Biomedical subjects

N Hara

Publications and source records attributed to N Hara.

At least 163 records · Page 9Linked to original sources

PubMed1997

Characterization of nociceptin hyperalgesia and allodynia in conscious mice.

1. Intrathecal (i.t.) administration of nociceptin and high doses of morphine induced allodynia in response to innocuous tactile stimuli, and i.t. nociceptin evoked hyperalgesia in response to noxious thermal stimuli in conscious mice. Here we have characterized the nociceptin-induced allodynia and compared it with the morphine-induced allodynia and the nociceptin-evoked hyperalgesia. 2. Nociceptin-induced allodynia was evoked by the first stimulus 5 min after i.t. injection, reached a maximum at 10 min, and continued for a 50 min experimental period. Dose-dependency of the allodynia showed a bell-shaped pattern from 50 pg to 5 ng kg-1, and the maximum effect was observed at 2.5 ng kg-1. 3. Morphine-induced allodynia reached the maximum effect at 15 min and declined progressively until cessation by 40-50 min. The dose-response curve showed a bell-shaped pattern, similar to that induced by nociceptin, with a maximum effect at 0.5 mg kg-1, five orders of magnitude higher than that of nociceptin. 4. The allodynia evoked by nociceptin and morphine were dose-dependently blocked by glycine, D(-)-2-amino-5-phosphonovaleric acid (D-AP5, an N-methyl-D-aspartate (NMDA) receptor antagonist), gamma-D-glutamylaminomethyl sulphonic acid (GAMS, a non-NMDA receptor antagonist) and methylene blue (a soluble guanylate cyclase inhibitor), but were not affected by muscimol (a gamma-aminobutyric acidA (GABAA) receptor agonist) and baclofen (a GABAB receptor agonist). 5. Morphine did not inhibit forskolin-stimulated cyclicAMP formation in cultured cells expressing the nociceptin receptor. 6. Nociceptin-induced hyperalgesia was evoked 10-15 min after i.t. injection. Nociceptin produced a monophasic hyperalgesic action over a wide range of doses from 5 fg to 50 ng kg-1. The nociceptin-induced hyperalgesia was blocked by glycine only among the agents examined. 7. None of the pain responses evoked by nociceptin and morphine were blocked by naloxone. 8. These results demonstrate that, whereas the mechanisms of the nociceptin-induced allodynia and hyperalgesia are evidently distinct, they involve a common neurochemical event beginning with the disinhibition of the inhibitory glycinergic response. Morphine may induce allodynia through a pathway common to nociceptin, but the nociceptin receptor does not mediate the action of high doses of morphine.

Animals↗

PubMed1997

Phase II trial of dose intensification with cisplatin and carboplatin plus vindesine in patients with inoperable non-small cell lung cancer.

We conducted a phase II trial of a regimen that combined cisplatin (CDDP), carboplatin (CBDCA), and vindesine (VDS) in previously untreated patients with non-small cell lung cancer (NSCLC) to evaluate the efficacy and safety of the regimen. Thirty-five patients with inoperable NSCLC entered the study. Cisplatin (CDDP 80 mg/m2) was administered on day 1, and CBDCA 100 mg/m2 and VDS 2 mg/m2) were administered on days 2, 3, and 8. We observed one complete response (CR) and 16 partial responses (PR), with a total response rate of 49% [95% confidence interval (CI) 31-66%]. The overall median survival was 58 weeks; the 1-year survival rate was 60%, and the 2-year survival rate was 23%. Major toxicities were hematologic; leukopenia of grades 3 and 4 occurred in 66% patients, and thrombocytopenia occurred in 23%. Therefore, the dose-intensified regimen of CDDP, CBDCA, and VDS was active in treating patients with inoperable NSCLC, with demonstration of a favorable median survival time.

Adult↗

PubMed1997

Effect of CPT-11 in combination with other anticancer agents in lung cancer cells.

