Rat olfactory neurons can utilize the endogenous lectin, L-14, in a novel adhesion mechanism

Development ◽  
1994 ◽  
Vol 120 (6) ◽  
pp. 1373-1384 ◽  
Author(s):  
N.K. Mahanthappa ◽  
D.N. Cooper ◽  
S.H. Barondes ◽  
G.A. Schwarting

L-14 is a divalent, lactosamine-binding lectin expressed in many vertebrate tissues. In the rat nervous system, L-14 expression has been observed previously in restricted neuronal subsets within the dorsal root ganglia and spinal cord. In this study we report that L-14 is expressed by nonneuronal cells in the rat olfactory nerve. We demonstrate that L-14 binds and co-localizes with two ligands in the rat olfactory system: a beta-lactosamine-containing glycolipid, and a putative member of the laminin family. The former is expressed on the surfaces of nascent olfactory axons originating from neuron cell bodies in the olfactory epithelium. The latter is present in the extracellular matrix of the axonal path leading to synaptic targets in the olfactory bulb. In vitro, we find that recombinant L-14 promotes primary olfactory neuron adhesion to two laminin family members, and promotes intercellular adhesion. Both activities are dose-dependent, and are independent of integrin-mediated mechanisms. We have thus found that L-14 can serve two distinct adhesive functions in vitro, and propose that L-14 in vivo can promote olfactory axon fasciculation by crosslinking adjacent axons and promote axonal adhesion to the extracellular matrix.

2021 ◽  
Vol 8 (8) ◽  
pp. 116
Author(s):  
Lumei Liu ◽  
Sayali Dharmadhikari ◽  
Robert A. Pouliot ◽  
Michael M. Li ◽  
Peter M. Minneci ◽  
...  

Synthetic scaffolds for the repair of long-segment tracheal defects are hindered by insufficient biocompatibility and poor graft epithelialization. In this study, we determined if extracellular matrix (ECM) coatings improved the biocompatibility and epithelialization of synthetic tracheal grafts (syn-TG). Porcine and human ECM substrates (pECM and hECM) were created through the decellularization and lyophilization of lung tissue. Four concentrations of pECM and hECM coatings on syn-TG were characterized for their effects on scaffold morphologies and on in vitro cell viability and growth. Uncoated and ECM-coated syn-TG were subsequently evaluated in vivo through the orthotopic implantation of segmental grafts or patches. These studies demonstrated that ECM coatings were not cytotoxic and, enhanced the in vitro cell viability and growth on syn-TG in a dose-dependent manner. Mass spectrometry demonstrated that fibrillin, collagen, laminin, and nephronectin were the predominant ECM components transferred onto scaffolds. The in vivo results exhibited similar robust epithelialization of uncoated and coated syn-TG patches; however, the epithelialization remained poor with either uncoated or coated scaffolds in the segmental replacement models. Overall, these findings demonstrated that ECM coatings improve the seeded cell biocompatibility of synthetic scaffolds in vitro; however, they do not improve graft epithelialization in vivo.


1995 ◽  
Vol 73 (05) ◽  
pp. 805-811 ◽  
Author(s):  
Yasuo Takahashi ◽  
Yoshitaka Hosaka ◽  
Hiromi Niina ◽  
Katsuaki Nagasawa ◽  
Masaaki Naotsuka ◽  
...  

SummaryWe examined the anticoagulant activity of two major molecules of soluble thrombomodulin purified from human urine. The apparent molecular weights of these urinary thrombomodulins (UTMs) were 72,000 and 79,000, respectively. Both UTMs showed more potent cofactor activity for protein C activation [specific activity >5,000 thrombomodulin units (TMU)/mg] than human placental thrombomodulin (2,180 TMU/mg) and rabbit lung thrombomodulin (1,980 TMU/mg). The UTMs prolonged thrombin-induced fibrinogen clotting time (>1 TMU/ml), APTT (>5 TMU/ml), TT (>5 TMU/ml) and PT (>40 TMU/ml) in a dose-dependent fashion. These effects appeared in the concentration range of soluble thrombomodulins present in human plasma and urine. In the rat DIC model induced by thromboplastin, administration of UTMs by infusion (300-3,000 TMU/kg) restored the hematological abnormalities derived from DIC in a dose-dependent fashion. These results demonstrate that UTMs exhibit potent anticoagulant and antithrombotic activities, and could play a physiologically important role in microcirculation.


