Vasoactive intestinal peptide inhibits the activation of murine fibroblasts and expression of interleukin 17 receptor C.

Acute respiratory distress syndrome (ARDS) is an acute, severe, and refractory pulmonary inflammation with high morbidity and mortality. Excessive activation of fibroblast during the fibroproliferative phase plays a pivotal role in the prognosis of ARDS. Our previous study demonstrated that the vasoactive intestinal peptide (VIP) is mediated by lentivirus attenuates lipopolysaccharide (LPS)-induced ARDS in a murine model, and VIP inhibits the release of interleukin-17A (IL-17A) from activation macrophages. However, the effects of VIP on the activation of murine fibroblast and expression of IL-17 receptor (IL-17R) in ARDS remain unclear. Here, a mouse model of ARDS was established by an intratracheal injection of LPS. We found that the gene expression of col3a1 and hydroxyproline contents in the lungs were significantly increased 24 h after LPS injection. IL-17RC rather than IL-17RA was increased in the lungs of mice with ARDS. In vitro, LPS activated NIH3T3 cells, which was suppressed by VIP in a dose-dependent manner. In detail, VIP reduced the hydroxyproline content and col3a1 messenger RNA induced by LPS in NIH3T3 cells, as well as the expression of α-smooth muscle actin. Furthermore, we found that VIP inhibited the expression of IL-17R in the lungs of mice with ARDS and NIH3T3 cells stimulated with LPS, which was partly inhibited by antagonists of protein kinase A and protein kinase C. Taken together, our results demonstrated that VIP inhibited the activation of fibroblast via downregulation of IL-17RC, which may contribute to the protective effects of VIP against ARDS in mice.

Folate treatment of pregnant rat dams abolishes metabolic effects in female offspring induced by a paternal pre-conception unhealthy diet.

AIMS/HYPOTHESIS: Paternal high-fat diet prior to mating programmes impaired glucose tolerance in female offspring. We examined whether the metabolic consequences in offspring could be abolished by folate treatment of either the male rats before mating or the corresponding female rats during pregnancy. METHODS: Male F0 rats were fed either control diet or high-fat, high-sucrose and high-salt diet (HFSSD), with or without folate, before mating. Male rats were mated with control-diet-fed dams. After mating, the F0 dams were fed control diet with or without folate during pregnancy. RESULTS: Male, but not female offspring of HFSSD-fed founders were heavier than those of control-diet-fed counterparts (p < 0.05 and p = 0.066 in males and females, respectively). Both male and female offspring of HFSSD-fed founders were longer compared with control (p < 0.01 for both sexes). Folate treatment of the pregnant dams abolished the effect of the paternal diet on the offspring's body length (p Ë‚ 0.05). Female offspring of HFSSD-fed founders developed impaired glucose tolerance, which was restored by folate treatment of the dams during pregnancy. The beta cell density per pancreatic islet was decreased in offspring of HFSSD-fed rats (-20% in male and -15% in female F1 offspring, p Ë‚ 0.001 vs controls). Folate treatment significantly increased the beta cell density (4.3% and 3.3% after folate supplementation given to dams and founders, respectively, p Ë‚ 0.05 vs the offspring of HFSSD-fed male rats). Changes in liver connective tissue of female offspring of HFSSD-fed founders were ameliorated by treatment of dams with folate (p Ë‚ 0.01). Hepatic Ppara gene expression was upregulated in female offspring only (1.51-fold, p Ë‚ 0.05) and was restored in the female offspring by folate treatment (p Ë‚ 0.05). We observed an increase in hepatic Lcn2 and Tmcc2 expression in female offspring born to male rats exposed to an unhealthy diet during spermatogenesis before mating (p Ë‚ 0.05 vs controls). Folate treatment of the corresponding dams during pregnancy abolished this effect (p Ë‚ 0.05). Analysis of DNA methylation levels of CpG islands in the Ppara, Lcn2 and Tmcc2 promoter regions revealed that the paternal unhealthy diet induced alterations in the methylation pattern. These patterns were also affected by folate treatment. Total liver DNA methylation was increased by 1.52-fold in female offspring born to male rats on an unhealthy diet prior to mating (p Ë‚ 0.05). This effect was abolished by folate treatment during pregnancy (p Ë‚ 0.05 vs the offspring of HFSSD-fed male rats). CONCLUSIONS/INTERPRETATION: Folate treatment of pregnant dams restores effects on female offspring's glucose metabolism induced by pre-conception male founder HFSSD.

