ObjectiveTo evaluate the protective effect of estrogen on survival of retinal ganglion cells (RGCs) after transient retinal ischemia-reperfusion (RIR) in rats.MethodsRIR was induced in 60 ovariectomized adult rats (OVX) by increasing intraocular pressure via an intracameral catheter. All of the rats were divided into two groups randomly: in experimental group, the rats underwent a subcutaneous injection with 17β-estrodiol（100 μg/kg） 2 hours before retinal ischemia; and in the control group, saline water was injected correspondingly. The number of RGCs and the thickness of the inner retinal layers were mesured by HE staining method before and 12, 24, 48, and 72 hours after reperfusion. TdT-mediated biotin-dUTP nick end labelling (TUNEL) staining technique was used to examine the apoptosis of RGCs.ResultsTwenty-four and 48 hours after reperfusion, the number of apoptotic cells in experimental group was obvious lower than that in the control group(Plt;0.05), and the number of RGCs in experimental group was higher than that in the control group(Plt;0.05).ConclusionEstrogen can protect retinal neurons from transient RIR in ovariectomized rats.(Chin J Ocul Fundus Dis, 2005,21:177-179)
ObjectiveTo observe the effect of Crocin on structure and the expression of tumor necrosis factor-alpha; (TNF-alpha;) and interleukin-1beta; (IL-1beta;) in rat retina after injury by ischemia-reperfusion. Methods A total of 80 Sprague-Dawley male rats at the age of 8 -10 weeks were divided into control group, model group, low-dose Crocin group and high-dose Crocin group, with 20 rats in each group. The rats of control group were not treated. The rats in model, low-dose Crocin and high-dose Crocin group were induced with normal saline by anterior chamber perfusion creating a retinal ischemia-reperfusion (RIR) model. The rats of the low-dose Crocin and highdose Crocin group received intraperitoneal injection with different doses of Crocin solution (5 mg/kg, or 50 mg/kg) 30 minutes prior to ischemic injury and one time per day after successful RIR. Optical microscopy was used to observe the retinal structure. Enzymelinked immunosorbent assay (ELISA) was used to measure the expression of TNF-alpha; and IL-1beta; 6, 12, 24 and 48 hours after RIR. ResultsThe retinal structure of control group was normal. Pathological changes were found in the RIR model and low-dose Crocin group, such as retinal edema, disorganized structure and loosely packed cells. The degree of pathological changes in lowdose Crocin group was less than the RIR model group. The retinal structure of high-dose Crocin group was similar to the control group. The expression of TNF-alpha; was the highest at 24 hours after modeling, while the expression of IL-1beta; was the highest at 12 and 48 hours after RIR modeling. Six, 12, 24 and 48 hours after RIR modeling, compared with the control group, the TNF-alpha; expression of model (t=5.42, 7.94, 9.32, 9.18;P＜0.05 ), low-dose Crocin (t=3.94, 4.12, 4.98, 3.84;P＜0.05) and high-dose Crocin group (t=2.13, 2.34, 2.96, 2.78;P＞0.05) were increased. Compared with the RIR model group, the TNF-alpha; expression of low-dose Crocin (t=3.95, 4.56, 4.01, 5.12) and high-dose Crocin group (t=5.23, 7.65, 7.74, 7.63) was decreased. Compared with the control group, the IL-1beta; expression of model (t=7.23, 7.87, 7.15, 15.60), low-dose Crocin (t=5.65, 5.10, 5.54, 6.87;P＜0.05) and high-dose Crocin group (t=4.38, 5.21, 4.56, 4.75) was increased (P＜0.05). Compared with the model group, the IL-1beta; expression of low.dose Crocin group was decreased significantly 48 hours after RIR modeling (t=7.56,P＜0.05); but it decreased significantly at each time point in high-dose Crocin group (t=6.94, 5.36, 6.05, 10.50;P＜0.05). Conclusion Crocin can improve the retinal pathologic changes, while down-regulating TNF-alpha; and IL-1beta; expression in RIR rats.
