The scent of senescence: sexual signalling and female preference in house mice.

Sexual signals are expected to be costly to produce and maintain, thus ensuring that only males in good condition can sustain their expression at high levels. When males reach senescence they lose physiological function and condition, which could constrain their ability to invest in costly sexual signals, decreasing their attractiveness to mates. Furthermore, females may have evolved mating preferences that cause avoidance of senesced males to enhance fertilization success and viability of offspring. Among mammals, the size of antlers and other weapons can decrease with senescence, but changes in olfactory sexual signals have been largely unexplored. We examined changes in olfactory signals with senescence in house mice (Mus musculus domesticus), where males excrete volatile and involatile molecules in scent marks that elicit behavioural and priming responses in females. Compared to middle-aged males, the urine of senesced males contained a lower concentration of involatile signalling proteins (major urinary proteins or MUPs), and associated volatiles that bind to these proteins. The reduced intensity of male scent will affect the longevity of scent signals deposited in the environment and, accordingly, females were less attracted to urine from senesced males deposited 12 h previously. Females also discriminated against senesced males encountered behind a mesh barrier. These results reveal that investment in olfactory signalling is reduced during senescence and suggest that senesced males and their scent may be less attractive to females.

Teladorsagia circumcincta: activation-associated secreted proteins in excretory/secretory products of fourth stage larvae are targets of early IgA responses in infected sheep.

A detailed proteomic analysis of excreted/secretory (ES) proteins derived from fourth stage larvae (L4) of Teladorsagia circumcincta identified a number of components, including N-type and C-type single domain activation-associated secreted proteins (ASPs). Immunoblotting of L4 ES extracts with abomasal mucus derived from infected, immune sheep demonstrated the immunogenicity of some of these components, including an N-type single-domain ASP, designated Tci-ASP-1. The full-length cDNA encoding this protein was isolated and sequenced. Homology searches using the inferred amino acid sequence of Tci-ASP-1 showed that it had highest identity (75% over 231 residues) to, a N-type, single-domain ASP from Ostertagia ostertagi. Phylogenetic analysis confirmed the relationship of Tci-ASP-1 with other N-type ASPs. Reverse-transcriptase (RT)-PCR experiments demonstrated the presence of transcript encoding Tci-ASP-1 in L4 and adult stage T. circumcincta but not in pre-parasitic stages such as eggs and third stage larvae. A recombinant version of Tci-ASP-1 was expressed in Escherichia coli and the purified protein was reactive with IgA present in abomasal mucus derived from immune sheep.

A proteome-integrated, carbon source dependent genetic regulatory network in Saccharomyces cerevisiae.

Integrated regulatory networks can be powerful tools to examine and test properties of cellular systems, such as modelling environmental effects on the molecular bioeconomy, where protein levels are altered in response to changes in growth conditions. Although extensive regulatory pathways and protein interaction data sets exist which represent such networks, few have formally considered quantitative proteomics data to validate and extend them. We generate and consider such data here using a label-free proteomics strategy to quantify alterations in protein abundance for S. cerevisiae when grown on minimal media using glucose, galactose, maltose and trehalose as sole carbon sources. Using a high quality-controlled subset of proteins observed to be differentially abundant, we constructed a proteome-informed network, comprising 1850 transcription factor interactions and 37 chaperone interactions, which defines the major changes in the cellular proteome when growing under different carbon sources. Analysis of the differentially abundant proteins involved in the regulatory network pointed to their significant roles in specific metabolic pathways and function, including glucose homeostasis, amino acid biosynthesis, and carbohydrate metabolic process. We noted strong statistical enrichment in the differentially abundant proteome of targets of known transcription factors associated with stress responses and altered carbon metabolism. This shows how such integrated analysis can lend further experimental support to annotated regulatory interactions, since the proteomic changes capture both magnitude and direction of gene expression change at the level of the affected proteins. Overall this study highlights the power of quantitative proteomics to help define regulatory systems pertinent to environmental conditions.

Assessing the validity of EQ-5D-5L in people with head & neck cancer: Does a generic quality of life measure perform as well as a disease-specific measure in a patient population?

