Identification of pyrogallol from Awa-tea as an anti-allergic compound that suppresses nasal symptoms and IL-9 gene expression.

As the expression level of allergic disease sensitive genes are correlated with the severity of allergic symptoms, suppression of these gene expressions could be promising therapeutics. We demonstrated that protein kinase Cδ / heat shock protein 90-mediated H1R gene expression signaling and nuclear factor of activated T-cells (NFAT)-mediated IL-9 gene expression signaling are responsible for the pathogenesis of pollinosis. Treatment with Awa-tea combined with wild grape hot water extract suppressed these signaling and alleviated nasal symptoms in toluene-2,4-diisocyanate (TDI)-sensitized rats. However, the underlying mechanism of its anti-allergic activity is not elucidated yet. Here, we sought to identify an anti-allergic compound from Awa-tea and pyrogallol was identified as an active compound. Pyrogallol strongly suppressed ionomycin-induced up-regulation of IL-9 gene expression in RBL-2H3 cells. Treatment with pyrogallol in combination with epinastine alleviated nasal symptoms and suppressed up-regulation of IL-9 gene expression in TDI-sensitized rats. Pyrogallol itself did not inhibit calcineurin phosphatase activity. However, pyrogallol suppressed ionomycin-induced dephosphorylation and nuclear translocation of NFAT. These data suggest pyrogallol is an anti-allergic compound in Awa-tea and it suppressed NFAT-mediated IL-9 gene expression through the inhibition of dephosphorylation of NFAT. This might be the underlying mechanism of the therapeutic effects of combined therapy of pyrogallol with antihistamine. J. Med. Invest. 67 : 289-297, August, 2020.

Beneficial effect of 2'-acetylacteoside on ovariectomized mice via modulating the function of bone resorption.

2'-Acetylacteoside-(2'-AA), a bioactive constituent isolated from Cistanche deserticola, has been proven to possess a variety of important pharmacological effects, thus brought an increased amount of scientists' attention. As the extract of C. deserticola exhibited significant anti-osteoporotic bioactivity in our previous study, we proposed that 2'-AA maybe one of the responsibilities. As a result, 2'-AA (10, 20 and 40 mg/kg body weight/day) exhibited significant anti-osteoporotic effects on ovariectomized (OVX) mice after 12 weeks of oral administration, confirmed by the increased bone mineral density, enhanced bone strength and improved trabecular bone micro-architecture including bone mineral content, tissue mineral content, trabecular number, and trabecular separation of OVX mice. Moreover, the properties of bone resorption markers including cathepsin K, TRAP and deoxypyridinoline were significantly suppressed, whereas the activities of bone formation index like ALP and BGP as well as the weights of the body, uterus, and vagina were seemingly not influenced by 2'-AA intervention. Mechanistically, the above therapeutic effect of 2'-AA on bone resorption of OVX mice operated maybe mainly through RANKL/RANK/TRAF6-mediated NF-κB/NFATc1 pathway, which was confirmed by the down-regulated expressions of RANK, TRAF6, IκB kinase ß, NF-κB and NFATc1. Summarily, 2'-AA exhibited significant anti-osteoporotic activity and may be regarded as a promising anti-osteoporotic candidate for future clinical trial.

Ethyl Acetate Fraction from Dendropanax morbifera Leaves Increases T Cell Growth by Upregulating NF-AT-Mediated IL-2 Secretion.

Dendropanax morbifera Leveille (Araliaceae) is an endemic species that grows in Southwestern Korea and has been used as a folk medicine. Several studies reported that D. morbifera leaves have diverse therapeutic potentials. We found that the water extract of D. morbifera leaves increased the growth of EL-4 T cells. The water extract was divided into five fractions: [Formula: see text]-hexane, chloroform, ethyl acetate, [Formula: see text]-butanol, and water layers. The ethyl acetate (W-EA) fraction showed a more significant effect than the other fractions on the growth of EL-4 T cells, splenocytes, and isolated murine CD4[Formula: see text] T cells. We evaluated the W-EA fraction for its immunomodulatory effects focusing on T cell functions. First, we tested the effect of the W-EA fraction on the regulation of interleukin-2 (IL-2), a potent T cell growth factor. The W-EA fraction significantly increased IL-2 secretion in EL-4 T cells activated with phorbol 12-myristate 13-acetate (PMA) and ionomycin (Io). In addition, the W-EA fraction increased interferon-gamma (IFN-[Formula: see text] production in isolated murine splenocytes activated with Concanavalin A (ConA). Next, we examined the effect of the W-EA fraction on the regulation of transcriptional factors related to IL-2 production in T cells. The W-EA fraction significantly increased PMA/Io-induced promoter activity of a nuclear factor of activated T cells (NF-AT) in EL-4 T cells, but did not show any significant effects on the promoters of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-[Formula: see text]B). These results indicate that the W-EA fraction from water extract of D. morbifera leaves enhances IL-2 production at the transcriptional levels via the up-regulation of NF-AT in PMA/Io-activated EL-4 T cells.

