Phosphodiesterase 4 inhibitors in chronic obstructive pulmonary disease: a new approach to oral treatment

PubMed Central

Currie, Graeme P; Butler, Claire A; Anderson, Wendy J; Skinner, Chris

2008-01-01

Chronic obstructive pulmonary disease represents a major global health care burden for both primary and secondary care providers and is the most common respiratory condition necessitating hospital admission. Short-acting bronchodilators play a vital role in immediate relief of symptoms, while inhaled long-acting bronchodilators and inhaled corticosteroids are advocated for regular use in individuals with persistent symptoms and exacerbations. Theophylline is a nonspecific phosphodiesterase inhibitor and is usually reserved for patients with ongoing symptoms despite optimum inhaled bronchodilator treatment or when difficulty is encountered with inhaler devices. However, it is often not widely used mainly due to frequency of dose-related adverse effects, numerous drug interactions and narrow therapeutic index. This in turn has lead to the development of more selective phosphodiesterase inhibitors in an attempt to create a drug which patients can use with beneficial effects but without the problems associated with theophylline. Current data do indicate that phosphodiesterase 4 inhibitors confer some benefits in chronic obstructive pulmonary disease when compared to placebo in terms of lung function, quality of life and exacerbations. They are also generally well tolerated. Further studies are required to determine fully their long-term beneficial and adverse effect profiles and ultimately where they might comfortably sit in management algorithms. PMID:18341675

Phosphodiesterase 4 regulates the migration of B16-F10 melanoma cells.

PubMed

Watanabe, Yoshihiro; Murata, Taku; Shimizu, Kasumi; Morita, Hiroshi; Inui, Madoka; Tagawa, Toshiro

2012-08-01

Phosphodiesterases (PDEs) are important regulators of signal transduction processes. Eleven PDE gene families (PDE1-11) have been identified and several PDE isoforms are selectively expressed in various cell types. PDE4 family members specifically hydrolyze cyclic AMP (cAMP). Four genes (PDE4A-D) are known to encode PDE4 enzymes, with additional diversity generated by the use of alternative mRNA splicing and the use of different promoters. While PDE4 selective inhibitors show therapeutic potential for treating major diseases such as asthma and chronic obstructive pulmonary disease, little is known concerning the role of PDE4 in malignant melanoma. In this study, we examined the role of PDE4 in mouse B16-F10 melanoma cells. In these cells, PDE4 activity was found to be ∼60% of total PDE activity. RT-PCR detected only PDE4B and PDE4D mRNA. Cell growth was inhibited by the cAMP analog, 8-bromo-cAMP, but not by the specific PDE4 inhibitors, rolipram and denbufylline, which increased intracellular cAMP concentrations. Finally, migration of the B16-F10 cells was inhibited by the PDE4 inhibitors and 8-bromo-cAMP, while migration was increased by a protein kinase A (PKA) inhibitor, PKI(14-22), and was not affected by 8-pCPT-2'-O-Me-cAMP, which is an analog of exchange protein activated by cAMP (Epac). The inhibitory effect of rolipram on migration was reversed by PKI(14-22). Based on these results, PDE4 appears to play an important role in the migration of B16-F10 cells, and therefore may be a novel target for the treatment of malignant melanoma.

Effects of selective phosphodiesterases-4 inhibitors on learning and memory: a review of recent research.

PubMed

Peng, Sheng; Sun, Haiyan; Zhang, Xiaoqing; Liu, Gongjian; Wang, Guanglei

2014-09-01

Phosphodiesterase-4 (PDE-4) regulates the intracellular level of cyclic adenosine monophosphate. Recent studies demonstrated that PDE-4 inhibitors can counteract deficits in long-term memory caused by aging or increased expression of mutant forms of human amyloid precursor proteins, and can influence the process of memory function and cognitive enhancement. Therapeutics, such as ketamine, a drug used in clinical anesthesia, can also cause memory deficits as adverse effects. Targeting PDE-4 with selective inhibitors may offer a novel therapeutic strategy to prevent, slow the progress, and, eventually, treat memory deficits.

Tyrosyl-DNA phosphodiesterase inhibitors: Progress and potential.

PubMed

Laev, Sergey S; Salakhutdinov, Nariman F; Lavrik, Olga I

2016-11-01

DNA topoisomerases are essential during transcription and replication. The therapeutic mechanism of action of topoisomerase inhibitors is enzyme poisoning rather than catalytic inhibition. Tyrosyl-DNA phosphodiesterases 1 or 2 were found as DNA repair enzymes hydrolyzing the covalent bond between the tyrosyl residue of topoisomerases I or II and the 3'- or 5'-phosphate groups in DNA, respectively. Tyrosyl-DNA phosphodiesterase 1 is a key enzyme in DNA repair machinery and a promising target for antitumor and neurodegenerative therapy. Inhibitors of tyrosyl-DNA phosphodiesterase 1 could act synergistically with topoisomerase I inhibitors and thereby potentiate the effects of topoisomerase I poisons. Tyrosyl-DNA phosphodiesterase 2 is an enzyme that specifically repairs DNA damages induced by topoisomerase II poisons and causes resistance to these drugs. Selective inhibition of tyrosyl-DNA phosphodiesterase 2 may be a novel approach to overcome intrinsic or acquired resistance to topoisomerase II-targeted drug therapy. Thus, agents that inhibit tyrosyl-DNA phosphodiesterases 1 and 2 have many applications in biochemical and physiological research and they have the potential to become anticancer and antiviral drugs. The structures, mechanism of action and therapeutic rationale of tyrosyl-DNA phosphodiesterase inhibitors and their development for combinations with topoisomerase inhibitors and DNA damaging agents are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

6-Nitrobenzimidazole derivatives: potential phosphodiesterase inhibitors: synthesis and structure-activity relationship.

PubMed

Khan, K M; Shah, Zarbad; Ahmad, V U; Ambreen, N; Khan, M; Taha, M; Rahim, F; Noreen, S; Perveen, S; Choudhary, M I; Voelter, W

2012-02-15

6-Nitrobenzimidazole derivatives (1-30) synthesized and their phosphodiesterase inhibitory activities determined. Out of thirty tested compounds, ten showed a varying degrees of phosphodiesterase inhibition with IC(50) values between 1.5±0.043 and 294.0±16.7 μM. Compounds 30 (IC(50)=1.5±0.043 μM), 1 (IC(50)=2.4±0.049 μM), 11 (IC(50)=5.7±0.113 μM), 13 (IC(50)=6.4±0.148 μM), 14 (IC(50)=10.5±0.51 μM), 9 (IC(50)=11.49±0.08 μM), 3 (IC(50)=63.1±1.48 μM), 10 (IC(50)=120.0±4.47 μM), and 6 (IC(50)=153.2±5.6 μM) showed excellent phosphodiesterase inhibitory activity, much superior to the standard EDTA (IC(50)=274±0.007 μM), and thus are potential molecules for the development of a new class of phosphodiesterase inhibitors. A structure-activity relationship is evaluated. All compounds are characterized by spectroscopic parameters. Copyright © 2011 Elsevier Ltd. All rights reserved.

The mediating role of phosphodiesterase type 4 in the dopaminergic modulation of motor impulsivity.

PubMed

Heckman, P R A; Blokland, A; Van Goethem, N P; Van Hagen, B T J; Prickaerts, J

2018-09-17

The current study investigated the mediating role of phosphodiesterase type 4 (PDE4) regulated cAMP in the dopaminergic modulation of premature responding (action restraint) in rats. Response inhibition, which includes action restraint, finds its neurobiological origin in cortico-striatal-thalamic circuitry and can be modulated by dopamine. Intracellularly, the effect of dopamine is largely mediated through the cAMP/PKA signaling cascade. Areas in the prefrontal cortex are very sensitive to their neurochemical environment, including catecholamine levels. As a result, we investigated the effects of intracellular modulation of the dopamine cascade by means of PDE4 inhibition by roflumilast on premature responding in a hypo, normal and hyper dopaminergic state of the brain. As a hypo dopaminergic model we induced a 6-OHDA lesion in the (rat) prefrontal cortex, more specifically the infralimbic cortex. For the hyper dopaminergic state we also turned to a well-established model of impaired action restraint, namely the systemic administration of d-amphetamine. In line with the notion of a U-shaped relation between dopamine and impulsive responding, we found that both increasing and decreasing dopamine levels resulted in an increase in premature responding in the choice serial reaction time task (CSRTT). The PDE4 inhibitor roflumilast increased premature responses in combination with d-amphetamine, whereas a decrease in premature responding after roflumilast treatment was found in the 6-OHDA lesioned animals. As a result, it would be interesting to test the effects of PDE4 inhibition in disorders affected by disrupted impulse control related to cortico-striatal-thalamic hypodopaminergia including attention deficit hyperactivity disorder (ADHD). Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Characterization of particulate cyclic nucleotide phosphodiesterases from bovine brain: Purification of a distinct cGMP-stimulated isoenzyme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murashima, Seiko; Tanaka, Takayuki; Hockman, S.

1990-06-05

In the absence of detergent, {approx}80-85% of the total cGMP-stimulated phosphodiesterase (PDE) activity in bovine brain was associated with washed particulate fractions; {approx}85-90% of the calmodulin-sensitive PDE was soluble. Particulate cGMP-stimulated PDE was higher in cerebral cortical gray matter than in other regions. Homogenization of the brain particulate fraction in 1% Lubrol increased cGMP-stimulated activity {approx}100% and calmodulin-stimulated {approx}400-500%. Although 1% Lubrol readily solubilized these PDE activities, {approx}75% of the cAMP PDE activity (0.5 {mu}M ({sup 3}H)cAMP) that was not affected by cGMP was not solubilized. This cAMP PDE activity was very sensitive to inhibition by Rolipram but not cilostamide.more » Thus, three different PDE types, i.e., cGMP stimulated, calmodulin sensitive, and Rolipram inhibited, are associated in different ways with crude bovine brain particulate fractions. The brain enzyme exhibited a slightly greater subunit M{sub r} than did soluble forms from calf liver or bovine brain, as evidenced by protein staining or immunoblotting after polyacrylamide gel electrophoresis under denaturing conditions. Incubation of brain particulate and liver soluble cGMP-stimulated PDEs with V{sub 8} protease produced several peptides of similar size, as well as at least two distinct fragments of {approx}27 kDa from the brain and {approx}23 kDa from the liver enzyme. After photolabeling in the presence of ({sup 32}P)cGMP and digestion with V{sub 8} protease, ({sup 32}P)cGMP in each PDE was predominantly recovered with a peptide of {approx}14 kDa. All of these observations are consistent with the existence of at least two discrete forms (isoenzymes) of cGMP-stimulated PDE.« less

IFN-γ promotes transendothelial migration of CD4+ T cells across the blood-brain barrier.

PubMed

Sonar, Sandip Ashok; Shaikh, Shagufta; Joshi, Nupura; Atre, Ashwini N; Lal, Girdhari

2017-10-01

Transendothelial migration (TEM) of Th1 and Th17 cells across the blood-brain barrier (BBB) has a critical role in the development of experimental autoimmune encephalomyelitis (EAE). How cytokines produced by inflammatory Th1 and Th17 cells damage the endothelial BBB and promote transendothelial migration of immune cells into the central nervous system (CNS) during autoimmunity is not understood. We therefore investigated the effect of various cytokines on brain endothelial cells. Among the various cytokines tested, such as Th1 (IFN-γ, IL-1α, IL-1β, TNF-α, IL-12), Th2 (IL-3, IL-4, IL-6 and IL-13), Th17 (IL-17A, IL-17F, IL-21, IL-22, IL-23, GM-CSF) and Treg-specific cytokines (IL-10 and TGF-β), IFN-γ predominantly showed increased expression of ICAM-1, VCAM-1, MAdCAM-1, H2-K b and I-A b molecules on brain endothelial cells. Furthermore, IFN-γ induced transendothelial migration of CD4 + T cells from the apical (luminal side) to the basal side (abluminal side) of the endothelial monolayer to chemokine CCL21 in a STAT-1-dependent manner. IFN-γ also favored the transcellular route of TEM of CD4 + T cells. Multicolor immunofluorescence and confocal microscopic analysis showed that IFN-γ induced relocalization of ICAM-1, PECAM-1, ZO-1 and VE-cadherin in the endothelial cells, which affected the migration of CD4 + T cells. These findings reveal that the IFN-γ produced during inflammation could contribute towards disrupting the BBB and promoting TEM of CD4 + T cells. Our findings also indicate that strategies that interfere with the activation of CNS endothelial cells may help in controlling neuroinflammation and autoimmunity.

Boron-based phosphodiesterase inhibitors show novel binding of boron to PDE4 bimetal center.

PubMed

Freund, Yvonne R; Akama, Tsutomu; Alley, M R K; Antunes, Joana; Dong, Chen; Jarnagin, Kurt; Kimura, Richard; Nieman, James A; Maples, Kirk R; Plattner, Jacob J; Rock, Fernando; Sharma, Rashmi; Singh, Rajeshwar; Sanders, Virginia; Zhou, Yasheen

2012-09-21

We have used boron-based molecules to create novel, competitive, reversible inhibitors of phosphodiesterase 4 (PDE4). The co-crystal structure reveals a binding configuration which is unique compared to classical catechol PDE4 inhibitors, with boron binding to the activated water in the bimetal center. These phenoxybenzoxaboroles can be optimized to generate submicromolar potency enzyme inhibitors, which inhibit TNF-α, IL-2, IFN-γ, IL-5 and IL-10 activities in vitro and show safety and efficacy for topical treatment of human psoriasis. They provide a valuable new route for creating novel potent anti-PDE4 inhibitors. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Newer treatments of psoriasis regarding IL-23 inhibitors, phosphodiesterase 4 inhibitors, and Janus kinase inhibitors.

PubMed

Wcisło-Dziadecka, Dominika; Zbiciak-Nylec, Martyna; Brzezińska-Wcisło, Ligia; Bebenek, Katarzyna; Kaźmierczak, Agata

2017-11-01

The rapid progress of genetic engineering furthermore opens up new prospects in the therapy of this difficult-to-treat disease. IL-23 inhibitors, phosphodiesterase 4 (PDE4) inhibitors, and Janus kinase (JAK) inhibitors are currently encouraging further research. Two drugs which are IL-23 inhibitors are now in phase III of clinical trials. The aim of the action of both drugs is selective IL-23 inhibition by targeting the p19 subunit. Guselkumab is a fully human monoclonal antibody. Tildrakizumab is a humanized monoclonal antibody, which also belongs to IgG class and is targeted to subunit p19 of interleukin 23 (IL-23). Phosphodiesterase inhibitors exert an anti-inflammatory action and their most common group is the PDE4 family. PDE4 inhibits cAMP, which reduces the inflammatory response of the pathway of Th helper lymphocytes, Th17, and type 1 interferon which modulates the production of anti-inflammatory cytokines such as IL-10 interleukins. The Janus kinase (JAK) signaling pathway plays an important role in the immunopathogenesis of psoriasis. Tofacitinib suppresses the expression of IL-23, IL-17A, IL-17F, and IL-22 receptors during the stimulation of lymphocytes. Ruxolitinib is a selective inhibitor of JAK1 and JAK2 kinases and the JAK-STAT signaling pathway. This article is a review of the aforementioned drugs as described in the latest available literature. © 2017 Wiley Periodicals, Inc.

Phosphodiesterase 4 Inhibitors Attenuate the Asthma Phenotype Produced by β2-Adrenoceptor Agonists in Phenylethanolamine N-Methyltransferase-Knockout Mice.

PubMed

Forkuo, Gloria S; Kim, Hosu; Thanawala, Vaidehi J; Al-Sawalha, Nour; Valdez, Daniel; Joshi, Radhika; Parra, Sergio; Pera, Tonio; Gonnella, Patricia A; Knoll, Brian J; Walker, Julia K L; Penn, Raymond B; Bond, Richard A

2016-08-01

Mice lacking the endogenous β2-adrenoceptor (β2AR) agonist epinephrine (phenylethanolamine N-methyltransferase [PNMT]-knockout mice) are resistant to developing an "asthma-like" phenotype in an ovalbumin sensitization and challenge (Ova S/C) model, and chronic administration of β2AR agonists to PNMT-KO mice restores the phenotype. Based on these and other studies showing differential effects of various β2AR ligands on the asthma phenotype, we have speculated that the permissive effect of endogenous epinephrine and exogenous β2AR agonists on allergic lung inflammation can be explained by qualitative β2AR signaling. The β2AR can signal through at least two pathways: the canonical Gαs-cAMP pathway and a β-arrestin-dependent pathway. Previous studies suggest that β-arrestin-2 is required for allergic lung inflammation. On the other hand, cell-based assays suggest antiinflammatory effects of Gαs-cAMP signaling. This study was designed to test whether the in vitro antiinflammatory effects of phosphodiesterase 4 inhibitors, known to increase intracellular cAMP in multiple airway cell types, attenuate the asthma-like phenotype produced by the β2AR agonists formoterol and salmeterol in vivo in PNMT-KO mice, based on the hypothesis that skewing β2AR signaling toward Gαs-cAMP pathway is beneficial. Airway inflammatory cells, epithelial mucus production, and airway hyperresponsiveness were quantified. In Ova S/C PNMT-KO mice, formoterol and salmeterol restored the asthma-like phenotype comparable to Ova S/C wild-type mice. However, coadministration of either roflumilast or rolipram attenuated this formoterol- or salmeterol-driven phenotype in Ova S/C PNMT-KO. These findings suggest that amplification of β2AR-mediated cAMP by phosphodiesterase 4 inhibitors attenuates the asthma-like phenotype promoted by β-agonists.

A selective phosphodiesterase 10A inhibitor reduces l-dopa-induced dyskinesias in parkinsonian monkeys.

PubMed

Beck, Goichi; Maehara, Shunsuke; Chang, Phat Ly; Papa, Stella M

2018-03-06

Phosphodiesterase 10A is a member of the phosphodiesterase family whose brain expression is restricted to the striatum. Phosphodiesterase 10A regulates cyclic adenosine monophosphate and cyclic guanosine monophosphate, which mediate responses to dopamine receptor activation, and the levels of these cyclic nucleotides are decreased in experimental models of l-dopa-induced dyskinesia. The elevation of cyclic adenosine monophosphate/cyclic guanosine monophosphate levels by phosphodiesterase 10A inhibition may thus be targeted to reduce l-dopa-induced dyskinesia. The present study was aimed at determining the potential antidyskinetic effects of phosphodiesterase 10A inhibitors in a primate model of Parkinson's disease (PD). The experiments performed in this model were also intended to provide translational data for the design of future clinical trials. Five MPTP-treated macaques with advanced parkinsonism and reproducible l-dopa-induced dyskinesia were used. MR1916, a selective phosphodiesterase 10A inhibitor, at doses 0.0015 to 0.05 mg/kg, subcutaneously, or its vehicle (control test) was coadministered with l-dopa methyl ester acutely (predetermined optimal and suboptimal subcutaneous doses) and oral l-dopa chronically as daily treatment for 5 weeks. Standardized scales were used to assess motor disability and l-dopa-induced dyskinesia by blinded examiners. Pharmacokinetics was also examined. MR1916 consistently reduced l-dopa-induced dyskinesia in acute tests of l-dopa optimal and suboptimal doses. Significant effects were present with every MR1916 dose tested, but the most effective was 0.015 mg/kg. None of the MR1916 doses tested affected the antiparkinsonian action of l-dopa at the optimal dose. The anti-l-dopa-induced dyskinesia effect of MR1916 (0.015 mg/kg, subcutaneously) was sustained with chronic administration, indicating that tolerance did not develop over the 5-week treatment. No adverse effects were observed after MR1916 administration acutely or

The Association between Phosphodiesterase Type 5 Inhibitors and Prostate Cancer: Results from the REDUCE Study.

PubMed

Jamnagerwalla, Juzar; Howard, Lauren E; Vidal, Adriana C; Moreira, Daniel M; Castro-Santamaria, Ramiro; Andriole, Gerald L; Freedland, Stephen J

2016-09-01

Despite routine use of phosphodiesterase type 5 inhibitor to treat erectile dysfunction the role in prostate cancer chemoprevention remains unclear. Only a few studies have explored the link between phosphodiesterase type 5 inhibitor use and prostate cancer. We tested the association between phosphodiesterase type 5 inhibitor and prostate cancer risk in the REDUCE (Reduction by Dutasteride of Prostate Cancer Events) trial. REDUCE was a 4-year multicenter study testing the effect of daily dutasteride on prostate cancer risk in men with prostate specific antigen 2.5 to 10.0 ng/ml and negative biopsy who underwent study mandated biopsies at 2 and 4 years. The association of phosphodiesterase type 5 inhibitor with overall prostate cancer risk and disease grade (Gleason 2-6 and 7-10) was examined using adjusted logistic and multinomial regression analysis. Secondary analysis was performed to explore the association between phosphodiesterase type 5 inhibitor and prostate cancer risk in North American men, given the significantly higher use of phosphodiesterase type 5 inhibitor in these subjects. Phosphodiesterase type 5 inhibitor was not associated with prostate cancer diagnosis (OR 0.90, 95% CI 0.68-1.20, p = 0.476), low grade disease (OR 0.93, 95% CI 0.67-1.27, p = 0.632) or high grade disease (OR 0.85, 95% CI 0.51-1.39, p = 0.508). An inverse trend was seen between phosphodiesterase type 5 inhibitor and prostate cancer diagnosis in North American men but this was not statistically significant (OR 0.67, 95% CI 0.42-1.07, p = 0.091). Phosphodiesterase type 5 inhibitor use was not associated with decreased prostate cancer diagnoses on post-hoc analysis of REDUCE. In North American men, who had much higher baseline use of phosphodiesterase type 5 inhibitor, this treatment was associated with an inverse trend of prostate cancer diagnosis that approached but did not reach statistical significance. Copyright © 2016 American Urological Association Education and

2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-Glucoside Attenuates Ischemia/Reperfusion-Induced Brain Injury in Rats by Promoting Angiogenesis.

PubMed

Mu, Ying; Xu, Zhaohui; Zhou, Xuanxuan; Zhang, Huinan; Yang, Qian; Zhang, Yunlong; Xie, Yanhua; Kang, Juan; Li, Feng; Wang, Siwang

2017-05-01

Cerebral ischemia can cause brain infarcts, which are difficult to recover due to poor angiogenesis. 2,3,5,4'-Tetrahydroxystilbene-2-O- β -D-glucoside is a natural polyphenol, has antioxidant and anti-inflammatory activity, and can protect from ischemic neuronal injury. However, little is known about the effect of 2,3,5,4'-tetrahydroxystilbene-2-O- β -D-glucoside on brain microcirculation after stroke. This study aimed at investigating the influence of 2,3,5,4'-tetrahydroxystilbene-2-O- β -D-glucoside on brain lesions and angiogenesis after stroke. Sprague-Dawley rats were subjected to right middle cerebral artery occlusion and treated with vehicle, nimodipine, or different doses of 2,3,5,4'-tetrahydroxystilbene-2-O- β -D-glucoside daily beginning at 6 h post-middle cerebral artery occlusion for 14 days. The volume of cerebral infarcts, degree of neurological dysfunction, and level of microvessel density were determined longitudinally. The levels of vascular endothelial growth factor, angiopoietin 1, and angiopoietin receptor-2 expression in the brain lesions were characterized by immunohistochemistry and Western blot assays at 14 days post-middle cerebral artery occlusion. We found that 2,3,5,4'-tetrahydroxystilbene-2-O- β -D-glucoside significantly promoted postoperative recovery in rats by minimizing the volume of cerebral infarcts and improving neurological dysfunction in a dose- and time-dependent manner. Additionally, 2,3,5,4'-tetrahydroxystilbene-2-O- β -D-glucoside significantly increased the microvessel density in the brain and upregulated CD31 expression in ischemic penumbra, relative to that in the control. Finally, treatment with 2,3,5,4'-tetrahydroxystilbene-2-O- β -D-glucoside significantly upregulated the relative levels of vascular endothelial growth factor, angiopoietin 1, and angiopoietin receptor-2 expression in the brain lesions of rats. Therefore, these data indicated that 2,3,5,4'-tetrahydroxystilbene-2-O- β -D-glucoside treatment

Methylxanthine reversal of opioid-evoked inspiratory depression via phosphodiesterase-4 blockade.

PubMed

Ruangkittisakul, Araya; Ballanyi, Klaus

2010-07-31

Hypothetic mechanisms for respirogenic methylxanthine actions include blockade of adenosine receptors or phosphodiesterase-4 (PDE4) in inspiratory pre-Bötzinger complex (preBötC) networks. Here, we studied this by analyzing stimulating caffeine and theophylline actions on mu-opioid-depressed inspiratory-related rhythm in the ventrolateral aspect of rat brainstem slices. The methylxanthines restored DAMGO (0.5-1 microM) depressed rhythm only at >1mM, which is approximately 10-fold higher than selective for adenosine receptors. Adenosine receptor blockers did neither counter DAMGO inhibition nor change control rhythm, similar to adenosine (0.1-2.5 mM). The specific PDE4 blocker rolipram (5 microM) restored DAMGO-depressed rhythm incompletely, but effectively reversed similar inhibition by clinical mu-agonist (fentanyl, 0.1 microM). At 0.25 microM, rolipram boosted incomplete recovery by 1 mM theophylline of DAMGO-depressed rhythm. Findings indicate that methylxanthines excite rhythmogenic preBötC networks via blockade of cAMP dependent PDE4 and suggest that specific PDE4 inhibitors (plus low methylxanthine doses) stimulate breathing effectively. We discuss why methylxanthine doses for preBötC stimulation need to be higher than those for respirogenic effects in vivo. Copyright 2010 Elsevier B.V. All rights reserved.

Administration of the Phosphodiesterase Type 4 Inhibitor Rolipram into the Amygdala at a Specific Time Interval after Learning Increases Recognition Memory Persistence

ERIC Educational Resources Information Center

Werenicz, Aline; Christoff, Raissa R.; Blank, Martina; Jobim, Paulo F. C.; Pedroso, Thiago R.; Reolon, Gustavo K.; Schroder, Nadja; Roesler, Rafael

2012-01-01

Here we show that administration of the phosphodiesterase type 4 (PDE4) inhibitor rolipram into the basolateral complex of the amygdala (BLA) at a specific time interval after training enhances memory consolidation and induces memory persistence for novel object recognition (NOR) in rats. Intra-BLA infusion of rolipram immediately, 1.5 h, or 6 h…

The effect of resveratrol on beta amyloid-induced memory impairment involves inhibition of phosphodiesterase-4 related signaling

PubMed Central

Wang, Gang; Chen, Ling; Pan, Xiaoyu; Chen, Jiechun; Wang, Liqun; Wang, Weijie; Cheng, Ruochuan; Wu, Fan; Feng, Xiaoqing; Yu, Yingcong; Zhang, Han-Ting; O'Donnell, James M.; Xu, Ying

2016-01-01

Resveratrol, a natural polyphenol found in red wine, has wide spectrum of pharmacological properties including antioxidative and antiaging activities. Beta amyloid peptides (Aβ) are known to involve cognitive impairment, neuroinflammatory and apoptotic processes in Alzheimer's disease (AD). Activation of cAMP and/or cGMP activities can improve memory performance and decrease the neuroinflammation and apoptosis. However, it remains unknown whether the memory enhancing effect of resveratrol on AD associated cognitive disorders is related to the inhibition of phosphodiesterase 4 (PDE4) subtypes and subsequent increases in intracellular cAMP and/or cGMP activities. This study investigated the effect of resveratrol on Aβ1-42-induced cognitive impairment and the participation of PDE4 subtypes related cAMP or cGMP signaling. Mice microinfused with Aβ1-42 into bilateral CA1 subregions displayed learning and memory impairment, as evidenced by reduced memory acquisition and retrieval in the water maze and retention in the passive avoidance tasks; it was also significant that neuroinflammatory and pro-apoptotic factors were increased in Aβ1-42-treated mice. Aβ1-42-treated mice also increased in PDE4A, 4B and 4D expression, and decreased in PKA level. However, PKA inhibitor H89, but not PKG inhibitor KT5823, prevented resveratrol's effects on these parameters. Resveratrol also reversed Aβ1-42-induced decreases in phosphorylated cAMP response-element binding protein (pCREB), brain derived neurotrophic factor (BDNF) and anti-apoptotic factor BCl-2 expression, which were reversed by H89. These findings suggest that resveratrol reversing Aβ-induced learning and memory disorder may involve the regulation of neuronal inflammation and apoptosis via PDE4 subtypes related cAMP-CREB-BDNF signaling. PMID:26980711

Dual inhibition of human type 4 phosphodiesterase isostates by (R, R)-(+/-)-methyl 3-acetyl-4-[3-(cyclopentyloxy)-4-methoxyphenyl]-3- methyl-1-pyrrolidinecarboxylate.

PubMed

Tian, G; Rocque, W J; Wiseman, J S; Thompson, I Z; Holmes, W D; Domanico, P L; Stafford, J A; Feldman, P L; Luther, M A

1998-05-12

Purified recombinant human type 4 phosphodiesterase B2B (HSPDE4B2B) exists in both a low- and a high-affinity state that bind (R)-rolipram with Kd's of ca. 500 and 1 nM, respectively [Rocque, W. J., Tian, G., Wiseman, J. S., Holmes, W. D., Thompson, I. Z., Willard, D. H., Patel, I. R., Wisely, G. B., Clay, W. C., Kadwell, S. H., Hoffman, C. R., and Luther, M. A. (1997) Biochemistry 36, 14250-14261]. Since the tissue distribution of the two isostates may be significantly different, development of inhibitors that effectively inhibit both forms may be advantageous pharmacologically. In this study, enzyme inhibition and binding of HSPDE4B2B by (R, R)-(+/-)-methyl 3-acetyl-4-[3-(cyclopentyloxy)-4-methoxyphenyl]-3-methyl-1-pyrrolidin ecarboxylate (1), a novel inhibitor of phosphodiesterase 4 (PDE 4), were investigated. Binding experiments demonstrated high-affinity binding of 1 to HSPDE4B2B with a stoichiometry of 1:1. Inhibition of PDE activity showed only a single transition with an observed Ki similar to the apparent Kd determined by the binding experiments. Deletional mutants of HSPDE4B2B, which have been shown to bind (R)-rolipram with low affinity, were shown to interact with 1 with high affinity, indistinguishable from the results obtained with the full-length enzyme. Bound 1 was completely displaced by (R)-rolipram, and the displacement showed a biphasic transition that resembles the biphasic inhibition of HSPDE4B2B by (R)-rolipram. Theoretical analysis of the two transitions exemplified in the interaction of (R)-rolipram with HSPDE4B2B indicated that the two isostates were nonexchangeable. Phosphorylation at serines 487 and 489 on HSPDE4B2B had no effect on the stoichiometry of binding, the affinity for binding, or the inhibition of the enzyme by 1. These data further illustrate the presence of two isostates in PDE 4 as shown previously for (R)-rolipram binding and inhibition. In contrast to (R)-rolipram, where only one of the two isostates of PDE 4 binds with

Towards selective phosphodiesterase 2A (PDE2A) inhibitors: a patent review (2010 - present).

PubMed

Trabanco, Andrés A; Buijnsters, Peter; Rombouts, Frederik J R

2016-08-01

The cyclic nucleotides cAMP and cGMP are ubiquitous intracellular second messengers regulating a large variety of biological processes. The intracellular concentration of these biologically relevant molecules is modulated by the activity of phosphodiesterases (PDEs), a class of enzymes that is grouped in 11 families. The expression of PDEs is tissue- and cell-specific allowing spatiotemporal integration of multiple signaling cascades. PDE2A is a dual substrate enzyme and is expressed in both the periphery and in the central nervous system, however its expression is highest in the brain, where it is mainly localized in the cortex, hippocampus, and striatum. This suggests that this enzyme may regulate intraneuronal cGMP and cAMP levels in brain areas involved in emotion, perception, concentration, learning and memory. This review covers the patent applications published between January 2010 and February 2016 on phosphodiesterase 2A inhibitors. Recent publications in the literature and in filed patent applications demonstrate the interest of pharmaceutical companies for PDE2A. This has increased the insights of its possible therapeutic role but the few clinical trials were terminated. Based on the ongoing interest in the field it is likely that new clinical trials can be expected and will unravel the therapeutic potential of PDE2A inhibition.

Antidiuretic hormone resistance in the neonatal cortical collecting tubule is mediated in part by elevated phosphodiesterase activity

PubMed Central

Quigley, Raymond; Chakravarty, Sumana; Baum, Michel

2014-01-01

Neonates cannot concentrate their urine to the same degree as adults. One of the key factors in concentrating the urine is the renal collecting duct osmotic water permeability (Pf) response to antidiuretic hormone (ADH). Neonatal cortical collecting ducts have a blunted Pf response to ADH compared with adult tubules (Pf: 119.0 ± 12.5 vs. 260.1 ± 29.5 µm/s, P < 0.05). We found that the phosphodiesterase activity in the neonatal collecting ducts was higher than that in the adult collecting ducts (3,970 ± 510 vs. 2,440 ± 220 cpm·µg tubular protein−1·20 min−1, P < 0.05). After pretreatment of in vitro microperfused tubules with the nonspecific phosphodiesterase inhibitor IBMX (10−6 M in the bath), the Pf response to ADH in neonatal collecting ducts was 271.4 ± 51.7 µm/s, which was identical to that of the adult collecting duct [315.3 ± 31.3 µm/s, P = not significant (NS)]. Rolipram, a specific type IV phosphodiesterase inhibitor, lowered the elevated phosphodiesterase activity in the neonatal tubules to that in the adult tubules (2,460 ± 210 vs. 2,160 ± 230 cpm·µg tubular protein−1·20 min−1, P = NS). Neonatal tubules pretreated with rolipram (10−5 M) in the bath also had a Pf response to ADH that was comparable to that of the adult tubules (258.2 ± 17.0 vs. 271.4 ± 32.6 µm/s, P = NS). Thus the elevated phosphodiesterase activity in the neonatal tubules appears to be due to an increase in type IV phosphodiesterase activity. Hence, one of the key factors in the decreased ability of neonates to concentrate their urine is overactivity of phosphodiesterase in the cortical collecting duct that blunts the neonatal collecting duct Pf response to ADH. PMID:14644747

Phosphodiesterase 7 Inhibition Induces Dopaminergic Neurogenesis in Hemiparkinsonian Rats

PubMed Central

Morales-Garcia, Jose A.; Alonso-Gil, Sandra; Gil, Carmen; Martinez, Ana; Santos, Angel

2015-01-01

Parkinson’s disease is characterized by a loss of dopaminergic neurons in a specific brain region, the ventral midbrain. Parkinson’s disease is diagnosed when approximately 50% of the dopaminergic neurons of the substantia nigra pars compacta (SNpc) have degenerated and the others are already affected by the disease. Thus, it is conceivable that all therapeutic strategies, aimed at neuroprotection, start too late. Therefore, an urgent medical need exists to discover new pharmacological targets and novel drugs with disease-modifying properties. In this regard, modulation of endogenous adult neurogenesis toward a dopaminergic phenotype might provide a new strategy to target Parkinson’s disease by partially ameliorating the dopaminergic cell loss that occurs in this disorder. We have previously shown that a phosphodiesterase 7 (PDE7) inhibitor, S14, exerts potent neuroprotective and anti-inflammatory effects in different rodent models of Parkinson’s disease, indicating that this compound could represent a novel therapeutic agent to stop the dopaminergic cell loss that occurs during the progression of the disease. In this report we show that, in addition to its neuroprotective effect, the PDE7 inhibitor S14 is also able to induce endogenous neuroregenerative processes toward a dopaminergic phenotype. We describe a population of actively dividing cells that give rise to new neurons in the SNpc of hemiparkinsonian rats after treatment with S14. In conclusion, our data identify S14 as a novel regulator of dopaminergic neuron generation. Significance Parkinson’s disease is a neurodegenerative disorder characterized by the loss of dopaminergic neurons in the ventral midbrain. Currently, no cure and no effective disease-modifying therapy are available for Parkinson’s disease; therefore, an urgent medical need exists to discover new pharmacological targets and novel drugs for the treatment of this disorder. The present study reports that an inhibitor of the enzyme

Cigarette Smoke-Induced Emphysema and Pulmonary Hypertension Can Be Prevented by Phosphodiesterase 4 and 5 Inhibition in Mice

PubMed Central

Pichl, Alexandra; Bednorz, Mariola; Ghofrani, Hossein Ardeschir; Schermuly, Ralph Theo; Seeger, Werner; Grimminger, Friedrich; Weissmann, Norbert

2015-01-01

Rationale Chronic obstructive pulmonary disease (COPD) is a widespread disease, with no curative therapies available. Recent findings suggest a key role of NO and sGC-cGMP signaling for the pathogenesis of the disease. Previous data suggest a downregulation/inactivation of the cGMP producing soluble guanylate cyclase, and sGC stimulation prevented cigarette smoke-induced emphysema and pulmonary hypertension (PH) in mice. We thus aimed to investigate if the inhibition of the cGMP degrading phosphodiesterase (PDE)5 has similar effects. Results were compared to the effects of a PDE 4 inhibitor (cAMP elevating) and a combination of both. Methods C57BL6/J mice were chronically exposed to cigarette smoke and in parallel either treated with Tadalafil (PDE5 inhibitor), Piclamilast (PDE4 inhibitor) or both. Functional measurements (lung compliance, hemodynamics) and structural investigations (alveolar and vascular morphometry) as well as the heart ratio were determined after 6 months of tobacco smoke exposure. In addition, the number of alveolar macrophages in the respective lungs was counted. Results Preventive treatment with Tadalafil, Piclamilast or a combination of both almost completely prevented the development of emphysema, the increase in lung compliance, tidal volume, structural remodeling of the lung vasculature, right ventricular systolic pressure, and right ventricular hypertrophy induced by cigarette smoke exposure. Single, but not combination treatment prevented or reduced smoke-induced increase in alveolar macrophages. Conclusion Cigarette smoke-induced emphysema and PH could be prevented by inhibition of the phosphodiesterases 4 and 5 in mice. PMID:26058042

Role of phosphodiesterase-4 on ethanol elicited locomotion and narcosis.

PubMed

Baliño, Pablo; Ledesma, Juan Carlos; Aragon, Carlos M G

2016-02-01

The cAMP signaling pathway has emerged as an important modulator of the pharmacological effects of ethanol. In this respect, the cAMP-dependent protein kinase has been shown to play an important role in the modulation of several ethanol-induced behavioral actions. Cellular levels of cAMP are maintained by the activity of adenylyl cyclases and phosphodiesterases. In the present work we have focused on ascertaining the role of PDE4 in mediating the neurobehavioral effects of ethanol. For this purpose, we have used the selective PDE4 inhibitor Ro 20-1724. This compound has been proven to enhance cellular cAMP response by PDE4 blockade and can be administered systemically. Swiss mice were injected intraperitoneally (i.p.) with Ro 20-1724 (0-5 mg/kg; i.p.) at different time intervals before ethanol (0-4 g/kg; i.p.) administration. Immediately after the ethanol injection, locomotor activity, loss of righting reflex, PKA footprint and enzymatic activity were assessed. Pretreatment with Ro 20-1724 increased ethanol-induced locomotor stimulation in a dose-dependent manner. Doses that increased locomotor stimulation did not modify basal locomotion or the suppression of motor activity produced by high doses of this alcohol. Ro 20-1724 did not alter the locomotor activation produced by amphetamine or cocaine. The time of loss of righting reflex evoked by ethanol was increased after pretreatment with Ro 20-1724. This effect was selective for the narcotic effects of ethanol since Ro 20-1724 did not affect pentobarbital-induced narcotic effects. Moreover, Ro 20-1724 administration increased the PKA footprint and enzymatic activity response elicited by ethanol. These data provide further evidence of the key role of the cAMP signaling pathway in the central effects of ethanol. Copyright © 2015 Elsevier Ltd. All rights reserved.

Phosphodiesterase-4 inhibition combined with isoniazid treatment of rabbits with pulmonary tuberculosis reduces macrophage activation and lung pathology.

PubMed

Subbian, Selvakumar; Tsenova, Liana; O'Brien, Paul; Yang, Guibin; Koo, Mi-Sun; Peixoto, Blas; Fallows, Dorothy; Zeldis, Jerome B; Muller, George; Kaplan, Gilla

2011-07-01

Tuberculosis (TB) is responsible for significant morbidity and mortality worldwide. Even after successful microbiological cure of TB, many patients are left with residual pulmonary damage that can lead to chronic respiratory impairment and greater risk of additional TB episodes due to reinfection with Mycobacterium tuberculosis. Elevated levels of the proinflammatory cytokine tumor necrosis factor-α and several other markers of inflammation, together with expression of matrix metalloproteinases, have been associated with increased risk of pulmonary fibrosis, tissue damage, and poor treatment outcomes in TB patients. In this study, we used a rabbit model of pulmonary TB to evaluate the impact of adjunctive immune modulation, using a phosphodiesterase-4 inhibitor that dampens the innate immune response, on the outcome of treatment with the antibiotic isoniazid. Our data show that cotreatment of M. tuberculosis infected rabbits with the phosphodiesterase-4 inhibitor CC-3052 plus isoniazid significantly reduced the extent of immune pathogenesis, compared with antibiotic alone, as determined by histologic analysis of infected tissues and the expression of genes involved in inflammation, fibrosis, and wound healing in the lungs. Combined treatment with an antibiotic and CC-3052 not only lessened disease but also improved bacterial clearance from the lungs. These findings support the potential for adjunctive immune modulation to improve the treatment of pulmonary TB and reduce the risk of chronic respiratory impairment. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

A Role for Phosphodiesterase 11A (PDE11A) in the Formation of Social Memories and the Stabilization of Mood

PubMed Central

Kelly, Michy P.

2017-01-01

The most recently discovered 3′,5′-cyclic nucleotide phosphodiesterase family is the Phosphodiesterase 11 (PDE11) family, which is encoded by a single gene PDE11A. PDE11A is a dual-specific PDE, breaking down both cAMP and cGMP. There are four PDE11A splice variants (PDE11A1–4) with distinct tissue expression profiles and unique N-terminal regulatory regions, suggesting that each isoform could be individually targeted with a small molecule or biologic. PDE11A4 is the PDE11A isoform expressed in brain and is found in the hippocampal formation of humans and rodents. Studies in rodents show that PDE11A4 mRNA expression in brain is, in fact, restricted to the hippocampal formation (CA1, possibly CA2, subiculum, and the adjacently connected amygdalohippocampal area). Within the hippocampal formation of rodents, PDE11A4 protein is expressed in neurons but not astrocytes, with a distribution across nuclear, cytoplasmic, and membrane compartments. This subcellular localization of PDE11A4 is altered in response to social experience in mouse, and in vitro studies show the compartmentalization of PDE11A4 is controlled, at least in part, by homodimerization and N-terminal phosphorylation. PDE11A4 expression dramatically increases in the hippocampus with age in the rodent hippocampus, from early postnatal life to late aging, suggesting PDE11A4 function may evolve across the lifespan. Interestingly, PDE11A4 protein shows a 3–10-fold enrichment in the rodent ventral hippocampal formation (VHIPP; a.k.a. anterior in primates) versus dorsal hippocampal formation (DHIPP). Consistent with this enrichment in VHIPP, studies in knockout mice show that PDE11A regulates the formation of social memories and the stabilization of mood and is a critical mechanism by which social experience feeds back to modify the brain and subsequent social behaviors. PDE11A4 likely controls behavior by regulating hippocampal glutamatergic, oxytocin, and cytokine signaling, as well as protein

UCR1C is a novel activator of phosphodiesterase 4 (PDE4) long isoforms and attenuates cardiomyocyte hypertrophy.

PubMed

Wang, Li; Burmeister, Brian T; Johnson, Keven R; Baillie, George S; Karginov, Andrei V; Skidgel, Randal A; O'Bryan, John P; Carnegie, Graeme K

2015-05-01

Hypertrophy increases the risk of heart failure and arrhythmia. Prevention or reversal of the maladaptive hypertrophic phenotype has thus been proposed to treat heart failure. Chronic β-adrenergic receptor (β-AR) stimulation induces cardiomyocyte hypertrophy by elevating 3',5'-cyclic adenosine monophosphate (cAMP) levels and activating downstream effectors such protein kinase A (PKA). Conversely, hydrolysis of cAMP by phosphodiesterases (PDEs) spatiotemporally restricts cAMP signaling. Here, we demonstrate that PDE4, but not PDE3, is critical in regulating cardiomyocyte hypertrophy, and may represent a potential target for preventing maladaptive hypertrophy. We identify a sequence within the upstream conserved region 1 of PDE4D, termed UCR1C, as a novel activator of PDE4 long isoforms. UCR1C activates PDE4 in complex with A-kinase anchoring protein (AKAP)-Lbc resulting in decreased PKA signaling facilitated by AKAP-Lbc. Expression of UCR1C in cardiomyocytes inhibits hypertrophy in response to chronic β-AR stimulation. This effect is partially due to inhibition of nuclear PKA activity, which decreases phosphorylation of the transcription factor cAMP response element-binding protein (CREB). In conclusion, PDE4 activation by UCR1C attenuates cardiomyocyte hypertrophy by specifically inhibiting nuclear PKA activity. Published by Elsevier Inc.

Thyroid hormone and the brain: Mechanisms of action in development and role in protection and promotion of recovery after brain injury.

PubMed

Liu, Yan-Yun; Brent, Gregory A

2018-06-01

Thyroid hormone (TH) is essential for normal brain development and may also promote recovery and neuronal regeneration after brain injury. TH acts predominantly through the nuclear receptors, TH receptor alpha (THRA) and beta (THRB). Additional factors that impact TH action in the brain include metabolism, activation of thyroxine (T4) to triiodothyronine (T3) by the enzyme 5'-deiodinase Type 2 (Dio2), inactivation by the enzyme 5-deiodinase Type 3 (Dio3) to reverse T3 (rT3), which occurs in glial cells, and uptake by the Mct8 transporter in neurons. Traumatic brain injury (TBI) is associated with inflammation, metabolic alterations and neural death. In clinical studies, central hypothyroidism, due to hypothalamic and pituitary dysfunction, has been found in some individuals after brain injury. TH has been shown, in animal models, to be protective for the damage incurred from brain injury and may have a role to limit injury and promote recovery. Although clinical trials have not yet been reported, findings from in vitro and in vivo models inform potential treatment strategies utilizing TH for protection and promotion of recovery after brain injury. Published by Elsevier Inc.

Inhibition of phosphodiesterase 4 amplifies cytokine-dependent induction of arginase in macrophages.

PubMed

Erdely, Aaron; Kepka-Lenhart, Diane; Clark, Melissa; Zeidler-Erdely, Patti; Poljakovic, Mirjana; Calhoun, William J; Morris, Sidney M

2006-03-01

Arginase is greatly elevated in asthma and is thought to play a role in the pathophysiology of this disease. As inhibitors of phosphodiesterase 4 (PDE4), the predominant PDE in macrophages, elevate cAMP levels and reduce inflammation, they have been proposed for use in treatment of asthma and chronic obstructive pulmonary disease. As cAMP is an inducer of arginase, we tested the hypothesis that a PDE4 inhibitor would enhance macrophage arginase induction by key cytokines implicated in asthma and other pulmonary diseases. RAW 264.7 cells were stimulated with IL-4 or transforming growth factor (TGF)-beta, with and without the PDE4 inhibitor rolipram. IL-4 and TGF-beta increased arginase activity 16- and 5-fold, respectively. Rolipram alone had no effect but when combined with IL-4 and TGF-beta synergistically enhanced arginase activity by an additional 15- and 5-fold, respectively. The increases in arginase I protein and mRNA levels mirrored increases in arginase activity. Induction of arginase II mRNA was also enhanced by rolipram but to a much lesser extent than arginase I. Unlike its effect in RAW 264.7 cells, IL-4 alone did not increase arginase activity in human alveolar macrophages (AM) from healthy volunteers. However, combining IL-4 with agents to induce cAMP levels induced arginase activity in human AM significantly above the level obtained with cAMP-inducing agents alone. In conclusion, agents that elevate cAMP significantly enhance induction of arginase by cytokines. Therefore, consequences of increased arginase expression should be evaluated whenever PDE inhibitors are proposed for treatment of inflammatory disorders in which IL-4 and/or TGF-beta predominate.

Interactions of chlorphenesin and divalent metal ions with phosphodiesterase.

PubMed

Edelson, J; McMullen, J P

1976-09-01

Chlorphenesin inhibition of the hydrolysis of cyclic AMP by guinea-pig lung phosphodiesterase was reversed by the addition of exogenous magnesium ions. Chlorphenesin and theophylline inhibition of this enzyme was shown to be noncompetitive when the substrate concentration was low. Kinetic studies of the inhibition of beef heart phosphodiesterase by chlorphenesin and theophylline indicated that the substrate concentration was a factor in determining whether inhibition was competitive or noncompetitive. Calcium, cobalt and copper ions were inhibitory to guinea-pig lung phosphodiesterase. The inhibition due to chlorphenesin was partially reversed by low (40 mM or less) concentrations of barium ions; high concentrations of barium ions, or manganese ions, were inhibitory. The concentration of the divalent cation did not affect the type of inhibition that was observed.

Cloning and expression of cDNA for a human low-K sub m , rolipram-sensitive cyclic AMP phosphodiesterase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Livi, G.P.; McHale, M.J.; Sathe, G.M.

1990-06-01

The authors have isolated cDNA clones representing cyclic AMP (cAMP)-specific phosphodiesterases (PDEases) from a human monocyte cDNA library. One cDNA clone (hPDE-1) defines a large open reading frame of ca. 2.1 kilobases, predicting a 686-amino-acid, ca. 77-kilodalton protein which contains significant homology to both rat brain and {ital Drosophila} cAMP PDEases, especially within an internal conserved domain of ca. 270 residues. Amino acid sequence divergence exists at the NH{sub 2} terminus and also within a 40- to 100-residue domain near the COOH-terminal end. hPDE-1 hybridizes to a major 4.8-kilobase mRNA transcript from both human monocytes and placenta. The coding regionmore » of hPDE-1 was engineered for expression in COS-1 cells, resulting in the overproduction of cAMP PDEase activity. The hPDE-1 recombinant gene product was identified as a low-{ital K{sub m}} cAMP phosphodiesterase on the basis of several biochemical properties including selective inhibition by the antidepressant drug rolipram. Known inhibitors of other PDEases (cGMP-specific PDEase, cGMP-inhibited PDEase) had little or no effect on the hPDE-1 recombinant gene product.« less

Prominent expression of phosphodiesterase 5 in striated muscle of the rat urethra and levator ani.

PubMed

Lin, Guiting; Huang, Yun-Ching; Wang, Guifang; Lue, Tom F; Lin, Ching-Shwun

2010-08-01

We investigated phosphodiesterase 5 distribution and activity in the urethra. Rat tissues were examined for phosphodiesterase 5 and alpha-smooth muscle actin expression. Urethral phosphodiesterase 5 activity was examined by tissue bath in the presence of sildenafil (Pfizer, New York, New York). Anti-alpha-smooth muscle actin antibody (Abcam) stained all known smooth muscles in all tested tissues and revealed a few smooth muscle fibers in the levator ani muscle. Anti-phosphodiesterase 5 antibody (Abcam) stained smooth muscle in the penis and bladder but not striated leg muscle. However, it stained predominantly striated muscle in the urethra and the levator ani muscle. In the urethra the amount of phosphodiesterase 5 in striated muscle was 6 times that in smooth muscle. In urethral striated muscle phosphodiesterase 5 expression was localized to Z-band striations. Smooth and striated muscle intermingling was clearly visible on the inner and outer rims of the circularly arranged striated muscle layer. Relaxation of precontracted urethral tissues by sodium nitroprusside (Sigma-Aldrich) was enhanced by sildenafil, indicating phosphodiesterase 5 activity, which was primarily located in the striated muscle according to phosphodiesterase 5 staining. Despite its presumed smooth muscle specificity phosphodiesterase 5 was predominantly expressed in the striated muscle of the urethra and in the levator ani muscle. Results are consistent with earlier studies in which these striated muscles were developmentally related to smooth muscle. They also suggest that these striated muscles are possibly regulated by phosphodiesterase 5. Copyright (c) 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

ElaC encodes a novel binuclear zinc phosphodiesterase.

PubMed

Vogel, Andreas; Schilling, Oliver; Niecke, Manfred; Bettmer, Jorg; Meyer-Klaucke, Wolfram

2002-08-09

ElaC is a widespread gene found in eubacteria, archaebacteria, and mammals with a highly conserved sequence. Two human ElaC variants were recently associated with cancer (Tavtigian, S. V., Simard, J., Teng, D. H., Abtin, V., Baumgard, M., Beck, A., Camp, N. J., Carillo, A. R., Chen, Y., Dayananth, P., Desrochers, M., Dumont, M., Farnham, J. M., Frank, D., Frye, C., Ghaffari, S., Gupte, J. S., Hu, R., Iliev, D., Janecki, T., Kort, E. N., Laity, K. E., Leavitt, A., Leblanc, G., McArthur-Morrison, J., Pederson, A., Penn, B., Peterson, K. T., Reid, J. E., Richards, S., Schroeder, M., Smith, R., Snyder, S. C., Swedlund, B., Swensen, J., Thomas, A., Tranchant, M., Woodland, A. M., Labrie, F., Skolnick, M. H., Neuhausen, S., Rommens, J., and Cannon-Albright, L. A. (2001) Nat. Genet. 27, 172-180; Yanaihara, N., Kohno, T., Takakura, S., Takei, K., Otsuka, A., Sunaga, N., Takahashi, M., Yamazaki, M., Tashiro, H., Fukuzumi, Y., Fujimori, Y., Hagiwara, K., Tanaka, T., and Yokota, J. (2001) Genomics 72, 169-179). Analysis of the primary sequence indicates homology to an arylsulfatase and predicts a metallo-beta-lactamase fold. At present, no ElaC gene product has been investigated. We cloned the Escherichia coli ElaC gene and purified the recombinant gene product. An enzymatic analysis showed that ElaC does not encode an arylsulfatase but rather encodes a phosphodiesterase that hydrolyzes bis(p-nitrophenyl)phosphate with a k(cat) of 59 s(-1) and K' of 4 mm. Kinetic analysis of the dimeric enzyme revealed positive cooperativity for the substrate bis(p-nitrophenyl)phosphate with a Hill coefficient of 1.6, whereas hydrolysis of the substrate thymidine-5'-p-nitrophenyl phosphate followed Michaelis-Menten kinetics. Furthermore, the enzyme is capable of binding two zinc or two iron ions. However, it displays phosphodiesterase activity only in the zinc form. The metal environment characterized by zinc K-edge x-ray absorption spectroscopy was modeled with two histidine residues, one

Active site structure and catalytic mechanism of phosphodiesterase for degradation of intracellular second messengers

NASA Astrophysics Data System (ADS)

Zhan, Chang-Guo

2002-03-01

Phosphodiesterases are clinical targets for a variety of biological disorders, because this superfamily of enzymes regulate intracellular concentration of cyclic nucleotides that serve as the second messengers playing a critical role in a variety of physiological processes. Understanding structure and mechanism of a phosphodiesterase will provide a solid basis for rational design of the more efficient therapeutics. Although a three-dimensional X-ray crystal structure of the catalytic domain of human phosphodiesterase 4B2B was recently reported, it was uncertain whether a critical bridging ligand in the active site is a water molecule or a hydroxide ion. The identity of this bridging ligand has been determined by performing first-principles quantum chemical calculations on models of the active site. All the results obtained indicate that this critical bridging ligand in the active site of the reported X-ray crystal structure is a hydroxide ion, rather than a water molecule, expected to serve as the nucleophile to initialize the catalytic degradation of the intracellular second messengers.

A phosphodiesterase 4-controlled switch between memory extinction and strengthening in the hippocampus

PubMed Central

Roesler, Rafael; Reolon, Gustavo K.; Maurmann, Natasha; Schwartsmann, Gilberto; Schröder, Nadja; Amaral, Olavo B.; Valvassori, Samira; Quevedo, João

2014-01-01

Established fear-related memories can undergo phenomena such as extinction or reconsolidation when recalled. Extinction probably involves the creation of a new, competing memory trace that decreases fear expression, whereas reconsolidation can mediate memory maintenance, updating, or strengthening. The factors determining whether retrieval will initiate extinction, reconsolidation, or neither of these two processes include training intensity, duration of the retrieval session, and age of the memory. However, previous studies have not shown that the same behavioral protocol can be used to induce either extinction or reconsolidation and strengthening, depending on the pharmacological intervention used. Here we show that, within an experiment that leads to extinction in control rats, memory can be strengthened if rolipram, a selective inhibitor of phosphodiesterase type 4 (PDE4), is administered into the dorsal hippocampus immediately after retrieval. The memory-enhancing effect of rolipram lasted for at least 1 week, was blocked by the protein synthesis inhibitor anisomycin, and did not occur when drug administration was not paired with retrieval. These findings indicate that the behavioral outcome of memory retrieval can be pharmacologically switched from extinction to strengthening. The cAMP/protein kinase A (PKA) signaling pathway might be a crucial mechanism determining the fate of memories after recall. PMID:24672454

Phosphodiesterase 7 inhibitor reduced cognitive impairment and pathological hallmarks in a mouse model of Alzheimer's disease.

PubMed

Perez-Gonzalez, Rocio; Pascual, Consuelo; Antequera, Desiree; Bolos, Marta; Redondo, Miriam; Perez, Daniel I; Pérez-Grijalba, Virginia; Krzyzanowska, Agnieszka; Sarasa, Manuel; Gil, Carmen; Ferrer, Isidro; Martinez, Ana; Carro, Eva

2013-09-01

Elevated levels of amyloid beta (Aβ) peptide, hyperphosphorylation of tau protein, and inflammation are pathological hallmarks in Alzheimer's disease (AD). Phosphodiesterase 7 (PDE7) regulates the inflammatory response through the cyclic adenosine monophosphate signaling cascade, and thus plays a central role in AD. The aim of this study was to evaluate the efficacy of an inhibitor of PDE7, named S14, in a mouse model of AD. We report that APP/Ps1 mice treated daily for 4 weeks with S14 show: (1) significant attenuation in behavioral impairment; (2) decreased brain Aβ deposition; (3) enhanced astrocyte-mediated Aβ degradation; and (4) decreased tau phosphorylation. These effects are mediated via the cyclic adenosine monophosphate/cyclic adenosine monophosphate response element-binding protein signaling pathway, and inactivation of glycogen synthase kinase (GSK)3. Our data support the use of PDE7 inhibitors, and specifically S14, as effective therapeutic agents for the prevention and treatment of AD. Copyright © 2013 Elsevier Inc. All rights reserved.

Early Relief of Pruritus in Atopic Dermatitis with Crisaborole Ointment, A Non-steroidal, Phosphodiesterase 4 Inhibitor.

PubMed

Yosipovitch, Gil; Gold, Linda F; Lebwohl, Mark G; Silverberg, Jonathan I; Tallman, Anna M; Zane, Lee T

2018-04-27

Pruritus occurs in all patients with atopic dermatitis and requires quick relief to reduce disease exacerbation and improve quality of life. Crisaborole ointment is a non-steroidal phosphodiesterase 4 inhibitor for the treatment of mild-to-moderate atopic dermatitis. This post hoc analysis explores crisaborole ointment for early relief of pruritus in patients with mild to moderate atopic dermatitis from 2 phase III studies. Patients received crisaborole or vehicle twice daily for 28 days. Pruritus was graded on a 4-point scale of none (0) to severe (3). Early improvement in pruritus required a score of none (0) or mild (1), with a ≥ 1-grade improvement from baseline on day 6. Significantly more patients experienced early improvement in pruritus with crisaborole than with vehicle (56.6% vs 39.5%; p< 0.001), including at earliest assessment (day 2, 34.3% vs 27.3%; p = 0.013). Crisaborole is a topical treatment option that can rapidly relieve atopic dermatitis-associated pruritus.

Catecholic amides as potential selective phosphodiesterase 4D inhibitors: Design, synthesis, pharmacological evaluation and structure-activity relationships.

PubMed

Zhou, Zhong-Zhen; Ge, Bing-Chen; Chen, Yu-Fang; Shi, Xiu-Dong; Yang, Xue-Mei; Xu, Jiang-Ping

2015-11-15

In this study, a series of catechol-based amides (8a-n) with different amide linkers linking the catecholic moiety to the terminal phenyl ring was designed and synthesized as potent phosphodiesterase (PDE) 4D inhibitors. The inhibitory activities of these compounds were evaluated against the core catalytic domains of human PDE4 (PDE4CAT), full-length PDE4B1 and PDE4D7 enzymes, and other PDE family members. The results indicated the majority of compounds 8a-n displayed moderate to good inhibitory activities against PDE4CAT. Among these compounds, compound 8 j with a short amide linker (-CONHCH2-) displayed comparable PDE4CAT inhibitory activity (IC50=410 nM) with rolipram. More interestingly, compound 8 g, a potent and selective PDE4D inhibitor (IC50=94 nM), exhibited a 10-fold selectivity over the PDE4B subtypes and an over 1000-fold selectivity against other PDE family members. Docking simulations suggested that 8 g forms three extra H-bonds with the N-H of residue Asn487 and two water molecules. Copyright © 2015 Elsevier Ltd. All rights reserved.

Glycerophosphocholine metabolism in higher plant cells. Evidence of a new glyceryl-phosphodiester phosphodiesterase.

PubMed

van der Rest, Benoît; Boisson, Anne-Marie; Gout, Elisabeth; Bligny, Richard; Douce, Roland

2002-09-01

Glycerophosphocholine (GroPCho) is a diester that accumulates in different physiological processes leading to phospholipid remodeling. However, very little is known about its metabolism in higher plant cells. (31)P-Nuclear magnetic resonance spectroscopy and biochemical analyses performed on carrot (Daucus carota) cells fed with GroPCho revealed the existence of an extracellular GroPCho phosphodiesterase. This enzymatic activity splits GroPCho into sn-glycerol-3-phosphate and free choline. In vivo, sn-glycerol-3-phosphate is further hydrolyzed into glycerol and inorganic phosphate by acid phosphatase. We visualized the incorporation and the compartmentation of choline and observed that the major choline pool was phosphorylated and accumulated in the cytosol, whereas a minor fraction was incorporated in the vacuole as free choline. Isolation of plasma membranes, culture medium, and cell wall proteins enabled us to localize this phosphodiesterase activity on the cell wall. We also report the existence of an intracellular glycerophosphodiesterase. This second activity is localized in the vacuole and hydrolyzes GroPCho in a similar fashion to the cell wall phosphodiesterase. Both extra- and intracellular phosphodiesterases are widespread among different plant species and are often enhanced during phosphate deprivation. Finally, competition experiments on the extracellular phosphodiesterase suggested a specificity for glycerophosphodiesters (apparent K(m) of 50 microM), which distinguishes it from other phosphodiesterases previously described in the literature.

Aquaporin-4 facilitator TGN-073 promotes interstitial fluid circulation within the blood–brain barrier: [17O]H2O JJVCPE MRI study

PubMed Central

Huber, Vincent J.; Igarashi, Hironaka; Ueki, Satoshi; Kwee, Ingrid L.

2018-01-01

The blood–brain barrier (BBB), which imposes significant water permeability restriction, effectively isolates the brain from the systemic circulation. Seemingly paradoxical, the abundance of aquaporin-4 (AQP-4) on the inside of the BBB strongly indicates the presence of unique water dynamics essential for brain function. On the basis of the highly specific localization of AQP-4, namely, astrocyte end feet at the glia limitans externa and pericapillary Virchow–Robin space, we hypothesized that the AQP-4 system serves as an interstitial fluid circulator, moving interstitial fluid from the glia limitans externa to pericapillary Virchow–Robin space to ensure proper glymphatic flow draining into the cerebrospinal fluid. The hypothesis was tested directly using the AQP-4 facilitator TGN-073 developed in our laboratory, and [17O]H2O JJ vicinal coupling proton exchange MRI, a method capable of tracing water molecules delivered into the blood circulation. The results unambiguously showed that facilitation of AQP-4 by TGN-073 increased turnover of interstitial fluid through the system, resulting in a significant reduction in [17O]H2O contents of cortex with normal flux into the cerebrospinal fluid. The study further suggested that in addition to providing the necessary water for proper glymphatic flow, the AQP-4 system produces a water gradient within the interstitial space promoting circulation of interstitial fluid within the BBB. PMID:29481527

Aquaporin-4 facilitator TGN-073 promotes interstitial fluid circulation within the blood-brain barrier: [17O]H2O JJVCPE MRI study.

PubMed

Huber, Vincent J; Igarashi, Hironaka; Ueki, Satoshi; Kwee, Ingrid L; Nakada, Tsutomu

2018-06-13

The blood-brain barrier (BBB), which imposes significant water permeability restriction, effectively isolates the brain from the systemic circulation. Seemingly paradoxical, the abundance of aquaporin-4 (AQP-4) on the inside of the BBB strongly indicates the presence of unique water dynamics essential for brain function. On the basis of the highly specific localization of AQP-4, namely, astrocyte end feet at the glia limitans externa and pericapillary Virchow-Robin space, we hypothesized that the AQP-4 system serves as an interstitial fluid circulator, moving interstitial fluid from the glia limitans externa to pericapillary Virchow-Robin space to ensure proper glymphatic flow draining into the cerebrospinal fluid. The hypothesis was tested directly using the AQP-4 facilitator TGN-073 developed in our laboratory, and [O]H2O JJ vicinal coupling proton exchange MRI, a method capable of tracing water molecules delivered into the blood circulation. The results unambiguously showed that facilitation of AQP-4 by TGN-073 increased turnover of interstitial fluid through the system, resulting in a significant reduction in [O]H2O contents of cortex with normal flux into the cerebrospinal fluid. The study further suggested that in addition to providing the necessary water for proper glymphatic flow, the AQP-4 system produces a water gradient within the interstitial space promoting circulation of interstitial fluid within the BBB.

Creating an effective physical activity-based health promotion programme for adults with a brain injury.

PubMed

Driver, Simon; Irwin, Kelley; Woolsey, Anne; Pawlowski, Jill

2012-01-01

To describe the processes involved with developing and implementing a physical activity-based health promotion programme for people with a brain injury, summarize previous health promotion research efforts and provide an actual example of a programme entitled P.A.C.E, a 'Physical Activity Centred Education' programme. REASONING BEHIND LITERATURE SELECTION: Brain injury is a serious public health issue due to the incidence, complexity and high healthcare costs. Health promotion programmes that incorporate physical activity have been shown to improve the health of people with a disability. However, if programmes are to be successful they have to be appropriately designed, otherwise individuals will not adopt and maintain the desired health behaviours. Readers will have an understanding of (1) how a theoretical framework drives programme development, (2) the strategies required to facilitate behaviour change, (3) how previous research supports the use of a physical activity-based health promotion programme and (4) how to implement a programme. Future research ideas are provided so as to stimulate research in the area of physical activity-based health promotion programmes for people with a brain injury.

Human biodistribution and dosimetry of 18F-JNJ42259152, a radioligand for phosphodiesterase 10A imaging.

PubMed

Van Laere, Koen; Ahmad, Rawaha U; Hudyana, Hendra; Celen, Sofie; Dubois, Kristof; Schmidt, Mark E; Bormans, Guy; Koole, Michel

2013-01-01

Phosphodiesterase 10A (PDE10A) is a cAMP/cGMP-hydrolysing enzyme with a central role in striatal signalling and implicated in neuropsychiatric disorders such as Huntington's disease, Parkinson's disease, schizophrenia and addiction. We have developed a novel PDE10A PET ligand, (18)F-JNJ42259152, and describe here its human dynamic biodistribution, safety and dosimetry. Six male subjects (age range 23-67 years) underwent ten dynamic whole-body PET/CT scans over 6 h after bolus injection of 175.5 ± 9.4 MBq (18)F-JNJ42259152. Source organs were delineated on PET/CT and individual organ doses and effective dose were determined using the OLINDA software. F-JNJ42259152 was readily taken up by the brain and showed exclusive retention in the brain, especially in the striatum with good washout starting after 20 min. The tracer was cleared through both the hepatobiliary and the urinary routes. No defluorination was observed. Organ absorbed doses were largest for the gallbladder (239 μSv/MBq) and upper large intestine (138 μSv/MBq). The mean effective dose was 24.9 ± 4.1 μSv/MBq. No adverse events were encountered. In humans, (18)F-JNJ42259152 has an appropriate distribution, brain kinetics and safety. The estimated effective dose was within WHO class IIb with low interindividual variability. Therefore, the tracer is suitable for further kinetic evaluation in humans.

A regulatory toolbox of MiniPromoters to drive selective expression in the brain

PubMed Central

Portales-Casamar, Elodie; Swanson, Douglas J.; Liu, Li; de Leeuw, Charles N.; Banks, Kathleen G.; Ho Sui, Shannan J.; Fulton, Debra L.; Ali, Johar; Amirabbasi, Mahsa; Arenillas, David J.; Babyak, Nazar; Black, Sonia F.; Bonaguro, Russell J.; Brauer, Erich; Candido, Tara R.; Castellarin, Mauro; Chen, Jing; Chen, Ying; Cheng, Jason C. Y.; Chopra, Vik; Docking, T. Roderick; Dreolini, Lisa; D'Souza, Cletus A.; Flynn, Erin K.; Glenn, Randy; Hatakka, Kristi; Hearty, Taryn G.; Imanian, Behzad; Jiang, Steven; Khorasan-zadeh, Shadi; Komljenovic, Ivana; Laprise, Stéphanie; Liao, Nancy Y.; Lim, Jonathan S.; Lithwick, Stuart; Liu, Flora; Liu, Jun; Lu, Meifen; McConechy, Melissa; McLeod, Andrea J.; Milisavljevic, Marko; Mis, Jacek; O'Connor, Katie; Palma, Betty; Palmquist, Diana L.; Schmouth, Jean-François; Swanson, Magdalena I.; Tam, Bonny; Ticoll, Amy; Turner, Jenna L.; Varhol, Richard; Vermeulen, Jenny; Watkins, Russell F.; Wilson, Gary; Wong, Bibiana K. Y.; Wong, Siaw H.; Wong, Tony Y. T.; Yang, George S.; Ypsilanti, Athena R.; Jones, Steven J. M.; Holt, Robert A.; Goldowitz, Daniel; Wasserman, Wyeth W.; Simpson, Elizabeth M.

2010-01-01

The Pleiades Promoter Project integrates genomewide bioinformatics with large-scale knockin mouse production and histological examination of expression patterns to develop MiniPromoters and related tools designed to study and treat the brain by directed gene expression. Genes with brain expression patterns of interest are subjected to bioinformatic analysis to delineate candidate regulatory regions, which are then incorporated into a panel of compact human MiniPromoters to drive expression to brain regions and cell types of interest. Using single-copy, homologous-recombination “knockins” in embryonic stem cells, each MiniPromoter reporter is integrated immediately 5′ of the Hprt locus in the mouse genome. MiniPromoter expression profiles are characterized in differentiation assays of the transgenic cells or in mouse brains following transgenic mouse production. Histological examination of adult brains, eyes, and spinal cords for reporter gene activity is coupled to costaining with cell-type–specific markers to define expression. The publicly available Pleiades MiniPromoter Project is a key resource to facilitate research on brain development and therapies. PMID:20807748

A regulatory toolbox of MiniPromoters to drive selective expression in the brain.

PubMed

Portales-Casamar, Elodie; Swanson, Douglas J; Liu, Li; de Leeuw, Charles N; Banks, Kathleen G; Ho Sui, Shannan J; Fulton, Debra L; Ali, Johar; Amirabbasi, Mahsa; Arenillas, David J; Babyak, Nazar; Black, Sonia F; Bonaguro, Russell J; Brauer, Erich; Candido, Tara R; Castellarin, Mauro; Chen, Jing; Chen, Ying; Cheng, Jason C Y; Chopra, Vik; Docking, T Roderick; Dreolini, Lisa; D'Souza, Cletus A; Flynn, Erin K; Glenn, Randy; Hatakka, Kristi; Hearty, Taryn G; Imanian, Behzad; Jiang, Steven; Khorasan-zadeh, Shadi; Komljenovic, Ivana; Laprise, Stéphanie; Liao, Nancy Y; Lim, Jonathan S; Lithwick, Stuart; Liu, Flora; Liu, Jun; Lu, Meifen; McConechy, Melissa; McLeod, Andrea J; Milisavljevic, Marko; Mis, Jacek; O'Connor, Katie; Palma, Betty; Palmquist, Diana L; Schmouth, Jean-François; Swanson, Magdalena I; Tam, Bonny; Ticoll, Amy; Turner, Jenna L; Varhol, Richard; Vermeulen, Jenny; Watkins, Russell F; Wilson, Gary; Wong, Bibiana K Y; Wong, Siaw H; Wong, Tony Y T; Yang, George S; Ypsilanti, Athena R; Jones, Steven J M; Holt, Robert A; Goldowitz, Daniel; Wasserman, Wyeth W; Simpson, Elizabeth M

2010-09-21

The Pleiades Promoter Project integrates genomewide bioinformatics with large-scale knockin mouse production and histological examination of expression patterns to develop MiniPromoters and related tools designed to study and treat the brain by directed gene expression. Genes with brain expression patterns of interest are subjected to bioinformatic analysis to delineate candidate regulatory regions, which are then incorporated into a panel of compact human MiniPromoters to drive expression to brain regions and cell types of interest. Using single-copy, homologous-recombination "knockins" in embryonic stem cells, each MiniPromoter reporter is integrated immediately 5' of the Hprt locus in the mouse genome. MiniPromoter expression profiles are characterized in differentiation assays of the transgenic cells or in mouse brains following transgenic mouse production. Histological examination of adult brains, eyes, and spinal cords for reporter gene activity is coupled to costaining with cell-type-specific markers to define expression. The publicly available Pleiades MiniPromoter Project is a key resource to facilitate research on brain development and therapies.

K-134, a Phosphodiesterase 3 Inhibitor, Prevents Brain Damage by Inhibiting Thrombus Formation in a Rat Cerebral Infarction Model

PubMed Central

Yoshida, Hideo; Ashikawa, Yuka; Itoh, Shinsuke; Nakagawa, Takashi; Asanuma, Akimune; Tanabe, Sohei; Inoue, Yoshihiro; Hidaka, Hiroyoshi

2012-01-01

Background K-134 is a more potent antiplatelet drug with a selective inhibitory effect on phosphodiesterase 3 (PDE3) compared with its analogue, cilostazol. Objectives This study was performed to compare the ameliorating effects of K-134 and cilostazol on brain damage in an experimental photothrombotic cerebral infarction model. Methods and Results We investigated the effects of oral preadministration of PDE3 inhibitors in a rat stroke model established by photothrombotic middle cerebral artery (MCA) occlusion. K-134 significantly prolonged MCA occlusion time at doses >10 mg/kg, and reduced cerebral infarct size at 30 mg/kg in the stroke model (n = 12, 87.5±5.6 vs. 126.8±7.5 mm3, P<0.01), indicating its potent antithrombotic effect. On the other hand, the effects of cilostazol on MCA occlusion time and cerebral infarct size are relatively weak even at the high dosage of 300 mg/kg. Furthermore, K-134 blocked rat platelet aggregation more potently than cilostazol in vitro. Also in an arteriovenous shunt thrombosis model, K-134 showed an antithrombotic effect greater than cilostazol. Conclusions These findings suggest that K-134, which has strong antithrombotic activity, is a promising drug for prevention of cerebral infarction associated with platelet hyperaggregability. PMID:23110051

K-134, a phosphodiesterase 3 inhibitor, prevents brain damage by inhibiting thrombus formation in a rat cerebral infarction model.

