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Special Issue "Role of Phosphodiesterase in Biology and Pathology"

A special issue of International Journal of Molecular Sciences (ISSN 1422-0067). This special issue belongs to the section "Biochemistry".

Deadline for manuscript submissions: closed (31 January 2021).

Special Issue Editors

Dr. Fabio Naro
Website
Guest Editor
Università degli Studi di Roma La Sapienza, Rome, Italy
Interests: signal transduction; PDEs; striated muscle
Prof. Dr. Mauro Giorgi

Guest Editor
Dipartimento di Biologia e Biotecnologia “Charles Darwin”, Sapienza, Università di Roma, Piazzale A. Moro 5, 00185 Roma, Italy
Dr. Manuela Pellegrini

Guest Editor
IBBC-CNR, Via E Ramarini 32, Monterotondo, 00015 Roma, Italy

Special Issue Information

Dear Colleagues,

The Special Issue “The role of Phosphodiesterases in Biology and Pathology” will publish the most exciting articles on the role of phosphodiesterases in health and disease. Review articles, commentaries, and experimental papers are welcome. Phosphodiesterases are ubiquitous enzymes which hydrolyze cAMP and cGMP second messengers in a temporal, spatial, and integrated manner according to their expression and localization inside the cell. cAMP and cGMP signaling regulate a huge variety of cell functions; therefore, phosphodiesterases are involved in any aspect of cell biology. In recent years, further research has focused on the role of these proteins in compartmentalization of the cyclic nucleotide signal in a wide number of cell models. The understanding of cell signaling pathways in which phosphodiesterases are involved is of great importance in cell physiology and human pathology. A great number of pharmaceutical inhibitors are available, and over the past few decades, they have been successfully used in the treatment of impotence and chronic pulmonary diseases. New evidence underlines a possible use of phoshodiesterase inhibitors in the treatment of cardiovascular diseases, type 2 diabetes, cancer, inflammation, and many more other pathologies which have recently been identified.

Dr. Fabio Naro
Prof. Dr. Mario Giorgi
Dr. Manuela Pellegrini
Guest Editors

Manuscript Submission Information

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Keywords

  • signal transduction
  • cGMP/cAMP
  • phoshodiesterase
  • beta-adrenergic receptors
  • phosphodiesterase inhibitors
  • inflammation
  • cancer
  • cardiac diseases
  • development
  • nervous system

Published Papers (13 papers)

