Puerarin decreases apoptosis of retinal pigment epithelial cells in diabetic rats by reducing peroxynitrite level and iNOS expression / 生理学报

The purpose of this study was to investigate the protective effect of puerarin on retina pigment epithelial (RPE) cells of diabetic rats against apoptosis. One hundred and eight Sprague-Dawley (SD) rats were randomly divided into 3 groups: control group, streptozotocin (STZ) group and puerarin group. STZ and puerarin groups received 3 d of STZ injection (45 mg/kg per day, i.p.). Additionally, puerarin groups were treated with puerarin (140 mg/kg, i.p.) from the 4th day to the end of experiment. The rats from different groups were sacrificed on 20, 40 and 60 d after STZ injection for harvesting RPE cells. Western blot analysis, DNA laddering, RT-PCR and immunohistochemistry were used for determining the expression of nitrotyrosine (NT, the foot print of peroxynitrite), cell apoptosis, iNOS mRNA and Fas/Fas ligand (FasL) signal transduction in RPE cells, respectively. The results showed that control group maintained low apoptosis level and little NT, iNOS mRNA, Fas/FasL protein expressions, as well as normal blood glucose and body weight during 60 d of the experiment. Compared with control group, STZ group showed obvious apoptosis and higher NT, iNOS mRNA, Fas/FasL protein expressions from 20 d after STZ injection. Puerarin relieved apoptosis of RPE cells and decreased NT, iNOS mRNA, Fas/FasL protein expressions in puerarin group 20 or 40 d after STZ injection, compared with STZ group. These results suggest puerarin can decrease RPE cells apoptosis in diabetic rats by reducing peroxynitrite level and iNOS expression, thus being a potential therapeutic agent in controlling of diabetic retinopathy.

Inducible nitric oxide synthase and Fas/FasL with C3 expression of mouse retinal pigment epithelial cells in response to stimulation by peroxynitrite and antagonism of puerarin / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Retinal pigment epithelial (RPE) cell is a monolayer of multifunctional cells between the retina and the choroid. Peroxynitrite (ONOO(-)) is known to induce toxicity on RPE cells. This study aimed to evaluate ONOO(-) induced expression of inducible nitric oxide synthase (iNOS) and complement 3 (C3) via Fas/FasL pathway in RPE cells and the values of puerarin as a therapeutic target for inhibiting the apoptosis of RPE cells.</p><p><b>METHODS</b>RPE cells were obtained from eyes of C57BL/6 mice. RPE cells were divided into control, ONOO(-) and puerarin groups. Control group was treated with saline, ONOO(-) group was treated with ONOO(-), and puerarin group was treated with puerarin after added with ONOO(-). All changes were observered at 6, 12 and 24 hours after treatment. Western blotting analysis was used to determine the expression of nitrotyrosine (NT, the foot print of ONOO(-)) and C3; flow cytometry was used to determine the apoptosis of RPE cells. Immunohistochemistry and Western blotting were used to determine Fas/FasL signal transduction. Gene array analysis, reverse transcription polymerase chain reaction (RT-PCR) and Western blotting were used to determine the expression of iNOS mRNA and iNOS protein in RPE cells.</p><p><b>RESULTS</b>There were minor expression of NT, C3, Fas/FasL and iNOS mRNA in control group, and strong expression of NT and C3 in ONOO(-) group, while in puerarin group weak expressions of NT and C3 were detected as time passed by (P < 0.001). Apoptosis of RPE cells occured and reached a higher level at 6 and 24 hours after addition of ONOO(-) respectively in ONOO(-) group, but delayed apoptosis in puerarin group (P < 0.05). Compared to control group, the expression of Fas/FasL was up-regulated in ONOO(-) group, but was down-regulated in puerarin group (P < 0.001). Similarly, the expressions of iNOS mRNA and iNOS protein in ONOO(-)group were up-regulated in ONOO(-) group, but down-regulated in puerarin group (P < 0.001).</p><p><b>CONCLUSIONS</b>ONOO(-) expresseion in RPE cells may constitute the new way of oxidant stress. Fas/FasL signal transduction pathway and C3 may affect and reinforce apoptosis mediated by ONOO(-). Puerarin could reverse ONOO(-) damage on RPE cells. The antagonizing mechanism of puerarin may be related to its inhibitory to the expression of iNOS mRNA, and therefore decrease ONOO(-) formation as well as directly antagonize the effect of ONOO(-). Furthermore, puerarin may be an useful therapeutic agent against apoptosis of RPE cells.</p>

Semenogelin and sperm motility inhibition: an update / 中华男科学杂志

Semen liquefaction and sperm capacitation are the key processes for sperm to acquire forward movement ability. In these processes, semenogelin plays a vital role by directly participating in the formation of semen coagulation, collaborating with other protease and metal ions from the male reproductive tract, and then reacting with the surface of sperm cells, finally involved in the regulation of these processes and ensuring sperm's acquisition of forward movement ability.

