Missing and overexpressing proteins in domestic cat oocytes following vitrification and in vitro maturation as revealed by proteomic analysis.

BACKGROUND: The domestic cat serves as an animal model for assisted reproductive studies of endangered felid species. To date, there are no data on the protein alterations following cryopreservation of oocytes in felid family. METHODS: Immature (germinal vesicle) domestic cat oocytes were vitrified in the vitrification solution containing 35% ethylene glycol, 20% DMSO and 0.5 mM sucrose. The vitrified-warmed oocytes were matured (metaphase II) in vitro and subjected to proteomic analysis using 1DE SDS-PAGE prefractionation combined with LC-MS/MS. RESULTS: A total of 1712 proteins were identified in in vitro matured oocytes. Of the 1712 proteins, 1454 proteins were found in both groups, whereas, 258 proteins were differentially expressed between control and vitrified-warmed groups. In vitrified-warmed oocytes, the missing proteins were membrane and nuclear proteins; whereas, apoptosis and DNA repair proteins were overrepresented. CONCLUSIONS: The identified missing and overexpressed proteins in vitrified-warmed oocytes represent potential markers of cryoinjuries and the developmental pathways of oocytes. The findings of differential expressed proteins may contribute to effective ways of proteome analysis of oocyte/embryo quality in order to assess safety of cryopreservation in felid species.

Impairment of CD4+CD25+ regulatory T cells in C4-deficient mice.

OBJECTIVE: To investigate the association between deficiencies of early components in the classical complement pathway and the development of SLE. METHODS: Forty inbred C57BL/6J mice and 40 knockout C4 complement gene (C4KO) mice, which included 10 mice in each age group (2, 4, 6, and 8 months) were used. The enumeration of CD4+CD25+ Tregs frequencies in bone marrow, spleen and peripheral blood from both normal and C4KO groups were performed by flow cytometry. The expression levels of Foxp3 and TGF-beta in the same tested tissues were measured using real time PCR. The antinuclear antibodies (ANA) were semi-quantitatively measured using ELISA. RESULTS: We report decreased frequencies of CD4+CD25+ Tregs and reduced expression levels of Foxp3 and TGF-beta, which efficiently program the development and function of Tregs, in lymphoid tissues and peripheral blood of C4KO mice. In this study, C4KO mice have higher titers of ANA than those of normal mice. Higher frequencies of mice positive for ANA are also found in older mice. CONCLUSIONS: The deficiency of the C4 gene induces the decreased numbers of Tregs that further increase the production of ANA resulting in the development of an autoimmune disorder. The outcomes of our study help us to understand the association between the deficiency of C4 in the classical complement pathway and development of autoimmune disorder via the role of Tregs.

Effects of vitrification on nuclear maturation, ultrastructural changes and gene expression of canine oocytes.

BACKGROUND: Cryopreservation of oocytes, which is an interesting procedure to conserve female gametes, is an essential part of reproductive biotechnology. The objective of the present study was to investigate the effects of vitrification on nuclear maturation, ultrastructural changes and gene expression of canine oocytes. METHODS: Immature oocytes (germinal vesicles) isolated from ovaries of normal bitches (> 6 months of age) were either vitrified in open pulled straw (OPS) using 20% ethylene glycol (EG) and 20% dimethyl sulfoxide (DMSO) as vitrification solution or exposed to vitrification solution without subjected to liquid nitrogen. After warming, oocytes were investigated for nuclear maturation following in vitro maturation (IVM), ultrastructural changes using transmission electron microscopy (TEM) and gene expression using RT-PCR. Fresh immature oocytes were used as the control group. RESULTS: The rate of resumption of meiosis in vitrified-warmed oocytes (53.4%) was significantly (P < 0.05) lower than those of control (93.8%) and exposure (91.4%) groups. However, there were no statistically significant differences among groups in the rates of GV oocytes reaching the maturation stage (metaphase II, MII). The ultrastructural alterations revealed by TEM showed that cortical granules, mitochondria, lipid droplets and smooth endoplasmic reticulum (SER) were affected by vitrification procedures. RT-PCR analysis for gene expression revealed no differences in HSP70, Dnmt1, SOD1 and BAX genes among groups, whereas Bcl2 was strongly expressed in vitrified-warmed group when compared to the control. CONCLUSION: Immature canine oocytes were successfully cryopreserved, resumed meiosis and developed to the MII stage. The information obtained in this study is crucial for the development of an effective method to cryopreserve canine oocytes for establishment of genetic banks of endangered canid species.

