Blockade of miR-29b-1-5p promotes MSC-mediated bone regeneration during aging

阻断 miR-29b-1-5p 可促进衰老过程中 MSC 介导的骨再生

• 批准号: 8783881
• 负责人: Samuel Herberg
• 金额: $ 5.23万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8783881
• 关键词: Address; Adult; Age; Age-Related Bone Loss; Aging; Biocompatible Materials; Biological Assay; Biomedical Engineering; Bone Injury; Bone Regeneration; COL1A1 gene; CXCR4 gene; Calvaria; Cellular biology; Characteristics; Clinical; Complex; Data; Defect; Degenerative polyarthritis; Development; Disease; Elderly; Encapsulated; Enzyme-Linked Immunosorbent Assay; Epidemic; Exhibits; Family; Foundations; Gene Expression; Gene Targeting; Genetic Translation; Healed; Health; Human; Hydrogels; Impaired wound healing; In Vitro; Individual; Injury; Intervention; Luciferases; Mediating; Mesenchymal; Mesenchymal Differentiation; MicroRNAs; Modeling; Molecular; Musculoskeletal System; Natural regeneration; Osteogenesis; Osteoporosis; Patients; Phenotype; Play; Polymers; Population; Process; Rattus; Regulator Genes; Reporter; Role; Signal Pathway; Signal Transduction; Sister; Staining method; Stains; Stromal Cell-Derived Factor 1; Stromal Cells; System; Therapeutic; Therapeutic Effect; Time; Tissues; Transcript; Untranslated Regions; Western Blotting; age related; aged; base; biodegradable polymer; biomaterial compatibility; bone; effective therapy; healing; improved; in vitro Assay; in vivo; inhibitor/antagonist; member; novel; osteogenic; osteoporosis with pathological fracture; pre-clinical; promoter; regenerative; skeletal injury; stem; treatment effect

DESCRIPTION (provided by applicant): A large body of evidence suggests that bone is a dynamic tissue that can heal spontaneously following injury. However, this regenerative process often fails in the geriatric population contributing to widespread aging- related injuries to the musculoskeletal system. Inhibition of mRNA translation by microRNAs (miRNAs) has emerged as an important regulator of osteogenic signaling pathways. Accordingly, miRNA dysregulation has been implicated in the onset and progression of osteoporosis and osteoarthritis. These findings provide a rational basis for the development of novel bone bioengineering therapies that target specific miRNAs in a spatially and temporally controlled fashion. Among its members, miR-29b-1-3p is considered a mature dominant miRNA species that facilitates osteogenic differentiation of human mesenchymal stem/stromal cells (MSCs). In contrast, little is known about miR-29b-1-5p, the other mature miRNA expressed from the same precursor, which until recently was thought of as a byproduct. We have preliminary evidence that miR-29b-1- 5p is anti-osteogenic and that MSCs isolated from geriatric patients exhibit elevated levels of miR-29b-1-5p compared to adult MSCs, while the expression of miR-29b-1-3p is unchanged. These novel findings suggest a pathogenic role for miR-29b-1-5p in aging-related defects in osteogenesis and bone regeneration. Based on these findings, we hypothesize that the miR-29b-1-5p/miR-29b-1-3p ratio increases with age thereby tilting the scale towards anti-osteogenic characteristics. We further hypothesize that inhibitors of miR-29b-1-5p (anti- miRNA therapy) would be effective in reversing anti-osteogenic effects and promoting bone regeneration with progressing age. In this proposal, we aim to elucidate the molecular basis by which miR-29b-1-5p suppresses osteogenic gene targets and disrupts osteogenic differentiation of MSCs with aging, and to determine the effects of altering miR-29b-1-5p levels on MSC-mediated local bone formation in vivo using novel polymer hydrogels. To address these aims, we will use a variety of molecular cell biology and functional assays prior to employing an established orthotopic bone injury model. These studies will provide preclinical evidence for the therapeutic potential of miR-29b-1-5p inhibitors to promote bone regeneration and also for an effective and improved delivery system for anti-miRNA therapy.

描述（由申请人提供）：大量证据表明骨骼是一种动态组织，受伤后可以自发愈合。然而，这种再生过程在老年人群中常常失败，导致肌肉骨骼系统广泛出现与衰老相关的损伤。 microRNA (miRNA) 对 mRNA 翻译的抑制已成为成骨信号通路的重要调节因子。因此，miRNA 失调与骨质疏松症和骨关节炎的发生和进展有关。这些发现为开发以空间和时间控制的方式靶向特定 miRNA 的新型骨生物工程疗法提供了合理的基础。在其成员中，miR-29b-1-3p 被认为是一种成熟的优势 miRNA 物种，可促进人间充质干细胞/基质细胞 (MSC) 的成骨分化。相比之下，人们对 miR-29b-1-5p 知之甚少，这是由同一前体表达的另一种成熟 miRNA，直到最近还被认为是副产品。我们有初步证据表明 miR-29b-1-5p 具有抗成骨作用，并且与成人 MSC 相比，从老年患者分离的 MSC 表现出 miR-29b-1-5p 水平升高，而 miR-29b-1-3p 的表达没有变化。这些新发现表明 miR-29b-1-5p 在成骨和骨再生的衰老相关缺陷中具有致病作用。基于这些发现，我们假设 miR-29b-1-5p/miR-29b-1-3p 比率随着年龄的增长而增加，从而使规模向抗成骨特征倾斜。我们进一步假设，随着年龄的增长，miR-29b-1-5p 抑制剂（抗 miRNA 疗法）将有效逆转抗成骨作用并促进骨再生。在本提案中，我们的目标是阐明 miR-29b-1-5p 抑制成骨基因靶标并破坏 MSC 随衰老的成骨分化的分子基础，并利用新型聚合物水凝胶确定改变 miR-29b-1-5p 水平对 MSC 介导的体内局部骨形成的影响。为了实现这些目标，我们将在采用已建立的原位骨损伤模型之前使用各种分子细胞生物学和功能测定。这些研究将为 miR-29b-1-5p 抑制剂促进骨再生的治疗潜力以及抗 miRNA 治疗的有效和改进的递送系统提供临床前证据。