KLF6 and STAT3 Co-Occupy Regulatory DNA and Functionally Synergize to Promote Axon Growth in CNS Neurons

The failure of axon regeneration in the CNS limits recovery from damage and disease. Members of the KLF family of transcription factors can exert both positive and negative effects on axon regeneration, but the underlying mechanisms are unclear. Here we show that forced expression of KLF6 promotes axon regeneration by corticospinal tract neurons in the injured spinal cord. RNA sequencing identified 454 genes whose expression changed upon forced KLF6 expression in vitro, including sub-networks that were highly enriched for functions relevant to axon extension including cytoskeleton remodeling, lipid synthesis, and bioenergetics. In addition, promoter analysis predicted a functional interaction between KLF6 and a second transcription factor, STAT3, and genome-wide footprinting using ATAC-Seq data confirmed frequent co-occupancy. Co-expression of the two factors yielded a synergistic elevation of neurite growth in vitro. These data clarify the transcriptional control of axon growth and point the way toward novel interventions to promote CNS regeneration

Long-term Follow up of Van Nes Rotationplasty for Congenital Proximal Focal Femoral Deficiency

Van Nes rotationplasty may be used for patients with congenital proximal focal femoral deficiency (PFFD). The lower limb is rotated to use the ankle and foot as a functional knee joint within a prosthesis. A small series of cases was investigated to determine the long-term outcome. At a mean of 21.5 years (11 to 45) after their rotationplasty, a total of 12 prosthetic patients completed the Short-Form (SF)-36, Faces Pain Scale-Revised, Harris hip score, Oswestry back pain score and Prosthetic Evaluation Questionnaires, as did 12 age- and gender-matched normal control participants. A physical examination and gait analysis, computerised dynamic posturography (CDP), and timed ‘Up & Go’ testing was also completed. Wilcoxon Signed rank test was used to compare each PFFD patient with a matched control participant with false discovery rate of 5%. There were no differences between the groups in overall health and well-being on the SF-36. Significant differences were seen in gait parameters in the PFFD group. Using CDP, the PFFD group had reduced symmetry in stance, and reduced end point and maximum excursions. Patients who had undergone Van Nes rotationplasty had a high level of function and quality of life at long-term follow-up, but presented with significant differences in gait and posture compared with the control group

Implications of Arm Restraint on Lower Extremity Kinetics During Gait

Background Literature indicates the importance of the upper extremities in providing stability and propulsion for the body during ambulation. However, the kinetic implications of upper extremity restraint during gait are not as well documented. Aim The objective of this study was to examine the effect of arm restraint (unilateral and bilateral) on lower extremity joint kinetics during walking. Methods Twenty-three healthy young participants were instrumented for three dimensional motion analysis, and tested in four randomly ordered upper extremity restraint conditions (unrestrained, bilateral restraint, right side restraint, and left side restraint). Temporal spatial parameters and gait/phase-specific lower extremity kinetics and kinematics were measured. For each restraint condition, pointwise differences from the unrestrained condition were compared using a two-way ANOVA model of restraint condition (“Condition”) and gait cycle phase (“Timing”). Results Decreases in walking speed and stride length were observed for all restraint conditions. Differences in kinetic demands were also noted, primarily at the hip and knee. Conclusion Upper extremity restraint in healthy young adults leads to significant changes in temporal-spatial parameters and proximal joint kinetics, most prominently during periods of load accommodation and balance

Metabolic responses of two pioneer wood decay fungi to diurnally cycling temperature

Decomposition of lignin-rich wood by fungi drives nutrient recycling in woodland ecosystems. Fluctuating abiotic conditions are known to promote the functioning of ecological communities and ecosystems. In the context of wood decay, fluctuating temperature increases decomposition rates. Metabolomics, in tandem with other ‘omics tools, can highlight the metabolic processes affected by experimental treatments, even in the absence of genome sequences and annotations. Globally, natural wood decay communities are dominated by the phylum Basidiomycota. We examined the metabolic responses of Mucidula mucida, a dominant constituent of pioneer communities in beech branches in British woodlands, and Exidia glandulosa, a stress-selected constituent of the same communities, in response to constant and diurnally cycling temperature. We applied untargeted metabolomics and proteomics to beech wood blocks, colonised by M. mucida or E. glandulosa and exposed to either diurnally cycling (mean 15 ± 10°C) or constant (15°C) temperature, in a fully factorial design. Metabolites and proteins linked to lignin breakdown, the citric acid cycle, pentose phosphate pathway, carbohydrate metabolism, fatty acid metabolism and protein biosynthesis and turnover were under-enriched in fluctuating, compared to stable temperatures, in the generalist M. mucida. Conversely, E. glandulosa showed little differential response to the experimental treatments. Synthesis. By demonstrating temperature-dependant metabolic signatures related to nutrient acquisition in a generalist wood decay fungus, we provide new insights into how abiotic conditions can affect community-mediated decomposition and carbon turnover in forests. We show that mechanisms underpinning important biogeochemical processes can be highlighted using untargeted metabolomics and proteomics in the absence of well-annotated genomes

Interdependence of primary metabolism and xenobiotic mitigation characterizes the proteome of 'Bjerkandera adusta' during wood decomposition

