Icariin protects vascular endothelial cells from oxidative stress through inhibiting endoplasmic reticulum stress.

OBJECTIVE: To investigate the protective effect and underlying mechanism(s) of icariin (ICA) in preventing hydrogen peroxide (H2O2)-induced vascular endothelial cell injury via endoplasmic reticulum stress (ERS). METHODS: To study the effects of ICA on H2O2-induced damage, we used the cell counting kit-8 assay to detect cell viability and the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay to determine cell adhesion and apoptosis, respectively. Spectrophotometry and enzyme-linked immunosorbent assay were used to measure the expression levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Subsequently, glucose-regulated protein 78 (GRP78), activating transcription factor-4 (ATF4) and eukaryotic initiation factor-2α (eIF2α) were detected using Western blotting. RESULTS: In human umbilical vein endothelial cells, different concentrations of ICA exhibited multiple effects, including reduced H2O2 damage, improved cell viability and adhesion, reduced cell apoptosis and increased SOD and GSH-Px activity. Among the ICA concentrations used, only the H2O2 + 100 µmol/L ICA group had significant differences compared to the H2O2 group. ERS activators H2O2 and dl-dithiothreitol (DTT) significantly increased GRP78, ATF4 and eIF2α expressions, decreased cell activity and reduced SOD and GSH-Px activity. In contrast, the H2O2 + 100 µmol/L ICA and H2O2 + 100 µmol/L ICA + DTT groups had significant inhibitory effects on the expressions of GRP78, ATF4 and eIF2α proteins, showing enhanced cell viability and SOD and GSH-Px activity. CONCLUSION: The results showed the dose-dependent effects of ICA against H2O2-induced injury in vascular endothelial cells. The inhibition of GRP78, ATF4 and eIF2α protein expressions in the ERS, and the subsequent alleviation of oxidative stress damage, might be the molecular mechanism.

[Expression of G-protein coupled estrogen receptor in the testis of the male mouse with kidney yin or kidney yang deficiency and its impact on the reproductive function of the mouse].

OBJECTIVE: To investigate the expression of the G-protein coupled estrogen receptor (GPER) in the testis of the male mouse with kidney yin or kidney yang deficiency and its influence on the reproductive function of the mouse. METHODS: We randomized 30 six-week-old male Kunming mice into three groups of equal number: kidney yang deficiency, kidney yin deficiency, and normal control, and established the models of kidney yang deficiency and kidney yin deficiency by peritoneal injection of hydrocortisone at 50 mg/kg for 5 days and 25 mg/kg for 10 days, respectively. We observed the behavioral changes of the mice using the elevated plus-maze, exhaustive swimming and field experiment, examined the semen quality with the automatic sperm quality analyzer, calculated the average number of the offspring, measured the serum testosterone (T) and estradiol (E2) levels and T/E2 ratio by Roche electrochemiluminescence assay, and determined the localization and expression of GPER in the testis by immunohistochemistry and immunofluorescence staining. RESULTS: Compared with the mice with kidney yin deficiency, those with kidney yang deficiency showed remarkably fewer entries into the open arm and central area (P <0.05) and shorter time of exhaustive swimming (P <0.05), but no statistically significant difference in the time spent in the open arm or the central area (P >0.05); the latter group also exhibited significant decreases in the epididymal sperm count (ï¼»7.27 ± 1.30ï¼½ vs ï¼»3.05 ± 1.06ï¼½ ×108/g, P <0.01), sperm motility (ï¼»54.15 ± 13.52ï¼½ vs ï¼»51.57 ± 8.75ï¼½ %, P <0.01) and average number of the offspring (6.46 vs 4.33, P <0.05), a slight increase in the rate of morphologically abnormal sperm (ï¼»13.42 ± 2.32ï¼½ vs ï¼»15.39 ± 2.48ï¼½ %, P >0.05), and markedly reduced serum T (ï¼»24.96 ± 6.18ï¼½ vs ï¼»16.72 ± 5.92ï¼½ ng/dl,P <0.05), E2 (ï¼»19.81 ± 4.01ï¼½ vs ï¼»15.24 ± 1.11ï¼½ pg/ml,P <0.05) and T/E2 ratio (1.41 vs 1.25, P <0.05). The expression of GPER was found in the cytoplasm of the Leydig cells, negative in the nuclei and cell membrane, significantly higher in the kidney yang than in the kidney yin deficiency group (P <0.05). CONCLUSIONS: The numbers of sperm and offspring decreased while the percentage of morphologically abnormal sperm increased in both the kidney yang and kidney yin deficiency mice, even more significantly in the former, which might be associated with the up-regulated expression of GPER in the testis of the mouse with kidney yang deficiency and consequently the reduced serum T level and T/E2 ratio.