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Objective: To investigate the effect of nerve growth factor (NGF) on the expression level of growth differentiation factor-15 (GDF-15) in the brain tissue of the rats with cerebral infarction, and to elucidate the mechanism of NGF in the rats with cerebral infarction. Methods: The middle cerebral artery occlusion (MCAO) models were established by the Longa' s method. A total of 54 SD rats were randomly divided into sham operation group, model group and NGF group, and there were 18 rats in each group. The rats in NGF group were given NGF (50 μg middot; kg-1) by intraperitoneal injection, and equal volume of normal saline was given to the rats in sham operation (the artery was isolated without ligation) group and model group. The neurological function scores of the rats in various groups were measured 1, 3 and 7 d after operation; HE staining was used to observe the pathomorphology of nerves in brain tissue and immunohistochemical staining was used to detect the number of GDF-15 positive cells; the expression levels of GDF-15 in brain tissue of the rats in various groups were detected by ELISA method. Results: The results of HE staining showed that the degrees nerve cell necrosis, interstitial edema and glial cell proliferation were relatively low in NGF group 7 d after operation. Compared with sham operation group, the neurological function scores, the number of GDF-15 positive cells, and the expression levels of GDF-15 in brain tissue of the rats in model group and NGF group were significantly increased (P<0. 05). Compared with model group, the neurological function scores of the rats in NGF group were significantly decreased 3 and 7 d after operation (P<0. 05), and the number of GDF-15 positive cells and the expression levels of GDF-15 in brain tissue of the rats in NGF group were significantly increased at different time points after operation (P<0. 05). Conclusion: NGF can protect the brain nerve by up-regulating the expression level of GDF-15 in brain tissue and improving the nerve function.
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Objective: To construct the form deprivation myopia (FDM) rat models, and to elucidate the expression of transforming growth fact or-(21 CTGF-ß1 ) in scleral fibroblasts of the FDM rats and its relationship with Wnt/p-catenin signaling pathway. Methods: Forty rats were randomly divided into control group and FDM model group, with 20 rats in each group. The FDM rat model was established in FDM model group. The axial lengths of the rats were determined. The rat sclera tissue of eyeball was separated. The expression levels of TGF-ß1 protein and mRNA in sclera tissue of the rats were determined by Western blotting and reverse transcription-polymerase chain reaction CRT-PCR) methods. The scleral fibroblasts of rats were isolated and cultured. The fibroblasts in the sclera of the rats in control group were used as the control group. The fibroblasts in FDM model group were divided into FDM group and FDM+ Dickkopf related protein 1 (DDK1) group (added to DDK 1 to culture). The expression levels of TGF-ß1. Dicer-like 3 (DCL3)» colon adenomatous polyp protein CAPO, glycogen synthase kinase 30 (GSK3{3)» p21-GSK3j3. and {3-catenin protein and mRNA in scleral fibroblasts were determined by Western blotting and RT-PCR methods. Results: Compared with control group-the axial length of the rats in FDM group was increased (P0. 05) ; but there were significant differences in the expression levels of TGF-ß1, DC 1.3. APC. p21-GSK30. and p-catenin protein and mRNA in the scleral fibroblasts C P< 0.01). Compared with control group, the expression levels of TGF-ß1 and APC protein and mRNA in scleral fibroblasts of the rats in FDM group were decreased (P<.0. 01). and the expression levels of DCL3» p21-GSK3(3. and (3-catenin protein and mRNA were increased ( P<0. 05). Compared with FDM group, the expression levels of TGF-ß1 and APC protein and mRNA in the scleral fibroblasts of the rats in FDM+DDK1 group were increased CP<0. 01). and the expression levels of DCL3. p21-GSK3,3. and 0-catenin protein and mRNA were decreased ( P< 0. 01). Conclusion: The expression level of TGF-,ß1 in the scleral fibroblasts of the FDM model rats is decreased, and its level is regulated by the Wnt. p-catenin signaling pathway.