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Research

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Open AccessArticle
Influence of Phosphodiesterase Inhibition on CRE- and EGR1-Dependent Transcription in a Mouse Hippocampal Cell Line
Int. J. Mol. Sci. 2020, 21(22), 8658; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21228658 - 17 Nov 2020
Abstract
Signaling pathways, depending on the second messenger molecule cAMP, modulate hippocampal cell signaling via influencing transcription factors like cAMP-regulated element-binding protein (CREB) or early growth response 1 EGR1/Krox24/zif268/ZENK (EGR1). Here, we investigated two reporter cell lines derived from an immortalized hippocampal neuronal cell [...] Read more.
Signaling pathways, depending on the second messenger molecule cAMP, modulate hippocampal cell signaling via influencing transcription factors like cAMP-regulated element-binding protein (CREB) or early growth response 1 EGR1/Krox24/zif268/ZENK (EGR1). Here, we investigated two reporter cell lines derived from an immortalized hippocampal neuronal cell line stably expressing a CRE- or EGR1-luciferase reporter gene (HT22CREluc and HT22EGR1luc, respectively). The cells were subjected to phosphodiesterase inhibitors and other cAMP-modulating agents to investigate dose- and time-dependent phosphodiesterase (PDE)-mediated fine-tuning of cAMP-dependent transcriptional signaling. The non-isoform-specific cyclic nucleotide phosphodiesterase (PDE) inhibitor isobutyl-methyl-xanthine (IBMX), as well as selective inhibitors of PDE3 (milrinone) and PDE4 (rolipram), were tested for their ability to elevate CRE- and EGR1-luciferase activity. Pharmacological parameters like onset of activity, maximum activity, and offset of activity were determined. In summary, phosphodiesterase inhibition appeared similarly potent in comparison to adenylate cyclase stimulation or direct activation of protein kinase A (PKA) via specific cAMP agonists and was at least partly mediated by PKA as shown by the selective PKA inhibitor Rp-8-Br-cAMPS. Moreover, transcriptional activation by PDE inhibition was also influenced by organic anion-exchanger action and interacted with fibroblast growth factor (FGF) receptor-mediated pathways. Full article
(This article belongs to the Special Issue Role of Phosphodiesterase in Biology and Pathology)
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Open AccessArticle
Multi-Compartment, Early Disruption of cGMP and cAMP Signalling in Cardiac Myocytes from the mdx Model of Duchenne Muscular Dystrophy
Int. J. Mol. Sci. 2020, 21(19), 7056; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21197056 - 25 Sep 2020
Abstract
Duchenne muscular dystrophy (DMD) is the most frequent and severe form of muscular dystrophy. The disease presents with progressive body-wide muscle deterioration and, with recent advances in respiratory care, cardiac involvement is an important cause of morbidity and mortality. DMD is caused by [...] Read more.
Duchenne muscular dystrophy (DMD) is the most frequent and severe form of muscular dystrophy. The disease presents with progressive body-wide muscle deterioration and, with recent advances in respiratory care, cardiac involvement is an important cause of morbidity and mortality. DMD is caused by mutations in the dystrophin gene resulting in the absence of dystrophin and, consequently, disturbance of other proteins that form the dystrophin-associated protein complex (DAPC), including neuronal nitric oxide synthase (nNOS). The molecular mechanisms that link the absence of dystrophin with the alteration of cardiac function remain poorly understood but disruption of NO-cGMP signalling, mishandling of calcium and mitochondrial disturbances have been hypothesized to play a role. cGMP and cAMP are second messengers that are key in the regulation of cardiac myocyte function and disruption of cyclic nucleotide signalling leads to cardiomyopathy. cGMP and cAMP signals are compartmentalised and local regulation relies on the activity of phosphodiesterases (PDEs). Here, using genetically encoded FRET reporters targeted to distinct subcellular compartments of neonatal cardiac myocytes from the DMD mouse model mdx, we investigate whether lack of dystrophin disrupts local cyclic nucleotide signalling, thus potentially providing an early trigger for the development of cardiomyopathy. Our data show a significant alteration of both basal and stimulated cyclic nucleotide levels in all compartments investigated, as well as a complex reorganization of local PDE activities. Full article
