Congenital Pulmonary Airway Malformations With a Reconsideration and Current Perspective on the Stocker Classification.

Congenital cystic pulmonary lesions (CCPLs) are represented by the following entities: congenital pulmonary airway malformation (CPAM), formerly congenital cystic adenomatoid malformation, extra- and intralobar sequestration (EIS), congenital lobar emphysema (overexpansion), and bronchogenic cyst. The developmental model of CPAM histogenesis by Stocker proposed perturbations designated as CPAM type 0 to type 4 without known or specific pathogenetic mechanisms along the airway from the bronchus to the alveolus. This review highlights mutational events either at the somatic level in KRAS (CPAM types 1 and possibly 3) or germline variants in congenital acinar dysplasia, formerly CPAM type 0, and pleuropulmonary blastoma (PPB), type I, formerly CPAM type 4. The potential for overt malignant progression exists in the case of PPB type I and CPAM type 1 in some cases to well-differentiated mucinous adenocarcinoma. On the other hand, CPAM type 2 is an acquired lesion resulting from interruption in lung development secondary to bronchial atresia. The latter is also regarded as the etiology of EIS whose pathologic features are similar, if not identical, to CPAM type 2. These observations have provided important insights into the pathogenetic mechanisms in the development of the CPAMs since the Stocker classification.

Congenital lung malformations: Dysregulated lung developmental processes and altered signaling pathways.

Congenital lung malformations comprise a diverse group of anomalies including congenital pulmonary airway malformation (CPAM, previously known as congenital cystic adenomatoid malformation or CCAM), bronchopulmonary sequestration (BPS), congenital lobar emphysema (CLE), bronchogenic cysts, and hybrid lesions. Little is known about the signaling pathways that underlie the pathophysiology of these lesions and the processes that may promote their malignant transformation. In the last decade, the use of transgenic/knockout animal models and the implementation of next generation sequencing on surgical lung specimens have increased our knowledge on the pathophysiology of these lesions. Herein, we provide an overview of normal lung development in humans and rodents, and we discuss the current state of knowledge on the pathophysiology and molecular pathways that are altered in each congenital lung malformation.

SARS-CoV-2 Exposed Mesenchymal Stromal Cell from Congenital Pulmonary Airway Malformations: Transcriptomic Analysis and the Expression of Immunomodulatory Genes.

The inflammatory response plays a central role in the complications of congenital pulmonary airway malformations (CPAM) and severe coronavirus disease 2019 (COVID-19). The aim of this study was to evaluate the transcriptional changes induced by SARS-CoV-2 exposure in pediatric MSCs derived from pediatric lung (MSCs-lung) and CPAM tissues (MSCs-CPAM) in order to elucidate potential pathways involved in SARS-CoV-2 infection in a condition of exacerbated inflammatory response. MSCs-lung and MSCs-CPAM do not express angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TRMPSS2). SARS-CoV-2 appears to be unable to replicate in MSCs-CPAM and MSCs-lung. MSCs-lung and MSCs-CPAM maintained the expression of stemness markers MSCs-lung show an inflammatory response (IL6, IL1B, CXCL8, and CXCL10), and the activation of Notch3 non-canonical pathway; this route appears silent in MSCs-CPAM, and cytokine genes expression is reduced. Decreased value of p21 in MSCs-lung suggested no cell cycle block, and cells did not undergo apoptosis. MSCs-lung appears to increase genes associated with immunomodulatory function but could contribute to inflammation, while MSCs-CPAM keeps stable or reduce the immunomodulatory receptors expression, but they also reduce their cytokines expression. These data indicated that, independently from their perilesional or cystic origin, the MSCs populations already present in a patient affected with CPAM are not permissive for SARS-CoV-2 entry, and they will not spread the disease in case of infection. Moreover, these MSCs will not undergo apoptosis when they come in contact with SARS-CoV-2; on the contrary, they maintain their staminality profile.

