Clinical Research of Oral Connective Tissue Program

口腔结缔组织项目临床研究

• 批准号: 10244803
• 负责人: Martha Somerman
• 金额: $ 17.88万
• 依托单位: NATIONAL INSTITUTE OF ARTHRITIS AND MUSCULOSKELETAL AND SKIN DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10244803
• 关键词: Affect; Age; Alkaline Phosphatase; Ankylosis; Binding; C-terminal; Cells; Cementocyte; Cementogenesis; Cervical; Chicago; Clinical; Clinical Research; Collaborations; Connective Tissue; Data; Defect; Dental; Dental Cementum; Dental Enamel; Dentin; Development; Diagnosis; Diphosphates; Disease; Dysplasia; Epigenetic Process; Exhibits; Extramural Activities; Familial tumoral calcinosis; Fostering; Gene Proteins; Genes; Genetic Predisposition to Disease; Histologic; Histology; Human; Hypoxia Inducible Factor; Individual; Institutional Review Boards; Knockout Mice; Lead; Maintenance; Manuscripts; Maryland; Mathematics; Medical History; Metabolic Diseases; Metabolism; Minerals; Molecular Analysis; Mutation; National Institute of Dental and Craniofacial Research; Natural regeneration; New Jersey; Newborn Infant; North Carolina; Ohio; Oral; Orthodontic; Osteoclasts; Osteolysis; Pathology; Patients; Pattern; Phenotype; Proteins; Protocols documentation; Publications; Publishing; RANK protein; Recording of previous events; Reporting; Research Personnel; Roentgen Rays; Root Resorption; Saliva; Sampling; School Dentistry; Skeleton; Structure; Thick; Tissues; Tooth Movement; Tooth root structure; Tooth structure; United States National Institutes of Health; Universities; Work; arterial calcification of infancy; base; bone; craniofacial complex; deciduous tooth; density; exome sequencing; extracellular; gene function; human subject; inorganic phosphate; kindred; loss of function mutation; member; microCT; microbial; mineralization; novel; plasma cell membrane glycoprotein PC-1; programs; repaired; skeletal

Project A. Determine genetic susceptibility and immunopathological mechanisms contributing to idiopathic tooth root resorption Background: Previously, we reported that BSP KO mice exhibit a tooth root resorption phenotype. Based on this finding, we sought to identify human subjects exhibiting multiple idiopathic cervical root resorption (MICRR), a familial pattern of MICRR with suggested genetic susceptibility. Following IRB approval from the University of Detroit Mercy School of Dentistry and NIH, dental/medical histories, x-rays, saliva samples, and extracted teeth were collected from a kindred (4 affected and 4 unaffected members) exhibiting MICRR. Whole exome sequencing using saliva identified a mutation in the c-terminal region of IRF8 responsible for overactive osteoclast function. Results were published in JBMR, 2019 and this project transitioned to University Maryland with Dr. Thumbigere-Math (K99/R00 recipient). Ongoing: We continue to collaborate with Dr. Thumbigere-Math as the lead on the IRF8 project, with other NIH collaborators, Drs. Ozato and Holland, with a publication in Bone, 2020 (see below). Collaborations were established with other clinicians: Dr. Steve Russo (Chicago, IL), Dr. Thomas Schneider (New Jersey), and Dr. Janina Golob Deeb (VCU), who have seen patients with rapid MICRR. Dr. Golob Deeb noticed a potential association with MICRR and cessation of denosumab, leading us to collaborate with Drs. Alison Boyce and Marie Kao-Hseih (NIDCR) to conduct dental exams on patients taking denosumab for fibrous dysplasia. We have also set up a collaboration with an expert in microbial analyses, Dr. Purnima Kumar (Ohio State University), to determine the microbial profile of plaque samples from Russos patient. Further, we analyzed teeth obtained from Dr. Betty Hajishengallis (U. Penn), from a patient with missing ossicles and idiopathic root resorption, diagnosed with familial expansile osteolysis (age 10, mutations in the TNFRSF11 gene encoding RANK protein, over expression) and noted cementum defects. Project B. Disorders of mineralization: In collaboration with NIDCR clinical researchers and other IC clinicians, we have been examining individuals with mineralized tissue metabolism disorders for alterations in tissues/cells of the DOC complex. 1. Mutations in key regulators of Pi/PPi. Mineralization of skeleton and teeth is tightly regulated by levels of extracellular inorganic phosphate (Pi) and pyrophosphate (PPi). Three regulators that control pericellular concentrations of Pi and PPi include tissue-nonspecific alkaline phosphatase (TNAP), progressive ankylosis protein (ANK), and ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1). Inactivation of these factors results in mineralization disorders affecting teeth and their supporting structures. We examined the effect of decreased PPi on development and maturation of teeth in human subjects (4) with generalized arterial calcification of infancy (GACI), who harbor loss-of-function mutations in ENPP1. Subjects reported a history of infraocclusion or over-retained primary teeth,poor orthodontic tooth movement, suggesting altered mineral metabolism as a contributing factor. Micro-CT analyses of extracted primary teeth from GACI subjects revealed marked increase cervical cementum thickness and density vs. age-matched healthy control teeth. There were no differences in enamel and dentin densities between GACI and control teeth. Histology revealed dramatically expanded cervical cementum in GACI teeth, including cementocyte-like cells and unusual patterns of cementum resorption and repair. Micro-CT analysis of Enpp1 knock-out mouse molars revealed a marked increase in acellular cementum thickness and volume. Collectively, these findings report a novel dental phenotype in GACI and further support our hypothesis that Pi/PPi modulation is as a key mechanism for regulating cementogenesis across species. Thumbigere-Math V et al., JDR, 2018. Ongoing: We have continued to examine patients with Pi/PPi disorders at NIH CRC as well as analyzing exfoliated or extracted teeth from patients with Pi/PPi disorders. We have also included patients with ABCC6 (ATP Binding Cassette Subfamily C Member 6), which is associated with some cases of GACI. We have also been examining teeth from patients with disorders associated with skeletal disturbances, e.g., human familial tumoral calcinosis (collaborators: Dr. Michael Collins, manuscript submitted July 2020) , patients with Hypoxia-inducible factor 2a mutations (collaborators: Drs. Pacak, Rosenblum, and Zhuang). For controls, in collaboration with North Carolina State University and Duke under the Newborn Epigenetics Study, we are obtaining exfoliated primary teeth from healthy individuals.

