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1.
Fish Shellfish Immunol ; 145: 109319, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38145782

ABSTRACT

The thymus is a sophisticated primary lymphoid organ in jawed vertebrates, but knowledge on teleost thymus remains scarce. In this study, for the first time in the European sea bass, laser capture microdissection was leveraged to collect two thymic regions based on histological features, namely the cortex and the medulla. The two regions were then processed by RNAseq and in-depth functional transcriptome analyses with the aim of revealing differential gene expression patterns and gene sets enrichments, ultimately unraveling unique microenvironments imperative for the development of functional T cells. The sea bass cortex emerged as a hub of T cell commitment, somatic recombination, chromatin remodeling, cell cycle regulation, and presentation of self antigens from autophagy-, proteasome- or proteases-processed proteins. The cortex therefore accommodated extensive thymocyte proliferation and differentiation up to the checkpoint of positive selection. The medulla instead appeared as the center stage in autoimmune regulation by negative selection and deletion of autoreactive T cells, central tolerance mechanisms and extracellular matrix organization. Region-specific canonical markers of T and non-T lineage cells as well as signals for migration to/from, and trafficking within, the thymus were identified, shedding light on the highly coordinated and exquisitely complex bi-directional interactions among thymocytes and stromal components. Markers ascribable to thymic nurse cells and poorly characterized post-aire mTEC populations were found in the cortex and medulla, respectively. An in-depth data mining also exposed previously un-annotated genomic resources with differential signatures. Overall, our findings contribute to a broader understanding of the relationship between regional organization and function in the European sea bass thymus, and provide essential insights into the molecular mechanisms underlying T-cell mediated adaptive immune responses in teleosts.


Subject(s)
Bass , Endocrine Glands , Animals , Thymus Gland , T-Lymphocytes , Gene Expression Profiling
2.
Fish Shellfish Immunol ; 142: 109099, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37734650

ABSTRACT

The NK-lysin antimicrobial peptide, first identified in mammals, possesses both antibacterial and cytotoxic activity against cancer cell lines. Homologue peptides isolated from different fish species have been examined for their functional characteristics in the last few years. In this study, a NK-lysin transcript was identified in silico from the head kidney transcriptome of the Antarctic teleost Trematomus bernacchii. The corresponding amino acid sequence, slightly longer than NK-lysins of other fish species, contains six cysteine residues that in mammalian counterparts form three disulphide bridges. Real time-PCR analysis indicated its predominant expression in T. bernacchii immune-related organs and tissues, with greatest mRNA abundance detected in gills and spleen. Instead of focusing on the full T. bernacchii derived NK-lysin mature molecule, we selected a 27 amino acid residue peptide (named NKL-WT), corresponding to the potent antibiotic NK-2 sequence found in human NK-lysin. Moreover, we designed a mutant peptide (named NKL-MUT) in which two alanine residues substitute the two cysteines found in the NKL-WT. The two peptides were obtained by solid phase organic synthesis to investigate their functional features. NKL-WT and NKL-MUT displayed antibacterial activity against the human pathogenic bacterium Enterococcus faecalis and the ESKAPE pathogen Acinetobacter baumannii, respectively. Moreover, at the determined Minimum Inhibitory Concentration and Minimum Bactericidal Concentration values against these pathogens, both peptides showed high selectivity as they did not exhibit any haemolytic activity on erythrocytes or cytotoxic activity against mammalian primary cell lines. Finally, the NKL-MUT selectively triggers the killing of the melanoma cell line B16F10 by means of a pro-apoptotic pathway at a concentration range in which no effects were found in normal mammalian cell lines. In conclusion, the two peptides could be considered as promising candidates in the fight against antibiotic resistance and tumour proliferative action, and also be used as innovative adjuvants, either to decrease chemotherapy side effects or to enhance anticancer drug activity.


