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1.
Eur J Med Chem ; 214: 113210, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33550183

RESUMO

Protein-protein interactions (PPIs) play a critical role in living cells and represent promising targets for the drug discovery and life sciences communities. However, lateral transmembrane PPIs are difficult targets for small-molecule inhibitor development given less structural information is known and fewer ligand discovery methods have been explored compared to soluble proteins. In this study, the interactions of the transmembrane domain 5 (TMD-5) of latent membrane protein 1 (LMP-1) of Epstein-Barr virus (EBV) were disrupted by pentamidine derivatives to curb the committed step of EBV infection. A pentamidine derivative 2 with a 7-atom di-amide linker had the best activity whilst switching the amide regiochemistry in the linker influenced membrane permeability and abolished anti TMD-5 activity. Molecular dynamics simulations were performed to understand the interaction between pentamidine derivatives and TMD-5, and to rationalise the observed structure-activity relationships. This study explicitly demonstrated that the interaction of small molecule with lipid should be considered alongside interaction with the protein target when designing small molecules targeting the PPIs of TMDs. In all, this study provides proof of concept for the rational design of small molecules targeting transmembrane PPIs.


Assuntos
Pentamidina/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Proteínas da Matriz Viral/antagonistas & inibidores , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cães , Relação Dose-Resposta a Droga , Modelos Moleculares , Estrutura Molecular , Pentamidina/química , Bibliotecas de Moléculas Pequenas/química , Relação Estrutura-Atividade , Proteínas da Matriz Viral/metabolismo
2.
RNA ; 27(1): 12-26, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33028652

RESUMO

Identifying small molecules that selectively bind an RNA target while discriminating against all other cellular RNAs is an important challenge in RNA-targeted drug discovery. Much effort has been directed toward identifying drug-like small molecules that minimize electrostatic and stacking interactions that lead to nonspecific binding of aminoglycosides and intercalators to many stem-loop RNAs. Many such compounds have been reported to bind RNAs and inhibit their cellular activities. However, target engagement and cellular selectivity assays are not routinely performed, and it is often unclear whether functional activity directly results from specific binding to the target RNA. Here, we examined the propensities of three drug-like compounds, previously shown to bind and inhibit the cellular activities of distinct stem-loop RNAs, to bind and inhibit the cellular activities of two unrelated HIV-1 stem-loop RNAs: the transactivation response element (TAR) and the rev response element stem IIB (RREIIB). All compounds bound TAR and RREIIB in vitro, and two inhibited TAR-dependent transactivation and RRE-dependent viral export in cell-based assays while also exhibiting off-target interactions consistent with nonspecific activity. A survey of X-ray and NMR structures of RNA-small molecule complexes revealed that aminoglycosides and drug-like molecules form hydrogen bonds with functional groups commonly accessible in canonical stem-loop RNA motifs, in contrast to ligands that specifically bind riboswitches. Our results demonstrate that drug-like molecules can nonspecifically bind stem-loop RNAs most likely through hydrogen bonding and electrostatic interactions and reinforce the importance of assaying for off-target interactions and RNA selectivity in vitro and in cells when assessing novel RNA-binders.


Assuntos
Aminoglicosídeos/farmacologia , Genes env/efeitos dos fármacos , Repetição Terminal Longa de HIV/efeitos dos fármacos , RNA Viral/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Aminoglicosídeos/química , Aminoglicosídeos/metabolismo , Pareamento de Bases , Sequência de Bases , Sítios de Ligação , Bioensaio , Descoberta de Drogas , HIV-1/efeitos dos fármacos , HIV-1/genética , HIV-1/metabolismo , Humanos , Ligação de Hidrogênio , Isoquinolinas/química , Isoquinolinas/metabolismo , Isoquinolinas/farmacologia , Conformação de Ácido Nucleico , Pentamidina/química , Pentamidina/metabolismo , Pentamidina/farmacologia , RNA Viral/genética , RNA Viral/metabolismo , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/metabolismo , Eletricidade Estática , Ativação Transcricional/efeitos dos fármacos , Ioimbina/química , Ioimbina/metabolismo , Ioimbina/farmacologia
3.
Parasitology ; 148(1): 98-104, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33023678

RESUMO

Cutaneous leishmaniasis (CL) is one of the most disregarded tropical neglected disease with the occurrence of self-limiting ulcers and triggering mucosal damage and stigmatizing scars, leading to huge public health problems and social negative impacts. Pentavalent antimonials are the first-line drug for CL treatment for over 70 years and present several drawbacks in terms of safety and efficacy. Thus, there is an urgent need to search for non-invasive, non-toxic and potent drug candidates for CL. In this sense, we have implemented a shape-based virtual screening approach and identified a set of 32 hit compounds. In vitro phenotypic screenings were conducted using these hit compounds to check their potential leishmanicidal effect towards Leishmania amazonensis (L. amazonensis). Two (Cp1 and Cp2) out of the 32 compounds revealed promising antiparasitic activities, exhibiting considerable potency against intracellular amastigotes present in peritoneal macrophages (IC50 values of 9.35 and 7.25 µm, respectively). Also, a sterile cidality profile was reached at 20 µm after 48 h of incubation, besides a reasonable selectivity (≈8), quite similarly to pentamidine, a diamidine still in use clinically for leishmaniasis. Cp1 with an oxazolo[4,5-b]pyridine scaffold and Cp2 with benzimidazole scaffold could be developed by lead optimization studies to enhance their leishmanicidal potency.


