Salidroside enhances HSC repopulation. (A) Salidroside enhances the repopulating ability in recipient mice. LSK (Lin-Sca1+c-kit+) cells from WT C57BL/6 mice (CD45.2+) pretreated with or without salidroside (75μg/g body weight) followed by H2O2 (0.25 μmol/g body weight) treatment were isolated by cell sorting using FlowAria II. One thousand sorted LSK cells plus 1 million c-kit–depleted competitors (CD45.1+) were injected to lethally irradiated recipients. Donor chimerism was examined at 4 months after transplantation using peripheral blood from recipients. Representative images (left) and quantifications (right) were shown. Results are means ± SD of 3 independent experiments (n = 15 per group). (B) Salidroside increases HSC-enriched LSK cells in recipient mice. One thousand sorted LSK cells from WT C57BL/6 mice (CD45.2+) pretreated with or without salidroside followed by H2O2 treatment were injected along with 1 million c-kit–depleted competitors (CD45.1+) to lethally irradiated recipients. BM cells from recipient mice were harvested and subjected to flow cytometry analysis for LSK frequency. (C) Salidroside enhances competitive reconstitution of stressed HSCs. Various numbers of donor (CD45.2+) LSK cells (50, 100, or 1000) from stressed WT C57BL/6 mice were mixed with 1000 competitor LSK (CD45.1+) cells and the mixtures were transplanted intravenously into lethally irradiated congenic (CD45.1+) recipients. Donor-derived hematopoietic reconstitution was analyzed by flow cytometry 8 and 16 weeks after transplantation using peripheral blood from recipients. (D) Salidroside increases HSC-enriched LSK in recipient mice. BM cells from recipient mice described in panel C were subjected to flow cytometry analysis for LSK frequency. (E-F) Salidroside enhances LT-HSC repopulation. BM cells from primary recipient mice described in panel B were used for secondary transplantation by injecting 5 × 106 BM cells to lethally irradiated recipients. Donor-derived chimerism (E) and LSK (F) were analyzed by flow cytometry 16 weeks after BMT. Results are means ± SD of 2 independent experiments (n = 10 per group).
