Identifying predictors of translocation success in rare plant species.

The fundamental goal of a rare plant translocation is to create self-sustaining populations with the evolutionary resilience to persist in the long term. Yet, most plant translocation syntheses focus on a few factors influencing short-term benchmarks of success (e.g., survival and reproduction). Short-term benchmarks can be misleading when trying to infer future growth and viability because the factors that promote establishment may differ from those required for long-term persistence. We assembled a large (n = 275) and broadly representative data set of well-documented and monitored (7.9 years on average) at-risk plant translocations to identify the most important site attributes, management techniques, and species' traits for six life-cycle benchmarks and population metrics of translocation success. We used the random forest algorithm to quantify the relative importance of 29 predictor variables for each metric of success. Drivers of translocation outcomes varied across time frames and success metrics. Management techniques had the greatest relative influence on the attainment of life-cycle benchmarks and short-term population trends, whereas site attributes and species' traits were more important for population persistence and long-term trends. Specifically, large founder sizes increased the potential for reproduction and recruitment into the next generation, whereas declining habitat quality and the outplanting of species with low seed production led to increased extinction risks and a reduction in potential reproductive output in the long-term, respectively. We also detected novel interactions between some of the most important drivers, such as an increased probability of next-generation recruitment in species with greater seed production rates, but only when coupled with large founder sizes. Because most significant barriers to plant translocation success can be overcome by improving techniques or resolving site-level issues through early intervention and management, we suggest that by combining long-term monitoring with adaptive management, translocation programs can enhance the prospects of achieving long-term success.

Identificación de pronosticadores del éxito de reubicación en especies raras de plantas Resumen El objetivo fundamental de la reubicación de plantas raras es la creación de poblaciones autosuficientes con resiliencia evolutiva que persistan a la larga. De todas maneras, la mayoría de las síntesis de estas reubicaciones se enfocan en unos cuantos factores que influyen sobre los parámetros a corto plazo del éxito (supervivencia y reproducción). Los parámetros a corto plazo pueden ser engañosos si se intenta inferir el crecimiento y la viabilidad en el futuro ya que los factores que promueven el establecimiento pueden diferir de aquellos requeridos para la persistencia a largo plazo. Ensamblamos un conjunto grande de datos representativos en general (n = 275) de las reubicaciones de plantas en riesgo bien documentadas y monitoreadas (7.9 años en promedio) para identificar los atributos de sitio más importantes, las técnicas de manejo y los rasgos de las especies para seis parámetros de ciclos de vida y medidas poblacionales del éxito de reubicación. Usamos el algoritmo de bosque aleatorio para cuantificar la importancia relativa de las 29 variables de pronosticadores para cada medida del éxito. Los factores en los resultados de las reubicaciones variaron con los marcos temporales y las medidas de éxito. Las técnicas de manejo tuvieron la mayor influencia relativa sobre la obtención de parámetros de ciclos de vida y tendencias poblacionales a corto plazo, mientras que los atributos de sitio y los rasgos de la especie fueron más importantes para la persistencia poblacional y las tendencias a largo plazo. En específico, las grandes cantidades de fundadores incrementaron el potencial de reproducción y reclutamiento de la siguiente generación, mientras que la declinación de la calidad del hábitat incrementó el riesgo de extinción y el trasplante de especies con baja producción de semillas redujo el rendimiento del potencial reproductivo a la larga. También detectamos interacciones novedosas entre algunos de los factores más importantes, como el aumento en la probabilidad del reclutamiento en la siguiente generación en especies con tasas mayores de producción de semillas, pero sólo cuando se emparejó con grandes cantidades de fundadores. Ya que las barreras más significativas para el éxito de la reubicación de plantas pueden superarse al mejorar las técnicas o resolver los temas a nivel de sitio por medio de un manejo y una intervención temprana, sugerimos que con la combinación del monitoreo a largo plazo con el manejo adaptativo los programas de reubicación pueden aumentar el prospecto de lograr el éxito a largo plazo.

Physiology and Clinical Manifestations of Pathologic Cranial Suture Widening.

