Non-alcoholic fatty liver disease—A pilot study investigating early inflammatory and fibrotic biomarkers of NAFLD with alcoholic liver disease

Introduction: Non-alcoholic fatty liver disease (NAFLD) is a condition where excess fat accumulates in the liver (hepatic steatosis) and there is no history of alcohol abuse or other secondary causes of chronic liver disease. NAFLD is a very common disorder, occurring in 25% of the global population. NAFLD is now the most common chronic liver disorder in Western countries. Liver biopsy is the gold standard for NAFLD diagnosis and staging; however, this is invasive, costly and not without risk. Biomarkers that could diagnose and stage disease would reduce the need for biopsy and allow stratification of patients at risk of progression to non-alcoholic steatohepatitis (NASH).Methods: One hundred and thirty-five patients were involved in the study [N = 135: n = 34 controls; n = 26 simple steatosis; n = 61 NAFLD/NASH, and n = 14 alcoholic liver disease (ALD)]. Clinically diagnosed (ICD-10) patient serum samples were obtained from Discovery Life Sciences (US) along with clinical history. Samples were run in duplicate using high-sensitivity cytokine array I, immunoassays and ELISAs. In total, n = 20 individual biomarkers were investigated in this pilot study.Results: Thirteen/20 (65%) biomarkers were identified as significantly different between groups; IFNγ, EGF, IL-1β, IL-6, IL-8, IL-10, TNFα, FABP-1, PIIINP, ST2/IL-33R, albumin, AST and ALT. Five/20 (25%) biomarker candidates were identified for further investigation; namely, three biomarkers of inflammation, IL-6, IL-8, and TNFα, and two biomarkers of fibrosis, PIIINP and ST2/IL-33R.Discussion: Single biomarkers are unlikely to be diagnostic or predictive at staging NAFLD due to the complex heterogeneity of the disease. However, biomarker combinations may help stratify risk and stage disease where patients are averse to biopsy. Further studies comparing the 5 biomarkers identified in this study with current diagnostic tests and fibrotic deposition in liver tissue are warranted

Analysis of reactive aldehydes in urine and plasma of type-2 diabetes mellitus patients through liquid chromatography-mass spectrometry: Reactive aldehydes as potential markers of diabetic nephropathy

IntroductionDiabetes is a major public health issue that is approaching epidemic proportions globally. Diabetes mortality is increasing in all ethnic groups, irrespective of socio-economic class. Obesity is often seen as the main contributor to an increasing prevalence of diabetes. Oxidative stress has been shown to trigger obesity by stimulating the deposition of white adipose tissue. In this study, we measured reactive aldehydes by liquid chromatography-mass spectrometry (LC-MS), in the urine and plasma of type-2 diabetic mellitus (T2DM) patients, as potential surrogates of oxidative stress. Our hypothesis was that reactive aldehydes play a significant role in the pathophysiology of diabetes, and these reactive species, may present potential drug targets for patient treatment.Materials and methodsStudy participants [N = 86; control n = 26; T2DM n = 32, and diabetic nephropathy (DN) n = 28] were recruited between 2019 and 2020. Urine and blood samples were collected from all participants, including a detailed clinical history, to include patient behaviours, medications, and co-morbidities. Reactive aldehyde concentrations in urine and plasma were measured using pre-column derivatisation and LC-MS, for control, T2DM and DN patients.ResultsReactive aldehydes were measured in the urine and plasma of control subjects and patients with T2DM and DN. In all cases, the reactive aldehydes under investigation; 4-HNE, 4-ONE, 4-HHE, pentanal, methylglyoxal, and glyoxal, were significantly elevated in the urine and serum of the patients with T2DM and DN, compared to controls (p < 0.001) (Kruskal–Wallis). Urine and serum reactive aldehydes were significantly correlated (≥0.7) (p < 0.001) (Spearman rho). The concentrations of the reactive aldehydes were significantly higher in plasma samples, when compared to urine, suggesting that plasma is the optimal matrix for screening T2DM and DN patients for oxidative stress.ConclusionReactive aldehydes are elevated in the urine and plasma of T2DM and DN patients. Reactive aldehydes have been implicated in the pathobiology of T2DM. Therefore, if reactive aldehydes are surrogates of oxidative stress, these reactive aldehyde species could be therapeutic targets for potential drug development

A bioluminescent microbial biosensor for in vitro pretreatment assessment of cytarabine efficacy in leukemia