Assuntos
Antiprotozoários/farmacologia , Avaliação Pré-Clínica de Medicamentos , Leishmaniose Cutânea/tratamento farmacológico , Macrófagos Peritoneais/parasitologia , Animais , Benzimidazóis/farmacologia , Células Cultivadas , Modelos Animais de Doenças , Técnicas In Vitro , Concentração Inibidora 50 , Leishmania/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Oxazóis/farmacologia , Pentamidina/farmacologia , Piridonas/farmacologia
4.
PLoS One ; 15(11): e0229060, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33151938

RESUMO

We assessed the virulence and anti-trypanosomal drug sensitivity patterns of Trypanosoma brucei rhodesiense (Tbr) isolates in the Kenya Agricultural and Livestock Research Organization-Biotechnology Research Institute (KALRO-BioRI) cryobank. Specifically, the study focused on Tbr clones originally isolated from the western Kenya/eastern Uganda focus of human African Trypanosomiasis (HAT). Twelve (12) Tbr clones were assessed for virulence using groups(n = 10) of Swiss White Mice monitored for 60 days post infection (dpi). Based on survival time, four classes of virulence were identified: (a) very-acute: 0-15, (b) acute: 16-30, (c) sub-acute: 31-45 and (d) chronic: 46-60 dpi. Other virulence biomarkers identified included: pre-patent period (pp), parasitaemia progression, packed cell volume (PCV) and body weight changes. The test Tbr clones together with KALRO-BioRi reference drug-resistant and drug sensitive isolates were then tested for sensitivity to melarsoprol (mel B), pentamidine, diminazene aceturate and suramin, using mice groups (n = 5) treated with single doses of each drug at 24 hours post infection. Our results showed that the clones were distributed among four classes of virulence as follows: 3/12 (very-acute), 3/12 (acute), 2/12 (sub-acute) and 4/12 (chronic) isolates. Differences in survivorship, parasitaemia progression and PCV were significant (P<0.001) and correlated. The isolate considered to be drug resistant at KALRO-BioRI, KETRI 2538, was confirmed to be resistant to melarsoprol, pentamidine and diminazene aceturate but it was not resistant to suramin. A cure rate of at least 80% was achieved for all test isolates with melarsoprol (1mg/Kg and 20 mg/kg), pentamidine (5 and 20 mg/kg), diminazene aceturate (5 mg/kg) and suramin (5 mg/kg) indicating that the isolates were not resistant to any of the drugs despite the differences in virulence. This study provides evidence of variations in virulence of Tbr clones from a single HAT focus and confirms that this variations is not a significant determinant of isolate sensitivity to anti-trypanosomal drugs.


Assuntos
Tripanossomicidas/farmacologia , Trypanosoma brucei rhodesiense/efeitos dos fármacos , Tripanossomíase Africana/tratamento farmacológico , Virulência/efeitos dos fármacos , Animais , Diminazena/análogos & derivados , Diminazena/farmacologia , Modelos Animais de Doenças , Resistência a Medicamentos/efeitos dos fármacos , Quênia , Masculino , Melarsoprol/farmacologia , Camundongos , Pentamidina/farmacologia , Suramina/farmacologia , Resultado do Tratamento , Tripanossomíase Africana/parasitologia , Uganda
5.
Elife ; 92020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32762841

RESUMO

Mutations in the Trypanosoma brucei aquaporin AQP2 are associated with resistance to pentamidine and melarsoprol. We show that TbAQP2 but not TbAQP3 was positively selected for increased pore size from a common ancestor aquaporin. We demonstrate that TbAQP2's unique architecture permits pentamidine permeation through its central pore and show how specific mutations in highly conserved motifs affect drug permeation. Introduction of key TbAQP2 amino acids into TbAQP3 renders the latter permeable to pentamidine. Molecular dynamics demonstrates that permeation by dicationic pentamidine is energetically favourable in TbAQP2, driven by the membrane potential, although aquaporins are normally strictly impermeable for ionic species. We also identify the structural determinants that make pentamidine a permeant although most other diamidine drugs are excluded. Our results have wide-ranging implications for optimising antitrypanosomal drugs and averting cross-resistance. Moreover, these new insights in aquaporin permeation may allow the pharmacological exploitation of other members of this ubiquitous gene family.


