MANF regulates neuronal survival and UPR through its ER-located receptor IRE1α

Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an endoplasmic reticulum (ER)-located protein with cytoprotective effects in neurons and pancreatic β cells in vitro and in models of neurodegeneration and diabetes in vivo. However, the exact mode of MANF action has remained elusive. Here, we show that MANF directly interacts with the ER transmembrane unfolded protein response (UPR) sensor IRE1α, and we identify the binding interface between MANF and IRE1α. The expression of wild-type MANF, but not its IRE1α binding-deficient mutant, attenuates UPR signaling by decreasing IRE1α oligomerization; phosphorylation; splicing of Xbp1, Atf6, and Txnip levels; and protecting neurons from ER stress-induced death. MANF-IRE1α interaction and not MANF-BiP interaction is crucial for MANF pro-survival activity in neurons in vitro and is required to protect dopamine neurons in an animal model of Parkinson's disease. Our data show IRE1α as an intracellular receptor for MANF and regulator of neuronal survival.

Effect of Salinity on Leaf Functional Traits and Chloroplast Lipids Composition in Two C3 and C4 Chenopodiaceae Halophytes

Salt stress is one of the most common abiotic kinds of stress. Understanding the key mechanisms of salt tolerance in plants involves the study of halophytes. The effect of salinity was studied in two halophytic annuals of Chenopodiaceae Salicornia perennans Willd. and Climacoptera crassa (Bied.) Botsch. These species are plants with C₃ and C₄-metabolism, respectively. We performed a comprehensive analysis of the photosynthetic apparatus of these halophyte species at different levels of integration. The C₃ species S. perennans showed larger variation in leaf functional traits-both at the level of cell morphology and membrane system (chloroplast envelope and thylakoid). S. perennans also had larger photosynthetic cells, by 10-15 times, and more effective mechanisms of osmoregulation and protecting cells against the toxic effect of Na⁺. Salinity caused changes in photosynthetic tissues of C. crassa such as an increase of the mesophyll cell surface, the expansion of the interface area between mesophyll and bundle sheath cells, and an increase of the volume of the latter. These functional changes compensated for scarce CO₂ supply when salinity increased. Overall, we concluded that these C₃ and C₄ Chenopodiaceae species demonstrated different responses to salinity, both at the cellular and subcellular levels.

Maximum antigen diversification in a lyme bacterial population and evolutionary strategies to overcome pathogen diversity

Natural populations of pathogens and their hosts are engaged in an arms race in which the pathogens diversify to escape host immunity while the hosts evolve novel immunity. This co-evolutionary process poses a fundamental challenge to the development of broadly effective vaccines and diagnostics against a diversifying pathogen. Based on surveys of natural allele frequencies and experimental immunization of mice, we show high antigenic specificities of natural variants of the outer surface protein C (OspC), a dominant antigen of a Lyme Disease-causing bacterium (Borrelia burgdorferi). To overcome the challenge of OspC antigenic diversity to clinical development of preventive measures, we implemented a number of evolution-informed strategies to broaden OspC antigenic reactivity. In particular, the centroid algorithm-a genetic algorithm to generate sequences that minimize amino-acid differences with natural variants-generated synthetic OspC analogs with the greatest promise as diagnostic and vaccine candidates against diverse Lyme pathogen strains co-existing in the Northeast United States. Mechanistically, we propose a model of maximum antigen diversification (MAD) mediated by amino-acid variations distributed across the hypervariable regions on the OspC molecule. Under the MAD hypothesis, evolutionary centroids display broad cross-reactivity by occupying the central void in the antigenic space excavated by diversifying natural variants. In contrast to vaccine designs based on concatenated epitopes, the evolutionary algorithms generate analogs of natural antigens and are automated. The novel centroid algorithm and the evolutionary antigen designs based on consensus and ancestral sequences have broad implications for combating diversifying pathogens driven by pathogen-host co-evolution.

Heat-induced reduction of deoxynivalenol and its modified forms during flaking and cooking of oat

Deoxynivalenol (DON) and its modified forms deoxynivalenol-3-glucoside (DON-3G) and 3-acetyl-deoxynivalenol (3-ADON) are common contaminants in Norwegian oats. In order to provide more information about the fate of these mycotoxins during oat processing, the levels of DON, DON-3G, 3-ADON and the sum of them (total DON) were determined using LC-HRMS/MS at different processing steps. Oat groat was softened by either steaming or conditioning, rolled into flakes of two thicknesses, and subsequently cooked to produce flake porridges. Flour of oat groat (untreated or kilned) was cooked to flour porridges. The flaking process had major effect on the mycotoxin levels in resulting flakes, with significant impact for type of softening regime, but not for flake size. Steam-softening caused the largest reduction of DON, DON-3G and total DON in flakes, retaining 41, 60 and 46%, respectively, compared to oat groat. In contrast, 3-ADON in flakes was most reduced by conditioning, to 29% of the levels in oat groat. Cooking to porridge from flakes did not result in any additional mycotoxin reduction, though significant impact of flake size was shown in the final porridges, with highest reduction of total DON in the porridges originating from steamed thick flakes. Cooking porridge from untreated oat flour gave significant reduction in mycotoxin levels, however not for kilned oat flour which had already undergone reduction during kilning. In conclusion, the study shows that processes involving heat-treatment, i.e. kilning, steaming or cooking, efficiently reduced total DON in oats during flaking and porridge cooking, and reduction is dependent on previous processing steps.

Novel Analogues of the Chikungunya Virus Protease Inhibitor: Molecular Design, Synthesis, and Biological Evaluation

The Chikungunya virus (CHIKV) is an arbovirus belonging to the genus Alphavirus of the Togaviridae family. CHIKV is transmitted by the mosquitoes and causes Chikungunya fever. CHIKV outbreaks have occurred in Africa, Asia, Europe, and the countries of Indian and Pacific Oceans. In 2013, CHIKV cases were registered for the first time in the Americas on the Caribbean islands. There is currently no vaccine to prevent or medicines to treat CHIKV infection. The CHIKV nonstructural protease (nsP2) is a promising potential target for the development of drugs against CHIKV infection because this protein is one of the key components of the viral replication complex and is involved in multiple steps of virus infection. In this work, novel analogues of the potential CHIKV nsP2 protease inhibitor, first reported by Das et al. in 2016, were identified using molecular modeling methods, synthesized, and evaluated in vitro. The optimization of the structure of the inhibitor allowed to increase the antiviral activity of the compound 2-10 times. The possible mechanism of action of the identified potential inhibitors of the CHIKV nsP2 protease was studied in detail using molecular dynamics (MD) simulations. According to the MD results, the most probable mechanism of action is the blocking of conformational changes in the nsP2 protease required for substrate recognition and binding.

