Abstract
Purpose::
During autoimmune uveitis leukocytes migrate across the blood-retinal-barrier . Leukocyte endothelial interaction is mediated via adhesion molecules such as ICAM-1. Inhibition of ICAM-1 in uveitis has been demonstrated to inhibit leukostasis and transmigration of leukocytes The purpose of this research is to investigate the expression changes of tight junction mRNA (occludin-1, zonula occludens protein-1, claudin-1 and claudin-5) in C57/B6 and ICAM-1 Knock-out mice with and without systemic LPS injection.
Methods::
Autoimmune-uveitis was induced via footpad-injection of LPS. 24h after LPS injection, animals were enucleated and RNA was extracted from the retina. After cDNA generation, real-time-pcr was conducted. The quantification data was evaluated with the thermal cycler software (iCycler iQ; Bio-Rad Laboratories) using the qGene-tool the expression was calculated.
Results::
There was not a significant difference in the expression of the occludin-1 and claudin-5 mRNA in between untreated C57/B6 and ICAM deficient mice. In contrast, the expression of claudin-1 was 25% lower in ICAM deficient mice than in C57/B6. Zonula occludens protein-1 expression is elevated 3.2 fold in ICAM mice. Systemic LPS injection did not alter the expression levels of all analysed mRNA in C57/B6 mice. In ICAM deficient mice claudin-1 is 2.9 and claudin-5 mRNA 3.5 fold higher expressed.
Conclusions::
Inhibiting leukocyte adhesion causes different expression pattern of some of the tight junction mRNA during autoimmune uveitis in ICAM deficient mice. These findings suggest that either migration effects or factors released by leukocytes in the target tissue contribute to consistency of mRNA expression in C57/B6 with LPS injection. There seems to be a signalling pathway controlling the expression of claudin-1 and zonula occludens protein-1 mRNA. It depends on the presence of ICAM-1 on retinal endothelial cells.
Keywords: cell adhesions/cell junctions • uveitis-clinical/animal model • gene/expression