Objctive To explore the relationship between the expression of Fas/FasL and the apoptosis occurs in retinal ischemia/reperfusion injury of rats , as well as the therapeutic effects of bFGF on the ischemic retina.Methods Th emodels of retinal ischemia/reperfusion injury was made by transient elevating introcular pressure. A total of 28 rats were divided into normal and operation group.The latter were subdivided into 1 hour, 6, 12, 24, 48 and 72 hours after reperfusion group, in which the left eyes of the rats were in the ischemia/reper fusion groups and the right ones were in the treatment groups (bFGF intracameral injection). Apoptosis was assessed by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labelling (TUNEL) method, and the expression of Fas and Fas ligand was studied by strept avidin-biotin complex （SABC）immunohistochemistry. Results No positive cells were observed in the normal rats′retinae, but there was a significant number of TUNEL positive cells in 6-24 hours after transient ischemia followed by a decrease at the 48th hour. The number of TUNEL positive cells reached a maximum at the 24th hour after ischemia. The expression of Fas gradually increased as early as when it was at the 6th hour, reached a peak at the 24th hour, and then decreased at the 48th hour. Similarly, the expression of Fas ligand was at peak in 24-48 hours in GCL and INL of retina. Conclusions Retinal ischemia-reperfusion after transient elevated IOP induced apoptosis of cells in the retina. Fas/FasL may play an important role in the early events of the apoptotic pathways. bFGF can rescue RGCs from retinal ischemia/reperfusion injury through downregulation of the expression of Fas/FasL and may represent an important mechanism for therapeutic neuroprotection. (Chin J Ocul Fundus Dis，2003，19：160-163)
【Abstract】ObjectiveTo explore the protective effect of ligustrazine on the ischemia-reperfusion injury of rat liver. MethodsNinety-six healthy SD rats were divided randomly into three groups: sham operation group, ischemiareperfusion group（I/R group) and ischemia plus ligustrazine reperfusion group(therapy group).The plasm ALT,AST and LDH were measured before operation,at thirty minutes,six hours and twentyfour hours after operation. One week survival and liver pathological change of every group were observed, and the hepatocyte apoptosis index was measured simultaneously.ResultsOne week survival of therapy group was higher than that of I/R group (P＜0.05). The plasm ALT,AST and LDH of therapy group and I/R group were higher than those of the sham operation group significantly (P＜0.05), and those of therapy group were lower than those of the I/R group (P＜0.05). Light microscopy indicated that the liver sinusoid and central veins were congested remarkably after operation, the hepatocyte necrosis in I/R group was more severe than that in therapy group, and the hepatocyte apoptosis index of I/R group was higher than that of therapy group (P＜0.05). ConclusionThe protective effect of ligustrazine on ischemia-reperfusion injury of rat liver is obvious.
Objective:To observe the effect of beta;estradiol on gluta mate concentration in rabbitsprime; retinae injured by ischemic reperfusion. Methods:Twenty r abbits ware randomly divided into two groups, the control group and the treatmen t group, with 10 rabbits in each group. Before examined by binocular flash elect roretinography (FERG), retinal ischemic reperfusion (RIR) model was induced in t h e right eyes of all the rabbits by increasing intraocular pressure to 120 mm Hg for 60 minutes; the left eyes were as the control eyes. The rabbits were hypoder mically injected with beta;estradiol (0.1 mg/kg) in treatment group and with phys i ological saline in the control group 2 hours before ischemia. The results of FER G of the right eyes in both of the 2 groups 0, 4, 8, and 24 hours after reperfus ion were record respectively and were compared with the results of FERG before r eperfusion. The retina tissue was collected after the last time of FERG. The con c entration of glutamate was detected by Hitachi L8800 amino acid analyzer. Results:In the right eyes in both of the 2 groups, the result of F ERG showed a beeli ne just after reperfusion. There was no significant difference of awave amplit u de between the 2 groups (t=1.357, 0.798, 0.835; Pgt;0.05); the b wave amplitudes i n experimental group were much higher than those in the control group (t=4.447, 2.188, 3.106; Plt;0.01). The concentration of glutamate in retina was (0.265plusmn;0.014) g/L in the right eyes and (0.207plusmn;0.013) g/L in the left eyes in the control group, and (0.231plusmn;0.007) g/L in the right eyes and (0.203plusmn;0 .014) g/L in the le ft eyes in the treatment group; the difference between the 2 groups was signific ant (F=50.807, P=0.000). There was statistical difference between righ t and left eyes both in the 2 groups and the significant difference of the right eyes betw een the two groups was also found (P=0.000); there was no statistical diffe rence of the left eyes between the 2 groups (P＝0.505). Conclusion:beta;-estradiol may prevent the increase of the concentration of glutamate in retina induced by RIR to protect retinal tissue.
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.
【Abstract】Objective To study the mechanisms of enhancing effect of mild hypothermia (MH) to ischemic preconditioning (IP) on hepatic ischemiareperfusion (I-R) injury. Methods To observe the content of the marker enzymes of liver damage (ALT,AST,LDH) and malondialdehyde (MDA), and activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPX), total antioxidase (TAX) in inferior vena cava blood above liver in nonischemic control group (n=6), I-R group (n=6), IP group (n=6) and mild hypothermic ischemic preconditioning (MHIP) group (n=6). Results After I-R the content of ALT,AST, LDH and MDA were significantly elevated (P＜0.01), SOD,CAT,GSH-PX,ACT activities were declined obviously (P＜0.01). The content of ALT,AST,LDH and MDA were significantly lower in IP group than those in I-R group, and in MHIP group than those in IP group (P＜0.01,P＜0.05), and the content of SOD, CAT,GSH-PX, ACT activities were significantly higher in IP group than those in I-R group, and in MHIP group than those in IP group (P＜0.01,P＜0.05). Conclusion Ischemic preconditioning may enhance the oxidation-resistance of liver, and reduce the oxygen free radical injury to liver after ischemia-reperfusion. Mild hypothermia may enhance the protective effect of IP on hepatic ischemiareperfusion injury.
The classical Hippo pathway leads to the phosphorylation of downstream effector molecules Hippo-Yes-associated protein (Yap) and transcriptional coactivator PDZ-binding motif (Taz) serine sites through a kinase response, thereby promoting cell proliferation, controlling cell polarity, changing cytoskeleton, it plays an important regulatory role in various pathophysiological processes such as epithelial-mesenchymal transition and inhibition of cell contact. Studies have shown that Yap/Taz can affect the progression of vitreoretinal diseases, opening up new prospects for the pathogenesis and clinical treatment of diabetic retinopathy, proliferative vitreoretinopathy, and retinal ischemia-reperfusion injury. Exploring the molecular mechanism of Yap/Taz provides a possible therapeutic target for future research in the treatment of retinal fibrosis diseases such as diabetic retinopathy and proliferative vitreoretinopathy. At the same time, regulating the activity of local Yap/Taz in the retina will also become an effective therapeutic target for damage-repair in retinal ischemia-reperfusion injury. However, Yap inhibitors have potential retinal toxicity and are still in the preclinical development stage. Further research on the mechanism of action and clinical safety of Yap inhibitors will provide new methods for the treatment of retinal diseases.
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)
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)
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.
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)