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New medicines are urgently required to treat the fatal neuromuscular disease, Duchenne muscular dystrophy (DMD). DMD involves progressive muscle damage and weakness, which are preceded by oxidative stress, inflammation, and mitochondrial dysfunction. Dimethyl fumarate (DMF) is a potent small molecule nuclear erythroid 2-related factor 2 (Nrf2) activator with current clinical utility in the treatment of multiple sclerosis and psoriasis. Pharmaceutical targeting of Nrf2 by DMF has strong translational potential for DMD, given it: (1) promotes antioxidant defence systems; (2) has a potent immuno-modulatory profile; and (3) can be rapidly re-purposed into clinical care strategies for DMD patients. Here, we tested two weeks of daily 100mg/kg DMF versus 5mg/kg standard care prednisone (PRED) treatment during the peak muscle degeneration period in juvenile mdx mice, the gold standard murine DMD model. Both drugs modulated seed genes driving the DMD disease program and improved muscle force production in fast-twitch muscle. However, only DMF showed pro-mitochondrial effects that protected contracting muscles from fatigue, improved histopathology and augmented clinically compatible muscle function tests. In contrast, PRED treatment stunted mouse growth, worsened histopathology and modulated many normally expressed inflammatory and extracellular matrix (ECM) genes consistent with pan immunosuppression. These findings suggest DMF could be a more selective modulator of the DMD disease program with better efficacy and fewer side effects than standard care PRED therapy warranting follow-up studies to progress clinical translation.

Duchenne muscular dystrophy (DMD) is a severe childhood disease characterised by progressive muscle wasting caused by widespread myofibre necrosis. Implicated in the pathology of DMD is oxidative stress, caused by excessive generation of reactive oxygen and nitrogen species (RONS). One consequence of RONS exposure is post-translational oxidative modifications to proteins, which can cause loss of protein function. This study used the dystrophic mdx mouse model for DMD to visualise the precise location of different oxidative modifications to proteins in dystrophic muscles, including both reversible (protein thiol oxidation and s-nitrosylation) and irreversible (carbonylation and dityrosine formation) oxidation at various stages of dystrophic muscle necrosis and regeneration. High levels of protein oxidation were observed in mdx myofibres undergoing degeneration and immune cell infiltration (myonecrosis). Since irreversible protein oxidation, especially dityrosine formation, was only colocalised to areas of myonecrosis, we suggest that this specific measurement could be a useful biomarker of myonecrosis. To test this we quantified dityrosines in muscle homogenates; this analysis showed significantly higher levels of dityrosines in mdx (compared with control normal) mice aged 23 days, an age when acute onset of extensive myonecrosis occurs in mdx muscles. These results indicate a major localised role of immune cells in RONS generation in dystrophic muscle, and strongly support a role for protein oxidation in myonecrosis and associated dystropathology. Consequently, the measurement of protein oxidation (specifically dityrosines) in dystrophic muscles may be a useful biomarker for indirectly quantifying myonecrosis in research studies using mdx mice and other animal models for DMD.

Introduction: In order to better understand the physiological and pathophysiological roles of reactive oxygen species (ROS), multiple blood and urine biomarkers of oxidative stress have been develo...

