Bach2 regulates aberrant activation of B cell in systemic lupus erythematosus and can be negatively regulated by BCR-ABL/PI3K

  • Exp Cell Res. 2018 Apr 1;365(1):138-144. doi: 10.1016/j.yexcr.2018.02.034.
Zhengwei Zhu  1 Chao Yang  1 Leilei Wen  1 Lu Liu  1 Xianbo Zuo  1 Fusheng Zhou  1 Jinping Gao  1 Xiaodong Zheng  1 Yinjuan Shi  1 Caihong Zhu  1 Bo Liang  1 Xianyong Yin  1 Wenjun Wang  1 Hui Cheng  1 Songke Shen  1 Xianfa Tang  1 Huayang Tang  1 Liangdan Sun  1 Anping Zhang  1 Sen Yang  1 Yong Cui  2 Xuejun Zhang  1 Yujun Sheng  3
Affiliations
  • 1. Institute of Dermatology and Department of Dermatology, the First Affiliated Hospital, Anhui Medical University, No. 81 Meishan Road, Hefei, Anhui 230032, China; Key Laboratory of Dermatology, Anhui Medical University, Ministry of Education, Hefei, Anhui 230032, China.
  • 2. Department of Dermatology, China-Japan Friendship Hospital, East Street Cherry Park, Chaoyang District, Beijing 100029, China.
  • 3. Institute of Dermatology and Department of Dermatology, the First Affiliated Hospital, Anhui Medical University, No. 81 Meishan Road, Hefei, Anhui 230032, China; Key Laboratory of Dermatology, Anhui Medical University, Ministry of Education, Hefei, Anhui 230032, China. Electronic address: [email protected].
Abstract

Objective: This study was aimed to explore the effect of Bach2 on B cells in systemic lupus erythematosus (SLE), as well as the underlying mechanisms.

Methods: Expression of Bach2, phosphorylated-Bach2 (p-Bach2), Akt, p-Akt and Bcr-Abl (p210) in B cells isolated from SLE patients and the healthy persons were assessed by Western blot. Immunofluorescence staining was performed to assess the localization of Bach2 in B cells. Enzyme-linked immunosorbent assay (ELISA) was employed to detect IgG produced by B cells. Cell counting kit-8 (CCK-8) and Annexin-V FITC/PI double staining assay were adopted to evaluate cell proliferation and Apoptosis in B cells, respectively.

Results: Compared to the healthy controls, Bach2, p-Akt and p210 were significantly decreased, while nuclear translocation of Bach2, IgG, CD40 and CD86 obviously up-regulated in B cells from SLE patients. Bach2 significantly inhibited the proliferation, promoted Apoptosis of B cells from SLE patients, whereas Bcr-Abl dramatically reversed cell changes induced by Bach2. Besides, Bcr-Abl also inhibited nuclear translocation of Bach2 in B cells from SLE patients. Further, LY294002 treatment had no effect on decreased expression of Bach2 induced by Bcr-Abl, but significantly eliminated BCR-ABL-induced phosphorylation of Bach2 and restored reduced nuclear translocation of Bach2 induced by Bcr-Abl in B cells from SLE.

Conclusions: Bach2 may play a suppressive role in B cells from SLE, and Bcr-Abl may inhibit the nuclear translocation of Bach2 via serine phosphorylation through the PI3K pathway.

Keywords
B cells; BCR-ABL; Bach2; PI3K; Systemic lupus erythematosus (SLE).
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