PDE4 Inhibitor Research Articles

Low PDE4A expression promoted the progression of ovarian cancer by inducing Snail nuclear translocation

Widespread metastasis is the primary reason for the high mortality associated with ovarian cancer (OC), and effective targeted therapy for tumor aggressiveness is still insufficient in clinical practice. Therefore, it is urgent to find new targets to improve prognosis of patients. PDE4A is a cyclic nucleotide phosphodiesterase that plays a crucial role in the occurrence and development in various malignancies. Our study firstly reported the function of PDE4A in OC. Expression of PDE4A was validated through bioinformatics analysis, RT-qPCR, Western blot, and immunohistochemistry. Additionally, its impact on cell growth and motility was assessed via in vitro and in vivo experiments. PDE4A was downregulated in OC tissues compared with normal tissues and low PDE4A expression was correlated with poor clinical outcomes in OC patients. The knockdown of PDE4A significantly promoted the proliferation, migration and invasion of OC cells while overexpression of PDE4A resulted in the opposite effect. Furthermore, smaller and fewer tumor metastatic foci were observed in mice bearing PDE4A-overexpressing OVCAR3 cells. Mechanistically, downregulation of PDE4A expression can induce epithelial-mesenchymal transition (EMT) and nuclear translocation of Snail, which suggests that PDE4A plays a pivotal role in suppressing OC progression. Notably, Rolipram, the PDE4 inhibitor, mirrored the effects observed with PDE4A deletion. In summary, the downregulation of PDE4A appears to facilitate OC progression by modulating the Snail/EMT pathway, underscoring the potential of PDE4A as a therapeutic target against ovarian cancer metastasis.

Advances in the Study of PDE4 Inhibitors in Dermatological Disorders

Since the 1980s, phosphodiesterase 4 (PDE-4) has been one of the most prominent targets for the treatment of inflammatory diseases. More recently, a number of synthetic ligands targeting PDE-4 have received more attention in the academic and pharmaceutical communities and are expected to have applications in these diseases. Due to various potential side effects of PDE-4 inhibitors, there are several obstacles to the clinical translation of specific PDE-4 inhibitors from the preclinical to the clinical phase. Therefore, similar to roflumilast in chronic obstructive pulmonary disease, many PDE-4 inhibitors can take up to 30 years or even longer from development to clinical application. This article is a review of the development of PDE-4 inhibitors, such as crisaborole and apremilast, for use in skin disorders.

Diaporchalasin A, a new PDE4 inhibitory cytochalasin from Conus marmoreus-derived fungus Diaporthe sp. XMA007

A novel cytochalasin named diaporchalasin A (1) bearing a cinnamenyl and an epoxy-macrocycloketone, and a new benzenepropionic acid derivative (2), and two known compounds (3 and 4) were isolated from Conus marmoreus-derived fungus Diaporthe sp. XMA007. Their structures were elucidated through detailed spectroscopic analysis, and the absolute configuration of 1 was determined by conformational analysis and TDDFT-ECD calculation. Their activity evaluation on PDE4 inhibition and breast cancer cell cytotoxicity were conducted, and compound 1 showed moderate inhibition on PDE4.

Structural optimization of Moracin M as novel selective phosphodiesterase 4 inhibitors for the treatment of idiopathic pulmonary fibrosis

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 IC50 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.

Amelioration of functional and histopathological consequences after spinal cord injury through phosphodiesterase 4D (PDE4D) inhibition

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.

Nobiletin Stimulates Adrenal Hormones and Modulates the Circadian Clock in Mice.

