Histone deacetylase 3 mediates allergic skin inflammation by regulating expression of MCP1 protein

We have shown the induction of histone deacetylase 3 (HDAC3) in antigen-stimulated rat basophilic leukemia cells via NF-κB. We investigated the role of HDAC3 in allergic skin inflammation. We used a BALB/c mouse model of triphasic cutaneous anaphylaxis (triphasic cutaneous reaction; TpCR) and passive cutaneous anaphylaxis (PCA) to examine the role of HDAC3 in allergic skin inflammation. Triphasic cutaneous reaction involved induction of HDAC3 and was mediated by HDAC3. HDAC3 showed an interaction with FcεRIβ. Trichostatin A (TSA), an inhibitor of HDAC(s), disrupted this interaction. Cytokine array analysis showed that the down-regulation of HDAC3 led to the decreased secretion of monocyte chemoattractant protein 1 (MCP1). FcεRI was necessary for induction of HDAC3 and MCP1. ChIP assays showed that HDAC3, in association with Sp1 and c-Jun, was responsible for induction of MCP1 expression. TSA exerted a negative effect on induction of MCP1. HDAC3 exerted a negative regulation on expression of HDAC2 via interaction with Rac1. The down-regulation of HDAC3 or inactivation of Rac1 induced binding of HDAC2 to MCP1 promoter sequences. TSA exerted a negative effect on HDAC3-mediated TpCR. The BALB/c mouse model of PCA involved induction of HDAC3 and MCP1. HDAC3 and MCP1 were necessary for PCA that involved ear swelling, enhanced vascular permeability, and angiogenesis. Recombinant MCP1 enhanced β-hexosaminidase activity and histamine release and also showed angiogenic potential. TSA exerted a negative effect on PCA. Our data show HDAC3 as a valuable target for the development of allergic skin inflammation therapeutics.     

Ln Is a Key Regulator of Leaflet Shape and Number of Seeds per Pod in Soybean

Narrow leaflet soybean (Glycine max) varieties tend to have more seeds per pod than broad leaflet varieties. Narrow leaflet in soybean is conferred by a single recessive gene, ln. Here, we show that the transition from broad (Ln) to narrow leaflet (ln) is associated with an amino acid substitution in the EAR motif encoded by a gene (designated Gm-JAGGED1) homologous to Arabidopsis JAGGED (JAG) that regulates lateral organ development and the variant exerts a pleiotropic effect on fruit patterning. The genomic region that regulates both the traits was mapped to a 12.6-kb region containing only one gene, Gm-JAG1. Introducing the Gm-JAG1 allele into a loss-of-function Arabidopsis jagged mutant partially restored the wild-type JAG phenotypes, including leaf shape, flower opening, and fruit shape, but the Gm-jag1 (ln) and EAR-deleted Gm-JAG1 alleles in the jagged mutant did not result in an apparent phenotypic change. These observations indicate that despite some degree of functional change of Gm-JAG1 due to the divergence from Arabidopsis JAG, Gm-JAG1 complemented the functions of JAG in Arabidopsis thaliana. However, the Gm-JAG1 homoeolog, Gm-JAG2, appears to be sub- or neofunctionalized, as revealed by the differential expression of the two genes in multiple plant tissues, a complementation test, and an allelic analysis at both loci.     

Inhibition of mitogen-activated kinase kinase kinase 3 activity through phosphorylation by the serum- and glucocorticoid-induced kinase 1

The mitogen-activated protein kinase kinase kinase 3 (MEKK3) is a member of the MAP kinase family whose cellular activity is elevated in response to growth factors, oxidative stress, and hyperosmolar conditions. MEKK3 regulates MKK3 and MKK5/6/7. MEKK3 is involved distinctively in the signal pathway for blocking cell proliferation and cell cycle progression, contradictory to the biological responses commonly associated with other members of MEKKs. Based information concerning the substrate specificity of serum- and glucocorticoid-induced kinase 1 (SGK1), R-x-R-x-x-(S/T)-phi, where phi indicates a hydrophobic amino acid, two putative phosphorylation sites (Ser(166) and Ser(337)) were found in MEKK3. It was shown that the recombinant MEKK3 protein and fluorescein-labeled MEKK3 peptides (FITC-(159)epRsRhlSVi(168) and FITC-(330)dpRgRlpSAd(339)) are phosphorylated by SGK1 in vitro. It was also observed that the intrinsic kinase activity of MEKK3 on Ser(189) of MKK3 (equivalent to Ser(207) of MKK6) decreased along with phosphorylation of Ser(166) and Ser(337) in MEKK3 in vitro and in vivo. Therefore, it is suggested that SGK1 inhibits MEKK3-MKK3/6 signal transduction by phosphorylation of MEKK3.     