To determine the optimal combination of commonly used anticancer agents with 7-ethyl-10-hydroxy-camptothecin (SN-38), an active metabolite of 7-ethyl-10-[4(1-piperidino)-1-piperidino] carbonyloxy camptothecin (CPT-11), for chemotherapy of lung cancer, we studied the effects of SN-38 in combination with six representative anticancer agents on the human small cell lung cancer (SCLC) cell line, NCl N417, and the non-small cell lung cancer (NSCLC) cell line, PC-9. The anticancer activity was evaluated by MTT assay and the effects of drug combinations on ID50 were analyzed by an improved isobologram method. In the SCLC cell line, supra-additive effect was observed for SN-38 in combination with cisplatin, etoposide (VP-16) and paclitaxel (Taxol). An additive effect was observed for its combination with bleomycin. Sub-additive and protective effects were found in combination with adriamycin (ADR) and 5-fluorouracil (5-FU). In the NSCLC cell line, supra-additive and marginal supra-additive effects were found for SN-38 in combination with VP-16, ADR, 5-FU and bleomycin. The others showed additive effects with SN-38. No drug showed sub-additive and protective effects with SN-38. These results suggest that all the drugs we selected can be used with SN-38 simultaneously for NSCLC, while for SCLC, cisplatin, VP-16 and Taxol are the most suitable for combination with SN-38.

Adenocarcinoma↗

PubMed1997

The effects of a specific tachykinin receptor antagonist FK-224 on ozone-induced airway hyperresponsiveness and inflammation.

We have demonstrated previously that tachykinin depletion by capsaicin prevented the ozone-induced airway hyperresponsiveness and the bronchial wall oedema in guinea pigs. To further clarify the role of neurogenic inflammation in ozone-induced airway hyperresponsiveness, we investigated the effects of a specific tachykinin receptor antagonist (FK-224) in guinea pigs. Animals were anaesthetized, tracheostomized and mechanically ventilated. Total pulmonary resistance (RL) was calculated from transpulmonary pressure and box flow in a plethysmograph. Airway responsiveness was assessed by determining the provocative concentration of histamine aerosol that increased RL to twice the baseline value (PC200). Animals were injected with either FK-224 (10 mg/kg, dissolved in 0.2 mL/kg DMSO) or vehicle (0.2 mL/kg DMSO) intravenously, then pre-ozone PC200 was determined. Following this measurement, animals were exposed to 3 ppm ozone for 60 min. Immediately after exposure, the histamine dose response curve was evaluated again. Bronchoalveolar lavage (BAL) was performed in animals treated with FK-224 or vehicle. In animals treated with vehicle, ozone exposure caused significant decrease in PC200 and moderate increase in neutrophils in BAL fluid. FK-224 pre-treatment significantly inhibited ozone-induced hyperresponsiveness. Neutrophils in BAL fluid did not significantly increase after ozone exposure in animals treated with FK-224. By contrast, the degree of epithelial desquamation did not differ significantly between the two groups. We conclude that neurogenic inflammation caused by tachykinin release may be responsible for ozone-induced bronchial hyperresponsiveness, and that tachykinins may play a role in the initiation of airway inflammation.

Airway Resistance↗

PubMed1997

Nitric oxide derived from sympathetic nerves regulates airway responsiveness to histamine in guinea pigs.

Nitric oxide (NO), which can be derived from the nervous system or the epithelium of the airway, may modulate airway responsiveness. We investigated how NO derived from the airway nervous system would affect the airway responsiveness to histamine and acetylcholine in mechanically ventilated guinea pigs. An NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) (1 mmol/kg i.p.) significantly enhanced airway responsiveness to histamine but not to acetylcholine. Its enantiomer D-NAME (1 mmol/kg i.p.), in contrast, had no effect. The L-NAME-induced airway hyperresponsiveness was still observed in animals pretreated with propranolol (1 mg/kg i.v.) and atropine (1 mg/kg i.v.). Pretreatment with the ganglionic blocker hexamethonium (2 mg/kg i.v.) completely abolished enhancing effect of L-NAME on airway responsiveness. Bilateral cervical vagotomy did not alter the L-NAME-induced airway hyperresponsiveness, whereas sympathetic stellatectomy completely abolished it. Results suggest that NO that was presumably derived from the sympathetic nervous system regulates airway responsiveness to histamine in guinea pigs.

Airway Resistance↗

PubMed1997

Pre- and post-junctional effects of VIP-like peptides in guinea pig tracheal smooth muscle.

