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Background: Glutamine is crucial for the activation and efficacy of T cells, and may play a role in regulating the immune environment. This study aimed to investigate the potential role of glutamine in the activation and proliferation of induced regulatory T cells (iTregs). Methods: CD4+CD45RA1T cells were sorted from peripheral blood mononuclear cells and cultured to analyze iTreg differentiation. Glutamine was then added to the culture system to evaluate the effects of glutamine on iTregs by determining oxidative phosphorylation (OXPHOS), apoptosis, and cytokine secretion. Additionally, a humanized murine graft-versus-host disease (GVHD) model was constructed to confirm the efficacy of glutaminetreated iTregs in vivo. Results: After being cultured in vitro, glutamine significantly enhanced the levels of Foxp3, CTLA-4, CD39, CD69, IL-10, TGF-ß, and Ki67 (CTLA-4, IL-10, TGF-ß are immunosuppressive markers of iTregs) compared with that of the control iTregs (P < 0.05). Furthermore, the growth curve showed that the proliferative ability of glutaminetreated iTregs was better than that of the control iTregs (P < 0.01). Compared with the control iTregs, glutamine supplementation significantly increased oxygen consumption rates and ATP production (P < 0.05), significantly downregulated Annexin V and Caspase 3, and upregulated BCL2 (P < 0.05). However, GPNA significantly reversed the effects of glutamine (P < 0.05). Finally, a xeno-GVHD mouse model was successfully established to confirm that glutamine-treated iTregs increased the mice survival rate, delayed weight loss, and alleviated colon injury. Conclusion: Glutamine supplementation can improve the activity and immunosuppressive action of iTregs, and the possible mechanisms by which this occurs are related to cell proliferation, apoptosis, and OXPHOS. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the dynamic expression patterns of death-receptor adapter proteins TNF-receptor-associated deathdomain protein (TRADD) and Fas-associated deathdomain protein (FADD) in E.tenella-induced host-cell apoptosis. Culture techniques for primary chick embryo cecum epithelial cells, ELISA, hematoxylin-eosin staining, fluorescence quantitative PCR techniques, and Hoechst-Annexin V-PI apoptosis staining were used to detect the apoptosis rates and dynamic expression patterns of TRADD and FADD in E. tenella host cells at 4, 24, 48, 72, 96, and 120 h. The rates of early apoptosis, late apoptosis, and necrosis of E. tenella-infected group (group T0) were significantly lower (P < 0.05) or highly significantly lower (P < 0.01) than those of control group (group C) at 4 h, but higher (P < 0.05 or P < 0.01) at varying degrees than those of the same group at 24 to 120 h. Compared with group C, both the mRNA and protein expression levels of TRADD in the group T0 cells increased highly significantly (P < 0.01) at 4 and 24 h, and significantly (P < 0.05) at 48, 72, and 120 h. Compared with the mRNA expression in the group C cells, that of TRADD in the group T0 cells increased significantly (P < 0.05) at 96 h. Both the mRNA and protein expression of FADD in the group T0 cells displayed no significant difference (P > 0.05) from those in the group C cells at 4 h. However, FADD expression in the group T0 cells were significantly (P < 0.05) or highly significantly higher (P < 0.01) than those in the group C cells at 24 to 120 h. These observations indicate that in the early developmental stages of E. tenella, the host-cell apoptosis rate decreased, and TRADD expression increased. In the middle and later developmental stages of E. tenella, the host-cell apoptosis rate increased and expression of TRADD and FADD increased. The variation trends of TRADD and FADD expression were significantly positively correlated with the change rule of the host-cell apoptosis rate, respectively. These results indicate that TRADD and FADD may play an important role in E. tenella-induced host-cell apoptosis. [ABSTRACT FROM AUTHOR]

Cathepsin S is a lysosomal cysteine protease that is overexpressed in various cancer models and plays important role in tumorigenesis, however the mechanisms are unclear. In the present study, we found that inhibition of cathepsin S induced autophagy and mitochondrial apoptosis in human glioblastoma cells. Blockade of autophagy by either a chemical inhibitor or RNA interference attenuated cathespin S inhibition-induced apoptosis. Furthermore, autophagy and apoptosis induction was dependent on the suppression of phosphatidylinositide 3-kinases/protein kinase B/mammalian target of rapamycin/p70S6 kinase (PI3K/AKT/mTOR/p70S6K) signaling pathway and activation of c-Jun N-terminal kinase (JNK) signaling pathway. In addition, reactive oxygen species (ROS) served as an upstream of PI3K/AKT/mTOR/p70S6K and JNK signaling pathways. In conclusion, the current study revealed that cathepsin S played an important role in the regulation of autophagy and apoptosis in human glioblastoma cells. [ABSTRACT FROM AUTHOR]

