Fibrosis leads to organ dysfunction and is characterized by an excessive production of extracellular matrix (ECM) components, namely type I and III collagens. Although activated hepatic stellate cell (HSC) remains the principal cell type responsible for liver fibrosis, other liver cell type of fibroblast lineage derived from portal and centrolobular veins also have fibrogenic potential. The overall hypothesis is that liver fibrosis can be treated by systemic administration of a1(I) collagen gene promoter specific triplex forming oligonucleotides (TFOs) conjugated with mannose 6-phosphate-bovine serum albumin (M6P-BSA) via a disulfide bond. In preliminary studies, antiparallel phosphorothioate polypurine TFOs specific for CI region formed triplexes, inhibited transcription of a1(I) collagen promoter and improved rat liver fibrosis. TFOs rapidly distributed throughout the body after systemic administration, with the highest accumulation in the liver. TFO accumulation in the liver was decreased when injected into liver fibrotic rats. Kupffer, sinusoidal endothelial and hepatic stellate cells accounted for approximately 70% of the liver uptake, and the remaining 30% in the hepatocytes. Bioconjugation with M6P-BSA significantly enhanced the cellular uptake of the TFOs by HSC-T6 cells in vitro, leading to enhanced inhibition of type a1(I) collagen transcription. TFO delivery to the liver and to the HSCs was significantly increased when M6P-BSA-TFO was injected intravenously into fibrotic rats.
Our specific aims are to determine whether i) conjugation of targeting ligands to TFOs affect triplex formation;ii) TFOs inhibit fibrosis by inhibiting transcription of a1(I) collagen and/or blocking inflammation and activation of liver fibrogenic cells;and iii) M6P-BSA-TFO can be delivered efficiently to liver fibrogenic cells and prevent fibrosis. The significance of this research is that the proposed targeted TFO delivery to liver fibrogenic cells will inhibit disproportionate accumulation of a1(I) collagen, which is essential for the treatment of liver fibrosis. The data will also be beneficial to successful treatment of other organ fibrosis.

Agency
National Institute of Health (NIH)
Institute
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Type
Research Project (R01)
Project #
5R01EB003922-04
Application #
7747940
Study Section
Gene and Drug Delivery Systems Study Section (GDD)
Program Officer
Zullo, Steven J
Project Start
2007-03-01
Project End
2011-12-31
Budget Start
2010-01-01
Budget End
2011-12-31
Support Year
4
Fiscal Year
2010
Total Cost
$223,098
Indirect Cost
Name
University of Tennessee Health Science Center
Department
Pharmacology
Type
Schools of Pharmacy
DUNS #
941884009
City
Memphis
State
TN
Country
United States
Zip Code
38163
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Pratap, Akshay; Panakanti, Ravikiran; Yang, Ningning et al. (2011) Cyclopamine attenuates acute warm ischemia reperfusion injury in cholestatic rat liver: hope for marginal livers. Mol Pharm 8:958-68
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Panakanti, Ravikiran; Pratap, Akshay; Yang, Ningning et al. (2010) Triplex forming oligonucleotides against type ?1(I) collagen attenuates liver fibrosis induced by bile duct ligation. Biochem Pharmacol 80:1718-26
Zhu, Lin; Mahato, Ram I (2010) Lipid and polymeric carrier-mediated nucleic acid delivery. Expert Opin Drug Deliv 7:1209-26
Zhu, Lin; Mahato, Ram I (2010) Targeted delivery of siRNA to hepatocytes and hepatic stellate cells by bioconjugation. Bioconjug Chem 21:2119-27
Pratap, Akshay; Panakanti, Ravikiran; Yang, Ningning et al. (2010) Inhibition of endogenous hedgehog signaling protects against acute liver injury after ischemia reperfusion. Pharm Res 27:2492-504
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Yang, Ningning; Ye, Zhaoyang; Li, Feng et al. (2009) HPMA polymer-based site-specific delivery of oligonucleotides to hepatic stellate cells. Bioconjug Chem 20:213-21

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