Effect of TGF-ß1 on eosinophils to induce cysteinyl leukotriene E4 production in aspirin-exacerbated respiratory disease.

Cysteinyl leukotriene (cysLT) overproduction and eosinophil activation are hallmarks of aspirin-exacerbated respiratory disease (AERD). However, pathogenic mechanisms of AERD remain to be clarified. Here, we aimed to find the significance of transforming growth factor beta 1 (TGF-ß1) in association with cysteinyl leukotriene E4 (LTE4) production, leading to eosinophil degranulation. To evaluate levels of serum TGF-ß1, first cohort enrolled AERD (n = 336), ATA (n = 442) patients and healthy control subjects (HCs, n = 253). In addition, second cohort recruited AERD (n = 34) and ATA (n = 25) patients to investigate a relation between levels of serum TGF-ß1 and urinary LTE4. The function of TGF-ß1 in LTE4 production was further demonstrated by ex vivo (human peripheral eosinophils) or in vivo (BALB/c mice) experiment. As a result, the levels of serum TGF-ß1 were significantly higher in AERD patients than in ATA patients or HCs (P = .001; respectively). Moreover, levels of serum TGF-ß1 and urinary LTE4 had a positive correlation (r = 0.273, P = .037). In the presence of TGF-ß1, leukotriene C4 synthase (LTC4S) expression was enhanced in peripheral eosinophils to produce LTE4, which sequentially induced eosinophil degranulation via the p38 pathway. When mice were treated with TGF-ß1, significantly induced eosinophilia with increased LTE4 production in the lung tissues were noted. These findings suggest that higher levels of TGF-ß1 in AERD patients may contribute to LTE4 production via enhancing LTC4S expression which induces eosinophil degranulation, accelerating airway inflammation.

Pulmonary Manifestations of Genetic Disorders in Children.

Congenital bronchopulmonary malformations are relatively common and arise during various periods of morphogenesis. Although some are isolated or sporadic occurrences, others may result from single gene mutations or cytogenetic imbalances. Single gene mutations have been identified, which are etiologically related to primary pulmonary hypoplasia, lung segmentation defects as well as pulmonary vascular and lymphatic lesions. Functional defects in cystic fibrosis, primary ciliary dyskinesias, alpha-1-antitrypsin deficiency, and surfactant proteins caused by gene mutations may result in progressive pulmonary disease. This article provides an overview of pediatric pulmonary disease from a genetic perspective.

The oculoauriculofrontonasal syndrome: Further clinical characterization and additional evidence suggesting a nontraditional mode of inheritance.

The oculoauriculofrontonasal syndrome (OAFNS) is a rare disorder characterized by the association of frontonasal dysplasia (widely spaced eyes, facial cleft, and nose abnormalities) and oculo-auriculo-vertebral spectrum (OAVS)-associated features, such as preauricular ear tags, ear dysplasia, mandibular asymmetry, epibulbar dermoids, eyelid coloboma, and costovertebral anomalies. The etiology is unknown so far. This work aimed to identify molecular bases for the OAFNS. Among a cohort of 130 patients with frontonasal dysplasia, accurate phenotyping identified 18 individuals with OAFNS. We describe their clinical spectrum, including the report of new features (micro/anophtalmia, cataract, thyroid agenesis, polymicrogyria, olfactory bulb hypoplasia, and mandibular cleft), and emphasize the high frequency of nasal polyps in OAFNS (56%). We report the negative results of ALX1, ALX3, and ALX4 genes sequencing and next-generation sequencing strategy performed on blood-derived DNA from respectively, four and four individuals. Exome sequencing was performed in four individuals, genome sequencing in one patient with negative exome sequencing result. Based on the data from this series and the literature, diverse hypotheses can be raised regarding the etiology of OAFNS: mosaic mutation, epigenetic anomaly, oligogenism, or nongenetic cause. In conclusion, this series represents further clinical delineation work of the rare OAFNS, and paves the way toward the identification of the causing mechanism.

