Project description:We have previously reported a subpopulation of bone marrow cells (BMC) that express Clara cell secretory protein (CCSP), generally felt to be specific to lung Clara cells. Ablation of lung Clara cells has been reported using a transgenic mouse that expresses thymidine kinase under control of the CCSP promoter. Treatment with ganciclovir results in permanent elimination of CCSP(+) cells, failure of airway regeneration, and death. To determine if transtracheal delivery of wild-type bone marrow CCSP(+) cells is beneficial after ablation of lung CCSP(+) cells, transgenic mice were treated with ganciclovir followed by transtracheal administration of CCSP(+) or CCSP(-) BMC. Compared with mice administered CCSP(-) cells, mice treated with CCSP(+) cells had more donor cells lining the airway epithelium, where they expressed epithelial markers including CCSP. Although donor CCSP(+) cells did not substantially repopulate the airway, their administration resulted in increased host ciliated cells, better preservation of airway epithelium, reduction of inflammatory cells, and an increase in animal survival time. Administration of CCSP(+) BMC is beneficial after permanent ablation of lung Clara cells by increasing bronchial epithelial repair. Therefore, CCSP(+) BMC could be important for treatment of lung diseases where airways re-epithelialization is compromised.
Project description:Chronic lung diseases are marked by excessive inflammation and epithelial remodeling. Reduced Clara cell secretory function and corresponding decreases in the abundance of the major Clara cell secreted protein, CCSP, are characteristically seen in these disease states. We sought to define the impact of Clara cell and CCSP depletion on regulation of the lung inflammatory response. We used chemical and genetic mouse models of Clara cell and CCSP deficiency (CCSP-/-) coupled with P. aeruginosa lipopolysaccharide (LPS) elicited inflammation. Exposure of Clara cell depleted or CCSP-/- mice to LPS resulted in augmented inflammation as assessed by polymorphonuclear leukocyte recruitment to the airspace. Gene expression analysis and pathway modeling of the CCSP-/- inflammatory response implicated increased TNF-alpha signaling. Consistent with this model was the demonstration of significantly elevated TNF-alpha in airway fluid of LPS-stimulated CCSP-/- mice compared to similarly exposed wild type mice. Increased LPS-elicited TNF-alpha production was also observed in cultured lung macrophages from CCSP-/- mice compared to wild type mice. We demonstrate that macrophages from Clara cell depleted and CCSP-/- mice displayed increased TLR4 surface expression. Our results provide evidence that Clara cells can attenuate inflammation through regulation of macrophage behavior and suggest that epithelial remodeling leading to reduced Clara cell secretory function is an important factor that increases the intensity of lung inflammation in chronic lung disease.
Project description:Administration of human subject research is complex, involving not only the institutional review board but also many other regulatory and compliance entities within a research enterprise. Its efficiency has a direct and substantial impact on the conduct and management of clinical research. In this paper, we report on the Clinical Research Administration (CLARA) platform developed at the University of Arkansas for Medical Sciences. CLARA is a comprehensive web-based system that can streamline research administrative tasks such as submissions, reviews, and approval processes for both investigators and different review committees on a single integrated platform. CLARA not only helps investigators to meet regulatory requirements but also provides tools for managing other clinical research activities including budgeting, contracting, and participant schedule planning.
Project description:BackgroundClara cells are the epithelial progenitor cell of the small airways, a location known to be important in many lung disorders. Although migration of alveolar type II and bronchiolar ciliated epithelial cells has been examined, the migratory response of Clara cells has received little attention.MethodsUsing a modification of existing procedures for Clara cell isolation, we examined mouse Clara cells and a mouse Clara-like cell line (C22) for adhesion to and migration toward matrix substrate gradients, to establish the nature and integrin dependence of migration in Clara cells.ResultsWe observed that Clara cells adhere preferentially to fibronectin (Fn) and type I collagen (Col I) similar to previous reports. Migration of Clara cells can be directed by a fixed gradient of matrix substrates (haptotaxis). Migration of the C22 cell line was similar to the Clara cells so integrin dependence of migration was evaluated with this cell line. As determined by competition with an RGD containing-peptide, migration of C22 cells toward Fn and laminin (Lm) 511 (formerly laminin 10) was significantly RGD integrin dependent, but migration toward Col I was RGD integrin independent, suggesting that Clara cells utilize different receptors for these different matrices.ConclusionThus, Clara cells resemble alveolar type II and bronchiolar ciliated epithelial cells by showing integrin mediated pro-migratory changes to extracellular matrix components that are present in tissues after injury.
Project description:SLC6A3, which encodes the primary regulator of extracellular dopamine (DA) concentration, the DA transporter, has been implicated in schizophrenia (SCZ). However, the details of its genetic effect on risk remain largely unknown. The purpose of this candidate gene study was to identify a specificSLC6A3activity associated with SCZ by using functional genetic approaches. We first examined gene activity in DA neurons isolated from case-control postmortem nigral tissue and found that the averageSLC6A3mRNA level in controls was only 0.37-fold of that in cases (P= .0034). To understand this expression difference, we examined the association of 10 genetic markers, mostly located in the promoter region, with SCZ in 1717 subjects collected from Toronto and McLean cohorts, including 881 controls and 836 cases and identified the 5' promoter SNP rs1478435 as having a significant association signal (uncorrectedPvalue: .00462; adjustedPvalue: .0319) in unrelated Caucasians. Allele T was over-represented in controls (OR = .75); T-carrier controls had decreased mRNA levels in nigral DA neurons, contributing to the reduced activity in the controls. In vitro functional analysis confirmed that T carriers displayed attenuated enhancement of promoter activity. These findings collectively suggest that increased nigralSLC6A3activity may be a risk factor for SCZ, and may help to explain high rates of comorbidity with substance abuse.