scholarly journals Spaceflight on the Bion-M1 biosatellite alters cerebral artery vasomotor and mechanical properties in mice

2015 ◽  
Vol 118 (7) ◽  
pp. 830-838 ◽  
Author(s):  
Svetlana I. Sofronova ◽  
Olga S. Tarasova ◽  
Dina Gaynullina ◽  
Anna A. Borzykh ◽  
Bradley J. Behnke ◽  
...  
Keyword(s):  
Blood Flow ◽  
Matrix Protein ◽  
Cerebral Arteries ◽  
Rho Kinase ◽  
Extracellular Matrix Protein ◽  
Vascular Control ◽  
Cross Sectional ◽  
Basilar Arteries ◽  
Medial Wall Thickness

Conditions during spaceflight, such as the loss of the head-to-foot gravity vector, are thought to potentially alter cerebral blood flow and vascular resistance. The purpose of the present study was to determine the effects of long-term spaceflight on the functional, mechanical, and structural properties of cerebral arteries. Male C57BL/6N mice were flown 30 days in a Bion-M1 biosatellite. Basilar arteries isolated from spaceflight (SF) ( n = 6), habitat control (HC) ( n = 6), and vivarium control (VC) ( n = 16) mice were used for in vitro functional and mechanical testing and histological structural analysis. The results demonstrate that vasoconstriction elicited through a voltage-gated Ca2+ mechanism (30–80 mM KCl) and thromboxane A2 receptors (10−8 − 3 × 10−5 M U46619) are lower in cerebral arteries from SF mice. Inhibition of Rho-kinase activity (1 μM Y27632) abolished group differences in U46619-evoked contractions. Endothelium-dependent vasodilation elicited by acetylcholine (10 μM, 2 μM U46619 preconstriction) was virtually absent in cerebral arteries from SF mice. The pressure-diameter relation was lower in arteries from SF mice relative to that in HC mice, which was not related to differences in the extracellular matrix protein elastin or collagen content or the elastin/collagen ratio in the basilar arteries. Diameter, medial wall thickness, and medial cross-sectional area of unpressurized basilar arteries were not different among groups. These results suggest that the microgravity-induced attenuation of both vasoconstrictor and vasodilator properties may limit the range of vascular control of cerebral perfusion or impair the distribution of brain blood flow during periods of stress.

scholarly journals in vitro Effects of Calcium Antagonists PN 200-110, Nifedipine, and Nimodipine on Human and Canine Cerebral Arteries

1983 ◽  
Vol 3 (3) ◽  
pp. 354-361 ◽  
Author(s):  
E. Müller-Schweinitzer ◽  
P. Neumann
Keyword(s):  
Rank Order ◽  
Cerebral Arteries ◽  
Isometric Tension ◽  
Mesenteric Arteries ◽  
Organ Bath ◽  
Vasoconstrictor Response ◽  
Dihydropyridine Derivative ◽  
Basilar Arteries ◽  
In Vitro Effects

PN 200–110 [4-(2, 1, 3-benzoxadiazol - 4 -) - 1,4-dihydro - 2,6 - dimethyl - pyridine - 3,5 - dicarboxylic acid methyl 1-methylethyl ester], a new dihydropyridine derivative, was investigated by recording isometric tension on spiral strips from human and canine arteries in tissue baths at 37°C. Responses to increasing concentrations of CaCl2 were investigated in calcium-free depolarizing solution (60 mmol/L KCl in equimolar replacement for NaCl, 50 mmol/L TRIZMA buffer, pH 7.4). Comparison of those concentrations that reduced the vasoconstrictor response to 1.6 mmol/L CaCl2 by 50% revealed the following order of potencies on both human and canine arteries: PN 200–110 > nimodipine > nifedipine. Responses to 5-hydroxytryptamine (5-HT) and blood were investigated in Krebs–Henseleit solution (NaHCO3 buffer). On canine arteries, PN 200–110 antagonized responses to 5-HT when used at 10–30 pmol/L; it was ∼70 times more potent on basilar than on mesenteric arteries, whereas both nifedipine and nimodipine were, respectively, ∼10 and 6 times more potent on basilar than on mesenteric arteries. When canine basilar arteries were constricted by the addition of blood to the organ bath, each of the investigated dihydropyridine derivatives elicited concentration-dependent relaxation, producing the following order of potencies: PN 200–110 > nifedipine = nimodipine. On human anterior cerebral arteries, the blood-induced contractions were counteracted in the following rank order: PN 200–110 = nimodipine > nifedipine. The results suggest that due to its potent calcium-blocking activity on cerebral arteries, PN 200–110 might be of value for the prevention and treatment of cerebrovascular spasms following subarachnoid hemorrhage.

