Research status of retinal cell death in diabetic retinopathy

Programmed cell death is an important defense mechanism of the body, which monitors internal lesions and defends external infections to maintain the stability of the body.In the past, there were two main types of cell death: apoptosis and necrosis.With the development of scientific research, new cell death modes, such as pyroptosis and ferroptosis, have attracted much attention and are involved in the occurrence and development of diabetic retinopathy (DR).Many pathogenic factors, such as oxidative stress, hyperglycemia and inflammation, lead to the death of retinal cells in different ways, such as apoptosis, pyroptosis and ferroptosis.Apoptosis is the earliest pathological response of DR, which occurs at the initial stage of oxidative stress, and the integrity of cell membranes is maintained at the early stage of apoptosis.Apoptotic cells are cleared by phagocytes in the tissue before dissolution, which avoids unnecessary inflammation.Pyroptosis is activated by Caspase-1, then cleaves GSDMD, which can lead to pore formation and osmotic cell lysis, resulting in inflammation and immune response.Ferroptosis involves lipid peroxidation and abnormal iron homeostasis.Lipid peroxidation and glutathione depletion are the main markers of ferroptosis.The three cell death modes are independent and interrelated, and play a role in the occurrence and development of diseases together with other cell death modes.This article reviews the current status of cell apoptosis, pyroptosis and ferroptosis in DR.