ObjectiveTo investigate the effect of cytoskeleton modification on the adipogenic differentiation of rat Achilles-derived tendon stem cells (TSCs) in vitro. MethodsTSCs were isolated from the tendon tissue of male Sprague Dawley rats (aged 3 weeks) by enzymatic digestion method and cultured for 3 passages. After the 3rd passage cells were cultured with DMEM medium containing 15% fetal bovine serum and cytochalasin D (CYD) at the concentrations of 0, 50, 100, 500, and 1 000 ng/mL, the cell survival condition and morphology changes were observed by inverted phase contrast microscope, the cytoskeleton was observed through fibrous actin (F-actin) staining, and the ratio of F-actin/soluble globular actin (G-actin) was detected and calculated through Western blot. According to the above results, the effective concentration of CYD was selected and used for next experiments. After TSCs were cultured for 3 and 7 days respectively with adipogenic induction media (induction group), adipogenic induction media containing CYD (CYD+induction group), ordinary medium (ordinary group), and ordinary medium containing CYD (CYD+ordinary group), the real-time quantitative PCR (qRT-PCR) and Western blot were carried out to measure the mRNA and protein expressions of adipogenic differentiation-related markers, including peroxisome proliferator-activated receptor γ (PPARγ), 1ipoprotein lipase (LPL), and fatty acid binding protein (aP2). ResultsThe final CYD concentration of 100 ng/mL can inhibit effectively G-actin polymerization into F-actin, but could not affect TSCs survival, which was used for next experiments. qRT-PCR and Western blot suggested that the mRNA expressions of PPARγ, LPL, and aP2 and the protein expressions of PPARγ and aP2 were increased significantly in the CYD+induction group at 3 and 7 days when compared with the induction group (P<0.05). In the CYD+ordinary group, there still was a significant increase in the mRNA expressions of PPARγ, LPL, and aP2 when compared with the ordinary group (P<0.05). ConclusionInhibition of F-actin polymerization can increase adipogenic differentiation of rat Achilles-derived TSCs in vitro, and cytoskeleton modification is a pre-requisite for TSCs differentiation into adipocytes, which might have important implications for the mechanism research of tendinopathy.
ObjectiveTo evaluate the effect of leucocyte- and platelet-rich plasma (L-PRP) on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in treating avascular necrosis of the femoral head (ANFH) in rabbits. MethodsTwenty-four New Zealand white rabbits (4-6 months old, both genders, weighing 2.0-3.0 kg) were used for the establishment of bilateral ANFH models and divided into 4 groups (n=6). BMSCs were isolated from the bone marrow of iliac crest, cultured and identified. L-PRP was prepared by Landesberg method. Core decompression only (group A), core decompression and L-PRP implantation (group B), core decompression and BMSCs implantation (group C), and core decompression and implantation of BMSCs and L-PRP were performed in 4 groups. To evaluate bone formation and remodeling of the defects, X-ray photography was taken at 2, 4, and 8 weeks postoperatively. The modified Lane-Sandhu scoring system was used to evaluate the bone formation. Two rabbits were sacrificed at 2, 4, 8 weeks after operation to harvest the specimens for histological observation, new blood vessel count and new bone area ratio. ResultsThe observations of radiology and histology displayed different degrees of bone regeneration at bone defect sites in each group. At 2, 4, and 8 weeks postoperatively, the results of Lane-Sandhu X-ray photography scoring, new blood vessel count, and new bone area ratio showed that groups C and D were significantly better than groups A and B, group D was significantly better than group C. and group B was significantly better than group A (P<0.05). ConclusionThese findings demonstrate that L-PRP can promote osteogenic differentiation of BMSCs in treating ANFH in rabbits, and core decompression associated with BMSCs and L-PRP is an effective and feasible method to treat ANFH.
ObjectiveTo explore the effect of fetal bovine serum (FBS) of different concentrations in the culture medium on osteogenic growth peptide (OGP) promoting bone marrow mesenchymal stem cells (BMSCs) proliferation and differentiation. MethodsBMSCs were separated from limb bones of 8 Sprague Dawley rats (5 weeks old) and purified by adherence method, and BMSCs at passage 3 were divided into 4 groups according to OGP concentration: OGP 1×10-10 mol/L group, OGP 1×10-9mol/L group, OGP 1×10-8 mol/L group, and control group without OGP; and 0, 2%, 5%, 8%, and 10%FBS concentration gradient was used in each group. The cell proliferation rate was detected by MTT method at 1, 3, 5, 7, 9, and 12 days after culture, and the activity of intracellular alkaline phosphatase (ALP) was determined by the method of p-nitrophenyl phosphate disodium at 9 days after culture. ResultsBMSCs showed adherent growth, rapid proliferation, long fiber vortex, and typical morphology. MTT analysis showed that cells could not sustain proliferation when FBS concentration was less than 5% in each group; when FBS concentration was above 8%, cells proliferated continually. Proliferation promoting effect of OGP 1×10-8 mol/L and 1×10-9 mol/L groups was significantly higher than that of the control group in all serum concentrations (P<0.05); when FBS concentration was lower than 10%, the proliferation promoting effect of OGP 1×10-8 mol/L group was significantly higher than that of the other 2 OGP groups (P<0.05), but when FBS concentration was 10%, OGP 1×10-8 mol/L group had no advantage of promoting proliferation. ALP test results showed that as the FBS concentration increased, ALP activity of all groups also significantly increased (P<0.05). Under the condition of 5%FBS and 8%FBS, the ALP activity of each OGP group was significantly greater than that of the control group, and it was the highest in OGP 1×10-8 mol/L group (P<0.05). Under the condition of 10%FBS, the ALP activity of each OGP group was still greater than that of the control group (P<0.05), but no significant difference was found between the OGP 1×10-8 mol/L group and OGP 1×10-9 mol/L group (P>0.05). ConclusionThe concentration of 8%FBS is the best concentration of serum for OGP promoting the proliferation and differentiation of BMSCs, and the most suitable concentration of promoting the proliferation and differentiation of BMSCs is OGP 1×10-8 mol/L.
