Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019270 (hernia)
 15,856 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We compared proliferation (growth) and differentiation (development) related proteins in normal and hypoplastic fetal murine lungs. The hypoplastic lungs were created in CD-1 fetal mice by nitrofen exposure (25 mg per pregnant mouse given intragastrically on gestational day 8 [Gd8]), as published earlier. The lungs were harvested at Gd14, 16, 19 and from neonates. Immunoblot analyses were carried out for transcription factors (oncogenic proteins, nuclear receptor, and transmembrane receptor proteins) in severely hypoplastic murine fetal lungs with coexistent diaphragmatic hernia, and results were compared with those derived from normal lungs of equivalent age. These proteins have proposed roles in the regulation of proliferation and differentiation processes of fetal lungs. We have shown that the product of the oncogene c-myc was reduced in hypoplastic lungs at all stages of gestation, whereas c-Fos protein levels were variable. These proteins are known to regulate transcription of various developmental proteins, such as those responsible for proliferation and differentiation. Further, the nuclear transcription factors thyroid transcription factor-1 (TITF-1) and glucocorticoid receptor (GR) were reduced, and thyroid hormone receptor (TR) and retinoic acid receptors (RARs) were inhibited in severely hypoplastic lungs compared to normal lungs of equivalent gestational stage, except in neonatal lungs, where signals for RARs were seen. TITF-1 is known to localize in bronchial epithelial cells in developing lungs. It is restricted to type II pneumocytes with gestational development in the normal lungs and regulates surfactant proteins. Earlier, we have reported that surfactant proteins are reduced in hypoplastic lungs. In the current study, reduced GR and TITF-1 proteins may play a role in reducing surfactant proteins in the hypoplastic lungs. The significant inhibition in TR and RARalpha in the severely hypoplastic lungs reflects on affected epithelial cell maturation and alveolar formation, respectively. Altered RARbeta levels correlate with affected lung growth and branching morphogenesis of nitrofen-exposed lungs. A transmembrane receptor protein EGFR was reduced in hypoplastic lungs, suggesting the involvement of altered mesenchymal-epithelial signal transduction pathways. We conclude (1) Our data suggest altered levels of various nuclear transcription factors in the murine fetal hypoplastic lungs; (2) Reduced levels TITF-1 protein in hypoplastic lungs may have caused the functional immaturity of distal lung, immature airways and thus may affect overall differentiation of lungs. These results correlated with low levels of surfactant proteins in these lungs; (3) TR and RAR inhibition indicate their roles through reduced or retarded proliferation and differentiation processes in the severely hypoplastic lungs; (4) GR down-regulation in developing fetal murine hypoplastic lungs indicate delayed development, and GR up-regulation in affected neonates may be induced by stress/stretch caused at birth due to air-breathing; (5) Down- regulation of EGFR indicate altered mesenchymal-epithelial interactions and possible influence on lung proliferation and differentiation.
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PMID:Down-regulation of regulatory proteins for differentiation and proliferation in murine fetal hypoplastic lungs: altered mesenchymal-epithelial interactions. 1147 30

Congenital diaphragmatic hernia (CDH) occurs in approximately 1:2,500 human births and has high morbidity and mortality rates, primarily due to pulmonary hypoplasia and pulmonary hypertension. Tracheal occlusion (TO), in experimental animals, distends lungs and increases lung growth and alveolar type I cell maturation but decreases surfactant components and reduces alveolar type II cell density. We examined effects of CDH and CDH+TO on lung growth and maturation in fetal rats. To induce CDH, we administered nitrofen (100 mg) to dams at 9.5 days of gestation. We compared lungs from fetuses with CDH, CDH+TO, and those exposed to nitrofen without CDH. CDH decreased lung wet weight bilaterally (P < 0.0001) and DNA content in lung ipsilateral to CDH (P < 0.05). CDH+TO significantly increased lung wet weights bilaterally; DNA content was intermediate between CDH and NC. To evaluate effects on the distal pulmonary epithelium, we examined surfactant mRNA and protein levels, type I and II cell-specific markers (RTI(40) and RTII(70), respectively), and transcriptional regulator thyroid transcription factor-1 (TTF-1). Decreased lung distension (due to CDH) increased SP-C mRNA and TTF-1 protein expression and reduced RTI(40) (P < 0.05 for all). Increased lung distension (due to CDH+TO) reduced expression of SP mRNAs and pro-SP-C and TTF-1 proteins and enhanced expression of RTI(40) (mRNA and protein; P < 0.05 for all). We conclude that CDH+TO partially reverses effects of CDH; it corrects the pulmonary hypoplasia and restores type I cell differentiation but adversely affects SP expression in type II cells. These effects may be mediated through changes in TTF-1 expression.
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PMID:Congenital diaphragmatic hernia, tracheal occlusion, thyroid transcription factor-1, and fetal pulmonary epithelial maturation. 1576 45

Pulmonary hypoplasia is the principal cause of morbidity and mortality in infants with congenital diaphragmatic hernia (CDH). Still, relatively little is known about the mechanisms causing lung hypoplasia associated with CDH. The differentiation from alveolar epithelial cells type II (AECs-II) into alveolar epithelial cells type I (AECs-I) is one of the key processes in lung development in late gestation. It is well known that increased lung expansion promotes differentiation into AECs-I phenotype, whereas reduced lung expansion promotes AECs-II phenotype. The recent availability of cell-specific molecule markers for AECs-I and AECs-II has provided an opportunity to study the various characteristics of these two cell types. To test the hypothesis that the differentiation of AECs-II to AECs-I is impaired in the CDH hypoplastic lung, we investigated molecular markers for AECs-I [ICAM-1, T1alpha, aquaporin 5 (AQP5)] and molecular markers for AECs-II [thyroid transcription factor-1 (Ttf-1), surfactant protein (SP)-B and C] in the nitrofen-induced CDH lung. Fetal rat lungs of normal (n = 7) and nitrofen-treated (n = 14) dams were harvested on embryonic day 21. The expression of the ICAM1, T1alpha, AQP5, SP-B, C and Ttf-1 was analyzed in each lung by real-time reverse transcription polymerase chain reaction. Immunohistochemical studies were performed to evaluate the protein expression level of ICAM1 and Ttf1. Expression levels of ICAM-1, T1alpha and AQP5 were significantly reduced (P < 0.05) in the lungs from nitrofen-treated CDH animals compared to normal controls. ICAM-1 and AQP5 immunohistochemistry showed a diffuse pattern of expression in the alveolar cells in normal lungs. By contrast, the ICAM-1 and AQP5 positive cells were markedly reduced in hypoplastic lungs with CDH. On the other hand, the expression levels of Ttf-1, SP-B and C were significantly (P < 0.05) increased in the lungs from nitrofen-treated CDH animals compared to normal controls. The population of Ttf-1 positive cells was slightly increased in the lungs from nitrofen-treated animals in immunohistochemical study. Our results demonstrate that there is significant reduction in the proportion of AECs-I and increase in the proportion of AECs-II in the hypoplastic lung in the nitrofen-induced CDH. This data provides the first evidence to support the hypothesis that AEC differentiation is impaired in CDH hypoplastic lung.
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PMID:Impaired alveolar epithelial cell differentiation in the hypoplastic lung in nitrofen-induced congenital diaphragmatic hernia. 1724 93