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49 result(s) for "Voswinckel, Robert"
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Senescence-Associated Secretory Phenotype and Its Possible Role in Chronic Obstructive Pulmonary Disease
Chronic obstructive pulmonary disease (COPD) is a major disease of the lungs. It primarily occurs after a prolonged period of cigarette smoking. Chronic inflammation of airways and the alveolar space as well as lung tissue destruction are the hallmarks of COPD. Recently it has been shown that cellular senescence might play a role in the pathogenesis of COPD. Cellular senescence comprises signal transduction program, leading to irreversible cell cycle arrest. The growth arrest in senescence can be triggered by many different mechanisms, including DNA damage and its recognition by cellular sensors, leading to the activation of cell cycle checkpoint responses and activation of DNA repair machinery. Senescence can be induced by several genotoxic factors apart from telomere attrition. When senescence induction is based on DNA damage, senescent cells display a unique phenotype, which has been termed \"senescence-associated secretory phenotype\" (SASP). SASP may be an important driver of chronic inflammation and therefore may be part of a vicious cycle of inflammation, DNA damage, and senescence. This research perspective aims to showcase cellular senescence with relevance to COPD and the striking similarities between the mediators and secretory phenotype in COPD and SASP.
Validation of the German Version of Functional Oral Intake Scale (FOIS-G) for Flexible Endoscopic Evaluation of Swallowing (FEES)
The Functional Oral Intake Scale (FOIS) is the most frequently used scale for the evaluation of functional oral intake by dysphagia patients. FOIS was validated using data from Videofluoroscopic Swallowing Study (VFSS). Until now, a validated German version of FOIS for Flexible Endoscopic Evaluation of Swallowing (FEES) is lacking. The aim of this study was a cross-cultural validation of the German version of FOIS (FOIS-G) for FEES. The translation of the original FOIS was carried out according to the Translation, Review, Adjudication, Pretesting, Documentation (TRAPD) translation methodology. For the validation process, six experienced language therapists (SLT) retrospectively analyzed charts of 93 stroke patients. Inclusion criteria were comprised of stroke, clinical examination by an SLT within 24 h of admission, and FEES within 72 h of admission. The validity was calculated by comparison with Modified Rankin Scale (MRS), Barthel Index (BI), the Penetration-Aspiration-Scale (PAS), and a water swallow test. Spearman rank correlation of all paired raters ranged from rs = 0.96 to rs = 0.99, and percentage agreement ranged from 81 to 94%. The overall agreement between all raters was calculated by Fleiss kappa (0.83) (s.e. 0.02). There is a significant correlation between the BI and the MRS with the FOIS-G (rs = 0.301, p = 0.003 for BI; rs = – 0.366, p < 0.001 for MRS), between the PAS and the FOIS-G (rs = − 0.758, p < 0.001), as well as between the 70 ml-water-test and the FOIS-G (rs = 0.470, p < 0.001). FOIS-G is a valid instrument for the evaluation of the functional oral intake of food and liquids in dysphagia patients.
Evidence of Dysfunction of Endothelial Progenitors in Pulmonary Arterial Hypertension
Severe pulmonary arterial hypertension (PAH) is characterized by the formation of plexiform lesions and concentric intimal fibrosis in small pulmonary arteries. The origin of cells contributing to these vascular lesions is uncertain. Endogenous endothelial progenitor cells are potential contributors to this process. To determine whether progenitors are involved in the pathobiology of PAH. We performed immunohistochemistry to determine the expression of progenitor cell markers (CD133 and c-Kit) and the major homing signal pathway stromal cell-derived factor-1 and its chemokine receptor (CXCR4) in lung tissue from patients with idiopathic PAH, familial PAH, and PAH associated with congenital heart disease. Two separate flow cytometric methods were employed to determine peripheral blood circulating numbers of angiogenic progenitors. Late-outgrowth progenitor cells were expanded ex vivo from the peripheral blood of patients with mutations in the gene encoding bone morphogenetic protein receptor type II (BMPRII), and functional assays of migration, proliferation, and angiogenesis were undertaken. measurements and main results: There was a striking up-regulation of progenitor cell markers in remodeled arteries from all patients with PAH, specifically in plexiform lesions. These lesions also displayed increased stromal cell-derived factor-1 expression. Circulating angiogenic progenitor numbers in patients with PAH were increased compared with control subjects and functional studies of late-outgrowth progenitor cells from patients with PAH with BMPRII mutations revealed a hyperproliferative phenotype with impaired ability to form vascular networks. These findings provide evidence of the involvement of progenitor cells in the vascular remodeling associated with PAH. Dysfunction of circulating progenitors in PAH may contribute to this process.