Subject(s)
Fish Proteins , Perciformes , Humans , Animals , Antarctic Regions , Fish Proteins/genetics , Fish Proteins/chemistry , Peptides , Anti-Bacterial Agents/pharmacology , Perciformes/genetics , Perciformes/metabolism , Proteolipids/genetics , Proteolipids/chemistry , Fishes/metabolism , Mammals/metabolism
3.
Acta Haematol ; 2023 Nov 14.
Article in English | MEDLINE | ID: mdl-37963436

ABSTRACT

INTRODUCTION: Tumor lysis syndrome (TLS) occurs frequently during induction therapy for acute lymphoblastic leukemia (ALL). Patients are categorized into intermediate or high risk based on lactate dehydrogenase (LDH) value and white blood cell (WBC) count according to an expert panel, although no effort has been made to analyze TLS in ALL and its potential consequences. METHODS: We retrospectively analyzed TLS, variables associated with its occurrence and its impact in overall survival and mortality during induction in a cohort of ALL patients in their first induction regimen. RESULTS: A total of 138 patients were included. 52.9% were male and median age at diagnosis was 34 years. Most of them were treated with Hyper-CVAD (39.1%) or a modified CALGB 10403 regimen (37.7%). TLS was identified in 42 patients (30.4%), and half of them fulfilled criteria for clinical TLS (C-TLS). Median overall survival (OS) was the lowest in C-TLS patients. An LDH 3 times greater its upper normal limit (ULN) value and a WBC count equal or greater than 50✕109/l were associated with TLS development, and being male, hyperuricemia and an LDH 3 times greater its ULN value were associated with C-TLS development. C-TLS and AKI were associated with excess mortality during induction. CONCLUSION: TLS was identified in almost a third of ALL patients during induction therapy. Different thresholds for LDH value and WBC count as well as other variables that could identify patients at risk to developing this complication, which is associated with shorter OS. C-TLS confers a higher risk for mortality during induction.

4.
J Biol Chem ; 297(4): 101227, 2021 10.
Article in English | MEDLINE | ID: mdl-34562451

ABSTRACT

TMPRSS13, a member of the type II transmembrane serine protease (TTSP) family, harbors four N-linked glycosylation sites in its extracellular domain. Two of the glycosylated residues are located in the scavenger receptor cysteine-rich (SRCR) protein domain, while the remaining two sites are in the catalytic serine protease (SP) domain. In this study, we examined the role of N-linked glycosylation in the proteolytic activity, autoactivation, and cellular localization of TMPRSS13. Individual and combinatory site-directed mutagenesis of the glycosylated asparagine residues indicated that glycosylation of the SP domain is critical for TMPRSS13 autoactivation and catalytic activity toward one of its protein substrates, the prostasin zymogen. Additionally, SP domain glycosylation-deficient TMPRSS13 displayed impaired trafficking of TMPRSS13 to the cell surface, which correlated with increased retention in the endoplasmic reticulum. Importantly, we showed that N-linked glycosylation was a critical determinant for subsequent phosphorylation of endogenous TMPRSS13. Taken together, we conclude that glycosylation plays an important role in regulating TMPRSS13 activation and activity, phosphorylation, and cell surface localization.


Subject(s)
Cell Membrane/enzymology , Enzyme Precursors/metabolism , Membrane Proteins/metabolism , Protein Processing, Post-Translational , Proteolysis , Serine Endopeptidases/metabolism , Animals , COS Cells , Cell Membrane/genetics , Chlorocebus aethiops , Enzyme Precursors/genetics , HEK293 Cells , Humans , Membrane Proteins/genetics , Protein Domains , Protein Transport/genetics , Serine Endopeptidases/genetics
5.
Biol Chem ; 403(10): 969-982, 2022 09 27.
Article in English | MEDLINE | ID: mdl-35796294

ABSTRACT

TMPRSS13 is a member of the type II transmembrane serine protease (TTSP) family. Here we characterize a novel post-translational mechanism important for TMPRSS13 function: proteolytic cleavage within the extracellular TMPRSS13 stem region located between the transmembrane domain and the first site of N-linked glycosylation at asparagine (N)-250 in the scavenger receptor cysteine rich (SRCR) domain. Importantly, the catalytic competence of TMPRSS13 is essential for stem region cleavage, suggesting an autonomous mechanism of action. Site-directed mutagenesis of the 10 basic amino acids (four arginine and six lysine residues) in this region abrogated zymogen activation and catalytic activity of TMPRSS13, as well as phosphorylation, cell surface expression, and shedding. Mutation analysis of individual arginine residues identified R223, a residue located between the low-density lipoprotein receptor class A domain and the SRCR domain, as important for stem region cleavage. Mutation of R223 causes a reduction in the aforementioned functional processing steps of TMPRSS13. These data provide further insight into the roles of different post-translational modifications as regulators of the function and localization of TMPRSS13. Additionally, the data suggest the presence of complex interconnected regulatory mechanisms that may serve to ensure the proper levels of cell-surface and pericellular TMPRSS13-mediated proteolysis under homeostatic conditions.


