Objective To analyze the protective effects of heat-shock response on the retinae of the rats after retinal ischemic reperfusion injury.Method Twenty Wistar rats (20 eyes) were divided into 4 groups: intracameral perfusion group (group P), intracameral perfusion after quercetin injection group (group P+Q), intracameral perfusion after heat shock group (group P+H), and in tracameral perfusion after quercetin injection and heat shock group (group P+Q+H ). According to the standard program established by International Society for Clinical Visual Electrophysiology, we recorded the results of the dark-adapted electroretinogram (D-ERG ),oscillatory potentials (OPs),and light-adapted ERG (L-ERG) of the rats with intraocular hypertension after induced by heat shock response. The expressions of HSP 70 of the rats in all groups were observed by Western blotting.Results The expression of HSP 70 of the rats in group P+H was the highest in all groups, but the expressions of HSP70 in group P+Q and P+Q+H were inhibited significantly. The amplitudes of a and b wave of ERG and O2 wave of OPs decreased, and the delitescence of them were delayed significantly in rats after intracameral perfusion. The amplitude of b wave of D-ERG and O2 wave of OPs in group P+H were higher than which in group P. Zero hour after perfusion, the amplitudes of all waves in group P+H increased significantly (Plt;0.05). Twenty-four hours after perfusion, the retinal functional resumption of the rats in group P+H was better than which in group P. In group P+Q and P+Q+H, the delitescences of all waves of ERG and O2 wave of OPs were the longest and the amplitudes were the lowest, and some waves even disappeared.Conclusions The heat-shock response may improve the recovery ability of the retinal cells after injury of ischemic reperfusion.(Chin J Ocul Fundus Dis，2003，19：117-120)
ObjectiveTo observe the expression of heat shock protein 47 (HSP47) and transforming growth factor-β2(TGF-β2) in vitreous specimens and epiretinal membranes of patients with proliferative vitreoretinopathy diseases. MethodsVitreous specimens and epiretinal membranes were obtained from 48 patients (48 eyes) with proliferative vitreoretinopathy (PVR) and 50 patients (50 eyes) with proliferative diabetic retinopathy (PDR). Vitreous specimens and internal limiting membranes were collected from 20 patients (20 eyes) with idiopathic macular hole (IMH) as control group. The expression of HSP47 and TGF-β2 in the vitreous specimens was evaluated using enzyme linked immunosorbent assay. The expression of HSP47, TGF-β2, typesⅠandⅢcollagen in epiretinal membrane and internal limiting membrane specimens were observed for immunohistochemical staining method. The correlation between the positive expression of HSP47 and TGF-β2, typesⅠandⅢcollagen in epiretinal membrane specimens of patients with PVR and PDR were analyzed. ResultsThe expression of HSP47 in vitreous specimens of patients with PVR, PDR and IMH were (212.35±23.32), (231.30±26.79), (171.06±28.91) pg/ml, respectively. The expression of TGF-β2 in vitreous specimens of patients with PVR, PDR and IMH were (1919.96±318.55), (1939.39±177.57), (1194.61±234.20) pg/ml, respectively. The expression of HSP47, TGF-β2 in the vitreous specimens of patients with PVR and PDR were significantly increased compared with patients with IMH and the difference was statistically significant (F=12.952, 34.532;P < 0.01). The epiretinal membrane of patients with PVR and PDR showed markedly increased expression of HSP47, TGF-β2, typesⅠandⅢcollagen in the cytoplasm and extracellular matrix. The expression of HSP47 and typeⅢcollagen was negative and the expression of TGF-β2 was weakly positive and the expression of typesⅠcollagen was positive in internal limiting membrane of patients with IMH. The expression of HSP47, TGF-β2, typesⅠandⅢcollagen in the epiretinal membrane of patients with PVR and PDR were significantly increased compared with patients with IMH and the difference was statistically significant (F=13.469, 18.752, 12.875, 20.358; P < 0.01). The expression of HSP47 was positively correlated with the positive expression of TGF-β2, typesⅠandⅢcollagen in epiretinal membrane specimens of patients with PVR (r=0.475, 0.556, 0.468; P < 0.05) and PDR (r=0.484, 0.589, 0.512; P < 0.05). ConclusionsThis study showed increased consistent expression of HSP47 and TGF-β2 in vitreous and epiretinal membrane specimens of patients with PVR and PDR. Both HSP47 and TGF-β2 were expressed in the cytoplasm and extracellular matrix. HSP47 and TGF-β2 may be involved in the pathological process of PDR and PVR by promoting collagen synthesis.