BACKGROUND: Head and neck cancer (HNC) is an important cause of morbidity and mortality globally. Radical treatment methods may result in facial disfigurement and/or functional difficulties with subsequent adverse impacts on health-related quality of life (HRQoL). Guidelines suggest that HRQoL should be measured repeatedly throughout treatment to enable refined treatment protocols and tailored follow-up support but questionnaires are often long and burdensome. We compared condition-specific and generic metrics to assess HRQoL for people with this condition. METHODS: We used data from the prospective Head and Neck 5000 clinical cohort study - 5511 participants with a new diagnosis of HNC between 2011 and 2014. HRQoL data were collected at baseline from 2065 people who completed both the condition-specific EORTC-QLQ-C30 and the shorter, generic EQ-5D-5L questionnaires. RESULTS: There was strong evidence of association between comparable scales on each questionnaire at baseline: higher levels of functioning and lower levels of reported symptoms assessed with EQ-5D-5L were associated with lower EORTC-QLQ-C30 symptom scores. A moderate relationship (0.61) was found between overall QoL in the EQ-5D-5L index and self-perceived health (EQ VAS). CONCLUSIONS: HRQoL data collected from the generic EQ-5D-5L and cancer-specific EORTC-QLQ-C30 questionnaires are comparable at baseline for people diagnosed with HNC. This would allow a reduced burden of data collection but the EQ-5D-5L may not be sensitive to some condition-specific symptoms. Clinicians and researchers must clarify their aims and outcomes of interest before choosing their HRQoL measures. Further work is required to examine the ability to detect change in these measures over time.

Deficiency of a kidney metalloproteinase activity in inbred mouse strains.

Kidneys from BALB/c mice contain a potent metalloendoproteinase, termed meprin, that is active against large proteins as well as small peptides. The enzyme is present in mouse strains C57BR/cdJ, C57BL/6J, BALB/cJ, A/J, DBA/IJ, CD/l, Swiss, and ICR. Three related inbred strains, CBA/J, CBA/CaJ, and C3H/He, are markedly deficient in this enzymatic activity. This is the first report of a heritable deficiency of an intracellular proteinase in mammalian tissues. Meprin deficiency appears to have arisen as an early event in the development of the C stock. Furthermore, meprin is present in the progeny of a cross between a meprin-sufficient female (C57BL/6) and a meprin-deficient male (C3H/HeN), an indication that the trait for the deficiency is recessive.

Cold-induced expression of delta 9-desaturase in carp by transcriptional and posttranslational mechanisms.

Poikilothermic animals respond to chronic cold by increasing phosphoglyceride unsaturation to restore the fluidity of cold-rigidified membranes. Despite the importance of this compensatory response, the enzymes involved have not been clearly identified, and the mechanisms that control their activity are unknown. In carp liver, cold induces an 8- to 10-fold increase in specific activity of the microsomal stearoyl coenzyme A desaturase. Cold-induced up-regulation of gene transcription resulted in a 10-fold increase in desaturase transcript amounts after 48 to 60 hours. However, this increase was preceded by the activation of latent desaturase, probably by a posttranslational mechanism. These two mechanisms may act sequentially to match desaturase expression to the demands imposed by a progressive decrease in temperature.

Proteomic analysis of excretory/secretory products released by Teladorsagia circumcincta larvae early post-infection.

Teladorsagia circumcincta is an important parasitic nematode of domestic small ruminants. Drug resistance in this species is common so alternative methods of control are required. As animals develop immunity to T. circumcincta, vaccination is a valid option. Little is known about the antigens that play a role in stimulating immunity at this host/parasite interface. As responses generated between 1 and 5 dpi are known to affect development of these nematodes in their gastric niche, we focused on proteins released during the early stages of infection. To identify molecules potentially involved in immunity, we undertook a proteomics analysis of proteins released from larvae harvested at 1-, 3- and 5-days post-infection (dpi). This analysis produced peptide sequence data that was used to search information available in T. circumcincta expressed sequence tag (EST) databases and enabled identification of a number of excretory/secretory (ES) proteins. Immunoblots were performed to assess the relative molecular weight of ES antigens that were targets of local IgA responses in mucus from sheep rendered immune to infection. ELISA was performed to assess antigen-specific mucus IgA levels in individual sheep. These experiments provided preliminary evidence that the proteins identified in the larval secretome were subject to these antibody responses.

Local recurrence after abdomino-perineal resection.

