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1.
Phys Chem Chem Phys ; 24(35): 21406-21416, 2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36047336

RESUMO

Potentially prebiotic chemical reactions leading to RNA nucleotides involve periods of UV irradiation, which are necessary to promote selectivity and destroy biologially irrelevant side products. Nevertheless, UV light has only been applied to promote specific stages of prebiotic reactions and its effect on complete prebiotic reaction sequences has not been extensively studied. Here, we report on an experimental and computational investigation of the photostability of 2-thiooxazole (2-TO), a potential precursor of pyrimidine and 8-oxopurine nucleotides on early Earth. Our UV-irradiation experiments resulted in rapid decomposition of 2-TO into unidentified small molecule photoproducts. We further clarify the underlying photochemistry by means of accurate ab initio calculations and surface hopping molecular dynamics simulations. Overall, the computational results show efficient rupture of the aromatic ring upon the photoexcitation of 2-TO via breaking of the C-O bond. Consequently, the initial stage of the divergent prebiotic synthesis of pyrimidine and 8-oxopurine nucleotides would require periodic shielding from UV light either with sun screening chromophores or through a planetary scenario that would protect 2-TO until it is transformed into a more stable intermediate compound, e.g. oxazolidinone thione.


Assuntos
Nucleotídeos , RNA , Fotoquímica , Purinonas , Pirimidinas/química , RNA/química
2.
J Med Chem ; 65(5): 4030-4057, 2022 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-35175749

RESUMO

Pathogens such as Plasmodium and Trypanosoma spp. are unable to synthesize purine nucleobases. They rely on the salvage of these purines and their nucleosides from the host cell to synthesize the purine nucleotides required for DNA/RNA production. The key enzymes in this pathway are purine phosphoribosyltransferases (PRTs). Here, we synthesized 16 novel acyclic nucleoside phosphonates, 12 with a chiral center at C-2', and eight bearing a second chiral center at C-6'. Of these, bisphosphonate (S,S)-48 is the most potent inhibitor of the Plasmodium falciparum and P. vivax 6-oxopurine PRTs and the most potent inhibitor of two Trypanosoma brucei (Tbr) 6-oxopurine PRTs yet discovered, with Ki values as low as 2 nM. Crystal structures of (S,S)-48 in complex with human and Tbr 6-oxopurine PRTs show that the inhibitor binds to the enzymes in different conformations, providing an explanation for its potency and selectivity (i.e., 35-fold in favor of the parasite enzymes).


Assuntos
Antimaláricos , Organofosfonatos , Parasitos , Pentosiltransferases/metabolismo , Animais , Antimaláricos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Nucleosídeos/química , Nucleosídeos/farmacologia , Organofosfonatos/química , Organofosfonatos/farmacologia , Plasmodium falciparum , Purinonas
3.
Int J Mol Sci ; 23(2)2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-35054895

RESUMO

Toxoplasma gondii is unable to synthesize purines de novo, instead salvages them from its environment, inside the host cell, for which they need high affinity carriers. Here, we report the expression of a T. gondii Equilibrative Nucleoside Transporter, Tg244440, in a Trypanosoma brucei strain from which nucleobase transporters have been deleted. Tg244440 transported hypoxanthine and guanine with similar affinity (Km ~1 µM), while inosine and guanosine displayed Ki values of 4.05 and 3.30 µM, respectively. Low affinity was observed for adenosine, adenine, and pyrimidines, classifying Tg244440 as a high affinity oxopurine transporter. Purine analogues were used to probe the substrate-transporter binding interactions, culminating in quantitative models showing different binding modes for oxopurine bases, oxopurine nucleosides, and adenosine. Hypoxanthine and guanine interacted through protonated N1 and N9, and through unprotonated N3 and N7 of the purine ring, whereas inosine and guanosine mostly employed the ribose hydroxy groups for binding, in addition to N1H of the nucleobase. Conversely, the ribose moiety of adenosine barely made any contribution to binding. Tg244440 is the first gene identified to encode a high affinity oxopurine transporter in T. gondii and, to the best of our knowledge, the first purine transporter to employ different binding modes for nucleosides and nucleobases.


