Cell Models for Cystic Fibrosis: Comparison
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Please note this is a comparison between Version 2 by Camila Xu and Version 1 by Jessica Conti.

Cystic fibrosis (CF) is a autosomal recessive, multisystemic disease caused by different mutations in the CFTR gene encoding CF transmembrane conductance regulator.

  • CFTR
  • cystic fibrosis
  • organoids
  • theratyping

1. Introduction

Until a few years ago, treatments for Cystic Fibrosis (CF) were mainly based on relieving symptoms: physiotherapy to enhance airway clearance and combat lung infections and inflammation, nutritional status management and, in case of end-stage lung disease, lung transplantation. The fundamental current standards for CF therapy include pancreatic enzyme supplementation, fat-soluble vitamins and high-calorie ingestion to minimize pancreatic insufficiency and intestinal malabsorption, anti-inflammatory drugs, antibiotics and mucolytics [1][2][3]. Over the last decade, new therapeutic strategies have been proposed and a new class of drugs named CFTR modulators has been included in the therapeutic care of patients that are currently qualified for treatment. The development of new CF therapies has brought benefits in preventing disease complications, improving individual patient well-being and increasing survival rates. In fact, until the 1960s, CF was a fatal and incurable disease in infancy and today most people with CF are reaching adulthood. Pediatric mortality was dramatically reduced and the survival of CF patients has continuously improved with many individuals living up to 40–50 years in some countries today. Indeed, despite care being based on well-established guidelines, there are many health status disparities among CF patients according to healthcare systems, adherence to therapies, treatment type (route of administration, duration, number of daily medications, etc.), as well as patient socio-personal characteristics and genetic background [4]. Poor treatment adherence has been reported in CF and may lead to worse health outcomes and greater healthcare use. Because each patient is different in terms of lifestyle and social and economic aspects, individual motivational support and personalized educational/training courses can help the patient understand the importance of adhering to the therapeutic regimen to obtain the best clinical benefits. Developing a stronger relationship between patients, families/caregivers, and clinical CF researchers could be the first step to improving the therapeutic compliance of patients and relatives, especially critical in the case of children, and setting up a patient-oriented research infrastructure that promotes the translation of research into clinical impact.
The extensive knowledge obtained in this field has greatly modified the practices of care and outlook for CF pediatric patients. During the last 10 years, the use of newborn bloodspot screening (NBS) for the early diagnosis of children with CF has become widely adopted. Earlier diagnosis and CFTR-targeted therapies have led to efficient improvement of the quality of life. The increasing availability of CFTR-targeted drugs that may halt or severely reduce the disease progression and potentially interrupt the pathological sequences leading to CF organ complications provides the rationale for proposing early treatment (including during pregnancy) to reduce or prevent long-term consequences of the disease. As a result, a larger number of CF-affected children could start a treatment path even a few weeks after the birth, a well before showing symptoms or irreversible organ damage. Indeed, children who had access to earlier diagnosis, which means earlier access to medical management and intervention, show better health outcomes at an older age when compared to those children who had a later CF diagnosis [5][6]. The evidence supporting the clinical benefits of NBS programs have been extensively reviewed [7][8][9][10][11].
Furthermore, Szczesniak et al. [12] showed how lung function decline can be used as a parameter to identify individuals who have a higher potential to obtain an advantage whether from new therapies or those already available. For the possibility that the clinical manifestation of CF could be prevented, modulator therapy is increasingly used in younger children and even infants [13][14][15][16]. Over the last decade, significant efforts into high-throughput screening (HTS) of small molecule libraries have enabled the identification of CFTR modulators. CFTR modulator drugs have been described for the first time in 2003 [17]. Ivacaftor (Vertex Pharmaceuticals, MA, US) received a marketing authorization valid throughout the EU on 23 July 2012 (FDA approval on 31 January 2012) thus opening a new era in the treatment of this severe disease. The CFTR modulators currently available in clinic for CF are: ivacaftor, lumacaftor/ivacaftor, tezacaftor/ivacaftor, elexacaftor/tezacaftor/ivacaftor (Vertex Pharmaceuticals, MA, USA) and are currently revolutionizing the management of patients with CF, particularly those with at least one F508del variant (up to 85% of patients worldwide). These drugs primarily target CFTR variants that present a gating defect (class III variants) or a processing defect (Class II variants), but data in vitro and in vivo indicate how these drugs can be effective in other types of variants that affect CFTR function and/or processing.

