BLR&D Research Career Scientist Award

BLR

• 批准号: 9898226
• 负责人: Kin-Hing William Lau
• 金额: --
• 依托单位: VA LOMA LINDA HEALTHCARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9898226
• 关键词: Age; Aging; Area; Award; Binding; Biogenesis; Bone Development; Bone Diseases; Bone Resorption; Calcium; Cartilage; Cells; ChIP-seq; Chimeric Proteins; Chondrocytes; Chondrogenesis; Complex; DNA cassette; Degenerative polyarthritis; Development; Disease Progression; Enzymes; Epigenetic Process; Etiology; Female; Foundations; Fracture; Functional disorder; Funding; Genes; Genetic Transcription; Grant; Grant Review; Health; Health Care Costs; Hip Fractures; Human; In Vitro; Incidence; Inflammatory; Intra-Articular Injections; Investigation; Joints; Knee; Knockout Mice; Knowledge; Lead; Ligands; Mediating; Medical Care Costs; Messenger RNA; MicroRNAs; Military Personnel; Mission; Molecular; Morbidity - disease rate; Mus; Natural regeneration; Osteoclasts; Osteogenesis; Osteopenia; Osteoporosis; Osteoporosis prevention; Ovariectomy; Pain; Pathologic; Pathology; Pathway interactions; Patient Care; Patients; Phenotype; Phosphotyrosine; Physiological; Play; Population; Protein Overexpression; Protein Tyrosine Kinase; Protein Tyrosine Phosphatase; Proteins; Quality of life; Regimen; Regulation; Research; Rho-associated kinase; Role; Scientist; Signal Transduction; Synovial Membrane; Testing; Therapeutic; Transgenes; Transgenic Mice; Treatment Efficacy; United States National Institutes of Health; Up-Regulation; Veterans; Wasting Syndrome; Work; age related; arthropathies; articular cartilage; base; bone; bone loss; bone mass; career; chondrogenesis factor; conditional knockout; cytokine; disabling symptom; effective therapy; improved; in vivo; innovation; insight; interest; joint injury; macrophage; monocyte; new therapeutic target; novel; novel strategies; novel therapeutics; osteoporotic bone; overexpression; patient population; prevent; promoter; protein expression; screening; skeletal tissue; src-Family Kinases; subchondral bone; transcription factor

The current research focus of the nominee is two-fold: The first is to delineate a unique molecular mechanism regulating functional activity of osteoclasts that involves negative regulation of the expression of a distinctive osteoclastic protein-tyrosine phosphatase (PTP-oc), which is a potent activator of functional activity of mature osteoclasts, by microRNA-17 (miR17). This project is supported by a BLR&D Merit Review award and seeks to test 3 hypotheses: 1) resorption cytokines activates osteoclasts via suppression of miR17 expression; 2) conditional deletion of miR17 in osteoclasts increases PTP-oc expression, which in turn stimulates osteoclast activity via up-regulation of the PTP-oc signaling; and 3) conditional overexpression of miR17 in osteoclasts reduces PTP-oc expression and inhibits physiologically- and pathologically-induced bone resorption. It has three Aims: Aim 1 tests the first hypothesis by determining if treatment with resorption modulators regulates the promoter activity of miR17 in osteoclasts; demonstrating direct effects of resorption modulators on transcription of the miR17~92 gene; and performing ChIP-seq analysis to identify key transcription factors. Aim 2 tests the second hypothesis by characterizing the in vivo and in vitro bone and osteoclast phenotypes of osteoclast miR17~92 conditional knockout mice, determining effects of miR17~92 deficiency on PTP-oc mRNA level, the PTP-oc signaling, and resorption activity of osteoclasts, and determining whether re-introduction of miR17 into miR17~92 deficient osteoclasts would “restore” the osteoclast phenotype; and evaluating effects of miR17~92 deficiency on osteoclast differentiation. Aim 3 tests the third hypothesis by generating transgenic mice with conditional overexpression of miR17~92 in osteoclasts by crossing LysM-Cre mice with mice harboring the miR17~92 transgene downstream to a loxP-flanked Neo-STOP cassette at the ROSA locus, determining the effects of conditional overexpression of miR17~92 in osteoclasts on bone and osteoclast phenotypes, and if overexpression of miR17~92 in osteoclasts would blunt the ovariectomy- and calcium depletion-induced bone resorption. This work should yield insights into how mature osteoclast activity is regulated, which is important in our overall understanding of the pathophysiology of various subtypes of osteoporosis and bone-wasting diseases. It may also provide novel drug targets (e.g., miR17) for screening of small molecular compounds for use to develop effective anti-resorption therapies for certain subtypes of osteoporosis. The second focus is to develop an innovative EphA4-based small molecular therapeutic strategy to prevent and treat osteoarthritis (OA) and posttraumatic OA (PTOA). This project is funded by a DoD Idea Development award. The rationale of this project is based on the exciting discovery of an opposing regulatory effects of the forward signaling of EphA4 on osteoclasts (inhibiting bone resorption) as opposed to on chondrocytes (promoting cartilage biogenesis). This project seeks to capitalize these unique opposing actions of the EphA4 forward signaling on osteoclasts vs. chondrocytes to develop a novel strategy that would simultaneously reduce degradation of articular cartilage/subchondral bone and enhance regeneration of articular cartilage. It has three Aims. Aim 1 determines whether treatment of monocytes/macrophages/synoviocytes isolated from PTOA synovium with soluble EfnA4-fc protein suppresses secretion of pro-inflammatory cytokines and degradative enzymes, and if treatment of articular chondrocytes with EfnA4-fc would promote chondrocyte proliferation, maturation, and survival in vitro. Aim 2 seeks to develop and optimize an EphA4-binding EfnA-fc-based strategy, which involves direct intra-articular injection of a soluble EfhA-fc chimeric protein into the OA/PTOA joint. Aim 3 determines if administration of the optimized EfnA-fc-based strategy to the PTOA/OA synovium joint shortly after the creation of an intra-articular tibial plateau fracture in the knee prevents degradation of articular cartilage, and if this optimized EfnA-fc-based therapeutic strategy promotes regeneration of articular cartilage. This work should provide feasibility evidence for this EphA4-based therapeutic therapy for PTOA/OA.

被提名人目前的研究重点是两个方面：第一是描述一个独特的分子机制