Probable progressive multifocal leukoencephalopathy-immune reconstitution inflammatory syndrome with immunosuppressant dose reduction following lung transplantation: a case report and literature review.

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) is a rapidly developing demyelinating disease in the cerebral white matter and is often caused by JC polyomavirus (JCV). PML after lung transplantation is rare and has a poor prognosis, with no established therapies. Reducing the patient's immunosuppressant doses, thereby restoring immunity, could be used to treat PML. However, some patients develop immune reconstitution inflammatory syndrome (IRIS) with this treatment, an immune-induced inflammatory response to JCV that results in serious neuronal damage. We herein report a case of a 60-year-old female who suffered from PML 5 years after lung transplantation, had worsened brain lesions thought to be related to PML-IRIS at the time of immunosuppressant reduction, and missed treatment opportunities. CASE PRESENTATION: A 60-year-old female developed PML 5 years after lung transplantation. Fluid-attenuated inversion recovery and diffusion-weighted brain magnetic resonance imaging (MRI) revealed multiple high-signal lesions, mainly in the cerebral white matter. Polymerase chain reaction found 0.32 million copies/mL of JCV in the cerebrospinal fluid. Thus, she was given a diagnosis of PML. Mycophenolate mofetil and tacrolimus dosages were reduced, and CD4-positive cell counts and the blood concentration of each immunosuppressant were monitored. Mefloquine was also orally administered at a daily dose of 275 mg for 3 days and was then administered at a dose of 275 mg per week. Although the patient's CD4-positive cell counts increased and her immune system recovered, her symptoms and brain MRI findings worsened. We suspected PML progression or a transition to PML-IRIS. Steroid pulse therapy to suppress the inflammatory lesions was not possible but was retrospectively indicated. The patient rapidly began to exhibit akinetic mutism and died 4 months after the onset of neurologic symptoms. CONCLUSIONS: When neurologic symptoms and abnormal brain MRI findings are noted during immune recovery, it is often difficult to distinguish between progressed PML and PML-IRIS. However, the pathogenesis of brain lesions usually involves inflammation and immune-reactive mechanisms for JCV. Steroid pulse therapy, which can reduce inflammation, should thus be administered in organ transplantation cases with differential diagnoses including PML-IRIS.

Paraneoplastic limbic encephalitis with late-onset magnetic resonance imaging findings: A case report.

Paraneoplastic limbic encephalitis (PLE), a paraneoplastic neurological syndrome (PNS), is a rare nervous system disorder that results from the indirect effects of tumors and is commonly associated with small-cell lung cancer (SCLC). Previous studies have reported that magnetic resonance imaging (MRI) may be useful for diagnosing LE. Temporal lobe abnormalities are observed using T2-weighted and fluid-attenuated inversion recovery sequences; however, such abnormalities are detected in only 60% of patients with PLE. The present study describes a case of PLE associated with SCLC, in which LE was observed using MRI 26 days after the first convulsive seizure. Although the serum and cerebrospinal fluid analyses for onconeural antibodies were negative, the findings of this case indicate that PLE should be considered in the differential diagnosis, and that repeated brain MRI may be more helpful for diagnosis, as the brain MRI findings may be normal during the early stages of PLE.

S-1-containing chemotherapy for patients with non-small-cell lung cancer: A population-based observational study by the Ibaraki thoracic integrative (POSITIVE) research group.

To evaluate the efficacy and safety of S-1 monotherapy, S-1-containing combined chemotherapy and S-1 containing chemoradiotherapy for non-small cell lung cancer (NSCLC), a population-based observational study was performed. The efficacy and safety of the chemotherapies were evaluated at 13 institutes in a prefecture of Japan between April 2011 and March 2015. Datasets were obtained from 282 patients with NSCLC. For either wild-type or mutated epidermal growth factor receptor (EGFR), these three therapy groups generated almost identical response results and toxicity profiles as those in previously reported clinical trials, although the present study appeared to have slightly lower survival rates compared with those in the previous clinical trials. This may be due to the inclusion of patients in poor condition, and S-1 therapy being administered in the second, or later, line of therapy. In conclusion, the present study has confirmed that S-1-containing chemotherapy is effective against wild- and mutated-type EGFR NSCLC, and it is also tolerable in clinical practice.