Polymethoxyflavonoids, such as nobiletin (abundant in Citrus depressa), have been reported to have antioxidant, anti-inflammatory, anticancer, and anti-dementia effects, and are also a circadian clock modulator through retinoic acid receptor-related orphan receptor (ROR) α/γ. However, the optimal timing of nobiletin intake has not yet been determined. Here, we explored the time-dependent treatment effects of nobiletin and a possible novel mechanistic idea for nobiletin-induced circadian clock regulation in mice. In vivo imaging showed that the PER2::LUC rhythm in the peripheral organs was altered in accordance with the timing of nobiletin administration (100 mg/kg). Administration at ZT4 (middle of the light period) caused an advance in the peripheral clock, whereas administration at ZT16 (middle of the dark period) caused an increase in amplitude. In addition, the intraperitoneal injection of nobiletin significantly and potently stimulated corticosterone and adrenaline secretion and caused an increase in Per1 expression in the peripheral tissues. Nobiletin inhibited phosphodiesterase (PDE) 4A1A, 4B1, and 10A2. Nobiletin or rolipram (PDE4 inhibitor) injection, but not SR1078 (RORα/γ agonist), caused acute Per1 expression in the peripheral tissues. Thus, the present study demonstrated a novel function of nobiletin and the regulation of the peripheral circadian clock.

PDE4 inhibition attenuates non-alcoholic fatty liver disease by increasing vldl secretion in obese animals

PDE4 inhibition attenuates non-alcoholic fatty liver disease by increasing vldl secretion in obese animals

PDE5 inhibition mitigates heart failure in hyperlipidemia

PDE5 inhibitors was reported to play a protective role in both regulating lipid metabolism and reducing heart failure (HF). This study aimed to clarify the effectiveness of PDE5 inhibitors against hyperlipidemia-related HF by combining evidence from population-based study and animal models. The nationwide cohort study found that post-diagnostic use of PDE5 inhibitors was associated with a significantly lower risk of HF compared with patients who used alprostadil, especially among individuals with hyperlipidemia (adjusted HR = 0.56, 95% CI = 0.40–0.78). In animal models, sildenafil significantly recovered the cardiac structure and function induced by AAB surgery, as well as reversed liver dysfunction and ameliorated hyperlipidemia induced by HFD via reducing the level of ALT, AST and serum lipids. Lipidomic analysis identified four lipid metabolites involved in sildenafil administration, including FA 16:3, LPC O-18:1, DG24:0_18:0 and SE28:1/20:4. This study revealed the protective effect of PDE5 inhibitors against HF in hyperlipidemia, indicating the potential of being repurposed as an adjuvant for HF prevention in patients with hyperlipidemia if these findings can be further confirmed in clinical trials.

In silico exploration of antinociceptive activity of 1,4-benzodiazepines: Molecular docking on α1 A-adrenoceptor, and phosphodiesterase 4

Recently, scientists have established that several benzodiazepines were found to enhance the activation of a cAMP response element pathway by α1A-adrenergic receptors, but this effect was attributed to off-target inhibition of phosphodiesterases 4. The study explores the pain-relief potential of 1,4-benzodiazepines using in silico methods, focusing on their interaction with α1A-adrenoceptors (α1-AR) and phosphodiesterase 4 (PDE4). AutoDock Vina-1.2.5 and Glide (Schrödinger Suite) (2023-2) were used to calculate the binding affinities and determine the features of their interactions by the molecular docking method; PlayMolecule software was used to perform molecular dynamics. Propoxazepam exhibits moderate free binding energy for α1A-adrenoceptors, as indicated by its average molecular mechanics/generalized Born surface area (MMGBSA) and Glide Score values. Compared to propoxazepam, 3-hydroxypropoxazepam has enhanced predicted affinity values for the alpha 1A adrenergic receptor, primarily due to the hydroxyl group, which facilitates the formation of additional hydrogen bonds. Propoxazepam, along with its metabolite 3-hydroxypropoxazepam, demonstrates promising interactions with PDE4A, characterized by notably low predicted free binding energy MMGBSA and strong binding affinity computed via AutoDock Vina. Among other ligands, propoxazepam demonstrates the lowest MMGBSA value with PDE4A (phosphodiesterase 4A). The best predicted binding scores of interaction with phosphodiesterase 4 is observed for propoxazepam with PDE4B (phosphodiesterase 4B) -10.3 kcal/mol, according to AutoDock Vina. Propoxazepam and its derivative 3-hydroxypropoxazepam interact with the active sites of PDE4B and PDE4D (phosphodiesterase 4 B) via a “hydrophobic clamp”, a typical binding mode for PDE inhibitors, which relies on crucial hydrophobic interactions. Binding of propoxazepam and its metabolite 3-hydroxypropoxazepa to PDE4B reduces the fluctuations of M-pocket residues and supports the conclusion that ligand binding stabilizes the protein structure of PDE4B. The MMGBSA method predicts that propoxazepam and 3-hydroxypropoxazepam have the most favourable predicted binding energies with PDE4D (2FMO). Since 1,4-benzodiazepines bind to phosphodiesterase 4 similarly to its inhibitors, this may support the hypothesis that benzodiazepines may affect α1-AR by inhibiting PDE4. The study of the binding mechanisms of 1,4-benzodiazepines with phosphodiesterase 4 and alpha-1A adrenoceptors helps to expand the understanding of the analgesic and anti-inflammatory effect of benzodiazepines associated with these proteins, which can be taken into account in the development of new analgesic and anti-inflammatory agents.

