IL-1β In Lung Tissue Research Articles

Regulatory effect of hemichannels protein Pannexin-1 on P2X7 receptor activity in the lungs of mice with lung injury

To investigate the regulative effect of hemichannels protein Pannexin-1 on P2X7 receptor activation and caspase-1 mediated inflammatory response in the lungs of mice with lung injury. Sixty male C57BL/6 mice were randomly divided into five groups with 12 mice in each group: sham operation group (Sham group), mechanical ventilation (MV) group, MV + low dose lipopolysaccharide (LPS) group (MLL group), MV + medium and high dose LPS group (MML group) and MV + high dose LPS group (MHL group). A "two-hit" lung injury model was reproduced by MV with high tidal volume combined with LPS injection in airway. All the mice underwent tracheotomy and intubation. After operation, the mice in Sham group were maintained spontaneous breathing, and those in other four groups were put on small animal ventilators to give MV with a large tidal volume of 28 mL/kg. After stable respiration in mice, those in the Sham group and MV group were injected 8 mL/kg of normal saline (NS) into the airway, and those in MLL, MML and MHL groups were given 2, 5 and 8 mg/kg of LPS respectively (diluted with NS into 8 mL/kg). After 4 hours on MV, the mice were sacrificed, and bronchoalveolar lavage fluid (BALF) was extracted to determine intracellular and extracellular ATP concentration. Lung tissue was harvested and water containing ratio of lungs was measured. The degree of lung pathological damage was observed after hematoxylin-eosin (HE) staining, and lung injury score was calculated. The expression of Pannexin-1 protein in lung tissue was calculated with immunohistochemistry. Western Blot and fluorescence quantitative reverse transcription-polymerase chain reaction (RT-qPCR) were used to detect the protein and mRNA expressions of Pannexin-1, P2X7 receptor, caspase-1 and interleukin-1β (IL-1β). There was no obvious pathological change in lung tissue in Sham group, intracellular ATP concentration was higher than extracellular ATP concentration, water content in lung tissue was lower, Pannexin-1 expression was low in lung tissue by immunohistochemical staining, and Pannexin-1, P2X7 receptor, caspase-1 and IL-1β were only expressed in micro-protein and mRNA in lung tissue. Compared with the Sham group, the alveolar lesions and hemorrhages in the MV group were not obvious, and lung injury score was slightly increased. There was no significant fluctuation between intracellular ATP concentration and extracellular ATP concentration. The water content in lung tissue was increased significantly, while the expressions of Pannexin-1, P2X7 receptor, caspase-1 and IL-1β in lung tissue were increased slightly. After LPS intervention, progressively increased lung exudation, ruptured alveoli, dilated capillaries, and inflammatory cells were found, and lung injury score was increased without significant difference among the three LPS doses groups. With the increase in LPS dosage, the concentration of extracellular ATP in BALF was increased, the concentration of intracellular ATP was decreased, the water containing ratio of lung tissue was increased gradually, and the protein and mRNA expressions of Pannexin-1, P2X7 receptor, caspase-1 and IL-1β in lung tissue were increased gradually in a dose-dependent manner. The parameters in MHL group showed significant differences as compared with those in MV group [lung injury score: 8.25±0.45 vs. 3.50±0.52; intracellular ATP concentration (μmol/L): 198.76±150.77 vs. 896.69±281.11, extracellular ATP concentration (μmol/L): 336.57±90.28 vs. 141.52±42.22; lung water containing rate: (6.37±0.11)% vs. (5.05±0.14)%; Pannexin-1 protein (gray value): 3.20±0.70 vs. 1.54±0.76, Pannexin-1 mRNA (2-ΔΔCT): 7.86±0.86 vs. 2.47±0.92; P2X7 receptor protein (gray value): 3.18±0.88 vs. 1.80±0.72, P2X7 receptor mRNA (2-ΔΔCT): 7.17±0.96 vs. 2.31±0.45; caspase-1 protein (gray value): 3.00±0.45 vs. 0.93±0.51, caspase-1 mRNA (2-ΔΔCT): 4.39±0.91 vs. 2.74±0.41; IL-1β protein (gray value): 2.54±1.08 vs. 1.16±0.53, IL-1β mRNA (2-ΔΔCT): 132.34±41.48 vs. 19.67±8.67; all P < 0.05]. Pannexin-1 may be involved in LPS and MV induced lung injury, which may be regulated by intracellular release of ATP to the extracellular site and binding to P2X7 receptor on the cell surface, thereby regulating active caspase-1 production and release, involving in the production of IL-1β and other inflammatory factors eventually which leads to the occurrence and development of lung injury.

