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Objective To explore the embolization effect of new platinum coils coated with [4COOH-P (DLLA-co-TMC)] biodegradable polymer and released vascular endothelial growth factor (VEGF) into intracranial aneurysms on rat intracranial aneurysms. Methods A total of 54 adult healthy female SD rats were randomly divided into Group Ⅰ with general platinum coils, Group Ⅱ with polymer-coated platinum coils and Group Ⅲ with platinum coils modified with VEGF (n=18).The right common carotid arteries (CCA) of rats in each group were exposed; and the 8 mm lengths of platinum coil segments were inserted into the ligated right CCA of rats. The distal right CCA was performed ligation and restored the blood flow; 6 rats each time at 15,30 and 90 d after the surgery were chosen;and the distal right CCA was used as aneurysm models,and the left CCA without the coil placement or surgical disruption in Group I with general platinum coil was chosen as normal control.The proliferation and fibrosis of endothelial cells were observed by HE staining; von Willebrand Factor (vWF) expression was detected by immunohistochemical staining; and VEGF expression was examined by Western blotting. Results Cellular proliferation and fibrosis in Group Ⅲ with platinum coils modified with VEGF enjoyed significantly higher grade than those in Group Ⅰ with general platinum coils 10,60 and 90d after the surgery (P＜0.05); Cellular proliferation and fibrosis in Group Ⅲ with platinum coils modified with VEGF enjoyed significantly higher grades than those in Group Ⅱ with polymer-coated platinum coils 30 d after the surgery (P＜0.05).Pathological observations showed that the massive intimal hyperplasia and substantial clot completely occluded the aneurysm lumen in Group Ⅲ with platinum coils modified with VEGF; New small blood vessels having vwf-positive expression were noted in the fiberized tissues;the thrombosis in Group Ⅰ with general platinum coils and Group Ⅱ with polymer-coat platinum coils were not fully organized and showed loose hyperplasia structure with a large number of internal spaces.Western blotting indicated that the VEGF level in Group Ⅲ with platinum coils modified with VEGF were significantly higher than that in other groups 15 and 30 d after the operation,however,the VEGF level in Group Ⅲ with platinum coils modified with VEGF 90 d after the surgery was decreased because the lumen completed fibration and degradation of 4COOH-P (DLLA-co-TMC). Conclusion The VEGF-eontaining biodegradable polymer,by slowly releasing VEGF to modify the surface of platinum coils, could enhance the cellular proliferation, thrombosis and formation of dense fibrous tissue in aneurysm lumen; as compared with general platinum coils,these new platinum coils could occlude the rat aneurysm faster and more completely.
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[Objective]To explore the distribution and expression changes of tight junctional protein JAM-1 in rat models after intracerebral hemorrhage (ICH) and their significance.[Methods]One hundred and twenty-eighty healthy male SD rats were randomly divided into normal control group (n=16) and ICH group (n=112),and the ICH models were induced by stereotactically injecting 75 uL autologous blood into the right caudate nucleus.Seven time points after ICH (6,12,24 and 48 h,and 3,7 and 14 d after ICH,16 rats for each time point) were chosen.BBB permeability was evaluated by Evans blue dye extravasation.The distribution and expression of JAM-1 were detected by immunofluorescence and real-time quantitative PCR.[Results] As compared with that in the normal control group,BBB permeability in the ICH group significantly increased at 24 and 48 h,and 3 and 7 d after ICH (P＜0.05).JAM-1 expression decreased at blood vessels at 12,24 and 48 h after ICH,and JAM-1 expressed at the circulatingleukocytes3 dafterlCH,and abundant JAM-1 positive cells around hematoma were noted in the ED-l-positve macrophages 7 d after ICH.JAM-I mRNA significantly decreased at 12,24 and 48 h after ICH,and significantly increased 7 d after ICH as compared with that in the normal control group (P＜0.05).[Conclusion] JAM-1 experssion changes not only participate in regulation of BBB permeability but also play roles in inflammatory insult after ICH.
