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Introduction: Severe recurrent aphthous stomatitis (RAS) represents a therapeutic challenge because of its impact on the patient's quality of life. Additionally, no approved systemic therapies are available. Roflumilast, a phosphodiesterase‐4 inhibitor, has shown promise in other inflammatory dermatological conditions. This study aimed to assess the characteristics, effectiveness, and safety of roflumilast in treating RAS in routine clinical practice. Methods: This is a single cohort ambispective observational study conducted in five Spanish centers. Twenty‐two patients with RAS treated with roflumilast participated. Data collection included demographic, clinical, and outcome variables. Statistical analysis compared the outcomes of 12 weeks of roflumilast treatment with a similar prior period without treatment. Results: During treatment with roflumilast, a significant reduction in flare‐ups (88%) and oral ulcers (94%) was observed compared to the untreated period. A reduction in pain (66%) and ulcer duration (63%) was observed. Adverse effects (AEs) occurred in 13 patients, predominantly headache and gastrointestinal disturbances. Most of these were self‐limiting or manageable with dose adjustment. Treatment was withdrawn in three cases, mainly because of AEs. Conclusions: This study suggests that roflumilast may effectively treat RAS by reducing the number of flare‐ups and ulcers, their duration, and the symptomatology produced by the ulcers. In addition, roflumilast has a good safety profile, is well tolerated at low doses, and does not require close monitoring. These characteristics and its favorable economic profile make roflumilast a promising therapeutic option in this pathology. [ABSTRACT FROM AUTHOR]

Abstract Background Epidermal remodeling and hypertrophy are hallmarks of skin fibrotic disorders, and keratinocyte to mesenchymal (EMT)-like transformations drive epidermis alteration in skin fibrosis such as keloids and hypertrophic scars (HTS). While phosphodiesterase 4 (PDE4) inhibitors have shown effectiveness in various fibrotic disorders, their role in skin fibrosis is not fully understood. This study aimed to explore the specific role of PDE4B in epidermal remodeling and hypertrophy seen in skin fibrosis. Methods In vitro experiments examined the effects of inhibiting PDE4A-D (with Roflumilast) or PDE4B (with siRNA) on TGFβ1-induced EMT differentiation and dedifferentiation in human 3D epidermis. In vivo studies investigated the impact of PDE4 inhibition on HOCl-induced skin fibrosis and epidermal hypertrophy in mice, employing both preventive and therapeutic approaches. Results The study found increased levels of PDE4B (mRNA, protein) in keloids > HTS compared to healthy epidermis, as well as in TGFβ-stimulated 3D epidermis. Keloids and HTS epidermis exhibited elevated levels of collagen Iα1, fibronectin, αSMA, N-cadherin, and NOX4 mRNA, along with decreased levels of E-cadherin and ZO-1, confirming an EMT process. Inhibition of both PDE4A-D and PDE4B prevented TGFβ1-induced Smad3 and ERK1/2 phosphorylation and mesenchymal differentiation in vitro. PDE4A-D inhibition also promoted mesenchymal dedifferentiation and reduced TGFβ1-induced ROS and keratinocyte senescence by rescuing PPM1A, a Smad3 phosphatase. In vivo, PDE4 inhibition mitigated HOCl-induced epidermal hypertrophy in mice in both preventive and therapeutic settings. Conclusions Overall, the study supports the potential of PDE4 inhibitors, particularly PDE4B, in treating skin fibrosis, including keloids and HTS, shedding light on their functional role in this condition.

Introduction: Overwhelming neutrophil activation and oxidative stress significantly contribute to acute respiratory distress syndrome (ARDS) pathogenesis. However, the potential of repurposing ribociclib, a cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor used clinically in cancer treatment, for treating neutrophilic ARDS remains uncertain. This study illustrated the ability and underlying mechanism of ribociclib for treating ARDS and neutrophilic inflammation. Methods: Primary human neutrophils were used to determine the therapeutic effects of ribociclib on respiratory bursts, chemotactic responses, and inflammatory signaling. In vitro and silico analyses were performed to determine the underlying molecular mechanisms. The potential of ribociclib repurposing was evaluated using an in vivo ARDS model in lipopolysaccharide (LPS)-primed mice. Results: We found that treatment using ribociclib markedly limited overabundant oxidative stress (reactive oxygen species [ROS]) production and chemotactic responses (integrin levels and adhesion) in activated human neutrophils. Ribociclib was also shown to act as a selective inhibitor of phosphodiesterase 4 (PDE4), thereby promoting the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway, leading to the inhibition of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) phosphorylation, and calcium influx. Notably, prophylactic administration and post-treatment with ribociclib ameliorated neutrophil infiltration, lung inflammation, accumulation of oxidative stress, pulmonary destruction, and mortality in mice with LPS-induced ARDS. Conclusion: We demonstrated for the first time that ribociclib serves as a novel PDE4 inhibitor for treating neutrophilic inflammation and ARDS. The repurposing ribociclib and targeting neutrophilic PDE4 offer a potential off-label alternative for treating lung lesions and other inflammatory conditions.

Background: Epidermal remodeling and hypertrophy are hallmarks of skin fibrotic disorders, and keratinocyte to mesenchymal (EMT)-like transformations drive epidermis alteration in skin fibrosis such as keloids and hypertrophic scars (HTS). While phosphodiesterase 4 (PDE4) inhibitors have shown effectiveness in various fibrotic disorders, their role in skin fibrosis is not fully understood. This study aimed to explore the specific role of PDE4B in epidermal remodeling and hypertrophy seen in skin fibrosis. Methods: In vitro experiments examined the effects of inhibiting PDE4A-D (with Roflumilast) or PDE4B (with siRNA) on TGFβ1-induced EMT differentiation and dedifferentiation in human 3D epidermis. In vivo studies investigated the impact of PDE4 inhibition on HOCl-induced skin fibrosis and epidermal hypertrophy in mice, employing both preventive and therapeutic approaches. Results: The study found increased levels of PDE4B (mRNA, protein) in keloids > HTS compared to healthy epidermis, as well as in TGFβ-stimulated 3D epidermis. Keloids and HTS epidermis exhibited elevated levels of collagen Iα1, fibronectin, αSMA, N-cadherin, and NOX4 mRNA, along with decreased levels of E-cadherin and ZO-1, confirming an EMT process. Inhibition of both PDE4A-D and PDE4B prevented TGFβ1-induced Smad3 and ERK1/2 phosphorylation and mesenchymal differentiation in vitro. PDE4A-D inhibition also promoted mesenchymal dedifferentiation and reduced TGFβ1-induced ROS and keratinocyte senescence by rescuing PPM1A, a Smad3 phosphatase. In vivo, PDE4 inhibition mitigated HOCl-induced epidermal hypertrophy in mice in both preventive and therapeutic settings. Conclusions: Overall, the study supports the potential of PDE4 inhibitors, particularly PDE4B, in treating skin fibrosis, including keloids and HTS, shedding light on their functional role in this condition. [ABSTRACT FROM AUTHOR]

[Display omitted] • Neutrophilic inflammation is a critical pathogenic hallmark in ARDS. • Ribociclib, a clinically-used CDK4/6 inhibitor, acts as a novel PDE4 inhibitor to regulate neutrophilic inflammation. • Ribociclib shows therapeutic potential in ARDS. • The drug repurposing of ribociclib provides a promising opportunity for neutrophil-associated diseases, including ARDS. Overwhelming neutrophil activation and oxidative stress significantly contribute to acute respiratory distress syndrome (ARDS) pathogenesis. However, the potential of repurposing ribociclib, a cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor used clinically in cancer treatment, for treating neutrophilic ARDS remains uncertain. This study illustrated the ability and underlying mechanism of ribociclib for treating ARDS and neutrophilic inflammation. Primary human neutrophils were used to determine the therapeutic effects of ribociclib on respiratory bursts, chemotactic responses, and inflammatory signaling. In vitro and silico analyses were performed to determine the underlying molecular mechanisms. The potential of ribociclib repurposing was evaluated using an in vivo ARDS model in lipopolysaccharide (LPS)-primed mice. We found that treatment using ribociclib markedly limited overabundant oxidative stress (reactive oxygen species [ROS]) production and chemotactic responses (integrin levels and adhesion) in activated human neutrophils. Ribociclib was also shown to act as a selective inhibitor of phosphodiesterase 4 (PDE4), thereby promoting the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway, leading to the inhibition of extracellular signal-regulated kinase (ERK), c-Jun N -terminal kinase (JNK) phosphorylation, and calcium influx. Notably, prophylactic administration and post-treatment with ribociclib ameliorated neutrophil infiltration, lung inflammation, accumulation of oxidative stress, pulmonary destruction, and mortality in mice with LPS-induced ARDS. We demonstrated for the first time that ribociclib serves as a novel PDE4 inhibitor for treating neutrophilic inflammation and ARDS. The repurposing ribociclib and targeting neutrophilic PDE4 offer a potential off-label alternative for treating lung lesions and other inflammatory conditions. [ABSTRACT FROM AUTHOR]

