scholarly journals 3-Amidinophenylalanine-derived matriptase inhibitors can modulate hepcidin production in vitro

2019 ◽  
Vol 393 (3) ◽  
pp. 511-520
Author(s):  
Erzsébet Pászti-Gere ◽  
Gergely Szombath ◽  
Michael Gütschow ◽  
Torsten Steinmetzer ◽  
András Székács
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Cell Cultures ◽  
Iron Homeostasis ◽  
Binding Mode ◽  
Type Ii ◽  
Transmembrane Serine Protease ◽  
Vitro Data ◽  
In Vitro Data

Abstract Matriptase-2 (MT-2) is a type II transmembrane serine protease and predominantly attached to the surface of hepatocytes. MT-2 decreases the production of hepcidin, a key regulator of iron homeostasis. In this study, the effects of four 3-amidinophenylalanine-derived combined matriptase-1/matriptase-2 (MT-1/2) inhibitors (MI-432, MI-441, MI-460, and MI-461) on hepcidin production were investigated in hepatocyte mono- and hepatocyte-Kupffer cell co-cultures. In MI-461-treated cell cultures, the extracellular hydrogen peroxide contents and the interleukin-6 and -8 (IL-6 and IL-8) levels were determined and compared to controls. Hepcidin overproduction was observed in hepatocytes upon treatment with MI-432, MI-441 and MI-461 at 50 μM. In contrast, extracellular hydrogen peroxide levels were not elevated significantly after matriptase inhibition with MI-461. Furthermore, MI-461 did not induce increases in IL-6 and IL-8 levels in these hepatic models. A model of the binding mode of inhibitor MI-461 in complex with MT-2 revealed numerous polar contacts contributing to the nanomolar potency of this compound. Based on the in vitro data on hepcidin regulation, treatment with MI-461 might be valuable in pathological states of iron metabolism without causing excessive oxidative stress.

scholarly journals Mitochondrial peroxiredoxin 3 is more resilient to hyperoxidation than cytoplasmic peroxiredoxins

2009 ◽  
Vol 421 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Andrew G. Cox ◽  
Andree G. Pearson ◽  
Juliet M. Pullar ◽  
Thomas J. Jönsson ◽  
W. Todd Lowther ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Structural Features ◽  
Sulfenic Acid ◽  
Cellular Environment ◽  
T Lymphoma Cells ◽  
T Lymphoma ◽  
Peroxiredoxin 3 ◽  
Vitro Data ◽  
In Vitro Data

The Prxs (peroxiredoxins) are a family of cysteine-dependent peroxidases that decompose hydrogen peroxide. Prxs become hyperoxidized when a sulfenic acid formed during the catalytic cycle reacts with hydrogen peroxide. In the present study, Western blot methodology was developed to quantify hyperoxidation of individual 2-Cys Prxs in cells. It revealed that Prx 1 and 2 were hyperoxidized at lower doses of hydrogen peroxide than would be predicted from in vitro data, suggesting intracellular factors that promote hyperoxidation. In contrast, mitochondrial Prx 3 was considerably more resistant to hyperoxidation. The concentration of Prx 3 was estimated at 125 μM in the mitochondrial matrix of Jurkat T-lymphoma cells. Although the local cellular environment could influence susceptibility, purified Prx 3 was also more resistant to hyperoxidation, suggesting that despite having C-terminal motifs similar to sensitive eukaryote Prxs, other structural features must contribute to the innate resilience of Prx 3 to hyperoxidation.

scholarly journals ROS networks: designs, aging, Parkinson’s disease and precision therapies

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Alexey N. Kolodkin ◽  
Raju Prasad Sharma ◽  
Anna Maria Colangelo ◽  
Andrew Ignatenko ◽  
Francesca Martorana ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Data Sets ◽  
Control Coefficient ◽  
Molecular Processes ◽  
Time Control ◽  
Vitro Data ◽  
In Vitro Data

Abstract How the network around ROS protects against oxidative stress and Parkinson’s disease (PD), and how processes at the minutes timescale cause disease and aging after decades, remains enigmatic. Challenging whether the ROS network is as complex as it seems, we built a fairly comprehensive version thereof which we disentangled into a hierarchy of only five simpler subnetworks each delivering one type of robustness. The comprehensive dynamic model described in vitro data sets from two independent laboratories. Notwithstanding its five-fold robustness, it exhibited a relatively sudden breakdown, after some 80 years of virtually steady performance: it predicted aging. PD-related conditions such as lack of DJ-1 protein or increased α-synuclein accelerated the collapse, while antioxidants or caffeine retarded it. Introducing a new concept (aging-time-control coefficient), we found that as many as 25 out of 57 molecular processes controlled aging. We identified new targets for “life-extending interventions”: mitochondrial synthesis, KEAP1 degradation, and p62 metabolism.