Cranial sutures are complex structures integrating mechanical forces with osteogenesis which are often affected in craniofacial syndromes. While premature fusion is frequently described, rare pathological widening of cranial sutures is a comparatively understudied phenomenon. This narrative review aims to bring to light the biologically variable underlying causes of widened sutures and persistent fontanelles leading to a common outcome. The authors herein present four syndromes, selected from a literature review, and their identified biological mechanisms in the context of altered suture physiology, exploring the roles of progenitor cell differentiation, extracellular matrix production, mineralization, and bone resorption. This article illustrates the gaps in understanding of complex craniofacial disorders, and the potential for further unification of genetics, cellular biology, and clinical pillars of health science research to improve treatment outcomes for patients.

Correcting the F508del-CFTR variant by modulating eukaryotic translation initiation factor 3-mediated translation initiation.

Inherited and somatic rare diseases result from >200,000 genetic variants leading to loss- or gain-of-toxic function, often caused by protein misfolding. Many of these misfolded variants fail to properly interact with other proteins. Understanding the link between factors mediating the transcription, translation, and protein folding of these disease-associated variants remains a major challenge in cell biology. Herein, we utilized the cystic fibrosis transmembrane conductance regulator (CFTR) protein as a model and performed a proteomics-based high-throughput screen (HTS) to identify pathways and components affecting the folding and function of the most common cystic fibrosis-associated mutation, the F508del variant of CFTR. Using a shortest-path algorithm we developed, we mapped HTS hits to the CFTR interactome to provide functional context to the targets and identified the eukaryotic translation initiation factor 3a (eIF3a) as a central hub for the biogenesis of CFTR. Of note, siRNA-mediated silencing of eIF3a reduced the polysome-to-monosome ratio in F508del-expressing cells, which, in turn, decreased the translation of CFTR variants, leading to increased CFTR stability, trafficking, and function at the cell surface. This finding suggested that eIF3a is involved in mediating the impact of genetic variations in CFTR on the folding of this protein. We posit that the number of ribosomes on a CFTR mRNA transcript is inversely correlated with the stability of the translated polypeptide. Polysome-based translation challenges the capacity of the proteostasis environment to balance message fidelity with protein folding, leading to disease. We suggest that this deficit can be corrected through control of translation initiation.

Silencing of the Hsp70-specific nucleotide-exchange factor BAG3 corrects the F508del-CFTR variant by restoring autophagy.

The protein chaperones heat shock protein 70 (Hsp70) and Hsp90 are required for de novo folding of proteins and protect against misfolding-related cellular stresses by directing misfolded or slowly folding proteins to the ubiquitin/proteasome system (UPS) or autophagy/lysosomal degradation pathways. Here, we examined the role of the Bcl2-associated athanogene (BAG) family of Hsp70-specific nucleotide-exchange factors in the biogenesis and functional correction of genetic variants of the cystic fibrosis transmembrane conductance regulator (CFTR) whose mutations cause cystic fibrosis (CF). We show that siRNA-mediated silencing of BAG1 and -3, two BAG members linked to the clearance of misfolded proteins via the UPS and autophagy pathways, respectively, leads to functional correction of F508del-CFTR and other disease-associated CFTR variants. BAG3 silencing was the most effective, leading to improved F508del-CFTR stability, trafficking, and restoration of cell-surface function, both alone and in combination with the FDA-approved CFTR corrector, VX-809. We also found that the BAG3 silencing-mediated correction of F508del-CFTR restores the autophagy pathway, which is defective in F508del-CFTR-expressing cells, likely because of the maladaptive stress response in CF pathophysiology. These results highlight the potential therapeutic benefits of targeting the cellular chaperone system to improve the functional folding of CFTR variants contributing to CF and possibly other protein-misfolding-associated diseases.

Modulation of the maladaptive stress response to manage diseases of protein folding.

Diseases of protein folding arise because of the inability of an altered peptide sequence to properly engage protein homeostasis components that direct protein folding and function. To identify global principles of misfolding disease pathology we examined the impact of the local folding environment in alpha-1-antitrypsin deficiency (AATD), Niemann-Pick type C1 disease (NPC1), Alzheimer's disease (AD), and cystic fibrosis (CF). Using distinct models, including patient-derived cell lines and primary epithelium, mouse brain tissue, and Caenorhabditis elegans, we found that chronic expression of misfolded proteins not only triggers the sustained activation of the heat shock response (HSR) pathway, but that this sustained activation is maladaptive. In diseased cells, maladaptation alters protein structure-function relationships, impacts protein folding in the cytosol, and further exacerbates the disease state. We show that down-regulation of this maladaptive stress response (MSR), through silencing of HSF1, the master regulator of the HSR, restores cellular protein folding and improves the disease phenotype. We propose that restoration of a more physiological proteostatic environment will strongly impact the management and progression of loss-of-function and gain-of-toxic-function phenotypes common in human disease.

