Anemia Severity in β-Thalassemia Correlates with Elevated Levels of microRNA-125b in Activated Phagocytic Monocytes

Abstract

β-Thalassemia (β-thal), is an inherited blood disorder caused by reduced or absent synthesis of β-globin chains leading to imbalance of globin chain synthesis. The clearance of β-thalassemic abnormal red blood cells (RBCs) that result from excessive unbound α-globin is mainly achieved by activated monocytes. The phagocytic activity of β-thal monocytes significantly increases when co-cultured with normal and β-thal RBC individuals compare to that of normal monocytes co-cultured with normal RBCs. The present study indicates that microRNA (miR) plays a role in monocyte activation. In this study, we identified the higher miR-125b expression in CD14 marker-positive monocytic cells of β-thal patients. Moreover, miR-125b expression levels positively correlate with the phagocytic activity of monocytes. Remarkably, miR-125b expression levels are negatively correlated with RBC count, hemoglobin (Hb) and hematocrit [or packed cell volume (PCV)], which are the indices for the severity of anemia. From these findings, our future studies will be to prove the hypothesis that miR-125b expression in activated monocytes may be a genetic modifier related to the severity of anemia in β-thal patients.

Keywords:

• Activated monocyte
• anemia severity
• β-thalassemia (β-thal)
• microRNA-125b (miR-125b)
• phagocytosis

Acknowledgments

We thank the Department of Pathology, Faculty of Medicine, and Thalassemia Research Center, Institute of Molecular Biosciences, Mahidol University, Mahidol, Thailand. S. Kuno contributed to the molecular study, interpretation of the data and the drafted manuscript; T. Penglong contributed to the study design, interpretation of the data and editing of the manuscript; K. Srinoun contributed to the study design, interpretation of the data, drafting and editing of the manuscript. The final version of the article was read and approved by all authors.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

This study was supported by the ‘budget revenue’ grant [MED600572S] of Prince of Songkla University and the Faculty of Medical Technology, Prince of Songkla University, Songkla, Thailand. S. Kuno was supported by a scholarship from the Department of Biomedical Sciences, Faculty of Medicine, Prince of Songkla University, Songkla, Thailand.