Search Results (83)

Cystic fibrosis (CF), the most common hereditary lung disease in Caucasians, is caused by dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR). We evaluated CFTR function using a newly developed Ussing chamber system, the Multi Trans Epithelial Current Clamp (MTECC), in an in vitro model of human airway epithelia. Air–liquid interface (ALI) cultures were established from nasal brushings of healthy controls (HC) and CF patients with biallelic CFTR variants. ALI layer thickness was similar between groups (HC: 62 ± 13 µm; CF: 55 ± 9 µm). Immunofluorescence showed apical CFTR expression in HC, but reduced or absent signal in CF cultures. MTECC enabled continuous measurement of transepithelial resistance (Rt), potential difference (PD), and conductance (G_t). G_t was significantly reduced in CF cultures compared to HC (0.825 ± 0.024 vs. −0.054 ± 0.016 mS/cm²), indicating impaired cAMP-inducible ion transport by CFTR. Treatment of CF cultures with elexacaftor, tezacaftor, and ivacaftor (Trikafta^®) increased G_t, reflecting partial restoration of CFTR function. These findings demonstrate the utility of MTECC in detecting functional differences in CFTR activity and support its use as a platform for evaluating CFTR-modulating therapies. Our model may contribute to the development of personalized treatment strategies for CF patients. Full article

There is a well-established association between cystic fibrosis (CF) and malnutrition. Several comorbid conditions have also been associated with undernutrition in people with cystic fibrosis (PwCF). Highly effective modulator therapy has allowed for a paradigm shift altering disease progression and management. Modulator use has even been associated with acceleration of weight trajectory causing overnutrition, which can lead to cardiovascular and metabolic comorbid conditions. This review explores how nutritional status is evolving in the era of cystic fibrosis transmembrane conductance regulator (CFTR) modulators in people with CF, specifically in children. By synthesizing current research, we aim to support pediatric healthcare providers and nutritionists in delivering tailored, proactive nutritional care in this new therapeutic landscape. Full article

Cystic fibrosis (CF) is the most common severe autosomal recessive disease among Caucasians. Modulators of cystic fibrosis transmembrane conductance regulator (CFTR) mutated protein significantly improved the outcome of subjects with CF. In the present study, we studied epigenetic age, applying the Horvath clock model, in 52 adult subjects with CF, all treated with elexacaftor/tezacaftor/ivacaftor (ETI). At baseline (T0), we found that half of the subjects have a significantly accelerated epigenetic age and a worse lung function, evaluated by forced expiratory volume in one second (FEV1). One year of ETI therapy (T1) impacted both the parameters, indicating that therapy with modulators must be started early, particularly in CF subjects with impaired lung function. The second group of CF subjects had an epigenetic age lower than the chronological one at T0 and lung function was better maintained. In these subjects, ETI therapy further improved lung function and tended to increase the epigenetic age, possibly improving metabolic functions and the general state of well-being. This also translates into an increase in the physical activities of a group of subjects who, before the therapy, had grown up under a glass bell. The analysis of epigenetic age may represent a potential biomarker to assess the individual outcome of the therapy in subjects with CF, although long-term studies need to evaluate it. Full article

Background: Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Modulator therapies have the ability to improve CFTR function in CF patients, but despite the clear evidence of benefits regarding CFTR modulator therapy, including improved lung function, the reduced rate of exacerbations, and an overall improved quality of life, studies focusing on the reduction rates of P. aeruginosa infections during modulator therapy expressed the need for future research on this topic. Objective: This study aimed to evaluate the impact of CFTR modulator therapies on the prevalence, density, and persistence of P. aeruginosa infection in CF patients and to explore the mechanisms involved. Methods: A systematic literature review was performed by searching five major databases (PubMed, Cochrane Library, Scopus, Google Scholar, and Web of Science), and 21 relevant articles investigating the link between CFTR therapy and P. aeruginosa infections were selected following the PRISMA guidelines. Results: The data indicated that Ivacaftor and the combination Elexacaftor/Tezacaftor/Ivacaftor (ETI) can reduce total bacterial load and markers of systemic inflammation. However, clonal lines of P. aeruginosa persist in most cases, and complete eradication is rare, mainly due to biofilm formation and antimicrobial resistance. Conclusions: Although CFTR-modulating therapies help to improve clinical condition and reduce inflammation, they do not consistently lead to the elimination of P. aeruginosa. Full article

