Acute effect of oxygen therapy on exercise tolerance and dyspnea perception in ILD patients.

Ambulatory oxygen therapy (AOT) is commonly prescribed in interstitial lung disease (ILD) patients, with the aim of reducing dyspnea and increasing exercise tolerance. Despite its frequent use and a reasonable physiological rationale, there is a lack of evidence supporting the effect of AOT on improving dyspnea during exercise. Moreover, dyspnea encompasses distinct sensory (intensity, quality) and affective (anxiety, fear) components with different underlying neurophysiological mechanisms. The aim of this study was to evaluate the effect of oxygen supplementation on exercise tolerance and dyspnea in ILD patients with exercise induced hypoxia (EIH). Forty-seven ILD patients performed a six-minute walk test (6MWT) on room air (RA) and with oxygen supplementation (Ox). The 6MWT distance (6MWD) was significantly greater with oxygen supplementation (RA: 242±143 m vs Ox: 345±106 m p<0,01). With oxygen supplementation, the overall dyspnea and anxiety significantly decreased both at rest [1.1±1.4 Borg Unit (BU)] vs 0.4±0.9BU, p.<0.01, and 1.1±1.6BU vs 0.5±1.3 BU, p.<0.05, respectively) and at the end of exercise (5.1±2.6 BU vs 3.7±2.5 BU, p<0.001 and 3.4 ±2.9 vs 2.5±2.8, p.<0.01, respectively) despite a greater walked distance. In ILD patients with EIH, oxygen supplementation increases the exercise tolerance and reduces overall dyspnea perception and the anxiety component of breathlessness.

Are there pulmonary sequelae in patients recovering from COVID-19?

It has been recently hypothesized that infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may lead to fibrotic sequelae in patients recovering from coronavirus disease 2019 (COVID-19). In this observational study, hospitalized patients with COVID-19 had a HRCT of the chest performed to detect the extension of fibrotic abnormalities via Hounsfield Units (HU). At follow-up, the lung density significantly improved in both lungs and in each lobe of all patients, being in the normal range (- 950 to - 700 HU). This study provides preliminary evidence that hospitalized patients with mild-to-moderate forms of COVID-19 are not at risk of developing pulmonary fibrosis.

Subjective neurological symptoms frequently occur in patients with SARS-CoV2 infection.

OBJECTIVE: Coronavirus disease 2019 (COVID-19) represents a novel pneumonia leading to severe acute respiratory syndrome (SARS). Recent studies documented that SARS-Coronavirus2 (SARS-CoV2), responsible for COVID-19, can affect the nervous system. The aim of the present observational study was to prospectively assess subjective neurological symptoms (sNS) in patients with SARS-CoV2 infection. METHODS: We included patients hospitalized at the University Hospital of Rome "Tor Vergata", medical center dedicated to the treatment of patients with COVID-19 diagnosis, who underwent an anamnestic interview about sNS consisting of 13 items, each related to a specific symptom, requiring a dichotomized answer. RESULTS: We included 103 patients with SARS-CoV2 infection. Ninety-four patients (91.3%) reported at least one sNS. Sleep impairment was the most frequent symptom, followed by dysgeusia, headache, hyposmia, and depression. Women more frequently complained hyposmia, dysgeusia, dizziness, numbeness/paresthesias, daytime sleepiness, and muscle ache. Moreover, muscle ache and daytime sleepiness were more frequent in the first 2 days after admission. Conversely, sleep impairment was more frequent in patients with more than 7 days of hospitalization. In these patients we also documented higher white blood cells and lower C-reactive protein levels. These laboratory findings correlated with the occurrence of hyposmia, dysgeusia, headache, daytime sleepiness, and depression. CONCLUSIONS: Patients with SARS-CoV2 infection frequently present with sNS. These symptoms are present from the early phases of the disease. The possibly intrinsic neurotropic properties of SARS-CoV2 may justify the very high frequency of sNS. Further studies targeted at investigating the consequences of SARS-CoV2 infection on the CNS should be planned.

Dyspnea perception and neurological symptoms in non-severe COVID-19 patients.

