The STAT3 HIES mutation is a gain-of-function mutation that activates genes via AGG-element carrying promoters.

Cytokine or growth factor activated STAT3 undergoes multiple post-translational modifications, dimerization and translocation into nuclei, where it binds to serum-inducible element (SIE, 'TTC(N3)GAA')-bearing promoters to activate transcription. The STAT3 DNA binding domain (DBD, 320-494) mutation in hyper immunoglobulin E syndrome (HIES), called the HIES mutation (R382Q, R382W or V463Δ), which elevates IgE synthesis, inhibits SIE binding activity and sensitizes genes such as TNF-α for expression. However, the mechanism by which the HIES mutation sensitizes STAT3 in gene induction remains elusive. Here, we report that STAT3 binds directly to the AGG-element with the consensus sequence 'AGG(N3)AGG'. Surprisingly, the helical N-terminal region (1-355), rather than the canonical STAT3 DBD, is responsible for AGG-element binding. The HIES mutation markedly enhances STAT3 AGG-element binding and AGG-promoter activation activity. Thus, STAT3 is a dual specificity transcription factor that promotes gene expression not only via SIE- but also AGG-promoter activity.

[Effect of jiedu quyu zishen recipe on TLR9 signal pathway of murine macrophage cells].

OBJECTIVE: To explore efficacy enhancing and detoxification roles of Jiedu Quyu Zishen Recipe (JQZR) in treating systemic lupus erythematosus (SLE) by studying its effect on Toll like receptor 9 (TLR9) signal pathway of murine macrophage cells after JQZR stimulated CpG oligodeoxynucletide (CpG ODN). METHODS: Murine macrophage cells in vitro cultured were randomly divided into 4 groups, i.e., the blank serum group, the CpG ODN stimulus group, the CpG ODN + dexamethasone group, the CpG ODN + medicated serum group. Murine macrophage cells were collected after 24-h intervention. The expression of TLR9, myeloid differentiation factor 88 (MyD88), NF-KB, IFN-α mRNA were analyzed by RT-PCR. The expression of TLR9 and NF-κB protein were analyzed by Western blot. Changes of the NF-KB transcriptional activity were assayed by Dual-Luciferase reporter assay system. RESULTS: mRNA expressions of TLR9, MyD88, NF-κB, and IFN-α, protein expressions of TLR9 and NF-κB, and NF-κB transcriptional activities were enhanced, showing statistical difference when compared with those of the blank serum group (P <0. 05, P <0. 01). Compared with the CpG ODN stimulus group, mRNA expressions of MyD88, NF-κB, and IFN-α, the protein expression of NF-κB and the NF-κB transcriptional activities decreased in the CpG ODN + dexamethasone group with statistical difference (P <0. 01). Compared with the CpG ODN stimulus group, mRNA expressions of TLR9, MyD88, NF-κB, and IFN-α, protein expressions of TLR9 and NF-κB, and NF-κB transcriptional activities were decreased in CpG ODN+ medicated serum group with statistical difference (P <0. 01). CONCLUSION: Efficacy enhancing and detoxification roles of JQZR in treatment of SLE might be realized through regulating TLR9 signal pathways.

[Study on the regulation of Jiedu Quyu Zishen Recipe on glucocorticoid receptor alpha in the renal tissue of MRL/lpr mice].

OBJECTIVE: To explore the action mechanism of Jiedu Quyu Zishen Recipe (JQZR) on the signal transduction of glucocorticoid receptor alpha (GRalpha) in the renal tissue of MRL/lpr mice. METHODS: Thirty MRL/lpr mice were randomly divided into three groups, i.e., the model group, the Western medicine group, and the Chinese medicine group, 10 in each. Besides, another 10 Kunming mice was taken as the normal control group. The pathological changes of the renal tissue were observed using HE staining. The expression of GRalpha was analyzed using Real-time PCR and Western blot. The effects of JQZR on the binding power of GRalpha to cyclophilin A were detected using co-immunoprecipitation. RESULTS: The renal injury degree of MRL/lpr mice in the Western medicine group and the Chinese medicine group was alleviated. Compared with the model group, the relative quantitation of GRalpha mRNA and protein expressions in the renal tissue of mice in the Western medicine group decreased, while they increased in the Chinese medicine group, showing statistical difference (P < 0.01). JQZR could significantly elevate the binding potency of GRalpha to cyclophilin A. CONCLUSION: Up-regulating the expression of GRalpha and enhancing mutual actions of GRalpha and cyclophilin A was one of JQZR's effects on improving the lesion of the renal tissue.

The effects of Jieduquyuzishen prescription-treated rat serum on the BAFF/BAFF-R signal pathway.

Systemic lupus erythematosus (SLE) is a chronic inflammatory disease mainly characterized by B cell hyperactivity. Glucocorticoid (GC) is widely used in SLE for its potent anti-inflammatory and immunosuppressive effects. Despite its important clinical efficacy, high-dose or long-term use of GC can cause severe side effects, such as osteoporosis, osteonecrosis, cataracts, hyperglycemia, coronary heart disease and cognitive impairment. Our early clinical studies have shown that Jieduquyuzishen prescription (JP) can effectively reduce the adverse effects and improve the curative effect of GC in the treatment of SLE. The BAFF/BAFF-R signaling pathway plays an important role in the development of SLE and has been regarded as a potential target for the therapy of SLE. In this study, we attempt to investigate the effect of JP on the BAFF/BAFF-R signaling pathway to explore the mechanism of JP in reducing the toxicity and enhancing the efficacy of GC. YAC-1 cells, isolated rat peripheral blood lymphocytes, polymorphonuclear neutrophils and spleen lymphocytes were treated with drug-containing serum. The results of RT-PCR, Western blot and dual-luciferase reporter gene assays indicate that either JP or GC can inhibit the mBAFF-induced up-regulation of BAFF, BAFF-R, Bcl-2, IL-10 and NF-κB in YAC-1 cells and WEHI-231 cells. Furthermore, MTS, flow cytometry and CFSE results reveal that the proliferation and survival of lymphocytes activated by mBAFF are suppressed by JP, GC and their combination. Contrary to GC, JP can reduce the apoptosis and raise the survival of polymorphonuclear neutrophils and can't increase the apoptosis of the peripheral blood lymphocytes and spleen lymphocytes. Therefore, it is possible that JP can down-regulate the BAFF/BAFF-R signaling pathway as effectively as GC, which may result in the dosage reduction of GC, thus decreasing the toxicity and improving the efficacy of GC-based treatment of SLE.