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.

描述（由申请人提供）：血管活性肠多肽（VIP）和垂体腺苷酸环化酶激活肽（PACAP）是肠壁上的抑制性神经递质。在过去的几十年中，已经广泛研究了这些神经递质在平滑肌松弛中的非基因组作用的机制。这些神经递质对平滑肌功能的基因组作用尚不清楚。 VIP和PACAP与平滑肌细胞上的受体结合时，激活了腺苷酸环化酶，产生环状3'-5'腺苷单磷酸腺苷（CAMP），从而介导平滑肌松弛。然而，CAMP也是通过转录因子CRE结合蛋白（CREB）与其靶基因启动子上CAMP反应元件（CRE）的结合，是众所周知的基因表达介体。我们已经获得了大量的初步数据，这些数据表明了经典神经递质VIP和PACAP的重要新功能，以诱导人类结肠圆形平滑肌细胞（HCCSMC）中L型Ca2+通道的孔形成Alpha1c亚基的基因表达。 CA2+通过这些通道的涌入是信号级联的立即提前步骤，用于激发触发耦合。我们的初步数据表明，VIP/PACAP也可能是抗炎神经肽，它应对激活转录因子NF-KB的信号传导级联反应，从而导致炎症过程中细胞收缩性的抑制。基于这些初步数据，我们的具体目的是研究：1）通过HCCSMC中CAMP/PKA信号通路，VIP/PACAP诱导的α1c基因表达增强。 2）通过VIP/PACAP诱导的转录因子CREB的磷酸化对人的1C启动子的顺式和反式调节。 3）CAMP/PKA，PKA，MAPK，PKC和CAMKII信号通路之间通过VIP和PACAP诱导α1c基因的相互作用。 4）VIP/PACAP在HCCSMC中的RNYO保护作用的分子和表观遗传机制。该赠款提案提出了肠抑制性运动神经元的两个突出和丰富的神经递质（VIP和PACAP）对平滑肌功能的基因组调节的新方向。这些发现将提供基因组和分子见解，以调节L型钙通道的表达，这些钙通道在正常状态和炎症期间在激发诱导偶联中起关键作用。