Optimization of culture medium for primary retinal pigment epithelium cells and investigation of medium effcts on growth factor expression / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To optimize the conditions for in vitro culture of retinal pigment epithelium (RPE) cells, we characterized expressions of various growth factors in RPE cells, including tumor necrosis factor (TNF-α), vascular endothelial growth factor (VEGF), β fibroblast growth factor (βFGF), transforming growth factor β2 (TGFβ2), and interferon-γ (IFN-γ). We also studied expressions of caspase-3 under different concentrations of fetal bovine serum (FBS) with insulin-transferrin-sodium selenite (ITS) supplement. METHODS: First, we investigated if expressions of TNF-α, VEGF, βFGF, TGFβ2, IFN-γ, and caspase-3 in FBS and ITS with of concentration. Second, we cultured primary RPE cells from eyes of forty C57 BL/6 mice in standard dulbecco's modified eagle's medium (DMEM) containing 20,40,100mL/L FBS and 20,40,100mL/L FBS together with 10g/L ITS. Immunohisto-chemical staining and cell counting were performed to verify the existence and growth condition of RPE cells. Expressions of TNF-α, VEGF, βFGF, TGFβ2 and IFN-γ were determined using cells and supernatant from passage-3 to -4 primary RPE cell after 48 hours of culture with RT-PCR and enzyme-linked immunosorbent assays (ELISA). The expression of casepase-3 was determined via Western blotting. The major outcome measurement is the expression level of growth factors in cultured RPE cells and the experiment design is to expose the RPE cells to different culture medium. RESULTS: TNF-α, VEGF, βFGF, TGFβ2, but not IFN-γ, were expressed and the expressions increased with concentration. No expression of the aforementioned genes was detected in presence of ITS. The primary cultures of RPE cells were successfully established. TNF-α, VEGF, βFGF, TGFβ2 (but no IFN-γ) and the active caspase-3 were detected in 20,40,100mL/L FBS or 20,40,100mL/L FBS combined with 10g/L ITS; the expressions were upregulated with increasing concentration of FBS. There is no significant difference in the expression of growth factors between these groups. However, significant differences were shown among different concentration of FBS (P＜0.01）. The lowest expression was observed in 20mL/L FBS or 20mL/L FBS combined with 10g/L ITS medium with RPE cells. But RPE cells were shown in better growth condition in 20mL/L FBS combined with 10g/L ITS.CONCLUSION: TNF-α, VEGF, βFGF, TGFβ2 and caspase-3 were expressed in RPE cells and supernatants. The production of above 20mL/L FBS combined with 10g/L ITS in DMEM may be the ideal cell culture medium that supports the normal growth of RPE cells.

The antagonism of cholecystokinin octapeptide-8 to the peroxynitrite oxidation on a diabetic cataractal rat model / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cataracts is considered be formed because of an abnormal glucose metabolic pathway or oxidative stress. We explored the damaging role of ONOO- and antagonism of cholecystokinin octapeptide-8 (CCK-8) in diabetic cataractal rat lenses.</p><p><b>METHODS</b>A diabetic cataractal animal model was established by peritoneal injection of streptozotocine (STZ). Thirty-six normal SD rats were taken as control group; seventy-two were given STZ (45 mg/kg) and then divided into STZ group and CCK-8 group (peritoneal injection CCK-8). STZ induced diabetic rats were treated with CCK-8 for 60 days. Lenses were examined with slit lamp at 20, 40 and 60 days. Immunofluorescent staining and Western blot analysis were used for determining nitrotyrosine (NT, a marker for ONOO-). PT-PCR and gene array analysis were used for determining the expression of inducible nitric oxide synthetase mRNA (iNOS mRNA) in lens epithelium (LEC).</p><p><b>RESULTS</b>STZ group rats developed lens opacity by 20 days that reached a high level by 60 days after STZ injection. CCK-8 group rats delayed the cataract formation. CCK-8 group rats delayed the cataract formation. There was no distinct expression of NT and iNOS mRNA in control group. In STZ group, there were distinct expression of NT and upregulation of iNOS mRNA; however, CCK-8 group showed weak expression of NT and downregulation of iNOS mRNA.</p><p><b>CONCLUSIONS</b>NT, which may be a new form of oxidative stress, was expressed in diabetic rat LEC although CCK-8 could reverse NT damage in LEC. The results suggested that CCK-8 might be a useful therapeutic agent against diabetic cataract. The antagonizing mechanism of CCK-8 may be related to direct antagonism of ONOO- as well as its inhibition of the expression of iNOS mRNA for production of NO and therefore decrease in the formation of ONOO-.</p>

Puerarin decreases lens epithelium cell apoptosis induced partly by peroxynitrite in diabetic rats / 生理学报

The present study was designed to observe if puerarin 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 NO production, the other apoptosis-related genes, including BCL-2 and SOD were down-regulated, while NF-kappaB and TNFR1-FADD-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.