Microbiol Spectr. 2022 Jun 23:e0100622. doi: 10.1128/spectrum.01006-22. Online ahead of print.

ABSTRACT

Chronic colonization by Pseudomonas aeruginosa is critical in cystic fibrosis (CF) and other chronic lung diseases, contributing to disease progression. Biofilm growth and a propensity to evolve multidrug resistance phenotypes drastically limit the available therapeutic options. In this perspective, there has been growing interest in evaluating combination therapies, especially for drugs that can be administered by nebulization, which allows high drug concentrations to be reached at the site of infections while limiting systemic toxicity. Here, we investigated the potential antibiofilm activity of N-acetylcysteine (NAC) alone and in combination with colistin against a panel of P. aeruginosa strains (most of which are from CF patients) and the transcriptomic response of a P. aeruginosa CF strain to NAC exposure. NAC alone (8,000 mg/L) showed a limited and strain-dependent antibiofilm activity. Nonetheless, a relevant antibiofilm synergism of NAC-colistin combinations (NAC at 8,000 mg/L plus colistin at 2 to 32 mg/L) was observed with all strains. Synergism was also confirmed with the artificial sputum medium model. RNA sequencing of NAC-exposed planktonic cultures revealed that NAC (8,000 mg/L) mainly induced (i) a Zn2+ starvation response (known to induce attenuation of P. aeruginosa virulence), (ii) downregulation of genes of the denitrification apparatus, and (iii) downregulation of flagellar biosynthesis pathway. NAC-mediated inhibition of P. aeruginosa denitrification pathway and flagellum-mediated motility were confirmed experimentally. These findings suggested that NAC-colistin combinations might contribute to the management of biofilm-associated P. aeruginosa lung infections. NAC might also have a role in reducing P. aeruginosa virulence, which could be relevant in the very early stages of lung colonization. IMPORTANCE Pseudomonas aeruginosa biofilm-related chronic lung colonization contributes to cystic fibrosis (CF) disease progression. Colistin is often a last-resort antibiotic for the treatment of such P. aeruginosa infections, and it has been increasingly used in CF, especially by nebulization. N-acetylcysteine (NAC) is a mucolytic agent with antioxidant activity, commonly administered with antibiotics for the treatment of lower respiratory tract infections. Here, we show that NAC potentiated colistin activity against in vitro biofilms models of P. aeruginosa strains, with both drugs tested at the high concentrations achievable after nebulization. In addition, we report the first transcriptomic data on the P. aeruginosa response to NAC exposure.

PMID:35735984 | DOI:10.1128/spectrum.01006-22

Drug Des Devel Ther. 2022 Jun 16;16:1865-1883. doi: 10.2147/DDDT.S214174. eCollection 2022.

ABSTRACT

SMA (5q SMA) is an autosomal recessive neuromuscular disease with an estimated incidence of approximately 1 in 11,000 live births, characterized by progressive degeneration and loss of α-motor neurons in the spinal cord and brain stem, resulting in progressive muscle weakness. The disease spectrum is wide, from a serious congenital to a mild adult-onset disease. SMA is caused by biallelic mutations in the SMN1 gene and disease severity is modified primarily by SMN2 copy number. Before the advent of specific disease altering treatments, SMA was the second most common fatal autosomal recessive disorder after cystic fibrosis and the most common genetic cause of infant mortality. Nusinersen, risdiplam, and onasemnogene abeparvovec are presently the only approved disease modifying therapies for SMA, and the aim of this review is to discuss their mode of action, effects, safety concerns, and results from real-world experience. All exert their action by increasing the level of SMN protein in lower motor neuron. Nusinersen and risdiplam by modifying the SMN2 gene product, and onasemnogene abeparvovec by delivering SMN1 gene copies into cells. All have an established clinical efficacy. An important feature shared by all three is that early intervention is associated with a better treatment outcome, such that in cases where treatment is initiated in an early pre-symptomatic period, it may result in normal - or almost normal - motor development. Thus, early diagnosis followed by swift initiation of treatment is fundamental for the treatment response and consequently long-term prognosis in SMA type 1, and probably SMA type 2. The same principle similarly applies to the milder phenotypes. All three therapies are relatively novel, with risdiplam being the latest addition. Except for nusinersen, real-world data are still scarce, and long-term data are quite naturally lacking.

PMID:35734367 | PMC:PMC9208376 | DOI:10.2147/DDDT.S214174

Maedica (Bucur). 2022 Mar;17(1):134-142. doi: 10.26574/maedica.2022.17.1.134.

