Search Results (323)

Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin disorder characterized by immune dysregulation and epidermal barrier dysfunction. Advances in understanding the interplay of genetic predisposition, cytokine signaling, and environmental triggers have led to the emergence of targeted therapies. Although biologic agents such as dupilumab, tralokinumab, and lebrikizumab have revolutionized AD management, their high costs, injectable administration, and limited global accessibility highlight the need for alternative options. Small molecule therapies are gaining momentum as they target intracellular pathways central to AD pathogenesis and offer oral or topical administration routes. This review provides a comprehensive analysis of key agents including Janus kinase (JAK) inhibitors (upadacitinib, abrocitinib, baricitinib, ruxolitinib, delgocitinib), phosphodiesterase 4 (PDE4) inhibitors (crisaborole, difamilast, roflumilast, apremilast), as well as STAT6 degraders (KT621, NX3911), aryl hydrocarbon receptor modulators, histamine H4 receptor antagonists (adriforant, izuforant), and sphingosine-1-phosphate receptor modulators (etrasimod, BMS-986166). We summarize their mechanisms of action, pharmacological profiles, and pivotal clinical trial data, emphasizing their potential to address unmet therapeutic needs. Finally, we discuss safety concerns, long-term tolerability, and future directions for integrating small molecule therapies into precision treatment strategies for moderate-to-severe AD. Full article

We report here two new series of designed PDE4 inhibitors, the first one showing the quinoline scaffold recently investigated by us through a fragment-based drug design strategy, and the second consisting of pyrazolo [1′,5′:1,6]pyrimido[4,5-d]pyridazine derivatives. Both the new series were subjected to biological studies to assess their inhibitory effect on PDE4 enzymes, supported by molecular modelling experiments, to rationalize the different activities recorded in the in vitro tests. Interesting results were achieved for two compounds belonging to the tricyclic series, namely 10a and 10e, exhibiting IC₅₀ = 62 and 175.5 nM, respectively. These results could represent the starting point for further studies with the aim of developing new and effective PDE4 inhibitors for biomedical investigations. Full article

Background: Signaling pathways like those depending on cAMP/PKA, calcium/calmodulin/CaMK, MEK-1/MAPK or PI3K/Akt have been described to modulate suprachiasmatic nucleus (SCN) neuronal signaling via influencing transcription factors like CREB. Here, we analyzed the effect of cyclic nucleotide phosphodiesterase inhibitors and structurally similar substances commonly used as autophagy modulators on a cell line stably expressing a cyclic nucleotide element-driven luciferase reporter. Methods: We used an SCN cell line stably transfected with a CRE-luciferase reporter (SCNCRE) to evaluate signaling and vitality responses to various isoform-selective PDE inhibitors and autophagy modulators to evaluate the mechanism of action of the latter. Results: In this study the different impacts of common PDE inhibitors and autophagy modulators on CRE-luciferase activity applied alone and in combination with known CRE-luciferase activating agents showed that (1) PDE3, 4 and 5 are present in SCNCRE cells, with (2) PDE3 being the most active and (3) the autophagy inhibitor 3-Methyladenin (3-MA) displaying PDE inhibitor-like behavior. Conclusions: Experiments provide evidence that, in addition to the extracellular signaling pathways components shown before to be involved in CRE-luciferase activity regulation like cAMP analogs, adenylate cyclase activators and beta-adrenoceptor agonists, cyclic nucleotide metabolism as realized by phosphodiesterase activity, or molecule/agents influencing processes like autophagy or inflammation, modulate transcriptional CRE-dependent activity in these cells. Specifically, we provide evidence that the autophagy inhibitor 3-MA, given that PDEs are expressed, may also act as a PDE inhibitor and inducer of CRE-mediated transcriptional activity. Full article

