Figure 5. Effects of knock out SphK1 on FN and SphK-S1P signaling pathway in STZ-induced diabetic mice kidney.

The pathological analysis of glomerular was performed using PAS staining (A). Original magnification, ×400. Mesangial matrix index was defined as the PAS-positive area (B). The expression of FN was evaluated by western blotting (C). The densitometry analysis demonstrated that renal protein levels of FN were increased in untreated diabetic mice and reduced by SphK1 knockout (D). Kidney lysates were subjected to SphK activity assay (E), and Sphingosine 1-phosphate (S1P) quantification (F) using LC-MS/MS. *P < 0.05, **P < 0.01 vs. WT, # P < 0.05, ## P < 0.01 vs. WT+STZ.