Exp Hematol. 2015 Nov 22. pii: S0301-472X(15)00744-4. doi: 10.1016/j.exphem.2015.11.007. [Epub ahead of print]

Hematopoietic niches, Erythropoiesis and Anemia of Chronic Infection.

Gomes AC¹, Gomes MS².

Abstract

Anemia is an important co-morbidity of chronic infections, as well as other inflammatory diseases. Anemia of chronic infections results from defective bone marrow erythropoiesis. Although the limitation of iron availability has been considered one key factor, the exact mechanisms underlying blockade in erythroid generation during infection are not fully understood. Erythropoiesis is a tightly regulated process, which is very sensitive to environmental changes. During the last decade, the importance of the bone marrow hematopoietic niche has been progressively acknowledged. Several bone marrow cell types (such as Macrophages or Mesenchymal Stem and Progenitors Cells) and molecular mediators (such as CXCL12) have been identified as fundamental for both the maintenance of Hematopoietic Stem Cells pluripotency and for their most adequate differentiation into each hematopoietic cell lineage. Importantly, both niche supporting cells and hematopoietic progenitors were found to be able to sense local and systemic cues in order to adapt the hematopoietic output to the organism needs. Here, we review how hematopoietic progenitors and niche supporting cells sense and respond to stress cues, and suggest a potential role for the hematopoietic niche in the development of anemia of chronic infections.