The development of Alzheimer disease (AD) involves a cluster of pathogenic processes, including amyloid-beta (Aβ) deposition, tau-mediated neurodegeneration, chronic neuroinflammation, oxidative stress (OS), metabolic dysregulation, and disruption of circadian rhythms. Nuclear hormone receptor, Retinoic Acid-Related Orphan Receptor Alpha (RORα) was shown to regulate multiple neuroprotective pathways such as inflammatory signaling (NF-κB suppression), mitochondrial integrity and mitophagy, redox homeostasis [upregulation of glutathione peroxidase 1 (GPX1), and mitochondrial superoxide dismutase 2, (SOD2)], calcium-dependent synaptic architecture [inositol 1,4,5-trisphosphate receptor type 1 (ITPR1), Purkinje cell protein 4 (PCP4)], and circadian rhythm stability [period 2 (PER2), brain and muscle ARNT-like 1 (BMAL1)]. Multi-omics network analyses place RORα within regulatory networks that are co-associated with key AD-related genes and supports an associational, network-based relationship for RORA. Preclinical gene-augmentation studies using adeno-associated viral vectors report that RORα overexpression reduces APP levels, remodels the complement regulator CD59 glycoprotein (CD59), inhibits OS, and enhances neuronal survival, although these effects were established largely in retinal and other non-AD systems. These findings support the potential of RORA as a therapeutic target through genetic intervention, but direct demonstration of AD-modifying efficacy in-vivo is still lacking. Investigational RORA-focused gene therapy in retinal degenerative diseases provides proof-of-concept for, but does not yet establish, applicability within the central nervous system. Taken together, this evidence nominates RORA as a candidate system-level regulator that may help restore disrupted homeostatic transcriptional networks in AD, a hypothesis that remains to be tested. We propose that RORα functions as a transcriptional hub coupling three homeostatic axes that fail in AD; the circadian, mitochondrial-metabolic, and immune-inflammatory axes, and that its regional expression changes in AD (hippocampal up-regulation vs. suprachiasmatic down-regulation) represent a compensatory response that ultimately fails. Cell-type-specific expression profiling is required to determine in which regions augmentation may be therapeutically appropriate. Restoring RORα is therefore could be network-stabilizing rather than single-pathway intervention.
