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Wang C, Zhang H, Wang F, Guo J, Yuan J, Hou G, Gao M, Li Z, Zhang Y. Efficacy and safety of PDE5 inhibitors in middle-aged and old patients with and without hypogonadism. Aging Male 2024; 27:2288347. [PMID: 38146937 DOI: 10.1080/13685538.2023.2288347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 11/19/2023] [Indexed: 12/27/2023] Open
Abstract
PURPOSE Although several reviews have evaluated the use of PDE5 inhibitors (PDE5i) for treating erectile dysfunction (ED), their specific use in middle-aged and old patients has not been fully evaluated. Given that elderly patients with ED often have a complex combination of systemic and sexual health risk factors, the safety and efficacy of PDE5i in such a context are hereby reviewed. MATERIALS AND METHODS A thorough examination of existing literature has been conducted on PubMed. RESULTS PDE5i has good safety and efficacy, but the situation is more complex for patients with hypogonadism than those with normal testosterone levels, with reduced responsiveness to PDE5i. In this case, combination therapy with testosterone is recommended, safe and effective. CONCLUSIONS Eliminating or reducing reversible risk factors and controlling or slowing the development of irreversible factors is an important foundation for using PDE5i to treat ED in all patients, especially middle-aged and elderly ones.
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Affiliation(s)
- Chunlin Wang
- Chair of Endocrinology and Medical Sexology (ENDOSEX), Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Hui Zhang
- Chair of Endocrinology and Medical Sexology (ENDOSEX), Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Fu Wang
- Department of Andrology, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Jun Guo
- Department of Andrology, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, China
| | - Jianlin Yuan
- Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Guangdong Hou
- Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Ming Gao
- Department of Andrology, Xi'an Daxing Hospital affiliated to Yan'an University, Xi'an, China
| | - Zheng Li
- Shanghai Key Laboratory of Reproductive Medicine, Department of Andrology, Center for Men's Health, Urologic Medical Center, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yan Zhang
- Department of Infertility and Sexual Medicine, 3rd Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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Vasconcelos PA, Paúl C, Nobre PJ. Biopsychosocial determinants of sexual health in older age: the role of health-related, relationship, and psychosexual factors. J Sex Med 2024; 21:420-429. [PMID: 38490973 DOI: 10.1093/jsxmed/qdae027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 01/26/2024] [Accepted: 02/02/2024] [Indexed: 03/18/2024]
Abstract
BACKGROUND Given the unprecedented aging of the population and the increased focus on overall well-being in older age, investigating the determining factors of sexual well-being in older adults becomes essential as it offers insights into promoting healthy aging and overall quality of life. AIM By applying the biopsychosocial model of sexuality in older age, we aimed to identify the role of biomedical and psychosocial factors in predicting sexual well-being in partnered older adults (≥55 years old). METHODS A total of 111 participants (mean [SD], 63.2 [5.96]) completed a self-report questionnaire assessing biopsychosocial dimensions. Bivariate correlational analyses and hierarchical multiple regression were conducted to investigate factors associated with sexual well-being. Health-related factors were entered into the first regression model. The second model included factors pertaining to relationship dimensions. Sexual beliefs were introduced in the third regression model. OUTCOMES Self-rated health, psychological distress, subjective cognitive decline, sexual beliefs, duration of the relationship, relationship satisfaction, and sexual well-being were assessed. RESULTS Findings from the hierarchical regression revealed that duration of relationship [t(104) = -3.07, P < .01], relationship satisfaction [t(104) = 8.49, P < .001], and age-related sexual beliefs [t(104) = -2.75, P < .01] were significant predictors of sexual well-being of partnered older adults [F(6, 104) = 22.77, P < .001, R2 = .57], after controlling for health-related factors. These findings suggest that relationship factors and sexual beliefs play a significant role in predicting sexual well-being of older adults, above and beyond health-related dimensions. CLINICAL IMPLICATIONS Interventional approaches aimed at promoting sexual well-being in older age might benefit from incorporating exercises that demystify age-related sexual beliefs, by normalizing changes that occur with aging and fostering positive attitudes toward sexual expression in older age; particularly for older adults in long-term relationships, relationship satisfaction must also be considered as an important intervention target. STRENGTHS AND LIMITATIONS Further investigation using longitudinal designs is required to examine the causal links between these factors and sexual well-being in older age. CONCLUSION Findings from this study underscore the role of relationship dimensions and age-related sexual beliefs for the sexual well-being of partnered older adults.
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Affiliation(s)
- Priscila A Vasconcelos
- Faculty of Psychology and Educational Sciences, University of Porto. Rua Alfredo Allen, Porto 4200-135, Portugal
| | - Constança Paúl
- Department of Behavioral Sciences, Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Porto 4050-313, Portugal
| | - Pedro J Nobre
- Faculty of Psychology and Educational Sciences, University of Porto. Rua Alfredo Allen, Porto 4200-135, Portugal
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Sadeghi MA, Nassireslami E, Yousefi Zoshk M, Hosseini Y, Abbasian K, Chamanara M. Phosphodiesterase inhibitors in psychiatric disorders. Psychopharmacology (Berl) 2023; 240:1201-1219. [PMID: 37060470 DOI: 10.1007/s00213-023-06361-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 03/27/2023] [Indexed: 04/16/2023]
Abstract
RATIONALE Challenges in drug development for psychiatric disorders have left much room for the introduction of novel treatments with better therapeutic efficacies and indices. As a result, intense research has focused on identifying new targets for developing such pharmacotherapies. One of these targets may be the phosphodiesterase (PDE) class of enzymes, which play important roles in intracellular signaling. Due to their critical roles in cellular pathways, these enzymes affect diverse neurobiological functions from learning and memory formation to neuroinflammation. OBJECTIVES In this paper, we reviewed studies on the use of PDE inhibitors (PDEIs) in preclinical models and clinical trials of psychiatric disorders including depression, anxiety, schizophrenia, post-traumatic stress disorder (PTSD), bipolar disorder (BP), sexual dysfunction, and feeding disorders. RESULTS PDEIs are able to improve symptoms of psychiatric disorders in preclinical models through activating the cAMP-PKA-CREB and cGMP-PKG pathways, attenuating neuroinflammation and oxidative stress, and stimulating neural plasticity. The most promising therapeutic candidates to emerge from these preclinical studies are PDE2 and PDE4 inhibitors for depression and anxiety and PDE1 and PDE10 inhibitors for schizophrenia. Furthermore, PDE3 and 4 inhibitors have shown promising results in clinical trials in patients with depression and schizophrenia. CONCLUSIONS Larger and better designed clinical studies of PDEIs in schizophrenia, depression, and anxiety are warranted to facilitate their translation into the clinic. Regarding the other conditions discussed in this review (most notably PTSD and BP), better characterization of the effects of PDEIs in preclinical models is required before clinical studies.
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Affiliation(s)
- Mohammad Amin Sadeghi
- Toxicology Research Center, AJA University of Medical Sciences, Tehran, Iran
- Department of Pharmacology, School of Medicine, AJA University of Medical Sciences, Tehran, Iran
| | - Ehsan Nassireslami
- Toxicology Research Center, AJA University of Medical Sciences, Tehran, Iran
- Department of Pharmacology, School of Medicine, AJA University of Medical Sciences, Tehran, Iran
| | - Mojtaba Yousefi Zoshk
- Trauma Research Center, AJA University of Medical Sciences, Tehran, Iran
- Department of Pediatrics, AJA University of Medical Sciences, Tehran, Iran
| | - Yasaman Hosseini
- Cognitive Neuroscience Center, School of Medicine, AJA University of Medical Sciences, Tehran, Iran
| | - Kourosh Abbasian
- Management and Health Economics Department, AJA University of Medical Sciences, Tehran, Iran
| | - Mohsen Chamanara
- Toxicology Research Center, AJA University of Medical Sciences, Tehran, Iran.
- Department of Pharmacology, School of Medicine, AJA University of Medical Sciences, Tehran, Iran.
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Phosphodiesterase inhibitor and selective serotonin reuptake inhibitor combination therapy versus monotherapy for the treatment of major depressive disorder: a systematic review and meta-analysis. Int Clin Psychopharmacol 2023:00004850-990000000-00045. [PMID: 36752703 DOI: 10.1097/yic.0000000000000457] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
OBJECTIVE Selective serotonin reuptakeinhibitors (SSRIs) are the gold standard treatment for major depressive disorder (MDD). However, the use of phosphodiesterase (PDE) inhibitors in the treatment of MDD remains unclear. Our study aims to compare the effect of PDE inhibitor combination therapy to SSRI monotherapy for the treatment of MDD. METHODS We performed a comprehensive literature search using PubMed, EMBASE, and Web of Science databases, for studies that assess the impact of PDE inhibitor therapy on MDD patients. The primary outcome of our study was treatment response rate at the end of study time. Pooled odds ratio (OR) and corresponding 95% confidence intervals (CIs) were calculated using the random-effects model. A P-value <0.05 was considered statistically significant. RESULTS A total of four randomized control trials (RCTs), including 270 patients with MDD, were included in the analysis. Follow-up periods ranged from 6 to 12 weeks. The PDE inhibitor group was associated with a significantly higher treatment response rate (OR, 4.77; 95% CI, 2.05-11.12; P = 0.0003). CONCLUSION Our meta-analysis demonstrated that MDD patients receiving PDE inhibitor combination therapy had a higher treatment response rate than MDD patients receiving SSRI monotherapy. Further large-scale RCTs with long-term follow-ups are necessary to validate our findings.
