Acad Radiol. 2025 Jul 10:S1076-6332(25)00622-1. doi: 10.1016/j.acra.2025.06.042. Online ahead of print.

ABSTRACT

RATIONALE AND OBJECTIVES: Hyperpolarized 129Xe magnetic resonance imaging (MRI) can sensitively detect subtle abnormalities in subjects with pulmonary disease. In this work, we assess lung disease progression and treatment response to Lumacaftor/Ivacaftor in patients with cystic fibrosis.

METHODS: 18 cystic fibrosis (CF) patients underwent a longitudinal study: nine subjects (8.7±2.4years, 3M/6F) initiated lumacaftor/ivacaftor therapy (48±51days post-Visit 1), and 9 (15.3±4.3years, 5M/4F) served as controls. Spirometry, multiple breath washout (Lung Clearance Index, LCI2.5), and 129Xe MRI were acquired at baseline, short-term (6±3months), and long-term (15±4months) follow-ups. Changes in spirometry measurements, LCI, ventilation defect percentage (VDP), and defect distribution index (DDI) assessed by 129Xe MRI, were compared between groups using non-parametric tests.

RESULTS: The control group was significantly older (P=0.0028) and trended toward higher initial VDP (14.7±8.1% vs 6.9±6.0%) and DDI (14.4±24.7 vs 4.7±4.3). Baseline spirometry and LCI showed no differences between groups. In the treatment group, VDP and DDI remained stable after treatment (ΔVDP12= -0.56±2.1%, ΔDDI12= 1.1±4.0) but the change was significantly lower than in controls (ΔVDP12= 2.75±2.82%, P=0.018; DDI12= 8.88±7.42, P=0.007). From Visit-2 to Visit-3, VDP increased significantly in the treatment group (ΔVDP23 = 3.33±2.79%, P=0.025) versus controls (ΔVDP23= -1.7±4.8%). No significant changes occurred in spirometry or LCI.

CONCLUSION: 129Xe MRI demonstrated high sensitivity in detecting functional changes between pediatric CF patients on and off modulator therapy. In the short term, 129Xe ventilation measures remained stable with modulator therapy and demonstrated declines in the 2 years following. These findings highlight 129Xe MRI's potential as a valuable clinical tool for monitoring lung function and disease progression, even with small cohorts of patients.

PMID:40645890 | DOI:10.1016/j.acra.2025.06.042

J Cyst Fibros. 2025 Jul 11:S1569-1993(25)01527-9. doi: 10.1016/j.jcf.2025.07.004. Online ahead of print.

ABSTRACT

BACKGROUND: With evolving Cystic Fibrosis (CF) phenotypes resulting from changes to clinical management, healthier dietary practices are warranted for many people with CF. Whilst diet composition is reported, diet quality data is lacking in CF. This study aims to evaluate dietary intakes and diet quality in adults with CF via guideline comparison and a validated diet quality index.

METHODS: Cross-sectional study of Irish adults with CF. Demographic questionnaires and three-day food diaries were completed. Healthy Eating Index - 2020 (HEI-2020) assessed diet quality. Data was statistically analysed in SPSS®.

RESULTS: Of n = 68 participants (female: 58.8 %, age: 35.2 ± 10.1 years, FEV1%: 77.4 ± 25.1 %), 36.8 % were overweight/obese and 77.6 % pancreatic insufficient. While median (interquartile range) percentage estimated average requirement (EAR) was 110.1 (45.3) %, 50.0 % of participants were below CF energy requirements (110 % EAR). Mean percentage total energy intake (%TEI) protein (18.0 ± 3.9 %) aligned to dietary reference values (DRV). %TEI carbohydrates (44.1 ± 6.5 %) was below, and %TEI fat (37.1 ± 5.4 %), saturated fat (14.1 ± 3.3 %) and sugar (17.4 ± 5.6 %) exceeded DRV. Median vitamin A intake was adequate [936.6 (1005.2) µg], but vitamin D [3.6 (4.3) µg], E (9.6 ± 5.2 mg) and K1 [31.1 (71.2) µg] intakes were insufficient without supplementation. Regarding Irish healthy eating guidelines, 95.6 % of participants overconsumed energy-dense nutrient poor (EDNP) foods, with 76.5 % below vegetables, salad and fruit intake guidelines. Participants' mean HEI-2020 score (0-100) was 59.3 ± 12.4.

CONCLUSION: Findings indicate suboptimal diet quality. Despite reliance on EDNP foods, many did not achieve energy targets. Moving forward, emphasis on diet quality is of paramount importance to improve overall health in people with CF.

