scholarly journals Leukotriene B4 Is a Major Determinant of Leukocyte Recruitment During Otitis Media

2021 ◽  
Vol 11 ◽  
Author(s):  
Kyung Wook Heo ◽  
Kwang Pak ◽  
Arwa Kurabi ◽  
Allen F. Ryan
Keyword(s):  
Otitis Media ◽  
Inflammatory Responses ◽  
Gene Array ◽  
Cell Types ◽  
Leukotriene B4 ◽  
Specific Cell ◽  
Leukocyte Infiltration ◽  
Mucosal Hyperplasia ◽  
Different Cell Types ◽  
Ltb4 Receptor

BackgroundPathogens of otitis media (OM) induce inflammatory responses in the middle ear (ME), characterized by mucosal hyperplasia, leukocyte infiltration, and inflammatory mediators, including arachidonic acid metabolites. We studied the role of the eicosanoid leukotriene B4 (LTB4) in OM.MethodsExpression of LTB4-related genes was evaluated by gene array and single-cell RNA-Seq in MEs infected with nontypeable Haemophilus influenzae (NTHi). An inhibitor of LTB4 receptor 1 (i.e. U75302) was also used to block LTB4 responses.ResultsME expression of LTB4-related genes was observed by gene arrays and scRNA-Seq. However, not all genes involved in LTB4 generation occurred in any one specific cell type. Moreover, LTB4 receptor inhibition significantly reduced mucosal hyperplasia and virtually eliminated leukocyte infiltration.ConclusionsME expression of LTB4-related genes suggest a functional role in OM disease. The fact that LTB4-generation is spread across different cell types is consistent with a transcellular pathway of eicosanoid biosynthesis involving cell-to-cell signaling as well as transfer of biosynthetic intermediates between cells. The dramatic reduction in ME leukocyte infiltration caused by U75302 indicates that LTB4 plays a major role in ME inflammatory cell recruitment, acting via the LTB4R1 receptor. Given that there are many other chemotactic factors that occur in the ME during OM, the ability of LTB4 to activate leukocytes and stimulate their extravasation may explain the effects of inhibition. Reduction in mucosal hyperplasia due to U75302 administration may be secondary to the reduction in leukocytes since LTB4R1 is not expressed by mucosal epithelial or stromal cells. The results suggest that LTB4 receptor antagonists could be useful in treating OM.

A novel metabolic pathway for leukotriene B4 in different cell types: primary reduction of a double bond

1987 ◽  
Vol 922 (3) ◽  
pp. 337-344 ◽  
Author(s):  
Volkhard Kaever ◽  
Michael Martin ◽  
Joachim Fauler ◽  
Karl-Heinz Marx ◽  
Klaus Resch
Keyword(s):  
Double Bond ◽  
Metabolic Pathway ◽  
Cell Types ◽  
Leukotriene B4 ◽  
Primary Reduction ◽  
Different Cell Types

scholarly journals Dissecting cell-type-specific metabolism in pancreatic ductal adenocarcinoma

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Allison N Lau ◽  
Zhaoqi Li ◽  
Laura V Danai ◽  
Anna M Westermark ◽  
Alicia M Darnell ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Heterogeneous Systems ◽  
Cell Types ◽  
Ductal Adenocarcinoma ◽  
Specific Cell ◽  
Isolated Cells ◽  
Pancreatic Cancer Cells ◽  
Turn Over ◽  
Different Cell Types

Tumors are composed of many different cell types including cancer cells, fibroblasts, and immune cells. Dissecting functional metabolic differences between cell types within a mixed population can be challenging due to the rapid turnover of metabolites relative to the time needed to isolate cells. To overcome this challenge, we traced isotope-labeled nutrients into macromolecules that turn over more slowly than metabolites. This approach was used to assess differences between cancer cell and fibroblast metabolism in murine pancreatic cancer organoid-fibroblast co-cultures and tumors. Pancreatic cancer cells exhibited increased pyruvate carboxylation relative to fibroblasts, and this flux depended on both pyruvate carboxylase and malic enzyme 1 activity. Consequently, expression of both enzymes in cancer cells was necessary for organoid and tumor growth, demonstrating that dissecting the metabolism of specific cell populations within heterogeneous systems can identify dependencies that may not be evident from studying isolated cells in culture or bulk tissue.

