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In this work, the complex of [99mTc]tricarbonyl rolipram was labeled utilizing a [99mTc]tricarbonyl core. Many optimal parameters have been used such as substrate (100 μg), pH of the reaction mixture (pH 9), reaction time (30 min), as well as temperature (100°C), providing an optimal radiochemical purity of 97.0%. Biodistribution investigations of our radiotracer, [99mTc]tricarbonyl rolipram, were conducted on normal Swiss Albino mice. The results indicated maximum brain uptakes of 8.2 %ID/g tissue at 10 min post injection (p.i.), which cleared from the brain with time until it reached 1.90 ± 0.17% at 1 h p.i. Therefore, [99mTc]tricarbonyl rolipram complex may be an excessively bio-selective receptor-tracer for brain ulcer imaging through the phosphodiesterase-4 inhibitor. [ABSTRACT FROM AUTHOR]

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

In vitro maturation of porcine oocytes is characterized by asynchronous cytoplasmic and nuclear maturation, leading to less competent oocytes supporting embryo development. The purpose of this study was to evaluate the combined effect of rolipram and cilostamide as cyclic Adenine monophosphate (cAMP) modulators to find the maximum cAMP levels that temporarily arrest meiosis. We determined the optimal time to maintain functional gap junction communication during pre-in vitro maturation to be four hours. Oocyte competence was evaluated by the level of glutathione, reactive oxygen species, meiotic progression, and gene expression. We evaluated embryonic developmental competence after parthenogenetic activation and somatic cell nuclear transfer. The combined treatment group showed significantly higher glutathione and lower reactive oxygen species levels and a higher maturation rate than the control and single treatment groups. Cleavage and blastocyst formation rates in parthenogenetic activation and somatic cell nuclear transfer embryos were higher in two-phase in vitro maturation than in the other groups. The relative levels of BMP15and GDF9 expression were increased in two-phase in vitro maturation. Somatic cell nuclear transfer blastocysts from two-phase in vitro maturation oocytes showed a lower level of expression of apoptotic genes than the control, indicating better pre-implantation developmental competence. The combination of rolipram and cilostamide resulted in optimal synchrony of cytoplasmic and nuclear maturation in porcine in vitro matured oocytes and there by enhanced the developmental competence of pre-implantation embryos. [ABSTRACT FROM AUTHOR]

Diabetic neuropathy (DN) is the most challenging microvascular complication of diabetes and there is no suitable treatment for it, so the development of new agents to relieve DN is urgently needed. Since oxidative stress and inflammation play an essential role in the development of DN, clearance of these factors are good strategies for the treatment of this disease. According to key role of cyclic adenosine monophosphate (cAMP) in the regulation of oxidative stress and inflammatory pathways, it seems that phosphodiesterase inhibitors (PDEIs) can be as novel drug targets for improving DN through enhancement of cAMP level. The aim of this study was to evaluate the effects of rolipram, a selective PDE4 inhibitor, and pentoxifylline, a general PDE inhibitor on experimental model of DN and also to determine the possible mechanisms involved in the effectiveness of these agents. We investigated the effects of rolipram (1 mg/kg) and pentoxifylline (100 mg/kg) and also combination of rolipram (0.5 mg/kg) and pentoxifylline (50 mg/kg), orally for five weeks in rats that became diabetic by STZ (55 mg/kg, i.p.). After treatments, motor function was evaluated by open-field test, then rats were anesthetized and dorsal root ganglion (DRG) neurons isolated. Next, oxidative stress biomarkers and inflammatory factors were assessed by biochemical and ELISA methods, and RT-PCR analysis in DRG neurons. Rolipram and/or pentoxifylline treatment significantly attenuated DN – induced motor function deficiency by modulating distance moved and velocity. Rolipram and/or pentoxifylline treatment dramatically increased the cAMP level, as well as suppressed DN – induced oxidative stress which was associated with decrease in LPO and ROS and increase in TAC, total thiol, CAT and SOD in DRG neurons. On the other hand, the level of inflammatory factors (TNF-α, NF-kB and COX2) significantly decreased following rolipram and/or pentoxifylline administration. The maximum effectiveness was with rolipram and/or pentoxifylline combination on mentioned factors. These findings provide novel experimental evidence for further clinical investigations on rolipram and pentoxifylline combination for the treatment of DN. [ABSTRACT FROM AUTHOR]

Background: Phosphodiesterase (PDE) inhibition has been reported to play a role in regulating gut motility, but the evidence is insufficient, and the mechanism remains unknown. The aim of this study was to investigate the possible role of phosphodiesterase‐4 (PDE4) inhibitor rolipram in water avoidance stress‐induced colonic hypermotility. Methods: A rat model of irritable bowel syndrome (IBS) with diarrhea (IBS‐D) was established by water avoidance stress (WAS). Intestinal motility was assessed by fecal pellets expulsion per hour. The cyclic adenosine monophosphate (cAMP) and nitric oxide (NO) level in colon tissue were detected using ELISA assay and the Griess test, respectively. Western blotting was performed to assess the protein level of PDE, PKA/p‐CREB, and neuronal nitric oxide synthase (nNOS) in the colon. To determine the role of rolipram in gut motility, the rats of the WAS + Rolipram and Rolipram group were injected with rolipram intraperitoneally. The colonic contractile activity was recorded with a RM6240 multichannel physiological signal system. Key Results: WAS‐induced gastrointestinal hypermotility and increased defecation in rats. After repeated stress, protein levels of PDE4 in the colon were promoted while PKA/p‐CREB and nNOS were highly decreased. cAMP content in colon tissue did not change significantly. However, NO content decreased after WAS, and rolipram partly enhanced NO in WAS‐exposed rats. In addition, intraperitoneal injection of rolipram partly inhibited the colonic motility in vivo. Meanwhile, we observed rolipram inhibited the contraction of colonic smooth muscle strips, and this inhibitory effect was abolished by Nω‐Nitro‐L‐arginine (L‐NNA), a nitric oxide synthase (NOS) inhibitor, tetrodotoxin (TTX), a blocker of neuronal voltage‐dependent Na+ channels, Rp‐Adenosine 3',5'‐cyclic monophosphorothioate triethylammonium salt hydrate (Rp‐cAMPS), an antagonist of cAMP. Conclusions and Inferences: Rolipram could relieve stress‐induced gastrointestinal hypermotility. This effect may be partly through the cAMP‐PKA‐p‐CREB pathway and NO pathway. [ABSTRACT FROM AUTHOR]

Rolipram specifically inhibits phosphodiesterase (PDE) 4, thereby preventing inactivation of the intracellular second messenger cyclic adenosine monophosphate (cAMP). Rolipram has been shown to play a neuroprotective role in some central nervous system (CNS) diseases. However, the role of PDE4 and the potential protective effect of rolipram on the pathophysiological process of intracerebral haemorrhage (ICH) are still not entirely clear. In this study, a mouse model of ICH was established by the collagenase method. Rolipram reduced brain oedema, blood–brain barrier (BBB) leakage, neuronal apoptosis and inflammatory cytokine release and improved neurological function in our mouse model of ICH. Moreover, rolipram increased the levels of cAMP and silent information regulator 1 (SIRT1) and upregulated the phosphorylation of AMP-activated protein kinase (AMPK). Furthermore, these effects of rolipram could be reversed by the SIRT1 inhibitor sirtinol. In conclusion, rolipram can play a neuroprotective role in the pathological process of ICH by activating the cAMP/AMPK/SIRT1 pathway. [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]

Sepsis is typically triggered by an overwhelming systemic inflammatory response to pathogens, and may lead to severe organ dysfunction and/or death. Sepsis consequently has a high mortality rate and a high rate of complications for survivors, despite modern medical advances. Therefore, drug identification and validation for the treatment of sepsis is of the utmost importance. As a selective phosphodiesterase-4 inhibitor, rolipram also exhibits the abilities of inhibiting multiple pro-inflammatory cytokines production in macrophages and toxin-induced inflammation in mice. However, this drug has never been studied as a sepsis treatment method. We found that rolipram significantly improves survival in mice challenged with gram-negative bacterium E. coli, CLP, or E. coli derived lipopolysaccharide. We have also found that rolipram inhibits organ damage, pro-inflammatory cytokine production, and intracellular migration of early-stage inflammatory elements. Our results also show that rolipram increases anti-inflammatory cytokine production. The protective effects of rolipram on septic mice may result from inhibition of the MAP kinase and NF-κB signaling pathways. Rolipram may therefore be a potential novel sepsis treatment, one that would bypass the time-consuming and costly drug-discovery process. [ABSTRACT FROM AUTHOR]

