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Background: Facioscapulohumeral muscular dystrophy (FSHD) is one of the most common myopathies in adults, displaying a progressive, frequently asymmetric involvement of a typical muscles' pattern. FSHD is associated with epigenetic derepression of the polymorphic D4Z4 repeat on chromosome 4q, leading to DUX4 retrogene toxic expression in skeletal muscles. Identifying biomarkers that correlate with disease severity would facilitate clinical management and assess potential FSHD therapeutics' efficacy., Objectives: This study purpose was to analyze serum cytokines to identify potential biomarkers in a large cohort of adult patients with FSHD., Methods: We retrospectively measured the levels of 20 pro-inflammatory and regulatory cytokines in sera from 100 genetically confirmed adult FSHD1 patients. Associations between cytokine concentrations and various clinical scores were investigated. We then measured serum and muscle interleukin 6 (IL-6) levels in a validated FSHD-like mouse model, ranging in severity and DUX4 expression., Results: IL-6 was identified as the only cytokine with a concentration correlating with several clinical severity and functional scores, including Clinical Severity Score, Manual Muscle Testing sum score, Brooke and Vignos scores. Further, FSHD patients displayed overall IL-6 levels more than twice high as control, and patients with milder phenotypes exhibited lower IL-6 serum concentration than those with severe muscular weakness. Lastly, an FSHD-like mouse model analysis confirmed that IL-6 levels positively correlate with disease severity and DUX4 expression., Conclusions: Serum IL-6, therefore, shows promise as a serum biomarker of FSHD severity in a large cohort of FSHD1 adult patients.

A pedigree of subjects presented with frontonasal dysplasia (FND). Genome sequencing and analysis identified a p.L165F missense variant in the homeodomain of the transcription factor ALX1 which was imputed to be pathogenic. Induced pluripotent stem cells (iPSC) were derived from the subjects and differentiated to neural crest cells (NCC). NCC derived from ALX1 L165F/L165F iPSC were more sensitive to apoptosis, showed an elevated expression of several neural crest progenitor state markers, and exhibited impaired migration compared to wild-type controls. NCC migration was evaluated in vivo using lineage tracing in a zebrafish model, which revealed defective migration of the anterior NCC stream that contributes to the median portion of the anterior neurocranium, phenocopying the clinical presentation. Analysis of human NCC culture media revealed a change in the level of bone morphogenic proteins (BMP), with a low level of BMP2 and a high level of BMP9. Soluble BMP2 and BMP9 antagonist treatments were able to rescue the defective migration phenotype. Taken together, these results demonstrate a mechanistic requirement of ALX1 in NCC development and migration., (© 2020 The Authors. Published under the terms of the CC BY 4.0 license.)

Andersen's syndrome is a rare disorder affecting muscle, heart, and bone that is associated with mutations leading to a loss of function of the inwardly rectifying K + channel Kir2.1. Although the Kir2.1 function can be anticipated in excitable cells by controlling the electrical activity, its role in non-excitable cells remains to be investigated. Using Andersen's syndrome-induced pluripotent stem cells, we investigated the cellular and molecular events during the osteoblastic and chondrogenic differentiation that are affected by the loss of the Ik1 current. We show that loss of Kir2.1 channel function impairs both osteoblastic and chondrogenic processes through the downregulation of master gene expression. This downregulation is the result of an impairment of the bone morphogenetic proteins signaling pathway through dephosphorylation of the Smad proteins. Restoring Kir2.1 channel function in Andersen's syndrome cells rescued master genes expression and restored normal osteoblast and chondrocyte behavior. Our results show that Kir2.1-mediated activity controls endochondral and intramembranous ossification signaling pathways. © 2018 American Society for Bone and Mineral Research., (© 2018 American Society for Bone and Mineral Research.)

Despite mesenchymal stromal cells (MSCs) are considered as a promising source of cells to modulate immune functions on cells from innate and adaptive immune systems, their clinical use remains restricted (few number, limited in vitro expansion, absence of a full phenotypic characterization, few insights on their in vivo fate). Standardized MSCs derived in vitro from human-induced pluripotent stem (huIPS) cells, remediating part of these issues, are considered as well as a valuable tool for therapeutic approaches, but their functions remained to be fully characterized. We generated multipotent MSCs derived from huiPS cells (huiPS-MSCs), and focusing on their immunosuppressive activity, we showed that human T-cell activation in coculture with huiPS-MSCs was significantly reduced. We also observed the generation of functional CD4 + FoxP3 + regulatory T (Treg) cells. Further tested in vivo in a model of human T-cell expansion in immune-deficient NSG mice, huiPS-MSCs immunosuppressive activity prevented the circulation and the accumulation of activated human T cells. Intracytoplasmic labeling of cytokines produced by the recovered T cells showed reduced percentages of human-differentiated T cells producing Th1 inflammatory cytokines. By contrast, T cells producing IL-10 and FoxP3 + -Treg cells, absent in non-treated animals, were detected in huiPS-MSCs treated mice. For the first time, these results highlight the immunosuppressive activity of the huiPS-MSCs on human T-cell stimulation with a concomitant generation of human Treg cells in vivo . They may favor the development of new tools and strategies based on the use of huiPS cells and their derivatives for the induction of immune tolerance.