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Tropea MR, Gulisano W, Vacanti V, Arancio O, Puzzo D, Palmeri A. Nitric oxide/cGMP/CREB pathway and amyloid-beta crosstalk: From physiology to Alzheimer's disease. Free Radic Biol Med 2022; 193:657-668. [PMID: 36400326 DOI: 10.1016/j.freeradbiomed.2022.11.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/30/2022] [Accepted: 11/12/2022] [Indexed: 11/17/2022]
Abstract
The nitric oxide (NO)/cGMP pathway has been extensively studied for its pivotal role in synaptic plasticity and memory processes, resulting in an increase of cAMP response element-binding (CREB) phosphorylation, and consequent synthesis of plasticity-related proteins. The NO/cGMP/CREB signaling is downregulated during aging and neurodegenerative disorders and is affected by Amyloid-β peptide (Aβ) and tau protein, whose increase and deposition is considered the key pathogenic event of Alzheimer's disease (AD). On the other hand, in physiological conditions, the crosstalk between the NO/cGMP/PKG/CREB pathway and Aβ ensures long-term potentiation and memory formation. This review summarizes the current knowledge on the interaction between the NO/cGMP/PKG/CREB pathway and Aβ in the healthy and diseased brain, offering a new perspective to shed light on AD pathophysiology. We will focus on the synaptic mechanisms underlying Aβ physiological interplay with cGMP pathway and how this balance is corrupted in AD, as high levels of Aβ interfere with NO production and cGMP molecular signaling leading to cognitive impairment. Finally, we will discuss results from preclinical and clinical studies proposing the increase of cGMP signaling as a therapeutic strategy in the treatment of AD.
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Affiliation(s)
- Maria Rosaria Tropea
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, 95123, Italy
| | - Walter Gulisano
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, 95123, Italy
| | - Valeria Vacanti
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, 95123, Italy
| | - Ottavio Arancio
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, USA; Department of Pathology & Cell Biology and Department of Medicine, Columbia University, New York, NY, 10032, USA
| | - Daniela Puzzo
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, 95123, Italy; Oasi Research Institute-IRCCS, Troina (EN), 94018, Italy.
| | - Agostino Palmeri
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, 95123, Italy
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Jyoti Dutta B, Singh S, Seksaria S, Das Gupta G, Bodakhe SH, Singh A. Potential role of IP3/Ca 2+ signaling and phosphodiesterases: Relevance to neurodegeneration in Alzheimer's disease and possible therapeutic strategies. Biochem Pharmacol 2022; 201:115071. [PMID: 35525328 DOI: 10.1016/j.bcp.2022.115071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 11/02/2022]
Abstract
Despite large investments by industry and governments, no disease-modifying medications for the treatment of patients with Alzheimer's disease (AD) have been found. The failures of various clinical trials indicate the need for a more in-depth understanding of the pathophysiology of AD and for innovative therapeutic strategies for its treatment. Here, we review the rational for targeting IP3 signaling, cytosolic calcium dysregulation, phosphodiesterases (PDEs), and secondary messengers like cGMP and cAMP, as well as their correlations with the pathophysiology of AD. Various drugs targeting these signaling cascades are still in pre-clinical and clinical trials which support the ideas presented in this article. Further, we describe different molecular mechanisms and medications currently being used in various pre-clinical and clinical trials involving IP3/Ca+2 signaling. We also highlight various isoforms, as well as the functions and pharmacology of the PDEs broadly expressed in different parts of the brain and attempt to unravel the potential benefits of PDE inhibitors for use as novel medications to alleviate the pathogenesis of AD.
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Affiliation(s)
- Bhaskar Jyoti Dutta
- Department of Pharmacology, ISF College of Pharmacy, GT Road, Ghal Kalan, Moga-142001, Punjab, India
| | - Shamsher Singh
- Department of Pharmacology, ISF College of Pharmacy, GT Road, Ghal Kalan, Moga-142001, Punjab, India
| | - Sanket Seksaria
- Department of Pharmacology, ISF College of Pharmacy, GT Road, Ghal Kalan, Moga-142001, Punjab, India
| | - Ghanshyam Das Gupta
- Department of Pharmacology, ISF College of Pharmacy, GT Road, Ghal Kalan, Moga-142001, Punjab, India
| | - Surendra H Bodakhe
- Department of Pharmacy, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur - 495009, Chhattisgarh, India
| | - Amrita Singh
- Department of Pharmacology, ISF College of Pharmacy, GT Road, Ghal Kalan, Moga-142001, Punjab, India.
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Manalo TA, Biermann HD, Patil DH, Mehta A. The Temporal Association of Depression and Anxiety in Young Men With Erectile Dysfunction. J Sex Med 2022; 19:201-206. [PMID: 34969613 DOI: 10.1016/j.jsxm.2021.11.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 11/17/2021] [Accepted: 11/22/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Erectile dysfunction (ED) is a multidimensional sexual disorder that is being increasingly diagnosed in younger men. Although mental illnesses such as depression and anxiety are known risk factors for ED, the association between these conditions and ED has been understudied in young men. AIM To explore the temporal association between depression, anxiety, and ED in a population-based cohort of young men. METHODS Using 2009-2018 MarketScan Commercial Claims data, we identified all men with ED aged 18-40 years (cases). Using ICD-9/-10 codes and prescription data, we evaluated the prevalence and incidence of depression and anxiety in this cohort. Cases were matched with men without a diagnosis of ED (controls) based on age, Charlson Comorbidity Index, history of hypertension, geographic region, and year of presentation. We examined the prevalence of depression and anxiety within 12 months prior to ED diagnosis and incidence of depression and anxiety up to 36 months after ED diagnosis in cases vs controls. Differences between cases and controls were tested with Wilcoxon rank-sum test for numerical covariates, and chi-square test for categorical covariates. Significance was set at P < .05. OUTCOMES Prevalence and incidence of depression and anxiety in young men with and without ED. RESULTS Within the 12-month period preceding ED diagnosis, the prevalence of depression and anxiety in cases vs controls were 17.1% vs 12.9%, respectively (P < .001). The incidence of depression and anxiety were higher amongst cases vs controls at 12- (11.7% vs 6.3%), 24- (14.5% vs 9.0%,) and 36- (15.9% vs 10.6%) months following ED diagnosis (P < .001). CLINICAL IMPLICATIONS High incidence and prevalence of depression and anxiety in young men diagnosed with ED highlight the importance of normalizing mental health screenings and routine psychiatric follow-up in this population. STRENGTHS & LIMITATIONS Our contemporary, case-control study utilizes a population-based cohort of young men with ED to study the temporal association between depression, anxiety, and ED, which is understudied to date. The MarketScan commercial claims database used in this analysis includes men covered by private insurers only and lacks data on symptoms and treatments. CONCLUSION Young men with ED had significantly higher rates of depression and anxiety both before and after ED diagnosis in comparison to young men without ED. Manalo TA, Biermann HD, Patil DH, et al. The Temporal Association of Depression and Anxiety in Young Men With Erectile Dysfunction. J Sex Med 2022;19:201-206.
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Affiliation(s)
- Tad A Manalo
- Department of Urology, Emory University School of Medicine, Atlanta, GA, USA
| | - Henry D Biermann
- Department of Urology, Emory University School of Medicine, Atlanta, GA, USA
| | - Dattatraya H Patil
- Department of Urology, Emory University School of Medicine, Atlanta, GA, USA
| | - Akanksha Mehta
- Department of Urology, Emory University School of Medicine, Atlanta, GA, USA.
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Taoro-González L, Cabrera-Pastor A, Sancho-Alonso M, Felipo V. Intracellular and extracelluar cyclic GMP in the brain and the hippocampus. VITAMINS AND HORMONES 2022; 118:247-288. [PMID: 35180929 DOI: 10.1016/bs.vh.2021.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Cyclic Guanosine-Monophosphate (cGMP) is implicated as second messenger in a plethora of pathways and its effects are executed mainly by cGMP-dependent protein kinases (PKG). It is involved in both peripheral (cardiovascular regulation, intestinal secretion, phototransduction, etc.) and brain (hippocampal synaptic plasticity, neuroinflammation, cognitive function, etc.) processes. Stimulation of hippocampal cGMP signaling have been proved to be beneficial in animal models of aging, Alzheimer's disease or hepatic encephalopathy, restoring different cognitive functions such as passive avoidance, object recognition or spatial memory. However, even when some inhibitors of cGMP-degrading enzymes (PDEs) are already used against peripheral pathologies, their utility as neurological treatments is still under clinical investigation. Additionally, it has been demonstrated a list of cGMP roles as not second but first messenger. The role of extracellular cGMP has been specially studied in hippocampal function and cognitive impairment in animal models and it has emerged as an important modulator of neuroinflammation-mediated cognitive alterations and hippocampal synaptic plasticity malfunction. Specifically, it has been demonstrated that extracellular cGMP decreases hippocampal IL-1β levels restoring membrane expression of glutamate receptors in the hippocampus and cognitive function in hyperammonemic rats. The mechanisms implicated are still unclear and might involve complex interactions between hippocampal neurons, astrocytes and microglia. Membrane targets for extracellular cGMP are still poorly understood and must be addressed in future studies.
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Affiliation(s)
- Lucas Taoro-González
- Department of Clinical Psychology, Psychobiology and Methodology, Area of Psycobiology, University of La Laguna, Tenerife, Spain
| | - Andrea Cabrera-Pastor
- Fundación Investigación Hospital Clínico, Instituto de Investigación Sanitaria (INCLIVA), Valencia, Spain; Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - María Sancho-Alonso
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Vicente Felipo
- Laboratory of Neurobiology, Centro de Investigación Príncipe Felipe, Valencia, Spain.
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Jagdish RK, Kamaal A, Shasthry SM, Benjamin J, Maiwall R, Jindal A, Choudhary A, Rajan V, Arora V, Bhardwaj A, Kumar G, Kumar M, Sarin SK. Tadalafil improves erectile dysfunction and quality of life in men with cirrhosis: a randomized double blind placebo controlled trial. Hepatol Int 2021; 17:434-451. [PMID: 34775577 DOI: 10.1007/s12072-021-10264-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 10/20/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND AIMS Patients with cirrhosis have high prevalence of erectile dysfunction (ED). The aim of this study was to study the efficacy and safety of tadalafil for ED in patients with cirrhosis. METHODS 140 cirrhotic males with ED were randomized into tadalafil 10 mg daily (n = 70) or placebo (n = 70) for 12 weeks. ED was diagnosed if erectile function (EF) domain score was < 25 in International Index of Erectile Function (IIEF) questionnaire. The erectile function domain consists of six questions concerning erection frequency, erection firmness, frequency of partner penetration, frequency of maintaining erection after penetration, ability to maintain erection to completion of intercourse and confidence in achieving and maintaining erection. Primary outcome was proportion of patients having an increase in > 5 points in EF domain of the IIEF. Generalized Anxiety Disorder 7 (GAD-7) questionnaire was used for screening and severity measuring of GAD. The presence of depression was screened using the Patient Health Questionnaire (PHQ-9) and the assessment of health related quality of life was done using the Short Form (36) Health Survey. RESULTS At the end of 12 weeks, more patients in tadalafil group achieved > 5 points increase in the EF domain of the IIEF when compared with the placebo group [44(62.9%) vs. 21(30%), p < 0.001]. At the end of 12 weeks, patients receiving tadalafil had significantly more change in scores on the erectile function domain, orgasmic function domain, intercourse satisfaction domain, overall satisfaction domain, erection vaginal penetration rates and successful intercourse; significantly more decline in the GAD-7 and PHQ-9 scores; significantly more improvement in scores of five of the eight domains of SF-36 (general health perception, vitality score, social functioning, role emotional and mental health) and the mental component summary rates when compared with placebo. The development of side effects and the changes in HVPG were not significantly different between the two groups. CONCLUSIONS Tadalafil therapy may enhance erectile function, improve anxiety, depression and quality of life; and is well tolerated by men with cirrhosis (CTP score < 10) and ED. However, further larger and long-term studies are needed to confirm these results and look for rarer side effects of using tadalafil in patients with cirrhosis. TRIAL REGISTRATION ClinicalTrials.gov identifier number NCT03566914; first posted date: June 25, 2018.