Novel Molecular and Phenotypic Insights into Congenital Lung Malformations.

RATIONALE: Disruption of normal pulmonary development is a leading cause of morbidity and mortality in infants. Congenital lung malformations are a unique model to study the molecular pathogenesis of isolated structural birth defects, as they are often surgically resected. OBJECTIVES: To provide insight into the molecular pathogenesis of congenital lung malformations through analysis of cell-type and gene expression changes in these lesions. METHODS: Clinical data, and lung tissue for DNA, RNA, and histology, were obtained from 58 infants undergoing surgical resection of a congenital lung lesion. Transcriptome-wide gene expression analysis was performed on paired affected and unaffected samples from a subset of infants (n = 14). A three-dimensional organoid culture model was used to assess isolated congenital lung malformation epithelium (n = 3). MEASUREMENTS AND MAIN RESULTS: Congenital lung lesions express higher levels of airway epithelial related genes, and dysregulated expression of genes related to the Ras and PI3K-AKT-mTOR (phosphatidylinositol 3-kinase-AKT-mammalian target of rapamycin) signaling pathways. Immunofluorescence confirmed differentiated airway epithelial cell types throughout all major subtypes of congenital lung lesions, and three-dimensional cell culture demonstrated a cell-autonomous defect in the epithelium of these lesions. CONCLUSIONS: This study provides the first comprehensive analysis of the congenital lung malformation transcriptome and suggests that disruptions in Ras or PI3K-AKT-mTOR signaling may contribute to the pathology through an epithelial cell-autonomous defect.

Association of Single Nucleotide Polymorphisms of PADI4 and HLA-DRB1 Alleles with Susceptibility to Rheumatoid Arthritis-Related Lung Diseases.

OBJECTIVE: Lung diseases (LD) are common extra-articular manifestations in rheumatoid arthritis (RA). However, little is known about factors associated with susceptibility to rheumatoid arthritis-related lung diseases (RA-LD). The aim of the present study was to investigate whether the single nucleotide polymorphisms (SNPs) of PADI4 and HLA-DRB1 alleles were associated with RA-LD. METHODS: Blood samples and clinical data were collected from 116 consecutive RA patients who satisfied the 1987 American College of Rheumatology classification criteria. RA-LD was diagnosed using high-resolution computed tomography of the chest. All patients were genotyped for SNPs of PADI4 and HLA-DRB1 alleles and analyzed for full amino acid sequence of the HLA protein corresponding to a 4-digit HLA typing. Data were analyzed by independent t test (or Mann-Whitney test) for continuous variables, Chi-square test (or Fisher's exact test) and trend test for categorical variables, and logistic regression analysis. RESULTS: Ninety-four (81.0 %) RA patients had LD, of which eight (6.9 %) had interstitial lung disease (ILD) and 92 (79.3 %) had airway abnormalities in which 64 (55.2 %) showed bronchiectasis and 47 (40.5 %) revealed bronchial wall thickening. The recessive genotype of padi4_92 was susceptible to airway abnormalities (OR = 2.22, 95 % CI = 1.05-4.49, p = 0.034). Tryptophan at position 9 of HLA-DRB1 sequence was associated with the susceptibility to RA-ILD (OR = 22.89, 95 % CI = 1.20-432.56, p = 0.037). CONCLUSION: PADI4 polymorphisms and HLA-DRB1 alleles could attribute differently to the development of airway abnormalities and ILD, respectively, in RA.

Respiratory system involvement in Costello syndrome.

