anticoagulant activities may be due to their different disaccharide structural units and proportions. These findings suggested that swim bladder by-products of fish processing of these two marine organisms may be used as a source of anticoagulants.