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Affiliation(s)
- Rakesh Kumar Jagdish
- Department of Hepatology and Liver Transplantation, Institute of Liver and Biliary Sciences, D1 Vasant Kunj, New Delhi, 110070, India
| | - Ahmed Kamaal
- Department of Urology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Saggere Muralikrishna Shasthry
- Department of Hepatology and Liver Transplantation, Institute of Liver and Biliary Sciences, D1 Vasant Kunj, New Delhi, 110070, India
| | - Jaya Benjamin
- Department of Clinical Nutrition, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Rakhi Maiwall
- Department of Hepatology and Liver Transplantation, Institute of Liver and Biliary Sciences, D1 Vasant Kunj, New Delhi, 110070, India
| | - Ankur Jindal
- Department of Hepatology and Liver Transplantation, Institute of Liver and Biliary Sciences, D1 Vasant Kunj, New Delhi, 110070, India
| | - Ashok Choudhary
- Department of Hepatology and Liver Transplantation, Institute of Liver and Biliary Sciences, D1 Vasant Kunj, New Delhi, 110070, India
| | - Vijayaraghavan Rajan
- Department of Hepatology and Liver Transplantation, Institute of Liver and Biliary Sciences, D1 Vasant Kunj, New Delhi, 110070, India
| | - Vinod Arora
- Department of Hepatology and Liver Transplantation, Institute of Liver and Biliary Sciences, D1 Vasant Kunj, New Delhi, 110070, India
| | - Ankit Bhardwaj
- Department of Clinical Research, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Guresh Kumar
- Department of Biostatistics, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Manoj Kumar
- Department of Hepatology and Liver Transplantation, Institute of Liver and Biliary Sciences, D1 Vasant Kunj, New Delhi, 110070, India.
| | - Shiv K Sarin
- Department of Hepatology and Liver Transplantation, Institute of Liver and Biliary Sciences, D1 Vasant Kunj, New Delhi, 110070, India
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Sabaner MC, Dogan M, Akdogan M, Karadag S, Onur IU, Tasci Aİ, Yigit FU. Evaluation of Retinal and Choroidal Microcirculation Alterations After a Single Dose of Oral 5-mg Tadalafil: A Prospective Pilot Optical Coherence Tomography Angiography Study. J Ocul Pharmacol Ther 2021; 37:421-429. [PMID: 34143665 DOI: 10.1089/jop.2020.0124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Purpose: To evaluate the effects of a single dose of oral 5-mg tadalafil on macular microcirculation as measured using optical coherence tomography (OCT) and angiography (OCTA) in healthy volunteers. Methods: Twenty-two healthy, middle-aged, sexually active, and male health care worker volunteers were included in this prospective study. All volunteers have a history of occasionally using off-label 5 mg tadalafil to enhance sexual performance. Superficial and deep capillary plexus vascular densities, foveal avascular zone parameters, outer retina, and choriocapillaris flow areas were performed using the OCTA, and subfoveal-choroidal thickness (CT) was performed by using the OCT. Measurements were performed preintake, 30 min, 1, 4, 24 h, 2, 3, 4, and 7 days after the intake of tadalafil off-label. Results: Twenty-two eyes of 22 male volunteers were included in the study. The mean age was 37.16 ± 4.52 years. At 30 min, 1 h, and 4 h after intake, a statistically significant increase was observed in the choriocapillaris flow area and CT compared with preintake (Friedman test, P = 0.034 and P < 0.001, respectively). Conclusion: This study showed that a single dose of oral 5-mg tadalafil causes an increase in choriocapillaris flow and CT. To evaluate the effects of tadalafil on the retina and choroid, an OCTA assessment may be helpful.
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Affiliation(s)
| | - Mustafa Dogan
- Department of Ophthalmology, Faculty of Medicine, Afyonkarahisar Health Sciences University, Afyonkarahisar, Turkey
| | - Muberra Akdogan
- Department of Ophthalmology, Faculty of Medicine, Afyonkarahisar Health Sciences University, Afyonkarahisar, Turkey
| | - Serdar Karadag
- Department of Urology, Bakirkoy Sadi Konuk Training and Research Hospital, Istanbul, Turkey
| | - Ismail Umut Onur
- Department of Ophthalmology, Bakirkoy Sadi Konuk Training and Research Hospital, Istanbul, Turkey
| | - Ali İhsan Tasci
- Department of Urology, Bakirkoy Sadi Konuk Training and Research Hospital, Istanbul, Turkey
| | - Fadime Ulviye Yigit
- Department of Ophthalmology, Bakirkoy Sadi Konuk Training and Research Hospital, Istanbul, Turkey
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Duarte-Silva E, Meiry da Rocha Araújo S, Oliveira WH, Lós DB, Bonfanti AP, Peron G, de Lima Thomaz L, Verinaud L, Peixoto CA. Sildenafil Alleviates Murine Experimental Autoimmune Encephalomyelitis by Triggering Autophagy in the Spinal Cord. Front Immunol 2021; 12:671511. [PMID: 34054847 PMCID: PMC8156813 DOI: 10.3389/fimmu.2021.671511] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 04/19/2021] [Indexed: 12/15/2022] Open
Abstract
Multiple Sclerosis (MS) is a neuroinflammatory and chronic Central Nervous System (CNS) disease that affects millions of people worldwide. The search for more promising drugs for the treatment of MS has led to studies on Sildenafil, a phosphodiesterase type 5 Inhibitor (PDE5I) that has been shown to possess neuroprotective effects in the Experimental Autoimmune Encephalomyelitis (EAE), an animal model of MS. We have previously shown that Sildenafil improves the clinical score of EAE mice via modulation of apoptotic pathways, but other signaling pathways were not previously covered. Therefore, the aim of the present study was to further investigate the effects of Sildenafil treatment on autophagy and nitrosative stress signaling pathways in EAE. 24 female C57BL/6 mice were divided into the following groups: (A) Control - received only water; (B) EAE - EAE untreated mice; (C) SILD - EAE mice treated with 25mg/kg of Sildenafil s.c. The results showed that EAE mice presented a pro-nitrosative profile characterized by high tissue nitrite levels, lowered levels of p-eNOS and high levels of iNOS. Furthermore, decreased levels of LC3, beclin-1 and ATG5, suggests impaired autophagy, and decreased levels of AMPK in the spinal cord were also detected in EAE mice. Surprisingly, treatment with Sildenafil inhibited nitrosative stress and augmented the levels of LC3, beclin-1, ATG5, p-CREB and BDNF and decreased mTOR levels, as well as augmented p-AMPK. In conclusion, we propose that Sildenafil alleviates EAE by activating autophagy via the eNOS-NO-AMPK-mTOR-LC3-beclin1-ATG5 and eNOS-NO-AMPK-mTOR-CREB-BDNF pathways in the spinal cord.
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Affiliation(s)
- Eduardo Duarte-Silva
- Laboratory of Ultrastructure, Aggeu Magalhães Institute (IAM), Recife, Brazil
- Postgraduate Program in Biosciences and Biotechnology for Health (PPGBBS), Oswaldo Cruz Foundation (FIOCRUZ-PE)/Aggeu Magalhães Institute (IAM), Recife, Brazil
- Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Recife, Brazil
| | - Shyrlene Meiry da Rocha Araújo
- Laboratory of Ultrastructure, Aggeu Magalhães Institute (IAM), Recife, Brazil
- Postgraduate Program in Biological Sciences/Center of Biosciences, Federal University of Pernambuco (UFPE), Recife, Brazil
| | - Wilma Helena Oliveira
- Laboratory of Ultrastructure, Aggeu Magalhães Institute (IAM), Recife, Brazil
- Postgraduate Program in Biological Sciences/Center of Biosciences, Federal University of Pernambuco (UFPE), Recife, Brazil
| | - Deniele Bezerra Lós
- Postgraduate Program in Biotechnology/Northeast Network in Biotechnology (RENORBIO), Federal University of Pernambuco (UFPE), Recife, Brazil
| | - Amanda Pires Bonfanti
- Department of Structural and Functional Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Gabriela Peron
- Department of Structural and Functional Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Livia de Lima Thomaz
- Department of Structural and Functional Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Liana Verinaud
- Department of Structural and Functional Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Christina Alves Peixoto
- Laboratory of Ultrastructure, Aggeu Magalhães Institute (IAM), Recife, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
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Memory Enhancers for Alzheimer's Dementia: Focus on cGMP. Pharmaceuticals (Basel) 2021; 14:ph14010061. [PMID: 33451088 PMCID: PMC7828493 DOI: 10.3390/ph14010061] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 01/07/2021] [Accepted: 01/12/2021] [Indexed: 02/06/2023] Open
Abstract
Cyclic guanosine-3',5'-monophosphate, better known as cyclic-GMP or cGMP, is a classical second messenger involved in a variety of intracellular pathways ultimately controlling different physiological functions. The family of guanylyl cyclases that includes soluble and particulate enzymes, each of which comprises several isoforms with different mechanisms of activation, synthesizes cGMP. cGMP signaling is mainly executed by the activation of protein kinase G and cyclic nucleotide gated channels, whereas it is terminated by its hydrolysis to GMP operated by both specific and dual-substrate phosphodiesterases. In the central nervous system, cGMP has attracted the attention of neuroscientists especially for its key role in the synaptic plasticity phenomenon of long-term potentiation that is instrumental to memory formation and consolidation, thus setting off a "gold rush" for new drugs that could be effective for the treatment of cognitive deficits. In this article, we summarize the state of the art on the neurochemistry of the cGMP system and then review the pre-clinical and clinical evidence on the use of cGMP enhancers in Alzheimer's disease (AD) therapy. Although preclinical data demonstrates the beneficial effects of cGMP on cognitive deficits in AD animal models, the results of the clinical studies carried out to date are not conclusive. More trials with a dose-finding design on selected AD patient's cohorts, possibly investigating also combination therapies, are still needed to evaluate the clinical potential of cGMP enhancers.