Assuntos
Aquaporina 2 , Pentamidina/farmacologia , Trypanosoma brucei brucei , Animais , Aquaporina 2/química , Aquaporina 2/genética , Aquaporina 2/metabolismo , Aquaporinas/química , Aquaporinas/genética , Aquaporinas/metabolismo , Resistência a Medicamentos/efeitos dos fármacos , Resistência a Medicamentos/genética , Melarsoprol/farmacologia , Mutação , Tripanossomicidas/farmacologia , Trypanosoma brucei brucei/efeitos dos fármacos , Trypanosoma brucei brucei/genética , Trypanosoma brucei brucei/metabolismo , Tripanossomíase Africana/tratamento farmacológico
6.
Arch Biochem Biophys ; 691: 108442, 2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-32649952

RESUMO

Metastasis-associated S100A4 protein is a small calcium-binding protein typically overexpressed in several tumor forms, and it is widely accepted that S100A4 plays a significant role in the metastasis of cancer. Tumor suppressor p53 is one of the S100A4's main targets. Previous reports show that through p53, S100A4 regulates collagen expression and cell proliferation. When S100A4 interacts with p53, the S100A4 destabilizes wild type p53. In the current study, based on 1H-15N HSQC NMR experiments and HADDOCK results, S100A4 interacts with the intrinsically unstructured transactivation domain (TAD) of the protein p53 and the pentamidine molecules in the presence of calcium ions. Our results suggest that the p53 TAD and pentamidine molecules share similar binding sites on the S100A4 protein. This observation indicates that a competitive binding mechanism can interfere with the binding of S100A4-p53 and increase the level of p53. Also, we compare different aspects of p53 activity in the WST-1 test using MCF 7 cells. We found that the presence of a pentamidine molecule results in higher p53 activity, which is also reflected in less cell proliferation. Collectively, our results indicate that disrupting the S100A4-p53 interaction would prevent cancer progression, and thus S100A4-p53 inhibitors provide a new avenue for cancer therapy.


Assuntos
Proliferação de Células/efeitos dos fármacos , Pentamidina/farmacologia , Multimerização Proteica/efeitos dos fármacos , Proteína A4 de Ligação a Cálcio da Família S100/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Sítios de Ligação , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Células MCF-7 , Pentamidina/metabolismo , Ligação Proteica , Proteína A4 de Ligação a Cálcio da Família S100/química , Proteína Supressora de Tumor p53/química
7.
Biochim Biophys Acta Biomembr ; 1862(10): 183380, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32497549

RESUMO

Latent membrane protein 1 (LMP1) is a gene product of the Epstein-Barr virus (EBV), a widely spread virus present in 90-95% of the world's population. EBV can lead to several malignancies, in which LMP1 was shown to play a key role. LMP1 is active only in the oligomeric form and its fifth transmembrane domain (TMD-5) is critical for the oligomerization, with D150 identified as a key residue for LMP1 activation. Here we propose an NMR-based approach to treat the complex oligomerization equilibria with slow conformational exchange. Using this method we investigate the TMD-5 in DPC micelles. We show that the pKa of D150 equals 7.4. Uncharged form of TMD-5 associates into dimers and trimers, deprotonation of D150 induces the high-order oligomerization of the protein and enhances dramatically its trimerization. Pentamidine interacts mainly with the charged TMD-5, destroying the oligomers and stabilizing the monomer and trimer. Using computer simulations we investigate the structural basis of TMD-5/pentamidine interaction. Our data suggest that D150 is likely charged in the full-length LMP1 under native conditions.


Assuntos
Biopolímeros/química , Pentamidina/farmacologia , Proteínas da Matriz Viral/antagonistas & inibidores , Sequência de Aminoácidos , Antivirais/farmacologia , Simulação por Computador , Soluções
8.
BMC Infect Dis ; 20(1): 400, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32503449

RESUMO

BACKGROUND: Pneumocystis carinii pneumonia (PCP) prophylaxis is recommended after hematopoietic stem cell transplantation (HSCT). In patients who are unable to take first-line prophylaxis, trimethoprim/sulfamethoxazole, aerosolized pentamidine is recommended. This drug may not, however, be available at all institutions, and its administration requires special techniques. Therefore, intravenous pentamidine (IVP) has been used in adult patients as an alternative, despite limited data. We evaluated the effectiveness and tolerability of IVP for PCP prophylaxis in adult patients who had undergone HSCT. METHODS: A single-center retrospective study was conducted of adult patients who had undergone allogenic or autologous HSCT between January 2014 and September 2018 and had received at least three doses of IVP for PCP prophylaxis. The IVP dose was 4 mg/kg administered monthly. Data on PCP infection and adverse reactions were collected from both patients' electronic medical records and the pharmacy adverse drug reactions documentation system. Patients were followed from the start of IVP up to 6 months after discontinuation of therapy. A confirmed PCP infection was defined as radiographic evidence of PCP and positive staining of a respiratory specimen. Descriptive statistics were used to analyze the study outcomes. RESULTS: During the study period, 187 patients were included. The median age was 36.4 years (range, 18-64), 58% were male, and 122 (65%) had received allogeneic HSCT while the remainder autologous HSCT. The median number of IVP doses administered per patient was 5 (range, 3-29). During the study period, none of the patients had evidence of confirmed PCP infection. However; there were two cases with high clinical suspicion of PCP infection (i.e. required anti-pneumocystis therapy) and one reported case of central nervous system toxoplasmosis while receiving IVP for PCP prophylaxis. Only one case of nausea associated with IVP administration was reported. CONCLUSIONS: In a cohort of adult patients with HSCT who received IVP for PCP prophylaxis, there was no evidence of confirmed PCP infection, and the treatment appeared to be well tolerated. Prospective studies should be conducted to confirm the efficacy and tolerability of IVP.