Duchenne muscular dystrophy (DMD) is a fatal X-linked genetic disease characterized by progressive loss of skeletal muscle. The mechanisms underlying the DMD pathology likely involve the complex interaction between reactive oxygen species (ROS) impaired Ca2+ handling and chronic inflammation, characterized by the presence of immune cells such as neutrophils. Hypochlorous acid (HOCl) is a highly reactive form of ROS produced endogenously via the actions of myeloperoxidase, an enzyme secreted by neutrophils. Myeloperoxidase activity is significantly elevated in dystrophic muscle. This study aimed to determine the effect of HOCl exposure on excitation–contraction coupling and its potential contribution to the dystrophic pathology. Isolated extensor digitorum longus (EDL) muscles and single fibers from C57 (wild type) and mdx (dystrophic) mice were used to investigate the effects of HOCl on whole muscle function, intracellular Ca2+ handling, and myofilament force production. HOCl exposure significantly decreased maximum specific force in isolated EDL muscles by 26% and 49%, respectively, in C57 and mdx mice (P < 0.0001). In single interosseous fibers, HOCl exposure significantly increased resting intracellular Ca2+ concentration by ∼17–19% (P < 0.05) and decreased the amplitude of electrically induced Ca2+ transients by ∼45% and 50%, respectively, in C57 and mdx fibers (C57, P < 0.05; mdx, P < 0.01). These effects of HOCl on resting Ca2+ could be blocked via application of tetracaine (ryanodine receptor blocker) or Gd3+ (stretch-activated channel blocker; C57, P < 0.01; mdx, P < 0.01 for both). The effect of HOCl on Ca2+ transient amplitude was significantly reduced by Gd3+ (C57, P < 0.05; mdx, P < 0.01). In chemically skinned EDL fibers, HOCl exposure decreased maximum Ca2+-activated force by ∼40% in both C57 and mdx fibers (P < 0.001). These results indicate that HOCl potently affects excitation–contraction coupling via impaired Ca2+ handling and myofilament force production. Hence, HOCl potentially links the chronic inflammation, oxidative stress, and impaired Ca2+ handling that underlies the dystrophic pathology.

Duchenne muscular dystrophy (DMD) is a severe X-linked muscle wasting disease with no cure. While the precise mechanisms of progressive dystropathology remain unclear, oxidative stress caused by excessive generation of oxidants is strongly implicated. Blood biomarkers that could track oxidant levels in tissues would be valuable to measure the effectiveness of clinical treatments for DMD, our research has focused on developing such biomarkers. One target of oxidants that has the potential to be harnessed as a clinical biomarker is the thiol side chain of cysteine 34 (Cys34) of the blood protein albumin. This study using the mdx mouse model of DMD shows that in plasma, albumin Cys34 undergoes thiol oxidation and these changes correlate with levels of protein thiol oxidation and damage of the dystrophic muscles. A comparison with the commonly used biomarker protein carbonylation, confirmed that albumin thiol oxidation is the more sensitive plasma biomarker of oxidative stress occurring in muscle tissue. We show that plasma albumin oxidation reflects muscle dystropathology, as increased after exercise and decreased after taurine treatment of mdx mice. These data support the use of albumin thiol oxidation as a blood biomarker of dystropathology to assist with advancing clinical development of therapies for DMD.

Isotope-coded affinity tags (ICATs) are valuable tools for mass spectrometry-based quantitative proteomics, in particular, for comparison of protein (cysteine-residue) thiol oxidation state in normal, stressed, and diseased tissue. However, the iodoacetamido electrophile used in most commercial ICATs suffers from poor thiol-selectivity and modest rates of adduct formation, which can lead to spurious results. Hence, we designed and synthesized three ICATs containing thiol-selective N-alkylmaleimide electrophiles (isotope-coded maleimide affinity tags = ICMATs) and assessed these as mass spectrometry probes for ratiometric analysis of lysozyme and muscle proteomes. Two ICMAT pairs containing butylene/D8-butylene linkers were effective MS probes, but not ideal for typical proteomics workflows, because peptides bearing these tags frequently did not coelute with HPLC. A switch to a phenylene/13C6-phenylene linker solved this issue without compromising the efficiency of adduct formation.