Abstract In this paper, we report the assembling of libraries of β -arylated short/medium/long chain-based non- α -amino acid (aminoalkanoic acid) derivatives via the Pd(II)-catalyzed, bidentate directing group 8-aminoquinoline-aided sp3 β -C-H activation/arylation method. Short/medium chain-based unnatural amino acid derivatives containing an aryl group at the β -position are promising small molecules with therapeutic properties. Thus, it is necessary to enrich the libraries of short/medium/long chain-based unnatural amino acid derivatives containing an aryl group at the β -position. Considering the importance of β -arylated short/medium/long chain-based non- α -amino acid derivatives, an inclusive attention was paid to explore the Pd(II)-catalyzed sp3 β -C-H arylation of short/medium/long chain-based non- α -amino acids. Representative synthetic transformations including a short route for the assembling of rolipram and related compounds and 3-arylated GABA derivatives such as, baclofen, phenibut and tolibut were shown using selected β -C-H arylated non-α-amino acid derivatives. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

We characterized the relationship between the plasma concentration of the phospodiesterase (PDE)-4 inhibitor GSK356278 and occupancy of the PDE4 enzyme in the brain of healthy volunteers, using the positron emission tomography (PET) tracer [11C](R)-rolipram. To this end, PET scans were acquired in eight male volunteers before and at 3 and 8 h after a single 14 mg oral dose of GSK356278. A metabolite-corrected arterial input function was used in conjunction with the dynamic PET emission data to estimate volumes of distribution (VT) from a two-tissue compartment model. The administration of GSK356278 reduced [11C](R)-rolipram whole brain VT by 17% at 3 h post-dose (p = 0.01) and by 4% at 8 h post-dose. The mean plasma Cmax was 42.3 ng/ml, leading to a PDE4 occupancy of 48% at Tmax. The in vivo affinity of GSK356278 was estimated as EC50 = 46 ± 3.6 ng/ml. We present the first report of a direct estimation of PDE4 blockade in the living human brain. In vivo affinity of GSK356278 for the PDE4, estimated in this early phase study, was combined with GSK356278 safety and tolerability data to decide on a therapeutic dose for future clinical development. [ABSTRACT FROM AUTHOR]

Early brain injury (EBI) is the primary cause of poor outcome in subarachnoid hemorrhage (SAH) patients. Rolipram, a specific phosphodiesterase-4 inhibitor which is traditionally used as an anti-depressant drug, has been recently proven to exert neuroprotective effects in several central nervous system insults. However, the role of rolipram in SAH remains uncertain. The current study was aimed to investigate the role of rolipram in EBI after SAH and explore the potential mechanism. Adult male Sprague-Dawley rats were subjected to an endovascular perforation process to produce an SAH model. Rolipram was injected intraperitoneally at 2 h after SAH with a dose of 10 mg/kg. We found that rolipram significantly ameliorated brain edema and alleviated neurological dysfunction after SAH. Rolipram treatment remarkably promoted the expression of Sirtuin 1 (SIRT1) while inhibited NF-κB activation. Moreover, rolipram significantly inhibited the activation of microglia as well as down-regulated the expression of pro-inflammatory cytokines TNF-α, IL-1ß, and IL-6. In addition, rolipram increased the expression of protective cytokine IL-10. Furthermore, rolipram significantly alleviated neuronal death after SAH. In conclusion, these data suggested that rolipram exerts neuroprotective effects against EBI after SAH via suppressing neuroinflammation and reducing neuronal loss. The neuroprotective effects of rolipram were associated with regulating the SIRT1/NF-κB pathway. Rolipram could be a novel and promising therapeutic agent for SAH treatment. [ABSTRACT FROM AUTHOR]

Introduction: The mechanism of putative cytotoxicity of 4-[3-(cyclopentyloxy)-4-methoxyphenyl]-2-pyrrolidone (rolipram), a specific phosphodiesterase-4 (PDE4) inhibitor, on glioblastoma multiforme (GBM) is almost unknown. This study aimed to investigate the role of protein kinase B (Akt) pathway in the cytotoxic effect of rolipram on human GBM U87 MG cell line and Tumor-Initiating Cells (TICs) isolated from patient's GBM specimen. Methods: TICs were characterized by using flow cytometry and quantitative real-time PCR. The cells were treated with rolipram at inhibitory concentration of 50% (IC50) in the presence or absence of SC79 (4µg/mL), a specific AKT activator, for 48 hours. The cell viability and apoptosis were measured by MTT assay and TUNEL staining, respectively. The relative expression of Phospho-Akt (Ser473), matrix metalloproteinase 2 (MMP2), and vascular endothelial growth factor A (VEGFA) were detected using Western blotting. Results: The findings showed that rolipram could suppress cell viability in both U87MG and TICs, dose-dependently. Interestingly, the rolipram-induced cytotoxicity was significantly reduced in the presence of SC79. Nevertheless, in rolipram-treated cells, the pretreatment with SC79 significantly led to increase in U87 MG cells and TICs apoptosis and decrease in viability of U87 MG cells but not TICs relative to corresponding control. In U87 MG and TICs, rolipram-induced reduction of Phospho-Akt (Ser473) and MMP2 levels were significantly suppressed by SC79. Conclusion: There is a cell type-specific mechanism of anti-proliferative action of rolipram on GBM cells. The reduction of intracellular level of MMP2 but not VEGFA by rolipram is conducted through the inhibition of Akt signal. Rolipram-induced apoptosis is mediated via Akt dependent/independent mechanisms. [ABSTRACT FROM AUTHOR]

Brain imaging is considered one of the most fruitful applications of radioisotope scanning. Rolipram, a selective phospodiesterase-4 inhibitor, has been labeled using [125I] with chloramine-T (Ch-T) as an oxidizing agent. Factors, such as the amount of substrate, pH, the amount of oxidizing agent, temperature, and the reaction time, have been systematically studied to optimize the iodination process. In addition, bio-distribution studies have indicated that the brain uptake of [125I]iodorolipram is 7.6 ± 0.33 injected dose/g organ at 10 minutes post-injection, which cleared from the brain with time until it reaches 1.30 ± 0.17% at 1 hour post-injection. Therefore, iodorolipram could be considered as a potential, new selective radiotracer for brain imaging. [ABSTRACT FROM AUTHOR]

Objective: Forskolin, an activator of adenylate cyclase and rolipram a selective inhibitor of phosphodiesterase 4, stimulate lipolysis and inhibit body weight increase by increasing cyclic adenosine monophosphate (cAMP) levels. This study was aimed to investigate the effects of them on leptin, resistin and adiponectin levels in diet induced obesity in rats. Methods: Totally 50 rats were randomly divided into five groups. The Group I was fed with standard pellet diet and the other groups were fed with high-fat diet for 10 weeks. During the last two weeks of the study, group II continued to fed with high-fat diet whereas group III, group IV and group V were administered forskolin, rolipram and forskolin plus rolipram respectively by orogastric tube in addition to their high-fat diet. Then, rats were sacrificed and serum leptin, resistin and adiponectin levels were measured. Results: Although adiponectin levels of group II (p<0.001 for adiponectin, p<0.01 for leptin), group III (p<0.01), group V (p<0.05) were significantly decreased, leptin levels were significantly increased compared to that of the group I. Also, leptin levels of group IV were significantly reduced compared to those of group II (p<0.05). There were no significant differences between resistin levels of the groups. Conclusion: Our results showed that rolipram prevented any alteration in the levels of leptin and adiponectin in addition to its effect on cAMP levels. However, forskolin and rolipram showed no effect on resistin levels of the groups. The underlying mechanism of these findings is not known and needs to be more investigated. [ABSTRACT FROM AUTHOR]

