Search Results (343)

Arteriogenesis, the growth of pre-existing arterioles into functional collateral arteries, represents a key adaptive response to severe arterial stenosis. This process is driven by hemodynamic forces and a tightly coordinated inflammatory cascade. Here, we investigated the effects of pharmacological stimulation of the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) signaling pathway using the phosphodiesterase-5 (PDE5) inhibitor Sildenafil on collateral vessel growth in a murine model of femoral artery ligation (FAL). Flow cytometric analyses revealed that Sildenafil treatment significantly enhanced platelet–leukocyte aggregate formation, a prerequisite for the subsequent initiation of a localized perivascular inflammation. Histological and immunofluorescence analyses further demonstrated a marked increase in mast cell recruitment and degranulation at early time points (days 1 and 3 post-FAL). In addition, Sildenafil promoted perivascular macrophage accumulation on days 3 and 7, with a pronounced shift toward an M2-like pro-regenerative polarization state, ultimately resulting in the enhanced proliferation of vascular cells and the enlargement of collateral diameters. Together, these findings identify Sildenafil as a potent enhancer of arteriogenesis through coordinated immune cell activation, stimulating vascular cell proliferation along with positive collateral outward remodeling. Thus, Sildenafil emerges as a promising therapeutic candidate to promote collateral artery growth in cardiovascular occlusive diseases. Full article

Background/Objectives: Sexual dysfunction (SD) and broader sexual health problems are common after neurological disorders, yet interventional evidence is fragmented across conditions and outcomes. This umbrella review mapped and appraised systematic review-level evidence on interventions targeting SD and sexual health in neurological populations and qualified conclusions using certainty of evidence. Methods: PubMed, Web of Science, Cochrane Library, Embase, PsycINFO, EBSCOhost, and Scopus were searched from inception to 27 November 2025. Two reviewers screened records, extracted data, assessed review quality with AMSTAR 2, and rated certainty across intervention–outcome pairings using a GRADE-informed approach that integrated review confidence and primary-study risk-of-bias as reported by the source reviews. Results: Twenty-six systematic reviews were included. Overall confidence was frequently limited (17/26 critically low and 6/26 low), with only a small subset rated moderate or higher. Evidence was most coherent for phosphodiesterase type 5 (PDE5) inhibitors improving erectile function in men with spinal cord injury, whereas most other interventions and outcomes were supported by low or very low certainty. Women were represented in 16/26 reviews, yet validated female sexual function outcomes were synthesized in 6/26 reviews and relationship/couple outcomes in 3/26; furthermore, 10/26 reviews restricted inclusion to men, and no review synthesized pediatric intervention trials. Conclusions: Evidence supports PDE5 inhibitors for improving erectile function in men with spinal cord injury, while evidence for other interventions and sexual health domains remains limited. Methodological limitations highlight the need for more inclusive trials, broader standardized outcomes, and longer follow-up within neurorehabilitation pathways. Full article

Neurodegenerative diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and Huntington’s disease (HD) are characterized by complex pathologies with progressive neurodegeneration, protein misfolding, oxidative stress, and persistent inflammation. Recent findings indicate the pivotal involvement of epigenetic disruption, particularly aberrant histone deacetylase (HDAC) activity, in disease initiation and progression. In the current review, we systematically discuss the mechanistic function of HDACs across all classes (I, IIa, IIb, III, and IV) in neurodegenerative disease mechanisms, such as their involvement in the modulation of gene expression, mitochondrial function, proteostasis, and neuronal survival. We discuss the therapeutic potential, as well as limitations, of HDAC inhibitors (HDACis), such as pan-inhibitors and isoenzyme-selective inhibitors, and new multi-target-directed ligands with HDAC inhibition combined with acetylcholinesterase modulation, PDE modulation, MAO-B inhibition, or NMDAR modulation. Particular emphasis is placed on the development of HDAC6-selective inhibitors with enhanced brain permeability and reduced toxicity, which have shown promising preclinical efficacy in ameliorating hallmark pathologies of AD, PD, and HD. In addition, s-triazine-based scaffolds have recently emerged as promising chemotypes in HDAC inhibitor design, offering favorable pharmacokinetic profiles, metabolic stability, and the potential for dual-target modulation relevant to neurodegeneration. The review also explores the future of HDAC-targeted therapies, including PROTAC degraders, dual-inhibitor scaffolds, and sustainable, BBB-penetrant molecules. Collectively, this review underscores the importance of HDAC modulation as a multifaceted strategy in the treatment of neurodegenerative diseases and highlights the need for continued innovation in epigenetic drug design. Full article

