[Impact of the COVID-19 pandemic on adolescent health and development: a role to play for physicians]. / Impact de la pandémie de Covid-19 sur la santé et le développement des jeunes en Suisse - Quel rôle pour les médecins ?

This article summarizes the conclusion of a two-days interprofessional online workshop held under the auspices of the Brocher Foundation. The objectives were to review the impact of COVID on adolescent health and development and to generate some key responses to the situation. The pandemic has severely affected the mental health of a large proportion of adolescents and has significantly reduced access to health care. It has as well disturbed the school education of vulnerable youngsters and decreased social contacts with adults and peers. In the future, authorities should better consider the rights of young people and request their opinion and participation in decision making. Physicians should systematically explore their young patients' opinions and queries regarding the COVID and address problematic situations such as family conflicts, misuse of internet or risky behaviour.

Cet article résume le contenu d'un colloque participatif interprofessionnel en ligne de 2 jours visant à faire un état des lieux et à élaborer des réponses à la situation des adolescent·e·s à l'ère du Covid. La pandémie affecte leur santé en réduisant l'accès aux soins (confinement) et en induisant des problèmes psychologiques chez certains d'entre eux. Elle affecte la formation et la scolarité des plus démunis, réduit les contacts sociaux avec les adultes et les pairs. À l'avenir, les autorités devraient mieux respecter les droits des jeunes en sollicitant leur avis et leur participation et en adaptant leurs messages. Les médecins doivent, lors des consultations avec eux, offrir systématiquement un dialogue et des informations, et repérer des problématiques telles que conflits familiaux, abus d'internet ou prise de risque sanitaire.

The tissue-type plasminogen activator-plasminogen activator inhibitor 1 complex promotes neurovascular injury in brain trauma: evidence from mice and humans.

The neurovascular unit provides a dynamic interface between the circulation and central nervous system. Disruption of neurovascular integrity occurs in numerous brain pathologies including neurotrauma and ischaemic stroke. Tissue plasminogen activator is a serine protease that converts plasminogen to plasmin, a protease that dissolves blood clots. Besides its role in fibrinolysis, tissue plasminogen activator is abundantly expressed in the brain where it mediates extracellular proteolysis. However, proteolytically active tissue plasminogen activator also promotes neurovascular disruption after ischaemic stroke; the molecular mechanisms of this process are still unclear. Tissue plasminogen activator is naturally inhibited by serine protease inhibitors (serpins): plasminogen activator inhibitor-1, neuroserpin or protease nexin-1 that results in the formation of serpin:protease complexes. Proteases and serpin:protease complexes are cleared through high-affinity binding to low-density lipoprotein receptors, but their binding to these receptors can also transmit extracellular signals across the plasma membrane. The matrix metalloproteinases are the second major proteolytic system in the mammalian brain, and like tissue plasminogen activators are pivotal to neurological function but can also degrade structures of the neurovascular unit after injury. Herein, we show that tissue plasminogen activator potentiates neurovascular damage in a dose-dependent manner in a mouse model of neurotrauma. Surprisingly, inhibition of activity following administration of plasminogen activator inhibitor-1 significantly increased cerebrovascular permeability. This led to our finding that formation of complexes between tissue plasminogen activator and plasminogen activator inhibitor-1 in the brain parenchyma facilitates post-traumatic cerebrovascular damage. We demonstrate that following trauma, the complex binds to low-density lipoprotein receptors, triggering the induction of matrix metalloproteinase-3. Accordingly, pharmacological inhibition of matrix metalloproteinase-3 attenuates neurovascular permeability and improves neurological function in injured mice. Our results are clinically relevant, because concentrations of tissue plasminogen activator: plasminogen activator inhibitor-1 complex and matrix metalloproteinase-3 are significantly elevated in cerebrospinal fluid of trauma patients and correlate with neurological outcome. In a separate study, we found that matrix metalloproteinase-3 and albumin, a marker of cerebrovascular damage, were significantly increased in brain tissue of patients with neurotrauma. Perturbation of neurovascular homeostasis causing oedema, inflammation and cell death is an important cause of acute and long-term neurological dysfunction after trauma. A role for the tissue plasminogen activator-matrix metalloproteinase axis in promoting neurovascular disruption after neurotrauma has not been described thus far. Targeting tissue plasminogen activator: plasminogen activator inhibitor-1 complex signalling or downstream matrix metalloproteinase-3 induction may provide viable therapeutic strategies to reduce cerebrovascular permeability after neurotrauma.

