scholarly journals New Approaches in Oncology for Repositioning Drugs: The Case of PDE5 Inhibitor Sildenafil

2021 ◽  
Vol 11 ◽  
Author(s):  
Marian Cruz-Burgos ◽  
Alberto Losada-Garcia ◽  
Carlos D. Cruz-Hernández ◽  
Sergio A. Cortés-Ramírez ◽  
Ignacio Camacho-Arroyo ◽  
...  
Keyword(s):  
Therapeutic Potential ◽  
Pde5 Inhibitor ◽  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Systemic Hypertension ◽  
Pde5 Inhibitors ◽  
Development Costs ◽  
Cgmp Signaling ◽  
Molecular Effects ◽  
Approved Drugs

The use of already-approved drugs to treat new or alternative diseases has proved to be beneficial in medicine, because it reduces both drug development costs and timelines. Most drugs can be used to treat different illnesses, due their mechanisms of action are not restricted to one molecular target, organ or illness. Diverging from its original intent offers an opportunity to repurpose previously approved drugs to treat other ailments. This is the case of sildenafil (Viagra), a phosphodiesterase-5 (PDE5) inhibitor, which was originally designed to treat systemic hypertension and angina but is currently commercialized as erectile dysfunction treatment. Sildenafil, tadalafil, and vardenafil are PDE5 inhibitors and potent vasodilators, that extend the physiological effects of nitric oxide and cyclic guanosine monophosphate (cGMP) signaling. Although most of the biological implications of these signaling regulations remain unknown, they offer a large therapeutic potential for several diseases. In addition, some PDE5 inhibitors’ molecular effects seem to play a key role in different illnesses such as kidney disease, diabetes mellitus, and cancer. In this review, we discuss the molecular effects of PDE5 inhibitors and their therapeutic repurposing in different types of cancer.

scholarly journals Nitric Oxide-cGMP Signaling in Hypertension

Hypertension ◽  
2020 ◽  
Vol 76 (4) ◽  
pp. 1055-1068
Author(s):  
Ehsan Ataei Ataabadi ◽  
Keivan Golshiri ◽  
Annika Jüttner ◽  
Guido Krenning ◽  
A.H. Jan Danser ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Drug Targets ◽  
Soluble Guanylyl Cyclase ◽  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Protein Kinase G ◽  
Current Status ◽  
Systemic Hypertension ◽  
Pharmacological Intervention ◽  
Cgmp Signaling

For the treatment of systemic hypertension, pharmacological intervention in nitric oxide-cyclic guanosine monophosphate signaling is a well-explored but unexploited option. In this review, we present the identified drug targets, including oxidases, mitochondria, soluble guanylyl cyclase, phosphodiesterase 1 and 5, and protein kinase G, important compounds that modulate them, and the current status of (pre)clinical development. The mode of action of these compounds is discussed, and based upon this, the clinical opportunities. We conclude that drugs that directly target the enzymes of the nitric oxide-cyclic guanosine monophosphate cascade are currently the most promising compounds, but that none of these compounds is under investigation as a treatment option for systemic hypertension.

The nitric oxide–cGMP signaling pathway plays a significant role in tolerance to the analgesic effect of morphine

2011 ◽  
Vol 89 (2) ◽  
pp. 89-95 ◽  
Author(s):  
Ercan Ozdemir ◽  
Ihsan Bagcivan ◽  
Nedim Durmus ◽  
Ahmet Altun ◽  
Sinan Gursoy
Keyword(s):  
Nitric Oxide ◽  
Analgesic Effect ◽  
Soluble Guanylate Cyclase ◽  
Morphine Tolerance ◽  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Albino Rats ◽  
Tail Flick ◽  
Analgesic Effects ◽  
Cgmp Signaling

Although the phenomenon of opioid tolerance has been widely investigated, neither opioid nor nonopioid mechanisms are completely understood. The aim of the present study was to investigate the role of the nitric oxide (NO)–cyclic guanosine monophosphate (cGMP) pathway in the development of morphine-induced analgesia tolerance. The study was carried out on male Wistar albino rats (weighing 180–210 g; n = 126). To develop morphine tolerance, animals were given morphine (50 mg/kg; s.c.) once daily for 3 days. After the last dose of morphine was injected on day 4, morphine tolerance was evaluated. The analgesic effects of 3-(5′-hydroxymethyl-2′-furyl)-1-benzylindazole (YC-1), BAY 41-2272, S-nitroso-N-acetylpenicillamine (SNAP), NG-nitro-l-arginine methyl ester (L-NAME), and morphine were considered at 15 or 30 min intervals (0, 15, 30, 60, 90, and 120 min) by tail-flick and hot-plate analgesia tests (n = 6 in each study group). The results showed that YC-1 and BAY 41-2272, a NO-independent activator of soluble guanylate cyclase (sGC), significantly increased the development and expression of morphine tolerance, and L-NAME, a NO synthase (NOS) inhibitor, significantly decreased the development of morphine tolerance. In conclusion, these data demonstrate that the nitric oxide–cGMP signal pathway plays a pivotal role in developing tolerance to the analgesic effect of morphine.

