ZFP281 controls transcriptional and epigenetic changes promoting mouse pluripotent state transitions via DNMT3 and TET1

The progression from naive through formative to primed in vitro pluripotent stem cell states recapitulates epiblast development in vivo during the peri-implantation period of mouse embryo development. Activation of the de novo DNA methyltransferases and reorganization of transcriptional and epigenetic landscapes are key events that occur during these pluripotent state transitions. However, the upstream regulators that coordinate these events are relatively underexplored. Here, using Zfp281 knockout mouse and degron knockin cell models, we identify the direct transcriptional activation of Dnmt3a/3b by ZFP281 in pluripotent stem cells. Chromatin co-occupancy of ZFP281 and DNA hydroxylase TET1, which is dependent on the formation of R-loops in ZFP281-targeted gene promoters, undergoes a "high-low-high" bimodal pattern regulating dynamic DNA methylation and gene expression during the naive-formative-primed transitions. ZFP281 also safeguards DNA methylation in maintaining primed pluripotency. Our study demonstrates a previously unappreciated role for ZFP281 in coordinating DNMT3A/3B and TET1 functions to promote pluripotent state transitions.

ZFP281 coordinates DNMT3 and TET1 for transcriptional and epigenetic control in pluripotent state transitions

The progression from naive through formative to primed in vitro pluripotent stem cell states recapitulates the development of the epiblast in vivo during the peri-implantation period of mammalian development. Activation of the de novo DNA methyltransferases and reorganization of transcriptional and epigenetic landscapes are key events occurring during these pluripotent state transitions. However, the upstream regulators that coordinate these events are relatively underexplored. Here, using Zfp281 knockout mouse and degron knock-in cell models, we uncover the direct transcriptional activation of Dnmt3a/3b by ZFP281 in pluripotent stem cells. Chromatin co-occupancy of ZFP281 and DNA hydroxylase TET1, dependent on the formation of R loops in ZFP281-targeted gene promoters, undergoes a "high-low-high" bimodal pattern regulating dynamic DNA methylation and gene expression during the naïive-formative-primed transitions. ZFP281 also safeguards DNA methylation in maintaining primed pluripotency. Our study demonstrates a previously unappreciated role for ZFP281 in coordinating DNMT3A/3B and TET1 functions to promote pluripotent state transitions.

Relationship Between the OF Classification and Radiological Outcome of Osteoporotic Vertebral Fractures After Kyphoplasty

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The OF classification is a new classification for osteoporotic vertebral fractures. The aim of this study was to clarify the relationship between preoperative OF subgroups and the postoperative outcome after kyphoplasty in patients with such fractures.

METHODS

Patients who underwent kyphoplasty of a single osteoporotic vertebral fracture were included and divided into groups according to the OF subgroups. Pre- and postoperative plain radiographs were analyzed in regard to the restoration of vertebral body height and local kyphotic angle (LKA). Additionally, clinical data including pre- and postoperative Visual Analogue Scale pain scores was documented. The clinical and radiological results were compared pre- and postoperatively within groups and between groups.

RESULTS

A total of 156 patients from OF subgroups 2 to 4 were included (OF 2: n = 58; OF 3: n = 36; OF 4: n = 62). Patients from all groups experienced significant pain relief postoperatively (P < .001). Patients with OF 2 fractures showed a repositioning of the vertebral body height in the anterior and middle portions (both P < .001), but no significant improvement in LKA. For OF 3 and 4 fractures, there was a significant restoration of vertebral body height (P < .001 for both) and a significant improvement of LKA (P < .001 for both). The highest average restoration was noted in the OF 4 group.

CONCLUSIONS

A higher OF subgroup is related to a higher radiological benefit from kyphoplasty. This confirms that the OF classification is an appropriate tool for the preoperative assessment of osteoporotic fractures.

Influence of operative timing on the early post-operative radiological and clinical outcome after kyphoplasty

PURPOSE

To clarify the relationship between operative timing and the early post-operative radiological and clinical outcome after kyphoplasty.

