title: Aldose Reductase Regulates Microglia/Macrophages Polarization Through the cAMP Response Element-Binding Protein After Spinal Cord Injury in Mice.
abstract: Inflammatory reactions are the most critical pathological processes occurring after spinal cord injury (SCI). Activated microglia/macrophages have either detrimental or beneficial effects on neural regeneration based on their functional polarized M1/M2 subsets. However, the mechanism of microglia/macrophage polarization to M1/M2 at the injured spinal cord environment remains unknown. In this study, wild-type (WT) or aldose reductase (AR)-knockout (KO) mice were subjected to SCI by a spinal crush injury model. The expression pattern of AR, behavior tests for locomotor activity, and lesion size were assessed at between 4 h and 28 days after SCI. We found that the expression of AR is upregulated in microglia/macrophages after SCI in WT mice. In AR KO mice, SCI led to smaller injury lesion areas compared to WT. AR deficiency-induced microglia/macrophages induce the M2 rather than the M1 response and promote locomotion recovery after SCI in mice. In the in vitro experiments, microglia cell lines (N9 or BV2) were treated with the AR inhibitor (ARI) fidarestat. AR inhibition caused 4-hydroxynonenal (HNE) accumulation, which induced the phosphorylation of the cAMP response element-binding protein (CREB) to promote Arg1 expression. KG501, the specific inhibitor of phosphorylated CREB, could cancel the upregulation of Arg1 by ARI or HNE stimulation. Our results suggest that AR works as a switch which can regulate microglia by polarizing cells to either the M1 or the M2 phenotype under M1 stimulation based on its states of activity. We suggest that inhibiting AR may be a promising therapeutic method for SCI in the future.
authors.affiliation: Department of Neurobiology, The Fourth Military Medical University, 169 West Changle Road, Xi'an, 710032, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Neurobiology, The Fourth Military Medical University, 169 West Changle Road, Xi'an, 710032, China.
authors.forename: Ganlan
authors.initials: G
authors.lastname: Bian
authors.affiliation: Department of Neurobiology, The Fourth Military Medical University, 169 West Changle Road, Xi'an, 710032, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Chen
authors.affiliation: Department of Neurobiology, The Fourth Military Medical University, 169 West Changle Road, Xi'an, 710032, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Neurobiology, The Fourth Military Medical University, 169 West Changle Road, Xi'an, 710032, China.
authors.forename: Caiyong
authors.initials: C
authors.lastname: Yu
authors.affiliation: Department of Neurobiology, The Fourth Military Medical University, 169 West Changle Road, Xi'an, 710032, China.
authors.forename: Fangfang
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Neurobiology, The Fourth Military Medical University, 169 West Changle Road, Xi'an, 710032, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Xue
authors.affiliation: Department of Anatomy, The University of Hong Kong, HKSAR, China.
authors.forename: Sookja K
authors.initials: SK
authors.lastname: Chung
authors.affiliation: Cardiff Institute of Tissue Engineering & Repair, School of Dentistry, Cardiff University, Cardiff CF14 4XY, UK.
authors.forename: Bing
authors.initials: B
authors.lastname: Song
authors.affiliation: Department of Neurobiology, The Fourth Military Medical University, 169 West Changle Road, Xi'an, 710032, China. jugong@fmmu.edu.cn.
authors.forename: Gong
authors.initials: G
authors.lastname: Ju
authors.affiliation: Department of Neurobiology, The Fourth Military Medical University, 169 West Changle Road, Xi'an, 710032, China. jwangfm@fmmu.edu.cn.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
mesh_terms: D000449:Aldehyde Reductase / Q000096:biosynthesis* / Q000172:deficiency; D000818:Animals; D002460:Cell Line; D016764:Cell Polarity / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D017628:Microglia / Q000187:drug effects / Q000378:metabolism*; D013119:Spinal Cord Injuries / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: C492004:Creb1 protein, mouse; D017362:Cyclic AMP Response Element-Binding Protein; D014409:Tumor Necrosis Factor-alpha; D000449:Aldehyde Reductase
keywords: Aldose reductase; Locomotor recovery; M1/M2 polarization; Microglia/macrophages; Spinal cord injury; cAMP response element-binding protein