Efficacy of first-line erlotinib in non-small cell lung cancer patients undergoing dose reduction and those with a low body surface area: A population-based observational study by the Ibaraki Thoracic Integrative (POSITIVE) Research Group.

The aim of the present study was to evaluate the efficacy of erlotinib, one of the epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), in patients undergoing dose reduction and in those with a low body surface area (BSA). The association between dose reduction, low BSA and efficacy, including response rate, disease control rate, time to treatment failure and overall survival, were evaluated in patients prescribed first-line erlotinib for EGFR mutated non-small cell lung cancer patients between April 2012 and March 2015. A total of 22 patients received first-line erlotinib during the study period. A dose reduction of erlotinib for the reason of low BSA and poor performance status occurred in 14 (63.6%) of the patients: 6 (27.3%) had initial dose reduction, 6 (27.3%) had dose reduction in their clinical courses, and 2 (9.1%) had both. Dose reduction of erlotinib with the initial dose of erlotinib/BSA was >80 mg/m2, and longest-term prescribed dose of erlotinib/BSA was >50 mg/m2, which may have no association with a survival disadvantage. Dose-reduction estimation studies for TKIs may be crucial, particularly for patients with a low BSA. Future prospective studies and confirmation of these results in population-based retrospective ones investigating the incidence of dose reduction in patients with AEs and those with low BSA may be required for the efficient use of erlotinib in common clinical practice.

Lung cancer with spontaneous regression of primary and metastatic sites: A case report.

Partial or complete spontaneous cancer regression is a rare phenomenon, particularly in patients with lung cancer. This is the case report of a patient with lung cancer who exhibited spontaneous regression of the primary as well as metastatic lesions, without receiving any treatment. Spontaneous regression commenced within a week of obtaining pathological specimens by transbronchial and percutaneous biopsies from the primary lesion and metastatic lymph nodes of the left side of the neck. The reason for this phenomenon is unknown; however, we hypothesized that there may be an immunological association between the stimulus of the biopsies and the spontaneous regression. This patient should be closely followed up to monitor the clinical course of this unusual case.

Efficacy of tyrosine kinase inhibitors in non-small-cell lung cancer patients undergoing dose reduction and those with a low body surface area.

The objective of this study was to evaluate the efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) in patients undergoing dose reduction and in those with a low body surface area (BSA). The association between dose reduction, low BSA and efficacy, including response rate (RR), disease control rate (DCR), progression-free survival (PFS) and overall survival (OS), were evaluated in patients prescribed TKIs between September, 2002 and May, 2013. A total of 282 patients received EGFR-TKIs during the study period, 53 (18.8%) of whom underwent a dose reduction (21.4 and 31.6% of the patients with a BSA of <1.5 and <1.25 m2, respectively). Eleven (20.8%) of these 53 patients had a dose reduction due to adverse events (AEs) >grade 3. In either gefitinib or erlotinib treatment, the RR, DCR, PFS and OS in EGFR-mutated patients with a BSA of <1.5 m2 were not different from those in patients with a BSA of >1.5 m2. In addition, there were no differences in these parameters between patients with and those without a dose reduction of TKIs. The dose of TKIs in patients with AEs and in those with low BSA should be determined with caution. To confirm the equal efficacy of TKIs in patients undergoing a dose reduction, prospective observational studies with less patient heterogeneity are required.

High-dose concurrent chemo-proton therapy for Stage III NSCLC: preliminary results of a Phase II study.

