Renal Fibrosis of Polycystic Kidney Disease (PKD)

Due to congenital hereditary gene mutation, factors that can cause cyst growing are released, causing abnormality to basement membrane of renal tubule. Besides, growth factors, like EGF, TGF-βand IGF , which can speed up proliferation and secretion of epithelial cells on renal tubular wall are released continuously, and all these factors can cause and aggravate Renal Fibrosis.

Epithelial cells proliferation can cause renal tubular obstruction, leading to liquid retention which can swell into cyst in upper tubule. Besides, proliferation can also cause half-obstructed condition at cyst neck, which can block fluid flow out. Then cysts grow bigger and bigger.

Growing and increasing cysts compress kidney further, which can cause renal ischemia and anoxia, starting the process of Renal Fibrosis. Once Renal Fibrosis begins, it continues to produce a series of nephrotoxic cell factors and growth factors, all of which can stimulate epithelial cells of renal tubule to have Phenotype transformation, producing Myofibroblast, secreting and synthesizing Extracellular Matrix (ECM) which is difficult to be degraded.


With Renal Fibrosis developing further, more ECM is synthesized with less degradation, which leads to unbalance between ECM synthesis and ECM degradation. Large amount of ECM accumulation and deposite can cause glomerular sclerosis and renal tubular atrophy. Then fibrous tissue will replace healthy nephron more and more.