项目A确定导致特发性牙根吸收的遗传易感性和免疫病理机制 背景：此前，我们报道了BSP KO小鼠表现出牙根吸收表型。基于这一发现，我们试图确定表现出多发性特发性颈根吸收(MICRR)的人类受试者，MICRR是一种具有遗传易感性的MICRR家族模式。在底特律大学牙科慈善学院和NIH批准IRB之后，从一个表现为MICRR的家庭(4名受影响成员和4名未受影响成员)收集牙科/病史、X光、唾液样本和拔除的牙齿。使用唾液进行的整个外显子组测序发现了IRF8 c-末端区域的一个突变，该突变导致破骨细胞功能过度活跃。结果发表在2019年的JBMR上，该项目与Thumbigere-Math博士(K99/R00获奖者)一起过渡到马里兰大学。 正在进行中：我们继续与Thumbigere-Math博士合作，作为IRF8项目的负责人，与NIH的其他合作者Ozato博士和Holland博士合作，并在2020年出版了一本《骨，2020》(见下文)。与其他临床医生建立了合作关系：Steve Russo博士(伊利诺伊州芝加哥)、Thomas Schneider博士(新泽西州)和Janina Golob Deeb博士(VCU)，他们见过患有快速MICRR的患者。Golob Deeb博士注意到与MICRR和停用Denosumab之间存在潜在的关联，这导致我们与Alison Boyce博士和Marie Kao-Hseih博士(NIDCR)合作，对服用Denosumab治疗纤维结构不良的患者进行牙科检查。我们还与微生物分析专家Purnima Kumar博士(俄亥俄州立大学)建立了合作关系，以确定Russos患者斑块样本的微生物图谱。此外，我们分析了从宾夕法尼亚大学Betty Hajishengallis博士那里获得的牙齿，该牙齿来自一名患有听小骨缺失和特发性牙根吸收的患者，该患者被诊断为家族性扩张性骨溶解(10岁，编码RANK蛋白的TNFRSF11基因突变，过度表达)，并注意到牙骨质缺陷。 项目B：矿化无序： 与NIDCR临床研究人员和其他IC临床医生合作，我们一直在检查患有矿化组织代谢障碍的患者DOC复合体的组织/细胞的变化。 1.PI/PPI关键调控因子的突变。骨骼和牙齿的矿化受到细胞外无机磷(PI)和焦磷(PPI)水平的严格调控。控制细胞周围PI和PPI浓度的三种调节因子包括组织非特异性碱性磷酸酶(TNAP)、进行性强直蛋白(ANK)和胞外核苷酸焦磷酸/磷酸二酯酶1(ENPP1)。这些因素的失活会导致影响牙齿及其支持结构的矿化障碍。我们研究了PPI降低对患有婴儿期全身性动脉钙化(GACI)的受试者(4)牙齿发育和成熟的影响，这些受试者中存在ENPP1功能缺失突变。受试者报告了咬合不足或乳牙过度保留，正畸牙齿移动不良的病史，这表明矿物质代谢的改变是一个促成因素。对GACI受试者拔除的乳牙进行的Micro-CT分析显示，与年龄匹配的健康对照牙齿相比，颈部牙骨质厚度和密度显著增加。Gaci组和对照牙牙釉质和牙本质密度无明显差异。组织学显示Gaci牙颈部牙骨质显著扩大，包括牙骨质细胞样细胞和不寻常的牙骨质吸收和修复模式。对Enpp1基因敲除的小鼠磨牙进行的Micro-CT分析显示，无细胞牙骨质厚度和体积显著增加。总之，这些发现报告了GACI中一种新的牙齿表型，并进一步支持了我们的假设，即PI/PPI调节是调节跨物种牙骨质形成的关键机制。Thumbigere-Math V等人，JDR，2018年。 正在进行中：我们继续在NIH CRC检查PI/PPI障碍患者，并分析PI/PPI障碍患者的脱落或拔除的牙齿。我们还包括了ABCC6(ATP结合盒C亚家族成员6)的患者，这与一些GACI病例有关。我们还检查了与骨骼紊乱相关的疾病患者的牙齿，例如人类家族性肿瘤钙质沉着症(合作者：Michael Collins博士，2020年7月提交的手稿)、低氧诱导因子2a突变患者(合作者：Pacak、Rosenblum和Zang博士)。在对照方面，我们与北卡罗来纳州立大学和杜克大学合作，在新生表观遗传学研究下，从健康人身上获得了剥离的乳牙。