Leptin mediates Clostridium difficile toxin A-induced enteritis in mice.

Area of Science:

• Gastroenterology
• Endocrinology
• Immunology

Background:

• Leptin regulates energy balance and the hypothalamic-pituitary-adrenal axis.
• The role of leptin in enterotoxin-induced diarrhea and inflammation is not fully understood.
• Clostridium difficile toxin A causes antibiotic-related colitis.

Purpose of the Study:

• To investigate the role of leptin in inflammatory diarrhea induced by Clostridium difficile toxin A.
• To determine the mechanisms by which leptin affects intestinal inflammation.

Main Methods:

• Administered toxin A or buffer to ileal loops of leptin-deficient (ob/ob), leptin-resistant (db/db), and wild-type mice.
• Measured enterotoxic responses, circulating leptin and corticosterone levels, and mucosal Ob-Rb expression.
• Performed adrenalectomy experiments to assess the role of corticosteroids.

Main Results:

• Toxin A increased circulating leptin and corticosterone levels and mucosal Ob-Rb expression in wild-type mice.
• ob/ob and db/db mice showed partial protection against toxin A-induced intestinal secretion and inflammation.
• Leptin administration reversed protection in ob/ob mice but not db/db mice.
• Diminished intestinal response in db/db mice was partly attributed to increased corticosteroids.

Conclusions:

• Leptin plays a significant role in regulating the severity of enterotoxin-mediated intestinal secretion and inflammation.
• Leptin acts through both corticosteroid-dependent and -independent mechanisms to modulate intestinal inflammation.