Phosphodiesterase 4 Inhibitor Research Articles

Advances in attenuating opioid-induced respiratory depression: A narrative review.

Opioids exert analgesic effects by agonizing opioid receptors and activating signaling pathways coupled to receptors such as G-protein and/or β-arrestin. Concomitant respiratory depression (RD) is a common clinical problem, and improvement of RD is usually achieved with specific antagonists such as naloxone; however, naloxone antagonizes opioid analgesia and may produce more unknown adverse effects. In recent years, researchers have used various methods to isolate opioid receptor-mediated analgesia and RD, with the aim of preserving opioid analgesia while attenuating RD. At present, the focus is mainly on the development of new opioids with weak respiratory inhibition or the use of non-opioid drugs to stimulate breathing. This review reports recent advances in novel opioid agents, such as mixed opioid receptor agonists, peripheral selective opioid receptor agonists, opioid receptor splice variant agonists, biased opioid receptor agonists, and allosteric modulators of opioid receptors, as well as in non-opioid agents, such as AMPA receptor modulators, 5-hydroxytryptamine receptor agonists, phosphodiesterase-4 inhibitors, and nicotinic acetylcholine receptor agonists.

A Systematic Overview of Contraindications and Special Warnings for Biologic and Targeted Synthetic Disease Modifying Antirheumatic Drugs: Establishing a Framework to Create a "Safety Checklist".

The purpose of this review is to provide an overview of the contraindications, special warnings, and boxed warnings with the aim to establish a framework to create a prescription safety checklist for a class of drugs or disease indication. This study covers biologic disease modifying antirheumatic drugs (bDMARDs) and targeted synthetic DMARDs (tsDMARDs). We identified contraindications, boxed warnings, and special warnings provided by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA). The study included b/tsDMARDs approved for treating rheumatoid arthritis (RA), psoriatic arthritis (PsA), axial spondyloarthritis (SpA), and juvenile idiopathic arthritis (JIA) within the drug-classes anti-CD20, tumor necrosis factor inhibitors (TNFi), interleukin-1 inhibitors (IL-1i), cytotoxic T-lymphocyte-associated protein (CTLA) 4, interleukin-12/23 inhibitors (IL-12/23i), interleukin 6 receptor inhibitors (IL-6Ri), Janus kinase inhibitors (JAKi), phosphodiesterase 4 inhibitors (PDE4i), interleukin-17 inhibitors (IL-17i), and interleukin-23 inhibitors (IL-23i). All drug classes, except PDE4i, had contraindications and/or warnings related to infections, including tuberculosis. A warning about herpes zoster was listed for anti-CD20, IL-1i, IL-6Ri, and JAKi, while a warning about hepatitis reactivation was listed for anti-CD20, TNFi, IL-1i, CTLA4-Ig, IL-6Ri, and JAKi. Malignancy risk was mentioned for all drug classes except PDE4i, IL-17i, and IL-23i. Other warnings included demyelinating disease (TNFi, CTLA4-Ig, and IL-6Ri), heart failure (anti-CD20 and TNFi), major adverse cardiac events (JAKi and IL-12/23) and venous thromboembolism (JAKi), hyperlipidemia (IL-6Ri and JAKi), liver impairment (TNFi, IL-1i, IL-6Ri, and JAKi), kidney impairment (IL-1i, JAKi, and PDE4i), inflammatory bowel disease (IL-17i), gastrointestinal perforation (IL-6Ri, JAKi), cytopenia (anti-CD20, TNFi, IL-1i, IL-6Ri, JAKi), and depression (PDE4i). Contraindications and warnings appeared to increase with the passage of time since the drug's approval. This review provides an overview to establish the framework to create an easily accessible and actionable prescription safety checklist from individual medical product prescription information provided by regulatory medical authorities.

Lichen Planus: What is New in Diagnosis and Treatment?

