Project description:Aged hematopoietic stem cells (HSCs) exhibit compromised reconstitution capacity and differentiation-bias towards myeloid lineage. While, the molecular mechanism behind it remains not fully understood. In this study, we observed that the expression of pseudouridine (Ψ) synthase 10 is increased in aged hematopoietic stem and progenitor cells (HSPCs) and enforced PUS10 recapitulates the phenotype of aged HSCs, which is not achieved by its Ψ synthase activity. Consistently, we observed no difference of tRNA pseudouridylation profile between young and aged HSPCs. No significant alteration of hematopoietic homeostasis and HSC function is observed in young Pus10-/- mice, while aged Pus10-/-mice exhibit mild alteration of hematopoietic homeostasis and HSC function. Moreover, we observed that PUS10 is ubiquitinated by E3 ubiquitin ligase CRL4DCAF1 complex and the increase of PUS10 in aged HSPCs is due to aging-declined CRL4DCAF1-mediated ubiquitination degradation signaling. Taken together, this study for the first time evaluated the role of PUS10 in HSC aging and function, and provided novel insight for HSC rejuvenation and clinical application.
Project description:Aged hematopoietic stem cells (HSCs) exhibit compromised reconstitution capacity and differentiation-bias towards myeloid lineage. However, the molecular mechanism behind it remains not fully understood. In this study, we evaluated the expression of 5 pseudouridine (Ψ) synthases between young and aged HSCs, and observed that three of them are increased during aging. Functional evaluation assay reveals that enforced PUS10 and PUS7 recapitulate the phenotype aged HSCs. The increase of PUS10 in aged HSCs is due to aging-declined CRL4DCAF1-mediated ubiquitination degradation signaling. Mechanistically, the destructive role of enforced PUS10 on HSCs is not achieved by its Ψ synthases activity, but through miR139, dysfunction of which impairs the reconstitution capacity of HSCs. Consistently, we observed no difference of tRNA pseudouridylation profile between young and aged HSPCs, while enforced PUS10 alters the microRNA profile in HSCs. Targeted dysfunction of Pus10 results in compromises the self-renewal capacity of HSC.
Project description:Aged hematopoietic stem cells (HSCs) exhibit compromised reconstitution capacity and differentiation-bias towards myeloid lineage. However, the molecular mechanism behind it remains not fully understood. In this study, we evaluated the expression of 5 pseudouridine (Ψ) synthases between young and aged HSCs, and observed that three of them are increased during aging. Functional evaluation assay reveals that enforced PUS10 and PUS7 recapitulate the phenotype aged HSCs. The increase of PUS10 in aged HSCs is due to aging-declined CRL4DCAF1-mediated ubiquitination degradation signaling. Mechanistically, the destructive role of enforced PUS10 on HSCs is not achieved by its Ψ synthases activity, but through miR139, dysfunction of which impairs the reconstitution capacity of HSCs. Consistently, we observed no difference of tRNA pseudouridylation profile between young and aged HSPCs, while enforced PUS10 alters the microRNA profile in HSCs. Targeted dysfunction of Pus10 results in compromises the self-renewal capacity of HSC.
Project description:Aged hematopoietic stem cells (HSCs) exhibit compromised reconstitution capacity and differentiation-bias towards myeloid lineage. However, the molecular mechanism behind it remains not fully understood. In this study, we evaluated the expression of 5 pseudouridine (Ψ) synthases between young and aged HSCs, and observed that three of them are increased during aging. Functional evaluation assay reveals that enforced PUS10 and PUS7 recapitulate the phenotype aged HSCs. The increase of PUS10 in aged HSCs is due to aging-declined CRL4DCAF1-mediated ubiquitination degradation signaling. Mechanistically, the destructive role of enforced PUS10 on HSCs is not achieved by its Ψ synthases activity, but through miR139, dysfunction of which impairs the reconstitution capacity of HSCs. Consistently, we observed no difference of tRNA pseudouridylation profile between young and aged HSPCs, while enforced PUS10 alters the microRNA profile in HSCs. Targeted dysfunction of Pus10 results in compromises the self-renewal capacity of HSC.
Project description:In an effort to produce a mouse model of Mitochondrial Myopathy with Lactic acidosis and Sideroblastic Anemia (MLASA), we knocked out the gene for Pseudouridine synthase 1 (PUS1), an enzyme that modifies uridine to pseudouridine in many cytoplasmic and mitochondrial tRNAs, as well as other cellular RNAs. The Pus1-/- mice are viable, are born at the expected Mendelian frequency, and are non-dysmorphic. The PUS1 mRNA and certain pseudouridine modifications are absent in cytoplasmic and mitochondrial tRNAs in the Pus1-/- mice. The Pus1-/- mice display reduce exercise capacity at 14 weeks, with alterations in muscle morphology, histology, and physiology. Red gastrocnemius muscle from Pus1-/- mice shows reduced number and size of mitochondria and reduced Cytochrome C oxidase activity. Two-condition, two-color experiment: Mouse wild type PUS1 and homozygous mutant PUS1 kidney tissue samples: 4 biological replicates each.