scholarly journals High Resolution Imaging Mass Spectrometry of Bacterial Microcolonies at Ecological Scales

2019 ◽  
Author(s):  
Rita de Cassia Pessotti ◽  
Bridget L. Hansen ◽  
Vineetha M. Zacharia ◽  
Daniel Polyakov ◽  
Matthew F. Traxler
Keyword(s):  
Small Groups ◽  
Chemical Exchange ◽  
Streptomyces Coelicolor ◽  
Imaging Mass Spectrometry ◽  
Bacterial Cells ◽  
Chemical Gradients ◽  
Ecological Scales ◽  
Maldi Ims ◽  
Resolution Imaging ◽  
Physiological Gradients

AbstractMicrobes interact with the world around them at the chemical level. However, directly examining the chemical exchange between microbes, and microbes and their environment, at ecological scales, i.e. the scale of a single bacterial cell or small groups of cells, remains a key challenge. Here we address this obstacle by presenting a methodology that enables Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) of bacterial microcolonies. By combining optimized sample preparation with sub-atmospheric pressure MALDI, we demonstrate that chemical output from groups of as few as ~50 cells can be visualized with MALDI-IMS. Application of this methodology to Bacillus subtilis and Streptomyces coelicolor revealed heterogeneity in chemical output across microcolonies, and asymmetrical metabolite production when cells grew within physiological gradients produced by Medicago sativa roots. Taken together, these results indicate that MALDI-IMS can readily visualize metabolites made by very small assemblages of bacterial cells, and that even these small groups of cells can differentially produce metabolites in response to local chemical gradients.

scholarly journals Next-generation protein analysis in the pathology department

2019 ◽  
Vol 73 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Melek Ahmed ◽  
Glenn Broeckx ◽  
Geert Baggerman ◽  
Karin Schildermans ◽  
Patrick Pauwels ◽  
...  
Keyword(s):  
Personalised Medicine ◽  
Correct Diagnosis ◽  
Mrna Level ◽  
Imaging Mass Spectrometry ◽  
Tissue Analysis ◽  
Therapeutic Decision ◽  
Promising Technique ◽  
Maldi Ims ◽  
Specific Proteins ◽  
Molecular Information

Traditionally, immunohistochemistry (IHC) is used by pathologists to localise specific proteins or peptides in tissue slides. In the era of personalised medicine, however, molecular tissue analysis becomes indispensable for correct diagnosis, prognosis and therapeutic decision, not only on the DNA or mRNA level but also on the protein level. Combining molecular information with imaging presents many advantages. Therefore, matrix-assisted laser desorption/ionisation imaging mass spectrometry (MALDI IMS) is a promising technique to be added to the armamentarium of the pathologist. Here, we focus on the workflow, advantages and drawbacks of both MALDI IMS and IHC. We also briefly discuss a few other protein imaging modalities and give examples of applications.

Methods for Human Olfactory Bulb Tissue Studies Using Peptide/Protein MALDI-TOF Imaging Mass Spectrometry (MALDI-IMS)

2017 ◽  
pp. 91-106 ◽  
Author(s):  
Ibon Iloro ◽  
Joaquín Fernández-Irigoyen ◽  
Iraide Escobes ◽  
Mikel Azkargorta ◽  
Enrique Santamaría ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Olfactory Bulb ◽  
Imaging Mass Spectrometry ◽  
Maldi Tof ◽  
Maldi Ims

scholarly journals Chemical Exchange at the Trinuclear Copper Center of Small Laccase from Streptomyces coelicolor

2020 ◽  
Vol 119 (1) ◽  
pp. 9-14
Author(s):  
Rubin Dasgupta ◽  
Karthick B.S.S. Gupta ◽  
Faezeh Nami ◽  
Huub J.M. de Groot ◽  
Gerard W. Canters ◽  
...  
Keyword(s):  
Chemical Exchange ◽  
Streptomyces Coelicolor ◽  
Copper Center

scholarly journals Discovery of Prognostic Markers for Early-Stage High-Grade Serous Ovarian Cancer by Maldi-Imaging

Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2000
Author(s):  
Hagen Kulbe ◽  
Oliver Klein ◽  
Zhiyang Wu ◽  
Eliane T. Taube ◽  
Wanja Kassuhn ◽  
...  
Keyword(s):  
Roc Analysis ◽  
Operating Characteristic ◽  
Prognostic Markers ◽  
Early Stage ◽  
Imaging Mass Spectrometry ◽  
Maldi Imaging ◽  
High Grade ◽  
Proof Of Concept ◽  
Tissue Sections ◽  
Maldi Ims

