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Ex vivo culture-amplified mesenchymal stem cells (MSCs) have been studied because of their capacity for healing tissue injury. MSC transplantation is a valid approach for promoting the repair of damaged tissues and replacement of lost cells or to safeguard surviving cells, but currently the efficiency of MSC transplantation is constrained by the extensive loss of MSCs during the short post-transplantation period. Hence, strategies to increase the efficacy of MSC treatment are urgently needed. Iron overload, reactive oxygen species deposition, and decreased antioxidant capacity suppress the proliferation and regeneration of MSCs, thereby hastening cell death. Notably, oxidative stress (OS) and deficient antioxidant defense induced by iron overload can result in ferroptosis. Ferroptosis may inhibit cell survival after MSC transplantation, thereby reducing clinical efficacy. In this review, we explore the role of ferroptosis in MSC performance. Given that little research has focused on ferroptosis in transplanted MSCs, further study is urgently needed to enhance the in vivo implantation, function, and duration of MSCs.
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Humans , Antioxidants/metabolism , Ferroptosis , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells , Iron Overload/metabolismABSTRACT
Objective:To evaluate the prognostic effects of gradient boosting machine (GBM) model on the short-term effects of percutaneous endoscopic lumbar discectomy (PELD) in the treatment of lumbar disc herniation.Methods:Clinical data and outcomes of 475 patients who underwent PELD surgery for single-segment lumbar disc herniation from October 2016 to March 2018 were retrospectively collected. The lumbar JOA score was used as a reference for the evaluation of curative effects. The improvement rate ≥50% was considered as good curative effects, while <50% was considered as poor curative effects. GBM model and multivariate Logistic regression model were utilized to screen out the influencing factors of the short-term clinical effects of PELD. Prognostic models were established, receiver operating characteristic (ROC) curves were drawn and compared. Sensitivity, specificity and Youden index were compared to evaluate the predictive performance of GBM model.Results:A total of 395 patients were followed up effectively for 24 months. There were 347 patients (87.8%) with good curative effects. However, forty-eight patients (12.2%) had poor curative effects. There were statistically differences in the lumbar JOA score improvement rates between the groups in regards to age, location and type of herniated disc, degeneration level of intervertebral disc and facet joint in surgical segment, sagittal diameter of the protrusion and whether or not there was calcification, onset time to the surgery time period and degeneration level of intervertebral disc in adjacent segment ( P<0.05). The results of multivariate analysis showed that patients with age ≥60 [ OR=9.15, 95% CI(4.04, 20.73), P<0.001] and with larger sagittal diameter of the protrusion [ OR=1.37, 95% CI(1.18, 1.58), P<0.001] were more likely to have a poor prognosis. Patients with unilateral disc herniation had a better prognosis than the extreme lateral type [ OR=0.17, 95% CI(0.06, 0.55), P=0.003]. The prognoses of patients with grade Ⅲ intervertebral disc degeneration in surgical segment were worse than those with grade Ⅱ [ OR=0.17, 95% CI(0.04, 0.70), P=0.014]. The prognoses of patients with grade Ⅲ intervertebral disc degeneration in adjacent segment were worse than those with grade Ⅱ [ OR=0.29, 95% CI(0.10, 0.81), P=0.018]. The AUC predicted by GBM model was 0.92 [95% CI(0.77, 0.96)] with 93.46% sensitivity, 83.33% specificity and 0.77 Youden index. The above parameters were higher than those by the Logistic regression model. The predictive effects of the two models were both statistically significant ( P<0.001). The AUC values of the two models were also statistically significant ( Z=0.11, P<0.001). Conclusion:GBM model is better than multivariate logistic regression analysis model in predicting the short-term clinical effects of PELD in treating lumbar disc herniation.
