1
|
Garavaglia ML, Bodega F, Porta C, Milzani A, Sironi C, Dalle-Donne I. Molecular Impact of Conventional and Electronic Cigarettes on Pulmonary Surfactant. Int J Mol Sci 2023; 24:11702. [PMID: 37511463 PMCID: PMC10380520 DOI: 10.3390/ijms241411702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/11/2023] [Accepted: 07/15/2023] [Indexed: 07/30/2023] Open
Abstract
The alveolar epithelium is covered by a non-cellular layer consisting of an aqueous hypophase topped by pulmonary surfactant, a lipo-protein mixture with surface-active properties. Exposure to cigarette smoke (CS) affects lung physiology and is linked to the development of several diseases. The macroscopic effects of CS are determined by several types of cell and molecular dysfunction, which, among other consequences, lead to surfactant alterations. The purpose of this review is to summarize the published studies aimed at uncovering the effects of CS on both the lipid and protein constituents of surfactant, discussing the molecular mechanisms involved in surfactant homeostasis that are altered by CS. Although surfactant homeostasis has been the topic of several studies and some molecular pathways can be deduced from an analysis of the literature, it remains evident that many aspects of the mechanisms of action of CS on surfactant homeostasis deserve further investigation.
Collapse
Affiliation(s)
| | - Francesca Bodega
- Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di Milano, 20133 Milan, Italy
| | - Cristina Porta
- Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di Milano, 20133 Milan, Italy
| | - Aldo Milzani
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy
| | - Chiara Sironi
- Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di Milano, 20133 Milan, Italy
| | - Isabella Dalle-Donne
- Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milan, Italy
| |
Collapse
|
2
|
Revercomb L, Hanmandlu A, Wareing N, Akkanti B, Karmouty-Quintana H. Mechanisms of Pulmonary Hypertension in Acute Respiratory Distress Syndrome (ARDS). Front Mol Biosci 2021; 7:624093. [PMID: 33537342 PMCID: PMC7848216 DOI: 10.3389/fmolb.2020.624093] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/09/2020] [Indexed: 12/19/2022] Open
Abstract
Background: Acute respiratory distress syndrome (ARDS) is a severe and often fatal disease. The causes that lead to ARDS are multiple and include inhalation of salt water, smoke particles, or as a result of damage caused by respiratory viruses. ARDS can also arise due to systemic complications such as blood transfusions, sepsis, or pancreatitis. Unfortunately, despite a high mortality rate of 40%, there are limited treatment options available for ARDS outside of last resort options such as mechanical ventilation and extracorporeal support strategies. Aim of review: A complication of ARDS is the development of pulmonary hypertension (PH); however, the mechanisms that lead to PH in ARDS are not fully understood. In this review, we summarize the known mechanisms that promote PH in ARDS. Key scientific concepts of review: (1) Provide an overview of acute respiratory distress syndrome; (2) delineate the mechanisms that contribute to the development of PH in ARDS; (3) address the implications of PH in the setting of coronavirus disease 2019 (COVID-19).
Collapse
Affiliation(s)
- Lucy Revercomb
- Department of BioSciences, Rice University, Houston, TX, United States
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Ankit Hanmandlu
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Nancy Wareing
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Bindu Akkanti
- Divisions of Critical Care, Pulmonary and Sleep Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Harry Karmouty-Quintana
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
- Divisions of Critical Care, Pulmonary and Sleep Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
| |
Collapse
|
3
|
Bartman CM, Matveyenko A, Prakash YS. It's about time: clocks in the developing lung. J Clin Invest 2020; 130:39-50. [PMID: 31895049 DOI: 10.1172/jci130143] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The discovery of peripheral intracellular clocks revealed circadian oscillations of clock genes and their targets in all cell types, including those in the lung, sparking exploration of clocks in lung disease pathophysiology. While the focus has been on the role of these clocks in adult airway diseases, clock biology is also likely to be important in perinatal lung development, where it has received far less attention. Historically, fetal circadian rhythms have been considered irrelevant owing to lack of external light exposure, but more recent insights into peripheral clock biology raise questions of clock emergence, its concordance with tissue-specific structure/function, the interdependence of clock synchrony and functionality in perinatal lung development, and the possibility of lung clocks in priming the fetus for postnatal life. Understanding the perinatal molecular clock may unravel mechanistic targets for chronic airway disease across the lifespan. With current research providing more questions than answers, it is about time to investigate clocks in the developing lung.
Collapse
Affiliation(s)
| | - Aleksey Matveyenko
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Y S Prakash
- Department of Anesthesiology and Perioperative Medicine and.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| |
Collapse
|
4
|
Gao B, Xie W, Wu X, Wang L, Guo J. Functionally analyzing the important roles of hepatocyte nuclear factor 3 (FoxA) in tumorigenesis. Biochim Biophys Acta Rev Cancer 2020; 1873:188365. [PMID: 32325165 DOI: 10.1016/j.bbcan.2020.188365] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/14/2020] [Accepted: 04/14/2020] [Indexed: 12/19/2022]
Abstract
Transcriptional factors (TFs) play a central role in governing gene expression under physiological conditions including the processes of embryonic development, metabolic homeostasis and response to extracellular stimuli. Conceivably, the aberrant dysregulations of TFs would dominantly result in various human disorders including tumorigenesis, diabetes and neurodegenerative diseases. Serving as the most evolutionarily reserved TFs, Fox family TFs have been explored to exert distinct biological functions in neoplastic development, by manipulating diverse gene expression. Recently, among the Fox family members, the pilot roles of FoxAs attract more attention due to their functions as both pioneer factor and transcriptional factor in human tumorigenesis, particularly in the sex-dimorphism tumors. Therefore, the pathological roles of FoxAs in tumorigenesis have been well-explored in modulating inflammation, immune response and metabolic homeostasis. In this review, we comprehensively summarize the impressive progression of FoxA functional annotation, clinical relevance, upstream regulators and downstream effectors, as well as valuable animal models, and highlight the potential strategies to target FoxAs for cancer therapies.
