Tubulin-folding cofactor E deficiency is associated with vascular dysfunction and endoplasmatic reticulum stress of vascular smooth muscle cells

Introduction

Endothelial function assessed via flow mediated dilatation (FMD) has shown to predict risk in individuals with established cardiovascular diseases, whereas its predictive value is uncertain in the setting primary prevention.

Purpose

The aim of the current work was to discover and evaluate novel mediators of vascular dysfunction in the general population and in conditional knock-out transgenic animal models.

Methods

In order to identify novel targets that were negatively correlated with FMD and investigate their contribution in vascular function, a Genome Wide Association Study (GWAS) of 5,000 participants was performed and subsequently immune cell-, endothelial- and vascular smooth muscle cell (VSMCs)-targeted conditional knockout mouse models were generated and characterized.

Results

GWAS analysis revealed that single nucleotide polymorphisms (SNPs) in the tubulin folding cofactor E (TBCE) gene were negatively correlated with FMD and TBCE expression in the peripheral blood mononuclear cells (PBMCs). Myelomonocytic cell-targeted TBCE deficiency did not lead to any vascular dysfunction in vivo in the LysM+Cre+/−TBCEfl/fl mice. Endothelial-targeted TBCE deficiency led to an NLR family pyrin domain containing 3 (NLRP3)-dependent activation of the inflammasome in the endothelial cells of Tie2-ERT2Cre+/−TBCEfl/fl mice. Importantly, VSMC-targeted TBCE deficiency was associated with endothelial dysfunction, increased aortic wall thickness and endoplasmatic reticulum (ER) stress-mediated VSMC hyperproliferation in vivo (SMMHC-ERT2Cre+/−TBCEfl/fl), paralleled by calnexin upregulation. Administration of the blood pressure hormone angiotensin II exacerbated the vascular dysfunction and phenotype. Administration of the ER stress modulator tauroursodeoxycholic acid to the SMMHC-ERT2Cre+/−TBCEfl/fl mice reversed vascular dysfunction, paralleled by induction of Raptor/Beclin-1-dependent autophagy both in vitro and in vivo.

Conclusion

TBCE and tubulin homeostasis in the vascular musculature seem to be novel markers of vascular function and represent a new druggable target for the treatment of ER-stress-mediated vascular dysfunction.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): This work was supported by grants of the German Federal Ministry for Education and Research (BMBF01EO1003 and BMBF01EO1503), the DFG Major Research Instrumentation Programme (DFG INST 371/47-1 FUGG) as well as the Boehringer Ingelheim Foundation. PW received funds from the German Research Foundation in support of his work (DFG WE4361-4-1 and WE 4361/7-1). KS, TM and PW are PIs of the DZHK.

Quality parameters and fertility of ram semen cryopreserved in egg yolk and soybean lecithin supplemented extenders

The aim of the study was to investigate the effect of soybean lecithin as a substitute for egg yolk in milk and tris based extenders in ram semen cryopreservation. Twenty ejaculates were col- lected from four healthy, mature Wrzosówka rams (2-3 years of age). Each ejaculate was divided into four equal aliquots and diluted with four different extenders: 1) milk extender containing 5% egg yolk, 2) milk extender containing 1.5% soybean lecithin, 3) tris extender containing 20% egg yolk, 4) tris extender containing 1.5% soybean lecithin. Extended semen was loaded into 0.25 ml French straws, cooled and frozen in liquid nitrogen vapor. Total motility, curvilinear velocity, plasma membrane integrity and fertilizing ability of sperm were assessed after thawing. Total mo- tility was lower (p⟨0.05) in tris-soybean lecithin extender when compared to other extenders. Curvilinear velocity was higher (p⟨0.05) for spermatozoa cryopreserved in milk-soybean lecithin extender compared to other extenders tested. For the percentage of live sperm no significant difference was observed between extenders. The lambing rate were higher (not statistically signifi- cant) in ewes inseminated with semen doses frozen in milk-soybean lecithin extender (42.9%) than in the tris-egg yolk extender (16.7%). In conclusion, replacing the egg yolk with soybean lecithin was effective in milk but not in tris extender.

The medium- and long-term outcome of total shoulder arthroplasty for primary glenohumeral osteoarthritis in middle-aged patients

Aims

Promising medium-term results from total shoulder arthroplasty (TSA) have been reported for the treatment of primary osteoarthritis in young and middle-aged patients. The aim of this study was to evaluate the long-term functional and radiological outcome of TSA in the middle-aged patient.

Patients and Methods

The data of all patients from the previous medium-term study were available. At a mean follow-up of 13 years (8 to 17), we reviewed 21 patients (12 men, nine women, 21 shoulders) with a mean age of 55 years (37 to 60). The Constant-Murley score (CS) with its subgroups and subjective satisfaction were measured. Radiological signs of implant loosening were analysed.

Results

Two shoulders (two patients) were revised and in two shoulders of two different patients, revision surgery was recommended. The mean CS increased from 23.3 (10 to 45) pre-operatively to 56.5 (26 to 81; p < 0.0001), but with a decrease in CS from 62.8 (38 to 93) to 56.5 (26 to 81) between medium- and long-term follow-up (p = 0.01). Without revision surgery, 18 patients (95%) rated their result as good or very good. The mean radiolucent line score for the glenoid components increased from 1.8 (0 to 6) to 8.2 (2 to 18) between medium- and long-term follow-up (p < 0.001).

