Enzymatic Changes in Red Blood Cells of Diamond-Blackfan Anemia

Enzymatic Changes in Red Blood Cells of Diamond-Blackfan Anemia

Taiju Utsugisawa,¹ Toshitaka Uchiyama,² Tsutomu Toki,³ Keiko Shimojima-Yamamoto,^1,2 Shouichi Ohga,⁴ Etsuro Ito³ and Hitoshi Kanno^1,2

¹Department of Transfusion Medicine and Cell Processing, Faculty of Medicine, Tokyo Women’s Medical University, Tokyo, Japan
²Institute of Medical Genetics, Tokyo Women’s Medical University, Tokyo, Japan
³Department of Pediatrics, Hirosaki University, School of Medicine, Hirosaki, Aomori, Japan
⁴Department of Pediatrics, Kyushu University, School of Medicine, Fukuoka, Fukuoka, Japan

Diamond-Blackfan anemia is a congenital bone marrow failure syndrome characterized by red blood cell (RBC) aplasia with varied malformations in infants. Elevated activity of adenosine deaminase (ADA) has been considered as a useful biomarker of Diamond-Blackfan anemia, and ADA assay has been shown to be more sensitive than genetic diagnosis. Approximately, 80% of the examined patients showed elevated ADA activity, whereas genetic tests of ribosome subunit genes identified mutations in approximately 60% of the patients. We previously reported that reduced glutathione (GSH) levels in RBCs may serve as a biomarker of Diamond-Blackfan anemia. In this study, to confirm the universality of our data, we extended the analysis to seven RBC enzymes and GSH of 14 patients with Diamond-Blackfan anemia and performed a cross-analysis study using enzyme activity assay and recently reported proteome data. Statistical analysis revealed that both data exhibited high similarity, upregulation in the hexokinase and pentose-phosphate pathway, and downregulation in glycolytic enzymes such as phosphofructokinase and pyruvate kinase, in the RBCs obtained from the subjects with Diamond-Blackfan anemia. The only discrepancy between enzyme activity and proteome data was observed in glucose-6-phosphate dehydrogenase (G6PD), as increased G6PD activity showed no relation with the significant elevation in protein levels. These results suggest that our enzymatic activity data of Diamond-Blackfan anemia are universal and that the enzymatic activation of G6PD via a hitherto-unveiled mechanism is another metabolic feature of RBCs of Diamond-Blackfan anemia.

Keywords —— Diamond-Blackfan anemia; glycolysis; oxidative stress; proteome; red blood cell enzymes

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Tohoku J. Exp. Med 2021, 255, 49-55.

Correspondence: Hitoshi Kanno, Department of Transfusion Medicine and Cell Processing, Faculty of Medicine, Tokyo Women’s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.

e-mail: kanno.hitoshi@twmu.ac.jp