Activation of p38 MAPK and expression of TGF-ß1 in rat colon enterocytes after whole body γ-irradiation.
Int J Radiat Biol
; 88(4): 348-58, 2012 Apr.
Article
in En
| MEDLINE
| ID: mdl-22233094
ABSTRACT
PURPOSE:
To examine the p38 mitogen-activated protein kinase (p38) phosphorylation and transforming growth factor beta 1 (TGF-ß1) expression in rat colon enterocytes after irradiation and their contribution to pathology of intestinal radiation disease. MATERIALS ANDMETHODS:
Male Wistar rats were irradiated with whole body γ-radiation of 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 Gy ((60)Co, 1.44 Gy.min(-1)). Samples were taken 4 and 24 h after irradiation, immunohistochemically stained, then p38 phosphorylation and TGF-ß1 expression were measured in apical and cryptal enterocytes using computer image analysis. In selected groups, morphometric parameters, mitosis and apoptosis were evaluated.RESULTS:
P38 phosphorylation integrated optical density (IOD)-based levels increased 2.4-fold (p ≤ 0.01) and 3.6 to 22.8-fold (p ≤ 0.001) in apical enterocytes 4 h after 0.5 Gy and 24 h after 3-10 Gy, respectively. TGF-ß1 IOD-based expression increased 3.3- to 6.9-fold (p ≤ 0.001) and 1.6- to 4.9-fold (p ≤ 0.001) in apical cells 4 h after 0.5-2, 4, 5 Gy and 24 h after 6-10 Gy, respectively. No changes were observed in crypts.CONCLUSIONS:
We found a chronological and dose-dependent order of p38 activation and TGF-ß1 expression in apical enterocytes. Transient up-regulation of p38 and TGF-ß1 signalling observed 4 h after low-dose irradiation may participate in molecular mechanisms creating cellular over-expression in apical compartment, while persistent patterns measured 24 h after high-dose irradiation might provide protection of remaining cells in order to maintain tissue integrity.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Gene Expression Regulation
/
Whole-Body Irradiation
/
Colon
/
Enterocytes
/
P38 Mitogen-Activated Protein Kinases
/
Gamma Rays
Limits:
Animals
Language:
En
Journal:
Int J Radiat Biol
Journal subject:
RADIOLOGIA
Year:
2012
Document type:
Article
Affiliation country:
Czech Republic