PMID:40645855 | DOI:10.1016/j.jcf.2025.07.004

Biochem Pharmacol. 2025 Jul 9:117127. doi: 10.1016/j.bcp.2025.117127. Online ahead of print.

ABSTRACT

Although remarkable rescue has been achieved for treatment of Cystic Fibrosis (CF) by the combination of two correctors (VX-661, VX-445) and one potentiator (VX-770), the stability and trafficking defects induced by the most common mutation, F508del, are not completely reverse. Therefore, more effective CFTR correctors are still needed. We employed in silico and molecular modelling approaches to design and probe the binding site of novel series of CFTR correctors (a-c). Structure-based studies allowed us to design and synthesize novel class I (b series) and class II (a series) modulators. Thus, class I modulator activity relies on interactions with Met152, Phe81, Phe191, Trp361. The design of class II corrector could be managed via NBD2-ligand H-bonds, involving Gln1291 or Val1288. Furthermore, c compounds were proposed featuring putative dual corrector ability (2c) and class II corrector behavior (1c). Functional measurements in F508del-CFTR CFBE cells and primary nasal epithelial cells demonstrated that eight of fourteen compounds acted as CFTR correctors and the F508del-CFTR rescue was comparable to the level measured after VX-809 or VX-445 treatment in CFBE cells. Through rational selection based on molecular docking studies and mechanisms of action, we showed that combination of compounds (7a+1b and 2a+2b) targeting distinct domains of CFTR, can additively/synergistically rescue F508del-CFTR function in both CFBE cell line and primary nasal cells. Our study demonstrated that in silico and in vitro approaches to develop and investigate the mechanism of action of novel CFTR correctors could be a tool to optimize the combination correctors therapy to synergistically rescue mutated CFTR.

PMID:40645602 | DOI:10.1016/j.bcp.2025.117127

Respir Med. 2025 Jul 9:108238. doi: 10.1016/j.rmed.2025.108238. Online ahead of print.

ABSTRACT

Cystic Fibrosis (CF) is an autosomal recessive genetic disease caused by variants in both copies of the CF transmembrane conductance regulator (CFTR) gene, with F508del (p.Phe508del) being the most common variant. While CFTR modulators have revolutionized treatment, their efficacy is mutation-specific, leaving patients with rare variants like N1303K without approved therapeutic options. We present the case of a 21-year-old female with severe CF due to homozygosity for the N1303K variant. Faced with rapid clinical decline and ineligibility for approved therapies, a forskolin-induced swelling assay (FIS) on her intestinal organoids demonstrated a significant response to the triple CFTR modulator therapy Elexacaftor/Tezacaftor/Ivacaftor (ETI). Off-label ETI was initiated, resulting in improved pulmonary function, reduced exacerbations, and better quality of life. Despite initial progress with ETI, the patient experienced three hospitalizations over five months due to severe exacerbations, during which Burkholderia cepacia complex was identified for the first time, while the pre-existing chronic infection with Candida parapsilosis persisted. These infections were managed with personalized antimicrobial strategies, including inhaled meropenem and inhaled amphotericin, alongside ETI, leading to sustained clinical stability during an 8-month follow-up. This case highlights the potential of organoid-based testing to guide personalized CFTR modulator therapy for rare variants and underscores the importance of individualized antimicrobial strategies in addressing the complexities of CF. Expanding regulatory approval for modulators like ETI to include rare variants is essential for equitable CF care.

PMID:40645349 | DOI:10.1016/j.rmed.2025.108238

EBioMedicine. 2025 Jul 10;118:105848. doi: 10.1016/j.ebiom.2025.105848. Online ahead of print.

ABSTRACT

BACKGROUND: Cystic fibrosis is caused by mutations of the cystic fibrosis transmembrane conductance regulator, CFTR, an epithelial anion transport protein, responsible for, inter alia, sputum viscoelasticity in the lung. We previously identified the TNF receptor superfamily 1A TNFRSF1A (TNFR1) as a genetic modifier of CFTR function and disease severity in the CF twin and sibling study population. We aimed to replicate our findings in independent cohorts, assess the role of TNFR1 for patient survival and identify functional changes associated with TNFR1 polymorphisms.

METHODS: We incorporated data from three independent long-term mono- and multicentric cohorts of people with cystic fibrosis (pwCF) to confirm the previously described association of TNFR1 with CFTR function and to extend our study to include survival data for our local cohort and a pan-European cohort of pwCF. We studied TNFR1 transcripts obtained from primary airway epithelia grown as air-liquid interface cultures to address possible mechanisms involved in up-stream and down-stream effects of TNFR1.

