PURPOSE:To verify existance of a-,~-,and 3'-protein kinase C(PKC)subspecies and their localization in rabbit retina. METHODS: Using an immunohistoehemical technique with mono- elonal antibodies against PKC isozymes- I (a),-I[ (13),and -~[ (Y) to characterize the distribution of PKC in rabbit retina. RESULTS:There is a positive immunostaining for a-,13-,and ~-PKC in rabbit retina. The immunoreactivity of a-PKC was observed mainly in the bipolar cells of inner nuclear layer and the outer segments of photorecptors. The positive immunostaining of 13-PKC could be seen in the ganglion cells,inner plexiform layer,inner nuclear layer,and the outer segments of photoreceptors. A diffuse and weak staining of Y-PKC is recognized in the ganglion cell layer,inner plexifrom layer,inner nuclear layer, and the outer segments of photoreceptors. CONCLUSION:The protein kinase C sub- speeies-a,-~,and-'Y are present in retina which is a part of the central nervous system
Objective To clone the genes of nogo-66 and NEP1-40 from spinal cord of rat and to realize the expression of its protein in vitro. Methods The nogo-66 and NEP1-40 genes were cloned from the spinal cord of juvenil rat by use of RT-PCR techniques, and the objective genes were bonded to T vector through gene coupled action, recombinant plasmid were sequencing, and the genes were cloned into PQE30-GST vector, then the recombinant plasmids were induced by isopropylthiogalactoside(IPTG) to express the proteins. The two proteins were purified by Ni-column and detected by using Westernblot test. Results The Nogo-66 and NEP1-40 genes were successfully cloned from rat, which were 215 bp and 137 bp for each one when add the enzyme site. No gene mutations were detected in the two genes after sequencing. The expression plasmids were cut by the two enzyme (BamH Ⅰ and Hind Ⅲ), the target bands were seen on the results of electrophoresis. The expression plasmids were induced by IPTG and got the purified GST fusion protein nogo-66 and NEP1-40, which relative molecular weight were 33.2×103 and 30.3×103 respectively. The results of Westernblot test confirmed that the antigenicity of the two proteins was precise. Conclusion Nogo-66 and NEP1-40 proteins can be expressed in a high efficiency in vitro using genetic engineering, so it provides a good basis for further research on its function and vaccine for spinal injury.
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.
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.
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)
Objective To investigate the role of ephrin A genes in the development of oxygen induced retinalneovascularization (OIR) in mice.Methods The OIR model was established by oxygen induction in new born C57BL/6J mice.Reversed transcript polymerase chain reaction (RT-PCR) was used to measure the expression levels of ephrin A1-A5 in retinas of mice in experimental and normal control group.Results All of the ephrin A family genes expressed in normal retinas. Ephrin A1 mRNA was significantly higher in OIR group(t=3.19,P=0.019); ephrin A2 mRNA was higher in the 15-day-old OIR retinas(t=3.71,P=0.033）; ephrin A3-A5 mRNA decreased or disappeared in 12 and 13-day-old RNV mice, and increased in 15-day-old OIR mice. Conclusion Ephrin A genes are involved in the development of retina and OIR.
Objective To separate each protein band from the nerve regeneration conditioned fluid(NRCF）and to study whether there are somenew and unknown neurotrophic factors in the protein bands with a relative molecular mass of 220×103. Methods The silicone nerve regenerationchambers were formed in the sciatic nerve of the 25 New Zealand rabbits (weight,1.8-2.5 kg), and NRCF was taken from it at 1 week after operation. The Nativepolyacrylamide gel electrophoresis (Native-PAGE) was used for separating the proteins from NRCF and detecting the relative molecular mass. The Western blot and ELISA were used to observe whether the protein bands ［220×103 (Band a), (20-40)×103(Band c)］ of NRCF could combine with the antibody of the known antibody of neurotrophic factor (NTF):nerve growth factor(NGF), glial cell-derived neurotrophic factor(GDNF), brainderived neurotrophic factor(BDNF), neurotrophin 3(NT-3)， NT-4, ciliang neurotrophic factor(CNTF). Results Separated by Native-PAGE, NRCF mainly contained two protein bands:Band a had a relative molecular mass about 220×103, and Band c had a relative molecular mass about (20-40)×103. Band a could not combine with the antibodies of the NGF, BDNF, CNTF, and NT-3, but could combine with the antibody of NT-4.Band c could combine with the antibodies of NGF, BDNF, CNTF and NT-3, but could not combine with the antibodies of NT-4 and GDNF. Conclusion The protein bands with a relative molecular mass of 220×103 have ber neurotropic and neurotrophic effects than the protein bands with a relative molecular mass of (20-40)×103, which contains NGF,CNTF, etc. NT-4 just has a weak or no effect on the sympathetic neurone. This indicates that there is a new NTF in the protein bands with a relative molecular mass of 220×103, which only combines with the antibody of NT-4.
