ABSTRACT
Recent evidence suggests that CC chemokine ligand 20 (CCL20) is upregulated after subarachnoid hemorrhage (SAH). Here, we investigated the functions of CCL20 in SAH injury and its underlying mechanisms of action. We found that CCL20 is upregulated in an SAH mouse model and in cultured primary microglia and neurons. CCL20-neutralizing antibody alleviated SAH-induced neurological deficits, decreased brain water content and neuronal apoptosis, and repressed microglial activation. We observed increased levels of CCL20, CC chemokine receptor 6 (CCR6), interleukin 1 beta (IL-1ß), and tumor necrosis factor alpha (TNF-α), as well as of microglial activation in microglia treated with oxyhemoglobin (OxyHb). CCL20 or CCR6 knockdown reversed the effects of OxyHb on microglia. Conditioned medium from OxyHb-treated microglia induced neuronal apoptosis, while the percentage of apoptotic neurons in the conditioned medium from microglia transfected with CCL20 siRNA or CCR6 siRNA was decreased. We observed no decrease in OxyHb-induced apoptosis in CCL20-knockdown neurons. Conditioned medium from OxyHb-treated neurons led to microglial activation and induced CCR6, IL-1ß and TNF-α expression, while CCL20 knockdown in neurons or CCR6 knockdown in microglia reversed those effects. Our results thus suggest CCL20 may be targeted to elicit therapeutic benefits after SAH injury.
Subject(s)
Apoptosis , Chemokine CCL20/immunology , Neuroimmunomodulation , Oxyhemoglobins , Subarachnoid Hemorrhage , Animals , Antibodies, Neutralizing , Apoptosis/drug effects , Apoptosis/immunology , Cells, Cultured , Interleukin-1beta/immunology , Mice , Mice, Knockout , Microglia/drug effects , Microglia/immunology , Neuroimmunomodulation/drug effects , Neuroimmunomodulation/physiology , Neurons/drug effects , Neurons/immunology , Oxyhemoglobins/metabolism , Oxyhemoglobins/pharmacology , Receptors, CCR6/immunology , Subarachnoid Hemorrhage/drug therapy , Subarachnoid Hemorrhage/immunology , Treatment Outcome , Tumor Necrosis Factor-alpha/immunology , Up-RegulationABSTRACT
Toll-like receptors (TLR) play a pivotal role in sensing a wide range of pathogens, including bacteria, fungi and viruses. A dysregulation of TLR signaling may increase the risk of developing chronic inflammatory diseases and cancers. The aim of this study was to investigate the association of TLR2 R753Q, TLR4 D299G, and T399I polymorphisms with nasopharyngeal carcinoma (NPC) and to explore the effects of these polymorphisms on cytokine and chemokine expression in NPC biopsies. The genotypes of the three loci among 236 patients with NPC and 287 healthy controls were determined by PCR-RFLP. Cytokines and chemokines mRNA and protein in NPC biopsies were measured by real-time quantitative PCR and ELISA, respectively. Results showed that the combined CT/TT genotype of T399I was associated with increased NPC risk, with an odds ratio of 1.853 (95% confidence interval: 1.184-2.961). Also, individuals with the T allele of T399I showed a 1.842-fold increase in NPC risk compared to those with the T399I C allele (95% confidence interval: 1.213-3.015). Messenger RNA levels of interleukin (IL)-1α, tumor necrosis factor-α and IL-10 were significantly elevated in patients with T399I combined CT/TT genotype; IL-1α and IL-10 protein concentration significantly increased in NPC patients with T399I combined CT/TT genotype compared to those with the T399I CC genotype. Our data suggest that TLR4 T399I modify cytokines and chemokines patterns and play a role in the development of NPC.
