Angiotensin converting enzyme 2 alleviates infectious bronchitis virus-induced cellular inflammation by suppressing IL-6/JAK2/STAT3 signaling pathway / 生物工程学报

The goal of this study was to investigate the regulatory effect of angiotensin converting enzyme 2 (ACE2) on cellular inflammation caused by avian infectious bronchitis virus (IBV) and the underlying mechanism of such effect. Vero and DF-1 cells were used as test target to be exposed to recombinant IBV virus (IBV-3ab-Luc). Four different groups were tested: the control group, the infection group[IBV-3ab-Luc, MOI (multiplicity of infection)=1], the ACE2 overexpression group[IBV-3ab Luc+pcDNA3.1(+)-ACE2], and the ACE2-depleted group (IBV-3ab-Luc+siRNA-ACE2). After the cells in the infection group started to show cytopathic indicators, the overall protein and RNA in cell of each group were extracted. real-time quantitative polymerase chain reaction (RT-qPCR) was used to determine the mRNA expression level of the IBV nucleoprotein (IBV-N), glycoprotein 130 (gp130) and cellular interleukin-6 (IL-6). Enzyme linked immunosorbent assay (ELISA) was used to determine the level of IL-6 in cell supernatant. Western blotting was performed to determine the level of ACE2 phosphorylation of janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3). We found that ACE2 was successfully overexpressed and depleted in both Vero and DF-1 cells. Secondly, cytopathic indicators were observed in infected Vero cells including rounding, detaching, clumping, and formation of syncytia. These indicators were alleviated in ACE2 overexpression group but exacerbated when ACE2 was depleted. Thirdly, in the infection group, capering with the control group, the expression level of IBV-N, gp130, IL-6 mRNA and increased significantly (P < 0.05), the IL-6 level was significant or extremely significant elevated in cell supernatant (P < 0.05 or P < 0.01); the expression of ACE2 decreased significantly (P < 0.05); protein phosphorylation level of JAK2 and STAT3 increased significantly (P < 0.05). Fourthly, comparing with the infected group, the level of IBV-N mRNA expression in the ACE2 overexpression group had no notable change (P > 0.05), but the expression of gp130 mRNA, IL-6 level and expression of mRNA were elevated (P < 0.05) and the protein phosphorylation level of JAK2 and STAT3 decreased significantly (P < 0.05). In the ACE2-depleted group, there was no notable change in IBV-N (P > 0.05), but the IL-6 level and expression of mRNA increased significantly (P < 0.05) and the phosphorylation level of JAK2 and STAT3 protein decreased slightly (P > 0.05). The results demonstrated for the first time that ACE2 did not affect the replication of IBV in DF-1 cell, but it did contribute to the prevention of the activation of the IL-6/JAK2/STAT3 signaling pathway, resulting in an alleviation of IBV-induced cellular inflammation in Vero and DF-1 cells.

[ effect of endurance training on MiR-155 expression, STAT3 gene expression, and interleukin 6 protein in mice with breast cancer]

Endurance training has an important role in the prevention and adjuvant therapy of breast cancer. The aim of the present study was to investigate the role of endurance training on miR-155 expression, signal transducer and activator of transcription-3 [STAT[3]] gene expression, and interleukin 6 [IL-6] protein in breast cancer tumor in mice. In this study, 16 female Balb/C mice were randomly divided into exercise-tumor [ET] and rest-tumor [RT] groups. The mice were oriented in the environment and one million estrogen-dependent breast cancer cells [MC4L2] were injected into each mouse. Subsequently, the ET group performed endurance exercise, 5 days per week for 6 weeks. Tumor volume was measured by a digital caliper weekly. Finally, the mice were sacrificed and tumor tissue was removed and kept in -70[degree]C. Then, RNA was extracted by the Trizol protocol and complementary DNA [cDNA] was synthesized according to guidelines of the Kit Company. Consequently, the real-time PCR method was performed and data was collected. Significant differences were observed between the ET and RT groups in the STAT[3] gene expression, miR-155 expression, and IL-6 protein [P < 0.05]. These results were consistent with tumor growth rate. Exercise can reduce miR-155 expression, STAT[3] gene expression, and IL-6 protein in tumor tissue. Due to the reduction in miR-155 expression, STAT[3] gene expression, and IL-6 protein in the ET group, it can be claimed that endurance training can be used as adjuvant therapy by decreasing of oncogenic and inflammation factors

p42/p44 mitogen-activated protein kinases inhibit atrial natriuretic peptide mRNA transcription in gp130-mediated hypertrophic ventricular myocytes