2. Cell Models for Studying CF Disease Pathogenesis and Therapy

Experimental models based on the use of in vitro cell cultures have allowed for obtaining many and key information on the biological activity of the CFTR protein and its molecular defects, moreover they have permitted the screening of molecules with different pharmacological activities and to evaluate their pharmacological effects suggesting that cell response in vitro could be predict the clinical impact. Immortalized epithelial cell lines such as A549, BEAS-2B, Calu-3, CFBE41o- and 16HBE14o-, are suitable models, easy to culture and expand [18][19][20]. However, these immortalized cell lines are derived from lung tumor cells or have been transformed and therefore lack original lung cell characteristics and have some disadvantages due to immortalization strategy that can induce genetic instability, karyotype anomalies and altered gene expression [21][22]. Of note is the fact that drug therapy recovery intervention of CFTR mutations is greatly affected by the cell background [23][24][25]. Fischer Rat Thyroid (FRT) cells that ectopically express CFTR cDNA are the pre-clinical, high-throughput model that has been mostly used to successfully develop CFTR modulators. The recent FDA approval for label extension of ivacaftor and ivacaftor/tezacaftor/elexacaftor to patients with different mutations was based primarily on laboratory evidence of efficacy in FRT cells [26][27]. However, this cellular model has intrinsic limitations: FRT cells were developed from Fischer rat thyroid gland, as such its protein folding machinery is not human and this condition might affect the response to treatment [24]. It is equally clear that the same model cannot be minimally predictive of variations in intronic sequences, and that the transfection under an exogenous promoter might alter a proper protein level and processing. As a consequence, the observed effects might not closely match the in vivo situation. To evaluate individual CFTR modulators’ responses, several assays using CF patient-derived materials have been implemented and are widely used [28][29][30][31][32][33]. Ex-vivo individual-derived specimens, such as human bronchial epithelia (HBE), human nasal epithelial (HNE), intestinal organoids (OGs) and nasal as well as lung spheroids resemble parental organ epithelium morphology and functionality and reflect the complete genetic background of the subjects. These features permit uresearchers to come closer to evaluating the response in individual genetic backgrounds and are expected to better predict the clinical effectiveness of the given treatment. Primary HBE cells are typically obtained by invasive procedures (bronchoscopy or lung transplantation) from lungs with advanced/end-stage disease that may or may not reflect cells’ behavior in early disease. They are usually available in a limited number of severely ill patients so cannot be used for large-scale or theratyping studies. HNE cells seem to be a good surrogate for human bronchial epithelial cells. They are collected by minimal-invasive procedures such as nasal brushing or scraping of the lower turbinates. The current gold standard for modeling the primarily affected CF lung epithelium is air–liquid interface (ALI) culture of human nasal epithelial cells [29]. However, this nasal cell culture approach has some limitations: it requires a high number of cells, lengthy differentiation protocols, cells have limited ability to expand and HNE-derived cells are not necessarily representing the features of lower airways [34]. Nevertheless, in the last few years, several research groups have explored several approaches that allow for isolation, expansion, and differentiation of primary nasospheroids [30][35][36][37][38]. Recently a standardized protocol was proposed [39]. Nasal brush biopsies collection from infants through to adults is well known across most centers and can be performed with risk comparable to that of a nasopharyngeal swab for virus detection. In addition, the demonstration of the correlation between CFTR modulator responses in nasal and intestinal OGs provides early evidence that CFTR functional assay in nasal airway OGs can also be used to predict modulator efficacy in a genotype-dependent manner [38][40][41]. Another tissue representative of CF disease is the gastrointestinal tract which is affected