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Jay W Tichelaar

Publications and source records attributed to Jay W Tichelaar.

9 recordsLinked to original sources
PubMed2005

Increased staining for phospho-Akt, p65/RELA and cIAP-2 in pre-neoplastic human bronchial biopsies.

BACKGROUND: The development of non-small cell lung carcinoma proceeds through a series of well-defined pathological steps before the appearance of invasive lung carcinoma. The molecular changes that correspond with pathology changes are not well defined and identification of the molecular events may provide clues on the progression of intraepithelial neoplasia in the lung, as well as suggest potential targets for chemoprevention. The acquisition of anti-apoptotic signals is critical for the survival of cancer cells but the pathways involved are incompletely characterized in developing intra-epithelial neoplasia (IEN). METHODS: We used immunohistochemistry to determine the presence, relative levels, and localization of proteins that mediate anti-apoptotic pathways in developing human bronchial neoplasia. RESULTS: Bronchial epithelial protein levels of the phosphorylated (active) form of AKT kinase and the caspase inhibitor cIAP-2 were increased in more advanced grades of bronchial IEN lesions than in normal bronchial epithelium. Additionally, the percentage of biopsies with nuclear localization of p65/RELA in epithelial cells increased with advancing pathology grade, suggesting that NF-kappaB transcriptional activity was induced more frequently in advanced IEN lesions. CONCLUSION: Our results indicate that anti-apoptotic pathways are elevated in bronchial IEN lesions prior to the onset of invasive carcinoma and that targeting these pathways therapeutically may offer promise in prevention of non-small cell lung carcinoma.

Apoptosis↗
PubMed2005

Gene expression changes during the development of acute lung injury: role of transforming growth factor beta.

RATIONALE: Acute lung injury can occur from multiple causes, resulting in high mortality. The pathophysiology of nickel-induced acute lung injury in mice is remarkably complex, and the molecular mechanisms are uncertain. OBJECTIVES: To integrate molecular pathways and investigate the role of transforming growth factor beta (TGF-beta) in acute lung injury in mice. METHODS: cDNA microarray analyses were used to identify lung gene expression changes after nickel exposure. MAPPFinder analysis of the microarray data was used to determine significantly altered molecular pathways. TGF-beta1 protein in bronchoalveolar lavage fluid, as well as the effect of inhibition of TGF-beta, was assessed in nickel-exposed mice. The effect of TGF-beta on surfactant-associated protein B (Sftpb) promoter activity was measured in mouse lung epithelial cells. MEASUREMENTS AND MAIN RESULTS: Genes that decreased the most after nickel exposure play important roles in lung fluid absorption or surfactant and phospholipid synthesis, and genes that increased the most were involved in TGF-beta signaling. MAPPFinder analysis further established TGF-beta signaling to be significantly altered. TGF-beta-inducible genes involved in the regulation of extracellular matrix function and fibrinolysis were significantly increased after nickel exposure, and TGF-beta1 protein was also increased in the lavage fluid. Pharmacologic inhibition of TGF-beta attenuated nickel-induced protein in bronchoalveolar lavage. In addition, treatment with TGF-beta1 dose-dependently repressed Sftpb promoter activity in vitro, and a novel TGF-beta-responsive region in the Sftpb promoter was identified. CONCLUSIONS: These data suggest that TGF-beta acts as a central mediator of acute lung injury through the alteration of several different molecular pathways.

Animals↗
PubMed2005

Over expression of FGF7 enhances cell proliferation but fails to cause pathology in corneal epithelium of Kerapr-rtTA/FGF7 bitransgenic mice.

