Delta(9)-Tetrahydrocannabinol (Delta(9)-THC) is the major psychoactive component of marijuana and elicits pharmacological actions via cannabinoid receptors. Anandamide (AEA) and 2-arachidonoyl-glycerol (2-AG) are endogenous ligands for cannabinoid receptors, which because of their structural similarities to arachidonic acid (AA), AEA, and 2-AG could serve as substrates for lipoxygenases and cyclooxygenases (COXs) that metabolize polyunsaturated fatty acids to potent bioactive molecules. In this study, we have compared the effects of Delta(9)-THC, AEA, 2-AG, and another cannabinoid agonist, indomethacin morpholinylamide (IMMA), on lipopolysaccharide (LPS)-induced NO, IL-6, and PGE(2) release from J774 macrophages. Delta(9)-THC, IMMA, and AEA diminish LPS-induced NO and IL-6 production in a concentration-dependent manner. 2-AG inhibits the production of IL-6 but slightly increases iNOS-dependent NO production. Delta(9)-THC and IMMA also inhibit LPS-induced PGE(2) production and COX-2 induction, while AEA and 2-AG have no effects. These discrepant results of 2-AG on iNOS and COX-2 induction might be due to its bioactive metabolites, AA and PGE(2), whose incubation cause the potentiation of both iNOS and COX-2 induction. On the contrary, the AEA metabolite, PGE(2)-ethanolamide, influences neither the LPS-induced NO nor IL-6 production. Taken together, direct cannabinoid receptor activation leads to anti-inflammatory action via inhibition of macrophage function. The endogenous cannabinoid, 2-AG, also serves as a substrate for COX-catalyzing PGE(2) production, which in turn modulates the action of CB2.

1 Although capsaicin analogs might be a potential strategy to manipulate inflammation, the mechanism is still unclear. In this study, the effects and action mechanisms of vanilloid analogs on iNOS and COX-2 expression were investigated in RAW264.7 macrophages. 2 Capsaicin and resiniferatoxin (RTX) can inhibit LPS-and IFN-g-mediated NO production, and iNOS protein and mRNA expression with similar IC 50 values of around 10 mM. 3 Capsaicin also transcriptionally inhibited LPS-and PMA-induced COX-2 expression and PGE 2 production. However, this effect exhibited a higher potency (IC 50 : 0.2 mM), and RTX failed to elicit such responses at 10 mM. 4 Interestingly, we found that capsazepine, a competitive TRPV1 antagonist, did not prevent the inhibition elicited by capsaicin or RTX. Nevertheless, it mimicked vanilloids in inhibiting iNOS/NO and COX-2/PGE 2 induction with an IC 50 value of 3 mM. RT -PCR and immunoblotting analysis excluded the expression of TRPV1 in RAW264.7 macrophages. 5 The DNA binding assay demonstrated the abilities of vanilloids to inhibit LPS-elicited NF-kB and AP-1 activation and IFN-g-elicited STAT1 activation. The reporter assay of AP-1 activity also supported this action. 6 The kinase assay indicated that ERK, JNK, and IKK activation by LPS were inhibited by vanilloids. 7 In conclusion, vanilloids can modulate the expression of inflammatory iNOS and COX-2 genes in macrophages through interference with upstream signalling events of LPS and IFN-g. These findings provide new insights into the potential benefits of the active ingredient in hot chilli peppers in inflammatory conditions.

Pluripotent-cell-derived cardiomyocytes have great potential for use in research and medicine, but limitations in their maturity currently constrain their usefulness. Here, we report a method for improving features of maturation in murine and human embryonic-stem-cell-derived cardiomyocytes (m/hESC-CMs). We found that coculturing m/hESC-CMs with endothelial cells improves their maturity and upregulates several microRNAs. Delivering four of these microRNAs, miR-125b-5p, miR-199a-5p, miR-221, and miR-222 (miR-combo), to m/hESC-CMs resulted in improved sarcomere alignment and calcium handling, a more negative resting membrane potential, and increased expression of cardiomyocyte maturation markers. Although this could not fully phenocopy all adult cardiomyocyte characteristics, these effects persisted for two months following delivery of miR-combo. A luciferase assay demonstrated that all four miRNAs target ErbB4, and siRNA knockdown of ErbB4 partially recapitulated the effects of miR-combo. In summary, a combination of miRNAs induced via endothelial coculture improved ESC-CM maturity, in part through suppression of ErbB4 signaling.

The polysaccharide from Ganoderma lucidum (PS‐G) has been reported to enhance immune responses and to elicit antitumor effects. In our previous study, we found that PS‐G efficiently inhibited spontaneously and Fas‐enhanced neutrophil apoptosis when cultured in vitro. Since phagocytosis and chemotaxis play essential roles in host defense mediated by neutrophils, it is of great interest to know the effect of PS‐G on these two cell functions, and the molecular events leading to these actions. Using latex beads and heat‐inactive Escherichia coli serving as particles for neutrophil engulfment, we found that PS‐G is able to enhance phagocytic activity of human primary neutrophils and neutrophilic‐phenotype cells differentiated from all trans retinoic acid‐treated HL‐60 cells. Chemotactic assay using Boyden chamber also revealed the ability of PS‐G to increase neutrophil migration. Exposure of neutrophils to PS‐G time dependently caused increases in protein kinase C (PKC), p38 mitogen‐activated protein kinase (MAPK), Hck, and Lyn activities. Results with specific kinase inhibitors indicate that phagocytic action of PS‐G was reduced by the presence of wortmannin (Phosphatidylinositol 3‐kinase, PI3K inhibitor), pyrazolpyrimidine 2 (Src‐family tyrosine kinase inhibitor), Ro318220 (PKC inhibitor), and SB203580 (p38 MAPK inhibitor), but not by PD98059 (mitogen‐activated protein/ERK kinase inhibitor). Moreover, chemotactic action of PS‐G requires the activities of PI3K, p38 MAPK, Src tyrosine kinases and PKC. All these results demonstrate the abilities of PS‐G to enhance neutrophil function in phagocytosis and chemotaxis, and further provide evidence to strengthen the beneficial remedy of G. lucidum in human to enhance defense system. British Journal of Pharmacology (2003) 139, 289–298. doi:

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