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European Journal of Mass Spectrometry... Oct 2021Butyl-terminated poly(2-vinylpyridine) (P2VP), CH(CHN)H, is evaluated for use as an external and internal mass calibrant in positive-ion matrix-assisted laser...
Poly(2-vinylpyridine) as a reference compound for mass calibration in positive-ion matrix-assisted laser desorption/ionization-mass spectrometry on different instrumental platforms.
Butyl-terminated poly(2-vinylpyridine) (P2VP), CH(CHN)H, is evaluated for use as an external and internal mass calibrant in positive-ion matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). P2VP oligomers covering the 450-4500 range are employed to calibrate a time-of-flight (TOF) mass spectrometer in linear and reflector mode, an ion mobility-quadrupole-time-of-flight (IM-Q-TOF) mass spectrometer, and a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. The proton affinity of P2VPs introduced by the numerous pyridyl groups leads to the almost exclusive formation of [M + H] ions with common acidic matrices like α-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB) as well as with the non-acidic and aprotic matrices 1,8-dihydroxy-10-anthracen-9-on (dithranol) and 2-[(2)-3-(4--butylphenyl)-2-methylprop-2-enylidene]malonitrile (DCTB). This prevalence of [M + H] ions evenly spaced at Δ() = 105.0578 renders butyl-terminated P2VP oligomers as convenient mass calibrants. The mass accuracies achieved across various ranges with different mass analyzers and modes of operation are evaluated by using established standard compounds. Results as obtained by internal or external calibration are presented. Further, the compilation of mass reference lists tailored to suit the respective analyzer modes is discussed and those reference files are provided.
PubMed: 34738841
DOI: 10.1177/14690667211055701 -
Research Square Feb 2024Little is known about IL-17 expression in psoriasis and the actual cellular source of IL-17 remains incompletely defined. We show that high numbers of IL-17 + mast cells...
Little is known about IL-17 expression in psoriasis and the actual cellular source of IL-17 remains incompletely defined. We show that high numbers of IL-17 + mast cells persisted in resolved lesions after treatment (anti-IL-17A, anti-IL-23, UVB or topical dithranol) and correlated inversely with the time span in remission. IL-17 + mast cells were found in T cell-rich areas and often close to resident memory T cells (T) in active psoriasis and resolved lesional skin. Digital cytometry by deconvolution of RNA-seq data showed that activated mast cells were increased in psoriatic skin, while resting mast cells were almost absent and both returned to normal levels after treatment. When primary human skin mast cells were stimulated with T cell cytokines (TNFα, IL-22 and IFNγ), they responded by releasing more IL-17A, as measured by ELISA. mRNA detection using padlock probes specific for transcript variants of , and (encoding the Th17 transcription factor RORγt) revealed positive mRNA signals for , and RORCin tryptase + cells, demonstrating that mast cells have the transcriptional machinery to actively produce IL-17. Mast cells thus belong to the center of the IL-23/IL-17 axis and high numbers of IL-17 + mast cells predict an earlier disease recurrence.
PubMed: 38410434
DOI: 10.21203/rs.3.rs-3958361/v1 -
BMC Research Notes Jan 2018Biologically active cell penetrating peptides (CPPs) are an emerging class of therapeutic agent. The wasp venom peptide mastoparan is an established CPP that modulates...
OBJECTIVE
Biologically active cell penetrating peptides (CPPs) are an emerging class of therapeutic agent. The wasp venom peptide mastoparan is an established CPP that modulates mitochondrial activity and triggers caspase-dependent apoptosis in cancer cells, as does the mastoparan analogue mitoparan (mitP). Mitochondrial depolarisation and activation of the caspase cascade also underpins the action of dithranol, a topical agent for treatment of psoriasis. The effects of a potent mitP analogue on mitochondrial activity were therefore examined to assess its potential as a novel approach for targeting mitochondria for the treatment of psoriasis.
RESULTS
In HaCaT keratinocytes treated with the mitP analogue Z-Gly-RGD(DPhe)-mitP for 24 h, a dose-dependent loss of mitochondrial activity was observed using the methyl-thiazolyl-tetrazolium (MTT) assay. At 10 μmol L, MTT activity was less than 30% that observed in untreated cells. Staining with the cationic dye JC-1 suggested that Z-Gly-RGD(DPhe)-mitP also dissipated the mitochondrial membrane potential, with a threefold increase in mitochondrial depolarisation levels. However, caspase activity appeared to be reduced by 24 h exposure to Z-Gly-RGD(DPhe)-mitP treatment. Furthermore, Z-Gly-RGD(DPhe)-mitP treatment had little effect on overall cell viability. Our findings suggest Z-Gly-RGD(DPhe)-mitP promotes the loss of mitochondrial activity but does not appear to evoke apoptosis in HaCaT keratinocytes.
