interleukin-8 and fludarabine

Interleukin-27 (IL-27) is a cytokine which belongs to the IL-12 family. However, the role of IL-27 in the pathogenesis of periodontal disease is uncertain. The aim of this study was to examine the effect of IL-27 on chemokine production in TNF-α-stimulated human oral epithelial cells (TR146).. We measured chemokine production in TR146 by ELISA. We used western blot analysis to detect the phosphorylation levels of signal transduction molecules, including STAT1 and STAT3 in TR146. We used inhibitors to examine the role of STAT1 and STAT3 activation.. IL-27 increased CXCR3 ligands production in TNF-α-stimulated TR146. Meanwhile, IL-27 suppressed IL-8 and CCL20 production induced by TNF-α. STAT1 phosphorylation level in IL-27 and TNF-α-stimulated TR146 was enhanced in comparison to TNF-α-stimulated TR146. STAT3 phosphorylation level in IL-27-treated TR146 did not change by TNF-α. Both STAT1 inhibitor and STAT3 inhibitor decreased CXCR3 ligands production. STAT1 inhibitor overrode the inhibitory effect of IL-27 on IL-8 and CCL20 production in TNF-α-stimulated TR146. Meanwhile, STAT3 inhibitor did not modulate IL-8 and CCL20 production.. IL-27 might control leukocyte migration in periodontal lesion by modulating chemokine production from epithelial cells.

Topics: Cell Line; Chemokine CCL20; Chemokines; Humans; Interleukin-27; Interleukin-8; Mouth Mucosa; Phosphorylation; Pyridines; Receptors, Interleukin; Signal Transduction; STAT1 Transcription Factor; STAT3 Transcription Factor; Tumor Necrosis Factor-alpha; Tyrphostins; Vidarabine

How neuroinflammatory activities affect signaling pathways leading to blood-brain barrier (BBB) injury during HIV/AIDS are currently unknown. Our previous work demonstrated that HIV-1 exposure activates pro-inflammatory genes in human brain microvascular endothelial cells (HBMEC) and showed that these genes are linked to the janus kinase (JAK)/signal transducers and activators of transcription (STAT) pathway. Here, we report that HIV-1 gp120 protein activated STAT1 and induced interleukin (IL)-6 and IL-8 secretion in HBMEC. IL-6, IL-8, and gp120 increased monocyte adhesion and migration across in vitro BBB models. The STAT1 inhibitor, fludarabine, prevented gp120-induced IL-6 and IL-8 secretion. Inhibitors of STAT1, mitogen activated protein kinase kinase (MEK) (PD98059), and phosphatidyl inositol 3 kinase (PI3K) (LY294002), blocked gp120-induced STAT1 activation and significantly diminished IL-8-, IL-6-, and gp120-induced monocyte adhesion and migration across in vitro BBB models. These data support the notion that STAT1 plays an important role in gp120-induced inflammation and BBB dysfunction associated with viral infection. Results also suggest crosstalk between STAT1, MEK, and PI3K pathways in gp120-induced BBB dysfunction. Inhibition of STAT1 activation could provide a unique therapeutic strategy to decrease neuroinflammation and BBB dysfunction in HIV/AIDS.

Topics: AIDS Dementia Complex; Blood-Brain Barrier; Brain; Cell Adhesion; Cell Movement; Cells, Cultured; Chromones; Cytokines; Endothelial Cells; Enzyme Inhibitors; Flavonoids; HIV Envelope Protein gp120; HIV-1; Humans; Interleukin-6; Interleukin-8; Microvessels; Mitogen-Activated Protein Kinase Kinases; Models, Neurological; Monocytes; Morpholines; Phosphoinositide-3 Kinase Inhibitors; Signal Transduction; STAT1 Transcription Factor; Vidarabine

B chronic lymphocytic leukemia (B-CLL) cells express several members of the tumor necrosis factor (TNF) family, such as CD40L, CD30L, and TRAIL. By using the cDNA microarray technology, B-CLL samples were found to overexpress receptor activator of nuclear factor kB (NF-kB) ligand (RANKL), as compared to normal CD19(+) B cells. These findings were validated at the protein level by Western blot and flow cytometry analyses. Moreover, unlike primary normal B cells, leukemic B-CLL cells showed surface expression of RANK, the cognate transmembrane receptor of RANKL. When added in vitro to B-CLL cultures, either alone or in association with chlorambucil or fludarabine, recombinant RANKL did not significantly modulate cell viability, and it minimally affected the IL-8 expression/release. On the other hand, treatment with RANK-Fc chimera potently upregulated the release of IL-8 in the B-CLL culture supernatants, suggesting involvement of reverse signaling through transmembrane RANKL in IL-8 induction. In turn, exposure of B-CLL cells to recombinant IL-8 significantly decreased spontaneous apoptosis as well as chlorambucil- and fludarabine-mediated cytoxicity in B-CLL cells. Since IL-8 has been implicated in progression of B-CLL disease, our findings suggest that, by upregulating IL-8, the RANKL/RANK system may contribute to the pathogenesis of B-CLL.

Topics: Antineoplastic Agents; Apoptosis; Blotting, Western; Carrier Proteins; Cell Survival; Chlorambucil; Flow Cytometry; Gene Expression; Glycoproteins; Humans; Immunoglobulin G; Interleukin-1; Interleukin-8; Leukemia, Lymphocytic, Chronic, B-Cell; Membrane Glycoproteins; Oligonucleotide Array Sequence Analysis; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, TNF-Related Apoptosis-Inducing Ligand; Receptors, Tumor Necrosis Factor; Recombinant Fusion Proteins; Reverse Transcriptase Polymerase Chain Reaction; Tumor Cells, Cultured; Up-Regulation; Vidarabine

Fludarabine is a nucleoside analogue that has been successfully employed for the treatment of low-grade lymphoid malignancies and, more recently, in nonmyeloablative preparative regimens for stem cell transplantation, due to its strong cytotoxic activity on lymphocytes. In this paper, we show that fludarabine can also induce pro-inflammatory stimulation of monocytic cells, as evaluated by increased expression of ICAM-1 and IL-8 release. To study the mechanisms involved, we employed selective inhibitors of MAPK and NF-kappaB pathways, both of which have been implicated in the modulation of ICAM-1 and IL-8. Our results showed that fludarabine effects were mediated through the activation of ERK and were independent on p38, JNK or NF-kappaB pathways. By Western blotting analysis we corroborated that fludarabine induced a rapid activation of ERK that was sustained for at least 30 min. Moreover, pro-inflammatory activation of monocytic cells by fludarabine was largely attenuated by coadministration of the free radical scavenger N-acetylcysteine suggesting the involvement of reactive oxygen species in fludarabine effects. Finally, we showed that fludarabine induced the activation of the transcription factor AP-1 not only in monocytic cells but also in non-proliferating lymphocytes from chronic lymphocytic leukemia. It is possible that some of fludarabine side effects in vivo may be attributed to cell activation/differentiation rather than induction of apoptosis.

Topics: Antineoplastic Agents; Apoptosis; B-Lymphocytes; Extracellular Signal-Regulated MAP Kinases; Humans; Immunosuppressive Agents; Intercellular Adhesion Molecule-1; Interleukin-8; Monocytes; Transcription Factor AP-1; U937 Cells; Vidarabine