Enhanced expression of hepatocyte growth factor in the healing of experimental acute tympanic membrane perforation.
OBJECTIVE
The present study was performed to investigate the expression of hepatocyte (HGF), epidermal (EGF) and vascular endothelial (VEGF) growth factors in the course of healing of experimental tympanic membrane (TM) perforations in rats. The goal was to explain the role of these growth factors in the healing process of TM and to assess the possibility of their future application as healing promoters.


METHODS
Seventy rats were used, of which 10 served as controls and the others had their TM perforated. The experimental animals were divided into six subgroups on the basis of time points (01, 03, 05, 07, 09, 15 day after injury). Videootoscopy and histology were employed to assess the morphology of the healing process. The expressions of HGF, EGF and VEGF were evaluated using Western blot analysis. Tissue localization of HGF was determined by the immunofluorescence method.


RESULTS
HGF was hardly detectable in normal TM; however, a significant increase was noted in its expression starting from the third day after injury throughout the follow-up period, with the highest level on day 05. The analysis of HGF tissue localization with immunofluorescence revealed diffuse staining in the cytoplasm of proliferating epithelial cells. The expression of EGF was elevated on the first day after injury, not reaching statistical significance, and then returned to the level observed in the control TM. No significant differences were noted in the expression of VEGF.


CONCLUSIONS
High expression of HGF during the healing process of acute TM perforations makes it a promising candidate for further studies oriented towards its possible use in augmentation of TM healing.
Department of Otolaryngology, J. Śniadecki District Hospital, M. Skłodowskiej-Curie 26, 15-950 Białystok, Poland.
Maria
M
Makuszewska
Department of General and Experimental Pathology, Medical University of Białystok, Mickiewicza 2c, 15-222 Białystok, Poland.
Magdalena
M
Sokołowska
Department of Pediatric Otolaryngology, Medical University of Białystok, Waszyngtona 17, 15-274 Białystok, Poland. Electronic address: hassmann@umb.edu.pl.
Elżbieta
E
Hassmann-Poznańska
Department of General and Experimental Pathology, Medical University of Białystok, Mickiewicza 2c, 15-222 Białystok, Poland.
Izabela
I
Bialuk
Department of Pediatric Otolaryngology, Medical University of Białystok, Waszyngtona 17, 15-274 Białystok, Poland.
Bożena
B
Skotnicka
Department of General and Experimental Pathology, Medical University of Białystok, Mickiewicza 2c, 15-222 Białystok, Poland.
Tomasz
T
Bonda
Department of Medical Pathomorphology, Medical University of Białystok, Waszyngtona 13, 15-269 Białystok, Poland.
Joanna
J
Reszeć
Department of General and Experimental Pathology, Medical University of Białystok, Mickiewicza 2c, 15-222 Białystok, Poland.
Maria Małgorzata
MM
Winnicka
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D015153:Blotting, Western; D004815:Epidermal Growth Factor / Q000378:metabolism*; D017228:Hepatocyte Growth Factor / Q000378:metabolism*; D008297:Male; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D018058:Tympanic Membrane Perforation / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D014945:Wound Healing / Q000502:physiology*
D015415:Biomarkers; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat; D004815:Epidermal Growth Factor; D017228:Hepatocyte Growth Factor
EGF; HGF; Rats; Tympanic membrane perforation healing; VEGF