Progress in process parameters and mechanism research of polymer emulsion preparation.

As a new type of concrete admixture, polymer emulsion is mainly used to strengthen the properties of concrete by adhesion and physical and chemical crosslinking with cement in concrete. Under the background of construction in the new era, it is of great significance to elucidate all aspects of concrete performance under the action of polymer emulsion. In this paper, the main formation process of polymer emulsion is reviewed, the influence of synthetic materials required for polymerization on the polymerization process is discussed, and the regulating effects of reaction temperature, reaction time, admixtures, and treatment methods on the synthesis process of polymer emulsion are analyzed. The action mechanism of polymer emulsion on concrete was deeply investigated, and the synthesis method was studied to provide an important experimental and theoretical basis for the preparation of new emulsion materials and the process of emulsion polymerization. The problems of polymer emulsion raw materials, synthetic conditions, and synthetic methods are introduced. The future development trend of polymer emulsion is predicted and the future research ideas are put forward.

Targeting foamy macrophages by manipulating ABCA1 expression to facilitate lesion healing in the injured spinal cord.

Spinal cord injury (SCI) triggers a complex cascade of events, including myelin loss, neuronal damage, neuroinflammation, and the accumulation of damaged cells and debris at the injury site. Infiltrating bone marrow derived macrophages (BMDMϕ) migrate to the epicenter of the SCI lesion, where they engulf cell debris including abundant myelin debris to become pro-inflammatory foamy macrophages (foamy Mϕ), participate neuroinflammation, and facilitate the progression of SCI. This study aimed to elucidate the cellular and molecular mechanisms underlying the functional changes in foamy Mϕ and their potential implications for SCI. Contusion at T10 level of the spinal cord was induced using a New York University (NYU) impactor (5 g rod from a height of 6.25 mm) in male mice. ABCA1, an ATP-binding cassette transporter expressed by Mϕ, plays a crucial role in lipid efflux from foamy cells. We observed that foamy Mϕ lacking ABCA1 exhibited increased lipid accumulation and a higher presence of lipid-accumulated foamy Mϕ as well as elevated pro-inflammatory response in vitro and in injured spinal cord. We also found that both genetic and pharmacological enhancement of ABCA1 expression accelerated lipid efflux from foamy Mϕ, reduced lipid accumulation and inhibited the pro-inflammatory response of foamy Mϕ, and accelerated clearance of cell debris and necrotic cells, which resulted in functional recovery. Our study highlights the importance of understanding the pathologic role of foamy Mϕ in SCI progression and the potential of ABCA1 as a therapeutic target for modulating the inflammatory response, promoting lipid metabolism, and facilitating functional recovery in SCI.

Security Analysis for Dynamic State Estimation of Power Systems With Measurement Delays.

This article is centered on the cybersecurity research of dynamic state estimation for power systems with measurement delays. Relying on mixed measurements from phasor measurement units (PMUs) and remote terminal units (RTUs), a delayed measurement model is constructed. A modified state estimator based on the Kalman filter (KF) is designed, which can obtain the optimal estimated states under measurement delays. Moreover, the measurement data transmitted from the sensor to the estimator are vulnerable to cyberattacks. Especially, false data-injection (FDI) attacks are frequently encountered in the power system state estimation (PSSE) process. In the case of measurement delays, an FDI attack strategy is designed to interfere with the state estimator and evade detection by the chi-square detector. By utilizing the attacked estimated information and the uncorrupted measurement information, two measurement residual vectors are designed. According to these two residual vectors, a chi-square-based attack detection method is proposed, which has the ability to detect the attack without being affected by the delayed measurements. The proposed KF algorithm and attack detection method are implemented on an IEEE 14-bus system and they are confirmed to be effective and feasible.

Event-Based Adaptive NN Fixed-Time Cooperative Formation for Multiagent Systems.