scholarly journals Low-Intensity Pulsed Ultrasound Promotes Autophagy-Mediated Migration of Mesenchymal Stem Cells and Cartilage Repair

2021 ◽  
Vol 30 ◽  
pp. 096368972098614
Author(s):  
Peng Xia ◽  
Xinwei Wang ◽  
Qi Wang ◽  
Xiaoju Wang ◽  
Qiang Lin ◽  
...  
Keyword(s):  
Cartilage Repair ◽  
Matrix Protein ◽  
Extracellular Matrix Protein ◽  
Histopathological Analysis ◽  
Pulsed Ultrasound ◽  
Low Intensity Pulsed Ultrasound ◽  
Low Intensity ◽  
Autophagy Inhibitor

Mesenchymal stem cell (MSC) migration is promoted by low-intensity pulsed ultrasound (LIPUS), but its mechanism is unclear. Since autophagy is known to regulate cell migration, our study aimed to investigate if LIPUS promotes the migration of MSCs via autophagy regulation. We also aimed to investigate the effects of intra-articular injection of MSCs following LIPUS stimulation on osteoarthritis (OA) cartilage. For the in vitro study, rat bone marrow-derived MSCs were treated with an autophagy inhibitor or agonist, and then they were stimulated by LIPUS. Migration of MSCs was detected by transwell migration assays, and stromal cell-derived factor-1 (SDF-1) and C-X-C chemokine receptor type 4 (CXCR4) protein levels were quantified. For the in vivo study, a rat knee OA model was generated and treated with LIPUS after an intra-articular injection of MSCs with autophagy inhibitor added. The cartilage repair was assessed by histopathological analysis and extracellular matrix protein expression. The in vitro results suggest that LIPUS increased the expression of SDF-1 and CXCR4, and it promoted MSC migration. These effects were inhibited and enhanced by autophagy inhibitor and agonist, respectively. The in vivo results demonstrate that LIPUS significantly enhanced the cartilage repair effects of MSCs on OA, but these effects were blocked by autophagy inhibitor. Our results suggest that the migration of MSCs was enhanced by LIPUS through the activation autophagy, and LIPUS improved the protective effect of MSCs on OA cartilage via autophagy regulation.

Contrasting migratory response of astrocytoma cells to tenascin mediated by different integrins

1996 ◽  
Vol 109 (8) ◽  
pp. 2161-2168 ◽  
Author(s):  
A. Giese ◽  
M.A. Loo ◽  
S.A. Norman ◽  
S. Treasurywala ◽  
M.E. Berens
Keyword(s):  
Cell Adhesion ◽  
Matrix Protein ◽  
Glioma Cells ◽  
Extracellular Matrix Protein ◽  
Integrin Receptors ◽  
Migration Assay ◽  
Dose Dependent Fashion ◽  
Beta 1 Integrin

Tenascin, an extracellular matrix protein, is expressed in human gliomas in vitro and in vivo. The distribution of tenascin at the invasive edge of these tumors, even surrounding solitary invading cells, suggests a role for this protein as a regulator of glioma cell migration. We tested whether purified tenascin, passively deposited on surfaces, influenced the adhesion or migration of a human gliomaderived cell line, SF-767. Adhesion of glioma cells to tenascin increased in a dose-dependent fashion up to a coating concentration of 10 micrograms/ml. Higher coating concentrations resulted in progressively fewer cells attaching. Cell adhesion could be blocked to basal levels using anti-beta 1 integrin antibodies. In contrast, when anti-alpha v antibodies were added to the medium of cells on tenascin, cell adhesion was enhanced slightly. Using a microliter scale migration assay, we found that cell motility on tenascin was dose dependently stimulated at coating concentrations of 1 and 3 micrograms/ml, but migration was inhibited below levels of non-specific motility when tested at coating concentrations of 30 and 100 micrograms/ml. Migration on permissive concentrations of tenascin could be reversibly inhibited with anti-beta 1, while treatment with anti-alpha v antibodies increased migration rates. We conclude that SF-767 glioma cells express two separate integrin receptors that mediate contrasting adhesive and migratory responses to tenascin.

scholarly journals Amylin: Localization, Effects on Cerebral Arteries and on Local Cerebral Blood Flow in the Cat

