Project description:Human in vivo skin wound: Non-wounded skin was obtained by taking punch biopsies from three healthy donors (donor 1,2 and 3). The samples were termed 'skin day 0 in vivo wound'. Skin wound samples were retrieved by making new punch biopsies from the edge of the original biopsies after four days. These samples were termed 'skin day 4 in vivo wound'. As much dermal tissue as possible was removed by dissection to make sure mainly epidermis was present in the samples. The samples were washed in NaCl to possible remove infiltrating inflammatory cells before RNA isolation. Ex vivo skin wounds: Skin was obtained from three healthy donors following reduction surgery (donor 1, 2, and 3). As much dermal tissue as possible was removed dissection. These samples were termed 'skin day 0 ex vivo wound'. Skin was sliced into 1x10 mm slices and incubated in keratinocyte medium for four days with either 1:1000 fold dilution of DMSO or 10 micromolar AG-1478 (dissolved in DMSO). Again as much dermal tissue was removed by dissection as possible before RNA was isolated. These samples were termed 'skin day 4 ex vivo wound' and 'skin day 4 AG-1478 ex vivo wound'. By comparing the gene expression day 4 in ex vivo wound with in vivo wounds it was possible to see which part of the gene expression in wounded skin that was due to the epidermal reaction to injury and how much was due to stimuli from infiltrating inflammatory cells absent in the ex vivo skin wounds. By comparing the data from ex vivo skin wounds day 4 with and without the EGFR-inhibitor AG-1478, it was possible to look at the importance of the EGF-receptor of EGFR for the gene expression in ex vivo wounded skin.
Project description:Therapeutic neo-vasculogenesis in vivo can be achieved by the co-transplantation of human endothelial colony-forming progenitor cells (ECFCs) with mesenchymal stem/progenitor cells (MSPCs).The underlying mechanism is not completely understood thus hampering the development of novel stem cell therapies.We hypothesized that proteomic profiling could be used to retrieve the in vivo signaling signature during the initial phase of human neo-vasculogenesis. ECFCs and MSPCs were therefore either transplanted alone or co-transplanted subcutaneously into immune deficient mice. Early cell signaling, occurring within the first 24 hours in vivo, was analyzed using antibody microarray proteomic profiling.Vessel formation and persistence were verified in parallel transplants for up to 24 weeks. Proteomic analysis revealed significant alteration of regulatory components including caspases, calcium/calmodulin-dependent protein kinase, DNA protein kinase,human ErbB2 receptor-tyrosine kinase as well as mitogen-activated protein kinases.Therapeutic candidate caspase-4 was selected from array results for targeting vascular network formation in vitro as well as modulating therapeutic vasculogenesis in vivo. As a proof-of-principle, caspase-4 and general caspase-blocking led to diminished endothelial network formation in vitro and significantly decreased vasculogenesis in vivo. Proteomic profiling ex vivo thus unraveled a signaling signature which can be targeted to modulate neo-vasculogenesis in vivo.
Project description:Proteomic analysis of cytokines in unstimulated oropharyngeal secretions. Epstein-barr virus (EBV) is a type 1 carcinogen which causes many cancers in humans. Here we explored the cytokine involvement of the EBV replication process in the oropharynx. Cytokine interactomic profiles were geneerated to understand the involved signalling pathways in HIV infected group and the healthy group. Proteome profilers were used to understand the major cytokine expression levels that are related to infection and immune regulation.
Project description:An ex-vivo human skin model was used to investigate the host skin response to M. sympodialis on oily (supplemented with oleic acid) and non-oily skin. Host-pathogen interactions were analysed by different molecular techniques including proteomics.
Project description:Low-flow push-pull perfusion is a sampling method that yields better spatial resolution than competitive methods like microdialysis. Because of the low flow rates used (50 nL/min), it is challenging to use this technique at high temporal resolution which requires methods of collecting, manipulating, and analyzing nanoliter samples. High temporal resolution also requires control of Taylor dispersion during sampling. To meet these challenges, push-pull perfusion was coupled with segmented flow to achieve in vivo sampling at 7 s temporal resolution at 50 nL/min flow rates. By further miniaturizing the probe inlet, sampling with 200 ms resolution at 30 nL/min (pull only) was demonstrated in vitro. Using this method, L-glutamate was monitored in the striatum of anesthetized rats. Up to 500 samples of 6 nL each were collected at 7 s intervals, segmented by an immiscible oil and stored in a capillary tube. The samples were assayed offline for L-glutamate at a rate of 15 samples/min by pumping them into a reagent addition tee fabricated from Teflon where reagents were added for a fluorescent enzyme assay. Fluorescence of the resulting plugs was monitored downstream. Microinjection of 70 mM potassium in physiological buffered saline evoked l-glutamate concentration transients that had an average maxima of 4.5 ± 1.1 ?M (n = 6 animals, 3-4 injections each) and rise times of 22 ± 2 s. These results demonstrate that low-flow push-pull perfusion with segmented flow can be used for high temporal resolution chemical monitoring and in complex biological environments.
Project description:Prospective study of accuracy of colonic polyp characterisation in vivo using high resolution white light endoscopy, narrow band imaging and chromoendoscopy.
Project description:Our understanding of adipose tissue biology has steadily evolved. While structural and energy storage functionalities have been in the forefront, a key endocrine role for adipocytes was revealed only over the last few decades. In contrast to the wealth of information on dynamic function of other endocrine tissues, few studies have focused on dynamic adipose tissue function or on tool development toward that end. Here, we apply our unique droplet-based microfluidic devices to culture, perfuse, and sample secretions from primary murine epididymal white adipose tissue (eWAT), and from predifferentiated clusters of 3T3-L1 adipocytes. Through automated control, oil-segmented aqueous droplets (∼2.6 nL) were sampled from tissue or cells at 3.5 second temporal resolution (including sample and reference droplets), with integrated enzyme assays enabling real-time quantification of glycerol (down to 1.9 fmol per droplet). This high resolution revealed previously unreported oscillations in secreted glycerol at frequencies of 0.2 to 2.0 min-1 (∼30-300 s periods) present in the primary tissue but not in clustered cells. Low-level bursts (∼50 fmol) released in basal conditions were contrasted with larger bursts (∼300 fmol) during stimulation. Further, both fold changes and burst magnitudes were decreased in eWAT of aged and obese mice. These results, combined with immunostaining and photobleaching analyses, suggest that gap-junctional coupling or nerve cell innervation within the intact ex vivo tissue explants play important roles in this apparent tissue-level, lipolytic synchronization. High-resolution, quantitative sampling by droplet microfluidics thus permitted unique biological information to be observed, giving an analytical framework poised for future studies of dynamic oscillatory function of adipose and other tissues.
Project description:Skin samples collected from underarm w/ PDMS for 30 seconds. Samples used for optimization of GC headspace methodology wrt desorption time, cryofocusing, and size of PDMS patch (10mL vials were used).