Purinergic P2Y14 receptor modulates stress-induced hematopoietic stem/progenitor cell senescence
Joonseok Cho, Rushdia Yusuf, Sungho Kook, Eyal Attar, Dongjun Lee, Baehang Park, Tao Cheng, David T. Scadden, Byeong Chel Lee
Joonseok Cho, Rushdia Yusuf, Sungho Kook, Eyal Attar, Dongjun Lee, Baehang Park, Tao Cheng, David T. Scadden, Byeong Chel Lee
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Research Article

Purinergic P2Y14 receptor modulates stress-induced hematopoietic stem/progenitor cell senescence

Abstract

Purinergic receptors of the P2Y family are G protein–coupled surface receptors that respond to extracellular nucleotides and can mediate responses to local cell damage. P2Y-dependent signaling contributes to thrombotic and/or inflammatory consequences of tissue injury by altering platelet and endothelial activation and immune cell phagocytosis. Here, we have demonstrated that P2Y14 modifies cell senescence and cell death in response to tissue stress, thereby enabling preservation of hematopoietic stem/progenitor cell function. In mice, P2Y14 deficiency had no demonstrable effect under homeostatic conditions; however, radiation stress, aging, sequential exposure to chemotherapy, and serial bone marrow transplantation increased senescence in animals lacking P2Y14. Enhanced senescence coincided with increased ROS, elevated p16INK4a expression, and hypophosphorylated Rb and was inhibited by treatment with a ROS scavenger or inhibition of p38/MAPK and JNK. Treatment of WT cells with pertussis toxin recapitulated the P2Y14 phenotype, suggesting that P2Y14 mediates antisenescence effects through Gi/o protein–dependent pathways. Primitive hematopoietic cells lacking P2Y14 were compromised in their ability to restore hematopoiesis in irradiated mice. Together, these data indicate that P2Y14 on stem/progenitor cells of the hematopoietic system inhibits cell senescence by monitoring and responding to the extracellular manifestations of tissue stress and suggest that P2Y14-mediated responses prevent the premature decline of regenerative capacity after injury.

Authors

Joonseok Cho, Rushdia Yusuf, Sungho Kook, Eyal Attar, Dongjun Lee, Baehang Park, Tao Cheng, David T. Scadden, Byeong Chel Lee

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Figure 5

Impact of P2Y14 deficiency on radiation-induced senescence during embryonic development.

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Impact of P2Y14 deficiency on radiation-induced senescence during embryo...
(A and B) HT mice were mated, and pregnant female mice were either untreated or treated (IR) with single TBI at a dose of 1.5 Gy on day 11.5 of gestation. The yolk sac was dissected and used as a source of DNA for genotyping. (A) E18.5 embryos isolated from untreated (upper) and treated (1.5 Gy TBI, lower) pregnant dams were weighed. (B) Representative images of SA–β-gal stained embryos are shown. Numbers below the bottom panel denote percentage of SA–β-gal positive embryos for each indicated genotype. Numbers in parentheses indicate the number of positively stained embryos/total number of embryo stained. (C) MEFs were prepared from E12.5–E13.5 P2ry14–/– and WT embryos. Cell numbers were determined at each passage prior to redilution. The 2-tailed Student’s t test was used. (D) SA–β-gal staining of WT and P2ry14–/– MEF cells: MEF cells at passage 4 were subjected to SA–β-gal staining (left). The number of SA–β-gal–positive cells was counted, and the percentage of SA– β-gal positive cells is shown on the y axis (right). At least 50 cells from 3 random fields were counted. The 2-tailed Student’s t test was used. Note that P2ry14–/– MEFs developed a senescence-like morphology, such as a large and flattened morphology (left). Data are representative of 4 independent experiments. Scale bars: 50 μm (left panels); 20 μm (right panels). *P < 0.05.