PubMed

Yoshida, Hideo; Ashikawa, Yuka; Itoh, Shinsuke; Nakagawa, Takashi; Asanuma, Akimune; Tanabe, Sohei; Inoue, Yoshihiro; Hidaka, Hiroyoshi

2012-01-01

K-134 is a more potent antiplatelet drug with a selective inhibitory effect on phosphodiesterase 3 (PDE3) compared with its analogue, cilostazol. This study was performed to compare the ameliorating effects of K-134 and cilostazol on brain damage in an experimental photothrombotic cerebral infarction model. We investigated the effects of oral preadministration of PDE3 inhibitors in a rat stroke model established by photothrombotic middle cerebral artery (MCA) occlusion. K-134 significantly prolonged MCA occlusion time at doses >10 mg/kg, and reduced cerebral infarct size at 30 mg/kg in the stroke model (n = 12, 87.5±5.6 vs. 126.8±7.5 mm(3), P<0.01), indicating its potent antithrombotic effect. On the other hand, the effects of cilostazol on MCA occlusion time and cerebral infarct size are relatively weak even at the high dosage of 300 mg/kg. Furthermore, K-134 blocked rat platelet aggregation more potently than cilostazol in vitro. Also in an arteriovenous shunt thrombosis model, K-134 showed an antithrombotic effect greater than cilostazol. These findings suggest that K-134, which has strong antithrombotic activity, is a promising drug for prevention of cerebral infarction associated with platelet hyperaggregability.

Phosphodiesterase 4B plays a role in benzophenone-3-induced phototoxicity in normal human keratinocytes.

PubMed

Kim, Hyoung-June; Lee, Eunyoung; Lee, Moonyoung; Ahn, Sungjin; Kim, Jungmin; Liu, Jingjing; Jin, Sun Hee; Ha, Jaehyoun; Bae, Il Hong; Lee, Tae Ryong; Noh, Minsoo

2018-01-01

Benzophenone-3 (BP-3), which is extensively used in organic sunscreen, has phototoxic potential in human skin. Phosphodiesterase 4B (PDE4B) has a well-established role in inflammatory responses in immune cells. Currently, it is unknown if PDE4B is associated with BP-3-induced phototoxicity in normal human keratinocytes (NHKs). We found that BP-3 significantly increased PDE4B expression in ultraviolet B (UVB)-irradiated NHKs. Notably, BP-8, a sunscreen agent that shares the 2-hydroxy-4-methoxyphenyl methanone moiety with BP-3, also upregulated PDE4B expression in NHKs. Upon UVB irradiation, BP-3 upregulated the expression of pro-inflammatory factors, such as prostaglandin endoperoxide synthase 2, tumor necrosis factor α, interleukin 8, and S100A7, and downregulated the level of cornified envelope associated proteins, which are important in the development of the epidermal permeability barrier. The additive effects of UVB-activated BP-3 on the expression of both pro-inflammatory mediators and cornified envelope associated proteins were antagonized by treatment with the PDE4 inhibitor rolipram. The BP-3 and UVB co-stimulation-induced PDE4B upregulation and its association with the upregulation of pro-inflammatory mediators and the downregulation of epidermal differentiation markers were confirmed in a reconstituted three dimensional human epidermis model. Therefore, PDE4B has a role in the mechanism of BP-3-induced phototoxicity. Copyright © 2017 Elsevier Inc. All rights reserved.

cAMP-specific PDE4 Phosphodiesterases and AIP in the Pathogenesis of Pituitary Tumors

PubMed Central

Bolger, Graeme B.; Bizzi, Mariana Ferreira; Brant Pinheiro, Sergio Veloso; Trivellin, Giampaolo; Smoot, Lisa; Accavitti, Mary-Ann; Korbonits, Márta; Ribeiro-Oliveira, Antonio

2016-01-01

PDE4 cyclic nucleotide phosphodiesterases regulate cAMP abundance in cells and thereby regulate numerous processes, including cell growth and differentiation. The rat PDE4A5 isoform (human homologue PDE4A4) interacts with the AIP protein (also called XAP2 or ARA-9). Germline mutations in AIP occur in approximately 20% of patients with Familial Isolated Pituitary Adenoma (FIPA) and 20% of childhood-onset simplex somatotroph adenomas. We therefore examined the protein expression of PDE4A4 and the closely-related isoform PDE4A8 in normal human pituitary tissue and in pituitary adenomas. PDE4A4 had low expression in normal pituitary, but was significantly over-expressed in somatotroph, lactotroph, corticotroph and clinically non-functioning gonadotroph adenomas (P<0.0001 for all subtypes). Likewise, PDE4A8 was expressed in normal pituitary and was also significantly over-expressed in the adenoma subtypes (P<0.0001 for all). Among the different adenoma subtypes, corticotroph and lactotroph adenomas were the highest and lowest expressed for PDE4A4, respectively, whereas the opposite was observed for PDE4A8. Naturally occurring oncogenic variants in AIP were shown by a two-hybrid assay to disrupt the ability of AIP to interact with PDE4A5. A reverse-two-hybrid screen identified numerous additional variants in the TPR region of AIP that also disrupted its ability to interact with PDE4A5. The expression of PDE4A4 and PDE4A8 in normal pituitary, their increased expression in adenomatous pituitary cells where AIP is meant to participate, and the disruption of the PDE4A4-AIP interaction by AIP mutants may play a role in pituitary tumorigenesis. PMID:27267386

Phosphodiesterase-4 inhibition as a therapeutic approach to treat capillary leakage in systemic inflammation.

PubMed

Schick, Martin Alexander; Wunder, Christian; Wollborn, Jakob; Roewer, Norbert; Waschke, Jens; Germer, Christoph-Thomas; Schlegel, Nicolas

2012-06-01

In sepsis and systemic inflammation, increased microvascular permeability and consecutive breakdown of microcirculatory flow significantly contribute to organ failure and death. Evidence points to a critical role of cAMP levels in endothelial cells to maintain capillary endothelial barrier properties in acute inflammation. However, approaches to verify this observation in systemic models are rare. Therefore we tested here whether systemic application of the phosphodiesterase-4-inhibitors (PD-4-Is) rolipram or roflumilast to increase endothelial cAMP was effective to attenuate capillary leakage and breakdown of microcirculatory flow in severe lipopolysaccharide (LPS)-induced systemic inflammation in rats. Measurements of cAMP in mesenteric microvessels demonstrated significant LPS-induced loss of cAMP levels which was blocked by application of rolipram. Increased endothelial cAMP by application of either PD-4-I rolipram or roflumilast led to stabilization of endothelial barrier properties as revealed by measurements of extravasated FITC-albumin in postcapillary mesenteric venules. Accordingly, microcirculatory flow in mesenteric venules was significantly increased following PD-4-I treatment and blood gas analyses indicated improved metabolism. Furthermore application of PD-4-I after manifestation of LPS-induced systemic inflammation and capillary leakage therapeutically stabilized endothelial barrier properties as revealed by significantly reduced volume resuscitation for haemodynamic stabilization. Accordingly microcirculation was significantly improved following treatment with PD-4-Is. Our results demonstrate that inflammation-derived loss of endothelial cAMP contributes to capillary leakage which was blocked by systemic PD-4-I treatment. Therefore these data suggest a highly clinically relevant and applicable approach to stabilize capillary leakage in sepsis and systemic inflammation.

Blockade of phosphodiesterase 4 reverses morphine-induced ventilatory disturbance without loss of analgesia.

PubMed

Kimura, Satoko; Ohi, Yoshiaki; Haji, Akira

2015-04-15

Ventilatory disturbance is a fatal side-effect of opioid analgesics. Separation of analgesia from ventilatory depression is important for therapeutic use of opioids. It has been suggested that opioid-induced ventilatory depression results from a decrease in adenosine 3',5'-cyclic monophosphate content in the respiratory-related neurons. Therefore, we examined the effects of caffeine, a methylxanthine non-selective phosphodiesterase (PDE) inhibitor with adenosine antagonistic activity, and rolipram, a racetam selective PDE4 inhibitor, on ventilatory depression induced by morphine. Spontaneous ventilation and paw withdrawal responses to nociceptive thermal stimulation were measured in anesthetized rats simultaneously. The efferent discharge of the phrenic nerve was recorded in anesthetized, vagotomized, paralyzed and artificially ventilated rats. Rolipram (0.1 and 0.3 mg/kg, i.v.) and caffeine (3.0 and 10.0 mg/kg, i.v.) relieved morphine (1.0 mg/kg, i.v.)-induced ventilatory depression but had no discernible effect on its analgesic action. Rolipram (0.3 and 1.0 mg/kg, i.v.) and caffeine (10.0 and 20.0 mg/kg, i.v.) recovered morphine (3.0 mg/kg, i.v.)-induced prolongation and flattening of inspiratory discharge in the phrenic nerve. Inhibition of PDE4 may be a possible approach for overcoming morphine-induced ventilatory depression without loss of analgesia. Copyright © 2015 Elsevier Inc. All rights reserved.

Phosphodiesterase type 4 inhibition enhances nitric oxide- and hydrogen sulfide-mediated bladder neck inhibitory neurotransmission.

PubMed

Agis-Torres, Ángel; Recio, Paz; López-Oliva, María Elvira; Martínez, María Pilar; Barahona, María Victoria; Benedito, Sara; Bustamante, Salvador; Jiménez-Cidre, Miguel Ángel; García-Sacristán, Albino; Prieto, Dolores; Fernandes, Vítor S; Hernández, Medardo

2018-03-16

Nitric oxide (NO) and hydrogen sulfide (H 2 S) play a pivotal role in nerve-mediated relaxation of the bladder outflow region. In the bladder neck, a marked phosphodiesterase type 4 (PDE4) expression has also been described and PDE4 inhibitors, as rolipram, produce smooth muscle relaxation. This study investigates the role of PDE4 isoenzyme in bladder neck gaseous inhibitory neurotransmission. We used Western blot and double immunohistochemical staining for the detection of NPP4 (PDE4) and PDE4A and organ baths for isometric force recording to roflumilast and tadalafil, PDE4 and PDE5, respectively, inhibitors in pig and human samples. Endogenous H 2 S production measurement and electrical field stimulation (EFS) were also performed. A rich PDE4 and PDE4A expression was observed mainly limited to nerve fibers of the smooth muscle layer of both species. Moreover, roflumilast produced a much more potent smooth muscle relaxation than that induced by tadalafil. In porcine samples, H 2 S generation was diminished by H 2 S and NO synthase inhibition and augmented by roflumilast. Relaxations elicited by EFS were potentiated by roflumilast. These results suggest that PDE4, mainly PDE4A, is mostly located within nerve fibers of the pig and human bladder neck, where roflumilast produces a powerful smooth muscle relaxation. In pig, the fact that roflumilast increases endogenous H 2 S production and EFS-induced relaxations suggests a modulation of PDE4 on NO- and H 2 S-mediated inhibitory neurotransmission.

Association of Phosphodiesterase 4D with ischemic stroke: a population-based case-control study.

PubMed

Woo, Daniel; Kaushal, Ritesh; Kissela, Brett; Sekar, Padmini; Wolujewicz, Michael; Pal, Prodipto; Alwell, Kathleen; Haverbusch, Mary; Ewing, Irene; Miller, Rosie; Kleindorfer, Dawn; Flaherty, Matthew; Chakraborty, Ranajit; Deka, Ranjan; Broderick, Joseph

2006-02-01

The Phosphodiesterase 4D (PDE4D) gene was reported recently to be associated with ischemic stroke in an Icelandic population. The association was found predominately with large vessel and cardioembolic stroke. However, 2 recent reports were unable to confirm this association, although a trend toward association with cardioembolic stroke was reported. None of the reports included significant proportions of blacks. We tested for genotype and haplotype association of polymorphisms of the PDE4D gene with ischemic stroke in a population-based, biracial, case-control study. A total of 357 cases of ischemic stroke and 482 stroke-free controls from the same community were examined. Single nucleotide polymorphisms (SNPs) were chosen based on significant associations reported previously. Linkage disequilibrium (LD), SNP, and haplotype association analysis was performed using PHASE 2.0 and Haploview 3.2. Although several univariate associations were identified, only 1 SNP (rs2910829) was found to be significantly associated with cardioembolic stroke among both whites and blacks. The rs152312 SNP was associated with cardioembolic stroke among whites after multiple comparison corrections. The same SNP was not associated with cardioembolic stroke among blacks. However, significant haplotype association was identified for both whites and blacks for all ischemic stroke, cardioembolic stroke, and stroke of unknown origin. Haplotype association was identified for small vessel stroke among whites. PDE4D is a risk factor for ischemic stroke and, in particular, for cardioembolic stroke, among whites and blacks. Further study of this gene is warranted.

Interaction of divalent metal ions with Zn(2+)-glycerophosphocholine cholinephosphodiesterase from ox brain.

PubMed

Lee, K J; Kim, M R; Kim, Y B; Myung, P K; Sok, D E

1997-12-01

The effect of divalent metal ions on the activity of glycerophosphocholine cholinephosphodiesterse from ox brain was examined. Zn(2+)- and Co(2+)-glycerophosphocholine cholinephosphodiesterases were prepared from the exposure of apoenzyme to Zn2+ and Co2+, respectively, and the properties of two metallo-phosphodiesterases were compared to those of native phosphodiesterase. Although two metallo-enzymes were similar in expressing Km value, optimum pH or sensitivity to Cu2+, they differed in the susceptibility to the inhibition by thiocholine or tellurite; while Co(2+)-phosphodiesterase was more sensitive to tellurites, Zn(2+)-phosphodiesterase was more susceptible to inhibition by thiocholine. In addition, Zn(2+)-phosphodiesterase was more thermo-stable than Co2+ enzyme. Separately, when properties of native phosphodiesterase were compared to those of each metallo-phosphodiesterase, native phosphodiesterase was found to be quite similar to Zn(2+)-phosphodiesterase in many respects. Even in thermo-stability, native enzyme resembled Zn(2+)-phosphodiesterase rather than Co(2+)-enzyme. Consistent with this, the stability of native phosphodiesterase was maintained in the presence of Zn2+, but not Co2+, Mn2+ was also as effective as Zn2+ in the stabilization of the enzyme. Noteworthy, the native enzyme was found to be inhibited competitively by Cu2+ with a Ki value of 20 microM, and its inhibitory action was antagonized effectively by Zn2+ or Co2+. Also, choline, another competitive inhibitor of the enzyme, appeared to antagonize the inhibitory action of Cu2+. Taken together, it is suggested that there may be multiple binding sites for divalent metal ions in the molecule of glycerophosphocholine cholinephosphodiesterase.

Multiple Behavior Phenotypes of the Fragile-X Syndrome Mouse Model Respond to Chronic Inhibition of Phosphodiesterase-4D (PDE4D).

PubMed

Gurney, Mark E; Cogram, Patricia; Deacon, Robert M; Rex, Christopher; Tranfaglia, Michael

2017-11-07

Fragile-X syndrome (FXS) patients display intellectual disability and autism spectrum disorder due to silencing of the X-linked, fragile-X mental retardation-1 (FMR1) gene. Dysregulation of cAMP metabolism is a consistent finding in patients and in the mouse and fly FXS models. We therefore explored if BPN14770, a prototypic phosphodiesterase-4D negative allosteric modulator (PDE4D-NAM) in early human clinical trials, might provide therapeutic benefit in the mouse FXS model. Daily treatment of adult male fmr1 C57Bl6 knock-out mice with BPN14770 for 14 days reduced hyperarousal, improved social interaction, and improved natural behaviors such as nesting and marble burying as well as dendritic spine morphology. There was no decrement in behavioral scores in control C57Bl6 treated with BPN14770. The behavioral benefit of BPN14770 persisted two weeks after washout of the drug. Thus, BPN14770 may be useful for the treatment of fragile-X syndrome and other disorders with decreased cAMP signaling.

Synthesis, Pharmacological Profile and Docking Studies of New Sulfonamides Designed as Phosphodiesterase-4 Inhibitors

PubMed Central

Cardozo, Suzana Vanessa S.; Carvalho, Vinicius de Frias; Romeiro, Nelilma Correia; Silva, Patrícia Machado Rodrigues e; Martins, Marco Aurélio; Barreiro, Eliezer J.; Lima, Lídia Moreira

2016-01-01

Prior investigations showed that increased levels of cyclic AMP down-regulate lung inflammatory changes, stimulating the interest in phosphodiesterase (PDE)4 as therapeutic target. Here, we described the synthesis, pharmacological profile and docking properties of a novel sulfonamide series (5 and 6a-k) designed as PDE4 inhibitors. Compounds were screened for their selectivity against the four isoforms of human PDE4 using an IMAP fluorescence polarized protocol. The effect on allergen- or LPS-induced lung inflammation and airway hyper-reactivity (AHR) was studied in A/J mice, while the xylazine/ketamine-induced anesthesia test was employed as a behavioral correlate of emesis in rodents. As compared to rolipram, the most promising screened compound, 6a (LASSBio-448) presented a better inhibitory index concerning PDE4D/PDE4A or PDE4D/PDE4B. Accordingly, docking analyses of the putative interactions of LASSBio-448 revealed similar poses in the active site of PDE4A and PDE4C, but slight unlike orientations in PDE4B and PDE4D. LASSBio-448 (100 mg/kg, oral), 1 h before provocation, inhibited allergen-induced eosinophil accumulation in BAL fluid and lung tissue samples. Under an interventional approach, LASSBio-448 reversed ongoing lung eosinophilic infiltration, mucus exacerbation, peribronchiolar fibrosis and AHR by allergen provocation, in a mechanism clearly associated with blockade of pro-inflammatory mediators such as IL-4, IL-5, IL-13 and eotaxin-2. LASSBio-448 (2.5 and 10 mg/kg) also prevented inflammation and AHR induced by LPS. Finally, the sulfonamide derivative was shown to be less pro-emetic than rolipram and cilomilast in the assay employed. These findings suggest that LASSBio-448 is a new PDE4 inhibitor with marked potential to prevent and reverse pivotal pathological features of diseases characterized by lung inflammation, such as asthma. PMID:27695125

Clinical effects of phosphodiesterase 3A mutations in inherited hypertension with brachydactyly.

PubMed

Toka, Okan; Tank, Jens; Schächterle, Carolin; Aydin, Atakan; Maass, Philipp G; Elitok, Saban; Bartels-Klein, Eireen; Hollfinger, Irene; Lindschau, Carsten; Mai, Knut; Boschmann, Michael; Rahn, Gabriele; Movsesian, Matthew A; Müller, Thomas; Doescher, Andrea; Gnoth, Simone; Mühl, Astrid; Toka, Hakan R; Wefeld-Neuenfeld, Yvette; Utz, Wolfgang; Töpper, Agnieszka; Jordan, Jens; Schulz-Menger, Jeanette; Klussmann, Enno; Bähring, Sylvia; Luft, Friedrich C

2015-10-01

Autosomal-dominant hypertension with brachydactyly is a salt-independent Mendelian syndrome caused by activating mutations in the gene encoding phosphodiesterase 3A. These mutations increase the protein kinase A-mediated phosphorylation of phosphodiesterase 3A resulting in enhanced cAMP-hydrolytic affinity and accelerated cell proliferation. The phosphorylated vasodilator-stimulated phosphoprotein is diminished, and parathyroid hormone-related peptide is dysregulated, potentially accounting for all phenotypic features. Untreated patients die prematurely of stroke; however, hypertension-induced target-organ damage is otherwise hardly apparent. We conducted clinical studies of vascular function, cardiac functional imaging, platelet function in affected and nonaffected persons, and cell-based assays. Large-vessel and cardiac functions indeed seem to be preserved. The platelet studies showed normal platelet function. Cell-based studies demonstrated that available phosphodiesterase 3A inhibitors suppress the mutant isoforms. However, increasing cGMP to indirectly inhibit the enzyme seemed to have particular use. Our results shed more light on phosphodiesterase 3A activation and could be relevant to the treatment of severe hypertension in the general population. © 2015 American Heart Association, Inc.

Benzoquinones and terphenyl compounds as phosphodiesterase-4B inhibitors from a fungus of the order Chaetothyriales (MSX 47445).

PubMed

El-Elimat, Tamam; Figueroa, Mario; Raja, Huzefa A; Graf, Tyler N; Adcock, Audrey F; Kroll, David J; Day, Cynthia S; Wani, Mansukh C; Pearce, Cedric J; Oberlies, Nicholas H

2013-03-22

Three bioactive compounds were isolated from an organic extract of an ascomycete fungus of the order Chaetothyriales (MSX 47445) using bioactivity-directed fractionation as part of a search for anticancer leads from filamentous fungi. Of these, two were benzoquinones [betulinan A (1) and betulinan C (3)], and the third was a terphenyl compound, BTH-II0204-207:A (2). The structures were elucidated using a set of spectroscopic and spectrometric techniques; the structure of the new compound (3) was confirmed via single-crystal X-ray diffraction. Compounds 1-3 were evaluated for cytotoxicity against a human cancer cell panel, for antimicrobial activity against Staphylococcus aureus and Candida albicans, and for phosphodiesterase (PDE4B2) inhibitory activities. The putative binding mode of 1-3 with PDE4B2 was examined using a validated docking protocol, and the binding and enzyme inhibitory activities were correlated.

The effect of cilostazol, a phosphodiesterase 3 (PDE3) inhibitor, on human hair growth with the dual promoting mechanisms.

PubMed

Choi, Hye-In; Kim, Dong Young; Choi, Soon-Jin; Shin, Chang-Yup; Hwang, Sungjoo Tommy; Kim, Kyu Han; Kwon, Ohsang

2018-07-01

Cilostazol, a phosphodiesterase 3 (PDE3) inhibitor, increases the intracellular level of cyclic adenosine monophosphate to cause vasodilation. Topical application of cilostazol is reported to improve local blood flow and enhance wound healing; however, its effect on human hair follicles is unknown. The purpose of this study was to determine the effect of cilostazol on hair growth. We investigated the expression of PDE3 in human dermal papilla cells (DPCs), outer root sheath cells (ORSCs), and hair follicles. The effects of cilostazol on DPC and ORSC proliferation were evaluated using BrdU and WST-1 assays. The expression of various growth factors in DPCs was investigated by growth factor antibody array. Additionally, hair shaft elongation was measured using ex vivo hair follicle organ cultures, and anagen induction was evaluated in C57BL/6 mice. Finally, the effects of cilostazol on vessel formation and activation of the mitogen-activated protein kinase pathway were evaluated. We confirmed high mRNA and protein expression of PDE3 in human DPCs. Cilostazol not only enhanced the proliferation of human DPCs but also regulated the secretion of several growth factors responsible for hair growth. Furthermore, it promoted hair shaft elongation ex vivo, with increased proliferation of matrix keratinocytes. Cilostazol also accelerated anagen induction by stimulating vessel formation and upregulating the levels of phosphorylated extracellular signal-regulated kinase, c-Jun N-terminal kinase, and P38 after its topical application in C57BL/6 mice. Our results show that cilostazol promotes hair growth and may serve as a therapeutic agent for the treatment of alopecia. Copyright © 2018 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

Improvement of spatial memory function in APPswe/PS1dE9 mice after chronic inhibition of phosphodiesterase type 4D.

PubMed

Sierksma, A S R; van den Hove, D L A; Pfau, F; Philippens, M; Bruno, O; Fedele, E; Ricciarelli, R; Steinbusch, H W M; Vanmierlo, T; Prickaerts, J

2014-02-01

Phosphodiesterase type 4 inhibitors (PDE4-Is) have received increasing attention as cognition-enhancers and putative treatment strategies for Alzheimer's disease (AD). By preventing cAMP breakdown, PDE4-Is can enhance intracellular signal transduction and increase the phosphorylation of cAMP response element-binding protein (CREB) and transcription of proteins related to synaptic plasticity and associated memory formation. Unfortunately, clinical development of PDE4-Is has been seriously hampered by emetic side effects. The new isoform-specific PDE4D-I, GEBR-7b, has shown to have beneficial effects on memory at non-emetic doses. The aim of the current study was to investigate chronic cognition-enhancing effects of GEBR-7b in a mouse model of AD. To this extent, 5-month-old (5M) APPswe/PS1dE9 mice received daily subcutaneous injections with GEBR-7b (0.001 mg/kg) or vehicle for a period of 3 weeks, and were tested on affective and cognitive behavior at 7M. We demonstrated a cognition-enhancing potential in APPswe/PS1dE9 mice as their spatial memory function at 7M in the object location test was improved by prior GEBR-7b treatment. APPswe/PS1dE9 mice displayed lower levels of CREB phosphorylation, which remained unaltered after chronic GEBR-7b treatment, and higher levels of tau in the hippocampus. Hippocampal brain-derived neurotrophic factor levels and synaptic densities were not different between experimental groups and no effects were observed on hippocampal GSK3β and tau phosphorylation or Aβ levels. In conclusion, GEBR-7b can enhance spatial memory function in the APPswe/PS1dE9 mouse model of AD. Although the underlying mechanisms of its cognition-enhancing potential remain to be elucidated, PDE4D inhibition appears an interesting novel therapeutic option for cognitive deficits in AD. Copyright © 2013 Elsevier Ltd. All rights reserved.

Inhibition of Chlorine-Induced Lung Injury by the Type 4 Phosphodiesterase Inhibitor Rolipram

PubMed Central

Chang, Weiyuan; Chen, Jing; Schlueter, Connie F.; Rando, Roy J.; Pathak, Yashwant V.; Hoyle, Gary W.

2012-01-01

Chlorine is a highly toxic respiratory irritant that when inhaled causes epithelial cell injury, alveolar-capillary barrier disruption, airway hyperreactivity, inflammation, and pulmonary edema. Chlorine is considered a chemical threat agent, and its release through accidental or intentional means has the potential to result in mass casualties from acute lung injury. The type 4 phosphodiesterase inhibitor rolipram was investigated as a rescue treatment for chlorine-induced lung injury. Rolipram inhibits degradation of the intracellular signaling molecule cyclic AMP. Potential beneficial effects of increased cyclic AMP levels include inhibition of pulmonary edema, inflammation, and airway hyperreactivity. Mice were exposed to chlorine (whole body exposure, 228–270 ppm for 1 h) and were treated with rolipram by intraperitoneal, intranasal, or intramuscular (either aqueous or nanoemulsion formulation) delivery starting 1 h after exposure. Rolipram administered intraperitoneally or intranasally inhibited chlorine-induced pulmonary edema. Minor or no effects were observed on lavage fluid IgM (indicative of plasma protein leakage), KC (Cxcl1, neutrophil chemoattractant), and neutrophils. All routes of administration inhibited chlorine-induced airway hyperreactivity assessed 1 day after exposure. The results of the study suggest that rolipram may be an effective rescue treatment for chlorine-induced lung injury and that both systemic and targeted administration to the respiratory tract were effective routes of delivery. PMID:22763362

The regulation of transient receptor potential canonical 4 (TRPC4) channel by phosphodiesterase 5 inhibitor via the cyclic guanosine 3'5'-monophosphate.

PubMed

Wie, Jinhong; Jeong, SeungJoo; Kwak, Misun; Myeong, Jongyun; Chae, MeeRee; Park, Jong Kwan; Lee, Sung Won; So, Insuk

2017-06-01

The transient receptor potential (TRP) protein superfamily consists of a diverse group of cation channels that bear structural similarities to the fruit fly Drosophila TRP. The TRP superfamily is distinct from other groups of ion channels in displaying a large diversity in ion selectivity, modes of activation, and physiological functions. Classical TRP (transient receptor potential canonical (TRPC)) channels are activated by stimulation of Gq-PLC-coupled receptors and modulated by phosphorylation. The cyclic guanosine monophosphate (cGMP)-PKG pathway is involved in the regulation of TRPC3 and TRPC6 channels. Phosphodiesterase (PDE) 5 inhibitor induced muscle relaxation in corporal smooth muscle cells and was used to treat erectile dysfunction by inhibiting cGMP degradation. Here, we report the functional relationship between TRPC4 and cGMP. In human embryonic kidney (HEK) 293 cells overexpressing TRPC4, cGMP selectively activated TRPC4 channels and increased cytosolic calcium level through TRPC4 channel. We investigated phosphorylation sites in TRPC4 channels and identified S688 as an important phosphorylation site for the cGMP-PKG pathway. Cyclic GMP also activated TRPC4-like current with doubly rectifying current-voltage relationship in prostate smooth muscle cell lines. Taken together, these results show that TRPC4 is phosphorylated by the cGMP-PKG pathway and might be an important target for modulating prostate function by PDE5 inhibitors.

Omega-3 polyunsaturated fatty acids promote amyloid-β clearance from the brain through mediating the function of the glymphatic system.

PubMed

Ren, Huixia; Luo, Chuanming; Feng, Yanqing; Yao, Xiaoli; Shi, Zhe; Liang, Fengyin; Kang, Jing X; Wan, Jian-Bo; Pei, Zhong; Su, Huanxing

2017-01-01

Impairment of amyloid-β (Aβ) clearance leads to Aβ accumulation in the brain during the development of Alzheimer's disease (AD). Strategies that can restore or improve the clearance function hold great promise in delaying or preventing the onset of AD. Here, we show that n-3 polyunsaturated fatty acids (PUFAs), by use of fat-1 transgenic mice and oral administration of fish oil, significantly promote interstitial Aβ clearance from the brain and resist Aβ injury. Such beneficial effects were abolished in Aqp4-knockout mice, suggesting that the AQP4-dependent glymphatic system is actively involved in the promoting the effects of n-3 PUFAs on the clearance of extracellular Aβ. Imaging on clarified brain tissues clearly displayed that n-3 PUFAs markedly inhibit the activation of astrocytes and protect the AQP4 polarization in the affected brain region after Aβ injection. The results of the present study prove a novel mechanism by which n-3 PUFAs exert protective roles in reducing Aβ accumulation via mediating the glymphatic system function.-Ren, H., Luo, C., Feng, Y., Yao, X., Shi, Z., Liang, F., Kang, J. X., Wan, J.-B., Pei, Z., Su, H. Omega-3 polyunsaturated fatty acids promote amyloid-β clearance from the brain through mediating the function of the glymphatic system. © FASEB.

Annexin A7 Levels Increase in Rats With Traumatic Brain Injury and Promote Secondary Brain Injury.

PubMed

Gao, Fan; Li, Di; Rui, Qin; Ni, Haibo; Liu, Huixiang; Jiang, Feng; Tao, Li; Gao, Rong; Dang, Baoqi

2018-01-01

The incidence of traumatic brain injury (TBI) has been increasing annually. Annexin A7 is a calcium-dependent phospholipid binding protein. It can promote melting of the cell membrane. Recent studies have shown that it plays an important role in atherosclerosis, other cardiovascular diseases, and a variety of tumors. However, few studies of ANXA7 in TBI have been performed. We here observed how ANXA7 changes after TBI and discuss whether brain injury is associated with the use of ANXA7 antagonist intervention. Experimental Results: 1. After TBI, ANXA7 levels were higher than in the sham group, peaking 24 h after TBI. 2. The use of siA7 was found to reduce the expression of A7 in the injured brain tissue, and also brain edema, BBB damage, cell death, and apoptosis relative to the sham group. Conclusion: ANXA7 promotes the development of secondary brain injury (SBI) after TBI.

Discovery of novel pyrazolopyrimidinone analogs as potent inhibitors of phosphodiesterase type-5.

PubMed

Sawant, Sanghapal D; Lakshma Reddy, G; Dar, Mohd Ishaq; Srinivas, M; Gupta, Gourav; Sahu, Promod Kumar; Mahajan, Priya; Nargotra, Amit; Singh, Surjeet; Sharma, Subhash C; Tikoo, Manoj; Singh, Gurdarshan; Vishwakarma, Ram A; Syed, Sajad Hussain

2015-05-01

Cyclic guanosine monophosphate (cGMP) specific phosphodiesterase type-5 (PDE5), a clinically proven target to treat erectile dysfunction and diseases associated with lower cGMP levels in humans, is present in corpus cavernosum, heart, lung, platelets, prostate, urethra, bladder, liver, brain, and stomach. Sildenafil, vardenafil, tadalafil and avanafil are FDA approved drugs in market as PDE5 inhibitors for treating erectile dysfunction. In the present study a lead molecule 4-ethoxy-N-(6-hydroxyhexyl)-3-(1-methyl-7-oxo-3-propyl-6,7-dihydro-1H-pyrazolo[4,3-d]pyrimidin-5-yl)benzenesulfonamide, that is, compound-4a, an analog of pyrazolopyrimidinone scaffold has been identified as selective PDE5 inhibitor. A series of compounds was synthesized by replacing N-methylpiperazine moiety (ring-C) of sildenafil structure with different N-substitutions towards sulfonamide end. Compound-4a showed lower IC₅₀ value (1.5 nM) against PDE5 than parent sildenafil (5.6 nM) in in vitro enzyme assay. The isoform selectivity of the compound-4a against other PDE isoforms was similar to that of the Sildenafil. In corroboration with the in vitro data, this molecule showed better efficacy in in vivo studies using the conscious rabbit model. Also compound-4a exhibited good physicochemical properties like solubility, caco-2 permeability, cLogP along with optimal PK profile having no significant CYP enzyme inhibitory liabilities. Discovery of these novel bioactive compounds may open a new alternative for developing novel preclinical candidates based on this drugable scaffold. Copyright © 2015 Elsevier Ltd. All rights reserved.

The effect of phosphodiesterase inhibitors on the extinction of cocaine-induced conditioned place preference in mice.

PubMed

Liddie, Shervin; Anderson, Karen L; Paz, Andres; Itzhak, Yossef

2012-10-01

Several phosphodiesterase inhibitors (PDEis) improve cognition, suggesting that an increase in brain cAMP and cGMP facilitates learning and memory. Since extinction of drug-seeking behavior requires associative learning, consolidation and formation of new memory, the present study investigated the efficacy of three different PDEis in the extinction of cocaine-induced conditioned place preference (CPP) in B6129S mice. Mice were conditioned by escalating doses of cocaine which was resistant to extinction by free exploration. Immediately following each extinction session mice received (a) saline/vehicle, (b) rolipram (PDE4 inhibitor), (c) BAY-73-6691 (PDE9 inhibitor) or (d) papaverine (PDE10A inhibitor). Mice that received saline/vehicle during extinction training showed no reduction in CPP for >10 days. BAY-73-6691 (a) dose-dependently increased cGMP in hippocampus and amygdala, (b) significantly facilitated extinction and (c) diminished the reinstatement of cocaine CPP. Rolipram, which selectively increased brain cAMP levels, and papaverine which caused increases in both cAMP and cGMP levels, had no significant effect on the extinction of cocaine CPP. The results suggest that increase in hippocampal and amygdalar cGMP levels via blockade of PDE9 has a prominent role in the consolidation of extinction learning.

Impairment of Glymphatic Pathway Function Promotes Tau Pathology after Traumatic Brain Injury

PubMed Central

Chen, Michael J.; Plog, Benjamin A.; Zeppenfeld, Douglas M.; Soltero, Melissa; Yang, Lijun; Singh, Itender; Deane, Rashid; Nedergaard, Maiken

2014-01-01

Traumatic brain injury (TBI) is an established risk factor for the early development of dementia, including Alzheimer's disease, and the post-traumatic brain frequently exhibits neurofibrillary tangles comprised of aggregates of the protein tau. We have recently defined a brain-wide network of paravascular channels, termed the “glymphatic” pathway, along which CSF moves into and through the brain parenchyma, facilitating the clearance of interstitial solutes, including amyloid-β, from the brain. Here we demonstrate in mice that extracellular tau is cleared from the brain along these paravascular pathways. After TBI, glymphatic pathway function was reduced by ∼60%, with this impairment persisting for at least 1 month post injury. Genetic knock-out of the gene encoding the astroglial water channel aquaporin-4, which is importantly involved in paravascular interstitial solute clearance, exacerbated glymphatic pathway dysfunction after TBI and promoted the development of neurofibrillary pathology and neurodegeneration in the post-traumatic brain. These findings suggest that chronic impairment of glymphatic pathway function after TBI may be a key factor that renders the post-traumatic brain vulnerable to tau aggregation and the onset of neurodegeneration. PMID:25471560

A short review on structure and role of cyclic-3',5'-adenosine monophosphate-specific phosphodiesterase 4 as a treatment tool.

PubMed

Eskandari, Nahid; Mirmosayyeb, Omid; Bordbari, Gazaleh; Bastan, Reza; Yousefi, Zahra; Andalib, Alireza

2015-01-01

Cyclic nucleotide phosphodiesterases (PDEs) are known as a super-family of enzymes which catalyze the metabolism of the intracellular cyclic nucleotides, cyclic-3',5'-adenosine monophosphate (cAMP), and cyclic-3',5'-guanosine monophosphate that are expressed in a variety of cell types that can exert various functions based on their cells distribution. The PDE4 family has been the focus of vast research efforts over recent years because this family is considered as a prime target for therapeutic intervention in a number of inflammatory diseases such as asthma, chronic obstructive pulmonary disease, and rheumatoid arthritis, and it should be used and researched by pharmacists. This is because the major isoform of PDE that regulates inflammatory cell activity is the cAMP-specific PDE, PDE4. This review discusses the relationship between PDE4 and its inhibitor drugs based on structures, cells distribution, and pharmacological properties of PDE4 which can be informative for all pharmacy specialists.

Preclinical Characterization of the Phosphodiesterase 10A PET Tracer [(11)C]MK-8193.

PubMed

Hostetler, Eric D; Fan, Hong; Joshi, Aniket D; Zeng, Zhizhen; Eng, Waisi; Gantert, Liza; Holahan, Marie; Meng, Xianjun; Miller, Patricia; O'Malley, Stacey; Purcell, Mona; Riffel, Kerry; Salinas, Cristian; Williams, Mangay; Ma, Bennett; Buist, Nicole; Smith, Sean M; Coleman, Paul J; Cox, Christopher D; Flores, Brock A; Raheem, Izzat T; Cook, Jacquelynn J; Evelhoch, Jeffrey L

2016-08-01

A positron emission tomography (PET) tracer for the enzyme phosphodiesterase 10A (PDE10A) is desirable to guide the discovery and development of PDE10A inhibitors as potential therapeutics. The preclinical characterization of the PDE10A PET tracer [(11)C]MK-8193 is described. In vitro binding studies with [(3)H]MK-8193 were conducted in rat, monkey, and human brain tissue. PET studies with [(11)C]MK-8193 were conducted in rats and rhesus monkeys at baseline and following administration of a PDE10A inhibitor. [(3)H]MK-8193 is a high-affinity, selective PDE10A radioligand in rat, monkey, and human brain tissue. In vivo, [(11)C]MK-8193 displays rapid kinetics, low test-retest variability, and a large specific signal that is displaced by a structurally diverse PDE10A inhibitor, enabling the determination of pharmacokinetic/enzyme occupancy relationships. [(11)C]MK-8193 is a useful PET tracer for the preclinical characterization of PDE10A therapeutic candidates in rat and monkey. Further evaluation of [(11)C]MK-8193 in humans is warranted.

Phosphodiesterase 9A regulates central cGMP and modulates responses to cholinergic and monoaminergic perturbation in vivo.

PubMed

Kleiman, Robin J; Chapin, Douglas S; Christoffersen, Curt; Freeman, Jody; Fonseca, Kari R; Geoghegan, Kieran F; Grimwood, Sarah; Guanowsky, Victor; Hajós, Mihály; Harms, John F; Helal, Christopher J; Hoffmann, William E; Kocan, Geralyn P; Majchrzak, Mark J; McGinnis, Dina; McLean, Stafford; Menniti, Frank S; Nelson, Fredrick; Roof, Robin; Schmidt, Anne W; Seymour, Patricia A; Stephenson, Diane T; Tingley, Francis David; Vanase-Frawley, Michelle; Verhoest, Patrick R; Schmidt, Christopher J

2012-05-01

Cyclic nucleotides are critical regulators of synaptic plasticity and participate in requisite signaling cascades implicated across multiple neurotransmitter systems. Phosphodiesterase 9A (PDE9A) is a high-affinity, cGMP-specific enzyme widely expressed in the rodent central nervous system. In the current study, we observed neuronal staining with antibodies raised against PDE9A protein in human cortex, cerebellum, and subiculum. We have also developed several potent, selective, and brain-penetrant PDE9A inhibitors and used them to probe the function of PDE9A in vivo. Administration of these compounds to animals led to dose-dependent accumulation of cGMP in brain tissue and cerebrospinal fluid, producing a range of biological effects that implied functional significance for PDE9A-regulated cGMP in dopaminergic, cholinergic, and serotonergic neurotransmission and were consistent with the widespread distribution of PDE9A. In vivo effects of PDE9A inhibition included reversal of the respective disruptions of working memory by ketamine, episodic and spatial memory by scopolamine, and auditory gating by amphetamine, as well as potentiation of risperidone-induced improvements in sensorimotor gating and reversal of the stereotypic scratching response to the hallucinogenic 5-hydroxytryptamine 2A agonist mescaline. The results suggested a role for PDE9A in the regulation of monoaminergic circuitry associated with sensory processing and memory. Thus, PDE9A activity regulates neuronal cGMP signaling downstream of multiple neurotransmitter systems, and inhibition of PDE9A may provide therapeutic benefits in psychiatric and neurodegenerative diseases promoted by the dysfunction of these diverse neurotransmitter systems.

[Phosphodiesterase-5 inhibitors for the treatment of pulmonary arterial hypertension].

PubMed

Beltrán-Gámez, Miguel E; Sandoval-Zárate, Julio; Pulido, Tomás

2015-01-01

In experimental and clinical cardiology, phosphodiesterase type 5 (PDE-5) inhibitors have brought scientific interest as a therapeutic tool in pulmonary arterial hypertension (PAH) management in recent years. Phosphodiesterases are a superfamily of enzymes that inactivate cyclic adenosine monophosphate and cyclic guanosine monophosphate, the second messengers of prostacyclin and nitric oxide. The rationale for the use of PDE-5 inhibitors in PAH is based on their capacity to overexpresss the nitric oxide pathway pursued inhibition of cyclic guanosine monophosphate hydrolysis. By increasing cyclic guanosine monophosphate levels it promotes vasodilation, antiproliferative and pro-apoptotic effects that may reverse pulmonary vascular remodeling. There is also evidence that these drugs may directly enhance right ventricular contractility through an increase in cyclic adenosine monophosphate mediated by the inhibition of the cyclic guanosine monophosphate -sensitive PDE-3. Sildenafil, tadalafil and vardenafil are 3 specific PDE-5 inhibitors in current clinical use, which share similar mechanisms of action but present some significant differences regarding potency, selectivity for PDE-5 and pharmacokinetic properties. Sildenafil received approval in 2005 by the Food and Drug Administration and the European Medicines Agency and tadalafil in 2009 by the Food and Drug Administration and the European Medicines Agency for the treatment of PAH in patients classified as NYHA/WHO functional class II and III. In Mexico, sildenafil and tadalafil were approved by Comisión Federal de Protección contra Riesgos Sanitarios for this indication in 2010 and 2011, respectively. Copyright © 2014 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

Inhibition of chlorine-induced lung injury by the type 4 phosphodiesterase inhibitor rolipram.

PubMed

Chang, Weiyuan; Chen, Jing; Schlueter, Connie F; Rando, Roy J; Pathak, Yashwant V; Hoyle, Gary W

2012-09-01

Chlorine is a highly toxic respiratory irritant that when inhaled causes epithelial cell injury, alveolar-capillary barrier disruption, airway hyperreactivity, inflammation, and pulmonary edema. Chlorine is considered a chemical threat agent, and its release through accidental or intentional means has the potential to result in mass casualties from acute lung injury. The type 4 phosphodiesterase inhibitor rolipram was investigated as a rescue treatment for chlorine-induced lung injury. Rolipram inhibits degradation of the intracellular signaling molecule cyclic AMP. Potential beneficial effects of increased cyclic AMP levels include inhibition of pulmonary edema, inflammation, and airway hyperreactivity. Mice were exposed to chlorine (whole body exposure, 228-270 ppm for 1 h) and were treated with rolipram by intraperitoneal, intranasal, or intramuscular (either aqueous or nanoemulsion formulation) delivery starting 1h after exposure. Rolipram administered intraperitoneally or intranasally inhibited chlorine-induced pulmonary edema. Minor or no effects were observed on lavage fluid IgM (indicative of plasma protein leakage), KC (Cxcl1, neutrophil chemoattractant), and neutrophils. All routes of administration inhibited chlorine-induced airway hyperreactivity assessed 1 day after exposure. The results of the study suggest that rolipram may be an effective rescue treatment for chlorine-induced lung injury and that both systemic and targeted administration to the respiratory tract were effective routes of delivery. Copyright © 2012 Elsevier Inc. All rights reserved.

Phosphodiesterase 4 inhibitors for chronic obstructive pulmonary disease.

PubMed

Chong, Jimmy; Leung, Bonnie; Poole, Phillippa

2017-09-19

Chronic obstructive pulmonary disease (COPD) is associated with cough, sputum production or dyspnoea and a reduction in lung function, quality of life and life expectancy. Apart from smoking cessation, there are no other treatments that slow lung function decline. Roflumilast and cilomilast are oral phosphodiesterase 4 (PDE 4 ) inhibitors proposed to reduce the airway inflammation and bronchoconstriction seen in COPD. This is an update of a Cochrane review first published in 2011 and updated in 2013. To evaluate the efficacy and safety of oral PDE 4 inhibitors in the management of stable COPD. We identified randomised controlled trials (RCTs) from the Cochrane Airways Trials Register (date of last search October 2016). We found other trials from web-based clinical trials registers. We included RCTs if they compared oral PDE 4 inhibitors with placebo in people with COPD. We allowed co-administration of standard COPD therapy. One review author extracted data and a second review author checked the data. We reported pooled data in Review Manager as mean differences (MD), standardised mean differences (SMD) or odds ratios (OR). We converted the odds ratios into absolute treatment effects in a 'Summary of findings' table. Thirty-four separate RCTs studying roflumilast (20 trials with 17,627 participants) or cilomilast (14 trials with 6457 participants) met the inclusion criteria, with a duration of between six weeks and one year. These included people across international study centres with moderate to very severe COPD (Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades II-IV), with a mean age of 64 years.We considered that the methodological quality of the 34 published and unpublished trials was acceptable overall. Treatment with a PDE 4 inhibitor was associated with a significant improvement in forced expiratory volume in one second (FEV 1 ) over the trial period compared with placebo (MD 51.53 mL, 95% confidence interval (CI) 43.17 to 59.90, 27

The phosphodiesterase-4 inhibitor roflumilast decreases ethanol consumption in C57BL/6J mice.

PubMed

Liu, Xin; Hao, Pi-Da; Yang, Ming-Feng; Sun, Jing-Yi; Mao, Lei-Lei; Fan, Cun-Dong; Zhang, Zong-Yong; Li, Da-Wei; Yang, Xiao-Yi; Sun, Bao-Liang; Zhang, Han-Ting

2017-08-01

Alcohol use disorders have become one of the most damaging psychiatric disorders in the world; however, there are no ideal treatments in clinic. Phosphodiesterase-4 (PDE4), an enzyme that specifically hydrolyzes intracellular cyclic AMP (cAMP), has been involved in alcohol use disorders. Roflumilast is the first PDE4 inhibitor approved for treatment of chronic obstructive pulmonary diseases in clinic. It was of particular interest to researchers to determine whether roflumilast altered ethanol consumption. The present study tried to determine the effects of roflumilast on ethanol intake and preference. We used the two-bottle choice paradigm to assess ethanol intake and preference in C57BL/6J mice treated with roflumilast (1, 3, or 10 mg/kg) or rolipram (0.5 mg/kg; positive control). The effect of roflumilast was verified using the ethanol drinking-in-dark (DID) test. Locomotor activity was examined using the open-field test. Intake of sucrose or quinine was also tested to determine whether natural reward preference and aversive stimuli were involved in the effect of PDE4 inhibitors. Similar to rolipram, roflumilast decreased ethanol intake and preference in two-bottle choice and DID tests in a dose-dependent manner, with significant changes at the dose of 10 mg/kg; in contrast, roflumilast did not affect sucrose or quinine drinking, although it decreased locomotor activity at the high dose within 3 h of treatment. These data provide novel demonstration for the effect of roflumilast on ethanol consumption and suggest that roflumilast may be beneficial for treatment of alcoholism.

Carcinoma-astrocyte gap junctions promote brain metastasis by cGAMP transfer.

PubMed

Chen, Qing; Boire, Adrienne; Jin, Xin; Valiente, Manuel; Er, Ekrem Emrah; Lopez-Soto, Alejandro; Jacob, Leni; Patwa, Ruzeen; Shah, Hardik; Xu, Ke; Cross, Justin R; Massagué, Joan

2016-05-26

Brain metastasis represents a substantial source of morbidity and mortality in various cancers, and is characterized by high resistance to chemotherapy. Here we define the role of the most abundant cell type in the brain, the astrocyte, in promoting brain metastasis. We show that human and mouse breast and lung cancer cells express protocadherin 7 (PCDH7), which promotes the assembly of carcinoma-astrocyte gap junctions composed of connexin 43 (Cx43). Once engaged with the astrocyte gap-junctional network, brain metastatic cancer cells use these channels to transfer the second messenger cGAMP to astrocytes, activating the STING pathway and production of inflammatory cytokines such as interferon-α (IFNα) and tumour necrosis factor (TNF). As paracrine signals, these factors activate the STAT1 and NF-κB pathways in brain metastatic cells, thereby supporting tumour growth and chemoresistance. The orally bioavailable modulators of gap junctions meclofenamate and tonabersat break this paracrine loop, and we provide proof-of-principle that these drugs could be used to treat established brain metastasis.

A phosphodiesterase 4B-dependent interplay between tumor cells and the microenvironment regulates angiogenesis in B-cell lymphoma

PubMed Central

Suhasini, Avvaru N.; Lin, An-Ping; Bhatnagar, Harshita; Kim, Sang-Woo; Moritz, August W.; Aguiar, Ricardo C. T.

2015-01-01

Angiogenesis associates with poor outcome in diffuse large B-cell lymphoma (DLBCL), but the contribution of the lymphoma cells to this process remains unclear. Addressing this knowledge gap may uncover unsuspecting proangiogenic signaling nodes and highlight alternative antiangiogenic therapies. Here we identify the second messenger cyclic-AMP (cAMP) and the enzyme that terminates its activity, phosphodiesterase 4B (PDE4B), as regulators of B-cell lymphoma angiogenesis. We first show that cAMP, in a PDE4B-dependent manner, suppresses PI3K/AKT signals to down-modulate VEGF secretion and vessel formation in vitro. Next, we create a novel mouse model that combines the lymphomagenic Myc transgene with germline deletion of Pde4b. We show that lymphomas developing in a Pde4b-null background display significantly lower microvessel density in association with lower VEGF levels and PI3K/AKT activity. We recapitulate these observations by treating lymphoma-bearing mice with the FDA-approved PDE4 inhibitor Roflumilast. Lastly, we show that primary human DLBCLs with high PDE4B expression display significantly higher microvessel density. Here, we defined an unsuspected signaling circuitry in which the cAMP generated in lymphoma cells downmodulates PI3K/AKT and VEGF secretion to negatively influence vessel development in the microenvironment. These data identify PDE4 as an actionable antiangiogenic target in DLBCL. PMID:26503641

Inhibition of phosphodiesterase 4 reduces ethanol intake and preference in C57BL/6J mice

PubMed Central

Blednov, Yuri A.; Benavidez, Jillian M.; Black, Mendy; Harris, R. Adron

2014-01-01

Some anti-inflammatory medications reduce alcohol consumption in rodent models. Inhibition of phosphodiesterases (PDE) increases cAMP and reduces inflammatory signaling. Rolipram, an inhibitor of PDE4, markedly reduced ethanol intake and preference in mice and reduced ethanol seeking and consumption in alcohol-preferring fawn-hooded rats (Hu et al., 2011; Wen et al., 2012). To determine if these effects were specific for PDE4, we compared nine PDE inhibitors with different subtype selectivity: propentofylline (nonspecific), vinpocetine (PDE1), olprinone, milrinone (PDE3), zaprinast (PDE5), rolipram, mesopram, piclamilast, and CDP840 (PDE4). Alcohol intake was measured in C57BL/6J male mice using 24-h two-bottle choice and two-bottle choice with limited (3-h) access to alcohol. Only the selective PDE4 inhibitors reduced ethanol intake and preference in the 24-h two-bottle choice test. For rolipram, piclamilast, and CDP840, this effect was observed after the first 6 h but not after the next 18 h. Mesopram, however, produced a long-lasting reduction of ethanol intake and preference. In the limited access test, rolipram, piclamilast, and mesopram reduced ethanol consumption and total fluid intake and did not change preference for ethanol, whereas CDP840 reduced both consumption and preference without altering total fluid intake. Our results provide novel evidence for a selective role of PDE4 in regulating ethanol drinking in mice. We suggest that inhibition of PDE4 may be an unexplored target for medication development to reduce excessive alcohol consumption. PMID:24904269

Crisaborole: Phosphodiesterase inhibitor for treatment of atopic dermatitis.

PubMed

Paton, D M

2017-04-01

Atopic dermatitis (AD) is an extremely common condition affecting as many as 10-20% of children and 2-10% of adults. A particularly distressing symptom of AD is pruritus. One of the important aspects of AD is inflammation associated with increased activity of phosphodiesterase 4 (PDE4), resulting in decreased intracellular levels of cyclic adenosine monophosphate, which in turn causes increased production of inflammatory cytokines. Crisaborole was developed as a small-molecule, boron-based, selective PDE4 inhibitor that can be used topically. Clinical trials have demonstrated its efficacy in treating patients with mild to moderate AD, resulting in significant relief of pruritus. Unlike PDE4 inhibitors that act systemically, crisaborole does not cause significant gastrointestinal adverse effects. The most common adverse effect has been temporary stinging and burning in about 4% of patients upon application of the 2% ointment. To date there is no evidence of atrophy, telangiectasia or hypopigmentation resulting from its use. Crisaborole is the first topically applied PDE4 inhibitor to be approved by the FDA for use in AD. Copyright 2017 Clarivate Analytics.

The in vivo pharmacology of CP-80, 633, a selective inhibitor of phosphodiesterase 4.

PubMed

Turner, C R; Cohan, V L; Cheng, J B; Showell, H J; Pazoles, C J; Watson, J W

1996-09-01

The following studies were conducted to characterize the bron-chodilatory and antiinflammatory activity of the novel, selective phosphodiesterase-IV inhibitor, CP-80,633 (2'S)5-[3-(2'-exobicyclo[2.2.1]heptyloxy-4-methoxy-phenyl]te trahydro- 2(1H)-pyrimidone, a compound in clinical development for atopic disease. In IgG1 passively sensitized guinea pigs, aerosolized ovalbumin challenge increases both pulmonary eosinophil peroxidase levels and airway obstruction. CP-80,633, administered before ovalbumin challenge, significantly attenuated both the increase in tissue eosinophil peroxidase levels (ED50 = 1.4 mg/kg, p.o.) and airway obstruction (ED50 = 0.93 +/- 0.14 mg/kg,p.o.) 10 to 30 times more potently than theophyl-line. Intraarterially administered CP-80,633 also reversed an established bronchoconstriction initiated by continuous infusion of histamine to guinea pigs (ED50 of 8.2 micrograms/kg vs. 5.6 mg/kg for theophylline). The antiinflammatory effect of CP-80,633 was also examined in atopic monkeys challenged with Ascaris suum (Ag) aerosol. CP-80,633 (1 mg/kg, qid, s.c., 1 hr before antigen challenge) significantly reduced antigen-induced increases in bronchoalveolar lavage neutrophils (72.8 +/- 15.8% inhibition) and eosinophils (61.1 +/- 5.7% inhibition) 4 hr postchallenge, but did not reduce leukocytes 24 hr postchallenge. CP-80,633 did not inhibit antigen-induced increases in BAL levels of interleukin-1 beta, -6 or -8 as measured by enzyme-linked immunosorbant assay. These results indicate that CP-80,633 possesses bronchodilatory activity in guinea pigs and some antiinflammatory effects in both guinea pigs and monkeys.

Prenylated flavonoids as potent phosphodiesterase-4 inhibitors from Morus alba: Isolation, modification, and structure-activity relationship study.

PubMed

Guo, Yan-Qiong; Tang, Gui-Hua; Lou, Lan-Lan; Li, Wei; Zhang, Bei; Liu, Bo; Yin, Sheng

2018-01-20

The bioassay-guided phytochemical study of a traditional Chinese medicine Morus alba led to the isolation of 18 prenylated flavonoids (1-18), of which (±)-cyclomorusin (1/2), a pair of enantiomers, and 14-methoxy-dihydromorusin (3) are the new ones. Subsequent structural modification of the selected components by methylation, esterification, hydrogenation, and oxidative cyclization led to 14 more derivatives (19-32). The small library was screened for its inhibition against phosphodiesterase-4 (PDE4), which is a drug target for the treatment of asthma and chronic obstructive pulmonary disease (COPD). Among them, nine compounds (1-5, 8, 10, 16, and 17) exhibited remarkable activities with IC 50 values ranging from 0.0054 to 0.40 μM, being more active than the positive control rolipram (IC 50  = 0.62 μM). (+)-Cyclomorusin (1), the most active natural PDE4 inhibitor reported so far, also showed a high selectivity across other PDE members with the selective fold greater than 55. The SAR study revealed that the presence of prenyls at C-3 and/or C-8, 2H-pyran ring D, and the phenolic hydroxyl groups were important to the activity, which was further supported by the recognition mechanism study of the inhibitors with PDE4 by using molecular modeling. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Distinct phosphodiesterase 5A-containing compartments allow selective regulation of cGMP-dependent signalling in human arterial smooth muscle cells.

PubMed

Wilson, Lindsay S; Guo, Manhong; Umana, M Bibiana; Maurice, Donald H

2017-08-01

Cyclic GMP (cGMP) translates and integrates much of the information encoded by nitric oxide (NO · ) and several natriuretic peptides, including the atrial natriuretic peptide (ANP). Previously, we reported that integration of a cGMP-specific cyclic nucleotide phosphodiesterase, namely phosphodiesterase 5A (PDE5A), into a protein kinase G (PKG)- and inositol-1,4,5-trisphosphate receptor (IP 3 R)-containing endoplasmic reticulum (ER) signalosome allows localized control of PDE5A activity and of PKG-dependent inhibition of IP 3 -mediated release of ER Ca 2+ in human platelets. Herein, we report that PDE5A integrates into an analogous signalosome in human arterial smooth muscle cells (HASMC), wherein it regulates muscarinic agonist-dependent Ca 2+ release and is activated selectively by PKG-dependent phosphorylation. In addition, we report that PDE5A also regulates HASMC functions via events independent of PKG, but rather through actions coordinated by competitive cGMP-mediated inhibition of cAMP hydrolysis by the so-called cGMP-inhibited cAMP PDE, namely phosphodiesterase 3A (PDE3A). Indeed, we show that ANP increases both cGMP and cAMP levels in HASMC and promotes phosphorylation of vasodilator-stimulated phospho-protein (VASP) at each the PKG and PKA phospho-acceptor sites. Since selective inhibition of PDE5 decreased DNA synthesis and chemotaxis of HASMC, and that PDE3A knockdown obviated these effects, our findings are consistent with a role for a PDE5A-PDE3A-PKA axis in their regulation. Our findings provide insight into the existence of distinct "pools" of PDE5A in HASMC and support the idea that these discrete compartments regulate distinct cGMP-dependent events. As a corollary, we suggest that it may be possible to target these distinct PDE5A-regulated pools and in so-doing differentially impact selected cGMP-regulated functions in these cells. Copyright © 2017. Published by Elsevier Inc.

A small-molecule antagonist of CXCR4 inhibits intracranial growth of primary brain tumors

NASA Astrophysics Data System (ADS)

Rubin, Joshua B.; Kung, Andrew L.; Klein, Robyn S.; Chan, Jennifer A.; Sun, Yanping; Schmidt, Karl; Kieran, Mark W.; Luster, Andrew D.; Segal, Rosalind A.

2003-11-01

The vast majority of brain tumors in adults exhibit glial characteristics. Brain tumors in children are diverse: Many have neuronal characteristics, whereas others have glial features. Here we show that activation of the Gi protein-coupled receptor CXCR4 is critical for the growth of both malignant neuronal and glial tumors. Systemic administration of CXCR4 antagonist AMD 3100 inhibits growth of intracranial glioblastoma and medulloblastoma xenografts by increasing apoptosis and decreasing the proliferation of tumor cells. This reflects the ability of AMD 3100 to reduce the activation of extracellular signal-regulated kinases 1 and 2 and Akt, all of which are pathways downstream of CXCR4 that promote survival, proliferation, and migration. These studies (i) demonstrate that CXCR4 is critical to the progression of diverse brain malignances and (ii) provide a scientific rationale for clinical evaluation of AMD 3100 in treating both adults and children with malignant brain tumors.

2-Year animal carcinogenicity results for crisaborole, a novel phosphodiesterase 4 inhibitor for atopic dermatitis.

PubMed

Ciaravino, Vic; Coronado, Dina; Lanphear, Cheryl; Chanda, Sanjay

2017-08-01

Crisaborole is a novel, topical nonsteroidal, anti-inflammatory, phosphodiesterase 4 (PDE4) inhibitor for the treatment of mild to moderate atopic dermatitis. As part of a nonclinical safety testing program, these 2-year studies tested the carcinogenic potential of crisaborole. Crisaborole ointment, 2%, 5%, or 7%, was applied once daily topically to mice, and crisaborole was administered orally to rats at doses of 30, 100, or 300mg/kg/day for up to 104 weeks. Systemic exposure to crisaborole and its metabolites, moribundity/death, clinical signs, and tumor formation were assessed in each study. Crisaborole treatment was not tumorigenic in mice at any of the doses administered and did not increase the incidence of neoplastic or nonneoplastic microscopic lesions compared with controls. Oral administration of crisaborole at the high dose (300mg/kg/day) to female rats increased the incidence of treatment-related benign granular cell tumors in the distal reproductive tract (uterus with cervix and vagina) but did not cause moribundity/death. Crisaborole was well tolerated and not tumorigenic in mice. It was not tumorigenic in male rats at 300mg/kg/day at exposures that were 3× the human area under the concentration-time curve (AUC 24 ) and was nontumorigenic in female rats at 100mg/kg/day at exposures that were 1× the human AUC 24 . Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Synergistic effect between 5-HT4 receptor agonist and phosphodiesterase 4-inhibitor in releasing acetylcholine in pig gastric circular muscle in vitro.

PubMed

Lefebvre, Romain A; Van Colen, Inge; Pauwelyn, Vicky; De Maeyer, Joris H

2016-06-15

5-HT4 receptor agonists have a gastroprokinetic effect by facilitating acetylcholine release from cholinergic nerves innervating gastrointestinal smooth muscle. The role of phosphodiesterase (PDE) 4 in the signal transduction pathway of the 5-HT4 receptors located on the cholinergic neurons towards the circular muscle layer in pig stomach was investigated by analysis of acetylcholine release. Circular muscle strips were prepared from pig proximal stomach and tritium outflow, induced by electrical field stimulation, was studied as a marker for acetylcholine release after incubation with [(3)H]-choline. The PDE4-inhibitor roflumilast concentration-dependently (0.1-1µM) enhanced the facilitating effect of a submaximally effective concentration of the 5-HT4 receptor agonist prucalopride (0.01µM) on electrically induced acetylcholine release. Roflumilast (0.3µM) enhanced acetylcholine release per se but in the combined presence of roflumilast and prucalopride, acetylcholine release was enhanced more than the sum of the effect of the 2 compounds alone. The 5-HT4 receptor agonist velusetrag concentration-dependently (0.01-0.1µM) enhanced acetylcholine release; the effect of the minimally effective concentration (0.01µM) was significantly enhanced by 1µM of the PDE4-inhibitor rolipram, again to a level higher than the sum of the effect of the 2 compounds alone. The synergistic effect between 5-HT4 receptor agonists and PDE4-inhibitors demonstrates that the intracellular pathway of the 5-HT4 receptors located on cholinergic neurons towards pig gastric circular muscle is controlled by PDE4. Combining a 5-HT4 receptor agonist with a PDE4-inhibitor might thus enhance its gastroprokinetic effect. Copyright © 2016 Elsevier B.V. All rights reserved.

Glucocorticoid receptor gene expression and promoter CpG modifications throughout the human brain.

PubMed

Cao-Lei, Lei; Suwansirikul, Songkiet; Jutavijittum, Prapan; Mériaux, Sophie B; Turner, Jonathan D; Muller, Claude P

2013-11-01

Glucocorticoids and the glucocorticoid (GR) and mineralocorticoid (MR) receptors have been implicated in many processes, particularly in negative feedback regulation of the hypothalamic-pituitary-adrenal axis. Epigenetically programmed GR alternative promoter usage underlies transcriptional control of GR levels, generation of GR 3' splice variants, and the overall GC response in the brain. No detailed analysis of GR first exons or GR transcript variants throughout the human brain has been reported. Therefore we investigated post mortem tissues from 28 brain regions of 5 individuals. GR first exons were expressed throughout the healthy human brain with no region-specific usage patterns. First exon levels were highly inter-correlated suggesting that they are co-regulated. GR 3' splice variants (GRα and GR-P) were equally distributed in all regions, and GRβ expression was always low. GR/MR ratios showed significant differences between the 28 tissues with the highest ratio in the pituitary gland. Modification levels of individual CpG dinucleotides, including 5-mC and 5-hmC, in promoters 1D, 1E, 1F, and 1H were low, and diffusely clustered; despite significant heterogeneity between the donors. In agreement with this clustering, sum modification levels rather than individual CpG modifications correlated with GR expression. Two-way ANOVA showed that this sum modification was both promoter and brain region specific, but that there was however no promoter*tissue interaction. The heterogeneity between donors may however hide such an interaction. In both promoters 1F and 1H modification levels correlated with GRα expression suggesting that 5-mC and 5-hmC play an important role in fine tuning GR expression levels throughout the brain. Copyright © 2013 Elsevier Ltd. All rights reserved.

Powerful relaxation of phosphodiesterase type 4 inhibitor rolipram in the pig and human bladder neck.

PubMed

Ribeiro, Ana S F; Fernandes, Vítor S; Martínez-Sáenz, Ana; Martínez, Pilar; Barahona, María Victoria; Orensanz, Luis M; Blaha, Igor; Serrano-Margüello, Daniel; Bustamante, Salvador; Carballido, Joaquín; García-Sacristán, Albino; Prieto, Dolores; Hernández, Medardo

2014-04-01

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. 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. 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. PDE4 expression and relaxations to PDE4 and PDE5 inhibitors and simultaneous measurements of [Ca2+]i and tension. 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 (H2 S) synthases reduced rolipram responses. Rolipram inhibited the contractions induced by PhE without reducing the PhE-evoked [Ca2+]i increase. 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

Identification, characterization and subcellular localization of TcPDE1, a novel cAMP-specific phosphodiesterase from Trypanosoma cruzi.

PubMed Central

D'Angelo, Maximiliano A; Sanguineti, Santiago; Reece, Jeffrey M; Birnbaumer, Lutz; Torres, Héctor N; Flawiá, Mirtha M

2004-01-01

Compartmentalization of cAMP phosphodiesterases plays a key role in the regulation of cAMP signalling in mammals. In the present paper, we report the characterization and subcellular localization of TcPDE1, the first cAMP-specific phosphodiesterase to be identified from Trypanosoma cruzi. TcPDE1 is part of a small gene family and encodes a 929-amino-acid protein that can complement a heat-shock-sensitive yeast mutant deficient in phospho-diesterase genes. Recombinant TcPDE1 strongly associates with membranes and cannot be released with NaCl or sodium cholate, suggesting that it is an integral membrane protein. This enzyme is specific for cAMP and its activity is not affected by cGMP, Ca2+, calmodulin or fenotiazinic inhibitors. TcPDE1 is sensitive to the phosphodiesterase inhibitor dipyridamole but is resistant to 3-isobutyl-1-methylxanthine, theophylline, rolipram and zaprinast. Papaverine, erythro-9-(2-hydroxy-3-nonyl)-adenine hydrochloride, and vinpocetine are poor inhibitors of this enzyme. Confocal laser scanning of T. cruzi epimastigotes showed that TcPDE1 is associated with the plasma membrane and concentrated in the flagellum of the parasite. The association of TcPDE1 with this organelle was confirmed by subcellular fractionation and cell-disruption treatments. The localization of this enzyme is a unique feature that distinguishes it from all the trypanosomatid phosphodiesterases described so far and indicates that compartmentalization of cAMP phosphodiesterases could also be important in these parasites. PMID:14556647

A mouse model of Rubinstein-Taybi syndrome: Defective long-term memory is ameliorated by inhibitors of phosphodiesterase 4

PubMed Central

Bourtchouladze, Rusiko; Lidge, Regina; Catapano, Ray; Stanley, Jennifer; Gossweiler, Scott; Romashko, Darlene; Scott, Rod; Tully, Tim

2003-01-01

Mice carrying a truncated form of cAMP-responsive element binding protein (CREB)-binding protein (CBP) show several developmental abnormalities similar to patients with Rubinstein-Taybi syndrome (RTS). RTS patients suffer from mental retardation, whereas long-term memory formation is defective in mutant CBP mice. A critical role for cAMP signaling during CREB-dependent long-term memory formation appears to be evolutionarily conserved. From this observation, we reasoned that drugs that modulate CREB function by enhancing cAMP signaling might yield an effective treatment for the memory defect(s) of CBP+/− mice. To this end, we designed a cell-based drug screen and discovered inhibitors of phosphodiesterase 4 (PDE4) to be particularly effective enhancers of CREB function. We extend previous behavioral observations by showing that CBP+/− mutants have impaired long-term memory but normal learning and short-term memory in an object recognition task. We demonstrate that the prototypical PDE4 inhibitor, rolipram, and a novel one (HT0712) abolish the long-term memory defect of CBP+/− mice. Importantly, the genetic lesion in CBP acts specifically to shift the dose sensitivity for HT0712 to enhance memory formation, which conveys molecular specificity on the drug's mechanism of action. Our results suggest that PDE4 inhibitors may be used to treat the cognitive dysfunction of RTS patients. PMID:12930888

RECEPTOR AFFINITY AND PHOSPHODIESTERASES 4B AND 10A ACTIVITY OF OCTAHYDRO- AND 6,7-DIMETHOXY-3,4-DIHYDRO- ISOQUINOLIN-2(1H)-YL-ALKYL DERIVATIVES OF IMIDAZO- AND PYRIMIDINO[2,1-f]PURINES.

PubMed

Zagórska, Agnieszka; Gryzło, Beata; Satała, Grzegorz; Bojarski, Andrzej J; Głuch-Lutwin, Monika; Mordyl, Barbara; Kazek, Grzegorz; Pawłowski, Maciej

2016-01-01

A series of octahydro- and 6,7-dimethoxy-3,4-dihydro- isoquinolin-2(1H)-yl-alkyl derivatives of imidazo- and pyrimidino[2,1-f]purines were synthesized and biologically evaluated in in vitro competition binding experiments for serotonin 5-HT(1A), 5-HT(6), 5-HT(7), and dopamine D2 receptors and inhibitory potencies for phosphodiesterases - PDE4B1 and PDE10A. The structure-activity relationships allowed to determine the structural features responsible for receptor and enzyme activity. Compound 5 (8-(4-(6,7-dimethoxy-3,4-dihydroiso- quinolin-2(1H)butyl)1,3-dimethyl-H-imidazo[2,1-f]purine-2,4(3H,8H)-dione) could be regarded as promising structure for further modification and detailed mechanistic study for obtained hybrid ligands.

Association between a variation in the phosphodiesterase 4D gene and bone mineral density.

PubMed

Reneland, Richard H; Mah, Steven; Kammerer, Stefan; Hoyal, Carolyn R; Marnellos, George; Wilson, Scott G; Sambrook, Philip N; Spector, Tim D; Nelson, Matthew R; Braun, Andreas

2005-03-07

Fragility fractures caused by osteoporosis are a major cause of morbidity and mortality in aging populations. Bone mineral density (BMD) is a useful surrogate marker for risk of fracture and is a highly heritable trait. The genetic variants underlying this genetic contribution are largely unknown. We performed a large-scale association study investigating more than 25,000 single nucleotide polymorphisms (SNPs) located within 16,000 genes. Allele frequencies were estimated in contrasting DNA pools from white females selected for low (<0.87 g/cm2, n = 319) and high (> 1.11 g/cm2, n = 321) BMD at the lumbar spine. Significant findings were verified in two additional sample collections. Based on allele frequency differences between DNA pools and subsequent individual genotyping, one of the candidate loci indicated was the phosphodiesterase 4D (PDE4D) gene region on chromosome 5q12. We subsequently tested the marker SNP, rs1498608, in a second sample of 138 white females with low (<0.91 g/cm2) and 138 females with high (>1.04 g/cm2) lumbar spine BMD. Odds ratios were 1.5 (P = 0.035) in the original sample and 2.1 (P = 0.018) in the replication sample. Association fine mapping with 80 SNPs located within 50 kilobases of the marker SNP identified a 20 kilobase region of association containing exon 6 of PDE4D. In a second, family-based replication sample with a preponderance of females with low BMD, rs1498608 showed an opposite relationship with BMD at different sites (p = 0.00044-0.09). We also replicated the previously reported association of the Ser37Ala polymorphism in BMP2, known to interact biologically with PDE4D, with BMD. This study indicates that variants in the gene encoding PDE4D account for some of the genetic contribution to bone mineral density variation in humans. The contrasting results from different samples indicate that the effect may be context-dependent. PDE4 inhibitors have been shown to increase bone mass in normal and osteopenic mice, but up until

Palmitoylation regulates intracellular trafficking of β2 adrenergic receptor/arrestin/phosphodiesterase 4D complexes in cardiomyocytes.