Phosphodiesterase 4 (PDE4) is a key enzyme responsible for the hydrolysis of cyclic adenosine monophosphate (cAMP), thereby regulating essential signaling pathways involved in inflammation and immune modulation. Structural studies have demonstrated a high degree of conservation within the catalytic domains of PDE4 isoforms, accompanied by subtle conformational variations that underlie their selectivity and tissue-specific distribution. Elucidating these structural features has been instrumental in guiding the rational design of PDE4 inhibitors. Although synthetic PDE4 inhibitors such as roflumilast and apremilast exhibit significant therapeutic efficacy, their clinical application is often limited by dose-dependent adverse effects. These effects primarily arise from insufficient isoform selectivity, as current inhibitors tend to target multiple PDE4 subtypes indiscriminately, resulting in off-target pharmacological actions and reduced tolerability. In contrast, natural products—including flavonoids, terpenoids, and related polyphenolic compounds such as curcumin, α-mangostin, and their derivatives—have emerged as promising molecular scaffolds. Their lower toxicity, favorable biocompatibility, and structural diversity enable fine-tuning of potency and selectivity through rational modification. Integrating structural insights derived from crystallographic and computational studies with the optimization of natural compounds offers a sustainable and effective strategy for the development of safer, isoform-selective PDE4-targeted therapies. Full article

Background/Objectives: Alopecia areata (AA) is a common, noncicatricial autoimmune hair loss disorder characterized by relapsing inflammation and breakdown of hair follicle immune privilege. Increasing amounts of evidence suggest that pyroptosis, a lytic and inflammatory form of programmed cell death mediated by gasdermins and inflammasome activation, may play a role in AA pathogenesis. This review aims to synthesize current data on the molecular mechanisms linking inflammasome-driven pyroptosis with AA and to highlight emerging therapeutic opportunities. Methods: A comprehensive literature review was conducted focusing on mechanistic studies, ex vivo human scalp models, murine AA models, and interventional clinical data. A structured system of Levels of Evidence (LoE) and standardized nomenclature for experimental models was applied to ensure transparency in evaluating the role of pyroptosis and treatment strategies in AA. Results: Available evidence indicates that outer root sheath keratinocytes express functional inflammasome components, including NOD-like receptor family, pyrin domain containing 3 (NLRP3), adaptor-apoptosis-associated-speck-like protein (ASC), and caspase-1, and contribute to interleukin (IL)-1β release and pyroptotic cell death. Mitochondrial dysfunction, mediated by regulators such as PTEN and PINK1, amplifies NLRP3 activation and cytokine secretion, linking mitophagy impairment with follicular damage. Animal and human biopsy studies confirm increased inflammasome activity in AA lesions. Therapeutic approaches targeting pyroptosis include Janus kinase (JAK) inhibitors, biologics, Phosphodiesterase 4 (PDE4) inhibitors, mesenchymal stem cell therapy, natural compounds, and inflammasome inhibitors such as MCC950. While some agents demonstrated efficacy in clinical trials, most strategies remain at preclinical or early clinical stages. Conclusions: Pyroptosis represents a critical mechanism driving hair follicle structural and functional disruption and immune dysregulation in AA. By integrating evidence from molecular studies, disease models, and early clinical data, this review underscores the potential of targeting inflammasome-driven pyroptosis as a novel therapeutic strategy. Full article

