Background Studies showed that some members of matrix metalloproteinases (MMPs) play an important role in the pathogenesis of diabetic retinopathy (DR).However,whether MMPs inhibitor can deter blood retinal barrier (BRB) from damage is below understood.Objective This study was to investigate the effects of GM6001,a MMPs inhibitor,on BRB permeability.Methods Twenty-four adult clean SD rats were randomized to the control group,diabetic group and diabetes+GM6001 group according to randomized number table.Diabetic models were induced by the intraperitoneal injection of streptozotocin in the rats of the diabetic group and the diabetes + GM6001 group,and equal volume of citrate buffer was used in the same way in the rats of the control group.GM6001 10 μ1 (100 μ mol/L) was intravitreously injected in the third and fourteenth day after modeling in the diabetes+ GM6001 group,and equal volume of normal saline solution was injected in the same way in the control group and the diabetic group.The rats were sacrificed and eyeballs were extracted 1 month after injection,and the relative expressions of MMP-2 mRNA and MMP-9 mRNA in rat retinas were detected by reverse transcription PCR (RT-PCR).Evens blue (EB) was infused via the right jugular vein,and paraformaldehyde solution 1％ was then infused via left ventricle at the perfusion pressure 120 mmHg.The eyeballs were extracted 2 minutes later,and the leakage of EB in rat retinas was examined.Results RT-PCR electrophoresis exhibited the response bands of MMP-2 mRNA,and MMP-9 mRNA and GAPDH,with the gene size of 436,536 and 484 bp,respectively.The difference of the MMP2 mRNA and MMP-9 mRNA was statisticaly significant (F =20.336,P =0.000 ; F =8.742,P =0.002) ; and the relative expressions of MMP-2 mRNA and MMP-9 mRNA were significantly higher in the diabetic group and diabetes +GM6001 group than those in the control group (all at P＜0.01),and the relative expressions of MMP-2 mRNA and MMP-9 mRNA in the diabetes+GM6001 group was significantly reduced in comparison with the diabetic group(both P=0.01,P=0.02).The standardized EB content in the retinas of the control group,diabetic group and diabetes+ GM6001 group was (12.60±3.50) ng/mg,(26.52±7.14) ng/mg and (17.55±2.65) ng/mg,showing a significant difference (F=17.032,P＜0.01),and EB content in rat retinas in the diabetic group was higher than that in the control group (P=0.003),and that in the diabetes+GM6001 group was lower in comparison with the diabetic group (P=0.020).Conclusions Intravitreal injection of GM6001 can down-regulate the expression of MMP-2 mRNA and MMP-9 mRNA in diabetic rats and therefore protect BRB.

Objective:To compare acetyltransferase MORF level in periodontal ligament stem cells( PDLSCs) derived from healthy individuals ( H-PDLSCs) with those derived from the individuals with periodontitis ( P-PDLSCs ) . And to determine the effect of MORF on the osteogenic differentiation potential of PDLSCs. Methods: Human H-PDLSCs and P-PDLSCs were cultured and cloned with limited dilution method. H-PDLSCs were stimulated by LPS, TNF-α, IL-β and the mix of the 3 inflammatory factors to imitate inflammatory environment ( IP-PDLSCs ) . Quantitative RT-PCR and Western Blot were applied to examine different expression of MORF in H-PDLSCs and P-PDLSCs. Western Blot was applied to detect expression of MORF in IP-PDLSCs. Quantitative RT-PCR, Western Blot and alizarin red staining were applied to determine osteogenic differentiation potential of H-PDLSCs with MORF knock-down. Results:Quantitative RT-PCR and Western Blot showed lower expression of MORF in P-PDLSCs compared with H-PDLSCs( P<0. 05). Western Blot revealed lower expression of MORF in IP-PDLSCs. Quantitative RT-PCR, Western Blot and alizarin red stai-ning indicated osteogenic differentiation potential was inhibited in H-PDLSCs with MORF knockdown(P<0. 05). Conclusion: Peri-odontitis can suppress the expression of MORF in PDLSCs and inhibite the osteogenic differentiation potential of PDLSCs.

Objective: To compare the osteogenic differentiation abilities of human bone marrow mesenchymal stem cells (hBMSCs) from different sources, and to provide basis for choosing a new source of seed cells in bone tissue engineering. Methods: Jaw bone-marrow-derived mesenchymal stem cells (JMMSCs) were isolated from orthognathic surgical sites and cultured by limited dilution for single cell clone. Long bone-marrow-derived mesenchymal stem cells (BMMSCs) were obtained from bone marrow of volunteers and isolated by density gradient centrifugation method. Flow cytometry was used to detect the surface markers of both cells. Osteogenic ability was assessed by PCR and Western Blot after osteogenic differentiation for the following molecules: Runx2, COL-1 and OCN. Alizarin red staining was used for determining the ability of cell mineralization after osteogenic differentiation. Results : The expressions of cell surface markers CD90 and CD105 were positive in both type of cells, while CD34, CD14 and CD45 were all negative. After 21 days of osteogenic induction, JMMSCs formed significantly more mineralized nodules than BMMSCs. After 7, 14, 21 days of osteogenic induction, JMMSCs expressed more osteogenic-related molecules than BMMSCs. Conclusion The osteogenic differentiation capacity and mineralization ability of JMMSCs are significantly higher than BMMSCs. Jaw bone might be a more suitable source of seed cells in bone tissue engineering compared with long bone.

OBJECTIVE: This study aims to investigate the mechanism of K (lysine) acetyltransferase 2A (KAT2A) regulation and control on the osteogenic differentiation of periodontal ligament stem cells (PDLSCs). METHODS: The expression levels of KAT2A in PDLSCs were compared from each generation of the normal (H-PDLSCs) and periodontitis tissues (P-PDLSCs). The influences of KAT2A gene interference on the osteogenic differentiation of PDLSCs were also detected. In addition, the influences of the KAT2A gene interference to the canonical Wnt pathway and ligands were detected. The upstream and down-stream relationships between KAT2A and canonical Wnt pathway were also determined. RESULTS: The decreased expression of KAT2A in PDLSCs from the inflammatory tissue in each generation was compared with that in PDLSCs from the healthy tissue, and the difference was statistically significant (P<0.05). When the KAT2A gene was disrupted, the osteogenesis ability of PDLSC was declined, and the difference was statistically significant (P<0.05). The canonical Wnt pathway was activated, and the antagonist Dickkopf-1 (DKK-1) was reduced. After the DKK-1 addition, the osteogenic differentiation of the disturbed PDLSCs was recovered, and KAT2A was unaffected. CONCLUSIONS The KAT2A expression in PDLSCs was decreased because of perio-dontitis. The classical Wnt pathway was activated to inhibit the osteogenic differentiation of the cells.
Acetyltransferases ; Cell Differentiation ; Cells, Cultured ; Histone Acetyltransferases ; metabolism ; Humans ; Lysine ; Osteogenesis ; Periodontal Ligament ; metabolism ; Periodontitis ; metabolism ; Stem Cells ; Wnt Signaling Pathway