Accelerated diabetic glomerulopathy in galectin-3/AGE receptor 3 knockout mice

Area of Science:

• Nephrology
• Immunology
• Endocrinology

Background:

• Advanced glycation end products (AGEs) are implicated in diabetic complications.
• The in vivo function of various AGE-binding molecules as receptors remains unclear.
• Galectin-3 is a lectin with known (anti)adhesive and growth-regulating properties.

Purpose of the Study:

• To investigate galectin-3's role as an AGE receptor.
• To determine galectin-3's contribution to diabetic glomerular disease development.
• To elucidate the in vivo AGE receptor pathway regulated by galectin-3.

Main Methods:

• Utilized a galectin-3 knockout mouse model.
• Induced diabetes using streptozotocin in knockout and wild-type mice.
• Analyzed proteinuria, extracellular matrix gene expression, mesangial expansion, and AGE accumulation at 4 months post-induction.

Main Results:

• Galectin-3 deficient mice exhibited accelerated glomerulopathy compared to wild-type controls, despite similar metabolic derangement.
• Increased renal/glomerular AGE accumulation was observed in knockout mice, indicating impaired AGE clearance.
• Downregulation of AGE removal receptors (e.g., macrophage scavenger receptor A) and upregulation of cell activation receptors (e.g., RAGE) were noted in galectin-3 deficient mice.

Conclusions:

• The galectin-3-regulated AGE receptor pathway is functional in vivo.
• Galectin-3 plays a protective role against AGE-induced tissue injury in the kidney.
• The galectin-3 pathway offers protection distinct from the RAGE pathway in diabetic nephropathy.