Conclusion

TSA in young and middle-aged patients leads to improvement in clinical function and a relatively high satisfaction rate. However, clinical or radiological glenoid loosening worsens in the long term. Further studies are needed to optimise the treatment options in this patient population. Cite this article: Bone Joint J 2017;99-B:939–43.

Factors influencing quality of anticoagulation control and warfarin dosage in patients after aortic valve replacement within the 3 months of follow up

Warfarin dosage estimation using the pharmacogenetic algorithms has been shown to improve the quality of anticoagulation control in patients with atrial fibrillation. We sought to assess the genetic, demographic and clinical factors that determine the quality of anticoagulation in patients following aortic valve replacement (AVR). We studied 200 consecutive patients (130 men) aged 63 ± 12.3 years, undergoing AVR, in whom warfarin dose was established using a pharmacogenetic algorithm. The quality of anticoagulation within the first 3 months since surgery was expressed as the time of international normalized ratio (INR) in the therapeutic range (TTR). The median TTR in the entire cohort was 59.6% (interquartile range, 38.7 - 82.7). Ninety-nine (49.5%) patients with TTR ≥ 60% did not differ from those with poor anticoagulation control (TTR < 60%) with regard to demographic and cardiovascular risk factors. Coronary artery disease (n = 84, 42%) and previous stroke (n = 5, 2.5%) predicted higher TTR, while possession of CYP2C9*2 variant allele (n = 49, 25%) was associated with lower TTR (P = 0.01). In turn, VKORC1 c.-1639A, CYP2C9*2 and *3 variants were independently associated with actual warfarin dose (P < 0.0001). In AVR patients better anticoagulation control is observed in patients with coronary artery disease and history of stroke, which might result in part from previous lifestyle modification and therapy. Possession of CYP2C9*2 and/or CYP2C9*3 allele variants is associated with lower TTR values and warfarin dose variations in AVR patients, the latter affected also by VKORC1 c.-1693G>A polymorphism.

Occupational, life stress and family functioning: does it affect semen quality?

BACKGROUND AND AIMS

Although psychological stress has been implicated as a cause of idiopathic infertility in both men and women, it has received little scientific attention among males as compared to females. The aim of the study was to examine the association between occupational, life stress, family functioning and semen quality.

METHODS AND RESULTS

The study population consisted of 327 men who were attending an infertility clinic for diagnostic purposes. Psychological stress was assessed based on two questionnaires: The Subjective Work Characteristics Questionnaire and the Perceived Stress Scale. The level of satisfaction with family functioning and support was evaluated by means of the APGAR Family Scale. The findings suggest that, on the one hand, exposure to occupational stressors can be negatively associated with semen quality (there was a positive association between stress and the percentage of sperm with DNA damage (p = 0.03) and atypical sperm (p = 0.05)); on the other hand, there was no correlation between the level of life stress and semen quality indicators. Negative associations were found between satisfaction with family functioning and the percentage of motile sperm cells (p = 0.02), VAP (p = 0.05), VSL (p = 0.05) and VCL (p = 0.04).

CONCLUSION

The study indicates that occupational stress can affect male semen quality; however, due to limited data on this issue, the obtained results should be confirmed in longitudinal studies.

Assessment of plasma membrane and chromatin structure of sperm from transgenic and non-transgenic boars

The aim of this study was to determine the apoptotic changes and chromatin damage in non-transgenic and transgenic boars carrying the human alpha1,2-fucosyltransferase gene. Five ejaculates were collected from six transgenic (TG) and six non-transgenic (NTG) boars. Five ejaculates were collected from six transgenic (TG) and six non-transgenic (NTG) boars both crossbreds of Polish Landrace and Large White. Two fluorescence methods were employed to measure apoptosis: an assay to assess the early changes in sperm membrane integrity using fluorophore YO-PRO-1 and an assay for phosphatidylserine (PS) translocation across the plasma membrane using fluorescein-labeled Annexin-V. The chromatin damage was assessed based on the sperm chromatin structure assay method. No significant differences in the proportion of all detected subpopulations of spermatozoa were found between TG and NTG boars. Similarly, the analysis of the chromatin structure revealed no statistical differences in the sperm chromatin damage between TG and NTG boars. In conclusion, the presence of the human alpha1,2-fucosyltransferase gene in the genome of TG boars did not cause any spermatogenesis process disturbances leading to the increased production of apoptotic spermatozoa. Moreover, the low level of sperm with damaged chromatin in TG boars confirms the high stability of the spermatogenesis process in the TG boars analyzed.

50 FLOW CYTOMETRY-MEDIATED DETECTION OF LATE-APOPTOTIC HYPODIPLOID CELL FRACTIONS IN LIPOFECTED PORCINE ADULT DERMAL FIBROBLAST CELL LINES SELECTED FOR SOMATIC CELL NUCLEAR TRANSFER

