Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.951
Filtrar
1.
PLoS Negl Trop Dis ; 14(8): e0008575, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32866156

RESUMO

BACKGROUND: Treatment failure and resistance to the commonly used drugs remains a major obstacle for successful chemotherapy against visceral leishmaniasis (VL). Since the development of novel therapeutics involves exorbitant costs, the effectiveness of the currently available antitrypanosomatid drug suramin has been investigated as an antileishmanial, specifically for VL,in vitro and in animal model experiments. METHODOLOGY/PRINCIPAL: Leishmania donovani promastigotes were treated with suramin and studies were performed to determine the extent and mode of cell mortality, cell cycle arrest and other in vitro parameters. In addition, L. donovani infected BALB/c mice were administered suramin and a host of immunological parameters determined to estimate the antileishmanial potency of the drug. Finally, isothermal titration calorimetry (ITC) and enzymatic assays were used to probe the interaction of the drug with one of its putative targets namely parasitic phosphoglycerate kinase (LmPGK). FINDINGS: The in vitro studies revealed the potential efficacy of suramin against the Leishmania parasite. This observation was further substantiated in the in vivo murine model, which demonstrated that upon suramin administration, the Leishmania infected BALB/c mice were able to reduce the parasitic burden and also generate the host protective immunological responses. ITC and enzyme assays confirmed the binding and consequent inhibition of LmPGK due to the drug. CONCLUSIONS/SIGNIFICANCE: All experiments affirmed the efficacy of suramin against L. donovani infection, which could possibly lead to its inclusion in the repertoire of drugs against VL.


Assuntos
Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Leishmaniose Visceral/tratamento farmacológico , Suramina/farmacologia , Suramina/uso terapêutico , Animais , Apoptose/efeitos dos fármacos , Citocinas/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Concentração Inibidora 50 , Leishmania donovani/efeitos dos fármacos , Leishmaniose Visceral/parasitologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Óxido Nítrico/metabolismo , Fosfoglicerato Quinase/efeitos dos fármacos , Células RAW 264.7/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
2.
Artigo em Inglês | MEDLINE | ID: mdl-32513797

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic that originated in Wuhan, China, in December 2019 has impacted public health, society, the global economy, and the daily lives of billions of people in an unprecedented manner. There are currently no specific registered antiviral drugs to treat or prevent SARS-CoV-2 infections. Therefore, drug repurposing would be the fastest route to provide at least a temporary solution while better, more specific drugs are being developed. Here, we demonstrate that the antiparasitic drug suramin inhibits SARS-CoV-2 replication, protecting Vero E6 cells with a 50% effective concentration (EC50) of ∼20 µM, which is well below the maximum attainable level in human serum. Suramin also decreased the viral load by 2 to 3 logs when Vero E6 cells or cells of a human lung epithelial cell line (Calu-3 2B4 [referred to here as "Calu-3"]) were treated. Time-of-addition and plaque reduction assays performed on Vero E6 cells showed that suramin acts on early steps of the replication cycle, possibly preventing binding or entry of the virus. In a primary human airway epithelial cell culture model, suramin also inhibited the progression of infection. The results of our preclinical study warrant further investigation and suggest that it is worth evaluating whether suramin provides any benefit for COVID-19 patients, which obviously requires safety studies and well-designed, properly controlled randomized clinical trials.


Assuntos
Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Pneumonia Viral/tratamento farmacológico , Suramina/farmacologia , Replicação Viral/efeitos dos fármacos , Animais , Linhagem Celular , Chlorocebus aethiops , Avaliação Pré-Clínica de Medicamentos , Reposicionamento de Medicamentos , Humanos , Pandemias , Células Vero , Carga Viral/efeitos dos fármacos
3.
PLoS One ; 15(5): e0233089, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32459810

RESUMO

Many drugs are promiscuous and bind to multiple targets. On the one hand, these targets may be linked to unwanted side effects, but on the other, they may achieve a combined desired effect (polypharmacology) or represent multiple diseases (drug repositioning). With the growth of 3D structures of drug-target complexes, it is today possible to study drug promiscuity at the structural level and to screen vast amounts of drug-target interactions to predict side effects, polypharmacological potential, and repositioning opportunities. Here, we pursue such an approach to identify drugs inactivating B-cells, whose dysregulation can function as a driver of autoimmune diseases. Screening over 500 kinases, we identified 22 candidate targets, whose knock out impeded the activation of B-cells. Among these 22 is the gene KDR, whose gene product VEGFR2 is a prominent cancer target with anti-VEGFR2 drugs on the market for over a decade. The main result of this paper is that structure-based drug repositioning for the identified kinase targets identified the cancer drug ibrutinib as micromolar VEGFR2 inhibitor with a very high therapeutic index in B-cell inactivation. These findings prove that ibrutinib is not only acting on the Bruton's tyrosine kinase BTK, against which it was designed. Instead, it may be a polypharmacological drug, which additionally targets angiogenesis via inhibition of VEGFR2. Therefore ibrutinib carries potential to treat other VEGFR2 associated disease. Structure-based drug repositioning explains ibrutinib's anti VEGFR2 action through the conservation of a specific pattern of interactions of the drug with BTK and VEGFR2. Overall, structure-based drug repositioning was able to predict these findings at a fraction of the time and cost of a conventional screen.