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Mathur R, Parmar A, Rajpurohit SS, Tundup T, Bhad R, Rao R. Sildenafil Misuse for its Psychoactive Properties? A Case Report. J Addict Med 2020; 15:522-524. [PMID: 33369975 DOI: 10.1097/adm.0000000000000805] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Sildenafil is a widely used drug for the treatment of erectile dysfunction in a dosage ranging from 50 to 100 mg per day. Recreational use is reported among youth for its sexual function enhancing effects. To date, however, no study has reported the use of sildenafil for its nonsexual, psychoactive effects. We report a case of a 38-year-old male with opioid and sedative use disorder who self-administered sildenafil orally in a dose of up to 2000 mg per day for its psychoactive effects (primarily) for 10 years before seeking treatment and discuss the literature relevant to the case.
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Affiliation(s)
- Rahul Mathur
- National Drug Dependence Treatment Centre and Department of Psychiatry, All India Institute of Medical Sciences, New Delhi - 29, India (RM, SS, TT, RB, RR); Department of Psychiatry and Drug De-addiction and Treatment Center, All India Institute of Medical Sciences, Bhubaneswar, India (AP)
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Stridh A, Pontén M, Arver S, Kirsch I, Abé C, Jensen KB. Placebo Responses Among Men With Erectile Dysfunction Enrolled in Phosphodiesterase 5 Inhibitor Trials: A Systematic Review and Meta-analysis. JAMA Netw Open 2020; 3:e201423. [PMID: 32196105 PMCID: PMC7084170 DOI: 10.1001/jamanetworkopen.2020.1423] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
IMPORTANCE Placebo responses in the treatment of erectile dysfunction (ED) are poorly described in the literature to date. OBJECTIVE To quantify the association of placebo with ED outcomes among men enrolled in placebo-controlled, phosphodiesterase 5 inhibitor (PDE5I) trials. DATA SOURCES For this systematic review and meta-analysis, a database search was conducted to identify double-blind, placebo-controlled studies using PDE5Is for the treatment of ED published from January 1, 1998, to December 31, 2018, within MEDLINE, Embase, Cochrane Library, and Web of Science. Only articles published in the English language were included. STUDY SELECTION Double-blind, placebo-controlled randomized clinical trials of PDE5Is for ED were included. Studies were excluded if they did not provide distribution measures for statistical analysis. Study selection review assessments were conducted by 2 independent investigators. A total of 2215 studies were identified from the database search, and after review, 63 studies that included 12 564 men were analyzed. DATA EXTRACTION AND SYNTHESIS Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed in abstracting data and assessing validity. Data were extracted from published reports by 2 independent reviewers. Quality assessment was performed using the Jadad scale. Data were pooled using a random-effects model. MAIN OUTCOMES AND MEASURES The main outcome was improvement in the erectile function domain of the International Index of Erectile Function questionnaire in the placebo arm of the included studies. Effect size was reported as bias-corrected standardized mean difference (Hedges g). The hypothesis was formulated before data extraction. RESULTS A total of 63 studies that included 12 564 men (mean [SD] age, 55 [7] years; age range, 36-68 years) were included. Erectile function was significantly improved among participants in the placebo arm, with a small to moderate effect size (Hedges g [SE], 0.35 [0.03]; P < .001). Placebo effect size was larger among participants with ED associated with posttraumatic stress disorder (Hedges g [SE], 0.78 [0.32]; P = .02) compared with the overall analysis. No significant difference was found between placebo and PDE5Is for ED after prostate surgery or radiotherapy (Hedges g [SE], 0.30 [0.17]; P = .08). CONCLUSIONS AND RELEVANCE In this study, placebo was associated with improvement of ED, especially among men with ED-related posttraumatic stress disorder. No difference was found between placebo and PDE5I among men treated for ED after prostate surgery.
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Affiliation(s)
- Alexander Stridh
- Department of Clinical Neuroscience, Karolinska Institute, Solna, Sweden
| | - Moa Pontén
- Department of Clinical Neuroscience, Karolinska Institute, Solna, Sweden
| | - Stefan Arver
- Department of Medicine, Karolinska Institute, Solna, Sweden
| | - Irving Kirsch
- Program in Placebo Studies, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Christoph Abé
- Department of Clinical Neuroscience, Karolinska Institute, Solna, Sweden
| | - Karin B. Jensen
- Department of Clinical Neuroscience, Karolinska Institute, Solna, Sweden
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Duarte-Silva E, Filho AJMC, Barichello T, Quevedo J, Macedo D, Peixoto C. Phosphodiesterase-5 inhibitors: Shedding new light on the darkness of depression? J Affect Disord 2020; 264:138-149. [PMID: 32056743 DOI: 10.1016/j.jad.2019.11.114] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 11/22/2019] [Accepted: 11/26/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND Phosphodiesterase-5 inhibitors (PDE5Is) are used to treat erectile dysfunction (ED). Recently, the antidepressant-like effect of PDE5Is was demonstrated in animal models of depression. In clinical settings, PDE5Is were studied only for ED associated depression. Hence, there are no studies evaluating the effects of PDE5Is for the treatment of major depressive disorder (MDD) without ED. In this review article, we aimed to discuss the use of PDE5Is in the context of MDD, highlighting the roles of PDE genes in the development of MDD, the potential mechanisms by which PDE5Is can be beneficial for MDD and the potentials and limitations of PDE5Is repurposing to treat MDD. METHODS We used PubMed (MEDLINE) database to collect the studies cited in this review. Papers written in English language regardless the year of publication were selected. RESULTS A few preclinical studies support the antidepressant-like activity of PDE5Is. Clinical studies in men with ED and depression suggest that PDE5Is improve depressive symptoms. No clinical studies were conducted in subjects suffering from depression without ED. Antidepressant effect of PDE5Is may be explained by multiple mechanisms including inhibition of brain inflammation and modulation of neuroplasticity. LIMITATIONS The low number of preclinical and absence of clinical studies to support the antidepressant effect of PDE5Is. CONCLUSIONS No clinical trial was conducted to date evaluating PDE5Is in depressed patients without ED. PDE5Is' anti-inflammatory and neuroplasticity mechanisms may justify the potential antidepressant effect of these drugs. Despite this, clinical trials evaluating their efficacy in depressed patients need to be conducted.
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Affiliation(s)
- Eduardo Duarte-Silva
- Laboratory of Ultrastructure, Aggeu Magalhães Institute (IAM), Oswaldo Cruz Foundation (FIOCRUZ-PE), Recife, PE, Brazil; Graduate Program in Biosciences and Biotechnology for Health (PPGBBS), Aggeu Magalhães Institute (IAM), Recife, PE, Brazil.
| | - Adriano José Maia Chaves Filho
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Tatiana Barichello
- Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, 1941 East Road, Houston, TX 77054, United States; Laboratory of Neurosciences, Graduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina-UNESC, Criciúma, SC, Brazil; Center of Excellence on Mood Disorders, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States.
| | - João Quevedo
- Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, 1941 East Road, Houston, TX 77054, United States; Laboratory of Neurosciences, Graduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina-UNESC, Criciúma, SC, Brazil; Center of Excellence on Mood Disorders, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States.
| | - Danielle Macedo
- Neuropsychopharmacology Laboratory, Drug Research and Development Center, Faculty of Medicine, Universidade Federal do Ceará, Fortaleza, CE, Brazil; Department of Physiology and Pharmacology, Faculty of Medicine, Universidade Federal do Ceará, Fortaleza, CE, Brazil; National Institute for Translational Medicine (INCT-TM, CNPq), Ribeirão Preto, Brazil
| | - Christina Peixoto
- Laboratory of Ultrastructure, Aggeu Magalhães Institute (IAM), Oswaldo Cruz Foundation (FIOCRUZ-PE), Recife, PE, Brazil; National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
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Caudano F, Montalto G, Passalacqua M, Pronzato MA, Fedele E, Ricciarelli R. cGMP favors the interaction between APP and BACE1 by inhibiting Rab5 GTPase activity. Sci Rep 2020; 10:1358. [PMID: 31992816 PMCID: PMC6987147 DOI: 10.1038/s41598-020-58476-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 01/13/2020] [Indexed: 11/12/2022] Open
Abstract
We previously demonstrated that cyclic guanosine monophosphate (cGMP) stimulates amyloid precursor protein (APP) and beta-secretase (BACE1) approximation in neuronal endo-lysosomal compartments, thus boosting the production of amyloid-β (Aβ) peptides and enhancing synaptic plasticity and memory. Here, we further investigated the mechanism by which cGMP regulates the subcellular localization of APP and BACE1, finding that the cyclic nucleotide inhibits the activity of Rab5, a small GTPase associated with the plasma membrane and early endosomes. Accordingly, we also found that expression of a dominant-negative Rab5 mutant increases both APP-BACE1 approximation and Aβ extracellular levels, therefore mimicking the effects induced by cGMP. These results reveal a functional correlation between the cGMP/Aβ pathway and the activity of Rab5 that may contribute to the understanding of Alzheimer’s disease pathophysiology.
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Affiliation(s)
- Francesca Caudano
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Giulia Montalto
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Mario Passalacqua
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Maria A Pronzato
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Ernesto Fedele
- Department of Pharmacy and Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Roberta Ricciarelli
- Department of Experimental Medicine, University of Genoa, Genoa, Italy. .,IRCCS Ospedale Policlinico San Martino, Genoa, Italy.
