Transmission electron microscopy (TEM) analysis of ciliary ultrastructure is classically used for the diagnosis of primary ciliary dyskinesia (PCD). We report our extensive experience of TEM analysis ...in a large series of patients in order to evaluate its feasibility and results. TEM analysis performed in 1,149 patients with suspected PCD was retrospectively reviewed. Biopsies (1,450) were obtained from nasal (44%) or bronchial (56%) mucosa in children (66.5%) and adults (33.5%). TEM analysis was feasible in 71.4% of patients and showed a main defect suggestive of PCD in 29.9%. TEM was more feasible in adults than in children, regardless of the biopsy site. Main defects suggestive of PCD were found in 76.9% of patients with sinopulmonary symptoms and in only 0.4% of patients with isolated upper and 0.4% with isolated lower respiratory tract infections. The defect pattern was similar in children and adults, involving dynein arms (81.2%) or central complex (CC) (18.8%). Situs inversus was never observed in PCD patients with CC defect. Kartagener syndrome with normal ciliary ultrastructure was not an exceptional condition (10.2% of PCD). In conclusion, TEM analysis is feasible in most patients and is particularly useful for PCD diagnosis in cases of sinopulmonary syndrome of unknown origin.
NALP proteins, also known as NLRPs, belong to the CATERPILLER protein family involved, like Toll-like receptors, in the recognition of microbial molecules and the subsequent activation of ...inflammatory and immune responses. Current advances in the function of NALPs support the recently proposed model of a disease continuum bridging autoimmune and autoinflammatory disorders. Among these diseases, hereditary periodic fevers (HPFs) are Mendelian disorders associated with sequence variations in very few genes; these variations are mostly missense mutations whose deleterious effect, which is particularly difficult to assess, is often questionable. The growing number of identified sporadic cases of periodic fever syndrome, together with the lack of discriminatory clinical criteria, has greatly hampered the identification of new disease-causing genes, a step that is, however, essential for appropriate management of these disorders. Using a candidate gene approach, we identified nonambiguous mutations in NALP12 (i.e., nonsense and splice site) in two families with periodic fever syndromes. As shown by means of functional studies, these two NALP12 mutations have a deleterious effect on NF-κB signaling. Overall, these data identify a group of HPFs defined by molecular defects in NALP12, opening up new ways to manage these disorders. The identification of these first NALP12 mutations in patients with autoinflammatory disorder also clearly demonstrates the crucial role of NALP12 in inflammatory signaling pathways, thereby assigning a precise function to this particular member of an emerging family of proteins whose putative biological properties are currently inferred essentially through in vitro means.
Cryopyrin-associated periodic syndromes (CAPS) consist of a continuum of autoinflammatory diseases caused by a defect in interleukin 1β regulation. Although symptoms may vary widely, the discovery, ...in 2001, of the gene involved (NLRP3) has dramatically helped diagnosis.
To define the spectrum and prevalence of NLRP3 mutations in France and to delineate initial criteria before molecular analysis.
Retrospective review (2001-9) of genetic analysis data and request forms of patients living in France with an NLRP3 mutation since the set up of CAPS molecular diagnosis by the three French laboratories providing this test (GenMAI network).
Over 800 analyses of this gene have been conducted, identifying 135 cases with an NLRP3 mutation (55 probands; 33 multiplex families); the estimated prevalence in France was equal to 1/360 000. A total of 21 different sequence variants were detected, among which four are common and nine are new mutations.
Although the number of NLRP3 test requests has doubled over the past 5 years, genetic screening has not contributed to enhanced detection of new index cases each year. There are two possible reasons for this: (i) no clinical prerequisite for genetic diagnosis and (ii) few new large families are now identified (unlike the initial study based on a selection by linkage). A set of initial clinical criteria have been drawn up which it is recommended should be fulfilled before a patient is tested: at least three recurrent bouts, age at disease onset < 20 years and elevated levels of C-reactive protein, especially in individuals with urticaria and moderate fever.
