Formation of Re-Aggregated Neonatal Porcine Islet Clusters Improves In Vitro Function and Transplantation Outcome

Neonatal porcine islet-like cell clusters (NPICCs) are a promising source for islet cell transplantation. Excellent islet quality is important to achieve a cure for type 1 diabetes. We investigated formation of cell clusters from dispersed NPICCs on microwell cell culture plates, evaluated the composition of re-aggregated porcine islets (REPIs) and compared in vivo function by transplantation into diabetic NOD-SCID IL2rγ-/- (NSG) mice with native NPICCs. Dissociation of NPICCs into single cells and re-aggregation resulted in the formation of uniform REPI clusters. A higher prevalence of normoglycemia was observed in diabetic NSG mice after transplantation with a limited number (n = 1500) of REPIs (85.7%) versus NPICCs (n = 1500) (33.3%) (p < 0.05). Transplanted REPIs and NPICCs displayed a similar architecture of endocrine and endothelial cells. Intraperitoneal glucose tolerance tests revealed an improved beta cell function after transplantation of 1500 REPIs (AUC glucose 0-120 min 6260 ± 305.3) as compared to transplantation of 3000 native NPICCs (AUC glucose 0-120 min 8073 ± 536.2) (p < 0.01). Re-aggregation of single cells from dissociated NPICCs generates cell clusters with excellent functionality and improved in vivo function as compared to native NPICCs.

Child Sexual Abuse-Challenging Conditions for Adult Oral Health: A Qualitative Study

The aim was to analyze perceptions of oral health in adults who have been exposed to child sexual abuse. Eleven participants (10 women), 19 to 56 y of age, who had experienced sexual abuse as children were purposively selected and interviewed in-depth. The participants were encouraged to describe how they perceived the effect of the sexual abuse on their oral health as adults. The interviews were recorded digitally and transcribed verbatim. The collected material was analyzed according to qualitative content analysis. The theme "challenging conditions for maintaining oral health" was identified, comprising 2 categories: first, "the emotional significance," with the subcategories 1) emotional barriers and 2) powerful relief, and second, "the obstacles to oral health," with the subcategories 1) daily self-care with complications and 2) dental appointments with difficulties. The findings indicate that the experience of sexual abuse during childhood can have a negative impact on oral care in adulthood. The informants stated that oral health was of utmost importance but also associated with strong emotions. There were obstacles to maintenance of oral health that were difficult to surmount.Knowledge Transfer Statement:The study provides access to the attitudes of survivors of child sexual abuse regarding oral health and the needs and obstacles that they experience. This is important knowledge for dental professionals to optimize dental care.

Analysis of the sex-specific variability of blood parameters in C3H inbred mice by using data from a long-term, high-throughput project

Mice are important models for biomedical research by providing the possibility of standardizing genetic background and environmental conditions, which both affect phenotypic variability. Use of both sexes in experiments is strongly recommended because of possible differences in the outcome. However, sex-specific phenotypic variability is discussed with regard to putative consequences on the group size which is necessary for achieving valid and reproducible results. Here, we retrospectively analyzed the sex-specific variability of 25 blood parameters of C3H inbred mice in two different mouse facilities withinthe long-term, high-throughput Munich ENU mouse mutagenesis project. Using the 95 % data range, data of4,780-20,706 mice per parameter were analyzed and resulted in ratios of the coefficient of variation (= female CV / (female CV + male CV)) from 0.44 to 0.58 for the 25 parameters, with an overall mean of 0.51 in both facilities. Together with data analyses of three additional, smaller studies with 72-247 animals per parameter examined and various genetic backgrounds (inbred strains, F1 hybrids) included, hints for reproducible sex-specific variability were observed for particular parameters. Thus, the overall analysis comprising all 25 clinical chemical and hematological parameters of the standardized, long-term analysis of a high number of group housed, young adult, twelve-week-old C3H inbred mice showed no evidence for substantial sex-specific variability. The results may provide a basis for the examination of sex-specific variability in particular blood parameters.

High prevalence of comorbidities and use of concomitant medication in treated people living with HIV in Germany - results of the BESIDE study

Due to demographic changes in people living with HIV (PLHIV), physicians are challenged with age-related comorbidities and their management. In the absence of comprehensive data collection, the burden of comorbidities and co-medication in addition to antiretroviral therapy (ART) remains unclear for the German real-world setting. BESIDE was an observational, cross-sectional study evaluating the prevalence of comorbidities and use of co-medication in treated PLHIV. Regional distribution of study centers (n = 20), consecutive patient recruitment, and age-stratified sampling in alignment with national epidemiologic data aimed to ensure a representative sample (n = 453). The overall prevalence of comorbidities was 91.2%; 31.6% of patients had ≥4 comorbidities. The most common diagnoses were vitamin D deficiency (29.1%), depressive episode (27.8%), arterial hypertension (16.3%), and hypercholesterolemia (10.8%). 83.7% of patients were on co-medication; 21.2% taking ≥4 medications. The most common medications or supplements were vitamins (31.6%), anti-inflammatory agents (16.1%), renin-angiotensin system agents (12.1%), acid suppressants (11.7%), lipid modifying agents (10.8%); 1.3% of patients were on co-medication that should not be co-administered with ART, 41.5% on co-medication with potential for drug-drug interactions. The prevalence of comorbidities and use of co-medication among treated PLHIV in Germany is consistently high and increases across age groups, illustrating the complexity of HIV care involving appropriate ART selection.

Coronal restoration of the root filled tooth - a qualitative analysis of the dentists' decision-making process

Aim

To describe the decision‐making process of the general dental practitioner (GDP) underlying the choice of coronal restoration of a root filled tooth.

Methodology

GDPs were strategically selected with respect to gender, age, undergraduate dental school, service affiliation and duration of professional experience. Semistructured in‐depth interviews were conducted, focusing on the informant’s personal experience of the process which leads to a decision as to how to restore a root filled tooth. The informants were invited to describe in their own words the latest two cases involving decisions of direct or full crown restorations respectively. The interviews were digitally recorded and transcribed verbatim. Interviews from 14 informants, aged 27–64 (mean age 46 years), were included and analysed according to Qualitative Content Analysis.

