Abstract
Purpose:
We investigated the expression of serum amyloid A (SAA) in the eyes with diabetic retinopathy. We searched for the effects of high glucose and hypoxia on the expression of SAA in RF/6A cells in vitro, and for the effects of exogenous SAA on the proliferation, migration and apoptosis of RF/6A cells.
Methods:
A total of 26 eyes of 26 patients with DR, and 10 eyes of 10 patients with non-diabetic ocular disease were enrolled. Multiplex bead assay was used to examine the serum amyloid A level in aqueous humor.Localization of SAA was detected using immunofluorescence. The mRNA and protein of SAA in the RF/6A cells were measured using real-time PCR and western blot. CCK-8 assay was performed to examine the proliferative ability, transwell chamber assay and Annexin/PI staining were used to detect cell migration and apoptosis.
Results:
Significantly higher concentrations of SAA were found in the aqueous humor of DR patients than those in the aqueous humor of the control patients (p<0.01). Immunofluorescence analysis showed SAA were expressed in RF/6A cells in vitro. The expression of SAA mRNA and protein were increased induced by hypoxia and high concentration glucose (p<0.01). By CCK-8 assay, after 24h, the values were significant different with those of control groups either (p<0.01). Results of apoptosis confirmed the apoptosis rates of cells exposed to SAA for 24h were higher than those exposed to its control.
Conclusions:
The expression of SAA was higher in DR patients. SAA was unregulated by high glucose concentration and hypoxia, which promoted cell proliferation, migration and inhibited apoptosis.
Keywords: 499 diabetic retinopathy