vasoactive-intestinal-peptide and Acute-Lung-Injury

Vasoactive intestinal peptide (VIP) is a neuropeptide that exerts anti-inflammatory functions. We have reported that VIP mediated by lentivirus attenuates acute lung injury (ALI) in lipopolysaccharide (LPS)-induced murine model. However, the exact role of VIP in uncontrolled inflammation during ALI is largely unknown. Accumulating evidence indicates that the NLRP3 inflammasome has a critical role during ALI. In this study, we investigated the effects of VIP on the activation of NLRP3 inflammasome during the development of ALI in mice. Seven days after the intratracheal injection of VIP-lentivirus, a murine ALI model was induced by intratracheal injection of LPS. VIP-lentivirus significantly reduced the expression of NLRP3 inflammasome components in lung tissue, including NLRP3, pro-caspase-1, pro-IL-1β, and pro-IL-18. VIP-lentivirus also inhibited the formation of caspase-1 p10 and the maturation of IL-1β and IL-18. In vitro, exogenous VIP pre-treatment inhibited the priming of NLRP3 inflammasome in murine primary peritoneal macrophages, indicated by down-regulation of expression of NLRP3 inflammasome components. VIP pre-treatment effectively prevented the LPS-induced degradation of I-κB and the synthesis of the downstream of NF-κB, including TNF-α and IL-17A. Furthermore, VIP pre-treatment pronouncedly suppressed the autoproteolysis of caspase-1 and the secretion of IL-1β and IL-18 induced by LPS plus ATP in macrophages. In addition, VIP inhibited the generation of reactive oxygen species in macrophages by decreasing NOX1 and NOX2 expression. These findings illustrate one mechanism that VIP attenuates ALI induced by LPS through inhibiting the activation of the NLRP3 inflammasome and encourage further studies assessing the therapeutic potential of VIP to ALI.

Topics: Acute Lung Injury; Animals; Cells, Cultured; Lipopolysaccharides; Macrophages; Male; Mice; NLR Family, Pyrin Domain-Containing 3 Protein; Random Allocation; Vasoactive Intestinal Peptide

Vasoactive intestinal peptide (VIP) is one of the most abundant neuropeptides in the lungs with various biological characters. We have reported that VIP inhibited the expressions of TREM-1 and IL-17A, which are involved in the initiation and amplification of inflammation in acute lung injury (ALI). However, the overall effect of VIP on ALI remains unknown. The aim of this study is to investigate the therapeutic effect of VIP mediated by lentivirus (Lenti-VIP) on lipopolysaccharide (LPS)-induced murine ALI. We found that the expression of intrapulmonary VIP peaked at day7 after the intratracheal injection of Lenti-VIP. Lenti-VIP increased the respiratory rate, lung compliance, and tidal volume, while decreased airway resistance in ALI mice, detected by Buxco system. Lenti-VIP significantly reduced inflammatory cell infiltration and maintained the integrity of the alveolar septa. Lenti-VIP also remarkably decreased the total protein level, the number of neutrophil and lactate dehydrogenase activity in the bronchoalveolar lavage fluid of LPS-induced ALI mice. In addition, Lenti-VIP down-regulated pro-inflammatory tumor necrosis factor (TNF)-α mRNA and protein expression, while up-regulated anti-inflammatory interleukin-10 mRNA and protein expression in lungs of ALI mice. Furthermore, we observed that VIP reduced the TNF-α expression in murine macrophages under LPS stimulation through protein kinase C and protein kinase A pathways. Together, our findings show that in vivo administration of lentivirus expressing VIP exerts a potent therapeutic effect on LPS-induced ALI in mice via inhibiting inflammation.