in utero or early after birth by diseases such as meconium ileus and pancreatic insufficiency, the latter featuring typical pancreatic cysts after which the disease was named. Interestingly when nasal and intestinal mucosa were compared as in vivo biomarkers of CFTR function to distinguish people with CF (pwCF) and healthy controls, Intestinal Current Measurement (ICM) was found superior to Nasal Potential Difference (NPD) and ICM demonstrated substantially greater power than NPD to detect low levels of residual CFTR function [42][43] suggesting a potential superiority of intestinal over nasal mucosa for theratyping applications. In 2009, Sato et al. developed the basis for intestinal organoid technology [44] that recapitalized in-vivo tissue architecture forming three dimensional structures that can develop in a crypt-like epithelium [45]. In 2011, human intestinal OG cultures were described by the same group [46]. Organoid culture protocol requires a delicate balance of several growth factors such as Wnt, R-spondin and Noggin plus a specific basement membrane matrix. Intestinal OGs could be greatly expanded in vitro over long periods without losing their stemness and biobanked for future use without a need for genetic modifications or further patient inconvenience for repeated biopsies [46]. Human intestinal OG can be grown from intestinal crypt fragments isolated following a rectal biopsy procedure that causes only limited discomfort to patients being painless, usually well accepted by patients and feasible in people of all age groups (including newborns) without a need for anesthesia/sedation [47]. ICM in rectal biopsies have been included for decades in the diagnostic algorithm for CF and CFTR related disorders [48][49], in particular to aid establish or refute a diagnosis of CF in patients with equivocal sweat test or genetic testing results [50], and in many cases rectal samples can be used for generation of rectal OGs after ICM. Intestinal OGs remain the most advanced three-dimensional in vitro model for CF to date. Other than being a primary target organ in CF it is worth noting that CFTR represents the dominant channel responsible for ion and fluid secretion in gastrointestinal cells, which make intestinal OGs valuable models to investigate CFTR function and modulation [51][52][53]. Moreover, while the airways are significantly affected, the intestine is not significantly affected by chronic inflammation and infection with CF pathogens. Furthermore, the lack of significant chronic organ damage and remodeling in the intestine is a factor that reduces the chance to have CFTR channel function affected independently of the presence of CFTR variants [54]. Finally, intestinal OGs develop fast from the biopsy which results in a shorter time for readout, likely derived from the exceptionally high cell turnover in the intestinal epithelium that renews itself within 3–5 days.

References

  1. Castellani, C.; Duff, A.J.A.; Bell, S.C.; Heijerman, H.G.M.; Munck, A.; Ratjen, F.; Sermet-Gaudelus, I.; Southern, K.W.; Barben, J.; Flume, P.A.; et al. ECFS Best Practice Guidelines: The 2018 Revision. J. Cyst. Fibros. 2018, 17, 153–178.
  2. Athanazio, R.A.; Filho, L.V.R.F.S.; Vergara, A.A.; Ribeiro, A.F.; Riedi, C.A.; Procianoy, E.; Adde, F.V.; Reis, F.J.C.; Ribeiro, J.D.; Torres, L.A.; et al. Brazilian Guidelines for the Diagnosis and Treatment of Cystic Fibrosis. J. Bras. Pneumol. 2017, 43, 219–245.
  3. Cohen-Cymberknoh, M.; Shoseyov, D.; Kerem, E. Managing Cystic Fibrosis: Strategies That Increase Life Expectancy and Improve Quality of Life. Am. J. Respir. Crit. Care Med. 2011, 183, 1463–1471.
  4. Narayanan, S.; Mainz, J.G.; Gala, S.; Tabori, H.; Grossoehme, D. Adherence to Therapies in Cystic Fibrosis: A Targeted Literature Review. Expert Rev. Respir. Med. 2017, 11, 129–145.
  5. Campbell, P.W.; White, T.B. Newborn Screening for Cystic Fibrosis: An Opportunity to Improve Care and Outcomes. J. Pediatr. 2005, 147, S2–S5.
  6. Coffey, M.J.; Whitaker, V.; Gentin, N.; Junek, R.; Shalhoub, C.; Nightingale, S.; Hilton, J.; Wiley, V.; Wilcken, B.; Gaskin, K.J.; et al. Differences in Outcomes between Early and Late Diagnosis of Cystic Fibrosis in the Newborn Screening Era. J. Pediatr. 2017, 181, 137–145.
  7. Wagener, J.S.; Zemanick, E.T.; Sontag, M.K. Newborn Screening for Cystic Fibrosis. Curr. Opin. Pediatr. 2012, 24, 329–335.