The aim of this report is to present the preliminary results of a Phase II study of high-dose (74 Gy RBE) proton beam therapy (PBT) with concurrent chemotherapy for unresectable locally advanced non-small-cell lung cancer (NSCLC). Patients were treated with PBT and chemotherapy with monthly cisplatin (on Day 1) and vinorelbine (on Days 1 and 8). The treatment doses were 74 Gy RBE for the primary site and 66 Gy RBE for the lymph nodes without elective lymph nodes. Adapted planning was made during the treatment. A total of 15 patients with Stage III NSCLC (IIIA: 4, IIIB: 11) were evaluated in this study. The median follow-up period was 21.7 months. None of the patients experienced Grade 4 or 5 non-hematologic toxicities. Acute pneumonitis was observed in three patients (Grade 1 in one, and Grade 3 in two), but Grade 3 pneumonitis was considered to be non-proton-related. Grade 3 acute esophagitis and dermatitis were observed in one and two patients, respectively. Severe ( ≥ Grade 3) leukocytopenia, neutropenia and thrombocytopenia were observed in 10 patients, seven patients and one patient, respectively. Late radiation Grades 2 and 3 pneumonitis was observed in one patient each. Six patients (40%) experienced local recurrence at the primary site and were treated with 74 Gy RBE. Disease progression was observed in 11 patients. The mean survival time was 26.7 months. We concluded that high-dose PBT with concurrent chemotherapy is safe to use in the treatment of unresectable Stage III NSCLC.

Brain metastasis as an isolated late recurrence in small-cell lung cancer.

The brain is one of the most common sites of metastasis of small-cell lung cancer (SCLC). In this study, we reported 6 cases with isolated brain relapse of SCLC ≥1 year after the completion of the initial treatment for SCLC. Of the 6 patients, 2 had a solitary brain metastasis and 4 had ≥2 brain metastatic sites. The metastases were identified during a regular check-up computed tomography (CT) scan and were successfully treated. The median interval from the initial diagnosis to the development of brain metastasis was 16 months (range, 13-30 months). All patients received whole-brain irradiation and achieved a complete response. Only one patient developed disturbances of the higher cerebral function. The median interval from whole-brain irradiation to death or last follow-up was 33 months (range, 8-90 months). To the best of our knowledge, these are the first reported cases with isolated brain relapse of SCLC. Although a rare finding, clinicians should be alert on the possibility of such recurrence, particularly in patients who refused prophylactic cranial irradiation.

Outcomes and prognostic factors for recurrence after high-dose proton beam therapy for centrally and peripherally located stage I non--small-cell lung cancer.

INTRODUCTION: This study was conducted to determine disease control rates and prognostic factors associated with recurrence of centrally and peripherally located stage I NSCLC treated using high-dose PBT. PATIENTS AND METHODS: Seventy-four patients with 80 centrally or peripherally located stage I NSCLCs were treated with PBT. A protocol using 72.6 Gy (RBE) in 22 fractions was used for centrally located tumors, and 66 Gy (RBE) in 10 or 12 fractions was used for peripherally located tumors. Data were collected and control rates and prognostic factors for recurrence were evaluated retrospectively. RESULTS: The median follow-up period was 31.0 months. The overall survival, disease-specific survival, and progression-free survival rates were 76.7%, 83.0%, and 58.6% at 3 years, respectively. Disease recurrence was noted in 30 patients and local recurrence of 11 tumors occurred. The 3-year local control rate was 86.2% for stage IA tumors and 67.0% for stage IB tumors. Radiation dose was identified as a significant prognostic factor for disease recurrence and local recurrence. Tumor diameter and age were only significantly associated with disease recurrence. The 3-year local control rate was 63.9% for centrally located tumors irradiated with 72.6 Gy (RBE) and 88.4% for peripherally located tumors irradiated with 66 Gy (RBE). CONCLUSION: Radiation dose was shown to be the most significant prognostic factor for tumor control in stage I NSCLC treated using high-dose PBT. Tumor diameter was not significant for local control. Further evaluation of PBT for centrally located tumors is warranted.

Isolated solitary brain metastasis as a relapse of small cell lung cancer.