Objective To summarize the role of N-myc downstream regulated gene 1 (NDRG1) and the advancement of it in tumor research. Methods Publications on line at home and abroad involving the roles of NDRG1 and the correlation between it and tumor were collected and reviewed. Results NDRG-1, has a number of important functions such as in organism responses in hypoxia, histological differentiation, and so on, especially plays a significant role in generation, metastasis, and invasion of cancer. Conclusion NDRG1 may be a candidate of metastasis relevant gene for cancer and may serve as a useful prognostic marker of carcinoma.
Objective To explore the values of telomerase in the diagnosis, therapy and prognostic parameter of colorectal cancer. Methods Telomerase activity in colorectal cancer, peri-cancerous and normal mucosa was detected by PCRTRAP-ELISA assay. Results The positive rates of telomerase in colorectal cancer, peri-cancerous and normal mucosa were 84.8%, 20.0% and 0% respectively. 66.7% of the early stage colorectal cancer expressed telomerase. Telomerase activity was reversely correlated with tumor differentiation.Conclusion Telomerase may be an earlier event of malignant progression in colorectal cancer. It might be a parameter for diagnosis of colorectal cancer.
The effects of all-trans retinoic acid (ATRA) on primary gastric carcinoma models made by subcutaneous implanting gastric cancer to mice were observed. Thirty-two cancer bearing nude mice were randomly divided into 4 groups: control group (group Ⅰ)， ATRA low dose feeding group (100μg/day， group Ⅱ), moderate dose feeding group (300μg/day， group Ⅲ), and high dose feeding group (1 000 μg/day, group Ⅳ). The alteration of tumor growth, morphology, cytobiology, and immuno-histochemical assay were perfermed. The results showed significant inhibition of tumor growth and inducing differentiation in the group Ⅲ and group Ⅳ as compared with group Ⅰ (Ｐ＜0.01),and inhibited expression of p53, p21 protein in implanted tumor. The authors consider that ATRA has some effects of growth inhibition and differentiation on gastric cancer cells in vivo, and these is related to the inhibition of expression p53 and p21 onco-gene of cancer cells and accelerate apoptosis of carcinoma cells.
Objective To investigate the effects of IL-10 on lipopolysaccharide( LPS) -induced MyD88 /NF-κB signaling activation. Methods Ana-1 macrophages were divided into a LPS group and a LPS + IL-10 group. The cells and the culture supernatant were collected at 0, 0. 5, 1, and 2 hours respectively. The expression levels of NF-κB p65 and MyD88 in cytoplasm and nucleus were detected by Western blotting. The concentration of TNF-αin the culture supernatant was determined by ELISA. Results Through 0 to 2 hours, MyD88 expression increased significantly after LPS stimulation. The expression was attenuated by the pretreatment of IL-10, which returned to normal levels at 2 hours( 8. 8 ±0. 3 vs 21. 4 ±1. 8,P lt;0. 05) . IL-10 had no effect on total expression of NF-κB, but decreased nuclei / cytoplasm ratio of NF-κB p65 after LPS stimulation. The ratio was lower in the LPS + IL-10 group compared and the LPS group at 1 hour and 2 hour ( 1. 1 ±0. 1 vs 2. 4 ±0. 4, 0. 6 ±0. 7 vs 3. 1 ±0. 6, P lt; 0. 05) . Consequently, IL-10 pretreatment decreased TNF-α concentration after LPS stimulation at 1 hour and 2 hours [ ( 222. 5 ±33. 5) pg/mL vs ( 365. 2 ±22. 7) pg/mL, ( 212. 7 ±15. 9) pg/mL vs ( 566. 2 ±31. 5) pg/mL, P lt;0. 05] .Conclusion IL-10 attenuates inflammation via MyD88 /NF-κB signal pathway depression.