(This article belongs to the Special Issue Role of Phosphodiesterase in Biology and Pathology)
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Open AccessArticle
In Vitro Inhibition of Phosphodiesterase 3B (PDE 3B) by Anthocyanin-Rich Fruit Juice Extracts and Selected Anthocyanins
Int. J. Mol. Sci. 2020, 21(18), 6934; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21186934 - 21 Sep 2020
Abstract
Phosphodiesterases (PDEs) are essential enzymes for the regulation of pathways mediated by cyclic adenosine monophosphate (cAMP). Secondary plant compounds like anthocyanins (ACs) can inhibit PDE activity and, consequently, may be beneficial for lipid metabolism. This study investigated 18 AC-rich juice extracts and pure [...] Read more.
Phosphodiesterases (PDEs) are essential enzymes for the regulation of pathways mediated by cyclic adenosine monophosphate (cAMP). Secondary plant compounds like anthocyanins (ACs) can inhibit PDE activity and, consequently, may be beneficial for lipid metabolism. This study investigated 18 AC-rich juice extracts and pure reference compounds from red fruits for potential inhibitory effects on PDE 3B activity. Extracts were obtained through adsorption on Amberlite® XAD 7 resin. Based on this screening, the chokeberry, blueberry, pomegranate, and cranberry extracts were active, with half maximal inhibitory concentrations (IC50) ranging from 163 ± 3 µg/mL to 180 ± 3 µg/mL. The ACs in these extracts, peonidin-3-glucoside and cyanidin-3-arabinoside, were the most active single compounds (IC50 = 56 ± 20 µg/mL, 108 ± 6 µg/mL). All extracts comprised high amounts of phenolic compounds, as determined by the Folin–Ciocalteu assay, ranging from 39.8 ± 1.5 to 73.5 ± 4.8 g gallic acid equivalents (GAE)/100 g extract. Pomegranate and chokeberry extracts exhibited the largest amounts of polyphenols (72.3 ± 0.7 g GAE/100 g, 70.6 ± 4.1 g GAE/100 g, respectively). Overall, our results showed that fruit juice extracts and their ACs can inhibit PDE activity. Any potential health benefits in vivo will be investigated in the future. Full article
(This article belongs to the Special Issue Role of Phosphodiesterase in Biology and Pathology)
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Open AccessArticle
Dominant-Negative Attenuation of cAMP-Selective Phosphodiesterase PDE4D Action Affects Learning and Behavior
Int. J. Mol. Sci. 2020, 21(16), 5704; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21165704 - 09 Aug 2020
Abstract
PDE4 cyclic nucleotide phosphodiesterases reduce 3′, 5′ cAMP levels in the CNS and thereby regulate PKA activity and the phosphorylation of CREB, fundamental to depression, cognition, and learning and memory. The PDE4 isoform PDE4D5 interacts with the signaling proteins β-arrestin2 and RACK1, regulators [...] Read more.
PDE4 cyclic nucleotide phosphodiesterases reduce 3′, 5′ cAMP levels in the CNS and thereby regulate PKA activity and the phosphorylation of CREB, fundamental to depression, cognition, and learning and memory. The PDE4 isoform PDE4D5 interacts with the signaling proteins β-arrestin2 and RACK1, regulators of β2-adrenergic and other signal transduction pathways. Mutations in PDE4D in humans predispose to acrodysostosis, associated with cognitive and behavioral deficits. To target PDE4D5, we developed mice that express a PDE4D5-D556A dominant-negative transgene in the brain. Male transgenic mice demonstrated significant deficits in hippocampus-dependent spatial learning, as assayed in the Morris water maze. In contrast, associative learning, as assayed in a fear conditioning assay, appeared to be unaffected. Male transgenic mice showed augmented activity in prolonged (2 h) open field testing, while female transgenic mice showed reduced activity in the same assay. Transgenic mice showed no demonstrable abnormalities in prepulse inhibition. There was also no detectable difference in anxiety-like behavior, as measured in the elevated plus-maze. These data support the use of a dominant-negative approach to the study of PDE4D5 function in the CNS and specifically in learning and memory. Full article