To determine the role of VIP-like peptides on neurotransmission of vagus nerve, we evaluated the effects of helodermin, helospectin, and vasoactive intestinal peptide (VIP) on the contraction of guinea pig tracheal smooth muscle evoked by electrical field stimulation (EFS) or the exogenous application of actylcholine (ACh). Isometric tension of tracheal strips was measured in the presence of indomethacin (10(-6) M) and of guanethidine (10(-6) M). VIP (10(-9) M to 10(-7) M) significantly suppressed the contraction evoked by EFS. VIP, at concentrations of 10(-9) M and 10(-8) M, did not affect the ACh-evoked contraction, but a concentration of 10(-7) M suppressed ACh-evoked contraction. Helospectin and helodermin (10(-8) M and 10(-7) M) significantly suppressed the EFS-evoked contraction, but 10(-9) M showed no effect. Helospectin and helodermin had no effect on the ACh sensitivity of smooth muscle up to 10(-8) M, but a concentration of 10(-7) M suppressed the ACh-evoked contraction. These results indicate that helodermin, helospectin, and VIP exert both pre- and post-junctional inhibitory effects on the airway smooth muscle of guinea pigs. These peptides, thus, inhibited tracheal smooth muscle contraction prejunctionally at low concentrations, and acted postjunctionally at higher concentrations.

Acetylcholine↗

PubMed1997

Inhibition by erythromycin of human pulmonary artery endothelial cell injury induced by human neutrophils.

Neutrophils are thought to play a key role in tissue injury. We investigated the role of human neutrophils in the induction of injury to the human pulmonary artery endothelial cells and the effect of erythromycin on neutrophil-induced endothelial cell damage. Incubation of unstimulated neutrophils with endothelial cells increased the release of lactate dehydrogenase (LDH) activity and preloaded fura-2 from endothelial cells. When neutrophils were activated by phorbol myristate acetate, the release of LDH and fura-2 was enhanced further. Superoxide dismutase partially inhibited the release of LDH and fura-2 induced by neutrophils, whereas erythromycin markedly inhibited the release of endothelial cell LDH and fura-2 induced by neutrophils. These results suggest that endothelial cell injury is, at least in part, mediated by the action of superoxide and that erythromycin protects against neutrophil-induced endothelial cell injury.

Anti-Bacterial Agents↗

PubMed1997

Aspergillus fumigatus Asp fI DNA is prevalent in sputum from patients with coal workers' pneumoconiosis.

Aspergillus fumigatus is an apportunistic nosocomial pathogen in immunosuppressed patients or in the lesion where the local defense mechanism was impaired. Patients with pneumoconiosis are known to be susceptible to chronic necrotizing pulmonary aspergillosis. Therefore, we hypothesized that A. fumigatus might be prevalent in sputum from patients with coal workers' pneumoconiosis, and also that asthmatic symptoms in patients with coal workers' pneumoconiosis may be associated with the presence of A. fumigatus. We tested for A. fumigatus in the sputum from patients with coal workers' pneumoconiosis by nested polymerase chain reaction amplification of the Asp fI gene. Sequences specific for this gene were detectable in 5 of 11 (45.5%) patients with coal workers' pneumoconiosis with asthmatic symptoms (group A), 5 of 10 (50.0%) patients with coal workers' pneumoconiosis without asthmatic symptoms (group B) and only 1 of 9 (11.1%) patients with chronic airflow obstruction without pneumoconiosis (group C). The frequency of the Asp fI gene detection was significantly higher in groups A and B than in group C (p < 0.05). The prevalence of A. fumigatus was not associated with asthmatic symptoms. These results demonstrated that A. fumigatus was prevalent in patients with coal workers' pneumoconiosis. We speculate that colonization with A. fumigatus may be associated with this disease.

Aged↗

PubMed1997

The role of neutrophil elastase in human pulmonary artery endothelial cell injury.

