BACKGROUNDInterleukin-13 (IL-13) is recognized to be a key modulator in the pathogenesis of Th2-induced allergic inflammation. Transcription factors GATA3 and NFAT1 have been both implicated in the regulation of Th2 cytokines. We previously demonstrated the GATA3-NFAT1 association during human T cell activation. However, the function of the GATA3-NFAT1 complex in Th2 cytokines regulation is still unknown. Small interference RNA (siRNA) was constructed to knock down GATA3 expression in Hut-78 cells to investigate the possible role of GATA3-NFAT1 complex in IL-13 transcription.

METHODSCells were stimulated with anti-CD3 plus anti-CD28 antibodies to mimic in vivo antigen-mediated co-stimulation; the expression of IL-13 mRNA was determined by real-time PCR; chromation immunoprecipitation (CHIP) assay was employed to investigate the NFAT1 binding to IL-13 promoter.

RESULTSGATA3 siRNA suppressed the expression of GATA3 both in mRNA and protein levels in Hut-78 cells. The binding of NFAT1 to IL-13 promoter was inhibited by GATA3 siRNA in activated T cells, which was followed by the reduction of IL-13 transcription.

CONCLUSIONGATA3-NFAT1 complex may play an important role in the regulation of IL-13 transcription in human T cells.

Cells, Cultured ; GATA3 Transcription Factor ; antagonists & inhibitors ; genetics ; Humans ; Interleukin-13 ; genetics ; NFATC Transcription Factors ; metabolism ; Promoter Regions, Genetic ; RNA, Small Interfering ; genetics ; T-Lymphocytes ; metabolism ; Transfection

OBJECTIVEThis study investigated the role and mechanism of calcineurin (CaN)-nuclear factor of activated T cells (NFAT) pathway in the myoblast apoptosis induced by cyclic tensile strain.

METHODSMyoblasts were cultured using an in vitro-mechanical stimulation model and imposed with tension for different hours with a multi-channel cell stress loading system. Cyclosporine (CsA) was used as CaN inhibitor to clarify the role of CaN in the apoptosis induced by cyclic stress. Hochest 33258 staining and flow cytometry detection were performed to detect the apoptotic cells. Real-time polymerase chain reaction was conducted to detect the mRNA expression of CaN and NFAT. Protein levels of NFAT3 were evaluated by Western blot.

RESULTSThe apoptosis rate increased with the extension of loading time. The mRNA expression of the CaN subunits, CnA and CnB, and the protein levels of NFAT3 also increased. When the myoblasts were incubated with CsA, the apoptosis rate decreased, the mRNA expression of CnA and NFAT3 significantly decreased, and the NFAT3 protein expression levels became significantly lower than those of the groups without CsA.

CONCLUSIONContinuous cyclic tensile stress can induce myoblast apoptosis. The CaN-NFAT signaling pathway may be involved in the cyclic stretch-induced apoptosis of myoblasts.

Apoptosis ; Calcineurin ; genetics ; Cyclosporine ; Flow Cytometry ; Myoblasts ; physiology ; NFATC Transcription Factors ; metabolism ; Real-Time Polymerase Chain Reaction ; Signal Transduction ; T-Lymphocytes

BACKGROUNDHow the transcriptional factors regulated the innate and adaptive immune system in pregnancy and pre-eclampsia are less understood. Nevertheless, what the plasma work in the development of this disease was not sure. The present study was design to evaluate what the transcriptional factors change in innate and adaptive immune system and what the plasma do in this filed.

METHODSPeripheral blood mononuclear cells (PBMC) from non-pregnant women (n = 18), women with clinically normal pregnancies (n = 23) and women with pre-eclampsia (n = 20) were separated from peripheral blood to isolate monocytes and T cells. The purity of monocytes and T cells were analysed by flow cytometry. Monocytes and T cells were stimulated in either lipopolysaccharides (LPS) or phorbol-myristate-acetate (PMA), respectively. Transcription Factor Arrays were used to screen the transcription factors of interest in comparing of different groups. PBMC were isolated from another 8 non-pregnant samples were co-incubated with different groups of plasma. Polymerase chain reaction (PCR) was performed using whole cell extractions of the samples.

RESULTSNuclear factor of activated T-cells-1 (NFAT-1), signal transducers and activators of transcription-1 (STAT-1) and activator protein-1 (AP-1) are up-regulated in monocytes in pregnancy and more so in pre-eclampsia. On the the contrary, NFAT-1, STAT-1 and AP-1 are down-regulated in T cells in pregnancy and more so in pre-eclampsia. A reduction was observed in interferon (IFN)-γ, interleukin (IL)-12 and IL-4 expression in T cells incubated with pre-eclamptic plasma. An elevation was observed in tumor necrosis factor (TNF)-α, IL-1 and IL-12 expression in monocytes incubated with pre-eclamptic plasma.