Analysis of nuclear DNA (nDNA) content of in vitro cultured somatic cells undergoing apoptosis became one of the most common methods for single-parameter flow cytometric measurement of this process. Apoptosis assessment is performed by quantification of hypodiploid cells. The cell fractions with hypodiploid (<2C) nDNA molecule number, which involve the so-called sub-G1 peak in DNA histograms are identified as late-apoptotic subpopulations. Advantage of this method is the possibility of simultaneous cell cycle measurement. The present study was conducted to investigate the preimplantation developmental outcome of porcine transgenic NT embryos reconstituted with non-apoptotic gilt ear skin-derived fibroblast cells that had been lipofected with pWAPhGH-GFPBsd gene construct. The nuclear donor cells were derived from such cell line populations whose representative random samples had been analyzed on both cell cycle and apoptosis through the non-vital nDNA fluorescent dyeing and subsequent flow cytometry (FACS). Frozen/thawed fibroblast cells, which had been cultured up to a total confluency after 2–3 passages, were used for the diagnostics. The fixed dermal fibroblasts were exposed to nDNA extraction buffer for 5 min and incubated in DNA staining solution (propidium iodide and RNAse) for 30 min. After fluorescent labeling, the cells were analyzed in the flow cytometer by reading nDNA fluorescence in the red band. Somatic cell cloned embryos, which had been created by simultaneous fusion and electrical activation, followed by delayed chemical activation of reconstructed oocytes, were cultured in NCSU-23/FBS medium for 6 to 7 days up to morula/blastocyst stages (Skrzyszowska et al. 2008 Theriogenology 70, 248–259). The FACS analysis revealed that out of all the fibroblast cells diagnosed, 94.9% were cycling and 5.1% were late-apoptotic. In turn, from among the non-apoptotic cells, an average of 92.7% were at G1/G0 stages of cell cycle, 3.1% were at S stage and 4.2% were at G2/M stages. A total of 294/348 (84.5%) enucleated oocytes were successfully fused with non-apoptotic nuclear donor cells. Out of 294 cultured NT embryos, 199 (67.7%) were cleaved. The rates of cloned embryos that reached the morula and blastocyst stages yielded 165/294 (56.1%) and 57/294 (19.4%), respectively. In conclusion, the FACS analysis for mitotic cycle of 100%-confluent lipofected adult dermal fibroblasts confirmed that the cell cycle synchronization at G1/G0 phases was highly efficient, while the frequency of late-apoptotic cells was low. It was also found that the relatively high percentages of pWAPhGH-GFPBsd transgenic blastocysts developed in vitro from NT embryos reconstructed with fibroblast cells undergoing lipofection. Furthermore, porcine cloned blastocysts exhibited approximately 100% index of reporter eGFP transgene expression, which was visually confirmed by their live-fluorescent evaluation. This work was supported by the Scientific Net of Animal Reproduction Biotechnology.

95 EFFICACY OF FIVE DIFFERENT SEMEN EXTENDERS FOR THE CRYOPRESERVATION OF BULL SEMEN

Replacement of animal-origin components in extenders used for bull semen freezing is of high importance for individuals involved in cattle breeding. The experiment was designed to compare efficacy of 5 different semen extenders in cryopreservation of bull semen: sodium citrate-based extender containing egg yolk (CT), commercially available Bioxcell� (IMV Technologies, L'Aigle, France), and 3 custom-made homogenized plant lipidsbased, egg yolk-free extenders (Y-1, Y-2, and Lipo) . The objective was to determine whether homogenization procedures of lipids improve the quality of the extender. Lipid homogenates of custom-made extenders were prepared in Tris buffer using a high pressure homogenizer (Nira Saovi, Parma, Italy). Ten (Y-1) or 5 (Y-2) homogenization cycles were applied and then 8% glycerol was added. Lipid liposomes were produced by simultanous high pressure homogenization of lipids and glycerol supplementation (Lipo). Semen was collected from young bulls of 3 different breeds (Simmental, Polish Red, and Holstein; 1 ejaculate/bull). Each ejaculate with at least 70% motility was split into 5 parts and processed further by a standard freezing protocol: semen was diluted at 35�C with each of the 5 extenders to a concentration of 100 � 106 spermatozoa per mL, cooled to 4�C over 5 h, aspirated into 0.25-mL plastic straws, frozen in liquid nitrogen vapor to –140�C, and then plunged into LN2. Straws were thawed in a water bath at 37�C for 20 s. Sperm motility was estimated microscopically immediately after thawing and after 5 h of storage at 22�C. Immediately after thawing, flow cytometry and SYBR-14/PI staining were used for examination of sperm membrane integrity (live/dead assay). A total of 20 000 spermatozoa of each sample were counted. Student's t-test was used to estimate statistical differences between experimental groups. The mean sperm motility after thawing ranged from 45.6% (SD = 13.7) for CT (egg yolk extender) to 57.8% (SD = 7.1) for Lipo. A significant difference (P < 0.05) was observed betweenY-1 (50.0%, SD = 9.7) and Lipo and Bioxcell (56.1%, SD = 8.6). After 5 h of storage at 22�C, the mean motility for all tested bulls ranged from 25.0% (SD = 7.1) for CT to 42.2% (SD = 7.5) for Lipo. Significant differences were observed between Lipo (P < 0.01), Y-2 (P < 0.05) and CT, and between Y-1 and Lipo (P < 0.01). Mean percentage of 'live' spermatozoa with intact membrane after freezing/thawing was 51.85% (SD = 11.49) for Y-1, 45.72% (SD = 9.36) for Y-2, 47.57% (SD = 7.93) for Lipo, 45.47% (SD = 8.35) for Bioxcell, and 49.06 (SD = 11.59) for CT. No significant differences were observed except forY-1 and Bioxcell extenders (P < 0.05). It can be concluded that both methods of lipid/glycerol homogenization can be successfully applied in the preparation of bull semen extender. In addition, extensive lipid homogenization (10 cycles) produced more transparent extender that in turn improved visualization of sperm. Custom-made plant origin lipids homogenization may provide a valuable alternative for the preparation of extenders that more closely match the membrane composition of bull sperm cells and thus contribute to development of an efficient extender free of animal-origin components for bull semen freezing.