Subject(s)
Membrane Proteins , Protein Processing, Post-Translational , Arginine/metabolism , Enzyme Precursors/metabolism , Membrane Proteins/metabolism , Proteolysis
6.
Biochemistry ; 60(5): 373-380, 2021 02 09.
Article in English | MEDLINE | ID: mdl-33475337

ABSTRACT

DNA polymerases play vital roles in the maintenance and replication of genomic DNA by synthesizing new nucleotide polymers using nucleoside triphosphates as substrates. Deoxynucleoside triphosphates (dNTPs) are the canonical substrates for DNA polymerases; however, some bacterial polymerases have been demonstrated to insert deoxynucleoside diphosphates (dNDPs), which lack a third phosphate group, the γ-phosphate. Whether eukaryotic polymerases can efficiently incorporate dNDPs has not been investigated, and much about the chemical or structural role played by the γ-phosphate of dNTPs remains unknown. Using the model mammalian polymerase (Pol) ß, we examine how Pol ß incorporates a substrate lacking a γ-phosphate [deoxyguanosine diphosphate (dGDP)] utilizing kinetic and crystallographic approaches. Using single-turnover kinetics, we determined dGDP insertion across a templating dC by Pol ß to be drastically impaired when compared to dGTP insertion. We found the most significant impairment in the apparent insertion rate (kpol), which was reduced 32000-fold compared to that of dGTP insertion. X-ray crystal structures revealed similar enzyme-substrate contacts for both dGDP and dGTP. These findings suggest the insertion efficiency of dGDP is greatly decreased due to impairments in polymerase chemistry. This work is the first instance of a mammalian polymerase inserting a diphosphate nucleotide and provides insight into the nature of polymerase mechanisms by highlighting how these enzymes have evolved to use triphosphate nucleotide substrates.


Subject(s)
DNA Polymerase beta/chemistry , Deoxyguanine Nucleotides/chemistry , DNA/chemistry , DNA Polymerase beta/metabolism , DNA-Directed DNA Polymerase/metabolism , Deoxyguanine Nucleotides/metabolism , Deoxyguanosine/chemistry , Diphosphates/chemistry , Humans , Kinetics , Substrate Specificity
7.
Plant Biotechnol J ; 19(5): 1008-1021, 2021 05.
Article in English | MEDLINE | ID: mdl-33314563

ABSTRACT

Carotenoids are lipophilic plastidial isoprenoids highly valued as nutrients and natural pigments. A correct balance of chlorophylls and carotenoids is required for photosynthesis and therefore highly regulated, making carotenoid enrichment of green tissues challenging. Here we show that leaf carotenoid levels can be boosted through engineering their biosynthesis outside the chloroplast. Transient expression experiments in Nicotiana benthamiana leaves indicated that high extraplastidial production of carotenoids requires an enhanced supply of their isoprenoid precursors in the cytosol, which was achieved using a deregulated form of the main rate-determining enzyme of the mevalonic acid (MVA) pathway. Constructs encoding bacterial enzymes were used to convert these MVA-derived precursors into carotenoid biosynthetic intermediates that do not normally accumulate in leaves, such as phytoene and lycopene. Cytosolic versions of these enzymes produced extraplastidial carotenoids at levels similar to those of total endogenous (i.e. chloroplast) carotenoids. Strategies to enhance the development of endomembrane structures and lipid bodies as potential extraplastidial carotenoid storage systems were not successful to further increase carotenoid contents. Phytoene was found to be more bioaccessible when accumulated outside plastids, whereas lycopene formed cytosolic crystalloids very similar to those found in the chromoplasts of ripe tomatoes. This extraplastidial production of phytoene and lycopene led to an increased antioxidant capacity of leaves. Finally, we demonstrate that our system can be adapted for the biofortification of leafy vegetables such as lettuce.


