Transient development of ovotestes in XX Sox9 transgenic mice

AbstractThe sex of an individual results from the paternal transmission of the SRY gene located on the Y chromosome. In turn, SRY initiates Sox9 expression, a transcription factor required for testicular differentiation. Ectopic activation of SOX9 in XX Wt1:Sox9 transgenic mice induces female-to-male sex reversal in adult mice. Here we show that complete sex reversal is preceded by a transient phase of ovotestis differentiation with XX Wt1:Sox9 transgenic gonads containing a testicular central region and one or both ovarian poles indicating that Wt1:Sox9 is not as efficient as Sry to induce male development. In XX Wt1:Sox9Tg/+ gonads, transgenic Sox9 is expressed earlier than Sox9 in XY gonads and is able to induce the expression of EGFP, knocked into the 3′ UTR of Sox9 indicating that SOX9 is involved in the initiation and maintenance of its own expression. However, the delayed onset of expression of endogenous Sox9–EGFP suggests that this activation requires other factors, whose expression depends on SOX9. In the testicular regions of the XX Wt1:Sox9 ovotestes, proliferation of the XX fetal germ cells is hampered and they differentiate as pro-spermatogonia. This indicates that XX germ cells are not competent to respond to proliferative signals released from a testicular environment. In the ovarian regions, despite the continuous mRNA expression of the WT1:Sox9 transgene, the SOX9 protein does not accumulate suggesting that regulation of this gene in ovarian cells involves post-transcriptional mechanisms. Finally, ovarian cells of the XX Wt1:Sox9 ovotestis undergo apoptosis during late embryogenesis leading to complete female-to-male sex reversal of the transgenic mice at birth

Recommendations on clinical trial design for treatment of Mucopolysaccharidosis Type III

Abstract Background Mucopolysaccharidosis type III is a progressive, neurodegenerative lysosomal storage disorder for which there is currently no effective therapy. Though numerous potential therapies are in development, there are several challenges to conducting clinical research in this area. We seek to make recommendations on the approach to clinical research in MPS III, including the selection of outcome measures and trial endpoints, in order to improve the quality and impact of research in this area. Results An international workshop involving academic researchers, clinical experts and industry groups was held in June 2015, with presentations and discussions on disease pathophysiology, biomarkers, potential therapies and clinical outcome measures. A set of recommendations was subsequently prepared by a working group and reviewed by all delegates. We present a series of 11 recommendations regarding the conduct of clinical research, outcome measures and management of natural history data in Mucopolysaccharidosis type III. Conclusions Improving the quality of clinical research in Mucopolysaccharidosis type III will require an open, collaborative and systematic approach between academic researchers, clinicians and industry. Natural history data should be published as soon as possible and ideally collated in a central repository. There should be agreement on outcome measures and instruments for evaluation of clinical outcomes to maximise the effectiveness of current and future clinical research

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The sex of an individual is determined by the fate of the gonad. This organ arises from two different structures: the coelomic epithelium and a mesenchymal part that forms from the mesonephros. The early embryonic gonad can differentiate into a testis or an ovary, thus suggesting that at an early stage the gonad is bipotential. Testis formation requires differentiation of Sertoli cells, which will form the supporting cell lineage of the seminiferous tubules. These cells synthesize Anti-Mullerian Hormone (AMH), which induces regression of the Mullerian duct, thus counteracting the development of female internal genitalia. Moreover, Sertoli cells favor recruitment of other somatic cell lineages migrating from the mesonephros that are also crucial for testis development to occur. The interstitial area of the testis contains the steroidogenic cells (Leydig cells), which have the function of producing androgens. These hormones stimulate the differentiation of internal and external genitalia of the male [for a review see Gonad differentiation depends on the paternal transmission of the sex chromosome. Thus, an XY embryo develops as a male, whereas an XX embryo becomes female. Most of the genes involved in this developmental pathway have been discovered from genetic studies of human XY sex-reversal. At a molecular level, the Y chromosome encodes a testis determining factor, SRY [Sinclair et al., Key Words Abstract In mammals, the sex of the embryo is determined during development by its commitment either to the male or female genetic program regulating testicular or ovarian organogenesis. Major steps towards unraveling sex determination in mammals are achieved by the identification of key genes involved in human pathologies and the application of mouse genetics to analyze their function. While the expression of Sry and Sox9 is sufficient to induce the male developmental program, the molecular pathways that specify ovarian differentiation were unclear before the recent demonstration that mutations in the RSPO1 gene induce femaleto-male sex reversal in XX patients. By generating the corresponding mouse model, we have shown that Rspo1 is so far the earliest known gene controlling the female genetic developmental program. Rspo1 activates the canonical ␤ -catenin signaling pathway required for female somatic cell differentiation and germ cell commitment into meiosis. The aim of this review is to describe the roles of R-spondins (Rspo) in developmental processes and disorders and the current knowledge obtained from murine models. A particular focus will be on Rspo1 and its crucial function in sex determination

