Identification of the growth-promoting PKD/YAP axis as a novel target for the statins in intestinal epithelial cells.

上皮细胞的增殖、谱系特异性分化、迁移和死亡 肠粘膜细胞的增殖是一个严格调节的过程， 调节肽、神经递质、生物活性脂质和分化信号。许多这些 刺激通过七螺旋G蛋白偶联受体（GPCR）起作用。尽管他们 最重要的是，所涉及的细胞内信号转导机制仍然存在， 不完全理解。蛋白激酶D（PKD）是GPCR信号传导的关键节点 从而了解PKD在肠上皮细胞中的调节和功能 具有强烈的兴趣和潜在的影响。高度保守的Hippo/雅普/TAZ途径是 作为器官大小，组织再生， 致癌作用和GPCR信号传导。根据我们的初步结果，我们发现了一种新的 PKD和雅普之间的串扰在促进肠上皮细胞 增殖进一步的初步结果表明，FDA批准的他汀类药物具有强效作用 GPCR/PKD诱导的YAP诱导的肠内转录和DNA合成的抑制剂 上皮细胞他汀类药物还在体外消除肠样结构的形成，并阻止肠样结构的再生。 损伤后结肠黏膜。因此，我们的中心假设是：1）PKD/雅普/TAZ 信号传导在促进肠上皮细胞增殖中起着至关重要的作用， 祖细胞/干细胞和2）他汀类药物通过靶向肠上皮细胞增殖抑制肠上皮细胞增殖。 PKD/雅普/TAZ轴。一个重要的翻译推论是， 他汀类药物为结肠直肠癌的化学预防提供了一种新的策略 和IBD相关CRC通过抑制促生长PKD/雅普/TAZ轴。三 具体目标1：确定脂质- 降低他汀类药物通过PKD/雅普轴靶向肠道内的信号传导 上皮细胞;特定目的2：表征他汀类药物诱导的对上皮细胞的抑制作用， PKD/雅普/TEAD通路对体内肠上皮细胞增殖的影响，包括 体外3D培养中的祖细胞和Lgr 5+肠干细胞和肠样细胞;特异性目的 3：确定他汀敏感性PKD/雅普/TEAD轴在肠上皮细胞中的作用 再生和致癌作用。我们预计，这一提案的结果将提供一个 实施针对PKD/雅普的创新治疗干预的有力依据 在消化系统增殖性疾病中的信号传导轴，包括CRC和IBD， 在美国退伍军人以及美国广大人群中的相关CRC。

The sequential proliferation, lineage-specific differentiation, migration and death of the epithelial cells of the intestinal mucosa is a tightly regulated process modulated by a broad range of regulatory peptides, neurotransmitters, bioactive lipids and differentiation signals. Many of these stimuli act through heptahelical G protein-coupled receptors (GPCRs). Despite their fundamental importance, the intracellular signal transduction mechanisms involved remain incompletely understood. Protein kinase D (PKD) is emerging as a key node in GPCR signaling and consequently the understanding of PKD regulation and function in intestinal epithelial cells is of intense interest and potential impact. The highly conserved Hippo/YAP/TAZ pathway is also attracting strong attention as a key regulator of organ-size, tissue regeneration, carcinogenesis and GPCR signaling. Based on our preliminary results, we identified a novel crosstalk between PKD and YAP that plays a critical role in promoting intestinal epithelial cell proliferation. Further preliminary results demonstrate that FDA-approved statins act as potent inhibitors of GPCR/PKD-induced YAP-induced transcription and DNA synthesis in intestinal epithelial cells. Statins also abrogated enteroid formation in vitro and prevented regeneration of colon mucosa after injury. Consequently, our central hypotheses are: 1) PKD/YAP/TAZ signaling plays a vital role in promoting the proliferation of intestinal epithelial cells including progenitor/stem cells and 2) statins restrain intestinal epithelial cell proliferation by targeting the PKD/YAP/TAZ axis in these cells. An important translational corollary is that the widely used drugs of the statin family provide a novel strategy in the chemoprevention of colorectal (CRC) and IBD-related CRC through inhibition of the growth-promoting PKD/YAP/TAZ axis. Three Specific Aims are proposed: SPECIFIC AIM 1: Identify the mechanism(s) by which the lipid- lowering drugs of the statin family target signaling through the PKD/YAP axis in intestinal epithelial cells; SPECIFIC AIM 2: Characterize the impact of statin-induced inhibition of the PKD/YAP/TEAD pathway on the proliferation of intestinal epithelial cells in vivo, including progenitor and Lgr5+ intestinal stem cells and enteroids in 3 D cultures in vitro; SPECIFIC AIM 3: Determine the role of the statin-sensitive PKD/YAP/TEAD axis in intestinal epithelial cell regeneration and carcinogenesis. We anticipate that the outcome of this proposal will provide a robust rationale for implementing innovative therapeutic interventions targeting the PKD/YAP signaling axis in proliferative diseases of the digestive system, including CRC and IBD- associated CRC in US veterans as well as in the US population at large.