Expression of WNT5A in Idiopathic Pulmonary Fibrosis and Its Control by TGF-β and WNT7B in Human Lung Fibroblasts.

The wingless (Wnt) family of signaling ligands contributes significantly to lung development and is highly expressed in patients with usual interstitial pneumonia (UIP). We sought to define the cellular distribution of Wnt5A in the lung tissue of patients with idiopathic pulmonary fibrosis (IPF) and the signaling ligands that control its expression in human lung fibroblasts and IPF myofibroblasts. Tissue sections from 40 patients diagnosed with IPF or UIP were probed for the immunolocalization of Wnt5A.

Heparin and LPS-induced COX-2 expression in airway cells: a link between its anti-inflammatory effects and GAG sulfation.

Purpose/aim: Previous studies have indicated that the sulfated polysaccharide heparin has anti-inflammatory effects. However, the mechanistic basis for these effects has not been fully elucidated.

Materials And Methods: NCI-H292 (mucoepidermoid) and HBE-1 (normal) human bronchial epithelial cells were treated with LPS alone or in the presence of high-molecular-weight (HMW) fully sulfated heparin or desulfated HMW heparin.

MARCKS-dependent mucin clearance and lipid metabolism in ependymal cells are required for maintenance of forebrain homeostasis during aging.

Ependymal cells (ECs) form a barrier responsible for selective movement of fluids and molecules between the cerebrospinal fluid and the central nervous system. Here, we demonstrate that metabolic and barrier functions in ECs decline significantly during aging in mice. The longevity of these functions in part requires the expression of the myristoylated alanine-rich protein kinase C substrate (MARCKS).

Whole-genome analysis of temporal gene expression during early transdifferentiation of human lung alveolar epithelial type 2 cells in vitro.

It is generally accepted that the surfactant-producing pulmonary alveolar epithelial type II (AT2) cell acts as the progenitor of the type I (AT1) cell, but the regulatory mechanisms involved in this relationship remain the subject of active investigation. While previous studies have established a number of specific markers that are expressed during transdifferentiation from AT2 to AT1 cells, we hypothesized that additional, previously unrecognized, signaling pathways and relevant cellular functions are transcriptionally regulated at early stages of AT2 transition. In this study, a discovery-based gene expression profile analysis was undertaken of freshly isolated human AT2 (hAT2) cells grown on extracellular matrix (ECM) substrata known to either support (type I collagen) or retard (Matrigel) the early transdifferentiation process into hAT1-like cells over the first three days.

Expression of fibroblast growth factor 9 in normal human lung and idiopathic pulmonary fibrosis.

The fibroblast growth factor (FGF) family of signaling ligands contributes significantly to lung development and maintenance in the adult. FGF9 is involved in control of epithelial branching and mesenchymal proliferation and expansion in developing lungs. However, its activity and expression in the normal adult lung and by epithelial and interstitial cells in fibroproliferative diseases like idiopathic pulmonary fibrosis (IPF) are unknown.

Over-expression of human endosulfatase-1 exacerbates cadmium-induced injury to transformed human lung cells in vitro.

Environmental exposure to cadmium is known to cause damage to alveolar epithelial cells of the lung, impair their capacity to repair, and result in permanent structural alterations. Cell surface heparan sulfate proteoglycans (HSPGs) can modulate cell responses to injury through their interactions with soluble effector molecules. These interactions are often sulfate specific, and the removal of sulfate groups from HS side chains could be expected to influence cellular injury, such as that caused by exposure to cadmium.

HSULF-1 inhibits ERK and AKT signaling and decreases cell viability in vitro in human lung epithelial cells.

Background: Heparan sulfate proteoglycans (HSPGs) modulate the binding and activation of signaling pathways of specific growth factors, such as fibroblast growth factor-2 (FGF-2). Human endosulfatase 1 (HSULF-1) is an enzyme that selectively removes 6-O sulfate groups from HS side chains and alter their level and pattern of sulfation and thus biological activity. It is known that HSULF-1 is expressed at low levels in some cancer cell lines and its enhanced expression can inhibit cancer cell growth or induce apoptosis, but the mechanism(s) involved has not been identified.

WNT7B in fibroblastic foci of idiopathic pulmonary fibrosis.

Background: Idiopathic pulmonary fibrosis (IPF) is a devastating interstitial pneumonia causing a loss of respiratory surface area due to a proliferative fibrotic response involving hyperplastic, hypertrophic, and metaplastic epithelium, cystic honeycomb change, septal expansion, and variable inflammation. Wnt (wingless) signaling glycoproteins are known to be involved in lung development and tissue repair, and are up-regulated in patients with IPF. Based on previous qRT-PCR data showing increased Wnt7B in lungs of IPF patients, a systematic, quantitative examination of its tissue site distribution was undertaken.