Topics: Animals; Cell Line; Cell Survival; Cell-Penetrating Peptides; Dose-Response Relationship, Drug; Humans; Intercellular Signaling Peptides and Proteins; Keratinocytes; Membrane Potential, Mitochondrial; Mitochondria; Peptides; Wasp Venoms
PubMed: 29378648
DOI: 10.1186/s13104-018-3192-1 -
Proceedings of the National Academy of... Aug 2017Chronic cocaine use is associated with prominent morphological changes in nucleus accumbens shell (NACsh) neurons, including increases in dendritic spine density along...
Chronic cocaine use is associated with prominent morphological changes in nucleus accumbens shell (NACsh) neurons, including increases in dendritic spine density along with enhanced motivation for cocaine, but a functional relationship between these morphological and behavioral phenomena has not been shown. Here we show that brain-derived neurotrophic factor (BDNF) signaling through tyrosine kinase B (TrkB) receptors in NACsh neurons is necessary for cocaine-induced dendritic spine formation by using either localized TrkB knockout or viral-mediated expression of a dominant negative, kinase-dead TrkB mutant. Interestingly, augmenting wild-type TrkB expression after chronic cocaine self-administration reverses the sustained increase in dendritic spine density, an effect mediated by TrkB signaling pathways that converge on extracellular regulated kinase. Loss of TrkB function after cocaine self-administration, however, leaves spine density intact but markedly enhances the motivation for cocaine, an effect mediated by specific loss of TrkB signaling through phospholipase Cgamma1 (PLCγ1). Conversely, overexpression of PLCγ1 both reduces the motivation for cocaine and reverses dendritic spine density, suggesting a potential target for the treatment of addiction in chronic users. Together, these findings indicate that BDNF-TrkB signaling both mediates and reverses cocaine-induced increases in dendritic spine density in NACsh neurons, and these morphological changes are entirely dissociable from changes in addictive behavior.
Topics: Animals; Anthralin; Brain-Derived Neurotrophic Factor; Cocaine; Cocaine-Related Disorders; Dendritic Spines; HEK293 Cells; Humans; Male; Neurons; Nucleus Accumbens; Rats; Rats, Sprague-Dawley; Receptor, trkB; Signal Transduction
PubMed: 28808012
DOI: 10.1073/pnas.1702441114 -
Polymers May 2017Herein, we demonstrate a facile methodology to synthesis a novel methacrylic phosphonic acid (PA)-functionalized polyhedral oligomeric silsesquioxanes (POSSs) via...
Herein, we demonstrate a facile methodology to synthesis a novel methacrylic phosphonic acid (PA)-functionalized polyhedral oligomeric silsesquioxanes (POSSs) via thiol-ene click reaction using octamercapto thiol-POSS and ethylene glycol methacrylate phosphate (EGMP) monomer. The presence of phosphonic acid moieties and POSS-cage structure in POSS-S-PA was confirmed by Fourier transform infrared (FT-IR) and nuclear magnetic resonance (¹H, Si and P-NMR) analyses. Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrum of POSS-S-PA acquired in a dithranol matrix, which has specifically designed for intractable polymeric materials. The observed characterization results signposted that novel organo-inorganic hybrid POSS-S-PA would be an efficacious material for fuel cells as a proton exchange membrane and high-temperature applications due to its thermal stability of 380 °C.
PubMed: 30970870
DOI: 10.3390/polym9060192 -
Drug Design, Development and Therapy 2015Expression of ErbB2 protein is inversely correlated with the prognosis in cancer patients. Consequently, strategies targeting ErbB2 remain an attractive option in...
