A Novel Role of VIP in Colonic Motility Function: Induction of Excitation-Transcription Coupling in Smooth Muscle Cells

Xuan-Zheng Shi, Barun Choudhury, Pankaj J. Pasricha, Sushil K. Sarna

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Background & Aims: Vasoactive intestinal polypeptide (VIP) relaxes smooth muscle by generation of cAMP and activation of protein kinase A (PKA). However, PKA activation also phosphorylates the transcription factor CREB. The aim of this study was to investigate whether the phosphorylation of CREB induces gene expression of the pore-forming α1C subunit of Cav1.2 channels (L-type calcium channels), whose promoter has 2 binding sites for CREB. Methods: The experiments were performed on primary cultures of human colonic circular smooth muscle cells and freshly obtained human and rat colonic circular muscle strips. Results: The incubation of human colonic circular smooth muscle cells or muscle strips with VIP for 24 hours enhanced the expression of α1C protein and mRNA as well as the contractile response to acetylcholine and KCl. On the contrary, incubation of the muscle strips with VIP antagonist for 24 hours suppressed cell contractility. The incubation of the cells with VIP caused sustained generation of cAMP for 24 hours, but PKA activation and CREB phosphorylation were transient. The inhibition of PKA by H-89 or silencing of CREB gene with targeted RNAi blocked the transcription of α1C. Progressive 5′ deletions of hα1C1b promoter and site-directed mutations of the 2 CREB binding cis-elements indicated that most of α1C transcription was mediated by the 5′ cAMP response element. Conclusions: The excitation-transcription coupling stimulated by VIP induces expression of the Cav1.2 channels. The influx of calcium through these channels is a critical step in excitation-contraction coupling in smooth muscle cells.

Original languageEnglish (US)
Pages (from-to)1388-1400
Number of pages13
JournalGastroenterology
Volume132
Issue number4
DOIs
StatePublished - Apr 2007

Fingerprint

Vasoactive Intestinal Peptide
Smooth Muscle Myocytes
Cyclic AMP-Dependent Protein Kinases
Muscles
Phosphorylation
Excitation Contraction Coupling
L-Type Calcium Channels
Response Elements
Gene Silencing
Calcium Channels
RNA Interference
Acetylcholine
Smooth Muscle
Transcription Factors
Binding Sites
Gene Expression
Messenger RNA
Mutation
Proteins

ASJC Scopus subject areas

  • Gastroenterology

Cite this

A Novel Role of VIP in Colonic Motility Function : Induction of Excitation-Transcription Coupling in Smooth Muscle Cells. / Shi, Xuan-Zheng; Choudhury, Barun; Pasricha, Pankaj J.; Sarna, Sushil K.

In: Gastroenterology, Vol. 132, No. 4, 04.2007, p. 1388-1400.

Research output: Contribution to journalArticle

Shi, Xuan-Zheng ; Choudhury, Barun ; Pasricha, Pankaj J. ; Sarna, Sushil K. / A Novel Role of VIP in Colonic Motility Function : Induction of Excitation-Transcription Coupling in Smooth Muscle Cells. In: Gastroenterology. 2007 ; Vol. 132, No. 4. pp. 1388-1400.
@article{7fd45d52147b4b47bf5c10c986f49da4,
title = "A Novel Role of VIP in Colonic Motility Function: Induction of Excitation-Transcription Coupling in Smooth Muscle Cells",
abstract = "Background & Aims: Vasoactive intestinal polypeptide (VIP) relaxes smooth muscle by generation of cAMP and activation of protein kinase A (PKA). However, PKA activation also phosphorylates the transcription factor CREB. The aim of this study was to investigate whether the phosphorylation of CREB induces gene expression of the pore-forming α1C subunit of Cav1.2 channels (L-type calcium channels), whose promoter has 2 binding sites for CREB. Methods: The experiments were performed on primary cultures of human colonic circular smooth muscle cells and freshly obtained human and rat colonic circular muscle strips. Results: The incubation of human colonic circular smooth muscle cells or muscle strips with VIP for 24 hours enhanced the expression of α1C protein and mRNA as well as the contractile response to acetylcholine and KCl. On the contrary, incubation of the muscle strips with VIP antagonist for 24 hours suppressed cell contractility. The incubation of the cells with VIP caused sustained generation of cAMP for 24 hours, but PKA activation and CREB phosphorylation were transient. The inhibition of PKA by H-89 or silencing of CREB gene with targeted RNAi blocked the transcription of α1C. Progressive 5′ deletions of hα1C1b promoter and site-directed mutations of the 2 CREB binding cis-elements indicated that most of α1C transcription was mediated by the 5′ cAMP response element. Conclusions: The excitation-transcription coupling stimulated by VIP induces expression of the Cav1.2 channels. The influx of calcium through these channels is a critical step in excitation-contraction coupling in smooth muscle cells.",
author = "Xuan-Zheng Shi and Barun Choudhury and Pasricha, {Pankaj J.} and Sarna, {Sushil K.}",
year = "2007",
month = "4",
doi = "10.1053/j.gastro.2007.02.016",
language = "English (US)",
volume = "132",
pages = "1388--1400",
journal = "Gastroenterology",
issn = "0016-5085",
publisher = "W.B. Saunders Ltd",
number = "4",