Terminal Deoxynucleotidyl Transferase and T7 Exonuclease-Aided Amplification Strategy for Ultrasensitive Detection of Uracil-DNA Glycosylase.

As one of the key initiators of the base excision repair process, uracil-DNA glycosylase (UDG) plays an important role in maintaining genomic integrity. It has been found that aberrant expression of UDG is associated with a variety of diseases. Thus, accurate and sensitive detection of UDG activity is of critical significance for biomedical research and early clinical diagnosis. Here, we developed a novel fluorescent sensing platform for UDG activity detection based on a terminal deoxynucleotidyl transferase (TdT) and T7 exonuclease (T7 Exo)-aided recycling amplification strategy. In this strategy, only two DNA oligonucleotides (DNA substrate containing one uracil base and Poly dT probe labeled with a fluorophore/quencher pair) are used. UDG catalyzes the removal of uracil base from the enclosed dumbbell-shape DNA substrate to give an apyrimidinic site, at which the substrate oligonucleotide is cleaved by endonuclease IV. The released 3'-end can be elongated by TdT to form a long deoxyadenine-rich (Poly dA) tail, which may be used as a recyclable template to initiate T7 Exo-mediated hybridization-digestion cycles of the Poly dT probe, giving a significantly enhanced fluorescence output. The proposed UDG-sensing strategy showed excellent selectivity and high sensitivity with a detection limit of 1.5 × 10-4 U/mL. The sensing platform was also demonstrated to work well for UDG inhibitor screening and inhibitory activity evaluation, thus holding great potential in UDG-related disease diagnosis and drug discovery. The proposed strategy can be easily used for the detection of other DNA repair-related enzymes by simply changing the recognition site in DNA substrate and might also be extended to the analysis of some DNA/RNA-processing enzymes, including restriction endonuclease, DNA methyltransferase, polynucleotide kinase, and so on.

Soluble epoxide hydrolase inhibitor 1-trifluoromethoxyphenyl-3- (1-propionylpiperidin-4-yl) urea attenuates bleomycin-induced pulmonary fibrosis in mice.

Epoxyeicosatrienoic acids (EETs), the metabolites of arachidonic acid derived from the cytochrome P450 (CYP450) epoxygenases, are mainly metabolized by soluble epoxide hydrolase (sEH) to their corresponding diols. EETs but not their diols, have anti-inflammatory properties and inhibition of sEH might provide protective effects against inflammatory fibrosis. We test the effects of a selected sEH inhibitor, 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU), on bleomycin-induced pulmonary fibrosis (PF) in mice. A mouse model of PF was established by intratracheal injection of bleomycin and TPPU was administered for 21 days after bleomycin injection. We found TPPU treatment improved the body weight loss and survival rate of bleomycin-stimulated mice. Histological examination showed that TPPU treatment alleviated bleomycin-induced inflammation and maintained the alveolar structure of the pulmonary tissues. TPPU also decreased the bleomycin-induced deposition of collagen and the expression of procollagen I mRNA in lung tissues of mice. TPPU decreased the transforming growth factor-ß1 (TGF-ß1), interleukin-1ß (IL-1ß) and IL-6 levels in the serum of bleomycin-stimulated mice. Furthermore, TPPU inhibited the proliferation and collagen synthesis of mouse fibroblasts and partially reversed TGF-ß1-induced α-smooth muscle actin expression. Our results indicate that the inhibition of sEH attenuates bleomycin-induced inflammation and collagen deposition and therefore prevents bleomycin-induced PF in a mouse model.

