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Biochimica Et Biophysica Acta.... May 2018Mutations in VPS33B and VIPAS39 cause the severe multisystem disorder Arthrogryposis, Renal dysfunction and Cholestasis (ARC) syndrome. Amongst other symptoms, patients...
Mutations in VPS33B and VIPAS39 cause the severe multisystem disorder Arthrogryposis, Renal dysfunction and Cholestasis (ARC) syndrome. Amongst other symptoms, patients with ARC syndrome suffer from severe ichthyosis. Roles for VPS33B and VIPAR have been reported in lysosome-related organelle biogenesis, integrin recycling, collagen homeostasis and maintenance of cell polarity. Mouse knockouts of Vps33b or Vipas39 are good models of ARC syndrome and develop an ichthyotic phenotype. We demonstrate that the skin manifestations in Vps33b and Vipar deficient mice are histologically similar to those of patients with ARC syndrome. Histological, immunofluorescent and electron microscopic analysis of Vps33b and Vipar deficient mouse skin biopsies and isolated primary cells showed that epidermal lamellar bodies, which are essential for skin barrier function, had abnormal morphology and the localisation of lamellar body cargo was disrupted. Stratum corneum formation was affected, with increased corneocyte thickness, decreased thickness of the cornified envelope and reduced deposition of lipids. These defects impact epidermal homeostasis and lead to abnormal barrier formation causing the skin phenotype in Vps33b and Vipar deficient mice and patients with ARC syndrome.
Topics: Animals; Arthrogryposis; Cholestasis; Disease Models, Animal; Epidermis; Humans; Mice; Mice, Knockout; Renal Insufficiency; Vesicular Transport Proteins
PubMed: 29409756
DOI: 10.1016/j.bbadis.2018.01.028 -
Cellular & Molecular Biology Letters Nov 2023The pulmonary surfactant that lines the air-liquid surface within alveoli is a protein-lipid mixture essential for gas exchange. Surfactant lipids and proteins are...
BACKGROUND
The pulmonary surfactant that lines the air-liquid surface within alveoli is a protein-lipid mixture essential for gas exchange. Surfactant lipids and proteins are synthesized and stored in the lamellar body (LB) before being secreted from alveolar type II (AT2) cells. The molecular and cellular mechanisms that regulate these processes are incompletely understood. We previously identified an essential role of general control of amino acid synthesis 5 like 1 (GCN5L1) and the biogenesis of lysosome-related organelle complex 1 subunit 1 (BLOS1) in surfactant system development in zebrafish. Here, we explored the role of GCN5L1 in pulmonary surfactant regulation.
METHOD
GCN5L1 knockout cell lines were generated with the CRISPR/Cas9 system. Cell viability was analyzed by MTT assay. Released surfactant proteins were measured by ELISA. Released surfactant lipids were measured based on coupled enzymatic reactions. Gene overexpression was mediated through lentivirus. The RNA levels were detected through RNA-sequencing (RNA-seq) and quantitative reverse transcription (qRT)- polymerase chain reaction (PCR). The protein levels were detected through western blotting. The cellular localization was analyzed by immunofluorescence. Morphology of the lamellar body was analyzed through transmission electron microscopy (TEM), Lysotracker staining, and BODIPY phosphatidylcholine labeling.
RESULTS
Knocking out GCN5L1 in MLE-12 significantly decreased the release of surfactant proteins and lipids. We detected the downregulation of some surfactant-related genes and misregulation of the ROS-Erk-Foxo1-Cebpα axis in mutant cells. Modulating the activity of the axis or reconstructing the mitochondrial expression of GCN5L1 could partially restore the expression of these surfactant-related genes. We further showed that MLE-12 cells contained many LB-like organelles that were lipid enriched and positive for multiple LB markers. These organelles were smaller in size and accumulated in the absence of GCN5L1, indicating both biogenesis and trafficking defects. Accumulated endogenous surfactant protein (SP)-B or exogenously expressed SP-B/SP-C in adenosine triphosphate-binding cassette transporterA3 (ABCA3)-positive organelles was detected in mutant cells. GCN5L1 localized to the mitochondria and LBs. Reconstruction of mitochondrial GCN5L1 expression rescued the organelle morphology but failed to restore the trafficking defect and surfactant release, indicating specific roles associated with different subcellular localizations.
CONCLUSIONS
In summary, our study identified GCN5L1 as a new regulator of pulmonary surfactant that plays a role in the biogenesis and positioning/trafficking of surfactant-containing LBs.
