The long-term goal of this project is to investigate mechanisms of alternative mRNA splicing of human surfactant protein A (SP-A) and potential implications/effects in the pathogenesis of several pulmonary diseases. Alternative mRNA splicing is a major regulatory mechanism that can generate protein diversity and increase proteome complexity. More than 70% of human genes express multiple mRNA variants through alternative splicing. About 20% of the variability from alternative splicing falls within the untranslated regions (5'UTR and 3'UTR) that affects mRNA stability, translation efficiency, and mRNA localization. SP-A, an important innate immune protein, plays a critical role in the innate host defense and the inflammatory regulation of lung, in surfactant-related physiological functions, and in parturition. In humans, there are two functional genes, SP-A1 and SP-A2. Differential expression of SP-A1 and SP-A2 has been observed in fetal and adult lung, and SP-A1 and SP-A2 genetic variants have been associated with pulmonary diseases including respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), and other lung diseases. The 5'UTR of SP-A1 and SP-A2 generates a number of splice variants, and these 5'UTR variants differentially influence translation efficiency and mRNA stability. Moreover, the ratio of SP-A1 to total SP-A content has been shown to vary as a function of age and lung health status. In this proposal, we hypothesize that differences exist between SP-A1 and SP-A2 in 5'UTR cis-acting elements and in trans-acting factors binding these elements. The rationale is based on the observation that: a) the key difference between the most frequently found SP-A1 (A*D') and SP-A2 (A*BD, A*BD') splice variants is the exclusion and inclusion, respectively, of exon B;b) our preliminary findings have shown that SP-A1 cis-acting element #6, i.e. exon splicing enhancer/silencer (ESE/S # 6), plays a role in splicing, and that specific protein(s) may bind to ESE/S #6. To test this hypothesis, we have proposed two specific aims:
Specific Aim #1 : to examine the functional impact of candidate cis-acting ESE/S elements in the SP-A1 and SP-A2 5'UTR splicing.
Specific Aim #2 : to study trans-acting factors involved in the regulation of SP-A 5'UTR splicing, with a focus on binding proteins associated with the SP-A1-specific cis-acting element ESE/S # 6. Upon completion of this R21 project, a novel experimental model system for alternative splicing of human SP-A can be established, and aspects of candidate cis-acting ESE/S elements within each SP-A gene and of trans-acting factors be analyzed and identified. These could provide foundational methodologies and insight for our further studies (R01 application) of the mechanisms involved in the splicing regulation of human SP-A1 and SP-A2, and of better understanding of the pathogenesis of several lung diseases.

Public Health Relevance

This project is to establish a novel high-throughout experimental system for the study of mechanisms of alternative mRNA splicing of human surfactant proteins (SP-A1 and SP-A2). The proposed experiments include examination of the functional impact of candidate cis-acting ESE/S elements and identification of trans-acting factors binding these elements. New methodologies used and knowledge gained will contribute to the growing field of mRNA splicing regulation and to future studies that can help us to better understand the pathogenesis of several lung diseases.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21HL096007-01A1
Application #
7776643
Study Section
Lung Injury, Repair, and Remodeling Study Section (LIRR)
Program Officer
Lin, Sara
Project Start
2010-01-01
Project End
2011-12-31
Budget Start
2010-01-01
Budget End
2010-12-31
Support Year
1
Fiscal Year
2010
Total Cost
$232,650
Indirect Cost
Name
Pennsylvania State University
Department
Pediatrics
Type
Schools of Medicine
DUNS #
129348186
City
Hershey
State
PA
Country
United States
Zip Code
17033
Zhang, Zhiyong; Abdel-Razek, Osama; Wang, Guirong (2017) A Mouse Model for Ocular Surface Staphylococcus aureus Infection. Curr Protoc Mouse Biol 7:55-63
Ge, Lin; Liu, Xinyu; Chen, Rimei et al. (2016) Differential susceptibility of transgenic mice expressing human surfactant protein B genetic variants to Pseudomonas aeruginosa induced pneumonia. Biochem Biophys Res Commun 469:171-5
Xu, Yongan; Ge, Lin; Abdel-Razek, Osama et al. (2016) DIFFERENTIAL SUSCEPTIBILITY OF HUMAN SP-B GENETIC VARIANTS ON LUNG INJURY CAUSED BY BACTERIAL PNEUMONIA AND THE EFFECT OF A CHEMICALLY MODIFIED CURCUMIN. Shock 45:375-84
Xu, Yongan; Hong, Yucai; Xu, Mengyan et al. (2016) Role of Keratinocyte Growth Factor in the Differentiation of Sweat Gland-Like Cells From Human Umbilical Cord-Derived Mesenchymal Stem Cells. Stem Cells Transl Med 5:106-16
Hu, Fengqi; Ding, Guohua; Zhang, Zhiyong et al. (2016) Innate immunity of surfactant proteins A and D in urinary tract infection with uropathogenic Escherichia coli. Innate Immun 22:9-20
Liu, Zhiyong; Liu, Jiao; Zhao, Kailiang et al. (2016) Role of Daphnetin in Rat Severe Acute Pancreatitis Through the Regulation of TLR4/NF-[Formula: see text]B Signaling Pathway Activation. Am J Chin Med 44:149-63
Zhang, Zhiyong; Abdel-Razek, Osama; Hawgood, Samuel et al. (2015) Protective Role of Surfactant Protein D in Ocular Staphylococcus aureus Infection. PLoS One 10:e0138597
Liu, Jiao; Abdel-Razek, Osama; Liu, Zhiyong et al. (2015) Role of surfactant proteins A and D in sepsis-induced acute kidney injury. Shock 43:31-8
Liu, Zhiyong; Shi, Qiao; Liu, Jiao et al. (2015) Innate Immune Molecule Surfactant Protein D Attenuates Sepsis-induced Acute Pancreatic Injury through Modulating Apoptosis and NF-?B-mediated Inflammation. Sci Rep 5:17798
Yang, Sijie; Abdel-Razek, Osama A; Cheng, Fei et al. (2014) Bicyclic brominated furanones: a new class of quorum sensing modulators that inhibit bacterial biofilm formation. Bioorg Med Chem 22:1313-7

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