Difamilast, a phosphodiesterase 4 (PDE4) inhibitor, has been shown to be effective in the treatment of atopic dermatitis (AD), although the mechanism involved remains unclear. Since IL-33 plays an important role in the pathogenesis of AD, we investigated the effect of difamilast on IL-33 activity. Since an in vitro model of cultured normal human epidermal keratinocytes (NHEKs) has been utilized to evaluate the pharmacological potential of adjunctive treatment of AD, we treated NHEKs with difamilast and analyzed the expression of the suppression of tumorigenicity 2 protein (ST2), an IL-33 receptor with transmembrane (ST2L) and soluble (sST2) isoforms. Difamilast treatment increased mRNA and protein levels of sST2, a decoy receptor suppressing IL-33 signal transduction, without affecting ST2L expression. Furthermore, supernatants from difamilast-treated NHEKs inhibited IL-33-induced upregulation of TNF-α, IL-5, and IL-13 in KU812 cells, a basophil cell line sensitive to IL-33. We also found that difamilast activated the aryl hydrocarbon receptor (AHR)–nuclear factor erythroid 2-related factor 2 (NRF2) axis. Additionally, the knockdown of AHR or NRF2 abolished the difamilast-induced sST2 production. These results indicate that difamilast treatment produces sST2 via the AHR–NRF2 axis, contributing to improving AD symptoms by inhibiting IL-33 activity. [ABSTRACT FROM AUTHOR]

Phosphodiesterase 4 (PDE4) inhibitors are effective therapeutic agents for various inflammatory diseases. Roflumilast, apremilast, and crisaborole have been developed and approved for the treatment of chronic obstructive pulmonary disease psoriatic arthritis, and atopic dermatitis. Inflammation underlies many vascular diseases, yet the role of PDE4 inhibitors in these diseases remains inadequately explored. This review elucidates the clinical applications and anti-inflammatory mechanisms of PDE4 inhibitors, as well as their potential protective effects on vascular diseases. Additionally, strategies to mitigate the adverse reactions of PDE4 inhibitors are discussed. This article emphasizes the need for further exploration of the therapeutic potential and clinical applications of PDE4 inhibitors in vascular diseases. [ABSTRACT FROM AUTHOR]

Spinal cord injury (SCI) is a life-changing event that severely impacts the patient's quality of life. Modulating neuroinflammation, which exacerbates the primary injury, and stimulating neuro-regenerative repair mechanisms are key strategies to improve functional recovery. Cyclic adenosine monophosphate (cAMP) is a second messenger crucially involved in both processes. Following SCI, intracellular levels of cAMP are known to decrease over time. Therefore, preventing cAMP degradation represents a promising strategy to suppress inflammation while stimulating regeneration. Intracellular cAMP levels are controlled by its hydrolyzing enzymes phosphodiesterases (PDEs). The PDE4 family is most abundantly expressed in the central nervous system (CNS) and its inhibition has been shown to be therapeutically relevant for managing SCI pathology. Unfortunately, the use of full PDE4 inhibitors at therapeutic doses is associated with severe emetic side effects, hampering their translation toward clinical applications. Therefore, in this study, we evaluated the effect of inhibiting specific PDE4 subtypes (PDE4B and PDE4D) on inflammatory and regenerative processes following SCI, as inhibitors selective for these subtypes have been demonstrated to be well-tolerated. We reveal that administration of the PDE4D inhibitor Gebr32a, even when starting 2 dpi, but not the PDE4B inhibitor A33, improved functional as well as histopathological outcomes after SCI, comparable to results obtained with the full PDE4 inhibitor roflumilast. Furthermore, using a luminescent human iPSC-derived neurospheroid model, we show that PDE4D inhibition stabilizes neural viability by preventing apoptosis and stimulating neuronal differentiation. These findings strongly suggest that specific PDE4D inhibition offers a novel therapeutic approach for SCI.

Abstract Thyroid carcinoma (THCA) is the most common endocrine cancer. Phosphodiesterase (PDE) 4 enzyme family, as specific regulator of cyclic adenosine monophosphate, may play a important role in THCA. However, few studies on PDE4 enzyme family in THCA have been reported yet. Therefore, this study aimed to systematically analyze the changes of PDE4 enzyme family in THCA, and look for potential target for THCA therapy. We systematically analyzed the expression differences, prognostic value, genetic alteration, methylation modification, and the correlation with tumor immune microenvironment of PDE4 family in THCA using several public databases, including TCGA, GEO, GSCA, TNMplot, cBioPortal, DiseaseMeth and TIMER. Besides, functional enrichment analysis and protein–protein interaction (PPI) network of PDE4 family was investigated using Metascape and STRING databases. The expression levels of PDE4A, PDE4B and PDE4D were down-regulated in THCA patients at different cancer stages, while the expression level of PDE4C was significantly up-regulated. Moreover, THCA patients with higher PDE4C expression had shorter progress free survival compared with those with lower PDE4C expression. The low genomic alteration frequencies and mildly increased methylation levels of PDE4 family were found in THCA patients. Except for PDE4A, the expression levels of PDE4B, PDE4C and PDE4D could affect many immune cells infiltration during THCA progression. Four PDE4 subtypes were all enriched in cAMP catabolic process. Nevertheless, PDE4C was not enriched in the cAMP binding signal pathway, and PDE4B was not enriched in the G alphas signaling events. Notably, PDE4C participated in cAMP metabolic process by regulating adenylate cyclases (ADCYs), which involved ADCY1, ADCY5, ADCY6, ADCY8 and ADCY9. The findings of this study provide a partial basis for the role of PDE4 family in the occurrence and development of THCA. In addition, this study also suggested that PDE4C might be a potential prognostic marker of THCA, which could serve as a reference for future basic and clinical research.

Abstract Background Research into the neurobiological underpinnings of learning and memory has demonstrated the cognitive-enhancing effects associated with diverse classes of phosphodiesterase (PDE) inhibitors. Specific PDE inhibitors have been identified to improve neuronal communication through selective inhibition of PDE activity. Roflumilast, a PDE4 inhibitor, has demonstrated efficacy in enhancing episodic memory in healthy adults and elderly participants with pronounced memory impairment, indicative of amnestic mild cognitive impairment (aMCI). In alignment with these findings, the present protocol aims to provide a proof of concept phase II of the potential of roflumilast to aid patients diagnosed with (a)MCI or mild Alzheimer’s disease (AD) dementia. Methods The study will be conducted according to a double-blind, randomized placebo-controlled, between-subjects design. Participants with (a)MCI and mild AD dementia will be recruited through the Memory Clinic at the Maastricht University Medical Centre + (MUMC +) in Maastricht, the Netherlands, alongside outreach through regional hospitals, and social media. The study will have three arms: placebo, 50 μg roflumilast, and 100 μg roflumilast, with a treatment duration of 24 weeks. The primary outcome measure will focus on the assessment of episodic memory, as evaluated through participants’ performance on the 15-word Verbal Learning Task (VLT). Our secondary objectives are multifaceted, including an exploration of various cognitive domains. In addition, insights into the well-being and daily functioning of participants will be investigated through interviews with both the participants and their (informal) caregivers, we are interested in the well-being and daily functioning of the participants. Discussion The outcomes of the present study aim to elucidate the significance of the PDE4 inhibition mechanism as a prospective therapeutic target for enhancing cognitive function in individuals with (a)MCI and mild AD dementia. Identifying positive effects within these patient cohorts could extend the relevance of this treatment to encompass a broader spectrum of neurological disorders. Trial registration The Medical Ethics Committee of MUMC + granted ethics approval for the 4th version of the protocol on September 10th, 2020. The trial was registered at the European Drug Regulatory Affairs Clinical Trials (EudraCT) registered on the 19th of December 2019 ( https://www.clinicaltrialsregister.eu/ctr-search/trial/2019-004959-36/NL ) and ClinicalTrial.gov (NCT04658654, https://clinicaltrials.gov/study/NCT04658654?intr=roflumilast&cond=mci&rank=1 ) on the 8th of December 2020. The Central Committee on Research Involving Human Subjects (CCMO) granted approval on the 30th of September 2020.

Activation and transdifferentiation of hepatic stellate cells (HSC) into migratory myofibroblasts is a key process in liver fibrogenesis. Cell migration requires an active remodeling of the cytoskeleton, which is a tightly regulated process coordinated by Rho‐specific guanine nucleotide exchange factors (GEFs) and the Rho family of small GTPases. Rho‐associated kinase (ROCK) promotes assembly of focal adhesions and actin stress fibers by regulating cytoskeleton organization. GEF exchange protein directly activated by cAMP 1 (EPAC1) has been implicated in modulating TGFβ1 and Rho signaling; however, its role in HSC migration has never been examined. The aim of this study was to evaluate the role of cAMP‐degrading phosphodiesterase 4 (PDE4) enzymes in regulating EPAC1 signaling, HSC migration, and fibrogenesis. We show that PDE4 protein expression is increased in activated HSCs expressing alpha smooth muscle actin and active myosin light chain (MLC) in fibrotic tissues of human nonalcoholic steatohepatitis cirrhosis livers and mouse livers exposed to carbon tetrachloride. In human livers, TGFβ1 levels were highly correlated with PDE4 expression. TGFβ1 treatment of LX2 HSCs decreased levels of cAMP and EPAC1 and increased PDE4D expression. PDE4 specific inhibitor, rolipram, and an EPAC‐specific agonist decreased TGFβ1‐mediated cell migration in vitro. In vivo, targeted delivery of rolipram to the liver prevented fibrogenesis and collagen deposition and decreased the expression of several fibrosis‐related genes, and HSC activation. Proteomic analysis of mouse liver tissues identified the regulation of actin cytoskeleton by the kinase effectors of Rho GTPases as a major pathway impacted by rolipram. Western blot analyses confirmed that PDE4 inhibition decreased active MLC and endothelin 1 levels, key proteins involved in cytoskeleton remodeling and contractility. The current study, for the first time, demonstrates that PDE4 enzymes are expressed in hepatic myofibroblasts and promote cytoskeleton remodeling and HSC migration. © 2023 The Pathological Society of Great Britain and Ireland. [ABSTRACT FROM AUTHOR]

