Neurogênese e depressão: etiologia ou nova ilusão?

Anti-inflammatory and protective effects of Aripiprazole on TNBS-Induced colitis and associated depression in rats: Role of kynurenine pathway

BACKGROUND

The prevalence of depression is higher in patients with inflammatory bowel disease (IBD) than in the general population. Inflammatory cytokines and the kynurenine pathway (KP) play important roles in IBD and associated depression. Aripiprazole (ARP), an atypical antipsychotic, shows various anti-inflammatory properties and may be useful in treating major depressive disorder. This study aimed to evaluate the protective effects of ARP on TNBS-induced colitis and subsequent depression in rats, highlighting the role of the KP.

MATERIAL AND METHODS

Fifty-six male Wistar rats were used, and all groups except for the normal and sham groups received a single dose of intra-rectal TNBS. Three different doses of ARP and dexamethasone were injected intraperitoneally for two weeks in treatment groups. On the 15th day, behavioral tests were performed to evaluate depressive-like behaviors. Colon ulcer index and histological changes were assessed. The tissue levels of inflammatory cytokines, KP markers, lipopolysaccharide (LPS), nuclear factor-kappa-B (NF-κB), and zonula occludens (ZO-1) were evaluated in the colon and hippocampus.

RESULTS

TNBS effectively induced intestinal damages and subsequent depressive-like symptoms in rats. TNBS treatment significantly elevated the intestinal content of inflammatory cytokines and NF-κB expression, dysregulated the KP markers balance in both colon and hippocampus tissues, and increased the serum levels of LPS. However, treatment with ARP for 14 days successfully reversed these alterations, particularly at higher doses.

CONCLUSION

ARP could alleviate IBD-induced colon damage and associated depressive-like behaviors mainly via suppressing inflammatory cytokines activity, serum LPS concentration, and affecting the NF-κB/kynurenine pathway.

Polarization to M1-type microglia in the hippocampus is involved in depression-like behavior in a mouse model of olfactory dysfunction

Impaired olfactory function may be associated with the development of psychiatric disorders such as depression and anxiety; however, knowledge on the mechanisms underlying psychiatric disorders is incomplete. A reversible model of olfactory dysfunction, zinc sulfate (ZnSO4) nasal-treated mice, exhibit depression-like behavior accompanying olfactory dysfunction. Therefore, we investigated olfactory function and depression-like behaviors in ZnSO4-treated mice using the buried food finding test and tail suspension test, respectively; investigated the changes in the hippocampal microglial activity and neurogenesis in the dentate gyrus by immunohistochemistry; and evaluated the inflammation and microglial polarity related-proteins in the hippocampus using western blot study. On day 14 after treatment, ZnSO4-treated mice showed depression-like behavior in the tail suspension test and recovery of the olfactory function in the buried food finding test. In the hippocampus of ZnSO4-treated mice, expression levels of ionized calcium-binding adapter molecule 1 (Iba1), cluster of differentiation 40, inducible nitric oxide synthase, interleukin (IL)-1β, IL-6, tumor necrosis factor-α, cleaved caspase-3, as well as the number of Iba1-positive cells and cell body size increased, and arginase-1 expression and neurogenesis decreased. Except for the increased IL-6, these changes were prevented by a microglia activation inhibitor, minocycline. The findings suggest that neuroinflammation due to polarization of M1-type hippocampal microglia is involved in depression accompanied with olfactory dysfunction.