Lichen planus (LP), an idiopathic, multifaceted chronic inflammatory disease with a heterogeneous clinical presentation, affects approximately 0.5-1% of the population. The various clinical manifestations of LP fall into three broad categories, namely cutaneous, appendageal, and mucosal, with further subclassification depending on the morphology and distribution patterns of individual lesions. There is mounting evidence that LP has systemic associations, including autoimmune conditions, glucose intolerance, dyslipidemia, and cardiovascular disorders. Cutaneous hypertrophic and mucosal forms of LP are at a heightened risk for malignant transformation. Familiarity with these potential associations in conjunction with long-term follow-up and regular screening could lead to a timely diagnosis and management of concomitant conditions. In addition, the frequent quality of life (QoL) impairment in LP underscores the need for a comprehensive approach including psychological evaluation and support. Several treatment strategies have been attempted, though most of them have not been adopted in clinical practice because of suboptimal benefit-to-risk ratios or lack of evidence. More recent studies toward pathogenesis-driven treatments have identified Janus kinase inhibitors such as tofacitinib, phosphodiesterase-4 inhibitors such as apremilast, and biologics targeting the interleukin-23/interleukin-17 pathway as novel therapeutic options, resulting in a dramatic change of the treatment landscape of LP. This contemporary review focuses on the diagnosis and management of LP, and places emphasis on more recently described targeted treatment options.

Lichen Planus: What is New in Diagnosis and Treatment?

Lichen planus (LP), an idiopathic, multifaceted chronic inflammatory disease with a heterogeneous clinical presentation, affects approximately 0.5-1% of the population. The various clinical manifestations of LP fall into three broad categories, namely cutaneous, appendageal, and mucosal, with further subclassification depending on the morphology and distribution patterns of individual lesions. There is mounting evidence that LP has systemic associations, including autoimmune conditions, glucose intolerance, dyslipidemia, and cardiovascular disorders. Cutaneous hypertrophic and mucosal forms of LP are at a heightened risk for malignant transformation. Familiarity with these potential associations in conjunction with long-term follow-up and regular screening could lead to a timely diagnosis and management of concomitant conditions. In addition, the frequent quality of life (QoL) impairment in LP underscores the need for a comprehensive approach including psychological evaluation and support. Several treatment strategies have been attempted, though most of them have not been adopted in clinical practice because of suboptimal benefit-to-risk ratios or lack of evidence. More recent studies toward pathogenesis-driven treatments have identified Janus kinase inhibitors such as tofacitinib, phosphodiesterase-4 inhibitors such as apremilast, and biologics targeting the interleukin-23/interleukin-17 pathway as novel therapeutic options, resulting in a dramatic change of the treatment landscape of LP. This contemporary review focuses on the diagnosis and management of LP, and places emphasis on more recently described targeted treatment options.

Inhibition of phosphodiesterase 4 attenuates aquaporin 4 expression and astrocyte swelling following cerebral ischemia/reperfusion injury.

We have previously shown that phosphodiesterase 4 (PDE4) inhibition protects against neuronal injury in rats following middle cerebral artery occlusion/reperfusion (MCAO/R). However, the effects of PDE4 on brain edema and astrocyte swelling are unknown. In this study, we showed that inhibition of PDE4 by Roflumilast (Roflu) reduced brain edema and brain water content in rats subjected to MCAO/R. Roflu decreased the expression of aquaporin 4 (AQP4), while the levels of phosphorylated protein kinase B (Akt) and forkhead box O3a (FoxO3a) were increased. In addition, Roflu reduced cell volume and the expression of AQP4 in primary astrocytes undergoing oxygen and glucose deprivation/reoxygenation (OGD/R). Consistently, PDE4B knockdown showed similar effects as PDE4 inhibition; and PDE4B overexpression rescued the inhibitory role of PDE4B knockdown on AQP4 expression. We then found that the effects of Roflu on the expression of AQP4 and cell volume were blocked by the Akt inhibitor MK2206. Since neuroinflammation and astrocyte activation are the common events that are observed in stroke, we treated primary astrocytes with interleukin-1β (IL-1β). Astrocytes treated with IL-1β showed decreased AQP4 and phosphorylated Akt and FoxO3a. Roflu significantly reduced AQP4 expression, which was accompanied by increased phosphorylation of Akt and FoxO3a. Furthermore, overexpression of FoxO3a partly reversed the effect of Roflu on AQP4 expression. Our findings suggest that PDE4 inhibition limits ischemia-induced brain edema and astrocyte swelling via the Akt/FoxO3a/AQP4 pathway. PDE4 is a promising target for the intervention of brain edema after cerebral ischemia.