Cystic fibrosis (CF) is a life-limiting autosomal recessive disorder affecting a large number of individuals in Europe. The disease arises from mutations in the CFTR gene encoding the cystic fibrosis transmembrane conductance regulator, a chloride ion channel crucial for maintaining epithelial ion and fluid homeostasis. Dysfunctional CFTR disrupts mucociliary clearance, particularly in the respiratory tract, resulting in persistent bacterial colonization, chronic inflammation, and progressive pulmonary damage—ultimately leading to respiratory failure, the principal cause of mortality in CF patients. Early diagnosis and advances in therapy have substantially improved both survival and quality of life. A hallmark of CF pathology is the establishment of polymicrobial infections within the thickened airway mucus. Pseudomonas aeruginosa is the dominant pathogen in chronic CF lung infections and demonstrates a remarkable capacity for adaptation via biofilm formation, metabolic reprogramming, and immune evasion. Biofilms confer increased tolerance to antimicrobial agents and facilitate long-term persistence in hypoxic, nutrient-limited microenvironments. P. aeruginosa exhibits a wide range of virulence factors, including exotoxins (e.g., ExoU, ExoS), pigments (pyoverdine, pyochelin), and motility structures (flagella and pili), which contribute to tissue invasion, immune modulation, and host damage. During chronic colonization, P. aeruginosa undergoes significant genotypic and phenotypic changes, such as mucoid conversion, downregulation of acute virulence pathways, and emergence of hypermutator phenotypes that facilitate rapid adaptation. Persistent cells, a specialized subpopulation characterized by metabolic dormancy and antibiotic tolerance, further complicate eradication efforts. The dynamic interplay between host environment and microbial evolution underlies the heterogeneity of CF lung infections and presents significant challenges for treatment. Elucidating the molecular mechanisms driving persistence, hypermutability, and biofilm resilience is critical for the development of effective therapeutic strategies targeting chronic P. aeruginosa infections in CF. Full article

Cystic Fibrosis (CF) is a common genetic disease in the United States, resulting from mutations in the Cystic Fibrosis transmembrane conductance regulator (cftr) gene. CFTR modulators, particularly Elexacaftor/Tezacaftor/Ivacaftor (ETI), have significantly improved clinical outcomes for patients with CF. However, many CFTR mutations are not eligible for CFTR modulator therapy due to their rarity. In this study, we report that a patient carrying rare complex CFTR mutations, c.1680-877G>T and c.3067_3072delATAGTG, showed positive clinical outcomes after ETI treatment. We demonstrate that ETI was able to increase the expression of CFTR harboring c.3067_3072delATAGTG in a heterologous system. Importantly, patient-derived nasal epithelial cells in an air–liquid interface (ALI) culture showed improved CFTR function following ETI treatment. These findings supported the initiation of ETI with the patient. Retrospective studies have suggested that the patient has shown small but steady improvement over the past two years in several clinical metrics, including lung function, body mass index (BMI), and sweat chloride levels. Our studies suggest that ETI could be beneficial for patients carrying c.3067_3072delATAGTG. Full article

Cystic fibrosis (CF), a severe genetic disorder stemming from mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene, is characterized by a complex interplay of chronic inflammation and heightened oxidative stress, resulting in substantial patient morbidity. The diverse array of CFTR mutations, categorized into seven distinct classes based on their functional impact on the CFTR protein, presents a significant obstacle to effective therapeutic intervention. While CFTR modulator therapies offer clinical benefits, their applicability is restricted to specific mutation classes, leaving a considerable portion of the CF patient population with unmet therapeutic needs. This review provides a critical analysis of the intricate role of oxidative stress in CF, meticulously examining its origins, mechanistic pathways and downstream pathological consequences, with particular emphasis on lipid peroxidation (LPO). It elucidates the nuanced connection between LPO and inflammatory processes driven by cellular stressors such as endoplasmic reticulum dysfunction, mitochondrial impairment and persistent bacterial infections. Furthermore, it evaluates the current landscape of therapeutic proposals targeting oxidative stress, including antioxidant interventions, and explores the potential of microRNAs (miRNAs) as novel targets. This review aims to synthesize existing research to provide a comprehensive understanding of oxidative stress involvement in CF pathogenesis while critically appraising the advantages and limitations of current antioxidant therapeutic strategies. Full article

