[Glioblastomas exploit neuronal properties: a key to new forms of treatment?] / Glioblastome nutzen neuronale Eigenschaften: Schlüssel zu neuen Therapien?

Recent research indicates that glioblastomas exhibit different neural properties that successfully promote tumor growth, colonize the brain and resist standard treatment. This opens up opportunities for new therapeutic strategies giving rise to the new research field of cancer neuroscience at the interface between oncology and neuroscience. It has been observed that glioblastomas as well as other incurable brain tumor entities, form multicellular tumor networks through long cell projections called tumor microtubes that are molecularly controlled by neuronal developmental mechanisms. These networks provide the tumor with efficient communication and resilience to external perturbations and are tumor-intrinsic continuously activated by pacemaker-like tumor cells. In addition, neuron-tumor networks have been discovered that also exploit direct glutamatergic synaptic contacts between nerve cells and tumor cells. These different neuronal mechanisms of the glioblastoma networks contribute to malignancy and resistance, which is why strategies to separate these multicellular networks were developed and are currently being investigated in initial clinical trials with respect to their therapeutic suitability.

Mechanics and self-organization in tissue development.

Self-organization is an all-important feature of living systems that provides the means to achieve specialization and functionality at distinct spatio-temporal scales. Herein, we review this concept by addressing the packing organization of cells, the sorting/compartmentalization phenomenon of cell populations, and the propagation of organizing cues at the tissue level through traveling waves. We elaborate on how different theoretical models and tools from Topology, Physics, and Dynamical Systems have improved the understanding of self-organization by shedding light on the role played by mechanics as a driver of morphogenesis. Altogether, by providing a historical perspective, we show how ideas and hypotheses in the field have been revisited, developed, and/or rejected and what are the open questions that need to be tackled by future research.

Modeling by disruption and a selected-for partner for the nude locus.

A long-standing problem in biology is how to dissect traits for which no tractable model exists. Here, we screen for genes like the nude locus (Foxn1)-genes central to mammalian hair and thymus development-using animals that never evolved hair, thymi, or Foxn1. Fruit flies are morphologically disrupted by the FOXN1 transcription factor and rescued by weak reductions in fly gene function, revealing molecules that potently synergize with FOXN1 to effect dramatic, chaotic change. Strong synergy/effectivity in flies is expected to reflect strong selection/functionality (purpose) in mammals; the more disruptive a molecular interaction is in alien contexts (flies), the more beneficial it will be in its natural, formative contexts (mammals). The approach identifies Aff4 as the first nude-like locus, as murine AFF4 and FOXN1 cooperatively induce similar cutaneous/thymic phenotypes, similar gene expression programs, and the same step of transcription, pre-initiation complex formation. These AFF4 functions are unexpected, as AFF4 also serves as a scaffold in common transcriptional-elongation complexes. Most likely, the approach works because an interaction's power to disrupt is the inevitable consequence of its selected-for power to benefit.

What is typical: Atypical in young children's attention regulation?: Characterizing the developmental spectrum with the Multidimensional Assessment Profiles-Attention Regulation Infant-Toddler (MAPS-AR-IT) Scale.

While attention dysregulation is a promising early indicator of neurodevelopmental risk, in particular attention-deficit/hyperactivity disorder (ADHD), it is difficult to characterize clinical concern due to its developmental expectability at the transition to toddlerhood. Thus, explicating the typical:atypical continuum of risk indicators is among the key future directions for research to promote early identification and intervention, and prevent decrements in the attainment of developmental milestones into early childhood. In this paper, we present the Multidimensional Assessment Profiles-Attention Regulation Infant-Toddler (MAPS-AR-IT) Scale, a novel parent-report survey of dimensional, developmentally specified indicators of attention (dys)regulation. Item Response Theory was employed to characterize the typical:atypical spectrum of both normative and more concerning dysregulation (including the contexts in which behavior occurs). We provide evidence of the validity of this measure in capturing the full typical:atypical spectrum via a longitudinal sample of typically developing children at 12-18 months of age (baseline) via concurrent scores on well-validated temperament and clinical measures. We also examine longitudinal stability and predictive validity if the MAPS-AR-IT via a clinical interview of ADHD symptoms at 24-30 months (follow-up). While not diagnostic, we present evidence of the utility of the MAPS-AR-IT in explicating individual neurodevelopmental risk and elucidating the broader typicality of behaviors related to attention (dys)regulation.