Rolipram impacts on redox homeostasis and cellular signaling in an experimental model of abdominal aortic aneurysm

IntroductionCyclic nucleotide phosphodiesterases (PDEs) of the PDE4 subfamily are responsible for the hydrolysis and subcellular compartmentalization of cAMP, a second messenger that modulates vascular functionality. We had shown that PDE4B is induced in abdominal aortic aneurysms (AAA) and that PDE4 inhibition by rolipram limits experimental aneurysms. In this study we have delved into the mechanisms underlying the beneficial effect of rolipram on AAA. MethodsAAA were induced in ApoE−/− mice by angiotensin II (Ang II) infusion. Aneurysm formation was evaluated by ultrasonography. The expression of enzymes involved in redox homeostasis was analyzed by real-time RT-PCR and the activation of signaling pathways by Western blot. ResultsInduction of PDE4B in human AAA has been confirmed in a second cohort of patients. In Ang II-infused ApoE−/− mice, rolipram increased the percentage of animals free of aneurysms without affecting the percentage of aortic ruptures. Quantitative analyses determined that this drug significantly attenuated aortic collagen deposition. Additionally, rolipram reduced the increased Nox2 expression triggered by Ang II, exacerbated Sod1 induction, and normalized Sod3 expression. Likewise, PDE4 inhibition decreased the activation of both ERK1/2 and the canonical Wnt pathway, while AKT activity was not altered. ConclusionsThe inhibition of PDE4 activity modulates the expression of enzymes involved in redox homeostasis and affects cell signaling pathways involved in the development of AAA.

Design, synthesis, molecular docking, and molecular dynamic studies of novel quinazoline derivatives as phosphodiesterase 7 inhibitors.

Introduction: Phosphodiesterase 7 (PDE7) is a high-affinity cyclic AMP (cAMP)-specific PDE that is expressed in immune and proinflammatory cells. In this work, we explore the possibility that selective small molecule inhibitors of this enzyme family could provide a novel approach to alleviate the inflammation that is associated with many inflammatory diseases. Methods: A series of novel substituted 4-hydrazinoquinazoline derivatives and fused triazoloquinazolines were designed, synthesized, and evaluated in vitro for their PDE7A inhibition activities, in comparison with Theophylline, a non-selective PDE inhibitor, and BRL50481, a selective PDE7A inhibitor. This series of novel quinazoline derivatives were synthesized via multi-step reactions. The reaction sequence began with selective monohydrazinolysis of compounds 2a,b to give 3a,b. Schiff bases 4a-h were synthesized by the reaction of the quinazolylhydrazines 3a,b with various substituted aromatic aldehydes. The reaction of 4a-h with bromine in acetic acid, in turn, gave fused triazoloquinazolines 5a-h. These compounds were characterized by satisfied spectrum analyses mainly including 1HNMR, 13CNMR, and MS together with elemental analyses. Results and discussion: The results of in vitro PDE7A inhibition activity clearly indicated that compounds 4b, 4g, 5c, and 5f exhibited good potency. Molecular docking and molecular dynamic simulation studies further supported our findings and provided the basis of interaction in terms of conventional hydrogen bonds and π-π stacking patterns. The present results lay the groundwork for developing lead compounds with improved phosphodiesterase seven inhibitory activities.

