Kidney injury and functional assay of LRRK2 -/- mice. A. Classical renal chemistry analysis shows normal levels of blood urea nitrogen (BUN) and serum creatinine as well as the ratio of BUN to serum creatinine in LRRK2-/- mice at 12-14 months of age. B. Western analysis shows dramatically increased levels of kidney injury molecule-1 (Kim-1), a tissue and urinary biomarker for renal injury, in RIPA buffer-soluble fractions of LRRK2-/- kidneys at the ages of 1 and 7 months, which is also increased in RIPA buffer-insoluble fractions of LRRK2-/- kidneys at 20 months of age, compared with wild-type controls. The Western blots of ERK1/2 or Ponceau S staining of the membranes are used as loading control, as levels of both GAPDH and β-actin are altered in LRRK2-/- kidneys. ns, not significant; *, P < 0.05; ***, P < 0.001.