Objective To investigate the expression of induced heat shock protein (HSP) 70 in ratprime;s retinal neurons (RNs) and Muuml;ller cells, and evaluate the protective effect of HSP 70 on RNs injured with glucose deprivation and glutamate. Methods Ratprime;s RNs and Muuml;ller cells cultured in vitro were treated with heat shock (42℃ for 1 hour), and duration of the expression of HSP70 was detected by immunocytochemical techniques. Viability of the cells was measured by methyl thiazolyl tetrazolium (MTT) chromatometry after incitant toxic injury with glucose deprivation (0.56 mmol/L glucose for 6 hours) and glutamate (100 mu;mol/L for 6 hours). Simultaneously, the expression was interdicted by HSP70. Results Hypereffective expression of HSP70 was found in cultured RNs and Muuml;ller cells after heat shock. The viability of RNs pretreated by heat shock after injured with glucose deprivation and glutamate significantly increased which could be interdicted by HSP70 antibody. Conclusion Hypereffective expression of HSP 70 may be induced by heat shock, which enhances the ability of tolerance of RNs to the incitant toxic injury by glucose deprivation and exitotoxicity. (Chin J Ocul Fundus Dis, 2005,21:110-113)
ObjectiveTo investigate the effect of heat shock protein B8 (HspB8) downregulation on retinal ganglion cell (RGC) and retinal function in the mice model of optic nerve injury (ONC).MethodsAdeno-Associated Virus (AAV) 2 AAV2-shHspB8-GFP was constructed to knockdown HspB8. 66 adult male C57/BL6 mice were randomly divided into the control group, the ONC group, the AAV2-shHspB8 group, the ONC+AAV2-shHspB8 group, and the ONC+AAV2- GFP group. There were 10, 20, 16, 10 and 10 mice respectively, and both eyes were used as experimental eyes. Western blot was used to evaluate the expression of HspB8 on day 3 and 7 after ONC. By GFP immunofluorescence staining, the efficacy of AAV2-shHspB8-GFP transfer was accessed. Moreover, it was possible to identify functional and RGC survival differences between groups by optomotor response (OMR), dark adapted full-field flash electroretinogram (ff-ERG), oscillatory potentials (OPs), photopic negative response (PhNR) and retinal flat-mount RGC counting 5 days after ONC. Comparisons between two groups were made using Mann-Whitney U test, unpaired t-test, unpaired t-test with Welch’s correction, one-way ANOVA, and Bonferroni t test.ResultsCompared with the control group, the expression of HSPB8 protein in the retina of mice in ONC3 group was significantly increased, and the difference was statistically significant (F=43.63, P＜0.01). Compared with the control group, the ONC group showed obviously lower visual acuity (P＜0.01), lower a-wave, b-wave, OPs, PhNR amplitude, longer b-wave latency (P＜0.05), and the survival rates of RGC in ONC3 group, ONC5 group and ONC7 group decreased in a time-dependent manner(F=384.90, P＜0.01). Transfection of AAV2 efficiency was highest on 4 weeks after IVT. Besides, there was no significant differences between the control group and the AAV2-shHspB8 group on visual acuity, ff-ERG, OPs, PhNR and RGC survival (P>0.05). In comparison of the control group, we found that RGC survival of the ONC5+AAV2-shHspB8 group was significantly elevated (F=10.62, P＜0.01).ConclusionsExpression of HspB8 on the retina can be induced by ONC. The investigation of RGC counting, visual acuity, and ff-ERG revealed that optic nerve injury destructed functionality of mice retina and resulted to RGC death ultimately. The Most crucial finding of this research is that HspB8 knockdown had a neuroprotective effect in RGC after ONC.
ObjectiveTo observe the expression of hot shock protein 47 (HSP47) in pre-retinal membrane of proliferative vitreoretinopathy (PVR) and the influence of transforming growth factor-β2 (TGF-β2) on the expression of HSP47 in retinal pigment epithelial (RPE) cell. MethodsPre-retinal membranes were collected and observed by hematoxylin-eosin, Masson and immunohistochemical staining. Cultured ARPE-19 cells were treated with TGF-β2 at serial concentration (0, 1, 5, 10 ng/ml) and time (0, 12, 24, 48 hours), respectively. And then the mRNA and protein expressions of HSP47 and Col-Ⅰ were measured by fluorescence quantitative reverse transcription polymerase chain reaction and Western blot at the same time. ResultsA lot of epithelial cells with pigmental particles were observed in pre-retinal membranes of PVR, much accumulated collagen protein was observed in the specimens, and HSP47 positive expression was bserved in cytoplasm and stroma of most of the epithelioid cells. Compared with 0 ng/ml group, the expressions of HSP47 mRNA in ARPE-19 were up-regulated by 1.32, 2.35, 1.85 fold, significant differences were observed in all groups (F=27.21, P<0.05); the expressions of protein were up-regulated by 2.33, 2.89, 2.60 fold, significant differences were observed in all groups (F=39.78, P<0.05). The expressions of Col-Ⅰ mRNA were up-regulated by 1.29, 1.52, 2.11 fold, significant differences were observed in all groups (F=23.45, P<0.05); the expressions of protein were up-regulated by 1.18, 1.49, 2.11 fold and significant differences were observed in all groups (F=29.10, P<0.05). Compared with 0 hour group, the expressions of HSP47 mRNA were up-regulated by 1.56, 1.84, 2.86 fold in ARPE-19 cells stimulated by 5 ng/ml TGF-β2 for 12, 24 and 48 hours, and the differences were all significant (F=31.56, P<0.05); the expressions of protein were up-regulated by 2.08, 2.37, 2.80 fold, and the differences were all significant (F=49.18, P<0.05). The expressions of Col-Ⅰ mRNA were up-regulated by 1.57, 1.86, 2.78 fold and the differences were all significant (F=54.43, P<0.05), the expressions of protein were up-regulated by 1.38, 1.59, 2.16 fold and the differences were all significant (F=42.52, P<0.05). ConclusionTGF-β2 may play a role in the pathologic process of PVR by promoting the expression of HSP47 and then increasing the synthesis and accumulation of Col-Ⅰ.