Impact of hyperleptinemia during placental ischemia-induced hypertension in pregnant rats

2021 ◽  
Author(s):  
Ana C. Palei ◽  
Hunter L. Martin ◽  
Barbara A. Wilson ◽  
Christopher D. Anderson ◽  
Joey P. Granger ◽  
...  
Keyword(s):  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Sprague Dawley ◽  
Pregnant Rats ◽  
No Donor ◽  
Induced Hypertension ◽  
Cgmp Signaling ◽  
Uterine Perfusion ◽  
Plasma Leptin ◽  
Placental Ischemia

The prevalence of preeclampsia and obesity have increased. While obesity is a major risk factor for preeclampsia, the mechanisms linking these morbidities are poorly understood. Circulating leptin levels increase in proportion to fat mass. Infusion of this adipokine elicits hypertension in non-pregnant rats, but less is known about how hyperleptinemia impacts blood pressure during placental ischemia, an initiating event in the pathophysiology of hypertension in preeclampsia. We tested the hypothesis that hyperleptinemia during reduced uterine perfusion pressure (RUPP) exaggerates placental ischemia-induced hypertension. On gestational day (GD) 14, Sprague-Dawley rats were implanted with osmotic mini-pumps delivering recombinant rat leptin (1 mg/kg per min, i.v.) or vehicle concurrently with the RUPP procedure to induce placental ischemia or Sham. On GD 19, plasma leptin was elevated in Sham+Leptin and RUPP+Leptin. Leptin infusion did not significantly impact mean arterial pressure (MAP) in Sham. MAP was increased in RUPP+Vehicle vs. Sham+Vehicle. In contrast to our hypothesis, placental ischemia-induced hypertension was attenuated by leptin infusion. To examine potential mechanisms for attenuation of RUPP-induced hypertension during hyperleptinemia, endothelial-dependent vasorelaxation to acetylcholine was similar between Sham and RUPP; however, endothelial-independent vasorelaxation to the nitric oxide (NO)-donor, sodium nitroprusside, was increased in Sham and RUPP. These findings suggest that NO/cyclic guanosine monophosphate (cGMP) signaling was increased in the presence of hyperleptinemia. Plasma cGMP was elevated in Sham and RUPP hyperleptinemic groups compared to vehicle groups but plasma and vascular NO metabolites were reduced. These data suggest that hyperleptinemia during placental ischemia attenuates hypertension by compensatory increases in NO/cGMP signaling.

The cGMP system: components and function

2020 ◽  
Vol 401 (4) ◽  
pp. 447-469 ◽  
Author(s):  
Franz Hofmann
Keyword(s):  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Signaling System ◽  
Pde Inhibitors ◽  
Mammalian Tissues ◽  
System Components ◽  
Cgmp Signaling ◽  
Dependent Protein ◽  
Successful Approach ◽  
And Function

AbstractThe cyclic guanosine monophosphate (cGMP) signaling system is one of the most prominent regulators of a variety of physiological and pathophysiological processes in many mammalian and non-mammalian tissues. Targeting this pathway by increasing cGMP levels has been a very successful approach in pharmacology as shown for nitrates, phosphodiesterase (PDE) inhibitors and stimulators of nitric oxide-guanylyl cyclase (NO-GC) and particulate GC (pGC). This is an introductory review to the cGMP signaling system intended to introduce those readers to this system, who do not work in this area. This article does not intend an in-depth review of this system. Signal transduction by cGMP is controlled by the generating enzymes GCs, the degrading enzymes PDEs and the cGMP-regulated enzymes cyclic nucleotide-gated ion channels, cGMP-dependent protein kinases and cGMP-regulated PDEs. Part A gives a very concise introduction to the components. Part B gives a very concise introduction to the functions modulated by cGMP. The article cites many recent reviews for those who want a deeper insight.

scholarly journals Audiometry Results and TEOAE and DPOAE Amplitudes in Men Taking a Phosphodiesterase Type 5 Inhibitor for Erectile Dysfunction

2017 ◽  
Vol 96 (7) ◽  
pp. E34-E39 ◽  
Author(s):  
Sertan Öntepeli ◽  
Nuray Bayar Muluk ◽  
Devrim Tuğlu ◽  
Timuçin Şipal
Keyword(s):  
Erectile Dysfunction ◽  
Otoacoustic Emissions ◽  
Pde5 Inhibitor ◽  
Post Treatment ◽  
Guanosine Monophosphate ◽  
Pde5 Inhibitors ◽  
Cochlear Blood Flow ◽  
Distortion Product ◽  
Phosphodiesterase Type 5 Inhibitor ◽  
Phosphodiesterase Type

