57 research outputs found
Methods of mesenchymal stem cell homing to the blood-brain barrier
Mesenchymal stem/stromal cells (MSC) are multipotent cells that can be isolated from adult and fetal tissues. In vitro, MSCs show functional plasticity by differentiating into specialized cells of all germ layers. MSCs are of relevant to medicine and have been proposed for several disorders. MSCs can be transplanted across allogeneic barriers as "off the shelf" cells. This chapter focuses on methods to deliver MSCs to the brain because neurological pathology such as damage due to stroke can lead to debilitating mental and physical problems. In general, neurological diseases are difficult to treat, partly due to the challenge in getting drugs across the blood-brain barrier (BBB). MSCs as well as other stem cells can cross the BBB. The described method begins to develop procedures, leading to efficient delivery of drugs to the brain. Here describe how MSCs can be propagated from bone marrow aspirates and their utility in delivering small RNA to the brain. The chapter discusses the issue to enhance efficient delivery of MSCs to the brain
Novel Conducting and Biodegradable Copolymers with Noncytotoxic Properties toward Embryonic Stem Cells
Electroactive biomaterials
that are easily processed as scaffolds
with good biocompatibility for tissue regeneration are difficult to
design. Herein, the synthesis and characterization of a variety of
novel electroactive, biodegradable biomaterials based on poly(3,4-ethylenedioxythiphene)
copolymerized with poly(d,l lactic acid) (PEDOT-<i>co</i>-PDLLA) are presented. These copolymers were obtained
using (2,3-dihydrothieno[3,4-<i>b</i>][1,4]dioxin-2-yl)methanol
(EDOT-OH) as an initiator in a lactide ring-opening polymerization
reaction, resulting in EDOT–PDLLA macromonomer. Conducting
PEDOT-<i>co</i>-PDLLA copolymers (in three different proportions)
were achieved by chemical copolymerization with 3,4-ethylenedioxythiophene
(EDOT) monomers and persulfate oxidant. The PEDOT-<i>co</i>-PDLLA copolymers were structurally characterized by <sup>1</sup>H NMR and Fourier transform infrared spectroscopy. Cyclic voltammetry
confirmed the electroactive character of the materials, and conductivity
measurements were performed via electrochemical impedance spectroscopy.
In vitro biodegradability was evaluated using <i>proteinase K</i> over 35 days, showing 29–46% (w/w) biodegradation. Noncytotoxicity
was assessed by adhesion, migration, and proliferation assays using
embryonic stem cells (E14.tg2a); excellent neuronal differentiation
was observed. These novel electroactive and biodegradable PEDOT-<i>co</i>-PDLLA copolymers present surface chemistry and charge
density properties that make them potentially useful as scaffold materials
in different fields of applications, especially for neuronal tissue
engineering
Boletín de Segovia: Número 1 - 1837 enero 3
Copia digital. Madrid : Ministerio de Cultura. Subdirección General de Coordinación Bibliotecaria, 200
Additional file 2: Figure S1. of Extracellular nucleotides as novel, underappreciated pro-metastatic factors that stimulate purinergic signaling in human lung cancer cells
Evaluation of the number of BM cells and the level of EXN in plasma after irradiation or chemotheraphy. Panel A Total number of cells isolated from tibia and femurs of animals 24 h after irradiation (0–1500 cGy) or vincristine administration (0.5–2 mg/kg). Combine results from three independent isolations. Panel B The level of ATP, UTP and adenosine in murine plasma isolated from animals 24 h after irradiation (0–1500 cGy) or vincristine administration (0.5–2 mg/kg). (PDF 229 kb
Kinin-B2 receptor mediated protection against NMDA-induced excitotoxicity and its reversion by Lys-des-Arg<sup>9</sup>-bradykinin.
<p>Peak areas of synaptically elicited population spikes (PSs) recorded in the <i>stratum pyramidale</i> region of hippocampal slices are reported as mean values ± S.E.M. Bradykinin (BK) (10 nM and 1 µM) protected against NMDA (0.5 mM)-mediated cytotoxicity (n = 21, *** p<0.001, compared to control values in the presence of NMDA alone). Neuroprotection induced by 10 nM BK was abolished in the presence of 100 nM HOE-140 (HOE) (n = 21, ### p<0.001, values obtained in the presence of NMDA and BK compared to those collected in the presence of NMDA, BK and HOE-140). The MEK/MAPK inhibitor PD98059 (50 µM) did not interfere with BK-mediated neuroprotection. The PI3-kinase inhibitor LY294002 (10 µM) co-applied with 10 nM BK blocked neuroprotection conferred by BK (n = 21, p<0.05, compared to control values in the presence of BK alone). BK (10 nM)-exerted effects were abolished by 100 nM of the B1BKR agonist Lys-des-Arg<sup>9</sup>-BK (p<0.001, compared to control values in the presence of BK alone). Lys-des-Arg<sup>9</sup>-BK-mediated blockade of neuroprotection was reverted in the presence of PD98059 (50 µM) or the B1BKR antagonist Lys-des-Arg<sup>9</sup>-Leu<sup>8</sup>-bradykinin (1 µM) (p<0.001, compared to control values in the presence of BK and Lys-des-Arg<sup>9</sup>-BK) (n = 21). Statistical analysis was done by one way ANOVA followed by the Dunn's method.</p
IQ and selected analogues reverse Aβ40 inhibition of nAChRs in PC12 cells.