Rolipram is a selective phosphodiesterase‐4 (PDE4) inhibitor. The effect of rolipram on the metastasis of choriocarcinoma is barely known. Here, we evaluated the role of rolipram in the migration and invasion of human choriocarcinoma cells in vitro. Human choriocarcinoma cells lines JEG3 and JAR were used in this study. The expression profile of PDE4 subfamily members in choriocarcinoma cells was evaluated using real‐time PCR. The migration and invasion properties of choriocarcinoma cells before and after inhibition of PDE4 by rolipram or RNAi‐directed knockdown were evaluated in vitro. Expression levels of MMP9, TIMP1, E‐cadherin, vimentin, TGFβ1, SMAD1, and SMAD4 of choriocarcinoma cells were compared before and after rolipram treatment, RNAi‐directed knockdown of PDE4D, and overexpression of PDE4D. We found PDE4D was the most commonly expressed isoform of PDE4 both in JEG3 and JAR cells. Rolipram and knockdown of PDE4D were efficient to inhibit the migration and invasion of choriocarcinoma cells in vitro, accompanied by decreased expression of MMP9 and TIMP1. Furthermore, rolipram and knockdown of PDE4D promoted the expression of E‐cadherin but reduced the expression of vimentin in choriocarcinoma cells, and overexpression of PDE4D decreased the expression of E‐cadherin but promoted the expression of vimentin. Rolipram suppressed migration and invasion of human choriocarcinoma cells in vitro, possibly by inhibiting epithelial‐mesenchymal transition through PDE4 inhibition. [ABSTRACT FROM AUTHOR]

Palmoplantar pustulosis (PPP) is a chronic inflammatory skin disease characterised by neutrophilic granulocyte (neutrophil)-filled pustules on the palms and soles. The pathogenesis of PPP is poorly understood. This study conducted an identification of the immune mediators associated with PPP and an exploration of apremilast treatment effects on them. We screened for immune mediators elevated in blood taken from 68 patients with PPP versus control participants and included the most promising parameters in the protocol of phase the 2, multicentre study of apremilast (PDE4 inhibitor) in 21 patients with moderate-to-severe PPP (APLANTUS; EudraCT 2016-005122-11) for respective analysis of blood and skin samples of study patients. We investigated stimulated neutrophils and three-dimensional reconstituted epidermis cultures. Interleukin (IL)-19 was found to be the most upregulated immune mediator in the blood of PPP patients. IL-19 serum levels were independent of patients' age, gender, and BMI but were associated with strongly upregulated cutaneous IL-19 expression and correlated with the number of palmoplantar pustules. In patients participating in the APLANTUS study, apremilast reduced pustules more effectively than erythema and scaling. Moreover, this treatment significantly reduced IL-19 blood and skin levels. The reduction in IL-19 blood levels at week 4 correlated with the reduction in pustule counts at week 20 (end of treatment). IL-19 was expressed by neutrophils activated in vitro and induced CXCL6, a neutrophil-attracting chemokine, in epidermis models. This work demonstrates elevated IL-19 levels in the blood and skin of PPP patients and suggests a relevant role of this cytokine in the appearance of pustules in this disorder. It also suggests the suitability of IL-19 blood levels as a predictive biomarker for the treatment response of PPP patients, which should be validated in further studies. [ABSTRACT FROM AUTHOR]

IntroductionThe impact of crisaborole ointment, a nonsteroidal phosphodiesterase 4 inhibitor for the treatment of mild to moderate atopic dermatitis (AD), on quality of life (QoL) was assessed in two identically designed phase 3 studies (AD-301: NCT02118766; AD-302: NCT02118792, both at http://www.clinicaltrials.gov ).MethodsIn both studies, patients aged ≥ 2 years with mild to moderate AD per the Investigator's Static Global Assessment were randomly assigned 2:1 to receive crisaborole or vehicle twice daily for 28 days. QoL was assessed using the Children's Dermatology Life Quality Index (CDLQI) (2-15 years), the Dermatology Life Quality Index (DLQI) (≥ 16 years), and the Dermatitis Family Impact Questionnaire (DFI) (parents/caregivers/family of patients aged 2-17 years). Established QoL score severity bands provided clinical context.ResultsGreater mean improvement in QoL was observed in crisaborole-treated patients than in vehicle-treated patients at day 29 [mean change from baseline (∆BL), CDLQI: - 4.6 vs. - 3.0; P < 0.001; DLQI: - 5.2 vs. - 3.5; P = 0.015]. At baseline, more than half the patients had a "moderate effect" or higher of AD on QoL. At day 29, there was a trend toward more crisaborole- than vehicle-treated patients having "small effect" to "no effect", The QoL of parents/caregivers/family improved more for crisaborole-treated than for vehicle-treated patients (∆BL, DFI: - 3.7 vs. - 2.7; P = 0.003).ConclusionCrisaborole treatment results in clinically meaningful improvement in QoL for patients and their parents/caregivers/families.Trial registrationAD-301: http://www.clinicaltrials.gov , NCT02118766; AD-302: http://www.clinicaltrials.gov , NCT02118792.FundingAnacor Pharmaceuticals, Inc., a wholly owned subsidiary of Pfizer Inc., New York, NY.

Macrophage migration is an essential step in host defense against infection and wound healing. Elevation of cAMP by inhibiting phosphodiesterase 4 (PDE4), enzymes that specifically degrade cAMP, is known to suppress various inflammatory responses in activated macrophages, but the role of PDE4 in macrophage migration is poorly understood. Here we show that the migration of Raw 264.7 macrophages stimulated with LPS was markedly and dose-dependently induced by the PDE4 inhibitor rolipram as assessed by scratch wound healing assay. Additionally, this response required the involvement of serum in the culture medium as serum starvation abrogated the effect. Further analysis revealed that rolipram and serum exhibited synergistic effect on the migration, and the influence of serum was independent of PDE4 mRNA expression in LPS-stimulated macrophages. Moreover, the enhanced migration by rolipram was mediated by activating cAMP/exchange proteins directly activated by cAMP (Epac) signaling, presumably via interaction with LPS/TLR4 signaling with the participation of unknown serum components. These results suggest that PDE4 inhibitors, together with serum components, may serve as positive regulators of macrophage recruitment for more efficient pathogen clearance and wound repair.

Excessive alcohol use often results in alcoholic liver disease (ALD). An early change in the liver due to excessive drinking is hepatic steatosis, which may ultimately progress to hepatitis, liver fibrosis, cirrhosis, and liver cancer. Among these debilitating processes, hepatic steatosis is reversible with the appropriate treatment. Therefore, it is important to find treatments and foods that reverse hepatic steatosis. Black carrot has antioxidant and anti-inflammatory effects. In this study, we examined the effectiveness of black carrot extract (BCE) on hepatic steatosis in in vivo and in vitro ethanol-induced liver injury models. For the in vivo experiments, serum aminotransferase activities enhanced by ethanol- and carbon tetrachloride were significantly suppressed by the BCE diet. Furthermore, morphological changes in the liver hepatic steatosis and fibrosis were observed in the in vivo ethanol-induced liver injury model, however, BCE feeding resulted in the recovery to an almost normal liver morphology. In the in vitro experiments, ethanol treatment induced reactive oxygen species (ROS) levels in hepatocytes at 9 h. Conversely, ROS production was suppressed to control levels and hepatic steatosis was suppressed when hepatocyte culture with ethanol were treated with BCE. Furthermore, we investigated enzyme activities, enzyme protein levels, and messenger RNA levels of alcohol dehydrogenase (ADH), cytochrome p450 2E1 (CYP2E1), and aldehyde dehydrogenase (ALDH) using enzyme assays, western blot, and quantitative reverse transcription–polymerase chain reaction analyses. We found that the activities of ADH, CYP2E1, and ALDH were regulated through the cAMP-PKA pathway at different levels, namely, translational, posttranslational, and transcriptional levels, respectively. The most interesting finding of this study is that BCE increases cAMP levels by suppressing the Pde4b mRNA and PDE4b protein levels in ethanol-treated hepatocytes, suggesting that BCE may prevent ALD. [ABSTRACT FROM AUTHOR]

