Dupilumab Efficacy in Patients with Type 2 Asthma with and without Elevated Blood Neutrophils.

Introduction: Elevated neutrophil counts in blood, sputum, or lung have been associated with poor clinical outcomes and more severe disease in patients with type 2 asthma. In the phase 3 LIBERTY ASTHMA QUEST (NCT02414854), add-on dupilumab 200 and 300 mg every 2 weeks compared with matched placebo significantly reduced severe asthma exacerbations and improved forced expiratory volume in 1 s (FEV1) in patients with uncontrolled, moderate-to-severe asthma. This post hoc analysis explored the efficacy of dupilumab in patients with type 2 asthma enrolled in QUEST with or without elevated blood neutrophil counts. Methods: Annualized severe exacerbation rates during the 52-week treatment period and least-squares mean change from baseline in FEV1 over time were evaluated for patients with elevated type 2 biomarkers at baseline (blood eosinophils ≥ 150 cells/µL or fractional exhaled nitric oxide (FeNO) ≥ 20 ppb; and eosinophils ≥ 300 cells/µL or FeNO ≥ 50 ppb) and low (<4,000 cells/µL) or high (≥4,000 cells/µL) neutrophil counts. Results: Dupilumab significantly reduced annualized severe exacerbation rates compared with placebo during the 52-week treatment period in patients with elevated type 2 biomarkers, irrespective of baseline neutrophil count (P < 0.0001 for all comparisons). Significant improvements in FEV1 versus placebo were observed as early as Week 2 and over the 52-week treatment period, irrespective of baseline neutrophil count (P < 0.001 for all comparisons). Safety findings were similar across all subgroups, regardless of neutrophil counts at baseline. Conclusions: Dupilumab treatment significantly reduced annualized severe exacerbation rates and improved lung function in patients with uncontrolled, moderate-to-severe, type 2 asthma, irrespective of baseline blood neutrophil count. This trial is registered with NCT02414854.

Racial and Ethnic Minorities at the Highest Risk of Uncontrolled Moderate-to-Severe Asthma: A United States Electronic Health Record Analysis.

Purpose: The identification of risk factors associated with uncontrolled moderate-to-severe asthma is important to improve asthma outcomes. Aim of this study was to identify risk factors for uncontrolled asthma in United States cohort using electronic health record (EHR)-derived data. Patients and Methods: In this retrospective real-world study, de-identified data of adolescent and adult patients (≥12 years old) with moderate-to-severe asthma, based on asthma medications within 12 months prior to asthma-related visit (index date), were extracted from the Optum® Humedica EHR. The baseline period was 12 months prior to the index date. Uncontrolled asthma was defined as ≥2 outpatient oral corticosteroid bursts for asthma or ≥2 emergency department visits or ≥1 inpatient visit for asthma. A Cox proportional hazard model was applied. Results: There were 402,403 patients in the EHR between January 1, 2012, and December 31, 2018, who met the inclusion criteria and were analyzed. African American (AA) race (hazard ratio [HR]: 2.08), Medicaid insurance (HR: 1.71), Hispanic ethnicity (HR: 1.34), age of 12 to <18 years (HR 1.20), body mass index of ≥35 kg/m2 (HR: 1.20), and female sex (HR 1.19) were identified as risk factors associated with uncontrolled asthma (P < 0.001). Comorbidities characterized by type 2 inflammation, including a blood eosinophil count of ≥300 cells/µL (as compared with eosinophil <150 cells/µL; HR: 1.40, P < 0.001) and food allergy (HR: 1.31), were associated with a significantly higher risk of uncontrolled asthma; pneumonia was also a comorbidity associated with an increased risk (HR: 1.35) of uncontrolled asthma. Conversely, allergic rhinitis (HR: 0.84) was associated with a significantly lower risk of uncontrolled asthma. Conclusion: This large study demonstrates multiple risk factors for uncontrolled asthma. Of note, AA and Hispanic individuals with Medicaid insurance are at a significantly higher risk of uncontrolled asthma versus their White, non-Hispanic counterparts with commercial insurance.