Roflumilast ameliorates GAN diet-induced non-alcoholic fatty liver disease by reducing hepatic steatosis and fibrosis in ob/ob mice

Non-alcoholic fatty liver disease (NAFLD) is a highly prevalent progressive liver disease. Currently, there is only one drug for NAFLD treatment, and the options are limited. Phosphodiesterase-4 (PDE-4) inhibitors have potential in treating NAFLD. Therefore, this study aims to investigate the effect of roflumilast on NAFLD. Here, we fed ob/ob mice to induce the NAFLD model by GAN diet. Roflumilast (1 mg/kg) was administered orally once daily. Semaglutide (20 nmol/kg), used as a positive control, was injected subcutaneously once daily. Our findings showed that roflumilast has beneficial effects on NAFLD. Roflumilast prevented body weight gain and improved lipid metabolism in ob/ob-GAN NAFLD mice. In addition, roflumilast decreased hepatic steatosis by down-regulating the expression of hepatic fatty acid synthesis genes (SREBP1c, FASN, and CD36) and improving oxidative stress. Roflumilast not only reduced liver injury by decreasing serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, but also ameliorated hepatic inflammation by reducing the gene expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-6). Roflumilast lessened liver fibrosis by inhibiting the expression of fibrosis mRNA (TGFβ1, α-SMA, COL1a1, and TIMP-1). Collectively, roflumilast could ameliorate NAFLD, especially in reducing hepatic steatosis and fibrosis. Our findings suggested a PDE-4 inhibitor roflumilast could be a potential drug for NAFLD.

Sorbitol Destroyed Intestinal Microfold Cells (M Cells) Development through Inhibition of PDE4-Mediated RANKL Expression.

Microfold cells (M cells) are specific intestinal epithelial cells for monitoring and transcytosis of antigens, microorganisms, and pathogens in the intestine. However, the mechanism for M-cell development remained elusive. Real-time polymerase chain reaction, immunofluorescence, and western blotting were performed to analyze the effect of sorbitol-regulated M-cell differentiation in vivo and in vitro, and luciferase and chromatin Immunoprecipitation were used to reveal the mechanism through which sorbitol-modulated M-cell differentiation. Herein, in comparison to the mannitol group (control group), we found that intestinal M-cell development was inhibited in response to sorbitol treatment as evidenced by impaired enteroids accompanying with decreased early differentiation marker Annexin 5, Marcksl1, Spib, sox8, and mature M-cell marker glycoprotein 2 expression, which was attributed to downregulation of receptor activator of nuclear factor kappa-В ligand (RANKL) expression in vivo and in vitro. Mechanically, in the M-cell model, sorbitol stimulation caused a significant upregulation of phosphodiesterase 4 (PDE4) phosphorylation, leading to decreased protein kinase A (PKA)/cAMP-response element binding protein (CREB) activation, which further resulted in CREB retention in cytosolic and attenuated CREB binds to RANKL promoter to inhibit RANKL expression. Interestingly, endogenous PKA interacted with CREB, and this interaction was destroyed by sorbitol stimulation. Most importantly, inhibition of PDE4 by dipyridamole could rescue the inhibitory effect of sorbitol on intestinal enteroids and M-cell differentiation and mature in vivo and in vitro. These findings suggested that sorbitol suppressed intestinal enteroids and M-cell differentiation and matured through PDE4-mediated RANKL expression; targeting to inhibit PDE4 was sufficient to induce M-cell development.

An update on topical therapies for psoriasis.

Topical therapies are a mainstay of treatment for mild psoriasis and may be a useful adjunct in treatment of moderate-to-severe psoriasis. This review summarizes recent advances in topical therapies for psoriasis and currently available treatments. Topical aryl hydrocarbon receptor modulators (tapinarof) and topical phosphodiesterase-4 inhibitors (roflumilast) have been proven effective in randomized controlled trials for psoriasis. Although topical JAK inhibitors have also been studied, none are currently licensed for treatment of psoriasis. Topical corticosteroids and vitamin D analogues remain the most commonly used and widely available topical treatments for psoriasis. Cost may limit use of novel topical agents. Although the novel topical agents tapinarof and roflumilast are licensed for treatment of psoriasis by the FDA in the United States, they have not yet been licensed in Europe, and it remains to be seen whether they will be limited by cost.

Targeting phosphodiesterase 4 as a potential therapy for Parkinson's disease: a review.

