Mutations In CFTR Gene Research Articles

Population Characteristics of the Spectrum and Frequencies of CFTR Gene Mutations in Patients with Cystic Fibrosis from the Republic of Bashkortostan (Russia).

Cystic fibrosis (CF) is one of the most common autosomal-recessive disorders worldwide. The incidence of CF depends on the prevalence of cystic fibrosis transmembrane conductance regulator gene (CFTR) mutations in the population, which is determined by genetic diversity and ethnicity. The search for the causes of mutations in the transmembrane conductance regulator gene (CFTR) was carried out using targeted next-generation sequencing (NGS) on the Illumina platform in patients with cystic fibrosis from the Republic of Bashkortostan (Russia), taking into account the ethnic structure of the sample. A total of 35 distinct causal variants were found in 139 cases from 129 families. Five (F508del, E92K, 3849+10kbC>T, CFTRdele2.3, L138ins) explain 78.7% of identified CF causal alleles. Variants N13103K and 394delTT were found in four families each. Variants 2143delT, S1196X, W1282X, Y84X, G194R, and 1525-1G>A, as well as the two previously described complex alleles-c. [S466X; R1070Q] and str.[G509D;E217G]-were found in two or three families each. Twenty additional variants occurred only once. Variant c.3883_3888dup has not been described previously. Thus, regional and ethnic features were identified in the spectrum of frequencies of pathogenic variants of the CFTR gene in the three major sub-groups of patients-Russians, Tatars, and Bashkirs. Taking into account these results, highlighting the genetic specificity of the region, a more efficient search for CFTR mutations in patients can be performed. In particular it is possible to choose certain test kits for quick and effective genetic screening before use of NGS sequencing.

Dynamics of inflammatory markers in patients with normal and impaired glucose metabolism during lung exacerbation treatment

Cystic fibrosis (CF) is one of the most common autosomal-recessive inherited diseases. The primary genetic defect in CF is aligned CFTR gene mutation which encodes a membrane protein functioning as cAMP-depended chloride channel. Classic phenotypical manifestations of CF include chronic obstructive pulmonary disease with bronchiectasis, persisting infection (St. aureus, Ps. aeruginosa, B. cepacia) and aberrant inflammatory response, as well as exocrine pancreatic insufficiency with malabsorption, hypotrophy and growth retardation. CFTR deficiency is also accompanied by β-cell pancreatic dysfunction, causing glucose metabolism disturbances and CF-related diabetes. The aim of the study was the comparison of inflammatory markers dynamics in patients with normal and disturbed glucose metabolism during pulmonary exacerbation treatment. The study included 10 patients with impaired glucose tolerance (Group 1) and 24 patients with normal carbohydrate metabolism (Group 2). Patients of the two groups did not significantly differ in demographic characteristics, pulmonary function test and body mass index parameters, as well as in the number of F508del mutation carriers and in the number of those who were infected with Ps. aeruginosa and B. cepacia complex. Blood sampling was performed twice: before and after a routine course of antibiotic therapy. Plasma levels of biomarkers including the antibodies to single- and double-stranded DNA (ss-DNA-IgG, ds-DNA-IgG, respectively), the hormones (dehydroepiandrosterone (DHEA) and DHEA sulfate), C-reactive protein (CRP), Mn-dependent superoxide dismutase (Mn-SOD), and the cytokines (tumor necrosis factor-α (TNFα), interferon-γ (IFNγ), IFNα, tissue growth factor-β1 (TGF-β1), interleukin-4 (IL-4), IL-6, IL-10, IL-17A) were assessed using commercial immunoassay kits. Our study shows that antibiotic treatment did not have a sufficient influence on levels of inflammatory markers in patients with disturbances of glucose metabolism while patients with normal glucose tolerance demonstrated a significant reduction in inflammatory marker values after the therapy. The data may suggest both impaired effectivity of antibiotic treatment and aberrant inflammatory response in patients with glucose intolerance.

Seminological, Hormonal and Ultrasonographic Features of Male Factor Infertility Due to Genetic Causes: Results from a Large Monocentric Retrospective Study.