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Objective To evaluate the role of spinal nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway in hydrogen-induced reduction of inflammatory pain in rats.Methods Sixty-four SPF healthy adult male Sprague-Dawley rats,weighing 200-250 g,were divided into 4 groups (n =16 each) using a random number table:control group (group C),inflammatory pain group (group IP),inflammatory pain plus hydrogen-rich saline group (group IP+H2) and inflammatory pain plus hydrogen-rich saline plus Nrf2 inhibitor all-trans retinoic acid (ATRA) group (group IP+H2+ATRA).Chronic inflammatory pain was induced by injecting complete Freund's adjuvant (CFA) 100 μl into the plantar surface of the left hind paw in IP group and IP+H2 group.The equal volume of normal saline was given instead in group C.Hydrogen-rich saline 5 ml/kg was injected intraperitoneally once a day for 7consecutive days starting from 1 day after injecting CFA in group IP+H2 and group IP+H2+ATRA,and the equal volume of normal saline was given instead in the other groups.ATRA 7 mg/kg was injected intraperitoneally once a day for 2 consecutive days starting from 2 days before injecting CFA.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured at 1 day before establishing the model (T0) and 1,3 and 7 days after establishing the model (T1-3).Six rats were sacrificed after the last measurement of pain threshold on day 7 after establishing the model,and the L4-6 lumbar segments of the spinal cord were removed for determination of the expression of Nrf2,HO-1 and glial fibrillary acidic protein (GFAP) by Western blot.Results Compared with group C,the MWT was significantly decreased and the TWL was shortened at T1-3,and the expression of Nrf2,HO-1 and GFAP was up-regulated in IP and IP+H2 groups (P＜0.05).Compared with group IP,the MWT was significantly increased and the TWL was prolonged at T1-3,the expression of Nrf2 and HO-1 was up-regulated,and the expression of GFAP was down-regulated in group IP+H2 (P＜0.05),and no significant change was found in the parameters mentioned above in group IP+H2+ATRA (P＞0.05).Compared with group IP+H2,the MWT was significantly decreased and the TWL was shortened at T1-3,the expression of Nrf2 and HO-1 was down-regulated,and the expression of GFAP was up-regulated in group IP+H2+ATRA (P＜0.05).Conclusion Activation of spinal Nrf2/HO-1 signaling pathway is involved in hydrogen-induced reduction of infflammatory pain in rats.
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Lung cancer has become one of common malignant tumors, and an increasing mortality of lung cancer is mainly due to induction of resistance to chemotherapeutic agents. However, the molecular mechanism of drug resistance in lung cancer remains poorly understood. Many studies have shown that both overexpression of drug resistance genes and dysregulation of signal pathways are involved in the drug resistance. MicroRNAs (miRNAs), a class of endogenous non-coding small RNA molecules, are closely correlated with cell growth, apoptosis and signal transduction. Meanwhile, drug metabolism in vivo can also be regulated by miRNA. Moreover, miRNA also plays an important role in drug resistance of tumor cells. This paper will highlight the potential of miRNA as suppressors and biomarkers for chemoresistance and prognosis in lung cancer.
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Objective To evaluate the influence of autophagy on pain behavioristics and astrocytic activation in rats with inflammatory pain.Methods Seventy-eight clean male Sprague-Dawley (SD) adult rats were randomly divided into four groups: control group (n = 12), model group (n = 42), autophagy inducer rapamycin (Rap) pretreatment group (n = 12) and autophagy inhibitor 3 methyladenine (3-MA) pretreatment group (n = 12). The inflammatory pain rat model was reproduced by subcutaneous injection of freund's complete adjuvant (CFA) 100μL at foot sole, whilein control group, the same volume 0.9% normal saline 100μL was injected at the same site. One hour before modeling, Rap 10 mg/kg and 3-MA 15 mg/kg were intraperitoneally injected in rats in Rap and 3-MA pretreatment groups respectively, and the same volume of 0.9% normal saline was injected intraperitoneally in rats of control and model groups. Before modeling and 6, 12, 24 hours and 3 days after modeling, the L4-L6 spinal cord tissue was