INTRODUCTION: The relationship between dyspnea and COVID-19 is unknown. In COVID-19 patients, the higher prevalence of neurological symptoms and the lack of dyspnea may suggest common underlying pathogenetic mechanisms. The aim of this preliminary study is to address whether there is a lack of dyspnea in COVID-19 patients and if there is a relationship between neurological symptoms and the perception of dyspnea. METHODS: A structured interview regarding the occurrence of subjective neurological symptoms was performed and coupled with a questionnaire about the intensity and qualities of dyspnea. Respiratory rate (RR) and an arterial blood gas on room air were concurrently evaluated. RESULTS: Twenty-two patients (age 68.4 ± 13.9 years, 13 males and 9 females) were included and divided into two groups according to the Borg dyspnea scale: dyspneic patients BU ≥ 1(DYSP) and non-dyspneic patients BU < 1 (NDYSP). The prevalence of dyspnea overall was 31.8%. The prevalence of neurological symptoms, dyspnea descriptors, RR, pH, PaCO2, PaO2, or lactate was similar between groups. CONCLUSION: This study confirms that the prevalence of dyspnea is low in non-severe COVID-19 patients, but contrary to our hypothesis of a relationship between shortness of breath and neurological symptoms, we have not been able to find any evidence of an impairment in dyspnea perception, either in the DYSP or NDYSP group.

Efficacy and safety profile of mucolytic/antioxidant agents in chronic obstructive pulmonary disease: a comparative analysis across erdosteine, carbocysteine, and N-acetylcysteine.

BACKGROUND: To date there are no head-to-head studies comparing different mucolytic/antioxidant agents. Considering the inconsistent evidence resulting from the pivotal studies on mucolytic/antioxidant agents tested in chronic obstructive pulmonary disease (COPD), and the recent publication of Reducing Exacerbations and Symptoms by Treatment with ORal Erdosteine in COPD (RESTORE) study, we have performed a meta-analysis to compare the efficacy and safety of erdosteine 600 mg/day, carbocysteine 1500 mg/day, and N-acetylcysteine (NAC) 1200 mg/day in COPD. METHODS: A pairwise and network meta-analyses were performed to assess the efficacy of erdosteine, carbocysteine, and NAC on acute exacerbation of COPD (AECOPD), duration of AECOPD, and hospitalization. The frequency of adverse events (AEs) was also investigated. RESULTS: Data obtained from 2753 COPD patients were extracted from 7 RCTs published between 2004 and 2017. In the pairwise meta-analysis mucolytic/antioxidant agents significantly reduced the risk of AECOPD (RR 0.74 95%CI 0.68-0.80). The network meta-analysis provided the following rank of effectiveness: erdosteine>carbocysteine>NAC. Only erdosteine reduced the risk of experiencing at least one AECOPD (P < 0.01) and the risk of hospitalization due to AECOPD (P < 0.05). Erdosteine and NAC both significantly reduced the duration of AECOPD (P < 0.01). The AEs induced by erdosteine, carbocysteine, and NAC were mild in severity and generally well tolerated. The quality of evidence of this quantitative synthesis is moderate. CONCLUSIONS: The overall efficacy/safety profile of erdosteine is superior to that of both carbocysteine and NAC. Future head-to-head studies performed on the same COPD populations are needed to definitely confirm the results of this meta-analysis. TRIAL REGISTRATION: CRD42016053762 .

Efficacy and cardiovascular safety profile of dual bronchodilation therapy in chronic obstructive pulmonary disease: A bidimensional comparative analysis across fixed-dose combinations.

Despite several long-acting ß2-adrenoceptor agonist (LABA)/long-acting muscarinic antagonist (LAMA) fixed-dose combinations (FDCs) are currently approved for the treatment of chronic obstructive pulmonary disease (COPD), there are limited findings concerning the direct comparison across the different LABA/LAMA FDCs. The aim of this study was to compare the efficacy/safety profile of approved LABA/LAMA FDCs in COPD. A network meta-analysis was performed by linking the efficacy (forced expiratory volume in 1 s, St' George Respiratory Questionnaire, transitional dyspnea index) and safety (cardiovascular serious adverse events) outcomes resulting from randomized controlled trials that directly compared LABA/LAMA FDCs with placebo and/or each other. The Surface Under the Cumulative Ranking Curve Analysis (SUCRA) was performed for each single outcome (SUCRA: 1 = best, 0 = worst). The combined efficacy/safety profile was reported via the novel Improved Bidimensional SUCRA score (IBiS: the higher the value the better the treatment). Data obtained from 12,136 COPD patients (79.50% LABA/LAMA FDCs vs. placebo; 20.50% direct comparison between different LABA/LAMA FDCs) were extracted from 22 studies published between 2013 and 2019. The IBiS score showed the following rank of efficacy/safety profile: tiotropium/olodaterol 5/5 µg (area 66.83%) ¼ glycopyrronium/indacaterol 15.6/27.5 µg (area 40.43%)  >  umeclidinium/vilanterol 62.5/25 µg (area 30.48%)  ≈  aclidinium/formoterol 400/12 µg (area 28.44%)  >  glycopyrronium/indacaterol 50/110 µg (area 19.95%)  >  glycopyrronium/formoterol 14.4/9.6 µg (area 11.50%). Each available LABA/LAMA FDC has a specific efficacy/safety profile that needs to be considered for personalized therapy in COPD. Head-to-head studies aimed to assess the impact of different LABA/LAMA FDCs on the risk of COPD exacerbation are needed to further improve the information provided by this quantitative synthesis.