OBJECTIVE: Local recurrence of rectal cancer is a major cause of morbidity and mortality following curative resection. The published rates vary after abdomino-perineal resection (APR) from 5% to 47%. The aim of this study was to evaluate local recurrence following curative APR for low rectal cancer in our unit. METHOD: The medical notes of patients treated between 1st January 1996 and 31st December 2000 were retrieved. Local recurrence was defined as the presence of tumour within the pelvis confirmed by clinical findings, pathological specimen or radiological reports. A curative resection was defined as excision of tumour in the absence of macroscopic metastatic disease and whose resection margins were greater than 1 mm circumferentially and 10 mm distally. Outcomes and survival were compared using Fisher's exact test and Kaplan-Meier method. RESULTS: Two hundred consecutive cases with a diagnosis of rectal cancer were identified of which 139 underwent a curative resection (69.5%). Of these 40 patients (28%) underwent APR with curative intent. Two patients (5%) developed local recurrence at 18 and 24 months respectively. The overall local recurrence rate for all curative rectal cancer surgery, in the same period was 2.6%. Eleven patients have died in the follow-up period of which nine were cancer-related deaths. CONCLUSION: The local recurrence rates achieved with APR were not significantly different from those achieved with restorative operations. Tumours at the ano-rectal junction should not be dissected off the pelvic floor, but radically excised en bloc with the surrounding levator ani, as a cylinder, as originally described by Miles.

Pharmacological and nutritional treatment for McArdle disease (Glycogen Storage Disease type V).

BACKGROUND: McArdle disease (Glycogen Storage Disease type V) is caused by the absence of the glycolytic enzyme, muscle phosphorylase. People present with exercise-induced pain, cramps, fatigue, and myoglobinuria, which can result in acute renal failure if it is severe. OBJECTIVES: To systematically review the evidence from randomised controlled trials of pharmacological or nutritional treatments in improving exercise performance and quality of life in McArdle disease. SEARCH STRATEGY: We updated the review by searching the Cochrane Neuromuscular Disease Group Trials Register (November 2007), MEDLINE (January 1966 to November 2007) and EMBASE (January 1980 to November 2007) using the search terms 'McArdle disease' and its synonym 'Glycogen Storage Disease type V'. SELECTION CRITERIA: We included randomised controlled trials (including crossover studies) and quasi-randomised trials. Open trials and individual patient studies with no participant or observer blinding were included in the discussion. Types of interventions included any pharmacological agent or micronutrient or macronutrient supplementation. Primary outcome measures included any objective assessment of exercise endurance (for example aerobic capacity (VO(2)) max, walking speed, muscle force or power and improvement in fatiguability). Secondary outcome measures included metabolic changes (such as reduced plasma creatine kinase activity and a reduction in the frequency of myoglobinuria), subjective measures (including quality of life scores and indices of disability) and serious adverse events. DATA COLLECTION AND ANALYSIS: Three review authors checked the titles and abstracts identified by the search and reviewed the manuscripts. Two review authors (RQ and RB) independently assessed methodological quality of the full text of potentially relevant studies and extracted data onto a specially designed form. MAIN RESULTS: We reviewed 24 studies. Twelve trials fulfilled the criteria for inclusion, with two being first identified in this update. The 12 excluded trials are included in the discussion. The largest treatment trial included 19 cases. The other trials included fewer than 12 cases. As there were only single trials for a given intervention we were unable to undertake a meta-analysis. AUTHORS' CONCLUSIONS: There is no evidence of significant benefit from any specific nutritional or pharmacological treatment in McArdle disease. In one small trial low dose creatine produced slight benefit but high dose creatine caused myalgia. Ingestion of oral sucrose immediately before exercise reduced perceived ratings of exertion and heart rate and improved exercise tolerance. This treatment will not influence sustained or unexpected exercise and may cause significant weight gain. A carbohydrate rich diet did benefit patients. Because of the rarity of McArdle disease, there is a need to develop international multicentre collaboration and standardised assessment protocols for future treatment trials.

Avian proteomics: advances, challenges and new technologies.

Proteomics is defined as an analysis of the full complement of proteins of a cell or tissue under given conditions. Avian proteomics, or more specifically chicken proteomics, has focussed on the study of individual tissues and organs of interest to specific researchers. Researchers have looked at skeletal muscle and growth, and embryonic development and have performed initial studies in avian disease. Traditional proteomics involves identifying and cataloguing proteins in a cell and identifying relative changes in populations between two or more states, be that physiological or disease-induced states. Recent advances in proteomic technologies have included absolute quantification, proteome simplification and the ability to determine the turnover of individual proteins in a global context. This review discusses the current developments in this relatively new field, new technologies and how they may be applied to biological questions, and the challenges faced by researchers in this ever-expanding and exciting field.

