Huidan Deng

The Fusarium toxin zearalenone and deoxynivalenol affect murine splenic antioxidant functions, interferon levels, and T-cell subsets.

This study aimed to evaluate the effects of the Fusarium toxin zearalenone (ZEA) and deoxynivalenol (DON) on splenic antioxidant functions, IFN levels, and T-cell subsets in mice. Herein, 360 mice were assigned to nine groups for a 12-day study. Mice were administered an intraperitoneal injection for 4 consecutive days with different concentrations of ZEA alone, DON alone, or ZEA+DON. Spleen and blood samples were collected on days 0, 3, 5, 8, and 12. Mice in each of the experimental groups showed dysreglated splenic antioxidant functions, IFN levels, and T-cell subset frequencies, suggesting that the immune system had been affected. The ZEA+DON-treated groups, especially the group that received a higher concentration of ZEA+DON (Group D2Z2), showed more obvious effects on the dysregulation of splenic antioxidant functions, IFN levels, and T-cell subsets. This finding suggested that DON and ZEA exerted synergistic effects.

Nickel chloride (NiCl 2 )-caused inflammatory responses via activation of NF-κB pathway and reduction of anti-inflammatory mediator expression in the kidney

Nickel (Ni) or Ni compounds target a number of organs and produce multiple toxic effects. Kidney is the major organ for Ni accumulation and excretion. There are no investigations on the Ni- or Ni compounds-induced renal inflammatory responses in human beings and animals at present. Therefore, we determined NiCl2-caused alteration of inflammatory mediators, and functional damage in the broilers kidney by the methods of biochemistry, immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR). Dietary NiCl2 in excess of 300 mg/kg caused the renal inflammatory responses that characterized by increasing mRNA expression levels of the pro-inflammatory mediators including tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8) and interleukin-18 (IL-18) via the activation of nucleic factor κB (NF-κB), and decreasing mRNA expression levels of the anti-inflammatory mediators including interleukin-2 (IL-2), interleukin-4 (IL-4) and interleukin-13 (IL-13). Concurrently, NiCl2 caused degeneration, necrosis and apoptosis of the tubular cells, which was consistent with the alteration of renal function parameters including elevated alkaline phosphatase (AKP) activity, and reduced activities of sodium-potassium adenosine triphosphatase (Na+/K+-ATPase), calcium adenosine triphosphatase (Ca2+-ATPase), lactic dehydrogenase (LDH), succinate dehydrogenase (SDH) and acid phosphatase (ACP) in the kidney. The above-mentioned results present that the activation of NF-κB pathway and reduction of anti-inflammatory mediator expression are main mechanisms of NiCl2-caused renal inflammatory responses and that the renal function is decreased or impaired after NiCl2-treated.

Sodium fluoride (NaF) induces the splenic apoptosis via endoplasmic reticulum (ER) stress pathway in vivo and in vitro.

At present, there are no reports on the relationship between fluoride-induced apoptosis and endoplasmic reticulum (ER) stress (ER stress) in the spleen of human and animals in vivo and in vitro. Therefore, the aim of this study was to define sodium fluoride (NaF)-induced apoptosis mediated by ER stress in the spleen of mice in vivo and in vitro. Apoptosis and expression levels of the ER stress-related proteins were detected by flow cytometry and western blot, respectively. The results showed that NaF treatment increased lymphocytes apoptosis, which was consistent with NaF-caused ER Stress. NaF-caused ER stress was characterized by up-regulating protein expression levels of glucose-regulated protein 78 (BiP) and glucose-regulated protein 94 (GRP94), and by activating unfolded protein response (UPR). The signaling pathway of ER stress-associated apoptosis was activated by up-regulating protein expression levels of cleaved cysteine aspartate specific protease-12 (cleaved caspase-12), growth arrest and DNA damage-inducible gene 153 (Gadd153/CHOP) and phosphorylation of JUN N-terminal kinase (p-JNK). Additionally, our in vitro study found that apoptotic rate was decreased with remarkable down-regulation of the cleaved caspase-12, CHOP, p-JNK after ER stress was inhibited by 4-Phenylbutyric acid (4-PBA) treatment. In conclusion, NaF-induced apoptosis may mediated by ER stress in the spleen.