Cytokine release from innate immune cells: association with diverse membrane trafficking pathways

Blood ◽  
2011 ◽  
Vol 118 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Paige Lacy ◽  
Jennifer L. Stow
Keyword(s):  
Membrane Trafficking ◽  
Immune Cells ◽  
Inflammatory Responses ◽  
Cell Types ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Cytokine Release ◽  
Research Findings ◽  
Specific Receptors ◽  
Different Cell Types

AbstractCytokines released from innate immune cells play key roles in the regulation of the immune response. These intercellular messengers are the source of soluble regulatory signals that initiate and constrain inflammatory responses to pathogens and injury. Although numerous studies describe detailed signaling pathways induced by cytokines and their specific receptors, there is little information on the mechanisms that control the release of cytokines from different cell types. Indeed, the pathways, molecules, and mechanisms of cytokine release remain a “black box” in immunology. Here, we review research findings and new approaches that have begun to generate information on cytokine trafficking and release by innate immune cells in response to inflammatory or infectious stimuli. Surprisingly complex machinery, multiple organelles, and specialized membrane domains exist in these cells to ensure the selective, temporal, and often polarized release of cytokines in innate immunity.

scholarly journals ProtAnno, an Automated Cell Type Annotation Tool for Single Cell Proteomics Data that Integrates Information from Multiple Reference Sources

2021 ◽  
Author(s):  
Wenxuan Deng ◽  
Biqing Zhu ◽  
Seyoung Park ◽  
Tomokazu S. Sumida ◽  
Avraham Unterman ◽  
...  
Keyword(s):  
Single Cell ◽  
Single Cells ◽  
Earth Metal ◽  
Cell Types ◽  
Specific Cell ◽  
Cell Type ◽  
Proteomics Data ◽  
Data Annotation ◽  
Different Cell Types ◽  
Unique Molecular Identifier

Compared with sequencing-based global genomic profiling, cytometry labels targeted surface markers on millions of cells in parallel either by conjugated rare earth metal particles or Unique Molecular Identifier (UMI) barcodes. Correct annotation of these cells to specific cell types is a key step in the analysis of these data. However, there is no computational tool that automatically annotates single cell proteomics data for cell type inference. In this manuscript, we propose an automated single cell proteomics data annotation approach called ProtAnno to facilitate cell type assignments without laborious manual gating. ProtAnno is designed to incorporate information from annotated single cell RNA-seq (scRNA-seq), CITE-seq, and prior data knowledge (which can be imprecise) on biomarkers for different cell types. We have performed extensive simulations to demonstrate the accuracy and robustness of ProtAnno. For several single cell proteomics datasets that have been manually labeled, ProtAnno was able to correctly label most single cells. In summary, ProtAnno offers an accurate and robust tool to automate cell type annotations for large single cell proteomics datasets, and the analysis of such annotated cell types can offer valuable biological insights.

scholarly journals The Endocannabinoid System in Glial Cells and Their Profitable Interactions to Treat Epilepsy: Evidence from Animal Models

2021 ◽  
Vol 22 (24) ◽  
pp. 13231
Author(s):  
Jon Egaña-Huguet ◽  
Edgar Soria-Gómez ◽  
Pedro Grandes
Keyword(s):  
Glial Cells ◽  
Endocannabinoid System ◽  
Cell Types ◽  
Specific Cell ◽  
Neuronal Viability ◽  
Wide Range ◽  
Novel Target ◽  
Different Cell Types ◽  
The Impact

Epilepsy is one of the most common neurological conditions. Yearly, five million people are diagnosed with epileptic-related disorders. The neuroprotective and therapeutic effect of (endo)cannabinoid compounds has been extensively investigated in several models of epilepsy. Therefore, the study of specific cell-type-dependent mechanisms underlying cannabinoid effects is crucial to understanding epileptic disorders. It is estimated that about 100 billion neurons and a roughly equal number of glial cells co-exist in the human brain. The glial population is in charge of neuronal viability, and therefore, their participation in brain pathophysiology is crucial. Furthermore, glial malfunctioning occurs in a wide range of neurological disorders. However, little is known about the impact of the endocannabinoid system (ECS) regulation over glial cells, even less in pathological conditions such as epilepsy. In this review, we aim to compile the existing knowledge on the role of the ECS in different cell types, with a particular emphasis on glial cells and their impact on epilepsy. Thus, we propose that glial cells could be a novel target for cannabinoid agents for treating the etiology of epilepsy and managing seizure-like disorders.

