骨质疏松症是一种代谢性疾病,骨质疏松性骨折(OPF)是其最严重的并发症之一。常忽略骨折周围肌肉对OPF愈合的影响。我们旨在阐明骨骼肌卫星细胞(SMSCs)在β-catenin促进OPF愈合中的作用。为了提高我们对SMSC的理解,让我们探索它作为治疗靶点的潜力。
骨骼肌是从对照非OPF或OPF患者中获得的,用于原代SMSCs培养(n=3,33%的女性,平均年龄60±15.52)。测量SMSCs的表达。在体内,3个月大的雌性C57BL/6小鼠接受OVX手术。三个月后,再次制作左胫骨骨折模型.对照组和治疗组(n=24,每组,female).治疗组用激动剂(蛇床子素)治疗。在7、14和28三个时间点检测肌肉中的SMSCs和骨折愈合(n=8、8、8,女性)。为了进一步澄清科学假设,我们创新性地使用Pax7-CreERT2/+;β-cateninfx/fx转基因小鼠(每组n=12,male).敲除SMSC中的β-catenin观察SMSCs的增殖和成骨分化,OPF治疗来自3月龄产仔阴性β-cateninfx/fx转基因小鼠的SMSCs的体外原代细胞。腺病毒CRE转染后,观察到SMSC的成肌和成骨分化。
我们发现人SMSCs降低OPF患者的增殖和成骨分化(-38.63%,P<0.05)。通过动物实验,发现β-catenin的激活促进骨折部位SMSC的增殖和成骨分化,从而加速骨折部位的愈合(189.47%,P<0.05)。为了证明这个观点,在体内Pax7-CreERT2/+;β-cateninfx/fx转基因小鼠实验,我们创新性地发现,敲除SMSC中的β-catenin会导致骨量和骨微结构的减少,并伴有骨折延迟愈合(-35.04%,P<0.001)。同时,通过体外培养实验,发现它们的肌源性(-66.89%,P<0.01)和成骨分化(-16.5%,P<0.05)能力下降。
这些结果为SMSCs直接促进OPF愈合提供了第一个实际证据,具有重要的临床意义,因为它可能有助于治疗OPFs的延迟愈合和不愈合。和动员自体干细胞疗法在骨科应用中的应用。
Osteoporosis is a metabolic disease, and osteoporotic fracture (OPF) is one of its most serious complications. It is often ignored that the influence of the muscles surrounding the fracture on the healing of OPF. We aimed to clarify the role of skeletal muscle satellite cells (SMSCs) in promoting OPF healing by β-catenin, to improve our understanding of SMSCs, and let us explore its potential as a therapeutic target.
Skeletal muscles were obtained from control non-OPF or OPF patients for primary SMSCs culture (n = 3, 33% females, mean age 60 ± 15.52). Expression of SMSCs was measured. In vivo, 3-month-old female C57BL/6 mice underwent OVX surgery. Three months later, the left tibia fracture model was again performed. The control and the treatment group (n = 24, per group, female). The treatment group was treated with an agonist (osthole). Detection of SMSCs in muscles and fracture healing at 7, 14, and 28 three time points (n = 8, 8, 8, female). To further clarify the scientific hypothesis, we innovatively used Pax7-CreERT2/+ ;β-cateninfx/fx transgenic mice (n = 12, per group, male). Knock out β-catenin in SMSC to observe the proliferation and osteogenic differentiation of SMSCs, and OPF healing. In vitro primary cells of SMSCs from 3-month-old litter-negative β-cateninfx/fx transgenic mice. After adenovirus-CRE transfection, the myogenic and osteogenic differentiation of SMSC was observed.
We find that human SMSCs reduced proliferation and osteogenic differentiation in patients with OPF (-38.63%, P < 0.05). And through animal experiments, it was found that activation of β-catenin promoted the proliferation and osteogenic differentiation of SMSC at the fracture site, thereby accelerating the healing of the fracture site (189.47%, P < 0.05). To prove this point of view, in the in vivo Pax7-CreERT2/+ ;β-cateninfx/fx transgenic mouse experiment, we innovatively found that knocking out β-catenin in SMSC will cause a decrease in bone mass and bone microstructure, and accompanied by delayed fracture healing (-35.04%, P < 0.001). At the same time, through in vitro SMSC culture experiments, it was found that their myogenic (-66.89%, P < 0.01) and osteogenic differentiation (-16.5%, P < 0.05) ability decreased.
These results provide the first practical evidence for a direct contribution of SMSCs to promote the healing of OPF with important clinical implications as it may help in the treatment of delayed healing and non-union of OPFs, and mobilization of autologous stem cell therapy in orthopaedic applications.