TY - JOUR

T1 - Expression of endothelin type B receptors (EDNRB) on smooth muscle cells is controlled by MKL2, ternary complex factors, and actin dynamics

AU - Krawczyk, Katarzyna K.

AU - Skovsted, Gry Freja

AU - Perisic, Ljubica

AU - Dreier, Rasmus

AU - Berg, Jais Oliver

AU - Hedin, Ulf

AU - Rippe, Catarina

AU - Swärd, Karl

PY - 2018

Y1 - 2018

N2 - The endothelin type B receptor (ETB or EDNRB) is highly plastic and is upregulated in smooth muscle cells (SMCs) by arterial injury and following organ culture in vitro. We hypothesized that this transcriptional plasticity may arise, in part, because EDNRB is controlled by a balance of transcriptional inputs from myocardin-related transcription factors (MRTFs) and ternary complex factors (TCFs). We found significant positive correlations between the TCFs ELK3 and FLI1 versus EDNRB in human arteries. The MRTF MKL2 also correlated with EDNRB. Overexpression of ELK3, FLI1, and MKL2 in human coronary artery SMCs promoted expression of EDNRB, and the effect of MKL2 was antagonized by myocardin (MYOCD), which also correlated negatively with EDNRB at the tissue level. Silencing of MKL2 reduced basal EDNRB expression, but depolymerization of actin using latrun-culin B (LatB) or overexpression of constitutively active cofilin, as well as treatment with the Rho-associated kinase (ROCK) inhibitor Y27632, increased EDNRB in a MEK/ERK-dependent fashion. Tran-script-specific primers indicated that the second EDNRB transcript (EDNRB_2) was targeted, but this promoter was largely unresponsive to LatB and was inhibited rather than stimulated by MKL2 and FLI1, suggesting distant control elements or an indirect effect. LatB also reduced expression of endothelin-1, but supplementation experiments argued that this was not the cause of EDNRB induction. EDNRB finally changed in parallel with ELK3 and FLI1 in rat and human carotid artery lesions. These studies implicate the actin cytoskeleton and ELK3, FLI1, and MKL2 in the transcriptional control of EDNRB and increase our understanding of the plasticity of this receptor.

AB - The endothelin type B receptor (ETB or EDNRB) is highly plastic and is upregulated in smooth muscle cells (SMCs) by arterial injury and following organ culture in vitro. We hypothesized that this transcriptional plasticity may arise, in part, because EDNRB is controlled by a balance of transcriptional inputs from myocardin-related transcription factors (MRTFs) and ternary complex factors (TCFs). We found significant positive correlations between the TCFs ELK3 and FLI1 versus EDNRB in human arteries. The MRTF MKL2 also correlated with EDNRB. Overexpression of ELK3, FLI1, and MKL2 in human coronary artery SMCs promoted expression of EDNRB, and the effect of MKL2 was antagonized by myocardin (MYOCD), which also correlated negatively with EDNRB at the tissue level. Silencing of MKL2 reduced basal EDNRB expression, but depolymerization of actin using latrun-culin B (LatB) or overexpression of constitutively active cofilin, as well as treatment with the Rho-associated kinase (ROCK) inhibitor Y27632, increased EDNRB in a MEK/ERK-dependent fashion. Tran-script-specific primers indicated that the second EDNRB transcript (EDNRB_2) was targeted, but this promoter was largely unresponsive to LatB and was inhibited rather than stimulated by MKL2 and FLI1, suggesting distant control elements or an indirect effect. LatB also reduced expression of endothelin-1, but supplementation experiments argued that this was not the cause of EDNRB induction. EDNRB finally changed in parallel with ELK3 and FLI1 in rat and human carotid artery lesions. These studies implicate the actin cytoskeleton and ELK3, FLI1, and MKL2 in the transcriptional control of EDNRB and increase our understanding of the plasticity of this receptor.

KW - EDNRB

KW - Endothelin

KW - MRTFB

KW - Ternary complex factor

U2 - 10.1152/ajpcell.00170.2018

DO - 10.1152/ajpcell.00170.2018

M3 - Journal article

C2 - 30332284

AN - SCOPUS:85060200382

VL - 315

SP - C873-C884

JO - American Journal of Physiology: Cell Physiology

JF - American Journal of Physiology: Cell Physiology

SN - 0363-6143

IS - 6

ER -