harvested from 6 rats in model group, and autophagy protein membrane microtubule-associated protein 1 light chain 3 Ⅱ (LC3 Ⅱ) and autophagy related gene Beclin-1 expressions were detected by Western Blot in the tissue; the changes of pain behavioral indexes mechanical withdraw threshold (MWT) and thermal withdrawal latency (TWL,n = 6), were observed at6, 12, 24 hours and 3 days, 7 days after modeling in the 6 rats taken from each group; in another 6 rats in each group, 24 hours after modeling, L4-L6 spinal cord tissue was collected, immunofluorescence staining was used to observe the changes of astrocytes and the positive expression of glial fibrillary acidic protein (GFAP) under a confocal microscopy, and the protein expression quantity of GFAP was detected by Western Blot in the tissue.Results ① The inflammatory pain could induce the increase of rat autophagy protein LC3Ⅱ and Beclin-1 expressions in spinal cord tissue, reaching their peaks at 24 hours (A value: 0.59±0.07, 0.51±0.06, respectively), and then they were gradually decreased. ② With the prolongation of time, in the model group MWT was gradually decreased, TWL was gradually shortened, they reached their valley values at 24 hours after modeling [MWT (g): 17.8±1.9, TWL (s): 6.8±0.4], and from 12 hours they were significantly decreased compared with those in control group [12hours MWT (g): 21.5±2.4 vs. 43.4±5.1, TWL (s): 12.0±1.1 vs. 17.6±1.2, bothP < 0.05], after modeling for 3 days they were increased; Compared with model group, 12 hours after autophagy inducer Rap was given, MWT was significantly increased (g: 36.8±4.9 vs. 21.5±2.4,P < 0.05), TWL was significantly prolonged (s: 14.3±1.1 vs. 12.0±1.1,P < 0.05); from 12 hours after autophagy inhibitor 3-MA was given, MWT was further reduced (g: 18.6±1.9 vs. 21.5±2.4, P<0.05), TWL was further shortened (s: 8.4±0.6 vs. 12.0±1.1,P < 0.05). ③ Confocal microscopic findings showed, there was no significant acstrocytic change, and only litter GFAP expression was seen in control group. In model group, the inflammatory pain induced astrocyte activation, manifesting glial cell hypertrophy, hyperplasia, gelatinousnetwork deformation, and GFAP expression was obviously increased compared with that in the control group (A value: 0.54±0.09 vs. 0.16±0.02,P < 0.05). Since autophagy inducer Rap can decrease astrocyte activation and inhibit GFAP expression, there was statistical significant difference between Rap pretreatment and model groups (A value: 0.33±0.06 vs.0.54±0.09,P < 0.05); autophagy inhibitor 3-MA can further aggravate astrocytes activation and up-regulate GFAP expression in 3-MA pretreatment group (A value: 0.73±0.08 vs. 0.54±0.09,P < 0.05).Conclusion Autophagy participates in the process of astrocytic activation and pain behavioristics in rats with inflammatory pain.
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Objective To investigate the effects of HO/CO pathway on inflammation cytokines in a rat model of incisional pain. Methods Thirty-six rats were executed to collect ipsilateral spinal cord tissues for HO-1 detection by Western blot assay, and cytokines tumor necrosis factor (TNF)-a, interleukin (IL)-1b, IL-6 and high mobility group box (HMGB)1 were detected by ELISA before and at 1, 4, 8, 12 and 24 h after establishing incisional pain model. Additionally, 36 rats without establishment of incisional pain model were used as control group. A total of 144 model rats of incisional pain were divided into incisional pain (IP) group, IP+hemin group (100 mg/kg hemin was injected by i.p. before operation), IP+Znpp-IX group (45μmoL/kg Znpp-IX was injected by i.p. before operation) and IP+CORM-2 group (10 mg/kg CORM-2 was injected by i.p. before operation). Values of paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) were detected, and expressions of TNF-a, IL-1 b, IL-6 and HMGB1 were measured by ELISA before and at 1, 4, 8, 12 and 24 h after operation. Results Compared with pre-operation of incisional pain in rats, expression levels of HO-1 protein and cytokines TNF-a, IL-1 b, IL-6 and HMGB1 were increased at 1, 4, 8, 12 and 24 h after operation (P PWTL were decreased and cytokines TNF-α, IL-1β, IL-6 and HMGB1 were increased in IP+Znpp-IX group (P<0.05). Conclusion Incisional pain can increase the expression of HO-1, and HO-1/CO pathway exists the regulatory effect on inflammatory cytokines in the rat model of incisional pain.