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Zuccarello E, Acquarone E, Calcagno E, Argyrousi EK, Deng SX, Landry DW, Arancio O, Fiorito J. Development of novel phosphodiesterase 5 inhibitors for the therapy of Alzheimer's disease. Biochem Pharmacol 2020; 176:113818. [PMID: 31978378 DOI: 10.1016/j.bcp.2020.113818] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 01/14/2020] [Indexed: 12/13/2022]
Abstract
Nitric oxide (NO) is a gaseous molecule that plays a multifactorial role in several cellular processes. In the central nervous system, the NO dual nature in neuroprotection and neurotoxicity has been explored to unveil its involvement in Alzheimer's disease (AD). A growing body of research shows that the activation of the NO signaling pathway leading to the phosphorylation of the transcription factor cyclic adenine monophosphate responsive element binding protein (CREB) (so-called NO/cGMP/PKG/CREB signaling pathway) ameliorates altered neuroplasticity and memory deficits in AD animal models. In addition to NO donors, several other pharmacological agents, such as phosphodiesterase 5 (PDE5) inhibitors have been used to activate the pathway and rescue memory disorders. PDE5 inhibitors, including sildenafil, tadalafil and vardenafil, are marketed for the treatment of erectile dysfunction and arterial pulmonary hypertension due to their vasodilatory properties. The ability of PDE5 inhibitors to interfere with the NO/cGMP/PKG/CREB signaling pathway by increasing the levels of cGMP has prompted the hypothesis that PDE5 inhibition might be used as an effective therapeutic strategy for the treatment of AD. To this end, newly designed PDE5 inhibitors belonging to different chemical classes with improved pharmacologic profile (e.g. higher potency, improved selectivity, and blood-brain barrier penetration) have been synthesized and evaluated in several animal models of AD. In addition, recent medicinal chemistry effort has led to the development of agents concurrently acting on the PDE5 enzyme and a second target involved in AD. Both marketed and investigational PDE5 inhibitors have shown to reverse cognitive defects in young and aged wild type mice as well as transgenic mouse models of AD and tauopathy using a variety of behavioral tasks. These studies confirmed the therapeutic potential of PDE5 inhibitors as cognitive enhancers. However, clinical studies assessing cognitive functions using marketed PDE5 inhibitors have not been conclusive. Drug discovery efforts by our group and others are currently directed towards the development of novel PDE5 inhibitors tailored to AD with improved pharmacodynamic and pharmacokinetic properties. In summary, the present perspective reports an overview of the correlation between the NO signaling and AD, as well as an outline of the PDE5 inhibitors used as an alternative approach in altering the NO pathway leading to an improvement of learning and memory. The last two sections describe the preclinical and clinical evaluation of PDE5 inhibitors for the treatment of AD, providing a comprehensive analysis of the current status of the AD drug discovery efforts involving PDE5 as a new therapeutic target.
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Affiliation(s)
- Elisa Zuccarello
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, United States
| | - Erica Acquarone
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, United States
| | - Elisa Calcagno
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, United States
| | - Elentina K Argyrousi
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, United States
| | - Shi-Xian Deng
- Department of Medicine, Columbia University, New York, NY, United States
| | - Donald W Landry
- Department of Medicine, Columbia University, New York, NY, United States
| | - Ottavio Arancio
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, United States; Department of Medicine, Columbia University, New York, NY, United States; Department of Pathology and Cell Biology, Columbia University, New York, NY, United States.
| | - Jole Fiorito
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, United States; Department of Biological and Chemical Sciences, New York Institute of Technology, Old Westbury, NY, United States.
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Choi JB, Cho KJ, Kim JC, Pae CU, Koh JS. An open-label, single-arm pilot study to evaluate the efficacy of daily low dose tadalafil on depression in patients with erectile dysfunction. Transl Androl Urol 2019; 8:501-506. [PMID: 31807426 DOI: 10.21037/tau.2019.08.24] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Background Many studies have reported not only that depression and antidepressant medications can cause erectile dysfunction (ED), but also that having ED may increase the risk of depression. We investigated the effect of a daily low dose of a phosphodiesterase (PDE) type 5 inhibitor (tadalafil, 5 mg) on depression and levels of brain-derived neurotrophic factor (BDNF) in patients with ED. Methods Ten male patients with at least a 3-month history of ED [International Index of Erectile Function (IIEF)-5 score ≤21] and depression [the Korean version of the Patient Health Questionnaire (PHQ)-9 score ≥5] were analyzed in this study. The subjects were prescribed a low dose of a PDE5 inhibitor (tadalafil 5 mg) once daily for 8 weeks. The survey questionnaires were performed using the PHQ-15 and the PHQ-9 before and after administration of 8 weeks of tadalafil. Blood samples used for measuring serum BDNF levels were taken and measured at baseline and after 8 weeks of treatment. Results The mean changes in the PHQ-9 and PHQ-15 scores were 3.60±3.27 and 2.00±2.98, respectively. Analyses of the mean changes in the PHQ-9 scores revealed that the depressive symptoms of the subjects were significantly improved after administration of eight weeks of tadalafil (P<0.05). And, there was also a statistically significant increase in the PHQ-15 scores (P<0.05). Serum levels of BDNF were higher after tadalafil treatment compared to before treatment; however, this difference was not statistically significant. Conclusions The results of this prospective, clinical study suggest that daily low dose tadalafil may have a potential role in the treatment of depression in patients with ED.
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Affiliation(s)
- Jin Bong Choi
- Department of Urology, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Kang Jun Cho
- Department of Urology, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Joon Chul Kim
- Department of Urology, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Chi-Un Pae
- Department of Psychiatry, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Jun Sung Koh
- Department of Urology, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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Blokland A, Heckman P, Vanmierlo T, Schreiber R, Paes D, Prickaerts J. Phosphodiesterase Type 4 Inhibition in CNS Diseases. Trends Pharmacol Sci 2019; 40:971-985. [DOI: 10.1016/j.tips.2019.10.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 10/15/2019] [Accepted: 10/17/2019] [Indexed: 12/17/2022]
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Urios A, Ordoño F, García-García R, Mangas-Losada A, Leone P, José Gallego J, Cabrera-Pastor A, Megías J, Fermin Ordoño J, Felipo V, Montoliu C. Tadalafil Treatment Improves Inflammation, Cognitive Function, And Mismatch Negativity Of Patients With Low Urinary Tract Symptoms And Erectile Dysfunction. Sci Rep 2019; 9:17119. [PMID: 31745217 PMCID: PMC6863868 DOI: 10.1038/s41598-019-53136-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 10/21/2019] [Indexed: 12/11/2022] Open
Abstract
Patients with Benign prostatic hyperplasia, low urinary tract symptoms, and erectile dysfunction (BPH/LUTS-ED) present chronic inflammation. We studied in patients with BPH/LUTS-ED the effect of tadalafil treatment (5 mg/day) on changes in peripheral inflammation, cognitive function, and the auditory evoked potential, “mismatch negativity” (MMN). Nine patients with BPH/LUTS-ED and 12 controls performed psychometric tests, MMN. IL-6, IL-17, IL-18, cGMP and CD4+CD28− autoreactive T-cells were measured in blood. Patients with BPH/LUTS-ED performed psychometric tests, MMN, and blood extraction at baseline and after tadalafil treatment. Patients with BPH/LUTS-ED showed increased CD4+CD28− autoreactive T-cells (p < 0.05), and higher levels of pro-inflammatory interleukins IL-6 (p < 0.001), IL-17 and IL-18 (p < 0.05), compared to controls. Patients got lower scores than controls in psychometric tests assessing mental processing speed and attention (p < 0.05), and showed lower amplitude (p < 0.01) and area (p < 0.05) of MMN wave than controls. Inflammatory, psychometric and electrophysiological parameters were normalized after tadalafil treatment. In conclusion, there is a pro-inflammatory environment in blood in patients with BPH/LUTS-ED which would induce cognitive impairment and alter MMN. Phosphodiesterase-5 inhibition with tadalafil exerts anti-inflammatory effects and ameliorates cognitive function and MMN parameters. Tadalafil could be a promising candidate for chronic treatment in other inflammatory pathologies associated with mild cognitive impairment.
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Affiliation(s)
- Amparo Urios
- Fundación Investigación Hospital Clínico Valencia, INCLIVA, Valencia, Spain
| | - Felipe Ordoño
- Servicio Urología, Hospital Arnau Vilanova, Valencia, Spain
| | - Raquel García-García
- Laboratorio de Neurobiologia, Centro Investigación Príncipe Felipe, Valencia, Spain
| | - Alba Mangas-Losada
- Fundación Investigación Hospital Clínico Valencia, INCLIVA, Valencia, Spain
| | - Paola Leone
- Laboratorio de Neurobiologia, Centro Investigación Príncipe Felipe, Valencia, Spain
| | - Juan José Gallego
- Fundación Investigación Hospital Clínico Valencia, INCLIVA, Valencia, Spain
| | | | - Javier Megías
- Departamento Patología, Facultad Medicina, Universidad Valencia, Valencia, Spain
| | - Juan Fermin Ordoño
- Servicio Neurofisiología, Hospital Arnau Vilanova, Valencia, Spain, Psychopatology and Neurophysiology Unit, Paterna Mental Health Center, CIBERSAM, Valencia, Spain
| | - Vicente Felipo
- Laboratorio de Neurobiologia, Centro Investigación Príncipe Felipe, Valencia, Spain
| | - Carmina Montoliu
- Fundación Investigación Hospital Clínico Valencia, INCLIVA, Valencia, Spain. .,Departamento Patología, Facultad Medicina, Universidad Valencia, Valencia, Spain.
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21
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Baillie GS, Tejeda GS, Kelly MP. Therapeutic targeting of 3',5'-cyclic nucleotide phosphodiesterases: inhibition and beyond. Nat Rev Drug Discov 2019; 18:770-796. [PMID: 31388135 PMCID: PMC6773486 DOI: 10.1038/s41573-019-0033-4] [Citation(s) in RCA: 181] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2019] [Indexed: 01/24/2023]
Abstract
Phosphodiesterases (PDEs), enzymes that degrade 3',5'-cyclic nucleotides, are being pursued as therapeutic targets for several diseases, including those affecting the nervous system, the cardiovascular system, fertility, immunity, cancer and metabolism. Clinical development programmes have focused exclusively on catalytic inhibition, which continues to be a strong focus of ongoing drug discovery efforts. However, emerging evidence supports novel strategies to therapeutically target PDE function, including enhancing catalytic activity, normalizing altered compartmentalization and modulating post-translational modifications, as well as the potential use of PDEs as disease biomarkers. Importantly, a more refined appreciation of the intramolecular mechanisms regulating PDE function and trafficking is emerging, making these pioneering drug discovery efforts tractable.