Background: Phosphodiesterase type 5 inhibitors (PDE5i), particularly tadalafil and sildenafil, are the first-line therapies for erectile dysfunction (ED). After the patent expiration of branded tadalafil in 2017, generic formulations became available. Despite equivalent efficacy, skepticism persists regarding the effectiveness and safety of generics. The SHIFT study aimed to evaluate the non-inferiority of a generic tadalafil (Dalerpen) compared with branded and other generic tadalafil in terms of clinical efficacy and patient satisfaction. Methods: A prospective, multicenter study was conducted involving 247 patients treated with tadalafil (either 5 mg or 20 mg) for ED. Patients switched from branded or other generic tadalafil to Dalerpen. Baseline and follow-up assessments included the International Index of Erectile Function—Erectile Function Domain (IIEF-EF) (primary endpoint), Sexual Encounter Profile (SEP-2 and SEP-3), and International Prostatic Symptom Score (IPSS). A one-month follow-up was performed. Results: A total of 247 patients were included in the final analysis. After switching to Dalerpen, significant improvements were observed in both IIEF-EF (18.8 ± 5.6 vs. 16.7 ± 5.4, p < 0.001) and IPSS scores (10.4 ± 6.7 vs. 11.2 ± 6.3, p < 0.001), though the minimal clinically important difference (MCID) was not reached. SEP-3 scores also significantly increased (3 ± 1.2 vs. 2 ± 1.1, p < 0.001). Multivariate analysis identified baseline IIEF, IPSS scores, and post-treatment IPSS as predictors of IIEF-EF improvement (p < 0.001). Switching to Dalerpen was an independent predictor of both IIEF-EF and IPSS improvement. No new adverse events were reported. Conclusions: The SHIFT study demonstrates that Dalerpen is non-inferior to branded tadalafil in terms of clinical efficacy, offering a reliable and cost-effective therapeutic option. Educating patients on bioequivalence and addressing concerns regarding generic drugs are essential to facilitate therapeutic switches. Full article

Phosphodiesterase type 5 (PDE5) inhibitors, including sildenafil, tadalafil, and vardenafil, are primarily prescribed for erectile dysfunction and pulmonary hypertension. Emerging evidence suggests they may also modulate inflammatory pathways and improve vascular function, but their effects on inflammatory biomarkers in humans remain incompletely defined. A systematic review and meta-analysis were conducted to evaluate the impact of PDE5 inhibitors on inflammatory and endothelial markers in adult humans. Randomized controlled trials comparing PDE5 inhibition to placebo were identified through electronic database searches. Outcomes included pro-inflammatory markers (TNF-α, IL-6, IL-8, CRP, VCAM-1, ICAM-1, P-selectin) and anti-inflammatory or signalling markers (IL-10, NO, cGMP), assessed at short-term (≤1 week), intermediate-term (4–6 weeks), or long-term (≥12 weeks) follow-up. Risk of bias was assessed using the Cochrane RoB 2 tool. A total of 20 studies comprising 1549 participants were included. Meta-analyses showed no significant short-term effects of PDE5 inhibition on TNF-α, IL-6, or CRP. Long-term treatment was associated with reduced IL-6 (SMD = −0.64, p = 0.002) and P-selectin (SMD = −0.57, p = 0.02), and increased cGMP (SMD = 0.87, p = 0.0003). Effects on IL-10 and nitric oxide were inconsistent across studies. Most trials had low risk of bias. PDE5 inhibitors may exert anti-inflammatory effects in long-term use by reducing vascular inflammation and enhancing cGMP signalling. These findings support further investigation of PDE5 in chronic inflammatory conditions. Full article

Background: Coagulation disorders, including both bleeding and thrombotic complications, are common in patients undergoing hemodialysis (HD). Here, we aimed to characterize platelet function in patients undergoing hemodialysis three times per week, compared to healthy controls. Methods: Platelet function was assessed using the Multiplate analyzer (Roche), which is based on multiple electrode impedance aggregometry. Platelet aggregation was induced using adenosine diphosphate (ADP), and the area under the curve (AUC) served as the primary endpoint. In addition, platelet counts and C-reactive protein (CRP) levels were measured. To further evaluate nitric oxide (NO)-mediated inhibition of platelet aggregation, blood samples were incubated with the NO donor, sodium nitroprusside (SNP), and the phosphodiesterase 5A (PDE5A) inhibitor, sildenafil. Results: A total of 60 patients undergoing HD and 67 healthy controls were included in the analysis. Patients receiving HD treatment had significantly lower platelet counts compared to healthy controls (226.9 ± 53.47 vs. 246.7 ± 47.21 G/L, p = 0.029). Platelet aggregation was markedly reduced in patients undergoing HD compared to controls (462.0 ± 266.54 vs. 644.5 ± 254.44 AU × min, p < 0.001) with a significant correlation for platelet count (r = 0.42, p = 0.001) and systemic inflammation as indicated by CRP levels (r = 0.28, p = 0.035). Following SNP and sildenafil administration, inhibition of platelet aggregation remained more pronounced in patients undergoing HD. However, the change in platelet aggregation after SNP/sildenafil treatment did not differ significantly between the groups. Conclusions: Patients undergoing HD exhibit altered platelet function, indicated by reduced aggregation and platelet counts, as well as an association with systemic inflammation. Multiple electrode impedance aggregometry appears to be a feasible method for detecting platelet function alterations in patients receiving HD treatment. Responsiveness to NO donors was preserved in patients undergoing HD. Further studies are needed to identify the underlying mechanisms, particularly the role of NO signaling in platelet dysfunction in patients undergoing HD. Full article