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Objective To investigate the proliferative differences of adipose-derived stem cells (ADSCs) from neonatal suckling SD rats (5-d-old) and adult ones under the same culture condition.Methods ADSCs were isolated from the subcutaneous adipose tissues of neonatal suckling SD rats and adult ones,and then,type Ⅰ collagenase digestion was employed to obtain the ADSCs; the morphology of these cells was detected.The expressions of such cell surface markers as CD45,CD29 and CD90 were observed. The number of ADSCs on the 4th d of culture under the same condition and with the same planted density was compared between the neonate and adult rats. In vitro culture of the second generation of ADSCs was performed in the 96-well plates, and CCK-8 and alamar blue kit were employed to compare and quantitate the proliferative differences; optical density was observed by microplate reader. Results The ADSCs from neonatal SD rats and adult ones expressed the stem cell biomarkers: the expression of CD45 was negative, and that of CD29 was 98.04％ and 93.17％,respectively,and that of CD90 was 94.92％ and 93.3％,respectively,for neonate SD rat and adult ones.The cell counting results indicated that the number of ADSCs from neonatal rats ([8.87±0.13]×105 cells) was larger than that of adult ones ([4.51±0.36]×105 cells) after being cultured under the same condition and at the same planted density. The optical density value of ADSCs in neonatal rats was significantly higher than that in adult ones on the 6th and 7th d of culturing detected by CCK-8 kit and on the 2nd-7th d of culturing by alamar blue assay. Conclusion The proliferative ability of ADSCs from neonatal rats is greater than that of adult ones.
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Objective To investigate the effect of nimesulide (NIM), a selective cyclooxygenase-2 (COX-2) inhibitor, on angiopoietins (Ang) gene expression of human glioma xenografts in nude mice and its significance. Methods Human SHG44 glioma cells were inoculated subcutaneously in 16 nude mice to establish xenograft models, and then these mouse models were randomly divided into NIM treatment group and control group. NIM (6 mg/kg) and saline were poured into the stomachs of the mice in each group, respectively, once daily for 35 d. The mRNA expressions of Ang-1 gene and Ang-2 gene in the xenografts were determined by RT-PCR. Microvessel density (MVD) in the xenografts was assessed by immunohistochemical technique. The tumor growth curve was drawn and the inhibition ratio of tumor growth was calculated. Results NIM could significantly inhibit the glioma xenografts growth with its inhibition rate reaching 42.03%. The mRNA expression of Ang-2 gene in NIM treatment group (0.2032±0.0185) was significantly lower than that in control group (0.6024±0.0289, P＜0.05), but that of Ang-1 gene showed no significant changes; therefore, the mRNA ratio of Ang-2/Ang-1 genes was decreased (0.5825±0.0621 vs. 1.5847±0.1948, P＜0.05). MVD in the xenografts of the NIM treatment group was significantly lower than that in the control group (P＜0.05). Conclusion NIM, by down-regulating the mRNA expression ofA ng-2 gene and changing the mRNA ratio of Ang-2/Ang-1 genes, can inhibit the tumor growth
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Objective To explore the effect of chondroitin sulfate enzyme ABC (chABC) on glial scar in rat models of brain traumatic injury (TBI). Methods Thirty-eight Wistar rats were randomly divided into 5 groups, including normal control group (n=2), model group (rat models of TBI,n=9), 1.0 U/mL chABC treatment group (n=9), 2.5 U/ml chABC treatment group (n=9) and 5.0 U/ml chABC treatment group (n=9). After performing TBI by free falling in the later 4 groups, rats of the model group were given no treatment, while those of the other 3 groups were administrated with different concentrations of chABC by local injection respectively. One, 2 and 4 w after TBI, HE staining was performed on the brain tissues of these rat models;and immunohistochemical assay and Western blotting were employed to evaluate the secreting of chondroitin sulfate proteoglycans (CSPGs) and the therapeutic effect of chABC on glial scar. Data were statistically analyzed using t-test. Results Pathological test revealed the scars in the treatment groups were significantly fewer than those in the model group 2 w after TBI, with 5.0 U/mL chABC treatment group enjoying the fewest level (P<0.05). Immunohistochemical assay showed that the secreting of CSPGs in the treatment groups and model group was significantly increased than that in normal control group 2 w after TBI (P<0.05);the 5.0 U/ml chABC treatment group showed an obvious reduction of CSPGs secreting as compared with the model group (P<0.05). Western blotting indicated that the treatment groups showed an obvious reduction of CSPGs secreting as compared with the model group 1, 2 and 4 w after TBI (P<0.05);an obvious gradual reduction of CSPGs secreting in the model group, 2.5 and 5.0 U/ml chABC treatment groups was noted 1, 2 and 4 w after TBI (P<0.05). Conclusion ChABC could degrade the glial scar by degrading the CSPGs molecules and improve the microenvironment of local axonal regeneration after TBI;In this experiment, the highest concentration of chABC (5U/ml) shows the best effect on removing the glial scar.