Objective To investigate the effects of different reperfusion sequence on hepatic warm ischemia-reperfusion injury and its related mechanisms. Methods Ninety-six healthy male Sprague Dawley rats were randomly divided into 6 groups by using random digits method (n=16, each)： Sham operation group, only shammed operation for negative control; the other 5 groups were all experimental groups, which were divided according to different reperfusion sequences of portal vein and hepatic artery: reperfusion first through the portal vein for 1 min with subsequent full reperfusion group, reperfusion first through the portal vein for 2 min with subsequent full reperfusion group, reperfusion first through the hepatic artery for 1 min with subsequent full reperfusion group, reperfusion first through the hepatic artery for 2 min with subsequent full reperfusion group, simultaneous reperfusion through the portal vein and hepatic artery group. Each group was further randomly divided into two subgroups (n=8, each) for sample collection at 2, 4 hours after reperfusion respectively. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and malondialdehyde (MDA), superoxide dismutase (SOD) and glutathion (GSH) in hepatic tissue were detected respectively. HE staining of histopathologic slides was used to observe the morphological changes of hepatic tissue. TUNEL method was used to assess the apoptosis index (AI) of hepatocytes. Results The liver of rat was approximately normal in the sham operation group with lower levels of ALT, AST, MDA and AI, and higher levels of SOD and GSH as compared with all the experimental groups (P＜0.01). Less hepatic ischemia-reperfusion injury was found in reperfusion first through the portal vein for 1 min with subsequent full reperfusion group, whose ALT, AST, MDA and AI levels were significantly lower than those of the other experimental groups (P＜0.05 or P＜0.01), and its SOD and GSH levels were higher than those of the other experimental groups (P＜0.05 or P＜0.01). HE staining also showed milder hepatic injury in reperfusion first through the portal vein for 1 min with subsequent full reperfusion group as compared with the other experimental groups. Conclusion Hepatic reperfusion first through portal vein for short time with subsequent full reperfusion could depress the synthesis of free oxygen radicals and suppress apoptosis of hepatocytes, thus relieving hepatic ischemia-reperfusion injury.
Abstract： Objective To investigating the variance of nuclear factorkappa B（NF-κB）,inflammatory factor and polymorphonuclear cells(PMNs) in lung， our study infer the role of PMNs infiltration and early activity of NF-κB in empirical study of lung injury in deep hypothermia and circulatory arrest. Our study also guess the possible mechanism of action in order to provide a more excellent program for lung protection. Methods Twelve immature pigs were randomly divided into two groups，there are six pigs in each group，one group was normothermic parallel circulation(control group)，the other was deep hypothermia and circulatory arrest(DHCA, experimental group)，we obtain lung tissue and venous blood from pigs to measure the variances of NF-κB by immunohistochemistry and inflammatory factor by enzymelinked immunosorbent assay(ELISA) at different time. Results The expression of NF-κB of the lung tissue specimen was negative before parallel circulation in both groups, there was no brown dyed cell nucleus and the variation was no statistically difference in two groups. The expression of NF-κB reached it‘s peak at half an hour of ischemia reperfusion, and most of the brown dyed cell nucleus were PMNs, then the expression of NF-κB decreased in the experimental group. The lung tissue specimens were all weakly negative at the time points after parallel circulation and there was no statistical difference among them. But the content of inflammatory factor increased gradually from half an hour of ischemia reperfusion to two hour of ischemia reperfusion， which reached their peak at two hour of ischemia reperfusion.There was significance variances at the content of tumor necrosis factor-α(TNF-α) at one hour of ischemia reperfusion， while at one and a half hour of ischemia reperfusion. There was significance variance at the content of interleukin-8 and interleukin-6 in the experimental group. While in the control group, there was statistically difference before and after parallel circulation, but there was no statistically difference among the time points after parallel circulation. Conclusion The early activity of NF-κB may have an important role in lung injury of DHCA，treatments aim directly at NF-κB may provide an important strategy for lung injury of DHCA.