BACKGROUND: The nucleoside analog cytarabine (Ara-C [cytosine arabinoside]) is the key agent for treating acute myeloid leukemia (AML); however, up to 30% of patients fail to respond to treatment. Screening of patient blood samples to determine drug response before commencement of treatment is needed. This project aimed to construct and evaluate a self-bioluminescent reporter strain of Escherichia coli for use as an Ara-C biosensor and to design an in vitro assay to predict Ara-C response in clinical samples. METHODS: Weused transposition mutagenesis to create a cytidine deaminase (cdd)-deficient mutant of E. coli MG1655 that responded to Ara-C. The strain was transformed with the luxCDABE operon and used as a whole-cell biosensor for development an 8-h assay to determine Ara-C uptake and phosphorylation by leukemic cells. RESULTS: Intracellular concentrations of 0.025 μmol/L phosphorylated Ara-C were detected by significantly increased light output (P < 0.05) from the bacterial biosensor. Results using AML cell lines with known response to Ara-C showed close correlation between the 8-h assay and a 3-day cytotoxicity test for Ara-C cell killing. In retrospective tests with 24 clinical samples of bone marrow or peripheral blood, the biosensor-based assay predicted leukemic cell response to Ara-C within 8 h. CONCLUSIONS: The biosensor-based assay may offer a predictor for evaluating the sensitivity of leukemic cells to Ara-C before patients undergo chemotherapy and allow customized treatment of drug-sensitive patients with reduced Ara-C dose levels. The 8-h assay monitors intracellular Ara-CTP (cytosine arabinoside triphosphate) levels and, if fully validated, may be suitable for use in clinical settings. © 2010 American Association for Clinical Chemistry

Protein disulfide-isomerase interacts with a substrate protein at all stages along its folding pathway

In contrast to molecular chaperones that couple protein folding to ATP hydrolysis, protein disulfide-isomerase (PDI) catalyzes protein folding coupled to formation of disulfide bonds (oxidative folding). However, we do not know how PDI distinguishes folded, partly-folded and unfolded protein substrates. As a model intermediate in an oxidative folding pathway, we prepared a two-disulfide mutant of basic pancreatic trypsin inhibitor (BPTI) and showed by NMR that it is partly-folded and highly dynamic. NMR studies show that it binds to PDI at the same site that binds peptide ligands, with rapid binding and dissociation kinetics; surface plasmon resonance shows its interaction with PDI has a Kd of ca. 10−5 M. For comparison, we characterized the interactions of PDI with native BPTI and fully-unfolded BPTI. Interestingly, PDI does bind native BPTI, but binding is quantitatively weaker than with partly-folded and unfolded BPTI. Hence PDI recognizes and binds substrates via permanently or transiently unfolded regions. This is the first study of PDI's interaction with a partly-folded protein, and the first to analyze this folding catalyst's changing interactions with substrates along an oxidative folding pathway. We have identified key features that make PDI an effective catalyst of oxidative protein folding – differential affinity, rapid ligand exchange and conformational flexibility

Symptom-based stratification of patients with primary Sjögren's syndrome: multi-dimensional characterisation of international observational cohorts and reanalyses of randomised clinical trials

Background Heterogeneity is a major obstacle to developing effective treatments for patients with primary Sjögren's syndrome. We aimed to develop a robust method for stratification, exploiting heterogeneity in patient-reported symptoms, and to relate these differences to pathobiology and therapeutic response. Methods We did hierarchical cluster analysis using five common symptoms associated with primary Sjögren's syndrome (pain, fatigue, dryness, anxiety, and depression), followed by multinomial logistic regression to identify subgroups in the UK Primary Sjögren's Syndrome Registry (UKPSSR). We assessed clinical and biological differences between these subgroups, including transcriptional differences in peripheral blood. Patients from two independent validation cohorts in Norway and France were used to confirm patient stratification. Data from two phase 3 clinical trials were similarly stratified to assess the differences between subgroups in treatment response to hydroxychloroquine and rituximab. Findings In the UKPSSR cohort (n=608), we identified four subgroups: Low symptom burden (LSB), high symptom burden (HSB), dryness dominant with fatigue (DDF), and pain dominant with fatigue (PDF). Significant differences in peripheral blood lymphocyte counts, anti-SSA and anti-SSB antibody positivity, as well as serum IgG, κ-free light chain, β2-microglobulin, and CXCL13 concentrations were observed between these subgroups, along with differentially expressed transcriptomic modules in peripheral blood. Similar findings were observed in the independent validation cohorts (n=396). Reanalysis of trial data stratifying patients into these subgroups suggested a treatment effect with hydroxychloroquine in the HSB subgroup and with rituximab in the DDF subgroup compared with placebo. Interpretation Stratification on the basis of patient-reported symptoms of patients with primary Sjögren's syndrome revealed distinct pathobiological endotypes with distinct responses to immunomodulatory treatments. Our data have important implications for clinical management, trial design, and therapeutic development. Similar stratification approaches might be useful for patients with other chronic immune-mediated diseases. Funding UK Medical Research Council, British Sjogren's Syndrome Association, French Ministry of Health, Arthritis Research UK, Foundation for Research in Rheumatology