  8. Rosenthal, M. Newborn Screening for Cystic Fibrosis: The Motion against—Voices in the Wilderness. Paediatr. Respir. Rev. 2008, 9, 295–300.
  9. McKay, K.; Wilcken, B. Newborn Screening for Cystic Fibrosis Offers an Advantage over Symptomatic Diagnosis for the Long Term Benefit of Patients: The Motion For. Paediatr. Respir. Rev. 2008, 9, 290–294.
  10. Southern, K.W.; Mérelle, M.M.E.; Dankert-Roelse, J.E.; Nagelkerke, A. Newborn Screening for Cystic Fibrosis. Cochrane Database Syst. Rev. 2009.
  11. Grosse, S.D.; Rosenfeld, M.; Devine, O.J.; Lai, H.J.; Farrell, P.M. Potential Impact of Newborn Screening for Cystic Fibrosis on Child Survival: A Systematic Review and Analysis. J. Pediatr. 2006, 149, 362–366.
  12. Szczesniak, R.D.; Li, D.; Su, W.; Brokamp, C.; Pestian, J.; Seid, M.; Clancy, J.P. Phenotypes of Rapid Cystic Fibrosis Lung Disease Progression during Adolescence and Young Adulthood. Am. J. Respir. Crit. Care Med. 2017, 196, 471–478.
  13. Rosenfeld, M.; Cunningham, S.; Harris, W.T.; Lapey, A.; Regelmann, W.E.; Sawicki, G.S.; Southern, K.W.; Chilvers, M.; Higgins, M.; Tian, S.; et al. An Open-Label Extension Study of Ivacaftor in Children with CF and a CFTR Gating Mutation Initiating Treatment at Age 2–5 Years (KLIMB). J. Cyst. Fibros. 2019, 18, 838–843.
  14. Rosenfeld, M.; Wainwright, C.E.; Higgins, M.; Wang, L.T.; McKee, C.; Campbell, D.; Tian, S.; Schneider, J.; Cunningham, S.; Davies, J.C.; et al. Ivacaftor Treatment of Cystic Fibrosis in Children Aged 12 to <24 Months and with a CFTR Gating Mutation (ARRIVAL): A Phase 3 Single-Arm Study. Lancet Respir. Med. 2018, 6, 545–553.
  15. Milla, C.E.; Ratjen, F.; Marigowda, G.; Liu, F.; Waltz, D.; Rosenfeld, M. Lumacaftor/Ivacaftor in Patients Aged 6–11 Years with Cystic Fibrosis and Homozygous for F508del-CFTR. Am. J. Respir. Crit. Care Med. 2017, 195, 912–920.
  16. Taylor-Cousar, J.L.; Munck, A.; McKone, E.F.; van der Ent, C.K.; Moeller, A.; Simard, C.; Wang, L.T.; Ingenito, E.P.; McKee, C.; Lu, Y.; et al. Tezacaftor–Ivacaftor in Patients with Cystic Fibrosis Homozygous for Phe508del. N. Engl. J. Med. 2017, 377, 2013–2023.
  17. Springsteel, M.F.; Galietta, L.J.V.; Ma, T.; By, K.; Berger, G.O.; Yang, H.; Dicus, C.W.; Choung, W.; Quan, C.; Shelat, A.A.; et al. Benzoflavone Activators of the Cystic Fibrosis Transmembrane Conductance Regulator: Towards a Pharmacophore Model for the Nucleotide-Binding Domain. Bioorg. Med. Chem. 2003, 11, 4113–4120.
  18. Gruenert, D.C.; Willems, M.; Cassiman, J.J.; Frizzell, R.A. Established Cell Lines Used in Cystic Fibrosis Research. J. Cyst. Fibros. 2004, 3, 191–196.
  19. Bednarski, C.; Tomczak, K.; vom Hövel, B.; Weber, W.-M.; Cathomen, T. Targeted Integration of a Super-Exon into the CFTR Locus Leads to Functional Correction of a Cystic Fibrosis Cell Line Model. PLoS ONE 2016, 11, e0161072.