258 THE EFFECT OF A PLANT PROTEIN COMPONENT OF MEDIA USED FOR BULL SPERM SEXING ON SPERM MEMBRANE STATUS

The aim of the work was to examine the effect of modified TALP medium (TALP/Pp, Animal Pharma B.V., Hengelo, The Netherlands)—used in the sperm sexing procedure—on bull sperm membrane status. The TALP was modified by replacement of bovine serum albumin (BSA) with a mixture of several plant proteins and soya lecithin (Pp). The Pp component was prepared using a high pressure homogenization process. The TALP/Pp had the same pH and osmotic pressure as the original TALP medium (TALP/BSA). The work was divided into 2 parts: (1) Nine ejaculates collected from 2 bulls (Holstein and Polish Red) were used. Immediately after collection, each ejaculate was split into 2 parts and diluted (1:2) with TALP/BSA or TALP/Pp. The sperm membrane status was examined after 3 days of storage at 15�C. (2) Fifteen ejaculates collected from 5 bulls (Holstein, Polish Red, and Simmental) were used. Each ejaculate was split into 2 parts: the first part was diluted with TALP/BSA, stained, incubated, and sexed according to the XY Inc. bull semen sexing procedure; the second part was diluted, stained, incubated, and collected after sexing into TALP/Pp with no egg yolk addition. In both groups no red food due was used to identify and exclude the dead spermatozoa from the sorted fractions. The sperm sexing procedure was performed with an SX MoFlo high-speed sorter at a speed of 3000–4000 cells/s. After collecting about 10 million spermatozoa, both fractions, X andY, were mixed, centrifuged at 700g for 15 min to concentrate the spermatozoa (20 million mL–1), and the sperm membranes examined. For sperm membrane examination, 'live/dead' samples were stained with SYBR-14/propidium iodide fluorochromes and analyzed by flow cytometry. The data from 20 000 spermatozoa were collected for each sample. The percentage of membrane-intact ('live') spermatozoa was taken for statistical analysis. The mean percentage of live spermatozoa stored for 3 days in TALP/BSA v. TALP/Pp was 25.7% (SD = 7.48) v. 28.58% (SD = 7.04), respectively (P < 0.01). The mean percentage of live spermatozoa in samples of sexed semen was 33.57% (SD = 18.97) for TALP/BSA and 38.51% (SD = 20.22) for TALP/Pp (P < 0.01). It can be concluded that Pp should be considered as a replacement for BSA in the TALP medium used for bull sperm sexing because (1) it results in significantly higher numbers of live spermatozoa after storage and/or sexing; (2) it eliminates a possible source of transmissible diseases (such as bovine spongiform encephalopathy); and (3) it decreases the total cost of the basic media used for the bull sperm sexing procedure.

83 IN VITRO DEVELOPMENTAL ABILITIES OF PORCINE CLONED EMBRYOS RECONSTITUTED WITH CELL NUCLEI OF GENETICALLY TRANSFORMED FETAL FIBROBLASTS CYTOMETRICALLY DIAGNOSED ON CELL CYCLE AND APOPTOSIS

The important factor that determines the development of mammalian cloned embryos is structuro-functional quality of nuclear donor cells. Analysis of nuclear DNA (nDNA) content of somatic cells undergoing apoptosis has become one of the most common methods for single-parameter flow cytometric measurement of this process. Apoptosis assessment is performed by quantification of hypodiploid cells. The aim of our study was to examine the in vitro developmental potential of porcine nuclear transfer (NT) embryos reconstituted with non-apoptotic fetal fibroblast cells expressing the eGFP transgene. The nuclear donor cells were derived from cell line populations whose representative random samples had been analyzed on both cell cycle and apoptosis through non-vital nDNA fluorescent dyeing and flow cytometry (FACS). Frozen-thawed fibroblast cells, which had been cultured up to a total confluency after 2–4 passages, were used for the diagnostics. The cells were fixed in ice-cold 70% ethanol. Then, the fetal fibroblasts were exposed to nDNA extraction buffer for 5 min at room temperature, and incubated in DNA staining solution (propidium iodide and RNAse) for 30 min. After fluorescent labeling, the cells were analyzed in the flow cytometer by reading nDNA fluorescence in the red band. In vitro-matured oocytes were the source of recipient cells. Fibroblast cell–ooplast couplets were simultaneously fused and activated. Reconstructed embryos were cultured in NCSU-23/BSA/FBS medium for 6–7 days. The rates of cleavage and development to morula/blastocyst stages were examined on Days 2 and 6/7, respectively. FACS analysis revealed that, out of all of the diagnosed fetal fibroblast cells, 54.7% were cycling, and up to 45.3% were late-apoptotic. In turn, from among the normal (i.e. non-apoptotic) cells, 82.2% were at G0/G1 stages of cell cycle, 17.0% at the S stage, and 0.8% at G2/M stages. A total of 150 enucleated oocytes were successfully fused with non-apoptotic transgenic nuclear donor cells. Out of 150 cultured NT embryos, 123 (82.0%) were cleaved. The frequencies of cloned embryos that reached the morula and blastocyst stages yielded 53/150 (35.3%) and 37/150 (24.7%), respectively. In conclusion, the FACS analysis for mitotic cycle of 100%-confluent transgenic fetal fibroblasts confirmed the high efficiency of the cell cycle synchronization at G0/G1 phases. However, a contact inhibition method induced the high frequency of late-apoptotic cells. Moreover, the relatively high percentage of NT blastocysts was developed from oocytes reconstructed with eGFP transgenic fetal fibroblast cells. This research was supported by the State Committee for Scientific Research as a Solicited Project number PBZ-MIN-005/P04/2002/6 from year 2003 to year 2006.

