Characterization of intestinal and pancreatic dysfunction in VPAC1-null mutant mouse

Area of Science:

• Developmental biology
• Endocrinology
• Gastroenterology

Background:

• Vasoactive intestinal peptide receptor type 1 (VPAC1) plays a role in various physiological processes.
• The specific function of VPAC1 during embryonic and neonatal development is not fully understood.

Purpose of the Study:

• To investigate the impact of VPAC1 gene deletion on the development and function of the intestines and pancreas.
• To elucidate the role of VPAC1 in glucose homeostasis and overall growth.

Main Methods:

• Generation and analysis of VPAC1-null mutant mice.
• Monitoring of growth, development, and glucose homeostasis in mutant and wild-type littermates.
• Histological examination of intestinal and pancreatic tissues.
• Analysis of VPAC1 expression patterns during embryonic development using transgenic mice.

Main Results:

• Homozygous VPAC1 deletion led to high mortality rates due to failure to thrive, intestinal obstruction, and hypoglycemia.
• Histological analysis revealed disorganized intestinal epithelial cell proliferation, mucus deposition, and bowel wall thickening.
• VPAC1-null mice exhibited dysmorphic pancreatic islets and impaired glucose homeostasis, with exaggerated hypoglycemia following glucose or insulin challenges.
• VPAC1 expression was detected in embryonic intestinal epithelial and pancreatic endocrine cells.

Conclusions:

• VPAC1 is essential for normal embryonic and neonatal development of the intestines and endocrine pancreas.
• The absence of VPAC1 disrupts intestinal structure and function, leading to severe metabolic and growth deficits.
• These findings highlight VPAC1 as a critical factor in maintaining glucose homeostasis and overall development.