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Affiliation(s)
- George S Baillie
- Institute of Cardiovascular and Medical Science, University of Glasgow, Glasgow, UK
| | - Gonzalo S Tejeda
- Institute of Cardiovascular and Medical Science, University of Glasgow, Glasgow, UK
| | - Michy P Kelly
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA.
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22
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Nabavi SM, Talarek S, Listos J, Nabavi SF, Devi KP, Roberto de Oliveira M, Tewari D, Argüelles S, Mehrzadi S, Hosseinzadeh A, D'onofrio G, Orhan IE, Sureda A, Xu S, Momtaz S, Farzaei MH. Phosphodiesterase inhibitors say NO to Alzheimer's disease. Food Chem Toxicol 2019; 134:110822. [PMID: 31536753 DOI: 10.1016/j.fct.2019.110822] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 09/13/2019] [Accepted: 09/14/2019] [Indexed: 12/18/2022]
Abstract
Phosphodiesterases (PDEs) consisted of 11 subtypes (PDE1 to PDE11) and over 40 isoforms that regulate levels of cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP), the second messengers in cell functions. PDE inhibitors (PDEIs) have been attractive therapeutic targets due to their involvement in diverse medical conditions, e.g. cardiovascular diseases, autoimmune diseases, Alzheimer's disease (AD), etc. Among them; AD with a complex pathology is a progressive neurodegenerative disorder which affect mostly senile people in the world and only symptomatic treatment particularly using cholinesterase inhibitors in clinic is available at the moment for AD. Consequently, novel treatment strategies towards AD are still searched extensively. Since PDEs are broadly expressed in the brain, PDEIs are considered to modulate neurodegenerative conditions through regulating cAMP and cGMP in the brain. In this sense, several synthetic or natural molecules inhibiting various PDE subtypes such as rolipram and roflumilast (PDE4 inhibitors), vinpocetine (PDE1 inhibitor), cilostazol and milrinone (PDE3 inhibitors), sildenafil and tadalafil (PDE5 inhibitors), etc have been reported showing encouraging results for the treatment of AD. In this review, PDE superfamily will be scrutinized from the view point of structural features, isoforms, functions and pharmacology particularly attributed to PDEs as target for AD therapy.
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Affiliation(s)
- Seyed Mohammad Nabavi
- Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
| | - Sylwia Talarek
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodźki 4a St, 20-093, Lublin, Poland.
| | - Joanna Listos
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodźki 4a St, 20-093, Lublin, Poland.
| | - Seyed Fazel Nabavi
- Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
| | - Kasi Pandima Devi
- Department of Biotechnology, Alagappa University, Karaikudi, 630003, Tamil Nadu, India.
| | - Marcos Roberto de Oliveira
- Departamento de Química (DQ), Instituto de Ciências Exatas e da Terra (ICET), Universidade Federal de Mato Grosso (UFMT), Cuiabá, Brazil.
| | - Devesh Tewari
- Department of Pharmacognosy, School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, 144411, Punjab, India.
| | - Sandro Argüelles
- Department of Physiology, Faculty of Pharmacy, University of Seville, Seville, Spain.
| | - Saeed Mehrzadi
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran.
| | - Azam Hosseinzadeh
- Razi Drug Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Grazia D'onofrio
- Geriatric Unit and Gerontology-Geriatrics Research Laboratory, Department of Medical Sciences, IRCCS "Casa Sollievo della Sofferenza", Viale Cappuccini 1, 71013, San Giovanni Rotondo, FG, Italy.
| | - Ilkay Erdogan Orhan
- Department of Pharmacognosy, Faculty of Pharmacy, Gazi University, 06330, Ankara, Turkey.
| | - Antoni Sureda
- Research Group on Community Nutrition and Oxidative Stress, University of Balearic Islands, CIBEROBN (Physiopathology of Obesity and Nutrition), E-07122, Palma de Mallorca, Balearic Islands, Spain.
| | - Suowen Xu
- Aab Cardiovascular Research Institute, University of Rochester, Rochester, NY, 14623, USA.
| | - Saeedeh Momtaz
- Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran; Toxicology and Diseases Group, The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Hosein Farzaei
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran.
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23
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Liu L, Xu H, Ding S, Wang D, Song G, Huang X. Phosphodiesterase 5 inhibitors as novel agents for the treatment of Alzheimer's disease. Brain Res Bull 2019; 153:223-231. [PMID: 31493542 DOI: 10.1016/j.brainresbull.2019.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/18/2019] [Accepted: 09/01/2019] [Indexed: 01/21/2023]
Abstract
Alzheimer's disease (AD), characterized by a progressive impairment of memory and cognition, is a major health problem in both developing and developed countries. Currently, no drugs can reverse the progression of AD. Phosphodiesterase 5 (PDE5) is a critical component of the cyclic guanosine monophosphate/protein kinase G (cGMP/PKG) signaling pathway in neurons, the inhibition of which has produced neuroprotective effects, and PDE5 inhibitors have recently been thought to be potential therapeutic agents for AD. In this paper, we summarized the outstanding progress that has been made in PDE5 inhibitors as anti-AD agents with encouraging results in animal studies, clinical trials and the investigations on the underlying mechanisms. The novel PDE5 inhibitors reported recently in the treatment of AD were also reviewed and discussed.
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Affiliation(s)
- Li Liu
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu 213164, China
| | - Huang Xu
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu 213164, China
| | - Shumin Ding
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu 213164, China
| | - Dongyan Wang
- Department of Medicine, Yangzhou Polytechnic College, Yangzhou, Jiangsu 225009, China
| | - Guoqiang Song
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu 213164, China.
| | - Xianfeng Huang
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, Jiangsu 213164, China.
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24
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Choi JB, Cho KJ, Kim JC, Kim CH, Chung YA, Jeong HS, Shim YS, Koh JS. The Effect of Daily Low Dose Tadalafil on Cerebral Perfusion and Cognition in Patients with Erectile Dysfunction and Mild Cognitive Impairment. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE 2019; 17:432-437. [PMID: 31352710 PMCID: PMC6705107 DOI: 10.9758/cpn.2019.17.3.432] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 12/14/2018] [Accepted: 12/18/2018] [Indexed: 12/15/2022]
Abstract
Objective The aims of this study were to investigate the effects of daily low-dose tadalafil on cognitive function and to examine whether there was a change in cerebral blood flow (CBF) in patients with erectile dysfunction (ED) and mild cognitive impairment. Methods Male patients aged 50 to 75 years with at least three months of ED (International Index of Erectile Function [IIEF]-5 score ≤ 21) and mild cognitive impairment (Montreal Cognitive Assessment [MoCA] score ≤ 22) were included in the study. The subjects were prescribed a low-dose PDE5 inhibitor (tadalafil 5 mg) to be taken once daily for eight weeks. Changes in MoCA score and single-photon emission computed tomography (SPECT) study between the two time-points were assessed by paired t tests. Results Overall, 30 male patients were assigned to the treatment group in this study and 25 patients completed the eight-week treatment course. Five patients were withdrawn due to adverse events such as myalgia and dizziness. Mean baseline IIEF and MoCA scores were 7.52 ± 4.84 and 18.92 ± 1.78. After the eight-week treatment, mean IIEF and MoCA scores were increased to 12.92 ± 7.27 (p < 0.05) and 21.8 ± 1.71 (p < 0.05), respectively. Patients showed increased relative regional CBF in the postcentral gyrus, precuneus, and brainstem after tadalafil administration versus at baseline (p < 0.001). Conclusion The results of this prospective clinical study suggest that daily use of tadalafil 5 mg increases some regional CBF and improves cognitive function in patients with ED and mild cognitive impairment.
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Affiliation(s)
- Jin Bong Choi
- Departments of Urology College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Kang Jun Cho
- Departments of Urology College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Joon Chul Kim
- Departments of Urology College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Chung Ho Kim
- Departments of Nuclear Medicine The Catholic University of Korea, Seoul, Korea
| | - Yong-An Chung
- Department of Radiology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Hyeonseok S Jeong
- Department of Radiology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Yong Soo Shim
- Neurology, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Jun Sung Koh
- Departments of Urology College of Medicine, The Catholic University of Korea, Seoul, Korea
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25
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Borghans LGJM, Sambeth A, Prickaerts J, Ramaekers JG, Blokland A. The effects of the soluble guanylate cyclase stimulator riociguat on memory performance in healthy volunteers with a biperiden-induced memory impairment. Psychopharmacology (Berl) 2018; 235:2407-2416. [PMID: 29882087 PMCID: PMC6061766 DOI: 10.1007/s00213-018-4938-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 05/30/2018] [Indexed: 10/25/2022]
Abstract
RATIONALE After stimulation with nitric oxide, soluble guanylate cyclase (sGC) produces cyclic guanosine monophosphate (cGMP), which stimulates an important signalling pathway for long-term potentiation (LTP). By upregulating cGMP, LTP could be stimulated and thereby enhancing memory processes. The present study investigated the effects of the sGC stimulator riociguat on cognition in healthy volunteers. Participants were pre-treated with and without biperiden, which impairs memory performance, to investigate the memory-enhancing effects of riociguat. METHODS Twenty volunteers participated in a double-blind placebo-controlled six-way crossover design with a cognitive test battery including the verbal learning task (VLT), n-back task, spatial memory test, the attention network test, and a reaction time task. Treatments were placebo and riociguat 0.5 mg, placebo and riociguat 1.0 mg, biperiden 2.0 mg and placebo, biperiden 2.0 mg and riociguat 0.5 mg and biperiden 2.0 mg and riociguat 1.0 mg. RESULTS Blood pressure was found to be decreased and heart rate to be increased after administration of riociguat. Cognitive performance was not enhanced after administration of riociguat. Biperiden decreased episodic memory on the VLT, yet this deficit was not reversed by riociguat. CONCLUSION This supports the notion that biperiden might be a valuable pharmacological model to induce episodic memory impairments as observed in AD/MCI.
