Aim: Major depressive disorder (MDD) is a debilitating mental disorder associated with dysfunction of the neurotransmitterneuroendocrine system and neuroinflammatory responses. Salvianolic acid B (SalB) has shown a variety of pharmacological activities, including anti-inflammatory, antioxidant and neuroprotective effects. In this study, we examined whether SalB produced antidepressantlike actions in a chronic mild stress (CMS) mouse model, and explored the mechanisms underlying the antidepressant-like actions of SalB. Methods: Mice were subjected to a CMS paradigm for 6 weeks. In the last 3 weeks the mice were daily administered SalB (20 mg·kg -1 ·d -1 , ip) or a positive control drug imipramine (20 mg·kg -1 ·d -1 , ip). The depressant-like behaviors were evaluated using the sucrose preference test, the forced swimming test (FST), and the tail suspension test (TST). The gene expression of cytokines in the hippocampus and cortex was analyzed with RT-PCR. Plasma corticosterone (CORT) and cerebral cytokines levels were assayed with an ELISA kit. Neural apoptosis and microglial activation in brain tissues were detected using immunofluorescence staining. Results: Administration of SalB or imipramine reversed the reduced sucrose preference ratio of CMS-treated mice, and significantly decreased their immobility time in the FST and TST. Administration of SalB significantly decreased the expression of pro-inflammatory cytokines IL-1β and TNF-α, and markedly increased the expression of anti-inflammatory cytokines IL-10 and TGF-β in the hippocampus and cortex of CMS-treated mice, and normalized their elevated plasma CORT levels, whereas administration of imipramine did not significantly affect the imbalance between pro-and anti-inflammatory cytokines in the hippocampus and cortex of CMS-treated mice. Finally, administration of SalB significantly decreased CMS-induced apoptosis and microglia activation in the hippocampus and cortex, whereas administration of imipramine had no significant effect on CMS-induced apoptosis and microglia activation in the hippocampus and cortex. Conclusion: SalB exerts potent antidepressant-like effects in CMS-induced mouse model of depression, which is associated with the inhibiting microglia-related apoptosis in the hippocampus and the cortex.
Background and Aims Yes‐associated protein (YAP) plays an important role in hepatocarcinogenesis, although the potential role of YAP in non‐neoplastic liver diseases remains largely unknown. We report herein that YAP in Kupffer cells (KCs) enhances the production of proinflammatory cytokines and promotes the development of nonalcoholic steatohepatitis (NASH). Our data show that the expression of YAP is significantly increased in KCs of wild‐type mice fed a high‐fat diet (HFD). Approach and Results We generated mice with macrophage/monocyte‐specific deletion of YAP (YAPϕKO) or Toll‐like receptor 4 (TLR4; TLR4ϕKO), and animals were fed an HFD or treated with lipopolysaccharide (LPS). Our data showed that YAPϕKO mice fed an HFD exhibited lower serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST) levels and less hepatic inflammation when compared to their littermate controls. LPS treatment induced accumulation of YAP in KCs in vitro and in mice, which was prevented by macrophage/monocyte‐specific deletion of TLR4 (TLR4ϕKO). LPS transcriptionally activates YAP through activator protein 1 in macrophages/KCs. LPS‐induced YAP further enhances expression of proinflammatory cytokines (including monocyte chemoattractant protein 1, tumor necrosis factor alpha, and interleukin 6) through YAP association with the TEA domain–binding motif in the promoter region of inflammatory cytokines. Forced overexpression of active YAP (YAP5SA) in KCs enhanced the production of proinflammatory cytokines. Treatment of HFD‐fed mice with verteporfin inhibited KC activation, reduced liver inflammation, and decreased serum ALT/AST levels. Analyses of liver tissues from NASH patients reveal that YAP is increased in KCs and that level of YAP in human liver tissues is positively correlated with expression of proinflammatory cytokines. Conclusions This study describes an important role of YAP in KCs for regulation of liver inflammation in NASH. Our findings suggest that inhibition of YAP may represent an effective therapeutic strategy for NASH treatment.
The innovative development of azapeptide analogues of growth hormone releasing peptide-6 (GHRP-6) has produced selective modulators of the cluster of differentiation 36 receptor (CD36). The azapeptide CD36 modulators curb macrophage-driven inflammation and mitigate atherosclerotic and angiogenic pathology. In macrophages activated with Toll-like receptor-2 heterodimer agonist, they reduced nitric oxide production and proinflammatory cytokine release. In a mouse choroidal explant microvascular sprouting model, they inhibited neovascularization. In murine models of cardiovascular injury, CD36-selective azapeptide modulators exhibited cardioprotective and anti-atherosclerotic effects. In subretinal inflammation models, they altered activated mononuclear phagocyte metabolism and decreased immune responses to alleviate subsequent inflammation-dependent neuronal injury associated with retinitis pigmentosa, diabetic retinopathy and age-related macular degeneration. The translation of GHRP-6 to potent and selective linear and cyclic azapeptide modulators of CD36 is outlined in this review which highlights the relevance of turn geometry for activity and the biomedical potential of prototypes for the beneficial treatment of a wide range of cardiovascular, metabolic and immunological disorders.
Aim: Indoleamine 2, 3-dioxygenase (IDO) is responsible for the progression of the kynurenine pathway, which has been implicated in the pathophysiology of inflammation-induced depression. It has been reported that asperosaponin Ⅵ (ASA Ⅵ) could play a neuroprotective role through anti-inflammatory and antioxidant. In this study, we examined the antidepressant effect of ASA Ⅵ in LPS-treated mice and further explored its molecular mechanism by insight into the microglial kynurenine pathway.Methods: To produce the model, lipopolysaccharide (LPS) (0.83 mg/kg) was administered intraperitoneally to mice. The mice received ASA Ⅵ (10 mg/kg, 20mg/kg, 40mg/kg and 80mg/kg, i.p.) thirty minutes prior to LPS injection. Depressive-like behaviors were evaluated based on the duration of immobility in the forced swim test. Microglial activation and . CC-BY-NC-ND 4.0 International license made available under a (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is The copyright holder for this preprint this version posted March 15, 2020. ;
Although much progress has been made in understanding cancer cellular metabolism adaptation, the co-regulations between genes of metabolism and cancer pathways and their interactions remain poorly characterized. Here, we applied gene co-expression network analysis to 1509 metabolic gene expression data generated from 120 HCC and 180 non-tumor human liver tissues by microarray. Our analyses reveal that metabolism genes can be classified into different co-expression modules based on their associations with HCC related traits. The co-regulation mechanism of the carbon metabolism genes in normal liver tissues was interrupted during the processes of carcinogenesis. In parallel, we performed RNAseq analysis of HCC and non-tumor human liver tissues, and identified a unique 22-carbon-metabolism-gene-signature of increased expression. This gene signature was further verified in multiple microarray data sets, and its prognostic value was also proven by HCC patients' survival data from TCGA. Additionally, the tumorigenic function of two representative genes, CS and ACSS1, were validated experimentally by cell growth and spheroid formation assays. The current study provides evidence for the reprogramming of the co-regulation network between carbon metabolism and cancer pathway genes in HCC. In addition, this study also reveals a unique 22-carbon-metabolism-gene-expression-signature in HCC. Strategies targeting these genes may represent new therapeutic approaches for HCC treatment.
Background The natural compound asperosaponin VI has shown potential as an antidepressant, but how it works is unclear. Here, we explored its effects on mice exposed to chronic mild stress (CMS) and the underlying molecular pathways. Methods Mice were exposed to CMS for 3 weeks followed by asperosaponin VI (40 mg/kg) or imipramine (20 mg/kg) for another 3 weeks. Depression-like behaviors were assessed in the forced swimming test (FST), sucrose preference test (SPT), tail suspension test (TST). Microglial phenotypes were evaluated using immunofluorescence staining, real-time quantitative PCR and enzyme-linked immunosorbent assays in hippocampus of mice. In some experiments, stressed animals were treated with the PPAR-γ antagonist GW9662 to examine its involvement in the effects of asperosaponin VI. Blockade of PPAR-γ in asperosaponin VI-treated primary microglia in the presence of lipopolysaccharide (LPS) was executed synchronously. The nuclear transfer of PPAR-γ in microglia was detected by immunofluorescence staining in vitro and in vivo. A co-cultured model of neuron and microglia was used for evaluating the regulation of ASA VI on the microglia–neuron crosstalk molecules. Results Asperosaponin VI ameliorated depression-like behaviors of CMS mice based on SPT, TST and FST, and this was associated with a switch of hippocampal microglia from a pro-inflammatory (iNOS+-Iba1+) to neuroprotective (Arg-1+-Iba1+) phenotype. CMS reduced the expression levels of PPAR-γ and phosphorylated PPAR-γ in hippocampus, which asperosaponin VI partially reversed. GW9662 treatment prevented the nuclear transfer of PPAR-γ in asperosaponin VI-treated microglia and inhibited the induction of Arg-1+ microglia. Blockade of PPAR-γ signaling also abolished the ability of asperosaponin VI to suppress pro-inflammatory cytokines while elevating anti-inflammatory cytokines in the hippocampus of CMS mice. The asperosaponin VI also promoted interactions between hippocampal microglia and neurons by enhancing CX3CL1/CX3CR1 and CD200/CD200R, and preserved synaptic function based on PSD95, CamKII β and GluA levels, but not in the presence of GW9662. Blockade of PPAR-γ signaling also abolished the antidepressant effects of asperosaponin VI in the SPT, TST and FST. Conclusion CMS in mice induces a pro-inflammatory microglial phenotype that causes reduced crosstalk between microglia and neuron, inflammation and synaptic dysfunction in the hippocampus, ultimately leading to depression-like behaviors. Asperosaponin VI may ameliorate the effects of CMS by inducing microglia to adopt a PPAR-γ-dependent neuroprotective phenotype.
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