Deoxynivalenol-induced cytokines and related genes in concanavalin A-stimulated primary chicken splenic lymphocytes

Deoxynivalenol (DON) immunotoxicity and its induction of cytokines and related genes in the splenic lymphocytes of chickens have not been completely elucidated. In the present study, we aimed to evaluate the effects of 48 h of different DON treatments (0 μg/mL, 0.2 μg/mL, 0.8 μg/mL, 3.2 μg/mL, 12.5 μg/mL, and 50 μg/mL) on the secretion and the mRNA expressions of some cytokine genes, such as interleukin-1beta (IL-1β), IL-1RI, IL-2, IL-4, IL-6, IL-10, IL-12β, and IFN-γ in chicken splenic lymphocytes. The concentrations of IL-1RI, IL-6, IL-10, and IFN-γ were increased with the DON concentrations increasing (P<0.05 or P<0.01). However, the concentrations of IL-1β, IL-2, IL-4, and IL-12β were decreased with the DON concentrations increasing (P<0.05 or P<0.01). Except IL-1β, the mRNA expressions of the other cytokines were up-regulated by DON. The highest mRNA expressions values of IL-1RI, IL-4, IL-10, IL-12β, and IFN-γ were at 50 μg/mL DON treatment groups (P<0.05 or P<0.01), while the highest mRNA expressions values of IL-2 and IL-6 were at 12.5 μg/mL DON treatment groups (P<0.05 or P<0.01). Our data revealed that the potent effects of DON in affecting the secretion and the mRNA expression of the related cytokines in chicken splenic lymphocytes in vitro.

Inflammatory responses and inflammation-associated diseases in organs

Inflammation is a biological response of the immune system that can be triggered by a variety of factors, including pathogens, damaged cells and toxic compounds. These factors may induce acute and/or chronic inflammatory responses in the heart, pancreas, liver, kidney, lung, brain, intestinal tract and reproductive system, potentially leading to tissue damage or disease. Both infectious and non-infectious agents and cell damage activate inflammatory cells and trigger inflammatory signaling pathways, most commonly the NF-κB, MAPK, and JAK-STAT pathways. Here, we review inflammatory responses within organs, focusing on the etiology of inflammation, inflammatory response mechanisms, resolution of inflammation, and organ-specific inflammatory responses.

Suppressive effects of sodium fluoride on cultured splenic lymphocyte proliferation in mice

Fluoride-induced immunotoxicity has been documented in vivo, but limited reports have focused on the effects of fluoride on lymphocytes in vitro. Therefore, we have examined the suppressive effects of sodium fluoride on cultured splenic lymphocytes in mice. CD3+ T lymphocytes, CD19+ B lymphocytes, cytokines, and cell-cycle markers were analyzed through the use of a cell-counting kit, western blot, and flow cytometery. Splenic lymphocytes were isolated from 3-week-old male ICR mice and exposed to sodium fluoride (0, 100, 500, and 1000 μmol/L) for 24 h. The percentages of CD3+, CD3+CD4+, CD3+CD8+ T lymphocytes and CD19+ B lymphocytes were decreased (P<0.05 or P<0.01) in the sodium fluoride-exposed cells. This finding was correlated with the alterations in expression levels of cytokine proteins and with evidence of cell-cycle arrest. Thus, protein expression levels of IL-2, TNF-α, IFN-γ, TGF-β were decreased (P<0.05 or P<0.01), and IL-10 protein expression levels were increased (P<0.05 or P<0.01). The percentage of lymphocyte in G1 phase was significantly increased (P<0.05 or P<0.01), while expression levels of cyclin E/D and CDK2/4 were markedly decreased (P<0.05 or P<0.01). These findings demonstrate that sodium fluoride exposure suppresses splenic lymphocyte proliferation, which is represented by reducing populations and activation of splenic T and B lymphocytes. Alterations of cytokine protein expression and cell cycle arrest are the molecular basis of the sodium fluoride-suppressed splenic lymphocyte proliferation, while reduction of T lymphocytes and B lymphocytes is the explanation of sodium fluoride-decreased splenic immune function in vitro.