CONCLUSIONSInnate immunity is over activated and adaptive immunity is over suppressed in the development of pre-eclampsia. NFAT-1, STAT-1 and AP-1 might be the central transcription factors in the pathogenesis of pre-eclampsia. They induced some changes in plasma and "educate" the monocytes and T cells for relevant cytokine production. Successful completion of this study will enhance our understanding of pre-eclampsia and will discover new knowledge beyond pregnancy. The work will inform future therapies for the treatment of a wide range of condition such as transplantation immunology and a wide range of immune and inflammatory conditions.

Adult ; Female ; Humans ; Immunity, Innate ; physiology ; Interferon-gamma ; metabolism ; Interleukin-12 ; metabolism ; Interleukin-4 ; metabolism ; Leukocytes, Mononuclear ; metabolism ; Male ; NFATC Transcription Factors ; genetics ; metabolism ; Pre-Eclampsia ; immunology ; metabolism ; Pregnancy ; STAT1 Transcription Factor ; genetics ; metabolism ; Transcription Factor AP-1 ; genetics ; metabolism ; Transcription Factors ; genetics ; metabolism ; Young Adult

Adseverin is a Ca2+-dependent actin filament-severing protein that has been reported to regulate exocytosis via rearrangements of the actin cytoskeleton in secretory cells. However, the role of adseverin in bone cells has not yet been well characterized. Here, we investigated the role of adseverin in osteoclastogenesis using primary osteoclast precursor cells. Adseverin expression was upregulated during RANKL (receptor activator of nuclear factor-kappaB ligand)-induced osteoclast differentiation. Moreover, genetic silencing of adseverin decreased the number of osteoclasts generated by RANKL. Adseverin knockdown also suppressed the RANKL-mediated induction of nuclear factor of activated T-cell c1 (NFATc1), which is a key transcription factor in osteoclastogenesis. In addition, adseverin knockdown impaired bone resorption and the secretion of bone-degrading enzymes from osteoclasts. These effects were accompanied by decreased NFATc1 expression and the activation of nuclear factor-kappaB. Collectively, our results indicate that adseverin has a crucial role in osteoclastogenesis by regulating NFATc1.
Active Transport, Cell Nucleus ; Animals ; Bone Resorption/genetics/metabolism/pathology ; Cell Differentiation ; Cells, Cultured ; Female ; Gelsolin/genetics/*metabolism ; Gene Knockdown Techniques ; Humans ; Mice, Inbred ICR ; NF-kappa B/metabolism ; NFATC Transcription Factors/*metabolism ; Osteoclasts/*cytology/metabolism/pathology ; RANK Ligand/*metabolism

To screen NFAT antagonistic drugs and research signal transduction pathway related to NFAT. Four recombinant vectors were constructed. Each consists of three tandem copies of the human IL-2 distal NFAT-AP1 binding site in the context of the minimal IL-2 enhancer, either the sequence from -326 - +46 or the sequence from -89 - +46 (containing only the TATA box), driving a luciferase reporter gene or a destabilized enhanced green fluorescence protein (d2EGFP) reporter gene, respectively. Transient transfection of Jurkat cells was achieved by electroporation with 5 - 10 microg of the above plasmid and one pulse at 200V, 65ms. Plasmid pEFBos-mNFAT1 constitutively expressing murine full length NFAT1 protein was used for transient cotransfection. The results showed that neither of non-stimulation nor PMA or ionomycin stimulation alone could activate the reporter gene except PMA plus ionomycin costimulation. Furthermore, overexpressed murine NFAT1 augmented the activation of either IL-2 promoter or NFAT-AP1 enhancer drived reporter gene compared to the endogenous did. However, the reporter gene expression was nearly completely inhibited by pretreatment for 1h with FK506 at 5 microg/mL and then stimulation for 6-12h with PMA plus ionomycin in the presence of FK506. These findings indicated that such a transient Jurkat cell model offered a potential platform for preliminary screening of FK506 or CsA-like immunosuppressive agents.
Animals ; Drug Evaluation, Preclinical ; Enhancer Elements, Genetic ; genetics ; Green Fluorescent Proteins ; genetics ; Humans ; Immunosuppressive Agents ; pharmacology ; Interleukin-2 ; genetics ; Jurkat Cells ; Luciferases ; genetics ; metabolism ; Mice ; Models, Biological ; NFATC Transcription Factors ; genetics ; metabolism ; Promoter Regions, Genetic ; Signal Transduction ; Tacrolimus ; pharmacology

OBJECTIVETo discuss the effect of Drynariae Rhizoma's naringin on osteoclasts induced by mouse monocyte RAW264.7.

