Interleukin 8 enhances the immune response of ducks to avian influenza vaccine

Fluid shear stress-induced IL-8/CXCR signaling in human ovarian cancer cells

Background

Interleukin-8 (IL-8) released from mechanosensitive cancer cells plays a key role in the inflammation and metastasis of solid carcinomas. In this study, we have explored IL-8 and its receptors signal transduction process of human ovarian cancer cells under conditions of FSS.

Methods

After the fluid shear stress was loaded, LightCycler™ system and quantitative sandwich ELISA were employed to assay the IL-8 mRNA expression and protein production, respectively. IL-8 reporter gene pEGFP1-IL8USCS was constructed for determining IL-8 gene transcriptional activation through gene transfer and flow cytometric analysis. NF-κB nuclear translocation was observed by immunocytofluorescent staining. Western blot was used to examine IκB phosphorylation and degradation. RT-PCR, Northern blot and immunofluorescence were used to determine the expression of a cell-surface chemokine receptor CXCR2 at mRNA and protein levels.

Results

IL-8 mRNA expression and protein production had biphasic responses to low shear stress (1.5 dyne/cm²), with the peaks at 1 and 2 h respectively. There was an increase in enhanced green fluorescent protein expression in pEGFP1-IL8USCS-transfected SKOV3 cells subjected to a fluid shear stress of 1.5 dyne/cm² for 2 h. Following the application of shear stress of 1.5 dyne/cm², NF-κB p65 became detectable in the cell nuclei, and Phosphorylated IκB in cell lysates increased significantly. CXCR2, which was constitutively present on the surface of SKOV3 cells, increased following exposure to fluid shear stress for 60 min.

Conclusions

Fluid shear stress triggered IL-8/CXCR2 signaling of SKOV3 cells is an early gene activation, and the activation can be mediated through NF-κB. This observation suggested that fluid shear stress-induced IL-8 activation and the downstream signal pathways may have an important contribution to the pathogenesis and development of both inflammation and metastasis of ovarian carcinomas.

Functional identification and expressional responses of large yellow croaker (Larimichthys crocea) interleukin-8 and its receptor

Interleukin-8 (IL-8 or chemokine (C-X-C motif) ligand 8, CXCL8) is a chemokine produced by multiple cell types. It promotes chemotaxis and phagocytosis via interaction with chemokine receptors CXCR1 and CXCR2. Using published data, IL-8 gene (LcIL-8) of the large yellow croaker (Larimichthys crocea) was cloned into the pcDNA3.1 plasmid, and an interleukin-8 receptor (LcCXCR2) was cloned into the pEGFP-N1 plasmid. Secratory expression of LcIL-8 in HEK293T cells was carried out, and product in culture medium was collected for LcCXCR2 stimulation in HEK293 cells. Following receptor internalization observation and intracellular signaling detection, the functional interaction of LcIL-8 and LcCXCR2 was further determined and the ERK phosphorylation signal activation mediated by LcCXCR2 was demonstrated. Quantitative real-time PCR analysis was used to analyze transcription level regulation of LcIL-8 and LcCXCR2 in various tissues of large yellow croaker. Expression of LcIL-8 and LcCXCR2 was elevated in the spleen, head kidney, and liver after Vibrio parahemolyticus challenge. Results illustrated the functional interaction between LcIL-8 and LcCXCR2 in mediating intracellular ERK1/2 phosphorylation signaling and suggested that the LcIL-8 and LcCXCR2 system is part of the immune response induced by V. Parahemolyticus in L. crocea.

The Comparison of Adipose Stem Cell and Placental Stem Cell in Secretion Characteristics and in Facial Antiaging

Background. Mesenchymal stem cells are the most commonly used seed cells in biomedical research and tissue engineering. Their secretory proteins have also been proven to play an important role in tissue healing. Methods. We isolated adipose stem cells and placental stem cells and performed analysis examining characteristics. The secretory proteins were extracted from conditioned medium and analyzed by MALDI-TOF/TOF. The antiaging effect of conditioned mediums was evaluated by the results of facial skin application. Results. Adipose stem cells and placental stem cells were found to be very similar in their surface markers and multipotency. The specific proteins secreted from adipose stem cells were more adept at cell adhesion, migration, wound healing, and tissue remodeling, while the proteins secreted by placental stem cells were more adept at angiogenesis, cell proliferation, differentiation, cell survival, immunomodulation, and collagen degradation. While these two types of conditioned medium could improve the facial index, the improvement of Melanin index after injection of the adipose stem cell conditioned medium was much more significant. Conclusion. The results suggest that the secreted proteins are ideal cell-free substances for regeneration medicine, especially in the antiaging field.