ABSTRACT

Introduction:Pseudomonas aeruginosa is a leading cause of nosocomial infections and is especially prevalent among patients with burn wounds, cystic fibrosis, acute leukemia, organ transplants and intravenous-drug addiction. Acquired metallo-â-lactamases (MBLs) are carbapenemases which require zinc in the active site and are predominantly produced by P. aeruginosa. They belong to Ambler's class B and Bush-Jacoby Medeiros Group 3 and hydrolyse virtually all â-lactam agents, including the carbapenems. In India, only blaVIM and NDM-1 have been reported in P. aeruginosa. Metallo beta-lactamases have recently emerged as one of the most worrisome resistance mechanisms owing to their capacity to hydrolyse all beta-lactams, including carbapenems. Aims and objectives: The present study aimed to investigate the prevalence and resistance patterns of MBL-producing P. aeruginosa in a tertiary care hospital of Ghanpur, Medchal, India, and to compare the effectiveness of two different methods of screening and detecting MBL-producing P. aeruginosa in order to formulate a policy of empirical therapy and to take preventive measures in hospital settings. Methodology: In the present study, 60 isolates of Pseudomonas aeruginosa were obtained from various clinical specimens, including pus, urine, burns, wound, sputum, pleural fluid, and CSF, which were taken from inpatients and outpatients admitted to MIMS, Ghanpur, India. The study period was from January 2017 to July 2018. The microbial isolates were studied for the detection of the prevalence of MBL production, including their antibiogram. Results:Of the 60 Pseudomonas aeruginosa isolates, 12 were Imipenem resistant, of which nine were MBL producers. Most isolates (14) were collected in the age group of 21-30 years, followed by that of 31-40 years (13) and 1-10 years (2). Of the total number of samples, 40 strains were isolated in male subjects, with a male-female ratio of 2:1. Total wound swabs accounted for 40% of the studied specimens, followed by ear swabs (20%) and sputum samples (18.3%). Wound swabs also included most Imipenem-resistant isolates (41.6%). Metallo beta-lactamase producers accounted for 75% of all carbapenem-resistant isolates, using the combined disc method and E-test. By comparison, DDST retrieved 41% of Pseudomonas MBL producers. Isolates were 100% sensitive to Polymyxin-B and showed a 44.4% sensitivity to Piperacillin/Tazobactam, followed by 22.2% for Amikacin and Tobramycin and 11.1% for Ciprofloxacin and Gentamicin. Conclusion:The study found a relatively high prevalence of Pseudomonas MBL producers (9/60) with 100% Polymyxin susceptibility. Hence, our results warn against an expected high use of Polymyxins in clinical settings. Additionally, the study supports the use of E-tests, CDST and DDST for the screening of Pseudomonas MBL producers in regions where PCR detection cannot be performed.

PMID:35733755 | PMC:PMC9168566 | DOI:10.26574/maedica.2022.17.1.134

BMC Genom Data. 2022 Jun 22;23(1):48. doi: 10.1186/s12863-022-01065-7.

ABSTRACT

BACKGROUND: Colitis-associated colon cancer (CAC) patients have a younger age of onset, more multiple lesions and invasive tumors than sporadic colon cancer patients. Early detection of CAC using endoscopy is challenging, and the incidence of septal colon cancer remains high. Therefore, identifying biomarkers that can predict the tumorigenesis of CAC is in urgent need.

RESULTS: A total of 275 DEGs were identified in CAC. IGF1, BMP4, SPP1, APOB, CCND1, CD44, PTGS2, CFTR, BMP2, KLF4, and TLR2 were identified as hub DEGs, which were significantly enriched in the PI3K-Akt pathway, stem cell pluripotency regulation, focal adhesion, Hippo signaling, and AMPK signaling pathways. Sankey diagram showed that the genes of both the PI3K-AKT signaling and focal adhesion pathways were upregulated (e.g., SPP1, CD44, TLR2, CCND1, and IGF1), and upregulated genes were predicted to be regulated by the crucial miRNAs: hsa-mir-16-5p, hsa-mir-1-3p, et al. Hub gene-TFs network revealed FOXC1 as a core transcription factor. In ulcerative colitis (UC) patients, KLF4, CFTR, BMP2, TLR2 showed significantly lower expression in UC-associated cancer. BMP4 and IGF1 showed higher expression in UC-Ca compared to nonneoplastic mucosa. Survival analysis showed that the differential expression of SPP1, CFRT, and KLF4 were associated with poor prognosis in colon cancer.