The impact of the Ebola epidemics on children's rights: a scoping review.

BACKGROUND: The Ebola virus is known as one of the deadliest pathogens to infect humans. Children represent a minority of Ebola Virus Disease cases globally. Yet, the different Ebola outbreaks in Africa had a wide impact on children's lives and children' rights. OBJECTIVE: Review the published literature to date on Children's rights during Ebola outbreaks. Outcomes shall contribute to get a better understanding of the main limitations or violations of children's rights, identify potential gaps in the literature and support the promotion and protection of children's rights for current and future health crisis. METHODS: A scoping review from PubMed, Medline, Cochrane Library and Web of Science was performed using PRISMA-ScR guidelines. Articles, reports and editorial, published on Ebola Outbreaks between 1976 and 2020 were retrieved. The UNCRC clusters of rights and treaty specific guidelines were used as a framework. Documents were found through a targeted search of websites from international or regional organisations involved in Ebola crises and children's protection. RESULTS: 48 articles and reports were reviewed. Few documents focused solely on children's rights. Several articles covered the topic of children and Ebola outbreaks. Most of the data are linked to basic health, education, discrimination of orphans and survivors. 31% of the reviewed articles underline the violence against the children (rape, abuse, Female genital mutilations), while 21% focus on the right to education. 23% cover the topic of orphans. Impact on mental health and SRH were amongst the other covered topics. CONCLUSION: A lack of data on children's rights and their violations during epidemics is observed. Regional and international collaboration is needed to document the situation of children in health emergencies. Health measures and strategies based on children's opinions and raising awareness of their crucial role in society is key. Child-centred guidelines should be developed based on these elements.

Compartment- and context-specific changes in tissue-type plasminogen activator (tPA) activity following brain injury and pharmacological stimulation.

Tissue-type plasminogen activator (tPA) is a major protease of the central nervous system. Most studies to date have used in situ- or gel-based zymographic assays to monitor in vivo changes in neural tPA activity. In this study, we demonstrate that the amidolytic assay can be adapted to accurately detect changes in net tPA activity in mouse brain tissues. Using the amidolytic assay, we examined differences in net tPA activity in the cerebral cortex, sub-cortical structures and cerebellum in wildtype (WT) and tPA(-/-) mice, and in transgenic mice selectively overexpressing tPA in neurons. In addition, we assessed changes in endogenous net tPA activity in WT mice following morphine administration, epileptic seizures, traumatic brain injury and ischaemic stroke-neurological settings in which tPA has a known functional role. Under these conditions, acute and compartment-specific regulation of tPA activity was observed. tPA also participates in various forms of chronic neurodegeneration. Accordingly, we assessed tPA activity levels in mouse models of Alzheimer's disease (AD) and spinocerebellar ataxia type-1 (SCA1). Decreased tPA activity was detected in the cortex and subcortex of AD mice, whereas increased tPA activity was found in the cerebellum of SCA1 mice. These findings extend the existing hypotheses that low tPA activity promotes AD, whereas increased tPA activity contributes to cerebellar degeneration. Collectively, our results exemplify the utility of the amidolytic assay and emphasise tPA as a complex mediator of brain function and dysfunction. On the basis of this evidence, we propose that alterations in tPA activity levels could be used as a biomarker for perturbations in brain homeostasis.

Beta- and gamma-cytoplasmic actins are required for meiosis in mouse oocytes.