Human Cord Blood Derived Unrestricted Somatic Stem Cells Restore Aquaporin Channel Expression, Reduce Inflammation and Inhibit the Development of Hydrocephalus After Experimentally Induced Perinatal Intraventricular Hemorrhage

Intraventricular hemorrhage (IVH) is a severe complication of preterm birth associated with cerebral palsy, intellectual disability, and commonly, accumulation of cerebrospinal fluid (CSF). Histologically, IVH leads to subependymal gliosis, fibrosis, and disruption of the ependymal wall. Importantly, expression of aquaporin channels 1 and 4 (AQP1 and AQP4) regulating respectively, secretion and absorption of cerebrospinal fluids is altered with IVH and are associated with development of post hemorrhagic hydrocephalus. Human cord blood derived unrestricted somatic stem cells (USSCs), which we previously demonstrated to reduce the magnitude of hydrocephalus, as having anti-inflammatory, and beneficial behavioral effects, were injected into the cerebral ventricles of rabbit pups 18 h after glycerol-induced IVH. USSC treated IVH pups showed a reduction in ventricular size when compared to control pups at 7 and 14 days (both, P < 0.05). Histologically, USSC treatment reduced cellular infiltration and ependymal wall disruption. In the region of the choroid plexus, immuno-reactivity for AQP1 and ependymal wall AQP4 expression were suppressed after IVH but were restored following USSC administration. Effects were confirmed by analysis of mRNA from dissected choroid plexus and ependymal tissue. Transforming growth factor beta (TGF-β) isoforms, connective tissue growth factor (CTGF) and matrix metalloprotease-9 (MMP-9) mRNA, as well as protein levels, were significantly increased following IVH and restored towards normal with USSC treatment (P < 0.05). The anti-inflammatory cytokine Interleukin-10 (IL-10) mRNA was reduced in IVH, but significantly recovered after USSC injection (P < 0.05). In conclusion, USSCs exerted anti-inflammatory effects by suppressing both TGF-β specific isoforms, CTGF and MMP-9, recovered IL-10, restored aquaporins expression towards baseline, and reduced hydrocephalus. These results support the possibility of the use of USSCs to reduce IVH consequences in prematurity.

1,3-Thiazolbenzamide Derivatives as Chikungunya Virus nsP2 Protease Inhibitors

Chikungunya fever results from an infection with Chikungunya virus (CHIKV, genus Alphavirus) that is prevalent in tropical regions and is spreading fast to temperate climates with documented outbreaks in Europe and the Americas. Currently, there are no available vaccines or antiviral drugs for prevention or treatment of Chikungunya fever. The nonstructural proteins (nsPs) of CHIKV responsible for virus replication are promising targets for the development of new antivirals. This study was attempted to find out new potential inhibitors of CHIKV nsP2 protease using the ligand-based drug design. Two compounds 10 and 10c, identified by molecular docking, showed antiviral activity against CHIKV with IC₅₀ of 13.1 and 8.3 μM, respectively. Both compounds demonstrated the ability to inhibit the activity of nsP2 in a cell-free assay, and the impact of compound 10 on virus replication was confirmed by western blot. The molecular dynamics study of the interactions of compounds 10 and 10c with CHIKV nsP2 showed that a possible mechanism of action of these compounds is the blocking of the active site and the catalytic dyad of nsP2.

Exposed CendR Domain in Homing Peptide Yields Skin-Targeted Therapeutic in Epidermolysis Bullosa

Systemic skin-selective therapeutics would be a major advancement in the treatment of diseases affecting the entire skin, such as recessive dystrophic epidermolysis bullosa (RDEB), which is caused by mutations in the COL7A1 gene and manifests in transforming growth factor-β (TGF-β)-driven fibrosis and malignant transformation. Homing peptides containing a C-terminal R/KXXR/K motif (C-end rule [CendR] sequence) activate an extravasation and tissue penetration pathway for tumor-specific drug delivery. We have previously described a homing peptide CRKDKC (CRK) that contains a cryptic CendR motif and homes to angiogenic blood vessels in wounds and tumors, but it cannot penetrate cells or tissues. In this study, we demonstrate that removal of the cysteine from CRK to expose the CendR sequence confers the peptide novel ability to home to normal skin. Fusion of the truncated CRK (tCRK) peptide to the C terminus of an extracellular matrix protein decorin (DCN), a natural TGF-β inhibitor, resulted in a skin-homing therapeutic molecule (DCN-tCRK). Systemic DCN-tCRK administration in RDEB mice led to inhibition of TGF-β signaling in the skin and significant improvement in the survival of RDEB mice. These results suggest that DCN-tCRK has the potential to be utilized as a novel therapeutic compound for the treatment of dermatological diseases such as RDEB.

AB0291 RITUXIMAB MAY DELAY THE MOVEMENT OF RHEUMATOID ARTHRITIS PATIENTS ON CARDIORENAL CONTINUUM: RESULTS FROM A PROSPECTIVE OBSERVATIONAL SINGLE-CENTRE COHORT STUDY

Background:

Similarities in risk factors, initial stages, progression and final stage of both atherosclerotic cardiovascular disease (ACVD) and chronic kidney disease (CKD) allowed formulating a concept of cardiorenal continuum.1ACVD and CKD remain the main causes of mortality in rheumatoid arthritis (RA) patients.2,3

Objectives:

To evaluate the effects of rituximab (RTM) therapy on cardiorenal continuum of RA patients.

