Progress of studies on anti-breast tumor mechanism of alkaloids / 中国中药杂志

Breast tumor has become one of the malignant tumors with the highest incidence, and is a serious threat to human health, especially to women. Chemotherapy is an important anti-breast tumor therapy, which can be used in almost every stage of breast tumor therapy alone or in the combination with surgery and radiation therapy. Alkaloids are a kind of ubiquitous natural products, and important active components of various medicinal plants. A large number of studies have shown that alkaloids could exert an anti-breast tumor effect by inhibiting proliferation, metastasis and angiogenesis, resisting mitosis, promoting apoptosis and autophagy, and triggering cell cycle arrest. The extensive anti-breast tumor effect makes alkaloids an important candidate drug source. This paper reviews the anti-breast tumor mechanism of natural products of alkaloids.

The role of human lysozyme-like protein 4 in fertilization and its enzymatic properties / 中华男科学杂志

Objective@#To elucidate the possible role of human lysozyme-like protein 4 (LYZL4) in fertilization and characterize its enzymatic properties.@*METHODS@#The localization of LYZL4 in human spermatozoa was investigated by immunofluorescence staining, the sources of LYZL4 on the sperm surface examined by RT-PCR, and the role of LYZL4 in fertilization assessed by the zona-free hamster egg penetration test. The recombinant plasmid pPIC9K-LYZL4 was constructed and its expression induced with methanol after transformed into competent Pichia pastoris GS115. The recombinant LYZL4 protein (rLYZL4) was purified from the fermentation supernatant and subsequently identified by Western blot. The hyaluronan binding ability of rLYZL4 was determined by ELISA and the muramidase activity, hyaluronidase activity, and free radical scavenging ability examined by spectrophotometric methods.@*RESULTS@#Immunodetection with a specific antiserum localized LYZL4 on the acrosomal membrane of mature spermatozoa, which was exclusively secreted from the testis and epididymis as shown by RT-PCR. Immunoneutralization of LYZL4 significantly decreased the number of human spermatozoa bound to zona-free hamster eggs in a dose-dependent manner in vitro. The recombinant protein was expressed successfully by the P. pastoris strain GS115. Purified rLYZL4 exhibited a potent hyaluronan binding ability and a strong free radical scavenging ability but no muramidase or hyaluronidase activity.@*CONCLUSIONS@#LYZL4 secreted from the testis and epididymis is localized on the acrosomal membrane of mature spermatozoa and plays a role in sperm-egg binding as well as in binding hyaluronan and scavenging free radicals, which suggests that it might be a multi-functional molecule contributive to sperm protection and sperm-egg binding.

The study on the features of dopamine secretion in microencapsulated cells of bovine retinal pigmentary epithelial cells in vitro / 中华老年医学杂志

ObjectiveTo detect the features of dopamine secretion of cultured bovine retinal pigmentary epithelial(RPE) cells. The level of dopamine and survival rate after passage and microencapsulation were also observed. MethodsThe primary culture of bovine RPE cells was made using enzyme digestion. After purification and identification the growth curve of the cell was observed. Alginate-polylysine-alginate(APA) microencapsulated cells were made with a high voltage electostatic system. The activity of the cells in the mirocapsule was investigated by trypan blue staining. The secretion of dopamine was determined by high performance liquid chromatography (HPLC) assay. ResultsThe cell had high purity of immunocytochemistry. The growth curve showed that the exponential growth occurred at the first 1~4 days. Dopamine content was first detected at the time point of 2 hour, and arrived at the peak at about 48 hour of the cultivation. The secretion of dopamine was not different between passages. Dopamine secretion was dramatically decreased in the first 4 days after microencapsulation (P