OBJECTIVE@#To understand the role of ANP mRNA transcription regulation in gp130-mediated cardiomyocyte hypertrophy, and the involved mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase (ERK, also called p42/p44 MAPK) signaling pathway.@*METHODS@#Isolated neonatal ventricular myocytes were treated with different concentrations of CT-1 (10(-9), 10(-8)and 10(-7)mol/L). MTT was used to analyze the viability and RT-PCR was used to detect ANP mRNA levels in cardiomyocyte. To inhibit p42/p44 MAPK activity in hypertrophic cardiomyocytes, the cells were pretreated with a specific MEK1 inhibitor.@*RESULTS@#CT-1 significantly induced ANP mRNA expression and the viability of cardiomyocytes in a dose- and time-dependent manner. Furthermore, blocking p42/p44 MAPK activity by the special MEK1 inhibitor upregulated the ANP mRNA.@*CONCLUSIONS@#p42/p44 MAPK have an important role in suppressing ANP mRNA transcription and cell activity in gp130-mediated hypertrophic ventricular myocytes.

Effects of leukemia inhibitory factor on gp130 expression and rate of metaphase II development during in vitro maturation of mouse oocyte

Leukemia inhibitory factor [LIF] is a 45-56 kDa glycoprotein that has an important role in proliferation and embryo implantation. Its effect on oocyte maturation and how to exert the function remained to be elucidated. Immature mice superovulated with human menopausal gonadotropin and germinal vesicle [GV] oocytes were obtained from ovary 48 hours after. GV oocytes were cultured in tissue culture medium 199 with 0, 100, 500 and 1,000 U/ml LIF. Cumulus expansion and in vitro maturation [IVM] rate were assessed after culture. For reverse transcriptase PCR, total RNA from GV and metaphase II [Mil] oocytes were extracted by Trizol reagent. The quantity and quality of RNA were determined by spectrophotometry and electrophoresis, respectively. Reverse transcription was performed by Super Script III reverse transcriptase with 1 micro g of total RNA followed by DNase I treatment and heat inactivation. Expression of gp130 was determined by RT-PCR. Our results showed that cumulus expansion was improved with 1,000 U/ml in culture medium compared to others. GV breakdown and Mil rate in groups with LIF were higher than control group and were dose dependant. In 1,000 U/ml, LIF rate of Mil was significantly higher than control group [P<0.05]. Our results also showed that gp130 is expressed neither in GV nor in Mil oocytes during IVM of mouse oocytes. gp130 is expressed in human oocyte but not in mouse. Our results suggest that in mouse, LIF could affect the oocyte via another receptor or via cumulus cells; however, further studies are warranted

gp130 is important for the normal morphogenesis of Meckel's cartilage and subsequent mandibular development

gp130-mediated signaling is involved in both chondrogenesis and osteogenesis, but its direct role in the formation of embryonic Meckel's cartilage and associated mandibular development has not yet been elucidated. In this study, we examined the influence of gp130 ablation on the developing mandibular Meckel's cartilage by evaluating the morphological and histological changes as well as the gene expression patterns in developing embryonic gp130-/- mice. The ablation of the gp130 gene showed no change in region-specific collagen mRNA expression except for a slight delay in its expression but caused shortened embryonic Meckel's cartilage, delayed hypertrophic chondrocyte maturation and subsequent bony replacement with characteristic bending of the intramandibular Meckel's cartilage. The bending of Meckel's cartilage led to a narrow mandibular arch at the rostral area with poor cortical plate formation. These findings indicate that gp130-mediated signaling is important for the normal morphogenesis of Meckel's cartilage and subsequent mandibular development.

Age related changes in Fas (CD95) and Fas ligand gene expression and cytokine profiles in healthy Indians.

Ageing in human and animal models show changes in many aspects of protective immunity, particularly lymphopoenia and progressive decline in immune functions leading to increased frequency of infection and neoplasia. However, the exact mechanism of these defects is still unclear. In this study, elderly subjects showed a decline in CD3+ and CD4+ T-cell subsets as well as serum IL-2 levels. Serum IL-6 was significantly raised while expression of its signaling receptor gp130 was significantly impaired in elderly as compared to the younger ones. Additionally, all the elderly individuals showed constitutive expression of Fas and FasL mRNA; however, none of the younger individuals expressed mRNA transcripts constitutively although induced expression was seen in both the groups. Similarly, frequency of Fas and FasL expressing CD4+ and CD8+ T-cell subsets were significantly (p < 0.001) higher in elderly subjects as compared to the younger ones. Elderly individuals also showed a significantly (p < 0.001) higher frequency of activation induced cell death (AICD). Since interaction of Fas with its cognate ligand (FasL) activates death inducing caspases leading to apoptosis, and gp130 induces anti-apoptotic signal through STAT-3 pathway, these results suggest that the decline in protective immune functions in aged individuals may be related to Fas and FasL mediated apoptosis of peripheral T-cell subsets.