Collapse
Affiliation(s)
- Bing Gao
- Institute of Precision Medicine, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510275, China
| | - Wei Xie
- Institute of Precision Medicine, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510275, China
| | - Xueji Wu
- Institute of Precision Medicine, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510275, China
| | - Lei Wang
- Institute of Precision Medicine, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510275, China
| | - Jianping Guo
- Institute of Precision Medicine, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510275, China.
| |
Collapse
|
5
|
Natarajan K, Gangam K, Meganathan V, Gottipati KR, Mitchell C, Boggaram V. Organic dust inhibits surfactant protein expression by reducing thyroid transcription factor-1 levels in human lung epithelial cells. Innate Immun 2020; 25:118-131. [PMID: 30774012 PMCID: PMC6830861 DOI: 10.1177/1753425919827360] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Exposure to organic dust is a risk factor for the development of respiratory
diseases. Surfactant proteins (SP) reduce alveolar surface tension and modulate
innate immune responses to control lung inflammation. Therefore, changes in SP
levels could contribute to the development of organic-dust-induced respiratory
diseases. Because information on the effects of organic dust on SP levels is
lacking, we studied the effects of dust from a poultry farm on SP expression. We
found that dust extract reduced SP-A and SP-B mRNA and protein levels in H441
human lung epithelial cells by inhibiting their promoter activities, but did not
have any effect on SP-D protein levels. Dust extract also reduced SP-A and SP-C
levels in primary human alveolar epithelial cells. The inhibitory effects were
not due to LPS or protease activities present in dust extract or mediated via
oxidative stress, but were dependent on a heat-labile factor(s). Thyroid
transcription factor-1, a key transcriptional activator of SP expression, was
reduced in dust-extract-treated cells, indicating that its down-regulation
mediates inhibition of SP levels. Our study implies that down-regulation of SP
levels by organic dust could contribute to the development of lung inflammation
and respiratory diseases in humans.
Collapse
Affiliation(s)
- Kartiga Natarajan
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, USA
| | - Keerthi Gangam
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, USA
| | - Velmurugan Meganathan
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, USA
| | - Koteswara R Gottipati
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, USA
| | - Courtney Mitchell
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, USA
| | - Vijay Boggaram
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, USA
| |
Collapse
|
6
|
Bein K, Di Giuseppe M, Mischler SE, Ortiz LA, Leikauf GD. LPS-treated macrophage cytokines repress surfactant protein-B in lung epithelial cells. Am J Respir Cell Mol Biol 2013; 49:306-15. [PMID: 23590297 PMCID: PMC3824031 DOI: 10.1165/rcmb.2012-0283oc] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 03/07/2013] [Indexed: 02/04/2023] Open
Abstract
In the mouse lung, Escherichia coli LPS can decrease surfactant protein-B (SFTPB) mRNA and protein concentrations. LPS also regulates the expression, synthesis, and concentrations of a variety of gene and metabolic products that inhibit SFTPB gene expression. The purpose of the present study was to determine whether LPS acts directly or indirectly on pulmonary epithelial cells to trigger signaling pathways that inhibit SFTPB expression, and whether the transcription factor CCAAT/enhancer binding protein (C/EBP)-β (CEBPB) is a downstream inhibitory effector. To investigate the mechanism of SFTPB repression, the human pulmonary epithelial cell lines NCI-H441 (H441) and NCI-H820 (H820) and the mouse macrophage-like cell line RAW264.7 were treated with LPS. Whereas LPS did not decrease SFTPB transcripts in H441 or H820 cells, the conditioned medium of LPS-treated RAW264.7 cells decreased SFTPB transcripts in H441 and H820 cells, and inhibited SFTPB promoter activity in H441 cells. In the presence of neutralizing anti-tumor necrosis factor (TNF) antibodies, the conditioned medium of LPS-treated RAW264.7 cells did not inhibit SFTPB promoter activity. In H441 cells treated with recombinant TNF protein, SFTPB transcripts decreased, whereas CEBPB transcripts increased and the transient coexpression of CEBPB decreased SFTPB promoter activity. Further, CEBPB short, interfering RNA increased basal SFTPB transcripts and countered the decrease of SFTPB transcripts by TNF. Together, these findings suggest that macrophages participate in the repression of SFTPB expression by LPS, and that macrophage-released cytokines (including TNF) regulate the transcription factor CEBPB, which can function as a downstream transcriptional repressor of SFTPB gene expression in pulmonary epithelial cells.
Collapse
Affiliation(s)
- Kiflai Bein
- Department of Environmental and Occupational Health, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15219-3130, USA.