PubMed

Liu, Ruijie; Wang, Dayong; Shi, Qian; Fu, Qin; Hizon, Steven; Xiang, Yang K

2012-01-01

β(2) adrenergic receptor (β(2)AR) is a prototypical G-protein coupled receptor that stimulates the classic cAMP-protein kinase A (PKA) signaling pathway. Recent studies indicate that the cAMP-PKA activities are spatiotemporally regulated in part due to dynamic association of β(2)AR with phosphodiesterase 4D (PDE4D), a group of cAMP degradation enzymes. Here, we demonstrate that in cardiomyocytes, palmitoylation of β(2)AR, the covalent acylation of cysteine residue 341, plays a critical role in shaping subcellular cAMP-PKA activities in cardiomyocytes via regulating β(2)AR association with arrestin/PDE4D. Replacing cysteine 341 on β(2)AR with alanine (C341A) leads to an impaired binding to β arrestin 2. Surprisingly, the C341A mutant is able to internalize via an arrestin-independent pathway at saturated concentration of agonist stimulation; the internalization becomes caveolae-dependent and requires dynamin GTPase. However, the impaired binding to β arrestin 2 also leads to an impaired recruitment of PDE4D to the C341A mutant. Thus, the mutant C341A β(2)AR is transported alone from the plasma membrane to the endosome without recruiting PDE4D. This alteration leads to an enhanced cytoplasmic cAMP signal for PKA activation under β(2)AR stimulation. Functionally, Mutation of the C341 residue or inhibition of palmitoylation modification of β(2)AR enhances the receptor-induced PKA activities in the cytoplasm and increases in myocyte contraction rate. Our data reveal a novel function of palmitoylation in shaping subcellular cAMP-PKA signaling in cardiomyocytes via modulating the recruitment of β arrestin 2-PDE4D complexes to the agonist-stimulated β(2)AR.

Palmitoylation Regulates Intracellular Trafficking of β2 Adrenergic Receptor/Arrestin/Phosphodiesterase 4D Complexes in Cardiomyocytes

PubMed Central

Liu, Ruijie; Wang, Dayong; Shi, Qian; Fu, Qin; Hizon, Steven; Xiang, Yang K.

2012-01-01

β2 adrenergic receptor (β2AR) is a prototypical G-protein coupled receptor that stimulates the classic cAMP-protein kinase A (PKA) signaling pathway. Recent studies indicate that the cAMP-PKA activities are spatiotemporally regulated in part due to dynamic association of β2AR with phosphodiesterase 4D (PDE4D), a group of cAMP degradation enzymes. Here, we demonstrate that in cardiomyocytes, palmitoylation of β2AR, the covalent acylation of cysteine residue 341, plays a critical role in shaping subcellular cAMP-PKA activities in cardiomyocytes via regulating β2AR association with arrestin/PDE4D. Replacing cysteine 341 on β2AR with alanine (C341A) leads to an impaired binding to β arrestin 2. Surprisingly, the C341A mutant is able to internalize via an arrestin-independent pathway at saturated concentration of agonist stimulation; the internalization becomes caveolae-dependent and requires dynamin GTPase. However, the impaired binding to β arrestin 2 also leads to an impaired recruitment of PDE4D to the C341A mutant. Thus, the mutant C341A β2AR is transported alone from the plasma membrane to the endosome without recruiting PDE4D. This alteration leads to an enhanced cytoplasmic cAMP signal for PKA activation under β2AR stimulation. Functionally, Mutation of the C341 residue or inhibition of palmitoylation modification of β2AR enhances the receptor-induced PKA activities in the cytoplasm and increases in myocyte contraction rate. Our data reveal a novel function of palmitoylation in shaping subcellular cAMP-PKA signaling in cardiomyocytes via modulating the recruitment of β arrestin 2-PDE4D complexes to the agonist-stimulated β2AR. PMID:22912718

Atrazine acts as an endocrine disrupter by inhibiting cAMP-specific phosphodiesterase-4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kucka, Marek; Pogrmic-Majkic, Kristina; Fa, Svetlana

2012-11-15

Atrazine, one of the most commonly used herbicides worldwide, acts as an endocrine disruptor, but the mechanism of its action has not been characterized. In this study, we show that atrazine rapidly increases cAMP levels in cultured rat pituitary and testicular Leydig cells in a concentration-dependent manner, but less effectively than 3-isobutyl-1-methylxanthine, a competitive non-specific inhibitor of phosphodiesterases (PDEs). In forskolin (an activator of adenylyl cyclase)- and probenecid (an inhibitor of cyclic nucleotide transporters)-treated cells, but not in 3-isobutyl-1-methylxanthine-treated cells, atrazine further increased cAMP levels, indicating that inhibition of PDEs accounts for accumulation of cAMP. In contrast to cAMP, atrazinemore » did not alter cGMP levels, further indicating that it inhibits cAMP-specific PDEs. Atrazine-induced changes in cAMP levels were sufficient to stimulate prolactin release in pituitary cells and androgen production in Leydig cells, indicating that it acts as an endocrine disrupter both in cells that secrete by exocytosis of prestored hormones and in cells that secrete by de novo hormone synthesis. Rolipram abolished the stimulatory effect of atrazine on cAMP release in both cell types, suggesting that it acts as an inhibitor of PDE4s, isoforms whose mRNA transcripts dominate in pituitary and Leydig cells together with mRNA for PDE8A. In contrast, immortalized lacto-somatotrophs showed low expression of these mRNA transcripts and several fold higher cAMP levels compared to normal pituitary cells, and atrazine was unable to further increase cAMP levels. These results indicate that atrazine acts as a general endocrine disrupter by inhibiting cAMP-specific PDE4s. -- Highlights: ► Atrazine stimulates cAMP accumulation in pituitary and Leydig cells. ► Atrazine also stimulates PRL and androgens secretion. ► Stimulatory effects of atrazine were abolished in cells with IBMX-inhibited PDEs. ► Atrazine specificity toward

JAK2-binding long noncoding RNA promotes breast cancer brain metastasis

PubMed Central

Wang, Shouyu; Liang, Ke; Hu, Qingsong; Li, Ping; Song, Jian; Yang, Yuedong; Yao, Jun; Mangala, Lingegowda Selanere; Li, Chunlai; Park, Peter K.; Hawke, David H.; Zhou, Jianwei; Zhou, Yan; Xia, Weiya; Hung, Mien-Chie; Marks, Jeffrey R.; Gallick, Gary E.; Lopez-Berestein, Gabriel; Flores, Elsa R.; Sood, Anil K.; Huang, Suyun; Yu, Dihua; Yang, Liuqing

2017-01-01

Conventional therapies for breast cancer brain metastases (BCBMs) have been largely ineffective because of chemoresistance and impermeability of the blood-brain barrier. A comprehensive understanding of the underlying mechanism that allows breast cancer cells to infiltrate the brain is necessary to circumvent treatment resistance of BCBMs. Here, we determined that expression of a long noncoding RNA (lncRNA) that we have named lncRNA associated with BCBM (Lnc-BM) is prognostic of the progression of brain metastasis in breast cancer patients. In preclinical murine models, elevated Lnc-BM expression drove BCBM, while depletion of Lnc-BM with nanoparticle-encapsulated siRNAs effectively treated BCBM. Lnc-BM increased JAK2 kinase activity to mediate oncostatin M– and IL-6–triggered STAT3 phosphorylation. In breast cancer cells, Lnc-BM promoted STAT3-dependent expression of ICAM1 and CCL2, which mediated vascular co-option and recruitment of macrophages in the brain, respectively. Recruited macrophages in turn produced oncostatin M and IL-6, thereby further activating the Lnc-BM/JAK2/STAT3 pathway and enhancing BCBM. Collectively, our results show that Lnc-BM and JAK2 promote BCBMs by mediating communication between breast cancer cells and the brain microenvironment. Moreover, these results suggest targeting Lnc-BM as a potential strategy for fighting this difficult disease. PMID:29130936

Altered gene expression in rat mesenteric tissue following in vivo exposure to a phosphodiesterase 4 inhibitor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dagues, Nicolas; Pawlowski, Valerie; Guigon, Ghislaine

Vascular injury is a relatively common finding during the pre-clinical toxicity testing of drugs. The mechanisms of the injury are poorly understood and in turn, sensitive and specific biomarkers for pre-clinical and clinical monitoring do not exist. The present study was undertaken to investigate the molecular mechanisms of drug-induced vascular injury in mesenteric tissue of rats treated with the selective phosphodiesterase 4 (PDE4) inhibitor CI-1044. In a time-course study, male Sprague Dawley rats were given daily doses of 40 or 80 mg/kg for 1, 2 or 3 successive days and were euthanized the following day. Gene expression profiles in mesentericmore » tissue were determined using Affymetrix RG{sub U}34A microarrays and fibrinogen and cytokine measurements were performed in blood samples. Hierarchical clustering analysis produced a clear pattern separation of the animals with inflammation, animal with inflammation and necrosis and animals without any lesion. Genes associated with inflammation, procoagulation, extracellular matrix remodeling were up-regulated. An altered expression of genes involved in vascular tone regulation, lipid and glucose metabolism was also observed. Selected genes expression changes were confirmed by TaqMan real-time RT-PCR. The inflammatory process was also detected in the bloodstream at the protein level since fibrinogen, IL6 and IL1{beta} concentrations were increased in treated animals. Overall, the present study reveals several molecular changes supporting the hypothesis by which PDE4 inhibitor-induced vascular lesions in rats are triggered by an inflammatory mechanism and/or a vascular tone dysregulation.« less

Topical therapy for psoriasis: a promising future. Focus on JAK and phosphodiesterase-4 inhibitors.

PubMed

Rafael, Adilia; Torres, Tiago

2016-01-01

Psoriasis is a common, chronic and disabling skin disorder affecting approximately 2% of the population, associated with significant negative impact on the patient's quality of life. Approximately 80% of those affected with psoriasis have mild-to-moderate forms and are usually treated with topical therapy, whereas phototherapy and systemic therapies are used for those with severe disease. In the past three decades, the major advances in psoriasis therapy have been in systemic agents for the treatment of moderate-to-severe psoriasis, particularly new immunomodulatory and biological molecules, while topical therapies have remained relatively unchanged over the past decades. Indeed, topical corticosteroids and vitamin D3 analogs are still the gold standard of therapy for mild-to-moderate psoriasis. Thus, there is a need to develop new and more effective topical agents in the short and long term, with a better efficacy and safety profile than corticosteroids and vitamin D3 analogs. Over the past five years, investigation into topical therapy has expanded, with exciting new drugs being developed. Preliminary results of these emerging agents that selectively target disease-defining pathogenic pathways seem to be promising, although long-term and large-scale studies assessing safety and efficacy are still lacking. The aim of this article was to review the clinical and research data of some emerging topical agents, focusing on Janus kinase-signal transducer and activator of transcription and phosphodiesterase type 4 inhibitors, which are currently being investigated.

Ischemic Brain Injury Leads to Brain Edema via Hyperthermia-Induced TRPV4 Activation.

PubMed

Hoshi, Yutaka; Okabe, Kohki; Shibasaki, Koji; Funatsu, Takashi; Matsuki, Norio; Ikegaya, Yuji; Koyama, Ryuta

2018-06-20

Brain edema is characterized by an increase in net brain water content, which results in an increase in brain volume. Although brain edema is associated with a high fatality rate, the cellular and molecular processes of edema remain largely unclear. Here, we developed an in vitro model of ischemic stroke-induced edema in which male mouse brain slices were treated with oxygen-glucose deprivation (OGD) to mimic ischemia. We continuously measured the cross-sectional area of the brain slice for 150 min under macroscopic microscopy, finding that OGD induces swelling of brain slices. OGD-induced swelling was prevented by pharmacologically blocking or genetically knocking out the transient receptor potential vanilloid 4 (TRPV4), a member of the thermosensitive TRP channel family. Because TRPV4 is activated at around body temperature and its activation is enhanced by heating, we next elevated the temperature of the perfusate in the recording chamber, finding that hyperthermia induces swelling via TRPV4 activation. Furthermore, using the temperature-dependent fluorescence lifetime of a fluorescent-thermosensitive probe, we confirmed that OGD treatment increases the temperature of brain slices through the activation of glutamate receptors. Finally, we found that brain edema following traumatic brain injury was suppressed in TRPV4-deficient male mice in vivo Thus, our study proposes a novel mechanism: hyperthermia activates TRPV4 and induces brain edema after ischemia. SIGNIFICANCE STATEMENT Brain edema is characterized by an increase in net brain water content, which results in an increase in brain volume. Although brain edema is associated with a high fatality rate, the cellular and molecular processes of edema remain unclear. Here, we developed an in vitro model of ischemic stroke-induced edema in which mouse brain slices were treated with oxygen-glucose deprivation. Using this system, we showed that the increase in brain temperature and the following activation of the

[Research of bornrol promote drugs through blood-brain barrier].

PubMed

Lv, Xuxiao; Sun, Mingjiang; Sun, Fengzhi

2012-04-01

Malignant tumor, epilepsy, dementia, cerebral ischemia and other brain diseases have very high rates of disability and mortality. Currently, many drugs are developed to treat such diseases and the effect is obviously. But they can not achieve the purpose to control these diseases because many of the drugs can not pass through the blood-brain barrier (BBB). Therefore, the treatment is not good. Borneol as the represent of the aromatic resuscitation medicine, it has strong fat-soluble active ingredients, small molecular weight, volatile and through the BBB quickly. It can also promote other therapeutic drugs through the BBB. It has two-ways regulations on BBB permeability and the damage of brain tissue is small, this have important theoretical significances and application values.

Antenatal phosphodiesterase 4 inhibition restores postnatal growth and pulmonary development in a model of chorioamnionitis in rabbits.

PubMed

Homer, L; Launay, E; Joram, N; Jacqueline, C; Jarreau, P-H; Caillon, J; Moyon, T; Branger, B; Potel, G; Roze, J C; Méhats, C; Gras-Leguen, C

2012-03-01

Chorioamnionitis is implicated in the pathophysiology of bronchopulmonary disease, and the associated inflammatory response is responsible for adverse effects on alveolar development. The aim of this work was to analyze the effects of a phosphodiesterase 4 (PDE4)-selective inhibitor, rolipram (a modulator of the inflammatory response), in an experimental model of chorioamnionitis on pulmonary development and on the processes of infection and inflammation. Rabbit mothers were assigned to four groups: 1) saline serum inoculation (controls); 2) Escherichia coli intrauterine inoculation (C+); 3) rolipram infusion (R+); and 4) E. coli inoculation + rolipram infusion (C+R+). High rates of morbility and mortality were noticed in mothers and pups (5 of 13 pregnant rabbits in groups with rolipram). Alveolar development, inflammation, and infection were analyzed in pups at day 0 and day 5. At day 0, in the context of chorioamnionitis, rolipram significantly decreased birth weight (p < 0.01) relative to that of controls (p < 0.05). At day 5, weight normalized in group C+R+ but not in group C+ relative to controls (p < 0.001); moreover, alveolar airspace volume was preserved in group C+R+ but not in group C+ (p < 0.05). Interstitial volume decreased in group C+ versus controls (p < 0.05) but was preserved in group C+R+. Specific alveolar area was not significantly modified by rolipram. No significant difference was found concerning bronchoalveolar lavage cellularity, and all blood cultures remained sterile. In this model of impaired alveologenesis, rolipram significantly preserved specific alveolar density. However, PDE4 inhibition induced antenatal fetal demise and growth retardation.

Damage to Arousal-Promoting Brainstem Neurons with Traumatic Brain Injury

PubMed Central

Valko, Philipp O.; Gavrilov, Yuri V.; Yamamoto, Mihoko; Noaín, Daniela; Reddy, Hasini; Haybaeck, Johannes; Weis, Serge; Baumann, Christian R.; Scammell, Thomas E.

2016-01-01

Study Objectives: Coma and chronic sleepiness are common after traumatic brain injury (TBI). Here, we explored whether injury to arousal-promoting brainstem neurons occurs in patients with fatal TBI. Methods: Postmortem examination of 8 TBI patients and 10 controls. Results: Compared to controls, TBI patients had 17% fewer serotonergic neurons in the dorsal raphe nucleus (effect size: 1.25), but the number of serotonergic neurons did not differ in the median raphe nucleus. TBI patients also had 29% fewer noradrenergic neurons in the locus coeruleus (effect size: 0.96). The number of cholinergic neurons in the pedunculopontine and laterodorsal tegmental nuclei (PPT/LDT) was similar in TBI patients and controls. Conclusions: TBI injures arousal-promoting neurons of the mesopontine tegmentum, but this injury is less severe than previously observed in hypothalamic arousal-promoting neurons. Most likely, posttraumatic arousal disturbances are not primarily caused by damage to these brainstem neurons, but arise from an aggregate of injuries, including damage to hypothalamic arousal nuclei and disruption of other arousal-related circuitries. Citation: Valko PO, Gavrilov YV, Yamamoto M, Noain D, Reddy H, Haybaeck J, Weis S, Baumann CR, Scammell TE. Damage to arousal-promoting brainstem neurons with traumatic brain injury. SLEEP 2016;39(6):1249–1252. PMID:27091531

Analysis of proton wires in the enzyme active site suggests a mechanism of c-di-GMP hydrolysis by the EAL domain phosphodiesterases.

PubMed

Grigorenko, Bella L; Knyazeva, Marina A; Nemukhin, Alexander V

2016-11-01

We report for the first time a hydrolysis mechanism of the cyclic dimeric guanosine monophosphate (c-di-GMP) by the EAL domain phosphodiesterases as revealed by molecular simulations. A model system for the enzyme-substrate complex was prepared on the base of the crystal structure of the EAL domain from the BlrP1 protein complexed with c-di-GMP. The nucleophilic hydroxide generated from the bridging water molecule appeared in a favorable position for attack on the phosphorus atom of c-di-GMP. The most difficult task was to find a pathway for a proton transfer to the O3' atom of c-di-GMP to promote the O3'P bond cleavage. We show that the hydrogen bond network extended over the chain of water molecules in the enzyme active site and the Glu359 and Asp303 side chains provides the relevant proton wires. The suggested mechanism is consistent with the structural, mutagenesis, and kinetic experimental studies on the EAL domain phosphodiesterases. Proteins 2016; 84:1670-1680. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Inhibition of chlorine-induced lung injury by the type 4 phosphodiesterase inhibitor rolipram

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Weiyuan; Chen, Jing; Schlueter, Connie F.

2012-09-01

Chlorine is a highly toxic respiratory irritant that when inhaled causes epithelial cell injury, alveolar-capillary barrier disruption, airway hyperreactivity, inflammation, and pulmonary edema. Chlorine is considered a chemical threat agent, and its release through accidental or intentional means has the potential to result in mass casualties from acute lung injury. The type 4 phosphodiesterase inhibitor rolipram was investigated as a rescue treatment for chlorine-induced lung injury. Rolipram inhibits degradation of the intracellular signaling molecule cyclic AMP. Potential beneficial effects of increased cyclic AMP levels include inhibition of pulmonary edema, inflammation, and airway hyperreactivity. Mice were exposed to chlorine (whole bodymore » exposure, 228–270 ppm for 1 h) and were treated with rolipram by intraperitoneal, intranasal, or intramuscular (either aqueous or nanoemulsion formulation) delivery starting 1 h after exposure. Rolipram administered intraperitoneally or intranasally inhibited chlorine-induced pulmonary edema. Minor or no effects were observed on lavage fluid IgM (indicative of plasma protein leakage), KC (Cxcl1, neutrophil chemoattractant), and neutrophils. All routes of administration inhibited chlorine-induced airway hyperreactivity assessed 1 day after exposure. The results of the study suggest that rolipram may be an effective rescue treatment for chlorine-induced lung injury and that both systemic and targeted administration to the respiratory tract were effective routes of delivery. -- Highlights: ► Chlorine causes lung injury when inhaled and is considered a chemical threat agent. ► Rolipram inhibited chlorine-induced pulmonary edema and airway hyperreactivity. ► Post-exposure rolipram treatments by both systemic and local delivery were effective. ► Rolipram shows promise as a rescue treatment for chlorine-induced lung injury.« less

Selective inhibition of phosphodiesterase 5 enhances glutamatergic synaptic plasticity and memory in mice.

PubMed

Uthayathas, Subramaniam; Parameshwaran, Kodeeswaran; Karuppagounder, Senthilkumar S; Ahuja, Manuj; Dhanasekaran, Muralikrishnan; Suppiramaniam, Vishnu

2013-11-01

Phosphodiesterases (PDEs) belong to a family of proteins that control metabolism of cyclic nucleotides. Targeting PDE5, for enhancing cellular function, is one of the therapeutic strategies for male erectile dysfunction. We have investigated whether in vivo inhibition of PDE5, which is expressed in several brain regions, will enhance memory and synaptic transmission in the hippocampus of healthy mice. We have found that acute administration of sildenafil, a specific PDE5 inhibitor, enhanced hippocampus-dependent memory tasks. To elucidate the underlying mechanism in the memory enhancement, effects of sildenafil on long-term potentiation (LTP) were measured. The level of LTP was significantly elevated, with concomitant increases in basal synaptic transmission, in mice treated with sildenafil (1 mg/kg/day) for 15 days compared to control mice. These results suggest that moderate PDE5 inhibition enhances memory by increasing synaptic plasticity and transmission in the hippocampus. Copyright © 2013 Wiley Periodicals, Inc.

Constraint-induced movement therapy promotes brain functional reorganization in stroke patients with hemiplegia

PubMed Central

Wang, Wenqing; Wang, Aihui; Yu, Limin; Han, Xuesong; Jiang, Guiyun; Weng, Changshui; Zhang, Hongwei; Zhou, Zhiqiang

2012-01-01

Stroke patients with hemiplegia exhibit flexor spasms in the upper limb and extensor spasms in the lower limb, and their movement patterns vary greatly. Constraint-induced movement therapy is an upper limb rehabilitation technique used in stroke patients with hemiplegia; however, studies of lower extremity rehabilitation are scarce. In this study, stroke patients with lower limb hemiplegia underwent conventional Bobath therapy for 4 weeks as baseline treatment, followed by constraint-induced movement therapy for an additional 4 weeks. The 10-m maximum walking speed and Berg balance scale scores significantly improved following treatment, and lower extremity motor function also improved. The results of functional MRI showed that constraint-induced movement therapy alleviates the reduction in cerebral functional activation in patients, which indicates activation of functional brain regions and a significant increase in cerebral blood perfusion. These results demonstrate that constraint-induced movement therapy promotes brain functional reorganization in stroke patients with lower limb hemiplegia. PMID:25337108

Activation of the c-Met pathway mobilizes an inflammatory network in the brain microenvironment to promote brain metastasis of breast cancer

PubMed Central

Xing, Fei; Liu, Yin; Sharma, Sambad; Wu, Kerui; Chan, Michael D.; Lo, Hui-Wen; Carpenter, Richard L.; Metheny-Barlow, Linda J.; Zhou, Xiaobo; Qasem, Shadi A.; Pasche, Boris; Watabe, Kounosuke

2016-01-01

Brain metastasis is one of the chief causes of mortality in breast cancer patients, but the mechanisms that drive this process remains poorly understood. Here we report that brain metastatic cells expressing high levels of c-Met promote the metastatic process via inflammatory cytokine upregulation and vascular reprogramming. Activated c-Met signaling promoted adhesion of tumor cells to brain endothelial cells and enhanced neovascularization by inducing the secretion of IL-8 and CXCL1. Additionally, stimulation of IL1β secretion by activation of c-Met induced tumor-associated astrocytes to secrete the c-Met ligand HGF. Thus, a feed-forward mechanism of cytokine release initiated and sustained by c-Met fed a vicious cycle which generated a favorable microenvironment for metastatic cells. Reinforcing our results, we found that pterostilbene, a compound that penetrates the blood-brain barrier, could suppress brain metastasis by targeting c-Met signaling. These findings suggest a potential utility of this natural compound for chemoprevention. PMID:27364556

Interaction between integrin α5 and PDE4D regulates endothelial inflammatory signalling

PubMed Central

Yun, Sanguk; Budatha, Madhusudhan; Dahlman, James E.; Coon, Brian G.; Cameron, Ryan T.; Langer, Robert; Anderson, Daniel G.; Baillie, George; Schwartz, Martin A.

2016-01-01

Atherosclerosis is primarily a disease of lipid metabolism and inflammation; however, it is also closely associated with endothelial extracellular matrix (ECM) remodelling, with fibronectin accumulating in the laminin–collagen basement membrane. To investigate how fibronectin modulates inflammation in arteries, we replaced the cytoplasmic tail of the fibronectin receptor integrin α5 with that of the collagen/laminin receptor integrin α2. This chimaera suppressed inflammatory signalling in endothelial cells on fibronectin and in knock-in mice. Fibronectin promoted inflammation by suppressing anti-inflammatory cAMP. cAMP was activated through endothelial prostacyclin secretion; however, this was ECM-independent. Instead, cells on fibronectin suppressed cAMP via enhanced phosphodiesterase (PDE) activity, through direct binding of integrin α5 to phosphodiesterase-4D5 (PDE4D5), which induced PP2A-dependent dephosphorylation of PDE4D5 on the inhibitory site Ser651. In vivo knockdown of PDE4D5 inhibited inflammation at athero-prone sites. These data elucidate a molecular mechanism linking ECM remodelling and inflammation, thereby identifying a new class of therapeutic targets. PMID:27595237

Development of a novel assay for human tyrosyl DNA phosphodiesterase 2.

PubMed

Adhikari, Sanjay; Karmahapatra, Soumendra K; Elias, Hadi; Dhopeshwarkar, Priyanka; Williams, R Scott; Byers, Stephen; Uren, Aykut; Roy, Rabindra

2011-09-01

Tyrosyl DNA phosphodiesterase 2 (TDP2), a newly discovered enzyme that cleaves 5'-phosphotyrosyl bonds, is a potential target for chemotherapy. TDP2 possesses both 3'- and 5'-tyrosyl-DNA phosphodiesterase activity, which is generally measured in a gel-based assay using 3'- and 5'-phosphotyrosyl linkage at the 3' and 5' ends of an oligonucleotide. To understand the enzymatic mechanism of this novel enzyme, the gel-based assay is useful, but this technique is cumbersome for TDP2 inhibitor screening. For this reason, we have designed a novel assay using p-nitrophenyl-thymidine-5'-phosphate (T5PNP) as a substrate. This assay can be used in continuous colorimetric assays in a 96-well format. We compared the salt and pH effect on product formation with the colorimetric and gel-based assays and showed that they behave similarly. Steady-state kinetic studies showed that the 5' activity of TDP2 is 1000-fold more efficient than T5PNP. Tyrosyl DNA phosphodiesterase 1 (TDP1) and human AP-endonuclease 1 (APE1) could not hydrolyze T5PNP. Sodium orthovanadate, a known inhibitor of TDP2, inhibits product formation from T5PNP by TDP2 (IC(50)=40 mM). Our results suggest that this novel assay system with this new TDP2 substrate can be used for inhibitor screening in a high-throughput manner. Copyright © 2011 Elsevier Inc. All rights reserved.

Phosphodiesterase 10A inhibition attenuates sleep deprivation-induced deficits in long-term fear memory.

PubMed

Guo, Lengqiu; Guo, Zhuangli; Luo, Xiaoqing; Liang, Rui; Yang, Shui; Ren, Haigang; Wang, Guanghui; Zhen, Xuechu

2016-12-02

Sleep, particularly rapid eye movement (REM) sleep, is implicated in the consolidation of emotional memories. In the present study, we investigated the protective effects of a phosphodiesterase 10A (PDE10A) inhibitor MP-10 on deficits in long-term fear memory induced by REM sleep deprivation (REM-SD). REM-SD caused deficits in long-term fear memory, however, MP-10 administration ameliorated the deleterious effects of REM-SD on long term fear memory. Brain-derived neurotropic factor (BDNF) and phosphorylated cAMP response element-binding protein (pCREB) were altered in specific brain regions associated with learning and memory in REM-SD rats. Accordingly, REM-SD caused a significant decrease of pCREB in hippocampus and striatum and a significant decrease of BDNF in the hippocampus, striatum and amygdala, however, MP-10 reversed the effects of REM-SD in a dose-dependent manner. Our findings suggest that REM-SD disrupts the consolidation of long-term fear memory and that administration of MP-10 protects the REM-SD-induced deficits in fear memory, which may be due to the MP-10-induced expression of BDNF in the hippocampus, striatum and amygdala, and phosphorylation of CREB in the hippocampus and striatum. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

rAAV-compatible MiniPromoters for restricted expression in the brain and eye.

PubMed

de Leeuw, Charles N; Korecki, Andrea J; Berry, Garrett E; Hickmott, Jack W; Lam, Siu Ling; Lengyell, Tess C; Bonaguro, Russell J; Borretta, Lisa J; Chopra, Vikramjit; Chou, Alice Y; D'Souza, Cletus A; Kaspieva, Olga; Laprise, Stéphanie; McInerny, Simone C; Portales-Casamar, Elodie; Swanson-Newman, Magdalena I; Wong, Kaelan; Yang, George S; Zhou, Michelle; Jones, Steven J M; Holt, Robert A; Asokan, Aravind; Goldowitz, Daniel; Wasserman, Wyeth W; Simpson, Elizabeth M

2016-05-10

Small promoters that recapitulate endogenous gene expression patterns are important for basic, preclinical, and now clinical research. Recently, there has been a promising revival of gene therapy for diseases with unmet therapeutic needs. To date, most gene therapies have used viral-based ubiquitous promoters-however, promoters that restrict expression to target cells will minimize off-target side effects, broaden the palette of deliverable therapeutics, and thereby improve safety and efficacy. Here, we take steps towards filling the need for such promoters by developing a high-throughput pipeline that goes from genome-based bioinformatic design to rapid testing in vivo. For much of this work, therapeutically interesting Pleiades MiniPromoters (MiniPs; ~4 kb human DNA regulatory elements), previously tested in knock-in mice, were "cut down" to ~2.5 kb and tested in recombinant adeno-associated virus (rAAV), the virus of choice for gene therapy of the central nervous system. To evaluate our methods, we generated 29 experimental rAAV2/9 viruses carrying 19 different MiniPs, which were injected intravenously into neonatal mice to allow broad unbiased distribution, and characterized in neural tissues by X-gal immunohistochemistry for icre, or immunofluorescent detection of GFP. The data showed that 16 of the 19 (84 %) MiniPs recapitulated the expression pattern of their design source. This included expression of: Ple67 in brain raphe nuclei; Ple155 in Purkinje cells of the cerebellum, and retinal bipolar ON cells; Ple261 in endothelial cells of brain blood vessels; and Ple264 in retinal Müller glia. Overall, the methodology and MiniPs presented here represent important advances for basic and preclinical research, and may enable a paradigm shift in gene therapy.

Anxiolytic effects of phosphodiesterase-2 inhibitors associated with increased cGMP signaling.

PubMed

Masood, Anbrin; Huang, Ying; Hajjhussein, Hassan; Xiao, Lan; Li, Hao; Wang, Wei; Hamza, Adel; Zhan, Chang-Guo; O'Donnell, James M

2009-11-01

Phosphodiesterase (PDE)-2 is a component of the nitric-oxide synthase (NOS)/guanylyl cyclase signaling pathway in the brain. Given recent evidence that pharmacologically induced changes in NO-cGMP signaling can affect anxiety-related behaviors, the effects of the PDE2 inhibitors (2-(3,4-dimethoxybenzyl)-7-det-5-methylimidazo-[5,1-f][1,2,4]triazin-4(3H)-one) (Bay 60-7550) and 3-(8-methoxy-1-methyl-2-oxo-7-phenyl-2,3-dihydro-1H-benzo[e][1,4]diazepin-5-yl)benzamide (ND7001), as well as modulators of NO, were assessed on cGMP signaling in neurons and on the behavior of mice in the elevated plus-maze, hole-board, and open-field tests, well established procedures for the evaluation of anxiolytics. Bay 60-7550 (1 microM) and ND7001 (10 microM) increased basal and N-methyl-d-aspartate- or detanonoate-stimulated cGMP in primary cultures of rat cerebral cortical neurons; Bay 60-7550, but not ND7001, also increased cAMP. Increased cGMP signaling, either by administration of the PDE2 inhibitors Bay 60-7550 (0.5, 1, and 3 mg/kg) or ND7001 (1 mg/kg), or the NO donor detanonoate (0.5 mg/kg), antagonized the anxiogenic effects of restraint stress on behavior in the three tests. These drugs also produced anxiolytic effects on behavior in nonstressed mice in the elevated plus-maze and hole-board tests; these effects were antagonized by the guanylyl cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (20 mg/kg). By contrast, the NOS inhibitor N(omega)-nitro-l-arginine methyl ester (50 mg/kg), which reduces cGMP signaling, produced anxiogenic effects similar to restraint stress. Overall, the present behavioral and neurochemical data suggest that PDE2 may be a novel pharmacological target for the development of drugs for the treatment of anxiety disorders.

Aquaporin-4 in brain and spinal cord oedema.

PubMed

Saadoun, S; Papadopoulos, M C

2010-07-28

Brain oedema is a major clinical problem produced by CNS diseases (e.g. stroke, brain tumour, brain abscess) and systemic diseases that secondarily affect the CNS (e.g. hyponatraemia, liver failure). The swollen brain is compressed against the surrounding dura and skull, which causes the intracranial pressure to rise, leading to brain ischaemia, herniation, and ultimately death. A water channel protein, aquaporin-4 (AQP4), is found in astrocyte foot processes (blood-brain border), the glia limitans (subarachnoid cerebrospinal fluid-brain border) and ependyma (ventricular cerebrospinal fluid-brain border). Experiments using mice lacking AQP4 or alpha syntrophin (which secondarily downregulate AQP4) showed that AQP4 facilitates oedema formation in diseases causing cytotoxic (cell swelling) oedema such as cerebral ischaemia, hyponatraemia and meningitis. In contrast, AQP4 facilitates oedema elimination in diseases causing vasogenic (vessel leak) oedema and therefore AQP4 deletion aggravates brain oedema produced by brain tumour and brain abscess. AQP4 is also important in spinal cord oedema. AQP4 deletion was associated with less cord oedema and improved outcome after compression spinal cord injury in mice. Here we consider the possible routes of oedema formation and elimination in the injured cord and speculate about the role of AQP4. Finally we discuss the role of AQP4 in neuromyelitis optica (NMO), an inflammatory demyelinating disease that produces oedema in the spinal cord and optic nerves. NMO patients have circulating AQP4 IgG autoantibody, which is now used for diagnosing NMO. We speculate how NMO-IgG might produce CNS inflammation, demyelination and oedema. Since AQP4 plays a key role in the pathogenesis of CNS oedema, we conclude that AQP4 inhibitors and activators may reduce CNS oedema in many diseases. Copyright (c) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

Phosphodiesterase Inhibition to Target the Synaptic Dysfunction in Alzheimer's Disease

NASA Astrophysics Data System (ADS)

Bales, Kelly R.; Plath, Niels; Svenstrup, Niels; Menniti, Frank S.

Alzheimer's Disease (AD) is a disease of synaptic dysfunction that ultimately proceeds to neuronal death. There is a wealth of evidence that indicates the final common mediator of this neurotoxic process is the formation and actions on synaptotoxic b-amyloid (Aβ). The premise in this review is that synaptic dysfunction may also be an initiating factor in for AD and promote synaptotoxic Aβ formation. This latter hypothesis is consistent with the fact that the most common risk factors for AD, apolipoprotein E (ApoE) allele status, age, education, and fitness, encompass suboptimal synaptic function. Thus, the synaptic dysfunction in AD may be both cause and effect, and remediating synaptic dysfunction in AD may have acute effects on the symptoms present at the initiation of therapy and also slow disease progression. The cyclic nucleotide (cAMP and cGMP) signaling systems are intimately involved in the regulation of synaptic homeostasis. The phosphodiesterases (PDEs) are a superfamily of enzymes that critically regulate spatial and temporal aspects of cyclic nucleotide signaling through metabolic inactivation of cAMP and cGMP. Thus, targeting the PDEs to promote improved synaptic function, or 'synaptic resilience', may be an effective and facile approach to new symptomatic and disease modifying therapies for AD. There continues to be a significant drug discovery effort aimed at discovering PDE inhibitors to treat a variety of neuropsychiatric disorders. Here we review the current status of those efforts as they relate to potential new therapies for AD.

Carcinoma-astrocyte gap junctions promote brain metastasis by cGAMP transfer

PubMed Central

Jin, Xin; Valiente, Manuel; Er, Ekrem Emrah; Lopez-Soto, Alejandro; Jacob, Leni; Patwa, Ruzeen; Shah, Hardik; Xu, Ke; Cross, Justin R.; Massagué, Joan

2016-01-01

SUMMARY Brain metastasis represents a substantial source of morbidity and mortality in various cancers, and is characterized by high resistance to chemotherapy. Here we define the role of the most abundant cell type in the brain, the astrocyte, in promoting brain metastasis. Breast and lung cancer cells express protocadherin 7 (PCDH7) to favor the assembly of carcinoma-astrocyte gap junctions composed of connexin 43 (Cx43). Once engaged with the astrocyte gap-junctional network, brain metastatic cancer cells employ these channels to transfer the second messenger cGAMP to astrocytes, activating the STING pathway and production of inflammatory cytokines IFNα and TNFα. As paracrine signals, these factors activate the STAT1 and NF-κB pathways in brain metastatic cells, which support tumour growth and chemoresistance. The orally bioavailable modulators of gap junctions meclofenamate and tonabersat break this paracrine loop, and we provide proof-of-principle for the applicability of this therapeutic strategy to treat established brain metastasis. PMID:27225120

Beneficial effects of rolipram, a phosphodiesterase 4 specific inhibitor, on testicular torsion-detorsion injury in rats.

PubMed

Abat, Deniz; Bayazıt, Yıldırım; Açıkalın, Arbil; Dağlıoğlu, Kenan; Yenilmez, Ebru Dündar; Altunkol, Adem; Erdoğan, Şeyda; Tuli, Abdullah

2018-04-14

The aim of the study is to investigate the effect of Rolipram, a selective phosphodiesterase 4 inhibitor, on testicular torsion - detorsion injury. Sixty young male rats were divided into five groups. In each group, the right testes of six rats were removed four hours after detorsion for biochemical analysis, and the right testes of the remaining six rats were removed 24 h after detorsion for pathological analysis. In group 1 (sham-operated) right orchiectomy was performed without torsion, and right testes were sent to the laboratory for biochemical and pathologic analyses. In group 2 (control) torsion was applied to the right testes for 60 min, and detorsion was performed without the administration of Rolipram. In group 3 torsion was applied to the right testes for 60 min. 1 mg/kg Rolipram was administered 30 min before detorsion. In group 4 torsion was applied to the right testes for 60 min, and 1 mg/kg Rolipram was administered during detorsion. In group 5 torsion was applied to the right testes for 60 min. 1 mg/kg Rolipram was administered 30 min after detorsion. The malondialdehyde and nitric oxide levels were determined. The rates of necrosis and apoptosis were evaluated by histopathological examination. The level of malondialdehyde was higher in the torsioned groups (Group 2, 3, 4, 5) than that in group 1 (p = 0.004). There was no statistically significant difference between the groups regarding the level of nitric oxide (p = 0.182). Apoptosis was higher in groups 2, 3 and 4 than in group 1; however, apoptosis was similar in group 1 and group 5 (p = 0.122). The level of necrosis in group 1 was similar to that in groups 4 and 5 (p = 0.194 and p = 0.847, respectively). We suggest that the administration of Rolipram can decrease the rate of necrosis and apoptosis in testicular ischaemia-reperfusion injury. Copyright © 2018 Elsevier Inc. All rights reserved.

Sub-efficacious doses of phosphodiesterase 4 and 5 inhibitors improve memory in a mouse model of Alzheimer's disease.

PubMed

Gulisano, Walter; Tropea, Maria Rosaria; Arancio, Ottavio; Palmeri, Agostino; Puzzo, Daniela

2018-06-06

Cyclic nucleotides cAMP and cGMP cooperate to ensure memory acquisition and consolidation. Increasing their levels by phosphodiesterase inhibitors (PDE-Is) enhanced cognitive functions and rescued memory loss in different models of aging and Alzheimer's disease (AD). However, side effects due to the high doses used limited their application in humans. Based on previous studies suggesting that combinations of sub-efficacious doses of cAMP- and cGMP-specific PDE-Is improved synaptic plasticity and memory in physiological conditions, here we aimed to study whether this treatment was effective to counteract the AD phenotype in APPswe mice. We found that a 3-week chronic treatment with a combination of sub-efficacious doses of the cAMP-specific PDE4-I roflumilast (0.01 mg/kg) and the cGMP-specific PDE5-I vardenafil (0.1 mg/kg) improved recognition, spatial and contextual fear memory. Importantly, the cognitive enhancement persisted for 2 months beyond administration. This long-lasting action, and the possibility to minimize side effects due to the low doses used, might open feasible therapeutic strategies against AD. Copyright © 2018 Elsevier Ltd. All rights reserved.

Role of MrkJ, a Phosphodiesterase, in Type 3 Fimbrial Expression and Biofilm Formation in Klebsiella pneumoniae▿

PubMed Central

Johnson, Jeremiah G.; Clegg, Steven

2010-01-01

Klebsiella pneumoniae is an opportunistic pathogen that has been shown to adhere to human extracellular matrices using the type 3 fimbriae. Introduction of plasmids carrying genes known to alter intracellular cyclic-di-GMP pools in Vibrio parahaemolyticus revealed that these genes also altered type 3 fimbrial surface expression in K. pneumoniae. Immediately adjacent to the type 3 fimbrial gene cluster is a gene, mrkJ, that is related to a family of bacterial genes encoding phosphodiesterases. We identify here a role for MrkJ, a functional phosphodiesterase exhibiting homology to EAL domain-containing proteins, in controlling type 3 fimbria production and biofilm formation in K. pneumoniae. Deletion of mrkJ resulted in an increase in type 3 fimbria production and biofilm formation as a result of the accumulation of intracellular cyclic-di-GMP. This gene was shown to encode a functional phosphodiesterase via restoration of motility in a V. parahaemolyticus strain previously shown to accumulate cyclic-di-GMP and in vitro using phosphodiesterase activity assays. The effect of the mrkJ mutation on type 3 fimbrial expression was shown to be at the level of mrkA gene transcription by using quantitative reverse transcription-PCR. These results reveal a previously unknown role for cyclic-di-GMP in type 3 fimbrial production. PMID:20511505

Promoting brain health through exercise and diet in older adults: a physiological perspective

PubMed Central

Pialoux, Vincent; Corbett, Dale; Drogos, Lauren; Erickson, Kirk I.; Eskes, Gail A.

2016-01-01

Abstract The rise in incidence of age‐related cognitive impairment is a global health concern. Ageing is associated with a number of changes in the brain that, collectively, contribute to the declines in cognitive function observed in older adults. Structurally, the ageing brain atrophies as white and grey matter volumes decrease. Oxidative stress and inflammation promote endothelial dysfunction thereby hampering cerebral perfusion and thus delivery of energy substrates and nutrients. Further, the development of amyloid plaques and neurofibrillary tangles contributes to neuronal loss. Of interest, there are substantial inter‐individual differences in the degree to which these physical and functional changes impact upon cognitive function as we grow older. This review describes how engaging in physical activity and cognitive activities and adhering to a Mediterranean style diet promote ‘brain health’. From a physiological perspective, we discuss the effects of these modifiable lifestyle behaviours on the brain, and how some recent human trials are beginning to show some promise as to the effectiveness of lifestyle behaviours in combating cognitive impairment. Moreover, we propose that these lifestyle behaviours, through numerous mechanisms, serve to increase brain, cerebrovascular and cognitive reserve, thereby preserving and enhancing cognitive function for longer. PMID:27524792

Characterization of the 2′,3′ cyclic phosphodiesterase activities of Clostridium thermocellum polynucleotide kinase-phosphatase and bacteriophage λ phosphatase

PubMed Central

Keppetipola, Niroshika; Shuman, Stewart

2007-01-01

Clostridium thermocellum polynucleotide kinase-phosphatase (CthPnkp) catalyzes 5′ and 3′ end-healing reactions that prepare broken RNA termini for sealing by RNA ligase. The central phosphatase domain of CthPnkp belongs to the dinuclear metallophosphoesterase superfamily exemplified by bacteriophage λ phosphatase (λ-Pase). CthPnkp is a Ni2+/Mn2+-dependent phosphodiesterase-monoesterase, active on nucleotide and non-nucleotide substrates, that can be transformed toward narrower metal and substrate specificities via mutations of the active site. Here we characterize the Mn2+-dependent 2′,3′ cyclic nucleotide phosphodiesterase activity of CthPnkp, the reaction most relevant to RNA repair pathways. We find that CthPnkp prefers a 2′,3′ cyclic phosphate to a 3′,5′ cyclic phosphate. A single H189D mutation imposes strict specificity for a 2′,3′ cyclic phosphate, which is cleaved to form a single 2′-NMP product. Analysis of the cyclic phosphodiesterase activities of mutated CthPnkp enzymes illuminates the active site and the structural features that affect substrate affinity and kcat. We also characterize a previously unrecognized phosphodiesterase activity of λ-Pase, which catalyzes hydrolysis of bis-p-nitrophenyl phosphate. λ-Pase also has cyclic phosphodiesterase activity with nucleoside 2′,3′ cyclic phosphates, which it hydrolyzes to yield a mixture of 2′-NMP and 3′-NMP products. We discuss our results in light of available structural and functional data for other phosphodiesterase members of the binuclear metallophosphoesterase family and draw inferences about how differences in active site composition influence catalytic repertoire. PMID:17986465

In vivo effects of phosphodiesterase inhibition on basal cyclic guanosine monophosphate levels in the prefrontal cortex, hippocampus and cerebellum of freely moving rats.

PubMed

Marte, Antonella; Pepicelli, Olimpia; Cavallero, Anna; Raiteri, Maurizio; Fedele, Ernesto

2008-11-15

We have characterized the various phosphodiesterases (PDE) that degrade cyclic GMP in the prefrontal cortex, hippocampus, and cerebellum using the microdialysis technique to measure in vivo extracellular cyclic GMP in awake rats. The following PDE blockers were used (100 and 1,000 microM): 8-methoxymethyl-IBMX (8-MM-IBMX), erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA), milrinone, rolipram, and zaprinast. For solubility reasons, sildenafil was tested only at 100 microM. All drugs were administered locally in the brain regions through the dialysis probe. At 100 microM, 8-MM-IBMX enhanced the cyclic nucleotide extracellular levels in the prefrontal cortex and hippocampus but not in the cerebellum; EHNA and milrinone were active only in the hippocampus; rolipram was devoid of any effect; zaprinast and sildenafil were effective in all three brain areas. At 1 mM, 8-MM-IBMX, milrinone, and zaprinast increased extracellular cyclic GMP in all the brain regions examined, EHNA became active also in the prefrontal cortex and rolipram showed a significant effect only in the cerebellum. This is the first in vivo functional study showing that, in cortex, PDE1, -2, and -5/9 degrade cGMP, with PDE9 probably playing a major role; in hippocampus, PDE5/9 and PDE1 are mainly involved and seem almost equally active, but PDE2 and -3 also contribute; in cerebellum, PDE5/9 are the main cGMP hydrolyzing enzymes, but also PDE1 and -4 significantly operate.

Osthol attenuates neutrophilic oxidative stress and hemorrhagic shock-induced lung injury via inhibition of phosphodiesterase 4.

PubMed

Tsai, Yung-Fong; Yu, Huang-Ping; Chung, Pei-Jen; Leu, Yann-Lii; Kuo, Liang-Mou; Chen, Chun-Yu; Hwang, Tsong-Long

2015-12-01

Oxidative stress caused by neutrophils is an important pathogenic factor in trauma/hemorrhagic (T/H)-induced acute lung injury (ALI). Osthol, a natural coumarin found in traditional medicinal plants, has therapeutic potential in various diseases. However, the pharmacological effects of osthol in human neutrophils and its molecular mechanism of action remain elusive. In this study, our data showed that osthol potently inhibited the production of superoxide anion (O2(•-)) and reactive oxidants derived therefrom as well as expression of CD11b in N-formylmethionylleucylphenylalanine (FMLP)-activated human neutrophils. However, osthol inhibited neutrophil degranulation only slightly and it failed to inhibit the activity of subcellular NADPH oxidase. FMLP-induced phosphorylation of extracellular signal-regulated kinase (ERK) and protein kinase B (Akt) was inhibited by osthol. Notably, osthol increased the cAMP concentration and protein kinase A (PKA) activity in activated neutrophils. PKA inhibitors reversed the inhibitory effects of osthol, suggesting that these are mediated through cAMP/PKA-dependent inhibition of ERK and Akt activation. Furthermore, the activity of cAMP-specific phosphodiesterase (PDE) 4, but not PDE3 or PDE7, was significantly reduced by osthol. In addition, osthol reduced myeloperoxidase activity and pulmonary edema in rats subjected to T/H shock. In conclusion, our data suggest that osthol has effective anti-inflammatory activity in human neutrophils through the suppression of PDE4 and protects significantly against T/H shock-induced ALI in rats. Osthol may have potential for future clinical application as a novel adjunct therapy to treat lung inflammation caused by adverse circulatory conditions. Copyright © 2015 Elsevier Inc. All rights reserved.

Phosphodiesterases regulate airway smooth muscle function in health and disease.

PubMed

Krymskaya, Vera P; Panettieri, Reynold A

2007-01-01

On the basis of structure, regulation, and kinetic properties, phosphodiesterases (PDEs) represent a superfamily of enzymes divided into 11 subfamilies that catalyze cytosolic levels of 3',5'-cyclic adenosine monophosphate (cAMP) or 3',5'-cyclic guanosine monophosphate (cGMP) to 5'-AMP or 5'-GMP, respectively. PDE4 represents the major PDE expressed in inflammatory cells as well as airway smooth muscle (ASM), and selective PDE4 inhibitors provide a broad spectrum of anti-inflammatory effects such as abrogating cytokine and chemokine release from inflammatory cells and inhibiting inflammatory cell trafficking. Due to cell- and tissue-specific gene expression and regulation, PDEs modulate unique organ-based functions. New tools or compounds that selectively inhibit PDE subfamilies and genetically engineered mice deficient in selective isoforms have greatly enhanced our understanding of PDE function in airway inflammation and resident cell function. This chapter will focus on recent advances in our understanding of the role of PDE in regulating ASM function.

Crisaborole Topical Ointment, 2%: A Nonsteroidal, Topical, Anti-Inflammatory Phosphodiesterase 4 Inhibitor in Clinical Development for the Treatment of Atopic Dermatitis.

PubMed

Jarnagin, Kurt; Chanda, Sanjay; Coronado, Dina; Ciaravino, Vic; Zane, Lee T; Guttman-Yassky, Emma; Lebwohl, Mark G

2016-04-01

Crisaborole topical ointment, 2% (formerly known as AN2728) is a benzoxaborole, nonsteroidal, topical, anti-inflammatory phosphodiesterase 4 (PDE4) inhibitor investigational compound that recently completed phase 3 studies for the treatment of mild to moderate atopic dermatitis (AD). The unique configuration of boron within the crisaborole molecule enables selective targeting and inhibition of PDE4, an enzyme that converts the intracellular second messenger 3'5'-cyclic adenosine monophosphate (cAMP) into the active metabolite adenosine monophosphate (AMP). By inhibiting PDE4 and thus increasing levels of cAMP, crisaborole controls inflammation. The use of boron chemistry enabled synthesis of a low-molecular-weight compound (251 daltons), thereby facilitating effective penetration of crisaborole through human skin. In vitro experiments showed that crisaborole inhibits cytokine production from peripheral blood mononuclear cells in a pattern similar to other PDE4 inhibitors and distinct from corticosteroids. Crisaborole also displayed topical anti-inflammatory activity in a skin inflammation model. Once crisaborole reaches systemic circulation after topical application, it is metabolized to inactive metabolites. This limits systemic exposure to crisaborole and systemic PDE4 inhibition. In phase 1 and 2 clinical studies, crisaborole ointment, 2% was generally well tolerated and improved AD disease severity scores, pruritus, and all other AD signs and symptoms. Two large, randomized, controlled, phase 3, pivotal clinical trials assessing the efficacy and safety of crisaborole topical ointment, 2% in children, adolescents, and adults with mild to moderate AD were recently completed with positive results.

Integrin β4 Signaling Promotes Mammary Tumor Cell Adhesion to Brain Microvascular Endothelium by Inducing ErbB2-mediated Secretion of VEGF

PubMed Central

Fan, Jie; Cai, Bin; Zeng, Min; Hao, Yanyan

2015-01-01

Prior studies have indicated that the β4 integrin promotes mammary tumor invasion and metastasis by combining with ErbB2 and amplifying its signaling capacity. However, the effector pathways and cellular functions by which the β4 integrin exerts these effects are incompletely understood. To examine if β4 signaling plays a role during mammary tumor cell adhesion to microvascular endothelium, we have examined ErbB2-transformed mammary tumor cells expressing either a wild-type (WT) or a signaling-defective form of β4 (1355T). We report that WT cells adhere to brain microvascular endothelium in vitro to a significantly larger extent as compared to 1355T cells. Interestingly, integrin β4 signaling does not exert a direct effect on adhesion to the endothelium or the underlying basement membrane. Rather, it enhances ErbB2-dependent expression of VEGF by tumor cells. VEGF in turn disrupts the tight and adherens junctions of endothelial monolayers, enabling the exposure of underlying basement membrane and increasing the adhesion of tumor cells to the intercellular junctions of endothelium. Inhibition of ErbB2 on tumor cells or the VEGFR-2 on endothelial cells suppresses mammary tumor cell adhesion to microvascular endothelium. Our results indicate that β4 signaling regulates VEGF expression by the mammary tumor cells thereby enhancing their adhesion to microvascular endothelium. PMID:21556948

Effect of phosphodiesterase inhibitors in the bladder.

PubMed

Chughtai, Bilal; Ali, Aizaz; Dunphy, Claire; Kaplan, Steven A

2015-01-01

Many aging men will experience lower urinary tract symptoms (LUTS). Phosphodiesterase type 5 (PDE5) inhibitors have shown promise in treating LUTS in these patients. PDE5 inhibitors mediate their effects through several pathways including cAMP, NO/cGMP, K-channel modulated pathways, and the l -cysteine/H 2 S pathway. PDE5 inhibitors exert their effect in muscle cells, nerve fibers, and interstitial cells (ICs). The use of PDE5 inhibitors led to improvement in LUTS. This included urodynamic parameters. PDE5 inhibitors may play a significant role in LUTS due to their effect on the bladder rather than the prostate.

Targeting the Dopamine 1 Receptor or its Downstream Signalling by Inhibiting Phosphodiesterase-1 Improves Cognitive Performance.

PubMed

Pekcec, Anton; Schülert, Niklas; Stierstorfer, Birgit; Deiana, Serena; Dorner-Ciossek, Cornelia; Rosenbrock, Holger

2018-05-03

Insufficient prefrontal dopamine 1 (D1) receptor signalling has been linked to cognitive dysfunction in several psychiatric conditions. Because the phosphodiesterase-1 (PDE1) isoform B (PDE1B) is postulated to regulate D1 receptor-dependent signal transduction, this study intended to elucidate the role of PDE1 for cognitive processes reliant on D1 receptor function. Cognitive performance of the D1 receptor agonist, SKF38393, was studied in the T-maze continuous alternation task and the 5-Choice Serial Reaction Time Task. D1 receptor/ PDE1B double-immunohistochemistry was performed using human and rat prefrontal brain sections. Pharmacological activity of the PDE1 inhibitor, ITI-214, was assessed by measuring the increase of cAMP/ cGMP in prefrontal brain tissue and its effect on working memory performance. Mechanistic studies on modulation of prefrontal neuronal transmission by SKF38393 and ITI-214 were performed using extracellular recordings in brain slices. SKF38393 improved working memory and attentional performance in rodents. D1 receptor/ PDE1B co-expression was verified in both, human and rat prefrontal brain sections. The pharmacological activity of ITI-214 on its target was demonstrated by increased prefrontal cAMP/ cGMP upon administration. In addition, ITI-214 improved working memory performance. SKF38393 and ITI-214 facilitated neuronal transmission in prefrontal brain slices. We hypothesise that PDE1 inhibition may improve working memory performance by increasing prefrontal synaptic transmission and/or postsynaptic D1 receptor signalling, by modulating prefrontal downstream second messenger levels. These data may therefore support the use of PDE1 inhibitors as a potential approach for the treatment of cognitive dysfunction. This article is protected by copyright. All rights reserved.

Efficacy of Selective PDE4D Negative Allosteric Modulators in the Object Retrieval Task in Female Cynomolgus Monkeys (Macaca fascicularis)

PubMed Central

Sutcliffe, Jane S.; Beaumont, Vahri; Watson, James M.; Chew, Chang Sing; Beconi, Maria; Hutcheson, Daniel M.; Dominguez, Celia; Munoz-Sanjuan, Ignacio

2014-01-01

Cyclic adenosine monophosphate (cAMP) signalling plays an important role in synaptic plasticity and information processing in the hippocampal and basal ganglia systems. The augmentation of cAMP signalling through the selective inhibition of phosphodiesterases represents a viable strategy to treat disorders associated with dysfunction of these circuits. The phosphodiesterase (PDE) type 4 inhibitor rolipram has shown significant pro-cognitive effects in neurological disease models, both in rodents and primates. However, competitive non-isoform selective PDE4 inhibitors have a low therapeutic index which has stalled their clinical development. Here, we demonstrate the pro-cognitive effects of selective negative allosteric modulators (NAMs) of PDE4D, D159687 and D159797 in female Cynomolgous macaques, in the object retrieval detour task. The efficacy displayed by these NAMs in a primate cognitive task which engages the corticostriatal circuitry, together with their suitable pharmacokinetic properties and safety profiles, suggests that clinical development of these allosteric modulators should be considered for the treatment of a variety of brain disorders associated with cognitive decline. PMID:25050979

Virtual Screening for the Development of Dual-Inhibitors Targeting Topoisomerase IB and Tyrosyl-DNA Phosphodiesterase 1.

PubMed

Cardamone, Francesca; Pizzi, Simone; Iacovelli, Federico; Falconi, Mattia; Desideri, Alessandro

2017-01-01

Human topoisomerase IB is an important target in cancer therapy and drugs selectively stabilizing the topoisomerase IB-DNA covalent complex are in clinical use for several cancer types. Tyrosyl- DNA phosphodiesterase 1 is involved in the DNA repair resolving the topoisomerase IB-DNA covalent complex that is extremely dangerous for the survival of the cells since it produces an irreversible DNA damage. Given the close biological relationship between these two enzymes, the development of synergistic inhibitors, called dual-inhibitors, is an important challenge in cancer therapy and computer-aided drug design may help in the identification of the best compounds. In this review, an overview of the compounds inhibiting one of the two enzymes or acting as dual inhibitors is provided. Moreover, the general procedures of the virtual screening approach, providing a description of two widely used opensource programs, namely AutoDock4 and AutoDock Vina, are described. Finally, an application of the two programs on a selected number of dual inhibitors for tyrosyl-DNA phosphodiesterase 1 and topoisomerase IB and their performance is briefly discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

21 CFR 530.4 - Advertising and promotion.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Advertising and promotion. 530.4 Section 530.4... DRUGS, FEEDS, AND RELATED PRODUCTS EXTRALABEL DRUG USE IN ANIMALS General Provisions § 530.4 Advertising and promotion. Nothing in this part shall be construed as permitting the advertising or promotion of...

21 CFR 530.4 - Advertising and promotion.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Advertising and promotion. 530.4 Section 530.4... DRUGS, FEEDS, AND RELATED PRODUCTS EXTRALABEL DRUG USE IN ANIMALS General Provisions § 530.4 Advertising and promotion. Nothing in this part shall be construed as permitting the advertising or promotion of...

21 CFR 530.4 - Advertising and promotion.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Advertising and promotion. 530.4 Section 530.4... DRUGS, FEEDS, AND RELATED PRODUCTS EXTRALABEL DRUG USE IN ANIMALS General Provisions § 530.4 Advertising and promotion. Nothing in this part shall be construed as permitting the advertising or promotion of...

21 CFR 530.4 - Advertising and promotion.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Advertising and promotion. 530.4 Section 530.4... DRUGS, FEEDS, AND RELATED PRODUCTS EXTRALABEL DRUG USE IN ANIMALS General Provisions § 530.4 Advertising and promotion. Nothing in this part shall be construed as permitting the advertising or promotion of...

21 CFR 530.4 - Advertising and promotion.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Advertising and promotion. 530.4 Section 530.4... DRUGS, FEEDS, AND RELATED PRODUCTS EXTRALABEL DRUG USE IN ANIMALS General Provisions § 530.4 Advertising and promotion. Nothing in this part shall be construed as permitting the advertising or promotion of...

Advances in targeting cyclic nucleotide phosphodiesterases

PubMed Central

Maurice, Donald H.; Ke, Hengming; Ahmad, Faiyaz; Wang, Yousheng; Chung, Jay; Manganiello, Vincent C.

2014-01-01

Cyclic nucleotide phosphodiesterases (PDEs) catalyse the hydrolysis of cyclic AMP and cyclic GMP, thereby regulating the intracellular concentrations of these cyclic nucleotides, their signalling pathways and, consequently, myriad biological responses in health and disease. Currently, a small number of PDE inhibitors are used clinically for treating the pathophysiological dysregulation of cyclic nucleotide signalling in several disorders, including erectile dysfunction, pulmonary hypertension, acute refractory cardiac failure, intermittent claudication and chronic obstructive pulmonary disease. However, pharmaceutical interest in PDEs has been reignited by the increasing understanding of the roles of individual PDEs in regulating the subcellular compartmentalization of specific cyclic nucleotide signalling pathways, by the structure-based design of novel specific inhibitors and by the development of more sophisticated strategies to target individual PDE variants. PMID:24687066

Phosphodiesterase 4 inhibition as a potential new therapeutic target in obese women with polycystic ovary syndrome.

PubMed

Jensterle, Mojca; Kocjan, Tomaz; Janez, Andrej

2014-08-01

Phosphodiesterase (PDE) enzymes, including members of PDE4, have been investigated in the regulation of endocrine and reproductive functions of ovaries. In addition, selective inhibition of PDE4 enzyme has recently been implicated in the regulation of metabolism with positive effects on glucose homeostasis and weight reduction. The aim of this study was to evaluate whether the PDE4 inhibitor roflumilast affects body weight and hormonal and metabolic status in obese women with polycystic ovary syndrome (PCOS). Design/Participants/Main Outcome Measures: A 12-week prospective randomized open-label study was conducted with 36 obese women with PCOS diagnosed by the National Eunice Kennedy Shriver Institute of Child Health and Human Development criteria that had been pretreated with metformin (MET). They were randomized to MET 1000 mg twice a day or combined treatment (COM) with MET 1000 mg twice a day and roflumilast 500 μg every day. The primary outcome was change in anthropometric measures of obesity. Thirty-one patients (aged 33.8 ± 7.4 y, twice a day 36.4 ± 5.1 kg/m(2), mean ± SD) completed the study: 16 on MET and 15 on COM. Subjects treated with COM lost on average 4.2 ± 2.8 kg compared with a 0.9 ± 2.5 kg weight gain in the MET group (P = .025). Body mass index decreased for 1.6 ± 1.1 kg/m(2) in COM arm compared with increase for 0.9 ± 2.4 kg/m(2) in the MET arm (P = .046). Visceral adipose tissue area as assessed by dual-energy x-ray absorptiometry decreased from 136.7 ± 37.8 to 121.2 ± 36.2 cm(2) in the COM arm compared with an increase from 155.3 ± 61.9 to 166.7 ± 67.2 cm(2) in the MET arm (P = .02). From baseline to study end, both treatment interventions resulted in a significant reduction of androstenedione (P = .013), free T (P = .002), and homeostasis model assessment for insulin resistance score (P = .027) and a significant increase in SHBG (P = .024), although the between-treatment differences of the changes have not been statistically

Resveratrol ameliorates aging-related metabolic phenotypes by inhibiting cAMP phosphodiesterases.

PubMed

Park, Sung-Jun; Ahmad, Faiyaz; Philp, Andrew; Baar, Keith; Williams, Tishan; Luo, Haibin; Ke, Hengming; Rehmann, Holger; Taussig, Ronald; Brown, Alexandra L; Kim, Myung K; Beaven, Michael A; Burgin, Alex B; Manganiello, Vincent; Chung, Jay H

2012-02-03

Resveratrol, a polyphenol in red wine, has been reported as a calorie restriction mimetic with potential antiaging and antidiabetogenic properties. It is widely consumed as a nutritional supplement, but its mechanism of action remains a mystery. Here, we report that the metabolic effects of resveratrol result from competitive inhibition of cAMP-degrading phosphodiesterases, leading to elevated cAMP levels. The resulting activation of Epac1, a cAMP effector protein, increases intracellular Ca(2+) levels and activates the CamKKβ-AMPK pathway via phospholipase C and the ryanodine receptor Ca(2+)-release channel. As a consequence, resveratrol increases NAD(+) and the activity of Sirt1. Inhibiting PDE4 with rolipram reproduces all of the metabolic benefits of resveratrol, including prevention of diet-induced obesity and an increase in mitochondrial function, physical stamina, and glucose tolerance in mice. Therefore, administration of PDE4 inhibitors may also protect against and ameliorate the symptoms of metabolic diseases associated with aging. Copyright © 2012 Elsevier Inc. All rights reserved.

[Human umbilical cord blood mononuclear cell transplantation promotes long-term neurobehavioral functional development of newborn SD rats with hypoxic ischemic brain injury].

PubMed

Huang, Hui-zhi; Wen, Xiao-hong; Liu, Hui; Huang, Jin-hua; Liu, Shang-quan; Ren, Wei-hua; Fang, Wen-xiang; Qian, Yin-feng; Hou, Wei-zhu; Yan, Ming-jie; Yao, You-heng; Li, Wei-Zu; Li, Qian-Jin

2013-06-01

To explore the effect of human umbilical cord blood mononuclear cells (UCBMC) promoting nerve behavior function and brain tissue recovery of neonatal SD rat with hypoxic ischemic brain injury (HIBI). A modified newborn rat model that had a combined hypoxic and ischemic brain injury as described by Rice-Vannucci was used, early nervous reflex, the Morris water maze and walking track analysis were used to evaluate nervous behavioral function, and brain MRI, HE staining to evaluate brain damage recovery. Newborn rat Rice-Vannucci model showed significant brain atrophy, obvious hemiplegia of contralateral limbs,e.g right step length [(7.67 ± 0.46) cm vs. (8.22 ± 0.50) cm, F = 1.494] and toe distance [(0.93 ± 0.06) cm vs. (1.12 ± 0.55) cm, F = 0.186] were significantly reduced compared with left side, learning and memory ability was significantly impaired compared with normal control group (P < 0.01); Cliff aversion [(8.44 ± 2.38) s vs.(14.22 ± 5.07) s, t = 4.618] and negative geotaxis reflex time [(7.26 ± 2.00) s vs. (11.76 ± 3.73) s, t = 4.755] on postnatal 14 days of HIBI+ transplantation group were significantly reduced compared with HIBI+NaCl group (P < 0.01) ; the Morris water maze experiment showed escape latency [ (23.11 ± 6.64) s vs. (34.04 ± 12.95) s, t = 3.356] and swimming distance [ (9.12 ± 1.21) cm vs.(12.70 ± 1.53) cm, t = 17.095] of HIBI+transplantation group were significantly reduced compared with those of HIBI+NaCl group (P < 0.01) ; the residual brain volume on postnatal 10 d [ (75.37 ± 4.53)% vs. (67.17 ± 4.08)%, t = -6.017] and 67 d [ (69.05 ± 3.58)% vs.(60.83 ± 3.69)%, t = -7.148]of HIBI+ transplantation group were significantly larger than those of HIBI+NaCl group (P < 0.01); After human UCBMC transplantation, left cortical edema significantly reduced and nerve cell necrosis of HIBI+ transplantation group is not obvious compared with HIBI+NaCl group. Human UCBMC intraperitoneal transplantation significantly promoted recovery of

Histone methylation at gene promoters is associated with developmental regulation and region-specific expression of ionotropic and metabotropic glutamate receptors in human brain.

PubMed

Stadler, Florian; Kolb, Gabriele; Rubusch, Lothar; Baker, Stephen P; Jones, Edward G; Akbarian, Schahram

2005-07-01

Glutamatergic signaling is regulated, in part, through differential expression of NMDA and AMPA/KA channel subunits and G protein-coupled metabotropic receptors. In human brain, region-specific expression patterns of glutamate receptor genes are maintained over the course of decades, suggesting a role for molecular mechanisms involved in long-term regulation of transcription, including methylation of lysine residues at histone N-terminal tails. Using a native chromatin immunoprecipitation assay, we studied histone methylation marks at proximal promoters of 16 ionotropic and metabotropic glutamate receptor genes (GRIN1,2A-D; GRIA1,3,4; GRIK2,4,5; GRM1,3,4,6,7 ) in cerebellar cortex collected across a wide age range from midgestation to 90 years old. Levels of di- and trimethylated histone H3-lysine 4, which are associated with open chromatin and transcription, showed significant differences between promoters and a robust correlation with corresponding mRNA levels in immature and mature cerebellar cortex. In contrast, levels of trimethylated H3-lysine 27 and H4-lysine 20, two histone modifications defining silenced or condensed chromatin, did not correlate with transcription but were up-regulated overall in adult cerebellum. Furthermore, differential gene expression patterns in prefrontal and cerebellar cortex were reflected by similar differences in H3-lysine 4 methylation at promoters. Together, these findings suggest that histone lysine methylation at gene promoters is involved in developmental regulation and maintenance of region-specific expression patterns of ionotropic and metabotropic glutamate receptors. The association of a specific epigenetic mark, H3-(methyl)-lysine 4, with the molecular architecture of glutamatergic signaling in human brain has potential implications for schizophrenia and other disorders with altered glutamate receptor function.

An Effect of Dexamethasone on Adenosine 3′,5′ -Monophosphate Content and Adenosine 3′,5′ -Monophosphate Phosphodiesterase Activity of Cultured Hepatoma Cells

PubMed Central

Manganiello, Vincent; Vaughan, Martha

1972-01-01

The effect of dexamethasone on adenosine 3′,5′-monophosphate (cAMP) phosphodiesterase activity in cultured HTC hepatoma cells was investigated. Homogenates of these cells contain phosphodiesterase activity with two apparent Michaelis constants for cAMP (2-5 μm and 50 μm). At all substrate concentrations tested, phosphodiesterase activity was decreased 25-40% in cells incubated for 36 hr or more with 1 μm dexamethasone. Acid phosphatase activity in the same cells was not decreased. α-Methyl testosterone, 1 μm, was without effect on phosphodiesterase activity. Incubation for 10 min with epinephrine plus theophylline increased the cAMP content of the HTC cells 3- to 6-fold. In cells incubated for 72 hr with dexamethasone, the basal concentration of cAMP was slightly increased and the increment produced by epinephrine plus theophylline was markedly increased. We believe that in many cells the so-called permissive effects of steroid hormones on cAMP mediated processes may be due to an effect of these hormones on cAMP phosphodiesterase activity similar to that observed in HTC cells incubated with dexamethasone. PMID:4341439

Estrogen promotes the brain metastatic colonization of triple negative breast cancer cells via an astrocyte-mediated paracrine mechanism.

PubMed

Sartorius, C A; Hanna, C T; Gril, B; Cruz, H; Serkova, N J; Huber, K M; Kabos, P; Schedin, T B; Borges, V F; Steeg, P S; Cittelly, D M

2016-06-02

Brain metastases (BM) are a devastating consequence of breast cancer. BM occur more frequently in patients with estrogen receptor-negative (ER-) breast cancer subtypes; HER2 overexpressing (HER2+) tumors and triple-negative (TN) (ER-, progesterone receptor-negative (PR-) and normal HER2) tumors. Young age is an independent risk factor for the development of BM, thus we speculated that higher circulating estrogens in young, pre-menopausal women could exert paracrine effects through the highly estrogen-responsive brain microenvironment. Using a TN experimental metastases model, we demonstrate that ovariectomy decreased the frequency of magnetic resonance imaging-detectable lesions by 56% as compared with estrogen supplementation, and that the combination of ovariectomy and letrozole further reduced the frequency of large lesions to 14.4% of the estrogen control. Human BM expressed 4.2-48.4% ER+ stromal area, particularly ER+ astrocytes. In vitro, E2-treated astrocytes increased proliferation, migration and invasion of 231BR-EGFP cells in an ER-dependent manner. E2 upregulated epidermal growth factor receptor (EGFR) ligands Egf, Ereg and Tgfa mRNA and protein levels in astrocytes, and activated EGFR in brain metastatic cells. Co-culture of 231BR-EGFP cells with E2-treated astrocytes led to the upregulation of the metastatic mediator S100 Calcium-binding protein A4 (S100A4) (1.78-fold, P<0.05). Exogenous EGF increased S100A4 mRNA levels in 231BR-EGFP cells (1.40±0.02-fold, P<0.01 compared with vehicle control) and an EGFR/HER2 inhibitor blocked this effect, suggesting that S100A4 is a downstream effector of EGFR activation. Short hairpin RNA-mediated S100A4 silencing in 231BR-EGFP cells decreased their migration and invasion in response to E2-CM, abolished their increased proliferation in co-cultures with E2-treated astrocytes and decreased brain metastatic colonization. Thus, S100A4 is one effector of the paracrine action of E2 in brain metastatic cells. These

Estrogen promotes the brain metastatic colonization of triple negative breast cancer cells via an astrocyte-mediated paracrine mechanism

PubMed Central

Sartorius, Carol A.; Hanna, Colton T.; Gril, Brunilde; Cruz, Hazel; Serkova, Natalie J.; Huber, Kendra M.; Kabos, Peter; Schedin, Troy B.; Borges, Virginia F.; Steeg, Patricia S.; Cittelly, Diana M.

