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Journal of Plant Physiology Dec 2023Drought stress is a major factor limiting agricultural development, and exogenous polyamines (PAs) can increase plant drought resistance by enhancing antioxidant...
Enriched endogenous free Spd and Spm in alfalfa (Medicago sativa L.) under drought stress enhance drought tolerance by inhibiting HO production to increase antioxidant enzyme activity.
Drought stress is a major factor limiting agricultural development, and exogenous polyamines (PAs) can increase plant drought resistance by enhancing antioxidant activity, but few studies have examined whether endogenous PAs enhance the plant antioxidant system. Here, to investigate the effects of endogenous PAs on the antioxidant system of alfalfa under drought stress and the underlying mechanisms, two alfalfa cultivars, Longzhong (drought resistant) and Gannong No. 3 (drought sensitive), were used as test materials, and their seedlings were treated with polyethylene glycol (PEG-6000) for 8 days at -1.2 MPa to simulate drought stress. The levels of free PAs [putrescine (Put), spermidine (Spd) and spermine (Spm)], hydrogen peroxide (HO), malondialdehyde (MDA), key PA metabolism enzyme [arginine decarboxylase (ADC), ornithine decarboxylase (ODC), S-adenosylmethionine decarboxylase (SAMDC), polyamine oxidase (PAO), and diamine oxidase (DAO)] activities, and antioxidant enzyme [superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD)] activities were measured. These physiological indicators were used for correlation analysis to investigate the relationship between PA metabolism and the antioxidant enzyme system. The results showed that PA synthesis in alfalfa under drought stress was dominated by the ADC pathway. Spd and Spm played an important role in improving drought tolerance. The high levels of ADC and SAMDC activities were facilitated by the conversion of Put to Spd and Spm. HO generation by oxidative decomposition of PAs was mainly dependent on the oxidative decomposition of DAO but not PAO. Low DAO activity favored low HO production. Spd, Spm, ADC, ODC and SAMDC were positively correlated with the antioxidant enzymes SOD, CAT and POD in both cultivars under drought. Therefore, we concluded that high ADC and SAMDC activities in alfalfa promoted the conversion of Put to Spd and Spm, leading to high accumulation of Spd and Spm and low Put accumulation. Low Put levels led to low HO production through low DAO activity, and low HO levels induced the expression of antioxidant enzyme-encoding genes to improve antioxidant enzyme activity and reduce MDA accumulation and thereby enhanced drought resistance in alfalfa.
Topics: Spermidine; Spermine; Antioxidants; Hydrogen Peroxide; Medicago sativa; Droughts; Drought Resistance; Polyamines; Putrescine; Superoxide Dismutase; Peroxidases
PubMed: 37988872
DOI: 10.1016/j.jplph.2023.154139 -
American Journal of Physiology.... Nov 2023In numerous subtypes of central and peripheral neurons, small and intermediate conductance Ca-activated K (SK and IK, respectively) channels are important regulators of...
In numerous subtypes of central and peripheral neurons, small and intermediate conductance Ca-activated K (SK and IK, respectively) channels are important regulators of neuronal excitability. Transcripts encoding SK channel subunits, as well as the closely related IK subunit, are coexpressed in the soma of colonic afferent neurons with receptors for the algogenic mediators ATP and bradykinin, P2X3 and B, highlighting the potential utility of these channels as drug targets for the treatment of abdominal pain in gastrointestinal diseases such as irritable bowel syndrome. Despite this, pretreatment with the dual SK/IK channel opener SKA-31 had no effect on the colonic afferent response to ATP, bradykinin, or noxious ramp distention of the colon. Inhibition of SK or IK channels with apamin or TRAM-34, respectively, yielded no change in spontaneous baseline afferent activity, indicating these channels are not tonically active. In contrast to its lack of effect in electrophysiological experiments, comparable concentrations of SKA-31 abolished ongoing peristaltic activity in the colon ex vivo. Treatment with the K7 channel opener retigabine blunted the colonic afferent response to all applied stimuli. Our data therefore highlight the potential utility of K7, but not SK/IK, channel openers as analgesic agents for the treatment of abdominal pain. Despite marked coexpression of small (, ) and intermediate () conductance calcium-activated potassium channel transcripts with P2X3 () or bradykinin B () receptors in colonic sensory neurons, pharmacological activation of these channels had no effect on the colonic afferent response to ATP, bradykinin or luminal distension of the colon. This is in contrast to the robust inhibitory effect of the K7 channel opener, retigabine.