Andersen's syndrome (AS) is a rare disorder characterized by a triad of symptoms: periodic paralysis, cardiac arrhythmia, and bone developmental defects. Most of the patients carry mutations on the inward rectifier potassium channel Kir2.1 encoded by the KCNJ2 gene. kcnj2 knockout mice are lethal at birth preventing, hence, thorough investigations of the physiological and pathophysiological events. We have generated induced pluripotent stem (iPS) cells from healthy as well as from AS patient muscular biopsies using the four-gene cassette required for cellular reprogramming (Oct4, Sox2, Klf4, and c-Myc). The generated AS-iPS cells exhibited the gold standard requirement for iPS cells: expression of genetics and surface pluripotent markers, strong alkaline phosphatase activity, self-renewal, and could be differentiated by the formation of embryoid bodies (EBs) into the three germ layers. Sequencing of the entire coding sequence of the KCNJ2 gene, in AS-iPS cells, revealed that the reprogramming process did not revert the Andersen's syndrome-associated mutation. Moreover, no difference was observed between control and AS-iPS cells in terms of pluripotent markers' expression, self-renewal, and three germ layer differentiation. Interestingly, expression of osteogenic markers are lower in EB-differentiated AS-iPS compared to control iPS cells. Our results showed that the Kir2.1 channel is not important for the reprogramming process and the early step of the development in vitro. However, the osteogenic machinery appears to be hastened in AS-iPS cells, strongly indicating that the generated AS-iPS cells could be a good model to better understand the AS pathophysiology.

Innate and adaptive immune cells work in concert to generate efficient protection at mucosal surface. Vaginal mucosa is an epithelial tissue that contains innate and adaptive immune effector cells. Our previous studies demonstrated that vaginal administration of Cholera toxin -based vaccines generate antigen-specific CD8 T cells through the stimulation of local dendritic cells (DC). Innate lymphoid cells (ILC) are a group of lymphocytes localized in epithelial tissues that have important immune functions against pathogens and in tissue homeostasis. Their contribution to vaccine-induced mucosal T cell responses is an important issue for the design of protective vaccines. We report here that the vaginal mucosa contains a heterogeneous population of NKp46+ ILC that includes conventional NK cells and ILC1-like cells. We show that vaginal NKp46+ ILC dampen vaccine-induced CD8 T cell responses generated after local immunization. Indeed, in vivo depletion of NKp46+ ILC with anti-NK1.1 antibody or NKG2D blockade increases the magnitude of vaginal OVA-specific CD8 T cells. Furthermore, such treatments also increase the number of DC in the vagina. NKG2D ligands being expressed by vaginal DC but not by CD8 T cells, these results support that NKp46+ ILC limit mucosal CD8 T cell responses indirectly through the NKG2D-dependent elimination of vaginal DC. Our data reveal an unappreciated role of NKp46+ ILC in the regulation of mucosal CD8 T cell responses.

The present study investigates the relationships between copper (Cu) and zinc (Zn) concentrations in sediment, pore water and their bioaccumulation in the polychaete Nereis (Alitta) virens, as well as the importance of site-specific sediment characteristics in that process. Sediment, pore water and N. virens were sampled from seven sites with different pollution histories along the English Channel coast. Results showed that site-specific metal levels and sediment characteristics were important in determining the bioavailability of metals to worms. Significant correlations were found between Cu in the sediment and in the pore water and between Zn in the pore water and in N. virens. Zn from the pore water was thus more readily available from a dissolved source to N. virens than Cu. Data also showed that metal concentrations in N. virens were lower than those found in other closely related polychaetes, indicating that it may regulate tissue concentrations of Cu and Zn., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Surfactants used in herbicide formulations are generally considered inert with no toxic effects on animals. Polyethoxylated tallow amines (POEAs) are non-ionic surfactants used in many herbicide formulations to promote the penetration of the active matter into plant cuticles. The present study aimed to assess the toxicity of a POEA surfactant system, the Genamin T-200®, on two larval stages of the Pacific oyster, Crassostrea gigas. The embryotoxicity of Genamin T-200® was quantified after 36 hr of exposure, considering both arrested development and abnormalities in D-shaped larvae. The ability of pediveliger larvae to metamorphose was studied after 24 hr exposure to Genamin T-200®. According to the European toxicity classification, the present results suggest that Genamin T-200® could be considered very toxic to embryo larval development, with an EC₅₀ of 262 µg/l, and toxic to metamorphosis processes with an EC₅₀ of 3,027 µg/l. The high toxicity of glyphosate-based formulations compared to the active ingredient and its by-product appears to be due primarily to surfactants.