The association between peripheral inflammation, brain glutamate and antipsychotic response in Schizophrenia: Data from the STRATA collaboration

Urolithin A ameliorates schizophrenia-like behaviors and cognitive impairments in female rats by modulating NLRP3 signaling

The management of cognitive impairments in schizophrenia presents a considerable challenge, with a strong association between neuroinflammation and its progression. Urolithin A (UA) demonstrates important anti-inflammatory properties in multiple neurological disease models, contributing to the enhancement of cognitive deficits. However, it remains uncertain if UA can produce comparable neuroregulatory effects in female rat models of schizophrenia. Eight-week-old female Sprague Dawley rats received either 0.1 mg/kg of MK801 or volume-matched saline via intraperitoneal injection for 5 consecutive days. Furthermore, they were administered 150 mg/kg of UA through oral gavage for 4 weeks. Behavioral assessments were performed to evaluate cognitive function and behavior after UA treatment. Immunofluorescence staining was employed to assess microglial activity in the hippocampus, while Western blot analysis was conducted to investigate the expression of neuroinflammation-associated proteins. Prolonged exposure to MK801 induces schizophrenia-like behaviors and cognitive deficits in female rats. It also elevates the expression of NLRP3, Caspase-1, IL-1β, and IL-18 proteins in the hippocampus, accompanied by the activation of microglial cells. However, UA treatment can reverse the expression of these inflammatory proteins and the activation of microglial cells induced by MK801. This is the first study to evaluate the effects of UA on behavior and cognition in a female rat model of schizophrenia. The findings indicate that UA mitigates MK-801-induced cognitive deficits in female rats by inhibiting neuroinflammation and microglial activation via modulation of the NLRP3 signaling pathway. These findings offer preclinical data endorsing the possible application of UA as a dietary supplement to prevent cognitive deficits in schizophrenia.

Plasma NGAL, not IFN-γ, predicts early treatment response in drug-naïve Chinese Han schizophrenia patients

BACKGROUND

Early prediction of treatment efficacy can assist psychiatrists in optimizing personalized treatment strategies for drug-naïve schizophrenia patients. This study aimed to explore the predictive value of plasma concentrations of Interferon-γ (IFN-γ) and Neutrophil gelatinase-associated lipocalin (NGAL) in early treatment responses.

METHODS

We conducted a longitudinal study involving 125 drug-naïve schizophrenia patients and 75 healthy controls. Plasma samples were collected and analyzed at baseline and after 8 weeks of treatment. Based on treatment outcomes, patients were classified as Responders (R, n = 84) or Non-responders (NR, n = 41).

RESULTS

At baseline, schizophrenia patients showed significantly lower IFN-γ and NGAL concentrations compared to healthy controls. NGAL levels were notably lower in the NR group compared to the R group. After treatment, both IFN-γ and NGAL concentrations increased in all patients, with a marked rise in IFN-γ levels. NGAL concentration negatively correlated with the positive factor at baseline, adjusting for confounders such as age, BMI, smoking, and duration of untreated illness. Logistic regression analysis identified lower baseline NGAL concentrations as a predictor of poor early treatment response.

CONCLUSION

Pre-treatment plasma NGAL concentrations may serve as a potential biomarker for predicting early treatment response in drug-naïve Chinese Han schizophrenia patients. These findings highlight NGAL as a possible target for future therapeutic development in schizophrenia.