CONCLUSION: Our study provides novel insights into the mechanism underlying the development of CAC. The hub genes and signaling pathways may contribute to the prevention, diagnosis and treatment of CAC.

PMID:35733095 | DOI:10.1186/s12863-022-01065-7

Sci Rep. 2022 Jun 22;12(1):10523. doi: 10.1038/s41598-022-14378-5.

ABSTRACT

This work aimed to evaluate the predatory activity of Bdellovibrio bacteriovorus 109J on clinical isolates of Pseudomonas aeruginosa selected from well-characterized collections of cystic fibrosis (CF) lung colonization (n = 30) and bloodstream infections (BSI) (n = 48) including strains selected by genetic lineage (frequent and rare sequence types), antibiotic resistance phenotype (susceptible and multidrug-resistant isolates), and colony phenotype (mucoid and non-mucoid isolates). The intraspecies predation range (I-PR) was defined as the proportion of susceptible strains within the entire collection. In contrast, the predation efficiency (PE) is the ratio of viable prey cells remaining after predation compared to the initial inoculum. I-PR was significantly higher for CF (67%) than for BSI P. aeruginosa isolates (35%) probably related to an environmental origin of CF strains whereas invasive strains are more adapted to humans. I-PR correlation with bacterial features such as mucoid morphotype, genetic background, or antibiotic susceptibility profile was not detected. To test the possibility of increasing I-PR of BSI isolates, a polyhydroxyalkanoate depolymerase deficient B. bacteriovorus bd2637 mutant was used. Global median I-PR and PE values remained constant for both predators, but 31.2% of 109J-resistant isolates were susceptible to the mutant, and 22.9% of 109J-susceptible isolates showed resistance to predation by the mutant, pointing to a predator-prey specificity process. The potential use of predators in the clinical setting should be based on the determination of the I-PR for each species, and the PE of each particular target strain.

PMID:35732651 | DOI:10.1038/s41598-022-14378-5

J Cyst Fibros. 2022 Jun 19:S1569-1993(22)00588-4. doi: 10.1016/j.jcf.2022.06.001. Online ahead of print.

ABSTRACT

BACKGROUND: Macrophages are the major resident immune cells in human airways coordinating responses to infection and injury. In cystic fibrosis (CF), neutrophils are recruited to the airways shortly after birth, and actively exocytose damaging enzymes prior to chronic infection, suggesting a potential defect in macrophage immunomodulatory function. Signaling through the exhaustion marker programmed death protein 1 (PD-1) controls macrophage function in cancer, sepsis, and airway infection. Therefore, we sought to identify potential associations between macrophage PD-1 and markers of airway disease in children with CF.

METHODS: Blood and bronchoalveolar lavage fluid (BALF) were collected from 45 children with CF aged 3 to 62 months and structural lung damage was quantified by computed tomography. The phenotype of airway leukocytes was assessed by flow cytometry, while the release of enzymes and immunomodulatory mediators by molecular assays.

RESULTS: Airway macrophage PD-1 expression correlated positively with structural lung damage, neutrophilic inflammation, and infection. Interestingly, even in the absence of detectable infection, macrophage PD-1 expression was elevated and correlated with neutrophilic inflammation. In an in vitro model mimicking leukocyte recruitment into CF airways, soluble mediators derived from recruited neutrophils directly induced PD-1 expression on recruited monocytes/macrophages, suggesting a causal link between neutrophilic inflammation and macrophage PD-1 expression in CF. Finally, blockade of PD-1 in a short-term culture of CF BALF leukocytes resulted in improved pathogen clearance.

CONCLUSION: Taken together, these findings suggest that in early CF lung disease, PD-1 upregulation associates with airway macrophage exhaustion, neutrophil takeover, infection, and structural damage.

PMID:35732550 | DOI:10.1016/j.jcf.2022.06.001

Antiviral Res. 2022 Jun 19:105368. doi: 10.1016/j.antiviral.2022.105368. Online ahead of print.

