Next Generation Sequencing Facilitates Quantitative Analysis of Wild Type and Smad7-/- E15.5 tooth germ Transcriptomes
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ABSTRACT: Smad7 is known to regulate both Smad-dependent and Smad-independent TGF-β signaling pathways but is also extensively involved in crosstalks with other signaling pathways. To investigate the underlying molecular mechanism, we conducted RNA-Seq analysis on E15.5 molars from Smad7 mutant and control mice.
Project description:Repair of the infarcted heart requires TGFβ-Smad3 signaling in cardiac myofibroblasts. However, TGF-β-driven myofibroblast activation needs to be tightly regulated in order to prevent excessive fibrosis and adverse remodeling that may precipitate heart failure. We hypothesized that induction of the inhibitory Smad, Smad7 may restrain infarct myofibroblast activation, and we examined the molecular mechanisms of Smad7 actions. In a mouse model of non-reperfused infarction, Smad3 activation triggered Smad7 synthesis in β-SMA+ infarct myofibroblasts, but not in β-SMA-/PDGFRα+ fibroblasts. Myofibroblast-specific Smad7 loss increased heart failure-related mortality, worsened dysfunction, and accentuated fibrosis in the infarct border zone and in the papillary muscles. Smad7 attenuated myofibroblast activation and reduced synthesis of structural and matricellular extracellular matrix proteins. Smad7 actions on TGF-β cascades involved de-activation of Smad2/3 and non-Smad pathways, without any effects on TGF-β receptor activity. Unbiased transcriptomic and proteomic analysis identified receptor tyrosine kinase signaling as a major target of Smad7. Smad7 interacted with Erbb2 in a TGF-independent manner and restrained Erbb1/Erbb2 activation, suppressing fibroblast expression of fibrogenic proteases, integrins and CD44. Smad7 induction in myofibroblasts serves as an endogenous TGF-β-induced negative feedback mechanism that inhibits post-infarction fibrosis by restraining Smad-dependent and Smad-independent TGF-β responses, and by suppressing TGF-independent fibrogenic actions of Erbb2.
Project description:Increased level of angiotensin II (Ang II) plays a central role in the development of hypertensive vascular remodeling. Here, we identify the deubiquitinating enzyme JOSD2 as a protective factor and investigate its molecular mechanism in Ang II-induced vascular remodeling. Firstly, we found that JOSD2 was up-regulated in aortic smooth muscle cells but not endothelial cells of Ang II-challenged mouse vascular tissues. Whole-body knockout of JOSD2 significantly deteriorated Ang II-induced vascular remodeling in mice. Conversely, Ang II-induced vascular remodeling was reversed by VSMC-specific JOSD2 overexpression. In vitro, JOSD2 deficiency aggravated the fibrosis, proliferation, and migration induced by Ang II in vascular smooth muscle cells (VSMCs), while these changes were reversed by JOSD2 overexpression. RNA-seq analysis showed that the protective effects of JOSD2 in VSMCs were related to TGFβ-SMAD pathway. Furthermore, the LC-MS/MS analysis identified SMAD7, a negative regulator in TGFβ-SMAD pathway, as the substrate of JOSD2. JOSD2 specifically bound to the MH1 domain of SMAD7 to removed K48-linked Ub chains of SMAD7 at lysine 220 to sustain SMAD7 stability. Taken together, our finding reveals that JOSD2-SMAD7 axis is critical for relieving Ang II-induced vascular remodeling and JOSD2 maybe a novel and potential therapeutic target for hypertensive vascular remodeling.
Project description:Increased level of angiotensin II (Ang II) plays a central role in the development of hypertensive vascular remodeling. Here, we identify the deubiquitinating enzyme JOSD2 as a protective factor and investigate its molecular mechanism in Ang II-induced vascular remodeling. Firstly, we found that JOSD2 was up-regulated in aortic smooth muscle cells but not endothelial cells of Ang II-challenged mouse vascular tissues. Whole-body knockout of JOSD2 significantly deteriorated Ang II-induced vascular remodeling in mice. Conversely, Ang II-induced vascular remodeling was reversed by VSMC-specific JOSD2 overexpression. In vitro, JOSD2 deficiency aggravated the fibrosis, proliferation, and migration induced by Ang II in vascular smooth muscle cells (VSMCs), while these changes were reversed by JOSD2 overexpression. RNA-seq analysis showed that the protective effects of JOSD2 in VSMCs were related to TGFβ-SMAD pathway. Furthermore, the LC-MS/MS analysis identified SMAD7, a negative regulator in TGFβ-SMAD pathway, as the substrate of JOSD2. JOSD2 specifically bound to the MH1 domain of SMAD7 to removed K48-linked Ub chains of SMAD7 at lysine 220 to sustain SMAD7 stability. Taken together, our finding reveals that JOSD2-SMAD7 axis is critical for relieving Ang II-induced vascular remodeling and JOSD2 maybe a novel and potential therapeutic target for hypertensive vascular remodeling.