FINDINGS: Survival differed by more than a decade when comparing carriers of contrasting TNFR1 genotypes among unrelated pwCF as well as among CF siblings pairs. The presence of the TNFR1 transcript variant TNFR1delEx2 in primary airway epithelia was associated with TNFR1 genotype.

INTERPRETATION: The association of the TNFR1 transcript variant TNFR1delEx2 associates with the TNFR1 genotype, possibly mediating the genotype-survival association we found regarding TNFR1 genotype and patient survival in cystic fibrosis.

FUNDING: Supported by the German Ministry for Education and Research (BMBF) (82DZL009B1 to MAM and 82DZL002A1, to GH, BT, AMD, FS) and the Mukoviszidose Institut gGmbH (MI-2002, to LN, AMD, FS).

PMID:40645008 | DOI:10.1016/j.ebiom.2025.105848

J Womens Health (Larchmt). 2025 Jul 11. doi: 10.1177/15409996251359820. Online ahead of print.

ABSTRACT

Background: Sickle cell disease (SCD) is associated with high-risk pregnancy and low rates of hormonal contraception use. Intersectional vulnerabilities among individuals with SCD in the United States raise historically and socially contingent questions about tubal sterilization (TS), yet immediate postpartum TS rates among individuals with SCD remain unknown. Methods: Using the 2012-2019 National Inpatient Sample, we conducted a repeated cross-sectional study to estimate the rate of TS among delivery hospitalizations for people with SCD, without SCD (non-SCD), Black people with and without SCD, and people with cystic fibrosis (CF). Logistic regression models estimated the adjusted odds of TS between SCD and comparison groups. Interaction analyses examined whether severe maternal morbidity (SMM) modified the association between TS and SCD. Results: After adjusting for patient and hospital characteristics, SCD had higher odds of TS compared with non-SCD deliveries (adjusted odds ratio [aOR] = 1.38 [1.06, 1.79]). Among deliveries coded with Black race, SCD deliveries had higher odds of TS than non-SCD deliveries (aOR = 1.42 [1.06, 1.90]). There was no difference in the odds of TS between SCD and CF deliveries (aOR = 1.0 [0.51, 2.24]). SMM more than doubled the odds of TS in SCD deliveries (interaction: aOR = 2.34 [1.57, 3.47]; aOR = 2.14 [1.40, 3.24] in Black race deliveries). Conclusion: Even after accounting for patient and hospital characteristics, people with SCD have higher odds of immediate postpartum TS compared with comparison groups. Possibly, SMM severity, patient preference, or clinician recommendations inform this finding. SMM is three to seven times more common in SCD than non-SCD pregnancies and may be a modifiable risk factor for TS in SCD deliveries.

PMID:40643898 | DOI:10.1177/15409996251359820

J Pediatr Psychol. 2025 Jul 11:jsaf035. doi: 10.1093/jpepsy/jsaf035. Online ahead of print.

ABSTRACT

OBJECTIVE: Few reviews have evaluated culturally targeted interventions for youth who have chronic health conditions. This systematic review aimed to describe health, psychosocial, behavioral, and sociocultural outcomes of culturally targeted interventions among children from racially and ethnically minoritized backgrounds who have a chronic condition in the United States.

METHODS: A systematic literature review was conducted (January 1, 2013 through July 1, 2023). We reviewed randomized and non-randomized controlled clinical trials investigating culturally targeted, psychologist-involved interventions among children (ages 0-18 years) from racially/ethnically minoritized backgrounds in the United States with obesity, asthma, diabetes, sickle cell disease, cancer, cystic fibrosis, epilepsy, lupus, arthritis, and human immunodeficiency virus. Studies were included that compared culturally targeted interventions to non-targeted interventions or no intervention. Searches were conducted in PubMed, Embase, Central, and PsycINFO. Covidence was used for data screening, assessment, and extraction. Risk of bias was assessed with the Cochrane risk of bias version 2 tool. Extracted outcome variables included child health and healthcare utilization, and child and parent psychosocial, behavioral, and sociocultural outcomes.

RESULTS: The review included one study evaluating the effectiveness of the Physician Asthma Care Education (PACE) intervention compared to PACE Plus, a culturally enhanced version, among African American and Latino youth with asthma. Participants included 112 primary care providers and 867 pediatric patients.

CONCLUSIONS: Health, psychosocial/behavioral, and sociocultural outcomes of culturally targeted interventions for racially and ethnically minoritized youth with chronic health conditions in the United States are unknown. Future research should prioritize the development and evaluation of culturally targeted interventions for these populations.