Hippocampal and gut AMPK activation attenuates enterocolitis-like symptoms and co-occurring depressive-like behavior in ulcerative colitis model mice: Involvement of brain-gut autophagy

Patients with inflammatory bowel disease, including ulcerative colitis (UC) and Crohn's disease, have a high incidence of psychiatric disorders, including depression and anxiety. However, the underlying pathogenic mechanism remains unknown. Dextran sulfate sodium (DSS)-treated mice, a model of UC, exhibit depressive-like behavior and reduced adenosine monophosphate-activated protein kinase (AMPK) activity, which regulates various physiological functions in the brain and gut. However, comprehensive studies on UC pathophysiology with co-occurring depression focused on brain-gut AMPK activity are lacking. Therefore, we aimed to investigate whether resveratrol (RES), an AMPK activator, prevented DSS-induced UC-like symptoms and depressive-like behavior. DSS treatment induced UC-like pathology and depressive-like behavior, as assessed via the tail suspension test. Moreover, western blotting and immunohistochemical studies revealed that DSS increased p-p70S6 kinase (Thr389), p62, tumor necrosis factor-α, interleukin (IL)-1β, IL-18, NLR family pyrin domain containing 3 (NLRP3), cleaved caspase-1, cleaved Gasdermin-D (GSDMD), and cleaved caspase-3 expression levels in the rectum and hippocampus, and increased CD40, iNOS, and Kelch-like ECH-associated protein 1 expression levels, and the number of Iba1-positive cells in the hippocampus, and decreased p-AMPK and LC3II/I expression levels, and the number of NF-E2-related factor 2 (Nrf2)-positive cells, and reduced neurogenesis in the hippocampus. These changes were reversed by the RES administration. RES also enhanced PGC1α and SOD1 expression in the hippocampus of DSS-treated male mice. Moreover, NLRP3 staining was observed in the neurons and microglia, and cleaved GSDMD staining in neurons in the hippocampus of DSS-treated mice. Notably, RES prevented UC-like pathology and depressive-like behavior and enhancement of autophagy, decreased rectal and hippocampal inflammatory cytokines and inflammasome, and induced the Nrf2-PGC1α-SOD1 pathway in the hippocampus, resulting in neurogenesis in the hippocampal dentate gyrus. Our findings suggest that brain-gut AMPK activation may be an important therapeutic strategy in patients with UC and depression.

Liver hydrolysate prevents depressive-like behavior in an animal model of colitis: Involvement of hippocampal neurogenesis via the AMPK/BDNF pathway

Patients with inflammatory bowel disease (IBD) have higher rates of psychiatric pathology, including anxiety and depression. The dextran sulfate sodium (DSS)-treated mouse is a well-characterized animal model of colitis that exhibits IBD-like and depressive-like changes. A recent study found that phosphorylated (p-) adenosine monophosphate-activated protein kinase (AMPK) was associated with anti-inflammatory and antidepressant effects. Our previous research in an animal model of major depression suggests that liver hydrolysate (LH) has an antidepressant effect and combats physical fatigue by enhancement via the hippocampal or peripheral p-AMPK pathway. In this study, we examined whether or not LH has antidepressant and anti-inflammatory effects in mice with DSS-induced changes. We evaluated colon inflammation in DSS-treated mice and used the tail suspension and forced swimming tests to confirm whether or not LH prevents IBD-like symptoms and depressive-like behavior. Hippocampal expression of AMPK, brain-derived neurotrophic factor (BDNF), doublecortin, and neuronal nuclear antigen proteins was assessed by Western blotting. Hippocampal neurogenesis and morphometric changes in the microglia and astrocytes were examined by immunohistochemistry. DSS-treated mice showed IBD-like pathology and depressive-like behavior, a reduction in the hippocampal neuronal nuclear antigen level and neurogenesis, and increased hippocampal activation of microglia and astrocytes. These changes were reversed by LH. DSS-treated mice showed enhanced hippocampal expression of p-AMPK and BDNF after administration of LH. LH prevented depressive-like behavior by enhancing hippocampal neurogenesis through the AMPK/BDNF pathway and anti-neuroinflammation in the hippocampus. LH may be a therapeutic option for patients with IBD and depression.

