Neural stem/progenitor cells from olfactory neuroepithelium collected by nasal brushing as a cell model reflecting molecular and cellular dysfunctions in schizophrenia.

OBJECTIVES: Neural stem/progenitor cells derived from olfactory neuroepithelium (hereafter olfactory neural stem/progenitor cells, ONSPCs) are emerging as a potential tool in the exploration of psychiatric disorders. The present study intended to assess whether ONSPCs could help discern individuals with schizophrenia (SZ) from non-schizophrenic (NS) subjects by exploring specific cellular and molecular features. METHODS: ONSPCs were collected from 19 in-patients diagnosed with SZ and 31 NS individuals and propagated in basal medium. Mitochondrial ATP production, expression of ß-catenin and cell proliferation, which are described to be altered in SZ, were examined in freshly isolated or newly thawed ONSPCs after a few culture passages. RESULTS: SZ-ONSPCs exhibited a lower mitochondrial ATP production and insensitivity to agents capable of positively or negatively affecting ß-catenin expression with respect to NS-ONSPCs. As to proliferation, it declined in SZ-ONSPCs as the number of culture passages increased compared to a steady level of growth shown by NS-ONSPCs. CONCLUSIONS: The ease and safety of sample collection as well as the differences observed between NS- and SZ-ONSPCs, may lay the groundwork for a new approach to obtain biological material from a large number of living individuals and gain a better understanding of the mechanisms underlying SZ pathophysiology.

Symphonies of Growth: Unveiling the Impact of Sound Waves on Plant Physiology and Productivity.

The application of sound wave technology to different plant species has revealed that variations in the Hz, sound pressure intensity, treatment duration, and type of setup of the sound source significantly impact the plant performance. A study conducted on cotton plants treated with Plant Acoustic Frequency Technology (PAFT) highlighted improvements across various growth metrics. In particular, the treated samples showed increases in the height, size of the fourth expanded leaf from the final one, count of branches carrying bolls, quantity of bolls, and weight of individual bolls. Another study showed how the impact of a 4 kHz sound stimulus positively promoted plant drought tolerance. In other cases, such as in transgenic rice plants, GUS expression was upregulated at 250 Hz but downregulated at 50 Hz. In the same way, sound frequencies have been found to enhance the osmotic potential, with the highest observed in samples treated with frequencies of 0.5 and 0.8 kHz compared to the control. Furthermore, a sound treatment with a frequency of 0.4 kHz and a sound pressure level (SPL) of 106 dB significantly increased the paddy rice germination index, as evidenced by an increase in the stem height and relative fresh weight. This paper presents a complete, rationalized and updated review of the literature on the effects of sound waves on the physiology and growth parameters of sound-treated plants.

Allocation of Nutrients and Leaf Turnover Rate in Poplar under Ambient and Enriched Ozone Exposure and Soil Nutrient Manipulation.

An excess of ozone (O3) is currently stressing plant ecosystems and may negatively affect the nutrient use of plants. Plants may modify leaf turnover rates and nutrient allocation at the organ level to counteract O3 damage. We investigated leaf turnover rate and allocation of primary (C, N, P, K) and secondary macronutrients (Ca, S, Mg) under various O3 treatments (ambient concentration, AA, with a daily hourly average of 35 ppb; 1.5 × AA; 2.0 × AA) and fertilization levels (N: 0 and 80 kg N ha-1 y-1; P: 0 and 80 kg N ha-1 y-1) in an O3-sensitive poplar clone (Oxford: Populus maximowiczii Henry × P. berolinensis Dippel) in a Free-Air Controlled Exposure (FACE) experiment. The results indicated that both fertilization and O3 had a significant impact on the nutrient content. Specifically, fertilization and O3 increased foliar C and N contents (+5.8% and +34.2%, respectively) and root Ca and Mg contents (+46.3% and +70.2%, respectively). Plants are known to increase the content of certain elements to mitigate the damage caused by high levels of O3. The leaf turnover rate was accelerated as a result of increased O3 exposure, indicating that O3 plays a main role in influencing this physiological parameter. A PCA result showed that O3 fumigation affected the overall allocation of primary and secondary elements depending on the organ (leaves, stems, roots). As a conclusion, such different patterns of element allocation in plant leaves in response to elevated O3 levels can have significant ecological implications.