Aunque la desregulación de la atención es un prometedor indicador temprano del riesgo neural de desarrollo, en particular el trastorno de déficit en la atención/hiperactividad (ADHD), es difícil caracterizar las preocupaciones clínicas debido al factor de expectativa de desarrollo al momento de la transición a la temprana niñez. De manera que explicar la progresión típica:atípica de indicadores de riesgo está entre las futuras directrices claves para la investigación con el fin de promover la temprana identificación e intervención, y prevenir disminuciones en el alcance de hitos críticos hacia la temprana niñez. En este ensayo, presentamos la Escala de Perfiles de Evaluación Multidimensional - Regulación de la Atención del Infante-Niño Pequeñito (MAPS-AR-IT) una novedosa encuesta de reporte del progenitor, acerca de la (des)regulación de la atención, dimensional y específica para el desarrollo. Aportamos evidencia de la validez de esta medida para captar la completa gama típica:atípica por medio de una muestra longitudinal de niños típicamente en desarrollo, a los 12-18 meses de edad (edad base) por medio de puntajes concurrentes sobre el temperamento bien validado y las medidas clínicas, así como también la estabilidad longitudinal y la validez de predicción por medio de una entrevista clínica de síntomas de ADHD a los 24-30 meses (seguimiento). Se empleó la Teoría de Respuesta al Asunto para caracterizar la gama típica:atípica tanto de la desregulación normativa como de la más preocupante (incluyendo los contextos en los cuales ocurre el comportamiento). Aunque no se trata de diagnóstico, presentamos evidencia de la utilidad de MAPS-AR-IT para explicar el riesgo individual de desarrollo neural y elucidar el más amplio aspecto típico de comportamientos relacionados con la (des)regulación de la atención.

Bien que la dysrégulation de l'attention soit un indicateur précoce prometteur du risque neurodéveloppemental, en particulier le trouble déficitaire de l'attention/hyperactivité (TDHA) il est difficile de caractériser la préoccupation clinique du fait de sa prévisibilité développementale à la transition à la petite enfance. Par conséquent, expliquer le continuum typique:atypique des indicateurs de risque s'avère être une des directions futures de recherches clé pour promouvoir l'identification et l'intervention précoce, et prévenir les baisses dans la réalisation d'étapes développementales importantes jusque dans la petite enfance. Dans cet article nous présentons l'Echelle Multidimensional Assessment Profiles - Attention Regulation Infant-Toddler (MAPS-AR-IT) (échelle de profils d'évaluation multidimensionnelle - régulation de l'attention bébé-petit enfant, abrégée selon l'anglais MAP-AR-IT), une étude nouvelle basée sur les rapports faits par les parents de la (dys)régulation de l'attention dimensionnelle et spécifiée selon le développement. Nous démontrons la validité de cette mesure en capturant l'éventail total typique:atypique au moyen d'un échantillon longitudinal d'enfants se développement typiquement, à 12-18 mois (ligne de case) au moyen de scores concurrents de mesures cliniques et de tempérament bien validées, ainsi qu''une stabilité longitudinale et d'une validité prédictive au moyen d'un entretien Clinique des symptômes THHA à 24-30 mois (suivi). La Item Response Theory (IRT) a été employée pour caractériser l'éventail typique:atypique de la dysrégulation à la fois normative et celle plus inquiétante (y compris les contextes dans lesquels le comportement prend place). Bien que cela ne soit pas diagnostique, nous présentons la preuve de l'utilité de la MAPS-AR-IT en expliquant le risqué neurodéveloppemental individuel et en élucidant la typicalité plus large de comportements liés à la (dys)régulation de l'attention.

NFIB induces functional astrocytes from human pluripotent stem cell-derived neural precursor cells mimicking in vivo astrogliogenesis.