Rationale: Withdrawal symptoms stand as a core feature of alcohol dependence. Our previous results have shown that inhibition of phosphodiesterase-4 (PDE4) decreased ethanol seeking and drinking in alcohol-preferring rodents. However, little is known about whether PDE4 is involved in ethanol abstinence-related behavior. Objective: The objective of this study was to characterize the role of PDE4 in the development of anxiety- and depressive-like behavior induced by abstinence from ethanol exposure in different animal models. Methods: Using three rodent models of ethanol abstinence, we examined the effects of rolipram, a prototypical, selective PDE4 inhibitor, on (1) anxiety-like behavior induced by repeated ethanol abstinence in the elevated plus maze test in fawn-hooded (FH/Wjd) rats, (2) anxiety-like behavior in the open-field test and light-dark transition test following acute ethanol abstinence in C57BL/6J mice, and (3) anxiety- and depressive-like behavior induced by protracted ethanol abstinence in the elevated plus maze, forced-swim, and tail-suspension tests in C57BL/6J mice. Results: Pretreatment with rolipram (0.1 or 0.2 mg/kg) significantly increased entries and time spent in the open arms of the elevated plus maze test in rats with repeated ethanol abstinence. Similarly, in mice with acute ethanol abstinence, administration of rolipram (0.25 or 0.5 mg/kg) dose-dependently increased the crossings in the central zone of the open-field test and duration and transitions on the light side of the light-dark transition test, suggesting anxiolytic-like effects of rolipram. Consistent with these, chronic treatment with rolipram (0.1, 0.3, or 1.0 mg/kg) increased entries in the open arms of the elevated plus maze test; it also reduced the increased duration of immobility in both the forced-swim and tail-suspension tests in mice after protracted ethanol abstinence, suggesting antidepressant-like effects of rolipram. Conclusions: These results provide the first demonstration for that PDE4 plays a role in modulating the development of negative emotional reactions associated with ethanol abstinence, including anxiety and depression. PDE4 inhibitors may be a novel class of drugs for treatment of alcoholism. [ABSTRACT FROM AUTHOR]

Objective: Forskolin, an activator of adenylate cyclase and rolipram a selective inhibitor of phosphodiesterase 4, stimulate lipolysis and inhibit body weight increase by increasing cyclic adenosine monophosphate (cAMP) levels. This study was aimed to investigate the effects of them on leptin, resistin and adiponectin levels in diet induced obesity in rats. Methods: Totally 50 rats were randomly divided into five groups. The Group I was fed with standard pellet diet and the other groups were fed with high-fat diet for 10 weeks. During the last two weeks of the study, group II continued to fed with high-fat diet whereas group III, group IV and group V were administered forskolin, rolipram and forskolin plus rolipram respectively by orogastric tube in addition to their high-fat diet. Then, rats were sacrificed and serum leptin, resistin and adiponectin levels were measured. Results: Although adiponectin levels of group II (p<0.001 for adiponectin, p<0.01 for leptin), group III (p<0.01), group V (p<0.05) were significantly decreased, leptin levels were significantly increased compared to that of the group I. Also, leptin levels of group IV were significantly reduced compared to those of group II (p<0.05). There were no significant differences between resistin levels of the groups. Conclusion: Our results showed that rolipram prevented any alteration in the levels of leptin and adiponectin in addition to its effect on cAMP levels. However, forskolin and rolipram showed no effect on resistin levels of the groups. The underlying mechanism of these findings is not known and needs to be more investigated. [ABSTRACT FROM AUTHOR]

Abstract: The aim of the present study was to investigate the mode of action of luteolin on phisphodiesterase (PDE) 1–5, and the possible adverse effects, such as nausea, vomiting, and gastric hypersecretion, determined by replacing [3H]-rolipram binding and reversing xylazine/ketamine-induced anesthesia. The reversing effect was reported to occur through a presynaptic α2-adrenoceptor inhibition and trigger vomiting in ferrets. In contrast, clonidine, an α2-adrenoceptor agonist, prevented emesis induced by PDE4 inhibitors in ferrets. According to the Lineweaver–Burk analysis, luteolin (3–30μM) competitively inhibited PDE1–5 activities, with K i values of 15.0, 6.4, 13.9, 11.1, and 9.5μM, respectively, which did not significantly differ from each other. The equilibrium dissociation constant (K d) and maximal density (B max) for [3H]-rolipram binding at high-affinity rolipram binding sites of guinea pig brain cell membranes were 10.1nM and 3.7pmol/g of tissue, respectively. The EC50 (PDE4H) values of luteolin and Ro 20-1724, a selective PDE4 inhibitor, for displacing 2nM [3H]-rolipram binding were 11.2μM and 45.6nM, respectively. The therapeutic (PDE4H/PDE4L) ratios of luteolin and Ro 20-1724 were calculated to be 0.6, and 0.004, respectively. Both luteolin (10–30μmol/kg, s.c.) and Ro 20-1724 (0.1–1μmol/kg, s.c.) significantly reversed the xylazine/ketamine-induced anesthesia in mice. Although luteolin non-selectively and competitively inhibited PDE1–5, only PDE4 inhibition contributed to a reversing effect. In conclusion, because of the low therapeutic (PDE4H/PDE4L) ratio of luteolin, the gastrointestinal adverse effects such as nausea, vomiting and gastric hypersecretion should be carefully monitored, whenever luteolin is used for treating allergies, asthma or chronic obstructive pulmonary disease. [Copyright &y& Elsevier]

Among the complex pathophysiological events following spinal cord injury (SCI), one of the most important molecular level consequences is a dramatic reduction in neuronal cyclic adenosine monophosphate (cAMP) levels. Many studies shown that rolipram (Rm), a phosphodiesterase IV inhibitor, can protect against secondary cell death, reduce inflammatory cytokine levels and immune cell infiltration, and increase white matter sparing and functional improvement. Previously, we developed a polymeric micelle nanoparticle, poly(lactide-co-glycolide)-graft-polyethylenimine (PgP), for combinatorial delivery of therapeutic nucleic acids and drugs for SCI repair. In this study, we evaluated PgP as an Rm delivery carrier for SCI repair. Rolipram's water solubility was increased ∼6.8 times in the presence of PgP, indicating drug solubilization in the micelle hydrophobic core. Using hypoxia as an in vitro SCI model, Rm-loaded PgP (Rm-PgP) restored cAMP levels and increased neuronal cell survival of cerebellar granular neurons. The potential efficacy of Rm-PgP was evaluated in a rat compression SCI model. After intraspinal injection, 1,1′-dioctadecyl-3,3,3′,3′-tetramethyl indotricarbocyanine Iodide-loaded PgP micelles were retained at the injection site for up to 5 days. Finally, we show that a single injection of Rm-PgP nanoparticles restored cAMP in the SCI lesion site and reduced apoptosis and the inflammatory response. These results suggest that PgP may offer an efficient and translational approach to delivering Rm as a neuroprotectant following SCI. [ABSTRACT FROM AUTHOR]

Despite the introduction of new therapies for multiple myeloma (MM), many patients are still dying from this disease and novel treatments are urgently needed. We have designed a novel hybrid molecule, called NEO214, that was generated by covalent conjugation of the natural monoterpene perillyl alcohol (POH), an inducer of endoplasmic reticulum (ER) stress, to rolipram (Rp), an inhibitor of phosphodiesterase-4 (PDE4). Its potential anticancer effects were investigated in a panel of MM cell lines. We found that NEO214 effectively killed MM cells in vitro with a potency that was over an order of magnitude stronger than that of its individual components, either alone or in combination. The cytotoxic mechanism of NEO214 involved severe ER stress and prolonged induction of CCAAT/enhancer-binding protein homologous protein (CHOP), a key pro-apoptotic component of the ER stress response. These effects were prevented by salubrinal, a pharmacologic inhibitor of ER stress, and by CHOP gene knockout. Conversely, combination of NEO214 with bortezomib, a drug in clinical use for patients with MM, resulted in synergistic enhancement of MM cell death. Combination with the adenylate cyclase stimulant forskolin did not enhance NEO214 impact, indicating that cyclic adenosine 30,50-monophosphate (AMP) pathways might play a lesser role. Our study introduces the novel agent NEO214 as a potent inducer of ER stress with significant anti-MM activity in vitro. It should be further investigated as a potential MM therapy aimed at exploiting this tumor's distinct sensitivity to ER stress. [ABSTRACT FROM AUTHOR]

