scholarly journals Expression of α2-macroglobulin by the interaction between hepatocytes and endothelial cells in coculture

1998 ◽  
Vol 275 (1) ◽  
pp. R203-R211
Author(s):  
Mark A. Talamini ◽  
Michael P. McCluskey ◽  
Timothy G. Buchman ◽  
Antonio De Maio
Keyword(s):  
Endothelial Cells ◽  
Ex Vivo ◽  
Apparent Molecular Weight ◽  
Rat Hepatocytes ◽  
Cell Types ◽  
Hepatic Function ◽  
Cellular Interactions ◽  
Ex Vivo Model ◽  
Extracellular Medium ◽  
Isolated Rat Hepatocytes

The interaction between distinct cell types within the liver seems to be important in regulating hepatic function. However, these interactions have not been well characterized because of difficulty in reproducing the hepatic environment in an ex vivo model. In the present study a coculture system of hepatocytes and endothelial cells was established to investigate the communication between parenchymal and nonparenchymal cells. Freshly isolated rat hepatocytes were placed onto a monolayer of primary aortic rat endothelial cells. Analysis of the proteins secreted into the extracellular medium after pulse labeling with radioactive amino acids revealed the presence of a 180,000-apparent molecular weight glycoprotein, BBB-180, which was not detected in the extracellular medium of hepatocytes or endothelial cells when they were cultured separately. This glycoprotein was identified as α2-macroglobulin after sequencing of the proteolytic peptides derived from the purified protein. This finding was confirmed by Northern and Western blotting, immunoprecipitation, and RT-PCR. The expression of α2-macroglobulin required direct contact between hepatocytes and viable endothelial cells. These findings suggest that endothelial cells modulate hepatocyte gene expression by direct cellular interactions.

scholarly journals Comparative metabolism of the antiviral dimer 3'-azido-3'-deoxythymidine-P-2',3'-dideoxyinosine and the monomers zidovudine and didanosine by rat, monkey, and human hepatocytes.

1997 ◽  
Vol 41 (11) ◽  
pp. 2502-2510 ◽  
Author(s):  
X R Pan-Zhou ◽  
E Cretton-Scott ◽  
X J Zhou ◽  
M Y Xie ◽  
R Rahmani ◽  
...  
Keyword(s):  
High Performance ◽  
Rat Hepatocytes ◽  
Human Hepatocytes ◽  
Metabolic Fate ◽  
Extracellular Medium ◽  
Isolated Rat Hepatocytes ◽  
Cell Extracts ◽  
Comparative Metabolism ◽  
Isolated Rat

AZT-P-ddI is an antiviral heterodimer composed of one molecule of 3'-azido-3'-deoxythymidine (AZT) and one molecule of 2',3'-dideoxyinosine (ddI) linked through their 5' positions by a phosphate bond. The metabolic fate of the dimer was studied with isolated rat, monkey, and human hepatocytes and was compared with that of its component monomers AZT and ddI. Upon incubation of double-labeled [14C]AZT-P-[3H]ddI in freshly isolated rat hepatocytes in suspension at a final concentration of 10 microM, the dimer was taken up intact by cells and then rapidly cleaved to AZT, AZT monophosphate, ddI, and ddI monophosphate. AZT and ddI so formed were then subject to their respective catabolisms. High-performance liquid chromatography analyses of the extracellular medium and cell extracts revealed the presence of unchanged dimer, AZT, 3'-azido-3'-deoxy-5'-beta-D-glucopyranosylthymidine (GAZT), 3'-amino-3'-deoxythymidine (AMT), ddI, and a previously unrecognized derivative of the dideoxyribose moiety of ddI, designated ddI-M. Trace extracellular but substantial intracellular levels of the glucuronide derivative of AMT (3'-amino-3'-deoxy-5'-beta-D-glucopyranosylthymidine [GAMT]) were also detected. Moreover, the extent of the formation of AMT, GAZT, and ddI-M from the dimer was markedly lower than that with AZT and ddI alone by the hepatocytes. With hepatocytes in primary culture obtained from rat, monkey, and human, large interspecies variations in the metabolism of AZT-P-ddI were observed. While GAZT and ddI-M, metabolites of AZT and ddI, respectively, as well as AZT 5'-monophosphate (MP) and ddI-MP were detected in the extracellular media of all species, AMT and GAMT were produced only by rat and monkey hepatocytes. No such metabolites were formed by human hepatocytes. The metabolic fate of the dimer by human hepatocytes was consistent with in vivo data recently obtained from human immunodeficiency virus-infected patients.

