Quantitative RT-PCR.

A transverse section of the middle of the kidney was snap frozen in liquid nitrogen, and RNA was extracted, cDNA was synthesized, and quantitative RT-PCR was performed as previously described (52). The following primer sequences were used: GAPDH, forward 5′-TGGAGAAACCTGCCAAGTATGA-3′ and reverse 5′-GAAGAGTGGGAGTTGCTGTTGA-3′; α-smooth muscle actin (α-SMA), forward 5′-CGCTGTCAGGAACCCTGAGA-3′ and reverse 5′-CGAAGCCGGCCTTACAGA-3′; lysyl oxidase-like 2 (LoxL2), forward 5′-GATCTTCAGCCCCGATGGA-3′ and reverse 5′-CAAGGGTTGCTCTGGCTTGT-3′; collagen type I-α₁ (Col1-α1), forward 5′-CCCGCCGATGTCGCTAT-3′ and reverse 5′-GCTACGCTGTTCTTGCAGTGAT-3′; and collagen type III-α₁ (Col3-α1), forward 5′-AGGCAACAGTGGTTCTCCTG-3′ and reverse 5′-GACCTCGTGCTCCAGTTAGC-3′.