CFTR knockdown stimulates lipid synthesis and transport in intestinal Caco-2/15 cells

2009 ◽  
Vol 297 (6) ◽  
pp. G1239-G1249 ◽  
Author(s):  
Geneviève Mailhot ◽  
Zaava Ravid ◽  
Soraya Barchi ◽  
Alain Moreau ◽  
Rémi Rabasa-Lhoret ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pancreatic Insufficiency ◽  
Scavenger Receptor ◽  
Lipid Synthesis ◽  
Cftr Gene ◽  
Nutritional Deficiencies ◽  
Type I ◽  
Protein Activity ◽  
Fat Malabsorption ◽  
The Impact

Cystic fibrosis transmembrane conductance regulator (CFTR) is a chloride channel highly expressed in epithelial cells of the gastrointestinal tract. Mutations in the CFTR gene cause cystic fibrosis (CF), a disease characterized by pancreatic insufficiency, fat malabsorption, and steatorrhea. Despite the administration of pancreatic enzymes to normalize malabsorption, CF patients still experienced lipid fecal loss, nutritional deficiencies, and abnormalities in serum lipid profile, suggesting the presence of intrinsic defects in the intestinal handling of nutrients. The objective of the present study was to assess the impact of CFTR gene knockdown on intracellular lipid metabolism of the intestinal Caco-2/15 cell line. Partial CFTR gene inactivation led to cellular lipid accretion of phospholipids, triglycerides, and cholesteryl esters. Likewise, secretion of these lipid fractions was significantly increased following CFTR gene manipulation. As expected from these findings, the output of triglyceride-rich lipoproteins showed the same increasing pattern. Investigation of the mechanisms underlying these changes revealed that CFTR knockdown resulted in raised levels of apolipoproteins in cells and media and microsomal transfer protein activity, two important factors for the efficient assembly and secretion of lipoproteins. Similarly, scrutiny of the enzymatic monoacylglycerol acyltransferase and diacylglycerol acyltransferase, which exhibit dynamic function in triacylglycerol resynthesis and chylomicron formation in enterocytes, revealed a significant augmentation in their activity. Conversely, cholesterol uptake mediated by Niemann-Pick C1 like 1, Scavenger Receptor Class B Type I, and ATP-binding cassette G8 remains unaffected by genetic modification of CFTR. Collectively, these results highlight the role played by CFTR in intestinal handling of lipids and may suggest that factors other than defective CFTR are responsible for the abnormal intracellular events leading to fat malabsorption in CF patients.

Targeted therapy for cystic fibrosis

2021 ◽  
Vol 31 (2) ◽  
pp. 226-236
Author(s):  
S. I. Kutsev ◽  
V. L. Izhevskaya ◽  
E. I. Kondratyeva
Keyword(s):  
Cystic Fibrosis ◽  
Pancreatic Insufficiency ◽  
Mutant Gene ◽  
Bronchial Tree ◽  
Cftr Gene ◽  
Protein Activity ◽  
Enzyme Preparations ◽  
Calorie Diet ◽  
Cftr Protein ◽  
Cftr Modulators

The basic therapy of cystic fibrosis is currently aimed at slowing down the pathological processes associated with a decrease in the CFTR protein activity (cystic fibrosis transmembrane conductance regulator) in the gastrointestinal tract and the respiratory system. The pancreatic insufficiency is well compensated by replacement therapy with microsphere enzyme preparations and a high-calorie diet rich in proteins and fat. Chronic treatment of cystic fibrosis-related lung disease aims to improve the clearance of the bronchial tree, suppressing chronic bacterial infection and local chronic inflammation. However, no therapy was available to correct the defect in the gene or its product until 2012.The aim was to analyze literature on CFTR modulators, including their efficacy and safety, and assess the potential for developing new modulators to treat cystic fibrosis.Materials. The review included literature data (45 publications) on the use of CFTR modulators and international websites’ data.Results. Since the discovery of the CFTR gene in 1989, more than 2000 mutations or variants of the CFTR gene (hereinafter referred to as genetic variants) have been described. They interfere with the synthesis of the CFTR protein, its transport to the apical membrane of the cell, or disrupt its function as a channel for chloride anions. Although it is currently not possible to completely replace the mutant gene with a normal copy, small molecules have been identified that can modify the mutant CFTR protein and amend its function. The potential therapeutic measures are determined by class of the mutation. In clinical practice, pharmacological modeling of ion transport is currently possible only with the use of CFTR modulators: correctors and potentiators. The review defines these groups of drugs and describes 4 licensed CFTR modulators, including molecules of ivacaftor, lumacaftor, tezacaftor, elexacaftor. The data on the promising emerging next generation modulators and the prospects for the personalized selection of drugs using the assays on intestinal organoids are presented.

