VIP-induced gene expression in colonic smooth muscle cells

VIP诱导结肠平滑肌细胞基因表达

• 批准号: 7122093
• 负责人: SUSHIL K SARNA
• 金额: $ 31.7万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-15 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7122093
• 关键词: biological signal transduction; cAMP response element binding protein; calcium channel; calmodulin dependent protein kinase; clinical research; colon; cyclic AMP; enteric nervous system; gastrointestinal motility /pressure; gene expression; genetic promoter element; genetic regulation; human tissue; laboratory rat; muscle cells; muscle function; neuropeptides; phosphorylation; protein kinase A; smooth muscle; tumor necrosis factor alpha; vasoactive intestinal peptide

DESCRIPTION (provided by applicant): Vasoactive intestinal polypeptide (VIP) and pituitary adenylate cyclase-activating peptide (PACAP) are the inhibitory neurotransmitters in the gut wall. The mechanisms of the non-genomic effects of these neurotransmitters in smooth muscle relaxation have been investigated extensively over the last several decades. The genomic effects of these neurotransmitters on smooth muscle function are not known. VIP and PACAP, on binding to their receptors on smooth muscle cells, activate adenylate cyclase to produce cyclic 3'-5' adenosine monophosphate (cAMP) that mediates smooth muscle relaxation. However, cAMP is also a well known mediator of gene expression through the binding of transcription factor CRE binding protein (CREB) to the cAMP response element (CRE) on the promoters of its target genes. We have obtained substantial preliminary data that suggest an important novel function of the classic neurotransmitters VIP and PACAP to induce gene expression of the pore-forming alpha1C subunit of L-type Ca2+ channels in human colonic circular smooth muscle cells (HCCSMC). Ca2+ influx through these channels is an immediate early step in the signaling cascade for excitation-contraction coupling. Our preliminary data indicate that VIP/PACAP may also be anti-inflammatory neuropeptides that counter the initiation of the signaling cascade that activates the transcription factor NF-KB resulting in the suppression of cell contractility during inflammation. Based on these preliminary data our specific aims are to investigate: 1) VIP/PACAP-induced enhancement of alpha1C gene expression through cAMP/PKA signaling pathway in HCCSMC. 2) The cis- and trans-regulation of human ?1C promoter by VIP/PACAP-induced phosphorylation of the transcription factor CREB. 3) The interactions between cAMP/PKA, MAPK, PKC and CaMKII signaling pathways for the induction of alpha1C gene by VIP and PACAP. 4) The molecular and epigenetic mechanisms of the rnyo-protective role of VIP/PACAP in HCCSMC. This grant proposal presents a novel direction of research in the genomic regulation of smooth muscle function by two prominent and abundant neurotransmitters (VIP and PACAP) of the enteric inhibitory motor neurons. The findings will provide genomic and molecular insights into regulation of the expression of L-type calcium channels that play a critical role in excitation-contraction coupling in the normal state and during inflammation.

性状（由申请人提供）：血管活性肠肽（VIP）和垂体腺苷酸环化酶激活肽（PACAP）是肠壁中的抑制性神经递质。在过去的几十年中，这些神经递质在平滑肌松弛中的非基因组效应的机制已经被广泛研究。这些神经递质对平滑肌功能的基因组效应尚不清楚。VIP和PACAP与平滑肌细胞上的受体结合后，激活腺苷酸环化酶，产生环3 '-5'腺苷一磷酸（cAMP），介导平滑肌松弛。然而，cAMP也是一种众所周知的基因表达介质，通过转录因子CRE结合蛋白（CREB）与其靶基因启动子上的cAMP反应元件（CRE）结合。我们已经获得了大量的初步数据，表明经典的神经递质VIP和PACAP诱导人结肠环形平滑肌细胞（HCCSMC）L型钙通道的成孔α 1C亚基的基因表达的一个重要的新功能。通过这些通道的Ca 2+内流是兴奋-收缩偶联的信号级联中的立即早期步骤。我们的初步数据表明VIP/PACAP也可能是抗炎神经肽，其对抗激活转录因子NF-κ B的信号级联的启动，导致炎症期间细胞收缩性的抑制。基于这些初步数据，我们的具体目标是研究：1）VIP/PACAP通过cAMP/PKA信号通路诱导HCCSMC α 1C基因表达增强。2)人类的顺式和反式调节？1C启动子通过VIP/PACAP诱导的转录因子CREB磷酸化。3)cAMP/PKA、MAPK、PKC和CaMKII信号通路在VIP和PACAP诱导alpha 1C基因表达中的相互作用4)VIP/PACAP对HCC SMC的免疫保护作用的分子和表观遗传学机制这项拨款提案提出了一个新的研究方向，在基因组调控平滑肌功能的两个突出的和丰富的神经递质（VIP和PACAP）的肠抑制运动神经元。这些发现将为调节L型钙通道的表达提供基因组和分子见解，L型钙通道在正常状态和炎症期间的兴奋-收缩偶联中发挥关键作用。