Lymphocyte Phospho-Ser-9-GSK-3β/Total GSK-3β Protein Levels Ratio Is Not Affected by Chronic Lithium or Valproate Treatment in Euthymic Patients With Bipolar Disorder

Combined treatment with valproic acid and estrogen has neuroprotective effects in ovariectomized mice with Alzheimer's disease

Postmenopausal women with Alzheimer’s disease (AD) exhibit dramatically reduced sensitivity to estrogen replacement therapy, which is though to be related to an estrogen receptor (ER)α/ERβ ratio imbalance arising from a significantly decreased level of ERs of the brain. The aim of our study was to investigate whether valproic acid (VPA) can enhance the beneficial effects of estrogen on cognitive function through restoration of ERα and ERβ expression in the brain. We removed the ovaries of female APP/PS1 mice to simulate the low estrogen levels present in postmenopausal women and then administered VPA (30 mg/kg, intraperitoneal injection, once daily), 17β-estradiol (E2) (2.4 μg, intraperitoneal injection, once daily), liquiritigenin (LG) (50 μg/kg, intragastric infusion, once daily), VPA + E2, or VPA + LG for 4 successive weeks. Compared with treatment with a single drug, treatment with VPA + E2 or VPA + LG significantly increased the level of glycogen synthase kinase 3β, increased the expression of estrogen receptor α, reduced the expression of small ubiquitin-like modifiers, and increased the level of estrogen receptor β. This resulted in enhanced sensitivity to estrogen therapy, reduced amyloid β aggregation, reduced abnormal phosphorylation of the tau protein, reduced neuronal loss, increased dendritic spine and postsynaptic density, and significantly alleviated memory loss and learning impairment in mice. This study was approved by the Chongqing Medical University Animal Protection and Ethics Committee, China on March 6, 2013.

Dual Role of Autophagy in Diseases of the Central Nervous System

Autophagy is a vital lysosomal degradation and recycling pathway in the eukaryotic cell, responsible for maintaining an intricate balance between cell survival and cell death, necessary for neuronal survival and function. This dual role played by autophagy raises the question whether this process is a protective or a destructive pathway, the contributor of neuronal cell death or a failed attempt to repair aberrant processes? Deregulated autophagy at different steps of the pathway, whether excessive or downregulated, has been proposed to be associated with neurodegenerative disorders such as Alzheimer's-, Huntington's-, and Parkinson's-disease, known for their intracellular accumulation of protein aggregates. Recent observations of impaired autophagy also appeared in psychiatric disorders such as schizophrenia and bipolar disorder suggesting an additional contribution to the pathophysiology of mental illness. Here we review the current understanding of autophagy's role in various neuropsychiatric disorders and, hitherto, the prevailing new potential autophagy-related therapeutic strategies for their treatment.

Impaired glucose metabolism in bipolar patients and response to mood stabilizer treatments

BACKGROUND

Metabolic dysfunctions in patients with bipolar disorder (BD) are critical factors that interfere with outcome, but only one study evaluated the influence of glucose dysmetabolism on the response to treatment with lithium. We aimed to investigate the potential impact of glucose metabolic status on clinical characteristics of BD patients and their response to treatment with different mood stabilizers in monotherapy or in combination.

METHODS

45 BD patients with insulin resistance (IR) or type 2 diabetes mellitus (DM2) and 46 patients with normal glucose metabolism, treated with mood stabilizers for at least one year were assessed by diagnostic and rating instruments. Their clinical characteristics were compared and an ordinal logistic regression model was adopted to identify possible predictors of response to mood stabilizer treatments.

RESULTS

Compared to patients with normal glucose metabolism, BD patients with impaired glucose metabolism showed a worse clinical presentation of their psychiatric illness and a worse response to mood stabilizers. Ordinal logistic regression analysis evidenced that impaired glucose metabolism was the only predictor of poor response to mood stabilizers (OR 4.3; 95% CI: 1.7-11.1; p < 0.002).

LIMITATIONS

Cross-sectional design and the relatively small sample size, are the main limitations of our study.

CONCLUSIONS

Our findings expand literature data suggesting that BD patients with impaired glucose metabolism are at a greater risk of not responding to lithium as well as to different mood stabilizer treatments.