Lnk deficiency partially mitigates hematopoietic stem cell aging.
Upon aging, the number of hematopoietic stem cells (HSCs) in the bone marrow increases while their repopulation potential declines. Moreover, aged HSCs exhibit lineage bias in reconstitution experiments with an inclination toward myeloid at the expense of lymphoid potential. The adaptor protein Lnk is an important negative regulator of HSC homeostasis, as Lnk deficiency is associated with a 10-fold increase in HSC numbers in young mice. However, the age-related increase in functional HSC numbers found in wild-type HSCs was not observed in Lnk-deficient animals. Importantly, HSCs from aged Lnk null mice possess greatly enhanced self-renewal capacity and diminished exhaustion, as evidenced by serial transplant experiments. In addition, Lnk deficiency ameliorates the aging-associated lineage bias. Transcriptome analysis revealed that WT and Lnk-deficient HSCs share many aging-related changes in gene expression patterns. Nonetheless, Lnk null HSCs displayed altered expression of components in select signaling pathways with potential involvement in HSC self-renewal and aging. Taken together, these results suggest that loss of Lnk partially mitigates age-related HSC alterations.
Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104-4318, USA.
Alexey
A
Bersenev
Krasimira
K
Rozenova
Joanna
J
Balcerek
Jing
J
Jiang
Chao
C
Wu
Wei
W
Tong
D048868:Adaptor Proteins, Signal Transducing; D000328:Adult; D000375:Aging / Q000235:genetics*; D000818:Animals; D002452:Cell Count; D019070:Cell Lineage / Q000235:genetics*; D049109:Cell Proliferation; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D005838:Genotype; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D008565:Membrane Proteins; D051379:Mice; D018345:Mice, Knockout; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D015398:Signal Transduction; D059467:Transcriptome
D048868:Adaptor Proteins, Signal Transducing; D047908:Intracellular Signaling Peptides and Proteins; C490777:Lnk protein, mouse; D008565:Membrane Proteins