The brain is one of the most common sites for the metastasis of small cell lung cancer (SCLC). The present study describes two cases of an isolated solitary brain metastasis as a relapse of SCLC, which occurred more than one year after the completion of the initial successful treatment for SCLC. The tumors were identified during a regular check-up computed tomography (CT) scan and were successfully treated. To the best of our knowledge, this is the first study to report the cases of two patients with an isolated solitary brain metastasis as a relapse of SCLC. Although extremely rare, the possibility of such recurrences should be considered, particularly in patients who have refused prophylactic cranial irradiation.

[Satisfactory outcome with erlotinib after failure with gefitinib in a patient with meningeal carcinomatosis secondary to non-small cell lung cancer].

A 60-year-old man was admitted to our hospital because of the radiologic findings of meningeal carcinomatosis after long-term disease control of epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer, with cisplatin-based chemotherapy followed by gefitinib. Brain magnetic resonance imaging (MRI) revealed diffuse and linear enhancement on the surface of the midbrain and along the cerebellar folia. In addition, analysis of his cerebrospinal fluid (CSF) showed an increased WBC count and an elevated level of CEA. He presented no symptoms at the time of diagnosis of meningeal carcinomatosis; however, within 2 weeks, neurological symptoms such as disorientation, dysarthria, and ataxic gait became apparent. Since his symptoms seemed to worsen even under further treatment with different cisplatin-based chemotherapy or retreatment with gefitinib, we decided to initiate erlotinib treatment. His symptoms rapidly improved within a week of beginning treatment with erlotinib, and MRI and CSF examinations also showed remarkable improvement of the meningeal carcinomatosis. This case suggests that erlotinib may be effective in some patients with meningeal carcinomatosis previously treated with gefitinib. However, further studies are required to understand the differential efficacy of these drugs.

Patients with lung cancer with metachronous or synchronous gastric cancer.

BACKGROUND: There are few reports of treatment and outcome for patients with metachronous or synchronous lung and gastric cancers. To evaluate them, we conducted a retrospective study. PATIENTS AND METHODS: The medical records of patients with lung cancer who previously or simultaneously had gastric cancer seen in our division between January 1979 and July 2008 were reviewed. RESULTS: Forty-five (3.2%) of 1391 patients had previous or simultaneous gastric cancer. The proportion of men was higher among patients with lung cancer with gastric cancer than those without (P = .0006). There was a significant difference in age at the time of diagnosis of lung cancer between the 45 patients with gastric cancer and the 1346 patients without it (P = .0344). The proportion of smokers was higher among lung cancer patients with gastric cancer than those without (P = .0015). Twenty-seven of 45 patients had smoking-related cell types of lung cancer: squamous cell carcinoma and small-cell lung cancer. The proportion of these 2 cell types was higher in patients with lung cancer with gastric cancer than those without (P = .02). The diagnosis of gastric cancer preceded the diagnosis of lung cancer in 33 patients, and the median duration from the diagnosis of gastric cancer to that of the lung cancer was 6 years. CONCLUSION: For patients with gastric cancer, smoking cessation, a chest radiograph at least yearly for several years, and swift evaluation of signs or symptoms that are suggestive of lung cancer should be recommended, especially in elderly men with gastric cancer and smoking habit.

Nrf2 enhances cell proliferation and resistance to anticancer drugs in human lung cancer.

PURPOSE: NF-E2-related factor 2 (Nrf2), a key transcription regulator for antioxidant and detoxification enzymes, is abundantly expressed in cancer cells. In this study, therefore, the role of Nrf2 in cancer cell proliferation and resistance to anticancer drugs was investigated. EXPERIMENTAL DESIGN: We used three human lung cancer cell lines with different degrees of Nrf2 activation: Nrf2 was highly activated in A549 cells, slightly activated in NCI-H292 cells, and not activated in LC-AI cells under unstimulated conditions. RESULT: A549 cells showed higher resistance to cisplatin compared with NCI-H292 and LC-AI cells. The resistance to cisplatin was significantly inhibited in A549 but not in NCI-H292 or LC-AI cells by knockdown of Nrf2 with its specific small interfering RNA (Nrf2-siRNA). The cell proliferation was also most prominently inhibited in A549 cells by treatment with Nrf2-siRNA. In A549 cells, the expression of self-defense genes, such as antioxidant enzymes, phase II detoxifying enzymes, and drug efflux pumps, was significantly reduced by Nrf2-siRNA concomitant with a reduction of the cellular glutathione level. The degree of DNA crosslink and apoptosis after treatment with cisplatin was significantly elevated in A549 cells by Nrf2-siRNA. Knockdown of Nrf2 arrested the cell cycle at G(1) phase with a reduction of the phosphorylated form of retinoblastoma protein in A549 and NCI-H292 cells but not in LC-AI cells. CONCLUSION: These results indicate that the Nrf2 system is essential for both cancer cell proliferation and resistance to anticancer drugs. Thus, Nrf2 might be a potential target to enhance the effect of anticancer drugs.

