Yanfeng Wu

Reduced immunomodulation potential of bone marrow-derived mesenchymal stem cells induced CCR4+CCR6+ Th/Treg cell subset imbalance in ankylosing spondylitis.

IntroductionAnkylosing spondylitis (AS) is a chronic autoimmune disease, and the precise pathogenesis is largely unknown at present. Bone marrow-derived mesenchymal stem cells (BMSCs) with immunosuppressive and anti-inflammatory potential and Th17/Treg cells with a reciprocal relationship regulated by BMSCs have been reported to be involved in some autoimmune disorders. Here we studied the biological and immunological characteristics of BMSCs, the frequency and phenotype of CCR4+CCR6+ Th/Treg cells and their interaction in vitro in AS.MethodsThe biological and immunomodulation characteristics of BMSCs were examined by induced multiple-differentiation and two-way mixed peripheral blood mononuclear cell (PBMC) reactions or after stimulation with phytohemagglutinin, respectively. The interactions of BMSCs and PBMCs were detected with a direct-contact co-culturing system. CCR4+CCR6+ Th/Treg cells and surface markers of BMSCs were assayed using flow cytometry.ResultsThe AS-BMSCs at active stage showed normal proliferation, cell viability, surface markers and multiple differentiation characteristics, but significantly reduced immunomodulation potential (decreased 68 ± 14%); the frequencies of Treg and Fox-P3+ cells in AS-PBMCs decreased, while CCR4+CCR6+ Th cells increased, compared with healthy donors. Moreover, the AS-BMSCs induced imbalance in the ratio of CCR4+CCR6+ Th/Treg cells by reducing Treg/PBMCs and increasing CCR4+CCR6+ Th/PBMCs, and also reduced Fox-P3+ cells when co-cultured with PBMCs. Correlation analysis showed that the immunomodulation potential of BMSCs has significant negative correlations with the ratio of CCR4+CCR6+ Th to Treg cells in peripheral blood.ConclusionsThe immunomodulation potential of BMSCs is reduced and the ratio of CCR4+CCR6+ Th/Treg cells is imbalanced in AS. The BMSCs with reduced immunomodulation potential may play a novel role in AS pathogenesis by inducing CCR4+CCR6+ Th/Treg cell imbalance.

Effects and Safety of Allogenic Mesenchymal Stem Cell Intravenous Infusion in Active Ankylosing Spondylitis Patients who Failed NSAIDs: A 20-Week Clinical Trial

Our objective was to evaluate the feasibility, safety, and efficacy of intravenous (IV) infusion of allogenic mesenchymal stem cells (MSCs) in ankylosing spondylitis (AS) patients who are refractory to or cannot tolerate the side effects of nonsteroidal anti-inflammatory drugs (NSAIDs). AS patients enrolled in this study received four IV infusions of MSCs on days 0, 7, 14, and 21. The percentage of ASAS20 responders (the primary endpoint) at the fourth week and the mean ASAS20 response duration (the secondary endpoint) were used to assess treatment response to MSC infusion and duration of the therapeutic effects. Ankylosing Spondylitis Disease Activity Score Containing C-reactive Protein (ASDAS-CRP) and other preestablished evaluation indices were also adopted to evaluate the clinical effects. Magnetic resonance imaging (MRI) was performed to detect changes of bone marrow edema in the spine. The safety of this treatment was also evaluated. Thirty-one patients were included, and the percentage of ASAS20 responders reached 77.4% at the fourth week, and the mean ASAS20 response duration was 7.1 weeks. The mean ASDAS-CRP score decreased from 3.6 ± 0.6 to 2.4 ± 0.5 at the fourth week and then increased to 3.2 ± 0.8 at the 20th week. The average total inflammation extent (TIE) detected by MRI decreased from 533,482.5 at baseline to 480,692.3 at the fourth week (p > 0.05) and 400,547.2 at the 20th week (p < 0.05). No adverse effects were noted. IV infusion of MSCs is a feasible, safe, and promising treatment for patients with AS.

Imbalance between BMP2 and Noggin induces abnormal osteogenic differentiation of mesenchymal stem cells in ankylosing spondylitis

To study the osteogenic differentiation capacity of bone marrow–derived mesenchymal stem cells (BM‐MSCs) from patients with ankylosing spondylitis (AS) and to investigate the mechanisms of abnormal osteogenic differentiation of BM‐MSCs in AS.

