J Fungi (Basel). 2021 Oct 12;7(10):855. doi: 10.3390/jof7100855.

ABSTRACT

Malassezia are a lipid-dependent basidiomycetous yeast of the normal skin microbiome, although Malassezia DNA has been recently detected in other body sites and has been associated with certain chronic human diseases. This new perspective raises many questions. Are these yeasts truly present in the investigated body site or were they contaminated by other body sites, adjacent or not? Does this DNA contamination come from living or dead yeast? If these yeasts are alive, do they belong to the resident mycobiota or are they transient colonizers which are not permanently established within these niches? Finally, are these yeasts associated with certain chronic diseases or not? In an attempt to shed light on this knowledge gap, we critically reviewed the 31 published studies focusing on the association of Malassezia spp. with chronic human diseases, including psoriasis, atopic dermatitis (AD), chronic rhinosinusitis (CRS), asthma, cystic fibrosis (CF), HIV infection, inflammatory bowel disease (IBD), colorectal cancer (CRC), and neurodegenerative diseases.

PMID:34682276 | PMC:PMC8540640 | DOI:10.3390/jof7100855

Children (Basel). 2021 Sep 27;8(10):857. doi: 10.3390/children8100857.

ABSTRACT

Spirometry is considered the gold standard method for monitoring lung function of patients with cystic fibrosis (CF) but it requires patients' cooperation and therefore it is not useful for the majority of preschool-aged children. Oscillometry is an alternative modality for lung function monitoring that requires minimal cooperation and can be applied in children as young as 3 years of age. Furthermore, it generates lesser aerosol compared to spirometry, an issue that is of considerable importance in the COVID-19 era. The aim of this review was to present the existing clinical data regarding the application of oscillometry in children and adolescents with CF. The method seems to have acceptable feasibility and repeatability. However, there is conflicting data regarding the correlation of oscillometry values with the clinical symptoms of CF patients either in clinically stable or in exacerbation periods. Furthermore, it is not clear to what extent oscillometry measurements correlate with the spirometry indices. Based on current evidence, spirometry cannot be substituted by oscillometry in the monitoring of the respiratory status of children and adolescents with CF.

PMID:34682122 | PMC:PMC8534643 | DOI:10.3390/children8100857

Pharmaceuticals (Basel). 2021 Oct 3;14(10):1019. doi: 10.3390/ph14101019.

ABSTRACT

Phage therapy is the use of bacterial viruses as antibacterial agents. A primary consideration for commercial development of phages for phage therapy is the number of different bacterial strains that are successfully targeted, as this defines the breadth of a phage cocktail's spectrum of activity. Alternatively, phage cocktails may be used to reduce the potential for bacteria to evolve phage resistance. This, as we consider here, is in part a function of a cocktail's 'depth' of activity. Improved cocktail depth is achieved through inclusion of at least two phages able to infect a single bacterial strain, especially two phages against which bacterial mutation to cross resistance is relatively rare. Here, we consider the breadth of activity of phage cocktails while taking both depth of activity and bacterial mutation to cross resistance into account. This is done by building on familiar algorithms normally used for determination solely of phage cocktail breadth of activity. We show in particular how phage cocktails for phage therapy may be rationally designed toward enhancing the number of bacteria impacted while also reducing the potential for a subset of those bacteria to evolve phage resistance, all as based on previously determined phage properties.

PMID:34681243 | PMC:PMC8541335 | DOI:10.3390/ph14101019

Genes (Basel). 2021 Sep 29;12(10):1554. doi: 10.3390/genes12101554.