Assuntos
Reposicionamento de Medicamentos/métodos , Pirazóis/química , Pirazóis/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Tirosina Quinase da Agamaglobulinemia/metabolismo , Linfócitos B/metabolismo , Humanos , Células Jurkat , Interferência de RNA , Transdução de Sinais/efeitos dos fármacos , Suramina/química , Suramina/farmacologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
4.
FEBS Lett ; 594(1): 94-103, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31359422

RESUMO

Extracellular levels of soluble TIMP-3 are low, reflecting its binding by extracellular matrix (ECM) components including sulfated glycosaminoglycans (SGAGs) and endocytosis via low density lipoprotein receptor-related protein 1. Since TIMP-3 inhibits ECM degradation, the ability of SGAGs to elevate extracellular TIMP-3 is significant for osteoarthritis treatment. Previous studies of such interactions have utilized immobilized TIMP-3 or ligands. Here, we report the thermodynamics of the interactions of the sGAG-binding N-domain of TIMP-3 with chondroitin sulfate, pentosan polysulfate, and suramin in solution using isothermal titration calorimetry. All three interactions are driven by a favorable negative enthalpy change combined with an unfavorable decrease in entropy. The heat capacity changes (ΔCp ) for all of the interactions are zero, indicating an insignificant contribution from hydrophobic interactions.


Assuntos
Sulfatos de Condroitina/farmacologia , Simulação de Acoplamento Molecular , Poliéster Sulfúrico de Pentosana/farmacologia , Suramina/farmacologia , Inibidor Tecidual de Metaloproteinase-3/química , Sítios de Ligação , Sulfatos de Condroitina/química , Humanos , Poliéster Sulfúrico de Pentosana/química , Ligação Proteica , Suramina/química , Inibidor Tecidual de Metaloproteinase-3/metabolismo
5.
J Pharmacol Exp Ther ; 372(1): 63-72, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31636173

RESUMO

The objective of this study was to investigate the role of ATP in cholinergic neurotransmission in the urinary bladder of control men and of patients obstructed as a result of benign prostatic hyperplasia (BPH). Human detrusor samples were collected from 41 patients who submitted to transvesical prostatectomy resulting from BPH and 26 male organ donors. The release of [3H]acetylcholine ([3H]ACh) was evoked by electrical field stimulation (10 Hz, 200 pulses) in urothelium-denuded detrusor strips. Myographic recordings were performed to test detrusor strip sensitivity to ACh and ATP. Nerve-evoked [3H]ACh release was 1.5-fold higher in detrusor strips from BPH patients compared with controls. This difference was abolished after desensitization of ionotropic P2X1-3 receptors with an ATP analog, α,ß-methylene ATP (30 µM, applied for 15 minutes). TNP-ATP (10 nM, a preferential P2X2/3 antagonist) and A317491 (100 nM, a selective P2X3 antagonist) were about equipotent in decreasing nerve-evoked [3H]ACh release in control detrusor strips, but the selective P2X1 receptor antagonist NF023 (3 µM) was devoid of effect. The inhibitory effect of TNP-ATP (10 nM) increased from 27% ± 9% to 43% ± 6% in detrusor strips of BPH patients, but the effect of A317491 (100 nM) [3H]ACh release unaltered (20% ± 2% vs. 24% ± 4%). The amplitude of ACh (0.1-100 µM)-induced myographic recordings decreased, whereas sensitivity to ATP (0.01-3 mM) increased in detrusor strips from BPH patients. Besides the well characterized P2X1 receptor-mediated contractile activity of ATP in pathologic human bladders, we show here for the first time that cholinergic hyperactivity in the detrusor of BPH patients is facilitated by activation of ATP-sensitive P2X2/3 heterotrimers. SIGNIFICANCE STATEMENT: Bladder outlet obstruction often leads to detrusor overactivity and reduced bladder compliance in parallel to atropine-resistant increased purinergic tone. Our data show that P2X1 purinoceptors are overexpressed in the detrusor of patients with benign prostatic hyperplasia. Besides the P2X1 receptor-mediated detrusor contractions, ATP favors nerve-evoked acetylcholine release via the activation of prejunctional P2X2/3 excitatory receptors in these patients Thus, our hypothesis is that manipulation of the purinergic tone may be therapeutically useful to counteract cholinergic overstimulation in obstructed patients.


Assuntos
Trifosfato de Adenosina/metabolismo , Tono Muscular , Receptores Purinérgicos P2X1/metabolismo , Obstrução do Colo da Bexiga Urinária/metabolismo , Acetilcolina/metabolismo , Adulto , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Contração Muscular , Fenóis/farmacologia , Compostos Policíclicos/farmacologia , Multimerização Proteica , Antagonistas do Receptor Purinérgico P2X/farmacologia , Suramina/análogos & derivados , Suramina/farmacologia , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/metabolismo , Bexiga Urinária/fisiopatologia , Obstrução do Colo da Bexiga Urinária/fisiopatologia
6.
Eur J Med Chem ; 186: 111789, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31727469

