| 1. |
- Koide, Shuhei, et al.
(författare)
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CD244 expression represents functional decline of murine hematopoietic stem cells after in vitro culture
- 2022
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Ingår i: iScience. - : Elsevier BV. - 2589-0042. ; 25:1
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Tidskriftsartikel (refereegranskat)abstract
- Isolation of long-term hematopoietic stem cell (HSC) is possible by utilizing flow cytometry with multiple cell surface markers. However, those cell surface phenotypes do not represent functional HSCs after in vitro culture. Here we show that cultured HSCs express mast cell-related genes including Cd244. After in vitro culture, phenotypic HSCs were divided into CD244- and CD244+ subpopulations, and only CD244- cells that have low mast cell gene expression and maintain HSC-related genes sustain reconstitution potential. The result was same when HSCs were cultured in an efficient expansion medium containing polyvinyl alcohol. Chemically induced endoplasmic reticulum (ER) stress signal increased the CD244+ subpopulation, whereas ER stress suppression using a molecular chaperone, TUDCA, decreased CD244+ population, which was correlated to improved reconstitution output. These data suggest CD244 is a potent marker to exclude non-functional HSCs after in vitro culture thereby useful to elucidate mechanism of functional decline of HSCs during ex vivo treatment.
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| 2. |
- Radulovic, Visnja, et al.
(författare)
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Junctional Adhesion Molecule 2 Represents a Subset of Hematopoietic Stem Cells with Enhanced Potential for T Lymphopoiesis
- 2019
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Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 27:10, s. 5-2836
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Tidskriftsartikel (refereegranskat)abstract
- The distinct lineage potential is a key feature of hematopoietic stem cell (HSC) heterogeneity, but a subset of HSCs specialized for a single lymphoid compartment has not been identified. Here we report that HSCs expressing junctional adhesion molecule 2 (Jam2) at a higher level (Jam2high HSCs) have a greater T cell reconstitution capacity. Jam2high HSCs are metabolically dormant but preferentially differentiate toward lymphocytes, especially T cell lineages. Jam2high HSCs uniquely express T cell-related genes, and the interaction with Jam1 facilitates the Notch/Delta signaling pathway. Frequency of Jam2high HSCs changes upon T cell depletion in vivo, potentially suggesting that Jam2 expression may reflect scarcity of T cells and requirement of T cell replenishment. Our findings highlight Jam2 as a potential marker for a subfraction of HSCs with an extensive lymphopoietic capacity, mainly in T lymphopoiesis. Radulovic et al. show that hematopoietic stem cells expressing Jam2 at a higher level on their cell surface (Jam2high HSCs) have a greater lymphopoietic potential, particularly T cells. Interaction with Jam1 facilitates Notch/Delta signals, which might be the potential mechanism. The frequency of Jam2high HSCs changes upon selective hematopoietic stress.
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| 3. |
- Sigurdsson, Valgardur, et al.
(författare)
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Bile Acids Protect Expanding Hematopoietic Stem Cells from Unfolded Protein Stress in Fetal Liver.
- 2016
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Ingår i: Cell Stem Cell. - : Elsevier BV. - 1934-5909. ; 18:4, s. 32-522
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Tidskriftsartikel (refereegranskat)abstract
- During development, hematopoietic stem cells (HSCs) undergo a rapid expansion in the fetal liver (FL) before settling in the adult bone marrow. We recently reported that proliferating adult HSCs are vulnerable to ER stress caused by accumulation of mis-folded proteins. Here, we find that FL-HSCs, despite an increased protein synthesis rate and a requirement for protein folding, do not upregulate ER chaperones. Instead, bile acids (BAs), secreted from maternal and fetal liver, coordinate to serve as chemical chaperones. Taurocholic acid, the major BA in FL, supports growth of HSCs in vitro by inhibiting protein aggregation. In vivo, reducing BA levels leads to ER stress elevation and accumulation of aggregated proteins and significantly decreases the number of FL-HSCs. Taken together, these findings reveal that BA alleviation of ER stress is a mechanism required for HSC expansion during fetal hematopoiesis.
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| 4. |
- Sigurdsson, Valgardur, et al.
(författare)
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Induction of blood-circulating bile acids supports recovery from myelosuppressive chemotherapy
- 2020
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Ingår i: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 4:9, s. 1833-1843
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Tidskriftsartikel (refereegranskat)abstract
- Chemotherapeutic agents can reduce bone marrow (BM) activity, causing myelosuppression, a common life-threatening complication of cancer treatment. It is challenging to predict the patients in whom prolonged myelosuppression will occur, resulting in a delay or discontinuation of the treatment protocol. An early indicator of recovery from myelosuppression would thus be highly beneficial in clinical settings. In this study, bile acids (BAs) were highly increased in the systemic circulation as a natural response during recovery from myelosuppression, supporting regeneration of BM cells. BA levels in the blood of pediatric cancer patients and mice treated with chemotherapeutic agents were increased, in synchrony with early proliferation of BM cells and recovery from myelosuppression. In a mouse model of altered BA composition, Cyp8b1 knockout mice, a subset of mice recovered poorly after chemotherapy. The poor recovery correlated with low levels and changes in composition of BAs in the liver and systemic circulation. Conversely, BA supplementation in chemotherapy-treated wild-type mice resulted in significantly improved recovery. The results suggest that part of the mechanism by which BAs support recovery is the suppression of endoplasmic reticulum stress pathways in expanding and recovering hematopoietic cells. The findings propose a novel role of BAs as early markers of recovery and active components of the recovery process after chemotherapy.
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