Apoptosis and Its Suppression in Hepatocytes Culture |
| |
Authors: | Nyaradzo T Mukwena Mohamed Al-Rubeai |
| |
Institution: | (1) Department of Chemical Engineering, University of Birmingham, Birmingham, B15 2TT, UK;(2) Department of Chemical and Biochemical Engineering, and Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland |
| |
Abstract: | In order to achieve the goal of developing extracorporeal liver support devices, it is necessary to optimise bioprocess environment
such that viability and function are maximised. Optimising culture medium composition and controlling the constitution of
the cellular microenvironment within the bioreactor have for many years been considered vital to achieving these aims. Coupled
to this is the need to understand apoptosis, the prime suspect in the demise of animal cultures, including those of hepatocytes.
Results presented here show that absent nutrients including glucose and amino acids play a substantial part in the induction
of apoptosis. The use of chemical apoptosis inhibitors was utilised to investigate key components of hepatic apoptosis where
caspases, predominantly caspase 8, were implicated in staurosporine (STS)-induced HepZ apoptosis. Caspase 9 and 3 activation
although recorded was of less significance. Interestingly, these results were not consistent with those of mitochondrial membrane
depolarisation where inhibition of caspase activation appeared to drive depolarisation. Inhibition of mitochondrial permeability
transition and use of anti-oxidants was unsuccessful in reducing apoptosis, caspase activation and mitochondrial membrane
depolarisation. In further studies, the anti-apoptotic gene bcl-2 was over-expressed in HepZ, resulting in a cell line that was more robust and resistant to death induced by glucose and cystine
deprivation and treatment with STS. Bcl-2 did not however show significant cytoprotectivity where apoptosis was stimulated
by deprivation of glutamine and serum. Overall, results indicated that although apoptosis can be curbed by use of chemical
inhibitors and genetic manipulation, their success is dependent on apoptotic stimuli. |
| |
Keywords: | Apoptosis Bcl-2 Caspases Hepatocytes HepZ Mitochondria membrane potential Staurosporine |
本文献已被 SpringerLink 等数据库收录! |
|