Assuntos
Proteínas de Transporte de Nucleosídeos/metabolismo , Nucleosídeos/metabolismo , Purinonas/metabolismo , Toxoplasma/fisiologia , Toxoplasmose/parasitologia , Fibroblastos , Técnicas de Silenciamento de Genes , Humanos , Proteínas de Transporte de Nucleosídeos/genética , Nucleosídeos/química , Filogenia , Ligação Proteica , Purinonas/química , Toxoplasma/classificação
4.
Arch Physiol Biochem ; 128(4): 945-950, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32207349

RESUMO

OBJECTIVE: This study investigated effects of zaprinast and avanafil on angiogenesis, vascular endothelial growth factor (VEGF), bone morphogenic protein (BMP) 2, 4 and 7. METHODS: Female rats were randomly divided into four groups (n = 6). Sham; abdomen was approximately 2 cm opened and closed. Ovariectomised (OVX); abdomen was opened 2 cm and the ovaries were cut. OVX + zaprinast and OVX + avanafil groups; after the same procedure with OVX, 10 mg/kg zaprinast and avanafil were orally administered for 2 month, respectively. Angiogenesis and the levels of VEGF, BMP2, 4 and 7 were determined. RESULTS: VEGF, BMP2, 4 and 7 levels in OVX + zaprinast and especially OVX + avanafil groups were higher than the sham and OVX (p < .05). However, only VEGF and BMP2 levels in OVX + zaprinast group were significant according to sham (p < .05). Also, angiogenesis in OVX + zaprinast and OVX + avanafil groups was dominant according to sham and OVX (p < .05). CONCLUSIONS: Zaprinast and avanafil induced BMP2, 4 and 7 levels synergistically with increased VEGF and angiogenesis in renal tissue.


Assuntos
Proteínas Morfogenéticas Ósseas , Rim , Neovascularização Fisiológica , Purinonas , Pirimidinas , Animais , Proteína Morfogenética Óssea 2 , Proteína Morfogenética Óssea 4 , Proteína Morfogenética Óssea 7 , Proteínas Morfogenéticas Ósseas/metabolismo , Feminino , Rim/metabolismo , Ovariectomia , Purinonas/farmacologia , Pirimidinas/farmacologia , Ratos , Fator A de Crescimento do Endotélio Vascular/metabolismo
5.
Neurotherapeutics ; 18(4): 2565-2578, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34697772

RESUMO

Dopamine replacement represents the standard therapy for Parkinson's disease (PD), a common, chronic, and incurable neurological disorder; however, this approach only treats the symptoms of this devastating disease. In the search for novel disease-modifying therapies that target other relevant molecular and cellular mechanisms, Drosophila has emerged as a valuable tool to study neurodegenerative diseases due to the presence of a complex central nervous system, the blood-brain barrier, and a similar neurotransmitter profile to humans. Human PD-related genes also display conservation in flies; DJ-1ß is the fly ortholog of DJ-1, a gene for which mutations prompt early-onset recessive PD. Interestingly, flies mutant for DJ-1ß exhibit PD-related phenotypes, including motor defects, high oxidative stress (OS) levels and metabolic alterations. To identify novel therapies for PD, we performed an in vivo high-throughput screening assay using DJ-1ß mutant flies and compounds from the Prestwick® chemical library. Drugs that improved motor performance in DJ-1ß mutant flies were validated in DJ-1-deficient human neural-like cells, revealing that zaprinast displayed the most significant ability to suppress OS-induced cell death. Zaprinast inhibits phosphodiesterases and activates GPR35, an orphan G-protein-coupled receptor not previously associated with PD. We found that zaprinast exerts its beneficial effect in both fly and human PD models through several disease-modifying mechanisms, including reduced OS levels, attenuated apoptosis, increased mitochondrial viability, and enhanced glycolysis. Therefore, our results support zaprinast as a potential therapeutic for PD in future clinical trials.


Assuntos
Doença de Parkinson , Animais , Drosophila/genética , Drosophila/metabolismo , Estresse Oxidativo , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Proteína Desglicase DJ-1/genética , Proteína Desglicase DJ-1/metabolismo , Purinonas/metabolismo , Purinonas/farmacologia , Purinonas/uso terapêutico
6.
Biochem Biophys Res Commun ; 556: 171-178, 2021 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-33839412

RESUMO

It is well known that osteoporosis is a significant chronic disease with the increase of the aging population. Here, we report that expression of G protein-coupled receptor 35 (GPR35) in bone marrow mesenchymal stem cells (BMSCs) is suppressed in diagnosed osteoporosis patients and osteoporotic mice. The expression of GPR35 on BMSCs is enhanced during osteogenic differentiation. GPR35 knockout suppresses the proliferation and osteogenesis of BMSCs and deteriorates bone mass in both sham-treated and ovariectomized mice. Moreover, GPR35 deficiency reduces ß-catenin activity in BMSCs. In contrast, the overexpression of GPR35 contributes to these processes in BMSCs. Finally, using zaprinast, a synthetic GPR35 agonist, we show that zaprinast rescues OVX-induced bone loss and promotes bone generation in mice. Thus, GPR35 may as a new target and its agonist zaprinast may serve as a novel treatment for osteoporosis.