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Background The pathogenesis of diabetic retinopathy (DR) involves a variety of biological pathways.Recently,inflammation factor has been thought to paly an important role in the pathogenesis of DR.Studies show that the concent of tumor necrosis factor-α (TNF-α) is increased in high-glucose environment,which leads to the abnormality of tight junction protein and follows by blood-retinal barrier (BRB) damage.Polysaccharides of dendrobium candidum (PDC) can inhibit the overexpression of TNF-α,but its effect on TNF-α in early DR procedure has been unelucidated.Objective This study was to investigate the effects of PDC on permeability of BRB and its mechanism in daibetic rats.Methods Fifty clear adult SD rats were divided into normal control group,diabetic model group and low-(100 mg/[kg · d]),moderate-(200 mg/[kg · d]) and high-dose (300 mg/[kg · d]) PDC groups,10 rats for each group.Streptozotocin was intraperitoneally injected to establish diabetic model in 40 rats,expect for normal control group.PDC at the concentrations of 100,200 and 300 mg/(kg · d) was intragastrically administered in the low-,moderate-and high-dose groups respectively at 6 weeks after modeling,and normal saline solution was used at the same way in the normal control group and diabetic model group.Evans blue was perfused via cardic chamber and eyes were obtained.Evants blue leakage was measured to evaluate the BRB permeability.The relative expressions of TNF-α,zonula occludens-1 (ZO-1),occludin and claudin-5 proteins were detected by Western blot;TNF-α contents in the retina and serum of the rats were detected by ELISA.Results The leakage concents of Evans blue in the retinas were (12.68±1.30),(30.45±2.60),(22.12±1.15),(17.99±1.00) and (21.49±1.00) in the normal control group,diabetic model goup and low-,moderate-and high-dose PDC groups,respectively,and the retinal leakage concents in the diabetic model group were significantly higher than those in the normal control group,and the retinal leakage contents in the low-,moderate-and high-dose PDC groups were lower than those in the diabetic model group (all at P ＜ 0.01).Western blot showed that the relative expression level of retinal TNF-α was significantly higher in the diabetic model group compared with the normal control group(1.12±0.10 vs.0.27±0.03),and that in the diabetic model group was significantly higher than that in the normal control group;while the relative expression levels of retinal TNF-α in different doses PDC groups were significantly lower,and the relative expression levels of retinal ZO-1,occludin and claudin-5 were significantly higher than those in the diabetic model group (all at P＜0.05).ELISA showed that the concentrations of retinal and serum TNF-α were higher in the diabetic model group compared with the normal control group,and those in the different doses of PDC groups were lower than those in the diabetic model group (all at P＜0.05).No significant differences were found among various doses of PDC groups (all at P＞0.05).Conclusions PDC can improve the permeability of BRB by down-regulating the expression of TNF-α and up-regulating the expressions of tight junction proteins in the retina of diabetic rats,which is probably related to suppressing the development of early DR.
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Background The pathogenesis mechanism of diabetic cataract has not been fully elucidated.Researches showed that multiple biological pathways participate in the pathogenesis of diabetic cataract,including oxidative stress.Astaxanthin can inhibit oxidative stress-mediated injury and lipid peroxidation.However,whether astaxanthin has the preventive effects on diabetic cataract is unclear.Objective This study was to investigate the preventive effects of astaxanthin on metabolic cataract in type 1 diabetic rats.Methods Thirty-eight 6-week-old SPF male SD rats were used in this study,and 1％ streptozocin was intraperitoneally injected to establish type 1 diabetic models in 30 rats,and 24 successful models were assigned to diabetic model group,low-dose astaxanthin group and high-dose astaxanthin group.Equal volume of normal saline solution was injected in the same way in 8 rats as the normal control group.Mixture foods containing 50 mg/(kg · day) or 100 mg/(kg · day) astaxanthin with olive oil and fodder were used continuously for 3 months in the rats of low-dose astaxanthin group and high-dose astaxanthin group,respectively,and mixture food of olive oil with fodder was used in the diabetic model group.Only fodder was used in the same way in the rats of the normal control group.The opacification of lens was examined by slit lamp section radiography system and graded on a scale of 1-5.The specimen of lens were prepared for the hematoxylin & eosin stain.The expression and lation of advanced glycosylation end products (AGEs) in the lens was examined using immunochemistry.The contents of oxidative stress-related indicators in the lens,such as AGEs,malonydialdehyde (MDA),catalase (CAT),superoxide dismutase (SOD) and mass fraction of glutathione (GSH),were assayed by ELISA.The experimental process complied with the national standard (Laboratory Animal Requirements of Environment and Housing Facilities [GB14925-2001]).Results The blood glucose levels of the rats were significantly higher in the diabetic model group,low-dose astaxanthin group and high-dose astaxanthin group than those in the normal control group at 2,4,6,8,10 and 12 weeks after modeling (all at P＜0.05),while the blood glucose levels of rats were not evidently different between low-dose astaxanthin group and high-dose astaxanthin group at various time points(all at P＞0.05).The rat lenses were transparent in the normal control group with scale of grade 1,and serious lens opacification was seen in the rats of the diabatic model group,with the scale of grade 5,while the rat lenses in the low-dose astaxanthin group and high-dose astaxanthin group were in grade 3-4.The contents of AGEs in the lenses were (7.23 ±0.50) μg/ml and (7.01 ±0.37) μg/ml,and M DA contents were (1.43 ± 0.22) mmol/L and (1.35±0.16)mmol/L in the low-dose astaxanthin group and high-dose astaxanthin group respectively,which were significantly lower than (7.61± 0.45) μg/ml and (1.62 ±0.42) mmol/L in the normal control group (all at P＜0.05).GSH contents in rat lenes were (272.70±12.53) ng/L and (283.52±16.17) ng/L,and SOD coneents were (55.45± 6.47) μmol/(min · L) and (56.73±5.12) μmol/(min · L),and CAT concents were (2.91 ±0.41) μmol/(min · L)and (3.02±0.13)μmol/ (min · L) in the low-dose astaxanthin group and high-dose astaxanthin group respectively,which were significantly higher than (241.52 ± 15.13) ng/L,(51.67 ± 5.45) μmol/(min · L) and (2.72 ± 0.27)μmol/(min · L) in the normal control group (all at P＜0.05).The GSH concent and SOD concent in rat lens were lower in the low-dose astaxanthin group than that in the high-dose astaxanthin group (both at P＜0.05).Conclusions Astaxanthin can postpone the pathogenesis and development of diabetic cataract in type 1 diabetic rats by antioxydative stress.