Clinical and genetic characteristics of rare pathogenic variants of the CFTR gene in Russian patients with cystic fibrosis

2021 ◽  
Vol 31 (2) ◽  
pp. 148-158
Author(s):  
A. Yu. Voronkova ◽  
Yu. L. Melyanovskaya ◽  
N. V. Petrova ◽  
T. A. Adyan ◽  
E. K. Zhekaite ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Genetic Variants ◽  
Pancreatic Insufficiency ◽  
Protein Energy Malnutrition ◽  
Molecular Genetic ◽  
Clinical Manifestations ◽  
Cftr Gene ◽  
Genetic Characteristics ◽  
Missense Variants ◽  
Pathogenic Variants

The variety of clinical manifestations of cystic fibrosis is driven by the diversity of the CFTR gene nucleotide sequence. Descriptions of the clinical manifestations in patients with the newly identified genetic variants are of particular interest.The aim of this study was to describe clinical manifestations of the disease with the newly identified genetic variants.Methods. Data from Registry of patients with cystic fibrosis in the Russian Federation (2018) were used. The data review included three steps — the search for frequent mutations, Sanger sequencing, and the search for extensive rearrangements by MLPA. 38 pathogenic variants were identified that were not previously described in the international CFTR2 database. We selected and analyzed full case histories of 15 patients with 10 of those 38 pathogenic variants: p.Tyr84*, G1047S, 3321delG, c.583delC, CFTRdele13,14del18, CFTRdele19-22, c.2619+1G>A, c.743+2T>A, p.Glu1433Gly, and CFTRdel4-8del10-11.Results. A nonsense variant p.Tyr84* was found in 5 patients (0.08 %). Two missense variants c.3139G>A were found in 2 siblings (0.03 %). The c.4298A>G was found in 1 patient. Other variants were detected in a single patient (0.02 %) each. They included two variants of a deletion with a shift of the reading frame 3321delG and c.583delC, two splicing disorders c.2619+1G>A and c.743+2T>A, three extended rearrangements CFTRdele19-22, CFTRdele13,14del18, and CFTRdel4-8del10-11. The last two variants include 2 rearrangements on one allele, which cause the severe course in two young children. 8 of the 10 variants are accompanied by pancreatic insufficiency (PI). Among patients with p.Tyr84*, one had ABPA, one had liver transplantation, and all had Pseudomonas aeruginosa infection. Nasal polyps were diagnosed in 2 patients with p.Tyr84*, 1 with G1047S, 1 with CFTRdel4-8del10-11, and 1 patient with 3321delG, who also had osteoporosis and cystic fibrosis-related diabetes (CFRD). 2 patients with PI with 3321delG and CFTRdel4-8del10-11 genetic variants, and 1 with PI with p.Glu1433Gly genetic variant had severe protein-energy malnutrition (PEM).Conclusion. Clinical manifestations of previously undescribed CFTR genetic variants were described. 5/10 genetic variants should be attributed to class I, 3/10 – to class 7 of the function classification of pathogenic CFTR gene variants associated with transcription and translation disruptions. Class of the identified missense variants c.3139G>A and c.4298A>G has not been established and requires further functional, cultural, and molecular genetic studies.

scholarly journals Lung function over the life course of paediatric and adult patients with cystic fibrosis from a large multi-centre registry

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Arul Earnest ◽  
Farhad Salimi ◽  
Claire E. Wainwright ◽  
Scott C. Bell ◽  
Rasa Ruseckaite ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Lung Function ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Pancreatic Insufficiency ◽  
Forced Expiratory Volume ◽  
Rate Of Change ◽  
Data Registry ◽  
Mortality Outcome ◽  
The Impact

