Objective To confirm the stimulating effect of simvastatin on BMSCs of SD rats osteogenic differentiation, and to further study the role of Wnt signal ing pathway in this process. Methods BMSCs derived from the tibia and femur of 6-week-old female SD rats were cultured in vitro．Two groups were establ ished: control group and experimental group. After the 2nd passage, the cells of experimental group were treated with simvastatin (1 × 10-7mol/L) and the cells of control group with absolute ethyl alcohol and PBS. ALP staining was used at 7 days and von Kossa staining was appl ied at 28 days to assess osteoblastic differentiation and mineral ization. Real-time quantitative PCR was performed to evaluate theexpressions of Axin2, β-catenin, osteocalcin (OC), frizzled-2, Lef-1, and Wnt5a mRNA at 7 days and 14 days after simvastatin treatment. Results The observation of inverted phase contrast microscope showed that the majority of cells were polygonal and triangular in the experimental group, and were spindle-shaped in the control group at 7 days. The ALP staining showed blue cytoplasm, the positive cells for ALP staining in the experimental group were more than those in the control group at 7 days. The von Kossa staining showed that mineral ization of extracelluar matrix at 28 days in two groups, but the mineral ization in the experimental group was more obvious than that in the control group. The expression of Axin2 mRNA was significantly lower, and frizzled-2, Lef-1 mRNA were significantly higher in the experimental group than in the control group (P lt; 0.05) at 7 days, while the mRNA expressions of Axin2, OC, frizzled-2, Lef-1, and Wnt5a were significantly higher in the experimental group than in the control group at 14 days (P lt; 0.05). Conclusion Simvastatin can promote the osteogenic differentiation of BMSCs and change the expression of mRNA of some components of Wnt signal ing pathway.
Stem cells are crucial for embryonic development and in the maintenance of adult cellular homeostasis. Understanding the regulatory network of stem cells, including embryonic and adult stem cells, will allow us to learn the pathogenesis and possibly design novel approaches to treat many diseases (such as cancer and degeneration). The retinoblastoma (Rb) pathway controls cellular proliferation, differentiation and death. More and more evidences support an important role of Rb activity in the biology of stem and progenitor cells. Transiently inactivating Rb pathway might favor the expanding of functional stem cell populations, thus have values in the future stem cell applications.
Objective To evaluate the effect of integrin-linked kinase (ILK) in the process of retinal neovascularization induced by vascular endothelial growth factor (VEGF). Methods The ILK activities of retinal choriodal endothelial cell line RF/6A were inhibited by LY294002 or siRNA knockdown. VEGF-induced changes of cell adhesion, proliferation, migration and endothelial cell tube-formation were measured then. The in-vivo effects of ILK were also assessed by intraperitoneal injection of LY294002 into an animal model of RNV. Results The cell adhesion measurements of control group, VEGF group, VEGF＋LY294002 group and VEGF＋siRNA group were 0.0726plusmn;0.01961, 0.1137plusmn;0.02631, 0.0837plusmn;0.01503 and 0.0853plusmn;0.02454 , respectively. The difference was statistically significant between VEGF group and control group（t =4.211，Plt;0.01）, and between (VEGF＋LY294002) group or (VEGF＋siRNA) group and control group (t =3.074, 2.91，Plt;0.01). The cell proliferation results of control group, VEGF group and VEGF＋LY294002 group were 0.4162plusmn;0.1392, 0.6412plusmn;0.2420, 0.4476plusmn;0.1834 , respectively. The difference was statistically significant between VEGF group and control group（t=2.608，Plt;0.05）, and between (VEGF＋LY294002) group and VEGF group（t=2.244，Plt;0.05）.The cell migration results of control group, VEGF group and VEGF＋LY294002 group were 83.66plusmn;30.283, 248plusmn;74.748, 138.5plusmn;38.167, respectively. The difference was statistically significant between VEGF group and control group（t=5.436，Plt;0.01）, and between (VEGF＋LY294002) group and VEGF group（t=3.682，Plt;0.01）. There was no obvious tube-formation after ILK activity was inhibited or knocked down. The non-perfusion areas were increased from （62798plusmn;16995.62）mu;m2 to （84722.65plusmn;10435.01）mu;m2 after intraperitoneal injection of LY294002 into animal model of RNV, the difference was statistically significant（t=3.476，Plt;0.01）. Conclusions ILK may play an important role in the process of VEGF-induced retinal neovascularization by regulating the cellular adhesion, proliferation, migration and tube-formation, as all those cellular functions were supressed obviously after the ILK activity was inhibited by LY294002 or the ILK expression was knocked down by siRNA.
