CD14: Biosynthesis, Trafficking and Secretion

CD14：生物合成、贩运和分泌

• 批准号: 7810106
• 负责人: Diego Fernando Nino
• 金额: $ 3.1万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-02-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7810106
• 关键词: Address; Admission activity; Anabolism; Bacteria; Binding; Binding Sites; CD14 gene; Cause of Death; Cell Wall; Cell membrane; Cell physiology; Cell surface; Cells; Cholesterol; Clathrin; Complex; Dynamin; Endocytosis Pathway; Endoplasmic Reticulum; Family; Geldanamycin; Generations; Glycoproteins; Glycosylphosphatidylinositols; HSP 90 inhibition; Health system; Heat shock proteins; Heat-Shock Proteins 90; Heat-Shock Response; Immune system; Impairment; Infection; Inflammatory Response; Intensive Care Units; Laboratories; Lead; Lipopolysaccharides; Membrane; Molecular Chaperones; Multiple Organ Failure; Mus; Myelogenous; Pathway interactions; Peptides; Plasma; Play; Post-Translational Protein Processing; Process; Protein Sorting Signals; Proteins; Public Health; Regulation; Role; Sepsis; Septic Shock; Signal Transduction; inhibitor/antagonist; macrophage; member; protein expression; protein folding; response; toll-like receptor 4; trafficking

DESCRIPTION (provided by applicant): Sepsis, a systemic inflammatory response to infection(l), is a major cause of death within the US. (1, 2) Therapy for sepsis is mainly supportive and frequently requires admission into intensive care units,(3) with a significant financial burden to the public health system.(4) Among the multiple etiologic factors triggering sepsis, infections by Gram (-) bacteria, rank as one of the most frequent. Lipopolysaccharide (LPS) is a key component of the cell wall of Gram (-) bacteria and a potent inducers of the inflammatory response (3). In fact, an overwhelming inflammatory response is responsible for the transition between sepsis and septic shock and subsequently multiple organ failure, which are responsible for the majority casualties from sepsis. The interaction of LPS with cells of the immune system, in particular macrophages (Mo), is via a complex between CDI4 and Toll-like receptor 4 (TLR4). In this complex, CD14 is the major binding site for LPS whereas TLR4 is involved in the signal transduction responsible for the inflammatory response. Recent findings from Dr. De Maio laboratory that have implicated the role of heat shock proteins (hsps) in the trafficking of CD14.(5) Treatment of a murine M0 line (J774 Cells) with Geldanamycin (GA), a specific inhibitor of Heat Shock protein - 90 (Hsp90) family, leads to increased internalization of the membrane bound form of CD14 (mCD14). Thus, Mos treated with GA show an impaired response to LPS.(5) In addition, GA is a potent inducer of the heat shock response.(6) Thus, the effect of GA on CD14 internalization could be due to inhibition of Hsp90 function or heat shock protein expression. These two hypotheses will be addressed in this project. Furthermore, CDM was observed to accumulate within the endoplasmic reticulum (ER) after GA treatment. Since Grp94 is the ER member of the Hsp90 family, its inhibition by GA may be responsible for CD14 ER accumulation, which could be due to the unfolding of this glycoprotein within the ER. in summary, this proposal aims to characterize the biosynthesis, ER retention, and trafficking of CDM after GA treatment. These studies may elucidate the role of hsps in these cellular processes.

描述(申请人提供)：败血症，一种对感染的全身性炎症反应(L)，是美国境内的主要死亡原因。(1，2)脓毒症的治疗主要是支持性的，经常需要进入重症监护病房，(3)对公共卫生系统造成巨大的经济负担。(4)在引发脓毒症的多种病因中，革兰氏(-)菌感染是最常见的因素之一。内毒素是革兰氏(-)细菌细胞壁的关键成分，也是炎症反应的有效诱导剂。事实上，压倒性的炎症反应是脓毒症和感染性休克之间过渡的原因，继而是多器官衰竭，这是脓毒症造成的大多数伤亡的原因。内毒素与免疫系统的细胞，特别是巨噬细胞(Mo)的相互作用是通过CDI4和Toll样受体4(TLR4)之间的复合体实现的。在这个复合体中，CD14是内毒素的主要结合部位，而TLR4参与了炎症反应的信号转导。De Maio博士实验室的最新发现表明，热休克蛋白(HSPs)在CD14的运输中发挥了作用。(5)用热休克蛋白-90(Hsp90)家族的特异性抑制剂格尔达那霉素(GA)处理小鼠M0细胞(J774细胞)，可增加CD14(MCD14)的膜结合形式(MCD14)的内化。此外，GA是热休克反应的有效诱导剂。(6)因此，GA对CD14内化的影响可能是通过抑制Hsp90功能或热休克蛋白表达而实现的。这两个假设将在这个项目中得到解决。此外，还观察到在GA处理后，CDM在内质网(ER)内积累。由于Grp94是Hsp90家族的内质网成员，GA对它的抑制可能是CD14内质网积聚的原因，这可能是由于这种糖蛋白在内质网内解折叠所致。综上所述，本提案旨在表征GA处理后CDM的生物合成、内质网保留和运输。这些研究可能阐明热休克蛋白在这些细胞过程中的作用。