Expression of ErbB2 protein is inversely correlated with the prognosis in cancer patients. Consequently, strategies targeting ErbB2 remain an attractive option in treating several types of malignancies, including oral cancer. In addition, many studies have shown that emodin and emodin derivatives are able to inhibit growth of ErbB2-overexpressing tumor cells. In this study, a series of computer modeling-generated emodin analogues were synthesized and tested for their antiproliferative activity against oral cancer cell lines overexpressing ErbB2. Among these analogues, em08red (1,8-dihydroxy-9(10H)-anthracenone) demonstrated potent antiproliferative activity against all three tested ErbB2-overexpressing cell lines, ie, FaDu, HSC3, and OECM1. Treatment with em08red significantly downregulated activation of ErbB2 as well as the ErbB2 protein expression level in the tested cell lines and induced G2 arrest. Antiapoptosis protein (Bcl-xl and Bcl-2) expression levels were also downregulated, and active caspase-3 and caspase-9 was detected in cells after treatment with em08red. Moreover, treatment with em08red stimulated production of cytotoxic reactive oxygen species in treated cells, and this could be partially reversed by pretreatment with N-acetylcysteine. Overall, we demonstrated inhibition of ErbB2 function and induction of reactive oxygen species in tumor cells by em08red, which prevented proliferation of tumor cells and induced apoptotic cell death.
Topics: Anthralin; Antineoplastic Agents; Cell Cycle; Cell Proliferation; Dose-Response Relationship, Drug; Down-Regulation; Drug Screening Assays, Antitumor; Humans; Intracellular Space; Molecular Structure; Oxidative Stress; Reactive Oxygen Species; Receptor, ErbB-2; Structure-Activity Relationship; Tumor Cells, Cultured
PubMed: 25792810
DOI: 10.2147/DDDT.S66647 -
Indian Journal of Microbiology Dec 2017Present study demonstrated the expression of cloned RSE163 keratinase gene and in silico binding affinities of deduced protein with psoriasis topical drugs for systemic...
Present study demonstrated the expression of cloned RSE163 keratinase gene and in silico binding affinities of deduced protein with psoriasis topical drugs for systemic absorption and permeation through skin. The gene expressed in showed significantly higher keratinase activity 450 ± 10.43 U representing 1342 bp nucleotides encoding 447 amino acids with molecular weight of 46 kDa. The modeled structure was validated using ramachandran's plot showing 305 residues (84.3%) in most favoured region. Docking studies using extra precision (XP) method of Glide showed optimum binding affinities with the drugs Acitretin (- 39.62 kcal/mol), Clobetasol propionate (- 37.90 kcal/mol), Fluticasone (- 38.53 kcal/mol), Desonide (- 32.23 kcal/mol), Anthralin (- 38.04 kcal/mol), Calcipotreine (- 21.55 kcal/mol) and Mometasone (- 28.40 kcal/mol) in comparison to other psoriasis drugs. The results can further be correlated with in vitro enzymatic experiments using keratinase as an effective drug mediator through skin to serve the unmet need of industries.
PubMed: 29151650
DOI: 10.1007/s12088-017-0677-x -
The Analyst Mar 2015In order to understand biological systems it is important to gain pertinent information on the spatial localisation of chemicals within cells. With the relatively recent...
In order to understand biological systems it is important to gain pertinent information on the spatial localisation of chemicals within cells. With the relatively recent advent of high-resolution chemical imaging this is being realised and one rapidly developing area of research is the Raman mapping of single cells, an approach whose success has vast potential for numerous areas of biomedical research. However, there is a danger of undermining the potential routine use of Raman mapping due to a lack of consistency and transparency in the way false-shaded Raman images are constructed. In this study we demonstrate, through the use of simulated data and real Raman maps of single human keratinocyte (HaCaT) cells, how changes in the application of colour shading can dramatically alter the final Raman images. In order to avoid ambiguity and potential subjectivity in image interpretation we suggest that data distribution plots are used to aid shading approaches and that extreme care is taken to use the most appropriate false-shading for the biomedical question under investigation.
Topics: Anthralin; Cell Line; Dermatologic Agents; Humans; Image Processing, Computer-Assisted; Keratinocytes; Single-Cell Analysis; Spectrum Analysis, Raman
PubMed: 25666258
DOI: 10.1039/c4an02298j -
JAAD Case Reports Mar 2019
PubMed: 30891474
DOI: 10.1016/j.jdcr.2019.01.006 -
Journal of Investigational Allergology... Oct 2018
Topics: Child, Preschool; Dermatitis, Allergic Contact; Dermatitis, Atopic; Dermatitis, Irritant; Female; Humans; Inflammation; Skin
PubMed: 30350787
DOI: 10.18176/jiaci.0276