Dysfunctional mitochondria participate in the progression of
chronic kidney disease (CKD).
Pirfenidone is a newly identified anti-fibrotic
drug. However, its mechanism remains unclear.
Mitochondrial dysfunction is an early event that occurs prior to the onset of renal
fibrosis. In this context, we investigated the protective effect of
pirfenidone on mitochondria and its relevance to apoptosis and oxidative stress in renal proximal tubular cells. A remnant kidney rat model was established. Human renal proximal tubular epithelial cells (HK2) using
rotenone, a mitochondrial respiratory chain complex Ι inhibitor were further investigated in vitro to examine the mitochondrial protective effect of
pirfenidone.
Pirfenidone protected mitochondrial structures and functions by stabilizing the mitochondrial membrane potential, maintaining
ATP production and improving the
mitochondrial DNA (
mtDNA) copy number.
Pirfenidone decreased tubular cell apoptosis by inhibiting the mitochondrial apoptotic signaling pathway.
Pirfenidone also reduced oxidative stress by enhancing
manganese superoxide dismutase (
Mn-SOD) and inhibiting intracellular
reactive oxygen species (ROS) generation, which suggested that the
anti-oxidant effects occurred at least partially via the mitochondrial pathway.
Pirfenidone may be effective prior to the onset of renal
fibrosis because this
drug exerts its anti-fibrotic effect by protection of mitochondria in renal proximal tubular cells.