ObjectiveTo observe the influence of heat shock protein 27 (HSP27) sensibilization to retinal ganglion cells (RGC) apoptosis of rats. MethodsThirty-five female Wistar rats were randomly divided into HSP27 sensibilization group (15 rats), borate buffer solution (BBS) control group (15 rats) and normal group (5 rats). The rats in HSP27 sensibilization group were received hypodermic injection in rear limb with 100 μg HSP27 and complete freund adjuvant, intraperitoneal injection with 1 μg pertussis toxin. The BBS control group received the same volume of BBS at the same site. The normal group received no intervention. The intraocular pressure was measured 3 days before injection and 1, 2, 4, 6, 8 weeks after injection. Four, 6 and 8 weeks after injection, the retinal frozen sections was made to observe RGC apoptosis by terminal-deoxynucleoitidyl transferase mediated nick end labeling. The anti-HSP27 level in serum and cerebrospinal fluid were detected by enzyme linked immunosorbent assay. ResultsThere was no obvious change of intraocular pressure in rats in 3 groups before injection (P>0.05). RGC apoptosis was observed in HSP27 sensibilization group 4 weeks after injection, and increased significantly at 6 weeks after injection. There was no RGC apoptosis in BBS control group and normal group. The level of anti-HSP27 in serum and cerebrospinal fluid of HSP27 sensibilization group occurred at 4 and 6 weeks after injection respectively, decreased with prolongation of injection time. Compared with BBS control group and normal group, the RGC apoptosis rate, anti-HSP27 level in serum and cerebrospinal fluid of HSP27 sensibilization group were significantly increased (P<0.05). There was no significant difference of the RGC apoptosis rate, anti-HSP27 level in serum and cerebrospinal fluid between BBS control group and normal group (P>0.05). ConclusionsHSP27 sensibilization could promote the RGC apoptosis. The variation trend of anti-HSP27 level in cerebrospinal fluid is consistent with the RGC apoptosis.
Objective To observe the effects of basic fibroblast growth factor (bFGF) on the expression of heat shock protein 70 (HSP70) in ratrs retina after iscbemia/reperfusion injury.Methods The rat model of experimental retinal ischemia/reperfusion injury was made by increasing the intraocular pressure. Tweenty-four Wistar rats were divided into normal (3 rats) and operation group (21 rats) randomly. The latter group was subdivided into group 0 hour, 4, 8, 12, 24, 48 and 72 hours after reperfusion, in which the left eyes of the rats were in the ischemia/reperfusion groups and the right ones were in the treatment groups (bFGF 2 t~g intracameral injection). The expression of HSP70 was observed by strept avidin-biotin complex (SABC) immunohistochemistry. Results No HSP70 positive cells were found in normal group; a few of HSP70 positive cells were found 0 hour after reperfusion [20.8±4. 5) cells/mm2], and increased gradually until reached the peak 24 hours later [(111.2±4.4) cells/mm2] and then decreased gradually. Few HSP70 positive cells were found 72 hours after reperfusion. The amount of HSP70 positive cells increased in treatment group at all time courses, and the peak time was earlier and longer than that in ischemia group. HSP70 positive cells distributed extensively in retinal ganglion cell layer and inner nucleous layer. The difference of the amount of HSP70 positive cells between the two groups was significant (Plt;0.05) 8, 12, 24, 48 and 72 hours after reperfusion.Conclusion bFGF can enhance the expression of HSP70 in rat’s retina after retinal ischemia/reperfusion injury.(Chin J Ocul Fundus Dis，2004，20：37-39)