Signaling pathways regulating self-renewal of mouse embryonic stem cells--review / 中国实验血液学杂志

Mouse embryonic stem cells (ES cells) are pluripotent in that they can give rise to almost all the cell types in vitro and in vivo. Also, they can sustain self-renewal in vitro owing to symmetrical mitosis, i.e., only the cell number increases while the daughter cells remain pluripotent. Self-renewal and pluripotency of ES cells are under stringent regulation of several signaling pathways. Activation of either JAK-STAT3 or PI3K, the downstream cascade of gp130, can maintain the self-renewal of ES cells, while phosphorylation of another gp130-related branch, SHP2-Ras-ERK, drives the differentiation. BMP2/4-mediated signaling is capable of suppressing the differentiation of ES cells in collaboration with activated JAK-STAT3 under serum free culture conditions. Other signaling such as Wnt also contributes to the self-renewal of ES cells. Generally, the network, which is composed of various signaling pathways, modulates the self-renewal and differentiation of mouse ES cells precisely. This review focuses on the role of gp130 in proliferation of mouse ES cells including inhibitory effect of JAK-STAT3 pathway activation on differentiation of mouse ES cells, maintenance effect of PI3K pathway activation on self-renewal of ES cells, promotive effect of SHP-2-Ras-ERK pathway activation on differentiation of ES cells, and influence of other signaling pathways on self-renewal of mouse ES cells, including maintenance effect of BMP combination with LIF under serum free culture conditions on self-renewal of ES cells and promotive effect of Wnt pathway activation on self-renewal of ES cells.

Effects of Chinese herbs for supplementing Shen and strengthening bone on IL-6 mediated myelogenic osteoclasts formation of ovariectomized rats in early stage / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the effect of Chinese herbs for supplementing Shen and strengthening bone (HB) on myelogenic osteoclasts formation, and gene expression of interleukin-6 (IL-6), IL-6 receptor (IL-6R) and gp130 in bone marrow.</p><p><b>METHODS</b>Seventy-two healthy female SD rats of 3 months, were randomly divided into three groups, 24 in the sham-operated group (A), 24 in the ovariectomized group (B) and 24 in the after ovariectomy HB treated group (C). Bone marrow cells of 6 rats from each group were respectively collected and cultured at four time points (2nd, 4th, 6th and 12th weeks after operation). After 6 days of culture, the bone marrow cells were differentiated by Wright-Giemsa stain and TRAP stain, and total RNA in them was extracted by TRIZOL.</p><p><b>RESULTS</b>Beginning from the 2nd week, the osteoclasts formation in Group B was higher than that in Group A (P < 0.05), and IL-6, IL-6R gene expression significantly increased in Group B (P < 0.05 or P < 0.01). These changes reached the peak in the 4th to 6th week, with the level maintained to the 12th week. As for comparison of Group B and C, the above-mentioned changes were significantly weakened in the latter (P < 0.05 or P < 0.01). No significant change of gp130 gene expression revealed in the whole course in either group.</p><p><b>CONCLUSION</b>HB could inhibit the myelogenic osteoclasts formation in ovariectomized rats, this effect may be correlated with, partially at least, its inhibitory effect on the over-expressed IL-6 and IL-6R gene expression in myelocytes after ovariectomy.</p>

Crosstalk between ERK1/2 and STAT3 in the modulation of cardiomyocyte hypertrophy induced by cardiotrophin-1 / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway and the extracellular signal-regulated kinases 1/2 (ERK1/2) pathway are the two major independent signal transduction pathways. However, it has recently been found that STAT3 may be negatively regulated by ERK1/2 in gp130-dependent signaling. Cardiotrophin-1 (CT-1), a potent novel hypertrophic cytokine, depends on gp130 to induce signaling and depends on STAT3 to exert hypertrophic effect. In this study, we examined whether STAT3 activity was negatively regulated by ERK1/2 during CT-1-induced signaling in rat cardiomyocytes and, if so, whether such crosstalk interfered with the hypertrophic effect of CT-1 and, furthermore, whether the mechanism underlying the crosstalk involved phosphorylation of serine 727 (S727) in STAT3.</p><p><b>METHODS</b>The activities of ERK1/2 and STAT3 were assessed by in-gel kinase assay and Western blot analysis, respectively. The role of S727 phosphorylation in the crosstalk between ERK1/2 and STAT3 was determined by a transient transfection study using a STAT3S727A mutant. Cardiomyocyte hypertrophy was evaluated by the cellular protein-to-DNA ratio and [(3)H]-leucine incorporation.</p><p><b>RESULTS</b>CT-1 simultaneously activated both ERK1/2 and STAT3 in rat cardiomyocytes. Inhibition of ERK1/2 by U0126 resulted in an increase of CT-1-induced tyrosine phosphorylation of STAT3 and, consequently, the protein-to-DNA ratio and [(3)H]-leucine incorporation. Transient transfection of the cells with STAT3S727A had no significant effect on CT-1-induced tyrosine phosphorylation of STAT3.</p><p><b>CONCLUSIONS</b>STAT3 is activated by CT-1 in rat cardiomyocytes, but full activation is mitigated by the simultaneous activation of ERK1/2. The inhibition of ERK1/2 increases the activity of STAT3, which, in turn, enhances the hypertrophic effect of CT-1. The crosstalk between ERK1/2 and STAT3 is independent of the phosphorylation of the S727 in STAT3. Such crosstalk may contribute to the development of adequate cardiac hypertrophy.</p>