Vasoactive intestinal peptide suppresses macrophage-mediated inflammation by downregulating interleukin-17A expression via PKA- and PKC-dependent pathways.

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.

Progress in the research of cuproptosis and possible targets for cancer therapy.

Developing novel cancer therapies that exploit programmed cell death pathways holds promise for advancing cancer treatment. According to a recently published study in Science, copper death (cuproptosis) occurs when intracellular copper is overloaded, triggering aggregation of lipidated mitochondrial proteins and Fe-S cluster proteins. This intriguing phenomenon is triggered by the instability of copper ions. Understanding the molecular mechanisms behind cuproptosis and its associated genes, as identified by Tsvetkov, including ferredoxin 1, lipoic acid synthase, lipoyltransferase 1, dihydrolipid amide dehydrogenase, dihydrolipoamide transacetylase, pyruvate dehydrogenase α1, pyruvate dehydrogenase ß, metallothionein, glutaminase, and cyclin-dependent kinase inhibitor 2A, may open new avenues for cancer therapy. Here, we provide a new understanding of the role of copper death and related genes in cancer.

Role of CREB in vasoactive intestinal peptide-mediated wound healing in human bronchial epithelial cells.

Vasoactive intestinal peptide (VIP) is one of the most important sensory neuropeptides in respiratory system. We previously reported that VIP enhances wound healing and proliferation of human bronchial epithelial cells (HBECs), and these effects are mediated by intracellular signaling molecules such as protein kinase A (PKA), protein kinase C (PKC), Calmodulin (CaM), and extracellular signal-regulated kinase (ERK). In the present study, we further investigated the role of cAMP Response Element Binding Protein (CREB) in VIP-promoted protective effects in mechanical-damaged HBECs. VIP-mediated wound healing and cell proliferation in HBECs was inhibited by CREB antisense oligonucleotides (ASO) in a time-dependent manner. VIP increased the CREB DNA binding activity and expression of the p-CREB that were inhibited by VIP receptor antagonist. Increased CREB DNA binding activity and expression of the p-CREB were also partially inhibited by PKA and ERK inhibitors. These results suggest that the VIP-mediated wound repair of HBECs is associated with activation of CREB via PKA and ERK dependent pathway.

Terminal Deoxynucleotidyl Transferase-Catalyzed Preparation of pH-Responsive DNA Nanocarriers for Tumor-Targeted Drug Delivery and Therapy.

Developing a highly efficient carrier for tumor-targeted delivery and site-specific release of anticancer drugs is a good way to overcome the side effects of traditional cancer chemotherapy. Benefiting from the nontoxic and biocompatible characteristics, DNA-based drug carriers have attracted increasing attention. Herein, we reported a novel and readily manipulated strategy to construct spherical DNA nanocarriers. In this strategy, terminal deoxynucleotidyl transferase (TdT)-catalyzed DNA extension reaction is used to prepare a thick DNA layer on a gold nanoparticle (AuNP) surface by extending long poly(C) sequences from DNA primers immobilized on AuNPs. The poly(C) extension products can then hybridize with G-rich oligonucleotides to give CG-rich DNA duplexes (for loading anticancer drug doxorubicin, Dox) and multiple AS1411 aptamers. Via synergic recognition of multiple aptamer units to nucleolin proteins, biomarker of malignant tumors, Dox-loaded DNA carrier can be efficiently internalized in cancer cells and achieve burst release of drugs in acidic organelles because of i-motif formation-induced DNA duplex destruction. An as-prepared pH-responsive drug carrier was demonstrated to be promising for highly efficient delivery of Dox and selective killing of cancer cells in both in vitro and in vivo experiments, thus showing a huge potential in anticancer therapy.

Vasoactive intestinal peptide overexpression mediated by lentivirus attenuates lipopolysaccharide-induced acute lung injury in mice by inhibiting inflammation.

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.