Assuntos
Glicogênio Sintase Quinase 3 beta/metabolismo , Osteogênese , Receptores Acoplados a Proteínas G/metabolismo , Via de Sinalização Wnt , beta Catenina/metabolismo , Animais , Densidade Óssea/efeitos dos fármacos , Densidade Óssea/genética , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Proliferação de Células , Feminino , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Tamanho do Órgão/efeitos dos fármacos , Tamanho do Órgão/genética , Osteoporose Pós-Menopausa/tratamento farmacológico , Osteoporose Pós-Menopausa/prevenção & controle , Ovariectomia , Purinonas/farmacologia , Purinonas/uso terapêutico , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/deficiência , Receptores Acoplados a Proteínas G/genética
7.
Chem Commun (Camb) ; 56(2): 201-204, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31799554

RESUMO

Dark nπ* states were shown to have substantial contribution to the destructive photochemistry of pyrimidine nucleobases. Based on quantum-chemical calculations, we demonstrate that the characteristic hydrogen bonding pattern of the GC base pair could facilitate the formation of a wobble excited-state charge-transfer complex. This entails a barrierless electron-driven proton transfer (EDPT) process which enables damageless photodeactivation of the base pair. These photostabilizing properties are retained even when guanine is exchanged to hypoxanthine. The inaccessibility of this process in the AT base pair sheds further light on the reasons why cytosine is less susceptible to the formation of photodimers in double-stranded DNA.


Assuntos
Pareamento de Bases , DNA/química , Prótons , Pareamento de Bases/efeitos da radiação , DNA/genética , DNA/efeitos da radiação , Ligação de Hidrogênio , Modelos Químicos , Conformação de Ácido Nucleico , Purinonas/química , Pirimidinonas/química , Teoria Quântica , Raios Ultravioleta
8.
Brain Res Bull ; 153: 223-231, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31493542

RESUMO

Alzheimer's disease (AD), characterized by a progressive impairment of memory and cognition, is a major health problem in both developing and developed countries. Currently, no drugs can reverse the progression of AD. Phosphodiesterase 5 (PDE5) is a critical component of the cyclic guanosine monophosphate/protein kinase G (cGMP/PKG) signaling pathway in neurons, the inhibition of which has produced neuroprotective effects, and PDE5 inhibitors have recently been thought to be potential therapeutic agents for AD. In this paper, we summarized the outstanding progress that has been made in PDE5 inhibitors as anti-AD agents with encouraging results in animal studies, clinical trials and the investigations on the underlying mechanisms. The novel PDE5 inhibitors reported recently in the treatment of AD were also reviewed and discussed.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores da Fosfodiesterase 5/uso terapêutico , Animais , Cognição/efeitos dos fármacos , GMP Cíclico/metabolismo , Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5 , Flavonoides , Humanos , Neurônios/metabolismo , Fármacos Neuroprotetores/farmacologia , Inibidores da Fosfodiesterase 5/farmacologia , Purinonas , Pirimidinas , Transdução de Sinais/efeitos dos fármacos , Citrato de Sildenafila , Sulfonamidas , Tadalafila , Dicloridrato de Vardenafila
9.
Phys Chem Chem Phys ; 21(25): 13467-13473, 2019 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-31187825

RESUMO

This work scrutinizes the relaxation mechanism of 2-oxopurine. Contrary to its ancestor, purine, which is a UVC chromophore, 2-oxopurine shows a red-shifted absorption spectrum centered in the UVA region. In 2-oxopurine, relaxation along the ππ* spectroscopic state directs the population from the Franck-Condon (FC) region towards a minimum, which acts as a crossroad for the further decay of the system either to triplet states or, alternatively, to the ground state through a C6-puckered S1/S0 funnel. A comparison of the optical properties and excited state potential energy surfaces of purine, 2-oxopurine, 2-aminopurine, 6-oxopurine and adenine, allows establishing how the position and nature of substituent tune the photophysics of purine. For this series, we conclude that both C2 and C6 substitution redshift the absorption spectrum of purine, with 2-oxo substitution exhibiting the largest shift. An important exception is the canonical nucleobase adenine, which presents a blue shifted absorption spectrum. The topography of purine's ππ* potential energy surface experiences major changes when functionalized at the C6 position. In particular, the disappearance of the minimum along the ππ* potential energy surface efficiently funnels the excited state population from the FC region to the ground state and increases the photostability of 6-aminopurine (adenine) and 6-oxopurine (hypoxanthine) nucleobases.


