VIP-induced gene expression in colonic smooth muscle

VIP诱导的结肠平滑肌基因表达

• 批准号: 6964304
• 负责人: SUSHIL K SARNA
• 金额: $ 32.47万
• 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/6964304
• 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（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）是肠壁中的抑制性神经递质。在过去的几十年里，这些神经递质在平滑肌松弛中的非基因组效应的机制已被广泛研究。这些神经递质对平滑肌功能的基因组影响尚不清楚。 VIP 和 PACAP 在与平滑肌细胞上的受体结合后，激活腺苷酸环化酶，产生介导平滑肌松弛的环状 3'-5' 腺苷单磷酸 (cAMP)。然而，cAMP 也是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。我们已经获得大量初步数据，表明经典神经递质 VIP 和 PACAP 具有诱导人结肠圆形平滑肌细胞 (HCCSMC) 中 L 型 Ca2+ 通道成孔 α1C 亚基基因表达的重要新功能。 Ca2+ 通过这些通道的流入是兴奋-收缩耦合信号级联中的早期步骤。我们的初步数据表明，VIP/PACAP 也可能是抗炎神经肽，可以对抗信号级联的启动，从而激活转录因子 NF-KB，从而抑制炎症期间的细胞收缩性。基于这些初步数据，我们的具体目标是研究：1) VIP/PACAP 在 HCCSMC 中通过 cAMP/PKA 信号通路诱导 alpha1C 基因表达增强。 2)VIP/PACAP诱导的转录因子CREB磷酸化对人α1C启动子的顺式和反式调节。 3) cAMP/PKA、MAPK、PKC 和 CaMKII 信号通路之间的相互作用，通过 VIP 和 PACAP 诱导 alpha1C 基因。 4) VIP/PACAP在HCCSMC中的神经保护作用的分子和表观遗传机制。该资助提案提出了肠抑制运动神经元的两种重要且丰富的神经递质（VIP 和 PACAP）对平滑肌功能的基因组调节的新研究方向。这些发现将为 L 型钙通道的表达调节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-收缩耦合中发挥关键作用。