Caffeic acid phenethyl ester improves peritoneal dialysis-associated peritoneal fibrosis by alleviating oxidative stress injury through activating nuclear factor erythroid-2-related factor 2/heme oxygenase-1 pathway / 中华肾脏病杂志

Objective:To investigate whether caffeic acid phenethyl ester (CAPE) would improve peritoneal dialysis (PD)-associated peritoneal fibrosis by alleviating oxidative stress through activating nuclear factor erythroid-2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway.Methods:Thirty-two male Sprague-Dawley rats were randomly divided into four groups by the random number table: control (CON) group (0.9% normal saline 20 ml/d intraperitoneal injection), CAPE group (0.9% normal saline 20 ml/d+CAPE 10 mg·kg -1·d -1 intraperitoneal injection), PD group [4.25% glucose peritoneal dialysis fluid (PDF) 20 ml/d intraperitoneal injection with lipopolysaccharide 0.6 mg/kg intraperitoneal injection at day 1, 3, 5 and 7], and PD+CAPE group (CAPE 10 mg·kg -1·d -1 intraperitoneal injection in addition to PD group), with 8 rats per group. On day 28, rats were euthanized after peritoneal equilibration test, and then the parietal peritoneum and omentum were collected for follow-up tests. To further investigate the mechanism, primary peritoneal mesothelial cells (PMCs) of rats were isolated and cultured. The PMCs were stimulated with 2.5% glucose PDF and added with 5 μmol/L CAPE intervention. The Nrf2 inhibitor (ML385) was used to identify whether CAPE protected PMCs from PDF by activating the Nrf2/HO-1 pathway. Histopathological staining was used to detect structural changes of the peritoneum, and immunohistochemical analysis was performed on cleaved caspase-3, Bax, α-smooth muscle actin (α-SMA), fibronectin (FN), and typeⅠ collagen (Col-Ⅰ) protein. Western blotting was used to detect the protein expression of α-SMA, FN, transforming growth factor-β1 (TGF-β1), HO-1 and nuclear Nrf2 (N-Nrf2). The apoptosis detection kit was used to detect apoptosis and flow cytometry was used to detect reactive oxygen species (ROS) in PMCs. The malondialdehyde (MDA) and superoxide dismutase (SOD) activity detection kit were used to detect MDA content and SOD activity. Cell immunofluorescence was used to analyze the protein expression of Nrf2 in PMCs. Results:Compared with the CON group, the PD group had thicker peritoneum, and the expression levels of cleaved caspase-3, Bax, α-SMA, FN, Col-Ⅰand MDA in peritoneum were significantly higher, while HO-1, N-Nrf2 protein expression and SOD activity were lower (all P<0.05). Compared with the PD group, the parietal peritoneum morphology of CAPE+PD group was improved, accompanied by reduced cleaved caspase-3, Bax, α-SMA, FN, Col-Ⅰ protein expression, and MDA content, while N-Nrf2, HO-1 protein expression, and SOD activity were higher (all P<0.05). Compared with the CON group, the PD group had significantly lower ultrafiltration volume and higher peritoneal permeability (both P<0.05). After CAPE intervention, the peritoneal transport function of the rats was significantly improved ( P<0.05). In cultured PMCs, PDF inhibited nuclear translocation of Nrf2 and protein expression of HO-1, and upregulated intracellular ROS level. In addition, PDF increased cell apoptosis and the protein expression levels of α-SMA, TGF-β1 and FN (all P<0.05). CAPE activated nuclear translocation of Nrf2, increased HO-1 protein expression, downregulated intracellular ROS level, and partially reversed PDF-induced cell apoptosis and epithelial- mesenchymal transition (all P<0.05). The protective effects of CAPE on PMCs were partially abolished by ML385 (all P<0.05). Conclusions:CAPE can reduce PD-induced PMCs apoptosis and epithelial-mesenchymal transition by attenuating oxidative stress, and significantly improve peritoneal fibrosis and ultrafiltration function. The beneficial effects of CAPE on peritoneum are related to activation of Nrf2/HO-1 pathway.

