Uncovering the dual anabolic and anti-catabolic effects of Pyk2 inhibition on bone mass

揭示 Pyk2 抑制对骨量的双重合成代谢和抗分解代谢作用

基本信息

批准号：
10522662
负责人：
ANGELA BRUZZANITI
金额：
$ 50.08万
依托单位：
INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-08-22 至 2027-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10522662
关键词：
Actins Address Adverse event Aging Alzheimer&apos s Disease Architecture Arm Bones Biological Markers Bone Diseases Bone Tissue Bone remodeling C57BL/6 Mouse Cardiovascular Diseases Categories Chemicals Clinical Clinical Trials Collagen Data Deposition Deterioration Dimerization Dual-Energy X-Ray Absorptiometry Effectiveness Elderly man Elderly woman Enzyme-Linked Immunosorbent Assay Estradiol Estrogen Receptor alpha Estrogen Receptor beta Estrogen Receptors Exhibits Female Focal Adhesion Kinase 1 Focal Adhesions Fracture Functional disorder Genetic Genotype Goals Gonadal Steroid Hormones Hindlimb Suspension In Vitro Investigation Knowledge Lead Mechanical Stimulation Menopause Minerals Modeling Mus Osteoblasts Osteoclasts Osteocytes Osteogenesis Osteoporosis Osteoporosis prevention Osteoporotic Phenotype Property Protein Tyrosine Kinase Proteins Public Health Raloxifene Raman Spectrum Analysis Reporting Role Selective Estrogen Receptor Modulators Serum Sex Differences Signal Transduction Testing Thick Thinness Tissues Ubiquitin Woman antagonist bone bone cell bone loss bone mass bone quality bone strength cathepsin K clinical effect clinically relevant falls human female improved in vitro activity in vivo inhibitor kinase inhibitor male mechanical properties men middle age multicatalytic endopeptidase complex novel strategies novel therapeutics osteogenic preservation prevent response seal sex skeletal substantia spongiosa translational impact translational potential ubiquitin mediated proteasome degradation

项目摘要

SUMMARY. Bone loss is accelerated in menopausal women, and more generally in both men and women with aging. Current anti-resorptive and osteoanabolic therapies are generally prescribed only after pronounced bone loss, and all can have adverse clinical effects. Dual-acting agents that are both osteoanabolic and anti-resorptive may offer novel approaches to increase bone mass. The Pyk2 tyrosine kinase is dual-acting, both decreasing osteoblast (OB) activity and increasing osteoclast (OC) resorption. Despite a similar increase in cortical microarchitecture in male and female Pyk2-/- mice, only females exhibit increased cancellous bone mass and mechanical properties, suggesting sex-specific differences in tissue level properties. In preliminary studies, we found that ovariectomized Pyk2-/- female mice supplemented with 17β-estradiol (E2) have additively higher bone mass than WT, and that ulnar loaded Pyk2-/- males (females not tested) exhibit higher bone formation rate, suggesting enhanced osteogenic responses in vivo. Pyk2-/- OBs have enhanced mineralizing activity in vitro, which is further stimulated by 17β-estradiol (E2) and raloxifene, a clinically-approved selective estrogen receptor modulator (SERM). Pyk2-/- OBs exhibit reduced levels of estrogen receptor, ERα, due to its ubiquitin-proteasome degradation, and we found that ERβ antagonists prevent the E2-stimulated increase in Pyk2-/- OB activity, suggesting an increase in E2-ERβ signaling. On the other hand, Pyk2-/- OCs exhibit defective OC resorption activity, and in the presence of E2, OC formation and survival are reduced compared to WT OCs. Our Specific Aims will test the hypothesis that Pyk2 acts via distinct E2-ERα/ERβ-regulated mechanisms to exert dual- modulating effects that repress OB activity and promote OC resorption. In Aim 1, we will demonstrate the role of Pyk2 in the anabolic versus catabolic arms of the bone remodeling cycle by examining 4-, 12- and 21-month mice in which Pyk2-deletion is targeted to either OBs with collagen type 1a, 2.3-Cre (Pyk2Col2.3) or mature OCs with cathepsin K-Cre (Pyk2CatK). In addition, Pyk2Col2.3 mice will be subject to tibial anabolic loading, while Pyk2CatK mice will be examined after hindlimb unloading-induced bone loss. In Aim 2, we will determine if bone mass is preserved after sex steroid depletion (gonadectomy) of 4-month male/female Pyk2Col2.3 mice (due to elevated osteogenesis) and Pyk2CatK mice (due to reduced resorption), and if E2 or raloxifene will additively improve bone mass. We will dissect the Pyk2 mechanisms that regulate ERα degradation/stability, and effects on ERα/ERβ dimerization, and E2-ERβ signaling in OBs and OBs in vitro. In Aim 3, we will establish the non-inferiority of a Pyk2-selective inhibitor in preventing/reversing age-associated decline of bone mass and mechanical properties in 12-month C57BL/6 female mice, compared to a broad-acting inhibitor of focal adhesion kinases, and raloxifene. Clinical translational impact will be demonstrated using OBs and OCs prepared from male/female human donors in vitro. Together, these studies will investigate Pyk2 inhibition as a dual, osteoanabolic and anti- resorptive approach to reverse bone loss and improve bone quality/strength in osteoporosis and aging.

