Benign prostatic hyperplasia: age-related tissue-remodeling.

Aging and androgens are the two established risk factors for the development of benign prostatic hyperplasia (BPH) and benign prostatic enlargement (BPE), which can lead to lower urinary tract symptoms (LUTS) in elderly men. BPH, consisting of a nodular overgrowth of the epithelium and fibromuscular tissue within transition zone and periurethral areas, is first detectable around the fourth decade of life and affects nearly all men by the ninth decade. The pathogenesis of BPH is still largely unresolved, but multiple partially overlapping and complementary theories have been proposed, all of which seem to be operative at least to some extent. In addition to nerve-, endocrine- and immune system, local para- and luminocrine pleiotrope mechanisms/factors are implicated in the prostatic tissue-remodeling process. Prostate tissue-remodeling in the transition zone is characterized by: (i) hypertrophic basal cells, (ii) altered secretions of luminal cells leading to calcification, clogged ducts and inflammation, (iii) lymphocytic infiltration with production of proinflammatory cytokines, (iv) increased radical oxygen species (ROS) production that damages epithelial and stromal cells, (v) increased basic fibroblast (bFGF) and transforming growth factor beta (TGF-beta 1) production leading to stromal proliferation, transdifferentiation and extracellular matrix production, (vi) altered autonomous innervation that decreases relaxation and leads to a high adrenergic tonus, (vii) and altered neuroendocine cell function and release of neuroendocrine peptides (NEP). This review summarizes the multifactorial nature of prostate tissue remodeling in elderly men with symptomatic BPH with a particular focus on changes of cell-cell interactions and cell functions in the human aging prostate.