-
Journal of Clinical Medicine May 2024: Since metabolic diseases and atherosclerotic vascular events are firmly associated, herein we investigate changes in central microcirculation and...
: Since metabolic diseases and atherosclerotic vascular events are firmly associated, herein we investigate changes in central microcirculation and atherosclerosis-related body fat distribution in patients with type 2 diabetes mellitus and obesity. Resting brain perfusion single-photon emission computed tomography (SPECT) imaging with Technetium-99m hexamethylpropylene amine oxime ([Tc]Tc-HMPAO SPECT) was performed, and the breath-holding index (BHI) and carotid intima-media thickness (cIMT) were measured to characterise central microcirculation. Besides CT-based abdominal fat tissue segmentation, C-peptide level, glycaemic and anthropometric parameters were registered to search for correlations with cerebral blood flow and vasoreactivity. : Although no significant difference was found between the resting cerebral perfusion of the two patient cohorts, a greater blood flow increase was experienced in the obese after the breath-holding test than in the diabetics ( < 0.05). A significant positive correlation was encountered between resting and provocation-triggered brain perfusion and C-peptide levels ( < 0.005). BMI and cIMT were negatively correlated (rho = -0.27 and -0.23 for maximum and mean cIMT, respectively), while BMI and BHI showed a positive association (rho = 0.31 and rho = 0.29 for maximum and mean BHI, respectively), which could be explained by BMI-dependent changes in fat tissue distribution. cIMT demonstrated a disproportional relationship with increasing age, and higher cIMT values were observed for the men. Overall, C-peptide levels and circulatory parameters seem to be strong applicants to predict brain microvascular alterations and related cognitive decline in such patient populations.
PubMed: 38792441
DOI: 10.3390/jcm13102900 -
Science Advances May 2024State-of-the-art technology for cyclohexanone oxime production typically demands elevated temperature and pressure, along with the utilization of expensive hydroxylamine...
State-of-the-art technology for cyclohexanone oxime production typically demands elevated temperature and pressure, along with the utilization of expensive hydroxylamine sulfate or oxidants. Here, we propose an electrochemistry-assisted cascade strategy for the efficient cyclohexanone ammoximation under ambient conditions by using in situ cathode-generated green oxidants of reactive oxygen species (ROS) such as OOH* and HO. This electrochemical reaction can take place at the cathode, achieving over 95% yield, 99% selectivity of cyclohexanone oxime, and an electron-to-oxime (ETO) efficiency of 96%. Mechanistic analysis reveals that, in addition to the direct ammoximation by in situ-generated OOH* by electrocatalytic ORR, Ti-MOR also play a major role in capturing OOH* directly and converting the in situ-generated HO to OOH*, thus accelerating the ORR-coupled cascade production of cyclohexanone oxime. This work paves a mild, economical, and sustainable energy-efficient electrocatalytic route for the oxime production using oxygen, ammonium bicarbonate, and cyclohexanone.
PubMed: 38787946
DOI: 10.1126/sciadv.ado1755 -
Biomolecules May 2024Olesoxime, a cholesterol derivative with an oxime group, possesses the ability to cross the blood-brain barrier, and has demonstrated excellent safety and tolerability...
Olesoxime, a cholesterol derivative with an oxime group, possesses the ability to cross the blood-brain barrier, and has demonstrated excellent safety and tolerability properties in clinical research. These characteristics indicate it may serve as a centrally active ligand of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), whose disruption of activity with organophosphate compounds (OP) leads to uncontrolled excitation and potentially life-threatening symptoms. To evaluate olesoxime as a binding ligand and reactivator of human AChE and BChE, we conducted kinetic studies with the active metabolite of insecticide parathion, paraoxon, and the warfare nerve agents sarin, cyclosarin, tabun, and VX. Our results showed that both enzymes possessed a binding affinity for olesoxime in the mid-micromolar range, higher than the antidotes in use (i.e., 2-PAM, HI-6, etc.). While olesoxime showed a weak ability to reactivate AChE, cyclosarin-inhibited BChE was reactivated with an overall reactivation rate constant comparable to that of standard oxime HI-6. Moreover, in combination with the oxime 2-PAM, the reactivation maximum increased by 10-30% for cyclosarin- and sarin-inhibited BChE. Molecular modeling revealed productive interactions between olesoxime and BChE, highlighting olesoxime as a potentially BChE-targeted therapy. Moreover, it might be added to OP poisoning treatment to increase the efficacy of BChE reactivation, and its cholesterol scaffold could provide a basis for the development of novel oxime antidotes.