Objective To find a new specific marker that can be used to early diagnose hepatic fibrosis by detecting the change of serum protein in patients with hepatic fibrosis. Methods This research adopted 50 SD rats (25 males and 25 females), and from which 6 rats were selected randomly (3 males and 3 females) as control group, last 44 rates were divided into four groups according to four pathological stages as hepatic fibrosis model group (experimental group). Distinct proteins in serum were detected by surface-enhanced laser desorption/ionization-time of flight-mass spectra (SELDI-TOF-MS). Radioimmunoassay was used to measure four parameters of hepatic fibrosis which were hyaluronidase (HA), precollagen Ⅲ (PCⅢ), laminin (LN) and collagen Ⅳ (Ⅳ-C). Results Distinct proteins in serum were detected in 8 cases of stage Ⅰ of hapatic fibrosis, 5 cases of stage Ⅱ, 5 cases of stage Ⅲ, 6 cases of stage Ⅳ, and 5 cases of control by SELDI-TOF-MS. Three protein peaks were found (M/Z: 4 203, 4 658, and 7 400). The peaks of M/Z 4 658 and 4 700 proteins were obviously increased in the stage Ⅰ of hepatic fibrosis （Plt;0.05）, while the changes of hepatic fibrosis four parameters appeared in stage Ⅳ of hepatic fibrosis. Conclusion This method shows great potential for early diagnosing of hepatic fibrosis and finding better biomarkers to hepatic fibrosis.
Mutations in the BEST1 gene are associated with a range of retinal diseases collectively referred to as "Best diseases", including Best vitelline macular dystrophy. More than 300 mutations at different sites of the BEST1 gene have been found, which may cause a series of functional disorders such as the mistransport of the calcium-activated anion channel protein-1 protein encoded by it, protein oligomerization defects, and abnormal anion channel activity, leading to different clinical phenotypes. Although it has been established that the BEST1 gene mutation is associated with at least one different type of Best disease, the relationship between the specific gene mutation site and the specific clinical phenotype has not been fully defined. For the time being. Drugs and gene therapy for the Best diseases are still in the basic research stage, which provides a broad development space for future treatment exploration. In the future, when selecting gene therapy in clinical applications, it is necessary to combine the clinical phenotype and molecular diagnosis of patients, and clearly define their mutation types and pathogenic mechanisms in order to achieve better personalized treatment effects.
Objective To observe the effect of high glucose on the expression of activating transcription factor 4 (ATF4) in cultured retinal Muuml;ller glia cells. Methods The retinal tissue of Sprague-Dawley (SD) rats was collected, and Muuml;ller cells were isolated and cultured. The glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS) of Muuml;ller cells were identified by streptavidin-biotin-peroxidase complex. Cultured rat Muuml;ller cells were divided into control group (5.5 mmol/L glucose), group A (20 mmol/L glucose), group B (30 mmol/L glucose) and group C (40 mmol/L glucose). ATF4 protein expressions in Muuml;ller cells of four groups were measured by Western blot four days after cultured. Results GFAP and GS expressed in more than 95% of Muuml;ller cells. Over 95% of Muuml;ller cells of group A, B and C were positive for GFAP and GS. Western blots indicated that ATF4 protein in group A, B and C increased obviously compared with the control group (q=0.293, 0.754,0.484;P＜0.05). Conclusion High glucose can increase the expression of ATF4 protein and cause endoplasmic reticulum stress in retinal Muuml;ller glia cells in vitro.