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Objective To investigate the effects of transient axonal glycoprotein-1 (TAG-1) on activity of U251 cells and expressions of AICD, p53 and EGFR genes in the cells. Methods The viability of U251 cells was tested by MTT assay at 48 h following the addition of various concentrations of TAG-1 (0, 5, 10 and 20 μg/mL). The expression ofamyloid precursor protein (ALP) was detected by immunofluorescent staining. The apoptotic cells were examined by TUNEL. Real-time PCR was employed to detect the influence of TAG-1 on the expressions of AICD, p53 and EGFR genes in U251 cells. Results TAG-1 did not play an inhibitory effect on the proliferation of the U251 cells. APP was abundantly expressed on membrane of the U251 cells. U251 cells did not show apoptotic cells but increased expressions of AICD, p53 and EGFR genes were noted when U251 cells were exposed at 10 μg/mL of TAG-1. Conclusion TAG-1 plays an important role in regulating the proliferation of glioma and may not induce the apoptosis of U251 cells through the signal pathway of TAG-1/APP/AICD/p53 or TAG- 1/APP/AICD/EGFR.
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Objective To detect the immunogenicity of the recombinant DNA vaccine that encoded for neurite growth inhibitors: Nogo-A, oligodendrocyte myelin glycoprotein (OMgp), tenascin-R (TN-R) and myelin-associated glycoprotein (MAG) after the nerve injury under the help of pAdEasy, a kind of adenovirus plasmid being the vector of the DNA. Methods Sixteen 5-w-old Lewis rats were randomized into DNA vaccination group (vaccine group) and pAdEasy group. Rats in the vaccine group were immunized once weekly for a consecutive 8 w by bilateral injection of the recombinant plasmid into the musculus tibialis. The immunized animals in the 2 groups were exsanguinated each time before the vaccination for sera collection, and the qualitation and quantitation of the antibodies in the serum were detected by Dot-blot analysis and ELISA. Results The vaccine group could produce fusion-protein antibodies against Nogo-A, MAG, OMgp and TN-R at the 6th w of vaccine injection, while pAdEasy group could not. The valency of antiserum was shown by ELISA as 1:1 000 000 at the 6th w of vaccine injection and kept this level stably. Conclusion The DNA vaccine exclusively induces the generation of the fusion-protein antibodies against Nogo-A, MAG, OMgp and TN-R in vivo, which controls the favorable immunogenicity.
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Objective To offered some prophase works by preparing Neurocan protein, antiserum, and assaying their characteristics, in order to construct the isopropy-β-D-thiogalactoside (IPTG)-participated DNA vaccine, which can neutralize the inhibitors in the injured CNS following the immune administration and then promote the nerve regeneration. Methods Neurocan gene was syntbetized with HisTag label in beginning and enzyme-cut sites at amphi- of the sequence. The prokaryotic expression plasmid, PET30a-Neurocan, was constructed as usual, converted into the Escherichia coli, and induced by IPTG to express positively. The interest protein was identified by SDS-PAGE and Western blot respectively. The preimmune serum was as the negative control during the ELISA assay of antiserum valency. The immune serum was as the first antibody, and the goat-anti-rabbit labeling with alkaline phosphatase (AP) was employed as the second one. Coloration was with NBT/BCIP method. Results The correct sequence of the synthetic Neurocan gene was clearly showed by identification with enzyme-cut, PCR and sequencing. The Neurocan protein expressed by prokaryotic showed its molecular weigh as 55 000 following the SDS-PAGE identification, and it could specifically bind with anti-HisTag, which implied the interesting protein just as the expression product of Neurocan gene. The valency of antiserum was shown by ELISA as 1:1 000 000, the purpose strap of which was confirmed by Western blot. Conclusions Neurocan protein could be successfully expressed in prokaryotic, the antibody of which could be specifically obtained by immune administration to the rabbit. The Neuroncan antibody could bind with the Neurocan protein specifically.
