Objective To observe the effects of bevacizumab on aquaporin 4 (AQP4) expression in human retinal Muuml;ller cells in vitro under hypoxia. To explored the mechanism of treating retinal edema with bevacizumab. Methods Human Muuml;ller cells were cultured using the enzymatic digestion method. Transmission electron microscopic analysis and immunofluorescence staining identified Muuml;ller cells. With semi-quantitative reverse transcription polymerase chain reaction (RT-PCR), the expression of AQP4 mRNA and vascular endothelial growth factor （VEGF） mRNA in Muuml;ller cells cultured under different concentration of COCl2 for different hours were observed. The expression of AQP4 mRNA in Muuml;ller cells cultured using CoCl2 precultured with 200 mu;g/ml bevacizumab was measured. Results More than 95% of primary cells showed positive reaction to glial fibrillary acidic protein, glutamine synthetase, vimentin and alpha;-smooth muscle actin with immunofluorescence staining. Characteristic 8-10 nm intracellular filaments could be seen in the cytoplasm viewed with transmission electron microscopy. The results using RT-PCR showed that CoCl2 increased the AQP4 and VEGF mRNA expression in Muuml;ller cells in a dose and time dependent manner (r=0.952, 0.954;P＜0.05). The expression of AQP4 mRNA in Muuml;ller cells was increased by VEGF (F=12.43,P＜0.05). The expression of AQP4 mRNA was significantly decreased by bevacizumab (F=2 370.37，P＜0.05). Conclusion Bevacizumab can down-regulate the expression of AQP4 mRNA in human Muuml;ller cells under hypoxic conditions partially by VEGF path, which may be a mechanism for treating retinal edema with bevacizumab.
ObjectiveTo investigate the effects and mechanisms of G protein-coupled receptor 91 (GPR91) on blood-retinal barrier (BRB) in diabetic rats.
MethodsA lentiviral vector of shRNA targeting rat GPR91 and scrambled shRNA were constructed. Healthy male Sprague-Dawley (SD) rats were selected in this study. The 60 rats were randomized into 4 groups and treated as follows:(1) control group (Group A, n=15), the rats received injections of an equal volume of 0.1% citrate buffer; (2) streptozocin (STZ) group (Group B, n=15), the rats received injections of STZ; (3) LV.shScrambled group (Group C, n=15), diabetic rats received an intravitreal injection of 1 μl 1×108 TU/ml scrambled shRNA lentiviral particles at 2 weeks after the induction of diabetes; (4) LV.shGPR91 group (Group D, n=15), diabetic rats received an intravitreal injection of 1 μl 1×108 TU/ml pGCSIL-GFP-shGPR91 lentiviral particles. At 12 weeks after intravitreal injection, immunohistochemistry and Western blot were used to assess the expression of GPR91, p-extracellular signal-regulated kinase(ERK)1/2, t-ERK1/2, p-Jun N-terminal kinase (JNK), t-JNK, p-p38 mitogen-activated protein kinase (MAPK) and t-p38 MAPK. Haematoxylin and eosin (HE) staining and Evans blue dye were used to assess the structure and function of the retinal vessel. Immunohistochemistry enzyme-linked immunosorbent assay (ELISA) was used to test the protein level of VEGF.
ResultsImmunohistochemistry staining showed that GPR91 was predominantly localized to the cell bodies of the ganglion cell layer. Western blot showed that GPR91 expression in Group D decreased significantly compared with Group C (F=39.31, P < 0.01). HE staining showed that the retina tissue in Group B and C developed telangiectatic vessels in the inner layer of retina, while the telangiectatic vessels attenuated in Group D. It was also demonstrated in Evans blue dye that the microvascular leakage in Group D decreased by (33.8±4.11)% compared with Group C and there was significant difference (F=30.35, P < 0.05). The results of ELISA showed the VEGF secretion of Group B and C increased compared with Group A and the VEGF expression in Group D was significantly down regulated after silencing GPR91 gene (F=253.15, P < 0.05).The results of Western blot indicated that compared with Group A, the expressions of p-ERK1/2, p-JNK and p-p38 MAPK were significantly upregulated (q=6.38, 2.94, 3.45;P < 0.05). Meanwhile, the activation of ERK1/2 was inhibited by GPR91 shRNA and the difference was statistically significant (F=22.50, P < 0.05).
