Limits...
IL-4-Stat6 signaling induces tristetraprolin expression and inhibits TNF-alpha production in mast cells.

Suzuki K, Nakajima H, Ikeda K, Maezawa Y, Suto A, Takatori H, Saito Y, Iwamoto I - J. Exp. Med. (2003)

Bottom Line: IL-4-Stat6 signaling induced TNF-alpha mRNA destabilization in an AU-rich element (ARE)-dependent manner, but did not affect TNF-alpha promoter activity.Furthermore, IL-4 induced the expression of tristetraprolin (TTP), an RNA-binding protein that promotes decay of ARE-containing mRNA, in mast cells by a Stat6-dependent mechanism, and the depletion of TTP expression by RNA interference prevented IL-4-induced down-regulation of TNF-alpha production in mast cells.These results suggest that IL-4-Stat6 signaling induces TTP expression and, thus, destabilizes TNF-alpha mRNA in an ARE-dependent manner.

View Article: PubMed Central - PubMed

Affiliation: Department of Internal Medicine II, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chiba City, Chiba 260-8670, Japan.

ABSTRACT
Increasing evidence has revealed that mast cell-derived tumor necrosis factor alpha (TNF-alpha) plays a critical role in a number of inflammatory responses by recruiting inflammatory leukocytes. In this paper, we investigated the regulatory role of interleukin 4 (IL-4) in TNF-alpha production in mast cells. IL-4 inhibited immunoglobulin E-induced TNF-alpha production and neutrophil recruitment in the peritoneal cavity in wild-type mice but not in signal transducers and activators of transcription 6 (Stat6)-deficient mice. IL-4 also inhibited TNF-alpha production in cultured mast cells by a Stat6-dependent mechanism. IL-4-Stat6 signaling induced TNF-alpha mRNA destabilization in an AU-rich element (ARE)-dependent manner, but did not affect TNF-alpha promoter activity. Furthermore, IL-4 induced the expression of tristetraprolin (TTP), an RNA-binding protein that promotes decay of ARE-containing mRNA, in mast cells by a Stat6-dependent mechanism, and the depletion of TTP expression by RNA interference prevented IL-4-induced down-regulation of TNF-alpha production in mast cells. These results suggest that IL-4-Stat6 signaling induces TTP expression and, thus, destabilizes TNF-alpha mRNA in an ARE-dependent manner.

Show MeSH

Related in: MedlinePlus

ARE in 3′UTR of TNF-α mRNA induces rapid decay of mRNA in Stat6VT expressing cells. (A) Schema of pTet-BBB ARETNF and pTet-BBB (28). (B) CFTL-15 cells were infected with MSCV-Stat6VT-IRES-Thy1.1 retrovirus or control MSCV-IRES-Thy1.1 retrovirus. Sorted Thy1.1+ cells were transfected with either pTet-BBB ARETNF or pTet-BBB in the presence of pTet-Off and G418-resistant clones were selected by limiting dilution. These clones were cultured in the absence of DOX for 4 h to resume transcription from pTet-BBB ARETNF or pTet-BBB, which was followed by the addition of 100 ng/ml DOX to block further transcription. At indicated times after the addition of DOX, total RNA was isolated and Taqman PCR analysis for rabbit β-globin and glyceraldehydes-3-phosphate dehydrogenase (as a control) was performed. Representative data from five independent experiments are shown.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2194141&req=5

fig6: ARE in 3′UTR of TNF-α mRNA induces rapid decay of mRNA in Stat6VT expressing cells. (A) Schema of pTet-BBB ARETNF and pTet-BBB (28). (B) CFTL-15 cells were infected with MSCV-Stat6VT-IRES-Thy1.1 retrovirus or control MSCV-IRES-Thy1.1 retrovirus. Sorted Thy1.1+ cells were transfected with either pTet-BBB ARETNF or pTet-BBB in the presence of pTet-Off and G418-resistant clones were selected by limiting dilution. These clones were cultured in the absence of DOX for 4 h to resume transcription from pTet-BBB ARETNF or pTet-BBB, which was followed by the addition of 100 ng/ml DOX to block further transcription. At indicated times after the addition of DOX, total RNA was isolated and Taqman PCR analysis for rabbit β-globin and glyceraldehydes-3-phosphate dehydrogenase (as a control) was performed. Representative data from five independent experiments are shown.

Mentions: Because it has been demonstrated that the ARE in the 3′UTR of TNF-α mRNA controls both mRNA stability and translation (27), next we examined the effect of Stat6 activation on the regulation of ARE-dependent mRNA stability using a more direct system established by Loflin et al. (28). CFTL-15 cells that were infected with Stat6VT retrovirus or control retrovirus were transfected with pTet-BBB ARETNF or pTet-BBB (Fig. 6 A) in the presence of pTet-Off vector. pTet-BBB ARETNF– or pTet-BBB–expressing cells were cultured in the absence of DOX for 4 h to resume transcription of rabbit β-globin from pTet-BBB ARETNF or pTet-BBB. After further transcription was blocked by adding DOX, the amount of rabbit β-globin mRNA was examined by Taqman PCR analysis (Fig. 6 B). Even in the absence of Stat6VT expression, the decay of rabbit β-globin mRNA was more rapid in pTet-BBB ARETNF-expressing cells than that in pTet-BBB–expressing cells (Fig. 6 B). Furthermore, the decay of rabbit β-globin mRNA was significantly enhanced by the expression of Stat6VT in pTet-BBB ARETNF-expressing cells (Fig. 6 B). On the other hand, the expression of Stat6VT did not affect the decay of rabbit β-globin mRNA in pTet-BBB–expressing cells (Fig. 6 B). These results indicate that Stat6 activation induces TNF-α mRNA destabilization in an ARE-dependent manner.