361 INFLUENCE OF SEXING PROCEDURE ON BULL SPERM CHROMATIN STRUCTURE

Flow cytometry is the only reliable and relatively fast method allowing separation of live X and Y spermatozoa for sex regulation. Many thousands of animals of different mammalian species have been born after insemination with sexed semen during the past 20 years. Nevertheless, the question is still open: does the bull sperm sexing technology affect chromatin structure? A case of serious chromatin damage after sexing stallion semen was reported previously (Bochenek et al. 2006 Havemeyer Foundation Monograph Series No. 18, 13 –14). The aim of this work was to examine the effect of the sexing procedure and different UV laser powers on bull sperm chromatin structure. The ejaculates of 28 bulls (one ejaculate/bull) were used in the study. Each ejaculate was divided into 5 groups: (1) control, unprocessed; (2) sorted strictly according to XY Inc. protocol (Schenk et al. 1999 Theriogenology 52, 1375 –1391); (3) as group 2, but without the Red Food dye staining used for dead spermatozoa discrimination; (4) as group 2, but with double UV laser power (300 mW); and (5) as group 3, but with double UV laser power (300 mW). Sperm sorting was performed with a MoFLoSX flow cytometer at speeds of 3000 –5000 cells/s. Sorted fractions of X and Y spermatozoa were mixed again and stored for 24 h at 15 °C. A sperm chromatin structure assay (SCSA) was performed twice on each sorted sample, immediately after sorting and after 24 h. The chromatin of control samples was examined according to the same time schedule. The percentage of spermatozoa with damaged chromatin was calculated (COMP α-t) as well as standard deviation of the α-t parameter (SD α-t). The latter parameter, although less intuitive, is considered as even more precise than COMP α-t in chromatin investigations. The mean percentage of spermatozoa with abnormal chromatin was 1.12% (SD = 0.47) for control samples. The highest level of chromatin abnormality was noted for the 300 mW group with no dead cell discrimination (Red Food staining): 1.29% (SD = 1.05). After 24 h of storage, the mean level of chromatin abnormality increased to 1.97% (SD = 0.96) in control samples whereas that in all sorted samples was lower: from 1.06% (SD = 0.4) to 1.16% (SD = 0.62) in the 150 mW/non-Red Food-stained and the 300 mW/Red Food-stained groups, respectively. This difference appeared to be statistically significant (t; P ≤ 0.05). Interestingly, the percentage of abnormal spermatozoa decreased slightly after 24 h of storage in the 300 mW/Red Food-stained and the 300 mW/non-Red Food-stained groups ( –0.13% and –0.08%, respectively). Calculation of the SD α-t parameter showed statistically significant differences in chromatin abnormality between the control group vs. the 300 mW/non-Red Food-stained group immediately after sorting and the control group vs. the 150 mW/Red Food-stained group after 24 h of storage. In conclusion, although the statistically significant increase of chromatin damage was found after sexing in some investigated groups, it seems that the level of this abnormality is far too low to affect sexed semen fertility.

In vitro production of bovine embryos using flow-cytometrically sexed sperm

Abstract. The investigation aimed to compare the effect of fresh and frozen-thawed X and Y fractions of flow-cytometrically sorted bovine spermatozoa on in vitro fertilization of bovine in vitro matured oocytes and subsequent blastocyst development. Sperm cells sorted in MoFloSX cytometer were used either for IVF or frozen and stored in liquid nitrogen. Immature oocytes recovered from ovaries of slaughtered animals and matured in vitro in TCM-199 containing 20% estrus cow serum and additional granulosa cells were fertilized in vitro with fresh or frozen-thawed fractions of sorted sperm. Simultaneously, control, fresh or frozen/thawed sperm was used for IVF. A total number of 2712 IVM oocytes were fertilized with sorted and control sperm of 6 bulls. Embryo cleavage rates were significantly affected by bull (P<0.0001), sperm sexing (P<0.0001) and sperm freezing (P<0.01). Blastocysts development was affected by sperm freezing (P<0.04) and sperm sexing (P<0.01). The significant differences were shown between unsorted and sorted sperm, however no differences in embryo cleavage rates and blastocysts rates were observed between X- and Y-sperm fractions, both fresh and frozen/ thawed. There were significant differences in cleavage rates among fresh, control sperm (52.7%), X fraction (26.8%) and Y fraction (24.7%). Similar differences in cleavage rates were shown for frozen/thawed control sperm (52.8%), X fraction (33.9%) and Y fraction (26.2%). The female blastocysts were frozen for further transfer, while the hatched male blastocysts were analysed by PCR revealing 76.2% accuracy. The results suggest that there were significant differences in cleavage rates and blastocyst rates due to sperm sorting in comparison to unsorted sperm and no differences between effectiveness of X and Y fractions of spermatozoa.

