C-kit signaling promotes human pre-implantation 3PN embryonic development and blastocyst formation.

BACKGROUND: Although in vitro culture system has been optimized in the past few decades, the problem of few or no high quality embryos has been still not completely solved. Accordingly, fully understanding the regulatory mechanism of pre-implantation embryonic development would be beneficial to further optimize the in vitro embryo culture system. Recent studies have found the expression of c-kit in mouse embryo and its promotion effects on mouse embryonic development. However, it is unclear the expression, the role and the related molecular regulatory mechanism of c-kit in human pre-implantation embryo development. Therefore, the present study is to determine whether c-kit is expressed in human pre-implantation embryos, and to investigate the possible regulatory mechanism of c-kit signaling in the process of embryonic development. METHODS: The present study includes human immature oocytes and three pronucleus (3PN) embryos collected from 768 women (28-32 ages) undergoing IVF, and normal 2PN embryos collected from ICR mice. Samples were distributed randomly into three different experimental groups: SCF group: G-1™ (medium for culture of embryos from the pro-nucleate stage to day 3) or G-2™ (medium for culture of embryos from day3 to blastocyst stage) + HSA (Human serum album) solution + rhSCF; SCF + imanitib (c-kit inhibitor) group: G-1™ or G-2™ + HSA solution + rhSCF + imanitib; SCF + U0126 (MEK/ERK inhibitor) group: G-1™ or G-2™ + HSA solution + rhSCF + U0126; Control group: G-1™ or G-2™ + HSA solution + PBS; The rate of good quality embryos at day 3, blastulation at day 6 and good quality blastulation at day 6 were analysis. RT-PCR, western blot and immunofluorescence staining were applied to detect the target genes and proteins in samples collected from human or mice, respectively. RESULTS: c-kit was expressed ubiquitously in all human immature oocytes, 3PN embryos and 3PN blastocysts. In the experiment of human 3PN embryos, compared with other groups, SCF group showed obviously higher rate of good quality at day 3, better rate of blastocyst formation at day 6 and higher rate of good quality blastocyst formation at day 6. Furthermore, we observed a higher ETV5 expression in SCF group than that in other groups. Similar results were also found in animal experiment. Interestingly, we also found a higher phosphorylation level of MEK/ERK signal molecule in mice embryos from SCF group than those from other groups. Moreover, inhibition of MEK/ERK signaling would remarkably impeded the mice embryonic development, which might be due to the reduced ETV5 expression. CONCLUSIONS: The present study firstly revealed that c-kit signaling might promote the human pre-implantation embryonic development and blastocyst formation by up-regulating the expression of ETV5 via MEK/ERK pathway. Our findings provide a new idea for optimizing the in vitro embryo culture condition during ART program, which is beneficial to obtain high quality embryos for infertile patients.

Rapid determination of carbendazim in complex matrices by electrospray ionization mass spectrometry with syringe filter needle.

The determination of pesticide residues is an indispensable task in controlling food safety and environment protection. Carbendazim is one of the extensive uses of pesticides in the agricultural industry. In this study, a simple method utilizing syringe filter has been applied as electrospray ionization emitter for mass spectrometric identification and quantification of carbendazim in complex matrices including soil, natural water, and fruit juice samples, which contain many insoluble materials. With online syringe filter of the complex samples, most of insoluble materials such as soil were excluded in spray ionization process due to the filter effect, and analytes were subsequently sprayed out from syringe needle for mass spectrometric detection. The pore sizes of filters and diameters of syringe needles also were investigated. The analytical performances, including the linear range (1-200 ng·mL-1 ), limit of detection (0.2-0.6 ng·mL-1 , S/N > 3), limit of quantitation (3.5-8.6 ng·mL-1 , S/N > 10), reproducibility (6.4%-12.5%, n = 6), and recoveries (72.1%-91.0%, n = 6) were well acceptable for direct analysis of raw samples. Matrix effect for detection of carbendazim in soil samples also was experimentally investigated. This study demonstrated that syringe filter needle coupled with electrospray ionization mass spectrometry is a simple, efficient, and sensitive method for detection of pesticide residues in water, soil, and fruit juice for risk assessment.