METHODRAW264.7 cells were induced by 100 μg x L(-1) nuclear factor-κB receptor activator ligand (RANKL) and became mature osteoclasts, which were identified through TRAP specific staining and bone resorption. MTT method was sued to screen and inhibit and the highest concentration of osteoclasts. After being cultured with the screened medium containing naringin for 5 days, positive TRAP cell counting and bone absorption area analysis were adopted to observe the effect of naringin on the formation of osteoclast sells and the bone absorption function. The osteoclast proliferation was measured by flow cytometry. The effects of RANK, TRAP, MMP-9, NFATc1 and C-fos mRNA expressions on nuclear factor-κB were detected by RT-PCR.

RESULTNaringin could inhibit osteoclast differentiation, bone absorption function and proliferation activity of osteoclasts, significantly down-regulate RANK, TRAP, MMP-9 and NFATc1 mRNA expressions in the osteoclast differentiation process, and up-regulate the C-fos mRNA expression.

CONCLUSIONNaringin could inhibit osteoclast differentiation, proliferation and bone absorption function. Its mechanism may be achieved by inhibiting the specific gene expression during the osteoclast differentiation process.

Acid Phosphatase ; metabolism ; Animals ; Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Flavanones ; pharmacology ; Isoenzymes ; metabolism ; Matrix Metalloproteinase 9 ; genetics ; Mice ; NFATC Transcription Factors ; genetics ; Osteoclasts ; cytology ; drug effects ; Tartrate-Resistant Acid Phosphatase

Viral proteins of gamma-2 herpesviruses, such as LMP2A of Epstein Barr virus (EBV) and Tip of herpesvirus saimiri (HVS) dysregulate lymphocyte signaling by interacting with Src family kinases. K15 open reading frame of Kaposi's sarcoma associated herpesvirus (KSHV), located at the right end of the viral genome, encodes several splicing variants differing in numbers of transmembrane domains. Previously, we demonstrated that the cytoplasmic tail of the K15 protein interfered with B cell receptor signal transduction to cellular tyrosine phosphorylation and calcium mobilization. However, the detailed mechanism underlying this phenomenon was not understood. In the C-terminal cytoplasmic region of K15, putative binding domains for Src-SH2 and -SH3 were identified. In this study, we attempted to characterize these modular elements and cellular binding protein(s) by GST pull down and co-immunoprecipitation assays. These studies revealed that K15 interacted with the major B cell tyrosine kinase Lyn. In vitro kinase and transient co-expression assays showed that the expression of K15 protein resulted in activation of Lyn kinase activity. In addition, GST pull down assay suggested that the SH2 domain of Lyn alone was necessary for interaction with the C-terminal SH2B (YEEV) of K15, but the addition of Lyn SH3 to the SH2 domain increases the binding affinity to K15 protein. The data from luciferase assays indicate that K15 expression in BJAB cells induced NFAT and AP1 activities. The tyrosine residue in the C-terminal end of K15 required for the Lyn interaction appeared to be essential for NFAT/AP1 activation, highlighting the significance of the C-terminal SH2B of K15 as a modular element in interfering with B lymphocyte signaling through interaction with Lyn kinase.
Cell Line ; Herpesvirus 8, Human/genetics/*metabolism ; Humans ; Immunoblotting ; Immunoprecipitation ; Membrane Proteins/genetics/*metabolism ; NFATC Transcription Factors/genetics/*metabolism ; Phosphorylation ; Protein Binding ; Sarcoma, Kaposi/virology ; Transcription Factor AP-1/genetics/*metabolism ; Transfection ; Viral Proteins/genetics/*metabolism ; src-Family Kinases/genetics/*metabolism

Platinum nanoparticles (PtNP) exhibit remarkable antioxidant activity. There is growing evidence concerning a positive relationship between oxidative stress and bone loss, suggesting that PtNP could protect against bone loss by modulating oxidative stress. Intragastric administration of PtNP reduced ovariectomy (OVX)-induced bone loss with a decreased level of activity and number of osteoclast (OC) in vivo. PtNP inhibited OC formation by impairing the receptor activator of nuclear factor-kappaB ligand (RANKL) signaling. This impairment was due to a decreased activation of nuclear factor-kappaB and a reduced level of nuclear factor in activated T-cells, cytoplasmic 1 (NFAT2). PtNP lowered RANKL-induced long lasting reactive oxygen species as well as intracellular concentrations of Ca2+ oscillation. Our data clearly highlight the potential of PtNP for the amelioration of bone loss after estrogen deficiency by attenuated OC formation.
Animals ; Metal Nanoparticles/*administration & dosage ; Mice ; Mice, Inbred C57BL ; NFATC Transcription Factors/metabolism ; *Osteoclasts/drug effects/physiology ; Osteoporosis/drug therapy ; Ovariectomy/adverse effects ; Oxidative Stress/drug effects ; Platinum/*administration & dosage ; *RANK Ligand/genetics/metabolism ; Reactive Oxygen Species/metabolism ; Signal Transduction