Overexpression of GATA-3 protects against the development of hypersensitivity pneumonitis.

RATIONALE: Hypersensitivity pneumonitis (HP) is mediated by a Th1 immune response. Transcription factor GATA binding protein-3 (GATA-3) is believed to be a key regulator of Th2 differentiation and thus might play regulatory roles in the pathogenesis of hypersensitivity pneumonitis (HP). OBJECTIVES: We examined the effect of GATA-3 overexpression on the development of HP in mice. METHODS: Wild-type C57BL/6 mice and GATA-3-overexpressing mice of the same background were used in this study. HP was induced by repeated exposure to Saccharopolyspora rectivirgula, the causative antigen of farmer's lung. MEASUREMENTS AND MAIN RESULTS: Antigen exposure resulted in a marked inflammatory response with enhanced pulmonary expression of T-bet and the Th1 cytokine interferon (IFN)-gamma in wild-type mice. The degree of pulmonary inflammation was much less severe in GATA-3-overexpressing mice. The induction of T-bet and IFN-gamma genes was suppressed, but a significant induction of Th2 cytokines, including IL-5 and IL-13, was observed in the lungs of GATA-3-overexpressing mice after antigen exposure. Supplementation with recombinant IFN-gamma enhanced lung inflammatory responses in GATA-3-overexpressing mice to the level of wild-type mice. Because antigen-induced IFN-gamma production predominantly occurred in CD4+ T cells, nude mice were transferred with CD4+ T cells from either wild-type or GATA-3-overexpressing mice and subsequently exposed to antigen. Lung inflammatory responses were significantly lower in nude mice transferred with CD4+ T cells from GATA-3-overexpressing mice than in those with wild-type CD4+ T cells, with a reduction of lung IFN-gamma level. CONCLUSIONS: These results indicate that overexpression of GATA-3 attenuates the development of HP by correcting the Th1-polarizing condition.

Niflumic acid and AG-1478 reduce cigarette smoke-induced mucin synthesis: the role of hCLCA1.

BACKGROUND: Cigarette smoke induces bronchial mucus secretion. However, the mechanism of this induction is still unidentified. In this study, we investigated the role of the putative calcium-activated chloride channel 1 (CLCA1) and its blocker, niflumic acid, in cigarette smoke-induced mucin synthesis both in vivo and in vitro. METHODS AND RESULTS: Sprague-Dawley rats were exposed to cigarette smoke for 4 weeks. The CLCA1, epidermal growth factor receptor (EGFR), and MUC5AC expressions were increased in the trachea and lung tissues. Goblet-cell hyperplasia with marked mucin staining was detected in the tracheal and bronchial epithelium. In the human bronchial epithelial cell line NCI-H292, cigarette smoke solution also induced mucin production as well as the RNA and protein expressions of CLCA1, EGFR, and MUC5AC. Both in vivo and in vitro, the induction of MUC5AC and mucin synthesis were inhibited by niflumic acid, and/or a selective EGFR tyrosine kinase inhibitor, AG-1478. Niflumic acid also blocked the epidermal growth factor-induced MUC5AC and mucin staining in the NCI-H292 cell line. CONCLUSION: Both EGFR and niflumic acid-sensitive chloride channels (probably CLCA1) are dependently affecting the mucin production as a part of a single complex signaling pathway. CLCA1 may be a key signaling member that can be targeted with pharmacologic interventions to treat mucus hypersecretion.