Duchenne muscular dystrophy (DMD) is a lethal, X-chromosome linked muscle-wasting disease affecting about 1 in 3500-6000 boys worldwide. Myofibre necrosis and subsequent loss of muscle mass are due to several molecular sequelae, such as inflammation and oxidative stress. We have recently shown increased neutrophils, highly reactive oxidant hypochlorous acid (HOCl) generation by myeloperoxidase (MPO), and associated oxidative stress in muscle from the GRMD dog and mdx mouse models for DMD. These findings have led us to hypothesise that generation of HOCl by myeloperoxidase released from neutrophils has a significant role in dystropathology. Since access to muscle from DMD patients is limited, the aim of this study was to develop methods to study this pathway in urine. Using immunoblotting to measure markers of protein oxidation, we show increased labelling of proteins with antibodies to dinitrophenylhydrazine (DNP, oxidative damage) and DiBrY (halogenation by reactive oxidants from myeloperoxidase) in GRMD and mdx urine. A strong positive correlation was observed between DiBrY labelling in dog urine and muscle. A strong positive correlation was also observed when comparing DNP and DiBrY labelling (in muscle and urine) to markers of dystropathology (plasma creatine kinase) and neutrophil presence (muscle MPO). Our results indicate the presence of neutrophil mediated oxidative stress in both models, and suggest that urine is a suitable bio-fluid for the measurement of such biomarkers. These methods could be employed in future studies into the role of neutrophil mediated oxidative stress in DMD and other inflammatory pathologies.

Duchenne muscular dystrophy (DMD) is a lethal genetic muscle wasting disorder, which currently has no cure. Supplementation with the drug taurine has been shown to offer therapeutic benefit in the mdx model for DMD, however the mechanism by which taurine protects dystrophic muscle is not fully understood. Mdx muscle is deficient in taurine, however it is not known if this deficiency occurs in the extracellular space, in other cells present in the tissue (such as immune cells) or in the myofibre itself. Likewise, the tissue location of taurine enrichment in taurine treated mdx muscle is not known. In this study we applied X-ray absorption near edge spectroscopy (XANES) at the sulfur K-edge in an imaging format to determine taurine distribution in muscle tissue. XANES is the only technique currently capable of imaging taurine directly in muscle tissue, at a spatial resolution approaching myocyte cell size (20-50 μm). Using a multi-modal approach of XANES imaging and histology on the same tissue sections, we show that in mdx muscle, it is the myofibres that are deficient in taurine, and taurine supplementation ameliorates this deficiency. Increasing the taurine content of mdx myofibres was associated with a decrease in myofibre damage (as shown by the percentage of intact myofibres) and inflammation. These data will help drive future studies to better elucidate the molecular mechanisms through which taurine protects dystrophic muscle; they also support the continued investigation of taurine as a therapeutic intervention for DMD.

Duchenne muscular dystrophy (DMD) is a lethal, X-linked disease that causes severe loss of muscle mass and function in young children. Promising therapies for DMD are being developed, but the long lead times required when using clinical outcome measures are hindering progress. This progress would be facilitated by robust molecular biomarkers in biofluids, such as blood and urine, which could be used to monitor disease progression and severity, as well as to determine optimal drug dosing before a full clinical trial. Many candidate DMD biomarkers have been identified, but there have been few follow-up studies to validate them. This Review describes the promising biomarkers for dystrophic muscle that have been identified in muscle, mainly using animal models. We strongly focus on myonecrosis and the associated inflammation and oxidative stress in DMD muscle, as the lack of dystrophin causes repeated bouts of myonecrosis, which are the key events that initiate the resultant severe dystropathology. We discuss the early events of intrinsic myonecrosis, along with early regeneration in the context of histological and other measures that are used to quantify its incidence. Molecular biomarkers linked to the closely associated events of inflammation and oxidative damage are discussed, with a focus on research related to protein thiol oxidation and to neutrophils. We summarise data linked to myonecrosis in muscle, blood and urine of dystrophic animal species, and discuss the challenge of translating such biomarkers to the clinic for DMD patients, especially to enhance the success of clinical trials., Summary: This Review discusses biomarkers in blood and urine linked to myonecrosis, inflammation and oxidative stress, to enhance development of therapies for DMD, and the challenges to be overcome for clinical translation.

