Hematopoietic stem/progenitor cell senescence is associated with altered expression profiles of cellular memory-involved gene

Yongpin Dong; Xiaolan Lian; Yanwu Xu; Haiyan Hu; Cen Chang; Haiyin Zhang; Lina Zhang

doi:10.1042/BSR20171589

Hematopoietic stem/progenitor cell senescence is associated with altered expression profiles of cellular memory-involved gene

Biosci Rep. 2018 Feb 21;38(1):BSR20171589. doi: 10.1042/BSR20171589. Print 2018 Feb 28.

Authors

Yongpin Dong¹, Xiaolan Lian², Yanwu Xu³, Haiyan Hu³, Cen Chang³, Haiyin Zhang³, Lina Zhang⁴

Affiliations

¹ Department of Emergency and Critical Care Medicine, Shanghai Changzheng Hospital, The Second Military Medical University, Shanghai 200003, China.
² Fujian Provincial Key Laboratory on Hematology, Fujian Institute of Hematology, Fujian Medical University Union Hospital, Fuzhou, China.
³ Department of Biochemistry, Institute of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
⁴ Department of Biochemistry, Institute of Basic Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China zln_1250@163.com.

Abstract

To evaluate the contributions of cellular memory mechanisms to hematopoietic stem/progenitor cell (HSPC) senescence. HSPCs (Lin^-CD117⁺, hereafter referred to as HSPC) were separated from young (6-week-old) and aged (18-month-old) mice using Magnetic Activated Cell Sorting (MACS). Cell cycle distribution of HSPCs was determined using flow cytometry. The mixed colony forming unit (CFU-Mix) assay was used to study the HSPCs' ability to proliferate. The mRNA expression levels of cellular memory-implicated PCG family (enhancer of zeste homolog 2 (Ezh2), B lymphoma mo-MLV insertion region 1 (Bmi-1), embryonic ectoderm development (Eed), melanoma nuclear protein 18 (Mel18), Mph1/polyhomeotic-like protein 1 (Rae-28)) and Trithorax group (TrxG) family (mixed lineage leukemia (Mll), thioredoxin (Trx)) were determined by quantitative real-time PCR. We obtained highly purified populations of mouse HSPCs (Lin^-CD117⁺) (92.2 ± 4.5% CD117⁺). The percentage of HSPCs was significantly higher in older mice compared with younger control mice and the percentage of SA-β-galactosidase positive cells was significantly higher in HSPCs isolated from older mice (P<0.05). The percentage of HSPCs in G₀/G₁ was significantly higher in older mice compared with younger control mice (52.0 compared with 47.1%), indicating increased cell cycle arrest in senescent HSPCs. The amount of CFU-Mix was significantly decreased in aged group (13.8 compared with 40.0), indicating a diminished ability to proliferate in senescent HSPCs. Ezh1, Bmi-1, Eed, Rae-28 gene mRNA expression was significantly lower in HSPCs from older mice compared to younger controls, while Mel18 mRNA expression was significantly higher in HSPCs from older mice (P<0.05). The expression of genes associated with cellular memory is altered in senescent (Lin^- CD117⁺) HSPCs, which may affect the potential plasticity of aged hematopoietic stem cells (HSCs) and thereby contribute to senescence-associated disease processes.

Keywords: cell senescence; cellular memory; hematopoietic stem/progenitor cells; β-galactosidase.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Cell Cycle
Cell Proliferation
Cellular Senescence / physiology*
Female
Hematopoietic Stem Cells / cytology
Hematopoietic Stem Cells / physiology*
Male
Mice
Mice, Inbred C57BL
Myeloid-Lymphoid Leukemia Protein / genetics
Myeloid-Lymphoid Leukemia Protein / metabolism
Polycomb-Group Proteins / genetics
Polycomb-Group Proteins / metabolism
RNA, Messenger / metabolism
Thioredoxins / genetics
Thioredoxins / metabolism
Transcriptome / genetics*

Substances

Polycomb-Group Proteins
RNA, Messenger
Myeloid-Lymphoid Leukemia Protein
Thioredoxins