Emerging biological therapies for treating chronic obstructive pulmonary disease: A pairwise and network meta-analysis.

Inflammation in chronic obstructive pulmonary disease (COPD) is often corticosteroid resistant and, thus, alternative anti-inflammatory approaches are needed. Since it is still not clear whether blocking specific pro-inflammatory factors may provide clinical benefit in COPD, we have performed a meta-analysis to quantify the impact of monoclonal antibodies (mABs) targeting the cytokine/chemokine-mediated inflammation in COPD. A pairwise and network meta-analyses were performed by extracting data from randomized clicnial trials on COPD concerning the impact of mABs vs. placebo on the risk of exacerbation, forced expiratory volume in 1 s (FEV1), and St. George's Respiratory Questionnaire (SGRQ). Data on the interleukin (IL)-1ß antagonist canakinumab, IL-1R1 antagonist MEDI8986, IL-5 antagonist mepolizumab, IL-5R antagonist benralizumab, IL-8 antagonist ABX-IL8, and TNF-α antagonist infliximab were found. Overall, mAB therapy had a moderate impact on the risk exacerbation, but not on FEV1 and SGRQ. The pairwise meta-analysis performed in eosinophilic patients, and the network approach, indicated that mepolizumab elicited a beneficial effect against the risk of exacerbation, whereas benralizumab was more effective in improving both FEV1 and SGRQ. This study demonstrates that targeting the pathway activated by IL-5 may have a beneficial impact in eosinophilic COPD patients.

Effect of adding roflumilast or ciclesonide to glycopyrronium on lung volumes and exercise tolerance in patients with severe COPD: A pilot study.

COPD is a chronic inflammatory disease characterized by partially reversible airflow limitation. Currently, phosphodiesterase4 inhibitors and inhaled corticosteroids are anti-inflammatory agents that can be used in patients with severe COPD, always added to at least one bronchodilator. In this prospective interventional pilot study, we investigated the effect of adding oral roflumilast 500 µg once-daily or inhaled ciclesonide 160 µg once-daily to glycopyrronium 44 µg once-daily on lung volumes and exercise tolerance in 16 patients with severe COPD, of which 8 received roflumilast and 8 ciclesonide for 8 weeks. Detailed pulmonary function and endurance shuttle tests were performed at time 0, after 2 weeks of glycopyrronium and after 8 weeks of add-on of either roflumilast or ciclesonide. Glycopyrronium increased significantly (p < .05) FEV1, and IC at rest and at the peak of exercise and improved the walking distance. In particular, it induced a bronchodilation similar to that elicited by salbutamol 800 µg. After 8 weeks of combination therapy, both the trough and the post bronchodilator FEV1 further improved but the increase was very small and not significant. Furthermore, adding either roflumilast or ciclesonide did not provide a further improvement in IC and walking distance. This study provides further evidence of the efficacy of glycopyrronium 44 µg once daily, confirming that improvements in airflow are associated with increases in IC and improvements in exercise tolerance. The addition of anti-inflammatory drugs, regardless of class used, does not seem to add benefits on lung function and exercise tolerance, likely because of the large effect induced by glycopyrronium.

Pharmacological characterisation of the interaction between glycopyrronium bromide and indacaterol fumarate in human isolated bronchi, small airways and bronchial epithelial cells.

