Cell and tissue research
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Cell and tissue research · Jun 2012
Regulation of TGF-β storage and activation in the human idiopathic pulmonary fibrosis lung.
Idiopathic pulmonary fibrosis (IPF) is a progressive disease of unknown cause. The pathogenesis of the disease is characterized by fibroblast accumulation and excessive transforming growth factor-β (TGF-β) activation. Although TGF-β activation is a complex process involving various protein interactions, little is known of the specific routes of TGF-β storage and activation in human lung. ⋯ Fibrillin-2, a developmental gene expressed only in blood vessels in normal adult lung, was found specifically upregulated in IPF fibroblastic foci. The TGF-β-activating integrin β8 subunit was expressed at low levels in both control and IPF lungs. Alterations in extracellular matrix composition, such as high levels of the TGF-β storage protein LTBP-1 and the re-appearance of fibrillin-2, probably modulate TGF-β availability and activation in different pulmonary compartments in the fibrotic lung.