Spatial Multiomics Reveal the Role of Wnt Modulator, Dkk2, in Palatogenesis.

Multiple genetic and environmental etiologies contribute to the pathogenesis of cleft palate, which constitutes the most common among the inherited disorders of the craniofacial complex. Insights into the molecular mechanisms regulating osteogenic differentiation and patterning in the palate during embryogenesis are limited and needed for the development of innovative diagnostics and cures. This study utilized the Pax9-/- mouse model with a consistent phenotype of cleft secondary palate to investigate the role of Pax9 in the process of palatal osteogenesis. While prior research had identified upregulation of Wnt pathway modulators Dkk1 and Dkk2 in Pax9-/- palate mesenchyme, limitations of spatial resolution and technology restricted a more robust analysis. Here, data from single-nucleus transcriptomics and chromatin accessibility assays validated by in situ highly multiplex targeted single-cell spatial profiling technology suggest a distinct relationship between Pax9+ and osteogenic populations. Loss of Pax9 results in spatially restricted osteogenic domains bounded by Dkk2, which normally interfaces with Pax9 in the mesenchyme. These results suggest that Pax9-dependent Wnt signaling modulators influence osteogenic programming during palate formation, potentially contributing to the observed cleft palate phenotype.

Tendon-associated gene expression precedes osteogenesis in mid-palatal suture establishment.

Orthodontic maxillary expansion relies on intrinsic mid-palatal suture mechanobiology to induce guided osteogenesis, yet establishment of the mid-palatal suture within the continuous secondary palate and causes of maxillary insufficiency remain poorly understood. In contrast, advances in cranial suture research hold promise to improve surgical repair of prematurely fused cranial sutures in craniosynostosis to potentially restore the obliterated signaling environment and ensure continual success of the intervention. We hypothesized that mid-palatal suture establishment is governed by shared principles with calvarial sutures and involves functional linkage between expanding primary ossification centres with the midline mesenchyme. We characterized establishment of the mid-palatal suture from late embryonic to early postnatal timepoints. Suture establishment was visualized using histological techniques and multimodal transcriptomics. We identified that mid-palatal suture formation depends on a spatiotemporally controlled signalling milieu in which tendon-associated genes play a significant role. We mapped relationships between extracellular matrix-encoding gene expression, tenocyte markers, and novel suture patency candidate genes. We identified similar expression patterns in FaceBase-deposited scRNA-seq datasets from cranial sutures. These findings demonstrate shared biological principles for suture establishment, providing further avenues for future development and understanding of maxillofacial interventions.

FK506 binding protein 8 peptidylprolyl isomerase activity manages a late stage of cystic fibrosis transmembrane conductance regulator (CFTR) folding and stability.

Cystic fibrosis (CF) is caused by mutations in the apical chloride channel cystic fibrosis transmembrane conductance regulator (CFTR) with 90% of patients carrying at least one deletion of the F508 (ΔF508) allele. This mutant form of CFTR is characterized by a folding and trafficking defect that prevents exit from the endoplasmic reticulum. We previously reported that ΔF508 CFTR can be recovered in a complex with Hsp90 and its co-chaperones as an on-pathway folding intermediate, suggesting that Δ508 CF disease arises due to a failure of the proteostasis network (PN), which manages protein folding and degradation in the cell. We have now examined the role of FK506-binding protein 8 (FKBP8), a component of the CFTR interactome, during the biogenesis of wild-type and ΔF508 CFTR. FKBP8 is a member of the peptidylprolyl isomerase family that mediates the cis/trans interconversion of peptidyl prolyl bonds. Our results suggest that FKBP8 is a key PN factor required at a post-Hsp90 step in CFTR biogenesis. In addition, changes in its expression level or alteration of its activity by a peptidylprolyl isomerase inhibitor alter CFTR stability and transport. We propose that CF is caused by the sequential failure of the prevailing PN pathway to stabilize ΔF508-CFTR for endoplasmic reticulum export, a pathway that can be therapeutically managed.