scholarly journals Filopodia rotate and coil by actively generating twist in their actin shaft

2020 ◽  
Author(s):  
Natascha Leijnse ◽  
Younes Barooji ◽  
Bram Verhagen ◽  
Lena Wullkopf ◽  
Janine Erler ◽  
...  
Keyword(s):  
Cell Types ◽  
Narrow Channel ◽  
Eukaryotic Cell ◽  
General Mechanism ◽  
Specific Cell ◽  
Filamentous Actin ◽  
Cell Matrix ◽  
Matrix Interactions ◽  
Cell Matrix Interactions ◽  
Different Cell Types

Abstract Filopodia are actin-rich structures, present on the surface of practically every known eukaryotic cell. These structures play a pivotal role in specific cell-cell and cell-matrix interactions by allowing cells to explore their environment, generate mechanical forces, perform chemical signaling, or convey signals via intercellular tunneling nano-bridges. The dynamics of filopodia appear quite complex as they exhibit a rich behavior of buckling, pulling, length and shape changes. Here, we find that filopodia additionally explore their 3D extracellular space by combining growth and shrinking with axial twisting and buckling of their actin rich core. Importantly, we show the rotational dynamics of the filamentous actin inside filopodia for a range of highly distinct and cognate cell types spanning from earliest development to highly differentiated tissue cells. Non-equilibrium physical modeling of actin and myosin confirm that twist, and hence rotation, is an emergent phenomenon of active filaments confined in a narrow channel which points to a generic mechanism present in all cells. Our measurements confirm that filopodia exert traction forces and form helical buckles in a range of different cell types that can be ascribed to accumulation of sufficient twist. These results lead us to conclude that activity induced twisting of the actin shaft is a general mechanism underlying fundamental functions of filopodia

scholarly journals Structure of the heterophilic interaction between the nectin-like 4 and nectin-like 1 molecules

2019 ◽  
Vol 116 (6) ◽  
pp. 2068-2077 ◽  
Author(s):  
Xiao Liu ◽  
Tai An ◽  
Dongdong Li ◽  
Zheng Fan ◽  
Pan Xiang ◽  
...  
Keyword(s):  
Neural Development ◽  
Dorsal Root ◽  
Binding Assay ◽  
Cell Types ◽  
Specific Cell ◽  
Protein Binding Assay ◽  
Dimerization Interface ◽  
Different Cell Types ◽  
Structural Characterizations ◽  
Selection Of

Nectin-like (Necl) molecules are Ca2+-independent Ig-like transmembrane cell adhesion molecules that participate in junctions between different cell types. The specific cell–cell adhesions mediated by Necl proteins are important in neural development and have been implicated in neurodegenerative diseases. Here, we present the crystal structure of the mouse Necl-4 full ectodomain and the structure of the heterophilic Necl ectodomain complex formed by the mNecl-4 and mNecl-1 ectodomains. We demonstrate that, while the ectodomain of mNecl-4 is monomeric, it forms a stable heterodimer with Ig1 of mNecl-1, with an affinity significantly higher than that observed for self-dimerization of the mNecl-1 ectodomain. We validated our structural characterizations by performing a surface plasmon resonance assay and an Fc fusion protein binding assay in mouse primary dorsal root ganglia neurites and Schwann cells and identified a selection of residues important for heterophilic interactions. Finally, we proposed a model of Necl binding specificity that involves an induced-fit conformational change at the dimerization interface.

scholarly journals Single-Cell Sequencing Applications in the Inner Ear

2021 ◽  
Vol 9 ◽  
Author(s):  
Mingxuan Wu ◽  
Mingyu Xia ◽  
Wenyan Li ◽  
Huawei Li
Keyword(s):  
Gene Expression ◽  
Single Cell ◽  
Inner Ear ◽  
Signaling Pathways ◽  
Cell Types ◽  
Specific Cell ◽  
Tissue Heterogeneity ◽  
Single Cell Sequencing ◽  
Cell Groups ◽  
Different Cell Types