scholarly journals EFFECT OF MURRAYA KOENIGII LEAVES EXTRACT ON GLUCONEOGENESIS AND GLYCOGENOLYSIS IN ISOLATED RAT HEPATOCYTES CULTURE

2018 ◽  
Vol 11 (11) ◽  
pp. 264
Author(s):  
Rohan S Phatak ◽  
Chitra C Khanwelkar ◽  
Kailas D Datkhile ◽  
Pratik P Durgawale
Keyword(s):  
Glycogen Content ◽  
Ex Vivo ◽  
Rat Hepatocytes ◽  
Diabetic Rats ◽  
Murraya Koenigii ◽  
Isolated Rat Hepatocytes ◽  
Genes Expression ◽  
Different Doses ◽  
Isolated Rat

Objectives: The present study was aimed to investigate the in vitro activity of Murraya koenigii extracts through various carbohydrate metabolic pathways in the isolated rat hepatocyte models.Methods: Different doses of metformin, aqueous and methanol extracts of M. koenigii leaves were evaluated in the MTT, glucose, and glycogen content assays in the cultured in vitro rat hepatocytes.Results: The study showed that there was a significant increase in activity with respect to the increased concentration of extracts. Slight effect was observed in the isolated rat hepatocytes culture, M. koenigii leaves extract may exert cytoprotective and hypoglycemic action.Conclusion: It may be needed to determine the effect of ex vivo rat hepatocytes isolated from diabetic rats. Effects of the plant or isolated compounds on the genes expression of signaling pathways should be investigated in further studies.

scholarly journals Construction of 3D Cellular Composites with Stem Cells Derived from Adipose Tissue and Endothelial Cells by Use of Optical Tweezers in a Natural Polymer Solution

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1759 ◽  
Author(s):  
Takehiro Yamazaki ◽  
Toshifumi Kishimoto ◽  
Paweł Leszczyński ◽  
Koichiro Sadakane ◽  
Takahiro Kenmotsu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Endothelial Cells ◽  
Adipose Tissue ◽  
Optical Tweezers ◽  
Single Cells ◽  
Three Dimensional ◽  
Cell Types ◽  
Cellular Interactions ◽  
Research Fields ◽  
Wide Range

To better understand the regulation and function of cellular interactions, three-dimensional (3D) assemblies of single cells and subsequent functional analysis are gaining popularity in many research fields. While we have developed strategies to build stable cellular structures using optical tweezers in a minimally invasive state, methods for manipulating a wide range of cell types have yet to be established. To mimic organ-like structures, the construction of 3D cellular assemblies with variety of cell types is essential. Our recent studies have shown that the presence of nonspecific soluble polymers in aqueous solution is the key to creating stable 3D cellular assemblies efficiently. The present study further expands on the construction of 3D single cell assemblies using two different cell types. We have successfully generated 3D cellular assemblies, using GFP-labeled adipose tissue-derived stem cells and endothelial cells by using optical tweezers. Our findings will support the development of future applications to further characterize cellular interactions in tissue regeneration.

scholarly journals MT1-MMP–dependent neovessel formation within the confines of the three-dimensional extracellular matrix

2004 ◽  
Vol 167 (4) ◽  
pp. 757-767 ◽  
Author(s):  
Tae-Hwa Chun ◽  
Farideh Sabeh ◽  
Ichiro Ota ◽  
Hedwig Murphy ◽  
Kevin T. McDonagh ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Cell Surface ◽  
Type I Collagen ◽  
Ex Vivo ◽  
Three Dimensional ◽  
Collagenolytic Activity ◽  
Type I ◽  
Ex Vivo Model