Topics: Humans; Bradykinin; Carbamates; Abdominal Pain; Adenosine Triphosphate; Small-Conductance Calcium-Activated Potassium Channels; Phenylenediamines
PubMed: 37667839
DOI: 10.1152/ajpgi.00141.2023 -
Journal of Environmental Sciences... Oct 2023In the present work, functional diamine groups into indium frameworks to synthesize cyclic carbonates from CO and epoxides with efficient catalytic activity in the...
In the present work, functional diamine groups into indium frameworks to synthesize cyclic carbonates from CO and epoxides with efficient catalytic activity in the absence of co-catalyst and solvent are reported for the first time. Crystalline porous materials (CPM)-5 modified with 1,2-phenylene diamine and ethylene diamine (CPM-5-PhDA and CPM-5-EDA), were prepared using a post-synthetic modification (PSM) method. The properties of the modified CPM-5 were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), N-adsorption, scanning electron microscopy (SEM), CO adsorption, and temperature programmed desorption TPD methods. The presence of diamine groups as basic sites and indium Lewis acid sites in the framework structure were desirable for high catalytic activity. For a given catalyst weight, CPM-5-PhDA was the best candidate to appear with great catalytic activity and selectivity for the cycloaddition reaction at 100°C and 1 MPa CO under co-catalyst and solvent free conditions. CPM-5-PhDA also was found to afford large and bulky epoxides. The catalyst can be easily separated and reused five times without any decline in activity.
Topics: Indium; Solvents; Carbon Dioxide; Diamines; Porosity; Spectroscopy, Fourier Transform Infrared; Epoxy Compounds
PubMed: 37336602
DOI: 10.1016/j.jes.2022.08.029 -
European Journal of Pharmacology May 2024Hyperuricemic nephropathy (HN) is characterized by renal fibrosis and tubular necrosis caused by elevated uric acid levels. Ferroptosis, an iron-dependent type of cell...
Hyperuricemic nephropathy (HN) is characterized by renal fibrosis and tubular necrosis caused by elevated uric acid levels. Ferroptosis, an iron-dependent type of cell death, has been implicated in the pathogenesis of kidney diseases. The objective of this study was to explore the role of ferroptosis in HN and the impact of a ferroptosis inhibitor, ferrostatin-1 (Fer-1). The study combined adenine and potassium oxonate administration to establish a HN model in mice and treated HK-2 cells with uric acid to simulate HN conditions. The effects of Fer-1 on the renal function, fibrosis, and ferroptosis-associated molecules were investigated in HN mice and HK-2 cells treated with uric acid. The HN mice presented with renal dysfunction characterized by elevated tissue iron levels and diminished antioxidant capacity. There was a significant decrease in the mRNA and protein expression levels of SLC7A11, GPX4, FTL-1 and FTH-1 in HN mice. Conversely, treatment with Fer-1 reduced serum uric acid, serum creatinine, and blood urea nitrogen, while increasing uric acid levels in urine. Fer-1 administration also ameliorated renal tubule dilatation and reduced renal collagen deposition. Additionally, Fer-1 also upregulated the expression levels of SLC7A11, GPX4, FTL-1, and FTH-1, decreased malondialdehyde and iron levels, and enhanced glutathione in vivo and in vitro. Furthermore, we first found that Fer-1 exhibited a dose-dependent inhibition of URAT1, with the IC value of 7.37 ± 0.66 μM. Collectively, the current study demonstrated that Fer-1 effectively mitigated HN by suppressing ferroptosis, highlighting the potential of targeting ferroptosis as a therapeutic strategy for HN.