ABSTRACT

CFTR encodes for a chloride and bicarbonate channel expressed at the apical membrane of polarized epithelial cells. Transepithelial sodium transport mediated by the amiloride-sensitive sodium channel ENaC is thought to contribute to the manifestation of CF disease. Thus, ENaC is a therapeutic target in CF and a valid cystic fibrosis modifier gene. We have characterized SCNN1B as a genetic modifier in the three independent patient cohorts of F508del-CFTR homozygotes. We could identify a regulatory element at SCNN1B to the genomic segment rs168748-rs2303153-rs4968000 by fine-mapping (Pbest = 0.0177), consistently observing the risk allele rs2303153-C and the contrasting benign allele rs2303153-G in all three patient cohorts. Furthermore, our results show that expression levels of SCNN1B are associated with rs2303153 genotype in intestinal epithelia (p = 0.003). Our data confirm that the well-established biological role of SCNN1B can be recognized by an association study on informative endophenotypes in the rare disease cystic fibrosis and calls attention to reproducible results in association studies obtained from small, albeit carefully characterized patient populations.

PMID:34680949 | PMC:PMC8535344 | DOI:10.3390/genes12101554

Antibiotics (Basel). 2021 Sep 27;10(10):1176. doi: 10.3390/antibiotics10101176.

ABSTRACT

Cystic fibrosis (CF) is a genetic disorder causing dysfunctional ion transport resulting in accumulation of viscous mucus that fosters chronic bacterial biofilm-associated infection in the airways. Achromobacter xylosoxidans and Stenotrophomonas maltophilia are increasingly prevalent CF pathogens and while Burkholderia cencocepacia is slowly decreasing; all are complicated by multidrug resistance that is enhanced by biofilm formation. This study investigates potential synergy between the antibiotics ciprofloxacin (0.5-128 µg/mL), colistin (0.5-128 µg/mL) and tobramycin (0.5-128 µg/mL) when combined with the neutral pH form of N-Acetylcysteine (NACneutral) (0.5-16.3 mg/mL) against 11 cystic fibrosis strains of Burkholderia, Stenotrophomonas and Achromobacter sp. in planktonic and biofilm cultures. We screened for potential synergism using checkerboard assays from which fraction inhibitory concentration indices (FICI) were calculated. Synergistic (FICI ≤ 0.5) and additive (0.5 > FICI ≥ 1) combinations were tested on irreversibly attached bacteria and 48 h mature biofilms via time-course and colony forming units (CFU/mL) assays. This study suggests that planktonic FICI analysis does not necessarily translate to reduction in bacterial loads in a biofilm model. Future directions include refining synergy testing and determining further mechanisms of action of NAC to understand how it may interact with antibiotics to better predict synergy.

PMID:34680757 | PMC:PMC8532722 | DOI:10.3390/antibiotics10101176

Antibiotics (Basel). 2021 Sep 25;10(10):1164. doi: 10.3390/antibiotics10101164.

ABSTRACT

Antibiotic-resistant Pseudomonas aeruginosa infections are the primary cause of mortality in people with cystic fibrosis (CF). Yet, it has only recently become appreciated that resistance mutations can also increase P. aeruginosa virulence, even in the absence of antibiotics. Moreover, the mechanisms by which resistance mutations increase virulence are poorly understood. In this study we tested the hypothesis that mutations affecting efflux pumps can directly increase P. aeruginosa virulence. Using genetics, physiological assays, and model infections, we show that efflux pump mutations can increase virulence. Mutations of the mexEF efflux pump system increased swarming, rhamnolipid production, and lethality in a mouse infection model, while mutations in mexR that increased expression of the mexAB-oprM efflux system increased virulence during an acute murine lung infection without affecting swarming or rhamnolipid gene expression. Finally, we show that an efflux pump inhibitor, which represents a proposed novel treatment approach for P. aeruginosa, increased rhamnolipid gene expression in a dose-dependent manner. This finding is important because rhamnolipids are key virulence factors involved in dissemination through epithelial barriers and cause neutrophil necrosis. Together, these data show how current and proposed future anti-Pseudomonal treatments may unintentionally make infections worse by increasing virulence. Therefore, treatments that target efflux should be pursued with caution.

PMID:34680745 | PMC:PMC8532662 | DOI:10.3390/antibiotics10101164

Biomedicines. 2021 Oct 10;9(10):1437. doi: 10.3390/biomedicines9101437.

