α-Ketoglutarate plays an inflammatory inhibitory role by regulating scavenger receptor class a expression through N6-methyladenine methylation during sepsis

Eur J Immunol. 2024 Sep;54(9):e2350655. doi: 10.1002/eji.202350655. Epub 2024 Jul 7.

Abstract

Sepsis arises from an uncontrolled inflammatory response triggered by infection or stress, accompanied by alteration in cellular energy metabolism, and a strong correlation exists between these factors. Alpha-ketoglutarate (α-KG), an intermediate product of the TCA cycle, has the potential to modulate the inflammatory response and is considered a crucial link between energy metabolism and inflammation. The scavenger receptor (SR-A5), a significant pattern recognition receptor, assumes a vital function in anti-inflammatory reactions. In the current investigation, we have successfully illustrated the ability of α-KG to mitigate inflammatory factors in the serum of septic mice and ameliorate tissue damage. Additionally, α-KG has been shown to modulate metabolic reprogramming and macrophage polarization. Moreover, our findings indicate that the regulatory influence of α-KG on sepsis is mediated through SR-A5. We also elucidated the mechanism by which α-KG regulates SR-A5 expression and found that α-KG reduced the N6-methyladenosine level of macrophages by up-regulating the m6A demethylase ALKBH5. α-KG plays a crucial role in inhibiting inflammation by regulating SR-A5 expression through m6A demethylation during sepsis. The outcomes of this research provide valuable insights into the relationship between energy metabolism and inflammation regulation, as well as the underlying molecular regulatory mechanism.

Keywords: SR‐A5; Sepsis; m6A methylation; α‐Ketoglutarate.

MeSH terms

  • Adenine / analogs & derivatives
  • Adenine / pharmacology
  • Adenosine / analogs & derivatives
  • Adenosine / metabolism
  • AlkB Homolog 5, RNA Demethylase / genetics
  • AlkB Homolog 5, RNA Demethylase / metabolism
  • Animals
  • Disease Models, Animal
  • Gene Expression Regulation
  • Humans
  • Inflammation* / immunology
  • Inflammation* / metabolism
  • Ketoglutaric Acids* / metabolism
  • Macrophages* / immunology
  • Macrophages* / metabolism
  • Male
  • Methylation
  • Mice
  • Mice, Inbred C57BL
  • Receptor, Adenosine A2A
  • Scavenger Receptors, Class A* / genetics
  • Scavenger Receptors, Class A* / metabolism
  • Sepsis* / immunology
  • Sepsis* / metabolism

Substances

  • Ketoglutaric Acids
  • Scavenger Receptors, Class A
  • AlkB Homolog 5, RNA Demethylase
  • Adenosine
  • Adenine
  • Adora2a protein, mouse
  • Receptor, Adenosine A2A