title: Alteration in the Wnt microenvironment directly regulates molecular events leading to pulmonary senescence.
abstract: In the aging lung, the lung capacity decreases even in the absence of diseases. The progenitor cells of the distal lung, the alveolar type II cells (ATII), are essential for the repair of the gas-exchange surface. Surfactant protein production and survival of ATII cells are supported by lipofibroblasts that are peroxisome proliferator-activated receptor gamma (PPARγ)-dependent special cell type of the pulmonary tissue. PPARγ levels are directly regulated by Wnt molecules; therefore, changes in the Wnt microenvironment have close control over maintenance of the distal lung. The pulmonary aging process is associated with airspace enlargement, decrease in the distal epithelial cell compartment and infiltration of inflammatory cells. qRT-PCR analysis of purified epithelial and nonepithelial cells revealed that lipofibroblast differentiation marker parathyroid hormone-related protein receptor (PTHrPR) and PPARγ are reduced and that PPARγ reduction is regulated by Wnt4 via a β-catenin-dependent mechanism. Using a human in vitro 3D lung tissue model, a link was established between increased PPARγ and pro-surfactant protein C (pro-SPC) expression in pulmonary epithelial cells. In the senile lung, both Wnt4 and Wnt5a levels increase and both Wnt-s increase myofibroblast-like differentiation. Alteration of the Wnt microenvironment plays a significant role in pulmonary aging. Diminished lipo- and increased myofibroblast-like differentiation are directly regulated by specific Wnt-s, which process also controls surfactant production and pulmonary repair mechanisms.
authors: Medical School, Department of Pharmaceutical Biotechnology, University of Pécs, Pécs, Hungary; János Szentágothai Research Centre, University of Pécs, Pécs, Hungary.
authors: Tamas
authors: T
authors: Kovacs
authors: Veronika
authors: V
authors: Csongei
authors: Diana
authors: D
authors: Feller
authors: David
authors: D
authors: Ernszt
authors: Gabor
authors: G
authors: Smuk
authors: Veronika
authors: V
authors: Sarosi
authors: Laszlo
authors: L
authors: Jakab
authors: Krisztian
authors: K
authors: Kvell
authors: Domokos
authors: D
authors: Bartis
authors: Judit E
authors: JE
authors: Pongracz
mesh_terms: D000818:Animals; D016922:Cellular Senescence / Q000502:physiology*; D006801:Humans; D008168:Lung / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D047495:PPAR gamma / Q000378:metabolism*; D051153:Wnt Proteins / Q000378:metabolism*
chemical_list: D047495:PPAR gamma; D051153:Wnt Proteins
keywords: Wnt microenvironment; molecular biology of aging; pulmonary senescence