  20. Bellec, J.; Bacchetta, M.; Losa, D.; Anegon, I.; Chanson, M.; Nguyen, T. CFTR Inactivation by Lentiviral Vector-Mediated RNA Interference and CRISPR-Cas9 Genome Editing in Human Airway Epithelial Cells. Curr. Gene Ther. 2015, 15, 447–459.
  21. Ehrhardt, C.; Collnot, E.-M.; Baldes, C.; Becker, U.; Laue, M.; Kim, K.-J.; Lehr, C.-M. Towards an in Vitro Model of Cystic Fibrosis Small Airway Epithelium: Characterisation of the Human Bronchial Epithelial Cell Line CFBE41o-. Cell Tissue Res. 2006, 323, 405–415.
  22. Lundberg, A.S.; Randell, S.H.; Stewart, S.A.; Elenbaas, B.; Hartwell, K.A.; Brooks, M.W.; Fleming, M.D.; Olsen, J.C.; Miller, S.W.; Weinberg, R.A.; et al. Immortalization and Transformation of Primary Human Airway Epithelial Cells by Gene Transfer. Oncogene 2002, 21, 4577–4586.
  23. Lopes-Pacheco, M.; Bacalhau, M.; Ramalho, S.S.; Silva, I.A.L.; Ferreira, F.C.; Carlile, G.W.; Thomas, D.Y.; Farinha, C.M.; Hanrahan, J.W.; Amaral, M.D. Rescue of Mutant CFTR Trafficking Defect by the Investigational Compound MCG1516A. Cells 2022, 11, 136.
  24. Pedemonte, N.; Tomati, V.; Sondo, E.; Galietta, L.J.V. Influence of Cell Background on Pharmacological Rescue of Mutant CFTR. Am. J. Physiol.-Cell Physiol. 2010, 298, C866–C874.
  25. Ostedgaard, L.S.; Rogers, C.S.; Dong, Q.; Randak, C.O.; Vermeer, D.W.; Rokhlina, T.; Karp, P.H.; Welsh, M.J. Processing and Function of CFTR-ΔF508 Are Species-Dependent. Proc. Natl. Acad. Sci. USA 2007, 104, 15370–15375.
  26. Durmowicz, A.G.; Lim, R.; Rogers, H.; Rosebraugh, C.J.; Chowdhury, B.A. The U.S. Food and Drug Administration’s Experience with Ivacaftor in Cystic Fibrosis. Establishing Efficacy Using In Vitro Data in Lieu of a Clinical Trial. Ann. Am. Thorac. Soc. 2018, 15, 1–2.
  27. Vertex Pharmaceuticals Inc. Highlights of Prescribing Information: Trikafta® (Elexacaftor/Tezacaftor/Ivacaftor). 2021. Available online: https://pi.vrtx.com/files/uspi_elexacaftor_tezacaftor_ivacaftor.pdf (accessed on 31 October 2022).
  28. Pranke, I.M.; Hatton, A.; Simonin, J.; Jais, J.P.; Le Pimpec-Barthes, F.; Carsin, A.; Bonnette, P.; Fayon, M.; Stremler-Le Bel, N.; Grenet, D.; et al. Correction of CFTR Function in Nasal Epithelial Cells from Cystic Fibrosis Patients Predicts Improvement of Respiratory Function by CFTR Modulators. Sci. Rep. 2017, 7, 7375.
  29. Gianotti, A.; Delpiano, L.; Caci, E. In Vitro Methods for the Development and Analysis of Human Primary Airway Epithelia. Front. Pharmacol. 2018, 9, 1176.
  30. Sachs, N.; Papaspyropoulos, A.; Zomer-van Ommen, D.D.; Heo, I.; Böttinger, L.; Klay, D.; Weeber, F.; Huelsz-Prince, G.; Iakobachvili, N.; Amatngalim, G.D.; et al. Long-term Expanding Human Airway Organoids for Disease Modeling. EMBO J. 2019, 38, e100300.
  31. Vonk, A.M.; van Mourik, P.; Ramalho, A.S.; Silva, I.A.L.; Statia, M.; Kruisselbrink, E.; Suen, S.W.F.; Dekkers, J.F.; Vleggaar, F.P.; Houwen, R.H.J.; et al. Protocol for Application, Standardization and Validation of the Forskolin-Induced Swelling Assay in Cystic Fibrosis Human Colon Organoids. STAR Protoc. 2020, 1, 100019.