ConclusionsThe intravitreal injection of GPR91 shRNA attenuated the leakage of BRB in diabetic rats. GPR91 regulated the VEGF release and the leakage of BRB possibly through the ERK1/2 signaling pathway.
Objective To explore the expression of survivin gene in retinoblastoma (RB) and its relationship with the stages and histodifferentiation degree of RB and the expression of p53、bcl-2 proteins. Methods Expression of survivin, p53 and bcl-2 proteins in 38 RB conventional paraffin samples were detected with survivin, p53 and bcl-2 monoclonal antibodies respectively by immunohistochemical assay. The expression of survivin of normal retina in 6 control samples was observed. Results In 38 cases of RB, positive expression of survivin was found in 20 (52.6%); while none of the 6 normal retinal tissue expressed survivin, which had significant difference between the two group (P＜0.05). The positive expression of survivin did not correlate with sex of patient, disease stages and histological type (P＞0.05). In 38 RB cases, positive expression of p53 was in 25 with the rate of 65.8%, and of bcl-2 in 18 with the rate of 47.4%. The positive-expressed rates were much higher in positive-expressed p53 and bcl-2 group than those in the negative-expressed p53 and bcl-2 group(P＜0.05). Conclusion The increase of the expression of survivin implies that it may take part in the occurrence and development of RB; the interaction among survivin, p53 and bcl-2 may participate in the access and the course of RB. (Chin J Ocul Fundus Dis，2004，20：215-217)
Protein-energy wasting is one of the common complications of maintenance hemodialysis patients. It often causes decreased immune function, increased anemia, and decreased heart, brain, lung and other organ functions, resulting in decreased quality of life, decreased long-term survival rate, and increased mortality. This article discusses the causes, diagnosis, evaluation methods, intervention and prevention of protein-energy wasting in maintenance hemodialysis patients, and aims to provide a theoretical basis for evaluating the nutritional status, early intervention for protein-energy wasting, and improving prognosis and quality of life of maintenance hemodialysis patients.
The prevalence, incidence, and medical expenses of end-stage renal disease (ESRD) is extremely high in Taiwan, China; so decreasing the incidence of ESRD is a major work for kidney disease prevention in Taiwan, China. Current chronic kidney disease (CKD) guideline suggests multidisciplinary team (MDT) care for CKD patient with estimated glomerular filtration rate (eGFR) less than 30 mL/(min·1.73 m2). MDT includes not only nephrologist but also nursing specialty, dietitian, social worker, psychologist, and other professional personnel. The aim of the MDT care is to preserve renal function, decrease complications, provide nutrient support and nephrotoxic drug consultation, establish the concept of renal replacement therapy and preparation for dialysis access, provide the renal transplantation information, and give the psychosocial support. These cares should provide to CKD patients one year before starting renal replacement therapy. The MDT care for CKD could delay the progression from CKD to ESRD, lower the mortality and hospitalization of CKD, slow the renal function decline, provide better medical care and quality of life for patients, and decrease the medical expenditures. Besides, advanced CKD patients receiving MDT care have higher arteriovenous access preparation rate that prevent the additional intervention and hospitalization while starting dialysis. MDT care also decreases the hospitalization costs and medical expenditures, and decrease 3-year mortality rate after dialysis initiation. The further developing MDT care includes: (1) providing personalized renal care and treatment model, and intergraded care by cardiology-nephrology-diabetes-neurology model; (2) new iCKD care with health management platform and care mode combined with communication technology; (3) shared decision making for choice of renal replacement therapy; (4) advance care planning clinic for palliative treatment of ESRD. All MDT care hopes to establish a person-oriented care policy, provides a better quality care model, not only for the patient’s personalized medical care, but also hopes to improve the overall kidney disease care and prevention work. In addition, we can extend the CKD prevention and treatment experience to other countries worldwide.