Epidemiology of spinal cord injuries and risk factors for complete injuries in Guangdong, China: A retrospective study

Background Spinal cord injuries are highly disabling and deadly injuries. Currently, few studies focus on non-traumatic spinal cord injuries, and there is little information regarding the risk factors for complete injuries. This study aims to describe the demographics and the injury characteristics for both traumatic and non-traumatic spinal cord injuries and to explore the risk factors for complete spinal cord injuries. Methods A retrospective study was performed by reviewing the medical records of 3,832 patients with spinal cord injuries who were first admitted to the sampled hospitals in Guangdong, China. The demographics and injury characteristics of the patients were described and compared between the different groups using the chi-square test. Logistic regression was conducted to analyze the risk factors for complete spinal cord injuries. Results The proportion of patients increased from 7.0% to 14.0% from 2003 to 2011. The male-to-female ratio was 3.0∶1. The major cause of spinal cord injuries was traffic accidents (21.7%). Many of the injured were workers (36.2%), peasants (22.8%), and unemployed people (13.9%); these occupations accounted for 72.9% of the total sample. A multivariate logistic regression model revealed that the OR (95% CI) for male gender compared to female gender was 1.25 (1.07–1.89), the OR (95%CI) for having a spinal fracture was 1.56 (1.35–2.60), the OR (95%CI) for having a thoracic injury was 1.23 (1.10–2.00), and the OR (95%CI) for having complications was 2.47 (1.96–3.13). Conclusion The proportion of males was higher than the proportion of females. Workers, peasants and the unemployed comprised the high-risk occupational categories. Male gender, having a spinal fracture, having a thoracic injury, and having complications were the major risk factors for a complete injury. We recommend that preventive measures should focus on high-risk populations, such as young males.

Imbalance Between Bone Morphogenetic Protein 2 and Noggin Induces Abnormal Osteogenic Differentiation of Mesenchymal Stem Cells in Ankylosing Spondylitis

To study the osteogenic differentiation capacity of bone marrow–derived mesenchymal stem cells (BM‐MSCs) from patients with ankylosing spondylitis (AS) and to investigate the mechanisms of abnormal osteogenic differentiation of BM‐MSCs in AS.

Rosiglitazone enhances the proliferation of neural progenitor cells and inhibits inflammation response after spinal cord injury.

It has been previously shown that peroxisome proliferators-activated receptor gamma (PPAR-γ) is beneficial for nervous system injury. In present study, we examined the effect of rosiglitazone, a PPAR-γ agonist, on spinal cord injury (SCI) in rats. SCI was induced by dropping a 10g weight rod at a height of 25mm. The animals were randomly divided into vehicle group, rosiglitazone treated group, and G3335 treated group. Locomotor function recovery was evaluated by the Basso-Beattie-Bresnahan locomotor rating scale (BBB scale), NF-κB expression and endogenous neural progenitor cells (NPCs) proliferation and differentiation was assessed by flow cytometry and immunohistochemistry. Compared with the vehicle groups, we found that the rosiglitazone could significantly ameliorate locomotor recovery, reduce NF-κB expression, and increase the proliferation of endogenous NPCs. when the PPAR-γ antagonist was use, these effects were abolished. However, neurons differentiating from endogenous NPCs were inhibited when PPAR-γ was activated. Our results suggest that the activation of PPAR-γ may be a potential alternative treatment for spinal cord injury.

Sensitivity and specificity of in vivo diffusion-weighted MRI in acute spinal cord injury

The aim of this study was to test the sensitivity and specificity of diffusion-weighted MRI for the detection of acute spinal cord injury. Forty female New Zealand white rabbits were randomly divided into four groups: the mild, moderate and severe injury groups, and the control (sham operation) group. Contusion of the spinal cord was induced using a weight-drop impactor. All animals were imaged using T1-weighted, T2-weighted, and diffusion-weighted imaging (DWI) sequences at 30 minutes, 6 hours, and 24 hours after injury. One animal from each group was killed at each time point for histologic examination of the spinal cord. DWI had a sensitivity of 100% at all time points, whereas T2-weighted MRI had a sensitivity of 43.33% at 30 minutes after injury, 81.48% at 6 hours after injury, and 95.83% at 24 hours after injury. Conversely, the specificity of DWI was lower than that of T2-weighted MRI at all time points. One animal in the control group had a non-specific high signal on DWI. Significant systematic differences were seen between DWI and T2-weighted MRI at both 30 minutes and 6 hours after injury. The apparent diffusion coefficient values of the lesion were lower than those of adjacent unaffected regions in the mild and moderate injury groups, but higher than adjacent unaffected regions in the severe injury group. The histological findings were reliably correlated with the magnetic resonance findings. We found that DWI has a higher sensitivity, but a lower specificity, than conventional MRI for the detection of early pathological changes after contusive injury.