Effect of quality of sperm chromatin structure on in -vitro production of cattle embryos

Abstract. Bull effect on results of in vitro embryo production has been well documented. The aim of the present study was to find the relationship between quality of bull sperm chromatin and its effect on in vitro embryo production. Bovine in vitro matured oocytes were fertilized in vitro using capacitated spermatozoa (freshly ejaculated or frozen-thawed) of 12 bulls. Semen was simultaneously processed according to the sperm chromatin structure assay (SCSA) method and was analysed by flow cytometry. At least 3 replications of IVP with the same semen sample were done. The percentage of spermatozoa with abnormal chromatin ranged from 0.4% to 23.8%. All bulls used for the experiment were divided into three groups showing minimal (0.82% ± 6.82%), low (1.70% ± 15.82%) and high (18.16% ± 53.59%) percentages of spermatozoa with abnormal chromatin structure. Both cleavage rates and embryo development to the blastocyst stage were correlated significantly with sperm chromatin abnormalities and resulted in 23.1, 17.7 and 12.2% of blastocysts respectively for sperm with minimal, low and high percentages of chromatin abnormalities. The SCSA method may be used as a practical indicator of suitability of bull ejaculate for IVP purposes.

307 IN VITRO PRODUCTION OF BOVINE EMBRYOS USING FLOW-CYTOMETRICALLY SORTED SPERMATOZOA

There are two practical ways to predetermine the sex of mammalian offspring: sexing pre-implantation embryos and sexing spermatozoa. The only successful and non-invasive method of sexing spermatozoa is quantifying sperm DNA with fluorescing DNA-binding dye, followed by flow cytometry and cell sorting. Our investigations aimed to develop a technology for in vitro embryo production in cattle using fresh and/or frozen-thawed spermatozoa sexed by flow cytometry. Sperm was sorted in a MoFloSX® cytometer using the method of XY, Inc. (Fort Collins, CO, USA; Research Collaboration Agreement). After sorting, the sperm was either used for IVF or frozen and stored in liquid nitrogen. Immature oocytes, recovered from slaughterhouse ovaries, after 22 to 23 h of IVM in TCM-199 containing 20% estrous cow serum and additional granulosa cells (Katska et al. 1998, J. Anim. Feed Sci. 7, 353–362), were fertilized in vitro with fresh or frozen-thawed X and Y fractions of spermatozoa. Simultaneously control, unsorted, fresh and frozen-thawed sperm was used for IVF. The standard protocol of sperm capacitation (Katska and Rynska 1998 Theriogenology 50, 213–222) was applied for both control sperm and fresh fractions of sexed sperm. Briefly, sperm was separated by Percoll gradient centrifugation, washed, and introduced into drops of Tyrode's albumin-lactate-pyruvate (TALP)-IVF (containing 10 μg heparin mL−1 and mixture of penicillamine, hypotaurine, and epinephrine) at a concentration 1 to 2 × 106 spermatozoa mL−1 of medium. Frozen fractions of sorted spermatozoa were centrifuged after thawing (500 g for 10 min) and immediately introduced into the IVF drops at 2 to 3 × 106 spermatozoa mL−1 of medium. Embryos resulting after IVF were co-cultured with Vero cells in B2 medium supplemented with 2.5% fetal calf serum for 8 to 10 days, (i.e., to the hatched blastocyst stage). A total of 2074 IVM oocytes were fertilized with both fresh and frozen-thawed sexed and control sperm of 5 bulls. There were significant differences (P < 0.01) in cleavage rates among fresh control sperm (120/256; 46.9%), the X fraction (66/254; 26.0%), and the Y fraction (58/230; 25.2%). Similar differences in cleavage rates (P < 0.01) were shown for frozen-thawed control sperm (156/335; 46.6%), the X fraction (137/498; 27.5%), and the Y fraction (118/501; 23.6%). No differences were observed in efficiency of embryo development to the blastocyst stage between the fresh control (25.8%) and the Y fraction (25.9%), or among the frozen control (16.7%) and the X fraction (13.1%) or the Y fraction (16.9%). However, significant differences (P < 0.05) were shown between blastocyst rates with the fresh X fraction (10.6%) and the control. Our results suggest that there were differences due to sperm sorting but no differences in efficiency of both fresh and frozen-thawed X and Y fractions of spermatozoa. Research was supported by the State Committee for Scientific Research as a project 3PO6D 044 23.

311 CATTLE SEX REGULATION BY SEPARATION OF X AND Y SPERMATOZOA PRELIMINARY RESULTS OF FIELD EXPERIMENT IN POLAND

The only reliable and relatively fast method of sex regulation in cattle is X and Y sperm high-speed sorting by flow cytometry. In October 2003 a field experiment started in Poland. The aim of the experiment was to examine the efficiency of sperm sexing and the fertility rate in field conditions. The semen of three Holstein bulls was used for the experiment. The semen was sexed and frozen according to modified XY, Inc. (Fort Collins, CO, USA) method. Only the X-fraction of spermatozoa was sorted and frozen. Sexing was performed at a speed of 15–20 × 106 spermatozoa/h and frozen in doses of 2.5 × 106 spermatozoa/straw. Progressive motility of spermatozoa was 90–95% immediately after sorting and 50–70% after freezeing/thawing for all three bulls. The X-fraction sorting purity was checked by re-analysis and it ranged from 90% to 96%. In total, 316 inseminations at 10 farms were performed up to June 2004. Fertility data of 178 inseminations were collected by ultrasonographic (USG) examination during the same time. Average fertility rate was 37.08%. However, significant variations of fertility rates were observed between farms: it ranged from 22.22% to 84.21%. Four calves, all females, were born after insemination with the X-fraction until June 2004. The experiment will continue.

