Naslov
Receptor- Mediated Targeting of Toxin Results in Hepatotoxicity Without Collateral Damage in Rats

Autori
Volarević, Martina ; Smolić, Robert ; Wu, Catherine H ; Andorfer, John H ; Wu, George Y.

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

Izvornik
The Association of American Physicians and the American Society for Clinical Investigation 2007 Joint Meeting / - , 2007, Xx-xx

Skup
The Association of American Physicians and the American Society for Clinical Investigation 2007 Joint Meeting

Mjesto i datum
Chicago (IL), Sjedinjene Američke Države, 13.04.2007. - 15.04.2007

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
rat model ; chimeric human liver ; Receptor-Mediated Targeting

Sažetak
We recently developed a rat model with a chimeric human liver. However, that model contained relatively few human hepatocytes. To increase the ratio of human cells, a selection strategy was devised to eliminate host hepatocytes by transfection of a neomycin resistance gene into human hepatocytes and use of G418 for selection.However, G418 has extrahepatic toxicity in mammals. Aim: Our objective was to target G418 specifically to liver via asialoglycoprotein receptors (AsGR). Methods: A novel G418 conjugate was created by chemically coupling G418 to a galactose-terminal asialoglycoprotein, asialoorosomucoid (AsOR). Groups of normal rats were injected IV with radiolabeled conjugate and organ distribution determined. Groups of 7 days old SD rats (n=4-7) were also injected with AsOR-G418 (100 mg/kg, iv), free G418, AsOR or PBS. Serum samples were collected for alanine aminotransferase (ALT), an assay for liver damage ; and creatinine release, an assay for kidney toxicity. Six days after treatment, animals were sacrificed and liver and kidneys collected for total RNA isolation, fixed and stained with hematoxylin/eosin and periodic acid-Schiff(PAS). Results: Fifteen min after IV injection, 82% of labeled conjugate was found in liver. This uptake was the same as for AsOR alone suggesting that G418 conjugate recognition in animals was similar to AsOR alone. In rats treated with 100mg/kg free G418, the survival rate was 50% at 48 h, and 0% at 72 h. In contrast, in groups that received identical G418 as a conjugate, 100mg/kg IV, the 48 h survival rate was 100%, the same as in AsOR and PBS controls. However, ALT levels in conjugate-treated rats doubled to a mean of 224+/- 3 U/L, by 48 h, compared to no change in AsOR, G418 and PBS treated groups. Creatinine levels in conjugate-treated rats were the same as AsOR, and PBS control groups, while in the G418-treated group, levels increased to 3.2 mg/dl by 48 h. In kidney sections of G418-treated rats, PAS- positive brush border disappeared, not found in conjugate-treated group. In contrast, liver sections of conjugate-treated rats showed mild liver injury, not present in AsOR, G418 and PBS control treated groups. Conclusion: G418 in the form of a conjugate retains toxicity that can be targeted specifically to liver cells through AsGR highly expressed on those cells. Conjugate-mediated hepatotoxicity did not result in damage to kidney or other tissues. Targeted selection may be useful in the manipulation of populations of various cell types in laboratory animals.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

POVEZANOST RADA