Background: Erectile dysfunction (ED) affects approximately 20% of men worldwide, significantly affecting their quality of life. While phosphodiesterase type 5 inhibitors (PDE5-Is) are the standard first-line treatment, a substantial number of patients are non-responders. Second-line treatments, such as intracavernosal alprostadil, are effective but often limited by their invasive nature and the need for frequent injections. Intracavernosal onabotulinumtoxinA (BoNT-A) offers a promising new option. By inhibiting acetylcholine release and norepinephrine, as well as other neurotransmitters involved in detumescence, it facilitates cavernosal smooth muscle relaxation and enhances penile blood flow. Its effects may persist for up to six months following a single injection, potentially reducing treatment burden and improving adherence among men with refractory ED. Methods: A systematic review was performed in accordance with the PRISMA guidelines. Literature searches were conducted in PubMed, Embase, Cochrane Library, Scopus, and Clinicaltrials.gov from inception until August 2025 using a combination of keywords and MeSH terms related to ‘erectile dysfunction’ and ‘botulinum toxin’. After screening, 51 studies met the inclusion criteria. Due to significant heterogeneity in interventions (e.g., BoNT-A dosage, co-therapies), patient populations, and reported outcomes, the data were not suitable for meta-analysis. Consequently, a narrative synthesis was performed to summarize the findings. Results: Among the included studies, intracavernosal BoNT-A was associated with improvements in validated erectile function scores. Reported response rates, variably defined across studies, ranged from 40% to 77.5%. Several studies suggested that efficacy was higher in patients with mild-to-moderate ED and with repeated administration of 100 U doses. The treatment exhibited a favorable safety profile. The most common adverse event was mild, transient penile pain (reported incidence 1.5–6%). No studies reported serious systemic adverse events. The overall strength of the evidence was limited by significant heterogeneity among the included studies and their generally small sample sizes. Conclusions: Based on this systematic review, intracavernosal onabotulinumtoxinA (BoNT-A) may be a beneficial therapeutic option for patients with refractory ED, offering potential improvements in sexual function while reducing the need for invasive therapies. Future large-scale, placebo-controlled studies are essential to confirm these benefits and standardize their clinical application. Full article

Health wines are alcoholic beverages produced by infusing traditional liquors or rice wines with natural, medicinal, and food-safe ingredients. However, to accelerate efficacy, some manufacturers illegally adulterate health wines with phosphodiesterase type 5 (PDE-5) inhibitors, which may cause severe adverse effects. This study developed a method based on ultra-high-performance liquid chromatography–time-of-flight mass spectrometry (UPLC–TOF/MS) for the rapid screening and identification of 68 PDE-5 inhibitors illegally added to health wines. After optimizing the sample preparation procedure, chromatographic conditions, mass spectrometric parameters, and primary and secondary mass spectra of the 68 PDE-5 inhibitors were acquired as reference standards. Retention times and mass spectral data were imported into the Personal Compound Database and Library, establishing a high-resolution screening database with matched drug names, molecular formulas, and accurate molecular weights. A quantitative method was validated using 11 commonly adulterated compounds, including sildenafil. The response was highly linear (r ≥ 0.9988; 0.8–400 μg/L) with low detection limits (0.2–1.0 μg/L). The average spiked recoveries were 71.2–104.1%, with relative standard deviations of ≤10.1%. Among 59 commercial health wine samples, three batches tested positive for PDE-5 inhibitors (detection rate: 5.1%). The proposed method can assist market surveillance even when reference standards are unavailable for all compounds. Full article