[Effect of calcitonin-gene-related peptide on MMP-9 production in human bronchial epithelial cells].

OBJECTIVE: To examine the expression of matrix metalloproteinase-9 (MMP-9) in human bronchial epithelial cells treated with calcitonin-gene-related peptide (CGRP). METHODS: RT-PCR and gelatin zymography were performed to examine the dynamic expression and activity of MMP-9 in human bronchial epithelial cells at different doses (10(-10), 10(-9), 10(-8), 10(-7), and 10(-6)mol/L) and different time points (6,12,18,24,36, and 48h) after the stimulation of CGRP. RESULTS: The unstimulated human bronchial epithelial cells only secreted a small amount of MMP-9. After the CGRP stimulation, the expression of MMP-9 presented in a concentration-dependent (10(-10), 10(-9), 10(-8), 10(-7), and 10(-6) mol/L) and time-dependent (6,12,18,24,36, and 48 h) manners (P<0.01) in human bronchial epithelial cells. The effect of CGRP could be diminished by H-7 and W-7, an antagonist of protein kinase C (PKC) and calmodulin (CaM) (P<0.05). CONCLUSION: CGRP can stimulate the secretion and expression of MMP-9 in human bronchial epithelial cells, and the signal transduction is partly via the PKC and CaM pathway.

Aucubin Alleviates Bleomycin-Induced Pulmonary Fibrosis in a Mouse Model.

Pulmonary fibrosis is a life-threatening disease characterized by progressive dyspnea and worsening of pulmonary function. No effective therapeutic strategy for pulmonary fibrosis has been established. Aucubin is a natural constituent with a monoterpene cyclic ring system. The potency of aucubin in protecting cellular components against inflammation, oxidative stress, and proliferation effects is well documented. In this study, we investigated the protective effect of aucubin against pulmonary fibrosis in mice. A mouse model of pulmonary fibrosis was established by intratracheal injection of bleomycin (BLM), and aucubin was administered for 21 days after BLM injection. We found that aucubin decreased the breathing frequency and increased the lung dynamic compliance of BLM-stimulated mice detected by Buxco pulmonary function testing system. Histological examination showed that aucubin alleviated BLM-induced lung parenchymal fibrotic changes. Aucubin also reduced the intrapulmonary collagen disposition and inflammatory injury induced by BLM. In addition, aucubin reduced the expression of pro-fibrotic protein transforming growth factor (TGF)-ß1 and α-smooth muscle actin (α-SMA) of pulmonary fibrosis mice induced by BLM. Furthermore, the effect of aucubin on the proliferation and differentiation of fibroblast was investigated in vitro. Aucubin inhibited the mRNA and protein expression of Ki67 and proliferating cell nuclear antigen (PCNA) induced by TGF-ß1 and reduced the cell proliferation in a murine fibroblast cell NIH3T3. Aucubin also reduced the collagen syntheses and α-SMA expression induced by TGF-ß1 in fibroblast. Our results indicate that aucubin inhibits inflammation, fibroblast proliferation, and differentiation, exerting protective effects against BLM-induced pulmonary fibrosis in a mouse model. This study provides an evidence that aucubin may be a novel drug for pulmonary fibrosis.

Soluble Epoxide Hydrolase Inhibitor Attenuates Lipopolysaccharide-Induced Acute Lung Injury and Improves Survival in Mice.