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Objective To analyze the feasibility of local LINGO-1 polyclonal antibody administration for treatment of spinal cord injury in adult rats. Methods Twenty-four adult female SD rats were randomized into sham-operated group, rabbit IgG group and LINGO-1 antibody group. In the latter two groups, partial transaction of the T9 segment of the spinal cord was performed to completely sever the dorsal eorticospinal tract, followed immediately by administration of rabbit IgG and anti-LINGO polyclonal antibody via a mini-osmotic pump, respectively. At 3 and 28 days after the operation, the T8～10 segments of the spinal cord were harvested to prepare cryosections, and immunofluorescence staining was used to analyze the penetration of LINGO-1 polyclonal antibody into the spinal cord tissue and its specific binding to LINGO-1 molecules. Results In LINGO-1 antibody group, the presence of rabbit antibodies was detected at the injured sites of the spinal cord at 3 and 28 days after the operation. The mean immunofluorescence density was significantly lower in L1NGO-1 antibody group than in rabbit IgG group at 3 days after the operation (P<0.05). In rabbit IgG group, the mean immunofluorescence density for LINGO-1 in the crysections pre-treated with LINGO-1 polyclonal antibody was significantly lower than that in sections pre-treated with rabbit IgG(P<0.05). Conclusion Locally administered LINGO-1 polyclonal antibody can penetrate into the injured sites in the spinal cord in a wide time window and recognizes LINGO-1 molecule specifically, suggesting the feasibility of passive immunotherapy for spinal cord injury.
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Objective To observe the time course of changes in synaptophysin (P38) expression in the cortex and hippocampus of rats with posttraumatic epilepsy (PTE), and explore the role of synaptic plasticity in the epileptogenesis of PTE. Methods Thirty-seven male Sprague-Dawley rats were randomized into normal control group (n=5), sham-operated group (n=12) with intracortical saline injection, and PTE model group (n=20) with stereotactic FeCl<,2> injection (0.1 mol/L, 10 μ1) into the motor cortex. The expression of P38 in the brain cortex and hippocampus of the rats was detected immunohistochemically at 1 h and 7, 14 and 30 days after the injections. Results Most of the rats with FeCl<,2> injection developed isolated epileptiform discharges soon alter the injection. Compared with the sham-operated groups, the rats in PTE group showed significantly decreased P38 expression in the right frontal cortex at all the time points of measurement (P<0.05). At 1 h after FeCl<,2> injection, P38 expression in the polymorphic layer, stratum lacunosum and stratum radiatum of the right hippocampai CA3 area and DG molecular layer underwent no significant changes (P>05), but at 7 days, the expression increased significantly in all the stratum regions of the right hippocampal CA3 area, and this high expression level was maintained till 30 days after the injection. Conclusion Synaptic plasticity alterations in relation to P38 expression changes in the cortex and hippocampus may play an important role in the epileptogenesis of PTE in this rat model.
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Objective To analyze the gene expression profiles in relation to the migration ability of adult human bone marrow-derived neural stem cells (Md-NSCs), and identify the genetic basis of the high migration potential of Md-NSCs in the central nervous system (CNS). Methods Adult human bone marrow stromal celIs(BMSCs) obtained from adult healthy volunteers were induced to differentiate into Md-NSCs in vitro, and the expressions of the genes related to cell invasiveness and metastasis were investigated by microarray analysis. Quantitative real-time PCR (RT-PCR) was used to verify the microarray results. Results The results of microarray analysis revealed significant overexpressions of the genes MMP1, MMP2, MMP17, ITGA3, RhoB, RhoC and RhoD in the Md-NSCs as compared with the expressions in fresh normal human adult bone marrow cells depleted of red blood cells. Quantitative RT-PCR verified the overexpression ofMMP2 gene by 2.84×100 folds, ITGA3 gene by 2.22×102folds, and RhoC gene by 4.92×100 folds. Conclusion The high migration potential of the Md-NSCs in the CNS is probably associated with the overexpression of the genes that promote cell invasiveness and metastasis. These overexpressed genes are also important oncogenes, and therefore the tumorigenicity of the Md-NSCs warrants further investigation.