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Objective To explore the expressions and.significancse of interleukin (IL)-10 and IL-18 in serum and tissues of patients with cervical intraepithelial neoplasias (CIN) and cervical cancer,and to analyze their relationships with clinical pathological characteristics and prognosis.Methods One hundred and eight patients' tissues and clinical blood samples (68 cases of CIN and 40 cases of squamous cell carcinoma) were enrolled in this study,including 25 with low-grade cervical intraepithelial neoplasias (CIN Ⅰ),43 with high-grade cervical intraepithelial neoplasias (CIN Ⅱ-Ⅲ),and 40 with invasive cervical squamous cell carcinoma (SCC);meanwhile,20 cases normal cervical tissues were enrolled.The expressions of IL-10 and IL-18 in cervical tissues and serum of the studied patients were measured by enzyme-linked immunosorbent assay and polymerase chain reaction.Meanwhile,second generation hybrid capture was used to detect human papilloma virus(HPV) DNA in cervical smears obtained from the studied patients with the different lesions.The relationships among IL-10 and IL-18 with HPV DNA and clinical prognosis were analyzed.Results The expressions of IL-10 and IL-18 in normal control serum were (212.75 ± 62.09),(187.84 ± 81.03)pg/ml respectively.The expressions of IL-10 in CIN Ⅰ,CIN Ⅱ-Ⅲ and SCC serums were (324.71 ±75.87),(397.43 ±68.56),(482.77 ± 104.05) pg/ml,with statistically significant difference (F =17.657,P =0.001).The expressions of IL-18 in CIN Ⅰ,CIN Ⅱ-Ⅲ and SCC serums were (305.53 ± 64.08),(392.74 ± 87.38),(499.86 ± 92.04) pg/ml,with statistically significant difference (F =13.309,P =0.003).The relative expressions of IL-10 in normal control,CIN Ⅰ,CIN Ⅱ-Ⅲ and SCC tissues were 0.99 ±0.01,3.24 ±0.68,7.32 ±0.99,13.24 ± 1.03,with statistically significant difference (F =21.694,P =0.000).The relative expressions of IL-18 in normal control,CIN Ⅰ,CIN Ⅱ-Ⅲ and SCC tissues were 0.98 ± 0.01,2.02 ± 0.84,7.01 ± 1.59,14.38 ± 2.10,with statistically significant difference (F =19.912,P =0.001).The expressions of IL-10 and IL-18 were positively associated with HPV infection (r =0.696,P =0.001;r =0.852,P =0.001).The median survival time of patients with high expressions of IL-10 was 9.74 months,which obviously shorter than those patients with low expressions of IL-10 (24.47 months),with statistically significant difference (x2 =21.363,P =0.001).The median survival time of patients with high expressions of IL-18 was 12.32 months,which obviously shorter than those patients with low expressions of IL-18 (22.88 months),with statistically significant difference (x2 =7.457,P =0.006).Conclusion High expressions of IL-10 and IL-18 are observed in patients with CIN and SCC,which can be used as biomarkers for predicting early cervical lesions.
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Objective To observe the brain regions activated during calculation in patients with left temporal lobe epilepsy (TLE) and in normal subjects.Methods Functional magnetic resonance imaging (fMRI) was applied.Sixteen right-handed persons with left TLE were selected as the left TLE group,and sixteen healthy volunteers were recruited as a control group.The fMRI data was collected as each subject performed simple additions,subtractions and abdication subtractions.Statistical parametric mapping was used to compare the activated brain regions between the two groups.Results The error rate in the calculations was significantly higher in the left TLE group,and their average reaction time was significantly longer.There were aslo significant differences between the two groups in terms of brain activation patterns.Compared with the control group,the left TLE group exhibited hypo-activity in regions such as the left paracentral lobule,the posterior central gyrus,the bilateral inferior parietal lobule,the left angular gyrus,the bilateral supramarginal gyrus,the left middle frontal gyrus,the left superior gyrus,and also in the bilateral posterior cingulate,insular lobule,superior and inferior temporal gyrus,right hippocampus,parahippocampal gyrus,thalamus and cerebellum.The TLE subjects exhibited hyper-activity in the bilateral superior parietal lobule,the bilateral anterior cingulate,as well as in the right,middle and inferior frontal gyrus.Conclusion Our results support a significant functional reorganization of calculation-related neuronal networks within and between the hemispheres in TLE patients.The frontal and parietal lobes may play a compensatory role in the reorganization of the calculation function.Task-related fMRI technology can provide useful information for non-invasive assessment of mathematical computing and cognitive function in TLE patients.