2015-01-01

Brain metastases (BM) are a devastating consequence of breast cancer. BM occur more frequently in patients with estrogen receptor-negative (ER−) breast cancer subtypes; HER2 overexpressing (HER2+) tumors and triple-negative (TN) (ER−, progesterone receptor-negative (PR−) and normal HER2) tumors. Young age is an independent risk factor for development of BM, thus we speculated that higher circulating estrogens in young, pre-menopausal women could exert paracrine effects through the highly estrogen-responsive brain microenvironment. Using a TN experimental metastases model, we demonstrate that ovariectomy decreased the frequency of MRI detectable lesions by 56% as compared to estrogen supplementation, and that the combination of ovariectomy and letrozole further reduced the frequency of large lesions to 14.4% of the estrogen control. Human BM expressed 4.2-48.4% ER+ stromal area, particularly ER+ astrocytes. In vitro, E2-treated astrocytes increased proliferation, migration and invasion of 231BR-EGFP cells in an ER-dependent manner. E2 upregulated EGFR ligands Egf, Ereg, and Tgfa mRNA and protein levels in astrocytes, and activated EGFR in brain metastatic cells. Co-culture of 231BR-EGFP cells with E2-treated astrocytes led to upregulation of the metastatic mediator S100 Calcium-binding protein A4 (S100A4) (1.78-fold, P<0.05). Exogenous EGF increased S100A4 mRNA levels in 231BR-EGFP cells (1.40±0.02 fold, P<0.01 compared to vehicle-control) and an EGFR/HER2 inhibitor blocked this effect, suggesting that S100A4 is a downstream effector of EGFR activation. ShRNA-mediated S100A4 silencing in 231BR-EGFP cells decreased their migration and invasion in response to E2-CM, abolished their increased proliferation in co-cultures with E2-treated astrocytes, and decreased brain metastatic colonization. Thus, S100A4 is one effector of the paracrine action of E2 in brain metastatic cells. These studies provide a novel mechanism by which estrogens, acting through ER

Substrate-Dependence of Competitive Nucleotide Pyrophosphatase/Phosphodiesterase1 (NPP1) Inhibitors

PubMed Central

Lee, Sang-Yong; Sarkar, Soumya; Bhattarai, Sanjay; Namasivayam, Vigneshwaran; De Jonghe, Steven; Stephan, Holger; Herdewijn, Piet; El-Tayeb, Ali; Müller, Christa E.

2017-01-01

Nucleotide pyrophosphatase/phosphodiesterase type 1 (NPP1) is a membrane glycoprotein involved in the hydrolysis of extracellular nucleotides. Its major substrate is ATP which is converted to AMP and diphosphate. NPP1 was proposed as a new therapeutic target in brain cancer and immuno-oncology. Several NPP1 inhibitors have been reported to date, most of which were evaluated vs. the artificial substrate p-nitrophenyl 5′-thymidine monophosphate (p-Nph-5′-TMP). Recently, we observed large discrepancies in inhibitory potencies for a class of competitive NPP1 inhibitors when tested vs. the artificial substrate p-Nph-5′-TMP as compared to the natural substrate ATP. Therefore, the goal of the present study was to investigate whether inhibitors of human NPP1 generally display substrate-dependent inhibitory potency. Systematic evaluation of nucleotidic as well as non-nucleotidic NPP1 inhibitors revealed significant differences in determined Ki values for competitive, but not for non- and un-competitive inhibitors when tested vs. the frequently used artificial substrate p-Nph-5′-TMP as compared to ATP. Allosteric modulation of NPP1 by p-Nph-5′-TMP may explain these discrepancies. Results obtained using the AMP derivative p-nitrophenyl 5′-adenosine monophosphate (p-Nph-5′-AMP) as an alternative artificial substrate correlated much better with those employing the natural substrate ATP. PMID:28261095

Changes in peak systolic velocity induced by chronic therapy with phosphodiesterase type-5 inhibitor.

PubMed

Sighinolfi, M C; Mofferdin, A; De Stefani, S; Celia, A; Micali, S; Cicero, A F G; Bianchi, G

2006-06-01

The aim of this study was to assess the influence of chronic therapy with phosphodiesterase type-5 inhibitor on penile haemodynamics at colour Doppler ultrasound. Thirty patients affected by erectile dysfunction (ED) of different aetiology tested with the International Index of Erectile Function (IIEF-5) were evaluated with penile colour Doppler ultrasound during basic and dynamic phases (10 microg PGE1) before and after chronic self-administration of sildenafil citrate (dosage: 100 mg as required, two to three times a week) for a period of 5-20 months (mean: 12.3). Treatment was interrupted 14-21 days before the second ultrasound evaluation. Peak systolic velocity (PSV) and end-diastolic velocity (EDV) were recorded by means of colour Doppler; cut off values were 25 and 5 cm s(-1) respectively. Data were compared by nonparametric tests. Twenty-two of the 30 patients showed normal pre-treatment PSV, while eight of 30 had an insufficient arterial flow. Mean pre-treatment EDV was 4.7 +/- 0.5. After chronic therapy with sildenafil, a global improvement of 10.5% on PSV was seen (P < 0.001), without any statistical difference between patients with normal pre-treatment peak and those with a borderline one. No statistically significant changes were found for EDV (P = 0.98). It is concluded that chronic therapy with phosphodiesterase-5 inhibitor results in a significant improvement in PSV values, probably due to a penile chronic vasoactive enhancement.

Attenuation of ethanol abstinence-induced anxiety- and depressive-like behavior by the phosphodiesterase-4 inhibitor rolipram in rodents.

PubMed

Gong, Mei-Fang; Wen, Rui-Ting; Xu, Ying; Pan, Jian-Chun; Fei, Ning; Zhou, Yan-Meng; Xu, Jiang-Ping; Liang, Jian-Hui; Zhang, Han-Ting

2017-10-01

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. 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. 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. 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. These results provide the first demonstration for that PDE4 plays a role in modulating

The 15-LO-1/15-HETE system promotes angiogenesis by upregulating VEGF in ischemic brains.

PubMed

Chen, Li; Zhu, Yan-Mei; Li, Yu-Nong; Li, Peng-Yan; Wang, Di; Liu, Yu; Qu, You-Yang; Zhu, Da-Ling; Zhu, Yu-Lan

2017-09-01

Angiogenesis promotes neurobehavioral recovery after cerebral ischemic stroke. 15(S)-hydroxyeicosatetraenoic acid (15-HETE) is one of the major metabolites of arachidonic acid by 15-lipoxygenase (15-LO) and stimulates the production of vascular endothelial growth factor (VEGF), thus, inducing autocrine-mediated angiogenesis. The present study aimed to investigate the role of 15-LO/15-HETE system on VEGF expression and angiogenesis in brain ischemia. Rat cerebral arterial vascular endothelial cells were used to set up a cell injury model of oxygen-glucose deprivation and reoxygenation (OGD/R), mimicking a condition of brain ischemia. A mouse model of middle cerebral artery occlusion (MCAO) was established. Oxygen-glucose deprivation increased cellular expression of 15-LO-1 and VEGF. Transfection of 15-LO-1 siRNA depleted cells of 15-LO-1, and sequentially induced downregulation of VEGF expression; while, incubation of 15-HETE increased the expression of VEGF. Incubation of 15-HETE attenuated the reduction in cell viability induced by oxygen-glucose deprivation, and promoted cell migration, while transfection of 15-LO-1 siRNA showed an opposite effect. In animal experiments, the density of microvessels in hypoxic regions of brains was significantly increased after MCAO, while intracerebroventricular delivery of 15-LO-1 siRNA significantly reduced the density of microvessels, and downregulates VEGF expression. The results indicate that the 15-LO-1/15-HETE system promotes angiogenesis in ischemic brains by upregulation of VEGF, representing a potential target for improving neurobehavioral recovery after cerebral ischemic stroke.

BK Channel-Mediated Relaxation of Urinary Bladder Smooth Muscle: A Novel Paradigm for Phosphodiesterase Type 4 Regulation of Bladder Function

PubMed Central

Xin, Wenkuan; Li, Ning; Cheng, Qiuping

2014-01-01

Elevation of intracellular cAMP and activation of protein kinase A (PKA) lead to activation of large conductance voltage- and Ca2+-activated K+ (BK) channels, thus attenuation of detrusor smooth muscle (DSM) contractility. In this study, we investigated the mechanism by which pharmacological inhibition of cAMP-specific phosphodiesterase 4 (PDE4) with rolipram or Ro-20-1724 (C15H22N2O3) suppresses guinea pig DSM excitability and contractility. We used high-speed line-scanning confocal microscopy, ratiometric fluorescence Ca2+ imaging, and perforated whole-cell patch-clamp techniques on freshly isolated DSM cells, along with isometric tension recordings of DSM isolated strips. Rolipram caused an increase in the frequency of Ca2+ sparks and the spontaneous transient BK currents (TBKCs), hyperpolarized the cell membrane potential (MP), and decreased the intracellular Ca2+ levels. Blocking BK channels with paxilline reversed the hyperpolarizing effect of rolipram and depolarized the MP back to the control levels. In the presence of H-89 [N-[2-[[3-(4-bromophenyl)-2-propenyl]amino]ethyl]-5-isoquinolinesulfonamide dihydrochloride], a PKA inhibitor, rolipram did not cause MP hyperpolarization. Rolipram or Ro-20-1724 reduced DSM spontaneous and carbachol-induced phasic contraction amplitude, muscle force, duration, and frequency, and electrical field stimulation-induced contraction amplitude, muscle force, and tone. Paxilline recovered DSM contractility, which was suppressed by pretreatment with PDE4 inhibitors. Rolipram had reduced inhibitory effects on DSM contractility in DSM strips pretreated with paxilline. This study revealed a novel cellular mechanism whereby pharmacological inhibition of PDE4 leads to suppression of guinea pig DSM contractility by increasing the frequency of Ca2+ sparks and the functionally coupled TBKCs, consequently hyperpolarizing DSM cell MP. Collectively, this decreases the global intracellular Ca2+ levels and DSM contractility in a BK channel

The secretome of endothelial progenitor cells promotes brain endothelial cell activity through PI3-kinase and MAP-kinase.

PubMed

Di Santo, Stefano; Seiler, Stefanie; Fuchs, Anna-Lena; Staudigl, Jennifer; Widmer, Hans Rudolf

2014-01-01

Angiogenesis and vascular remodelling are crucial events in tissue repair mechanisms promoted by cell transplantation. Current evidence underscores the importance of the soluble factors secreted by stem cells in tissue regeneration. In the present study we investigated the effects of paracrine factors derived from cultured endothelial progenitor cells (EPC) on rat brain endothelial cell properties and addressed the signaling pathways involved. Endothelial cells derived from rat brain (rBCEC4) were incubated with EPC-derived conditioned medium (EPC-CM). The angiogenic response of rBCEC4 to EPC-CM was assessed as effect on cell number, migration and tubular network formation. In addition, we have compared the outcome of the in vitro experiments with the effects on capillary sprouting from rat aortic rings. The specific PI3K/AKT inhibitor LY294002 and the MEK/ERK inhibitor PD98059 were used to study the involvement of these two signaling pathways in the transduction of the angiogenic effects of EPC-CM. Viable cell number, migration and tubule network formation were significantly augmented upon incubation with EPC-CM. Similar findings were observed for aortic ring outgrowth with significantly longer sprouts. The EPC-CM-induced activities were significantly reduced by the blockage of the PI3K/AKT and MEK/ERK signaling pathways. Similarly to the outcome of the rBCEC4 experiments, inhibition of the PI3K/AKT and MEK/ERK pathways significantly interfered with capillary sprouting induced by EPC-CM. The present study demonstrates that EPC-derived paracrine factors substantially promote the angiogenic response of brain microvascular endothelial cells. In addition, our findings identified the PI3K/AKT and MEK/ERK pathways to play a central role in mediating these effects.

Synthesis and biological evaluation of novel quinazoline-4-piperidinesulfamide derivatives as inhibitors of NPP1.

PubMed

Forcellini, Elsa; Boutin, Sophie; Lefebvre, Carole-Anne; Shayhidin, Elnur Elyar; Boulanger, Marie-Chloé; Rhéaume, Gabrielle; Barbeau, Xavier; Lagüe, Patrick; Mathieu, Patrick; Paquin, Jean-François

2018-03-10

The ecto-nucleotide pyrophosphatase/phosphodiesterase-1 (NPP1) was recently shown to promote mineralization of the aortic valve, hence, its inhibition represents a significant target. A quinazoline-4-piperidine sulfamide compound (QPS1) has been described as a specific and non-competitive inhibitor of NPP1. We report herein the synthesis and in vitro inhibition studies of novel quinazoline-4-piperidine sulfamide analogues using QPS1 as the lead compound. Of the 26 derivatives prepared, four compounds were found to have K i  < 105 nM against human NPP1. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Association of Seafood Consumption, Brain Mercury Level, and APOE ε4 Status With Brain Neuropathology in Older Adults

PubMed Central

Morris, Martha Clare; Brockman, John; Schneider, Julie A.; Wang, Yamin; Bennett, David A.; Tangney, Christy C.; van de Rest, Ondine

2017-01-01

IMPORTANCE Seafood consumption is promoted for its many health benefits even though its contamination by mercury, a known neurotoxin, is a growing concern. OBJECTIVE To determine whether seafood consumption is correlated with increased brain mercury levels and also whether seafood consumption or brain mercury levels are correlated with brain neuropathologies. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional analyses of deceased participants in the Memory and Aging Project clinical neuropathological cohort study, 2004–2013. Participants resided in Chicago retirement communities and subsidized housing. The study included 286 autopsied brains of 554 deceased participants (51.6%). The mean (SD) age at death was 89.9 (6.1) years, 67% (193) were women, and the mean (SD) educational attainment was 14.6 (2.7) years. EXPOSURES Seafood intake was first measured by a food frequency questionnaire at a mean of 4.5 years before death. MAIN OUTCOMES AND MEASURES Dementia-related pathologies assessed were Alzheimer disease, Lewy bodies, and the number of macroinfarcts and microinfarcts. Dietary consumption of seafood and n-3 fatty acids was annually assessed by a food frequency questionnaire in the years before death. Tissue concentrations of mercury and selenium were measured using instrumental neutron activation analyses. RESULTS Among the 286 autopsied brains of 544 participants, brain mercury levels were positively correlated with the number of seafood meals consumed per week (ρ = 0.16; P = .02). In models adjusted for age, sex, education, and total energy intake, seafood consumption (≥1 meal[s]/week) was significantly correlated with less Alzheimer disease pathology including lower density of neuritic plaques (β = −0.69 score units [95% CI, −1.34 to −0.04]), less severe and widespread neurofibrillary tangles (β = −0.77 score units [95% CI, −1.52 to −0.02]), and lower neuropathologically defined Alzheimer disease (β = −0.53 score units [95% CI, −0

Regulation of sphingomyelin phosphodiesterase acid-like 3A gene (SMPDL3A) by liver X receptors.

PubMed

Noto, Paul B; Bukhtiyarov, Yuri; Shi, Meng; McKeever, Brian M; McGeehan, Gerard M; Lala, Deepak S

2012-10-01

Liver X receptor (LXR) α and LXRβ function as physiological sensors of cholesterol metabolites (oxysterols), regulating key genes involved in cholesterol and lipid metabolism. LXRs have been extensively studied in both human and rodent cell systems, revealing their potential therapeutic value in the contexts of atherosclerosis and inflammatory diseases. The LXR genome landscape has been investigated in murine macrophages but not in human THP-1 cells, which represent one of the frequently used monocyte/macrophage cell systems to study immune responses. We used a whole-genome screen to detect direct LXR target genes in THP-1 cells treated with two widely used LXR ligands [N-(2,2,2-trifluoroethyl)-N-[4-[2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)-ethyl]phenyl]-benzenesulfonamide (T0901317) and 3-[3-[N-(2-chloro-3-trifluoromethylbenzyl)-(2,2-diphenylethyl)amino]propyloxy] phenylacetic acid hydrochloride (GW3965)]. This screen identified the sphingomyelin phosphodiesterase acid-like 3A (SMPDL3A) gene as a novel LXR-regulated gene, with an LXR response element within its promoter. We investigated the regulation of SMPDL3A gene expression by LXRs across several human and mouse cell types. These studies indicate that the induction of SMPDL3A is LXR-dependent and is restricted to human blood cells with no induction observed in mouse cellular systems.

Postconditioning with repeated mild hypoxia protects neonatal hypoxia-ischemic rats against brain damage and promotes rehabilitation of brain function.

PubMed

Deng, Qingqing; Chang, Yanqun; Cheng, Xiaomao; Luo, Xingang; Zhang, Jing; Tang, Xiaoyuan

2018-05-01

Mild hypoxia conditioning induced by repeated episodes of transient ischemia is a clinically applicable method for protecting the brain against injury after hypoxia-ischemic brain damage. To assess the effect of repeated mild hypoxia postconditioning on brain damage and long-term neural functional recovery after hypoxia-ischemic brain damage. Rats received different protocols of repeated mild hypoxia postconditioning. Seven-day-old rats with hypoxia ischemic brain damage (HIBD) from the left carotid ligation procedure plus 2 h hypoxic stress (8% O 2 at 37 °C) were further receiving repeated mild hypoxia intermittently. The gross anatomy, functional analyses, hypoxia inducible factor 1 alpha (HIF-1a) expression, and neuronal apoptosis of the rat brains were subsequently examined. Compared to the HIBD group, rats postconditioned with mild hypoxia had elevated HIF-1a expression, more Nissl-stain positive cells in their brain tissue and their brains functioned better in behavioral analyses. The recovery of the brain function may be directly linked to the inhibitory effect of HIF-1α on neuronal apoptosis. Furthermore, there were significantly less neuronal apoptosis in the hippocampal CA1 region of the rats postconditioned with mild hypoxia, which might also be related to the higher HIF-1a expression and better brain performance. Overall, these results suggested that postconditioning of neonatal rats after HIBD with mild hypoxia increased HIF-1a expression, exerted a neuroprotective effect and promoted neural functional recovery. Repeated mild hypoxia postconditioning protects neonatal rats with HIBD against brain damage and improves neural functional recovery. Our results may have clinical implications for treating infants with HIBD. Copyright © 2018 Elsevier Inc. All rights reserved.

Recombinant EPF/chaperonin 10 promotes the survival of O4-positive pro-oligodendrocytes prepared from neonatal rat brain.

PubMed

McCombe, P A

2008-12-01

Chaperonin 10 (cpn 10) is a small heat-shock protein that is usually intracellular. Early pregnancy factor (EPF), a biologically active protein that was first described in the serum of pregnant mammals, is homologous to cpn 10. EPF/cpn 10 has been reported to have effects on immunomodulation and cell survival and to inhibit activation of toll-like receptors by lipopolysaccharide. We found that recombinant EPF/cpn 10 was able to suppress experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis, which is a disease causing inflammation and demyelination of the brain and spinal cord. This beneficial effect could be due to anti-inflammatory and/or cell survival properties of EPF/cpn 10. We aimed to assess the effects of cpn 10 on cells of the oligodendrocyte lineage because oligodendrocytes are the brain cells that produce myelin and that are depleted in multiple sclerosis. Two forms of recombinant EPF/cpn 10 were prepared in the pGEX expression system and in the baculovirus expression system. Purified O4(+) pro-oligodendrocytes were prepared from the brains of day-old Wistar rats and isolated by cell sorting with flow cytometry. Single cells were dispensed into micro-well plates and tested for survival in the presence of a range of concentrations of the two forms of cpn 10. We also studied the effects of bFGF, PDGF, IGF-1 and insulin as controls. With cpn 10 present, there was enhanced survival of O4(+) cells.

Fabrication and evaluation of magnetic phosphodiesterase-5 linked nanoparticles as adsorbent for magnetic dispersive solid-phase extraction of inhibitors from Chinese herbal medicine prior to ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry analysis.

PubMed

Tao, Yi; Gu, Xianghui; Li, Weidong; Cai, Baochang

2018-01-12

In the present study, the preparation of the magnetic phosphodiesterase-5 linked Fe 3 O 4 @ SiO 2 nanoparticles was successfully achieved by amide reaction and the magnetic phosphodiesterase-5 linked Fe 3 O 4 @SiO 2 nanoparticles were evaluated as a new adsorbent for magnetic dispersive solid-phase extraction of ligands from medicinal plant samples before the analysis by UHPLC-Q-TOF/MS. The prepared phosphodiesterase-5 linked Fe 3 O 4 @SiO 2 nanoparticles were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, vibration sample magnetometer and potential laser particle size analyzer. The effects of EDC concentration, incubation time and bead-protein ratio on the amount of immobilized protein were studied. The main experimental parameters affect extraction efficiency of ligands, such as wash times, wash solvents, incubation pH, ion strength and incubation temperature, were investigated and optimized by using echinacoside as a model compound. The absolute recovery of echinacoside was ranged from 98.36%-102.16% in Cistanche tubulosa sample under the optimal extraction conditions. Good linearity was observed in the investigated concentration range of 0.006 mgmL -1 -0.97 mgmL -1 (R 2  = 0.9999). The limit of detection was 0.002 mgmL -1 . The RSDs of within-day and between-day precision were less than 2.3%. Due to the excellent magnetic behavior of Fe 3 O 4 @SiO 2 nanoparticles, the proposed method was shown to be simple and rapid. Remarkably, the magnetic phosphodiesterase-5 linked Fe 3 O 4 @SiO 2 nanoparticles could be recycled for ten times with loss of 10% activity. Copyright © 2017 Elsevier B.V. All rights reserved.

Photoaffinity labelling of cyclic GMP-inhibited phosphodiesterase (PDE III) in human and rat platelets and rat tissues: effects of phosphodiesterase inhibitors.

PubMed

Tang, K M; Jang, E K; Haslam, R J

1994-06-15

Ultraviolet irradiation of human platelet cytosol in the presence of 32P-labelled cyclic GMP (cGMP) can specifically label 110, 80, 55, 49 and 38 kDa proteins; the 110 kDa species is the subunit of cGMP-inhibited phosphodiesterase (PDE III) and the 80 kDa species that of cGMP-dependent protein kinase (Tang et al., 1993, Biochem. J. 294, 329). We have now shown that although photolabelling of platelet PDE III was inhibited by unlabelled cGMP, 8-bromo-cGMP and cyclic AMP (cAMP), it was not affected by phosphorothioate analogues of these cyclic nucleotides. Specific concentration-dependent inhibitions of the photolabelling of PDE III were observed with the following PDE inhibitors: trequinsin (IC50 = 13 +/- 2 nM), lixazinone (IC50 = 22 +/- 4 nM), milrinone (IC50 = 56 +/- 12 nM), cilostamide (IC50 = 70 +/- 9 nM), siguazodan (IC50 = 117 +/- 29 nM) and 3-isobutyl 1-methylxanthine (IBMX) (IC50 = 3950 +/- 22 nM). Thus, measurements of the inhibitory effects of compounds on the photolabelling of platelet PDE III provide a simple quantitative means of investigating their actions at a molecular level that avoids the need to purify the enzyme. Photolabelling of rat platelet lysate or rat heart homogenate by [32P]cGMP showed that the 110 kDa PDE III present in human material was replaced by a 115 kDa protein, labelling of which was also blocked by PDE III inhibitors. Heart and other rat tissues contained much less of this putative 115 kDa PDE III than rat platelets. In contrast, the 80 kDa protein was labelled much less in platelets than in many other rat tissue homogenates (e.g., heart, aorta, uterus and lung). Thus, comparison of the relative amounts of specific photolabelled proteins in different cells may provide an indication of different patterns of cyclic nucleotide action. We compared the abilities of phosphodiesterase inhibitors to block the photolabelling of PDE III in human platelet cytosol and to increase the iloprost-stimulated accumulation of cAMP in intact

PDE4 as a target for cognition enhancement

PubMed Central

Richter, Wito; Menniti, Frank S.; Zhang, Han-Ting; Conti, Marco

2014-01-01

Introduction The second messengers cAMP and cGMP mediate fundamental aspects of brain function relevant to memory, learning and cognitive functions. Consequently, cyclic nucleotide phosphodiesterases (PDEs), the enzymes that inactivate the cyclic nucleotides, are promising targets for the development of cognition-enhancing drugs. Areas covered PDE4 is the largest of the eleven mammalian PDE families. This review covers the properties and functions of the PDE4 family, highlighting procognitive and memory-enhancing effects associated with their inactivation. Expert opinion PAN-selective PDE4 inhibitors exert a number of memory- and cognition-enhancing effects and have neuroprotective and neuroregenerative properties in preclinical models. The major hurdle for their clinical application is to target inhibitors to specific PDE4 isoforms relevant to particular cognitive disorders to realize the therapeutic potential while avoiding side effects, in particular emesis and nausea. The PDE4 family comprises four genes, PDE4A-D, each expressed as multiple variants. Progress to date stems from characterization of rodent models with selective ablation of individual PDE4 subtypes, revealing that individual subtypes exert unique and non-redundant functions in the brain. Thus, targeting specific PDE4 subtypes, as well as splicing variants or conformational states, represents a promising strategy to separate the therapeutic benefits from the side effects of PAN-PDE4 inhibitors. PMID:23883342

Emotions promote social interaction by synchronizing brain activity across individuals

PubMed Central

Nummenmaa, Lauri; Glerean, Enrico; Viinikainen, Mikko; Jääskeläinen, Iiro P.; Hari, Riitta; Sams, Mikko

2012-01-01

Sharing others’ emotional states may facilitate understanding their intentions and actions. Here we show that networks of brain areas “tick together” in participants who are viewing similar emotional events in a movie. Participants’ brain activity was measured with functional MRI while they watched movies depicting unpleasant, neutral, and pleasant emotions. After scanning, participants watched the movies again and continuously rated their experience of pleasantness–unpleasantness (i.e., valence) and of arousal–calmness. Pearson’s correlation coefficient was used to derive multisubject voxelwise similarity measures [intersubject correlations (ISCs)] of functional MRI data. Valence and arousal time series were used to predict the moment-to-moment ISCs computed using a 17-s moving average. During movie viewing, participants' brain activity was synchronized in lower- and higher-order sensory areas and in corticolimbic emotion circuits. Negative valence was associated with increased ISC in the emotion-processing network (thalamus, ventral striatum, insula) and in the default-mode network (precuneus, temporoparietal junction, medial prefrontal cortex, posterior superior temporal sulcus). High arousal was associated with increased ISC in the somatosensory cortices and visual and dorsal attention networks comprising the visual cortex, bilateral intraparietal sulci, and frontal eye fields. Seed-voxel–based correlation analysis confirmed that these sets of regions constitute dissociable, functional networks. We propose that negative valence synchronizes individuals’ brain areas supporting emotional sensations and understanding of another’s actions, whereas high arousal directs individuals’ attention to similar features of the environment. By enhancing the synchrony of brain activity across individuals, emotions may promote social interaction and facilitate interpersonal understanding. PMID:22623534

Phosphatidylinositol-specific phospholipase C from Bacillus cereus combines intrinsic phosphotransferase and cyclic phosphodiesterase activities: A sup 31 P NMR study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shashidhar, M.S.; Kuppe, A.; Volwerk, J.J.

1990-09-04

The inositol phosphate products formed during the cleavage of phosphatidylinositol by phosphatidylinositol-specific phospholipase C from Bacillus cereus were analyzed by {sup 31}P NMR. {sup 31}P NMR spectroscopy can distinguish between the inositol phosphate species and phosphatidylinositol. Chemical shift values (with reference to phosphoric acid) observed are {minus}0.41, 3.62, 4.45, and 16.30 ppm for phosphatidylinositol, myo-inositol 1-monophosphate, myo-inositol 2-monophosphate, and myo-inositol 1,2-cyclic monophosphate, respectively. It is shown that under a variety of experimental conditions this phospholipase C cleaves phosphatidylinositol via an intramolecular phosphotransfer reaction producing diacylglycerol and D-myo-inositol 1,2-cyclic monophosphate. The authors also report the new and unexpected observation that themore » phosphatidylinositol-specific phospholipase C from B. cereus is able to hydrolyze the inositol cyclic phosphate to form D-myo-inositol 1-monophosphate. The enzyme, therefore, possesses phosphotransferase and cyclic phosphodiesterase activities. The second reaction requires thousandfold higher enzyme concentrations to be observed by {sup 31}P NMR. This reaction was shown to be regiospecific in that only the 1-phosphate was produced and stereospecific in that only D-myo-inositol 1,2-cyclic monophosphate was hydrolyzed. Inhibition with a monoclonal antibody specific for the B.cereus phospholipase C showed that the cyclic phosphodiesterase activity is intrinsic to the bacterial enzyme. They propose a two-step mechanism for the phosphatidyl-inositol-specific phospholipase C from B. cereus involving sequential phosphotransferase and cyclic phosphodiesterase activities. This mechanism bears a resemblance to the well-known two-step mechanism of pancreatic ribonuclease, RNase A.« less

Brain anatomy of the 4-day-old European rabbit.

PubMed

Schneider, Nanette Y; Datiche, Frédérique; Coureaud, Gérard

2018-05-01

The European rabbit (Oryctolagus cuniculus) is a widely used model in fundamental, medical and veterinary neurosciences. Besides investigations in adults, rabbit pups are relevant to study perinatal neurodevelopment and early behaviour. To date, the rabbit is also the only species in which a pheromone - the mammary pheromone (MP) - emitted by lactating females and active on neonatal adaptation has been described. The MP is crucial since it contributes directly to nipple localisation and oral seizing in neonates, i.e. to their sucking success. It may also be one of the non-photic cues arising from the mother, which stimulates synchronisation of the circadian system during pre-visual developmental stages. Finally, the MP promotes neonatal odour associative and appetitive conditioning in a remarkably rapid and efficient way. For these different reasons, the rabbit offers a currently unique opportunity to determine pheromonal-induced brain processing supporting adaptation early in life. Therefore, it is of interest to create a reference work of the newborn rabbit pup brain, which may constitute a tool for future multi-disciplinary and multi-approach research in this model, and allow comparisons related to the neuroethological basis of social and feeding behaviour among newborns of various species. Here, in line with existing experimental studies, and based on original observations, we propose a functional anatomical description of brain sections in 4-day-old rabbits with a particular focus on seven brain regions which appear important for neonatal perception of sensory signals emitted by the mother, circadian adaptation to the short and single daily nursing of the mother in the nest, and expression of specific motor actions involved in nipple localisation and milk intake. These brain regions involve olfactory circuits, limbic-related areas important in reward, motivation, learning and memory formation, homeostatic areas engaged in food anticipation, and regions

Minimally invasive monitoring of skeletal muscle hypermetabolism induced by the phosphodiesterase-III-inhibitor milrinone and sodium fluoride.

PubMed

Schuster, Frank; Johannsen, Stephan; Roewer, Norbert; Anetseder, Martin

2013-04-01

We hypothesized that the phosphodiesterase-III-inhibitor milrinone and the non-specific G-protein activator sodium fluoride increase the skeletal muscular lactate levels as a sign of a hypermetabolic response. With approval of the local animal care committee Sprague-Dawley rats were killed and artificially perfused either with Ringer's solution or sodium fluoride 110 mM, while milrinone 1.32 mM or Ringer's solution at 1 μl/min was applied via microdialysis probes in both hind limbs. Lactate was measured spectrophotometrically in the dialysate. Baseline lactate levels before drug application did not differ between hind limbs. Local infusion of milrinone via microdialysis did not significantly increase intramuscular lactate concentrations compared with the Ringer control group. Muscular perfusion with sodium fluoride resulted in a significant increase of lactate and was potentiated by combination with local milrinone. Phosphodiesterase-III-inhibition alone does not significantly influence the lactate levels in skeletal muscle of sacrificed rats. Sodium fluoride infusion leads to an intramuscular lactate increase, which was further potentiated by local inhibition of phosphodiesterase-III. The fluoride-mediated hypermetabolic response following sodium fluoride could be a possible explanation for the observed myotoxic adverse effects in individuals treated by fluoride-containing agents. © 2012 The Authors. JPP © 2012. Royal Pharmaceutical Society.

Phosphodiesterase inhibitors in clinical urology.

PubMed

Ückert, Stefan; Kuczyk, Markus A; Oelke, Matthias

2013-05-01

To date, benign diseases of the male and female lower urinary and genital tract, such as erectile dysfunction, bladder overactivity, lower urinary tract symptomatology secondary to benign prostatic hyperplasia and symptoms of female sexual dysfunction (including arousal and orgasmic disorders), can be therapeutically approached by influencing the function of the smooth musculature of the respective tissues. The use of isoenzyme-selective phosphodiesterase (PDE) inhibitors is considered a great opportunity to treat various diseases of the human urogenital tract. PDE inhibitors, in particular the PDE5 (cyclic GMP PDE) inhibitors avanafil, lodenafil, sildenafil, tadalafil, udenafil and vardenafil, are regarded as efficacious, having a fast onset of drug action and an improved effect-to-adverse event ratio, combining a high response rate with the advantage of an on-demand intake. The purpose of this review is to summarize recent as well as potential future indications, namely, erectile dysfunction, Peyronie's disease, overactive bladder, urinary stone disease, lower urinary tract symptomatology secondary to benign prostatic hyperplasia and premature ejaculation, for the use of PDE inhibitors in clinical urology.

Damage to Arousal-Promoting Brainstem Neurons with Traumatic Brain Injury.

PubMed

Valko, Philipp O; Gavrilov, Yuri V; Yamamoto, Mihoko; Noaín, Daniela; Reddy, Hasini; Haybaeck, Johannes; Weis, Serge; Baumann, Christian R; Scammell, Thomas E

2016-06-01

Coma and chronic sleepiness are common after traumatic brain injury (TBI). Here, we explored whether injury to arousal-promoting brainstem neurons occurs in patients with fatal TBI. Postmortem examination of 8 TBI patients and 10 controls. Compared to controls, TBI patients had 17% fewer serotonergic neurons in the dorsal raphe nucleus (effect size: 1.25), but the number of serotonergic neurons did not differ in the median raphe nucleus. TBI patients also had 29% fewer noradrenergic neurons in the locus coeruleus (effect size: 0.96). The number of cholinergic neurons in the pedunculopontine and laterodorsal tegmental nuclei (PPT/LDT) was similar in TBI patients and controls. TBI injures arousal-promoting neurons of the mesopontine tegmentum, but this injury is less severe than previously observed in hypothalamic arousal-promoting neurons. Most likely, posttraumatic arousal disturbances are not primarily caused by damage to these brainstem neurons, but arise from an aggregate of injuries, including damage to hypothalamic arousal nuclei and disruption of other arousal-related circuitries. © 2016 Associated Professional Sleep Societies, LLC.

Galectin-3 released in response to traumatic brain injury acts as an alarmin orchestrating brain immune response and promoting neurodegeneration

PubMed Central

Yip, Ping Kei; Carrillo-Jimenez, Alejandro; King, Paul; Vilalta, Anna; Nomura, Koji; Chau, Chi Cheng; Egerton, Alexander Michael Scott; Liu, Zhuo-Hao; Shetty, Ashray Jayaram; Tremoleda, Jordi L.; Davies, Meirion; Deierborg, Tomas; Priestley, John V.; Brown, Guy Charles; Michael-Titus, Adina Teodora; Venero, Jose Luis; Burguillos, Miguel Angel

2017-01-01

Traumatic brain injury (TBI) is currently a major cause of morbidity and poor quality of life in Western society, with an estimate of 2.5 million people affected per year in Europe, indicating the need for advances in TBI treatment. Within the first 24 h after TBI, several inflammatory response factors become upregulated, including the lectin galectin-3. In this study, using a controlled cortical impact (CCI) model of head injury, we show a large increase in the expression of galectin-3 in microglia and also an increase in the released form of galectin-3 in the cerebrospinal fluid (CSF) 24 h after head injury. We report that galectin-3 can bind to TLR-4, and that administration of a neutralizing antibody against galectin-3 decreases the expression of IL-1β, IL-6, TNFα and NOS2 and promotes neuroprotection in the cortical and hippocampal cell populations after head injury. Long-term analysis demonstrated a significant neuroprotection in the cortical region in the galectin-3 knockout animals in response to TBI. These results suggest that following head trauma, released galectin-3 may act as an alarmin, binding, among other proteins, to TLR-4 and promoting inflammation and neuronal loss. Taking all together, galectin-3 emerges as a clinically relevant target for TBI therapy. PMID:28128358

Traffic Jam at the Blood Brain Barrier Promotes Greater Accumulation of Alzheimer’s Disease Amyloid-β Proteins in the Cerebral Vasculature

PubMed Central

Agyare, Edward K.; Leonard, Sarah R.; Curran, Geoffry L.; Yu, Caroline C.; Lowe, Val J.; Paravastu, Anant K.; Poduslo, Joseph F.; Kandimalla, Karunya K.

2013-01-01

Amyloid-β (Aβ) deposition in the brain vasculature results in cerebral amyloid angiopathy (CAA), which occurs in about 80% of Alzheimer’s disease (AD) patients. While Aβ42 predominates parenchymal amyloid plaques in AD brain, Aβ40 is prevalent in the cerebrovascular amyloid. Dutch mutation of Aβ40 (E22Q) promotes aggressive cerebrovascular accumulation and leads to severe CAA in the mutation carriers; knowledge of how DutchAβ40 drives this process more efficiently than Aβ40 could reveal various pathophysiological events that promote CAA. In this study we have demonstrated that DutchAβ40 show preferential accumulation in the blood-brain-barrier (BBB) endothelial cells due to its inefficient blood-to-brain transcytosis. Consequently, DutchAβ40 establishes a permeation barrier in the BBB endothelium, prevents its own clearance from the brain and promotes the formation of amyloid deposits in the cerebral microvessels. The BBB endothelial accumulation of native Aβ40 is not robust enough to exercise such a significant impact on its brain clearance. Hence, the cerebrovascular accumulation of Aβ40 is slow and may require other co-pathologies to precipitate into CAA. In conclusion, the magnitude of Aβ accumulation in the BBB endothelial cells is a critical factor that promotes CAA; hence, clearing vascular endothelium of Aβ proteins may halt or even reverse CAA. PMID:23249146

Quantification of 18F-JNJ-42259152, a novel phosphodiesterase 10A PET tracer: kinetic modeling and test-retest study in human brain.

PubMed

Van Laere, Koen; Ahmad, Rawaha U; Hudyana, Hendra; Dubois, Kristof; Schmidt, Mark E; Celen, Sofie; Bormans, Guy; Koole, Michel

2013-08-01

Phosphodiesterase 10A (PDE10A) plays a central role in striatal signaling and is implicated in several neuropsychiatric disorders, such as movement disorders and schizophrenia. We performed initial brain kinetic modeling of the novel PDE10A tracer (18)F-JNJ-42259152 (2-[[4-[1-(2-(18)F-fluoroethyl)-4-(4-pyridinyl)-1H-pyrazol-3-yl]phenoxy]methyl]-3,5-dimethyl-pyridine) and studied test-retest reproducibility in healthy volunteers. Twelve healthy volunteers (5 men, 7 women; age range, 42-77 y) were scanned dynamically up to 135 min after bolus injection of 172.5 ± 10.3 MBq of (18)F-JNJ42259152. Four volunteers (2 men, 2 women) underwent retest scanning, with a mean interscan interval of 37 d. Input functions and tracer parent fractions were determined using arterial sampling and high-performance liquid chromatography analysis. Volumes of interest for the putamen, caudate nucleus, ventral striatum, substantia nigra, thalamus, frontal cortex, and cerebellum were delineated using individual volumetric T1 MR imaging scans. One-tissue (1T) and 2-tissue (2T) models were evaluated to calculate total distribution volume (VT). Simplified models were also tested to calculate binding potential (BPND), including the simplified reference tissue model (SRTM) and multilinear reference tissue model, using the frontal cortex as the optimal reference tissue. The stability of VT and BPND was assessed down to a 60-min scan time. The average intact tracer half-life in blood was 90 min. The 2T model VT values for the putamen, caudate nucleus, ventral striatum, substantia nigra, thalamus, frontal cortex, and cerebellum were 1.54 ± 0.37, 0.90 ± 0.24, 0.64 ± 0.18, 0.42 ± 0.09, 0.35 ± 0.09, 0.30 ± 0.07, and 0.36 ± 0.12, respectively. The 1T model provided significantly lower VT values, which were well correlated to the 2T VT. SRTM BPND values referenced to the frontal cortex were 3.45 ± 0.43, 1.78 ± 0.35, 1.10 ± 0.31, and 0.44 ± 0.09 for the respective target regions putamen

Characterization of [11C]Lu AE92686 as a PET radioligand for phosphodiesterase 10A in the nonhuman primate brain.

PubMed

Yang, Kai-Chun; Stepanov, Vladimir; Amini, Nahid; Martinsson, Stefan; Takano, Akihiro; Nielsen, Jacob; Bundgaard, Christoffer; Bang-Andersen, Benny; Grimwood, Sarah; Halldin, Christer; Farde, Lars; Finnema, Sjoerd J

2017-02-01

[ 11 C]Lu AE92686 is a positron emission tomography (PET) radioligand that has recently been validated for examining phosphodiesterase 10A (PDE10A) in the human striatum. [ 11 C]Lu AE92686 has high affinity for PDE10A (IC 50  = 0.39 nM) and may also be suitable for examination of the substantia nigra, a region with low density of PDE10A. Here, we report characterization of regional [ 11 C]Lu AE92686 binding to PDE10A in the nonhuman primate (NHP) brain. A total of 11 PET measurements, seven baseline and four following pretreatment with unlabeled Lu AE92686 or the structurally unrelated PDE10A inhibitor MP-10, were performed in five NHPs using a high resolution research tomograph (HRRT). [ 11 C]Lu AE92686 binding was quantified using a radiometabolite-corrected arterial input function and compartmental and graphical modeling approaches. Regional time-activity curves were best described with the two-tissue compartment model (2TCM). However, the distribution volume (V T ) values for all regions were obtained by the Logan plot analysis, as reliable cerebellar V T values could not be derived by the 2TCM. For cerebellum, a proposed reference region, V T values increased by ∼30 % with increasing PET measurement duration from 63 to 123 min, while V T values in target regions remained stable. Both pretreatment drugs significantly decreased [ 11 C]Lu AE92686 binding in target regions, while no significant effect on cerebellum was observed. Binding potential (BP ND ) values, derived with the simplified reference tissue model (SRTM), were 13-17 in putamen and 3-5 in substantia nigra and correlated well to values from the Logan plot analysis. The method proposed for quantification of [ 11 C]Lu AE92686 binding in applied studies in NHP is based on 63 min PET data and SRTM with cerebellum as a reference region. The study supports that [ 11 C]Lu AE92686 can be used for PET examinations of PDE10A binding also in substantia nigra.

[Functional analysis of Oct4 promoter in Xuhuai goat].

PubMed

Wei, Guanghui; Li, Dong; Zuo, Qisheng; Zhang, Yani; Zhu, Rui; Zhang, Lei; Liu, Zhiyong; Qiu, Fenglong; Li, Bichun

2014-08-01

The aim of this study was to determine the activity region of Oct4 (octamer-binding transcription factor 4) promoter in Xuhuai goat, and to investigate the effect of TSA (trichostatin A) and VPA(valproicacid) on Oct4 promoter activity. Specific PCR primers of Oct4 promoter including different lengths of fragments were designed by Primer 5.0, then were amplified and cloned into PGL3-Bacic luciferase reporter vector. All the reconstruction vectors were transfected into gEF, P19 and COS7 cells, respectively. After TSA and VPA treatment, the activity of dual-luciferase reporter gene in these three transfected cells was detected. In addition, the CMV promoter of pEGFP-N1 was replaced by the -1516─+30 bp fragment of Oct4 promoter, GFP fluorescence was used to detect the activity of Oct4 promoter. The results indicated that different fragments of Oct4 promoter showed different degrees of activity in gEF, P19 and COS7 cells, and the maximal activity region of Oct4 promoter was -1516─+30 bp, the basal activity region was -238─+30 bp. Positive regulatory domains existed in the region of -1516─-946 bp and -615─-96 bp, while negative regulatory domains existed in the region of -1936─-1516 bp and -946─-615 bp. The optimum induction concentration to enhance the activity of Oct4 promoter was 1 μmol/L of TSA and 4 mmol/L of VPA. The GFP expression can be started by the fragment of -1516─+30 bp. This study provides an experimental basis for revealing the mechanism of expression and regulation of Oct4 in goat.

Effects of high-pressure oxygen therapy on brain tissue water content and AQP4 expression in rabbits with cerebral hemorrhage.

PubMed

Wu, Jing; Chen, Jiong; Guo, Hua; Peng, Fang

2014-12-01

To investigate the effects of different atmosphere absolutes (ATA) of high-pressure oxygen (HPO) on brain tissue water content and Aquaporin-4 (AQP4) expression in rabbits with cerebral hemorrhage. 180 New Zealand white rabbits were selected and randomly divided into normal group (n = 30), control group (n = 30) and cerebral hemorrhage group (n = 120), and cerebral hemorrhage group was divided into group A, B, C and D with 30 rabbits in each group. The groups received 1.0, 1.8, 2.0 and 2.2 ATA of HPO treatments, respectively. Ten rabbits in each group were killed at first, third and fifth day to detect the brain tissue water content and change of AQP4 expression. In cerebral hemorrhage group, brain tissue water content and AQP4 expression after model establishment were first increased, then decreased and reached the maximum on third day (p < 0.05). Brain tissue water content and AQP4 expression in control group and cerebral hemorrhage group were significantly higher than normal group at different time points (p < 0.05). In contrast, brain tissue water content and AQP4 expression in group C were significantly lower than in group A, group B, group D and control group (p < 0.05). In control group, AQP4-positive cells significantly increased after model establishment, which reached maximum on third day, and positive cells in group C were significantly less than in group A, group B and group D. We also found that AQP4 expression were positively correlated with brain tissue water content (r = 0.719, p < 0.05) demonstrated by significantly increased AQP4 expression along with increased brain tissue water content. In conclusion, HPO can decrease AQP4 expression in brain tissue of rabbits with cerebral hemorrhage to suppress the progression of brain edema and promote repairing of injured tissue. 2.0 ATA HPO exerts best effects, which provides an experimental basis for ATA selection of HPO in treating cerebral hemorrhage.

37 CFR 4.1 - Complaints regarding invention promoters.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Complaints regarding invention promoters. 4.1 Section 4.1 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL COMPLAINTS REGARDING INVENTION PROMOTERS § 4.1 Complaints...

Maintaining brain health by monitoring inflammatory processes: a mechanism to promote successful aging.

PubMed

Rosano, Caterina; Marsland, Anna L; Gianaros, Peter J

2012-02-01

Maintaining brain health promotes successful aging. The main determinants of brain health are the preservation of cognitive function and remaining free from structural and metabolic abnormalities, including loss of neuronal synapses, atrophy, small vessel disease and focal amyloid deposits visible by neuroimaging. Promising studies indicate that these determinants are to some extent modifiable, even among adults seventy years and older. Converging animal and human evidence further suggests that inflammation is a shared mechanism, contributing to both cognitive decline and abnormalities in brain structure and metabolism. Thus, inflammation may provide a target for intervention. Specifically, circulating inflammatory markers have been associated with declines in cognitive function and worsening of brain structural and metabolic characteristics. Additionally, it has been proposed that older brains are characterized by a sensitization to neuroinflammatory responses, even in the absence of overt disease. This increased propensity to central inflammation may contribute to poor brain health and premature brain aging. Still unknown is whether and how peripheral inflammatory factors directly contribute to decline of brain health. Human research is limited by the challenges of directly measuring neuroinflammation in vivo. This review assesses the role that inflammation may play in the brain changes that often accompany aging, focusing on relationships between peripheral inflammatory markers and brain health among well-functioning, community-dwelling adults seventy years and older. We propose that monitoring and maintaining lower levels of systemic and central inflammation among older adults could help preserve brain health and support successful aging. Hence, we also identify plausible ways and novel experimental study designs of maintaining brain health late in age through interventions that target the immune system.

Glycerophosphodiester phosphodiesterases play an important role in phosphate recycling and phosphate sensing in white lupin

USDA-ARS?s Scientific Manuscript database

White lupin (Lupinus albus L.), a well adapted species to phosphate (Pi) impoverished soils, develops short, densely clustered lateral roots (cluster/proteoid roots) to increase Pi uptake. Here, we report two white lupin glycerophosphodiester phosphodiesterase (GPX-PDE) genes which share strong homo...

Recurrently Mutated Genes Differ between Leptomeningeal and Solid Lung Cancer Brain Metastases.

PubMed

Li, Yingmei; Liu, Boxiang; Connolly, Ian David; Kakusa, Bina Wasunga; Pan, Wenying; Nagpal, Seema; Montgomery, Stephen B; Hayden Gephart, Melanie

2018-03-29

When compared with solid brain metastases from NSCLC, leptomeningeal disease (LMD) has unique growth patterns and is rapidly fatal. Patients with LMD do not undergo surgical resection, limiting the tissue available for scientific research. In this study we performed whole exome sequencing on eight samples of LMD to identify somatic mutations and compared the results with those for 26 solid brain metastases. We found that taste 2 receptor member 31 gene (TAS2R31) and phosphodiesterase 4D interacting protein gene (PDE4DIP) were recurrently mutated among LMD samples, suggesting involvement in LMD progression. Together with a retrospective review of the charts of an additional 44 patients with NSCLC LMD, we discovered a surprisingly low number of KRAS mutations (n = 4 [7.7%]) but a high number of EGFR mutations (n = 33 [63.5%]). The median interval for development of LMD from NSCLC was shorter in patients with mutant EGFR (16.3 months) than in patients with wild-type EGFR (23.9 months) (p = 0.017). Targeted analysis of recurrent mutations thus presents a useful complement to the existing diagnostic tool kit, and correlations of EGFR in LMD and KRAS in solid metastases suggest that molecular distinctions or systemic treatment pressure underpin the differences in growth patterns within the brain. Copyright © 2018 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

Evidence for a membrane defect in Alzheimer disease brain

NASA Technical Reports Server (NTRS)

Nitsch, R. M.; Blusztajn, J. K.; Pittas, A. G.; Slack, B. E.; Growdon, J. H.; Wurtman, R. J.

1992-01-01

To determine whether neurodegeneration in Alzheimer disease brain is associated with degradation of structural cell membrane molecules, we measured tissue levels of the major membrane phospholipids and their metabolites in three cortical areas from postmortem brains of Alzheimer disease patients and matched controls. Among phospholipids, there was a significant (P less than 0.05) decrease in phosphatidylcholine and phosphatidylethanolamine. There were significant (P less than 0.05) decreases in the initial phospholipid precursors choline and ethanolamine and increases in the phospholipid deacylation product glycerophosphocholine. The ratios of glycerophosphocholine to choline and glycerophosphoethanolamine to ethanolamine were significantly increased in all examined Alzheimer disease brain regions. The activity of the glycerophosphocholine-degrading enzyme glycerophosphocholine choline-phosphodiesterase was normal in Alzheimer disease brain. There was a near stoichiometric relationship between the decrease in phospholipids and the increase of phospholipid catabolites. These data are consistent with increased membrane phospholipid degradation in Alzheimer disease brain. Similar phospholipid abnormalities were not detected in brains of patients with Huntington disease, Parkinson disease, or Down syndrome. We conclude that the phospholipid abnormalities described here are not an epiphenomenon of neurodegeneration and that they may be specific for the pathomechanism of Alzheimer disease.

Efficacy and safety of crisaborole ointment, a novel, nonsteroidal phosphodiesterase 4 (PDE4) inhibitor for the topical treatment of atopic dermatitis (AD) in children and adults.

PubMed

Paller, Amy S; Tom, Wynnis L; Lebwohl, Mark G; Blumenthal, Robin L; Boguniewicz, Mark; Call, Robert S; Eichenfield, Lawrence F; Forsha, Douglass W; Rees, William C; Simpson, Eric L; Spellman, Mary C; Stein Gold, Linda F; Zaenglein, Andrea L; Hughes, Matilda H; Zane, Lee T; Hebert, Adelaide A

2016-09-01

Additional topical treatments for atopic dermatitis (AD) are needed that provide relief while minimizing risks. We sought to assess the efficacy and safety of crisaborole ointment, a phosphodiesterase 4 inhibitor, in two phase III AD studies (AD-301: NCT02118766; AD-302: NCT02118792). Two identically designed, vehicle-controlled, double-blind studies enrolled and randomly assigned (2:1, crisaborole:vehicle) patients aged 2 years or older with an Investigator's Static Global Assessment (ISGA) score of mild or moderate for twice-daily application for 28 days. The primary end point was ISGA score at day 29 of clear (0)/almost clear (1) with 2-grade or greater improvement from baseline. Additional analyses included time to success in ISGA score, percentage of patients achieving clear/almost clear, reduction in severity of AD signs, and time to improvement in pruritus. More crisaborole- than vehicle-treated patients achieved ISGA score success (clear/almost clear with ≥2-grade improvement; AD-301: 32.8% vs 25.4%, P = .038; AD-302: 31.4% vs 18.0%, P < .001), with a greater percentage with clear/almost clear (51.7% vs 40.6%, P = .005; 48.5% vs 29.7%, P < .001). Crisaborole-treated patients achieved success in ISGA score and improvement in pruritus earlier than those treated with vehicle (both P ≤ .001). Treatment-related adverse events were infrequent and mild to moderate in severity. Short study duration was a limitation. Crisaborole demonstrated a favorable safety profile and improvement in all measures of efficacy, including overall disease severity, pruritus, and other signs of AD. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Cyclic Nucleotide Phosphodiesterases: important signaling modulators and therapeutic targets

PubMed Central

Ahmad, Faiyaz; Murata, Taku; Simizu, Kasumi; Degerman, Eva; Maurice, Donald; Manganiello, Vincent

2014-01-01

By catalyzing hydrolysis of cAMP and cGMP, cyclic nucleotide phosphodiesterases are critical regulators of their intracellular concentrations and their biological effects. Since these intracellular second messengers control many cellular homeostatic processes, dysregulation of their signals and signaling pathways initiate or modulate pathophysiological pathways related to various disease states, including erectile dysfunction, pulmonary hypertension, acute refractory cardiac failure, intermittent claudication, chronic obstructive pulmonary disease, and psoriasis. Alterations in expression of PDEs and PDE-gene mutations (especially mutations in PDE6, PDE8B, PDE11A and PDE4) have been implicated in various diseases and cancer pathologies. PDEs also play important role in formation and function of multi-molecular signaling/regulatory complexes called signalosomes. At specific intracellular locations, individual PDEs, together with pathway-specific signaling molecules, regulators, and effectors, are incorporated into specific signalosomes, where they facilitate and regulate compartmentalization of cyclic nucleotide signaling pathways and specific cellular functions. Currently, only a limited number of PDE inhibitors (PDE3, PDE4, PDE5 inhibitors) are used in clinical practice. Future paths to novel drug discovery include the crystal structure-based design approach, which has resulted in generation of more effective family-selective inhibitors, as well as burgeoning development of strategies to alter compartmentalized cyclic nucleotide signaling pathways by selectively targeting individual PDEs and their signalosome partners. PMID:25056711

Endothelial protein kinase MAP4K4 promotes vascular inflammation and atherosclerosis

PubMed Central

Roth Flach, Rachel J.; Skoura, Athanasia; Matevossian, Anouch; Danai, Laura V.; Zheng, Wei; Cortes, Christian; Bhattacharya, Samit K.; Aouadi, Myriam; Hagan, Nana; Yawe, Joseph C.; Vangala, Pranitha; Menendez, Lorena Garcia; Cooper, Marcus P.; Fitzgibbons, Timothy P.; Buckbinder, Leonard; Czech, Michael P.

2015-01-01

Signalling pathways that control endothelial cell (EC) permeability, leukocyte adhesion and inflammation are pivotal for atherosclerosis initiation and progression. Here we demonstrate that the Sterile-20-like mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4), which has been implicated in inflammation, is abundantly expressed in ECs and in atherosclerotic plaques from mice and humans. On the basis of endothelial-specific MAP4K4 gene silencing and gene ablation experiments in Apoe−/− mice, we show that MAP4K4 in ECs markedly promotes Western diet-induced aortic macrophage accumulation and atherosclerotic plaque development. Treatment of Apoe−/− and Ldlr−/− mice with a selective small-molecule MAP4K4 inhibitor also markedly reduces atherosclerotic lesion area. MAP4K4 silencing in cultured ECs attenuates cell surface adhesion molecule expression while reducing nuclear localization and activity of NFκB, which is critical for promoting EC activation and atherosclerosis. Taken together, these results reveal that MAP4K4 is a key signalling node that promotes immune cell recruitment in atherosclerosis. PMID:26688060

Promoting social plasticity in developmental disorders with non-invasive brain stimulation techniques

PubMed Central

Boggio, Paulo S.; Asthana, Manish K.; Costa, Thiago L.; Valasek, Cláudia A.; Osório, Ana A. C.

2015-01-01

Being socially connected directly impacts our basic needs and survival. People with deficits in social cognition might exhibit abnormal behaviors and face many challenges in our highly social-dependent world. These challenges and limitations are associated with a substantial economical and subjective impact. As many conditions where social cognition is affected are highly prevalent, more treatments have to be developed. Based on recent research, we review studies where non-invasive neuromodulatory techniques have been used to promote Social Plasticity in developmental disorders. We focused on three populations where non-invasive brain stimulation seems to be a promising approach in inducing social plasticity: Schizophrenia, Autism Spectrum Disorder (ASD) and Williams Syndrome (WS). There are still very few studies directly evaluating the effects of transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) in the social cognition of these populations. However, when considering the promising preliminary evidences presented in this review and the limited amount of clinical interventions available for treating social cognition deficits in these populations today, it is clear that the social neuroscientist arsenal may profit from non-invasive brain stimulation techniques for rehabilitation and promotion of social plasticity. PMID:26388712

Caffeine and adenosine.

PubMed

Ribeiro, Joaquim A; Sebastião, Ana M

2010-01-01

Caffeine causes most of its biological effects via antagonizing all types of adenosine receptors (ARs): A1, A2A, A3, and A2B and, as does adenosine, exerts effects on neurons and glial cells of all brain areas. In consequence, caffeine, when acting as an AR antagonist, is doing the opposite of activation of adenosine receptors due to removal of endogenous adenosinergic tonus. Besides AR antagonism, xanthines, including caffeine, have other biological actions: they inhibit phosphodiesterases (PDEs) (e.g., PDE1, PDE4, PDE5), promote calcium release from intracellular stores, and interfere with GABA-A receptors. Caffeine, through antagonism of ARs, affects brain functions such as sleep, cognition, learning, and memory, and modifies brain dysfunctions and diseases: Alzheimer's disease, Parkinson's disease, Huntington's disease, Epilepsy, Pain/Migraine, Depression, Schizophrenia. In conclusion, targeting approaches that involve ARs will enhance the possibilities to correct brain dysfunctions, via the universally consumed substance that is caffeine.

A functional requirement for astroglia in promoting blood vessel development in the early postnatal brain.

PubMed

Ma, Shang; Kwon, Hyo Jun; Huang, Zhen

2012-01-01

Astroglia are a major cell type in the brain and play a key role in many aspects of brain development and function. In the adult brain, astrocytes are known to intimately ensheath blood vessels and actively coordinate local neural activity and blood flow. During development of the neural retina, blood vessel growth follows a meshwork of astrocytic processes. Several genes have also been implicated in retinal astrocytes for regulating vessel development. This suggests a role of astrocytes in promoting angiogenesis throughout the central nervous system. To determine the roles that astrocytes may play during brain angiogenesis, we employ genetic approaches to inhibit astrogliogenesis during perinatal corticogenesis and examine its effects on brain vessel development. We find that conditional deletion from glial progenitors of orc3, a gene required for DNA replication, dramatically reduces glial progenitor cell number in the subventricular zone and astrocytes in the early postnatal cerebral cortex. This, in turn, results in severe reductions in both the density and branching frequency of cortical blood vessels. Consistent with a delayed growth but not regression of vessels, we find neither significant net decreases in vessel density between different stages after normalizing for cortical expansion nor obvious apoptosis of endothelial cells in these mutants. Furthermore, concomitant with loss of astroglial interactions, we find increased endothelial cell proliferation, enlarged vessel luminal size as well as enhanced cytoskeletal gene expression in pericytes, which suggests compensatory changes in vascular cells. Lastly, we find that blood vessel morphology in mutant cortices recovers substantially at later stages, following astrogliosis. These results thus implicate a functional requirement for astroglia in promoting blood vessel growth during brain development.

Toward the identification of the cardiac cGMP inhibited-phosphodiesterase catalytic site

NASA Astrophysics Data System (ADS)

Fossa, Paola; Boggia, Raffaella; Mosti, Luisa

1998-07-01

Cyclic nucleotide phosphodiesterases (PDEs) comprise a complex group of enzymes; five major PDE families or classes with distinctive properties have been identified. Among these a great deal of interest has recently been focused on the so called cGMP-inhibited low Km cAMP phosphodiesterase (cGI PDE) or PDE III. A number of positive inotropic agents, including the well-known milrinone, display a specific inhibition of PDE III as primary mechanism of action. Recent studies have been carried out to develop a pharmacophore model of the PDE III active site. We therefore performed molecular modelling and 3D-SAR studies so as to better define structural requirements for potent and selective enzymatic inhibition. The DISCO (DIStance COmparison) strategy has been applied on a set of compounds taken from literature and a milrinone analogue previously synthesized by us, all of which are characterized by a marked inotropic effect but with varying degrees of enzyme selectivity. A common pharmacophoric model was derived, validated and considered as starting point to perform a 3D-SAR study using the GRID force field and PCA (Principal Component Analysis) with the aim of rationally designing more selective inhibitors. This paper presents the results of this theoretical approach.

Structural Insight into the Mechanism of c-di-GMP hydrolysis by EAL domain phosphodiesterases.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tchigvintsev, A.; Xu, X.; Singer, A.

2010-08-01

Cyclic diguanylate (or bis-(3'-5') cyclic dimeric guanosine monophosphate; c-di-GMP) is a ubiquitous second messenger that regulates diverse cellular functions, including motility, biofilm formation, cell cycle progression, and virulence in bacteria. In the cell, degradation of c-di-GMP is catalyzed by highly specific EAL domain phosphodiesterases whose catalytic mechanism is still unclear. Here, we purified 13 EAL domain proteins from various organisms and demonstrated that their catalytic activity is associated with the presence of 10 conserved EAL domain residues. The crystal structure of the TBD1265 EAL domain was determined in free state (1.8 {angstrom}) and in complex with c-di-GMP (2.35 {angstrom}), andmore » unveiled the role of conserved residues in substrate binding and catalysis. The structure revealed the presence of two metal ions directly coordinated by six conserved residues, two oxygens of c-di-GMP phosphate, and potential catalytic water molecule. Our results support a two-metal-ion catalytic mechanism of c-di-GMP hydrolysis by EAL domain phosphodiesterases.« less

Gelatin promotes rapid restoration of the blood brain barrier after acute brain injury.

PubMed

Kumosa, Lucas S; Zetterberg, Valdemar; Schouenborg, Jens

2018-01-01

implanted probes, both of which impede implant function. The underlying mechanisms remain to be elucidated, however. Our findings demonstrate for the first time that gelatin has a significant effect on the BBB by promoting rapid restoration of integrity after injury. Moreover, gelatin alters microglia phenotypes and modulates gelatinase activity for up to 2weeks favoring anti-inflammation and restoration of the tissue. Given the key importance of the BBB for normal brain functions, we believe our findings have substantial significance and will be highly interesting to researchers in the biomaterial field. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Passage of Magnetic Tat-Conjugated Fe3O4@SiO2 Nanoparticles Across In Vitro Blood-Brain Barrier

NASA Astrophysics Data System (ADS)

Zhao, Xueqin; Shang, Ting; Zhang, Xiaodan; Ye, Ting; Wang, Dajin; Rei, Lei

2016-10-01

Delivery of diagnostic or therapeutic agents across the blood-brain barrier (BBB) remains a major challenge of brain disease treatment. Magnetic nanoparticles are actively being developed as drug carriers due to magnetic targeting and subsequently reduced off-target effects. In this paper, we developed a magnetic SiO2@Fe3O4 nanoparticle-based carrier bound to cell-penetrating peptide Tat (SiO2@Fe3O4 -Tat) and studied its fates in accessing BBB. SiO2@Fe3O4-Tat nanoparticles (NPs) exhibited suitable magnetism and good biocompatibility. NPs adding to the apical chamber of in vitro BBB model were found in the U251 glioma cells co-cultured at the bottom of the Transwell, indicating that particles passed through the barrier and taken up by glioma cells. Moreover, the synergistic effects of Tat and magnetic field could promote the efficient cellular internalization and the permeability across the barrier. Besides, functionalization with Tat peptide allowed particles to locate into the nucleus of U251 cells than the non-conjugated NPs. These results suggest that SiO2@Fe3O4-Tat NPs could penetrate the BBB through the transcytosis of brain endothelial cells and magnetically mediated dragging. Therefore, SiO2@Fe3O4-Tat NPs could be exploited as a potential drug delivery system for chemotherapy and gene therapy of brain disease.

Alternative promoter usage generates novel shorter MAPT mRNA transcripts in Alzheimer's disease and progressive supranuclear palsy brains.

PubMed

Huin, Vincent; Buée, Luc; Behal, Hélène; Labreuche, Julien; Sablonnière, Bernard; Dhaenens, Claire-Marie

2017-10-03

Alternative promoter usage is an important mechanism for transcriptome diversity and the regulation of gene expression. Indeed, this alternative usage may influence tissue/subcellular specificity, protein translation and function of the proteins. The existence of an alternative promoter for MAPT gene was considered for a long time to explain differential tissue specificity and differential response to transcription and growth factors between mRNA transcripts. The alternative promoter usage could explain partly the different tau proteins expression patterns observed in tauopathies. Here, we report on our discovery of a functional alternative promoter for MAPT, located upstream of the gene's second exon (exon 1). By analyzing genome databases and brain tissue from control individuals and patients with Alzheimer's disease or progressive supranuclear palsy, we identified novel shorter transcripts derived from this alternative promoter. These transcripts are increased in patients' brain tissue as assessed by 5'RACE-PCR and qPCR. We suggest that these new MAPT isoforms can be translated into normal or amino-terminal-truncated tau proteins. We further suggest that activation of MAPT's alternative promoter under pathological conditions leads to the production of truncated proteins, changes in protein localization and function, and thus neurodegeneration.

Active Site Metal Occupancy and Cyclic Di-GMP Phosphodiesterase Activity of Thermotoga maritima HD-GYP.

PubMed

Miner, Kyle D; Kurtz, Donald M

2016-02-16

HD-GYPs make up a subclass of the metal-dependent HD phosphohydrolase superfamily and catalyze conversion of cyclic di(3',5')-guanosine monophosphate (c-di-GMP) to 5'-phosphoguanylyl-(3'→5')-guanosine (pGpG) and GMP. Until now, the only reported crystal structure of an HD-GYP that also exhibits c-di-GMP phosphodiesterase activity contains a His/carboxylate ligated triiron active site. However, other structural and phylogenetic correlations indicate that some HD-GYPs contain dimetal active sites. Here we provide evidence that an HD-GYP c-di-GMP phosphodiesterase, TM0186, from Thermotoga maritima can accommodate both di- and trimetal active sites. We show that an as-isolated iron-containing TM0186 has an oxo/carboxylato-bridged diferric site, and that the reduced (diferrous) form is necessary and sufficient to catalyze conversion of c-di-GMP to pGpG, but that conversion of pGpG to GMP requires more than two metals per active site. Similar c-di-GMP phosphodiesterase activities were obtained with divalent iron or manganese. On the basis of activity correlations with several putative metal ligand residue variants and molecular dynamics simulations, we propose that TM0186 can accommodate both di- and trimetal active sites. Our results also suggest that a Glu residue conserved in a subset of HD-GYPs is required for formation of the trimetal site and can also serve as a labile ligand to the dimetal site. Given the anaerobic growth requirement of T. maritima, we suggest that this HD-GYP can function in vivo with either divalent iron or manganese occupying di- and trimetal sites.

White lupin cluster root acclimation to phosphorus deficiency and root hair development involve unique glycerophosphodiester phosphodiesterases

USDA-ARS?s Scientific Manuscript database

White lupin (Lupinus albus L.) is a phosphate (Pi) deficiency tolerant legume which develops short, densely clustered tertiary lateral roots (cluster/proteoid roots) in response to Pi limitation. In this report we characterize two glycerophosphodiester phosphodiesterase (GPX-PDE) genes (GPX-PDE1 and...

Phosphodiesterase type 5 inhibitor abuse: a critical review.

PubMed

Lowe, Gregory; Costabile, Raymond

2011-06-01

Abuse of sildenafil has been reported since its introduction in 1999 and commonly documented in combination with illicit drugs among men and women of all ages. Increased risks of sexually transmissible diseases including HIV have been associated with sildenafil use in men who have sex with men. Recognizing the abuse potential of phosphodiesterase type 5 inhibitors (PDE5), we aim to summarize the current knowledge of this abuse. An investigation of EMBASE, PubMed, the Food and Drug Administration (FDA) website, MedWatch, and search engines was performed to evaluate information regarding sildenafil, tadalafil, and vardenafil abuse. The EMBASE search provided 46 articles fitting the search criteria and evaluation led to 21 separate publications with specific information regarding PDE5 abuse. A PubMed search found 10 additional publications. MedWatch reported 44 separate warnings since 2000, most of which reported contamination of herbal products with active drug components. Few reports of abuse were among the 14,818 reports in the FDA AERS for sildenafil. A search for "internet drug store" revealed 6.4 million hits and of 7000 internet pharmacies identified by the Verified Internet Pharmacy Practice Sites Program (VIPPS) only 4% were in proper compliance. The role internet pharmacies play in counterfeit PDE5 or abuse is not well documented; however based on easy access, direct patient marketing, and low advertised cost it is likely this role is underreported. Currently the best recommendation for providers is to recognize the possibility of abuse and to educate patients on risks of this behavior.

Magnetic resonance spectroscopy reveals oral Lactobacillus promotion of increases in brain GABA, N-acetyl aspartate and glutamate.

PubMed

Janik, Rafal; Thomason, Lynsie A M; Stanisz, Andrew M; Forsythe, Paul; Bienenstock, John; Stanisz, Greg J

2016-01-15

The gut microbiome has been shown to regulate the development and functions of the enteric and central nervous systems. Its involvement in the regulation of behavior has attracted particular attention because of its potential translational importance in clinical disorders, however little is known about the pathways involved. We previously have demonstrated that administration of Lactobacillus rhamnosus (JB-1) to healthy male BALB/c mice, promotes consistent changes in GABA-A and -B receptor sub-types in specific brain regions, accompanied by reductions in anxiety and depression-related behaviors. In the present study, using magnetic resonance spectroscopy (MRS), we quantitatively assessed two clinically validated biomarkers of brain activity and function, glutamate+glutamine (Glx) and total N-acetyl aspartate+N-acetyl aspartyl glutamic acid (tNAA), as well as GABA, the chief brain inhibitory neurotransmitter. Mice received 1×10(9) cfu of JB-1 per day for 4weeks and were subjected to MRS weekly and again 4weeks after cessation of treatment to ascertain temporal changes in these neurometabolites. Baseline concentrations for Glx, tNAA and GABA were equal to 10.4±0.3mM, 8.7±0.1mM, and 1.2±0.1mM, respectively. Delayed increases were first seen for Glx (~10%) and NAA (~37%) at 2weeks which persisted only to the end of treatment. However, Glx was still elevated 4weeks after treatment had ceased. Significantly elevated GABA (~25%) was only seen at 4weeks. These results suggest specific metabolic pathways in our pursuit of mechanisms of action of psychoactive bacteria. They also offer through application of standard clinical neurodiagnostic techniques, translational opportunities to assess biomarkers accompanying behavioral changes induced by alterations in the gut microbiome. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Quercetin acutely relaxes airway smooth muscle and potentiates β-agonist-induced relaxation via dual phosphodiesterase inhibition of PLCβ and PDE4

PubMed Central

Emala, Charles W.

2013-01-01

Asthma is a disease of the airways with symptoms including exaggerated airway narrowing and airway inflammation. Early asthma therapies used methylxanthines to relieve symptoms, in part, by inhibiting cyclic nucleotide phosphodiesterases (PDEs), the enzyme responsible for degrading cAMP. The classification of tissue-specific PDE subtypes and the clinical introduction of PDE-selective inhibitors for chronic obstructive pulmonary disease (i.e., roflumilast) have reopened the possibility of using PDE inhibition in the treatment of asthma. Quercetin is a naturally derived PDE4-selective inhibitor found in fruits, vegetables, and tea. We hypothesized that quercetin relaxes airway smooth muscle via cAMP-mediated pathways and augments β-agonist relaxation. Tracheal rings from male A/J mice were mounted in myographs and contracted with acetylcholine (ACh). Addition of quercetin (100 nM-1 mM) acutely and concentration-dependently relaxed airway rings precontracted with ACh. In separate studies, pretreatment with quercetin (100 μM) prevented force generation upon exposure to ACh. In additional studies, quercetin (50 μM) significantly potentiated isoproterenol-induced relaxations. In in vitro assays, quercetin directly attenuated phospholipase C activity, decreased inositol phosphate synthesis, and decreased intracellular calcium responses to Gq-coupled agonists (histamine or bradykinin). Finally, nebulization of quercetin (100 μM) in an in vivo model of airway responsiveness significantly attenuated methacholine-induced increases in airway resistance. These novel data show that the natural PDE4-selective inhibitor quercetin may provide therapeutic relief of asthma symptoms and decrease reliance on short-acting β-agonists. PMID:23873842

Effect of the selective phosphodiesterase type 5 inhibitor sildenafil on erectile dysfunction in the anesthetized dog.

PubMed

Carter, A J; Ballard, S A; Naylor, A M

1998-07-01

The effects of sildenafil, a highly selective inhibitor of cyclic guanosine monophosphate-specific phosphodiesterase type 5, on erectile function in the anesthetized dog were evaluated. In pentobarbital-anesthetized dogs, increases in intracavernosal pressure in the corpus cavernosum and penile blood flow were induced by pelvic nerve stimulation over a frequency range of 1 to 16 hertz. The effects of increasing doses of sildenafil on electrically stimulated intracavernosal pressure, penile blood flow, blood pressure, and heart-rate were evaluated. In parallel experiments, the effects of the nitric oxide synthase inhibitor N omega-Nitro-L-Arginine (L-NOArg) on these same parameters also were assessed. The effects of nerve stimulation on intracavernosal pressure and blood flow to the penis were blocked by L-NOArg, 0.1-3 mg./kg., in a dose-related manner, confirming the important role of nitric oxide in producing erections. Sildenafil, 1-100 microg./kg administered intravenously, had no direct effect on intracavernosal pressure but potentiated the increase in intracavernosal pressure induced by nerve stimulation. This potentiation occurred at sildenafil plasma concentrations consistent with its relaxation effect on isolated human cavernosal tissue and its inhibition of phosphodiesterase type 5 in vitro. Sildenafil had no significant effect on blood pressure or heart rate. By inhibiting cyclic guanosine monophosphate-specific phosphodiesterase type 5, sildenafil augments the neuronal mechanism responsible for penile erection. This mechanism explains the significant improvements reported in the rigidity and duration of erections seen in patients with erectile dysfunction who have been treated with oral sildenafil.

Perceptions of erectile dysfunction and phosphodiesterase type 5 inhibitor therapy in a qualitative study of men and women in affected relationships.