Various studies have evidenced the neuroprotective role of PDE4 inhibitors. However, whether PDE4 inhibitor, Piclamilast pharmacological post-treatment is protective during cerebral ischemia reperfusion-induced injury remains unknown. Therefore, this study design included testing the hypothesis that Piclamilast administered at the beginning of a reperfusion phase (Piclamilast pPost-trt) shows protective effects and explores & probes underlying downstream mechanisms. Swiss albino male mice were subjected to global ischemic and reperfusion injury for 17 min. The animals examined cerebral infarct size, biochemical parameters, inflammatory mediators, and motor coordination. For memory, assessment mice were subjected to morris water maze (MWM) and elevated plus maze (EPM) test. Histological changes were assessed using HE staining. Piclamilast pPost-trt significantly reduced I/R injury-induced deleterious effects on biochemical parameters of oxidative stress, inflammatory parameters, infarct size, and histopathological changes, according to the findings. These neuroprotective effects of pPost-trt are significantly abolished by pre-treatment with selective CREB inhibitor, 666–15. Current study concluded that induced neuroprotective benefits of Piclamilast Post-trt, in all probability, maybe mediated through CREB activation. Hence, its neuroprotective effects can be further explored in clinical settings. [ABSTRACT FROM AUTHOR]

Since the early 1980s, phosphodiesterase 4 (PDE4) has been an attractive target for the treatment of inflammation-based diseases. Several scientific advancements, by both academia and pharmaceutical companies, have enabled the identification of many synthetic ligands for this target, along with the acquisition of precise information on biological requirements and linked therapeutic opportunities. The transition from pre-clinical to clinical phase was not easy for the majority of these compounds, mainly due to their significant side effects, and it took almost thirty years for a PDE4 inhibitor to become a drug i.e., Roflumilast, used in the clinics for the treatment of chronic obstructive pulmonary disease. Since then, three additional compounds have reached the market a few years later: Crisaborole for atopic dermatitis, Apremilast for psoriatic arthritis and Ibudilast for Krabbe disease. The aim of this review is to provide an overview of the compounds that have reached clinical trials in the last ten years, with a focus on those most recently developed for respiratory, skin and neurological disorders. [ABSTRACT FROM AUTHOR]

Introduction: Phosphodiesterase 4 (PDE4), which regulates inflammatory cytokine production leading to atopic dermatitis (AD), is selectively inhibited by difamilast. The objective of this phase III, long-term, open-label study was to evaluate the safety and efficacy of topical difamilast in Japanese adult and pediatric patients with AD. Methods: Adult patients (n = 166) began treatment with difamilast 1% ointment, and pediatric patients began treatment with difamilast 0.3% ointment (n = 144) or difamilast 1% ointment (n = 56). Treatment was continued twice daily for 52 weeks. All patients had an Investigator's Global Assessment (IGA) score of 2 (mild), 3 (moderate), or 4 (severe/very severe), and an AD-affected body surface area (BSA) of ≥ 5% before treatment, with no restriction on the upper limit for the AD-affected BSA. Results: During therapy, 120 adult patients (72.3%) and 178 pediatric patients (89.0%) experienced treatment-emergent adverse events (TEAEs), most of which were mild or moderate in severity. Discontinuation due to TEAEs was reported in 13 adult patients (7.8%) and in 7 pediatric patients (3.5%). Treatment-related adverse events were reported in 14 adult patients (8.4%) and 16 pediatric patients (8.0%), most frequently dermatitis atopic (1.8%) and acne (1.2%) in adult patients and dermatitis atopic and pigmentation disorder (each 2.0%) in pediatric patients. The cumulative success rates in Eczema Area and Severity Index (EASI)-75 in adult and pediatric patients were 55.4% and 73.5%, respectively, at week 52, and the cumulative success rates increased from week 4 to week 52. The cumulative success rates in IGA score showed the same trend as those in EASI -75. Conclusions: This study demonstrates that difamilast ointments are well tolerated and effective in Japanese adult and pediatric patients with AD when applied twice daily for 52 weeks, and are expected to be used for a long-term treatment for AD. Clinical Trial Registration: Clinical Trials.gov identifier: NCT03961529. [ABSTRACT FROM AUTHOR]

AimsCardiac β-adrenergic receptor (βAR) signalling is susceptible to heterologous desensitization by different neurohormonal stimuli in clinical conditions associated with heart failure. We aim to examine the underlying mechanism of cross talk between βARs and a set of G-protein coupled receptors (GPCRs) activated by hormones/agonists.Methods and resultsRat ventricular cardiomyocytes were used to determine heterologous phosphorylation of βARs under a series of GPCR agonists. Activation of Gs-coupled dopamine receptor, adenosine receptor, relaxin receptor and prostaglandin E2 receptor, and Gq-coupled α1 adrenergic receptor and angiotensin II type 1 receptor promotes phosphorylation of β1AR and β2AR at putative protein kinase A (PKA) phosphorylation sites; but activation of Gi-coupled α2 adrenergic receptor and activation of protease-activated receptor does not. The GPCR agonists that promote β2AR phosphorylation effectively inhibit βAR agonist isoproterenol-induced PKA phosphorylation of phospholamban and contractile function in ventricular cardiomyocytes. Heterologous GPCR stimuli have minimal to small effect on isoproterenol-induced β2AR activation and G-protein coupling for cyclic adenosine monophosphate (cAMP) production. However, these GPCR stimuli significantly promote phosphorylation of phosphodiesterase 4D (PDE4D), and recruit PDE4D to the phosphorylated β2AR in a β-arrestin 2 dependent manner without promoting β2AR endocytosis. The increased binding between β2AR and PDE4D effectively hydrolyzes cAMP signal generated by subsequent stimulation with isoproterenol. Mutation of PKA phosphorylation sites in β2AR, inhibition of PDE4, or genetic ablation of PDE4D or β-arrestin 2 abolishes this heterologous inhibitory effect. Ablation of β-arrestin 2 or PDE4D gene also rescues β-adrenergic stimuli-induced myocyte contractile function.ConclusionsThese data reveal essential roles of β-arrestin 2 and PDE4D in a common mechanism for heterologous desensitization of cardiac βARs under hormonal stimulation, which is associated with impaired cardiac function during the development of pathophysiological conditions.

[Display omitted] • Structural optimizations of Moracin M resulted in several potent PDE4 inhibitors. • Lead L13 has an IC 50 of 36 ± 7 nM with remarkable selectivity. • L13 exhibits considerable drug-like profile. • L13 ·citrate displayed more significant anti-IPF effect than the marketed drug pirfenidone in vivo. • Docking studies on PDE4- L13 interactions mainly agree with the experimental results. Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and high mortality lung disease. Although the antifibrotic drugs pirfenidone and nintedanib could slow the rate of lung function decline, the usual course of the condition is inexorably to respiratory failure and death. Therefore, new approaches and novel therapeutic drugs for the treatment of IPF are urgently needed. And the selective PDE4 inhibitor has in vivo and in vitro anti-fibrotic effects in IPF models. But the clinical application of most PDE4 inhibitors are limited by their unexpected and severe side effects such as nausea, vomiting, and diarrhea. Herein, structure-based optimizations of the natural product Moracin M resulted in a novel a novel series of 2-arylbenzofurans as potent PDE4 inhibitors. The most potent inhibitor L13 has an IC 50 of 36 ± 7 nM with remarkable selectivity across the PDE families and administration of L13 ·citrate (10.0 mg/kg) exhibited comparable anti-pulmonary fibrosis effects to pirfenidone (300 mg/kg) in a bleomycin-induced IPF mice model, indicate that L13 is a potential lead for the treatment of IPF. [ABSTRACT FROM AUTHOR]

Objectives Psoriatic arthritis (PsA) is associated with bone erosion and inflammation-induced bone loss, which are mediated by osteoclasts (OC) and modulated by inflammatory cytokines. Apremilast (APR) (a selective phosphodiesterase 4 inhibitor) is efficacious in PsA and acts by inhibiting cytokine production. However, there are no direct data informing whether and how APR affects osteoclast formation in humans. Methods Osteoclastogenic cytokine production by activated human peripheral blood mononuclear cells (PBMCs) was measured in the presence and absence of APR. Effects of APR on osteoclast differentiation were tested (i) in co-cultures of activated PBMCs and human CD14+ blood monocytes as well as (ii) in CD14+ blood monocytes stimulated with activated-PBMCs supernatant, TNF or IL-17A. Bone resorption was measured on OsteoAssay plates. Effects of APR on ex vivo osteoclast differentiation were compared in PsA, pre-PsA and psoriasis patients, as well as in healthy controls. Results APR significantly impaired the expression of key osteoclastogenic cytokines in activated PBMCs. Furthermore, APR dose-dependently and significantly inhibited activated PBMC-driven osteoclast differentiation and ex vivo osteoclast differentiation of PBMCs derived from PsA and pre-PsA patients, but not from psoriasis patients or healthy controls. TNF and IL-17A-enhanced osteoclastogenesis and osteolytic activity of CD14+ blood monocytes from PsA patients was also significantly inhibited by APR. Finally, APR inhibited expression of the key osteoclast fusion protein dendritic cell-specific transmembrane protein. Conclusion Phosphodiesterase 4 targeting by APR not only inhibits osteoclastogenic cytokine production, but also directly suppresses inflammation-driven osteoclastogenesis. These data provide initial evidence that APR has the potential to provide a direct bone protective effect in PsA. [ABSTRACT FROM AUTHOR]

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., (© 2024 Wiley Periodicals LLC.)