The aim of the current work was to identify key features of the fungal proteome involved in the active decay of beechwood blocks by the white rot fungus Bjerkandera adusta at 20°C and 24°C. A combination of protein and domain analyses ensured a high level of annotation, which revealed that while the variation in the proteins identified was high between replicates, there was a considerable degree of functional conservation between the two temperatures. Further analysis revealed differences in the pathways and processes employed by the fungus at the different temperatures, particularly in relation to nutrient acquisition and xenobiotic mitigation. Key features showing temperature-dependent variation in mechanisms for both lignocellulose decomposition and sugar utilization were found, alongside differences in the enzymes involved in mitigation against damage caused by toxic phenolic compounds and oxidative stress.IMPORTANCE This work was conducted using the wood decay fungus B. adusta, grown on solid wood blocks to closely mimic the natural environment, and gives greater insight into the proteome of an important environmental fungus during active decay. We show that a change in incubation temperature from 20°C to 24°C altered the protein profile. Proteomic studies in the field of white-rotting basidiomycetes have thus far been hampered by poor annotation of protein databases, with a large proportion of proteins simply with unknown function. This study was enhanced by extensive protein domain analysis, enabling a higher level of functional assignment and greater understanding of the proteome composition. This work revealed a strong interdependence of the primary process of nutrient acquisition and specialized metabolic processes for the detoxification of plant extractives and the phenolic breakdown products of lignocellulose

The whiff of decay: Linking volatile production and extracellular enzymes to outcomes of fungal interactions at different temperatures

The terrestrial carbon cycle is largely driven by photosynthetic plants and decomposer organisms that process biomass to CO2. In forest ecosystems, the decomposers are predominantly wood decay fungi, and the response of community structure and activity to increasing global temperatures is likely critical to forest biogeochemical processes. Metabolic products can drive community structure and substrate utilisation, and the role of volatile organic compounds (VOCs), as well as extracellular enzymes, are of particular interest. Pair-wise interactions of a community of basidiomycetes were made under 3 different microclimate conditions that mimic fluctuations in local climate conditions, and the outcome of interactions was assessed in terms of: (1) which fungus won the confrontation or whether it was a draw (deadlock); (2) the production of volatile organic compounds (VOCs) and enzyme activities; and (3) the rate of decomposition. While substrate utilisation and exploitation in terms of decomposition was not affected, community response to changing temperature was underpinned by altered outcomes of interactions and changes to territory occupation, which were reflected by changes in VOC production and extracellular enzyme activity. This study underlines the importance of understanding the impact of community structure on carbon cycling in forest ecosystems under a changing climate

Percutaneous & Mini Invasive Achilles tendon repair

Rupture of the Achilles tendon is a considerable cause of morbidity with reduced function following injury. Recent studies have shown little difference in outcome between the techniques of open and non-operative treatment using an early active rehabilitation programme. Meta-analyses have shown that non-operative management has increased risk of re-rupture whereas surgical intervention has risks of complications related to the wound and iatrogenic nerve injury. Minimally invasive surgery has been adopted as a way of reducing infections rates and wound breakdown however avoiding iatrogenic nerve injury must be considered. We discuss the techniques and outcomes of percutaneous and minimally invasive repairs of the Achilles tendon

The Paleozoic Origin of Enzymatic Lignin Decomposition Reconstructed from 31 Fungal Genomes

Wood is a major pool of organic carbon that is highly resistant to decay, owing largely to the presence of lignin. The only organisms capable of substantial lignin decay are white rot fungi in the Agaricomycetes, which also contains non–lignin-degrading brown rot and ectomycorrhizal species. Comparative analyses of 31 fungal genomes (12 generated for this study) suggest that lignin-degrading peroxidases expanded in the lineage leading to the ancestor of the Agaricomycetes, which is reconstructed as a white rot species, and then contracted in parallel lineages leading to brown rot and mycorrhizal species. Molecular clock analyses suggest that the origin of lignin degradation might have coincided with the sharp decrease in the rate of organic carbon burial around the end of the Carboniferous period

FISHing in fungi: Visualisation of mushroom virus X in the mycelium of Agaricus bisporus by fluorescence in situ hybridisation

Agaricus bisporus is a commercial mushroom crop susceptible to a disease caused by a complex of viruses known collectively as mushroom virus X (MVX). Symptoms of MVX include bare patches and mushroom cap discolouration (browning) in the fruiting bodies, phenotypes associated with the viruses AbV6 and AbV16, respectively. Limited understanding exists of the localisation and mobilisation of these viruses within the mycelium of A. bisporus. To this end, a non-destructive fluorescence in situ hybridisation (FISH) method was developed for in situ targeting of AbV6 and AbV16 in A. bisporus mycelium. An MVX strain associated with the bare patch disease phenotype revealed predominantly high signal towards the growing edges of cultures when probed for AbV6, with a ‘halo-effect’ of high signal intensity around putative vacuoles. An MVX strain associated with the browning disease phenotype showed high signal intensities within reticulating networks of hyphae in a highly compartmentalised manner when probed for AbV16. Localisation of the two viruses in MVX-infected cultures appears independent, as both viruses were found in completely discrete areas of the mycelium in differential patterns. FISH detected low level presence of the two viruses, AbV6 and AbV16 in a number of cultures which had tested negative for the viruses by RT-PCR. This suggests that FISH may be more sensitive at detecting viruses at low levels than molecular methods. This study demonstrates that FISH is a powerful tool in the field of mycovirology