Identification of G-quadruplex DNA/RNA binders: Structure-based virtual screening and biophysical characterization

Background Recent findings demonstrated that, in mammalian cells, telomere DNA (Tel) is transcribed into telomeric repeat-containing RNA (TERRA), which is involved in fundamental biological processes, thus representing a promising anticancer target. For this reason, the discovery of dual (as well as selective) Tel/TERRA G-quadruplex (G4) binders could represent an innovative strategy to enhance telomerase inhibition. Methods Initially, docking simulations of known Tel and TERRA active ligands were performed on the 3D coordinates of bimolecular G4 Tel DNA (Tel2) and TERRA (TERRA2). Structure-based pharmacophore models were generated on the best complexes and employed for the virtual screening of ~ 257,000 natural compounds. The 20 best candidates were submitted to biophysical assays, which included circular dichroism and mass spectrometry at different K+ concentrations. Results Three hits were here identified and characterized by biophysical assays. Compound 7 acts as dual Tel2/TERRA2 G4-ligand at physiological KCl concentration, while hits 15 and 17 show preferential thermal stabilization for Tel2 DNA. The different molecular recognition against the two targets was also discussed. Conclusions Our successful results pave the way to further lead optimization to achieve both increased selectivity and stabilizing effect against TERRA and Tel DNA G4s. General significance The current study combines for the first time molecular modelling and biophysical assays applied to bimolecular DNA and RNA G4s, leading to the identification of innovative ligand chemical scaffolds with a promising anticancer profile. This article is part of a Special Issue entitled "G-quadruplex" Guest Editor: Dr. Concetta Giancola and Dr. Daniela Montesarchio

Partial least squares path modelling for the evaluation of patients' satisfaction after thoracic surgical procedures☆

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Acute hemodynamic effects of inhaled nitric oxide, dobutamine and a combination of the two in patients with mild to moderate secondary pulmonary hypertension

INTRODUCTION: The use of low-dose dobutamine to maintain hemodynamic stability in pulmonary hypertension may have a detrimental effect on gas exchange. The aim of this study was to investigate whether inhaled nitric oxide (INO), dobutamine and a combination of the two have beneficial effects in patients with end-stage airway lung disease and pulmonary hypertension. METHOD: Hemodynamic evaluation was assessed 10 min after the administration of each drug and of their combination, in 28 candidates for lung transplantation. RESULTS: Administration of INO caused a reduction in mean pulmonary arterial pressure (MPAP), an increase in PaO(2) with a significant reduction in venous admixture effect (Q(s)/Q(t)).Dobutamine administration caused an increase in cardiac index and MPAP, with a decrease in PaO(2) as a result of a higher Q(s)/Q(t). Administration of a combination of the two drugs caused an increase in the cardiac index without MPAP modification and an increase in PaO(2) and Q(s)/Q(t). CONCLUSION: Dobutamine and INO have complementary effects on pulmonary circulation. Their association may be beneficial in the treatment of patients with mild to moderate pulmonary hypertension

Selenoprotein T as a new positive inotrope in the goldfish, Carassius auratus.

Selenoprotein T (SELENOT) is a thioredoxin-like protein, which mediates oxidoreductase functions via its redox active motif Cys-X-X-Sec. In mammals, SELENOT is expressed during ontogenesis and progressively decreases in adult tissues. In the heart, it is re-expressed after ischemia and induces cardioprotection against ischemia/reperfusion (I/R) injury. SELENOT is present in teleost fish, including the goldfish Carassius auratus. This study aimed to evaluate the cardiac expression of SELENOT, and the effects of exogenous PSELT (a 43-52 SELENOT derived-peptide) on the heart function of C. auratus, a hypoxia tolerance fish model. We found that SELENOT was expressed in cardiac extracts of juvenile and adult fish, located in the sarcoplasmic reticulum (SR) together with calsequestrin-2. Expression increased under acute hypoxia. On ex vivo isolated and perfused goldfish heart preparations, under normoxia, PSELT dose-dependently increased Stroke Volume (SV), Cardiac Output (Q̇), and Stroke Work (SW), by involving cAMP, PKA, L-type calcium channels, SERCA2a pumps, and pAkt. Under hypoxia, PSELT did not affect myocardial contractility. Only at higher concentrations (10−8 -10−7 M) an increase of SV and Q̇ was observed. It also reduced the cardiac expression of 3-NT, a tissue marker of nitrosative stress which increases under low oxygen availability. These data are the first to propose SELENOT 43-52, PSELT, as a cardiac modulator in fish, with a potential protective role under hypoxia

Quercetin derivatives as novel antihypertensive agents: Synthesis and physiological characterization