Methods:

Biologics-naïve RA patients (n=92; age 49.5±9.9) were followed up for 72 months after commencing and continuing RTM therapy (1–10 standard courses) compared with 50 control RA patients (age 49.2±9.8). All control and 63% of RTM patients received methotrexate or leflunomide.

Results:

There were no baseline differences between two groups – Table. At year 6, RTM patients have fewer incidences of hypertension, anxiety/depression, atherosclerosis and diastolic dysfunction than controls. RTM decreased prevalence of albuminuria and CKD.

Table.

Cardiorenal continuum of rheumatoid arthritis patients (%)

FeaturesRituximab groupControl grouppRTM–C1 year n=923 years n=476 years n=311 yearn=503 years n=266 years n=16Risk factorsHypertension52.238.325.8p6–1=0.02250.038.550.0p6=0.032Dyslipidaemia44.636.238.748.046.250.0>0.05Pre-diabetes41.336.241.944.034.656.3>0.05Metabolic syndrome12.06.43.210.07.712.5>0.05Diabetes mellitus3.2002.000>0.05Anxiety/depression78.341.5p3–1=0.00535.3p6–1<0.00176.073.168.8p3=0.009p6=0.008Initial stages (asymptomatic organ damage)Atherosclerosis34.821.312.9p6–1=0.04536.034.637.5p6=0.02Left ventricular hypertrophy8.74.308.07.70>0.05Diastolic dysfunction57.638.322.6p6–1=0.01856.050.056.3p6=0.04Albuminuria19.600p6–1=0.03812.006.3>0.05Kidney impairment6.52.106.000>0.05ProgressionAngina6.5004.000>0.05Chronic kidney disease26.18.59.7p6–1=0.04212.000>0.05End stageMyocardial infarction000000>0.05Stroke000000>0.05Heart failure4.400000>0.05Acute/chronic renal failure000000>0.05Death000000>0.05

There were no significant differences in frequencies of other risk factors, signs of organ damage and cases of established heart, cerebrovascular and renal diseases/complications.

Conclusion:

RTM may be effective in delay of the movement of RA patients on cardiorenal continuum. The clinical implications of RTM for cardiorenal correlations in RA patients need to be confirmed in large-scale clinical outcome trials.

References:

[1]Sarnak MJ, Levey AS. Cardiovascular disease and chronic renal disease: a new paradigm.Am J Kidney Dis2000;35(4, Suppl. 1):117–31.

[2]Avina-Zubieta JA, Choi HK, Sadatsafarvi M,et al.Risk of cardiovascular mortality in patients with rheumatoid arthritis: a meta-analysis of observational studies.Arthritis Rheum2008;59:1690–7.

[3]Gullick NJ, Scott DL. Co-morbidities in established rheumatoid arthritis.Best Pract Res Clin Rheumatol2011;25:469–83.

Disclosure of Interests:

Ilshat Gaisin Speakers bureau: Boehringer Ingelheim, KRKA, Berlin-Chemie Menarini, Sanofi, Larisa Ivanova Speakers bureau: Bayer, Novartis, KRKA, Nikolay Maximov Speakers bureau: Pfizer, KRKA, Rosa Valeeva: None declared, Dilara Yurk: None declared, Anastasia Vedekhina: None declared, Nuriya Garaeva: None declared, Irina Sabelnikova: None declared

SAT0107 BIOLOGIC THERAPY WITH RITUXIMAB DECREASES PREVALENCE OF ANXIETY AND DEPRESSION IN RHEUMATOID ARTHRITIS PATIENTS

Background:

Evidence suggests rheumatoid arthritis (RA) confers an increased risk of psychological morbidity, particularly anxiety and depression, which may affect the subsequent management and treatment adherence.1,2Few studies have studied psychological factors over time in RA patients.3

Objectives:

To evaluate the prevalence of anxiety and depression in RA patients following rituximab treatment.

Methods:

92 biologics-naïve RA patients [mean (SD) age 49.5 (9.9) years, 78 women; median (IQR) DAS28 5.67 (3.94–8.45); median (IQR) HAQ 1.87 (1.2–3.5)] were followed up for 27 months after commencing and continuing rituximab therapy (1, 2, 3 standard courses). Anxiety and depression, and health-related quality of life (HRQoL) were assessed at baseline, 3, 15 and 27 months using the Hospital Anxiety and Depression Scale (HADS) and the Short Form (SF-36 v.1) Health Survey questionnaire, respectively.

Results:

Median anxiety and depression scores decreased significantly between baseline and 3 months and continued depress over the 27-month period – Table. The prevalence of depression cases decreased twice from baseline to 27 months (p<0.01), as did the prevalence of anxiety (p<0.01). Patients reported poor baseline HRQoL. SF-36 domain scores substantially rose after 15 and 27 months.

Anxiety, depression, and quality of lifeBaseline3 months15 months27 months(n=92)(n=92)(n=53)(n=14)Anxiety cases (HADS-A score ≥8), n (%)72 (78.3)48 (52.2)24 (45.3)*5 (35.7)**Median (IQR) Anxiety score12.6 (10–15)8.2 (5–12)*6.4 (3–10)**5.5 (3–8)***Depression cases (HADS-D score ≥8), n (%)62 (67.4)50 (54.3)19 (35.8)*4 (28.6)**Median (IQR) Depression score9.2 (7.8–9.6)5.6 (3–8)**4.5 (2–7)**3.6 (2–6)***Mean (SD) Mental Health score42.8 (15.2)51.2 (18.3)68.7 (11.2)*72.9 (10.5)**Mean (SD) Physical Function score24.4 (8.3)32.5 (9.8)53.8 (10.5)*54.5 (9.3)*Mean (SD) Social Function score48.2 (15.4)56.8 (25.5)59.8 (18.7)65.9 (9.2)*Mean (SD) General Health score35.8 (11.2)48.7 (10.8)67.8 (8.6)**75.9 (12.6)**

* p<0.05, ** p<0.01, *** p<0.001 differences between baseline and follow-up

Conclusion:

Anxiety and depression levels decrease significantly in RA patients following commencement and continuity of rituximab. B cell-directed therapy for patients with RA helps achieve remission of both anxiety and depression, and improves HRQoL.