Effect of human beta-globin bacterial artificial chromosome transgenesis on embryo cryopreservation in mouse models.

The purpose of the present study was to investigate the efficiency of embryo cryopreservation for four transgenic (TG) thalassaemic mouse strains, which is a key element of the ongoing gene banking efforts for these high-value animals. Heterozygous TG embryos were produced by breeding four lines of TG males to wild-type (WT) females (C57BL/6J). Intact two-cell embryos were cryopreserved by vitrification in straws using 35% ethylene glycol. Survival rates of cryopreserved embryos ranged between 91.1% (102/112) and 93.6% (176/188) without significant differences between the lines. In contrast, the paternal line had a significant effect on the development of these embryos to the blastocyst stage, which ranged from 50.6% (92/182) to 77.5% (79/102). This effect was also noted following embryo transfers, with implantation rates varying from 17.3% (19/110) to 78.1% (35/45). The results demonstrate that the in vivo developmental potential is significantly influenced by TG line and reveal a specific line effect on cryosurvival. All bacterial artificial chromosome transgenic fetuses developed from vitrified-warmed embryos showed expression of the human beta-globin transgene. In conclusion, the present study shows a strong TG line effect on developmental competence following cryopreservation and the vitrification method was successful to bank the human beta-globin TG-expressing mouse strains.

Successful artificial insemination in the Asian elephant (Elephas maximus) using chilled and frozen-thawed semen.

BACKGROUND: Artificial insemination (AI) using frozen-thawed semen is well established and routinely used for breeding in various mammalian species. However, there is no report of the birth of elephant calves following AI with frozen-thawed semen. The objective of the present study was to investigate the fertilizing ability of chilled and frozen-thawed semen in the Asian elephant following artificial insemination (AI). METHODS: Semen samples were collected by from 8 bulls (age range, 12-to 42-years) by manual stimulation. Semen with high quality were either cooled to 4 degrees C or frozen in liquid nitrogen (-196 degrees C) before being used for AI. Blood samples collected from ten elephant females (age range, 12-to 52-years) were assessed for estrus cycle and elephants with normal cycling were used for AI. Artificial insemination series were conducted during 2003 to 2008; 55 and 2 AI trials were conducted using frozen-thawed and chilled semen, respectively. Pregnancy was detected using transrectal ultrasonography and serum progestagen measurement. RESULTS: One female (Khod) inseminated with chilled semen became pregnant and gave birth in 2007. The gestation length was 663 days and the sex of the elephant calf was male. One female (Sao) inseminated with frozen-thawed semen showed signs of pregnancy by increasing progestagen levels and a fetus was observed for 5 months by transrectal ultrasonography. CONCLUSION: This is the first report showing pregnancy following AI with frozen-thawed semen in the Asian elephant. Successful AI in the Asian elephant using either chilled or frozen-thawed semen is a stepping stone towards applying this technology for genetic improvement of the elephant population.

Proteome profiling of bovine follicular fluid-specific proteins and their effect on in vitro embryo development.

The objective of this study was to determine the effect of bovine follicular fluid proteins (bFF) and their differently charged groups as maturation media supplements for in vitro embryo development. bFF was obtained by aspiration from large healthy follicles (4-10 mm in diameter) and was precipitated by 30-50% (NH4)2SO4. The precipitated protein was fractionated into basic and acidic fractions by ion-exchanger columns. In experiment 1, the oocytes were matured in TCM-199 with 1) FBS+hormones (control) and 2) 10% bFF. The oocyte maturation rate, the development to the blastocyst stage rate and blastocyst cell number were not significantly different between the groups. However, the INFα and IGF-2r expression levels in the 10% bFF were higher than in the control (P<0.05). In experiment 2, the specific charge proteins of bFF (basic and acidic) were also used as media supplements in the maturation medium. The basic fraction had higher oocyte maturation rate and blastocyst cell number when compared with addition of acidic fraction (P<0.05). The expression levels for almost all developmentally important genes in the basic fraction were greater than those in the acidic fraction, particularly INFα (P<0.05). Most of the protein in the basic fraction was associated with the immune response and mRNA processing. In conclusion, supplementation of 10% bFF alone in maturation medium can support oocyte maturation and embryo development. The basic fraction in bFF seemed to have effect on oocyte maturation rate and blastocyst cell number.