Tezacaftor/ivacaftor in people with cystic fibrosis who stopped lumacaftor/ivacaftor due to respiratory adverse events.

BACKGROUND: Increased rates of respiratory adverse events have been observed in people ≥12 years of age with cystic fibrosis homozygous for the Phe508del-CFTR mutation treated with lumacaftor/ivacaftor, particularly in those with percent predicted forced expiratory volume in 1 s (ppFEV1) of <40%. We evaluated the safety, tolerability, and efficacy of tezacaftor/ivacaftor in people with cystic fibrosis homozygous for Phe508del-CFTR who discontinued lumacaftor/ivacaftor due to treatment-related respiratory signs or symptoms. METHODS: Participants ≥12 years of age with cystic fibrosis homozygous for Phe508del-CFTR with ppFEV1 of ≥25% and ≤90% were randomized 1:1 and treated with tezacaftor/ivacaftor or placebo for 56 days. RESULTS: Of 97 participants, 94 (96.9%) completed the study. The primary endpoint was incidence of predefined respiratory adverse events of special interest (chest discomfort, dyspnea, respiration abnormal, asthma, bronchial hyperreactivity, bronchospasm, and wheezing): tezacaftor/ivacaftor, 14.0%; placebo, 21.3%. The adverse events were mild or moderate in severity. None were serious or led to treatment interruption or discontinuation. Overall, the discontinuation rate was similar between groups. The mean (SD) ppFEV1 at baseline was 44.6% (16.1%) with tezacaftor/ivacaftor and 48.0% (18.1%) with placebo. The posterior mean difference in absolute change in ppFEV1 from baseline to the average value of days 28 and 56 was 2.7 percentage points with tezacaftor/ivacaftor vs placebo. CONCLUSIONS: Tezacaftor/ivacaftor was generally safe, well tolerated, and efficacious in people ≥12 years of age with cystic fibrosis homozygous for Phe508del-CFTR with ppFEV1 of ≥25% and ≤90% who previously discontinued lumacaftor/ivacaftor due to treatment-related respiratory signs or symptoms.

Clinical burden of asynchrony in patients with asthma when using metered-dose inhalers for control.

Background: Asynchrony, or lack of coordination between inhalation and actuation when using a pressurized metered-dose inhaler (MDI), could theoretically impact the delivery of inhaled medications and treatment efficacy. Objective: To assess the real-world association between asynchrony and clinical outcomes among patients with asthma who receive controller therapy delivered by MDIs. Methods: A cohort of patients was assembled via electronic health records. The patients were aged ≥12 years, with one or more documentations of an asthma diagnosis, no diagnosis of chronic obstructive pulmonary disease, and two or more prescriptions for an inhalation aerosol corticosteroid alone or with long-acting beta-2-agonist delivered via MDI. Their inhaler technique, demonstrated by using a placebo MDI, was evaluated at a clinic visit by study nurses who used a standardized 10-step checklist. Asynchrony was defined as any gap in timing between inhalation and actuation. Clinical outcomes were assessed via electronic health records during the 6 months before the clinic visit and were compared between patients with and patients without asynchrony by using multivariable regression analyses adjusted for age, gender, asthma severity proxy, and baseline comorbidities. Results: Of the total 254 eligible patients, mean age of 49.3 years, 90 males (35.4%), 32 (12.6%) had asynchrony. Patients with asynchrony had higher odds of an asthma exacerbation (adjusted odds ratio, 2.99; p = 0.009), and lower odds of risk domain asthma control (adjusted odds ratio, 0.41; p = 0.04) compared with patients without asynchrony. Conclusion: This study provided real-world evidence that asynchrony in MDI use among patients with asthma who were treated with controller MDIs was associated with clinical burden in terms of asthma exacerbations and control.