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Objective To compare the clinical effects of hip replacement and internal lixation treatment for aged patients with fracture of femoral neck.Methods One hundred and twelve cases patients with fracture of femoral neck were choosed and divided into the control group (n =56) and observation group (n =56) according to the will of patients and family.The control group was treated by incision fixation while the observation group was given hip replacement therapy.All patients were followed up for 6 months after the operation time.Intraoperative blood loss,hospital stay,bed time,postoperative complications and Harris joint scores of the two groups were compared.Results The operation time and intraoperative blood loss of the observation group were significantly higher than those of the control group((98.6±23.8) min vs.(54.2± 16.4) min,(324.6 ±43.8) ml vs.(158.6±26.8) ml;t=4.468,5.624;P＜0.05);The bed time was much shorter than that of the control group((16.6±2.8) d vs.(68.6±5.8) d;t=8.248,P＜0.05).The case of pressure sores,lung infection and mode again of the observation group were significantly less than those of the control group(P＜0.05),while the Harris joint scores were significantly higher than the control group (89.7％ vs 58.9％,x2 =14.423,P ＜0.05).Conclusion Hip replacement can improve the joint function and enhance the quality of life for patients of fracture of femoral neck.
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[Summary] Lumbar disc herniation is rare in juveniles , which makes it more difficult to diagnose and treat .The prevalence , causes and risk factors , pathological changes , clinical characteristics , main treatment methods , and curative effects of lumbar disc herniation in juveniles were summarized in this review , for benefiting clinical diagnosis and treatment .
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Objective:To investigate the possible role of miR-181d in regulating the multidrug resistance (MDR) of small cell lung cancer (SCLC) and its clinical significance. Methods: Quantitative reverse transcriptase-polymerase chain reaction (QRT-PCR) and Western blot were used to investigate the differential expression of miR-181d and BCL2 from mRNA and protein levels in the chemo-sensitivity cell H69 and the chemo-resistance cell H69AR. The miR-181d expression in H69AR was then upregulated. More-over, CCK8 assay was employed to detect the sensitivities of the cells to chemotherapy drugs, such as ADM, DDP, and VP-16. Mean-while, the expression of miR-181d in the specimens of 87 cases with SCLC were detected using QRT-PCR. All patients received the chemotherapeutic regimen of EP (etoposide+cisplatin). Correlation of the miR-181d expression with clinicopathological features, prog-nosis, and survival time of the patients was studied. Results:miR-181d was downregulated in the SCLC multidrug-resistant cell line H69AR and chemo-resistant patients. Moreover, miR-181d was concurrent with the upregulation of BCL2 protein compared with the parental H69 cell line and chemo-sensitive patients (P<0.001). miR-181d expression in H69 cells resistant to chemotherapy drugs (ADM, DDP, and VP-16) was inhibited (P<0.01). Enforced miR-181d expression reduced the BCL2 protein level and sensitized H69AR cells to chemotherapy drugs (P<0.01). miR-181d expression was associated with tumor stage, sensitivity of chemotherapy, and survival time (all P<0.001). Patients with high miR-181d expression had longer overall survival and progress-free survival time com-pared with those with low miR-181d expression (P<0.001). Conclusion: miR-181d may play a role in the development of MDR in SCLC and may be a potential predictive factor for treatment efficacy.
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In the span of the interactions between cells and biomaterials, cell adhesion is the first biological behavior which has important effects on the following biological behaviors including cell migration, proliferation, and differentiation. So how to improve cell adhesion of biomaterials has become an important subject of tissue engi- neering. One of the popular methods is the surface modification of biomaterials. This article reviews the development of the research on the surface modification of biomaterials for improving cell adhesion.