Assuntos
Purinonas/química , 2-Aminopurina/química , Adenina/química , Modelos Moleculares , Estrutura Molecular , Processos Fotoquímicos , Teoria Quântica , Espectrofotometria , Termodinâmica , Raios Ultravioleta
10.
Bioorg Med Chem Lett ; 29(3): 481-486, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30554955

RESUMO

Phosphodiesterase 2 (PDE2) has received much attention for the potential treatment of the central nervous system (CNS) disorders. Herein, based on the existing PDE2 inhibitors and their binding modes, a series of purin-6-one derivatives were designed, synthesized and evaluated for PDE2 inhibitory activities, which led to the discovery of the best compounds 6p and 6s with significant inhibitory potency (IC50: 72 and 81 nM, respectively). Docking simulation was performed to insert compound 6s into the crystal structure of PDE2 at the active site to determine the binding mode. Furthermore, compound 6s significantly protected HT-22 cells against corticosterone-induced cytotoxicity and rescued corticosterone-induced decreases in cAMP and cGMP levels. It also produced anxiolytic-like effect in the elevated plus-maze test and exhibited favorable pharmacokinetic properties in vivo. These results might bring significant instruction for further development of potent PDE2 inhibitors.


Assuntos
Ansiolíticos/farmacologia , Nucleotídeo Cíclico Fosfodiesterase do Tipo 2/antagonistas & inibidores , Desenho de Fármacos , Fármacos Neuroprotetores/farmacologia , Inibidores de Fosfodiesterase/farmacologia , Purinonas/farmacologia , Animais , Ansiolíticos/síntese química , Ansiolíticos/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Nucleotídeo Cíclico Fosfodiesterase do Tipo 2/metabolismo , Relação Dose-Resposta a Droga , Humanos , Camundongos , Estrutura Molecular , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química , Inibidores de Fosfodiesterase/síntese química , Inibidores de Fosfodiesterase/química , Purinonas/síntese química , Purinonas/química , Relação Estrutura-Atividade
11.
Pharmacol Rep ; 71(1): 139-148, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30550994

RESUMO

BACKGROUND: The G protein-coupled receptor 35 (GPR35), is considered important for nociceptive transmission, as suggested by accumulating evidence. This receptor was discovered in 1998; however, a lack of pharmacological tools prevented a complete understanding of its function and how to exploit it therapeutically. We studied the influence of CXCL17, kynurenic acid and zaprinast on nociceptive transmission in naïve and neuropathic mice. Additionally, we investigated the influence of kynurenic acid and zaprinast on morphine effectiveness in neuropathic pain. METHODS: The chronic constriction injury (CCI) of the sciatic nerve in Swiss mice was performed. The CXCL17, kynurenic acid, zaprinast and morphine were injected intrathecally into naive and CCI-exposed mice at day 14. To evaluate tactile and thermal hypersensitivity, the von Frey and cold plate tests were used, respectively. RESULTS: Our results have shown, for the first time, that administration of CXCL17 in naïve mice induced strong pain-related behaviours, as measured by von Frey and cold plate tests. Moreover, we demonstrated that kynurenic acid and zaprinast diminished CXCL17-evoked pain-related behaviours in both tests. Kynurenic acid and zaprinast reduced thermal and tactile hypersensitivity developed by sciatic nerve injury and strongly enhanced the effectiveness of morphine in neuropathy. CONCLUSIONS: Our study highlights the importance of GPR35 as a receptor involved in neuropathic pain development. Therefore, these results suggest that the modulation of GPR35 could become a potential strategy for the treatment of neuropathic pain.