Evaluation of mRNA Expression Levels of TNFα, TNFR1 and IL1β in Lung Tissue 20 Years after Sulfur-mustard Exposure.

Despite many years having passed since exposure to sulfur mustard (SM) gas, there are many exposed subjects who are still suffering from delayed pulmonary complications. The levels of pro-inflammatory cytokines in the lung of these subjects have not been investigated in delay phase. In this study, we evaluated mRNA expression of pro-inflammatory cytokines (tumor necrosis factor alpha (TNFα), tumor necrosis factor receptor type 1 (TNFR1), and interleukin 1 beta (IL-1β) ) in lung biopsy of SM-exposed subjects and compared them with control (non-exposed) subjects. We used formalin-fixed, paraffin-embedded (FFPE) tissue for this purpose. Lung FFPE blocks of SM-exposed subjects (30 samples) and a control group (30 samples) were collected from archival pathology department. The total mRNA of FFPE tissues were extracted and the mRNA expression of pro-inflammatory cytokines were determined by quantitative Real Time PCR (RT-qPCR). The obtained results from two groups were compared to each other and non-parametric statistical analyses were carried out on them. Our studies showed that the mRNA expression of TNFα, TNFR1 and IL-1β in lung tissue of SM injured and control people have no significant difference (p-value= 0.159, 0.832 and 0.314 respectivly). TNFR1 showed direct correlation with TNFα (r=0.867, p=0.002) and IL-1β (r= 0.65, p=0.006). The evaluation of mRNA expression in pro-inflammatory cytokines in lung of SM-exposed subjects after 20 years showed that these mediators are similar to those of non-exposed group and there was no acute inflammation in lung of these patients.

Mechanism of lung injury of rats induced by inhalation of white smoke from burning smoke pot