(This article belongs to the Special Issue Role of Phosphodiesterase in Biology and Pathology)
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Open AccessArticle
Chronic Sildenafil Treatment Improves Vasomotor Function in a Mouse Model of Accelerated Aging
Int. J. Mol. Sci. 2020, 21(13), 4667; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21134667 - 30 Jun 2020
Abstract
Aging leads to a loss of vasomotor control. Both vasodilation and vasoconstriction are affected. Decreased nitric oxide–cGMP-mediated relaxation is a hallmark of aging. It contributes to vascular disease, notably hypertension, infarction, and dementia. Decreased vasodilation can be caused by aging independently from cardiovascular [...] Read more.
Aging leads to a loss of vasomotor control. Both vasodilation and vasoconstriction are affected. Decreased nitric oxide–cGMP-mediated relaxation is a hallmark of aging. It contributes to vascular disease, notably hypertension, infarction, and dementia. Decreased vasodilation can be caused by aging independently from cardiovascular risk factors. This process that can be mimicked in mice in an accelerated way by activation of the DNA damage response. Genetic deletion of the DNA repair enzyme ERCC1 endonuclease in mice, as in the case of Ercc1Δ/- mice, can be used as a tool to accelerate aging. Ercc1Δ/- mice develop age-dependent vasomotor dysfunction from two months after birth. In the present study we tested if chronic treatment with sildenafil, a phosphodiesterase 5 inhibitor that augments NO–cGMP signaling, can reduce the development of vasomotor dysfunction in Ercc1Δ/- mice. Ercc1Δ/- mice and wild-type littermates were treated with 10 mg/kg/d of sildenafil from the age of 6 to the age of 14 weeks. Blood pressure and in vivo and ex vivo vasomotor responses were measured at the end of the treatment period. Ercc1Δ/- mice developed decreased reactive hyperemia, and diminished NO–cGMP-dependent acetylcholine responses. The diminished acetylcholine response involved both endothelial and vascular smooth muscle cell signaling. Chronic sildenafil exclusively improved NO–cGMP signaling in VSMC, and had no effect on endothelium-derived hyperpolarization. Sildenafil also improved KCl hypocontractility in Ercc1Δ/- mice. All effects were blood pressure-independent. The findings might be of clinical importance for prevention of morbidities related to vascular aging as well as for progeria patients with a high risk of cardiovascular disease. Full article
(This article belongs to the Special Issue Role of Phosphodiesterase in Biology and Pathology)
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Open AccessArticle
PDE2A Is Indispensable for Mouse Liver Development and Hematopoiesis
Int. J. Mol. Sci. 2020, 21(8), 2902; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21082902 - 21 Apr 2020
Abstract
Phosphodiesterase 2A (PDE2A) is a cAMP-cGMP hydrolyzing enzyme essential for mouse development and the PDE2A knockout model (PDE2A−/−) is embryonic lethal. Notably, livers of PDE2A−/− embryos at embryonic day 14.5 (E14.5) have extremely reduced size. Morphological, cellular and molecular [...] Read more.
Phosphodiesterase 2A (PDE2A) is a cAMP-cGMP hydrolyzing enzyme essential for mouse development and the PDE2A knockout model (PDE2A−/−) is embryonic lethal. Notably, livers of PDE2A−/− embryos at embryonic day 14.5 (E14.5) have extremely reduced size. Morphological, cellular and molecular analyses revealed loss of integrity in the PDE2A−/− liver niche that compromises the hematopoietic function and maturation. Hematopoietic cells isolated from PDE2A−/− livers are instead able to differentiate in in vitro assays, suggesting the absence of blood cell-autonomous defects. Apoptosis was revealed in hepatoblasts and at the endothelial and stromal compartments in livers of PDE2A−/− embryos. The increase of the intracellular cAMP level and of the inducible cAMP early repressor (ICER) in liver of PDE2A−/− embryos might explain the impairment of liver development by downregulating the expression of the anti-apoptotic gene Bcl2. In summary, we propose PDE2A as an essential gene for integrity maintenance of liver niche and the accomplishment of hematopoiesis. Full article
(This article belongs to the Special Issue Role of Phosphodiesterase in Biology and Pathology)
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Review

