Macrophage GIT1 contributes to bone regeneration by regulating inflammatory response
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE144739 | GEO | 2020/02/05
REPOSITORIES: GEO
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Project description:Macrophage GIT1 contributes to bone regeneration by regulating inflammatory response
| PRJNA604763 | ENA
Project description:Despite the best treatment, approximately 10% of fractures still face undesirable repair. Recently, many studies have focused on the importance of macrophages in bone repair; however, the cellular mechanisms by which they work are not yet fully understood. In this study, we explored the functions of macrophage G-protein-coupled receptor interacting protein 1 (GIT1) in healing a tibial monocortical defect model. Using GIT1flox/flox Lyz2-Cre (GIT1 CKO) mice, we observed that a GIT1 deficiency in the macrophages led to an exacerbation of interleukin 1β (IL1β) production, more M1-like macrophage infiltration, and impaired intramembranous ossification in vivo. The results of in vitro assays further indicated that the macrophage GIT1 plays a critical role in several cellular processes in response to lipopolysaccharide (LPS), such as anti-oxidation, IL1β production alleviation, and glycolysis control. Although GIT1 has been recognized as a scaffold protein, our data clarified that GIT1-mediated extracellular-signal-regulated kinase (ERK) phosphorylation could activate nuclear factor (erythroid-derived 2)-like 2 (NRF2) in macrophages after LPS treatment. Moreover, we demonstrated that macrophage GIT1-activated ERK/NRF2 negatively regulates the 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 3 (PFKFB3), facilitating the decrease of glycolysis. Our findings uncovered a previously unrecognized role of GIT1 in regulating ERK/NRF2 in macrophages to control the inflammatory response, suggesting that macrophage GIT1 could be a potential target to improve bone regeneration. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research..
| S-EPMC7689802 | biostudies-literature
Project description:Nrf2 (NF-E2-related factor-2) transcription factor regulates oxidative/xenobiotic stress response and also represses inflammation. However, the mechanisms how Nrf2 alleviates inflammation are still unclear. Here, we demonstrate that Nrf2 interferes with lipopolysaccharide-induced transcriptional upregulation of proinflammatory cytokines, including IL-6 and IL-1β. ChIP-seq and ChIP-qPCR analyses revealed that Nrf2 binds to the proximity of these genes in macrophages and inhibits RNA Pol II recruitment. Further, we found that Nrf2-mediated inhibition is independent of the Nrf2 binding motif and reactive oxygen species level. Murine inflammatory models further demonstrated that Nrf2 interferes with IL6 induction and inflammatory phenotypes in vivo. Thus, contrary to the widely accepted view that Nrf2 suppresses inflammation through redox control, we demonstrate here that Nrf2 opposes transcriptional upregulation of proinflammatory cytokine genes. This study identifies Nrf2 as the upstream regulator of cytokine production and establishes a molecular basis for an Nrf2-mediated anti-inflammation approach. Gene expression in BMDMs obtained from wild-type and Keap1-CKO mice. In Keap1-CKO (Keap1 flox/flox::LysM-Cre) BMDMs, Nrf2 transcription factor is activated due to Keap1-deficiency. BMDMs were obtained by a culture of bone marrow cells in the presence of M-CSF for7 days. M1-activated BMDMs were obtained by stimulation with LPS and IFNg for 6 hours, while M2-activated BMDMs were obtained by a stimulation with IL-4 for 6 hours. Two independent BMDM cultures were performed, and each experiment contains samples obtained from one wild-type and one Keap1-CKO mice, respectively.
2016-05-12 | E-GEOD-71263 | biostudies-arrayexpress
Project description:Macrophages play critical roles in inflammation and tissue homeostasis, and their functions are regulated by various autocrine, paracrine, and endocrine factors. We have previously shown that CTRP6, a secreted protein of the C1q family, targets both adipocytes and macrophages to promote obesity-linked inflammation in adipose tissue. However, the gene programs and signaling pathways directly regulated by CTRP6 in macrophage remain unknown. Here, we combine transcriptomic and phosphoproteomic analyses to show that CTRP6 activates inflammatory gene programs and signaling pathways in bone marrow-derived macrophages (BMDMs). Treatment of BMDMs with CTRP6 upregulates proinflammatory, and suppresses the anti-inflammatory, gene expression. We show that CTRP6 activates p44/42-MAPK, p38-MAPK, and NF-κB signalings to promote inflammatory cytokine secretion from BMDMs, and that pharmacologic inhibition of these signaling pathways largely abolish the effects of CTRP6. Pretreatment of BMDMs with CTRP6 further augments LPS-induced inflammatory signaling and cytokine secretion from BMDMs. Consistent with the metabolic phenotype of proinflammatory M1-like macrophages, CTRP6 treatment induces a shift toward aerobic glycolysis and lactate production, reduces oxidative metabolism, and elevates mitochondrial ROS production in BMDMs. We use a Ctrp6 knockout mouse model to further confirm the physiologic relevance of our in vitro findings. BMDMs from CTRP6-deficient mice are less inflammatory at baseline and show a marked suppression of LPS-induced inflammatory gene expression and cytokine secretion. Loss of CTRP6 in mice also dampens LPS-induced inflammation and hypothermia. Collectively, we provide mechanistic evidence that CTRP6 regulates macrophage function, and neutralizing CTRP6 activity may have beneficial effects in reducing inflammation.