Comparing Ran-Out Status of Inhaled Short-Acting Beta-Agonists in Emergency Department Patients with Acute Asthma: 1996-1998 versus 2015-2017.

BACKGROUND: Medication nonadherence, including running out of inhaled asthma medications, is an important problem. OBJECTIVE: The objective of this study was to examine the changes in the proportion of adults with acute asthma who ran out of their short-acting beta-agonist (SABA) inhalers before presenting to the emergency department (ED) between 1996--1998 and 2015-2017. METHODS: We analyzed data from prospective multicenter observational cohort studies of ED adult patients (aged 18-54 years) with acute asthma. Within the same 3 EDs, we performed a structured interview during 2 time periods: 1996-1998 and 2015-2017. We fitted multivariable models to compare ran-out status between the 2 periods, adjusting for the baseline patient demographics, socioeconomic status, chronic asthma factors, and health care utilization factors. We further adjusted for the presence of a written action plan-an intervenable factor. RESULTS: The analytic cohort comprised 353 patients (150 from the 1996-1998 studies and 203 from the 2015-2017 study). Over the approximately 20-year period, the proportion of patients who ran out of SABA inhalers increased (18% in 1996-1998 vs 26% in 2015-2017). In the multivariable model, compared with patients in 1996-1998, those in 2015-2017 had a significantly higher risk of running out of their SABA inhalers (adjusted odds ratio [OR] 2.01; 95% confidence interval [CI] 1.06-3.81; P = .03). With further adjustment for the presence of a written action plan, this difference attenuated (adjusted OR 1.66; 95% CI 0.75-3.68; P = .21). CONCLUSIONS: Between 1996 and 2017, the proportion of ED patients with asthma who ran out of SABA inhalers significantly increased. The increase was explained, at least partially, by a lack of a written action plan.

Real-world health care utilization in asthma patients using albuterol sulfate inhalation aerosol (ProAir ® HFA) with and without integrated dose counters.

BACKGROUND: Accurate tracking of the administered dose of asthma rescue inhalers is critical for optimal disease management and is related to reductions in rates of unscheduled health care utilization in asthma patients. There are few published data on the real-world impact of rescue inhalers with integrated dose counters (IDCs) on health care resource utilization (HRU) for asthma patients. This study evaluates HRU among users of ProAir® hydrofluoroalkane (HFA) (albuterol sulfate inhalation aerosol), with IDC versus without IDC, in asthma patients. METHODS: This was a retrospective administrative claims study of asthma patients receiving a new prescription for albuterol inhalation aerosol without IDC during 2 years (January 2011-December 2012) or with IDC during the first full year after IDC implementation in the USA (July 2013-July 2014). Six months of continuous enrollment with medical and prescription drug benefits were required before and after the first prescription during the study period. Data on respiratory-related hospitalizations and emergency department (ED) visits were collected during the follow-up period. RESULTS: A total of 135,305 (32%) patients used albuterol inhalation aerosol with IDC, and 287,243 (68%) patients received albuterol inhalation aerosol without IDC. After adjusting for baseline confounding factors, the odds ratio (OR) for experiencing a respiratory-related hospitalization (OR=0.92; 95% confidence interval [CI] 0.88-0.96) or ED visit (OR=0.92; 95% CI 0.90-0.94) was significantly lower among patients using albuterol inhalation aerosol with IDC versus without IDC. CONCLUSION: In a real-world setting, asthma patients using ProAir HFA with IDC experienced significantly fewer hospitalizations and ED visits compared with patients using ProAir HFA without IDC. Dosage information provided by IDCs may allow providers to better understand patients' disease severity and aid in titrating controller medications and also decrease the likelihood that the canister will be empty when needed, thereby enhancing disease management and reducing HRU.

Historical cohort study examining comparative effectiveness of albuterol inhalers with and without integrated dose counter for patients with asthma or chronic obstructive pulmonary disease.