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Objective To establish a rat model of cerebral aneurysms and explore the impact of hypertension on it. Methods Forty-five rats were randomly divided into hypertensive, normotensive, and normal control groups (n=15). The origin of the right external carotid artery was digested with porcine pancreatic elastase, ligated and cut at 1.5 mm from the carotid bifurcation. Cerebral aneurysm models were established in this stump in the hypertensive and normotensive groups, and then, stenosis of the bilateral renal artery was induced surgically in the hypertensive group. The systolic blood pressures in the 3 groups were measured before and at 6 and 12 weeks after the operation. At 12 weeks after the operation, the aneurysms, after measurement of the size, were fixed by formalin perfusion. The vascular tissues in the aneurysms were isolated for pathological examination using HE staining, Van-Geson staining and Verhoeff staining. Results A significant increase in the blood pressure occurred in the hypertensive group to the level of 197.48±15.44 mm Hg, and the aneurysm was obviously enlarged measuring 2.38±0.31 mm in length and 1.89±0.35 mm in width;no significant changes occurred in the normotensive and normal control groups. Pathological examinations demonstrated the absence of the intima and rupture of the elastin layer in the hypertensive group;the normotensive group retained part of the elastic fibers, and no vascular damage was found in the normal control group. Conclusion This aneurysm model can be prepared conveniently with good stability, and can well simulate the structure and pathology of human cerebral aneurysm. Hypertension significantly affects the elastin and collagen in the blood vessels to contribute to aneurysm enlargement.
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Objective To construct an aneurismal model with estrogen deficiency and investigate the mechanism of estrogen deficiency in the formation and development of intracranial aneurysm. Methods Female Wistar rats were randomly divided into experimental, sham-operative and blank control groups (n=10). Rats in the experimental group were ovariectomized and those in the sham-operative group were removed the adipose issue nearby the ovary only; while the rats in the blank control group were done nothing. Two weeks after the ovariectomized or sham operation, elastase dropped around the right external carotid artery and the crotch of the carotid artery and the carotid artery was ligated by two lines at 1.5 mm far from the crotch, and then sheared between the two lines to successfully induce the aneurysm. At 6 weeks of the successful construction of aneurysm model, the estrogen was detected and the aneurysm was harvested for pathological staining. Results The experimental group showed a lower estrogen level (105.00±12.96 pmol/L) than the sham-operative group (178.50±25.96 pmol/L) and the blank control group (180.40±18.70 pmol/L, P<0.05). Aneurismal length dilatation rates in the experimental group and the sham-operative group were (131.31±6.63)% and (109.90±3.44) %, respectively (P<0.05). Aneurismal diameter dilatation rates in the experimental group and sham-operative group were (125.10±5.49) % and (106.82±2.49) %, respectively (P<0.05). Conclusion Estrogen deficiency may promote the formation and development of the intracranial aneurysm. This experiment provides a simple model for investigating the relationship between estrogen deficiency and aneurysm development.
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<p><b>OBJECTIVE</b>To express and purify the fusion protein of extracellular domain of human Ig domain-containing, neurite outgrowth inhibitor (Nogo) receptor-interacting protein-1 (LINGO-1(aa76-319)) in prokaryotic cells and prepare the rabbit anti-LINGO-1 polyclonal antibody (pAb).</p><p><b>METHODS</b>The 732 bp DNA sequence of hLINGO-1(aa76-319) was obtained from pCMV-SPORT6 by PCR and inserted into pET30a(+) plasmid to construct the prokaryotic expression plasmid pET30a(+)-hLINGO-1(aa76-319), which was subsequently transformed into E.coli. The target fusion protein was expressed with IPTG induction and purified by Ni(2+)-NTA affinity chromatography column. The antiserum against hLINGO-1(aa76-319) was obtained from the rabbits immunized with hLINGO-1(aa76-319), and the titer of the pAb was determined using enzyme linked immunosorbent assay (ELISA) and its specificity identified using Western blotting.</p><p><b>RESULTS</b>The prokaryotic expression plasmid pET30a(+)-hLINGO-1(aa76-319) was constructed successfully. Efficient expression of the target fusion protein was achieved with IPTG induction at the optimal concentration of 0.4 mmol/L and culture temperature at 37 degrees celsius; for 2.5 h. The hLINGO-1(aa76-319) fusion protein was effectively expressed in E.coli as inclusion bodies, and the soluble protein was obtained through denaturation and refolding procedures, and the purified fusion protein showed a purity above 90%. The titer of the anti-hLINGO-1(aa76-319) pAb obtained by immunizing the rabbits with the purified protein reached 1:1.6x10(6), and Western blotting confirmed its good specificity.</p><p><b>CONCLUSION</b>The fusion protein hLINGO-1(aa76-319) with high purity has been obtained and the anti-hLINGO-1(aa76-319) pAb obtained shows a high titer and good specificity, which provide important experimental basis for further functional investigation of LINGO-1.</p>
