Impact of Eimeria tenella experimental Infection on intestinal and splenic reaction of broiler chickens

This work assesses the cell-mediated immune reaction IL-6, TNF-α, and IFN-γ of experimentally challenged broiler chicken with Eimeria tenella (E. tenella). Therefore, ninety, 2-weeks-old healthy broiler chicks were allocated as eighty chicks infected orally with 2.5 × 104 E. tenella sporulated oocysts, and the other ten birds were kept as control negative birds. Post-challenge, mortality rate, symptoms, oocysts shedding, and lesion score were evaluated. Tissue samples (cecum and spleen) were collected at 0, 4, 8, and 12 days post-infection (dpi). Ten chickens were ethically slaughtered at 0, 4, 8, and 12 days post-infection, as well as two birds from the negative control group; parts from cecal and spleen samples were kept in cryopreservation containers, and other parts were preserved in formaline 10% for further investigation. The evaluated genes (IL-6, TNF-α, and IFN-γ) were normal at 0 days and upregulated at 4 and 8 days, which reached maximum upregulation at eight dpi. The histopathological examination of the ceca and spleen were evaluated before and after challenge. It could be concluded that E. tenella revealed direct severe macroscopic and microscopic changes in cecal tissues and indirectly induced alteration in splenic tissues, resulting in upregulation of different cell mediated immune response in cecum and spleen in relation to the experimental period.

The Immunoprotective Effect of ROP27 Protein of Eimeria tenella

Eimeria tenella rhoptry protein has the properties of a protective antigen. EtROP27 is a pathogenic gene that is detected via a transcriptome, but its expression pattern, immunogenicity, and potency are unknown. Therefore, a gene segment of EtROP27 was amplified and transplanted into the pET28a prokaryotic vector for the expression of the recombinant protein, and it subsequently purified for the generation of a polyclonal antibody. Then, RT-PCR and Western blotting were performed to understand the expression pattern of EtROP27. Subsequently, animal experiments were conducted to evaluate the immunoprotective effect of the recombinant protein with different immunizing doses (50, 100, and 150 μg). The results showed that the expression of EtROP27 gradually increased with the prolongation of infection time, reaching the highest level at 96 h and then decreasing. Additionally, EtROP27 is a natural antigen of coccidia that can stimulate the body to produce high levels of IgY. As with recombinant protein vaccines, the results of immune protection evaluation tests showed that the average weight gain rates of the immune challenge groups were significantly higher than that of the challenged control group, and their average lesion scores were significantly lower than that of the challenged control group. Furthermore, the oocyst excretion decreased by 81.25%, 86.21%, and 80.01%, and the anticoccidial index was 159.45, 171.47, and 166.75, respectively, for these groups. EtROP27 is a promising antigen gene candidate for the development of a coccidiosis vaccine.

Investigation of Aggregation and Disaggregation of Self-Assembling Nano-Sized Clusters Consisting of Individual Iron Oxide Nanoparticles upon Interaction with HEWL Protein Molecules

In this paper, iron oxide nanoparticles coated with trisodium citrate were obtained. Nanoparticles self-assembling stable clusters were ~10 and 50-80 nm in size, consisting of NPs 3 nm in size. The stability was controlled by using multi-angle dynamic light scattering and the zeta potential, which was -32 ± 2 mV. Clusters from TSC-IONPs can be destroyed when interacting with a hen egg-white lysozyme. After the destruction of the nanoparticles and proteins, aggregates are formed quickly, within 5-10 min. Their sizes depend on the concentration of the lysozyme and nanoparticles and can reach micron sizes. It is shown that individual protein molecules can be isolated from the formed aggregates under shaking. Such aggregation was observed by several methods: multi-angle dynamic light scattering, optical absorption, fluorescence spectroscopy, TEM, and optical microscopy. It is important to note that the concentrations of NPs at which the protein aggregation took place were also toxic to cells. There was a sharp decrease in the survival of mouse fibroblasts (Fe concentration ~75-100 μM), while the ratio of apoptotic to all dead cells increased. Additionally, at low concentrations of NPs, an increase in cell size was observed.