| | | | | | | | | |
Collapse
|
7
|
Das A, Acharya S, Gottipati KR, McKnight JB, Chandru H, Alcorn JL, Boggaram V. Thyroid transcription factor-1 (TTF-1) gene: identification of ZBP-89, Sp1, and TTF-1 sites in the promoter and regulation by TNF-α in lung epithelial cells. Am J Physiol Lung Cell Mol Physiol 2011; 301:L427-40. [PMID: 21784970 DOI: 10.1152/ajplung.00090.2011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Thyroid transcription factor-1 (TTF-1/Nkx2.1/TITF1) is a homeodomain-containing transcription factor essential for the morphogenesis and differentiation of the lung. In the lung, TTF-1 controls the expression of surfactant proteins that are essential for lung stability and lung host defense. In this study, we identified functionally important transcription factor binding sites in the TTF-1 proximal promoter and studied tumor necrosis factor-α (TNF-α) regulation of TTF-1 expression. TNF-α, a proinflammatory cytokine, has been implicated in the pathogenesis of acute respiratory distress syndrome (ARDS) and inhibits surfactant protein levels. Deletion analysis of TTF-1 5'-flanking DNA indicated that the TTF-1 proximal promoter retained high-level activity. Electrophoretic mobility shift assay, chromatin immunoprecipitation, and mutational analysis experiments identified functional ZBP-89, Sp1, Sp3, and TTF-1 sites in the TTF-1 proximal promoter. TNF-α inhibited TTF-1 protein levels in H441 and primary alveolar type II cells. TNF-α inhibited TTF-1 gene transcription and promoter activity, indicating that transcriptional mechanisms play important roles in the inhibition of TTF-1 levels. TNF-α inhibited TTF-1 but not Sp1 or hepatocyte nuclear factor-3 DNA binding to TTF-1 promoter. Transactivation experiments in A549 cells indicated that TNF-α inhibited TTF-1 promoter activation by exogenous Sp1 and TTF-1 without altering their levels, suggesting inhibition of transcriptional activities of these proteins. TNF-α inhibition of TTF-1 expression was associated with increased threonine, but not serine, phosphorylation of Sp1. Because TTF-1 serves as a positive regulator for surfactant protein gene expression, TNF-α inhibition of TTF-1 expression could have important implications for the reduction of surfactant protein levels in diseases such as ARDS.
Collapse
Affiliation(s)
- Aparajita Das
- Center for Biomedical Research, The University of Texas Health Center at Tyler, 75708-3154, USA
| | | | | | | | | | | | | |
Collapse
|
8
|
Boggaram V, Chandru H, Gottipati KR, Thakur V, Das A, Berhane K. Transcriptional regulation of SP-B gene expression by nitric oxide in H441 lung epithelial cells. Am J Physiol Lung Cell Mol Physiol 2010; 299:L252-62. [PMID: 20418387 PMCID: PMC2928609 DOI: 10.1152/ajplung.00062.2010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Accepted: 04/20/2010] [Indexed: 11/22/2022] Open
Abstract
Surfactant protein B (SP-B) is essential for the surface tension-lowering function of pulmonary surfactant. Surfactant dysfunction and reduced SP-B levels are associated with elevated nitric oxide (NO) in inflammatory lung diseases, such as acute respiratory distress syndrome. We previously found that NO donors decreased SP-B expression in H441 and MLE-12 lung epithelial cells by reducing SP-B promoter activity. In this study, we determined the roles of DNA elements and interacting transcription factors necessary for NO inhibition of SP-B promoter activity in H441 cells. We found that the NO donor diethylenetriamine-nitric oxide adduct (DETA-NO) decreased SP-B promoter thyroid transcription factor 1 (TTF-1), hepatocyte nuclear factor 3 (HNF-3), and Sp1 binding activities but increased activator protein 1 (AP-1) binding activity. DETA-NO decreased TTF-1, but not Sp1, levels, suggesting that reduced TTF-1 expression contributes to reduced TTF-1 binding activity. Lack of effect on Sp1 levels suggested that DETA-NO inhibits Sp1 binding activity per se. Overexpression of Sp1, but not TTF-1, blocked DETA-NO inhibition of SP-B promoter activity. DETA-NO inhibited SP-B promoter induction by exogenous TTF-1 without altering TTF-1 levels. DETA-NO decreased TTF-1 mRNA levels and gene transcription rate, indicating that DETA-NO inhibits TTF-1 expression at the transcriptional level. We conclude that NO inhibits SP-B promoter by decreasing TTF-1, Sp1, and HNF-3 binding activities and increasing AP-1 binding activity. NO inhibits TTF-1 levels and activity to decrease SP-B expression. NO inhibition of SP-B expression could be a mechanism by which surfactant dysfunction occurs in inflammatory lung diseases.
Collapse
Affiliation(s)
- Vijay Boggaram
- Center for Biomedical Research, Univ. of Texas Health Science Center at Tyler, TX 75708-3154, USA.
| | | | | | | | | | | |
Collapse
|
9
|
Cao Y, Vo T, Millien G, Tagne JB, Kotton D, Mason RJ, Williams MC, Ramirez MI. Epigenetic mechanisms modulate thyroid transcription factor 1-mediated transcription of the surfactant protein B gene. J Biol Chem 2009; 285:2152-64. [PMID: 19906647 DOI: 10.1074/jbc.m109.039172] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Epigenetic regulation of transcription plays an important role in cell-specific gene expression by altering chromatin structure and access of transcriptional regulators to DNA binding sites. Surfactant protein B (Sftpb) is a developmentally regulated lung epithelial gene critical for lung function. Thyroid transcription factor 1 (Nkx2-1) regulates Sftpb gene expression in various species. We show that Nkx2-1 binds to the mouse Sftpb (mSftpb) promoter in the lung. In a mouse lung epithelial cell line (MLE-15), Nkx2-1 knockdown reduces Sftpb expression, and mutation of Nkx2-1 cis-elements significantly reduces mSftpb promoter activity. Whether chromatin structure modulates Nkx2-1 regulation of Sftpb transcription is unknown. We found that DNA methylation of the mSftpb promoter inversely correlates with known patterns of Sftpb expression in vivo. The mSftpb promoter activity can be manipulated by altering its cytosine methylation status in vitro. Nkx2-1 activation of the mSftpb promoter is impaired by DNA methylation. The unmethylated Sftpb promoter shows an active chromatin structure enriched in the histone modification H3K4me3 (histone 3-lysine 4 trimethylated). The ATP-dependent chromatin remodeling protein Brg1 is recruited to the Sftpb promoter in Sftpb-expressing, but not in non-expressing tissues and cell lines. Brg1 knockdown in MLE-15 cells greatly decreases H3K4me3 levels at the Sftpb promoter region and expression of the Sftpb gene. Brg1 can be co-immunoprecipitated with Nkx2-1 protein. Last, Nkx2-1 and Brg1 with intact ATPase activity are required for mSftpb promoter activation in vitro. Our findings suggest that DNA methylation and chromatin modifications cooperate with Nkx2-1 to regulate Sftpb gene cell specific expression.