Heterotaxin: a TGF-β signaling inhibitor identified in a multi-phenotype profiling screen in Xenopus embryos.

Disruptions of anatomical left-right asymmetry result in life-threatening heterotaxic birth defects in vital organs. We performed a small molecule screen for left-right asymmetry phenotypes in Xenopus embryos and discovered a pyridine analog, heterotaxin, which disrupts both cardiovascular and digestive organ laterality and inhibits TGF-β-dependent left-right asymmetric gene expression. Heterotaxin analogs also perturb vascular development, melanogenesis, cell migration, and adhesion, and indirectly inhibit the phosphorylation of an intracellular mediator of TGF-β signaling.

Temporal changes in expression of FoxA1 and Wnt7A in isolated adult human alveolar epithelial cells enhanced by heparin.

Pre- and postnatal developmental studies of the lung have provided compelling evidence demonstrating multiple factors that orchestrate alveolar epithelial cell differentiation. The extent to which reactivation of certain developmental pathways in the adult might influence the course of differentiation of alveolar type 2 cells (AT2) into AT1 cells is not known. In this study, we examined selected members of the forkhead (Fox) family of transcription factors and the Wnt (wingless) family of signaling proteins for expression during human alveolar cell differentiation in vitro and determined their potential responses to sulfated components of extracellular matrix (ECM), like those shed from cell surfaces or found in basement membrane and modeled by heparin.

Fibroblast growth factor-binding protein and N-deacetylase/N-sulfotransferase-1 expression in type II cells is modulated by heparin and extracellular matrix.

Fibroblast growth factors (FGFs) play critical roles in development, maintenance, and repair following injury or disease in the lung. Their activity is modulated by a variety of factors, including FGF-binding protein (FGF-BP; HBp-17) and N-deacetylase/N-sulfotransferase-1 (NDST-1). Functionally, FGF-BP shuttles FGFs from binding sites in ECMs to cell surfaces and enhances FGF binding and signaling, whereas NDST-1 adds sulfate groups to FGF coreceptor proteoglycans and modulates alveolar type II (ATII) cell maturation and differentiation.

Alterations in cytoskeletal and immune function-related proteome profiles in whole rat lung following intratracheal instillation of heparin.

Background: Heparin has been shown to modify fundamental biologic processes ranging from blood coagulation and cell proliferation to fibrogenesis and asthma. The goal of this study was to identify specific or broad biologic responses of the rat lung to intratracheal instillation of heparin by targeted proteomic analysis.

Methods: Rats were given either aerosolized 500 microg heparin in 250 microl saline or saline alone.

Heparin and fibroblast growth factors affect surfactant protein gene expression in type II cells.

The stimulation and maintenance of the pulmonary alveolar type II cell's capacity to biosynthesize, store, and secrete surfactant proteins (SPs) are modulated to a great extent by growth factors, extracellular matrix (ECM) components, and hormones. It is possible that differences in ECM composition, as exist between type I and II cells normally or as might occur with excessive cell surface shedding during inflammation or injury states, may specifically alter SP expression. Here, isolated type II cells were exposed to the model sulfated ECM heparin; desulfated heparin; and/or fibroblast growth factor (FGF)-1, -2, or -7 for 24 h to examine by quantitative real-time polymerase chain reaction their effects on SP gene expression.

Heparin affects signaling pathways stimulated by fibroblast growth factor-1 and -2 in type II cells.

Undersulfation of the basement membrane matrix of alveolar type II (AT2) cells compared with that of neighboring type I cells is believed to account for some of the known morphological and functional differences between these pneumocytes. Heparin, a model for sulfated components of basement membrane matrices, is known to inhibit fibroblast growth factor (FGF)-2-stimulated DNA synthesis as well as gene expression of FGF-2 and its receptor in AT2 cells. To determine whether these end points result from specific effects of heparin on FGF-related signaling pathways, isolated rat AT2 cells were treated with 100 ng/ml FGF-1 or FGF-2 in the presence of up to 500 microg/ml heparin.

Atypical development of the tracheal basement membrane zone of infant rhesus monkeys exposed to ozone and allergen.

Development of the basement membrane zone (BMZ) occurs postnatally in the rhesus monkey. The purpose of this study was to determine whether house dust mite allergen (HDMA) plus ozone altered this process. Rhesus monkeys were exposed to a regimen of HDMA and/or ozone or filtered air for 6 mo.

Fibroblast growth factor-2 in remodeling of the developing basement membrane zone in the trachea of infant rhesus monkeys sensitized and challenged with allergen.

