Fig. 6

Increased LTB4 synthesis leads to HSPC defects in Drosha cKO embryos. a mRNA levels of LT receptors in ECs (CD31⁺Kit⁻CD45⁻) and HSPCs (CD31⁺Kit⁺CD45⁻) from Ctr or cKO embryos. Mean ± SEM. n = Ctr: 12 embryos, cKO: 6 embryos. 3 litters. b HSPCs (CD31⁺Kit⁺CD45⁻) from E11.5 AGM were subjected to ELISA analysis, and the concentration of LTB4 (pM) was plotted as Mean ± SEM. n = Ctr: 6 embryos, cKO: 4 embryos. 3 litters. c E9.5 WT AGMs were incubated with LTB4 or vehicle for 20 h ex vivo, followed by CFU assay (bottom panel). Relative colony number was plotted as Mean ± SEM; p values were generated by unpaired Student’s t test. n = 8 embryos (vehicle) and 9 embryos (LTB4), 3 litters for 1 nM LTB4. n = 7 embryos (vehicle) and 8 embryos (LTB4), 2 litters for 10 nM LTB4. n = 8 embryos (vehicle) and 7 embryos (LTB4), 2 litters for 100 nM LTB4. d Flow cytometric analysis on E10.5 WT AGMs treated with 1 nM LTB4 (bottom left) or 100 nM LTB4 (bottom right). The fraction (%) of CD31⁺Kit⁺CD45⁻ cells among CD31⁺ cells was plotted as Mean ± SEM; p values were generated by unpaired Student’s t test. n = 7 embryos (vehicle) and 6 embryos (LTB4), 2 litters for 1 nM LTB4. n = 8 embryos (vehicle) and 7 embryos (LTB4), 2 litters for 100 nM LTB4. e LTB4 or vehicle was injected to pregnant WT mice at E8.5, E9.5, and E10.5. 20 and 10% of cells from AGM and FL from E11.5 embryo were subjected to CFU assay, respectively. Colony number was plotted as Mean ± SEM; p values were generated by unpaired Student’s t test. n = 10 embryos from 2 vehicle-injected litters, n = 10 embryos from 2 LTB4-injected litters. f E10.5 Ctr or cKO AGMs were incubated with U75302 or vehicle, followed by CFU assay. Colony number was plotted as Mean ± SEM; p values were generated by unpaired Student’s t test. For U75302 treatment, n = Ctr: 5 embryos, cKO: 4 embryos. 3 litters. For vehicle, n = Ctr: 7 embryos, cKO: 4 embryos. 2 litters