The characteristics of elastic fiber assembled with recombinant tropoelastin isoform.
OBJECTIVE
It is known that elastin mRNA is transcribed from a single gene. The variety of tropoelastin isoforms results from multiple alternative splicing of the primary transcript. The purpose of this study was to investigate the characteristics of elastic fiber assembled with tropoelastin isoform, which is full-length human tropoelastin (HTE), exon 26A missing tropoelastin (Delta26A), and exon 32 missing tropoelastin (Delta32).


METHODS
We demonstrated the process of elastic fiber assembly and the existence of elastic fiber resistant to pancreatic elastase with HTE, Delta26A, or Delta32 fiber using an in vitro model of elastic fiber assembly. These elastic fibers were evaluated by immunofluorescent staining, the quantitative analysis of cross-linked amino acids, and semi-quantitative analysis of matrix-associated tropoelastin.


RESULTS
There were no big differences getting into the matrix among these tropoelastins in immunofluorescence microscopy and semi-quantitative analysis. In the comparison with the HTE, the Delta26A and the Delta32 significantly increased and decreased, respectively, the formation of cross-linking amino acids and the binding to scaffold proteins. Furthermore, it was found that it is difficult to degrade the Delta26A assembly with pancreatic elastase as compared with HTE or Delta32 assembly.


CONCLUSIONS
The elastic fiber assembled with the tropoelastin isoforms was characterized using an in vitro model. The present study provides important information regarding the pathology of human diseases including emphysema and atherosclerosis.
Sato
Fumiaki
F
Department of Clinical Chemistry, Hoshi University School of Pharmacy and Pharmaceutical Science, 2-4-41 Ebara, Tokyo, 142-8501, Japan.
Wachi
Hiroshi
H
Starcher
Barry C
BC
Murata
Hayato
H
Amano
Satoshi
S
Tajima
Shingo
S
Seyama
Yoshiyuki
Y
D017398:Alternative Splicing; D000596:Amino Acids / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry; D005091:Exons; D000071837:Fibrillins; D005455:Fluorescent Antibody Technique; D006801:Humans; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism; D010196:Pancreatic Elastase / Q000378:metabolism; D020033:Protein Isoforms; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014333:Tropoelastin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D000596:Amino Acids; D003432:Cross-Linking Reagents; D000071837:Fibrillins; D008840:Microfilament Proteins; D020033:Protein Isoforms; D011994:Recombinant Proteins; D014333:Tropoelastin; D010196:Pancreatic Elastase