Li-Fraumeni and Li-Fraumeni-like syndrome among children diagnosed with pediatric cancer in Southern Brazil.

BACKGROUND: Pediatric cancers are a feature in patients with Li-Fraumeni syndrome and its variant Li-Fraumeni-like syndrome (LFS/LFL). To the best of the authors' knowledge, TP53 germline mutations are currently the only molecular defect known to be associated with this disease. Recently, a specific germline mutation in this gene, p.R337H, has been reported at a high prevalence in Brazil. METHODS: The prevalence of LFS/LFL was investigated in children with cancer who were diagnosed with tumors on the LFS/LFL spectrum and in a small consecutive series of controls without cancer. The prevalence of the germline p.R337H mutation and of other germline TP53 mutations was investigated in a general group of children with cancer and exclusively in children fulfilling the clinical criteria for LFS/LFL, respectively. RESULTS: Among the 65 children without cancer, 1.5% had a family history of LFL whereas of the 292 children with cancer, 25.3% had a family history of LFL (P < .001). Screening for the p.R337H mutation identified 11 carriers (3.7%), 9 of whom were diagnosed with adrenocortical carcinomas (ACC) and 2 of whom were diagnosed with choroid plexus carcinomas. One of the ACC probands was homozygous mutant. The Brazilian founder haplotype and loss of heterozygosity at the p.R337H locus were present in all carriers. In addition, direct sequencing of the entire TP53 coding region and gene rearrangement analysis of probands fulfilling the criteria for LFL (Eeles 2 criteria, Birch and/or Chompret criteria) and who were negative for the p.R337H mutation revealed a DNA-binding domain pathogenic mutation, p.G245S, in 1 child. CONCLUSIONS: TP53 p.R337H testing should be offered to Brazilian children diagnosed with ACC and choroid plexus carcinoma. A significant percentage of children with cancer in southern Brazil fulfill the criteria for LFL and should be referred for genetic risk assessment.

Global enhancement of nuclear localization-dependent nuclear transport in transformed cells.

Fundamental to eukaryotic cell function, nucleocytoplasmic transport can be regulated at many levels, including through modulation of the importin/exportin (Imp/Exp) nuclear transport machinery itself. Although Imps/Exps are overexpressed in a number of transformed cell lines and patient tumor tissues, the efficiency of nucleocytoplasmic transport in transformed cell types compared with nontransformed cells has not been investigated. Here we use quantitative live cell imaging of 3 isogenic nontransformed/transformed cell pairs to show that nuclear accumulation of nuclear localization signal (NLS)-containing proteins, but not their NLS-mutated derivatives, is increased up to 7-fold in MCF10CA1h human epithelial breast carcinoma cells and in simian virus 40 (SV40)-transformed fibroblasts of human and monkey origin, compared with their nontransformed counterparts. The basis for this appears to be a significantly faster rate of nuclear import in transformed cell types, as revealed by analysis using fluorescence recovery after photobleaching for the human MCF10A/MCF10CA1h cell pair. Nuclear accumulation of NLS/nuclear export signal-containing (shuttling) proteins was also enhanced in transformed cell types, experiments using the nuclear export inhibitor leptomycin B demonstrating that efficient Exp-1-mediated nuclear export was not impaired in transformed compared with nontransformed cells. Enhanced nuclear import and export efficiencies were found to correlate with 2- to 4-fold higher expression of specific Imps/Exps in transformed cells, as indicated by quantitative Western blot analysis, with ectopic expression of Imps able to enhance NLS nuclear accumulation levels up to 5-fold in nontransformed MCF10A cells. The findings indicate that transformed cells possess altered nuclear transport properties, most likely due to the overexpression of Imps/Exps. The findings have important implications for the development of tumor-specific drug nanocarriers in anticancer therapy.

Global, but not chondrocyte-specific, MT1-MMP deficiency in adult mice causes inflammatory arthritis.