PMID:40641395 | DOI:10.1093/jpepsy/jsaf035

Oncoimmunology. 2025 Dec;14(1):2531113. doi: 10.1080/2162402X.2025.2531113. Epub 2025 Jul 10.

ABSTRACT

Sertraline and indatraline are two antidepressants that function as serotonin reuptake inhibitors and have demonstrated promising anticancer potential, although their precise mechanisms of action remain unclear. Both compounds trigger cholesterol accumulation within lysosomes followed by lysosomal membrane permeabilization, ultimately leading to the activation of immunogenic cell death (ICD). This, in turn, triggers a T cell-mediated adaptive immune response that facilitates significant tumor control.

PMID:40635571 | PMC:PMC12247098 | DOI:10.1080/2162402X.2025.2531113

Eur Respir J. 2025 Jul 10:2500081. doi: 10.1183/13993003.00081-2025. Online ahead of print.

ABSTRACT

Bronchiectasis is a chronic respiratory disease that can lead to a substantial decline in lung function, ultimately leading to a significantly increased risk of morbidity and mortality. Despite the increasing global impact of bronchiectasis, no specific (or licensed) treatment for the disease currently exists, with most available therapies, though beneficial, focusing on symptom management and infection control. In part, the lack of specific treatments for bronchiectasis may be due to a lack of established biomarkers for the disease. Because bronchiectasis varies so widely in its clinical presentation and can be caused by various aetiologies, the establishment of validated biomarkers has proven challenging. However, identifying key biomarkers in bronchiectasis is crucial to developing appropriate diagnosis and management plans, as well as to measuring effective responses to treatment. While there is a multitude of potential biomarkers in bronchiectasis, almost all instances of bronchiectasis are underpinned by chronic neutrophilic inflammation. The imbalance in neutrophil serine proteases (NSPs) and their endogenous inhibitors has been strongly linked to the lung destruction, mucosal-related defects, infection and worsening of clinical outcomes that are frequently observed in bronchiectasis. In this review, we discuss the various biomarkers linked to bronchiectasis, with a specific focus on NSPs as the most validated biomarkers in bronchiectasis, given their marked role in the pathogenesis of the disease. Lastly, we touch on potential therapeutic approaches aimed at reducing NSP activity in bronchiectasis, showing that, to date, indirect NSP inhibition appears to be the strategy that most effectively addresses chronic neutrophilic inflammation in bronchiectasis.

PMID:40639876 | DOI:10.1183/13993003.00081-2025

Am J Physiol Lung Cell Mol Physiol. 2025 Jul 10. doi: 10.1152/ajplung.00279.2024. Online ahead of print.

ABSTRACT

Background: Prostaglandin E2 (PGE2) is a potent stimulator of airway epithelial Cl- secretion. PGE2 can stimulate CFTR-independent Cl- secretion from Calu-3 submucosal gland cells, whereas human bronchial epithelial (HBE) cells require CFTR. Aim: Determine the mechanism(s) driving CFTR-independent PGE2-stimulated Cl- secretion in Calu-3 cells. Methods: Short-circuit current (Isc) was measured in Calu-3, HBE, and duodenal enteroids in Ussing Chambers. mRNA expression and intracellular Ca2+ (Ca2+i) was determined by qPCR and Fura-Red imaging, respectively. Results: In Calu-3 and HBE cells, PGE2-stimulated Isc was reduced by bilateral and basolateral-only removal of extracellular Ca2+ (Ca2+e), but not by inhibition of protein kinase A (PKA), inositol 1,4,5-triphosphate (IP3), or Ca2+i stores. Duodenal enteroids utilized PKA, IP3, Ca2+i and Ca2+e. EP receptor mRNA expression and functional measurements indicated EP4 receptor dominance in Calu-3 cells. EP4 receptor agonist CAY-10598 (CFTRinh-172, glibenclamide) increased Ca2+i and Isc was driven by Ca2+-activated Cl- secretion. Isc was inhibited by dasatinib, wortmannin, and GSK650394, indicating involvement of Src, phosphoinositol phosphate (PI3K), serum glucocorticoid kinase 1 (SGK1). CFTR-independent CAY-10598-stimulated Isc was mediated by apical Ca2+ release-activated Ca2+ channels (CRAC), P2X receptors, and basolateral TRPV channels. Conclusions: Calu-3 and HBE cells predominantly utilize EP4 receptors and Ca2+e-mediated signaling for PGE2-stimulated Cl- secretion. However, Calu-3 cells leverage apical Ca2+ entry through CRAC and P2X receptors, together with basolateral TRPV activation, Src, PI3K, and SGK1 signaling, for CFTR-independent Cl- secretion. Gaining insights into means to increase CFTR-independent airway Cl- secretion may identify novel therapies to help ameliorate lung diseases with compromised CFTR function.