We conducted a prospective study of transient evoked otoacoustic emissions (TEOAEs) and distortion-product otoacoustic emissions (DPOAEs) in men who were taking an oral phosphodiesterase type 5 (PDE5) inhibitor for erectile dysfunction. Our study group was made up of 30 men (60 ears), aged 34 to 60 years (mean: 50.9). They were randomly divided into three groups; 10 men were given sildenafil (Viagra) at 50 mg twice a week, 10 were given tadalafil (Cialis) at 20 mg twice a week, and 10 were given vardenafil (Levitra) at 20 mg twice a week. All patients took their drug for 3 weeks, for a total of 6 tablets for each patient. Audiometric tests and TEOAE and DPOAE measurements were performed before and after treatment. Post-treatment audiometry demonstrated improvement in hearing in all three groups. However, post-treatment TEOAE amplitudes and DPOAE amplitudes differed among the three groups; they were significantly higher in the sildenafil group at 1.0 kHz and the same in the tadalafil group; in the vardenafil group, the DPOAE amplitude was significantly lower at 3.0 kHz while there was no change in the TEOAE amplitude. We speculate that the possible mechanism for these findings is that PDE5 inhibitors block degradation of cyclic guanosine monophosphate (cGMP) and induce dilation of the cochlear microcirculation, resulting in an increase in cochlear blood flow. We also believe that the decrease in DPOAE amplitudes at 3.0 kHz seen in the vardenafil group may be related to an accumulation of nitric oxide/cGMP complex, which is toxic to the cochlea; however, since there was no change in TEOAE amplitude in the vardenafil group, this influence may be minimal. Further studies are needed to obtain a more comprehensive assessment of the effects of PDE5 inhibitors on hearing with the use of higher doses and longer durations of therapy.

scholarly journals The effect of PDE5 inhibitors on bone and oxidative damage in ovariectomy-induced osteoporosis

2017 ◽  
Vol 242 (10) ◽  
pp. 1051-1061 ◽  
Author(s):  
Hamit H Alp ◽  
Zübeyir Huyut ◽  
Serkan Yildirim ◽  
Yıldıray Başbugan ◽  
Levent Ediz ◽  
...  
Keyword(s):  
Mass Density ◽  
Public Health Problem ◽  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Protein Kinase G ◽  
Bone Mass Density ◽  
Control Group ◽  
Major Public Health Problem ◽  
Pde5 Inhibitors ◽  
Positive Effects

Osteoporosis is a major public health problem associated with many factors, and it affects more than 50% of women over 50 years old. In the current study, our purpose was to investigate the effects of phosphodiestarase-5 inhibitors on osteoporosis via the nitric oxide/3′,5′-cyclic guanosine monophosphate/protein kinase G signalling pathway. A total of 50 female albino Wistar rats were separated into five groups. The first group was appointed as the healthy control group with no ovariectomy. All animals in the other groups underwent a bilateral ovariectomy. Six months after the ovariectomy, vardenafil, udenafil and tadalafil were given to the third, fourth and fifth groups, respectively, but were not administered to the positive control group (10 mg/kg per day for two months). The bone mineral density values were determined using a densitometry apparatus for all groups pre- and post-ovariectomy as well as after treatment. The levels of nitric oxide, endothelial nitric oxidesynthase, asymmetric dimethylarginine, 3′,5′-cyclic guanosine monophosphate, protein kinase G, phosphodiestarase-5, pyridinoline, deoxypyridinoline, carboxyterminal telopeptide fragments and plasma carboxy terminal propeptide of type I collagen were determined using an enzyme linked immunosorbent assay. The levels of malondialdehyde, 8-hydroxy-2-deoxy guanosine, deoxyguanosine and coenzyme Q10 were determined by a high-performance liquid chromatography assay. Additionally, the right femoral trabecular bone density and the epiphyseal plate were measured in all groups. Angiogenesis was histologically observed in the bone tissue. In addition, we determined that the inhibitors may have caused a positive impact on the increased bone mass density and reduction of bone resorption markers. We also observed the positive effects of these inhibitors on oxidative stress. In conclusion, these phosphodiestarase-5 inhibitors increase angiogenesis in bone tissue and improve the re-formation rate of bone in rats with osteoporosis. Chemical compounds studied in this article Udenafil (PubChem CID: 6918523); Tadalafil (PubChem CID: 110635); Vardanafil (PubCham CID: 110634). Impact statement The results in our study appear to establish the osteoporosis model and provide evidence of the positive effects of three separate PDE5 inhibitors (vardenafil, udenafil, and tadalafil). The positive effects of these PDE5 inhibitors are investigated and demonstrated by the bone mass density and bone resorption markers. These effects are associated with significant demonstrated antioxidant activities. Osteoporosis is a significant major public health problem especially in more aged populations. Advances in identifying and understanding new potential therapeutic modalities for this disease are significant. This study provides such an advance.