Post-COVID-19 and Post-COVID-19 Vaccine Arthritis, Polymyalgia Rheumatica and Horton's Arteritis: A Single-Center Assessment of Clinical, Serological, Genetic, and Ultrasonographic Biomarkers.

The potential role of the COVID-19 vaccine and infection to induce autoimmunity is currently underestimated despite the literature emphasizing arthralgia as a common adverse event. We aimed to study the impact of rheumatological complications post-COVID-19 (PC) and post-COVID-19 vaccine (PCV), comparing undifferentiated arthritis (UA) to Polymyalgia Rheumatica, Horton's Arteritis (PMR-HA) and isolated arthritis to UA with "connective-like" accompanying symptoms. We retrospectively included 109 patients with at least 6 months of follow-up, analyzing serum biomarkers, joint ultrasound (US), lung HRCT, DLCO, and HLA haplotypes. There were 87 UA patients showing increased gastrointestinal and lung involvement (p = 0.021 and p = 0.012), higher anti-spike protein IgG levels (p = 0.003), and anti-SARS-CoV-2 IgG positivity (p = 0.003). Among them, 66 cases progressed to ACR-EULAR 2010 early arthritis after 3 months, whereas PMR-HA patients were more commonly PCV (81.8%, p = 0.008), demonstrating higher CRP (p = 0.007) and ESR (p = 0.006) levels, a lower rate of ANA positivity (p = 0.005), and a higher remission rate after six months (p = 0.050). In UA patients, the prevalent HLA was DRB1*11 and C*07 (36.8% and 42.1%). Serum calprotectin, interleukin-6, and C*07 (p = 0.021, 0.041, 0.018) seemed more specific for isolated UA. Conversely, "connective-like" arthritis showed poorer DLCO (p = 0.041) and more frequent US synovitis (p = 0.041). In conclusion, UA is a frequent common PC and PCV complication and may persist over time when compared to PMR-HA.

MeltSerts technology (brinzolamide ocular inserts via hot-melt extrusion): QbD-steered development, molecular dynamics, in vitro, ex vivo and in vivo studies.

The research work aimed to develop a robust sustained release biocompatible brinzolamide (BRZ)-loaded ocular inserts (MeltSerts) using hot-melt extrusion technology with enhanced solubility for glaucoma management. A 32 rotatable central composite design was employed for the optimization of the MeltSerts to achieve sustained release. The effect of two independent factors was examined: Metolose® SR 90SH-100000SR (HPMC, hydroxypropyl methyl cellulose) and Kolliphor® P 407 (Poloxamer 407, P407). The drug release (DR) of BRZ at 0.5 h and 8 h were adopted as dependent responses. The factorial analysis resulted in an optimum composition of 50.00 % w/w of HPMC and 15.00 % w/w of P407 which gave % DR of 9.11 at 0.5 h and 69.10 at 8 h. Furthermore, molecular dynamic simulations were performed to elucidate various interactions between BRZ, and other formulation components and it was observed that BRZ showed maximum interactions with HPC and HPMC with an occupancy of 92.82 and 52.87 %, respectively. Additionally, molecular docking studies were performed to understand the interactions between BRZ and mucoadhesive polymers with ocular mucin (MUC-1). The results indicated a docking score of only -5.368 for BRZ alone, whereas a significantly higher docking score was observed for the optimized Meltserts -6.977, suggesting enhanced retention time of the optimized MeltSerts. SEM images displayed irregular surfaces, while EDS analysis validated uniform BRZ distribution in the optimized formulation. The results of the ocular irritancy studies both ex vivo and in vivo demonstrated that MeltSerts are safe for ocular use. The results indicate that the developed MeltSerts Technology has the potential to manufacture ocular inserts with cost-effectiveness, one-step processability, and enhanced product quality. Nonetheless, it also offers a once-daily regimen, consequently decreasing the dosing frequency, preservative exposure, and ultimately better glaucoma management.

Terahertz imaging for non-invasive classification of healthy and cimiciato-infected hazelnuts.