ABSTRACT

In recent years, numerous pathways were explored in the pathogenesis of COPD in the quest for new potential therapeutic targets for more personalised medical care. In this context, the study of the cystic fibrosis transmembrane conductance regulator (CFTR) began to gain importance, especially since the advent of the new CFTR modulators which had the potential to correct this protein's dysfunction in COPD. The CFTR is an ion transporter that regulates the hydration and viscosity of mucous secretions in the airway. Therefore, its abnormal function favours the accumulation of thicker and more viscous secretions, reduces the periciliary layer and mucociliary clearance, and produces inflammation in the airway, as a consequence of a bronchial infection by both bacteria and viruses. Identifying CFTR dysfunction in the context of COPD pathogenesis is key to fully understanding its role in the complex pathophysiology of COPD and the potential of the different therapeutic approaches proposed to overcome this dysfunction. In particular, the potential of the rehydration of mucus and the role of antioxidants and phosphodiesterase inhibitors should be discussed. Additionally, the modulatory drugs which enhance or restore decreased levels of the protein CFTR were recently described. In particular, two CFTR potentiators, ivacaftor and icenticaftor, were explored in COPD. The present review updated the pathophysiology of the complex role of CFTR in COPD and the therapeutic options which could be explored.

PMID:34680554 | PMC:PMC8533244 | DOI:10.3390/biomedicines9101437

Biomolecules. 2021 Sep 28;11(10):1417. doi: 10.3390/biom11101417.

ABSTRACT

Cystic fibrosis (CF) is caused by loss-of-function mutations in the CF transmembrane conductance regulator (CFTR) protein, an anion channel that regulates epithelial surface fluid secretion. The deletion of phenylalanine at position 508 (F508del) is the most common CFTR mutation. F508del CFTR is characterized by folding and trafficking defects, resulting in decreased functional expression of the protein on the plasma membrane. Several classes of small molecules, named correctors, have been developed to rescue defective F508del CFTR. Although individual correctors failed to improve the clinical status of CF patients carrying the F508del mutation, better results were obtained using correctors combinations. These results were obtained according to the premise that the administration of correctors having different sites of action should enhance F508del CFTR rescue. We investigated the putative site of action of an aminoarylthiazole 4-(3-chlorophenyl)-N-(3-(methylthio)phenyl)thiazol-2-amine, named FCG, with proven CFTR corrector activity, and its synergistic effect with the corrector VX809. We found that neither the total expression nor the maturation of WT CFTR transiently expressed in human embryonic kidney 293 cells was influenced by FCG, administrated alone or in combination with VX809. On the contrary, FCG was able to enhance F508del CFTR total expression, and its combination with VX809 provided a further effect, being able to increase not only the total expression but also the maturation of the mutant protein. Analyses on different CFTR domains and groups of domains, heterologously expressed in HEK293 cells, show that NBD2 is necessary for FCG corrector activity. Molecular modelling analyses suggest that FCG interacts with a putative region located into the NBD2, ascribing this molecule to class II correctors. Our study indicates that the continuous development and testing of combinations of correctors targeting different structural and functional defects of mutant CFTR is the best strategy to ensure a valuable therapeutic perspective to a larger cohort of CF patients.

PMID:34680050 | PMC:PMC8533355 | DOI:10.3390/biom11101417

J Am Med Inform Assoc. 2021 Oct 22:ocab224. doi: 10.1093/jamia/ocab224. Online ahead of print.

ABSTRACT

Data on the safety and effectiveness of contraception among women with rare diseases are critical and sorely lacking. To fill this gap, we propose a national, patient-driven database that tracks contraceptive safety and effectiveness among women with rare diseases. We built a pilot database focusing on women with cystic fibrosis in 3 phases: (1) database design input from patients and experts, (2) merging of contraceptive survey data with relevant clinical outcomes from the Cystic Fibrosis Foundation Patient Registry (CFFPR), and (3) forming a data guide to facilitate accessible output data. We successfully linked 62 contraceptive survey variables with 362 relevant clinical outcome variables for 150 patients. This pilot represents a breakthrough in linking contraceptive data to disease-specific outcomes and informs how to build a national, patient-driven contraceptive database for women with rare diseases.