ABSTRACT

The genetic plasiticity of viruses is one of the main obstacles to the development of antivirals. The aim of this study has been to assess the ability of two physiologic oxysterols and host-targeting antivirals - namely 25- and 27-hydroxycholesterol (25OHC and 27OHC) - to select resistant strains, using human rhinovirus (HRV) as a challenging model of a viral quasispecies. Moreover, we selected 27OHC for further studies aimed at exploring its potential for the development of antiviral drugs. The results obtained with clonal or serial passage approaches show that 25OHC and 27OHC do not select HRV oxysterol-resistant variants. Moreover, we demonstrate the ability of 27OHC to inhibit the yield of HRV in 3D in vitro fully reconstituted human nasal and bronchial epithelia from cystic fibrosis patients and prevent virus-induced cilia damage. The promising antiviral activity of 27OHC and its competitive advantages over direct-acting antivirals, make this molecule a suitable candidate for further studies to explore its clinical potential.

PMID:35732227 | DOI:10.1016/j.antiviral.2022.105368

Expert Opin Emerg Drugs. 2022 Jun 22. doi: 10.1080/14728214.2022.2092612. Online ahead of print.

ABSTRACT

INTRODUCTION: Cystic fibrosis (CF) is a severe autosomal recessive disorder featuring exocrine pancreatic insufficiency and bronchiectasis. It is caused by mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR) encoding the CFTR protein which is an anion channel. CF treatment has long been based only on intensive symptomatic treatment. During the last ten years, new drugs called CFTR modulators aiming at restoring the CFTR protein function have become available, and they will benefit around 80% of patients with CF. However, more than 10% of CFTR mutations do not produce any CFTR protein for CFTR modulators to act upon.

AREAS COVERED: The development of CFTR modulators and their effectiveness in patients with CF will be reviewed. Then, the different strategies to treat patients bearing mutations non-responsive to CFTR modulators will be covered. They comprise DNA- and RNA-based therapies, readthrough agents for nonsense mutations, and cell-based therapies.

EXPERT OPINION: CF disease has changed tremendously since the advent of CFTR modulators. For mutations that are not amenable to CFTR modulators, new approaches that are being developed benefit from advances in molecular therapy, but many challenges will have to be solved before they can be safely translated to patients.

PMID:35731915 | DOI:10.1080/14728214.2022.2092612

Cochrane Database Syst Rev. 2022 Jun 22;6:CD013285. doi: 10.1002/14651858.CD013285.pub2.

ABSTRACT

BACKGROUND: There are many accepted airway clearance techniques (ACTs) for managing the respiratory health of people with cystic fibrosis (CF); none of which demonstrate superiority. Other Cochrane Reviews have reported short-term effects related to mucus transport, but no evidence supporting long-term benefits. Exercise is an alternative ACT thought to produce shearing forces within the lung parenchyma, which enhances mucociliary clearance and the removal of viscous secretions. Recent evidence suggests that some people with CF are using exercise as a substitute for traditional ACTs, yet there is no agreed recommendation for this. Additionally, one of the top 10 research questions identified by people with CF is whether exercise can replace other ACTs. Systematically reviewing the evidence for exercise as a safe and effective ACT will help people with CF decide whether to incorporate this strategy into their treatment plans and potentially reduce their treatment burden. The timing of this review is especially pertinent given the shifting landscape of CF management with the advent of highly-effective small molecule therapies, which are changing the way people with CF are cared for.

OBJECTIVES: To compare the effect of exercise to other ACTs for improving respiratory function and other clinical outcomes in people with CF and to assess the potential adverse effects associated with this ACT.

SEARCH METHODS: On 28 February 2022, we searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews. We searched online clinical trial registries on 15 February 2022. We emailed authors of studies awaiting classification or potentially eligible abstracts for additional information on 1 February 2021.

SELECTION CRITERIA: We selected randomised controlled studies (RCTs) and quasi-RCTs comparing exercise to another ACT in people with CF for at least two treatment sessions.

DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data and assessed risk of bias for the included studies. They assessed the certainty of the evidence using GRADE. Review authors contacted investigators for further relevant information regarding their publications.

