ABSTRACT
PURPOSE: Prolactinoma (prolactin-secreting pituitary adenoma) is one of the most common estrogen-related functional pituitary tumors. As an agonist of the dopamine D2 receptor, bromocriptine is used widely to inhibit prolactinoma progression. On the other hand, it is not always effective in clinical application. Although a dopamine D2 receptor deficiency contributes to the impaired efficiency of bromocriptine therapy to some extent, it is unknown whether there some other underlying mechanisms leading to bromocriptine resistance in prolactinoma treatment. That is the main point addressed in this project. MATERIALS AND METHODS: Human prolactinoma samples were used to analyze the S-phase kinase associated protein 2 (SKP2) expression level. Nutlin-3/adriamycin/cisplatin-treated GH3 and MMQ cells were used to analyze apoptosis in SKP2 overexpression or knockdown cells. SKP2 expression and the interaction partners of SKP2 were also detected after a bromocriptine treatment in 293T. Apoptosis was analyzed in C25 and bromocriptine-treated GH3 cells. RESULTS: Compared to normal pituitary samples, most prolactinoma samples exhibit higher levels of SKP2 expression, which could inhibit apoptosis in a p53-dependent manner. In addition, the bromocriptine treatment prolonged the half-life of SKP2 and resulted in SKP2 overexpression to a greater extent, which in turn compromised its pro-apoptotic effect. As a result, the bromocriptine treatment combined with C25 (a SKP2 inhibitor) led to the maximal apoptosis of human prolactinoma cells. CONCLUSION: These findings indicated that SKP2 inhibition sensitized the prolactinoma cells to bromocriptine and helped promote apoptosis. Moreover, a combined treatment of bromocriptine and C25 may contribute to the maximal apoptosis of human prolactinoma cells.
Subject(s)
Humans , Apoptosis , Bromocriptine , Half-Life , Hand , Pituitary Neoplasms , Prolactinoma , Receptors, Dopamine D2 , S-Phase Kinase-Associated ProteinsABSTRACT
Objective To explore the role of microRNA-206 (miR-206) in peripheral blood mononuclear cells (PBMCs) in infantile bronchiolitis caused by respiratory syncytial virus (RSV).Methods Thirty-five cases of infantile bronchiolitis and 25 cases of healthy controls were enrolled into the current study.PBMCs were isolated from the peripheral blood of both healthy subjects and those with infantile bronchiolitis in the acute and the convalescent stages.Total RNAs were extracted from PBMCs which were stimulated by phorbol-12-myristate-13-acetate (PMA) and Ionomycin, and then the RNA was transcribed reversely into cDNA.The expressions of miR-206 and Kruppel-like transcription factor 4 (KLF4) were detected by real-time quantitative polymerase chain reaction (qRT-PCR) method.Plasma interleukin-17 (IL-17) was determined by enzyme linked immunosorbent assay (ELISA).Results There was a significant difference in miR-206 levels of children with RSV bronchiolitis in the acute stage(0.055 ±0.018) and the convalescent stage(0.187 ±0.069) as well as the healthy controls(0.204 ± 0.075).Through pairwise comparison, the miR-206 levels in the children in the acute stage were significantly lower than those in the convalescent stage and healthy control group (P ＜ 0.01), but no statistical significance was found between the convalescent stage group and healthy control group(P ＞ 0.05).The levels of KLF4 mRNA of children in the acute stage,convalescent stage as well as the healthy subjects were 0.588 ± 0.161,0.086±0.024,0.075 ±0.019, respectively,which was significantly difference (P ＜ 0.01).The levels of IL-17 were (58.26 ±25.88) ng/L, (9.87 ± 3.01) ng/L, (7.65 ± 2.16) ng/L, respectively (P ＜ 0.01).Compared to the convalescent and the normal control group,both the KLF4 mRNA and IL-17 levels were markedly higher in the acute stage (P ＜ 0.01), but there were no significant differences between children with RSV bronchiolitis in convalescent stage and in the healthy controls (P ＞ 0.05).Furthermore, the result of this study showed a negative correlation between the expression of miR-206 and KLF4(r =-0.624 ,P ＜0.01)and IL-17 (r =-0.609 ,P ＜0.01) in children in the acute stage and a positive correlation between KLF4 mRNA and IL-17 in children in the acute stage (r =0.662, P ＜ 0.01).Conclusion The levels of miR-206 may play a role in the onset of RSV associated post-bronchiolitis (PB) and the low expression of miR-206 in children infected with RSV may increase the susceptibility to PB.
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Objective To fabricate cartilage extracellular matrix (ECM) oriented scaffolds and investigate the attachment, proliferation, distribution and orientation of bone marrow mesenchymal stem cells (BMSCs) cultured within the scaffolds in vitro. Methods Cartilage slices were shattered in sterile phosphate-buffered saline (PBS) and the suspension were differentially centrifugated untill the micro- fiber of the cartilage extracellular matrix was disassociated from the residue cartilage fragments. At last the supernatant were centrifugated, the precipitation were collected and were made into 2%-3% suspension. Using unidirectional solidification as a freezing process and freeze-dried method, the cartilage extracellular matrix derived oriented scaffolds was fabricated. The scaffolds were then cross-linked by exposure to ultraviolet radiation and immersion in a carbodiimide solution. By light microscope and scan electron microscope (SEM) observation, histological staining, and biomechanical test, the traits of scaffolds were studied. After being labelled with PKH26 fluorescent dye, rabbit BMSCs were seeded onto the scaffolds. The attachment, proliferation and differentiation of the cells were analyzed using inverted fluorescent microscope. Results The histological staining showed that toluidine blue, safranin O, alcian blue and anti-collagen Ⅱ immunohistochemistry staining of the scaffolds were positive. A perpendicular pore-channel structures which has a diameter of 100 μm were verified by light microscope and SEM analysis. The cell-free scaffolds showed the compression moduli were (2.02±0.02) MPa in the mechanical testing. Inverted fluorescent microscope showed that most of the cells attached to the scaffold. Cells were found to be widely distributed within the scaffold, which acted as a columnar arrangement. The formation of a surface cells layer was found on the surface of the scaffolds which resembled natural cartilage. Coclusion The cartilage extracellular matrix derived oriented scaffolds have promising biological, structural, and mechanical properties.
ABSTRACT
Credit system is suitable for all-round development of students and teaching personality and it is an important component of the modern university system.The paper mainly studies the credit system as a learning management system and explores the form of the examination and assessment patterns.It also puts forward some specific measures and ideas about how to improve and perfect examination and assessment modes.