Neutrophils are thought to play a key role in tissue injury. We investigated the role of human neutrophil-derived elastase in the induction of injury to human pulmonary artery endothelial cells. Incubation of endothelial cells with neutrophils increased the release of lactate dehydrogenase activity, thrombomodulin, and preloaded fura-2 from endothelial cells, indicating that neutrophils induce endothelial cell injury. Attachment alone of neutrophils to endothelial cells appeared to induce activation because elastase release and N-formyl-mentionyl-leucyl-phenylalanine (fMLP)-induced superoxide (O2) production from neutrophils incubated with endothelial cells were greater than from neutrophils only. When endothelial cell were incubated with neutrophils stimulated by fMLP or phorbol myristate acetate, the amount of elastase in the medium and endothelial cell damage was further enhanced. However, when neutrophils were blocked from direct attachment to endothelial cells using a membrane filter, endothelial cell damage was ameliorated, while exogenous neutrophil elastase and medium containing neutrophil-released elastase did not induce endothelial cell injury. An inhibitor of neutrophil elastase, ONO-5046 Na, as well as erythromycin, which reduces neutrophil-derived elastase, dramatically inhibited neutrophil-induced endothelial cell injury. Superoxide dismutase (SOD) partially inhibited injury. Injury was completely inhibited by treatment with a combination of ONO-5046 Na and SOD. These results suggest that attachment of neutrophils to endothelial cells is important for endothelial cell damage and that neutrophil-derived elastase plays an important role in endothelial cell injury in combination with O2. In addition, ONO-5046 Na and erythromycin may be useful in treating diseases worsened by excessive neutrophil activity.

Endothelium, Vascular↗

PubMed1997

Neutrophil-induced endothelial cell damage: inhibition by a 14-membered ring macrolide through the action of nitric oxide.

Macrolide antibiotics have been used worldwide for about 40 years. The clinical effectiveness of oral erythromycin for diffuse panbronchiolitis has been established and erythromycin seems to act not only as an antibacterial but also as an anti-inflammatory agent. We investigated the effect of 14-membered ring macrolides, erythromycin and clarithromycin, on human neutrophil functions and endothelial cell damage induced by neutrophils. The superoxide production of neutrophils and Ca2+ influx into neutrophils induced by N-formyl-methionyl-leucyl-phenylalanine was inhibited by treatment with erythromycin but not by treatment with clarithromycin. When endothelial cells were cocultured with neutrophils, nitric oxide (NO) presumably released from endothelial cells were enhanced by treatment with erythromycin but not by treatment with clarithromycin and endothelial cell injury induced by neutrophils was ameliorated by addition of erythromycin but not by clarithromycin. The reduction of neutrophil-induced endothelial cell injury by erythromycin was abolished by treatment with carboxy-PTIO which traps NO in the medium. Moreover, nitrite in the medium in which endothelial cells were incubated with neutrophils was enhanced by treatment with erythromycin and the enhancement of nitrite by erythromycin was partially cancelled by addition of H-89, an inhibitor of cyclic AMP-dependent protein kinase (PKA). Erythromycin seems to ameliorate neutrophil-induced endothelial cell injury by affecting not only neutrophil functions but the release of NO from endothelial cells through the action of PKA. The usefulness for the treatment of diseases worsened by the interaction between neutrophils and endothelium might be different among 14-membered ring macrolides.

Anti-Bacterial Agents↗

PubMed1997

The role of nitric oxide in human pulmonary artery endothelial cell injury mediated by neutrophils.

Human endothelial cells are injured by the action of leukocytes. We investigated the role of nitric oxide (NO) in the induction of injury to human pulmonary artery endothelial cells. NO has been a putative source of cytotoxic reactive oxygen species in some settings. Incubation of endothelial cells with neutrophils increased the release of lactate dehydrogenase activity and preloaded fura-2 from endothelial cells, indicating that neutrophils induce endothelial cell injury. This effect was augmented by treatment with carboxy-PTIO, which traps NO in the medium, or with L-NAME, an inhibitor of NO synthase. When endothelial cells were incubated with neutrophils stimulated by phorbol myristate acetate, an activator of protein kinase C, endothelial cell damage was further enhanced and the amount of NO in the medium was decreased. Dibutyryl cyclic AMP, a cell-permeable analogue of cyclic AMP, protected against neutrophil-induced endothelial cell injury and increased NO release into the medium. The effects of dibutyryl cyclic AMP were abrogated by treatment with H-89, a potent inhibitor of cyclic AMP-dependent protein kinase. The protective effect on neutrophil-induced endothelial cell injury by dibutyryl cyclic AMP was abolished by addition of carboxy-PTIO or L-NAME. Thus, our studies suggest that NO, presumably released from endothelial cells, protects against endothelial injury by activated neutrophils and the protective effect by cyclic AMP during coculture with activated neutrophils is mediated through the action of NO. However, when monocytes activated by lipopolysaccharide and IFN-gamma were used instead of neutrophils, endothelial cells were likewise injured, but a much higher level of NO was detected and injury was diminished by addition of carboxy-PTIO to the medium. These observations suggest that the high levels of NO released by activated monocytes contribute to endothelial injury, whereas low levels of NO protect endothelial cells against injury by neutrophils.