Costello syndrome (CS) is a multisystem disorder caused by heterozygous germline mutations in the HRAS proto-oncogene. Respiratory system complications have been reported in individuals with CS, but a comprehensive description of the full spectrum and incidence of respiratory symptoms in these patients is not available. Here, we report the clinical course of four CS patients with respiratory complications as a major cause of morbidity. Review of the literature identified 56 CS patients with descriptions of their neonatal course and 17 patients in childhood/adulthood. We found that in the neonatal period, respiratory complications are seen in approximately 78% of patients with transient respiratory distress reported in 45% of neonates. Other more specific respiratory diagnoses were reported in 62% of patients, the majority of which comprised disorders of the upper and lower respiratory tract. Symptoms of upper airway obstruction were reported in CS neonates but were more commonly diagnosed in childhood/adulthood (71%). Analysis of HRAS mutations and their respiratory phenotype revealed that the common p.Gly12Ser mutation is more often associated with transient respiratory distress and other respiratory diagnoses. Respiratory failure and dependence on mechanical ventilation occurs almost exclusively with rare mutations. In cases of prenatally diagnosed CS, the high incidence of respiratory complications in the neonatal period should prompt anticipatory guidance and development of a postnatal management plan. This may be important in cases involving rarer mutations. Furthermore, the high frequency of airway obstruction in CS patients suggests that otorhinolaryngological evaluation and sleep studies should be considered. © 2016 Wiley Periodicals, Inc.

Oculoauriculofrontonasal syndrome: case series revealing new bony nasal anomalies in an old syndrome.

Frontonasal Dysplasia (FND) and Oculo-auriculo-vertebral spectrum (OAVS) are two well-recognized clinical entities. With features of both FND and OAVS, the term oculoauriculofrontonasal syndrome (OAFNS) was coined in 1981. The OAFNS phenotype combines elements of abnormal morphogenesis of the frontonasal and maxillary process (derived from forebrain neural crest) with abnormal development of the first and second branchial arches (derived from hindbrain neural crest). We present a case series of 33 children with OAFNS ascertained from a comprehensive review of the literature and report an additional retrospective series of eight patients displaying features consistent with OAFNS. Notably, in a subset of our cases, we have observed abnormalities in nasal ossification and bony structures of the maxilla that have not previously described in OAFNS and are not seen in either FND or OAVS. We present the phenotype and novel naso-maxillary findings and explore potential etiologic and developmental pathways for OAFNS. We highlight the differences in phenotypic characteristics of OAFNS compared to OAVS and FND. These observations support the classification of OAFNS as a discrete syndrome. Further phenotypic refinements of OAFNS are needed to understand pathogenesis of this syndrome and the newly described nasal malformation may help identify the etiology.

[Congenital lung malformations: natural history and pathophysiological mechanisms]. / Malformations pulmonaires congénitales: histoire naturelle et hypothèses pathogéniques.

INTRODUCTION: Congenital lung lesions comprise a broad spectrum of various malformations including congenital cystic adenomatoid malformation (CCAM), bronchopulmonary sequestration (BPS), congenital lobar emphysema, bronchial atresia and bronchogenic cyst. This review aims at the description of their natural history, and of the underlying pathophysiological mechanisms. STATE OF THE ART: Congenital lung lesions are frequently diagnosed antenatally and many remain asymptomatic after birth. In the absence of antenatal identification, they are usually revealed by the occurrence of infection. In some cases, spontaneous resolution of the malformation can occur. Different pathogenic hypotheses are discussed for the origin of these abnormalities, and common processes appear likely to all of these malformations. Factors involved in the process of branching seem to play a particularly important role. PERSPECTIVES: Prospective follow-up of operated and unoperated children would complete our knowledge about the natural history of these lesions. The contribution of experimental models has led to advances in the understanding of pathogenic mechanisms. Further studies are needed to identify the factors initiating the malformative process.

Head and neck manifestations of 22q11.2 deletion syndromes.

