线粒体,对真核细胞功能至关重要的中央细胞器,将他们的影响力扩展到ATP生产之外,包括在细胞凋亡中的作用,钙信号,和生物合成。最近的研究聚焦了线粒体功能的两个新兴决定因素:线粒体内粘度和二氧化硫(SO2)水平。而最佳的线粒体粘度控制分子扩散和重要的过程,如氧化磷酸化,像差与神经退行性疾病有关,糖尿病,和癌症。同样,SO2是一种气体信号分子,调节能量途径和氧化应激反应;然而,失衡导致细胞毒性亚硫酸盐和亚硫酸氢盐积累,引发癌症和心血管异常等疾病。我们的研究重点是开发双通道荧光探针,在香豆素染料基质中应用吸电子受体,有助于监测活细胞中的线粒体粘度和SO2。该探针在650nm和558nm处区分荧光峰,允许按比例定量SO2,而不受其他硫物种的干扰。此外,它可以实现近红外粘度测定,特别是在线粒体内。研究采用了利用密度泛函理论(DFT)方法的理论计算来确定分子的几何形状并计算旋转能。值得注意的是,探针的吲哚部分表现出最低的旋转能量,定量为7.38kcals/mol。当包含在接受制霉菌素等药物的HeLa细胞内时,该探针具有增强的线粒体粘度动力学,莫能菌素,和细菌脂多糖(LPS)。总的来说,我们的创新方法阐明了复杂的线粒体因子,呈现对细胞能量学的变革性见解,氧化还原稳态,和线粒体相关疾病的治疗途径。
Mitochondria, central organelles pivotal for eukaryotic cell function, extend their influence beyond ATP production, encompassing roles in apoptosis, calcium signaling, and biosynthesis. Recent studies spotlight two emerging determinants of mitochondrial functionality: intramitochondrial viscosity and sulfur dioxide (SO2) levels. While optimal mitochondrial viscosity governs molecular diffusion and vital processes like oxidative phosphorylation, aberrations are linked with neurodegenerative conditions, diabetes, and cancer. Similarly, SO2, a gaseous signaling molecule, modulates energy pathways and oxidative stress responses; however, imbalances lead to cytotoxic sulfite and bisulfite accumulation, triggering disorders such as cancer and cardiovascular anomalies. Our research focused on development of a dual-channel fluorescent probe, applying electron-withdrawing acceptors within a coumarin dye matrix, facilitating monitoring of mitochondrial viscosity and SO2 in live cells. This probe distinguishes fluorescence peaks at 650 nm and 558 nm, allowing ratiometric quantification of SO2 without interference from other sulfur species. Moreover, it enables near-infrared viscosity determination, particularly within mitochondria. The investigation employed theoretical calculations utilizing Density Functional Theory (DFT) methods to ascertain molecular geometries and calculate rotational energies. Notably, the indolium segment of the probe exhibited the lowest rotational energy, quantified at 7.38 kcals/mol. The probe featured heightened mitochondrial viscosity dynamics when contained within HeLa cells subjected to agents like nystatin, monensin, and bacterial lipopolysaccharide (LPS). Overall, our innovative methodology elucidates intricate mitochondrial factors, presenting transformative insights into cellular energetics, redox homeostasis, and therapeutic avenues for mitochondrial-related disorders.