Ding Fan, Zhang Weidong, Liu Ting, Rong Xing, Cui Yajun, Meng Lingxiao, Wang Luxu, Liu Bo, Li Minqi
Department of Bone Metabolism, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Research Center of Dental Materials and Oral Tissue Regeneration & Shandong Provincial Clinical Research Center for Oral Diseases, Jinan, People's Republic of China.
Center of Osteoporosis and Bone Mineral Research, Shandong University, Jinan, People's Republic of China.
Drug Des Devel Ther. 2025 Mar 25;19:2173-2188. doi: 10.2147/DDDT.S503930. eCollection 2025.
Diabetic osteoporosis (DOP), one of the usual complications in diabetic patients, poses a significant threat to bone health. Type H vessels in metaphysis and medial cortical bone are associated with osteogenesis. As a form of Vitamin K menaquinone-4 (MK-4) is a potential treatment for osteoporosis. We aimed to investigate whether MK-4 ameliorates DOP by promoting bone formation through protecting type H vessels and its associated mechanisms.
High fat diet (HDF) feeding and streptozotocin (STZ) injection were applied to establish a mouse model of type 2 diabetic osteoporosis (T2DOP). Micro-CT, Masson staining, HE staining and IHC staining were applied to observe bone mass and the osteoblastic ability of osteoblasts. Tissue immunofluorescence (IF) staining and flow cytometry were employed to assess alteration of type H blood vessels. In vitro, to evaluate the functional level and mitophagy of ECs under high glucose conditions, wound healing assay, tube formation assay, EdU assay and IF were employed. Osteogenic differentiation ability in vitro was evaluated by ALP staining, AR staining, Western blot and RT-qPCR.
MK-4 alleviated type H vessel injury and angiogenesis-dependent osteogenesis in DOP mice, thereby maintaining the bone mass. The vitro results showed that MK-4 could mitigate the dysfunction of ECs subjected to HG treatment, and further facilitate the osteogenic differentiation of MC3T3-E1 cells. Moreover, mechanism exploration found that PINK1/Parkin-mediated mitophagy was required for the impact of MK-4 on ECs. Meanwhile, ERK signal pathway is necessary for the improvement of MK-4 in PINK1/Parkin-mediated mitophagy.
MK-4 is capable of alleviating the PINK1/Parkin-mediated mitophagy of ECs via the ERK pathway, thereby facilitating angiogenesis-dependent bone formation and further ameliorating DOP.
糖尿病性骨质疏松症（DOP）是糖尿病患者常见的并发症之一，对骨骼健康构成重大威胁。干骺端和内侧皮质骨中的H型血管与骨生成有关。作为维生素K的一种形式，甲萘醌-4（MK-4）是骨质疏松症的一种潜在治疗方法。我们旨在研究MK-4是否通过保护H型血管及其相关机制促进骨形成来改善DOP。
采用高脂饮食（HDF）喂养和链脲佐菌素（STZ）注射建立2型糖尿病骨质疏松症（T2DOP）小鼠模型。应用显微CT、Masson染色、HE染色和免疫组化染色观察骨量和成骨细胞的成骨能力。采用组织免疫荧光（IF）染色和流式细胞术评估H型血管的变化。在体外，为了评估高糖条件下内皮细胞的功能水平和线粒体自噬，采用伤口愈合试验、管形成试验、EdU试验和IF。通过碱性磷酸酶（ALP）染色、茜素红（AR）染色、蛋白质免疫印迹法（Western blot）和逆转录定量聚合酶链反应（RT-qPCR）评估体外成骨分化能力。
MK-4减轻了DOP小鼠的H型血管损伤和血管生成依赖性骨生成，从而维持了骨量。体外实验结果表明，MK-4可以减轻高糖处理的内皮细胞功能障碍，并进一步促进MC3T3-E1细胞的成骨分化。此外，机制探索发现，MK-4对内皮细胞的影响需要PINK1/Parkin介导的线粒体自噬。同时，ERK信号通路是MK-4改善PINK1/Parkin介导的线粒体自噬所必需的。
MK-4能够通过ERK途径减轻内皮细胞的PINK1/Parkin介导的线粒体自噬，从而促进血管生成依赖性骨形成，进一步改善DOP。