Phosphodiesterases (PDEs) have become a promising therapeutic target for various disorders. PDEs are a vast and diversified family of enzymes that degrade cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), which have several biochemical and physiological functions. Phosphodiesterase 4 (PDE4) is the most abundant PDE in the central nervous system (CNS) and is extensively expressed in the mammalian brain, where it catalyzes the hydrolysis of intracellular cAMP. An alteration in the balance of PDE4 and cAMP results in the dysregulation of different biological mechanisms involved in neurodegenerative diseases. By inhibiting PDE4 with drugs, the levels of cAMP inside the cells could be stabilized, which may improve the symptoms of mental and neurological disorders such as memory loss, depression, and Parkinson's disease (PD). Though numerous studies have shown that phosphodiesterase 4 inhibitors (PDE4Is) are beneficial in PD, there are presently no approved PDE4I drugs for PD. This review presents an overview of PDE4Is and their effects on PD, their possible underlying mechanism in the restoration/protection of dopaminergic cell death, which holds promise for developing PDE4Is as a treatment strategy for PD. Methods on how these drugs could be effectively delivered to develop as a promising treatment for PD have been suggested.

Roflumilast foam (Zoryve) for seborrheic dermatitis.

The FDA has approved a 0.3% foam formulation of the phosphodiesterase-4 (PDE4) inhibitor roflumilast (Zoryve – Arcutis) for topical treatment of seborrheic dermatitis in patients ≥9 years old. Roflumilast is the first PDE4 inhibitor to be approved in the US for this indication.

Evaluation of preclinical efficacy of apremilast-loaded liquid crystalline nanoparticulate gel in amelioration of atopic dermatitis

Apremilast is a phosphodiesterase-4 inhibitor currently under investigation for managing atopic dermatitis, but it is associated with poor physicochemical properties, majorly affecting its bioavailability. To improve the topical delivery, we have encapsulated apremilast into the liquid crystalline nanoparticles and evaluated its preclinical efficacy against atopic dermatitis. The liquid crystalline nanoparticles were manufactured by the melt emulsification method followed by probe sonication. The prepared nanoparticles were evaluated for particle size, zeta potential, encapsulation efficiency and in vitro release. Further, the apremilast liquid crystalline nanoparticles were loaded into the gel base by magnetic stirring. The gel formulation was evaluated for viscosity, textural profile, drug content, ex vivo permeation, and retention in mice skin. The preclinical efficacy of optimized gel formulation was assessed in 2,4-dinitrochlorobenzene induced atopic dermatitis in mice model followed by histopathological examination of skin sections. The apremilast was successfully loaded into the liquid crystalline nanoparticles with an average particle size of 180 ± 0.45 nm and entrapment efficiency of 89.42 ± 4.27 %. The optimized nanoparticles were successfully loaded into gel base showing pseudoplastic shear thinning behaviour. In vivo preclinical efficacy of the optimized gel formulation revealed improved skin structure in comparison with negative control group. The histopathological examination of mice skin treated with optimized gel formulation resulted in decreased epidermal hyperplasia and intactness of outer keratinized epidermal layer with the inner layer. The outcomes of the apremilast-loaded liquid crystalline nanoparticulate gel demonstrated anti-atopic dermatitis potential.

Comprehensive Review on Phytoconstituents-based Nanomedicine for the Treatment of Atopic Dermatitis.

Atopic dermatitis (AD) is known as a chronic disease characterized by eczematous and pruritus skin lesions. The pathology behind atopic dermatitis etiology is loss of epidermal barrier, which prevents the production of protein filaggrin that can induce T-cell infiltration and inflammation. Treatment of AD is majorly based on limiting skin repair as well as reducing inflammation and itching. There are several remedies available for the treatment of AD, such as Janus kinase and calcineurin inhibitors, topical corticosteroids, and phosphodiesterase-4 inhibitors. The conventional formulations in the market have limited safety and efficacy. Hence, effective treatment of atopic dermatitis requires the development of novel, efficacious, reliable, and specific therapies. Recent research data have revealed that some naturally occurring medicinal plants have potential applications in the management of AD through different mechanisms. The nanotechnology-based therapeutics have gained a lot of attention in the last decade for the improvement in the activity of drugs having low absorption due to poor solubility, thus leading to lesser bioavailability. Therapies based on nanotechnology can be an effective way to overcome these obstacles. Due to their effective propensity to provide better drug diffusion and bioavailability as well as drug targeting potential at the desired site of action, these approaches may have decreased adverse drug effects, better penetration, and enhanced therapeutic efficacy. Hence, this review highlights the potential of phytoconstituents-based novel formulations for the treatment of atopic dermatitis. Furthermore, recent patents on therapeutic approaches to atopic dermatitis have also been briefly described.

