scholarly journals Characterization of metabolic compartmentalization in the liver using spatially resolved metabolomics

2021 ◽  
Author(s):  
Jiska van der Reest ◽  
Sylwia A Stopka ◽  
Walid M Abdelmoula ◽  
Daniela F Ruiz ◽  
Shakchhi Joshi ◽  
...  
Keyword(s):  
Cell Types ◽  
Pentose Phosphate ◽  
Nutrient Stress ◽  
Whole Body ◽  
Spatially Resolved ◽  
Metabolic Heterogeneity ◽  
Metabolomic Level ◽  
Transcriptomic Level ◽  
Tissue Specimens

Cells adapt their metabolism to physiological stimuli, and metabolic heterogeneity exists between  cell types, within tissues, and subcellular compartments. The liver plays an essential role in maintaining whole-body metabolic homeostasis and is structurally defined by metabolic zones. These zones are well-understood on the transcriptomic level, but have not been comprehensively characterized on the metabolomic level. Mass spectrometry imaging (MSI) can be used to map hundreds of metabolites directly from a tissue section, offering an important advance to investigate metabolic heterogeneity in tissues compared to extraction-based metabolomics methods that analyze tissue metabolite profiles in bulk. We established a workflow for the preparation of tissue specimens for matrix-assisted laser desorption/ionization (MALDI) MSI and achieved broad coverage of central carbon, nucleotide, and lipid metabolism pathways. We used this approach to visualize the effect of nutrient stress and excess on liver metabolism. Our data revealed a highly organized metabolic compartmentalization in livers, which becomes disrupted under nutrient stress conditions. Fasting caused changes in glucose metabolism and increased the levels of fatty acids in the circulation. In contrast, a prolonged high-fat diet (HFD) caused lipid accumulation within liver tissues with clear zonal patterns. Fatty livers had higher levels of purine and pentose phosphate related metabolites, which generates reducing equivalents to counteract oxidative stress. This MALDI MSI approach allowed the visualization of liver metabolic compartmentalization at high resolution and can be applied more broadly to yield new insights into metabolic heterogeneity in vivo .

scholarly journals Automated analysis of filopodial length and spatially resolved protein concentration via adaptive shape tracking

2016 ◽  
Vol 27 (22) ◽  
pp. 3616-3626 ◽  
Author(s):  
Tanumoy Saha ◽  
Isabel Rathmann ◽  
Abhiyan Viplav ◽  
Sadhana Panzade ◽  
Isabell Begemann ◽  
...  
Keyword(s):  
Protein Concentration ◽  
Growth Dynamics ◽  
Automated Analysis ◽  
Cell Types ◽  
Control Mechanisms ◽  
Spatially Resolved ◽  
Novel Approach ◽  
Associated Proteins

Filopodia are dynamic, actin-rich structures that transiently form on a variety of cell types. To understand the underlying control mechanisms requires precise monitoring of localization and concentration of individual regulatory and structural proteins as filopodia elongate and subsequently retract. Although several methods exist that analyze changes in filopodial shape, a software solution to reliably correlate growth dynamics with spatially resolved protein concentration along the filopodium independent of bending, lateral shift, or tilting is missing. Here we introduce a novel approach based on the convex-hull algorithm for parallel analysis of growth dynamics and relative spatiotemporal protein concentration along flexible filopodial protrusions. Detailed in silico tests using various geometries confirm that our technique accurately tracks growth dynamics and relative protein concentration along the filopodial length for a broad range of signal distributions. To validate our technique in living cells, we measure filopodial dynamics and quantify spatiotemporal localization of filopodia-associated proteins during the filopodial extension–retraction cycle in a variety of cell types in vitro and in vivo. Together these results show that the technique is suitable for simultaneous analysis of growth dynamics and spatiotemporal protein enrichment along filopodia. To allow readily application by other laboratories, we share source code and instructions for software handling.

scholarly journals Epithelial argininosuccinate synthetase is dispensable for intestinal regeneration and tumorigenesis

2021 ◽  
Vol 12 (10) ◽  
Author(s):  
Jonathan H. M. van der Meer ◽  
Ruben J. de Boer ◽  
Bartolomeus J. Meijer ◽  
Wouter L. Smit ◽  
Jacqueline L. M. Vermeulen ◽  
...  
Keyword(s):  
Amino Acid ◽  
Intestinal Epithelium ◽  
De Novo ◽  
Cell Types ◽  
Intestinal Epithelial ◽  
Argininosuccinate Synthetase ◽  
Important Amino Acid ◽  
Tissue Specimens ◽  
Colorectal Cancer Patients

