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Microspectroscopic techniques such as Fourier transform infrared (FTIR) have played an important role in "fingerprinting" the biochemical composition of cellular components. Based on structure and function, complex biomolecules absorb energy in the mid-infrared (lambda = 2-20 microm) yielding characteristic vibrational infrared (IR) spectra. However, optical detection FTIR microspectroscopy may not be suitable for IR-absorbing sample materials. Photothermal microspectroscopy (PTMS) permits the direct measurement of heat generated as a result of sample material absorbing radiation. This approach generates true absorption spectra and is implemented by interfacing a scanning probe microscope and an FTIR spectrometer. Detection is performed using a near-field ultra-miniaturized temperature sensor. Employing PTMS, IR spectra of MCF-7 cells were examined in spectral regions (900-2000 cm(-1)) corresponding to proteins, DNA, RNA, glycoproteins, carbohydrates, lipids, and levels of protein phosphorylation. As a cell passes through the cell cycle, its nuclear material decondenses and condenses and this has led to ambiguity as to whether the intensity of such spectral regions may be associated with the G(1)-, S- or G(2)-phases of the cell cycle. Cultured cells were tracked over a time course known to correspond to marked alterations in cell-cycle distributions, as determined using flow cytometry. Experiments were carried out in the absence or presence of lindane, a pesticide known to induce G(1)-arrest in MCF-7 cells. Significant (P < 0.05) elevations in spectral intensities were associated with exponentially growing cell populations, predominantly in S-phase or G(2)-phase, compared to more quiescent populations predominantly in G(1)-phase. Increases in the absorption band at 970 cm(-1), associated with elevated protein phosphorylation, were observed in vibrational spectra of exponentially growing cell populations compared to those exhibiting a slowing in their growth kinetics. These results seem to suggest that intracellular bulk changes, associated with transit through the cell cycle, can be tracked using PTMS. 相似文献
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Azzedine Fercha Anna Laura Capriotti Giuseppe Caruso Chiara Cavaliere Serena Stampachiacchiere Riccardo Zenezini Chiozzi Aldo Laganà 《Proteomics》2016,16(10):1537-1546
Seed imbibition and radicle emergence are generally less affected by salinity in soybean than in other crop plants. In order to unveil the mechanisms underlying this remarkable salt tolerance of soybean at seed germination, a comparative label‐free shotgun proteomic analysis of embryonic axes exposed to salinity during germination sensu stricto (GSS) was conducted. The results revealed that the application of 100 and 200 mmol/L NaCl stress was accompanied by significant changes (>2‐fold, P<0.05) of 97 and 75 proteins, respectively. Most of these salt‐responsive proteins (70%) were classified into three major functional categories: disease/defense response, protein destination and storage and primary metabolism. The involvement of these proteins in salt tolerance of soybean was discussed, and some of them were suggested to be potential salt‐tolerant proteins. Furthermore, our results suggest that the cross‐protection against aldehydes, oxidative as well as osmotic stress, is the major adaptive response to salinity in soybean. 相似文献
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Infrared spectroscopy with multivariate analysis potentially facilitates the segregation of different types of prostate cell 下载免费PDF全文
German MJ Hammiche A Ragavan N Tobin MJ Cooper LJ Matanhelia SS Hindley AC Nicholson CM Fullwood NJ Pollock HM Martin FL 《Biophysical journal》2006,90(10):3783-3795
