Morphofunctional changes underlying intestinal dysmotility in diabetic RIP-I/hIFNβ transgenic mice

Area of Science:

• Gastroenterology
• Diabetology
• Neuroscience

Background:

• Diabetic gastrointestinal dysmotility mechanisms are unclear.
• Enteric neuropathy, interstitial cells of Cajal (ICC) damage, and smooth muscle injury are implicated.
• Understanding these mechanisms is crucial for managing diabetic complications.

Purpose of the Study:

• To investigate morphological and functional changes in intestinal dysmotility in a mouse model of type 1 diabetes.
• To elucidate the role of myenteric neuropathy and neuroplasticity in diabetic enteropathy.

Main Methods:

• Induction of type 1 diabetes in RIP-I/hIFNβ transgenic mice using streptozotocin.
• Assessment of metabolic parameters, intestinal morphology, and transit using conventional microscopy and metabolic cages.
• Evaluation of gastrointestinal contractility, myenteric plexus ultrastructure, and neuronal markers (HuD, nNOS, ChAT, VIP, Substance P) via immunohistochemistry and electron microscopy.

Main Results:

• Diabetic mice exhibited sustained hyperglycemia, polyphagia, polydipsia, and increased fecal output.
• Intestinal remodeling included longer intestines, ileal villi, wider colonic crypts, faster gastric emptying, and intestinal transit.
• Myenteric plexus analysis revealed neuronal degeneration, reduced neuronal numbers (HuD+), altered neurotransmitter expression (decreased nNOS/ChAT, increased VIP/Substance P), but no changes in enteric glia or ICC networks.

Conclusions:

• This streptozotocin-induced diabetic enteropathy model demonstrates accelerated intestinal transit and significant intestinal remodeling.
• The observed myenteric neuropathy and neuroplastic changes are key pathological features in this diabetic model.
• These findings highlight neuroadaptive and neuropathological alterations contributing to gastrointestinal dysmotility in diabetes.