Protein structure determines function, and structural information is critical for predicting protein thermostability. This study proposes a novel method for protein thermostability prediction by integrating graph embedding features and network topological features. By constructing residue interaction networks (RINs) to characterize protein structures, we calculated network topological features and utilize deep neural networks (DNN) to mine inherent characteristics. Using DeepWalk and Node2vec algorithms, we obtained node embeddings and extracted graph embedding features through a TopN strategy combined with bidirectional long short-term memory (BiLSTM) networks. Additionally, we introduced the Doc2vec algorithm to replace the Word2vec module in graph embedding algorithms, generating graph embedding feature vector encodings. By employing an attention mechanism to fuse graph embedding features with network topological features, we constructed a high-precision prediction model, achieving 87.85% prediction accuracy on a bacterial protein dataset. Furthermore, we analyzed the differences in the contributions of network topological features in the model and the differences among various graph embedding methods, and found that the combination of DeepWalk features with Doc2vec and all topological features was crucial for the identification of thermostable proteins. This study provides a practical and effective new method for protein thermostability prediction, and at the same time offers theoretical guidance for exploring protein diversity, discovering new thermostable proteins, and the intelligent modification of mesophilic proteins.
Objective
To investigate the effects of cytokines on the expression of syndecan-1 in cultured human retinal pigment epithelial (RPE) cells and the signal transduction pathway.
Methods
Reverse transcription polymerase chain reaction and immunofluorescence staining were used to detect the expression of syndecan-1 mRNA and protein in normal RPE cells. The expression of syndecan-1 in RPE cells stimulated by different cytokines was detected and quantitatively analyzed by image process of immunofluorescence. The stimulation included 7 and 35 ng/ml tumor necrosis factor (TNF)-alpha; for 24 hours, 1 and 6 mu;g/ml lipopolysaccharide (LPS) for 11 hours, 7 ng/ml TNF-alpha; for 0 to 24 hours (once per 2 hours, and 13 times in total), and 30% supernatant of monocyte/macrophage strain (THP-1 cells) for 3, 14 and 43 hours. The effect of 30% supernatant of THP-1 cells was assayed after pretreated by PD098059［the specific inhibitor of extracellular signal regulated kinase(ERK) 1/2］for 2 hours. After exposed to 30% supernatant of THP-1 cells for 3 hours and treated by 0.25% trypsin for 5 minutes, RPE cells attaching was evaluated by methyl thiazolyl tetrazolium assay.
Results
In normal human RPE cells, expressions of syndecan-1 mRNA and protein were detected, and b syndecan-1 positive yellowish green fluorescence was found in the cell membrane and cytoplasm while light green fluorescence was in the nucleus. As the concentration and stimulated time of TNF-alpha; or LPS increased, the fluorescence intensity decreased（Plt;0.01）, and after exposed to 30% supernatant of THP-1 cells, weaker fluorescence intensity was detected (Plt;0.001). Pretreatment with 50 mu;mol/L PD098059 for 2 hours partly inhibited the effect of THP-1 cells supernatant. After exposed to 30% supernatant of THP-1 cells for 3 hours, the number of attached cells decreased compared with the controls（Plt;0.05）.
Conclusions
TNF-alpha; and LPS down-regulate the expression of syndecan-1 in cultured human RPE cells. The supernatant of THP-1 cells down-regulates the expression of syndecan-1 and lessens the cells attaching, which is at least mediated by ERK 1/2 pathway.