2001 ◽  
Vol 1 ◽  
pp. 168-180 ◽  
Author(s):  
Lars Edvinsson ◽  
Peter J. Goadsby ◽  
Rolf Uddman
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Blood Vessels ◽  
Cerebral Arteries ◽  
In Vivo Studies ◽  
Cerebral Blood Vessels ◽  
Local Cerebral Blood Flow ◽  
Doppler Flowmetry

Amylin and adrenomedullin are two peptides structurally related to calcitonin gene-related peptide (CGRP). We studied the occurrence of amylin in trigeminal ganglia and cerebral blood vessels of the cat with immunocytochemistry and evaluated the role of amylin and adrenomedullin in the cerebral circulation by in vitro and in vivo pharmacology. Immunocytochemistry revealed that numerous nerve cell bodies in the trigeminal ganglion contained CGRP immunoreactivity (-ir); some of these also expressed amylin-ir but none adrenomedullin-ir. There were numerous nerve fibres surrounding cerebral blood vessels that contained CGRP-ir. Occasional fibres contained amylin-ir while we observed no adrenomedullin-ir in the vessel walls. With RT-PCR and Real-Time�PCR we revealed the presence of mRNA for calcitonin receptor-like receptor (CLRL) and receptor-activity-modifying proteins (RAMPs) in cat cerebral arteries. In vitro studies revealed that amylin, adrenomedullin, and CGRP relaxed ring segments of the cat middle cerebral artery. CGRP and amylin caused concentration-dependent relaxations at low concentrations of PGF2a-precontracted segment (with or without endothelium) whereas only at high concentration did adrenomedullin cause relaxation. CGRP8-37 blocked the CGRP and amylin induced relaxations in a parallel fashion. In vivo studies of amylin, adrenomedullin, and CGRP showed a brisk reproducible increase in local cerebral blood flow as examined using laser Doppler flowmetry applied to the cerebral cortex of the a-chloralose�anesthetized cat. The responses to amylin and CGRP were blocked by CGRP8-37. The studies suggest that there is a functional sub-set of amylin-containing trigeminal neurons which probably act via CGRP receptors.

scholarly journals LTBP1 promotes fibrillin incorporation into the extracellular matrix

2021 ◽  
Author(s):  
Matthias Przyklenk ◽  
Veronika Georgieva ◽  
Fabian Metzen ◽  
Sebastian Mostert ◽  
Birgit Kobbe ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Matrix Protein ◽  
Wide Spectrum ◽  
Extracellular Matrix Protein ◽  
Connective Tissues ◽  
Pathogenic Variants ◽  
Human Pathology ◽  
Fibrillin 1

LTBP1 is a large extracellular matrix protein and an associated ligand of fibrillin-microfibrils. Knowledge of LTBP1 functions is largely limited to its role in targeting and sequestering TGFβ growth factors within the extracellular matrix, thereby regulating their bioavailability. However, the recent description of a wide spectrum of phenotypes in multiple tissues in patients harboring LTBP1 pathogenic variants suggests a multifaceted role of the protein in the homeostasis of connective tissues. To better understand the human pathology caused by LTBP1 deficiency it is important to investigate its functional role in extracellular matrix formation. In this study, we show that LTBP1 coordinates the incorporation of fibrillin-1 and -2 into the extracellular matrix in vitro. We also demonstrate that this function is differentially exerted by the two isoforms, the short and long forms of LTBP1. Thereby our findings uncover a novel TGFβ-independent LTBP1 function potentially contributing to the development of connective tissue disorders.

scholarly journals Xenopus embryonic cell adhesion to fibronectin: position-specific activation of RGD/synergy site-dependent migratory behavior at gastrulation.

1996 ◽  
Vol 134 (1) ◽  
pp. 227-240 ◽  
Author(s):  
J W Ramos ◽  
D W DeSimone
Keyword(s):  
Cell Adhesion ◽  
Matrix Protein ◽  
Marginal Zone ◽  
Cell Attachment ◽  
Extracellular Matrix Protein ◽  
Mesoderm Induction ◽  
Type Iii ◽  
Basic Body ◽  
And Migration