Phosphodiesterase-4 (PDE4) inhibitors have recently been introduced to the treatment of COPD and psoriatic arthritis. Microsomal prostaglandin E synthase-1 (mPGES-1) is an inducible enzyme synthesizing PGE2, the most abundant prostanoid related to inflammation and inflammatory pain. mPGES-1 is a potential drug target for novel anti-inflammatory treatments aiming at an improved safety profile as compared to NSAIDs. Here we investigated the effect of the PDE4 inhibitor rolipram on the expression of mPGES-1 in macrophages; and a potential mediator role in the process for MAP kinase phosphatase-1 (MKP-1) which is an endogenous factor limiting the activity of the proinflammatory MAP kinases p38 and JNK. The expression of mPGES-1 was decreased, whereas that of MKP-1 was enhanced by rolipram in wild-type murine macrophages. Interestingly, rolipram did not reduce mPGES-1 expression in peritoneal macrophages from MKP-1-deficient mice. A reduced phosphorylation of JNK, but not p38 MAP kinase, was specifically associated with the decreased expression of mPGES-1. Accordingly, mPGES-1 expression was suppressed by JNK but not p38 inhibitor. These findings underline the significance of the increased MKP-1 expression and decreased JNK phosphorylation associated with the downregulated expression of mPGES-1 by PDE4 inhibitors in inflammation. [ABSTRACT FROM AUTHOR]

Aims Glioblastoma cancer stem-like cells (GCSCs) promote themselves proliferation by secreting the vascular endothelial growth factor A (VEGF A ) in an autocrine manner, positively regulated by phosphodiesterase IV (PDE4). In the current study, we investigated the putative cytotoxic effect of bevacizumab, a VEGF A blocker, alone and in combination with a specific inhibitor of PDE4 called rolipram on GCSCs isolated from human surgical tumor specimen with a focus on PI3K/AKT pathway. Main methods CD133 +/CD15 + GCSCs were characterized by flow cytometry and expanded in a serum-free primary culture system. The cell survival, apoptosis, and protein expression values were measured using MTT assay, TUNEL staining and western blot, successively. Intracellular cAMP and free secreted VEGF A levels were assessed by cAMP enzyme immunoassay and ELISA, respectively. Key findings Bevacizumab suppressed GCSCs survival with IC 50 ~ 6.5 μg/ml and enhanced the levels of apoptosis, p53 and cleaved-caspase3 along with a decrease in free VEGF A levels and ERKs activation. However, there was no significant modulation of AKT phosphorylation on serine 473, the intracellular PDE4A, VEGF A and cAMP levels. More cytotoxicity in co-treated cells coupled with a more substantial decline in the free VEGF A levels and a greater increase in the quantities of p53 and cleaved-caspase3 compared to those treated with bevacizumab alone. Co-treatment reduced phospho-AKT, endogenous VEGF A and PDE4A values but elevated cAMP levels. Significance This study highlighted a booster cytotoxic effect of combined rolipram and bevacizumab treatment on the GCSCs primary culture, suggesting that this approach is warranted in treatment of GBMs overexpressing VEGF A and PDE4A. [ABSTRACT FROM AUTHOR]

In cells transfected to express wild-type PDE4A4 cAMP phosphodiesterase (PDE), the PDE4 selective inhibitor rolipram caused PDE4A4 to relocalise so as to form accretion foci. This process was followed in detail in living cells using a PDE4A4 chimera formed with Green Fluorescent Protein (GFP). The same pattern of behaviour was also seen in chimeras of PDE4A4 formed with various proteins and peptides, including LimK, RhoC, FRB and the V5-6His tag. Maximal PDE4A4 foci formation, occurred over a period of about 10 h, was dose-dependent on rolipram and was reversible upon washout of rolipram. Inhibition of protein synthesis, using cycloheximide, but not PKA activity with H89, inhibited foci generation. Foci formation was elicited by Ro20–1724 and RS25344 but not by either Ariflo® or RP73401, showing that not all PDE4 selective inhibitors had this effect. Ariflo® and RP73401 dose-dependently antagonised rolipram-induced foci formation and dispersed rolipram pre-formed foci as did the adenylyl cyclase activator, forskolin. Foci formation showed specificity for PDE4A4 and its rodent homologue, PDE4A5, as it was not triggered in living cells expressing the PDE4B2, PDE4C2, PDE4D3 and PDE4D5 isoforms as GFP chimeras. Altered foci formation was seen in the Δb-LR2-PDE4A4 construct, which deleted a region within LRZ, showing that appropriate linkage between the N-terminal portion of PDE4A4 and the catalytic unit of PDE4A4 was needed for foci formation. Certain single point mutations within the PDE4A4 catalytic site (His505Asn, His506Asn and Val475Asp) were shown to ablate foci formation but still allow rolipram inhibition of PDE4A4 catalytic activity. We suggest that the binding of certain, but not all, PDE4 selective inhibitors to PDE4A4 induces a conformational change in this isoform by ‘inside-out’ signalling that causes it to redistribute in the cell. Displacing foci-forming inhibitors with either cAMP or inhibitors that do not form foci can antagonise this effect. Specificity of this effect for PDE4A4 and its homologue PDE4A5 suggests that interplay between the catalytic site and the unique N-terminal region of these isoforms is required. Thus, certain PDE4 selective inhibitors may exert effects on PDE4A4 that extend beyond simple catalytic inhibition. These require protein synthesis and may lead to redistribution of PDE4A4 and any associated proteins. Foci formation of PDE4A4 may be of use in probing for conformational changes in this isoform and for sub-categorising PDE4 selective inhibitors. [Copyright &y& Elsevier]

Cognitive impairment, anxiety- and depressive-like symptoms are well recognized outcome of cerebral ischemia in clinical and preclinical settings. Rolipram, a phosphodiesterase-4 (PDE-4) inhibitor, improves cognition and produces anxiolytic- and antidepressant-like effects in rodents. Rolipram also exerts anti-inflammatory effects and enhances survival of newborn hippocampal neurons in mice subjected to transient global cerebral ischemia. Here, we evaluated the effects of chronic rolipram treatment in mice subjected to transient global brain ischemia. C56B6/7 mice were subjected to bilateral common carotid artery occlusion (BCCAO) and were then tested in a multi-tiered behavioral battery including the elevated zero maze (EZM), open field (OF), object location test (OLT), and forced swim test (FST). We also investigated the effects of rolipram on hippocampal neurodegeneration and the expression of the neuronal plasticity markers doublecortin (DCX) and microtubule-associated protein (MAP-2). Ischemic mice exhibited memory deficits OLT, higher levels of anxiety EZM and behavioral despair FST. BCCAO caused neuronal loss in the CA3 hippocampal subfield and basolateral amygdala (BLA). In the hippocampus of BCCAO mice, a disrupted neuronal plasticity was evidenced by decreased DCX expression. Chronic treatment with rolipram attenuated the behavioral effects of BCCAO. Rolipram also decreased neurodegeneration in the CA3 while it increased dendritic arborization of DCX-immunoreactive (DCX-IR) neurons and microtubule associate MAP-2 expression in the hippocampus of BCCAO mice. These data suggest that chronic inhibition of PDE-4 can be a useful therapeutic strategy to improve the emotional and cognitive outcomes of transient global cerebral ischemia. [ABSTRACT FROM AUTHOR]

Rolipram, a phosphodiesterase-4 inhibitor, can activate the cyclic adenosine monophosphate (cAMP)/cAMP-responsive element binding protein (CREB) pathway to facilitate functional recovery following ischemic stroke. However, to date, the effects of rolipram on angiogenesis and cerebral ischemia-induced neuronal apoptosis are yet to be fully elucidated. In this study, the aim was to reveal the effect of rolipram on the angiogenesis and neuronal apoptosis following brain cerebral ischemia. Rat models of ischemic stroke were established following transient middle cerebral artery occlusion and rolipram was administered for three, seven and 14 days. The results were examined using behavioral tests, triphenyl tetrazolium chloride staining, immunostaining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) to evaluate the effects of rolipram therapy on functional outcome, angiogenesis and apoptosis. Western blot analysis was used to show the phosphorylated- (p-)CREB protein level in the ischemic hemisphere. The rolipram treatment group exhibited a marked reduction in infarct size and modified neurological severity score compared with the vehicle group, and rolipram treatment significantly promoted the microvessel density in the ischemic boundary region and increased p-CREB protein levels in the ischemic hemisphere. Furthermore, a significant reduction in the number of TUNEL-positive cells was observed in the rolipram group compared with the vehicle group. These findings suggest that rolipram has the ability to attenuate cerebral ischemic injury, stimulate angiogenesis and reduce neuronal apoptosis though the cAMP/CREB pathway. [ABSTRACT FROM AUTHOR]