Sodium fluoride causes oxidative stress and apoptosis in the mouse liver

The current study was conducted to investigate the effect of sodium fluoride (NaF) on the oxidative stress and apoptosis as well as their relationship in the mouse liver by using methods of flow cytometry, quantitative real-time polymerase chain reaction (qRT-PCR), western blot, biochemistry and experimental pathology. 240 four-week-old ICR mice were randomly divided into 4 groups and exposed to different concentration of NaF (0 mg/kg, 12 mg/kg, 24 mg/kg and 48 mg/kg) for a period of 42 days. The results showed that NaF caused oxidative stress and apoptosis. NaF-caused oxidative stress was accompanied by increasing reactive oxygen species (ROS) and malondialdehyde (MDA) levels, and decreasing mRNA expression levels and activities of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GSH-PX) and glutathione-s-transferase (GST). NaF induced apoptosis via tumor necrosis factor recpter-1 (TNF-R1) signaling pathway, which was characterized by significantly increasing mRNA and protein expression levels of TNF-R1, Fas associated death domain (FADD), TNFR-associated death domain (TRADD), cysteine aspartate specific protease-8 (caspase-8) and cysteine aspartate specific protease-3 (caspase-3) in dose- and time-dependent manner. Oxidative stress is involved in the process of apoptotic occurrence, and can be triggered by promoting ROS production and reducing antioxidant function. NaF-caused oxidative stress and apoptosis finally impaired hepatic function, which was strongly supported by the histopathological lesions and increased serum alanine amino transferase (ALT), aspartic acid transferase (AST), alkaline phosphatase (AKP) activities and TBIL contents.

Effect of the Fusarium toxins, zearalenone and deoxynivalenol, on the mouse brain

The aim of this study was to find effects of Fusarium toxins on brain injury in mice. We evaluated the individual and combined effect of the Fusarium toxins zearalenone and deoxynivalenol on the mouse brain. We examined brain weight, protein, antioxidant indicators, and apoptosis. After 3 and 5days of treatment, increased levels of nitric oxide, total nitric oxide synthase, hydroxyl radical scavenging, and malondialdehyde were observed in the treatment groups. This was accompanied by reduced levels of brain protein, superoxide dismutase (apart from the low-dose zearalenone groups), glutathione, glutathione peroxidase activity, and percentage of apoptotic cells. By day 12, most of these indicators had returned to control group levels. The effects of zearalenone and deoxynivalenol were dose-dependent, and were synergistic in combination. Our results suggest that brain function is affected by zearalenone and deoxynivalenol.

Combined effects of deoxynivalenol and zearalenone on oxidative injury and apoptosis in porcine splenic lymphocytes in vitro

Deoxynivalenol (DON) and zearalenone (ZEA) are the two most common mycotoxins in animal feed. In this study, we examined oxidative injury and apoptosis of porcine splenic lymphocytes induced by DON or ZEA and their combination in vitro. Based on IC50 values, porcine splenic lymphocytes were treated with 0.06, 0.3, 1.5, and 7.5μg/mL DON, 0.08, 0.4, 2, and 10μg/mL ZEA, or both DON and ZEA at 0.06 and 0.08μg/mL, 0.3 and 0.4μg/mL, and 1.5 and 2μg/mL, respectively. After 48h of DON and/or ZEA exposure, the cells were analyzed for antioxidant functions, apoptosis, and mRNA and protein expression of apoptosis-related genes p53, Bcl-2, Bax, caspase-3, and caspase-8 to determine their apoptosis and oxidative damage effects and mechanisms. The results showed that, compared with the control group, SOD, CAT, GPx, GSH, and Bcl-2 mRNA and protein expression levels were significantly reduced in exposed groups (P<0.05 or P<0.01). Furthermore, MDA contents, apoptosis rates, and p53, Bax, caspase-3 and caspase-8 protein and mRNA expression levels were increased significantly (P<0.01). The effects of DON and ZEA were dose dependent and synergistic in combination. These data suggest that DON and ZEA induce oxidative damage and apoptosis of porcine splenic lymphocytes.

Sodium fluoride induces apoptosis in cultured splenic lymphocytes from mice

Though fluorine has been shown to induce apoptosis in immune organs in vivo, there has no report on fluoride-induced apoptosis in the cultured lymphocytes. Therefore, this study was conducted with objective of investigating apoptosis induced by sodium fluoride (NaF) and the mechanism behind that in the cultured splenic lymphocytes by flow cytometry, western blot and Hoechst 33258 staining. The splenic lymphocytes were isolated from 3 weeks old male ICR mice and exposed to NaF (0, 100, 200, and 400 μmol/L) in vitro for 24 and 48 h. When compared to control group, flow cytometry assay and Hoechst 33258 staining showed that NaF induced lymphocytes apoptosis, which was promoted by decrease of mitochondria transmembrane potential, up-regulation of Bax, Bak, Fas, FasL, caspase 9, caspase 8, caspase 7, caspase 6 and caspase 3 protein expression (P < 0.05 or P <0.01), and down-regulation of Bcl-2 and Bcl-xL protein expression (P <0.05 or P <0.01). The above-mentioned data suggested that NaF-induced apoptosis in splenic lymphocytes could be mediated by mitochondrial and death receptor pathways.