Background: The European League Against Rheumatism (EULAR), in collaboration with the European Scleroderma Trial and Research group (EUSTAR), published the first set of treatment recommendations for systemic sclerosis (SSc) in 2009, with subsequent updates in 2016 and 2023. Objectives: This study aimed to evaluate how rheumatologists’ clinical approaches to the treatment of SSc evolved following the 2016 update of the clinical management guidelines. Methods: Medication use for SSc was analyzed in a cohort of 378 patients. The patients were stratified based on enrollment before (233 patients) and after (145 patients) the guideline update, and medication usage was compared between the two groups. Results: Although all patients presented with Raynaud’s phenomenon (RP), only 35% received calcium channel blockers. Medications such as iloprost, phosphodiesterase type 5 (PDE-5) inhibitors, fluoxetine, and bosentan, recommended for the treatment of RP and digital ulcers, were not approved for SSc by the Republic Health Insurance Fund. Treatment for pulmonary arterial hypertension (PAH) was administered to only 16 patients (4.2%), including 2 who received bosentan, 10 who received PDE-5 inhibitors, and 4 who were treated with riociguat. The use of PDE-5 inhibitors increased following the 2016 update of the guidelines. Cyclophosphamide was consistently prescribed for interstitial lung disease (ILD), with an increased frequency observed after the guideline update. No significant differences were observed in the use of methotrexate for skin involvement, ACE inhibitors for scleroderma renal crisis, or antibiotics for gastrointestinal symptoms. Proton pump inhibitors (PPIs) were prescribed to 87.3% of patients with gastrointestinal involvement, with an increase in use of both PPIs and prokinetic agents following the guideline update. Conclusions: Rheumatologists’ adherence to the EULAR/EUSTAR guidelines varied considerably, with 25% to 100% of eligible patients receiving the recommended treatments. Concordance improved in the management of PAH, ILD, and gastrointestinal involvement after the 2016 guideline update. Full article

Cancer remains a leading cause of mortality worldwide, necessitating innovative therapeutic strategies. Drug repurposing offers a cost-effective approach to cancer treatment by identifying new anticancer applications for existing drugs. Terbutaline, a β2-adrenergic receptor agonist, and Milrinone, a phosphodiesterase-3 inhibitor, are traditionally used as positive inotropic agents but have shown potential anticancer effects. This review explores their mechanisms of action in cancer, focusing on their roles in modulating cyclic adenosine monophosphate (cAMP) levels, oxidative stress, and the tumor microenvironment. Terbutaline influences β2-adrenergic signaling, impacting cell proliferation, angiogenesis, and immune evasion. Milrinone, through PDE3 inhibition, elevates cAMP, promoting apoptosis and reducing tumor growth. Both agents exhibit anti-inflammatory and anti-angiogenic properties, suggesting their potential as adjuvant therapies in oncology. Despite promising preclinical data, clinical validation is required to confirm their efficacy and safety in cancer patients. This review highlights the therapeutic promise of repurposing Terbutaline and Milrinone, emphasizing the need for further research to optimize their application in cancer therapy. Full article

