In EHEC O157:H7 infection, hemolytic uremic syndrome (HUS) develops due to Shiga toxin binding to endothelial Gb3 receptors. The population of renal endothelial cells that expresses the HIGHEST density of Gb3 receptors explaining why kidneys are preferentially affected is:
- A Peritubular capillary endothelial cells
- B Afferent arteriolar smooth muscle cells
- C Glomerular endothelial cells ✓
- D Mesangial cells
Explanation
Glomerular endothelial cells express the highest density of globotriaosylceramide (Gb3, the Shiga toxin receptor) compared to other renal cell types; Stx2 (more potent than Stx1) binds Gb3 on glomerular endothelium, undergoes retrograde transport to the ER, and inhibits protein synthesis via N-glycosidase cleavage of 28S rRNA; endothelial apoptosis and activation cause microthrombi, glomerular occlusion, and ARF. Peritubular capillaries also express Gb3 but at lower density. Arteriolar smooth muscle and mesangial cells have less Gb3 than glomerular endothelium.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.