Protective Effects of Anthocyanins Extracted from Vaccinium Uliginosum on 661W Cells Against Microwave-Induced Retinal Damage / 中国结合医学杂志

OBJECTIVE@#To study the protective effect of anthocyanins extracted from Vaccinium Uliginosum (VU) on retinal 661W cells against microwave radiation induced retinal injury.@*METHODS@#661W cells were divided into 6 groups, including control, model [661W cells radiated by microwave (30 mW/cm2, 1 h)] and VU groups [661W cells pretreated with anthocyanins extracted from VU (25, 50, 100 and 200 µg/mL, respectively) for 48 h, and radiated by microwave 30 mW/cm2, 1 h]. After treatment with different interventions, the cell apoptosis index (AI) was determined using Heochst staining; contents of malonaldehyde (MDA), glutataione (GSH), and activity of superoxide dismutase (SOD) were measured. mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1(HO-1) were detected by real time quantitative polymerase chain reaction, and the expression of HO-1 protein was examined by Western blot analysis. Nucleus and cytoplasm were separated and Nrf2 protein expression was further verified by Western blot analysis.@*RESULTS@#There was significant difference in AI among the groups (F=322.83, P<;0.05). Compared with the control group, AI was significantly higher in the model group and was lower in 4 VU-pretreated groups (P<;0.05). Linear regression analysis showed the decline of AI was in a dose-dependent manner with VU treatment (r=0.8419, P<;0.05). The MDA and GSH contents of 661W cells in VU-treated groups were significantly lower than the model group (P<;0.05). Compared with the model group, the SOD activity in the VU-treated groups (50, 100 and 200 µg/mL) was significantly higher (all P<;0.05). The Nrf2 and HO-1 mRNA expressions were slightly increased after irradiation, and obviously increased in 100 µg/mL VU-treated group. After irradiation, the relative expressions of HO-1 and Nrf2 proteins in nucleus were slightly increased (P<;0.05), and the changes in cytoplasm were not obvious, whereas it was significantly increased in both nucleus and cytoplasm in the VU treatment groups.@*CONCLUSIONS@#Anthocyanins extracted from VU could reduce apoptosis, stabilize cell membrane, and alleviate oxidant injury of mouse retinal photoreceptor 661W cells. The mechanism might be through activating Nrf2/HO-1 signal pathway and inducing HO-1 transcription and translation.

Effect of Traditional Chinese Medicine and Its Active Ingredients on Cardiovascular Disease Based on Nrf2/HO-1 Signaling Pathway / 中国实验方剂学杂志

Cardiovascular disease is the leading cause of death in China. Due to its great individual differences in genetic background, pathogenesis and disease development trend, the survival risk rate after standardized western medicine treatment under the guidance of the current guidelines remains high. Traditional Chinese medicine(TCM) has unique multiple-target, multiple-pathway and multiple-layer advantages, which can effectively make up for shortcomings of western medicine. Therefore, it has been widely used in the treatment of cardiovascular diseases. Oxidative stress is one of the important causes of cardiovascular diseases. Nuclear factor erythroid-2-related factor 2(Nrf2) is the central regulator of this reaction. When being activated, it can transfer to the nucleus and initiate signaling in the downstream pathway, thus playing an anti-oxidative stress role. As one of the most important endogenous protection systems in the body, the Nrf2/heme oxygenase-1 (Nrf2/HO-1) signaling pathway is the most classical approach for Nrf2 in playing roles. There have been certain achievements in studying and clarifying TCM by regulating this pathway to treat cardiovascular diseases using modern molecular biology and other methods. Based on this, this paper summarized the relationship between Nrf2/HO-1 signaling pathway and cardiovascular diseases, then concluded and analyzed the mechanism and pharmacological effects of TCM and its active ingredients in Nrf2/HO-1 signaling pathway on different cardiovascular diseases, involving active ingredients of TCM, TCM pairs active ingredients, TCM extracts and TCM formula. This paper provides a theoretical reference for the development and utilization of anti-cardiovascular drugs.