epoetin-alfa and Cognitive-Dysfunction

With the aging population, the prevalence and incidence of cerebrovascular disease will continue to rise, as well as the number of individuals with vascular cognitive impairment/dementia (VCID). No specific FDA-approved treatments for VCID exist. Although clinical evidence supports that angiotensin receptor blockers (ARBs) prevent cognitive decline in older adults, whether ARBs have a similar effect on VCID after stroke is unknown. Moreover, these agents reduce BP, which is undesirable in the acute stroke period, so we believe that giving C21 in this acute phase or delaying ARB administration would enable us to achieve the neurovascular benefits without the risk of unintended and potentially dangerous, acute BP lowering.. The aim of our study was to determine the impact of candesartan (ARB) or compound-21 (an angiotensin type 2 receptor--AT2R--agonist) on long-term cognitive function post-stroke, in spontaneously hypertensive rats (SHRs). We hypothesized that AT2R stimulation, either directly with C21, or indirectly by blocking the angiotensin type 1 receptor (AT1R) with candesartan, initiated after stroke, would reduce cognitive impairment. Animals were subjected to a 60-min transient middle cerebral artery occlusion and randomly assigned to either saline/C21 monotherapy, for the full study duration (30 days), or given sequential therapy starting with saline/C21 (7 days) followed by candesartan for the remainder of the study (21 days). Outcome measures included sensorimotor/cognitive-function, amyloid-β determination, and histopathologic analyses.. Treatment with RAS modulators effectively preserved cognitive function, reduced cytotoxicity, and prevented chronic-reactive microgliosis in SHRs, post-stroke. These protective effects were apparent even when treatment was delayed up to 7 days post-stroke and were independent of blood pressure and β-amyloid accumulation.. Collectively, our findings demonstrate that RAS modulators effectively prevent cognitive impairment after stroke, even when treatment is delayed.

Topics: Amyloid beta-Peptides; Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Blood Pressure; Cell Hypoxia; Cells, Cultured; Cognitive Dysfunction; Disease Models, Animal; Double-Blind Method; Endothelial Cells; Epoetin Alfa; Hippocampus; Humans; Infarction, Middle Cerebral Artery; Locomotion; Male; Peptide Fragments; Rats; Rats, Inbred SHR; Renin-Angiotensin System; Sensory Gating; Sulfonamides; Tetrazoles; Thiophenes

Type 2 diabetes mellitus (T2DM) is strongly associated with an increased risk of developing cognitive dysfunction. Numerous studies have indicated that erythropoietin (EPO) has neurotrophic effects. Ferroptosis has been reported to be associated with diabetic cognitive dysfunction. However, the impact of EPO on T2DM-associated cognitive dysfunction and its protective mechanism remain unclear. To evaluate the effects of EPO on diabetes-associated cognitive dysfunction, we constructed a T2DM mouse model and found that EPO not only decreased fasting blood glucose but also ameliorated hippocampal damage in the brain. The Morris water maze test indicated that EPO improved cognitive impairments in diabetic mice. Moreover, a ferroptosis inhibitor improved cognitive dysfunction in mice with T2DM in vivo. Furthermore, a ferroptosis inhibitor, but not other cell death inhibitors, mostly rescued high-glucose damaged PC12 cell viability. EPO had a similar effect as the ferroptosis inhibitor, which increased cell viability in the presence of a ferroptosis inducer. In addition, EPO reduced lipid peroxidation, iron levels, and regulated ferroptosis-related expression of proteins in vivo and in vitro. These findings indicate that EPO ameliorates T2DM-associated cognitive dysfunction, which might be related to decreasing iron overload and inhibiting ferroptosis.

Topics: Animals; Cognitive Dysfunction; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Epoetin Alfa; Erythropoietin; Ferroptosis; Iron Overload; Mice