Fig. 6. Low mRNA levels of Klotho is associated with high mRNA levels of ER stress markers in diabetic nephropathy patients and recombinant human Klotho regulates ER stress markers expression in response to Tunicamycin in an ex vivo model of human precision cut kidney slices.
a Correlation between mRNA level of Klotho (KL) in tubular fraction and mRNA level of ER stress markers in glomerular fraction i.e., HSPA5 coding for GRP78/BiP, HSP90B1 coding for GRP94, EIF2AK3 coding for PERK, ATF4, ATF3, DDIT3 coding for CHOP. Data are extracted from Levin et al.48. b Using RT-qPCR, mRNA expression of HSPA5, HSP90B1, DDIT3, unspliced and spliced XBP1 was measured in 300-μm-thick human kidney slices directly after slicing procedure (Baseline) or after a 24 h-treatment with either tunicamycin (TN, 1 μM) or recombinant human Klotho (r-hKL, 0.05 μg/ml). 28S was used as a housekeeping gene. Data represent the mean ± SD of 1 independent experiment performed in triplicates. *p < 0.05; **p < 0.01; ***p < 0.001. c Representative images of immunoperoxidase stainings for GRP78/BiP (left panel) and CHOP (right panel) in human kidney slices. Statistical significance between groups was determined using Pearson’s correlation test or one-way ANOVA followed by multiple comparisons.