After the tissue injuries appear,bone marrow mesenohymal stem cells(MSCs)migrate to the lesion place against the chemokine concentration gradient and produce natural compensatory repair by differentiation of the injured cells,immunological regulation and paracrine of various cytokines,such as hepatocyte growth factor(HGF).HGF is one of the important chemokine factors of MSCs.It can inhibit proliferation of MSCs and induce MSCs into hepatocytes and epithelial cells.However,the mechanisms of MSCs on the injured tissue repairing are complicated,and the underlying mechanism consists of homing to the injured lesion,correct oriented differentiation of local micrcenvironment and in inhibition on the host immunity.With the deeperresearch,the mechanism of reparative process MSCs acting on damaged tissue will be elucidated gradually.It may be helpful for the instruction of the clinical treatment to engraft MSCs which are modified with effective genes and to enhance the ability of ceil engraftment.

BACKGROUND:Many in vivo and in vitro experiments indicate that hypoxic co-cultures promote stem cells differentiate into chondrocytes.
OBJECTIVE:To evaluate the influence of hypoxia on the chondrogenic differentiation of three-dimensional co-cultured adipose-derived stem cells and articular chondrocytes.
METHODS:Adipose-derived stem cells and articular chondrocytes were mixed at the ratio of 3:1, then the mixed cells were seeded onto poly(lactic-co-glycolic acid)-gelatin scaffold at the ultimate concentration of 5.0×1010/L. The cells were cultured in normoxia (20%O 2 ) and hypoxic (5%O 2 ) conditions for 6 weeks. After culture, hematoxylin and eosin staining was performed for histological structure analysis, and alcian blue staining was used to evaluate glycosaminoglycan synthesis. Type II col agen expression was detected by immunohistochemistry staining. The content of DNA, glycosaminoglycan and hydroxyproline in the scaffold-cellcomplex was measured.
RESULTS AND CONCLUSION:In the hypoxia group, hematoxylin-eosin staining showed the formation of massive cells and extracellular matrix;alcian blue staining showed massive glycosaminoglycan formation;immunohistochemistry staining detected strongly positive expression of col agen type II, the content of DNA, glycosaminoglycan and hydroxyproline was higher than the normoxia group. Hypoxia promotes in vitro chondrogenic differentiation of co-cultured adipose-derived stem cells and articular chondrocytes. .

[ABSTRACT]AIM:TostudytheeffectofsmallinterferingRNA(siRNA)ontheexpressionofbeta2-microglo-bulin (β2M) in pre-differentiated bone marrow mesenchymal stem cells (BMSCs).METHODS: The β2M siRNA was transfected into the pre-differentiated BMSCs with Lipofectamine 2000.BMSCs were divided into transfection group , blank control group and negative control group .The expression of β2 M at mRNA and protein levels was determined by real-time qPCR, Western blotting and laser confocal microscopy .The productions of aggrecan and type II collagen in pre-differentia-ted BMSCs were determined by toluidine blue staining and type Ⅱcollagen immunofluorescence .RESULTS:The results of real-time qPCR, Western blotting and laser confocal microscopy showed that siRNA successfully inhibited the expression ofβ2 M at mRNA and protein levels in the pre-differentiated BMSCs .The results of toluidine blue and type Ⅱcollagen im-munofluorescence staining showed that siRNA does not affect the productions of aggrecan and type Ⅱ collagen in the pre-differentiated BMSCs .CONCLUSION:siRNA targeting β2 M reduces the expression of β2 M in the pre-differentiated BM-SCs and does not affect the chondrocyte characteristics of pre -differentiated BMSCs .