262 SPERM CHROMATIN STRUCTURE, OXIDATIVE STRESS AND BASIC SEMEN PARAMETERS OF MEN FROM SUBFERTILE COUPLES

It is known that the mammalian sperm chromatin structure plays an important role in male fertility. In opposition to many other areas of biological research, the human sperm chromatin can be considered as a model for animal fertility investigations. This is due to the great number of males with high levels of chromatin abnormalities and the ease of tracking their fertility potential. The aim of the study was to find a relationship between sperm chromatin structure, level of reactive oxygen species (ROS) and the basic semen parameters: sperm concentration and motility. The semen from a total of 391 men from subfertile couples 22–51 years old was used. The sperm chromatin abnormalities were examined flow cytometrically according to the SCSA method (sperm chromatin structure assay; Evenson D.P. Methods In Cell Biology, vol. 33, 1990) and ROS level was examined by luminometry (Kolletis et al. 1999 Fertil. Steril.). Sperm concentration and motility were checked microscopically. Sperm concentration of the examined ejaculates ranged from 0.05 × 106/mL to 627.5 × 106/mL and progressive motility ranged from 0% to 70%. More than 30% of spermatozoa with abnormal chromatin (level considered as the infertility threshold) was found in 70 (17.9%) patients; 15–30% of spermatozoa with abnormal chromatin (level of decreased fertility potential) was found in 154 (39.4%) patients; and in 167 (42.7%) patients the number of abnormal spermatozoa did not exceed 15% (level of normal fertility potential; Evenson et al. 1999 Hum. Reprod.; Zini et al. 2001 Fertil. Steril.). High significant correlations were found between chromatin abnormality and: patients' age (0.1008, P = 0.017), sperm concentration (−0.2735, P < 0.001), progressive motility (−0.4365, P < 0.001), and ROS level (0.2709, P < 0.001). However in patients with normal sperm concentration (>20 × 106/mL, according to the World Health Organization), as many as 11.5% had a high level of chromatin abnormality (>30% of abnormal chromatin) and 29.7% of moderate chromatin abnormality (15–30% abnormal chromatin). Similarly, in patients with normal progressive sperm motility (>50%, according to the World Health Organization) 1.7% had a high level of chromatin abnormality (>30% of abnormal chromatin), and 33.9% had a moderate level of chromatin abnormality (15–30% abnormal chromatin). Contrary to the findings of many earlier investigations, a strong relationship between sperm chromatin damages and basic semen parameters was observed in this work. The sperm chromatin structure assay should be included in standard semen examination to avoid expensive and time consuming in vitro procedures for spermatozoa with damaged DNA.

Flow cytometric cell cycle analysis of somatic cells primary cultures established for bovine cloning

An important factor governing developmental rates of somatic cloned embryos is the phase of the cell cycle of donor nuclei. The aim of this experiment was to investigate the distribution of cell cycle phases in bovine cumulus and fibroblast cells cultured using routine treatment, and under cell cycle-arresting treatments. The highest percentages of cumulus cells in the G0 + G1 stage were observed in uncultured, frozen/thawed cells originating from immature oocytes (79.8 +/- 2.2%), fresh and frozen/thawed cells from in vitro matured oocytes (84.1 +/- 6.2 and 77.8 +/- 5.7%, respectively), and in cycling cells (72.7 +/- 16.3 and 78.4 +/- 11.2%, respectively for cumulus cells from immature and in vitro matured oocytes). Serum starvation of cumulus cultures markedly decreased percentages of cells in G0 + G1, and prolonged starvation significantly increased (P < 0.05) percentages of cells in G2 + M phase. Culture of cumulus cells to confluency did not increase percentages of cells in G0 + G1. Contrary to findings in cumulus cells, significantly higher percentages of cells in G0 + G1 were apparent when fibroblast cells were cultured to confluency or serum starved, and significantly increased (P < 0.01) as the starvation period was prolonged. It is concluded that for particular cell types specific strategies should be used to attain improvements in the efficiency of cloning procedures.

Flow cytometric detection of apoptotic bone marrow cells with fractional DNA content after application of WR-2721, cyclophosphamide, cisplatin, and exposure of mice to gamma rays