Topics: Mice; Animals; Uric Acid; Ferroptosis; Hyperuricemia; Kidney Diseases; Fibrosis; Iron; Cyclohexylamines; Phenylenediamines
PubMed: 38556118
DOI: 10.1016/j.ejphar.2024.176528 -
Bioresource Technology Aug 2023Lignocellulosic biomass is a promising feedstock to produce sustainable fuels and energy toward a green bioeconomy. A surfactant-assisted ethylenediamine (EDA) was...
Lignocellulosic biomass is a promising feedstock to produce sustainable fuels and energy toward a green bioeconomy. A surfactant-assisted ethylenediamine (EDA) was developed for the deconstruction and conversion of corn stover in this study. The effects of surfactants on the whole conversion process of corn stover was also evaluated. The results showed that xylan recovery and lignin removal in solid fraction were significantly enhanced by surfactant-assisted EDA. The glucan and xylan recoveries in solid fraction reached 92.1% and 65.7%, respectively, while the lignin removal was 74.5% by sodium dodecyl sulfate (SDS)-assisted EDA. SDS-assisted EDA also improved the sugar conversion in 12 h enzymatic hydrolysis at low enzyme loadings. The ethanol production and glucose consumption of washed EDA pretreated corn stover in simultaneous saccharification and co-fermentation were improved with the addition of 0.001 g/mL SDS. Therefore, surfactant-assisted EDA showed the potential to improve the bioconversion performance of biomass.
Topics: Lignin; Zea mays; Surface-Active Agents; Biomass; Xylans; Fermentation; Ethylenediamines; Hydrolysis
PubMed: 37187332
DOI: 10.1016/j.biortech.2023.129174 -
Analytical Chemistry Jul 2023Oxidase-mimicking nanozymes with specificity for catalyzing oxidation of aromatic amines are of great significance for recognition of aromatic amines but rarely...
Oxidase-mimicking nanozymes with specificity for catalyzing oxidation of aromatic amines are of great significance for recognition of aromatic amines but rarely reported. Herein, Cu-A nanozyme (synthesized with Cu as a node and adenine as a linker) could specifically catalyze oxidation of -phenylenediamine (OPD) in Britton-Robinson buffer solution. Such a specific catalytic performance was also corroborated with other aromatic amines, such as -phenylenediamine (PPD), 1,5-naphthalene diamine (1,5-NDA), 1,8-naphthalene diamine (1,8-NDA), and 2-aminoanthracene (2-AA). Moreover, the presence of salts (1 mM NaNO, NaHCO, NHCl, KCl, NaCl, NaBr, and NaI) greatly mediated the catalytic activity with the order of NaNO < blank ≈ NaHCO < NHCl ≈ KCl ≈ NaCl < NaBr < NaI, which was due to anions sequentially increasing interfacial Cu content via anionic redox reaction, while the effect of cations was negligible. With the increased Cu content, decreased and increased, indicating valence-engineered catalytic activity. Based on high specificity and satisfactory activity, a colorimetric sensor array with NaCl, NaBr, and NaI as sensing channels was constructed to identify five representative aromatic amines (OPD, PPD, 1,5-NDA, 1,8-NDA, and 2-AA) as low as 50 μM, quantitatively analyze single aromatic amine (with OPD and PPD as model analysts), and even identify 20 unknown samples with an accuracy of 100%. In addition, the performance was further validated through accurately recognizing various concentration ratios of binary, ternary, quaternary, and quinary mixtures. Finally, the practical applications were demonstrated by successfully discriminating five aromatic amines in tap, river, sewage, and sea water, providing a simple and feasible assay for large-scale scanning aromatic amine levels in environmental water samples.