Benzoates↗

PubMed1997

Effect of beta 2-agonists on histamine-induced airway microvascular leakage in ozone-exposed guinea pigs.

beta 2-adrenergic agonists exhibit antipermeability effects in the airways. However, it is not known whether beta 2-agonists have this beneficial effect in airway mucosa that is already inflamed. We evaluated the effects of two inhaled beta 2-agonists, salbutamol and formoterol, on the histamine-induced bronchoconstriction and plasma extravasation in the airways of guinea pigs with or without ozone exposure. Total pulmonary resistance (RL) was measured before and after histamine inhalation in anesthetized animals that were pretreated with inhaled salbutamol, formoterol, or saline. Plasma extravasation in the airways was measured using Evans blue dye. In the control animals not exposed to ozone, salbutamol and formoterol each significantly reduced both the histamine-induced bronchoconstriction and the plasma extravasation in the trachea and main bronchi. In the ozone-exposed animals, the increase in RL after histamine was greater than that in control animals. Salbutamol and formoterol each significantly reduced histamine-induced bronchoconstriction, even in the ozone-exposed animals. Salbutamol did not affect the histamine-induced plasma extravasation, whereas formoterol reduced the plasma extravasation in the main bronchi, but not in the trachea, of the animals exposed to ozone. These results suggest that the anti-inflammatory properties of formoterol in inflamed airways may contribute to the beneficial effects in the treatment of airway inflammation.

Adrenergic beta-Agonists↗

PubMed1997

Apoptosis and expression of Fas/Fas ligand mRNA in bleomycin-induced pulmonary fibrosis in mice.

The incidence of apoptosis and the expression of Fas antigen (Fas)/Fas ligand (FasL) mRNA in bleomycin-induced pulmonary fibrosis in mice were examined. Male ICR mice were intratracheally instilled with bleomycin (5 U/kg of body weight). The controls were injected with sterile saline. The animals were anesthetized and killed at 1, 6, and 12 h, and 1, 3, 5, 7, 9, and 14 days after bleomycin instillation. We assessed the incidence of apoptosis in lung tissues by DNA fragmentation on agarose gel electrophoresis, terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end-labeling, and electron microscopy. The expression of Fas and FasL mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR). The localization of Fas mRNA was analyzed by in situ hybridization and that of FasL mRNA was analyzed by RT in situ PCR. The results showed that (1) a single instillation of bleomycin leads to the rapid appearance of apoptosis in bronchial and alveolar epithelial cells, which resolves within 1 day, and (2) apoptosis reappears on day 7 and continues for over 14 days after bleomycin instillation. This was accompanied with a progression of fibrosis. Corticosteroid administration completely blocked both apoptosis and fibrosis. The expression of Fas mRNA was upregulated in the alveolar epithelial cells by the bleomycin instillation. FasL mRNA was also upregulated in infiltrating lymphocytes after bleomycin treatment, but not in the control mice. The administration of corticosteroids suppressed the expression of Fas and FasL mRNA as well as apoptosis and fibrosis. Although these results do not show that apoptosis mediated by the Fas/FasL system is directly linked to bleomycin-induced fibrosis, we speculate that excessive apoptosis and the Fas/FasL system play a role in the pathogenesis of bleomycin-induced lung injury.

