Tex19.1 inhibits the N-end rule pathway and maintains acetylated SMC3 cohesin and sister chromatid cohesion in oocytes.

Age-dependent oocyte aneuploidy, a major cause of Down syndrome, is associated with declining sister chromatid cohesion in postnatal oocytes. Here we show that cohesion in postnatal mouse oocytes is regulated by Tex19.1. We show Tex19.1-/- oocytes have defects maintaining chiasmata, missegregate their chromosomes during meiosis, and transmit aneuploidies to the next generation. Furthermore, we show that mouse Tex19.1 inhibits N-end rule protein degradation mediated by its interacting partner UBR2, and that Ubr2 itself has a previously undescribed role in negatively regulating the acetylated SMC3 subpopulation of cohesin in mitotic somatic cells. Lastly, we show that acetylated SMC3 is associated with meiotic chromosome axes in mouse oocytes, and that this population of cohesin is specifically depleted in the absence of Tex19.1. These findings indicate that Tex19.1 regulates UBR protein activity to maintain acetylated SMC3 and sister chromatid cohesion in postnatal oocytes and prevent aneuploidy from arising in the female germline.

HSP70-binding protein HSPBP1 regulates chaperone expression at a posttranslational level and is essential for spermatogenesis.

Molecular chaperones play key roles during growth, development, and stress survival. The ability to induce chaperone expression enables cells to cope with the accumulation of nonnative proteins under stress and complete developmental processes with an increased requirement for chaperone assistance. Here we generate and analyze transgenic mice that lack the cochaperone HSPBP1, a nucleotide-exchange factor of HSP70 proteins and inhibitor of chaperone-assisted protein degradation. Male HSPBP1(-/-) mice are sterile because of impaired meiosis and massive apoptosis of spermatocytes. HSPBP1 deficiency in testes strongly reduces the expression of the inducible, antiapoptotic HSP70 family members HSPA1L and HSPA2, the latter of which is essential for synaptonemal complex disassembly during meiosis. We demonstrate that HSPBP1 affects chaperone expression at a posttranslational level by inhibiting the ubiquitylation and proteasomal degradation of inducible HSP70 proteins. We further provide evidence that the cochaperone BAG2 contributes to HSP70 stabilization in tissues other than testes. Our findings reveal that chaperone expression is determined not only by regulated transcription, but also by controlled degradation, with degradation-inhibiting cochaperones exerting essential prosurvival functions.

The genome-defence gene Tex19.1 suppresses LINE-1 retrotransposons in the placenta and prevents intra-uterine growth retardation in mice.

DNA methylation plays an important role in suppressing retrotransposon activity in mammalian genomes, yet there are stages of mammalian development where global hypomethylation puts the genome at risk of retrotransposition-mediated genetic instability. Hypomethylated primordial germ cells appear to limit this risk by expressing a cohort of retrotransposon-suppressing genome-defence genes whose silencing depends on promoter DNA methylation. Here, we investigate whether similar mechanisms operate in hypomethylated trophectoderm-derived components of the mammalian placenta to couple expression of genome-defence genes to the potential for retrotransposon activity. We show that the hypomethylated state of the mouse placenta results in activation of only one of the hypomethylation-sensitive germline genome-defence genes: Tex19.1. Tex19.1 appears to play an important role in placenta function as Tex19.1(-/-) mouse embryos exhibit intra-uterine growth retardation and have small placentas due to a reduction in the number of spongiotrophoblast, glycogen trophoblast and sinusoidal trophoblast giant cells. Furthermore, we show that retrotransposon mRNAs are derepressed in Tex19.1(-/-) placentas and that protein encoded by the LINE-1 retrotransposon is upregulated in hypomethylated trophectoderm-derived cells that normally express Tex19.1. This study suggests that post-transcriptional genome-defence mechanisms are operating in the placenta to protect the hypomethylated cells in this tissue from retrotransposons and suggests that imbalances between retrotransposon activity and genome-defence mechanisms could contribute to placenta dysfunction and disease.

The tissue-specific Rep8/UBXD6 tethers p97 to the endoplasmic reticulum membrane for degradation of misfolded proteins.