In mammals, female meiosis consists of two asymmetric cell divisions, which generate a large haploid oocyte and two small polar bodies. Asymmetric partitioning of the cytoplasm results from migration of the meiotic spindle toward the cortex and requires actin filaments. However, the subcellular localization and the role of the existing two cytoplasmic actin (CYA) isoforms, beta and gamma, have not been characterized. We show that beta- and gamma-CYA are differentially distributed in the maturing oocyte from late metaphase I as well as in preimplantation embryos. Gamma-CYA is preferentially enriched in oocyte cortices and is absent from all cell-cell contact areas from metaphase II until the blastocyst stage. Beta-CYA is enriched in contractile structures, at cytokinesis, at cell-cell contacts, and around the forming blastocoel. Alteration of beta- or gamma-CYA function by isoform-specific antibody microinjection suggests that gamma-CYA holds a major and specific role in the establishment and/or maintenance of asymmetry in meiosis I and in the maintenance of overall cortical integrity. In contrast, beta- and gamma-CYA, together, appear to participate in the formation and the cortical anchorage of the second meiotic spindle in waiting for fertilization. Finally, differences in gamma-CYA expression are amongst the earliest markers of cell fate determination in development.

PACS1-Neurodevelopmental disorder: clinical features and trial readiness.

BACKGROUND: PACS1-Neurodevelopmental Disorder (PACS1-NDD) is an ultra-rare condition due to a recurrent mutation in the PACS1 gene. Little systematically collected data exist about the functional abilities and neurodevelopmental morbidities in children with PACS1-NDD METHODS: Parents of individuals with PACS1-NDD completed an on-line survey designed collaboratively by researchers, parents, and clinicians. Analyses focused on those with a confirmed R203W variant. RESULTS: Of 35 individuals with confirmed variants, 18 (51%) were female. The median age was 8 years (interquartile range 4.5-15). Seventeen (49%) had a diagnosis of epilepsy. Twelve (40%, of 30 responding to the question) reported autism and (N = 11/30, 37%) reported features of autism. Most children walked independently (N = 29/32, 91%), had a pincer grasp (N = 23/32, 72%), could feed themselves independently (N = 15/32, 47%), and used speech (N = 23/32, 72%). Sixteen of twenty-nine (55%) had simple pre-academic skills. Neither epilepsy nor autism was associated with functional abilities or other clinical features (all P > 0.05). CONCLUSIONS: PACS1-NDD is a moderately-severe intellectual disability syndrome in which seizures occur but are not a defining or primary feature. Successful precision medicine clinical trials for this ultra-rare disorder must target important core features of this disorder and utilize assessment tools commensurate with the level of function in this clinical population.

Building a multisystemic understanding of societal resilience to the COVID-19 pandemic.

The current global systemic crisis reveals how globalised societies are unprepared to face a pandemic. Beyond the dramatic loss of human life, the COVID-19 pandemic has triggered widespread disturbances in health, social, economic, environmental and governance systems in many countries across the world. Resilience describes the capacities of natural and human systems to prevent, react to and recover from shocks. Societal resilience to the current COVID-19 pandemic relates to the ability of societies in maintaining their core functions while minimising the impact of the pandemic and other societal effects. Drawing on the emerging evidence about resilience in health, social, economic, environmental and governance systems, this paper delineates a multisystemic understanding of societal resilience to COVID-19. Such an understanding provides the foundation for an integrated approach to build societal resilience to current and future pandemics.

Testis determination requires insulin receptor family function in mice.

In mice, gonads are formed shortly before embryonic day 10.5 by the thickening of the mesonephros and consist of somatic cells and migratory primordial germ cells. The male sex-determining process is set in motion by the sex-determining region of the Y chromosome (Sry), which triggers differentiation of the Sertoli cell lineage. In turn, Sertoli cells function as organizing centres and direct differentiation of the testis. In the absence of Sry expression, neither XX nor XY gonads develop testes, and alterations in Sry expression are often associated with abnormal sexual differentiation. The molecular signalling mechanisms by which Sry specifies the male pathway and models the undifferentiated gonad are unknown. Here we show that the insulin receptor tyrosine kinase family, comprising Ir, Igf1r and Irr, is required for the appearance of male gonads and thus for male sexual differentiation. XY mice that are mutant for all three receptors develop ovaries and show a completely female phenotype. Reduced expression of both Sry and the early testis-specific marker Sox9 indicates that the insulin signalling pathway is required for male sex determination.

The serpin Spn5 is essential for wing expansion in Drosophila melanogaster.