Project description:The transforming growth factor beta (TGF-β) superfamily proteins are potent regulators of cellular development and differentiation. Long non-coding RNAs (lncRNAs) play widespread roles in spatial-temporal regulation of early development. However, the roles of lncRNAs regulated by nodal/TGF-β signaling is still elusive. Here, we showed a nodal-driven Smad induced lncRNA in mouse embryonic stem cells (mESCs), lncRNA-Smad7, which is divergently transcribed to Smad7, regulates cell fate determination through repressing Bmp2. Depletion of lncRNA-Smad7 dramatically impairs cardiomyocyte differentiation in mESCs. Moreover, LncRNA-Smad7 represses Bmp2 expression and binds at the promoter region of Bmp2. Importantly, knock-down Bmp2 rescues the defect of cardiomyocyte differentiation. Hence, we showed that lncRNA-Smad7 is antagonistic to BMP signaling in mESCs. Furthermore, lncRNA-Smad7 regulates cell fate determination between osteocytes and myocytes formation in C2C12 cells by repressing Bmp2. Thus, we provide new insights regarding the antagonistic effects between nodal/TGF-β and BMP signaling via lncRNA-Smad7.
Project description:Induction of the inhibitory Smad, Smad7 serves as a negative feedback mechanism that restrains TGF-b-mediated actions in injured tissues. In inflammatory cells, Smad7 has been suggested to exert both pro-inflammatory actions attributed to inhibition of TGF-b-induced suppression of inflammation, and anti-inflammatory effects due to disruption of the TAK-1/NF-kB system. Myocardial infarction triggers a macrophage-driven inflammatory response that plays a central role in cardiac repair, but also contributes to adverse remodeling and fibrosis. We hypothesized that Smad7 upregulation in infarct macrophages may play a modulatory role in cardiac repair, by restraining effects of TGF-b. To test the hypothesis, we investigated the response of Myeloid cell-specific Smad7 knockout mice (MyS7KO) following myocardial infarction protocols, and we examined the in vitro effects of Smad7 in isolated macrophages. Smad7 was upregulated in a subset of infarct macrophages, peaking 7 days after infarction. Myeloid cell-specific Smad7 loss did not affect baseline macrophage gene expression and had no significant effects on homeostatic functions. Although RNA-seq analysis predicted that, in the absence of Smad7, infarct macrophages may have attenuated activation of inflammatory pathways and suppressed TREM1 signaling, myeloid cell-specific Smad7 loss had no significant effects on ventricular dysfunction, adverse remodeling, scar remodeling and collagen deposition after myocardial infarction. In isolated macrophages, TGF-b attenuated pro-inflammatory cytokine and chemokine expression, modulated synthesis of matrix remodeling genes, and had profound effects on macrophage profile, inducing genes associated with activation of sphingosine-1 phosphate and integrin signaling pathways, and inhibiting cholesterol biosynthesis genes. However, RNA-seq and PCR array experiments showed that Smad7 loss has minimal effects on TGF-b-mediated macrophage responses, restraining synthesis of only a small fraction of TGF-b-induced genes, such as Itga5, Olfml3 and Fabp7. Smad7 absence did not affect the anti-inflammatory actions of TGF-b in TNF-stimulated cells. In conclusion, our findings suggest a limited role for macrophage Smad7 in regulation of post-infarction inflammation and repair, and demonstrate that the anti-inflammatory effects of TGF-b in macrophages are not restrained by endogenous Smad7 induction.
