Microglia, as phagocytes and antigen-presenting cells in the central nervous system, are activated in such disease processes as stroke and multiple sclerosis. Because peripheral macrophages are capable of producing endocannabinoids, we have examined endocannabinoid production in a macrophage-colony stimulating factor (M-CSF)-dependent rat microglial cell line (RTMGL1) using reversed phase high-pressure liquid chromatography and liquid chromatography-mass spectroscopy. We determined that cultured microglial cells produce the endocannabinoid 2-arachidonylglycerol (2-AG) as well as anandamide in smaller quantities. When 2-AG, but not anandamide, is added exogenously, RT-MGL1 microglia increase their proliferation. This increased proliferation is blocked by an antagonist of the CB 2 receptor N-[(1S)-endo-1,3,3-trimethyl bicyclo heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide (SR144528) and mimicked by the CB 2 receptor-specific agonist 1,1-dimethylbutyl-1-deoxy-⌬ 9 -tetrahydrocannabinol (JWH133). Accompanying the increase in proliferation seen with 2-AG is an increase in active ERK1 that is also blocked with SR144528. The RTMGL1 microglial cells, which exist in a primed state, express the CB 1 and CB 2 receptors as demonstrated by reverse transcription-polymerase chain reaction and immunostaining. The CB 2 receptor in untreated cells is expressed both at the cell surface and internally, and exposure of the cells to 2-AG significantly increases receptor internalization. These data suggest that 2-AG activation of CB 2 receptors may contribute to the proliferative response of microglial cells, as occurs in neurodegenerative disorders.

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SummaryThe plant phytohormone abscisic acid (ABA) plays significant roles in integrating environmental signals with embryogenesis, germination, seedling establishment, the floral transition and the adaptation of plants to stressful environments by modulating stomatal movement and stress‐responsive gene expression. ABA signalling consists of ABA perception, signal transduction and ABA‐induced responses. ABA receptors such as members of the PYR/PYL family, group A type 2C protein phosphatases (as negative regulators), SnRK2 protein kinases (as positive regulators), bZIP transcription factors and ion channels are key components of ABA signalling. Post‐translational modifications, including dephosphorylation, phosphorylation and ubiquitination, play important roles in regulating ABA signalling. In this review, we focus on the roles of post‐translational modifications in ABA signalling. The studies presented provide a detailed picture of the ABA signalling network.

Adropin, a secretory signal peptide, has shown beneficial effects on improving glucose homeostasis and dyslipidemia. However, whether this peptide affects nonalcoholic steatohepatitis (NASH) has remained unclear. In this study, the serum adropin levels, liver injury and oxidative stress were measured in diet-induced NASH mice. Adropin knock-out mice and palmitate treated primary hepatic cells were used to investigate the influence of adropin on liver injury. Our results show that serum adropin levels were decreased and negatively correlated with liver injury in NASH mice. Knockout of adropin significantly exacerbated hepatic steatosis, inflammatory responses and fibrosis in mice after either methionine-choline deficient diet (MCD) or western diet (WD) feeding. And the treatment with adropin bioactive peptides ameliorated NASH progression in mice. Adropin alleviated hepatocyte injury by upregulating the expression of Gclc, Gclm, and Gpx1 in a manner dependent on Nrf2 transcriptional activity and by increasing the glutathione (GSH) levels. And adropin significantly increased CBP expression and promoted its binding with Nrf2, which enhanced Nrf2 transcriptional activity. Furthermore, AAV8-mediated overexpression of hepatic Nrf2 expression functionally restored the liver injury induced by adropin-deficiency MCD-fed mice. These findings provide evidence that adropin activates Nrf2 signaling and plays a protective role in liver injury of NASH and therefore might represent a novel target for the prevention and treatment of NASH.

Bacterial translocation and lipopolysaccharide (LPS) leakage occur at a very early stage of liver fibrosis in animal models. We studied the role of LPS in hepatic stellate cell (HSC) activation and the underlying mechanisms in vitro and in vivo. Herein, we demonstrated that LPS treatment led to a dramatic increase in autophagosome formation and autophagic flux in LX-2 cells and HSCs, which was mediated through the AKT-MTOR and AMPK-ULK1 pathway. LPS significantly decreased the lipid content, including the lipid droplet (LD) number and lipid staining area in HSCs; pretreatment with macroautophagy/autophagy inhibitors or silencing ATG5 attenuated this decrease. Furthermore, lipophagy was induced by LPS through the autophagy-lysosomal pathway in LX-2 cells and HSCs. Additionally, LPS-induced autophagy further reduced retinoic acid (RA) signaling, as demonstrated by a decrease in the intracellular RA level and Rar target genes, resulting in the downregulation of Bambi and promoting the sensitization of the HSC's fibrosis response to TGFB. Compared with CCl injection alone, CCl plus LPS injection exaggerated liver fibrosis in mice, as demonstrated by increased Col1a1 (collagen, type I, α 1), Acta2, Tgfb and Timp1 mRNA expression, ACTA2/α-SMA and COL1A1 protein expression, and Sirius Red staining area, which could be attenuated by injection of an autophagy inhibitor. LPS also reduced lipid content in HSCs in vivo, with this change being attenuated by chloroquine (CQ) administration. In conclusion, LPS-induced autophagy resulted in LD loss, RA signaling dysfunction, and downregulation of the TGFB pseudoreceptor Bambi, thus sensitizing HSCs to TGFB signaling.

There are no effective medications for delaying the progress of Alzheimer's disease (AD), the most common neurodegenerative disease in the world. In this study, our results with C. elegans showed that rose essential oil (REO) significantly inhibited AD-like symptoms of worm paralysis and hypersensivity to exogenous 5-HT in a dose-dependent manner. Its main components of β-citronellol and geraniol acted less effectively than the oil itself. REO significantly suppressed Aβ deposits and reduced the Aβ oligomers to alleviate the toxicity induced by Aβ overexpression. Additionally, the inhibitory effects of REO on worm paralysis phenotype were abrogated only after skn-1 RNAi but not daf-16 and hsf-1 RNAi. REO markedly activated the expression of gst-4 gene, which further supported SKN-1 signaling pathway was involved in the therapeutic effect of REO on AD C. elegans. Our results provided direct evidence on REO for treating AD on an organism level and relative theoretical foundation for reshaping medicinal products of REO in the future.

K562 cells and peripheral blood mononuclear cells were treated with hydrogen peroxide (H 2 O 2 ) to determine the expression of Krüppel-like factor (KLF) 4. A full-length complementary DNA or an anti-sense oligonucleotide of KLF4 was transfected into cells, and expressions of B-cell lymphoma/leukemia-2 (bcl-2) and bcl-2-associated X (bax) proteins were analyzed. The results showed that H 2 O 2 treatment of cells resulted in an increase in KLF4 levels; KLF4 induced apoptosis and slowed cell growth, potentially resulting from upregulation of bax and down-regulation of bcl-2. Transcriptional activities on bcl-2 and bax were promoted following KLF4 overexpression potentially through KLF4 binding sites on corresponding promoters. All results indicate that KLF4 induces apoptosis in leukemia cells involving the bcl-2/bax pathway during H 2 O 2 stimulation, suggesting a potential mechanism for research on druginduced apoptosis.

Epoxyeicosatrienoic acids (EETs) are cytochrome P450 epoxygenase metabolites of arachidonic acid. EETs mediate numerous biological functions. In coronary arteries, they regulate vascular tone by the activation of smooth muscle large-conductance, calcium-activated potassium (BK Ca ) channels to cause hyperpolarization and relaxation. We developed a series of 14,