2024-01-26 | PXD042268 | Pride
Project description:Macrophages stimulated with lipopolysaccharide (LPS) plus interferon-g (IFNg) accumulate TGs in LDs, and long-chain acylcarnitines. Inhibition of TG synthesis results in diminished LD development, and increased long chain acylcarnitine levels, suggesting that FA fate is balanced between TG and acylcarnitine synthesis. Nevertheless, TG-synthesis is required for inflammatory macrophage function, since its inhibition negatively affects production of proinflammatory IL-1b, IL-6 and PGE2, and phagocytic capacity, and protects against LPS-induced sock in vivo.
2020-07-04 | GSE145523 | GEO
Project description:Long noncoding RNAs (lncRNAs) have emerged as novel regulators of macrophage biology and related inflammatory cardiovascular diseases. However, studies focused on lncRNAs in human macrophage subtypes, particularly human lncRNAs that are not conserved in rodents, are limited. Through RNA-seq of human monocyte-derived macrophages, we identified Suppressor of Inflammatory Macrophage Apoptosis lncRNA (SIMALR), a human macrophage-specific long intergenic noncoding RNA, to be highly induced in LPS/IFNγ-stimulated macrophages. Treatment of LPS/IFNγ stimulated THP1 human macrophages with SIMALR antisense oligonucleotides induced apoptosis of inflammatory macrophages, as shown by increased protein expression of cleaved PARP, caspase 9, caspase 3, and Annexin V+. RNA-seq of control versus SIMALR knockdown in LPS/IFNγ-stimulated human monocyte derived macrophages showed NTN1 to be significantly decreased upon SIMALR knockdown. As expected, NTN1 knockdown in LPS/IFNγ-stimulated macrophages induced apoptosis. This apoptotic phenotype was attenuated by adding recombinant NTN1 after SIMALR knockdown. Furthermore, NTN1 promoter-luciferase reporter activity was increased in HEK293T cells treated with lentiviral overexpression of SIMALR. NTN1 promoter activity is known to require HIF1α. RNA immunoprecipitation and microscopy studies suggest that SIMALR may interact with HIF1α to regulate NTN1 transcription, thereby regulating apoptosis of macrophages. In translational studies, SIMALR was found to be expressed in macrophages in human carotid atherosclerotic plaques of symptomatic patients. SIMALR is a non-conserved, human macrophage lincRNA expressed in human atherosclerosis that regulates macrophage apoptosis. SIMALR partners with HIF1α to regulate NTN1, which is a known macrophage survival factor. This work illustrates the importance of interrogating the functions of non-conserved human lincRNAs and exploring their translational and therapeutic potential in human atherosclerosis.
2022-11-23 | GSE212381 | GEO
Project description:BackgroundIt has recently become evident that activating/inhibitory cell surface immune receptors play a critical role in regulating immune and inflammatory processes in the central nervous system (CNS). The immunoreceptor CD300f expressed on monocytes, neutrophils, and mast cells modulates inflammation, phagocytosis, and outcome in models of autoimmune demyelination, allergy, and systemic lupus erythematosus. On the other hand, a finely regulated inflammatory response is essential to induce regeneration after injury to peripheral nerves since hematogenous macrophages, together with resident macrophages and de-differentiated Schwann cells, phagocyte distal axonal and myelin debris in a well-orchestrated inflammatory response. The possible roles and expression of CD300f and its ligands have not been reported under these conditions.MethodsBy using quantitative PCR (QPCR) and CD300f-IgG2a fusion protein, we show the expression of CD300f and its ligands in the normal and crush injured sciatic nerve. The putative role of CD300f in peripheral nerve regeneration was analyzed by blocking receptor-ligand interaction with the same CD300f-IgG2a soluble receptor fusion protein in sciatic nerves of Thy1-YFP-H mice injected at the time of injury. Macrophage M1/M2 polarization phenotype was also analyzed by CD206 and iNOS expression.ResultsWe found an upregulation of CD300f mRNA and protein expression after injury. Moreover, the ligands are present in restricted membrane patches of Schwann cells, which remain stable after the lesion. The lesioned sciatic nerves of Thy1-YFP-H mice injected with a single dose of CD300f-IgG2a show long lasting effects on nerve regeneration characterized by a lower number of YFP-positive fibres growing into the tibial nerve after 10 days post lesion (dpl) and a delayed functional recovery when compared to PBS- or IgG2a-administered control groups. Animals treated with CD300f-IgG2a show at 10 dpl higher numbers of macrophages and CD206-positive cells and lower levels of iNOS expression than both control groups. At later time points (28 dpl), increased numbers of macrophages and iNOS expression occur.ConclusionsTaken together, these results show that the pair CD300f ligand is implicated in Wallerian degeneration and nerve regeneration by modulating both the influx and phenotype of macrophages.