Purpose: Pelvic irradiation for the treatment of cancer can affect normal cells, such as the rapidly proliferating spermatogenic cells of the testis, leading to infertility, a common post-irradiation problem. The present study investigated the radioprotective effect of rolipram, a specific phosphodiesterase type-IV inhibitor known to increase the expression and phosphorylation of the cyclic adenosine monophosphate response element-binding protein (CREB), a key factor for spermatogenesis, with the testicular system against pelvic irradiation. Materials and Methods: Male C57BL/6 mice were treated with pelvic irradiation (2 Gy) and rolipram, alone or in combination, and were sacrificed at 12 hours and 35 days after irradiation. Results: Rolipram protected germ cells from radiation-induced apoptosis at 12 hours after irradiation and significantly increased testis weight compared with irradiation controls at 35 days. Rolipram also ameliorated radiation-induced testicular morphological changes, such as changes in seminiferous tubular diameter and epithelial height. Additionally, seminiferous tubule repopulation and stem cell survival indices were higher in the rolipram-treated group than in the radiation group. Moreover, rolipram treatment counteracted the radiation-mediated decrease in the sperm count and mobility in the epididymis. Conclusions: These protective effects of rolipram treatment prior to irradiation may be mediated by the increase in pCREB levels at 12 hours post-irradiation and the attenuated decrease in pCREB levels in the testis at 35 days post-irradiation in the rolipram-treated group. These findings suggest that activation of CREB signaling by rolipram treatment ameliorates the detrimental effects of acute irradiation on testicular dysfunction and the related male reproductive functions in mice. [ABSTRACT FROM AUTHOR]

Purpose: ( R)-[C]rolipram and ( S)-[C]rolipram have been proposed to investigate phosphodiesterase-4 and, indirectly, cAMP-mediated signaling with PET. This study assessed binding of these tracers to phosphodiesterase-4 in canine myocardium. Procedures: Seven dogs underwent ( R)-[C]rolipram and ( S)-[C]rolipram dynamic PET imaging at baseline and with co-injection of saturating doses of ( R)-rolipram. Dual-input compartment models were applied to estimate the volumes of distribution ( V). Results: The model comprising one compartment for unmetabolized tracer and one compartment for labeled metabolites provided excellent fits to data acquired with ( S)-[C]rolipram at baseline and with both enantiomers during co-injection scans. Use of two compartments for unmetabolized ( R)-[C]rolipram at baseline was warranted according to Akaike and Schwarz criteria. V estimates obtained with these models were robust (CV ≤ 8.2%) and reproducible (CV ≤ 15%). Conclusion: An important fraction (~65%) of the V of ( R)-[C]rolipram at baseline reflects specific binding. Thus, the latter may be a useful index of phosphodiesterase-4 levels in canine myocardium. [ABSTRACT FROM AUTHOR]

Increased intracellular cyclic adenosine monophosphate (cAMP) can promote axonal elongation and facilitate neuronal repair, while decreased cAMP is associated with losses in neuronal regenerative capacity. Rolipram, which upregulates intracellular cAMP by blocking phosphodiesterase-4 (PDE4) enzyme activity, can mitigate diverse neurological disorders. In this study, we investigated whether rolipram induces neuronal differentiation of human bone marrow-mesenchymal stem cells (hBM-MSCs). Rolipram-treated MSCs (Roli-MSCs) had significantly increased expression of the neuroprogenitor proteins Nestin, Musashi, GFAP, and Sox-2. When Roli-MSCs were differentiated with neuronal induction media (Roli-dMSCs), they exhibited cell body and dendritic morphologies similar to those of neurons. The neurite number and length of Roli-dMSCs were significantly increased compared to those of differentiated MSCs (dMSCs). Compared with undifferentiated hBM-MSCs, the Roli-dMSCs and dMSCs showed significantly increased expression of the neuronal-specific marker genes Nestin, Musashi, CD133, GFAP, NF-M, MAP-2, KCNH1, KCNH5, SCN3A, and CACNA1A, and decreased expression of other lineage-specific markers Adiponectin, ALP, FABP4, and MMP13. The Roli-dMSCs also showed a higher expression of the neuronal markers Nestin, Musashi, Sox-2, NF-M, and Tuj-1 compared to those of the undifferentiated hBM-MSCs, measured by immunocytochemistry and immunoblotting assay. Thus, we have shown that rolipram ameliorates neuronal differentiation by the regulation of neuroprogenitor expression in hBM-MSCs, and rolipram treatment of MSCs may improve the therapeutic efficacy of stem cell therapy for neurodegenerative disorders. [ABSTRACT FROM AUTHOR]

Phosphodiesterase (PDE) 4 is the most prevalent PDE in the central nervous system (CNS) and catalyzes hydrolysis of intracellular cAMP, a secondary messenger. By therapeutic inhibition of PDE4, intracellular cAMP levels can be stabilized, and the symptoms of psychiatric and neurodegenerative disorders including depression, memory loss and Parkinson's disease can be ameliorated. Radiotracers targeting PDE4 can be used to study PDE4 density and function, and evaluate new PDE4 therapeutics, in vivo in a non-invasive way, as has been shown using the carbon-11 labeled PDE4 inhibitor R-(−)-rolipram. Herein we describe a small series of rolipram analogs that contain fluoro- or iodo-substituents that could be used as fluorine-18 PET or iodine-123 SPECT PDE4 radiotracers. This series was evaluated with an in vitro binding assay and a 4-(fluoromethyl) derivative of rolipram, MNI-617, was identified, with a five-fold increase in affinity for PDE4 ( Kd = 0.26 nM) over R-(−)-rolipram ( Kd = 1.6 nM). A deutero-analogue d2-[18F]MNI-617 was radiolabeled and produced in 23% yield with high (>5 Ci/µmol) specific activity and evaluated in non-human primate, where it rapidly entered the brain, with SUVs between 4 and 5, and with a distribution pattern consistent with that of PDE4. [ABSTRACT FROM AUTHOR]

Exposure to bacterial lipopolysaccharides (LPS) induces inflammatory signals in salivary glands. We investigated the regulatory role of phosphodiesterase 4 (PDE4) inhibitor rolipram on inflammatory mediators and cholinergic/adrenergic stimulation-induced intracellular Ca2+ signaling in salivary acinar and ductal cells. Submandibular gland (SMG) expressed PDE4A through 4D mRNA and PDE4 was localized in the luminal membrane of SMG. LPS induced Ca2+ signaling and ROS production in SMG. Treatment with rolipram blocked LPS-induced Ca2+ increase and ROS production. The application of histamine evoked Ca2+ signals and ROS production, which were attenuated by rolipram in SMG cells. Moreover, LPS-induced NLRP3 inflammasome and cleaved caspase-1 were inhibited by rolipram. The inhibitory role of rolipram in ROS-induced Ca2+ signaling was mainly observed in acinar cells and not in ductal cells. Rolipram also protected SMG acinar but not ductal cells from LPS-induced cell membrane damage. In the case of cholinergic/adrenergic stimulation, carbachol/isoproterenol-induced Ca2+ signals were upregulated by the treatment of rolipram in SMG. In the case of cAMP-dependent ductal bicarbonate secretion by rolipram, no effect was observed on the modulation of ductal chloride/bicarbonate exchange activity. Rolipram could suppress the inflammatory signals and could be a potential therapeutic strategy against LPS-induced inflammation to protect the salivary gland cells. [ABSTRACT FROM AUTHOR]