During Xenopus laevis gastrulation, the basic body plan of the embryo is generated by movement of the marginal zone cells of the blastula into the blastocoel cavity. This morphogenetic process involves cell adhesion to the extracellular matrix protein fibronectin (FN). Regions of FN required for the attachment and migration of involuting marginal zone (IMZ) cells were analyzed in vitro using FN fusion protein substrates. IMZ cell attachment to FN is mediated by the Arg-Gly-Asp (RGD) sequence located in the type III-10 repeat and by the Pro-Pro-Arg-Arg-Ala-Arg (PPRRAR) sequence in the type III-13 repeat of the Hep II domain. IMZ cells spread and migrate persistently on fusion proteins containing both the RGD and synergy site sequence Pro-Pro-Ser-Arg-Asn (PPSRN) located in the type III-9 repeat. Cell recognition of the synergy site is positionally regulated in the early embryo. During gastrulation, IMZ cells will spread and migrate on FN whereas presumptive pre-involuting mesoderm, vegetal pole endoderm, and animal cap ectoderm will not. However, animal cap ectoderm cells acquire the ability to spread and migrate on the RGD/synergy region when treated with the mesoderm inducing factor activin-A. These data suggest that mesoderm induction activates the position-specific recognition of the synergy site of FN in vivo. Moreover, we demonstrate the functional importance of this site using a monoclonal antibody that blocks synergy region-dependent cell spreading and migration on FN. Normal IMZ movement is perturbed when this antibody is injected into the blastocoel cavity indicating that IMZ cell interaction with the synergy region is required for normal gastrulation.

Asporin competes with decorin for collagen binding, binds calcium and promotes osteoblast collagen mineralization

2009 ◽  
Vol 423 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Sebastian Kalamajski ◽  
Anders Aspberg ◽  
Karin Lindblom ◽  
Dick Heinegård ◽  
Åke Oldberg
Keyword(s):  
Matrix Protein ◽  
Collagen Type I ◽  
Full Length ◽  
Extracellular Matrix Protein ◽  
Type I ◽  
Similar System ◽  
Collagen Binding ◽  
Osteoblastic Activity ◽  
Collagen Mineralization

The interactions of the ECM (extracellular matrix) protein asporin with ECM components have previously not been investigated. Here, we show that asporin binds collagen type I. This binding is inhibited by recombinant asporin fragment LRR (leucine-rich repeat) 10–12 and by full-length decorin, but not by biglycan. We demonstrate that the polyaspartate domain binds calcium and regulates hydroxyapatite formation in vitro. In the presence of asporin, the number of collagen nodules, and mRNA of osteoblastic markers Osterix and Runx2, were increased. Moreover, decorin or the collagen-binding asporin fragment LRR 10–12 inhibited the pro-osteoblastic activity of full-length asporin. Our results suggest that asporin and decorin compete for binding to collagen and that the polyaspartate in asporin directly regulates collagen mineralization. Therefore asporin has a role in osteoblast-driven collagen biomineralization activity. We also show that asporin can be expressed in Escherichia coli (Rosetta-gami™) with correctly positioned cysteine bridges, and a similar system can possibly be used for the expression of other SLRPs (small LRR proteoglycans/proteins).

Hypoxia – as a Possible Regulator of the Activity of Epicardial Mesothelial Cells After Myocardial Infarction

Kardiologiia ◽  
2021 ◽  
Vol 61 (6) ◽  
pp. 59-68
Author(s):  
K. V. Dergilev ◽  
Z. I. Tsokolaeva ◽  
Yu. D. Vasilets ◽  
I. B. Beloglazova ◽  
B. N. Kulbitsky ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Extracellular Matrix ◽  
Matrix Protein ◽  
Mesothelial Cells ◽  
Immunofluorescent Staining ◽  
Extracellular Matrix Protein ◽  
Hypoxic Exposure ◽  
Mesenchymal Transition ◽  
Epicardial Cells

Aim      To study the effect of hypoxia on the activity of epithelial-mesenchymal transition (EMT) in epicardial cells, which provides formation of a specialized microenvironment.Material and methods   This study used a model of experimental myocardial infarction created by ligation of the anterior descendent coronary artery. The activity of epicardial cells after a hypoxic exposure was studied with the hypoxia marker, pimonidazole, bromodeoxyuridine, immunofluorescent staining of heart cryosections, and in vitro mesothelial cell culture.Results The undamaged heart maintained the quiescent condition of mesothelial cells and low levels of their proliferation, extracellular matrix protein production, and of the EMT activity. Acute ischemic injury induced moderate hypoxia in the epicardial/subepicardial region. This caused a global rearrangement of this region due to the initiation of EMT in cells, changes in the cell composition, and accumulation of extracellular matrix proteins. We found that the initiation of EMT in mesothelial cells may result in the formation of smooth muscle cell precursors, fibroblasts, and a population of Sca-1+ cardiac progenitor cells, which may both participate in construction of new blood vessels and serve as a mesenchymal link for the paracrine support of microenvironmental cells. In in vitro experiments, we showed that 72‑h hypoxia facilitated activation of EMT regulatory genes, induced dissembling of intercellular contacts, cell uncoupling, and increased cell plasticity.Conclusion      The epicardium of an adult heart serves as a “reparative reserve” that can be reactivated by a hypoxic exposure. This creates a basis for an approach to influence the epicardium to modulate its activity for regulating reparative processes.

