P2Y₆ Receptors Regulate CXCL10 Expression and Secretion in Mouse Intestinal Epithelial Cells

Area of Science:

• Immunology
• Cell Biology
• Gastroenterology

Background:

• Extracellular nucleotides act as signaling molecules.
• P2Y6 receptors are expressed in intestinal epithelial cells (IECs).
• Chemokines like CXCL10 play roles in inflammation and immunity.

Purpose of the Study:

• To investigate the role of extracellular nucleotides and P2Y6 receptors in chemokine expression and secretion by murine primary IECs.
• To elucidate the specific P2 receptors involved in regulating CXCL10 expression.
• To understand the implications for IEC homeostasis.

Main Methods:

• Quantitative reverse transcription polymerase chain reaction (qRT-PCR) for gene expression analysis.
• Use of P2Y6-deficient (P2ry6-/-) and wild-type (WT) mice models.
• Stimulation of IECs with various agonists (UDP, poly(I:C), LPS, FGF2) and antagonists.
• Measurement of chemokine secretion and assessment of macrophage chemotaxis.

Main Results:

• P2Y6 was the dominant nucleotide receptor in mouse IECs, and its ligand UDP induced CXCL10 expression and secretion.
• In P2Y6-/- IECs, other P2 receptors (P2Y1, P2Y2, P2X4) and TLR agonists (poly(I:C), LPS) more prominently increased CXCL10 expression and secretion compared to WT IECs.
• CXCL10 induction by poly(I:C) was inhibited by P2 antagonists, apyrase, and specific antagonists for P2Y1, P2Y2, P2Y6 (in WT), and P2X4.
• Supernatants from treated IECs induced macrophage chemotaxis, correlating with CXCL10 levels.
• FGF2 also induced higher MMP9 mRNA expression in P2Y6-/- IECs than in WT IECs.

Conclusions:

• Extracellular nucleotides, acting through P2Y6 and other P2 receptors, regulate CXCL10 expression and secretion in IECs.
• The P2Y6 receptor modulates chemokine secretion, influencing IEC homeostasis.
• These findings highlight the complex interplay of nucleotide signaling in intestinal immunity and epithelial cell function.