Objectives: Evaluate the prevalence of genetic factors in a large population of infertile subjects and define the seminological, hormonal, and ultrasonographic features for each alteration. Methods: This single-center retrospective study included male partners of infertile couples undergoing genetic investigations due to oligozoospermia or azoospermia evaluated from January 2012 to January 2022. The genetic investigations consist of karyotype, CFTR gene mutations plus variant of the IVS8-5T polymorphic trait, Y chromosome microdeletion, and Next Generation Sequencing panel to analyze genes implicated in congenital hypogonadotropic hypogonadism (CHH). Results: Overall, 15.4% (72/466) of patients received a diagnosis of genetic cause of infertility. Specifically, 23 patients (31.9%) harbor mutations in the CFTR gene, 22 (30.6%) have a 47, XXY karyotype, 14 (19.4%) patients show a Y chromosome microdeletion, 7 (9.7%) have structural chromosomal anomalies, and 6 (8.3%) have CHH. Overall, 80.6% of patients were azoospermic and 19.4% oligozoospermic (sperm concentration 3.5 ± 3.8 million/mL). Almost all patients presented hormonal alterations related to the specific genotype, while the main ultrasound alterations were testicular hypoplasia, calcifications/microcalcifications, and enlarged/hyperechoic epididymis. Conclusions: The prevalence of genetic abnormalities in males of infertile couples was 15.4% in our Center. CFTR gene disease-causing variants resulted in more frequent, with various clinical features, highlighting the complexity and heterogeneity of the presentation. Other investigations are needed to understand if conditions like ring chromosomes and other translocations are related to infertility or are incidental factors.

MRNA-specific readthrough of nonsense codons by antisense oligonucleotides (R-ASOs).

Nonsense mutations account for >10% of human genetic disorders, including cystic fibrosis, Alagille syndrome, and Duchenne muscular dystrophy. A nonsense mutation results in the expression of a truncated protein, and therapeutic strategies aim to restore full-length protein expression. Most strategies under development, including small-molecule aminoglycosides, suppressor tRNAs, or the targeted degradation of termination factors, lack mRNA target selectivity and may poorly differentiate between nonsense and normal stop codons, resulting in off-target translation errors. Here, we demonstrate that antisense oligonucleotides can stimulate readthrough of disease-causing nonsense codons, resulting in high yields of full-length protein in mammalian cellular lysate. Readthrough efficiency depends on the sequence context near the stop codon and on the precise targeting position of an oligonucleotide, whose interaction with mRNA inhibits peptide release to promote readthrough. Readthrough-inducing antisense oligonucleotides (R-ASOs) enhance the potency of non-specific readthrough agents, including aminoglycoside G418 and suppressor tRNA, enabling a path toward target-specific readthrough of nonsense mutations in CFTR, JAG1, DMD, BRCA1 and other mutant genes. Finally, through systematic chemical engineering, we identify heavily modified fully functional R-ASO variants, enabling future therapeutic development.

Prevalence of cancer and alcohol use in patients with exocrine pancreatic insufficiency compared to patients with cystic fibrosis.

680 Background: Cystic fibrosis (CF), the most prevalent genetic disorder among persons of European decent, is an autosomal recessive disorder due to CFTR gene mutations which lead to abnormally viscid exocrine secretions of the pancreas and other exocrine glands of the body. Exocrine pancreatic insufficiency (EPI) is a condition seen in ~85% of CF patients, in which the pancreas is unable to secrete adequate amounts of digestive enzymes. Although most patients with CF develop EPI, not all cases of EPI are caused by CF. Other risk factors for EPI include acute or chronic pancreatitis which may be triggered by alcohol, among other etiologies. Some studies suggest alcohol use as a possible independent risk factor for development of various cancers. Given these associations, we sought to characterize the prevalence of both alcohol use and cancer in patients with EPI vs patients with CF. Methods: A retrospective observational study was performed using electronic health records in Ochsner System, Louisiana, over a 3 year period: January 2017 to January 2020. Two cohorts were reviewed: patients with EPI excluding CF (n=596) and patients with CF (n=81). Results: While there was no significant difference in the prevalence of cancer at start vs end of the 3 year observation period in the CF cohort (4.1% at start, 7.2% at end), the prevalence of cancer was significantly greater among patients in the EPI cohort, both at start and end of the 3 year period: 15.95% at start, 43.9% at end (p <0.05). Also, while there was no significant change in alcohol use over the 3 year period for the CF cohort, the prevalence of alcohol use was significantly lower in CF cohort (0.45% at start, 2.2% at end) compared to EPI cohort which showed significant increase in alcohol use over the observation period: 7.7% at start vs 16% at end (p <0.05). Conclusions: There was a significantly higher prevalence of cancer in the EPI cohort compared to the CF cohort; while this may be due to higher prevalence of pancreatic cancer associated with EPI compared to CF, it does not explain the entirety of this observation. Not only was there a significantly higher prevalence of alcohol use in EPI cohort compared to CF cohort, but over the 3 year observation there was a 2-fold increase in prevalence of alcohol use within patients who already had a diagnosis of EPI. Within the EPI cohort, the observed increase in cancer prevalence and the increase in alcohol warrant further investigation into which factors unique to EPI patients without CF may modulate these social and health risk indices.