Effects of PDE-3 inhibition in persistent post-traumatic headache: evidence of cAMP-dependent signaling

BackgroundPhosphodiesterase 3 (PDE-3) inhibition have been implicated in the neurobiologic underpinnings of migraine. Considering the clinical similarities between migraine and persistent post-traumatic headache (PPTH), we aimed to ascertain whether PDE-3 inhibition can elicit migraine-like headache in persons with PPTH.MethodsWe tested cilostazol, which inhibits PDE-3, in a randomized, double-blind, placebo-controlled, two-way crossover study involving persons with PPTH attributed to mild traumatic brain injury. The randomized participants were allocated to receive oral administration of either 200-mg cilostazol or placebo (calcium tablet) on two separate experiment days. The primary end point was the incidence of migraine-like headache during a 12-hour observation window post-ingestion. The secondary endpoint was the area under the curve (AUC) for reported headache intensity scores during the same observation window.ResultsTwenty-one persons underwent randomization and completed both experiment days. The mean participants’ age was 41.4 years, and most (n = 17) were females. During the 12-hour observation window, 14 (67%) of 21 participants developed migraine-like headache post-cilostazol, in contrast to three (14%) participants after placebo (P =.003). The headache intensity scores were higher post-cilostazol than after placebo (P <.001).ConclusionsOur results provide novel evidence showing that PDE-3 inhibition can elicit migraine-like headache in persons with PPTH. Given that PDE-3 inhibition increases intracellular cAMP levels, our findings allude to the potential therapeutic value of targeting cAMP-dependent signaling pathways in the management of PPTH. Further investigations are imperative to substantiate these insights and delineate the importance of cAMP-dependent signaling pathways in the neurobiologic mechanisms underlying PPTH.ClinicalTrials.gov IdentifierNCT05595993.

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 Long-Acting Lyotropic Liquid Crystalline Implant Promotes the Drainage of Macromolecules by Brain-Related Lymphatic System in Treating Aged Alzheimer's Disease.

Numerous evidence has demonstrated that the brain is not an immune-privileged organ but possesses a whole set of lymphatic transport system, which facilitates the drainage of harmful waste from brains to maintain cerebral homeostasis. However, as individuals age, the shrinkage and dysfunction of meningeal and deep cervical lymphatic networks lead to reduced waste outflow and elevated neurotoxic molecules deposition, further inducing aging-associated cognitive decline, which act as one of the pathological mechanisms of Alzheimer's disease. Consequently, recovering the function of meningeal and deep cervical lymph node (dCLNs) networks (as an important part of the brain waste removal system (BWRS)) of aged brains might be a feasible strategy. Herein we showed that the drug brain-entering efficiency was highly related to administration routes (oral, subcutaneous, or dCLN delivery). Besides, by injecting a long-acting lyotropic liquid crystalline implant encapsulating cilostazol (an FDA-approved selective PDE-3 inhibitor) and donepezil hydrochloride (a commonly used symptomatic relief agent to inhibit acetylcholinesterase for Alzheimer's disease) near the deep cervical lymph nodes of aged mice (about 20 months), an increase of lymphatic vessel coverage in the nodes and meninges was observed, along with accelerated drainage of macromolecules from brains. Compared with daily oral delivery of cilostazol and donepezil hydrochloride, a single administered dual drugs-loaded long-acting implants releasing for more than one month not only elevated drug concentrations in brains, improved the clearing efficiency of brain macromolecules, reduced Aβ accumulation, enhanced cognitive functions of the aged mice, but improved patient compliance as well, which provided a clinically accessible therapeutic strategy toward aged Alzheimer's diseases.

