Cellular and molecular mechanism underlying alcohol inhibition of bone fracture healing

酒精抑制骨折愈合的细胞和分子机制

• 批准号: 9907665
• 负责人: Jonathan Michael Eby
• 金额: $ 3.65万
• 依托单位: LOYOLA UNIVERSITY CHICAGO
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-01 至 2020-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9907665
• 关键词: Acetylcysteine; Alcohol consumption; Alcohols; Antioxidants; Appearance; Area; Attenuated; Bone callus; Caliber; Cartilage; Cell Differentiation Inhibition; Cell Lineage; Cell physiology; Chondrocytes; Chondrogenesis; Collagen; Complex; Data; Differentiation Antigens; Ethanol Metabolism; Exposure to; FOXO1A gene; Family; Fracture; Fracture Healing; Health Care Costs; Histologic; In Vitro; Individual; Injury; Laboratories; Literature; Mediating; Mesenchymal Differentiation; Mesenchymal Stem Cells; Microscopy; Modeling; Molecular; Morbidity - disease rate; Mus; Osteoblasts; Osteocytes; Oxidative Stress; Patients; Periosteum; Pharmacology; Physiological; Play; Process; Quantitative Reverse Transcriptase PCR; Reactive Oxygen Species; Reporter; Reporting; Risk; Risk-Taking; Rodent; Role; Signal Transduction; Site; Testing; Therapeutic Intervention; Time; WNT Signaling Pathway; Western Blotting; alcohol effect; alcohol exposure; attenuation; base; bone; bone health; cartilaginous; fracture risk; healing; in vivo; inhibitor/antagonist; insight; knock-down; mouse Cre recombinase; osteogenic; problem drinker; promoter; repaired; response; self-renewal; stem cell differentiation; tibia; transcription factor

7. Project Summary/Abstract This F31 application is to investigate the cellular and molecular mechanisms underlying alcohol inhibition of bone fracture healing. Alcohol consumption is associated with increased risk-taking and injuries leading to a bone fracture. In addition, patients using alcohol have an increased risk of fracture nonunion, which is associated with increased healthcare costs and substantial patient morbidity. Bone fracture repair is a complex process involving the differentiation of local periosteum mesenchymal stem cells (MSC) near the injury site into chondrocytes and osteoblasts to form a fracture callus. Our laboratory has previously reported that rodents exposed to episodic alcohol preceding a midline tibia fracture develop a deficient fracture callus as characterized by a reduced cartilaginous callus volume, diameter and histological evidence of inhibited cartilage maturation. These data suggest that alcohol may be inhibiting fracture callus formation by inhibiting the differentiation of MSC to chondro- osteo lineages. Alcohol exposure is known to produce intracellular reactive oxygen species (ROS), and ROS has been shown to play an important role in cellular signaling regulating MSC self-renewal and differentiation. However, the molecular mechanism connecting ROS to chondro-osteo differentiation inhibition has yet to be described. Activation of molecular oxidative stress responder family of forkhead box O (FoxO) transcription factors have been shown to be detrimental to overall bone health, and it has been previously reported that FoxO- specific signaling has been shown to antagonize Canonical Wnt signaling activity critical for MSC chondro-osteo lineage commitment. Recently, we have reported that FoxO1/3 activation is associated with decreased callus area following fracture injury in alcohol-exposed rodents. Based on these preliminary findings, we hypothesize that alcohol-exposure inhibits MSC to chondro-osteo differentiation within the fracture callus through ROS-mediated enhanced FoxO1/3 signaling. To test this hypothesis, we propose the following aims. Aim 1 will characterize alterations in MSC chondrogenic lineage differentiation within the fracture callus of alcohol- exposed rodents. Aim 2 will determine the effect of alcohol on primary MSC differentiation and whether attenuation of MSC FoxO1/3 signaling restores MSC differentiation. Overall, we expect this study will open new avenues for therapeutic intervention to attenuate the risks associated with alcohol consumption and bone fracture repair.

7.项目总结/摘要 本F31应用程序旨在研究酒精抑制骨的细胞和分子机制 骨折愈合饮酒与增加的冒险行为和导致骨骼损伤有关 骨折此外，使用酒精的患者发生骨折不愈合的风险增加，这与以下因素有关： 增加的医疗费用和大量的患者发病率。骨折修复是一个复杂的过程， 损伤部位附近的局部骨膜间充质干细胞（MSC）分化为软骨细胞， 成骨细胞形成骨折骨痂。我们的实验室以前曾报道，啮齿动物暴露于偶发性 中线胫骨骨折前的酒精会产生缺陷性骨折骨痂，其特征在于 软骨骨痂体积、直径和软骨成熟受抑制的组织学证据。这些数据 提示酒精可能通过抑制MSC向软骨细胞分化而抑制骨折骨痂形成， 骨谱系已知酒精暴露会产生细胞内活性氧（ROS），并且ROS 已被证明在调节MSC自我更新和分化的细胞信号传导中发挥重要作用。 然而，连接ROS与软骨-骨分化抑制的分子机制尚未被阐明。 介绍了叉头盒O（FoxO）转录的分子氧化应激应答器家族的激活 这些因素已被证明对整体骨骼健康有害，之前有报道称FoxO- 特异性信号传导已经显示出拮抗对于MSC软骨-骨分化至关重要的典型Wnt信号传导活性。 血统承诺最近，我们报道FoxO1/3激活与愈伤组织减少有关 暴露于酒精的啮齿动物骨折后的面积。基于这些初步发现，我们假设 酒精暴露抑制MSC在骨折愈伤组织内向软骨-骨分化， ROS介导的FoxO1/3信号转导增强。为了验证这一假设，我们提出了以下目标。要求1 将表征酒精-酒精混合物骨折骨痂内MSC软骨形成谱系分化的改变， 暴露的啮齿动物目的2将确定酒精对原代MSC分化的影响， MSC FoxO 1/3信号传导的减弱恢复MSC分化。总的来说，我们预计这项研究将开启新的 治疗干预的途径，以减轻与酒精消费和骨骼相关的风险 骨折修复