Department of Oral Physiology, Periodontal Diseases Signaling Network Research Center, Dental and Life Science Institute, Pusan National University, School of Dentistry, Yangsan, South Korea.
Department of Oral and Maxillofacial Surgery, Dental Research Institute and Dental and Life Science Institute, Pusan National University, School of Dentistry, Yangsan, South Korea.
J Cell Physiol. 2022 Aug;237(8):3381-3393. doi: 10.1002/jcp.30814. Epub 2022 Jun 13.
Cytoplasmic serine/threonine Pim kinases have emerged as important modulators of immune regulation and oncology. However, their regulatory roles in bone remodeling remain obscure. Here, we aimed to determine the roles of Pim kinases in periodontal disease (PD), focusing on the regulation of osteoclastogenesis and bone resorptive activity. We investigated Pim kinases expression in PD by analyzing data from the online Gene Expression Omnibus database and using ligature-induced periodontitis mouse model. The expression of Pim kinases during receptor activator of nuclear factor kB ligand (RANKL)-induced osteoclastogenesis was assessed in mouse bone marrow-derived macrophages (BMMs) using reverse transcription polymerase chain reaction. Osteoclast differentiation and bone resorption activity were respectively verified by tartrate-resistant acid phosphatase staining and dentin disc-based bone resorption assays. We silenced and overexpressed Pim-2 using small interfering RNA (siRNA) and retroviral vector, respectively, to investigate the molecular mechanisms underlying Pim-2 regulation in RANKL-induced osteoclastogenesis and bone resorption activity. Upregulated expression of Pim-2 was observed in both patients with PD and periodontitis-affected mouse gingival tissues. siRNA-mediated silencing of Pim-2 in BMMs diminished RANKL-induced resorptive activity without affecting osteoclastogenesis. Moreover, RANKL-triggered stimulation of a3 isoform, which is a subunit of vacuolar-type ATPase, was selectively attenuated in BMMs on silencing Pim-2. The overexpression of Pim-2 with a retroviral vector stimulated the a3 subunit, thus inducing bone resorption activity. Taken together, these results suggest that Pim-2 acts as a major modulator of osteoclastic activity by regulating a3 isoform expression in PD.
细胞质丝氨酸/苏氨酸 Pim 激酶已成为免疫调节和肿瘤学的重要调节剂。然而，它们在骨重塑中的调节作用尚不清楚。在这里，我们旨在确定 Pim 激酶在牙周病（PD）中的作用，重点关注破骨细胞生成和骨吸收活性的调节。我们通过分析在线基因表达综合数据库中的数据并使用结扎诱导的牙周炎小鼠模型来研究 PD 中 Pim 激酶的表达。使用逆转录聚合酶链反应评估核因子 kB 受体激活剂（RANKL）诱导的破骨细胞生成过程中 Pim 激酶的表达。通过抗酒石酸酸性磷酸酶染色和牙本质盘骨吸收测定分别验证破骨细胞分化和骨吸收活性。我们使用小干扰 RNA（siRNA）和逆转录病毒载体分别沉默和过表达 Pim-2，以研究 Pim-2 在 RANKL 诱导的破骨细胞生成和骨吸收活性中的调节分子机制。在 PD 患者和受牙周炎影响的小鼠牙龈组织中均观察到 Pim-2 的表达上调。在 BMMs 中，siRNA 介导的 Pim-2 沉默减弱了 RANKL 诱导的吸收活性而不影响破骨细胞生成。此外，在沉默 Pim-2 的 BMMs 中，RANKL 触发的 vacuolar-type ATPase 亚基 a3 同工型的刺激被选择性减弱。逆转录病毒载体过表达 Pim-2 刺激 a3 亚基，从而诱导骨吸收活性。总之，这些结果表明，Pim-2 通过调节 PD 中 a3 同工型的表达，作为破骨细胞活性的主要调节剂。
