Activity and expression of aldehyde dehydrogenases in the ocular tissue of diabetic rats / 中华实验眼科杂志

ABSTRACT

Background Diabetic complication is associated with lipid peroxidation.Aldehyde dehydrogenases (ALDH) catalyze the irreversible oxidation of a variety of biological aldehydes,including lipid-derived aldehydes (LDAs),and thus protect organs and tissues from toxic LDAs.Understanding the activity of ALDH in different ocular tissues in diabetic subjects is very important for prevention and treatment of diabetic ocular complications.Objective This research aimed to investigate the activity and expression of ALDH in different ocular tissues in diabetic rats and to explore the mechanism of ALDH in diabetes-induced eye disease.Methods Twenty-eight healthy SPF male Sprague-Dawley(SD) rats weighted 170-180 g were randomly divided into the normal control group and diabetic group.The diabetic animal model was established by intraperitonial injection of 4％ streptozotocin at 65 mg/kg.Isometric citric acid buffer was injected in the rats of the normal control group.The rats were sacrificed in each group 2 and 4 months after the establishment of the diabetic models,and eyeballs were obtained for the preparation of corneal,lens and retinal homogenates.ALDH activity was detected using a multifunctional microplate reader SpectraMax M5,and ALDH content was measured by ELISA at the wavelength of 450 nm with the SpectraMax M5 ELISA reader.Results The blood glucose level in diabetic rats was significantly elevated at various time points compared with the normal control group(P=0.000),and body weights were evidently lower in the diabetic group than in the normal group (P =0.000).The activities of ALDH (A340) in corneal,lens and retinal tissues in the diabetic group were increased in comparison with the normal control group (F =396.601,P=0.000),and showed an enhancement with the lapsing of time (F =53.139,P =0.000).In addition,the highest level of ALDH was found in the cornea and the lowest level in the lens(F =6973.000,P=0.000).The expression level of ALDH in the corneal,lens and retinal homogenates was significantly higher in the diabetic group compared with the normal control group (F=312.985,P =0.000) and showed a considerable increase over the course (F =19.203,P=0.000).The highest expression level was seen in the cornea and the lowest was in the lens,with a significant difference among these three kinds of tissues (F =3243.000,P =0.000).Conclusions ALDH can protect ocular tissue from the damage of lipid peroxidation.Thess results suggest that ALDH plays a role in preventing diabetes-related ocular complications.