The Role of Protein Kinase C in Opioid Tolerance

描述（由申请人提供）：文献和我们实验室的证据表明PKC与吗啡耐受机制有关。很明显，它的作用随吗啡耐受程度和持续时间的不同而不同。其在其他阿片类药物耐受性中的作用尚未得到详细研究。PKC与其他神经元成分的关系的重要性尚未得到很好的定义。本应用程序中提出的工作的总体目标是开展一项涉及细胞水平电生理技术（布里斯托尔大学）和全动物研究（VCU）的协作性综合研究，以阐明PKC是否以及如何在吗啡和其他阿片类药物耐受性中发挥关键作用。本研究的另一个重要目标是阐明PKC在阿片类药物耐受性中的相对重要性，以及其他细胞蛋白，如PKA、arrest、GRK等。我们建议研究PKC的特定亚型，并在两个实验室中使用敲除小鼠和siRNA技术来阐明所涉及的机制。两个小组之间密切和持续的合作将为每个实验室的协调实验设计提供一种日常输入（电子邮件和数据传输）的机制。这种结果的即时交换将直接影响下一个实验的设计，在另一个实验室工作在不同的整合水平。该项目的具体目的是验证以下假设：(1)PKC在急性中度吗啡耐受中起主导作用，并且PKA和PKC一起参与慢性高水平的吗啡耐受，(2)对mu阿片受体具有更高疗效的阿片样物质在MORs中产生非PKC依赖性脱敏，并且整个动物对这些药物的耐受性不易被PKC抑制剂逆转，(3)GRKs，磷酸酶和gq偶联受体在一些阿片耐受性中发挥作用，(4)突触前位点有助于小鼠的more脱敏和阿片耐受性。当人们考虑到对阿片类药物的耐受性限制了它们在治疗患有慢性疼痛的癌症患者等患者中的使用时，这项研究与公共卫生的相关性受到赞赏。如果我们想要缓解这个问题，我们需要了解容忍的机制。此外，如果我们要解决药物滥用造成的巨大健康问题，就必须阐明耐受性和依赖性的机制。

DESCRIPTION (provided by applicant): Evidence exists in the literature and from our laboratories to implicate PKC in the mechanism of morphine tolerance. It is clear that its role varies with different levels and durations of morphine tolerance. Its role in tolerance to other opioids has not been studied in detail. The importance of PKC in relation to other neuronal constituents has not been well defined. The overall goal of the work proposed in this application is to carry out a collaborative, comprehensive investigation involving electrophysiological techniques at the cellular level (University of Bristol) with whole animal studies (VCU) to elucidate not only if but also how PKC plays a pivotal role in morphine and other opioid tolerance. Another important goal of the research is to elucidate the relative importance of PKC to other cellular proteins such as PKA, arrestins, GRK etc in opioid tolerance. We propose to study the specific isoforms of PKC and to use knockout mice and siRNA techniques in both laboratories to elucidate the mechanisms involved. Close and continual collaboration between the two groups will provide a mechanism for daily input (email and data transfer) into the design of coordinated experiments in each laboratory. This immediate interchange of result will directly affect the design of the next experiment in the other laboratory working at a different level of integration. The specific aims of the project are to test the hypotheses that (1) PKC plays the predominant role in acute moderate morphine tolerance, and that PKA along with PKC are involved in chronic higher levels of morphine tolerance,(2) that opioids with a higher efficacy at mu opioid receptors produce a non-PKC dependent desensitization at MORs and tolerance to these agents in the whole animal is less easily reversed by PKC inhibitors, (3) GRKs, phosphatases and Gq-coupled receptors play a role in some opioid tolerances and (4) that presynaptic sites contribute to both MOR desensitization and opioid tolerance in mice. The relevance of this research to public health is appreciated when one considers that tolerance to opioids limits their use in treating patients such as those with cancer who have chronic pain. We need to understand the mechanisms of tolerance if we are going to alleviate this problem. Also it is essential that we elucidate the mechanisms of tolerance and dependence if we are going to solve the enormous health problems caused by drug abuse.