Antidepressant drug (R)-rolipram was readily prepared on a large scale from isovanilline via a succinct route. The key reaction was carried out using a 1 mol% loading of nickel(II)-bis[(S,S)-N,N′-dibenzylcyclohexane-1,2-diamine]Br2 complex as the catalyst. The ee% could reach to 99%, and the catalyst could be recovered and used in the next reaction cycle with high ee%. [ABSTRACT FROM AUTHOR]

Diabetics suffer from a higher risk of cognitive decline. cAMP response element-binding protein (CREB) is a transcription factor associated with memory and synaptic plasticity. Here, we investigated the molecular changes in the hippocampus correlated with diabetes associated cognitive decline (DACD) from a CREB-centered perspective in a rat model of type 2 diabetes. Furthermore, we tested the therapeutic effect of rolipram on DACD. High-fat diet and low-dose streptozocin were adopted to induce diabetes in SD rats. Results show that supplementation with rolipram for 23 days (0.5 mg/kg, once a day) improved the performance of diabetic rats in Morris water navigation task with increased level of CREB, brain-derived neurotrophic factor (BDNF), and Arc protein in the hippocampus. Rolipram, acting as an inhibitor of PDE4, was found to repair the imbalance in the CREB/BDNF/Arc pathway. This study may provide important insights into the mechanisms underlying DACD and provide new therapeutic targets for clinical treatment. [ABSTRACT FROM AUTHOR]

Diabetes damages the central nervous system, inducing cognitive dysfunction and structural changes, known as diabetic encephalopathy (DE). Some research suggests that the pathogenesis of DE may involve an inflammatory imbalance in the nervous system, along with β-amyloid deposition, similar to Alzheimer's disease. Less data have been yet provided to prove that mechanism. The aim of this study was to evaluate the influence of diabetes on the expression of TNF-α, IL-10, and cAMP response element-binding protein (CREB)/phosphorylated CREB (pCREB). Moreover, we investigated whether rolipram can improve memory, suppress the inflammatory response, and improve balance of CREB/pCREB in the hippocampus of diabetic rats. We used a 4-week high-fat diet and a low dose of streptozocin (30 mg/kg) to induce diabetes with hyperinsulinemia and hyperglycemia. Cognitive impairment was induced over a period of 4 months, and rolipram treatment was concomitantly given. Cognitive impairment was evaluated with the Morris water maze test. We also assessed expression of the pro-inflammatory cytokine TNF-α and the anti-inflammatory cytokine IL-10. We found that memory in rats with long-term diabetes was impaired. Treatment with rolipram increased expression of CREB and pCREB, reduced the inflammatory reaction (decreased TNF-α levels and increased IL-10 levels), and prevented cognitive impairment in these diabetic animals. This present study suggests that rolipram improves cognitive function by activating the CREB signaling pathway and alleviating neuroinflammation in type 2 diabetic rats. Rolipram may have therapeutic potential in DE. [ABSTRACT FROM AUTHOR]

A novel nanovesicle carrier, phosphatiosomes, was developed to enhance the targeting efficiency of phosphodiesterase 4 (PDE4) inhibitor to the lungs for treating acute lung injury (ALI) by intravenous administration. Phosphatiosomes were the basis of a niosomal system containing phosphatidylcholine (PC) and distearoylphosphatidylethanolamine polyethylene glycol (DSPE-PEG). Rolipram was used as the model drug loaded in the phosphatiosomes. Bioimaging, biodistribution, activated neutrophil inhibition, and ALI treatment were performed to evaluate the feasibility of phosphatiosomes as the lung-targeting carriers. An encapsulation percentage of > 90% was achieved for rolipram-loaded nanovesicles. The vesicle size and zeta potential of the phosphatiosomes were 154 nm and − 34 mV, respectively. Real-time imaging in rats showed a delayed and lower uptake of phosphatiosomes by the liver and spleen. Ex vivo bioimaging demonstrated a high accumulation of phosphatiosomes in the lungs. In vivo biodistribution exhibited increased lung accumulation and reduced brain penetration of rolipram in phosphatiosomes relative to the control solution. Phosphatiosomes improved the lungs/brain ratio of the drug by more than 7-fold. Interaction with pulmonary lipoprotein surfactants and the subsequent aggregation may be the mechanisms for facilitating lung targeting by phosphatiosomes. Rolipram could continue to inhibit active neutrophils after inclusion in the nanovesicles by suppressing O 2 − generation and elevating cAMP. Phosphatiosomes significantly alleviated ALI in mice as revealed by examining their pulmonary appearance, edema, myeloperoxidase (MPO) activity, and histopathology. This study highlights the potential of nanovesicles to deliver the drug for targeting the lungs and attenuating nervous system side effects. [ABSTRACT FROM AUTHOR]

Olfactory bulbectomy (OBX) model has been proposed as a well documented model of depression. Accumulated evidences suggest that cAMP selective PDE4 enzyme plays an important role in the pathophysiology of depression disorder. Moreover, PDE4 inhibitors have shown antidepressant-like effect in behavioral despair models. However, the potential of PDE4 inhibitors to produce antidepressant-like effect in OBX model and their underlying mechanism(s) has not been adequately addressed. The present study was designed to investigate the possible antidepressant-like effects and underlying mechanism of rolipram in OBX model. The effects of rolipram were measured in a battery of behavioral paradigms, including hyperactivity in open field test (OFT), anhedonia behavior in sucrose consumption test, open arm activity in elevated plus maze test (EPM) and emotional scores in hyperemotionality test. The underlying signaling mechanisms were also investigated by measuring serum corticosterone (CORT), brain-derived neurotrophic factor (BDNF) and brain oxidant/antioxidant levels. Treatment with rolipram (0.5 and 1 mg/kg, p.o., 14 days) significantly improved the behavioral anomalies (decreased the hyperactivity, open arm activity and hyperemotionality scores, whereas, increased sucrose consumption). Further, rolipram significantly decreased the CORT level and increased cAMP, pCREB and BDNF levels. Additionally, rolipram reduced oxidative–nitrosative stress markers (lipid peroxidation and nitrite levels) and restored the antioxidant enzyme level, including reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT), indicating attenuation of oxidative–nitrosative stress. Our results revealed that antidepressant-like effects of rolipram in OBX model may be mediated by modulating the hypothalamic–pituitary–adrenal (HPA) axis activity, increasing the cAMP signaling aspects and restoring the antioxidant mechanisms. [ABSTRACT FROM AUTHOR]

Clinical studies report evidence of long-term cognitive and other deficits following adjunctive chemotherapy treatment, which is often termed “chemobrain” or “chemo-fog”. The neurological bases of these impairments are poorly understood. Here, we hypothesize that systemic chemotherapy treatment causes long-term neurobehavioral deficits, and that these deficits are reversed by manipulation of cAMP by the PDE4 inhibitor, rolipram. Male han Wistar rats were treated with docetaxel (an adjunctive chemotherapeutic agent (1 mg/kg i.v.)) or control solution (ethanol/Tween 20/0.9% Saline – 5/5/90) once per week for 4 weeks. They were allowed to recover for 4 weeks, administration of rolipram (0.5 mg/kg po) or vehicle (maple syrup) then began and continued daily for 4 weeks. At the end of the treatment regime animals were tested for spatial and recognition memory deficits with the object exploration task and for depressive- and anxiety-like behavior in the forced swim test (FST) and open field exploration. We report docetaxel treatment impaired spatial memory but not object recognition memory, compared to control rats. Docetaxel-treated rats also spent significantly more time immobile than controls in the FST. Chronic rolipram treatment attenuated all of these docetaxel-associated changes, recovering spatial memory and reducing immobility. In conclusion, docetaxel-treated rats exhibit alterations in spatial memory and depressive-like behavior, which are reversed following chronic rolipram administration. These results detect long-term cognitive and mood changes following docetaxel treatment and identify PDE4 inhibition as a target treatment of neuropsychological changes associated with “chemobrain”. [ABSTRACT FROM AUTHOR]