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@#ObjectiveTo investigate bone marrow mesenchymal stem cells(BMSC) express brain derived neurotrophic factor(BDNF) and nerve growth factor(NGF) and their protective effect for neural stem cells (NSCs).MethodsBMSC were obtained from rat tibiae and femurs and centrifuged with Ficoll. The passage 3 cells were chosen to make immunocytochemical stain for CD44, CD71 and CD45. The expression of BDNF and NGF was detected in BMSC with RT-PCR, as well as in the media with ELISA. The media that cultured BMSC were collected as BMSC condition media. NSCs were obtained from cerebral cortex of new-born rat and cultured in vitro. After different ratio of BMSC condition midia were added, NSCs were induced to apoptosis with heat-shock, then NSCs were dyed with Annexin V-FITC/PI apoptosis kit and apoptosis rates were tested with flow cytometry. ResultsBMSC were CD44(+), CD45(-), CD71(+) and expressed BDNF and NGF mRNA. BDNF and NGF could be tested in the media of cultured BMSC and increase with cultured time. BMSC condition media could reduce the ratio of heat-induced apoptosis of NSCs, and more BMSC condition media showed better effect. ConclusionBMSC can express neurotrophic factores and protect neural stem cells from heat-induced apoptosis.
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To explore the possibility and condition of differentiation of bone marrow mesenchymal cells (BMSCs) to neural cells in vitro, BMSCs from whole bone marrow of rats were cultured. The BMSCs of passage 3 were identified with immunocytochemical staining of CD44 ( + ), CD71 ( + )and CD45(-). There were type Ⅰ and type Ⅱ cells in BMSCs. Type Ⅰ BMSCs were spindleshaped and strong positive in immunocytochemical staining of CD44 and CD71, whereas flat and big type Ⅱ BMSCs were lightly stained. The BMSCs of same passage were induced to differentiate into neural cells by β-mercaptoethanol (BME). After induction by BME, the type Ⅰ BMSCs withdrew to form neuron-like round soma and axon-like and dendrite-like processes, and were stained positively for neurofilament (NF). The type Ⅱ BMSCs did not change in the BME medium and were negatively or slightly stained of NF.
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This study examined the effect of wild-type Smad3 gene on the osteoblastic differentiation of rat bone marrow derived mesenchymal stem cells in vitro. Bone marrow-derived mesenchymal stem cells (MSCs) were stably transfected with the complexes of pcDNA3.0-Myc-Smad3 or pcDNA3.0-Myc-Smad3△C and Lipofectamine reagent. Immunofluorescence staining was performed to evaluate the c-Myc signal in MSCs. The cell proliferation was detected by MTT method. To clarify the osteoblastic characteristics in stably transfected MSCs, alkaline phosphatase (ALP) mRNA and core binding factor α1 (Cbfa1) mRNA were investigated by RT-PCR, and ALP activity and mineralization were examined by p-nitrophenolphosphate method and alizarin red staining respectively. PD98059, a specific inhibitor of the ERK signaling pathway, was used to determine the role of ERK in Smad3-MSCs osteoblastic differentiation. c-Myc signal was detected in Smad3-MSCs and Smad3△C-MSCs. The proliferation of Smad3-MSCs was slower than that of Smad3△C-MSCs or V-MSCs.The relative levels of ALP mRNA and Cbfa1 mRNA in Smad3-MSCs, as well as ALP activity and mineralization, were markedly higher than those in Smad3△C-MSCs or V-MSCs. Although ALP activity and mineralization were slightly lower in Smad3-MSCs.treated with PD98059 than in those without PD98059 treatment, no significant difference was found between them (P＞0.05). It is concluded that the wild-type Smad3 gene, which is a crucial component promoting bone formation,can inhibit the proliferation of MSCs and enhance the osteoblastic differentiation of uncommitted MSCs and the maturation of committed MSCs independent of the ERK signaling pathway.
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To modify the surface property of poly lactide co-glycolide (PLGA) by biomimetic mineralization to construct a new kind of artificial bone. PLGA films and 3 diamensional (3-D) porous scaffolds hydrolyzed in alkaline solution were minerilized in SBF for 14 days. The morphology and composition of the mineral grown on PLGA were analyzed with SEM, FTIR and XRD. The porosity of the scaffolds was detected by using the liquid displacement method. The compressive strength of the scaffolds was detected by using a Shimadzu universal mechanic tester. An obvious mineral coating was detected on the surface of films and scaffolds. The main component of the mineral was carbonated hydroxyapatite (HA) similar to the major mineral component of bone tissues. The porosity of the un-mineralized and mineralized porous scaffolds was (84.86±8.52) % and (79.70±7.70) % respectively. The compressive strength was 0. 784±0. 156 N/mm2 in un-mineralized 3-D porous PLGA and 0. 858±0. 145 N/mm2 in mineralized 3-D porous PLGA. There were no significant differences between the mineralized and un-mineralized scaffolds (P＞0. 05) in porosity and biomechanics. Biomimetic mineralization is a suitable method to construct artificial bone.
