TMT-Based Quantitative Proteomic Analysis Reveals the Crucial Biological Pathways Involved in Self-Incompatibility Responses in Camellia oleifera.

Camellia oleifera is a valuable woody oil plant belonging to the Theaceae, Camellia oil extracted from the seed is an excellent edible oil source. Self-incompatibility (SI) in C. oleifera results in low fruit set, and our knowledge about the mechanism remains limited. In the present study, the Tandem mass tag (TMT) based quantitative proteomics was employed to analyze the dynamic change of proteins response to self- and cross-pollinated in C. oleifera. A total of 6,616 quantified proteins were detected, and differentially abundant proteins (DAPs) analysis identified a large number of proteins. Combined analysis of differentially expressed genes (DEGs) and DAPs of self- and cross-pollinated pistils based on transcriptome and proteome data revealed that several candidate genes or proteins involved in SI of C. oleifera, including polygalacturonase inhibitor, UDP-glycosyltransferase 92A1-like, beta-D-galactosidase, S-adenosylmethionine synthetase, xyloglucan endotransglucosylase/hydrolase, ABC transporter G family member 36-like, and flavonol synthase. Venn diagram analysis identified 11 proteins that may participate in pollen tube growth in C. oleifera. Our data also revealed that the abundance of proteins related to peroxisome was altered in responses to SI in C. oleifera. Moreover, the pathway of lipid metabolism-related, flavonoid biosynthesis and splicesome were reduced in self-pollinated pistils by the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. In summary, the results of the present study lay the foundation for learning the regulatory mechanism underlying SI responses as well as provides valuable protein resources for the construction of self-compatibility C. oleifera through genetic engineering in the future.

Ethylacetate extract from Tetrastigma hemsleyanum inhibits proliferation and induces apoptosis in HepG2 and SMMC-7721 cells.

PURPOSE: This study aimed to investigate the effect of ethylacetate extract from Tetrastigma hemsleyanum (EET) on the proliferation and apoptosis of HepG2 and SMMC-7721 cells and determine the underlying mechanisms. MATERIALS AND METHODS: HepG2 and SMMC-7721 cells were cultured in vitro until the exponential growth phase and then treated with different concentrations of EET for 24 h. We performed a colony forming assay to determine colony forming ability, CCK8 assay to detect cell proliferation, Annexin V-FITC/PI double staining to analyze cell apoptosis, and Western blot to measure the protein expression of Caspase-3, Bcl-2, and Bax. RESULTS: EET significantly inhibited the proliferation of HepG2 and SMMC-7721 cells in a concentration- and time-dependent manner (P<0.05). After treatment with 0, 50, 100, 150, 200, and 250 µg/mL EET for 24 h, HepG2 the proliferation rates were 100.00%±0.00%, 90.33%±1.76%, 67.67%±0.88%, 47.33%±0.88%, 37.00%±0.00%, and 30.33%±0.67%, respectively, and 100.00%±0.00%, 18.25%±1.05%, 19.99%±0.59%, 23.42%±0.46%, 29.70%±0.79%, and 29.8%±0.41% for SMMC-7721 cells, respectively. After treatment with 0, 50, 100, 150, 200, and 250 µg/mL EET for 24 h, the apoptotic rates were 11.08%±0.72%, 27.44%±0.51%, 32.92%±0.41%, 26.20%±0.47%, 22.92%±0.24%, and 55.60%±0.08%, for HepG2 cells, respectively, and 59.18%±0.17%, 41.24%±2.05%, 52.54%±0.39%, 50.54%±1.08%, and 57.44%±1.93% for SMMC-7721 cells, respectively. Compared with the treatment groups, the control group showed a significantly lower apoptotic rate (47.91%±1.09%, P<0.05). EET at the different concentrations downregulated the protein expression of Caspase-3 in HepG2 cells and upregulated it in SMMC-7721 cells; it also downregulated the protein expression of Bcl-2 in HepG2 and SMMC-7721 cells and upregulated the protein expression of Bax in HepG2 and SMMC-7721 cells. CONCLUSION: These findings suggest that EET exerts antiproliferative and proapoptotic effects against HepG2 and SMMC-7721 cells mediated by downregulation or upregulation of Caspase-3 expression. Our study may help to develop EET for the pharmacological treatment of hepatoblastoma or hepatocellular carcinoma.