BACKGROUND: Using a metered-dose inhaler (MDI) beyond the labeled number of actuations may result in inadequate dosing of medication, which can lead to poor clinical outcomes. This study compared respiratory-related emergency department (ED) visit rates in patients with asthma, chronic obstructive pulmonary disease, or both when they used albuterol MDIs with versus without dose counters. METHODS: This retrospective study used US claims data to identify patients (ages 4-64 years) with asthma, chronic obstructive pulmonary disease, or both, using albuterol MDIs with or without an integrated dose counter. The study comprised a 1-year baseline period for patient characterization and confounder definition and a 1-year outcome period following the first albuterol prescription. The primary end point was the incidence rate of respiratory-related ED visits, compared using a reduced zero-inflated Poisson regression model. We also compared severe exacerbation rates and rescue medication use. RESULTS: A total of 93,980 patients were studied, including 67,251 (72%) in the dose counter cohort and 26,729 (28%) in the non-dose-counter cohort. The cohorts were broadly similar at baseline (55,069 [59%] female patients; median age, 37 years). The incidence rate of respiratory-related ED visits during the outcome year was 45% lower in the dose counter cohort than in the non-dose-counter cohort (adjusted rate ratio: 0.55; 95% confidence interval: 0.47-0.64). Exacerbation rates and short-acting ß-agonist use were similar between cohorts. CONCLUSION: These findings suggest that dose counter integration into albuterol MDIs is associated with decreased ED visit rates. The presence of integrated dose counters on rescue inhalers can help patients avoid using an empty or near-empty inhaler during exacerbations, thereby ensuring available medication for relief of their symptoms. Integrated dose counters on rescue MDIs could represent a simple and effective tool to improve clinical outcomes during exacerbations, with a potential for cost savings to health care systems.

The impact of expired and empty quick-relief asthma inhalers: The Asthma and Allergy Foundation of America's Asthma Inhaler Design Survey.

BACKGROUND: Despite the available treatments, asthma remains a serious illness, with a considerable socioeconomic burden associated with a high number of unscheduled visits to the emergency department (ED). Poor adherence and inadequate inhaler technique are contributing factors to poor asthma management and control. OBJECTIVE: The Asthma Inhaler Design Survey assessed the behaviors, attitudes, needs, and preferences of patients with asthma and their caregivers with regard to quick-relief inhaler usage and device design. METHODS: The Asthma and Allergy Foundation of America invited 19,157 adult patients and parents of children with asthma to take part in an online survey that focused on previous asthma diagnosis, symptom severity, and quick-relief and controller medication use. Opinions were also collected. RESULTS: Data from 590 respondents (366 adults; 224 children) were included in the final analysis. Relief inhalers were needed and found to be past the expiration date by 284 of 561 (50.6%) and relief inhalers were found to be empty by 270 of 560 (48.2%). Of the empty inhaler group, 28 of 270 (10.4%) had to visit the ED for treatment, 18 of 270 (6.7%) missed work or school for an unscheduled physician office visit, and 54 of 270 (20%) went without treatment. Although 78.5% indicated that they had at least two quick-relief inhalers nearby, these were not always easily accessible. Few respondents (194/578 [33.6%]) indicated that they and/or their child were very confident that they were using their inhaler properly, even though the majority had received some instruction. When asked what they would do to improve satisfaction with their quick-relief inhalers, 173 of 558 (31%) responded that they would add a dose counter. CONCLUSION: Unnecessary health care utilization and avoidable loss of time at work or school were associated with the lack of full availability of properly functioning quick-relief inhalers when needed. Adding a dose counter was the most frequently cited response for improving satisfaction with quick-relief inhalers. Confidence about proper inhaler use was low, despite previous instruction.

Fluticasone propionate/salmeterol 250/50 µg versus salmeterol 50 µg after chronic obstructive pulmonary disease exacerbation.