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Open AccessReview
Phosphodiesterase Inhibitors in Acute Lung Injury: What Are the Perspectives?
Int. J. Mol. Sci. 2021, 22(4), 1929; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms22041929 - 16 Feb 2021
Abstract
Despite progress in understanding the pathophysiology of acute lung damage, currently approved treatment possibilities are limited to lung-protective ventilation, prone positioning, and supportive interventions. Various pharmacological approaches have also been tested, with neuromuscular blockers and corticosteroids considered as the most promising. However, inhibitors [...] Read more.
Despite progress in understanding the pathophysiology of acute lung damage, currently approved treatment possibilities are limited to lung-protective ventilation, prone positioning, and supportive interventions. Various pharmacological approaches have also been tested, with neuromuscular blockers and corticosteroids considered as the most promising. However, inhibitors of phosphodiesterases (PDEs) also exert a broad spectrum of favorable effects potentially beneficial in acute lung damage. This article reviews pharmacological action and therapeutical potential of nonselective and selective PDE inhibitors and summarizes the results from available studies focused on the use of PDE inhibitors in animal models and clinical studies, including their adverse effects. The data suggest that xanthines as representatives of nonselective PDE inhibitors may reduce acute lung damage, and decrease mortality and length of hospital stay. Various (selective) PDE3, PDE4, and PDE5 inhibitors have also demonstrated stabilization of the pulmonary epithelial–endothelial barrier and reduction the sepsis- and inflammation-increased microvascular permeability, and suppression of the production of inflammatory mediators, which finally resulted in improved oxygenation and ventilatory parameters. However, the current lack of sufficient clinical evidence limits their recommendation for a broader use. A separate chapter focuses on involvement of cyclic adenosine monophosphate (cAMP) and PDE-related changes in its metabolism in association with coronavirus disease 2019 (COVID-19). The chapter illuminates perspectives of the use of PDE inhibitors as an add-on treatment based on actual experimental and clinical trials with preliminary data suggesting their potential benefit. Full article
(This article belongs to the Special Issue Role of Phosphodiesterase in Biology and Pathology)
Open AccessReview
Role of Phosphodiesterase in the Biology and Pathology of Diabetes
Int. J. Mol. Sci. 2020, 21(21), 8244; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21218244 - 03 Nov 2020
Abstract
Glucose metabolism is the initiator of a large number of molecular secretory processes in β cells. Cyclic nucleotides as a second messenger are the main physiological regulators of these processes and are functionally divided into compartments in pancreatic cells. Their intracellular concentration is [...] Read more.
Glucose metabolism is the initiator of a large number of molecular secretory processes in β cells. Cyclic nucleotides as a second messenger are the main physiological regulators of these processes and are functionally divided into compartments in pancreatic cells. Their intracellular concentration is limited by hydrolysis led by one or more phosphodiesterase (PDE) isoenzymes. Literature data confirmed multiple expressions of PDEs subtypes, but the specific roles of each in pancreatic β-cell function, particularly in humans, are still unclear. Isoforms present in the pancreas are also found in various tissues of the body. Normoglycemia and its strict control are supported by the appropriate release of insulin from the pancreas and the action of insulin in peripheral tissues, including processes related to homeostasis, the regulation of which is based on the PDE- cyclic AMP (cAMP) signaling pathway. The challenge in developing a therapeutic solution based on GSIS (glucose-stimulated insulin secretion) enhancers targeted at PDEs is the selective inhibition of their activity only within β cells. Undeniably, PDEs inhibitors have therapeutic potential, but some of them are burdened with certain adverse effects. Therefore, the chance to use knowledge in this field for diabetes treatment has been postulated for a long time. Full article
(This article belongs to the Special Issue Role of Phosphodiesterase in Biology and Pathology)
Open AccessReview
Advances, Perspectives and Potential Engineering Strategies of Light-Gated Phosphodiesterases for Optogenetic Applications
Int. J. Mol. Sci. 2020, 21(20), 7544; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21207544 - 13 Oct 2020
Abstract
The second messengers, cyclic adenosine 3′-5′-monophosphate (cAMP) and cyclic guanosine 3′-5′-monophosphate (cGMP), play important roles in many animal cells by regulating intracellular signaling pathways and modulating cell physiology. Environmental cues like temperature, light, and chemical compounds can stimulate cell surface receptors and trigger [...] Read more.