Abstract A key measure of lung function in people with Cystic Fibrosis (CF) is Forced Expiratory Volume in the first second FEV1 percent predicted (FEV1pp). This study aimed to address challenges in identifying predictors of FEV1pp, specifically dealing with non-linearity and the censoring effect of death. Data was obtained from a large multi-centre Australian Cystic Fibrosis Data Registry (ACFDR). A linear mixed model was used to study FEV1pp as the endpoint. There were 3655 patients (52.4% male) included in our study. Restricted cubic splines were used to fit the non-linear relationship between age of visit and FEV1pp. The following predictors were found to be significant in the multivariate model: age of patient at visit, BMI z-score, age interaction with lung transplantation, insulin dependent diabetes, cirrhosis/portal hypertension, pancreatic insufficiency, Pseudomonas aeruginosa infection and baseline variability in FEV1pp. Those with P. aeruginosa infection had a lower mean difference in FEV1pp of 4.7 units, p < 0.001 compared to those who did not have the infection. Joint modelling with mortality outcome did not materially affect our findings. These models will prove useful for to study the impact of CFTR modulator therapies on rate of change of lung function among patients with CF.

Cystic Fibrosis and Chiari Type I Malformation: Autopsy Study of Two Infants with a Rare Association

2003 ◽  
Vol 6 (1) ◽  
pp. 88-93 ◽  
Author(s):  
Dinesh Rakheja ◽  
Yin Xu ◽  
Dennis K. Burns ◽  
Daniel L. Veltkamp ◽  
Linda R. Margraf
Keyword(s):  
Cystic Fibrosis ◽  
Mutational Analysis ◽  
Chiari I Malformation ◽  
Cftr Gene ◽  
Type I ◽  
Autopsy Study ◽  
Recurrent Pneumonia ◽  
Cftr Mutations ◽  
Chiari I ◽  
American Children

Cystic fibrosis (CF), an epithelial cell transport disorder caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, is not generally associated with malformations of the central nervous system (CNS). This report describes two African-American children who died at less than 2 years of age with known Chiari I malformations and were found, unexpectedly at autopsy, to have the classic pancreatic and respiratory changes of CF. Both patients had suffered from failure to thrive that had been attributed to their CNS malformations. One child also had recurrent pneumonia and died with Pseudomonas sepsis. Mutational analysis for > 70 common CFTR mutations identified a single delta F508 mutation in one patient and a single 3120 + 1G to A mutation in the other. Their second CFTR mutations were not identified. The association of CF with Chiari I malformation is not likely to be purely coincidental, as the probability of such an occurrence in African-Americans is greater than one in 7,500,000 patients. It is possible that the CFTR gene may play a previously unrecognized role in CNS development. Alternatively, this CNS abnormality may be acquired due to the metabolic and electrolyte imbalances that characteristically occur in CF.

scholarly journals Exocrine Pancreatic Insufficiency in Diabetic Patients: Prevalence, Mechanisms, and Treatment

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Matteo Piciucchi ◽  
Gabriele Capurso ◽  
Livia Archibugi ◽  
Martina Maria Delle Fave ◽  
Marina Capasso ◽  
...  
Keyword(s):  
Islet Cells ◽  
Pancreatic Insufficiency ◽  
Endocrine System ◽  
Exocrine Pancreatic Insufficiency ◽  
Exocrine Function ◽  
Diabetic Patients ◽  
Type I ◽  
Exocrine Insufficiency ◽  
Pancreatic Exocrine ◽  
The Impact

Pancreas is a doubled-entity organ, with both an exocrine and an endocrine component, reciprocally interacting in a composed system whose function is relevant for digestion, absorption, and homeostasis of nutrients. Thus, it is not surprising that disorders of the exocrine pancreas also affect the endocrine system and vice versa. It is well-known that patients with chronic pancreatitis develop a peculiar form of diabetes (type III), caused by destruction and fibrotic injury of islet cells. However, less is known on the influence of diabetes on pancreatic exocrine function. Pancreatic exocrine insufficiency (PEI) has been reported to be common in diabetics, with a prevalence widely ranging, in different studies, in both type I (25–74%) and type II (28–54%) diabetes. A long disease duration, high insulin requirement, and poor glycemic control seem to be risk factors for PEI occurrence. The impact of pancreatic exocrine replacement therapy on glycemic, insulin, and incretins profiles has not been fully elucidated. The present paper is aimed at reviewing published studies investigating the prevalence of PEI in diabetic patients and factors associated with its occurrence.

