Naslov
Characterization of the COl2.3deltaTK mouse

Autori
Višnjić, Dora ; Kalajzić, Ivo ; Gronowicz, Gloria ; Clark, H Steve ; Rowe, W David

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

Izvornik
Bone 23:5 (Suppl), S181, 1134, 1998 / - , 1998

Skup
ASBMR Annual Meeting

Mjesto i datum
San Francisco (CA), Sjedinjene Američke Države, 01.12.1998. - 06.12.1998

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
transgenic mice; HSV-TK; osteoblast

Sažetak
We have developed a transgenic mouse model of conditional ablation of bone cells as a recipient to develop methods of bone cell transplantation. It is designed to give the non-transgenic donor cells a competitive advantage for repopulating the bone which may be important for engraftment of cells with osteogenic potential. To allow selective ablation of bone cells upon the treatment with ganciclovir (GCV), a truncated version of herpes simplex virus (HSV) thymidine kinase (deltaTK) gene was placed under the control of the 2.3kb rat COL1A1 promoter that was previously shown to direct expression of the CATreporter gene to bone cells in vivo. delta TK, a generous gift from Dr. D. Klatzmann ((Salomon et al Mol Cell Biol 15:5322-5328, 1995) was used in order to avoid a significant male sterility problem we experienced in male founders carrying the full-length gene and autonoumously expressing high levels of 1.2 and 0.9 kB transcipts in testes. This phenomenon is ascribed to the presence of a cryptic promoter in the coding sequences of TK. The first male founder carrying the 2.3deltaTK transgene was feertile and transmitted the transgene at the expected frequency. RNA analysis of positive second generation animals shown high levels of deltaTK transcripts in long bones, calvaria and tail, and low, but detectable levels in brain, the presence of shorter (0.9kB) transcript in testes, and no detectable expression in liver and lung. A short 7-day treatment of 6-weeks old animals with 1.5 mg/day of GCV as well as 18-days treatment with 0, 5 mg/day resulted in complete disappearance of deltaTK, osteocalcin and collagen transcripts in bones, and profoundly inhibits growth of marrow stromal fibroblasts, flushed out from the long bones of treated animals. Histological analysis of tibias revealed the absence of osteoblasts lining endosteal and trabecular surfaces, empty lacunae within bone and marked loss of bone marrow cellularity. No sign of toxicity was observed in nontransgenic animals treated with the same dose of GCV. Further dose-titration and in vitro experiments are under the way. The transgene is going to be introduced into C57BL/6 as well as SCID/beige background to initiate transplantation experiments.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

POVEZANOST RADA