This article focuses on the fixed-time formation control problem for nonlinear multiagent systems (MASs) with dynamic uncertainties and limited communication resources. Under the framework of the backstepping method, a time-varying formation function is introduced in the controller design. To attain the prescribed transient and steady-state performance of MASs, a fixed-time prescribed performance function (FTPPF) is designed and the further coordinate transformation addressing the zero equilibrium point problem is removed. To achieve better approximating performance, a neural network (NN)-based composite dynamic surface control (CDSC) strategy is proposed, where the CDSC scheme is consisted of prediction errors and serial-parallel estimation models. According to the signals generated by the estimation models, disturbance observers are established to overcome the difficulty from approximating errors and mismatched disturbances. Moreover, an improved dynamic event-triggered mechanism and varying threshold parameters are constructed to reduce the signal transmission frequency. Via the Lyapunov stability theory, all the signals in the closed-loop system are semi-globally uniformly ultimately bounded. Finally, the simulation results verify the effectiveness of the developed CDSC strategy.

Traditional Chinese medicine together with high-dose vitamin C improves the therapeutic effect of western medicine against COVID-19.

OBJECTIVES: Traditional Chinese medicine has been reported to be effective in the treatment of epidemic diseases. Here, we aimed to investigate the effects of combined therapy of Chinese and western medicine on coronavirus disease 2019 (COVID-19). METHODS: A total of 60 patients diagnosed with COVID-19 were enrolled. Both the ordinary and severely affected patients were randomly divided into Groups A-C each with 10 cases each. The patients in Group A-C received Western medicine, Western medicine + traditional Chinese medicine, and Western medicine + traditional Chinese medicine + high dose of vitamin C, respectively. The time of disease recovery, symptoms disappearance, chest CT improvement, and tongue amelioration was recorded. Leukocyte, neutrophil and lymphocyte were monitored, as well as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), procalitonin (PCT), inflammatory factors, partial pressure of oxygen and carbon dioxide (PaCO2) and oxygenation index (PaO2). Urinary tract stones, liver function, and other side-effects such as gastrointestinal dysfunction were also investigated. RESULTS: Traditional Chinese medicine enhanced the effect of Western medicine, including the reduction of CRP, ESR, PCT, and inflammatory factors, and the increase of leukocyte, neutrophil, and lymphocyte counts, and the improvement of respiratory rate, PaO2, PaCO2, and oxygenation index. Traditional Chinese medicine combined with high-dose Vitamin C therapy more effectively shortened the time of disease recovery, symptom disappearance, chest CT improvement, and tongue amelioration. CONCLUSIONS: a combined therapy of Western medicine, traditional Chinese medicine, and high dose of Vitamin C results in a most effective outcome in the treatment of COVID-19.

Extracellular vesicle-derived miR-511-3p from hypoxia preconditioned adipose mesenchymal stem cells ameliorates spinal cord injury through the TRAF6/S1P axis.

Extracellular vesicle (EV) from hypoxic adipose tissue-derived mesenchymal stem cells (AD-MSCs) play critical roles in spinal cord injury (SCI) by transferring miRNAs to target cells through fusion with the cell membrane. However, the role of miR-511-3p within the AD-MSCs -derived EV in SCI is largely unknown. Western blotting results demonstrated the secretion of EVs derived from AD-MSCs under hypoxia (Hyp-EVs) was more than those under normoxia (Nor-EVs), and miR-511-3p expression was more enriched in Hyp-EVs. PC12 cells were stimulated with lipopolysaccharide (LPS) to induce cell damage. AD-MSCs were transfected with miR-511-3p mimic or miR-511-3p inhibitor to induce EVs-miR-511-3p overexpression or silencing. Cells treated with Hyp-EVs-miR-511-3p mimic reduced LPS-induced apoptosis, alleviated inflammation and promoted proliferation, while cells treated with Hyp-EVs-miR-511-3p inhibitor aggravated LPS-induced apoptosis and inflammation, and suppressed proliferation. Luciferase reporter gene assay revealed tumor necrosis factor receptor-associated factor 6 (TRAF6) was a target downstream gene of miR-511-3p. A series of gain- and loss-of-function experiments verified that TRAF6 could antagonize the effects of Hyp-EVs-miR-511-3p on inflammation, cell apoptosis and viability. Furthermore, cells treated with CYM5541, an agonist of sphingosine-1-phosphate receptor 3 (S1PR3), reversed the inhibitory effect of Hyp-EVs-miR-511-3p mimic on S1PR3 expression, inflammation and cell apoptosis. Finally, intravenously injection of Hyp-EVs-miR-511-3p mimic into SCI model rats obviously reduced inflammation and promoted neurological function recovery. In conclusion, EVs-derived miR-511-3p from hypoxia preconditioned AD-MSCs ameliorates SCI via TRAF6/S1P/NF-κB pathway, which indicates that miR-511-3p may be a potential therapeutic target for SCI.