The development of new non-invasive approaches able to recognize defective food is currently a lively field of research. In particular, a simple and non-destructive method able to recognize defective hazelnuts, such as cimiciato-infected ones, in real-time is still missing. This study has been designed to detect the presence of such damaged hazelnuts. To this aim, a measurement setup based on terahertz (THz) radiation has been developed. Images of a sample of 150 hazelnuts have been acquired in the low THz range by a compact and portable active imaging system equipped with a 0.14 THz source and identified as Healthy Hazelnuts (HH) or Cimiciato Hazelnut (CH) after visual inspection. All images have been analyzed to find the average transmission of the THz radiation within the sample area. The differences in the distribution of the two populations have been used to set up a classification scheme aimed at the discrimination between healthy and injured samples. The performance of the classification scheme has been assessed through the use of the confusion matrix on 50 samples. The False Positive Rate (FPR) and True Negative Rate (TNR) are 0% and 100%, respectively. On the other hand, the True Positive Rate (TPR) and False Negative Rate (FNR) are 75% and 25%, respectively. These results are relevant from the perspective of the development of a simple, automatic, real-time method for the discrimination of cimiciato-infected hazelnuts in the processing industry.

Mitapivat reprograms the RBC metabolome and improves anemia in a mouse model of hereditary spherocytosis.

Hereditary spherocytosis (HS) is the most common, nonimmune, hereditary, chronic hemolytic anemia after hemoglobinopathies. The genetic defects in membrane function causing HS lead to perturbation of the RBC metabolome, with altered glycolysis. In mice genetically lacking protein 4.2 (4.2-/-; Epb42), a murine model of HS, we showed increased expression of pyruvate kinase (PK) isoforms in whole and fractioned RBCs in conjunction with abnormalities in the glycolytic pathway and in the glutathione (GSH) system. Mitapivat, a PK activator, metabolically reprogrammed 4.2-/- mouse RBCs with amelioration of glycolysis and the GSH cycle. This resulted in improved osmotic fragility, reduced phosphatidylserine positivity, amelioration of RBC cation content, reduction of Na/K/Cl cotransport and Na/H-exchange overactivation, and decrease in erythroid vesicles release in vitro. Mitapivat treatment significantly decreased erythrophagocytosis and beneficially affected iron homeostasis. In mild-to-moderate HS, the beneficial effect of splenectomy is still controversial. Here, we showed that splenectomy improves anemia in 4.2-/- mice and that mitapivat is noninferior to splenectomy. An additional benefit of mitapivat treatment was lower expression of markers of inflammatory vasculopathy in 4.2-/- mice with or without splenectomy, indicating a multisystemic action of mitapivat. These findings support the notion that mitapivat treatment should be considered for symptomatic HS.

Protein Phosphorylation and Redox Status: An as Yet Elusive Dyad in Chronic Lymphocytic Leukemia.

Malignant cells in chronic lymphocytic leukemia (CLL) are characterized by oxidative stress that is related to abundant generation of reactive oxygen species (ROS) by increased mitochondrial oxidative phosphorylation (OXPHOS). Lymphoid tissues have been shown to provide a protective microenvironment that antagonizes the effects of ROS, contributing to establishing redox homeostasis that supports the vitality of CLL cells. In the last few decades, a complex antioxidant machinery has been demonstrated to be activated in CLL cells, including the different superoxide dismutase (SOD) isoforms, the thioredoxin (Trx) system, and the enzyme cascade inducing glutathione (GSH) biosynthesis and recycling, to name a few. Their expression is known to be upregulated by the activation of specific transcription factors, which can be regulated by either oxidative stress or phosphorylation. These two latter aspects have mostly been explored separately, and only recently an increasing body of evidence has been providing reasonable inference that ROS and phosphorylation may cooperate in an interplay that contributes to the survival mechanisms of CLL cells. Here, we present an overview of how oxidative stress and phosphorylation-dependent signals are intertwined in CLL, focusing on transcription factors that regulate the balance between ROS production and scavenging.

Human Sperm Capacitation Involves the Regulation of the Tyr-Phosphorylation Level of the Anion Exchanger 1 (AE1).