}

TY - JOUR

T1 - A Novel Role of VIP in Colonic Motility Function

T2 - Induction of Excitation-Transcription Coupling in Smooth Muscle Cells

AU - Shi, Xuan-Zheng

AU - Choudhury, Barun

AU - Pasricha, Pankaj J.

AU - Sarna, Sushil K.

PY - 2007/4

Y1 - 2007/4

N2 - Background & Aims: Vasoactive intestinal polypeptide (VIP) relaxes smooth muscle by generation of cAMP and activation of protein kinase A (PKA). However, PKA activation also phosphorylates the transcription factor CREB. The aim of this study was to investigate whether the phosphorylation of CREB induces gene expression of the pore-forming α1C subunit of Cav1.2 channels (L-type calcium channels), whose promoter has 2 binding sites for CREB. Methods: The experiments were performed on primary cultures of human colonic circular smooth muscle cells and freshly obtained human and rat colonic circular muscle strips. Results: The incubation of human colonic circular smooth muscle cells or muscle strips with VIP for 24 hours enhanced the expression of α1C protein and mRNA as well as the contractile response to acetylcholine and KCl. On the contrary, incubation of the muscle strips with VIP antagonist for 24 hours suppressed cell contractility. The incubation of the cells with VIP caused sustained generation of cAMP for 24 hours, but PKA activation and CREB phosphorylation were transient. The inhibition of PKA by H-89 or silencing of CREB gene with targeted RNAi blocked the transcription of α1C. Progressive 5′ deletions of hα1C1b promoter and site-directed mutations of the 2 CREB binding cis-elements indicated that most of α1C transcription was mediated by the 5′ cAMP response element. Conclusions: The excitation-transcription coupling stimulated by VIP induces expression of the Cav1.2 channels. The influx of calcium through these channels is a critical step in excitation-contraction coupling in smooth muscle cells.

AB - Background & Aims: Vasoactive intestinal polypeptide (VIP) relaxes smooth muscle by generation of cAMP and activation of protein kinase A (PKA). However, PKA activation also phosphorylates the transcription factor CREB. The aim of this study was to investigate whether the phosphorylation of CREB induces gene expression of the pore-forming α1C subunit of Cav1.2 channels (L-type calcium channels), whose promoter has 2 binding sites for CREB. Methods: The experiments were performed on primary cultures of human colonic circular smooth muscle cells and freshly obtained human and rat colonic circular muscle strips. Results: The incubation of human colonic circular smooth muscle cells or muscle strips with VIP for 24 hours enhanced the expression of α1C protein and mRNA as well as the contractile response to acetylcholine and KCl. On the contrary, incubation of the muscle strips with VIP antagonist for 24 hours suppressed cell contractility. The incubation of the cells with VIP caused sustained generation of cAMP for 24 hours, but PKA activation and CREB phosphorylation were transient. The inhibition of PKA by H-89 or silencing of CREB gene with targeted RNAi blocked the transcription of α1C. Progressive 5′ deletions of hα1C1b promoter and site-directed mutations of the 2 CREB binding cis-elements indicated that most of α1C transcription was mediated by the 5′ cAMP response element. Conclusions: The excitation-transcription coupling stimulated by VIP induces expression of the Cav1.2 channels. The influx of calcium through these channels is a critical step in excitation-contraction coupling in smooth muscle cells.

UR - http://www.scopus.com/inward/record.url?scp=34247257789&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34247257789&partnerID=8YFLogxK

U2 - 10.1053/j.gastro.2007.02.016

DO - 10.1053/j.gastro.2007.02.016

M3 - Article

C2 - 17408637

AN - SCOPUS:34247257789

VL - 132

SP - 1388

EP - 1400

JO - Gastroenterology

JF - Gastroenterology

SN - 0016-5085

IS - 4

ER -