Defective CFTR (cystic fibrosis transmembrane conductance regulator) is pathognomonic for cystic fibrosis (CF), which is characterized by an accumulation of tenacious secretions in pulmonary airways, as well as by abnormal ductal secretions in other organs, including the pancreas and prostate. The advent of CFTR modulating therapies has markedly improved the clinical status and survival of CF patients, primarily attributable to improved lung function. Previous publications reported that a decline in CFTR function was associated with a decline in activity and expression of the enzyme N-acetylgalactosamine-4-sulfatase (Arylsulfatase B; ARSB). ARSB removes 4-sulfate groups from N-acetylgalactosamine 4-sulfate residues and is required for the degradation of chondroitin 4-sulfate (chondroitin sulfate A) and dermatan sulfate, two sulfated glycosaminoglycans which accumulate in cystic fibrosis. Declines in both ARSB and in CFTR have been associated with the development of malignancies, including prostate malignancy. The experiments in this report show that similar effects on invasiveness are present when either CFTR or ARSB is inhibited in human prostate epithelial cells, and these effects resemble findings detected in malignant prostate tissue. The effects of CFTR inhibition are reversed by treatment with recombinant human ARSB in prostate cells. These results suggest that treatment by rhARSB may benefit patients with cystic fibrosis and prostate cancer. Full article

Elexacaftor–tezacaftor–ivacaftor (ETI) has shown clinical and spirometric benefits in cystic fibrosis (CF). CT remains a vital tool for diagnosing and monitoring structural lung disease. This study aimed to assess the evolution of lung disease, as evaluated through CT, in adults with CF after at least one year of ETI treatment. This ambispective observational analysis assessed lung CT scans performed before initiating ETI and after at least one year of treatment, using the modified Bhalla scoring system. For those patients with an earlier CT scan, a pre-treatment phase analysis was performed. Epidemiological, clinical, and functional parameters were evaluated. Results: Sixty-two patients were included (35 males, median age 30.4 ± 7.87 years). After at least one year of ETI, significant improvements were observed in the global CT Bhalla score (12.2 ± 2.8 vs. 14.0 ± 2.8), peribronchial thickening (1.4 ± 0.6 vs. 1.0 ± 0.4), and mucus plugging (1.6 ± 0.7 vs. 0.8 ± 0.6) (p < 0.001). Spirometry parameters increased significantly: the percentage of the predicted forced expiratory volume in the first second (ppFEV₁) increased from 66.5 ± 19.8 to 77.0 ± 20.4 (p = 0.005) and forced vital capacity (ppFVC) from 80.6 ± 16.4 to 91.6 ± 14.1 (p < 0.001). Additionally, body mass index showed a significant increase. A moderate correlation was found between the Bhalla score and spirometry results. In the pre-treatment phase (n = 52), mucus plugging demonstrated a significant worsening, whereas global CT score, other subscores, and spirometry did not change significantly. Conclusions: In adults with CF, after at least one year of ETI, a significant improvement in structural lung disease was achieved, as reflected by the CT Bhalla score. Full article

Background/Objectives: Cystic Fibrosis (CF) is an autosomal recessive genetic disorder caused by variants in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein. Recently, a targeted therapy for CF has been developed, represented by the CFTR modulators that enhance or restore the function of the CFTR protein. The most recent is the combination of three modulators, Elexacaftor, Tezacaftor, and Ivacaftor (ETI). This study describes the presentation, management, and follow-up of tracheal diverticulum (TD) in pwCF receiving ETI therapy. Methods: This retrospective study included people with CF (pwCF) on ETI treatment and followed up in two CF Italian centers who developed an asymptomatic TD, diagnosed incidentally at chest CT scan. Results: Among 268 pwCF receiving ETI, three (1.19%) were diagnosed with TD identified after chest CT and were included in this study. Endoscopic confirmation was obtained in one patient. All patients were on inhaled colistimethate, two of them for chronic Pseudomonas aeruginosa colonization, and one undergoing eradication therapy. Conclusions: TD may be identified in chest CT obtained in pwCF in treatment with ETI. Further studies and a longer follow up are needed to confirm these findings. Full article