Among the genetic factors playing a key role in the etiology of intellectual disabilities (IDs) and autism spectrum disorders (ASDs), several encode RNA-binding proteins (RBPs). In this study, we ...deciphered the molecular and cellular bases of ID-ASD in a patient followed from birth to the age of 21, in whom we identified a de novo CSDE1 (Cold Shock Domain-containing E1) nonsense variation. CSDE1 encodes an RBP that regulates multiple cellular pathways by monitoring the translation and abundance of target transcripts. Analyses performed on the patient's primary fibroblasts showed that the identified CSDE1 variation leads to haploinsufficiency. We identified through RNA-seq assays the Wnt/β-catenin signaling and cellular adhesion as two major deregulated pathways. These results were further confirmed by functional studies involving Wnt-specific luciferase and substrate adhesion assays. Additional data support a disease model involving APC Down-Regulated-1 (APCDD1) and cadherin-2 (CDH2), two components of the Wnt/β-catenin pathway, CDH2 being also pivotal for cellular adhesion. Our study, which relies on both the deep phenotyping and long-term follow-up of a patient with CSDE1 haploinsufficiency and on ex vivo studies, sheds new light on the CSDE1-dependent deregulated pathways in ID-ASD.
Neutrophilic dermatoses Delaleu, J.; Lepelletier, C.; Calugareanu, A. ...
La revue de medecine interne,
12/2022, Letnik:
43, Številka:
12
Journal Article
Recenzirano
Odprti dostop
Neutrophilic dermatoses (ND) are a group of inflammatory skin conditions characterized by a neutrophilic infiltrate on histopathology with no evidence of infection. ND are classified based upon the ...localization of neutrophils within the skin and clinical features. Recent findings suggest that ND are due to two main mechanisms: i) a polyclonal hereditary activation of the innate immune system (polygenic or monogenic); or ii) a clonal somatic activation of myeloid cells such as encountered in myelodysplastic syndrome or VEXAS syndrome. ND belong to internal medicine as a great number of patients with ND suffer from an underlying condition (such as hematological malignancy, inflammatory bowel disease, auto-immune and auto-inflammatory diseases). ND are diagnoses of exclusion and physicians should always consider differential diagnoses, particularly skin infections. Here, we review the pathophysiology and classification of the main ND (i.e., subcorneal pustular dermatosis (Sneddon-Wilkinson Disease) and Intercellular IgA dermatoses, aseptic pustulosis of the folds, Sweet syndrome, neutrophilic eccrine hidradenitis, pyoderma gangrenosum, erythema elevatum diutinum, neutrophilic urticarial dermatosis and neutrophilic panniculitis), their clinical and histopathological features, and we highlight the investigations that are useful to identify ND-associated diseases and to exclude the differential diagnoses.
Background:
Nasal polyposis, a chronic inflammatory disease affecting the upper airways, is a valuable and accessible model to investigate the mechanisms underlying chronic inflammation. The main ...objective of this study was to investigate a potential involvement of the unfolded protein response (UPR) in the context of oxidative stress and inflammation in nasal epithelial cells from nasal polyps (NP).
Methods:
Epithelial cells from NP (n = 20) and normal mucosa (Controls, n = 15) in primary culture were analyzed by global proteomic approach and cell biology techniques for the glucose‐regulated protein 78 (GRP78), the spliced X‐box‐binding protein 1 (sXBP‐1), the glucose‐regulated protein 94 (GRP94), and the calreticulin (immunoblot, mass spectrometry, immunocytochemistry).
Results:
Proteomics analysis of human nasal epithelial cells in culture revealed the activation of the unfolded protein response in NP. Systematic cell biology and biochemical analysis of two markers (GRP78, sXBP‐1) in the presence and absence of oxidative stress in NP showed a susceptibility of the unfolded protein response to oxidative stress compared to controls at least partially linked to an abnormal redox state of the protein disulfide‐isomerase 4. This unfolded protein response was correlated with mitochondrial depolarization and secretion of interleukin 8 (IL‐8) and leukotriene B4 (LTB4) and was prevented by mitochondrial antioxidant.
Conclusions:
We show the existence of UPR in nasal epithelial cells that is linked to oxidative stress leading to IL‐8 and LTB4 secretions. These mechanisms may participate in chronic inflammation in nasal polyposis.
