CRAC Channel Controls the Differentiation of Pathogenic B Cells in Lupus Nephritis

Xue Li; Qin Zeng; Shuyi Wang; Mengyuan Li; Xionghui Chen; Yuefang Huang; Binfeng Chen; Mianjing Zhou; Yimei Lai; Chaohuan Guo; Siyuan Zhao; Hui Zhang; Niansheng Yang

doi:10.3389/fimmu.2021.779560

CRAC Channel Controls the Differentiation of Pathogenic B Cells in Lupus Nephritis

Front Immunol. 2021 Oct 22:12:779560. doi: 10.3389/fimmu.2021.779560. eCollection 2021.

Authors

Xue Li¹, Qin Zeng¹, Shuyi Wang¹, Mengyuan Li¹, Xionghui Chen², Yuefang Huang³, Binfeng Chen¹, Mianjing Zhou¹, Yimei Lai¹, Chaohuan Guo¹, Siyuan Zhao¹, Hui Zhang^{1

4}, Niansheng Yang¹

Affiliations

¹ Department of Rheumatology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
² Department of Nephrology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
³ Department of Pediatrics, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
⁴ Institute of Precision Medicine, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.

Abstract

Store-operated Ca²⁺ release-activated Ca²⁺ (CRAC) channel is the main Ca²⁺ influx pathway in lymphocytes and is essential for immune response. Lupus nephritis (LN) is an autoimmune disease characterized by the production of autoantibodies due to widespread loss of immune tolerance. In this study, RNA-seq analysis revealed that calcium transmembrane transport and calcium channel activity were enhanced in naive B cells from patients with LN. The increased expression of ORAI1, ORAI2, and STIM2 in naive B cells from patients with LN was confirmed by flow cytometry and Western blot, implying a role of CRAC channel in B-cell dysregulation in LN. For in vitro study, CRAC channel inhibition by YM-58483 or downregulation by ORAI1-specific small-interfering RNA (siRNA) decreased the phosphorylation of Ca²⁺/calmodulin-dependent protein kinase2 (CaMK2) and suppressed Blimp-1 expression in primary human B cells, resulting in decreased B-cell differentiation and immunoglobulin G (IgG) production. B cells treated with CaMK2-specific siRNA showed defects in plasma cell differentiation and IgG production. For in vivo study, YM-58483 not only ameliorated the progression of LN but also prevented the development of LN. MRL/lpr lupus mice treated with YM-58483 showed lower percentage of plasma cells in the spleen and reduced concentration of anti-double-stranded DNA antibodies in the sera significantly. Importantly, mice treated with YM-58483 showed decreased immune deposition in the glomeruli and alleviated kidney damage, which was further confirmed in NZM2328 lupus mice. Collectively, CRAC channel controlled the differentiation of pathogenic B cells and promoted the progression of LN. This study provides insights into the pathogenic mechanisms of LN and that CRAC channel could serve as a potential therapeutic target for LN.

Keywords: B-cell differentiation; Ca2+ release-activated Ca2+ channel; CaMK2; lupus nephritis; store-operated Ca2+ entry.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
B-Lymphocytes / immunology*
Calcium Release Activated Calcium Channels / immunology*
Cell Differentiation / immunology*
Humans
Lupus Nephritis / immunology*
Mice
Mice, Inbred MRL lpr

Substances

Calcium Release Activated Calcium Channels