Leibniz Institute of Photonic Technology Jena, Albert-Einstein-Str. 9, 07745 Jena, Germany.
Analyst. 2017 Nov 20;142(23):4405-4414. doi: 10.1039/c7an00592j.
Senescent cells contribute to tissue aging and dysfunction. Therefore, detecting senescent cells in skin is of interest for skin tumor diagnostics and therapy. Here, we studied the transition into senescence of human dermal fibroblasts (HDFs) in a three-dimensional (3D) human fibroblast-derived matrix (FDM). Senescent and proliferating cells were imaged by Raman spectroscopy (RS) and Fourier transform infrared (FTIR) spectroscopy. The obtained averaged spectra were analyzed using PLS-LDA. For these 3D cultured cells, RS and FTIR could clearly distinguish senescent from proliferating cells. For both techniques, we detected senescence-associated alterations in almost all cellular macromolecules. Furthermore, we identified different biochemical properties of 3D compared to two-dimensional (2D) cultured cells, indicating that cells in their natural, skin-like 3D environment act differently than in (2D) cell cultivations in vitro. Compared to 2D cultured cells, cells grown in 3D models displayed a sharper contrast between the proliferating and senescent state, also affecting the abundance of biomolecules including nucleic acids. The training accuracies of both vibrational spectroscopic techniques were >96%, demonstrating the suitability of these label-free measurements for detecting these cellular states in 3D skin models.
衰老细胞导致组织衰老和功能障碍。因此，检测皮肤中的衰老细胞对于皮肤肿瘤的诊断和治疗具有重要意义。在这里，我们研究了三维（3D）人成纤维细胞衍生基质（FDM）中人真皮成纤维细胞（HDF）向衰老的转变。通过拉曼光谱（RS）和傅里叶变换红外（FTIR）光谱对衰老和增殖细胞进行成像。使用 PLS-LDA 对获得的平均光谱进行分析。对于这些 3D 培养的细胞，RS 和 FTIR 可以清楚地区分衰老细胞和增殖细胞。对于这两种技术，我们都检测到了与衰老相关的几乎所有细胞大分子的改变。此外，我们还发现 3D 培养的细胞与 2D 培养的细胞具有不同的生化特性，这表明细胞在其自然的、类似皮肤的 3D 环境中的行为与体外（2D）细胞培养不同。与 2D 培养的细胞相比，在 3D 模型中生长的细胞在增殖和衰老状态之间表现出更明显的对比，这也影响了包括核酸在内的生物分子的丰度。两种振动光谱技术的训练准确率均>96%，证明这些无标记测量方法适用于检测 3D 皮肤模型中的这些细胞状态。
