Сравнительная оценка экспрессии молекул главного комплекса гистосовместимости в тканях пародонта и периферической крови больных генерализованным пародонтитом

Проведено порівняльні клініко-іммунологічні аналізи стану адгезивних молекул HLA-A, B, C і HLA-DR головного комплексу гістосумісності на місцевому рівні - в тканинах пародонта і периферичної крові хворих на ГП і відповідних антигенів моноклональних антитіл T і В-лімфоцитів. Не виявлено прямого кореляційного зв’язку між клінічним проявом запалення пародонту і загальносоматичним імунним статусом, що розкриває механізми локальних Т-клітинних характеристик імунних змін і зумовлює корекцію місцевої терапії.A comparative clinical and immunological analysis of adhesion molecules HLA-A, B, C and HLA-DR major histocompatibility complex at the local level - in periodontal tissues and peripheral blood of patients with SE and related antigen antibody monoklialnyh T and B lymphocytes. There were no direct connection between korellyatsionnoy clinical manifestation of periodontal inflammation and the immune status of the somatic, that reveals the mechanisms of local T-cell characteristics of the immune changes and determines the correction of local therapy

ToF-SIMS parallel imaging MS/MS of lipid species in thin tissue sections

Unambiguous identification of detected species is essential in complex biomedical samples. To date, there are not many mass spectrometry imaging techniques that can provide both high spatial resolution and identification capabilities. A new and patented imaging tandem mass spectrometer, exploiting the unique characteristics of the nanoTOF II (Physical Electronics, USA) TOF-SIMS TRIFT instrument, was developed to address this. Tandem mass spectrometry is based on the selection of precursor ions from the full secondary ion spectrum (MS1), followed by energetic activation and fragmentation, and collection of the fragment ions to obtain a tandem MS spectrum (MS2). The PHI NanoTOF II mass spectrometer is equipped with a high-energy collision induced dissociation (CID) fragmentation cell as well as a second time-of-flight analyzer developed for simultaneous ToF-SIMS and tandem MS imaging experiments. We describe here the results of a ToF-SIMS imaging experiment on a thin tissue section of an infected zebrafish as a model organism for tuberculosis. The focus is on the obtained ion distribution plot of a fatty acid as well as its identification by tandem mass spectrometry

Identification and High-Resolution Imaging of alpha-Tocopherol from Human Cells to Whole Animals by TOF-SIMS Tandem Mass Spectrometry

A unique method for identification of biomolecular components in different biological specimens, while preserving the capability for high speed 2D and 3D molecular imaging, is employed to investigate cellular response to oxidative stress. The employed method enables observing the distribution of the antioxidant α-tocopherol and other molecules in cellular structures via time-of-flight secondary ion mass spectrometry (TOF-SIMS (MS1)) imaging in parallel with tandem mass spectrometry (MS2) imaging, collected simultaneously. The described method is employed to examine a network formed by neuronal cells differentiated from human induced pluripotent stem cells (iPSCs), a model for investigating human neurons in vitro. The antioxidant α-tocopherol is identified in situ within different cellular layers utilizing a 3D TOF-SIMS tandem MS imaging analysis. As oxidative stress also plays an important role in mediating inflammation, the study was expanded to whole body tissue sections of M. marinum-infected zebrafish, a model organism for tuberculosis. The TOF-SIMS tandem MS imaging results reveal an increased presence of α-tocopherol in response to the pathogen

Mass Spectrometry Imaging of Drug Related Crystal-Like Structures in Formalin-Fixed Frozen and Paraffin-Embedded Rabbit Kidney Tissue Sections