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Animaux , Humains , Lapins , Anticorps , Allergie et immunologie , Spécificité des anticorps , Escherichia coli , Génétique , Métabolisme , Sérums immuns , Allergie et immunologie , Protéines membranaires , Génétique , Allergie et immunologie , Protéines de tissu nerveux , Génétique , Allergie et immunologie , Plasmides , Génétique , Protéines de fusion recombinantes , Génétique , Allergie et immunologieRÉSUMÉ
Objective To explore the effect of edaravone (ED) on the neurological functionaldeficits, apoptosis and expression of caspase-3 protein following focal cerebral ischemia/reperfusion(I/R)injury in rats. Methods A total of 24 male Sprague-Dawley (SD) rats were randomly allocated intothe sham-operation group, cerebral I/R group, normal saline treatment group and ED treatment group, 6rats in each group. Rat models with focal cerebral I/R injury induced by middle cerebral artery occlusion(MCAO) were established using a modified suture method. ED (3mg/kg) or equal volume of normalsaline was injected intraperitoneally immediately after cerebral ischemia and 12 h after reperfusion in thetreatment groups;the rats in sham-operation group underwent the same modeling procedure withoutischemia by nylon suture. The neurological behavioral deficits were evaluated 24 h after I/R injury;,immunohistochemical staining and Western blot assay were applied to detect the change in the expressionof caspase-3 protein; in situ TdT-mediated dUTP-biotin nick end labeling (TUNEL) assay was used tostudy the change in neuronal apoptosis. Results The scores of neurological behavioral deficit scale,the positive cells and expression of caspase-3 protein, and the apoptotic cells in the ED treatment groupwere significantly decreased, compared with that of the I/R group and normal saline treatment group(P<0.05 for each comparison). Conclusion ED may effectively reduce neuronal apuptosis andneurological functional deficits after cerebral I/R injury, which might be related with the inhibition of thecaspase-3 protein expression.
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<p><b>OBJECTIVE</b>To study the effect of superparamgnetic iron oxides (ferumoxides) on the survival and proliferation of neural stem cells (NSCs) and determine the optimal ferumoxides concentration for labeling.</p><p><b>METHODS</b>Bone marrow stromal cells (BMSCs) were obtained from rat femoral marrow and cultured in vitro to induce their differentiation into NSCs. Ferumoxides labeling of the NSCs was performed with different final concentrations of ferumoxides, and the labeling efficiency and viability of the labeled NSCs were evaluated by Prussian blue staining, MTT assay, flow cytometry and transmission electron microscope.</p><p><b>RESULTS</b>The NSCs could be effectively labeled with ferumoxides with a labeling efficiency of around 90%. Prussian blue staining showed numerous fine granules with blue staining in the cytoplasm of the labeled NSCs, and the intensity of the blue staining was in positive correlation with the ferumoxide concentration for labeling. Transmission electron microscopy of the labeled NSCs revealed the presence of numerous vesicles spreading in the cytoplasm and filled with electron-dense magnetic iron particles. The ferumoxides vesicles increased with the labeling concentration of ferumoxides, and at the final concentration exceeding 25 microg/ml, ferumoxides vesicles in the NSCs gave rise to conglomeration which hampered observation of the cellular ultrastructure by transmission electron microscope. The results of flow cytometry and MTT assay demonstrated that the cell viability, proliferation, differentiation and apoptosis of the labeled cells were affected by ferumoxides at the concentration above 25 microg/ml, but such effects could be minimal at lower concentrations.</p><p><b>CONCLUSION</b>Ferumoxides might be feasible for in vitro labeling of the NSCs with the optimal concentration of 25 microg/ml.</p>
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Animaux , Mâle , Rats , Prolifération cellulaire , Survie cellulaire , Cellules cultivées , Dextrane , Oxyde ferrosoferrique , Fer , Pharmacologie , Nanoparticules de magnétite , Microscopie électronique à transmission , Neurones , Biologie cellulaire , Oxydes , Pharmacologie , Cellules souches , Biologie cellulaireRÉSUMÉ
Objective To investigate the photodynamic effect mediated with 5-aminolevulinic acid (5-ALA) on U251 human glioma cells. Methods Fluorescence microscope and confocal laser scanning microscope were used to detect the localization of Pp Ⅸ in U251 human glioma cells. The cells with/without 5-ALA were irradiated at the wavelength of 635 nm. MTT assay was used to measure the cell survival after laser irradiation. Results 5-ALA cocultured with U251 cells successfully produced endogenous Pp Ⅸthat was observed distributively in the cytoplasm, but not in nuclear region. The overall survival rates of the U251 glioma cells photodamaged by ALA-PDT decreased as the incubation time went by or the 5-ALA concentration increased, while peaked at the incubation time of 6 h and the 5-ALA concentration of 2.0mmol/L. Without one of 5-ALA and light irradiation, the survival rate of the cells had no significant difference compared with that of cells of the control group. Conclusion The 5-ALA-induced PDT appears to be a promising therapy for human glioma. The optimal incubation time may be 6 h and the optimal 5-ALA concentration be 2.0 mmol/L.