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Affiliation(s)
- Laura G. J. M. Borghans
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, 6229 ER Maastricht, The Netherlands
| | - Anke Sambeth
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, 6229 ER Maastricht, The Netherlands
| | - Jos Prickaerts
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Faculty of Medicine, Health & Life Science, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
| | - Johannes G. Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, 6229 ER Maastricht, The Netherlands
| | - Arjan Blokland
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, 6229 ER Maastricht, The Netherlands
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26
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Heckman PRA, Blokland A, Bollen EPP, Prickaerts J. Phosphodiesterase inhibition and modulation of corticostriatal and hippocampal circuits: Clinical overview and translational considerations. Neurosci Biobehav Rev 2018; 87:233-254. [PMID: 29454746 DOI: 10.1016/j.neubiorev.2018.02.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 02/07/2018] [Accepted: 02/09/2018] [Indexed: 12/20/2022]
Abstract
The corticostriatal and hippocampal circuits contribute to the neurobiological underpinnings of several neuropsychiatric disorders, including Alzheimer's disease, Parkinson's disease and schizophrenia. Based on biological function, these circuits can be clustered into motor circuits, associative/cognitive circuits and limbic circuits. Together, dysfunctions in these circuits produce the wide range of symptoms observed in related neuropsychiatric disorders. Intracellular signaling in these circuits is largely mediated through the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway with an additional role for the cyclic guanosine monophosphate (cGMP)/ protein kinase G (PKG) pathway, both of which can be regulated by phosphodiesterase inhibitors (PDE inhibitors). Through their effects on cAMP response element-binding protein (CREB) and Dopamine- and cAMP-Regulated PhosphoProtein MR 32 kDa (DARPP-32), cyclic nucleotide pathways are involved in synaptic transmission, neuron excitability, neuroplasticity and neuroprotection. In this clinical review, we provide an overview of the current clinical status, discuss the general mechanism of action of PDE inhibitors in relation to the corticostriatal and hippocampal circuits and consider several translational challenges.
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Affiliation(s)
- P R A Heckman
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands; Department of Neuropsychology and Psychopharmacology, Maastricht University, Maastricht, The Netherlands.
| | - A Blokland
- Department of Neuropsychology and Psychopharmacology, Maastricht University, Maastricht, The Netherlands
| | - E P P Bollen
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - J Prickaerts
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
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27
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Ryu SY, Choi YJ, Park SY, Kim JY, Kim YD, Kim YW. Udenafil, a Phosphodiesterase 5 Inhibitor, Reduces Body Weight in High-Fat-Fed Mice. World J Mens Health 2017; 36:41-49. [PMID: 29164831 PMCID: PMC5756806 DOI: 10.5534/wjmh.17028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 09/05/2017] [Accepted: 09/20/2017] [Indexed: 01/22/2023] Open
Abstract
Purpose High-fat (HF) feeding induces hypothalamic leptin resistance via the activation of toll-like receptor 4 (TLR4). TLR4 deficiency confers resistance to diet-induced obesity. Udenafil, an anti-impotence drug, inhibits TLR4 in airway epithelial cells in vitro. In this study, we evaluated whether udenafil suppressed the hypothalamic expression of TLR4 and reduced body weight. Materials and Methods The hypothalamic expression of TLR4, phosphodiesterase 5 (PDE5), nuclear factor-κB (NF-κB), and myeloid differentiation primary response gene 88 (Myd88) was analyzed by real-time polymerase chain reaction after treating mice for 2 days with udenafil (0, 12, 120, or 600 µg/d). Furthermore, the hypothalamic expression of TLR4, pro-opiomelanocortin (POMC), and neuropeptide Y (NPY) was analyzed after 9 days' treatment with udenafil and/or leptin. We also measured body weight and food intake following 9 days of udenafil and/or leptin treatment in control- and HF-fed mice. Results Udenafil suppressed hypothalamic TLR4 mRNA expression dose-dependently. The changes were associated with decreased PDE5, NF-κB, and Myd88 expression. Udenafil treatment for 9 days reduced body weight and caloric intake in HF-fed mice. This may have been associated with the suppression of NPY expression that was elevated by HF feeding. POMC expression was not affected by udenafil. However, udenafil did not augment the effects of leptin on the reduction of body weight and caloric intake in HF-fed mice. Conclusions These results suggested that udenafil reduced body weight by suppressing hypothalamic TLR4 mRNA expression in HF-fed mice and the combination effect of udenafil and leptin was additive rather than synergistic.
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Affiliation(s)
- Seong Yul Ryu
- Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea
| | - Yoon Jung Choi
- Department of Physiology, Yeungnam University College of Medicine, Daegu, Korea
| | - So Young Park
- Department of Physiology, Yeungnam University College of Medicine, Daegu, Korea
| | - Jong Yeon Kim
- Department of Physiology, Yeungnam University College of Medicine, Daegu, Korea
| | - Yong Dae Kim
- Department of Otolaryngology, Yeungnam University College of Medicine, Daegu, Korea
| | - Yong Woon Kim
- Department of Physiology, Yeungnam University College of Medicine, Daegu, Korea.
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28
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Denlinger CS, Sanft T, Baker KS, Baxi S, Broderick G, Demark-Wahnefried W, Friedman DL, Goldman M, Hudson M, Khakpour N, King A, Koura D, Kvale E, Lally RM, Langbaum TS, Melisko M, Montoya JG, Mooney K, Moslehi JJ, O'Connor T, Overholser L, Paskett ED, Peppercorn J, Rodriguez MA, Ruddy KJ, Silverman P, Smith S, Syrjala KL, Tevaarwerk A, Urba SG, Wakabayashi MT, Zee P, Freedman-Cass DA, McMillian NR. Survivorship, Version 2.2017, NCCN Clinical Practice Guidelines in Oncology. J Natl Compr Canc Netw 2017; 15:1140-1163. [PMID: 28874599 PMCID: PMC5865602 DOI: 10.6004/jnccn.2017.0146] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Many cancer survivors experience menopausal symptoms, including female survivors taking aromatase inhibitors or with a history of oophorectomy or chemotherapy, and male survivors who received or are receiving androgen-ablative therapies. Sexual dysfunction is also common in cancer survivors. Sexual dysfunction and menopause-related symptoms can increase distress and have a significant negative impact on quality of life. This portion of the NCCN Guidelines for Survivorship provide recommendations for screening, evaluation, and treatment of sexual dysfunction and menopausal symptoms to help healthcare professionals who work with survivors of adult-onset cancer in the posttreatment period.
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Prickaerts J, Heckman PRA, Blokland A. Investigational phosphodiesterase inhibitors in phase I and phase II clinical trials for Alzheimer's disease. Expert Opin Investig Drugs 2017; 26:1033-1048. [PMID: 28772081 DOI: 10.1080/13543784.2017.1364360] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Phosphodiesterase (PDE) inhibitors improve signaling pathways in brain circuits by increasing intracellular cyclic adenosine monophosphate (cAMP) and/or cyclic guanosine monophosphate (cGMP). In the last decade, the first clinical studies investigating selective PDE inhibitors in Alzheimer's disease (AD) have been initiated, based on their positive effects on cognitive processes and neuroprotection in numerous animal studies. Areas covered: This article reviews the clinical studies investigating the pro-cognitive/neuroprotective effects of PDE inhibitors in patients with AD, as well as in age-associated memory impaired elderly and patients with mild cognitive impairment (MCI), the prodromal stage of AD. PDE inhibitors will also be discussed with respect to adverse effects including safety and tolerability. Expert opinion: The limited available data of clinical studies with PDE inhibitors tested in different populations of AD patients do not allow the drawing of any concrete conclusion yet. Currently, studies with a PDE3 (cilostazol) or PDE9 inhibitor (BI 409,306) are still ongoing in patients with MCI or AD, respectively. Studies with PDE4 inhibitors (HT-0712, roflumilast and BPN14770) in healthy elderly and elderly with age-associated memory impairments indicate that the optimum dose and/or inhibiting the most relevant PDE isoform hold great promise when tested in the appropriate population of patients with MCI or AD eventually.
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Affiliation(s)
- Jos Prickaerts
- a Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience , Maastricht University , Maastricht , The Netherlands
| | - Pim R A Heckman
- a Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience , Maastricht University , Maastricht , The Netherlands.,b Department of Neuropsychology and Psychopharmacology , Maastricht University , Maastricht , The Netherlands
| | - Arjan Blokland
- b Department of Neuropsychology and Psychopharmacology , Maastricht University , Maastricht , The Netherlands
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30
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Abstract
Erectile dysfunction (ED) is one of the most common disorders in male and is often associated with other age-related comorbidities. The aging process affects the structural organization and function of penile erectile components such as smooth muscle cell and vascular architecture. These modifications affect penile hemodynamics by impairing cavernosal smooth muscle cell relaxation, reducing penile elasticity, compliance and promoting fibrosis. This review aims to identify the mechanisms of ED in the penile aging process in experimental and clinical data. It also highlights areas that are in need of more research. The search strategies yielded total records screened from PubMed. Clarification of the molecular mechanisms that accompanies corpus cavernosum aging and aging-associated ED will aid new perspectives in the development of novel mechanism-based therapeutic approaches. Age is not a limiting factor for ED medical management, and it is never too late to treat. Hypogonadism should be managed regardless of age, and synergistic effects have been found during testosterone (T) replacement therapy when used along with oral phosphodiesterase-5 (PDE-5) inhibitors. Therefore, the clinical management of ED related to aging can be done by therapeutic interventions that include PDE-5 inhibitors, and other pharmacological treatments.