Bicarbonate uptake is one of the early steps of capacitation, but the identification of proteins regulating anion fluxes remains elusive. The aim of this study is to investigate the role of sperm solute carrier 4 (SLC4) A1 (spAE1) in the capacitation process. The expression, location, and tyrosine-phosphorylation (Tyr-P) level of spAE1 were assessed. Thereby, it was found that 4,4'-Diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS), an SLC4 family channel blocker, inhibited capacitation in a dose-dependent manner by decreasing acrosome reaction (ARC% 24.5 ± 3.3 vs 64.9 ± 4.3, p < 0.05) and increasing the percentage of not viable cells (NVC%), comparable to the inhibition by I-172, a cystic fibrosis transmembrane conductance regulator (CFTR) blocker (AR% 30.5 ± 4.4 and NVC% 18.6 ± 2.2). When used in combination, a synergistic inhibitory effect was observed with a remarkable increase of the percentage of NVC (45.3 ± 4.1, p < 0.001). spAE1 was identified in sperm membrane as a substrate for Tyr-protein kinases Lyn and Syk, which were identified as both soluble and membrane-bound pools. spAE1-Tyr-P level increased in the apical region of sperm under capacitating conditions and was negatively affected by I-172 or DIDS, and, to a far greater extent, by a combination of both. In conclusion, we demonstrated that spAE1 is expressed in sperm membranes and it is phosphorylated by Syk, but above all by Lyn on Tyr359, which are involved in sperm viability and capacitation.

Oxidation Impacts the Intracellular Signaling Machinery in Hematological Disorders.

The dynamic coordination between kinases and phosphatases is crucial for cell homeostasis, in response to different stresses. The functional connection between oxidation and the intracellular signaling machinery still remains to be investigated. In the last decade, several studies have highlighted the role of reactive oxygen species (ROS) as modulators directly targeting kinases, phosphatases, and downstream modulators, or indirectly acting on cysteine residues on kinases/phosphatases resulting in protein conformational changes with modulation of intracellular signaling pathway(s). Translational studies have revealed the important link between oxidation and signal transduction pathways in hematological disorders. The intricate nature of intracellular signal transduction mechanisms, based on the generation of complex networks of different types of signaling proteins, revealed the novel and important role of phosphatases together with kinases in disease mechanisms. Thus, therapeutic approaches to abnormal signal transduction pathways should consider either inhibition of overactivated/accumulated kinases or homeostatic signaling resetting through the activation of phosphatases. This review discusses the progress in the knowledge of the interplay between oxidation and cell signaling, involving phosphatase/kinase systems in models of globally distributed hematological disorders.

Fam20C-mediated phosphorylation of osteopontin is critical for its secretion but dispensable for its action as a cytokine in the activation of hepatic stellate cells in liver fibrogenesis.

Osteopontin (OPN) is a phosphoglycoprotein secreted into the extracellular matrix upon liver injury, acting as a cytokine stimulates the deposition of fibrillary collagen in liver fibrogenesis. In livers of mice subjected to bile duct ligation (BDL) and in cultured activated hepatic stellate cells (HSCs), we show that OPN, besides being overexpressed, is substantially phosphorylated by family with sequence similarity 20, member C (Fam20C), formerly known as Golgi casein kinase (G-CK), which is exclusively resident in the Golgi apparatus. In both experimental models, Fam20C becomes overactive when associated with a 500-kDa multiprotein complex, as compared with the negligible activity in livers of sham-operated rats and in quiescent HSCs. Fam20C knockdown not only confirmed the role of Fam20C itself in OPN phosphorylation, but also revealed that phosphorylation was essential for OPN secretion. However, OPN acts as a fibrogenic factor independently of its phosphorylation state, as demonstrated by the increased expression of Collagen-I by HSCs incubated with either a phosphorylated or nonphosphorylated form of recombinant OPN. Collectively, our results confirm that OPN promotes liver fibrosis and highlight Fam20C as a novel factor driving this process by favoring OPN secretion from HSCs, opening new avenues for deciphering yet unidentified mechanisms underlying liver fibrogenesis.

THz Water Transmittance and Leaf Surface Area: An Effective Nondestructive Method for Determining Leaf Water Content.