Role of Epidermal Growth Factor Inhibition in Experimental Pulmonary Hypertension
Epidermal growth factor (EGF) and its receptors play a role in cell proliferation and survival and are implicated in the pathobiology of pulmonary arterial hypertension (PAH). To study the role of EGF inhibition on experimental pulmonary hypertension. We investigated (1) the effects of three clinically approved EGF receptor (EGFR) antagonists in vitro on rat pulmonary arterial smooth muscle cell proliferation and in vivo on experimental pulmonary hypertension (PH) induced by monocrotaline injection in rats and by chronic hypoxia in mice, and (2) the expression of EGFR in the lung tissues from experimental and clinical PH. The EGFR inhibitors gefitinib, erlotinib, and lapatinib inhibited the EGF-induced proliferation of pulmonary arterial smooth muscle cells. In rats with established PH, gefitinib and erlotinib significantly reduced right ventricular systolic pressure and right ventricular hypertrophy. In addition, the medial wall thickness and muscularization of pulmonary arteries were improved. In contrast, lapatinib did not provide therapeutic benefit. These EGFR antagonists at their highest tolerable dose did not yield significant improvement in right ventricular systolic pressure, right ventricular hypertrophy, and pulmonary vascular remodeling in mice with chronic hypoxic PH. Moreover, no significant alteration in the EGFR expression was detected in the lung tissues from patients with idiopathic PAH. The partial therapeutic efficacy of the EGFR antagonists in animal models of pulmonary hypertension and the absence of significant alteration in EGFR expression in the lungs from patients with idiopathic PAH suggest that EGFRs do not represent a promising target for the treatment of pulmonary hypertension.
Contrasting expression of canonical Wnt signaling reporters TOPGAL, BATGAL and Axin2(LacZ) during murine lung development and repair
Canonical WNT signaling plays multiple roles in lung organogenesis and repair by regulating early progenitor cell fates: investigation has been enhanced by canonical Wnt reporter mice, TOPGAL, BATGAL and Axin2(LacZ). Although widely used, it remains unclear whether these reporters convey the same information about canonical Wnt signaling. We therefore compared beta-galactosidase expression patterns in canonical Wnt signaling of these reporter mice in whole embryo versus isolated prenatal lungs. To determine if expression varied further during repair, we analyzed comparative pulmonary expression of beta-galactosidase after naphthalene injury. Our data show important differences between reporter mice. While TOPGAL and BATGAL lines demonstrate Wnt signaling well in early lung epithelium, BATGAL expression is markedly reduced in late embryonic and adult lungs. By contrast, Axin2(LacZ) expression is sustained in embryonic lung mesenchyme as well as epithelium. Three days into repair after naphthalene, BATGAL expression is induced in bronchial epithelium as well as TOPGAL expression (already strongly expressed without injury). Axin2(LacZ) expression is increased in bronchial epithelium of injured lungs. Interestingly, both TOPGAL and Axin2(LacZ) are up regulated in parabronchial smooth muscle cells during repair. Therefore the optimal choice of Wnt reporter line depends on whether up- or down-regulation of canonical Wnt signal reporting in either lung epithelium or mesenchyme is being compared.
