Fig. 4.

Panel a. Activation of ComC as measured by increase in concentration of C5a cleavage fragments in PB. Control values in non-mobilized WT mice were assumed to be 1.0. Mice were mobilized with G-CSF for 6 days (50 μg/kg/day subcutaneously). * p < 0.05 as compared to WT mice. Panel b – Chemotactic responsiveness of Gr-1⁺ granulocytes from control and HO-1-defcient mice. Chemotaxis to SDF-1 (300 ng/ml), C5a (120 ng/ml), _desArgC5a (140 ng/ml) and S1P (0.1 μM) was perfomed with Gr-1⁺ cells purified from HO-1^+/+ (WT), HO-1^+/− and HO-1^−/− mice and number of cells that migrated spontaneously to lower chambers containing medium only was assumed to be 100 %. * p < 0.05 as compared to WT mice. Panel c. HO-1 deficiency increases chemotactic activity of bone marrow HSPC. Chemotaxis to SDF-1 (300 ng/ml) or S1P (0.1 μM) gradient was performed with bone marrow mononuclear cells isolated from HO-1^+/+ (WT), HO-1^+/− and HO-1^−/− mice and number of CFU-GM that migrated to SDF-1 or S1P in HO-1^+/+ (WT) was assumed to be 100 %. Number of CFU-GM migrated to SDF-1 gradient was evaluated in clonogenic assay in methylcellulose cultures in presence of IL-3 (5 ng/mL) and GM-CSF (5 ng/mL). * p < 0.05. Data represent average of three independent experiments performed in triplicate. Panel c. HO-1 inhibition by SnPP enhances migration of normal CFU-GM to SDF-1 gradient. Number of CFU-GM that migrated to SDF-1 (300 ng/ml) gradient in absence or presence of SnPP (25 μM) was evaluated in clonogenic assay in methylcellulose cultures in presence of IL-3 (5 ng/mL) and GM-CSF (5 ng/mL). * p < 0.05. Data represent average of three independent experiments performed in triplicate. Migration of cells to SDF-1 gradient has been assumed to be 100 %