BACKGROUND: Nowadays, there is a considerable gap in knowledge concerning the mechanism(s) by which long-acting ß2-agonists (LABAs) and long-acting muscarinic antagonists (LAMAs) interact to induce bronchodilation. This study aimed to characterise the pharmacological interaction between glycopyrronium bromide and indacaterol fumarate and to identify the mechanism(s) leading to the bronchorelaxant effect of this interaction. METHODS: The effects of glycopyrronium plus indacaterol on the contractile tone of medium and small human isolated bronchi were evaluated, and acetylcholine and cAMP concentrations were quantified. The interaction was assessed by Bliss Independence approach. RESULTS: Glycopyrronium plus indacaterol synergistically inhibited the bronchial tone (medium bronchi, +32.51 % ± 7.86 %; small bronchi, +28.46 % ± 5.35 %; P < 0.05 vs. additive effect). The maximal effect was reached 140 min post-administration. A significant (P < 0.05) synergistic effect was observed during 9 h post-administration on the cholinergic tone, but not on the histaminergic contractility. Co-administration of glycopyrronium and indacaterol reduced the release of acetylcholine from the epithelium but not from bronchi, and enhanced cAMP levels in bronchi and epithelial cells (P < 0.05 vs. control), an effect that was inhibited by the selective KCa(++) channel blocker iberiotoxin. The role of cAMP-dependent pathway was confirmed by the synergistic effect elicited by the adenylate cyclase activator forskolin on glycopyrronium (P < 0.05 vs. additive effect), but not on indacaterol (P > 0.05 vs. additive effect), with regard of the bronchial relaxant response and cAMP increase. CONCLUSIONS: Glycopyrronium/indacaterol co-administration leads to a synergistic improvement of bronchodilation by increasing cAMP concentrations in both airway smooth muscle and bronchial epithelium, and by decreasing acetylcholine release from the epithelium.

Interaction between corticosteroids and muscarinic antagonists in human airways.

BACKGROUND: To date there is emerging clinical evidence to add long-acting anti-muscarinic agents (LAMAs) with inhaled corticosteroid (ICSs) in asthma, but the pharmacological rationale that supports the use of such a combination has not yet been explained. The aim of this study was to pharmacologically investigate the interaction between the ICS beclomethasone and the LAMA glycopyrronium on the human airway smooth muscle (ASM) tone. METHODS: We investigated the rapid non-genomic bronchorelaxant effect of beclomethasone and glycopyrronium, administered alone and in combination, in human isolated bronchi and bronchioles. Experiments were carried out also in passively sensitized airways and the pharmacological analysis of drug interaction was performed by Bliss Independence method. RESULTS: The acute administration of beclomethasone and glycopyrronium induced a significant relaxation of passively sensitized ASM pre-contracted with histamine, by causing submaximal/maximal inhibition of the contractile tone in both medium bronchi and bronchioles. Beclomethasone was characterized by a rapid non-genomic and epithelium independent bronchorelaxant effect. In passively sensitized airways, this effect seemed to be dependent by the activation of a Gsα--cyclic adenosine monophosphate (cAMP)--protein kinase A cascade. While no synergistic interaction was detected in non-sensitized bronchi, the beclomethasone/glycopyrronium combination synergistically enhanced the relaxation of passively sensitized medium and small bronchi. The synergistic interaction between beclomethasone and glycopyrronium was associated with an increase of cAMP concentrations. CONCLUSIONS: Our study provides for the first time the pharmacological rationale for combining low doses of an ICS plus a LAMA.

Onset of action of budesonide/formoterol Spiromax(®) compared with budesonide/formoterol Turbuhaler(®) in patients with COPD.

Budesonide/formoterol (BF) is available in two delivery systems, the dry powder inhaler (DPI) Turbuhaler and a pressurized metered dose inhaler (pMDI) for use in patients with asthma or chronic obstructive pulmonary disease (COPD). Spiromax DPI was recently developed as an alternative to Turbuhaler DPI. In the present study, we examined whether there is a difference in the onset of bronchodilatation between BF 320/9 µg delivered by Spiromax and BF 320/9 µg delivered by Turbuhaler in 16 outpatients with stable moderate-to-severe COPD. Our results confirm the rapid onset of action of formoterol when combined with budesonide in patients with COPD and indicate that the onset of bronchodilation induced by BF Spiromax is faster than that elicited by BF Turbuhaler. Furthermore, they show that BF fixed-dose combination does not induce a decrease in SpO2 or an increase in heart rate in patients with COPD, irrespective of the DPI used to deliver this combination. Given the evidence that both inhalers have an equal safety profile, BF Spiromax offers to prescribers and COPD patients an effective alternative to BF Turbuhaler depending also on their preference, availability and cost.