PMID:34679174 | DOI:10.1093/jamia/ocab224

J Hepatol. 2021 Oct 19:S0168-8278(21)02115-2. doi: 10.1016/j.jhep.2021.09.042. Online ahead of print.

ABSTRACT

Cystic fibrosis (CF) is the most common autosomal recessive disease in the Caucasian population. Cystic Fibrosis-related Liver Disease (CFLD) is defined by the pathogenesis related to the underlying CFTR defect in biliary epithelial cells. CFLD needs to be distinguished from other liver manifestations that may not have any pathological significance. The clinical and histological presentation as well as the severity of CFLD varies. The main histological presentation of CFLD is focal biliary fibrosis, which is usually asymptomatic. Portal hypertension develops in a minority of cases (about 10%) and may require specific management including liver transplantation for end-stage liver disease. Portal hypertension is usually the result of the progression of focal biliary fibrosis to multilobular cirrhosis during childhood. Nevertheless, non-cirrhotic portal hypertension as a result of porto-sinusoidal vascular disease is now identified increasingly more frequently in these patients, mainly in young adults. To evaluate the effect of new CFTR modulator therapies on the liver, the spectrum of hepatobiliary involvement must first be precisely classified. This paper discusses the phenotypical features of CFLD, its underlying physiopathology and relevant diagnostic and follow-up approaches with a special focus on imaging.

PMID:34678405 | DOI:10.1016/j.jhep.2021.09.042

Stem Cell Reports. 2021 Oct 12:S2213-6711(21)00497-5. doi: 10.1016/j.stemcr.2021.09.020. Online ahead of print.

ABSTRACT

For those people with cystic fibrosis carrying rare CFTR mutations not responding to currently available therapies, there is an unmet need for relevant tissue models for therapy development. Here, we describe a new testing platform that employs patient-specific induced pluripotent stem cells (iPSCs) differentiated to lung progenitor cells that can be studied using a dynamic, high-throughput fluorescence-based assay of CFTR channel activity. Our proof-of-concept studies support the potential use of this platform, together with a Canadian bioresource that contains iPSC lines and matched nasal cultures from people with rare mutations, to advance patient-oriented therapy development. Interventions identified in the high-throughput, stem cell-based model and validated in primary nasal cultures from the same person have the potential to be advanced as therapies.

PMID:34678210 | DOI:10.1016/j.stemcr.2021.09.020

Front Microbiol. 2021 Oct 4;12:666097. doi: 10.3389/fmicb.2021.666097. eCollection 2021.

ABSTRACT

ExoY is among the effectors that are injected by the type III secretion system (T3SS) of Pseudomonas aeruginosa into host cells. Inside eukaryotic cells, ExoY interacts with F-actin, which stimulates its potent nucleotidyl cyclase activity to produce cyclic nucleotide monophosphates (cNMPs). ExoY has broad substrate specificity with GTP as a preferential substrate in vitro. How ExoY contributes to the virulence of P. aeruginosa remains largely unknown. Here, we examined the prevalence of active ExoY among strains from the international P. aeruginosa reference panel, a collection of strains that includes environmental and clinical isolates, commonly used laboratory strains, and sequential clonal isolates from cystic fibrosis (CF) patients and thus represents the large diversity of this bacterial species. The ability to secrete active ExoY was determined by measuring the F-actin stimulated guanylate cyclase (GC) activity in bacterial culture supernatants. We found an overall ExoY activity prevalence of about 60% among the 40 examined strains with no significant difference between CF and non-CF isolates. In parallel, we used cellular infection models of human lung epithelial cells to compare the cytotoxic effects of isogenic reference strains expressing active ExoY or lacking the exoY gene. We found that P. aeruginosa strains lacking ExoY were in fact more cytotoxic to the epithelial cells than those secreting active ExoY. This suggests that under certain conditions, ExoY might partly alleviate the cytotoxic effects of other virulence factors of P. aeruginosa.