Water availability is a major limiting factor in plant productivity and plays a key role in plant species distribution over a given area. New technologies, such as terahertz quantum cascade lasers (THz-QCLs) have proven to be non-invasive, effective, and accurate tools for measuring and monitoring leaf water content. This study explores the feasibility of using an advanced THz-QCL device for measuring the absolute leaf water content in Corylus avellana L., Laurus nobilis L., Ostrya carpinifolia Scop., Quercus ilex L., Quercus suber L., and Vitis vinifera L. (cv. Sangiovese). A recently proposed, simple spectroscopic technique was used, consisting in determining the transmission of the THz light beam through the leaf combined with a photographic measurement of the leaf area. A significant correlation was found between the product of the leaf optical depth (τ) and the leaf surface area (LA) with the leaf water mass (Mw) for all the studied species (Pearson's r test, p ≤ 0.05). In all cases, the best fit regression line, in the graphs of τLA as a function of Mw, displayed R2 values always greater than 0.85. The method proposed can be combined with water stress indices of plants in order to gain a better understanding of the leaf water management processes or to indirectly monitor the kinetics of leaf invasion by pathogenic bacteria, possibly leading to the development of specific models to study and fight them.

Olfactory neuroepithelium alterations and cognitive correlates in schizophrenia.

BACKGROUND: Few studies have investigated alterations of olfactory neuroepithelium (ONE) as a biomarker of schizophrenia, and none its association with cognitive functioning. METHOD: Fresh ONE cells from twelve patients with schizophrenia and thirteen healthy controls were collected by nasal brushing, cultured in proper media and passed twelve times. Markers of cell proliferation (BrdU incorporation, Cyclin-D1 and p21 protein level) were quantified.Cognitive function was measured using Brief Neuropsychological Examination-2. PRIMARY OUTCOME: proliferation of ONE cells from schizophrenic patients at passage 3. Secondary outcome: association between alteration of cell proliferation and cognitive function. RESULTS: Fresh ONE cells from patients showed a faster cell proliferation than those from healthy controls at passage 3. An opposite trend was observed at passage 9, ONE cells of patients with schizophrenia showing slower cell proliferation as compared to healthy controls. In schizophrenia, overall cognitive function (Spearman's rho -0.657, p < 0.01), verbal memory - immediate recall, with interference at 10 s and 30 s (Spearman's rho from -0.676 to 0.697, all p < 0.01) were inversely associated with cell proliferation at passage 3. CONCLUSION: Fresh ONE cells collected by nasal brushing might eventually represent a tool for diagnosing schizophrenia based upon markers of cell proliferation, which can be easily implemented as single-layer culture. Cell proliferation at passage 3 can be regarded as a promising proxy of cognitive functioning in schizophrenia. Future studies should replicate these findings, and may assess whether ONE alterations are there before onset of psychosis, serving as an early sign in patients with at risk mental state.

Mitochondrial apoptosis is induced by Alkoxy phenyl-1-propanone derivatives through PP2A-mediated dephosphorylation of Bad and Foxo3A in CLL.

Protein phosphatase 2 A (PP2A) is a tumour suppressor whose strong inhibition underlies the phosphorylation-dependent, anti-apoptotic mechanisms in Chronic Lymphocytic Leukemia (CLL). Inactivation of PP2A is due to the cooperative action of the phosphorylation of Y307 of its catalytic subunit by the aberrant cytosolic pool of the Src Family Kinase Lyn and the interaction with its protein inhibitor SET, which is overexpressed in CLL. In this study, we developed a library of compounds, the most potent being the one named CC11, which restores PP2A activity by disrupting the PP2A/SET complex, thereby triggering the mitochondrial pathway of apoptosis. This process involves the recruitment of the pro-apoptotic BH3-only proteins Bad and Bim to mitochondria, the former upon direct dephosphorylation and the latter being newly expressed upon dephosphorylation and activation of its transcription factor FoxO3a. These findings highlight that PP2A antagonizes the prosurvival pathways controlled by Akt, which phosphorylates and thereby suppresses a variety of pro-apoptotic factors and tumour suppressors including Bad and FoxO3a. Furthermore, the PP2A-mediated pro-apoptotic effect of CC11 is synergistically potentiated by the abrogation of Lyn's activity. Our results show that CC11 represents a promising lead compound for a new therapeutic rationale aimed at abrogating the aberrant oncogenic signals in CLL.

Targeted activation of the SHP-1/PP2A signaling axis elicits apoptosis of chronic lymphocytic leukemia cells.