RESUMO

Dual- or multi-target drugs are particularly promising for the treatment of complex diseases such as (neuro)inflammatory disorders. In the present study, we identified dual antagonists for two related pro-inflammatory G protein-coupled receptors (GPCRs), the purinergic receptor P2Y2 receptor, and the orphan receptor GPR17. Based on the lead compound suramin small molecules were designed, synthesized, and modified, including benzenesulfonate, benzenesulfonamide, dibenzamide and diphenylurea derivatives. Structure-activity relationship studies identified 3-nitrophenyl 4-benzamidobenzenesulfonic acid derivatives as dual P2Y2R/GPR17 antagonists. In particular, 3-nitrophenyl 4-(4-chlorobenzamido)benzenesulfonate (14l, IC50 3.01 µM at P2Y2R, and 3.37  µM at GPR17) and 3-nitrophenyl-4-(2-chlorobenzamido)benzenesulfonate (14m, IC50 3.17 µM at P2Y2R, and 1.67 µM at GPR17) exhibited dual antagonistic activity. Compound 14l was shown to act as an allosteric antagonist at both receptors. In addition, GPR17-selective antagonists were identified including 3-nitrophenyl 4-benzamidobenzenesulfonate (14a, IC50 3.20 µM) and 3-nitrophenyl 4-(3-(trifluoromethyl)benzamido)benzenesulfonate (14f, IC50 3.88 µM). The developed antagonists were selective versus other closely related P2Y receptors. They were found to possess high chemical and metabolic stability in human liver microsomes and therefore present good starting points for developing potent multi-target drugs with potential applications in inflammatory diseases.


Assuntos
Desenho de Fármacos , Receptores Acoplados a Proteínas-G/antagonistas & inibidores , Receptores Purinérgicos P2Y2/metabolismo , Suramina/farmacologia , Animais , Células CHO , Cricetulus , Relação Dose-Resposta a Droga , Humanos , Microssomos Hepáticos/química , Microssomos Hepáticos/metabolismo , Estrutura Molecular , Receptores Acoplados a Proteínas-G/metabolismo , Relação Estrutura-Atividade , Suramina/síntese química , Suramina/química
7.
Biotechnol Lett ; 41(11): 1255-1263, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31541331

RESUMO

OBJECTIVE: To examine the effects of suramin in CHO cell cultures in terms of the cell culture performance and quality of the Fc-fusion protein. RESULTS: Suramin had positive effects on the CHO cell cultures. The addition of suramin caused an increase in the viable cell density, cell viability, and titer of the Fc-fusion protein. Moreover, suramin had no impact on protein aggregation and enhanced the sialic acid contents of Fc-fusion protein by 1.18-fold. The enhanced sialylation was not caused by the increased nucleotide sugar level but by the inhibition of sialidase activity. The results showed that suramin inhibited apoptosis and had positive impacts on the productivity and quality of Fc-fusion protein. CONCLUSION: The addition of suramin increased the production of Fc-fusion protein and enhanced sialylation when added as a supplement to the media component in CHO cell cultures. This study suggested that suramin could be a beneficial additive during the biological production in terms of the productivity and quality of Fc-fusion protein.


Assuntos
Técnicas de Cultura de Células/métodos , Fragmentos Fc das Imunoglobulinas/metabolismo , Proteínas Recombinantes/metabolismo , Suramina/farmacologia , Animais , Células CHO , Morte Celular/efeitos dos fármacos , Cricetinae , Cricetulus , Glicosilação , Fragmentos Fc das Imunoglobulinas/genética , Ácido N-Acetilneuramínico/metabolismo , Proteínas Recombinantes/genética
8.
Am J Physiol Gastrointest Liver Physiol ; 317(4): G463-G475, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31433214

RESUMO

In the current study, we explored the role of extracellular ATP (eATP) in promoting systemic inflammation during development of acute pancreatitis (AP). Release of extracellular (e)ATP was evaluated in plasma and bronchoalveolar lavage fluid (BALF) of mice with experimental acute pancreatitis (AP). Prophylactic intervention using apyrase or suramin was used to understand the role and contribution of eATP in pancreatitis-associated systemic injury. AP of varying severity was induced in C57BL/6 mice using 1-day or 2-day caerulein, caerulein + LPS and l-arginine models. eATP was measured in plasma and BALF. Mice were treated with suramin or apyrase in the caerulein and l-arginine models of AP. Plasma cytokines, lung, and pancreatic myeloperoxidase, and morphometric analysis of pancreatic and lung histology, were used to assess the severity of pancreatitis. Plasma eATP and purinergic 2 (P2) receptors in the pancreas and lungs were significantly elevated in the experimental models of AP. Blocking the effect of eATP by suramin led to reduced levels of plasma IL-6 and TNFα as well as reduced lung, and pancreatic injury. Neutralizing eATP with apyrase reduced systemic injury but did not ameliorate local injury. The results of this study support the role of eATP and P2 receptors in promoting systemic inflammation during AP. Modulating purinergic signaling during AP can be an important therapeutic strategy in controlling systemic inflammation and, thus, systemic inflammatory response syndrome during AP.NEW & NOTEWORTHY Released ATP from injured cells promotes systemic inflammation in acute pancreatitis.