Musiikkikoulutuksen opiskelijoiden näkemyksiä pääaineen pedagogiikan opinnoista

Kehittämishankkeeni aiheen valinta liittyy opintosuunnitelmien katsaukseen ja uudistukseen. Musiikkikoulutus ammattikorkeakouluissa elää vaikeita aikoja - musiikikoulutusten lopettamisen uhka ja aloituspaikkojen leikkaukset. On noussut erittäin tärkeäksi kysymys: vastaako musiikkikoulutus työelämän tarpeisiin? Vastaakseen tähän kysymykseen on kaavailtu opintosuunnitelmien kriittistä tarkastusta. Musiikinopettajan tulisi olla luova muusikko ja monipuolinen taitelija, tiedostava pedagogi ja innovatiivinen työelämäntaitaja. Näiden kompetenssien vahvistamiseksi opetuksessa tarvitaan opintosuunnitelmien uudistusta, jossa pyritään kehittämään sellaista ammattipedagogiikan opintokokonaisuutta, joka olisi käytännönläheinen, monipuolinen, luovutta ja opettajuuden muotoutumista ja kehittämistä edistävä ja tukeva. Tässä kehittämishankkeessa pyrin selvittämään, mitä vahvuuksia ja puutteita on nykyisessä musiikkiopiskelijoiden pääaineen pedagogiikan ja opetusharjoittelun opintojaksossa. Yksi kehittämishankkeeni tavoitteista oli tutustua opiskelijoiden odotuksiin ja käsityksiin opetusharjoittelusta. Kyselyn toteutin eri pääaineiden opiskelijoiden (laulu, piano, viulu, sello, pasuuna, klarinetti) sähköpostitse. Kehittämishankkeen toteuttamisen prosessissa yritin pohtia, mitkä muutokset kyseisessä opintojaksossa voisivat olla hyödyllisiä opiskelijoille ja miten voisi konkreettisesti sisältää niitä opetussuunnitelmaan

Solution structure of Oxidised ERp18

Primary Citation: Rowe, M.L.; Ruddock, L.W.; Kelly, G.; Schmidt, J.M.; Williamson, R.A.; Howard, M.J. "Solution structure and dynamics of ERp18, a small endoplasmic reticulum resident oxidoreductase." Journal: (2009) Biochemistry 48: 4596-4606. PubMed: 19361226. DOI: 10.1021/bi9003342. Molecular Description: Classification: Oxidoreductase, Structure Weight: 17801.10 Da, Molecule: Thioredoxin domain-containing protein 12, Polymer: 1, Type: polypeptide(L), Length: 157, Chains: A, EC#: 1.8.4.2, Fragment: UNP residues 24-172. Source: Scientific Name: Homo sapiens, Common Name: Human, Expression System: Escherichia coli

Kent Academic Repository Full text document (pdf) Versions of research Citation for published version Link to record in KAR Mapping of the ligand-binding site on the b ′ domain of human PDI: interaction with peptide ligands and the x-linker region

PDI (protein disulfide-isomerase) catalyses the formation of native disulfide bonds of secretory proteins in the endoplasmic reticulum. PDI consists of four thioredoxin-like domains, of which two contain redox-active catalytic sites (a and a ′ ), and two do not (b and b ′ ). The b ′ domain is primarily responsible for substrate binding, although the nature and specificity of the substrate-binding site is still poorly understood. In the present study, we show that the b ′ domain of human PDI is in conformational exchange, but that its structure is stabilized by the addition of peptide ligands or by binding the x-linker region. The location of the ligand-binding site in b ′ was mapped by NMR chemical shift perturbation and found to consist primarily of residues from the core β-sheet and α-helices 1 and 3. This site is where the x-linker region binds in the X-ray structure of b ′ x and we show that peptide ligands can compete with x binding at this site. The finding that x binds in the principal ligand-binding site of b ′ further supports the hypothesis that x functions to gate access to this site and so modulates PDI activity

Solution structure and dynamics of ERp18, a small endoplasmic reticulum resident oxidoreductase

Here we report the solution structure of oxidized ERp18 as determined using NMR spectroscopy. ERp18 is the smallest member of the protein disulfide isomerase (PDI) family of proteins to contain a Cys-Xxx-Xxx-Cys active site motif. It is an 18 kDa endoplasmic reticulum resident protein with unknown function although sequence similarity to individual domains of the thiol-disulfide oxidoreductase PDI suggests ERp18 may have a similar structure and function. Like the catalytic domains of PDI, ERp18 adopts a thioredoxin fold with a thioredoxin-like active site located at the N-terminus of a long kinked helix that spans the length of the protein. Comparison of backbone chemical shifts for oxidized and reduced ERp18 shows the majority of residues possess the same backbone conformation in both states, with differences limited to the active site and regions in close proximity. S(2) order parameters from NMR backbone dynamics were found to be 0.81 for oxidized and 0.91 for reduced ERp18, and these observations, in combination with amide hydrogen exchange rates, imply a more rigid and compact backbone for the reduced structure. These observations support a putative role for ERp18 within the cell as an oxidase, introducing disulfide bonds to substrate proteins, providing structural confirmation of ERp18's role as a thiol-disulfide oxidoreductase