Intervention of basic fibroblast growth factor on apoptosis of retinal nerve cells and expression of regulatory genes in rats after retinal ischemic reperfusion

ABSTRACT

BACKGROUND:

Basic fibroblast growth factor (bFGF), a kind of polypeptide growth factor possessing multifunctional biological activities,can protect neurons and promote the growth of nerves. It has been corfirmed that bFGF has therapeutic effects on retina ischemia/reperfusion injury (RIRI).

To establish RIRI model and analyze the effects of bFGF on cellular apoptosis of retina and the expression of regulatory gene protein.

Randomized grouping and validating trial.

Department of Ophthalmology, the Affiliated Hospital of Medical College of Qingdao University.MATERIALS The experiment was conducted at the Research Laboratory of Pathology, Department of Ophthalmology, Medical College of Qingdao University, from April 2002 to December 2003. Twenty-eight healthy Wistar rats were enrolled in this experiment. Four rats were randomly chosen for normal control group, the left eyes of the other 24 rats were set as normal saline control group, and the right eyes were set as bFGF group.

Normal saline control group and bFGF group adopted the rat RIRI models established by transiently elevating intraocular pressure. Normal saline of 12 μL was injected into the vitreous cavity of the left eyes of the rats in normal control group. 12 μL bFGF was injected into the vitreous cavity of the right eyes of the rats in bFGF group, 4 rats once. No administration was given in normal control group. The expression of apoptotic cells was detected and apoptosis indexes were calculated with the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) method and immunohistochemical staining method at the 1st, 6th,12th, 24th,48th and 72nd hours after reperfusion and ischemia for 1 hour.MAIN OUTCOME

① The detection results of apoptotic cells in situ of retina tissuesat different time points after reperfusion. ②The expression of Fas and caspases-2 in retina tissues at different time points after reperfusion.RESULTS ① Comparison of apoptosis indexes of retina tissues at different time points after ischemia reperfusion There were no apoptotic cells in the retina tissues of the rats in normal control group. As compared with those in normal saline control group, apoptosis indexes in bFGF group were significantly decreased at ischemia 1 hour and reperfusion 1, 6, 12, 24, 48and 72 hours, especially at the 12th, 24th and 48th hours after reperfusion (t =5.362-5.595, P ＜ 0.05). ② The change of Fas expression at different time points after ischemia reperfusion There was hardly any Fas expression in normal control group. As compared with that in normal saline control group, Fas expression in bFGF group was significantlydecreased at ischemia 1 hour and reperfusion 1, 6, 12, 24, 48 and 72 hours, especially at the 6th, 12th and 24th hours after reperfusion (t=3.954-9.327, P ＜ 0.05). ③The changes of caspase-2 expression at different time points after ischemia reperfusion There was no caspase-2 expression in normal control group.Compared with that in normal saline control group, the number of caspase2 positive cells in bFGF group was significantly decreased at the 6th,12th,24th, 48th and 72nd hours after ischemia for 1 hour and reperfusion (t=4.125-15.641, P ＜ 0.05).

bFGF can significantly inhibit the expression of apoptosis gene Fas and caspase-2 in the ischemia and reperfusion of retina, thus reducing cellular apoptosis of ganglion cells and exerting therapeutic effects on the ischemia and reperfusion of retina.