MAIN RESULTS: We included four RCTs. The 86 participants had a wide range of disease severity (forced expiratory volume in one second (FEV1) ranged from 54% to 95%) and were 7 to 41 years old. Two RCTs were cross-over and two were parallel in design. Participants in one RCT were hospitalised with an acute respiratory exacerbation, whilst the participants in three RCTs were clinically stable. All four RCTs compared exercise either alone or in combination with another ACT, but these were too diverse to allow us to combine results. The certainty of the evidence was very low; we downgraded it due to low participant numbers and high or unclear risks of bias across all domains. Exercise versus active cycle of breathing technique (ACBT) One cross-over trial (18 participants) compared exercise alone to ACBT. There was no change from baseline in our primary outcome FEV1, although it increased in the exercise group before returning to baseline after 30 minutes; we are unsure if exercise affected FEV1 as the evidence is very low-certainty. Similar results were seen for other measures of lung function. No adverse events occurred during the exercise sessions (very low-certainty evidence). We are unsure if ACBT was perceived to be more effective or was the preferred ACT (very low-certainty evidence). 24-hour sputum volume was less in the exercise group than with ACBT (secondary outcome). Exercise capacity, quality of life, adherence, hospitalisations and need for additional antibiotics were not reported. Exercise plus postural drainage and percussion (PD&P) versus PD&P only Two trials (55 participants) compared exercise and PD&P to PD&P alone. At two weeks, one trial narratively reported a greater increase in FEV1 % predicted with PD&P alone. At six months, the other trial reported a greater increase with exercise combined with PD&P, but did not provide data for the PD&P group. We are uncertain whether exercise with PD&P improves FEV1 as the certainty of evidence is very low. Other measures of lung function did not show clear evidence of effect. One trial reported no difference in exercise capacity (maximal work rate) after two weeks. No adverse events were reported (1 trial, 17 participants; very low-certainty evidence). Adherence was high, with all PD&P sessions and 96% of exercise sessions completed (1 trial, 17 participants; very low-certainty evidence). There was no difference between groups in 24-hour sputum volume or in the mean duration of hospitalisation, although the six-month trial reported fewer hospitalisations due to exacerbations in the exercise and PD&P group. Quality of life, ACT preference and need for antibiotics were not reported. Exercise versus underwater positive expiratory pressure (uPEP) One trial (13 participants) compared exercise to uPEP (also known as bubble PEP). No adverse events were recorded in either group (very low-certainty evidence). Trial investigators reported that participants perceived exercise as more fatiguing but also more enjoyable than bubble PEP (very low-certainty evidence). There were no differences found in the total weight of sputum collected during treatment sessions. The trial did not report the primary outcomes (FEV1, quality of life, exercise capacity) or the secondary outcomes (other measures of lung function, adherence, need for antibiotics or hospitalisations).

AUTHORS' CONCLUSIONS: As one of the top 10 research questions identified by clinicians and people with CF, it is important to systematically review the literature regarding whether or not exercise is an acceptable and effective ACT, and whether it can replace traditional methods. We identified an insufficient number of trials to conclude whether or not exercise is a suitable alternative ACT, and the diverse design of included trials did not allow for meta-analysis of results. The evidence is very low-certainty, so we are uncertain about the effectiveness of exercise as an ACT. Longer studies examining outcomes that are important to people with CF are required to answer this question.

PMID:35731672 | DOI:10.1002/14651858.CD013285.pub2

JCI Insight. 2022 Jun 22;7(12):e152629. doi: 10.1172/jci.insight.152629.

ABSTRACT

Thick, viscous respiratory secretions are a major pathogenic feature of COVID-19, but the composition and physical properties of these secretions are poorly understood. We characterized the composition and rheological properties (i.e., resistance to flow) of respiratory secretions collected from intubated COVID-19 patients. We found the percentages of solids and protein content were greatly elevated in COVID-19 compared with heathy control samples and closely resembled levels seen in cystic fibrosis, a genetic disease known for thick, tenacious respiratory secretions. DNA and hyaluronan (HA) were major components of respiratory secretions in COVID-19 and were likewise abundant in cadaveric lung tissues from these patients. COVID-19 secretions exhibited heterogeneous rheological behaviors, with thicker samples showing increased sensitivity to DNase and hyaluronidase treatment. In histologic sections from these same patients, we observed increased accumulation of HA and the hyaladherin versican but reduced tumor necrosis factor-stimulated gene-6 staining, consistent with the inflammatory nature of these secretions. Finally, we observed diminished type I interferon and enhanced inflammatory cytokines in these secretions. Overall, our studies indicated that increases in HA and DNA in COVID-19 respiratory secretion samples correlated with enhanced inflammatory burden and suggested that DNA and HA may be viable therapeutic targets in COVID-19 infection.

PMID:35730564 | DOI:10.1172/jci.insight.152629

Front Biosci (Schol Ed). 2022 Mar 21;14(2):9. doi: 10.31083/j.fbs1402009.