Topics: Humans; Butyrylcholinesterase; Acetylcholinesterase; Ligands; Oximes; Cholinesterase Reactivators; Cholinesterase Inhibitors; Cholestenones; Kinetics; Sarin; GPI-Linked Proteins; Antidotes; Cholesterol; Organophosphorus Compounds
PubMed: 38785995
DOI: 10.3390/biom14050588 -
RSC Medicinal Chemistry May 2024A simple assay involving the measurement of IL-6 production in human synovial fibroblasts from rheumatoid arthritis patients has been utilised to select candidates from...
A new class of 7-deazaguanine agents targeting autoimmune diseases: dramatic reduction of synovial fibroblast IL-6 production from human rheumatoid arthritis patients and improved performance against murine experimental autoimmune encephalomyelitis.
A simple assay involving the measurement of IL-6 production in human synovial fibroblasts from rheumatoid arthritis patients has been utilised to select candidates from a targeted library of queuine tRNA ribosyltransferase (QTRT) substrates for subsequent screening in murine experimental autoimmune encephalomyelitis (EAE - a model of multiple sclerosis). The activity assay discriminated between poor and excellent 7-deazaguanine QTRT substrates and allowed the identification of several structures which subsequently outperformed the previous lead in EAE. Two molecules were of significant promise: one rigidified analogue of the lead, and another considerably simpler structure incorporating an oxime motif which differs structurally from the lead to a considerable extent. These studies provide data from human cells for the first time and have expanded both the chemical space and current understanding of the structure-activity relationship underpinning the remarkable potential of 7-deazguanines in a Multiple Sclerosis disease model.
PubMed: 38784475
DOI: 10.1039/d4md00028e -
Cell Communication and Signaling : CCS May 2024Extracellular vesicles (EVs) constitute a vital component of intercellular communication, exerting significant influence on metastasis formation and drug resistance...
Extracellular vesicles (EVs) constitute a vital component of intercellular communication, exerting significant influence on metastasis formation and drug resistance mechanisms. Malignant melanoma (MM) is one of the deadliest forms of skin cancers, because of its high metastatic potential and often acquired resistance to oncotherapies. The prevalence of BRAF mutations in MM underscores the importance of BRAF-targeted therapies, such as vemurafenib and dabrafenib, alone or in combination with the MEK inhibitor, trametinib. This study aimed to elucidate the involvement of EVs in MM progression and ascertain whether EV-mediated metastasis promotion persists during single agent BRAF (vemurafenib, dabrafenib), or MEK (trametinib) and combined BRAF/MEK (dabrafenib/trametinib) inhibition.Using five pairs of syngeneic melanoma cell lines, we assessed the impact of EVs - isolated from their respective supernatants - on melanoma cell proliferation and migration. Cell viability and spheroid growth assays were employed to evaluate proliferation, while migration was analyzed through mean squared displacement (MSD) and total traveled distance (TTD) measurements derived from video microscopy and single-cell tracking.Our results indicate that while EV treatments had remarkable promoting effect on cell migration, they exerted only a modest effect on cell proliferation and spheroid growth. Notably, EVs demonstrated the ability to mitigate the inhibitory effects of BRAF inhibitors, albeit they were ineffective against a MEK inhibitor and the combination of BRAF/MEK inhibitors. In summary, our findings contribute to the understanding of the intricate role played by EVs in tumor progression, metastasis, and drug resistance in MM.
Topics: Melanoma; Extracellular Vesicles; Proto-Oncogene Proteins B-raf; Humans; Cell Movement; Cell Line, Tumor; Protein Kinase Inhibitors; Cell Proliferation; Vemurafenib; Pyrimidinones; Pyridones; Imidazoles; Oximes
PubMed: 38778340
DOI: 10.1186/s12964-024-01660-4 -
Carbohydrate Polymers Aug 2024The dynamic interplay between cells and their native extracellular matrix (ECM) influences cellular behavior, imposing a challenge in biomaterial design. Dynamic...