PubMed

McGraw, Sarah A; Rosen, Raymond C; Althof, Stanley E; Dunn, Marian; Cameron, Ann; Wong, David

2015-01-01

Erectile dysfunction negatively affects men and women in relationships; however, the subjective experience of erectile dysfunction and phosphodiesterase-type 5 inhibitor therapy remains poorly understood. The authors therefore characterized participants' subjective understanding of erectile dysfunction and phosphodiesterase-type 5 inhibitor therapy using individual interviews with affected heterosexual men (n = 58) and women (n = 65). Responses were characterized by 6 psychosocial domains: explanation of the experience, emotional responses, socially expected responses, value of sex, communication with the partner, and treatment expectations. The findings may aid clinicians in relating to men with erectile dysfunction and thus potentially improve effectiveness of therapy.

Genetics Home Reference: COL4A1-related brain small-vessel disease

MedlinePlus

... COL4A1-related brain small-vessel disease COL4A1-related brain small-vessel disease Printable PDF Open All Close ... view the expand/collapse boxes. Description COL4A1 -related brain small-vessel disease is part of a group ...

The devil is in the details: an analysis of the subtleties between phosphodiesterase inhibitors for erectile dysfunction.

PubMed

Smith-Harrison, L I; Patel, Abhishek; Smith, Ryan P

2016-04-01

Erectile dysfunction (ED) is a common sexual disorder with numerous etiologies involving multiple organ systems that leads to significant distress and decreased quality of life for the affected men. Fortunately, there are several modalities and interventions for treating ED. Oral medications, intra-urethral compounds, intracorporeal injections, vacuum-assist devices and surgically implanted prostheses are all part of the treatment algorithm. One of the first-lines and certainly the most widely used options for treating ED is the family of oral phosphodiesterase type 5 inhibitors (PDE5I). The introduction of these medications in the late 1990s revolutionized the field of sexual medicine. Currently there are no guidelines and minimal literature to help providers choose among drugs in this class. This review will address differences in efficacy and side effects between various members of the oral selective phosphodiesterase-5 inhibitor class of drugs.

T cell–derived interleukin (IL)-21 promotes brain injury following stroke in mice

PubMed Central

Clarkson, Benjamin D.S.; Ling, Changying; Shi, Yejie; Harris, Melissa G.; Rayasam, Aditya; Sun, Dandan; Salamat, M. Shahriar; Kuchroo, Vijay; Lambris, John D.; Sandor, Matyas

2014-01-01

T lymphocytes are key contributors to the acute phase of cerebral ischemia reperfusion injury, but the relevant T cell–derived mediators of tissue injury remain unknown. Using a mouse model of transient focal brain ischemia, we report that IL-21 is highly up-regulated in the injured mouse brain after cerebral ischemia. IL-21–deficient mice have smaller infarcts, improved neurological function, and reduced lymphocyte accumulation in the brain within 24 h of reperfusion. Intracellular cytokine staining and adoptive transfer experiments revealed that brain-infiltrating CD4+ T cells are the predominant IL-21 source. Mice treated with decoy IL-21 receptor Fc fusion protein are protected from reperfusion injury. In postmortem human brain tissue, IL-21 localized to perivascular CD4+ T cells in the area surrounding acute stroke lesions, suggesting that IL-21–mediated brain injury may be relevant to human stroke. PMID:24616379

Lower urinary tract symptoms/benign prostatic hypertrophy and vascular function: Role of the nitric oxide-phosphodiesterase type 5-cyclic guanosine 3',5'-monophosphate pathway.

PubMed

Higashi, Yukihito

2017-06-01

It is well known that there is an association of lower urinary tract symptoms/benign prostatic hypertrophy with cardiovascular disease, suggesting that lower urinary tract symptoms/benign prostatic hypertrophy is a risk factor for cardiovascular events. Vascular function, including endothelial function and vascular smooth muscle function, is involved in the pathogenesis, maintenance and development of atherosclerosis, leading to cardiovascular events. Vascular dysfunction per se should also contribute to lower urinary tract symptoms/benign prostatic hypertrophy. Both lower urinary tract symptoms/benign prostatic hypertrophy and vascular dysfunction have cardiovascular risk factors, such as hypertension, dyslipidemia, diabetes mellitus, aging, obesity and smoking. Inactivation of the phosphodiesterase type 5-cyclic guanosine 3',5'-monophosphate-nitric oxide pathway causes lower urinary tract symptoms/benign prostatic hypertrophy through an enhancement of sympathetic nervous activity, endothelial dysfunction, increase in Rho-associated kinase activity and vasoconstriction, and decrease in blood flow of pelvic viscera. Both endogenous nitric oxide and exogenous nitric oxide act as vasodilators on vascular smooth muscle cells through an increase in the content of cyclic guanosine 3',5'-monophosphate, which is inactivated by phosphodiesterase type 5. In a clinical setting, phosphodiesterase type 5 inhibitors are widely used in patients with lower urinary tract symptoms/benign prostatic hypertrophy. Phosphodiesterase type 5 inhibitors might have beneficial effects on vascular function through not only inhibition of cyclic guanosine 3',5'-monophosphate degradation, but also increases in testosterone levels and nitric oxide bioavailability, increase in the number and improvement of the function of endothelial progenitor cells, and decrease in insulin resistance. In the present review, the relationships between lower urinary tract symptoms/benign prostatic hypertrophy, the

Caregivers' support needs and factors promoting resiliency after brain injury.

PubMed

Kitter, Bryony; Sharman, Rachael

2015-01-01

This article explores the challenges, support needs and coping strategies of caregivers of people with an acquired brain injury (ABI). Semi-structured interviews were conducted with caregivers (n = 20) to explore their support services received, access barriers, utility of services, needed supports, coping strategies and factors promoting life satisfaction. The team recorded, transcribed verbatim and inductively analysed all interviews. Through thematic data analysis, three central themes were revealed: (a) barriers impeding quality-of-life, (b) support needed to improve quality-of-life and (c) factors enabling quality-of-life. All perspectives from the participants involved are synthesized to provide a rich depiction of caregivers' support needs and coping strategies. Two specific findings of interest include a negative association between severity of brain injury and caregiver's desire to direct treatment, as well as a distinct service gap in assistance for caregivers who are caring for someone with violent/offending behaviours. This study recommends short- and long-term changes, given Australia's upcoming National Disability Insurance Scheme, to increase caregiver quality-of-life, which will ultimately affect the rehabilitation outcomes of persons with ABI.

Nuclear uptake of an amino-terminal fragment of apolipoprotein E4 promotes cell death and localizes within microglia of the Alzheimer's disease brain.

PubMed

Love, Julia E; Day, Ryan J; Gause, Justin W; Brown, Raquel J; Pu, Xinzhu; Theis, Dustin I; Caraway, Chad A; Poon, Wayne W; Rahman, Abir A; Morrison, Brad E; Rohn, Troy T

2017-01-01

Although harboring the apolipoprotein E4 ( APOE4 ) allele is a well known risk factor in Alzheimer's disease (AD), the mechanism by which it contributes to disease risk remains elusive. To investigate the role of proteolysis of apoE4 as a potential mechanism, we designed and characterized a site-directed cleavage antibody directed at position D151 of the mature form of apoE4 and E3. Characterization of this antibody indicated a high specificity for detecting synthesized recombinant proteins corresponding to the amino acid sequences 1-151 of apoE3 and E4 that would generate the 17 kDa (p17) fragment. In addition, this antibody also detected a ~17 kDa amino-terminal fragment of apoE4 following incubation with collagenase and matrix metalloproteinase-9 (MMP-9), but did not react with full-length apoE4. Application of this amino-terminal apoE cleavage-fragment (nApoECFp17) antibody, revealed nuclear labeling within glial cells and labeling of a subset of neurofibrillary tangles in the human AD brain. A quantitative analysis indicated that roughly 80% of labeled nuclei were microglia. To confirm these findings, cultured BV2 microglia cells were incubated with the amino-terminal fragment of apoE4 corresponding to the cleavage site at D151. The results indicated efficient uptake of this fragment and trafficking to the nucleus that also resulted in significant cell death. In contrast, a similarly designed apoE3 fragment showed no toxicity and primarily localized within the cytoplasm. These data suggest a novel cleavage event by which apoE4 is cleaved by the extracellular proteases, collagenase and MMP-9, generating an amino-terminal fragment that is then taken up by microglia, traffics to the nucleus and promotes cell death. Collectively, these findings provide important mechanistic insights into the mechanism by which harboring the APOE4 allele may elevate dementia risk observed in AD.

Brain Aquaporin-4 in Experimental Acute Liver Failure

PubMed Central

Rama Rao, Kakulavarapu V.; Jayakumar, Arumugam R.; Tong, Xiaoying; Curtis, Kevin M.; Norenberg, Michael D.

2016-01-01

Intracranial hypertension due to brain edema and associated astrocyte swelling is a potentially lethal complication of acute liver failure (ALF). Mechanisms of edema formation are not well understood but elevated levels of blood and brain ammonia and its byproduct glutamine have been implicated in this process. We examined mRNA and protein expression of the water channel protein aquaporin-4 (AQP4) in cerebral cortex in a rat model of ALF induced by the hepatotoxin thioacetamide. Rats with ALF showed increased AQP4 protein in the plasma membrane (PM). Total tissue levels of AQP4 protein and mRNA levels were not altered indicating that increased AQP4 is not transcriptionally mediated but is likely due to a conformational change in the protein, i.e. a more stable anchoring of AQP4 to the PM and/or interference with its degradation. By immunohistochemistry there was an increase in AQP4 immunoreactivity in the PM of perivascular astrocytes in ALF. Rats with ALF showed increased levels of α-syntrophin, a protein involved in the anchoring of AQP4 to perivascular astrocytic end-feet. Increased AQP4 and α-syntrophin levels were inhibited by L-histidine, an inhibitor of glutamine transport into mitochondria, suggesting a role for glutamine in the increase of PM levels of AQP4. These results indicate that increased AQP4 PM levels in perivascular astrocytic end-feet are likely critical to the development of brain edema in ALF. PMID:20720509

4 CFR 3.1 - Appointment, promotion, and assignment.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 4 Accounts 1 2010-01-01 2010-01-01 false Appointment, promotion, and assignment. 3.1 Section 3.1 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM EMPLOYMENT § 3.1 Appointment, promotion, and assignment. Employees of GAO shall be appointed, promoted and assigned solely on the basis of merit and...

Tilapia Hepcidin 2-3 Peptide Modulates Lipopolysaccharide-induced Cytokines and Inhibits Tumor Necrosis Factor-α through Cyclooxygenase-2 and Phosphodiesterase 4D*

PubMed Central

Rajanbabu, Venugopal; Pan, Chieh-Yu; Lee, Shang-Chun; Lin, Wei-Ju; Lin, Ching-Chun; Li, Chung-Leung; Chen, Jyh-Yih

2010-01-01

The antimicrobial peptide, tilapia hepcidin (TH) 2-3, belongs to the hepcidin family, and its antibacterial function has been reported. Here, we examined the TH2-3-mediated regulation of proinflammatory cytokines in bacterial endotoxin lipopolysaccharide (LPS)-stimulated mouse macrophages. The presence of TH2-3 in LPS-stimulated cells reduced the amount of tumor necrosis factor (TNF)-α secretion. From a microarray, real-time polymerase chain reaction (PCR), and cytokine array studies, we showed down-regulation of the proinflammatory cytokines TNF-α, interleukin (IL)-1α, IL-1β, IL-6, and the prostaglandin synthesis gene, cyclooxygenase (COX)-2, by TH2-3. Studies with the COX-2-specific inhibitor, melaxicam, and with COX-2-overexpressing cells demonstrated the positive regulation of TNF-α and negative regulation of cAMP degradation-specific phosphodiesterase (PDE) 4D by COX-2. In LPS-stimulated cells, TH2-3 acts like melaxicam and down-regulates COX-2 and up-regulates PDE4D. The reduction in intracellular cAMP by TH2-3 or melaxicam in LPS-stimulated cells supports the negative regulation of PDE4D by COX-2 and TH2-3. This demonstrates that the inhibition of COX-2 is among the mechanisms through which TH2-3 controls TNF-α release. At 1 h after treatment, the presence of TH2-3 in LPS-stimulated cells had suppressed the induction of pERK1/2 and prevented the LPS-stimulated nuclear accumulation of NF-κB family proteins of p65, NF-κB2, and c-Rel. In conclusion, TH2-3 inhibits TNF-α and other proinflammatory cytokines through COX-2-, PDE4D-, and pERK1/2-dependent mechanisms. PMID:20675368

Protective role of brain water channel AQP4 in murine cerebral malaria

PubMed Central

Promeneur, Dominique; Lunde, Lisa Kristina; Amiry-Moghaddam, Mahmood; Agre, Peter

2013-01-01

Tragically common among children in sub-Saharan Africa, cerebral malaria is characterized by rapid progression to coma and death. In this study, we used a model of cerebral malaria appearing in C57BL/6 WT mice after infection with the rodent malaria parasite Plasmodium berghei ANKA. Expression and cellular localization of the brain water channel aquaporin-4 (AQP4) was investigated during the neurological syndrome. Semiquantitative real-time PCR comparing uninfected and infected mice showed a reduction of brain AQP4 transcript in cerebral malaria, and immunoblots revealed reduction of brain AQP4 protein. Reduction of brain AQP4 protein was confirmed in cerebral malaria by quantitative immunogold EM; however, polarized distribution of AQP4 at the perivascular and subpial astrocyte membranes was not altered. To further examine the role of AQP4 in cerebral malaria, WT mice and littermates genetically deficient in AQP4 were infected with P. berghei. Upon development of cerebral malaria, WT and AQP4-null mice exhibited similar increases in width of perivascular astroglial end-feet in brain. Nevertheless, the AQP4-null mice exhibited more severe signs of cerebral malaria with greater brain edema, although disruption of the blood–brain barrier was similar in both groups. In longitudinal studies, cerebral malaria appeared nearly 1 d earlier in the AQP4-null mice, and reduced survival was noted when chloroquine rescue was attempted. We conclude that the water channel AQP4 confers partial protection against cerebral malaria. PMID:23277579

The Cyclic Di-GMP Phosphodiesterase Gene Rv1357c/BCG1419c Affects BCG Pellicle Production and In Vivo Maintenance.

PubMed

Flores-Valdez, Mario Alberto; Aceves-Sánchez, Michel de Jesús; Pedroza-Roldán, César; Vega-Domínguez, Perla Jazmín; Prado-Montes de Oca, Ernesto; Bravo-Madrigal, Jorge; Laval, Françoise; Daffé, Mamadou; Koestler, Ben; Waters, Christopher M

2015-02-01

Bacteria living in a surface-attached community that contains a heterogeneous population, coated with an extracellular matrix, and showing drug tolerance (biofilms) are often linked to chronic infections. In mycobacteria, the pellicle mode of growth has been equated to an in vitro biofilm and meets several of the criteria mentioned above, while tuberculosis infection presents a chronic (latent) phase of infection. As mycobacteria lack most genes required to control biofilm production by other microorganisms, we deleted or expressed from the hsp60 strong promoter the only known c-di-GMP phosphodiesterase (PDE) gene in Mycobacterium bovis BCG. We found changes in pellicle production, cellular protein profiles, lipid production, resistance to nitrosative stress and maintenance in lungs and spleens of immunocompetent BALB/mice. Our results show that pellicle production and capacity to remain within the host are linked in BCG. © 2015 International Union of Biochemistry and Molecular Biology.

Phosphodiesterase Type 5 Inhibitors, Sport and Doping.

PubMed

Di Luigi, Luigi; Sansone, Massimiliano; Sansone, Andrea; Ceci, Roberta; Duranti, Guglielmo; Borrione, Paolo; Crescioli, Clara; Sgrò, Paolo; Sabatini, Stefania

Phosphodiesterase type 5 inhibitors (PDE5i) (e.g., sildenafil, tadalafil, vardenafil, and avanafil) are drugs commonly used to treat erectile dysfunction, pulmonary arterial hypertension, and benign prostatic hyperplasia. PDE5i are not prohibited by the World Anti-Doping Agency (WADA) but are alleged to be frequently misused by healthy athletes to improve sporting performance. In vitro and in vivo studies have reported various effects of PDE5i on cardiovascular, muscular, metabolic, and neuroendocrine systems and the potential, therefore, to enhance performance of healthy athletes during training and competition. This suggests well-controlled research studies to examine the ergogenic effects of PDE5i on performance during activities that simulate real sporting situations are warranted to determine if PDE5i should be included on the prohibited WADA list. In the meantime, there is concern that some otherwise healthy athletes will continue to misuse PDE5i to gain an unfair competitive advantage over their competitors.

Pho4 Is Essential for Dissemination of Cryptococcus neoformans to the Host Brain by Promoting Phosphate Uptake and Growth at Alkaline pH

PubMed Central

Kaufman-Francis, Keren; Desmarini, Desmarini; Juillard, Pierre G.; Li, Cecilia; Stifter, Sebastian A.; Feng, Carl G.; Sorrell, Tania C.; Grau, Georges E. R.; Bahn, Yong-Sun

2017-01-01

ABSTRACT Phosphate acquisition by fungi is regulated by the phosphate-sensing and acquisition (PHO) signaling pathway. Cryptococcus neoformans disseminates from the lung to the brain and is the commonest cause of fungal meningitis worldwide. To investigate the contribution of PHO signaling to cryptococcal dissemination, we characterized a transcription factor knockout strain (hlh3Δ/pho4Δ) defective in phosphate acquisition. Despite little similarity with other fungal Pho4 proteins, Hlh3/Pho4 functioned like a typical phosphate-responsive transcription factor in phosphate-deprived cryptococci, accumulating in nuclei and triggering expression of genes involved in phosphate acquisition. The pho4Δ mutant strain was susceptible to a number of stresses, the effect of which, except for alkaline pH, was alleviated by phosphate supplementation. Even in the presence of phosphate, the PHO pathway was activated in wild-type cryptococci at or above physiological pH, and under these conditions, the pho4Δ mutant had a growth defect and compromised phosphate uptake. The pho4Δ mutant was hypovirulent in a mouse inhalation model, where dissemination to the brain was reduced dramatically, and markedly hypovirulent in an intravenous dissemination model. The pho4Δ mutant was not detected in blood, nor did it proliferate significantly when cultured with peripheral blood monocytes. In conclusion, dissemination of infection and the pathogenesis of meningitis are dependent on cryptococcal phosphate uptake and stress tolerance at alkaline pH, both of which are Pho4 dependent. IMPORTANCE Cryptococcal meningitis is fatal without treatment and responsible for more than 500,000 deaths annually. To be a successful pathogen, C. neoformans must obtain an adequate supply of essential nutrients, including phosphate, from various host niches. Phosphate acquisition in fungi is regulated by the PHO signaling cascade, which is activated when intracellular phosphate decreases below a critical

Amyloid β-induced impairments on mitochondrial dynamics, hippocampal neurogenesis, and memory are restored by phosphodiesterase 7 inhibition.

PubMed

Bartolome, Fernando; de la Cueva, Macarena; Pascual, Consuelo; Antequera, Desiree; Fernandez, Tamara; Gil, Carmen; Martinez, Ana; Carro, Eva

2018-02-20

The phosphodiesterase (PDE) 7 inhibitor S14 is a cell-permeable small heterocyclic molecule that is able to cross the blood-brain barrier. We previously found that intraperitoneal treatment with S14 exerted neuroprotection in an Alzheimer's disease (AD) model (in APP/PS1 mice). The objective of this study was to investigate the neurogenic and cellular effects of oral administration of S14 on amyloid β (Aβ) overload. We orally administered the PDE7 inhibitor S14 (15 mg/kg/day) or vehicle in 6-month-old APP/PS1 mice. After 5 weeks of S14 treatment, we evaluated cognitive functions and brain tissues. We also assessed the effects of S14 on the Aβ-treated human neuroblastome SH-SY5Y cell line. Targeting the cyclic adenosine monophosphate (cAMP)/cAMP-response element binding protein (CREB) pathway, S14 rescued cognitive decline by improving hippocampal neurogenesis in APP/PS1 transgenic mice. Additionally, S14 treatment reverted the Aβ-induced reduction in mitochondrial mass in APP/PS1 mice and in the human neuroblastoma SH-SY5Y cells co-exposed to Aβ. The restoration of the mitochondrial mass was found to be a dual effect of S14: a rescue of the mitochondrial biogenesis formerly slowed down by Aβ overload, and a reduction in the Aβ-increased mitochondrial clearance mechanism of mitophagy. Here, we show new therapeutic effects of the PDE7 inhibitor, confirming S14 as a potential therapeutic drug for AD.

The effects of a novel phosphodiesterase 7A and -4 dual inhibitor, YM-393059, on T-cell-related cytokine production in vitro and in vivo.

PubMed

Yamamoto, Satoshi; Sugahara, Shingo; Naito, Ryo; Ichikawa, Atsushi; Ikeda, Ken; Yamada, Toshimitsu; Shimizu, Yasuaki

2006-07-10

YM-393059, (+/-)-N-(4,6-dimethylpyrimidin-2-yl)-4-[2-(4-methoxy-3-methylphenyl)-5-(4-methylpiperazin-1-yl)-4,5,6,7-tetrahydro-1H-indol-1-yl]benzenesulfonamide difumarate, is a novel phosphodiesterase (PDE) inhibitor that inhibited the PDE7A isoenzyme with a high potency (IC50=14 nM) and PDE4 with a moderate potency (IC50=630 nM). In a cell-based assay, YM-393059 was found to inhibit anti-CD3 antibody, Staphylococcal enterotoxin B, and phytohaemagglutinin-induced interleukin (IL)-2 production in mouse splenocytes with IC50 values ranging from 0.48 to 1.1 microM. It also inhibited anti-CD3 antibody-induced interferon (IFN)-gamma and IL-4 production in splenocytes with IC50 values of 1.8 and 2.8 microM, respectively. YM-393059's inhibition of anti-CD3 antibody-stimulated cytokine (IL-2, IFN-gamma, and IL-4) production was 20- to 31-fold weaker than that of YM976, a selective PDE4 inhibitor. However, orally administered YM-393059 and YM976 inhibited anti-CD3 antibody-induced IL-2 production equipotently in mice. In addition, YM-393059 inhibited lipopolysaccharide-induced tumor necrosis factor-alpha production in vivo more potently than IL-2 (ED50 values of 2.1 mg/kg and 74 mg/kg). In contrast to YM976, YM-393059 did not shorten the duration of alpha2-adrenoceptor agonist-induced sleep in mice, which is a model for the assessment of the typical side effects caused by PDE4 inhibitors, nausea and emesis. YM-393059 is a novel and attractive compound for the treatment of a wide variety of T-cell-mediated diseases.

One step N-glycosylation by filamentous fungi biofilm in bioreactor of a new phosphodiesterase-3 inhibitor tetrazole.

PubMed

de Melo Souza, Paula L; Arruda, Evilanna L; Pazini, Francine; Menegatti, Ricardo; Vaz, Boniek G; Lião, Luciano M; de Oliveira, Valéria

2016-07-01

An efficient and rapid process for N-glycosylation of 5-(1-(3-fluorophenyl)-1H-pyrazol-4-yl)-2H-tetrazole-LQFM 021 (1), a new synthetic derivative of pyrazole with phosphodiesterase-3 (PDE-3) inhibitory action, vasorelaxant activity and low toxicity catalyzed by filamentous fungi biofilm in bioreactor was successfully developed. A maximum N-glycosyl yield of 68% was obtained with Cunninghamella echinulata ATCC 9244 biofilm in bioreactor with conditions of 25mgml(-1) of 1 in PDSM medium at 28°C for 96h. After extraction with ethyl acetate, the derivative was identified by Ultrahigh Resolution Mass Spectrometry and (1)H-(13)C HSQC/HMBC. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nitric oxide-induced changes in endothelial expression of phosphodiesterases 2, 3, and 5.

PubMed

Schankin, Christoph J; Kruse, Lars S; Reinisch, Veronika M; Jungmann, Steffen; Kristensen, Julie C; Grau, Stefan; Ferrari, Uta; Sinicina, Inga; Goldbrunner, Roland; Straube, Andreas; Kruuse, Christina

2010-03-01

To investigate nitric oxide (NO)-mediated changes in expression of cyclic nucleotide degrading phosphodiesterases 2A (PDE2A), PDE3B, and PDE5A in human endothelial cells. Nitric oxide induces production of cyclic guanosine monophosphate (cGMP), which along with cyclic adenosine monophosphate (cAMP) is degraded by PDEs. NO donors and selective inhibitors of PDE3 and PDE5 induce migraine-like headache and play a role in endothelial dysfunction during stroke. The current study investigates possible NO modulation of cGMP-related PDEs relevant to headache induction in a cell line containing such PDEs. Real time polymerase chain reaction and Western blots were used to show expression of PDE2A, PDE3B, and PDE5A in a stable cell line of human brain microvascular endothelial cells. Effects of NO on PDE expression were analyzed at specific time intervals after continued DETA NONOate administration. This study shows the expression of PDE2A, PDE3B, and PDE5A mRNA and PDE3B and PDE5A protein in human cerebral endothelial cells. Long-term DETA NONOate administration induced an immediate mRNA up-regulation of PDE5A (1.9-fold, 0.5 hour), an early peak of PDE2A (1.4-fold, 1 and 2 hours) and later up-regulation of both PDE3B (1.6-fold, 4 hours) and PDE2A (1.7-fold, 8 hours and 1.2-fold after 24 hours). Such changes were, however, not translated into significant changes in protein expression indicating few, if any, functional effects. Long-term NO stimulation modulated PDE3 and PDE5 mRNA expression in endothelial cells. However, PDE3 and PDE5 protein levels were unaffected by NO. The presence of PDE3 or PDE5 in endothelial cells indicates that selective inhibitors may have functional effects in such cells. A complex interaction of cGMP and cAMP in response to NO administration may take place if the mRNA translates into active protein. Whether or not this plays a role in the headache mechanisms remains to be investigated.

Cyclophilin D Promotes Brain Mitochondrial F1FO ATP Synthase Dysfunction in Aging Mice

PubMed Central

Gauba, Esha; Guo, Lan; Du, Heng

2017-01-01

Brain aging is the known strongest risk factor for Alzheimer’s disease (AD). In recent years, mitochondrial deficits have been proposed to be a common mechanism linking brain aging to AD. Therefore, to elucidate the causative mechanisms of mitochondrial dysfunction in aging brains is of paramount importance for our understanding of the pathogenesis of AD, in particular its sporadic form. Cyclophilin D (CypD) is a specific mitochondrial protein. Recent studies have shown that F1FO ATP synthase oligomycin sensitivity conferring protein (OSCP) is a binding partner of CypD. The interaction of CypD with OSCP modulates F1FO ATP synthase function and mediates mitochondrial permeability transition pore (mPTP) opening. Here, we have found that increased CypD expression, enhanced CypD/OSCP interaction, and selective loss of OSCP are prominent brain mitochondrial changes in aging mice. Along with these changes, brain mitochondria from the aging mice demonstrated decreased F1FO ATP synthase activity and defective F1FO complex coupling. In contrast, CypD deficient mice exhibited substantially mitigated brain mitochondrial F1FO ATP synthase dysfunction with relatively preserved mitochondrial function during aging. Interestingly, the aging-related OSCP loss was also dramatically attenuated by CypD depletion. Therefore, the simplest interpretation of this study is that CypD promotes F1FO ATP synthase dysfunction and the resultant mitochondrial deficits in aging brains. In addition, in view of CypD and F1FO ATP synthase alterations seen in AD brains, the results further suggest that CypD-mediated F1FO ATP synthase deregulation is a shared mechanism linking mitochondrial deficits in brain aging and AD. PMID:27834780

Cyclophilin D Promotes Brain Mitochondrial F1FO ATP Synthase Dysfunction in Aging Mice.

PubMed

Gauba, Esha; Guo, Lan; Du, Heng

2017-01-01

Brain aging is the known strongest risk factor for Alzheimer's disease (AD). In recent years, mitochondrial deficits have been proposed to be a common mechanism linking brain aging to AD. Therefore, to elucidate the causative mechanisms of mitochondrial dysfunction in aging brains is of paramount importance for our understanding of the pathogenesis of AD, in particular its sporadic form. Cyclophilin D (CypD) is a specific mitochondrial protein. Recent studies have shown that F1FO ATP synthase oligomycin sensitivity conferring protein (OSCP) is a binding partner of CypD. The interaction of CypD with OSCP modulates F1FO ATP synthase function and mediates mitochondrial permeability transition pore (mPTP) opening. Here, we have found that increased CypD expression, enhanced CypD/OSCP interaction, and selective loss of OSCP are prominent brain mitochondrial changes in aging mice. Along with these changes, brain mitochondria from the aging mice demonstrated decreased F1FO ATP synthase activity and defective F1FO complex coupling. In contrast, CypD deficient mice exhibited substantially mitigated brain mitochondrial F1FO ATP synthase dysfunction with relatively preserved mitochondrial function during aging. Interestingly, the aging-related OSCP loss was also dramatically attenuated by CypD depletion. Therefore, the simplest interpretation of this study is that CypD promotes F1FO ATP synthase dysfunction and the resultant mitochondrial deficits in aging brains. In addition, in view of CypD and F1FO ATP synthase alterations seen in AD brains, the results further suggest that CypD-mediated F1FO ATP synthase deregulation is a shared mechanism linking mitochondrial deficits in brain aging and AD.

Nox4 NADPH oxidase-derived reactive oxygen species, via endogenous carbon monoxide, promote survival of brain endothelial cells during TNF-α-induced apoptosis

PubMed Central

Basuroy, Shyamali; Tcheranova, Dilyara; Bhattacharya, Sujoy; Leffler, Charles W.

2011-01-01

We investigated the role of reactive oxygen species (ROS) in promoting cell survival during oxidative stress induced by the inflammatory mediator tumor necrosis factor-α (TNF-α) in cerebral microvascular endothelial cells (CMVEC) from newborn piglets. Nox4 is the major isoform of NADPH oxidase responsible for TNF-α-induced oxidative stress and apoptosis in CMVEC. We present novel data that Nox4 NADPH oxidase-derived ROS also initiate a cell survival mechanism by increasing production of a gaseous antioxidant mediator carbon monoxide (CO) by constitutive heme oxygenase-2 (HO-2). TNF-α rapidly enhanced endogenous CO production in a superoxide- and NADPH oxidase-dependent manner in CMVEC with innate, but not with small interfering RNA (siRNA)-downregulated Nox4 activity. CORM-A1, a CO-releasing compound, inhibited Nox4-mediated ROS production and enhanced cell survival in TNF-α-challenged CMVEC. The ROS-induced CO-mediated survival mechanism requires functional interactions between the protein kinase B/Akt and extracellular signal-related kinase (ERK)/p38 MAPK signaling pathways activated by TNF-α. In Akt siRNA-transfected CMVEC and in cells with pharmacologically inhibited Akt, Erk1/2, and p38 mitogen-activated protein kinase (MAPK) activities, CORM-A1 was no longer capable of blocking Nox4 activation and apoptosis caused by TNF-α. Overall, Nox4 NADPH oxidase-derived ROS initiate both death and survival pathways in TNF-α-challenged CMVEC. The ROS-dependent cell survival pathway is mediated by an endogenous antioxidant CO, which inhibits Nox4 activation via a mechanism that includes Akt, ERK1/2, and p38 MAPK signaling pathways. The ability of CO to inhibit TNF-α-induced ERK1/2 and p38 MAPK activities in an Akt-dependent manner appears to be the key element in ROS-dependent survival of endothelial cells during TNF-α-mediated brain inflammatory disease. PMID:21123734

Selective phosphodiesterase 5 inhibition does not reduce propofol sedation requirements but affects speed of recovery and plasma cyclic guanosine 3',5'-monophosphate concentrations in healthy volunteers.

PubMed

Engelhardt, Thomas; MacDonald, Jamie; Galley, Helen F; Webster, Nigel R

2005-10-01

Cyclic guanosine 3',5'-monophosphate (cyclic GMP) has been implicated in modulating the effects of anesthesia. We hypothesized that limiting the breakdown of cyclic GMP through selective phosphodiesterase inhibition would influence propofol sedation requirements and plasma cyclic GMP concentrations. Ten volunteers received 100 mg of sildenafil or placebo orally in this placebo-controlled, double-blind, randomized crossover pilot study. Propofol sedation was achieved using a target-controlled infusion system until loss of verbal contact (LVC). Plasma cyclic GMP concentrations were determined at baseline, LVC, and 30 min after LVC. There was no difference in the amount of propofol used, predicted plasma concentration, or duration of sedation in volunteers after sildenafil compared with placebo treatment. Return of spontaneous verbal contact was faster after sildenafil (4 [3-8] min versus 6 [3-5] min, median [range], P = 0.019). Cyclic GMP concentrations were reduced during propofol sedation in the placebo group compared with baseline (P < 0.004). The plasma cyclic GMP concentrations were larger (P = 0.004) at LVC in the sildenafil group compared with placebo. We have shown that selective phosphodiesterase 5 inhibition decreases recovery time from propofol sedation without affecting propofol requirements. The decrease of plasma cyclic GMP concentrations during propofol sedation in the placebo group indicates a potential role of cyclic GMP in propofol anesthesia in humans. Plasma cyclic guanosine 3',5'-monophosphate (cyclic GMP) concentrations are reduced during propofol sedation. Selective phosphodiesterase 5 inhibition, however, does not reduce propofol sedation requirements or plasma cyclic GMP concentrations but affects speed of recovery in healthy volunteers.

Imidazopyridine- and purine-thioacetamide derivatives: potent inhibitors of nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1).

PubMed

Chang, Lei; Lee, Sang-Yong; Leonczak, Piotr; Rozenski, Jef; De Jonghe, Steven; Hanck, Theodor; Müller, Christa E; Herdewijn, Piet

2014-12-11

Nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1) belongs to the family of ecto-nucleotidases, which control extracellular nucleotide, nucleoside, and (di)phosphate levels. To study the (patho)physiological roles of NPP1 potent and selective inhibitors with drug-like properties are required. Therefore, a compound library was screened for NPP1 inhibitors using a colorimetric assay with p-nitrophenyl 5'-thymidine monophosphate (p-Nph-5'-TMP) as an artificial substrate. This led to the discovery of 2-(3H-imidazo[4,5-b]pyridin-2-ylthio)-N-(3,4-dimethoxyphenyl)acetamide (5a) as a hit compound with a Ki value of 217 nM. Subsequent structure-activity relationship studies led to the development of purine and imidazo[4,5-b]pyridine analogues with high inhibitory potency (Ki values of 5.00 nM and 29.6 nM, respectively) when assayed with p-Nph-5'-TMP as a substrate. Surprisingly, the compounds were significantly less potent when tested versus ATP as a substrate, with Ki values in the low micromolar range. A prototypic inhibitor was investigated for its mechanism of inhibition and found to be competitive versus both substrates.

Integrating Health Promotion Into Physical Therapy Practice to Improve Brain Health and Prevent Alzheimer Disease.

PubMed

McGough, Ellen; Kirk-Sanchez, Neva; Liu-Ambrose, Teresa

2017-07-01

Alzheimer disease is the most common cause of dementia, and brain pathology appears years before symptoms are evident. Primary prevention through health promotion can incorporate lifestyle improvement across the lifespan. Risk factor assessment and identifying markers of disease might also trigger preventive measures needed for high-risk individuals and groups. Many potential risk factors are modifiable through exercise, and may be responsive to early intervention strategies to reduce the downward slope toward disability. Through the use of common clinical tests to identify cognitive and noncognitive functional markers of disease, detection and intervention can occur at earlier stages, including preclinical stages of disease. Physical activity and exercise interventions to address modifiable risk factors and impairments can play a pivotal role in the prevention and delay of functional decline, ultimately reducing the incidence of dementia. This article discusses prevention, prediction, plasticity, and participation in the context of preserving brain health and preventing Alzheimer disease and related dementias in aging adults. Rehabilitation professionals have opportunities to slow disease progression through research, practice, and education initiatives. From a clinical perspective, interventions that target brain health through lifestyle changes and exercise interventions show promise for preventing stroke and associated neurovascular diseases in addition to dementia. Physical therapists are well positioned to integrate primary health promotion into practice for the prevention of dementia and other neurological conditions in older adults.

Substrate-specifying determinants of the nucleotide pyrophosphatases/phosphodiesterases NPP1 and NPP2

PubMed Central

2004-01-01

The nucleotide pyrophosphatases/phosphodiesterases NPP1 and NPP2/autotaxin are structurally related eukaryotic ecto-enzymes, but display a very different substrate specificity. NPP1 releases nucleoside 5′-monophosphates from various nucleotides, whereas NPP2 mainly functions as a lysophospholipase D. We have used a domain-swapping approach to map substrate-specifying determinants of NPP1 and NPP2. The catalytic domain of NPP1 fused to the N- and C-terminal domains of NPP2 was hyperactive as a nucleotide phosphodiesterase, but did not show any lysophospholipase D activity. In contrast, chimaeras of the catalytic domain of NPP2 and the N- and/or C-terminal domains of NPP1 were completely inactive. These data indicate that the catalytic domain as well as both extremities of NPP2 contain lysophospholipid-specifying sequences. Within the catalytic domain of NPP1 and NPP2, we have mapped residues close to the catalytic site that determine the activities towards nucleotides and lysophospholipids. We also show that the conserved Gly/Phe-Xaa-Gly-Xaa-Xaa-Gly (G/FXGXXG) motif near the catalytic site is required for metal binding, but is not involved in substrate-specification. Our data suggest that the distinct activities of NPP1 and NPP2 stem from multiple differences throughout the polypeptide chain. PMID:15096095

Insight into the Phosphodiesterase Mechanism from Combined QM/MM Free Energy Simulations

PubMed Central

Wong, Kin-Yiu; Gao, Jiali

2011-01-01

Summary Molecular dynamics simulations employing a combined quantum mechanical and molecular mechanical potential have been carried out to elucidate the reaction mechanism of the hydrolysis of a cyclic nucleotide cAMP substrate by phosphodiesterase 4B (PDE4B). PDE4B is a member of the PDE superfamily of enzymes that play crucial roles in cellular signal transduction. We have determined a two-dimensional potential of mean force for the coupled phosphoryl bond cleavage and proton transfer through a general acid catalysis mechanism in PDE4B. The results indicate that the ring-opening process takes place through an SN2 reaction mechanism, followed by a proton transfer to stabilize the leaving group. The computed free energy of activation for the PDE4B-catalyzed cAMP hydrolysis is about 13 kcal/mol and an overall reaction free energy is about −17 kcal/mol, both in accord with experimental results. In comparison with the uncatalyzed reaction in water, the enzyme PDE4B provides a strong stabilization of the transition state, lowering the free energy barrier by 14 kcal/mol. We found that the proton transfer from the general acid residue His234 to the O3' oxyanion of the ribosyl leaving group lags behind the nucleophilic attack, resulting in a shallow minimum on the free energy surface. A key contributing factor to transition state stabilization is the elongation of the distance between the divalent metal ions Zn2+ and Mg2+ in the active site as the reaction proceeds from the Michaelis complex to the transition state. PMID:21595828

Distribution of ELOVL4 in the Developing and Adult Mouse Brain

PubMed Central

Sherry, David M.; Hopiavuori, Blake R.; Stiles, Megan A.; Rahman, Negar S.; Ozan, Kathryn G.; Deak, Ferenc; Agbaga, Martin-Paul; Anderson, Robert E.

2017-01-01

ELOngation of Very Long chain fatty acids (ELOVL)-4 is essential for the synthesis of very long chain-fatty acids (fatty acids with chain lengths ≥ 28 carbons). The functions of ELOVL4 and its very long-chain fatty acid products are poorly understood at present. However, mutations in ELOVL4 cause neurodevelopmental or neurodegenerative diseases that vary according to the mutation and inheritance pattern. Heterozygous inheritance of different ELOVL4 mutations causes Stargardt-like Macular Dystrophy or Spinocerebellar Ataxia type 34. Homozygous inheritance of ELOVL4 mutations causes more severe disease characterized by seizures, intellectual disability, ichthyosis, and premature death. To better understand ELOVL4 and very long chain fatty acid function in the brain, we examined ELOVL4 expression in the mouse brain between embryonic day 18 and postnatal day 60 by immunolabeling using ELOVL4 and other marker antibodies. ELOVL4 was widely expressed in a region- and cell type-specific manner, and was restricted to cell bodies, consistent with its known localization to endoplasmic reticulum. ELOVL4 labeling was most prominent in gray matter, although labeling also was present in some cells located in white matter. ELOVL4 was widely expressed in the developing brain by embryonic day 18 and was especially pronounced in regions underlying the lateral ventricles and other neurogenic regions. The basal ganglia in particular showed intense ELOVL4 labeling at this stage. In the postnatal brain, cerebral cortex, hippocampus, cerebellum, thalamus, hypothalamus, midbrain, pons, and medulla all showed prominent ELOVL4 labeling, although ELOVL4 distribution was not uniform across all cells or subnuclei within these regions. In contrast, the basal ganglia showed little ELOVL4 labeling in the postnatal brain. Double labeling studies showed that ELOVL4 was primarily expressed by neurons, although presumptive oligodendrocytes located in white matter tracts also showed labeling. Little

ErbB4 in Laminated Brain Structures: A Neurodevelopmental Approach to Schizophrenia

PubMed Central

Perez-Garcia, Carlos G.

2015-01-01

The susceptibility genes for schizophrenia Neuregulin-1 (NRG1) and ErbB4 have critical functions during brain development and in the adult. Alterations in the ErbB4 signaling pathway cause a variety of neurodevelopmental defects including deficiencies in neuronal migration, synaptic plasticity, and myelination. I have used the ErbB4-/- HER4heart KO mice to study the neurodevelopmental insults associated to deficiencies in the NRG1-ErbB4 signaling pathway and their potential implication with brain disorders such as schizophrenia, a chronic psychiatric disease affecting 1% of the population worldwide. ErbB4 deletion results in an array of neurodevelopmental deficits that are consistent with a schizophrenic model. First, similar defects appear in multiple brain structures, from the cortex to the cerebellum. Second, these defects affect multiple aspects of brain development, from deficits in neuronal migration to impairments in excitatory/inhibitory systems, including reductions in brain volume, cortical and cerebellar heterotopias, alterations in number and distribution of specific subpopulations of interneurons, deficiencies in the astrocytic and oligodendrocytic lineages, and additional insults in major brain structures. This suggests that alterations in specific neurodevelopmental genes that play similar functions in multiple neuroanatomical structures might account for some of the symptomatology observed in schizophrenic patients, such as defects in cognition. ErbB4 mutation uncovers flaws in brain development that are compatible with a neurodevelopmental model of schizophrenia, and it establishes a comprehensive model to study the basis of the disorder before symptoms are detected in the adult. PMID:26733804

Effect of the phosphodiesterase 4 inhibitor roflumilast on glucose metabolism in patients with treatment-naive, newly diagnosed type 2 diabetes mellitus.

PubMed

Wouters, E F M; Bredenbröker, D; Teichmann, P; Brose, M; Rabe, K F; Fabbri, L M; Göke, B

2012-09-01

The phosphodiesterase 4 inhibitor roflumilast is a first-in-class antiinflammatory treatment for severe chronic obstructive pulmonary disease (COPD) associated with chronic bronchitis and a history of frequent exacerbations. In previous clinical studies, a transient and reversible weight decrease was reported with roflumilast, suggesting the systemic actions of this drug may impact metabolism. Our objective was to investigate the effects of roflumilast on glucose homeostasis and body weight. We conducted a 12-wk, randomized, double-blind, placebo-controlled multicenter study with outpatients. Patients (n = 205) with newly diagnosed type 2 diabetes mellitus (DM2) but without COPD were included in the study. Roflumilast 500 μg or placebo was administered once daily. We evaluated mean change in blood glycated hemoglobin levels. We also evaluated mean change from baseline in the postmeal area under the curve (AUC) for a range of metabolic parameters. Roflumilast was associated with a significantly greater reduction in glycated hemoglobin levels than placebo (least square mean = -0.45%; P < 0.0001) in patients with DM2. In the roflumilast group, postmeal AUC decreased significantly from baseline to last visit for free fatty acids, glycerol, glucose, and glucagon, whereas they slightly increased for C-peptide and insulin. In contrast to roflumilast, the glucagon AUC increased with placebo, and the insulin AUC decreased. Between-treatment analysis revealed statistically significant differences in favor of roflumilast for glucose (P = 0.0082), glycerol (P = 0.0104), and C-peptide levels (P = 0.0033). Patients in both treatment groups lost weight, although the between-treatment difference of the changes from baseline to last visit [-0.7 (0.4) kg] was not statistically significant (P = 0.0584). Roflumilast lowered glucose levels in patients with newly diagnosed DM2 without COPD, suggesting positive effects on glucose homoeostasis.

Brain responses in 4-month-old infants are already language specific.

PubMed

Friederici, Angela D; Friedrich, Manuela; Christophe, Anne

2007-07-17

Language is the most important faculty that distinguishes humans from other animals. Infants learn their native language fast and effortlessly during the first years of life, as a function of the linguistic input in their environment. Behavioral studies reported the discrimination of melodic contours [1] and stress patterns [2, 3] in 1-4-month-olds. Behavioral [4, 5] and brain measures [6-8] have shown language-independent discrimination of phonetic contrasts at that age. Language-specific discrimination, however, has been reported for phonetic contrasts only for 6-12-month-olds [9-12]. Here we demonstrate language-specific discrimination of stress patterns in 4-month-old German and French infants by using electrophysiological brain measures. We compare the processing of disyllabic words differing in their rhythmic structure, mimicking German words being stressed on the first syllable, e.g., pápa/daddy[13], and French ones being stressed on the second syllable, e.g., papá/daddy. Event-related brain potentials reveal that experience with German and French differentially affects the brain responses of 4-month-old infants, with each language group displaying a processing advantage for the rhythmic structure typical in its native language. These data indicate language-specific neural representations of word forms in the infant brain as early as 4 months of age.

Brain GLP-1/IGF-1 Signaling and Autophagy Mediate Exendin-4 Protection Against Apoptosis in Type 2 Diabetic Rats.

PubMed

Candeias, Emanuel; Sebastião, Inês; Cardoso, Susana; Carvalho, Cristina; Santos, Maria Sancha; Oliveira, Catarina Resende; Moreira, Paula I; Duarte, Ana I

2018-05-01

Type 2 diabetes (T2D) is a modern socioeconomic burden, mostly due to its long-term complications affecting nearly all tissues. One of them is the brain, whose dysfunctional intracellular quality control mechanisms (namely autophagy) may upregulate apoptosis, leading to cognitive dysfunction and Alzheimer disease (AD). Since impaired brain insulin signaling may constitute the crosslink between T2D and AD, its restoration may be potentially therapeutic herein. Accordingly, the insulinotropic anti-T2D drugs from glucagon-like peptide-1 (GLP-1) mimetics, namely, exendin-4 (Ex-4), could be a promising therapy. In line with this, we hypothesized that peripherally administered Ex-4 rescues brain intracellular signaling pathways, promoting autophagy and ultimately protecting against chronic T2D-induced apoptosis. Thus, we aimed to explore the effects of chronic, continuous, subcutaneous (s.c.) exposure to Ex-4 in brain cortical GLP-1/insulin/insulin-like growth factor-1 (IGF-1) signaling, and in autophagic and cell death mechanisms in middle-aged (8 months old), male T2D Goto-Kakizaki (GK) rats. We used brain cortical homogenates obtained from middle-aged (8 months old) male Wistar (control) and T2D GK rats. Ex-4 was continuously administered for 28 days, via s.c. implanted micro-osmotic pumps (5 μg/kg/day; infusion rate 2.5 μL/h). Peripheral characterization of the animal models was given by the standard biochemical analyses of blood or plasma, the intraperitoneal glucose tolerance test, and the heart rate. GLP-1, insulin, and IGF-1, their downstream signaling and autophagic markers were evaluated by specific ELISA kits and Western blotting. Caspase-like activities and other apoptotic markers were given by colorimetric methods and Western blotting. Chronic Ex-4 treatment attenuated peripheral features of T2D in GK rats, including hyperglycemia and insulin resistance. Furthermore, s.c. Ex-4 enhanced their brain cortical GLP-1 and IGF-1 levels, and subsequent

Lack of death receptor 4 (DR4) expression through gene promoter methylation in gastric carcinoma.

PubMed

Lee, Kyung Hwa; Lim, Sang Woo; Kim, Ho Gun; Kim, Dong Yi; Ryu, Seong Yeob; Joo, Jae Kyun; Kim, Jung Chul; Lee, Jae Hyuk

2009-07-01

To determine the underlying mechanism for the differential expression, the extent of promoter methylation in tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-related genes acting downstream of TRAIL was examined in early and advanced gastric carcinomas. The extent of promoter methylation in the DR4, DR5, DcR1, DcR2, and CASP8 genes was quantified using bisulfite modification and methylation-specific polymerase chain reaction. The promoters for DcR1, DcR2, and CASP8 were largely unmethylated in early gastric carcinoma, advanced gastric carcinoma, and controls, with no significant difference among them. Protein levels of DR4, DcR1, and DcR2 as revealed by immunohistochemistry correlated with the extent of the respective promoter methylation (P < 0.05 in all cases). Hypomethylation, rather than hypermethylation, of the DR4 promoter was noted in invasive gastric malignancies, with statistical significance (P = 0.003). The promoter methylation status of TRAIL receptors in gastric carcinoma may have clinical implications for improving therapeutic strategies in patients with gastric carcinoma.

Salvage whole brain radiotherapy or stereotactic radiosurgery after initial stereotactic radiosurgery for 1-4 brain metastases.

PubMed

Liu, Yufei; Alexander, Brian M; Chen, Yu-Hui; Horvath, Margaret C; Aizer, Ayal A; Claus, Elizabeth B; Dunn, Ian F; Golby, Alexandra J; Johnson, Mark D; Friesen, Scott; Mannarino, Edward G; Wagar, Matthew; Hacker, Fred L; Arvold, Nils D

2015-09-01

Patients with limited brain metastases are often candidates for stereotactic radiosurgery (SRS) or whole brain radiotherapy (WBRT). Among patients who receive SRS, the likelihood and timing of salvage WBRT or SRS remains unclear. We examined rates of salvage WBRT or SRS among 180 patients with 1-4 newly diagnosed brain metastases who received index SRS from 2008-2013. Competing risks multivariable analysis was used to examine factors associated with time to WBRT. Patients had non-small cell lung (53 %), melanoma (23 %), breast (10 %), renal (6 %), or other (8 %) cancers. Median age was 62 years. Patients received index SRS to 1 (60 %), 2 (21 %), 3 (13 %), or 4 (7 %) brain metastases. Median survival after SRS was 9.7 months (range, 0.3-67.6 months). No further brain-directed radiotherapy was delivered after index SRS in 55 % of patients. Twenty-seven percent of patients ever received salvage WBRT, and 30 % ever received salvage SRS; 12 % of patients received both salvage WBRT and salvage SRS. Median time to salvage WBRT or salvage SRS were 5.6 and 6.1 months, respectively. Age ≤60 years (adjusted hazard ratio [AHR] = 2.80; 95 % CI 1.05-7.51; P = 0.04) and controlled/absent extracranial disease (AHR = 6.76; 95 % CI 1.60-28.7; P = 0.01) were associated with shorter time to salvage WBRT. Isolated brain progression caused death in only 11 % of decedents. In summary, most patients with 1-4 brain metastases receiving SRS never require salvage WBRT or SRS, and the remainder do not require salvage treatment for a median of 6 months.

3,4-Methylenedioxymethamphetamine (MDMA), but not morphine, alters APP processing in the rat brain.

PubMed

Kálmán, János; Bjelik, Annamária; Hugyecz, Marietta; Tímár, Júlia; Gyarmati, Zsuzsanna; Zana, Marianna; Fürst, Zsuzsanna; Janka, Zoltán; Rakonczay, Zoltán; Horváth, Zoltán; Pákáski, Magdolna

2007-04-01

The abuse of drugs such as opioids and 3,4-methylenedioxymethamphetamine (MDMA or 'ecstasy') can have detrimental effects on the cognitive functions, but the exact molecular mechanism whereby these drugs promote neurodegeneration remains to be elucidated. The major purpose of the present pilot study was to determine whether the chronic in-vivo administration of morphine (10 mg/kg) or MDMA (1 mg/kg) to rats can alter the expression and processing of amyloid precursor protein (APP), the central molecule in the proposed pathomechanism of Alzheimer's disease. MDMA treatment significantly decreased the production of APP in the cytosolic fraction of the brain cortex. A concomitant 25% increase was found both in the beta-secretase (BACE) and APP mRNA levels (108%). In contrast, in the applied single dosage chronic morphine treatment did not influence either the APP and BACE protein levels or the APP mRNA production. These results indicate that the chronic use of 'ecstasy', but not morphine, may be harmful via a novel mode of action, i.e. by altering the APP expression and processing in the brain.

Lipolytic effect of a polyphenolic citrus dry extract of red orange, grapefruit, orange (SINETROL) in human body fat adipocytes. Mechanism of action by inhibition of cAMP-phosphodiesterase (PDE).

PubMed

Dallas, Constantin; Gerbi, Alain; Tenca, Guillaume; Juchaux, Franck; Bernard, François-Xavier

2008-10-01

The present study investigated the lipolytic (break of fat stored) effect of a citrus-based polyphenolic dietary supplement (SINETROL) at human adipocytes (ex vivo), body fat (clinical) and biochemical levels (inhibition of phosphodiesterase). Free fatty acids (FFA) release was used as indicator of human adipocyte lipolysis and SINETROL activity has been compared with known lipolytic products (isoproterenol, theopylline and caffeine). SINETROL stimulated significantly the lipolytic activity in a range of 6 fold greater than the control. Moreover, SINETROL has 2.1 greater activity than guarana 12% caffeine while its content in caffeine is 3 times lower. Clinically, two groups of 10 volunteers with BMI relevant of overweight were compared during 4 and 12 weeks with 1.4 g/day SINETROL and placebo supplementation. In the SINETROL Group the body fat (%) decreased with a significant difference of 5.53% and 15.6% after 4 and 12 weeks, respectively, while the body weight (kg) decreased with a significant difference of 2.2 and 5.2 kg after 4 and 12 weeks, respectively. These observed effects are linked to SINETROL polyphenolic composition and its resulting synergistic activity. SINETROL is a potent inhibitor of cAMP-phosphodiesterase (PDE) (97%) compared to other purified compounds (cyanidin-3 glycoside, narangin, caffeine). These results suggest that SINETROL has a strong lipolytic effect mediated by cAMP-PDE inhibition. SINETROL may serve to prevent obesity by decreasing BMI.

The EAL-domain protein FcsR regulates flagella, chemotaxis and type III secretion system in Pseudomonas aeruginosa by a phosphodiesterase independent mechanism.

PubMed

Rossello, Jessica; Lima, Analía; Gil, Magdalena; Rodríguez Duarte, Jorge; Correa, Agustín; Carvalho, Paulo C; Kierbel, Arlinet; Durán, Rosario

2017-08-31

The second messenger c-di-GMP regulates the switch between motile and sessile bacterial lifestyles. A general feature of c-di-GMP metabolism is the presence of a surprisingly large number of genes coding for diguanylate cyclases and phosphodiesterases, the enzymes responsible for its synthesis and degradation respectively. However, the physiological relevance of this apparent redundancy is not clear, emphasizing the need for investigating the functions of each of these enzymes. Here we focused on the phosphodiesterase PA2133 from Pseudomonas aeruginosa, an important opportunistic pathogen. We phenotypically characterized P. aeruginosa strain K overexpressing PA2133 or its inactive mutant. We showed that biofilm formation and motility are severely impaired by overexpression of PA2133. Our quantitative proteomic approach applied to the membrane and exoprotein fractions revealed that proteins involved in three processes were mostly affected: flagellar motility, type III secretion system and chemotaxis. While inhibition of biofilm formation can be ascribed to the phosphodiesterase activity of PA2133, down-regulation of flagellar, chemotaxis, and type III secretion system proteins is independent of this enzymatic activity. Based on these unexpected effects of PA2133, we propose to rename this gene product FcsR, for Flagellar, chemotaxis and type III secretion system Regulator.

Microplate-based method to screen inhibitors of isozymes of cyclic nucleotide phosphodiesterase fused to SUMO.

PubMed

Chen, Chunyan; Liu, Miaomiao; Wu, Jing; Yang, Xiaolan; Hu, Xiaolei; Pu, Jun; Long, Gaobo; Xie, Yanling; Jiang, Hairong; Yuan, Yonghua; Liao, Fei

2014-12-01

The feasibility for microplate-based screening of inhibitors of isozymes of cyclic nucleotide phosphodiesterase (PDE) was tested via the coupled action of a phosphatase on adenosine-5'-monophosphate and an improved malachite green assay of phosphate. Human full-length PDE4B2 and truncated mutant (152-528aa) were expressed in Escherichia coli via fusion to SUMO, which after purification through Ni-NTA column exhibited specific activities >0.017 U mg(-1). In the presence of proteins <30 mg L(-1), absorbance for 10 µΜ phosphate was measurable; a PDE isozyme of specific activity over 0.008 U mg(-1) after reaction for 20 min thus suited for microplate-based screening of inhibitors. By using Biotek ELX 800 microplate reader, affinities of two forms of PEDE4B2 for cAMP, rolipram and papaverine varied over three magnitudes and were consistent with those by routine assay, respectively. Hence, the proposed method was promising for high-throughput-screening of inhibitors of phosphate-releasing enzymes bearing specific activities over 0.008 U mg(-1).

Targeting New Pharmacological Approaches for Alzheimer's Disease: Potential for Statins and Phosphodiesterase Inhibitors.

PubMed

Sallustio, Fabrizio; Studer, Valeria

2016-01-01

Alzheimer's disease (AD) is the most common cause of dementia among the elderly. It is pathologically characterized by diffused extracellular deposits, senile plaques, and intracellular neurofibrillary tangles in the brain, responsible for neuronal dysfunction and cell death. Memory, language and other cognitive functions can be affected to a limited extent in the initial stage called mild cognitive impairment (MCI) or in a more severe and daily life interfering manner in the later stage called dementia. Currently no effective disease-modifying treatment exists for the majority of neurodegenerative diseases. Failure of therapy aimed at affecting beta amyloid pathology has led research to investigate alternative approaches. Recent findings address statins and phosphodiesterase (PDE) inhibitors as compounds able to affect different mechanisms underlying AD. Statins could exert several effects based on their lipid-lowering and cerebral blood flow increasing abilities but also pleiotropic/antinflammatory and neuroprotective properties have been claimed. PDEs act as regulators of intracellular signaling cascades through the control of two second messengers, cyclic adenosine monophosphate and cyclic guanosine monophosphate. PDE inhibitors effects in animal models of AD have been promising and their proven safety in clinical use create high expectations for the treatment of AD. In this review, we will report main data and evidence on: 1. Current pathophysiological theories of AD in order to better understand which mechanisms lead to pathological changes and can be affected by therapies; 2. The use of statins and PDE inhibitors in animal models of AD and in humans, analyzing their mechanisms of action.

Consumption of tyrosine in royal jelly increases brain levels of dopamine and tyramine and promotes transition from normal to reproductive workers in queenless honey bee colonies.

PubMed

Matsuyama, Syuhei; Nagao, Takashi; Sasaki, Ken

2015-01-15

Dopamine (DA) and tyramine (TA) have neurohormonal roles in the production of reproductive workers in queenless colonies of honey bees, but the regulation of these biogenic amines in the brain are still largely unclear. Nutrition is an important factor in promoting reproduction and might be involved in the regulation of these biogenic amines in the brain. To test this hypothesis, we examined the effect of oral treatments of tyrosine (Tyr; a common precursor of DA, TA and octopamine, and a component of royal jelly) in queenless workers and quantified the resulting production of biogenic amines. Tyrosine treatments enhanced the levels of DA, TA and their metabolites in the brain. Workers fed royal jelly had significantly larger brain levels of Tyr, DA, TA and the metabolites in the brains compared with those bees fed honey or sucrose (control). Treatment with Tyr also inhibited the behavior of workers outside of the hive and promoted ovarian development. These results suggest that there is a link between nutrition and the regulation of DA and TA in the brain to promote the production of reproductive workers in queenless honey bee colonies. Copyright © 2014 Elsevier Inc. All rights reserved.

Endocannabinoids as a Target for the Treatment of Traumatic Brain Injury

DTIC Science & Technology

2013-11-01

COVERED 4 October 201 - 3 October 201 4. TITLE AND SUBTITLE Endocannabinoids as a Target for the Treatment of Traumatic Brain Injury 5a. CONTRACT...injury, blood brain barrier, neuroinflammation, neurological dysfunction, endocannabinoids Table of Contents Introduction...promote neuroinflammation and potentially lead to neurodegeneration. We have previously demonstrated that treatments to the endocannabinoid system 2

Exercise promotes the expression of brain derived neurotrophic factor (BDNF) through the action of the ketone body β-hydroxybutyrate.

PubMed

Sleiman, Sama F; Henry, Jeffrey; Al-Haddad, Rami; El Hayek, Lauretta; Abou Haidar, Edwina; Stringer, Thomas; Ulja, Devyani; Karuppagounder, Saravanan S; Holson, Edward B; Ratan, Rajiv R; Ninan, Ipe; Chao, Moses V

2016-06-02

Exercise induces beneficial responses in the brain, which is accompanied by an increase in BDNF, a trophic factor associated with cognitive improvement and the alleviation of depression and anxiety. However, the exact mechanisms whereby physical exercise produces an induction in brain Bdnf gene expression are not well understood. While pharmacological doses of HDAC inhibitors exert positive effects on Bdnf gene transcription, the inhibitors represent small molecules that do not occur in vivo. Here, we report that an endogenous molecule released after exercise is capable of inducing key promoters of the Mus musculus Bdnf gene. The metabolite β-hydroxybutyrate, which increases after prolonged exercise, induces the activities of Bdnf promoters, particularly promoter I, which is activity-dependent. We have discovered that the action of β-hydroxybutyrate is specifically upon HDAC2 and HDAC3, which act upon selective Bdnf promoters. Moreover, the effects upon hippocampal Bdnf expression were observed after direct ventricular application of β-hydroxybutyrate. Electrophysiological measurements indicate that β-hydroxybutyrate causes an increase in neurotransmitter release, which is dependent upon the TrkB receptor. These results reveal an endogenous mechanism to explain how physical exercise leads to the induction of BDNF.

Partial reconstitution of photoreceptor cGMP phosphodiesterase characteristics in cGMP phosphodiesterase-5.

PubMed

Granovsky, A E; Artemyev, N O

2001-06-15

Photoreceptor cGMP phosphodiesterases (PDE6) are uniquely qualified to serve as effector enzymes in the vertebrate visual transduction cascade. In the dark-adapted photoreceptors, the activity of PDE6 is blocked via tight association with the inhibitory gamma-subunits (Pgamma). The Pgamma block is removed in the light-activated PDE6 by the visual G protein, transducin. Transducin-activated PDE6 exhibits an exceptionally high catalytic rate of cGMP hydrolysis ensuring high signal amplification. To identify the structural determinants for the inhibitory interaction with Pgamma and the remarkable cGMP hydrolytic ability, we sought to reproduce the PDE6 characteristics by mutagenesis of PDE5, a related cyclic GMP-specific, cGMP-binding PDE. PDE5 is insensitive to Pgamma and has a more than 100-fold lower k(cat) for cGMP hydrolysis. Our mutational analysis of chimeric PDE5/PDE6alpha' enzymes revealed that the inhibitory interaction of cone PDE6 catalytic subunits (PDE6alpha') with Pgamma is mediated primarily by three hydrophobic residues at the entry to the catalytic pocket, Met(758), Phe(777), and Phe(781). The maximal catalytic rate of PDE5 was enhanced by at least 10-fold with substitutions of PDE6alpha'-specific glycine residues for the corresponding PDE5 alanine residues, Ala(608) and Ala(612). The Gly residues are adjacent to the highly conserved metal binding motif His-Asn-X-X-His, which is essential for cGMP hydrolysis. Our results suggest that the unique Gly residues allow the PDE6 metal binding site to adopt a more favorable conformation for cGMP hydrolysis.

Differential metabolism of 4-hydroxynonenal in liver, lung and brain of mice and rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Ruijin; Dragomir, Ana-Cristina; Mishin, Vladimir

2014-08-15

The lipid peroxidation end-product 4-hydroxynonenal (4-HNE) is generated in tissues during oxidative stress. As a reactive aldehyde, it forms Michael adducts with nucleophiles, a process that disrupts cellular functioning. Liver, lung and brain are highly sensitive to xenobiotic-induced oxidative stress and readily generate 4-HNE. In the present studies, we compared 4-HNE metabolism in these tissues, a process that protects against tissue injury. 4-HNE was degraded slowly in total homogenates and S9 fractions of mouse liver, lung and brain. In liver, but not lung or brain, NAD(P)+ and NAD(P)H markedly stimulated 4-HNE metabolism. Similar results were observed in rat S9 fractionsmore » from these tissues. In liver, lung and brain S9 fractions, 4-HNE formed protein adducts. When NADH was used to stimulate 4-HNE metabolism, the formation of protein adducts was suppressed in liver, but not lung or brain. In both mouse and rat tissues, 4-HNE was also metabolized by glutathione S-transferases. The greatest activity was noted in livers of mice and in lungs of rats; relatively low glutathione S-transferase activity was detected in brain. In mouse hepatocytes, 4-HNE was rapidly taken up and metabolized. Simultaneously, 4-HNE-protein adducts were formed, suggesting that 4-HNE metabolism in intact cells does not prevent protein modifications. These data demonstrate that, in contrast to liver, lung and brain have a limited capacity to metabolize 4-HNE. The persistence of 4-HNE in these tissues may increase the likelihood of tissue injury during oxidative stress. - Highlights: • Lipid peroxidation generates 4-hydroxynonenal, a highly reactive aldehyde. • Rodent liver, but not lung or brain, is efficient in degrading 4-hydroxynonenal. • 4-hydroxynonenal persists in tissues with low metabolism, causing tissue damage.« less

Insight into the phosphodiesterase mechanism from combined QM/MM free energy simulations.

PubMed

Wong, Kin-Yiu; Gao, Jiali

2011-07-01

Molecular dynamics simulations employing a combined quantum mechanical and molecular mechanical potential have been carried out to elucidate the reaction mechanism of the hydrolysis of a cyclic nucleotide cAMP substrate by phosphodiesterase 4B (PDE4B). PDE4B is a member of the PDE superfamily of enzymes that play crucial roles in cellular signal transduction. We have determined a two-dimensional potential of mean force (PMF) for the coupled phosphoryl bond cleavage and proton transfer through a general acid catalysis mechanism in PDE4B. The results indicate that the ring-opening process takes place through an S(N)2 reaction mechanism, followed by a proton transfer to stabilize the leaving group. The computed free energy of activation for the PDE4B-catalyzed cAMP hydrolysis is about 13 kcal·mol(-1) and an overall reaction free energy is about -17 kcal·mol(-1), both in accord with experimental results. In comparison with the uncatalyzed reaction in water, the enzyme PDE4B provides a strong stabilization of the transition state, lowering the free energy barrier by 14 kcal·mol(-1). We found that the proton transfer from the general acid residue His234 to the O3' oxyanion of the ribosyl leaving group lags behind the nucleophilic attack, resulting in a shallow minimum on the free energy surface. A key contributing factor to transition state stabilization is the elongation of the distance between the divalent metal ions Zn(2+) and Mg(2+) in the active site as the reaction proceeds from the Michaelis complex to the transition state. © 2011 The Authors Journal compilation © 2011 FEBS.

n-3 Polyunsaturated Fatty Acids Reduce Neonatal Hypoxic/Ischemic Brain Injury by Promoting Phosphatidylserine Formation and Akt Signaling.

PubMed

Zhang, Wenting; Liu, Jia; Hu, Xiaoming; Li, Peiying; Leak, Rehana K; Gao, Yanqin; Chen, Jun

2015-10-01

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) attenuate neonatal hypoxic/ischemic (H/I) brain damage, but the underlying mechanisms are not fully understood. This study tested the hypothesis that n-3 PUFAs enhance Akt-dependent prosurvival signaling by promoting the biosynthesis of phosphatidylserine in neuronal cell membranes. Dietary n-3 PUFA supplementation was initiated on the second day of pregnancy in dams. H/I was induced in 7-day-old rat pups by ipsilateral common carotid artery occlusion followed by hypoxia (8% oxygen for 2.5 hours). Neurological outcomes, brain tissue loss, cell death, and the activation of signaling events were assessed after H/I. The effects of n-3 PUFAs (docosahexaenoic acid and eicosapentaenoic acid) on oxygen-glucose deprivation-induced cell death and the underlying mechanism of protection were also examined in primary cortical neuron cultures. n-3 PUFAs reduced brain tissue loss at 7 days after H/I and improved neurological outcomes, whereas inhibition of PI3K/Akt signaling by LY294002 partially abrogated this neuroprotective effect. Docosahexaenoic acid/eicosapentaenoic acid also prevented ischemic neuronal death through the Akt prosurvival pathway in vitro. Furthermore, docosahexaenoic acid/eicosapentaenoic acid increased the production of phosphatidylserine, the major membrane-bound phospholipids, after ischemia both in vitro and in vivo. A reduction in membrane phosphatidylserine by shRNA-mediated knockdown of phosphatidylserine synthetase-1 attenuated Akt activation and neuronal survival after docosahexaenoic acid/eicosapentaenoic acid treatment in the oxygen-glucose deprivation model. n-3 PUFAs robustly protect against H/I-induced brain damage in neonates by activating Akt prosurvival pathway in compromised neurons. In addition, n-3 PUFAs promote the formation of membrane phosphatidylserine, thereby promoting Akt activity and improving cellular survival. © 2015 American Heart Association, Inc.

Brain-derived neurotrophic factor promoter methylation and cortical thickness in recurrent major depressive disorder.

PubMed

Na, Kyoung-Sae; Won, Eunsoo; Kang, June; Chang, Hun Soo; Yoon, Ho-Kyoung; Tae, Woo Suk; Kim, Yong-Ku; Lee, Min-Soo; Joe, Sook-Haeng; Kim, Hyun; Ham, Byung-Joo

2016-02-15

Recent studies have reported that methylation of the brain-derived neurotrophic factor (BDNF) gene promoter is associated with major depressive disorder (MDD). This study aimed to investigate the association between cortical thickness and methylation of BDNF promoters as well as serum BDNF levels in MDD. The participants consisted of 65 patients with recurrent MDD and 65 age- and gender-matched healthy controls. Methylation of BDNF promoters and cortical thickness were compared between the groups. The right medial orbitofrontal, right lingual, right lateral occipital, left lateral orbitofrontal, left pars triangularis, and left lingual cortices were thinner in patients with MDD than in healthy controls. Among the MDD group, right pericalcarine, right medical orbitofrontal, right rostral middle frontal, right postcentral, right inferior temporal, right cuneus, right precuneus, left frontal pole, left superior frontal, left superior temporal, left rostral middle frontal and left lingual cortices had inverse correlations with methylation of BDNF promoters. Higher levels of BDNF promoter methylation may be closely associated with the reduced cortical thickness among patients with MDD. Serum BDNF levels were significantly lower in MDD, and showed an inverse relationship with BDNF methylation only in healthy controls. Particularly the prefrontal and occipital cortices seem to indicate key regions in which BDNF methylation has a significant effect on structure.

Cancer-associated fibroblast promote transmigration through endothelial brain cells in three-dimensional in vitro models.

PubMed

Choi, Yoon Pyo; Lee, Joo Hyun; Gao, Ming-Qing; Kim, Baek Gil; Kang, Suki; Kim, Se Hoon; Cho, Nam Hoon

2014-11-01

Brain metastases are associated with high morbidity as well as with poor prognosis and survival in breast cancer patients. Despite its clinical importance, metastasis of breast cancer cells through the blood-brain barrier (BBB) is poorly understood. The objective of our study was to investigate whether cancer-associated fibroblasts (CAFs) play crucial roles in breast cancer brain metastasis. Using a cell adhesion assays, in vitro BBB permeability and transmigration assays and soft agar colony formation assays, we investigated the physical roles of CAFs in breast cancer brain metastasis. We also performed immunofluorescence, flow cytometric analysis, Droplet Digital PCR and Simon™ Simple Western System to confirm changes in expression levels. We established two novel three-dimensional (3D) culture systems using a perpendicular slide chamber and applying 3D embedded culture method to reflect brain metastasis conditions. With a newly developed device, CAFs was proven to promote cell adhesion to human brain microvascular endothelial cells, in vitro BBB permeability and transmigration and colony formation of breast cancer cells. Furthermore, CAFs enhanced the invasive migration of breast cancer cells in two kinds of 3D cultures. These 3D models also reliably recapitulate the initial steps of BBB transmigration, micro-metastasis and colonization. Expression of integrin α5β1 and αvβ3, c-MET and α2,6-siayltransferase was increased in breast cancer cells that migrated through the BBB. In conclusion, based on our in vitro BBB and co-culture models, our data suggest that CAFs may play a role in breast cancer brain metastasis. © 2014 UICC.

4Bs or Not 4Bs: Bricks, Bytes, Brains, and Bandwidth

ERIC Educational Resources Information Center

Treat, Tod

2011-01-01

The effective integration of planning to include bricks, bytes, brains, and bandwidth (the 4Bs) represents an opportunity for community colleges to extend their capacity as knowledge-intensive organizations, coupling knowledge, technology, and learning. Integration is important to ensure that the interplay among organizations, agents within them,…

[Mechanism for synergistic effect of IRF4 and MITF on tyrosinase promoter].

PubMed

Song, Jian; Liu, Xueming; Li, Jiada; Liu, Huadie; Peng, Zhen; Chen, Hongsheng; Mei, Lingyun; He, Chufeng; Feng, Yong

2018-05-28

To investigate the mechanism for the synergistic effect of interferon regulatory factor 4 (IRF4) and microphthalmia-associated transcription factor (MITF) on tyrosinase (TYR) promoter.
 Methods: The synergistic transcriptional effect, subcellular localization, and protein-protein interaction for IRF4 and MITF were observed by luciferase assay, immunofluorescence, GST-pull down, and co-immunoprecipitation, respectively.
 Results: IRF4 and MITF proteins were co-expressed in the cell nucleus. IRF4 augmented the transcriptional function of MITF (but not the mutant MITF) to activate the expression of the TYR promoter, but with no effect on other MITF-specific target promoters. IRF4 alone did not affect TYR promoter significantly. No direct interaction between the two proteins was noted.
 Conclusion: IRF4 and MITF exert a specifically synergistic effect on activation of TYR promoter through IRF4-mediated upregulation of transcriptional function of MITF. This synergistic effect is mainly regulated by MITF; DNA might be involved in the interaction between the two proteins.

Up-regulation of Vps4A promotes neuronal apoptosis after intracerebral hemorrhage in adult rats.