References:

[1]McWilliams LA, Goodvin RD, Cox BJ. Depression and anxiety associated with three pain conditions: results from a nationally representative sample.Pain2004;111:77–83.

[2]Garcia-Cebrian A, Gandhi P, Demyttenaere K et al. The association of depression and painful physical symptoms: a review of the European literature.Eur Psychiatry2006;21:379–88.

[3]Overman CL, Bossema ER, van Middendorp H et al. The prospective association between psychological distress and disease activity in rheumatoid arthritis: a multilevel regression analysis.Ann Rheum Dis2012;71:192–7.

Disclosure of Interests:

Ilshat Gaisin Speakers bureau: Boehringer Ingelheim, KRKA, Berlin-Chemie Menarini, Sanofi, Larisa Ivanova Speakers bureau: Bayer, Novartis, KRKA, Nikolay Maximov Speakers bureau: Pfizer, KRKA, Anastasia Vedekhina: None declared, Dilara Yurk: None declared, Nuriya Garaeva: None declared

Freshwater salmon aquaculture in Chile and transferable antimicrobial resistance

Large amounts of antimicrobials are used in salmonid aquaculture in Chile. Most are used in marine aquaculture, but appreciable amounts are also employed in freshwater aquaculture. Much research and many publications have examined transferable antimicrobial resistance in bacteria isolated from marine salmon farms, but much less attention has been paid to this area in freshwater salmon farming. A recent paper by Domínguez et al. (2019) has as least in part remedied this situation. We now comment on some of its interpretations and have attempted to point out its areas of strength and weakness in light of the published scientific literature. Seen in this setting, the important results presented by Domínguez et al. (2019) underline the need for increased awareness of the challenge to animal and human health posed by excessive use of antimicrobials in aquaculture.

Human Cord Blood-Derived Unrestricted Somatic Stem Cell Infusion Improves Neurobehavioral Outcome in a Rabbit Model of Intraventricular Hemorrhage

Intraventricular hemorrhage (IVH) is a severe complication of preterm birth, which leads to hydrocephalus, cerebral palsy, and mental retardation. There are no available therapies to cure IVH, and standard treatment is supportive care. Unrestricted somatic stem cells (USSCs) from human cord blood have reparative effects in animal models of brain and spinal cord injuries. USSCs were administered to premature rabbit pups with IVH and their effects on white matter integrity and neurobehavioral performance were evaluated. USSCs were injected either via intracerebroventricular (ICV) or via intravenous (IV) routes in 3 days premature (term 32d) rabbit pups, 24 hours after glycerol‐induced IVH. The pups were sacrificed at postnatal days 3, 7, and 14 and effects were compared to glycerol‐treated but unaffected or nontreated control. Using in vivo live bioluminescence imaging and immunohistochemical analysis, injected cells were found in the injured parenchyma on day 3 when using the IV route compared to ICV where cells were found adjacent to the ventricle wall forming aggregates; we did not observe any adverse events from either route of administration. The injected USSCs were functionally associated with attenuated microglial infiltration, less apoptotic cell death, fewer reactive astrocytes, and diminished levels of key inflammatory cytokines (TNFα and IL1β). In addition, we observed better preservation of myelin fibers, increased myelin gene expression, and altered reactive astrocyte distribution in treated animals, and this was associated with improved locomotor function. Overall, our findings support the possibility that USSCs exert anti‐inflammatory effects in the injured brain mitigating many detrimental consequences associated with IVH. stem cells translational medicine2019;8:1157–1169

Molecular Dynamics Simulations of the Interactions between Glial Cell Line-Derived Neurotrophic Factor Family Receptor GFRα1 and Small-Molecule Ligands

The glial cell line-derived neurotrophic factor (GDNF) family ligands (GFLs) support the survival and functioning of various neuronal populations. Thus, they could be attractive therapeutic agents against a multitude of neurodegenerative diseases caused by progressive death of GFLs responsive neurons. Small-molecule ligands BT13 and BT18 show an effect on GDNF family receptor GFRα1 and RET receptor tyrosine kinase RetA function. Thus, their potential binding sites and interactions were explored in the GDNF-GFRα1-RetA complex using molecular docking calculations as well as molecular dynamics (MD) simulations. Three possible regions were examined: the interface between GDNF and GFRα1 (region A), the RetA interface with GFRα1 (region B), and a possible allosteric site in GFRα1 (region C). The results obtained by the docking calculations and the MD simulations indicate that the preferable binding occurs at the allosteric site. A less preferable binding site was detected on the RetA surface interfacing GFRα1. In the membrane-bound state of RetA this can enable compounds BT13 and BT18 to act as direct RetA agonists. The analysis of the MD simulations shows hydrogen bonds for BT13 and significant hydrophobic interactions with GFRα1 for BT13 and BT18 at the allosteric site.

Cord Blood-Derived Stem Cells Suppress Fibrosis and May Prevent Malignant Progression in Recessive Dystrophic Epidermolysis Bullosa

Recessive dystrophic epidermolysis bullosa (RDEB) is a severe skin fragility disorder caused by mutations in the Col7a1 gene. Patients with RDEB suffer from recurrent erosions in skin and mucous membranes and have a high risk for developing cutaneous squamous cell carcinoma (cSCCs). TGFβ signaling has been associated with fibrosis and malignancy in RDEB. In this study, the activation of TGFβ signaling was demonstrated in col7a1^-/- mice as early as a week after birth starting in the interdigital folds of the paws, accompanied by increased deposition of collagen fibrils and elevated dermal expression of matrix metalloproteinase (MMP)-9 and MMP-13. Furthermore, human cord blood-derived unrestricted somatic stem cells (USSCs) that we previously demonstrated to significantly improve wound healing and prolong the survival of col7a1^-/- mice showed the ability to suppress TGFβ signaling and MMP-9 and MMP-13 expression meanwhile upregulating anti-fibrotic TGFβ3 and decorin. In parallel, we cocultured USSCs in a transwell with RDEB patient-derived fibroblasts, keratinocytes, and cSCC, respectively. The patient-derived cells were constitutively active for STAT, but not TGFβ signaling. Moreover, the levels of MMP-9 and MMP-13 were significantly elevated in the patient derived-keratinocytes and cSCCs. Although USSC coculture did not inhibit STAT signaling, it significantly suppressed the secretion of MMP-9 and MMP-13, and interferon (IFN)-γ from RDEB patient-derived cells. Since epithelial expression of these MMPs is a biomarker of malignant transformation and correlates with the degree of tumor invasion, these results suggest a potential role for USSCs in mitigating epithelial malignancy, in addition to their anti-inflammatory and anti-fibrotic functions. Stem Cells 2018;36:1839-12.