Assuntos
Trifosfato de Adenosina/metabolismo , Inflamação/metabolismo , Pancreatite/metabolismo , Doença Aguda , Trifosfato de Adenosina/sangue , Animais , Apirase/farmacologia , Arginina , Líquido da Lavagem Broncoalveolar/química , Ceruletídeo , Citocinas/sangue , Citocinas/metabolismo , Inflamação/induzido quimicamente , Inflamação/prevenção & controle , Pulmão/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Pâncreas/metabolismo , Pancreatite/induzido quimicamente , Pancreatite/prevenção & controle , Peroxidase/metabolismo , Receptores Purinérgicos/metabolismo , Transdução de Sinais , Suramina/farmacologia
9.
Open Biol ; 9(8): 190117, 2019 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-31409229

RESUMO

Minichromosome maintenance protein 10 (Mcm10) is essential for DNA unwinding by the replisome during S phase. It is emerging as a promising anti-cancer target as MCM10 expression correlates with tumour progression and poor clinical outcomes. Here we used a competition-based fluorescence polarization (FP) high-throughput screening (HTS) strategy to identify compounds that inhibit Mcm10 from binding to DNA. Of the five active compounds identified, only the anti-parasitic agent suramin exhibited a dose-dependent decrease in replication products in an in vitro replication assay. Structure-activity relationship evaluation identified several suramin analogues that inhibited ssDNA binding by the human Mcm10 internal domain and full-length Xenopus Mcm10, including analogues that are selective for Mcm10 over human RPA. Binding of suramin analogues to Mcm10 was confirmed by surface plasmon resonance (SPR). SPR and FP affinity determinations were highly correlated, with a similar rank between affinity and potency for killing colon cancer cells. Suramin analogue NF157 had the highest human Mcm10 binding affinity (FP Ki 170 nM, SPR KD 460 nM) and cell activity (IC50 38 µM). Suramin and its analogues are the first identified inhibitors of Mcm10 and probably block DNA binding by mimicking the DNA sugar phosphate backbone due to their extended, polysulfated anionic structures.


Assuntos
Inibidores Enzimáticos/farmacologia , Proteínas de Manutenção de Minicromossomo/antagonistas & inibidores , Suramina/farmacologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Replicação do DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/antagonistas & inibidores , Descoberta de Drogas/métodos , Inibidores Enzimáticos/química , Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Cinética , Proteínas de Manutenção de Minicromossomo/genética , Estrutura Molecular , Ligação Proteica , Suramina/análogos & derivados , Suramina/química , Xenopus
10.
J Physiol ; 597(19): 4991-5008, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31426127

RESUMO

KEY POINTS: Adenosine and ATP are excitatory neurotransmitters involved in the carotid body (CB) response to hypoxia. During ageing the CB exhibits a decline in its functionality, demonstrated by decreased hypoxic responses. In aged rats (20-24 months old) there is a decrease in: basal and hypoxic release of adenosine and ATP from the CB; expression of adenosine and ATP receptors in the petrosal ganglion; carotid sinus nerve (CSN) activity in response to hypoxia; and ventilatory responses to ischaemic hypoxia. There is also an increase in SNAP25, ENT1 and CD73 expression. It is concluded that, although CSN activity and ventilatory responses to hypoxia decrease with age, adjustments in purinergic metabolism in the CB in aged animals are present aiming to maintain the contribution of adenosine and ATP. The possible significance of the findings in the context of ageing and in CB-associated pathologies is considered. ABSTRACT: During ageing the carotid body (CB) exhibits a decline in its functionality. Here we investigated the effect of ageing on functional CB characteristics as well as the contribution of adenosine and ATP to CB chemosensory activity. Experiments were performed in 3-month-old and 20- to 24-month-old male Wistar rats. Ageing decreased: the number of tyrosine hydroxylase immune-positive cells, but not type II cells or nestin-positive cells in the CB; the expression of P2X2 and A2A receptors in the petrosal ganglion; and the basal and hypoxic release of adenosine and ATP from the CB. Ageing increased ecto-nucleotidase (CD73) immune-positive cells and the expression of synaptosome associated protein 25 (SNAP25) and equilibrative nucleoside transporter 1 (ENT1) in the CB. Additionally, ageing did not modify basal carotid sinus nerve (CSN) activity or the activity in response to hypercapnia, but decreased CSN activity in hypoxia. The contribution of adenosine and ATP to stimuli-evoked CSN chemosensory activity in aged animals followed the same pattern of 3-month-old animals. Bilateral common carotid occlusions during 5, 10 and 15 s increased ventilation proportionally to the duration of ischaemia, an effect decreased by ageing. ATP contributed around 50% to ischaemic-ventilatory responses in young and aged rats; the contribution of adenosine was dependent on the intensity of ischaemia, being maximal in ischaemias of 5 s (50%) and much smaller in 15 s ischaemias. Our results demonstrate that both ATP and adenosine contribute to CB chemosensory activity in ageing. Though CB responses to hypoxia, but not to hypercapnia, decrease with age, the relative contribution of both ATP and adenosine for CB activity is maintained.