Type II Abernethy malformation with cystic fibrosis in a 12-year-old girl: A case report

BACKGROUND Abernethy malformation, also known as congenital extrahepatic portosystemic shunt, is an uncommon malformation resulting from aberrant development of the portal venous system. Cystic fibrosis (CF) is an autosomal recessive genetic disease caused by mutations in the CFTR gene. It mainly affects the exocrine glands of the respiratory, digestive and reproductive systems. It is considered extremely rare in the Asian population. We present a clinical case involving a pediatric patient of Asian descent who was diagnosed with Abernethy malformation and CF. CASE SUMMARY A 12-year-old girl presented with a medical history of recurring respiratory infections and hemoptysis, and chest computed tomography (CT) showed bronchiectasis. Whole exome sequencing was performed for the patient, yielding findings that revealed a compound heterozygous variant of the CFTR gene: c.233_c.234insT/p.Trp79fsTer3 (maternal origin); c.2909G>A/p.Gly970Asp (paternal origin). CF was diagnosed. The physician’s attention was drawn to the presence of splenomegaly during disease progression. Abdominal enhanced CT revealed splenomegaly, compression of the left kidney, and multiple tortuous dilated vascular shadows were seen at the splenic hilum, which flowed back into the left renal vein and portal vein, suggesting Abernethy malformation type II. Intraoperatively, the abnormal blood flow was seen to merge into the inferior vena cava through the left renal vein without hepatic processing, and the pathology of liver biopsy showed hypoplastic, dilated or absent portal vein branches, both of which supported the diagnosis of Abernethy malformation type II. This represents the initial documented instance of Abernethy malformation accompanied by a CFTR gene mutation in the existing body of literature. CONCLUSION Coexisting Abernethy malformation and CF are rare. Detailed medical history information, abdominal enhanced CT, venography and genetic testing contribute to diagnosis as well as differential diagnosis.

Insights Into Cystic Fibrosis Gene Mutation Frequency, Clinical Findings, and Complications Among Pakistani Patients.

Background Cystic fibrosis (CF) is a genetic disorder with diverse symptoms. Understanding its genetic basis and prevalence is crucial for effective management and treatment. Objective The study aimed to provide comprehensive insights into the frequency of CF gene mutations, clinical presentations, and complications among the Pakistani population. Methodology A cohort comprising 892 patients, ranging in age from 18 to more than 40 years, was selected on the basis of clinical and genetic criteria for the diagnosis of CF. Polymerase chain reaction (PCR) was used to look for 34 variants in the CFTR gene in blood samples. Statistical analysis, which included figuring out the number of mutations, the average age of diagnosis, and the genetic diversity of the samples, was performed to analyze the percentage of patients with specific mutations, offering insights into the genetic diversity. Results In our comprehensive analysis of 892 patient samples, 77.47% (n=691) displayed consanguinity, indicating a family history. The prevailing symptoms included chronic cough (88.67%; n=791), recurrent respiratory infections (76.68%; n=684), and fatigue (73.76%; n=658). The major complications comprised pulmonary infections (22%; n=197), cystic fibrosis-related diabetes (21%; n=187), and malabsorption (20%: n=178). A paired t-test revealed a mean difference of 5.750 with a standard deviation of 9.147, a 95% confidence interval from -0.061 to 11.561, a t-value of 2.178 with 11 degrees of freedom, and a two-tailed p-value of 0.052, suggesting a potential trend towards significance. Nevertheless, the asymptotic significance values of 1.000 and 0.998 for both groups indicate no significant difference. Furthermore, the study identified 12 cystic fibrosis gene mutations, with F508del and N1303K being the most prevalent. Conclusion This research revealed significant consanguinity, confirmed typical CFsymptoms, and identified common complicationsand prevalent CFTR gene mutations (with F508del and N1303K being the most common), providing insights for genetic guidance and treatment in the Pakistani community.

