scholarly journals Use of a High-Throughput Phenotypic Screening Strategy to Identify Amplifiers, a Novel Pharmacological Class of Small Molecules That Exhibit Functional Synergy with Potentiators and Correctors

2017 ◽  
Vol 23 (2) ◽  
pp. 111-121 ◽  
Author(s):  
Kenneth A. Giuliano ◽  
Shinichiro Wachi ◽  
Lawrence Drew ◽  
Danijela Dukovski ◽  
Olivia Green ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Small Molecules ◽  
High Throughput ◽  
Stress Responses ◽  
Genetic Disorder ◽  
Screening Strategy ◽  
New Class ◽  
Cftr Mutations ◽  
Cellular Stress Responses ◽  
Cftr Modulators

Cystic fibrosis (CF) is a lethal genetic disorder caused by mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Despite recent groundbreaking approval of genotype-specific small-molecule drugs, a significant portion of CF patients still lack effective therapeutic options that address the underlying cause of the disease. Through a phenotypic high-throughput screen of approximately 54,000 small molecules, we identified a novel class of CFTR modulators called amplifiers. The identified compound, the characteristics of which are represented here by PTI-CH, selectively increases the expression of immature CFTR protein across different CFTR mutations, including F508del-CFTR, by targeting the inefficiencies of early CFTR biosynthesis. PTI-CH also augments the activity of other CFTR modulators and was found to possess novel characteristics that distinguish it from CFTR potentiator and corrector moieties. The PTI-CH–mediated increase in F508del-CFTR did not elicit cytosolic or endoplasmic reticulum–associated cellular stress responses. Based on these data, amplifiers represent a promising new class of CFTR modulators for the treatment of CF that can be used synergistically with other CFTR modulators.

scholarly journals Fertility, Pregnancy and Lactation Considerations for Women with CF in the CFTR Modulator Era

2021 ◽  
Vol 11 (5) ◽  
pp. 418
Author(s):  
Raksha Jain ◽  
Jennifer L. Taylor-Cousar
Keyword(s):  
Cystic Fibrosis ◽  
Genetic Disorder ◽  
Signs And Symptoms ◽  
Bicarbonate Transport ◽  
New Class ◽  
Pregnancy And Lactation ◽  
Infection And Inflammation ◽  
Protein Dysfunction ◽  
The Impact ◽  
Cftr Modulators

Cystic fibrosis (CF) is an autosomal recessive genetic disorder impacting approximately 80,000 people of all races and ethnicities world-wide. CF is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene which encodes a protein of the same name. Protein dysfunction results in abnormal chloride and bicarbonate transport in mucus membranes, including those in the respiratory, gastrointestinal and reproductive tracts. Abnormal anion transport causes viscous secretions at the site of involvement. The majority of people with CF succumb to respiratory failure following recurrent cycles of infection and inflammation in the airways. Historically, providers treated the signs and symptoms of CF, but since 2012, have been able to impact the basic defect for the subset of people with CF who have mutations that respond to the new class of drugs, CFTR protein modulators. With the improved health and longevity afforded by CFTR modulators, more women are interested in parenthood and are becoming pregnant. Furthermore, this class of drugs likely increases fertility in women with CF. However, the safety of CFTR modulators in pregnancy and lactation is only beginning to be established. We summarize available data on the impact of CFTR modulators on fertility, pregnancy and lactation in women with CF.

scholarly journals Stressors and Stress Responses in Cystic Fibrosis

2018 ◽  
Vol 5 (1) ◽  
pp. 11-29 ◽  
Author(s):  
Zsuzsa Bebok ◽  
Lianwu Fu
Keyword(s):  
Cystic Fibrosis ◽  
Stress Response ◽  
Stress Responses ◽  
Genetic Disorder ◽  
Cellular Stress ◽  
Cellular Stress Response ◽  
Bicarbonate Transport ◽  
Persistent Infections ◽  
Human Disorders ◽  
The Unfolded Protein Response