Animals↗

PubMed1997

Induction of apoptosis and pulmonary fibrosis in mice in response to ligation of Fas antigen.

Fas antigen is a cell surface protein that mediates apoptosis, and it is expressed in various cells and tissues. Fas ligand binds to its receptor Fas, thus inducing apoptosis of Fas-bearing cells. Malfunction of the Fas-Fas ligand system causes lymphoproliferative disorders and autoimmune diseases, whereas its exacerbation may cause tissue destruction. We hypothesize that excessive apoptosis mediated by Fas-Fas ligand interaction may damage alveolar epithelial cells and result in pulmonary fibrosis. Mice were allowed to inhale repeatedly an aerosolized anti-Fas antibody for 14 days. The nuclei of bronchial and alveolar epithelial cells were positively stained by in situ DNA nick end labeling. Electron microscopy demonstrated apoptotic changes in bronchial and alveolar epithelial cells. Histologic findings and hydroxyproline content showed the development of pulmonary fibrosis, which was dependent on the dose of anti-Fas antibody. The repeated inhalation of control antibody (isotype-matched control hamster IgG) did not induce apoptosis of epithelial cells or pulmonary fibrosis. The expression of TGF-beta mRNA was upregulated from day 7 to day 28 in lung tissues of anti-Fas antibody-treated mice but not in those of control mice. In this report, we present the evidence that repeated inhalation of anti-Fas antibody mimicking Fas-Fas ligand crosslinking induces excessive apoptosis and inflammation, which results in pulmonary fibrosis in mice.

Animals↗

PubMed1997

L-NAME-sensitive and -insensitive nonadrenergic noncholinergic relaxation of cat airway in vivo and in vitro.

The neurotransmitters responsible for neurogenic airway relaxation are still unknown. We investigated the effects of N omega-nitro-L-arginine methylester (L-NAME) on nonadrenergic and noncholinergic (NANC) relaxation evoked by electrical stimulation of vagus nerves in vivo and in vitro in cat. To that end, we measured pulmonary resistance during vagal nerve stimulation (VS) in vivo, and isometric tension of small bronchi (1-3 mm outer diameter) during electrical field stimulation (EFS) in vitro. During infusion of 5-hydroxytryptamine (5-HT), VS transiently decreased total pulmonary resistance in the presence of atropine and propranolol, with peak relaxation at several seconds after the VS and a gradual return to baseline within 2-3 min. L-NAME abolished the initial peak relaxation and reduced the peak amplitude, but did not affect the duration of the NANC relaxation. In small bronchi obtained from control cats, EFS evoked a biphasic NANC relaxation, comprising an initial fast component followed by a second slow component, and L-NAME (10(-5) M) selectively abolished the first component without affecting the second. Whilst in the small bronchi obtained from L-NAME pretreated cats, EFS elicited only the slow component of NANC relaxation, which was insensitive to L-NAME but sensitive to tetrodotoxin. These results indicate that nonadrenergic noncholinergic relaxation induced by vagal nerve stimulation during infusion of 5-hydroxytryptamine can be classified into two components, and that at least two neurotransmitters, including nitric oxide, are involved in the relaxation.

Airway Resistance↗

PubMed1997

Detection of adenovirus E1A DNA in pulmonary fibrosis using nested polymerase chain reaction.

The history of patients with idiopathic pulmonary fibrosis (IPF) shows that the disease may be preceded by a viral-like illness. Although viruses have not been demonstrated, it is possible that viruses were not detected in culture because they do not replicate during latency. We investigated the presence of adenovirus in IPF and interstitial pneumonia associated with collagen vascular disease (CVD-IP), using the nested polymerase chain reaction (PCR) and in situ hybridization (ISH) for the E1A region of the adenovirus genome. Studies were performed on lung tissues obtained by transbronchial lung biopsy from 19 patients with IPF, 10 patients with CVD-IP and, for comparison, from 20 patients with sarcoidosis. The E1A DNA was present in 3 out of 19 (16%) cases of IPF, in 5 of 10 (50%) cases of CVD-IP, and in 2 of 20 (10%) cases of sarcoidosis. The incidence of E1A DNA in CVD-IP was significantly higher than that in sarcoidosis (p<0.05). In patients with IPF and CVD-IP, E1A DNA was more prevalent in patients treated with corticosteroids (6 out of 9 cases; 67%) than in those without it (2 out of 20 cases; 10%) (p<0.01). ISH studies showed that 1 out of 8 cases of IPF and CVD-IP, in which E1A DNA was detected by PCR, was positive for E1A DNA. We conclude that adenovirus E1A is unlikely to be aetiologically involved in the pathogenesis of idiopathic pulmonary fibrosis or interstitial pneumonia associated with collagen vascular disease. However, a latent adenovirus infection may be reactivated or may newly infect the host following corticosteroid administration.