PMID:34675890 | PMC:PMC8524455 | DOI:10.3389/fmicb.2021.666097

Clin Med Insights Endocrinol Diabetes. 2021 Oct 12;14:11795514211048813. doi: 10.1177/11795514211048813. eCollection 2021.

ABSTRACT

Cystic fibrosis (CF) is an autosomal recessive chronic condition effecting approximately 70 000 to 100 000 people globally and is caused by a loss-of-function mutation in the CF transmembrane conductance regulator. Through improvements in clinical care, life expectancy in CF has increased considerably associated with rising incidence of secondary complications including CF-related diabetes (CFRD). CFRD is believed to result from β-cell loss as well as insufficient insulin secretion due to β-cell dysfunction, but the underlying pathophysiology is not yet fully understood. Here we review the morphological and cellular changes in addition to the architectural remodelling of the pancreatic exocrine and endocrine compartments in CF and CFRD pancreas. We consider also potential underlying proinflammatory signalling pathways impacting on endocrine and specifically β-cell function, concluding that further research focused on these mechanisms may uncover novel therapeutic targets enabling restoration of normal insulin secretion.

PMID:34675737 | PMC:PMC8524685 | DOI:10.1177/11795514211048813

J Microbiol Immunol Infect. 2021 Oct 8:S1684-1182(21)00198-5. doi: 10.1016/j.jmii.2021.09.009. Online ahead of print.

ABSTRACT

BACKGROUND: Burkholderia cepacia complex (BCC) represents a group of multidrug-resistant gram-negative bacteria that cause infections among immunocompromised hosts. Bacteremia occurs in patients who are chronically ill and is associated with substantial morbidity and mortality. The aim of this study was to investigate the clinical characteristics and outcomes of BCC bacteremic patients without cystic fibrosis.

METHODS: We conducted a retrospective study at the National Taiwan University Hospital. Adults with BCC bacteremia from January 2015 to May 2019 were enrolled. The primary outcome was 14-day mortality. Multivariable logistic regression was performed for outcome analysis.

RESULTS: One-hundred and ninety-five patients were analyzed and their mean age was 67 years. Over 95% of the BCC isolates were susceptible to trimethoprim/sulfomethoxazole (TMP/SXT). Levofloxacin resistance rates were high, with only 25.1% of isolates being susceptible. Pairwise comparisons were made between different definitive regimens including meropenem-monotherapy, ceftazidime-monotherapy, levofloxacin-monotherapy, TMP/SXT-monotherapy, tigecycline-monotherapy as well as combination versus monotherapy. No regimen was significantly associated with survival in our study. Multivariable logistic regression showed that the Pitt bacteremia score (adjust odds ratio [aOR],1.46; 95% confidence interval [CI],1.19-1.79; p < 0.001), underlying metastatic cancer (aOR, 2.73; 95% CI, 1.01-7.39; p = 0.047), inappropriate definitive treatment independently predicted greater 14-day mortality (aOR, 8.21; 95% CI, 2.49-27.08; p < 0.001).

CONCLUSIONS: No single regimen is associated with improved mortality. After adjusting for other potential confounders, our data suggest selection of an appropriate antibiotic provide better clinical outcomes among patients with BCC bacteremia.

PMID:34674957 | DOI:10.1016/j.jmii.2021.09.009

Ann Otol Rhinol Laryngol. 2021 Oct 21:34894211051814. doi: 10.1177/00034894211051814. Online ahead of print.