ObjectiveTo dynamically observe the effect of N-acetylserotonin (NAS) on the expression of tumor necrosis factor-α (TNF-α) protein in retina of retinal ischemia reperfusion injury (RIRI) rats, and to explore the mechanism.MethodsBy using random number table method, 90 healthy male Sprague-Dawley rats were divided into sham operation group (n=10), RIRI group (n=40), and NAS group (n=40). The right eye was as the experimental eye. In the RIRI group and NAS group, the anterior chamber high intraocular pressure method was used to establish the RIRI model. In the NAS group, 10 mg/kg NAS was injected intraperitoneally before modeling and 30 minutes after modeling. At 6, 12, 24, 72 h after modeling, hematoxylin-eosin staining was used to observe the pathological changes of the retina, and the retinal ganglion cells (RGC) were counted. Each group was detected by immunohistochemical staining and Western blot about the relative expression of TNF-α, nuclear factor E2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) protein in the rat retina. One-way analysis of variance was used for differences between groups. The general linear regression method was used to analyze the correlation between the relative expression changes of TNF-α protein and the changes of Nrf2 and HO-1 protein expression after NAS intervention.ResultsOptical microscope observation revealed that the retinal edema of rats in the RIRI group was observed at 6, 12, and 24 h after modeling; the thickness of the retina in the NAS group was significantly thinner than that in the RIRI group, and the difference was statistically significant (F=9.645, 477.150, 2.432; P＜0.01). At 6, 12, 24, and 72 h after modeling, the retinal RGC counts in the NAS group were significantly higher than those in the RIRI group, and the difference was statistically significant (F=12.225, 12.848, 117.655, 306.394; P＜0.05). The results of immunohistochemical staining and Western blot showed that 6 h after modeling, the relative expression of TNF-α protein in the retina of the RIRI group increased significantly compared with that in the sham operation group, reaching a higher level at 12 h, and decreased at 24 and 72 h. But all were significantly higher than the sham operation group, the difference was statistically significant (immunohistochemical staining: F=105.893, 1 356.076, 434.026, 337.351; P＜0.01; Western blot: F=92.906, 534.948, 327.600, 385.324; P＜0.01). At different time points after modeling, the relative expression of TNF-α protein in the retina of the NAS group was significantly lower than that of the RIRI group (immunohistochemical staining: F=15.408, 570.482, 21.070, 13.767; P＜0.05; Western blot: F=12.618, 115.735, 13.176, 111.108; P＜0.05), but still higher than the sham operation group (immunohistochemical staining: F=40.709, 151.032, 156.321, 216.035; P＜0.01; Western blot: F=33.943, 79.729, 74.057, 64.488; P＜0.01), the difference was statistically significant; 12 h after modeling, Nrf2 in the retina of the NAS group (immunohistochemical staining: F=51.122, P＜0.05; Western blot: F=33.972, P＜0.05), HO-1 (immunohistochemical staining: F=30.750, P＜0.05; Western blot: F=18.283, P＜0.05) protein relative expression was significantly higher than that of RIRI group, and the differences were statistically significant. The results of linear regression analysis showed that the difference in the number of TNF-α+ cells in the RIRI group and the NAS group was negatively correlated with the difference in the number of Nrf2+ and HO-1+ cells (r2=0.923, 0.936; P＜0.01).ConclusionsNAS can inhibit the expression of TNF-α protein in the retina of RIRI rats and reduce RIRI. The mechanism may be related to the Nrf2/HO-1 pathway.