BACKGROUND: Inhaled long-acting beta2 agonists used alone and in combination with an inhaled corticosteroid reduce the risk of exacerbations in patients with stable COPD. However, the relative efficacy of these agents in preventing recurrent exacerbations in those recovering from an initial episode is not known. This study compared the rate of COPD exacerbations over the 26 weeks after an initial exacerbation in patients receiving the combination of fluticasone propionate and salmeterol (FP/SAL) or SAL alone. METHODS: Patients (n = 639) aged ≥40 years were randomized to either twice-daily inhaled FP/SAL 250/50 µg or SAL 50 µg. Primary, and secondary, endpoints were rates of recurrent severe, and moderate/severe, exacerbations of COPD. Lung function, health outcomes and levels of biomarkers of systemic inflammation were also assessed. RESULTS: There was no statistically significant treatment difference in rates of recurrent severe exacerbations (treatment ratio 0.92 [95% CI: 0.58, 1.45]) and moderate/severe exacerbations (0.82 [0.64, 1.06]) between FP/SAL and SAL in the intent-to-treat population. Pre-dose morning FEV1 change from baseline was greater (0.10 L [0.04, 0.16]) with FP/SAL than SAL. No treatment difference was seen for other endpoints including patient-reported health outcomes and biomarker levels for the full cohort. CONCLUSIONS: No significant treatment difference between FP/SAL and SAL was seen in COPD exacerbation recurrence for the complete cohort. Treatment benefit with FP/SAL over SAL (treatment ratio 0.68 [0.47, 0.97]) was seen in patients having FEV1 ≥ 30% and prior exposure to ICS. No unexpected safety issues were identified with either treatment. Patients with the most severe COPD may be more refractory to treatment. TRIAL REGISTRATION: ClinicalTrials.gov (identifier NCT01110200). This study was funded by GlaxoSmithKline (study number ADC113874).

Body mass index and response to asthma therapy: fluticasone propionate/salmeterol versus montelukast.

We studied the relationship between body mass index (BMI) on responses to asthma therapy using a retrospective analysis of four previously reported clinical trials. Fluticasone propionate (FP)/salmeterol via Diskus 100/50 microg twice daily and montelukast (MON) 10 mg daily were compared. BMI was classified as underweight (less than 20 kg/m(2)), normal (20-24.9 kg/m(2)), overweight (25-29.9 kg/m(2)), obese-1 (30-34.9 kg/m(2)), obese-2 (35-39.9 kg/m(2)), or obese-3 (at least 40 kg/m(2)). Outcomes assessed included forced expiratory volume in one second (FEV(1)), asthma symptom score, and albuterol use. FP/salmeterol produced greater improvements compared to MON in each of the asthma outcomes studied over the entire BMI range at the week-12 endpoint, with statistically significant differences noted among normal, overweight, obese-1, and obese-3 subjects. The within-treatment responses to FP/salmeterol across BMI ranges at the week-12 endpoint was statistically significantly greater in normal compared to obese-3 for FEV(1) and albuterol use, and in overweight compared to the obese-3 for each outcome studied. The within-treatment comparisons of MON across BMI ranges were significant for albuterol use in normal and underweight compared to obese-3 at the week-12 endpoint. Compared to subjects with normal BMI, the onset to peak FEV(1) may require longer treatment exposure in the very obese. Treatment responses to FP/salmeterol were consistently greater compared to MON and persisted at higher BMI.

Poly(ADP-ribose) polymerase-1 regulates vimentin expression in lung cancer cells.