Assessment is a central component of course curriculums and is used to certify student learning, but it can also be used as a tool to improve teaching and learning. Many laboratory courses are structured such that there is only a grade for a particular laboratory, which limits the insights that can be gained in student learning. We developed a laboratory program that incorporates assessments designed to probe student understanding of different components of the individual modules making up the program. The challenge was to analyze and present grades from these assessment tasks in a format that was readily interpretable by academics. We show that a simplified synthesis of grade distributions (grade distribution digests) provides sufficient information to make decisions about changes in course components. The main feature of the digests is its data visualization approach, where student grades for individual laboratory practicals, individual assessment tasks or individual assessment items are graphically presented as an overall average grade, an average top quartile grade and an average bottom quartile grade, and relative averages across all assessments. This ability to visualize student grades in variety of contexts enables academics with many other demands on their time (e.g. research and administration) to more efficiently identify ways to improve teaching delivery and learning outcomes. Examples are presented of the use of such data to identify and improve deficiencies in both student skills and teaching practice, resulting in improved learning outcomes. © 2017 by The International Union of Biochemistry and Molecular Biology, 46(2):130-140, 2018.

Duchenne Muscular Dystrophy (DMD) is a fatal X-linked muscle wasting disease characterised by severe muscle weakness, necrosis, inflammation and oxidative stress. The antioxidant N-acetylcysteine (NAC) has been proposed as a potential therapeutic intervention for DMD boys. We investigated the capacity of NAC to improve dystrophic muscle function in the mdx mouse model of DMD. Young (6 w old) mdx and non-dystrophic C57 mice receiving 2% NAC in drinking water for 6 w were compared with untreated mice. Grip strength and body weight were measured weekly, before the 12 w old mice were anaesthetized and extensor digitorum longus (EDL) muscles excised for functional analysis and tissues sampled for biochemical analyses. Compared to untreated mice, the mean (SD) normalised grip strength was significantly greater in NAC treated mdx [3.13 (0.58) cf. 4.87 (0.78) g bw−1; P

Oxidative stress, caused by reactive oxygen and nitrogen species (RONS), is important in the pathophysiology of many diseases. A key target of RONS is the thiol group of protein cysteine residues. Because thiol oxidation can affect protein function, mechanistic information about how oxidative stress affects tissue function can be ascertained by identifying oxidized proteins. The probes used must be specific and sensitive, such as maleimides for the alkylation of reduced cysteine thiols. However, we find that maleimide-alkylated peptides (MAPs) are oxidized and hydrolyzed under sample preparation conditions common for proteomic studies. This can result in up to 90% of the MAP signal being converted to oxidized or hydrolyzed MAPs, decreasing the sensitivity of the analysis. A substantial portion of these modifications were accounted for by Coomassie "blue silver" staining (∼14%) of gels and proteolytic digestion buffers (∼20%). More than 40% of the MAP signal can be retained with the use of thioglycolic acid during gel electrophoresis, trichloroethanol-UV protein visualization in gels, and proteolytic digestion buffer of pH 7.0 TRIS. This work demonstrates that it is possible to decrease modifications to MAPs through changes to the sample preparation workflow, enhancing the potential usefulness of maleimide in identifying oxidized peptides.

Duchenne Muscular Dystrophy (DMD) is a fatal skeletal muscle wasting disease presenting with excessive myofibre necrosis and increased inflammation and oxidative stress. In the mdx mouse model of DMD, homeostasis of the amino acid taurine is altered, and taurine administration drastically decreases muscle necrosis, dystropathology, inflammation and protein thiol oxidation. Since the severe pathology of the Golden Retriever Muscular Dystrophy (GRMD) dog model more closely resembles the human DMD condition, we aimed to assess the generation of oxidants by inflammatory cells and taurine metabolism in this species. In muscles of 8 month GRMD dogs there was an increase in the content of neutrophils and macrophages, and an associated increase in elevated myeloperoxidase, a protein secreted by neutrophils that catalyses production of the highly reactive hypochlorous acid (HOCl). There was also increased chlorination of tyrosines, a marker of HOCl generation, increased thiol oxidation of many proteins and irreversible oxidative protein damage. Taurine, which functions as an antioxidant by trapping HOCl, was reduced in GRMD plasma; however taurine was increased in GRMD muscle tissue, potentially due to increased muscle taurine transport and synthesis. These data indicate a role for HOCl generated by neutrophils in the severe dystropathology of GRMD dogs, which may be exacerbated by decreased availability of taurine in the blood. These novel data support continued research into the precise roles of oxidative stress and taurine in DMD and emphasise the value of the GRMD dogs as a suitable pre-clinical model for testing taurine as a therapeutic intervention for DMD boys., Graphical abstract fx1, Highlights • We investigated oxidative stress in muscle from the GRMD dog model of DMD. • Excess neutrophils were associated with hypochlorous acid generation in GRMD muscle. • GRMD muscle exhibited oxidative damage to proteins, and protein thiol oxidation. • These data imply a role of immune cell generated oxidative stress in GRMD pathology.