Dietary selenium (Se) deficiency causes muscular dystrophy in various species, but the molecular mechanism remains unclear. Our objectives were to investigate: 7) if dietary Se deficiency induced different amounts of oxidative stress, lipic peroxidation, and cell apoptosis in 3 skeletal muscles; and 2) if the distribution and expression of 4 endoplasmic reticulum (ER) resident selenoprotein genes (Sepn1, Selk, Sels, and Selt) were related to oxidative damages in these muscles. Two groups of day-old layer chicks (n = 60/group) were fed a corn-soy basal diet (33 µg Se/kg; produced in the Se-deficient area of Heilongjiang, China) or the diet supplemented with Se (as sodium selenite) at 0.15 mg/kg for 55 d. Dietary Se deficiency resulted in accelerated (P < 0.05) cell apoptosis that was associated with decreased glutathione peroxidase activity and elevated lipid peroxidation in these muscles. All these responses were stronger in the pectoral muscle than in the thigh and wing muscles (P < 0.05). Relative distribution of the 4 ER resident selenoprotein gene mRNA amounts and their responses to dietary Se deficiency were consistent with the resultant oxidative stress and cell apoptosis in the 3 muscles. Expression of Sepn1, Sels. and Selt in these muscles was correlated with (r > 0.72; P< 0.05) that of Sepsecs encoding a key enzyme for biosynthesis of selenocysteine (selenocysteinyl-tRNA synthase). In conclusion, the pectoral muscle demonstrated unique expression patterns of the ER resident selenoprotein genes and GPx activity, along with elevated susceptibility to oxidative cell death, compared with the other skeletal muscles. These features might help explain why it is a primary target of Se deficiency diseases in chicks. [ABSTRACT FROM AUTHOR]

Abstract: Hypoxic ischemic (HI) injury in neonates damages brain tissues. We examined the mechanism of hyperbaric oxygen preconditioning (HBO-PC) in neonatal HI rat model. Seven-day-old rat pups were subjected to left common carotid artery ligation and hypoxia (8% oxygen at 37 °C) for 90 min. HBO (100% O2, 2.5 atmospheres absolute for 2.5 h) were administered by placing pups in a chamber 24 h before HI insult. Brain injury was assessed by the survival rate, 2,3,5-triphenyltetrazolium chloride (TTC), Nissl, TUNEL straining and caspase-3,caspase-9 activities after HI. In HBO preconditioned animals, survival rate was increased, infarct ratio was decreased, and the positive stained TUNEL cells were reduced, accompanied by the suppression of caspase-3 and -9 activities. These results indicate that a single HBO-PC appears to provide brain protection against HI insult via inhibition of neuronal apoptosis pathways. [Copyright &y& Elsevier]

The overexpress of COX-2 was clearly associated with carcinogenesis and COX-2 as a possible target has long been exploited for cancer therapy. In this work, we described the design and synthesis of a series of diarylpyrazole derivatives integrating with chrysin. Among them, compound e9 exhibited the most potent inhibitory activity against COX-2 and antiproliferative activity against Hela cells with IC 50 value of 1.12 μM. Further investigation revealed that e9 could induce apoptosis of Hela cells by mitochondrial depolarization and block the G1 phase of cell cycle in a dose-dependent manner. Besides, molecular docking simulation results was further confirmed that e9 could bind well with COX-2. In summary, compound e9 may be promising candidates for cancer therapy. [ABSTRACT FROM AUTHOR]

Targeted cell killing is required for effective treatment of cancers. We previously described the generation of a chimeric immunocasp-3 protein and its potent selective antitumor activity (Jia, L. T., Zhang, L. H., Yu, C. J., Zhao, J., Xu, Y. M., Gui, J. H., Jin, M., Ji, Z. L., Wen, W. H., Wang, C. J., Chen, S. Y., and Yang, A. G. (2003) Cancer Res. 63, 3257–3262). Here we extend the repertoire of another chimeric pro-apoptotic protein immunoGrB, which comprises an anti-HER2 single-chain antibody, a Pseudomonas exotoxin A translocation domain and active granzyme B. Human lymphoma Jurkat cells transfected with the immunoGrB gene expression vector were able to produce and secrete the chimeric protein. The immunoGrB molecule selectively recognized and destroyed HER2-overexpressing tumor cells both in vitro and in nude mouse after intramuscular injection of the immunoGrB expression plasmid. Further in vivo study showed that intravenous administration of immunoGrB gene-modified lymphocytes led to suppression of HER2-overexpressing tumor growth and prolonged animal survival because of continuous secretion of immunoGrB molecules into blood and lymph fluid. These results demonstrate that the chimeric immunoGrB molecule, which is capable of antibody-directed targeting and granzyme B-mediated killing, has therapeutic potential against HER2 tumors, especially in cases in which caspase-dependent apoptosis is inhibited. [ABSTRACT FROM AUTHOR]