Collapse
Affiliation(s)
- Yuxia Cao
- Pulmonary Center, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 02118, USA.
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Thyroid transcription factor-1 (TTF-1/Nkx2.1/TITF1) gene regulation in the lung. Clin Sci (Lond) 2009; 116:27-35. [PMID: 19037882 DOI: 10.1042/cs20080068] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
TTF-1 [thyroid transcription factor-1; also known as Nkx2.1, T/EBP (thyroid-specific-enhancer-binding protein) or TITF1] is a homeodomain-containing transcription factor essential for the morphogenesis and differentiation of the thyroid, lung and ventral forebrain. TTF-1 controls the expression of select genes in the thyroid, lung and the central nervous system. In the lung, TTF-1 controls the expression of surfactant proteins that are essential for lung stability and lung host defence. Human TTF-1 is encoded by a single gene located on chromosome 14 and is organized into two/three exons and one/two introns. Multiple transcription start sites and alternative splicing produce mRNAs with heterogeneity at the 5' end. The 3' end of the TTF-1 mRNA is characterized by a rather long untranslated region. The amino acid sequences of TTF-1 from human, rat, mouse and other species are very similar, indicating a high degree of sequence conservation. TTF-1 promoter activity is maintained by the combinatorial or co-operative actions of HNF-3 [hepatocyte nuclear factor-3; also known as FOXA (forkhead box A)], Sp (specificity protein) 1, Sp3, GATA-6 and HOXB3 (homeobox B3) transcription factors. There is limited information on the regulation of TTF-1 gene expression by hormones, cytokines and other biological agents. Glucocorticoids, cAMP and TGF-beta (transforming growth factor-beta) have stimulatory effects on TTF-1 expression, whereas TNF-alpha (tumour necrosis factor-alpha) and ceramide have inhibitory effects on TTF-1 DNA-binding activity in lung cells. Haplo-insufficiency of TTF-1 in humans causes hypothyroidism, respiratory dysfunction and recurring pulmonary infections, underlining the importance of optimal TTF-1 levels for the maintenance of thyroid and lung function. Recent studies have implicated TTF-1 as a lineage-specific proto-oncogene for lung cancer.
Collapse
|
11
|
Xu Q, Tam M, Anderson SA. Fate mapping Nkx2.1-lineage cells in the mouse telencephalon. J Comp Neurol 2008; 506:16-29. [PMID: 17990269 DOI: 10.1002/cne.21529] [Citation(s) in RCA: 396] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The homeodomain transcription factor Nkx2.1 is expressed in the pallidal (subcortical) telencephalon, including the medial ganglionic eminence (MGE) and preoptic area. Studies have shown that Nkx2.1 is required for normal patterning of the MGE and for the specification of the parvalbumin (PV)- and somatostatin (SST)-expressing cortical interneurons. To define the contribution of Nkx2.1 lineages to neurons in the mature telencephalon, we have generated transgenic mice carrying the genomic integration of a modified bacterial artificial chromosome (BAC) in which the second exon of Nkx2.1 is replaced by the Cre recombinase. Analysis of these mice has found that they express the Cre recombinase and Cre reporters within Nkx2.1-expressing domains of the brain, thyroid, pituitary, and lung. Telencephalic expression of reporters begins at about embryonic day 10.5. Expression both of Cre and of recombination-based Cre reporters is weaker within the dorsalmost region of the MGE than in other Nkx2.1-expressing regions. In this paper, we present fate-mapping data on Nkx2.1-lineage neurons throughout the telencephalon, including the cerebral cortex, amygdala, olfactory bulb, striatum, globus pallidus, septum, and nucleus basalis.
Collapse
Affiliation(s)
- Qing Xu
- Department of Psychiatry, Weill Medical College of Cornell University, New York, New York 10021, USA.
| | | | | |
Collapse
|
12
|
Zhu NL, Li C, Huang HH, Sebald M, Londhe VA, Heisterkamp N, Warburton D, Bellusci S, Minoo P. TNF-alpha represses transcription of human Bone Morphogenetic Protein-4 in lung epithelial cells. Gene 2007; 393:70-80. [PMID: 17350185 PMCID: PMC1945170 DOI: 10.1016/j.gene.2007.01.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Revised: 01/09/2007] [Accepted: 01/15/2007] [Indexed: 11/20/2022]
Abstract
Bone Morphogenetic Proteins are key signaling molecules in vertebrate development. Little is known about Bmp gene regulation in any organ. In Drosophila, the Bmp gene, dpp is regulated by Dorsal, the invertebrate homologue of Rel-NF-kB. In this study we examined whether TNF-alpha, which activates NF-kB, can regulate Bmp4 gene expression. TNF-alpha reduced Bmp4 mRNA in lung adenocarcinoma A549 cells and repressed transcriptional activity of the human Bmp4 promoter in a dose-dependent manner. Similar repression was observed when the Bmp4 promoter was co-transfected with a p65 (RelA) expression vector in the absence of TNF-alpha treatment, suggesting that RelA mediates the effect of TNF-alpha. In support of this finding, the repressor effect of TNF-alpha on Bmp4 was abrogated by a co-transfected dominant negative mutant of IkB (S32A/S36A). The human Bmp4 promoter contains 3 putative consensus binding sites for NF-kB. Surprisingly, only one of the latter binding sites was capable of binding NF-kB. Repressor effect of NF-kB was not dependent on any of the three binding sites, but localized to a 122 bp fragment which bound both RelA and SP1. SP1 stimulated transcription, whereas increasing doses of RelA opposed this effect. In vivo, TNF-alpha inhibited branching morphogenesis and LacZ gene expression in Bmp4-lacz transgenic lungs. These data support a model in which TNF-alpha-induced RelA interacts with SP1 to bring about transcriptional repression of Bmp4 gene. These findings provide a mechanistic paradigm for interactions between mediators of inflammation and morphogenesis with relevant implications for normal lung development and pathogenesis of disease.