Regulation of gene expression by NFAT transcription factors in hibernating ground squirrels is dependent on the cellular environment.

Calcineurin is a calmodulin-stimulated phosphatase that regulates the nuclear translocation of nuclear factor of activated T cell (NFAT) c1-4 through dephosphorylation. We believe that this mechanism plays various roles in the remodeling and maintenance of Ictidomys tridecemlineatus skeletal muscle. During hibernation, bouts of torpor and arousal take place, and squirrels do not lose muscle mass despite being inactive. Protein expression of Ca(2+) signaling proteins were studied using immunoblotting. A DNA-protein interaction ELISA technique was created to test the binding of NFATs in the nucleus to DNA probes containing the NFAT response element under environmental conditions reflective of those during hibernation. Calcineurin protein levels increased by 3.08-fold during torpor (compared to euthermic control), whereas calpain1 levels also rose by 3.66-fold during torpor. Calmodulin levels were elevated upon entering torpor. NFATc4 binding to DNA showed a 1.4-fold increase during torpor, and we found that this binding was further enhanced when 600 nM of Ca(2+) was supplemented. We also found that decreasing the temperature of ELISAs resulted in progressive decreases in the binding of NFATs c1, c3, and c4 to DNA. In summary, calmodulin and calpain1 appear to activate calcineurin and NFATc4 during torpor. NFAT binding to target promoters is affected by intranuclear [Ca(2+)] and environmental temperatures. Therefore, Ca(2+) signaling and temperature changes play key roles in regulation of the NFAT-calcineurin pathway in skeletal muscle of hibernating 13-lined ground squirrels over the torpor-arousal cycle, and they may contribute to the avoidance of disuse-induced muscle atrophy that occurs naturally in these animals.

Intermittent hypoxia-induced increases in reactive oxygen species activate NFATc3 increasing endothelin-1 vasoconstrictor reactivity.

Sleep apnea (SA), defined as intermittent respiratory arrest during sleep, is associated with increased incidence of hypertension, peripheral vascular disease, stroke, and sudden cardiac death. We have shown that intermittent hypoxia with CO2 supplementation (IH), a model for SA, increases blood pressure and circulating ET-1 levels, upregulates lung pre-pro ET-1 mRNA, increases vasoconstrictor reactivity to ET-1 in rat small mesenteric arteries (MA) and increases vascular reactive oxygen species (ROS). NFAT activity is increased in the aorta (AO) and MA of mice exposed to IH in an ET-1-dependent manner, and the genetic ablation of the isoform NFATc3 prevents IH-induced hypertension. We hypothesized that IH causes an increase in arterial ROS generation, which activates NFATc3 to increase vasoconstrictor reactivity to ET-1. In support of our hypothesis, we found that IH increases ROS in AO and MA. In vivo administration of the SOD mimetic tempol during IH exposure prevents IH-induced increases in NFAT activity in mouse MA and AO. We found that IH causes an NFATc3-dependent increase in vasoconstrictor reactivity to ET-1, accompanied by an increase in vessel wall [Ca²âº]. Our results indicate that IH exposure causes an increase in arterial ROS to activate NFATc3, which then increases vasoconstrictor reactivity and Ca²âº response to ET-1. These studies highlight a novel regulatory pathway, and demonstrate the potential clinical relevance of NFAT inhibition to prevent hypertension in SA patients.

TonEBP regulates hyperosmolality-induced arginine vasotocin gene expression in the chick (Gallus domesticus).