(Chin J Ocul Fundus Dis, 2006, 22: 113-116)
Abstract： Objective To study the changes of the cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) expression of isolated rat hearts after diazoxide preconditioning (DPC), and to explore the possible mechanism of cAMP signaling pathway in myocardial protection by DPC. Methods Isolated working heart Langendorff perfusion models of 40 Wistar rats were set up and were divided randomly into four groups. For the ischemia reperfusion injury(I/R) group (n=10), 30 min of equilibrium perfusion was followed by a 60 min reperfusion of KrebsHenseleit (K-H) fluid. The DPC group (n=10) had a 10 min equilibrium perfusion and two cycles of 5 min of 100 μmol/L diazoxide perfusion followed by a 5 min diazoxidefree period before the 30 min ischemia and the 60 min reperfusion of K-H fluid. The blank control group (control group, n=10) and the Dimethyl Sulphoxide(DMSO) group (n=10) were perfused with the same treatment as in the DPC group except that diazoxide was replaced by natriichloridum and DMSO respectively. The activity of creatine kinase (CK) in coronary outflow, the activity of malonyldialdehyde (MDA) and superoxide dismutase (SOD) in myocardium were detected. And the scope of myocardial infarction and the concentrations of myocardial cAMP and PKA were also assessed. Results Compared with the I/R group, the level of MDA for the DPC group decreased significantly (8.28±2.04 nmol/mg vs. 15.52±2.18 nmol/mg, q=11.761,Plt;0.05), the level of SOD increased significantly (621.39±86.23 U/mg vs. 477.48±65.20 U/mg, q=5.598,Plt;0.05). After a 30 min reperfusion, compared with the I/R group, the content of CK decreased significantly (82.55±10.08 U/L vs. 101.64±19.24 U/L, q=5.598, Plt;0.05) and the infarct size reduced significantly (5.63%±9.23% vs.17.58%±5.76%, q=6.176,Plt;0.05) in the DPC group. The cAMP concentration in the DPC group was much higher than that in the I/R group (0.64±0.07 pmol/g vs. 0.34±0.05 pmol/g, q=14.738,Plt;0.05), and PKA concentration was also much higher than that in the I/R group ［17.13±1.57 pmol/(L·min·mg) vs. 12.85±2.01 pmol/(L·min·mg), Plt;0.05］. However, there were no significant differences between the I/R group, DMSO group and the control group in the above indexs (Pgt;0.05). Conclusion DPC significantly improves the releasing of cAMP and PKA, decreases oxygen free radicals, and relieves myocardial ischemia reperfusion injury. The cAMP signaling pathway may be involved in triggering the process of myocardial protection mechanisms of DPC.
ObjectiveTo verify the expression change of insulin-like growth factor-Ⅰ (IGF-Ⅰ) protein and its mRNA before and after Roux-en-Y gastric bypass surgery (RYGB) in obese rats, and to investigate the relationship between the expression of IGF-Ⅰ and proliferation/apoptosis of adipose cells.
Methods① Seventy male SD rats were raised at the SPF level circumstance and were randomly divided into control group (NC group, 10 rats) and high fat diet group (60 rats). Rats of high fat diet group were given specific high fat formula diet, rats of NC group were given particular formula diet. After 6 weeks, the body weights of the rats in high fat diet group were measured, and the 20 rats of top weight were selected. The 20 obese rats were randomly divided into 2 groups:gastric bypass (GB) group (n=10) and sham-operation group (SO group, n=10). RYGB were administered to the rats of GB group, and for rats of SO group, sham operations were performed. Rats of NC group did not receive any surgery. Inguinal adipose tissues[represented the subcutaneous adipose tissue (SAT)] and epididymal adipose tissues[on behalf of visceral adipose tissue (VAT)] were taken during operation in rats of GB group and SO group respectively (0.5 g), and 12 weeks after operation in all rats of three groups. The expressions of IGF-Ⅰ protein and its mRNA in adipose tissue were detected by Western blot and real-time fluorescence quantitative PCR. ② Transfection experiment. SAT cells were divided into blank control group (BC group, without transfection), IGF-Ⅰ(+) group (gene overexpression group), IGF-Ⅰ(+) empty vector group, IGF-Ⅰ(-) group (gene silencing group), and IGF-Ⅰ(-) empty vector group. Cells were transfected with corresponding vectors with 3 duplicated holes of each group. Cell viability and apoptosis assays were carried out in 48 hours after transfection. Expressions of protein kinase B (AKT), phosphorylated protein kinase B (p-AKT), phosphoinositide 3-kinase (PI3K), and phosphorylated phosphoinositide 3-kinase (p-PI3K) were detected by Western blot meanwhile. ③ Wortmannin experiment. SAT cells were divided into Wortmannin (+) IGF-Ⅰ(+) group, Wortmannin (+) IGF-Ⅰ(-) group, Wortmannin (-) IGF-Ⅰ(+) group, and Wortmannin (-) IGF-Ⅰ(-) group, which were transfected with corresponding vectors for 24 hours, then adding Wortmannin (0.1 mmol/L). After 24 hours, the expression levels of AKT, p-AKT, p-PI3K, PI3K, and GAPDH were detected by Western blot.