Myelin Debris Stimulates NG2/CSPG4 Expression in Bone Marrow-Derived Macrophages in the Injured Spinal Cord.

Although the increased expression of members of the chondroitin sulfate proteoglycan family, such as neuron-glial antigen 2 (NG2), have been well documented after an injury to the spinal cord, a complete picture as to the cellular origins and function of this NG2 expression has yet to be made. Using a spinal cord injury (SCI) mouse model, we describe that some infiltrated bone marrow-derived macrophages (BMDMΦ) are early contributors to NG2/CSPG4 expression and secretion after SCI. We demonstrate for the first time that a lesion-related form of cellular debris generated from damaged myelin sheaths can increase NG2/CSPG4 expression in BMDMΦ, which then exhibit enhanced proliferation and decreased phagocytic capacity. These results suggest that BMDMΦ may play a much more nuanced role in secondary spinal cord injury than previously thought, including acting as early contributors to the NG2 component of the glial scar.

[Expression of Semaphorin 3A after spinal cord injury].

OBJECTIVE: To investigate expression of Semaphorin 3A in rats after spinal cord injury and explore possible mechanism of inhibiting of axonal regeneration after SCI. METHODS: Forty healthy female SD rats, 8 weeks old, weighing (210.00±9.88) g, were randomly divided into control group(20 rats in group A) and model group(20 rats in group B). In control group, removal of T10 lamina and partial removal of T9 and T11 lamina were performed, and no further operation was performed on spinal cord (pseudo operation). In model group, the total T10 and partial T9, T11 partial lamina were incised and the spinal cord transection was performed to create animal models of spinal cord injury. The rats were perfused and spinal cord tissue obtained at 3, 7, 14, 28 and 42 days after surgery (4 rats in each group at each time point), respectively, and then HE staining was performed. Meanwhile, the expression of Semaphoring 3A was detected in accordance with the protocol of SP kit. RESULTS: After a simple spinal cord transection injury, hemorrhagic necrosis, localized edema, neurodegeneration, necrosis, and cyst formation occurred in the injured area, and glial scar formation occurred in glial cells. Semaphorin 3A expression levels in control group was low in the gray matter area. There was no expression of Semaphorin 3A in the injured area of spinal cord injury in model group 3 days after operation. On the 14th day, the expression of Semaphorin 3A in the injured area of spinal cord injury increased significantly and was at a high level. On the 28th day, the expression of Semaphorin 3A was moderate. On the 42th day, the positive expression of Semaphorin 3A returned to normal level. CONCLUSION: The increased expression of Semaphorin 3A after spinal cord injury may be one of the mechanisms that inhibit axonal regeneration.

Remarkable inhibition effects of afatinib alone or combining with paclitaxel in esophageal squamous cell carcinoma.