Objective: To explore mechanism of lung injury of rats induced by inhalation of white smoke from burning smoke pot. Methods: Forty-eight Sprague Dawley rats were divided into control group (n=12) and injury group (n=36) according to the random number table. Rats in injury group were placed in smoke-induced injury experimental equipment fulled with white smoke from burning smoke pot for 5 minutes to make lung injury, and rats in control group were placed in smoke-induced injury experimental equipment fulled with air for 5 minutes to make sham injury. Six rats in injury group at post injury hour (PIH) 6, 24, and 72 and six rats in control group at PIH 72 were collected to observe pathological changes of lung tissue and pathological score of rats in the two groups by hematoxylin-eosin staining, to detect expression of nuclear factor-κB (NF-κB) p65 mRNA in lung tissue of rats by reverse transcriptional polymerase chain reaction, and to detect content of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-6 in lung tissue of rats by enzyme-linked immunosorbent assay. Data were processed with one-way analysis of variance and t test. Results: At PIH 72, lung tissue structure of rats in control group was clear and complete, with no inflammatory cell infiltration. At PIH 6, there was edema, hemorrhage, and inflammatory cell infiltration in lung tissue of rats in injury group. At PIH 24, edema, hemorrhage, and inflammatory cell infiltration in lung tissue of rats in injury group aggravated. At PIH 72, area of edema in lung tissue of rats in injury group was enlarged, with obvious hemorrhage and inflammatory cell infiltration. At PIH 6, 24, and 72, pathological score of lung tissue of rats in injury group was (3.43±0.86), (5.39±0.93), and (9.99±0.84) points, respectively, obviously higher than that of rats in control group at PIH 72 [(2.11±0.20) points, t=3.659, 8.450, 22.355, P<0.05]. As time post injury prolonged, pathological scores of lung tissue of rats in injury group were significantly increased (F=121.244, P<0.01). At PIH 6, 24, and 72, expression of NF-κB p65 mRNA in lung tissue of rats in injury group was 15.5±4.3, 25.9±1.8, 30.9±3.5 respectively, significantly higher than that of rats in control group at PIH 72 (7.8±0.8, t=4.315, 20.445, 14.408, P<0.01). As time post injury prolonged, expression of NF-κB p65 mRNA in lung tissue of rats in injury group gradually increased (F=32.691, P<0.01). At PIH 6, 24, and 72, content of TNF-α, IL-1β, and IL-6 in lung tissue of rats in injury group was significantly higher than that of rats in control group at PIH 72, respectively (t=7.650, 8.968, 6.827, 6.726, 8.978, 3.460, 5.420, 13.289, 16.438, P<0.01). At PIH 24, content of TNF-α and IL-1β in lung tissue of rats in injury group was higher than that of rats in the same group at PIH 6 and 72, respectively (t=3.409, -2.549, 4.047, -4.100, P<0.05). At PIH 24 and 72, content of IL-6 in lung tissue of rats in injury group was respectively higher than that of rats in the same group at PIH 6 (t=8.273, 9.711, P<0.05). Conclusions: After inhaling white smoke from burning smoke pot, rats are inflicted with lung injury by increasing expression of NF-κB p65 mRNA and content of TNF-α, IL-1β, and IL-6, and induce pathological changes of edema, hemorrhage, and inflammatory cell infiltration of lung tissue.

Knockdown of LncRNA MALAT1 contributes to the suppression of inflammatory responses by up-regulating miR-146a in LPS-induced acute lung injury

ABSTRACTBackground: Acute lung injury (ALI) is a type of severe pulmonary inflammatory disease with high rates of morbidity and mortality. Now, an increasing number of studies suggest that lncRNAs may act as key regulators of the inflammatory response and play a crucial role in the pathogenesis of many inflammatory diseases. Our study firstly explored the function and underlying mechanism of lncRNA metastasis-associated lung adenocarcinoma transcription 1 (MALAT1) in regulating the inflammatory response of lipopolysaccharide (LPS)-induced ALI in rats. Methods: The ALI rats were constructed by intratracheal instillation with LPS. Hematoxylin and eosin (HE) for histological examination were performed to detect histopathological changes in the lung tissues. Enzyme-linked immunosorbent assay (ELISA) was used to determine the concentrations of cytokines TNF-α, IL-6, and IL-1β in the supernatants of the bronchoalveolar lavage fluid (BALF). Quantitative real-time PCR (qRT-PCR) analysis was employed to assess the expression of MALAT1, miR-146a, TNF-α, IL-6, and IL-1β in lung tissues. Luciferase reporter assay and RNA immunoprecipitation (RIP) assay were used to detect the relationship between MALAT1 and miR-146a. Results: The results revealed that MALAT1 knockdown played a protective role in the LPS-induced ALI rat model. In addition, knockdown of MALAT1 in vitro inhibited LPS-induced inflammatory response in murine alveolar macrophages cell line MH-S and murine alveolar epithelial cell line MLE-12. This study found that MALAT1 acts as a molecular sponge for miR-146a and MALAT1 negatively regulated miR-146a expression. Mechanistically, MALAT1 overexpression alleviated the inhibitory effect of miR-146a on LPS-induced inflammatory response in MH-S. Conclusions: Together, our study provided the first evidence that MALAT1 knockdown could suppress inflammatory response by up-regulating miR-146a in LPS-induced ALI, which provided a potential therapeutic target for the treatment of ALI.