Assuntos
Analgésicos Opioides/farmacologia , Analgésicos/farmacologia , Comportamento Animal/efeitos dos fármacos , Quimiocinas CXC/toxicidade , Ácido Cinurênico/farmacologia , Morfina/farmacologia , Percepção da Dor/efeitos dos fármacos , Limiar da Dor/efeitos dos fármacos , Purinonas/farmacologia , Ciática/tratamento farmacológico , Medula Espinal/efeitos dos fármacos , Analgésicos/administração & dosagem , Analgésicos Opioides/administração & dosagem , Animais , Quimiocinas CXC/administração & dosagem , Modelos Animais de Doenças , Injeções Espinhais , Ácido Cinurênico/administração & dosagem , Masculino , Camundongos , Morfina/administração & dosagem , Purinonas/administração & dosagem , Receptores Acoplados a Proteínas G/efeitos dos fármacos , Receptores Acoplados a Proteínas G/metabolismo , Ciática/induzido quimicamente , Ciática/fisiopatologia , Ciática/psicologia , Medula Espinal/metabolismo , Medula Espinal/fisiopatologia
12.
Eur J Pharmacol ; 839: 21-32, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30213497

RESUMO

The mechanism of neuropathic pain is complex and unclear. Based on our results, we postulate that an intensification of the kynurenine pathway occurs as a consequence of nerve injury. The G protein-coupled receptor 35 (GPR35) is important for kynurenine pathway activation. Cyclic GMP-specific phosphodiesterase inhibitors have also been shown to have beneficial effects on neuropathic pain. Therefore, the aims of our research were to elucidate how a substance that acts as both an agonist of GPR35 and an inhibitor of phosphodiesterase influences neuropathic pain in a rat model. Here, we demonstrated that preemptive and repeated intrathecal (i.t.) administration (16 h and 1 h before injury and then after nerve ligation daily for 7 days) of zaprinast (1 µg/5 µl) significantly attenuated mechanical (von Frey test) and thermal (cold plate test) hypersensitivity measured on day 7 after chronic constriction injury, and the effect of even a single injection lasted up to 24 h. Our data indicate that zaprinast diminished the number of IBA1-positive cells and consequently attenuated the levels of IL-1beta, IL-6, IL-18, and NOS2 in the lumbar spinal cord and/or dorsal root ganglia. Our results also demonstrated that zaprinast potentiated the analgesic properties of morphine and buprenorphine. In summary, in a neuropathic pain model, zaprinast significantly reduced pain symptoms and enhanced the effectiveness of opioids. Our data provide new evidence that modulation of both GPR35 and phosphodiesterase could be an important strategy for innovative pharmacological treatments designed to decrease hypersensitivity evoked by nerve injury.


Assuntos
Analgésicos Opioides/farmacologia , Neuralgia/tratamento farmacológico , Purinonas/farmacologia , Animais , Buprenorfina/farmacologia , Proteínas de Ligação ao Cálcio/metabolismo , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Proteína Glial Fibrilar Ácida/metabolismo , Proteínas dos Microfilamentos/metabolismo , Morfina/farmacologia , Neuralgia/metabolismo , Neuralgia/patologia , Neuralgia/fisiopatologia , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Nociceptividade/efeitos dos fármacos , Purinonas/uso terapêutico , Ratos , Receptores Acoplados a Proteínas G/agonistas , Medula Espinal/efeitos dos fármacos , Medula Espinal/metabolismo
13.
Future Med Chem ; 10(17): 2029-2038, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30067076

RESUMO

AIM: DNA damage response plays an eminent role in patients' response to conventional chemotherapy and radiotherapy. Its inhibition is of great interest as it can overcome cancer cell resistance and reduce the effective doses of DNA damaging agents. Results & methodology: We have focused our research on phosphatidylinositol 3-kinase-related kinases and prepared 35 novel compounds through a scaffold hopping approach. The newly synthesized inhibitors were tested on a panel of nine cancer and one healthy cell lines alone and in combination with appropriate doses of doxorubicin. CONCLUSION: Five novel compounds 4f, 10b, 15g, 7e and 15f in combination with doxorubicin showed significant antiproliferative effect on seven cancer cell lines while not affecting the cell growth alone.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Purinonas/química , Purinonas/farmacologia , Pirimidinonas/química , Pirimidinonas/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Doxorrubicina/farmacologia , Humanos , Neoplasias/tratamento farmacológico , Pirróis/química , Pirróis/farmacologia
14.
Adv Exp Med Biol ; 1074: 511-517, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29721983

RESUMO

In humans cone photoreceptors are responsible for high-resolution colour vision. A variety of retinal diseases can compromise cone viability, and, at present, no satisfactory treatment options are available. Here, we present data towards establishing a reliable, high-throughput assay system that will facilitate the search for cone neuroprotective compounds using the murine-photoreceptor cell line 661 W. To further characterize 661 W cells, a retinal marker study was performed, followed by the induction of cell death using paradigms over-activating cGMP-dependent protein kinase G (PKG). We found that 661 W cells may be used to mimic specific aspects of cone degeneration and may thus be valuable for future compound screening studies.


