Figure 2

Crlr/Ramp1 signaling is essential for maintenance hematopoietic cells under stress conditions. (a) Expression levels of CGRP in BM stromal cells of WT mice with 10 Gy irradiation and without irradiation were determined by immunoblot analysis. BMMNCs from three mice for each group were analyzed. The full-length gels/blots are presented in Supplemental Fig. S4. (b) Expression levels of proCGRP mRNA were determined in BM stromal cells of WT mice treated with 10 Gy irradiation and without irradiation were determined by real-time PCR. ***p < 0.001 compared with control (Student’s t test). (c) The numbers of BMMNCs were compared between WT and Ramp1^−/− mice at seven days after 5-FU injection. Data are shown as means ± SD of four mice. *p < 0.05, compared with WT mice (Student’s t test). (d) Under the same experiment in (c), the cell numbers and percentages of LSK or myeloid progenitors (MP) fractions were compared between WT and Ramp1^−/− mice at seven days after 5-FU injection. The percentages of CMP, GMP, and MEP cells in the MP fraction were compared between the two groups. Data are shown as means ± SD of four mice. *p < 0.05, **p < 0.01, ***p < 0.001 compared with WT mice (Student’s t test). (e) Chimerism (percent donor-derived cells, CD45.2) from Ramp1^−/− and WT mice in BMMNCs, myeloid cells, B lymphocytes, and T lymphocytes from the PB of lethally irradiated WT recipients (CD45.1) at each indicated time point after transplantation (1, 2, 3, and 4 months). Donor/recipient ratio: 50:50. Data are shown as means ± SD of four mice. *p < 0.05, **p < 0.01 compared with WT mice (Student’s t test). (f) The proportion of donor-derived myeloid, B lymphocytes, and T lymphocytes (Ramp1^−/− and WT mice) among donor-derived WBCs in the PB of lethally irradiated WT recipients at four months after transplantation. Data are shown as means ± SD of four mice. (g) Chimerism (percent donor-derived cells, CD45.2) from Ramp1^−/− and WT mice in BMMNCs, Lin⁺, Lin⁻, MP, and LSK cells in BMMNCs from lethally irradiated WT recipients (CD45.1). Donor/recipient ratio: 50:50. Data are shown as means ± SD of four mice. *p < 0.05, **p < 0.01 compared with WT mice (Student’s t test). (h) Chimerism (percent donor-derived cells, CD45.2) from Ramp1^−/− and WT mice in BMMNCs of lethally irradiated WT recipients (CD45.1) at each indicated time point after second transplantation (1, 2, 3, and 4 months). Donor/recipient ratio: 50:50. Data are shown as means ± SD of three mice. ***p < 0.001 compared with WT mice (Student’s t test).