ABSTRACT

The role of Achromobacter species in lung disease remains unclear. The aim of this study was to characterize Achromobacter isolated from persons with cystic fibrosis and from other clinical samples. Whole genome sequences from 101 Achromobacter isolates were determined (81 from patients with cystic fibrosis and 20 from other patients) and analysed. Taxonomic analysis showed nine species including two putative novel species. Thirty-five novel sequence types were present. The most active agent was co-trimoxazole followed by imipenem, but Minimal Inhibitory Concentrations (MICs) were high. Acquired antibiotic resistance genes were rare. Their presence did not correlate with minimal inhibitory concentrations suggesting that other mechanisms are involved. Genes for proposed virulence factors were present in only some isolates. Two putative novel species were identified. The putative virulence properties of Achromobacter involved in infections are variable. Despite the high MICs, acquired resistance genes are uncommon.

PMID:35730434 | DOI:10.31083/j.fbs1402009

BMC Pulm Med. 2022 Jun 21;22(1):241. doi: 10.1186/s12890-022-02039-2.

ABSTRACT

BACKGROUND: Airway clearance techniques are supposed to be a necessary adjunct for the enhancement of impaired peripheral clearance in cystic fibrosis (CF). The objective was to assess the effect of one physiotherapy session (autogenic drainage: AD) on mucus clearance (sputum wet weight) and impulse oscillometry system (IOS) indices, including those obtained from extended Resistance-Inertance-Compliance (eRIC) modelling, considering the degree of bronchial congestion.

METHODS: Thirty children with CF (median age: 12.7 years) in a stable condition prospectively underwent IOS measurements at baseline and after AD. They were divided in two groups: with (visual analog scale of bronchial congestion by the physiotherapist ≥ 5/10) and without (scale < 5/10) bronchial congestion. Paired-comparison of the effects of AD on airway resistance measurements was done with Wilcoxon test.

RESULTS: The congestion scale correlated with the wet weight of sputum production during the session (Pearson test: p < 0.0001, R = 0.66). Ten children had bronchial congestion and 20 were without congestion. In the whole group, R5-20 Hz significantly decreased after AD (P = 0.049), which was related to a decrease in the children with congestion (P = 0.025), whereas it was not significantly modified in the children without congestion (P = 0.327). The eRIC model allowed the calculation of the peripheral resistance of the respiratory system, which also decreased in the children with congestion (P = 0.037), however, not modified in the children without congestion (P = 0.390).

CONCLUSION: One session of autogenic drainage has the ability to decrease peripheral resistance obtained from IOS measurements, more specifically in children with CF with moderate to severe bronchial congestion.

TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04094441.

PMID:35729620 | DOI:10.1186/s12890-022-02039-2

Trends Cell Biol. 2022 Jun 18:S0962-8924(22)00135-0. doi: 10.1016/j.tcb.2022.05.004. Online ahead of print.

ABSTRACT

The J-domain proteins (JDP) form the largest protein family among cellular chaperones. In cooperation with the Hsp70 chaperone system, these co-chaperones orchestrate a plethora of distinct functions, including those that help maintain cellular proteostasis and development. JDPs evolved largely through the fusion of a J-domain with other protein subdomains. The highly conserved J-domain facilitates the binding and activation of Hsp70s. How JDPs (re)wire Hsp70 chaperone circuits and promote functional diversity remains insufficiently explained. Here, we discuss recent advances in our understanding of the JDP family with a focus on the regulation built around J-domains to ensure correct pairing and assembly of JDP-Hsp70 machineries that operate on different clientele under various cellular growth conditions.

PMID:35729039 | DOI:10.1016/j.tcb.2022.05.004

PLoS Biol. 2022 Jun 21;20(6):e3001679. doi: 10.1371/journal.pbio.3001679. Online ahead of print.