BACKGROUND AND AIM: Chemotherapy drugs do not work well in esophageal squamous cell carcinoma (ESCC), and none of the targeted drugs have been applied in clinic. This study aims to identify effective targeted drugs and related biomarkers for the treatment of ESCC. METHODS: The effect of 40 Food and Drug Administration-approved small-molecule inhibitors was first tested in five ESCC cell lines. CCK8 assays and xenografts derived from ESCC cell lines were performed to evaluate the anti-ESCC effects of inhibitors or chemotherapeutic agents in vitro and in vivo, respectively. Immunohistochemistry was utilized to analyze the p-EGFR expression in tissues. Western blot combining with gray analysis was conducted to detect the expression of interest protein. Flow cytometry and immunofluorescence assay were used to analyze apoptosis, cell cycle, and mitotic changes after drug treatment. RESULTS: Afatinib showed remarkable effects on inhibiting ESCC cells with higher expression of p-EGFR. Results from combinatorial screening in ESCC cells expressing lower phosphorylation level of EGFR showed that paclitaxel and afatinib presented a significant synergistic inhibitory effect (P < 0.001). Molecular analysis revealed that paclitaxel sensitized afatinib by activating EGFR, and afatinib in combination with paclitaxel effectively blocked MAPK pathway and induced G2/M cell arrest and apoptosis that is an indicator of mitotic catastrophe. CONCLUSIONS: Our data demonstrate that afatinib is an effective drug for patients with ESCC expressing higher phosphorylation level of EGFR. And for patients with lower p-EGFR in tumors, paclitaxel in combination with afatinib might be a promising therapeutic strategy in ESCC.

FKBP10 promotes proliferation of glioma cells via activating AKT-CREB-PCNA axis.

BACKGROUND: Although the availability of therapeutic options including temozolomide, radiotherapy and some target agents following neurosurgery, the prognosis of glioma patients remains poor. Thus, there is an urgent need to explore possible targets for clinical treatment of this disease. METHODS: Tissue microarrays and immunohistochemistry were used to detect FKBP10, Hsp47, p-AKT (Ser473), p-CREB (Ser133) and PCNA expression in glioma tissues and xenografts. CCK-8 tests, colony formation assays and xenograft model were performed to test proliferation ability of FKBP10 in glioma cells in vitro and in vivo. Quantitative reverse transcriptase-PCR, western-blotting, GST-pull down, co-immunoprecipitation and confocal-immunofluorescence staining assay were used to explore the molecular mechanism underlying the functions of overexpressed FKBP10 in glioma cells. RESULTS: FKBP10 was highly expressed in glioma tissues and its expression was positively correlates with grade, poor prognosis. FKBP10-knockdown suppressed glioma cell proliferation in vitro and subcutaneous/orthotopic xenograft tumor growth in vivo. Silencing of FKBP10 reduced p-AKT (Ser473), p-CREB (Ser133), PCNA mRNA and PCNA protein expression in glioma cells. FKBP10 interacting with Hsp47 enhanced the proliferation ability of glioma cells via AKT-CREB-PCNA cascade. In addition, correlation between these molecules were also found in xenograft tumor and glioma tissues. CONCLUSIONS: We showed for the first time that FKBP10 is overexpressed in glioma and involved in proliferation of glioma cells by interacting with Hsp47 and activating AKT-CREB-PCNA signaling pathways. Our findings suggest that inhibition of FKBP10 related signaling might offer a potential therapeutic option for glioma patients.

Olfactory ensheathing cell transplantation alters the expression of chondroitin sulfate proteoglycans and promotes axonal regeneration after spinal cord injury.

Cell transplantation is a potential treatment for spinal cord injury. Olfactory ensheathing cells (OECs) play an active role in the repair of spinal cord injury as a result of the dual characteristics of astrocytes and Schwann cells. However, the specific mechanisms of repair remain poorly understood. In the present study, a rat model of spinal cord injury was established by transection of T10. OECs were injected into the site, 1 mm from the spinal cord stump. To a certain extent, OEC transplantation restored locomotor function in the hindlimbs of rats with spinal cord injury, but had no effect on the formation or volume of glial scars. In addition, OEC transplantation reduced the immunopositivity of chondroitin sulfate proteoglycans (neural/glial antigen 2 and neurocan) and glial fibrillary acidic protein at the injury site, and increased the immunopositivity of growth-associated protein 43 and neurofilament. These findings suggest that OEC transplantation can regulate the expression of chondroitin sulfate proteoglycans in the spinal cord, inhibit scar formation caused by the excessive proliferation of glial cells, and increase the numbers of regenerated nerve fibers, thus promoting axonal regeneration after spinal cord injury. The study was approved by the Animal Ethics Committee of the Medical College of Xi'an Jiaotong University, China (approval No. 2018-2048) on September 9, 2018.

