Although many studies have shown that inflammatory response plays a crucial role in the various toxic effects of T-2 toxin, there are relatively few reports on the mechanism of this phenomenon. Meanwhile, accumulating evidence has shown that miR-155-5p is activated in the inflammatory response. As molecular pathways and mechanisms involved in T-2 toxin-induced inflammatory response are poorly elucidated, we assessed whether miR-155-5p is involved in the inflammation effects mediated by T-2 toxin. Treatment of RAW264.7 cells with T-2 toxin (14 nM and 12 h) resulted in inflammatory response and associated with alteration of the gene expression signature of miR-155-5p. Knockdown or overexpression of miR-155-5p both indicated that miR-155-5p positively regulated the expression of the inflammation factors. Moreover, bioinformatics prediction and luciferase assay indicated that atg3 and rheb are targets of miR-155-5p. However, atg3 and SOCS1 play positive roles in the inflammatory response regulated by miR-155-5p, while rheb plays a negative role. In addition, the in vivo study showed that single administration of T-2 toxin in mice enhances spleen immune response, which was accompanied by an overexpression of miR-155-5p. These findings indicate that miR-155-5p might have an important role associated with the inflammatory response induced by T-2 toxin. In conclusion, a dual character of miR-155-5p in inflammation response was revealed, which might exist in other reactions in which miR-155-5p is involved.

• MeSH
• cytokiny metabolismus   MeSH
• mediátory zánětu metabolismus   MeSH
• mikro RNA metabolismus   MeSH
• myši MeSH
• RAW 264.7 buňky MeSH
• signální transdukce MeSH
• T-2 toxin MeSH
• upregulace MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

T-2 toxin is a worldwide trichothecenetoxin and can cause various toxicities.T-2 toxin is involved in G1 phase arrest in several cell lines but molecular mechanism is still not clear. In present study, we used rat pituitary GH3 cells to investigate the mechanism involved in cell cycle arrest against T-2 toxin (40 nM) for 12, 24, 36 and 48 h as compared to control cells. GH3 cells showed a considerable increase in reactive oxygen species (ROS) as well as loss in mitochondrial membrane potential (△Ym) upon exposure to the T-2 toxin. Flow cytometry showed a significant time-dependent increase in percentage of apoptotic cells and gel electrophoresis showed the hallmark of apoptosis oligonucleosomal DNA fragmentation. Additionally, T-2 toxin-induced oxidative stress and DNA damage with a time-dependent significant increased expression of p53 favors the apoptotic process by the activation of caspase-3 in T-2 toxin treated cells. Cell cycle analysis by flow cytometry revealed a time-dependent increase ofG1 cell population along with the significant time-dependent up-regulation of mRNA and protein expression of p16 and p21 and significant down-regulation of cyclin D1, CDK4, and p-RB levels further verify the G1 phase arrest in GH3 cells. Morphology of GH3 cells by TEM clearly showed the damage and dysfunction to mitochondria and the cell nucleus. These findings for the first time demonstrate that T-2 toxin induces G1 phase cell cycle arrest by the involvement of p16/Rb pathway, along with ROS mediated oxidative stress and DNA damage with p53 and caspase cascade interaction, resulting in apoptosis in GH3 cells.

• MeSH
• buněčné linie MeSH
• buněčný cyklus účinky léků   fyziologie   MeSH
• geny p16 účinky léků   fyziologie   MeSH
• hypofýza účinky léků   metabolismus   ultrastruktura   MeSH
• krysa rodu rattus MeSH
• retinoblastomový protein biosyntéza   MeSH
• signální transdukce účinky léků   fyziologie   MeSH
• T-2 toxin toxicita   MeSH
• viabilita buněk účinky léků   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

T-2 toxin, a trichothecene mycotoxin, is a common contaminant in food and animal feed, and is also present in processed cereal products. The most common route of T-2 toxin exposure in humans is through dietary ingestion. The cytotoxic effects of T-2 toxin include modifications to feeding behavior, nervous disorders, cardiovascular alterations, immunosuppression, and hemostatic derangements. However, to date, effects on the central nervous system (CNS) have rarely been reported. In the present study, female Wistar rat were given a single dose of T-2 toxin at 2 mg/kg b.w. and were sacrificed at one, three, and seven days post-exposure. Histopathological analysis and transmission electron microscope (TEM) observations were used to investigate injury to the brain and pituitary gland. Damage to the brain and pituitary at the molecular level was detected by real time-polymerase chain reaction (RT-PCR), western blot, and immunohistochemical assays. Liquid chromatograph-mass spectrometer/mass spectrometer (LC-MS/MS) was used to investigate T-2 concentration in the brain. The results showed that pathological lesions were obvious in the brain at three days post-exposure; lesions in the pituitary were not observed until seven days post-exposure. Autophagy in the brain and apoptosis in the pituitary suggest that T-2 toxin may induce different acute reactions in different tissues. Importantly, low concentrations of T-2 toxin in the brain were observed in only one rat. Responsible for the above mentioned, we hypothesize that brain damage caused by this toxin may be due to the ability of the toxin to directly cross the blood-brain barrier (BBB). Therefore, given its widespread pollution in food, we should pay more attention to the neurotoxic effects of the T-2 toxin, which may have widespread implications for human health.