scholarly journals The Changing Epidemiology of Cystic Fibrosis: Incidence, Survival and Impact of the CFTR Gene Discovery

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 589 ◽  
Author(s):  
Virginie Scotet ◽  
Carine L’Hostis ◽  
Claude Férec
Keyword(s):  
Cystic Fibrosis ◽  
Cftr Gene ◽  
The Past ◽  
Responsible Gene ◽  
Family Testing ◽  
The Face ◽  
Serious Disease ◽  
Molecular Bases ◽  
The Impact ◽  
Clinical Advances

Significant advances in the management of cystic fibrosis (CF) in recent decades have dramatically changed the epidemiology and prognosis of this serious disease, which is no longer an exclusively pediatric disease. This paper aims to review the changes in the incidence and survival of CF and to assess the impact of the discovery of the responsible gene (the CFTR gene) on these changes. The incidence of CF appears to be decreasing in most countries and patient survival, which can be monitored by various indicators, has improved substantially, with an estimated median age of survival of approximately50 years today. Cloning of the CFTR gene 30 years ago and efforts to identify its many mutations have greatly improved the management of CF. Implementation of genetic screening policies has enabled earlier diagnosis (via newborn screening), in addition to prevention within families or in the general population in some areas (via prenatal diagnosis, family testing or population carrier screening). In the past decade, in-depth knowledge of the molecular bases of CF has also enabled the emergence of CFTR modulator therapies which have led to major clinical advances in the treatment of CF. All of these phenomena have contributed to changing the face of CF. The advent of targeted therapies has paved the way for precision medicine and is expected to further improve survival in the coming years.

scholarly journals Bruising as the first sign of exocrine pancreatic insufficiency

2019 ◽  
Author(s):  
Csilla Enikő Szabo ◽  
Oana Iulia Man ◽  
Radu Sorin Șerban ◽  
Eva Kiss ◽  
Călin Florin Lazăr
Keyword(s):  
Cystic Fibrosis ◽  
Vitamin K ◽  
Pancreatic Insufficiency ◽  
Pancreatic Enzyme ◽  
Exocrine Pancreatic Insufficiency ◽  
Nutritional Deficiencies ◽  
Deficiency Anemia ◽  
Serum Lipase ◽  
Pancreatic Elastase ◽  
Enzyme Replacement

Exocrine pancreatic insufficiency is an important cause of chronic malnutrition, secondary to maldigestion-malabsorption, which can be caused in children especially by cystic fibrosis, but also by other much rarer diseases. The case of a 6 months and 3 weeks old male pediatric patient is reported, who was admitted to the clinic for head and forearms bruising. Laboratory findings identified vitamin K deficiency as the cause of the cutaneous hemorrhagic syndrome. Further investigations revealed association of steatorrhea (which is a marker of fat malabsorption), iron-deficiency anemia and hypovitaminosis D, which had been produced by nutritional deficiencies caused by malabsorption syndrome. From the numerous disorders that could be associated with pancreatic insufficiency in children, the following conditions had been excluded: cystic fibrosis (mucoviscidosis), cow`s milk protein intolerance, gluten-sensitive enteropathy (coeliac disease), Shwachman-Diamond syndrome, abetalipoproteinemia, etc. Based upon decreased levels of stool pancreatic elastase in repeated measurements, together with low serum lipase, the final diagnosis of exocrine pancreatic insufficiency was established. Treatment of this case consisted mainly in pancreatic enzyme replacement therapy, but also oral iron supplementation and dietary supplements with fat-soluble vitamins (A, D, E, K). The outcome was favorable, characterized by normalization of intestinal passage, ascending growth curve and normalization of the majority of laboratory tests values that were modified between the time of patient admission to our clinic and initiation of specific therapy (serum level of vitamin K, vitamin D and lipase, coagulation profile, hemoglobin and red blood cell indexes), as well as higher value of fecal pancreatic elastase.    

scholarly journals Homozygous Deletion of the CFTR Gene Caused by Interstitial Maternal Isodisomy in a Peruvian Child with Cystic Fibrosis