During angiogenesis, endothelial cells initiate a tissue-invasive program within an interstitial matrix comprised largely of type I collagen. Extracellular matrix–degradative enzymes, including the matrix metalloproteinases (MMPs) MMP-2 and MMP-9, are thought to play key roles in angiogenesis by binding to docking sites on the cell surface after activation by plasmin- and/or membrane-type (MT) 1-MMP–dependent processes. To identify proteinases critical to neovessel formation, an ex vivo model of angiogenesis has been established wherein tissue explants from gene-targeted mice are embedded within a three-dimensional, type I collagen matrix. Unexpectedly, neither MMP-2, MMP-9, their cognate cell-surface receptors (i.e., β3 integrin and CD44), nor plasminogen are essential for collagenolytic activity, endothelial cell invasion, or neovessel formation. Instead, the membrane-anchored MMP, MT1-MMP, confers endothelial cells with the ability to express invasive and tubulogenic activity in a collagen-rich milieu, in vitro or in vivo, where it plays an indispensable role in driving neovessel formation.

scholarly journals TFAM-deficient mouse skin fibroblasts: an ex vivo model of mitochondrial dysfunction

2021 ◽  
Author(s):  
Manuel J. Del Rey ◽  
Carolina Meroño ◽  
Cristina Municio ◽  
Alicia Usategui ◽  
María Mittelbrunn ◽  
...  
Keyword(s):  
Mitochondrial Dysfunction ◽  
Ex Vivo ◽  
Stress Test ◽  
Critical Role ◽  
Substantial Reduction ◽  
Mouse Skin ◽  
Cell Types ◽  
Ex Vivo Model ◽  
Primary Mouse ◽  
Inflammatory Phenotype

Mitochondrial dysfunction in different cell types is associated to several pathological processes and potentially contributes to chronic inflammatory and ageing-related diseases. Mitochondrial Transcription Factor A (TFAM) plays a critical role in maintaining mtDNA integrity and function. Taking advantage of the Tfamfl/fl UBC-Cre/ERT2+/+ mice, we sought to develop a cellular in vitro system to investigate the role of mitochondrial dysfunction in the stromal cell component. We describe an inducible model of mitochondrial dysfunction by stable depletion of TFAM in primary mouse skin fibroblast (SK-FB) after 4-hydroxytamoxifen (4-OHT) administration. Tfam gene deletion caused a sustained reduction of Tfam and mtDNA-encoded mRNA expression in Cre(+) cultured for low (LP) and high passages (HP). Ultimately, Tfam knockout translated into a loss of TFAM protein. TFAM depletion led to a substantial reduction of the mitochondrial respiratory chain (MRC) complexes that was exacerbated in HP SK-FB cultures. The assembly pattern showed that the respiratory complexes fail to reach the respirasome in 4-OHT Cre(+) SK-FB. Functionally, we determined the mitochondrial function and the glycolytic activity by mito-stress and glycolysis-stress test respectively. These analysis showed that mitochondrial dysfunction was developed after long-term 4-OHT treatment in HP Cre(+) SK-FB and was compensated by an increase in the glycolytic capacity. Finally, expression analysis revealed that 4-OHT-treated HP Cre(+) SK-FB showed a senescent and pro-inflammatory phenotype. In conclusion, we have generated and validated the first ex vivo model of fibroblast mitochondrial dysfunction that results in a pro-inflammatory phenotype applicable to explore this process in other cell types in a variety of pathological conditions.

scholarly journals Interleukin-6 actions in the hypothalamus protects against obesity and is involved in the regulation of neurogenesis

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Vanessa C. Bobbo ◽  
Daiane F. Engel ◽  
Carlos Poblete Jara ◽  
Natalia F. Mendes ◽  
Roberta Haddad-Tovolli ◽  
...  
Keyword(s):  
Gene Expression ◽  
Interleukin 6 ◽  
Ex Vivo ◽  
Cell Types ◽  
Cell Labeling ◽  
Specific Cell ◽  
Related Gene ◽  
Sequencing Data ◽  
Ex Vivo Model ◽  
Diet Induced Obesity