The second messengers, cyclic adenosine 3′-5′-monophosphate (cAMP) and cyclic guanosine 3′-5′-monophosphate (cGMP), play important roles in many animal cells by regulating intracellular signaling pathways and modulating cell physiology. Environmental cues like temperature, light, and chemical compounds can stimulate cell surface receptors and trigger the generation of second messengers and the following regulations. The spread of cAMP and cGMP is further shaped by cyclic nucleotide phosphodiesterases (PDEs) for orchestration of intracellular microdomain signaling. However, localized intracellular cAMP and cGMP signaling requires further investigation. Optogenetic manipulation of cAMP and cGMP offers new opportunities for spatio-temporally precise study of their signaling mechanism. Light-gated nucleotide cyclases are well developed and applied for cAMP/cGMP manipulation. Recently discovered rhodopsin phosphodiesterase genes from protists established a new and direct biological connection between light and PDEs. Light-regulated PDEs are under development, and of demand to complete the toolkit for cAMP/cGMP manipulation. In this review, we summarize the state of the art, pros and cons of artificial and natural light-regulated PDEs, and discuss potential new strategies of developing light-gated PDEs for optogenetic manipulation. Full article
(This article belongs to the Special Issue Role of Phosphodiesterase in Biology and Pathology)
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Open AccessReview
Therapeutic Implications for PDE2 and cGMP/cAMP Mediated Crosstalk in Cardiovascular Diseases
Int. J. Mol. Sci. 2020, 21(20), 7462; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21207462 - 10 Oct 2020
Cited by 1
Abstract
Phosphodiesterases (PDEs) are the principal superfamily of enzymes responsible for degrading the secondary messengers 3′,5′-cyclic nucleotides cAMP and cGMP. Their refined subcellular localization and substrate specificity contribute to finely regulate cAMP/cGMP gradients in various cellular microdomains. Redistribution of multiple signal compartmentalization components is [...] Read more.
Phosphodiesterases (PDEs) are the principal superfamily of enzymes responsible for degrading the secondary messengers 3′,5′-cyclic nucleotides cAMP and cGMP. Their refined subcellular localization and substrate specificity contribute to finely regulate cAMP/cGMP gradients in various cellular microdomains. Redistribution of multiple signal compartmentalization components is often perceived under pathological conditions. Thereby PDEs have long been pursued as therapeutic targets in diverse disease conditions including neurological, metabolic, cancer and autoimmune disorders in addition to numerous cardiovascular diseases (CVDs). PDE2 is a unique member of the broad family of PDEs. In addition to its capability to hydrolyze both cAMP and cGMP, PDE2 is the sole isoform that may be allosterically activated by cGMP increasing its cAMP hydrolyzing activity. Within the cardiovascular system, PDE2 serves as an integral regulator for the crosstalk between cAMP/cGMP pathways and thereby may couple chronically adverse augmented cAMP signaling with cardioprotective cGMP signaling. This review provides a comprehensive overview of PDE2 regulatory functions in multiple cellular components within the cardiovascular system and also within various subcellular microdomains. Implications for PDE2- mediated crosstalk mechanisms in diverse cardiovascular pathologies are discussed highlighting the prospective use of PDE2 as a potential therapeutic target in cardiovascular disorders. Full article
(This article belongs to the Special Issue Role of Phosphodiesterase in Biology and Pathology)
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Open AccessReview
Phosphodiesterases in the Liver as Potential Therapeutic Targets of Cirrhotic Portal Hypertension
Int. J. Mol. Sci. 2020, 21(17), 6223; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21176223 - 28 Aug 2020
Cited by 2
Abstract
Liver cirrhosis is a frequent condition with high impact on patients’ life expectancy and health care systems. Cirrhotic portal hypertension (PH) gradually develops with deteriorating liver function and can lead to life-threatening complications. Other than an increase in intrahepatic flow resistance due to [...] Read more.
Liver cirrhosis is a frequent condition with high impact on patients’ life expectancy and health care systems. Cirrhotic portal hypertension (PH) gradually develops with deteriorating liver function and can lead to life-threatening complications. Other than an increase in intrahepatic flow resistance due to morphological remodeling of the organ, a functional dysregulation of the sinusoids, the smallest functional units of liver vasculature, plays a pivotal role. Vascular tone is primarily regulated by the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway, wherein soluble guanylate cyclase (sGC) and phosphodiesterase-5 (PDE-5) are key enzymes. Recent data showed characteristic alterations in the expression of these regulatory enzymes or metabolite levels in liver cirrhosis. Additionally, a disturbed zonation of the components of this pathway along the sinusoids was detected. This review describes current knowledge of the pathophysiology of PH with focus on the enzymes regulating cGMP availability, i.e., sGC and PDE-5. The results have primarily been obtained in animal models of liver cirrhosis. However, clinical and histochemical data suggest that the new biochemical model we propose can be applied to human liver cirrhosis. The role of PDE-5 as potential target for medical therapy of PH is discussed. Full article