Bariatric surgery involves major changes in the anatomy and physiology of the gastrointestinal tract, which may alter oral drug bioavailability and efficacy. Phosphodiesterase-5 inhibitor (PDE5i) drugs are the first-line treatment of erectile dysfunction, a condition associated with a higher BMI. In this paper, we examine the PDE5i vardenafil for possible post-bariatric changes in solubility/dissolution and absorption. Vardenafil solubility was determined in vitro, as well as ex vivo using aspirated gastric contents from patients prior to vs. following bariatric procedures. Dissolution was tested in vitro under unoperated stomach vs. post-gastric sleeve/bypass conditions. Lastly, the gathered solubility/dissolution data were used to produce an in silico physiologically based pharmacokinetic (PBPK) model (GastroPlus^®), where gastric volume, pH, and transit time, as well as proximal GI bypass (when relevant) were all adjusted for, evaluating vardenafil dissolution, gastrointestinal compartmental absorption, and pharmacokinetics before vs. after different bariatric procedures. pH-dependent solubility was demonstrated for vardenafil with low (pH 7) vs. high solubility (pH 1–5), which was confirmed ex vivo. The impaired dissolution of all vardenafil doses under post-gastric bypass conditions was demonstrated, contrary to complete (100%) dissolution under pre-surgery and post-sleeve gastrectomy conditions. Compared to unoperated individuals, PBPK simulations revealed altered pharmacokinetics post-gastric bypass (but not after sleeve gastrectomy), with 30% lower peak plasma concentration (C_max) and 40% longer time to C_max (T_max). Complete absorption after gastric bypass is predicted for vardenafil, which is attributable to significant absorption from the large intestine. The biopharmaceutics and PBPK analysis indicate that vardenafil may be similarly effective after sleeve gastrectomy as before the procedure. However, results after gastric bypass question the effectiveness of this PDE5i. Specifically, vardenafil’s onset of action might be delayed and unpredictable, negatively affecting the practicality of the intended use. Full article

Right heart failure (RHF) is a major cause of morbidity and mortality, often resulting from pulmonary arterial hypertension and characterized by impaired calcium (Ca²⁺) handling and maladaptive remodeling. Phosphodiesterase 9A (PDE9A), a cGMP-specific phosphodiesterase, has been proposed as a potential contributor to RHF pathogenesis by suppressing the cardioprotective cGMP–PKG signaling pathway—a conclusion largely extrapolated from left-sided heart failure models. This review examines existing evidence regarding PDE9A’s role in RHF, focusing on its effects on intracellular calcium cycling, fibrosis, hypertrophy, and contractile dysfunction. Data from preclinical models demonstrate that pathological stress upregulates PDE9A expression in cardiomyocytes, leading to diminished PKG activation, impaired SERCA2a function, RyR2 instability, and increased arrhythmogenic Ca²⁺ leak. Pharmacological or genetic inhibition of PDE9A restores cGMP signaling, improves calcium handling, attenuates hypertrophic and fibrotic remodeling, and enhances ventricular compliance. Early-phase clinical studies in heart failure populations suggest that PDE9A inhibitors are well tolerated and effectively augment cGMP levels, although dedicated trials in RHF are still needed. Overall, these findings indicate that targeting PDE9A may represent a promising therapeutic strategy to improve outcomes in RHF by directly addressing the molecular mechanisms underlying calcium mishandling and myocardial remodeling. Full article

Psoriasiform dermatitis refers to a spectrum of inflammatory skin disorders that resemble psoriasis both clinically and histologically. These conditions can occur idiopathically or as paradoxical reactions to biologic or targeted therapies, particularly in patients with atopic or autoimmune backgrounds. Histologic features often include acanthosis, parakeratosis, and lymphocytic infiltrates, but without the full molecular signature of classical psoriasis. This review provides an overview of psoriasiform dermatitis with a focus on its clinical presentation, differential diagnosis, and the immune pathways involved. Drug-induced forms, especially those triggered by anti-TNF agents, IL-4/IL-13 blockers, and JAK inhibitors, are highlighted due to their growing clinical relevance. We also summarize the main topical and systemic treatments, including corticosteroids, calcineurin inhibitors, PDE4 inhibitors, and JAK-STAT- or IL-23-targeted therapies. A better understanding of psoriasiform dermatitis is crucial to improve diagnosis and to guide treatment, especially in complex or refractory cases. Full article