Lyn, a member of the Src family of kinases, is a key factor in the dysregulation of survival and apoptotic pathways of malignant B cells in chronic lymphocytic leukemia. One of the effects of Lyn's action is spatial and functional segregation of the tyrosine phosphatase SHP-1 into two pools, one beneath the plasma membrane in an active state promoting pro-survival signals, the other in the cytosol in an inhibited conformation and unable to counter the elevated level of cytosolic tyrosine phosphorylation. We herein show that SHP-1 activity can be elicited directly by nintedanib, an agent also known as a triple angiokinase inhibitor, circumventing the phospho-S591-dependent inhibition of the phosphatase, leading to the dephosphorylation of pro-apoptotic players such as procaspase-8 and serine/threonine phosphatase 2A, eventually triggering apoptosis. Furthermore, the activation of PP2A by using MP07-66, a novel FTY720 analog, stimulated SHP-1 activity via dephosphorylation of phospho-S591, which unveiled the existence of a positive feedback signaling loop involving the two phosphatases. In addition to providing further insights into the molecular basis of this disease, our findings indicate that the PP2A/SHP-1 axis may emerge as an attractive, novel target for the development of alternative strategies in the treatment of chronic lymphocytic leukemia.

Non-invasive absolute measurement of leaf water content using terahertz quantum cascade lasers.

BACKGROUND: Plant water resource management is one of the main future challenges to fight recent climatic changes. The knowledge of the plant water content could be indispensable for water saving strategies. Terahertz spectroscopic techniques are particularly promising as a non-invasive tool for measuring leaf water content, thanks to the high predominance of the water contribution to the total leaf absorption. Terahertz quantum cascade lasers (THz QCL) are one of the most successful sources of THz radiation. RESULTS: Here we present a new method which improves the precision of THz techniques by combining a transmission measurement performed using a THz QCL source, with simple pictures of leaves taken by an optical camera. As a proof of principle, we performed transmission measurements on six plants of Vitis vinifera L. (cv "Colorino"). We found a linear law which relates the leaf water mass to the product between the leaf optical depth in the THz and the projected area. Results are in optimal agreement with the proposed law, which reproduces the experimental data with 95% accuracy. CONCLUSIONS: This method may overcome the issues related to intra-variety heterogeneities and retrieve the leaf water mass in a fast, simple, and non-invasive way. In the future this technique could highlight different behaviours in preserving the water status during drought stress.

An NBD Derivative of the Selective Rat Toxicant Norbormide as a New Probe for Living Cell Imaging.

Norbormide (NRB) is a unique compound that acts directly on rat vascular myocytes to trigger a contractile process, through an as yet unknown mechanism, which results in the selective contraction of rat peripheral arteries. To gain insight into the mechanisms involved in NRB rat-selective activity, we investigated the subcellular distribution of NRB-AF12, a nitrobenzoxadiazole (NBD)-derivative of NRB, in living NRB-sensitive and NRB-insensitive cells. In both cell types, NRB-AF12 localized to the endoplasmic reticulum (ER), Golgi apparatus, mitochondria, lysosomes, and endosomes; however, in NRB-sensitive cells, the fluorescence also extended to the plasma membrane. NRB-AF12 was rapidly internalized into the cells, could easily be washed out and then reloaded back into the same cells, all with a high degree of reproducibility. Cells exposed for 24 h to NRB-AF12 did not show apparent signs of toxicity, even at concentrations of the dye (10 µM) much higher than those required for fluorescence labeling (500 ηM). The distribution pattern of NRB-AF12 fluorescence was near identical to that of ER-Tracker® (Er-Tr), a fluorescent derivative of glibenclamide, a known KATP channel blocker. Displacement tests did not demonstrate, but at the same time did not rule out the possibility of a common target for ER-Tr, NRB-AF12, NRB, and glibenclamide. On the basis of these results we hypothesize a common target site for NRB-AF12 and ER-Tr, and a similar target profile for NRB and glibenclamide, and propose NRB-AF12 as an alternative fluorescence probe to ER-Tracker. Furthermore, NRB-based fluorescence derivatives could be designed to selectively label single cellular structures.

Fatty Acid-Derived Pro-Toxicants of the Rat Selective Toxicant Norbormide.