AbstractThe epithelial signaling pathways involved in damage and regeneration, and neoplastic transformation are known to be similar. We noted upregulation of argininosuccinate synthetase (ASS1) in hyperproliferative intestinal epithelium. Since ASS1 leads to de novo synthesis of arginine, an important amino acid for the growth of intestinal epithelial cells, its upregulation can contribute to epithelial proliferation necessary to be sustained during oncogenic transformation and regeneration. Here we investigated the function of ASS1 in the gut epithelium during tissue regeneration and tumorigenesis, using intestinal epithelial conditional Ass1 knockout mice and organoids, and tissue specimens from colorectal cancer patients. We demonstrate that ASS1 is strongly expressed in the regenerating and Apc-mutated intestinal epithelium. Furthermore, we observe an arrest in amino acid flux of the urea cycle, which leads to an accumulation of intracellular arginine. However, loss of epithelial Ass1 does not lead to a reduction in proliferation or increase in apoptosis in vivo, also in mice fed an arginine-free diet. Epithelial loss of Ass1 seems to be compensated by altered arginine metabolism in other cell types and the liver.

scholarly journals Renal cell markers: lighthouses for managing renal diseases

2021 ◽  
Author(s):  
Shivangi Agarwal ◽  
Yashwanth R Sudhini ◽  
Onur K Polat ◽  
Jochen Reiser ◽  
Mehmet Mete Altintas
Keyword(s):  
High Efficiency ◽  
Imaging Techniques ◽  
Unmet Need ◽  
Cell Types ◽  
Whole Body ◽  
Renal Diseases ◽  
Cell Type ◽  
Cell Markers ◽  
Urine Production

Kidneys, one of the vital organs in our body, are responsible for maintaining whole-body homeostasis. The complexity of renal function (e.g., filtration, reabsorption, fluid and electrolyte regulation, urine production) demands diversity not only at the level of cell types but also in their overall distribution and structural framework within the kidney. To gain an in-depth molecular-level understanding of the renal system, it is imperative to discern the components of kidney and the types of cells residing in each of the sub-regions. Recent developments in labeling, tracing, and imaging techniques enabled us to mark, monitor and identify these cells in vivo with high efficiency in a minimally invasive manner. In this review, we have summarized different cell types, specific markers that are uniquely associated with those cell types, and their distribution in kidney, which altogether make kidneys so special and different. Cellular sorting based on the presence of certain proteins on the cell surface allowed for assignment of multiple markers for each cell type. However, different studies using different techniques have found contradictions in the cell-type specific markers. Thus, the term "cell marker" might be imprecise and sub-optimal, leading to uncertainty when interpreting the data. Therefore, we strongly believe that there is an unmet need to define the best cell markers for a cell type. Although, the compendium of renal-selective marker proteins presented in this review is a resource that may be useful to the researchers, we acknowledge that the list may not be necessarily exhaustive.

scholarly journals Homogentisic acid-derived pigment as a biocompatible label for optoacoustic imaging of macrophages

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Ina Weidenfeld ◽  
Christian Zakian ◽  
Peter Duewell ◽  
Andriy Chmyrov ◽  
Uwe Klemm ◽  
...  
Keyword(s):  
Single Cells ◽  
Cell Types ◽  
Homogentisic Acid ◽  
Tissue Imaging ◽  
Whole Body ◽  
Whole Body Imaging ◽  
Optoacoustic Imaging ◽  
Pigment Formation ◽  
Functionally Diverse

Abstract Macrophages are one of the most functionally-diverse cell types with roles in innate immunity, homeostasis and disease making them attractive targets for diagnostics and therapy. Photo- or optoacoustics could provide non-invasive, deep tissue imaging with high resolution and allow to visualize the spatiotemporal distribution of macrophages in vivo. However, present macrophage labels focus on synthetic nanomaterials, frequently limiting their ability to combine both host cell viability and functionality with strong signal generation. Here, we present a homogentisic acid-derived pigment (HDP) for biocompatible intracellular labeling of macrophages with strong optoacoustic contrast efficient enough to resolve single cells against a strong blood background. We study pigment formation during macrophage differentiation and activation, and utilize this labeling method to track migration of pro-inflammatory macrophages in vivo with whole-body imaging. We expand the sparse palette of macrophage labels for in vivo optoacoustic imaging and facilitate research on macrophage functionality and behavior.

scholarly journals Spatially Resolved Measurement of Dynamic Glucose Uptake in Live Ex Vivo Tissues

2020 ◽  
Author(s):  
Austin F. Dunn ◽  
Megan A. Catterton ◽  
Drake D. Dixon ◽  
Rebecca R. Pompano
Keyword(s):  
Lymph Node ◽  
T Cell ◽  
Glucose Uptake ◽  
Ex Vivo ◽  
Cell Types ◽  
Tissue Level ◽  
Slice Culture ◽  
Spatially Resolved ◽  
Glucose Analogue