PMID:40637447 | DOI:10.1152/ajplung.00279.2024

Pediatr Pulmonol. 2025 Jul;60(7):e71189. doi: 10.1002/ppul.71189.

ABSTRACT

BACKGROUND: When monitoring lung function in patients with Cystic Fibrosis (pwCF) and Primary Ciliary Dyskinesia (pwPCD), nitrogen multiple breath washout (N2MBW) is usually performed before spirometry to prevent forced expiratory maneuvers from altering N2MBW results. The N2MBW may affect spirometry if cooperation decreases after a long period of examination or due to prolonged oxygen inhalation. The equivalence of these concepts has never been investigated in a randomized cross-over trial. We hypothesized that the order of pulmonary function tests (PFTs) would not influence the z-score FEV1.

METHODS: A total of 47 clinically stable outpatients (36 pwCF, 11 pwPCD; 16.7 ± 8.1 years) were randomized into two groups. Each patient underwent N2MBW and spirometry at two consecutive visits (median interval 104 days): Group I: Spirometry followed by N2MBW (A), reversed order at the second visit (B), Group II reversed (B→A).

STATISTICS: For the equivalence test, a change in z-score FEV1 (primary endpoint) ±0.2 and lung clearance index (LCI2.5, secondary endpoint) ±15% was not considered relevant; therefore, changes outside this range were considered an intervention effect in the linear mixed model (p < 0.05).

RESULTS: There was a significant deterioration in z-score FEV1 between the two appointments (period effect: -0.177; p = 0.012). The intervention effect and 95% confidence interval were within the equivalence range in both groups (z-score FEV1: 0.039; -0.0765 to 0.1539, LCI2.5: -0.082; -0.3691 to 0.2054).

DISCUSSION: In our cohort the order of PFTs has no influence on the results suggesting that a greater flexibility in practice is possible without the risk of falsifying results.

TRIAL REGISTRATION: German Clinical Trials Register (No. DRKS00027473).

PMID:40637384 | DOI:10.1002/ppul.71189

Eur Respir Rev. 2025 Jul 9;34(177):240279. doi: 10.1183/16000617.0279-2024. Print 2025 Jul.

ABSTRACT

BACKGROUND: Recent advances in the measurement of physical activity have significantly enhanced the analyses and interpretation in relation to health and well-being. Thus, we sought to revise and expand the 2015 position statement on the measurement of physical activity and provide guidance to clinicians and researchers for measuring physical activity in cystic fibrosis (CF) clinical practice and research.

METHODS: This study was registered with the International Prospective Register of Systematic Review (PROSPERO) database (CRD42022292165). Three databases (Medline, Embase and Cumulative Index to Nursing and Allied Health Literature) were searched for studies investigating the measurement of physical activity and sedentary time in people with CF irrespective of age or duration. The Quality Assessment for Diverse Studies was used to assess methodological concern. A mixed-methods framework synthesis was used to extract, map, chart, categorise and aggregate study findings.

RESULTS: In total, 7439 potentially relevant publications were identified. Following screening of titles and abstracts, 422 full texts were retrieved and assessed for eligibility, with 90 studies included. There was considerable variation in the methods of assessment, data processing and analytical interpretation of data.

CONCLUSION: It is recommended that device-based physical activity metrics are presented as time spent in different intensity categories (e.g., light, moderate and vigorous) and to include sedentary and sleep time. For data analysis, the data resolution should be at least 1 s (minimum 30 Hz) to enable clinical teams to obtain representative categorisation of patients' physical activity patterns. Validated questionnaires (e.g., the Habitual Activity Estimation Scale) offer additional opportunities to assess physical activity, whilst diaries can add context but should be viewed as secondary outcome measurements.

PMID:40633976 | DOI:10.1183/16000617.0279-2024

J Mycol Med. 2025 Jul 3;35(3):101570. doi: 10.1016/j.mycmed.2025.101570. Online ahead of print.

ABSTRACT

Lung abscess is a severe but rare complication among non-transplanted cystic fibrosis (CF) patients. <10 cases have been reported in the international literature so far and bacteria were considered the responsible pathogen. We present two cases of CF adolescent patients who developed lung abscess from A. fumigatus, critically revealed with chest Computed Tomography. In one patient, a thyroid abscess was additionally detected. Both patients presented with fever, not responding to antibiotic therapy. Microbial cultures and molecular testing aided detection of the pathogen. Both patients responded well to antifungal treatment.