A new laboratory practical system is described which is comprised of a number of laboratory practical modules, each based around a particular technique or set of techniques, related to the theory part of the course but not designed to be dependent on it. Each module comprises an online recorded pre-lab lecture, the laboratory practical itself and a post-lab session in which students make oral presentations on different aspects of the practical. Each part of the module is assessed with the aim of providing rapid feedback to staff and students. Each laboratory practical is the responsibility of a single staff member and through this "ownership," continual review and updating is promoted. Examples of changes made by staff to modules as a result of student feedback are detailed. A survey of students who had experienced both the old-style laboratory course and the new one provided evidence of increased satisfaction with the new program. The assessment of acquired shills in the new program showed that it was much more effective than the old course. © 2016 by The International Union of Biochemistry and Molecular Biology, 44:276-287, 2016.

Key points Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disease associated with increased inflammation, oxidative stress and myofibre necrosis. Cysteine precursor antioxidants such as N-acetyl cysteine (NAC) and l-2-oxothiazolidine-4-carboxylate (OTC) reduce dystropathology in the mdx mouse model for DMD, and we propose this is via increased synthesis of the amino acid taurine. We compared the capacity of OTC and taurine treatment to increase taurine content of mdx muscle, as well as effects on in vivo and ex vivo muscle function, inflammation and oxidative stress. Both treatments increased taurine in muscles, and improved many aspects of muscle function and reduced inflammation. Taurine treatment also reduced protein thiol oxidation and was overall more effective, as OTC treatment reduced body and muscle weight, suggesting some adverse effects of this drug. These data suggest that increasing dietary taurine is a better candidate for a therapeutic intervention for DMD. Abstract Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disease for which there is no widely available cure. Whilst the mechanism of loss of muscle function in DMD and the mdx mouse model are not fully understood, disruptions in intracellular calcium homeostasis, inflammation and oxidative stress are implicated. We have shown that protein thiol oxidation is increased in mdx muscle, and that the indirect thiol antioxidant l-2-oxothiazolidine-4-carboxylate (OTC), which increases cysteine availability, decreases pathology and increases in vivo strength. We propose that the protective effects of OTC are a consequence of conversion of cysteine to taurine, which has itself been shown to be beneficial to mdx pathology. This study compares the efficacy of taurine with OTC in decreasing dystropathology in mdx mice by measuring in vivo and ex vivo contractile function and measurements of inflammation and protein thiol oxidation. Increasing the taurine content of mdx muscle improved both in vivo and ex vivo muscle strength and function, potentially via anti-inflammatory and antioxidant effects of taurine. OTC treatment increased taurine synthesis in the liver and taurine content of mdx muscle, improved muscle function and decreased inflammation. However, OTC was less effective than taurine treatment, with OTC also decreasing body and EDL muscle weights, suggesting that OTC had some detrimental effects. These data support continued research into the use of taurine as a therapeutic intervention for DMD, and suggest that increasing dietary taurine is the better strategy for increasing taurine content and decreasing severity of dystropathology.