ABSTRACTHighly proliferative cells depend heavily on glycolysis as a source of energy and biological precursor molecules, and glucose uptake is a useful readout of this aspect of metabolic activity. Glucose uptake is commonly quantified by using flow cytometry for cell cultures and positron emission tomography for organs in vivo. However, methods to detect spatiotemporally resolved glucose uptake in intact tissues are far more limited, particularly those that can quantify changes in uptake over time in specific tissue regions and cell types. Using lymph node metabolism as a case study, we developed a novel assay of dynamic and spatially resolved glucose uptake in living tissue by combining ex vivo tissue slice culture with a fluorescent glucose analogue. Live slices of murine lymph node were treated with the glucose analogue 2-[N-(7-nitrobenz-2-oxa-1,3-dia-xol-4-yl)amino]-2-deoxyglucose (2-NBDG). Incubation parameters were optimized to differentiate glucose uptake in activated versus naïve lymphocytes. Regional glucose uptake could be imaged at both the tissue level, by widefield microscopy, and at the cellular level, by confocal microscopy. Furthermore, the assay was readily multiplexed with live immunofluorescence labelling to generate maps of 2-NBDG uptake across tissue regions, revealing highest uptake in T cell-dense regions. The signal was predominantly intracellular and localized to lymphocytes rather than stromal cells. Finally, we demonstrated that the assay was repeatable in the same slices, and imaged the dynamic distribution of glucose uptake in response to ex vivo T cell stimulation for the first time. We anticipate that this assay will serve as a broadly applicable, user-friendly platform to quantify dynamic metabolic activities in complex tissue microenvironments.

scholarly journals Adipose-tissue derived signals control bone remodelling

2020 ◽  
Author(s):  
Maria-Bernadette Madel ◽  
He Fu ◽  
Dominique D. Pierroz ◽  
Mariano Schiffrin ◽  
Carine Winkler ◽  
...  
Keyword(s):  
Bone Erosion ◽  
Cell Formation ◽  
Cell Types ◽  
Whole Body ◽  
Long Bone ◽  
Bone Homeostasis ◽  
Multiple Cell ◽  
The One

SummaryLong bones from mammals host blood cell formation and contain multiple cell types, including adipocytes. Physiological functions of bone marrow adipocytes are poorly documented. Herein, we used adipocyte-deficient PPARγ-whole body null mice to investigate the consequence of total adipocyte deficiency on bone homeostasis in mice. We first highlight the dual bone phenotype of PPARγ null mice: on the one hand the increase bone formation and subsequent trabecularization extending in the long bone diaphysis, due to the well-known impact of PPARγ deficiency on osteoblasts formation and activity; on the other hand, an increased osteoclastogenesis in the cortical bone. We then further explore the cause of this unexpected increased osteoclastogenesis using two independent models of lipoatrophy, which recapitulated this phenotype. This demonstrates that hyperosteoclastogenesis is not intrinsically linked to PPARγ deficiency, but is a consequence of the total lipodystrophy. We further showed that adiponectin, a cytokine produced by adipocytes and mesenchymal stromal cells is a potent inhibitor of osteoclastogenesis in vitro and in vivo. Moreover, pharmacological activation of adiponectin receptors by the synthetic agonist AdipoRon inhibits mature osteoclast activity both in mouse and human cells by blocking podosome formation through AMPK activation. Finally, we demonstrated that AdipoRon treatment blocks bone erosion in vivo in a murine model of inflammatory bone loss, providing potential new approaches to treat osteoporosis.

Cytoarchitecture of the Xenopus thymus following gamma-irradiation

Development ◽  
1987 ◽  
Vol 100 (1) ◽  
pp. 95-105
Author(s):  
JH Russ ◽  
JD Horton
Keyword(s):  
Gamma Irradiation ◽  
Tolerance Induction ◽  
Cell Types ◽  
Whole Body ◽  
Thymic Stromal Cells ◽  
Normal Architecture