Subject(s)
Biofortification , Carotenoids , Chloroplasts , Plant Leaves , Plastids
8.
Fish Shellfish Immunol ; 108: 94-108, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33285171

ABSTRACT

In this review, we summarize and discuss the trends and supporting findings in scientific literature on the gut mucosa immune role in European sea bass (Dicentrarchus labrax L.). Overall, the purpose is to provide an updated overview of the gastrointestinal tract functional regionalization and defence barriers. A description of the available information regarding immune cells found in two immunologically-relevant intestinal compartments, namely epithelium and lamina propria, is provided. Attention has been also paid to mucosal immunoglobulins and to the latest research investigating gut microbiota and dietary manipulation impacts. Finally, we review oral vaccination strategies, as a safe method for sea bass vaccine delivery.


Subject(s)
Adaptive Immunity , Bass/immunology , Gastrointestinal Tract/immunology , Immunity, Innate , Animals
9.
J Insect Sci ; 21(2)2021 Mar 01.
Article in English | MEDLINE | ID: mdl-33822129

ABSTRACT

The salivary glands of insects play a key role in the replication cycle and vectoring of viral pathogens. Consequently, Musca domestica (L.) (Diptera: Muscidae) and the Salivary Gland Hypertrophy Virus (MdSGHV) serve as a model to study insect vectoring of viruses. A better understanding of the structural changes of the salivary glands by the virus will help obtain a better picture of the pathological impact the virus has on adult flies. The salivary glands are a primary route for viruses to enter a new host. As such, studying the viral effect on the salivary glands is particularly important and can provide insights for the development of strategies to control the transmission of vector-borne diseases, such as dengue, malaria, Zika, and chikungunya virus. Using scanning and transmission electron microscopic techniques, researchers have shown the effects of infection by MdSGHV on the salivary glands; however, the exact location where the infection was found is unclear. For this reason, this study did a close examination of the effects of the hypertrophy virus on the salivary glands to locate the specific sites of infection. Here, we report that hypertrophy is present mainly in the secretory region, while other regions appeared unaffected. Moreover, there is a disruption of the cuticular, chitinous lining that separates the secretory cells from the lumen of the internal duct, and the disturbance of this lining makes it possible for the virus to enter the lumen. Thus, we report that the chitinous lining acts as an exit barrier of the salivary gland.


Subject(s)
Houseflies/virology , Insect Viruses/pathogenicity , Salivary Glands/pathology , Animals , Muscidae/virology , Salivary Glands/ultrastructure , Salivary Glands/virology
10.
J Appl Toxicol ; 40(8): 1113-1130, 2020 08.
Article in English | MEDLINE | ID: mdl-32266738

ABSTRACT

Regarding carcinogenicity testing, the long-term rodent bioassay (RCB) has been the test required by most regulatory agencies across the world. Nonetheless, due to the lack of knowledge about its specificity, it has been argued that the RCB is unspecific or even invalid. Because of the substantial limitations of epidemiology to identify chemicals probably not carcinogenic to humans (PNCH), it has been very difficult to address the specificity of the RCB. Nevertheless, because mechanistic/pharmacological data are currently recognized as a valid stream of evidence for the identification of chemical hazards, the road is now open to gain insight into the specificity of the RCB. Based on sound mechanistic/pharmacological data that support the classification of chemicals as PNCH, 100 PNCH substances were gathered in this investigation. Contrary to what was previously forecast, in this study, the RCB exhibited a functional specificity that ranged from 83% to 91%, depending on the settings of the testing (2-species vs. rats only, and the nominal maximum tolerated dose). Other contributions of this work were: (a) enabling the comparison, in terms of specificity, between the RCB and the alternative methods that could replace it (eg, Tg.AC mouse, rasH2 mouse); (b) disclosing what the specificity is for alternative methods that were developed using the RCB as the reference standard; and (c) expanding the previous narrow (only seven substances) set of chemicals identified as not likely to be carcinogenic to humans by hazard identification programs.


