ABSTRACT
Chronic stress can suppress natural killer (NK) cell activity; this may also be related to the effect of stress on the neuroendocrine-immune network. Sea buckthorn (SBT) (Hippophae rhamnoides L.) is a thorny nitrogen fixing deciduous shrub, native to both Europe and Asia. It has been used as a medicinal plant in Tibetan and Mongolian traditional medicines. SBT has multifarious medical properties, including anti-fatigue as well as immunoregulatory effects. This study reports the effects of SBT oil with regard to the cytotoxicity and quantity of NK cells in the blood of a chronic-stress rat model, in addition to its mechanisms on the neuroendocrine-immune network. These results show that SBT oil, given by gavage to rats with chronic stress, could increase the following: body weight, NK cell quantities, and cytotoxicity, as well as the expression of perforin and granzyme B. The results also show that SBT oil in rats with chronic stress could suppress cortisol, ACTH, IL-1ß and TNF-α levels, in addition to increasing 5-HT and IFN-γ serum levels. This leads to suggest that SBT oil, in rats with chronic stress, can increase NK cell cytotoxicity by upregulating the expression of perforin and granzyme B, thus causing associated effects of SBT oil on the neuroendocrine-immune network.
Subject(s)
Hippophae , Killer Cells, Natural/immunology , Plant Oils/pharmacology , Stress, Psychological/immunology , Adrenocorticotropic Hormone/blood , Animals , Rats , Rats, Wistar , Serotonin/bloodABSTRACT
Substance P (SP) is well known for its immunoregulatory influence on NK cells. The biological actions of SP are mediated primarily through the high-affinity neurokinin-1 receptor (NK-1R), a G protein-coupled receptor (GPCR). Receptor binding triggers a cAMP signaling pathway and intracellular levels of cAMP are regulated via Gαs and Gαi. In this study NF449, a Gαs-selective G protein antagonist, was used to study the role of Gαs in the activation of NK92-MI cells by SP. Results show that 10(-12)M SP enhances the expression of Gαs and Gαi3 in NK92-MI cells promoting a cytotoxic phenotype characterized by expression of perforin and granzyme B. Development of a cytotoxic phenotype in NK92-MI cells stimulated with SP is blunted by inhibition of Gαs by NF449. In summary, SP signaling through NK-1R promotes a cytotoxic phenotype in NK92-MI cells characterized by upregulation of both Gαs and Gαi3. NF449 inhibits Gαs, blunts SP-induced expression of perforin and granzyme B, and represents a potential therapeutic avenue for reducing NK-cell mediated cytotoxicity.
Subject(s)
GTP-Binding Protein alpha Subunits, Gs/metabolism , Killer Cells, Natural/metabolism , Substance P/pharmacology , Cells, Cultured , GTP-Binding Proteins/antagonists & inhibitors , Granzymes/metabolism , Humans , K562 Cells , Killer Cells, Natural/drug effects , Perforin/metabolismABSTRACT
Substance P (SP) has been well known by its immunoregulatory properties on the functions of NK cells. However, the changes of molecules involved in the signaling pathways and effects of these molecules of NK92-MI cells activated by SP remain unclear. In this study, we explored the global changes in cellular protein expression of NK92-MI cells activated by SP by 2D-PAGE analysis. Subsequently, we demonstrated that 40 protein spots showed more than 2-fold changes, which displayed marked alterations with statistic significance (p<0.05) between the testing group and control group. Compared with the control we also found that 16 proteins were up-regulated and 24 proteins were down-regulated among the 40 differentially expressed protein spots in the NK92-MI cells activated by SP. In addition 21 differentially expressed proteins were identified by MS/MS, suggesting that those proteins may play important roles in the process of activation of NK92-MI cells by SP. Moreover, the protein Rho GDI-2, Protein DJ-1 and alpha-enolase were reconfirmed by western blotting. Taken together, these findings may provide a new insight into better understanding at the molecular mechanisms of activation of NK92-MI cells by SP.
Subject(s)
Killer Cells, Natural/drug effects , Proteomics/methods , Substance P/pharmacology , Animals , Blotting, Western , Cell Line , Computational Biology , Databases, Genetic , Electrophoresis, Polyacrylamide Gel , Image Processing, Computer-Assisted , Nerve Tissue Proteins/biosynthesis , Nerve Tissue Proteins/genetics , Signal Transduction/drug effects , Spectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationABSTRACT
Objective:To study the effects of dexamethasone(DEX)on the cytotoxicity and apoptosis of NK-92MI cells and the mechanisms involved.Methods:NK-92MI cells were treated with different doses of DEX.The proliferative rate and cytotoxicity of the NK-92MI cells were detected by MTT colorimetry.The cell apoptotic rate was observed by flow cytometry with Annexin V and propidium iodide(PI)double staining.The expression of apoptosis-related gene,Bcl-2 and Bax was detected by RT-PCR.Results:After treated with 1?10-8mol/L to 1?10-3mol/L of DEX for 24 h,48 h and 72 h,the proliferation of NK-92MI cells was significant inhibited(P