PubMed

Ren, Jianbing; Yuan, Debin; Xie, Lili; Tao, Xuelei; Duan, Chenwei; Bao, Yifeng; He, Yunfeng; Ge, Jianbin; Lu, Hongjian

2017-04-01

Vps4, vacuolar protein sorting 4, belongs to ATPases Associated with diverse cellular Activities (AAA) protein family which is made up of Vps4A and Vps4B. Previous studies demonstrated that Vps4A plays vital roles in diverse aspects such as virus budding, the efficient transport of H-Ras to the PM (plasma membrane) and the involvement in the MVB (multivesiculate bodies) pathway. Interestingly, Vps4A is also expressed in the brain. However, the distribution and function of Vps4A in ICH diseases remain unclear. In this study, we show that Vps4A may be involved in neuronal apoptosis during pathophysiological processes of intracerebral hemorrhage (ICH). Based on the results of Western blot and immunohistochemistry, we found a remarkable up-regulation of Vps4A expression surrounding the hematoma after ICH. Double labeled immunofluorescence showed that Vps4A was co-expressed with NeuN but rarely with astrocytes and microglia. Morever, we detected that neuronal apoptosis marker active caspase-3 had co-localizations with Vps4A. Additionaly, Vps4A knockdown in vitro specifically leads to decreasing neuronal apoptosis coupled with increased Akt phosphorylation. All datas suggested that Vps4A was involved in promoting neuronal apoptosis via inhibiting Akt phosphorylation after ICH.

Protective effects of phosphodiesterase-1 (PDE1) and ATP sensitive potassium (KATP) channel modulators against 3-nitropropionic acid induced behavioral and biochemical toxicities in experimental Huntington׳s disease.

PubMed

Gupta, Surbhi; Sharma, Bhupesh

2014-06-05

Huntington׳s disease (HD), a devastating neurodegenerative disorder, is characterized by weight loss, impairment of motor function, cognitive dysfunction, neuropsychiatric disturbances and striatal damage. Phosphodiesterase-1 (PDE1) has been implicated in various neurological diseases. Mitochondrial potassium channels in the brain take part in neuroprotection. This study has been structured to investigate the role of vinpocetine, a selective PDE1 inhibitor as well as nicorandil, selective ATP sensitive potassium (KATP) channel opener in 3-nitropropionic acid (3-NP) induced HD symptoms in rats. Systemic administration of 3-NP significantly, reduced body weight, impaired locomotion, grip strength and impaired cognition. 3-NP elicited marked oxidative stress in the brain (enhanced malondialdehyde-MDA, reduced glutathione-GSH content, superoxide dismutase-SOD and catalase-CAT), elevated brain acetylcholinesterase activity and inflammation (myeloperoxidase-MPO), with marked nitrosative stress (nitrite/nitrate) in the brain. 3-NP has also induced mitochondrial dysfunction (impaired mitochondrial NADH dehydrogenase-complex I, succinate dehydrogenase-complex II and cytochrome oxidase-complex IV) activities in the striatum of the rat. Tetrabenazine was used as a positive control. Treatment with vinpocetine, nicorandil and tetrabenazine ameliorated 3-NP induced reduction in body weight, impaired locomotion, grip strength and impaired cognition. Treatment with these drugs reduced brain striatum oxidative (MDA, GSH, SOD and CAT) and nitrosative (nitrite/nitrate) stress, acetylcholinesterase activity, inflammation and mitochondrial dysfunctions. These results indicate that vinpocetine, a selective PDE1 inhibitor and nicorandil, a KATP channel opener have attenuated 3-NP induced experimental HD. Hence, pharmacological modulation of PDE1 as well as KATP channels may be considered as potential research targets for mitigation of HD. Copyright © 2014 Elsevier B.V. All rights

PAK5, a New Brain-Specific Kinase, Promotes Neurite Outgrowth in N1E-115 Cells

PubMed Central

Dan, Chuntao; Nath, Niharika; Liberto, Muriel; Minden, Audrey

2002-01-01

We have characterized a new member of the mammalian PAK family of serine/threonine kinases, PAK5, which is a novel target of the Rho GTPases Cdc42 and Rac. The kinase domain and GTPase-binding domain (GBD) of PAK5 are most closely related in sequence to those of mammalian PAK4. Outside of these domains, however, PAK5 is completely different in sequence from any known mammalian proteins. PAK5 does share considerable sequence homology with the Drosophila MBT protein (for “mushroom body tiny”), however, which is thought to play a role in development of cells in Drosophila brain. Interestingly, PAK5 is highly expressed in mammalian brain and is not expressed in most other tissues. We have found that PAK5, like Cdc42, promotes the induction of filopodia. In N1E-115 neuroblastoma cells, expression of PAK5 also triggered the induction of neurite-like processes, and a dominant-negative PAK5 mutant inhibited neurite outgrowth. Expression of activated PAK1 caused no noticeable changes in these cells. An activated mutant of PAK5 had an even more dramatic effect than wild-type PAK5, indicating that the morphologic changes induced by PAK5 are directly related to its kinase activity. Although PAK5 activates the JNK pathway, dominant-negative JNK did not inhibit neurite outgrowth. In contrast, the induction of neurites by PAK5 was abolished by expression of activated RhoA. Previous work has shown that Cdc42 and Rac promote neurite outgrowth by a pathway that is antagonistic to Rho. Our results suggest, therefore, that PAK5 operates downstream to Cdc42 and Rac and antagonizes Rho in the pathway, leading to neurite development. PMID:11756552

Auxiliary KChIP4a Suppresses A-type K+ Current through Endoplasmic Reticulum (ER) Retention and Promoting Closed-state Inactivation of Kv4 Channels*

PubMed Central

Tang, Yi-Quan; Liang, Ping; Zhou, Jingheng; Lu, Yanxin; Lei, Lei; Bian, Xiling; Wang, KeWei

2013-01-01

In the brain and heart, auxiliary Kv channel-interacting proteins (KChIPs) co-assemble with pore-forming Kv4 α-subunits to form a native K+ channel complex and regulate the expression and gating properties of Kv4 currents. Among the KChIP1–4 members, KChIP4a exhibits a unique N terminus that is known to suppress Kv4 function, but the underlying mechanism of Kv4 inhibition remains unknown. Using a combination of confocal imaging, surface biotinylation, and electrophysiological recordings, we identified a novel endoplasmic reticulum (ER) retention motif, consisting of six hydrophobic and aliphatic residues, 12–17 (LIVIVL), within the KChIP4a N-terminal KID, that functions to reduce surface expression of Kv4-KChIP complexes. This ER retention capacity is transferable and depends on its flanking location. In addition, adjacent to the ER retention motif, the residues 19–21 (VKL motif) directly promote closed-state inactivation of Kv4.3, thus leading to an inhibition of channel current. Taken together, our findings demonstrate that KChIP4a suppresses A-type Kv4 current via ER retention and enhancement of Kv4 closed-state inactivation. PMID:23576435

Auxiliary KChIP4a suppresses A-type K+ current through endoplasmic reticulum (ER) retention and promoting closed-state inactivation of Kv4 channels.

PubMed

Tang, Yi-Quan; Liang, Ping; Zhou, Jingheng; Lu, Yanxin; Lei, Lei; Bian, Xiling; Wang, KeWei

2013-05-24

In the brain and heart, auxiliary Kv channel-interacting proteins (KChIPs) co-assemble with pore-forming Kv4 α-subunits to form a native K(+) channel complex and regulate the expression and gating properties of Kv4 currents. Among the KChIP1-4 members, KChIP4a exhibits a unique N terminus that is known to suppress Kv4 function, but the underlying mechanism of Kv4 inhibition remains unknown. Using a combination of confocal imaging, surface biotinylation, and electrophysiological recordings, we identified a novel endoplasmic reticulum (ER) retention motif, consisting of six hydrophobic and aliphatic residues, 12-17 (LIVIVL), within the KChIP4a N-terminal KID, that functions to reduce surface expression of Kv4-KChIP complexes. This ER retention capacity is transferable and depends on its flanking location. In addition, adjacent to the ER retention motif, the residues 19-21 (VKL motif) directly promote closed-state inactivation of Kv4.3, thus leading to an inhibition of channel current. Taken together, our findings demonstrate that KChIP4a suppresses A-type Kv4 current via ER retention and enhancement of Kv4 closed-state inactivation.

Aquaporin-4 polymorphisms and brain/body weight ratio in sudden infant death syndrome (SIDS).

PubMed

Studer, Jacqueline; Bartsch, Christine; Haas, Cordula

2014-07-01

Failure in the regulation of homeostatic water balance in the brain is associated with severe cerebral edema and increased brain weights and may also play an important role in the pathogenesis of sudden infant death syndrome (SIDS). We genotyped three single-nucleotide polymorphisms in the aquaporin-4 water channel-encoding gene (AQP4), which were previously shown to be associated with (i) SIDS in Norwegian infants (rs2075575), (ii) severe brain edema (rs9951307), and (iii) increased brain water permeability (rs3906956). We also determined whether the brain/body weight ratio is increased in SIDS infants compared with sex- and age-matched controls. Genotyping of the three AQP4 single-nucleotide polymorphisms was performed in 160 Caucasian SIDS infants and 181 healthy Swiss adults using a single-base extension method. Brain and body weights were measured during autopsy in 157 SIDS and 59 non-SIDS infants. No differences were detected in the allelic frequencies of the three AQP4 single-nucleotide polymorphisms between SIDS and adult controls. The brain/body weight ratio was similarly distributed in SIDS and non-SIDS infants. Variations in the AQP4 gene seem of limited significance as predisposing factors in Caucasian SIDS infants. Increased brain weights may only become evident in conjunction with environmental or other genetic risk factors.

Promoting Adaptive Behavior in Persons with Acquired Brain Injury, Extensive Motor and Communication Disabilities, and Consciousness Disorders

ERIC Educational Resources Information Center

Lancioni, Giulio E.; Singh, Nirbhay N.; O'Reilly, Mark F.; Sigafoos, Jeff; Belardinelli, Marta Olivetti; Buonocunto, Francesca; Sacco, Valentina; Navarro, Jorge; Lanzilotti, Crocifissa; De Tommaso, Marina; Megna, Marisa; Badagliacca, Francesco

2012-01-01

These two studies extended the evidence on the use of technology-based intervention packages to promote adaptive behavior in persons with acquired brain injury and multiple disabilities. Study I involved five participants in a minimally conscious state who were provided with intervention packages based on specific arrangements of optic, tilt, or…

Role of 2',3'-cyclic nucleotide 3'-phosphodiesterase in the renal 2',3'-cAMP-adenosine pathway.

PubMed

Jackson, Edwin K; Gillespie, Delbert G; Mi, Zaichuan; Cheng, Dongmei; Bansal, Rashmi; Janesko-Feldman, Keri; Kochanek, Patrick M

2014-07-01

Energy depletion increases the renal production of 2',3'-cAMP (a positional isomer of 3',5'-cAMP that opens mitochondrial permeability transition pores) and 2',3'-cAMP is converted to 2'-AMP and 3'-AMP, which in turn are metabolized to adenosine. Because the enzymes involved in this "2',3'-cAMP-adenosine pathway" are unknown, we examined whether 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) participates in the renal metabolism of 2',3'-cAMP. Western blotting and real-time PCR demonstrated expression of CNPase in rat glomerular mesangial, preglomerular vascular smooth muscle and endothelial, proximal tubular, thick ascending limb and collecting duct cells. Real-time PCR established the expression of CNPase in human glomerular mesangial, proximal tubular and vascular smooth muscle cells; and the level of expression of CNPase was greater than that for phosphodiesterase 4 (major enzyme for the metabolism of 3',5'-cAMP). Overexpression of CNPase in rat preglomerular vascular smooth muscle cells increased the metabolism of exogenous 2',3'-cAMP to 2'-AMP. Infusions of 2',3'-cAMP into isolated CNPase wild-type (+/+) kidneys increased renal venous 2'-AMP, and this response was diminished by 63% in CNPase knockout (-/-) kidneys, whereas the conversion of 3',5'-cAMP to 5'-AMP was similar in CNPase +/+ vs. -/- kidneys. In CNPase +/+ kidneys, energy depletion (metabolic poisons) increased kidney tissue levels of adenosine and its metabolites (inosine, hypoxanthine, xanthine, and uric acid) without accumulation of 2',3'-cAMP. In contrast, in CNPase -/- kidneys, energy depletion increased kidney tissue levels of 2',3'-cAMP and abolished the increase in adenosine and its metabolites. In conclusion, kidneys express CNPase, and renal CNPase mediates in part the renal 2',3'-cAMP-adenosine pathway. Copyright © 2014 the American Physiological Society.

Cytokine Immunopathogenesis of Enterovirus 71 Brain Stem Encephalitis

PubMed Central

Wang, Shih-Min; Lei, Huan-Yao; Liu, Ching-Chuan

2012-01-01

Enterovirus 71 (EV71) is one of the most important causes of herpangina and hand, foot, and mouth disease. It can also cause severe complications of the central nervous system (CNS). Brain stem encephalitis with pulmonary edema is the severe complication that can lead to death. EV71 replicates in leukocytes, endothelial cells, and dendritic cells resulting in the production of immune and inflammatory mediators that shape innate and acquired immune responses and the complications of disease. Cytokines, as a part of innate immunity, favor the development of antiviral and Th1 immune responses. Cytokines and chemokines play an important role in the pathogenesis EV71 brain stem encephalitis. Both the CNS and the systemic inflammatory responses to infection play important, but distinctly different, roles in the pathogenesis of EV71 pulmonary edema. Administration of intravenous immunoglobulin and milrinone, a phosphodiesterase inhibitor, has been shown to modulate inflammation, to reduce sympathetic overactivity, and to improve survival in patients with EV71 autonomic nervous system dysregulation and pulmonary edema. PMID:22956971

Human FGF1 promoter is active in ependymal cells and dopaminergic neurons in the brains of F1B-GFP transgenic mice.

PubMed

Chen, Mei-Shu; Lin, Hua-Kuo; Chiu, Hsun; Lee, Don-Ching; Chung, Yu-Fen; Chiu, Ing-Ming

2015-03-01

FGF1 is involved in multiple biological functions and exhibits the importance in neuroprotective effects. Our previous studies indicated that, in human brain and retina, the FGF1B promoter controlled the expression of FGF1. However, the exact function and regulation of FGF1 in brain is still unclear. Here, we generated F1B-GFP transgenic mice that expressed the GFP reporter gene under the control of human FGF1B promoter (-540 to +31). Using the fresh brain sections of F1B-GFP transgenic mice, we found that the F1B-GFP cells expressed strong fluorescent signals in the ventricular system throughout the brain. The results of immunohistochemistry further showed that two distinct populations of F1B-GFP(+) cells existed in the brains of F1B-GFP transgenic mice. We demonstrated that one population of F1B-GFP(+) cells was ependymal cells, which distributed along the entire ventricles, and the second population of F1B-GFP(+) cells was neuronal cells that projected their long processes into multiple directions in specific areas of the brain. The double labeling of F1B-GFP(+) cells and tyrosine hydroxylase indicated that a subpopulation of F1B-GFP(+) -neuronal cells was dopaminergic neurons. Importantly, these F1B-GFP(+) /TH(+) cells were distributed in the main dopaminergic neuronal groups including hypothalamus, ventral tegmental area, and raphe nuclei. These results suggested that human FGF1B promoter was active in ependymal cells, neurons, and a portion of dopaminergic neurons. Thus, the F1B-GFP transgenic mice provide an animal model not only for studying FGF1 gene expression in vivo but also for understanding the role of FGF1 contribution in neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease. © 2014 The Authors Developmental Neurobiology Published by Wiley Periodicals, Inc.

Identification of a Phosphodiesterase-Inhibiting Fraction from Roasted Coffee (Coffea arabica) through Activity-Guided Fractionation.

PubMed

Röhrig, Teresa; Liesenfeld, David; Richling, Elke

2017-05-17

Recent reports that coffee can significantly inhibit cAMP phosphodiesterases (PDEs) in vitro, as well as in vivo, have described another beneficial effect of coffee consumption. However, the PDE-inhibiting substances remain mostly unknown. We chose activity-guided fractionation and an in vitro test system to identify the coffee components that are responsible for PDE inhibition. This approach indicated that a fraction of melanoidins reveals strong PDE-inhibiting potential (IC 50 = 130 ± 42 μg/mL). These melanoidins were characterized as water-soluble, low-molecular weight melanoidins (<3 kDa) with a nitrogen content of 4.2% and a carbohydrate content lower than those of other melanoidins. Fractions containing known PDE inhibitors such as chlorogenic acids, alkylpyrazines, or trigonelline as well as N-caffeoyl-tryptophan and N-p-coumaroyl-tryptophan did not exert PDE-inhibiting activity. We also observed that the known PDE inhibitor caffeine does not contribute to the PDE-inhibiting effects of coffee.

Phosphodiesterase type 5 and cancers: progress and challenges

PubMed Central

Barone, Ines; Giordano, Cinzia; Bonofiglio, Daniela; Andò, Sebastiano; Catalano, Stefania

2017-01-01

Cancers are an extraordinarily heterogeneous collection of diseases with distinct genetic profiles and biological features that directly influence response patterns to various treatment strategies as well as clinical outcomes. Nevertheless, our growing understanding of cancer cell biology and tumor progression is gradually leading towards rational, tailored medical treatments designed to destroy cancer cells by exploiting the unique cellular pathways that distinguish them from normal healthy counterparts. Recently, inhibition of the activity of phosphodiesterase type 5 (PDE5) is emerging as a promising approach to restore normal intracellular cyclic guanosine monophosphate (cGMP) signalling, and thereby resulting into the activation of various downstream molecules to inhibit proliferation, motility and invasion of certain cancer cells. In this review, we present an overview of the experimental and clinical evidences highlighting the role of PDE5 in the pathogenesis and prevention of various malignancies. Current data are still not sufficient to draw conclusive statements for cancer patient management, but could provide further rational for testing PDE5-targeting drugs as anticancer agents in clinical settings. PMID:29228762

Stress-induced recruitment of bone marrow-derived monocytes to the brain promotes anxiety-like behavior.

PubMed

Wohleb, Eric S; Powell, Nicole D; Godbout, Jonathan P; Sheridan, John F

2013-08-21

Social stress is associated with altered immunity and higher incidence of anxiety-related disorders. Repeated social defeat (RSD) is a murine stressor that primes peripheral myeloid cells, activates microglia, and induces anxiety-like behavior. Here we show that RSD-induced anxiety-like behavior corresponded with an exposure-dependent increase in circulating monocytes (CD11b(+)/SSC(lo)/Ly6C(hi)) and brain macrophages (CD11b(+)/SSC(lo)/CD45(hi)). Moreover, RSD-induced anxiety-like behavior corresponded with brain region-dependent cytokine and chemokine responses involved with myeloid cell recruitment. Next, LysM-GFP(+) and GFP(+) bone marrow (BM)-chimeric mice were used to determine the neuroanatomical distribution of peripheral myeloid cells recruited to the brain during RSD. LysM-GFP(+) mice showed that RSD increased recruitment of GFP(+) macrophages to the brain and increased their presence within the perivascular space (PVS). In addition, RSD promoted recruitment of GFP(+) macrophages into the PVS and parenchyma of the prefrontal cortex, amygdala, and hippocampus of GFP(+) BM-chimeric mice. Furthermore, mice deficient in chemokine receptors associated with monocyte trafficking [chemokine receptor-2 knockout (CCR2(KO)) or fractalkine receptor knockout (CX3CR1(KO))] failed to recruit macrophages to the brain and did not develop anxiety-like behavior following RSD. Last, RSD-induced macrophage trafficking was prevented in BM-chimeric mice generated with CCR2(KO) or CX3CR1(KO) donor cells. These findings indicate that monocyte recruitment to the brain in response to social stress represents a novel cellular mechanism that contributes to the development of anxiety.

Stress-Induced Recruitment of Bone Marrow-Derived Monocytes to the Brain Promotes Anxiety-Like Behavior

PubMed Central

Wohleb, Eric S.; Powell, Nicole D.

2013-01-01

Social stress is associated with altered immunity and higher incidence of anxiety-related disorders. Repeated social defeat (RSD) is a murine stressor that primes peripheral myeloid cells, activates microglia, and induces anxiety-like behavior. Here we show that RSD-induced anxiety-like behavior corresponded with an exposure-dependent increase in circulating monocytes (CD11b+/SSClo/Ly6Chi) and brain macrophages (CD11b+/SSClo/CD45hi). Moreover, RSD-induced anxiety-like behavior corresponded with brain region-dependent cytokine and chemokine responses involved with myeloid cell recruitment. Next, LysM-GFP+ and GFP+ bone marrow (BM)-chimeric mice were used to determine the neuroanatomical distribution of peripheral myeloid cells recruited to the brain during RSD. LysM-GFP+ mice showed that RSD increased recruitment of GFP+ macrophages to the brain and increased their presence within the perivascular space (PVS). In addition, RSD promoted recruitment of GFP+ macrophages into the PVS and parenchyma of the prefrontal cortex, amygdala, and hippocampus of GFP+ BM-chimeric mice. Furthermore, mice deficient in chemokine receptors associated with monocyte trafficking [chemokine receptor-2 knockout (CCR2KO) or fractalkine receptor knockout (CX3CR1KO)] failed to recruit macrophages to the brain and did not develop anxiety-like behavior following RSD. Last, RSD-induced macrophage trafficking was prevented in BM-chimeric mice generated with CCR2KO or CX3CR1KO donor cells. These findings indicate that monocyte recruitment to the brain in response to social stress represents a novel cellular mechanism that contributes to the development of anxiety. PMID:23966702

Linking Brain Research to Art.

ERIC Educational Resources Information Center

Rettig, Perry R.; Rettig, Janet L.

1999-01-01

Reviews recent brain research in education. Provides five implications for teaching in art: (1) use emotion; (2) use different sense; (3) promote student self-direction; (4) enable social learning; and (5) encourage pattern finding. Describes two sample art units demonstrating how the five implications and art instruction can be integrated. (CMK)

The high-affinity phosphodiesterase PdeH regulates development and aflatoxin biosynthesis in Aspergillus flavus.

PubMed

Yang, Kunlong; Liu, Yinghang; Liang, Linlin; Li, Zhenguo; Qin, Qiuping; Nie, Xinyi; Wang, Shihua

2017-04-01

Cyclic AMP signaling controls a range of physiological processes in response to extracellular stimuli in organisms. Among the signaling cascades, cAMP, as a second messenger, is orchestrated by adenylate cyclase (biosynthesis) and cAMP phosphodiesterases (PDEs) (hydrolysis). In this study, we investigated the function of the high-affinity (PdeH) and low-affinity (PdeL) cAMP phosphodiesterase from the carcinogenic aflatoxin producing fungus Aspergillus flavus, and found that instead of PdeL, inactivation of PdeH exhibited a reduction in conidiation and sclerotia formation. However, the ΔpdeL/ΔpdeH mutant exhibited an enhanced phenotype defects, a similar phenotype defects to wild-type strain treated with exogenous cAMP. The activation of PKA activity was inhibited in the ΔpdeH or ΔpdeL/ΔpdeH mutant, both of whom exhibited increasing AF production. Further analysis by qRT-PCR revealed that pdeH had a high transcriptional level compared to pdeL in wild-type strain, and affected pdeL transcription. Green fluorescent protein tagging at the C-terminus of PDEs showed that PdeH-GFP is broadly compartmentalized in the cytosol, while PdeL-GFP localized mainly to the nucleus. Overall, our results indicated that PdeH plays a major role, but has overlapping function with PdeL, in vegetative growth, development and AF biosynthesis in A. flavus. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Brain-derived Neurotrophic Factor Promotes the Migration of Olfactory Ensheathing Cells Through TRPC Channels.

PubMed

Wang, Ying; Teng, Hong-Lin; Gao, Yuan; Zhang, Fan; Ding, Yu-Qiang; Huang, Zhi-Hui

2016-12-01

Olfactory ensheathing cells (OECs) are a unique type of glial cells with axonal growth-promoting properties in the olfactory system. Organized migration of OECs is essential for neural regeneration and olfactory development. However, the molecular mechanism of OEC migration remains unclear. In the present study, we examined the effects of brain-derived neurotrophic factor (BDNF) on OEC migration. Initially, the "scratch" migration assay, the inverted coverslip and Boyden chamber migration assays showed that BDNF could promote the migration of primary cultured OECs. Furthermore, BDNF gradient attracted the migration of OECs in single-cell migration assays. Mechanistically, TrkB receptor expressed in OECs mediated BDNF-induced OEC migration, and BDNF triggered calcium signals in OECs. Finally, transient receptor potential cation channels (TRPCs) highly expressed in OECs were responsible for BDNF-induced calcium signals, and required for BDNF-induced OEC migration. Taken together, these results demonstrate that BDNF promotes the migration of cultured OECs and an unexpected finding is that TRPCs are required for BDNF-induced OEC migration. GLIA 2016;64:2154-2165. © 2016 Wiley Periodicals, Inc.

Lineage-specific splicing of a brain-enriched alternative exon promotes glioblastoma progression

PubMed Central

Ferrarese, Roberto; Harsh, Griffith R.; Yadav, Ajay K.; Bug, Eva; Maticzka, Daniel; Reichardt, Wilfried; Dombrowski, Stephen M.; Miller, Tyler E.; Masilamani, Anie P.; Dai, Fangping; Kim, Hyunsoo; Hadler, Michael; Scholtens, Denise M.; Yu, Irene L.Y.; Beck, Jürgen; Srinivasasainagendra, Vinodh; Costa, Fabrizio; Baxan, Nicoleta; Pfeifer, Dietmar; von Elverfeldt, Dominik; Backofen, Rolf; Weyerbrock, Astrid; Duarte, Christine W.; He, Xiaolin; Prinz, Marco; Chandler, James P.; Vogel, Hannes; Chakravarti, Arnab; Rich, Jeremy N.; Carro, Maria S.; Bredel, Markus

2014-01-01

Tissue-specific alternative splicing is critical for the emergence of tissue identity during development, yet the role of this process in malignant transformation is undefined. Tissue-specific splicing involves evolutionarily conserved, alternative exons that represent only a minority of the total alternative exons identified. Many of these conserved exons have functional features that influence signaling pathways to profound biological effect. Here, we determined that lineage-specific splicing of a brain-enriched cassette exon in the membrane-binding tumor suppressor annexin A7 (ANXA7) diminishes endosomal targeting of the EGFR oncoprotein, consequently enhancing EGFR signaling during brain tumor progression. ANXA7 exon splicing was mediated by the ribonucleoprotein PTBP1, which is normally repressed during neuronal development. PTBP1 was highly expressed in glioblastomas due to loss of a brain-enriched microRNA (miR-124) and to PTBP1 amplification. The alternative ANXA7 splicing trait was present in precursor cells, suggesting that glioblastoma cells inherit the trait from a potential tumor-initiating ancestor and that these cells exploit this trait through accumulation of mutations that enhance EGFR signaling. Our data illustrate that lineage-specific splicing of a tissue-regulated alternative exon in a constituent of an oncogenic pathway eliminates tumor suppressor functions and promotes glioblastoma progression. This paradigm may offer a general model as to how tissue-specific regulatory mechanisms can reprogram normal developmental processes into oncogenic ones. PMID:24865424

The inhibitory effect of convulsant agents on the enzyme in brain which inactivates nerveside.

PubMed

Toh, C C

1969-07-01

1. An enzyme which can be extracted from brain inactivates nerveside in the optimum pH range 5.8-7.0.2. The polybasic acids trypan blue and its analogue trypan red, bromphenol blue and its analogue bromthymol blue at concentrations of 0.22 mM and ethylenediaminetetra-acetic acid (EDTA) at a concentration of 1 mM are strong inhibitors of the enzyme.3. Penicillin which is a monobasic carboxylic acid also inhibits the enzyme but only if concentrations as high as 3.6 mM are used. The antibiotic streptomycin which is a basic substance does not inhibit the enzyme.4. Caffeine at a concentration of 7.2 mM only weakly inhibits the enzyme.5. Chymotrypsin and wheat germ acid phosphatase also inactivate nerveside at pH 5.9 and are inhibited by the acidic dyes and penicillin. EDTA inhibits wheat germ phosphatase but activates chymotrypsin.6. Inactivation of nerveside by the brain enzyme and by wheat germ phosphatase is different from the action of chymotrypsin. Nerveside solutions incubated with chymotrypsin completely lose all biological activity whereas if incubation is carried out with either the brain enzyme or wheat germ acid phosphatase a residual biological activity remains even when the concentration of these two enzymes is increased. This residual biological activity is due to a peptide as it is destroyed by chymotrypsin.7. The manner in which nerveside is inactivated by the brain enzyme is uncertain as the preparation of the latter contained phosphodiesterase and protease activities which were similarly inhibited by the acid dyes, penicillin and EDTA.8. Pentylenetetrazole, picrotoxin, strychnine and tetanus toxin do not inhibit the brain enzyme.9. The nerveside-inactivating enzyme is not identical with the Substance P-inactivating enzyme in brain as the former is inhibited by EDTA while the latter is not.

[Expression of aquaporin-4 during brain edema in rats with thioacetamide-induced acute encephalopathy].

PubMed

Wang, Li-Qing; Zhu, Sheng-Mei; Zhou, Heng-Jun; Pan, Cai-Fei

2011-09-27

To investigate the expression of aquaporin-4 (AQP4) during brain edema in rats with thioacetamide-induced acute liver failure and encephalopathy. The rat model of acute hepatic failure and encephalopathy was induced by intraperitoneal injection of thioacetamide (TAA) at a 24-hour interval for 2 consecutive days. Thirty-two SD rats were randomly divided into the model group (n = 24) and the control group (normal saline, n = 8). And then the model group was further divided into 3 subgroups by the timepoint of decapitation: 24 h (n = 8), 48 h (n = 8) and 60 h (n = 8). Then we observed their clinical symptoms and stages of HE, indices of liver function and ammonia, liver histology and brain water content. The expression of AQP4 protein in brain tissues was measured with Western blot and the expression of AQP4mRNA with RT-PCR (reverse transcription-polymerase chain reaction). Typical clinical manifestations of hepatic encephalopathy occurred in all TAA-administrated rats. The model rats showed the higher indices of ALT (alanine aminotransferase), AST (aspartate aminotransferase), TBIL (total bilirubin) and ammonia than the control rats (P < 0.05). The brain water content was significantly elevated in TAA-administrated rats compared with the control (P < 0.05). The expressions of AQP4 protein and mRNA in brain tissues significantly increased in TAA-administrated rats (P < 0.05). In addition, the expressions of AQP4 protein and mRNA were positively correlated with brain water content (r = 0.536, P < 0.01; r = 0.566, P = 0.01). The high expression of AQP4 in rats with TAA-induced acute liver failure and encephalopathy plays a significant role during brain edema. AQP4 is one of the molecular mechanisms for the occurrence of brain edema in hepatic encephalopathy.

Deep-brain magnetic stimulation promotes adult hippocampal neurogenesis and alleviates stress-related behaviors in mouse models for neuropsychiatric disorders

PubMed Central

2014-01-01

Background Repetitive Transcranial Magnetic Stimulation (rTMS)/ Deep-brain Magnetic Stimulation (DMS) is an effective therapy for various neuropsychiatric disorders including major depression disorder. The molecular and cellular mechanisms underlying the impacts of rTMS/DMS on the brain are not yet fully understood. Results Here we studied the effects of deep-brain magnetic stimulation to brain on the molecular and cellular level. We examined the adult hippocampal neurogenesis and hippocampal synaptic plasticity of rodent under stress conditions with deep-brain magnetic stimulation treatment. We found that DMS promotes adult hippocampal neurogenesis significantly and facilitates the development of adult new-born neurons. Remarkably, DMS exerts anti-depression effects in the learned helplessness mouse model and rescues hippocampal long-term plasticity impaired by restraint stress in rats. Moreover, DMS alleviates the stress response in a mouse model for Rett syndrome and prolongs the life span of these animals dramatically. Conclusions Deep-brain magnetic stimulation greatly facilitates adult hippocampal neurogenesis and maturation, also alleviates depression and stress-related responses in animal models. PMID:24512669

Sexual life of Japanese patients with erectile dysfunction taking phosphodiesterase type 5 inhibitors: an Internet survey using the Psychological and Interpersonal Relationship Scales-Short Form questionnaire.

PubMed

Tsujimura, Akira; Kiuchi, Hiroshi; Soda, Tetsuji; Takezawa, Kentaro; Okuda, Hidenobu; Fukuhara, Shinichiro; Takao, Tetsuya; Nonomura, Norio; Miyagawa, Yasushi

2014-08-01

To investigate details of sexual function of erectile dysfunction in Japanese patients taking phosphodiesterase type 5 inhibitors. A Japanese version of the Psychological and Interpersonal Relationship Scales-Short Form was used to carry out a nationwide survey using the Internet. A total of 556 erectile dysfunction patients (age 30-70 years) who had been prescribed a phosphodiesterase type 5 inhibitor and had attempted sexual intercourse within the past 6 months were included in this survey. Scores were compared in relation to the phosphodiesterase type 5 inhibitors most frequently taken within the past 6 months. In the subdomains of self-confidence and spontaneity of the Psychological and Interpersonal Relationship Scales-Short Form, scores for vardenafil and tadalafil were significantly higher than those for sildenafil. In the subdomain of time concern of the Psychological and Interpersonal Relationship Scales-Short Form, the score for tadalafil was significantly lower than that for others. Our findings support the hypothesis that Japanese patients with erectile dysfunction have high sexual self-confidence, spontaneity and low time concerns when taking tadalafil. These characteristics of tadalafil could be associated with high patient satisfaction and high preference. © 2014 The Japanese Urological Association.

Aquaporin-4 deletion in mice reduces encephalopathy and brain edema in experimental acute liver failure.

PubMed

Rama Rao, Kakulavarapu V; Verkman, A S; Curtis, Kevin M; Norenberg, Michael D

2014-03-01

Brain edema and associated astrocyte swelling leading to increased intracranial pressure are hallmarks of acute liver failure (ALF). Elevated blood and brain levels of ammonia have been implicated in the development of brain edema in ALF. Cultured astrocytes treated with ammonia have been shown to undergo cell swelling and such swelling was associated with an increase in the plasma membrane expression of aquaporin-4 (AQP4) protein. Further, silencing the AQP4 gene in cultured astrocytes was shown to prevent the ammonia-induced cell swelling. Here, we examined the evolution of brain edema in AQP4-null mice and their wild type counterparts (WT-mice) in different models of ALF induced by thioacetamide (TAA) or acetaminophen (APAP). Induction of ALF with TAA or APAP significantly increased brain water content in WT mice (by 1.6% ± 0.3 and 2.3 ± 0.4%, respectively). AQP4 protein was significantly increased in brain plasma membranes of WT mice with ALF induced by either TAA or APAP. In contrast to WT-mice, brain water content did not increase in AQP4-null mice. Additionally, AQP4-null mice treated with either TAA or APAP showed a remarkably lesser degree of neurological deficits as compared to WT mice; the latter displayed an inability to maintain proper gait, and demonstrated a markedly reduced exploratory behavior, with the mice remaining in one corner of the cage with its head tilted downwards. These results support a central role of AQP4 in the brain edema associated with ALF. Published by Elsevier Inc.

Aquaporin-4 Deletion in Mice Reduces Encephalopathy and Brain Edema in Experimental Acute Liver Failure

PubMed Central

Rama Rao, Kakulavarapu V.; Verkman, A. S.; Curtis, Kevin M.; Norenberg, Michael D.

2014-01-01

Brain edema and associated astrocyte swelling leading to increased intracranial pressure are hallmarks of acute liver failure (ALF). Elevated blood and brain levels of ammonia have been implicated in the development of brain edema in ALF. Cultured astrocytes treated with ammonia have been shown to undergo cell swelling and such swelling was associated with an increase in the plasma membrane expression of aquaporin-4 (AQP4) protein. Further, silencing the AQP4 gene in cultured astrocytes was shown to prevent the ammonia-induced cell swelling. Here, we examined the evolution of brain edema in AQP4-null mice and their wild type counterparts (WT-mice) in different models of ALF induced by thioacetamide (TAA) or acetaminophen (APAP). Induction of ALF with TAA or APAP significantly increased brain water content in WT mice (by 1.6 ± 0.3 and 2.3 ± 0.4 %, respectively). AQP4 protein was significantly increased in brain plasma membranes of WT mice with ALF induced by either TAA or APAP. In contrast to WT-mice, brain water content did not increase in AQP4-null mice. Additionally, AQP4-null mice treated with either TAA or APAP showed a remarkably lesser degree of neurological deficits as compared to WT mice; the latter displayed an inability to maintain proper gait, and demonstrated a markedly reduced exploratory behavior, with the mice remaining in one corner of the cage with its head tilted downwards. These results support a central role of AQP4 in the brain edema associated with ALF. PMID:24321433

Tegumental Phosphodiesterase SmNPP-5 Is a Virulence Factor for Schistosomes ▿

PubMed Central

Bhardwaj, Rita; Krautz-Peterson, Greice; Da'dara, Akram; Tzipori, Saul; Skelly, Patrick J.

2011-01-01

The intravascular trematode Schistosoma mansoni is a causative agent of schistosomiasis, a disease that constitutes a major health problem globally. In this study we cloned and characterized the schistosome tegumental phosphodiesterase SmNPP-5 and evaluated its role in parasite virulence. SmNPP-5 is a 52.5-kDa protein whose gene is rapidly turned on in the intravascular parasitic life stages, following invasion of the definitive host. Highest expression is found in mated adult males. As revealed by immunofluorescence analysis, SmNPP-5 protein is found prominently in the dorsal surface of the tegument of males. Localization by immuno-electron microscopy illustrates a unique pattern of immunogold-labeled SmNPP-5 within the tegument; some immunogold particles are scattered throughout the tissue, but many are clustered in tight arrays. To determine the importance of the protein for the parasites, RNA interference (RNAi) was employed to knock down expression of the SmNPP-5-encoding gene in schistosomula and adult worms. Both quantitative real-time PCR (qRT-PCR) and Western blotting confirmed successful and robust gene suppression. In addition, the suppression and the ectolocalization of this enzyme in live parasites were evident because of a significantly impaired ability of the suppressed parasites to hydrolyze exogenously added phosphodiesterase substrate p-nitrophenyl 5′-dTMP (p-Nph-5′-TMP). The effects of suppressing expression of the SmNPP-5 gene in vivo were tested by injecting parasites into mice. It was found that, unlike controls, parasites whose SmNPP-5 gene was demonstrably suppressed at the time of host infection were greatly impaired in their ability to establish infection. These results demonstrate that SmNPP-5 is a virulence factor for schistosomes. PMID:21825060

A single acute hepatotoxic dose of CCl4 causes oxidative stress in the rat brain.

PubMed

Ritesh, K R; Suganya, A; Dileepkumar, H V; Rajashekar, Y; Shivanandappa, T

2015-01-01

Carbon tetrachloride (CCl 4 ), a hepatotoxic agent is widely used to study the toxic mechanisms in experimental animals. We have investigated whether oxidative stress is induced in the brain at a single hepatotoxic dosage (1 ml/kg bw) of CCl 4 . Increased lipid peroxidation (LPO), protein carbonyls (PC) content and glutathione (GSH) depletion were observed in the brain regions of rats treated with CCl 4 which was higher than that of liver. A drastic reduction in the activity of glutathione- S -transferase (GST) was seen in the brain regions which was higher than that of liver. Similarly, activities of glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), NADH- and NADPH-dehydrogenase were reduced in the brain regions similar to that of liver. Higher induction of oxidative stress in the brain compared to that of liver implies vulnerability of the brain for CCl 4 neurotoxicity. Our study shows that a single hepatotoxic dose of CCl 4 is equally neurotoxic to rats.

Combining neurotrophin-transduced schwann cells and rolipram to promote functional recovery from subacute spinal cord injury.

PubMed

Flora, Govinder; Joseph, Gravil; Patel, Samik; Singh, Amanpreet; Bleicher, Drew; Barakat, David J; Louro, Jack; Fenton, Stephanie; Garg, Maneesh; Bunge, Mary Bartlett; Pearse, Damien D

2013-01-01

Following spinal cord injury (SCI), both an inhibitory environment and lack of intrinsic growth capacity impede axonal regeneration. In a previous study, prevention of cyclic adenosine monophosphate (AMP) hydrolysis by the phosphodiesterase-4 inhibitor rolipram, in combination with Schwann cell (SC) grafts, promoted significant supraspinal and proprioceptive fiber growth and/or sparing and improved locomotion. In another study, transplanted SCs transduced to generate a bifunctional neurotrophin (D15A) led to significant increases in graft SCs and axons, including supraspinal and myelinated axons. Here we studied the growth and myelination of local and supraspinal axons and functional outcome following the combination of rolipram administration and neurotrophin-transduced SC implantation after SCI. Rolipram was administered subcutaneously for 4 weeks immediately after contusion at vertebral T8 (25.0-mm weight drop, MASCIS impactor). GFP or GFP-D15A-transduced SCs were injected into the injury epicenter 1 week after SCI. GFP-D15A SC grafts and GFP SC grafts with rolipram contained significantly more serotonergic fibers compared to GFP SCs. SC myelinated axons were increased significantly in GFP SC with rolipram-treated animals compared to animals receiving SCI alone. Rolipram administered with either GFP or GFP-D15A SCs significantly increased numbers of brain stem-derived axons below the lesion/implant area and improved hindlimb function. Compared to the single treatments, the combination led to the largest SC grafts, the highest numbers of serotonergic fibers in the grafts, and increased numbers of axons from the reticular formation below the lesion/implant area and provided the greatest improvement in hindlimb function. These findings demonstrate the therapeutic potential for a combination therapy involving the maintenance of cyclic AMP levels and neurotrophin-transduced SCs to repair the subacutely injured spinal cord.

Improving whole brain structural MRI at 4.7 Tesla using 4 irregularly shaped receiver coils.

PubMed

Carmichael, David W; Thomas, David L; De Vita, Enrico; Fernández-Seara, Maria A; Chhina, Navjeet; Cooper, Mark; Sunderland, Colin; Randell, Chris; Turner, Robert; Ordidge, Roger J

2006-09-01

Both higher magnetic field strengths (> or =3 T) and multiple receiver "array coils" can provide increased signal-to-noise ratio (SNR) for MRI. This increase in SNR can be used to obtain images with higher resolution, enabling better visualisation of structures within the human brain. However, high field strength systems also suffer from increased B(1) non-uniformity and increased power deposition, reaching specific absorption rate (SAR) limits more quickly. For these problems to be mitigated, a careful choice of both the pulse sequence design and transmit RF coil is required. This paper describes the use of a prototype array coil consisting of 4 irregularly shaped coils within a standard configuration for neuroimaging at 4.7 T (a head transmit/receive volume coil to minimise SAR and a head gradient insert for maximum gradient performance). With a fast spin echo (FSE) pulse sequence optimised for 4.7 T, this provides dramatically increased quality and resolution over a large brain volume. Using the array coil, a SNR improvement relative to the volume coil of 1-1.5 times in central brain areas and 2-3 times in cortical regions was obtained. Array coil images with a resolution of 352 x 352 x 2000 mum had a SNR of 16.0 to 26.2 in central regions and 19.9 to 34.8 in cortical areas. Such images easily demonstrate cortical myeloarchitecture, while still covering most of the brain in a approximately 12 min scan.

Phosphodiesterase 2A Inhibitor TAK-915 Ameliorates Cognitive Impairments and Social Withdrawal in N-Methyl-d-Aspartate Receptor Antagonist-Induced Rat Models of Schizophrenia.

PubMed

Nakashima, Masato; Imada, Haruka; Shiraishi, Eri; Ito, Yuki; Suzuki, Noriko; Miyamoto, Maki; Taniguchi, Takahiko; Iwashita, Hiroki

2018-04-01

The pathophysiology of schizophrenia has been associated with glutamatergic dysfunction. Modulation of the glutamatergic signaling pathway, including N -methyl-d-aspartate (NMDA) receptors, can provide a new therapeutic target for schizophrenia. Phosphodiesterase 2A (PDE2A) is highly expressed in the forebrain, and is a dual substrate enzyme that hydrolyzes both cAMP and cGMP, which play pivotal roles as intracellular second messengers downstream of NMDA receptors. Here we characterize the in vivo pharmacological profile of a selective and brain-penetrant PDE2A inhibitor, ( N -{(1 S )-1-[3-fluoro-4-(trifluoromethoxy)phenyl]-2-methoxyethyl}-7-methoxy-2-oxo-2,3-dihydropyrido[2,3- b ]pyrazine-4(1 H )-carboxamide) (TAK-915) as a novel treatment of schizophrenia. Oral administration of TAK-915 at 3 and 10 mg/kg significantly increased cGMP levels in the frontal cortex, hippocampus, and striatum of rats. TAK-915 at 10 mg/kg significantly upregulated the phosphorylation of α -amino-3-hydroxy-5-methylisoxazole-4-proprionic acid receptor subunit GluR1 in the rat hippocampus. TAK-915 at 3 and 10 mg/kg significantly attenuated episodic memory deficits induced by the NMDA receptor antagonist (+)-MK-801 hydrogen maleate (MK-801) in the rat passive avoidance test. TAK-915 at 10 mg/kg significantly attenuated working memory deficits induced by MK-801 in the rat radial arm maze test. Additionally, TAK-915 at 10 mg/kg prevented subchronic phencyclidine-induced social withdrawal in social interaction in rats. In contrast, TAK-915 did not produce antipsychotic-like activity; TAK-915 had little effect on MK-801- or methamphetamine-induced hyperlocomotion in rats. These results suggest that TAK-915 has a potential to ameliorate cognitive impairments and social withdrawal in schizophrenia. Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.

[Post-ischemic innate immunity and its application for novel therapeutic strategy targeting brain inflammation].

PubMed

Ito, Minako; Kondo, Taisuke; Shichita, Takashi; Yoshimura, Akihiko

2013-07-01

Stroke or brain ischemia is one of the major causes of death and disability worldwide. Post-ischemic inflammation is an essential step in the progression of brain ischemia-reperfusion injury. In a mouse stroke model, we have reported that IL-23 produced from infiltrating macrophages induces IL-17 producing T cells. IL-17 is mainly produced from gammadeltaT cells and promotes delayed (day 3-4) ischemic brain damage. We also demonstrated that peroxiredoxin (Prx) family proteins released extracellularly from necrotic brain cells induce expression of inflammatory cytokines including IL-23 in macrophages through activation of Toll-like receptor 2(TLR2) and TLR4, thereby promoting neural cell death. We thus propose that regulation of the IL-23-IL-17 axis including gammadeltaT cells, macrophages, and extracellular Prxs could be a potent neuroprotective tool.

Mutation of the cyclic di-GMP phosphodiesterase gene in Burkholderia lata SK875 attenuates virulence and enhances biofilm formation.

PubMed

Jung, Hae-In; Kim, Yun-Jung; Lee, Yun-Jung; Lee, Hee-Soo; Lee, Jung-Kee; Kim, Soo-Ki

2017-10-01

Burkholderia sp. is a gram-negative bacterium that commonly exists in the environment, and can cause diseases in plants, animals, and humans. Here, a transposon mutant library of a Burkholderia lata isolate from a pig with swine respiratory disease in Korea was screened for strains showing attenuated virulence in Caenorhabditis elegans. One such mutant was obtained, and the Tn5 insertion junction was mapped to rpfR, a gene encoding a cyclic di-GMP phosphodiesterase that functions as a receptor. Mutation of rpfR caused a reduction in growth on CPG agar and swimming motility as well as a rough colony morphology on Congo red agar. TLC analysis showed reduced AHL secretion, which was in agreement with the results from plate-based and bioluminescence assays. The mutant strain produced significantly more biofilm detected by crystal violet staining than the parent strain. SEM of the mutant strain clearly showed that the overproduced biofilm contained a filamentous structure. These results suggest that the cyclic di-GMP phosphodiesterase RpfR plays an important role in quorum sensing modulation of the bacterial virulence and biofilm formation.

Safety and efficacy of topical E6005, a phosphodiesterase 4 inhibitor, in Japanese adult patients with atopic dermatitis: results of a randomized, vehicle-controlled, multicenter clinical trial.

PubMed

Furue, Masutaka; Kitahara, Yasumi; Akama, Hideto; Hojo, Seiichiro; Hayashi, Nobukazu; Nakagawa, Hidemi

2014-07-01

The safety and efficacy of topical E6005, a novel phosphodiesterase 4 inhibitor, in Japanese adults with atopic dermatitis were evaluated. A total of 78 patients were randomized to receive either the 0.2% E6005 ointment or vehicle control (without E6005) at an allocation ratio of 2:1. The randomization phase of 4 weeks was followed by an extension phase of 8 weeks. In the extension phase, all 67 subjects who completed the randomization phase were treated with 0.2% E6005 ointment. The 4-week application of topical E6005 twice daily was safe and well tolerated. The safety profile for up to 12 weeks was similar to that for the first 4 weeks. No deaths or other serious adverse effects were observed during the entire study period of 12 weeks. Plasma E6005 was undetectable in all subjects at all sampling points while very low plasma concentrations of an E6005 metabolite were detected in 47% of subjects receiving E6005 treatment. At the end of week 4, Eczema Area and Severity Index (EASI), Severity Scoring Atopic Dermatitis (SCORAD)-objective, SCORAD-C (visual analog scales for pruritus and sleep loss), itch Behavioral Rating Scale, and the severity of the targeted eczematous lesions in the topical E6005 group showed trends toward improvement compared with those in the vehicle group (not statistically significant). However, the group receiving topical E6005 for 12 weeks showed significant score reductions from baselines for EASI (P = 0.030), SCORAD-objective (P < 0.001) and SCORAD-C (P = 0.038). These results further support the development of topical E6005 for the treatment of atopic dermatitis. © 2014 Japanese Dermatological Association.

Identification of a set of genes showing regionally enriched expression in the mouse brain

PubMed Central

D'Souza, Cletus A; Chopra, Vikramjit; Varhol, Richard; Xie, Yuan-Yun; Bohacec, Slavita; Zhao, Yongjun; Lee, Lisa LC; Bilenky, Mikhail; Portales-Casamar, Elodie; He, An; Wasserman, Wyeth W; Goldowitz, Daniel; Marra, Marco A; Holt, Robert A; Simpson, Elizabeth M; Jones, Steven JM

2008-01-01

Background The Pleiades Promoter Project aims to improve gene therapy by designing human mini-promoters (< 4 kb) that drive gene expression in specific brain regions or cell-types of therapeutic interest. Our goal was to first identify genes displaying regionally enriched expression in the mouse brain so that promoters designed from orthologous human genes can then be tested to drive reporter expression in a similar pattern in the mouse brain. Results We have utilized LongSAGE to identify regionally enriched transcripts in the adult mouse brain. As supplemental strategies, we also performed a meta-analysis of published literature and inspected the Allen Brain Atlas in situ hybridization data. From a set of approximately 30,000 mouse genes, 237 were identified as showing specific or enriched expression in 30 target regions of the mouse brain. GO term over-representation among these genes revealed co-involvement in various aspects of central nervous system development and physiology. Conclusion Using a multi-faceted expression validation approach, we have identified mouse genes whose human orthologs are good candidates for design of mini-promoters. These mouse genes represent molecular markers in several discrete brain regions/cell-types, which could potentially provide a mechanistic explanation of unique functions performed by each region. This set of markers may also serve as a resource for further studies of gene regulatory elements influencing brain expression. PMID:18625066

Identification of a set of genes showing regionally enriched expression in the mouse brain.

PubMed

D'Souza, Cletus A; Chopra, Vikramjit; Varhol, Richard; Xie, Yuan-Yun; Bohacec, Slavita; Zhao, Yongjun; Lee, Lisa L C; Bilenky, Mikhail; Portales-Casamar, Elodie; He, An; Wasserman, Wyeth W; Goldowitz, Daniel; Marra, Marco A; Holt, Robert A; Simpson, Elizabeth M; Jones, Steven J M

2008-07-14

The Pleiades Promoter Project aims to improve gene therapy by designing human mini-promoters (< 4 kb) that drive gene expression in specific brain regions or cell-types of therapeutic interest. Our goal was to first identify genes displaying regionally enriched expression in the mouse brain so that promoters designed from orthologous human genes can then be tested to drive reporter expression in a similar pattern in the mouse brain. We have utilized LongSAGE to identify regionally enriched transcripts in the adult mouse brain. As supplemental strategies, we also performed a meta-analysis of published literature and inspected the Allen Brain Atlas in situ hybridization data. From a set of approximately 30,000 mouse genes, 237 were identified as showing specific or enriched expression in 30 target regions of the mouse brain. GO term over-representation among these genes revealed co-involvement in various aspects of central nervous system development and physiology. Using a multi-faceted expression validation approach, we have identified mouse genes whose human orthologs are good candidates for design of mini-promoters. These mouse genes represent molecular markers in several discrete brain regions/cell-types, which could potentially provide a mechanistic explanation of unique functions performed by each region. This set of markers may also serve as a resource for further studies of gene regulatory elements influencing brain expression.

Oral therapies for pulmonary arterial hypertension: endothelin receptor antagonists and phosphodiesterase-5 inhibitors.

PubMed

Channick, Richard; Preston, Iona; Klinger, James R

2013-12-01

The development of orally active pulmonary vasodilators has been a major breakthrough in the treatment of pulmonary arterial hypertension (PAH). Orally active medications greatly enhanced patient access to PAH treatment and increased an interest in the diagnosis and treatment of this disease that still continues. Four different orally active drugs are currently available for the treatment of PAH and several more are undergoing evaluation. This article discusses the mechanisms by which endothelin receptor antagonists and phosphodiesterase-5 inhibitors mitigate pulmonary hypertensive responses, and reviews the most recent data concerning their efficacy and limitations in the treatment of PAH. Copyright © 2013 Elsevier Inc. All rights reserved.

125 Brain Games for Babies: Simple Games To Promote Early Brain Development.

ERIC Educational Resources Information Center

Silberg, Jackie

Scientists believe that the stimulation that infants and young children receive determines which synapses form in the brain. This book presents 125 games for infants from birth to 12 months and is designed to nurture brain development. The book is organized chronologically in 3-month increments. Each game description includes information from…

East Indian Sandalwood Oil Is a Phosphodiesterase Inhibitor: A New Therapeutic Option in the Treatment of Inflammatory Skin Disease.

PubMed

Sharma, Manju; Levenson, Corey; Browning, John C; Becker, Emily M; Clements, Ian; Castella, Paul; Cox, Michael E

2018-01-01

Cyclic adenosine monophosphate phosphodiesterases (PDEs) regulate pro-inflammatory cytokine production. One isoform, PDE4, is overactive in chronic relapsing inflammatory skin diseases: psoriasis and eczema/atopic dermatitis, and in several cancers. East Indian sandalwood oil (EISO) has significant anti-inflammatory properties. Here, we report that 75% of pediatric eczema/atopic dermatitis patients treated with topical EISO formulations achieved a >50% reduction in their Eczema Area and Severity Index score. EISO treatment of a psoriasis model reduced PDE4 expression and reversed histopathology. EISO directly inhibited PDE enzymatic activity in vitro . In lipopolysaccharide-stimulated human dermal fibroblast, BEAS-2B, A549, and THP-1 cells, EISO suppressed total cellular PDE activity, PDE4, and 7 transcript levels, nuclear factor kappa B (NF-κB) activation, and pro-inflammatory cytokines/chemokine production. These results suggest that EISO anti-inflammatory activity is mediated through suppressing PDE activity, thus facilitating cAMP-regulated inhibition of NF-κB and indicate EISO as an attractive natural therapeutic for chronic and acute inflammatory disorders.

East Indian Sandalwood Oil Is a Phosphodiesterase Inhibitor: A New Therapeutic Option in the Treatment of Inflammatory Skin Disease

PubMed Central

Sharma, Manju; Levenson, Corey; Browning, John C.; Becker, Emily M.; Clements, Ian; Castella, Paul; Cox, Michael E.

2018-01-01

Cyclic adenosine monophosphate phosphodiesterases (PDEs) regulate pro-inflammatory cytokine production. One isoform, PDE4, is overactive in chronic relapsing inflammatory skin diseases: psoriasis and eczema/atopic dermatitis, and in several cancers. East Indian sandalwood oil (EISO) has significant anti-inflammatory properties. Here, we report that 75% of pediatric eczema/atopic dermatitis patients treated with topical EISO formulations achieved a >50% reduction in their Eczema Area and Severity Index score. EISO treatment of a psoriasis model reduced PDE4 expression and reversed histopathology. EISO directly inhibited PDE enzymatic activity in vitro. In lipopolysaccharide-stimulated human dermal fibroblast, BEAS-2B, A549, and THP-1 cells, EISO suppressed total cellular PDE activity, PDE4, and 7 transcript levels, nuclear factor kappa B (NF-κB) activation, and pro-inflammatory cytokines/chemokine production. These results suggest that EISO anti-inflammatory activity is mediated through suppressing PDE activity, thus facilitating cAMP-regulated inhibition of NF-κB and indicate EISO as an attractive natural therapeutic for chronic and acute inflammatory disorders. PMID:29593534

AMD3100 inhibits brain-specific metastasis in lung cancer via suppressing the SDF-1/CXCR4 axis and protecting blood-brain barrier

PubMed Central

Li, Hongru; Chen, Yusheng; Xu, Nengluan; Yu, Meie; Tu, Xunwei; Chen, Zhengwei; Lin, Ming; Xie, Baosong; Fu, Jianjun; Han, Lili

2017-01-01

Lung cancer represents the foremost cause of cancer-related mortality in both men and women throughout the world. Metastasis to the brain constitutes a major problem in the management of patients with lung cancer. However, the mechanism of brain-specific metastasis in lung cancer has not been fully elucidated. Chemokines and their receptors have emerged as attractive targets regulating the cancer metastasis. It has been discovered that the stromal cell-derived factor 1 (SDF-1)/CXCR4 axis plays a critical role in determining the metastatic destination of tumor cells. In this study, strong expression of SDF-1 was observed in highly metastatic brain tissues, and CXCR4 overexpressed in PC-9 lung cancer cells and tumor foci. Therefore, we chose to block SDF-1/CXCR4 axis with AMD3100, which led to the increased tight junction protein level, less damage, and decreased permeability of blood-brain barrier (BBB). Consequently, the process of lung cancer metastasis to the brain was significantly slowed down. These findings were further validated by in vivo experiments, which showed that AMD3100 can effectively inhibit lung cancer brain metastasis and extend the survival of nude mice model, suggesting that it is a potential drug candidate for inhibiting the lung cancer metastasis to brain. These findings provided valuable information for designing new therapeutic strategies for the treatment of lung cancer brain metastasis. PMID:29312481

Phosphodiesterase 5 Inhibition Attenuates Cerebral Vasospasm and Improves Functional Recovery after Experimental Subarachnoid Hemorrhage

PubMed Central

Han, Byung Hee; Vellimana, Ananth Kesav; Zhou, Meng-Liang; Milner, Eric; Zipfel, Gregory Joseph

2014-01-01

Background Cerebral vasospasm is an independent predictor of poor outcome after subarachnoid hemorrhage (SAH). The nitric oxide-cyclic GMP (NO-cGMP) vasodilatory pathway is strongly implicated in its pathophysiology. Preliminary studies suggest that phosphodiesterase 5 (PDE5) – an enzyme that degrades cGMP – may play a role, as the PDE5 inhibitor sildenafil was found to reduce vasospasm after SAH. However, several questions that are critical when considering translational studies remain unanswered. Objective To elucidate the mechanism of action of sildenafil against vasospasm, and to assess whether sildenafil attenuates SAH-induced neuronal cell death, improves functional outcome after SAH, or causes significant physiological side effects when administered at therapeutically relevant doses. Methods SAH was induced via endovascular perforation in male C57BL6 mice. Beginning two hours later, mice received sildenafil citrate (0.7, 2 or 5mg/kg P.O. BID) or vehicle. Neurological outcome was assessed daily. Vasospasm was determined on post-SAH Day 3. Brain PDE5 expression and activity, cGMP content, neuronal cell death, arterial blood pressure (BP), and intracranial pressure (ICP) were examined. Results We found that PDE5 activity (but not expression) is increased after SAH, leading to decreased cGMP levels. Sildenafil attenuates this increase in PDE5 activity and restores cGMP levels after SAH. Post-SAH initiation of sildenafil was found to reduce vasospasm, decrease neuronal cell death, and markedly improve neurological outcome, without causing significant physiological side effects. Conclusion Sildenafil–an FDA-approved drug with a proven track record of safety in humans –is a promising new therapy for vasospasm and neurological deficits following SAH. PMID:21796010

Ibudilast, a phosphodiesterase inhibitor, in combination with low-dose aspirin potently inhibits guinea pig carotid artery thrombosis without extending bleeding time and causing gastric mucosal injury.

PubMed

Matsuzawa, S; Hoshina, K; Sueyoshi, S; Miyata, Y; Manita, S; Ooie, T; Yasue, T; Sasahara, T

2012-12-01

A combination of low-dose aspirin (ASA) and a phosphodiesterase inhibitor has been clinically tried for the secondary prevention of atherothrombotic diseases. The in vivo antithrombotic property of ibudilast (CAS 50847-11-5), a phosphodiesterase 4 (PDE4) inhibitor, was evaluated in a photochemically-induced guinea pig carotid artery thrombosis model in combination with low-dose ASA. The time required to decrease the carotid artery blood flow to the reading "zero" was defined as the time to occlusion (TTO) of the artery through thrombogenesis. Each independent use of ASA (300 mg/kg, p.o.) and ibudilast (3 and 10 mg/kg, p.o.) significantly prolonged the TTO, and ASA (300 mg/kg) significantly increased bleeding time (BT) and gastric mucosal injury. A selective PDE4 inhibitor rolipram (1 and 5 mg/kg, p.o.) tended to prolong the TTO without extending BT. ASA (100 mg/kg) plus ibudilast (3 mg/kg) and ASA (100 mg/kg) plus rolipram (5 mg/kg) markedly prolonged the TTO compared with each agent alone. Interestingly, ASA (100 mg/kg) plus ibudilast (3 mg/kg) caused a longer TTO than ASA (300 mg/kg) alone, without significant extension of BT and gastric mucosal injury as observed in ASA (300 mg/kg). These results indicate that the combination of low-dose ASA and ibudilast has a more potent antithrombotic effect than ASA alone without increasing bleeding tendency and gastric mucosal injury. The potent in vivo antithrombotic effect of this combination may be brought about by an action that is associated with PDE4 inhibition of ibudilast. © Georg Thieme Verlag KG Stuttgart · New York.

Glial molecular alterations with mouse brain development and aging: up-regulation of the Kir4.1 and aquaporin-4.

PubMed

Gupta, Rajaneesh Kumar; Kanungo, Madhusudan

2013-02-01

Glial cells, besides participating as passive supporting matrix, are also proposed to be involved in the optimization of the interstitial space for synaptic transmission by tight control of ionic and water homeostasis. In adult mouse brain, inwardly rectifying K+ (Kir4.1) and aquaporin-4 (AQP4) channels localize to astroglial endfeets in contact with brain microvessels and glutamate synapses, optimizing clearance of extracellular K(+) and water from the synaptic layers. However, it is still unclear whether there is an age-dependent difference in the expressions of Kir4.1 and AQP4 channels specifically during postnatal development and aging when various marked changes occur in brain and if these changes region specific. RT-PCR and immunoblotting was conducted to compare the relative expression of Kir4.1 and AQP4 mRNA and protein in the early and mature postnatal (0-, 15-, 45-day), adult (20-week), and old age (70-week) mice cerebral and cerebellar cortices. Expressions of Kir4.1 and AQP4 mRNA and protein are very low at 0-day. A pronounced and continuous increase was observed by mature postnatal ages (15-, 45-days). However, in the 70-week-old mice, expressions are significantly up-regulated as compared to 20-week-old mice. Both genes follow the same age-related pattern in both cerebral and cerebellar cortices. The time course and expression pattern suggests that Kir4.1 and AQP4 channels may play an important role in brain K(+) and water homeostasis in early postnatal weeks after birth and during aging.

ABERRANT SPLICING OF A BRAIN-ENRICHED ALTERNATIVE EXON ELIMINATES TUMOR SUPPRESSOR FUNCTION AND PROMOTES ONCOGENE FUNCTION DURING BRAIN TUMORIGENESIS

PubMed Central

Bredel, Markus; Ferrarese, Roberto; Harsh, Griffith R.; Yadav, Ajay K.; Bug, Eva; Maticzka, Daniel; Reichardt, Wilfried; Masilamani, Anie P.; Dai, Fangping; Kim, Hyunsoo; Hadler, Michael; Scholtens, Denise M.; Yu, Irene L.Y.; Beck, Jürgen; Srinivasasainagendra, Vinodh; Costa, Fabrizio; Baxan, Nicoleta; Pfeifer, Dietmar; Elverfeldt, Dominik v.; Backofen, Rolf; Weyerbrock, Astrid; Duarte, Christine W.; He, Xiaolin; Prinz, Marco; Chandler, James P.; Vogel, Hannes; Chakravarti, Arnab; Rich, Jeremy N.; Carro, Maria S.

2014-01-01

BACKGROUND: Tissue-specific alternative splicing is known to be critical to emergence of tissue identity during development, yet its role in malignant transformation is undefined. Tissue-specific splicing involves evolutionary-conserved, alternative exons, which represent only a minority of total alternative exons. Many, however, have functional features that influence activity in signaling pathways to profound biological effect. Given that tissue-specific splicing has a determinative role in brain development and the enrichment of genes containing tissue-specific exons for proteins with roles in signaling and development, it is thus plausible that changes in such exons could rewire normal neurogenesis towards malignant transformation. METHODS: We used integrated molecular genetic and cell biology analyses, computational biology, animal modeling, and clinical patient profiles to characterize the effect of aberrant splicing of a brain-enriched alternative exon in the membrane-binding tumor suppressor Annexin A7 (ANXA7) on oncogene regulation and brain tumorigenesis. RESULTS: We show that aberrant splicing of a tissue-specific cassette exon in ANXA7 diminishes endosomal targeting and consequent termination of the signal of the EGFR oncoprotein during brain tumorigenesis. Splicing of this exon is mediated by the ribonucleoprotein Polypyrimidine Tract-Binding Protein 1 (PTBP1), which is normally repressed during brain development but, we find, is excessively expressed in glioblastomas through either gene amplification or loss of a neuron-specific microRNA, miR-124. Silencing of PTBP1 attenuates both malignancy and angiogenesis in a stem cell-derived glioblastoma animal model characterized by a high native propensity to generate tumor endothelium or vascular pericytes to support tumor growth. We show that EGFR amplification and PTBP1 overexpression portend a similarly poor clinical outcome, further highlighting the importance of PTBP1-mediated activation of EGFR

Brain-Derived Neurotrophic Factor (BDNF) and Traumatic Brain Injury (Head and Spinal)

DTIC Science & Technology

2000-01-01

phosphatidylinositol 3-kinase are involved in brain-derived neurotrophic factor- mediated survival and neuritogenesis of the neuroblastoma cell line ... SH - SY5Y , J. Neurochem. 73 (1999) 1409-1421. 15. Gottshalk, W.A., Jiang, H., Tartaglia, N., Feng, L., Figurov, A., Lu, B., Signaling mechanisms...NT-6), and neurotrophin-7 (NT-7) (4, 5, 24, 80). Neurotrophins are believed to promote their cell survival, growth, and differentiation effects

Protective effects of phosphodiesterase 2 inhibitor on depression- and anxiety-like behaviors: involvement of antioxidant and anti-apoptotic mechanisms.

PubMed

Ding, Lianshu; Zhang, Chong; Masood, Anbrin; Li, Jianxin; Sun, Jiao; Nadeem, Ahmed; Zhang, Han-Ting; O' Donnell, James M; Xu, Ying

2014-07-15

Stress occurs in everyday life, but the relationship between stress and the onset or development of depression/anxiety remains unknown. Increasing evidence suggests that the impairment of antioxidant defense and the neuronal cell death are important in the process of emotional disorders. Chronic stress impairs the homeostasis of antioxidants/oxidation, which results in the aberrant stimulation of the cell cycle proteins where cGMP-PKG signaling is thought to have an inhibitory role. Phosphodiesterase 2 (PDE2) is linked to cGMP-PKG signaling and highly expressed in the limbic brain regions including hippocampus and amygdala, which may play important roles in the treatment of depression and anxiety. To address the possible effects of PDE2 inhibitors on depression-/anxiety-like behaviors and the underlying mechanisms, Bay 60-7550 (0.75, 1.5 and 3 mg/kg, i.p.) was administered 30 min before chronic stress. The results suggested that Bay 60-7550 not only restored the behavioral changes but also regulated Cu/Zn superoxide dismutase (SOD) levels differentially in hippocampus and amygdala, which were increased in the hippocampus while decreased in the amygdala. It was also significant that Bay 60-7550 regulated the abnormalities of pro- and anti-apoptotic components, such as Bax, Caspase 3 and Bcl-2, and the indicator of PKG signaling characterized by pVASP(ser239), in these two brain regions. The results suggested that Bay 60-7550 is able to alleviate oxidative stress and mediate part of the apoptotic machinery in neuronal cells possibly through SOD-cGMP/PKG-anti-apoptosis signaling and that inhibition of PDE2 may represent a novel therapeutic target for psychiatric disorders, such as depression and anxiety. Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of Phosphodiesterase in Regulating the Activity of Lysosomes in the HeLa Cell Line.

PubMed

Hong, Eun-Seon; Kim, Bit-Na; Kim, Yang-Hoon; Min, Jiho

2017-02-28

The transport of lysosomal enzymes into the lysosomes depends on the phosphorylation of their chains and the binding of the phosphorylated residues to mannose-6-phosphate receptors. The efficiency of separation depends more on the phosphodiesterases (PDEs) than on the activity of the phosphorylation of mannose residues and can be determined in vitro. PDEs play important roles in regulation of the activation of lysosomes. The expression of proteins was confirmed by western blotting. All PDE4 series protein expression was reduced in high concentrations of rolipram. As a result of observing the fluorescence intensity after rolipram treatment, the lysosomal enzyme was activated at low concentrations and suppressed at high concentrations. High concentrations of rolipram recovered the original function. Antimicrobial activity was not shown in either 10 or 100 µ concentrations of rolipram in treated HeLa cells in vitro. However, the higher anticancer activity at lower rolipram concentration was shown in lysosomal enzyme treated with 10 µ of rolipram. The anticancer activity was confirmed through cathepsin B and D assay. Tranfection allowed examination of the relationship between PDE4 and lysosomal activity in more detail. Protein expression was confirmed to be reduced. Fluorescence intensity showed decreased activity of lysosomes and ROS in cells transfected with the antisense sequences of PDE4 A, B, C, and D. PDE4A showed anticancer activity, whereas lysosome from cells transfected with the antisense sequences of PDE4 B, C, and D had decreased anticancer activity. These results showed the PDE4 A, B, C, and D are conjunctly related with lysosomal activity.

The phosphodiesterase inhibitor, ibudilast, attenuates neuroinflammation in the MPTP model of Parkinson’s disease

PubMed Central

Joniec-Maciejak, Ilona; Cudna, Agnieszka; Mirowska-Guzel, Dagmara; Kurkowska-Jastrzębska, Iwona

2017-01-01

Background/Aims Since the degeneration of the nigrostriatal dopaminergic pathway in Parkinson’s disease (PD) is associated with the inflammation process and decreased levels of cyclic nucleotides, inhibition of up-regulated cyclic nucleotide phosphodiesterases (PDEs) appears to be a promising therapeutic strategy. We used ibudilast (IBD), a non-selective PDE3,4,10,11 inhibitor, due to the abundant PDE 4 and 10 expression in the striatum. The present study for the first time examined the efficacy of IBD in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. Methods IBD [0, 20, 30, 40, or 50 mg/kg] was injected b.i.d. subcutaneously for nine days to three-month-old male C57Bl/10Tar mice, beginning two days prior to MPTP (60 mg/kg) intoxication. High-pressure liquid chromatography, Western blot analysis, and real time RT-PCR methods were applied. Results Our study demonstrated that chronic administration of IBD attenuated astroglial reactivity and increased glial cell-derived neurotrophic factor (GDNF) production in the striatum. Moreover, IBD reduced TNF-α, IL-6, and IL-1β expression. Conclusion IBD had a well-defined effect on astroglial activation in the mouse model of PD; however, there was no protective effect in the acute phase of injury. Diminished inflammation and an increased level of GDNF may provide a better outcome in the later stages of neurodegeneration. PMID:28753652

Effect of phosphodiesterase-5 inhibition on exercise capacity and clinical status in heart failure with preserved ejection fraction: a randomized clinical trial.

PubMed

Redfield, Margaret M; Chen, Horng H; Borlaug, Barry A; Semigran, Marc J; Lee, Kerry L; Lewis, Gregory; LeWinter, Martin M; Rouleau, Jean L; Bull, David A; Mann, Douglas L; Deswal, Anita; Stevenson, Lynne W; Givertz, Michael M; Ofili, Elizabeth O; O'Connor, Christopher M; Felker, G Michael; Goldsmith, Steven R; Bart, Bradley A; McNulty, Steven E; Ibarra, Jenny C; Lin, Grace; Oh, Jae K; Patel, Manesh R; Kim, Raymond J; Tracy, Russell P; Velazquez, Eric J; Anstrom, Kevin J; Hernandez, Adrian F; Mascette, Alice M; Braunwald, Eugene

2013-03-27

Studies in experimental and human heart failure suggest that phosphodiesterase-5 inhibitors may enhance cardiovascular function and thus exercise capacity in heart failure with preserved ejection fraction (HFPEF). To determine the effect of the phosphodiesterase-5 inhibitor sildenafil compared with placebo on exercise capacity and clinical status in HFPEF. Multicenter, double-blind, placebo-controlled, parallel-group, randomized clinical trial of 216 stable outpatients with HF, ejection fraction ≥50%, elevated N-terminal brain-type natriuretic peptide or elevated invasively measured filling pressures, and reduced exercise capacity. Participants were randomized from October 2008 through February 2012 at 26 centers in North America. Follow-up was through August 30, 2012. Sildenafil (n = 113) or placebo (n = 103) administered orally at 20 mg, 3 times daily for 12 weeks, followed by 60 mg, 3 times daily for 12 weeks. Primary end point was change in peak oxygen consumption after 24 weeks of therapy. Secondary end points included change in 6-minute walk distance and a hierarchical composite clinical status score (range, 1-n, a higher value indicates better status; expected value with no treatment effect, 95) based on time to death, time to cardiovascular or cardiorenal hospitalization, and change in quality of life for participants without cardiovascular or cardiorenal hospitalization at 24 weeks. Median age was 69 years, and 48% of patients were women. At baseline, median peak oxygen consumption (11.7 mL/kg/min) and 6-minute walk distance (308 m) were reduced. The median E/e' (16), left atrial volume index (44 mL/m2), and pulmonary artery systolic pressure (41 mm Hg) were consistent with chronically elevated left ventricular filling pressures. At 24 weeks, median (IQR) changes in peak oxygen consumption (mL/kg/min) in patients who received placebo (-0.20 [IQR, -0.70 to 1.00]) or sildenafil (-0.20 [IQR, -1.70 to 1.11]) were not significantly different (P = .90) in

There is less MRI brain lesions and no characteristic MRI Brain findings in IIDDs patients with positive AQP4 serology among Malaysians.