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Objective To explore the feasibility of recently developed nucleofection method in delivering plamid DNA directly into the nucleus for the introduction of a plasmid encoding enhanced green fluorescent protein (EGFP) into primary bone marrow stromal cells (BMSCs) of rabbit. Methods Rabbit BMSCs were harvested by means of density gradient centrifugation following a thighbone puncture. The primary BMSCs were cultured and either transfected with pEGFP-C2 by nucleofector technology (as EGFP group) or uninfected (as control) in vitro. Compared with the control, the cellular viability, adhesive rates and the growth curves of the labeled cells were respectively analyzed. Transfection efficiencies were evaluated through the detection of EGFP expression. Results EGFP were successfully expressed 24 h after nucleofection. Similar morphological development, adhesive rates and growth curves were found in the 2 groups. The positive EGFP expression was enhanced gradually alone with the prolonged culture time, and showed the strongest 6 d after marked, with about 47.8% of EGFP-positive cells in the total BMSCs. The EGFP did not attenuate even 1 month after the marking. Conclusion Neuclofection of pEGFP-C2 shows no significant effect on the proliferation of rabbit BMSCs. EGFP plays an important role in stable gene marking of rabbit BMSCs. Nucleofection is an efficient nonviral gene transfer method for the introduction of genes into primary rabbit BMSCs.
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<p><b>OBJECTIVE</b>To investigate the effect of N-acetyl-cysteine (NAC) and depakine (DP) on the changes of membrane potential and peroxidate in rat cortex neurons exposed to ferrous chloride (FeCl(2)).</p><p><b>METHODS</b>Cultured cortex neurons of newly born SD rats were randomly divided into control group (PBS group), model group (FeCl(2) group), NAC pretreatment group (NAC group), DP pretreatment group (DP group) and NAC+DP pretreatment group (NAC+DP group). In the latter three groups, NAC (0.08 mg/ml) and DP (0.1 mg/ml) were added in the cell culture 2 and 3 h before FeCl(2) (1 mmol/L) exposure, respectively. After exposure to FeCl(2), the membrane potential of the neurons was detected with fluorescent dye DiBAC4(3) (bis-(1,3-dibutylbarbituric acid) trimethine oxonol), and the peroxidate level with 2,7-dichlorofluorescin diacetate (H(2)DCF) by laser confocal scanning microscope (LCSM) and nuclear factor-KappaB (NF-KappaB) level with immunocytochemistry.</p><p><b>RESULTS</b>Compared with FeCl(2) group, the expression of NF-KappaB and peroxidate level in the neurons were decreased significantly in NAC and NAC+DP groups (P<0.01), but not in DP group (P>0.05). FeCl(2) depolarized the membrane potential and increased the expression of NF-KappaB in the neurons. Compared with FeCl(2) group, significant changes in the membrane potential were observed in DP and NAC+DP groups (P<0.01) but not in NAC or PBS group (P>0.05).</p><p><b>CONCLUSION</b>Both NAC and DP can protect the neurons from FeCl(2)-induced damage but through different pathways, and their combined use can significantly alleviate neuronal damages due to FeCl(2) exposure. Antioxidants such as NAC in combination with antiepileptic drugs may produce favorable effect in prevention and treatment of posttraumatic epilepsy.</p>