Topics: Oxidoreductases; Amines; Sodium Chloride; Oxidation-Reduction; Phenylenediamines; Naphthalenes; Colorimetry
PubMed: 37402320
DOI: 10.1021/acs.analchem.3c01488 -
The Journal of Organic Chemistry Sep 2023Purine DNA represents an alternative pairing system formed by two purines in the base pair with the recognition elements of Watson-Crick DNA. Base functionalization of...
Purine DNA Constructs Designed to Expand the Genetic Code: Functionalization, Impact of Ionic Forms, and Molecular Recognition of 7-Deazaxanthine-7-Deazapurine-2,6-diamine Base Pairs and Their Purine Counterparts.
Purine DNA represents an alternative pairing system formed by two purines in the base pair with the recognition elements of Watson-Crick DNA. Base functionalization of 7-deaza-2'-deoxyxanthosine with ethynyl and octadiynyl residues led to clickable side chain derivatives with short and long linker arms. As complementary bases, purine-2,6-diamine or 7-deazapurine-2,6-diamine 2'-deoxyribonucleosides were used. 7-Deaza-7-iodo-2'-deoxyxanthosine served as a starting material for Sonogashira cross-coupling and the -nitrophenylethyl group for base protection. Phosphoramidite building blocks for DNA synthesis were prepared. Oligonucleotides containing single modifications or runs of three purine base pairs embedded in 12-mer Watson-Crick DNA were synthesized and hybridized with complementary strands with purine- or 7-deazapurine-2,6-diamine located opposite to the xanthine derivatives. The stability of base pairs was evaluated in a comparative study on the basis of DNA melting experiments and values. As 7-deazaxanthine and xanthine nucleosides form anionic forms at neutral pH, duplex stability became p-dependent, and the system with 7-deazapurine displayed a significant higher stability as that containing xanthine. Alkynyl side chains are well accommodated in the purine-purine helix. Click adducts with pyrene showed that short linker arms destabilize duplexes, whereas long linkers increase duplex stability. CD and fluorescence measurements provide further insights into purine-purine base pairing.
Topics: Base Pairing; Genetic Code; Purines; Xanthine; Diamines; Ions
PubMed: 37669119
DOI: 10.1021/acs.joc.3c01370 -
Clinical Chemistry and Laboratory... Nov 2023C-peptide and insulin are peptide hormones and their stability is affected by a number of pre-analytical factors. The study aimed to investigate the impact of sample...
OBJECTIVES
C-peptide and insulin are peptide hormones and their stability is affected by a number of pre-analytical factors. The study aimed to investigate the impact of sample type, storage temperature and time delays before centrifugation and analysis on the stability of C-peptide and insulin.
METHODS
Ten healthy non-diabetic adults in fasting and non-fasting state were enrolled. 40 mL of blood was collected from each participant into SST and dipotassium EDTA tubes. Samples were centrifuged immediately or at timed intervals (8, 12, 48 and 72 h). After baseline measurements on the Roche Cobas e602 analyzer using electrochemiluminescence immunoassays, aliquots were stored at room temperature (RT), 2-8 and -20 °C for 4 h to 30 days. The percentage deviation (PD) from baseline was calculated and a change greater than desirable biological variation total error was considered clinically significant.
RESULTS
C-peptide was more stable in separated serum than plasma (PD of -5 vs. -13 %) samples stored at 2-8 °C for 7 days and was most unstable at RT when centrifugation was delayed (PD -46 % in plasma and -74 % in serum after 48 h). Insulin was more stable in plasma than in serum under the different storage conditions with a minimum PD of -1% when stored at -20 °C for 30 days. When samples were kept unspun at RT for 72 h, PD was -23 and -80 % in plasma and serum, respectively.
CONCLUSIONS
C-peptide was more stable in serum provided the sample was centrifuged immediately and stored in the fridge or freezer while insulin was found to be more stable in EDTA plasma.