The prostate gland is conventionally divided into zones or regions. This morphology is of clinical significance as prostate cancer (CaP) occurs mainly in the peripheral zone (PZ). We obtained tissue sets consisting of paraffin-embedded blocks of cancer-free transition zone (TZ) and PZ and adjacent CaP from patients (n = 6) who had undergone radical retropubic prostatectomy; a seventh tissue set of snap-frozen PZ and TZ was obtained from a CaP-free gland removed after radical cystoprostatectomy. Paraffin-embedded tissue slices were sectioned (10-mum thick) and mounted on suitable windows to facilitate infrared (IR) spectra acquisition before being dewaxed and air dried; cryosections were dessicated on BaF(2) windows. Spectra were collected employing synchrotron Fourier-transform infrared (FTIR) microspectroscopy in transmission mode or attenuated total reflection-FTIR (ATR) spectroscopy. Epithelial cell and stromal IR spectra were subjected to principal component analysis to determine whether wavenumber-absorbance relationships expressed as single points in "hyperspace" might on the basis of multivariate distance reveal biophysical differences between cells in situ in different tissue regions. After spectroscopic analysis, plotted clusters and their loadings curves highlighted marked variation in the spectral region containing DNA/RNA bands ( approximately 1490-1000 cm(-1)). By interrogating the intrinsic dimensionality of IR spectra in this small cohort sample, we found that TZ epithelial cells appeared to align more closely with those of CaP while exhibiting marked structural differences compared to PZ epithelium. IR spectra of PZ stroma also suggested that these cells are structurally more different to CaP than those located in the TZ. Because the PZ exhibits a higher occurrence of CaP, other factors (e.g., hormone exposure) may modulate the growth kinetics of initiated epithelial cells in this region. The results of this pilot study surprisingly indicate that TZ epithelial cells are more likely to exhibit what may be a susceptibility-to-adenocarcinoma spectral signature. Thus, IR spectroscopy on its own may not be sufficient to identify premalignant prostate epithelial cells most likely to progress to CaP. 相似文献
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Mustafa A. Salih Emeline Mundwiller Arif O. Khan Abdulmajeed AlDrees Salah A. Elmalik Hamdy H. Hassan Mohammed Al-Owain Hisham M. S. Alkhalidi Istvan Katona Mohammad M. Kabiraj Roman Chrast Amal Y. Kentab Hamad Alzaidan Richard J. Rodenburg Thomas M. Bosley Joachim Weis Michel Koenig Giovanni Stevanin Hamid Azzedine 《PloS one》2013,8(10)
Mutations in PLA2G6 gene have variable phenotypic outcome including infantile neuroaxonal dystrophy, atypical neuroaxonal dystrophy, idiopathic neurodegeneration with brain iron accumulation and Karak syndrome. The cause of this phenotypic variation is so far unknown which impairs both genetic diagnosis and appropriate family counseling. We report detailed clinical, electrophysiological, neuroimaging, histologic, biochemical and genetic characterization of 11 patients, from 6 consanguineous families, who were followed for a period of up to 17 years. Cerebellar atrophy was constant and the earliest feature of the disease preceding brain iron accumulation, leading to the provisional diagnosis of a recessive progressive ataxia in these patients. Ultrastructural characterization of patients’ muscle biopsies revealed focal accumulation of granular and membranous material possibly resulting from defective membrane homeostasis caused by disrupted PLA2G6 function. Enzyme studies in one of these muscle biopsies provided evidence for a relatively low mitochondrial content, which is compatible with the structural mitochondrial alterations seen by electron microscopy. Genetic characterization of 11 patients led to the identification of six underlying PLA2G6 gene mutations, five of which are novel. Importantly, by combining clinical and genetic data we have observed that while the phenotype of neurodegeneration associated with PLA2G6 mutations is variable in this cohort of patients belonging to the same ethnic background, it is partially influenced by the genotype, considering the age at onset and the functional disability criteria. Molecular testing for PLA2G6 mutations is, therefore, indicated in childhood-onset ataxia syndromes, if neuroimaging shows cerebellar atrophy with or without evidence of iron accumulation. 相似文献
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Dimicoli-Salazar S Bulle F Yacia A Massé JM Fichelson S Vigon I 《Biology of the cell / under the auspices of the European Cell Biology Organization》2011,103(11):531-542