Results

A theme (latent content) was identified: Clinical factors were considered important but were overruled by context and patient opinions, if in conflict. Three main categories, including seven subcategories (manifest content), were identified. The categories were clinical factors, contextual factors and patient's views. Clinical factors underlying the GDPs' decision included the current dental status and the estimated longevity of the intended restoration. In certain cases, contextual factors were also of importance, either supporting the GDPs' decision or modifying it. However, the patient's views played a decisive role in the final choice of coronal restoration, leading to either mutual acceptance or a compromise, taking into account the patient's economic status and opinions.

Conclusions

With respect to coronal restoration of a root filled tooth, the GDPs’ decision‐making process was based not only on clinical factors, but also on decisive contextual factors and consideration of the patients’ views.

High prevalence of recreational and illicit drug use in German people living with HIV with a potential for drug-drug interactions with antiretroviral therapy

Recreational drug use is higher in people living with HIV (PLHIV) than in the general population in Europe. This use increases the risk for drug-drug interactions (DDIs) and adverse events. We assessed the prevalence and clinical consequences of substance abuse among PLHIV. BESIDE was a cross-sectional, multi-center study in 2016/18, evaluating comorbidities, polypharmacy and recreational/illicit drug use in PLHIV on antiretroviral therapy (ART) in Germany. Legal and illicit drug use was recorded using two anonymous patient questionnaires one year apart (Q1 and Q2). The BESIDE study population consisted of 453 PLHIV (22% female, median age 46 years). Recreational drug use was reported by the majority (Q1: ever used 73%, within previous 6 months 56%): nitrite inhalants ("poppers"), cannabis and PDE-5 inhibitors were common across all age groups; ecstasy, (meth-)amphetamine and gamma-hydroxybutyrate/gamma-butyrolactone were predominantly reported by younger PLHIV. Based on Q2, two-thirds of PLHIV (67%) had been informed about potential risks of drug abuse by their doctors, whereas one-third (33%) had talked to their doctors on their own initiative with only 7% considering drug use in combination with ART a problem. Strikingly, 44% and 42% had undergone medical treatment or had been hospitalized due to drug use. These data emphasize the high clinical relevance of recreational drug use in PLHIV and the need for treating physicians to pro-actively communicate the potential risks.

What do the changing patterns of comorbidity burden in people living with HIV mean for long-term management? Perspectives from European HIV cohorts

Undoubtedly, comorbidities complicate long-term HIV management and have significant cost implications for healthcare systems. A better understanding of these comorbidities and underlying causes would allow for a more considered and proactive approach to the long-term management of HIV. This review examines cross-sectional analyses of six European cohort studies (Athens Multicenter AIDS Cohort Study, Aquitaine Cohort, EuroSIDA Cohort study, French claims EGB, German InGef Cohort and the Italian Cohort of Individuals, Naïve for Antiretrovirals), which included individuals with HIV followed over a certain period of time. Based on these cohorts, we examined how comorbidities have changed over time; how they compromise HIV management; and how much of a financial burden they impart. These data also provided a framework to explore the major issues of ageing and HIV and the practical implications of managing such issues in real-life practice.

Linkage between growth retardation and pituitary cell morphology in a dystrophin-deficient pig model of Duchenne muscular dystrophy

OBJECTIVE

Human patients with Duchenne muscular dystrophy (DMD) commonly exhibit a short stature, but the pathogenesis of this growth retardation is not completely understood. Due to the suspected involvement of the growth hormone/insulin-like growth factor 1 (GH/IGF1) system, controversial therapeutic approaches have been developed, including both GH- administration, as well as GH-inhibition. In the present study, we examined relevant histomorphological and ultrastructural features of adenohypophyseal GH-producing somatotroph cells in a porcine DMD model.

METHODS

The numbers and volumes of immunohistochemically labelled somatotroph cells were determined in consecutive semi-thin sections of plastic resin embedded adenohypophyseal tissue samples using unbiased state-of-the-art quantitative stereological analysis methods.

RESULTS

DMD pigs displayed a significant growth retardation, accounting for a 55% reduction of body weight, accompanied by a significant 50% reduction of the number of somatotroph cells, as compared to controls. However, the mean volumes of somatotroph cells and the volume of GH-granules per cell were not altered. Western blot analyses of the adenohypophyseal protein samples showed no differences in the relative adenohypophyseal GH-abundance between DMD pigs and controls.

CONCLUSION

The findings of this study do not provide evidence for involvement of somatotroph cells in the pathogenesis of growth retardation of DMD pigs. These results are in contrast with previous findings in other dystrophin-deficient animal models, such as the golden retriever model of Duchenne muscular dystrophy, where increased mean somatotroph cell volumes and elevated volumes of intracellular GH-granules were reported and associated with DMD-related growth retardation. Possible reasons for the differences of somatotroph morphology observed in different DMD models are discussed.

Somatic gene editing ameliorates skeletal and cardiac muscle failure in pig and human models of Duchenne muscular dystrophy

Frameshift mutations in the DMD gene, encoding dystrophin, cause Duchenne muscular dystrophy (DMD), leading to terminal muscle and heart failure in patients. Somatic gene editing by sequence-specific nucleases offers new options for restoring the DMD reading frame, resulting in expression of a shortened but largely functional dystrophin protein. Here, we validated this approach in a pig model of DMD lacking exon 52 of DMD (DMDΔ52), as well as in a corresponding patient-derived induced pluripotent stem cell model. In DMDΔ52 pigs1, intramuscular injection of adeno-associated viral vectors of serotype 9 carrying an intein-split Cas9 (ref. 2) and a pair of guide RNAs targeting sequences flanking exon 51 (AAV9-Cas9-gE51) induced expression of a shortened dystrophin (DMDΔ51-52) and improved skeletal muscle function. Moreover, systemic application of AAV9-Cas9-gE51 led to widespread dystrophin expression in muscle, including diaphragm and heart, prolonging survival and reducing arrhythmogenic vulnerability. Similarly, in induced pluripotent stem cell-derived myoblasts and cardiomyocytes of a patient lacking DMDΔ52, AAV6-Cas9-g51-mediated excision of exon 51 restored dystrophin expression and amelioreate skeletal myotube formation as well as abnormal cardiomyocyte Ca2+ handling and arrhythmogenic susceptibility. The ability of Cas9-mediated exon excision to improve DMD pathology in these translational models paves the way for new treatment approaches in patients with this devastating disease.