Identification of Natural Compounds against Neurodegenerative Diseases Using In Silico Techniques

The aim of this study was to identify new potentially active compounds for three protein targets, tropomyosin receptor kinase A (TrkA), N-methyl-d-aspartate (NMDA) receptor, and leucine-rich repeat kinase 2 (LRRK2), that are related to various neurodegenerative diseases such as Alzheimer's, Parkinson's, and neuropathic pain. We used a combination of machine learning methods including artificial neural networks and advanced multilinear techniques to develop quantitative structure⁻activity relationship (QSAR) models for all target proteins. The models were applied to screen more than 13,000 natural compounds from a public database to identify active molecules. The best candidate compounds were further confirmed by docking analysis and molecular dynamics simulations using the crystal structures of the proteins. Several compounds with novel scaffolds were predicted that could be used as the basis for development of novel drug inhibitors related to each target.

Efficacy of Human Placental-Derived Stem Cells in Collagen VII Knockout (Recessive Dystrophic Epidermolysis Bullosa) Animal Model

Recessive dystrophic epidermolysis bullosa (RDEB) is a devastating inherited skin blistering disease caused by mutations in the COL7A1 gene that encodes type VII collagen (C7), a major structural component of anchoring fibrils at the dermal-epidermal junction (DEJ). We recently demonstrated that human cord blood-derived unrestricted somatic stem cells promote wound healing and ameliorate the blistering phenotype in a RDEB (col7a1^-/- ) mouse model. Here, we demonstrate significant therapeutic effect of a further novel stem cell product in RDEB, that is, human placental-derived stem cells (HPDSCs), currently being used as human leukocyte antigen-independent donor cells with allogeneic umbilical cord blood stem cell transplantation in patients with malignant and nonmalignant diseases. HPDSCs are isolated from full-term placentas following saline perfusion, red blood cell depletion, and volume reduction. HPDSCs contain significantly higher level of both hematopoietic and nonhematopoietic stem and progenitor cells than cord blood and are low in T cell content. A single intrahepatic administration of HPDSCs significantly elongated the median life span of the col7a1^-/- mice from 2 to 7 days and an additional intrahepatic administration significantly extended the median life span to 18 days. We further demonstrated that after intrahepatic administration, HPDSCs engrafted short-term in the organs affected by RDEB, that is, skin and gastrointestinal tract of col7a1^-/- mice, increased adhesion at the DEJ and deposited C7 even at 4 months after administration of HPDSCs, without inducing anti-C7 antibodies. This study warrants future clinical investigation to determine the safety and efficacy of HPDSCs in patients with severe RDEB. Stem Cells Translational Medicine 2018;7:530-542.

Small-Molecule Ligands as Potential GDNF Family Receptor Agonists

To find out potential GDNF family receptor α1 (GFRα1) agonists, small molecules were built up by molecular fragments according to the structure-based drug design approach. Molecular docking was used to identify their binding modes to the biological target GFRα1 in GDNF-binding pocket. Thereafter, commercially available compounds based on the best predicted structures were searched from ZINC and MolPort databases (similarity ≥ 80%). Five compounds from the ZINC library were tested in phosphorylation and luciferase assays to study their ability to activate GFRα1-RET. A bidental compound with two carboxyl groups showed the highest activity in molecular modeling and biological studies. However, the relative position of these groups was important. The meta-substituted structure otherwise identical to the most active compound 2-[4-(5-carboxy-1H-1,3-benzodiazol-2-yl)phenyl]-1H-1,3-benzodiazole-5-carboxylic acid was inactive. A weaker activity was detected for a compound with a single carboxyl group, that is, 4-(1,3-benzoxazol-2-yl)benzoic acid. The substitution of the carboxyl group by the amino or acetamido group also led to the loss of the activity.

Plasmid-Mediated Quinolone Resistance (PMQR) Genes and Class 1 Integrons in Quinolone-Resistant Marine Bacteria and Clinical Isolates of Escherichia coli from an Aquacultural Area

Antimicrobial usage in aquaculture selects for antimicrobial-resistant microorganisms in the marine environment. The relevance of this selection to terrestrial animal and human health is unclear. Quinolone-resistance genes qnrA, qnrB, and qnrS were chromosomally located in four randomly chosen quinolone-resistant marine bacteria isolated from an aquacultural area with heavy quinolone usage. In quinolone-resistant uropathogenic clinical isolates of Escherichia coli from a coastal area bordering the same aquacultural region, qnrA was chromosomally located in two E. coli isolates, while qnrB and qnrS were located in small molecular weight plasmids in two other E. coli isolates. Three quinolone-resistant marine bacteria and three quinolone-resistant E. coli contained class 1 integrons but without physical association with PMQR genes. In both marine bacteria and uropathogenic E. coli, class 1 integrons had similar co-linear structures, identical gene cassettes, and similarities in their flanking regions. In a Marinobacter sp. marine isolate and in one E. coli clinical isolate, sequences immediately upstream of the qnrS gene were homologous to comparable sequences of numerous plasmid-located qnrS genes while downstream sequences were different. The observed commonality of quinolone resistance genes and integrons suggests that aquacultural use of antimicrobials might facilitate horizontal gene transfer between bacteria in diverse ecological locations.