PMID:40633482 | DOI:10.1016/j.mycmed.2025.101570

Soc Sci Med. 2025 Jul 4;382:118366. doi: 10.1016/j.socscimed.2025.118366. Online ahead of print.

ABSTRACT

In this article, we explore reproductive decision-making among adults with a rare genetic chronic disease: Cystic Fibrosis (CF). CF is hereditary and can be tested for at various moments in prospective parent's reproductive trajectory, namely before, during or after pregnancy. Based on 15 interviews with persons with CF in Germany who at the time of the interviews were considering having a child, were pregnant, already had a child, or had decided against having a child, we show that people with rare genetic chronic diseases face challenges that go far beyond those all young parents have to deal with. Persons with a rare and chronic disease are forced to anticipate the future beyond the common imagination of what kind of person their child will become. On the one hand, they must take into consideration their own future, that is the state and progress of their own disease. This may limit their ability to actively parent at all and in addition may be negatively impacted by the everyday efforts and struggles of parenting. On the other, as they potentially pass on their disease to their child, they also have to take into account their child's future, its wellbeing and future life. This includes considerations regarding what constitutes a good and liveable life.

PMID:40633407 | DOI:10.1016/j.socscimed.2025.118366

Antimicrob Agents Chemother. 2025 Jul 9:e0046025. doi: 10.1128/aac.00460-25. Online ahead of print.

ABSTRACT

Efflux pumps play multiple roles in bacterial physiology, environmental adaptation, and antibiotic resistance. Early cystic fibrosis (CF) airway infections start with Staphylococcus aureus (SA), often later followed by Pseudomonas aeruginosa (PA) infections. In this study, we have evaluated the role of SA pumps NorA and Tet38 in survival and interaction with PA in CF patients. Data showed a ≥4-log10CFU/mL growth deficit of SA mutants ΔnorA and Δtet38 in an artificial sputum medium (ASM), suggesting NorA and Tet38 contributed to SA growth in CF sputum. In ASM, mucin activated norA but inhibited tet38, while extracellular DNA activated tet38 but inhibited norA, demonstrating complementary roles of mucin and DNA in affecting NorA and Tet38 expression. Furthermore, exposure of SA wild type to PA-excreted molecules affected pump expression; 3,4-dihydroxy-2-heptylquinoline PQS caused an increase in tet38 but a decrease in norA, 4-hydroxy-2-heptylquinoline HHQ caused a decrease in norA and tet38, and pyocyanin PYO caused a modest increase in norA, demonstrating differing additional roles of PA-secreted molecules influencing NorA and Tet38 expression. Evaluation of 48 randomly selected unique CF-associated SA showed that 18.8% were NorA-overexpressors and 10.4% were Tet38-overexpressors. NorA-overexpressors showed a fourfold increase in pyocyanin MIC and ≥16-fold in ciprofloxacin MIC. Furthermore, 89% of NorA-overexpressors carried an insertion of CAAT/ACAA/CTAT at the (-10) motif of the norA promoter, and 62.5% of these were co-isolated with PA.These data showed that SA survives PA killing in CF sputum conditions using sputum key components and PA-specific signal molecules to regulate NorA and Tet38 expression.

PMID:40631986 | DOI:10.1128/aac.00460-25

bioRxiv [Preprint]. 2025 Jul 3:2025.07.03.662950. doi: 10.1101/2025.07.03.662950.

ABSTRACT

Biofilms are communities of bacteria growing within a matrix composed of polymeric substances that act as a barrier to antimicrobials, making bacteria within a biofilm recalcitrant to conventional antibiotic treatments. This lifestyle of bacteria is especially relevant during its pathogenesis, as observed in the case of Pseudomonas aeruginosa infections of immunocompromised patients. However, pico- to nanomolar concentrations of nitric oxide (NO) have been shown to be efficient in triggering P. aeruginosa to disperse from biofilms, suggesting that a combination of NO exposure and antibiotic treatment may help in mitigating infections. In P. aeruginosa , the NosP-NahK two component system, which comprises a NO sensing hemoprotein, NosP, and its associated hybrid histidine kinase, NahK, has been proven to be necessary for NO mediated biofilm dispersal. NahK also has additional roles in biofilm formation, motility, denitrification and virulence, due to its regulation of a global post-transcriptional regulator RsmA. Here, we uncover a novel role of NahK in enhancing the resistance of P. aeruginosa to signaling concentrations of NO. Deletion of nahK sensitizes the strain to nanomolar levels of NO, resulting in DNA damage. Consequently, the SOS stress response pathway is induced, which causes phenotypes such as cell filamentation and cell clustering due to lysis-mediated release of extracellular DNA. Our data also indicate that increased susceptibility of the Δ nahK strain to NO is due to the antagonization of RsmA, and is restricted to amino acid starved media, suggesting that NahK may also have previously unappreciated roles in modulating amino acid metabolism.

