Interplay between heme oxygenase-1 and the multifunctional transcription factor yin yang 1 in the inhibition of intimal hyperplasia

K Beck, BJ Wu, J Ni, FS Santiago… - Circulation …, 2010 - Am Heart Assoc
K Beck, BJ Wu, J Ni, FS Santiago, KP Malabanan, C Li, Y Wang, LM Khachigian, R Stocker
Circulation research, 2010Am Heart Assoc
Rationale: Induction of heme oxygenase (HO)-1 protects against experimental
atherosclerotic diseases, and certain pharmacological HO-1 inducers, like probucol, inhibit
the proliferation of vascular smooth muscle cells and, at the same time, promote the growth
of endothelial cells in vivo and in vitro. Objective: Because such cell-specific effects are
reminiscent of the action of the transcription factor Yin Yang (YY) 1, we tested the hypothesis
that there is a functional relationship between HO-1 and YY1. Methods and Results: We …
Rationale:
Induction of heme oxygenase (HO)-1 protects against experimental atherosclerotic diseases, and certain pharmacological HO-1 inducers, like probucol, inhibit the proliferation of vascular smooth muscle cells and, at the same time, promote the growth of endothelial cells in vivo and in vitro.
Objective:
Because such cell-specific effects are reminiscent of the action of the transcription factor Yin Yang (YY)1, we tested the hypothesis that there is a functional relationship between HO-1 and YY1.
Methods and Results:
We report that probucol increases the number of YY1+ cells in rat carotid artery following balloon injury at a time coinciding with increased HO-1 expression. The drug also induces the expression of YY1 mRNA and protein in rat aortic smooth muscle cells (RASMCs) in vitro, as do other known HO-1 inducers (tert-butylhydroquinone and hemin) and overexpression of HO-1 using a human HMOX1 cDNA plasmid. Conversely, overexpression of YY1 induces expression of HO-1 in RASMCs. Induction of YY1 expression is dependent on HO-1 enzyme activity and its reaction product CO, because pharmacological inhibition of heme oxygenase activity or CO scavenging block, whereas exposure of RASMCs to a CO-releasing molecule increases, YY1 expression. Furthermore, RNA interference knockdown of YY1 prevents probucol or adeno–HO-1 from inhibiting RASMC proliferation in vitro and neointimal formation in vivo.
Conclusions:
Our findings show, for the first time, that HO-1 functionally interplays with the multifunctional transcription factor YY1 and that this interplay explains some of the protective activities of HO-1.
Am Heart Assoc