Assuntos
Antifúngicos/uso terapêutico , Pentamidina/uso terapêutico , Pneumonia por Pneumocystis/prevenção & controle , Adolescente , Adulto , Antifúngicos/efeitos adversos , Antifúngicos/farmacologia , Comorbidade , Feminino , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Pentamidina/efeitos adversos , Pentamidina/farmacologia , Pneumocystis carinii/efeitos dos fármacos , Pneumonia por Pneumocystis/diagnóstico , Pneumonia por Pneumocystis/microbiologia , Estudos Retrospectivos , Transplante Autólogo , Transplante Homólogo , Adulto Jovem
9.
Int Immunopharmacol ; 85: 106640, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32470884

RESUMO

The activation of proinflammatory cellular processes and signals such as those linked to NF-kB in macrophages are involved in the control of infection by Leishmania ssp. However, little is known about the influence of the drugs used in the treatment on the host cellular inflammatory signaling pathways. This study aimed to evaluate the effects of different drugs used in the treatment of leishmaniasis on inflammatory profile related to Toll-like receptors (TLRs) from L. amazonensis-infected macrophages. J774 macrophage-like cells were infected with the promastigote forms (5:1) and 24 hs incubated with Amphotericin B (AmB), Glucantime® (GLU) or Pentamidine (Pent). The following inflammatory pathways were evaluated: NF-κB p65, NF-κB p65 phosphorylated (Ser536), stress-activated protein kinase/c-Jun NH(2)-terminal kinase (SAPK/JNK) phosphorylated (Thr183/Tyr185), p38 mitogen activated protein kinase (MAPK p38) phosphorylated (Thr180/Tyr182), signal transducer and activator of transcription-3 (Stat3) phosphorylated (Tyr705) and inhibitor kappa B-α (IκB-α) phosphorylated (Ser32). In silico tests were performed to evaluate the molecular affinity between TLRs and antileishmanial drugs. Molecular docking showed that affinities varied significantly among the binders evaluated. The lowest affinity (-8.6 Kcal/Mol) was calculated for AmB in complex with TLR4. Pent showed higher values for TLR1, TLR2 and TLR3, while for TLR4 the affinity value was lower (5.5 Kcal/Mol). The values obtained for GLU were the highest for the set of binders tested. From the infected macrophages, treatments inhibited NF-kB p65 for GLU (65.44%), for Pent (46.43%) and for AmB (54.07%) compared to untreated infected macrophages. The activation of the signaling pathway of NF-kB, SAPK/JNK and IκB-α caused by AmB and Pent may potentiate the microbicidal mechanisms of the infected macrophages.


Assuntos
Antiprotozoários/farmacologia , Leishmania , Macrófagos/efeitos dos fármacos , Receptores Toll-Like/metabolismo , Anfotericina B/farmacologia , Animais , Linhagem Celular , Inflamação/imunologia , Leishmaniose/imunologia , Macrófagos/metabolismo , Antimoniato de Meglumina/farmacologia , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Simulação de Acoplamento Molecular , Pentamidina/farmacologia , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição RelA/metabolismo
10.
Eur J Clin Microbiol Infect Dis ; 39(9): 1771-1779, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32242313

RESUMO

Pentamidine sensitizes FDA-approved antibiotics to combat Gram-negative pathogens. We screened 1374 FDA-approved non-antibiotics for their ability to be sensitized by pentamidine against Escherichia coli. We identified mitomycin C and mefloquine as potent hits effective against multiple drug-resistant, Gram-negative bacteria. Killing kinetics and an in vivo model with Caenorhabditis elegans (C. elegans) revealed that such combinations produced synergy against colistin-resistant Enterobacter cloacae (E. cloacae). These findings suggest combinations of FDA-approved non-antibiotics, and pentamidine can be repurposed into new antimicrobial agents.


