TY - JOUR
T1 - Cardiac-specific abrogation of NF-κB activation in mice by transdominant expression of a mutant IκBα
AU - Dawn, Buddhadeb
AU - Xuan, Yu Ting
AU - Marian, Moazez
AU - Flaherty, Michael P.
AU - Murphree, Sidney S.
AU - Smith, Traci L.
AU - Bolli, Roberto
AU - Jones, Keith W.
N1 - Funding Information:
This study was supported in part by NIH grant R01 HL63034 and AHA grant 9930195N (W.K.J); by NIH grants R01 HL-43151 and HL-55757 (R.B.); by Kentucky AHA Fellowships KY-96-F-24 and 9804556 (B.D.), and by the Jewish Hospital Research Foundation, Louisville, KY. We gratefully acknowledge Dr John Hiscott at the Department of Biochemistry, McGill University, Montreal, Canada, for the kind donation of the cDNA.
PY - 2001
Y1 - 2001
N2 - Nuclear factor-kappaB (NF-κB) is a pleiotropic oxidant-sensitive transcription factor that is present in the cytosol in an inactive form complexed to an inhibitory kappaB (IκB) monomer. Various stimuli, including ischemia, hypoxia, free radicals, cytokines, and lipopolysaccharide (LPS), activate NF-κB by inducing phosphorylation of IκB. Phosphorylation of serine residues at positions 32 and 36 is critical for ubiquitination and degradation of IκBα with consequent migration of NF-κB to the nucleus. Although NF-κB is thought to contribute to numerous pathophysiologic processes, definitive assessment of its role has been hindered by the inability to achieve specific inhibition in vivo. Pharmacologic inhibitors of NF-κB are available, but their utility for in vivo studies is limited by their relative lack of specificity. Targeted ablation of genes encoding NF-κB subunits has not been productive in this regard because of fetal lethality in the case of p65 and functional redundancy in the Rel family of proteins. To overcome these limitations, we have created a viable transgenic mouse that expresses a phosphorylation-resistant mutant of IκBα (IκBαS36A,S36A) under the direction of a cardiac-specific promoter. Several transgenic lines were obtained with copy numbers ranging from one to seven. The mice exhibit normal cardiac morphology and histology. Total myocardial IκBα protein level is elevated 3.5- to 6.5-fold with a concomitant 50-60% decrease in the level of IκBβ. Importantly, expression of IκBS32A,S36A results in complete abrogation of myocardial NF-κB activation in response to tumor necrosis factor-α (TNF-α) and LPS stimulation. Thus, novel transgenic mice have been created that make it possible to achieve cardiac-specific and selective inhibition of NF-κB in vivo. These transgenic mice should be useful in studies of various cardiac pathophysiological phenomena that involve NF-κB activation, including ischemic preconditioning, heart failure, septic shock, acute coronary syndromes, cardiac allograft rejection, and apoptosis.
AB - Nuclear factor-kappaB (NF-κB) is a pleiotropic oxidant-sensitive transcription factor that is present in the cytosol in an inactive form complexed to an inhibitory kappaB (IκB) monomer. Various stimuli, including ischemia, hypoxia, free radicals, cytokines, and lipopolysaccharide (LPS), activate NF-κB by inducing phosphorylation of IκB. Phosphorylation of serine residues at positions 32 and 36 is critical for ubiquitination and degradation of IκBα with consequent migration of NF-κB to the nucleus. Although NF-κB is thought to contribute to numerous pathophysiologic processes, definitive assessment of its role has been hindered by the inability to achieve specific inhibition in vivo. Pharmacologic inhibitors of NF-κB are available, but their utility for in vivo studies is limited by their relative lack of specificity. Targeted ablation of genes encoding NF-κB subunits has not been productive in this regard because of fetal lethality in the case of p65 and functional redundancy in the Rel family of proteins. To overcome these limitations, we have created a viable transgenic mouse that expresses a phosphorylation-resistant mutant of IκBα (IκBαS36A,S36A) under the direction of a cardiac-specific promoter. Several transgenic lines were obtained with copy numbers ranging from one to seven. The mice exhibit normal cardiac morphology and histology. Total myocardial IκBα protein level is elevated 3.5- to 6.5-fold with a concomitant 50-60% decrease in the level of IκBβ. Importantly, expression of IκBS32A,S36A results in complete abrogation of myocardial NF-κB activation in response to tumor necrosis factor-α (TNF-α) and LPS stimulation. Thus, novel transgenic mice have been created that make it possible to achieve cardiac-specific and selective inhibition of NF-κB in vivo. These transgenic mice should be useful in studies of various cardiac pathophysiological phenomena that involve NF-κB activation, including ischemic preconditioning, heart failure, septic shock, acute coronary syndromes, cardiac allograft rejection, and apoptosis.
KW - IκBα
KW - LPS
KW - Myocardium
KW - NF-κB
KW - TNF-α
KW - Transgenic mouse
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U2 - 10.1006/jmcc.2000.1291
DO - 10.1006/jmcc.2000.1291
M3 - Article
C2 - 11133232
AN - SCOPUS:0035142594
SN - 0022-2828
VL - 33
SP - 161
EP - 173
JO - Journal of Molecular and Cellular Cardiology
JF - Journal of Molecular and Cellular Cardiology
IS - 1
ER -