Effect of primary processing on the distribution of free and modified Fusarium mycotoxins in naturally contaminated oats

Oat (Avena sativa L.) ranks seventh in the world cereal production and is considered to be an important source for many valuable components of nutritional and biological importance, i.e. proteins, fats, carbohydrates, fibre, minerals and vitamins. Because of these properties the amount of oat used for human consumption has increased progressively during the last years. Unfortunately, the quality of this grain crop is often compromised by mycotoxin contamination, which is relatively ubiquitous despite efforts to control the problem. Therefore, it is important to investigate the distribution pattern of mycotoxins and their conjugated derivatives in contaminated oat grains. For this purpose we have developed a state-of-the-art multi-mycotoxin high-resolution mass spectrometry method and analysed oat samples for their content of the most important mycotoxins commonly occurring in Norwegian cereal grain. Quantitative mapping of selected Fusarium free and modified mycotoxins was performed in fractions collected during processing trials consisting of dehulling and sequential pearling. Both the derivative free mycotoxins and their metabolites were mainly present in the hulls compared to the oat kernel, thus dehulling resulted in a significant reduction of the total mycotoxin load, followed by some further reduction by pearling. Furthermore, free and modified mycotoxins were unevenly distributed in relation to each other throughout the grain fractions, showing a shift towards glucosidated forms, such as deoxynivalenol-3-glucoside and HT-2-3-glucoside in the oat kernel, which highlights potential food safety concerns associated with in planta modified mycotoxins.

Chronic Liver Diseases and Parenterally Transmitted Hepatitis Viruses

Hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis D virus (HDV) are the leading cause of chronic liver diseases. The aims of the present study are to determine the etiological relationship of HBV and HCV in patients with chronic liver disease in North-Eastern Bulgaria and prevalence of dual and triple infections. A total of 434 patients were investigated for HBsAg, 402 of whom were also tested for anti-HCV. The HBsAg positive subjects were tested for anti-HDV and 32 of them also for HbeAg/anti-Hbe. Separated commercial ELISA kits were used. HBsAg was detected in 132 (30.4%); 10.6% were co-infected with HDV. Anti-HCV was detected in 15.4%. Five of 132 HbsAg positive patients (3.78%) were simultaneously HBV and HCV positive. Two patients out of 132 (1.52%) were positive to HBV, HCV and HDV. Our data indicate that HBV infection was the main cause of chronic liver diseases in North-Eastern Bulgaria, and 10.6% of the patients suffered from severe disease because of co-infection with HDV. HCV plays the same role in 15.4% of the cases. Recently, we observed dually infected (HBV and HCV) and triple infected (HBV, HCV, HDV) patients suffering from severe chronic liver diseases.

Rescue of the mucocutaneous manifestations by human cord blood derived nonhematopoietic stem cells in a mouse model of recessive dystrophic epidermolysis bullosa

Recessive dystrophic epidermolysis bullosa (RDEB) is a severe skin blistering disease caused by mutations in COL7A1-encoding type VII collagen (C7). Currently, there is no curative therapy for patients with RDEB. Our previous studies demonstrated that human umbilical cord blood (HUCB) derived unrestricted somatic stem cells (USSCs) express C7 and facilitate wound healing in a murine wounding model. The primary objective of this study is to investigate the therapeutic functions of USSCs in the C7 null (Col7a1(-/-) ) C57BL6/J mice, a murine model of RDEB. We demonstrated that intrahepatic administration of USSCs significantly improved the blistering phenotype and enhanced the life span in the recipients. The injected USSCs trafficked to the sites of blistering and were incorporated in short-term in the recipients' skin and gastrointestinal tract. Consistent with an overall histological improvement in the epidermal-dermal adherence following USSC treatment, the expression of C7 at the basement membrane zone was detected and the previously disorganized integrin α6 distribution was normalized. We also demonstrated that USSCs treatment induced an infiltration of macrophages with a regenerative "M2" phenotype. Our data suggest that HUCB-derived USSCs improved the RDEB phenotype through multiple mechanisms. This study has warranted future clinical investigation of USSCs as a novel and universal allogeneic stem cell donor source in selected patients with RDEB.

Antimicrobial resistance genes in marine bacteria and human uropathogenic Escherichia coli from a region of intensive aquaculture

Antimicrobials are heavily used in Chilean salmon aquaculture. We previously found significant differences in antimicrobial-resistant bacteria between sediments from an aquaculture and a non-aquaculture site. We now show that levels of antimicrobial resistance genes (ARG) are significantly higher in antimicrobial-selected marine bacteria than in unselected bacteria from these sites. While ARG in tetracycline- and florfenicol-selected bacteria from aquaculture and non-aquaculture sites were equally frequent, there were significantly more plasmid-mediated quinolone resistance genes per bacterium and significantly higher numbers of qnrB genes in quinolone-selected bacteria from the aquaculture site. Quinolone-resistant urinary Escherichia coli from patients in the Chilean aquacultural region were significantly enriched for qnrB (including a novel qnrB gene), qnrS, qnrA and aac(6')-1b, compared with isolates from New York City. Sequences of qnrA1, qnrB1 and qnrS1 in quinolone-resistant Chilean E. coli and Chilean marine bacteria were identical, suggesting horizontal gene transfer between antimicrobial-resistant marine bacteria and human pathogens.

Plasmid-related quinolone resistance determinants in epidemic Vibrio parahaemolyticus, uropathogenic Escherichia coli, and marine bacteria from an aquaculture area in Chile

Marine bacteria from aquaculture areas with industrial use of quinolones have the potential to pass quinolone resistance genes to animal and human pathogens. The VPA0095 gene, related to the quinolone resistance determinant qnrA, from clinical isolates of epidemic Vibrio parahaemolyticus conferred reduced susceptibility to quinolone after cloning into Escherichia coli K-12 either when acting alone or synergistically with DNA gyrase mutations. In addition, a plasmid-mediated quinolone resistance gene from marine bacteria, aac(6')-Ib-cr, was identical to aac(6')-Ib-cr from urinary tract isolates of E. coli, suggesting a recent flow of this gene between these bacteria isolated from different environments. aac(6')-Ib-cr from E. coli also conferred reduced susceptibility to quinolone and kanamycin when cloned into E. coli K-12.

