Department of Neurology, Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120 Halle (Saale), Germany.
Int J Mol Sci. 2019 Mar 20;20(6):1400. doi: 10.3390/ijms20061400.
Fibroblast growth factor 21 (FGF-21) is known to be a biomarker for mitochondrial disorders. An upregulation of FGF-21 in serum and muscle of carnitine palmitoyltransferase I (CPT I) and carnitine palmitoyltransferase II (CPT II) knock-out mice has been reported. In human CPT II deficiency, enzyme activity and protein content are normal, but the enzyme is abnormally regulated by malonyl-CoA and is abnormally thermolabile. Citrate synthase (CS) activity is increased in patients with CPT II deficiency. This may indicate a compensatory response to an impaired function of CPT II. In this study, FGF-21 serum levels in patients with CPT II deficiency during attack free intervals and in healthy controls were measured by enzyme linked immunosorbent assay (ELISA). The data showed no significant difference between FGF-21 concentration in the serum of patients with CPT II deficiency and that in the healthy controls. The results of the present work support the hypothesis that in muscle CPT II deficiency, in contrast to the mouse knockout model, mitochondrial fatty acid utilization is not persistently reduced. Thus, FGF-21 does not seem to be a useful biomarker in the diagnosis of CPT II deficiency.
成纤维细胞生长因子 21（FGF-21）已知是线粒体疾病的生物标志物。据报道，肉毒碱棕榈酰基转移酶 I（CPT I）和肉毒碱棕榈酰基转移酶 II（CPT II）敲除小鼠的血清和肌肉中 FGF-21 上调。在人类 CPT II 缺乏症中，酶活性和蛋白含量正常，但酶被丙二酰辅酶 A 异常调节，且异常热敏。柠檬酸合酶（CS）活性在 CPT II 缺乏症患者中增加。这可能表明对 CPT II 功能受损的代偿反应。在这项研究中，通过酶联免疫吸附测定（ELISA）测量了 CPT II 缺乏症患者在无攻击间期和健康对照组中的 FGF-21 血清水平。数据显示，CPT II 缺乏症患者血清中的 FGF-21 浓度与健康对照组之间没有显著差异。本工作的结果支持这样的假设，即在肌肉 CPT II 缺乏症中，与小鼠敲除模型相反，线粒体脂肪酸利用并未持续降低。因此，FGF-21 似乎不是 CPT II 缺乏症诊断的有用生物标志物。