Objective To explore the expression of myeloid differentiation protein2 ( MD-2) in rat lung and its role in acute lung injury ( ALI) induced by lipopolysaccharide ( LPS) . Methods Twenty male SD rats were randomly divided into a LPS group and a control group. The wet/dry ratios of lung tissues were measured and the histological changes of lung tissues were observed under microscope. Alveolar macrophages were collected from bronchial alveolar lavage fluid ( BALF) . The MD-2 mRNA and protein expressions were detected by RT-PCR, Western blot, and immunohistochemistry respectively. The MD2-siRNA oligo were transfected into NR8383 cells and 1 μg/mL LPS was used to stimulate the cells. The expressions of MD-2 mRNA and protein were detected by RT-PCR and Western blot. The levels of TNF-αin rat serum and cell culture supernatant were detected by ELISA. Results Compared with the control group, the expressions of MD-2 mRNA and protein in alveolar macrophages and lung tissue were elevated ( P lt;0. 01) , as well as the level of TNF-αin rat serum. The expressions of MD-2 mRNA and protein in NR8383 cell and the level ofTNF-αin supernatant increased obviously after LPS stimulation ( P lt;0. 01) . There were no changes of MD-2 mRNA and protein expressions and TNF-α of NR8383 cells treated by MD-2 siRNA with or without LPS stimulation ( P gt;0. 05) . Conclusions The expression of MD-2 in lung increases obviously after challengedby LPS. KnockdownMD-2 gene of NR8383 cell byMD-2 siRNA can inhibit TNF-αsecretion induced by LPS stimulation.MD-2 may play an important role in rat ALI induced by LPS.
Objective To isolate，culture and expand bone marrow mesenchymal stem cells （MSCs） in vitro，induce MSCs to differentiate directionally towards chondrocytes，and provide experimental basis for clinical application of MSCs and construction of tissue engineering tracheal cartilage. Methods Cultured MSCs were isolated from bone marrow of Sprague-Dawley rats，purified using adherence separation，and identified by flow cytometry analysis. Transforming growth factor β1 （TGF-β1）and insulin-like growth factor 1 （IGF-1） were used as main induction factors to induce MSCs to differentiate directionally towards chondrocytes. The expression of collagen typeⅡwas evaluated by immunocytochemical staining 21 days after induction. Light microscope and electron microscope were used to observe tiny and ultrastructural changes of the cells before and after induction. Results The expression of collagen typeⅡwas positive by immunocytochemical staining 21 days after induction. MSCs were fusiform before induction under light microscope and electron microscope. After induction，the cells became larger，polygon，star-shaped or triangular. Transmission electron microscope showed that the cells had abundant organelles，larger nuclei and more nucleoli after induction. Conclusion Abundant organelles，larger nuclei and more nucleoli are the ultrastructure changes of chondrocytes differentiated from MSCs，indicating that the cells are active in differentiation and metabolism.
Objective To explore the induction of cardiomyogenesis of microRNA-129 （mir-129） in rat bone marrowmesenchymal stem cells （BM-MSCs） and its mechanism. Methods BM-MSCs were isolated from Sprague-Dawley rats and cultured in vitro. Overexpression of mir-129 or both mir-129 and glycogen synthase kinase-3β （GSK-3β） in BM-MSCs was produced with a lentiviral vector system. All the BM-MSCs were divided into four groups: control group （MSCs），Lentiviral vectors＋MSCs group （Lv-MSCs），mir-129 transfection group （mir-129-MSCs），and mir-129＋GSK-3βdouble transfection group （mir-129＋GSK-3β-MSCs）. Five-Azacytidine （5-Aza） （10 μmol/L） was used to induce BM-MSCsdifferentiation into cardiomyocytes. On the 1st，5 th，10 th，15 th and 20 th day after induction，realtime-PCR was performedto detect mRNA levels of GATA-4，Nkx2.5 and MEF-2C. On the 10 th，15 th and 20 th day after induction，Western blottingwas performed to examine expression levels of cTnI，Desmin，GSK-3β，phosphorylated β-catenin and dephosphorylated β-catenin. Results Compared with the control group，at respective time points，mRNA levels of cardiomyogenic genes and expression levels of cardiomyocyte-related proteins of mir-129 transfection group were significantly elevated，theexpression level of GSK-3β was significantly decreased，and the ratio of dephosphorylated/phosphorylated β-catenin was significantly elevated. When both mir-129 and GSK-3β were overexpressed in BM-MSCs，mRNA levels of cardiomyogenicgenes and expression levels of cardiomyocyte-related proteins were significantly lower than those of mir-129 transfection group，and the ratio of dephosphorylated/phosphorylated β-catenin was significantly decreased. Conclusion Overexpression of mir-129 can promote cardiomyogenesis of rat BM-MSCs possibly via inhibiting GSK-3β production and thus decreasing the inhibition of phosphorylation of β-catenin which then enters the nucleus and activates downstream signaling pathways that regulate cardiomyogenic differentiation of BM-MSCs.