Medicinal & Aromatic Plants
Open Access

Abstract

Extramedular Hematopoiesis in the Spleen of Obese Mice Modulation by the Alga Chlorella

Cristiane O Torello, Edgar J Paredes-Gamero, Fernanda Martins, Tamara C Lopes de Castro, Mario JA Saad, Sara TO Saad, Claudia Bincoletto and Mary LS Queiroz

In this study, Balb/C mice received standard or high-fat diet (HFD) and were treated with Chlorella for 5 days prior and 4 weeks after the onset of HFD. Our findings demonstrate that in HFD-induced obesity, there is a rapid decline in the number of granulocyte and macrophage progenitors (CFU-GM) in the bone marrow, which is associated with a continuous migration/increase of these cells into the spleen, a process characterized as extramedullary hematopoiesis (EMH). No changes in the size of the primitive (LSK), and reduction in the size of the granulocyte/macrophage (GMP) hematopoietic populations in the bone marrow were observed. We also found that increased expression of C-C chemokine receptor type 2 (CCR2) on GMP in the spleen might be a mechanism related to the migration of CFU-GM to this organ. Increased serum colony-stimulating activity (CSA) was also found in obese mice. IL-6 serum levels, measured at the end of the treatment (12 weeks) when impaired glucose tolerance was already established (Vecina et al.), was increased. Treatment with Chlorella restored to normal values the numbers of CFU-GM in the marrow and spleen, the percentage of GMP in the marrow, the expression of CCR2 on spleen GMP, the increased serum levels of IL-6, and further increased CSA compared to obese mice. These findings suggest the ability of Chlorella to modulate the shift in hematopoietic topographical hierarchy, probably due its anti-inflammatory properties.