Abstract Cystic fibrosis (CF) is a life-shortening, genetic disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR). The primary cause of CF is reduced CFTR-mediated chloride and bicarbonate transport, due to mutations in CFTR. However, inflammation and persistent infections influence clinical outcome. Cellular stress response pathways, such as the unfolded protein response (UPR) and the integrated stress response (ISR), referred to here as cellular stress response pathways (SRPs), contribute to the pathology of human disorders. Multiple studies have indicated activation of SRPs in CF tissues. We review our present understanding of how SRPs are activated in CF and their contribution to pathology. We conclude that reduced CFTR function in CF organs establishes a tissue environment in which internal or external insults activate SRPs. SRPs contribute to CF pathogenesis by reducing CFTR expression, enhancing inflammation with consequent tissue remodeling. Understanding the contribution of SRPs to CF pathogenesis is crucial even in the era of CFTR “modulators” that are designed to potentiate, correct or amplify CFTR function, since there is an urgent need for supportive treatments. Importantly, CF patients with established pathology could benefit from the targeted use of drugs that modulate SRPs to reduce the symptoms.

scholarly journals Airway Inflammation and Host Responses in the Era of CFTR Modulators

2020 ◽  
Vol 21 (17) ◽  
pp. 6379
Author(s):  
Karen Keown ◽  
Ryan Brown ◽  
Declan F. Doherty ◽  
Claire Houston ◽  
Michael C. McKelvey ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Lung Function ◽  
Lung Disease ◽  
Airway Inflammation ◽  
Host Responses ◽  
Current Evidence ◽  
Future Research ◽  
Clinical Endpoints ◽  
New Class ◽  
Cftr Modulators

The arrival of cystic fibrosis transmembrane conductance regulator (CFTR) modulators as a new class of treatment for cystic fibrosis (CF) in 2012 represented a pivotal advance in disease management, as these small molecules directly target the upstream underlying protein defect. Further advancements in the development and scope of these genotype-specific therapies have been transformative for an increasing number of people with CF (PWCF). Despite clear improvements in CFTR function and clinical endpoints such as lung function, body mass index (BMI), and frequency of pulmonary exacerbations, current evidence suggests that CFTR modulators do not prevent continued decline in lung function, halt disease progression, or ameliorate pathogenic organisms in those with established lung disease. Furthermore, it remains unknown whether their restorative effects extend to dysfunctional CFTR expressed in phagocytes and other immune cells, which could modulate airway inflammation. In this review, we explore the effects of CFTR modulators on airway inflammation, infection, and their influence on the impaired pulmonary host defences associated with CF lung disease. We also consider the role of inflammation-directed therapies in light of the widespread clinical use of CFTR modulators and identify key areas for future research.

Dihydroceramides: Their emerging physiological roles and functions in cancer and metabolic diseases

2020 ◽  
Author(s):  
Floriane Lachkar ◽  
Pascal Ferre ◽  
Fabienne Foufelle ◽  
Alexandra Papaioannou
Keyword(s):  
Stress Responses ◽  
Metabolic Diseases ◽  
De Novo ◽  
Metabolic Intermediates ◽  
New Class ◽  
Survival Pathways ◽  
Long Time ◽  
Cellular Stress Responses

Dihydroceramides are a type of sphingolipids that for a long time were regarded as biologically inactive. They are metabolic intermediates of the de novo sphingolipid synthesis pathway, and are converted into ceramides with the addition of a double bond. Ceramides are abundant in tissues and have well-established biological functions. On the contrary, dihydroceramides are less prevalent and despite their hitherto characterization as inert lipids, studies of the last decade begun to unravel their implication in various biological processes distinct from those involving ceramides. These processes include cellular stress responses and autophagy, cell growth, pro-death or pro-survival pathways, hypoxia and immune responses. In addition, their plasma concentration has been related to metabolic diseases and shown as a long-term predictor of type 2 diabetes onset. They are thus important players and potential biomarkers in pathologies ranging from diabetes to cancer and neurodegenerative diseases. The purpose of this mini-review is to highlight the emergence of dihydroceramides as a new class of bioactive sphingolipids by reporting recent advances on their biological characterization and pathological implications, focusing on cancer and metabolic diseases.