Pharmacological and nutritional treatment trials in McArdle disease.

A systematic review of evidence for randomised controlled trials using pharmacologic and nutritional therapies in McArdle disease was undertaken. Primary outcome measures included any objective assessment of exercise endurance. Secondary outcome measures included changes in metabolic parameters, subjective measures such as quality of life scores and adverse outcomes. Ten randomised controlled trials were identified. Two trials low dose creatine (60 mg/kg/day) and oral sucrose 75 g prior to exercise demonstrated a positive effect.

Elastase levels and activity are increased in dystrophic muscle and impair myoblast cell survival, proliferation and differentiation.

In Duchenne muscular dystrophy, progressive loss of muscle tissue is accompanied by fibrosis, chronic inflammation and reduced muscle regenerative capacity. Although much is known about the development of fibrosis and chronic inflammation in muscular dystrophy, less is known about how they are mechanistically linked to loss of muscle regenerative capacity. We have developed a proteomics method to discover dystrophy-associated changes in the muscle progenitor cell niche, which identified serine proteases, and especially neutrophil elastase, as candidates. We show that elastase activity is increased in dystrophic (mdx(4cv)) muscle and impairs myoblast survival in culture. While the effect of elastase on C2C12 cell survival correlates with the kinetics of elastase-mediated degradation of the substrate to which the cells adhere, the effect of elastase on satellite cell-derived primary myoblast growth and differentiation is substrate-independent and even more dramatic than the effect on C2C12 cells, suggesting a detrimental role for elastase on myogenesis in vivo. Additionally, elastase impairs differentiation of both primary and C2C12 myoblasts into myotubes. Our findings evidence the importance of neutrophil-mediated inflammation in muscular dystrophy and indicate elastase-mediated regulation of myoblast behaviour as a potential mechanism underlying loss of regenerative capacity in dystrophic muscle.

Chymotryptic activation of glutamate dehydrogenase.

Treatment of bovine liver glutamate dehydrogenase (L-glutamate:NAD(P)+ oxidoreductase (deaminating), EC 1.4.1.3) with chymotrypsin generates a proteolytic derivative that is activated 3-4-fold over the native enzyme. Stable preparations of activated enzyme show altered kinetic parameters (5-fold increase in Km for glutamate, 3-fold increase in Vmax) and altered response to allosteric modulation by GTP and ADP. The proteolysed enzyme was less responsive to GTP and was no longer activated by ADP, although ADP binding sites remained intact on the enzyme. The effect of ADP upon substrate inhibition was altered and negative homotropic interactions in coenzyme binding were abolished.

Immunological characterisation of different meprin species in mice.

Meprin-a is a metalloendopeptidase present at high levels in the kidney brush border of some inbred mouse strains. Meprin-b is a latent metallo-endopeptidase, activated by trypsin-mediated proteolysis in vitro, that is present at similar activities (after activation) in all mouse strains. Meprin (a mixture of a and b forms) was purified from a high-meprin Mep-1a/a animal, and Lys-C peptides of this preparation were sequenced. The sequence data were used to direct the synthesis of peptides that were conjugated to albumin and used as immunogens. One of these antisera was specific to meprin-b and thus provided a specific tool to monitor expression of this form of meprin in different mouse strains.

McArdle's disease: a rare frameshift mutation in exon 1 of the muscle glycogen phosphorylase gene.

We have previously discovered a common nonsense mutation in exon 1 of the myophosphosphorylase gene in patients with McArdle's disease, but this failed to explain all cases. We now report a second mutation (G-->TT) in one patient, also in exon 1. This mutation causes a shift in the reading frame which results in the replacement of Val15 by Phe. A further 10 amino acids of mis-sense protein are synthesised before a stop codon is reached.

The turnover of skeletal muscle glycogen phosphorylase studied using the cofactor, pyridoxal phosphate, as a specific label.

The turnover of glycogen phosphorylase has been measured using the cofactor, pyridoxal phosphate, as a label specific for this enzyme in skeletal muscle. Radiolabelled pyridoxine administered in vivo is incorporated into a protein-bound fraction in skeletal muscle, shown by several criteria to be equivalent to glycogen phosphorylase. This pool of radiolabel disappears slowly with a half-life of 11.9 days, taken to be a good estimate of the intracellular half-life of the enzyme. The use of the cofactor in this fashion minimises overestimation of half-life that results from reincorporation of the label. Further, premature dissociation of the cofactor from native enzyme, which would lead to underestimation of half-life, is unlikely. At the level of sensitivity given by this method there was little evidence for the appearance of pyridoxal phosphate-labelled degradation intermediates of the enzyme.