Characterization of a Novel Fibroblast Growth Factor 10 (Fgf10) Knock-In Mouse Line to Target Mesenchymal Progenitors during Embryonic Development
Fibroblast growth factor 10 (Fgf10) is a key regulator of diverse organogenetic programs during mouse development, particularly branching morphogenesis. Fgf10-null mice suffer from lung and limb agenesis as well as cecal and colonic atresia and are thus not viable. To date, the Mlcv1v-nLacZ-24 transgenic mouse strain (referred to as Fgf10(LacZ)), which carries a LacZ insertion 114 kb upstream of exon 1 of Fgf10 gene, has been the only strain to allow transient lineage tracing of Fgf10-positive cells. Here, we describe a novel Fgf10(Cre-ERT2) knock-in line (Fgf10(iCre)) in which a Cre-ERT2-IRES-YFP cassette has been introduced in frame with the ATG of exon 1 of Fgf10 gene. Our studies show that Cre-ERT2 insertion disrupts Fgf10 function. However, administration of tamoxifen to Fgf10(iCre); Tomato(flox) double transgenic embryos or adult mice results in specific labeling of Fgf10-positive cells, which can be lineage-traced temporally and spatially. Moreover, we show that the Fgf10(iCre) line can be used for conditional gene inactivation in an inducible fashion during early developmental stages. We also provide evidence that transcription factors located in the first intron of Fgf10 gene are critical for maintaining Fgf10 expression over time. Thus, the Fgf10(iCre) line should serve as a powerful tool to explore the functions of Fgf10 in a controlled and stage-specific manner.
CD34 + Progenitor to Endothelial Cell Transition in Post-Pneumonectomy Angiogenesis
In many species, pneumonectomy triggers compensatory lung growth that results in an increase not only in lung volume, but also in alveolar number. Whether the associated alveolar angiogenesis involves the contribution of blood-borne progenitor cells is unknown. To identify and characterize blood-borne progenitor cells contributing to lung growth after pneumonectomy in mice, we studied wild-type and wild-type/green fluorescence protein (GFP) parabiotic mice after left pneumonectomy. Within 21 days of pneumonectomy, a 3.2-fold increase occurred in the number of lung endothelial cells. This increase in total endothelial cells was temporally associated with a 7.3-fold increase in the number of CD34(+) endothelial cells. Seventeen percent of the CD34(+) endothelial cells were actively proliferating, compared with only 4.2% of CD34(-) endothelial cells. Using wild-type/GFP parabiotic mice, we demonstrated that 73.4% of CD34(+) cells were derived from the peripheral blood. Furthermore, lectin perfusion studies demonstrated that CD34(+) cells derived from peripheral blood were almost uniformly incorporated into the lung vasculature. Finally, CD34(+) endothelial cells demonstrated a similar profile, but had enhanced transcriptional activity relative to CD34(-) endothelial cells. We conclude that blood-borne CD34(+) endothelial progenitor cells, characterized by active cell division and an amplified transcriptional signature, transition into resident endothelial cells during compensatory lung growth.
The Noncanonical WNT Pathway Is Operative in Idiopathic Pulmonary Arterial Hypertension
Idiopathic pulmonary arterial hypertension (IPAH) is a fatal disease that comprises sustained vasoconstriction, enhanced proliferation of pulmonary vascular cells, and in situ thrombosis. The discovery of several contributing signaling pathways in recent years has resulted in an expanding array of novel therapies; however, IPAH remains a progressive disease with poor outcome in most instances. To identify new regulatory pathways of vascular remodeling in IPAH, we performed transcriptome-wide expression profiling of laser-microdissected pulmonary arterial resistance vessels derived from explanted IPAH and nontransplanted donor lung tissues. Statistical analysis of the data derived from six individuals in each group showed significant regulation of several mediators of the canonical and noncanonical WNT pathway. As to the noncanonical WNT pathway, the planar cell polarity (PCP) pathway, the ras homolog gene family member A (RHOA), and ras-related C3 botulinum toxin substrate-1 (RAC1) were strongly up-regulated. Real-time PCR of laser-microdissected pulmonary arteries confirmed these array results and showed in addition significant up-regulation of further PCP mediators wingless member 11 (WNT11), disheveled associated activator of morphogenesis-1 (DAAM1), disheveled (DSV), and RHO-kinase (ROCK). Immunohistochemical staining and semiquantitative expression analysis confirmed the markedly enhanced expression of the PCP mediators in the pulmonary resistance vessels, in particular in the endothelial layer in IPAH. Therefore we propose the PCP pathway to be critically involved in the regulation of vascular remodeling in IPAH.