Department of Biochemistry, Medical University Pleven, 5800 Pleven, Bulgaria.
Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
Int J Mol Sci. 2024 May 26;25(11):5795. doi: 10.3390/ijms25115795.
Mesenchymal stem cells (MSCs), pivotal for tissue repair, utilize collagen to restore structural integrity in damaged tissue, preserving its organization through concomitant remodeling. The non-enzymatic glycation of collagen potentially compromises MSC communication, particularly upon advancing the process, underlying various pathologies such as late-stage diabetic complications and aging. However, an understanding of the impact of early-stage collagen glycation on MSC interaction is lacking. This study examines the fate of in vitro glycated rat tail collagen (RTC) upon exposure to glucose for 1 or 5 days in contact with MSCs. Utilizing human adipose tissue-derived MSCs (ADMSCs), we demonstrate their significantly altered interaction with glycated collagen, characterized morphologically by reduced cell spreading, diminished focal adhesions formation, and attenuated development of the actin cytoskeleton. The morphological findings were confirmed by ImageJ 1.54g morphometric analysis with the most significant drop in the cell spreading area (CSA), from 246.8 μm for the native collagen to 216.8 μm and 163.7 μm for glycated ones, for 1 day and 5 days, respectively, and a similar trend was observed for cell perimeter 112.9 μm vs. 95.1 μm and 86.2 μm, respectively. These data suggest impaired recognition of early glycated collagen by integrin receptors. Moreover, they coincide with the reduced fibril-like reorganization of adsorbed FITC-collagen (indicating impaired remodeling) and a presumed decreased sensitivity to proteases. Indeed, confirmatory assays reveal diminished FITC-collagen degradation for glycated samples at 1 day and 5 days by attached cells (22.8 and 30.4%) and reduced proteolysis upon exogenous collagenase addition (24.5 and 40.4%) in a cell-free system, respectively. The mechanisms behind these effects remain uncertain, although differential scanning calorimetry confirms subtle structural/thermodynamic changes in glycated collagen.
间充质干细胞（MSCs）在组织修复中起着关键作用，它们利用胶原蛋白来恢复受损组织的结构完整性，通过同时进行重塑来保持其组织的结构。胶原蛋白的非酶糖基化可能会损害 MSC 的通讯，特别是在该过程进展时，这是各种病理的基础，如晚期糖尿病并发症和衰老。然而，人们对早期胶原蛋白糖基化对 MSC 相互作用的影响了解甚少。本研究检查了在与 MSC 接触时，体外糖基化大鼠尾胶原蛋白（RTC）在暴露于葡萄糖 1 天或 5 天后的命运。我们利用人脂肪组织来源的间充质干细胞（ADMSCs），证明了它们与糖基化胶原蛋白的相互作用发生了显著改变，其形态特征为细胞铺展减少，焦点黏附形成减少，肌动蛋白细胞骨架发育减弱。ImageJ 1.54g 形态计量学分析证实了这些形态学发现，糖基化胶原蛋白的细胞铺展面积（CSA）的下降最为明显，从天然胶原蛋白的 246.8μm 分别下降到 1 天和 5 天的 216.8μm 和 163.7μm，细胞周长也出现了类似的趋势，从 112.9μm 分别下降到 95.1μm 和 86.2μm。这些数据表明整合素受体对早期糖基化胶原蛋白的识别受损。此外，这些数据与吸附的 FITC-胶原蛋白（表明重塑受损）的纤维状重新组织减少以及假定的对蛋白酶敏感性降低相符。事实上，确证性测定显示，在无细胞系统中，附着细胞对糖基化样本的 FITC-胶原蛋白降解减少，1 天和 5 天分别为 22.8%和 30.4%，外加胶原酶时的蛋白水解减少，1 天和 5 天分别为 24.5%和 40.4%。这些影响的机制尚不清楚，尽管差示扫描量热法证实了糖基化胶原蛋白的细微结构/热力学变化。