Subject(s)
Biological Assay/methods , Carcinogenicity Tests/methods , Cosmetics/toxicity , Excipients/toxicity , Food Additives/toxicity , Species Specificity , Animals , Humans , Mice , Rats
11.
Toxicol Mech Methods ; 30(6): 462-475, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32338171

ABSTRACT

The long-term rodent bioassay (RCB) has been the gold-standard for the pre-marketing prediction of chemical and drug carcinogenicity to humans. Nonetheless, the validity of this toxicity test has remained elusive for several decades. In the quest to uncover the performance of the RCB, its sensitivity (SEN) was charted as the first step. This appraisal was based on (a) chemicals with sufficient epidemiological evidence of carcinogenicity, and (b) other substances with limited epidemiological evidence, or remarkable classifications of carcinogenicity based on mechanistic or pharmacological data. In the present study, chemicals evaluated for their carcinogenicity to humans in IARC Monographs volumes 1-123, U.S. EPA IRIS Assessments, and U.S. NTP RoC were considered. This investigation gathered additional evidence supporting that, in hazard identification, the RCB is unwarranted for mutagenic or direct-acting genotoxicants. However, for purposes of risk assessment or management, the RCB might be justified whenever there is a lack of reliable and/or comprehensive epidemiological data. The RCB exhibited a significantly different SEN for threshold-based human carcinogens compared to non-threshold-based ones. With threshold-based chemicals, to increase the SEN of the testing from 80% (rat-RCB) to 90%, the 2-species RCB might be warranted. Nevertheless, the resolve would depend on the viewpoint, and on the future analysis of the overall performance of the RCB. In terms of SEN, and cancer hazard identification, the comparison between the RCB and alternative methods (e.g. rasH2 mouse, Tg.AC mouse) is now enabled.


Subject(s)
Biological Assay , Carcinogenicity Tests , Carcinogens/toxicity , Cell Transformation, Neoplastic/chemically induced , Neoplasms/chemically induced , Animals , Databases, Factual , Female , Humans , Male , Mice , Rats , Risk Assessment , Time Factors
12.
Fish Shellfish Immunol ; 88: 259-265, 2019 May.
Article in English | MEDLINE | ID: mdl-30716521

ABSTRACT

The pathogenesis of sepsis involves complex systems and multiple interrelationships between the host and pathogen producing high mortality rates in various animal species. In this study, hematological disturbances, innate immunity and survival during the septic process in Piaractus mesopotamicus inoculated with Aeromonas hydrophila were studied. For this aim, fish blood samples were taken from control and infected groups 1, 3, 6, and 9 h post-inoculation (HPI). Leukogram showed reduction in the number of leukocytes and thrombocytes, followed by cessation of leukocyte chemotaxis 6 HPI and severe morphological changes in leukocytes and erythrocytes. At 3 HPI production of reactive oxygen species increased and at 6 HPI decreased. There was no change in serum lysozyme concentration and lytic activity of the complement system, despite the progressive increase in serum lytic activity and bacterial agglutination. Finally, the changes in clinical signs due to aeromonosis and increasing septicemia resulted in a reduction in survival to 57.14% after 36 HPI. It was possible concluded that these hematological and immune are crucial event in the worsening of sepsis in P. mesopotamicus, and these findings are utility for diagnosing and understanding the pathophysiology sepsis in pacu induced by A. hydrophila.


Subject(s)
Aeromonas hydrophila/physiology , Characiformes/immunology , Fish Diseases/immunology , Gram-Negative Bacterial Infections/veterinary , Sepsis/veterinary , Animals , Characiformes/blood , Characiformes/microbiology , Erythrocytes/pathology , Fish Diseases/microbiology , Gram-Negative Bacterial Infections/immunology , Gram-Negative Bacterial Infections/mortality , Immunity, Innate , Leukocytes/pathology , Sepsis/immunology , Sepsis/microbiology , Sepsis/mortality
13.
J Neuroeng Rehabil ; 16(1): 117, 2019 10 15.
Article in English | MEDLINE | ID: mdl-31615535