Targeting bromodomain-containing protein 4 (BRD4) inhibits MYC expression in colorectal cancer cells

The transcriptional regulator BRD4 has been shown to be important for the expression of several oncogenes including MYC. Inhibiting of BRD4 has broad antiproliferative activity in different cancer cell types. The small molecule JQ1 blocks the interaction of BRD4 with acetylated histones leading to transcriptional modulation. Depleting BRD4 via engineered bifunctional small molecules named PROTACs (proteolysis targeting chimeras) represents the next-generation approach to JQ1-mediated BRD4 inhibition. PROTACs trigger BRD4 for proteasomale degradation by recruiting E3 ligases. The aim of this study was therefore to validate the importance of BRD4 as a relevant target in colorectal cancer (CRC) cells and to compare the efficacy of BRD4 inhibition with BRD4 degradation on downregulating MYC expression. JQ1 induced a downregulation of both MYC mRNA and MYC protein associated with an antiproliferative phenotype in CRC cells. dBET1 and MZ1 induced degradation of BRD4 followed by a reduction in MYC expression and CRC cell proliferation. In SW480 cells, where dBET1 failed, we found significantly lower levels of the E3 ligase cereblon, which is essential for dBET1-induced BRD4 degradation. To gain mechanistic insight into the unresponsiveness to dBET1, we generated dBET1-resistant LS174t cells and found a strong downregulation of cereblon protein. These findings suggest that inhibition of BRD4 by JQ1 and degradation of BRD4 by dBET1 and MZ1 are powerful tools for reducing MYC expression and CRC cell proliferation. In addition, downregulation of cereblon may be an important mechanism for developing dBET1 resistance, which can be evaded by incubating dBET1-resistant cells with JQ1 or MZ1.

Tenofovir disoproxil fumarate/emtricitabine is associated with a higher risk of hypocalcemia compared to abacavir/lamivudine - results from a German cohort study

Hyperparathyroidism has been described in people living with HIV undergoing tenofovir disoproxil fumarate (TDF)-containing antiretroviral therapy (ART), but differences in calcium levels have never been investigated in detail. We aimed to compare the prevalence of hypocalcemia between patients with and without TDF-containing ART. The patients and methods were a retrospective cohort study in HIV-infected adult patients receiving dolutegravir and either abacavir (ABC)/lamivudine (3TC) or TDF/emtricitabine in a single center in Munich, Germany. Of 172 patients, 126 (73.3%) were male and the median age was 48.5 years (interquartile range 42-54). Average calcium levels were 2.24 (2.21-2.29) mmol/l and 2.21 (2.16-2.26) mmol/l (P < 0.001) with a prevalence of at least one episode of total calcium <2.12 mmol/l of 16.2 and 34.4% in the groups treated with ABC/3TC and TDF/emtricitabine, respectively (P = 0.006). TDF use was independently associated with the occurrence of albumin-corrected calcium levels of <2.12 mmol/l (odds ratio: 6.7 [1.3-35.6]; P = 0.025). Hypocalcemia seems to occur more often in TDF-treated patients. Further research into hypocalcemia with TDF and potential cardiovascular effects may be of benefit based on these findings.

Similar long-term efficacy of dual therapy containing raltegravir and a boosted protease inhibitor versus standard triple therapies in pretreated HIV-1-infected patients in a retrospective, real-life cohort of 14 years

OBJECTIVES

Raltegravir is used in many antiretroviral combinations, but its use in treatment-experienced patients without knowledge of baseline resistance is discussed controversially as a number of comparative studies have shown a higher rate of virological failure. However, it has been used frequently for the management of treatment failure, as it was the first integrase inhibitor to become available, and thus offered new options for patients with multiple resistance. The strategic use of raltegravir in this setting is examined in this study.

METHODS

In order to examine the efficacy of raltegravir in second and later lines of antiretroviral combinations, data for 740 patients from three clinical cohorts were analysed with a focus on the combinations that were used. These were stratified into the combination of two nonnucleoside reverse transcriptase inhibitors and raltegravir (2NRTIs + RAL), the combination of a boosted protease inhibitor and raltegravir (bPI + RAL), and other raltegravir-containing combinations.

RESULTS

The overall rate of virological suppression to < 50 HIV-1 RNA copies/mL was 69.5%. Although the baseline rate of virological suppression was higher for 2NRTIs + RAL than for the other strata, the outcomes were similar for all three groups at weeks 24, 48, 72 and 96.

CONCLUSIONS

These data indicate that, in a real-life setting, raltegravir can be used with a high virological success rate in treatment-experienced patients, and that the different combinations analysed (2NRTIs + RAL, bPI + RAL and others) show comparable rates of virological suppression.

Pain and Cognition in Multiple Sclerosis

Objective

The goal of the present study was to examine the relationship between pain and cognition in patients with multiple sclerosis.

Design

Cross-sectional.

Setting

Nursing home and personal environment of the investigators.

Subjects

Two groups of participants were included: 91 patients with multiple sclerosis and 80 matched control participants.