The scorpion venom peptide BmKn2 induces apoptosis in cancerous but not in normal human oral cells.

AIM: This study aimed to investigate the mechanism of the induction of apoptosis of human oral cancer cells by the scorpion venom peptide BmKn2. METHODS: Human oral squamous carcinoma cells (HSC4), mouth epidermoid carcinoma cells (KB), human normal gingival cells (HGC) and dental pulp cells (DPC) were treated with BmKn-2 peptide for 24h. Cell viability was determined by the MTT assay. Apoptosis was assessed using phase contrast microscopy, by propidium iodide (PI) staining to assess nuclear morphology and by Annexin V staining. Apoptotic signaling pathways were investigated by quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and Western blotting. RESULTS: BmKn-2 showed potent cytotoxic effects towards both HSC4 and KB cells with the associated induction of apoptosis. The cells showed distinct morphological changes, nuclear disintegration and an increase in the number of Annexin V-positive cells. Interestingly, at concentrations which kill cancerous cells, BmKn-2 did not affect cell viability or mediate the induction of apoptosis in normal HGC or DPC. Induction of apoptosis by BmKn-2 in HSC4 and KB cells was associated with the activation of tumor suppress p53. Pro-apoptotic BAX expression was increased, whereas antiapoptotic BCL-2 expression was decreased in BmKn-2 exposed HSC4 and KB cells. BmKn-2 treated-oral cancer cells showed distinct upregulation of initiator caspase-9, with no effect on caspase-8 expression. Increased expression levels of executor caspases-3 and -7 were also found in treated cells for both oral cancers. CONCLUSION: This study has suggested for the first time that BmKn-2 exerts selective cytotoxic effects on human oral cancer cells by inducting apoptosis via a p53-dependent intrinsic apoptotic pathway. BmKn-2 peptide originally derived from a natural source shows great promise as a candidate treatment for oral cancer, with minimal effects on healthy tissue.

The in vitro quality of frozen-thawed Asian elephant (Elephas maximus) spermatozoa in semen supplemented with Equex STM paste and oxytocin during and after cryopreservation.

The effects of Equex STM paste (Equex) and oxytocin (OT) on the in vitro quality of frozen-thawed Asian elephant sperm were investigated in the study. The viability of frozen-thawed sperm was significantly higher in the Equex-treated (1 and 2%) groups than in the control group. There were no differences in the examined sperm parameters among the control and OT-treated (0.05-5IU) groups.

Missing and overexpressing proteins in domestic cat oocytes following vitrification and in vitro maturation as revealed by proteomic analysis

BACKGROUND: The domestic cat serves as an animal model for assisted reproductive studies of endangered felid species. To date, there are no data on the protein alterations following cryopreservation of oocytes in felid family. METHODS: Immature (germinal vesicle) domestic cat oocytes were vitrified in the vitrification solution containing 35% ethylene glycol, 20% DMSO and 0.5 mM sucrose. The vitrified-warmed oocytes were matured (metaphase II) in vitro and subjected to proteomic analysis using 1DE SDS-PAGE prefractionation combined with LC-MS/MS. RESULTS: A total of 1712 proteins were identified in in vitro matured oocytes. Of the 1712 proteins, 1454 proteins were found in both groups, whereas, 258 proteins were differentially expressed between control and vitrified-warmed groups. In vitrified-warmed oocytes, the missing proteins were membrane and nuclear proteins; whereas, apoptosis and DNA repair proteins were overrepresented. CONCLUSIONS: The identified missing and overexpressed proteins in vitrified-warmed oocytes represent potential markers of cryoinjuries and the developmental pathways of oocytes. The findings of differential expressed proteins may contribute to effective ways of proteome analysis of oocyte/embryo quality in order to assess safety of cryopreservation in felid species.