Presence of enniatin B and its hepatic metabolites in plasma and liver samples from broilers and eggs from laying hens

Enniatins, a large group of cyclodepsipeptides, are widely distributed contaminants of different crops intended for human and animal consumption. Enniatin B is one of the principal analogues in species of the genus Fusarium, known to have ionophoric, antibiotic, and insecticidal activity. Regardless of considerable cytotoxic effects observed in vitro, enniatins have been characterised as compounds with low acute toxicity in vivo. The biotransformation of enniatin B has previously been elucidated in liver microsomes, and 12 different metabolites (M1 to M12) have been reported. In order to provide a better basis for understanding the potential toxic effects in humans and animals, different samples (eggs, livers, plasma) from two different feeding studies have been analysed for the presence of enniatin B and its hepatic metabolites. The earlier reported metabolite M11, and a novel metabolite (designated M13), were dominant in liver samples from enniatin B exposed broilers. The peak area corresponding to the sodiated molecular ion of M11 was approximately 2.5 times larger than that of parent enniatin B in liver samples collected after one week of exposure. The same metabolites were also present in serum samples. In egg samples, only metabolites M13 and M4 were detected. The comparison of mass spectrometric data of M13 and enniatin B suggested that M13 is a monohydroxylated metabolite. The hepatic biotransformation of enniatin B was also investigated in vitro in chicken microsomes demonstrating good correlation with the metabolite profiles in the chicken samples. The results of the present study demonstrated an extensive biotransformation of enniatin B in vivo confirming previously reported in vitro data.

Serologic Hepatitis B Virus Immunity in Health Care Workers

Health care workers (HCWs) are at high risk of blood borne infections including Hepatitis B virus (HBV) infection. HBV vaccination is recommended for HCWs but post vaccination testing of immune response (anti-HBs) is not routinely performed. In our study information on immune response after the first immunization schedule of HCWs is not available. By reason of the questions regarding long lasting immunity, we decided to assess the anti-HBs of HCWs who wished to check immune response after different times of vaccination and also unvaccinated persons in St. Marina University Hospital, Varna, Bulgaria. After informed consent, 341 HCWs were investigated. They were divided into 3 groups according to their status: Group A had no history of vaccination against HBV, Group B had no complete vaccination schedule and Group C had complete vaccination data. Of Group C, 32 had been vaccinated more than 10 years previously, 111 - 10–5 years previously and 48 - < 5 years previously. Quantitative detection of antibody to HBsAg (anti-HBs) by commercial ELISA was carried out. A total, positive immune response was detected in 35.6% (group A), 66.2% (group B) and 80.1% (group C) of HCWs investigated. Of Group C positive immune response was detected in 68.7%, 81.1% and 85.4% respectively of the time of vaccination. Detectable anti-HB was found in HCWs without HBV immunization, probably after unknown exposure to HBV. The lack of information regarding immune response after the first immunization schedule makes the interpretation of no detectible anti-HBs level 5–10 years post-immunization difficult. For the HCWs with anti-HBs loss, counseling for booster vaccine dose and consequent testing is mandatory.

Antimicrobial use in aquaculture re-examined: its relevance to antimicrobial resistance and to animal and human health

The worldwide growth of aquaculture has been accompanied by a rapid increase in therapeutic and prophylactic usage of antimicrobials including those important in human therapeutics. Approximately 80% of antimicrobials used in aquaculture enter the environment with their activity intact where they select for bacteria whose resistance arises from mutations or more importantly, from mobile genetic elements containing multiple resistance determinants transmissible to other bacteria. Such selection alters biodiversity in aquatic environments and the normal flora of fish and shellfish. The commonality of the mobilome (the total of all mobile genetic elements in a genome) between aquatic and terrestrial bacteria together with the presence of residual antimicrobials, biofilms, and high concentrations of bacteriophages where the aquatic environment may also be contaminated with pathogens of human and animal origin can stimulate exchange of genetic information between aquatic and terrestrial bacteria. Several recently found genetic elements and resistance determinants for quinolones, tetracyclines, and β-lactamases are shared between aquatic bacteria, fish pathogens, and human pathogens, and appear to have originated in aquatic bacteria. Excessive use of antimicrobials in aquaculture can thus potentially negatively impact animal and human health as well as the aquatic environment and should be better assessed and regulated.

Salmon aquaculture and antimicrobial resistance in the marine environment

Antimicrobials used in salmon aquaculture pass into the marine environment. This could have negative impacts on marine environmental biodiversity, and on terrestrial animal and human health as a result of selection for bacteria containing antimicrobial resistance genes. We therefore measured the numbers of culturable bacteria and antimicrobial-resistant bacteria in marine sediments in the Calbuco Archipelago, Chile, over 12-month period at a salmon aquaculture site approximately 20 m from a salmon farm and at a control site 8 km distant without observable aquaculture activities. Three antimicrobials extensively used in Chilean salmon aquaculture (oxytetracycline, oxolinic acid, and florfenicol) were studied. Although none of these antimicrobials was detected in sediments from either site, traces of flumequine, a fluoroquinolone antimicrobial also widely used in Chile, were present in sediments from both sites during this period. There were significant increases in bacterial numbers and antimicrobial-resistant fractions to oxytetracycline, oxolinic acid, and florfenicol in sediments from the aquaculture site compared to those from the control site. Interestingly, there were similar numbers of presumably plasmid-mediated resistance genes for oxytetracycline, oxolinic acid and florfenicol in unselected marine bacteria isolated from both aquaculture and control sites. These preliminary findings in one location may suggest that the current use of large amounts of antimicrobials in Chilean aquaculture has the potential to select for antimicrobial-resistant bacteria in marine sediments.