PubMed

Abdullah, Suhailah; Fadzli, Farhana; Ramli, Norlisah; Tan, Chong Tin

2017-02-01

The recently introduced International Consensus diagnostic criteria for diagnosis of neuromyelitis spectrum disorder include patients who are seronegative for AQP4 antibody. The criteria are dependent on typical MRI changes in the spinal cord, optic nerve and brain. This study aims to determine whether there are significant differences in the MRI brain images between AQP4 positive and negative patients with IIDDs. MRI brain of patients with a diagnosis of IIDDs presented to the Hospital from 2010 to 2015 was analysed. The MRI was assessed by 2 radiologists blinded to the AQP4 status, on features said to be typical of NMOSD and MS. Thirty nine patients fulfilled the criteria and were included in the study. They consisted of 19 AQP4 seropositive and 20 AQP4 seronegative patients. The mean age was older (37.0 vs. 28.8 years) among the AQP4 positive group. The majority of the patients were ethnic Chinese (72%), followed by the Malays and Indians. Those with AQP4 seropositive status generally has less brain lesions, and significantly less fulfilling the McDonald DIS criteria as compared to those with AQP4 seronegative status (15.8% vs. 60.0%, p=0.005). None of the seven cerebral MRI features highlighted in NMOSD 2015 diagnostic criteria, said to be characteristic of NMOSD was more common among the AQP4 positive patients. These features were in fact seen less frequently among the AQP4 seropositive patients. An example was the extensive hemispheric lesion seen in 10.5% of AQP4 seropositive patients vs. 45% of that AQP4 seronegative group. There was no characteristic MRI brain features in the Malaysian AQP4 seropositive IIDD patients versus those who are seronegative. This could be a reflection of ethnical difference. Copyright © 2017 Elsevier B.V. All rights reserved.

Migrating Interneurons Secrete Fractalkine to Promote Oligodendrocyte Formation in the Developing Mammalian Brain.

PubMed

Voronova, Anastassia; Yuzwa, Scott A; Wang, Beatrix S; Zahr, Siraj; Syal, Charvi; Wang, Jing; Kaplan, David R; Miller, Freda D

2017-05-03

During development, newborn interneurons migrate throughout the embryonic brain. Here, we provide evidence that these interneurons act in a paracrine fashion to regulate developmental oligodendrocyte formation. Specifically, we show that medial ganglionic eminence (MGE) interneurons secrete factors that promote genesis of oligodendrocytes from glially biased cortical precursors in culture. Moreover, when MGE interneurons are genetically ablated in vivo prior to their migration, this causes a deficit in cortical oligodendrogenesis. Modeling of the interneuron-precursor paracrine interaction using transcriptome data identifies the cytokine fractalkine as responsible for the pro-oligodendrocyte effect in culture. This paracrine interaction is important in vivo, since knockdown of the fractalkine receptor CX3CR1 in embryonic cortical precursors, or constitutive knockout of CX3CR1, causes decreased numbers of oligodendrocyte progenitor cells (OPCs) and oligodendrocytes in the postnatal cortex. Thus, in addition to their role in regulating neuronal excitability, interneurons act in a paracrine fashion to promote the developmental genesis of oligodendrocytes. Copyright © 2017 Elsevier Inc. All rights reserved.

Conformation changes, N-terminal involvement and cGMP signal relay in phosphodiesterase-5 GAF domain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, H.; Robinson, H.; Ke, H.

2010-12-03

The activity of phosphodiesterase-5 (PDE5) is specific for cGMP and is regulated by cGMP binding to GAF-A in its regulatory domain. To better understand the regulatory mechanism, x-ray crystallographic and biochemical studies were performed on constructs of human PDE5A1 containing the N-terminal phosphorylation segment, GAF-A, and GAF-B. Superposition of this unliganded GAF-A with the previously reported NMR structure of cGMP-bound PDE5 revealed dramatic conformational differences and suggested that helix H4 and strand B3 probably serve as two lids to gate the cGMP-binding pocket in GAF-A. The structure also identified an interfacial region among GAF-A, GAF-B, and the N-terminal loop, whichmore » may serve as a relay of the cGMP signal from GAF-A to GAF-B. N-terminal loop 98-147 was physically associated with GAF-B domains of the dimer. Biochemical analyses showed an inhibitory effect of this loop on cGMP binding and its involvement in the cGMP-induced conformation changes.« less

Pharmacological validation of Trypanosoma brucei phosphodiesterases B1 and B2 as druggable targets for African sleeping sickness.

PubMed

Bland, Nicholas D; Wang, Cuihua; Tallman, Craig; Gustafson, Alden E; Wang, Zhouxi; Ashton, Trent D; Ochiana, Stefan O; McAllister, Gregory; Cotter, Kristina; Fang, Anna P; Gechijian, Lara; Garceau, Norman; Gangurde, Rajiv; Ortenberg, Ron; Ondrechen, Mary Jo; Campbell, Robert K; Pollastri, Michael P

2011-12-08

Neglected tropical disease drug discovery requires application of pragmatic and efficient methods for development of new therapeutic agents. In this report, we describe our target repurposing efforts for the essential phosphodiesterase (PDE) enzymes TbrPDEB1 and TbrPDEB2 of Trypanosoma brucei , the causative agent for human African trypanosomiasis (HAT). We describe protein expression and purification, assay development, and benchmark screening of a collection of 20 established human PDE inhibitors. We disclose that the human PDE4 inhibitor piclamilast, and some of its analogues, show modest inhibition of TbrPDEB1 and B2 and quickly kill the bloodstream form of the subspecies T. brucei brucei . We also report the development of a homology model of TbrPDEB1 that is useful for understanding the compound-enzyme interactions and for comparing the parasitic and human enzymes. Our profiling and early medicinal chemistry results strongly suggest that human PDE4 chemotypes represent a better starting point for optimization of TbrPDEB inhibitors than those that target any other human PDEs.

HDAC4: a key factor underlying brain developmental alterations in CDKL5 disorder.

PubMed

Trazzi, Stefania; Fuchs, Claudia; Viggiano, Rocchina; De Franceschi, Marianna; Valli, Emanuele; Jedynak, Paulina; Hansen, Finn K; Perini, Giovanni; Rimondini, Roberto; Kurz, Thomas; Bartesaghi, Renata; Ciani, Elisabetta

2016-09-15

Cyclin-dependent kinase-like 5 (CDKL5) is a Ser/Thr protein kinase predominantly expressed in the brain. Mutations of the CDKL5 gene lead to CDKL5 disorder, a neurodevelopmental pathology that shares several features with Rett Syndrome and is characterized by severe intellectual disability. The phosphorylation targets of CDKL5 are largely unknown, which hampers the discovery of therapeutic strategies for improving the neurological phenotype due to CDKL5 mutations. Here, we show that the histone deacetylase 4 (HDAC4) is a direct phosphorylation target of CDKL5 and that CDKL5-dependent phosphorylation promotes HDAC4 cytoplasmic retention. Nuclear HDAC4 binds to chromatin as well as to MEF2A transcription factor, leading to histone deacetylation and altered neuronal gene expression. By using a Cdkl5 knockout (Cdkl5 -/Y) mouse model, we found that hypophosphorylated HDAC4 translocates to the nucleus of neural precursor cells, thereby reducing histone 3 acetylation. This effect was reverted by re-expression of CDKL5 or by inhibition of HDAC4 activity through the HDAC4 inhibitor LMK235. In Cdkl5 -/Y mice treated with LMK235, defective survival and maturation of neuronal precursor cells and hippocampus-dependent memory were fully normalized. These results demonstrate a critical role of HDAC4 in the neurodevelopmental alterations due to CDKL5 mutations and suggest the possibility of HDAC4-targeted pharmacological interventions. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

RB4CD12 epitope expression and heparan sulfate disaccharide composition in brain vasculature.

PubMed

Hosono-Fukao, Tomomi; Ohtake-Niimi, Shiori; Nishitsuji, Kazuchika; Hossain, Md Motarab; van Kuppevelt, Toin H; Michikawa, Makoto; Uchimura, Kenji

2011-11-01

RB4CD12 is a phage display antibody that recognizes a heparan sulfate (HS) glycosaminoglycan epitope. The epitope structure is proposed to contain a trisulfated disaccharide, [-IdoA(2-OSO(3))-GlcNSO(3) (6-OSO(3))-], which supports HS binding to various macromolecules such as growth factors and cytokines in central nervous tissues. Chemically modified heparins that lack the trisulfated disaccharides failed to inhibit the RB4CD12 recognition of HS chains. To determine the localization of the RB4CD12 anti-HS epitope in the brain, we performed an immunohistochemical analysis for cryocut sections of mouse brain. The RB4CD12 staining signals were colocalized with laminin and were detected abundantly in the vascular basement membrane. Bacterial heparinases eliminated the RB4CD12 staining signals. The RB4CD12 epitope localization was confirmed by immunoelectron microscopy. Western blotting analysis revealed that the size of a major RB4CD12-positive molecule is ∼460 kDa in a vessel-enriched fraction of the mouse brain. Disaccharide analysis with reversed-phase ion-pair HPLC showed that [-IdoA(2-OSO(3))-GlcNSO(3) (6-OSO(3))-] trisulfated disaccharide residues are present in HS purified from the vessel-enriched brain fraction. These results indicated that the RB4CD12 anti-HS epitope exists in large quantities in the brain vascular basement membrane. Copyright © 2011 Wiley-Liss, Inc.

Digit ratio (2D:4D) in primary brain tumor patients: A case-control study.

PubMed

Bunevicius, Adomas; Tamasauskas, Sarunas; Deltuva, Vytenis Pranas; Tamasauskas, Arimantas; Sliauzys, Albertas; Bunevicius, Robertas

2016-12-01

The second-to-fourth digit ratio (2D:4D) reflects prenatal estrogen and testosterone exposure, and is established in utero. Sex steroids are implicated in development and progression of primary brain tumors. To investigate whether there is a link between 2D:4D ratio and primary brain tumors, and age at presentation. Digital images of the right and left palms of 85 primary brain tumor patients (age 56.96±13.68years; 71% women) and 106 (age 54.31±13.68years; 68% women) gender and age matched controls were obtained. The most common brain tumor diagnoses were meningioma (41%), glioblastoma (20%) and pituitary adenoma (16%). Right and left 2D:4D ratios, and right minus left 2D:4D (D r-l ) were compared between patients and controls, and were correlated with age. Right and left 2D:4D ratios were significantly lower in primary brain tumor patients relative to controls (t=-4.28, p<0.001 and t=-3.69, p<0.001, respectively). The D r-l was not different between brain tumor patients and controls (p=0.27). In meningioma and glioma patients, age at presentation correlated negatively with left 2D:4D ratio (rho=-0.42, p=0.01 and rho=-0.36, p=0.02, respectively) and positively with D r-l (rho=0.45, p=0.009 and rho=0.65, p=0.04, respectively). Right and left hand 2D:4D ratios are lower in primary brain tumor patients relative to healthy individuals suggesting greater prenatal testosterone and lower prenatal estrogen exposure in brain tumor patients. Greater age at presentation is associated with greater D r-l and with lower left 2D:4D ratio of meningioma and glioma patients. Due to small sample size our results should be considered preliminary and interpreted with caution. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The role of phosphodiesterase activity on the temperature-dependent responses of calf cardiac vein.

PubMed

Nurullahoglu, Z U

2013-01-01

To evaluate the role of phosphodiesterase (PDE) activity in the cooling (to 28 °C) and warming (41 °C)-induced effects of carbachol on calf cardiac vein. Rings obtained from calf hearts were suspended in organ baths containing 25 ml of Krebs-Henseleit solution, maintained at 37 °C, continuously gassed with 95%O2-5%CO2. At the end of the resting period the preparations were contracted with carbachol (10-9-3x10-4M), at 37 °C. The same protocol was repeated at 28 °C and 41 °C after the preparations were allowed to equilibrate at this temperature for 60 min. In order to analyze the role of PDE activity in the cooling-and warming-induced vascular response, carbachol (10-9-3x10-4M) was applied in the presence of cilostazol (10-6 M), IBMX (10-6 M) and rolipram (10-6 M), respectively. The sensitivity of carbachol was significantly lower during cooling, and higher during warming. Cooling to 28 and warming to 41 °C, after treatment with IBMX, cilostazol or rolipram, significantly decreased the sensitivity to carbachol (p<0.05). The results of the present study suggest that PDE activity plays an essential role in cooling-and warming-induced changes of calf cardiac vein treated with carbachol (Tab. 1, Fig. 2, Ref. 34). Text in PDF www.elis.sk.

Let-7i attenuates human brain microvascular endothelial cell damage in oxygen glucose deprivation model by decreasing toll-like receptor 4 expression.

PubMed

Xiang, Wei; Tian, Canhui; Peng, Shunli; Zhou, Liang; Pan, Suyue; Deng, Zhen

2017-11-04

The let-7 family of microRNAs (miRNAs) plays an important role on endothelial cell function. However, there have been few studies on their role under ischemic conditions. In this study, we demonstrate that let-7i, belonging to the let-7 family, rescues human brain microvascular endothelial cells (HBMECs) in an oxygen-glucose deprivation (OGD) model. Our data show that the expression of let-7 family miRNAs was downregulated after OGD. Overexpression of let-7i significantly alleviated cell death and improved survival of OGD-treated HBMECs. Let-7i also protected permeability in an in vitro blood brain barrier (BBB) model. Further, let-7i downregulated the expression of toll-like receptor 4 (TLR4), an inflammation trigger. Moreover, overexpression of let-7i decreased matrix metallopeptidase 9 (MMP9) and inducible nitric oxide synthase (iNOS) expression under OGD. Upon silencing TLR4 expression in HBMECs, the anti-inflammatory effect of let-7i was abolished. Our research suggests that let-7i promotes OGD-induced inflammation via downregulating TLR4 expression. Copyright © 2017 Elsevier Inc. All rights reserved.

Fifth dimension of life and the 4/5 allometric scaling law for human brain.

PubMed

He, Ji-Huan; Zhang, Juan

2004-01-01

Brain cells are not spherical. The basal metabolic rate (B) of a spherical cell scales as B approximately r2, where r is the radius of the cell; that of a brain cell scales as B approximately r(d), where r is the characteristic radius of the cell and d is the fractal dimensionality of its contour. The fractal geometry of the cell leads to a 4/5 allometric scaling law for human brain, uniquely endowing humans with a 5th dimension and successfully explains why the scaling exponent varies during rest and exercise. A striking analogy between Kleiber's 3/4 law and Newton's second law is heuristically illustrated. A physical explanation is given for the 4th dimension of life for three-dimensional organisms and the 5th dimension for human brain.

Endothelial ErbB4 deficit induces alterations in exploratory behavior and brain energy metabolism in mice.

PubMed

Wu, Gang; Liu, Xiu-Xiu; Lu, Nan-Nan; Liu, Qi-Bing; Tian, Yun; Ye, Wei-Feng; Jiang, Guo-Jun; Tao, Rong-Rong; Han, Feng; Lu, Ying-Mei

2017-06-01

The receptor tyrosine kinase ErbB4 is present throughout the primate brain and has a distinct functional profile. In this study, we investigate the potential role of endothelial ErbB4 receptor signaling in the brain. Here, we show that the endothelial cell-specific deletion of ErbB4 induces decreased exploratory behavior in adult mice. However, the water maze task for spatial memory and the memory reconsolidation test reveal no changes; additionally, we observe no impairment in CaMKII phosphorylation in Cdh5Cre;ErbB4 f/f mice, which indicates that the endothelial ErbB4 deficit leads to decreased exploratory activity rather than direct memory deficits. Furthermore, decreased brain metabolism, which was measured using micro-positron emission tomography, is observed in the Cdh5Cre;ErbB4 f/f mice. Consistently, the immunoblot data demonstrate the downregulation of brain Glut1, phospho-ULK1 (Ser555), and TIGAR in the endothelial ErbB4 conditional knockout mice. Collectively, our findings suggest that endothelial ErbB4 plays a critical role in regulating brain function, at least in part, through maintaining normal brain energy homeostasis. Targeting ErbB4 or the modulation of endothelial ErbB4 signaling may represent a rational pharmacological approach to treat neurological disorders. © 2017 John Wiley & Sons Ltd.

Regulation of ecto-apyrase CD39 (ENTPD1) expression by phosphodiesterase III (PDE3)

PubMed Central

Baek, Amy E.; Kanthi, Yogendra; Sutton, Nadia R.; Liao, Hui; Pinsky, David J.

2013-01-01

The ectoenzyme CD39 suppresses thrombosis and inflammation by suppressing ATP and ADP to AMP. However, mechanisms of CD39 transcriptional and post-translational regulation are not well known. Here we show that CD39 levels are modulated by inhibition of phosphodiesterase 3 (PDE3). RAW macrophages and human umbilical vein endothelial cells (HUVECs) were treated with the PDE3 inhibitors cilostazol and milrinone, then analyzed using qRT-PCR, immunoprecipitation/Western blot, immunofluorescent staining, radio-thin-layer chromatography, a malachite green assay, and ELISA. HUVECs expressed elevated CD39 protein (2-fold [P<0.05] for cilostazol and 2.5-fold [P<0.01] for milrinone), while macrophage CD39 mRNA and protein were both elevated after PDE3 inhibition. HUVEC ATPase activity increased by 25% with cilostazol and milrinone treatment (P<0.05 and P<0.01, respectively), as did ADPase activity (47% and 61%, P<0.001). There was also a dose-dependent elevation of soluble CD39 after treatment with 8-Br-cAMP, with maximal elevation of 60% more CD39 present compared to controls (1 mM, P<0.001). Protein harvested after 8-Br-cAMP treatment showed that ubiquitination of CD39 was decreased by 43% compared to controls. A DMSO or PBS vehicle control was included for each experiment based on solubility of cilostazol, milrinone, and 8-Br-cAMP. These results indicate that PDE3 inhibition regulates endothelial CD39 at a post-translational level.—Baek, A. E., Kanthi, Y., Sutton, N. R., Liao, H., Pinsky, D. J. Regulation of ecto-apyrase CD39 (ENTPD1) expression by phosphodiesterase III (PDE3). PMID:23901069

Developmental exposure to trichloroethylene promotes CD4{sup +} T cell differentiation and hyperactivity in association with oxidative stress and neurobehavioral deficits in MRL+/+ mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blossom, Sarah J.; Doss, Jason C.; Hennings, Leah J.

2008-09-15

The non adult immune system is particularly sensitive to perinatal and early life exposures to environmental toxicants. The common environmental toxicant, trichloroethylene (TCE), was shown to increase CD4+ T cell production of the proinflammatory cytokine IFN-{gamma} following a period of prenatal and lifetime exposure in autoimmune-prone MRL+/+ mice. In the current study, MRL+/+ mice were used to further examine the impact of TCE on the immune system in the thymus and periphery. Since there is considerable cross-talk between the immune system and the brain during development, the potential relationship between TCE and neurobehavioral endpoints were also examined. MRL+/+ mice weremore » exposed to 0.1 mg/ml TCE ({approx} 31 mg/kg/day) via maternal drinking water or direct exposure via the drinking water from gestation day 1 until postnatal day (PD) 42. TCE exposure did not impact gross motor skills but instead significantly altered social behaviors and promoted aggression associated with indicators of oxidative stress in brain tissues in male mice. The immunoregulatory effects of TCE involved a redox-associated promotion of T cell differentiation in the thymus that preceded the production of proinflammatory cytokines, IL-2, TNF-{alpha}, and IFN-{gamma} by mature CD4+ T cells. The results demonstrated that developmental and early life TCE exposure modulated immune function and may have important implications for neurodevelopmental disorders.« less

Promoting Early Brain and Child Development: Perceived Barriers and the Utilization of Resources to Address Them.

PubMed

Garner, Andrew S; Storfer-Isser, Amy; Szilagyi, Moira; Stein, Ruth E K; Green, Cori M; Kerker, Bonnie D; O'Connor, Karen G; Hoagwood, Kimberly E; McCue Horwitz, Sarah

Efforts to promote early brain and child development (EBCD) include initiatives to support healthy parent-child relationships, tools to identify family social-emotional risk factors, and referrals to community programs to address family risk factors. We sought to examine if pediatricians perceive barriers to implementing these activities, and if they utilize resources to address those barriers. Data were analyzed from 304 nontrainee pediatricians who practice general pediatrics and completed a 2013 American Academy of Pediatrics Periodic Survey. Sample weights were used to decrease nonresponse bias. Bivariate comparisons and multivariable regression analyses were conducted. At least half of the pediatricians agreed that barriers to promoting EBCD include: a lack of tools to promote healthy parent-child relationships, a lack of tools to assess the family environment for social-emotional risk factors, and a lack of local resources to address family risks. Endorsing a lack of tools to assess the family environment as a barrier was associated with using fewer screening tools and community resources. Endorsing a lack of local resources as a barrier was associated with using fewer community resources and fewer initiatives to promote parent-child relationships. Interest in pediatric mental health was associated with using more initiatives to promote healthy parent-child relationships, screening tools, and community resources. Although the majority of pediatricians perceive barriers to promoting EBCD, few are routinely using available resources to address these barriers. Addressing pediatricians' perceived barriers and encouraging interest in pediatric mental health may increase resource utilization and enhance efforts to promote EBCD. Copyright © 2016 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Genetic variation in Aquaporin-4 moderates the relationship between sleep and brain Aβ-amyloid burden.

PubMed

Rainey-Smith, Stephanie R; Mazzucchelli, Gavin N; Villemagne, Victor L; Brown, Belinda M; Porter, Tenielle; Weinborn, Michael; Bucks, Romola S; Milicic, Lidija; Sohrabi, Hamid R; Taddei, Kevin; Ames, David; Maruff, Paul; Masters, Colin L; Rowe, Christopher C; Salvado, Olivier; Martins, Ralph N; Laws, Simon M

2018-02-26

The glymphatic system is postulated to be a mechanism of brain Aβ-amyloid clearance and to be most effective during sleep. Ablation of the astrocytic end-feet expressed water-channel protein, Aquaporin-4, in mice, results in impairment of this clearance mechanism and increased brain Aβ-amyloid deposition, suggesting that Aquaporin-4 plays a pivotal role in glymphatic function. Currently there is a paucity of literature regarding the impact of AQP4 genetic variation on sleep, brain Aβ-amyloid burden and their relationship to each other in humans. To address this a cross-sectional observational study was undertaken in cognitively normal older adults from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study. Genetic variants in AQP4 were investigated with respect to self-reported Pittsburgh Sleep Quality Index sleep parameters, positron emission tomography derived brain Aβ-amyloid burden and whether these genetic variants moderated the sleep-Aβ-amyloid burden relationship. One AQP4 variant, rs72878776, was associated with poorer overall sleep quality, while several SNPs moderated the effect of sleep latency (rs491148, rs9951307, rs7135406, rs3875089, rs151246) and duration (rs72878776, rs491148 and rs2339214) on brain Aβ-amyloid burden. This study suggests that AQP4 genetic variation moderates the relationship between sleep and brain Aβ-amyloid burden, which adds weight to the proposed glymphatic system being a potential Aβ-amyloid clearance mechanism and suggests that AQP4 genetic variation may impair this function. Further, AQP4 genetic variation should be considered when interpreting sleep-Aβ relationships.

Functional expression of calcium-permeable canonical transient receptor potential 4-containing channels promotes migration of medulloblastoma cells.

PubMed

Wei, Wei-Chun; Huang, Wan-Chen; Lin, Yu-Ping; Becker, Esther B E; Ansorge, Olaf; Flockerzi, Veit; Conti, Daniele; Cenacchi, Giovanna; Glitsch, Maike D

2017-08-15

The proton sensing ovarian cancer G protein coupled receptor 1 (OGR1, aka GPR68) promotes expression of the canonical transient receptor potential channel subunit TRPC4 in normal and transformed cerebellar granule precursor (DAOY) cells. OGR1 and TRPC4 are prominently expressed in healthy cerebellar tissue throughout postnatal development and in primary cerebellar medulloblastoma tissues. Activation of TRPC4-containing channels in DAOY cells, but not non-transformed granule precursor cells, results in prominent increases in [Ca 2+ ] i and promotes cell motility in wound healing and transwell migration assays. Medulloblastoma cells not arising from granule precursor cells show neither prominent rises in [Ca 2+ ] i nor enhanced motility in response to TRPC4 activation unless they overexpressTRPC4. Our results suggest that OGR1 enhances expression of TRPC4-containing channels that contribute to enhanced invasion and metastasis of granule precursor-derived human medulloblastoma. Aberrant intracellular Ca 2+ signalling contributes to the formation and progression of a range of distinct pathologies including cancers. Rises in intracellular Ca 2+ concentration occur in response to Ca 2+ influx through plasma membrane channels and Ca 2+ release from intracellular Ca 2+ stores, which can be mobilized in response to activation of cell surface receptors. Ovarian cancer G protein coupled receptor 1 (OGR1, aka GPR68) is a proton-sensing G q -coupled receptor that is most highly expressed in cerebellum. Medulloblastoma (MB) is the most common paediatric brain tumour that arises from cerebellar precursor cells. We found that nine distinct human MB samples all expressed OGR1. In both normal granule cells and the transformed human cerebellar granule cell line DAOY, OGR1 promoted expression of the proton-potentiated member of the canonical transient receptor potential (TRPC) channel family, TRPC4. Consistent with a role for TRPC4 in MB, we found that all MB samples also expressed

Photooxidation of d(TpG) by phthalocyanines and riboflavin. Isolation and characterization of dinucleoside monophosphates containing the 4R* and 4S* diastereoisomers of 4,8-dihydro-4-hydroxy-8-oxo-2'-deoxy-guanosine.

PubMed Central

Buchko, G W; Cadet, J; Berger, M; Ravanat, J L

1992-01-01

Phthalocyanine mediated photosensitization of 2'-deoxyguanosine (dG) in oxygen saturated aqueous solution has previously been shown to result in the addition of molecular oxygen to the guanine base generating the 4R* and 4S* diastereoisomers of 4,8-dihydro-4-hydroxy-8-oxo-2'-deoxyguanosine (dO) (the asterisk denotes unambiguous assignment of the 4R and 4S diastereoisomers). The data presented here show that the same guanine modified bases are generated in a 1:1 ratio when thymidylyl-(3',5')-2'-deoxyguanosine (d(TpG)) is similarly photo-oxidized. These modified dinucleoside monophosphates, labelled d(TpO)-A and -B, have been isolated by high performance liquid chromatography and characterized by proton NMR spectrometry, fast atom bombardment mass spectrometry, and enzymatic digestions. Photosensitization in D2O instead of H2O leads to an increase in the rate of d(TpO) formation that is consistent with a type II (singlet oxygen) reaction mechanism. Three interesting properties of these modified dinucleoside monophosphates are: i) the rate of their digestion with spleen phosphodiesterase is greatly reduced relative to d(TpG), ii) they are not digested by snake venom phosphodiesterase, and iii) they are stable to 1.0 M piperidine at 90 degrees C for 30 min. The latter observation indicates that 4,8-dihydro-4-hydroxy-8-oxoguanine is not a base lesion responsible for the strand breaks observed following hot piperidine treatment of DNA exposed to type II photosensitizers or chemically generated singlet oxygen. PMID:1329029

Previous exposure to (+/-) 3,4-methylenedioxymethamphetamine produces long-lasting alteration in limbic brain excitability measured by electroencephalogram spectrum analysis, brain metabolism and seizure susceptibility.

PubMed

Giorgi, F S; Pizzanelli, C; Ferrucci, M; Lazzeri, G; Faetti, M; Giusiani, M; Pontarelli, F; Busceti, C L; Murri, L; Fornai, F

2005-01-01

Seizures represent the most common neurological emergency in ecstasy abusers; however, no study addressed whether (+/-) 3,4-methylenedioxymethamphetamine ("ecstasy") per se might produce long-lasting alterations in brain excitability related to a pro-convulsant effect. C57 Black mice were treated with three regimens of (+/-) 3,4-methylenedioxymethamphetamine (5mg/kg x 2 for 1, 2 or three consecutive days). Following the last dose of (+/-) 3,4-methylenedioxymethamphetamine, during a time interval of 8 weeks, the following procedures were carried out: 1) cortical electroencephalographic recordings, including power-spectrum analysis; 2) administration of sub-threshold doses of kainate; 3) measurement of regional [(14)C]2-deoxyglucose uptake; 4) monoamine assay. We demonstrate that all mice pre-treated with (+/-) 3,4-methylenedioxymethamphetamine showed long-lasting encephalographic changes with frequencies peaking at 3-4.5 Hz at the power-spectrum analysis. This is concomitant with latent brain hyperexcitability within selected limbic brain regions, as shown by seizure facilitation and long-lasting latent metabolic hyperactivity which can be unraveled by phasic glutamate stimulation. This study sheds new light into the brain targets of (+/-) 3,4-methylenedioxymethamphetamine and discloses the occurrence of (+/-) 3,4-methylenedioxymethamphetamine-induced latent hyperexcitability within limbic areas, while it might provide a model to study in controlled experimental conditions limbic seizures and status epilepticus in C57 Black mice. Persistent changes produced by (+/-) 3,4-methylenedioxymethamphetamine in limbic brain excitability might be responsible for seizures and limbic-related disorders in chronic (+/-) 3,4-methylenedioxymethamphetamine abusers.

[2,4-13C2]-β-Hydroxybutyrate Metabolism in Human Brain

PubMed Central

Pan, Jullie W.; de Graaf, Robin A.; Petersen, Kitt F.; Shulman, Gerald I.; Hetherington, Hoby P.; Rothman, Douglas L.

2010-01-01

Summary Infusions of [2,4-13C2]-β-hydroxybutyrate and 1H–13C polarization transfer spectroscopy were used in normal human subjects to detect the entry and metabolism of β-hydroxybutyrate in the brain. During the 2-hour infusion study, 13C label was detectable in the β-hydroxybutyrate resonance positions and in the amino acid pools of glutamate, glutamine, and aspartate. With a plasma concentration of 2.25 ± 0.24 mmol/L (four volunteers), the apparent tissue β-hydroxybutyrate concentration reached 0.18 ± 0.06 mmol/L during the last 20 minutes of the study. The relative fractional enrichment of 13C-4-glutamate labeling was 6.78 ± 1.71%, whereas 13C-4-glutamine was 5.68 ± 1.84%. Steady-state modeling of the 13C label distribution in glutamate and glutamine suggests that, under these conditions, the consumption of the β-hydroxybutyrate is predominantly neuronal, used at a rate of 0.032 ± 0.009 mmol · kg−1 · min−1, and accounts for 6.4 ± 1.6% of total acetyl coenzyme A oxidation. These results are consistent with minimal accumulation of cerebral ketones with rapid utilization, implying blood–brain barrier control of ketone oxidation in the nonfasted adult human brain. PMID:12142574

Exogenous fatty acid binding protein 4 promotes human prostate cancer cell progression.

PubMed

Uehara, Hisanori; Takahashi, Tetsuyuki; Oha, Mina; Ogawa, Hirohisa; Izumi, Keisuke

2014-12-01

Epidemiologic studies have found that obesity is associated with malignant grade and mortality in prostate cancer. Several adipokines have been implicated as putative mediating factors between obesity and prostate cancer. Fatty acid binding protein 4 (FABP4), a member of the cytoplasmic fatty acid binding protein multigene family, was recently identified as a novel adipokine. Although FABP4 is released from adipocytes and mean circulating concentrations of FABP4 are linked with obesity, effects of exogenous FABP4 on prostate cancer progression are unclear. In this study, we examined the effects of exogenous FABP4 on human prostate cancer cell progression. FABP4 treatment promoted serum-induced prostate cancer cell invasion in vitro. Furthermore, oleic acid promoted prostate cancer cell invasion only if FABP4 was present in the medium. These promoting effects were reduced by FABP4 inhibitor, which inhibits FABP4 binding to fatty acids. Immunostaining for FABP4 showed that exogenous FABP4 was taken up into DU145 cells in three-dimensional culture. In mice, treatment with FABP4 inhibitor reduced the subcutaneous growth and lung metastasis of prostate cancer cells. Immunohistochemical analysis showed that the number of apoptotic cells, positive for cleaved caspase-3 and cleaved PARP, was increased in subcutaneous tumors of FABP4 inhibitor-treated mice, as compared with control mice. These results suggest that exogenous FABP4 might promote human prostate cancer cell progression by binding with fatty acids. Additionally, exogenous FABP4 activated the PI3K/Akt pathway, independently of binding to fatty acids. Thus, FABP4 might be a key molecule to understand the mechanisms underlying the obesity-prostate cancer progression link. © 2014 UICC.

Expression of the water channel protein, aquaporin-4, in mouse brains exposed to mobile telephone radiofrequency fields.

PubMed

Finnie, John W; Blumbergs, Peter C; Cai, Zhao; Manavis, Jim

2009-01-01

To determine whether exposure to mobile telephone radiofrequency (RF) fields, either acutely or long-term, produces up-regulation of the water channel protein, aquaporin-4 (AQP-4). Using a purpose-designed exposure system at 900 MHz, mice were given a single, far-field whole body exposure at a specific absorption rate of 4 W/kg for 60 minutes or a similar exposure on 5 successive days/week for 104 weeks. Control mice were sham-exposed or freely mobile in a cage to control for any stress caused by restraint in the exposure module. A positive control group was given a clostridial toxin known to cause microvascular endothelial injury, severe vasogenic oedema and upregulation of AQP-4. Brains were perfusion fixed with 4% paraformaldehyde, coronal sections cut from six levels, and immunostained for the principal water channel protein in brain, AQP-4. There was no increase in AQP-4 expression in brains exposed to mobile phone microwaves compared to control (sham exposed and freely moving caged mice) brains after short or protracted exposure, while AQP-4 was substantially upregulated in the brains of mice given the clostridial toxin. Brains exposed to mobile telephone RF fields for a short (60 minutes) or long (2 years) duration did not show any immunohistochemically detectable up-regulation of the water channel protein, AQP-4, suggesting that there was no significant increase in blood-brain barrier permeability

Sildenafil and Phosphodiesterase-5 Inhibitors to Reduce Cardiotoxicity and Enhance the Response of Breast Tumor Cells to Doxorubicin

DTIC Science & Technology

2010-07-01

were blocked for 30 min in PBS with gelatin . The chamber slide basket was then removed before incubation with primary antibody. 53BP1 primary antibody...then incubated with fluorescein-conjugated secondary antibody in PBS with gelatin for 1 h. Following this 1 h of incubation, slides were washed 3 9 5...properties of cancer drugs. J Pharmacol Toxicol Methods 54(3):313–319 28. Essayan DM (2001) Cyclic nucleotide phosphodiesterases. J Allergy Clin

Clinical and Molecular Genetics of the Phosphodiesterases (PDEs)

PubMed Central

Azevedo, Monalisa F.; Faucz, Fabio R.; Bimpaki, Eirini; Horvath, Anelia; Levy, Isaac; de Alexandre, Rodrigo B.; Ahmad, Faiyaz; Manganiello, Vincent

2014-01-01

Cyclic nucleotide phosphodiesterases (PDEs) are enzymes that have the unique function of terminating cyclic nucleotide signaling by catalyzing the hydrolysis of cAMP and GMP. They are critical regulators of the intracellular concentrations of cAMP and cGMP as well as of their signaling pathways and downstream biological effects. PDEs have been exploited pharmacologically for more than half a century, and some of the most successful drugs worldwide today affect PDE function. Recently, mutations in PDE genes have been identified as causative of certain human genetic diseases; even more recently, functional variants of PDE genes have been suggested to play a potential role in predisposition to tumors and/or cancer, especially in cAMP-sensitive tissues. Mouse models have been developed that point to wide developmental effects of PDEs from heart function to reproduction, to tumors, and beyond. This review brings together knowledge from a variety of disciplines (biochemistry and pharmacology, oncology, endocrinology, and reproductive sciences) with emphasis on recent research on PDEs, how PDEs affect cAMP and cGMP signaling in health and disease, and what pharmacological exploitations of PDEs may be useful in modulating cyclic nucleotide signaling in a way that prevents or treats certain human diseases. PMID:24311737

Intracellular Membrane Association of the Aplysia cAMP Phosphodiesterase Long and Short Forms via Different Targeting Mechanisms*

PubMed Central

Kim, Kun-Hyung; Jun, Yong-Woo; Park, Yongsoo; Lee, Jin-A; Suh, Byung-Chang; Lim, Chae-Seok; Lee, Yong-Seok; Kaang, Bong-Kiun; Jang, Deok-Jin

2014-01-01

Phosphodiesterases (PDEs) play key roles in cAMP compartmentalization, which is required for intracellular signaling processes, through specific subcellular targeting. Previously, we showed that the long and short forms of Aplysia PDE4 (ApPDE4), which are localized to the membranes of distinct subcellular organelles, play key roles in 5-hydroxytryptamine-induced synaptic facilitation in Aplysia sensory and motor synapses. However, the molecular mechanism of the isoform-specific distinct membrane targeting was not clear. In this study, we further investigated the molecular mechanism of the membrane targeting of the ApPDE4 long and short forms. We found that the membrane targeting of the long form was mediated by hydrophobic interactions, mainly via 16 amino acids at the N-terminal region, whereas the short form was targeted solely to the plasma membrane, mainly by nonspecific electrostatic interactions between their N termini and the negatively charged lipids such as the phosphatidylinositol polyphosphates PI4P and PI(4,5)P2, which are embedded in the inner leaflet of the plasma membrane. Moreover, oligomerization of the long or short form by interaction of their respective upstream conserved region domains, UCR1 and UCR2, enhanced their plasma membrane targeting. These results suggest that the long and short forms of ApPDE4 are distinctly targeted to intracellular membranes through their direct association with the membranes via hydrophobic and electrostatic interactions, respectively. PMID:25077971

Limited brain distribution of [3R,4R,5S]-4-acetamido-5-amino-3-(1-ethylpropoxy)-1-cyclohexene-1-carboxylate phosphate (Ro 64-0802), a pharmacologically active form of oseltamivir, by active efflux across the blood-brain barrier mediated by organic anion transporter 3 (Oat3/Slc22a8) and multidrug resistance-associated protein 4 (Mrp4/Abcc4).

PubMed

Ose, Atsushi; Ito, Mototsugu; Kusuhara, Hiroyuki; Yamatsugu, Kenzo; Kanai, Motomu; Shibasaki, Masakatsu; Hosokawa, Masakiyo; Schuetz, John D; Sugiyama, Yuichi

2009-02-01

[3R,4R,5S]-4-Acetamido-5-amino-3-(1-ethylpropoxy)-1-cyclohexene-1-carboxylate phosphate (Ro 64-0802) is a pharmacologically active form of the anti-influenza virus drug oseltamivir. Abnormal behavior is a suspected adverse effect of oseltamivir on the central nervous system. This study focused on the transport mechanisms of Ro 64-0802 across the blood-brain barrier (BBB). Ro 64-0802 was found to be a substrate of organic anion transporter 3 (OAT3/SLC22A8) and multidrug resistance-associated protein 4 (MRP4/ABCC4). Human embryonic kidney 293 cells expressing OAT3 exhibited a greater intracellular accumulation of Ro 64-0802 than mock-transfected cells (15 versus 1.2 microl/mg protein/10 min, respectively). The efflux of Ro 64-0802 was 3-fold greater when MRP4 was expressed in MDCKII cells and was significantly inhibited by indomethacin. After its microinjection into the cerebrum, the amount of Ro 64-0802 in brain was significantly greater in both Oat3(-/-) mice and Mrp4(-/-) mice compared with the corresponding wild-type mice (0.36 versus 0.080 and 0.32 versus 0.060 nmol at 120 min after injection, respectively). The brain/plasma concentration ratio (K(p,) (brain)) of Ro 64-0802, determined in wild-type mice after subcutaneous continuous infusion for 24 h, was close to the capillary volume (approximately 10 microl/g brain). Although the K(p,) (brain) of Ro 64-0802 was unchanged in Oat3(-/-) mice, it was significantly greater in Mrp4(-/-) mice (41 microl/g of brain). These results suggest that Ro 64-0802 can cross the BBB from the blood, but its brain distribution is limited by its active efflux by Mrp4 and Oat3 across the BBB. The transporter responsible for the brain uptake of Ro 64-0802 remains unknown, but Oat3 is a candidate transporter.

Plant-growth promoting Candida sp. AVGB4 with capability of 4-nitroaniline biodegradation under drought stress.

PubMed

Silambarasan, Sivagnanam; Vangnai, Alisa S

2017-05-01

This study focused on rhizospheric yeast capable of degrading a priority pollutant, 4-nitroaniline (4-NA), under drought stress. Candida sp. AVGB4 (AVGB4) inhabiting in soil was isolated and characterized with plant-growth promoting (PGP) traits. 4-NA-dependent growth kinetic and biodegradation kinetics were analyzed and revealed 4-NA complete degradation and tolerance property. AVGB4 proliferation, PGP activities, and 4-NA degradation activity were well maintained under drought stress induced by PEG-6000 incorporation, and could be strengthened in the presence of succinate, an organic compound generally found in plant root exudates. The in vitro experiments proved that AVGB4 significantly enhanced plant growth and increased the shoot and root biomass of Vigna radiata plant in the absence or presence of 4-NA. The overall results including cytogenotoxicity and phytotoxicity test with legumes indicated that not only AVGB4 was capable of 4-NA detoxification facilitating plants to cope with chemical-toxicity stress, but it also has advantageous role in promoting plant growth and sustainable rhizoremediation of 4-NA contaminated sites. Copyright © 2017 Elsevier Inc. All rights reserved.

Brain GLUT4 Knockout Mice Have Impaired Glucose Tolerance, Decreased Insulin Sensitivity, and Impaired Hypoglycemic Counterregulation

PubMed Central

Reno, Candace M.; Puente, Erwin C.; Sheng, Zhenyu; Daphna-Iken, Dorit; Bree, Adam J.; Routh, Vanessa H.; Kahn, Barbara B.

2017-01-01

GLUT4 in muscle and adipose tissue is important in maintaining glucose homeostasis. However, the role of insulin-responsive GLUT4 in the central nervous system has not been well characterized. To assess its importance, a selective knockout of brain GLUT4 (BG4KO) was generated by crossing Nestin-Cre mice with GLUT4-floxed mice. BG4KO mice had a 99% reduction in GLUT4 protein expression throughout the brain. Despite normal feeding and fasting glycemia, BG4KO mice were glucose intolerant, demonstrated hepatic insulin resistance, and had reduced glucose uptake in the brain. In response to hypoglycemia, BG4KO mice had impaired glucose sensing, noted by impaired epinephrine and glucagon responses and impaired c-fos activation in the hypothalamic paraventricular nucleus. Moreover, in vitro glucose sensing of glucose-inhibitory neurons from the ventromedial hypothalamus was impaired in BG4KO mice. In summary, BG4KO mice are glucose intolerant, insulin resistant, and have impaired glucose sensing, indicating a critical role for brain GLUT4 in sensing and responding to changes in blood glucose. PMID:27797912

Upregulated miR-29b promotes neuronal cell death by inhibiting Bcl2L2 after ischemic brain injury.

PubMed

Shi, Guodong; Liu, Yang; Liu, Tielong; Yan, Wangjun; Liu, Xiaowei; Wang, Yuan; Shi, Jiangang; Jia, Lianshun

2012-01-01

It is increasingly clear that microRNAs (miRNAs) play an important role in controlling cell survival. However, the functional significance of miRNAs in ischemic brain injury remains poorly understood. In the present study, we assayed the expression levels of miR-29b after ischemic brain injury, and defined the target genes and biological functions of miR-29b. We found that the miR-29b levels were significantly increased in rat brain after transient middle cerebral artery occlusion and neurons after oxygen-glucose deprivation. Moreover, ectopic expression of miR-29b promoted neuronal cell death, whereas its repression decreased cell death. Furthermore, we verified that miR-29b directly targeted and inhibited Bcl2L2 gene expression, and then increased neuronal cell death. Importantly, Bcl2L2 overexpression rescued neuronal cell death induced by miR-29b. These results suggest an important role of miR-29b in regulating neuronal cell death, thus offering a new target for the development of therapeutic agents against ischemic brain injury.

Apigenin protects blood-brain barrier and ameliorates early brain injury by inhibiting TLR4-mediated inflammatory pathway in subarachnoid hemorrhage rats.

PubMed

Zhang, Tingting; Su, Jingyuan; Guo, Bingyu; Wang, Kaiwen; Li, Xiaoming; Liang, Guobiao

2015-09-01

Early brain injury (EBI) following subarachnoid hemorrhage (SAH) is associated with high morbidity and mortality. Inflammation has been considered as the major contributor to brain damage after SAH. SAH induces a systemic increase in pro-inflammatory cytokines and chemokines. Disruption of blood-brain barrier (BBB) facilitates the influx of inflammatory cells. It has been reported that the activation of toll-like receptor 4 (TLR4)/NF-κB signaling pathway plays a vital role in the central nervous system diseases. Apigenin, a common plant flavonoid, possesses anti-inflammation effect. In this study, we focused on the effects of apigenin on EBI following SAH and its anti-inflammation mechanism. Our results showed that apigenin (20mg/kg) administration significantly attenuated EBI (including brain edema, BBB disruption, neurological deficient, severity of SAH, and cell apoptosis) after SAH in rats by suppressing the expression of TLR4, NF-κB and their downstream pro-inflammatory cytokines in the cortex and by up-regulating the expression of tight junction proteins of BBB. Double immunofluorescence staining demonstrated that TLR4 was activated following SAH in neurons, microglia cells, and endothelial cells but not in astrocytes. Apigenin could suppress the activation of TLR4 induced by SAH and inhibit apoptosis of cells in the cortex. These results suggested that apigenin could attenuate EBI after SAH in rats by suppressing TLR4-mediated inflammation and protecting against BBB disruption. Copyright © 2015 Elsevier B.V. All rights reserved.

Conformation Changes, N-terminal Involvement, and cGMP Signal Relay in the Phosphodiesterase-5 GAF Domain*

PubMed Central

Wang, Huanchen; Robinson, Howard; Ke, Hengming

2010-01-01

The activity of phosphodiesterase-5 (PDE5) is specific for cGMP and is regulated by cGMP binding to GAF-A in its regulatory domain. To better understand the regulatory mechanism, x-ray crystallographic and biochemical studies were performed on constructs of human PDE5A1 containing the N-terminal phosphorylation segment, GAF-A, and GAF-B. Superposition of this unliganded GAF-A with the previously reported NMR structure of cGMP-bound PDE5 revealed dramatic conformational differences and suggested that helix H4 and strand B3 probably serve as two lids to gate the cGMP-binding pocket in GAF-A. The structure also identified an interfacial region among GAF-A, GAF-B, and the N-terminal loop, which may serve as a relay of the cGMP signal from GAF-A to GAF-B. N-terminal loop 98–147 was physically associated with GAF-B domains of the dimer. Biochemical analyses showed an inhibitory effect of this loop on cGMP binding and its involvement in the cGMP-induced conformation changes. PMID:20861010

Conformation Changes N-terminal Involvement and cGMP Signal Relay in the Phosphodiesterase-5 GAF Domain

DOE Office of Scientific and Technical Information (OSTI.GOV)

H Wang; H Robinson; H Ke

2011-12-31

The activity of phosphodiesterase-5 (PDE5) is specific for cGMP and is regulated by cGMP binding to GAF-A in its regulatory domain. To better understand the regulatory mechanism, x-ray crystallographic and biochemical studies were performed on constructs of human PDE5A1 containing the N-terminal phosphorylation segment, GAF-A, and GAF-B. Superposition of this unliganded GAF-A with the previously reported NMR structure of cGMP-bound PDE5 revealed dramatic conformational differences and suggested that helix H4 and strand B3 probably serve as two lids to gate the cGMP-binding pocket in GAF-A. The structure also identified an interfacial region among GAF-A, GAF-B, and the N-terminal loop, whichmore » may serve as a relay of the cGMP signal from GAF-A to GAF-B. N-terminal loop 98-147 was physically associated with GAF-B domains of the dimer. Biochemical analyses showed an inhibitory effect of this loop on cGMP binding and its involvement in the cGMP-induced conformation changes.« less

New insights into selective PDE4D inhibitors: 3-(Cyclopentyloxy)-4-methoxybenzaldehyde O-(2-(2,6-dimethylmorpholino)-2-oxoethyl) oxime (GEBR-7b) structural development and promising activities to restore memory impairment.

PubMed

Brullo, Chiara; Ricciarelli, Roberta; Prickaerts, Jos; Arancio, Ottavio; Massa, Matteo; Rotolo, Chiara; Romussi, Alessia; Rebosio, Claudia; Marengo, Barbara; Pronzato, Maria Adelaide; van Hagen, Britt T J; van Goethem, Nick P; D'Ursi, Pasqualina; Orro, Alessandro; Milanesi, Luciano; Guariento, Sara; Cichero, Elena; Fossa, Paola; Fedele, Ernesto; Bruno, Olga

2016-11-29

Phosphodiesterase type 4D (PDE4D) has been indicated as a promising target for treating neurodegenerative pathologies such as Alzheimer's Disease (AD). By preventing cAMP hydrolysis, PDE4 inhibitors (PDE4Is) increase the cAMP response element-binding protein (CREB) phosphorylation, synaptic plasticity and long-term memory formation. Pharmacological and behavioral studies on our hit GEBR-7b demonstrated that selective PDE4DIs could improve memory without causing emesis and sedation. The hit development led to new molecule series, herein reported, characterized by a catechol structure bonded to five member heterocycles. Molecular modeling studies highlighted the pivotal role of a polar alkyl chain in conferring selective enzyme interaction. Compound 8a showed PDE4D3 selective inhibition and was able to increase intracellular cAMP levels in neuronal cells, as well as in the hippocampus of freely moving rats. Furthermore, 8a was able to readily cross the blood-brain barrier and enhanced memory performance in mice without causing any emetic-like behavior. These data support the view that PDE4D is an adequate molecular target to restore memory deficits in different neuropathologies, including AD, and also indicate compound 8a as a promising candidate for further preclinical development. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Creative music therapy to promote brain structure, function, and neurobehavioral outcomes in preterm infants: a randomized controlled pilot trial protocol.

PubMed

Haslbeck, Friederike Barbara; Bucher, Hans-Ulrich; Bassler, Dirk; Hagmann, Cornelia

2017-01-01

Preterm birth is associated with increased risk of neurological impairment and deficits in cognition, motor function, and behavioral problems. Limited studies indicate that multi-sensory experiences support brain development in preterm infants. Music appears to promote neurobiological processes and neuronal learning in the human brain. Creative music therapy (CMT) is an individualized, interactive therapeutic approach based on the theory and methods of Nordoff and Robbins. CMT may promote brain development in preterm infants via concurrent interaction and meaningful auditory stimulation. We hypothesize that preterm infants who receive creative music therapy during neonatal intensive care admission will have developmental benefits short- and long-term brain function. A prospective, randomized controlled single-center pilot trial involving 60 clinically stable preterm infants under 32 weeks of gestational age is conducted in preparation for a multi-center trial. Thirty infants each are randomized to either standard neonatal intensive care or standard care with CMT. Music therapy intervention is approximately 20 min in duration three times per week. A trained music therapist sings for the infants in lullaby style, individually entrained and adjusted to the infant's rhythm and affect. Primary objectives of this study are feasibility of protocol implementation and investigating the potential mechanism of efficacy for this new intervention. To examine the effect of this new intervention, non-invasive, quantitative magnetic resonance imaging (MRI) methods at corrected age and standardized neurodevelopmental assessments using the Bayley Scales of Infant and Toddler Development third edition at a corrected age of 24 months and Kaufman Assessment Battery for Children at 5 years will be performed. All assessments will be performed and analyzed by blinded experts. To our knowledge, this is the first randomized controlled clinical trial to systematically examine possible

Deletion of aquaporin-4 is neuroprotective during the acute stage of micro traumatic brain injury in mice.

PubMed

Liang, Fengyin; Luo, Chuanming; Xu, Guangqing; Su, Fengjuan; He, Xiaofei; Long, Simei; Ren, Huixia; Liu, Yaning; Feng, Yanqing; Pei, Zhong

2015-06-26

Micro traumatic brain injury (TBI) is the most common type of brain injury, but the mechanisms underlying it are poorly understood. Aquaporin-4 (AQP4) is a water channel expressed in astrocyte end-feet, which plays an important role in brain edema. However, little is known about the role of AQP4 in micro TBI. Here, we examined the role of AQP4 in the pathogenesis of micro TBI in a closed-skull brain injury model, using two-photon microscopy. Our results indicate that AQP4 deletion reduced cell death, water content, astrocyte swelling and lesion volume during the acute stage of micro TBI. Our data revealed that astrocyte swelling is a decisive pathophysiological factor in the acute phase of this form of micro brain injury. Thus, treatments that inhibit AQP4 could be used as a neuroprotective strategy for micro TBI. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Pharmacological similarities between native brain and heterologously expressed α4β2 nicotinic receptors

PubMed Central

Shafaee, Navid; Houng, McCann; Truong, Anthony; Viseshakul, Nareerat; Figl, Antonio; Sandhu, Sumandeep; Forsayeth, John R; Dwoskin, Linda P; Crooks, Peter A; Cohen, Bruce N

1999-01-01

We studied the pharmacological properties of native rat brain and heterologously expressed rat α4β2 nicotinic receptors immunoprecipitated onto a fixed substrate with the anti-α4 antibody mAb 299.Immunodepletion with the anti-β2 antibody mAb 270 showed that 89% of the mAb-299-precipitated rat brain receptors contained β2.The association and dissociation rate constants for 30 pM ±[3H]-epibatidine binding to α4β2 receptors expressed in oocytes were 0.02±0.01 and 0.03±0.01 min−1 (±standard error, degrees of freedom=7–8) at 20–23°C.The Hill coefficients for ±[3H]epibatidine binding to the native brain, α4β2 receptors expressed in oocytes, and α4β2 receptors expressed in CV-1 cells (using recombinant adenovirus) were 0.69–0.70 suggesting a heterogeneous receptor population. Fits of the ±[3H]-epibatidine concentration-binding data to a two-site model gave KD s of 8–30 and 560–1,200 pM. The high-affinity sites comprised 73–74% of the native brain and oocyte α4β2 receptor population, 85% of the CV-1 α4β2 receptor population.The expression of rat α4β2 receptors in CV-1 cells using vaccinia viral infection-transfection resulted in a more homogeneous receptor population (Hill coefficient of 1.0±0.2). Fits of the ±[3H]-epibatidine binding data to a single-site model gave a KD of 40±3 pM.DHβE (IC50=260–470 nM) and the novel nicotine analogue NDNI (IC50=7–10 μM) inhibited 30 pM±[3H]-epibatidine binding to the native brain and heterologously expressed α4β2 receptors equally well.The results show that α4β2-containing nicotinic receptors in the rat brain and heterologously expressed rat α4β2 receptors have similar affinities for ±[3H]-epibatidine, DHβE, and NDNI. PMID:10578144

Does Stereotactic Radiosurgery Have a Role in the Management of Patients Presenting With 4 or More Brain Metastases?

PubMed

Soike, Michael H; Hughes, Ryan T; Farris, Michael; McTyre, Emory R; Cramer, Christina K; Bourland, J D; Chan, Michael D

2018-06-01

Stereotactic radiosurgery (SRS) and whole brain radiation therapy (WBRT) are effective treatments for management of brain metastases. Prospective trials comparing the 2 modalities in patients with fewer than 4 brain metastases demonstrate that overall survival (OS) is similar. Intracranial failure is more common after SRS, while WBRT is associated with neurocognitive decline. As technology has advanced, fewer technical obstacles remain for treating patients with 4 or more brain metastases with SRS, but level I data supporting its use are lacking. Observational prospective studies and retrospective series indicate that in patients with 4 or more brain metastases, performance status, total volume of intracranial disease, histology, and rate of development of new brain metastases predict outcomes more accurately than the number of brain metastases. It may be reasonable to initially offer SRS to some patients with 4 or more brain metastases. Initiating therapy with SRS avoids the acute and late sequelae of WBRT. Multiple phase III trials of SRS vs WBRT, both currently open or under development, are directly comparing quality of life and OS for patients with 4 or more brain metastases to help answer the question of SRS appropriateness for these patients.

[Comparison of the effects of phosphodiesterase III inhibitors, milrinone and olprinone, in infant corrective cardiac surgery].

PubMed

Sakimura, Shotaro; Yoshino, Jun; Izumi, Kaoru; Jimi, Nobuo; Sumiyoshi, Rieko; Mizuno, Keiichiro

2013-05-01

Clinical characteristics of phosphodiesterase (PDE) III inhibitors, milrinone and olprinone, is not fully understood in infants. We therefore retrospectively examined the hemodynamics, metabolism, and oxygenation of two different PDE III inhibitors in infants undergoing radical correction of ventricular septal defect with pulmonary hypertension. Twenty-six infants with pulmonary hypertension undergoing ventricular septum defect repair were retrospectively allocated to milrinone group (n= 13)and olprinone group(n=13). Hemodynamic parameters, acid-base balance, oxygenation and postoperative mechanical ventilation period were compared between the two groups at induction of anesthesia, weaning from cardiopulmonary bypass and the end of the surgery. The patients' mean age was 4.4 +/- 2.5 months. Demographic data were almost similar between the two groups. Milrinone and olprinone were administered at the rates of 0.5 and 0.3 microg x kg-1 x min-1 at the end of surgery, respectively. Hemodynamic variables, acid-base balance, Pao2 /FIo2 ratio and mechanical ventilation period were not significantly different between the two groups. No adverse side effects were observed during the study period. The effects of the PDE III inhibitors, milrinone and olprinone, on hemodynamic parameters, acid-base balance and oxygenation were similar in these infants. Both milrinone and olprinone could be used safely in infant cardiac surgery.

Chemical exchange saturation transfer MRI contrast in the human brain at 9.4 T.

PubMed

Zaiss, Moritz; Schuppert, Mark; Deshmane, Anagha; Herz, Kai; Ehses, Philipp; Füllbier, Lars; Lindig, Tobias; Bender, Benjamin; Ernemann, Ulrike; Scheffler, Klaus

2018-06-15

The high chemical shift separation at 9.4 T allows for selective saturation of proton pools in exchange with water protons. For the first time, highly selective and comprehensive chemical exchange saturation transfer (CEST) experiments were performed in the human brain at 9.4 T. This work provides insight into CEST signals in the human brain in comparison with existing animal studies, as well as with CEST effects in vivo at lower field strengths. A novel snapshot-CEST method for human brain scans at 9.4 T was optimized and employed for highly-spectrally-resolved (95 offsets) CEST measurements in healthy subjects and one brain tumor patient. Reproducibility and stability between scans was verified in grey and white matter after B 0 , B 1 , and motion correction of the acquired 3D CEST volumes. Two-step Lorentzian fitting was used to further improve separation of spectrally discernible signals to create known and novel CEST contrast maps at 9.4 T. At a saturation power of B 1  = 0.5 μT most selective CEST effects could be obtained in the human brain with high inter-scan reproducibility. While contrast behavior of previously measured signals at lower field, namely amide-, guanidyl- and NOE-CEST effects, could be reproduced, novel signals at 2.7 ppm, and -1.6 ppm could be verified in healthy subjects and in a brain tumor patient for the first time. High spectral resolution chemical exchange saturation transfer at 9.4 T allows deeper insights into the Z-spectrum structure of the human brain, and provides many different contrasts showing different correlations in healthy tissue and in tumor-affected areas of the brain, generating hypotheses for future investigations of in-vivo-CEST at UHF. Copyright © 2018 Elsevier Inc. All rights reserved.

Protein Kinase Mitogen-activated Protein Kinase Kinase Kinase Kinase 4 (MAP4K4) Promotes Obesity-induced Hyperinsulinemia.

PubMed

Roth Flach, Rachel J; Danai, Laura V; DiStefano, Marina T; Kelly, Mark; Menendez, Lorena Garcia; Jurczyk, Agata; Sharma, Rohit B; Jung, Dae Young; Kim, Jong Hun; Kim, Jason K; Bortell, Rita; Alonso, Laura C; Czech, Michael P

2016-07-29

Previous studies revealed a paradox whereby mitogen-activated protein kinase kinase kinase kinase 4 (Map4k4) acted as a negative regulator of insulin sensitivity in chronically obese mice, yet systemic deletion of Map4k4 did not improve glucose tolerance. Here, we report markedly reduced glucose-responsive plasma insulin and C-peptide levels in whole body Map4k4-depleted mice (M4K4 iKO) as well as an impaired first phase of insulin secretion from islets derived from M4K4 iKO mice ex vivo After long-term high fat diet (HFD), M4K4 iKO mice pancreata also displayed reduced β cell mass, fewer proliferating β cells and reduced islet-specific gene mRNA expression compared with controls, although insulin content was normal. Interestingly, the reduced plasma insulin in M4K4 iKO mice exposed to chronic (16 weeks) HFD was not observed in response to acute HFD challenge or short term treatment with the insulin receptor antagonist S961. Furthermore, the improved insulin sensitivity in obese M4K4 iKO mice was abrogated by high exogenous insulin over the course of a euglycemic clamp study, indicating that hypoinsulinemia promotes insulin sensitivity in chronically obese M4K4 iKO mice. These results demonstrate that protein kinase Map4k4 drives obesity-induced hyperinsulinemia and insulin resistance in part by promoting insulin secretion from β cells in mice. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Toll-like receptor 4 enhancement of non-NMDA synaptic currents increases dentate excitability after brain injury.

PubMed

Li, Ying; Korgaonkar, Akshata A; Swietek, Bogumila; Wang, Jianfeng; Elgammal, Fatima S; Elkabes, Stella; Santhakumar, Vijayalakshmi

2015-02-01

Concussive brain injury results in neuronal degeneration, microglial activation and enhanced excitability in the hippocampal dentate gyrus, increasing the risk for epilepsy and memory dysfunction. Endogenous molecules released during injury can activate innate immune responses including toll-like receptor 4 (TLR4). Recent studies indicate that immune mediators can modulate neuronal excitability. Since non-specific agents that reduce TLR4 signaling can limit post-traumatic neuropathology, we examined whether TLR4 signaling contributes to early changes in dentate excitability after brain injury. Concussive brain injury caused a transient increase in hippocampal TLR4 expression within 4h, which peaked at 24h. Post-injury increase in TLR4 expression in the dentate gyrus was primarily neuronal and persisted for one week. Acute, in vitro treatment with TLR4 ligands caused bidirectional modulation of dentate excitability in control and brain-injured rats, with a reversal in the direction of modulation after brain injury. TLR4 antagonists decreased, and agonist increased, afferent-evoked dentate excitability one week after brain injury. NMDA receptor antagonist did not occlude the ability of LPS-RS, a TLR4 antagonist, to decrease post-traumatic dentate excitability. LPS-RS failed to modulate granule cell NMDA EPSCs but decreased perforant path-evoked non-NMDA EPSC peak amplitude and charge transfer in both granule cells and mossy cells. Our findings indicate an active role for TLR4 signaling in early post-traumatic dentate hyperexcitability. The novel TLR4 modulation of non-NMDA glutamatergic currents, identified herein, could represent a general mechanism by which immune activation influences neuronal excitability in neurological disorders that recruit sterile inflammatory responses. Copyright © 2014 Elsevier Inc. All rights reserved.

Dietary cholesterol promotes repair of demyelinated lesions in the adult brain.

PubMed

Berghoff, Stefan A; Gerndt, Nina; Winchenbach, Jan; Stumpf, Sina K; Hosang, Leon; Odoardi, Francesca; Ruhwedel, Torben; Böhler, Carolin; Barrette, Benoit; Stassart, Ruth; Liebetanz, David; Dibaj, Payam; Möbius, Wiebke; Edgar, Julia M; Saher, Gesine

2017-01-24

Multiple Sclerosis (MS) is an inflammatory demyelinating disorder in which remyelination failure contributes to persistent disability. Cholesterol is rate-limiting for myelin biogenesis in the developing CNS; however, whether cholesterol insufficiency contributes to remyelination failure in MS, is unclear. Here, we show the relationship between cholesterol, myelination and neurological parameters in mouse models of demyelination and remyelination. In the cuprizone model, acute disease reduces serum cholesterol levels that can be restored by dietary cholesterol. Concomitant with blood-brain barrier impairment, supplemented cholesterol directly supports oligodendrocyte precursor proliferation and differentiation, and restores the balance of growth factors, creating a permissive environment for repair. This leads to attenuated axon damage, enhanced remyelination and improved motor learning. Remarkably, in experimental autoimmune encephalomyelitis, cholesterol supplementation does not exacerbate disease expression. These findings emphasize the safety of dietary cholesterol in inflammatory diseases and point to a previously unrecognized role of cholesterol in promoting repair after demyelinating episodes.

Dietary cholesterol promotes repair of demyelinated lesions in the adult brain

PubMed Central

Berghoff, Stefan A.; Gerndt, Nina; Winchenbach, Jan; Stumpf, Sina K.; Hosang, Leon; Odoardi, Francesca; Ruhwedel, Torben; Böhler, Carolin; Barrette, Benoit; Stassart, Ruth; Liebetanz, David; Dibaj, Payam; Möbius, Wiebke; Edgar, Julia M.; Saher, Gesine

2017-01-01

Multiple Sclerosis (MS) is an inflammatory demyelinating disorder in which remyelination failure contributes to persistent disability. Cholesterol is rate-limiting for myelin biogenesis in the developing CNS; however, whether cholesterol insufficiency contributes to remyelination failure in MS, is unclear. Here, we show the relationship between cholesterol, myelination and neurological parameters in mouse models of demyelination and remyelination. In the cuprizone model, acute disease reduces serum cholesterol levels that can be restored by dietary cholesterol. Concomitant with blood-brain barrier impairment, supplemented cholesterol directly supports oligodendrocyte precursor proliferation and differentiation, and restores the balance of growth factors, creating a permissive environment for repair. This leads to attenuated axon damage, enhanced remyelination and improved motor learning. Remarkably, in experimental autoimmune encephalomyelitis, cholesterol supplementation does not exacerbate disease expression. These findings emphasize the safety of dietary cholesterol in inflammatory diseases and point to a previously unrecognized role of cholesterol in promoting repair after demyelinating episodes. PMID:28117328

Measurement of serum, liver, and brain cytokine induction, thiamine levels, and hepatopathology in rats exposed to a 4-day alcohol binge protocol.

PubMed

Zahr, Natalie M; Luong, Richard; Sullivan, Edith V; Pfefferbaum, Adolf

2010-11-01

 In rodent and human studies, ethanol (EtOH) exposure is associated with elevated brain levels of the magnetic resonance spectroscopy (MRS) signal representing choline-containing compounds (Cho). One interpretation of elevated brain Cho is that it is a marker of neuroinflammation, and some evidence suggests that EtOH exposure promotes neuroinflammation. This study aimed to determine whether binge EtOH exposure (intragastric 3 g/kg 25% EtOH every 8 hours for 4 days) would induce the expression of certain cytokines in blood, liver, or brain, thereby supporting the neuroinflammation hypothesis of elevated Cho. Ten of 18 wild-type male Wistar rats (~322 g at baseline) were exposed to EtOH and attained average blood alcohol levels of ~315 mg/dl across 4 days. Blood for cytokine immunoassays was collected at baseline, after 5 doses of EtOH (binge), and immediately preceding euthanasia either 4 or 24 hours after the last dose of EtOH. Blood was additionally assayed for the levels of thiamine and liver enzymes; liver histopathology was performed postmortem; and tissue from liver and 6 brain regions was assayed for the potential induction of 7 cytokines. There were no group effects on the levels of thiamine or its phosphate derivatives, thiamine monophosphate or thiamine diphosphate. ANOVAs of liver enzyme levels indicated that only alkaline phosphatase (ALP) levels were higher in the EtOH group than in control group at binge; ALP elevations, however, are difficult to explain in the absence of changes in the levels of additional liver enzymes. Postmortem liver pathology provided evidence for minimal microvesicular lipidosis and portocentric fibrosis in the EtOH group. Group effects on the levels of the measured cytokines in the blood (TNF-α, IFN-γ, IL-1β, IL-4, IL-5, IL-13, and GRO/CXCL1) were not significant. Similarly, postmortem evaluation of liver cytokines did not reveal group effects. Postmortem evaluation of the 7 cytokines in 6 brain regions (anterior

Inhibition of calmodulin-dependent phosphodiesterase induces apoptosis in human leukemic cells.

PubMed Central

Jiang, X; Li, J; Paskind, M; Epstein, P M

1996-01-01

Cytosolic extracts from a human lymphoblastoid B-cell line, RPMI-8392, established from a patient with acute lymphocytic leukemia, contain two major forms of cyclic nucleotide phosphodiesterase (PDE): Ca2+-calmodulin dependent PDE (PDE1) and cAMP-specific PDE (PDE4). In contrast, normal quiescent human peripheral blood lymphocytes (HPBL) are devoid of PDE1 activity [Epstein, P. M., Moraski, S., Jr., and Hachisu, R. (1987) Biochem. J. 243, 533-539]. Using reverse transcription-polymerase chain reaction (RT-PCR), we show that the mRNA encoding the 63-kDa form of PDE1 (PDE1B1) is expressed in RPMI-8392 cells, but not in normal, resting HPBL. This mRNA is, however, induced in HPBL following mitogenic stimulation by phytohemagglutinin (PHA). Also using RT-PCR, the full open reading frame for human PDE1B1 cDNA was cloned from RPMI-8392 cells and it encodes a protein of 536 amino acids with 96% identity to bovine, rat, and mouse species. RT-PCR also identifies the presence of PDE1B1 in other human lymphoblastoid and leukemic cell lines of B- (RPMI-1788, Daudi) and T-(MOLT-4, NA, Jurkat) cell origin. Inhibition of PDE1 or PDE4 activity by selective inhibitors induced RPMI-8392 cells, as well as the other cell lines, to undergo apoptosis. Culture of RPMI-8392 cells with an 18-bp phosphorothioate antisense oligodeoxynucleotide, targeted against the translation initiation region of the RPMI-8392 mRNA, led to a specific reduction in the amount of PDE1B1 mRNA after 1 day, and its disappearance after 2 days, and induced apoptosis in these cells in a sequence specific manner. This suggests that PDEs, particularly PDE1B1, because its expression is selective, may be useful targets for inducing the death of leukemic cells. Images Fig. 1 Fig. 3 Fig. 5 Fig. 6 PMID:8855339

Transactivation of the proximal promoter of human oxytocin gene by TR4 orphan receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, C.-P.; Lee, Y.-F.; Chang, C.

2006-12-08

The human testicular receptor 4 (TR4) shares structural homology with members of the nuclear receptor superfamily. Some other members of this superfamily were able to regulate the transcriptional activity of the human oxytocin (OXT) promoter by binding to the first DR0 regulatory site. However, little investigation was conducted systematically in the study of the second dDR4 site of OXT proximal promoter, and the relationship between the first and the second sites of OXT promoter. Here, we demonstrated for the first time that TR4 could increase the proximal promoter activity of the human OXT gene via DR0, dDR4, and OXT (bothmore » DR0 and dDR4) elements, respectively. TR4 might induce OXT gene expression through the OXT element in a dose-dependent manner. However, there is no synergistic effect between DR0 and dDR4 elements during TR4 transactivation. Taken together, these results suggested that TR4 should be one of important regulators of OXT gene expression.« less

[Application of precursor ion scanning method in rapid screening of illegally added phosphodiesterase-5 inhibitors and their unknown derivatives in Chinese traditional patent medicines and health foods].

PubMed

Sun, Jing; Cao, Ling; Feng, Youlong; Tan, Li

2014-11-01

The compounds with similar structure often have similar pharmacological activities. So it is a trend for illegal addition that new derivatives of effective drugs are synthesized to avoid the statutory test. This bring challenges to crack down on illegal addition behavior, however, modified derivatives usually have similar product ions, which allow for precursor ion scanning. In this work, precursor ion scanning mode of a triple quadrupole mass spectrometer was first applied to screen illegally added drugs in complex matrix such as Chinese traditional patent medicines and healthy foods. Phosphodiesterase-5 inhibitors were used as experimental examples. Through the analysis of the structure and mass spectrum characteristics of the compounds, phosphodiesterase-5 inhibitors were classified, and their common product ions were screened by full scan of product ions of typical compounds. Then high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method with precursor ion scanning mode was established based on the optimization of MS parameters. The effect of mass parameters and the choice of fragment ions were also studied. The method was applied to determine actual samples and further refined. The results demonstrated that this method can meet the need of rapid screening of unknown derivatives of phosphodiesterase-5 inhibitors in complex matrix, and prevent unknown derivatives undetected. This method shows advantages in sensitivity, specificity and efficiency, and is worth to be further investigated.

Physiological Ischemic Training Promotes Brain Collateral Formation and Improves Functions in Patients with Acute Cerebral Infarction.

PubMed

Zhen, Xiaoyue; Zheng, Yu; Hong, Xunning; Chen, Yan; Gu, Ping; Tang, Jinrong; Cheng, Hong; Yuan, Ti-Fei; Lu, Xiao

2016-01-01

To observe the effectiveness and mechanisms of physiological ischemic training (PIT) on brain cerebral collateral formation and functional recovery in patients with acute cerebral infarction. 20 eligible patients with acute cerebral infarction were randomly assigned to either PIT group ( n  = 10) or Control group ( n  = 10). Both groups received 4 weeks of routine rehabilitation therapy, while an additional session of PIT, which consisted of 10 times of maximal voluntary isometric handgrip for 1 min followed by 1 min rest, was prescribed for patients in the PIT groups. Each patient was trained with four sections a day and 5 days a week for 4 weeks. The Fugl-Meyer Assessment (FMA), the Modified Barthel Index (MBI), and the short-form 36-item health survey questionnaire (SF-36) were applied for the evaluation of motor impairment, activity of daily living, and quality of life at the baseline and endpoint. MRI was applied to detect the collateral formation in the brain. The concentration of vascular endothelial growth factor (VEGF) and endothelial progenitor cells (EPCs) number in plasma were also tested at the endpoint. Demographic data were consistent between experimental groups. At the endpoint, the scores of the FMA, MBI, and SF-36 were significantly higher than that at baseline. As compared to the Control group, the score of FMA and SF-36 in PIT group was significantly higher, while no significant difference was detected between groups in terms of MBI. Both groups had significantly higher cerebral blood flow (CBF) level at endpoint as compared to that at baseline. Moreover, the CBF level was even higher in the PIT group as compared to that in the Control group after 4 weeks of training. The same situations were also found in the plasma VEGF and EPCs assessment. In addition, positive correlations were found between FMA score and CBF level ( r  = 0.686, p  < 0.01), CBF level and VEGF concentration ( r  = 0.675, p  < 0.01), and

Fingolimod inhibits brain atrophy and promotes brain-derived neurotrophic factor in an animal model of multiple sclerosis.