(This article belongs to the Special Issue Role of Phosphodiesterase in Biology and Pathology)
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Open AccessReview
Role of Phosphodiesterase 7 (PDE7) in T Cell Activity. Effects of Selective PDE7 Inhibitors and Dual PDE4/7 Inhibitors on T Cell Functions
Int. J. Mol. Sci. 2020, 21(17), 6118; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21176118 - 25 Aug 2020
Cited by 1
Abstract
Phosphodiesterase 7 (PDE7), a cAMP-specific PDE family, insensitive to rolipram, is present in many immune cells, including T lymphocytes. Two genes of PDE7 have been identified: PDE7A and PDE7B with three or four splice variants, respectively. Both PDE7A and PDE7B are expressed in [...] Read more.
Phosphodiesterase 7 (PDE7), a cAMP-specific PDE family, insensitive to rolipram, is present in many immune cells, including T lymphocytes. Two genes of PDE7 have been identified: PDE7A and PDE7B with three or four splice variants, respectively. Both PDE7A and PDE7B are expressed in T cells, and the predominant splice variant in these cells is PDE7A1. PDE7 is one of several PDE families that terminates biological functions of cAMP—a major regulating intracellular factor. However, the precise role of PDE7 in T cell activation and function is still ambiguous. Some authors reported its crucial role in T cell activation, while according to other studies PDE7 activity was not pivotal to T cells. Several studies showed that inhibition of PDE7 by its selective or dual PDE4/7 inhibitors suppresses T cell activity, and consequently T-mediated immune response. Taken together, it seems quite likely that simultaneous inhibition of PDE4 and PDE7 by dual PDE4/7 inhibitors or a combination of selective PDE4 and PDE7 remains the most interesting therapeutic target for the treatment of some immune-related disorders, such as autoimmune diseases, or selected respiratory diseases. An interesting direction of future studies could also be using a combination of selective PDE7 and PDE3 inhibitors. Full article
(This article belongs to the Special Issue Role of Phosphodiesterase in Biology and Pathology)
Open AccessReview
Phosphodiesterase Inhibitors: Could They Be Beneficial for the Treatment of COVID-19?
Int. J. Mol. Sci. 2020, 21(15), 5338; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21155338 - 27 Jul 2020
Cited by 6
Abstract
In March 2020, the World Health Organization declared the severe acute respiratory syndrome corona virus 2 (SARS-CoV2) infection to be a pandemic disease. SARS-CoV2 was first identified in China and, despite the restrictive measures adopted, the epidemic has spread globally, becoming a pandemic [...] Read more.
In March 2020, the World Health Organization declared the severe acute respiratory syndrome corona virus 2 (SARS-CoV2) infection to be a pandemic disease. SARS-CoV2 was first identified in China and, despite the restrictive measures adopted, the epidemic has spread globally, becoming a pandemic in a very short time. Though there is growing knowledge of the SARS-CoV2 infection and its clinical manifestations, an effective cure to limit its acute symptoms and its severe complications has not yet been found. Given the worldwide health and economic emergency issues accompanying this pandemic, there is an absolute urgency to identify effective treatments and reduce the post infection outcomes. In this context, phosphodiesterases (PDEs), evolutionarily conserved cyclic nucleotide (cAMP/cGMP) hydrolyzing enzymes, could emerge as new potential targets. Given their extended distribution and modulating role in nearly all organs and cellular environments, a large number of drugs (PDE inhibitors) have been developed to control the specific functions of each PDE family. These PDE inhibitors have already been used in the treatment of pathologies that show clinical signs and symptoms completely or partially overlapping with post-COVID-19 conditions (e.g., thrombosis, inflammation, fibrosis), while new PDE-selective or pan-selective inhibitors are currently under study. This review discusses the state of the art of the different pathologies currently treated with phosphodiesterase inhibitors, highlighting the numerous similarities with the disorders linked to SARS-CoV2 infection, to support the hypothesis that PDE inhibitors, alone or in combination with other drugs, could be beneficial for the treatment of COVID-19. Full article
(This article belongs to the Special Issue Role of Phosphodiesterase in Biology and Pathology)
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