Symmetrically substituted dichlorophenes inhibit N-acyl-phosphatidylethanolamine phospholipase D

Area of Science:

• Biochemistry
• Enzymology
• Pharmacology

Background:

• N-Acyl-phosphatidylethanolamine phospholipase D (NAPE-PLD) is key in N-acyl-ethanolamide biosynthesis.
• NAPE-PLD dysfunction is implicated in obesity and inflammation.
• Lack of selective NAPE-PLD inhibitors hinders research.

Purpose of the Study:

• To discover novel, potent, and selective inhibitors of NAPE-PLD.
• To explore the structure-activity relationships of NAPE-PLD inhibitors.
• To validate inhibitor efficacy in cellular models.

Main Methods:

• Screening of bile acids and the Spectrum Collection using a quenched fluorescent NAPE analog (PED-A1) and recombinant mouse Nape-pld.
• Identification and characterization of NAPE-PLD inhibitors.
• Structure-activity relationship studies with substituted dichlorophenes.
• Assays for selectivity against other lipase activities and cellular inhibition in HEK293 cells.

Main Results:

• Several bile acids showed moderate Nape-pld inhibition.
• Hexachlorophene and bithionol identified as potent Nape-pld inhibitors (IC50 ≈ 2 μm).
• Structure-activity relationships pinpointed key inhibitory moieties.
• Hexachlorophene and bithionol demonstrated high selectivity for NAPE-PLD over other lipases and inhibited NAPE-PLD in cultured cells.

Conclusions:

• Symmetrically substituted dichlorophenes, like hexachlorophene and bithionol, are potent NAPE-PLD inhibitors.
• These compounds exhibit significant selectivity for NAPE-PLD compared to other lipases.
• The findings provide valuable tools for studying N-acyl-ethanolamide pathways and potential therapeutic targets.