Cystic Fibrosis (CF) is a life-shortening, multi-organ disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. Prominent clinical features of CF take place in the lung, hallmarked by cycles of bacterial infection and a dysfunctional inflammatory airway response, leading to eventual respiratory failure. Bidirectional crosstalk between epithelial cells, leukocytes (e.g., neutrophils, macrophages) and bacteria via release of intra-cellular mediators is key to driving inflammation in CF airways. In recent years, a highly effective combination of therapeutics targeting the CFTR defect have revolutionized treatment in CF. Despite these advancements and due to the complexity of the immune response in the CF airway, the full impact of highly effective modulator therapy (HEMT) on airway inflammation is not fully determined. This review provides the evidence to date on crosstalk mechanisms between host epithelium, leukocytes and bacteria and examines the effect of HEMT on both soluble and membrane-derived immune mediators in clinical samples. The varied effects of HEMT on expression of key proteases, cytokines and extracellular vesicles (EVs) in relation to clinical parameters is assessed. Advances in treatment with HEMT have shown potential in dampening the chronic inflammatory response in CF airways. However, to fully quell inflammation and maximize lung tissue resilience, further interventions may be necessary. Exploring the effects of HEMT on key immune mediators paves the way for identifying new anti-inflammatory approaches targeting host immune cell interactions, such as EV-directed lung therapies. Full article

Background: Cystic Fibrosis is an inherited disorder caused by mutations in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene, encoding a chloride and bicarbonate channel widely expressed in epithelia. Loss of CFTR function leads to dehydration of the epithelium surface with thicker mucus secretions from tissues. The lungs, pancreas, liver, intestines, and sweat glands are the most common affected organs. However, pulmonary disease remains the main cause of morbidity and mortality. Fortunately, elexacaftor/tezacaftor/ivacaftor (ETI) therapy is showing unprecedented clinical benefits in patients with Cystic Fibrosis (CF) carrying at least one F508del mutation in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene. However, almost 35% of the CF population living in the Mediterranean area still lacks effective CFTR modulator therapies because of the elevated incidence of patients with (pw)CF harboring CFTR rare mutations (RMs), different from F508del. Methods: Twenty-three pwCF harboring RM including the N1303K underwent off-label ETI treatment for 6-12 months. Respiratory function in terms of FEV1 and FVC was measured after 3, 6, and 12 months of treatment. In addition, we analyzed sweat chloride concentration, body mass index (BMI), and quality of life before and after treatment. Possible adverse effects were recorded. Results: All patients included in this off-label program displayed a substantial improvement in respiratory function. In particular, patients carrying the N1303K mutation showed an improvement in FEV1 and FVC similar to that observed in subjects harboring the F508del mutation, although sweat chloride concentration was not significantly decreased. No severe adverse effect was reported. Conclusions: This study strengthens the clinical efficacy of ETI in pwCF harboring the N1303K and other CFTR rare variants. Since these CFTR RMs have not been approved for ETI therapy in Europe, this study may promote the inclusion of these variants in the list of CFTR mutations responsive to ETI. Full article

Cystic fibrosis (CF) is a recessive genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) protein, a chloride and bicarbonate channel localized on the plasma membrane of epithelial cells. Over the last three decades, high-throughput screening assays have been extensively employed in identifying drugs that target specific defects arising from CFTR mutations. The two main categories of such compounds are potentiators, which enhance CFTR gating by increasing the channel’s open probability, and correctors, which improve CFTR protein folding and trafficking to the plasma membrane. In addition to these, other investigational molecules include amplifiers and stabilizers, which enhance the levels and the stability of CFTR on the cell surface, and read-through agents that promote the insertion of correct amino acids at premature termination codons. Currently, four CFTR modulators are clinically approved: the potentiator ivacaftor (VX-770), either as monotherapy or in combination with the correctors lumacaftor (VX-809), tezacaftor (VX-661), and elexacaftor (VX-445). Among these, the triple combination VX-445/VX-661/VX-770 (marketed as Trikafta^® in the US and Kaftrio^® in Europe) has emerged as the most effective CFTR modulator therapy to date, demonstrating significant clinical benefits in phase III trials for patients with at least one F508del CFTR allele. Despite these advancements, the mechanisms of action and binding sites of these modulators on CFTR have only recently begun to be elucidated. A deeper understanding of these mechanisms could provide essential insights for developing more potent and effective modulators, particularly in combination therapies. This narrative review delves into the mechanism of action, binding sites, and combinatorial effects of approved and investigational CFTR modulators, highlighting ongoing efforts to broaden therapeutic options for individuals with CF. Full article