Quantification of monohydroxylated polycyclic aromatic hydrocarbons in human urine samples using solid-phase microextraction coupled with glass-capillary nanoelectrospray ionization mass spectrometry.

Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants with carcinogenic effect raising worldwide concerns. Hydroxylated PAHs (OH-PAHs) could be formed in the body as metabolites of PAHs in human urine samples and thus considered as biomarkers of PAH exposure. In this study, five OH-PAHs including 3-phenanthrol, 1-naphthol, 2-hydroxy fluorene, 1-hydroxprene and 6-hydroxy chrysene in human urine samples were selectively enriched by C18 solid-phase microextraction (SPME), then SPME fiber was connected high voltage and then was inserted into a glass-capillary to elute and ionize the analytes for mass spectrometric (MS) detection. The coupling of SPME-MS showed excellent analytical performance for detection of urinary OH-PAHs under optimal conditions, providing an easy operation for rapid detection of a single sample within minutes. By use of internal standard (i.e., 2-hydroxy fluorene-d9), the limit of detection (LOD) and limit of quantitation (LOQ) of OH-PAHs were found to be less than 0.05 ng L-1 level (S/N > 3) and less than 0.1 ng L-1 level (S/N > 10), respectively. The dynamic ranges of five OH-PAHs were found to be a range at 0.1-5.0 ng L-1 with excellent coefficient (R2 > 0.99). This method also showed good precisions (intra-day: 3.4-5.5%, inter-day: 7.0-9.8%, n = 5) and good accuracy (85.3-95.3%, n = 5). Moreover, ion suppression and matrix effect in detection of OH-PAHs in urine were also investigated. Human urine samples collected from 12 volunteers including 6 non-smokers and 6 smokers have been successfully analyzed, it was found that individual OH-PAHs in smokers were higher than in non-smokers. This study demonstrated that SPME coupled with glass-capillary nanoESI-MS is a sensitive method for rapid detection of urinary OH-PAHs for health risk assessment of PAHs exposure.

[Efficiency improvement of fully automatic microcolumn glass sphere technology used in blood group compatibility tests].

The purpose of this study was to determine whether the fully automated ORTHO AutoVue Innova system, which based on the microcolumn glass sphere technology, is accurate enough to meet immunohematology testing needs at blood banks. 16 IgM anti-C, anti-c, anti-D, anti-E and anti-e dilution series were tested respectively, with corresponding antigen positive red blood cell solutions, by ORTHO AutoVue Innova system and saline medium test. 16 IgG anti-D dilution series were tested respectively with RhD positive red blood cell solutions by ORTHO AutoVue Innova system, polybrene test and antiglobulin test. The accuracies of microcolumn glass sphere technology were analysed, by comparing to the reference assays. The results showed that the sensitivities of the ORTHO AutoVue Innova tests were 1:69.8, 1:33.4, 1:1448.1, 1:139.6 and 1:32.0 for IgM anti-C, anti-c, anti-D, anti-E and anti-e respectively; the corresponding value of saline medium tests were 1:16.7, 1:16.6, 1:430.5, 1:34.9 and 1:9.9. There were statistically significant differences between the groups of each tests (t values were 14.38, 5.48, 10.25, 12.65 and 9.59 for IgM anti-C, anti-c, anti-D, anti-E and anti-e respectively, p < 0.05). For IgG anti-D, the sensitivities of the ORTHO AutoVue Innova test, polybrene test and antiglobulin test were 1:980.6, 1:181.0 and 1:304.4 respectively. There was statistically significant difference among the 3 groups (F = 51.15, p < 0.01). It is concluded the use of ORTHO AutoVue Innova system for blood group compatibility test can obtain more accurate results than traditional tube tests, it is reliable and safe for routine tests performed in immunohematology laboratories.