Luteolin attenuates acute lung injury in experimental mouse model of sepsis

The present investigation was undertaken to assess the result of pretreatment of luteolin in sepsis-induced acute lung injury in mice and its mechanism of action. Luteolin was administered intraperitoneally one hour before caecal ligation and puncture (CLP) surgery in mice. Acute lung injury was assessed by estimation of different parameters like lung edema, protein content, cytokines level, oxidative stress, inducible nitric oxide synthase (iNOS), intercellular adhesion molecule (ICAM)-1 expression and histopathology. Pretreatment of mice with luteolin showed decrease lung edema and protein content in tissue and bronchoalveolar lavage fluid (BALF). However, mice pretreated with luteolin showed reduction (p = 0.92) in blood and lung tissue bacterial counts however it was non significant. Further, luteolin showed significant reduction in interleukin (IL)-6 and IL-1β in lung tissue which are the proinflammatory cytokines. However, plasma IL-1β and tissue tumor necrosis factor (TNF)-α level decrease (p = 0.24; p = 0.19) with this pretreatment. Further, ICAM-1 mRNA expression and nuclear factor (NF)-kappa B protein expression were significantly (p < 0.01) decreased in luteolin pretreated septic mice. The lung iNOS level, iNOS mRNA and protein expressions were markedly (p = 0.25; p = 0.50; p = 0.06) altered with luteolin pretreatment, respectively. Also, significant reduction in lipid peroxidation and increase in the activity of antioxidant enzymes like superoxide dismutase (SOD) and catalase was noted with luteolin pretreatment. However, luteolin did not alter (p = 0.36) the non enzymatic antioxidant GSH activity in septic mice. Histopathology of lung tissue showed reduction in lung injury with the luteolin pretreatment in septic mice. The study suggests that luteolin showed attenuation in sepsis-induced acute lung injury in mice through suppression in ICAM-1, NF-kappa B, oxidative stress and partially iNOS pathways.

A role for heat shock factor 1 in hypercapnia-induced inhibition of inflammatory cytokine expression.

Hypercapnia, elevated levels of CO2 in the blood, is a known marker for poor clinical prognosis and is associated with increased mortality in patients hospitalized with both bacterial and viral pneumonias. Although studies have established a connection between elevated CO2 levels and poor pneumonia outcomes, a mechanistic basis of this association has not yet been established. We previously reported that hypercapnia inhibits expression of key NF-κB-regulated, innate immune cytokines, TNF-α, and IL-6, in LPS-stimulated macrophages in vitro and in mice during Pseudomonas pneumonia. The transcription factor heat shock factor 1 (HSF1) is important in maintaining proteostasis during stress and has been shown to negatively regulate NF-κB activity. In this study, we tested the hypothesis that HSF1 activation in response to hypercapnia results in attenuated NF-κB-regulated gene expression. We found that hypercapnia induced the protein expression and nuclear accumulation of HSF1 in primary murine alveolar macrophages and in an alveolar macrophage cell line (MH-S). In MH-S cells treated with short interfering RNA targeting Hsf1, LPS-induced IL-6 and TNF-α release were elevated during exposure to hypercapnia. Pseudomonas-infected Hsf1+/+ (wild-type) mice, maintained in a hypercapnic environment, showed lower levels of IL-6 and TNF-α in bronchoalveolar lavage fluid and IL-1β in lung tissue than did infected mice maintained in room air. In contrast, infected Hsf1+/- mice exposed to either hypercapnia or room air had similarly elevated levels of those cytokines. These results suggest that hypercapnia-mediated inhibition of NF-κB cytokine production is dependent on HSF1 expression and/or activation.-Lu, Z., Casalino-Matsuda, S. M., Nair, A., Buchbinder, A., Budinger, G. R. S., Sporn, P. H. S., Gates, K. L. A role for heat shock factor 1 in hypercapnia-induced inhibition of inflammatory cytokine expression.

The activation of NLRP3-inflammsome by stimulation of diesel exhaust particles in lung tissues from emphysema model and RAW 264.7 cell line.