Assuntos
Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Pentamidina/farmacologia , Animais , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Caenorhabditis elegans/efeitos dos fármacos , Reposicionamento de Medicamentos , Farmacorresistência Bacteriana Múltipla , Sinergismo Farmacológico , Quimioterapia Combinada , Enterobacter cloacae/efeitos dos fármacos , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Modelos Animais , Pentamidina/administração & dosagem , Pentamidina/uso terapêutico , Estados Unidos , United States Food and Drug Administration
11.
Cells ; 9(3)2020 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-32197530

RESUMO

S100B is an astrocytic protein acting either as an intracellular regulator or an extracellular signaling molecule. A direct correlation between increased amount of S100B and demyelination and inflammatory processes has been demonstrated. The aim of this study is to investigate the possible role of a small molecule able to bind and inhibit S100B, pentamidine, in the modulation of disease progression in the relapsing-remitting experimental autoimmune encephalomyelitis mouse model of multiple sclerosis. By the daily evaluation of clinical scores and neuropathologic-molecular analysis performed in the central nervous system, we observed that pentamidine is able to delay the acute phase of the disease and to inhibit remission, resulting in an amelioration of clinical score when compared with untreated relapsing-remitting experimental autoimmune encephalomyelitis mice. Moreover, we observed a significant reduction of proinflammatory cytokines expression levels in the brains of treated versus untreated mice, in addition to a reduction of nitric oxide synthase activity. Immunohistochemistry confirmed that the inhibition of S100B was able to modify the neuropathology of the disease, reducing immune infiltrates and partially protecting the brain from the damage. Overall, our results indicate that pentamidine targeting the S100B protein is a novel potential drug to be considered for multiple sclerosis treatment.


Assuntos
Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/patologia , Pentamidina/uso terapêutico , Subunidade beta da Proteína Ligante de Cálcio S100/antagonistas & inibidores , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/patologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Proteína Glial Fibrilar Ácida/metabolismo , Camundongos , Esclerose Múltipla/genética , Pentamidina/farmacologia , Subunidade beta da Proteína Ligante de Cálcio S100/metabolismo
12.
Exp Parasitol ; 210: 107831, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31926147

RESUMO

Babesia (B.) bovis is one of the main etiological agents of bovine babesiosis, causes serious economic losses to the cattle industry. Control of bovine babesiosis has been hindered by the limited treatment selection for B. bovis, thus, new options are urgently needed. We explored the drug library and unbiasedly screened 640 food and drug administration (FDA) approved drug compounds for their inhibitory activities against B. bovis in vitro. The initial screening identified 13 potentially effective compounds. Four potent compounds, namely mycophenolic acid (MPA), pentamidine (PTD), doxorubicin hydrochloride (DBH) and vorinostat (SAHA) exhibited the lowest IC50 and then selected for further evaluation of their in vitro efficacies using viability, combination inhibitory and cytotoxicity assays. The half-maximal inhibitory concentration (IC50) values of MPA, PTD, DBH, SAHA were 11.38 ± 1.66, 13.12 ± 4.29, 1.79 ± 0.15 and 45.18 ± 7.37 µM, respectively. Of note, DBH exhibited IC50 lower than that calculated for the commonly used antibabesial drug, diminazene aceturate (DA). The viability result revealed the ability of MPA, PTD, DBH, SAHA to prevent the regrowth of treated parasite at 4 × and 2 × of IC50. Antagonistic interactions against B. bovis were observed after treatment with either MPA, PTD, DBH or SAHA in combination with DA. Our findings indicate the richness of FDA approved compounds by novel potent antibabesial candidates and the identified potent compounds especially DBH might be used for the treatment of animal babesiosis caused by B. bovis.


Assuntos
Antiprotozoários/farmacologia , Babesia bovis/efeitos dos fármacos , Animais , Antiprotozoários/toxicidade , Babesia bovis/crescimento & desenvolvimento , Babesiose/tratamento farmacológico , Babesiose/parasitologia , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/parasitologia , Cães , Doxorrubicina/farmacologia , Doxorrubicina/toxicidade , Aprovação de Drogas , Combinação de Medicamentos , Avaliação Pré-Clínica de Medicamentos , Ensaios de Triagem em Larga Escala , Concentração Inibidora 50 , Células Madin Darby de Rim Canino/efeitos dos fármacos , Ácido Micofenólico/farmacologia , Ácido Micofenólico/toxicidade , Pentamidina/farmacologia , Pentamidina/toxicidade , Bibliotecas de Moléculas Pequenas , Espectrometria de Fluorescência , Vorinostat/farmacologia , Vorinostat/toxicidade
13.
Cell Prolif ; 53(1): e12718, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31721355

RESUMO

OBJECTIVES: We investigated the anti-cancer activity of pentamidine, an anti-protozoal cationic aromatic diamidine drug, in prostate cancer cells and aimed to provide valuable insights for improving the efficacy of prostate cancer treatment. MATERIALS AND METHODS: Prostate cancer cell lines and epithelial RWPE-1 cells were used in the study. Cell viability, wound-healing, transwell and apoptosis assays were examined to evaluate the influences of pentamidine in vitro. RNA-seq and qPCR were performed to analyse changes in gene transcription levels upon pentamidine treatment. Mitochondrial changes were assessed by measuring mitochondrial DNA content, morphology, membrane potential, cellular glucose uptake, ATP production and ROS generation. Nude mouse xenograft models were used to test anti-tumour effects of pentamidine in vivo. RESULTS: Pentamidine exerted profound inhibitory effects on proliferation, colony formation, migration and invasion of prostate cancer cells. In addition, the drug suppressed growth of xenograft tumours without exhibiting any obvious toxicity in nude mice. Mechanistically, pentamidine caused mitochondrial DNA content reduction and induced mitochondrial morphological changes, mitochondrial membrane potential dissipation, ATP level reduction, ROS production elevation and apoptosis in prostate cancer cells. CONCLUSIONS: Pentamidine can efficiently suppress prostate cancer progression and may serve as a novel mitochondria-targeted therapeutic agent for prostate cancer.


