Laboratorio de Farmacología de la Inflamación, Instituto de Farmacología y Morfofisiología, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile; Laboratorio de Inmunometabolismo, Instituto de Farmacología y Morfofisiología, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile; Escuela de Graduados, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile.
Laboratorio de Farmacología de la Inflamación, Instituto de Farmacología y Morfofisiología, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile; Laboratorio de Inmunometabolismo, Instituto de Farmacología y Morfofisiología, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile.
Dev Comp Immunol. 2022 Oct;135:104492. doi: 10.1016/j.dci.2022.104492. Epub 2022 Jul 10.
D-lactic acidosis is a metabolic disease of cattle caused by the digestive overgrowth of bacteria that are highly producers of d-lactate, a metabolite that then reaches and accumulates in the bloodstream. d-lactate is a proinflammatory agent in cattle that induces the formation of extracellular traps (ETs) in polymorphonuclear leucocytes (PMN), although information on PMN metabolic requirements for this response mechanism is insufficient. In the present study, metabolic pathways involved in ET formation induced by d-lactate were studied. We show that d-lactate but not l-lactate induced ET formation in cattle PMN. We analyzed the metabolomic changes induced by d-lactate in bovine PMN using gas chromatography-mass spectrometry (GC-MS). Several metabolic pathways were altered, including glycolysis/gluconeogenesis, amino sugar and nucleotide sugar metabolism, galactose metabolism, starch and sucrose metabolism, fructose and mannose metabolism, and pentose phosphate pathway. d-lactate increased intracellular levels of glucose and glucose-6-phosphate, and increased uptake of the fluorescent glucose analog 2-NBDG, suggesting improved glycolytic activity. In addition, using an enzymatic assay and transmission electron microscopy (TEM), we observed that d-lactate was able to decrease intracellular glycogen levels and the presence of glycogen granules. Relatedly, d-lactate increased the expression of enzymes of glycolysis, gluconeogenesis and glycogen metabolism. In addition, 2DG (a hexokinase inhibitor), 3PO (a 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 inhibitor), MB05032 (inhibitor of fructose-1,6-bisphosphatase) and CP-91149 (inhibitor of glycogen phosphorylase) reduced d-lactate-triggered ETosis. Taken together, these results suggest that d-lactate induces a metabolic rewiring that increases glycolysis, gluconeogenesis and glycogenolysis, all of which are required for d-lactate-induced ET release in cattle PMN.
D-乳酸酸中毒是一种由高度产生 D-乳酸的细菌消化过度生长引起的牛代谢疾病，这种代谢物随后到达并积累在血液中。D-乳酸是牛中的一种促炎剂，它诱导多形核白细胞（PMN）中细胞外陷阱（ET）的形成，尽管关于PMN 代谢需求的信息不足。在本研究中，研究了 D-乳酸诱导 ET 形成的代谢途径。我们表明，D-乳酸而不是 L-乳酸诱导牛 PMN 中 ET 的形成。我们使用气相色谱-质谱联用（GC-MS）分析了 D-乳酸诱导的牛 PMN 中的代谢组变化。几种代谢途径发生改变，包括糖酵解/糖异生、氨基糖和核苷酸糖代谢、半乳糖代谢、淀粉和蔗糖代谢、果糖和甘露糖代谢以及戊糖磷酸途径。D-乳酸增加了牛 PMN 中的葡萄糖和 6-磷酸葡萄糖的细胞内水平，并增加了荧光葡萄糖类似物 2-NBDG 的摄取，这表明糖酵解活性得到改善。此外，通过酶测定和透射电子显微镜（TEM）观察到，D-乳酸能够降低细胞内糖原水平和糖原颗粒的存在。相关地，D-乳酸增加了糖酵解、糖异生和糖原代谢的酶的表达。此外，2DG（己糖激酶抑制剂）、3PO（6-磷酸果糖-2-激酶/果糖-2,6-二磷酸酶 3 抑制剂）、MB05032（果糖-1,6-二磷酸酶抑制剂）和 CP-91149（糖原磷酸化酶抑制剂）减少了 D-乳酸触发的 ET 释放。综上所述，这些结果表明，D-乳酸诱导代谢重排，增加糖酵解、糖异生和糖原分解，这对于牛 PMN 中 D-乳酸诱导的 ET 释放都是必需的。