OBJECTIVETo investigate whether the decrease in expression of interleukin-2 (IL-2) after trauma is associated with changes in DNA binding activity of nuclear factor of activated T cells (NFAT) and activator protein-1 (AP-1).

METHODSMice with closed impact injury with fracture in both hind limbs were adopted as the trauma model. Spleen lymphocytes were isolated from traumatized mice and stimulated with Con-A. Culture supernatants were assayed for IL-2 activity, and total RNA was extracted from spleen lymphocytes and assayed for IL-2 mRNA. DNA binding activity of NFAT and AP-1 were measured by electrophoretic mobility shift assay (EMSA). The expression of c-Fos, c-Jun and JunB proteins was determined by the Western blot analysis.

RESULTSDNA binding activity of NFAT and AP-1 gradually decreased to a minimum of 41% and 49%, respectively, of the control on the 4th day after injury, which was closely followed by the decline in IL-2 activity and IL-2 mRNA. A decrease in the expression of c-Fos on the 1st and 4th day after trauma had no significant effect on c-Jun expression; the increase in expression of JunB was only on the 1st day after injury.

CONCLUSIONDecreased IL-2 expression is, at least in part, due to a decline in the activation of NFAT and AP-1 in traumatized mice. The decline in DNA binding activity of NFAT and AP-1 is partly due to a trauma-induced block in the expression of c-Fos.

Animals ; Cell Nucleus ; chemistry ; DNA ; metabolism ; DNA-Binding Proteins ; metabolism ; Electrophoretic Mobility Shift Assay ; Female ; Interleukin-2 ; analysis ; genetics ; Male ; Mice ; NFATC Transcription Factors ; Nuclear Proteins ; Proto-Oncogene Proteins c-fos ; analysis ; Proto-Oncogene Proteins c-jun ; analysis ; RNA, Messenger ; analysis ; Transcription Factor AP-1 ; metabolism ; Transcription Factors ; metabolism

OBJECTIVETo explore the effect of DNAX-associated protein 12 (DAP12) pathway on the transformation from mouse monocytes RAW264.7 to osteoclasts induced by tensile strain.

METHODSDAP12shRNA plasmid was constructed and introduced to RAW264.7 cells. Then we supplied tensile strain to RAW264.7 cells by four-point bending system. The mRNA or protein expression of DAP12, tartrate-resistant acid phosphatase (TRAP), tyrosine kinases Btk and Tec and nuclear facior of activated T cells 1 (NFATc1) was measured by reverse transcription PCR (RT-PCR) and Western blotting respectively.

RESULTSThe expression of DAP12 mRNA (0.112 ± 0.025) and protein (0.193 ± 0.015) both declined sharply after plasmid being introduced into monocytes RAW264.7 (P < 0.05). After silencing DAP12 expression in RAW264.7 cells by RNA interference, tensile strain-induced TRAP mRNA expression of RAW264.7 cells increased at 6 h (0.671 ± 0.031) and 12 h (0.800 ± 0.043) (P < 0.05), but it was weaker than non-RNA-interference-groups at each time point (P < 0.05). After silencing DAP12 expression in RAW264.7 cells by RNA interference, the expressions of Btk, Tec, NFATc1 increased as time passed (6, 12 h) (P < 0.05), but the expressions on corresponding time decreased sharply compared with those in control groups (P < 0.05).

CONCLUSIONSDAP12 pathway play an important role in regulating osteoclast differentiation induced by tensile strain.

Acid Phosphatase ; genetics ; metabolism ; Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Animals ; Cell Differentiation ; Cell Line ; Gene Expression Regulation ; Gene Silencing ; Isoenzymes ; genetics ; metabolism ; Mice ; Monocytes ; cytology ; metabolism ; NFATC Transcription Factors ; metabolism ; Osteoclasts ; cytology ; Plasmids ; Protein-Tyrosine Kinases ; metabolism ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; Signal Transduction ; Tartrate-Resistant Acid Phosphatase ; Tensile Strength