The protein known as p97 or VCP in mammals and Cdc48 in yeast is a versatile ATPase complex involved in several biological functions including membrane fusion, protein folding, and activation of membrane-bound transcription factors. In addition, p97 plays a central role in degradation of misfolded secretory proteins via the ER-associated degradation pathway. This functional diversity of p97 depends on its association with various cofactors, and to further our understanding of p97 function it is important that these cofactors are identified and analyzed. Here, we isolate and characterize the human protein named Rep8 or Ubxd6 as a new cofactor of p97. Mouse Rep8 is highly tissue-specific and abundant in gonads. In testes, Rep8 is expressed in post-meiotic round spermatids, whereas in ovaries Rep8 is expressed in granulosa cells. Rep8 associates directly with p97 via its UBX domain. We show that Rep8 is a transmembrane protein that localizes to the ER membrane with its UBX domain facing the cytoplasm. Knock-down of Rep8 expression in human cells leads to a decreased association of p97 with the ER membrane and concomitantly a retarded degradation of misfolded ER-derived proteasome substrates. Thus, Rep8 tethers p97 to the ER membrane for efficient ER-associated degradation.

Cancer incidence in four pacific countries: Tonga, Fiji Islands, Cook Islands and Niue.

BACKGROUND: We have established and/or upgraded cancer registries in four Pacific countries, a region where few cancer registries exist. We report age-standardised cancer incidence in Tonga (2000-2005), Fiji (2002-2005), Cook Islands (2000-2005) and Niue (2000-2005), and in Pacific people in New Zealand (2000-2005). METHODS: In each country we identified incident cancer cases by reviewing hospital discharge, death registration, cancer registration records, and pathology reports. The primary site and morphology data were coded using ICD-0, and age-standardised incidence rates were calculated. RESULTS: Age-standardised cancer incidence rates for Pacific people in New Zealand (315 per 100,000 person-years in females, 379 in males) were similar to those for New Zealand overall (322 in females, 404 in males); incidence rates were lower in the Pacific, with rates of 195 and 151 per 100,000 person-years for females and males respectively in Tonga, 231 and 126 in Fiji, 165 and 142 in the Cook Islands, and 228 and 131 in Niue. However, some specific cancers were elevated in the Pacific including cervical cancer (16 per 100,000 in Tonga, 51 in Fiji, 17 in Cook Islands, and 26 in Niue compared with 10 in Pacific people in New Zealand, and 8 in New Zealand overall), liver cancer (rates of 8, 5, 19, 0, 7, and 2 respectively) and uterine cancer (rates of 24, 18, 47, 19 and 12 respectively). CONCLUSIONS: Cancer incidence in the Pacific is lower than for Pacific people living in New Zealand. Environmental rather than genetic factors are most likely to explain these patterns, and cancer incidence in the Pacific is likely to increase to rates similar to those in New Zealand as the region becomes more 'westernised' The high rates of cervical cancer and liver cancer in the Pacific indicate an important role of

A comprehensive hand hygiene approach to reducing MRSA health care-associated infections.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) infections are the most common health care-associated infections (HAI) in the acute care setting. The major mode of transmission from patient to patient is through bedside care providers via contaminated hands. After individual projects within Novant Health proved to be ineffective, with any gains in hand hygiene compliance being short-lived, a program was implemented to address unsatisfactory hand hygiene compliance rates. Published studies have associated improvements in hand hygiene compliance with decreases in HAIs. METHODS: A comprehensive systemwide program was developed with major program support from the education, marketing, clinical improvement, and clinical care departments. The key drivers of the program were the use of alcohol-based hand sanitizer and the system's dedication of resources to collect and report the compliance data. Monthly compliance rates were collected by two dedicated compliance monitors, and the results were shared across the system. In addition, MRSA HAI rates were followed for all the acute care facilities. RESULTS: Hand hygiene compliance rates increased from a baseline compliance of 49% to 98% for December 2008, with sustained rates greater than 90% since November 2006. More importantly, MRSA rates decreased from 0.52 HAIs per 1,000 patient days in 2005 to 0.24 HAIs per 1,000 patient days by year-end 2008. DISCUSSION: Understanding hand hygiene compliance is a simple matter of observing caregiver behavior during each hand hygiene opportunity and recording the actions taken. The improvements in hand hygiene compliance translated into a real decrease in the number of hospital-acquired MRSA infections.

Germ cell sex determination in mammals.