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To modify the surface property of poly lactide-co-glycolide (PLGA) by biomimetic mineralization to construct a new kind of artificial bone. PLGA films and 3-diamensional (3-D) porous scaffolds hydrolyzed in alkaline solution were minerilized in SBF for 14 days. The morphology and composition of the mineral grown on PLGA were analyzed with SEM, FTIR and XRD. The porosity of the scaffolds was detected by using the liquid displacement method. The compressive strength of the scaffolds was detected by using a Shimadzu universal mechanic tester. An obvious mineral coating was detected on the surface of films and scaffolds. The main component of the mineral was carbonated hydroxyapatite (HA) similar to the major mineral component of bone tissues. The porosity of the un-mineralized and mineralized porous scaffolds was (84.86 +/- 8.52) % and (79.70 +/- 7.70) % respectively. The compressive strength was 0.784 +/- 0.156 N/mm2 in un-mineralized 3-D porous PLGA and 0.858 +/- 0.145 N/mm2 in mineralized 3-D porous PLGA. There were no significant differences between the mineralized and un-mineralized scaffolds (P > 0.05) in porosity and biomechanics. Biomimetic mineralization is a suitable method to construct artificial bone.
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Biocompatible Materials , Bone Substitutes , Calcification, Physiologic , Durapatite/metabolism , Lactic Acid/chemistry , Polyglycolic Acid/chemistry , Polymers/chemistry , Porosity , Tissue EngineeringABSTRACT
The expression of Smad2 and Smad3 and the influence of exogenous transforming growth factorβ1 (TGFβ1) on them in rat bone marrow-derived mesenchymal stem cells (MSCs) cultured in vitro were investigated. The effects of different concentrations of TGFβ1 on cell proliferation and ALP activity were detected by MTT and PNPP in MSCs respectively. The expression of Smad2 and Smad3 and the influence of exogenous TGFβ1 on them were also examined by immunocytochemistry and Western blot assays. The exogenous TGFβ1 induced a dose-dependent decrease in cell proliferation and a dose-dependent increase in ALP activity, which plateaued at 5 ng/ml. Smad2 and Smad3 proteins were detected only in the cytoplasm in the absence of TGFβ1 and TGFβ1 could stimulate the translocation of them from the cytoplasm to the nucleus. The total amount of Smad2 protein remained unchanged before and after TGFβ1 treatment (P＞0.05). The expression levels of Smad3 remained unchanged after 3 h and 6 h treatment (P＞0. 05), but decreased markedly after 24 h treatment (P＜0.05). It was concluded that TGFβ1 is a latent osteoinductive factor involved in osteoblastic differentiation. Both Samd2 and Smad3 mediate TGFβ1 signaling as downstream mediators in MSCs. The biological output of TGFβ1 triggering the osteoblastic differentiation could be entirely determined by Smad3 in MSCs.
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@#ObjectiveTo observe the expression of apoptosis factor, the mechanism of neuronal apoptosis and profective effect of recombinant Human Erythropoietin (rHu EPO) after spinal cord injury (SCI) in SD rats.Methods30 SD rats were divided into four groups including control group, SCI group, treatment groups A and B.The animal SCI model was established with Allen's method. The changes of nerve functions of rats of 4 groups were observed before and after treating with rHu EPO. The expressions of apoptosis factors (Bcl-2,Bax,Fas) were tested with immunocytochemistry technique, and apoptosis neurones were labeled with TUNEL dyeing.ResultsThe grade of nerve function was improved distinctly in treatment groups, but group B was better than group A.The number of the positive cells for Fas and Bax in SCI group was more than that in treatment groups (P<0.05), and group A was more than group B. The number of Bcl 2 positive cells in the treatment groups was greater than that in SCI group (P<0.05).ConclusionApoptosis is a important death mode of neuron after SCI. rHu EPO can distinctly improve the comeback of the nerve function and protect the nerve tissue.
