Wang Xiaohui, Su Ning
Department of Endocrinology, Gansu Provincial of Traditional Chinese Medicine, Lanzhou, Gansu 73000, China.
Department of Geriatrics, Hengshui People's Hospital, Hengshui, Hubei 053000, China.
Saudi J Biol Sci. 2021 Apr;28(4):2139-2145. doi: 10.1016/j.sjbs.2021.02.026. Epub 2021 Feb 17.
Diabetes mellitus is an ill-famed metabolic disorder with varied repercussions including delayed fracture healing. Wnt/β-catenin axis is known to play a tight pivotal role in the bone healing process. Substance P (SubP) is a neuropeptide with established positive modulatory functions in fracture healing and associated neuronal milieu. In this study, we performed local delivery of recombinant adenovirus of Dickkopf-1 (DKK1) into the fracture site to understand the antagonizing the role of DKK1 against substance P. Rats were segregated into 4 groups: (i) Fractured non-diabetic rats; (ii) Fractured T1D rats; T1D was provoked by using STZ 50 mg/kg for 5 consecutive days; (iii) Fractured T1D + SubP (50 mg/ml/Kg; i.p.; 30 min prior to fracture procedure); (iv) Fractured T1D + SubP + Ad-DKK1. Bone radiographs were taken using a Faxitron X-ray machine and the residual gap size was measured using an electric caliper. Western blotting was also performed to determine the protein expression levels of osteogenic markers (RUNX2, OSTX and OSTC) bone resorption markers (OPG, RANKL and RANK) and also Wnt-signalling markers (β-catenin, LRP5 and GSK-3β). We observed that SubP promoted osteogenesis (as indicated by RUNX2, OSTX and OSTC upregulation) and mitigated the bone resorption (as indicated by optimized OPG/RANKL/RANK axis) via activated Wnt signalling (manifested by upmodulated β-catenin and LRP5, with downmodulated GSK-3β levels. Activation of endogenous SubP or administration of exogenous mimics might counter-protect the fractured bone against the deforming effects of T1D.
糖尿病是一种声名狼藉的代谢紊乱疾病，具有多种影响，包括骨折愈合延迟。已知Wnt/β-连环蛋白轴在骨愈合过程中起着关键作用。P物质（SubP）是一种神经肽，在骨折愈合及相关神经微环境中具有已确定的正向调节功能。在本研究中，我们将Dickkopf-1（DKK1）重组腺病毒局部递送至骨折部位，以了解DKK1对P物质的拮抗作用。将大鼠分为4组：（i）骨折的非糖尿病大鼠；（ii）骨折的1型糖尿病大鼠；通过连续5天使用50mg/kg链脲佐菌素（STZ）诱发1型糖尿病；（iii）骨折的1型糖尿病 + P物质组（50mg/ml/Kg；腹腔注射；骨折手术前30分钟）；（iv）骨折的1型糖尿病 + P物质 + 腺病毒-DKK1组。使用Faxitron X光机拍摄骨X光片，并使用电子卡尺测量残余间隙大小。还进行了蛋白质印迹分析，以确定成骨标志物（RUNX2、OSTX和OSTC）、骨吸收标志物（OPG、RANKL和RANK）以及Wnt信号标志物（β-连环蛋白、LRP5和GSK-3β）的蛋白质表达水平。我们观察到，P物质通过激活Wnt信号（表现为β-连环蛋白和LRP5上调，GSK-3β水平下调）促进成骨（如RUNX2、OSTX和OSTC上调所示）并减轻骨吸收（如优化的OPG/RANKL/RANK轴所示）。内源性P物质的激活或外源性模拟物的给药可能会对骨折的骨骼起到保护作用，抵抗1型糖尿病的变形影响。