Collapse
Affiliation(s)
- Nian-Ling Zhu
- University of Southern California, Keck School of Medicine, Department of Pediatrics, Division of Neonatal Medicine, Los Angeles, CA 90033
| | - Changgong Li
- University of Southern California, Keck School of Medicine, Department of Pediatrics, Division of Neonatal Medicine, Los Angeles, CA 90033
| | - Hao Hao Huang
- University of Southern California, Keck School of Medicine, Department of Pediatrics, Division of Neonatal Medicine, Los Angeles, CA 90033
| | - Matthew Sebald
- University of Southern California, Keck School of Medicine, Department of Pediatrics, Division of Neonatal Medicine, Los Angeles, CA 90033
| | - Vedang A. Londhe
- David Geffen School of Medicine at UCLA, Department of Pediatrics, Division of Neonatology and Developmental Biology, Los Angeles, CA 90095
| | - Nora Heisterkamp
- The Saban Research Institute of Childrens Hospital Los Angeles, Los Angeles, CA 90027
| | - David Warburton
- The Saban Research Institute of Childrens Hospital Los Angeles, Los Angeles, CA 90027
| | - Saverio Bellusci
- The Saban Research Institute of Childrens Hospital Los Angeles, Los Angeles, CA 90027
| | - Parviz Minoo
- University of Southern California, Keck School of Medicine, Department of Pediatrics, Division of Neonatal Medicine, Los Angeles, CA 90033
| |
Collapse
|
13
|
Das A, Boggaram V. Proteasome dysfunction inhibits surfactant protein gene expression in lung epithelial cells: mechanism of inhibition of SP-B gene expression. Am J Physiol Lung Cell Mol Physiol 2007; 292:L74-84. [PMID: 16905641 DOI: 10.1152/ajplung.00103.2006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Surfactant proteins maintain lung function through their actions to reduce alveolar surface tension and control of innate immune responses in the lung. The ubiquitin proteasome pathway is responsible for the degradation of majority of intracellular proteins in eukaryotic cells, and proteasome dysfunction has been linked to the development of neurodegenerative, cardiac, and other diseases. Proteasome function is impaired in interstitial lung diseases associated with surfactant protein C (SP-C) mutation mapping to the BRICHOS domain located in the proSP-C protein. In this study we determined the effects of proteasome inhibition on surfactant protein expression in H441 and MLE-12 lung epithelial cells to understand the relationship between proteasome dysfunction and surfactant protein gene expression. Proteasome inhibitors lactacystin and MG132 reduced the levels of SP-A, SP-B, and SP-C mRNAs in a concentration-dependent manner in H441 and MLE-12 cells. In H441 cells, lactacystin and MG132 inhibition of SP-B mRNA was associated with similar decreases in SP-B protein, and the inhibition was due to inhibition of gene transcription. Proteasome inhibitors decreased thyroid transcription factor-1 (TTF-1)/Nkx2.1 DNA binding activity, and the reduced TTF-1 DNA binding activity was due to reduced expression levels of TTF-1 protein. These data indicated that the ubiquitin proteasome pathway is essential for the maintenance of surfactant protein gene expression and that disruption of this pathway inhibits surfactant protein gene expression via reduced expression of TTF-1 protein.
Collapse
Affiliation(s)
- Aparajita Das
- Department of Molecular Biology, The University of Texas Health Center at Tyler, 11937 US Highway 271, Tyler, TX 75708-3154, USA
| | | |
Collapse
|
14
|
Mukhopadhyay S, Hoidal JR, Mukherjee TK. Role of TNFalpha in pulmonary pathophysiology. Respir Res 2006; 7:125. [PMID: 17034639 PMCID: PMC1613248 DOI: 10.1186/1465-9921-7-125] [Citation(s) in RCA: 387] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2006] [Accepted: 10/11/2006] [Indexed: 12/21/2022] Open
Abstract
Tumor necrosis factor alpha (TNFα) is the most widely studied pleiotropic cytokine of the TNF superfamily. In pathophysiological conditions, generation of TNFα at high levels leads to the development of inflammatory responses that are hallmarks of many diseases. Of the various pulmonary diseases, TNFα is implicated in asthma, chronic bronchitis (CB), chronic obstructive pulmonary disease (COPD), acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). In addition to its underlying role in the inflammatory events, there is increasing evidence for involvement of TNFα in the cytotoxicity. Thus, pharmacological agents that can either suppress the production of TNFα or block its biological actions may have potential therapeutic value against a wide variety of diseases. Despite some immunological side effects, anti-TNFα therapeutic strategies represent an important breakthrough in the treatment of inflammatory diseases and may have a role in pulmonary diseases characterized by inflammation and cell death.