Role of unknown significance (VUS) and non-disease-causing (NDC) CFTR gene mutations in the pathogenesis of acute pancreatitis

Role of unknown significance (VUS) and non-disease-causing (NDC) CFTR gene mutations in the pathogenesis of acute pancreatitis

Clinical and Genetic Description of Hereditary Chronic Pancreatitis in Pakistani Children.

The purpose of this study was to identify the spectrum and frequency of pathogenic variants as well as the clinical and genetic insight of hereditary chronic pancreatitis in Pakistani children. The deoxyribonucleic acid of affected probands of 44 unrelated Pakistani families, having hereditary chronic pancreatitis-affected children, were subjected to massive parallel sequencing for candidate reported genes (SPINK1, PRSS1, CFTR, CPA1, CTRC, CBS, AGL, PHKB, and LPL). Data were analyzed using different bioinformatics tools for the variants and in-silico analysis. All the identified variants were validated by direct sequencing of the targeted exons in the probands and their parents. There were 50 patients included in this study with confirmed hereditary chronic pancreatitis. Nine known mutations in SPINK1, PRSS1, CFTR, CTRC, CBS, and AGL genes, and 10 novel variants in LPL, CFTR, CTR, and PHKB genes were identified. The identified variants were found in heterozygous, compound heterozygous, and trans-heterozygous forms, with rare allele frequency in the normal population. The novel variants were [c.378C>T(p.Lys126Asn) and c.719G>A(p.Arg240Gln) in CTRC, c.586-3C>A and c.763A>G(p.Arg255Gly) in CPA1, c.1160_1161insT(p.Lys387Asnfs*26), c.784C>T(p.Gln262*), c.1139+1G>A, c.175G>A(p.Gly59Arg) in LPL, c.388C>G(p.leu130val) in CFTR, and c.2327G>A(p.Arg776His in PHKB)]. The phenotypic characteristics were variable and correlated with the relevant variant. The genetic composition plays a significant role in the predisposition of hereditary chronic pancreatitis. The clinical presentation varies with the genetic determinant involved. This information would help in building up a diagnostic algorithm for our population that can be used for genetic screening services in affected cohorts.

Pathophysiological features of chronic IgE-mediated rhinosinusitis of bacterial etiology