Assuntos
Trifosfato de Adenosina/metabolismo , Adenosina/metabolismo , Corpo Carotídeo/fisiologia , Células Quimiorreceptoras/metabolismo , Envelhecimento , Animais , Antinematódeos/farmacologia , Corpo Carotídeo/citologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Suramina/farmacologia , Triazinas/farmacologia , Triazóis/farmacologia
11.
J Biol Chem ; 294(37): 13740-13754, 2019 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-31346035

RESUMO

Seminal amyloid fibrils are made up of naturally occurring peptide fragments and are key targets for the development of combination microbicides or antiviral drugs. Previously, we reported that the polysulfonic compound ADS-J1 is a potential candidate microbicide that not only inhibits HIV-1 entry, but also seminal fibrils. However, the carcinogenic azo moieties in ADS-J1 preclude its clinical application. Here, we screened several ADS-J1-like analogs and found that the antiparasitic drug suramin most potently inhibited seminal amyloid fibrils. Using various biochemical methods, including Congo red staining, CD analysis, transmission EM, viral infection assays, surface plasmon resonance imaging, and molecular dynamics simulations, we investigated suramin's inhibitory effects and its putative mechanism of action. We found that by forming a multivalent interaction, suramin binds to proteolytic peptides and mature fibrils, thereby inhibiting seminal fibril formation and blocking fibril-mediated enhancement of viral infection. Of note, suramin exhibited potent anti-HIV activities, and combining suramin with several antiretroviral drugs produced synergistic effects against HIV-1 in semen. Suramin also displayed a good safety profile for vaginal application. Moreover, suramin inhibited the semen-derived enhancer of viral infection (SEVI)/semen-mediated enhancement of HIV-1 transcytosis through genital epithelial cells and the subsequent infection of target cells. Collectively, suramin has great potential for further development as a combination microbicide to reduce the spread of the AIDS pandemic by targeting both viral and host factors involved in HIV-1 sexual transmission.


Assuntos
Amiloide/efeitos dos fármacos , Sêmen/efeitos dos fármacos , Suramina/farmacologia , Adulto , Animais , Fármacos Anti-HIV/farmacologia , Antirretrovirais/farmacologia , Infecções por HIV/metabolismo , HIV-1/metabolismo , Voluntários Saudáveis , Humanos , Masculino , Fragmentos de Peptídeos/metabolismo , Peptídeos/metabolismo , Coelhos , Sêmen/metabolismo , Suramina/metabolismo
12.
Artif Cells Nanomed Biotechnol ; 47(1): 1839-1845, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31066305

RESUMO

Atherosclerosis is the chronic inflammatory disease, and inflammation-elicited endothelial activation is an early event in the development of atherosclerosis. The P2Y11 receptor is a purinergic receptor and a member of the P2 family of G coupled protein which has been shown to modulate vascular function. Progress in the study of purine receptors has been tremendous and these receptors have become pharmacological targets for various diseases. In this study, we show that the P2Y11R antagonist NF157 can mitigate oxidized LDL (ox-LDL)-induced endothelial inflammation. Our study demonstrates that P2Y11R is expressed to a fair degree in human aortic endothelial cells and is induced by treatment with ox-LDL. Blockage of P2Y11R by its selective antagonist NF157 ameliorates ox-LDL-induced adhesion of THP-1 monocytes to endothelial cells. NF157 inhibits ox-LDL-induced expression of adhesion molecules including E-selectin and VCAM-1. NF157 also suppresses ox-LDL-associated ROS production and induction of the NADPH oxidase subunit NOX-4. Moreover, NF157 has an inhibitory effect on the production of major cytokines including IL-6 and TNF-α. Mechanistically, we show that NF157 mitigates ox-LDL-induced phosphorylation of MAPK kinase p38 and NF-κB activation. Our findings indicate that blockage of P2Y11R signalling by its antagonist NF157 may protect endothelial cells from ox-LDL-induced endothelial inflammation. Therefore, NF157 may have therapeutic implications in the modulation of atherosclerosis-associated inflammation.


Assuntos
Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Lipoproteínas LDL/farmacologia , Receptores Purinérgicos P2/metabolismo , Suramina/análogos & derivados , Adesão Celular/efeitos dos fármacos , Selectina E/genética , Ativação Enzimática/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , Inflamação/tratamento farmacológico , Interleucina-6/biossíntese , Monócitos/citologia , Monócitos/efeitos dos fármacos , NF-kappa B/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Suramina/farmacologia , Suramina/uso terapêutico , Fator de Necrose Tumoral alfa/biossíntese , Molécula 1 de Adesão de Célula Vascular/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
13.
J Med Chem ; 62(8): 4110-4119, 2019 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-30925051

RESUMO

Zika virus (ZIKV), a mosquito-borne flavivirus, is a global health concern because of its association with severe neurological disorders. Currently, there are no antiviral therapies that have been specifically approved to treat ZIKV, and there is an urgent need to develop effective anti-ZIKV agents. Here, we report anti-ZIKV activity of 16 synthetic carbohydrate receptors (SCRs) that inhibit ZIKV infection in Vero and HeLa cells. Using a ZIKV reporter virus particle-based infection assay, our data demonstrates these SCRs are highly potent with IC50s as low as 0.16 µM and negligible toxicity at several-fold higher concentrations. Time-of-addition studies showed that these SCRs inhibit the early stages of the virus infection, which is consistent with the proposed mode of action, where the SCRs likely inhibit binding between the virus and cell-surface glycans, thereby preventing viral entry into the cells and, as such, this study demonstrates a potential new strategy against ZIKV.