ABSTRACT

OBJECTIVES: In cystic fibrosis (CF), loss of CFTR-mediated bicarbonate secretion reduces the airway surface liquid (ASL) pH causing airway host defense defects. Aerosolized sodium bicarbonate can reverse these defects, but its effects are short-lived. Aerosolized tromethamine (THAM) also raises the ASL pH but its effects are much longer lasting. In this pilot study, we tested the hypothesis that nasally administered THAM would alter the nasal bacterial composition in adults with and without CF.

METHODS: Subjects (n = 32 total) received intranasally administered normal saline or THAM followed by a wash out period prior to receiving the other treatment. Nasal bacterial cultures were obtained prior to and after each treatment period.

RESULTS: At baseline, nasal swab bacterial counts were similar between non-CF and CF subjects, but CF subjects had reduced microbial diversity. Both nasal saline and THAM were well-tolerated. In non-CF subjects, nasal airway alkalinization decreased both the total bacterial density and the gram-positive bacterial species recovered. In both non-CF and CF subjects, THAM decreased the amount of Corynebacterium accolens detected, but increased the amount of Corynebacterium pseudodiphtheriticum recovered on nasal swabs. A reduction in Staphylococcus aureus nasal colonization was also found in subjects who grew C. pseudodiphtheriticum.

CONCLUSIONS: This study shows that aerosolized THAM is safe and well-tolerated and that nasal airway alkalinization alters the composition of mucosal bacterial communities.

CLINICAL TRIAL REGISTRATION: NCT00928135 (https://clinicaltrials.gov/ct2/show/NCT00928135).

PMID:34674574 | DOI:10.1177/00034894211051814

Biol Reprod. 2021 Oct 21:ioab194. doi: 10.1093/biolre/ioab194. Online ahead of print.

ABSTRACT

Congenital absence of the vas deferens (CAVD), a congenital malformation of the male reproductive system, causes obstructive azoospermia and male infertility. Currently, the cystic fibrosis transmembrane conductance regulator (CFTR) has been recognized as the main pathogenic gene in CAVD, with some other genes, such as adhesion G-protein coupled receptor G2 (ADGRG2), solute carrier family 9 isoform 3 (SLC9A3), sodium channel epithelial 1 subunit beta (SCNN1B), and carbonic anhydrase 12 (CA12) being candidate genes in the pathogenesis of CAVD. However, the frequency and spectrum of these mutations, as well as the pathogenic mechanisms of CAVD, have not been fully investigated. Here, we sequenced all genes with potentially pathogenic mutations using next-generation sequencing and verified all identified variants by Sanger sequencing. Further bioinformatic analysis was performed to predict the pathogenicity of mutations. We described the distribution of the p.V470M, poly-T, and TG-repeat CFTR polymorphisms, and identified novel missense mutations in the CFTR and SLC9A3 genes, respectively. Taken together, we identified mutations in the CFTR, ADGRG2, SLC9A3, SCNN1B, and CA12 genes in 22 patients with CAVD, thus broadening the genetic spectrum of Chinese patients with CAVD.

PMID:34673937 | DOI:10.1093/biolre/ioab194

Respir Med. 2021 Oct 12;189:106646. doi: 10.1016/j.rmed.2021.106646. Online ahead of print.

ABSTRACT

BACKGROUND: Elexacaftor/tezacaftor/ivacaftor (E/T/I) is a cystic fibrosis transmembrane conductance regulator (CFTR) triple combination therapy used for the treatment of cystic fibrosis (CF) in patients aged ≥12 years who have at least one copy of the Phe508del mutation (F) in the CFTR gene or another mutation that is responsive to treatment with E/T/I. This study determined the effectiveness and safety of E/T/I treatment in a cohort of CF patients.

METHODS: This retrospective cohort study collected data from the first 6 months of treatment of patients with CF, compound heterozygotes for the F and a minimal function (MF) mutations, enrolled in an E/T/I compassionate use program only available to patients having ppFEV1<40 or who are considered for lung transplantation. Forty-seven patients were included. Follow-up was performed after 1, 3, and 6 months from the beginning of therapy, assessing lung function, body mass index (BMI), sweat chloride concentration (SCC), quality of life (QoL), and safety.