Chronic rhinosinusitis (CRS) is a disease caused by inflammation of the paranasal sinuses and its mucous membrane lasting for more than 4 weeks continuously. The aim of our study was to examine the main pathophysiological features of chronic IgE-mediated rhinosinusitis of bacterial etiology according to publications in the Russian Federation and in the world. A search was made through English- and Russian-language literature sources using the following databases: PubMed, MedLine, Web of Science, Russian Science Citation Index, Springer, Scopus, Scientific Research, Google Scholar, Crossref, eLibrary. The epidemiological features of CRS in the Russian Federation, bacterial pathogens and pathophysiological characteristics of CRS were analyzed. A 2-fold increase in the prevalence of CRS was registered over the past 20 years. Prevalence of the disease increases at longer age ranges. Chronic rhinosinusitis ranks first among all chronic diseases in the field of otorhinolaryngology. Allergic rhinitis, asthma, bronchiectasia, immunodeficiencies, cystic fibrosis, primary ciliary dyskinesia and autoimmune diseases are associated with CRS. The most common bacterial pathogens are S. aureus, Staphylococcus epidermidis and Propionibacterium acnes, Prevotella, Streptococcus and Veillonella, and some Gram-negative bacteria, e.g., Pseudomonas aeruginosa (P. aeruginosa), Proteus mirabilis and Klebsiella pneumoniae. Staphylococcus aureus (S. aureus) is involved in pathogenesis of nasal polyps. The colonizing bacteria may contribute to pathogenesis of CRS through the formation of biofilms. Alterations in the sino-nasal microbiome may also contribute to the development of CRS. An association of the CRS and CFTR gene mutations plays a significant role in the pathogenesis of chronic rhinosinusitis. An “immune barrier hypothesis” has been proposed as potential mechanism of CRS. Reduced expression of SPINK5, impaired STAT3 signaling, and T2R38 bitter taste receptor polymorphism have been identified in the pathogenesis of CRS. The T2R38 gene stimulates epithelial cells to produce nitrous oxide with a bactericidal effect, promotes mucociliary elimination of pathogens and prevention of upper respiratory tract infections, the polymorphism of this gene predisposes patients to gram-negative infectious diseases, and therefore is a risk factor for the development of CRS. In addition, antibody deficiency is the most common primary immunodeficiency associated with CRS.Hence, the pathogenesis of chronic IgE-mediated rhinosinusitis of bacterial etiology is associated with defects in innate immunity and mucociliary clearance, influence of the sinonasal microbiome, allergies, and genetic factors. A comprehensive assessment of these factors is necessary for the development of new preventive and therapeutic options for the correction of CRS.

The Most Common Mutations in the CFTR Gene in the Population of Bosnia and Herzegovina

Aims: Cystic fibrosis is an autosomal recessive multisystem disease caused by a mutation of the CFTR gene. To date, more than 1900 mutations of this gene are known. Studies have shown that the most common mutation is delF508. In Bosnia and Herzegovina, the prevalence of individual mutations in the general population has not been thoroughly studied, so this study aimed to determine the prevalence of the mutation concerning the countries of the region and the rest of the world.
 Study Design: Retrospective study.
 Place and Duration of Study: Thirty-nine subjects with suspected Cystic fibrosis were referred to the Center for Genetics of the Medical Faculty in Sarajevo between 2018-2020.
 Methodology: 29 common CFTR gene mutations were analysed with the ELUCIGENE CF29 v2 kit (Elucigene Diagnostics, UK) using four multiplex PCR.
 Results: The most common mutation in our study was the F508 deletion, present in 14 subjects (73.68%). R347P and G542X mutations were confirmed in two subjects in the heterozygous state in combination with delF508 (M) 5.26% of each of these mutations. 621+1G>T was found in a homozygous state in one subject, while in another, it was in a heterozygous state in combination with delF508(M) mutation, 10.52%. Mutation 2184 delA was found in one subject in the homozygous state with a total frequency of 5.26%.
 Conclusion: Subjects with cystic fibrosis in Bosnia and Herzegovina are most often carriers of the delF508 mutation. Considering the existence of many mutations and that it is difficult to test them all, targeting the most common mutations in a clinical environment might help in approving therapy, and increasing patients’ quality of life.

Clinical, paraclinical, and genetic profile of patients with cystic fibrosis from Colombian Caribbean

BackgroundCystic fibrosis (CF) is a serious autosomal recessive disorder. Early diagnosis, comorbidity prevention, and control are cornerstones for a quality life and for improving life expectancy. In Colombian Caribbean, where there is a genetically admixed population, CF is an orphan disease affecting children and adults, and it remains a challenging issue to be addressed carefully. This work describes the genetic, clinical, and paraclinical profiles of CF patients from Cartagena de Indias, Colombia. MethodsThirty-six patients were included in the study. The subjects were identified and evaluated through the Regional Program for CF patients. CFTR gene mutations, anthropometric parameters, microbiological infections, and pulmonary function were analyzed. Data on demographic parameters, pharmacological treatments, and comorbidities were reported. Frequency and percentages were established for the categorical variables and mean or median for the quantitative variables. In addition, comparisons were made by sex. ResultsThe average age of the patients was 11.9 ± 5.3 years and the median age at diagnosis was 14 months. 55.5% were women and 44.5% were men. The mean values for weight, height, and body mass index were 35 ± 17.6 kg, 139.9 ± 28 cm, and 16.5 ± 2.9 kg/m2, respectively. The clinical manifestations that occurred more frequently were steatorrhea (65.4%) and recurrent pneumonia (46.2%). Chronic airway infection with Pseudomonas aeruginosa was identified in 71.4% of the cases and the p.F508del mutation was found in 47.2% of the subjects. ConclusionThe current profile of CF patients from the Colombian Caribbean showed some concerning features, such as nutritional status; however, progress in early diagnosis and clinical follow-up could contribute to improve the general conditions of patients. It is necessary to continue efforts to increase the life expectancy and quality of life of the patients.