Acute lung injury (ALI) is characterized by rapid alveolar injury, vascular leakage, lung inflammation, neutrophil accumulation, and induced cytokines production leading to lung edema. The mortality rate of patients suffering from ALI remains high. Epoxyeicosatrienoic acids (EETs) are cytochrome P450-dependent derivatives of polyunsaturated fatty acid with antihypertensive, profibrinolytic, and anti-inflammatory functions. EETs are rapidly hydrated by soluble epoxide hydrolase (sEH) to their less potent diols. The aim of this study was to investigate the role of sEH inhibitor trifluoromethoxyphenyl propionylpiperidin urea (TPPU) and EETs in lipopolysaccharide (LPS)-induced ALI of mice. Our studies revealed that inhibition of sEH with TPPU attenuated the morphological changes in mice, decreased the neutrophil infiltration to the lung, pro-inflammatory cytokine levels (IL-1ß and TNF-α) in serum and bronchoalveolar lavage fluid (BALF), and alveolar capillary leakage (lung wet/dry ratio and total protein concentration in BALF). TPPU improved the survival rate of LPS-induced ALI. In addition, in vitro experiments revealed that both TPPU and EETs (11,12-EET and 14,15-EET) suppressed the expression of IL-1ß and TNF-α, and LDH release in RAW264.7 cells. These results indicate that EETs play a role in dampening LPS-induced acute lung inflammation, and suggest that sEH could be a valuable candidate for the treatment of ALI.

[Expression of epithelial-cadherin, CD44v6 and connexin43 in hepatocellular carcinoma].

OBJECTIVE: To study the expression of epithelial-cadherin (E-cad), CD44v6 and Cx43 in hepatocellular carcinoma (HCC) and its relationship with sex and age of patients, as well as tumor histopathologic grades. METHODS: Double immunofluorescent staining and laser scanning confocal microscopy was used to study the expression of E-cad, CD44v6 and Cx43 in 30 cases of normal liver tissue, 25 cases of benign hepatic lesions and 38 cases of HCC. In the HCC group, correlation of antigen expression with sex and age of patients and tumor histopathologic grades was studied by T-test. RESULTS: Significant decrease in expression of E-cad and Cx43 was noted in HCC group, as compared to normal liver tissue and benign hepatic lesion (P<0.05). On the other hand, CD44v6 expression was higher in HCC group than in the other two groups (P<0.05). In HCC group, the expression of E-cad and Cx43 did not correlate with sex, age and histopathologic grades (P>0.05). However, CD44v6 expression positively correlated with higher tumor histopathologic grades (P<0.05) but not sex and age of patients (P>0.05). In HCC group, the expression of E-cad positively correlated with that of Cx43, while the expression of CD44v6 negatively correlated with that of E-cad and Cx43. CONCLUSIONS: Tumor immunophenotype alters during development and progression of HCC. Low expression of E-cad and Cx43 and high expression of CD44v6 may be related to aggressive clinical behavior of HCC, moreover, high expression of CD44v6 correlated with high tumor grades. Detection of E-cad, CD44v6 and Cx43 expression may thus be useful in predicting prognosis of HCC.

Blocking triggering receptor expressed on myeloid cells-1 attenuates lipopolysaccharide-induced acute lung injury via inhibiting NLRP3 inflammasome activation.

Acute lung injury (ALI) is associated with high mortality and uncontrolled inflammation plays a critical role in ALI. TREM-1 is an amplifier of inflammatory response, and is involved in the pathogenesis of many infectious diseases. NLRP3 inflammasome is a member of NLRs family that contributes to ALI. However, the effect of TREM-1 on NLRP3 inflammasome and ALI is still unknown. This study aimed to determine the effect of TREM-1 modulation on LPS-induced ALI and activation of the NLRP3 inflammasome. We showed that LR12, a TREM-1 antagonist peptide, significantly improved survival of mice after lethal doses of LPS. LR12 also attenuated inflammation and lung tissue damage by reducing histopathologic changes, infiltration of the macrophage and neutrophil into the lung, and production of the pro-inflammatory cytokine, and oxidative stress. LR12 decreased expression of the NLRP3, pro-caspase-1 and pro-IL-1ß, and inhibited priming of the NLRP3 inflammasome by inhibiting NF-κB. LR12 also reduced the expression of NLRP3 and caspase-1 p10 protein, and secretion of the IL-1ß, inhibited activation of the NLRP3 inflammasome by decreasing ROS. For the first time, these data show that TREM-1 aggravates inflammation in ALI by activating NLRP3 inflammasome, and blocking TREM-1 may be a potential therapeutic approach for ALI.