Effect of Enterococcus faecalis 2001 on colitis and depressive-like behavior in dextran sulfate sodium-treated mice: involvement of the brain-gut axis

BACKGROUND

Patients with inflammatory bowel disease (IBD), including those with ulcerative colitis and Crohn's disease, have higher rates of psychiatric disorders, such as depression and anxiety; however, the mechanism of psychiatric disorder development remains unclear. Mice with IBD induced by dextran sulfate sodium (DSS) in drinking water exhibit depressive-like behavior. The presence of Lactobacillus in the gut microbiota is associated with major depressive disorder. Therefore, we examined whether Enterococcus faecalis 2001 (EF-2001), a biogenic lactic acid bacterium, prevents DSS-induced depressive-like behavior and changes in peripheral symptoms.

METHODS

We evaluated colon inflammation and used the tail suspension test to examine whether EF-2001 prevents IBD-like symptoms and depressive-like behavior in DSS-treated mice. The protein expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), X-linked inhibitor of apoptosis protein (XIAP), and cleaved caspase-3 in the rectum and hippocampus was assessed by western blotting. Hippocampal neurogenesis, altered nuclear factor-kappa B (NFκB) p65 morphometry, and the localization of activated NFκB p65 and XIAP were examined by immunohistochemistry.

RESULTS

Treatment with 1.5% DSS for 7 days induced IBD-like pathology and depressive-like behavior, increased TNF-α and IL-6 expression in the rectum and hippocampus, activated caspase-3 in the hippocampus, and decreased hippocampal neurogenesis. Interestingly, these changes were reversed by 20-day administration of EF-2001. Further, EF-2001 administration enhanced NFκB p65 expression in the microglial cells and XIAP expression in the hippocampus of DSS-treated mice.

CONCLUSION

EF-2001 prevented IBD-like pathology and depressive-like behavior via decreased rectal and hippocampal inflammatory cytokines and facilitated the NFκB p65/XIAP pathway in the hippocampus. Our findings suggest a close relationship between IBD and depression.

A neurobiologia da psicopatologia e psicoterapia e as implicações práticas de uma perspectiva materialista na definição de mente

La Psicología pasa en la actualidad por un cambio importante de paradigma teórico y conceptual. Este cambio fue bastante marcado en los años 90, considerada como la "década del cerebro", cuando aumentó significativamente el número de estudios de comportamiento que se basan en el funcionamiento del cerebro. La corriente principal de las ciencias de la conducta devueltos a la noción monista materialista que el cerebro y el comportamiento están intrínsecamente entrelazados. Esta idea salió de los laboratorios de investigación básica y llegó con fuerza en la investigación aplicada a la psicopatología y la psicoterapia. Esta revisión narrativa se pretende elaborar una visión actual de esta empresa científica, con énfasis en los esfuerzos dentro de las áreas de la psicología clínica y psicopatología. Al final, se analiza en qué medida este cambio de paradigma puede llegar a la práctica profesional de la psicología.

Depression and conservative surgery for breast cancer

BACKGROUND

Depression is prevalent among women and associated with reduced quality of life, and therefore it is important to determine its incidence in adult women, especially in those with breast cancer.

OBJECTIVE

To determine the occurrence of depression in women who underwent conservative surgery for breast cancer with or without breast reconstruction.

METHODS

Seventy-five women aged between 18 and 65 years were enrolled. Patients had undergone conservative surgery for breast cancer with immediate breast reconstruction (n = 25) or without breast reconstruction (n = 25) at least one year before the study. The control group consisted of 25 women without cancer, but of similar age and educational level distribution as the other two groups. The Beck Depression Inventory was used to measure depression. The collected data were assessed using analysis of variance and the χ² test.

RESULTS

There were no significant differences between groups in age (p = 0.72) or educational level (p = 0.20). A smaller number of patients had undergone the menopause (p = 0.02) in the control group than in other groups. There were no significant differences in occurrence of depression between groups (χ² = 9.97; p = 0.126). CONCLUSÍON: Conservative surgery for breast cancer did not affect the occurrence of depression in women, regardless of whether breast reconstruction was performed.