[Isolation of rabbit aqueous humor-derived exosomes and their immunosuppression function].

OBJECTIVE: To isolate exosomes from rabbit aqueous humor and to investigate their immunosuppression function. METHODS: Aqueous humor was collected from 40 New Zealand rabbits and exosomes were isolated by fractional separation and ultracentrifugation methods; the morphology was studied with electron microscopy. The immunosuppressive-related proteins of exosomes were detected with Western blotting; their inhibitory effect on ConA-induced proliferation of T lymphocyte was estimation with CCK-8 cells proliferation assay. RESULTS: Eight milliliters of aqueous humor were collected from 40 New Zealand rabbits and 200 µg exosomes was yielded. Under electron microscope, the exosomes had typical structure of lipid bi-layer with a diameter of 50-100 nm. The results of Western blotting showed that these exosomes expressed Hsp70, CD9 and Alix but not Grp94, presenting a typical exosomes protein profile. Moreover, exosomes expressed high level of TGF-ß and significantly inhibited the proliferation of T lymphocytes. CONCLUSION: Immunosuppressive exosomes can be isolated from rabbit aqueous humor, which may be involved in immunotolerance of the eye.

Anticancer, antioxidant and antimicrobial activities of the essential oil of Lycopus lucidus Turcz. var. hirtus Regel.

This study was designed to examine the anticancer, antioxidant and antimicrobial activities of the essential oil from Lycopus lucidus Turcz. var. hirtus Regel. The essential oil treatment to six human cancer cell lines resulted in a dose-dependent inhibition of cell growth. The cytotoxicity of the essential oil on liver carcinoma and breast cancer cell lines was significantly stronger than on other cell lines. The essential oil can induce apoptosis of the liver carcinoma cell line Bel-7402 and decrease the intracellular GSH level. The antioxidant effect of the essential oil was evaluated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical (OH) scavenging assays. The essential oil exhibited moderate antioxidant activity. The antimicrobial activity of the essential oil was evaluated against eight microorganisms using the disc diffusion and broth microdilution methods. The essential oil also showed moderate antimicrobial activity. These suggest that the essential oil could hold a good potential for use in the pharmaceutical industry.

Composition, antimicrobial activity and cytotoxicity of essential oils from Aristolochia mollissima.

The compositions of the essential oils from the rhizome and the aerial part of Aristolochia mollissima were analysed by GC-MS, 68 constituents (88.2% of the total oil) and 74 constituents (89.4% of the total oil) were identified, respectively. 2,2,7,7-Tetramethyltricyclo[6.2.1.0(1,6)]undec-4-en-3-one was the most abundant constituent among all in the ratios of 15.9% and 13.5% from the rhizome and the aerial part of A. mollissima, respectively. Among other main compounds, (E)-ß-santalol acetate (10.3%) and camphene (6.7%) were detected in the rhizome oil, spathulenol (6.8%) was detected in the oil from the aerial par of A. mollissima. The antimicrobial activity of the essential oils from the rhizome and the aerial part of A. mollissima was evaluated against 20 microorganisms using disc diffusion and broth microdilution methods. The gram-positive bacteria were more sensitive to both oils than gram-negative bacteria and yeasts. The rhizome oil showed the strongest bactericidal activity against Staphylococcus saprophyticus, whereas the oil from the aerial part of A. mollissima exerted the strongest bactericidal activity against methicillin-resistant and methicillin-senstive Staphylococcus aureus. The in vitro cytotoxicity of both oils on six human cancer cell lines were also examined. The cytotoxicity of the rhizome oil on four cancer cell lines (ACHN, Bel-7402, Hep G2 and HeLa) was significantly stronger than that of the oil from the aerial part of A. mollissima.

[Preparation of monoclonal antibodies against human mesenchymal stem cells].

OBJECTIVE: To prepare monoclonal antibodies (McAbs) against human mesenchymal stem cells (hMSCs) and to study their biological characteristics. METHODS: BALB/C mice were immunized with pooled hMSCs. McAbs were prepared by hybridoma technique and their biological characteristics were analyzed by indirect immunofluorescence, immunohistochemistry and flow cytometry. RESULT: Five hybridoma cell lines were successfully established, which secret McAbs specifically against hMSCs. Investigations showed that all these McAb reacted only to hMSCs and had no cross-reaction to other human cells, the relative affinities of 5 McAbs were 1x10(6) (ZUB1), 1x10(5) (ZUB4), 1x10(6) (ZUC3), ZUE12 (1x10(5)) and 1x10(5) (ZUF10), respectively. Isotype analysis showed that ZUB1, ZUE12, ZUF10 against the same isotype, while ZUC3, ZUB4 against other two different isotypes alone. Flow cytometric analysis showed that the positive expression rate of cultured hMSCs was 87.39% (ZUB1), 88.07% (ZUB4), 88.12% (ZUC3), 69.89% (ZUE12) and 83.67% (ZUF10). CONCLUSION: The prepared five McAbs can specifically react against hMSCs, which can be used for selection and study of hMCSs.

[Construction of recombinant plasmid containing mouse vasoactive intestinal peptide gene and its expression in COS-7 cells].

OBJECTIVE: To construct the eukaryotic expression plasmid containing mouse vasoactive intestinal peptide(VIP) gene with biological activities. METHODS: VIP cDNA including the sequences of signal peptide was cloned from mouse thymus by RT-PCR, and then inserted into the mammalian expression vector pcDNA3.1 between Hind III and EcoR I restriction sites. COS-7 cells were transfected with pcDNA3. 1-VIP using liposome, the expression of VIP was identified by Western blot and ELISA. Supernatant of transfected cell culture was added to LPS-stimulated macrophages and the TNF-alpha production in cell medium was observed by ELISA. RESULTS: The cloned VIP cDNA was confirmed by enzyme digestion and DNA sequencing. The expression of VIP was detected in the pcDNA3. 1-VIP transfected COS-7 cells by Western blot and ELISA. The VIP in culture supernatant potently inhibited TNF-alpha production by LPS-induced Macrophages in vitro. CONCLUSION: The eukaryotic expression plasmid that expresses biological active murine VIP has been constructed successfully.