Continuous activation of Janus kinase (JAK)- signal transduction and activator of transcription (STAT) signaling pathway is prevalent in leukemia cells, and it has been found that this pathway plays an important role in acute leukemia (AL). JAK2/JAK1 gene mutations are found in both acute myelocytic leukemia and acute lymphoblastic leukemia and may have implications for the treatment and overall prognosis of the disease. Among the STAT family members, STAT3 and STAT5 proved to be key factors in AL. These gene mutations may provide new targets and new ideas for the treatment of AL. This article provides a review of the research progress of JAK-STAT signaling pathway, related gene mutations and AL.
Objective To investigate changes of TLR2 mRNA expression in lung of a mouse model of Chlamydia Pneumoniae pneumonitis, and to explore the possible mechanism of signal transduction. Methods Ninety-six male C3H/HeJ mice were randomly divided into four groups as follows: a control group, a model group, a SB203580 intervened group, and a pyrrolidine dithiocarbamate( PDTC) intervened group. Chlamydia Pneumoniae pneumonitis was induced by intranasally inoculated with 4. 0 ×106 IFU/mL of C. Pneumoniae per mouse in the model group and two intervened groups. Then the intervened groups were intraperitoneally injected with the p38MAPK inhibitor SB203580 and nuclear factor kappa B ( NF-κB)inhibitor PDTC, respectively. Six mice in each group were randomly killed in 1st, 4th, 7th and 14th day. The expressional changes of TLR2 mRNA in the mice lung tissue were measured by semi-quantitative RT-PCR. The concentrations of TNF-α in the lung homogenate were measured by ELISA. Results TLR2 mRNA expression in the lung tissue significantly increased after C. Pneumoniae infection, peaking at 4th and 7th days, then decreased after 14th day. Tumor necrosis factor-α( TNF-α) was also elevated in the lung tissue after C. Pneumoniae challenging. Both SB203580 and PDTC treatment effectively inhibited TNF-αand TLR2 mRNA expressions in lung. The inhibitory effect was more obvious by SB203580 treatment. Conclusion C. Pneumoniae can upregulate the expressions of TLR2 and TNF-α in lung, and TLR2/MAPK and TLR2 /NF-κB signal pathways may be involved in Chlamydia Pneumoniae pneumonitis.
ObjectiveTo summarize the therapeutic targets of pancreatic cancer (PC). MethodsThe related literatures about the therapeutic targets of PC were reviewed. ResultsPC was one of the most challenging tumor in worldwide, and was characterized as a highly aggressive disease with poor overall prognosis and a high mortality rate. The hallmark of PC was its poor response to radio-and chemo-therapy. Current chemotherapeutic regimens could not provide substantial survival benefit with a clear increase in overall survival. Recently, several new approaches which could significantly improve the clinical outcome of PC had been described, involving signal-transduction pathways, immune response, stroma reaction, and epigenetic changes. ConclusionsMany therapeutic targets are involved in the treatment of PC. As current therapies failed to significantly improve the progression and the survival of PC, new therapeutic approaches and clinical studies are strongly required.