Assuntos
Proliferação de Células/efeitos dos fármacos , DNA Mitocondrial , DNA de Neoplasias , Mitocôndrias , Pentamidina/farmacologia , Neoplasias da Próstata , Animais , Proliferação de Células/genética , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , DNA de Neoplasias/genética , DNA de Neoplasias/metabolismo , Humanos , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Potencial da Membrana Mitocondrial/genética , Camundongos , Camundongos Nus , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Células PC-3 , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Tissue Eng Regen Med ; 16(3): 265-273, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31205855

RESUMO

Background: Wear debris-induced osteolysis leads to periprosthetic loosening and subsequent prosthetic failure. Since excessive osteoclast formation is closely implicated in periprosthetic osteolysis, identification of agents to suppress osteoclast formation and/or function is crucial for the treatment and prevention of wear particle-induced bone destruction. In this study, we examined the potential effect of pentamidine treatment on titanium (Ti) particle-induced osteolysis, and receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis. Methods: The effect of pentamidine treatment on bone destruction was examined in Ti particle-induced osteolysis mouse model. Ti particles were implanted onto mouse calvaria, and vehicle or pentamidine was administered for 10 days. Then, calvarial bone tissue was analyzed using micro-computed tomography and histology. We performed in vitro osteoclastogenesis assay using bone marrow-derived macrophages (BMMs) to determine the effect of pentamidine on osteoclast formation. BMMs were treated with 20 ng/mL RANKL and 10 ng/mL macrophage colony-stimulating factor in the presence or absence of pentamidine. Osteoclast differentiation was determined by tartrate-resistant acid phosphatase staining, real-time polymerase chain reaction, and immunofluorescence staining. Results: Pentamidine administration decreased Ti particle-induced osteoclast formation significantly and prevented bone destruction compared to the Ti particle group in vivo. Pentamidine also suppressed RANKL-induced osteoclast differentiation and actin ring formation markedly, and inhibited the expression of nuclear factor of activated T cell c1 and osteoclast-specific genes in vitro. Additionally, pentamidine also attenuated RANKL-mediated phosphorylation of IκBα in BMMs. Conclusion: These results indicate that pentamidine is effective in inhibiting osteoclast formation and significantly attenuates wear debris-induced bone loss in mice.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Osteoclastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Osteólise/tratamento farmacológico , Pentamidina/farmacologia , Ligante RANK/efeitos adversos , Titânio/efeitos adversos , Animais , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Osteólise/induzido quimicamente , Pentamidina/uso terapêutico , Próteses e Implantes , Crânio/metabolismo , Crânio/patologia , Microtomografia por Raio-X
15.
Molecules ; 24(11)2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31174390

RESUMO

Pentamidine is bis-oxybenzamidine-based antiprotozoal drug. The parenteral use of pentamidine appears to affect the processes of blood coagulation and/or fibrinolysis resulting in rare but potentially life-threatening blood clot formation. Pentamidine was also found to cause disseminated intravascular coagulation syndrome. To investigate the potential underlying molecular mechanism(s) of pentamidine's effects on coagulation and fibrinolysis, we studied its effects on clotting times in normal and deficient human plasmas. Using normal plasma, pentamidine isethionate doubled the activated partial thromboplastin time at 27.5 µM, doubled the prothrombin time at 45.7 µM, and weakly doubled the thrombin time at 158.17 µM. Using plasmas deficient of factors VIIa, IXa, XIa, or XIIa, the concentrations to double the activated partial thromboplastin time were similar to that obtained using normal plasma. Pentamidine also inhibited plasmin-mediated clot lysis with half-maximal inhibitory concentration (IC50) value of ~3.6 µM. Chromogenic substrate hydrolysis assays indicated that pentamidine inhibits factor Xa and plasmin with IC50 values of 10.4 µM and 8.4 µM, respectively. Interestingly, it did not significantly inhibit thrombin, factor XIa, factor XIIIa, neutrophil elastase, or chymotrypsin at the highest concentrations tested. Michaelis-Menten kinetics and molecular modeling studies revealed that pentamidine inhibits factor Xa and plasmin in a competitive fashion. Overall, this study provides quantitative mechanistic insights into the in vitro effects of pentamidine isethionate on coagulation and fibrinolysis via the disruption of the proteolytic activity of factor Xa and plasmin.


Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Fibrinólise/efeitos dos fármacos , Pentamidina/farmacologia , Trombose/tratamento farmacológico , Testes de Coagulação Sanguínea , Fator VIIa/genética , Fator XIIa/genética , Fator XIa/genética , Fator Xa/genética , Humanos , Tempo de Tromboplastina Parcial , Tempo de Protrombina , Trombina/química , Trombina/genética , Tempo de Trombina , Trombose/sangue , Trombose/patologia
16.
Vet Parasitol ; 270: 40-46, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31213240

RESUMO

Parasitic nematodes pose a major threat to livestock production worldwide. The blood-feeding parasite Haemonchus contortus is a key small-ruminant pathogen that causes anaemia, and thereby seriously impacts animal health and production. Control of this parasite relies largely upon broad-spectrum anthelmintics, but new drugs are urgently needed to combat the threat of widespread multidrug resistance. Repurposing drugs can accelerate the development pipeline by reducing costs and risks, and can be an effective way of quickly bringing new antiparasitic drugs to market. Diarylamidine compounds such as pentamidine and diminazene have been employed in the treatment of trypanosomiasis and leishmaniasis in both human and veterinary settings, but their activity against parasitic worms has not yet been reported. We screened a small panel of diarylamidine compounds against H. contortus to assess their potential to be repurposed as anthelmintic drugs. Pentamidine and diminazene inhibited H. contortus larval development at low micromolar concentrations (IC50 4.9 µM and 16.1 µM, respectively, in a drug-susceptible isolate) with no existing cross-resistance in two multidrug resistant isolates and a monepantel-resistant isolate. Combinations of pentamidine with commercial anthelmintics showed additive activity, with no significant synergism detected. Pentamidine and diminazene showed different life-stage patterns of activity; both were active against early stage larvae in development assays, but only diminazene was active against the infective L3 stage in migration assays. This suggests some differences in uptake of the two drugs across the nematode cuticle, or differences in the nature and expression patterns of their molecular targets. As pentamidine and diminazene have been reported to be potent inhibitors of mammalian acid-sensing ion channels (ASIC), we tested the activity of known ASIC inhibitors against H. contortus to probe whether these channels may represent potential anthelmintic targets in nematodes. Remarkably, the spider-venom peptide Hi1a, a potent inhibitor of ASIC1a, inhibited H. contortus larval development with an IC50 of 22.9 ± 1.9 µM. This study highlights the potential use of diarylamidines as anthelmintics, although their activity needs to be confirmed in vivo. In addition, our demonstration that ASIC inhibitors have anthelmintic activity raises the possibility that this family of ion channels may represent a novel anthelmintic target.


Assuntos
Anti-Helmínticos/farmacologia , Diminazena/farmacologia , Haemonchus/efeitos dos fármacos , Pentamidina/farmacologia , Animais , Antiprotozoários/farmacologia , Técnicas In Vitro , Concentração Inibidora 50
17.
Exp Parasitol ; 201: 90-92, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31059693

RESUMO

Acanthamoeba are free living amoeba that have been isolated from different environments like soil, water, air dust. Moreover, they are also able to act as opportunist pathogens, mainly causing a fatal encephalitis and also keratitis in both human and animals. This study was aimed to evaluate the activity of the Medicines for Malaria Venture (MMV) compounds against the trophozoite stage of Acanthamoeba castellanii Neff. Sixteen compounds showed ≥90% inhibition of parasite growth in the initial screen (10 µM). Those set were further evaluated to determine the inhibitor concentration that inhibit the 50% of the initial population and cytotoxicity against murine macrophages. Among the compounds included in the pathogen box, pentamidine and posaconazole were the most effective against this parasite with an of IC50 of 0.567 ±â€¯0.04 and 0.630 ±â€¯0.11, respectively.


Assuntos
Acanthamoeba castellanii/efeitos dos fármacos , Amebicidas/farmacologia , Amebicidas/classificação , Animais , Linhagem Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Concentração Inibidora 50 , Camundongos , Pentamidina/farmacologia , Triazóis/farmacologia , Trofozoítos/efeitos dos fármacos
18.
J Vis Exp ; (146)2019 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-31009012

RESUMO

This method allows the separation of trypanosomes, parasites responsible for animal and human African trypanosomiasis (HAT), from infected blood. This is the best method for diagnosis of first stage HAT and furthermore this parasite purification method permits serological and research investigations. HAT is caused by Tsetse fly transmitted Trypanosoma brucei gambiense and T. b. rhodesiense. Related trypanosomes are the causative agents of animal trypanosomiasis. Trypanosome detection is essential for HAT diagnosis, treatment and follow-up. The technique described here is the most sensitive parasite detection technique, adapted to field conditions for the diagnosis of T. b. gambiense HAT and can be completed within one hour. Blood is layered onto an anion-exchanger column (DEAE cellulose) previously adjusted to pH 8, and elution buffer is added. Highly negatively charged blood cells are adsorbed onto the column whereas the less negatively charged trypanosomes pass through. Collected trypanosomes are pelleted by centrifugation and observed by microscopy. Moreover, parasites are prepared without cellular damage whilst maintaining their infectivity. Purified trypanosomes are required for immunological testing; they are used in the trypanolysis assay, the gold standard in HAT serology. Stained parasites are utilized in the card agglutination test (CATT) for field serology. Antigens from purified trypanosomes, such as variant surface glycoprotein, exoantigens, are also used in various immunoassays. The procedure described here is designed for African trypanosomes; consequently, chromatography conditions have to be adapted to each trypanosome strain, and more generally, to the blood of each species of host mammal. These fascinating pathogens are easily purified and available to use in biochemical, molecular and cell biology studies including co-culture with host cells to investigate host-parasite relationships at the level of membrane receptors, signaling, and gene expression; drug testing in vitro; investigation of gene deletion, mutation, or overexpression on metabolic processes, cytoskeletal biogenesis and parasite survival.