Oxidative stress, caused by excess reactive oxygen species (ROS), has been hypothesized to cause or exacerbate skeletal muscle wasting in a number of diseases and chronic conditions. ROS, such as hydrogen peroxide, have the potential to affect signal transduction pathways such as the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3 K)/Akt pathway that regulates protein synthesis. Previous studies have found contradictory outcomes for the effect of ROS on the PI3K/Akt signaling pathway, where oxidative stress can either enhance or inhibit Akt phosphorylation. The apparent contradictions could reflect differences in experimental cell types or types of ROS treatments. We replicate both effects in myotubes of cultured skeletal muscle C2C12 cells, and show that increased oxidative stress can either inhibit or enhance Akt phosphorylation. This differential response could be explained: thiol oxidation of Akt, but not the phosphatases PTEN or PP2A, caused a decline in Akt phosphorylation; whereas the thiol oxidation of Akt, PTEN and PP2A increased Akt phosphorylation. These observations indicate that a more complete understanding of the effects of oxidative stress on a signal transduction pathway comes not only from identifying the proteins susceptible to thiol oxidation, but also their relative sensitivity to ROS.

Gli transcription factors of the Hedgehog (Hh) pathway have been reported to be drivers of malignant mesothelioma (MMe) cell survival. The Gli inhibitor GANT61 induces apoptosis in various cancer cell models, and has been associated directly with Gli inhibition. However various chemotherapeutics can induce cell death through generation of reactive oxygen species (ROS) but whether ROS mediates GANT61-induced apoptosis is unknown. In this study human MMe cells were treated with GANT61 and the mechanisms regulating cell death investigated. Exposure of MMe cells to GANT61 led to G1 phase arrest and apoptosis, which involved ROS but not its purported targets, GLI1 or GLI2. GANT61 triggered ROS generation and quenching of ROS protected MMe cells from GANT61-induced apoptosis. Furthermore, we demonstrated that mitochondria are important in mediating GANT61 effects: (1) ROS production and apoptosis were blocked by mitochondrial inhibitor rotenone; (2) GANT61 promoted superoxide formation in mitochondria; and (3) mitochondrial DNA-deficient LO68 cells failed to induce superoxide, and were more resistant to apoptosis induced by GANT61 than wild-type cells. Our data demonstrate for the first time that GANT61 induces apoptosis by promoting mitochondrial superoxide generation independent of Gli inhibition, and highlights the therapeutic potential of mitochondrial ROS-mediated anticancer drugs in MMe.

Purpose This study aimed to examine the effect of taurine ingestion on maximal voluntary muscle torque and power in trained male athletes with different caffeine habits. Methods Fourteen male athletes 21.8 ± 2.5 yr old were separated into caffeine and noncaffeine consumers to control for the effect of caffeine withdrawal on muscle function. On separate occasions, participants performed four isokinetic or three maximal isometric knee extensions with and without taurine (40 mg·kg−1 body mass) after a double-blind, counterbalanced design. Muscle contractile performances were compared between the first sets as well as between the sets where these variables scored best. Results In response to isokinetic contraction, taurine treatment in the noncaffeine consumers resulted in a significant fall in first (−16.1%; P = 0.013) and best peak torque (−5.0%; P = 0.016) as well as in first (−17.7%; P = 0.015) and best power output (−8.0%; P = 0.008). In the caffeine consumers deprived of caffeine, taurine intake improved best power (5.2%; P = 0.045). With respect to the isometric variables, there was a significant decrease in the first (−5.1%; P = 0.002) and best peak torque (−4.3%; P = 0.032) in the noncaffeine group, but no effect in the group of caffeine consumers deprived of caffeine. Taurine ingestion increased blood taurine levels but had no effect on plasma amino acid levels. Conclusions Taurine ingestion is detrimental to maximal voluntary muscle power and both maximal isokinetic and isometric peak torque in noncaffeine consumers, whereas taurine ingestion in caffeine-deprived caffeine consumers improves maximal voluntary muscle power but has no effect on other aspects of contractile performance.