Investigating the Inhibition of FTSJ1, a Tryptophan tRNA-Specific 2'-O-Methyltransferase by NV TRIDs, as a Mechanism of Readthrough in Nonsense Mutated CFTR.

Cystic Fibrosis (CF) is an autosomal recessive genetic disease caused by mutations in the CFTR gene, coding for the CFTR chloride channel. About 10% of the CFTR gene mutations are "stop" mutations that generate a premature termination codon (PTC), thus synthesizing a truncated CFTR protein. A way to bypass PTC relies on ribosome readthrough, which is the ribosome's capacity to skip a PTC, thus generating a full-length protein. "TRIDs" are molecules exerting ribosome readthrough; for some, the mechanism of action is still under debate. We investigate a possible mechanism of action (MOA) by which our recently synthesized TRIDs, namely NV848, NV914, and NV930, could exert their readthrough activity by in silico analysis and in vitro studies. Our results suggest a likely inhibition of FTSJ1, a tryptophan tRNA-specific 2'-O-methyltransferase.

Fetal intestinal loop dilatation: Follow-up and outcome of a series of 133 consecutive cases (the DILDIG study).

To define the prognostic markers of fetal dilated bowel loops. National non-interventional study of 133 consecutive prenatal observations of dilated loops including ultrasound examinations, complementary laboratory tests, magnetic resonance imaging (MRI), outcomes, and postnatal diagnosis. One hundred twenty seven cases were classified according to outcome: Group 1, very severe (n=43), Group 2, children needing specific care (n=39), and Group 3, healthy children (n=45). Prenatal ultrasound scan suggested duodenal obstruction in 30 cases, small bowel obstruction in 81, colonic obstruction in 11, and diffuse dilatation in 5. Diameter of dilated loops did not significantly differ between the groups. A poor prognosis was significantly associated with duodenal obstruction, genetic anomalies (53% vs. 21.8%), including aneuploidies or CFTR gene mutations and abnormal amniotic fluid biochemistry (86.4% vs. 38.7%). A good prognosis was associated with regression of dilatation and normal MRI. In this study, postnatal outcomes for fetuses with intestinal dilatation were best predicted by assessing the level of obstruction with prenatal ultrasound and MRI, determining the presence of associated malformations, amniotic fluid biochemical and genetic testing, and monitoring for regression of bowel dilatation. These results should help inform future guidelines on the prenatal and neonatal management of congenital intestinal obstruction.

TGF-β1 Inhibition of ACE2 Mediated by miRNA Uncovers Novel Mechanism of SARS-CoV-2 Pathogenesis