Recommendations for initiation and cessation of enzyme replacement therapy in patients with Fabry disease: the European Fabry Working Group consensus document.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.Fabry disease (FD) is a lysosomal storage disorder resulting in progressive nervous system, kidney and heart disease. Enzyme replacement therapy (ERT) may halt or attenuate disease progression. Since administration is burdensome and expensive, appropriate use is mandatory. We aimed to define European consensus recommendations for the initiation and cessation of ERT in patients with FD.A Delphi procedure was conducted with an online survey (n = 28) and a meeting (n = 15). Patient organization representatives were present at the meeting to give their views. Recommendations were accepted with ≥75% agreement and no disagreement.For classically affected males, consensus was achieved that ERT is recommended as soon as there are early clinical signs of kidney, heart or brain involvement, but may be considered in patients of ≥16 years in the absence of clinical signs or symptoms of organ involvement. Classically affected females and males with non-classical FD should be treated as soon as there are early clinical signs of kidney, heart or brain involvement, while treatment may be considered in females with non-classical FD with early clinical signs that are considered to be due to FD. Consensus was achieved that treatment should not be withheld from patients with severe renal insufficiency (GFR < 45 ml/min/1.73 m(2)) and from those on dialysis or with cognitive decline, but carefully considered on an individual basis. Stopping ERT may be considered in patients with end stage FD or other co-morbidities, leading to a life expectancy of <1 year. In those with cognitive decline of any cause, or lack of response for 1 year when the sole indication for ERT is neuropathic pain, stopping ERT may be considered. Also, in patients with end stage renal disease, without an option for renal transplantation, in combination with advanced heart failure (NYHA class IV), cessation of ERT should be considered. ERT in patients who are non-compliant or fail to attend regularly at visits should be stopped.The recommendations can be used as a benchmark for initiation and cessation of ERT, although final decisions should be made on an individual basis. Future collaborative efforts are needed for optimization of these recommendations.Ministry of Health (ZonMw

Vitamin-D-Binding Protein Contributes to the Maintenance of α Cell Function and Glucagon Secretion

Vitamin-D-binding protein (DBP) or group-specific component of serum (GC-globulin) carries vitamin D metabolites from the circulation to target tissues. DBP is highly localized to the liver and pancreatic α cells. Although DBP serum levels, gene polymorphisms, and autoantigens have all been associated with diabetes risk, the underlying mechanisms remain unknown. Here, we show that DBP regulates α cell morphology, α cell function, and glucagon secretion. Deletion of DBP leads to smaller and hyperplastic α cells, altered Na+ channel conductance, impaired α cell activation by low glucose, and reduced rates of glucagon secretion both in vivo and in vitro. Mechanistically, this involves reversible changes in islet microfilament abundance and density, as well as changes in glucagon granule distribution. Defects are also seen in β cell and δ cell function. Immunostaining of human pancreata reveals generalized loss of DBP expression as a feature of late-onset and long-standing, but not early-onset, type 1 diabetes. Thus, DBP regulates α cell phenotype, with implications for diabetes pathogenesis.This article is freely available via Open Access. Click on the Publisher URL to access it via the publisher's site.D.J.H. was supported by MRC ( MR/N00275X/1 and MR/S025618/1 ) and Diabetes UK ( 17/0005681 ) project grants. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Starting Grant 715884 to D.J.H.). L.J.B.B. was supported by a Sir Henry Wellcome Postdoctoral Fellowship ( Wellcome Trust ; 201325/Z/16/Z ) and a Junior Research Fellowship from Trinity College, Oxford . P.E.M. was funded by a foundation grant from the Canadian Institutes of Health Research (grant 148451 ). G.G.L. was supported by a Wellcome Trust Senior Research Fellowship ( 104612/Z/14/Z ). N.G.M. and S.J.R. were supported by Diabetes UK ( 15/0005156 and 16/0005480 ), MRC ( MR/P010695/1 ), and JDRF ( 2-SRA-2018-474-S-B ) project grants. We thank Dr. Deirdre Kavanagh and COMPARE for microscopy assistance. Human pancreas sections were provided by the Alberta Diabetes Institute IsletCore at the University of Alberta in Edmonton, with the assistance of the Human Organ Procurement and Exchange (HOPE) program, Trillium Gift of Life Network (TGLN), and other Canadian organ procurement organizations.published version, accepted version, submitted versio

Mutations involving the SRY-related gene SOX8 are associated with a spectrum of human reproductive anomalies.

© The Author(s) 2018. Published by Oxford University Press. All rights reserved. SOX8 is an HMG-box transcription factor closely related to SRY and SOX9. Deletion of the gene encoding Sox8 in mice causes reproductive dysfunction but the role of SOX8 in humans is unknown. Here, we show that SOX8 is expressed in the somatic cells of the early developing gonad in the human and influences human sex determination. We identified two individuals with 46, XY disorders/differences in sex development (DSD) and chromosomal rearrangements encompassing the SOX8 locus and a third individual with 46, XY DSD and a missense mutation in the HMG-box of SOX8. In vitro functional assays indicate that this mutation alters the biological activity of the protein. As an emerging body of evidence suggests that DSDs and infertility can have common etiologies, we also analysed SOX8 in a cohort of infertile men (n=274) and two independent cohorts of women with primary ovarian insufficiency (POI; n=153 and n=104). SOX8 mutations were found at increased frequency in oligozoospermic men (3.5%; P < 0.05) and POI (5.06%; P=4.5×10 -5 ) as compared with fertile/normospermic control populations (0.74%). The mutant proteins identified altered SOX8 biological activity as compared with the wild-type protein. These data demonstrate that SOX8 plays an important role in human reproduction and SOX8 mutations contribute to a spectrum of phenotypes including 46, XY DSD, male infertility and 46, XX POI.Link_to_subscribed_fulltex

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

A first update on mapping the human genetic architecture of COVID-19

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