scholarly journals Biological Monitoring of Hexavalent Chromium and Serum Levels of the Senescence Biomarker Apolipoprotein J/Clusterin in Welders

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Evangelos C. Alexopoulos ◽  
Xenophon Cominos ◽  
Ioannis P. Trougakos ◽  
Magda Lourda ◽  
Efstathios S. Gonos ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hexavalent Chromium ◽  
Serum Levels ◽  
Toxic Substances ◽  
Age Related ◽  
Apolipoprotein J ◽  
Vitro Data ◽  
In Vitro Data

Welding fumes contain metals and other toxic substances known or strongly suspected to be related with oxidative stress and premature cellular senescence. Apolipoprotein J/Clusterin (ApoJ/CLU) is a glycoprotein that is differentially regulated in various physiological and disease states including ageing and age-related diseases. In vitro data showed that exposure of human diploid fibroblasts to hexavalent chromium (Cr(VI)) resulted in premature senescence and significant upregulation of the ApoJ/CLU protein. In this study we analyzed blood and urine samples from shipyard industry welders being exposed to different levels of Cr(VI) over a period of five months in order to assay in vivo the relation of ApoJ/CLU serum levels with Cr(VI). Our findings confirmed the previously reported in vitro data since reduction of Cr levels, after a worksite intervention, associated with lower levels of ApoJ/CLU serum levels. We concluded that the human ApoJ/CLU gene is responsive to the acute in vivo oxidative stress induced by heavy metals such as hexavalent chromium.

scholarly journals Phenotypic Analysis of Mice Lacking the Tmprss2-Encoded Protease

2006 ◽  
Vol 26 (3) ◽  
pp. 965-975 ◽  
Author(s):  
Tom S. Kim ◽  
Cynthia Heinlein ◽  
Robert C. Hackman ◽  
Peter S. Nelson
Keyword(s):  
Serine Protease ◽  
Serine Proteases ◽  
Biological Activities ◽  
Type Ii ◽  
Phenotypic Analysis ◽  
Normal Prostate ◽  
Prostate Hyperplasia ◽  
Transmembrane Serine Protease

ABSTRACT Tmprss2 encodes an androgen-regulated type II transmembrane serine protease (TTSP) expressed highly in normal prostate epithelium and has been implicated in prostate carcinogenesis. Although in vitro studies suggest protease-activated receptor 2 may be a substrate for TMPRSS2, the in vivo biological activities of TMPRSS2 remain unknown. We generated Tmprss2 −/− mice by disrupting the serine protease domain through homologous recombination. Compared to wild-type littermates, Tmprss2 −/− mice developed normally, survived to adulthood with no differences in protein levels of prostatic secretions, and exhibited no discernible abnormalities in organ histology or function. Loss of TMPRSS2 serine protease activity did not influence fertility, reduce survival, result in prostate hyperplasia or carcinoma, or alter prostatic luminal epithelial cell regrowth following castration and androgen replacement. Lack of an observable phenotype in Tmprss2 −/− mice was not due to transcriptional compensation by closely related Tmprss2 homologs. We conclude that the lack of a discernible phenotype in Tmprss2 −/− mice suggests functional redundancy involving one or more of the type II transmembrane serine protease family members or other serine proteases. Alternatively, TMPRSS2 may contribute a specialized but nonvital function that is apparent only in the context of stress, disease, or other systemic perturbation.