Collapse
Affiliation(s)
- Srirupa Mukhopadhyay
- Pulmonary Division, Department of Internal Medicine, University of Utah Health Science Center, Salt Lake City, Utah: 84132-4701, USA
| | - John R Hoidal
- Pulmonary Division, Department of Internal Medicine, University of Utah Health Science Center, Salt Lake City, Utah: 84132-4701, USA
| | - Tapan K Mukherjee
- Pulmonary Division, Department of Internal Medicine, University of Utah Health Science Center, Salt Lake City, Utah: 84132-4701, USA
| |
Collapse
|
15
|
Markart P, Schmidt R, Ruppert C, Höres C, Silber RE, Börgermann J, Günther A, Friedrich I. Ischemic and endotoxin pre-conditioning reduce lung reperfusion injury-induced surfactant alterations. J Heart Lung Transplant 2006; 24:1680-9. [PMID: 16210147 DOI: 10.1016/j.healun.2005.01.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2004] [Revised: 12/16/2004] [Accepted: 01/12/2005] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Pulmonary ischemia/reperfusion injury represents a common clinical phenomenon after lung transplantation, pulmonary embolism, and cardiac surgery with extracorporeal circulation. We investigated the influence of ischemic and endotoxin pre-conditioning on gas exchange and surfactant properties in a canine model of ischemia/reperfusion injury. METHODS Twenty-six foxhounds underwent 3 hours of warm ischemia of the left lung, followed by 8 hours of reperfusion. Ischemic pre-conditioning was performed for either 5 minutes (IPC-5) or by 2 10-minute ischemic periods (IPC-10), before ischemia. For endotoxin pre-conditioning, dogs were pre-treated by a daily intravenous application of increasing amounts of endotoxin for 6 days. No pre-conditioning was performed in the controls. Bronchoalveolar lavage was performed before ischemia/reperfusion injury (baseline) and after the 8-hour reperfusion period in the non-injured right and in the reperfused left lung. Bronchoalveolar lavage fluids were analyzed for the phospholipid-protein ratio, the content of large surfactant aggregates, the phospholipid and neutral lipid profile, the surfactant protein (SP) content, and for biophysical activity. RESULTS Severe surfactant alterations were observed in the ischemia/reperfusion-injured left lung, with increased protein concentrations and depressed concentrations of large surface aggregates, SP-B, dipalmitoylated phosphatidylcholine, and phosphatidylglycerol. Endotoxin pre-conditioning and IPC-5 were both capable of greatly preventing the ischemia/reperfusion injury-related deterioration of surfactant properties. IPC-10 exerted no effects. Endotoxin pre-conditioning and IPC-5, but not IPC-10, also prevented loss of gas exchange. CONCLUSIONS Ischemic and endotoxin pre-conditioning may protect against impairment of gas exchange in ischemia/reperfusion injury by restoring physiological surfactant properties.
Collapse
Affiliation(s)
- Philipp Markart
- Department of Internal Medicine, Med. Klinik II, Justus-Liebig University, Giessen, Germany
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Sparkman L, Chandru H, Boggaram V. Ceramide decreases surfactant protein B gene expression via downregulation of TTF-1 DNA binding activity. Am J Physiol Lung Cell Mol Physiol 2005; 290:L351-8. [PMID: 16183668 DOI: 10.1152/ajplung.00275.2005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ceramide, a sphingolipid, is an important signaling molecule in the inflammatory response. Mediators of acute lung injury such as TNF-alpha, platelet-activating factor, and Fas/Apo ligand stimulate sphingomyelin hydrolysis to increase intracellular ceramide levels. Surfactant protein B (SP-B), a hydrophobic protein of pulmonary surfactant, is essential for surfactant function and lung stability. In this study we investigated the effects of ceramide on SP-B gene expression in H441 lung epithelial cells. Ceramide decreased SP-B mRNA levels in control and dexamethasone-treated cells after 24-h incubation and inhibition of SP-B mRNA was associated with inhibition of immunoreactive SP-B. In transient transfections assays, ceramide inhibited SP-B promoter activity, indicating that the inhibitory effects are exerted at the transcriptional level. Deletion mapping experiments showed that the ceramide-responsive region is located within the -233/-80-bp region of human SP-B promoter. Electrophoretic mobility shift and reporter assays showed that ceramide reduced the DNA binding activity and transactivation capability of thyroid transcription factor 1 (TTF-1/Nkx2.1), a key factor for SP-B promoter activity. Collectively these data showed that ceramide inhibits SP-B gene expression by reducing the DNA biding activity of TTF-1/Nkx2.1 transcription factor. Protein kinase C inhibitor bisindolylmaleimide and the protein tyrosine kinase inhibitor genistein partially reversed ceramide inhibition, indicating that protein kinases play important roles in the ceramide inhibition of SP-B gene expression. Chemical inhibitors of de novo ceramide synthesis and sphingomyelin hydrolysis had no effect on TNF-alpha inhibition of SP-B promoter activity and mRNA levels, suggesting that ceramide does not play a role in the inhibition.