METHODS

We conducted a retrospective cohort study including patients who underwent kyphoplasty of a single vertebra. Patients were divided into three groups (acute [< 2 weeks], subacute [2-6 weeks] or chronic [6-51 weeks]) based on the interval between fracture and surgery. The relative vertebral body height (VBH) and local kyphotic angle (LKA) of the fractured vertebra (measured on plain radiographs) as well as pain and use of analgesics were compared pre- and post-operatively (day 2) and between the groups.

RESULTS

A total of 230 patients (100 with acute, 91 with subacute and 39 with chronic fractures) with fractures from T4 to L5 were included. In all groups, there was a significant post-operative improvement in the anterior (8.9-12.9%) and middle (10.7-13.4%) VBH (all groups: p < 0.001), LKA (acute: 3.8°, p < 0.001; subacute: 4.3°, p < 0.001; chronic: 1.7°, p = 0.046) and pain. The use of analgesics significantly decreased post-operatively in the acute and subacute groups, but did not significantly change in the chronic group. Patients from acute (p = 0.042) and subacute (p = 0.027) groups showed significantly better post-operative correction of the LKA than the chronic group.

CONCLUSION

Kyphoplasty is effective for vertebral height restoration as well as pain relief for both acute, subacute and chronic fractures. However, the achievable correction of the fracture-related local kyphosis decreases significantly after 6 weeks. Therefore, we recommend making a final decision about conservative vs. operative treatment within 6 weeks to ensure better height restoration in surgically treated patients.

Single-Pass Albumin Dialysis in the Treatment of Children with Liver Failure

BACKGROUND AND AIMS

Acute and acute on chronic liver failure are life-threatening conditions, and bridging to transplantation is complicated by a paucity of suitable organs for children. While different modalities of extracorporeal liver support exist, their use in children is complicated by a large extracorporeal volume, and data on their use in children is limited. The aim of this analysis was to investigate the efficacy and safety of single-pass albumin dialysis (SPAD) in children with liver failure.

METHODS

Retrospective medical chart review of pediatric patients with liver failure treated with SPAD. The decrease in hepatic encephalopathy (HE) and the serum levels of bilirubin and ammonia were measured to determine efficacy. Adverse events were documented to assess safety.

RESULTS

Nineteen pediatric patients with a median age of 25.5 months and a median body weight of 11.9 kg were treated with SPAD between January 2011 and March 2018. Total bilirubin (p < 0.001) and ammonia (p = 0.02) significantly decreased after treatment with SPAD. As clinical outcome parameter, HE significantly improved (p = 0.001). Twelve patients were bridged successfully to liver transplantation. In all patients, 71 SPAD sessions were run. Clotting in the dialysis circuit was observed in 49% of all sessions. Heparin and citrate were used for anticoagulation and were significantly superior to dialysis without any anticoagulation (p= 0.03). Transfusion of packed blood cells (57%) and catecholamine therapy (49%) were frequently necessary.

CONCLUSIONS

Treatment with SPAD was effective in detoxification, as measured by significant improvement of HE and clearance from surrogate laboratory parameters.

Kinesin-2 and IFT-A act as a complex promoting nuclear localization of β-catenin during Wnt signalling

Wnt/Wg-signalling is critical signalling in all metazoans. Recent studies suggest that IFT-A proteins and Kinesin-2 modulate canonical Wnt/Wg-signalling independently of their ciliary role. Whether they function together in Wnt-signalling and their mechanistic role in the pathway remained unresolved. Here we demonstrate that Kinesin-2 and IFT-A proteins act as a complex during Drosophila Wg-signalling, affecting pathway activity in the same manner, interacting genetically and physically, and co-localizing with β-catenin, the mediator of Wnt/Wg-signalling on microtubules. Following pathway activation, Kinesin-2/IFT-A mutant cells exhibit high cytoplasmic β-catenin levels, yet fail to activate Wg-targets. In mutant tissues in both, Drosophila and mouse/MEFs, nuclear localization of β-catenin is markedly reduced. We demonstrate a conserved, motor-domain dependent function of the Kinesin-2/IFT-A complex in promoting nuclear translocation of β-catenin. We show that this is mediated by protecting β-catenin from a conserved cytoplasmic retention process, thus identifying a mechanism for Kinesin-2/IFT-A in Wnt-signalling that is independent of their ciliary role.