scholarly journals A Comprehensive Assay for CFTR Mutational Analysis Using Next-Generation Sequencing

2013 ◽  
Vol 59 (10) ◽  
pp. 1481-1488 ◽  
Author(s):  
Ahmad N Abou Tayoun ◽  
Christopher D Tunkey ◽  
Trevor J Pugh ◽  
Tristen Ross ◽  
Minita Shah ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Next Generation Sequencing ◽  
Mutational Analysis ◽  
Genetic Disorder ◽  
Sequencing Error ◽  
Personal Genome ◽  
Ion Torrent ◽  
Next Generation ◽  
Cftr Mutations ◽  
Generation Sequencing

BACKGROUND Cystic fibrosis is a life-threatening genetic disorder that has been associated with mutations in the CFTR [cystic fibrosis transmembrane conductance regulator (ATP-binding cassette sub-family C, member 7)] gene. Hundreds of CFTR mutations have been detected to date. Current CFTR genotyping assays target a subset of these mutations, particularly a mutation panel recommended by the American College of Medical Genetics for carrier screening of the general population. Fast sequencing of the entire coding sequence in a scalable manner could expand the detection of CFTR mutations and facilitate management of costs and turnaround times in the clinical laboratory. METHODS We describe a proof-of-concept CFTR assay that uses PCR target enrichment and next-generation sequencing on the Ion Torrent Personal Genome Machine™ (PGM™) platform. RESULTS The scalability of the assay was demonstrated, with an average mean depth of coverage ranging from 500× to 3500×, depending on the number of multiplexed patient samples and the Ion Torrent chip used. In a blinded study of 79 previously genotyped patient DNA samples and cell lines, our assay detected most of the mutations, including single-nucleotide variants, small insertions and deletions, and large copy-number variants. The reproducibility was 100% for detecting mutations in independent runs. Our assay demonstrated high specificity, with only 2 false-positive calls (at 2184delA) found in 2 samples caused by a sequencing error in a homopolymer stretch of sequence. The detection rate for variants of unknown significance was very low in the targeted region. CONCLUSIONS With continued optimization and system refinements, PGM sequencing promises to be a powerful, rapid, and scalable means of clinical diagnostic sequencing.

Targeting Cystic Fibrosis Inflammation in the Age of CFTR Modulators: Focus on Macrophages

2020 ◽  
pp. 2003502
Author(s):  
Jonathan L. Gillan ◽  
Donald J. Davidson ◽  
Robert D. Gray
Keyword(s):  
Cystic Fibrosis ◽  
Direct Result ◽  
Transmembrane Conductance Regulator ◽  
Lung Function Decline ◽  
New Class ◽  
Absolute Requirement ◽  
Integral Role ◽  
Airway Response ◽  
Anti Inflammatory ◽  
Cftr Modulators

Cystic fibrosis is a life-shortening, multiorgan, autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The most prominent clinical manifestation in CF is the development of progressive lung disease characterised by an intense, chronic inflammatory airway response that culminates in respiratory failure, and ultimately death. In recent years, a new class of therapeutics which have the potential to correct the underlying defect in CF, known as CFTR modulators, have revolutionised the field. Despite the exciting success of these drugs, their impact on airway inflammation, and its long-term consequences, remain undetermined. In addition, studies querying the absolute requirement for infection as a driver of CF inflammation have challenged the traditional consensus on CF pathogenesis, and also emphasise the need to prioritise complementary anti-inflammatory treatments in CF. Macrophages, often overlooked in CF research despite their integral role in other chronic inflammatory pathologies, have increasingly become recognised as key players in the initiation, perpetuation, and resolution of CF lung inflammation, perhaps as a direct result of CFTR dysfunction. These findings suggest that macrophages may be an important target for novel anti-inflammatory interventional strategies to effectively treat CF lung function decline. This review will consider evidence for the efficacy for anti-inflammatories in the treatment of CF, the potential role of macrophages, and the significance of targeting these pathways at a time when rectifying the basic defect in CF, through use of novel CFTR modulator therapies, is becoming increasingly viable.