Background: Several sarcoidosis patients require treatment with corticosteroids to prevent organ damage and control symptoms. However, corticosteroids are associated with numerous side effects and can be detrimental to patients if used long-term. Roflumilast is approved for the treatment of chronic obstructive pulmonary disease (COPD) and has been studied with positive results in patients with fibrosing sarcoidosis. Due to its mode of action, it targets proinflammatory and profibrotic pathways involved in sarcoidosis and could be a suitable medication for sarcoidosis. Methods: We retrospectively analyzed a cohort of 51 sarcoidosis patients treated with Roflumilast off-label between 2010 and 2020 at the Department of Pneumology, University Hospital Freiburg. Medical records, lung function, and laboratory results were reviewed. Results: Of the 51 patients, 33 patients received Roflumilast for at least 6 months, whereas 18 discontinued treatment, mostly due to mild to moderate gastrointestinal side effects (n = 7). No severe adverse events were observed. Patients on Roflumilast were less likely to have a decrease in FEV1 of more than 10% of their mean FEV1 compared to patients without Roflumilast (OR = 0.2; 95% CI 0.08–0.5). Escalation of therapy was documented in 49/97 (51%) of ambulatory visits for patients taking Roflumilast compared to 100/144 (69%) for patients without Roflumilast (OR = 0.45; 95% CI 0.26–0.76). Conclusions: Sarcoidosis patients receiving Roflumilast had less lung function loss and were less likely to require therapy escalation. Roflumilast could be a therapeutic option in sarcoidosis. Full article

In chronic obstructive pulmonary disease (COPD), dysregulated calcium homeostasis, oxidative stress, and mucus hypersecretion converge to suppress ciliary beat frequency (CBF), thereby compromising mucociliary clearance (MCC). These mechanisms are subject to pharmacological modulation. Long-acting muscarinic antagonists (LAMAs) exert direct cilia-stimulatory effects and may counteract pathogen-induced mucin overproduction without impairing clearance. Long-acting β₂-agonists (LABAs) enhance ciliary activity through the cAMP–PKA–dynein (cyclic adenosine monophosphate–protein kinase A–dynein) signalling pathway. Inhaled corticosteroids (ICSs), although largely neutral on CBF, provide indirect protection by suppressing IL-13–driven inflammation. Phosphodiesterase (PDE)-4 inhibitors sustain intracellular cAMP and promote ciliary motility, though their clinical use remains limited by adverse effects. Emerging evidence suggests that dual and triple therapies may provide additive or synergistic benefits for preserving mucociliary function. Clinically, ex vivo CBF interpretation may be influenced by ongoing pharmacotherapy and tissue sampling site. Nasal brush samples may predominantly reflect systemic rather than inhaled therapy. Moreover, differences in PDE isoform expression between nasal and bronchial epithelium further complicate direct extrapolation of results. Rigorous patient stratification by treatment regimen is therefore essential to reconcile inconsistencies reported across studies. Ultimately, preservation of MCC in COPD depends on a delicate balance between oxidative stress and pharmacological modulation of ciliary function. Full article

Matrix metalloproteinase-9 (MMP-9) is a zinc-dependent endopeptidase that plays a central role in extracellular matrix (ECM) remodeling, angiogenesis, immune cell trafficking, and cytokine activation. Dysregulated MMP-9 activity has been implicated in the pathogenesis of diverse conditions, including atherosclerosis, aneurysm formation, chronic obstructive pulmonary disease (COPD), asthma, neurodegeneration, and malignancy. Although broad-spectrum synthetic MMP inhibitors were initially developed as therapeutic agents, clinical trials failed due to lack of selectivity, poor tolerability, and impairment with physiological tissue repair. This outcome has shifted attention toward indirect pharmacological modulation of MMP-9 using drugs that are already approved for other indications. In this paper, we review the evidence supporting MMP-9 modulation by established therapeutics and adjunctive strategies. Cardiometabolic agents such as statins, angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), metformin, and pioglitazone reduce MMP-9 expression and enzymatic activity, contributing to vascular protection, improved insulin sensitivity, and attenuation of aneurysm progression. Anti-inflammatory and respiratory drugs, including glucocorticoids, phosphodiesterase-4 (PDE4) inhibitors, macrolide antibiotics, montelukast, and nonsteroidal anti-inflammatory drugs (NSAIDs), suppress MMP-9-driven airway inflammation and pathological tissue remodeling in asthma, COPD, and acute lung injury. Tetracycline derivatives, particularly sub-antimicrobial dose doxycycline, directly inhibit MMP-9 activity and are clinically validated in the treatment of periodontal disease and vascular remodeling. Hormone-related therapies such as rapamycin, estradiol, and tamoxifen exert tissue- and disease-specific effects on MMP-9 within endocrine and oncologic pathways. In parallel, nutritional interventions—most notably omega-3 polyunsaturated fatty acids and antioxidant vitamins—provide adjunctive strategies for mitigating MMP-9 activity in chronic inflammatory states. Taken together, these findings position MMP-9 as a modifiable and clinically relevant therapeutic target. The systematic integration of approved pharmacologic agents with lifestyle and nutritional interventions into disease-specific treatment paradigms may facilitate safer, context-specific modulation of MMP-9 activity and unveil novel opportunities for therapeutic repurposing. Full article

