One-step purification and immobilization of thermostable ß-glucosidase on Na-Y zeolite based on the linker and its application in the efficient production of baohuoside I from icariin.

Baohuoside I, a minor flavonoid component of Herba Epimedii, has better bioactivities than its precursor compound icariin. In this work, we have fused the linker (4LP) to thermostable ß-glucosidase (Tpebgl3) and successfully prepared the immobilized enzyme (4LP-Tpebgl3@Na-Y) to produce baohuoside I from icariin. The activity recovery and maximum load of 4LP-Tpebgl3@Na-Y were 95.4% and 50.3 mg/g, respectively. Moreover, it exhibited four-fold improved adsorption selectivity (80.5%) with respect to native enzyme after immobilization. The maximum activity of 4LP-Tpebgl3@Na-Y was exhibited at 85 °C, pH 5.0, and it retained>80% of its initial activity after incubation at 75 °C for 2 h . It showed enhanced tolerance of organic solvent and glucose as compared to free enzymes. Kcat/Km value for 4LP-Tpebgl3@Na-Y was 1616.0 s-1•mM-1, which was 61.0% higher than that of free enzyme. Under suitable conditions (75 °C, pH 5.0, 0.1 U/mL enzyme and 120 min), 2000 mg/L icariin was transformed into baohuoside I with a molar conversion of 97.6%. 4LP-Tpebgl3@Na-Y retained 85.2% of its original activity after 10 cycles of reuse and the 768.8 mg/L/h total productivity of baohuoside I was obtained. This is the first research on one-step purification and immobilization of thermostable ß-glucosidase based on the linker and its application in the efficient production of baohuoside I from icariin.

Cancer-associated fibroblasts attenuate Cisplatin-induced apoptosis in ovarian cancer cells by promoting STAT3 signaling.

One of the main reasons for treatment failure in ovarian cancer is acquired drug resistance. Cancer associated fibroblasts (CAFs) are known to enhance chemoresistance in many human tumors. However, its contributions to chemoresistance acquisition in ovarian cancer are not well understood. Here, we provide the first evidence that the conditioned medium of CAFs (CAFs-CM) could attenuate the sensitivity to Cisplatin in A2780 and ES2 ovarian cancer cells and protect them from Cisplatin-induced apoptosis. We found the expression level of two anti-apoptotic proteins, Bcl-2 and Survivin, as well as their upstream controller p-STAT3 were significantly increased when ovarian cancer cells were exposed to CAFs-CM. Furthermore, inhibition of STAT3 signaling with Cryptotanshinone could down-regulate the expression of Bcl-2 and Survivin, thus weaken the post-target resistance to Cispaltin mediating by CAFs-CM in ovarian cancer cells. In conclusion, our data suggested that CAFs could activate the anti-apoptotic STAT3 signaling, thereby decrease the Cisplatin-induced apoptosis and promote chemoresistance in ovarian cancer.

Linker-peptide-mediated one-step purification and immobilization of α-L-rhamnosidase from Bacteroides thetaiotaomicron for direct biotransformation from epimedin C to icariin.

Icariin, the most effective bioactive component in Epimedium, is also the index component of Epimedium quality control in Pharmacopoeia. It was a very attractive approach for bioconversion from epimedin C to icariin. However, its potential was impeded by poor stability and non-recyclable properties of free enzymes. In this study, we have fused the linker (4LP) to α-L-rhamnosidase BtRha and successfully prepared the immobilized enzyme (incubated 4LP-BtRha@Na-Y) to produce icariin from epimedin C. The activity recovery of 4LP-BtRha@Na-Y was 79.6 %, and enzyme activity was 209.8 U/g, which was 1.75-fold and 1.6-fold higher than that of immobilized BtRha (BtRha@Na-Y), respectively. The optimal reaction temperature and pH of 4LP-BtRha@Na-Y was 55 °C and 6.5, respectively. The thermal stability of immobilized enzyme was significantly improved by incubation in phosphate buffer containing 20 % glycerol and 10 % fructose. The kcat/Km value of incubated 4LP-BtRha@Na-Y was 7.98 × 105 s-1M-1, which increased by 8 % compared with free BtRha. Finally, under suitable conditions, 1 g/L epimedin C was transformed into icariin with icariin yield 75.1 %, and the relative conversion rate retained 74.9 % after reused 13 cycles. This experiment provides a new idea for one-step purification and immobilization of α-L-rhamnosidase for direct biotransformation from epimedin C to icariin, which will have great prospects in food and pharmaceutical production.

Collagen triple helix repeat containing 1 (CTHRC1) activates Integrin ß3/FAK signaling and promotes metastasis in ovarian cancer.

BACKGROUND: Metastasis is the major cause of morbidity and mortality in patients with epithelial ovarian cancer (EOC), however the mechanisms that underline this process are poorly understood. Collagen triple helix repeat containing-1 (CTHRC1) is a 28-kDa secreted protein reported to be involved in vascular remodeling, bone formation and morphogenesis. This study aimed to investigate the role of CTHRC1 in promoting the metastasis of EOC and to elucidate the underlying molecular mechanisms. METHODS: The biologic functions of CTHRC1 in metastasis were validated both in vivo and in vitro experiments. The phosphor-antibody microarray analysis and Co-immunoprecipitation were performed to detect and identify the integrin ß3/FAK signaling pathway that mediated the function of CTHRC1. Seventy two EOC samples were analyzed for association between CTHRC1/integrin ß3 expression and patient clinicopathological features. RESULTS: We demonstrated that CTHRC1 enhances the biological behavior of EOC including cell migration, invasion, as well as its adhesion capability to cell-extracellular matrix in vitro. Additionally, CTHRC1 promoted metastatic spread of EOC cells in an i.p. ovarian xenograft model and this phenotype was primarily ascribed to the activation of integrin/FAK signaling. Mechanistically, we determined that FAK were phosphorylated on Tyr397, and were activated by integrin ß3, which is important for the CTHRC1-mediated migratory and invasive ability of EOC cells in vitro and i.p. metastasis. In addition, we found that attenuated CTHRC1/integrin ß3 expression predicted a poor prognostic phenotype and advanced clinical stage of EOC. CONCLUSIONS: Our results suggest that CTHRC1, a newly identified regulator of i.p. metastasis through activation of integrin ß3/FAK signaling in EOC, may represent a potential therapeutic target for ovarian cancer.