  32. de Courcey, F.; Zholos, A.V.; Atherton-Watson, H.; Williams, M.T.S.; Canning, P.; Danahay, H.L.; Elborn, J.S.; Ennis, M. Development of Primary Human Nasal Epithelial Cell Cultures for the Study of Cystic Fibrosis Pathophysiology. Am. J. Physiol.-Cell Physiol. 2012, 303, C1173–C1179.
  33. Dekkers, J.F.; Wiegerinck, C.L.; de Jonge, H.R.; Bronsveld, I.; Janssens, H.M.; de Winter-de Groot, K.M.; Brandsma, A.M.; de Jong, N.W.M.; Bijvelds, M.J.C.; Scholte, B.J.; et al. A Functional CFTR Assay Using Primary Cystic Fibrosis Intestinal Organoids. Nat. Med. 2013, 19, 939–945.
  34. Scudieri, P.; Musante, I.; Venturini, A.; Guidone, D.; Genovese, M.; Cresta, F.; Caci, E.; Palleschi, A.; Poeta, M.; Santamaria, F.; et al. Ionocytes and CFTR Chloride Channel Expression in Normal and Cystic Fibrosis Nasal and Bronchial Epithelial Cells. Cells 2020, 9, 2090.
  35. Sette, G.; Lo Cicero, S.; Blaconà, G.; Pierandrei, S.; Bruno, S.M.; Salvati, V.; Castelli, G.; Falchi, M.; Fabrizzi, B.; Cimino, G.; et al. Theratyping Cystic Fibrosis in Vitro in ALI Culture and Organoid Models Generated from Patient-Derived Nasal Epithelial Conditionally Reprogrammed Stem Cells. Eur. Respir. J. 2021, 58, 2100908.
  36. Barkauskas, C.E.; Chung, M.-I.; Fioret, B.; Gao, X.; Katsura, H.; Hogan, B.L.M. Lung Organoids: Current Uses and Future Promise. Development 2017, 144, 986–997.
  37. Liu, Z.; Anderson, J.D.; Deng, L.; Mackay, S.; Bailey, J.; Kersh, L.; Rowe, S.M.; Guimbellot, J.S. Human Nasal Epithelial Organoids for Therapeutic Development in Cystic Fibrosis. Genes 2020, 11, 603.
  38. Amatngalim, G.D.; Rodenburg, L.W.; Aalbers, B.L.; Raeven, H.H.; Aarts, E.M.; Sarhane, D.; Spelier, S.; Lefferts, J.W.; Silva, I.A.; Nijenhuis, W.; et al. Measuring Cystic Fibrosis Drug Responses in Organoids Derived from 2D Differentiated Nasal Epithelia. Life Sci. Alliance 2022, 5, e202101320.
  39. Golec, A.; Pranke, I.; Scudieri, P.; Hayes, K.; Dreano, E.; Dunlevy, F.; Hatton, A.; Downey, D.G.; Galietta, L.; Sermet, I. Isolation, Cultivation, and Application of Primary Respiratory Epithelial Cells Obtained by Nasal Brushing, Polyp Samples, or Lung Explants. STAR Protoc. 2022, 3, 101419.
  40. Wong, S.L.; Awatade, N.T.; Astore, M.A.; Allan, K.M.; Carnell, M.J.; Slapetova, I.; Chen, P.; Setiadi, J.; Pandzic, E.; Fawcett, L.K.; et al. Molecular Dynamics and Theratyping in Airway and Gut Organoids Reveal R352Q-CFTR Conductance Defect. Am. J. Respir Cell Mol. Biol. 2022, 67, 99–111.
  41. Silva, I.A.L.; Railean, V.; Duarte, A.; Amaral, M.D. Personalized Medicine Based on Nasal Epithelial Cells: Comparative Studies with Rectal Biopsies and Intestinal Organoids. J. Pers. Med. 2021, 11, 421.