Pulmonary arterial hypertension (PAH) is a fatal disease with no cure. Until recently, most specific therapies for PAH had aimed at enhancing cyclic nucleotide (cAMP and cGMP) pathways, taking advantage of the vasorelaxant and antiproliferative properties of these key intracellular messengers. This process can be achieved by inhibiting phosphodiesterases (PDEs), which are intracellular enzymes responsible for cyclic nucleotide degradation. To date, only inhibitors of PDE type 5 (PDE5) have been approved for the treatment of PAH. Because the PDE superfamily comprises 11 families that encompass many variants, substantial experimental investigation has been conducted to assess the relevance of inhibiting other PDE families, aiming to offer therapeutic alternatives. This review synthesizes the main research work conducted on in vivo or ex vivo models, as well as on biological resources from patients. It helps provide evidence for the expression of PDE isoforms in the lung vasculature, as well as the efficacy and limitations of various pharmacological compounds tested for inhibiting pathological processes ongoing in the disease. Perspectives and suggestions for future research orientation are proposed. Full article

Introduction: Erectile dysfunction (ED) is strongly associated with metabolic and cardiovascular diseases and may serve as a marker of vascular pathology. Phosphodiesterase type 5 (PDE-5) inhibitors are the mainstay of treatment. Considering this link, cardiologists and internists might be expected to play a key role in therapy initiation. Purpose: This study evaluated prescription patterns of PDE-5 inhibitors in Poland, focusing on physician specialization and consultation type. Methods: We performed a retrospective analysis of electronic health records from over 300 outpatient clinics (2014–2024). Men >18 years with newly diagnosed ED were included. Data on the first prescriptions of sildenafil and tadalafil were assessed. Ethical approval was obtained. Results: A total of 11,998 patients were identified (mean age 42 years; mean BMI 26.54 kg/m²). Common comorbidities included hypercholesterolemia (67.0%), hypertension (58.5%), obesity (31.5%), and diabetes (12.4%). PDE-5 inhibitors (predominantly tadalafil (≈67%)) were prescribed in 71.5% of cases. Urologists accounted for 51.0% of prescriptions, sexologists 14.9%, internists 20.4%, and cardiologists only 0.10%. Treated patients were younger and had a lower BMI, fewer comorbidities, and more favorable metabolic profiles (all p < 0.05). Conclusions: Contrary to expectations, cardiologists and internists rarely initiate PDE-5 therapy. Prescribing is dominated by urologists despite high rates of cardiovascular comorbidities. A multidisciplinary approach incorporating metabolic and cardiovascular risk assessment is warranted. Full article