Since the early 1980s, phosphodiesterase 4 (PDE4) has been an attractive target for the treatment of inflammation-based diseases. Several scientific advancements, by both academia and pharmaceutical companies, have enabled the identification of many synthetic ligands for this target, along with the acquisition of precise information on biological requirements and linked therapeutic opportunities. The transition from pre-clinical to clinical phase was not easy for the majority of these compounds, mainly due to their significant side effects, and it took almost thirty years for a PDE4 inhibitor to become a drug i.e., Roflumilast, used in the clinics for the treatment of chronic obstructive pulmonary disease. Since then, three additional compounds have reached the market a few years later: Crisaborole for atopic dermatitis, Apremilast for psoriatic arthritis and Ibudilast for Krabbe disease. The aim of this review is to provide an overview of the compounds that have reached clinical trials in the last ten years, with a focus on those most recently developed for respiratory, skin and neurological disorders.

Inhibition of phosphodiesterase 4 (PDE4) protects against neuronal apoptosis induced by cerebral ischemia. However, the exact mechanisms responsible for the protection of PDE4 inhibition have not been completely clarified. Roflumilast (Roflu) is an FDA-approved PDE4 inhibitor for the treatment of chronic obstructive pulmonary disease. The potential protective role of Roflu against ischemic stroke-associated neuronal injury remains unexplored. In this study, we investigated the effect and mechanism of Roflu against ischemic stroke using in vitro oxygen-glucose deprivation reperfusion (OGD/R) and in vivo rat middle cerebral artery occlusion (MCAO) models. We demonstrated that Roflu significantly reduced the apoptosis of HT-22 cells exposed to OGD/R, enhanced the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf-2), and reduced oxidative stress. Treatment with Roflu increased the phosphorylation of protein kinase B (Akt) and glycogen synthase kinase 3β (GSK3β) but decreased the level of phosphorylated inositol requiring enzyme 1α (IRE1α). Interestingly, constitutively active GSK3β (S9A) mutation abolished the effects of Roflu on oxidative stress and IRE1α phosphorylation. Moreover, Roflu decreased the binding of IRE1α to tumor necrosis factor receptor-associated factor 2 (TRAF2) and attenuated the phosphorylation of c-Jun N-terminal kinase (JNK). We also found that PDE4B knockdown reduced the phosphorylation of both IRE1α and JNK, while overexpression of PDE4B antagonized the role of PDE4B knockdown on the activation of IRE1α and JNK. Besides, the inhibition of PDE4 by Roflu produced similar effects in primary cultured neurons. Finally, Roflu ameliorated MCAO-induced cerebral injury by decreasing infarct volume, restoring neurological score, and reducing the phosphorylation of IRE1α and JNK. Collectively, these data suggest that Roflu protects neurons from cerebral ischemia reperfusion-mediated injury via the activation of GSK3β/Nrf-2 signaling and suppression of the IRE1α/TRAF2/JNK pathway. Roflu has the potential as a protective drug for the treatment of cerebral ischemia. Image 1 • The PDE4 inhibitor Roflumilast reduces neuronal damage caused by OGD/R and cerebral ischemia. • GSK3β (S9A) mutation blocks the anti-oxidant and protective effects of Roflumilast. • Roflumilast inhibits IRE1α/TRAF2/JNK signaling pathway. • PDE4 knockdown shows a similar effect as Roflumilast. • Roflumilast ameliorates brain injury in rats subjected to MCAO/R injury. [ABSTRACT FROM AUTHOR]

Phosphodiesterase 4 (PDE4) inhibitors are effective therapeutic agents for various inflammatory diseases. Roflumilast, apremilast, and crisaborole have been developed and approved for the treatment of chronic obstructive pulmonary disease psoriatic arthritis, and atopic dermatitis. Inflammation underlies many vascular diseases, yet the role of PDE4 inhibitors in these diseases remains inadequately explored. This review elucidates the clinical applications and anti-inflammatory mechanisms of PDE4 inhibitors, as well as their potential protective effects on vascular diseases. Additionally, strategies to mitigate the adverse reactions of PDE4 inhibitors are discussed. This article emphasizes the need for further exploration of the therapeutic potential and clinical applications of PDE4 inhibitors in vascular diseases., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Fan, Wang, Wang, Zeng, Liu, Zhu and Yang.)

Objective: Salt-induced kinase 1 (SIK1) acts as a key modulator in many physiological processes. However, the effects of SIK1 on gluconeogenesis and the underlying mechanisms have not been fully elucidated. In this study, we found that a natural compound phanginin A could activate SIK1 and further inhibit gluconeogenesis. The mechanisms by which phanginin A activates SIK1 and inhibits gluconeogenesis were explored in primary mouse hepatocytes, and the effects of phanginin A on glucose homeostasis were investigated in ob/ob mice. Methods: The effects of phanginin A on gluconeogenesis and SIK1 phosphorylation were examined in primary mouse hepatocytes. Pan-SIK inhibitor and siRNA-mediated knockdown were used to elucidate the involvement of SIK1 activation in phanginin A-reduced gluconeogenesis. LKB1 knockdown was used to explore how phanginin A activated SIK1. SIK1 overexpression was used to evaluate its effect on gluconeogenesis, PDE4 activity, and the cAMP pathway. The acute and chronic effects of phanginin A on metabolic abnormalities were observed in ob/ob mice. Results: Phanginin A significantly increased SIK1 phosphorylation through LKB1 and further suppressed gluconeogenesis by increasing PDE4 activity and inhibiting the cAMP/PKA/CREB pathway in primary mouse hepatocytes, and this effect was blocked by pan-SIK inhibitor HG-9-91-01 or siRNA-mediated knockdown of SIK1. Overexpression of SIK1 in hepatocytes increased PDE4 activity, reduced cAMP accumulation, and thereby inhibited gluconeogenesis. Acute treatment with phanginin A reduced gluconeogenesis in vivo, accompanied by increased SIK1 phosphorylation and PDE4 activity in the liver. Long-term treatment of phanginin A profoundly reduced blood glucose levels and improved glucose tolerance and dyslipidemia in ob/ob mice. Conclusion: We discovered an unrecognized effect of phanginin A in suppressing hepatic gluconeogenesis and revealed a novel mechanism that activation of SIK1 by phanginin A could inhibit gluconeogenesis by increasing PDE4 activity and suppressing the cAMP/PKA/CREB pathway in the liver. We also highlighted the potential value of phanginin A as a lead compound for treating type 2 diabetes.

Inhibition of phosphodiesterase 4 (PDE4) is a promising therapeutic approach for the treatment of inflammatory pulmonary disorders, i.e. asthma and chronic obstructive pulmonary disease. However, the treatment with non-selective PDE4 inhibitors is associated with side effects such as nausea and vomiting. Among the subtypes of PDE4 inhibited by these inhibitors, PDE4B is expressed in immune, inflammatory and airway smooth muscle cells, whereas, PDE4D is expressed in the area postrema and nucleus of the solitary tract. Thus, PDE4D inhibition is responsible for the emetic response. In this regard, a selective PDE4B inhibitor is expected to be a potential drug candidate for the treatment of inflammatory pulmonary disorders. Therefore, a shared feature pharmacophore model was developed and used as a query for the virtual screening of Maybridge and SPECS databases. A number of filters were applied to ensure only compounds with drug-like properties were selected. Accordingly, nine compounds have been identified as final hits, where HTS04529 showed the highest affinity and selectivity for PDE4B over PDE4D in molecular docking. The docked complexes of HTS04529 with PDE4B and PDE4D were subjected to molecular dynamics simulations for 100ns to assess their binding stability. The results showed that HTS04529 was bound tightly to PDE4B and formed a more stable complex with it than with PDE4D.

The phosphodiesterase 4 inhibitor apremilast is used for the treatment of psoriasis. We investigated the effects of apremilast on endothelial glycocalyx, vascular and left ventricular (LV) myocardial function in psoriasis. One hundred and fifty psoriatic patients were randomized to apremilast (n = 50), anti-tumor necrosis factor-α (etanercept; n = 50), or cyclosporine (n = 50). At baseline and 4 months post-treatment, we measured: (1) Perfused boundary region (PBR), a marker of glycocalyx integrity, in sublingual microvessels with diameter 5–25 μm using a Sidestream Dark Field camera (GlycoCheck). Increased PBR indicates damaged glycocalyx. Functional microvascular density, an index of microvascular perfusion, was also measured. (2) Pulse wave velocity (PWV-Complior) and (3) LV global longitudinal strain (GLS) using speckle-tracking echocardiography. Compared with baseline, PBR5–25 μm decreased only after apremilast (−12% at 4 months, p < 0.05) whereas no significant changes in PBR5–25 μm were observed after etanercept or cyclosporine treatment. Compared with etanercept and cyclosporine, apremilast resulted in a greater increase of functional microvascular density (+14% versus +1% versus −1%) and in a higher reduction of PWV. Apremilast showed a greater increase of GLS (+13.5% versus +7% versus +2%) than etanercept and cyclosporine (p < 0.05). In conclusion, apremilast restores glycocalyx integrity and confers a greater improvement of vascular and myocardial function compared with etanercept or cyclosporine after 4 months.

