Therapeutic targeting of GPCR Gbetagamma-GRK2 in osteoarthritis

GPCR Gbetagamma-GRK2 在骨关节炎中的治疗靶向

• 批准号: 10355423
• 负责人: Fadia Ali Kamal
• 金额: $ 33.39万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-21 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10355423
• 关键词: Agonist; Antidepressive Agents; Attenuated; Binding; Cartilage; Cells; Chondrocytes; Clinical; Clinical Research; Clinical Trials; Collagen; Coupled; Data; Degenerative polyarthritis; Development; Differentiation and Growth; Disease; Enzymes; Epiphysial cartilage; FDA approved; Financial Hardship; Future; G Protein-Coupled Receptor Signaling; G protein coupled receptor kinase; G-Protein-Coupled Receptors; GTP-Binding Protein alpha Subunits; GTP-Binding Protein alpha Subunits, Gs; GTP-Binding Proteins; Genetic; Healthcare Systems; Heart Diseases; Homeostasis; Human; Hypertrophy; In Vitro; Kidney Diseases; Knockout Mice; Medial meniscus structure; Mediating; Modeling; Mus; Natural regeneration; Operative Surgical Procedures; PI3K/AKT; PTH gene; Parathyroid Hormone Receptor; Paroxetine; Pathologic; Pathway interactions; Patients; Pharmaceutical Preparations; Phase; Phenotype; Phosphotransferases; Physical Function; Physiological; Play; Process; Production; Proteoglycan; Quality of life; Receptor Signaling; Regulation; Reporting; Role; Signal Transduction; System; Testing; Therapeutic Agents; Treatment Efficacy; Work; arthropathies; cartilage degradation; cartilage regeneration; cell growth; conditional knockout; desensitization; effective therapy; gallein; human tissue; in vivo; inhibitor; mouse model; new therapeutic target; novel; novel therapeutic intervention; pre-clinical; prevent; protective effect; receptor; receptor internalization; recruit; regenerative; small molecule; small molecule inhibitor; therapeutic target

Abstract Osteoarthritis (OA) is a debilitating disease of the joints involving progressive cartilage degeneration, with no disease modifying therapy available. Chondrocytes, the cellular component of cartilage, regulate cartilage homeostasis by modulating matrix turnover via secretion of proteoglycans and collagen as well as matrix-degrading enzymes. In OA, articular chondrocytes acquire an aberrant phenotype where they undergo differentiation and hypertrophy (CH) with increased production of matrix degrading enzymes leading to cartilage degeneration. G protein-coupled receptors (GPCRs) is a superfamily of receptors coupled to intracellular G-proteins. Agonist binding to a GPCR activates its G- protein a subunit (Ga) physiologic signaling. A parallel G-protein bg subunit (Gbg) activation and recruitment of GPCR kinases (GRK2 particularly) leads to GPCR internalization and signal termination. GRK2 expression and Gbg-GRK2 signaling are pathologically elevated in several diseases, leading to GPCR desensitization and loss of Ga signaling. Importantly, we and others have recently reported the therapeutic efficacy of Gbg-GRK2 inhibition, both by rescuing Ga physiologic activity and by inhibiting direct downstream pathological signaling that promotes cell growth and differentiation; this was achieved using both novel small molecules and FDA-approved drugs. Chondrocytes are rich in type 1 parathyroid hormone receptor (PTH1R, a GRCR), where Gas and PTH1R are key regulators of CH, both are under tight regulation by Gbg-GRK2. However, the role of Gbg-GRK2 signaling in CH and OA remains unknown. Our preliminary work to establish the role of Gbg-GRK2 in CH during OA indicates that GRK2 expression and activity are increased in articular chondrocytes of both OA patients and mice with posttraumatic OA. Interestingly, in vitro and in vivo Gbg-GRK2 inhibition attenuated CH and cartilage degeneration in mice with DMM (surgical destabilization of the medial meniscus to induce OA). These preliminary findings support our overarching hypothesis that: Gbg-GRK2 signaling plays a central role in CH during OA, and its inhibition represents a novel therapeutic strategy for OA. To validate our hypothesis we will use chondrocyte conditional knockout mice and small molecule Gbg and GRK2 inhibitors in an in vivo OA mouse model and utilize different in vitro systems (both murine and human), to (1) determine the role of GRK2 signaling in articular CH in OA, (2) determine the therapeutic efficacy of small molecule Gbg-GRk2 inhibitors in OA, and (3) determine the role of Gbg-GRK2 signaling in PTH1R chondro-protective/regenerative effect in OA. These studies enable us to discover a novel therapeutic strategy and therapeutic agents for OA (both novel and FDA-approved) in a preclinical setting, thus laying the grounds for our future clinical study to establish a novel effective OA therapy.

抽象的 骨关节炎 (OA) 是一种使关节衰弱的疾病，涉及进行性软骨退化，但无疾病 可用修改疗法。软骨细胞是软骨的细胞成分，通过以下方式调节软骨稳态： 通过分泌蛋白聚糖和胶原蛋白以及基质降解酶来调节基质周转。在OA中， 关节软骨细胞获得异常表型，它们经历分化和肥大（CH） 基质降解酶的产生增加，导致软骨退化。 G蛋白偶联受体 (GPCR) 是与细胞内 G 蛋白偶联的受体超家族。激动剂与 GPCR 结合可激活其 G- 蛋白质 a 亚基 (Ga) 生理信号传导。并行 G 蛋白 bg 亚基 (Gbg) 激活和 GPCR 募集 激酶（特别是 GRK2）导致 GPCR 内化和信号终止。 GRK2 表达和 Gbg-GRK2 GPCR 信号在多种疾病中病理性升高，导致 GPCR 脱敏和 Ga 信号丢失。 重要的是，我们和其他人最近报道了 Gbg-GRK2 抑制的治疗功效，两者都是通过拯救 Ga 生理活性并通过抑制直接下游病理信号，促进细胞生长和 差异化；这是通过使用新型小分子和 FDA 批准的药物来实现的。软骨细胞富含 1 型甲状旁腺激素受体（PTH1R，GRCR），其中 Gas 和 PTH1R 是 CH 的关键调节因子，两者均受 Gbg-GRK2 的严格监管。然而，Gbg-GRK2 信号在 CH 和 OA 中的作用仍不清楚。我们的 确定 Gbg-GRK2 在 OA 期间 CH 中的作用的初步工作表明 GRK2 表达和活性 OA 患者和患有创伤后 OA 的小鼠的关节软骨细胞均增加。有趣的是，体外和体内 Gbg-GRK2 抑制可减轻 DMM 小鼠的 CH 和软骨变性（内侧内侧手术不稳定） 半月板诱发 OA）。这些初步发现支持我们的总体假设：Gbg-GRK2 信号传导发挥作用 在 OA 期间的 CH 中发挥着核心作用，其抑制代表了 OA 的一种新的治疗策略。为了验证我们的 假设我们将在体内使用软骨细胞条件敲除小鼠和小分子Gbg和GRK2抑制剂 OA 小鼠模型并利用不同的体外系统（小鼠和人类），以 (1) 确定 GRK2 的作用 OA 关节 CH 中的信号传导，(2) 确定小分子 Gbg-GRk2 抑制剂在 OA 中的治疗功效，以及 (3)确定Gbg-GRK2信号在OA中PTH1R软骨保护/再生作用中的作用。这些研究 使我们能够发现一种新的 OA 治疗策略和治疗药物（新颖且经 FDA 批准） 临床前环境，从而为我们未来的临床研究奠定了基础，以建立一种新型有效的 OA 疗法。