This paper describes in vitro and in vivo attempts to deplete the 4- to 8-month-old Xenopus laevis (J strain) thymus of its lymphocyte compartment. Gamma irradiation (2-3000 rad) of the excised thymus, followed by two weeks in organ culture, is effective in removing lymphocytes, but causes drastic reduction in size and loss of normal architecture. In contrast, in vivo whole-body irradiation (3000 rad) and subsequent in situ residence for 8-14 days proves successful in providing a lymphocyte-depleted froglet thymus without loss of cortical and medullary zones. In vivo-irradiated thymuses are about half normal size, lack cortical lymphocytes, but still retain some medullary thymocytes; they show no signs of lymphocyte regeneration when subsequently organ cultured for 2 weeks. Light microscopy of 1 micron, plastic-embedded sections and electron microscopy reveal that a range of thymic stromal cell types are retained and that increased numbers of cysts, mucous and myoid cells are found in the thymus following whole-body irradiation. In vivo-irradiated thymuses are therefore suitable for implantation studies exploring the role of thymic stromal cells in tolerance induction of differentiating T lymphocytes.

scholarly journals Decoding Stem Cells: An Overview on Planarian Stem Cell Heterogeneity and Lineage Progression

Biomolecules ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1532
Author(s):  
M. Dolores Molina ◽  
Francesc Cebrià
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Pluripotent Stem Cells ◽  
Current Knowledge ◽  
Large Population ◽  
Body Part ◽  
Cell Types ◽  
Whole Body ◽  
Unique System

Planarians are flatworms capable of whole-body regeneration, able to regrow any missing body part after injury or amputation. The extraordinary regenerative capacity of planarians is based upon the presence in the adult of a large population of somatic pluripotent stem cells. These cells, called neoblasts, offer a unique system to study the process of stem cell specification and differentiation in vivo. In recent years, FACS-based isolation of neoblasts, RNAi functional analyses as well as high-throughput approaches such as single-cell sequencing have allowed a rapid progress in our understanding of many different aspects of neoblast biology. Here, we summarize our current knowledge on the molecular signatures that define planarian neoblasts heterogeneity, which includes a percentage of truly pluripotent stem cells, and guide the commitment of pluripotent neoblasts into lineage-specific progenitor cells, as well as their differentiation into specific planarian cell types.

scholarly journals Mechanizmy śmierci od komórki do całego organizmu

2019 ◽  
Author(s):  
Sylwia Ciesielska
Keyword(s):  
Cell Death ◽  
Living Organism ◽  
Cell Types ◽  
In Vivo Studies ◽  
Whole Body ◽  
Natural Phenomenon ◽  
Human Organism ◽  
Living Organisms

In vitro studies are alternative for in vivo studies carried on living organisms. They involve cell populations for both normal and cancer cells. The processes inside cells might be base for defining whole body processes. Starting with fundamental unit of every living organism which is cell, we can distinguish two main types of cell death – apoptosis and necrosis. Human organism is built from 1013–1014 cells of 300 different cell types. During cell division new cells are created and their number is strictly controlled in programmed cell death – apoptosis. Mainly old or damaged cells commit suicide and are removed from organism. This is natural phenomenon and every change in mechanisms of proliferation or apoptosis cause changes and damage in whole organism. Homeostasis in organism depends on correct action of death and survival system. The patterns of equilibrium in nature relies on similar regulation profiles, in which it is similar to death of singular organisms in population or species. It implicates death as natural phenomenon maintaining balance in the world.

scholarly journals Tracking Radiolabeled Endothelial Microvesicles Predicts Their Therapeutic Efficacy: A Proof-of-Concept Study in Peripheral Ischemia Mouse Model Using SPECT/CT Imaging

Pharmaceutics ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 121
Author(s):  
Romain Giraud ◽  
Anaïs Moyon ◽  
Stéphanie Simoncini ◽  
Anne-Claire Duchez ◽  
Vincent Nail ◽  
...  
Keyword(s):  
Mouse Model ◽  
Cell Types ◽  
Ct Imaging ◽  
Whole Body ◽  
Peripheral Ischemia ◽  
Body Distribution ◽  
Hind Limbs ◽  
Oncologic Diseases ◽  
Administration Methods

Microvesicles, so-called endothelial large extracellular vesicles (LEVs), are of great interest as biological markers and cell-free biotherapies in cardiovascular and oncologic diseases. However, their therapeutic perspectives remain limited due to the lack of reliable data regarding their systemic biodistribution after intravenous administration. Methods: Applied to a mouse model of peripheral ischemia, radiolabeled endothelial LEVs were tracked and their in vivo whole-body distribution was quantified by microSPECT/CT imaging. Hindlimb perfusion was followed by LASER Doppler and motility impairment function was evaluated up to day 28 post-ischemia. Results: Early and specific homing of LEVs to ischemic hind limbs was quantified on the day of ischemia and positively correlated with reperfusion intensity at a later stage on day 28 after ischemia, associated with an improved motility function. Conclusions: This concept is a major asset for investigating the biodistribution of LEVs issued from other cell types, including cancer, thus partly contributing to better knowledge and understanding of their fate after injection.

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