Distinct roles for S100a8 in early embryo development and in the maternal deciduum.
S100a8 is a cytosolic protein expressed in myeloid cells where it forms a stable heterodimer with another S100 protein family member, S100a9. The S100a9(-/-) mouse is viable and phenotypically normal, whereas the S100a8(-/-) condition is embryonic lethal. We present evidence that S100a8, without S100a9, has a previously unrecognized role in embryo development between fertilization and the 8-cell stage at embryonic day (E) 2.5. S100a8 also has a second role in the maternal deciduum, where expression is associated with the vasculature from the E8.5 stage to the formation of mature placenta. Uterine natural killer cells that have a role in vascular remodelling colocalise with the S100a8 vascular expression in the metrial triangle. In inflammatory responses in peripheral tissues, S100a8 is a potent chemoattractant and also an anti-oxidant. Both roles may be important in the developing placenta. Thus we highlight two new S100a9-independent roles for S100a8 in early embryo development.
Leukocyte Adhesion Laboratory, Cancer Research UK London Research Institute, London, England.
J R
JR
Baker
R
R
Jeffery
R D
RD
May
M
M
Mathies
B
B
Spencer-Dene
R
R
Poulsom
N
N
Hogg
D000818:Animals; D015153:Blotting, Western; D040501:Calgranulin A / Q000235:genetics / Q000378:metabolism*; D040502:Calgranulin B / Q000235:genetics / Q000378:metabolism; D003656:Decidua / Q000378:metabolism*; D047108:Embryonic Development / Q000235:genetics / Q000502:physiology*; D005260:Female; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D051379:Mice; D016133:Polymerase Chain Reaction; D011247:Pregnancy
D040501:Calgranulin A; D040502:Calgranulin B; C086145:S100a8 protein, mouse