DC-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) is specific receptor on Dendritic cells, and plays a pivotal role on antigens presentation. Uptodate, the clear regulation mechanisms for DC-SIGN expression are not available.IL-4 is one of the most important cytokines inducing DC-SIGN production, while, NF-κB is an important transcription factor controlling signaling transduction. Both IL-4 and NF-κB are closely related to DC-SIGN regulation. NF-κB and IL-4 actions on DC-SIGN promoter activity, DC-SIGN expression as well as interactions between IL-4 and NF-κB were investigated in THP-1 cell. It was found that the mutation of NF-κB binding site in DC-SIGN promoter results in DC-SIGN promoter activity decrease about 50%.NF-κBp50 stimulates DC-SIGN expression in THP-1 cells. IL-4 upregulates DC-SIGN expression on THP-1 cells as well as NF-κB production. These data reveal that NF-κB is associated with IL-4 induced DC-SIGN expression.

Objective Preparing platelet rich gel through two-times centrifugal technique and co-culturing chondrocytes with PRG, then observing the proliferation and gene expression of chondrocytes, in order to provide a favorable way to prepare tissue engineering cartilage. Methods Centrifugating venous blood of rabbit through two-times centrifugal technique to obtain platelet rich plasma( PRP) ,then detecting the concentration of various growth factor in PRP. Admixing PRP with chondrocytes of rabbit and activating them with activator. After co-culti-vation,the proliferation of chondrocytes through MTT method and expression of ACAN,CollagenⅡand SOX-9 through realtime-PCR were ob-served,and compared with common cultured chondrocytes. Results The concentrations of PDGF-AB,TGF-β1,IGF-1 and VEGF in PRG were significantly higher than those in blood(P<0. 05). After co-cultivation, the proliferation rate of chondrocytes and the expression of ACAN,Collagen Ⅱ and SOX-9 were significantly higher than that of common cultured chondrocytes(P<0. 05). Conclusion Co-culturing chondrocytes with PRG is able to promote the proliferation and gene expression of chondrocytes. We considered that it is a excellent method to construct tissue engineering cartilage.

ObjectiveTo investigate the in vivo biological performance of 5 porous bioceramic scaffolds,which were bioglass,β-tricalcium phosphate (β-TCP),hydroxyapatite (HA),β-calcium silicate (β-CS) and α-CS,implanted in rabbit dorsal muscle.MethodsThe 5 porous bioceramic scaffolds were fabricated by adding pore-forming materials and sintering,and then were investigated by X-ray diffraction,porosity mensuration and biomechanics test.The scaffolds were implanted into rabbit dorsal muscle for 4,8,12,16 weeks,respectively.The samples were analyzed by X-ray,Micro-CT,histological analysis,scanning electron microscope (SEM) and energy dispersive spectrometer (EDS).The expression of bone morphogenetic protein(BMP-2) and BMP-7 in the muscle in touch with bioceramic scaffolds were also investigated by polymerase chain reaction(PCR).ResultsThe characteristic analysis of 5 scaffolds showed that the sequence of compressive strength was bioglass＞α-CS＞β-CS＞β-TCP＞HA,the sequence of elasticity modulus was α-CS＜β-TCP＜HA＜β-CS＜bioglass.It was confirmed by X-ray,Micro-CT and histological analysis that the sequence of biodegradability was β-CS＞α-CS＞β-TCP＞bioglass＞HA.The histological observation showed no new bone formation in five scaffolds.A Ca-P layer was formed in the surface of bioglass,α-CS and β-CS,which suggested their in vivo bioactivity.After 16 weeks,the expression of BMP-2 and BMP-7 was found only in β-CS.Conclusion The porous calcium silicate scaffold,which was promising for bone tissue engineering,was with good in vivo bioactivity and biodegradability,without in vivo osteoinductivity.

Objective To establish the anti-infective tissue engineered bones (TEBs) and evaluate the anti-infective and osteogenic effects of the infection-prevention TEBs on femoral large bone defects in goats.Methods Based on the controlledrelease antibiotic system fibrin gel-coated vancomycin alginate beads (FG-Vanco-AB),the infection-prevention TEBs were established and evaluated.They were transplanted into the critical-size defects in the right femurs of goats.TEBs without the controlled-release antibiotic system were used as controls and transplanted into the left femoral defects.The breakpoint sensitivity of vancomycin (5 mg/mL) for S.aureus was used as a standard concentration.Postoperatively,the vancomycin concentrations in the lesion site,in the adjacent site and in the circulation,as well as the anti-infective effects of the infection-prevention TEBs were evaluated by High-performance liquid chromatography (HPLC).Bone hcaling was assessed by histology,CT and ECT.The results were used to evaluate the osteogenic effect of the infection-prevention TEBs.Results Results from ESM,CLSM and in vivo tracing showed that the in vitro and in vivo survival conditions of seeded cells were analogous to those of TEBs.The effective concentration (over the bactericidal concentration) of vancomycin in bilateral defects and in blood lasted for 28 days,2 days and 7 days,respectively.The concentration of vancomycin in the femur decreased gradually from the grafted site to both ends.At 28 and 56 days postoperatively,the ECT results showed no significant difference between the right and left femurs.CT and histology demonstrated that at 14,28 and 112 days after surgery,bone defects in the bilateral femurs were repaired synchronously,and were completely covered by new bone tissue after 112 days.Conclusion The anti-infective TEBs were successfully established.FG-Vanco -AB in the transplanted sites provided the local bone tissues with anti-infective capability whilst not interfered the process of bone reconstnction and wound healing.

Interactions between brain-resident and peripheral infiltrated immune cells are thought to contribute to neuroplasticity after cerebral ischemia. However, conventional bulk sequencing makes it challenging to depict this complex immune network. Using single-cell RNA sequencing, we mapped compositional and transcriptional features of peri-infarct immune cells. Microglia were the predominant cell type in the peri-infarct region, displaying a more diverse activation pattern than the typical pro- and anti-inflammatory state, with axon tract-associated microglia (ATMs) being associated with neuronal regeneration. Trajectory inference suggested that infiltrated monocyte-derived macrophages (MDMs) exhibited a gradual fate trajectory transition to activated MDMs. Inter-cellular crosstalk between MDMs and microglia orchestrated anti-inflammatory and repair-promoting microglia phenotypes and promoted post-stroke neurogenesis, with SOX2 and related Akt/CREB signaling as the underlying mechanisms. This description of the brain's immune landscape and its relationship with neurogenesis provides new insight into promoting neural repair by regulating neuroinflammatory responses.
Humans ; Ischemic Stroke ; Brain/metabolism* ; Macrophages ; Brain Ischemia/metabolism* ; Microglia/metabolism* ; Gene Expression Profiling ; Anti-Inflammatory Agents ; Neuronal Plasticity/physiology* ; Infarction/metabolism*