Effect of kistrin on expression of collagen type IV in lens posterior capsule / 中华实验眼科杂志

BackgroundThe proliferation of lens epithelial cellsLECs) following extracapsular cataract extraction is the biological basis of posterior capsular collagen and cataract formation.Disintegrin is certified to competitively bind the integrin with extracellular matrix and therefore prevent the posterior capsular opacification (PCO).But,its molecular mechanism is below understand.ObjectiveThe present study was to investigative the effects of disintegrin (kistrin) on the expression of collagen in lens posterior capsular.MethodsThe right eyes of 24 New Zealand white rabbits received transparent lens extracapsular enudeation and were randomly divided into two groups using random number table,0.2 ml of kistrin ( 80 mg/L) was intracapsularly injected at end of the operation in 12 eyes ( kistrin group) and the same volume of normal saline solution was used at the same way in other 12 operative eyes ( normal saline group).The PCO was graded in postoperative 1,3,5,7,14 days on Odrich' s criteria under the slit lamp.The lens section was prepared at 14 days and 3 months after operation.Haematoxylin and eosin stain was used to examine the proliferation of LECs in posterior capsule; Masson stain was used to observe the collagenous fiber formation in capsule bag,and the expression of collagen type Ⅳ was detected by immunochemistry.Results No significant difference in the number PCO eye was found in postoperative 14 days between normal saline group and kistrin group ( P =0.093 ).However,the eye numbers of 2-3 grades of PCO were significant increased in normal saline group compared with kistrin group in 1,2,3 months after operation( P=0.041,0.014,0.022).In the operative 14 days,staining and adhesion of LECs in posterior capsule were more in normal saline group than kistrin group,and the fibrocytes in capsule were evidently increased in normal saline group in 3 months.Masson stain certified that the blue stain was seen to be stronger and more in posterior capsule in normal saline group in comparison with kistrin group in 3 months after operation,and the immunochemistry showed that the gray values of collagen type Ⅳ in posterior capsule were significant lower in normal saline group compared with kistrin group in both 14 days and 3 months after operation (P=0.000,0.001 ).ConclusionsKistrin can suppresses the proliferation of LECs and collagen type Ⅳ on rabbit lens posterior capsular after transparent lens extracapsular enudeation.

Establishment of model of diabetes and lens posterior capsule opacification induced by alloxan in rabbit / 中华实验眼科杂志

Background The establishment of diabetic animal model is a crucial step for the study about diabetic eye diseases. At present,the main modeling method include the injection of streptozotocin and alloxan. But the shortcoming of the former is an expensive price, and that of the later is high death rate of animals. Objective This experiment was to discuss the way which decrease the death of alloxan-injected animal and explore the effects of high blood glucose on the posterior capsular opacification (PCO). Methods Forty clean healthy male New Zealand white rabbits were randomly divided into 2 groups. 90mg/kg of alloxan were injected via ear vein once in 20 rabbits to create the diabetic animal models,and the equivalent amount of normal saline solution was injected at the same way as normal blood glucose group. The successful models were selected in the animals with the blood glucose level over 12. 0 mmol/L two weeks later, and PCO of lens were graded based on the method of Odrieh under the slit lamp. Extracapsular lens extraction was then performed on the right eye of rabbits in both groups, and the posterior capsules were obtained from these eyes at the 6th, 10th and 14th days after operation. The expression of proliferating cell nuclear antigen ( PCNA ) in posterior capsular lens epithelial cell was detected by immunohistochemistry. Results The modeling successful rate was 70% after injection of alloxan. The body weight of rabbits in high blood glucose group was significantly lowed and the blood glucose was significantly elevated in comparison with normal blood glucose group ( all P<0. 05). Two weeks after surgery ,2 eyes occurred 2 grade of PCO and only one eye showed the 1 grade of PCO in the high blood glucose group. However, 1 grade of PCO was found in 3 eyes in the normal blood glucose group. Biopsy revealed that PCNA was positively expressed in the cell nuclei of LECs in high blood glucose group rather than the normal blood glucose group from the 10th day after surgery. The proliferation index of PCNA was 0. 86±0. 04 and 0. 25±0. 03 respectively in high blood glucose group and normal blood glucose group, showing a significant difference between them (t = -16. 171 ,P = 0. 000). Conclusion Stable diabetic models of rabbits can be created by intravenous injection of 90 mg/kg alloxan. High blood glucose level is one of the important factors for the development of PCO.

