The clinical significance of miR-484 in depression of older people with Alzheimer's disease and its potential role on depressive behavior.

Abstract

Objective: MicroRNAs exhibit remarkable potential as biomarkers due to their multiple advantages in Alzheimer's disease (AD). This study aimed to explore the significance of miR-484 in AD.

Methods: The study included 216 participants [70 healthy controls (HCs), 77 AD with nondepression, 69 AD with depression (AD-D)]. PCR measured serum and tissue miR-484 levels. Receiver operator characteristic curves evaluated miR-484 diagnostic potential for AD/AD-D. Logistic regression identified AD-D risk factors. Bioinformatics predicted miR-484 targets and functional pathways. Dual-luciferase assay validated the interaction between miR-484 and platelet derived growth factor subunit A (PDGFA). Chronic restraint stress (CRS) induced depression animal model by Kunming mice (20 each group × 6 groups). The effect of miR-484/PDGFA axis on depression-like behaviors was evaluated through behavioral tests (sucrose preference, forced swim, and open field).

Results: Serum miR-484 was downregulated in AD and further decreased in AD-D compared with HCs. MiR-484 downregulation diagnosed AD-D from AD. MiR-484 expression was correlated with amyloid β -protein 1-42 ( r  = 0.682), total tau ( r  = -0.575), Mini-Mental State Examination score ( r  = 0.593), and Hamilton depression rating scale score ( r  = -0.709). MiR-484 was a risk factor for depression in AD. In the depression mouse model, miR-484 overexpression ameliorated depression-like behaviors (sucrose preference, forced swim immobility time, locomotor activity) by regulating PDGFA.

Conclusion: Downregulated miR-484 expression, correlating with cognitive function and depression degree, showed a diagnostic value on AD and AD-D. MiR-484 attenuated the CRS-induced depression-like behavior by regulating PDGFA.