HFE gene variants and iron-induced oxygen radical generation in idiopathic pulmonary fibrosis.

In idiopathic pulmonary fibrosis (IPF), lung accumulation of excessive extracellular iron and macrophage haemosiderin may suggest disordered iron homeostasis leading to recurring microscopic injury and fibrosing damage. The current study population comprised 89 consistent IPF patients and 107 controls. 54 patients and 11 controls underwent bronchoalveolar lavage (BAL). Haemosiderin was assessed by Perls' stain, BAL fluid malondialdehyde (MDA) by high-performance liquid chromatography, BAL cell iron-dependent oxygen radical generation by fluorimetry and the frequency of hereditary haemochromatosis HFE gene variants by reverse dot blot hybridisation. Macrophage haemosiderin, BAL fluid MDA and BAL cell unstimulated iron-dependent oxygen radical generation were all significantly increased above controls (p<0.05). The frequency of C282Y, S65C and H63D HFE allelic variants was markedly higher in IPF compared with controls (40.4% versus 22.4%, OR 2.35, p=0.008) and was associated with higher iron-dependent oxygen radical generation (HFE variant 107.4±56.0, HFE wild type (wt) 59.4±36.4 and controls 16.7±11.8 fluorescence units per 10(5) BAL cells; p=0.028 HFE variant versus HFE wt, p=0.006 HFE wt versus controls). The data suggest iron dysregulation associated with HFE allelic variants may play an important role in increasing susceptibility to environmental exposures, leading to recurring injury and fibrosis in IPF.

Iron laden macrophages in idiopathic pulmonary fibrosis: the telltale of occult alveolar hemorrhage?

RATIONALE: A number of observations suggest that iron accumulates in the lungs of patients with idiopathic pulmonary fibrosis (IPF) with vascular abnormalities, including pulmonary hypertension. OBJECTIVES: The aim of this study was to determine the prevalence and intensity of accumulation of alveolar epithelial lining fluid (ELF) iron and of alveolar macrophage hemosiderin in IPF and its relationship with disease severity. METHODS: Forty seven IPF patients and 14 healthy controls were retrospectively evaluated for iron accumulation in the lower respiratory tract using total iron spectrophotometric measures and for hemosiderin accumulation using the Perls' stain with the Golde score. MEASUREMENTS AND MAIN RESULTS: Total iron levels in ELF were significantly increased in IPF patients compared to non-smoking controls (p < 0.05); there were no differences with healthy smokers (p = 0.2). Hemosiderin accumulation in alveolar macrophages was similar in never smoking and ever smoking IPF patients (p = 0.5), was significantly higher in IPF patients than in both smoking and non-smoking healthy controls (p < 0.05, all comparisons) and was positively correlated with echocardiographic estimates of pulmonary artery systolic pressure (p < 0.05) and with increasing disease severity scores (p < 0.05). CONCLUSIONS: The data show exaggerated accumulation of iron in IPF broncho-alveolar ELF and alveolar cells with no association with tobacco smoke, thus suggesting, occult pulmonary hemorrhage as a likely cause.

Role of exosomes in exacerbations of asthma and COPD: a systematic review.

Asthma and chronic obstructive pulmonary disease are chronic respiratory disorders characterized by airways obstruction and chronic inflammation. Exacerbations lead to worsening of symptoms and increased airflow obstruction in both airways diseases, and they are associated with increase in local and systemic inflammation. Exosomes are cell-derived membrane vesicles containing proteins, lipids, and nucleic acids that reflect their cellular origin. Through the transfer of these molecules, exosomes act as mediators of intercellular communication. Via selective delivery of their contents to target cells, exosomes have been proved to be involved in regulation of immunity and inflammation. Although, exosomes have been extensively investigated in different diseases, little is currently known about their role in asthma and COPD pathogenesis, and particularly in exacerbations. This review aims to systemically assess the potential role of exosomes in asthma and COPD exacerbations.

Spontaneous Ventilation Thoracoscopic Lung Biopsy in Undetermined Interstitial Lung Disease: Systematic Review and Meta-Analysis.