Changes of NF-kappaB/I kappa B alpha in N-methyl-N-nitrosourea-induced retinal damage in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the changes of nuclear factor-kappa B (NF-kappaB) in the course of N-methyl-N-nitrosourea (MNU)-induced apoptosis of rat retinal photoreceptor cells and investigate the mechanism of MNU-induced retinal damage.</p><p><b>METHODS</b>A single intraperitoneal injection of 60 mg/kg MNU was given to 50-day-old female rats, which were sacrificed at different intervals after MNU treatment. The retinal damage was examined with optical microscopy and photoreceptor cell apoptosis detected by TUNEL assay. Western blotting was performed to analyze the changes in NF-kappaB.</p><p><b>RESULTS</b>Pyknosis of the photoreceptor cell nuclei and disorientation of the outer segment of the photoreceptor layer was observed 24 h after MNU treatment, and the outer nuclear layer and photoreceptor layer were almost completely lost on day 7. Photoreceptor cell apoptosis peaked at 24 h, and in the apoptotic cascade, NF-kappaB p65 protein was only detected 12 and 24 h after MNU treatment, whereas the amount of I kappa B alpha, in contrast, markedly increased in the cytoplasm as well as in the nuclei.</p><p><b>CONCLUSION</b>MNU-induced retinal damage might be mediated through the signaling pathway of NF-kappaB/I kappa B alpha.</p>

N-methyl-N-nitrosourea-induced apoptosis of photoreceptor cells in Sprague-Dawley rats via nuclear factor-kappaB / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Previous studies have showed that photooxidative stress can lead to down-modulation of nuclear factor-kappa B (NF-kappaB) activity causing apoptosis of cultured photoreceptor cells. This study aimed at investigating whether NF-kappaB was involved in photoreceptor cells apoptosis induced by N-methyl-N-nitrosourea (MNU) in rats.</p><p><b>METHODS</b>A single intraperitoneal injection of 60 mg/kg MNU was given to 50-day-old female rats. At different intervals after MNU treatment, the animals were sacrificed. Retinal damage was examined by a light microscope. The apoptotic index of the photoreceptor cells was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL). NF-kappaB was analysed by Western blot and Transcriptin Factor Assay Kits.</p><p><b>RESULTS</b>The pyknosis of the photoreceptor nuclei and the disorientation of the outer segment of the photoreceptor layer was seen after MNU treatment for 24 hours. The outer nuclear layer and photoreceptor layer were almost completely lost at 7 days. Photoreceptor cells apoptosis reached the peaked value at 24 hours. In apoptotic cascade, the protein levels of NF-kappaB p65 were only detected after MNU treatment for 12 and 24 hours in the nucleus. Conversely, the amounts of IkappaBalpha were markedly increased in the cytoplasm as well as in the nucleus. The activity of NF-kappaB p65 in the nucleus was down-modulated in the end.</p><p><b>CONCLUSIONS</b>MNU-induced photoreceptor cell destruction was attributed to the apoptotic process by down-regulating the activation of NF-kappaB p65.</p>

Protective effects of ligustrazine against photoreceptor cell injury induced by N-methyl-N-nitrosourea and its mechanism / 药学学报

<p><b>AIM</b>To study the protective effect of ligustrazine against photoreceptor cell injury induced by N-methyl-N-nitrosourea (MNU) in Sprague-Dawley (SD) rats.</p><p><b>METHODS</b>Ligustrazine injections of different doses were injected intraperitoneally into 47-day female SD rats once a day and a single intraperitoneal injection of MNU 60 mg x kg(-1) was given to 50-day rats. At different intervals after MNU treatment,the animals were sacrificed. The apoptotic index of photoreceptor cells was calculated by TUNEL labeling at 24 h following MNU treatment; peripheral retinal damage was evaluated based on retinal thickness at the d 7 after MNU treatment, and the expression of c-jun and c-fos genes was detected by RT-PCR technique.</p><p><b>RESULTS</b>Ligustrazine injection could remarkably increase total thickness of peripheral retina and decrease apoptotic index of photoreceptor cells induced by MNU in a dose-dependent manner. Compared with MNU-treated rats, the gene expression of c-jun and c-fos was time-dependently down-regulated in ligustrazine-treated group.</p><p><b>CONCLUSION</b>Ligustrazine injection partially protects against MNU-induced retinal damage by down-modulating the expression of c-jun and c-fos genes to inhibit apoptosis of photoreceptor cells.</p>