Abstract Background Interleukin-6 (IL6) produced in the context of exercise acts in the hypothalamus reducing obesity-associated inflammation and restoring the control of food intake and energy expenditure. In the hippocampus, some of the beneficial actions of IL6 are attributed to its neurogenesis-inducing properties. However, in the hypothalamus, the putative neurogenic actions of IL6 have never been explored, and its potential to balance energy intake can be an approach to prevent or attenuate obesity. Methods Wild-type (WT) and IL6 knockout (KO) mice were employed to study the capacity of IL6 to induce neurogenesis. We used cell labeling with Bromodeoxyuridine (BrdU), immunofluorescence, and real-time PCR to determine the expression of markers of neurogenesis and neurotransmitters. We prepared hypothalamic neuroprogenitor cells from KO that were treated with IL6 in order to provide an ex vivo model to further characterizing the neurogenic actions of IL6 through differentiation assays. In addition, we analyzed single-cell RNA sequencing data and determined the expression of IL6 and IL6 receptor in specific cell types of the murine hypothalamus. Results IL6 expression in the hypothalamus is low and restricted to microglia and tanycytes, whereas IL6 receptor is expressed in microglia, ependymocytes, endothelial cells, and astrocytes. Exogenous IL6 reduces diet-induced obesity. In outbred mice, obesity-resistance is accompanied by increased expression of IL6 in the hypothalamus. IL6 induces neurogenesis-related gene expression in the hypothalamus and in neuroprogenitor cells, both from WT as well as from KO mice. Conclusion IL6 induces neurogenesis-related gene expression in the hypothalamus of WT mice. In KO mice, the neurogenic actions of IL6 are preserved; however, the appearance of new fully differentiated proopiomelanocortin (POMC) and neuropeptide Y (NPY) neurons is either delayed or disturbed.

Regulation by cannabinoid receptors of anandamide transport across the blood-brain barrier and through other endothelial cells

2006 ◽  
Vol 95 (01) ◽  
pp. 117-127 ◽  
Author(s):  
Anna Fiori ◽  
Monica Bari ◽  
Filippo Granata ◽  
Valeria Gasperi ◽  
M. De Stefano ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Cannabinoid Receptors ◽  
Ex Vivo ◽  
Acid Amide ◽  
Brain Barrier ◽  
No Production ◽  
Ex Vivo Model ◽  
Subsequent Increase ◽  
Blood Brain

SummaryThe endocannabinoid anandamide (AEA) has many neurovascular activities. However, it is not yet clear how AEA can be metabolized at the neurovascular interface, and how it can move through the vascular and the cerebral compartments. The results reported in this article show that isolated bovine brain microvessels, an ex vivo model of the blood-brain barrier, have detectable levels of endogenous AEA and possess the biochemical machinery to bind and metabolize it, i. e. type-1 and type-2 cannabinoid receptors (CB1R and CB2R), a selective AEA membrane transporter (AMT), an AEA-degrading fatty acid amide hydrolase, and the AEA-synthesizing enzymes N-acyltransferase and N-acyl-phosphatidylethanolamines-specific phospholipase D. We also show that activation of CB1R enhances AMT activity through increased nitric oxide synthase (NOS) activity and subsequent increase of NO production. AMT activity is instead reduced by activation of CB2R, which inhibits NOS and NO release. In addition, binding experiments and immunoelectronmicroscopy demonstrate that different endothelial cells vary in the expression of CB1R and CB2R on the luminal and/or abluminal sides. The different localization of CBRs can lead to a diverse effect on AMT activity on the luminal and abluminal membranes, suggesting that the distribution of these receptors may drive AEA directional transport through the blood-brain barrier and other endothelial cells.

scholarly journals Studying Heterotypic Cell–Cell Interactions in the Human Brain Using Pluripotent Stem Cell Models for Neurodegeneration

Cells ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 299 ◽  
Author(s):  
Liqing Song ◽  
Yuanwei Yan ◽  
Mark Marzano ◽  
Yan Li
Keyword(s):  
Stem Cells ◽  
Endothelial Cells ◽  
Human Brain ◽  
Neurodegenerative Disease ◽  
Disease Progression ◽  
Cell Types ◽  
Neural Cells ◽  
Cellular Interactions ◽  
Induced Pluripotent