IL-4-Stat6 signaling induces tristetraprolin expression and inhibits TNF-alpha production in mast cells.

Suzuki K, Nakajima H, Ikeda K, Maezawa Y, Suto A, Takatori H, Saito Y, Iwamoto I - J. Exp. Med. (2003)

ARE in 3′UTR of TNF-α mRNA induces rapid decay of mRNA in Stat6VT expressing cells. (A) Schema of pTet-BBB ARETNF and pTet-BBB (28). (B) CFTL-15 cells were infected with MSCV-Stat6VT-IRES-Thy1.1 retrovirus or control MSCV-IRES-Thy1.1 retrovirus. Sorted Thy1.1+ cells were transfected with either pTet-BBB ARETNF or pTet-BBB in the presence of pTet-Off and G418-resistant clones were selected by limiting dilution. These clones were cultured in the absence of DOX for 4 h to resume transcription from pTet-BBB ARETNF or pTet-BBB, which was followed by the addition of 100 ng/ml DOX to block further transcription. At indicated times after the addition of DOX, total RNA was isolated and Taqman PCR analysis for rabbit β-globin and glyceraldehydes-3-phosphate dehydrogenase (as a control) was performed. Representative data from five independent experiments are shown.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2194141&req=5

fig6: ARE in 3′UTR of TNF-α mRNA induces rapid decay of mRNA in Stat6VT expressing cells. (A) Schema of pTet-BBB ARETNF and pTet-BBB (28). (B) CFTL-15 cells were infected with MSCV-Stat6VT-IRES-Thy1.1 retrovirus or control MSCV-IRES-Thy1.1 retrovirus. Sorted Thy1.1+ cells were transfected with either pTet-BBB ARETNF or pTet-BBB in the presence of pTet-Off and G418-resistant clones were selected by limiting dilution. These clones were cultured in the absence of DOX for 4 h to resume transcription from pTet-BBB ARETNF or pTet-BBB, which was followed by the addition of 100 ng/ml DOX to block further transcription. At indicated times after the addition of DOX, total RNA was isolated and Taqman PCR analysis for rabbit β-globin and glyceraldehydes-3-phosphate dehydrogenase (as a control) was performed. Representative data from five independent experiments are shown.
Mentions: Because it has been demonstrated that the ARE in the 3′UTR of TNF-α mRNA controls both mRNA stability and translation (27), next we examined the effect of Stat6 activation on the regulation of ARE-dependent mRNA stability using a more direct system established by Loflin et al. (28). CFTL-15 cells that were infected with Stat6VT retrovirus or control retrovirus were transfected with pTet-BBB ARETNF or pTet-BBB (Fig. 6 A) in the presence of pTet-Off vector. pTet-BBB ARETNF– or pTet-BBB–expressing cells were cultured in the absence of DOX for 4 h to resume transcription of rabbit β-globin from pTet-BBB ARETNF or pTet-BBB. After further transcription was blocked by adding DOX, the amount of rabbit β-globin mRNA was examined by Taqman PCR analysis (Fig. 6 B). Even in the absence of Stat6VT expression, the decay of rabbit β-globin mRNA was more rapid in pTet-BBB ARETNF-expressing cells than that in pTet-BBB–expressing cells (Fig. 6 B). Furthermore, the decay of rabbit β-globin mRNA was significantly enhanced by the expression of Stat6VT in pTet-BBB ARETNF-expressing cells (Fig. 6 B). On the other hand, the expression of Stat6VT did not affect the decay of rabbit β-globin mRNA in pTet-BBB–expressing cells (Fig. 6 B). These results indicate that Stat6 activation induces TNF-α mRNA destabilization in an ARE-dependent manner.

Bottom Line: IL-4-Stat6 signaling induced TNF-alpha mRNA destabilization in an AU-rich element (ARE)-dependent manner, but did not affect TNF-alpha promoter activity.Furthermore, IL-4 induced the expression of tristetraprolin (TTP), an RNA-binding protein that promotes decay of ARE-containing mRNA, in mast cells by a Stat6-dependent mechanism, and the depletion of TTP expression by RNA interference prevented IL-4-induced down-regulation of TNF-alpha production in mast cells.These results suggest that IL-4-Stat6 signaling induces TTP expression and, thus, destabilizes TNF-alpha mRNA in an ARE-dependent manner.

View Article: PubMed Central - PubMed

Affiliation: Department of Internal Medicine II, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chiba City, Chiba 260-8670, Japan.

ABSTRACT
Increasing evidence has revealed that mast cell-derived tumor necrosis factor alpha (TNF-alpha) plays a critical role in a number of inflammatory responses by recruiting inflammatory leukocytes. In this paper, we investigated the regulatory role of interleukin 4 (IL-4) in TNF-alpha production in mast cells. IL-4 inhibited immunoglobulin E-induced TNF-alpha production and neutrophil recruitment in the peritoneal cavity in wild-type mice but not in signal transducers and activators of transcription 6 (Stat6)-deficient mice. IL-4 also inhibited TNF-alpha production in cultured mast cells by a Stat6-dependent mechanism. IL-4-Stat6 signaling induced TNF-alpha mRNA destabilization in an AU-rich element (ARE)-dependent manner, but did not affect TNF-alpha promoter activity. Furthermore, IL-4 induced the expression of tristetraprolin (TTP), an RNA-binding protein that promotes decay of ARE-containing mRNA, in mast cells by a Stat6-dependent mechanism, and the depletion of TTP expression by RNA interference prevented IL-4-induced down-regulation of TNF-alpha production in mast cells. These results suggest that IL-4-Stat6 signaling induces TTP expression and, thus, destabilizes TNF-alpha mRNA in an ARE-dependent manner.

Show MeSH
Related in: MedlinePlus