Early Development of Resident Macrophages in the Mouse Cochlea Depends on Yolk Sac Hematopoiesis

DOI HANDLE Web Site 6 Citations 45 References Open Access
  • Kishimoto, Ippei
    Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University
  • Okano, Takayuki
    Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University
  • Nishimura, Koji
    Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University
  • Motohashi, Tsutomu
    Department of Tissue and Organ Development, Regeneration, and Advanced Medical Science, Graduate School of Medicine, Gifu University
  • Omori, Koichi
    Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University

Abstract

Resident macrophages reside in all tissues throughout the body and play a central role in both tissue homeostasis and inflammation. Although the inner ear was once believed to be “immune-privileged, ” recent studies have shown that macrophages are distributed in the cochlea and may play important roles in the immune system thereof. Resident macrophages have heterogeneous origins among tissues and throughout developmental stages. However, the origins of embryonic cochlear macrophages remain unknown. Here, we show that the early development of resident macrophages in the mouse cochlea depends on yolk sac hematopoiesis. Accordingly, our results found that macrophages emerging around the developing otocyst at E10.5 exhibited dynamic changes in distribution and in situ proliferative capacity during embryonic and neonatal stages. Cochlear examination in Csf1r-null mice revealed a substantial decrease in the number of Iba1-positive macrophages in the spiral ganglion and spiral ligament, whereas they were still observed in the cochlear mesenchyme or on the intraluminal surface of the perilymphatic space. Our results demonstrated that two subtypes of resident macrophages are present in the embryonic cochlea, one being Csf1r-dependent macrophages that originate from the yolk sac and the other being Csf1r-independent macrophages that appear to be derived from the fetal liver via systemic circulation. We consider the present study to be a starting point for elucidating the roles of embryonic cochlear resident macrophages. Furthermore, resident macrophages in the embryonic cochlea could be a novel target for the treatment of various inner ear disorders.

Journal

Citations (6)*help

See more

References(45)*help

See more

Related Projects

See more

Keywords

Details 詳細情報について

Report a problem

Back to top