Topics: Animals; Mice; Alveolar Epithelial Cells; Lamellar Bodies; Lipids; Pulmonary Surfactants; RNA; Surface-Active Agents; Zebrafish
PubMed: 37936104
DOI: 10.1186/s11658-023-00506-0 -
The Journal of Allergy and Clinical... Oct 2014I review how diverse inherited and acquired abnormalities in epidermal structural and enzymatic proteins converge to produce defective permeability barrier function and... (Review)
Review
I review how diverse inherited and acquired abnormalities in epidermal structural and enzymatic proteins converge to produce defective permeability barrier function and antimicrobial defense in patients with atopic dermatitis (AD). Although best known are mutations in filaggrin (FLG), mutations in other member of the fused S-100 family of proteins (ie, hornerin [hrn] and filaggrin 2 [flg-2]); the cornified envelope precursor (ie, SPRR3); mattrin, which is encoded by TMEM79 and regulates the assembly of lamellar bodies; SPINK5, which encodes the serine protease inhibitor lymphoepithelial Kazal-type trypsin inhibitor type 1; and the fatty acid transporter fatty acid transport protein 4 have all been linked to AD. Yet these abnormalities often only predispose to AD; additional acquired stressors that further compromise barrier function, such as psychological stress, low ambient humidity, or high-pH surfactants, often are required to trigger disease. T(H)2 cytokines can also compromise barrier function by downregulating expression of multiple epidermal structural proteins, lipid synthetic enzymes, and antimicrobial peptides. All of these inherited and acquired abnormalities converge on the lamellar body secretory system, producing abnormalities in lipid composition, secretion, and/or extracellular lamellar membrane organization, as well as antimicrobial defense. Finally, I briefly review therapeutic options that address this new pathogenic paradigm.
Topics: Animals; Bodily Secretions; Dermatitis, Atopic; Fatty Acid Transport Proteins; Filaggrin Proteins; Gene-Environment Interaction; Humans; Immunity, Innate; Inclusion Bodies; Intermediate Filament Proteins; Lipid Metabolism; Membrane Proteins; Proteinase Inhibitory Proteins, Secretory; Proteolysis; Serine Peptidase Inhibitor Kazal-Type 5; Skin
PubMed: 25131691
DOI: 10.1016/j.jaci.2014.05.048 -
International Journal of Molecular... Jul 2018is highly expressed in alveolar type II cells, melanocytes, and platelets. These cells are specifically-differentiated cells and contain characteristic intracellular... (Review)
Review
is highly expressed in alveolar type II cells, melanocytes, and platelets. These cells are specifically-differentiated cells and contain characteristic intracellular organelles called lysosome-related organelles, i.e., lamellar bodies in alveolar type II cells, melanosomes in melanocytes, and dense granules in platelets. There are -mutant rodents, i.e., mice and rats. While mice only show oculocutaneous albinism, rats show oculocutaneous albinism and prolonged bleeding time and, hence, are a rat model of Hermansky-Pudlak syndrome (HPS). Most patients with HPS suffer from fatal interstitial pneumonia by middle age. The lungs of both mice and rats show remarkably increased amounts of lung surfactant and conspicuously enlarged lysosome-related organelles, i.e., lamellar bodies, which are also characteristic of the lungs in human HPS. There are 16 mutant HPS-mouse strains, of which ten mutant genes have been identified to be causative in patients with HPS thus far. The gene products of eight of the ten genes constitute one of the three protein complexes, i.e., biogenesis of lysosome-related organelle complex-1, -2, -3 (BLOC-1, -2, -3). Patients with HPS of the mutant BLOC-3 genotype develop interstitial pneumonia. Recently, BLOC-3 has been elucidated to be a guanine nucleotide exchange factor for Rab38. Growing evidence suggests that is an additional candidate gene of human HPS that displays the lung phenotype.
Topics: Animals; Carrier Proteins; Disease Models, Animal; Guanine Nucleotide Exchange Factors; Hermanski-Pudlak Syndrome; Humans; Lung; Lung Diseases, Interstitial; Mice; Nerve Tissue Proteins; Proteins; Pulmonary Surfactants; Rats; rab GTP-Binding Proteins
PubMed: 30060521
DOI: 10.3390/ijms19082203 -
International Journal of Biological... 2022The lamellar body (LB), a concentric structure loaded with surfactant proteins and phospholipids, is an organelle specific to type 2 alveolar epithelial cells (AT2)....
The lamellar body (LB), a concentric structure loaded with surfactant proteins and phospholipids, is an organelle specific to type 2 alveolar epithelial cells (AT2). However, the origin of LBs has not been fully elucidated. We have previously reported that autophagy regulates Weibel-Palade bodies (WPBs) formation, and here we demonstrated that autophagy is involved in LB maturation, another lysosome-related organelle. We found that during development, LBs were transformed from autophagic vacuoles containing cytoplasmic contents such as glycogen. Fusion between LBs and autophagosomes was observed in wild-type neonate mice. Moreover, the markers of autophagic activity, microtubule-associated protein 1 light chain 3B (LC3B), largely co-localized on the limiting membrane of the LB. Both () global knockout and conditional knockdown in AT2 cells in mice led to defects in LB maturation and surfactant protein B production. Additionally, changes in autophagic activity altered LB formation and surfactant protein B production. Taken together, these results suggest that autophagy plays a critical role in the regulation of LB formation during development and the maintenance of LB homeostasis during adulthood.