The ability to generate astrocytes from human pluripotent stem cells (hPSCs) offers a promising cellular model to study the development and physiology of human astrocytes. The extant methods for generating functional astrocytes required long culture periods and there remained much ambiguity on whether such paradigms follow the innate developmental program. In this report, we provided an efficient and rapid method for generating physiologically functional astrocytes from hPSCs. Overexpressing the nuclear factor IB in hPSC-derived neural precursor cells induced a highly enriched astrocyte population in 2 weeks. RNA sequencing and functional analyses demonstrated progressive transcriptomic and physiological changes in the cells, resembling in vivo astrocyte development. Further analyses substantiated previous results and established the MAPK pathway necessary for astrocyte differentiation. Hence, this differentiation paradigm provides a prospective in vitro model for human astrogliogenesis studies and the pathophysiology of neurological diseases concerning astrocytes.

How computational models can help unlock biological systems.

With computation models playing an ever increasing role in the advancement of science, it is important that researchers understand what it means to model something; recognize the implications of the conceptual, mathematical and algorithmic steps of model construction; and comprehend what models can and cannot do. Here, we use examples to show that models can serve a wide variety of roles, including hypothesis testing, generating new insights, deepening understanding, suggesting and interpreting experiments, tracing chains of causation, doing sensitivity analyses, integrating knowledge, and inspiring new approaches. We show that models can bring together information of different kinds and do so across a range of length scales, as they do in multi-scale, multi-faceted embryogenesis models, some of which connect gene expression, the cytoskeleton, cell properties, tissue mechanics, morphogenetic movements and phenotypes. Models cannot replace experiments nor can they prove that particular mechanisms are at work in a given situation. But they can demonstrate whether or not a proposed mechanism is sufficient to produce an observed phenomenon. Although the examples in this article are taken primarily from the field of embryo mechanics, most of the arguments and discussion are applicable to any form of computational modelling.

Brf1 posttranscriptionally regulates pluripotency and differentiation responses downstream of Erk MAP kinase.

AU-rich element mRNA-binding proteins (AUBPs) are key regulators of development, but how they are controlled and what functional roles they play depends on cellular context. Here, we show that Brf1 (zfp36l1), an AUBP from the Zfp36 protein family, operates downstream of FGF/Erk MAP kinase signaling to regulate pluripotency and cell fate decision making in mouse embryonic stem cells (mESCs). FGF/Erk MAP kinase signaling up-regulates Brf1, which disrupts the expression of core pluripotency-associated genes and attenuates mESC self-renewal without inducing differentiation. These regulatory effects are mediated by rapid and direct destabilization of Brf1 targets, such as Nanog mRNA. Enhancing Brf1 expression does not compromise mESC pluripotency but does preferentially regulate mesendoderm commitment during differentiation, accelerating the expression of primitive streak markers. Together, these studies demonstrate that FGF signals use targeted mRNA degradation by Brf1 to enable rapid posttranscriptional control of gene expression in mESCs.

Evolutionarily conserved morphogenetic movements at the vertebrate head-trunk interface coordinate the transport and assembly of hypopharyngeal structures.

The vertebrate head-trunk interface (occipital region) has been heavily remodelled during evolution, and its development is still poorly understood. In extant jawed vertebrates, this region provides muscle precursors for the throat and tongue (hypopharyngeal/hypobranchial/hypoglossal muscle precursors, HMP) that take a stereotype path rostrally along the pharynx and are thought to reach their target sites via active migration. Yet, this projection pattern emerged in jawless vertebrates before the evolution of migratory muscle precursors. This suggests that a so far elusive, more basic transport mechanism must have existed and may still be traceable today. Here we show for the first time that all occipital tissues participate in well-conserved cell movements. These cell movements are spearheaded by the occipital lateral mesoderm and ectoderm that split into two streams. The rostrally directed stream projects along the floor of the pharynx and reaches as far rostrally as the floor of the mandibular arch and outflow tract of the heart. Notably, this stream leads and engulfs the later emerging HMP, neural crest cells and hypoglossal nerve. When we (i) attempted to redirect hypobranchial/hypoglossal muscle precursors towards various attractants, (ii) placed non-migratory muscle precursors into the occipital environment or (iii) molecularly or (iv) genetically rendered muscle precursors non-migratory, they still followed the trajectory set by the occipital lateral mesoderm and ectoderm. Thus, we have discovered evolutionarily conserved morphogenetic movements, driven by the occipital lateral mesoderm and ectoderm, that ensure cell transport and organ assembly at the head-trunk interface.

