Underlying mechanisms of recombinant adeno-associated virus-mediated bicaudal C homolog 1 overexpression in the medial prefrontal cortex of mice with induced depressive-like behaviors

Novel synergistic treatment for depression: involvement of GSK3β-regulated AMPA receptors in the prefrontal cortex of mice

Previous evidence has suggested a vital role of glycogen synthase kinase 3β-mediated α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors trafficking in depression. Considering the antidepressant effect of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors activation in the prefrontal cortex, we hypothesized that glycogen synthase kinase 3β-induced alterations in α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors function in the prefrontal cortex participate in depression. Herein, we confirmed that the levels of phosphorylated glycogen synthase kinase 3β and GluA1, the latter being a subunit of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors, were decreased in the prefrontal cortex of the chronic social defeat stress model mice presenting with depressive-like behaviors. We then found that a glycogen synthase kinase 3β (p.S9A) point mutation downregulated GluA1 and induced depressive-like behaviors in mice, whereas an agonist of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors, PF-4778574 (2 mg/kg) did not reversed the molecular changes. On the other hand, the antidepressant effect of PF-4778574 was dose dependent, and the single administration of PF-4778574 at a lower dose (0.5 mg/kg) or of the glycogen synthase kinase 3β inhibitor SB216763 (5 and 10 mg/kg) did not evoke an antidepressant effect. In contrast, co-treatment with PF-4778574 (0.5 mg/kg) and SB216763 (10 mg/kg) led to antidepressant effects similar to those of PF-4778574 (2 mg/kg). Our results suggest that glycogen synthase kinase 3β-induced α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors dysfunction in the prefrontal cortex is one of the key mechanisms of depression, and the combination of a lower dose of PF-4778574 with SB216763 shows potential as a novel synergistic treatment for depression.

Bicaudal-C protein, a potential antidepressant target

Bicaudal-C protein is a highly conserved RNA binding protein, which contains K homology domains and sterile alpha motif domain. Genome-wide association study identified that Bicaudal-C protein was associated with depression. The expression of Bicaudal-C increased in depression patients, also increased expression of Bicaudal-C induces the behavior of depression. The decrease of synaptic plasticity plays a part in depression. Bicaudal-C protein reduces the synaptic plasticity of neurons via TrkB/mTOR/AMPA/pGluA1 pathways, Wnt pathway, or influencing some proteins related to synaptic plasticity. The decreased expression of Bicaudal-C plays an important role in the action of several antidepressants, such as ketamine, biperiden, and scopolamine. Therefore, Bicaudal-C protein may be a potential antidepressant target. Clarifying the relationship between Bicaudal-C protein and depression may help us to find new antidepressants. This review focuses on the research advances of the relationship between Bicaudal-C protein and depression.

Vortioxetine attenuates the effects of early-life stress on depression-like behaviors and monoamine transporters in female mice

Major depressive disorder is a major psychiatric disorder and a leading cause of disability around the world. Females have about twice as high an incidence of depression as males. However, preclinical animal models of depression have seldom investigated the molecular alterations associated with higher depression risk in females. In this study, adopting the early-life stress (ELS) paradigm of limited bedding and nesting material, we found that ELS induced depression-like behaviors only in adult female mice, as evaluated by sucrose preference and tail suspension tests. We then examined the ELS effects on monoamine neurotransmission (transporters for monoamine reuptake and release) in depression-related brain regions in female mice. We found that ELS resulted in widespread changes of the expression levels of these transporters in four brain regions. Moreover, systemic 21-day treatment with vortioxetine, a novel multimodal antidepressant, successfully reversed depression-like behaviors and normalized some molecular changes, including that of the norepinephrine transporter in the medial prefrontal cortex, vesicular monoamine transporter 2 in nucleus accumbens core, and serotonin transporter in amygdala. Collectively, these results provide evidence for the validity of using the limited bedding and nesting material paradigm to investigate sex differences in depression and demonstrate that the region-specific alterations of monoamine neurotransmission may be associated with depression-like behaviors in female mice. This article is part of the special issue on 'Stress, Addiction and Plasticity'.

Mechanisms and Therapeutic Implications of GSK-3 in Treating Neurodegeneration

Neurodegenerative disorders are spreading worldwide and are one of the greatest threats to public health. There is currently no adequate therapy for these disorders, and therefore there is an urgent need to accelerate the discovery and development of effective treatments. Although neurodegenerative disorders are broad ranging and highly complex, they may share overlapping mechanisms, and thus potentially manifest common targets for therapeutic interventions. Glycogen synthase kinase-3 (GSK-3) is now acknowledged to be a central player in regulating mood behavior, cognitive functions, and neuron viability. Indeed, many targets controlled by GSK-3 are critically involved in progressing neuron deterioration and disease pathogenesis. In this review, we focus on three pathways that represent prominent mechanisms linking GSK-3 with neurodegenerative disorders: cytoskeleton organization, the mammalian target of rapamycin (mTOR)/autophagy axis, and mitochondria. We also consider the challenges and opportunities in the development of GSK-3 inhibitors for treating neurodegeneration.