Functional expression and production of human H-ferritin in Pichia pastoris

Human heavy chain ferritin (H-ferritin) was cloned from human heart cDNA library and expressed in Pichia pastoris. The H-ferritin transformant was cultivated by fed-batch and the cell mass reached about 52 g cell dry wt l^–1 after 150 h. In atomic absorption spectrometry analysis, intracellular content of iron in H-ferritin transformant was measured to 3038 ± 72 g g^–1 which was 9.6-fold more than that of control strain.     

HSP25 overexpression attenuates oxidative stress-induced apoptosis: roles of ERK1/2 signaling and manganese superoxide dismutase

HSP25 has been shown to induce resistance to radiation and oxidative stress; however, its exact mechanisms remain unclear. In the present study, a high concentration of H2O2 was found to induce DNA fragmentation in L929 mouse fibroblast cells, and HSP25 overexpression attenuated this phenomenon. To elucidate the mechanisms of H2O2-mediated cell death, ERK1/2, p38 MAPK, and JNK1/2 phosphorylation in the cells after treatment with H2O2 were examined. ERK1/2 and JNK1/2 were activated by H2O2; ERK1/2 activation was inhibited in HSP25-overexpressed cells, while JNK1/2 was indifferent. Inhibition of ERK1/2 activation by treatment of the cells with PD98059 or dominant-negative ERK2 transfection blocked H2O2-induced cell death; similarly treated HSP25-overexpressed cells were not at all affected. Moreover, inhibition of JNK1/2 by dominant-negative JNK1 or JNK2 transfection did not affect H2O2-mediated cell death in control cells. Dominant-negative Ras or Raf transfection inhibited H2O2-mediated ERK1/2 activation and cell death in control cells. On the contrary, HSP25-overexpressed cells did not show any differences. Upstream pathways of H2O2-mediated ERK1/2 activation and cell death involved both tyrosine kinase (PDGFbeta receptor and Src) and PKCdelta, while in HSP25-overexpressed cells these kinases did not respond to H2O2 treatment. Since HSP25 overexpression reduced reactive oxygen species (ROS), increased manganese superoxide dismutase (MnSOD) gene expression, and increased enzyme activity, involvement of MnSOD in HSP25-mediated attenuation of H2O2-mediated ERK1/2 activation and cell death was examined. Blockage of MnSOD with antisense oligonucleotides prevented DNA fragmentation and returned the ERK1/2 activation to the control level. Indeed, when MnSOD was overexpressed in L929 cells, similar to in HSP25-overexpressed cells, DNA fragmentation and ERK1/2 activation were reduced. From the above results, we suggest for the first time that reduced oxidative damage by HSP25 was due to MnSOD-mediated downregulation of ERK1/2.     

Serum bioactive lysophospholipids prevent TRAIL-induced apoptosis via PI3K/Akt-dependent cFLIP expression and Bad phosphorylation

Serum contains a variety of biomolecules, which play an important role in cell proliferation and survival. We sought to identify the serum factor responsible for mitigating tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis and to investigate its molecular mechanism. TRAIL induced effective apoptosis without serum, whereas bovine serum decreased apoptosis by suppressing cytochrome c release and caspase activation. Indeed, albumin-bound lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) inhibited TRAIL-induced apoptosis by suppressing caspase activation and cytochrome c release. LPA increased phosphatidylinositol 3-kinase (PI3K)-dependent Akt activation, cellular FLICE-inhibitory protein (cFLIP) expression, and Bad phosphorylation, resulting in inhibition of caspase-8 activation and Bad translocation to mitochondria. The antiapoptotic effect of LPA was abrogated by PI3K inhibitor, transfection with dominant-negative Akt, and specific downregulation of cFLIP expression using siRNA and further increased by siRNA-mediated suppression of Bad expression. Moreover, sera from ovarian cancer patients showed more protective effect against TRAIL-induced apoptosis than those from healthy donors, and this protection was suppressed by PI3K inhibitor. Our results indicate that albumin-bound LPA and S1P prevent TRAIL-induced apoptosis by upregulation of cFLIP expression and in part by Bad phosphorylation, through the activation of PI3K/Akt pathway.