ABSTRACT

Bacteria typically exist in dynamic, multispecies communities where polymicrobial interactions influence fitness. Elucidating the molecular mechanisms underlying these interactions is critical for understanding and modulating bacterial behavior in natural environments. While bacterial responses to foreign species are frequently characterized at the molecular and phenotypic level, the exogenous molecules that elicit these responses are understudied. Here, we outline a systematic strategy based on transcriptomics combined with genetic and biochemical screens of promoter-reporters to identify the molecules from one species that are sensed by another. We utilized this method to study interactions between the pathogens Pseudomonas aeruginosa and Staphylococcus aureus that are frequently found in coinfections. We discovered that P. aeruginosa senses diverse staphylococcal exoproducts including the metallophore staphylopine (StP), intermediate metabolites citrate and acetoin, and multiple molecules that modulate its iron starvation response. We observed that StP inhibits biofilm formation and that P. aeruginosa can utilize citrate and acetoin for growth, revealing that these interactions have both antagonistic and beneficial effects. Due to the unbiased nature of our approach, we also identified on a genome scale the genes in S. aureus that affect production of each sensed exoproduct, providing possible targets to modify multispecies community dynamics. Further, a combination of these identified S. aureus products recapitulated a majority of the transcriptional response of P. aeruginosa to S. aureus supernatant, validating our screening strategy. Cystic fibrosis (CF) clinical isolates of both S. aureus and P. aeruginosa also showed varying degrees of induction or responses, respectively, which suggests that these interactions are widespread among pathogenic strains. Our screening approach thus identified multiple S. aureus secreted molecules that are sensed by P. aeruginosa and affect its physiology, demonstrating the efficacy of this approach, and yielding new insight into the molecular basis of interactions between these 2 species.

PMID:35727825 | DOI:10.1371/journal.pbio.3001679

Microbiol Spectr. 2022 Jun 21:e0081322. doi: 10.1128/spectrum.00813-22. Online ahead of print.

ABSTRACT

Pseudomonas aeruginosa is the most common pathogen infecting the lungs of people with cystic fibrosis (CF), causing both acute and chronic infections. Intrinsic and acquired antibiotic resistance, coupled with the physical barriers resulting from desiccated CF sputum, allow P. aeruginosa to colonize and persist in spite of antibiotic treatment. As well as the specific difficulties in eradicating P. aeruginosa from CF lungs, P. aeruginosa is also subject to the wider, global issue of antimicrobial resistance. Glatiramer acetate (GA) is a peptide drug, used in the treatment of multiple sclerosis (MS), which has been shown to have moderate antipseudomonal activity. Other antimicrobial peptides (AMPs) have been shown to be antibiotic resistance breakers, potentiating the activities of antibiotics when given in combination, restoring and/or enhancing antibiotic efficacy. Growth, viability, MIC determinations, and synergy analysis showed that GA improved the efficacy of tobramycin (TOB) against reference strains of P. aeruginosa, reducing TOB MICs and synergizing with the aminoglycoside. This was also the case for clinical strains from people with CF. GA significantly reduced the MIC50 of TOB for viable cells from 1.69 mg/L (95% confidence interval [CI], 0.26 to 8.97) to 0.62 mg/L (95% CI, 0.15 to 3.94; P = 0.002) and the MIC90 for viable cells from 7.00 mg/L (95% CI, 1.18 to 26.50) to 2.20 mg/L (95% CI, 0.99 to 15.03; P = 0.001), compared to results with TOB only. Investigation of mechanisms of GA activity showed that GA resulted in significant disruption of outer membranes, depolarization of cytoplasmic membranes, and permeabilization of P. aeruginosa and was the only agent tested (including cationic AMPs) to significantly affect all three mechanisms. IMPORTANCE The antimicrobial resistance crisis urgently requires solutions to the lost efficacy of antibiotics. The repurposing of drugs already in clinical use, with strong safety profiles, as antibiotic adjuvants to restore the efficacy of antibiotics is an important avenue to alleviating the resistance crisis. This research shows that a clinically used drug from outside infection treatment, glatiramer acetate, reduces the concentration of tobramycin required to be effective in treating Pseudomonas aeruginosa, based on analyses of both reference and clinical respiratory isolates from people with cystic fibrosis. The two agents acted synergistically against P. aeruginosa, being more effective combined in vitro than predicted for their combination. As a peptide drug, glatiramer acetate functions similarly to many antimicrobial peptides, interacting with and disrupting the P. aeruginosa cell wall and permeabilizing bacterial cells, thereby allowing tobramycin to work. Our findings demonstrate that glatiramer acetate is a strong candidate for repurposing as an antibiotic resistance breaker of pathogenic P. aeruginosa.

PMID:35727066 | DOI:10.1128/spectrum.00813-22

Nat Commun. 2022 Jun 20;13(1):3542. doi: 10.1038/s41467-022-31062-4.