Human cerebral organoids derived from induced pluripotent stem cells (iPSCs) provide novel tools for recapitulating the cytoarchitecture of the human brain and for studying biological mechanisms of neurological disorders. However, the heterotypic interactions of neurovascular units, composed of neurons, pericytes (i.e., the tissue resident mesenchymal stromal cells), astrocytes, and brain microvascular endothelial cells, in brain-like tissues are less investigated. In addition, most cortical organoids lack a microglia component, the resident immune cells in the brain. Impairment of the blood-brain barrier caused by improper crosstalk between neural cells and vascular cells is associated with many neurodegenerative disorders. Mesenchymal stem cells (MSCs), with a phenotype overlapping with pericytes, have promotion effects on neurogenesis and angiogenesis, which are mainly attributed to secreted growth factors and extracellular matrices. As the innate macrophages of the central nervous system, microglia regulate neuronal activities and promote neuronal differentiation by secreting neurotrophic factors and pro-/anti-inflammatory molecules. Neuronal-microglia interactions mediated by chemokines signaling can be modulated in vitro for recapitulating microglial activities during neurodegenerative disease progression. In this review, we discussed the cellular interactions and the physiological roles of neural cells with other cell types including endothelial cells and microglia based on iPSC models. The therapeutic roles of MSCs in treating neural degeneration and pathological roles of microglia in neurodegenerative disease progression were also discussed.

scholarly journals Dynamic Interplay between Pericytes and Endothelial Cells during Sprouting Angiogenesis

Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1109 ◽  
Author(s):  
Giulia Chiaverina ◽  
Laura di Blasio ◽  
Valentina Monica ◽  
Massimo Accardo ◽  
Miriam Palmiero ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Ex Vivo ◽  
Cell Types ◽  
Blood Capillary ◽  
Sprouting Angiogenesis ◽  
Mural Cells ◽  
Cellular Recruitment ◽  
Vascular Physiology ◽  
Experimental Approaches ◽  
Dynamic Interplay

Vascular physiology relies on the concerted dynamics of several cell types, including pericytes, endothelial, and vascular smooth muscle cells. The interactions between such cell types are inherently dynamic and are not easily described with static, fixed, experimental approaches. Pericytes are mural cells that support vascular development, remodeling, and homeostasis, and are involved in a number of pathological situations including cancer. The dynamic interplay between pericytes and endothelial cells is at the basis of vascular physiology and few experimental tools exist to properly describe and study it. Here we employ a previously developed ex vivo murine aortic explant to study the formation of new blood capillary-like structures close to physiological situation. We develop several mouse models to culture, identify, characterize, and follow simultaneously single endothelial cells and pericytes during angiogenesis. We employ microscopy and image analysis to dissect the interactions between cell types and the process of cellular recruitment on the newly forming vessel. We find that pericytes are recruited on the developing sprout by proliferation, migrate independently from endothelial cells, and can proliferate on the growing capillary. Our results help elucidating several relevant mechanisms of interactions between endothelial cells and pericytes.

Survival and Metabolic Function of Freshly Isolated Rat Hepatocytes Exposed First to a Heat Shock and Then to an Oxidative Stress

1999 ◽  
Vol 18 (4) ◽  
pp. 239-244
Author(s):  
Isabelle Latour ◽  
Pedro Buc-Calderon
Keyword(s):  
Oxidative Stress ◽  
Heat Shock ◽  
Reduced Glutathione ◽  
Rat Hepatocytes ◽  
Cell Types ◽  
Isolated Rat Hepatocytes ◽  
Tert Butyl Hydroperoxide ◽  
Shock Proteins ◽  
Freshly Isolated Rat Hepatocytes ◽  
Isolated Rat

The formation of heat shock proteins (hsp) leading to thermotolerance has been extensively reported in many cell types. In freshly isolated rat hepatocytes, hsp were synthesized after 60 minutes of incubation at 42°C. Cell survival was not modified by such a treatment, but protein synthesis, secretion of triglycerides as lipoproteins, and the maintenance of both ATP and glycogen levels were significantly impaired. When exposed to an oxidative stress, heat-shocked hepatocytes were not more resistant than cells always kept at 37°C. Conversely, the addition of tert-butyl hydroperoxide (tBOOH) resulted, in general, in an increased lactate dehydrogenase leakage. The metabolism of tBOOH, as estimated by the reduced glutathione (GSH) content and GSH peroxidase activity, was similar in both control and heat-shocked hepatocytes. Despite the synthesis of hsp in rat hepatocytes, the lack of resistance to a subsequent oxidant injury may be due to the metabolic impairment caused by the heat shock.

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