IFT-A proteins and Kinesin-2 modulate canonical Wnt/Wg-signalling independent of their ciliary role, but how is unclear. Here, the authors show that Kinesin-2 and IFT-A act as a complex to promote nuclear translocation of β-catenin in Drosophila and mouse MEF Wnt signalling independent of its ciliary role.

Reviving post-mortem diagnostics as a tool to increase porcine herd health and strengthen early detection of pig diseases - the PathoPig project 2014-2016

INTRODUCTION

Post-mortem diagnostics are an important tool for disease diagnosis and therefore early detection of (re-)emerging animal diseases and zoonoses as well as nationwide disease surveillance programs. To counteract the decline of porcine necropsies in Switzerland over the last ten years, the Federal Food Safety and Veterinary Office (FSVO) launched a national project in 2014 called PathoPig. Post-mortem examinations of pigs from herds with health problems were financially supported by the FSVO. During the first 3 years of the project, the number of pig necropsies increased by 195% (mean). An underlying cause of disease was identified in 74% of the cases. These findings resulted in specific recommendations by the attending veterinarians or by the Swiss Porcine Health Service. A follow-up survey revealed that herd health had improved in 90% of the farms implementing the recommendations.

Zfp281 is essential for mouse epiblast maturation through transcriptional and epigenetic control of Nodal signaling

Pluripotency is defined by a cell's potential to differentiate into any somatic cell type. How pluripotency is transited during embryo implantation, followed by cell lineage specification and establishment of the basic body plan, is poorly understood. Here we report the transcription factor Zfp281 functions in the exit from naive pluripotency occurring coincident with pre-to-post-implantation mouse embryonic development. By characterizing Zfp281 mutant phenotypes and identifying Zfp281 gene targets and protein partners in developing embryos and cultured pluripotent stem cells, we establish critical roles for Zfp281 in activating components of the Nodal signaling pathway and lineage-specific genes. Mechanistically, Zfp281 cooperates with histone acetylation and methylation complexes at target gene enhancers and promoters to exert transcriptional activation and repression, as well as epigenetic control of epiblast maturation leading up to anterior-posterior axis specification. Our study provides a comprehensive molecular model for understanding pluripotent state progressions in vivo during mammalian embryonic development.

Notochord morphogenesis in mice: Current understanding & open questions

The notochord is a structure common to all chordates, and the feature that the phylum Chordata has been named after. It is a rod-like mesodermal structure that runs the anterior-posterior length of the embryo, adjacent to the ventral neural tube. The notochord plays a critical role in embryonic tissue patterning, for example the dorsal-ventral patterning of the neural tube. The cells that will come to form the notochord are specified at gastrulation. Axial mesodermal cells arising at the anterior primitive streak migrate anteriorly as the precursors of the notochord and populate the notochordal plate. Yet, even though a lot of interest has centered on investigating the functional and structural roles of the notochord, we still have a very rudimentary understanding of notochord morphogenesis. The events driving the formation of the notochord are rapid, taking place over the period of approximately a day in mice. In this commentary, we provide an overview of our current understanding of mouse notochord morphogenesis, from the initial specification of axial mesendodermal cells at the primitive streak, the emergence of these cells at the midline on the surface of the embryo, to their submergence and organization of the stereotypically positioned notochord. We will also discuss some key open questions. Developmental Dynamics 245:547-557, 2016. © 2016 Wiley Periodicals, Inc.

Components of Intraflagellar Transport Complex A Function Independently of the Cilium to Regulate Canonical Wnt Signaling in Drosophila

The development of multicellular organisms requires the precisely coordinated regulation of an evolutionarily conserved group of signaling pathways. Temporal and spatial control of these signaling cascades is achieved through networks of regulatory proteins, segregation of pathway components in specific subcellular compartments, or both. In vertebrates, dysregulation of primary cilia function has been strongly linked to developmental signaling defects, yet it remains unclear whether cilia sequester pathway components to regulate their activation or cilia-associated proteins directly modulate developmental signaling events. To elucidate this question, we conducted an RNAi-based screen in Drosophila non-ciliated cells to test for cilium-independent loss-of-function phenotypes of ciliary proteins in developmental signaling pathways. Our results show no effect on Hedgehog signaling. In contrast, our screen identified several cilia-associated proteins as functioning in canonical Wnt signaling. Further characterization of specific components of Intraflagellar Transport complex A uncovered a cilia-independent function in potentiating Wnt signals by promoting β-catenin/Armadillo activity.