ABSTRACT

BACKGROUND: Elevated energy cost is a hallmark feature of gait in older adults. As such, older adults display a general avoidance of walking which contributes to declining health status and risk of morbidity. Exoskeletons offer a great potential for lowering the energy cost of walking, however their complexity and cost often limit their use. To overcome some of these issues, in the present work we propose a passive wearable assistive device, namely Exoband, that applies a torque to the hip flexors thus reducing the net metabolic power of wearers. METHODS: Nine participants (age: 62.1 ± 5.6 yr; height: 1.71 ± 0.05 m; weight: 76.3 ± 11.9 kg) walked on a treadmill at a speed of 1.1 m/s with and without the Exoband. Metabolic power was measured by indirect calorimetry and spatio-temporal parameters measured using an optical measurement system. Heart rate and ratings of perceived exertion were recorded during data collection to monitor relative intensity of the walking trials. RESULTS: The Exoband was able to provide a consistent torque (~ 0.03-0.05 Nm/kg of peak torque) to the wearers. When walking with the Exoband, participants displayed a lower net metabolic power with respect to free walking (- 3.3 ± 3.0%; p = 0.02). There were no differences in spatio-temporal parameters or relative intensities when walking with or without the Exoband. CONCLUSIONS: This study demonstrated that it is possible to reduce metabolic power during walking in older adults with the assistance of a passive device that applies a torque to the hip joint. Wearable, lightweight and low-cost devices such as the Exoband have the potential to make walking less metabolically demanding for older individuals.


Subject(s)
Energy Metabolism/physiology , Hip Joint/physiology , Self-Help Devices , Walking/physiology , Aged , Biomechanical Phenomena/physiology , Exercise Test , Female , Humans , Male , Middle Aged
14.
J Biol Chem ; 292(36): 14867-14884, 2017 09 08.
Article in English | MEDLINE | ID: mdl-28710277

ABSTRACT

TMPRSS13 is a member of the type II transmembrane serine protease (TTSP) family. Although various TTSPs have been characterized in detail biochemically and functionally, the basic properties of TMPRSS13 remain unclear. Here, we investigate the activation, inhibition, post-translational modification, and localization of TMPRSS13. We show that TMPRSS13 is a glycosylated, active protease and that its own proteolytic activity mediates zymogen cleavage. Full-length, active TMPRSS13 exhibits impaired cell-surface expression in the absence of the cognate Kunitz-type serine protease inhibitors, hepatocyte growth factor activator inhibitor (HAI)-1 or HAI-2. Concomitant presence of TMPRSS13 with either HAI-1 or -2 mediates phosphorylation of residues in the intracellular domain of the protease, and it coincides with efficient transport of the protease to the cell surface and its subsequent shedding. Cell-surface labeling experiments indicate that the dominant form of TMPRSS13 on the cell surface is phosphorylated, whereas intracellular TMPRSS13 is predominantly non-phosphorylated. These data provide novel insight into the cellular properties of TMPRSS13 and highlight phosphorylation of TMPRSS13 as a novel post-translational modification of this TTSP family member and potentially other members of this family of proteases.


Subject(s)
Membrane Glycoproteins/metabolism , Membrane Proteins/chemistry , Membrane Proteins/metabolism , Proteinase Inhibitory Proteins, Secretory/metabolism , Serine Endopeptidases/chemistry , Serine Endopeptidases/metabolism , HEK293 Cells , Humans , Membrane Proteins/genetics , Phosphorylation , Serine Endopeptidases/genetics
15.
J Exp Biol ; 220(Pt 22): 4169-4176, 2017 11 15.
Article in English | MEDLINE | ID: mdl-29141879

ABSTRACT

Although it is clear that walking over different irregular terrain is associated with altered biomechanics, there is little understanding of how we quickly adapt to unexpected variations in terrain. This study aims to investigate which adaptive strategies humans adopt when performing an unanticipated step on an irregular surface, specifically a small bump. Nine healthy male participants walked at their preferred walking speed along a straight walkway during five conditions: four involving unanticipated bumps of two different heights, and one level walking condition. Muscle activation of eight lower limb muscles and three-dimensional gait analysis were evaluated during these testing conditions. Two distinct adaptive strategies were found, which involved no significant change in total lower limb mechanical work or walking speed. An ankle-based strategy was adopted when stepping on a bump with the forefoot, whereas a hip-based strategy was preferred when stepping with the rearfoot. These strategies were driven by a higher activation of the plantarflexor muscles (6-51%), which generated a higher ankle joint moment during the forefoot conditions and by a higher activation of the quadriceps muscles (36-93%), which produced a higher knee joint moment and hip joint power during the rearfoot conditions. These findings provide insights into how humans quickly react to unexpected events and could be used to inform the design of adaptive controllers for wearable robots intended for use in unstructured environments that can provide optimal assistance to the different lower limb joints.