Methods

The level of pain was measured by the following pain scales: Number of Words Chosen-Affective, Colored Analogue Scale for pain intensity and suffering from pain, and the Faces Pain Scale. Mood was tested by administering the Beck Depression Inventory and the Symptom Check List-90 anxiety and depression subscale. Global cognitive functioning was assessed by the Mini Mental State Examination. Memory and executive functions were assessed by several neuropsychological tests.

Results

Multiple sclerosis (MS) patients scored significantly lower than control participants on the majority of the neuropsychological tests. The MS patients experienced more pain compared with control participants, despite the fact that they were taking significantly more pain medication. No significant correlation was observed between cognition and pain in MS patients. Verbal working memory explained 10% of pain intensity (trend). Mood appeared to be a significant predictor of pain in patients with multiple sclerosis.

Conclusion

The lack of a relationship between cognition and pain might be explained by the fact that, compared with control participants, patients with multiple sclerosis activate other non-pain-related areas to perform executive functions and memory tasks.

A paternal methyl donor-rich diet altered cognitive and neural functions in offspring mice

Dietary intake of methyl donors, such as folic acid and methionine, shows considerable intra-individual variation in human populations. While it is recognized that maternal departures from the optimum of dietary methyl donor intake can increase the risk for mental health issues and neurological disorders in offspring, it has not been explored whether paternal dietary methyl donor intake influences behavioral and cognitive functions in the next generation. Here, we report that elevated paternal dietary methyl donor intake in a mouse model, transiently applied prior to mating, resulted in offspring animals (methyl donor-rich diet (MD) F1 mice) with deficits in hippocampus-dependent learning and memory, impaired hippocampal synaptic plasticity and reduced hippocampal theta oscillations. Gene expression analyses revealed altered expression of the methionine adenosyltransferase Mat2a and BK channel subunit Kcnmb2, which was associated with changes in Kcnmb2 promoter methylation in MD F1 mice. Hippocampal overexpression of Kcnmb2 in MD F1 mice ameliorated altered spatial learning and memory, supporting a role of this BK channel subunit in the MD F1 behavioral phenotype. Behavioral and gene expression changes did not extend into the F2 offspring generation. Together, our data indicate that paternal dietary factors influence cognitive and neural functions in the offspring generation.

202 Targeting Galactosyl-α-1,3-Galactose (αGal) Epitopes for Multi-Species Embryo Immunosurgery

Immunosurgical isolation of the inner cell mass (ICM) from blastocysts is based on complement-mediated lysis of antibody-coated trophectoderm (TE) cells. Conventionally, anti-species antisera, containing antibodies against multiple undefined TE cell epitopes, have been used as antibody source. We previously generated α-1,3-galactosyltransferase deficient (GTKO) pigs to prevent hyper-acute rejection of pig-to-primate xenotransplants. Because GTKO pigs lack galactosyl-α-1,3-galactose (αGal) but are exposed to this antigen (e.g. αGal on gut bacteria), they are expected to produce anti-αGal antibodies. In this study, we examined whether serum from GTKO pigs can be used as a novel antibody source for embryo immunosurgery. First, the presence of αGal epitopes in mouse (E3.5), rabbit (Day 4), pig (Day 6–7), and bovine (Day 7–8) blastocysts was examined by staining with fluorescein isothiocyanate (FITC)-conjugated BSI-B4 lectin (Sigma, St. Louis, MO, USA) that binds αGal. Expression of αGal epitopes on the surface of TE cells was detected in blastocysts of all examined species. Next, pig blastocysts were incubated with a medium containing GTKO pig serum. Swollen TE cells were observed in some of the blastocysts already after 2 min and, after 10 min, almost all TE cells of these blastocysts were completely destroyed. No lysis was recorded when the same experiment was done with wild-type pig serum, suggesting the presence of sufficient quantities of anti-αGal antibodies in GTKO serum to coat the TE cells and induce their complement-mediated lysis. Finally, GTKO serum was systematically tested for immunosurgery. Zona-free blastocysts of the species mentioned above were incubated with heat-inactivated GTKO pig serum for 1 h at 38°C. After washing, the blastocysts were labelled with Hoechst 33342 and TE was stained with FITC-conjugated concanavalin A (ConA) to distinguish the ICM from TE cells. Eventually, the blastocysts were individually incubated in complement solution for 30 to 40 min. Complement-mediated lysis of TE cells was efficiently induced in mouse, rabbit, pig, and bovine blastocysts (10/10, 7/7, 10/10, and 5/6, respectively), and intact ICM were successfully recovered from all species (100, 100, 60, and 80%, respectively). Double fluorescent staining with Hoechst 33342 and ConA clearly showed that the majority of isolated ICM was not contaminated with TE cells. Our study demonstrates that GTKO pig serum is a reliable source of antibodies targeting the αGal epitope of TE cells. Major advantages of using GTKO serum for embryo immunosurgery are (1) that it can be produced easily in large batches, thus reducing experimental variation; and (2) that it reacts with a large number of different species, except for humans, apes, and old world monkeys that lack αGal epitopes. Interesting applications include the preparation of TE and ICM for transcriptome profiling or chimeric embryo complementation experiments. This work is supported by the German Research Council (TR-CRC 127).

59 Selected Reaction Monitoring-Based Absolute Quantification of Developmentally Relevant Proteins in Early Bovine Embryos Reveals Differences Between In Vitro and In Vivo Embryo Culture and Between Different Maternal Metabolic Stages

Early embryogenesis is a highly complex developmental process, accompanied by a plethora of changes at the morphological and molecular level. Particularly at the level of proteins, these changes are still poorly characterised and understood. During the first cleavages, the embryo depends mainly on maternal transcripts and proteins that were accumulated and stored during oogenesis until embryonic genome activation (EGA) occurs. In the bovine system, the major EGA takes place at the 8- to 16-cell stage. However, we recently demonstrated by liquid chormatography-tandem mass spectrometry (LC-MS/MS)-based holistic proteome approaches that despite transcriptional and translational silencing, the proteome of the early embryo is highly dynamic (Deutsch et al. 2014; Demant et al. 2015). Based on these findings, we established a targeted LC-MS/MS approach based on multiplexed selected reaction monitoring (mSRM), which facilitates an absolute quantification of 27 proteins relevant in early embryogenesis. Each protein is targeted by 2 independent peptides to facilitate highly reliable quantifications. Nine characteristic developmental stages from germinal vesicle oocyte to hatched blastocyst were analysed (n = 6 per stage), and absolute protein contents are reported as femtomole per embryo, with limits of quantification (LOQ) down to 100 attomoles per embryo. Based on their abundance profiles during maturation, zygote formation, and embryonic development, the 27 proteins could be grouped into 6 SOTA clusters. By principal component analysis (PCA), absolute SRM quantifications of only 9 selected proteins were shown to discriminate between all 9 developmental stages analysed, thus providing molecular fingerprints significant for each developmental stage. We used the 27-plex SRM assay as a powerful readout tool and demonstrated substantial quantitative differences between embryos derived from a well-established in vitro culture system and embryos transferred into the oviduct of living animals for 2 days (in vivo culture). Furthermore, in vivo development of embryos in animals differing in their metabolic stress levels led to significant alterations in the 27-plex SRM profiles. This work was supported by a grant to GJA from Deutsche Forschungsgemeinschaft DFG FOR1041 ‘Germ Cell Potential’ AR 362/7-1 and European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement n° 312097 - FECUND.

108 Single-Cell RNA Sequencing Reveals Blastomere Heterogeneity and Early Lineage Specification Events in Bovine Embryos During Major Embryonic Genome Activation

During early embryonic stages, gene products generated by the embryo acquire control over embryonic development. At the 8- to 16-cell stage, major embryonic genome activation (EGA) occurs in bovine embryos. Morphological observations, such as size of blastomeres and distribution of microvilli, suggest heterogeneity of individual cells already at this developmental stage. To study this heterogeneity on the transcriptome level, we performed single-cell RNA sequencing (scRNA-seq) of 161 blastomeres from 14 in vitro-produced bovine embryos at Day 2 and Day 3 post-fertilization. After removing the zona pellucida, blastomeres were mechanically separated in Ca2+- and Mg2+-free PBS, individually collected, and lysed. Complementary DNA libraries were prepared by the single cell RNA-barcoding and sequencing (SCRB-Seq) protocol. Exogenous RNA was added for quality control and cell specific barcodes and unique molecular identifiers (UMI) were used to enable pooling of libraries and to exclude PCR duplicates, respectively. After sequencing (Illumina HiSEqn 1500; 50 nt reads; Illumina Inc., San Diego, CA, USA), UMI were counted with the published Drop-seq pipeline (45,000 UMI on average per library) and cells with UMI count <2.000 were removed. Data were normalized based on UMI and non-supervised clustering analyses of single-cell data were performed (SC3 and M3Drop R packages). The transcriptome profiles of all individual cells were assigned to 6 clusters with specific sets of genes. Sorting cells according to their transcriptome profiles by the CellTree R package (Bioconductor; https://bioconductor.org/packages/release/bioc/html/cellTree.html) resulted in a linear pseudo-timeline. Furthermore, this tool identified 6 groups of genes (topics). Each of them showed an over-representation of distinct Gene Ontology (GO) terms; topic 1, “translation” and “cell division”; topic 2, GO terms involved in translation, RNA splicing and cell division; topic 3, “translation”; topic 4, “ATP synthesis coupled proton transport”; topic 5, “mitochondrial translational elongation”; topic 6, “organic hydroxyl compound transport”. Moreover, increased expression of PCDH10 (protocadherin 10) was observed in the biologically pseudo-ordered more advanced blastomeres. This gene is known to be predominantly expressed in the inner cell mass (ICM) at the blastocyst stage, suggesting that these cells might become ICM. In summary, our study reveals developmental heterogeneity and hints to early lineage specification events in bovine embryos at the time of major EGA.

67 Influence of Metabolic Status and Genetic Merit for Fertility on Proteomic Composition of Bovine Uterine Luminal Fluid

Intensive selection strategies focusing on increased milk yield over several decades has been associated with a decline in fertility in dairy cows. To study the effect of the genetic merit for fertility and the metabolic status of the female on the oocyte, early embryo and the maternal environment, 2 animal models were established. The genetic merit model involved Holstein heifers with a low (LFH) and high fertility (HFH) index and heifers from the Montbéliarde breed (MBD), known to have good reproductive performance. The metabolic model comprised samples from maiden heifers (MH), postpartum lactating cows (Lact), and non-lactating cows (dried off immediately after calving; Dry). A common pool of Day 7 embryos recovered from superovulated and artificially inseminated Holstein heifers were transferred into synchronised recipients (1/recipient) of the above-mentioned animal models and uterine lumen fluid (ULF) of confirmed pregnant animals was recovered on Day 19 post-oestrus. As communication between the conceptus and the uterine environment is crucial for the successful establishment of pregnancy, we analysed uterine luminal fluid of pregnant cows from both models using a holistic proteomic approach. Using nano-liquid chromatography-tandem mass spectrometry analysis combined with a label-free quantification approach, we analysed the uterine luminal fluid from the uterine horn ipsilateral to the corpus luteum (where the conceptus was located in all cases). A total of 2127 proteins were quantified in all samples of both models. Among this set of proteins, 458 were found to differ significantly (P-value < 0.05) in abundance between the groups of the genetic model, and 141 were altered in abundance in the metabolic model. The majority of proteome differences in ULF samples was found comparing HFH to the LFH group (358) and between Dry and Lact cows (70) in the metabolic model. Evaluation of this dataset using bioinformatic tools comprising DAVID GO and gene set enrichment analysis revealed that the affected proteins were predominantly assigned to the terms “translation”, “monosaccharide metabolic process”, “enzyme inhibitor activity”, “lipid binding”, and “response to oxidative stress”. Our study revealed that metabolic status and genetic merit for fertility lead to quantitative molecular differences at the level of proteins in uterine fluid of pregnant animals, thus altering the microenvironment for the early conceptus. This research was funded by European Union Seventh Framework Programme FP7/2007-2013 under grant agreement no. 312097 (‘FECUND’).

OmoMYC blunts promoter invasion by oncogenic MYC to inhibit gene expression characteristic of MYC-dependent tumors

MYC genes have both essential roles during normal development and exert oncogenic functions during tumorigenesis. Expression of a dominant-negative allele of MYC, termed OmoMYC, can induce rapid tumor regression in mouse models with little toxicity for normal tissues. How OmoMYC discriminates between physiological and oncogenic functions of MYC is unclear. We have solved the crystal structure of OmoMYC and show that it forms a stable homodimer and as such recognizes DNA in the same manner as the MYC/MAX heterodimer. OmoMYC attenuates both MYC-dependent activation and repression by competing with MYC/MAX for binding to chromatin, effectively lowering MYC/MAX occupancy at its cognate binding sites. OmoMYC causes the largest decreases in promoter occupancy and changes in expression on genes that are invaded by oncogenic MYC levels. A signature of OmoMYC-regulated genes defines subgroups with high MYC levels in multiple tumor entities and identifies novel targets for the eradication of MYC-driven tumors.

62 BOVINE OCT4 (POU5F1) KNOCKOUT EMBRYOS FAIL DURING THE SECOND LINEAGE DIFFERENTIATION DUE TO LOSS OF NANOG

We generated a CRISPR/Cas9 mediated knockout (KO) of the OCT4 gene in adult fibroblasts, where biallelic deletion of a single nucleotide leads to a frameshift mutation. Through reconstruction of embryos by somatic cell NT, we were able to study the role of OCT4 during pre-implantation development until Day 7 in vitro. The presence of OCT4 protein was evaluated after immunofluorescent staining by confocal laser scanning microscopy of Day 5 morulae and Day 7 blastocysts; somatic cell NT embryos reconstructed from nontransfected cells of the same source served as control. Whereas control morulae expressed OCT4 in all cells, OCT4 KO morulae showed expression in only 67.8 ± 11.1% (mean ± SD, n = 6) of cells and overall intensity was decreased. By Day 7, no expression of OCT4 was detected in OCT4 KO blastocysts (n = 24), suggesting that maternal stores of the OCT4 protein had decayed. In contrast, control blastocysts (n = 20) showed OCT4 expression ubiquitously in both inner cell mass (ICM) and trophectoderm (TE). Simultaneously to the OCT4 staining, we differentially stained ICM and TE with the TE specific marker CDX2 and counterstained cell nuclei with 4′,6-diamidino-2-phenylindole. No significant differences between OCT4 KO Day 7 blastocysts and controls were detected in total cell numbers (89.6 ± 27.5 v. 96.3 ± 38) and percentage of CDX2 positive cells (50.7 ± 16.8% v. 59.0 ± 20.8%) (P > 0.05, mean ± SD, unpaired, two-tailed t-test). To analyse the role of OCT4 during the second lineage differentiation, we stained Day 5 morulae and Day 7 blastocysts for the epiblast and hypoblast specific markers NANOG and GATA6, respectively. In morulae, both markers were present and co-expressed in OCT4 KO and control embryos. By Day 7, control blastocysts (n = 6) already showed the typical salt and pepper distribution of NANOG and GATA6 positive cells, but expression was not mutually exclusive in all cells and also not restricted to ICM. OCT4 KO embryos lost all NANOG expression at Day 7 blastocyst stage (n = 8) and only stained positive for GATA6 in both TE and ICM. We conclude that OCT4 is not required for the quantitative allocation of cells to either the ICM or the TE during the first lineage differentiation, as total cell number and percentage of CDX2 positive cells was unchanged. Additionally, expression of NANOG seems to be OCT4 dependent and OCT4 KO embryos fail to establish the epiblast lineage—unlike mouse Oct4 KO embryos, where developmental failure was connected to loss of GATA6 expression during second lineage differentiation. This work was funded by the Bavarian Research Foundation (AZ-1031–12).

125 INCOMPLETE COMPENSATORY UP-REGULATION OF X-LINKED GENES IN BOVINE GERMLINE, EARLY EMBRYOS, AND SOMATIC TISSUES

The maintenance of a proper gene dosage is essential in cellular networks. To resolve the dosage imbalance between eutherian females (XX) and male (XY), X chromosome inactivation (XCI) occurs in females, while X-chromosome dosage compensation up-regulates the active X to balance its expression with that of autosome pairs [Ohno’s hypothesis; Ohno 1967 Sex Chromosomes and Sex-linked Genes (Springer-Verlag), p. 99]. These phenomena have been well studied in humans and mice, despite many controversies over the existence of such up-regulation. Using RNA sequencing data, we determined X chromosome dosage compensation in the bovine by analysing the global expression profiles of germ cells, embryos, and somatic tissues. Eight bovine RNA-seq data sets were obtained in from the Gene Expression Omnibus, covering bovine immature/mature oocytes (GSE59186 and GSE52415), pre-implantation conceptuses (GSE59186, GSE52415, and GSE56513), extra-embryonic tissues (PRJNA229443), and male/female somatic tissues (GSE74076, GSE63509, PRJEB6377, and GSE65125). The RNAseq data were trimmed and non-uniquely (paralogs included) mapped to the bovine reference genome assembly UMD3.1.1 using Hisat2 (version 2.0.5) aligner. The mRNA level of each gene, estimated by transformed transcripts per kilobase million was quantified by IsoEM (version 1.1.5). These RNA-seq data sets represented 4 chromosome scenarios in cells: XXXX:AAAA (diploid immature oocyte with DNA duplication), XX:AA (haploid mature oocyte with DNA duplication), XX:AA and X:AA (gradual changed X status in bovine pre-implantation conceptuses), and X:AA (extra-embryonic tissues and somatic cells in female with one active X or XY male) were analysed for dosage compensation. A total of 959 X-linked genes and 20,316 autosome genes were used to calculate the relative X to autosomal gene (A) expression (RXE): log2 (X expression) − log2 (A expression). The following dosage determinations were made: RXE values ≥ 0: complete dosage compensation (or X: A ratio ≥ 1); RXE values < 0: in-complete dosage compensation; RXE value = −1: no dosage compensation (or X: A ratio = 0.5). Our analyses showed a decreased RXE after fertilization, from −0.33 in matured oocytes to −0.50 at the 2-cell stage, indicating that the sperm that undergo meiotic sex chromosome inactivation (MSCI) bring in inactive X chromosomes to the matured oocytes. Subsequently, the activation of the bovine embryonic genome at the 4- to 8-cell stage increased RXE from −0.54 to −0.05. This was followed by a sharp RXE decline from −0.02 at the 16-cell stage, 0.1 at the 32-cell stage to −0.29 at the compact morula stage, which is known as paternal X inactivation stage in the bovine. Finally, RXE was stabilised from blastocysts −0.19 through the Day 19 conceptuses −0.25 to somatic tissue average −0.21 with a pattern of incomplete X compensation. These findings support X expression up-regulation as proposed by Ohno. No significant RXE differences were observed between bovine female and male somatic tissues, further supporting Ohno’s hypothesis, which predicts a balance in the expression of X-linked genes to that of autosomes. This study confirms Ohno’s hypothesis of X dosage compensation in bovine germ cells, early embryos, and somatic tissues.

Higher rates of neuropsychiatric adverse events leading to dolutegravir discontinuation in women and older patients

OBJECTIVES

Dolutegravir (DTG), a second-generation integrase strand transfer inhibitor (INSTI), is now among the most frequently used antiretroviral agents. However, recent reports have raised concerns about potential neurotoxicity.

METHODS

We performed a retrospective analysis of a cohort of HIV-infected patients who had initiated an INSTI in two large German out-patient clinics between 2007 and 2016. We compared discontinuation rates because of adverse events (AEs) within 2 years of starting treatment with dolutegravir, raltegravir or elvitegravir/cobicistat. We also evaluated factors associated with dolutegravir discontinuation.

RESULTS

A total of 1950 INSTI-based therapies were initiated in 1704 patients eligible for analysis within the observation period. The estimated rates of any AE and of neuropsychiatric AEs leading to discontinuation within 12 months were 7.6% and 5.6%, respectively, for dolutegravir (n = 985), 7.6% and 0.7%, respectively, for elvitegravir (n = 287), and 3.3% and 1.9%, respectively, for raltegravir (n = 678). Neuropsychiatric AEs leading to dolutegravir discontinuation were observed more frequently in women [hazard ratio (HR) 2.64; 95% confidence interval (CI) 1.23-5.65; P = 0.012], in patients older than 60 years (HR: 2.86; 95% CI: 1.42-5.77; P = 0.003) and in human leucocyte antigen (HLA)-B*5701-negative patients who initiated abacavir at the same time (HR: 2.42; 95% CI: 1.38-4.24; P = 0.002).

CONCLUSIONS

In this large cohort, the rate of discontinuation of dolutegravir because of neuropsychiatric adverse events was significantly higher than for other INSTIs, at almost 6% within 12 months. Despite the limitations of this retrospective study, the almost three-fold higher discontinuation rates observed amongst women and older patients underscore the need for further investigation, especially in patient populations usually underrepresented in clinical trials.

Prosthodontic decision-making relating to dentitions with compromised molars: the perspective of Swedish General Dental Practitioners

The aim of this investigation was to study the clinical prosthodontic decision-making process relating to dentitions with compromised molars among Swedish general dental practitioners (GDPs). Eleven Swedish GDPs were purposively selected, and all agreed to participate. Then, in-depth, semi-structured interviews were conducted and covered treatment considerations concerning two authentic patient cases, initially with complete dental arches, and later, a final treatment based on a shortened dental arch (SDA) was discussed. The cases involved patients with compromised teeth situated mainly in the molar regions. One patient suffered from extensive caries and the other from severe periodontal disease. Qualitative content analysis was used to analyse the data. In the systematic analysis, two main categories were identified: holistic and functional approach. Among the interviewed GDPs, focus was put on patients' needs, background history and motivation for treatment as well as the preservation of molar support. Within the limitations of this study, the following can be concluded: keeping a dental arch with molars seems to be important to Swedish general dental practitioners. The SDA concept does not seem to have a substantial impact on the prosthodontic decision-making relating to dentitions with compromised molars. The dentist's experiences, as well as colleagues' or consulting specialist advice together with aetiological factors and the patient's individual situation, influence the decision-making more than the SDA concept. The conflicting results in the prosthetic decision-making process concerning the relevance of age and the need for molar support need further investigation, for example based on decisions made in the dentist's own clinical practice.

19 DIRECT INTRODUCTION OF GENE CONSTRUCTS INTO THE PRONUCLEUS-LIKE STRUCTURE OF CLONED EMBRYOS: A NEW STRATEGY FOR THE GENERATION OF GENETICALLY MODIFIED PIGS

