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SARS-CoV-2 is the causative agent of the COVID-19 pandemic, the acute respiratory disease which, so far, has led to over 7 million deaths. There are several symptoms associated with SARS-CoV-2 infections which include neurological and psychiatric disorders, at least in the case of pre-Omicron variants. SARS-CoV-2 infection can also promote the onset of glioblastoma in patients without prior malignancies. In this study, we focused on the Envelope protein codified by the virus genome, which acts as viroporin and that is reported to be central for virus propagation. In particular, we characterized the electrophysiological profile of E-protein transfected U251 and HEK293 cells through the patch-clamp technique and FURA-2 measurements. Specifically, we observed an increase in the voltage-dependent (Kv) and calcium-dependent (KCa) potassium currents in HEK293 and U251 cell lines, respectively. Interestingly, in both cellular models, we observed a depolarization of the mitochondrial membrane potential in accordance with an alteration of U251 cell growth. We, therefore, investigated the transcriptional effect of E protein on the signaling pathways and found several gene alterations associated with apoptosis, cytokines and WNT pathways. The electrophysiological and transcriptional changes observed after E protein expression could explain the impact of SARS-CoV-2 infection on gliomagenesis. [ABSTRACT FROM AUTHOR]

In eutocic labor, the autonomic nervous system is dominated by the parasympathetic system, which ensures optimal blood flow to the uterus and placenta. This study is focused on the detection of the quantitative presence of catecholamine (C) neurofibers in the internal uterine orifice (IUO) and in the lower uterine segment (LUS) of the pregnant uterus, which could play a role in labor and delivery. A total of 102 women were enrolled before their submission to a scheduled cesarean section (CS); patients showed a singleton fetus in a cephalic presentation outside labor. During CS, surgeons sampled two serial consecutive full-thickness sections 5 mm in depth (including the myometrial layer) on the LUS and two randomly selected samples of 5 mm depth from the IUO of the cervix. All histological samples were studied to quantify the distribution of A nerve fibers. The authors demonstrated a significant and notably higher concentration of A fibers in the IUO (46 ± 4.8) than in the LUS (21 ± 2.6), showing that the pregnant cervix has a greater concentration of A neurofibers than the at-term LUS. Pregnant women's mechanosensitive pacemakers can operate normally when the body is in a physiological state, which permits normal uterine contractions and eutocic delivery. The increased frequency of C neurofibers in the cervix may influence the smooth muscle cell bundles' activation, which could cause an aberrant mechano-sensitive pacemaker activation–deactivation cycle. Stressful circumstances (anxiety, tension, fetal head position) cause the sympathetic nervous system to become more active, working through these nerve fibers in the gravid cervix. They might interfere with the mechano-sensitive pacemakers, slowing down the uterine contractions and cervix ripening, which could result in dystocic labor. [ABSTRACT FROM AUTHOR]

Introduction: Polycystic ovary syndrome (PCOS) is a common multifactorial and polygenic disorder of the endocrine system, affecting up to 20% of women in reproductive age with a still unknown etiology. Follicular fluid (FF) represents an environment for the normal development of follicles rich in metabolites, hormones and neurotransmitters, but in some instances of PCOS the composition can be different. Vasoactive intestinal peptide (VIP) is an endogenous autonomic neuropeptide involved in follicular atresia, granulosa cell physiology and steroidogenesis. Methods: ELISA assays were performed to measure VIP and estradiol levels in human follicular fluids, while AMH, FSH, LH, estradiol and progesterone in the plasma were quantified by chemiluminescence. UHPLC/QTOF was used to perform the untargeted metabolomic analysis. Results: Our ELISA and metabolomic results show: i) an increased concentration of VIP in follicular fluid of PCOS patients (n=9) of about 30% with respect to control group (n=10) (132 ± 28 pg/ml versus 103 ± 26 pg/ml, p=0,03) in women undergoing in vitro fertilization (IVF), ii) a linear positive correlation (p=0.05, r=0.45) between VIP concentration and serum Anti-Müllerian Hormone (AMH) concentration and iii) a linear negative correlation between VIP and noradrenaline metabolism. No correlation between VIP and estradiol (E2) concentration in follicular fluid was found. A negative correlation was found between VIP and noradrenaline metabolite 3,4-dihydroxyphenylglycolaldehyde (DOPGAL) in follicular fluids. Conclusion: VIP concentration in follicular fluids was increased in PCOS patients and a correlation was found with noradrenaline metabolism indicating a possible dysregulation of the sympathetic reflex in the ovarian follicles. The functional role of VIP as noradrenergic modulator in ovarian physiology and PCOS pathophysiology was discussed. [ABSTRACT FROM AUTHOR]

