Non-genetic inheritance, fertility and assisted reproductive technologies

The concept of non-genetic inheritance is gaining considerable attention in the assisted reproductive technology (ART) community due to the reported differences between children born from ART and those that are conceived naturally. It has been demonstrated that children conceived via ART have differences in fetal growth, birth weight, congenital abnormalities, cardiometabolic parameters, glucose homeostasis as well as changes to body composition compared to children conceived naturally. Although these changes may have a parental contribution and may be influenced by the pathology of infertility there is concern that the technologies themselves may play a role. In support of this, is emerging evidence that aspects of ART technology such as culture media formulation and insemination method can alter offspring phenotype. In addition it is also documented that exposure to environmental factors, such as toxins can impact on offspring gametogenesis such that these perturbations persist through generations. With the increasing use of ART and the development of new technologies it is vital that we understand whether ART can effect non-genetic inheritance so that we can optimise technology and prevent abnormal programming and its impact on all aspects of offspring health including fertility and a possible transmission to subsequent generations.Deirdre Zander-Fox, Nicole O McPherson, Michelle Lan

The transcriptional repressor protein NsrR senses nitric oxide directly via a [2Fe-2S] cluster

The regulatory protein NsrR, a member of the Rrf2 family of transcription repressors, is specifically dedicated to sensing nitric oxide (NO) in a variety of pathogenic and non-pathogenic bacteria. It has been proposed that NO directly modulates NsrR activity by interacting with a predicted [Fe-S] cluster in the NsrR protein, but no experimental evidence has been published to support this hypothesis. Here we report the purification of NsrR from the obligate aerobe Streptomyces coelicolor. We demonstrate using UV-visible, near UV CD and EPR spectroscopy that the protein contains an NO-sensitive [2Fe-2S] cluster when purified from E. coli. Upon exposure of NsrR to NO, the cluster is nitrosylated, which results in the loss of DNA binding activity as detected by bandshift assays. Removal of the [2Fe-2S] cluster to generate apo-NsrR also resulted in loss of DNA binding activity. This is the first demonstration that NsrR contains an NO-sensitive [2Fe-2S] cluster that is required for DNA binding activity

Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for the Identification of Clinically Relevant Bacteria

Background: Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) allows rapid and reliable identification of microorganisms, particularly clinically important pathogens. Methodology/Principal Findings: We compared the identification efficiency of MALDI-TOF MS with that of PhoenixH, APIH and 16S ribosomal DNA sequence analysis on 1,019 strains obtained from routine diagnostics. Further, we determined the agreement of MALDI-TOF MS identifications as compared to 16S gene sequencing for additional 545 strains belonging to species of Enterococcus, Gardnerella, Staphylococcus, and Streptococcus. For 94.7 % of the isolates MALDI-TOF MS results were identical with those obtained with conventional systems. 16S sequencing confirmed MALDI-TOF MS identification in 63 % of the discordant results. Agreement of identification of Gardnerella, Enterococcus, Streptococcus and Staphylococcus species between MALDI-TOF MS and traditional method was high (Crohn’s kappa values: 0.9 to 0.93). Conclusions/Significance: MALDI-TOF MS represents a rapid, reliable and cost-effective identification technique for clinically relevant bacteria

Rectal Transmission of Transmitted/Founder HIV-1 Is Efficiently Prevented by Topical 1% Tenofovir in BLT Humanized Mice

Rectal microbicides are being developed to prevent new HIV infections in both men and women. We focused our in vivo preclinical efficacy study on rectally-applied tenofovir. BLT humanized mice (n = 43) were rectally inoculated with either the primary isolate HIV-1(JRCSF) or the MSM-derived transmitted/founder (T/F) virus HIV-1(THRO) within 30 minutes following treatment with topical 1% tenofovir or vehicle. Under our experimental conditions, in the absence of drug treatment we observed 50% and 60% rectal transmission by HIV-1(JRCSF) and HIV-1(THRO), respectively. Topical tenofovir reduced rectal transmission to 8% (1/12; log rank p = 0.03) for HIV-1(JRCSF) and 0% (0/6; log rank p = 0.02) for HIV-1(THRO). This is the first demonstration that any human T/F HIV-1 rectally infects humanized mice and that transmission of the T/F virus can be efficiently blocked by rectally applied 1% tenofovir. These results obtained in BLT mice, along with recent ex vivo, Phase 1 trial and non-human primate reports, provide a critically important step forward in the development of tenofovir-based rectal microbicides

Spontaneous Eosinophilic Nasal Inflammation in a Genetically-Mutant Mouse: Comparative Study with an Allergic Inflammation Model

Background: Eosinophilic inflammation is a hallmark of chronic rhinosinusitis with nasal polyps. To model this disease process experimentally, nasal sensitization of mice with ovalbumin or aspergillus has been described. Here, we describe a genetically mutant mouse that develops robust spontaneous nasal eosinophilic inflammation. These mice lack the enzyme SHP-1 that down-regulates the IL-4Ra/stat6 signaling pathway. We compared nasal inflammation and inflammatory mediators in SHP-1 deficient mice (mev) and an ovalbumin-induced nasal allergy model. Methods: A novel technique of trans-pharyngeal nasal lavage was developed to obtain samples of inflammatory cells from the nasal passages of allergic and mev mice. Total and differential cell counts were performed on cytospin preparations. Expression of tissue mRNA for IL-4, IL-13, and mouse beta-defensin-1 (MBD-1) was determined by quantitative PCR. Eotaxin in the lavage fluid was assessed by ELISA. Results: Allergic and mev mice had increased total cells and eosinophils compared with controls. Expression of IL-4 was similarly increased in both allergic and mev mice, but expression of IL-13 and eotaxin was significantly greater in the allergic mice than mev mice. Eotaxin was significantly up-regulated in both allergic rhinitis and mev mice. In both models of eosinophilic inflammation, down-regulation of the innate immune marker MBD-1 was observed. Conclusions: The mev mice display spontaneous chronic nasal eosinophilic inflammation with potential utility for chroni

Postprandial Oxidative Stress in Exercise Trained and Sedentary Cigarette Smokers

Cigarette smokers experience an exaggerated triglyceride (TAG) and oxidative stress response to high fat feeding. Exercise training may serve to attenuate the rise in these variables, by improving TAG clearance and antioxidant defense. We compared blood TAG, antioxidant capacity, and oxidative stress biomarkers in exercise trained (>2 hrs per wk) and untrained smokers matched for age, in response to a high fat test meal. We report here that low volume exercise training can attenuate postprandial lipid peroxidation, but has little impact on blood TAG and other markers of oxidative stress. Higher volumes of exercise may be needed to allow for clinically meaningful adaptations in postprandial lipemia and oxidative stress