Insufficient production of IL-10 from M2 macrophages impairs in vitro endothelial progenitor cell differentiation in patients with Moyamoya disease

Moyamoya disease (MMD) is well known to be caused by insufficient cerebral vascular formation. However, the essential pathogenesis has not yet been identified. Using our recently developed technique of generating vasculogenic and anti-inflammatory cultures, we investigated endothelial progenitor cell (EPC) expansion and differentiation under the cytokine milieu generated by the peripheral blood mononuclear cells (PBMNCs) of the operated and non-operated MMD patients. EPC colony forming assay of the cultured PBMNCs disclosed the decline of the definitive EPC colony numbers in the both MMD patients. The level of interleukin-10 (IL-10) was lower in secretory cytokines from the cultured PBMNCs of MMD patients than that in that of controls using a cytometric bead array. The addition of human recombinant IL-10 to PBMNCs cultured from MMD patients restored the EPC colony forming potential of MMD PBMNCs. Following phorbol myristate acetate stimulation of the cultured PBMNCs, flow cytometry revealed a decrease in intracellular IL-10 storage in the main cell populations of the PBMNCs cultured from MMD patients relative to those cultured from controls. The present data provide the expected mechanism of vascular malformation in MMD pathogenesis originated from the insufficient production of IL-10 secreting cells from PBMNCs fostering EPC expansion and differentiation.