Topics: Acute Lung Injury; Animals; Cytoprotection; Disease Models, Animal; Down-Regulation; Genetic Therapy; Genetic Vectors; Inflammation; Lentivirus; Lipopolysaccharides; Macrophages, Alveolar; Male; Mice; Transfection; Vasoactive Intestinal Peptide

Mosla scabra (Thunb.) C.Y. Wu and H.W. Li has been used as a traditional medicinal herb for centuries in East Asian countries. It has antibacterial, antiviral, antioxidant, anti-inflammatory and immunomodulatory effects. In folk medicine, it is used as a remedy for the treatment of pulmonary diseases, such as fever, cold, cough, pulmonary edema and emphysema.. This study was to investigate the protective mechanism of total flavonoids from M. scabra (MF) in influenza A virus (IAV)-infected mice.. The mice were infected with IAV and then were treated daily with MF for five days. At the end of the experiment, the levels of inflammatory-related cytokines (IFN-α, IL-6, TNF-α and IL-1β) were determined by ELISA. Pathological changes of lung tissue were examined by H&E staining. The protein expressions of AQP5, p-p38, caspase-3 and NF-κB p65 were detected by western blot analysis while the gene expressions of key effectors in AQP5 and PRRs signaling pathways were detected by real-time Fluorescence Quantitative Polymerase Chain Reaction (RFQ-PCR) analysis.. The results showed that treatment with MF at doses of 120-360mg/kg for five days to IAV-infected mice significantly attenuated IAV-induced pulmonary injury and decreased the serum levels of IL-6, TNF-α and IL-1β, but increased IFN-α levels. MF treatment could up-regulate the mRNA expressions of TLR-7, RIG-1, TRAF6, Bcl-2, Bax, VIPR1, PKCα and AQP5 and down-regulate caspase-3 and NF-κB p65 protein expression.. Treatment with MF could significantly alleviate IAV-induced pulmonary inflammation, apoptosis and water transport abnormality, which was probably through the regulation of TLR7, RIG-1 and AQP5 signaling pathway.

Topics: Acute Lung Injury; Animals; Antiviral Agents; Aquaporins; Body Water; Cytokines; Flavonoids; Humans; Influenza A virus; Influenza, Human; Lamiaceae; Lung; Male; Mice; Mice, Inbred ICR; Receptors, Pattern Recognition; Signal Transduction; Vasoactive Intestinal Peptide

Interleukin (IL)-17A is a pro-inflammatory cytokine that markedly enhances inflammatory responses in the lungs by recruiting neutrophils and interacting with other pro-inflammatory mediators. Reducing the expression of IL-17A could attenuate inflammation in the lungs. However, whether VIP exerts its anti-inflammatory effects by regulating the expression of IL-17A has remained unclear. Here, we show that there is a remarkable increase of IL-17A in bronchoalveolar lavage fluid (BALF) and lung tissue of mice with acute lung injury (ALI). Moreover, lipopolysaccharides (LPS) stimulated elevated expression of IL-17A, which was evident by the enhanced levels of mRNA and protein observed. Furthermore, we also found that VIP inhibited LPS-mediated IL-17A expression in a time- and dose-dependent manner in an in vitro model of ALI and that this process might be mediated via the phosphokinase A (PKA) and phosphokinase C (PKC) pathways. Taken together, our results demonstrated that VIP might be an effective protector during ALI by suppressing IL-17A expression.

Topics: Acute Lung Injury; Animals; Bronchoalveolar Lavage Fluid; Cyclic AMP-Dependent Protein Kinases; Disease Models, Animal; Down-Regulation; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation; Inflammation; Inflammation Mediators; Interleukin-17; Macrophages; Male; Mice; Protein Kinase C; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Vasoactive Intestinal Peptide

Vasoactive intestinal peptide (VIP) is one of the most plentiful neuropeptides in the lung and it has anti-inflammatory effects in the respiratory system. Triggering receptors expressed on myeloid cells-1 (TREM-1) and triggering receptors expressed on myeloid cells-2 (TREM-2) regulate immune responses to lipopolysaccharide (LPS). In the present study, we tested the expressions of TREM-1 and TREM-2 in various pulmonary cell lines and/or tissue using an animal model of LPS-induced acute lung injury (ALI), and determined the effects of VIP on expression of the TREM-1 and TREM-2 in lung tissues and cells from ALI mice. We found 1) expression of the TREM-1 mRNA from lung tissues of ALI was significantly increased, whereas the expression of TREM-2 mRNA was decreased in these tissues; 2) TREM-1 mRNA was only expressed in macrophages, while TREM-2 mRNA was detected in HBECs, lung fibroblasts, lung adenocarcinoma cells and macrophages; 3) the ratio of TREM-1 mRNA to TREM-2 mRNA was increased in LPS-induced lung tissues and macrophages; 4) VIP inhibited expression of the TREM-1 mRNA in a time- and dose-dependent manner in lung cells from LPS-induced ALI mice; however, it increased expression of the TREM-2 mRNA. As a result of these effects, VIP normalized the ratio of TREM-1 to TREM-2 mRNA in these cells. Our results suggest that VIP might exert its anti-inflammatory effect through a mechanism involved in regulation of expression of the TREM-1 and TREM-2 in LPS-induced ALI.