Association of phosphodiesterase 4D gene polymorphisms with chronic obstructive pulmonary disease: relationship to interleukin 13 gene polymorphism.

Activation of the cyclic AMP (cAMP) signaling pathway leads to the suppression of inflammation in the airways and relaxation of airway smooth muscle. Intracellular cAMP levels are determined by a balance between the activities of adenylate cyclase and phosphodiesterases. We hypothesized that polymorphisms of the phosphodiesterase 4D (PDE4D) gene activate its protein function which leads to the downregulation of cAMP, resulting in the development of chronic obstructive pulmonary disease (COPD). A case-control study was performed using Japanese (96 COPD patients and 61 controls) and Egyptians (106 COPD patients and 72 controls) to investigate the association between the polymorphisms of the PDE4D gene and the development of COPD. Genotyping of all subjects for SNP7 (dbSNP ID, rs10075508), SNP13 (rs829259) and SNP15 (rs702531) in exon 15 of the PDE4D gene was conducted. Furthermore, the distributions of haplotypes consisting of PDE4D polymorphisms and those of interleukin (IL) 4, IL13 and beta2 adrenoceptor were analyzed. The distribution of SNP13 allele frequencies of the PDE4D gene was significantly different between the COPD and control groups in the Japanese population (p = 0.041). In haplotype analysis, haplotypes composed of PDE4D SNP7 and IL13 +2044 G/A in the Japanese population showed significant difference between the patients and controls (pcorr = 0.00048). Thus, SNP13 and haplotypes, SNP7 G/A and IL13 +2044 G/A, may be useful for predicting COPD susceptibility.

Overexpression of the transcription factor GATA-3 enhances the development of pulmonary fibrosis.

Recent studies have demonstrated that Th2 cytokines, such as interleukin-4 and interleukin-13, enhance fibrotic processes by activating fibroblast proliferation and collagen production, whereas interferon-gamma, a Th1 cytokine, inhibits these processes. Th1 and Th2 cells both differentiate from common T precursor cells, with transcription factor GATA-3 a key regulator of Th2 differentiation. In the present study, therefore, we examined the effects of GATA-3 overexpression on the development of pulmonary fibrosis in a mouse model. Wild-type C57BL/6 mice and GATA-3-overexpressing (GATA-3-tg) mice of the same background were intratracheally treated with bleomycin. The survival rate after bleomycin was significantly decreased in GATA-3-tg mice compared with wild-type mice. The degree of pulmonary fibrosis was much greater in GATA-3-tg mice than in wild-type mice 28 days after bleomycin treatment. Lung interferon-gamma concentration was significantly decreased in GATA-3-tg mice compared with wild-type mice by 7 days after either saline or bleomycin treatment. The concentration of transforming growth factor-beta, a fibrogenic cytokine, was significantly higher in GATA-3-tg mice than in wild-type mice. Exogenous administration of interferon-gamma to GATA-3-tg mice improved the degree of pulmonary fibrosis and thus increased survival. These results indicate that overexpression of GATA-3 enhances the development of pulmonary fibrosis, possibly by reducing interferon-gamma levels in the lung.

Alternative lengthening of telomeres in the human adrenocortical carcinoma cell line H295R.