Abstract 565: PDE7 modulates EMT, cells morphology and mitochondrial cristae in high grade serous ovarian cancer

Abstract Background: Due to the acquisition of chemoresistant phenotype by epithelial ovarian cancer (EOC) cells and, consequently, disease relapse, the identification of novel therapeutic strategies is urgent. Herein, we targeted phosphodiesterase 7A (PDE7A) in EOC cells, based on data derived from RNA-sequencing assays comparing high-grade serous ovarian carcinoma (HGSOC) and fallopian tube samples. Methods: To understand the role of PDE inhibition, we evaluated the effects of its inhibitor BRL50481 alone or in combination with paclitaxel (PTX) on untreated A2780 EOC cells and multi-resistant high grade serous ovarian cancer (HGSOC) OVCAR3 cells. To do so, we pursued with the: validation of data obtained by high throughput RNA sequencing assays using qRT-PCR; evaluation of PDE7 expression in normal and EOC cells, as well as in normal Fallopian tube cells by qRT-PCR; immunoblotting; metabolic cell viability (MCV) by MTT assays; cytokine dosage by qRT-PCR and ELISA; scanning electron microscopy; transmission electron microscopy; statistical analysis (GraphPad software). Results: Drug-sensitive A2780 cells, but not OVCAR3 cells, exhibited lower MCV when treated with the PDE7 inhibitor; however, the combinatory therapy decreased MCV in both cell lines. Of clinical relevance, pre-treatment of A2780 and OVCAR3 with the PDE7 inhibitor BRL50481 followed by PTX lowered its IC50 by 103- and 625-fold, respectively. While the phosphatidylinositol 3-kinase (PI3K)/protein kinase B(AKT)/mammalian target of rapamycin (mTOR) pathway was inhibited in both cell lines, the pro-apoptotic protein Bcl-2 Associated X-protein (BAX) was overexpressed in A2780 cells only. Analysis of mRNA and protein expression in OVCAR3 pretreated with BRL50481 showed a 2-fold increase in IL-6 cytokine expression. Pre-treatment of OVCAR3 with BRL50481 followed by the combination of BRL50481 and PTX inhibited the expression of vimentin and Octamer-binding transcription factor 4 (OCT4) by 2-fold. BRL50481 promoted changes in EOC cells morphology and mitochondrial cristae. Conclusions: Altogether, our data led us to postulate that inhibition of PDE7 in EOC cells, specifically in those presenting the chemoresistant phenotype, is a promising strategy to fight this yet highly lethal disease. Citation Format: Leticia B. A. Rangel, Nayara Gusmão Tessarollo, Isabella dos Santos Guimarães, Diandra Zipinotti dos Santos, Taciane Barbosa Henriques, Marcele Lorentz de Souza, Leide Laura Figueiredo Maciel, João Carlos Aquino Almeida, Tatiana Massariol Pimenta, Josiany Carlos de Souza, Ranna Batista Wanzeler, Barbara Silva Martins, Solenny Maria Silva Butzene, Jose Matheus Simões Padilha. PDE7 modulates EMT, cells morphology and mitochondrial cristae in high grade serous ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 565.

Abstract P116: Exploring The Cardioprotective Potential Of Roflumilast (pde-4 Inhibitor) Against Experimental Epirubicin-induced Cardiotoxicity.

