Vibrational Spectroscopic and Molecular Docking Studies of Amrinone, a Cardiotonic Inotropic Drug-=SUP=-*-=/SUP=-

Amrinone is a class I cardiotonic inotropic agent, which is known to increase the cyclic adenosine monophosphate (cAMP) level by inhibiting the phosphodiesterase 3 (PDE3) enzyme. In this study the theoretically possible stable conformations of the amrinone, was examined first by conformational analysis method and then the obtained most stable conformation was optimized by DFT/wb97xd/6-311++G(d,p) level of theory using Gaussian 03 program. The credibility of the theoretical model was confirmed by comparison of experimental and theoretical vibrational spectra of the title molecule. The fundamental vibrational wavenumbers, IR and Raman intensities of the optimized structure of amrinone were determined using DFT/wb97xd/6-311++G(d,p) level of theory and compared with the experimental vibrational spectra. To investigate the influence of amrinone on cAMP enhancement, the docking simulations towards PDE3B were carried out and the main binding interactions of amrinone with PDE3 were elucidated. Cytochrome P450s (CYPs) are very important phase I metabolizing enzymes. The interaction between amrinone and CYPs (CYP1A2, CYP2C9 and CYP2C19) was investigated by docking simulations. Moreover, molecular docking of the title molecule with different proteins and receptors were studied to reveal potential mechanisms for therapeutic applications. Molecular docking simulations revealed that amrinone showed strong binding affinity to integrins α5β1 (Delta G=-6.6 kcal/mol) and αIIbβ3 (-6.6 kcal/mol), and DNA (-6.5 kcal/mol). The results correlated with its anticancer activity. The drug likeness and ADMET properties of amrinone were analyzed for the prediction of pharmacokinetic profiles. Key words: amrinone, DFT calculations, FTIR, Molecular Docking, ADMET.

Effects of prematuration culture with a phosphodiesterase-3 inhibitor on oocyte morphology and embryo quality in in vitro maturation

Objective: The study assessed the developmental potential of germinal vesicle (GV) oocytes subjected to in vitro maturation (IVM) after prematuration culture with cilostamide (a phosphodiesterase-3 inhibitor) and the impact of cilostamide exposure on the morphology of meiosis II (MII) oocytes and subsequent embryo quality. Methods: In total, 994 oocytes were collected from 63 patients. Among 307 GV oocytes, 140 oocytes were selected for the experimental group and 130 oocytes for the control group. The denuded GV-stage oocytes were cultured for 6 hours with cilostamide in the experimental group and without cilostamide in the control group. After 6 hours, the oocytes in the experimental group were washed and transferred to fresh IVM medium. The maturational status of the oocytes in both groups was examined at 26, 36, and 48 hours. Fertilization was assessed at 18 hours post-intracytoplasmic sperm injection. Embryo quality was assessed on days 3 and 5.Results: In total, 92.1% of the oocytes remained in the GV stage, while 6.4% converted to the MI stage (p<0.01) after cilostamide exposure. In both groups, more MII oocytes were observed at 36 hours (25.8% vs. 21.5%) than at 26 hours (10.8% vs. 14.6%) and 48 hours (13% vs. 7.9%) (p>0.05). With the advenet of cilostamide, blastocyst quality was better in the experimental group than in the control group (p<0.05). Conclusions: Cilostamide effectively blocked nuclear maturation and promoted cytoplasmic growth. Prematuration culture with cilostamide enabled synchronization between cytoplasmic and nuclear maturity, resulting in better blastocyst outcomes.

Dual Activation of Phosphodiesterase 3 and 4 Regulates Basal Cardiac Pacemaker Function and Beyond

The sinoatrial (SA) node is the physiological pacemaker of the heart, and resting heart rate in humans is a well-known risk factor for cardiovascular disease and mortality. Consequently, the mechanisms of initiating and regulating the normal spontaneous SA node beating rate are of vital importance. Spontaneous firing of the SA node is generated within sinoatrial nodal cells (SANC), which is regulated by the coupled-clock pacemaker system. Normal spontaneous beating of SANC is driven by a high level of cAMP-mediated PKA-dependent protein phosphorylation, which rely on the balance between high basal cAMP production by adenylyl cyclases and high basal cAMP degradation by cyclic nucleotide phosphodiesterases (PDEs). This diverse class of enzymes includes 11 families and PDE3 and PDE4 families dominate in both the SA node and cardiac myocardium, degrading cAMP and, consequently, regulating basal cardiac pacemaker function and excitation-contraction coupling. In this review, we will demonstrate similarities between expression, distribution, and colocalization of various PDE subtypes in SANC and cardiac myocytes of different species, including humans, focusing on PDE3 and PDE4. Here, we will describe specific targets of the coupled-clock pacemaker system modulated by dual PDE3 + PDE4 activation and provide evidence that concurrent activation of PDE3 + PDE4, operating in a synergistic manner, regulates the basal cardiac pacemaker function and provides control over normal spontaneous beating of SANCs through (PDE3 + PDE4)-dependent modulation of local subsarcolemmal Ca2+ releases (LCRs).

SMPD3 is a differentially expressed gene in brain metastatic human breast cancer.

Metastasis to the brain is a clinical problem in patients with breast cancer (1-3). We mined published microarray data (4, 5) to compare primary and metastatic tumor transcriptomes for the discovery of genes associated with brain metastasis in humans with metastatic breast cancer. We found that the sphingomyelin phosphodiesterase 3, encoded by SMPD3, was among the genes whose expression was most different in the brain metastases of patients with metastatic breast cancer as compared to primary tumors of the breast. SMPD3 mRNA was present at increased quantities in brain metastatic tissues as compared to primary tumors of the breast. Importantly, expression of SMPD3 in primary tumors was significantly correlated with patient recurrence-free survival. Modulation of SMPD3 expression may be relevant to the biology by which tumor cells metastasize from the breast to the brain in humans with metastatic breast cancer.