Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, 2600 Ramiro Barcelos Street-Attached, Porto Alegre, RS, 90035-003, Brazil.
Programa de Pós-Graduação em Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, 500 Sarmento Leite Street, Porto Alegre, RS, 90035-190, Brazil.
Cell Biochem Biophys. 2023 Dec;81(4):683-695. doi: 10.1007/s12013-023-01161-0. Epub 2023 Aug 17.
Ethylmalonic encephalopathy (EE) is a severe inherited metabolic disorder that causes tissue accumulation of hydrogen sulfide (sulfide) and thiosulfate in patients. Although symptoms are predominantly neurological, chronic hemorrhagic diarrhea associated with intestinal mucosa abnormalities is also commonly observed. Considering that the pathophysiology of intestinal alterations in EE is virtually unknown and that sulfide and thiosulfate are highly reactive molecules, the effects of these metabolites were investigated on bioenergetic production and transfer in the intestine of rats. We observed that sulfide reduced NADH- and FADH-linked mitochondrial respiration in the intestine, which was avoided by reduced glutathione (GSH) but not by melatonin. Thiosulfate did not change respiration. Moreover, both metabolites markedly reduced the activity of total, cytosolic and mitochondrial isoforms of creatine kinase (CK) in rat intestine. Noteworthy, the addition of GSH but not melatonin, apocynin, and Trolox (hydrosoluble vitamin E) prevented the change in the activities of total CK and its isoforms caused by sulfide and thiosulfate, suggesting a direct protein modification on CK structure by these metabolites. Sulfide further increased thiol content in the intestine, suggesting a modulation in the redox state of these groups. Finally, sulfide and thiosulfate decreased the viability of Caco-2 intestinal cells. Our data suggest that bioenergetic impairment caused by sulfide and thiosulfate is a mechanism involved in the gastrointestinal abnormalities found in EE.
乙基丙二酸脑病 (EE) 是一种严重的遗传性代谢紊乱疾病，会导致患者体内组织中积累大量的硫化氢 (硫化物) 和硫代硫酸盐。尽管 EE 的主要症状是神经方面的，但也常伴有慢性血性腹泻和肠道黏膜异常。鉴于 EE 患者肠道改变的病理生理学机制尚不清楚，且硫化物和硫代硫酸盐是高度反应性的分子，因此研究了这些代谢物对大鼠肠道生物能量产生和传递的影响。结果表明，硫化物会降低肠道中与 NADH 和 FADH 相关的线粒体呼吸，而谷胱甘肽 (GSH) 可避免这种情况，但褪黑素则不行。硫代硫酸盐不会改变呼吸作用。此外，这两种代谢物都会显著降低大鼠肠道中总、细胞质和线粒体肌酸激酶 (CK) 的活性。值得注意的是，只有添加 GSH（而不是褪黑素、阿朴肉桂醇和 Trolox（水溶性维生素 E））才能防止硫化物和硫代硫酸盐引起的总 CK 及其同工酶活性的变化，这表明这些代谢物直接对 CK 结构进行了蛋白质修饰。硫化物进一步增加了肠道中的巯基含量，表明这些基团的氧化还原状态发生了调节。最后，硫化物和硫代硫酸盐降低了 Caco-2 肠道细胞的活力。我们的数据表明，硫化物和硫代硫酸盐引起的生物能量损伤是 EE 患者胃肠道异常的一个机制。