Introduction: Cardiotoxicity is an important side effect of the treatment of a malignant tumour with Anthracyclines. The anthracycline family drug epirubicin (EPI) is one of the most potent chemotherapeutic agents for treating a range of solid and hematologic malignant tumours. However, its anti-tumor efficacy is dose-dependent, and the development of cardiac-toxicities limits its clinical use. In various Pharmacological Studies Roflumilast (ROF), a PDE-4 Inhibitor has been shown a Neuroprotective and Cardioprotective response but its role in EPI-induced cardiotoxicity and the underlying mechanisms has never been Evaluated. Hypothesis: The Study hypothesized that Roflumilast exerts cardioprotection against EPI-induced cardiotoxicity through attenuating cardiac mitochondrial dysfunction and inflammatory markers. Methods: Wistar rats of either sex were employed into 4 groups 3 groups comprised 7 animals while the control group had 5 animals, EPI-treated rats were intraperitoneally injected with 10 mg/kg for 1 day, while control rats were on normal diet. EPI+ROF (Low Dose) treated rats were intraperitoneally injected with 10 mg/kg of EPI for 1 day and 1mg/kg of ROF via oral gavage for 7 days. While in the higher dose of EPI+ROF treated rats were intraperitoneally injected with 10 mg/kg of EPI for 1 day and 2mg/kg of ROF via oral gavage for 7 days. The rat hearts were rapidly removed to determine cardiac mitochondrial functions and various cardiac biomarkers. Results: EPI induced significantly excessive mitochondrial Oxidative Stress, increased tissue TBARS and decreased levels of SOD and GSH. Conversely, a 7-day treatment with ROF (1mg/kg/day , p.o .) and ROF (2mg/kg/day, p.o .) significantly reduced TBARS levels while increasing SOD and GSH concentrations. The levels of TNF-α, CK-MB AST, ALT, and LDH were noted to be markedly increased in EPI-induced rats. While treatment with ROF (1mg/kg/day, p.o., 7 days ) and ROF (2mg/kg/day, p.o., 7 days) showed significantly decreased levels of TNF-α, CK-MB AST, ALT, LDH. Conclusion: In the current investigation, it can be concluded that administration of EPI leads to Oxidative Stress, Inflammation and Cardiotoxicity. Treatment with the ROF 2mg/kg showed cardioprotective potential by significantly decreasing inflammatory markers, oxidative stress parameters and cardiotoxic parameters. Our findings suggest that ROF protects the heart from EPI-induced cardiotoxicity, and it may serve as a guide for future cardioprotective research strategies.

Identification of Dihydrobenzofuran Neolignans as Novel PDE4 Inhibitors and Evaluation of Antiatopic Dermatitis Efficacy in DNCB-Induced Mice Model.

Atopic dermatitis is a chronic relapsing skin disease characterized by recurrent, pruritic, localized eczema, while PDE4 inhibitors have been reported to be effective as antiatopic dermatitis agents. 3',4-O-dimethylcedrusin (DCN) is a natural dihydrobenzofuran neolignan isolated from Magnolia biondii with moderate potency against PDE4 (IC50 = 3.26 ± 0.28 μM) and a binding mode similar to that of apremilast, an approved PDE4 inhibitor for the treatment of psoriasis. The structure-based optimization of DCN led to the identification of 7b-1 that showed high inhibitory potency on PDE4 (IC50 = 0.17 ± 0.02 μM), good anti-TNF-α activity (EC50 = 0.19 ± 0.10 μM), remarkable selectivity profile, and good skin permeability. The topical treatment of 7b-1 resulted in the significant benefits of pharmacological intervention in a DNCB-induced atopic dermatitis-like mice model, demonstrating its potential for the development of novel antiatopic dermatitis agents.