TGF-ß1 Upregulates the Expression of Triggering Receptor Expressed on Myeloid Cells 1 in Murine Lungs.

Triggering receptor expressed on myeloid cells 1 (TREM-1) increases the expression of TGF-ß family genes, which are known as profibrogenic cytokines in the pathogenesis of pulmonary fibrosis. In this study, we determined whether TGF-ß1 regulated the expression of TREM-1 in a mouse model of pulmonary fibrosis. The expression of TGF-ß1 and TREM-1 was increased on day 7, 14, and 21 after single intratracheal injection of bleomycin (BLM). And there was positive correlation between the expression of TGF-ß1 and TREM-1. TGF-ß1 increased expression of TREM-1 mRNA and protein in a time- and dose-dependent manner in mouse macrophages. The expression of the activator protein 1 (AP-1) was increased in lung tissues from mouse after BLM injection and in mouse macrophages after TGF-ß1 treatment, respectively. TGF-ß1 significantly increased the relative activity of luciferase in the cells transfected with plasmid contenting wild type-promoter of TREM-1. But TGF-ß1 had no effect on the activity of luciferase in the cells transfected with a mutant-TREM1 plasmid carrying mutations in the AP-1 promoter binding site. In conclusion, we found the expression of TREM-1 was increased in lung tissues from mice with pulmonary fibrosis. TGF-ß1 increased the expression of TREM-1 in mouse macrophages partly via the transcription factor AP-1.

Calcitonin gene-related peptide promotes the wound healing of human bronchial epithelial cells via PKC and MAPK pathways.

Calcitonin gene-related peptide (CGRP) is a 37-amino acid neuropeptide derived from the calcitonin gene. CGRP is widely distributed in the central and peripheral neuronal systems. In the lung, CGRP could modulate dendritic cell function, stimulate proliferation of alveolar epithelial cells and mediate lung injury in mice. In this study, we investigated the effect of CGRP on the wound healing of human bronchial epithelial cells (HBECs) in vitro. The results showed that CGRP accelerated the recovery of wound area of monolayer HBECs in a dose-dependent manner. CGRP inhibited the lipopolysaccharide-induced apoptosis in HBECs. The percentage of S phase and G2/M phase was increased in HBECs after CGRP treatment. CGRP upregulated the expression of Ki67 in a dose-dependent manner. Some pathway inhibitors were used to investigate the signal pathway in which CGRP was involved. We found out that PKC pathway inhibitor (H-7) and MAPK pathway inhibitor (PD98059) could partially attenuate the effect of CGRP, which indicated that CGRP might promote the wound healing of HBECs via PKC and/or MAPK dependent pathway by accelerating migration and proliferation, and inhibiting apoptosis.

[Effects of CGRP on the E-cadherin expression in human bronchial epithelial cells].

OBJECTIVE: To discuss the effect of calcitonin gene-related peptides (CGRP) on epithelial cadherin (E-cd) expression in human bronchial epithelial cells (HBECs) in vitro. METHODS: The effect of CGRP on E-cd protein and mRNA expression in both normal and O3-challenged HBECs were determined by immunocytochemistry and RT-PCR. The signal transduction pathways of CGRP were observed by using protein kinase C(PKC) inhibitor (H-7), calmodulin(CaM) inhibitor (W-7) and PKA inhibitor (H-89). RESULTS: CGRP increased E-cd mRNA and protein expressions of normal and O3-challenged HBECs in a dose-dependent manner. CGRP had no effect on cytoplasm E-cd expression. Pre-treatment with H-89, H-7 and W-7, the up-regulatory effect of CGRP on E-cd expression was partly abolished. CONCLUSION: CGRP increased in cytomembrane E-cd expression of normal and O3-challenged HBECs in a dose-dependent manner. E-cd expression on HBECs was strengthened by CGRP via PKA, PKC and CaM pathways.

Vasoactive intestinal peptide re-balances TREM-1/TREM-2 ratio in acute lung injury.

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.