Background: The potentiator VX-770 (ivacaftor) has been approved as a monotherapy for over 95 cystic fibrosis (CF)-causing variants associated with gating/conductance defects of the CF transmembrane conductance regulator (CFTR) channel. However, despite its therapeutic success, VX-770 only partially restores CFTR activity for many of these variants, indicating they may benefit from the combination of potentiators exhibiting distinct mechanisms of action (i.e., co-potentiators). We previously identified LSO-24, a hydroxy-1,2,3-triazole-based compound, as a modest potentiator of p.Arg334Trp-CFTR, a variant with a conductance defect for which no modulator therapy is currently approved. Objective/Methods: We synthesized a new set of LSO-24 structure-based compounds, screened their effects on p.Arg334Trp-CFTR activity, and assessed the additivity of hit compounds to VX-770, ABBV-974, ABBV-3067, and apigenin. After validation by electrophysiological assays, the most promising hits were also assessed in cells expressing other variants with defective gating/conductance, namely p.Pro205Ser, p.Ser549Arg, p.Gly551Asp, p.Ser945Leu, and p.Gly1349Asp. Results: We found that five compounds were able to increase p.Arg334Trp-CFTR activity with similar efficacy, but slightly greater potency promoted by LSO-150 and LSO-153 (EC₅₀: 1.01 and 1.26 μM, respectively). These two compounds also displayed a higher rescue of p.Arg334Trp-CFTR activity in combination with VX-770, ABBV-974, and ABBV-3067, but not with apigenin. When tested in cells expressing other CFTR variants, LSO-24 and its derivative LSO-150 increased CFTR activity for the variants p.Ser549Arg, p.Gly551Asp, and p.Ser945Leu with a further effect in combination with VX-770 or ABBV-3067. No potentiator was able to rescue CFTR activity in p.Pro205Ser-expressing cells, while p.Gly1349Asp-CFTR responded to VX-770 and ABBV-3067 but not to LSO-24 or LSO-150. Conclusions: Our data suggest that these new potentiators might share a common mechanism with apigenin, which is conceivably distinct from that of VX-770 and ABBV-3067. The additive rescue of p.Arg334Trp-, p.Ser549Arg-, p.Gly551Asp-, and p.Ser945Leu-CFTR also indicates that these variants could benefit from the development of a co-potentiator therapy. Full article

Introduction: Cystic fibrosis transmembrane conductance regulator (CFTR) modulators have greatly improved outcomes in persons with CF (pwCF); however, there is still significant heterogeneity in clinical responses, particularly with regard to respiratory infection and inflammation. Exogenous administration of ketones has profound systemic anti-inflammatory effects and produces several nutrient-signaling and metabolic effects that may benefit multiple organ systems affected in pwCF. This pilot study was designed to determine the feasibility of administration of a ketone monoester (KME) to increase circulating D-beta hydroxybutyrate concentrations (D-βHB) and to improve subjective measures of CF-specific quality of life and markers of inflammation in serum and sputum in adults with CF. Methods: Fourteen participants receiving modulator therapy were randomized to receive either KME (n = 9) or placebo control (PC, n = 5) for 5–7 days during hospitalization for treatment of acute pulmonary exacerbation or as outpatients under standard care. Results: The KME was well tolerated, with only mild reports of gastrointestinal distress. D-βHB concentrations increased from 0.2 ± 0.1 mM to 1.6 ± 0.6 mM in the KME group compared to 0.2 ± 0.0 to 0.3 ± 0.1 in the PC group (p = 0.011) within 15 min following consumption and remained elevated, relative to baseline, for over 2 h. Pulmonary function was not altered after single- or short-term KME administration, but participants in the KME group self-reported higher subjective respiratory scores compared to PC in both cases (p = 0.031). Plasma inflammatory markers were not statistically different between groups following the short-term (5–7 d) intervention (p > 0.05). However, an exploratory analysis of plasma pre- and post-IL-6 concentrations was significant (p = 0.028) in the KME group but not PC. Sputum IFNγ (p = 0.057), IL-12p70 (p = 0.057), IL-1β (p = 0.100), IL-15 (p = 0.057), IL-1α (p = 0.114), and MPO (p = 0.133) were lower in the KME group compared to PC but did not achieve statistical significance. Conclusions: With the emerging role of exogenous ketones as nutrient signaling molecules and mediators of metabolism, we showed that KME is well tolerated, increases circulating D-βHB concentrations, and produces outcomes that justify the need for large-scale clinical trials to investigate the role of KME on whole-body and tissue lipid accumulation and inflammation in pwCF. Full article