Because of a rising demand for complex porcine disease models for biomedical research, the approaches for their generation need to be adapted. In this study we describe the direct introduction of a gene construct into the pronucleus (PN)-like structure of cloned embryos as a new strategy for the generation of genetically modified pigs, termed “nuclear injection.” This new strategy could allow adding large constructs into cloned embryos with a genetically modified background. Moreover, the generation of multiple transgenic pigs based on already existing transgenic cells could be facilitated due to a reduction of recloning steps. To evaluate the reliability of this approach, developmental ability of the embryos in vitro or in vivo and integration or expression efficiency of the transgene were examined. Somatic cell NT using in vitro matured oocytes was performed. Wild-type cells were used as nuclear donors. Centrifugation was done 10 h after activation for visualisation of a PN-like structure. Subsequently, linearized pmaxGFP (10 ng μL–1; Amaxa Biosystems) was directly injected into the PN-like structure of the cloned embryos. Expression efficiency in blastocysts generated by nuclear injection was compared to blastocysts generated by the classical PN injection using in vitro-produced zygotes. Injected embryos were transferred to recipient pigs without green fluorescent protein (GFP) selection, and fetuses collected at Day 68 were characterised for their integration and expression pattern of the transgene. Eighty percent of the reconstructed embryos (633/787) exhibited a PN-like structure, which made them available for the method. Green fluorescent protein fluorescence was observed in about half of total blastocysts (52.5%, 21/40), which was comparable to classical PN injection (68.4%, 28/41). Green fluorescent protein fluorescence of blastocysts ranged from mosaic to uniform patterns. In total, 478 pmaxGFP-injected embryos were transferred into 4 recipients, 4 fetuses were collected from one of them. In one of the fetuses that developed normally, the integration of the transgene was confirmed by PCR in different major organs from all 3 primary germ layers and placenta. The integration pattern of the transgene was mosaic (43 out of 84 single-cell colonies established from kidney were positive for GFP DNA by PCR). However, the proportion of GFP-expressing cells was very low (5 out of 84 colonies expressed GFP), which might indicate silencing of transgene expression. Our pilot study demonstrated that the direct introduction of gene constructs into cloned embryos could be a new strategy for the generation of genetically modified pigs. This approach could also be applied to rescue embryos with lethal knockouts by transfer of corresponding human genes, to generate pigs as bioreactors, e.g. for antibodies. This work was supported by the German Research Council – Transregio Collaborative Research Center 127 “Xenotransplantation.”

144 DOSAGE COMPENSATION AND X-LINKED GENE EXPRESSION IN BOVINE IN VIVO AND IN VITRO EMBRYOS

In human and mouse diploid cells and gametes, expression levels of X-linked genes are hypothesised to balance with those of autosomal genes (Ohno’s “dosage compensation”). Such a phenomenon, however, has not been systematically studied in cattle or compared between in vivo and in vitro embryos. Using RNA-seq data, we compared dosage compensation and expression differences of X-linked genes in bovine in vitro and in vivo oocytes and embryos. RNA-seq datasets GSE59186 and GSE52415 were non-uniquely (paralogs included) mapped to the bovine reference genome assembly UMD3.1 using tophat2. Cufflinks v1.0.3 was used to estimate fragments per kb of exon per million fragments (FPKM), which were then log2-transformed. In order to assess overall patterns of chromosomal gene expression without bias, statistical outliers were removed. A total of 12 928 X-linked transcripts were used to calculate the relative X to autosomal gene (A) expression (RXE): log2 (X expression) – log2 (A expression) for dosage compensation. Values ≥0 indicate dosage compensation (or X : A ratio ≥ 1); values <0 indicate incomplete dosage compensation; value = –1 indicates no dosage compensation (or X : A ratio = 0.5). Cuffdiff was used to identify differentially expressed genes between stages and the 2 datasets. Cuffnorm normalized FPKM for expression patterns, which were further clustered and graphed in R. Expression pattern distributions across regions on X were calculated by merging Cuffnorm output genes.attr_table to the expression pattern lists. The RXE values were higher than –1 in all embryonic stages studied, with in vitro embryos having higher RXE, suggesting some but incomplete dosage compensation and in vitro embryos exhibiting higher levels of X-gene expression. In vitro-produced immature oocytes and 4-cell embryos had RXE of 0, suggesting that both may be completely compensated. Additionally, embryos of the 2 sources exhibited significant differences in levels of X-gene expression at 4-cell to 8-cell and 16-cell to blastocyst stages. All expressed X-linked genes fell in 5 groups (patterns 1–5): increased, decreased, increased and then decreased, constant, decreased and then increased. Patterns 1 to 4 were seen in both datasets, whereas pattern 5 was only present in vitro, which may be why in vitro embryos had higher dosage of X. We further found that these expression patterns correlated with the genes’ proximity to the X inactivation centre (Xic: ~82 Mb): the highly dynamic patterns 3 and 5 were associated with proximity to Xic, supporting the notion that the Xist RNA spreads along the X through the Xic. In vivo and in vitro bovine oocytes and embryos have undergone some degree but incomplete dosage compensation. Expression of X-linked genes is correlated with their proximity to Xic. Globally, in vivo and in vitro embryos exhibit major differences in levels of X-gene expression.

The target cell of transformation is distinct from the leukemia stem cell in murine CALM/AF10 leukemia models

The CALM/AF10 fusion gene is found in various hematological malignancies including acute myeloid leukemia (AML), T-cell acute lymphoblastic leukemia and malignant lymphoma. We have previously identified the leukemia stem cell (LSC) in a CALM/AF10-driven murine bone marrow transplant AML model as B220+ lymphoid cells with B-cell characteristics. To identify the target cell for leukemic transformation or 'cell of origin of leukemia' (COL) in non-disturbed steady-state hematopoiesis, we inserted the CALM/AF10 fusion gene preceded by a loxP-flanked transcriptional stop cassette into the Rosa26 locus. Vav-Cre-induced panhematopoietic expression of the CALM/AF10 fusion gene led to acute leukemia with a median latency of 12 months. Mice expressing CALM/AF10 in the B-lymphoid compartment using Mb1-Cre or CD19-Cre inducer lines did not develop leukemia. Leukemias had a predominantly myeloid phenotype but showed coexpression of the B-cell marker B220, and had clonal B-cell receptor rearrangements. Using whole-exome sequencing, we identified an average of two to three additional mutations per leukemia, including activating mutations in known oncogenes such as FLT3 and PTPN11. Our results show that the COL for CALM/AF10 leukemia is a stem or early progenitor cell and not a cell of B-cell lineage with a phenotype similar to that of the LSC in CALM/AF10+ leukemia.