• MeSH
• apoptóza účinky léků   MeSH
• autofagie účinky léků   MeSH
• časové faktory MeSH
• chování zvířat účinky léků   MeSH
• chromatografie kapalinová MeSH
• hematoencefalická bariéra metabolismus   MeSH
• hodnocení rizik MeSH
• hypofýza účinky léků   metabolismus   ultrastruktura   MeSH
• imunohistochemie MeSH
• kapilární permeabilita MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• mozek účinky léků   metabolismus   ultrastruktura   MeSH
• neurotoxické syndromy etiologie   metabolismus   patologie   psychologie   MeSH
• potkani Wistar MeSH
• regulace genové exprese MeSH
• T-2 toxin metabolismus   toxicita   MeSH
• tandemová hmotnostní spektrometrie MeSH
• transmisní elektronová mikroskopie MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Chronic exposure to low dose of T-2 toxin causes growth retardation and reduced body weight, resulting in economic losses. Excessive inflammatory cytokines and GH deficiency are important mechanisms that contribute to growth inhibition induced by T-2 toxin. However, the regulation of the inflammatory cytokines expecially IL-6, IL-1β, and TNF-α induced by T-2 toxin still remained unclear. The new transcription factor AKNA, belonging to AT-hook protein family, is closely associated with inflammation. However, it was unclear how AKNA regulate the expression of inflammatory cytokines, and there was no report on the role of AKNA in T-2 toxin mediated toxicity. Here, we investigated the role of AKNA in T-2 toxin-mediated inflammatory response and GH deficiency and the signal transduction pathway of AKNA. We showed that AKNA regulated by PKA/CREB and NF-κB pathway is a novel downstream molecular target in T-2 toxin-mediated inflammation and GH deficiency. T-2 toxin activates the PKA/CREB and NF-κB/p65 pathways, thereby promoting the direct binding of phospho-CREB and phospho-p65 to the AKNA promoter, thus inhibiting AKNA expression. GH and inflammatory cytokines (TNF-α, IL-1β, and IL-6) expression were significantly downregulated after AKNA silencing. Furthermore, the expression of differential genes induced by T-2 toxin in the rat pituitary was further confirmed by acute toxicity tests in rats, which was consistent with the results in GH3 cells. By histopathological analysis, we confirmed the pituitary might be a novel direct target organ of T-2 toxin. These findings provided new insights into the significant role of AKNA in T-2 toxin-induced inflammatory response and growth inhibition.

• MeSH
• buněčné linie MeSH
• DNA vazebné proteiny genetika   metabolismus   MeSH
• down regulace MeSH
• fosforylace MeSH
• interleukin-1beta genetika   metabolismus   MeSH
• interleukin-6 genetika   metabolismus   MeSH
• jaderné proteiny genetika   metabolismus   MeSH
• krysa rodu rattus MeSH
• NF-kappa B metabolismus   MeSH
• promotorové oblasti (genetika) MeSH
• protein vázající element responzivní pro cyklický AMP metabolismus   MeSH
• proteinkinasy závislé na cyklickém AMP metabolismus   MeSH
• T-2 toxin toxicita   MeSH
• TNF-alfa genetika   metabolismus   MeSH
• transkripční faktory genetika   metabolismus   MeSH
• umlčování genů MeSH
• zánět chemicky indukované   genetika   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

T-2 toxin, a major compound of trichothecenes, induces cell apoptosis and growth hormone (GH) deficiency and causes considerable growth retardation in animals and human cells. However, the mechanism underlying its growth suppression still remains unclear. Recent studies have suggested that ROS induced cell apoptosis and animal feed intake reduction, but there are limited reports on the role of RNS in T-2 toxin-mediated mitochondrial damage, cell apoptosis and growth retardation. Herein, T-2 toxin-induced GH3 cell damage and apoptosis were tested by MTT assay, LDH leakage and flow cytometry, respectively. Intracellular NO and antioxidant enzyme activity, ΔΨm, morphometric changes of mitochondria, the caspase pathway, and inflammatory factors were investigated. Free radical scavengers NAC, SOD and NO scavenger haemoglobin were used to explore the role of oxidative stress and the relationship between NO production and caspase pathway. The results clearly revealed that T-2 toxin caused significant increases in NO generation, cell apoptosis, GH deficiency, increased iNOS activity, upregulation of inflammatory factors and caspase pathway, decreases in ΔΨm and morphosis damage. These data suggest that mitochondria are a primary target of T-2 toxin-induced NO, and NO is a key mediator of T-2 toxin-induced cell apoptosis and GH deficiency via the mitochondria-dependent pathway in cells.

• MeSH
• adenohypofýza cytologie   MeSH
• apoptóza účinky léků   MeSH
• kaspasy metabolismus   MeSH
• krysa rodu rattus MeSH
• membránový potenciál mitochondrií účinky léků   MeSH
• mitochondrie účinky léků   metabolismus   MeSH
• oxid dusnatý metabolismus   MeSH
• oxidační stres účinky léků   MeSH
• růstový hormon nedostatek   MeSH
• signální transdukce účinky léků   MeSH
• somatotropní buňky účinky léků   metabolismus   patologie   MeSH
• synthasa oxidu dusnatého, typ II metabolismus   MeSH
• T-2 toxin toxicita   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH