Controversy and consensus on the management of elevated sperm DNA fragmentation in male infertility: A global survey, current guidelines, and expert recommendations

Purpose Sperm DNA fragmentation (SDF) has been associated with male infertility and poor outcomes of assisted reproductive technology (ART). The purpose of this study was to investigate global practices related to the management of elevated SDF in infertile men, summarize the relevant professional society recommendations, and provide expert recommendations for managing this condition. Materials and Methods An online global survey on clinical practices related to SDF was disseminated to reproductive clinicians, according to the CHERRIES checklist criteria. Management protocols for various conditions associated with SDF were captured and compared to the relevant recommendations in professional society guidelines and the appropriate available evidence. Expert recommendations and consensus on the management of infertile men with elevated SDF were then formulated and adapted using the Delphi method. Results A total of 436 experts from 55 different countries submitted responses. As an initial approach, 79.1% of reproductive experts recommend lifestyle modifications for infertile men with elevated SDF, and 76.9% prescribe empiric antioxidants. Regarding antioxidant duration, 39.3% recommend 4–6 months and 38.1% recommend 3 months. For men with unexplained or idiopathic infertility, and couples experiencing recurrent miscarriages associated with elevated SDF, most respondents refer to ART 6 months after failure of conservative and empiric medical management. Infertile men with clinical varicocele, normal conventional semen parameters, and elevated SDF are offered varicocele repair immediately after diagnosis by 31.4%, and after failure of antioxidants and conservative measures by 40.9%. Sperm selection techniques and testicular sperm extraction are also management options for couples undergoing ART. For most questions, heterogenous practices were demonstrated. Conclusions This paper presents the results of a large global survey on the management of infertile men with elevated SDF and reveals a lack of consensus among clinicians. Furthermore, it demonstrates the scarcity of professional society guidelines in this regard and attempts to highlight the relevant evidence. Expert recommendations are proposed to help guide clinicians

Mechanism of Action of Secreted Newt Anterior Gradient Protein

<div><p>Anterior gradient (AG) proteins have a thioredoxin fold and are targeted to the secretory pathway where they may act in the ER, as well as after secretion into the extracellular space. A newt member of the family (nAG) was previously identified as interacting with the GPI-anchored salamander-specific three-finger protein called Prod1. Expression of nAG has been implicated in the nerve dependence of limb regeneration in salamanders, and nAG acted as a growth factor for cultured newt limb blastemal (progenitor) cells, but the mechanism of action was not understood. Here we show that addition of a peptide antibody to Prod1 specifically inhibit the proliferation of blastema cells, suggesting that Prod1 acts as a cell surface receptor for secreted nAG, leading to S phase entry. Mutation of the single cysteine residue in the canonical active site of nAG to alanine or serine leads to protein degradation, but addition of residues at the C terminus stabilises the secreted protein. The mutation of the cysteine residue led to no detectable activity on S phase entry in cultured newt limb blastemal cells. In addition, our phylogenetic analyses have identified a new Caudata AG protein called AG4. A comparison of the AG proteins in a cell culture assay indicates that nAG secretion is significantly higher than AGR2 or AG4, suggesting that this property may vary in different members of the family.</p></div

Etude de non-linearites en hydrodynamique a surface libre

SIGLECNRS AR 12193 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Expression of nAG proteins with C terminal extensions.

<p>(A) Wild-type and mutant nAG proteins, with or without (untagged) additional residues at the C terminus, were expressed in Cos7 cells and the conditioned medium was analysed as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0154176#pone.0154176.g002" target="_blank">Fig 2</a>. Note that the myc-tagged samples were run on a separate gel to the other samples, and the four lanes were joined to the right hand side. GFP refers to control GFP-transfected cells. (B) The yield of nAG proteins in the medium was quantitated by analysis of western blots for three independent transfections. Note that the largest yield for each of the three proteins is obtained with the myc+25 extension.</p

Mutation of Cys72 leads to loss of activity.

<p>Cos7 cells were transfected with constructs expressing wild-type (WT), C72A, or C72Seither without a tag (untagged), with a myc-tag plus (myc + 25) or myc-tag minus (myc-tag without 25 aa). The conditioned media were analysed by western blotting and equivalent amounts of protein were added to blastemal cells growing in microwells. The data are given for the number (n) of microwells from 3 (in case of C72S) or 4 (other proteins) independent preparations of blastemal cells, normalised to the value for GFP.</p

Differential secretion of AG family members by cultured cells.

<p>Differential secretion of AG family members by cultured cells.</p

Antibody inhibition of nAG-induced S phase entry.

<p>Newt limb blastemal cells were cultured in microwells as described, and exposed to either conditioned medium from Cos7 cells transfected with control RFP plasmid (1–3), or nAG plasmid (4–7). Control rabbit IgG or affinity-purified rabbit IgG to Prod1 was added to the wells as follows:(1) control medium (2) control rabbit antibody, 20 μg/mL (3) anti Prod1, 20 μg/mL (4) nAG-containing medium, (5) control rabbit antibody, 20 μg/mL (6) anti Prod1, 10 μg/mL (7) anti Prod1, 20 μg/mL. Note the inhibition of nAG activity by anti Prod1 (* P<0.5) but not by control. Data from three independent transfections each normalised to the value for the RFP control, expressed as mean ± SD. The data were analysed by One-way Analysis of Variance (ANOVA) followed by Tukey’s multiple comparison test.</p

Representative phylogenetic tree highlighting the species distribution of selected anterior gradient genes.

<p>For clarity only relevant support values are shown. Note that proteins belonging to the AG4 cluster have, so far, only been found in salamanders while the nAG and XAG2 grouping contains both salamander and anuran sequences. The tree was calculated with MrBayes 3.1 using likelihood model parameters: nst = 6; rates = invgamma. The calculation was run for 10 million generations, sampling every 500 generations; the initial 5,000 trees were discarded. An equivalent clustering of sequences was obtained using a maximum-likelihood approach as implemented in Phyml3 using the LG+G+I model and 1000 bootstrap replicates.</p

Fermi establishes classical novae as a distinct class of gamma-ray sources

A classical nova results from runaway thermonuclear explosions on the surface of a white dwarf that accretes matter from a low-mass main-sequence stellar companion. In 2012 and 2013, three novae were detected in γ rays and stood in contrast to the first γ-ray-detected nova V407 Cygni 2010, which belongs to a rare class of symbiotic binary systems. Despite likely differences in the compositions and masses of their white dwarf progenitors, the three classical novae are similarly characterized as soft-spectrum transient γ-ray sources detected over 2- to 3-week durations. The γ-ray detections point to unexpected high-energy particle acceleration processes linked to the mass ejection from thermonuclear explosions in an unanticipated class of Galactic γ-ray sources