<p>(A) Current responses (normalized by the maximal current evoked by 0.2 mM CCh) of neuronal-differentiated PC12 cells exposed for 2 s to 0.2 mM CCh plus 200 nM Aβ40 in all experimental conditions, except for the control measurement with CCh alone, and, as indicated, 500 nM of different IQ analogues. Bars represent means ± S.D. of at least 3 replicate measurements performed in 4–6 different cells (**, p<0.01; *** p<0.001 in the comparison with the control current evoked by CCh alone).</p
Verification of population spike recovery in the presence of kinin-B1 receptor agonists and antagonists.
<p>Synaptically elicited PSs were recorded in the stratum pyramidale region in the absence of NMDA. Control slices were treated only with ACSF and compared with slices treated with 100 nM or 1 µM concentrations of the B1BKR receptor antagonist Lys-des-Arg<sup>9</sup>-Leu<sup>8</sup>-BK or agonist Lys-des-Arg<sup>9</sup>-BK. PSs were measured before and after the application of peptides. Data are presented as mean values ± S.D. (n = 28).</p
Relation of population spike recovery with apoptosis rates.
<p>Initial population spikes (PS) were recorded in <i>stratum pyramidale</i> region of hippocampal slices prior to and following a 10 min application of 0.5 mM NMDA. A) Z-LEHD-FMK, a cell-permeant caspase 9 inhibitor (C.I.), was superfused during 1 h prior to NMDA administration or during 1 h after NMDA. Each lane was superfused for 1 h with ACSF, and the initial PS was recorded from seven slices per lane. For the NMDA lane, the perfusion with ACSF continued for 1 h. Then 0.5 mM NMDA was applied for 10 min; the second lane was superfused with 5 µM of the caspase 9 inhibitor for 1 h after NMDA washout; the third lane was superfused with the inhibitor for 1 h prior to exposure to 0.5 mM NMDA for 10 min. After that, all three lanes were superfused with ACSF for 1 h, and at the end of this time, the final PS was recorded. PS recovery rates (peak areas) obtained in the NMDA alone were compared with those obtained in the presence of 0.5 mM NMDA plus 5 µM Z-LEDH-FMK (C.I.) (n = 21, ***, <i>p</i><0.001, as analyzed by Student's t-test). B) The same protocol describe above was used for GSK-3 inhibition (GSK I) by 25 µM SB-216763 (n = 21, * <i>p</i><0.05). C) NMDA-triggered excitotoxicity induces cytochrome c release from mitochondria and is correlated with the decrease of PS areas. Cytochrome c release was measured after 3 hours. The amount of cytochrome c released after NMDA was more than 2 fold greater (220±20%) than detected in control fraction obtained from slices superfused with ACSF (n = 3, p<0.05). (A) to (C): Data are presented as mean values ± standard deviation (S.D.).</p
Suggested conserved amino acid sequence for reversal of α3β4 nAChR inhibition by Aβ.
<p>Suggested conserved amino acid sequence for reversal of α3β4 nAChR inhibition by Aβ.</p
Effects of IQ and analogues on Aβ40 inhibition of α3β4 nAChRs in transformed HEK cells.
<p>(A) HEK cells expressing recombinant α3β4 nAChRs received 3 consecutive shots (at 4 min intervals) of 0.2 mM CCh plus 200 nM Aβ40 in the absence or presence of 0.5 and 2 µM IQTTWSR. QI and SQI (500 nM) were used as ineffective control peptides. Recovery of current response was evaluated after washout and 3 shots of CCh alone. (B) HEK cells expressing recombinant α3β4 nAChRs received 3 consecutive shots of 0.2 mM CCh plus 200 nM Aβ40 in the absence or presence of 500 nM TTWS, TWSR or IQTTASR. QI and SQI (500 nM) were used as ineffective control peptides. Recovery of current response was evaluated after washout and 3 shots of CCh alone. Bars represent mean values ± S.D. of current responses (normalized by the maximal current evoked by 0.2 mM CCh) of at least 3 measurements performed in at least 3 different cells. (***, p<0.001).</p
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