Lysosomes as a possible target of enniatin B-induced toxicity in Caco-2 cells

Enniatins are cyclic hexadepsipeptidic mycotoxins with ionophoric, antibiotic, and insecticidal activity. Enniatin B (EnnB), the most important analogue, is produced by many Fusarium species and is a common contaminant in grain-based foods. The compound's cytotoxic potential has been shown in different experiments; however, the mode of action has not been detailed so far. In the present study, several mutually confirmative experiments have been performed indicating that EnnB-initiated cytotoxicity could be connected with lysosomal membrane permeabilization (LMP). Lysosomal functionality, as assessed by the Neutral Red assay, was already affected after 3 h of toxin exposure. After 24 h, cell proliferation was decreased, and there was indication for a cell cycle arrest in the G(2)/M phase leading to the initiation of apoptosis or necrosis. Intracellular ROS-production was observed. However, antioxidants did not alter the observed EnnB-induced loss of lysosomal functionality leading to the conclusion that ROS was not an initial factor but one produced later in the event cascade. The collected data suggested that lysosomal destabilization is an upstream event in EnnB-initiated cytotoxicity followed by a certain extent of translocation of cathepsins into the cytosol, which was observed using immunological and proteomic methods. It appeared that cell death induced by EnnB was delayed and occurred not as a massive lysosomal breakdown but was probably progressing and leading to partial and selective LMP, starting a nonapoptotic cell death pathway with morphological features that had been previously considered as necrotic. The molecular mechanism of EnnB-triggered lysosomal destabilization, and the cellular processes leading to mitochondrial permeabilization and cell death are still unknown. They may, however, be connected to the compound's ionophoric properties.

Enniatin B1 is a substrate of intestinal P-glycoprotein, multidrug resistance-associated protein 2 and breast cancer resistance protein

Enniatins are cyclic hexadepsipeptides produced by various fungi, known to have ionophoric, antibiotic and insecticidal activity. The aim of the present study was to evaluate the intestinal absorption characteristics of enniatin B1 (ENN-B1). Using the human intestinal Caco-2 cell line, we found that the permeability of ENN-B1 in the basolateral to apical direction was 6.7× higher as compared to the permeability in the opposite direction, indicating involvement of apically located transporters. Transport of ENN-B1 in the apical to basolateral direction was increased significantly upon treatment of Caco-2 cells with the P-glycoprotein (Pgp) inhibitor verapamil and the multidrug resistance-associated protein 2 (MRP2) inhibitor MK571, but only weakly and not significantly after treatment with the breast cancer resistance protein (BCRP) inhibitor fumitremorgin C. Additionally, MDCK II cells over-expressing Pgp, MRP2 or BCRP, showed reduced sensitivity towards ENN-B1. These data demonstrate for the first time that ENN-B1 is a substrate of MRP2 and suggests that Pgp, MRP2 and possibly BCRP are involved in transport of ENN-B1 across the intestine.

Prognostic significance of hepatocyte growth factor and microvessel bone marrow density in patients with chronic myeloid leukaemia

OBJECTIVE

The aims of the study were: (1) to perform a complex angiogenic assessment in chronic myeloid leukaemia (CML) patients using multiple parameters: bone marrow microvessel density (MVD), bone marrow immunohistochemical cellular expressions of vascular endothelial growth factor (VEGF) and its receptor KDR, as well as hepatocyte growth factor (HGF) and its receptor MET, and the plasma VEGF and HGF; and (2) to determine the clinical significance of these factors for patients with CML.

MATERIAL AND METHODS

The VEGF and HGF plasma levels were analysed by ELISA in 38 newly diagnosed CML patients. Immunohistochemical methods were used to visualize the MVD as well as the cellular VEGF/KDR and HGF/MET expression.

RESULTS

We found an increased MVD, cellular VEGF/KDR and HGF/MET expression and elevated plasma VEGF and HGF in CML patients. The plasma HGF, cellular HGF and MET expression correlated with the CML phase. The plasma HGF correlated with all markers reflecting the tumour burden (leucocytes, blast percentage, splenomegaly and LDH) as well as with the phase of CML and overall survival of the patients. Cox regression analysis determined the prognostic relevance of HGF and MVD parameters, but not for the plasma VEGF and cellular VEGF and KDR.

CONCLUSIONS

Using a complex angiogenic assessment we determined an increased angiogenesis in CML patients. No prognostic relevance was found for VEGF plasma levels or VEGF/KDR cellular bone marrow expression. The increased cellular HGF and MET expressions could be considered high-risk factors for these patients. Plasma HGF and MVD were shown to be independent prognostic parameters for patients' survival.

Self-organized formation of GaSb/GaAs quantum rings

Ring-shaped GaSb/GaAs quantum dots, grown by molecular beam epitaxy, were studied using cross-sectional scanning tunneling microscopy. These quantum rings have an outer shape of a truncated pyramid with baselengths around 15 nm and heights of about 2 nm but are characterized by a clear central opening extending over about 40% of the outer baselength. They form spontaneously during the growth and subsequent continuous capping of GaSb/GaAs quantum dots due to the large strain and substantial As-for-Sb exchange reactions leading to strong Sb segregation.

2-Amino-14,16-dimethyloctadecan-3-ol: in vitro bioactivity and bio-production by the fungus Fusarium avenaceum

2-Amino-14,16-dimethyloctadecan-3-ol (2-AOD-3-ol) belongs to the class of sphingosine analogue toxins, which is a class of toxins that is known among several fungal genera and some lower marine animals. Many sphingosine analogues have been shown to inhibit ceramide synthase through structural similarities with the substrates of the enzyme. The adverse effects of some analogues, e.g. the fumonisins, are a result of ceramide synthase inhibition. The primary aim of this work was to generate basic knowledge on the toxicity of 2-AOD-3-ol in vitro. The human hepatocarcinoma cell line Hep G2 and horse erythrocytes were used in order to achieve this aim. The second aim of this work was to gain insight into the capabilities of the fungus Fusarium avenaceum, a common contaminant of grain in Scandinavia, to produce the toxin under laboratory conditions on different grain species, and in the field. The metabolite was found to be cytotoxic in several assays (lower µM-range) that measure general cytotoxicity (Alamar Blue" assay, Neutral Red uptake, LDH leakage), but did not inhibit ceramide synthase as measured by the increase of the sphinganine/sphingosine ratio. The cellular membrane was likewise not found to be a primary target of the molecule. Strains of F. avenaceum produced up to 6.3 mg/g of 2-AOD-3-ol on wheat grain under controlled conditions in the laboratory, while only low amounts (<56 µg/kg) could be found in field samples.