Craniofacial Anomalies and Regeneration Section, National Institute of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, 20892, USA.
Sci Rep. 2024 Oct 27;14(1):25610. doi: 10.1038/s41598-024-76992-9.
Excessive dietary fat intake increases plasma lipid levels and has been associated with reduced bone mineral density (BMD) and increased risk of osteoporotic fracture, especially in older postmenopausal women. The objective of this study was to investigate whether there are sex-related differences in lipid metabolism that could have an impact on large-scale bone regeneration. Because ribs provide a unique exception as the only bones capable of completely regenerating large-scale defects, we used a rib resection mouse model in which human features are recapitulated. After 10 days of exposure to a low-fat diet or high-fat diet (HFD), we performed large-scale rib resection surgeries on male and female mice (6-7 weeks old) with deletion of the low-density lipoprotein (LDL) receptor (Ldlr) and age- and sex-matched wild-type (WT) mice were used as controls. Plasma analysis showed that short-term exposure to HFD significantly increases total cholesterol, LDL cholesterol, and triglycerides levels in Ldlr mice but not in WT, with no differences between males and females. However, under HFD, callus bone volume was significantly reduced exclusively in male Ldlr mice when compared to WT, although these differences were no longer apparent by 21 days after resection. Regardless of diet or genotype, BMD of regenerated ribs did not differ significantly between groups, although male mice typically had lower average BMD values. Together, these results suggest that short-term hyperlipidemia has transient effects on large-scale bone regeneration exclusively in male mice.
过量的膳食脂肪摄入会增加血浆脂质水平,并与降低骨密度(BMD)和增加骨质疏松性骨折风险相关,尤其是在老年绝经后妇女中。本研究的目的是探讨脂质代谢是否存在性别相关差异,从而对大规模骨再生产生影响。由于肋骨是唯一能够完全再生大规模缺陷的骨骼,提供了一个独特的例外,因此我们使用了一种肋骨切除小鼠模型,其中重现了人类的特征。在低脂饮食或高脂肪饮食(HFD)暴露 10 天后,我们对 LDL 受体(Ldlr)缺失的雄性和雌性小鼠(6-7 周龄)以及年龄和性别匹配的野生型(WT)小鼠进行了大规模肋骨切除手术。血浆分析表明,短期暴露于 HFD 可显著增加 Ldlr 小鼠的总胆固醇、LDL 胆固醇和甘油三酯水平,但在 WT 小鼠中则没有,且雄性和雌性之间没有差异。然而,在 HFD 下,与 WT 相比,雄性 Ldlr 小鼠的骨痂骨体积明显减少,尽管切除后 21 天这些差异不再明显。无论饮食或基因型如何,再生肋骨的 BMD 在各组之间均无显著差异,尽管雄性小鼠的平均 BMD 值通常较低。综上所述,这些结果表明,短期高脂血症对雄性小鼠的大规模骨再生具有短暂影响。