With regard to relapse and survival, early-stage high-grade serous ovarian (HGSOC) patients comprise a heterogeneous group and there is no clear consensus on first-line treatment. Currently, no prognostic markers are available for risk assessment by standard targeted immunohistochemistry and novel approaches are urgently required. Here, we applied MALDI-imaging mass spectrometry (MALDI-IMS), a new method to identify distinct mass profiles including protein signatures on paraffin-embedded tissue sections. In search of prognostic biomarker candidates, we compared proteomic profiles of primary tumor sections from early-stage HGSOC patients with either recurrent (RD) or non-recurrent disease (N = 4; each group) as a proof of concept study. In total, MALDI-IMS analysis resulted in 7537 spectra from the malignant tumor areas. Using receiver operating characteristic (ROC) analysis, 151 peptides were able to discriminate between patients with RD and non-RD (AUC > 0.6 or < 0.4; p < 0.01), and 13 of them could be annotated to proteins. Strongest expression levels of specific peptides linked to Keratin type1 and Collagen alpha-2(I) were observed and associated with poor prognosis (AUC > 0.7). These results confirm that in using IMS, we could identify new candidates to predict clinical outcome and treatment extent for patients with early-stage HGSOC.

scholarly journals High-resolution imaging mass spectrometry combined with transcriptomic analysis identified a link between fatty acid composition of phosphatidylinositols and the immune checkpoint pathway at the primary tumour site of breast cancer

2019 ◽  
Vol 122 (2) ◽  
pp. 245-257 ◽  
Author(s):  
Masahiro Kawashima ◽  
Mariko Tokiwa ◽  
Tomomi Nishimura ◽  
Yukiko Kawata ◽  
Masahiro Sugimoto ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Mass Spectrometry ◽  
Fatty Acid ◽  
Cancer Cells ◽  
Immune Checkpoint ◽  
Imaging Mass Spectrometry ◽  
Invasive Cancer ◽  
Fatty Acid Binding ◽  
Checkpoint Pathway ◽  
Maldi Ims

Abstract Background The fatty acid (FA) composition of phosphatidylinositols (PIs) is tightly regulated in mammalian tissue since its disruption impairs normal cellular functions. We previously found its significant alteration in breast cancer by using matrix-assisted laser desorption and ionisation imaging mass spectrometry (MALDI-IMS). Methods We visualised the histological distribution of PIs containing different FAs in 65 primary breast cancer tissues using MALDI-IMS and investigated its association with clinicopathological features and gene expression profiles. Results Normal ductal cells (n = 7) predominantly accumulated a PI containing polyunsaturated FA (PI-PUFA), PI(18:0/20:4). PI(18:0/20:4) was replaced by PIs containing monounsaturated FA (PIs-MUFA) in all non-invasive cancer cells (n = 12). While 54% of invasive cancer cells (n = 27) also accumulated PIs-MUFA, 46% of invasive cancer cells (n = 23) accumulated the PIs-PUFA, PI(18:0/20:3) and PI(18:0/20:4). The accumulation of PI(18:0/20:3) was associated with higher incidence of lymph node metastasis and activation of the PD-1-related immune checkpoint pathway. Fatty acid-binding protein 7 was identified as a putative molecule controlling PI composition. Conclusions MALDI-IMS identified PI composition associated with invasion and nodal metastasis of breast cancer. The accumulation of PI(18:0/20:3) could affect the PD-1-related immune checkpoint pathway, although its precise mechanism should be further validated.

scholarly journals Bidirectional C and N transfer and a potential role for sulfur in an epiphytic diazotrophic mutualism

2020 ◽  
Vol 14 (12) ◽  
pp. 3068-3078
Author(s):  
Rhona K. Stuart ◽  
Eric R. A. Pederson ◽  
Philip D. Weyman ◽  
Peter K. Weber ◽  
Ulla Rassmussen ◽  
...  
Keyword(s):  
Boreal Forests ◽  
Imaging Mass Spectrometry ◽  
Targeted Mutagenesis ◽  
Carbon And Nitrogen ◽  
Nitrogen Inputs ◽  
Resolution Imaging ◽  
Diazotrophic Cyanobacteria ◽  
C And N ◽  
Material Exchange ◽  
Nutritional Mutualism

Abstract In nitrogen-limited boreal forests, associations between feathermoss and diazotrophic cyanobacteria control nitrogen inputs and thus carbon cycling, but little is known about the molecular regulators required for initiation and maintenance of these associations. Specifically, a benefit to the cyanobacteria is not known, challenging whether the association is a nutritional mutualism. Targeted mutagenesis of the cyanobacterial alkane sulfonate monooxygenase results in an inability to colonize feathermosses by the cyanobacterium Nostoc punctiforme, suggesting a role for organic sulfur in communication or nutrition. Isotope probing paired with high-resolution imaging mass spectrometry (NanoSIMS) demonstrated bidirectional elemental transfer between partners, with carbon and sulfur both being transferred to the cyanobacteria, and nitrogen transferred to the moss. These results support the hypothesis that moss and cyanobacteria enter a mutualistic exosymbiosis with substantial bidirectional material exchange of carbon and nitrogen and potential signaling through sulfur compounds.

scholarly journals Method for high-resolution imaging of creatine in vivo using chemical exchange saturation transfer

2013 ◽  
Vol 71 (1) ◽  
pp. 164-172 ◽  
Author(s):  
Feliks Kogan ◽  
Mohammad Haris ◽  
Anup Singh ◽  
Kejia Cai ◽  
Catherine Debrosse ◽  
...  
Keyword(s):  
High Resolution ◽  
Chemical Exchange ◽  
Chemical Exchange Saturation Transfer ◽  
High Resolution Imaging ◽  
Saturation Transfer ◽  
Resolution Imaging
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