Assuntos
Proteínas Quinases Dependentes de GMP Cíclico/fisiologia , Avaliação Pré-Clínica de Medicamentos/métodos , Proteínas do Olho/fisiologia , Ensaios de Triagem em Larga Escala , Fármacos Neuroprotetores/isolamento & purificação , Células Fotorreceptoras Retinianas Cones/enzimologia , Animais , Biomarcadores , Linhagem Celular Tumoral , GMP Cíclico/metabolismo , Proteínas Quinases Dependentes de GMP Cíclico/efeitos dos fármacos , Nucleotídeo Cíclico Fosfodiesterase do Tipo 6/deficiência , Ativação Enzimática/efeitos dos fármacos , Proteínas do Olho/análise , Camundongos , Camundongos Knockout , Fármacos Neuroprotetores/farmacologia , Especificidade de Órgãos , Inibidores de Fosfodiesterase/farmacologia , Purinonas/farmacologia , Células Fotorreceptoras Retinianas Cones/citologia
16.
Mol Brain ; 11(1): 12, 2018 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-29506545

RESUMO

The 18 kDa translocator protein (TSPO) is primarily localized in the outer mitochondrial membrane of steroid-synthesizing cells in the central and peripheral nervous systems. One of the protein's main functions is transporting substrate cholesterol into the mitochondria in a prerequisite process for steroid synthesis. Clinical trials have indicated that TSPO ligands might be valuable in treating some neuropathies and psychopathies. However, limited information is known about the role of TSPO in postpartum depression (PPD). The TSPO ligand ZBD-2, a derivative of XBD173, was synthesized in our laboratory. Behavioral tests, enzyme linked immunosorbent assay, and Western blot were employed to evaluate ZBD-2's efficacy against PPD and to elucidate the potential underlying molecular mechanism. The TSPO levels significantly decreased in the basolateral amygdala of PPD models. After treatment for 2 weeks, ZBD-2 alleviated depression-like behaviors and enhanced the TSPO level in a PPD animal model. The underlying mechanisms of ZBD-2 were related to regulate the hypothalamic-pituitary-adrenal axis, enhance 5-HT and BDNF secretion, and maintain the excitatory and inhibitory synaptic protein expression to normal levels. Our results directly confirm that ZBD-2 exerts a therapeutic effect on PPD, which provides a new target for anti-PPD drug development.


Assuntos
Acetamidas/uso terapêutico , Antidepressivos/uso terapêutico , Depressão Pós-Parto/tratamento farmacológico , Purinonas/uso terapêutico , Acetamidas/farmacologia , Animais , Antidepressivos/farmacologia , Ansiedade/complicações , Ansiedade/tratamento farmacológico , Complexo Nuclear Basolateral da Amígdala/efeitos dos fármacos , Complexo Nuclear Basolateral da Amígdala/metabolismo , Complexo Nuclear Basolateral da Amígdala/patologia , Complexo Nuclear Basolateral da Amígdala/fisiopatologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Depressão Pós-Parto/complicações , Depressão Pós-Parto/patologia , Depressão Pós-Parto/fisiopatologia , Modelos Animais de Doenças , Feminino , Hormônios/metabolismo , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipotálamo-Hipofisário/patologia , Ligantes , Camundongos Endogâmicos C57BL , Plasticidade Neuronal/efeitos dos fármacos , Purinonas/farmacologia , Receptores de GABA/metabolismo , Receptores de Glutamato/metabolismo , Receptores de Serotonina/metabolismo
17.
PLoS Negl Trop Dis ; 12(2): e0006301, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29481567

RESUMO

Due to toxicity and compliance issues and the emergence of resistance to current medications new drugs for the treatment of Human African Trypanosomiasis are needed. A potential approach to developing novel anti-trypanosomal drugs is by inhibition of the 6-oxopurine salvage pathways which synthesise the nucleoside monophosphates required for DNA/RNA production. This is in view of the fact that trypanosomes lack the machinery for de novo synthesis of the purine ring. To provide validation for this approach as a drug target, we have RNAi silenced the three 6-oxopurine phosphoribosyltransferase (PRTase) isoforms in the infectious stage of Trypanosoma brucei demonstrating that the combined activity of these enzymes is critical for the parasites' viability. Furthermore, we have determined crystal structures of two of these isoforms in complex with several acyclic nucleoside phosphonates (ANPs), a class of compound previously shown to inhibit 6-oxopurine PRTases from several species including Plasmodium falciparum. The most potent of these compounds have Ki values as low as 60 nM, and IC50 values in cell based assays as low as 4 µM. This data provides a solid platform for further investigations into the use of this pathway as a target for anti-trypanosomal drug discovery.


