Department of Endocrinology, Staff Hospital of Changqing Oilfield, Xi'an, 710018, China.
Department of General Internal Medicine, Staff Hospital of Changqing Oilfield, No. 20, Changqing West Road, Jinghe Development Zone, Gaoling District, Xi'an, 710018, China.
Mol Genet Genomics. 2024 Nov 27;299(1):109. doi: 10.1007/s00438-024-02203-9.
Pro-differentiation and anti-senescence treatment may be potential strategies for senile osteoporosis therapy. However, the regulatory mechanism underlying osteoblast differentiation and senescence in senile osteoporosis remain to be clarified. In the present study, the preosteoblast cell line MC3T3-E1 was used to induce osteoblast differentiation. The HO was applied to induce senescence. HO treatment significantly inhibited the expression of Wilms tumor 1-associating protein (WTAP), runtrelated transcription factor 2 (Runx2), Osterix and specific protein 1 (Sp1), inhibited the alkaline phosphatase (ALP) activity, upregulated the senescence-associated β-galactosidase (SA-β-Gal), and increased the mRNA levels of p16 and p21. WTAP overexpression significantly reversed the effect of HO, during the osteoblast differentiation of MC3T3-E1 cells. The RIP-qRT-PCR and MeRIP-qRT-PCR assays confirmed that N6-methyladenosine (mA) modification of Sp1 mRNA was significantly decreased by HO treatment, but was increased by WTAP overexpression. The mA modification of Sp1 mRNA significantly increased the stability of Sp1 mRNA. The ChIP-qRT-PCR assay and luciferase reporter gene assay showed that Sp1 could bind to the promoter of BMP2. BMP2 knockdown reversed the effect of Sp1 on osteoblast differentiation and senescence. In conclusion, WTAP increased BMP2 expression to promote osteoblast differentiation and inhibit osteoblast senescence via increasing mA methylation of Sp1 mRNA. This study sheds new light on our understanding of mechanisms underlying osteoblast differentiation and senescence, and provides potential strategies for senile osteoporosis therapy.
促分化和抗衰老治疗可能是老年性骨质疏松症治疗的潜在策略。然而，老年性骨质疏松症中破骨细胞分化和衰老的调控机制仍有待阐明。在本研究中，使用前成骨细胞系 MC3T3-E1 诱导成骨细胞分化。用 HO 诱导衰老。HO 处理显著抑制 Wilms 肿瘤 1 相关蛋白（WTAP）、成骨转录因子 2（Runx2）、Osterix 和特异性蛋白 1（Sp1）的表达，抑制碱性磷酸酶（ALP）活性，上调衰老相关β-半乳糖苷酶（SA-β-Gal），并增加 p16 和 p21 的 mRNA 水平。WTAP 过表达显著逆转了 HO 对 MC3T3-E1 细胞成骨分化的影响。RIP-qRT-PCR 和 MeRIP-qRT-PCR 检测证实，HO 处理显著降低了 Sp1 mRNA 的 N6-甲基腺苷（mA）修饰，但 WTAP 过表达增加了 mA 修饰。Sp1 mRNA 的 mA 修饰显著增加了 Sp1 mRNA 的稳定性。ChIP-qRT-PCR 检测和荧光素酶报告基因检测显示 Sp1 可以结合 BMP2 的启动子。BMP2 敲低逆转了 Sp1 对成骨细胞分化和衰老的影响。总之，WTAP 通过增加 Sp1 mRNA 的 mA 甲基化来增加 BMP2 的表达，从而促进成骨细胞分化并抑制成骨细胞衰老。本研究为我们理解成骨细胞分化和衰老的机制提供了新的视角，并为老年性骨质疏松症的治疗提供了潜在的策略。