Adenovirus Infections, Human↗

PubMed1997

Apoptosis and Fas/Fas ligand mRNA expression in acute immune complex alveolitis in mice.

Deoxyribonucleic acid (DNA) strand breaks as a characteristic of apoptosis, and Fas antigen (Fas)/Fas ligand (FasL) expression may participate in acute immune complex alveolitis in mice. Male Institute for Cancer Research (ICR) mice were injected intravenously with immunoglobulin G (IgG) antibodies against ovalbumin and inhaled an aerosolized oval albumin (OA) solution. They were killed at 4, 6, 12, 24, 48 h and 7 days after aerosolization. We assessed DNA fragmentation by agarose gel electrophoresis and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick end-labelling (TUNEL). The expression of Fas and FasL messenger ribonucleic acid (mRNA) in lung tissues was assessed by reverse transcriptase (RT) polymerase chain reaction, and by in situ hybridization (ISH) to localize Fas mRNA, and RT in situ polymerase chain reaction to localize FasL mRNA. The fragmentation of DNA extracted from lung tissue was found 6-24 h after OA inhalation. TUNEL detected positive signals in bronchial and alveolar epithelial, endothelial and inflammatory cells in the lung tissue. These positive signals had disappeared 7 days after OA inhalation. TUNEL also detected positive signals in apoptotic neutrophils in bronchoalveolar lavage fluid at 6-12 h. Fas mRNA was expressed in the alveolar epithelial and inflammatory cells, while the expression of FasL mRNA appeared to be upregulated in infiltrating inflammatory cells at 6-24 h. These results suggest that apoptosis may be associated with the resolution of inflammation and with tissue repair and also suggest the involvement of the Fas antigen/Fas ligand pathway in acute immune complex alveolitis in mice.

Acute Disease↗

PubMed1997

P53 and p21 (Waf1/Cip1) mRNA expression associated with DNA damage and repair in acute immune complex alveolitis in mice.

The tumor suppresser p53 is a cell cycle checkpoint protein that contributes to the preservation of genetic stability by mediating either a G1 arrest or apoptosis in response to DNA damage. p53 causes growth arrest through transcriptional activation of the cyclin-dependent kinase inhibitor p21. During p53-mediated suppression of cell proliferation, p21 is important for coordinating cell cycle progression, DNA replication, and repair of damaged DNA. The purpose of this study is to investigate the expression of p53 and p21 mRNA in association with DNA damage and normal repair in acute immune complex alveolitis in mice. Male ICR mice were injected intravenously with IgG antibodies against oval albumin, aerosolized with oval albumin solution, and killed at 4, 6, 12, 24, and 48 hours and 1 week after aerosolization. We assessed the expression of p53 and p21 mRNA by reverse transcriptase (RT)-PCR and by RT in situ PCR. We also assessed DNA damage by terminal deoxynucleotidyl transferase mediated biotin-dUTP nick-end-labeling (TUNEL) and by gel electrophoresis of DNA extracted from lung tissues. The results of RT-PCR and RT in situ PCR showed that p53 and p21 mRNA were concurrently up-regulated at 4 to 48 hours after aerosolization in alveolar epithelial cells. Bronchial and alveolar epithelial cells were positively stained by TUNEL in this period but not at 1 week after aerosolization or in control mice. The result of electrophoretic analysis of DNA was compatible with that of TUNEL. These studies suggest that the responses of p53 and p21 mRNA are associated with physiologic processes of DNA damage and repair in acute immune complex alveolitis in mice.

Animals↗