Vimentin is one of the mammalian intermediate filament proteins. It is expressed in cells of mesenchymal origin and is characteristic of proliferating cells at the fetal stage. During malignancy, vimentin expression is activated in certain lung epithelial cells. Examination of a group of lung cancer cells showed a marked difference in their vimentin expression. The difference in vimentin expression among lung cancer cells is due to differential regulation at the transcriptional level. Analysis of the vimentin promoter revealed a 102-bp promoter sequence that is important for promoter activity in a lung cancer cell line in which vimentin is strongly expressed. This promoter region interacts with poly(ADP-ribose) polymerase-1 (PARP-1), which is also a transcription regulator. Exogenous expression of PARP-1 increased vimentin promoter activity. A shortened PARP-1 without the COOH-terminal catalytic domain showed the same promoter activation effect. Treatment of cells with H(2)O(2) reduced PARP-1 and vimentin expression at the protein level. H(2)O(2) also dose dependently suppressed vimentin promoter activity in cells overexpressing PARP-1. These results demonstrate that vimentin expression in lung cancer cells is regulated at the transcriptional level and that PARP-1 binds and activates the vimentin promoter independent of its catalytic domain and may play a role in H(2)O(2)-induced inhibition of vimentin expression.

Identification of a hydrogen peroxide-induced PP1-JNK1-Sp1 signaling pathway for gene regulation.

Oxidative stress often results in changes in gene expression through the regulation of transcription factors. In this study, we examine how Sp1 phosphorylation is regulated by H(2)O(2) in a human alveolar epithelial cell line (HAE). Treatment of HAE cells with H(2)O(2) increases phosphorylation of Sp1 and activates JNK. To establish a relationship between JNK and Sp1, we show that JNK activator anisomycin increases Sp1 phosphorylation, and JNK inhibitors as well as dominant-negative JNK1 attenuate H(2)O(2)-induced Sp1 phosphorylation. Additionally, JNK1 directly phosphorylates Sp1 in vitro, reducing Sp1 binding to DNA. These results demonstrate the role of JNK in H(2)O(2)-induced Sp1 phosphorylation. Because H(2)O(2) inhibits Ser/Thr protein phosphatase-1 (PP1), we examined the role of PP1 in the regulation of JNK. Similar to H(2)O(2), inhibition of PP1 induces phosphorylation of Sp1 and activation of JNK in HAE cells. Inhibition of JNK activity using either inhibitors or dominant-negative mutant JNK1 suppresses PP1 inhibition-induced Sp1 phosphorylation. Furthermore, PP1 directly inactivates JNK1 in vitro. These data suggest that 1) H(2)O(2) increases the phosphorylation level of Sp1, 2) Sp1 is a target of the JNK pathway, 3) PP1 regulates JNK activation, and 4) the "PP1-JNK" pathway plays a role in H(2)O(2)-induced Sp1 phosphorylation in lung epithelial cells.

Sp1: regulation of gene expression by phosphorylation.

As the prototype of a family of transcription factors, Sp1 has been extensively studied and widely reported for its role in gene regulation. The first evidence of Sp1 phosphorylation was reported more than a decade ago. Since then, an increasing number of Sp1 phosphorylation events have been characterized. Recent data demonstrate an important role for the phosphorylation state of Sp1 in the regulation of multiple genes. In this article, we review published literature in four specific areas relating to the phosphorylation of Sp1: (1) signal transduction pathways for Sp1 phosphorylation, (2) mechanisms of Sp1 dephosphorylation, (3) the functional implications of Sp1 phosphorylation, and (4) Sp1 phosphorylation in the lung.

Interferon-gamma regulates ClC-2 chloride channel in lung epithelial cells.

Epithelial Cl(-) channels mediate Cl(-) and fluid secretion in the lung. In cystic fibrosis, aberrant Cl(-) secretion is one of the major causes for lung fluid imbalance. Regulation of Cl(-) channels is therefore an important issue in the lung. IFN-gamma regulates Na(+) and Cl(-) channels and fluid transport in the lung, but the mechanisms involved in these regulations are not clear. In expression studies, we found that IFN-gamma increased ClC-2 transcripts in Calu-3 cells. Studies of the promoter identified a minimal promoter which interacts with transcription factors Sp1 and Sp3. However, reporter gene assays showed that IFN-gamma did not activate the promoter. Instead, IFN-gamma significantly increased ClC-2 transcript stability. Using Ussing chamber experiments, we demonstrate that IFN-gamma activates a pH-regulated and Cd(2+)-sensitive short circuit current, characteristic properties of the ClC-2 Cl(-) channel. These data suggest that IFN-gamma activates ClC-2 channel activity in lung epithelial cells via mRNA stabilization.