Topics: Adult; Humans; Insulin; C-Peptide; Edetic Acid; Plasma; Serum; Blood Specimen Collection; Temperature
PubMed: 37409980
DOI: 10.1515/cclm-2023-0339 -
Journal of Neuroscience Research Nov 2023Blood-derived extracellular vesicles (EVs) are a popular source of biomarkers for central nervous system (CNS) diseases, but inconsistencies in isolation and analysis... (Review)
Review
Blood-derived extracellular vesicles (EVs) are a popular source of biomarkers for central nervous system (CNS) diseases, but inconsistencies in isolation and analysis hinder their clinical translation. This review summarizes recent studies that investigate the impact of different anticoagulated plasma and serum on the yield, purity, and molecular content of EVs. Specifically, the studies compare ethylenediaminetetraacetic acid (EDTA), citrate, heparin plasma, and serum and highlight the risk of contamination from platelet-derived EVs. Here, I offer practical guidelines for standardizing EV isolation and analysis, recommending the use of plasma anticoagulated with acid-citrate-dextrose (ACD) or citrate followed by EDTA and heparin, subgroup analyses for samples from different biobank repositories, and avoiding serum and plasma-to-serum transformation. Other factors like illness, age, gender, meal timing, exercise, circadian timing, and arm pressure during blood draw can alter EV signatures. Yet, how these variables interact with different anticoagulated plasma or serum samples is unclear, necessitating further research. Furthermore, whether the changes are dependent on the isolation or quantification methodology remains an area of investigation. Importantly, the perspective emphasizes the need for consistency in experimental methodologies to improve the reproducibility and clinical applicability of CNS-originating EV biomarker studies. The proposed guidelines, along with ongoing efforts to standardize blood sample handling and collection, may facilitate the development of more reliable and informative CNS-originating EV biomarkers for diagnosis, prognosis, and treatment monitoring of CNS diseases.
Topics: Edetic Acid; Reproducibility of Results; Extracellular Vesicles; Heparin; Biomarkers
PubMed: 37501394
DOI: 10.1002/jnr.25231 -
Skinmed 2023A-24-year-old woman reported with asymptomatic facial lesions present for 6 months. Examination revealed two closely located nodules which were firm, nontender, slightly...
A-24-year-old woman reported with asymptomatic facial lesions present for 6 months. Examination revealed two closely located nodules which were firm, nontender, slightly erythematosus with crusting over the left cheek (Figure 1A). There was no regional lymphadenopathy, and the systemic examination was within normal limits. The differential diagnosis included cutaneous leishmaniasis, keratoacanthoma, and basal cell carcinoma. Tissue smear from nodules failed to reveal bodies. The histopathologic examination revealed nonca-seating epithelioid granulomas with lymphocyte cuffing in the dermis (Figures 2A and 2B). Special staining performed with Ziehl-Neelsen and Periodic acid-Schiff (PAS) stains was negative. Tissue cultures for bacteria, mycobacteria, and fungi were also negative; however Mantoux test (MT) performed for latent tuberculosis was strongly positive. Sputum for acid fast bacilli was negative, and serology for human immuno-deficiency virus (HIV)-1 and HIV-2 was nonreactive. A chest x-ray and ultrasound of the abdomen did not reveal any abnormality. Although the morphology of skin lesions did not favor classic lupus vulgaris (LV), considering the endemicity of tuberculosis in India, positive results of Mantoux test, and a dermal epithelioid granuloma, the patient was prescribed antitubercular therapy (ATT), comprising isoniazid, rifampicin, ethambutol, and pyrazinamide. Dramatic response was observed after 2 months, and complete healing with residual scarring took place in next 4 months (Figure 1B).
Topics: Female; Humans; Antitubercular Agents; Ethambutol; Isoniazid; Pyrazinamide; Skin Neoplasms
PubMed: 38051246
DOI: No ID Found