Repeated exposure to rats has persistent genotype-dependent effects on learning and locomotor activity of apolipoprotein E knockout and C57Bl/6 mice

Recently we have shown that an experimentally controlled encounter of mice with rats ("rat stress") some time before actual behavioural testing either abolished or induced behavioural deficits in the Morris water maze, depending on the genotype of the mice: apolipoprotein E knockout mice (apoE0/0) and wild type mice. Here we report that previous rat stress: (i) facilitated learning of a circular hole board task in apoE0/0 mice and impaired learning in wild type mice, thereby abolishing genotype-dependent differences; (ii) although both genotypes preferred the dark compartment when tested in a light/dark-preference task 3 months after rat stress, locomotor activity was reduced in apoE0/0 and increased in wild type mice, thus genotype differences were amplified; (iii) both genotypes responded with a differential regulation of bodyweight during exposure to rats, which persisted for 3 months: apoE0/0 mice decreased while wild type mice increased their body weight; (iv) the high emotional reactivity (defecation boli) measured during behavioural tasks was not affected in apoE0/0 mice, whereas a decrease was observed in wild type mice. Thus, pre-experimental confrontation of mice with rats shifts behaviour and physiological responses and eliminates some of the genotype-dependent differences.

Treatment of male infertility due to sperm surface antibodies: IUI or IVF?

This prospectively designed study was aimed at comparing the results of two different treatment protocols in 29 infertile couples with proven male immunological infertility, i.e. a positive (>50%) mixed antiglobulin reaction (MAR) test (IgG and/or IgA). In the first protocol (group I, n = 14) couples were treated with ovarian stimulation/ intrauterine insemination (IUI), followed by in-vitro fertilization (IVF) if no pregnancy occurred after three IUI cycles. In the second protocol (group II, n = 15), patients were treated with IVF as a first choice procedure. The decision to follow protocol 1 or 2 was made by the couples after information about financial costs and expected success rates (according to the literature) for both treatment options. In group I, nine patients (64.3%) conceived after a maximum of three IUI cycles whereas seven patients (46.6%) of group II became pregnant during the first IVF cycle. The take-home baby rate per started IUI or IVF cycle was 27.3% (9/33) and 44.4% (16/36) respectively with a take-home baby rate of 64.3% after three IUI cycles and 93.3% after three IVF attempts. To conclude, both IUI and IVF yielded unexpectedly high pregnancy rates in this selected group of patients with long-standing infertility due to sperm surface (predominantly IgG) antibodies. Since cost benefit analysis comparing superovulation IUI with IVF may favour a course of four IUI cycles, we advocate superovulation IUI as the first line therapy in male immunological infertility.

Effect of training on endoscopic intracorporeal knot tying

Training in endoscopic, intracorporeal knot tying, was evaluated in 29 obstetrics and gynaecology trainees who performed 100 consecutive intracorporeal, two turn, flat, square knots. An obvious learning curve was observed. With training the quality of the knots increased, whereas the mean duration to tie a knot decreased from 277 +/- 114 to 67 +/- 27 s for the first 10 and the last 10 knots respectively. The initial and final duration of knot tying were lower in more experienced trainees, as estimated by the year of training or the Royal College of Obstetrics and Gynaecology (RCOG) level of experience. More specifically, duration of knot tying was shorter when more diagnostic laparoscopies, laparoscopic sterilizations or adnexectomies had been performed. This effect of previous experience was however limited compared with the overall effect of training. Previous passive experience, however, as determined by the number of assisted or observed surgical interventions, did not affect the learning curves. Speed of knot tying was slightly higher in trainees who spent more of their leisure time performing handicrafts than in trainees who were more interested in reading, but although significant, these differences were only marginal. In conclusion, the data show an important effect of training on the speed and quality of intracorporeal knot tying and confirm that learning curves improve with previous training.

Spatial and single-cell profiling of the metabolome, transcriptome and epigenome of the aging mouse liver

Tissues within an organism and even cell types within a tissue can age with different velocities. However, it is unclear whether cells of one type experience different aging trajectories within a tissue depending on their spatial location. Here, we used spatial transcriptomics in combination with single-cell ATAC-seq and RNA-seq, lipidomics and functional assays to address how cells in the male murine liver are affected by age-related changes in the microenvironment. Integration of the datasets revealed zonation-specific and age-related changes in metabolic states, the epigenome and transcriptome. The epigenome changed in a zonation-dependent manner and functionally, periportal hepatocytes were characterized by decreased mitochondrial fitness, whereas pericentral hepatocytes accumulated large lipid droplets. Together, we provide evidence that changing microenvironments within a tissue exert strong influences on their resident cells that can shape epigenetic, metabolic and phenotypic outputs.

Atypical binding of the neuronal POU protein N-Oct3 to noncanonical DNA targets. Implications for heterodimerization with HNF-3 beta

The capacity of POU proteins to recognize different DNA sequences and to bind target DNA in the form of monomers, cooperative dimers or heterodimers is important in relation to their transcriptional regulatory properties. The N-Oct3 neuron-specific protein binds to an octamer-like sequence (AAATAATGC) within the (-102/-72) neuronal promoter region of the human aromatic L-amino acid decarboxylase (AADC) gene. In this atypical case the POUh and POUs tetrameric subsites are spaced one nucleotide apart and in switched order as compared with the consensus octamer. Moreover this POU binding motif overlaps the hepatocyte nuclear factor HNF-3 beta binding site (TGCTCAGTAAA) which itself contains a heptamer-like sequence (CTCAGTA). Using the isolated DNA binding domains (DBD) of the two proteins, it is shown that, when binding to this unusual recognition sequence, N-Oct3 either exhibits noncooperative homodimerization or allows the simultaneous binding of the second transcription activator HNF-3 beta. CD studies indicate that the binding of N-Oct3 monomers/dimers and N-Oct3-HNF-3 beta heterodimers to the DNA induces conformational changes of both protein and DNA. Partial proteolysis/MALDI-MS was used in conjunction with molecular modelling to show that the protein conformational change resulting from binary N-Oct3/DNA complex formation occurs within the linker peptide joining the POUs and POUh subdomains. Furthermore, modelling the N-Oct3/HNF-3 beta/DNA ternary complex predicts a nucleotide rearrangement in the overlap region and an interaction between both transcription factors. In the light of our findings, which illustrate both site-dependent and site-independent protein and DNA conformational changes, general implications for the allosteric function of DNA response elements in transcriptional regulation are discussed.

Rupture of membranes before 26 weeks of gestation: outcome of 148 consecutive cases

AIMS

To assess the outcome of preterm prelabor rupture of the membranes (PPROM) before 26 weeks of gestation and to develop a prediction model for survival.

METHODS

148 consecutive cases of PPROM before 26 weeks of gestation, collected between 1988 and 1996, were retrospectively analyzed. A multivariate analysis (generalized estimating equations) of 21 process and 5 short and long term outcome variables was performed.

RESULTS

40 out of 148 children (27%) died before or during birth, 57 (38.5%) of the children survived more than 28 days, from which still 5 died after one month. Amongst the 52 survivors (35.1%), the Bayley Mental Development Index and Psychomotor Development Index at a corrected age of 7 months was normal in respectively 85.7% and 75.5% of the cases. At 6-7 years of age, 24 out of 33 children (73%) performed adequately at school. Sex, gestational age at PPROM, birth weight, the administration of steroids and interactions of steroid administration with sex and with gestational age at the time of PPROM largely determined the chances of survival.

CONCLUSIONS

Overall fetal survival after PPROM before 26 weeks of gestation was 35.1%. Survival can be predicted with an accuracy of 75%, a sensitivity of 85% and a specificity of 60%. More than 70% of the survivors behaved and performed adequately at school age, but 27% require special long-term attention and care.

Combined Osteopontin Blockade and Type 2 Classical Dendritic Cell Vaccination as Effective Synergetic Therapy for Conjunctival Melanoma

Angiogenesis and immune protection are essential at the onset of tumorigenesis. Angiogenesis serves to nourish the tumor, and prevention of immune defenses, for example, by dendritic cells (DCs), allows tumor growth. In this study, we investigated whether there are factors with dual functions that are both angiogenic and immunomodulatory and represent a therapeutic target. We analyzed 1) innate immune responses intratumorally and in draining lymph nodes and 2) angiogenic factors in conjunctival melanoma (CM), a potentially lethal malignant tumor at the ocular surface whose immune and vascular responses are largely unknown. For this purpose, an HGF-Cdk4R24C model in immunocompetent C57BL/6 mice was used and revealed that CD103- type 2 classical DC (cDC2s) were the most abundant DC subtype in healthy conjunctiva, whereas in CM, CD103- cDC2s, CD103+ type 1 cDCs, monocyte-derived DCs, and plasmacytoid DCs were significantly increased. In our analysis of angiogenic factors in CM, the examination of 53 angiogenesis-related factors that might interact with DCs identified osteopontin (OPN) as a major tumor-derived protein that interacts with DCs. Consistent with these findings, 3) a dual therapeutic strategy that inhibited tumor cell function by an OPN blocking Ab while enhancing the immune response by cDC2 vaccination resulted in 35% failure of tumor development. Moreover, tumor progression, monocyte-derived DC infiltration, and intratumoral angiogenesis were significantly reduced, whereas survival and CD8+ T cell infiltration were increased in treated mice compared with the control group. Therefore, we identified OPN blockade in combination with cDC2 vaccination as a potential future therapeutic intervention for early stages of CM by combining antiangiogenic and host immune stimulating effects.

An Approach to Intersectionally Target Mature Enteroendocrine Cells in the Small Intestine of Mice

Enteroendocrine cells (EECs) constitute only a small proportion of Villin-1 (Vil1)-expressing intestinal epithelial cells (IECs) of the gastrointestinal tract; yet, in sum, they build the largest endocrine organ of the body, with each of them storing and releasing a distinct set of peptides for the control of feeding behavior, glucose metabolism, and gastrointestinal motility. Like all IEC types, EECs are continuously renewed from intestinal stem cells in the crypt base and terminally differentiate into mature subtypes while moving up the crypt-villus axis. Interestingly, EECs adjust their hormonal secretion according to their migration state as EECs receive altering differentiation signals along the crypt-villus axis and thus undergo functional readaptation. Cell-specific targeting of mature EEC subtypes by specific promoters is challenging because the expression of EEC-derived peptides and their precursors is not limited to EECs but are also found in other organs, such as the brain (e.g., Cck and Sst) as well as in the pancreas (e.g., Sst and Gcg). Here, we describe an intersectional genetic approach that enables cell type-specific targeting of functionally distinct EEC subtypes by combining a newly generated Dre-recombinase expressing mouse line (Vil1-2A-DD-Dre) with multiple existing Cre-recombinase mice and mouse strains with rox and loxP sites flanked stop cassettes for transgene expression. We found that transgene expression in triple-transgenic mice is highly specific in I but not D and L cells in the terminal villi of the small intestine. The targeting of EECs only in terminal villi is due to the integration of a defective 2A separating peptide that, combined with low EEC intrinsic Vil1 expression, restricts our Vil1-2A-DD-Dre mouse line and the intersectional genetic approach described here only applicable for the investigation of mature EEC subpopulations.