[ABSTRACT]AIM:Toinvestigatetheinhibitoryeffectsofresveratrolonchondrosarcomaandtherelationwith mitochondrial and PI3K/Akt pathways.METHODS:Chondrosarcoma SW1353 cells were treated with resveratrol at con-centrations of 25, 50 and 100 μmol/L for the time intervals of 24 h, 48 h and 72 h.The viability and apoptosis of the SW1353 cells in the presence or absence of resveratrol were analyzed by CCK 8 assay and Hoechst 33258 staining , respec-tively.The protein levels of Bcl-2, Bax, activated caspase-3, Akt and p-Akt were detected by Western blotting .The cell migration ability was determined by wound scratch assay .RESULTS:Exposure of the cells to resveratrol resulted in a de-crease in the cell viability in a dose-and time-dependent manner (P<0.05).visible nuclei with apoptotic characteristics in resveratrol group were observed .The protein levels of activated caspase-3 and Bax were increased , and Bcl-2 and p-Akt were decreased compared with control group .The total Akt were not significantly changed .Resveratrol also significantly re-duced the migration of tumor cells .CONCLUSION:Resveratrol induces apoptosis of chondrosarcoma , which plays a role of part through mitochondrial and PI 3K/Akt signaling pathways .

AIM:To investigate the effect of oleuropein on interleukin-1β( IL-1β)-induced SD rat articular chondrocytes .METHODS:The SD rat articular chondrocytes were isolated by 2 step enzyme digestions .The chondrocytes were cultured in vitro.Inverted microscopic observation was performed during the culture .Alcian blue staining and type II collagen immunohistochemical staining were used to identify the chondrocytes .The effects of oleuropein on the viability of chondrocytes were determined by CCK-8 assay.The cells in 3rd passage were pretreated with oleuropein at 10, 50 or 100 μmol/L and subsequently stimulated with IL-1βat 10 μg/L for 24 h.Production of prostaglandin E 2 ( PGE2 ) and ni-tric oxide (NO) were evaluated by the Griess reaction and an enzyme linked immunosorbent assay (ELISA).The mRNA expression of matrix metalloproteinase ( MMP)-1 and MMP-13 was measured by real-time PCR.The protein levels of in-ducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and nuclear factor-kappa B (NF-κB) were detected by Western blotting .RESULTS:The cell viability of chondrocytes was not significantly impaired by treating with oleuropein at concentration of 10, 50 or 100μmol/L for 24 h compared with control group .Pretreatment with oleuropein significantly in-hibited the production of PGE 2 and NO induced by IL-1β.Oleuropein also significantly decreased the IL-1β-stimulated MMP-1 and MMP-13 mRNA expression in articular chondrocytes .Pretreatment with oleuropein inhibited the IL-1β-media-ted activation of NF-κB by suppressing the degradation of its inhibitory protein IκBαin the cytoplasm .CONCLUSION:Oleuropein inhibits IL-1β-induced inflammatory gene expression by suppressing NF-κB activation at the transcriptional le-vel, suggesting a new mechanism for the anti-inflammatory effects of oleuropein as a novel agent on treating with osteoarthri-tis.

Objective To analyze and evaluate the effects of the tissue engineering bladder reconstruction on the upper urinary tract structure and function.Methods The 8 male beagles were randomly divided into the two groups:sham-operation group (group A,n=4)and the collagen scaffold repair group (group B,n=4).The bladder defect animal model was established in the group B by using the collagen scaffold materials to repair the bladder.The renal function related biochemical indicators were detec-ted and the renal Doppler ultrasonic examination was performed in each group before repair and in 23 weeks after repair.The speci-mens from the two groups were performed the gross morphology observation and the histology examination on postoperative 24 weeks.Results The renal Doppler ultrasound examination showed the normal kidney morphology and normal blood flow signal.In the general observation,no calculi and neoplasm were found in the kidney and ureter of the experimental dogs.The renal function related biochemical indicators had no statistically significant differences between the two groups(P>0.05).The histological exami-nation indicated that the organization structure was integrity,the nephrons in each group had no obvious pathological changes.Con-clusion Using the collagen scaffold materials to reconstruct the canine bladder has no adverse influence on the upper urinary tract structure and function,this tissue engineering approach has good feasibility.