Topics: Alveolar Epithelial Cells; Animals; Autophagy; Lamellar Bodies; Lysosomes; Mice; Pulmonary Surfactants; Surface-Active Agents
PubMed: 35173542
DOI: 10.7150/ijbs.64285 -
Frontiers in Cell and Developmental... 2021Neonatal respiratory distress syndrome (NRDS) is a type of newborn disorder caused by the deficiency or late appearance of lung surfactant, a mixture of lipids and... (Review)
Review
Neonatal respiratory distress syndrome (NRDS) is a type of newborn disorder caused by the deficiency or late appearance of lung surfactant, a mixture of lipids and proteins. Studies have shown that lung surfactant replacement therapy could effectively reduce the morbidity and mortality of NRDS, and the therapeutic effect of animal-derived surfactant preparation, although with its limitations, performs much better than that of protein-free synthetic ones. Plasmalogens are a type of ether phospholipids present in multiple human tissues, including lung and lung surfactant. Plasmalogens are known to promote and stabilize non-lamellar hexagonal phase structure in addition to their significant antioxidant property. Nevertheless, they are nearly ignored and underappreciated in the lung surfactant-related research. This report will focus on plasmalogens, a minor yet potentially vital component of lung surfactant, and also discuss their biophysical properties and functions as anti-oxidation, structural modification, and surface tension reduction at the alveolar surface. At the end, we boldly propose a novel synthetic protein-free lung surfactant preparation with plasmalogen modification as an alternative strategy for surfactant replacement therapy.
PubMed: 33681198
DOI: 10.3389/fcell.2021.618102 -
European Journal of Obstetrics &... Jan 2020This study aimed to synthesize evidence from published studies about the diagnostic accuracy of lamellar body count (LBC) as a predictor of fetal lung maturity. (Review)
Review
OBJECTIVE
This study aimed to synthesize evidence from published studies about the diagnostic accuracy of lamellar body count (LBC) as a predictor of fetal lung maturity.
STUDY DESIGN
We searched Medline (via PubMed), EBSCO, Web of Science, Scopus and the Cochrane Library for relevant published studies assessing the accuracy of LBC as a predictor of fetal lung maturity. Studies were classified according to the counting essays, centrifugation protocols, and the reported optimum cut off values. Data of the true positive, true negative, false positive, and false negative were extracted and analyzed to calculate the overall sensitivity and specificity of the LBC.
RESULTS
Thirty-one studies were included in the final analysis. Fourteen studies reported data for centrifuged amniotic fluid (AF) samples, 13 studies reported data for uncentrifuged samples, and four studies did not have enough information about whether centrifugation was done. LBC showed an area under the curve >80% in diagnosing lung immaturity with variable cut off values. Pooled analysis showed that LBC a 100% specificity to exclude respiratory distress syndrome (RDS) at a cut off value of 15,000 and 100% sensitivity to diagnose RDS at a cut off value of 55,000.
CONCLUSION
Cases with LBC < 15,000 are considered to have lung immaturity while cases with LBC > 45,000 in centrifuged AF samples or >55,000 in uncentrifuged AF samples are likely to have mature lungs. Cases with LBC ranging between these maturity and immaturity limits should be considered for further evaluation by other lung maturity tests.
PubMed: 32021970
DOI: 10.1016/j.eurox.2019.100059 -
Biochimica Et Biophysica Acta Mar 2014Normal fatty aldehyde and alcohol metabolism is essential for epidermal differentiation and function. Long-chain aldehydes are produced by catabolism of several lipids... (Review)
Review
Normal fatty aldehyde and alcohol metabolism is essential for epidermal differentiation and function. Long-chain aldehydes are produced by catabolism of several lipids including fatty alcohols, sphingolipids, ether glycerolipids, isoprenoid alcohols and certain aliphatic lipids that undergo α- or ω-oxidation. The fatty aldehyde generated by these pathways is chiefly metabolized to fatty acid by fatty aldehyde dehydrogenase (FALDH, alternately known as ALDH3A2), which also functions to oxidize fatty alcohols as a component of the fatty alcohol:NAD oxidoreductase (FAO) enzyme complex. Genetic deficiency of FALDH/FAO in patients with Sjögren-Larsson syndrome (SLS) results in accumulation of fatty aldehydes, fatty alcohols and related lipids (ether glycerolipids, wax esters) in cultured keratinocytes. These biochemical changes are associated with abnormalities in formation of lamellar bodies in the stratum granulosum and impaired delivery of their precursor membranes to the stratum corneum (SC). The defective extracellular SC membranes are responsible for a leaky epidermal water barrier and ichthyosis. Although lamellar bodies appear to be the pathogenic target for abnormal fatty aldehyde/alcohol metabolism in SLS, the precise biochemical mechanisms are yet to be elucidated. Nevertheless, studies in SLS highlight the critical importance of FALDH and normal fatty aldehyde/alcohol metabolism for epidermal function. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier. Guest Editors: Kenneth R. Feingold and Peter Elias.
