Perinatal exposure to bisphenol A causes a disturbance of neurotransmitter metabolic pathways in female mouse offspring: A focus on the tryptophan and dopamine pathways
CHEMOSPHERE
Authors: Yao, Jiaxi; Wang, Jun; Wu, Linlin; Lu, Haihua; Wang, Zhonghe; Yu, Pengfei; Xiao, Hang; Gao, Rong; Yu, Jing
Abstract
Perinatal exposure to bisphenol A (BPA) contributes to neurological disorders in offspring, but the underlying mechanisms are still poorly understood. The abnormal release of neuroactive metabolites in the tryptophan (TRP) and dopamine (DA) pathways is considered to be closely associated with some disorders. Thus, in this study, TRP and DA pathways in adult female mouse offspring were investigated when the pregnant mice were given either vehicle or BPA (2, 10, or 100 mu g/kg/d) from day 6 of gestation until weaning. Then, the serum and brain samples of offspring were collected at 3, 6 and 9 months, and 12 neuroactive metabolites in the TRP and DA pathways were detected. The results showed that, in the TRP pathway, TRP levels decreased, whereas kynurenine (KYN) levels and TRP turnover increased in the brain. In the serum, TRP, KYN and 5-hydroxytryptamine (5-HT) levels decreased significantly. For the DA pathway, DA and DA metabolites, including 3,4-dihydroxyphenylacetic acid (DOPAC), 3-methoxytyramine (3-MT) and homovanillic acid (HVA), reduced significantly in the brain and serum. DA turnover decreased dramatically in the brain but enhanced in the serum. The disturbance of these two metabolic pathways might be one of the potential mechanisms of BPA-induced neuropsychiatric disorders. (C) 2020 Elsevier Ltd. All rights reserved.
Differential Induction of SOCS Isoforms by Leishmania donovani Impairs Macrophage-T Cell Cross-Talk and Host Defense
JOURNAL OF IMMUNOLOGY
Authors: Chandrakar, Pragya; Parmar, Naveen; Descoteaux, Albert; Kar, Susanta
Abstract
Immune evasion strategies adopted by Leishmania donovani involve the exploitation of suppressor of cytokine signaling (SOCS) proteins that are well-known negative regulators of the JAK/STAT pathway. However, the cellular mechanism underpinning the induction of SOCS isoforms and their role in breaching the multilevel regulatory circuit connecting the innate and adaptive arms of immunity are still ambiguous during experimental visceral leishmaniasis. Using bone marrow-derived macrophages (BMM phi s) and CD4(+) T cells, we observed that L. donovani preferentially upregulates SOCS1 and SOCS3 expression in macrophages and T cells, respectively, whereas the SOCS1 level remains consistently high in BMM phi s and SOCS3 expression is pronounced and long lasting in T cells. Consequently, this inhibits STAT1-mediated IL-12 induction in macrophages & STAT4-mediated IFN-gamma synthesis in T cells. Mechanistically, PI3K/Akt-mediated SRF activation promotes nuclear translocation and binding of Egr2 to SOCS1 promoter for its early induction in infected BMM phi s. Additionally, L. donovani activates IDO/kynurenine/AHR signaling in BMM phi s to maintain prolonged SOCS1 expression. Later, PGE2, secreted from infected BMM phi s induces cAMP-PKA pathway by binding to the EP2/EP4 receptor of CD4(+) T cells, leading to SP1, CREB, and GATA1 activation and SOCS3 expression. Small interfering RNA-mediated silencing of SOCS1 and SOCS3 in macrophage and T cells, respectively, restored IL-12 and IFN-gamma cytokine levels and BMM phi-T cell interaction. Vivo morpholino-mediated silencing of SOCS1 and SOCS3 resulted in protective cytokine responses, thereby reducing organ parasite burden significantly in L. donovani-infected BALB/c mice. Collectively, our results imply that L. donovani orchestrates different SOCS isoforms to impair macrophage-T cell cross-talk and preserve its own niche.