The effect of analogues of chymostatin on lysosomal and non-lysosomal components of protein degradation in isolated hepatocytes.

Of the proteinase inhibitors derived from Streptomyces spp., chymostatin is the most effective inhibitor of non-lysosomal proteolysis. As part of a systematic study of the structural features of the chymostatin molecule that are responsible for this inhibitory activity, a series of fifteen di- and tripeptide analogues of chymostatin were tested for their ability to suppress protein degradation in isolated primary hepatocytes. Protein degradation was assessed in two ways: by the release of radiolabel from proteins prelabelled in vivo (to which both lysosomal and non-lysosomal processes contribute) and by the rate of inactivation of tyrosine aminotransferase, a process that is exclusively non-lysosomal. All inhibitors were relatively non-toxic and did not affect the intracellular ATP levels, although some suppression of gluconeogenesis was observed in the presence of leupeptin, chymostatin or the analogues. Tripeptide phenylalanine aldehydes or semicarbazones were at least as effective as chymostatin in reducing protein degradation, whereas peptide alcohols were relatively ineffective. Replacement of the basic capreomycidine moiety in chymostatin with an arginine residue improved the inhibitory activity but equally, substitution of the arginine residue with an uncharged norleucine residue was without significant effect. The structural features that are optimal for inhibition of chymotrypsin or other serine proteinases (previously defined) are not as critical for inhibition of protein degradation in vivo.

Proteolytic activity in mouse urine: relationship to the kidney metallo-endopeptidase, meprin.

Meprin, a brush border kidney metallo-endopeptidase is present as the major endopeptidase in mouse urine. The enzyme is freely soluble and can be detected enzymically or immunologically. Mice can be partitioned into two phenotypes that differ by 10-20-fold in the amount of meprin in kidney membranes; this phenotypic variation is reflected in urinary activities. We propose a role for meprin in the degradation of other urinary proteins.

Molecular heterogeneity in McArdle's disease.

Biopsies were taken from a group of eleven patients with McArdle's disease, a congenital deficiency in muscle glycogen phosphorylase. The biopsies were screened by Western and Northern blotting for phosphorylase protein, phosphorylase-bound pyridoxal-5'-phosphate (the cofactor of the enzyme) and for phosphorylase mRNA. Of the eleven patients, three expressed phosphorylase mRNA at near normal levels and at the expected size. One of these patients also expressed low levels of phosphorylase protein that correlated with a small amount of measurable phosphorylase activity. These data support the contention of molecular heterogeneity in the presentation of this phenotype.

The greater susceptibility of North Ronaldsay sheep compared with Cambridge sheep to copper-induced oxidative stress, mitochondrial damage and hepatic stellate cell activation.

Sheep of the semi-feral North Ronaldsay (copper-sensitive) and domesticated Cambridge (copper-tolerant) breeds were compared in respect of pathological changes and protein expression in the liver as a result of excessive dietary copper. Acute mitochondrial damage and hepatic stellate cell (HSC) activation with collagen synthesis occurred in response to moderate copper overload in North Ronaldsay but not in Cambridge sheep. Mitochondrial degradative changes occurred either as ballooning degeneration and rupture with subsequent autophagic degradation or as mitochondrial matrical condensation (pyknosis). In North Ronaldsay sheep prolonged exposure to copper produced mitochondrial hyperplasia and hypertrophy, and nuclear damage with necrosis. Cytosolic isocitrate dehydrogenase (IDH), an enzyme responsive to oxidative stress, was induced in the liver of Cambridge sheep receiving a Cu-supplemented diet but was undetectable in the non-supplemented control sheep. Conversely, IDH was detected at similar levels in both control and copper-supplemented North Ronaldsay sheep, indicating a lower threshold response, and an enhanced susceptibility, to oxidative stress. "Upregulation" of mitochondrial thioredoxin-dependent peroxidase reductase (antioxidant protein-1) in the hepatic cytosol of the North Ronaldsay (but not Cambridge) sheep affirmed the increased susceptibility of the mitochondria to Cu-induced oxidative stress in this breed. Likewise the upregulation of cathepsin-D indicated increased lysosomal activity and HSC activation. The findings may be relevant to copper toxicosis in human infants.