ObjectiveTo observe the regulation of PTB-associated splicing factor (PSF) exerts on phosphatidylinositol 3 kinase (PI3K)/Akt signaling pathway in cultured retinal pigment epithelial (RPE) cells. MethodsARPE-19 RPE cells were divided into five groups including PSF overexpression (0.25, 0.50, 1.00 μg of pEGFP-C2-PSF plasmid DNA), PSF overexpression control (pEGFP-C2 empty vector DNA), PSF inhibition (0.25, 0.50, 1.00 μg of pGenesil-PSF-RNAi plasmid DNA), PSF inhibition control (pGenesil-scramble-siRNA empty vector) and sham transfected group (treated with lipofactamine 2000 reagent, but without adding plasmid DNA) groups. After transfecting with plasmid DNA, the cells were stimulated with insulin-like growth factor-1 (IGF-1). IGF-1-stimulated ARPE-19 cells were also treated with Wortmannin and /or PSF over-expression. WST-1 assay was used to detect the proliferation rates, the VEGF mRNA levels were analyzed using real time polymerase chain reaction (PCR), the levels of phosphorylation Akt and total Akt expression were measured by western blotting. ResultsAfter IGF-1 stimulation, the difference of the cell proliferation rates between PSF overexpression group, PSF overexpression control group and sham transfected group was statistically significant (F=29.728, P<0.05). The difference of the cell proliferation rates between PSF inhibition group, PSF inhibition control group and sham transfected was also statistically significant (F=14.121, P<0.05). Compared with control group, the VEGF mRNA levels was decreased in PSF overexpression group (P=0.000 3), but increased in PSF low expression group (P=0.030 9). Furthermore, overexpression of PSF could down-regulate the activation of pAkt after IGF-1 stimulation. When combined with Wortmannin treatment, the VEGF mRNA levels in PSF overexpression group was significantly lower than the control group (P<0.05). ConclusionsAfter IGF-1 treatment, PSF plays a role in suppressing the proliferation and VEGF expression in RPE cells by inactivating PI3K/Akt signaling pathway.
Objective To investigate the expression of ectodysplasin (EDA) genesignaling and its relationship with the development and regeneration of sweat glands. Methods The articles concerned in the latest years wereextensively reviewed. Results EDA gene is an important signaling pathway associated with the developmental procedure of sweat glands in early fetal stage. Abnormality or depletion of function in sweat glands partially owed to the defect of EDA gene. Conclusion EDA signaling has its biological significance in inducing development and morphogenesis of sweat glands and in maintaining physiological function of skin. It could be a new approach to repair or regenerate the sweat glands for clinical therapy by regulating the expression of EDA gene.
ObjectiveTo observe the expressions of p-mTOR, p-S6K1 and p-4EBP1 in the human brain with refractory epilepsy and to explore the role of mTOR signaling pathway in intractable epilepsy. MethodsCollecting the brain tissues of 24 patients with refractory epilepsy for surgical treatment from March 2010 to July 2011 as experimental group in hospitalized Epilepsy Center at the First Hospital of Jilin University, Changchun City. Collecting temporal lobe or frontal lobe brain tissue from 6 autopsy of patients who had emergency surgery for neurosurgery brain tranma during the same period. Using immunohistochemistry to observe the expression of p-mTOR, p-S6K1, p-4EBP1 in the two groups of brain tissues, and analyzed statistically. Results① p-mTOR, p-S6K1 and p-4EBP1 were expressed in both neurons and glial cells of experimental and control groups. P-mTOR, p-S6K1, p-4EBP1 positive cells of experimental group was significantly higher than the control group(P<0.01). The expression level of p-mTOR, p-S6K1, p-4EBP1 in the brain tissues of patients with different seizure frequency and with different duration:the expression level of p-mTOR, p-S6K1, p-4EBP1 in the brain tissues of patients in the group of epilepsy 10 years and more than 10 years were significantly higher than the group of epilepsy fewer than 10 years and the difference was statistically significant (P<0.05). ② The structural changes of brain tissues were observed under the optical microscope and electron microscope. Under the optical microscope:the distribution of nerve cells were uneven, the nucleus was vacuolated, the cytoplasm was less and gliosis. Under the transmission electron microscope:the number of neurons was reduced, nuclear condensation, the heterochromatin was increased, the nucleolus were dissymmetry and the nuclear membrane was breakage, also see neurons became psychotic, cell body became smaller, astrocyte cell membrane became edema, chromatin was dissymmetry, some mitochondrial were swelling and transparent, and others were vacuolated, the mitochondrial crista was in disorder. ③ p-mTOR, p-S6K1 and p-4EBP1 are expressed in the cerebral vascular of the brain in both experimental and control groups.In the experimental group, the expression is high concentration.In the control group, the expression is scattered in a small amount. Conclusionsp-mTOR, p-S6K1 and p-4EBP1 are widely expressed in neurons and glial cells with refractory epilepsy, which was significantly increased compared with control group. The expression of p-mTOR, p-S6K1and p-4EBP1 is related to frequency of epileptic seizures and course.