TDK conference 2016

The matriptase-2 is a member of the type II transmembrane serine protease (TTSP) family, which is expressed mainly in the liver and it is considered as a key regulator in iron homeostasis via hepcidin modulation. Nowadays only few drug candidates are capable of affecting hepcidin expression selectively, among them we used two 3-amidinophenylalanine-structure-based matriptase inhibitors (MI). The aim of this investigation was the in vitro pharmacological examination of the potential drug candidates, MI-460 and MI-461 in hepatocytes and in hepatocyte- Kupffer cell co-cultures.

Hepatocyte mono- and hepatocyte-Kupffer cell co-cultures were freshly prepared from 15 kg weighing male pigs of the Hungarian Large White breed. The effect of matriptase inhibitors on cell viability was examined by MTS assay. The extracellular hydrogen peroxide level was measured by Amplex Red method. Subcellular localization of tight junctional proteins, claudin-1 and occludin was investigated by immunfluorescent staining. Further investigations were carried out to trace the correlation of matriptase inhibition with iron homeostasis and inflammatory processes. Porcine specific hepcidin and interleukin-8 (IL-8) ELISA kits were used to determine the hepcidin level and the rate of inflammation of the cell cultures, respectively.

Based on our results, MI-460 and MI-461 were not found to be cytotoxic at the given concentration. The distribution of the tight junctional protein, occludin changed only in the inflammatory co-culture, however, it was confirmed at the same time, that lower membrane positivity of occludin was detected in the untreated co-culture as well. We found that hepcidin level was increased significantly in cell models of both intact and inflamed liver by MI-460 and MI-461. Based on the IL-8 level measurement the MI-461 produced significant antiinflammatory effect in both mono- and co- cultures.

In summary, MI-460 and MI-461 can be considered as safe drug candidates due to their favourable side effect profiles. In addition, MI-460 and MI-461 have effect on regulating iron homeostasis via hepcidin modulation in addition to antiinflammatory effects of MI-461 in vitro.