Abstract Introduction The impact of crisaborole ointment, a nonsteroidal phosphodiesterase 4 inhibitor for the treatment of mild to moderate atopic dermatitis (AD), on quality of life (QoL) was assessed in two identically designed phase 3 studies (AD-301: NCT02118766; AD-302: NCT02118792, both at http://www.clinicaltrials.gov). Methods In both studies, patients aged ≥ 2 years with mild to moderate AD per the Investigator’s Static Global Assessment were randomly assigned 2:1 to receive crisaborole or vehicle twice daily for 28 days. QoL was assessed using the Children’s Dermatology Life Quality Index (CDLQI) (2–15 years), the Dermatology Life Quality Index (DLQI) (≥ 16 years), and the Dermatitis Family Impact Questionnaire (DFI) (parents/caregivers/family of patients aged 2–17 years). Established QoL score severity bands provided clinical context. Results Greater mean improvement in QoL was observed in crisaborole-treated patients than in vehicle-treated patients at day 29 [mean change from baseline (∆BL), CDLQI: − 4.6 vs. − 3.0; P < 0.001; DLQI: − 5.2 vs. − 3.5; P = 0.015]. At baseline, more than half the patients had a “moderate effect” or higher of AD on QoL. At day 29, there was a trend toward more crisaborole- than vehicle-treated patients having “small effect” to “no effect”, The QoL of parents/caregivers/family improved more for crisaborole-treated than for vehicle-treated patients (∆BL, DFI: − 3.7 vs. − 2.7; P = 0.003). Conclusion Crisaborole treatment results in clinically meaningful improvement in QoL for patients and their parents/caregivers/families. Trial Registration AD-301: http://www.clinicaltrials.gov, NCT02118766; AD-302: http://www.clinicaltrials.gov, NCT02118792. Funding Anacor Pharmaceuticals, Inc., a wholly owned subsidiary of Pfizer Inc., New York, NY.

Diabetic nephropathy (DN) is a leading cause of end‐stage renal disease (ESRD). Hypertension increases kidney stress, which deteriorates function, and leads to peripheral renal vascular resistance. Long‐term hypoperfusion promotes interstitial fibrosis and glomerular sclerosis, resulting in nephrosclerosis. Although hypertension and DN are frequent ESRD complications, relevant animal models remain unavailable. We generated a deoxycorticosterone acetate (DOCA)‐salt hypertensive uni‐nephrectomized (UNx) KKAy mouse model demonstrating hypertension, hyperglycemia, cardiac hypertrophy, kidney failure, increased urinary albumin creatinine ratio (UACR), and increased renal PDE4D and cardiac PDE5A mRNA levels. We hypothesized that the novel PDE4 selective inhibitor, compound A, and PDE5 inhibitor, sildenafil, exhibit nephroprotective, and cardioprotective effects in this new model. Compound A, sildenafil, and the angiotensin II receptor blocker, irbesartan, significantly reduced ventricular hypertrophy and pleural effusion volume. Meanwhile, compound A and sildenafil significantly suppressed the UACR, urinary kidney injury molecule‐1, and monocyte chemoattractant protein‐1 levels, as well as that of renal pro‐fibrotic marker mRNAs, including collagen 1A1, fibronectin, and transforming growth factor‐beta (TGF‐β). Moreover, compound A significantly suppressed TGF‐β‐induced pro‐fibrotic mRNA expression in vitro in all major kidney lesions, including within the glomerular mesangial region, podocytes, and epithelial region. Hence, PDE4 and PDE5 inhibitors may be promising treatments, in combination with irbesartan, for DN with hypertension as they demonstrate complementary mechanisms. [ABSTRACT FROM AUTHOR]

Introduction: Preclinical studies suggest a link between cAMP/PKA signalling, phosphodiesterase 4 (PDE4) expression and excessive daytime sleepiness (EDS). Here, we investigated in vivo the association between PDE4 expression and EDS in Parkinson's disease (PD) patients using [11C]rolipram PET and MR imaging.Methods: Eighteen participants, 12 PD and 6 healthy controls, underwent one [11C]rolipram PET and a multi-modal MRI scan. Probabilistic tractography was performed on subjects' diffusion data to functionally parcellate the striatum according with projections to limbic cortical areas. The severity of EDS was assessed using the Epworth Sleepiness Scale (ESS). To assess PDE4 expression in PD patients with EDS, the PD cohort was divided according to the presence (n = 5) or absence (n = 7) of EDS, defined using validated cut-off of score ≥10 on the ESS as score ≥10 on the ESS.Results: PD patients with EDS showed significantly increased [11C]rolipram volume of distribution (VT) in the caudate (P = 0.029), hypothalamus (P = 0.013), hippocampus (P = 0.036) and limbic striatum (P = 0.030) compared to patients without EDS. Furthermore, higher ESS scores correlated with increased [11C]rolipram VT in the caudate (r = 0.77; P = 0.003), hypothalamus (r = 0.84; P = 0.001), hippocampus (r = 0.81; P = 0.001) and limbic subdivisions of the striatum (r = 0.80; P = 0.003).Conclusion: Our findings translate into humans preclinical data indicating that EDS is associated with elevated PDE4 in regions regulating sleep. The severity of EDS in PD was associated with elevated PDE4 expression; thus, suggesting a role of PDE4 in the pathophysiology of EDS in PD. [ABSTRACT FROM AUTHOR]

Background: The cyclic AMP (adenosine monophosphate; cAMP)-hydrolyzing protein PDE4B (phosphodiesterase 4B) is a key negative regulator of cardiac β-adrenergic receptor stimulation. PDE4B deficiency leads to abnormal Ca2+ handling and PDE4B is decreased in pressure overload hypertrophy, suggesting that increasing PDE4B in the heart is beneficial in heart failure.Methods: We measured PDE4B expression in human cardiac tissues and developed 2 transgenic mouse lines with cardiomyocyte-specific overexpression of PDE4B and an adeno-associated virus serotype 9 encoding PDE4B. Myocardial structure and function were evaluated by echocardiography, ECG, and in Langendorff-perfused hearts. Also, cAMP and PKA (cAMP dependent protein kinase) activity were monitored by Förster resonance energy transfer, L-type Ca2+ current by whole-cell patch-clamp, and cardiomyocyte shortening and Ca2+ transients with an Ionoptix system. Heart failure was induced by 2 weeks infusion of isoproterenol or transverse aortic constriction. Cardiac remodeling was evaluated by serial echocardiography, morphometric analysis, and histology.Results: PDE4B protein was decreased in human failing hearts. The first PDE4B-transgenic mouse line (TG15) had a ≈15-fold increase in cardiac cAMP-PDE activity and a ≈30% decrease in cAMP content and fractional shortening associated with a mild cardiac hypertrophy that resorbed with age. Basal ex vivo myocardial function was unchanged, but β-adrenergic receptor stimulation of cardiac inotropy, cAMP, PKA, L-type Ca2+ current, Ca2+ transients, and cell contraction were blunted. Endurance capacity and life expectancy were normal. Moreover, these mice were protected from systolic dysfunction, hypertrophy, lung congestion, and fibrosis induced by chronic isoproterenol treatment. In the second PDE4B-transgenic mouse line (TG50), markedly higher PDE4B overexpression, resulting in a ≈50-fold increase in cardiac cAMP-PDE activity caused a ≈50% decrease in fractional shortening, hypertrophy, dilatation, and premature death. In contrast, mice injected with adeno-associated virus serotype 9 encoding PDE4B (1012 viral particles/mouse) had a ≈50% increase in cardiac cAMP-PDE activity, which did not modify basal cardiac function but efficiently prevented systolic dysfunction, apoptosis, and fibrosis, while attenuating hypertrophy induced by chronic isoproterenol infusion. Similarly, adeno-associated virus serotype 9 encoding PDE4B slowed contractile deterioration, attenuated hypertrophy and lung congestion, and prevented apoptosis and fibrotic remodeling in transverse aortic constriction.Conclusions: Our results indicate that a moderate increase in PDE4B is cardioprotective and suggest that cardiac gene therapy with PDE4B might constitute a new promising approach to treat heart failure. [ABSTRACT FROM AUTHOR]

Tumor necrosis factor-α (TNF-α) is a critical pro-inflammatory cytokine regulating neuroinflammation. At high concentrations, it is toxic to neurons, and such damage is positively correlated with acute and chronic neurological diseases. Our previous studies showed that inhibition of phosphodiesterase 4 (PDE4) attenuated the production of TNF-α induced by lipopolysaccharides in microglial cells. However, whether PDE4 inhibition can block the neurotoxic effects of TNF-α in neuronal cells is unknown. In this study, we investigated the protective effects of FCPR16, a novel PDE4 inhibitor, against TNF-α-induced cellular apoptosis in HT-22 hippocampal neuronal cells. We demonstrated that FCPR16 dose-dependently increased the viability of HT-22 cells exposed to TNF-α insult. Propidium iodide/calcein staining and flow cytometry analysis showed that FCPR16 decreased cell apoptosis triggered by TNF-α. Western blot analysis showed that FCPR16 decreased the level of cleaved caspase 3 and caspase 8, but had no effect on caspase 9. Mechanistically, FCPR16 blocked the TNF-α-induced phosphorylation of c-Jun N-terminal kinase (JNK) in HT-22 cells, and inhibition of JNK showed a similar protective effect as FCPR16. Furthermore, FCPR16 decreased the translocation of nuclear factor-κB (NF-κB) p65 from the cytosol into the nucleus. In addition, FCPR16 decreased the expression of inducible nitric oxide synthase and the production of reactive oxygen species in HT-22 cells exposed to TNF-α. Moreover, knockdown of PDE4B by specific small interfering RNA reduced the apoptosis of HT-22 cells treated with TNF-α. Taken together, our findings suggest that FCPR16 promotes the survival of neuronal cells exposed to TNF-α by suppressing the activation of JNK and NF-κB. [ABSTRACT FROM AUTHOR]

