Article
Sequential morphological characteristics of murine fetal hematopoietic microenvironment in Swiss Webster mice liver
Registro en:
SILVA, Jackline de Paula Ayres et al. Sequential morphological characteristics of murine fetal hematopoietic microenvironment in Swiss Webster mice liver.Cell and tissue research, v. 344, n.3, p. 455-469, June 2011.
1432-0878
Autor
Silva, Jackline de Paula Ayres
Manso, Pedro Paulo de Abreu
Madeira, Mariana Rietmann da Cunha
Machado, Marcelo Pelajo
Lenzi, Henrique Leonel
Resumen
This work was supported by Fiocruz and CNPq grants Embryonic hematopoiesis occurs via dynamic
development with cells migrating into various organs. Fetal
liver is the main hematopoietic organ responsible for
hematopoietic cell expansion during embryologic development.
We describe the morphological sequential characteristics
of murine fetal liver niches that favor the settlement
and migration of hematopoietic cells from 12 days postcoitum
(dpc) to 0 day post-partum. Liver sections were
stained with hematoxylin and eosin, Lennert’s Giemsa,
Sirius Red pH 10.2, Gomori’s Reticulin, and Periodic Acid
Schiff/Alcian Blue pH 1.0 and pH 2.5 and were analyzed
by bright-field microscopy. Indirect imunohistochemistry
for fibronectin, matrix metalloproteinase-1 (MMP-1), and
MMP-9 and histochemistry for naphthol AS-D chloroacetate
esterase (NCAE) were analyzed by confocal microscopy.
The results showed that fibronectin was related to the
promotion of hepatocyte and trabecular differentiation;
reticular fibers did not appear to participate in fetal
hematopoiesis but contributed to the physical support of
the liver after 18 dpc. During the immature phase,
hepatocytes acted as the fundamental stroma for the
erythroid lineage. The appearance of myeloid cells in the
liver was related to perivascular and subcapsular collagen,
and NCAE preceded MMP-1 expression in neutrophils,
an occurrence that appeared to contribute to their
liver evasion. Thus, the murine fetal liver during
ontogenesis shows two different phases: one immature
and mainly endodermic (<14 dpc) and the other more
developed (endodermic-mesenchymal; >15 dpc) with the
maturation of hepatocytes, a better definition of trabecular
pattern, and an increase in the connective tissue in the capsule,
portal spaces, and liver parenchyma. The decrease of hepatic
hematopoiesis (migration) coincides with hepatic maturation.