Background/AimsDiesel exhaust particles (DEPs) lead to elevation of reactive oxygen species, which can activate the nucleotide-binding oligomerization domain-like receptor (NLR) family members containing the pyrin domain 3 (NLRP3)-inf lammasome. In this study, we elucidated whether NLRP3 -inf lammasome is activated by DEPs and whether antioxidants (N-acetylcysteine [NAC]) could inhibit such activation.MethodsRAW 264.7 cells and ex vivo lung tissues explants obtained from elastase-induced emphysema animal models were stimulated with cigarette smoking extract (CSE), DEPs, and lipopolysaccharide, and levels of interleukin-1β (IL-1β), caspase-1 and nucleotide-binding oligomerization domain-like receptor (NLR) family members containing the pyrin domain (NLRP3)-inflammasome were assessed by Western blotting and immunohistochemistry.ResultsNAC and caspase-1 inhibitor suppressed CSE- and DEP-induced secretion of IL-1β in RAW 264.7 cells. The expression levels of the NLRP3-inflammasome and caspase-1 were upregulated in RAW 264.7 cells by stimulation with CSE and DEPs and were inhibited by NAC. CSE and DEPs increased the secretion of IL-1β in lung tissues from both the normal and elastase-induced emphysema groups. The secretion of IL-1β by CSE and DEPs was increased in the elastin-induced emphysema group more than that in the normal group (CSE: 309 ± 19 pg/mL vs. 151 ± 13 pg/mL, respectively, p < 0.05; DEP: 350 ± 24 pg/mL vs. 281 ± 15 pg/mL, respectively, p < 0.05). NAC inhibited CSE- and DEP-induced IL-1β secretion in both the normal and elastase-induced emphysema groups. NLRP3-inflammasome expression as determined by immunohistochemistry was increased by CSE and DEPs in both the normal and elastin-induced emphysema groups, and was suppressed by NAC.ConclusionsThe NLRP3-inf lammasome is activated by DEPs in ex vivo tissue explants from elastase-induced emphysema animal model, and this activation is inhibited by NAC.

Correlation Between Tumor Necrosis Factor-α and Interleukin-1β in Exhaled Breath Condensate and Pulmonary Function

BackgroundExhaled breath condensate (EBC) has emerged as a noninvasive method for assessing inflammation in lung diseases. Our aim is to investigate the correlation between tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) in EBC and in lung tissue, and between these values in EBC with pulmonary function tests in patients with chronic obstructive pulmonary disease (COPD). Materials and MethodsTo ensure the availability of lung tissue, 60 patients undergoing resection for early lung cancer were divided into 3 groups: a COPD treatment group, a COPD control group and a non-COPD group. Patients in the COPD treatment group received what was termed “lung-protective treatment” including ambroxol, budesonide and ipratropium bromide in addition to chest physiotherapy. Patients underwent pulmonary function testing and EBC collection, and TNF-α and IL-1β were detected by enzyme-linked immunosorbent assay (ELISA). TNF-α and IL-1β in lung tissues were evaluated by immunoflorescense. Correlations were analyzed by Pearson correlation coefficients. ResultsThe TNF-α and IL-1β levels in EBC were significantly higher in the COPD groups compared with the non-COPD group before surgery (all P < 0.01), and the levels were significantly decreased after lung-protective treatment was received before surgery (all P < 0.01). TNF-α and IL-1β levels in EBC were significantly decreased in all patients after surgery with lung-protective treatment (P = 0.027, P = 0.004). TNF-α and IL-1β content in lung tissues was significantly higher in the COPD groups (all P < 0.05), and the histologic analysis showed similar results. Negative correlations between FEV1/FVC and expression of TNF-α and IL-1β were observed. There was a positive correlation between TNF-α and IL-1β in lung tissues and in EBC. ConclusionsTNF-α and IL-1β in EBC are potential biomarkers for evaluating pulmonary function and inflammation in patients with COPD. Furthermore, lung-protective treatment is effective in reducing inflammation in patients with COPD.