The innate immune system, which corresponds to the first line of defense against microorganisms, brings into play cell surface and intracellular sensors that detect pathogen ligands and danger ...signals. Among them, NOD-like receptors (NLRs) are intracellular proteins involved in inflammatory signaling pathways. NLRs are part of multiprotein complexes, called inflammasomes, which usually bring into play a NLR, an adaptor protein called ASC, and the pro-inflammatory caspase 1 protein. The activation of inflammasome by different stimuli triggers the proteolytic cleavage of pro-caspase 1 into active caspase 1, which, in turn, converts pro-interleukin 1β (pro-IL1β) into the mature IL1β. IL1β plays a crucial role in systemic inflammation due to its ability to induce the expression of a large panel of pro-inflammatory genes and to act on various target organs. Mutations in NLR genes are responsible for several autoinflammatory and/or autoimmune disorders. For example, mutations in NLRP3, which are responsible for three Mendelian autoinflammatory disorders called cryopyrinopathies, lead to inflammasome autoactivation. Peripheral blood mononuclear cells from patients carrying NLRP3 mutations secrete high levels of IL1β; in many patients presenting with autoinflammatory disorders, blocking IL1 activity by anti-IL1 therapy significantly improves their manifestations. The mechanisms leading to IL1β hypersecretion in other autoinflammatory disorders remain to be identified, as is the case for the role of each inflammasome in vivo. Better knowledge in this field should also contribute to the development of new anti-inflammatory treatments.
Introduction Chez l’enfant insuffisant somatotrope, le bénéfice statural d’un traitement par hormone de croissance (GH) est démontré. Chez l’adulte, la GH améliore les paramètres métaboliques. Son ...utilité pour la croissance n’est pas classique, en raison de la fusion des cartilages de conjugaison. Nous rapportons la croissance sous GH d’un patient adulte, porteur d’une insuffisance antéhypophysaire congénitale. Observation Le patient, d’origine tunisienne, né de parents non apparentés et sans antécédent familial de petite taille, a été adressé à l’âge de 28 ans pour impubérisme. L’examen clinique montrait un poids de 54 kg, une taille de 145 cm pour une taille cible de 177 cm, un stade pubertaire G1P1, un testicule gauche unique de 1 mL et une surdité droite. Son âge osseux était de 14 ans. Sur le plan hormonal, il existait un tableau d’insuffisance antéhypophysaire globale (IGF1 = 11 ng/mL ; GH = 0 sous stimulation), sans diabète insipide. L’IRM hypophysaire montrait une hypoplasie antéhypophysaire et de la tige avec une posthypophyse ectopique. L’analyse génétique (séquençage Sanger) a exclu une mutation des gènes HESX1 , SOX3 , LHX3 et LHX4 . Après 36 mois de traitement substitutif par hydrocortisone, GH (1,5 mg/jour), L-thyroxine puis testostérone (50 puis 125 mg/mois), le développement pubertaire est G4P4 avec une taille de 158,5 cm. Le patient a développé un diabète sans auto-immunité 2 mois après le début du traitement. Discussion Ce cas clinique rapporte un effet très bénéfique du traitement par GH, administré à des doses pédiatriques chez un patient adulte, insuffisant antéhypophysaire, non traité dans l’enfance. L’association à une insuffisance gonadotrope jamais substituée a probablement potentialisé le gain statural.
Background: Epithelial damage and modifications of cell differentiation are frequent in airway diseases with chronic inflammation, in which transforming growth factor‐β1 (TGF‐β1) plays an important ...role. The aim of this study was to evaluate the differentiation of human nasal epithelial cells (HNEC) after wound healing and the potential effects of TGF‐β1.
Methods: Basal, mucus, and ciliated cells were characterized by cytokeratin‐14, MUC5AC, and βIV tubulin immunodetection, respectively. Their expression was evaluated in situ in nasal polyps and in an in vitro model of wound healing in primary cultures of HNEC after wound closure, under basal conditions and after TGF‐β1 supplementation. Using RT‐PCR, the effects of TGF‐β1 on MUC5AC and DNAI1 genes, specifically transcribed in mucus and ciliated cells, were evaluated.
Results: In situ, high TGF‐β1 expression was associated with low MUC5AC and βIV tubulin expression. In vitro, under basal conditions, MUC5AC expression remained stable, cytokeratin‐14 expression was strong and decreased with time, while βIV tubulin expression increased. Transforming growth factor‐β1 supplementation downregulated MUC5AC and βIV tubulin expression as well as MUC5AC and DNAI1 transcripts.
Conclusion: After a wound, differentiation into mucus and ciliated cells was possible and partially inhibited in vitro by TGF‐β1, a cytokine that may be involved in epithelial remodeling observed in chronic airway diseases.
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