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Human and Murine Hematopoietic Stem Cell Aging Is Associated with Functional Impairments and Intrinsic Megakaryocytic/Erythroid Bias.

Rundberg Nilsson A, Soneji S, Adolfsson S, Bryder D, Pronk CJ - PLoS ONE (2016)

Bottom Line: This was accompanied by functional impairments, including decreased lymphoid output and reduced proliferative potential.Downstream of human HSCs, we observed decreasing levels of common lymphoid progenitors (CLPs), and increasing frequencies of megakaryocyte/erythrocyte progenitors (MEPs) with age, which could be linked to changes in lineage-affiliated gene expression patterns in aged human HSCs.Therefore, our data support the notion that age-related changes also in human hematopoiesis involve the HSC pool, with a prominent skewing towards the megakaryocytic/erythroid lineages, and suggests conserved mechanisms underlying aging of the blood cell system.

View Article: PubMed Central - PubMed

Affiliation: Medical Faculty, Division of Molecular Hematology, Institution for Laboratory Medicine, Lund University, Lund, Sweden.

ABSTRACT
Aging within the human hematopoietic system associates with various deficiencies and disease states, including anemia, myeloid neoplasms and reduced adaptive immune responses. Similar phenotypes are observed in mice and have been linked to alterations arising at the hematopoietic stem cell (HSC) level. Such an association is, however, less established in human hematopoiesis and prompted us here to detail characteristics of the most primitive human hematopoietic compartments throughout ontogeny. In addition, we also attempted to interrogate similarities between aging human and murine hematopoiesis. Coupled to the transition from human cord blood (CB) to young and aged bone marrow (BM), we observed a gradual increase in frequency of candidate HSCs. This was accompanied by functional impairments, including decreased lymphoid output and reduced proliferative potential. Downstream of human HSCs, we observed decreasing levels of common lymphoid progenitors (CLPs), and increasing frequencies of megakaryocyte/erythrocyte progenitors (MEPs) with age, which could be linked to changes in lineage-affiliated gene expression patterns in aged human HSCs. These findings were paralleled in mice. Therefore, our data support the notion that age-related changes also in human hematopoiesis involve the HSC pool, with a prominent skewing towards the megakaryocytic/erythroid lineages, and suggests conserved mechanisms underlying aging of the blood cell system.

No MeSH data available.


Related in: MedlinePlus

(A-B) Proliferation of human HSCs at different ontogenic stages.(A) Fractions of candidate h-HSCs (cloning frequency) that proliferate in vitro. Cloning frequency was determined as the frequency of wells in which single cells had been sorted and two or more cells was observed after eleven days in culture. (B) Clonal size of proliferating h-HSCs, scored as wells containing either 2–50 cells or >50 cells among wells that showed proliferation. Error bars represent +SEM. CB n = 6, young n = 4, aged n = 4. (C) Lymphoid potential of candidate HSCs. 10 h-HSCs each were sorted into multiple wells (20–60/donor) and scored after 5 weeks in culture. Graph depicts lineage distribution from wells with proliferation. Error bars represent -SEM. CB n = 6, young n = 10, aged n = 6. Analyses were done with unpaired t-tests. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001. (D-E) Up- and downregulated GO terms in aged human BM HSCs. Differentially expressed genes between young and aged human HSCs with adjusted p-values < 0.1 were subjected to analysis of enriched gene ontology (GO) terms using DAVID. (D) Top 20 GO terms of upregulated genes in aged HSCs. (E) GO terms of conserved downregulated genes in aged HSCs.
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pone.0158369.g002: (A-B) Proliferation of human HSCs at different ontogenic stages.(A) Fractions of candidate h-HSCs (cloning frequency) that proliferate in vitro. Cloning frequency was determined as the frequency of wells in which single cells had been sorted and two or more cells was observed after eleven days in culture. (B) Clonal size of proliferating h-HSCs, scored as wells containing either 2–50 cells or >50 cells among wells that showed proliferation. Error bars represent +SEM. CB n = 6, young n = 4, aged n = 4. (C) Lymphoid potential of candidate HSCs. 10 h-HSCs each were sorted into multiple wells (20–60/donor) and scored after 5 weeks in culture. Graph depicts lineage distribution from wells with proliferation. Error bars represent -SEM. CB n = 6, young n = 10, aged n = 6. Analyses were done with unpaired t-tests. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001. (D-E) Up- and downregulated GO terms in aged human BM HSCs. Differentially expressed genes between young and aged human HSCs with adjusted p-values < 0.1 were subjected to analysis of enriched gene ontology (GO) terms using DAVID. (D) Top 20 GO terms of upregulated genes in aged HSCs. (E) GO terms of conserved downregulated genes in aged HSCs.

Mentions: To explore a possible link between the observed alterations of h-HSC frequencies and performance, we next assessed h-HSC function at different ontogenic stages. In vitro evaluation of h-HSC cloning frequency (i.e. the proportion of h-HSCs that could be induced to proliferate) revealed decreasing cloning frequencies of 84.3 ± 2.09% in CB to 78.50 ± 2.10% in young BM (p < 0.01), and to 61.00 ± 6.52% in aged BM (p < 0.05; Fig 2A). H-HSC aging was also accompanied by a decreased proliferative capacity (i.e. the clone size of proliferating cells) (Fig 2B).