摘要：更年期女性骨质流失加速，男性和女性更普遍。目前的抗骨吸收和骨合成代谢疗法通常仅在骨明显出现后进行。损失，所有这些都可能产生不良的临床影响，既具有骨合成代谢作用又具有抗骨吸收作用。可能提供增加骨量的新方法 Pyk2 酪氨酸激酶具有双重作用，既可以减少骨量，又可以减少骨量。成骨细胞（OB）活性和破骨细胞（OC）吸收增加，尽管皮质也有类似的增加。在雄性和雌性 Pyk2-/- 小鼠的微结构中，只有雌性表现出松质骨量增加，并且机械特性，表明组织水平特性的性别特异性差异。发现补充 17β-雌二醇 (E2) 的去卵巢 Pyk2-/- 雌性小鼠的骨质含量更高质量比 WT 更大，并且尺骨负载 Pyk2-/- 的男性（女性未测试）表现出更高的骨形成率，表明 Pyk2-/- OB 增强了体内成骨反应，增强了体外矿化活性， 17β-雌二醇 (E2) 和雷洛昔芬（一种临床批准的选择性雌激素受体）进一步刺激 Pyk2-/- OB 由于其泛素蛋白酶体而表现出雌激素受体 ERα 水平降低。降解，我们发现 ERβ 拮抗剂可以阻止 E2 刺激的 Pyk2-/- OB 活性增加，表明 E2-ERβ 信号传导增强；另一方面，Pyk2-/- OC 表现出 OC 吸收缺陷。活性，并且在存在 E2 的情况下，与 WT OC 相比，OC 的形成和存活率降低。目标将测试 Pyk2 通过不同的 E2-ERα/ERβ 调节机制发挥双重作用的假设抑制 OB 活性并促进 OC 吸收的调节作用在目标 1 中，我们将展示其作用。通过检查 4、12 和 21 个月，了解 Pyk2 在骨重塑周期的合成代谢与分解代谢臂中的作用 Pyk2 缺失靶向具有 1a 型胶原蛋白、2.3-Cre (Pyk2Col2.3) 的 OB 或成熟 OC 的小鼠此外，Pyk2Col2.3 小鼠将承受胫骨合成代谢负荷，而 Pyk2CatK 则将受到组织蛋白酶 K-Cre (Pyk2CatK) 的影响。在目标 2 中，我们将在后肢卸载引起的骨质流失后对小鼠进行检查，以确定骨量是否为 4 个月大的雄性/雌性 Pyk2Col2.3 小鼠的性类固醇消耗（性腺切除术）后保留（由于升高成骨）和 Pyk2CatK 小鼠（由于吸收减少），并且 E2 或雷洛昔芬是否会额外改善骨骼我们将剖析调节 ERα 降解/稳定性的 Pyk2 机制以及对 ERα/ERβ 的影响。在目标 3 中，我们将确定 OB 和 OB 中的二聚化和 E2-ERβ 信号传导的非劣效性。 Pyk2 选择性抑制剂可预防/逆转与年龄相关的骨量和机械性能下降与广泛作用的粘着斑激酶抑制剂相比，在 12 个月大的 C57BL/6 雌性小鼠中，将使用男性/女性制备的 OB 和 OC 来证明雷洛昔芬的临床转化影响。这些研究将共同研究 Pyk2 抑制作为双重、骨合成代谢和抗肿瘤药物的作用。骨质疏松症和衰老过程中逆转骨质流失并改善骨质量/强度的再吸收方法。