Telomere maintenance can occur in the absence of telomerase by a mechanism referred to as alternative lengthening of telomeres (ALT). ALT is considered to be rare in tumors of epithelial origin. The biological significance and molecular mechanism of ALT have not been well studied in human cancers. It has been reported that clinical samples of adrenocortical carcinoma show a low incidence of telomerase positivity. We characterized an adrenocortical carcinoma cell line, H295R, focusing on the telomere maintenance mechanism, and compared it with telomerase-positive 293 cells and HeLa cells. Telomerase activity could not be detected in H295R cells by the TRAP assay. Among the essential components of the telomerase holoenzyme, only hTERT expression was undetectable by RT-PCR, indicating that the lack of telomerase activity is due to suppression of hTERT. H295R cells had long and heterogeneous telomere DNA, and FISH revealed large nuclear bodies in a few interphase nuclei, which presumably represented ALT-associated PML bodies. These results suggest that H295R cells have the ALT phenotype. Several proteins that are possibly associated with the telomere maintenance mechanism were examined. TRF1 and TRF2 were expressed in H295R cells as well as in 293 cells and HeLa cells. The ratio of hnRNP B1 to A2 was higher in H295R cells than in 293 cells and HeLa cells. In conclusion, the H295R adrenocortical carcinoma cell line is negative for telomerase and maintains its telomeres by the ALT mechanism. We anticipate that H295R cells will be a good model for understanding the significance and mechanism of ALT in human cancers.

Transcription factors T-bet and GATA-3 regulate development of airway remodeling.

RATIONALE: Airway remodeling is an important feature of chronic asthma that causes irreversible airflow obstruction. Although asthma is considered to be a Th2 disease, the role of T-bet and GATA-3, the key transcription factors for differentiation toward Th1 and Th2 cells, in the pathogenesis of airway remodeling is poorly understood. OBJECTIVES: We therefore examined the effects of GATA-3 or T-bet induction of Th1/Th2 bias on the development of airway remodeling in mice. METHODS: The development of airway remodeling after repeated allergen challenges was analyzed using transgenic mice overexpressing either GATA-3 or T-bet. MAIN RESULTS: The degrees of subepithelial fibrosis and airway smooth muscle hyperplasia after repeated allergen exposure were significantly enhanced in mice overexpressing GATA-3, compared with wild-type mice. Allergen-induced goblet cell hyperplasia and mucus hypersecretion were significantly lower in mice overexpressing T-bet than in wild-type mice. Eosinophilic airway inflammation increased in mice overexpressing GATA-3, but decreased in mice overexpressing T-bet after repeated allergen exposure. Cytokine analysis revealed that the Th1/Th2 cytokine balance shifted to Th2 in lung homogenates and lung T cells of mice overexpressing GATA-3, whereas this balance shifted to Th1 in those of mice overexpressing T-bet after allergen exposure. Lung transforming growth factor-beta and eotaxin levels were associated with the degree of subepithelial fibrosis and eosinophilic airway inflammation, respectively. CONCLUSIONS: Overall, the results indicate that development of airway remodeling is regulated by the lung Th1/Th2 bias induced by GATA-3 and T-bet.

Nrf2-deficient mice are highly susceptible to cigarette smoke-induced emphysema.

Inflammation, protease/anti-protease imbalance and oxidative stress play important roles in the pathogenesis of emphysema. Nrf2 counteracts oxidative tissue damage and inflammation through transcriptional activation via the anti-oxidant responsive element (ARE). To clarify the protective role of Nrf2 in the development of emphysema, the susceptibility of Nrf2-knockout mice to cigarette smoke (CS)-induced emphysema was examined. In Nrf2-knockout mice, emphysema was first observed at 8 weeks and exacerbated by 16 weeks following CS-exposure, whereas no pathological abnormalities were observed in wild-type mice. Neutrophilic lung inflammation and permeability lung damage were significantly enhanced in Nrf2-knockout mice 8 weeks after CS-exposure. Importantly, neutrophil elastase activity in bronchoalveolar lavage fluids was markedly higher in Nrf2-knockout mice preceding the pronounced neutrophil accumulation. The expression of secretory leukoprotease inhibitor, a potent inhibitor of neutrophil elastase, was inducible in wild-type, but not in Nrf2-knockout mice. This protease/anti-protease imbalance, together with the lack of inducible expression of ARE-regulated anti-oxidant/anti-inflammatory genes, may explain the predisposition of Nrf2-knockout mice to neutrophilic inflammation. Indeed, specific activators of Nrf2 induced the expression of the SLPI gene in macrophages. These results indicate that Nrf2 protects against the development of emphysema by regulating not only the oxidant/anti-oxidant balance, but also inflammation and the protease/anti-protease balance.