A phosphodiesterase 4 (PDE4) inhibitor, amlexanox, reduces neuroinflammation and neuronal death after pilocarpine-induced seizure

Epilepsy, a complex neurological disorder, is characterized by recurrent seizures caused by aberrant electrical activity in the brain. Central to this study is the role of lysosomal dysfunction in epilepsy, which can lead to the accumulation of toxic substrates and impaired autophagy in neurons. Our focus is on phosphodiesterase-4 (PDE4), an enzyme that plays a crucial role in regulating intracellular cyclic adenosine monophosphate (cAMP) levels by converting it into adenosine monophosphate (AMP). In pathological states, including epilepsy, increased PDE4 activity contributes to a decrease in cAMP levels, which may exacerbate neuroinflammatory responses. We hypothesized that amlexanox, an anti-inflammatory drug and non-selective PDE4 inhibitor, could offer neuroprotection by addressing lysosomal dysfunction and mitigating neuroinflammation, ultimately preventing neuronal death in epileptic conditions. Our research utilized a pilocarpine-induced epilepsy animal model to investigate amlexanox's potential benefits. Administered intraperitoneally at a dose of 100 ​mg/kg daily following the onset of a seizure, we monitored its effects on lysosomal function, inflammation, neuronal death, and cognitive performance in the brain. Tissue samples from various brain regions were collected at predetermined intervals for a comprehensive analysis. The study's results were significant. Amlexanox effectively improved lysosomal function, which we attribute to the modulation of zinc's influx into the lysosomes, subsequently enhancing autophagic processes and decreasing the release of inflammatory factors. Notably, this led to the attenuation of neuronal death in the hippocampal region. Additionally, cognitive function, assessed through the modified neurological severity score (mNSS) and the Barnes maze test, showed substantial improvements after treatment with amlexanox. These promising outcomes indicate that amlexanox has potential as a therapeutic agent in the treatment of epilepsy and related brain disorders. Its ability to combat lysosomal dysfunction and neuroinflammation positions it as a potential neuroprotective intervention. While these findings are encouraging, further research and clinical trials are essential to fully explore and validate the therapeutic efficacy of amlexanox in epilepsy management.

Real-world efficacy of 2% crisaborole ointment on chronic hyperplasia lesions in 49 patients with atopic dermatitis.

Crisaborole, as a phosphodiesterase 4 (PDE4) inhibitor (PDE4i), effectively inhibits inflammatory pathways, showing promising results in atopic dermatitis (AD), particularly in chronic hyperplasia lesions. Based on real-world data from China, this study assesses the effectiveness and safety of 2% PDE4i ointment as monotherapy for chronic hyperplastic AD lesions. A total of 49 AD patients aged 12 and above with chronic hyperplastic lesions and Investigator's Static Global Assessment scores of mild or moderate were enrolled. They received 2% PDE4i ointment twice daily until the lesions completely cleared. The effectiveness endpoints comprised the onset time of pruritus and lesion remission and the time of complete lesion clearance. PDE4i demonstrated high effectiveness with minimal irritation, notable improvement in hyperpigmentation, and early remission of pruritus and lesions. The response varied across age groups; elderly patients experienced quicker pruritus relief compared to adolescents and adults, while adolescents showed earlier lesion remission by about 3 days. No significant difference was observed across age groups in the time for complete lesion clearance. Additionally, AD duration (less or more than 3 years) did not significantly impact pruritus or lesion remission. PDE4i monotherapy is effective and safe for chronic hyperplasia lesions in AD across all age groups, and its effectiveness appears to be independent of AD duration.