Project description:Induction of the inhibitory Smad, Smad7 serves as a negative feedback mechanism that restrains TGF-b-mediated actions in injured tissues. In inflammatory cells, Smad7 has been suggested to exert both pro-inflammatory actions attributed to inhibition of TGF-b-induced suppression of inflammation, and anti-inflammatory effects due to disruption of the TAK-1/NF-kB system. Myocardial infarction triggers a macrophage-driven inflammatory response that plays a central role in cardiac repair, but also contributes to adverse remodeling and fibrosis. We hypothesized that Smad7 upregulation in infarct macrophages may play a modulatory role in cardiac repair, by restraining effects of TGF-b. To test the hypothesis, we investigated the response of Myeloid cell-specific Smad7 knockout mice (MyS7KO) following myocardial infarction protocols, and we examined the in vitro effects of Smad7 in isolated macrophages. Smad7 was upregulated in a subset of infarct macrophages, peaking 7 days after infarction. Myeloid cell-specific Smad7 loss did not affect baseline macrophage gene expression and had no significant effects on homeostatic functions. Although RNA-seq analysis predicted that, in the absence of Smad7, infarct macrophages may have attenuated activation of inflammatory pathways and suppressed TREM1 signaling, myeloid cell-specific Smad7 loss had no significant effects on ventricular dysfunction, adverse remodeling, scar remodeling and collagen deposition after myocardial infarction. In isolated macrophages, TGF-b attenuated pro-inflammatory cytokine and chemokine expression, modulated synthesis of matrix remodeling genes, and had profound effects on macrophage profile, inducing genes associated with activation of sphingosine-1 phosphate and integrin signaling pathways, and inhibiting cholesterol biosynthesis genes. However, RNA-seq and PCR array experiments showed that Smad7 loss has minimal effects on TGF-b-mediated macrophage responses, restraining synthesis of only a small fraction of TGF-b-induced genes, such as Itga5, Olfml3 and Fabp7. Smad7 absence did not affect the anti-inflammatory actions of TGF-b in TNF-stimulated cells. In conclusion, our findings suggest a limited role for macrophage Smad7 in regulation of post-infarction inflammation and repair, and demonstrate that the anti-inflammatory effects of TGF-b in macrophages are not restrained by endogenous Smad7 induction.
Project description:Gene expression profiles were generated from embryonic day 13.5 CD-1 mouse mandibular first molars whole tooth and non-tooth non-bone oral tissue.
Project description:Background & Aims: Although hepcidin expression was shown to be induced by the BMP signaling pathway, it is not yet known how iron regulates hepcidin and which of the BMP molecules is the endogenous regulator of iron homeostasis in vivo. We therefore assessed liver transcription profiles of mice fed an iron-deficient or an iron-enriched diet and looked for genes that were regulated similarly to hepcidin in that context. Methods: Genome-wide liver expression profiles of mice of the B6 and D2 genetic backgrounds subjected to iron-deficient, -balanced, or -enriched diets were obtained using Agilent Whole Genome microarrays. Real-time quantitative-PCR and western-blots were used to confirm microarray results and compare gene expression variations induced by secondary iron deficiency or iron overload with those consecutive to Smad4 or Hamp1-deficiency. Results: Among 1419 transcripts significantly modulated by the dietary iron content, four were regulated similarly to the hepcidin genes Hamp1 and Hamp2. They are coding for Bmp6, the regulator of Bmp/Smad signal transduction Smad7, the negative regulator of basic helix-loop-helix (bHLH) proteins Id1, and a protein with a bHLH domain, Atoh8. The iron overload developed by Smad4 and Hamp1-deficient mice also increased Bmp6 transcription. Body iron stores influence Smad1/5/8 phosphorylation and, as shown by analysis of mice with liver-specific disruption of Smad4, the binding partner for the receptor-activated Smads is necessary for activation of Smad7, Id1, and Atoh8 transcription by iron. Conclusions: Liver expression of Bmp6, Smad7, Id1, and Atoh8 is regulated by body iron stores and may participate in hepcidin regulation through the Bmp/Smad pathway. Keywords: response to dietary iron content
Project description:Gene expression profiles were generated from embryonic day 13.5 CD-1 mouse mandibular first molars whole tooth and non-tooth non-bone oral tissue. Three biological replicates from embryonic day 13.5 CD-1 mice were generated from pooled tissues across multiple mice. The tooth germ and non-tooth oral tissues were paired from the same embryos.