Annual research review: Rare genotypes and childhood psychopathology--uncovering diverse developmental mechanisms of ADHD risk.

BACKGROUND: Through the increased availability and sophistication of genetic testing, it is now possible to identify causal diagnoses in a growing proportion of children with neurodevelopmental disorders. In addition to developmental delay and intellectual disability, many genetic disorders are associated with high risks of psychopathology, which curtail the wellbeing of affected individuals and their families. Beyond the identification of significant clinical needs, understanding the diverse pathways from rare genetic mutations to cognitive dysfunction and emotional-behavioural disturbance has theoretical and practical utility. METHODS: We overview (based on a strategic search of the literature) the state-of-the-art on causal mechanisms leading to one of the most common childhood behavioural diagnoses - attention deficit hyperactivity disorder (ADHD) - in the context of specific genetic disorders. We focus on new insights emerging from the mapping of causal pathways from identified genetic differences to neuronal biology, brain abnormalities, cognitive processing differences and ultimately behavioural symptoms of ADHD. FINDINGS: First, ADHD research in the context of rare genotypes highlights the complexity of multilevel mechanisms contributing to psychopathology risk. Second, comparisons between genetic disorders associated with similar psychopathology risks can elucidate convergent or distinct mechanisms at each level of analysis, which may inform therapeutic interventions and prognosis. Third, genetic disorders provide an unparalleled opportunity to observe dynamic developmental interactions between neurocognitive risk and behavioural symptoms. Fourth, variation in expression of psychopathology risk within each genetic disorder points to putative moderating and protective factors within the genome and the environment. CONCLUSION: A common imperative emerging within psychopathology research is the need to investigate mechanistically how developmental trajectories converge or diverge between and within genotype-defined groups. Crucially, as genetic predispositions modify interaction dynamics from the outset, longitudinal research is required to understand the multi-level developmental processes that mediate symptom evolution.

A Study of the Developmental Mechanisms of Inter-Team Conflict Processes Within Multi-Team Systems - An Exploratory Analysis Based on a Collaborative R&D Context.

Purpose: The analysis of the pivotal determinants that impact the progression of inter-team conflict processes in multi-team systems, as well as their underlying mechanisms, serves to explicate the developmental framework of said conflict processes. Methodology: This study adopts a vantage point centered on the evolution of inter-team conflict in multi-team systems, with a specific focus on the sequential progression including "conflict latency → conflict perception → conflict management → conflict outcome → conflict feedback. Results: By transmuting qualitative data into quantitative data through the discernment of inter-conceptual relationships' directionality and quantity, this study distills the key chain of relationships between categories. Employing the explanatory structure model, the developmental mechanism of inter-team conflict processes in multi-team systems is unveiled. Notable sources of conflict include team goal identification, team role multiplicity, inter-team relationships, and team competence. Factors that exert a significant influence on conflict management comprise inter-team conflict types, inter-team relationships, team competence, inter-team heterogeneity, team affiliation, and system goals. Reviewing the genuine motivations underlying conflict management behavior, as well as adopting a lengthier temporal perspective, emerges as a crucial consideration when analyzing the implications of conflict management on both the system and the team for evaluative purposes. Inter-team communication emerges as a pivotal influence on the efficacy of conflict management, which, in turn, is influenced by boundary managers, inter-team heterogeneity, and the inter-team interactive memory system. Conclusion: Through an in-depth analysis of the hierarchical interrelationships among factors that influence conflicts within teams, we have established a model for the conflict development process. This model is instrumental in comprehensively understanding the dynamics of conflict evolution within teams. It serves as a reference point for formulating more precise and effective conflict management strategies. Moreover, this model not only offers practical guidance for resolving conflicts within a multi-team framework but also enhances inter-team collaboration. Therefore, it contributes significantly to achieving the objectives of the multi-team system.

