Aging Institute of UPMC, The University of Pittsburgh School of Medicine, 100 Technology Dr, Pittsburgh, PA 15219, USA.
Molecular Biosensor and Imaging Center, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA.
Genes (Basel). 2023 Feb 14;14(2):485. doi: 10.3390/genes14020485.
Oxidative nuclear DNA damage increases in all tissues with age in multiple animal models, as well as in humans. However, the increase in DNA oxidation varies from tissue to tissue, suggesting that certain cells/tissues may be more vulnerable to DNA damage than others. The lack of a tool that can control dosage and spatiotemporal induction of oxidative DNA damage, which accumulates with age, has severely limited our ability to understand how DNA damage drives aging and age-related diseases. To overcome this, here we developed a chemoptogenetic tool that produces 8-oxoguanine (8-oxoG) at DNA in a whole organism, . This tool uses di-iodinated malachite green (MG-2I) photosensitizer dye that generates singlet oxygen, O, upon fluorogen activating peptide (FAP) binding and excitation with far-red light. Using our chemoptogenetic tool, we are able to control generation of singlet oxygen ubiquitously or in a tissue-specific manner, including in neurons and muscle cells. To induce oxidative DNA damage, we targeted our chemoptogenetic tool to histone, that is expressed in all cell types. Our results show that a single exposure to dye and light is able to induce DNA damage, promote embryonic lethality, lead to developmental delay, and significantly reduce lifespan. Our chemoptogenetic tool will now allow us to assess the cell autonomous versus non-cell autonomous role of DNA damage in aging, at an organismal level.
氧化的核 DNA 损伤随着年龄的增长在多种动物模型以及人类中都会在所有组织中增加。然而，DNA 氧化的增加在不同的组织之间有所不同，这表明某些细胞/组织可能比其他组织更容易受到 DNA 损伤。由于缺乏一种可以控制剂量和时空诱导氧化 DNA 损伤的工具，这种损伤会随着年龄的增长而积累，因此我们对 DNA 损伤如何导致衰老和与年龄相关的疾病的理解受到了严重限制。为了克服这一问题，我们在这里开发了一种化学遗传学工具，可以在整个生物体中产生 DNA 中的 8-氧鸟嘌呤（8-oxoG）。该工具使用二碘化孔雀石绿（MG-2I）光敏染料，在氟源激活肽（FAP）结合并使用远红光激发时会产生单线态氧 O。使用我们的化学遗传学工具，我们能够以普遍或组织特异性的方式控制单线态氧的产生，包括在神经元和肌肉细胞中。为了诱导氧化的 DNA 损伤，我们将我们的化学遗传学工具靶向组蛋白，该蛋白在所有细胞类型中都有表达。我们的结果表明，单次暴露于染料和光就能够诱导 DNA 损伤，导致胚胎致死、发育迟缓，并显著降低寿命。我们的化学遗传学工具现在将使我们能够在生物体水平上评估 DNA 损伤在衰老过程中的自主与非自主作用。