High S phase kinase-associated protein 2 expression is a potential prognostic biomarker for glioma.

S phase kinase-associated protein 2 (SKP2), a substrate recognizing protein, serves an important role in promoting cell cycle progression through ubiquitination and degradation of cell cycle inhibitors. In the present study, the clinical significance of SKP2 in gliomas was studied; 395 glioma specimens and 20 non-neoplastic tissues were collected and immunohistochemical analysis was performed. χ2 test was used to assess the associations between SKP2 expression and clinical parameters. Overall survival (OS) curves were plotted according to the Kaplan-Meier method. In the tested glioma samples, SKP2 expression was mainly observed in glioblastomas (GBMs). Survival analysis demonstrated that the overall survival time of the high SKP2 expression group was lower compared with the low SKP2 expression group (median OS, 10.04 months vs. 16.50 months; P=0.003). Moreover, SKP2 was independently associated with an unfavorable prognosis in GBMs. In addition, the expression of SKP2 was associated with the expression of phosphorylated retinoblastoma protein and the epidermal growth factor receptor. A combination of SKP2 expression along with isocitrate dehydrogenase 1 (IDH1) mutations and telomerase reverse transcriptase (TERT) promoter mutations was used to classify glioma patients for survival analysis. Patients with low SKP2 expression, IDH1 mutation and wild-type TERT promoter demonstrated the longest survival time. The findings of the present study, indicate that SKP2 is a potential prognostic biomarker in patients with GBMs.

Overexpression of IGFBP2 mRNA predicts poor survival in patients with glioblastoma.

The prognosis of patients with glioblastoma (GBM) is dismal. It has been reported that Insulin-like growth factor (IGF) binding protein 2 (IGFBP2) is associated with the mobility and invasion of tumor cells. We investigated the expression of IGFBP2 mRNA in GBMs and its clinical relevance, using tissue microarrays and RNAscope in situ hybridization in 180 GBMs and 13 normal or edematous tissues. The correlations between the expression and clinical pathological parameters as well as some other biomarkers were analyzed. Overexpression of IGFBP2 mRNA was observed in 23.9% of tumors tested. No expression of IGFBP2 mRNA was detected in normal or edematous tissues. Kaplan-Meier survival analysis showed that the survival time of all the patients with high IGFBP2 tumors had shorter survival than those with low IGFBP2 (P<0.01). Univariate regression and multivariate regression both indicated that the expression of IGFBP2 transcript level was an independent prognostic factor (P=0.008 and 0.007, respectively). Furthermore, expression of IGFBP2 mRNA was related to the occurrence of isocitrate dehydrogenase 1 (IDH1) mutation, high heat shock protein 27 (Hsp27) expression and telomerase reverse transcriptase (TERT) promoter mutation (TERTp+) (P=0.013, 0.015 and 0.016, respectively), and patients with TERTp+/IGFBP2high showed the shortest survival. In conclusion, IGFBP2 mRNA expression status is an independent prognostic biomarker in GBMs, and the combination of IGFBP2 mRNA and TERTp status might serve as a prognostic indicator in patients with GBM.

Microvascular endothelial cells engulf myelin debris and promote macrophage recruitment and fibrosis after neural injury.

The clearance of damaged myelin sheaths is critical to ensure functional recovery from neural injury. Here we show a previously unidentified role for microvessels and their lining endothelial cells in engulfing myelin debris in spinal cord injury (SCI) and experimental autoimmune encephalomyelitis (EAE). We demonstrate that IgG opsonization of myelin debris is required for its effective engulfment by endothelial cells and that the autophagy-lysosome pathway is crucial for degradation of engulfed myelin debris. We further show that endothelial cells exert critical functions beyond myelin clearance to promote progression of demyelination disorders by regulating macrophage infiltration, pathologic angiogenesis and fibrosis in both SCI and EAE. Unexpectedly, myelin debris engulfment induces endothelial-to-mesenchymal transition, a process that confers upon endothelial cells the ability to stimulate the endothelial-derived production of fibrotic components. Overall, our study demonstrates that the processing of myelin debris through the autophagy-lysosome pathway promotes inflammation and angiogenesis and may contribute to fibrotic scar formation.