A multimodal mass spectrometry imaging (MSI) based approach was used to characterize the molecular content of crystal-like structures in a frozen and paraffin embedded piece of a formalin-fixed rabbit kidney. Matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF) imaging and desorption electrospray ionization (DESI) mass spectrometry imaging were combined to analyze the frozen and paraffin embedded sample without further preparation steps to remove the paraffin. The investigated rabbit kidney was part of a study on a drug compound in development, in which severe renal toxicity was observed in dosed rabbits. Histological examination of the kidney showed tubular degeneration with precipitation of crystal-like structures in the cortex, which were assumed to cause the renal toxicity. The MS imaging approach was used to find out whether the crystal-like structures were composed of the drug compound, metabolites, or an endogenous compound as a reaction to the drug administration. The generated MALDI-MSI data were analyzed using principal component analysis. In combination with the MS/MS results, this way of data processing demonstrates that the crystal structures were mainly composed of metabolites and relatively little parent drug. [Figure: see text

Characterization of lipidic markers of chondrogenic differentiation using mass spectrometry imaging

Mesenchymal stem cells (MSC) are an interesting alternative for cell-based therapy of cartilage defects attributable to their capacity to differentiate toward chondrocytes in the process termed chondrogenesis. The metabolism of lipids has recently been associated with the modulation of chondrogenesis and also with the development of pathologies related to cartilage degeneration. Information about the distribution and modulation of lipids during chondrogenesis could provide a panel of putative chondrogenic markers. Thus, the discovery of new lipid chondrogenic markers could be highly valuable for improving MSC-based cartilage therapies. In this work, MS imaging was used to characterize the spatial distribution of lipids in human bone marrow MSCs during the first steps of chondrogenic differentiation. The analysis of MSC micromasses at days 2 and 14 of chondrogenesis by MALDI-MSI led to the identification of 20 different lipid species, including fatty acids, sphingolipids, and phospholipids. Phosphocholine, several sphingomyelins, and phosphatidylcholines were found to increase during the undifferentiated chondrogenic stage. A particularly detected lipid profile was verified by TOF secondary ion MS. Using this technology, a higher intensity of phosphocholine-related ions was observed in the peripheral region of the micromasses collected at day 14

Efficient functionalization of additives at supramolecular material surfaces

Selective surface modification reactions can be performed on additives that are supramolecularly incorporated into supramolecular materials. Hereby, processing of the material, that regularly requires harsh processing conditions (i.e., the use of organic solvents and/or high temperatures), and functionalization can be decoupled. Moreover, high-resolution depth profiling by time-of-flight (ToF) secondary-ion mass spectrometry clearly shows distinct differences in surface and bulk material composition

Multimodal Spectroscopic Study of Amyloid Fibril Polymorphism

Amyloid fibrils are a large class of self-assembled protein aggregates that are formed from unstructured peptides and unfolded proteins. The fibrils are characterized by a universal β-sheet core stabilized by hydrogen bonds, but the molecular structure of the peptide subunits exposed on the fibril surface is variable. Here we show that multimodal spectroscopy using a range of bulk- and surface-sensitive techniques provides a powerful way to dissect variations in the molecular structure of polymorphic amyloid fibrils. As a model system, we use fibrils formed by the milk protein β-lactoglobulin, whose morphology can be tuned by varying the protein concentration during formation. We investigate the differences in the molecular structure and composition between long, straight fibrils versus short, wormlike fibrils. We show using mass spectrometry that the peptide composition of the two fibril types is similar. The overall molecular structure of the fibrils probed with various bulk-sensitive spectroscopic techniques shows a dominant contribution of the β-sheet core but no difference in structure between straight and wormlike fibrils. However, when probing specifically the surface of the fibrils with nanometer resolution using tip-enhanced Raman spectroscopy (TERS), we find that both fibril types exhibit a heterogeneous surface structure with mainly unordered or α-helical structures and that the surface of long, straight fibrils contains markedly more β-sheet structure than the surface of short, wormlike fibrils. This finding is consistent with previous surface-specific vibrational sum-frequency generation (VSFG) spectroscopic results (VandenAkker et al. J. Am. Chem. Soc., 2011, 133, 18030−18033, DOI: 10.1021/ja206513r). In conclusion, only advanced vibrational spectroscopic techniques sensitive to surface structure such as TERS and VSFG are able to reveal the difference in structure that underlies the distinct morphology and rigidity of different amyloid fibril polymorphs that have been observed for a large range of food and disease-related proteins