Depression is the most prevalent stress-associated mental condition, imposing a serious economic burden on our society. Although there are a number of clinically effective treatments for depression and associated psychiatric conditions, a large segment of patients exhibit treatment-resistance to first-line interventions;limitations in current antidepressants call for novel interventions based on pathological mechanisms of depression. Accumulating evidence suggests that alterations in immune and inflammation processes, including changes in expression of pro- and anti-inflammatory cytokines are observed in patients with depression, whereby high stress environments may exacerbate their perturbed regulation. Consistently, chronic exposure to social defeat stress in rodents induces intracerebral activation of immune and inflammation systems, including elevation of certain cytokines, that are largely regulated by immune cells, including microglia which may underlie depressive animal behaviors. Notably, many natural products used in traditional Eastern medicine, such as Kanpo (adaptation of traditional Chinese medicine, Japan), have been shown to function as anti-inflammatory factors and antidepressants and have been empirically used for treatment and prevention of inflammation-associated human disease, including depression. Nonetheless, there is almost no mechanism-based evidence for the effectiveness of traditional herbal medicines in treatment of depression. Pachyman (1,3-?-Glucans) is a main ingredient of several Eastern medicines, such as Yokukansan. In addition to the evidence of the antidepressant effect of Yokukansan, pachyman is reported to have anti-immune/inflammatory effects. Taken together, understanding the mechanistic link between its antidepressant and anti-inflammatory effects may open a new window for identification of novel preventive and/or treatment targets for depressive symptoms. In this project, we test the hypothesis that pachyman may ameliorate stress-associated immune/inflammation changes, leading to antidepressant effects. We will examine the protective and treatment effect of pachyman on stress-induced microglial immune changes and depressive behaviors using mice subjected to social defeat stress (Aims 1 and 2). Finally, based on our preliminary findings showing the strong suppressive effect of pachyman on stress-induced microglial IL18 expression in the prefrontal cortex, we will investigate whether microglia-specific knockdown of IL18 in the medial prefrontal cortex may ameliorate depressive behaviors induced by chronic social defeat stress. Defining the mechanism of action of pachyman may provide a basis for identifying novel drug targets for the prevention and treatment of depression and related mental conditions.

Public Health Relevance

Depression is the most prevalent stress-associated mental condition, imposing a serious economic burden on our society. Given that the currently available antidepressants have notable limitations in regards to their therapeutic effects, finding novel therapeutic targets is crucial. In this project, we will examine the effect of pachyman, an ingredient often used empirically in traditional Eastern medicine, on stress-associated immune changes and depressive-like behaviors. This study will determine the usefulness of natural products as tools to find novel therapeutic targets for prevention and treatment of psychiatric conditions.

National Institute of Health (NIH)
National Center for Complementary & Alternative Medicine (NCCAM)
Exploratory/Developmental Grants (R21)
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Pathophysiological Basis of Mental Disorders and Addictions Study Section (PMDA)
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Hopp, Craig
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Johns Hopkins University
Schools of Medicine
United States
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Fukudome, Daisuke; Hayes, Lindsay N; Faust, Travis E et al. (2018) Translocator protein (TSPO) and stress cascades in mouse models of psychosis with inflammatory disturbances. Schizophr Res :
Xu, Zhexue; Zhang, Shu; Huang, Liyuan et al. (2018) Altered Resting-State Brain Activities in Drug-Naïve Major Depressive Disorder Assessed by fMRI: Associations With Somatic Symptoms Defined by Yin-Yang Theory of the Traditional Chinese Medicine. Front Psychiatry 9:195
Zhu, Xiaolei; Nedelcovych, Michael T; Thomas, Ajit G et al. (2018) JHU-083 selectively blocks glutaminase activity in brain CD11b+ cells and prevents depression-associated behaviors induced by chronic social defeat stress. Neuropsychopharmacology :
Saito, Atsushi; Taniguchi, Yu; Kim, Sun-Hong et al. (2017) Developmental Alcohol Exposure Impairs Activity-Dependent S-Nitrosylation of NDEL1 for Neuronal Maturation. Cereb Cortex 27:3918-3929
Yoshimura, Atsushi; Goodson, Carrie; Johns, Jordan T et al. (2017) Altered cortical brain activity in end stage liver disease assessed by multi-channel near-infrared spectroscopy: Associations with delirium. Sci Rep 7:9258
Nishi, Akira; Numata, Shusuke; Tajima, Atsushi et al. (2017) De novo non-synonymous TBL1XR1 mutation alters Wnt signaling activity. Sci Rep 7:2887
Niwa, M; Cash-Padgett, T; Kubo, K-I et al. (2016) DISC1 a key molecular lead in psychiatry and neurodevelopment: No-More Disrupted-in-Schizophrenia 1. Mol Psychiatry 21:1488-1489
Kondo, Mari A; Fukudome, Daisuke; Smith, Dani R et al. (2016) Dimensional assessment of behavioral changes in the cuprizone short-term exposure model for psychosis. Neurosci Res 107:70-74
Gancarz, Amy; Jouroukhin, Yan; Saito, Atsushi et al. (2016) DISC1 signaling in cocaine addiction: Towards molecular mechanisms of co-morbidity. Neurosci Res 105:70-4
Saito, A; Taniguchi, Y; Rannals, M D et al. (2016) Early postnatal GABAA receptor modulation reverses deficits in neuronal maturation in a conditional neurodevelopmental mouse model of DISC1. Mol Psychiatry 21:1449-59

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