Assuntos
Inibidores Enzimáticos/farmacologia , Redes e Vias Metabólicas/efeitos dos fármacos , Purinonas/metabolismo , Tripanossomicidas/farmacologia , Trypanosoma brucei brucei/metabolismo , Domínio Catalítico , Descoberta de Drogas , Inibidores Enzimáticos/química , Humanos , Hipoxantina Fosforribosiltransferase/antagonistas & inibidores , Hipoxantina Fosforribosiltransferase/química , Hipoxantina Fosforribosiltransferase/genética , Hipoxantina Fosforribosiltransferase/metabolismo , Modelos Moleculares , Pentosiltransferases/antagonistas & inibidores , Pentosiltransferases/química , Pentosiltransferases/genética , Pentosiltransferases/metabolismo , Interferência de RNA , Tripanossomicidas/química , Trypanosoma brucei brucei/efeitos dos fármacos , Trypanosoma brucei brucei/enzimologia , Trypanosoma brucei brucei/genética
18.
Eur J Med Chem ; 146: 381-394, 2018 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-29407965

RESUMO

A novel butanehydrazide derivatives of purine-2,6-dione designed using a ligand-based approach were synthesized and their in vitro activity against both PDE4B and PDE7A isoenzymes was assessed. The 7,8-disubstituted purine-2,6-dione derivatives 31, 34, 37, and 40 appeared to be the most potent PDE4/7 inhibitors with IC50 values in the range of that of the reference rolipram and BRL-50481, respectively. Moreover, docking studies explained the importance of N-(2,3,4-trihydroxybenzylidene)butanehydrazide substituent in position 7 of purine-2,6-dione core for dual PDE4/7 inhibitory properties. The inhibition of both the cAMP-specific PDE isoenzymes resulted in a strong anti-TNF-α effect. Compounds 31, 34, and 37 in the in vivo study in rats with LPS-induced endotoxemia decreased the maximum concentration of this proinflammatory cytokine by 53, 84 and 88%, respectively.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Butanos/farmacologia , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 7/antagonistas & inibidores , Desenho de Fármacos , Hidrazinas/farmacologia , Inibidores de Fosfodiesterase/farmacologia , Purinonas/farmacologia , Animais , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/química , Butanos/análise , Butanos/síntese química , Butanos/química , Nucleotídeo Cíclico Fosfodiesterase do Tipo 7/metabolismo , Relação Dose-Resposta a Droga , Endotoxemia/tratamento farmacológico , Humanos , Hidrazinas/síntese química , Hidrazinas/química , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Masculino , Estrutura Molecular , Inibidores de Fosfodiesterase/síntese química , Inibidores de Fosfodiesterase/química , Purinonas/síntese química , Purinonas/química , Ratos , Ratos Wistar , Relação Estrutura-Atividade
19.
Am J Physiol Endocrinol Metab ; 313(3): E321-E334, 2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28679626

RESUMO

Bradykinin (BK) promotes insulin sensitivity and glucose uptake in adipocytes and other cell types. We demonstrated that in rat adipocytes BK enhances insulin-stimulated glucose transport via endothelial nitric oxide synthase, nitric oxide (NO) generation, and decreased activity of the mitogen-activated protein kinase (MAPK) JNK (c-Jun NH2-terminal kinase). In endothelial cells, NO increases soluble guanylate cyclase (sGC) activity, which, in turn, activates protein kinase G (PKG) by increasing cGMP levels. In this study, we investigated whether BK acts via the sGC-cGMP-PKG pathway to inhibit the negative effects of JNK on insulin signaling and glucose uptake in rat adipocytes. BK augmented cGMP concentrations. The BK-induced enhancement of insulin-stimulated glucose uptake was mimicked by the sGC activator YC-1 and a cell-permeable cGMP analog, CPT-cGMP, and inhibited by the sGC inhibitor ODQ and the PKG inhibitor KT 5823. Transfection of dominant-negative PKG reduced the BK augmentation of insulin-induced Akt phosphorylation. The activation of JNK and ERK1/2 by insulin was attenuated by BK, which was mediated by the sGC-cGMP-PKG pathway. Whereas insulin-stimulated phosphorylation of upstream activators of JNK and ERK, i.e., MKK4 and MEK1/2, was unaffected, BK augmented insulin-mediated induction of MKP-5 mRNA and protein levels. Furthermore, zaprinast, a phosphodiesterase inhibitor, enhanced cGMP and MKP-5 and prolonged the action of BK. These data indicate that BK enhances insulin action by inhibition of negative feedback by JNK and ERK via upregulation of MKP-5, mediated by the sGC-cGMP-PKG signaling pathway.