Subject(s)
Lower Extremity/physiology , Walking/physiology , Adaptation, Physiological , Adult , Ankle Joint/physiology , Biomechanical Phenomena , Gait/physiology , Hip Joint/physiology , Humans , Knee Joint/physiology , Male , Young Adult
16.
Fish Shellfish Immunol ; 63: 53-67, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28159697

ABSTRACT

With the rapid development of nanotechnology there has been a corresponding increase in the application of titanium dioxide nanoparticles (TiO2-NPs) in various consumer and industrial products, consequently their potential health hazards and environmental effects are considered an aspect of great concern. In the present study, in order to assess the impact of TiO2-NPs in the marine environment, the biological effects of TiO2-NPs on a sea bass cell line (DLEC) were investigated. Cells were exposed for 24 h to different concentrations of TiO2-NPs (1, 8, 40, 200 and 1000 µg/ml) or co-exposed with CdCl2 (Cd). The effects of UV light irradiation were also investigated in cells treated with TiO2-NPs and/or Cd. The internalization of TiO2-NPs and the morphological cell modifications induced by the treatments were examined by transmission and scanning electron microscopy, this latter coupled with energy dispersive X-ray spectroscopy (EDS) for particle element detection. In addition, the effects of controlled exposures were studied evaluating the cytotoxicity, the DNA damage and the expression of inflammatory genes. Our study indicates that TiO2-NPs were localized on the cell surface mainly as agglomerates revealed by EDS analysis and that they were uptaken by the cells inducing morphological changes. Photoactivation of TiO2-NPs and/or co-exposure with Cd affects ATP levels and it contributes to induce acute cellular toxicity in DLEC cells dependent on Ti concentration. The inflammatory potential and the DNA damage, this latter displayed through a caspase-3 independent apoptotic process, were also demonstrated. Overall our data suggest that the interaction of TiO2-NPs with marine water contaminants, such as cadmium, and the UV irradiation, may be an additional threat to marine organisms.


Subject(s)
Bass/metabolism , Gene Expression Regulation/drug effects , Metal Nanoparticles/toxicity , Titanium/toxicity , Water Pollutants, Chemical/toxicity , Animals , Cadmium Chloride , Cell Line , Cell Survival/drug effects , DNA Damage/drug effects , Microscopy, Electron, Scanning/veterinary , Microscopy, Electron, Transmission/veterinary , Spectrometry, X-Ray Emission/veterinary , Titanium/metabolism , Ultraviolet Rays , Water Pollutants, Chemical/metabolism
17.
J Neuroeng Rehabil ; 14(1): 62, 2017 06 26.
Article in English | MEDLINE | ID: mdl-28651596

ABSTRACT

BACKGROUND: Only very recently, studies have shown that it is possible to reduce the metabolic rate of unloaded and loaded walking using robotic ankle exoskeletons. Some studies obtained this result by means of high positive work assistance while others combined negative and positive work assistance. There is no consensus about the isolated contribution of negative work assistance. Therefore, the aim of the present study is to examine the effect of varying negative work assistance at the ankle joint while maintaining a fixed level of positive work assistance with a multi-articular soft exosuit. METHODS: We tested eight participants during walking at 1.5 ms-1 with a 23-kg backpack. Participants wore a version of the exosuit that assisted plantarflexion via Bowden cables tethered to an off-board actuation platform. In four active conditions we provided different rates of exosuit bilateral ankle negative work assistance ranging from 0.015 to 0.037 W kg-1 and a fixed rate of positive work assistance of 0.19 W kg-1. RESULTS: All active conditions significantly reduced metabolic rate by 11 to 15% compared to a reference condition, where the participants wore the exosuit but no assistance was provided. We found no significant effect of negative work assistance. However, there was a trend (p = .08) toward greater reduction in metabolic rate with increasing negative work assistance, which could be explained by observed reductions in biological ankle and hip joint power and moment. CONCLUSIONS: The non-significant trend of increasing negative work assistance with increasing reductions in metabolic rate motivates the value in further studies on the relative effects of negative and positive work assistance. There may be benefit in varying negative work over a greater range or in isolation from positive work assistance.