PURPOSE: Available evidence suggests that fibroblast growth factor 7 (FGF7, also known as keratinocyte growth factor, KGF) serves as a paracrine growth factor modulating corneal epithelial cell proliferation. In the present study, we used a binary inducible transgenic mouse model to examine the role of FGF7 on corneal epithelium proliferation. METHODS: A keratocyte specific 3.2 kb murine keratocan promoter (Kerapr) was used to prepare Kerapr-rtTA transgenic (Kr) mice that constitutively overexpress reverse tetracycline transcription activator (rtTA) by cornea stromal keratocytes. The Kr mice were crossed with tet-O-FGF7 mice to produce Kr/tet-O-FGF7 bitransgenic mice. Expression of human FGF7 (hFGF7) was induced by the administration of doxycycline via intraperitoneal injection and/or feeding mice doxycycline in drinking water and chow. Overexpression of hFGF7 was confirmed by RT-PCR and western blot. BrdU incorporation was used to determine cell proliferation. RESULTS: The rtTA mRNA and protein were constitutively expressed by the cornea with or without doxycycline induction, whereas hFGF7 was detected only in Kr/tet-O-FGF7 bitransgenic mice upon induction by doxycycline. Examination of induction kinetics in adult Kr/tet-O-FGF7 bitransgenic mice after a single intraperitoneal injection of doxycycline revealed that hFGF7 mRNA expression was detected 12 h after doxycycline administration, peaked at 36 h, was sustained up to 48 h, and declined thereafter. The elevated level of hFGF7 expression coincided with hyperproliferation of corneal epithelial cells. In bitransgenic mice, the number of BrdU labeled cells increased after 36 and 48 h of transgene induction compared to controls of noninduced bitransgenic or doxycycline treated single transgenic mice. The BrdU labeling index was 33+/-9.2 positive cells per corneal section for Kr/tet-O-FGF7 bitransgenic mice and 25+/-9.3 for tet-O-FGF7 single transgenic mice at 36 h post-doxycycline treatment. However, the excess FGF7 driven by doxycycline induction did not produce severe perturbation of corneal epithelium homeostasis. CONCLUSIONS: Our results demonstrate that the doxycycline inducible system is effective in regulating transgene expression in corneal stroma of Kr/tet-O-FGF7 bitransgenic mice. However, the development of pathology resulting from the overexpression of transgenes may depend on whether the amount of transgene product present is sufficient to alter the homeostasis of the targeted tissues.

Animals↗
PubMed2005

Interleukin-1beta causes pulmonary inflammation, emphysema, and airway remodeling in the adult murine lung.

The production of the inflammatory cytokine interleukin (IL)-1 is increased in lungs of patients with chronic obstructive pulmonary disease (COPD) or asthma. To characterize the in vivo actions of IL-1 in the lung, transgenic mice were generated in which human IL-1beta was expressed in the lung epithelium with a doxycycline-inducible system controlled by the rat Clara cell secretory protein (CCSP) promoter. Induction of IL-1beta expression in the lungs of adult mice caused pulmonary inflammation characterized by neutrophil and macrophage infiltrates. IL-1beta caused distal airspace enlargement, consistent with emphysema. IL-1beta caused disruption of elastin fibers in alveolar septa and fibrosis in airway walls and in the pleura. IL-1beta increased the thickness of conducting airways, enhanced mucin production, and caused lymphocytic aggregates in the airways. Decreased immunostaining for the winged helix transcription factor FOXA2 was associated with goblet cell hyperplasia in IL-1beta-expressing mice. The production of the neutrophil attractant CXC chemokines KC (CXCL1) and MIP-2 (CXCL2), and of matrix metalloproteases MMP-9 and MMP-12, was increased by IL-1beta. Chronic production of IL-1beta in respiratory epithelial cells of adult mice causes lung inflammation, enlargement of distal airspaces, mucus metaplasia, and airway fibrosis in the adult mouse.

Animals↗
PubMed2003

Conditional expression of transforming growth factor-alpha in adult mouse lung causes pulmonary fibrosis.

To determine whether overexpression of transforming growth factor (TGF)-alpha in the adult lung causes remodeling independently of developmental influences, we generated conditional transgenic mice expressing TGF-alpha in the epithelium under control of the doxycycline (Dox)-regulatable Clara cell secretory protein promoter. Two transgenic lines were generated, and following 4 days of Dox-induction TGF-alpha levels in whole lung homogenate were increased 13- to 18-fold above nontransgenic levels. After TGF-alpha induction, transgenic mice developed progressive pulmonary fibrosis and body weight loss, with mice losing 15% of their weight after 6 wk of TGF-alpha induction. Fibrosis was detected within 4 days of TGF-alpha induction and developed initially in the perivascular, peribronchial, and pleural regions but later extended into the interstitium. Fibrotic regions were composed of increased collagen and cellular proliferation and were adjacent to airway and alveolar epithelial sites of TGF-alpha expression. Fibrosis progressed in the absence of inflammatory cell infiltrates as determined by histology, without changes in bronchiolar alveolar lavage total or differential cell counts and without changes in proinflammatory cytokines TNF-alpha or IL-6. Active TGF-beta in whole lung homogenate was not altered 1 and 4 days after TGF-alpha induction, and immunostaining was not increased in the peribronchial/perivascular areas at all time points. Chronic epithelial expression of TGF-alpha in adult mice caused progressive pulmonary fibrosis associated with increased collagen and extracellular matrix deposition and increased cellular proliferation. Induction of pulmonary fibrosis by TGF-alpha was independent of inflammation or early activation of TGF-beta.