Apoptosis-Associated Gene Expression Profiling Is One New Prognosis Risk Predictor of Human Rectal Cancer

Background. Prior research has revealed the predictive significance of a series of genetic markers in the prognosis of rectal cancer (RC), but the roles of apoptosis-associated genes in RC are rarely studied. Methods. The RNA-seq data as well as clinical data about patients with rectum adenocarcinoma (READ) were downloaded from The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) project. Additionally, 87 apoptosis-associated genes were downloaded and acquired from Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Comprehensive bioinformatics analysis was carried out for deep exploration of the expression and prognostic significance of these genes. Least absolute shrinkage and selection operator (LASSO) and multivariate Cox regression analysis was performed for the establishment of a risk scoring equation for the prognosis model and construction of a survival prognosis model. ROC curves were drawn for evaluating the accuracy of the model. A real-time quantitative PCR assay was conducted for quantification of apoptosis-associated proteins related to prognosis. Results. Eight genes were identified as hub genes associated with the prognosis of PFS. A risk model of prognosis prediction based on four gene signatures (CYCS, IKBKB, NFKB1, and TRADD) was constructed. According to further analysis of this model, the high-risk group experienced worse overall survival than the other. The prognosis model demonstrated a favorable predictive ability, with areas under the receiver operating characteristic curves (AUC) of 0.720, 0.641, and 0.677 in forecasting the 1-, 2-, and 3-year prognosis, respectively. In addition, CYCS and NFKB1 presented low expression, while IKBKB and TRADD presented high expression in TCGA and clinical tumor samples. Conclusions. A four-gene signature risk model for prognosis forecasting of RC has been constructed, which possesses favorable predictive ability, which offers ideas and breakthrough points to the apoptosis-associated development of RC.

The role of Ca2+ in the injury of host cells during the schizogenic stage of E. tenella

Cecal epithelial cell damage is a key factor in host injure during the development of E. tenella. The intracellular free Ca²⁺ of the host cell is closely related to the invasion, development and proliferation of intracellular parasites, and cell damage. To determine the relationship between Ca²⁺ and host cell damage in the schizogenic stage of E. tenella, we established a chick embryo cecal epithelial cells model of E. tenella infection. Fluorescence staining, flow cytometry, transmission electron microscopy, inhibition and blocking experiments were used to detect the damage effect and mechanism of host cells during the schizogenic stage of E. tenella. The results showed that the host cells cytoskeletal remodeling, cell and organelle structure was destroyed, and apoptosis and necrosis were increased during the schizont stage of E. tenella. Furthermore, the above-mentioned effects of the schizogenic stage of E. tenella on cells can be alleviated by reducing the intracellular Ca²⁺ concentration in the host cells. These observations indicate that the effect of host cell injury was closely related to Ca²⁺ during schizont stage of E. tenella.

The interaction between free Ca2+ in host cells and invasion of E. tenella

Eimeria tenella is the most pathogenic and common coccidia that causes chicken coccidiosis. The intracellular free Ca²⁺ of the host cell is closely related to the invasion, development, and proliferation of intracellular parasites. To determine the dynamic changes of intracellular free Ca²⁺ and its function in the process of E. tenella invading host cells, we established a chick embryo cecal epithelial cells model of E. tenella infection. Chick embryo cecal epithelial cells were treated with different Ca²⁺ signal inhibitor, respectively, and then infected with E. tenella. The results showed that extracellular Ca²⁺, Ca²⁺ channels on the cell membrane, IP3R ion channels on the endoplasmic reticulum membrane, and RyR ion channels regulated the free Ca²⁺ in cecal epithelial cells. Through fluorescence labeling and invasion rate detection, we found that the intracellular Ca²⁺ did not change significantly during the invasion of E. tenella, but its stability was critical to the invasion of parasites.

Roles of TNF receptor-associated and Fas-associated death domain proteins in the apoptosis of Eimeria tenella host cells

The present study aimed to investigate the effects of death receptor adapter proteins, namely, TNF receptor-associated death domain (TRADD) and Fas-associated death domain (FADD) proteins, on Eimeria tenella-induced host cell apoptosis. Gene silencing, culture technique for primary chick embryo cecal epithelial cells, enzyme-linked immunosorbent assay, Hoechst-Annexin V/PI apoptosis staining, fluorescence quantitative PCR, and flow cytometry were used to detect the E. tenella host cell apoptotic rate, RIP1 and FADD protein expression levels, and caspase-8 activity of the TRADD siRNA-treated and FADD siRNA-treated groups. Results showed that the apoptotic rate in the TRADD siRNA group was significantly higher than that in the NC siRNA group at 4 h post-infection with E. tenella (P < 0.05). The RIP1 protein expression level in the TRADD siRNA group was significantly lower than that in the NC siRNA group at 4-24 h (P < 0.05). The FADD expression and apoptotic rates in the TRADD siRNA group were significantly lower than those in the NC siRNA group at 24-120 h (P < 0.05). The caspase-8 activity and apoptotic rates in the FADD siRNA group were significantly lower than those in the NC siRNA group (P < 0.05) at 24-120 h. These findings indicated that E. tenella inhibited the host cell apoptosis through the TRADD-RIP1 pathway at the early developmental stage and promoted host cell apoptosis via the TRADD-FADD-caspase-8 apoptotic pathway at the middle and late developmental stages.

