1. Academic Validation
  2. The effect of dipeptidyl peptidase IV on disease-associated microglia phenotypic transformation in epilepsy

The effect of dipeptidyl peptidase IV on disease-associated microglia phenotypic transformation in epilepsy

  • J Neuroinflammation. 2021 May 11;18(1):112. doi: 10.1186/s12974-021-02133-y.
Zhicheng Zheng 1 Peiyu Liang 1 Baohua Hou 2 Xin Lu 1 Qianwen Ma 1 Xiaomin Yu 1 Song Han 1 Biwen Peng 3 Taoxiang Chen 3 Wanhong Liu 4 Jun Yin 5 Xiaohua He 6
Affiliations

Affiliations

  • 1 Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China.
  • 2 Medical College, Henan Polytechnic University, Jiaozuo, China.
  • 3 Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, China.
  • 4 Hubei Province Key Laboratory of Allergy and Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.
  • 5 Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China. [email protected].
  • 6 Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China. [email protected].
Abstract

Background: Accumulating evidence suggests that disease-associated microglia (DAM), a recently discovered subset of microglia, plays a protective role in neurological diseases. Targeting DAM phenotypic transformation may provide new therapeutic options. However, the relationship between DAM and epilepsy remains unknown.

Methods: Analysis of public RNA-sequencing data revealed predisposing factors (such as Dipeptidyl Peptidase IV; DPP4) for epilepsy related to DAM conversion. Anti-epileptic effect was assessed by electroencephalogram recordings and immunohistochemistry in a kainic acid (KA)-induced mouse model of epilepsy. The phenotype, morphology and function of microglia were assessed by qPCR, western blotting and microscopic imaging.

Results: Our results demonstrated that DPP4 participated in DAM conversion and epilepsy. The treatment of sitagliptin (a DPP4 inhibitor) attenuated KA-induced epilepsy and promoted the expression of DAM markers (Itgax and Axl) in both mouse epilepsy model in vivo and microglial inflammatory model in vitro. With sitagliptin treatment, microglial cells did not display an inflammatory activation state (enlarged cell bodies). Furthermore, these microglia exhibited complicated intersections, longer processes and wider coverage of parenchyma. In addition, sitagliptin reduced the activation of NF-κB signaling pathway and inhibited the expression of iNOS, IL-1β, IL-6 and the proinflammatory DAM subset gene CD44.

Conclusion: The present results highlight that the DPP4 inhibitor sitagliptin can attenuate epilepsy and promote DAM phenotypic transformation. These DAM exhibit unique morphological features, greater migration ability and better surveillance capability. The possible underlying mechanism is that sitagliptin can reduce the activation of NF-κB signaling pathway and suppress the inflammatory response mediated by microglia. Thus, we propose DPP4 may act as an attractive direction for DAM research and a potential therapeutic target for epilepsy.

Keywords

Dipeptidyl peptidase IV; Disease-associated microglia; Epilepsy; Microglia.

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