scholarly journals Development of a High-Throughput Screening Strategy for Upregulators of the OPG/RANKL Ratio with the Potential for Antiosteoporosis Effects

2016 ◽  
Vol 21 (7) ◽  
pp. 738-748 ◽  
Author(s):  
Shiqiang Gong ◽  
Xiaowan Han ◽  
Xuehong Li ◽  
Jun Yang ◽  
Xiaobo He ◽  
...  
Keyword(s):  
Small Molecules ◽  
High Throughput ◽  
High Throughput Screening ◽  
Firefly Luciferase ◽  
Screening Strategy ◽  
Effective Concentration ◽  
Renilla Luciferase ◽  
Bone Microenvironment ◽  
Receptor Activator

The ratio between osteoprotegerin (OPG) and the receptor activator of NF-κB ligand (RANKL) in the bone microenvironment indicates the level of osteoclastogenesis, and upregulation of this ratio would improve osteoporosis. In this study, we established a novel high-throughput screening (HTS) system using two stably transfected monoclonal cell lines that either express firefly luciferase under the OPG promoter control or concurrently express firefly and renilla luciferases under control of the OPG and RANKL promoters, respectively. With this system, we can conveniently and rapidly detect the effects of compounds on the expression of OPG and RANKL through changes in firefly and renilla luciferase activities. A total of 8160 compounds were screened using this system, yielding five compounds without previously reported activity. The compound with greatest potential is E05657 with high activity and low effective concentration in the HTS system. It increases the OPG/RANKL ratio and OPG secretion, decreases the NFATc1 expression, and reduces osteoclastogenesis in vitro. These results indicate that this novel HTS system can be used to identify small molecules with potential antiosteoporosis effects, and E05657 is a promising lead compound as a novel antiosteoporosis drug.

scholarly journals CFTR Modulators: Impact on Fertility, Pregnancy, and Lactation in Women with Cystic Fibrosis

2020 ◽  
Vol 9 (9) ◽  
pp. 2706 ◽  
Author(s):  
Jennifer L. Taylor-Cousar
Keyword(s):  
Quality Of Life ◽  
Cystic Fibrosis ◽  
Genetic Disorder ◽  
Safety Data ◽  
Single Copy ◽  
The Body ◽  
Pregnancy And Lactation ◽  
The Impact ◽  
Cftr Modulators

Cystic fibrosis (CF) is a life-shortening genetic disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. These mutations lead to abnormal ion transport in mucous membranes throughout the body, including in the respiratory and gastrointestinal and reproductive tracts. Improvements in care and therapy have led to substantial increases in the quantity and quality of life for those with CF. Consequently, women with CF are increasingly interested in having families. Although pregnancy was once discouraged for women with CF, at this point, even women with moderately severe lung disease can successfully navigate pregnancy. With the recent approval of a triple combination CFTR modulator therapy that improves lung function, nutritional status, and quality of life for people with a single copy of the most common CFTR mutation, it is expected that the number of women with CF who choose to become pregnant will continue to increase. Although animal reproduction models show no alarming signals for use during pregnancy at normal human doses, there is a paucity of human safety data in pregnancy and lactation. This review summarizes what is currently known about the impact of use of CFTR modulators on fertility, pregnancy, and lactation in women with CF.