Overview of national treatment guidelines for common respiratory tract infections.

CAP, ABECB, and AOM are common community-acquired infections accounting for many office visits and many prescriptions for antibacterial agents. In addition, bacterial resistance to common antibacterial agents is on the rise and is related to antibacterial usage rates. Therefore, careful consideration is required before prescribing an antibacterial agent for a patient suspected of having one of these infections. Whenever possible, preventive strategies, including immunization, smoking cessation, and the correction of underlying anatomic defects, should be considered. Before prescribing an antibiotic, the provider should determine that the criteria for antibacterial usage are met in the patient. If an antibiotic must be used, then one should be selected that has a chance of curing the patient and preserving the sensitivity pattern of the community.

Improving adherence with antimicrobial therapy for respiratory tract infections: a discussion of directly observed therapy (DOT) and short-course therapies.

Although some of the variables associated with adherence (eg, patient age, place of residence) cannot be influenced, others are very amenable to modifications. Levels of adherence correlate with the convenience of dosage regimens, as shown in a number of clinical trials. Therefore, antimicrobial agents that are well accepted by patients should be considered whenever feasible. Such agents include those that enable shortterm therapy with the fewest daily doses and shortest effective treatment regimens. DOT, a cost-effective and clinically effective approach for certain chronic conditions, may also have practical implications for the treatment of acute infectious diseases, such as CAP, AECB, and otitis media. Although there are a number of challenges to the implementation of DOT for these conditions, such an approach may be beneficial, particularly when short-course antibiotic therapy is indicated and appropriate candidates are identified for treatment.

Expression of alpha-ENaC2 is dependent on an upstream Sp1 binding motif and is modulated by protein phosphatase 1 in lung epithelial cells.

The amiloride-sensitive Na(+) channel ENaC is expressed in lung epithelium and plays a pivotal role in lung fluid clearance in the newborn. Multiple splice variants of the ENaC alpha-subunit have been reported. Among them, alpha-ENaC2 accounts for a considerable portion of alpha-ENaC transcripts in human lung and kidney, possesses channel functions similar to alpha-ENaC1, and is driven by a downstream promoter. In the current study, we examine the regulation of alpha-ENaC2 transcription in lung epithelial cells. We found that transcription factors Sp1 and Sp3 activate alpha-ENaC2 transcription through a GC-rich element (Sp1-binding site) in the promoter. Because alpha-ENaC expression and Sp1 phosphorylation are both significantly up-regulated in the perinatal lung, we then examined the possible connection between Sp1/Sp3 phosphorylation and alpha-ENaC2 expression. We found that protein phosphatase 1 (PP1) dephosphorylates Sp1 and Sp3 in lung epithelial cells, reduces their binding to the alpha-ENaC2 promoter, and decreases Sp1/Sp3-mediated promoter activity. Our results suggest that Sp1 and Sp3 are essential for alpha-ENaC2 transcription in lung epithelial cells and that dephosphorylation of the Sp transcription factors by PP1 suppresses alpha-ENaC2 expression. The significance of these findings in the regulation of gene expression in perinatal lung is discussed.

Enfermedad pulmonar obstructiva crónica: nuevos enfoques

Uno de los más graves y costosos problemas de salud es, sin duda, la enfermedad pulmonar obstructiva crónica, bien conocida en el ambiente médico por su sigla EPOC. El principal factor en su actual desmesurado desarrollo es, sin duda, el hábito de fumar. Frente a esta situación, son indispensables las medidad preventivas que ayudan tambíen a mejorar la situación de quienes ya están afectados y han aparecido medicamentos que permiten mejorar la función pulmonar, lo cual lleva a nuevos enfoques que parecen abrir esperanzas par el futuro inmediato en este campo