RESULTS: After 6 months of treatment, the mean (standard deviation (SD)) SCC decreased from 91.1 (19.3) mmol/L to 46.2 (24.2) mmol/L. The decrease of SCC was accompanied by improvement of lung function (mean (95% Confidence Interval (CI) absolute increase in ppFEV1 was 10.69 (8.05,13.33) after 1 month and 14.16 (11.43, 16.89) after 6 months of treatment), nutrition (mean (SD) BMI increased from 20.7 (3.0) kg/m2 at baseline to 22.6 (3.1) after 6 months), and QoL. No safety concerns were observed.

CONCLUSIONS: E/T/I was clinically effective and safe in patients with advanced CF lung disease with an F/MF genotype.

PMID:34673344 | DOI:10.1016/j.rmed.2021.106646

Pediatr Pulmonol. 2021 Oct 21. doi: 10.1002/ppul.25734. Online ahead of print.

ABSTRACT

Airway clearance has been an integral part of cystic fibrosis (CF) care for almost as long as CF has been identified as a condition. From diagnosis as a neonate through to end-of-life care, airway clearance is an everyday aspect of life, adding a considerable treatment burden to the lives of people with CF. There are many different techniques used for airway clearance which have evolved over time with an aim to improve effectiveness, support adherence and, more recently, to consider the impact of burden. A popular thought is whether airway clearance could be replaced by exercise. With new precision therapies in the form of CFTR modulators available, the CF landscape is rapidly changing, raising the question of whether certain treatments are needed at all. Depending on factors such as CFTR mutation, age, and pre-existing lung damage before starting a CFTR modulator, individuals with CF may need different levels of intensity and type of maintenance treatment. Precision medicine is likely to lead to the need for increased precision and individualised management around other maintenance therapies such as airway clearance. This article is protected by copyright. All rights reserved.

PMID:34672434 | DOI:10.1002/ppul.25734

Pediatr Pulmonol. 2021 Oct 21. doi: 10.1002/ppul.25733. Online ahead of print.

ABSTRACT

Based on data from 2019, the Cystic Fibrosis Foundation Registry Report from the United States calculated the predicted median survival age of a child born that year with cystic fibrosis to be 48.4 years1 , a remarkable achievement. This article is protected by copyright. All rights reserved.

PMID:34672432 | DOI:10.1002/ppul.25733

J Inherit Metab Dis. 2021 Oct 21. doi: 10.1002/jimd.12450. Online ahead of print.

ABSTRACT

Inborn errors of metabolism (IEMs) comprise a diverse group of individually rare monogenic disorders that affect metabolic pathways. Mutations lead to enzymatic deficiency or dysfunction, which results in intermediate metabolite accumulation or deficit leading to disease phenotypes. Currently, treatment options for many IEMs are insufficient. Rarity of individual IEMs hampers therapy development and phenotypic and genetic heterogeneity suggest beneficial effects of personalized approaches. Recently, cultures of patient-own liver-derived intrahepatic cholangiocyte organoids (ICOs) have been established. Since most metabolic genes are expressed in the liver, patient-derived ICOs represent exciting possibilities for in vitro modelling and personalized drug testing for IEMs. However, the exact application range of ICOs remains unclear. To address this, we examined which metabolic pathways can be studied with ICOs and what the potential and limitations of patient-derived ICOs are to model metabolic functions. We present functional assays in patient ICOs with defects in branched-chain amino acid metabolism (methylmalonic acidemia), copper metabolism (Wilson disease) and transporter defects (cystic fibrosis). We discuss the broad range of functional assays that can be applied to ICOs, but also address the limitations of these patient-specific cell models. In doing so, we aim to guide the selection of the appropriate cell model for studies of a specific disease or metabolic process. This article is protected by copyright. All rights reserved.

PMID:34671987 | DOI:10.1002/jimd.12450