The dynamic interplay between cells and their native extracellular matrix (ECM) influences cellular behavior, imposing a challenge in biomaterial design. Dynamic covalent hydrogels are viscoelastic and show self-healing ability, making them a potential scaffold for recapitulating native ECM properties. We aimed to implement kinetically and thermodynamically distinct crosslinkers to prepare self-healing dynamic hydrogels to explore the arising properties and their effects on cellular behavior. To do so, aldehyde-substituted hyaluronic acid (HA) was synthesized to generate imine, hydrazone, and oxime crosslinked dynamic covalent hydrogels. Differences in equilibrium constants of these bonds yielded distinct properties including stiffness, stress relaxation, and self-healing ability. The effects of degree of substitution (DS), polymer concentration, crosslinker to aldehyde ratio, and crosslinker functionality on hydrogel properties were evaluated. The self-healing ability of hydrogels was investigated on samples of the same and different crosslinkers and DS to obtain hydrogels with gradient properties. Subsequently, human dermal fibroblasts were cultured in 2D and 3D to assess the cellular response considering the dynamic properties of the hydrogels. Moreover, assessing cell spreading and morphology on hydrogels having similar modulus but different stress relaxation rates showed the effects of matrix viscoelasticity with higher cell spreading in slower relaxing hydrogels.
Topics: Hyaluronic Acid; Hydrogels; Humans; Fibroblasts; Schiff Bases; Cross-Linking Reagents; Biocompatible Materials; Extracellular Matrix; Cells, Cultured
PubMed: 38763720
DOI: 10.1016/j.carbpol.2024.122173 -
PloS One 2024Recently, several randomized controlled trials (RCTs) of fluvoxamine have been successfully conducted for the treatment of patients with coronavirus disease 2019... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Recently, several randomized controlled trials (RCTs) of fluvoxamine have been successfully conducted for the treatment of patients with coronavirus disease 2019 (COVID-19). This systematic review and meta-analysis was to evaluate the efficacy and safety of fluvoxamine in patients with COVID-19.
METHODS
MEDLINE, EMBASE, Cochrane Library and clinicaltrials.gov were searched for RCTs which were performed to evaluate fluvoxamine and placebo up to January 31, 2024. Review Manager 5.3 was used to perform meta-analysis. The risk ratio (RR) and mean difference (MD) was analyzed and calculated with a random effect model.
RESULTS
We pooled 4,711 participants from six RCTs (2,382 in the fluvoxamine group and 2,329 in the placebo group). Compared to the placebo group, the fluvoxamine group had a significantly lower rate of clinical deterioration (RR, 0.73; P = 0.004; 95% CI, 0.59 to 0.90; I2 = 0%) and hospitalization (RR, 0.76; P = 0.04; 95% CI, 0.59 to 0.99; I2 = 0%). In the meantime, compared with the placebo group, fluvoxamine group did not show any higher risk of AEs (P = 0.13 and 0.91, respectively) in safety outcomes analysis. The subgroup analysis showed that fluvoxamine treatment performed more than 200 mg daily appears to be more effective than those performed less than 200 mg daily in reducing clinical deterioration and hospitalization risks, while not exhibiting higher AE and SAE risks than placebo group.
CONCLUSION
Fluvoxamine for patients with COVID-19, especially those who take 200 mg or more daily, is superior to the placebo group in reducing clinical deterioration and hospitalization, and did not show any higher risk of AEs and SAEs in safety concerns, which might be a promising intervention for COVID-19.
Topics: Fluvoxamine; Humans; COVID-19 Drug Treatment; Randomized Controlled Trials as Topic; SARS-CoV-2; COVID-19; Treatment Outcome; Hospitalization
PubMed: 38753761
DOI: 10.1371/journal.pone.0300512 -
NPJ Systems Biology and Applications May 2024In vertical inhibition treatment strategies, multiple components of an intracellular pathway are simultaneously inhibited. Vertical inhibition of the BRAFV600E-MEK-ERK...