1997 ◽  
Vol 77 (05) ◽  
pp. 0975-0980 ◽  
Author(s):  
Angel Gálvez ◽  
Goretti Gómez-Ortiz ◽  
Maribel Díaz-Ricart ◽  
Ginés Escolar ◽  
Rogelio González-Sarmiento ◽  
...  

SummaryThe effect of desmopressin (DDAVP) on thrombogenicity, expression of tissue factor and procoagulant activity (PCA) of extracellular matrix (ECM) generated by human umbilical vein endothelial cells cultures (HUVEC), was studied under different experimental conditions. HUVEC were incubated with DDAVP (1, 5 and 30 ng/ml) and then detached from their ECM. The reactivity towards platelets of this ECM was tested in a perfusion system. Coverslips covered with DD A VP-treated ECMs were inserted in a parallel-plate chamber and exposed to normal blood anticoagulated with low molecular weight heparin (Fragmin®, 20 U/ml). Perfusions were run for 5 min at a shear rate of 800 s1. Deposition of platelets on ECMs was significantly increased with respect to control ECMs when DDAVP was used at 5 and 30 ng/ml (p <0.05 and p <0.01 respectively). The increase in platelet deposition was prevented by incubation of ECMs with an antibody against human tissue factor prior to perfusion. Immunofluorescence studies positively detected tissue factor antigen on DDAVP derived ECMs. A chromogenic assay performed under standardized conditions revealed a statistically significant increase in the procoagulant activity of the ECMs produced by ECs incubated with 30 ng/ml DDAVP (p <0.01 vs. control samples). Northern blot analysis revealed increased levels of tissue factor mRNA in extracts from ECs exposed to DDAVP. Our data indicate that DDAVP in vitro enhances platelet adhesion to the ECMs through increased expression of tissue factor. A similar increase in the expression of tissue factor might contribute to the in vivo hemostatic effect of DDAVP.


Author(s):  
Mohammed Ajebli ◽  
Mohamed Eddouks

Aims and objective: The aim of the study was to investigate the effect of aqueous aerial part extract of Mentha pulegium L. (Pennyrile) (MPAE) on arterial pressure parameters in rats. Background: Mentha pulegium is a medicinal plant used to treat hypertension in Morocco. Material and methods: In the current study, MPAE was prepared and its antihypertensive activity was pharmacologically investigated. L-NAME-hypertensive and normotensive rats have received orally MPAE (180 and 300 mg/kg) during six hours for the acute experiment and during seven days for the sub-chronic treatment. Thereafter, systolic, diastolic, mean arterial blood pressure and heart rate were evaluated. While, in the in vitro experiment, isolated denuded and intact thoracic aortic rings were suspended in a tissue bath system and the tension changes were recorded. Results: A fall in blood pressure was observed in L-NAME-induced hypertensive treated with MPAE. The extract also produced a dose-dependent relaxation of aorta pre-contracted with NE and KCl. The study showed that the vasorelaxant ability of MPAE seems to be exerted through the blockage of extracellular Ca2+ entry. Conclusion: The results demonstrate that the extract of pennyrile exhibits antihypertensive activity. In addition, the effect may be, at least in part, due to dilation of blood vessels via blockage of Ca2+ channels.


Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 386
Author(s):  
Ana Santos ◽  
Yongjun Jang ◽  
Inwoo Son ◽  
Jongseong Kim ◽  
Yongdoo Park

Cardiac tissue engineering aims to generate in vivo-like functional tissue for the study of cardiac development, homeostasis, and regeneration. Since the heart is composed of various types of cells and extracellular matrix with a specific microenvironment, the fabrication of cardiac tissue in vitro requires integrating technologies of cardiac cells, biomaterials, fabrication, and computational modeling to model the complexity of heart tissue. Here, we review the recent progress of engineering techniques from simple to complex for fabricating matured cardiac tissue in vitro. Advancements in cardiomyocytes, extracellular matrix, geometry, and computational modeling will be discussed based on a technology perspective and their use for preparation of functional cardiac tissue. Since the heart is a very complex system at multiscale levels, an understanding of each technique and their interactions would be highly beneficial to the development of a fully functional heart in cardiac tissue engineering.


2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Xuxing Shen ◽  
Chao Wu ◽  
Meng Lei ◽  
Qing Yan ◽  
Haoyang Zhang ◽  
...  

AbstractCarfilzomib, a second-generation proteasome inhibitor, has significantly improved the survival rate of multiple myeloma (MM) patients, but its clinical application is still restricted by drug resistance and cardiotoxicity. Here, we identified a novel proteasome inhibitor, D395, and assessed its efficacy in treating MM as well as its cardiotoxicity at the preclinical level. The activities of purified and intracellular proteasomes were measured to determine the effect of D395 on the proteasome. CCK-8 and flow cytometry experiments were designed to evaluate the effects of D395 on cell growth and apoptosis. The effects of D395 and carfilzomib on serum enzyme activity, echocardiography features, cardiomyocyte morphology, and hERG channels were also compared. In our study, D395 was highly cytotoxic to MM cell lines and primary MM cells but not normal cells, and it was well tolerated in vivo. Similar to carfilzomib, D395 inhibited osteoclast differentiation in a dose-dependent manner. In particular, D395 exhibited lower cardiotoxicity than carfilzomib in all experiments. In conclusion, D395 is a novel irreversible proteasome inhibitor that has remarkable anti-MM activity and mild cardiotoxicity in vitro and in vivo.


Biomaterials ◽  
2015 ◽  
Vol 49 ◽  
pp. 37-46 ◽  
Author(s):  
Marc C. Moore ◽  
Vittoria Pandolfi ◽  
Peter S. McFetridge
Keyword(s):  

2021 ◽  
Vol 10 (1) ◽  
pp. 101-111
Author(s):  
Rehman Ullah ◽  
Sumaira Shah ◽  
Zahir Muhammad ◽  
Sajjad Ali Shah ◽  
Shah Faisal ◽  
...  

Abstract The current study was designed to investigate the potential of Euphorbia wallichii shoot extract for reducting Au3+ and stabilizing gold nanoparticles. UV-visible spectra of gold nanoparticles showed obvious surface plasmon resonance peak at 548 nm. Microscopy (SEM and TEM) showed spherical dimensions, and the energy dispersive X-ray spectra displayed the strongest optical absorption peak for gold (Au) at 2.1 keV. Dynamic light scattering spectra represent polydispersed mixture with particulate diameter of 2.5–103.2 nm. The IR spectra confirm the potential functional groups of shoot extract responsible for the reduction of Au3+ to gold nanoparticles which exhibit tremendous antibacterial potential of 76.31%, 68.47%, 79.85%, 48.10%, and 65.53% against Escherichia coli, Staphylococcus aureus, Bacillus pumilus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, respectively. Gold nanoparticles showed markedly elevated fungicidal potency compared to the shoot extract alone against the tested fungal strains. IC50 for 2,2-diphenyl-1-picrylhydrazyl scavenging was 31.52, 18.29, and 15.32 µg/mL at 30, 60, and 90 min of reaction time, respectively. Both shoot extract and nanoparticles revealed 71% mortality at 100 µg/mL, with LD90 values of 310.56 µg/mL. Experimental mice acquired dose-dependent analgesia of 54.21%, 82.60%, and 86.53% when treated with gold nanoparticles at 50, 100, and 200 mg/kg bw. Inhibition of gastrointestinal muscular contraction was 21.16%, 30.49%, and 40.19% in mice feed with 50, 100, and 200 mg/kg bw, respectively.


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