Pancreatic melatonin enhances anti-tumor immunity in pancreatic adenocarcinoma through regulating tumor-associated neutrophils infiltration and NETosis

Tumor microenvironment contributes to poor prognosis of pancreatic adenocarcinoma (PAAD) patients. Proper regulation could improve survival. Melatonin is an endogenous hormone that delivers multiple bioactivities. Here we showed that pancreatic melatonin level is associated with patients' survival. In PAAD mice models, melatonin supplementation suppressed tumor growth, while blockade of melatonin pathway exacerbated tumor progression. This anti-tumor effect was independent of cytotoxicity but associated with tumor-associated neutrophils (TANs), and TANs depletion reversed effects of melatonin. Melatonin induced TANs infiltration and activation, therefore induced cell apoptosis of PAAD cells. Cytokine arrays revealed that melatonin had minimal impact on neutrophils but induced secretion of Cxcl2 from tumor cells. Knockdown of Cxcl2 in tumor cells abolished neutrophil migration and activation. Melatonin-induced neutrophils presented an N1-like anti-tumor phenotype, with increased neutrophil extracellular traps (NETs) causing tumor cell apoptosis through cell-to-cell contact. Proteomics analysis revealed that this reactive oxygen species (ROS)-mediated inhibition was fueled by fatty acid oxidation (FAO) in neutrophils, while FAO inhibitor abolished the anti-tumor effect. Analysis of PAAD patient specimens revealed that CXCL2 expression was associated with neutrophil infiltration. CXCL2, or TANs, combined with NET marker, can better predict patients' prognosis. Collectively, we discovered an anti-tumor mechanism of melatonin through recruiting N1-neutrophils and beneficial NET formation.

Effects of intrathecal TRESK gene recombinant adenovirus on inflammatory responses mediated by chemokine in spinal cord of rats with neuropathic pain / 中华麻醉学杂志

Objective To evaluate the effects of intrathecal TRESK gene recombinant adenovirus on inflammatory responses mediated by chemokine in the spinal cord of rats with neuropathic pain ( NP ) . Methods Thirty?six male Sprague?Dawley rats, weighing 200-250 g, were randomly divided into 6 groups (n=6 each) using a random number table: control group (group C); sham operation group (group S);NP group; TRESK?overexpressed adenovirus group ( group TRESK ); negative adenovirus group ( group Virus); normal saline group ( group NS) . Spinal nerve injury was produced by exposing the sciatic nerve and its branches and ligation and transection of tibial nerve and common fibular nerve in anesthetized rats. In TRESK, Virus and NS groups, pAd∕CMV∕V5?DEST?TRESK 25 μl (109IU∕ml), negative adenovirus 25 μl and normal saline 25 μl were intrathecally injected, respectively. At 1 day before operation ( base?line, T0 ) and 1, 3, 7 and 14 days after operation ( T1-4 ) , the mechanical paw withdrawal threshold ( MWT) and thermal paw withdrawal latency were measured. Six rats in each group were sacrificed after measurement of pain threshold at T3 . The L4,5 segments of the spinal cords were removed for determination of monocyte chemotactic protein?1 ( MCP?1) , MIP?2, tumor necrosis factor?alpha ( TNF?α) , interleukin?1 beta ( IL?1β) and IL?6 mRNA expression by real?time PCR. Results There was no significant difference in thermal paw withdrawal latency at each time point between groups. Compared with C and S groups, MWT at T1-4 in NP and TRESK groups and at T1-3 in Virus and NS groups were significantly decreased, and the expression of MCP?1, MIP?2, TNF?α, IL?1βand IL?6 mRNA was up?regulated in NP, TRESK, Virus and NS groups. Compared with group NP, MWT was significantly increased at T1-4, and the expres?sion of MCP?1, MIP?2, TNF?α, IL?1β and IL?6 mRNA was down?regulated in group TRESK. Conclusion The mechanism by which intrathecal TRESK gene recombinant adenovirus reduces NP is re?lated to inhibition of inflammatory responses mediated by chemokine in the spinal cord of rats.

Intracellular Signaling Pathways that Regulate Macrophage Chemokine Expression in Response to Mycobacterium abscessus

Mycobacterium abscessus (Mabc) is an emerging human pathogen. Less is known about the host immune response to Mabc than to M. tuberculosis. Here, we examined the intracellular signaling pathways that govern the expression of chemokines including (C-C motif) ligand 2 (CCL2) and (C-X-C motif) ligand 2 (CXCL2) in macrophages after infection with Mabc. Specifically, Mabc triggered the generation of reactive oxygen species (ROS) and the production of CCL2 and CXCL2 in murine bone marrow-derived macrophages (BMDMs). Mabc-induced CCL2, but not CXCL2, was dependent on the generation of ROS. Toll-like receptor (TLR) 2, MyD88, but not TRIF, was required for Mabc-induced CCL2 and CXCL2 expression. Additionally, Mabc infection significantly induced nuclear factor (NF)-kappaB nuclear translocation and luciferase activity. The activation of NF-kappaB was required for Mabc-induced CCL2, but not CXCL2 expression. Moreover, Mabc-induced ROS generation was required for NF-kappaB activation. Treatment of BMDMs with Mabc rapidly induced the activation of mitogen-activated protein kinase (MAPKs) pathways. Interestingly, CCL2 expression was dependent on the activation of JNK and ERK1/2 pathways, whereas it was negatively regulated by the p38 MAPK pathway. In contrast, Mabc-dependent CXCL2 expression was not regulated by MAPK pathways. These data suggest that intracellular ROS generation is required for innate and inflammatory responses during Mabc infection of macrophages.

Non-Steroidal Anti-Inflammatory Drugs Change Various Inflammatory Mediator-Related Gene Expression In Abeta1-42 Activated Mouse Microglial Cell

BACKGROUND: We investigated whether non-steroidal anti-inflammatory drugs(NSAIDs) could influence the expression of a few inflammatory mediator-related genes in amyloid-beta1-42(Abeta42)-activated microglia. METHODS: BV-2 cells, a murine microglial cell line, were pretreated with a single dose of 20microM of aggregated Abeta42 for 18 hours followed by incubation with ibuprofen(100microM), indomethacin(150microM) or ketorolac(10nM) for 24 hours. Expression of mRNAs for CCL7(beta-chemokine), CXCL2(alpha-chemokine), CCR7(beta-chemokine receptor), interleukin(IL)-1alpha, matrix metalloproteinase(MMP)-3, beta-secretase(BACE1) and cyclooxygenase(COX)-2 gene were measured with quantitative realtime reverse transcriptase(RT)-PCR. RESULTS: Abeta42 increased expression of mRNAs for CCL7, CXCL2, CCR7, IL-1alpha, MMP-3, BACE1 and COX-2 genes. Administration of each NSAIDs effectively lowered the expression of these genes in Abeta42-activated microglia. CONCLUSION: NSAIDs inhibit increased expression of a few cytokines, chemokine receptor and inflammatory mediatorrelated protease genes in Abeta42-activated microglia. These data demonstrate a possible mechanism how NSAIDS may decrease the risk and delay the onset of chronic neuroinflammatory process in AD.