scholarly journals NMDA receptors and L-arginine/nitric oxide/cyclic guanosine monophosphate pathway contribute to the antidepressant-like effect of Yueju pill in mice

2019 ◽  
Vol 39 (9) ◽  
Author(s):  
Wei Wang ◽  
Tong Zhou ◽  
Rong Jia ◽  
Hailou Zhang ◽  
Yi Zhang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Forced Swim Test ◽  
Specific Inhibitor ◽  
Tail Suspension Test ◽  
Cyclic Guanosine Monophosphate ◽  
Nmda Receptor Antagonist ◽  
No Synthase ◽  
Guanosine Monophosphate ◽  
Immobility Time ◽  
Cgmp Signaling

Abstract The present study aims to evaluate the involvement of N-methyl-d-aspartate receptor and nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) system in antidepressant-like effects of Yueju pill (YJ), a Chinese herbal medicine. The immobility time in tail suspension test (TST) and forced swim test (FST) was used to assess the antidepressant effects. Prior administration of L-arginine (750 mg/kg, intraperitoneal [i.p.]), a NO synthase substrate that enhances NO signaling or sildenafil (5 mg/kg, i.p.), a phosphodiesterase 5 inhibitor that enhances cGMP, blunted the antidepressant-like activity of YJ (2.7 g/kg, i.g.). Co-treatment of ineffective dose of YJ (1.35 g/kg, i.g.) with one of the reagents that suppress the NO/cGMP signaling, including methylene blue (10 mg/kg, i.p.), an inhibitor of NO synthase; 7-NI (7-nitroinidazole, 30 mg/kg, i.p.), an nNOS specific inhibitor; L-NAME (10 mg/kg, i.p.), a non-specific inhibitor of NO synthase; and MK-801 (0.05 mg/kg, i.p.), an NMDA receptor antagonist, reduced the immobility time in TST and FST, compared with those in vehicle or single drug treatment groups. Neither above drugs alone or co-administrated with YJ affected locomotor activity or anxiety behavior in open field test. Thus, our results suggest that the antidepressant-like action of YJ may depend on the inhibition of NMDA/NO/cGMP pathway.

scholarly journals Rap1GAP2 is a new GTPase-activating protein of Rap1 expressed in human platelets

Blood ◽  
2005 ◽  
Vol 105 (8) ◽  
pp. 3185-3192 ◽  
Author(s):  
Jan Schultess ◽  
Oliver Danielewski ◽  
Albert P. Smolenski
Keyword(s):  
Platelet Aggregation ◽  
Splice Variants ◽  
Cyclic Guanosine Monophosphate ◽  
Human Platelets ◽  
Guanosine Monophosphate ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Gtpase Activating Protein ◽  
Guanine Nucleotide Binding Protein ◽  
Cgmp Signaling

AbstractThe Ras-like guanine-nucleotide–binding protein Rap1 controls integrin αIIbβ3 activity and platelet aggregation. Recently, we have found that Rap1 activation can be blocked by the nitric oxide/cyclic guanosine monophosphate (NO/cGMP) signaling pathway by type 1 cGMP-dependent protein kinase (cGKI). In search of possible targets of NO/cGMP/cGKI, we studied the expression of Rap1-specific GTPase-activating proteins (GAPs) and guanine nucleotide exchange factors (GEFs) in platelets. We could detect mRNAs for a new protein most closely related to Rap1GAP and for postsynaptic density-95 discs-large and zona occludens protein 1 (PDZ)–GEF1 and CalDAG-GEFs I and III. Using 5′–rapid amplification of cDNA ends (RACE), we isolated the complete cDNA of the new GAP encoding a 715-amino acid protein, which we have termed Rap1GAP2. Rap1GAP2 is expressed in at least 3 splice variants, 2 of which are detectable in platelets. Endogenous Rap1GAP2 protein partially colocalizes with Rap1 in human platelets. In transfected cells, we show that Rap1GAP2 exhibits strong GTPase-stimulating activity toward Rap1. Rap1GAP2 is highly phosphorylated, and we have identified cGKI as a Rap1GAP2 kinase. cGKI phosphorylates Rap1GAP2 exclusively on serine 7, a residue present only in the platelet splice variants of Rap1GAP2. Phosphorylation of Rap1GAP2 by cGKI might mediate inhibitory effects of NO/cGMP on Rap1. Rap1GAP2 is the first GTPase-activating protein of Rap1 found in platelets and is likely to have an important regulatory role in platelet aggregation.

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