Effects of the PI3K/Akt signaling pathway on the apoptosis of early host cells infected with Eimeria tenella

This study investigated the role of PI3K/Akt signaling pathway on host cell apoptosis in the early infection of Eimeria tenella. Chicken cecal epithelial cells were treated with apoptosis-inducer Actinomycin D (Act D) or PI3K/Akt signaling pathway inhibitor LY294002 and then infected with E. tenella. Results demonstrated that the E. tenella-infected group had less apoptosis 4-8 h after the infection and more apoptosis 12-20 h after the infection than the control group. At 4-20 h after the infection, the apoptotic/necrotic rate and the Caspase-3 activity in the Act D + E. tenella group were lower (P < 0.01) than those in the Act D-treated group. The p-Akt and NF-κB contents in the E. tenella-infected group were higher (P < 0.01) than those in the control group 4-12 h after the infection. However, the bad content and the Caspase-9/3 activity were lower (P < 0.05) in the E. tenella-infected group than in the control group. Compared with the E. tenella-infected group, the LY294002 + E. tenella group showed decreased p-Akt content and increased apoptotic/necrotic rate, bad content, NF-κB expression, membrane permeability transition pore (MPTP) openness, and Caspase-9/3 activity. Thus, the early development of E. tenella could inhibit host cell apoptosis by downregulating the Caspase-3 activity. Upregulating this activity promoted apoptosis. In addition, activating the PI3K/Akt signaling pathway inhibited the apoptosis of E. tenella host cells in the early infection by reducing the expression of the bad content, limiting the MPTP opening, and decreasing the Caspase-9 and Caspase-3 activities.

SNHG9, delivered by adipocyte-derived exosomes, alleviates inflammation and apoptosis of endothelial cells through suppressing TRADD expression

Exosomes are membrane-derived vesicles and play a critical role in cell signaling by transferring RNAs and proteins to target cells through fusion with the cell membrane. Long non-coding RNA-small nucleolar RNA host gene 9 (lncRNA-SNHG9) was proven to be an important element in lncRNA-mRNA interaction networks during adipocyte differentiation, suggesting its potential involvement in the development of obesity, an important risk factor of cardiovascular and cerebrovascular endothelial dysfunction. However, the role of lncRNA-SNHG9 within the exosome in endothelial dysfunction of obese patients is largely unknown. In this study, we proved that adipocytes-derived exosomal SNHG9 were downregulated in obese persons and further decreased in obese individuals with endothelial dysfunction. Functional experimentations demonstrated that adipocytes-derived exosomal SNHG9 alleviated inflammation and apoptosis in endothelial cells. Bioinformatic analysis revealed that there was a potential interaction between SNHG9 and the TNF receptor type 1-associated death domain protein (TRADD) mRNA. Then, RNA-binding protein immunoprecipitation assay based on Ago2 antibody and ribonuclease protection assay demonstrated that exosomal SNHG9 directly bound to a specific region in TRADD mRNA sequence and formed an RNA dimeric inducible silencing complex. Moreover, knockdown of TRADD markedly inhibited inflammation and apoptosis in human umbilical vein endothelial cells (HUVECs), whereas overexpression of TRADD dramatically neutralized the protective effect of exosomal SNHG9 on epithelial dysfunction. Therefore, SNHG9 could prevent endothelial dysfunction in obese patients by suppressing inflammation and apoptosis, indicating that SNHG9 may be a potential therapeutic target for obese patients with endothelial dysfunction.

