CAJ | 학술논문

背景先前的研究已证实,绿茶提取物表没食子儿茶素没食子酸酯(EGCG)能提高大鼠视神经钳夹伤后视网膜神经节细胞(RGCs)的生存率.星形胶质细胞(AS)在神经系统损伤中对神经元的修复起重要作用,而EGCG对视神经钳夹伤后AS反应活性的影响尚有待证实.胶质纤维酸性蛋白(GFAP)是AS的特异性标记物.目的观察EGCG对大鼠视神经钳夹伤后视神经GFAP表达的影响.方法将72只Wistar大鼠随机分为正常对照组、假手术+EGCG组、视神经钳夹伤+生理盐水组、视神经钳夹伤+EGCG组,每组18只.于大鼠球后2 mm处用夹持力40 g的微型视神经夹垂直视神经钳央60 s建立视神经钳夹伤模型,假手术大鼠仅切开眼外软组织,不损伤视神经.假手术+EGCG组和视神经钳夹伤+EGCG组大鼠术前2 d起每日给予25 mg/kg EGCG腹腔注射至术后2 d,随后改为每日2 mg/kg口服.采用免疫组织化学染色及Western blot法检测并比较各组大鼠造模后7、14、28 d视神经组织中GFAP的表达.结果免疫组织化学染色显示,正常对照组和假手术+EGCG组视神经组织中GFAP呈弱表达;造模后7、14、28 d,视神经钳夹伤+生理盐水组GFAP表达明显增强.视神经钳夹伤+EGCG组GFAP的表达强于正常对照组,弱于视神经钳夹伤+生理盐水组.Western blot检测表明,造模后视神经组织GFAP的表达量较正常对照组明显增高,差异有统计学意义(P＜0.01);造模后7 d、14 d,视神经钳夹伤+EGCG组GFAP的表达量明显低于视神经钳夹伤+生理盐水组,差异均有统计学意义(P＜0.05).结论全身应用EGCG可以下调大鼠视神经钳夹伤后视神经组织中GFAP的表达,降低AS的增生活性,提示EGCG可以抑制视神经创伤修复过程中的瘢痕形成.
배경 선전적연구이증실,록다제취물표몰식자인다소몰식자산지(EGCG)능제고대서시신경겸협상후시망막신경절세포(RGCs)적생존솔.성형효질세포(AS)재신경계통손상중대신경원적수복기중요작용,이EGCG대시신경겸협상후AS반응활성적영향상유대증실.효질섬유산성단백(GFAP)시AS적특이성표기물.목적 관찰EGCG대대서시신경겸협상후시신경GFAP표체적영향.방법 장72지Wistar대서수궤분위정상대조조、가수술+EGCG조、시신경겸협상+생리염수조、시신경겸협상+EGCG조,매조18지.우대서구후2 mm처용협지력40 g적미형시신경협수직시신경겸앙60 s건립시신경겸협상모형,가수술대서부절개안외연조직,불손상시신경.가수술+EGCG조화시신경겸협상+EGCG조대서술전2 d기매일급여25 mg/kg EGCG복강주사지술후2 d,수후개위매일2 mg/kg구복.채용면역조직화학염색급Western blot법검측병비교각조대서조모후7、14、28 d시신경조직중GFAP적표체.결과 면역조직화학염색현시,정상대조조화가수술+EGCG조시신경조직중GFAP정약표체;조모후7、14、28 d,시신경겸협상+생리염수조GFAP표체명현증강.시신경겸협상+EGCG조GFAP적표체강우정상대조조,약우시신경겸협상+생리염수조.Western blot검측표명,조모후시신경조직GFAP적표체량교정상대조조명현증고,차이유통계학의의(P＜0.01);조모후7 d、14 d,시신경겸협상+EGCG조GFAP적표체량명현저우시신경겸협상+생리염수조,차이균유통계학의의(P＜0.05).결론 전신응용EGCG가이하조대서시신경겸협상후시신경조직중GFAP적표체,강저AS적증생활성,제시EGCG가이억제시신경창상수복과정중적반흔형성.
Background Our previous study demonstrated that epigallocateehin-gallate(EGCG),an active ingredient of green tea,has protective effect on optical nerve after optic nerve crush.Astrocyte was proved to play key role in the repair of nerve tissue,but the influence of EGCG on astrocyte is unclear.Glial flbrillary acidic protein (GFAP) is a special marker for astrocyte. Objective The aim of this study was to investigate the effect of EGCG on the expression of GFAP in optic nerve tissue after optic nerve crush. Methods Seventy-two clean Wistar rats were randomly divided into normal control group,sham+EGCG group,optic nerve crush+normal saline group(vehicle group),optic nerve crush+EGCG group.Optic nerve crush models were established by clamping optical nerve for 60 seconds by minitype optic nerve clipper with the force of 40 gram.Only ocular tissue was cut in the rats in sham group.Normal saline solution or EGCG(25 mg/kg)was intraperitoneally injected daily for 5 days consecutively and orally administered(2 mg/kg)daily afterwards.The expression of GFAP in optic nerve was detected by immunohistochemistry and quantified by Western blotting analysis on day 7,14 and 28 after modeling. Results lmmunochemistry showed that GFAP were weakly expressed in the rats of both normal group and sham+EGCG group with the sliSht brown staining in optic nerve tissue.The deeply brown staining for GFAP was seen in vehicle group,and the staining intensity weakened in optic nerve crush+EGCG group compared to vehicle group on days 7,14 and 28 after modeling.Western blotting analysis revealed that the expression level of GFAP in rat optic nerve tissue of vehicle group was significantly enhanced in comparison with normal control group(P＜0.01).On day 7 and 14 after optic nerve modeling,the expression levels of GFAP were evidently decreased in optic nerve crush+EGCG group in comparison with vehicle group(P＜0.05).However,on day 28 after modeling,no significant difference wag found in the expression levels of GFAP between vehicle group and optic nerve erush+EGCG group(P＞0.05). Conclusion EGCG down-regulates optic nerve crush-induced of GFAP in the optic nerve and therefore attenuates the activity of astrocytes,suggesting that EGCG might reduce the formation of glial scar.