Assuntos
Antivirais/química , Carboidratos/química , Receptores Artificiais/química , Zika virus/fisiologia , Animais , Antivirais/farmacologia , Antivirais/uso terapêutico , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Células HeLa , Humanos , Receptores Artificiais/síntese química , Receptores Artificiais/metabolismo , Relação Estrutura-Atividade , Suramina/química , Suramina/farmacologia , Células Vero , Internalização do Vírus/efeitos dos fármacos , Infecção por Zika virus/tratamento farmacológico , Infecção por Zika virus/patologia
14.
Viruses ; 11(3)2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30870979

RESUMO

Epidemic keratoconjunctivitis (EKC) is a severe ocular disease and can lead to visual impairment. Human adenovirus type-37 (HAdV-D37) is one of the major causative agents of EKC and uses sialic acid (SA)-containing glycans as cellular receptors. Currently, there are no approved antivirals available for the treatment of EKC. Recently, we have reported that sulfated glycosaminoglycans (GAGs) bind to HAdV-D37 via the fiber knob (FK) domain of the viral fiber protein and function as decoy receptors. Based on this finding, we speculated that GAG-mimetics may act as artificial decoy receptors and inhibit HAdV-D37 infection. Repurposing of approved drugs to identify new antivirals has drawn great attention in recent years. Here, we report the antiviral effect of suramin, a WHO-approved drug and a widely known GAG-mimetic, against HAdV-D37. Commercially available suramin analogs also show antiviral effects against HAdV-D37. We demonstrate that suramin exerts its antiviral activity by inhibiting the attachment of HAdV-D37 to cells. We also reveal that the antiviral effect of suramin is HAdV species-specific. Collectively, in this proof of concept study, we demonstrate for the first time that virus binding to a decoy receptor constitutes a novel and an unexplored target for antiviral drug development.


Assuntos
Adenovírus Humanos/efeitos dos fármacos , Ceratoconjuntivite/virologia , Receptores Virais/metabolismo , Suramina/farmacologia , Ligação Viral/efeitos dos fármacos , Células A549 , Infecções por Adenovirus Humanos/tratamento farmacológico , Infecções por Adenovirus Humanos/virologia , Sítios de Ligação , DNA Viral , Reposicionamento de Medicamentos , Genoma Viral , Humanos , Ceratoconjuntivite/tratamento farmacológico , Filogenia , Estudo de Prova de Conceito , Análise de Sequência de DNA
15.
ACS Chem Neurosci ; 10(5): 2459-2466, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30892011

RESUMO

Adenosine triphosphate (ATP) is the main energy source for cellular metabolism. Besides that, ATP is a neurotransmitter and a cotransmitter that acts on purinergic receptors present either pre- or postsynaptically. Almost all types of secretory vesicles from any neuron or animal species contain high concentrations of ATP, being an essential factor in the accumulation of neurotransmitters. In this work, we studied the effects of ATP on quantum catecholamine release and vesicular storage in chromaffin cells. We combined three electrochemical methods: conventional amperometry with intracellular vesicle impact electrochemical cytometry and vesicle impact electrochemical cytometry. We found that extracellular ATP increased the released quantal fraction of catecholamine but not its vesicular content. Studying the dynamics of exocytosis events in ATP treated cells showed that ATP affects the release fusion pore. To elucidate the mechanisms of the observed ATP effects, cells and vesicles were pharmacologically treated with suramin (a purinergic blocker) and ARL-67156 (an antagonist of ecto-ATPases). The data indicate that the catecholamine content of vesicles increased compared to control after these drugs. Our data suggest that ATP acting on purinergic receptors increases the quantum releasable size through an increased fusion pore opening and that ARL-67156 and/or suramin protect the vesicle from neurotransmitter leakage by functioning as competitive inhibitors to ATP.


Assuntos
Trifosfato de Adenosina/fisiologia , Células Cromafins/fisiologia , Exocitose/fisiologia , Trifosfato de Adenosina/análogos & derivados , Trifosfato de Adenosina/farmacologia , Animais , Catecolaminas/metabolismo , Bovinos , Células Cultivadas , Agonistas Purinérgicos/farmacologia , Receptores Purinérgicos P1/metabolismo , Receptores Purinérgicos P2/metabolismo , Suramina/farmacologia
16.
J Physiol Sci ; 69(3): 489-502, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30771091

RESUMO

An uncontrolled inflammatory response has been implicated in the progression of acute liver failure through poorly understood mechanisms. The aim of our study was to investigate whether suramin attenuates inflammation-mediated hepatocyte apoptosis by modulating mitochondrial homeostasis. Primary hepatocytes were isolated from mice and treated with LPS in vitro in the presence or absence of suramin. Western blotting, immunofluorescence staining, and ELISAs were used to evaluate the mitochondrial stress. The LPS treatment caused hepatocyte death via apoptosis. Interestingly, suramin supplementation attenuated LPS-mediated hepatocyte death by reducing Mst1 expression; the overexpression of Mst1 abolished the anti-apoptotic effects of suramin on LPS-treated hepatocytes. At the molecular level, suramin treatment repressed mitochondrial oxidative stress, sustained mitochondrial dynamics and blocked the caspase-9-mediated mitochondrial apoptosis pathway; these effects of suramin were achieved by reversing Mst1 expression. Furthermore, our study found that suramin modulated Mst1 expression via the JNK signaling pathway. Activation of JNK prevented the suramin-mediated Mst1 downregulation and concomitantly increased hepatocyte apoptosis and mitochondrial dysfunction. Taken together, our results confirmed the anti-apoptotic and anti-inflammatory effects of suramin on LPS-challenged hepatocytes. Suramin sustained hepatocyte viability and attenuated mitochondrial stress via repressing the JNK-Mst1 signaling pathway.


