Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0344329 (collapse)
 28,634 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The highly branched mammalian lung relies on surfactant, a mixture of phospholipids, cholesterol, and hydrophobic proteins, to reduce intraalveolar surface tension and prevent lung collapse. Human mutations in the ABCA3 transporter have been associated with childhood respiratory disease of variable severity and onset. Here, we report the generation of Abca3 null mice, which became lethargic and cyanotic and died within 1 h of birth. Tissue blots found ABCA3 expression was highest in lung but was also detectable in other tissues, including the kidney. Gross development of kidney and lung was normal in neonatal Abca3(-/-) pups, but the mice failed to inflate their lungs, leading to death from atelectatic respiratory failure. Ultrastructural analysis of the Abca3(-/-) lungs revealed an absence of surfactant from the alveolar space and a profound loss of mature lamellar bodies, the intracellular storage organelle for surfactant. Mass spectrometry measurement of >300 phospholipids in lung tissue taken from Abca3(-/-) mice showed a dramatic reduction of phosphatidylglycerol (PG) levels as well as selective reductions in phosphatidylcholine species containing short acyl chains. These results establish a requirement of ABCA3 for lamellar body formation and pulmonary surfactant secretion and suggest a unique and critical role for the transporter in the metabolism of pulmonary PG. They also demonstrate the utility of the Abca3 null mouse as a model for a devastating human disease.
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PMID:ABCA3 inactivation in mice causes respiratory failure, loss of pulmonary surfactant, and depletion of lung phosphatidylglycerol. 1714 8

Chemoresistance to anticancer drugs is a major issue in the successful treatment of acute myeloid leukemia (AML). In this study, we developed an AML cell line (AML-2/IDAC) that is resistant to treatment with a combination of idarubicin and cytosine arabinoside (Id/AraC) by chronic exposure for more than 3 months. We then investigated the ability of indomethacin to alleviate the chemoresistance of AML-2/IDAC cells. Treatment with indomethacin alone induced growth arrest, but not the death of AML-2/IDAC cells. However, when AML-2/IDAC cells were treated with combinations of indomethacin and Id/AraC, the cell death and apoptosis rate of AML-2/IDAC cells were significantly increased in a dose- and time-dependent manner. The combined treatment with indomethacin and Id/AraC caused the collapse of the mitochondrial membrane potential and was also demonstrated to enhance the activities of caspase-3 and -8 in AML-2/IDAC cells. Furthermore, indomethacin down-regulated expression of the ABCA3 and MRP1 genes, which were over-expressed in AML-2/IDAC cells. Taken together, the results of this study suggest that indomethacin can be used to increase the therapeutic potential against drug-resistant AML when combined with anti-leukemic drugs.
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PMID:Alleviation of the drug-resistant phenotype in idarubicin and cytosine arabinoside double-resistant acute myeloid leukemia cells by indomethacin. 1836 Jul 21

Mutations in the genes encoding the surfactant proteins B and C (SP-B and SP-C) and the phospholipid transporter, ABCA3, are associated with respiratory distress and interstitial lung disease in the pediatric population. Expression of these proteins is regulated developmentally, increasing with gestational age, and is critical for pulmonary surfactant function at birth. Pulmonary surfactant is a unique mixture of lipids and proteins that reduces surface tension at the air-liquid interface, preventing collapse of the lung at the end of expiration. SP-B and ABCA3 are required for the normal organization and packaging of surfactant phospholipids into specialized secretory organelles, known as lamellar bodies, while both SP-B and SP-C are important for adsorption of secreted surfactant phospholipids to the alveolar surface. In general, mutations in the SP-B gene SFTPB are associated with fatal respiratory distress in the neonatal period, and mutations in the SP-C gene SFTPC are more commonly associated with interstitial lung disease in older infants, children, and adults. Mutations in the ABCA3 gene are associated with both phenotypes. Despite this general classification, there is considerable overlap in the clinical and histologic characteristics of these genetic disorders. In this review, similarities and differences in the presentation of these disorders with an emphasis on their histochemical and ultrastructural features will be described, along with a brief discussion of surfactant metabolism. Mechanisms involved in the pathogenesis of lung disease caused by mutations in these genes will also be discussed.
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PMID:Genetic disorders of surfactant dysfunction. 1922 77

Adaptation to respiration at birth depends upon the synthesis of pulmonary surfactant, a lipid-protein complex that reduces surface tension at the air-liquid interface in the alveoli and prevents lung collapse during the ventilatory cycle. Herein, we demonstrated that the gene encoding a subunit of the endoplasmic reticulum membrane complex, EMC3, also known as TMEM111 (Emc3/Tmem111), was required for murine pulmonary surfactant synthesis and lung function at birth. Conditional deletion of Emc3 in murine embryonic lung epithelial cells disrupted the synthesis and packaging of surfactant lipids and proteins, impaired the formation of lamellar bodies, and induced the unfolded protein response in alveolar type 2 (AT2) cells. EMC3 was essential for the processing and routing of surfactant proteins, SP-B and SP-C, and the biogenesis of the phospholipid transport protein ABCA3. Transcriptomic, lipidomic, and proteomic analyses demonstrated that EMC3 coordinates the assembly of lipids and proteins in AT2 cells that is necessary for surfactant synthesis and function at birth.
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PMID:EMC3 coordinates surfactant protein and lipid homeostasis required for respiration. 2908 21