High Levels of Dietary Lard or Sucrose May Aggravate Lysosomal Renal Injury in Non-Obese, Streptozotocin-Injected CD-1 Mice Provided Isocaloric Diets

Summary Daily fat and sugar intake has increased in Japan, while total energy intake has decreased. However, the number of type 2 diabetes mellitus patients has increased, and this often causes renal injury characterized by autophagic vacuoles. Although many studies with comparisons of high fat or sugar versus a normal macronutrient balanced diet have been reported, there are few studies that equalized calorie intake and body weights. In the current study, AIN93M diets (CONT group) with matching energy content with lard derived high saturated fat (LARD group), soybean oil derived unsaturated fat (SOY OIL group) and sucrose (SUCROSE group) were provided to compare their effects on renal morphology in streptozotocin-injected CD-1 mice without causing obesity. The number of renal tubular vacuoles was higher in SUCROSE and slightly higher in LARD compared with CONT mice, and was higher in LARD and SUCROSE compared with SOY OIL mice. Most of those vacuoles were LAMP1-positive, a marker of lysosomal autophagy. These results suggest that despite identical energy contents, diets with high sucrose or saturated fat compared to unsaturated fat may aggravate lysosomal renal injury in a non-obese, streptozotocin-induced model of diabetes mellitus.