Immunogenic self-DNA drives neuropsychiatric systemic lupus erythematosus in conventional genetic background mice

Neuropsychiatric systemic lupus erythematosus (NPSLE) represents a significant and growing challenge in both clinical practice and research, with its mechanistic investigation hindered by the lack of reliable animal models. Over the past two decades, we have established that immunogenic self-DNA can induce SLE disease model, which has been widely utilized in the academic community. To modify the doses of immunogenic self-DNA, validate the induction of SLE disease, and systematically characterize the resulting neuropsychiatric manifestations, aiming to provide an optimal model for NPSLE. Conventional genetic background BALB/c mice were immunized with 75 µg of immunogenic self-DNA. Based on the criteria and diagnostic recommendations from the ACR and EULAR, we conducted neurobehavioral experiments to assess the neuropsychiatric manifestations of clinical NPSLE patients. Whole-cell patch-clamp electrophysiological recordings were performed on mouse brain slices to assess electroencephalographic (EEG) abnormalities associated with NPSLE. Cerebrospinal fluid (CSF) abnormalities were evaluated by measuring inflammatory factors in the CSF. Additionally, histopathological analyses were conducted to evaluate MRI abnormalities in self-DNA immunized mice. Self-DNA immunized mice developed progressive cognitive impairments, exhibiting spatial and working memory deficits from week 8 post-immunization, which worsened by week 12, alongside the emergence of anxiety-like and depression-like behaviors. In parallel, electrophysiological analysis revealed synaptic transmission deficits and reduced neuronal excitability beginning at week 8, further deteriorating by week 12. Of note, blood-brain barrier (BBB) disruption was observed at 4-8 weeks post immunization, which was evidenced by IgG leakage and FITC-dextran extravasation. Such BBB disruption was accompanied by elevated pro-inflammatory cytokines (IL-1β, IL-6, TNF-α, IL-10), resembling neuropsychiatric lupus pathology. Finally, histologically, hippocampal neuronal loss and dendritic spine reduction in CA1, CA3, and DG subregions were observed, providing structural correlates for the observed memory deficits in self-DNA immunized mice. This model induced by immunogenic self-DNA recapitulated the neurological manifestations observed in clinical patients, rendering it a robust model for the research of NPSLE.