Subject(s)
Ankle Joint , Exoskeleton Device , Walking , Adult , Algorithms , Biomechanical Phenomena , Energy Metabolism , Equipment Design , Healthy Volunteers , Hip Joint , Humans , Male , Movement , Oxygen Consumption , Robotics , Young Adult
18.
J Cell Physiol ; 231(7): 1476-83, 2016 Jul.
Article in English | MEDLINE | ID: mdl-26297835

ABSTRACT

Cancer progression is accompanied by increased levels of extracellular proteases that are capable of remodeling the extracellular matrix, as well as cleaving and activating growth factors and receptors that are involved in pro-cancerous signaling pathways. Several members of the type II transmembrane serine protease (TTSP) family have been shown to play critical roles in cancer progression, however, the expression or function of the TTSP Human Airway Trypsin-like protease (HAT) in carcinogenesis has not been examined. In the present study we aimed to determine the expression of HAT during squamous cell carcinogenesis. HAT transcript is present in several tissues containing stratified squamous epithelium and decreased expression is observed in carcinomas. We determined that HAT protein is consistently expressed on the cell surface in suprabasal/apical layers of squamous cells in healthy cervical and esophageal epithelia. To assess whether HAT protein is differentially expressed in normal tissue versus tissue in different stages of carcinogenesis, we performed a comprehensive immunohistochemical analysis of HAT protein expression levels and localization in arrays of paraffin embedded human cervical and esophageal carcinomas compared to the corresponding normal tissue. We found that HAT protein is expressed in the non-proliferating, differentiated cellular strata and is lost during the dedifferentiation of epithelial cells, a hallmark of squamous cell carcinogenesis. Thus, HAT expression may potentially be useful as a marker for clinical grading and assessment of patient prognosis in squamous cell carcinomas.


Subject(s)
Biomarkers, Tumor/genetics , Carcinogenesis/genetics , Carcinoma, Squamous Cell/genetics , Serine Endopeptidases/genetics , Biomarkers, Tumor/biosynthesis , Carcinoma, Squamous Cell/pathology , Cell Membrane/genetics , Cell Membrane/metabolism , Epithelium/metabolism , Epithelium/pathology , Esophagus/metabolism , Esophagus/pathology , Gene Expression Regulation, Neoplastic , Humans , Serine Endopeptidases/biosynthesis
19.
Biol Chem ; 397(9): 815-26, 2016 09 01.
Article in English | MEDLINE | ID: mdl-27078673

ABSTRACT

Carcinogenesis is accompanied by increased protein and activity levels of extracellular cell-surface proteases that are capable of modifying the tumor microenvironment by directly cleaving the extracellular matrix, as well as activating growth factors and proinflammatory mediators involved in proliferation and invasion of cancer cells, and recruitment of inflammatory cells. These complex processes ultimately potentiate neoplastic progression leading to local tumor cell invasion, entry into the vasculature, and metastasis to distal sites. Several members of the type II transmembrane serine protease (TTSP) family have been shown to play critical roles in cancer progression. In this review the knowledge collected over the past two decades about the molecular mechanisms underlying the pro-cancerous properties of selected TTSPs will be summarized. Furthermore, we will discuss how these insights may facilitate the translation into clinical settings in the future by specifically targeting TTSPs as part of novel cancer treatment regimens.


Subject(s)
Cell Membrane/enzymology , Molecular Targeted Therapy/methods , Neoplasms/drug therapy , Neoplasms/enzymology , Serine Proteases/metabolism , Animals , Diagnostic Imaging , Humans , Neoplasms/diagnostic imaging , Neoplasms/pathology
20.
Exerc Sport Sci Rev ; 44(1): 45-50, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26509482

ABSTRACT

We propose the hypothesis that soleus muscle function may provide a surrogate measure of functional capacity in patients with heart failure. We summarize literature pertaining to skeletal muscle as a locus of fatigue and present our recent findings, using in vivo imaging in combination with biomechanical experimentation and modeling, to reveal novel structure-function relationships in chronic heart failure skeletal muscle and gait.


Subject(s)
Heart Failure/physiopathology , Muscle, Skeletal/physiopathology , Biomechanical Phenomena , Exercise/physiology , Fatigue/physiopathology , Gait/physiology , Health Status Indicators , Humans , Muscle, Skeletal/anatomy & histology
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