β‐Adrenergic receptor (β‐AR) agonists are the most common clinical bronchodilators for asthma. Obesity influences asthma severity and may impair response to β‐AR agonists. Previous studies show that in obese mice, hyperinsulinemia plays a crucial role in β‐AR desensitization in the heart. We therefore investigated whether insulin promotes β‐AR desensitization in airway smooth muscle (ASM) and compromises airway relaxation responsiveness to β‐AR agonists. We found that human ASM cells and mouse airway tissues exposed to insulin exhibit impaired β2AR‐induced cAMP accumulation and airway relaxation. This impaired relaxation is associated with insulin‐induced phosphorylation and expression of phosphodiesterase 4D (PDE4D) through transactivation of a G protein‐coupled receptor kinase 2 (GRK2)‐dependent β2AR‐Gi‐ERK1/2 cascade. Both acute and chronic pharmacological inhibition of PDE4 effectively reversed impaired β2AR‐mediated ASM relaxation in an obesity mouse model induced by a high fat diet. Collectively, these findings reveal that cross talk between insulin and β2AR signaling promotes ASM β2AR desensitization in obesity through upregulation of PDE4D phosphorylation and expression. Our results identify a novel pathway of asthma pathogenesis in patients with obesity/metabolic syndrome, in which the GRK2‐mediated signaling can be a potential therapeutic modality to prevent or treat β2AR desensitization in ASM. Moreover, PDE4 inhibitors may be used as efficacious therapeutic agents for asthma in obese and diabetic subjects. [ABSTRACT FROM AUTHOR]

Nephrotoxicity is a known clinical complication of cisplatin that limits the use of this potent antitumor drug. Cyclic nucleotide phosphodiesterases (PDEs) play complex roles in physiology and pathology. PDE4, which is a member of the PDE family, has four subtypes (PDE4A-PDE4D), and PDE4B plays an important role in inflammation. Thus, in the present study, we investigated the effect of PDE4/PDE4B inhibition on renal function and inflammation in a cisplatin nephrotoxicity model. In mice, cisplatin enhanced mRNA and protein expression of PDE4B in renal tubules. After treatment with the PDE4 inhibitor cilomilast, cisplatininduced renal dysfunction, renal tubular injury, tubular cell apoptosis, and inflammation were all improved. Next, after silencing PDE4B in vivo, we observed a protective effect against cisplatin nephrotoxicity similar to that of the PDE4 inhibitor. In vitro, cisplatin-induced renal tubular cell death was strikingly ameliorated by the PDE4 inhibitor and PDE4B knockdown along with the blockade of the inflammatory response. Considering the known roles of some cell survival pathways in antagonizing insults, we examined levels of PDE4-associated proteins sirtuin 1, phosphatidylinositol 3-kinase, and phosphorylated AKT in cisplatin-treated renal tubular cells with or without cilomilast treatment. Strikingly, cisplatin treatment downregulated the expression of the above proteins, and this effect was largely abolished by the PDE4 inhibitor. Together, these findings indicate the beneficial role of PDE4/PDE4B inhibition in treating cisplatin nephrotoxicity, possibly through antagonizing inflammation and restoring cell survival signaling pathways. [ABSTRACT FROM AUTHOR]

• The adenosine analog NECA and prostaglandin E 2 (PGE 2) enhanced the IL-4/IL-13-induced production of M2a chemokines by human lung macrophages. • The inhibition of phosphodiesterases 4 (PDE4) by roflumilast did not alter the production of M2a chemokines. • The present results contrast totally with the previously reported inhibitory effects of NECA, PGE 2 , and PDE4 inhibitors on the lipopolysaccharide-induced release of tumor necrosis factor alpha and M1 chemokines by human lung macrophages. Lung macrophages (LMs) are critically involved in respiratory diseases. The primary objective of the present study was to determine whether or not an adenosine analog (NECA) and prostaglandin E 2 (PGE 2) affected the interleukin (IL)-4- and IL-13-induced release of M2a chemokines (CCL13, CCL17, CCL18, and CCL22) by human LMs. Primary macrophages isolated from resected human lungs were incubated with NECA, PGE 2 , roflumilast, or vehicle and stimulated with IL-4 or IL-13 for 24 h. The levels of chemokines and PGE 2 in the culture supernatants were measured using ELISAs and enzyme immunoassays. Exposure to IL-4 (10 ng/mL) and IL-13 (50 ng/mL) was associated with greater M2a chemokine production but not PGE 2 production. PGE 2 (10 ng/mL) and NECA (10-6 M) induced the production of M2a chemokines to a lesser extent but significantly enhanced the IL-4/IL-13-induced production of these chemokines. At either a clinically relevant concentration (10-9 M) or at a concentration (10-7 M) that fully inhibited phosphodiesterase 4 (PDE4) activity, roflumilast did not increase the production of M2a chemokines and did not modulate their IL-13-induced production, regardless of the presence or absence of PGE 2. NECA and PGE 2 enhanced the IL-4/IL-13-induced production of M2a chemokines. The inhibition of PDE4 by roflumilast did not alter the production of these chemokines. These results contrast totally with the previously reported inhibitory effects of NECA, PGE 2 , and PDE4 inhibitors on the lipopolysaccharide-induced release of tumor necrosis factor alpha and M1 chemokines in human LMs. [ABSTRACT FROM AUTHOR]

Chronic obstructive pulmonary disease (COPD) is a significant disease threatening human health. Currently, roflumilast, a phosphodiesterase (PDE)4 inhibitor, is recommended as a therapeutic agent for COPD. In this study, we investigated the therapeutic effects of melatonin against COPD, focusing on determining whether it is a PDE4 inhibitor via in vivo and in vitro experiment using cigarette smoke (CS) and cigarette smoke condensate (CSC), respectively. In the in vivo experiments, melatonin treatment reduced inflammatory responses, including inflammatory cell counts. Melatonin treatment also suppressed the CS-exposure-induced upregulation of cytokine and matrix metalloproteinase (MMP)-9, reduced the PDE4B expression, and elevated cAMP levels. In addition, these effects were synergistic, as melatonin and roflumilast cotreatment eventually ameliorated the CS-exposure-induced worsening of lung function. In the CSC-stimulated NCI-H292 cells, melatonin inhibited elevation in the levels of inflammatory cytokines, MMP-9, and PDE4, and elevated cAMP levels. Furthermore, melatonin and roflumilast cotreatment was more effective on inflammatory responses than only melatonin or roflumilast treatment. Our results indicate that melatonin relieves inflammatory response and loss of lung function in COPD, which is associated with decreased PDE4 expression. Therefore, we suggest that melatonin is a putative candidate for the treatment of COPD.

This article presents current data from publications on new direction in systematic treatment of patients with psoriasis with help of "small molecules" that act intracellularly, selectively inhibiting signaling pathways responsible for production of key pro- and anti-inflammatory mediators that play an important role in the pathophysiology of psoriasis. We discuss key issues that refer to immunopathogenesis of psoriasis, targeted influence of "small molecules" on key components of innate and adaptive immune system of patients psoriasis. This article presents results of the studies performed according to the evidence-based medicine approaches, on the efficiency and safety of apremilast - the first and only current selective inhibitor of intracellular phosphodiesterase 4 - for treating medium-severe and severe psoriasis, including patients with problematic localizations of dermatosis (psoriasis of scalp pilar part, palms, soles, nail plates), as well as in the long run. It is shown that continuous apremilast therapy for the term of 52-156 weeks was accompanied by a significant decrease in prevalence and severity of psoriasis. Adverse events were recorded rarely, they were mild, and frequency of serious adverse reactions was comparable to placebo.

