Relationship between oxidative stress and erectile function

The aim of this study was to investigate markers of inflammation and oxidative stress in the corpus cavernosum (CC) and to compare levels of inflammatory markers recorded in CC to venous blood from the arm to examine the potential impact of inflammatory parameters on erectile function and endothelial dysfunction in vitro. Ninety-seven patients with no complaint of erectile dysfunction (ED) at inclusion were prospectively included and completed the Erectile Function domain of the IIEF questionnaire. Several parameters, including lipids, MPO-dependent oxidised LDL (Mox-LDL), IL-8, IL-18, were measured. After RNA extraction, the expression of eNOS was analysed. A paired t-test was used for comparisons between arm and CC blood results. A two-way ANOVA was used to estimate the effects of IL-18 and IL-8 on the IIEF score. Mean patient age was 59?±?14.5 years. IL-18, Mox-LDL, and Mox-LDL/ApoB levels were significantly increased in CC compared to arm blood. The IIEF score was correlated with IL-18 levels in the venous blood (R?=??0.31, p?=?.003) and in the CC (R?=??0.37, p?=?.004) and with IL-8 (R?=??0.31, p?=?.009 and R?=??0.28, respectively, p?=?.02). There was a significant effect with the IL-18 on IIEF potentiated by high serum IL-8 concentrations. IL-18 and Mox-LDL significantly decreased eNOS mRNA expression in human aortic endothelial cell line (HAEC). These preliminary results address the importance of inflammation in the CC and highlight a difference in marker concentrations between venous and CC blood. However, they do not show any difference in terms of clinical erectile score predictivity. Involvement of inflammatory cytokines isolated in CC in the genesis of ED requires further studies.     

Structural Maintenance of Chromosome (SMC) Proteins Link Microtubule Stability to Genome Integrity

Structural maintenance of chromosome (SMC) proteins are key organizers of chromosome architecture and are essential for genome integrity. They act by binding to chromatin and connecting distinct parts of chromosomes together. Interestingly, their potential role in providing connections between chromatin and the mitotic spindle has not been explored. Here, we show that yeast SMC proteins bind directly to microtubules and can provide a functional link between microtubules and DNA. We mapped the microtubule-binding region of Smc5 and generated a mutant with impaired microtubule binding activity. This mutant is viable in yeast but exhibited a cold-specific conditional lethality associated with mitotic arrest, aberrant spindle structures, and chromosome segregation defects. In an in vitro reconstitution assay, this Smc5 mutant also showed a compromised ability to protect microtubules from cold-induced depolymerization. Collectively, these findings demonstrate that SMC proteins can bind to and stabilize microtubules and that SMC-microtubule interactions are essential to establish a robust system to maintain genome integrity.     

The reproductive biology of the Rock Partridge Alectoris graeca saxatilis in the southern French Alps: first evidence of double-nesting behaviour

Capsule: Double-nesting occurs frequently in Rock Partridges Alectoris graeca living in the southern French Alps.

Aims: To investigate reproductive parameters of a Rock Partridge Alectoris graeca population.

Methods: The reproductive behaviour of 62 radio-tagged birds was monitored during the breeding seasons 2012–16, to record breeding phenology, clutch sizes, hatching success, nest survival and parental care.

Results: Double-nesting behaviour in the Rock Partridge was confirmed for the first time. Participation in incubation was similar for males and females (86% versus 70%). Clutch size was larger for nests incubated by males (11.0?±?1.6 eggs) than by females (9.5?±?1.2). Male nest survival rate (0.37) tended to be lower than female nest survival rate (0.62), although the difference was not significant. No significant difference was detected between male and female hatching success. Nest failures were caused by mammals taking the eggs (78%) or predation of the incubating parent (13%). Some circumstantial evidence suggests that occurrence of double-nesting behaviour could depend on previous winter and spring weather influencing the body condition of females. The reproductive biology of the Rock Partridge contrasts in some breeding traits with Red-legged Partridge and natural partridge hybrids, possibly due to climatic differences between habitats.

Conclusion: Confirmation of double-nesting in Rock Partridges indicates that climatic constraints inherent to its mountain environment do not act as an impediment to this behaviour. Variation in weather conditions between years could influence the annual occurrence of double-nesting.     

Interaction between cystatin-derived peptides and papain

The interaction between papain and synthetic peptides which tentatively mimic cystatin surfaces was investigated both enzymatically and structurally. Measurements of dissociation equilibrium constants for the interaction of papain with these peptides modified by successive deletions or substitutions demonstrated that the QVVAG segment, which is highly conserved throughout members of the cystatin superfamily, is essential for the interaction. The glycylcontaining (N-terminal) fragments and PW-containing (C-terminal) fragments were found to be of lesser importance, since each could be deleted without significantly modifying the interaction. These fragments improved the stability of the interacting QVVAG region, which appeared to be substrate-like in all peptides tested, as it was cleaved at the A-G bond upon peptide-papain interaction. Replacement of the A residue at the scissile bond of the QVVAG by a blocked cysteinyl residue reduced the rate of cleavage of the susceptible bond and therefore shifted the resulting peptide from a substrate to an inhibitor. Derivatization of this substituted peptide at its N- and C-terminal ends by fluoresceinyl groups resulted in a dramatic decrease in theK _i to 0.5 µM. This improvement in the inhibitory properties of the substituted and derivatized peptides was correlated with structural changes as analyzed by molecular dynamic calculations. The results were compared to those proposed for the mechanism of inhibition by natural inhibitors of the cystatin superfamily.     

ΔNp63 Is Essential for Epidermal Commitment of Embryonic Stem Cells

In vivo studies have demonstrated that p63 plays complex and pivotal roles in pluristratified squamous epithelial development, but its precise function and the nature of the isoform involved remain controversial. Here, we investigate the role of p63 in epithelial differentiation, using an in vitro ES cell model that mimics the early embryonic steps of epidermal development. We show that the ΔNp63 isoform is activated soon after treatment with BMP-4, a morphogen required to commit differentiating ES cells from a neuroectodermal to an ectodermal cell fate. ΔNp63 gene expression remains high during epithelial development. P63 loss of function drastically prevents ectodermal cells to commit to the K5/K14-positive stratified epithelial pathway while gain of function experiments show that ΔNp63 allows this commitment. Interestingly, other epithelial cell fates are not affected, allowing the production of K5/K18-positive epithelial cells. Therefore, our results demonstrate that ΔNp63 may be dispensable for some epithelial differentiation, but is necessary for the commitment of ES cells into K5/K14-positive squamous stratified epithelial cells.     

Use of ATP bioluminescence measurements for the estimation of biomass during biological humification

Summary The development of the microflora during the humification of grape pulp has been investigated by the determination of ATP using the bioluminescence technique. Several extraction methods were tested including the use of dimethylsulphoxide, trichloroacetic acid, grinding and ultrasonification. Dimethylsulphoxide and ultrasonification for 15 sec appeared to be the most effective. The ATP extract was stabilized when it was mixed with 0.75 mM glycine, 4.4 mM Mg-EDTA, pH 7.5 and frozen. The relative error of the ATP assay by bioluminescence did not exceed 6.5%. This method allowed us to show that at least five distinct reproducible microbial phases exist during grape pulp humification. These results show that the microbial biomass changes noticeably and at distinct times during composting.