Abstract TMP118: Potential Therapeutic Benefits of Perlecan Domain V in Preclinical Vascular Dementia and Cerebral Angiopathy

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Amanda L Trout ◽  
Zuohui Zhang ◽  
Jill Roberts ◽  
Gillian Grohs ◽  
Ela Patel ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Parietal Cortex ◽  
Matrix Protein ◽  
Extracellular Matrix Protein ◽  
Amyloid Angiopathy ◽  
Cognitive Changes ◽  
Cerebral Microvessels ◽  
Therapeutic Benefits ◽  
Domain V

Vascular contributions to cognitive impairment and dementia (VCID), the second leading cause of dementia behind Alzheimer’s disease (AD), is a broad term that encompasses a spectrum of initial asymptomatic cerebrovascular changes (seen in small vessel disease and cerebral amyloid angiopathy where pathologic Aβ1-42 protein accumulates around brain blood vessels) to the profound symptomatic damage following acute stroke(s). Cerebrovascular remodeling and new blood vessel growth (angiogenesis) may represent early compensatory changes to reduced cerebral blood flow that can initiate VCID. Angiogenesis, in turn, is supported by various growth factors and the proteolytic turnover of surrounding extracellular matrix. We have demonstrated that one such extracellular matrix protein, perlecan (a heparan sulfate proteoglycan), possesses a C terminal domain V (DV) protein that upon cleavage greatly enhances brain angiogenesis. We characterized VCID induced changes in DV expression in the human parietal cortex and a distinct mouse model (diabetic APP/PS1 knock in (db/AD)), that has a gradual cognitive decline by 9 months with microangiopathy, Aβ1-42 deposition, aneurysms, and microhemorrhages. We also utilized an in vitro model of the blood-brain barrier (BBB) to assess the transport of human Aβ1-42 in the presence of DV. In the human parietal cortex, dementia patients had increased expression of DV despite having fewer cells. In db/AD animals (3-6 months), we observed a decrease in BBB proteins (i.e. claudin-5), indicating that altered function correlated with an increase in brain DV expression during the asymptomatic angiogenic stage, which precedes cognitive changes (9-12 months). In vitro, DV doubled the transport of Aβ1-42 into the lumen of cerebral microvessels over 24 hours with increased activity and total protein expression of P-glycoprotein (P-gp), one of Aβ’s known transport proteins. Collectively, these data indicate that early cerebrovascular changes induce angiogenic-remodeling that correlates with increased expression of DV. DV, in turn, may further enhance angiogenesis and increase brain Aβ clearance into the vascular compartment through P-gp, suggesting that DV could represent a novel therapeutic for VCID.

Role of mesenchymal nidogen for epithelial morphogenesis in vitro

Development ◽  
1994 ◽  
Vol 120 (7) ◽  
pp. 2003-2014 ◽  
Author(s):  
P. Ekblom ◽  
M. Ekblom ◽  
L. Fecker ◽  
G. Klein ◽  
H.Y. Zhang ◽  
...  
Keyword(s):  
Matrix Protein ◽  
Northern Blotting ◽  
Epithelial Morphogenesis ◽  
Extracellular Matrix Protein ◽  
Epithelial Development ◽  
Morphogenesis In Vitro ◽  
Development In Vitro ◽  
Membrane Components

Recent biochemical studies suggested that the extracellular matrix protein nidogen is a binding molecule linking together basement membrane components. We studied its expression and role during development. By immunofluorescence and northern blotting, nidogen was found early during epithelial cell development of kidney and lung. Yet, in situ hybridization revealed that nidogen was not produced by epithelium but by the adjacent mesenchyme in both organs. Binding of mesenchymal nidogen to epithelial laminin may thus be a key event during epithelial development. This is supported by antibody perturbation experiments. Antibodies against the nidogen binding site on laminin B2 chain perturbed epithelial development in vitro in embryonic kidney and lung. Mesenchymal nidogen could be important for early stages of epithelial morphogenesis.

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