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Background Studies showed that inflammation is associated with the pathogenesis and development of dry eyes,and tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) are key inflammatory factors.Thymosin β4 (Tβ4) plays a promoting effect on the migration of epithelial cells and anti-inflammatory action.However,the influences of Tβ4 on the repair of ocular surface in dry eyes are unelucidated.Objective This study was to investigate the regulation of Tβ4 to the expressions of TNF-o and IFN-γand its effect on the recovery of ocular surface in rat dry eye models.Methods The dry eye models were induced by topically administered of benzalkonium chloride (BAC) for consecutive 7 days in the left eyes of 50 SPF male SD rats,and 36 successful models were used in the experiment.Tβ4 solution (9 μg/ml),recombinant human epithelial growth factor (rhEGF)and sterile PBS at 5 μl was topically administered three times for consecutive 7 days in the Tβ4 group,rhEGF group and PBS group,and no drug was used in the model control group.The normal right eyes of rats served as the normal control group.The break-up time of tear film (BUT),corneal fluorescein staining score and Schirmer Ⅰ test (S I t)were examined and evaluated in the rats on the seventh day after administration of drugs.Then the rats were sacrificed by excessive anesthesia and the sections of the ocular surface were prepared.The morphology of the specimens was examined by hematoxylin and eosin staining,and the number of conjunctival gobelt cells was counted by periodic acidschiff staining.The ultrastructure of the corneal and conjunctival cells was examined under the transmission electron microscope.The expressions of TNF-α mRNA and IFN-γ mRNA and their proteins in conjunctiva tissue were quantified by quantitative real-time PCR and Western blot,respectively.The use and care of the animals followed by Regulation for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.Results The BUT was (10.42±0.66),(7.46±0.49),(8.71±0.50),(9.59±0.35) and (8.63± 0.68) seconds in the normal control group,model control group,rhEGF group,Tβ4 group and BUT group,showing a significant difference among the groups (F =5.65,P =0.00),and the BUT was evidently shortened in the model control group compared with the normal control group,while the BUT was significantly extended in the rhEGF group and Tβ4 group in comparison with the model control group (all at P＜0.05).No significant differences were found in the corneal fluorescence score and S I t among the groups (F =0.42,P =0.79;F =136.77,P =0.00).The corneal and conjunctival epithelium defect and corneal stromal edema were seen in the model control group,and the proliferation of the epithelial cells were found in the rhEGF group and Tβ4 group,with the irregulated arrangement of the cells.A considerable difference was seen in the number of conjunetival goblet cells among the groups (F=3.16,P =0.04),and the number of eonjunctival goblet cells in the rhEGF group and model control group was significantly less than that in the normal control group (all at P＜0.05),and no statistically significant difference was seen between Tβ4 group and normal control group (P ＞ 0.05).The swelling,mergence,crispation,rupture and decrease of the microvilli and micro fold were found in the model control group,and the repair of the cell microvilli was seen in the Tβ4 group.The expressions of the TNF-α mRNA,IFN-γ mRNA and their proteins in the conjunctiva were significantly different among the groups (F =43.08,371.69,34.27,43.52,all at P =0.00),the expressions of the inflammatory factors were significantly higher in the model control group compared with the normal control group,and these expressions were evidently lower in the Tβ4 group in comparison with the model control group and rhEGF group (all at P＜0.05).Conclusions The topical administration of Tβ4 solution can promote the repair of ocular surface by down-regulating the expression of TNF-α and IFN-γ in conjunctiva and stablize the tear film in rat dry eyes.