The clathrin adaptor AP-1 complex and Arf1 regulate planar cell polarity in vivo

A key step in generating planar cell polarity (PCP) is the formation of restricted junctional domains containing Frizzled/Dishevelled/Diego (Fz/Dsh/Dgo) or Van Gogh/Prickle (Vang/Pk) complexes within the same cell, stabilized via Flamingo (Fmi) across cell membranes. Although models have been proposed for how these complexes acquire and maintain their polarized localization, the machinery involved in moving core PCP proteins around cells remains unknown. We describe the AP-1 adaptor complex and Arf1 as major regulators of PCP protein trafficking in vivo. AP-1 and Arf1 disruption affects the accumulation of Fz/Fmi and Vang/Fmi complexes in the proximo-distal axis, producing severe PCP phenotypes. Using novel tools, we demonstrate a direct and specific Arf1 involvement in Fz trafficking in vivo. Moreover, we uncover a conserved Arf1 PCP function in vertebrates. Our data support a model whereby the trafficking machinery plays an important part during PCP establishment, promoting formation of polarized PCP-core complexes in vivo.

Cellular cross talk in the small intestinal mucosa: postnatal lymphocytic immigration elicits a specific epithelial transcriptional response

During the early postnatal period lymphocytes migrate into the mouse small intestine. Migrating infiltrative lymphocytes have the potential to affect the epithelial cells via secreted cytokines. Such cross talk can result in the elicitation of an epithelial transcriptional response. Knowledge about such physiological cross talk between the immune system and the epithelium in the postnatal small intestinal mucosa is lacking. We have investigated the transcriptome changes occurring in the postnatal mouse small intestine using DNA microarray technology, immunocytochemistry, and quantitative real-time RT-PCR analysis. The DNA microarray data were analyzed bioinformatically by using a combination of projections to latent structures analysis and functional annotation analysis. The results show that infiltrating lymphocytes appear in the mouse small intestine in the late postweaning period and give rise to distinct changes in the epithelial transcriptome. Of particular interest is the expression of three genes encoding a mucin (Muc4), a mucinlike protein (16000D21Rik), and ATP citrate lyase (Acly). All three genes were shown to be expressed by the epithelium and to be upregulated in response to lymphocytic migration into the small intestinal mucosa.

Intra- and intertester reliability and criterion validity of the parallelogram and universal goniometers for measuring maximum active knee flexion and extension of patients with knee restrictions

OBJECTIVE

To examine the intra- and intertester reliability of the universal goniometer (UG) and parallelogram goniometer (PG), and to assess the criterion validity of the same instruments on subjects with knee restrictions.

DESIGN

Reliability and validation study.

SETTING

Radiology department at university hospital.

PARTICIPANTS

Sixty subjects (34 men, 26 women; mean age, 52yr) with various knee restrictions.

INTERVENTIONS

Sixteen goniometric measurements were collected per patient by 2 physical therapists. Subjects were evaluated in knee flexion and knee extension positions. To serve as a gold standard, radiographs were taken in both positions.

MAIN OUTCOME MEASURES

Active knee flexion and knee extension on 2 goniometers, radiographs. Maximum active range of motion (AROM).

RESULTS

The UG intratester reliability (intraclass correlation coefficients [ICCs]) was .997 in flexion and .972 to .985 in extension. The results were also high with the PG (ICC =.996,.953-.955) for flexion and extension, respectively. The intertester reliability was high for flexion (ICC =.977-.982) and for extension (ICC =.893-.926) when using the UG. For the PG, ICC results ranged from .959 to .970 for flexion and from .856 to .898 for extension. Criterion validity (r) varied from .975 to .987 for flexion and from .390 to .442 for extension with the UG, and from .976 to .985 for flexion and .423 to .514 for extension with the PG.

CONCLUSION

Intra- and intertester reliability were high for both goniometers. The results for the criterion validity varied. Our study also revealed that it is preferable to use goniometry rather than visual estimations when measuring AROM. It is recommended that the same therapist take all the measurements when assessing AROM for UG and PG goniometric measurements on patients with knee restrictions.

