Bovine Retinal Pericytes Are Resistant to Glucose-Induced Oxidative StressIn Vitro

Abstract

Diabetic retinopathy is a sight-threatening complication of diabetes, and loss of pericytes represents early signs of its development. We tested the hypothesis that high glucose levels may induce signs of oxidative stress in cultured bovine retinal pericytes. Pericytes were exposed to either normal (5.5 mM) or high (22 mM) glucose levels for 1, 3, and 5 days. Signs of oxidative stress were measured by expression of copper/zinc superoxide dismutase, manganese superoxide dismutase, catalase, and glutathione peroxidase using real-time RTPCR. To elucidate the role of oxidative stress, we also measured glutathione (GSH) concentration in the cells and investigated the impact of thiol-reactive metal ions and hydrogen peroxide (H(2)O(2)) on intracellular GSH. Despite the stimulation with high glucose, thiol-reactive metal ions, or H(2)O(2), there was no clear increased expression of antioxidant enzymes or influence of GSH levels. Lipid peroxidation (malondialdehyde level) was increased in bovine aortic smooth muscle cells, but not in bovine retinal pericytes. The data indicate that pericytes do not develop oxidative stress in response to hyperglycemia. However, it is not definitively excluded that oxidative stress may occur after longer time periods of glucose stimulation.

NADPH OxidaseversusMitochondria-Derived ROS in Glucose-Induced Apoptosis of Pericytes in Early Diabetic Retinopathy

“…Our findings of increased oxidative stress in response to high glucose is in line with some previous studies [20, 23], but it appears to argue against a recent report suggesting that pericytes are resistant to glucose-induced oxidative stress [35]. The reason for this inconsistency is at present unclear.…”

Isolation, Purification, and Cultivation of Primary Retinal Microvascular Pericytes: A Novel Model Using Rats

“…However, this source is limited as well and is inconvenient to obtain since bovine eyes are provided by slaughterhouses. Moreover, bovine animal models have not been used to study diabetes mellitus (DM), and some data derived from bovine RMPs are not in accord with those derived from human RMPs under the conditions that mimic DM .…”

Different apoptotic responses of human and bovine pericytes to fluctuating glucose levels and protective role of thiamine

“…On the other hand, it has been suggested that bovine cells can behave differently from human ones, when cultured in experimental conditions which mimic the diabetic microenvironment [14,15].…”

“…The pathophysiological role of pericytes in the onset of diabetic retinopathy has been studied, so far, by using in vitro primary bovine or rat cells, but it has been suggested that human and bovine retinal pericytes can behave differently when cultured in high ambient glucose [14,15]. We have recently established and characterized a human retinal pericyte (HRP) line, named Bmi-HRP, with similar phenotype and function as the wild-type human retinal pericytes (WT-HRP) from which it was derived [16].…”