Little is known about the mechanisms of apoptosis triggered in normal cells of the haemopoietic system by the aminothiol WR-2721 (Amifostine), chemotherapeutic drugs, and ionizing radiation; thus, the present study was undertaken to evaluate the effects of WR-2721, cyclophosphamide (CP), cisplatin (CDDP), and 60Co gamma rays on induction of apoptotic DNA degradation in bone marrow cells. Adult male Swiss mice were treated with WR-2721 (400 mg/kg b.wt.), CP (200 mg/kg b.wt.), and CDDP (10 mg/kg b.wt.), and exposed to 6 Gy 60Co gamma rays. Alterations in the number of apoptotic cells with fractional DNA content and also the cell cycle position of the non-apoptotic cells were determined in the bone marrow at 7 and 24 hours after treatment of mice with these agents, using flow cytometric assay of the controlled extraction of low-MW DNA from apoptotic cells. The chemotherapeutic drugs CP and CDDP and 60Co gamma rays triggered apoptosis and affected the cell cycle position of the non-apoptotic cells in the mouse bone marrow. The pretreatment of mice with WR-2721 resulted in the modulatory action of the aminothiol on induction of apoptotic cell death and changes in the cell cycle distribution of the non-apoptotic cells caused by the DNA-damaging agents. The patterns of changes in the frequency of apoptotic cells and the cell cycle position of the non-apoptotic cells, observed in the bone marrow, were dependent on the agent(s) applied and the time interval after application of the drug(s) and exposure of mice to gamma rays. Understanding of the mechanisms responsible for triggering of apoptotic cell death and disturbing of the cell cycle by the DNA-damaging agents, and modulation of the apoptotic and cell cycle pathways by the aminothiol WR-2721, can lead to more effective therapy and chemo- and radio-protection of normal cells.

Effect of rabbit age on sperm chromatin structure

The aim of this study was to determine the relationship between the age of male rabbits and the sperm chromatin structure. The studies involved the semen of New Zealand White rabbits between 5 and 28 months of age. A flow cytometry and sperm chromatin structure assay (SCSA) method was used to determine chromatin structure. The results of cytometric chromatin structure assay suggested a relatively high stability of sperm chromatin in the rabbit. Between 6 and 16 months of age, the mean percentage of sperm with damaged chromatin was the lowest and ranged from 1.7 to 2.4%. Decreased sperm chromatin stability was found in ejaculates taken from male rabbits less than 5 months and more than 20 months of age.

Sperm chromatin structure assay of bulls qualified for artificial insemination

The goal of our study was to find the relationship between fertility of bulls qualified for AI and the percentage of spermatozoa with abnormal chromatin structure as an independent parameter. We used the frozen semen of 8 mature bulls from one AI center. Each bull was represented by 3 ejaculates collected with at least 2-week intervals. Bull fertility was calculated on the basis of non-return ratio and was expressed as a scale where 100 points represented the average fertility of all the AI center's bulls. Bulls with lower or higher fertility received a lower or higher score respectively. Fertility scores of bulls used in the study ranged from 83 to 104 . Semen was processed according to the SCSA (sperm chromatin structure assay) method and was analyzed by flow cytometry. "Artificial" alpha(t) (alpha(t)=red/green+red fluorescence) and red fluorescence histograms were used for calculation of COMPalpha(t), SDalpha(t), %Red, %PeakR and MeanR parameters. The percentage of spermatozoa with abnormal chromatin ranged from 1.2% to 23.8%. A large variation among ejaculates was found for bulls with lower fertility. Fertility correlated significantly with COMPalpha(t) (-0.50, P < 0.05), SDalpha(t) (-0.55, P < 0.01), %Red (-0.53, P < 0.01), %PeakR (-0.58, P < 0.01) and MeanR (-0.45, P < 0.05). The SCSA method has a practical application in analyzing spermatogenesis disorders in bulls. If regularly applied, it allows us to identify and eliminate ejaculates with a high level of sperm chromatin abnormalities.

Sperm chromatin integrity of bucks transgenic for the WAP bGH gene

The aim of the study was to compare sperm chromatin structure of transgenic and non-transgenic rabbits. In addition, the effect of chromatin structure on semen fertility was determined. Twenty male rabbits transgenic (TG) for WAP bGH gene (Edison Biotechnology Institute Ohio University, USA) and nine non-transgenic (NTG) males were used. Both TG and NTG rabbits were 13-18 months old. Semen was collected at 1-week intervals and 3-7 ejaculates from each rabbit were examined in total. Sperm chromatin abnormalities were measured flow cytometrically according to the Sperm Chromatin Structure Assay method: after chromatin denaturation by low pH, sperm cells were stained with metachromatic fluorochrome acridine orange. Spermatozoa with abnormal chromatin structure and, subsequently, higher degree of denaturation, showed a shift in red fluorescence. Two different methods of semen fertility estimation were used: (1) for TG rabbits, AI of superovulated does and calculation of percentages of fertilised eggs and embryos developing in vitro to the blastocyst stage; (2) for NTG rabbits, AI of non-stimulated does and calculation of percentages of pregnant does and mean litter sizes. The mean value of COMPalpha(t) was 3.71 for TG rabbits and 2.89 for NTG rabbits (no significant difference, t-test). The mean values of S.D.alpha(t) for the TG and NTG rabbits were 10.94 and 10.40 (no significant difference, t-test), respectively. There were no significant correlations between sperm chromatin structure of TG males and the percentages of fertilised eggs or embryos developing to the blastocyst stage. A statistically significant correlation (-0.68, P<0.05) was found between S.D.alpha(t) of NTG males and percentages of pregnant does. The results showed chromatin stability was not different for sperm obtained from TG versus NTG bucks. The presence of WAP bGH gene construct in the genome of transgenic rabbits did not cause any spermatogenesis process disturbances leading to the production of spermatozoa with damaged chromatin structure. This suggests that the mere presence of the introduced gene construct does not lead to any abnormalities in DNA and chromatin proteins interaction. The possible chromatin damages in transgenic animals should be attributed to the activity of the introduced gene. The relationships between chromatin structure and fertility are only significant for sperm from NTG bucks.