ABSTRACT
BACKGROUND: Beside direct trauma, a series of secondary pathological changes would occur in local injured spinal cord area during spinal cord injury. It has been reported that recombinant human erythropoietin (rhEPO)could inhibit cell apoptosis and inflammatory reaction, and possess neuroprotective role.OBJECTIVE: To explore the neuroprotective role of rhEPO in spinal cord injury by observing the nerve cell apoptosis and related cytokine expression in traumatic spinal cord.DESIGN: Randomized and controlled study.SETTING: Orthopedic Surgery Laboratory of Affiliated Cooperation Hospital of Tongji Medical College, and Department of Pathology of Tongji Medical College, Central China Science and Technology University.PARTICIPANTS: The study was conduced at Orthopedic Surgery Laboratory of Affiliated Cooperation Hospital of Tongji Medical College, Central China Science and Technology University and Department of Pathology of Tongji Medical College from September 2003 to May 2004. Thirty healthy female adult rats were randomly divided into 4 groups: ① Six rats in blank control group only subjected to spinal cord exposure without injury. ②Eight rats in injury group were subjected to spinal cord injury without medication. ③ Eight rats in medication A group were treated with rhEPO.④ Eight rats in medication B group were treated with thEPO and βaeacine sodium.METHODS: ① Animal model preparation: Spinal cord injury model was established on 24 rats by using improved Allen method. ② Administration: Rats in medication A group were treated with rhEPO in dosage of 300 U/(kg·d) at postoperative 1, 3, 5, 8, 11 days, while rats in medication B group were given additional β-aeacine sodium in dosage of 0.1 mg/kg,once a day for consecutive 11 days. Rats in blank control group and injury group were injected with the same volume physical saline from tail veins.③ Neurological function: The neurological function was scored by the same examiner at 1 day and 12 days after model establishment. Behavioral observation: Basing on improved Gale's neurological functional behavioral analysis, 0 score presented severer dysfunction and 6 scores represents normal. Slope test: The gradient was determined by the grasping capability of rat, which could reflect the recovery of neurological function. ④ Pathological examination: Rat was put to death at postoperative 12 days; traumatic spinal cord was made into slices for HE staining. ⑤ Expression of apoptosis cytokine bcl-2, bax and fas in nerve cells: Specimen was collected for IHC stain and brown colored positive cells was counted for calculating positive expressing rate. ⑥ Apoptosis nerve cells: In situ end-labeling techniques was used to calculate apoptosis index (the number of apoptosis nucleus/total number). All data were analyzed by using paired chi-test.MAIN OUTCOME MEASURES: ① Neurological functional behavioral score and results of slope test. ② Histological observation of traumatic spinal cord. ③ Expression of apoptosis nerve cell cytokines. ④ Examination of apoptostic nerve cells.RESULTS: ① Neurological functional behavioral score and results of slope test: There was no significant difference between 1 day and 12 days in blank control group, while the gradient in traumatic group was significantly larger in 12 days than in 1 day (P ＜ 0.05). In both therapeutic A and B groups, the behavioral scores and slope gradient were found significantly larger at 12 days than 1 day (P ＜ 0.05) and that of traumatic group (P ＜ 0.05). ② Histological observation of traumatic spinal cord: Traumatic spinal cord became slim with a majority of necrosis and glial cell hyperplasia in it; most of neurological tissues were found normal in medication A and B groups, with the neural structure of medication B group better than A group. ③Expression of nerve cell apoptosis cytokines: bax and fas positive cells in traumatic group were more than medication group A and B [traumatic group of (25.75±3.37)% and (41.37±2.83)% vs medication group A of (19.87±3.56) and (26.00±3.29)% vs medication group B of (12.00±2.97)and (17.50±2.20)％, P ＜ 0.05]; bcl-2 was significantly lower in medication group A and group B [(9.75±1.83)％, (14.63±2.83)％, (21.63±5.34)％,P ＜ 0.05]. ④ Examination of apoptotic nerve cells: Cell apeptosis index in traumatic group was significantly higher than medication group A and group B (50.75±5.39, 34.75±3.01, 24.00±3.46, P ＜ 0.05).CONCLUSION: Cell apoptosis is an important kind of neuronal death following spinal cord injury. rhEPO can inhibit nerve cell apoptosis and possess neuroprotective effect for traumatic spinal cord.