Thoracoscopic surgical biopsy has shown excellent histological characterization of undetermined interstitial lung diseases, although the morbidity rates reported are not negligible. In delicate patients, interstitial lung disease and restrictive ventilatory impairment morbidity are thought to be due at least in part to tracheal intubation with single-lung mechanical ventilation; therefore, spontaneous ventilation thoracoscopic lung biopsy (SVTLB) has been proposed as a potentially less invasive surgical option. This systematic review summarizes the results of SVTLB, focusing on diagnostic yield and operative morbidity. A systematic search for original studies regarding SVTLB published between 2010 to 2023 was performed. In addition, articles comparing SVTLB to mechanical ventilation thoracoscopic lung biopsy (MVTLB) were selected for a meta-analysis. Overall, 13 studies (two before 2017 and eleven between 2018 and 2023) entailing 675 patients were included. Diagnostic yield ranged from 84.6% to 100%. There were 64 (9.5%) complications, most of which were minor. There was no 30-day operative mortality. When comparing SVTLB to MVTLB, the former group showed a significantly lower risk of complications (p < 0.001), whereas no differences were found in diagnostic accuracy. The results of this review suggest that SVTLB is being increasingly adopted worldwide and has proven to be a safe procedure with excellent diagnostic accuracy.

Expert guidance on the management and challenges of long-COVID syndrome: a systematic review.

INTRODUCTION: Long-COVID is a condition characterized by the permanence of symptoms beyond 4 weeks after an initial infection. It affects 1 out of 5 people and is loosely related to the severity of acute infection and pathological mechanisms, which are yet to be understood. AREAS COVERED: This article looks at currently available and under-studied therapies for long-COVID syndrome. It particularly gives focus to ongoing trials and reviews the underlying mechanisms. A comprehensive literature search was performed on PubMed and clincaltrial.gov of clinical trials concerning the management of long-COVID syndrome. EXPERT OPINION: 'Long-COVID' syndrome is a new emergency characterized by several symptoms such as fatigue, dyspnea, cognitive and attention disorders, sleep disorders, post-traumatic stress disorder, muscle pain, and concentration problems. Despite the many guidelines available to date, there are no established treatments of long-COVID. Pharmacological research is studying known drugs that act on the reduction or modulation of systemic inflammation, or innovative drugs used in similar pathologies. Rehabilitation now seems to be the safest treatment to offer, whereas we will have to wait for the pharmacological research trials in progress as well as plan new trials based on a better understanding of the pathogenic mechanisms.

Interaction of phosphodiesterase 3A with brefeldin A-inhibited guanine nucleotide-exchange proteins BIG1 and BIG2 and effect on ARF1 activity.

ADP-ribosylation factors (ARFs) have crucial roles in vesicular trafficking. Brefeldin A-inhibited guanine nucleotide-exchange proteins (BIG)1 and BIG2 catalyze the activation of class I ARFs by accelerating replacement of bound GDP with GTP. Several additional and differing actions of BIG1 and BIG2 have been described. These include the presence in BIG2 of 3 A kinase-anchoring protein (AKAP) domains, one of which is identical in BIG1. Proteins that contain AKAP sequences act as scaffolds for the assembly of PKA with other enzymes, substrates, and regulators in complexes that constitute molecular machines for the reception, transduction, and integration of signals from cAMP or other sources, which are initiated, propagated, and transmitted by chemical, electrical, or mechanical means. Specific depletion of HeLa cell PDE3A with small interfering RNA significantly decreased membrane-associated BIG1 and BIG2, which by confocal immunofluorescence microscopy were widely dispersed from an initial perinuclear Golgi concentration. Concurrently, activated ARF1-GTP was significantly decreased. Selective inhibition of PDE3A by 1-h incubation of cells with cilostamide similarly decreased membrane-associated BIG1. We suggest that decreasing PDE3A allowed cAMP to accumulate in microdomains where its enzymatic activity limited cAMP concentration. There, cAMP-activated PKA phosphorylated BIG1 and BIG2 (AKAPs for assembly of PKA, PDE3A, and other molecules), which decreased their GEP activity and thereby amounts of activated ARF1-GTP. Thus, PDE3A in these BIG1 and BIG2 AKAP complexes may contribute to the regulation of ARF function via limitation of cAMP effects with spatial and temporal specificity.