Molecular mechanisms of mechanosensing and plasticity of tendons and ligaments.

Tendons and ligaments, crucial components of the musculoskeletal system, connect muscles to bones. In the realm of sports, tendons and ligaments are vulnerable tissues, with injuries such as Achilles tendon rupture and anterior cruciate ligament tears directly impacting an athlete's career. Furthermore, repetitive trauma and tissue degeneration can lead to conditions like secondary osteoarthritis, ultimately affecting the overall quality of life. Recent research highlights the pivotal role of mechanical stress in maintaining homeostasis within tendons and ligaments. This review delves into the latest insights on the structure of tendons and ligaments and the plasticity of tendon tissue in response to mechanical loads.

Integration of Spatial and Temporal Patterning in the Invertebrate and Vertebrate Nervous System.

The nervous system is one of the most sophisticated animal tissues, consisting of thousands of interconnected cell types. How the nervous system develops its diversity from a few neural stem cells remains a challenging question. Spatial and temporal patterning mechanisms provide an efficient model through which diversity can be generated. The molecular mechanism of spatiotemporal patterning has been studied extensively in Drosophila melanogaster, where distinct sets of transcription factors define the spatial domains and temporal windows that give rise to different cell types. Similarly, in vertebrates, spatial domains defined by transcription factors produce different types of neurons in the brain and neural tube. At the same time, different cortical neuronal types are generated within the same cell lineage with a specific birth order. However, we still do not understand how the orthogonal information of spatial and temporal patterning is integrated into the progenitor and post-mitotic cells to combinatorially give rise to different neurons. In this review, after introducing spatial and temporal patterning in Drosophila and mice, we discuss possible mechanisms that neural progenitors may use to integrate spatial and temporal information. We finally review the functional implications of spatial and temporal patterning and conclude envisaging how small alterations of these mechanisms can lead to the evolution of new neuronal cell types.

Processes and pathways in development via digital media: Examples from word learning.

Word learning unfolds over multiple, cascading pathways which support in-the-moment processing and learning. The process is refined with each exposure to a word, and exposures to new words occur across a variety of forms and contexts. However, as children are exposed to more and more digital media, the ways in which children encounter, learn, and build on their vocabulary is also shifting. These shifts represent changes in context, content, and at the level of the child that can lead to negative outcomes. Less work, however, has discussed what these differences mean for how things change in the underlying developmental cascade and learning processes. Here, we suggest that the increasing presence of digital media may shift the developmental pathways for learning (the chain of events that support future learning) but not necessarily the developmental processes (the mechanisms underlying learning). Moreover, the interaction of the two may lead to different behavior and outcomes for learning in a digital era. We argue it is imperative for researchers to not only study how digital media differs from everyday learning, but directly measure if the well-worn pathways, processes, and variables found with decades of research with real items translate to a digital media era.

Why call it developmental bias when it is just development?

The concept of developmental constraints has been central to understand the role of development in morphological evolution. Developmental constraints are classically defined as biases imposed by development on the distribution of morphological variation.This opinion article argues that the concepts of developmental constraints and developmental biases do not accurately represent the role of development in evolution. The concept of developmental constraints was coined to oppose the view that natural selection is all-capable and to highlight the importance of development for understanding evolution. In the modern synthesis, natural selection was seen as the main factor determining the direction of morphological evolution. For that to be the case, morphological variation needs to be isotropic (i.e. equally possible in all directions). The proponents of the developmental constraint concept argued that development makes that some morphological variation is more likely than other (i.e. variation is not isotropic), and that, thus, development constraints evolution by precluding natural selection from being all-capable.This article adds to the idea that development is not compatible with the isotropic expectation by arguing that, in fact, it could not be otherwise: there is no actual reason to expect that development could lead to isotropic morphological variation. It is then argued that, since the isotropic expectation is untenable, the role of development in evolution should not be understood as a departure from such an expectation. The role of development in evolution should be described in an exclusively positive way, as the process determining which directions of morphological variation are possible, instead of negatively, as a process precluding the existence of morphological variation we have no actual reason to expect.This article discusses that this change of perspective is not a mere question of semantics: it leads to a different interpretation of the studies on developmental constraints and to a different research program in evolution and development. This program does not ask whether development constrains evolution. Instead it asks questions such as, for example, how different types of development lead to different types of morphological variation and, together with natural selection, determine the directions in which different lineages evolve.