IMPORTANCE: P. aeruginosa infections of cystic fibrosis patients can result in increased risk of fatality, necessitating the development of better therapeutic strategies to treat its infections. Here, we present data suggesting that nanomolar concentrations of NO, that are normally used to disperse P. aeruginosa from biofilms, can also sensitize the bacterium to NO mediated DNA damage upon loss of function of the histidine kinase NahK. The resulting SOS stress response may benefit the bacterium through favorable mutations but also poses a risk due to SOS-associated pyocin production through cell lysis. Hence, understanding the molecular mechanisms underlying NahK mediated resistance to NO is important to leverage this regulation and identify novel targets to treat P. aeruginosa infections.

PMID:40631272 | PMC:PMC12236510 | DOI:10.1101/2025.07.03.662950

bioRxiv [Preprint]. 2025 Jul 5:2025.07.02.662194. doi: 10.1101/2025.07.02.662194.

ABSTRACT

Recent advances in cystic fibrosis transmembrane conductance regulator (CFTR) modulator combination therapies have markedly improved survival and quality of life for people with cystic fibrosis (CF). Among these, the elexacaftor-tezacaftor-ivacaftor combination (Trikafta) and its updated formulation, vanzacaftor-tezacaftor-deutivacaftor (Alyftrek), represent major therapeutic milestones. However, emerging reports suggest that Trikafta may contribute to anxiety and depression in some people with CF. In this study, we investigated the neurobehavioral effects of elexacaftor and ivacaftor in mice. Acute administration of elexacaftor elicited anxiety-like behavior, while ivacaftor induced depressive-like behavior. Additionally, we confirmed the presence of Cftr mRNA in the amygdala and hippocampus, brain regions implicated in anxiety and depression. These findings provide preclinical support for the reported mental health side effects experienced by some people with CF and offer new insights into CFTR function within the central nervous system, potentially guiding the development of future CF therapies with improved neuropsychiatric profiles.

PMID:40631217 | PMC:PMC12236610 | DOI:10.1101/2025.07.02.662194

bioRxiv [Preprint]. 2025 Jul 3:2025.07.03.662932. doi: 10.1101/2025.07.03.662932.

ABSTRACT

Oral microbiota are increasingly implicated in chronic inflammatory diseases beyond the mouth, including bronchiectasis, a condition marked by persistent airway inflammation, mucus accumulation, and limited therapeutic options. Among these microbes, commensal Neisseria , typically considered health-associated in the upper airway, are emerging as opportunistic colonists of the inflamed lower airway. However, mechanisms supporting their persistence in this hostile environment, characterized by antibiotic pressure, nutrient limitation, and interspecies competition, remain poorly defined. Here, we show that the prevalent oral commensal Neisseria mucosa exhibits markedly enhanced antibiotic resistance and anoxic growth in a synthetic medium (SCFM2) that mimics sputum from individuals with bronchiectasis. Using genome-wide transposon sequencing (Tn-seq), we identified key genetic determinants of N. mucosa fitness, including pathways for L-lactate catabolism and pyrimidine biosynthesis. Notably, nitrate respiration was also essential for growth, linking use of this inflammation-associated electron acceptor to fitness under oxygen-limited, sputum-like conditions. Loss of nitrate reductase impaired anoxic L-lactate catabolism, reduced competitive fitness against Pseudomonas aeruginosa , and abrogated growth in SCFM2, as well as human saliva-a relevant, nitrate-rich nutrient source in the oral cavity. Furthermore, chemical inhibition of nitrate reductase using tungstate suppressed growth of both N. mucosa and P. aeruginosa in SCFM2, but not in standard media, revealing a context-specific metabolic vulnerability of nitrate-respiring airway pathogens. These findings suggest that inflammation-compatible traits like nitrate respiration, while supporting oral commensalism, may also drive opportunistic expansion in the inflamed airway. Targeting such pathways could offer a non-antibiotic approach to limit oral bacterial persistence in bronchiectasis and other chronic diseases.