Economical microscope configuration for direct mycological examination with fluorescence in dermatology

BACKGROUND

The use of fluorochromes such as Blankophor or Calcofluor allows to detect immediately and without ambiguity fungal elements in dermatological preparations. Whereas fluorescence microscopy is widely practised in clinical laboratories, it is not generally used in private practice because of the high price of a epifluorescence microscope.

OBJECTIVE

To propose an economical microscope configuration to visualize fungal elements using fluorescence.

METHODS

The preparations were examined with a standard microscope for routine observations, equipped with only two supplementary filters.

RESULTS

Because the fungal elements produce a particularly bright fluorescence, a 25-watt halogen light is sufficient to visualize them in dermatological preparations:

CONCLUSIONS

The proposed microscope configuration for direct mycological examination is particularly economical since equipment for epifluorescence and a vapour mercury lamp are not necessary.

An audit of out-of-hours advice services provided by hospice staff

For those giving and receiving health care there will always be problems and queries which occur outside of normal office hours. Palliative care is no exception. It was found that Queenscourt Hospice in Southport was being used as an accessible point of contact for specialist palliative care advice by patients, relatives and health professionals. In response, an audit was undertaken to monitor the frequency and substance of the many drop-in visits and telephone calls to the hospice. The results showed that almost half of the calls/visits received are outside office hours. This article describes the nature of the calls and the advice offered by the staff taking the call. As the majority of the 'out-of-hours' calls/visits were taken by nursing staff, it was necessary for them to draw on their specialist palliative care knowledge and communication skills to make an assessment of how best to deal with each situation. As a result of the audit, several organizational and educational initiatives have been developed to further improve the service offered.

Intratester and intertester reliability and criterion validity of the parallelogram and universal goniometers for active knee flexion in healthy subjects

BACKGROUND AND PURPOSE

A new parallelogram goniometer was designed by the Rehabilitation Centre of the Royal Ottawa Health Care Group in 1983. The advantage of using such a goniometer is that the clinician is not required to estimate the joint axis of rotation when taking a measurement. The parallelogram goniometer has obtained a good intratester and intertester reliability when measuring active range of motion of hip abduction on eight individuals with hip pathologies. However, the validity of the parallelogram goniometer has not been examined. The purposes of this study were to examine the intratester and intertester reliability and the criterion validity of the parallelogram and universal goniometers for active knee flexion on healthy individuals.

SUBJECTS

Sixty healthy university students (44 females and 16 males; mean age of 20.6 yrs.) participated to this study.

METHODS

Measurements with the universal and parallelogram goniometers were taken in two different positions, the smaller and larger angles of active knee flexion. All measurements were taken by two trained testers. A radiograph was taken in both positions to serve as the 'gold standard'. The sequence of the measurements and radiographs were randomly selected. The intra and intertester reliability of both goniometers were established by calculating the intraclass correlation coefficients (ICCs) using the repeated-measures ANOVA. The criterion validity was examined by calculating Pearson product-moment correlation coefficients (tau) between each goniometric and radiologic measurements. A 0.05 level of significance was chosen for each statistical test.

RESULTS

Intratester reliability ranged from good to excellent for the small angles (ICC = 0.85 and 0.87) and the large angles (ICC = 0.91 and 0.96) when using the parallelogram goniometer. Intertester reliability was fair for the small angles of flexion (ICC = 0.43 to 0.52) and good to excellent for the large angles of flexion (ICC = 0.82 to 0.88). The parallelogram goniometer was found to have greater validity when measuring the large angles of knee flexion (r = 0.73 and 0.77) compared to the small angles of knee flexion (r = 0.33 and 0.41). Similar results of reliability and validity were obtained with the universal goniometer.

CONCLUSION

The results of this study have clinical importance. The use of the parallelogram goniometer was found to be as reliable and valid as the universal goniometer when measuring active knee flexion. However, the parallelogram goniometer offered clinicians the advantages of obtaining precise angular measurements with fewer adjustments, and a faster application technique. Further studies on the parallelogram goniometer are necessary among individuals presenting with altered range of motion at different joints.