Arginine vasotocin (AVT) is expressed mainly in the paraventircular and supraoptic nuclei of the hypothalamus in chicken. This peptide is known to act as an antidiuretic hormone and its gene expression is stimulated by hyperosmolality. However, the transcription factors that regulate the AVT gene expression induced by hyperosmolality are still unknown. In this study, we examined the role of hyper-tonicity enhancer binding protein (TonEBP) in the transcriptional regulation of AVT gene in chicken. TonEBP mRNA expression levels increased at 1h after salt-loading treatment in the hypothalamus. This increase preceded that in AVT and c-fos mRNA expression. Intracerebroventricular injections of TonEBP antisense oligonucleotides, before the salt-loading treatment, prevented the increase in AVT gene expression. These results, all together, suggest that the transcription factor TonEBP may be involved in the regulation of AVT genes expression in response to a hyperosmotic environment in chicken.

The effect of water deprivation on the tonicity responsive enhancer binding protein (TonEBP) and TonEBP-regulated genes in the kidney of the Spinifex hopping mouse, Notomys alexis.

In desert rodents, the production of concentrated urine is essential for survival in xeric environments in order to conserve water. Reabsorption of water in the kidney is dependent on large osmotic gradients in the renal medulla. This causes the renal cells to be bathed in a hypertonic extracellular fluid that can compromise cellular function. In response to hypertonicity, kidney cells accumulate compatible, non-ionic osmolytes that lower the ionic strength within the cells to isotonic levels by replacing intracellular ionic electrolytes. The tonicity-responsive enhancer binding protein (TonEBP) is a transcription factor that regulates the expression of genes that encode proteins that catalyse the accumulation of compatible osmolytes. We investigated the expression of TonEBP mRNA and protein and compatible osmolyte genes in the Spinifex hopping mouse, Notomys alexis, an Australian desert rodent that produces a highly concentrated urine. TonEBP mRNA expression was unchanged after 3 days of water deprivation but was significantly increased after 7 and 14 days of water deprivation. Immunohistochemistry showed that during water deprivation TonEBP had translocated from the cytoplasm into the nucleus of cells in the renal medulla and papilla. In addition, 3, 7 and 14 days of water deprivation caused a significant increase in aldose reductase (AR), myo-inositol (SMIT), betaine/GABA (BGT-1) and taurine (TauT) transporter mRNA expression, which is indicative of an increase in TonEBP activity. In desert rodents, TonEBP regulation of gene transcription is probably an important mechanism to protect renal cells in the face of the large corticomedullary gradient that is required to concentrate urine and conserve water.

Suberosin inhibits proliferation of human peripheral blood mononuclear cells through the modulation of the transcription factors NF-AT and NF-kappaB.

BACKGROUND AND PURPOSE: Extracts of Plumbago zeylanica containing suberosin exhibit anti-inflammatory activity. We purified suberosin from such extracts and studied its effects on a set of key regulatory events in the proliferation of human peripheral blood mononuclear cells (PBMC) stimulated by phytohemagglutinin (PHA). EXPERIMENTAL APPROACH: Proliferation of PBMC in culture was measured by uptake of 3H-thymidine; production of cytokines and cyclins by Western blotting and RT-PCR. Transcription factors NF-AT and NF-kappaB were assayed by immunocytochemistry and EMSA. KEY RESULTS: Suberosin suppressed PHA-induced PBMC proliferation and arrested cell cycle progression from the G1 transition to the S phase. Suberosin suppressed, in activated PBMC, transcripts of interleukin-2 (IL-2), interferon-gamma (IFN-gamma), and cyclins D3, E, A, and B. DNA binding activity and nuclear translocation of NF-AT and NF-kappaB induced by PHA were blocked by suberosin. Suberosin decreased the rise in intracellular Ca2+ concentration ([Ca2+]i) in PBMC stimulated with PHA. Suberosin did not affect phosphorylation of p38 and JNK but did reduce activation of ERK in PHA-treated PBMC. Pharmacological inhibitors of NF-kappaB, NF-AT, and ERK decreased expression of mRNA for the cyclins, IL-2, and IFN-gamma and cell proliferation in PBMC activated by PHA. CONCLUSIONS AND IMPLICATIONS: The inhibitory effects of suberosin on PHA-induced PBMC proliferation, were mediated, at least in part, through reduction of [Ca2+]i, ERK, NF-AT, and NF-kappaB activation, and early gene expression in PBMC including cyclins and cytokines, and arrest of cell cycle progression in the cells. Our observations provide an explanation for the anti-inflammatory activity of P. zeylanica.