Topics: Aldehyde Oxidoreductases; Aldehydes; Animals; Epidermis; Fatty Acids; Fatty Alcohols; Humans; Lipid Metabolism; Oxidation-Reduction; Sjogren-Larsson Syndrome
PubMed: 24036493
DOI: 10.1016/j.bbalip.2013.09.001 -
Toxicology and Applied Pharmacology Oct 2020Due to the pandemic of coronavirus disease 2019, the use of disinfectants is rapidly increasing worldwide. Didecyldimethylammonium chloride (DDAC) is an EPA-registered...
Due to the pandemic of coronavirus disease 2019, the use of disinfectants is rapidly increasing worldwide. Didecyldimethylammonium chloride (DDAC) is an EPA-registered disinfectant, it was also a component in humidifier disinfectants that had caused idiopathic pulmonary diseases in Korea. In this study, we identified the possible pulmonary toxic response and mechanism using human bronchial epithelial (BEAS-2B) cells and mice. First, cell viability decreased sharply at a 4 μg/mL of concentration. The volume of intracellular organelles and the ROS level reduced, leading to the formation of apoptotic bodies and an increase of the LDH release. Secretion of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) and matrix metalloproteinase-1 also significantly increased. More importantly, lamellar body-like structures were formed in both the cells and mice exposed to DDAC, and the expression of both the indicator proteins for lamellar body (ABCA3 and Rab11a) and surfactant proteins (A, B, and D) was clearly enhanced. In addition, chronic fibrotic pulmonary lesions were notably observed in mice instilled twice (weekly) with DDAC (500 μg), ultimately resulting in death. Taken together, we suggest that disruption of pulmonary surfactant homeostasis may contribute to DDAC-induced cell death and subsequent pathophysiology and that the formation of lamellar body-like structures may play a role as the trigger. In addition, we propose that the cause of sudden death of mice exposed to DDAC should be clearly elucidated for the safe application of DDAC.
Topics: Animals; Apoptosis; Betacoronavirus; COVID-19; Cell Line; Cell Survival; Coronavirus Infections; Dose-Response Relationship, Drug; Female; Gene Expression Regulation; Humans; Male; Mice; Mice, Inbred ICR; Pandemics; Pneumonia, Viral; Quaternary Ammonium Compounds; SARS-CoV-2
PubMed: 32763356
DOI: 10.1016/j.taap.2020.115182 -
Thorax Nov 1969A 61-year-old man with chronic myeloid leukaemia was treated with busulphan (Myleran). After receiving 1 g. of this drug over a period of 20 months he became dyspnoeic...
A 61-year-old man with chronic myeloid leukaemia was treated with busulphan (Myleran). After receiving 1 g. of this drug over a period of 20 months he became dyspnoeic and developed crepitations in the lungs. Two months later radiographs of the chest revealed peri-hilar infiltrates and subsequently diffuse mottling throughout both lungs. Lung function tests showed a gross impairment of the transfer factor to a quarter of the predicted normal. At necropsy the lungs showed a striking proliferation of granular pneumocytes, many of which had disintegrated to produce intra-alveolar debris, some of which showed organization by fibrous tissue. There was associated interstitial pulmonary fibrosis. Electron microscopy confirmed the desquamated alveolar cells to be type II (granular) pneumocytes containing characteristic lamellar bodies. Many of these osmiophilic bodies, believed to be the source of pulmonary surfactant, had been liberated into the alveolar spaces, with the formation of phospholipid myelin figures and lattices. We think that the basic pathology of busulphan lung is a chemically induced alveolitis with proliferation of granular pneumocytes followed by fibrosis of alveolar walls and intra-alveolar contents.
Topics: Busulfan; Humans; Leukemia, Myeloid; Lung; Lung Diseases; Male; Microscopy, Electron; Middle Aged; Pulmonary Alveoli; Pulmonary Fibrosis; Radiography; Respiratory Function Tests; Spirometry
PubMed: 5260190
DOI: 10.1136/thx.24.6.639