The allelic loss of 22q11.2 results in various developmental failures of pharyngeal pouch derivatives ("22q11.2 deletion syndromes", 22q.11DS), consequently affecting the anatomy and physiology of head and neck (H&N) organs. The objective of this paper was to describe those manifestations. Two 22q11.2DS patients with H&N manifestations were studied along with a comprehensive review of the English literature, from 1975 to 2010 regarding the associated H&N malformations among 22q11.2DS. A 24-year-old mentally disabled 22q11.2DS male presented with right hemithyroid enlargement, causing significant compressive signs. Sonography revealed a homogeneous 8 × 3 cm lesion, replacing almost the entire thyroid lobe. Fine needle aspiration revealed colloid material and abundant eosinophils. The hemithyroidectomy specimen confirmed follicular adenoma. A 19-year-old mentally disabled 22q11.2DS female underwent CT-angiography due to an upper GI bleeding. The study revealed a vascular malformation in the infratemporal fossa. Reviewing the reported data regarding 22q11.2DS-associated H&N malformations revealed abnormalities and malfunctions of the thyroid gland, parathyroid glands, thymus agenesis, cleft palate, carotid artery aberrations, malformations of the larynx and trachea and esophageal dysmotility. 22q11.DS patients may present with H&N anatomical abnormalities, along with hormonal dysfunctions, which require special awareness once treatment is offered, especially when concerning anesthetic and surgical aspects. In addition, hSNF5/INI1, a tumor suppressor gene, detected at location 22q11.2 was described to be "knocked out" in some patients. This may be associated with H&N tumors reported in these patients.

Abnormal respiratory cilia in non-syndromic Leber congenital amaurosis with CEP290 mutations.

BACKGROUND: Leber congenital amaurosis (LCA) is the earliest and most severe inherited retinal degeneration. Isolated forms of LCA frequently result from mutation of the CEP290 gene which is expressed in various ciliated tissues. METHODS: Seven LCA patients with CEP290 mutations were investigated to study otorhinolaryngologic phenotype and respiratory cilia. Nasal biopsies and brushing were performed to study cilia ultrastructure using transmission electron microscopy and ciliary beating using high-speed videomicroscopy, respectively. CEP290 expression in normal nasal epithelium was studied using real-time RT-PCR. RESULTS: When electron microscopy was feasible (5/7), high levels of respiratory cilia defects were detected. The main defects concerned dynein arms, central complex and/or peripheral microtubules. All patients had a rarefaction of ciliated cells and a variable proportion of short cilia. Frequent but moderate and heterogeneous clinical and ciliary beating abnormalities were found. CEP290 was highly expressed in the neural retina and nasal epithelial cells compared with other tissues. DISCUSSION: These data provide the first clear demonstration of respiratory cilia ultrastructural defects in LCA patients with CEP290 mutations. The frequency of these findings in LCA patients along with the high expression of CEP290 in nasal epithelium suggest that CEP290 has an important role in the proper development of both the respiratory ciliary structures and the connecting cilia of photoreceptors. The presence of respiratory symptoms in patients could represent additional clinical criteria to direct CEP290 genotyping of patients affected with the genetically heterogeneous cone-rod dystrophy subtype of LCA.

Expression of epidermal growth factor receptor, but not K-RAS mutations, is present in congenital cystic airway malformation/congenital pulmonary airway malformation.

Congenital cystic airway malformation/congenital pulmonary airway malformation (CCAM/CPAM) of the lung is a rare but well-described malformative lesion of pulmonary parenchyma characterized by the abnormal maturation of airways along with an increase in terminal respiratory structures, resulting in cysts of variable sizes. Five types have been classified based on morphological analysis. Although the etiology of the lesion is still unclear, recent data suggest that bronchial atresia is a predisposing/associated anomaly. A described association between type 1 CCAM/CPAM and bronchioloalveolar carcinoma suggests that type 1 CCAM/CPAM may predispose to malignant transformation by as yet unidentified tumorigenic mechanisms. Here we studied epidermal growth factor receptor (EGFR) and K-RAS oncogene, 2 biological markers closely associated with tumorigenesis and altered in many types of tumors, including lung carcinomas. For this purpose, we used immunohistochemistry and gene sequencing in paraffin-embedded tissue. Our results demonstrate expression of EGFR in types 1 and 3 CCAM/CPAM, with a distinctive distribution and intensity, compared with that of type 2. Of special interest, mucinous areas in 2 cases of type 1 CCAM/CPAM lacked EGFR expression, whereas adjacent epithelial cystic linings were strongly positive. This supports the hypothesis that mucinous differentiation in CCAM/CPAM, always present in cases with malignant transformation, could be related to other molecular pathways. The K-RAS gene was screened for mutations usually found in lung carcinomas; however, no mutations were present in any of the studied samples. These findings support the notion that EGFR may play an important role in the pathogenesis and phenotype of CCAM/CPAM.