Oocyte–cumulus cell interaction is essential for oocyte maturation and competence. The bidirectional crosstalk network mediated by gap junctions is fundamental for the metabolic cooperation between these cells. As cumulus cells exhibit a more glycolytic phenotype, they can provide metabolic substrates that the oocyte can use to produce ATP via oxidative phosphorylation. The impairment of mitochondrial activity plays a crucial role in ovarian aging and, thus, in fertility, determining the success or failure of assisted reproductive techniques. This review aims to deepen the knowledge about the electro-metabolic coupling of the cumulus–oocyte complex and to hypothesize a putative role of potassium channel modulators in order to improve fertility, promote intracellular Ca2+ influx, and increase the mitochondrial biogenesis and resulting ATP levels in cumulus cells. [ABSTRACT FROM AUTHOR]

Thermo-oxidative stability testing plays a critical role in accurately predicting shelf life. These tests are performed in real time and under stress conditions, where degradation processes are accelerated by increasing storage conditions. In this study, high-performance liquid chromatography (HPLC) analyses were performed to evaluate the degradation of resveratrol in nutraceutical tablets as a function of time under different storage conditions in terms of temperature and relative humidity (RH), namely 25 °C/60% RH, 30 °C/65% RH, and 40 °C/75% RH. The latter is an accelerated test and is used to estimate shelf life for long-term storage. Resveratrol is present in both pure form and as a solid dispersion on magnesium dihydroxide microparticles (Resv@MDH). Degradation kinetic constants were determined at 25 °C, 30 °C, and 40 °C, and the Arrhenius behavior of the kinetic constants as a function of temperature was verified. The main results of this work are as follows: (i) the stability of resveratrol in nutraceutical tablets is affected by temperature; (ii) the dependence of the kinetic constants on temperature does not follow the Arrhenius equation, determining an overestimation of the degradation rate at 25 °C; in this regard a modified version of the Arrhenius equation that takes into account the deviation from linearity has been used to estimate the dependence of the kinetic constant on the temperature. These results suggest that accelerated testing does not provide a general model for predicting the shelf life of foods and dietary supplements. The reason may be due to possible matrix effects that result in different degradation mechanisms depending on the temperature. In this regard, symmetry relationships in the kinetics of chemical reactions resulting from microscopic reversibility and their relationship to the deviation from the Arrhenius equation are discussed. However, further research is needed to characterize the degradation mechanisms at different temperatures. The results of these studies would allow accurate prediction of food degradation to improve food safety and risk management and reduce food waste. In addition, knowledge of stability processes is necessary to ensure the maintenance of physiological processes by dietary supplements. [ABSTRACT FROM AUTHOR]

Human glioblastoma is probably the most malignant and aggressive among cerebral tumors, of which it represents approximately 80% of the reported cases, with an overall survival rate that is quite low. Current therapies include surgery, chemotherapy, and radiotherapy, with associated consistent side effects and low efficacy. The hardness in reaching the site of action, and overcoming the blood–brain barrier, is a major limitation of pharmacological treatments. In this paper, we report the synthesis and characterization of ZIF-90 (ZIF, Zeolitic Imidazolate Framework) nanoparticles as putative carriers of anticancer drugs to the brain. In particular, we successfully evaluated the biocompatibility of these nanoparticles, their stability in body fluids, and their ability to uptake in U251 human glioblastoma cell lines. Furthermore, we managed to synthesize ZIF-90 particles loaded with berberine, an alkaloid reported as a possible effective adjuvant in the treatment of glioblastoma. These findings could suggest ZIF-90 as a possible new strategy for brain cancer therapy and to study the physiological processes present in the central nervous system. [ABSTRACT FROM AUTHOR]

Bile acids have emerged as versatile signalling compounds of a complex network of nuclear and membrane receptors regulating various endocrine and paracrine functions. The elucidation of the interconnection between the biological pathways under the bile acid control and manifestations of hepatic and metabolic diseases have extended the scope of this class of steroids for in vivo investigations. In this framework, the design and synthesis of novel biliary derivatives able to modulate a specific receptor requires a deep understanding of both structure-activity and structure-property relationships of bile acids. In this paper, we report the preparation and the critical micellization concentration evaluation of a series of hyodeoxycholic acid derivatives characterized by a diverse side chain length and by the presence of a methyl group at the alpha position with respect to the terminal carboxylic acid moiety. The data collected are instrumental to extend on a quantitative basis, the knowledge of the current structure-property relationships of bile acids and will be fruitful, in combination with models of receptor activity, to design and prioritize the synthesis of novel pharmacokinetically suitable ligands useful in the validation of bile acid-responsive receptors as therapeutic targets. [ABSTRACT FROM AUTHOR]

Abstract: A new divergent synthesis of DAF-12 ligands, namely Δ4- and Δ7-dafachronic acid, is described starting from the natural bile acid hyodeoxycholic acid. Homologation of the side chain followed by stereoselective reduction of the Δ24 olefinic linkage, 6α-dehydroxylation and C3-oxidation affords dafachronic acids in good yields and high diastereoselectivity making this approach easily accessible and scalable. [Copyright &y& Elsevier]

γ-Hydroxybutyric acid (GHB) is a psychotropic compound endogenous to the brain. Despite its potential physiological significance, the complete molecular mechanisms of action remain unexplained. To facilitate the isolation and identification of the high-affinity GHB binding site, we herein report the design and synthesis of the first 125I-labeled radioligands in the field, one of which contains a photoaffinity label which enables it to bind irreversibly to the high-affinity GHB binding sites. [ABSTRACT FROM AUTHOR]

