Project description:Tristetraprolin (TTP) binds to specific AU-rich elements in the 3'UTR of certain transcripts and regulates post-transcriptional gene expression by increasing the rate of mRNA turnover. In this study, we evaluated the effects of TTP deficiency on the overall gene expression of spleen tissue, in order to discover tissue specific targets of TTP under normal physiologic conditions. We utilized "Triple KO" (Zfp36-/-/TNFR1-/-/TNFR2-/-) mice that are deficient in TTP and two TNF receptors and compared the transcriptomic changes to "Double KO" (TNFR1-/-/TNFR2-/-) and WT mice. Spleen mRNA from four WT, four "Double KO", and four "Triple mice" was subjected to RNA-Seq in two phases. All the animals used in this study were males between the ages of 12-14 weeks and were on a mixed (75% C57BL/6NTac, 25% 129/SVEV) background. Examination of splenic gene expression difference between "Triple KO"-WT and "double KO"-WT data sets
Project description:Tristetraprolin (TTP) binds to specific AU-rich elements in the 3'UTR of certain transcripts and regulates post-transcriptional gene expression by increasing the rate of mRNA turnover. In this study, we evaluated the effects of TTP deficiency on the overall gene expression of spleen tissue, in order to discover tissue specific targets of TTP under normal physiologic conditions. We utilized "Triple KO" (Zfp36-/-/TNFR1-/-/TNFR2-/-) mice that are deficient in TTP and two TNF receptors and compared the transcriptomic changes to "Double KO" (TNFR1-/-/TNFR2-/-) and WT mice. Spleen mRNA from four WT, four "Double KO", and four "Triple mice" was subjected to RNA-Seq in two phases. All the animals used in this study were males between the ages of 12-14 weeks and were on a mixed (75% C57BL/6NTac, 25% 129/SVEV) background.
Project description:Members of the tristetraprolin (TTP) family of RNA-binding proteins can bind to and promote the decay of specific transcripts containing AU-rich motifs. ZFP36 (TTP) is best known for regulating cytokine expression in myeloid cells; however, the mammalian paralogues ZFP36L1 and ZFP36L2 have not been viewed as important in controlling inflammation. To study potential functional overlaps of these three TTP family proteins in myeloid cells, we developed myeloid-specific knock-out (M-KO) mice of these genes, singly and together. M-Zfp36-KO mice exhibited a mild inflammatory syndrome late in life, while M-Zfp36l1-KO and M-Zfp36l2-KO mice had no apparent spontaneous phenotypes. Mice with simultaneous deficiency of all three TTP family members in myeloid cells developed a severe, spontaneous, inflammatory phenotype, with a median survival of 8 weeks. Macrophages derived from these mice contained many more stabilized transcripts than cells from M-Zfp36-KO mice, many encoding pro-inflammatory cytokines and chemokines. Our findings emphasize the importance of all three family members, acting in concert, in myeloid cell function.
Project description:Members of the tristetraprolin (TTP) family of RNA-binding proteins can bind to and promote the decay of specific transcripts containing AU-rich motifs. ZFP36 (TTP) is best known for regulating cytokine expression in myeloid cells; however, the mammalian paralogues ZFP36L1 and ZFP36L2 have not been viewed as important in controlling inflammation. To study potential functional overlaps of these three TTP family proteins in myeloid cells, we developed myeloid-specific knock-out (M-KO) mice of these genes, singly and together. M-Zfp36-KO mice exhibited a mild inflammatory syndrome late in life, while M-Zfp36l1-KO and M-Zfp36l2-KO mice had no apparent spontaneous phenotypes. Mice with simultaneous deficiency of all three TTP family members in myeloid cells developed a severe, spontaneous, inflammatory phenotype, with a median survival of 8 weeks. Macrophages derived from these mice contained many more stabilized transcripts than cells from M-Zfp36-KO mice, many encoding pro-inflammatory cytokines and chemokines. Our findings emphasize the importance of all three family members, acting in concert, in myeloid cell function.
Project description:Controlled decay of cytokine and chemokine mRNAs restrains the time and amplitude of inflammatory responses. Tristetraprolin (TTP) binds to AU-rich elements in 3´ untranslated regions of mRNA and targets the bound mRNA for degradation. We have addressed here the function of TTP in balancing the macrophage activation state by a comprehensive analysis of TTP-dependent mRNA decay in LPS-stimulated macrophages from WT and TTP-deficient mice.
Project description:Posttranscriptional regulation of mRNA levels in neutrophils and its consequences for immune responses are unexplored. By employing profiling of the neutrophil transcriptome we show that the mRNA-destabilizing protein tristetraprolin (TTP) limits the expression of hundreds of genes, including genes negatively regulating apoptosis. Elicited TTP-deficient neutrophils exhibited reduced apoptosis and were increased in numbers. The anti-apoptotic protein Mcl-1 was elevated in TTP-deficient neutrophils and Mcl1 mRNA was bound and destabilized by TTP. Ablation of TTP in macrophages and neutrophils resulted in an improved defense and survival of mice during invasive infection with Streptococcus pyogenes. Mice lacking myeloid TTP prevented dissemination of bacteria and efficiently blunted systemic disease by massive but controlled neutrophil deployment. These data identify posttranscriptional control by TTP to restrict neutrophils and antimicrobial defense.
Project description:Controlled decay of cytokine and chemokine mRNAs restrains the time and amplitude of inflammatory responses. Tristetraprolin (TTP) binds to AU-rich elements in 3´ untranslated regions of mRNA and targets the bound mRNA for degradation. We have addressed here the function of TTP in balancing the macrophage activation state by a comprehensive analysis of TTP-dependent mRNA decay in LPS-stimulated macrophages from WT and TTP-deficient mice. We compared mRNA stability in LPS-treated BMDMs from WT and TTP-/- mice by microarray-based measurement of the remnant mRNA after transcriptional blockade with actinomycin D (act D). To increase the sensitivity of the mRNA decay profiling we inhibited the LPS-activated p38 MAPK with the specific inhibitor SB203580 since p38 MAPK negatively regulates the mRNA-destabilizing activity of TTP. LPS stimulation was for 3h before addition of act D. RNA was harvested at 0', 45' and 90' thereafter.
Project description:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility.