Bioenergetics of red blood cells regulated by hydrogen sulfide

生物能量学是指在真核生物中通过糖酵解以ATP的形式产生能量的过程。 无氧糖酵解发生在胞质溶胶中，其将葡萄糖转化为乳酸，同时每个葡萄糖分子产生2个ATP。有氧糖酵解在葡萄糖胞体中完成，通过氧化磷酸化（OXPHOS）从每个葡萄糖分子中产生30-32个ATP。 生物能量学的调节取决于线粒体是否存在、葡萄糖和氧水平以及其他内源性调节剂的作用。硫化氢（H2S）是一种重要的内源性因素。其生产和生物学的重要性在真核生物中已经知道了十多年。由我以前的NSERC发现赠款支持的研究已经证明，由其他研究人员的许多报告证实，H2S在哺乳动物细胞的胞质溶胶和胞浆中产生，并且H2S调节线粒体ATP的产生，促进线粒体生物合成，并影响细胞活力。成熟的哺乳动物红细胞（RBC）不具有线粒体，并且它们的生物能学依赖于无氧糖酵解，而禽类RBC具有功能性线粒体，并且它们的生物能学涉及无氧糖酵解和OXPHOS。哺乳动物和鸟类红细胞是否使用相同或不同的机制来产生H2S尚不清楚。H2S在调节红细胞的生物能学以及生存能力中的作用，在线粒体存在或不存在的情况下，还没有studied.We假设，H2S差异调节哺乳动物和鸟类红细胞中的无氧糖酵解和OXPHOS，对这些细胞的功能和生存产生不同的功能影响。本项目的目的是在无H2S的小鼠红细胞和含H2S的鸡红细胞中研究：1）内源性H2S的产生及其调节; 2）H2S对无氧糖酵解和OXPHOS的影响及其机制; 3）H2S调节的生物能量学对细胞存活和功能的影响;（4）与H_2S相比，多硫化物对生物能量学和细胞存活的影响。这些短期目标与我的研究生涯的长期目标，即阐明gasotransmitters，包括H2S，在真核生物的代谢和生物学的重要性。 拟议的计划可以帮助更好地了解红细胞的生物能量学如何受到H2S的调节，以维持这些细胞的寿命。新的光将阐明从哺乳动物红细胞连接内源性H2S代谢的进化挤压的意义。所获得的知识还将有助于设计基于H2S的策略，以专门调节生物能量依赖的细胞和身体功能，例如体外RBC的优化储存条件，氧气供应有限的高海拔适应，或运动和体育活动。

Bioenergetics is the process whereby energy is generated from glycolysis in eukaryotes in the form of ATP. Anaerobic glycolysis occurs in the cytosol, which converts glucose to lactate while generating 2 ATP per glucose molecule. Aerobic glycolysis is completed in the mitochondrion, producing 30-32 ATP from each molecule of glucose via oxidative phosphorylation (OXPHOS). The regulation of bioenergetics depends on whether mitochondria are present, glucose and oxygen levels, and the effects of other endogenous regulators. Hydrogen sulfide (H2S) is one important endogenous factor. Its production and biological importance in eukaryotes have been known for more than a decade. The research supported by my previous NSERC Discovery grants has demonstrated, confirmed by numerous reports from other researchers, that H2S is generated in both the cytosol and mitochondrion in mammalian cells and that H2S regulates mitochondrial ATP production, promotes mitochondrial biogenesis, and affects cell viability. Mature mammalian red blood cells (RBCs) do not possess mitochondria and their bioenergetics relies on anaerobic glycolysis whereas avian RBCs have functional mitochondria and their bioenergetics involves both anaerobic glycolysis and OXPHOS. Whether mammalian and avian RBCs use the same or different mechanisms to produce H2S is unknown. The roles of H2S in the regulation of bioenergetics as well as viability of RBCs, in the presence or absence of mitochondria, have not been studied.We hypothesize that H2S differentially regulates anaerobic glycolysis and OXPHOS in mammalian and avian RBCs, exerting different functional impacts on the function and survival of these cells. The objectives of this program are to examine, in mitochondrion-free mouse RBCs and mitochondrion-containing chicken RBCs, 1) the production of endogenous H2S and its regulation; 2) the effects of H2S on anaerobic glycolysis and OXPHOS and the underlying mechanisms; 3) the impact of H2S-regulated bioenergetics on cellular survival and functions; and 4) the effects of polysulfide on bioenergetics and cell survival in comparison with those of H2S. These short-term objectives align with the long-term objective of my research career, i.e. to elucidate the metabolism and biological importance of gasotransmitters, including H2S, in eukaryotes. The proposed program can help better understand how the bioenergetics of RBCs is regulated by H2S to sustain the lifespan of these cells. New light will be shed on the significance of evolutionary extrusion of the mitochondrion from mammalian RBCs in connection to endogenous H2S metabolism. The knowledge gained will also help to devise H2S-based strategies to specifically regulate bioenergetics-dependent cellular and body functions, such as optimized storage conditions for RBCs in vitro, high altitude adaptation where oxygen supply is limited, or exercise and physical activities.