Overexpression of MCM6 predicts poor survival in patients with glioma.

Minichromosome maintenance proteins (MCMs) play an essential role in DNA replication and other cellular activities. However, their expression levels and clinical value in glioma are unclear. In the present study, we analyzed the relationship between MCM mRNA expression and clinical parameters in 325 gliomas and found that MCM6 presented high expression and was associated with poor survival. Immunohistochemistry analysis of an independent data set of 423 glioma tissues confirmed the overexpression of MCM6 protein, especially in glioblastomas with shorter overall survival. Importantly, a combination of MCM6 overexpression with IDH1 mutation further improved the prediction of the prognosis of glioblastomas. Patients with IDH1 mutation and low MCM6 expression exhibited the longest survival, whereas those with high MCM6 expression and wild-type IDH1 showed the shortest. Collectively, our observation indicates that MCM6 is a novel potential biomarker for predicting poor prognosis of the patients with glioma.

Phosphorylated Hsp27 is mutually exclusive with ATRX loss and the IDH1R132H mutation and may predict better prognosis among glioblastomas without the IDH1 mutation and ATRX loss.

AIM: To identify biomarkers for accurate classification of glioma. PATIENTS AND METHODS: We evaluated the heat shock protein 27 (Hsp27), phosphorylated Hsp27 (p-Hsp27), ATRX and IDH1R132Hproteins using immunohistochemistry in 421 glioma tissues. The χ2 test was used to assess the relationship between molecular alterations and clinico-pathological parameters. Kaplan-Meier survival curves were constructed, and differences were detected by the log-rank test. RESULTS: We found that Hsp27 and p-Hsp27 were mainly expressed in aggressive astrocytic gliomas. However, neither Hsp27 nor p-Hsp27 expression was related to survival time for any grade of glioma. Interestingly, p-Hsp27 was mutually exclusive with ATRX loss (ATRX-) and the IDH1R132H mutation, except for one case of anaplastic astrocytoma. We classified glioblastomas (GBMs) into three subtypes: ATRX-/IDH1R132H, high p-Hsp27 expression (p-Hsp27+) and none of these three markers. ATRX-/IDH1R132Hshowed the longest median survival (19.6 months). The prognostic difference between p-Hsp27+ and none of these three markers was significant (15.0 vs 13.1 months, P=0.045). Moreover, p-Hsp27+ predicted better sensitivity for standard therapy among GBMs without the IDH1 mutation and ATRX loss (26.3 vs 15.5 months, P=0.008). CONCLUSION: p-Hsp27 is a novel biomarker of glioma and might have important clinical value for further classification of patients with wild-type IDH1 and normal ATRX expression, for evaluating prognosis and for guidance for adjuvant therapy.

Neural Stem Cell-Conditioned Medium Suppresses Inflammation and Promotes Spinal Cord Injury Recovery.

Spinal cord injury (SCI) causes functional impairment as a result of the initial injury followed by secondary injury mechanism. SCI provokes an inflammatory response that causes secondary tissue damage and neurodegeneration. While the use of neural stem cell (NSC) engraftment to mitigate secondary injury has been of interest to many researchers, it still faces several limitations. As such, we investigated if NSC-conditioned medium (NSC-M) possesses therapeutic potential for the treatment of SCI. It has been proposed that many of the beneficial effects attributed to stem cell therapies are due to secreted factors. Utilizing primary cell culture and murine models of SCI, we determined that systemic treatment with NSC-M was able to significantly improve motor function and lesion healing. In addition, NSC-M demonstrated significant anti-inflammatory potential in vitro and in vivo, reducing inflammatory cytokine expression in both activated macrophages and injured spinal cord tissues. NSC-M was also able to reduce the expression of inducible nitric oxide synthase (iNOS) within the spleen of injured animals, indicating an ability to reduce systemic inflammation. Thus, we believe that NSC-M offers a possible alternative to direct stem cell engraftment for the treatment of SCI.

Catalase-Laden Microdevices for Cell-Mediated Enzyme Delivery.