Comparison of the host cells apoptosis induced by precocious strains and virulent strains of Eimeria tenella

The present study aims to investigate the similarities and differences between the host cells apoptosis induced by virulent line of Eimeria tenella (Tsx) and precocious line (PTsx), which can provide a theoretical basis for the study of drugs and vaccines against coccidiosis. HE staining, Hoechst 33342/AnnexinV-FITC/PI composite staining, and ELISA were used to detect the infection rate, apoptosis rate, and Caspase-3 enzyme activity of host cells infected by PTsx or Tsx, respectively. The apoptotic rates and Caspase-3 absorbance of the inoculation groups were lower (P < 0.05 or P < 0.01) than those of the control group at 4 h, whereas the apoptotic rates and Caspase-3 absorbance of the inoculation groups were higher (P < 0.05 or P < 0.01) than those of the control groups at 24 to 120 h. At the same inoculation dose, there was no significant difference in the infection rate, apoptosis rate or Caspase-3 absorbance between Tsx groups and PTsx groups after E. tenella inoculation for 4 to 72 h (P > 0.05). However, these indicators of PTsx groups were lower (P < 0.01) than those of the same dose inoculated Tsx groups at 120 h. The apoptosis rates of cecal and glandular epithelial cells in the inoculated groups were higher (P < 0.01) than those in the control group after inoculated E. tenella 5 D in vivo, and the apoptosis rates of cecal and glandular epithelial cells in PTsx group was lower (P < 0.01) than that in the same dose inoculated Tsx group. These observations indicate that both Tsx and PTsx inhibit host cell apoptosis in the early development of E. tenella, induce host cell apoptosis in the middle and late stages, and the apoptosis-inducing effect on host cells increases with increasing dose. However, when the same dose of oocysts was inoculated, the amount of apoptosis induced by PTsx in late development was less than Tsx.

Death domain of p75 neurotrophin receptor: a structural perspective on an intracellular signalling hub

The death domain (DD) is a globular protein motif with a signature feature of an all-helical Greek-key motif. It is a primary mediator of a variety of biological activities, including apoptosis, cell survival and cytoskeletal changes, which are related to many neurodegenerative diseases, neurotrauma, and cancers. DDs exist in a wide range of signalling proteins including p75 neurotrophin receptor (p75^NTR ), a member of the tumour necrosis factor receptor superfamily. The specific signalling mediated by p75^NTR in a given cell depends on the type of ligand engaging the extracellular domain and the recruitment of cytosolic interactors to the intracellular domain, especially the DD, of the receptor. In solution, the p75^NTR -DDs mainly form a symmetric non-covalent homodimer. In response to extracellular signals, conformational changes in the p75^NTR extracellular domain (ECD) propagate to the p75^NTR -DD through the disulfide-bonded transmembrane domain (TMD) and destabilize the p75^NTR -DD homodimer, leading to protomer separation and exposure of binding sites on the DD surface. In this review, we focus on recent advances in the study of the structural mechanism of p75^NTR -DD signalling through recruitment of diverse intracellular interactors for the regulation and control of diverse functional outputs.

Vitamin C and sodium bicarbonate enhance the antioxidant ability of H9C2 cells and induce HSPs to relieve heat stress

Heat stress is exacerbated by global warming and affects human and animal health, leading to heart damage caused by imbalances in reactive oxygen species (ROS) and the antioxidant system, acid-base chemistry, electrolytes and respiratory alkalosis. Vitamin C scavenges excess ROS, and sodium bicarbonate maintains acid-base and electrolyte balance, and alleviates respiratory alkalosis. Herein, we explored the ability of vitamin C alone and in combination with equimolar sodium bicarbonate (Vitamin C-Na) to stimulate endogenous antioxidants and heat shock proteins (HSPs) to relieve heat stress in H9C2 cells. Control, vitamin C (20 μg/ml vitamin C for 16 h) and vitamin C-Na (20 μg/ml vitamin C-Na for 16 h) groups were heat-stressed for 1, 3 or 5 h. Granular and vacuolar degeneration, karyopyknosis and damage to nuclei and mitochondria were clearly reduced in treatment groups, as were apoptosis, lactate dehydrogenase activity and ROS and malondialdehyde levels, while superoxide dismutase activity was increased. Additionally, CRYAB, Hsp27, Hsp60 and Hsp70 mRNA levels were upregulated at 3 h (p < 0.01), and protein levels were increased for CRYAB at 0 h (p < 0.05) and 1 h (p < 0.01), and for Hsp70 at 3 and 5 h (p < 0.01). Thus, pre-treatment with vitamin C or vitamin C-Na might protect H9C2 cells against heat damage by enhancing the antioxidant ability and upregulating CRYAB and Hsp70.