PDE11A is a little-studied phosphodiesterase sub-family that breaks down cAMP/cGMP, with the PDE11A4 isoform enriched in the memory-related hippocampal formation. Age-related increases in PDE11A expression occur in human and rodent hippocampus and cause age-related cognitive decline of social memories. Interestingly, age-related increases in PDE11A4 protein ectopically accumulate in spherical clusters that group together in the brain to form linear filamentous patterns termed “PDE11A4 ghost axons”. The biophysical/physiochemical mechanisms underlying this age-related clustering are not known. Here, we determine if age-related clustering of PDE11A4 reflects liquid–liquid phase separation (LLPS; biomolecular condensation), and if PDE11A inhibitors can reverse this LLPS. We show human and mouse PDE11A4 exhibit several LLPS-promoting sequence features, including intrinsically disordered regions, non-covalent pi–pi interactions, and prion-like domains that were particularly enriched in the N-terminal regulatory region. Further, multiple bioinformatic tools predict PDE11A4 undergoes LLPS. Consistent with these predictions, aging-like PDE11A4 clusters in HT22 hippocampal neuronal cells were membraneless spherical droplets that progressively fuse over time in a concentration-dependent manner. Deletion of the N-terminal intrinsically disordered region prevented PDE11A4 LLPS despite equal protein expression between WT and mutant constructs. 1,6-hexanediol, along with tadalafil and BC11-38 that inhibit PDE11A4, reversed PDE11A4 LLPS in HT22 hippocampal neuronal cells. Interestingly, PDE11A4 inhibitors reverse PDE11A4 LLPS independently of increasing cAMP/cGMP levels via catalytic inhibition. Importantly, orally dosed tadalafil reduced PDE11A4 ghost axons in old mouse ventral hippocampus by 50%. Thus, PDE11A4 exhibits the four defining criteria of LLPS, and PDE11A inhibitors reverse this age-related phenotype both in vitro and in vivo. Full article

Two new racemic mixtures, including a polyketide, (±)-penilactone F (1), and a butenolide, (±) phenylbutyrolactone IIa (2), were isolated from the mangrove sediment-derived strain Aspergillus spelaeus SCSIO 41433. Additionally, 20 known compounds were isolated, including four penicillin-like compounds (11–14), three alkaloids (15–17), one sesquiterpene (18), and four phenolic acids (19–22). Their structures were elucidated through NMR spectroscopy, HRESIMS, X-ray diffraction, and ECD calculations. In the PDE4 inhibitory activity and anticancer cell activity assays, compounds 2, 3, 5, 8, 9, 11–14, and 16 exhibited weak PDE4 inhibitory activity at a concentration of 10 µM, Compound 11 demonstrated potent inhibitory effects against six cancer cell lines (MDA-MB-231, MDA-MB-435, HCT116, SNB-19, PC3, and A549), with IC₅₀ values ranging from 3.4 to 23.7 µM. Full article

The imbalance of phosphodiesterase 5 (PDE5) enzyme in the male body, or excessive PDE5 enzyme levels, can occur due to factors such as aging, diseases (e.g., cardiovascular disease, diabetes, depressive disorder), and physical behaviors (e.g., alcoholism, smoking, stress). PDE5 is directly associated with erectile dysfunction disease. Currently, many studies aim to find natural PDE5 inhibitors as an alternative to commercial drugs. This study is the first to demonstrate that the ethanolic leaf extract of D. cochinchinensis exhibits potent PDE5-inhibitory activity. The PDE5-inhibitory activity of five plant parts was evaluated: leaf (IC₅₀ = 1.53 ± 0.12 µg/mL), twig (3.37 ± 0.54), fruit (14.92 ± 2.85), heartwood (19.05 ± 5.60), and bark (16.03 ± 2.92). However, there is still uncertainty about which compounds in leaf extract are responsible for the PDE5 inhibition. Therefore, the purpose of this study is to identify the chemical constituents in the leaf of D. cochinchinensis, including determining which of these compounds may act as PDE5 inhibitors. This study was achieved using at-line LC-QTOF-MS². Full article

Phosphodiesterase 4 (PDE4) serves as a crucial regulator of cyclic adenosine monophosphate (cAMP) signaling and has been identified as a significant therapeutic target for inflammatory and metabolic disorders impacting the gastrointestinal (GI) tract and liver. Although pan-PDE4 inhibitors hold therapeutic promise, their clinical use has been constrained by dose-dependent adverse effects. Recent progress in the development of isoform-specific PDE4 inhibitors, such as those selective for PDE4B/D, alongside targeted delivery systems like liver-targeting nanoparticles and probiotic-derived vesicles, is reshaping the therapeutic landscape. This review consolidates the latest insights into PDE4 biology, highlighting how the structural characterization of isoforms informs drug design. We conduct a critical evaluation of preclinical and clinical data across various diseases, including inflammatory bowel diseases (IBDs), alcoholic liver disease, nonalcoholic fatty liver disease (NAFLD), liver fibrosis, and digestive tract tumors, with an emphasis on mechanisms extending beyond cAMP modulation, such as microbiota remodeling and immune reprogramming. Additionally, we address challenges in clinical translation, including biomarker discovery and the heterogeneity of trial outcomes, and propose a roadmap for future research directions. Full article