The antihypertensive flavonol quercetin (Q1) is endowedwith a cardioprotective effect againstmyocardial ischemic damage. Q1 inhibits angiotensin converting enzymeactivity, improves vascular relaxation, and decreases oxidative stress and gene expression. However, the clinical application of this flavonol is limited by its poor bioavailability and low stability in aqueous medium. In the aimto overcome these drawbacks and preserve the cardioprotective effects of quercetin, the present study reports on the preparation of five different Q1 analogs, in which all OH groups were replaced by hydrophobic functional moieties. Q1 derivatives have been synthesized by optimizing previously reported procedures and analyzed by spectroscopic analysis. The cardiovascular properties of the obtained compounds were also investigated in order to evaluate whether chemical modification affects their biological efficacy. The interaction with β-adrenergic receptors was evaluated by molecular docking and the cardiovascular efficacy was investigated on the ex vivo Langendorff perfused rat heart. Furthermore, the bioavailability and the antihypertensive properties of the most active derivative were evaluated by in vitro studies and in vivo administration (1month) on spontaneously hypertensive rats (SHRs), respectively. Among all studied Q1 derivatives, only the ethyl derivative reduced left ventricular pressure (at 10−8M÷10−6Mdoses) and improved relaxation and coronary dilation. NOSs inhibition by L-NAME abolished inotropism, lusitropism and coronary effects. Chronic administration of high doses of this compound on SHR reduced systolic and diastolic pressure. Differently, the acetyl derivative induced negative inotropism and lusitropism (at 10−10M and 10−8 ÷ 10−6 M doses), without affecting coronary pressure. Accordingly, docking studies suggested that these compounds bind both β1/β2-adrenergic receptors. Taking into consideration all the obtained results, the replacement of OHwith ethyl groups seems to improve Q1 bioavailability and stability; therefore, the ethyl derivative could represent a good candidate for clinical use in hypertension

Imaging spontaneous currents in superconducting arrays of pi-junctions

Superconductors separated by a thin tunneling barrier exhibit the Josephson effect that allows charge transport at zero voltage, typically with no phase shift between the superconductors in the lowest energy state. Recently, Josephson junctions with ground state phase shifts of pi proposed by theory three decades ago have been demonstrated. In superconducting loops, pi-junctions cause spontaneous circulation of persistent currents in zero magnetic field, analogous to spin-1/2 systems. Here we image the spontaneous zero-field currents in superconducting networks of temperature-controlled pi-junctions with weakly ferromagnetic barriers using a scanning SQUID microscope. We find an onset of spontaneous supercurrents at the 0-pi transition temperature of the junctions Tpi = 3 K. We image the currents in non-uniformly frustrated arrays consisting of cells with even and odd numbers of pi-junctions. Such arrays are attractive model systems for studying the exotic phases of the 2D XY-model and achieving scalable adiabatic quantum computers.Comment: Pre-referee version. Accepted to Nature Physic

Metastasis-Directed Radiation Therapy with Consolidative Intent for Oligometastatic Urothelial Carcinoma: A Systematic Review and Meta-Analysis

The management of patients with oligometastatic urothelial carcinoma (UC) represents an evolving field in uro-oncology, and the role of metastasis-directed therapies, including metastasectomy and metastasis-directed radiation therapy (MDRT), is gaining increasing attention. Herein, we summarize available evidence about the role of MDRT with consolidative intent in oligometastatic UC patients. A systematic review was performed in December 2021. Six studies involving 158 patients were identified. Most patients (n = 120, 90.2%) had a history of bladder cancer and the most frequent sites of metastases were lymph nodes (n = 61, 52.1%) followed by the lungs (n = 34, 29%). Overall, 144 metastases were treated with MDRT. Median follow-up ranged from 17.2 to 25 months. Local control rates ranged from 57% to 100%. Median Overall Survival (OS) ranged from 14.9 to 51.0 months and median progression-free survival ranged from 2.9 to 10.1 months. Rates of OS at one and two years ranged from 78.9% to 96% and from 26% to 63%, respectively. Treatment-related toxicity was recorded in few patients and in most cases a low-grade toxicity was evident. MDRT with consolidative intent represents a potential treatment option for selected patients with oligometastatic UC

PI3Kδ Inhibition as a Potential Therapeutic Target in COVID-19

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The impact of prostate biopsy on erectile and ejaculatory function: A prospective study

Objective: To evaluate the impact on erectile and ejaculatory function following transrectal ultrasound-guided biopsies of the prostate (TRUS-Bx) in sexually active men. Methods: Monocentric prospective study from May 2021 to January 2022 of consecutive patients with suspected prostate cancer [elevated prostate specific antigen (PSA) level and/or abnormal digital rectal examination] undergoing TRUS-Bx. The 15-item version of the International Index of Erectile Function (IIEF-15), Premature Ejaculation Diagnostic Tool (PDET) and short form of Male Sexual Health Questionnaire (MSHQ-EjD Short Form) were assessed before, one and three months after TRUS-Bx. The primary endpoint was to evaluate the risk of temporary post-biopsy erectile and/or ejaculatory dysfunctions. The statistical significance was set as p value < 0.05. Results: A total of 276 consecutive patients were included in the study. The median age, PSA and biopsy cores were 65 years (IQR 59-69), 7 ng/ml (IQR 5-9.7) and 16 (IQR 12-16), respectively. We compared the IIEF subdomains before TRUS-Bx vs. one or three months: the erectile function (EF) decreased after one month (p<0.001) but recovered after three months (p=0.833); the Orgasmic Function (OF), the Sexual Desire (SD), the Intercourse Satisfaction (IS), the Overall Satisfaction (OS), and Total IIEF decreased significantly after both one and three months compared to pre-biopsy values (p < 0.05). As for ejaculatory function (EjF), PDET, MSHQ-EjD Short Form 1, 2, 3 and MSHQ-EjD Short Form 4 scores decreased significantly after one month (p < 0.001), but they returned to pre-biopsy values after 3 months: p = 0.538, p = 0.071 and p = 0.098, respectively. Conclusions: Our study proved that EF, assessed through IIEF- 15, and ejaculatory function, assessed through PDET and MSHQ-EjD Short Form, were negatively affected by TRUS-Bx one month after the procedure and recovered after three months. Interestingly, the other IIEF-15 subdomains (OF, SD, IS, OS and Total) resulted as significantly reduced also after 3 months: this issue highlights the importance of carefully considering the indication to TRUS-Bx