Chemical manufacturing is conducted using either batch systems or continuous-flow systems. Flow systems have several advantages over batch systems, particularly in terms of productivity, heat and mixing efficiency, safety, and reproducibility. However, for over half a century, pharmaceutical manufacturing has used batch systems because the synthesis of complex molecules such as drugs has been difficult to achieve with continuous-flow systems. Here we describe the continuous-flow synthesis of drugs using only columns packed with heterogeneous catalysts. Commercially available starting materials were successively passed through four columns containing achiral and chiral heterogeneous catalysts to produce (R)-rolipram, an anti-inflammatory drug and one of the family of γ-aminobutyric acid (GABA) derivatives. In addition, simply by replacing a column packed with a chiral heterogeneous catalyst with another column packed with the opposing enantiomer, we obtained antipole (S)-rolipram. Similarly, we also synthesized (R)-phenibut, another drug belonging to the GABA family. These flow systems are simple and stable with no leaching of metal catalysts. Our results demonstrate that multistep (eight steps in this case) chemical transformations for drug synthesis can proceed smoothly under flow conditions using only heterogeneous catalysts, without the isolation of any intermediates and without the separation of any catalysts, co-products, by-products, and excess reagents. We anticipate that such syntheses will be useful in pharmaceutical manufacturing. [ABSTRACT FROM AUTHOR]

Hypertension (HT) is a prevailing risk factor for cognitive impairment, the most common cause of vascular dementia; yet, no possible mechanism underlying the cognitive impairment induced by hypertension has been identified so far. Inhibition of PDE-4 has been shown to increase phosphorylation of cAMP-response element binding protein in the hippocampus and enhance the memory performance. Here, we examined the effects of PDE-4 inhibitors, rolipram and roflumilast, on the impairment of learning and memory observed in hypertensive rats. We used 2k-1c hypertensive model to induce learning and memory defects. In addition, mRNA expression of PDE-4 sub-types A-D was also assessed in the hippocampus tissue. Systolic blood pressure (SBP) was measured by tail-cuff method was significantly increased in 2k-1c rats when compared to sham operated rats; this effect was reversed by clonidine, whereas, PDE-4 inhibitors did not. PDE-4 inhibitors significantly reversed time induced memory deficit in novel object recognition task (NORT). Further, the retention latency on the second day in the elevated plus maze model was significantly shortened after repeated administration of rolipram and roflumilast. Plasma and brain concentrations of rolipram, roflumilast and roflumilast N-oxide were also measured after the NORT and showed linear increase in plasma and brain concentrations. The PDE4B and PDE4D gene expression was significantly enhanced in hypertensive rats compared with sham operated however PDE4A and PDE4C remained unaltered. Repeated treatment with PDE-4 inhibitors caused down regulation of PDE4B and PDE4D in hypertensive rats. These results suggest that inhibition of PDE-4 ameliorates HT-induced impairment of learning and memory functions. [ABSTRACT FROM AUTHOR]

Objective: To investigate the impact of the phophodiesterase-4 inhibition (PD-4-I) with rolipram on hepatic integrity in lipopolysaccharide (LPS) induced hyperinflammation. Materials and Methods: Liver microcirculation in rats was obtained using intravital microscopy. Macrohemodynamic parameters, blood assays, and organs were harvested to determine organ function and injury. Hyperinflammation was induced by LPS and PD-4-I rolipram was administered intravenously one hour after LPS application. Cell viability of HepG2 cells was measured by EZ4U-kit based on the dye XTT. Experiments were carried out assessing the influence of different concentrations of tumor necrosis factor alpha (TNF-α) and LPS with or without PD-4-I. Results: Untreated LPS-induced rats showed significantly decreased liver microcirculation and increased hepatic cell death, whereas LPS + PD-4-I treatment could improve hepatic volumetric flow and cell death to control level whithout influencing the inflammatory impact. In HepG2 cells TNF-α and LPS significantly reduced cell viability. Coincubation with PD-4-I increased HepG2 viability to control levels. The heme oxygenase 1 (HO-1) pathway did not induce the protective effect of PD-4-I. Conclusion: Intravenous PD-4-I treatment was effective in improving hepatic microcirculation and hepatic integrity, while it had a direct protective effect on HepG2 viability during inflammation. [ABSTRACT FROM AUTHOR]

Background: Fibrosis is an important factor and process of ligamentum flavum hypertrophy. The expression of phosphodiesterase family (PDE) is related to inflammation and fibrosis. This article studied the expression of PDE in hypertrophic ligamentum flavum fibroblasts and investigated whether inhibition of PDE4 activity can play an anti-fibrotic effect.Methods: Samples of clinical hypertrophic ligamentum flavum were collected and patients with lumbar disc herniations as a control group. The collagenase digestion method is used to separate fibroblasts. qPCR is used to detect the expression of PDE subtypes, type I collagen (Col I), type III collagen (Col III), fibronectin (FN1) and transforming growth factor β1 (TGF-β1). Recombinant TGF-β1 was used to stimulate fibroblasts to make a fibrotic cell model and treated with Rolipram. The morphology of the cells treated with drugs was observed by Sirius Red staining. Scratch the cells to observe their migration and proliferation. WB detects the expression of the above-mentioned multiple fibrotic proteins after drug treatment. Finally, combined with a variety of signaling pathway drugs, the signaling mechanism was studied.Results: Multiple PDE subtypes were expressed in ligamentum flavum fibroblasts. The expression of PDE4A and 4B was significantly up-regulated in the hypertrophic group. Using Rolipram to inhibit PDE4 activity, the expression of Col I and TGF-β1 in the hypertrophic group was inhibited. Col I recovered to the level of the control group. TGF-β1 was significantly inhibited, which was lower than the control group. Recombinant TGF-β1 stimulated fibroblasts to increase the expression of Col I/III, FN1 and TGF-β1, which was blocked by Rolipram. Rolipram restored the increased expression of p-ERK1/2 stimulated by TGF-β1.Conclusion: The expressions of PDE4A and 4B in the hypertrophic ligamentum flavum are increased, suggesting that it is related to the hypertrophy of the ligamentum flavum. Rolipram has a good anti-fibrosis effect after inhibiting the activity of PDE4. This is related to blocking the function of TGF-β1, specifically by restoring normal ERK1/2 signal. [ABSTRACT FROM AUTHOR]

Obesity is a major health problem. We investigated the effects of forskolin and rolipram in the diet of animals in which obesity had been induced. We used 50 female albino Wistar rats that were assigned randomly into five groups as follows: group 1, control; group 2, high fat diet; group 3, high fat diet + forskolin; group 4, high fat diet + rolipram; and group 5, high fat diet + rolipram + forskolin. The rats were fed for 10 weeks and rolipram and forskolin were administered during last two weeks. The animals were sacrificed and blood samples were obtained. Serum cAMP, cGMP and free fatty acids (FFA) levels were measured using ELISA assays. We also measured weight gain during the 10 week period. cAMP and FFA levels of groups 3, 4 and 5 were significantly higher than those of groups 1 and 2. We found no significant differences in serum cGMP levels among the groups. The weight gain in groups 3, 4 and 5 was significantly less than for group 2. We also found that the weight gain in group 5 was significantly less than in groups 3 and 4. We found that both forskolin and rolipram stimulated lipolysis and inhibited body weight increase by increasing cAMP levels. Also, combination therapy using the two agents may be more effective in preventing diet induced obesity than either agent alone. We found also that these agents did not effect cellular cGMP levels in diet induced obesity. [ABSTRACT FROM AUTHOR]