Antisense oligonucleotide of rat gp130 blocked the inhibitory effect of rhIL-6 on proliferation of the rat acute myeloid leukemia cell line R2 in vitro cultures / 中国实验血液学杂志

The second nonligand binding chain of IL-6 receptor (IL-6R), the membrane glycoprotein with 130 kD mol wt (gp130), is responsible for the signal transduction of IL-6 biological activity. Our experiments indicated that the rat gp130 molecule, which was expressed in the rat acute myeloid leukemia cell line R2, could associate with the complex of rhIL-6 and membrane human IL-6R molecule and transduce the inhibition-inducing signal on R2 cells. In the present study, antisense oligonucleotides of rat gp130 were synthesized and uptaked into the R2 cells. Then the effects of the antisense or sense nucleic acids of rat gp130 on the inhibition induced by rhIL-6 in the R2 cell were investigated. Our results show that the antisense oligonucleotide of rat gp130 blocked the inhibitory effect of rhIL-6 on the R2 cells by (45 +/- 7)% at the optimal concentration

Study on the biological activity and molecular mechanism of IFNalpha on human myeloma cell line Sko-007 / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the biological activity and molecular mechanism of interferon alpha (IFNalpha) on human myeloma cell line Sko-007.</p><p><b>METHODS</b>The effect of IFNalpha on the growth of Sko-007 cells was measured by MTT assay. Cells cycle distribution and the expression of two IL-6 receptor chains (IL-6R and gp130) on Sko-007 cell surface in the absence or presence of IFNalpha were monitored by FACS analysis. The activation state of protein kinase ERK, which is involved in Ras/MAPK signal transduction pathway mediating cell survival and proliferation, and the expression of anti-apoptotic Bcl-2 family proteins-Bcl-2, Bcl-x(L) and Mcl-1 in Sko-007 cells with or without IFNalpha were determined by immunoblot assay.</p><p><b>RESULT</b>IFNalpha arrested Sko-007 cell cycle progression. After stimulation with IFNalpha, an obvious increase in G(0)/G(1) phase (41.1%-->84.1%) and decrease in S phase (57.1%-->13.3%) of Sko-007 cell cycle distribution can be observed. Moreover, the proliferation of Sko-007 cells was dramatically inhibited in the presence of IFNalpha, with a maximal inhibitory rate up to 88%. In addition, the expression of gp130 on cell surface, the activation of protein kinase ERK and the expression of Bcl-2 and Bcl-x(L) were all down-regualted in IFNalpha-stimulated Sko-007 cells.</p><p><b>CONCLUSION</b>The inhibitory effect of IFNalpha on the proliferation of Sko-007 cells was mediated by gp130 down-regulation, degradation of Bcl-2 family anti-apoptotic proteins and inhibition of ERK activation.</p>

Circulating Levels of Interleukin-6 and Soluble Interleukin-6 Receptor in Acute Asthma / 결핵

BACKGROUND: The recognition of bronchial asthma as an inflammatory disease led to a search for soluble markers that would be useful in assessing airway inflammation. Interleukin-6 (IL-6) is a representative proinflammatory cytokine that has been shown to be connected with various inflammatory diseases. IL-6 acts via specific receptors that consist of the IL-6 binding glycoprotein gp80 and the signal transducer gp130. In the search for markers of airway inflammation, we investigated the role of soluble interleukin-6 receptor (sIL-6R) and IL-6 in acute asthma. METHODS: Serum levels of sIL-6R and IL-6 were measured in 78 acute asthmatics, in 15 patients with asymptomatic asthma and in 10 healthy control subjects by a specific ELISA using a murine antihuman IL-6R, IL-6 mAb (Quantikine sIL-6R, IL-6). RESULTS: Serum levels of IL-6 in acute asthmatics significantly exeeded those of control subjects. Those of sIL-6R in acute asthmatics were also significantly increased compared to those of control subjects. The serum concentration of IL-6 obtained in acute asthmatics was elevated as compared with the asymptomatic asthmatics. However, Association between eosinophilic count / IgE and IL-6 / sIL-6R in acute asthma could not found. CONCLUSION: Our results suggest that IL-6 may be involved in the pathogenesis of acute asthma and serum levels of IL-6 and sIL-6R may reflect the severity of airway inflammation.