Targeting the Calcium-Sensing Receptor in Chemically Induced Medium-Grade Colitis in Female BALB/C Mice

Area of Science:

• Gastroenterology
• Pharmacology
• Immunology

Background:

• The extracellular calcium-sensing receptor (CaSR) is a potential therapeutic target for inflammatory bowel disease.
• Previous studies indicated CaSR inhibition with NPS 2143 ameliorated severe colitis symptoms in mice.
• The impact of CaSR inhibition on medium-grade colitis remained unclear.

Purpose of the Study:

• To investigate the efficacy of CaSR inhibition using NPS 2143 in preventing and treating medium-grade colitis in a mouse model.
• To determine if the anti-inflammatory effects observed in severe colitis are also present in a less severe form of the disease.

Main Methods:

• Female BALB/c mice were administered NPS 2143 or vehicle before inducing colitis with 2.5% DSS.
• Colonic tissues and plasma were analyzed for histological scores, mucin content, cell proliferation (Ki67), and immune cell infiltration (CD3, CD20).
• Gene expression of inflammatory markers (e.g., COX2, IL-22) was quantified using RT-qPCR.

Main Results:

• NPS 2143 treatment did not alter clinical symptom scores but significantly reduced colon ulceration and increased colon length.
• The expression of COX2 in the proximal colon and IL-22 in the distal colon was significantly reduced by NPS 2143.
• A significant decrease in lymph node cell proliferation was observed, while epithelial cell proliferation remained unchanged.

Conclusions:

• CaSR inhibition with NPS 2143 demonstrates anti-inflammatory effects in medium-grade colitis, albeit milder than in severe colitis.
• These findings suggest that the therapeutic potential of CaSR inhibition for colitis is dependent on disease severity.
• CaSR inhibition warrants further investigation as a potential treatment strategy for inflammatory bowel disease.