摘要:
Myeloid differentiation factor 88 (MyD88) and Toll or interleukin-1 receptor-domain-containing adaptor-inducing interferon-beta (IFN-beta) (TRIF) are two pivotal downstream adaptors of Toll-like receptors. Activation of MyD88 or TRIF signaling in cardiac immune pathology of severe inflammation negatively influences heart function. In the present study, severe septic cardiac injury was induced in C57BL/6 mice by cecum ligation and puncture (CLP). A total of 64 mice were divided randomly into the following four groups (n=16/group; 8 for observation of survival rate, 8 for heart sample analysis): Sham, CLP, anti-MyD88-CLP and anti-TRIF-CLP. Anti-MyD88 and anti-TRIF antibodies were administered to the respective mice through the tail veins 2 h before CLP. Measurements of cardiac function, including M-modes, velocity vector imaging and cardiac troponin I, were performed. Myocardial inflammatory cytokines were examined by reverse transcription-polymerase chain reaction (RT-PCR), myocardial neutrophil infiltration was measured by a myeloperoxidase activity assay, intracellular adhesion molecule and vascular cell adhesion molecule mRNA expression levels were investigated, and histopathological characteristics were evaluated. Levels of mRNA transcripts encoding genes for apoptosis production and MyD88, TRIF, nuclear factor-kappaB and IFN regulatory factor 3 were investigated by RT-PCR. Mice challenged with CLP demonstrated deleterious cardiac function, increased levels of interleukin-1beta (IL-1beta), IL-6beta, and tumor necrosis factor-alpha mRNA, increased neutrophil infiltration, and increased apoptosis. In contrast, mice in the anti-MyD88 CLP and anti-TRIF CLP groups retained cardiac function with reduced cytokine release, decreased neutrophil infiltration, and reduced apoptosis. In addition, there was no significant difference between the anti-MyD88 CLP and anti-TRIF CLP groups. Thus, the present study indicated that MyD88 and TRIF blockades serve notable and equivalent roles in protecting cardiac deterioration from severe sepsis by attenuating cytokine release, reducing neutrophil infiltration and alleviating apoptosis.
摘要:
This study was conducted to determine the effect of 200 ng mL−1 and 2000 ng mL−1 deoxynivalenol (DON) on apoptosis, barrier function, nutrient transporter gene expression, and free amino acid variation as well as on mitochondrial biogenesis and function-related gene expression in the intestinal porcine epithelial cell line J2 (IPEC-J2) for 6 h, 12 h, and 24 h. Exposure to 200 ng mL−1 DON inhibited the cell viability and promoted cell cycle progression from the G2/M phase to the S phase (P < 0.05). The data showed that the IPEC-J2 cell content of free amino acids, such as valine, methionine, leucine, and phenylalanine, was increased (P < 0.05) after treatment for 6 h; the aspartate, threonine, and lysine contents increased (P < 0.05) after treatment for 12 h; and the aspartate, serine, glycine, alanine, isoleucine, leucine, and lysine contents decreased (P < 0.05) after treatment for 24 h. The expression levels of barrier function genes, including zonula occludens 1 (ZO-1), occludin (OCLN), and claudin 1 (CLDN1), showed a significant reduction (P < 0.05). Moreover, the expression levels of differently regulated nutrient transporter genes, including B0,+ amino acid transporter (B0,+AT) and sodium-glucose transporter 1 (SGLT1) genes, showed a significant decrease (P < 0.05), while the Na+-dependent neutral amino acid transporter 2 (ASCT2) and glucose transporter type 2 (GLUT2) showed a significant increase (P < 0.01). The expression levels of cytokine genes, including IL-8, and IL-1β genes, showed a significant increase (P < 0.05). Furthermore, the expression levels of mitochondrial biogenesis and function-related genes, including mitochondrial transcription factor A (TFAM) and nuclear respiratory factor-1 (NRF), mitochondrial single-strand DNA-binding protein (mt SSB) and mitochondrial polymerase r (mt polr), NADH dehydrogenase subunit 4 (ND4) and cytochrome c oxidase (CcOX) IV, CcOX V and cytochrome c (Cyt c), mammalian silencing information regulator-2α (SIRT-1), glucokinase and citrate synthase (CS), showed a significant increase (P < 0.05). Taken together, the present study indicated that 200 and 2000 ng mL−1 DON could affect proliferation and cell cycle progression from the G2/M phase to the S phase and could mediate the expression levels of differently regulated barrier function, nutrient transport, and mitochondrial biogenesis and function-related genes.