IMPORTANCE: Chronic respiratory diseases such as bronchiectasis and cystic fibrosis are marked by persistent infection and inflammation, with oral bacteria increasingly recognized as active contributors. Among these, Neisseria species, typically considered health-associated commensals, are frequently detected in the lower airway, yet little is known about how they persist in this hostile environment. Here, we identify key metabolic pathways that support the survival of Neisseria mucosa in sputum-like media, including nitrate respiration, a pathway closely linked to inflammation. We also show that N. mucosa exhibits enhanced antibiotic resistance under these conditions, underscoring the need to study microbial physiology in host-relevant contexts. Finally, we demonstrate that a selective inhibitor of nitrate respiration suppresses N. mucosa growth in sputum-like but not standard media, revealing a context-specific vulnerability. These findings suggest that targeting inflammation-compatible metabolic pathways may inform new, non-antibiotic approaches for managing chronic respiratory diseases.

PMID:40631094 | PMC:PMC12236520 | DOI:10.1101/2025.07.03.662932

bioRxiv [Preprint]. 2025 Jul 4:2025.07.03.663093. doi: 10.1101/2025.07.03.663093.

ABSTRACT

Nearly 80% of cystic fibrosis patients are affected by persistent lung infections, with Pseudomonas aeruginosa being one of the major culprits. Treatment of P. aeruginosa is further complicated by its ability to form biofilms. Anionic compounds within the biofilm and thick cystic fibrosis mucus interact with cationic antimicrobials, hindering treatment efficacy. In this study, we investigated the treatment of lung infections by delivering antimicrobials via polyelectrolyte surfactants that are composed of an anionic poly(alkylacrylic acid) backbone with grafted polyetheramine pendent chains. When combined with cationic antimicrobials, they self-assemble into nanoparticles via electrostatic interactions. We assessed the role of backbone chemistry and graft density on nanoparticle physical properties and evaluated the antimicrobial activity of these formulations against planktonic and biofilm cultures of P. aeruginosa strains derived from clinical isolates. All synthesized polyelectrolyte surfactants demonstrated high levels of antimicrobial encapsulation, with the extent of drug bound corresponding to the calculated hydrophilic-lipophilic balance values. We observed significantly increased antimicrobial activity against planktonic cultures using nanoformulations containing one of the polyelectrolyte surfactants, PMAA-g-10%J. In contrast, all tested nanoformulations retained, but did not increase, activity against biofilms. By monitoring membrane potentials and nanoparticle uptake, it was found that the nanoparticles directly associate with the bacterial cell membranes, which may enhance drug delivery and underlie the improved activity against the planktonic bacteria. In conclusion, we provide a proof of concept for the design of polyelectrolyte surfactants for the nanoencapsulation and delivery of cationic drug cargoes against P. aeruginosa infections.

PMID:40631083 | PMC:PMC12236493 | DOI:10.1101/2025.07.03.663093

bioRxiv [Preprint]. 2025 Jul 5:2025.07.02.662792. doi: 10.1101/2025.07.02.662792.

ABSTRACT

Cystic Fibrosis (CF) is a monogenic genetic disease caused by mutations in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) chloride/bicarbonate channel, which is expressed in certain epithelia cells. Current therapies focus on restoring CFTR function but many gut-related pathologies persist, highlighting the need for complementary treatments to improve the quality of life of patients living with CF. In this study, we use Drosophila melanogaster as a model to investigate the gut-specific effects of Cftr loss. We demonstrate that enterocyte-specific knockdown of Cftr in flies recapitulates several CF pathologies, including reduced intestinal motility, nutrient malabsorption, and decreased energy stores. Using single-nuclei RNA sequencing (snRNA-seq), we identify significant transcriptional changes in the CF model gut, including the upregulation of acetylcholine esterase (Ace, human AChE), which leads to reduced cholinergic signaling. Cholinergic signaling has been shown to affect CFTR function but this is the first time CFTR loss of function has been shown to alter cholinergic signaling. Functional assays confirm that cholinergic sensitivity is diminished in CF guts and restoring cholinergic signaling via Ace knockdown rescues multiple CF-associated phenotypes. Furthermore, we identify the transcription factor Forkhead (Fkh), the Drosophila homolog of human FOXA1/FOXA2, which is known to be a positive regulator of Cftr in the intestine, as a positive regulator of Ace expression in CF guts. This study establishes the Drosophila gut as a powerful model to investigate CF pathogenesis, genetic modifiers, and identifies Ace and Fkh as genetic modifiers. This work also suggests that enhancing cholinergic signaling may represent a viable therapeutic strategy for gastrointestinal manifestations of CF.

PMID:40631082 | PMC:PMC12236621 | DOI:10.1101/2025.07.02.662792