Assuntos
Apoptose/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/metabolismo , Suramina/farmacologia , Animais , Caspase 9/metabolismo , Regulação para Baixo/efeitos dos fármacos , Feminino , Hepatócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Doenças Mitocondriais/tratamento farmacológico , Doenças Mitocondriais/metabolismo , Dinâmica Mitocondrial/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
17.
Chembiochem ; 20(12): 1578-1590, 2019 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-30720915

RESUMO

Antimicrobial peptides (AMPs) kill bacteria by targeting their membranes through various mechanisms involving peptide assembly, often coupled with disorder-to-order structural transition. However, for several AMPs, similar conformational changes in cases in which small organic compounds of both endogenous and exogenous origin have induced folded peptide conformations have recently been reported. Thus, the function of AMPs and of natural host defence peptides can be significantly affected by the local complex molecular environment in vivo; nonetheless, this area is hardly explored. To address the relevance of such interactions with regard to structure and function, we have tested the effects of the therapeutic drug suramin on the membrane activity and antibacterial efficiency of CM15, a potent hybrid AMP. The results provided insight into a dynamic system in which peptide interaction with lipid bilayers is interfered with by the competitive binding of CM15 to suramin, resulting in an equilibrium dependent on peptide-to-drug ratio and vesicle surface charge. In vitro bacterial tests showed that when CM15⋅suramin complex formation dominates over membrane binding, antimicrobial activity is abolished. On the basis of this case study, it is proposed that small-molecule secondary structure regulators can modify AMP function and that this should be considered and could potentially be exploited in future development of AMP-based antimicrobial agents.


Assuntos
Anti-Infecciosos , Peptídeos Catiônicos Antimicrobianos , Suramina , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Células Cultivadas , Dicroísmo Circular/métodos , Escherichia coli , Humanos , Bicamadas Lipídicas/química , Estrutura Secundária de Proteína , Suramina/química , Suramina/farmacologia
18.
J Physiol ; 597(7): 1819-1831, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30693527

RESUMO

KEY POINTS: The prevailing dogma about neurogenic regulation of vascular tone consists of major vasodilatation caused by CGRP (and possibly substance P) released from sensory-motor nerves and vasoconstriction caused by noradrenaline, ATP and neuropeptode Y release from sympathetic nerves. Most studies on perivascular nerve-mediated vasodilatation are made in vitro. In the present study, we provide evidence indicating that in vivo electrical perivascular nerve stimulation in rat mesenteric small arteries causes a large ß1-adrenoceptor-mediated vasodilatation, which contrasts with a smaller vasodilatation caused by endogenous CGRP that is only visible after inhibition of Y1 NPY receptors. ABSTRACT: Mesenteric arteries are densely innervated and the nerves are important regulators of vascular tone and hence blood pressure and blood flow. Perivascular sensory-motor nerves have been shown to cause vasodilatation in vitro. However, less is known about their function in vivo. Male Wistar rats (10-12 weeks old; n = 72) were anaesthetized with ketamine (3 mg kg-1 ) and xylazine (0.75 mg kg-1 ) or pentobarbital (60 mg kg-1 ). After a laparotomy, a section of second-order mesenteric artery was visualized in an organ bath after minimal removal of perivascular adipose tissue. The effects of electrical field stimulation (EFS) and drugs on artery diameter and blood flow were recorded with intravital microscopy and laser speckle imaging. EFS caused vasodilatation in arteries constricted with 1 µm U46619 in the presence of 140 µm suramin and 1 µm prazosin. The vasodilatation was inhibited by 1 µm tetrodotoxin and 5 µm guanethidine, although not by the 1 µm of the CGRP receptor antagonist BIBN4096bs. In the presence of 0.3 µm Y1 receptor antagonist BIBP3226, BIBN4096bs partly inhibited the vasodilatation. Atenolol at a concentration 1 µm inhibited the vasodilatation, whereas 0.1 µm of the ß2 -adrenoceptor selective antagonist ICI-118,551 had no effect. Increasing the extracellular [K+ ] to 20 mm caused vasodilatation but was converted to vasoconstriction in the presence of 1 µm BIBN4096bs, and constriction to 30 mm potassium was potentiated by BIBN4096bs. Atenolol but not BIBN4096bs increased contraction to EFS in the absence of suramin and prazosin. In mesenteric small arteries of anaesthetized rats, EFS failed to stimulate major dilatation via sensory-motor nerves but induced sympathetic ß1 -adrenoceptor-mediated dilatation.


