Dexmedetomidine use in the ED for control of methamphetamine-induced agitation.

Background: Chemical restraint is often required to control agitation induced by methamphetamine. Dexmedetomidine is an α-2 adrenergic receptor agonist with sedative, analgesic, and sympatholytic properties. Its use in the emergency department (ED) to control methamphetamine-induced agitation has not been reported.

IL-21 Signaling in Immunity.

IL-21 is a type I cytokine produced by T cells and natural killer T cells that has pleiotropic actions on a wide range of immune and non-immune cell types. Since its discovery in 2000, extensive studies on the biological actions of IL-21 have been performed in vitro and in vivo. Recent reports describing patients with primary immunodeficiency caused by mutations of IL21 or IL21R have further deepened our knowledge of the role of this cytokine in host defense.

Cutting Edge: IL-1 Receptor Signaling is Critical for the Development of Autoimmune Uveitis.

IL-1β is a proinflammatory cytokine important for local and systemic immunity. However, aberrant production of this cytokine is implicated in pathogenic mechanisms of a number of inflammatory diseases, including Behçet's disease and age-related macular degeneration. In this study, we report the increased secretion of IL-1β in the retina by neutrophils, macrophages, and dendritic cells during ocular inflammation and show that loss of IL-1R signaling confers protection from experimental autoimmune uveitis.

IL-21-mediated non-canonical pathway for IL-1β production in conventional dendritic cells.

The canonical pathway for IL-1β production requires TLR-mediated NF-κB-dependent Il1b gene induction, followed by caspase-containing inflammasome-mediated processing of pro-IL-1β. Here we show that IL-21 unexpectedly induces IL-1β production in conventional dendritic cells (cDCs) via a STAT3-dependent but NF-κB-independent pathway. IL-21 does not induce Il1b expression in CD4(+) T cells, with differential histone marks present in these cells versus cDCs.

Opposing roles of STAT1 and STAT3 in IL-21 function in CD4+ T cells.

IL-21 is a type I cytokine essential for immune cell differentiation and function. Although IL-21 can activate several STAT family transcription factors, previous studies focused mainly on the role of STAT3 in IL-21 signaling. Here, we investigated the role of STAT1 and show that STAT1 and STAT3 have at least partially opposing roles in IL-21 signaling in CD4(+) T cells.

The cytokines IL-21 and GM-CSF have opposing regulatory roles in the apoptosis of conventional dendritic cells.

Interleukin-21 (IL-21) has broad actions on T and B cells, but its actions in innate immunity are poorly understood. Here we show that IL-21 induced apoptosis of conventional dendritic cells (cDCs) via STAT3 and Bim, and this was inhibited by granulocyte-macrophage colony-stimulating factor (GM-CSF). ChIP-Seq analysis revealed genome-wide binding competition between GM-CSF-induced STAT5 and IL-21-induced STAT3.

IL-21 promotes the pathologic immune response to pneumovirus infection.

IL-21 is a cytokine with pleiotropic actions, promoting terminal differentiation of B cells, increased Ig production, and the development of Th17 and T follicular helper cells. IL-21 is also implicated in the development of autoimmune disease and has antitumor activity. In this study, we investigated the role of IL-21 in host defense to pneumonia virus of mice (PVM), which initiates an infection in mice resembling that of respiratory syncytial virus disease in humans.

Diacylglycerol kinase ζ deficiency in a non-CD4(+) T-cell compartment leads to increased peanut hypersensitivity.

Peanut sensitization in diacylglycerol kinase zeta (DGKζ) deficient mice led to elevated peanut-IgE levels and severe anaphylaxis. DGKζ deficient CD4T cells did not account for the phenotype. Future studies will determine which immune lineage caused increased food hypersensitivity.

Negative regulation of mTOR activation by diacylglycerol kinases.

The engagement of TCR induces T-cell activation, which initiates multiple characteristic changes such as increase in cell size, cell division, and the production of cytokines and other effector molecules. The mammalian target of rapamycin (mTOR) regulates protein synthesis, transcription, cell survival, and autophagy. Critical roles of mTOR in T-cell activation and effector/memory differentiation have been revealed using chemical inhibitors or by genetic ablation of mTOR in T cells.

1alpha,25-Dihydroxyvitamin D3 inhibits transcriptional potential of nuclear factor kappa B in breast cancer cells.

1alpha,25-Dihydroxyvitamin D(3) (VD(3)), the biologically active form of vitamin D, may have either pro- or anti-inflammatory activities because of its diverse actions on nuclear factor kappa B (NF-kappaB). Previous studies indicated that VD(3) can either activate or inhibit NF-kappaB via Akt-induced I kappaB alpha phosphorylation and increase in I kappaB alpha synthesis respectively. At present, the relevant contribution of each mechanism has not been fully explored.

Diacylglycerol kinases in immune cell function and self-tolerance.

Both diacylglycerol (DAG) and phosphatidic acid (PA) are important second messengers involved in signal transduction from many immune cell receptors and can be generated and metabolized through multiple mechanisms. Recent studies indicate that diacylglycerol kinases (DGKs), the enzymes that catalyze phosphorylation of DAG to produce PA, play critical roles in regulating the functions of multiple immune cell lineages. In T cells, two DGK isoforms, alpha and zeta, inhibit DAG-mediated signaling following T-cell receptor engagement and prevent T-cell hyperactivation.