In vertical inhibition treatment strategies, multiple components of an intracellular pathway are simultaneously inhibited. Vertical inhibition of the BRAFV600E-MEK-ERK signalling pathway is a standard of care for treating BRAFV600E-mutated melanoma where two targeted cancer drugs, a BRAFV600E-inhibitor, and a MEK inhibitor, are administered in combination. Targeted therapies have been linked to early onsets of drug resistance, and thus treatment strategies of higher complexities and lower doses have been proposed as alternatives to current clinical strategies. However, finding optimal complex, low-dose treatment strategies is a challenge, as it is possible to design more treatment strategies than are feasibly testable in experimental settings. To quantitatively address this challenge, we develop a mathematical model of BRAFV600E-MEK-ERK signalling dynamics in response to combinations of the BRAFV600E-inhibitor dabrafenib (DBF), the MEK inhibitor trametinib (TMT), and the ERK-inhibitor SCH772984 (SCH). From a model of the BRAFV600E-MEK-ERK pathway, and a set of molecular-level drug-protein interactions, we extract a system of chemical reactions that is parameterised by in vitro data and converted to a system of ordinary differential equations (ODEs) using the law of mass action. The ODEs are solved numerically to produce simulations of how pathway-component concentrations change over time in response to different treatment strategies, i.e., inhibitor combinations and doses. The model can thus be used to limit the search space for effective treatment strategies that target the BRAFV600E-MEK-ERK pathway and warrant further experimental investigation. The results demonstrate that DBF and DBF-TMT-SCH therapies show marked sensitivity to BRAFV600E concentrations in silico, whilst TMT and SCH monotherapies do not.
Topics: Proto-Oncogene Proteins B-raf; Humans; Pyridones; MAP Kinase Signaling System; Melanoma; Imidazoles; Protein Kinase Inhibitors; Pyrimidinones; Oximes; Computer Simulation; Models, Biological; Signal Transduction; Mutation; Antineoplastic Agents; Drug Resistance, Neoplasm
PubMed: 38750040
DOI: 10.1038/s41540-024-00379-9 -
Molecules (Basel, Switzerland) Apr 2024Borane-trimethylamine complex (MeN·BH; BTM) is the most stable of the amine-borane complexes that are commercially available, and it is cost-effective. It is a valuable... (Review)
Review
Borane-trimethylamine complex (MeN·BH; BTM) is the most stable of the amine-borane complexes that are commercially available, and it is cost-effective. It is a valuable reagent in organic chemistry with applications in the reduction of carbonyl groups and carbon-nitrogen double bond reduction, with considerable examples in the reduction of oximes, hydrazones and azines. The transfer hydrogenation of aromatic -heterocycles and the selective -monomethylation of primary anilines are further examples of recent applications, whereas the reduction of nitrobenzenes to anilines and the reductive deprotection of -tritylamines are useful tools in the organic synthesis. Moreover, BTM is the main reagent in the regioselective cleavage of cyclic acetals, a reaction of great importance for carbohydrate chemistry. Recent innovative applications of BTM, such as CO utilization as feedstock and radical chemistry by photocatalysis, have extended their usefulness in new reactions. The present review is focused on the applications of borane-trimethylamine complex as a reagent in organic synthesis and has not been covered in previous reviews regarding amine-borane complexes.
PubMed: 38731507
DOI: 10.3390/molecules29092017 -
Molecules (Basel, Switzerland) Apr 2024The synthesis of stereochemically pure oximes, amines, saturated and unsaturated cyanomethyl compounds, and methylaminomethyl compounds at the C9 position in...
The synthesis of stereochemically pure oximes, amines, saturated and unsaturated cyanomethyl compounds, and methylaminomethyl compounds at the C9 position in 3-hydroxy--phenethyl-5-phenylmorphans provided μ-opioid receptor (MOR) agonists with varied efficacy and potency. One of the most interesting compounds, (2-((1,5,9)-5-(3-hydroxyphenyl)-2-phenethyl-2-azabicyclo[3.3.1]nonan-9-yl)acetonitrile), was found to be a potent partial MOR agonist (EC = 2.5 nM, %E = 89.6%), as determined in the forskolin-induced cAMP accumulation assay. Others ranged in potency and efficacy at the MOR, from nanomolar potency with a C9 cyanomethyl compound (EC = 0.85 nM) to its totally inactive diastereomer, and three compounds exhibited weak MOR antagonist activity (the primary amine , the secondary amine , and the cyanomethyl compound ). Many of the compounds were fully efficacious; their efficacy and potency were affected by both the stereochemistry of the molecule and the specific C9 substituent. Most of the MOR agonists were selective in their receptor interactions, and only a few had δ-opioid receptor (DOR) or κ-opioid receptor (KOR) agonist activity. Only one compound, a C9-methylaminomethyl-substituted phenylmorphan, was moderately potent and fully efficacious as a KOR agonist (KOR EC = 18 nM (% E = 103%)).
Topics: Oximes; Stereoisomerism; Structure-Activity Relationship; Amines; Receptors, Opioid, mu; Humans; Animals; Molecular Structure; CHO Cells; Morphinans
PubMed: 38731416
DOI: 10.3390/molecules29091926