Introduction Phosphodiesterase type 5 ( PDE5) inhibitors act as effective drugs for the treatment of lower urinary tract symptom ( LUTS). There is a poor information, however, about the role of the PDE4 inhibitors on the bladder outflow region contractility. Aim To investigate PDE4 expression and the relaxation induced by the PDE4 inhibitor rolipram versus that induced by the PDE5 blockers sildenafil and vardenafil, in the pig and human bladder neck. Methods Immunohistochemistry for PDE4 expression, myographs for isometric force recordings and fura-2 fluorescence for simultaneous measurements of intracellular Ca2+ concentration ([ Ca2+] i) and tension for rolipram in bladder neck samples were used. Main Outcome Measures PDE4 expression and relaxations to PDE4 and PDE5 inhibitors and simultaneous measurements of [ Ca2+] i and tension. Results PDE4 expression was observed widely distributed in the smooth muscle layer of the pig and human bladder neck. On urothelium-denuded phenylephrine ( PhE)-precontracted strips of pig and human, rolipram, sildenafil and vardenafil produced concentration-dependent relaxations with the following order of potency: rolipram> > sildenafil>vardenafil. In pig, the adenylyl cyclase activator forskolin potentiated rolipram-elicited relaxation, whereas protein kinase A ( PKA) blockade reduced such effect. On potassium-enriched physiological saline solution ( KPSS)-precontracted strips, rolipram evoked a lower relaxation than that obtained on PhE-stimulated preparations. Inhibition of large ( BKCa) and intermediate ( IKCa) conductance Ca2+-activated K+ channels, neuronal voltage-gated Ca2+ channels, nitric oxide ( NO) and hydrogen sulfide ( H2S) synthases reduced rolipram responses. Rolipram inhibited the contractions induced by PhE without reducing the PhE-evoked [ Ca2+] i increase. Conclusions PDE4 is present in the pig and human bladder neck smooth muscle, where rolipram exerts a much more potent relaxation than that elicited by PDE5 inhibitors. In pig, rolipram-induced response is produced through the PKA pathway involving BKCa and IKCa channel activation and [ Ca2+]i desensitization-dependent mechanisms, this relaxation also being due to neuronal NO and H2S release. Ribeiro ASF, Fernandes VS, Martínez-Sáenz A, Martínez P, Barahona MV, Orensanz LM, Blaha I, Serrano-Margüello D, Bustamante S, Carballido J, García-Sacristán A, Prieto D, and Hernández M. Powerful relaxation of phosphodiesterase type 4 inhibitor rolipram in the pig and human bladder neck. J Sex Med 2014;11:930-941. [ABSTRACT FROM AUTHOR]

OBJECTIVE To investigate the protective roles of type 4 phosphodiesterase (PDE4) inhibitor in cyclophosphamide (CYP)-induced haemorrhagic cystitis, as the PDE4 inhibitor has anti-inflammatory effects but its characterization is still unknown in urinary tract diseases. MATERIALS AND METHODS In female Sprague-Dawley rats, CYP was administered intraperitoneally and bladders were harvested 24 h after CYP injection. In another group, rolipram as a PDE4 inhibitor was administered before CYP treatment. The effects and mechanisms of CYP with/without rolipram pretreatment were evaluated by microscopic features, bladder wet weight, myeloperoxidase (MPO) activity, nitric oxide (NO)-metabolite production and expression levels of inflammation-related genes. RESULTS CYP injection resulted in severe cystitis. Pretreatment with rolipram significantly reduced the increase in bladder wet weight and MPO activity, and ameliorated histological inflammatory changes caused by CYP. The levels of inflammation-related transcripts including inducible NO synthase (iNOS), interleukin-1β and tumour necrosis factor-α, induced by CYP, were down-regulated significantly by pretreatment with rolipram. Also, rolipram reduced the NO-metabolite production and iNOS protein expression in the immunohistochemical examination. CONCLUSION These results indicate that rolipram can attenuate the development of CYP-induced cystitis in rats by suppressing cytokine production and iNOS induction. Thus, treatment with PDE4 inhibitor has potential clinical implications of the prevention of bladder inflammatory diseases. [ABSTRACT FROM AUTHOR]

Abstract: Rolipram, a specific inhibitor of the phosphodiesterase IV (PDE IV), has recently been shown to exert neuroprotective effects in an Alzheimer transgenic mouse model and in hypoxic–ischemic damage in the rat brain. It activates the cAMP-dependent protein kinase (PKA)/cAMP regulatory element-binding protein (CREB) signaling pathway and it inhibits inflammation. We tested the neuroprotective effects of the specific PDE IV inhibitor rolipram in C57BL/6 mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). We found that rolipram administered at 1.25 mg/kg or 2.5 mg/kg doses significantly attenuated MPTP-induced dopamine depletion in the striatum, and reduced the loss of tyrosine hydroxylase-positive neurons in the substantia nigra. There was a bell-shaped dose effect with greater efficacy at the 1.25 mg/kg dose than 2.5 mg/kg and a higher dose of rolipram, 5 mg/kg, had no protective effect and even increased the mortality of animals when co-administered with MPTP. Rolipram did not interact with MPTP in its absorption into the brain and in its metabolism to 1-methyl-4-phenylpyridinium (MPP+). Our data show a neuroprotective effect of the PDE IV specific inhibitor rolipram against dopaminergic neuron degeneration, suggesting that PDE IV inhibitors might be a potential treatment for Parkinson''s disease. [Copyright &y& Elsevier]

Abstract: Cyclic nucleotide phosphodiesterase-4 (PDE4) is a component of signaling pathways involved in the mediation of antidepressant activity. Of the four PDE4 subtypes, PDE4D appears to be of particular importance, given the finding that PDE4D-deficient mice exhibit an antidepressant-like behavioral phenotype. In mouse hippocampus and cerebral cortex, the effects of repeated treatment with the antidepressants desipramine and fluoxetine or the PDE4 inhibitor rolipram on the expression of PDE4D was compared to that of PDE4A and PDE4B, the other two subtypes expressed in the brain. Expression of PDE4D was increased by all drugs tested, with the exception of desipramine in hippocampus. By contrast, these treatments affected PDE4A and PDE4B expression differentially. In hippocampus, antidepressants increased PDE4A and decreased PDE4B, whereas ROL decreased PDE4A and did not change PDE4B. In cerebral cortex, antidepressants increased PDE4A and did not change PDE4B, whereas ROL did not change PDE4A and increased PDE4B. 3H-Rolipram binding was increased in cytosolic, but not in membrane, fractions of cerebral cortex by all drugs tested; there were no changes observed in hippocampus. Overall, the present results suggest some species-dependence of the regulation of PDE4 subtypes, based on data obtained previously using rats. They also suggest that the PDE4D subtype may be of particular importance as an antidepressant target in that it is regulated by repeated treatment with both norepinephrine and serotonin reuptake inhibitors as well as by the PDE4 inhibitor rolipram, drugs that produce antidepressant effects via different neuropharmacological mechanisms. [Copyright &y& Elsevier]

A novel, efficient and protecting group free enantioselective synthetic approach of (−)-( R )- 1 and (+)-( S )-rolipram 2 is described employing the organocatalyzed asymmetric Michael addition, Henry condensation, Wittig olefination and reductive lactamization reactions as key steps. [ABSTRACT FROM AUTHOR]

Caffeine administration is an important part of the therapeutic treatment of bronchopulmonary dysplasia (BPD) in preterm infants. However, caffeine mediated effects on airway remodelling are still undefined. The TGF-β/Smad signalling pathway is one of the key pathways involved in airway remodelling. Connective tissue growth factor (CTGF), a downstream mediator of TGF-β, and transgelin, a binding and stabilising protein of the cytoskeleton, are both regulated by TGF-β1 and play an important role in airway remodelling. Both have also been implicated in the pathogenesis of BPD. The aim of the present study was to clarify whether caffeine, an unspecific phosphodiesterase (PDE) inhibitor, and rolipram, a prototypical PDE-4 selective inhibitor, were both able to affect TGF-β1-induced Smad signalling and CTGF/transgelin expression in lung epithelial cells. Furthermore, the effect of transgelin knock-down on Smad signalling was studied. The pharmacological effect of caffeine and rolipram on Smad signalling was investigated by means of a luciferase assay via transfection of a TGF-β1-inducible reporter plasmid in A549 cells. The regulation of CTGF and transgelin expression by caffeine and rolipram were studied by promoter analysis, real-time PCR and Western blot. Endogenous transgelin expression was down-regulated by lentiviral transduction mediating transgelin-specific shRNA expression. The addition of caffeine and rolipram inhibited TGF-β1 induced reporter gene activity in a concentration-related manner. They also antagonized the TGF-β1 induced up-regulation of CTGF and transgelin on the promoter-, the mRNA-, and the protein-level. Functional analysis showed that transgelin silencing reduced TGF-β1 induced Smad-signalling and CTGF induction in lung epithelial cells. The present study highlights possible new molecular mechanisms of caffeine and rolipram including an inhibition of Smad signalling and of TGF-β1 regulated genes involved in airway remodelling. An understanding of these mechanisms might help to explain the protective effects of caffeine in prevention of BPD and suggests rolipram to be a potent replacement for caffeine. [ABSTRACT FROM AUTHOR]