Assuntos
Adipócitos/efeitos dos fármacos , Bradicinina/farmacologia , Proteínas Quinases Dependentes de GMP Cíclico/efeitos dos fármacos , Fosfatases de Especificidade Dupla/efeitos dos fármacos , Resistência à Insulina , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Fosfatases da Proteína Quinase Ativada por Mitógeno/efeitos dos fármacos , RNA Mensageiro/efeitos dos fármacos , Adipócitos/metabolismo , Animais , Western Blotting , GMP Cíclico/metabolismo , Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , Fosfatases de Especificidade Dupla/genética , Fosfatases de Especificidade Dupla/metabolismo , Glucose/metabolismo , Guanilato Ciclase/efeitos dos fármacos , Guanilato Ciclase/metabolismo , Imunoprecipitação , Proteínas Quinases JNK Ativadas por Mitógeno/efeitos dos fármacos , Masculino , Fosfatases da Proteína Quinase Ativada por Mitógeno/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/efeitos dos fármacos , Óxido Nítrico Sintase Tipo III/metabolismo , Inibidores de Fosfodiesterase/farmacologia , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Purinonas/farmacologia , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais/efeitos dos fármacos
20.
Pharmacol Res ; 123: 27-39, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28648739

RESUMO

G protein-coupled receptor 35 (GPR35), a receptor for lysophosphatidic acid, is highly expressed in the gastrointestinal tract. Recently, GPR35 has been implicated in the onset of inflammatory bowel disease (IBD), but its role in physiological and pathological processes in the colon remains undefined. In this study, we investigated the contribution of GPR35-mediated signalling to mucosal repair of colonic epithelium in IBD. GPR35 function was examined in a wound healing model, using young adult mouse colon epithelium (YAMC) cells, and in a dextran sulphate sodium (DSS)-induced mouse model of colitis. Cell proliferation, mRNA expression, extracellular signal-regulated kinase (ERK) activation, and protein localization were determined by MTT assay, quantitative RT-PCR, western blotting, and immunohistochemistry, respectively. GPR35 agonists (YE120, zaprinast, and pamoic acid) promoted wound repair in a concentration-dependent manner independently of cell proliferation, whereas a specific GPR35 antagonist CID2745687, forskolin, and pertussis toxin reversed the YE120-induced effect. YE120 increased the mRNA expression of fibronectin and its receptor integrin α5, and ERK1/2 phosphorylation, but these responses were attenuated by CID2745687 and forskolin. Furthermore, the severity of DSS-induced colitis was significantly reduced by daily injections of pamoic acid via upregulation of fibronectin and integrin α5 in the colonic epithelium. GPR35 signalling promotes mucosal repair by inducing fibronectin and integrin α5 expression, coupling to Gi protein, and activating ERK1/2 in colonic epithelial cells. These findings define GPR35 as a candidate therapeutic target in IBD.


Assuntos
Movimento Celular/fisiologia , Colo/citologia , Células Epiteliais/fisiologia , Mucosa Intestinal/metabolismo , Receptores Acoplados a Proteínas G/agonistas , Cicatrização/fisiologia , Animais , Linhagem Celular , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/metabolismo , Colite/patologia , Colo/metabolismo , Colo/patologia , Citocinas/genética , Sulfato de Dextrana , Células Epiteliais/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fibronectinas/metabolismo , Furanos/farmacologia , Integrinas/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Naftóis/uso terapêutico , Nitrilas/farmacologia , Peroxidase/metabolismo , Purinonas/farmacologia , RNA Mensageiro/metabolismo , Ratos , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores Acoplados a Proteínas G/metabolismo
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