Membrane-type I metalloproteinase (MT1-MMP/MMP14) plays a key role in various pathophysiological processes, indicating an unaddressed need for a targeted therapeutic approach. However, mice genetically deficient in Mmp14 show severe defects in development and growth. To investigate the possibility of MT1-MMP inhibition as a safe treatment in adults, we generated global Mmp14 tamoxifen-induced conditional knockout (Mmp14kd) mice and found that MT1-MMP deficiency in adult mice resulted in severe inflammatory arthritis. Mmp14kd mice started to show noticeably swollen joints two weeks after tamoxifen administration, which progressed rapidly. Mmp14kd mice reached a humane endpoint 6 to 8 weeks after tamoxifen administration due to severe arthritis. Plasma TNF-α levels were also significantly increased in Mmp14kd mice. Detailed analysis revealed chondrocyte hypertrophy, synovial fibrosis, and subchondral bone remodeling in the joints of Mmp14kd mice. However, global conditional knockout of MT1-MMP in adult mice did not affect body weight, blood glucose, or plasma cholesterol and triglyceride levels. Furthermore, we observed substantial expression of MT1-MMP in the articular cartilage of patients with osteoarthritis. We then developed chondrocyte-specific Mmp14 tamoxifen-induced conditional knockout (Mmp14chkd) mice. Chondrocyte MT1-MMP deficiency in adult mice also caused apparent chondrocyte hypertrophy. However, Mmp14chkd mice did not exhibit synovial hyperplasia or noticeable arthritis, suggesting that chondrocyte MT1-MMP is not solely responsible for the onset of severe arthritis observed in Mmp14kd mice. Our findings also suggest that highly cell-type specific inhibition of MT1-MMP is required for its potential therapeutic use.

Integrated spatiotemporal transcriptomic resolution of embryonic palate osteogenesis.

The differentiation of osteoblasts and the subsequent formation of bone marks an important terminal phase in palate formation that leads to the separation of the oral and nasal cavities. While the developmental events that precede palatal osteogenesis are well explored, major gaps remain in our understanding of the molecular mechanisms that lead to the bony union of fusing palatal shelves. Herein, the timeline of osteogenic transcriptional programming is unveiled in the embryonic palate by way of integrated bulk, single-cell, and spatially resolved RNA-seq analyses. We define spatially restricted expression patterns of key marker genes, both regulatory and structural, that are differentially expressed during palatal fusion, including the identification of several novel genes ( Deup1, Dynlrb2, Lrrc23 ) spatially restricted in expression to the palate, providing a relevant framework for future studies that identify new candidate genes for cleft palate anomalies in humans as well as the timing of mammalian embryonic palatal osteogenesis.

Harnessing Bilayer Biomaterial Delivery of FTY720 as an Immunotherapy to Accelerate Oral Wound Healing.

Orofacial clefts are the most common craniofacial congenital anomaly. Following cleft palate repair, up to 60% of surgeries have wound healing complications leading to oronasal fistula (ONF), a persistent connection between the roof of the mouth and the nasal cavity. The current gold standard methods for ONF repair use human allograft tissues; however, these procedures have risks of graft infection and/or rejection, requiring surgical revisions. Immunoregenerative therapies present a novel alternative approach to harness the body's immune response and enhance the wound healing environment. We utilized a repurposed FDA-approved immunomodulatory drug, FTY720, to reduce the egress of lymphocytes and induce immune cell fate switching toward pro-regenerative phenotypes. Here, we engineered a bilayer biomaterial system using Tegaderm™, a liquid-impermeable wound dressing, to secure and control the delivery of FTY720- nanofiber scaffolds (FTY720-NF). We optimized release kinetics of the bilayer FTY720-NF to sustain drug release for up to 7d with safe, efficacious transdermal absorption and tissue biodistribution. Through comprehensive immunophenotyping, our results illustrate a pseudotime pro-regenerative state transition in recruited hybrid immune cells to the wound site. Additional histological assessments established a significant difference in full thickness ONF closure in mice on Day 7 following treatment with bilayer FTY720-NF, compared to controls. These findings demonstrate the utility of immunomodulatory strategies for oral wound healing, better positing the field to develop more efficacious treatment options for pediatric patients. One Sentence Summary: Local delivery of bilayer FTY720-nanofiber scaffolds in an ONF mouse model promotes complete wound closure through modulation of pro-regenerative immune and stromal cells.

Profiles of Wnt pathway gene expression during tooth morphogenesis.