Retinoids in Embryonic Development.

Retinoids constitute a class of compounds chemically related to vitamin A [...].

Autism spectrum disorder and attention-deficit/hyperactivity disorder in early childhood: A review of unique and shared characteristics and developmental antecedents.

Autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) have overlapping characteristics and etiological factors, but to which extent this applies to infant- and preschool age is less well understood. Comparing the pathways to ASD and ADHD from the earliest possible stages is crucial for understanding how phenotypic overlap emerges and develops. Ultimately, these insights may guide preventative and therapeutic interventions. Here, we review the literature on the core symptoms, temperament and executive function in ASD and ADHD from infancy through preschool age, and draw several conclusions: (1) the co-occurrence of ASD and ADHD increases with age, severity of symptoms and lower IQ, (2) attention problems form a linking pin between early ASD and ADHD, but the behavioral, cognitive and sensory correlates of these attention problems partly diverge between the two conditions, (3) ASD and ADHD share high levels of negative affect, although the underlying motivational and behavioral tendencies seem to differ, and (4) ASD and ADHD share difficulties with control and shifting, but partly opposite behaviors seem to be involved.

Developmental pathways to autism: a review of prospective studies of infants at risk.

Autism Spectrum Disorders (ASDs) are neurodevelopmental disorders characterized by impairments in social interaction and communication, and the presence of restrictive and repetitive behaviors. Symptoms of ASD likely emerge from a complex interaction between pre-existing neurodevelopmental vulnerabilities and the child's environment, modified by compensatory skills and protective factors. Prospective studies of infants at high familial risk for ASD (who have an older sibling with a diagnosis) are beginning to characterize these developmental pathways to the emergence of clinical symptoms. Here, we review the range of behavioral and neurocognitive markers for later ASD that have been identified in high-risk infants in the first years of life. We discuss theoretical implications of emerging patterns, and identify key directions for future work, including potential resolutions to several methodological challenges for the field. Mapping how ASD unfolds from birth is critical to our understanding of the developmental mechanisms underlying this disorder. A more nuanced understanding of developmental pathways to ASD will help us not only to identify children who need early intervention, but also to improve the range of interventions available to them.

Roles of retinoic acid and Tbx1/10 in pharyngeal segmentation: amphioxus and the ancestral chordate condition.

BACKGROUND: Although chordates descend from a segmented ancestor, the evolution of head segmentation has been very controversial for over 150 years. Chordates generally possess a segmented pharynx, but even though anatomical evidence and gene expression analyses suggest homologies between the pharyngeal apparatus of invertebrate chordates, such as the cephalochordate amphioxus, and vertebrates, these homologies remain contested. We, therefore, decided to study the evolution of the chordate head by examining the molecular mechanisms underlying pharyngeal morphogenesis in amphioxus, an animal lacking definitive neural crest. RESULTS: Focusing on the role of retinoic acid (RA) in post-gastrulation pharyngeal morphogenesis, we found that during gastrulation, RA signaling in the endoderm is required for defining pharyngeal and non-pharyngeal domains and that this process involves active degradation of RA anteriorly in the embryo. Subsequent extension of the pharyngeal territory depends on the creation of a low RA environment and is coupled to body elongation. RA further functions in pharyngeal segmentation in a regulatory network involving the mutual inhibition of RA- and Tbx1/10-dependent signaling. CONCLUSIONS: These results indicate that the involvement of RA signaling and its interactions with Tbx1/10 in head segmentation preceded the evolution of neural crest and were thus likely present in the ancestral chordate. Furthermore, developmental comparisons between different deuterostome models suggest that the genetic mechanisms for pharyngeal segmentation are evolutionary ancient and very likely predate the origin of chordates.