Duchenne Muscular Dystrophy (DMD) is a fatal muscle wasting disease manifested in young boys, for which there is no current cure. We have shown that the amino acid taurine is safe and effective at preventing dystropathology in the mdx mouse model for DMD. This study aimed to establish if treating growing mdx mice with a higher dose of taurine was more effective at improving strength and reducing inflammation and oxidative stress. Mice were treated with a dose of taurine estimated to be 16 g/kg/day, in drinking water from 1-6 weeks of age, after which in vivo and ex vivo muscle strength was assessed, as were measures of inflammation, oxidative stress and taurine metabolism. While the dose did decrease inflammation and protein oxidation in dystrophic muscles, there was no improvement in muscle strength (in contrast with benefits observed with the lower dose) and growth of the young mice was significantly restricted. We present novel data that a high taurine dose increases the cysteine content of both mdx liver and plasma, a possible result of down regulation of the taurine synthesis pathway in the liver (which functions to dispose of excess cysteine, which is toxic). These data caution that a high dose of taurine can have adverse effects and may be less efficacious than lower taurine doses. Therefore, monitoring of taurine dosage needs to be considered in future pre-clinical trials, in anticipation of using taurine as a clinical therapy for growing DMD boys (and other conditions).

Assessment is a central component of course curriculums and is used to certify student learning, but it can also be used as a tool to improve teaching and learning. Many laboratory courses are structured such that there is only a grade for a particular laboratory, which limits the insights that can be gained in student learning. We developed a laboratory program that incorporates assessments designed to probe student understanding of different components of the individual modules making up the program. The challenge was to analyze and present grades from these assessment tasks in a format that was readily interpretable by academics. We show that a simplified synthesis of grade distributions (grade distribution digests) provides sufficient information to make decisions about changes in course components. The main feature of the digests is its data visualization approach, where student grades for individual laboratory practicals, individual assessment tasks or individual assessment items are graphically presented as an overall average grade, an average top quartile grade and an average bottom quartile grade, and relative averages across all assessments. This ability to visualize student grades in variety of contexts enables academics with many other demands on their time (e.g. research and administration) to more efficiently identify ways to improve teaching delivery and learning outcomes. Examples are presented of the use of such data to identify and improve deficiencies in both student skills and teaching practice, resulting in improved learning outcomes. © 2017 by The International Union of Biochemistry and Molecular Biology, 46(2):130-140, 2018.

Background: The mdx mouse model for the fatal muscle wasting disease Duchenne Muscular Dystrophy (DMD) shows a very mild pathology once growth has ceased, with low levels of myofibre necrosis in adults. However, from about 3 weeks of post-natal age, muscles of juvenile mdx mice undergo an acute bout of severe necrosis and inflammation: this subsequently decreases and stabilises to lower adult levels by about 6 weeks of age. Prior to the onset of this severe dystropathology, we have shown that mdx mice are deficient in the amino acid taurine (potentially due to weaning), and we propose that this exacerbates myofibre necrosis and inflammation in juvenile mdx mice. Objectives: The purpose of this study was to increase taurine availability to pre-weaned juvenile mdx mice (from 14 days of age), to evaluate the impact on levels of myofibre necrosis and inflammation (at 22 days) during the acute period of severe dystropathology. Results: Untreated 22 day old mdx muscle was not deficient in taurine, with similar levels to normal C57 control muscle. However taurine treatment, which increased the taurine content of young dystrophic muscle (by 40%), greatly reduced myofibre necrosis (by 75%) and prevented significant increases in 3 markers of inflammation. Conclusion: Taurine was very effective at preventing the acute phase of muscle damage that normally results in myofibre necrosis and inflammation in juvenile mdx mice, supporting continued research into the use of taurine as a therapeutic intervention for protecting growing muscles of young DMD boys