ABSTRACT

Mucin domains are densely O-glycosylated modular protein domains found in various extracellular and transmembrane proteins. Mucin-domain glycoproteins play important roles in many human diseases, such as cancer and cystic fibrosis, but the scope of the mucinome remains poorly defined. Recently, we characterized a bacterial O-glycoprotease, StcE, and demonstrated that an inactive point mutant retains binding selectivity for mucin-domain glycoproteins. In this work, we leverage inactive StcE to selectively enrich and identify mucin-domain glycoproteins from complex samples like cell lysate and crude ovarian cancer patient ascites fluid. Our enrichment strategy is further aided by an algorithm to assign confidence to mucin-domain glycoprotein identifications. This mucinomics platform facilitates detection of hundreds of glycopeptides from mucin domains and highly overlapping populations of mucin-domain glycoproteins from ovarian cancer patients. Ultimately, we demonstrate our mucinomics approach can reveal key molecular signatures of cancer from in vitro and ex vivo sources.

PMID:35725833 | DOI:10.1038/s41467-022-31062-4

Basic Clin Androl. 2022 Jun 21;32(1):10. doi: 10.1186/s12610-022-00160-0.

ABSTRACT

Cryptorchidism occurs frequently in children with cystic fibrosis. Among boys with cryptorchidism and abrogated mini-puberty, the development of the epididymis and the vas deferens is frequently impaired. This finding suggests that a common cause underlies the abnormal development of Ad spermatogonia and the epididymis. The cystic fibrosis transmembrane conductance regulator (CFTR) is an ATP-binding cassette transporter protein that acts as a chloride channel. The CFTR gene has been associated with spermatogenesis and male fertility. In boys with cryptorchidism, prepubertal hypogonadotropic hypogonadism induces suboptimal expression of the ankyrin-like protein gene, ASZ1, the P-element induced wimpy testis-like gene, PIWIL, and CFTR. The abrogated expression of these gene leads to transposon reactivation, and ultimately, infertility. Curative gonadotropin-releasing hormone agonist (GnRHa) treatment stimulates the expression of CFTR and PIWIL3, which play important roles in the development of Ad spermatogonia and fertility. Furthermore, GnRHa stimulates the expression of the epididymal androgen-sensitive genes, CRISP1, WFDC8, SPINK13, and PAX2, which thereby promotes epididymal development. This review focuses on molecular evidence that favors a role for CFTR in cryptorchidism-induced infertility. Based on information available in the literature, we interpreted our RNA-Seq expression data obtained from samples before and after randomized GnRHa treatment in boys with bilateral cryptorchidism. We propose that, in boys with cryptorchidism, CFTR expression is controlled by luteinizing hormone and testosterone. Moreover, CFTR regulates the activities of genes that are important for fertility and Wolffian duct differentiation.

PMID:35725394 | DOI:10.1186/s12610-022-00160-0

Rech Soins Infirm. 2022;147(4):42-54. doi: 10.3917/rsi.147.0042.

ABSTRACT

Patient autonomy is an equivocal notion that refers to several intertwined figures. What is expected of young cystic fibrosis patients when speaking to actors (professionals and associations) involved with them ? In this sociological contribution, we show the limits of a medical model of autonomy that does not allow us to think about a whole series of micro-adjustments to the practices of people with cystic fibrosis. The analysis is based on publications by national associations fighting against cystic fibrosis, and on semi-structured interviews with professionals working with people living with this disease. It shows that autonomy is not only thought of by the professionals who support them in terms of an individual management model centered on the patient's medical skills and personal resources, but also as the result of environmental factors. It reveals an innovative characteristic of autonomy in the field of health care, largely supported by the specialized and reinforced medical support of coordinating nurses. This support allows the development of a detailed clinical knowledge of the situations experienced by their patients.

PMID:35724038 | DOI:10.3917/rsi.147.0042

Pediatr Nephrol. 2022 Jun 20. doi: 10.1007/s00467-022-05647-6. Online ahead of print.

NO ABSTRACT

PMID:35723735 | DOI:10.1007/s00467-022-05647-6

Curr Issues Mol Biol. 2022 Feb 8;44(2):833-844. doi: 10.3390/cimb44020057.

ABSTRACT

Drug hypersensitivity reactions are an unavoidable clinical consequence of the presence of new therapeutic agents. These adverse reactions concern patients afflicted with infectious diseases (e.g., hypersensitivity to antibiotics), and with non-infectious chronic diseases, such as in cancers, diabetes or cystic fibrosis treatments, and may occur at the first drug administration or after repeated exposures. Here we revise recent key studies on the mechanisms underlying the desensitization protocols, and propose an additional temporal regulation layer that is based on the circadian control of the signaling pathway involved and on the modulation of the memory effects established by the desensitization procedures.

PMID:35723342 | DOI:10.3390/cimb44020057