Functional rescue of CFTR in rectal organoids from patients carrying R334W variant by CFTR modulators and PDE4 inhibitor Roflumilast

BackgroundMany disease-causing variants in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene remain uncharacterized and untreated. Restoring the function of the impaired CFTR protein is the goal of personalized medicine, particularly in patients carrying rare CFTR variants. In this study, functional defects related to the rare R334W variant were evaluated after treatment with CFTR modulators or Roflumilast, a phosphodiesterase-4 inhibitor (PDE4i). MethodsRectal organoids from subjects with R334W/2184insA and R334W/2183AA > G genotypes were used to perform the Forskolin-induced swelling (FIS) assay. Organoids were left drug-untreated or treated with modulators VX-770 (I), VX-445 (E), and VX-661 (T) mixed, and their combination (ETI). Roflumilast (R) was used alone or as a combination of I + R. ResultsOur data show a significant increase in FIS rate following treatment with I alone. The combined use of modulators, such as ETI, did not increase further swelling than I alone, nor in protein maturation. Treatment with R shows an increase in FIS response similar to those of I, and the combination R + I significantly increases the rescue of CFTR activity. ConclusionsEquivalent I and ETI treatment efficacy was observed for both genotypes. Furthermore, significant organoid swelling was observed with combined I + R used that supports the recently published data describing a potentiating effect of only I in patients carrying the variant R334W and, at the same time, corroborating the role of strategies that include PDE4 inhibitors further to potentiate the effect of I for this variant.

A Narrative Review of Current and Emerging Trends in the Treatment of Alcohol Use Disorder.

Alcohol use disorder (AUD) is a significant contributor to morbidity and mortality in the United States. It contributes to over 140,000 annual deaths, to over 200 related diseases and health conditions globally, and accounts for 5.1% of the global disease burden. Despite its substantial impact, AUD remains undertreated, marked by a scarcity of approved medications. This paper explores the current treatment landscape and novel strategies for both alcohol withdrawal syndrome and AUD. Promising results, including the use of psychedelics alongside psychotherapy, noninvasive neural-circuit-based interventions, phosphodiesterase-4 inhibitors, and GLP-1 receptor agonists, have emerged from recent studies. While these advancements show potential, further research is crucial for a comprehensive understanding of their effectiveness. The clear shortage of approved medications and other treatment modalities underscores the pressing need for ongoing research.

Full Guidelines—From the Medical Board of the National Psoriasis Foundation: Perioperative management of systemic immunomodulatory agents in patients with psoriasis and psoriatic arthritis

BackgroundSystemic immunomodulatory agents are indicated in the treatment of moderate-to-severe plaque psoriasis and psoriatic arthritis. Perioperative use of these medications may increase the risk of surgical site infection and complication. ObjectiveTo evaluate the risk of surgical site infection and complication in patients with chronic autoimmune inflammatory disease receiving immunomodulatory agents (tumor necrosis factor-alpha inhibitors, interleukin [IL]-12/23 inhibitor, IL-17 inhibitors, IL-23 inhibitors, cytotoxic T-lymphocyte–associated antigen-4 co-stimulator, phosphodiesterase-4 inhibitor, Janus kinase inhibitors, tyrosine kinase 2 inhibitor, cyclosporine, and methotrexate) undergoing surgery. MethodsWe performed a search of the MEDLINE PubMed database of patients with chronic autoimmune inflammatory disease on immune therapy undergoing surgery. ResultsWe examined 48 new or previously unreviewed studies; the majority were retrospective studies in patients with rheumatoid arthritis and inflammatory bowel disease. ConclusionFor low-risk procedures, TNF-alpha inhibitors, IL-17 inhibitors, IL-23 inhibitors, ustekinumab, abatacept, methotrexate, cyclosporine, and apremilast can safely be continued. For intermediate- and high-risk surgery, methotrexate, cyclosporine, apremilast, abatacept, IL-17 inhibitors, IL-23 inhibitors, and ustekinumab are likely safe to continue; however, a case-by-case approach is advised. Acitretin can be continued for any surgery. There is insufficient evidence to make firm recommendations on tofacitinib, upadacitinib, and deucravacitinib.

Effects on Lipid Profile after One Year of Apremilast Therapy in Patients with Psoriasis: A Monocentric Experience.