PubMed

Smith, Paul A; Schmid, Cindy; Zurbruegg, Stefan; Jivkov, Magali; Doelemeyer, Arno; Theil, Diethilde; Dubost, Valérie; Beckmann, Nicolau

2018-05-15

Longitudinal brain atrophy quantification is a critical efficacy measurement in multiple sclerosis (MS) clinical trials and the determination of No Evidence of Disease Activity (NEDA). Utilising fingolimod as a clinically validated therapy we evaluated the use of repeated brain tissue volume measures during chronic experimental autoimmune encephalomyelitis (EAE) as a new preclinical efficacy measure. Brain volume changes were quantified using magnetic resonance imaging (MRI) at 7 Tesla and correlated to treatment-induced brain derived neurotrophic factor (BDNF) measured in blood, cerebrospinal fluid, spinal cord and brain. Serial brain MRI measurements revealed slow progressive brain volume loss in vehicle treated EAE mice despite a stable clinical score. Fingolimod (1 mg/kg) significantly ameliorated brain tissue atrophy in the cerebellum and striatum when administered from established EAE disease onwards. Fingolimod-dependent tissue preservation was associated with induction of BDNF specifically within the brain and co-localized with neuronal soma. In contrast, therapeutic teriflunomide (3 mg/kg) treatment failed to inhibit CNS autoimmune mediated brain degeneration. Finally, weekly anti-IL-17A antibody (15 mg/kg) treatment was highly efficacious and preserved whole brain, cerebellum and striatum volume. Fingolimod-mediated BDNF increases within the CNS may contribute to limiting progressive tissue loss during chronic neuroinflammation. Copyright © 2018 Elsevier B.V. All rights reserved.

Toll-like receptor 4 knockout ameliorates neuroinflammation due to lung-brain interaction in mechanically ventilated mice.

PubMed

Chen, Ting; Chen, Chang; Zhang, Zongze; Zou, Yufeng; Peng, Mian; Wang, Yanlin

2016-08-01

Toll-like receptor 4 (TLR4) is a crucial receptor in the innate immune system, and increasing evidence supports its role in inflammation, stress, and tissue injury, including injury to the lung and brain. We aimed to investigate the effects of TLR4 on neuroinflammation due to the lung-brain interaction in mechanically ventilated mice. Male wild-type (WT) C57BL/6 and TLR4 knockout (TLR4 KO) mice were divided into three groups: (1) control group (C): spontaneous breathing; (2) anesthesia group (A): spontaneous breathing under anesthesia; and (3) mechanical ventilation group (MV): 6h of MV under anesthesia. The behavioral responses of mice were tested with fear conditioning tests. The histological changes in the lung and brain were assessed using hematoxylin-eosin (HE) staining. The level of TLR4 mRNA in tissue was measured using reverse transcription-polymerase chain reaction (RT-PCR). The levels of inflammatory cytokines were measured with an enzyme-linked immunosorbent assay (ELISA). Microgliosis, astrocytosis, and the TLR4 immunoreactivity in the hippocampus were measured by double immunofluorescence. MV mice exhibited impaired cognition, and this impairment was less severe in TLR4 KO mice than in WT mice. In WT mice, MV increased TLR4 mRNA expression in the lung and brain. MV induced mild lung injury, which was prevented in TLR4 KO mice. MV mice exhibited increased levels of inflammatory cytokines, increased microglia and astrocyte activation. Microgliosis was alleviated in TLR4 KO mice. MV mice exhibited increased TLR4 immunoreactivity, which was expressed in microglia and astrocytes. These results demonstrate that TLR4 is involved in neuroinflammation due to the lung-brain interaction and that TLR4 KO ameliorates neuroinflammation due to lung-brain interaction after prolonged MV. In addition, Administration of a TLR4 antagonist (100μg/mice) to WT mice also significantly attenuated neuroinflammation of lung-brain interaction due to prolonged MV. TLR4 antagonism

Brain GLUT4 Knockout Mice Have Impaired Glucose Tolerance, Decreased Insulin Sensitivity, and Impaired Hypoglycemic Counterregulation.

PubMed

Reno, Candace M; Puente, Erwin C; Sheng, Zhenyu; Daphna-Iken, Dorit; Bree, Adam J; Routh, Vanessa H; Kahn, Barbara B; Fisher, Simon J

2017-03-01

GLUT4 in muscle and adipose tissue is important in maintaining glucose homeostasis. However, the role of insulin-responsive GLUT4 in the central nervous system has not been well characterized. To assess its importance, a selective knockout of brain GLUT4 (BG4KO) was generated by crossing Nestin-Cre mice with GLUT4-floxed mice. BG4KO mice had a 99% reduction in GLUT4 protein expression throughout the brain. Despite normal feeding and fasting glycemia, BG4KO mice were glucose intolerant, demonstrated hepatic insulin resistance, and had reduced glucose uptake in the brain. In response to hypoglycemia, BG4KO mice had impaired glucose sensing, noted by impaired epinephrine and glucagon responses and impaired c-fos activation in the hypothalamic paraventricular nucleus. Moreover, in vitro glucose sensing of glucose-inhibitory neurons from the ventromedial hypothalamus was impaired in BG4KO mice. In summary, BG4KO mice are glucose intolerant, insulin resistant, and have impaired glucose sensing, indicating a critical role for brain GLUT4 in sensing and responding to changes in blood glucose. © 2017 by the American Diabetes Association.

The cyclic-di-GMP phosphodiesterase BinA negatively regulates cellulose-containing biofilms in Vibrio fischeri.

PubMed

Bassis, Christine M; Visick, Karen L

2010-03-01

Bacteria produce different types of biofilms under distinct environmental conditions. Vibrio fischeri has the capacity to produce at least two distinct types of biofilms, one that relies on the symbiosis polysaccharide Syp and another that depends upon cellulose. A key regulator of biofilm formation in bacteria is the intracellular signaling molecule cyclic diguanylate (c-di-GMP). In this study, we focused on a predicted c-di-GMP phosphodiesterase encoded by the gene binA, located directly downstream of syp, a cluster of 18 genes critical for biofilm formation and the initiation of symbiotic colonization of the squid Euprymna scolopes. Disruption or deletion of binA increased biofilm formation in culture and led to increased binding of Congo red and calcofluor, which are indicators of cellulose production. Using random transposon mutagenesis, we determined that the phenotypes of the DeltabinA mutant strain could be disrupted by insertions in genes in the bacterial cellulose biosynthesis cluster (bcs), suggesting that cellulose production is negatively regulated by BinA. Replacement of critical amino acids within the conserved EAL residues of the EAL domain disrupted BinA activity, and deletion of binA increased c-di-GMP levels in the cell. Together, these data support the hypotheses that BinA functions as a phosphodiesterase and that c-di-GMP activates cellulose biosynthesis. Finally, overexpression of the syp regulator sypG induced binA expression. Thus, this work reveals a mechanism by which V. fischeri inhibits cellulose-dependent biofilm formation and suggests that the production of two different polysaccharides may be coordinated through the action of the cellulose inhibitor BinA.

Acute versus chronic administration of phosphodiesterase inhibitors on allergen-induced pulmonary cell influx in sensitized guinea-pigs.

PubMed Central

Banner, K H; Page, C P

1995-01-01

1. The aims of this study were to determine which phosphodiesterase (PDE) isoenzymes are involved in the control of eosinophil accumulation in the airways of ovalbumin (OVA)-immunized guinea-pigs by the use of isoenzyme selective inhibitors and to compare the effects of acute versus chronic administration of PDE isozyme inhibitors on pulmonary cell influx in ovalbumin-immunized guinea-pigs. 2. Guinea-pigs were sensitized and subsequently challenged with aerosolized OVA. Twenty four hours later bronchoalveolar lavage (BAL) was performed to permit assessment of inflammatory cell accumulation. A significant increase in the number of eosinophils was observed in the lavage fluid from OVA-immunized (13.6 +/- 1.4 x 10(4) ml-1 in acute experiments and 10.1 +/- 1.4 x 10(4) ml-1 in chronic experiments) animals compared with sham-treated controls (5.6 +/- 0.6 x 10(4) ml-1 in acute experiments and 5.1 +/- 0.6 x 10(4) ml-1 in chronic experiments). There was no difference in neutrophil, mononuclear cell or total cell numbers between the two groups. 3. Acute administration of a high dose of selective and non-selective PDE inhibitors by the i.p. route had no significant effect on eosinophil accumulation in the airways. 4. Chronic administration of a low dose (3 mg kg-1, i.p., twice daily for 7 days) of the type IV PDE inhibitor, RO 20-1724, and the PDE III/IV inhibitor, zardaverine, produced a significant inhibition of eosinophil accumulation (46% and 59% respectively).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7536098

Redox modulation of cellular stress response and lipoxin A4 expression by Coriolus versicolor in rat brain: Relevance to Alzheimer's disease pathogenesis.

PubMed

Trovato, A; Siracusa, R; Di Paola, R; Scuto, M; Fronte, V; Koverech, G; Luca, M; Serra, A; Toscano, M A; Petralia, A; Cuzzocrea, S; Calabrese, V

2016-03-01

Increasing evidence supports the notion that oxidative stress-driven neuroinflammation is an early pathological feature in neurodegenerative diseases. As a prominent intracellular redox system involved in neuroprotection, the vitagene system is emerging as a potential neurohormetic target for novel cytoprotective interventions. Vitagenes encode for cytoprotective heat shock proteins 70, heme oxygenase-1, thioredoxin and lipoxin A4. Emerging interest is now focusing on molecules capable of activating the vitagene system as novel therapeutic targets to minimize deleterious consequences associated with free radical-induced cell damage, such as in neurodegeneration. Mushroom-derived lipoxin A4 (LXA4) is an emerging endogenous eicosanoid able to promote resolution of inflammation, acting as an endogenous "braking signal" in the inflammatory process. Mushrooms have long been used in traditional medicine for thousands of years, being now increasingly recognized as rich source of polysaccharopeptides endowed with significant antitumor, antioxidant, antiviral, antibacterial and cytoprotective effects, thereby capable of stimulating host immune responses. Here we provide evidence of a neuroprotective action of the Coriolus mushroom when administered orally to rat. Expression of LXA4 was measured in different brain regions after oral administration of a Coriolus biomass preparation, given for 30 days. LXA4 up-regulation was associated with an increased content of redox sensitive proteins involved in cellular stress response, such as Hsp72, heme oxygenase-1 and thioredoxin. In the brain of rats receiving Coriolus, maximum induction of LXA4 was observed in cortex and hippocampus. Hsps induction was associated with no significant changes in IkBα, NFkB and COX-2 brain levels. Conceivably, activation of LXA4 signaling and modulation of stress-responsive vitagene proteins could serve as a potential therapeutic target for AD-related inflammation and neurodegenerative damage

The safety of phosphodiesterase type 5 inhibitors for erectile dysfunction.

PubMed

Ventimiglia, Eugenio; Capogrosso, Paolo; Montorsi, Francesco; Salonia, Andrea

2016-01-01

Phosphodiesterase type 5 inhibitors (PDE5Is) are the leading drugs for the treatment of erectile dysfunction (ED), being recommended as a first line treatment by both the European and US urological guidelines. PDE5Is are highly effective as compared to placebo, well tolerated and have a very low, though not negligible, rate of severe treatment-related adverse events. This paper reviews the safety profile of currently available PDE5Is, comparing them in a broad spectrum ED population and outlining a number of real-life aspects of importance in the real-life everyday clinical setting. Guidelines unanimously agree in considering PDE5Is as first line treatments for ED when well-tolerated and not contraindicated. Despite the fact that no high-grade evidence comparing the efficacy and the safety for PDE5Is is currently available, published data seem to suggest that there are no major differences in their safety profiles. Moreover, although oral PDE5Is were shown to cause more AEs than placebo, they were generally mild and well tolerated.

Large Sex Differences in Chicken Behavior and Brain Gene Expression Coincide with Few Differences in Promoter DNA-Methylation

PubMed Central

Nätt, Daniel; Agnvall, Beatrix; Jensen, Per

2014-01-01

While behavioral sex differences have repeatedly been reported across taxa, the underlying epigenetic mechanisms in the brain are mostly lacking. Birds have previously shown to have only limited dosage compensation, leading to high sex bias of Z-chromosome gene expression. In chickens, a male hyper-methylated region (MHM) on the Z-chromosome has been associated with a local type of dosage compensation, but a more detailed characterization of the avian methylome is limiting our interpretations. Here we report an analysis of genome wide sex differences in promoter DNA-methylation and gene expression in the brain of three weeks old chickens, and associated sex differences in behavior of Red Junglefowl (ancestor of domestic chickens). Combining DNA-methylation tiling arrays with gene expression microarrays we show that a specific locus of the MHM region, together with the promoter for the zinc finger RNA binding protein (ZFR) gene on chromosome 1, is strongly associated with sex dimorphism in gene expression. Except for this, we found few differences in promoter DNA-methylation, even though hundreds of genes were robustly differentially expressed across distantly related breeds. Several of the differentially expressed genes are known to affect behavior, and as suggested from their functional annotation, we found that female Red Junglefowl are more explorative and fearful in a range of tests performed throughout their lives. This paper identifies new sites and, with increased resolution, confirms known sites where DNA-methylation seems to affect sexually dimorphic gene expression, but the general lack of this association is noticeable and strengthens the view that birds do not have dosage compensation. PMID:24782041

DISC1, PDE4B, and NDE1 at the centrosome and synapse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bradshaw, Nicholas J.; Ogawa, Fumiaki; Antolin-Fontes, Beatriz

Disrupted-In-Schizophrenia 1 (DISC1) is a risk factor for schizophrenia and other major mental illnesses. Its protein binding partners include the Nuclear Distribution Factor E Homologs (NDE1 and NDEL1), LIS1, and phosphodiesterases 4B and 4D (PDE4B and PDE4D). We demonstrate that NDE1, NDEL1 and LIS1, together with their binding partner dynein, associate with DISC1, PDE4B and PDE4D within the cell, and provide evidence that this complex is present at the centrosome. LIS1 and NDEL1 have been previously suggested to be synaptic, and we now demonstrate localisation of DISC1, NDE1, and PDE4B at synapses in cultured neurons. NDE1 is phosphorylated by cAMP-dependantmore » Protein Kinase A (PKA), whose activity is, in turn, regulated by the cAMP hydrolysis activity of phosphodiesterases, including PDE4. We propose that DISC1 acts as an assembly scaffold for all of these proteins and that the NDE1/NDEL1/LIS1/dynein complex is modulated by cAMP levels via PKA and PDE4.« less

Cortisol-induced immune suppression by a blockade of lymphocyte egress in traumatic brain injury.

PubMed

Dong, Tingting; Zhi, Liang; Bhayana, Brijesh; Wu, Mei X

2016-08-25

Acute traumatic brain injury (TBI) represents one of major causes of mortality and disability in the USA. Neuroinflammation has been regarded both beneficial and detrimental, probably in a time-dependent fashion. To address a role for neuroinflammation in brain injury, C57BL/6 mice were subjected to a closed head mild TBI (mTBI) by a standard controlled cortical impact, along with or without treatment of sphingosine 1-phosphate (S1P) or rolipram, after which the brain tissue of the impact site was evaluated for cell morphology via histology, inflammation by qRT-PCR and T cell staining, and cell death with Caspase-3 and TUNEL staining. Circulating lymphocytes were quantified by flow cytometry, and plasma hydrocortisone was analyzed by LC-MS/MS. To investigate the mechanism whereby cortisol lowered the number of peripheral T cells, T cell egress was tracked in lymph nodes by intravital confocal microscopy after hydrocortisone administration. We detected a decreased number of circulating lymphocytes, in particular, T cells soon after mTBI, which was inversely correlated with a transient and robust increase of plasma cortisol. The transient lymphocytopenia might be caused by cortisol in part via a blockade of lymphocyte egress as demonstrated by the ability of cortisol to inhibit T cell egress from the secondary lymphoid tissues. Moreover, exogenous hydrocortisone severely suppressed periphery lymphocytes in uninjured mice, whereas administering an egress-promoting agent S1P normalized circulating T cells in mTBI mice and increased T cells in the injured brain. Likewise, rolipram, a cAMP phosphodiesterase inhibitor, was also able to elevate cAMP levels in T cells in the presence of hydrocortisone in vitro and abrogate the action of cortisol in mTBI mice. The investigation demonstrated that the number of circulating T cells in the early phase of TBI was positively correlated with T cell infiltration and inflammatory responses as well as cell death at the cerebral cortex

4D MEMRI atlas of neonatal FVB/N mouse brain development.

PubMed

Szulc, Kamila U; Lerch, Jason P; Nieman, Brian J; Bartelle, Benjamin B; Friedel, Miriam; Suero-Abreu, Giselle A; Watson, Charles; Joyner, Alexandra L; Turnbull, Daniel H

2015-09-01

The widespread use of the mouse as a model system to study brain development has created the need for noninvasive neuroimaging methods that can be applied to early postnatal mice. The goal of this study was to optimize in vivo three- (3D) and four-dimensional (4D) manganese (Mn)-enhanced MRI (MEMRI) approaches for acquiring and analyzing data from the developing mouse brain. The combination of custom, stage-dependent holders and self-gated (motion-correcting) 3D MRI sequences enabled the acquisition of high-resolution (100-μm isotropic), motion artifact-free brain images with a high level of contrast due to Mn-enhancement of numerous brain regions and nuclei. We acquired high-quality longitudinal brain images from two groups of FVB/N strain mice, six mice per group, each mouse imaged on alternate odd or even days (6 3D MEMRI images at each day) covering the developmental stages between postnatal days 1 to 11. The effects of Mn-exposure, anesthesia and MRI were assessed, showing small but significant transient effects on body weight and brain volume, which recovered with time and did not result in significant morphological differences when compared to controls. Metrics derived from deformation-based morphometry (DBM) were used for quantitative analysis of changes in volume and position of a number of brain regions. The cerebellum, a brain region undergoing significant changes in size and patterning at early postnatal stages, was analyzed in detail to demonstrate the spatiotemporal characterization made possible by this new atlas of mouse brain development. These results show that MEMRI is a powerful tool for quantitative analysis of mouse brain development, with great potential for in vivo phenotype analysis in mouse models of neurodevelopmental diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

Depletion of tyrosyl DNA phosphodiesterase 2 activity enhances etoposide-mediated double-strand break formation and cell killing.

PubMed

Kont, Yasemin Saygideger; Dutta, Arijit; Mallisetty, Apurva; Mathew, Jeena; Minas, Tsion; Kraus, Christina; Dhopeshwarkar, Priyanka; Kallakury, Bhaskar; Mitra, Sankar; Üren, Aykut; Adhikari, Sanjay

2016-07-01

DNA topoisomerase 2 (Top2) poisons, including common anticancer drugs etoposide and doxorubicin kill cancer cells by stabilizing covalent Top2-tyrosyl-DNA 5'-phosphodiester adducts and DNA double-strand breaks (DSBs). Proteolytic degradation of the covalently attached Top2 leaves a 5'-tyrosylated blocked termini which is removed by tyrosyl DNA phosphodiesterase 2 (TDP2), prior to DSB repair through non-homologous end joining (NHEJ). Thus, TDP2 confers resistance of tumor cells to Top2-poisons by repairing such covalent DNA-protein adducts, and its pharmacological inhibition could enhance the efficacy of Top2-poisons. We discovered NSC111041, a selective inhibitor of TDP2, by optimizing a high throughput screening (HTS) assay for TDP2's 5'-tyrosyl phosphodiesterase activity and subsequent validation studies. We found that NSC111041 inhibits TDP2's binding to DNA without getting intercalated into DNA and enhanced etoposide's cytotoxicity synergistically in TDP2-expressing cells but not in TDP2 depleted cells. Furthermore, NSC111041 enhanced formation of etoposide-induced γ-H2AX foci presumably by affecting DSB repair. Immuno-histochemical analysis showed higher TDP2 expression in a sub-set of different type of tumor tissues. These findings underscore the feasibility of clinical use of suitable TDP2 inhibitors in adjuvant therapy with Top2-poisons for a sub-set of cancer patients with high TDP2 expression. Copyright © 2016 Elsevier B.V. All rights reserved.

4-dimensional functional profiling in the convulsant-treated larval zebrafish brain.

PubMed

Winter, Matthew J; Windell, Dylan; Metz, Jeremy; Matthews, Peter; Pinion, Joe; Brown, Jonathan T; Hetheridge, Malcolm J; Ball, Jonathan S; Owen, Stewart F; Redfern, Will S; Moger, Julian; Randall, Andrew D; Tyler, Charles R

2017-07-26

Functional neuroimaging, using genetically-encoded Ca 2+ sensors in larval zebrafish, offers a powerful combination of high spatiotemporal resolution and higher vertebrate relevance for quantitative neuropharmacological profiling. Here we use zebrafish larvae with pan-neuronal expression of GCaMP6s, combined with light sheet microscopy and a novel image processing pipeline, for the 4D profiling of chemoconvulsant action in multiple brain regions. In untreated larvae, regions associated with autonomic functionality, sensory processing and stress-responsiveness, consistently exhibited elevated spontaneous activity. The application of drugs targeting different convulsant mechanisms (4-Aminopyridine, Pentylenetetrazole, Pilocarpine and Strychnine) resulted in distinct spatiotemporal patterns of activity. These activity patterns showed some interesting parallels with what is known of the distribution of their respective molecular targets, but crucially also revealed system-wide neural circuit responses to stimulation or suppression. Drug concentration-response curves of neural activity were identified in a number of anatomically-defined zebrafish brain regions, and in vivo larval electrophysiology, also conducted in 4dpf larvae, provided additional measures of neural activity. Our quantification of network-wide chemoconvulsant drug activity in the whole zebrafish brain illustrates the power of this approach for neuropharmacological profiling in applications ranging from accelerating studies of drug safety and efficacy, to identifying pharmacologically-altered networks in zebrafish models of human neurological disorders.

Toxicology of 2,4-dichlorophenoxyacetic acid (2,4-D) and its determination in serum and brain tissue using gas chromatography-electron-capture detection.

PubMed

Oliveira, G H; Palermo-Neto, J

1995-01-01

A gas-liquid chromatographic method with an electron-capture detector was applied for 2,4-dichlorophenoxyacetic acid (2,4-D) determination in the serum and brain tissue of rats acutely intoxicated with the dimethylamine salt of 2,4-D. After extraction with ethyl ether, 2,4-D derivatization was performed using 2-chloroethanol and BCI3. The average recovery values found for serum and brain tissue were 98.5 +/- 4.8 and 93.3 +/- 7.5, respectively. The sensitivity limit of the method was 250 ng/mL for serum and 300 ng/g for brain tissue. The toxic effects of 2,4-D in rats were observed within one-half hour after its oral administration. Results suggest that the toxic mechanism of 2,4-D is related to an action on the central nervous system.

The search for mutations in the gene for the beta subunit of the cGMP phosphodiesterase (PDEB) in patients with autosomal recessive retinitis pigmentosa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riess, O.; Weber, B.; Hayden, M.R.

1992-10-01

The finding of a mutation in the beta subunit of the cyclic GMP (cGMP) phosphodiesterase gene causing retinal degeneration in mice (the Pdeb gene) prompted a search for disease-causing mutations in the human phosphodiesterase gene (PDEB gene) in patients with retinitis pigmentosa. All 22 exons including 196 bp of the 5[prime] region of the PDEB gene have been assessed for mutations by using single-strand conformational polymorphism analysis in 14 patients from 13 unrelated families with autosomal recessive retinitis pigmentosa (ARRP). No disease-causing mutations were found in this group of affected individuals of seven different ancestries. However, a frequent intronic andmore » two exonic polymorphisms (Leu[sup 489][yields]Gln and Gly[sup 842][yields]Gly) were identified. Segregation analysis using these polymorphic sites excludes linkage of ARRP to the PDEB gene in a family with two affected children. 43 refs., 3 figs., 2 tabs.« less

RESPITE: switching to riociguat in pulmonary arterial hypertension patients with inadequate response to phosphodiesterase-5 inhibitors.

PubMed

Hoeper, Marius M; Simonneau, Gérald; Corris, Paul A; Ghofrani, Hossein-Ardeschir; Klinger, James R; Langleben, David; Naeije, Robert; Jansa, Pavel; Rosenkranz, Stephan; Scelsi, Laura; Grünig, Ekkehard; Vizza, Carmine Dario; Chang, MiKyung; Colorado, Pablo; Meier, Christian; Busse, Dennis; Benza, Raymond L

2017-09-01

A proportion of pulmonary arterial hypertension (PAH) patients do not reach treatment goals with phosphodiesterase-5 inhibitors (PDE5i). RESPITE investigated the safety, feasibility and benefit of switching from PDE5i to riociguat in these patients.RESPITE was a 24-week, open-label, multicentre, uncontrolled study. Patients in World Health Organization (WHO) functional class (FC) III, with 6-min walking distance (6MWD) 165-440 m, cardiac index <3.0 L·min -1 ·m -2 and pulmonary vascular resistance >400 dyn·s·cm -5 underwent a 1-3 day PDE5i treatment-free period before receiving riociguat adjusted up to 2.5 mg maximum t.i.d Exploratory end-points included change in 6MWD, WHO FC, N -terminal prohormone of brain natriuretic peptide (NT-proBNP) and safety.Of 61 patients enrolled, 51 (84%) completed RESPITE. 50 (82%) were receiving concomitant endothelin receptor antagonists. At week 24, mean±sd 6MWD had increased by 31±63 m, NT-proBNP decreased by 347±1235 pg·mL -1 and WHO FC improved in 28 patients (54%). 32 patients (52%) experienced study drug-related adverse events and 10 (16%) experienced serious adverse events (2 (3%) study drug-related, none during the PDE5i treatment-free period). Six patients (10%) experienced clinical worsening, including death in two (not study drug-related).In conclusion, selected patients with PAH may benefit from switching from PDE5i to riociguat, but this strategy needs to be further studied. Copyright ©ERS 2017.

Behavioral and neurochemical characterization of mice deficient in the phosphodiesterase-1B (PDE1B) enzyme.

PubMed

Siuciak, J A; McCarthy, S A; Chapin, D S; Reed, T M; Vorhees, C V; Repaske, D R

2007-07-01

PDE1B is a calcium-dependent cyclic nucleotide phosphodiesterase that is highly expressed in the striatum. In order to investigate the physiological role of PDE1B in the central nervous system, PDE1B knockout mice (C57BL/6N background) were assessed in behavioral tests and their brains were assayed for monoamine content. In a variety of well-characterized behavioral tasks, including the elevated plus maze (anxiety-like behavior), forced swim test (depression-like behavior), hot plate (nociception) and two cognition models (passive avoidance and acquisition of conditioned avoidance responding), PDE1B knockout mice performed similarly to wild-type mice. PDE1B knockout mice showed increased baseline exploratory activity when compared to wild-type mice. When challenged with amphetamine (AMPH) and methamphetamine (METH), male and female PDE1B knockout mice showed an exaggerated locomotor response. Male PDE1B knockout mice also showed increased locomotor responses to higher doses of phencyclidine (PCP) and MK-801; however, this effect was not consistently observed in female knockout mice. In the striatum, increased dopamine turnover (DOPAC/DA and HVA/DA ratios) was found in both male and female PDE1B knockout mice. Striatal serotonin (5-HT) levels were also decreased in PDE1B knockout mice, although levels of the metabolite, 5HIAA, were unchanged. The present studies demonstrate increased striatal dopamine turnover in PDE1B knockout mice associated with increased baseline motor activity and an exaggerated locomotor response to dopaminergic stimulants such as methamphetamine and amphetamine. These data further support a role for PDE1B in striatal function.

Investigation into the role of phosphodiesterase IV in bronchorelaxation, including studies with human bronchus.

PubMed Central

Cortijo, J.; Bou, J.; Beleta, J.; Cardelús, I.; Llenas, J.; Morcillo, E.; Gristwood, R. W.

1993-01-01

1. We have investigated the role of cyclic nucleotide phosphodiesterase IV (PDE IV) in the relaxation of human bronchus and guinea-pig trachea in vitro and in guinea-pigs in vivo. 2. Functional studies showed that the selective PDE IV inhibitors, rolipram and denbufylline, relaxed human and guinea-pig preparations in vitro. 3. Two clinically used xanthine non-selective PDE inhibitors, theophylline and pentoxifylline, were also effective in these preparations, but were much less potent than the selective agents used. 4. The rank order of potency for the four PDE inhibitors in both species was similar. 5. Biochemical studies indicated that PDE IV was the major PDE isoform present in the human bronchial tissue. PDEs I, II and V were also identified. 6. Theophylline and pentoxifylline were, as expected, non-selective inhibitors of the human enzymes, but there was a good correlation between PDE IV inhibitory and bronchorelaxation potencies, suggesting that PDE IV inhibition is important for the clinical bronchodilator activities of the two xanthine compounds. 7. We have confirmed the ability of selective PDE IV inhibitors to cause bronchodilatation in guinea-pigs in vivo. 8. We conclude that our study has provided further evidence that selective PDE IV inhibitors could act as bronchodilators in the clinic. PMID:8383567

Histone deacetylation during brain development is essential for permanent masculinization of sexual behavior.

PubMed

Matsuda, Ken Ichi; Mori, Hiroko; Nugent, Bridget M; Pfaff, Donald W; McCarthy, Margaret M; Kawata, Mitsuhiro

2011-07-01

Epigenetic histone modifications are emerging as important mechanisms for conveyance of and maintenance of effects of the hormonal milieu to the developing brain. We hypothesized that alteration of histone acetylation status early in development by sex steroid hormones is important for sexual differentiation of the brain. It was found that during the critical period for sexual differentiation, histones associated with promoters of essential genes in masculinization of the brain (estrogen receptor α and aromatase) in the medial preoptic area, an area necessary for male sexual behavior, were differentially acetylated between the sexes. Consistent with these findings, binding of histone deacetylase (HDAC) 2 and 4 to the promoters was higher in males than in females. To examine the involvement of histone deacetylation on masculinization of the brain at the behavioral level, we inhibited HDAC in vivo by intracerebroventricular infusion of the HDAC inhibitor trichostatin A or antisense oligodeoxynucleotide directed against the mRNA for HDAC2 and -4 in newborn male rats. Aspects of male sexual behavior in adulthood were significantly reduced by administration of either trichostatin A or antisense oligodeoxynucleotide. These results demonstrate that HDAC activity during the early postnatal period plays a crucial role in the masculinization of the brain via modifications of histone acetylation status.

Engineered stabilization and structural analysis of the autoinhibited conformation of PDE4

DOE PAGES

Cedervall, Peder; Aulabaugh, Ann; Geoghegan, Kieran F.; ...

2015-03-09

Phosphodiesterase 4 (PDE4) is an essential contributor to intracellular signaling and an important drug target. The four members of this enzyme family (PDE4A to -D) are functional dimers in which each subunit contains two upstream conserved regions (UCR), UCR1 and -2, which precede the C-terminal catalytic domain. Alternative promoters, transcriptional start sites, and mRNA splicing lead to the existence of over 25 variants of PDE4, broadly classified as long, short, and supershort forms. We report the X-ray crystal structure of long form PDE4B containing UCR1, UCR2, and the catalytic domain, crystallized as a dimer in which a disulfide bond cross-linksmore » cysteines engineered into UCR2 and the catalytic domain. Biochemical and mass spectrometric analyses showed that the UCR2-catalytic domain interaction occurs in trans, and established that this interaction regulates the catalytic activity of PDE4. By elucidating the key structural determinants of dimerization, we show that only long forms of PDE4 can be regulated by this mechanism. The results also provide a structural basis for the long-standing observation of high- and low-affinity binding sites for the prototypic inhibitor rolipram.« less

Identification of cytosolic phosphodiesterases in the erythrocyte: A possible role for PDE5

PubMed Central

Adderley, Shaquria P.; Thuet, Kelly M.; Sridharan, Meera; Bowles, Elizabeth A.; Stephenson, Alan H.; Ellsworth, Mary L.; Sprague, Randy S.

2011-01-01

Summary Background Within erythrocytes (RBCs), cAMP levels are regulated by phosphodiesterases (PDEs). Increases in cAMP and ATP release associated with activation of β-adrenergic receptors (βARs) and prostacyclin receptors (IPRs) are regulated by PDEs 2, 4 and PDE 3, respectively. Here we establish the presence of cytosolic PDEs in RBCs and determine a role for PDE5 in regulating levels of cGMP. Material/Methods Purified cytosolic proteins were obtained from isolated human RBCs and western analysis was performed using antibodies against PDEs 3A, 4 and 5. Rabbit RBCs were incubated with dbcGMP, a cGMP analog, to determine the effect of cGMP on cAMP levels. To determine if cGMP affects receptor-mediated increases in cAMP, rabbit RBCs were incubated with dbcGMP prior to addition of isoproterenol (ISO), a βAR receptor agonist. To demonstrate that endogenous cGMP produces the same effect, rabbit and human RBCs were incubated with SpNONOate (SpNO), a nitric oxide donor, and YC1, a direct activator of soluble guanylyl cyclase (sGC), in the absence and presence of a selective PDE5 inhibitor, zaprinast (ZAP). Results Western analysis identified PDEs 3A, 4D and 5A. dbcGMP produced a concentration dependent increase in cAMP and ISO-induced increases in cAMP were potentiated by dbcGMP. In addition, incubation with YC1 and SpNO in the presence of ZAP potentiated βAR-induced increases in cAMP. Conclusions PDEs 2, 3A and 5 are present in the cytosol of human RBCs. PDE5 activity in RBCs regulates cGMP levels. Increases in intracellular cGMP augment cAMP levels. These studies suggest a novel role for PDE5 in erythrocytes. PMID:21525805

Methylation of the TERT promoter and risk stratification of childhood brain tumours: an integrative genomic and molecular study.

PubMed

Castelo-Branco, Pedro; Choufani, Sanaa; Mack, Stephen; Gallagher, Denis; Zhang, Cindy; Lipman, Tatiana; Zhukova, Nataliya; Walker, Erin J; Martin, Dianna; Merino, Diana; Wasserman, Jonathan D; Elizabeth, Cynthia; Alon, Noa; Zhang, Libo; Hovestadt, Volker; Kool, Marcel; Jones, David T W; Zadeh, Gelareh; Croul, Sidney; Hawkins, Cynthia; Hitzler, Johann; Wang, Jean C Y; Baruchel, Sylvain; Dirks, Peter B; Malkin, David; Pfister, Stefan; Taylor, Michael D; Weksberg, Rosanna; Tabori, Uri

2013-05-01

Identification of robust biomarkers of malignancy and methods to establish disease progression is a major goal in paediatric neuro-oncology. We investigated whether methylation of the TERT promoter can be a biomarker for malignancy and patient outcome in paediatric brain tumours. For the discovery cohort, we used samples obtained from patients with paediatric brain tumours and individuals with normal brain tissues stored at the German Cancer Research Center (Heidelberg, Germany). We used methylation arrays for genome-wide assessment of DNA. For the validation cohort, we used samples obtained from several tissues for which full clinical and follow-up data were available from two hospitals in Toronto (ON, Canada). We did methylation analysis using quantitative Sequenom and pyrosequencing of an identified region of the TERT promoter. We assessed TERT expression by real-time PCR. To establish whether the biomarker could be used to assess and predict progression, we analysed methylation in paired samples of tumours that transformed from low to high grade and from localised to metastatic, and in choroid plexus tumours of different grades. Finally, we investigated overall survival in patients with posterior fossa ependymomas in which the identified region was hypermethylated or not. All individuals responsible for assays were masked to the outcome of the patients. Analysis of 280 samples in the discovery cohort identified one CpG site (cg11625005) in which 78 (99%) of 79 samples from normal brain tissues and low-grade tumours were not hypermethylated, but 145 (72%) of 201 samples from malignant tumours were hypermethylated (>15% methylated; p<0.0001). Analysis of 68 samples in the validation cohort identified a subset of five CpG sites (henceforth, upstream of the transcription start site [UTSS]) that was hypermethylated in all malignant paediatric brain tumours that expressed TERT but not in normal tissues that did not express TERT (p<0.0001). UTSS had a positive

Efficacy of a novel phosphodiesterase inhibitor, E6005, in patients with atopic dermatitis: An investigator-blinded, vehicle-controlled study.

PubMed

Ohba, Fuminori; Matsuki, Shunji; Imayama, Shuhei; Matsuguma, Kyoko; Hojo, Seiichiro; Nomoto, Maiko; Akama, Hideto

2016-10-01

Phosphodiesterase type 4 (PDE4) inhibition is a well-known anti-inflammatory mechanism. However, the clinical use of PDE4 inhibitors has been compromised by the occurrence of mechanism-associated adverse reactions, which often limit the maximum tolerated dose. To minimize systemic exposure, a topically active PDE4 inhibitor with low transdermal bioavailability could be clinically useful. The purpose of this study was to evaluate the efficacy of a novel topical PDE4 inhibitor, E6005, in patients with atopic dermatitis. This randomized, investigator-blinded, vehicle-controlled, multiple ascending dose study included 40 adult male patients with atopic dermatitis, who were randomly assigned to 10 days of treatment with either E6005 ointment (0.01, 0.03, 0.1 or 0.2%) or vehicle ointment. Of 81 patients screened, 40 who had typical lesions on their posterior trunk were randomized into the study. One patient receiving 0.03% E6005 treatment discontinued because of acute gout and one receiving vehicle treatment discontinued because of progression of atopic dermatitis. The targeted lesion severity scores decreased in a concentration-dependent manner in patients treated with E6005. This drop was significant in the 0.2% E6005 ointment treatment group (mean percent change: -54.30%, p = 0.007). E6005 ointment showed anti-inflammatory efficacy in adult patients with atopic dermatitis.

Healthy Aging Promotion through Neuroscientific Information-Based Strategies.

PubMed

Seinfeld, Sofia; Sanchez-Vives, Maria V

2015-09-28

To ensure the well-being of a rapidly growing elderly population, it is fundamental to find strategies to foster healthy brain aging. With this intention, we designed a program of scientific-based lectures aimed at dissemination by established neuroscientists about brain function, brain plasticity and how lifestyle influences the brain. We also carried out a pilot study on the impact of the lectures on attendees. The objective was to provide information to elderly people in order to encourage them to identify unhealthy and healthy daily habits, and more importantly, to promote behavioral changes towards healthy brain aging. Here we report on our experience. In order to determine the impact of the lectures in the daily routine of the attendees, we asked them to fill out questionnaires. Preliminary results indicate that neuroscientific information-based strategies can be a useful method to have a positive impact on the lives of elderly, increase their awareness on how to improve brain function and promote positive lifestyle modifications. Furthermore, based on self-reported data, we also found that through this strategy it is possible to promote behavioral changes related to nutrition, sleep, and realization of physical and cognitively stimulating activities. Finally, based on the results obtained, the importance of promoting self-efficacy and the empowerment of the older populations is highlighted.

Healthy Aging Promotion through Neuroscientific Information-Based Strategies

PubMed Central

Seinfeld, Sofia; Sanchez-Vives, Maria V.

2015-01-01

To ensure the well-being of a rapidly growing elderly population, it is fundamental to find strategies to foster healthy brain aging. With this intention, we designed a program of scientific-based lectures aimed at dissemination by established neuroscientists about brain function, brain plasticity and how lifestyle influences the brain. We also carried out a pilot study on the impact of the lectures on attendees. The objective was to provide information to elderly people in order to encourage them to identify unhealthy and healthy daily habits, and more importantly, to promote behavioral changes towards healthy brain aging. Here we report on our experience. In order to determine the impact of the lectures in the daily routine of the attendees, we asked them to fill out questionnaires. Preliminary results indicate that neuroscientific information-based strategies can be a useful method to have a positive impact on the lives of elderly, increase their awareness on how to improve brain function and promote positive lifestyle modifications. Furthermore, based on self-reported data, we also found that through this strategy it is possible to promote behavioral changes related to nutrition, sleep, and realization of physical and cognitively stimulating activities. Finally, based on the results obtained, the importance of promoting self-efficacy and the empowerment of the older populations is highlighted. PMID:26426029

Surface-promoted hydrolysis of 2,4,6-trinitrotoluene and 2,4-dinitroanisole on pyrogenic carbonaceous matter.

PubMed

Ding, Kai; Byrnes, Cory; Bridge, Jarrod; Grannas, Amanda; Xu, Wenqing

2018-04-01

This study investigates the fate of sorbed nitroaromatics on the surface of pyrogenic carbonaceous matter (PCM) to assess the feasibility of a PCM-promoted hydrolysis. The degradation of two nitroaromatic compounds, 2,4,6-trinitrotoluene (TNT) and 2,4-dinitroanisole, was observed at pH 7 in the presence of graphite powder, a model PCM. By contrast, no decay occurred without graphite. Using TNT as a model compound, our results suggest that TNT decay demonstrated a strong pH dependence, with no reaction at pH 3-5 but rapid degradation at pH 6-10. Moreover, by fitting TNT decay at different pH conditions along with its sorption kinetics to the Langmuir Kinetic Model, our results suggest that the base-catalyzed hydrolysis was important. The activation energy for TNT decay was obtained by measuring reaction rates at different temperatures with or without graphite and no significant difference was observed. However, the addition of tetramethylammonium cation was able to promote TNT decay possibly due to its ability to attract more OH - from the aqueous solution, leading to an increase in the sorbed OH - concentrations. Nitrite and a Meisenheimer complex were identified as degradation products for TNT. Other PCM, such as biochar, also demonstrated a comparable ability in promoting TNT decay at pH 7. Furthermore, a rapid degradation of TNT at pH 7 was observed when biochar was used as a soil amendment (4% by weight). Our results suggest that PCM can facilitate TNT and 2,4-dinitroanisole decay via a surface-promoted hydrolysis at neutral pH conditions, suggesting a promising alternative for in situ soil remediation. Copyright © 2018 Elsevier Ltd. All rights reserved.

4H Leukodystrophy: A Brain Magnetic Resonance Imaging Scoring System.

PubMed

Vrij-van den Bos, Suzanne; Hol, Janna A; La Piana, Roberta; Harting, Inga; Vanderver, Adeline; Barkhof, Frederik; Cayami, Ferdy; van Wieringen, Wessel N; Pouwels, Petra J W; van der Knaap, Marjo S; Bernard, Geneviève; Wolf, Nicole I

2017-06-01

4H (hypomyelination, hypodontia and hypogonadotropic hypogonadism) leukodystrophy (4H) is an autosomal recessive hypomyelinating white matter (WM) disorder with neurologic, dental, and endocrine abnormalities. The aim of this study was to develop and validate a magnetic resonance imaging (MRI) scoring system for 4H. A scoring system (0-54) was developed to quantify hypomyelination and atrophy of different brain regions. Pons diameter and bicaudate ratio were included as measures of cerebral and brainstem atrophy, and reference values were determined using controls. Five independent raters completed the scoring system in 40 brain MRI scans collected from 36 patients with genetically proven 4H. Interrater reliability (IRR) and correlations between MRI scores, age, gross motor function, gender, and mutated gene were assessed. IRR for total MRI severity was found to be excellent (intraclass correlation coefficient: 0.87; 95% confidence interval: 0.80-0.92) but varied between different items with some (e.g., myelination of the cerebellar WM) showing poor IRR. Atrophy increased with age in contrast to hypomyelination scores. MRI scores (global, hypomyelination, and atrophy scores) significantly correlated with clinical handicap ( p  < 0.01 for all three items) and differed between the different genotypes. Our 4H MRI scoring system reliably quantifies hypomyelination and atrophy in patients with 4H, and MRI scores reflect clinical disease severity. Georg Thieme Verlag KG Stuttgart · New York.

The shopping brain: math anxiety modulates brain responses to buying decisions.

PubMed

Jones, William J; Childers, Terry L; Jiang, Yang

2012-01-01

Metacognitive theories propose that consumers track fluency feelings when buying, which may have biological underpinnings. We explored this using event-related potential (ERP) measures as twenty high-math anxiety (High MA) and nineteen low-math anxiety (Low MA) consumers made buying decisions for promoted (e.g., 15% discount) and non-promoted products. When evaluating prices, ERP correlates of higher perceptual and conceptual fluency were associated with buys, however only for High MA females under no promotions. In contrast, High MA females and Low MA males demonstrated greater FN400 amplitude, associated with enhanced conceptual processing, to prices of buys relative to non-buys under promotions. Concurrent late positive component (LPC) differences under no promotions suggest discrepant retrieval processes during price evaluations between consumer groups. When making decisions to buy or not, larger (smaller) P3, sensitive to outcome responses in the brain, was associated with buying for High MA females (Low MA females) under promotions, an effect also present for males under no promotions. Thus, P3 indexed decisions to buy differently between anxiety groups, but only for promoted items among females and for no promotions among males. Our findings indicate that perceptual and conceptual processes interact with anxiety and gender to modulate brain responses during consumer choices. Copyright © 2011 Elsevier B.V. All rights reserved.

Lgr4 promotes prostate tumorigenesis through the Jmjd2a/AR signaling pathway.

PubMed

Zhang, Jianwei; Li, Qi; Zhang, Shaojin; Xu, Quanquan; Wang, Tianen

2016-11-15

Lgr4 (leucine-rich repeat domain containing G protein-coupled receptor 4) is implicated in the transcriptional regulation of multiple histone demethylases in the progression of diverse cancers, but there are few reports concerning the molecular mechanism by which Lgr4 regulates histone demethylase activation in prostate cancer (PCa) progression. As Jmjd2a is a histone demethylase, in the current study, we investigated the relationship between interaction Lgr4 with Jmjd 2a and Jmjd2a/androgen receptor (AR) signaling pathway in PCa progression. Firstly, Lgr4 was overexpressed by transfecting pcDNA3.1(+)/Lgr4 plasmids into PCa (LNCaP and PC-3) cell lines. Next, we found that Lgr4 overexpression promoted Jmjd2a mRNA expression, reduced cell apoptosis and arrested cell cycle in the S phase, these effects were reversed by Jmjd2a silencing. Moreover, Lgr4 overexpression markedly elevated AR levels and its interaction with Jmjd2a, which was tested by co-immunoprecipitation and luciferase reporter assays. Furthermore, interaction AR with PSA promoter (containing an AR response element) was obviously improved by Lgr4 overexpression, and PSA silencing reduced Lgr4-induced cell apoptosis and cell cycle arrest in PCa cells. Taken together, Lgr4 may be a novel tumor marker providing new mechanistic insights into PCa progression. Lgr4 activates Jmjd2a/AR signaling pathway to promote interaction AR with PSA promoter, causing reduction of PCa apoptosis and cell cycle arrest. Copyright © 2016 Elsevier Inc. All rights reserved.

Brain-Derived Neurotrophic Factor Promotes Vasculature-Associated Migration of Neuronal Precursors toward the Ischemic Striatum

PubMed Central

Grade, Sofia; Weng, Yuan C.; Snapyan, Marina; Kriz, Jasna; Malva, João O.; Saghatelyan, Armen

2013-01-01

Stroke induces the recruitment of neuronal precursors from the subventricular zone (SVZ) into the ischemic striatum. In injured areas, de-routed neuroblasts use blood vessels as a physical scaffold to their migration, in a process that resembles the constitutive migration seen in the rostral migratory stream (RMS). The molecular mechanism underlying injury-induced vasculature-mediated migration of neuroblasts in the post-stroke striatum remains, however, elusive. Using adult mice we now demonstrate that endothelial cells in the ischemic striatum produce brain-derived neurotrophic factor (BDNF), a neurotrophin that promotes the vasculature-mediated migration of neuronal precursors in the RMS, and that recruited neuroblasts maintain expression of p75NTR, a low-affinity receptor for BDNF. Reactive astrocytes, which are widespread throughout the damaged area, ensheath blood vessels and express TrkB, a high-affinity receptor for BDNF. Despite the absence of BDNF mRNA, we observed strong BDNF immunolabeling in astrocytes, suggesting that these glial cells trap extracellular BDNF. Importantly, this pattern of expression is reminiscent of the adult RMS, where TrkB-expressing astrocytes bind and sequester vasculature-derived BDNF, leading to the entry of migrating cells into the stationary phase. Real-time imaging of cell migration in acute brain slices revealed a direct role for BDNF in promoting the migration of neuroblasts to ischemic areas. We also demonstrated that cells migrating in the ischemic striatum display higher exploratory behavior and longer stationary periods than cells migrating in the RMS. Our findings suggest that the mechanisms involved in the injury-induced vasculature-mediated migration of neuroblasts recapitulate, at least partially, those observed during constitutive migration in the RMS. PMID:23383048

In vivo1H NMR spectroscopy of the human brain at 9.4 T: Initial results

NASA Astrophysics Data System (ADS)

Deelchand, Dinesh Kumar; Moortele, Pierre-François Van de; Adriany, Gregor; Iltis, Isabelle; Andersen, Peter; Strupp, John P.; Thomas Vaughan, J.; Uğurbil, Kâmil; Henry, Pierre-Gilles

2010-09-01

In vivo proton NMR spectroscopy allows non-invasive detection and quantification of a wide range of biochemical compounds in the brain. Higher field strength is generally considered advantageous for spectroscopy due to increased signal-to-noise and increased spectral dispersion. So far 1H NMR spectra have been reported in the human brain up to 7 T. In this study we show that excellent quality short echo time STEAM and LASER 1H NMR spectra can be measured in the human brain at 9.4 T. The information content of the human brain spectra appears very similar to that measured in the past decade in rodent brains at the same field strength, in spite of broader linewidth in human brain. Compared to lower fields, the T1 relaxation times of metabolites were slightly longer while T2 relaxation values of metabolites were shorter (<100 ms) at 9.4 T. The linewidth of the total creatine (tCr) resonance at 3.03 ppm increased linearly with magnetic field (1.35 Hz/T from 1.5 T to 9.4 T), with a minimum achievable tCr linewidth of around 12.5 Hz at 9.4 T. At very high field, B0 microsusceptibility effects are the main contributor to the minimum achievable linewidth.

Ethanol-induced hyponatremia augments brain edema after traumatic brain injury.

PubMed

Katada, Ryuichi; Watanabe, Satoshi; Ishizaka, Atsushi; Mizuo, Keisuke; Okazaki, Shunichiro; Matsumoto, Hiroshi

2012-04-01

Alcohol consumption augments brain edema by expression of brain aquaporin-4 after traumatic brain injury. However, how ethanol induces brain aquaporin-4 expression remains unclear. Aquaporin-4 can operate with some of ion channels and transporters. Therefore, we hypothesized that ethanol may affect electrolytes through regulating ion channels, leading to express aquaporin-4. To clarify the hypothesis, we examined role of AQP4 expression in ethanol-induced brain edema and changes of electrolyte levels after traumatic brain injury in the rat. In the rat traumatic brain injury model, ethanol administration reduced sodium ion concentration in blood significantly 24 hr after injury. An aquaporin-4 inhibitor recovered sodium ion concentration in blood to normal. We observed low sodium ion concentration in blood and the increase of brain aquaporin-4 in cadaver with traumatic brain injury. Therefore, ethanol increases brain edema by the increase of aquaporin-4 expression with hyponatremia after traumatic brain injury.

MiR-32 promotes gastric carcinoma tumorigenesis by targeting Kruppel-like factor 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Chao; Yu, Jianchun, E-mail: yu_jchpumch@163.com; Liu, Yuqin

Gastric cancer (GC) is a prevalent malignant cancer worldwide and is highly lethal because of its fast growth. Currently, the clinical therapy options for GC remain limited. MiR-32 has been reported as an oncogenic microRNA in many cancers, but its role in GC is unclear. Here, we found that miR-32 was overexpressed in GC tissues compared with adjacent normal tissue, and miR-32 was higher in GC patients' plasma compared with healthy individuals. Furthermore, we have identified miR-32 to be oncogenic, by promoting gastric cell proliferation, migration and invasion. We also identified Kruppel-like factor 4 (KLF4) as a direct target ofmore » miR-32. Knockdown of KLF4 promoted proliferation, migration and invasion of GC cells. We conclude that miR-32 promotes GC cell proliferation, migration and invasion by targeting KLF4, suggesting that the miR-32-KLF4 pathway may be useful in clinical diagnosis and therapeutics. - Highlights: • miR-32 was overexpression in GC tissues than adjacent normal tissue. • miR-32 was higher in GC patients' plasma compared with healthy people. • miR-32 promotes GC cell proliferation, migration and invasion by targeting KLF4.« less

Antipsychotic drugs attenuate aberrant DNA methylation of DTNBP1 (dysbindin) promoter in saliva and post-mortem brain of patients with schizophrenia and Psychotic bipolar disorder.

PubMed

Abdolmaleky, Hamid M; Pajouhanfar, Sara; Faghankhani, Masoomeh; Joghataei, Mohammad Taghi; Mostafavi, Ashraf; Thiagalingam, Sam

2015-12-01

Due to the lack of genetic association between individual genes and schizophrenia (SCZ) pathogenesis, the current consensus is to consider both genetic and epigenetic alterations. Here, we report the examination of DNA methylation status of DTNBP1 promoter region, one of the most credible candidate genes affected in SCZ, assayed in saliva and post-mortem brain samples. The Illumina DNA methylation profiling and bisulfite sequencing of representative samples were used to identify methylation status of the DTNBP1 promoter region. Quantitative methylation specific PCR (qMSP) was employed to assess methylation of DTNBP1 promoter CpGs flanking a SP1 binding site in the saliva of SCZ patients, their first-degree relatives and control subjects (30, 15, and 30/group, respectively) as well as in post-mortem brains of patients with SCZ and bipolar disorder (BD) versus controls (35/group). qRT-PCR was used to assess DTNBP1 expression. We found DNA hypermethylation of DTNBP1 promoter in the saliva of SCZ patients (∼12.5%, P = 0.036), particularly in drug-naïve patients (∼20%, P = 0.011), and a trend toward hypermethylation in their first-degree relatives (P = 0.085) versus controls. Analysis of post-mortem brain samples revealed an inverse correlation between DTNBP1 methylation and expression, and normalization of this epigenetic change by classic antipsychotic drugs. Additionally, BD patients with psychotic depression exhibited higher degree of methylation versus other BD patients (∼80%, P = 0.025). DTNBP1 promoter DNA methylation may become a key element in a panel of biomarkers for diagnosis, prevention, or therapy in SCZ and at risk individuals pending confirmatory studies with larger sample sizes to attain a higher degree of significance. © 2015 Wiley Periodicals, Inc.

Human apolipoprotein E ɛ4 expression impairs cerebral vascularization and blood–brain barrier function in mice

PubMed Central

Alata, Wael; Ye, Yue; St-Amour, Isabelle; Vandal, Milène; Calon, Frédéric

2015-01-01

Human apolipoprotein E (APOE) exists in three isoforms ɛ2, ɛ3, and ɛ4, of which APOE4 is the main genetic risk factor of Alzheimer's disease (AD). As cerebrovascular defects are associated with AD, we tested whether APOE genotype has an impact on the integrity and function of the blood–brain barrier (BBB) in human APOE-targeted replacement mice. Using the quantitative in situ brain perfusion technique, we first found lower (13.0% and 17.0%) brain transport coefficient (Clup) of [3H]-diazepam in APOE4 mice at 4 and 12 months, compared with APOE2 and APOE3 mice, reflecting a decrease in cerebral vascularization. Accordingly, results from immunohistofluorescence experiments revealed a structurally reduced cerebral vascularization (26% and 38%) and thinner basement membranes (30% and 35%) in 12-month-old APOE4 mice compared with APOE2 and APOE3 mice, suggesting vascular atrophy. In addition, APOE4 mice displayed a 29% reduction in [3H]-d-glucose transport through the BBB compared with APOE2 mice without significant changes in the expression of its transporter GLUT1 in brain capillaries. However, an increase of 41.3% of receptor for advanced glycation end products (RAGE) was found in brain capillaries of 12-month-old APOE4 mice. In conclusion, profound divergences were observed between APOE genotypes at the cerebrovascular interface, suggesting that APOE4-induced BBB anomalies may contribute to AD development. PMID:25335802

cAMP Catalyzing Phosphodiesterases Control Cholinergic Muscular Activity But Their Inhibition Does Not Enhance 5-HT4 Receptor-Mediated Facilitation of Cholinergic Contractions in the Murine Gastrointestinal Tract

PubMed Central

Pauwelyn, Vicky; Lefebvre, Romain A.

2018-01-01

Background: As the signal transduction of 5-HT4 receptors on cholinergic neurons innervating smooth muscle is controlled by phosphodiesterase (PDE) 4 in porcine stomach and colon, and human large intestine, the in vivo gastroprokinetic effects of a 5-HT4 receptor agonist might be enhanced by combination with a selective PDE4 inhibitor. The presence of 5-HT4 receptors on cholinergic neurons towards murine gastrointestinal circular muscle was recently shown. If the control of this receptor pathway by PDE4 is also present in mice, this might be a good model for in vivo testing of the combination therapy. Therefore this study investigates the role of cAMP catalyzing PDEs in smooth muscle cell activity and in the intraneuronal signal transduction of the 5-HT4 receptors in the gastrointestinal tract of C57Bl/6J mice. Methods: In circular smooth muscle strips from murine fundus, jejunum, and colon, submaximal cholinergic contractions were induced by either electrical field stimulation (EFS) or by carbachol (muscarinic receptor agonist). The influence of the PDE inhibitors IBMX (non-selective), vinpocetine (PDE1), EHNA (PDE2), cilostamide (PDE3), and rolipram (PDE4) was tested on these contractions and on the facilitating effect of a submaximal concentration of prucalopride (5-HT4 receptor agonist) on EFS-induced contractions. Results: In the three gastrointestinal regions, IBMX and cilostamide concentration-dependently decreased carbachol- as well as EFS-induced contractions. Some inhibitory effect was also observed with rolipram. In the fundus a non-significant trend for an enhancement of the facilitating effect of prucalopride on EFS-induced contractions was observed with IBMX, but none of the selective PDE inhibitors enhanced the facilitating effect of prucalopride in fundus, jejunum or colon. Conclusion: In analogy with the porcine gastrointestinal tract, in murine fundus, jejunum, and colon circular smooth muscle PDE3 is the main regulator of the cAMP turnover, with

Test of the 'glymphatic' hypothesis demonstrates diffusive and aquaporin-4-independent solute transport in rodent brain parenchyma.

PubMed

Smith, Alex J; Yao, Xiaoming; Dix, James A; Jin, Byung-Ju; Verkman, Alan S

2017-08-21

Transport of solutes through brain involves diffusion and convection. The importance of convective flow in the subarachnoid and paravascular spaces has long been recognized; a recently proposed 'glymphatic' clearance mechanism additionally suggests that aquaporin-4 (AQP4) water channels facilitate convective transport through brain parenchyma. Here, the major experimental underpinnings of the glymphatic mechanism were re-examined by measurements of solute movement in mouse brain following intracisternal or intraparenchymal solute injection. We found that: (i) transport of fluorescent dextrans in brain parenchyma depended on dextran size in a manner consistent with diffusive rather than convective transport; (ii) transport of dextrans in the parenchymal extracellular space, measured by 2-photon fluorescence recovery after photobleaching, was not affected just after cardiorespiratory arrest; and (iii) Aqp4 gene deletion did not impair transport of fluorescent solutes from sub-arachnoid space to brain in mice or rats. Our results do not support the proposed glymphatic mechanism of convective solute transport in brain parenchyma.

Test of the 'glymphatic' hypothesis demonstrates diffusive and aquaporin-4-independent solute transport in rodent brain parenchyma

PubMed Central

Yao, Xiaoming; Dix, James A; Jin, Byung-Ju

2017-01-01

Transport of solutes through brain involves diffusion and convection. The importance of convective flow in the subarachnoid and paravascular spaces has long been recognized; a recently proposed ‘glymphatic’ clearance mechanism additionally suggests that aquaporin-4 (AQP4) water channels facilitate convective transport through brain parenchyma. Here, the major experimental underpinnings of the glymphatic mechanism were re-examined by measurements of solute movement in mouse brain following intracisternal or intraparenchymal solute injection. We found that: (i) transport of fluorescent dextrans in brain parenchyma depended on dextran size in a manner consistent with diffusive rather than convective transport; (ii) transport of dextrans in the parenchymal extracellular space, measured by 2-photon fluorescence recovery after photobleaching, was not affected just after cardiorespiratory arrest; and (iii) Aqp4 gene deletion did not impair transport of fluorescent solutes from sub-arachnoid space to brain in mice or rats. Our results do not support the proposed glymphatic mechanism of convective solute transport in brain parenchyma. PMID:28826498

The prostaglandin E2 E-prostanoid 4 receptor exerts anti-inflammatory effects in brain innate immunity.

PubMed

Shi, Ju; Johansson, Jenny; Woodling, Nathaniel S; Wang, Qian; Montine, Thomas J; Andreasson, Katrin

2010-06-15

Peripheral inflammation leads to immune responses in brain characterized by microglial activation, elaboration of proinflammatory cytokines and reactive oxygen species, and secondary neuronal injury. The inducible cyclooxygenase (COX), COX-2, mediates a significant component of this response in brain via downstream proinflammatory PG signaling. In this study, we investigated the function of the PGE2 E-prostanoid (EP) 4 receptor in the CNS innate immune response to the bacterial endotoxin LPS. We report that PGE2 EP4 signaling mediates an anti-inflammatory effect in brain by blocking LPS-induced proinflammatory gene expression in mice. This was associated in cultured murine microglial cells with decreased Akt and I-kappaB kinase phosphorylation and decreased nuclear translocation of p65 and p50 NF-kappaB subunits. In vivo, conditional deletion of EP4 in macrophages and microglia increased lipid peroxidation and proinflammatory gene expression in brain and in isolated adult microglia following peripheral LPS administration. Conversely, EP4 selective agonist decreased LPS-induced proinflammatory gene expression in hippocampus and in isolated adult microglia. In plasma, EP4 agonist significantly reduced levels of proinflammatory cytokines and chemokines, indicating that peripheral EP4 activation protects the brain from systemic inflammation. The innate immune response is an important component of disease progression in a number of neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. In addition, recent studies demonstrated adverse vascular effects with chronic administration of COX-2 inhibitors, indicating that specific PG signaling pathways may be protective in vascular function. This study supports an analogous and beneficial effect of PGE2 EP4 receptor signaling in suppressing brain inflammation.

Localization of HIV-1 co-receptors CCR5 and CXCR4 in the brain of children with AIDS.

PubMed Central

Vallat, A. V.; De Girolami, U.; He, J.; Mhashilkar, A.; Marasco, W.; Shi, B.; Gray, F.; Bell, J.; Keohane, C.; Smith, T. W.; Gabuzda, D.

1998-01-01

The chemokine receptors CCR5 and CXCR4 are co-receptors together with CD4 for human immunodeficiency virus (HIV)-1 entry into target cells. Macrophage-tropic HIV-1 viruses use CCR5 as a co-receptor, whereas T-cell-line tropic viruses use CXCR4. HIV-1 infects the brain and causes a progressive encephalopathy in 20 to 30% of infected children and adults. Most of the HIV-1-infected cells in the brain are macrophages and microglia. We examined expression of CCR5 and CXCR4 in brain tissue from 20 pediatric acquired immune deficiency syndrome (AIDS) patients in relation to neuropathological consequences of HIV-1 infection. The overall frequency of CCR5-positive perivascular mononuclear cells and macrophages was increased in the brains of children with severe HIV-1 encephalitis (HIVE) compared with children with mild HIVE or non-AIDS controls, whereas the frequency of CXCR4-positive perivascular cells did not correlate with disease severity. CCR5- and CXCR4-positive macrophages and microglia were detected in inflammatory lesions in the brain of children with severe HIVE. In addition, CXCR4 was detected in a subpopulation of neurons in autopsy brain tissue and primary human brain cultures. Similar findings were demonstrated in the brain of adult AIDS patients and controls. These findings suggest that CCR5-positive mononuclear cells, macrophages, and microglia contribute to disease progression in the central nervous system of children and adults with AIDS by serving as targets for virus replication. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 8 PMID:9422534

Dopamine receptor D4 promoter hypermethylation increases the risk of drug addiction.

PubMed

Ji, Huihui; Xu, Xuting; Liu, Guili; Liu, Huifen; Wang, Qinwen; Shen, Wenwen; Li, Longhui; Xie, Xiaohu; Hu, Haochang; Xu, Lei; Zhou, Wenhua; Duan, Shiwei

2018-02-01

Heroin and methylamphetamine (METH) are two addictive drugs that cause serious problems for society. Dopamine receptor D4 (DRD4), a key receptor in the dopaminergic system, may facilitate the development of drug addiction. The aim of the present study was to investigate the association between the promoter methylation level of DRD4 gene and drug addiction. Bisulfite pyrosequencing technology was used to measure the methylation levels of DRD4 promoter in 60 drug addicts and 52 matched controls. Significantly higher levels of DRD4 CpG1 and CpG4 methylation were detected in METH and heroin drug addicts compared with controls (P<0.05). Male METH addicts exhibited significantly higher DRD4 CpG1, CpG2 and CpG4 methylation levels compared with sex-matched controls (P<0.05). In heroin addicts, a positive correlation was observed between depression-dejection and DRD4 CpG5 methylation (r=0.537, P=0.039) whereas there was a negative correlation between drug usage frequency and CpG1 methylation (r=-0.632, P=0.011). In METH addicts, methylation levels were not significantly associated with depression-dejection and drug usage frequency. In addition, luciferase assays demonstrated that the target sequence of the DRD4 promoter upregulates gene expression. The results of the present study suggest that DNA methylation of DRD4 may be responsible for the pathophysiology of drug addiction.

Neuregulin 1 Deficiency Modulates Adolescent Stress-Induced Dendritic Spine Loss in a Brain Region-Specific Manner and Increases Complement 4 Expression in the Hippocampus.

PubMed

Clarke, David J; Chohan, Tariq W; Kassem, Mustafa S; Smith, Kristie L; Chesworth, Rose; Karl, Tim; Kuligowski, Michael P; Fok, Sandra Y; Bennett, Maxwell R; Arnold, Jonathon C

2018-03-16

One neuropathological feature of schizophrenia is a diminished number of dendritic spines in the prefrontal cortex and hippocampus. The neuregulin 1 (Nrg1) system is involved in the plasticity of dendritic spines, and chronic stress decreases dendritic spine densities in the prefrontal cortex and hippocampus. Here, we aimed to assess whether Nrg1 deficiency confers vulnerability to the effects of adolescent stress on dendritic spine plasticity. We also assessed other schizophrenia-relevant neurobiological changes such as microglial cell activation, loss of parvalbumin (PV) interneurons, and induction of complement factor 4 (C4). Adolescent male wild-type (WT) and Nrg1 heterozygous mice were subjected to chronic restraint stress before their brains underwent Golgi impregnation or immunofluorescent staining of PV interneurons, microglial cells, and C4. Stress in WT mice promoted dendritic spine loss and microglial cell activation in the prefrontal cortex and the hippocampus. However, Nrg1 deficiency rendered mice resilient to stress-induced dendritic spine loss in the infralimbic cortex and the CA3 region of the hippocampus without affecting stress-induced microglial cell activation in these brain regions. Nrg1 deficiency and adolescent stress combined to trigger increased dendritic spine densities in the prelimbic cortex. In the hippocampal CA1 region, Nrg1 deficiency accentuated stress-induced dendritic spine loss. Nrg1 deficiency increased C4 protein and decreased C4 mRNA expression in the hippocampus, and the number of PV interneurons in the basolateral amygdala. This study demonstrates that Nrg1 modulates the impact of stress on the adolescent brain in a region-specific manner. It also provides first evidence of a link between Nrg1 and C4 systems in the hippocampus.

Superresolution Imaging of Aquaporin-4 Cluster Size in Antibody-Stained Paraffin Brain Sections

PubMed Central

Smith, Alex J.; Verkman, Alan S.

2015-01-01

The water channel aquaporin-4 (AQP4) forms supramolecular clusters whose size is determined by the ratio of M1- and M23-AQP4 isoforms. In cultured astrocytes, differences in the subcellular localization and macromolecular interactions of small and large AQP4 clusters results in distinct physiological roles for M1- and M23-AQP4. Here, we developed quantitative superresolution optical imaging methodology to measure AQP4 cluster size in antibody-stained paraffin sections of mouse cerebral cortex and spinal cord, human postmortem brain, and glioma biopsy specimens. This methodology was used to demonstrate that large AQP4 clusters are formed in AQP4−/− astrocytes transfected with only M23-AQP4, but not in those expressing only M1-AQP4, both in vitro and in vivo. Native AQP4 in mouse cortex, where both isoforms are expressed, was enriched in astrocyte foot-processes adjacent to microcapillaries; clusters in perivascular regions of the cortex were larger than in parenchymal regions, demonstrating size-dependent subcellular segregation of AQP4 clusters. Two-color superresolution imaging demonstrated colocalization of Kir4.1 with AQP4 clusters in perivascular areas but not in parenchyma. Surprisingly, the subcellular distribution of AQP4 clusters was different between gray and white matter astrocytes in spinal cord, demonstrating regional specificity in cluster polarization. Changes in AQP4 subcellular distribution are associated with several neurological diseases and we demonstrate that AQP4 clustering was preserved in a postmortem human cortical brain tissue specimen, but that AQP4 was not substantially clustered in a human glioblastoma specimen despite high-level expression. Our results demonstrate the utility of superresolution optical imaging for measuring the size of AQP4 supramolecular clusters in paraffin sections of brain tissue and support AQP4 cluster size as a primary determinant of its subcellular distribution. PMID:26682810

Neuraminidases 3 and 4 regulate neuronal function by catabolizing brain gangliosides.

PubMed

Pan, Xuefang; De Aragão, Camila De Britto Pará; Velasco-Martin, Juan P; Priestman, David A; Wu, Harry Y; Takahashi, Kohta; Yamaguchi, Kazunori; Sturiale, Luisella; Garozzo, Domenico; Platt, Frances M; Lamarche-Vane, Nathalie; Morales, Carlos R; Miyagi, Taeko; Pshezhetsky, Alexey V

2017-08-01

Gangliosides (sialylated glycolipids) play an essential role in the CNS by regulating recognition and signaling in neurons. Metabolic blocks in processing and catabolism of gangliosides result in the development of severe neurologic disorders, including gangliosidoses manifesting with neurodegeneration and neuroinflammation. We demonstrate that 2 mammalian enzymes, neuraminidases 3 and 4, play important roles in catabolic processing of brain gangliosides by cleaving terminal sialic acid residues in their glycan chains. In neuraminidase 3 and 4 double-knockout mice, G M3 ganglioside is stored in microglia, vascular pericytes, and neurons, causing micro- and astrogliosis, neuroinflammation, accumulation of lipofuscin bodies, and memory loss, whereas their cortical and hippocampal neurons have lower rate of neuritogenesis in vitro Double-knockout mice also have reduced levels of G M1 ganglioside and myelin in neuronal axons. Furthermore, neuraminidase 3 deficiency drastically increased storage of G M2 in the brain tissues of an asymptomatic mouse model of Tay-Sachs disease, a severe human gangliosidosis, indicating that this enzyme is responsible for the metabolic bypass of β-hexosaminidase A deficiency. Together, our results provide the first in vivo evidence that neuraminidases 3 and 4 have important roles in CNS function by catabolizing gangliosides and preventing their storage in lipofuscin bodies.-Pan, X., De Britto Pará De Aragão, C., Velasco-Martin, J. P., Priestman, D. A., Wu, H. Y., Takahashi, K., Yamaguchi, K., Sturiale, L., Garozzo, D., Platt, F. M., Lamarche-Vane, N., Morales, C. R., Miyagi, T., Pshezhetsky, A. V. Neuraminidases 3 and 4 regulate neuronal function by catabolizing brain gangliosides. © FASEB.

Interferon-γ from Brain Leukocytes Enhances Meningitis by Type 4 Streptococcus pneumoniae

PubMed Central

Pettini, Elena; Fiorino, Fabio; Cuppone, Anna Maria; Iannelli, Francesco; Medaglini, Donata; Pozzi, Gianni

2015-01-01

Streptococcus pneumoniae is the leading cause of bacterial meningitis. Pneumococcal meningitis is a life-threatening disease with high rates of mortality and neurological sequelae. Immune targeting of S. pneumoniae is essential for clearance of infection; however, within the brain, the induced inflammatory response contributes to pathogenesis. In this study we investigate the local inflammatory response and the role of IFN-γ in a murine model of pneumococcal meningitis induced by intracranial injection of type 4 S. pneumoniae. Lymphoid and myeloid cell populations involved in meningitis, as well as cytokine gene expression, were investigated after infection. Animals were treated with a monoclonal antibody specific for murine IFN-γ to evaluate its role in animal survival. Intracranial inoculation of 3 × 104 colony-forming units of type 4 strain TIGR4 caused 75% of mice to develop meningitis within 4 days. The amount of lymphocytes, NK cells, neutrophils, monocytes and macrophages in the brain increased 48 h post infection. IFN-γ mRNA levels were about 240-fold higher in brains of infected mice compared to controls. Pro-inflammatory cytokines such as IL-1β and TNF-α, and TLR2 were also upregulated. In vivo treatment with anti-IFN-γ antibody increased survival of infected mice. This study shows that IFN-γ produced during meningitis by type 4 S. pneumoniae enhances bacterial pathogenesis exerting a negative effect on the disease outcome. PMID:26648922

Serpins Promote Cancer Cell Survival and Vascular Cooption in Brain Metastasis

PubMed Central

Valiente, Manuel; Obenauf, Anna C.; Jin, Xin; Chen, Qing; Zhang, Xiang H.-F.; Lee, Derek J.; Chaft, Jamie E.; Kris, Mark G.; Huse, Jason T.; Brogi, Edi; Massagué, Joan

2014-01-01

Brain metastasis is an ominous complication of cancer, yet most cancer cells that infiltrate the brain die of unknown causes. Here we identify plasmin from the reactive brain stroma as a defense against metastatic invasion, and plasminogen activator (PA) inhibitory serpins in cancer cells as a shield against this defense. Plasmin suppresses brain metastasis in two ways: by converting membrane-bound astrocytic FasL into a paracrine death signal for cancer cells, and by inactivating the axon pathfinding molecule L1CAM that metastatic cells express for spreading along brain capillaries and for metastatic outgrowth. Brain metastatic cells from lung cancer and breast cancer express high levels of anti-PA serpins, including neuroserpin and serpin B2, to prevent plasmin generation and its deleterious consequences. By protecting cancer cells from death signals and fostering vascular cooption, anti-PA serpins provide a unifying mechanism for the initiation of brain metastasis in lung and breast cancers. PMID:24581498