Norbormide [5-(α-hydroxy-α-2-pyridylbenzyl)-7-(α-2-pyridylbenzylidene)-5-norbornene-2,3-dicarboximide] (NRB), an existing but infrequently used rodenticide, is known to be uniquely toxic to rats but relatively harmless to other rodents and mammals. However, as an acute vasoactive, NRB has a rapid onset of action which makes it relatively unpalatable to rats, often leading to sublethal uptake and accompanying bait shyness. A series of NRB-derived pro-toxicants (3a - i, 4a - i, and 5a - i) were prepared in an effort to 'mask' this acute response and improve both palatability and efficacy. Their synthesis, in vitro biological evaluation (vasocontractile response in rat vasculature, stability in selected rat media) and palatability/efficacy in Sprague-Dawley, wild Norway, and wild ship rats is described. Most notably, pro-toxicant 3d was revealed to be free of all pre-cleavage vasoconstrictory activity in rat caudal artery and was subsequently demonstrated to release NRB in the presence of rat blood, liver, and pancreatic enzymes. Moreover, it consistently displayed a high level of acceptance by rats in a two-choice bait-palatability and efficacy trial, with accompanying high mortality. On this evidence, fatty acid ester prodrugs would appear to offer a promising platform for the further development of NRB-derived toxicants with enhanced palatability and efficacy profiles.

New Therapeutic Applications of Phosphodiesterase 5 Inhibitors (PDE5-Is).

BACKGROUND: Phosphodiesterase 5 inhibitors (PDE5-Is) sildenafil, vardenafil, tadalafil and the recently approved avanafil represent the first-line choice for both on-demand and chronic treatment of erectile dysfunction (ED). In addition to this, sildenafil and tadalafil, have also been approved for the treatment of pulmonary arterial hypertension. Due to its expression and localization in many tissues, PDE5 and its regulation has been reported to be involved in several other diseases. OBJECTIVE: We aim to provide an updated overview of the emerging therapeutic applications of PDE5-Is besides ED, taking into account the latest ongoing research reports. METHODS: We searched online databases (Pubmed, Reaxys, Scopus) to lay the bases for an accurate, quality criteria-based literature update. We focused our attention on most recent research reports, in particular when supported by pre-clinical and clinical data. RESULTS: The regulation of PDE5 may influence pathological conditions such as, among the others, heart failure, cystic fibrosis, cancer, CNS-related diseases, diabetes and dysfunctions affecting male urinary/reproductive system. CONCLUSION: Sildenafil, vardenafil, tadalafil and the other chemical entities considered PDE5-Is showed overall positive results and significant improvements in the studied disease, thus some discordant results, in particular when comparing pre-clinical and clinical data, have to be pointed out, suggesting that further insights are needed especially to assess the exact molecular pathway underlying.

Semi-synthetic derivatives of natural isoflavones from Maclura pomifera as a novel class of PDE-5A inhibitors.

Natural (iso)flavonoids have been recently reported to inhibit cyclic nucleotide phosphodiesterases (PDEs) and induce vasorelaxation, albeit the results described in the literature are discordant. The cGMP-selective isoform PDE-5A, in particular, represents the target of sildenafil and its analogues in the treatment of erectile dysfunction (ED) and pulmonary hypertension by promoting relaxation in vascular smooth muscle through the activation of the NO/cGMP pathway. We undertook this study to verify if osajin and pomiferin, two natural prenylated isoflavones and major constituents of Maclura pomifera extracts previously investigated for their anticancer, antibacterial and antidiabetic properties, show inhibitory activity on PDE-5A. These two isoflavones were isolated from the plant extracts and then synthetically modified to obtain a set of semi-synthetic derivatives with slight and focused modifications on the natural scaffold. The compounds were at first screened against PDE-5A in vitro and, based on the encouraging results, further tested for their relaxant effect on isolated rat artery rings. Computational docking studies were also carried out to explore the mode of interaction with the target protein. The obtained data were compared to the behaviour of the well-known PDE-5A inhibitor sildenafil. Our results demonstrate that semi-synthetic derivatives of osajin and pomiferin show an inhibitory effect on the isolated enzyme that, for some of the compounds, is accompanied by a vasorelaxant activity. Based on our findings, we propose the here described isoflavones as potential lead compounds for the development, starting from natural scaffolds, of a new class of PDE-5A inhibitors with vasorelaxant properties.