Exosomal MiR-4261 mediates calcium overload in RBCs by downregulating the expression of ATP2B4 in multiple myeloma

Sicheng Bian; Xialin Zhang; Leilei Lin; Lili Sun; Zhibo Guo; Jie Pan; Jiangxia Cui; Hanbing Yao; Jing Xu; Zhuanghui Hao; Yuzhu Wang; Liguo Tong; Xingpeng Bu; Desheng Kong; Nianjiao Liu; Yinghua Li

doi:10.3389/fonc.2022.978755

Exosomal MiR-4261 mediates calcium overload in RBCs by downregulating the expression of ATP2B4 in multiple myeloma

Front Oncol. 2022 Aug 26:12:978755. doi: 10.3389/fonc.2022.978755. eCollection 2022.

Authors

Sicheng Bian^{1

2}, Xialin Zhang³, Leilei Lin⁴, Lili Sun^{1

2}, Zhibo Guo^{1

2}, Jie Pan⁵, Jiangxia Cui⁶, Hanbing Yao⁶, Jing Xu⁷, Zhuanghui Hao⁷, Yuzhu Wang^{1

2}, Liguo Tong⁸, Xingpeng Bu⁹, Desheng Kong¹, Nianjiao Liu¹, Yinghua Li^{1

2}

Affiliations

¹ Key Laboratory of Cell Transplantation of National Health Commission, Heilongjiang Key Laboratory of Blood and Hematopoietic System, Harbin Medical University, Harbin, China.
² Department of Hematology, The First Affiliated Hospital, Harbin Medical University, Harbin, China.
³ Department of Hematology, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, China.
⁴ Department of Hematology, Affiliated Yantai Yuhuangding Hospital, Qingdao University, Yantai, China.
⁵ Department of Pathology, Stanford University School of Medicine, Palo Alto, CA, United States.
⁶ Department of Hematology, Xi'an International Medical Center Hospital, Xi'an, China.
⁷ Institute of Hematology, The Second Hospital of Shanxi Medical University, Taiyuan, China.
⁸ Central Laboratory, Shanxi Academy of Traditional Chinese Medicine, Taiyuan, China.
⁹ Department of Geriatrics, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Taiyuan, China.

Abstract

Background: Hypercalcemia induced by multiple myeloma (MM) affects the biological functions of excitable and non-excitable cells. However, red blood cells (RBCs) regulatory effect on calcium in hypercalcemia is still not fully understood.

Methods: A total of 113 patients with MM osteolytic lesions were studied retrospectively. Flow cytometry and atomic absorption spectroscopy were used to detect calcium content. Immunofluorescence and Western blotting were used to investigate protein expression. GEO and miRNA databases were used to screen miRNAs. Exosomal miR-4261 migration was investigated by Transwell assay. Dual-luciferase assays confirmed the targeting relationship between miR-4261 and ATP2B4. An RBC oxidative stress model was constructed, and Omega-Agatoxin IVA was used to study the role of plasma membrane Ca²⁺-ATPase 4 (PMCA4) in RBCs.

Results: The results showed that MM RBCs had calcium overload, and serum calcium levels increased as the number of RBCs decreased. The expression of PMCA4 in MM RBCs was significantly lower than in normal RBCs. The exosomal miR-4261 produced by MM cells could be transferred to RBCs to downregulate the expression of ATP2B4.

Conclusions: Studies have confirmed that RBCs experience calcium overload in MM with osteolytic lesions, which is related to the downregulation of ATP2B4 by MM exosomal miR-4261.

Keywords: ATP2B4; RBC; calcium overload; miR-4261; multiple myeloma.