Human and Murine Hematopoietic Stem Cell Aging Is Associated with Functional Impairments and Intrinsic Megakaryocytic/Erythroid Bias.

Rundberg Nilsson A, Soneji S, Adolfsson S, Bryder D, Pronk CJ - PLoS ONE (2016)

(A-B) Proliferation of human HSCs at different ontogenic stages.(A) Fractions of candidate h-HSCs (cloning frequency) that proliferate in vitro. Cloning frequency was determined as the frequency of wells in which single cells had been sorted and two or more cells was observed after eleven days in culture. (B) Clonal size of proliferating h-HSCs, scored as wells containing either 2–50 cells or >50 cells among wells that showed proliferation. Error bars represent +SEM. CB n = 6, young n = 4, aged n = 4. (C) Lymphoid potential of candidate HSCs. 10 h-HSCs each were sorted into multiple wells (20–60/donor) and scored after 5 weeks in culture. Graph depicts lineage distribution from wells with proliferation. Error bars represent -SEM. CB n = 6, young n = 10, aged n = 6. Analyses were done with unpaired t-tests. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001. (D-E) Up- and downregulated GO terms in aged human BM HSCs. Differentially expressed genes between young and aged human HSCs with adjusted p-values < 0.1 were subjected to analysis of enriched gene ontology (GO) terms using DAVID. (D) Top 20 GO terms of upregulated genes in aged HSCs. (E) GO terms of conserved downregulated genes in aged HSCs.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4930192&req=5

pone.0158369.g002: (A-B) Proliferation of human HSCs at different ontogenic stages.(A) Fractions of candidate h-HSCs (cloning frequency) that proliferate in vitro. Cloning frequency was determined as the frequency of wells in which single cells had been sorted and two or more cells was observed after eleven days in culture. (B) Clonal size of proliferating h-HSCs, scored as wells containing either 2–50 cells or >50 cells among wells that showed proliferation. Error bars represent +SEM. CB n = 6, young n = 4, aged n = 4. (C) Lymphoid potential of candidate HSCs. 10 h-HSCs each were sorted into multiple wells (20–60/donor) and scored after 5 weeks in culture. Graph depicts lineage distribution from wells with proliferation. Error bars represent -SEM. CB n = 6, young n = 10, aged n = 6. Analyses were done with unpaired t-tests. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001. (D-E) Up- and downregulated GO terms in aged human BM HSCs. Differentially expressed genes between young and aged human HSCs with adjusted p-values < 0.1 were subjected to analysis of enriched gene ontology (GO) terms using DAVID. (D) Top 20 GO terms of upregulated genes in aged HSCs. (E) GO terms of conserved downregulated genes in aged HSCs.
Mentions: To explore a possible link between the observed alterations of h-HSC frequencies and performance, we next assessed h-HSC function at different ontogenic stages. In vitro evaluation of h-HSC cloning frequency (i.e. the proportion of h-HSCs that could be induced to proliferate) revealed decreasing cloning frequencies of 84.3 ± 2.09% in CB to 78.50 ± 2.10% in young BM (p < 0.01), and to 61.00 ± 6.52% in aged BM (p < 0.05; Fig 2A). H-HSC aging was also accompanied by a decreased proliferative capacity (i.e. the clone size of proliferating cells) (Fig 2B).

Bottom Line: This was accompanied by functional impairments, including decreased lymphoid output and reduced proliferative potential.Downstream of human HSCs, we observed decreasing levels of common lymphoid progenitors (CLPs), and increasing frequencies of megakaryocyte/erythrocyte progenitors (MEPs) with age, which could be linked to changes in lineage-affiliated gene expression patterns in aged human HSCs.Therefore, our data support the notion that age-related changes also in human hematopoiesis involve the HSC pool, with a prominent skewing towards the megakaryocytic/erythroid lineages, and suggests conserved mechanisms underlying aging of the blood cell system.

View Article: PubMed Central - PubMed

Affiliation: Medical Faculty, Division of Molecular Hematology, Institution for Laboratory Medicine, Lund University, Lund, Sweden.

ABSTRACT
Aging within the human hematopoietic system associates with various deficiencies and disease states, including anemia, myeloid neoplasms and reduced adaptive immune responses. Similar phenotypes are observed in mice and have been linked to alterations arising at the hematopoietic stem cell (HSC) level. Such an association is, however, less established in human hematopoiesis and prompted us here to detail characteristics of the most primitive human hematopoietic compartments throughout ontogeny. In addition, we also attempted to interrogate similarities between aging human and murine hematopoiesis. Coupled to the transition from human cord blood (CB) to young and aged bone marrow (BM), we observed a gradual increase in frequency of candidate HSCs. This was accompanied by functional impairments, including decreased lymphoid output and reduced proliferative potential. Downstream of human HSCs, we observed decreasing levels of common lymphoid progenitors (CLPs), and increasing frequencies of megakaryocyte/erythrocyte progenitors (MEPs) with age, which could be linked to changes in lineage-affiliated gene expression patterns in aged human HSCs. These findings were paralleled in mice. Therefore, our data support the notion that age-related changes also in human hematopoiesis involve the HSC pool, with a prominent skewing towards the megakaryocytic/erythroid lineages, and suggests conserved mechanisms underlying aging of the blood cell system.

No MeSH data available.


Related in: MedlinePlus