Anti-inflammatory Effects of Phyllanthus emblica L on Benzopyrene-Induced Precancerous Lung Lesion by Regulating the IL-1β/miR-101/Lin28B Signaling Pathway.

Background. Phyllanthus emblica L (PEL), a well-known medical plant, has been used in Asian countries for a long time. Increasing evidence suggests that it can prevent the tumorigenesis of cancer associated with nonresolving inflammation. However, the possible anti-inflammatory mechanism responsible for preventing tumorigenesis of precancerous lung lesions is not well elucidated. Materials and methods. Male A/J mice were randomly divided into 5 groups with 10 mice in each group: (1) blank group (saline), (2) benzo(a)pyrene [B(a)P] group, (3) and (4) B(a)P + PEL (5 g/kg/d, 10 g/kg/d, administered by gavage), (5) B(a)P + celecoxib (30 mg/kg/d, administered by gavage). Nodes on the lung surface were observed and calculated. The levels of macrophage inflammatory protein (MIP-2), tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-1β were detected by enzyme-linked immunosorbent assay (ELISA) kits. Cyclo-oxygenase-2 (COX-2), hypoxia-inducible factor-1 (HIF-α), IL-1β, miR-101, and Lin28B protein levels were evaluated by immunohistochemistry and Western blotting. Results. PEL extract treatment significantly reduced the number of nodes on the lung surface and attenuated B(a)P-induced levels of proinflammatory cytokines MIP-2, TNF-α, IL-6, and IL-1β in lung tissue. The protein expressions of COX-2 and HIF-α were significantly decreased by the treatment of PEL. In addition, both PEL extract and celecoxib markedly upregulate the expression of miR-101 while downregulating IL-1β and Lin28B levels. Conclusion. Our study indicated that treatment with PEL extract can not only protect the lung from inflammatory injury but effectively prevent precancerous lung lesions through regulating the IL-1β/miR-i101/Lin28B signaling pathway.

Methyl Protodioscin from the Roots of Asparagus cochinchinensis Attenuates Airway Inflammation by Inhibiting Cytokine Production.

The present study was designed to find pharmacologically active compound against airway inflammation from the roots of Asparagus cochinchinensis. The 70% ethanol extract of the roots of A. cochinchinensis (ACE) was found to inhibit IL-6 production from IL-1β-treated lung epithelial cells (A549) and the major constituent, methyl protodioscin (MP), also strongly inhibited the production of IL-6, IL-8, and tumor necrosis factor- (TNF-) α from A549 cells at 10–100 μM. This downregulating effect of proinflammatory cytokine production was found to be mediated, at least in part, via inhibition of c-Jun N-terminal kinase (JNK) and c-Jun activation pathway. When examined on an in vivo model of airway inflammation in mice, lipopolysaccharide- (LPS-) induced acute lung injury, ACE, and MP significantly inhibited cell infiltration in the bronchoalveolar lavage fluid by the oral treatment at doses of 100–400 mg/kg and 30–60 mg/kg, respectively. MP also inhibited the production of proinflammatory cytokines such as IL-6, TNF-α, and IL-1β in lung tissue. All of these findings provide scientific evidence supporting the role of A. cochinchinensis as a herbal remedy in treating airway inflammation and also suggest a therapeutic value of MP on airway inflammatory disorders.

Pulmonary Inflammation After Intraperitoneal Administration of Ultrafine Titanium Dioxide (TiO2) At Rest or in Lungs Primed with Lipopolysaccharide