Enzymes have been used to treat various human diseases and traumas. However, the therapeutic utility of free enzymes is impeded by their short circulation time, lack of targeting ability, immunogenicity, and inability to cross biological barriers. Cell-mediated drug delivery approach offers the unique capability to overcome these limitations, but the traditional cell-mediated enzyme delivery techniques suffer from drawbacks such as risk of intracellular degradation of and low loading capacity for the payload enzyme. This article presents the development of a novel cell-mediated enzyme delivery technique featuring the use of micrometer-sized disk-shaped particles termed microdevices. The microdevices are fabricated by layer-by-layer assembly and soft lithography with catalase being used as a model therapeutic enzyme. The amount of catalase in the microdevices can be controlled with the number of catalase layers. Catalase in the microdevices is catalytically active, and active catalase is slowly released from the microdevices. Moreover, cell-microdevice complexes are produced by attaching the catalase-laden microdevices to the external surface of both K562 cells and mouse embryonic stem cells. This technique is potentially applicable to other enzymes and cells and promises to be clinically useful.

[Macrophages promote the migration of neural stem cells into mouse spinal cord injury site].

Objective To explore the role of macrophages in the migration of neural stem cells (NSCs) in vivo and in vitro . Methods NSCs with green fluorescent protein (GFP) were isolated from GFP transgenic mice and the immunofluorescence cytochemical staining of nestin was used to identify NSCs. After spinal cord injury was induced, the tissue level of macrophage chemotactic protein-1 (MCP-1) mRNA was detected using quantitative real time PCR. The migration of GFP-NSCs was investigated 1 week after GFP-NSCs were injected into both sides of the damaged area. The effect of macrophage on the migration of NSCs in vitro was tested by Transwell(TM) system and the content of MCP-1 was detected by ELISA. Results NSCs highly expressed nestin. Compared with the control group, the level of MCP-1 mRNA significantly increased in the spinal cord injury group. The NSCs which were injected into the spinal cord migrated into the center of the injured site where F4/80 was highly expressed. Macrophages significantly increased the number of migrating NSCs in vitro and the secretion of MCP-1. Conclusion Macrophages induce NSC migrating into the spinal cord injury site possibly through promoting the secretion of MCP-1.

Anti-Inflammatory Mechanism of Neural Stem Cell Transplantation in Spinal Cord Injury.

Neural stem cell (NSC) transplantation has been proposed to promote functional recovery after spinal cord injury. However, a detailed understanding of the mechanisms of how NSCs exert their therapeutic plasticity is lacking. We transplanted mouse NSCs into the injured spinal cord seven days after SCI, and the Basso Mouse Scale (BMS) score was performed to assess locomotor function. The anti-inflammatory effects of NSC transplantation was analyzed by immunofluorescence staining of neutrophil and macrophages and the detection of mRNA levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and interleukin-12 (IL-12). Furthermore, bone marrow-derived macrophages (BMDMs) were co-cultured with NSCs and followed by analyzing the mRNA levels of inducible nitric oxide synthase (iNOS), TNF-α, IL-1ß, IL-6 and IL-10 with quantitative real-time PCR. The production of TNF-α and IL-1ß by BMDMs was examined using the enzyme-linked immunosorbent assay (ELISA). Transplanted NSCs had significantly increased BMS scores (p < 0.05). Histological results showed that the grafted NSCs migrated from the injection site toward the injured area. NSCs transplantation significantly reduced the number of neutrophils and iNOS+/Mac-2+ cells at the epicenter of the injured area (p < 0.05). Meanwhile, mRNA levels of TNF-α, IL-1ß, IL-6 and IL-12 in the NSCs transplantation group were significantly decreased compared to the control group. Furthermore, NSCs inhibited the iNOS expression of BMDMs and the release of inflammatory factors by macrophages in vitro (p < 0.05). These results suggest that NSC transplantation could modulate SCI-induced inflammatory responses and enhance neurological function after SCI via reducing M1 macrophage activation and infiltrating neutrophils. Thus, this study provides a new insight into the mechanisms responsible for the anti-inflammatory effect of NSC transplantation after SCI.