Sphk2 deletion is involved in structural abnormalities and Th17 response but does not aggravate colon inflammation induced by sub-chronic stress

Sci Rep. 2022 Mar 8;12(1):4073. doi: 10.1038/s41598-022-08011-8.

Abstract

The chronic inflammatory process that characterizes inflammatory bowel diseases (IBD) is mainly driven by T-cell response to microbial and environmental antigens. Psychological stress is a potential trigger of clinical flares of IBD, and sphingosine-1-phosphate (S1P) is involved in T-cell recruitment. Hence, stress impact and the absence of sphingosine kinase 2 (Sphk2), an enzyme of S1P metabolism, were evaluated in the colon of mice after sub-chronic stress exposure. Here, we show that sub-chronic stress increased S1P in the mouse colon, possibly due to a decrease in its degradation enzymes and Sphk2. S1P accumulation could lead to inflammation and immune dysregulation reflected by upregulation of toll-like receptor 4 (TLR4) pathway, inhibition of anti-inflammatory mechanisms, cytokine-expression profile towards a T-helper lymphocyte 17 (Th17) polarization, plasmacytosis, decrease in IgA+ lymphoid lineage cells (CD45+)/B cells/plasmablasts, and increase in IgM+ B cells. Stress also enhanced intestinal permeability. Sphk2 knockout mice presented a cytokine-expression profile towards a boosted Th17 response, lower expression of claudin 3,4,7,8, and structural abnormalities in the colon. Intestinal pathophysiology should consider stress and S1P as modulators of the immune response. S1P-based drugs, including Sphk2 potentiation, represent a promising approach to treat IBD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Colitis* / genetics
  • Colitis* / immunology
  • Colitis* / metabolism
  • Cytokines / immunology
  • Inflammatory Bowel Diseases* / genetics
  • Inflammatory Bowel Diseases* / immunology
  • Inflammatory Bowel Diseases* / metabolism
  • Lysophospholipids / metabolism
  • Mice
  • Mice, Knockout
  • Phosphotransferases (Alcohol Group Acceptor)* / deficiency
  • Phosphotransferases (Alcohol Group Acceptor)* / immunology
  • Phosphotransferases (Alcohol Group Acceptor)* / metabolism
  • Sphingosine / metabolism
  • Stress, Psychological* / immunology
  • Stress, Psychological* / metabolism
  • Th17 Cells* / immunology
  • Th17 Cells* / metabolism

Substances

  • Cytokines
  • Lysophospholipids
  • Phosphotransferases (Alcohol Group Acceptor)
  • sphingosine kinase 2, mouse
  • Sphingosine