Genomics studies face specific challenges in the inner ear due to the multiple types and limited amounts of inner ear cells that are arranged in a very delicate structure. However, advances in single-cell sequencing (SCS) technology have made it possible to analyze gene expression variations across different cell types as well as within specific cell groups that were previously considered to be homogeneous. In this review, we summarize recent advances in inner ear research brought about by the use of SCS that have delineated tissue heterogeneity, identified unknown cell subtypes, discovered novel cell markers, and revealed dynamic signaling pathways during development. SCS opens up new avenues for inner ear research, and the potential of the technology is only beginning to be explored.

Inhibition of SFRP1 Reduces Severity of Periodontitis

2007 ◽  
Vol 86 (9) ◽  
pp. 873-877 ◽  
Author(s):  
C.H. Li ◽  
S. Amar
Keyword(s):  
Inflammatory Cell ◽  
Inflammatory Responses ◽  
Inflammatory Cells ◽  
Cell Types ◽  
Inflammatory Cell Infiltrate ◽  
Periodontal Tissues ◽  
Periodontal Breakdown ◽  
Common Infectious Disease ◽  
Apoptosis Assay ◽  
Different Cell Types

Porphyromonas gingivalis ( P. gingivalis) is implicated as a major pathogen in periodontitis, a common infectious disease characterized by the inflammation and destruction of periodontal tissues. Secreted frizzled-related protein 1 (SFRP1) modulates apoptosis in different cell types. To characterize the roles of SFRP1 in periodontitis, we used a P. gingivalis-induced murine periodontitis model. Inflammatory responses were measured by morphometric and histomorphometric analysis, apoptosis assay, and immunohistochemistry. We found that P. gingivalis-infected mouse periodontal tissues expressed significantly more SFRP1 compared with those of control mice. Also, in P. gingivalis-infected animals, more apoptosis of inflammatory cells, fibroblasts, and bone-lining cells was observed compared with controls. Antibody experiments aimed at inhibiting SFRP1 expression in periodontitis resulted in a reduction of periodontal breakdown, inflammatory cell infiltrate, osteoclastogenesis, and apoptosis of inflammatory cells and fibroblasts. The results of our studies suggest that SFRP1 may be involved in the development of periodontitis, since inhibiting SFRP1 resulted in reduced periodontal breakdown.

scholarly journals 3D bioprinting of hepatocytes: core–shell structured co-cultures with fibroblasts for enhanced functionality

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rania Taymour ◽  
David Kilian ◽  
Tilman Ahlfeld ◽  
Michael Gelinsky ◽  
Anja Lode
Keyword(s):  
Cell Types ◽  
In Vitro Models ◽  
Core Shell ◽  
Specific Cell ◽  
Cellular Interactions ◽  
Culture Models ◽  
Vitro Model ◽  
And Function ◽  
Different Cell Types

AbstractWith the aim of understanding and recapitulating cellular interactions of hepatocytes in their physiological microenvironment and to generate an artificial 3D in vitro model, a co-culture system using 3D extrusion bioprinting was developed. A bioink based on alginate and methylcellulose (algMC) was first shown to be suitable for bioprinting of hepatocytes; the addition of Matrigel to algMC enhanced proliferation and morphology of them in monophasic scaffolds. Towards a more complex system that allows studying cellular interactions, we applied core–shell bioprinting to establish tailored 3D co-culture models for hepatocytes. The bioinks were specifically functionalized with natural matrix components (based on human plasma, fibrin or Matrigel) and used to co-print fibroblasts and hepatocytes in a spatially defined, coaxial manner. Fibroblasts acted as supportive cells for co-cultured hepatocytes, stimulating the expression of certain biomarkers of hepatocytes like albumin. Furthermore, matrix functionalization positively influenced both cell types in their respective compartments by enhancing their adhesion, viability, proliferation and function. In conclusion, we established a functional co-culture model with independently tunable compartments for different cell types via core–shell bioprinting. This provides the basis for more complex in vitro models allowing co-cultivation of hepatocytes with other liver-specific cell types to closely resemble the liver microenvironment.

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