Topics: Acute Lung Injury; Adenocarcinoma; Adenocarcinoma of Lung; Animals; Anti-Inflammatory Agents; Cell Line, Tumor; Disease Models, Animal; Dose-Response Relationship, Drug; Gene Expression Regulation; Inflammation; Lipopolysaccharides; Lung; Lung Neoplasms; Male; Membrane Glycoproteins; Mice; Myeloid Cells; Neoplasms; Neuroprotective Agents; Receptors, Immunologic; RNA, Messenger; Triggering Receptor Expressed on Myeloid Cells-1; Vasoactive Intestinal Peptide

Vasoactive intestinal peptide (VIP) is a neuro-peptide that can modulate immunity. Previous studies indicated that VIP can attenuate the deleterious consequences of severe sepsis and septic shock by regulating production of inflammatory cytokines in immune activated cells. The signaling induced by bacterial components occurs primarily through Toll like receptors (TLRs). TLRs have been recognized to play a key role in pathogen recognition and innate immunity. It was convincingly demonstrated that lung is one of early suffered disaster organ and may trigger multiple organ dysfunction syndrome in sepsis. The present study was conducted to investigate the effects of VIP on TLR2/4 mRNA expressions on acute lung injury of endotoxic shock induced by lipopolysaccharide (LPS) in rat.. Forty Sprague-Dawley rats were randomly divided into 3 groups, i.e., LPS shock group (n = 16), LPS + VIP group (n = 16), and control group (n = 8). LPS shock model was established by LPS (E. coli O(55)B(5) 10 mg/kg) with tail intravenous injection. The rats in LPS + VIP group were given a bolus of 5 nmol VIP intravenous injection follow by LPS. The rats in control group were given normal saline. The rats were sacrificed at 6 h, 24 h after being injected. The lung tissues were collected. The TLR2 mRNA and TLR4 mRNA expressions were detected by RT-PCR from the lung tissues. Pathological changes of the lungs were observed by light microscope and electron microscope 24 h after LPS injection.. (1) Lung histopathology: the alveolar space was full with leukocyte, necrotic cells, segmental hemorrhage and protein effusion. Partial alveolar space was enlarged, lung interstitial edema were observed in LPS shock group. However, pathological changes of LPS + VIP group were milder than those in LPS shock group. (2) The expressions of TLR2 mRNA and TLR4 mRNA were significantly higher in LPS shock group compared with those of the control group (F = 16.638, P = 0.000; t = 5.876, P = 0.000), TLR2 mRNA and TLR4 mRNA expression on 24 h was down-regulated in LPS + VIP shock subgroup than those in LPS shock subgroup (F = 16.676, P = 0.000; t = 3.946, P < 0.001).. Expressions of TLR2 mRNA and TLR4 mRNA were up-regulated on LPS induced lung injury in rats. VIP mitigated lung injury induced by LPS, which may be related to TLR2 mRNA and TLR4 mRNA down-regulation of expression. The effect of VIP may suggest a protective mechanism in sepsis. VIP may play a potential protective role in severe infection.

Topics: Acute Lung Injury; Animals; Down-Regulation; Lipopolysaccharides; Lung; Male; Rats; Rats, Sprague-Dawley; RNA, Messenger; Toll-Like Receptor 2; Toll-Like Receptor 4; Up-Regulation; Vasoactive Intestinal Peptide