Mouse and human genetic studies indicate key roles of the Wnt10a ligand in odontogenesis. Previous studies have identified effectors and regulators of the Wnt signaling pathway actively expressed during key stages of tooth morphogenesis. However, limitations in multiplexing and spatial resolution hindered a more comprehensive analysis of these signaling molecules. Here, profiling of transcriptomes using fluorescent multiplex in situ hybridization and single-cell RNA-sequencing (scRNA-seq) provide robust insight into the synchronized expression patterns of Wnt10a, Dkk1, and Sost simultaneously during tooth development. First, we identified Wnt10a transcripts restricted to the epithelium at the stage of tooth bud morphogenesis, contrasting that of Sost and Dkk1 localization to the dental mesenchyme. By embryonic day 15.5 (E15.5), a marked shift of Wnt10a expression from dental epithelium to mesenchyme was noted, while Sost and Dkk1 expression remained enriched in the mesenchyme. By postnatal day 0 (P0), co-localization patterns of Wnt10a, Dkk1, and Sost were observed in both terminally differentiating and secreting odontoblasts of molars and incisors. Interestingly, Wnt10a exhibited robust expression in fully differentiated ameloblasts at the developing cusp tip of both molars and incisors, an observation not previously noted in prior studies. At P7 and 14, after the mineralization of dentin and enamel, Wnt10a expression was limited to odontoblasts. Meanwhile, Wnt modulators showed reduced or absent signals in molars. In contrast, strong signals persisted in ameloblasts (for Wnt10a) and odontoblasts (for Wnt10a, Sost, and Dkk1) towards the proximal end of incisors, near the cervical loop. Our scRNA-seq analysis used CellChat to further contextualize Wnt pathway-mediated communication between cells by examining ligand-receptor interactions among different clusters. The co-localization pattern of Wnt10a, Dkk1, and Sost in both terminally differentiating and secreting odontoblasts of molars and incisors potentially signifies the crucial ligand-modulator interaction along the gradient of cytodifferentiation starting from each cusp tip towards the apical region. These data provide cell type-specific insight into the role of Wnt ligands and mediators during epithelial-mesenchymal interactions in odontogenesis.

Multimodal spatiotemporal transcriptomic resolution of embryonic palate osteogenesis.

The terminal differentiation of osteoblasts and subsequent formation of bone marks an important phase in palate development that leads to the separation of the oral and nasal cavities. While the morphogenetic events preceding palatal osteogenesis are well explored, major gaps remain in our understanding of the molecular mechanisms driving the formation of this bony union of the fusing palate. Through bulk, single-nucleus, and spatially resolved RNA-sequencing analyses of the developing secondary palate, we identify a shift in transcriptional programming between embryonic days 14.5 and 15.5 pinpointing the onset of osteogenesis. We define spatially restricted expression patterns of key osteogenic marker genes that are differentially expressed between these developmental timepoints. Finally, we identify genes in the palate highly expressed by palate nasal epithelial cells, also enriched within palatal osteogenic mesenchymal cells. This investigation provides a relevant framework to advance palate-specific diagnostic and therapeutic biomarker discovery.

Mechanism of microtubule-facilitated "fast track" nuclear import.

Although the microtubule (MT) cytoskeleton has been shown to facilitate nuclear import of specific cancer-regulatory proteins including p53, retinoblastoma protein, and parathyroid hormone-related protein (PTHrP), the MT association sequences (MTASs) responsible and the nature of the interplay between MT-dependent and conventional importin (IMP)-dependent nuclear translocation are unknown. Here we used site-directed mutagenesis, live cell imaging, and direct IMP and MT binding assays to map the MTAS of PTHrP for the first time, finding that it is within a short modular region (residues 82-108) that overlaps with the IMPß1-recognized nuclear localization signal (residues 66-108) of PTHrP. Importantly, fluorescence recovery after photobleaching experiments indicated that disruption of the MT network or mutation of the MTAS of PTHrP decreases the rate of nuclear import by 2-fold. Moreover, MTAS functions depend on mutual exclusivity of binding of PTHrP to MTs and IMPß1 such that, following MT-dependent trafficking toward the nucleus, perinuclear PTHrP can be displaced from MTs by IMPß1 prior to import into the nucleus. This is the first molecular definition of an MTAS that facilitates protein nuclear import as well as the first delineation of the mechanism whereby cargo is transferred directly from the cytoskeleton to the cellular nuclear import apparatus. The results have broad significance with respect to fundamental processes regulating cell physiology/transformation.