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for COVID-19, utilizes receptor binding domain (RBD) of spike glycoprotein to interact with angiotensin (Ang)-converting enzyme 2 (ACE2). Altering ACE2 levels may affect entry of SARS-CoV-2 and recovery from COVID-19. Decreased cell surface density of ACE2 leads to increased local levels of Ang II and may contribute to mortality resulting from acute lung injury and fibrosis during COVID-19. Studies published early during the COVID-19 pandemic reported that people with cystic fibrosis (PwCF) had milder symptoms, compared to people without CF. This finding was attributed to elevated ACE2 levels and/or treatment with the high efficiency CFTR modulators. Subsequent studies did not confirm these findings reporting variable effects of CFTR gene mutations on ACE2 levels. Transforming growth factor (TGF)-β signaling is essential during SARS-CoV-2 infection and dominates the chronic immune response in severe COVID-19, leading to pulmonary fibrosis. TGF-β1 is a gene modifier associated with more severe lung disease in PwCF but its effects on the COVID-19 course in PwCF is unknown. To understand whether TGF-β1 affects ACE2 levels in the airway, we examined miRNAs and their gene targets affecting SARS-CoV-2 pathogenesis in response to TGF-β1. Small RNAseq and micro(mi)RNA profiling identified pathways uniquely affected by TGF-β1, including those associated with SARS-CoV-2 invasion, replication, and the host immune responses. TGF-β1 inhibited ACE2 expression by miR-136-3p and miR-369-5p mediated mechanism in CF and non-CF bronchial epithelial cells. ACE2 levels were higher in two bronchial epithelial cell models expressing the most common CF-causing mutation in CFTR gene F508del, compared to controls without the mutation. After TGF-β1 treatment, ACE2 protein levels were still higher in CF, compared to non-CF cells. TGF-β1 prevented the modulator-mediated rescue of F508del-CFTR function while the modulators did not prevent the TGF-β1 inhibition of ACE2 levels. Finally, TGF-β1 reduced the interaction between ACE2 and the recombinant spike RBD by lowering ACE2 levels and its binding to RBD. Our data demonstrate novel mechanism whereby TGF-β1 inhibition of ACE2 in CF and non-CF bronchial epithelial cells may modulate SARS-CoV-2 pathogenicity and COVID-19 severity. By reducing ACE2 levels, TGF-β1 may decrease entry of SARS-CoV-2 into the host cells while hindering the recovery from COVID-19 due to loss of the anti-inflammatory and regenerative effects of ACE2. The above outcomes may be modulated by other, miRNA-mediated effects exerted by TGF-β1 on the host immune responses, leading to a complex and yet incompletely understood circuitry.

Insight into clinical, laboratory, and GIT ultrasound diagnostic findings of cystic fibrosis in pediatrics

BackgroundCystic fibrosis (CF) is a multisystem disorder. Gastrointestinal tract (GIT) involvement presently requires medical attention, and this improves the survival rate of patients with CF. GIT imaging has an essential role in the early detection of GIT affection. This study aimed to quantify the abdominal symptoms and their relationship to clinical findings, abdominal ultrasound scoring system, and laboratory parameters, correlating GIT manifestation with ultrasound diagnostic findings.MethodsThis was a cross-sectional study that included 60 patients diagnosed with CF based on clinical manifestations and confirmed by a positive sweat chloride test ≥ 60 mmol/L and/or genetic analysis (CFTR gene mutation; a copy from each parent) in the CF clinic in the Children’s Hospital, in a period of 12 months.ResultsRecurrent abdominal pain (RAP) was the most common GIT manifestation, followed by abdominal distension and steatorrhea. Ultrasonography (US) showed that the most frequent findings were pancreatic lipomatosis in 16 patients (26.7%), the next common finding was heterogeneous coarse hepatic parenchyma in 14 patients (23.3%), while the least finding was the thickened bowel walls in 2 patients (3.3%). Abdominal US scoring revealed that the highest burden of GIT symptoms was clearly associated with pancreatic lipomatosis and liver steatosis with the highest score (6/7) (p = 0.048), while bowel wall thickness (BWT) had the lowest score (3/7) (Table 4).ConclusionThis study reveals that abdominal US is a non-invasive investigation that helps in the early detection of GIT involvement in CF. RAP is a common GIT manifestation and may reflect a major pathology. Moreover, a significant relationship was detected between RAP and pancreatic cystosis and lipomatosis. Therefore, the study also highlights the importance of US as a routine non-invasive follow-up tool for patients with CF and suggests close monitoring of patients with CF by abdominal US performed every 6 to 12 months.

