Cell Culture Laboratory, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
Biomaterials Laboratory, Instituto Militar de Engenharia, Rio de Janeiro, RJ, Brazil.
J Biomed Mater Res A. 2019 Jun;107(6):1303-1313. doi: 10.1002/jbm.a.36643. Epub 2019 Feb 23.
The major role of integrins is to mediate cell adhesion but some of them are involved in the osteoblasts-titanium (Ti) interactions. In this study, we investigated the participation of integrins in osteoblast differentiation induced by Ti with nanotopography (Ti-Nano) and with microtopography (Ti-Micro). By using a PCR array, we observed that, compared with Ti-Micro, Ti-Nano upregulated the expression of five integrins in mesenchymal stem cells, including integrin β3, which increases osteoblast differentiation. Silencing integrin β3, using CRISPR-Cas9, in MC3T3-E1 cells significantly reduced the osteoblast differentiation induced by Ti-Nano in contrast to the effect on T-Micro. Concomitantly, integrin β3 silencing downregulated the expression of integrin αv, the parent chain that combines with other integrins and several components of the Wnt/β-catenin and BMP/Smad signaling pathways, all involved in osteoblast differentiation, only in cells cultured on Ti-Nano. Taken together, our results showed the key role of integrin β3 in the osteogenic potential of Ti-Nano but not of Ti-Micro. Additionally, we propose a novel mechanism to explain the higher osteoblast differentiation induced by Ti-Nano that involves an intricate regulatory network triggered by integrin β3 upregulation, which activates the Wnt and BMP signal transductions. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1303-1313, 2019.
整合素的主要作用是介导细胞黏附，但其中一些也参与了成骨细胞与钛（Ti）的相互作用。在这项研究中，我们研究了整合素在具有纳米形貌（Ti-Nano）和微形貌（Ti-Micro）的钛诱导成骨细胞分化中的作用。通过使用 PCR 阵列，我们观察到与 Ti-Micro 相比，Ti-Nano 上调了间充质干细胞中五种整合素的表达，包括增加成骨细胞分化的整合素β3。使用 CRISPR-Cas9 沉默 MC3T3-E1 细胞中的整合素β3，与对 Ti-Micro 的作用相比，显著降低了 Ti-Nano 诱导的成骨细胞分化。同时，整合素β3 的沉默下调了整合素αv 的表达，整合素αv 是与其他整合素结合的主链，以及 Wnt/β-catenin 和 BMP/Smad 信号通路的几个组成部分，所有这些都参与了成骨细胞分化，仅在细胞培养在 Ti-Nano 上时下调。总之，我们的研究结果表明整合素β3 在 Ti-Nano 的成骨潜力中起着关键作用，但在 Ti-Micro 中则没有。此外，我们提出了一种新的机制来解释 Ti-Nano 诱导的更高的成骨细胞分化，该机制涉及整合素β3 上调引发的复杂调控网络，该网络激活了 Wnt 和 BMP 信号转导。 2019 年 Wiley 期刊公司。J 生物医学材料 Res Part A:107A:1303-1313.