Crisaborole ointment 2% is a nonsteroidal phosphodiesterase 4 inhibitor for the treatment of mild-to-moderate atopic dermatitis (AD). The mechanism of action of crisaborole and its effects on lesional measures of disease severity are not yet well defined. This phase 2a, single-center, vehicle-controlled, intrapatient study was designed to further characterize the mechanism of action of crisaborole through evaluation of clinical efficacy and changes in skin biomarkers in adults (n = 40) with mild-to-moderate AD. Two target lesions were randomized in an intrapatient (1:1) manner to double-blind crisaborole/vehicle applied twice daily for 14 days. Patients then applied crisaborole (open-label) to all affected areas for 28 days. Punch biopsy specimens were collected for biomarker analysis at baseline, day 8 (optional), and day 15. Crisaborole treatment resulted in early improvement in lesional signs/symptoms versus vehicle, with improvement in pruritus (pruritus numeric rating scale) observed as early as 24 hours after the first application. Crisaborole-treated lesions showed significant percentage improvement from baseline in lesional transcriptomic profile compared with vehicle at day 8 (91.15% vs 36.02%, P < 10−15) that was sustained until day 15 (92.90% vs 49.59%, P < 10−15). Crisaborole significantly modulated key AD biomarkers versus vehicle, including T H 2 and T H 17/T H 22 pathways and epidermal hyperplasia/proliferation. Molecular profiles and epidermal pathology normalized toward nonlesional skin and correlated with clinical changes in lesion severity and barrier function. Crisaborole reversed biomarker profiles of skin inflammation and barrier function, with associated improvements in clinical efficacy measures, highlighting the therapeutic utility of targeting phosphodiesterase 4 in patients with AD. [ABSTRACT FROM AUTHOR]

Although still a matter of controversy, disrupted in schizophrenia protein 1 (DISC1) was suggested as a potential inhibitor of phosphodiesterase 4 (PDE4). We used Disc1 locus impairment (LI) mice to investigate the interaction between PDE4 and DISC 1 in vivo and in vitro. [11C](R)-Rolipram binding was measured by PET in LI (n = 11) and C57BL/6 wild-type (WT, n = 9) mice. [11C](R)-Rolipram total distribution volumes (V T) were calculated and corrected for plasma-free fraction (f P) measured in a separate group of LI (n = 6) and WT (n = 7) mice. PDE4 enzyme activity was measured using in vitro samples of cerebral cortices from groups of LI (n = 4), heterozygote (n = 4), and WT (n = 4) mice. Disc1 LI mice showed a 41% increase in V T (18 ± 6 vs. 13±4 mL/cm3, P = 0.04) compared to WT mice. V T/ f P showed a 73% significant increase (90 ± 31 vs. 52 ± 15 mL/cm3, P = 0.004) in Disc1 LI compared to WT mice. PDE4 enzymatic activity assay confirmed in vivo findings showing significant group differences (p < 0.0001). In conclusion, PDE4 activity was increased in the absence of critical DISC1 protein isoforms both in vivo and in vitro. Additionally, [11C](R)-Rolipram PET was sensitive enough to assess altered PDE4 activity caused by PDE4–DISC1 interaction. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Inhibition of phosphodiesterase 4 (PDE4) is a promising strategy for the treatment of ischemic stroke. However, the side effects of nausea and vomiting from the current PDE4 inhibitors have limited their clinical applications. FCPR03 is a novel PDE4 inhibitor with little emetic potential. This study aimed to investigate the effects of FCPR03 on neuronal injury after cerebral ischemia/reperfusion and the underlying signaling pathway. The effects of FCPR03 on cellular apoptosis, intracellular accumulation of reactive oxygen species (ROS), and mitochondrial membrane potential (MMP) were evaluated in HT-22 neuronal cells and cortical neurons exposed to oxygen-glucose deprivation (OGD). The impact of FCPR03 on brain injury, neurological scores and behavioral performance was investigated in rats subjected to middle cerebral artery occlusion (MCAO). The protein kinase B (AKT) inhibitor MK-2206 and β-catenin siRNA were used to investigate the underlying pathways. FCPR03 dose-dependently protected against OGD-induced cellular apoptosis in both HT-22 cells and cortical neurons. The levels of MMP and ROS were also restored by FCPR03. FCPR03 increased the levels of phosphorylated AKT, glycogen synthase kinase-3β (GSK3β), and β-catenin. Interestingly, the role of FCPR03 was reversed by MK-2206 and β-catenin siRNA. Consistently, FCPR03 reduced the infarct volume and improved neurobehavioral outcomes in rats following MCAO. Moreover, FCPR03 increased the levels of phosphorylated AKT, GSK3β and β-catenin within the ischemic penumbra of rats following cerebral ischemia-reperfusion. Taken together, FCPR03 has therapeutic potential in cerebral ischemia-reperfusion. The neuroprotective effects of FCPR03 are mediated through activation of the AKT/GSK3β/β-catenin pathway. [ABSTRACT FROM AUTHOR]

Purpose: Roflumilast (Daliresp, Daxas) is a FDA-approved phosphodiesterase 4 (PDE4) inhibitor for the treatment of moderate-to-severe chronic obstructive pulmonary disease. In mice and in limited human studies, this oral medication can cause weight loss and improve insulin sensitivity. We set out to determine the mechanism of its effect on insulin sensitivity. Patients and methods: Eight adults with overweight/obesity and prediabetes received roflumilast for 6 weeks. Before and after roflumilast, subjects underwent tests of insulin sensitivity, mixed meal test, body composition, markers of inflammation, and mitochondria function. Dietary intake and physical activity were also assessed. Our primary outcome was the change in peripheral insulin sensitivity, as assessed by the hyper-insulinemic euglycemic clamp. Results: This study was underpowered for the primary outcome. Pre- and post-roflumilast mean peripheral insulin sensitivity were 48.7 and 70.0 mg/g fat free mass/minute, respectively, (P-value=0.18), respectively. Among the mixed meal variables, roflumilast altered glucagon-like peptide 1 (GLP-1) hormone the most, although the average effect was not statistically significant (P=0.18). Roflumilast induced a trend toward significance in 1) decreased energy intake (from 11,095 KJ to 8,4555 KJ, P=0.07), 2) decreased fat mass (from 34.53 to 32.97 kg, P=0.06), 3) decreased total and LDL cholesterol (P=0.06 for both variables), and 4) increased plasma free fatty acids (from 0.40 to 0.50 mEq/L, P=0.09) The interval changes in adiposity and free fatty acid were significantly associated with the subject's age (P-value range=<0.001 to 0.02 for the correlations). Inflammatory and adhesion markers, though unchanged, significantly correlated with one another and with incretin hormones only after roflumilast. Conclusion: We demonstrate, for the first time in humans, increasing percentage of fat mass loss from roflumilast with increasing age in adults with prediabetes and overweight/obesity. We also demonstrate novel associations among roflumilast-induced changes in incretin hormones, inflammatory markers, peripheral insulin sensitivity, and adiposity. We conclude that roflumilast's early effects on insulin sensitivity is indirect and likely mediated through roflumilast's prioritization of lipid over glucose handling. Clinical trials registration: NCT01862029. [ABSTRACT FROM AUTHOR]

Background Phosphodiesterase 4 is a promising target for developing novel antidepressants. However, prototype phosphodiesterase 4 inhibitors show severe side effects, including nausea and vomiting. N-Isopropyl-3-(cyclopropylmethoxy)-4-difluoromethoxy benzamide (FCPR03) is a novel phosphodiesterase 4 inhibitor with little emetic potential. In the present study, we investigated the inhibitory effect of FCPR03 on chronic unpredictable mild stress-induced, depressive-like behaviors in mice and explored the underlying mechanisms. Methods The depression model of mice was established by chronic unpredictable mild stress. Forced swim test, tail suspension test, and sucrose preference test were used to assess depressive-like behaviors. Golgi-staining was utilized to analyze dendritic morphology and spine density. The level of cAMP was measured by enzyme-linked immnosorbent assay assay. Western blot was used to evaluate protein levels of phosphorylated cAMP-response element binding protein, protein kinase B, glycogen synthase kinase-3β, and brain derived neurotrophic factor in both hippocampus and prefrontal cortex. Postsynaptic density protein 95 and synapsin 1 were also detected by western blot in the hippocampi. Results Treatment with FCPR03 (0.5–1.0 mg/kg, i.p.) increased consumption of sucrose in the sucrose preference test in mice exposed to chronic unpredictable mild stress. FCPR03 shortened the immobility time in forced swim test and tail suspension test without affecting locomotor activity. Furthermore, chronic unpredictable mild stress decreased the dendritic spine density and dendritic length in the hippocampus. This change was accompanied by decreased expression of postsynaptic density protein 95 and synapsin 1. Interestingly, FCPR03 prevented dendritic spine loss and increased synaptic protein levels. Moreover, the levels of cAMP, phosphorylated cAMP-response element binding protein, and brain derived neurotrophic factor were elevated in chronic unpredictable mild stress-challenged mice after treatment with FCPR03. In addition, FCPR03 also enhanced the phosphorylation of both protein kinase B and glycogen synthase kinase-3β in mice exposed to chronic unpredictable mild stress. Conclusion The present study suggests that FCPR03 could prevent both depressive-like behaviors and spine loss induced by chronic unpredictable mild stress in the mice hippocampi. [ABSTRACT FROM AUTHOR]

Apremilast (APR) is a selective phosphodiesterase 4 inhibitor administered orally in the treatment of moderate-to-severe plaque psoriasis and active psoriatic arthritis. The low solubility and permeability of this drug hinder its dermal administration. The purpose of this study was to design and characterize an apremilast-loaded microemulsion (APR-ME) as topical therapy for local skin inflammation. Its composition was determined using pseudo-ternary diagrams. Physical, chemical and biopharmaceutical characterization were performed. Stability of this formulation was studied for 90 days. Tolerability of APR-ME was evaluated in healthy volunteers while its anti-inflammatory potential was studied using in vitro and in vivo models. A homogeneous formulation with Newtonian behavior and droplets of nanometric size and spherical shape was obtained. APR-ME released the incorporated drug following a first-order kinetic and facilitated drug retention into the skin, ensuring a local effect. Anti-inflammatory potential was observed for its ability to decrease the production of IL-6 and IL-8 in the in vitro model. This effect was confirmed in the in vivo model histologically by reduction in infiltration of inflammatory cells and immunologically by decrease of inflammatory cytokines IL-8, IL-17A and TNFα. Consequently, these results suggest that this formulation could be used as an attractive topical treatment for skin inflammation.