Objective To investigate the expression of nuclear factor (NF)-κB and intercellular adhesion molecule (ICAM)-1 in rat′s retina injured by ischemia-reperfusion, and the effect of pyrrolidine dithiocarbamate (PDTC) on the expression of NF-κB and ICAM-1. Method The model of retinal ischemia-reperfusion was set up in 60 SD rats, which were divided into two groups with 30 rats in each: ischemia-reperfusion group and ischemia-reperfussion with injection of PDTC group. The left cephalic artery of each rat was ligated, and the right side was the control. Every group was subdivided into group 1 hour, 6, 12, 24, 48, and 72 hours after ischemia-reperfusion injury, and with 5 rats in each group. mRNA of NF-κB and ICAM-1 mRNA was measured by in situ hybridization (ISH) method in rat′s retina. Every rat underwent electroretinography (ERG) at the corresponding time before executed by neck breaking. Results In ischemia-reperfusion group, expression of NF-κB and ICAM-1 was detected at the 6th hour after ischemia-reperfusion, reached the highest level at the 24th hour, and weakened gradually later. In ischemia-reperfusion with injection of PDTC group, expression of NF-κB and ICAM-1 was detected at the 12th hour after ischemia-reperfusion, and reached the highest level at the 24th hour but lower than that in ischemia-reperfusion group. No expression of NF-κB and ICAM-1 was found in the control group. The relative recovery rate of ERG a and b wave amplitude in ischemia-reperfusion groups was lower than that in ischemia-reperfusion with injection of PDTC group at every stage(P＜0.01 ). The lowest relative recovery rate of ERG a and b wave amplitude in different stages in both of the 2 groups was at the 24th hour(P＜0.01). Conclusions NF-κB and ICAM-1 may play an important role in retinal ischemia-reperfusion injury, as the inhibitor of NF-κB, PDTC may relieve the retinal ischemia-reperfusion injury. (Chin J Ocul Fundus Dis，2004，20：175-178)
Objective To explore the effect of ischemia-reperfusion injury on the retinal functions of rats. Methods Seventy Wistar rats were selected, 20 of which were selected randomly and divided into two groups (control group and single-irrigated group). The rats were anesthetized and their anterior chambers of the right eyes were cannulated with a 7-gauge needle connected to a reservoir containing ringers balanced salt solution, which was maintained at the same level o f the eye for 1 hour. After that, ERG was recorded in both eyes of all rats. All the left rats were divided randomly into 10 groups and they were treated as the single-irrigated group. Retinal ischemia was induced by raising the reservoir to a height of 150 mm Hg. One hour later except the single ischemia group, all o f t he groups resumed perfusion after 3,6,12,and 24 hours and 3,5,7,14,and 21 days s eparately. ERG was recorded in both eyes of all rats.Results There was no difference in the results of ERG between left and right eyes in either the control group or the single-irrigated group. All the waves of ERG vanished in the single-ischemia group after 1 hour. In the ischemia-reperfusion groups, the waves of ERG partly recovered and the amplitude reduced persistently and progressively.Conclusion Ischemia-reperfusion injury may affect the function of the retina persistently and progressively. (Chin J Ocul Fundus Dis，2003，19：201-268)
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)
Exosomes are nanovesicles actively secreted by cells, which selectively encapsulate biologically active molecules such as proteins, RNA, and cytokines. They play an important role in intercellular communication, immune regulation, and maintenance of homeostasis, which can also be used as carriers for targeted drug delivery. Retinal ischemia-reperfusion injury (RIRI) is a retinopathy that seriously threatens human vision. At present, the clinical treatment of these diseases are symptomatic treatments, and some patients have poor efficacy or even blindness. As extracellular vesicles rich in functional proteins and RNAs, exosomes can not only be used as drugs for the treatment of RIRI, but also be used as carriers for drug delivery to play synergistic therapeutic effects. In the future, with the deepening of the research on the molecular structure, contents and biological functions of exosomes, as well as the continuous development of ophthalmic biology and genetic engineering technology, exosomes are expected to exert their great potential as therapeutic drugs and carriers, and become an important means of treating RIRI.
Objective To investigate the damage to the retinal cells and apoptosis of retinal cells of rats after ischemia-reperfusion insult. Methods The retinal ischemia-reperfusion model was developed by increasing intraocular pressure to 109725 mm Hg in rat eyes. Morphological changes of the rat eyes were observed by means of routine histopathology with HE staining. Apoptosis of the retina was assayed by both DNA fragmentation gel-electrophoresis and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL). Results Compared with the normal control, no histopathological changes were revealed in the rat retinas 30 min after the ischemia and then reperfued for 24 h or 48 h. Retinal ganglion cell layer (RGL) and inner plaxiform layer (IPL) of the retina were observed, however, to become significantly thinner 60 min after the ischemia and then reperfued for 24 h or 48 h. Together with the pathological changes DNA ladder pattern was detected in the same group of the rats. Further, immunochemical stain of the eye demonstrated that TUNEL positive cells were localized in RGL and IPL of the retina. Conclusion Ischemia-reperfusion insult of the eye may remarkably damage the retina of the rat eye. The damage to the retinal cells is mainly localized within RGL and IPL and apoptosis is the important mechanism of the retinal disorder. (Chin J Ocul Fundus Dis, 2002, 18: 296-298)