Spectrum of pediatric developmental and genetic renal lesions and associated congenital malformations--an autopsy study from north India.

Pediatric developmental and genetic renal lesions are a known cause of mortality in the perinatal/neonatal period. These lesions are associated with a wide range of extrarenal congenital malformations that influence the outcome of the patients. In this autopsy study, we have analyzed the spectrum of pediatric developmental and genetic renal lesions and their associated congenital malformations. A total of 4,099 autopsies (20 weeks of gestation to 1 year of life) were reviewed, of which 158 cases (3.85%) of pediatric developmental (143 cases) and genetic renal lesions (15 cases) were found. Autosomal recessive polycystic kidney disease was the commonest genetic lesion. Primitive ducts with cuffing of immature mesenchyme--the sine qua non of renal dysplasia--was found in all cases of dysplasia. Associated congenital malformations were seen in all cases and thus a thorough search for them is mandatory. Ductal plate malformation was found in all cases of autosomal recessive polycystic kidney disease and in 1 case of bilateral multicystic dysplasia.

Embryological origins and development of the rat diaphragm.

Textbooks of embryology provide a standard set of drawings and text reflecting the traditional interpretation of phrenic nerve and diaphragm development based on anatomical dissections of embryonic tissue. Here, we revisit this issue, taking advantage of immunohistochemical markers for muscle precursors in conjunction with mouse mutants to perform a systematic examination of phrenic-diaphragm embryogenesis. This includes examining the spatiotemporal relationship of phrenic axon outgrowth and muscle precursors during different stages of myogenesis. Additionally, mutant mice lacking c-met receptors were used to visualize the mesenchymal substratum of the developing diaphragm in the absence of myogenic cells. We found no evidence for contributions to the diaphragm musculature from the lateral body wall, septum transversum, or esophageal mesenchyme, as standard dogma would state. Nor did the data support the hypothesis that the crural diaphragm is of distinct embryological origins. Rather, we found that myogenic cells and axons destined to form the neuromuscular component of the diaphragm coalesce within the pleuroperitoneal fold (PPF). It is the expansion of these components of the PPF that leads to the formation of the diaphragm. Furthermore, we extended these studies to examine the developing diaphragm in an animal model of congenital diaphragmatic hernia (CDH). We find that malformation of the PPF mesenchymal substratum leads to the defect characteristic of CDH. In summary, the data demonstrates that a significant revision of narratives describing normal and pathological development of the diaphragm is warranted.

Early postnatal lethality in Hoxa-5 mutant mice is attributable to respiratory tract defects.

To uncover roles for the Hoxa-5 gene during embryogenesis, we have focused on identifying structural and functional defects in organ systems underlying the perinatal lethality in Hoxa-5 homozygous mutants. Analysis of the mutant phenotype shows that Hoxa-5 is essential for normal organogenesis and function of the respiratory tract. In homozygous newborn mutants, improper tracheal and lung morphogenesis can lead to tracheal occlusion, and to respiratory distress associated with a marked decrease in the production of surfactant proteins. Collectively, these defects likely underlie the pronounced mortality of homozygous mutant pups. Furthermore, the loss of Hoxa-5 function results in altered TTF-1, HNF-3 beta, and N-myc gene expression in the pulmonary epithelium. Since expression of Hoxa-5 is confined to the mesenchymal component of the developing trachea and lung, the effects observed in epithelial cells may result from a disruption of normal epithelial-mesenchymal interactions.