背景:异补骨脂素(ISO)在促进成骨细胞分化和抑制破骨细胞形成方面的作用已得到证实,但是ISO通过调节代谢改善糖皮质激素诱导的骨质疏松(GIOP)的潜在机制尚不清楚。
方法:本研究旨在基于ISO在GIOP中的功效,通过非靶向代谢组学阐明ISO治疗GIOP的机制。最初,我们建立了GIOP雌性小鼠模型,并使用micro-CT检测评估ISO的治疗效果,生物力学测试,血清钙(Ca),和磷(P)水平检测,连同使用苏木精和曙红(HE)的组织学分析,Masson,和抗酒石酸酸性磷酸酶(TRAP)染色。随后,非靶向代谢组学用于研究ISO对GIOP小鼠血清代谢物的影响。进行RT-qPCR和Western印迹分析以测量与这些代谢物相关的酶的水平。在代谢组学结果的基础上,我们探讨了ISO对环磷酸鸟苷(cGMP)/蛋白激酶G(PKG)通路的影响及其在介导成骨细胞分化中的作用.
结果:我们的研究结果表明,ISO干预有效地增强了GIOP小鼠的骨微结构和强度。减轻病理性损伤,例如骨小梁的结构损伤,胶原纤维减少,和增加的破骨细胞,同时改善GIOP小鼠血清Ca和P水平。非靶向代谢组学显示嘌呤代谢是对照组和GIOP组之间的共同途径,以及ISO高剂量(ISOH)组和GIOP组之间。ISO干预上调肌苷和腺苷水平,鸟苷一磷酸水平下调,腺苷脱氨酶(ADA)表达增加,并降低cGMP特异性3',5'-环磷酸二酯酶(PDE5)表达。此外,ISO干预升高血清cGMP水平,PKGI和PKGII在骨组织中的表达上调,以及Runt相关转录因子2(Runx2)和Osterix的表达,血清碱性磷酸酶(ALP)活性增加。
结论:总之,ISO能够增强GIOP小鼠的骨微结构和骨强度,提高其Ca,P,ALP水平,这可能与ISO通过cGMP/PKG通路调节嘌呤代谢和促进成骨细胞分化有关。这表明ISO是治疗GIOP的潜在药物。然而,还需要进一步的研究来探索ISO的具体靶点和临床应用。
BACKGROUND: The effects of Isopsoralen (ISO) in promoting osteoblast differentiation and inhibiting osteoclast formation are well-established, but the mechanism underlying ISO\'s improvement of Glucocorticoid- Induced Osteoporosis (GIOP) by regulating metabolism remains unclear.
METHODS: This study aims to elucidate the mechanism of ISO treatment for GIOP through non-targeted metabolomics based on ISO\'s efficacy in GIOP. Initially, we established a GIOP female mouse model and assessed ISO\'s therapeutic effects using micro-CT detection, biomechanical testing, serum calcium (Ca), and phosphorus (P) level detection, along with histological analyses using hematoxylin and eosin (HE), Masson, and tartrate-resistant acidic phosphatase (TRAP) staining. Subsequently, non-targeted metabolomics was employed to investigate ISO\'s impact on serum metabolites in GIOP mice. RT-qPCR and Western blot analyses were conducted to measure the levels of enzymes associated with these metabolites. Building on the metabolomic results, we explored the effects of ISO on the cyclic Guanosine Monophosphate (cGMP)/Protein Kinase G (PKG) pathway and its role in mediating osteoblast differentiation.
RESULTS: Our findings demonstrate that ISO intervention effectively enhances the bone microarchitecture and strength of GIOP mice. It mitigates pathological damage, such as structural damage in bone trabeculae, reduced collagen fibers, and increased osteoclasts, while improving serum Ca and P levels in GIOP mice. Non-- targeted metabolomics revealed purine metabolism as a common pathway between the Control and GIOP groups, as well as between the ISO high-dose (ISOH) group and the GIOP group. ISO intervention upregulated inosine and adenosine levels, downregulated guanosine monophosphate levels, increased Adenosine Deaminase (ADA) expression, and decreased cGMP-specific 3\',5\'-cyclic phosphodiesterase (PDE5) expression. Additionally, ISO intervention elevated serum cGMP levels, upregulated PKGI and PKGII expression in bone tissues, as well as the expression of Runt-related transcription factor 2 (Runx2) and Osterix, and increased serum Alkaline Phosphatase (ALP) activity.
CONCLUSIONS: In summary, ISO was able to enhance the bone microstructure and bone strength of GIOP mice and improve their Ca, P, and ALP levels, which may be related to ISO\'s regulation of purine metabolism and promotion of osteoblast differentiation mediated by the cGMP/PKG pathway. This suggests that ISO is a potential drug for treating GIOP. However, further research is still needed to explore the specific targets and clinical applications of ISO.