Remodeling of the epithelial basement membrane zone (BMZ) involves increased deposition of collagen, resulting in thickening of the BMZ. The current study focuses on fibroblast growth factor-2 (FGF-2) in the tracheal BMZ in house dust mite allergen (HDMA)-sensitized infant rhesus monkeys, challenged with HDMA at a time when the BMZ is undergoing active postnatal development. To detect structural changes in the BMZ, we measured collagens I, III, and V.

Fibroblast growth factor-2 during postnatal development of the tracheal basement membrane zone.

Thickening of the basement membrane zone (BMZ) is a characteristic of several airway diseases; however, very little is known about how this process occurs. The purpose of this study was to define development of the BMZ in the trachea of growing rhesus monkeys at 1, 2, 3, and 6 mo of age. We measured immunoreactivity of collagen types I, III, and V to detect structural changes in the developing BMZ.

Heparin inhibits DNA synthesis and gene expression in alveolar type II cells.

Responses of isolated type II alveolar cells to fibroblast growth factors (FGF) have been shown to be sensitive to the level of sulfation in extracellular matrix (ECM) substrata. These observations may reflect the specific in situ distribution and level of sulfation of ECM within the alveolar basement membranes (ABM) associated with type II cells. The goal of this study was to determine if the model sulfated ECM heparin modified DNA synthesis and gene expression by type II cells in a concentration dependent-manner.

Effect of growth factor-fibronectin matrix interaction on rat type II cell adhesion and DNA synthesis.

Type II cells attach, migrate, and proliferate on a provisional fibronectin-rich matrix during alveolar wall repair after lung injury. The combination of cell-substratum interactions via integrin receptors and exposure to local growth factors are likely to initiate the signals required for cell proliferation, differentiation, reepithelialization, and ultimate restoration of the alveolar wall structure. Accordingly, primary cultured type II cells have been shown to bind fibronectin, in part through the alpha5beta1 integrin, and to respond to growth factors that induce type II cell proliferation, such as fibroblast growth factor 1 (FGF-1).

Detection of chondroitin sulfates and decorin in developing fetal and neonatal rat lung.

Chondroitin sulfates and their related proteoglycans are components of extracellular matrix that act as key determinants of growth and differentiation characteristics of developing lungs. Changes in their immunohistochemical distribution during progressive organ maturation were examined with monospecific antibodies to chondroitin sulfate, a nonbasement membrane chondroitin sulfate proteoglycan, and the specific chondroitin sulfate-containing proteoglycan decorin in whole fetuses and lungs from newborn and adult rats. Alveolar and airway extracellular matrix immunostained heavily in the prenatal rat for both chondroitin sulfate and chondroitin sulfate proteoglycan, whereas decorin was confined to developing airways and vessels.

Transforming growth factor-beta(1) modifies fibroblast growth factor-2 production in type II cells.

Transforming growth factor (TGF)-beta(1) is an inflammatory cytokine that plays multiple roles in pulmonary fibrosis. In vascular epithelium, it has been shown to regulate production and activity of fibroblast growth factor (FGF)-2, a potent type II cell mitogen in the lung. Such a relationship could have important consequences in prefibrotic change in the lung alveolus, where reepithelialization of alveolar surfaces is crucial.

Vanadium stimulates human bronchial epithelial cells to produce heparin-binding epidermal growth factor-like growth factor: a mitogen for lung fibroblasts.

The bronchial epithelium is a potential source of growth factors that could mediate airway fibrosis during the progression of diseases such as asthma and chronic bronchitis. We report that conditioned medium (CM) from normal human bronchial epithelial cells (NHBECs) contains mitogenic activity for human lung fibroblasts that is blocked by the epidermal growth factor receptor (EGF-R) tyrosine kinase inhibitor AG1478 and by neutralizing antibodies raised against heparin-binding epidermal growth factor-like growth factor (HB-EGF). Neutralizing antibodies against other EGF-R ligands (EGF and transforming growth factor-alpha) or other antibodies against growth factors (platelet-derived growth factors, insulin-like growth factor-1) had no affect on the mitogenic activity of NHBEC-CM.

TGF-beta1 and fibroblast growth factor-1 modify fibroblast growth factor-2 production in type II cells.

Fibroblast growth factor (FGF)-2, which stimulates DNA synthesis by type II cells in the lung, has been shown to be regulated by transforming growth factor (TGF)-beta1, an important inflammatory cytokine, in vascular epithelium. The goal of this study was to determine if FGF-2 production by alveolar type II cells is modulated by TGF-beta1 or FGF-1, which also stimulates DNA synthesis by type II cells. Isolated rat type II cells were exposed to 0-40 ng/ml of TGF-beta1 or 0-500 ng/ml of FGF-1 in serum-free medium for 1-5 days.