Sex-dependent role of CD300f immune receptor in generalized anxiety disorder.

Generalized Anxiety Disorder (GAD) presents a high prevalence in the population, leading to distress and disability. Immune system alterations have been associated with anxiety-related behaviors in rodents and GAD patients. CD300f immune receptors are highly expressed in microglia and participate not only in the modulation of immune responses but also in pruning and reshaping synapses. It was recently demonstrated that CD300f might be influential in the pathogenesis of depression in a sex-dependent manner. Here, we evaluated the role of CD300f immune receptor in anxiety, using CD300f knockout mice (CD300f-/-) and patients with GAD. We observed that male CD300f-/- mice had numerous behavioral changes associated with a low-anxiety phenotype, including increased open field central locomotion and rearing behaviors, more exploration in the open arms of the elevated plus-maze test, and decreased latency to eat in the novelty suppressed feeding test. In a cross-sectional population-based study, including 1111 subjects, we evaluated a common single-nucleotide polymorphism rs2034310 (C/T) in the cytoplasmatic tail of CD300f gene in individuals with GAD. Notably, we observed that the T allele of the rs2034310 polymorphism conferred protection against GAD in men, even after adjusting for confounding variables. Overall, our data demonstrate that CD300f immune receptors are involved in the modulation of pathological anxiety behaviors in a sex-dependent manner. The biological basis of these sex differences is still poorly understood, but it may provide significant clues regarding the neuropathophysiological mechanisms of GAD and can pave the way for future specific pharmacological interventions

Novel approaches for the management of depressive disorders

AbstractMajor depressive disorder is a disabling psychiatric condition that causes a significant burden on individuals and society. There is still a lack of a clear understanding of the neuropathological changes associated with this illness and the efficacy of antidepressants is still far from optimal. Research into antidepressant therapies has evolved from serendipitous observation in human trials, but more than 60 years after the first monoaminergic antidepressants emerged they remain the mainstay for treating depression. However, glutamatergic modulators such as ketamine became the forefront of antidepressant exploration, especially for treatment-resistant depression and suicidal ideation. The glutamatergic hypothesis of depression is not new, however other NMDA receptor modulators do not seem to share the rapid and sustained effects of ketamine, suggesting that a unique combination of intracellular targets might be involved in its effect. Interestingly, inflammation can impact the glutamatergic system enhancing excitotoxicity and decreasing neuroplasticity. The points of convergence between the inflammatory and glutamatergic hypotheses of depression are not completely established, especially regarding the effects of fast-acting antidepressants. In this review, we discuss the most recent research surrounding glutamatergic fast-acting antidepressants, capable of modulating cellular plasticity and synaptogenesis and the potential of anti-inflammatory compounds evaluated from a different perspective. The combination of innovative ideas plus improvements on the discoveries made so far might lead to advances in antidepressant research with the promise of finding compounds that are both effective and fast-acting, even in patients who have tried other therapies with limited success

Association of interleukin-10 levels with age of onset and duration of illness in patients with major depressive disorder

Objective:To investigate peripheral levels of interleukin-10 (IL-10) in patients with major depressive disorder (MDD) and bipolar disorder (BD) and evaluate the relationship between IL-10, age of disease onset, and duration of illness.Methods:Case-control study nested in a population-based cohort of 231 individuals (age 18-24 years) living in Pelotas, state of Rio Grande do Sul, Brazil. Participants were screened for psychopathology using the Mini-International Neuropsychiatric Interview (MINI) and the Structured Clinical Interview for DSM-IV (SCID-I). Serum IL-10 was measured using commercially available immunoassay kits.Results:Peripheral levels of IL-10 were not significantly different in individuals with MDD or BD as compared to controls. However, higher IL-10 levels were found in MDD patients with a later disease onset as compared with controls or early-onset patients. In addition, IL-10 levels correlated negatively with illness duration in the MDD group. In the BD group, age of onset and duration of illness did not correlate with IL-10 levels.Conclusion:Higher levels of IL-10 are correlated with late onset of MDD symptoms. Moreover, levels of this cytokine might decrease with disease progression, suggesting that an anti-inflammatory balance may be involved in the onset of depressive symptoms and disease progression in susceptible individuals

Sex-dependent role of CD300f immune receptor in generalized anxiety disorder

Generalized Anxiety Disorder (GAD) presents a high prevalence in the population, leading to distress and disability. Immune system alterations have been associated with anxiety-related behaviors in rodents and GAD patients. CD300f immune receptors are highly expressed in microglia and participate not only in the modulation of immune responses but also in pruning and reshaping synapses. It was recently demonstrated that CD300f might be influential in the pathogenesis of depression in a sex-dependent manner. Here, we evaluated the role of CD300f immune receptor in anxiety, using CD300f knockout mice (CD300f−/−) and patients with GAD. We observed that male CD300f−/− mice had numerous behavioral changes associated with a low-anxiety phenotype, including increased open field central locomotion and rearing behaviors, more exploration in the open arms of the elevated plus-maze test, and decreased latency to eat in the novelty suppressed feeding test. In a cross-sectional population-based study, including 1111 subjects, we evaluated a common single-nucleotide polymorphism rs2034310 (C/T) in the cytoplasmatic tail of CD300f gene in individuals with GAD. Notably, we observed that the T allele of the rs2034310 polymorphism conferred protection against GAD in men, even after adjusting for confounding variables. Overall, our data demonstrate that CD300f immune receptors are involved in the modulation of pathological anxiety behaviors in a sex-dependent manner. The biological basis of these sex differences is still poorly understood, but it may provide significant clues regarding the neuropathophysiological mechanisms of GAD and can pave the way for future specific pharmacological interventions