Nanoparticles are widely used in nanomedicines, including for targeted delivery of pharmacological, therapeutic, and diagnostic agents. Since nanoparticles might translocate across cellular barriers from the circulation into targeted organs, it is important to obtain information concerning the pathophysiologic effects of these particles through systemic migration. In the present study, acute pulmonary responses were examined after intraperitoneal (ip) administration of ultrafine titanium dioxide (TiO2, 40 mg/kg) in mice at rest or in lungs primed with lipopolysaccharide (LPS, ip, 5 mg/kg). Ultrafine TiO2 exposure increased neutrophil influx, protein levels in bronchoalveolar lavage (BAL) fluid, and reactive oxygen species (ROS) activity of BAL cells 4 h after exposure. Concomitantly, the levels of proinflammatory mediators, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and macrophage inflammatory protein (MIP)-2 in BAL fluid and mRNA expression of TNF-α and IL-1β in lung tissue were elevated post ultrafine TiO2 exposure. Ultrafine TiO2 exposure resulted in significant activation of inflammatory signaling molecules, such as c-Src and p38 MAP kinase, in lung tissue and alveolar macrophages, and the nuclear factor (NF)-κB pathway in pulmonary tissue. Furthermore, ultrafine TiO2 additively enhanced these inflammatory parameters and this signaling pathway in lungs primed with lipopolysaccharide (LPS). Contrary to this trend, a synergistic effect was found for TNF-α at the level of protein and mRNA expression. These results suggest that ultrafine TiO2 (P25) induces acute lung inflammation after ip administration, and exhibits additive or synergistic effects with LPS, at least partly, via activation of oxidant-dependent inflammatory signaling and the NF-κB pathway, leading to increased production of proinflammatory mediators.

Expression of inflammation-related cytokines following intratracheal instillation of nickel oxide nanoparticles

The objective of this study was to examine what kinds of cytokines are related to lung disorder by well-dispersed nanoparticles. The mass median diameter of nickel oxide in distilled water was 26 nm. Rats intratracheally received 0.2 mg of nickel oxide suspended in distilled water, and were sacrificed from three days to six months. The concentrations of 21 cytokines including inflammation, fibrosis and allergy-related ones were measured in the lung. Infiltration of alveolar macrophages was observed persistently in the nickel oxide-exposed group. Expression of macrophage inflammatory protein-1α showed a continued increase in lung tissue and broncho-alveolar lavage fluid (BALF) while interleukin-1α (IL-1α), IL-1β in lung tissue and monocyte chemotactic protein-1 in BALF showed transient increases. Taken together, it was suggested that nano-agglomerates of nickel oxide nanoparticles have a persistent inflammatory effect, and the transient increase in cytokine expression and persistent increases in CC chemokine were involved in the persistent pulmonary inflammation.

Hypercapnic Emphysema in C3H Mice Induced by Cigarette Smoke (CS) Demonstrates Pulmonary Inflammation Concomitant With Increased Matrix Metalloproteinases (MMPs) and Substance P (SP)

We have recently established a model of CS-induced emphysema in C3H mice characterized by hypercapnia and depressed ventilatory response that closely resembles the major features of patients with hypercapnic chronic obstructive pulmonary disease (COPD). COPD is often associated with pulmonary inflammation. Previous studies have shown that increased MMP activity, IL-1β and SP are involved in inflammatory process, and the former two may be involved in pulmonary parenchymal destruction associated with emphysema and the latter is implicated in airway remodeling. Therefore, we asked whether this animal model has pulmonary inflammation, and if so, whether MMPs, IL-1β, SP and its receptor (neurokinin A receptor, NK1R) were altered. The mice were exposed to CS (100 mg TPM/m3 in the first wk and 250 mg for the following wks) or filtered air for 16 wks. After exposure, pulmonary MMP- 2, 9, and 12 were detected by RT-PCR and the activity of MMP-2 and-9 was assessed by zymography, IL-1β was measured by ELISA, and SP and NK1R were analyzed by EIA and RT-PCR, respectively. We found that CS-induced emphysema was associated with pulmonary inflammation characterized by infiltrates of macrophages, neutrophils and lymphocytes. CS also significantly upregulated: (a) SP level and expression of NK1 mRNA; (b) MMP2, 9 and 12 mRNA expressions and MMP-2 and -9 enzymatic activity; and (c) IL-1β in lung tissues. Our data confirm the pulmonary inflammation and suggest that the observed elevation of MMPs, IL-1β, SP and NK1R may be involved in pathogenesis of emphysema in this model. (Supported by ALA CI-016N and NIH 74183)