Results① PCR results showed that, in SAT, compared with preoperative GB group, the expression levels of IGF-Ⅰ mRNA and its protein in postoperative GB group were both lower (P < 0.01). However, the expression levels of IGF-Ⅰ mRNA and its protein between preoperative SO group and postoperative SO group showed no significant difference (P > 0.05). In VAT, the expression levels of IGF-Ⅰ mRNA and its protein in 5 groups showed no significant difference (P > 0.05). ② The MTT results showed that, IGF-Ⅰ(+) group harbored stronger proliferation abilities compared with its negative control group (P=0.04), whereas IGF-Ⅰ(-) group had lower abilities compared with its negative control group (P=0.04). The results of flow cytometry assay showed that, the apoptosis rate of IGF-Ⅰ(+) group was lower (P=0.04) than that of the corresponding negative control group, and it was higher in IGF-Ⅰ(-) group than that of the corresponding negative control group (P=0.04). ③ Compared with IGF-Ⅰ(+) empty vector group, p-PI3K/PI3K ratio (P=0.03) and p-AKT/AKT (P=0.04) ratio of IGF-Ⅰ(+) group were increased; compared with IGF-Ⅰ(-) empty vector group, p-PI3K/PI3K ratio (P=0.04) and p-AKT/AKT ratio (P=0.04) of IGF-Ⅰ(-) group were decreased. The p-AKT/AKT ratio of Wortmannin (-) IGF-Ⅰ(+) group was higher (P < 0.05) than that of Wortmannin (+) IGF-Ⅰ(+) group; the p-AKT/AKT ratio of Wortmannin (-) IGF-Ⅰ(-) group was lower than that of Wortmannin (-) IGF-Ⅰ(+) group (P < 0.05).
ConclusionsIGF-Ⅰ is involved in the accumulation of subcutaneous fat in rats. RYGB can significantly reduce the expression levels of IGF-Ⅰ mRNA and its protein in subcutaneous fat of rats, so as to achieve the effect of weight loss.
ObjectiveTo detect the expression of Liver X receptors (LXRs), protein phosphatase 1A (PPM1A), transforming growth factor-β1 (TGF-β1) and Smad2 in peripheral blood of bronchial asthma patients, and to explore whether LXRs and PPM1A are related to airway remodeling.MethodsSubjects were divided into healthy control group, mild and moderate asthma group and severe asthma group, with 30 subjects each. Lung function and high-resolution computed tomography examination were performed on patients with bronchial asthma to define airway remodeling. Peripheral blood was extracted and the serum levels of LXRα, LXRβ, PPM1A, TGF-β1 and Smad2 were detected after centrifugation. Then the data were analyzed.ResultsThe airway remodeling level of the mild and moderate asthma group was significantly higher than that of the control group. The airway remodeling level of the severe asthma group was significantly higher than that of the mild and moderate asthma group. Serum LXRα, LXRβ in asthma group were higher than those in the control group. The levels of LXRα and LXRβ in severe asthma were higher than those in mild and moderate asthma group. There was no significant correlation between LXRs and airway remodeling. The PPM1A level in mild and moderate asthma group was lower than that in the control group. The levels of PPM1A in severe asthma were lower than that in mild and moderate asthma group. PPM1A level was negatively correlated with airway remodeling.ConclusionsThe level of PPM1A in asthma patients is lower than that in healthy subjects, and is negatively correlated with the degree of airway remodeling. Serum LXRs in asthmatic patients are higher than that in healthy subjects, but LXRs are not significantly correlated with airway remodeling.