Heterogeneity of phenotypic manifestations of cystic fibrosis in children and predictors of the disease severity

The aim of the study was to investigate the heterogeneity of phenotypic manifestations of cystic fibrosis (CF) in children depending on the CFTR gene mutation and to determine predictors of the disease severity for the personalization of treatment and prevention of complications. Materials and methods. Fifty-nine children with CF, aged 1 to 18 years (mean age was 12.0 (8.5; 15.0) years), were examined. All patients underwent general clinical, genetic, laboratory and microbiological examination. Instrumental methods of examination included spirometry, chest X-ray and computed tomography, ultrasound densitometry. According to the functional effects of CFTR mutations, the patients were divided into two groups. The group with “severe” genotypes (n = 40) included patients with two class I and/or II mutations, and the group with “mild” genotypes (n = 10) included patients with at least one class IV or V mutation. Mutations were not identified in 9 patients. Results. Analysis of the spectrum of genetic variants in the CFTR gene showed that 10 patients (20.0 %) were identified with the “mild” genotype, and 40 patients (80.0 %) with the “severe” genotype. The most common mutation was F508del predominantly in the compound heterozygous state (42.4 %). It was found that patients with the “mild” genotype were characterized by a more favorable course of the disease than patients with the “severe” genotype. No statistically significant phenotypic features of the CF course in children depending on the F508del mutation status (F508del/F508del or F508del/nonF508del) were found, except for earlier formation of pulmonary hypertension in patients with the homozygous condition (47.1% vs 16.0 %, P < 0.05). Conclusions. Examination of the relationship between CFTR genotype and phenotype has revealed associations between CFTR mutations and lesion severity of both the digestive and bronchopulmonary systems. Identification of disease severity predictors can provide a more accurate prediction of the disease course, that will determine the patient management and prevent the development of complications.

Heterogeneous spectrum of CFTR gene mutations in Chinese patients with CAVD and the dilemma of genetic blocking strategy.

The genetic heterogeneity of CFTR gene mutations in Chinese patients with congenital absence of the vas deferens (CAVD) differs from the hotspot mutation pattern in Caucasians. This paper reviews and suggests a more suitable screening strategy for the Chinese considering the dilemma of CFTR genetic blocking. Congenital absence of the vas deferens (CAVD) is a major cause of obstructive azoospermia and male infertility, with CFTR gene mutation as the main pathogenesis. Other genes such as ADGRG2, SLC9A3, and PANK2 have been discovered and proven to be associated with CAVD in recent studies. Multiple CFTR hotspot mutations have been found in Caucasians in several foreign countries, and relevant genetic counseling and preimplantation genetic diagnosis (PGD) have been conducted for decades. However, when we examined research on Chinese CAVD, we discovered that CFTR mutations show heterogeneity in the Chinese Han population, and there is currently no well-established screening strategy. Therefore, we have reviewed the literature, combining domestic and international research as well as our own, aiming to review research progress on the CFTR gene in China and discuss the appropriate scope for CFTR gene detection, the detection efficiency of other CAVD-related genes, and the screening strategy applicable to the Chinese Han population. This study provides more valuable information for genetic counseling and a theoretical basis for PGD and treatment for couples with CAVD when seeking reproductive assistance.

Generation of two induced pluripotent stem cell lines (RCMGi005-A/B) from human skin fibroblasts of a cystic fibrosis patient with homozygous F508del mutation in CFTR gene

Induced pluripotent stem cells (iPSCs) was successfully generated from skin fibroblast obtained from patient with cystic fibrosis by using non-integrating, viral CytoTune™-iPS 2.0 Sendai Reprogramming Kit, which contain three vectors preparation: polycistronic Klf4–Oct3/4–Sox2, cMyc, and Klf4. Created iPSC lines showed a normal karyotype, expressed pluripotency markers and demonstrated the potential to differentiate into three germ layers in spontaneous differentiation assay.

Generation of induced pluripotent stem cell line (RCMGi008-A) from human skin fibroblasts of a cystic fibrosis patient with compound heterozygous F508del/CFTRdele2.3 mutations in CFTR gene

Skin fibroblasts obtained from a 20-year-old woman with clinically manifested and genetically proven (F508del/CFTRdele2.3) cystic fibrosis were successfully transformed into induced pluripotent stem cells (iPSCs) by using Sendai virus-based reprogramming vectors including the four Yamanaka factors, OCT3/4, SOX2, KLF4, and c-MYC. The iPSCs showed a normal karyotype, expressed pluripotency markers and exhibited the potential to differentiate into three germ layers in spontaneous differentiation assay. This iPSC line may be used for development of a personalized treatment including genome editing, disease modelling, cell differentiation and organoid formation, pharmacological investigations and drug screening.