Pediatric high grade glioma of the spinal cord: results of the HIT-GBM database.

Little is known about pediatric spinal cord high grade gliomas (SCHGG) beyond their dismal prognosis. Here, we analyzed the HIT-GBM(®) database for the influence of surgical resection on survival. Between 1991 and 2010 the HIT-GBM group collected data from European children diagnosed with high grade glioma. Patients with the following inclusion criteria were analyzed in this study: astrocytic histology, WHO grade III or IV, age at diagnosis <18 years, and tumor localized to the spinal cord. 28 patients (mean age 11.28 years, 14 male) with primary SCHGG were identified. The tumor sizes were measured by the span across adjacent vertebrae and varied greatly (range: 1-20, median: 4). Histology was classified as WHO grade III in 15 and grade IV in 13 tumors. Of note, the four largest tumors identified were WHO grade III. Surgery was classified as complete resection (n = 6), subtotal resection (STR) (n = 7), partial resection (n = 12) or biopsy only (n = 3). 27 patients received chemotherapy, 22 of which also received radiation. With the mean follow-up time of 2.88 (SD ± 2.95) years, 14 patients were still alive resulting in a median overall survival of 2.5 years (SE ± 1.6). The positive prognostic indicators for overall survival were: age younger than 5 years (P = 0.047), WHO grade III (P = 0.046), absence of necrosis (P = 0.025) and gross total resection (GTR) (P = 0.012). The prognosis of SCHGG might not be as miserable as generally assumed. GTR is of benefit. Larger data sets and meta-analysis are necessary to identify patient sub-groups.

Histological Techniques for Sectioning Bones of the Vertebrate Craniofacial Skeleton.

Histochemical analysis is an indispensable technique in the field of biology used routinely to characterize pathologies of interest throughout the system. This chapter provides the craniofacial biologist with an introduction to tissue harvesting, embedding, and sectioning as well as a toolkit of useful stains for stromal/mesenchymal tissues including bone and cartilage. Techniques are tailored to decalcified, paraffin-embedded mouse tissue; however, these methods are applicable under a broad range of conditions.

Craniofacial sutures: Signaling centres integrating mechanosensation, cell signaling, and cell differentiation.

Cranial sutures are dynamic structures in which stem cell biology, bone formation, and mechanical forces interface, influencing the shape of the skull throughout development and beyond. Over the past decade, there has been significant progress in understanding mesenchymal stromal cell (MSC) differentiation in the context of suture development and genetic control of suture pathologies, such as craniosynostosis. More recently, the mechanosensory function of sutures and the influence of mechanical signals on craniofacial development have come to the forefront. There is currently a gap in understanding of how mechanical signals integrate with MSC differentiation and ossification to ensure appropriate bone development and mediate postnatal growth surrounding sutures. In this review, we discuss the role of mechanosensation in the context of cranial sutures, and how mechanical stimuli are converted to biochemical signals influencing bone growth, suture patency, and fusion through mediation of cell differentiation. We integrate key knowledge from other paradigms where mechanosensation forms a critical component, such as bone remodeling and orthodontic tooth movement. The current state of the field regarding genetic, cellular, and physiological mechanisms of mechanotransduction will be contextualized within suture biology.

Dual modes of rabies P-protein association with microtubules: a novel strategy to suppress the antiviral response.

Conventional nuclear import is independent of the cytoskeleton, but recent data have shown that the import of specific proteins can be either facilitated or inhibited by microtubules (MTs). Nuclear import of the P-protein from rabies virus involves a MT-facilitated mechanism, but here, we show that P-protein is unique in that it also undergoes MT-inhibited import, with the mode of MT-interaction being regulated by the oligomeric state of the P-protein. This is the first demonstration that a protein can utilise both MT-inhibited and MT-facilitated import mechanisms, and can switch between these different modes of MT interaction to regulate its nuclear trafficking. Importantly, we show that the P-protein exploits MT-dependent mechanisms to manipulate host cell processes by switching the import of the interferon-activated transcription factor STAT1 from a conventional to a MT-inhibited mechanism. This prevents STAT1 nuclear import and signalling in response to interferon, which is vital to the host innate antiviral response. This is the first report of MT involvement in the viral subversion of interferon signalling that is central to virus pathogenicity, and identifies novel targets for the development of antiviral drugs or attenuated viruses for vaccine applications.