| S-EPMC4531482 | biostudies-literature
Project description:Macrophage plasticity allows cells to adopt different phenotypes, a property with potentially important implications in chronic pulmonary disorders such as cystic fibrosis (CF). We examined the transcriptional and functional significance of macrophage repolarization from an “M1” (LPS-stimulated) towards an “M2” phenotype using 5 stimuli. We found that macrophages exhibit highly diverse responses to distinct M2-polarizing stimuli. Specifically, we observed that IL-10 abrogated LPS-tolerance allowing for rapid restoration of LPS responsiveness. In contrast, IL-4 enhanced LPS-tolerance, dampening pro-inflammatory responses after repeat LPS challenge. We found enrichment of phagocytosis-associated pathways in macrophages stimulated with IL-10, leading them to display the greatest efferocytosis ability. Finally, we observed that CF macrophages had intact reparative responses, suggesting that macrophage contributions to CF lung disease are shaped by their environmental milieu and are modifiable. These findings highlight the diversity of macrophage activation states, attribute functional consequences to these stimuli, and provide a unique resource of human macrophage repolarization markers.
2018-09-30 | GSE100521 | GEO
Project description:Macrophage activation undergoes signal-transduced changes in protein modifications, enabling the coordinated control of transcription and cellular metabolism. However, the role of protein acetylation in signal transduction during macrophage activation remains obscure. Here, we demonstrate that peroxiredoxin 1 (PRDX1), a key regulator of redox signaling, is a novel substrate of the MOF lysine acetyltransferase. Employing a gel based in vitro HAT assay followed by LC-MS, we mapped PRDX1 lysine acetylation sites. PRDX1 K197ac was identified as the most prominent MOF acetylation site. We show that MOF-dependent acetylation of lysine 197 of PRDX1 (PRDX1 K197ac) enhances its peroxidase activity. We find that PRDX1 K197ac is an inflammatory signal-regulated modification, which decreases in mouse macrophages stimulated with bacterial lipopolysaccharides (LPS) but not with IL-4 or IL-10. LPS-induced decrease of PRDX1 K197ac elevates cellular ROS accumulation and augments phosphorylation of ERK1/2 but not p38 or AKT phosphorylation. Concomitantly, diminished PRDX1 K197ac stimulates glycolysis, potentiates H3 serine 28 phosphorylation, and ultimately enhances the production of pro-inflammatory mediators such as IL-6. Collectively, our findings uncover a regulatory role for redox protein acetylation during inflammatory macrophage activation through modulating signal transduction and coordinating metabolic and transcriptional programs.
2024-10-25 | PXD046284 | Pride
Project description:Background & aims: Both macrophages and T cells play a critical role in inflammatory bowel disease (IBD) development. Since our previous studies have shown that a novel immune checkpoint molecule ERMAP affects macrophage polarization and negatively regulate T cell responses, we investigated the effects of ERMAP on IBD progression in mice. Methods: Using an dextran sodium sulfate (DSS)-induced IBD mice model, knockdown of ERMAP in RAW264.7 macrophages, ERMAP gene knockout mice, and Global gene expression analysis by RNA-seq, We investigate the effect of ERMAP on IBD by regulation of T cells and macrophages, NOD-like receptor (NLR) protein family pathway in macrophages. Results: We show here that administration of ERMAP protein significantly increases the proportion of anti-inflammatory M2-type macrophages and inhibits T cell activation and proliferation in IBD mice induced by DSS. Knockdown of ERMAP in RAW264.7 macrophages reduces M2-type macrophage polarization and increases T cell responses. Adoptive transfer of macrophages from ERMAP knockout mice exacerbates DSS-induced IBD. Global gene expression analysis by RNA-seq shows that ERMAP inhibits the NLR protein family pathway in macrophages. Conclusions: Our results suggest that ERMAP protein has the potential to be used in the treatment of IBD by regulating macrophage and T cell functions.
2022-08-28 | GSE212010 | GEO