首頁 > 期刊首頁 > 生理學報 > 2006年6期 > 葛根素減輕部分由過氧亞硝基陰離子導致的糖尿病大鼠晶狀體上皮細胞凋亡
葛根素減輕部分由過氧亞硝基陰離子導致的糖尿病大鼠晶狀體上皮細胞凋亡
Puerarin decreases lens epithelium cell apoptosis induced partly by peroxynitrite in diabetic rats
- doi：
- 摘要：
- 本研究觀察葛根素是否減輕部分由過氧亞硝基陰離子(peroxynitrite,ONOO-)導致的糖尿病大鼠晶狀體上皮細胞(lens epithelium cell,LEC)凋亡.采用大鼠腹腔注射鏈脲佐菌素(streptozotocin,STZ)的方法建立糖尿病動物模型.36只大鼠作為對照組,腹腔注射生理鹽水;其他72只大鼠腹腔注射STZ(45 mg/kg)后分為STZ組和STZ+葛根素組,每組36只.STZ注射3 d后,STZ+葛根素組大鼠每天腹腔注射葛根素(140 mg/kg).于實驗開始后第20、40和60天用裂隙燈檢查晶狀體的形態學變化后處死動物.用流式細胞儀檢測LEC凋亡,用免疫組化方法檢測晶狀體中ONOO的標志物--硝基酪氨酸(nitrotyrosine,NT)的表達,用基因芯片分析技術檢測LEC凋亡相關基因iNOS等的表達.結果發現,對照組大鼠晶狀體均透明,各項指標基本正常;STZ組大鼠第20天時即出現晶狀體混濁,40～60 d期間混濁不斷加重;STZ+葛根素組大鼠20～40 d時晶狀體混濁呈加重趨勢,但40～60 d以后明顯減輕.對照組LEC輕度凋亡,而STZ組凋亡細胞呈持續性增長,STZ+葛根素組大鼠20～40 d時細胞凋亡呈增長趨勢,但40～60 d以后明顯下降.對照組大鼠晶狀體NT未見明顯表達;STZ組大鼠NT表達明顯加強;STZ+葛根素組大鼠20～40 d時NT表達呈增長趨勢,但40～60 d以后明顯下降.對照組凋亡相關基因未見明顯變化,STZ組凋亡相關基因iNOS表達明顯上調.其他凋亡相關基因如BCL-2、SOD表達明顯下調,但NF-кB和TNFR1-FADD-caspase信號轉導途徑明顯上調;STZ+葛根素組凋亡相關基因表達則呈相反改變.上述結果表明,在糖尿病大鼠晶狀體中有ONOO- 的標志物NT表達,證明糖尿病大鼠LEC凋亡部分由ONOO誘導,這可能是氧化損傷導致白內障形成的新途徑.葛根素能夠部分逆轉ONOO- 對LEC的致凋亡作用,提示葛根素可能是治療糖尿病性白內障的有效藥物,其治療機制可能與葛根素直接抑制凋亡和對抗ONOO-對糖尿病大鼠LEC的損傷有關.
- Abstract：
- The present study was designed to observe if puerann decreases lens epithelium cell(LEC)apoptosis induced partly by peroxynitrite(ONOO-).One hundred and eight rats were randomly divided into control group(n=36),streptozotocin(STZ)group (n=36)and STZ+puerarin group(n=36).The rats in the control group intraperitoneally(i.p.)received 0.5 ml of saline.The rats in STZ group and STZ+puerarin group received intraperitoneal injection of STZ(45 mg/kg).Three days later,the rats in STZ+puerarin group were given puerarin(140 mg/kg per day,i.p.).On days 20,40 and 60 of the experiment,morphologic changes of lenses were observed with slit lamp.Then the animals were sacrificed for further analysis.The amount and percentage of apoptotic LECs were determined by flow cytometry.Nitrotyrosine(NT, the foot print of ONOO-)was examined by immunohistochemistry.Apoptosis-related genes (iNOS,etc.)were analyzed by gene array.The results showed that in the control group,all the lenses were clear.In STZ group,gradually severe opacity of the lens was observed on days 20,40 and 60.But in STZ+puerarin group,mild opacity of the lens was observed on day 20 and more severe on day 40,but markedly decreased on day 60.In the control group,mild apoptosis of LECs was observed.In STZ group,time-dependent increase in apoptosis of LECs was observed.In STZ+puerarin group,mild apoptosis of LECs was observed on day 20,significantly increased on day 40,but markedly decreased on day 60.There was no expression of NT in the lens in the control group,but an increased expression of NT in STZ group.In STZ+puerarin group,mild expression of NT was observed on day 20,significantly increased on day 40,but markedly decreased on day 60.There was no expression of iNOS in the lens in the control group,but continuous up-regulation of iNOS expression in STZ group.In STZ+ puerarin group,mild expression of iNOS was observed on day 20,significantly increased on day 40,but markedly decreased on day 60.Except the changes of iNOS related to caspase signal transduction way were up-regulated in STZ group.The results were opposite in STZ+puerarin group and the control group.These findings show that NT is expressed in diabetic rat lens,which proves that LEC apoptosis in diabetic lens is partly induced by ONOO- which may be a new oxidative damage way to form cataract.Puerarin partly decreases LEC apoptosis induced by ONOO- and is a potential medicine for therapy of diabetic cataract.The mechanism of puerarin dealing with diabetic cataract may be related to its direct inhibition of LEC apoptosis and antagonism of ONOO- in diabetic rats.
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