Highly selective inhibitors of the members of the cAMP-selective cyclic nucleotide phosphodiesterases, or PDE4 family, have shown clinically meaningful activity in two different classes of lung disease: roflumilast in obstructive lung disease, specifically chronic obstructive pulmonary disease (COPD), and nerandomilast in restrictive lung diseases characterized by inflammation/fibrosis of the alveolar interstitium, including idiopathic pulmonary fibrosis (IPF) and progressive pulmonary fibrosis (PPF). The beneficial therapeutic benefit of these agents in both of these disorders suggests that they share a common mechanism that underlies their effects on different pulmonary cells and tissues. This review outlines the biochemical, pharmacologic and cellular effects of PDE4-selective inhibitors, emphasizing their role in signal transduction pathways common to many pulmonary cell types. It then compares and contrasts the myriad cellular effects of these agents and their effects in pre-clinical animal models of these disorders. The emerging data are compatible with PDE4-selective inhibitors having targets of action in a large number of pulmonary cell types, only a subset of which is dysregulated in either COPD or IPF. This suggests that differences between the benefits observed with these individual agents in their various clinical indications reflect differences in disease pathogenesis, rather than proven differences in the enzyme-inhibitory effects of the various PDE4 inhibitors that have been studied to date. Full article

Background: Seborrheic dermatitis (SD) is a chronic, recurrent inflammatory dermatosis that primarily affects seborrheic areas such as the scalp, face, and upper trunk. Its etiology is multifactorial, involving sebaceous gland activity, immune dysregulation, skin barrier dysfunction, and alterations in the microbiome, particularly an overgrowth of Malassezia spp. Objective: This review provides an updated overview of the pathophysiological mechanisms of seborrheic dermatitis and critically examines current therapies and emerging treatments. Methods: A narrative review of the recent literature was conducted, including preclinical studies, clinical trials, and real-world evidence regarding SD pathogenesis and therapy. Special attention was paid to molecular pathways, microbiome-modulating strategies, and novel therapeutic agents. Results: Advances in transcriptomic and microbiome profiling have revealed a complex immunoinflammatory environment in SD, involving predominantly Th1, Th17, and Th22 axes. Conventional therapies are mainly based on antifungals, topical corticosteroids, and calcineurin inhibitors. However, new therapeutic approaches are under investigation, including PDE4 inhibitors (roflumilast, crisaborole, and apremilast), topical and oral JAK inhibitors, probiotics, and microbiome-targeted therapies. These agents offer promising results in selected patients, particularly those with refractory disease or facial involvement. Conclusions: SD remains a challenging condition due to its relapsing course and limited long-term therapeutic options. Emerging therapies represent a valuable opportunity to address unmet clinical needs, particularly in patients with severe, recurrent, or treatment-resistant forms. Full article

Autism spectrum disorder (ASD) and Fragile X syndrome (FXS) are neurodevelopmental disorders marked by deficits in communication and social interaction, often accompanied by anxiety, seizures, and intellectual disability. FXS, the most common monogenic cause of ASD, results from silencing of the FMR1 gene and consequent loss of FMRP, a regulator of synaptic protein synthesis. Disruptions in cyclic nucleotide (cAMP and cGMP) signaling underlie both ASD and FXS contributing to impaired neurodevelopment, synaptic plasticity, learning, and memory. Notably, reduced cAMP levels have been observed in platelets, lymphoblastoid cell lines and neural cells from FXS patients as well as Fmr1 KO and dfmr1 Drosophila models, linking FMRP deficiency to impaired cAMP regulation. Phosphodiesterase (PDE) inhibitors, which prevent the breakdown of cAMP and cGMP, have emerged as promising therapeutic candidates due to their ability to modulate neuronal signaling. Several PDE isoforms—including PDE2A, PDE4D, and PDE10A—have been implicated in ASD, and FXS, as they regulate pathways involved in synaptic plasticity, cognition, and social behavior. Preclinical and clinical studies show that PDE inhibition modulates neuroplasticity, neurogenesis, and neuroinflammation, thereby ameliorating autism-related behaviors. BPN14770 (a PDE4 inhibitor) has shown promising efficacy in FXS patients while cilostazol, pentoxifylline, resveratrol, and luteolin have showed improvements in children with ASD. However, challenges such as isoform-specific targeting, optimal therapeutic window, and timing of intervention remain. Collectively, these findings highlight PDE inhibition as a novel therapeutic avenue with the potential to restore cognitive and socio-behavioral functions in ASD and FXS, for which effective targeted treatments remain unavailable. Full article