Serpins, a superfamily of protease inhibitors, control proteolytic cascades in many physiological processes. Genomic studies have revealed the presence of a high number of serpin-encoding genes in Drosophila melanogaster, but their functions remain largely unknown. In a biochemical screen designed to detect protease inhibitors that may be implicated in early Drosophila development, we identified in embryos a ligand that forms a 67 kDa SDS-stable complex with the broad spectrum protease trypsin. Characterization of this ligand revealed it to be the recently described serpin, Spn5. Expression analysis by in situ and Northern blot hybridization indicated maternal transmission of the transcript as well as zygotic expression in many larval, pupal and adult tissues. Targeted repression by RNA interference did not alter early embryogenesis but resulted in a complete defect in the unfolding and expansion of the wings of freshly eclosed mutant flies, without other detectable effects on development.

An inhibitor of serine proteases, neuroserpin, acts as a neuroprotective agent in a mouse model of neurodegenerative disease.

Various studies suggest that proteolytic activity may be involved in a number of neurodegenerative disorders, including stroke and seizure. In this report, we examined the role of tryptic serine proteases, plasminogen activators (PAs), in the evolution of a neurodegenerative disease. Transgenic mice overexpressing an axonally secreted inhibitor of serine proteases (neuroserpin) were crossed with mice characterized by a "dying-back" motor neuron disease [progressive motor neuronopathy (pmn/pmn)]. Compared with pmn/pmn mice that showed an increase in PA activity, double mutant mice had decreased PA activity in sciatic nerves and spinal cord; their lifespan was increased by 50%, their motor behavior was stabilized, and histological analysis revealed increased numbers of myelinated axons and rescue of motoneuron number and size. This is the first report showing that a class of serine proteases (PAs) may be involved in the pathogenesis of a motor neuron disease and more specifically in axonal degeneration. Inhibiting serine proteases could offer a new strategy for delaying these disorders.

Estrogen receptor alpha is a major contributor to estrogen-mediated fetal testis dysgenesis and cryptorchidism.

Failure of the testes to descend into the scrotum (cryptorchidism) is one of the most common birth defects in humans. In utero exposure to estrogens, such as 17beta-estradiol (E2) or the synthetic estrogen diethylstilbestrol (DES), down-regulates insulin-like 3 (Insl3) expression in embryonic Leydig cells, which in turn results in cryptorchidism in mice. To identify the molecular mechanism whereby xenoestrogens block Insl3 gene transcription, we performed a microarray analysis of wild-type or estrogen receptor (ER) alpha-mutant testes exposed in utero to pharmacological doses of E2 or DES. Six and 31 genes were respectively down-regulated and up-regulated by estrogen exposure (> or =4-fold). All six genes down-regulated by estrogen exposure, including Insl3 and the steroidogenic genes steroidogenic acute regulatory protein and cytochrome P450 17alpha-hydroxylase/17,20-lyase, were done so by an ERalpha-dependent mechanism. In contrast, up-regulation was mediated either by ERalpha for 12 genes or by an independent mechanism for the 19 remaining genes. Finally, we show that Insl3 gene expression and testicular descent were not affected by in utero exposure to E2 or DES in ERalpha mutant mice, whereas absence of ERbeta did not influence the effect of these estrogens. Collectively, these data demonstrate that xenoestrogens inhibit the endocrine functions of fetal Leydig cells through an ERalpha-dependent mechanism.

A phytoestrogen-rich diet increases energy expenditure and decreases adiposity in mice.

