Naslov
Osteoblasts define the maintenance of hematopoiesis and progenitor lineage commitment in the bone

Autori
Višnjić, Dora ; Kalajzić, Žana ; Katavić, Vedran ; Lorenzo, Joseph ; Rowe, W David ; Aguila, H Leonardo

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
J Bone Miner Res, 16 Suppl 1, S190, F049, 2001 / - , 2001

Skup
ASBMR Annual Meeting 2001

Mjesto i datum
Phoenix (AZ), Sjedinjene Američke Države, 12.10.2001. - 16.10.2001

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
osteoblast; hematopoeza
(osteoblast; hematopoiesis)

Sažetak
We have generated a transgenic mouse model expressing a modified herpes virus thymidine kinase (TK) gene under the control of collagen 2.3 promoter. This construct, Col2.3DTK, permits the expression of TK almost exclusively during early osteoblast lineage development. Upon treatment with Gancyclovir (Gcv), these animals are depleted of osteoblasts and present a drastic bone loss. This phenomenon is concurrent with a loss in bone marrow cellularity. Analysis of hematopoietic components during the early phase of treatment evidenced a loss of B cell, erythroid and osteoclast progenitors. However, cells expressing very early hematopoietic markers, similar to hematopoietic stem cells (HSCs), are still present. Interestingly, these bone marrow progenitors can progress normally towards differentiation in vitro.Active extramedular hematopoiesis is also observed, with a dramatic increase in cells with HSC phenotype in liver and spleen. The kinetics of osteoblast disappearance, loss of medullar hematopoiesis and appearance of progenitors and active hematopoiesis in periphery is concerted. Extramedular hematopoiesis seems to be sufficient to maintain the homeostatic hematological values in periphery. When the Gcv treatment was stopped, the osteoblast lineage is recovered and an exacerbated generation of bone and areas of active hematopoiesis are observed in the bone marrow. Gradually the extramedular hematopoiesis decrease to normal levels. This model provides, the first direct indication on the role of osteoblasts during the hematopoietic process, providing an exceptional tool to study interactions between bone remodeling mechanisms and hematopoiesis.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

POVEZANOST RADA