Based on low solubility in water and high membrane permeability, resveratrol is collocated in the second class of the Biopharmaceutical Classification System, with limited absorption derived from a low dissolution rate. Solid microdispersion of resveratrol supported by magnesium dihydroxide (Resv@MDH, trademark Revifast®) represents a physical mixture of resveratrol (30% w/w) and magnesium dihydroxide (70% w/w) obtained by traditional techniques, such as mixing and micronization under appropriate conditions. Establishing the wide use of Revifast® in food supplements, in the present work we deepen its physicochemical characterization by using diffractometric and infrared analysis. No novel species are found in the Resv@MDH mixture except magnesium dihydroxide and resveratrol extracted from Polygonum cuspidatum. The results herein reported strengthened the safety of Revifast® ingredients for resveratrol-based food supplements. [ABSTRACT FROM AUTHOR]

ATP-sensitive potassium (KATP) channels play a prominent role in controlling cardiovascular function. In this paper, a novel series of 4-(1-oxo-2-cyclopentenyl)-1,4-benzothiazine derivatives modified at the C-2, and C-6 positions were synthesized as openers of vascular KATP channels. Most of the tested compounds evoked vasorelaxing effects on rat aortic rings and membrane hyperpolarization in human vascular smooth muscle cells, with potency similar or superior to that of the reference levcromakalim (LCRK). The selective KATP blocker glibenclamide antagonized the above vascular effects, confirming that KATP channels are closely involved in the mechanism of action. The experimental results confirmed the 1,4-benzothiazine nucleus as an optimal scaffold for activators of vascular KATP channels; moreover, the high level of potency exhibited by the 6-acetyl substituted benzothiazine 8, along with the lack of any significant interference with insulin secretion from pancreatic β-cells, paves the way to further develop a new series of potent activators of vascular KATP channels.

Grounding on our former 3D QSAR studies, a knowledge-based screen of natural bile acids from diverse animal species has led to the identification of avicholic acid as a selective but weak TGR5 agonist. Chemical modifications of this compound resulted in the disclosure of 6α-ethyl-16-epi-avicholic acid that shows enhanced potency at TGR5 and FXR receptors. The synthesis, biological appraisals, and structure-activity relationships of this series of compounds are herein described. Moreover, a thorough physicochemical characterization of 6α-ethyl-16-epi-avicholic acid as compared to naturally occurring bile acids is reported and discussed.

γ-Hydroxybutyric acid (GHB) is a therapeutic drug, a drug of abuse, and an endogenous substance that binds to low- and high-affinity sites in the mammalian brain. To target the specific GHB binding sites, we have developed a (125)I-labeled GHB analog and characterized its binding in rat brain homogenate and slices. Our data show that [(125)I]4-hydroxy-4-[4-(2-iodobenzyloxy)phenyl]butanoate ([(125)I]BnOPh-GHB) binds to one site in rat brain cortical membranes with low nanomolar affinity (K(d), 7 nM; B(max), 61 pmol/mg protein). The binding is inhibited by GHB and selected analogs, but not by γ-aminobutyric acid. Autoradiography using horizontal slices from rat brain demonstrates the highest density of binding in hippocampus and cortical regions and the lowest density in the cerebellum. Altogether, the findings correlate with the labeling and brain regional distribution of high-affinity GHB sites or [(3)H](E,RS)-(6,7,8,9-tetrahydro-5-hydroxy-5H-benzocyclohept-6-ylidene)acetic acid ([(3)H]NCS-382) binding sites. Using a (125)I-labeled photoaffinity derivative of the new GHB ligand, we have performed denaturing protein electrophoresis and detected one major protein band with an apparent mass of 50 kDa from cortical and hippocampal membranes. [(125)I]BnOPh-GHB is the first reported (125)I-labeled GHB radioligand and is a useful tool for in vitro studies of the specific high-affinity GHB binding sites. The related photoaffinity linker [(125)I]4-hydroxy-4-[4-(2-azido-5-iodobenzyloxy)phenyl]butanoate can be used as a probe for isolation of the elusive GHB binding protein.

Bile acids regulate nongenomic actions through the activation of TGR5, a membrane receptor that is G protein-coupled to the induction of adenylate cyclase. In this work, a training set of 43 bile acid derivatives is used to develop a molecular interaction field analysis (MFA) and a 3D-quantitative structure-activity relationship study (3D-QSAR) of TGR5 agonists. The predictive ability of the resulting model is evaluated using an external set of compounds with known TGR5 activity, and six bile acid derivatives whose unknown TGR5 activity is herein assessed with in vitro luciferase assay of cAMP formation. The results show a good predictive model and indicate a statistically relevant degree of correlation between the TGR5 activity and the molecular interaction fields produced by discrete positions of the bile acid scaffold. This information is instrumental to extend on a quantitative basis the current structure-activity relationships of bile acids as TGR5 modulators and will be fruitful to design new potent and selective agonists of the receptor.