BACKGROUND: Obesity is an increasingly prevalent health problem, and natural effective therapeutic approaches are required to prevent its occurrence. Phytoestrogens are plant-derived compounds with estrogenic activities; they can bind to both estrogen receptors alpha and beta and mimic the action of estrogens on target organs. OBJECTIVES: The purpose of this study was to examine the influence of soy-derived phytoestrogens on energy balance and metabolism. METHODS: Male outbred mice (CD-1) were allowed ad libitum access to either a high soy-containing diet or a soy-free diet from conception to adulthood. We measured circulating serum isoflavone levels using reverse-phase solid-phase extraction for subsequent liquid chromatography electrospray tandem mass spectrometry analysis. Adult animals were analyzed for body composition by dual-energy X-ray absorptiometry, locomotor activity by running-wheel experiments, respiratory exchange rate by indirect calorimetry, and food intake using metabolic cages. Quantitative reverse transcriptase-polymerase chain reaction was performed to determine the expression of hypothalamic neuropeptide genes. RESULTS: We found that adult mice fed a soy-rich diet had reduced body weight, adiposity, and resistance to cold. This lean phenotype was associated with an increase in lipid oxidation due to a preferential use of lipids as fuel source and an increase in locomotor activity. The modulation of energy balance was associated with a central effect of phytoestrogens on the expression of hypothalamic neuropeptides, including agouti-related protein. CONCLUSION: The data suggest that dietary soy could have beneficial effects on obesity, but they also emphasize the importance of monitoring the phytoestrogen content of diets as a parameter of variability in animal experiments.

Emotions are building up in the field of extracellular proteolysis.

Activity-dependent remodeling of neural connections might require localized extracellular proteolysis. The tissue-type plasminogen activator (tPA)-plasmin proteolytic system is expressed in different regions of the central nervous system, in the context of a variety of physiological and pathological processes. Accumulating evidence regarding the expression and role of tPA and its inhibitors suggests that extracellular proteolysis is a key player in the biology of memory, emotions and neurodegeneration.

Overexpression of focal adhesion kinase in vascular endothelial cells promotes angiogenesis in transgenic mice.

OBJECTIVE: Focal adhesion kinase is implicated in the regulation of cell adhesion, migration, survival, and cell-cycle progression. However, the functions of focal adhesion kinase in endothelial cell (EC) in vivo remain unclear. This study aims to examine the role of FAK in EC function and angiogenesis in vivo by transgenic mice approach. METHOD: We generated transgenic mice which overexpressed chicken FAK in vascular endothelial cell under the control of the Tie-2 promoter and enhancer. FAK transgene was detected by RT-PCR, immunoprecipitation, and Western blot. The effect of FAK overexpression on angiogenesis was determined using skin wound healing and ischemia skeleton muscle models. RESULTS: Expression of FAK transgene was detected in all vessel-rich tissues. Expression of FAK protein was verified by antibody specific for the exogenous chicken FAK in lung homogenates and isolated EC. In the wound-induced angiogenesis model, the number of vessels in the granulation tissue of healing wound was significantly increased in the transgenic mouse compared to that of wild-type control mice. Similarly, in the ischemia skeleton muscle model, the density of capillaries was significantly increased in the transgenic mouse. CONCLUSION: These results indicate that FAK may play an important role in the promotion of angiogenesis in vivo.

Induction of enhanced green fluorescent protein expression in response to lesions in the nervous system.

We have generated a mouse strain carrying a transgene driven by a strong and ubiquitous promoter (human cytomegalovirus hCMV/beta-actin) and containing an enhanced green fluorescent protein (eGFP) coding sequence upstream of the 3' untranslated region (3'UTR) of tissue-type plasminogen activator (t-PA) mRNA. The 3'UTR of t-PA mRNA is known to be involved in the reversible deadenylation and translational repression of transcripts in mouse oocytes. hCMV/beta-actin-eGFP-3'UTR t-PA transgenic mice express eGFP mRNA in all brain structures analyzed but lack eGFP fluorescence, with the exception of blood vessels, choroid plexus, and Purkinje cells. Taking advantage of these features, we tested whether certain pathological conditions, in particular injuries of the nervous system, might trigger eGFP fluorescence in traumatized cells or neurons. From this perspective, we analyzed eGFP mRNA expression and eGFP fluorescence in experimental models of nervous system lesions, such as motoneuron axotomy and cerebral stroke induced by middle cerebral artery occlusion. We found an increase in eGFP fluorescence in specific brain areas in cells suffering or reacting to these injuries. This increased fluorescence is correlated with an increased transcription of eGFP in lesioned cells, presumably enhanced by a release of the translational silencing mediated by the 3'UTR region of the t-PA mRNA. This transgenic mouse model may prove useful to study the development of neurodegenerative lesions.