Age Factors↗
PubMed2003

SP-B deficiency causes respiratory failure in adult mice.

Targeted deletion of the surfactant protein (SP)-B locus in mice causes lethal neonatal respiratory distress. To assess the importance of SP-B for postnatal lung function, compound transgenic mice were generated in which the mouse SP-B cDNA was conditionally expressed under control of exogenous doxycycline in SP-B-/- mice. Doxycycline-regulated expression of SP-B fully corrected lung function in compound SP-B-/- mice and protected mice from respiratory failure at birth. Withdrawal of doxycycline from adult compound SP-B-/- mice resulted in decreased alveolar content of SP-B, causing respiratory failure when SP-B concentration was reduced to <25% of normal levels. Decreased SP-B was associated with low alveolar content of phosphatidylglycerol, accumulation of misprocessed SP-C proprotein in the air spaces, increased protein content in bronchoalveolar lavage fluid, and altered surfactant activity in vitro. Consistent with surfactant dysfunction, hysteresis, maximal tidal volumes, and end expiratory volumes were decreased. Reduction of alveolar SP-B content causes surfactant dysfunction and respiratory failure, indicating that SP-B is required for postnatal lung function.

Age Factors↗
PubMed2002

Fibroblast growth factor 18 influences proximal programming during lung morphogenesis.

The structure and functions of the airways of the lung change dramatically along their lengths. Large-diameter conducting airways are supported by cartilaginous rings and smooth muscle tissue and are lined by ciliated and secretory epithelial cells that are involved in mucociliary clearance. Smaller peripheral airways formed during branching morphogenesis are lined by cuboidal and squamous cells that facilitate gas exchange to a network of fine capillaries. The factors that mediate formation of these changing cell types and structures along the length of the airways are unknown. We report here that conditional expression of fibroblast growth factor (FGF)-18 in epithelial cells of the developing lung caused the airway to adopt structural features of proximal airways. Peripheral lung tubules were markedly diminished in numbers, whereas the size and extent of conducting airways were increased. Abnormal smooth muscle and cartilage were found in the walls of expanded distal airways, which were accompanied by atypically large pulmonary blood vessels. Expression of proteins normally expressed in peripheral lung tubules, including SP-B and pro-SP-C, was inhibited. FGF-18 mRNA was detected in normal mouse lung in stromal cells surrounding proximal airway cartilage and in peripheral lung mesenchyme. Effects were unique to FGF-18 because expression of other members of the FGF family had different consequences. These data show that FGF-18 is capable of enhancing proximal and inhibiting peripheral programs during lung morphogenesis.

Animals↗
PubMed2002

Conditional gene expression in the respiratory epithelium of the mouse.

Transgenic mouse models mediating conditional temporal and spatial regulation of gene expression to the respiratory epithelium were developed utilizing the reverse tetracycline transactivator (rtTA) expressed under the control of SP-C and CCSP promoters. Luciferase activity was detected in the lungs of fetal and adult double transgenic mice but was not detected in other tissues or in single transgenic mice. In adult mice, maximal luciferase activity was detected 16 h after the administration of doxycycline in the drinking water, or 2 h after the injection of doxycycline. Activation of the transgene was observed after the administration of doxycycline in food pellets. After prolonged exposure to doxycycline, luciferase activity decreased slowly following removal of doxycycline, suggesting the importance of tissue pools which maintained expression of the transgene. In SP-C-rtTA mice, exposure of the pregnant dam to doxycycline induced luciferase activity in fetal lung tissue as early as E10.5. Luciferase activity was maintained in the lung tissue of pups during the period of lactation when the mother received doxycycline in the drinking water. In the CCSP-rtTA mice, luciferase was not detected in the absence of doxycycline. In the SP-C-rtTA mice, luciferase activity was detected in the absence of doxycycline but was enhanced approximately 10-fold by administration of drugs. The SP-C-rtTA and CCSP-rtTA activator mice control the expression of transgenes in the developing and mature respiratory epithelium, and will be useful for the study of gene function in the lung.

Animals↗