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Affiliation(s)
- Ecem Kaya
- a Department of Biochemistry and Pharmacology , Faculty of Pharmacy, Ankara University , Ankara , Turkey and
| | - Suresh C Sikka
- b Department of Urology and Pharmacology , Tulane University Health Sciences Center , New Orleans , LA , USA
| | - Philip J Kadowitz
- b Department of Urology and Pharmacology , Tulane University Health Sciences Center , New Orleans , LA , USA
| | - Serap Gur
- a Department of Biochemistry and Pharmacology , Faculty of Pharmacy, Ankara University , Ankara , Turkey and
- b Department of Urology and Pharmacology , Tulane University Health Sciences Center , New Orleans , LA , USA
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31
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Heckman PRA, Blokland A, Prickaerts J. From Age-Related Cognitive Decline to Alzheimer's Disease: A Translational Overview of the Potential Role for Phosphodiesterases. ADVANCES IN NEUROBIOLOGY 2017; 17:135-168. [PMID: 28956332 DOI: 10.1007/978-3-319-58811-7_6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Phosphodiesterase inhibitors (PDE-Is) are pharmacological compounds enhancing cAMP and/or cGMP signaling. Both these substrates affect neural communication by influencing presynaptic neurotransmitter release and postsynaptic intracellular pathways after neurotransmitter binding to its receptor. Both cAMP and cGMP play an important role in a variety of cellular functions including neuroplasticity and neuroprotection. This chapter provides a translational overview of the effects of different classes of PDE-Is on cognition enhancement in age-related cognitive decline and Alzheimer's disease (AD). The most effective PDE-Is in preclinical models of aging and AD appear to be PDE2-Is, PDE4-Is and PDE5-Is. Clinical studies are relatively sparse and so far PDE1-Is and PDE4-Is showed some promising results. In the future, the demonstration of clinical proof of concept and the generation of isoform selective PDE-Is are the hurdles to overcome in developing safe and efficacious novel PDE-Is for the treatment of age-related cognitive decline and cognitive dysfunction in AD.
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Affiliation(s)
- Pim R A Heckman
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, PO Box 616, 6200, MD, Maastricht, The Netherlands
- Department of Neuropsychology and Psychopharmacology, Maastricht University, PO Box 616, 6200, MD, Maastricht, The Netherlands
| | - Arjan Blokland
- Department of Neuropsychology and Psychopharmacology, Maastricht University, PO Box 616, 6200, MD, Maastricht, The Netherlands
| | - Jos Prickaerts
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, PO Box 616, 6200, MD, Maastricht, The Netherlands.
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32
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Titus DJ, Wilson NM, Freund JE, Carballosa MM, Sikah KE, Furones C, Dietrich WD, Gurney ME, Atkins CM. Chronic Cognitive Dysfunction after Traumatic Brain Injury Is Improved with a Phosphodiesterase 4B Inhibitor. J Neurosci 2016; 36:7095-108. [PMID: 27383587 PMCID: PMC4938858 DOI: 10.1523/jneurosci.3212-15.2016] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 05/20/2016] [Accepted: 05/25/2016] [Indexed: 12/19/2022] Open
Abstract
UNLABELLED Learning and memory impairments are common in traumatic brain injury (TBI) survivors. However, there are no effective treatments to improve TBI-induced learning and memory impairments. TBI results in decreased cAMP signaling and reduced cAMP-response-element binding protein (CREB) activation, a critical pathway involved in learning and memory. TBI also acutely upregulates phosphodiesterase 4B2 (PDE4B2), which terminates cAMP signaling by hydrolyzing cAMP. We hypothesized that a subtype-selective PDE4B inhibitor could reverse the learning deficits induced by TBI. To test this hypothesis, adult male Sprague-Dawley rats received sham surgery or moderate parasagittal fluid-percussion brain injury. At 3 months postsurgery, animals were administered a selective PDE4B inhibitor or vehicle before cue and contextual fear conditioning, water maze training and a spatial working memory task. Treatment with the PDE4B inhibitor significantly reversed the TBI-induced deficits in cue and contextual fear conditioning and water maze retention. To further understand the underlying mechanisms of these memory impairments, we examined hippocampal long-term potentiation (LTP). TBI resulted in a significant reduction in basal synaptic transmission and impaired expression of LTP. Treatment with the PDE4B inhibitor significantly reduced the deficits in basal synaptic transmission and rescued LTP expression. The PDE4B inhibitor reduced tumor necrosis factor-α levels and increased phosphorylated CREB levels after TBI, suggesting that this drug inhibited molecular pathways in the brain known to be regulated by PDE4B. These results suggest that a subtype-selective PDE4B inhibitor is a potential therapeutic to reverse chronic learning and memory dysfunction and deficits in hippocampal synaptic plasticity following TBI. SIGNIFICANCE STATEMENT Currently, there are an estimated 3.2-5.3 million individuals living with disabilities from traumatic brain injury (TBI) in the United States, and 8 of 10 of these individuals report cognitive disabilities (Thurman et al., 1999; Lew et al., 2006; Zaloshnja et al., 2008). One of the molecular mechanisms associated with chronic cognitive disabilities is impaired cAMP signaling in the hippocampus. In this study, we report that a selective phosphodiesterase 4B (PDE4B) inhibitor reduces chronic cognitive deficits after TBI and rescues deficits in hippocampal long-term potentiation. These results suggest that PDE4B inhibition has the potential to improve learning and memory ability and overall functioning for people living with TBI.
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Affiliation(s)
- David J Titus
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136, and
| | - Nicole M Wilson
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136, and
| | - Julie E Freund
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136, and
| | - Melissa M Carballosa
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136, and
| | - Kevin E Sikah
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136, and
| | - Concepcion Furones
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136, and
| | - W Dalton Dietrich
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136, and
| | - Mark E Gurney
- Tetra Discovery Partners, Grand Rapids, Michigan 49503
| | - Coleen M Atkins
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida 33136, and
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Expectations do not Influence the Response to Phosphosdiesterase Type 5 Inhibitor Therapy for Erectile Dysfunction. PHARMACY 2015; 3:295-306. [PMID: 28975917 PMCID: PMC5597108 DOI: 10.3390/pharmacy3040295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 11/04/2015] [Accepted: 11/09/2015] [Indexed: 11/17/2022] Open
Abstract
It has been reported that patients frequently discontinue treatment for erectile dysfunction (ED) with phosphodiesterase type 5 inhibitors (PDE5Is) despite apparently good therapeutic results. Because expectations have been shown to affect patients’ appraisals of many drugs, the purpose of this study was to determine whether expectations affected the therapeutic response to PDE5Is in men with apparent psychogenic ED. An unvalidated questionnaire was used to collect data on expectations in 80 men commencing PDE5I therapy, and after three and six months of treatment. At the same time, subjects completed the International Index of Erectile Function (IIEF), the Sexual Excitation/Inhibition Scale (SIS/SES) and Beck’s Depression Inventory (BDI). No evidence of an effect on expectations on changes in IIEF or BDI scores could be identified. Although changes in IIEF, and BDI scores from recruitment to three months were indicative of improved sexual function and less depression, scores for most items on the expectations scale decreased, suggesting that expectations were not being met. The items for which scores decreased were the expectation to be prescribed a drug, that the drug would restore the sexual function to normal, would work within 30 minutes of administration, improve patients confidence to engage in sexual activity, and that the medication was the best treatment for ED across the three data collection points. The findings of this study indicate that improvements in erectile function did not translate into changes in medication expectations that suggested user satisfaction.
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Franco R. Enhancing cognition before clinical symptoms of dementia. Front Syst Neurosci 2015; 8:240. [PMID: 25565993 PMCID: PMC4267185 DOI: 10.3389/fnsys.2014.00240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 12/01/2014] [Indexed: 11/13/2022] Open
Affiliation(s)
- Rafael Franco
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Barcelona Barcelona, Spain ; CIBERNED: Centro de Investigación en Red sobre Enfermedades Neurodegenerativas, Instituto de Investigación Carlos III Madrid, Spain
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Peixoto CA, Nunes AKS, Garcia-Osta A. Phosphodiesterase-5 Inhibitors: Action on the Signaling Pathways of Neuroinflammation, Neurodegeneration, and Cognition. Mediators Inflamm 2015; 2015:940207. [PMID: 26770022 PMCID: PMC4681825 DOI: 10.1155/2015/940207] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 11/08/2015] [Indexed: 12/16/2022] Open
Abstract
Phosphodiesterase type 5 inhibitors (PDE5-Is) have recently emerged as a potential therapeutic strategy for neuroinflammatory, neurodegenerative, and memory loss diseases. Mechanistically, PDE5-Is produce an anti-inflammatory and neuroprotection effect by increasing expression of nitric oxide synthases and accumulation of cGMP and activating protein kinase G (PKG), the signaling pathway of which is thought to play an important role in the development of several neurodiseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS). The aim of this paper was to review present knowledge of the signaling pathways that underlie the use of PDE5-Is in neuroinflammation, neurogenesis, learning, and memory.
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Affiliation(s)
- Christina Alves Peixoto
- 1Laboratório de Ultraestrutura, Centro de Pesquisa Aggeu Magalhães (FIOCRUZ), 50.740-465 Recife, PE, Brazil
- *Christina Alves Peixoto:
| | - Ana Karolina Santana Nunes
- 1Laboratório de Ultraestrutura, Centro de Pesquisa Aggeu Magalhães (FIOCRUZ), 50.740-465 Recife, PE, Brazil
- 2Universidade Federal de Pernambuco, 50.670-901 Recife, PE, Brazil
| | - Ana Garcia-Osta
- 3Neurobiology of Alzheimer's disease, Neurosciences Division, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
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Blokland A, van Goethem N, Heckman P, Schreiber R, Prickaerts J. Translational issues with the development of cognition enhancing drugs. Front Neurol 2014; 5:190. [PMID: 25309509 PMCID: PMC4174861 DOI: 10.3389/fneur.2014.00190] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 09/11/2014] [Indexed: 12/16/2022] Open
Affiliation(s)
- Arjan Blokland
- Faculty of Psychology and Neuroscience, Department of Neuropsychology and Psychopharmacology, Maastricht University , Maastricht , Netherlands
| | - Nick van Goethem
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University , Maastricht , Netherlands
| | - Pim Heckman
- Faculty of Psychology and Neuroscience, Department of Neuropsychology and Psychopharmacology, Maastricht University , Maastricht , Netherlands ; Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University , Maastricht , Netherlands
| | | | - Jos Prickaerts
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University , Maastricht , Netherlands
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Clyne M. Can PDE5 inhibitors boost brain function? Nat Rev Urol 2013; 11:65. [PMID: 24346005 DOI: 10.1038/nrurol.2013.309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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