Collapse
Affiliation(s)
- Loretta Sparkman
- Dept. of Molecular Biology, University of Texas Health Center at Tyler, TX 75708-3154, USA
| | | | | |
Collapse
|
17
|
Salinas D, Sparkman L, Berhane K, Boggaram V. Nitric oxide inhibits surfactant protein B gene expression in lung epithelial cells. Am J Physiol Lung Cell Mol Physiol 2003; 285:L1153-65. [PMID: 12896877 DOI: 10.1152/ajplung.00084.2003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Surfactant protein B (SP-B) is an essential constituent of pulmonary surfactant. In a number of inflammatory diseases of the lung, elevated nitric oxide (NO) levels are associated with decreased SP-B levels, suggesting that reduced SP-B levels contribute to lung injury. In this study, we investigated the effects of NO on SP-B gene expression in H441 and MLE-12 cells, cell lines with characteristics of bronchiolar (Clara) and alveolar type II epithelial cells, respectively. Results show that NO donors decreased SP-B mRNA levels in a concentration- and time-dependent manner in H441 and MLE-12 cells. The NO donors also antagonized dexamethasone induction of SP-B mRNA in H441 cells. NO donor inhibition of SP-B mRNA was blocked by the transcriptional inhibitor 5,6-dichloro-1-beta-D-ribofuranozyl-benzimidazole. NO donors decreased luciferase expression from a reporter plasmid containing -911/+41 bp of human SP-B 5'-flanking DNA in H441 and MLE-12 cells, indicating inhibitory effects on SP-B promoter activity. NO inhibition of SP-B mRNA levels was not blocked by LY-83583 and KT-5823, inhibitors of soluble guanylate cyclase and protein kinase G, respectively. Furthermore, cell-permeable cGMP analog 8-bromo-cGMP had no effect on SP-B mRNA levels. These data indicate that elevated NO levels negatively regulate SP-B gene expression by inhibiting gene transcription and that NO inhibits SP-B gene expression independently of cGMP levels. These data imply that reduced SP-B expression due to elevated NO levels can contribute to lung injury.
Collapse
Affiliation(s)
- Darrell Salinas
- Department of Molecular Biology, University of Texas Health Center at Tyler, Tyler, Texas 75708-3154, USA
| | | | | | | |
Collapse
|
18
|
Haczku A, Atochina EN, Tomer Y, Cao Y, Campbell C, Scanlon ST, Russo SJ, Enhorning G, Beers MF. The late asthmatic response is linked with increased surface tension and reduced surfactant protein B in mice. Am J Physiol Lung Cell Mol Physiol 2002; 283:L755-65. [PMID: 12225952 DOI: 10.1152/ajplung.00062.2002] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pulmonary surfactant dysfunction may significantly contribute to small airway obstruction during the asthmatic response, but neither its exact role nor its regulation is clear. Surfactant function and composition was studied in an Aspergillus fumigatus (Af)-induced late-phase allergic airway response in sensitized BALB/c mice. The peak of Af-induced airway hyperresponsiveness in sensitized and challenged mice 24 h after allergen provocation coincided with a significant fall in surface activity of the pulmonary surfactant. The underlying changes included time-dependent elaboration of eotaxin and IL-5 followed by eosinophil influx into the airways. The height of airway inflammation and hyperresponsiveness was preceded by release of IL-4 and marked reductions in surfactant protein (SP)-B, a hydrophobic surfactant protein responsible for maintaining low surface tension of the lining fluid of distal air spaces. Furthermore, intratracheal administration of IL-4 significantly inhibited SP-B, indicating a regulatory role of this cytokine in the surfactant biophysical changes. Thus surfactant dysfunction induced by an IL-4-driven SP-B deficiency after allergen provocation may be an important part of the late asthmatic airway response.
Collapse
Affiliation(s)
- Angela Haczku
- Pulmonary, Allergy and Critical Care Division, Department of Medicine, University of Pennsylvania Medical School, Philadelphia 19104, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Strayer M, Savani RC, Gonzales LW, Zaman A, Cui Z, Veszelovszky E, Wood E, Ho YS, Ballard PL. Human surfactant protein B promoter in transgenic mice: temporal, spatial, and stimulus-responsive regulation. Am J Physiol Lung Cell Mol Physiol 2002; 282:L394-404. [PMID: 11839532 DOI: 10.1152/ajplung.00188.2001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Surfactant protein B (SP-B) is a developmentally and hormonally regulated lung protein that is required for normal surfactant function. We generated transgenic mice carrying the human SP-B promoter (-1,039/+431 bp) linked to chloramphenicol acetyltransferase (CAT). CAT activity was high in lung and immunoreactive protein localized to alveolar type II and bronchiolar epithelial cells. In addition, thyroid, trachea, and intestine demonstrated CAT activity, and each of these tissues also expressed low levels of SP-B mRNA. Developmental expression of CAT activity and SP-B mRNA in fetal lung were similar and both increased during explant culture. SP-B mRNA but not CAT activity decreased during culture of adult lung, and both were reduced by transforming growth factor (TGF)-beta(1). Treatment of adult mice with intratracheal bleomycin caused similar time-dependent decreases in lung SP-B mRNA and CAT activity. These findings indicate that the human SP-B promoter fragment directs tissue- and lung cell-specific transgene expression and contains cis-acting elements involved in regulated expression during development, fetal lung explant culture, and responsiveness to TGF-beta and bleomycin-induced lung injury.
Collapse
Affiliation(s)
- Marlene Strayer
- Division of Neonatology, Department of Pediatrics, The Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Harrod KS, Jaramillo RJ. Pseudomonas aeruginosa and tumor necrosis factor-alpha attenuate Clara cell secretory protein promoter function. Am J Respir Cell Mol Biol 2002; 26:216-23. [PMID: 11804873 DOI: 10.1165/ajrcmb.26.2.4718] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The Clara cell secretory protein (CCSP, also CC-10/uterglobin) is a 16-kD homodimeric protein abundantly expressed in the airways of mammals. Although the molecular function is unknown, gene-targeting studies indicate CCSP as a regulator of lung inflammation following acute respiratory infection or injury. CCSP is decreased in the lungs of mice following acute Pseudomonas aeruginosa (P.a.) infection. In the present study, the role of decreased promoter function in the regulation of CCSP by P.a. was assessed using an in vitro co-culture system and in vivo studies of transgenic mice. CCSP promoter activity in lung epithelial cells was markedly decreased by P.a. or tumor necrosis factor-alpha (TNF-alpha) in a dose-dependent manner. Regulation of CCSP promoter function by either P.a. or TNF-alpha was localized to the proximal 166 bp flanking region of the CCSP promoter activity. Decreased regulation of the CCSP promoter by P.a. or TNF-alpha was specific to CCSP, as human surfactant protein D (SP-D) promoter activity was unaffected or increased by P.a. or TNF-alpha, respectively. A neutralizing antibody against human TNF-alpha was able to reverse both the TNF-alpha- mediated as well as P.a.-mediated decrease in CCSP promoter function in lung epithelial cells. TNF-alpha secretion by lung epithelial cells coincided with the decrease in CCSP promoter function following P.a. administration. Using a transgenic mouse model, P.a. administration to the lung markedly attenuated CCSP promoter-conferred gene expression in vivo. The attenuation of CCSP promoter activity in lung epithelial cells by P.a. involves, in part, autocrine/paracrine secretion of TNF-alpha, which in turn regulates CCSP transcription through cis-active elements in the proximal promoter region.