One of the major decisions that germ cells make during their development is whether to differentiate into oocytes or sperm. In mice, the germ cells' decision to develop as male or female depends on sex-determining signalling molecules in the embryonic gonadal environment rather than the sex chromosome constitution of the germ cells themselves. In response to these sex-determining cues, germ cells in female embryos initiate oogenesis and enter meiosis, whereas germ cells in male embryos initiate spermatogenesis and inhibit meiosis until after birth. However, it is not clear whether the signalling molecules that mediate germ cell sex determination act in the developing testis or the developing ovary, or what these signalling molecules might be. Here, we review the evidence for the existence of meiosis-inducing and meiosis-preventing substances in the developing gonad, and more recent studies aimed at identifying these molecules in mice. In addition, we discuss the possibility that some of the reported effects of these factors on germ cell development may be indirect consequences of impairing sexual differentiation of gonadal somatic cells or germ cell survival. Understanding the molecular mechanisms of germ cell sex determination may provide candidate genes for susceptibility to germ cell tumours and infertility in humans.

Sdmg1 is a component of secretory granules in mouse secretory exocrine tissues.

Sdmg1 is a conserved eukaryotic transmembrane protein that is mainly expressed in the gonads where it may have a role in mediating signaling between somatic cells and germ cells. In this study we demonstrate that secretory exocrine cells in the pancreas, salivary gland, and mammary gland also express Sdmg1. Furthermore, we show that Sdmg1 expression is up-regulated during pancreas development when regulated secretory granules start to appear, and that Sdmg1 colocalizes with secretory granule markers in adult pancreatic acinar cells. In addition, we show that Sdmg1 co-purifies with secretory granules during subcellular fractionation of the pancreas and that Sdmg1 and the secretory granule marker Vamp2 are localized to distinct subdomains in the secretory granule membrane. These data suggest that Sdmg1 is a component of regulated secretory granules in exocrine secretory cells and that the developmental regulation of Sdmg1 expression is related to a role for Sdmg1 in post-Golgi membrane trafficking.

Sdmg1 is a conserved transmembrane protein associated with germ cell sex determination and germline-soma interactions in mice.

In mammals, the supporting cell lineage in an embryonic gonad communicates the sex-determining decision to various sexually dimorphic cell types in the developing embryo, including the germ cells. However, the molecular nature of the sex-determining signals that pass from the supporting cells to the germ cells is not well understood. We have identified a conserved transmembrane protein, Sdmg1, owing to its male-specific expression in mouse embryonic gonads. Sdmg1 is expressed in the Sertoli cells of embryonic testes from 12.5 dpc, and in granulosa cells of growing follicles in adult ovaries. In Sertoli cells, Sdmg1 is localised to endosomes, and knock-down of Sdmg1 in Sertoli cell lines causes mis-localisation of the secretory SNARE Stx2 and defects in membrane trafficking. Upregulation of Sdmg1 appears to be part of a larger programme of changes to membrane trafficking pathways in embryonic Sertoli cells, and perturbing secretion in male embryonic gonads in organ culture causes male-to-female germ cell sex reversal. These data suggest that changes that occur in the cell biology of embryonic Sertoli cells may facilitate the communication of male sex-determining decisions to the germ cells during embryonic development.

Reduction in anticoagulation-related adverse drug events using a trigger-based methodology.

BACKGROUND: An initiative was undertaken by Novant Health System to address warfarin-related adverse drug events (ADEs) using lab-based patient-specific International Normalized Ratio (INR) triggers and pharmacy-based patient-specific Vitamin K triggers. The goal was to reduce ADEs related to the use of warfarin in both the inpatient and outpatient settings. Process improvements and medication management protocols were developed for patients managed with warfarin anticoagulation. METHODS: During each month's seven-day sampling period, the hospital information system generated the lab and pharmacy triggers, and the clinical pharmacists used these patient-specific triggers to identify the patient charts for review. All triggered charts were reviewed. Preliminary harm classification based on the National Coordinating Council for Medication Error Reporting and Prevention (NCC MERP) index was assigned by the clinical pharmacists and recorded for each patient. RESULTS: The system achieved reductions in ADEs related to warfarin administration on an inpatient management (45%) and outpatient management (52%) basis. DISCUSSION: Although based on inpatient facility-generated triggers, the initiative also served as a reasonable outpatient model, with improvements seen in the outpatient physician intervention groups.