TNF-α Induced the Enhanced Apoptosis of Mesenchymal Stem Cells in Ankylosing Spondylitis by Overexpressing TRAIL-R2

Ankylosing spondylitis (AS) is an autoimmune disease with unknown etiology. Dysregulated mesenchymal stem cells (MSCs) apoptosis may contribute to the pathogenesis of autoimmune diseases. However, apoptosis of MSCs from patients with AS (ASMSCs) has not been investigated yet. The present study aims to assess the apoptosis of bone marrow-derived ASMSCs and to investigate the underlying mechanisms of altered ASMSCs apoptosis. We successfully induced the apoptosis of ASMSCs and MSCs from healthy donors (HDMSCs) using the combination of tumor necrosis factor alpha (TNF-α) and cycloheximide (CHX). We found that ASMSCs treated with TNF-α and CHX showed higher apoptosis levels compared to HDMSCs. During apoptosis, ASMSCs expressed significantly more TRAIL-R2, which activated both the death receptor pathway and mitochondria pathway by increasing the expression of FADD, cleaved caspase-8, cytosolic cytochrome C, and cleaved caspase-3. Inhibiting TRAIL-R2 expression using shRNA eliminated the apoptosis differences between HDMSCs and ASMSCs by partially reducing ASMSCs apoptosis but minimally affecting that of HDMSCs. Furthermore, the expression of FADD, cleaved caspase-8, cytosolic cytochrome C, and cleaved caspase-3 were comparable between HDMSCs and ASMSCs after TRAIL-R2 inhibition. These results indicated that increased TRAIL-R2 expression results in enhanced ASMSCs apoptosis and may contribute to AS pathogenesis.

Analysis of methylprednisolone-induced inhibition on the proliferation of neural progenitor cells in vitro by gene expression profiling.

Recently, it has been proved that methylprednisolone has inhibition effect on the proliferation of endogenous neural progenitor cells (NPCs) after spinal cord injury (SCI). Similar effect has also been found on NPCs cultured in vitro. However, the mechanism remains to be fully delineated. The purpose of this study is to investigate the potential molecular mechanism of this effect in NPCs cultured in vitro by gene expression profiling. Fetal mouse brain-derived NPCs were divided into 2 groups: NPCs incubated with methylprednisolone as a model of the methylprednisolone treatment after SCI, and without methylprednisolone as the control group. After the cell quantitative analysis and CCK-8 assay, the microarray analysis was carried out. Genes differentially expressed between NPCs treated with and without methylprednisolone were extracted. It was observed that the expression of 143 genes, including many members of distinct families, such as hypoxia inducible factors and neurotransmitter receptors, were significantly changed in response to the methylprednisolone treatment. Our results provide global molecular insights into the mechanisms of methylprednisolone-induced proliferation inhibition effect and suggest that EdnrB may play an important role in this effect.

Differential Expression Profiles of Long Noncoding RNA and mRNA of Osteogenically Differentiated Mesenchymal Stem Cells in Ankylosing Spondylitis.

Objective. We previously demonstrated that mesenchymal stem cells (MSC) from patients with ankylosing spondylitis (AS; ASMSC) have a greater osteogenic differentiation capacity than MSC from healthy donors (HDMSC) and that this difference underlies the pathogenesis of pathological osteogenesis in AS. Here we compared expression levels of long noncoding RNA (lncRNA) and mRNA between osteogenically differentiated ASMSC and HDMSC and explored the precise mechanism underlying abnormal osteogenic differentiation in ASMSC. Methods. HDMSC and ASMSC were induced with osteogenic differentiation medium for 10 days. Microarray analyses were then performed to identify lncRNA and mRNA differentially expressed between HDMSC and ASMSC, which were then subjected to bioinformatics analysis and confirmed by quantitative real-time PCR (qRT-PCR) assays. In addition, coding-non-coding gene co-expression (CNC) networks were constructed to examine the relationships between the lncRNA and mRNA expression patterns. Results. A total of 520 lncRNA and 665 mRNA were differentially expressed in osteogenically differentiated ASMSC compared with HDMSC. Bioinformatics analysis revealed 64 signaling pathways with significant differences, including transforming growth factor-β signaling. qRT-PCR assays confirmed the reliability of the microarray data. The CNC network indicated that 4 differentially expressed lncRNA, including lnc-ZNF354A-1, lnc-LIN54-1, lnc-FRG2C-3, and lnc-USP50-2 may be involved in the abnormal osteogenic differentiation of ASMSC. Conclusion. Our study characterized the differential lncRNA and mRNA expression profiles of osteogenically differentiated ASMSC and identified 4 lncRNA that may participate in the abnormal osteogenic differentiation of ASMSC. These results provide insight into the pathogenesis of pathological osteogenesis in AS.