Dicer1 depletion in male germ cells leads to infertility due to cumulative meiotic and spermiogenic defects.

BACKGROUND: Spermatogenesis is a complex biological process that requires a highly specialized control of gene expression. In the past decade, small non-coding RNAs have emerged as critical regulators of gene expression both at the transcriptional and post-transcriptional level. DICER1, an RNAse III endonuclease, is essential for the biogenesis of several classes of small RNAs, including microRNAs (miRNAs) and endogenous small interfering RNAs (endo-siRNAs), but is also critical for the degradation of toxic transposable elements. In this study, we investigated to which extent DICER1 is required for germ cell development and the progress of spermatogenesis in mice. PRINCIPAL FINDINGS: We show that the selective ablation of Dicer1 at the early onset of male germ cell development leads to infertility, due to multiple cumulative defects at the meiotic and post-meiotic stages culminating with the absence of functional spermatozoa. Alterations were observed in the first spermatogenic wave and include delayed progression of spermatocytes to prophase I and increased apoptosis, resulting in a reduced number of round spermatids. The transition from round to mature spermatozoa was also severely affected, since the few spermatozoa formed in mutant animals were immobile and misshapen, exhibiting morphological defects of the head and flagellum. We also found evidence that the expression of transposable elements of the SINE family is up-regulated in Dicer1-depleted spermatocytes. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that DICER1 is dispensable for spermatogonial stem cell renewal and mitotic proliferation, but is required for germ cell differentiation through the meiotic and haploid phases of spermatogenesis.

Potential detrimental effects of a phytoestrogen-rich diet on male fertility in mice.

Soy and soy-based products are widely consumed by infants and adult individuals. There has been speculation that the presence of isoflavone phytoestrogens in soybean cause adverse effects on the development and function of the male reproductive system. The purpose of this study was to examine the influence of dietary soy and phytoestrogens on testicular and reproductive functions. Male mice were fed from conception to adulthood with either a high soy-containing diet or a soy-free diet. Although adult mice fed a soy-rich diet exhibited normal male behaviour and were fertile, we observed a reduced proportion of haploid germ cells in testes correlating with a 25% decrease in epididymal sperm counts and a 21% reduction in litter size. LH and androgens levels were not affected but transcripts coding for androgen-response genes in Sertoli cells and Gapd-s, a germ cell-specific gene involved in sperm glycolysis and mobility were significantly reduced. In addition, we found that dietary soy decreased the size of the seminal vesicle but without affecting its proteolytic activity. Taken together, these studies show that long-term exposure to dietary soy and phytoestrogens may affect male reproductive function resulting in a small decrease in sperm count and fertility.

Complementary pathways in mammalian female sex determination.

In mammals, the sex of the embryo is determined by the fate of the gonad. Recent papers, including one in BMC Developmental Biology, shed light on the molecular regulation of ovarian development and suggest that the R-spondin1/Wnt4/beta-catenin pathway and the Foxl2 transcription factor act in a complementary manner to promote ovarian fate and to repress testicular development.

Dcp1-bodies in mouse oocytes.

Processing bodies (P-bodies) are cytoplasmic granules involved in the storage and degradation of mRNAs. In somatic cells, their formation involves miRNA-mediated mRNA silencing. Many P-body protein components are also found in germ cell granules, such as in mammalian spermatocytes. In fully grown mammalian oocytes, where changes in gene expression depend entirely on translational control, RNA granules have not as yet been characterized. Here we show the presence of P-body-like foci in mouse oocytes, as revealed by the presence of Dcp1a and the colocalization of RNA-associated protein 55 (RAP55) and the DEAD box RNA helicase Rck/p54, two proteins associated with P-bodies and translational control. These P-body-like structures have been called Dcp1-bodies and in meiotically arrested primary oocytes, two types can be distinguished based on their size. They also have different protein partners and sensitivities to the depletion of endogenous siRNA/miRNA and translational inhibitors. However, both type progressively disappear during in vitro meiotic maturation and are virtually absent in metaphase II-arrested secondary oocytes. Moreover, this disassembly of hDcp1a-bodies is concomitant with the posttranslational modification of EGFP-hDcp1a.