Project description:Dysregulation of Th17 differentiation was implicated in multiple inflammatory and autoimmune diseases including autoimmune uveitis. In the current study, we have provided evidence indicating that lactate-derived lactylation plays important roles in regulating Th17 differentiation. The lactylation level of CD4+ T cells was upregulated in EAU mice and inhibiting lactylation resulted in impaired EAU progression. We characterized the global lactylome of CD4+ T cells of normal and EAU mice. We found that the differentially lactylated proteins were enriched in pathways related to immune responses including leukocyte differentiation. Importantly, our results show that the lactylation level of Ikzf1 (K164) functions in regulating Th17 differentiation by differentially modulating gene expression patterns which are related to CD4+ T cell differentiation by CUT& Tag analysis. In view of the above mentioned well-documented evidence, Ikzf1 lactylation might represent an important regulator for Th17 differentiation in autoimmune uveitis.
Project description:Distinct metabolic programs support the differentiation of CD4+T cells into their separate lineages. In this study, we investigated metabolic mechanisms underlying the differentiation of IL-9 producing-CD4+T cells (TH9) in allergic airway inflammation and cancerous tumors. We found here that SIRT1 negatively regulates TH9 differentiation. A deficiency of SIRT1 induced by either conditional deletion in mouse CD4+T cells or the use of small interfering RNA (siRNA) in mouse or human T cells increased IL-9 production, whereas ectopic SIRT1 expression inhibited it. Notably, SIRT1-inhibited the differentiation of TH9 cells that regulated anti-tumor immunity and allergic pulmonary inflammation. Glycolytic activation through the mTOR-hypoxia-inducible factor-1α (HIF1α) pathway was required for the differentiation of the TH9 cells that confer protection against tumors and are involved in allergic airway inflammation. Our results define the essential features of a SIRT1-mTOR-HIF1α signaling-coupled glycolytic pathway in inducing TH9 cell differentiation, with implications for metabolic reprogramming as an immunotherapeutic approach. Lymphocytes were isolated from the spleen and lymph nodes of mice and sorted on a FACSAria II (Becton Dickinson). The sorted naïve T cells (CD4+TCR+CD62Lhi CD44lo) from WT or SIRT1flox/flox-CD4-Cre mice were used for in vitro culture. T cells were activated with 2 ug/ml anti-CD3 (2C11; Bio X Cell), 2 ug/ml anti-CD28 (37.51; Bio X Cell) and 100 U/ml human IL-2. For TH9 cell differentiation, cultures were supplemented with 10 ng/ml IL-4 (R&D system), 2 ng/ml TGFβ1 (R&D system). After 5-6 d culture, differentiated T cells were collected and for microarray assay.
Project description:Embryonic stem cells (ESCs) favor glycolysis over oxidative phosphorylation for energy production, and glycolytic metabolism is critical for pluripotency establishment, maintenance and exit. However, how glycolysis regulates the self-renewal and differentiation of ESCs remains elusive. Here, we demonstrated that protein lactylation, regulated by intracellular lactate, contributes to the self-renewal of ESCs. Next, the lactylome profiles of ESCs with and without a lactate dehydrogenase (Ldh) inhibitor, which suppresses the conversion of pyruvate to lactate, were depicted. It was notable that many lactylated proteins are involved in the self-renewal and differentiation of ESCs. We further showed that Esrrb, an orphan nuclear receptor involved in pluripotency maintenance and extraembryonic endoderm stem cell (XEN) differentiation, is lactylated on K228 and K232. Lactylation of Esrrb enhances its activity in promoting ESC self-renewal in the absence of LIF and XEN differentiation of ESCs, through increasing its binding at target genes. Our studies reveal the importance of protein lactation in the self-renewal and XEN differentiation of ESCs, and the underlying mechanism for glycolytic metabolism regulating cell fate choice.
Project description:Protein lactylation is a process that is fueled by lactate, generated by the enzyme lactate dehydrogenase (Ldh) from pyruvate. Despite prior research, the precise role of protein lactylation in controlling the identity of mouse embryonic stem cells (ESCs) is still not fully understood. We observed that inhibiting or eliminating Ldha causes a reduction in global protein lactylation in ESCs, and RNA-seq analysis suggests that Ldha inhibition induces a 2-cell-like cell (2CLC) signature in ESCs. To probe the underlying mechanisms, we performed quantitative lactylation proteomics analysis, we discovered that Hdac1, a gene with significant regulatory roles during the 2-cell stage (2C), undergoes lactylation modification. Additionally, we observed that treatment with an Ldh (lactate dehydrogenase) inhibitor can decrease the lactylation levels of Hdac1. Mechanistically, we discovered that Ldha positively regulates the lactylation of Hdac1, promoting its direct binding to zygotic genome activation (ZGA) gene promoters and has stronger deacetylase activity. This leads to the removal of acetyl groups from H3K27 on these loci, effectively suppressing the expression of 2C genes. Our study presents novel evidence supporting protein lactylation's potential as a means of inhibiting the generation of 2CLCs and modulating acetylation activity.
Project description:Protein lactylation is a process that is fueled by lactate, generated by the enzyme lactate dehydrogenase (Ldh) from pyruvate. Despite prior research, the precise role of protein lactylation in controlling the identity of mouse embryonic stem cells (ESCs) is still not fully understood. We observed that inhibiting or eliminating Ldha causes a reduction in global protein lactylation in ESCs, and RNA-seq analysis suggests that Ldha inhibition induces a 2-cell-like cell (2CLC) signature in ESCs. To probe the underlying mechanisms, we performed quantitative lactylation proteomics analysis, we discovered that Hdac1, a gene with significant regulatory roles during the 2-cell stage (2C), undergoes lactylation modification. Additionally, we observed that treatment with an Ldh (lactate dehydrogenase) inhibitor can decrease the lactylation levels of Hdac1. Mechanistically, we discovered that Ldha positively regulates the lactylation of Hdac1, promoting its direct binding to zygotic genome activation (ZGA) gene promoters and has stronger deacetylase activity. This leads to the removal of acetyl groups from H3K27 on these loci, effectively suppressing the expression of 2C genes. Our study presents novel evidence supporting protein lactylation's potential as a means of inhibiting the generation of 2CLCs and modulating acetylation activity.
Project description:The zinc finger transcription factor Ikaros1 (Ikzf1) is required for lymphoid development in mammals. It is characterized by the presence of four zinc fingers in its DNA binding domain and two zinc fingers in the C-terminal protein interaction module. Here, we describe the phenotypes of zebrafish homozygous for two distinct mutant ikzf1 alleles. The IT325 variant lacks the C-terminal two zinc fingers, whereas the fr105 variant retains only the first zinc finger of the DNA binding domain. Our results indicate that an intact ikzf1 gene is required for larval T cell development, whereas low levels of adult lymphoid development recover in the mutants. By contrast, the mutants exhibit a signature of increased myelopoiesis at larval and adult stages. Of note, both mutants stimulate erythroid differentiation in larvae, indicating that the C-terminal zinc fingers negatively regulate the extent of red blood cell production. An unexpected differential effect of the two mutants on adult erythropoiesis suggests a direct requirement of an intact DNA binding domain for entry of progenitors into the red blood cell lineage. Collectively, our results reinforce the biological differences between larval and adult haematopoiesis, indicate a stage-specific function of ikzf1 in regulating the hierarchical bifurcations of differentiation, and assign distinct functions to the DNA binding domain and the C-terminal zinc fingers.
Project description:Distinct metabolic programs support the differentiation of CD4+T cells into their separate lineages. In this study, we investigated metabolic mechanisms underlying the differentiation of IL-9 producing-CD4+T cells (TH9) in allergic airway inflammation and cancerous tumors. We found here that SIRT1 negatively regulates TH9 differentiation. A deficiency of SIRT1 induced by either conditional deletion in mouse CD4+T cells or the use of small interfering RNA (siRNA) in mouse or human T cells increased IL-9 production, whereas ectopic SIRT1 expression inhibited it. Notably, SIRT1-inhibited the differentiation of TH9 cells that regulated anti-tumor immunity and allergic pulmonary inflammation. Glycolytic activation through the mTOR-hypoxia-inducible factor-1α (HIF1α) pathway was required for the differentiation of the TH9 cells that confer protection against tumors and are involved in allergic airway inflammation. Our results define the essential features of a SIRT1-mTOR-HIF1α signaling-coupled glycolytic pathway in inducing TH9 cell differentiation, with implications for metabolic reprogramming as an immunotherapeutic approach.
Project description:Alterations of IKZF1, encoding the lymphoid transcription factor IKAROS, are a hallmark of high risk acute lymphoblastic leukemia (ALL), however the role of IKZF1 alterations in ALL pathogenesis is poorly understood. Here we show that in mouse models of BCR-ABL1 leukemia, Ikzf1 and Arf alterations synergistically promote the development of an aggressive lymphoid leukemia. Ikzf1 alterations were associated with acquisition of stem cell-like features, including self-renewal and increased bone marrow stromal adhesion. Rexinoid receptor agonists reversed this phenotype, in part by inducing expression of IKZF1, resulting in abrogation of adhesion and self-renewal, cell cycle arrest and attenuation of proliferation without direct cytotoxicity. Retinoids potentiated the activity of dasatinib in mouse and human BCR-ABL1 ALL, providing a new therapeutic option in IKZF1-mutated ALL. Significance: The outcome of therapy for high-risk acute lymphoblastic leukemia remains suboptimal despite contemporary chemotherapy and the advent of targeted therapeutic approaches. Recent genomic studies have identified deletions or mutations of IKZF1 as a hallmark of high-risk ALL, but an understanding of how IKZF1 alteration contribute to leukemia development are lacking. Here we show that IKZF1 alterations drive lymphoid lineage, a stem cell-like phenotype, abnormal bone marrow adhesion, and poor responsiveness to tyrosine kinase inhibitor (TKI) therapy. Using a high-content screen, we show that retinoids reverse this phenotype in part by inducing expression of wild type IKZF1, and increase responsiveness to TKIs. These findings provide new insight into the pathogenesis of high-risk ALL and potential new therapeutic approaches. Pre-B mRNA profiles of p185 MIG and IK6 cells, DMSO or drug treated, in 3 or 4 replicates, using Illumina HiSeq 2500.
Project description:The Ikzf1 locus encodes the lymphoid specific transcription factors Ikaros, which play an essential role in both T and B cell differentiation, while deregulation or mutation of IKZF1/Ikzf1 is involved in leukemia. Tissue-specific and cell identity genes are usually associated with clusters of enhancers, also called super-enhancers, which are believed to ensure proper regulation of gene expression throughout cell development and differentiation. Several potential regulatory regions have been identified in close proximity of Ikzf1, however, the full extent of the regulatory landscape of the Ikzf1 locus is not yet established. In this study, we combined epigenomics and transcription factor binding along with high-throughput enhancer assay and 4C-seq to prioritize an enhancer element located 120 kb upstream of the Ikzf1 gene. We found that the deletion of the E120 enhancer resulted in a significant reduction of Ikzf1 mRNA. However, the epigenetic landscape and 3D topology of the locus were only slightly affected, highlighting the complexity of the regulatory landscape regulating the Ikzf1 locus
Project description:Analysis of the effect of Prednisolone in mouse splenocytes with and without Ikzf1 at gene expression level. The hypothesis tested in the present study was that loss of Ikzf1 affects the induction and repression of the Glucocorticoid receptor target genes. Results provide important information of the differentially expressed genes regulated by Ikzf1 upon Prednisolone treatment, explaining the resistance towards Glucocorticoid-induced apoptosis in splenocytes harboring Ikzf1 loss. Total RNA was obtained from WT and Ikzf1+/- splenocytes subjected to 16 hours Prednsiolone treatment compared to untreated cells.