Roflumilast inhibits tumor growth and migration in STK11/LKB1 deficient pancreatic cancer

Pancreatic cancer is a malignant tumor of the digestive system. It is highly aggressive, easily metastasizes, and extremely difficult to treat. This study aimed to analyze the genes that might regulate pancreatic cancer migration to provide an essential basis for the prognostic assessment of pancreatic cancer and individualized treatment. A CRISPR knockout library directed against 915 murine genes was transfected into TB 32047 cell line to screen which gene loss promoted cell migration. Next-generation sequencing and PinAPL.py- analysis was performed to identify candidate genes. We then assessed the effect of serine/threonine kinase 11 (STK11) knockout on pancreatic cancer by wound-healing assay, chick agnosia (CAM) assay, and orthotopic mouse pancreatic cancer model. We performed RNA sequence and Western blotting for mechanistic studies to identify and verify the pathways. After accelerated Transwell migration screening, STK11 was identified as one of the top candidate genes. Further experiments showed that targeted knockout of STK11 promoted the cell migration and increased liver metastasis in mice. Mechanistic analyses revealed that STK11 knockout influences blood vessel morphogenesis and is closely associated with the enhanced expression of phosphodiesterases (PDEs), especially PDE4D, PDE4B, and PDE10A. PDE4 inhibitor Roflumilast inhibited STK11-KO cell migration and tumor size, further demonstrating that PDEs are essential for STK11-deficient cell migration. Our findings support the adoption of therapeutic strategies, including Roflumilast, for patients with STK11-mutated pancreatic cancer in order to improve treatment efficacy and ultimately prolong survival.

Cardiac Troponin Activator CK-963 Increases Cardiac Contractility in Rats.

Novel cardiac troponin activators were identified using a high throughput cardiac myofibril ATPase assay and confirmed using a series of biochemical and biophysical assays. HTS hit 2 increased rat cardiomyocyte fractional shortening without increasing intracellular calcium concentrations, and the biological target of 1 and 2 was determined to be the cardiac thin filament. Subsequent optimization to increase solubility and remove PDE-3 inhibition led to the discovery of CK-963 and enabled pharmacological evaluation of cardiac troponin activation without the competing effects of PDE-3 inhibition. Rat echocardiography studies using CK-963 demonstrated concentration-dependent increases in cardiac fractional shortening up to 95%. Isothermal calorimetry studies confirmed a direct interaction between CK-963 and a cardiac troponin chimera with a dissociation constant of 11.5 ± 3.2 μM. These results provide evidence that direct activation of cardiac troponin without the confounding effects of PDE-3 inhibition may provide benefit for patients with cardiovascular conditions where contractility is reduced.

PKC Inhibition Improves Human Penile Vascular Function and the NO/cGMP Pathway in Diabetic Erectile Dysfunction: The Role of NADPH Oxidase.

Erectile dysfunction (ED) is a frequent and difficult-to-treat condition in diabetic men. Protein kinase C (PKC) is involved in diabetes-related vascular and cavernosal alterations. We aimed to evaluate the role of PKC in endothelial dysfunction and NO/cGMP impairment associated with diabetic ED in the human corpus cavernosum (CC) and penile resistance arteries (PRAs) and the potential mechanisms involved. Functional responses were determined in the CC and PRAs in patients with non-diabetic ED and diabetic ED undergoing penile prosthesis insertion. PKC activator 12,13-phorbol-dibutyrate (PDBu) impaired endothelial relaxations and cGMP generation in response to acetylcholine in the CC from non-diabetic ED. PDBu also impaired responses to a PDE5 inhibitor, sildenafil, in non-diabetic ED patients. Conversely, a PKC inhibitor, GF109203X, improved endothelial, neurogenic, and PDE5-inhibitor-induced relaxations and cGMP generation only in the CC in diabetic ED patients. Endothelial and PDE5-inhibitor-induced vasodilations of PRAs were potentiated only in diabetes. Improvements in endothelial function in diabetes were also achieved with a specific inhibitor of the PKCβ2 isoform or an NADPH-oxidase inhibitor, apocynin, which prevented PDBu-induced impairment in non-diabetic patients. PKC inhibition counteracted NO/cGMP impairment and endothelial dysfunction in diabetes-related ED, potentially improving response to PDE5 inhibition.