Dou Mengjia, Li Yazhou, Sun Ziqiao, Li Lei, Rao Wei
CAS Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China; School of Engineering Science, University of Chinese Academy of Sciences, Beijing 100049, China; Beijing Key Laboratory of Cryo-Biomedical Engineering, Beijing 100190, China.
CAS Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China; School of Energy and Power Engineering, Beihang University, Beijing 100191, China.
Sci Bull (Beijing). 2019 Dec 15;64(23):1795-1804. doi: 10.1016/j.scib.2019.09.028. Epub 2019 Sep 30.
The successful cryopreservation of organs is a strong and widespread demand around the world but faces great challenges. The mechanisms of cold tolerance of organisms in nature inspirit researchers to find new solutions for these challenges. Especially, the thermal, mechanical, biological and biophysical changes during the regulation of freezing tolerance process should be studied and coordinated to improve the cryopreservation technique and quality of complex organs. Here the cold tolerance of the Japanese carpenter ants, Camponotus japonicus Mayr, was greatly improved by using optimal protocols and feeding on L-proline-augmented diets for 5 days. When cooling to -27.66 °C, the survival rate of frozen ants increased from 37.50% ± 1.73% to 83.88% ± 3.67%. Profiling of metabolites identified the concentration of whole-body L-proline of ants increased from 1.78 to 4.64 ng g after 5-day feeding. High L-proline level, together with a low rate of osmotically active water and osmotically inactive water facilitated the prevention of cryoinjury. More importantly, gene analysis showed that the expression of ribosome genes was significantly up-regulated and played an important role in manipulating freezing tolerance. To the best of our knowledge, this is the first study to link genetic variation to the enhancement of ants' cold tolerance by feeding exogenous cryoprotective compound. It is worth noting that the findings provide the theoretical and technical foundation for the cryopreservation of more complex tissues, organs, and living organisms.
器官的成功冷冻保存是全球范围内强烈且广泛的需求，但面临巨大挑战。自然界中生物的耐寒机制启发研究人员为这些挑战寻找新的解决方案。特别是，在调节耐冻过程中，应研究并协调热、机械、生物和生物物理变化，以改进冷冻保存技术和复杂器官的质量。在此，通过采用优化方案并以添加L-脯氨酸的饲料喂养日本木工蚁（Camponotus japonicus Mayr）5天，其耐寒性得到了极大提高。当冷却至-27.66°C时，冷冻蚂蚁的存活率从37.50%±1.73%提高到83.88%±3.67%。代谢物分析表明，喂养5天后，蚂蚁全身L-脯氨酸的浓度从1.78增加到4.64 ng/g。高L-脯氨酸水平，以及低比例的渗透活性水和非渗透活性水，有助于预防冷冻损伤。更重要的是，基因分析表明核糖体基因的表达显著上调，并在调节耐冻性方面发挥了重要作用。据我们所知，这是第一项将遗传变异与通过喂食外源性冷冻保护化合物增强蚂蚁耐寒性联系起来的研究。值得注意的是，这些发现为更复杂的组织、器官和生物体的冷冻保存提供了理论和技术基础。