  42. Clancy, J.P.; Szczesniak, R.D.; Ashlock, M.A.; Ernst, S.E.; Fan, L.; Hornick, D.B.; Karp, P.H.; Khan, U.; Lymp, J.; Ostmann, A.J.; et al. Multicenter Intestinal Current Measurements in Rectal Biopsies from CF and Non-CF Subjects to Monitor CFTR Function. PLoS ONE 2013, 8, e73905.
  43. Bagheri-Hanson, A.; Nedwed, S.; Rueckes-Nilges, C.; Naehrlich, L. Intestinal Current Measurement versus Nasal Potential Difference Measurements for Diagnosis of Cystic Fibrosis: A Case–Control Study. BMC Pulm. Med. 2014, 14, 156.
  44. Sato, T.; Vries, R.G.; Snippert, H.J.; van de Wetering, M.; Barker, N.; Stange, D.E.; van Es, J.H.; Abo, A.; Kujala, P.; Peters, P.J.; et al. Single Lgr5 Stem Cells Build Crypt-Villus Structures in Vitro without a Mesenchymal Niche. Nature 2009, 459, 262–265.
  45. Sato, T.; Clevers, H. Growing Self-Organizing Mini-Guts from a Single Intestinal Stem Cell: Mechanism and Applications. Science 2013, 340, 1190–1194.
  46. Sato, T.; Stange, D.E.; Ferrante, M.; Vries, R.G.J.; van Es, J.H.; van den Brink, S.; van Houdt, W.J.; Pronk, A.; van Gorp, J.; Siersema, P.D.; et al. Long-Term Expansion of Epithelial Organoids From Human Colon, Adenoma, Adenocarcinoma, and Barrett’s Epithelium. Gastroenterology 2011, 141, 1762–1772.
  47. Servidoni, M.F.; Sousa, M.; Vinagre, A.M.; Cardoso, S.R.; Ribeiro, M.A.; Meirelles, L.R.; de Carvalho, R.B.; Kunzelmann, K.; Ribeiro, A.F.; Ribeiro, J.D.; et al. Rectal Forceps Biopsy Procedure in Cystic Fibrosis: Technical Aspects and Patients Perspective for Clinical Trials Feasibility. BMC Gastroenterol. 2013, 13, 91.
  48. De Boeck, K. Cystic Fibrosis: Terminology and Diagnostic Algorithms. Thorax 2006, 61, 627–635.
  49. Sermet-Gaudelus, I.; Girodon, E.; Vermeulen, F.; Solomon, G.M.; Melotti, P.; Graeber, S.Y.; Bronsveld, I.; Rowe, S.M.; Wilschanski, M.; Tümmler, B.; et al. ECFS Standards of Care on CFTR-Related Disorders: Diagnostic Criteria of CFTR Dysfunction. J. Cyst. Fibros. 2022, 21, 922–936.
  50. Farrell, P.M.; White, T.B.; Ren, C.L.; Hempstead, S.E.; Accurso, F.; Derichs, N.; Howenstine, M.; McColley, S.A.; Rock, M.; Rosenfeld, M.; et al. Diagnosis of Cystic Fibrosis: Consensus Guidelines from the Cystic Fibrosis Foundation. J. Pediatr. 2017, 181, S4–S15.
  51. Kunzelmann, K.; Mall, M. Electrolyte Transport in the Mammalian Colon: Mechanisms and Implications for Disease. Physiol. Rev. 2002, 82, 245–289.
  52. Mall, M.; Wissner, A.; Seydewitz, H.H.; Kuehr, J.; Brandis, M.; Greger, R.; Kunzelmann, K. Defective Cholinergic Cl—Secretion and Detection of K + Secretion in Rectal Biopsies from Cystic Fibrosis Patients. Am. J. Physiol.-Gastrointest. Liver Physiol. 2000, 278, G617–G624.
  53. Veeze, H.J.; Sinaasappel, M.; Bijman, J.; Bouquet, J.; De Jonge, H.R. Ion Transport Abnormalities in Rectal Suction Biopsies from Children with Cystic Fibrosis. Gastroenterology 1991, 101, 398–403.
  54. Graeber, S.Y.; Vitzthum, C.; Mall, M.A. Potential of Intestinal Current Measurement for Personalized Treatment of Patients with Cystic Fibrosis. J. Pers. Med. 2021, 11, 384.
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