Assuntos
Artérias Mesentéricas/fisiologia , Receptores Adrenérgicos beta 1/fisiologia , Vasodilatação/fisiologia , Antagonistas de Receptores Adrenérgicos alfa 1/farmacologia , Antagonistas de Receptores Adrenérgicos beta 1/farmacologia , Animais , Antinematódeos/farmacologia , Atenolol/farmacologia , Masculino , Artérias Mesentéricas/efeitos dos fármacos , Piperazinas/farmacologia , Prazosina/farmacologia , Quinazolinas/farmacologia , Ratos , Ratos Wistar , Suramina/farmacologia , Técnicas de Cultura de Tecidos , Vasoconstrição/efeitos dos fármacos , Vasoconstrição/fisiologia , Vasodilatação/efeitos dos fármacos
19.
Acta Biomater ; 84: 378-390, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30528604

RESUMO

Suramin (SM), a drug for African sleeping sickness and river blindness therapy, has been investigated in various clinical trials for cancer therapy. However, SM was eventually withdrawn from the market because of its narrow therapeutic window and the side effects associated with multiple targets. In this work, we developed a simple but effective system based on a nontoxic dose of SM combined with a chemotherapeutic agent for the treatment of metastatic triple-negative breast cancer (TNBC). SM and glycol chitosan (GCS) formed nanogels because of the electrostatic effect, whereas doxorubicin (DOX) was incorporated into the system through the hydrophilic and hydrophobic interactions between DOX and GCS as well as the ionic interactions between DOX and SM to yield GCS-SM/DOX nanoparticles (NPs). GCS-SM/DOX NPs have a size of approximately 186 nm and a spherical morphology. In vitro experiments showed that GCS-SM NPs could effectively inhibit cancer cell migration and invasion, as well as angiogenesis. Furthermore, in a TNBC lung metastasis animal model, GCS-SM/DOX NPs significantly reduced tumor burden and extended the lifespan of animals, while not inducing cardio and renal toxicities associated with the DOX and SM, respectively. As all the components used in this system are biocompatible and easy for large-scale fabrication, the GCS-SM/DOX system is highly translatable for the metastatic breast cancer treatment. STATEMENT OF SIGNIFICANCE: The doxorubicin-loaded glycol chitosan-suramin nanoparticle (GCS-SM/DOX) is novel in the following aspects: SM acts as not only a gelator for the first time in the preparation of the nanoparticle but also an active pharmaceutical agent in the dosage form. GCS-SM/DOX NP significantly reduced tumor burden and extended the lifespan of animals with triple-negative breast cancer lung metastasis. GCS-SM/DOX NPs attenuate cardio and renal toxicities associated with the DOX and SM. The GCS-SM/DOX system is highly translatable because of its simple, one-pot, and easy-to-scale-up preparation protocol.


Assuntos
Quitosana , Doxorrubicina , Neoplasias Pulmonares , Nanopartículas , Suramina , Neoplasias de Mama Triplo Negativas , Animais , Linhagem Celular Tumoral , Quitosana/química , Quitosana/farmacocinética , Quitosana/farmacologia , Doxorrubicina/química , Doxorrubicina/farmacocinética , Doxorrubicina/farmacologia , Feminino , Células Endoteliais da Veia Umbilical Humana , Humanos , Interações Hidrofóbicas e Hidrofílicas , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Camundongos , Camundongos Nus , Nanopartículas/química , Nanopartículas/uso terapêutico , Metástase Neoplásica , Suramina/química , Suramina/farmacocinética , Suramina/farmacologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Int J Biol Macromol ; 125: 459-468, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30529553

RESUMO

Currently no effective treatment is available to combat infections caused by Corynebacterium pseudotuberculosis in livestock. Survival of this Gram-positive bacterium in rapidly-growing pathogens in hostile environments is strongly dependent on the existence of a robust DNA repair system to prevent DNA mutations and contribute to bacterial colonization and virulence. The adenine/guanine-specific DNA glycosylase (MutY) is evolutionarily conserved and has been well characterized due to its central role in the prevention of mutagenesis and DNA repair. The aim of this study was the characterization of the target protein interaction with free adenine, suramin, and heparin, as well as the binding competition characterization between the molecules. The dissociation constant for free adenine interaction with Corynebacterium pseudotuberculosis MutY (Cp-MutY) was determined, 86 ±â€¯2.5 µM. NMR competition experiments demonstrated, that the polyanions heparin and suramin compete with adenine for the protein active site. The determined dissociation constant for the heparin/Cp-MutY interaction was 5.9 ±â€¯1.0 µM and for suramin was 16 ±â€¯1.5 µM. Docking of both polyanions with Cp-MutY revealed a possible mode of interaction and indicates that these molecules can interfere with the protein interaction with damaged DNA or prevent the binding of the adenine base in the enzyme active site.


Assuntos
Adenina/metabolismo , Corynebacterium pseudotuberculosis/efeitos dos fármacos , DNA/metabolismo , Heparina/farmacologia , Polímeros/farmacologia , Suramina/farmacologia , Domínio Catalítico/efeitos dos fármacos , DNA Glicosilases/metabolismo , Reparo do DNA/efeitos dos fármacos , Guanina/metabolismo , Cinética , Mutagênese/efeitos dos fármacos , Mutação/efeitos dos fármacos , N-Glicosil Hidrolases/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA