Similar Datasets
Project description:High-resolution quantitative profiling of tRNA abundance and modification status in hematopoietic cells upon Trmt6 deletion by mim-tRNAseq
2024-06-03 | GSE252912 | GEO
Project description:Hematopoietic stem cells (HSCs) have some unique physiological adaptations to maintain blood cell production and deal with stress responses throughout life. To maintain such adaptations, HSCs are particularly dependent on maintaining a tightly controlled protein translation rate. However, how HSCs fine tune protein translation has not been fully described. In this study, we report the role of TRMT6 in regulating HSC function in adult hematopoiesis. Trmt6-null mice became moribund due to hematopoietic failure with pancytopenia in the blood and bone marrow 4 to 8 weeks after Trmt6 deletion. Trmt6-deleted bone marrow cells failed to repopulate hemoablated recipients in competitive transplantation experiments. Loss of TRMT6 resulted in an abnormally high rate of recruitment of quiescent hematopoietic stem cells (HSCs) into the cell cycle. Cycling HSCs produced progenitors at the expense of self-renewal, which led to the exhaustion of the HSC pool. Mechanistically, mTORC1 signaling pathway was highly upregulated in HSC-enriched cell populations after Trmt6 deletion by single cell RNA-seq analysis. Furthermore, TRMT6 was required for tRNA m1A modification required for HSC quiescence and self-renewal. Our data indicate that TRMT6 promotes the expression of TSC1, fine-tuning mTORC1 signaling level which is essential for HSC maintenance and self-renewal in adult hematopoiesis.
2024-06-03 | GSE230711 | GEO
Project description:tRNA m1A modification regulate hematopoietic stem cell maintenance via mTORC1 signaling
| PRJNA1063223 | ENA
Project description:tRNA m1A modification regulate hematopoietic stem cell maintenance via mTORC1 signaling [mim-tRNAseq]
| PRJNA1063221 | ENA
Project description:tRNA m1A modification regulate hematopoietic stem cell maintenance via mTORC1 signaling [scRNA-seq]
| PRJNA962329 | ENA
Project description:Haematopoietic stem cells (HSCs) possess unique physiological adaptations to sustain blood cell production and cope with stress responses throughout life. To maintain these adaptations, HSCs rely on maintaining a tightly controlled protein translation rate. However, the mechanism of how HSCs regulate protein translation remains to be fully elucidated. In this study, we investigate the role of transfer RNA (tRNA) m1A58 'writer' proteins TRMT6 and TRMT61A in regulating HSCs function. Trmt6 deletion promoted HSC proliferation through aberrant activation of mTORC1 signaling. TRMT6-deficient HSCs exhibited an impaired self-renewal ability in competitive transplantation assay. Mechanistically, single cell RNA-seq analysis reveals that the mTORC1 signaling pathway is highly upregulated in HSC-enriched cell populations after Trmt6 deletion. m1A-tRNA-seq and Western blot analysis suggest that TRMT6 promotes methylation modification of specific tRNA and expression of TSC1, fine-tuning mTORC1 signaling levels. Furthermore, Pharmacological inhibition of the mTORC1 pathway rescued functional defect in TRMT6-deficient HSCs. To our knowledge, this study is the first to elucidate a mechanism by which TRMT6-TRMT61A complex-mediated tRNA-m1A58 modification regulates HSC homeostasis.
| S-EPMC11231335 | biostudies-literature
Project description:Using genetic mouse models, high-throughput sequencing, transcriptome-wide m1A profiling and ribosome profiling, we find: (1) Translation is the most active process of these genetic information processing in early T cell activation. (2) T cells upregulate tRNA-m1A58 “writer” proteins TRMT61A and TRMT6 to install m1A58 modification to a specific subset of early expressed tRNAs during the early stage of activation. (3) m1A58 modifications in tRNA support rapid and adequate synthesis of MYC and other key functional proteins, guide the exit of naïve T cells from quiescence state into a proliferative state, and promote rapid T cell expansion after activation.
2022-07-23 | GSE184909 | GEO
Project description:The mTORC1 pathway coordinates nutrient and growth factor signals to maintain organismal homeostasis. Whether nutrient signaling to mTORC1 regulates stem cell function remains unknown. Here, we show that SZT2 - a protein required for mTORC1 downregulation upon nutrient deprivation - is critical for hematopoietic stem cell (HSC) homeostasis. Ablation of SZT2 in HSCs decreased the reserve and impaired the repopulating capacity of HSCs. Furthermore, ablation of both SZT2 and TSC1 - 2 repressors of mTORC1 on the nutrient and growth factor arms, respectively - led to rapid HSC depletion, pancytopenia, and premature death of the mice. Mechanistically, loss of either SZT2 or TSC1 in HSCs led to only mild elevation of mTORC1 activity and reactive oxygen species (ROS) production. Loss of both SZT2 and TSC1, on the other hand, simultaneously produced a dramatic synergistic effect, with an approximately 10-fold increase of mTORC1 activity and approximately 100-fold increase of ROS production, which rapidly depleted HSCs. These data demonstrate a critical role of nutrient mTORC1 signaling in HSC homeostasis and uncover a strong synergistic effect between nutrient- and growth factor-mediated mTORC1 regulation in stem cells.
| S-EPMC9566891 | biostudies-literature
Project description:NKAP is a multifunctional nuclear protein that associates with the histone deacetylase HDAC3. Although both NKAP and HDAC3 are critical for hematopoietic stem cell (HSC) maintenance and survival, it was not known whether these two proteins work together. To assess the importance of their association in vivo, serial truncation and alanine scanning was performed on NKAP to identify the minimal binding site for HDAC3. Mutation of either Y352 or F347 to alanine abrogated the association of NKAP with HDAC3, but did not alter NKAP localization or expression. Using a linked conditional deletion/re-expression system in vivo, we demonstrated that re-expression of the Y352A NKAP mutant failed to restore HSC maintenance and survival in mice when endogenous NKAP expression was eliminated using Mx1-cre and poly-IC, whereas re-expression of wild type NKAP maintained the HSC pool. However, Y352A NKAP did restore proliferation in murine embryonic fibroblasts when endogenous NKAP expression was eliminated using ER-cre and tamoxifen. Therefore, Y352 in NKAP is critical for association with HDAC3 and for HSC maintenance and survival but is not important for proliferation of murine embryonic fibroblasts, demonstrating that NKAP functions in different complexes in different cell types.
| S-EPMC6456368 | biostudies-literature
Project description:According to the "osteoblastic niche" model, hematopoietic stem cells (HSCs) are maintained by N-cadherin-mediated homophilic adhesion to osteoblasts at the bone marrow endosteum. In contrast to this model, we cannot detect N-cadherin expression by HSCs, and most HSCs do not localize to the endosteal surface. It has nonetheless been suggested that HSCs express low levels of N-cadherin that regulate HSC maintenance. To test this, we conditionally deleted N-cadherin from HSCs and other hematopoietic cells in adult Mx-1-Cre(+)N-cadherin(fl/-) mice. N-cadherin deficiency had no detectable effect on HSC maintenance or hematopoiesis. N-cadherin deficiency did not affect bone marrow cellularity or lineage composition, the numbers of colony-forming progenitors, the frequency of HSCs, the ability of HSCs to sustain hematopoiesis over time, or their ability to reconstitute irradiated mice in primary or secondary transplants. Loss of N-cadherin does not lead to HSC depletion. N-cadherin expression by HSCs is not necessary for niche function.
| S-EPMC2681089 | biostudies-literature