Optical microscopy to study the role of cytoskeleton in cell locomotion and virus trafficking

3. General conclusions 150 The interest in optical microscopy is constanly growing, mainly because of its unique features in examining biological systems in four dimensions (x-y-z-t)1 . The work presented here was focused on biological applications of optical microscopy by exploring and improving the spatial and temporal resolution performances and by futher developing optical tools for manipulating biological samples. First, I studied the resolution performances of the system in the three dimensional space and I contributed in improving the experimental spatial resolution of microscope by applying deconvolution. In this respect, theoretical modelling can characterize the image formation process of the microscope, but only experimental measurement of the PSF can quantify the limitations of the real system. Indeed, experimental PSF presents shape assymetry due to spherical aberrations introduced by optical elements, while theoretical PSF is symmetric and account only for the resolution limits of an ideal imaging system. The disadvantage of experimental PSF is that could be corrupted by noise, otherwise deconvolution with the theoretical PSF offer only a qualitative improvement of the image, because the introduced artefacts cannot be quantified. Deconvolution of the acquired data with experimental PSF...3. General conclusions 150 The interest in optical microscopy is constanly growing, mainly because of its unique features in examining biological systems in four dimensions (x-y-z-t)1 . The work presented here was focused on biological applications of optical microscopy by exploring and improving the spatial and temporal resolution performances and by futher developing optical tools for manipulating biological samples. First, I studied the resolution performances of the system in the three dimensional space and I contributed in improving the experimental spatial resolution of microscope by applying deconvolution. In this respect, theoretical modelling can characterize the image formation process of the microscope, but only experimental measurement of the PSF can quantify the limitations of the real system. Indeed, experimental PSF presents shape assymetry due to spherical aberrations introduced by optical elements, while theoretical PSF is symmetric and account only for the resolution limits of an ideal imaging system. The disadvantage of experimental PSF is that could be corrupted by noise, otherwise deconvolution with the theoretical PSF offer only a qualitative improvement of the image, because the introduced artefacts cannot be quantified. Deconvolution of the acquired data with experimental PSF...Department of Genetics and MicrobiologyKatedra genetiky a mikrobiologieFaculty of SciencePřírodovědecká fakult

Microscopy Conference 2017 (MC 2017) - Proceedings

Das Dokument enthält die Kurzfassungen der Beiträge aller Teilnehmer an der Mikroskopiekonferenz "MC 2017", die vom 21. bis 25.08.2017, in Lausanne stattfand

Dichotomic role of NAADP/two-pore channel 2/Ca2+ signaling in regulating neural differentiation of mouse embryonic stem cells

Poster Presentation - Stem Cells and Pluripotency: abstract no. 1866The mobilization of intracellular Ca2+stores is involved in diverse cellular functions, including cell proliferation and differentiation. At least three endogenous Ca2+mobilizing messengers have been identified, including inositol trisphosphate (IP3), cyclic adenosine diphosphoribose (cADPR), and nicotinic adenine acid dinucleotide phosphate (NAADP). Similar to IP3, NAADP can mobilize calcium release in a wide variety of cell types and species, from plants to animals. Moreover, it has been previously shown that NAADP but not IP3-mediated Ca2+increases can potently induce neuronal differentiation in PC12 cells. Recently, two pore channels (TPCs) have been identified as a novel family of NAADP-gated calcium release channels in endolysosome. Therefore, it is of great interest to examine the role of TPC2 in the neural differentiation of mouse ES cells. We found that the expression of TPC2 is markedly decreased during the initial ES cell entry into neural progenitors, and the levels of TPC2 gradually rebound during the late stages of neurogenesis. Correspondingly, perturbing the NAADP signaling by TPC2 knockdown accelerates mouse ES cell differentiation into neural progenitors but inhibits these neural progenitors from committing to the final neural lineage. Interestingly, TPC2 knockdown has no effect on the differentiation of astrocytes and oligodendrocytes of mouse ES cells. Overexpression of TPC2, on the other hand, inhibits mouse ES cell from entering the neural lineage. Taken together, our data indicate that the NAADP/TPC2-mediated Ca2+signaling pathway plays a temporal and dichotomic role in modulating the neural lineage entry of ES cells; in that NAADP signaling antagonizes ES cell entry to early neural progenitors, but promotes late neural differentiation.postprin

Microscopy Conference 2017 (MC 2017) - Proceedings

Das Dokument enthält die Kurzfassungen der Beiträge aller Teilnehmer an der Mikroskopiekonferenz "MC 2017", die vom 21. bis 25.08.2017, in Lausanne stattfand

Microscopy Conference 2021 (MC 2021) - Proceedings

Das Dokument enthält die Kurzfassungen der Beiträge aller Teilnehmer an der Mikroskopiekonferenz "MC 2021"

Life Sciences Program Tasks and Bibliography for FY 1997

This document includes information on all peer reviewed projects funded by the Office of Life and Microgravity Sciences and Applications, Life Sciences Division during fiscal year 1997. This document will be published annually and made available to scientists in the space life sciences field both as a hard copy and as an interactive internet web page