2019 ◽  
Vol 08 (03) ◽  
pp. 147-152
Author(s):  
Flor Vásquez Sotomayor ◽  
Hugo Hernán Abarca-Barriga
Keyword(s):  
Cystic Fibrosis ◽  
Pancreatic Insufficiency ◽  
Chromosomal Rearrangements ◽  
Correct Diagnosis ◽  
Homozygous Deletion ◽  
Cftr Gene ◽  
Molecular Testing ◽  
Transmembrane Conductance Regulator ◽  
First Case ◽  
History Of

AbstractWe report the first case in Peru of cystic fibrosis caused by a homozygous deletion of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. A 10-month-old child who presented with meconium ileus and pancreatic insufficiency was tested for cystic fibrosis. Both parents of the child are of Peruvian background, are nonconsanguineous, and have no personal or family history of the disease. Chromosome microarray analysis revealed a homozygous deletion of the CFTR gene on chromosome 7 (7q31.2) within a maternally derived 12.8-Mb region of loss of heterozygosity with deletion of a region that includes the CFTR gene. Parental testing confirmed this finding. This case highlights the great importance of molecular testing and the study of chromosomal rearrangements in reaching a correct diagnosis and providing proper genetic counseling to the affected families.

scholarly journals The Impact on Genetic Testing of Mutational Patterns of CFTR Gene in Different Clinical Macrocategories of Cystic Fibrosis

2016 ◽  
Vol 18 (4) ◽  
pp. 554-565 ◽  
Author(s):  
Marco Lucarelli ◽  
Sabina M. Bruno ◽  
Silvia Pierandrei ◽  
Giampiero Ferraguti ◽  
Giancarlo Testino ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Genetic Testing ◽  
Cftr Gene ◽  
The Impact

scholarly journals Cystic fibrosis in Tuscany: evolution of newborn screening strategies over time to the present

2021 ◽  
Vol 47 (1) ◽  
Author(s):  
Matteo Botti ◽  
Vito Terlizzi ◽  
Michela Francalanci ◽  
Daniela Dolce ◽  
Maria Chiara Cavicchi ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Newborn Screening ◽  
Dna Analysis ◽  
Recall Rate ◽  
Previous Method ◽  
Cftr Gene ◽  
Allelic Heterogeneity ◽  
Predictive Values ◽  
The Impact ◽  
Over Time

Abstract Background Cystic fibrosis (CF) is a life-threatening disease affecting about 1:3000 newborns in Caucasian populations. The introduction of newborn screening for cystic fibrosis (CF NBS) has improved the clinical outcomes of individuals with CF through early diagnosis and early treatment. NBS strategies have been implemented over time. CF NBS was introduced extensively in 1984 in Tuscany, a region with 3.7 million people, characterized by a high allelic heterogeneity of CFTR gene. Aim and methods The aim of the study is to present the results from 34 years (1984–2018) of CF NBS, retrospectively evaluating the sensitivity, specificity and predictive values of the tests. In particular, we studied the impact of the introduction of DNA molecular analysis in NBS in a region with high allelic heterogeneity, such as Tuscany. Results Over these 34 years, 919,520 neonates were screened, using four different NBS strategies. From 1984 to 1991, CF NBS was performed by the determination of albumin on dried meconium (sensitivity 68.75%; specificity 99.82%). Subsequently, the analysis of immunoreactive trypsinogen on a blood spot was adopted as CF NBS protocol (sensitivity 83.33%; specificity 99.77%). From 1992 to 2010, this strategy was associated with lactase meconium dosage: IRT1/IRT2 + LACT protocol (sensitivity 87.50%; specificity 99.82%). From 2011, when the existing algorithm was integrated by analysis of CF causing variants of the CFTR gene (IRT1/IRT2 + LACT + IRT1/DNA protocol), a substantial improvement in sensitivity was seen (senisitivity 96.15%; specificity 99.75%). Other improved parameters with DNA analysis in the NBS programme, compared with the previous method, were the diagnosis time (52 days vs. 38 days) and the recall rate (0.58 to 0.38%). Conclusion The inclusion of DNA analysis in the NBS was a fundamental step in improving sensitivity, even in a region with high allelic variability.

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