Background information. The identification of a source of stem cells able to regenerate skeletal muscle was the goal of numerous studies with the aim to develop new therapeutic approaches for genetic muscle diseases or muscle injuries. A series of studies have demonstrated that stem cells derived from various tissues may have a role in the regeneration of damaged muscles, but this contribution is always very weak. Thus we established a project aiming to reprogramme non‐muscle cells into the skeletal striated differentiation pathway. Results. We transduced several human primary adult stem or progenitor cells using a recombinant lentivirus containing the coding sequence of the Myf5 gene considered as a master gene for the determination of skeletal striated muscle. These original results are the first demonstration of a myogenic conversion of human mesenchymal and endothelial cells by Myf5. Conclusions. The procedure described in the present paper could be used to develop new research protocols with the prospect of using these cells as therapeutic agents. 相似文献
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Abouzahr-Rifai S Hasmim M Boukerche H Hamelin J Janji B Jalil A Kieda C Mami-Chouaib F Bertoglio J Chouaib S 《The Journal of biological chemistry》2008,283(46):31665-31672
Tumor cells evade adaptive immunity by a variety of mechanisms, including selection of variants that are resistant to specific cytotoxic T lymphocyte (CTL) pressure. Recently, we have reported that the reorganization of the actin cytoskeleton can be used by tumor cells as a strategy to promote their resistance to CTL-mediated lysis. In this study, we further examined the functional features of a CTL-resistant tumor variant and investigated the relationship between cytoskeleton alteration, the acquisition of tumor resistance to CTL-induced cell death, Rho-GTPases, and focal adhesion kinase (FAK) pathways. Our data indicate that although the resistant cells do not display an increased migratory potential, an alteration of adhesion to the extracellular matrix was observed. When Rho-GTPases were activated in cells by the bacterial CNF1 (cytotoxic necrotizing factor 1), striking changes in the cell morphology, including actin cytoskeleton, focal adhesions, and membrane extensions, were observed. More importantly, such activation also resulted in a significant attenuation of resistance to CTL-induced cell death. Furthermore, we demonstrate that FAK signaling pathways were constitutively defective in the resistant cells. Silencing of FAK in the sensitive target cells resulted in the inhibition of immune synapse formation with specific CTLs and their subsequent lysis. Expression of the FAK mutant (Y397F) resulted in an inhibition of IGR-Heu cell adhesion and of their susceptibility to specific lysis. These results suggest that FAK activation plays a role in the control of tumor cell susceptibility to CTL-mediated lysis. 相似文献
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Djaffar Kheffache Hind Guemmour Azzedine Dekhira Ahmed Benaboura Ourida Ouamerali 《Journal of molecular modeling》2013,19(11):4837-4847
In the present work, we carried out a conformational analysis of cis-3-aminoindan-1-ol and evaluated the role of the intramolecular hydrogen bond in the stabilization of various conformers using quantum mechanical DFT (B3LYP) and MP2 methods. On the basis of relative energies, we have found nine conformational minima, which can interchange through the ring-puckering and the internal rotation of the OH and NH2 groups on the five-membered ring. The intramolecular hydrogen bonds such as OH????π, NH????π, NH????OH and HN????HO are expected to be of critical importance for the conformational stabilities. The intramolecular interactions of the minima have been analyzed by calculation of electron density (ρ) and Laplacian (ρ) at the bond critical points (BCPs) using atoms-in-molecule (AIM) theory. The existence or absence of OH????π and NH????π in cis-3-aminoindan-1-ol remains unclear since the geometrical investigation has not been confirmed by topological criteria. The results of theoretical calculations demonstrate that this compound exists predominantly in one ring-puckering form stabilized by strong hydrogen bond HN????HO Interaction. 相似文献
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Lily Mijouin Mélanie Hillion Yasmina Ramdani Thomas Jaouen Cécile Duclairoir-Poc Marie-Laure Follet-Gueye Elian Lati Florent Yvergnaux Azzedine Driouich Luc Lefeuvre Christine Farmer Laurent Misery Marc G. J. Feuilloley 《PloS one》2013,8(11)