Synergistic control of T cell development and tumor suppression by diacylglycerol kinase alpha and zeta.

Diacylglycerol (DAG) kinases (DGKs) are a family of enzymes that convert DAG to phosphatidic acid (PA), the physiologic functions of which have been poorly defined. We report here that DGK alpha and zeta synergistically promote T cell maturation in the thymus. Absence of both DGKalpha and zeta (DGKalpha(-/-)zeta(-/-)) results in a severe decrease in the number of CD4(+)CD8(-) and CD4(-)CD8(+) single-positive thymocytes correlating with increased DAG-mediated signaling.

1,25-dihydroxyvitamin D3 induces biphasic NF-kappaB responses during HL-60 leukemia cells differentiation through protein induction and PI3K/Akt-dependent phosphorylation/degradation of IkappaB.

1,25-dihydroxyvitamin D(3) (VD(3)) induces differentiation in a number of leukemia cell lines and under various conditions is able to either stimulate or inhibit nuclear factor kappa B (NF-kappaB) activity. Here we report a time-dependent biphasic regulation of NF-kappaB in VD(3)-treated HL-60 leukemia cells. After VD(3) treatment there was an early approximately 4 h suppression and a late 8-72 h prolonged reactivation of NF-kappaB.

Schisandrol A from Schisandra chinensis reverses P-glycoprotein-mediated multidrug resistance by affecting Pgp-substrate complexes.

Recent studies have shown that dibenzocyclooctadiene lignans may reverse P-glycoprotein-mediated multidrug resistance (Pgp-MDR) in cancer cells; however, the mechanism of action remains unknown. Through screening of herbs, we found that schisandrol A (SCH) isolated from Fructus Schisandrae (the dried fruit of Schisandra chinensis (Turcz.) Baill.

Magnolol suppresses NF-kappaB activation and NF-kappaB regulated gene expression through inhibition of IkappaB kinase activation.

The mis-regulation of nuclear factor-kappa B (NF-kappaB) signal pathway is involved in a variety of inflammatory diseases that leds to the production of inflammatory mediators. Our studies using human U937 promonocytes cells suggested that magnolol, a low molecular weight lignan isolated from the medicinal plant Magnolia officinalis, differentially down-regulated the pharmacologically induced expression of NF-kappaB-regulated inflammatory gene products MMP-9, IL-8, MCP-1, MIP-1alpha, TNF-alpha. Pre-treatment of magnolol blocked TNF-alpha-induced NF-kappaB activation in different cell types as evidenced by EMSA.

Gomisin A alters substrate interaction and reverses P-glycoprotein-mediated multidrug resistance in HepG2-DR cells.

Through an extensive herbal drug screening program, we found that gomisin A, a dibenzocyclooctadiene compound isolated from Schisandra chinensis, reversed multidrug resistance (MDR) in Pgp-overexpressing HepG2-DR cells. Gomisin A was relatively non-toxic but without altering Pgp expression, it restored the cytotoxic actions of anticancer drugs such as vinblastine and doxorubicin that are Pgp substrates but may act by different mechanisms. Several lines of evidence suggest that gomisin A alters Pgp-substrate interaction but itself is neither a Pgp substrate nor competitive inhibitor.

Triptolide induces Bcl-2 cleavage and mitochondria dependent apoptosis in p53-deficient HL-60 cells.

Triptolide, a bioactive component of the Chinese medicinal herb Tripterygium wilfordii Hook F., induces p53-mediated apoptosis in cancer cells. This study demonstrated that triptolide activated an alternative p53-independent apoptotic pathway in HL-60 cells.

Honokiol inhibits TNF-alpha-stimulated NF-kappaB activation and NF-kappaB-regulated gene expression through suppression of IKK activation.

Honokiol, a small molecular weight lignan originally isolated from Magnolia officinalis, shows anti-angiogenic, anti-invasive and anti-proliferative activities in a variety of cancers. In this study, we investigated whether honokiol affects the transcription factor nuclear factor-kappa B (NF-kappaB) which controls a large number of genes involved in angiogenesis, metastasis and cell survival. We observed that the tumor necrosis factor-alpha (TNF-alpha)-induced NF-kappaB activation was blocked by honokiol in four different cancer cell lines as evidenced by EMSA.

Reversal of P-glycoprotein-mediated multidrug resistance by Alisol B 23-acetate.

Herbal drugs were screened for their activity in reversing multidrug resistance (MDR) in P-glycoprotein (P-gp) over-expressing cancer cells. Through bio-assay guided fractionation an active compound was isolated from Rhizoma Alismatis, the underground part of Alisma orientale and the chemical structure of the isolate compound was confirmed by HPLC, LC-MS and NMR as Alisol B 23-acetate (ABA). ABA restored the sensitivity of MDR cell lines HepG2-DR and K562-DR to anti-tumor agents that have different modes of action but are all P-gp substrates.

Betulinic acid enhances 1alpha,25-dihydroxyvitamin D3-induced differentiation in human HL-60 promyelocytic leukemia cells.

Betulinic acid (BA) is a pentacyclic triterpene found in a number of medicinal plants and has been shown to cause apoptosis in a number of cell lines. We report here that BA may also have an effect on HL-60 cell differentiation. BA was cytotoxic to HL-60 cells with an IC50 of 5.