Screening for cystic fibrosis in newborn infants: results of a pilot programme based on a two tier protocol (IRT/DNA/IRT) in the Italian population

2002 ◽  
Vol 9 (2) ◽  
pp. 60-63 ◽  
Author(s):  
C. Corbetta ◽  
M. Seia ◽  
A. Bassotti ◽  
A. Ambrosioni ◽  
A. Giunta ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Newborn Infants ◽  
Dried Blood Spots ◽  
Screening Strategy ◽  
Sweat Test ◽  
Italian Population ◽  
Screening Protocol ◽  
Oligonucleotide Ligation Assay ◽  
Cftr Mutations ◽  
Immunoreactive Trypsinogen

OBJECTIVE: To assess the performance of a two tier neonatal screening programme (IRT/DNA/IRT) for cystic fibrosis, based on immunoreactive trypsinogen (IRT) followed by direct cystic fibrosis transmembrane conductance regulator (CFTR) gene analysis (based on a panel of up to 31 mutations) in hypertrypsinaemic newborn infants and to compare it with a previous screening protocol. SETTING: The study comprised all the newborn infants in the period 1 October 1998 to 31 December 1999 in the Lombardia region, north western Italy. METHODS: The screening strategy consisted of an immunoreactive trypsinogen assay from dried blood spots, a polymerase chain reaction (PCR) followed by an oligonucleotide ligation assay (PCR-OLA), and a sequence code separation. RESULTS: 104 609 newborn infants were screened. 1457 hypertrypsinaemic infants (1.39%) were analysed with the PCR-OLA assay. 18 newborn homozygotes or compound heterozygotes for CFTR mutations were identified and referred to the cystic fibrosis (CF) centre at a mean age of 3 weeks. 125 infants presenting only one mutation were recalled for a sweat test: a diagnosis of CF was made in 13 infants, and parents of 112 neonates identified as carriers (1:13) received genetic counselling. The remaining 1314 hypertrypsinaemic newborn infants were recalled for IRT retesting and 177 were referred for a sweat test because the second IRT measurement was above the cut off value. Among this group a further two infants were diagnosed with CF (1.1%) leading to a CF prevalence of 1:3170. CONCLUSIONS: This strategy resulted in an early and accurate diagnosis of CF. The IRT/DNA/IRT protocol with an OLA assay was shown to be useful in an Italian population with a genetic heterogeneity, leading to the identification of 94% of infants with CF.

scholarly journals Therapeutic Approaches for Patients with Cystic Fibrosis Not Eligible for Current CFTR Modulators

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2793
Author(s):  
Isabelle Fajac ◽  
Isabelle Sermet
Keyword(s):  
Cystic Fibrosis ◽  
Protein Function ◽  
Protein A ◽  
Autosomal Recessive Disorder ◽  
New Drugs ◽  
Gene Encoding ◽  
Disease Modifying Drugs ◽  
Cftr Mutations ◽  
Cftr Protein ◽  
Cftr Modulators

Cystic fibrosis is a severe autosomal recessive disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene encoding the CFTR protein, a chloride channel expressed in many epithelial cells. New drugs called CFTR modulators aim at restoring the CFTR protein function, and they will benefit many patients with cystic fibrosis in the near future. However, some patients bear rare mutations that are not yet eligible for CFTR modulators, although they might be amenable to these new disease-modifying drugs. Moreover, more than 10% of CFTR mutations do not produce any CFTR protein for CFTR modulators to act upon. The purpose of this review is to provide an overview of different approaches pursued to treat patients bearing mutations ineligible for CFTR modulators. One approach is to broaden the numbers of mutations eligible for CFTR modulators. This requires developing strategies to evaluate drugs in populations bearing very rare genotypes. Other approaches aiming at correcting the CFTR defect develop new mutation-specific or mutation-agnostic therapies for mutations that do not produce a CFTR protein: readthrough agents for nonsense mutations, nucleic acid-based therapies, RNA- or DNA-based, and cell-based therapies. Most of these approaches are in pre-clinical development or, for some of them, early clinical phases. Many hurdles and challenges will have to be solved before they can be safely translated to patients.

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