BACKGROUND The mdx mouse model for the fatal muscle wasting disease Duchenne Muscular Dystrophy (DMD) shows a very mild pathology once growth has ceased, with low levels of myofibre necrosis in adults. However, from about 3 weeks of post-natal age, muscles of juvenile mdx mice undergo an acute bout of severe necrosis and inflammation: this subsequently decreases and stabilises to lower adult levels by about 6 weeks of age. Prior to the onset of this severe dystropathology, we have shown that mdx mice are deficient in the amino acid taurine (potentially due to weaning), and we propose that this exacerbates myofibre necrosis and inflammation in juvenile mdx mice. OBJECTIVES The purpose of this study was to increase taurine availability to pre-weaned juvenile mdx mice (from 14 days of age), to evaluate the impact on levels of myofibre necrosis and inflammation (at 22 days) during the acute period of severe dystropathology. RESULTS Untreated 22 day old mdx muscle was not deficient in taurine, with similar levels to normal C57 control muscle. However taurine treatment, which increased the taurine content of young dystrophic muscle (by 40%), greatly reduced myofibre necrosis (by 75%) and prevented significant increases in 3 markers of inflammation. CONCLUSION Taurine was very effective at preventing the acute phase of muscle damage that normally results in myofibre necrosis and inflammation in juvenile mdx mice, supporting continued research into the use of taurine as a therapeutic intervention for protecting growing muscles of young DMD boys.

STAT1 plays a central role in the immune system, in which it mediates signaling induced by different cytokines, including type I (α/β) and type II Interferon (IFN), and regulates expression of genes involved in many physiological processes, including antiviral and antibacterial defense, immune tolerance, suppression of cell proliferation, and induction of apoptosis. Dysregulation or mutation of STAT1 causes life threatening conditions resulting from inefficient defense against pathogens, autoimmunity or cancer development. Single nucleotide polymorphisms of STAT1 Cys residues are associated with chronic mucocutaneous candidiasis disease (CMCD), suggesting a role of Cys in the capacity of STAT1 to drive an appropriate anti-pathogen response. Regulation of STAT1 activity through different post-translational modifications is well-characterized. However, the role of Reactive Oxygen species (ROS) and Cys reversible oxidative post-translational modifications (ox-PTMs) on STAT1 function remained to be investigated. Using maleimide-derivative switch methods to label Cys ox-PTMs, we found that Diamide, a thiol-oxidizing agent, and the myeloperoxidase-generated HOCl induce ox-PTMs of STAT1 Cys in epithelial cells (A549), monocytes (THP-1) and ectopically expressed STAT1 in STAT1 deficient fibroblasts (U3A). Analysis of Cys/Ala (C/A) mutants of STAT1 in response to IFNγ and IFNβ revealed gain of function phenotype of mutations in two different functional domains of STAT1. Altogether, our data supports a model in which previously unrecognized ox-PTMs of STAT1 Cys residues are essential to dampen STAT1 activity. Current studies are aimed at further characterizing the specific Cys ox-PTMs and their consequences on STAT1-dependent transcriptional program induction and antiviral immune response.

The amino acid taurine is essential for the function of skeletal muscle and administration is proposed as a treatment for Duchenne Muscular Dystrophy (DMD). Taurine homeostasis is dependent on multiple processes including absorption of taurine from food, endogenous synthesis from cysteine and reabsorption in the kidney. This study investigates the cause of reported taurine deficiency in the dystrophic mdx mouse model of DMD. Levels of metabolites (taurine, cysteine, cysteine sulfinate and hypotaurine) and proteins (taurine transporter [TauT], cysteine deoxygenase and cysteine sulfinate dehydrogenase) were quantified in juvenile control C57 and dystrophic mdx mice aged 18 days, 4 and 6 weeks. In C57 mice, taurine content was much higher in both liver and plasma at 18 days, and both cysteine and cysteine deoxygenase were increased. As taurine levels decreased in maturing C57 mice, there was increased transport (reabsorption) of taurine in the kidney and muscle. In mdx mice, taurine and cysteine levels were much lower in liver and plasma at 18 days, and in muscle cysteine was low at 18 days, whereas taurine was lower at 4: these changes were associated with perturbations in taurine transport in liver, kidney and muscle and altered metabolism in liver and kidney. These data suggest that the maintenance of adequate body taurine relies on sufficient dietary intake of taurine and cysteine availability and metabolism, as well as retention of taurine by the kidney. This research indicates dystrophin deficiency not only perturbs taurine metabolism in the muscle but also affects taurine metabolism in the liver and kidney, and supports targeting cysteine and taurine deficiency as a potential therapy for DMD.