Objective:To investigate the clinical value of ankle-brachial index (ABI) in evaluating vascular cognitive dysfunction (VCI) in the elderly.Methods:According to the mini mental state examination (MMSE) and Montreal cognitive assessment (MoCA), 200 elderly inpatients from May 2016 to February 2018 in our hospital were selected. MoCA scale was used to evaluate the cognitive function of the patients. The patients were divided into cognitive dysfunction group ( n=110) and cognitive normal group ( n=90). The clinical data of the two groups were analyzed and compared. The correlation between ABI and MMSE, MOCA and clinical indicators was observed. The receiver operating characteristic (ROC) curve of ABI value to the predictive value of VCI in the elderly was drawn. Results:⑴ There was no significant difference between the two groups in terms of gender, the first fasting blood glucose value in hospital and the situation of diabetes, hypertension and hyperlipidemia ( P>0.05); there was significant difference in age, low-density lipoprotein cholesterol (LDL-C) level, history of small cerebral vessels and ABI between the two groups ( P<0.05). ⑵ Logistic regression analysis showed that ABI was the related factor of VCI in the elderly ( P<0.01). ⑶ Pearson correlation analysis showed that MMSE score was positively correlated with ABI ( r=0.887, P<0.01), MOCA score was positively correlated with ABI ( r=0.843, P<0.01). ⑷ The area under ROC curve of ABI prediction value for VCI in the elderly was (0.965±0.01) [95% CI (0.945, 0.985), P<0.01]. When ABI ≤0.9, the sensitivity and specificity were 88.2%, 91.1% respectively; the accuracy and the yordan index were 89.5% and 0.793. Conclusions:⑴ ABI is an influencing factor of VCI in the elderly and is positively correlated with the severity of cognitive impairment in patients. ⑵ ABI has a high predictive value for VCI of the elderly, and ABI≤0.9 can be used as an early warning factor for VCI of the elderly.

Using the E. coli, we fabricated the gene reconstructed brain derived neurotrophic factor with a fibrin binding domain (FBD-BDNF). We then tested the neurotrophic bioactivity and fibrin-binding ability of the FBD-BDNF. The E. coli was used to express the recombinant protein. The inclusion body was purified with column chromatography and renaturated to construct the right 3D formation. In this study, we successfully fabricated the FBD-BDNF and tested the binding ability and neurotrophic activity. The results demonstrated that FBD-BDNF had special binding ability of fibrin and significant neurotrophic activity for DRG cells. FBD-BDNF could have a promising application prospect in nerve tissue engineering.
Brain-Derived Neurotrophic Factor ; biosynthesis ; genetics ; Escherichia coli ; genetics ; metabolism ; Fibrin ; metabolism ; Genetic Vectors ; genetics ; Humans ; Protein Binding ; Recombinant Fusion Proteins ; biosynthesis ; genetics

OBJECTIVE: To explore the correlation between endothelial microparticles(EMPs) and subacute 1,2-dichloroethane(1,2-DCE) toxic encephalopathy. METHODS: A total of 24 patients with subacute 1,2-DCE toxic encephalopathy were selected as the case group, and 24 healthy individuals were selected as the control group using a convenient sampling method. Blood plasma was collected from the fasting venous blood of patients in these two groups, and the level of EMPs in the plasma was detected by flow cytometry. RESULTS: The levels of plasma EMPs of patients in the control group and the case group were(692.0±174.4) ×10~3/L and(839.8±155.8) ×10~3/L respectively. The levels of plasma EMPs in patients with mild, moderate and severe case subgroups were(691.6±101.9) ×10~3/L,(900.6±46.6) ×10~3/L and(1 026.8±69.8)×10~3/L respectively. The EMPs level of patients in the case group was higher than that of the control group(P<0.01). The level of EMPs in the moderate and severe case subgroups was higher than that of the control group and mild case subgroup(P<0.01). CONCLUSION: Endothelial injury was found in patients with subacute 1,2-DCE toxic encephalopathy and endothelial injury is related to the severity of poisoning.

Animals ; Cellular Reprogramming ; Collagen ; chemistry ; Induced Pluripotent Stem Cells ; cytology ; metabolism ; Mice ; Tissue Scaffolds ; chemistry