Use of Toxicokinetics in Risk Assessment Based on In Vitro Data

1993 ◽  
Vol 21 (2) ◽  
pp. 173-180
Author(s):  
Gunnar Johanson
Keyword(s):  
Risk Assessment ◽  
Whole Body ◽  
External Exposure ◽  
Target Dose ◽  
Toxic Response ◽  
Route Of Exposure ◽  
Vitro Data ◽  
In Vitro Data

This presentation addresses some aspects of the methodology, advantages and problems associated with toxicokinetic modelling based on in vitro data. By using toxicokinetic models, particularly physiologically-based ones, it is possible, in principle, to describe whole body toxicokinetics, target doses and toxic effects from in vitro data. Modelling can be divided into three major steps: 1) to relate external exposure (applied dose) of xenobiotic to target dose; 2) to establish the relationship between target dose and effect (in vitro data, e.g. metabolism in microsomes, partitioning in tissue homogenates, and toxicity in cell cultures, are useful in both steps); and 3) to relate external exposure to toxic effect by combining the first two steps. Extrapolations from in vitro to in vivo, between animal and man, and between high and low doses, can easily be carried out by toxicokinetic simulations. In addition, several factors that may affect the toxic response by changing the target dose, such as route of exposure and physical activity, can be studied. New insights concerning the processes involved in toxicity often emerge during the design, refinement and validation of the model. The modelling approach is illustrated by two examples: 1) the carcinogenicity of 1,3-butadiene; and 2) the haematotoxicity of 2-butoxyethanol. Toxicokinetic modelling is an important tool in toxicological risk assessment based on in vitro data. Many factors, some of which can, and should be, studied in vitro, are involved in the expression of toxicity. Successful modelling depends on the identification and quantification of these factors.

scholarly journals Lymphocutaneous spread of Mycobacterium elephantis in an immunocompetent individual: A case report

2021 ◽  
Vol 9 ◽  
pp. 2050313X2110349
Author(s):  
Brett D Edwards ◽  
Ranjani Somayaji ◽  
Dina Fisher ◽  
Justin C Chia
Keyword(s):  
Case Report ◽  
Chronic Lung Disease ◽  
Contaminated Soil ◽  
Lung Abscess ◽  
Immunocompetent Individual ◽  
First Case ◽  
Antimycobacterial Agents ◽  
Vitro Data ◽  
In Vitro Data

Mycobacterium elephantis was first described when isolated from an elephant that succumbed to lung abscess. However, despite this namesake, it is not associated with animals and has been described most often as a probable colonizer rather than pathogen in humans with chronic lung disease. In this report, we describe the first case of lymphocutaneous infection from M. elephantis, likely as a result of cutaneous inoculation with contaminated soil. This offers further evidence to its capabilities as a pathogen. We provide a review of the limited prior reports of M. elephantis and outline the available in vitro data on efficacy of various antimycobacterial agents.

Prediction of CYP2D6 Drug Interactions from In Vitro Data: Evidence for Substrate-Dependent Inhibition

2011 ◽  
Vol 40 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Brooke M. VandenBrink ◽  
Robert S. Foti ◽  
Dan A. Rock ◽  
Larry C. Wienkers ◽  
Jan L. Wahlstrom
Keyword(s):  
Drug Interactions ◽  
Dependent Inhibition ◽  
Vitro Data ◽  
In Vitro Data

Pharmacokinetics and Pharmacodynamics of Antistaphylococcal Antibiotics in Continuous Ambulatory Peritoneal Dialysis Patients

1993 ◽  
Vol 13 (2_suppl) ◽  
pp. 367-371 ◽  
Author(s):  
Erich Keller
Keyword(s):  
Peritoneal Dialysis ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Inhibitory Concentration ◽  
Pharmacokinetic Data ◽  
Pharmacokinetics And Pharmacodynamics ◽  
Antistaphylococcal Activity ◽  
Cure Rates ◽  
Vitro Data ◽  
In Vitro Data

Staphylococci are the leading pathogens In continuous ambulatory peritoneal dialysis (CAPD)-related peritonitis. Vancomycin appears to be an outstanding antistaphylococcal drug because resistance to It Is nearly absent. The pharmacokinetics of vancomycin and clinical cure rates of peritonitis with different dosing guidelines have been studied extensively. Different dosing guidelines with IP or IV loading doses followed or not followed by IP maintenance doses are used successfully, despite the fact that some of the dosing schemes produce apparently suboptimal drug levels referring to In vitro data like the MIC value (minimum Inhibitory concentration). Alternatively, amlnoglycosldes, cephalosporlns, Isoxazolyl penicillins, and broad-spectrum penicillins combined with betalactamase Inhibitors may be used for the treatment of gram-positive peritonitis. For the above panicillins pharmacokinetic data are scarce, and clinical experience is limited. Rifampin has excellent Intracellular antistaphylococcal activity and should be used In combination with other antibiotics. Although pharmacokinetic data are lacking, rifampin dosages do not require adaptation to renal function or replacement therapy.

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