Apremilast, a phosphodiesterase-4 inhibitor, has shown promise to have a potential beneficial metabolic effect. We conducted a single-centre retrospective study on adult patients with moderate-to-severe psoriasis who underwent apremilast treatment over at least 12 and 52 weeks, respectively. Baseline characteristics, weight, lipid profile, and fasting glucose levels were collected at baseline and at 12, 24, and 52 weeks. Furthermore, we conducted a narrative review of the current scientific knowledge on the metabolic effects of apremilast in patients with psoriasis and psoriatic arthritis. We observed a significant reduction in average weight and body mass index (BMI) in patients treated with apremilast in both the initial and the subgroup analysis, a significant reduction in triglycerides levels at 24 and 52 weeks, and a significant increase in high-density lipoprotein (HDL) levels at 52 weeks, whereas there were no significant changes in total cholesterol or low-density lipoprotein (LDL) concentrations over the 52-week treatment period. These findings suggest a potential positive impact of apremilast on both weight management and lipid profile in individuals with moderate-to-severe psoriasis in the medium-long term.

The PDE4 Inhibitors Roflumilast and Rolipram Rescue ADO2 Osteoclast Resorption Dysfunction.

Autosomal Dominant Osteopetrosis type II (ADO2) is a rare bone disease of impaired osteoclastic bone resorption caused by heterozygous missense mutations in the chloride channel 7 (CLCN7). Adenylate cyclase, which catalyzes the formation of cAMP, is critical for lysosomal acidification in osteoclasts. We found reduced cAMP levels in ADO2 osteoclasts compared to wild-type (WT) osteoclasts, leading us to examine whether regulating cAMP would improve ADO2 osteoclast activity. Although forskolin, a known activator of adenylate cyclase and cAMP levels, negatively affected osteoclast number, it led to an overall increase in ADO2 and WT osteoclast resorption activity in vitro. Next, we examined cAMP hydrolysis by the phosphodiesterase 4 (PDE4) proteins in ADO2 versus WT osteoclasts. QPCR analysis revealed higher expression of the three major PDE4 subtypes (4a, 4b, 4d) in ADO2 osteoclasts compared in WT, consistent with reduced cAMP levels in ADO2 osteoclasts. In addition, we found that the PDE4 antagonists, rolipram and roflumilast, stimulated ADO2 and WT osteoclast formation in a dose-dependent manner. Importantly, roflumilast and rolipram displayed a concentration-dependent increase in osteoclast resorption activity which was greater in ADO2 than WT osteoclasts. Moreover, treatment with roflumilast rescued cAMP levels in ADO2 OCLs. The key findings from our studies demonstrate that osteoclasts from ADO2 mice exhibit reduced cAMP levels and PDE4 inhibition rescues cAMP levels and ADO2 osteoclast activity dysfunction in vitro. The mechanism of action of PDE4 inhibitors and their ability to reduce the high bone mass of ADO2 mice in vivo are currently under investigation. Importantly, these studies advance the understanding of the mechanisms underlying the ADO2 osteoclast dysfunction which is critical for the development of therapeutic approaches to treat clinically affected ADO2 patients.

Crosstalk between purinergic receptor P2Y11 and chemokine receptor CXCR7 is regulated by CXCR4 in human macrophages

P2Y11 is a G protein-coupled ATP receptor that activates IL-1 receptor (IL-1R) in a cyclic AMP dependent manner. In human macrophages, P2Y11/IL-1R crosstalk with CCL20 as a prime target is controlled by phosphodiesterase 4 (PDE4), which mediates breakdown of cyclic AMP. Here, we used gene expression analysis to identify activation of CXCR4 and CXCR7 as a hallmark of P2Y11 signaling. We found that PDE4 inhibition with rolipram boosts P2Y11/IL-1R-induced upregulation of CXCR7 expression and CCL20 production in an epidermal growth factor receptor dependent manner. Using an astrocytoma cell line, naturally expressing CXCR7 but lacking CXCR4, P2Y11/IL-1R activation effectively induced and CXCR7 agonist TC14012 enhanced CCL20 production even in the absence of PDE4 inhibition. Moreover, CXCR7 depletion by RNA interference suppressed CCL20 production. In macrophages, the simultaneous activation of P2Y11 and CXCR7 by their respective agonists was sufficient to induce CCL20 production with no need of PDE4 inhibition, as CXCR7 activation increased its own and eliminated CXCR4 expression. Finally, analysis of multiple CCL chemokines in the macrophage secretome revealed that CXCR4 inactivation and CXCR7 activation selectively enhanced P2Y11/IL-1R-mediated secretion of CCL20. Altogether, our data establish CXCR7 as an integral component of the P2Y11/IL-1R-initiated signaling cascade and CXCR4-associated PDE4 as a regulatory checkpoint.