Collapse
Affiliation(s)
- Kevin S Harrod
- Asthma and Pulmonary Immunology Program, Lovelace Respiratory Research Institute, 2425 Ridgecrest Drive SE, Albuquerque, New Mexico 87108, USA.
| | | |
Collapse
|
21
|
Berhane K, Boggaram V. Identification of a novel DNA regulatory element in the rabbit surfactant protein B (SP-B) promoter that is a target for ATF/CREB and AP-1 transcription factors. Gene 2001; 268:141-51. [PMID: 11368910 DOI: 10.1016/s0378-1119(01)00417-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Surfactant protein B (SP-B) is required for the maintenance of biophysical properties and physiological function of pulmonary surfactant. SP-B is expressed in a cell/tissue-specific manner by the alveolar type II and bronchiolar (Clara) epithelial cells of the lung and is developmentally and hormonally regulated. We previously identified a minimal promoter region containing -236/+39 base pairs (bp) of rabbit SP-B gene that is necessary and sufficient for high level promoter activity in NCI-H441 cells, a cell line with characteristics of Clara cells. In this study, we have characterized the functional importance of a novel DNA regulatory element, termed SP-B CRE, with the sequence TGAGGTCA in the SP-B minimal promoter. The SP-B CRE sequence shared homology to cyclic AMP responsive element (CRE) binding sequence and contained an overlapping nuclear receptor element binding half-site. Mutation of SP-B CRE into a scrambled sequence reduced promoter activity by greater than 70%, whereas mutation into a palindromic consensus CRE increased the promoter activity by 100%. Electrophoretic mobility shift assay (EMSA) and Western immunoblot analysis of affinity purified proteins interacting with SP-B CRE showed that it is a target for binding of members of the activating transcription factor (ATF)/cyclic AMP response element binding protein (CREB) family of transcription factors, such as CREB, CREM, ATF-1, ATF-2 as well as c-Jun and TTF-1. Overexpression of CREB, ATF-2 and c-Jun inhibited SP-B promoter activity in NCI-H441 cells. These data have shown that members of the ATF/CREB family of transcription factors and c-Jun play important roles in mediating the transcriptional regulation of the SP-B gene.
Collapse
Affiliation(s)
- K Berhane
- Department of Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, TX 75708-3154, USA
| | | |
Collapse
|
22
|
Haczku A, Atochina EN, Tomer Y, Chen H, Scanlon ST, Russo S, Xu J, Panettieri RA, Beers MF. Aspergillus fumigatus-induced allergic airway inflammation alters surfactant homeostasis and lung function in BALB/c mice. Am J Respir Cell Mol Biol 2001; 25:45-50. [PMID: 11472974 DOI: 10.1165/ajrcmb.25.1.4391] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The differential regulation of pulmonary surfactant proteins (SPs) is demonstrated in a murine model of Aspergillus fumigatus (Af )-induced allergic airway inflammation and hyperresponsiveness. BALB/c mice were sensitized intraperitoneally and challenged intranasally with Af extract. Enzyme-linked immunosorbent assay analysis of serum immunoglobulin (Ig) levels in these mice showed markedly increased total IgE and Af-specific IgE and IgG1. This was associated with peribronchial/perivascular tissue inflammation, airway eosinophilia, and secretion of interleukin (IL)-4 and IL-5 into the bronchoalveolar lavage fluid (BALF). Functional analysis revealed that in comparison with nonsensitized mice, allergic sensitization and challenge resulted in significant increases in acetylcholine responsiveness. To analyze levels of SPs, the cell-free supernate of the BALF was further fractionated by high-speed (20,000 x g) centrifugation. After sensitization and challenges, the pellet (large-aggregate fraction) showed a selective downregulation of hydrophobic SPs SP-B and SP-C by 50%. This reduction was reflected by commensurate decreases in SP-B and SP-C messenger RNA (mRNA) expression of the lung tissue of these animals. In contrast, there was a 9-fold increase in SP-D protein levels in the 20,000 x g supernate without changes in SP-D mRNA. The increased levels of SP-D showed a significant positive correlation with serum IgE (r = 0.85, P < 0.001). Tissue mRNA and protein levels of SP-A in either the large- or the small-aggregate fractions were unaffected. Our data indicate that allergic airway inflammation induces selective inhibition of hydrophobic SP synthesis accompanied by marked increases in the lung collectin SP-D protein content of BALF. These changes may contribute significantly to the pathophysiology of Af-induced allergic airway hyperresponsiveness.
Collapse
Affiliation(s)
- A Haczku
- Pulmonary, Allergy and Critical Care Division, Department of Medicine, University of Pennsylvania School of Medicine, 421 Curie Blvd., Philadelphia, PA 19104, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|