The Adenosinergic System in Diabetic Retinopathy

Abstract

The neurodegenerative and inflammatory environment that is prevalent in the diabetic eye is a key player in the development and progression of diabetic retinopathy. The adenosinergic system is widely regarded as a significant modulator of neurotransmission and the inflammatory response, through the actions of the four types of adenosine receptors (A1R, A2AR, A2BR, and A3R), and thus could be revealed as a potential player in the events unfolding in the early stages of diabetic retinopathy. Herein, we review the studies that explore the impact of diabetic conditions on the retinal adenosinergic system, as well as the role of the said system in ameliorating or exacerbating those conditions. The experimental results described suggest that this system is heavily affected by diabetic conditions and that the modulation of its components could reveal potential therapeutic targets for the treatment of diabetic retinopathy, particularly in the early stages of the disease.

Physiological assessment of high glucose neurotoxicity in mouse and rat retinal explants

“…However, the reported effects of diabetic conditions on purinergic receptor expression in different tissues are multiple and complex. An alteration in purinergic receptor subtype expression patterns has been observed in diabetes in the retina and other tissues (Ho et al, ; Kneer, Green, Meyer, Rich, & Minns, ; Mankus, Rich, Minns, & Trinkaus‐randall, ; Seref‐ferlengez, Maung, Schaffler, & Spray, ; Vindeirinho, Santiago, Cavadas, Ambrósio, & Santos, ). For example, in diabetic animals, an increase in levels of P2X 7 R has been reported in corneal epithelium (Kneer et al, ; Mankus et al, ), although a decrease in the expression of these receptors also was shown in osteocytes under HG conditions (Seref‐ferlengez et al, ).…”

Effects of Silymarin on Diabetes Mellitus Complications: A Review

“…Retinopathy is one of the most common complications associated with diabetes and one of the major causes of adult blindness (International Diabetes Federation, ). The mechanisms that are involved in this condition include damaged retinal vasculature, neurodegeneration, and inflammation (Jonsson et al ., ; Vindeirinho et al ., ). Ocular imaging techniques are very important for diagnosis and the evaluation of treatment efficacy (Tan et al ., ).…”

Purinergic Signalling: Therapeutic Developments

“…Several reviews about purinergic signalling in diabetes and its therapeutic potential are available ( Burnstock and Novak, 2013 ; Cieslak and Roszek, 2014 ; Antonioli et al, 2015 ; Fotino et al, 2015 ; Kishore et al, 2015 ; Merighi et al, 2015 ; Vindeirinho et al, 2016 ). The involvement of purinergic signalling in diabetic nephropathy is discussed later in the Section on Kidney.…”