Assuntos
DEAE-Celulose/química , Resinas de Troca Iônica/química , Trypanosoma/isolamento & purificação , Animais , Ânions , Arginase/metabolismo , Sangue/parasitologia , Cromatografia , Feminino , Glucose/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/enzimologia , Camundongos , Pentamidina/farmacologia , Treonina/metabolismo , Trypanosoma/efeitos dos fármacos , Trypanosoma brucei brucei/efeitos dos fármacos
19.
Exp Parasitol ; 201: 57-66, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31004571

RESUMO

In the present study, we investigated the in vitro and in vivo leishmanicidal activity of synthetic compounds, containing a semicarbazone scaffold as a peptide mimetic framework. The leishmanicidal effect against amastigotes of Leishmania amazonensis was also evaluated at concentration of 100 µM-0.01 nM. The derivatives 2e, 2f, 2g and 1g, beyond the standards miltefosine and pentamidine, significantly diminished the number of L. amazonensis amastigotes in macrophages. These derivatives were also active against amastigotes of L. braziliensis. As 2g presented potent leishmanicidal activity against the amastigotes of L. amazonensis in macrophages, we also investigated the in vivo leishmanicidal activity of this compound against L. amazonensis. Approximately 105L. amazonensis promastigotes were subcutaneously inoculated into the dermis of the right ear of BALB/c mice, which were subsequently treated with 2g (p.o. or i.p.), miltefosine (p.o.) or glucantime (i.p.) at 30 µmol/kg/day x 28 days. Thus, a similar reduction in the lesion size was observed after the administration of 2g through oral (63.7 ±â€¯10.1%) and intraperitoneal (61.8 ±â€¯3.7%) routes. A larger effect was observed after treatment with miltefosine (97.7 ±â€¯0.4%), and glucantime did not exhibit activity at the dose administered. With respect to the ear parasite load, 2g diminished the number of parasites by p.o. (30.5 ±â€¯5.1%) and i.p. (33.3 ±â€¯4.3%) administration. In addition, 2g induced in vitro apoptosis, autophagy and cell cycle alterations on L. amazonensis promastigotes. In summary, the derivative 2g might represent a lead candidate for antileishmanial drugs, as this compound displayed pronounced leishmanicidal activity.


Assuntos
Antiprotozoários/uso terapêutico , Leishmania mexicana/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Semicarbazonas/uso terapêutico , Análise de Variância , Animais , Antiprotozoários/química , Antiprotozoários/farmacologia , Caspases/análise , Ciclo Celular , Linhagem Celular , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular , Feminino , Citometria de Fluxo , Concentração Inibidora 50 , Macrófagos/parasitologia , Potencial da Membrana Mitocondrial , Camundongos , Camundongos Endogâmicos BALB C , Pentamidina/química , Pentamidina/farmacologia , Pentamidina/uso terapêutico , Fosfolipídeos/metabolismo , Fosforilcolina/análogos & derivados , Fosforilcolina/química , Fosforilcolina/farmacologia , Fosforilcolina/uso terapêutico , Semicarbazonas/química , Semicarbazonas/farmacologia
20.
Exp Parasitol ; 200: 1-6, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30904692

RESUMO

Nucleoside triphosphate diphosphohydrolase (NTPDase) 1 from intracellular amastigotes of Leishmania infantum-infected macrophage was identified by immunocytochemistry and confocal laser scanning microscopy using antibodies that specifically recognize its B-domain. This enzyme was previously characterized in Leishmania promastigote form, and here it is shown to be susceptible to pentamidine isethionate (PEN). In initial assays, this antileishmanial compound (100 µM) reduced 60% phosphohydrolytic activity of promastigotes preparation. An active NTPDase 1 was then isolated by non-denaturing gel electrophoresis, and PEN (10 µM) inhibited 74% and 35% of the ATPase and ADPase activities, respectively, of this pure protein. In addition, PEN 0.1-1 µM inhibited 56% potato apyrase activity, a plant protein that shares high identity with Leishmania NTPDase 1. In contrast, amphotericin B, fluconazole, ketoconazole or allopurinol did not significantly affect phosphohydrolytic activity of either promastigotes preparation or potato apyrase. This work suggests amastigote NTPDase 1 as a new molecular target, and inhibition of its catalytic activity by pentamidine can be part of the mode of action of this drug contributing with the knowledge of its antileishmanial effect.


Assuntos
Antiprotozoários/farmacologia , Apirase/antagonistas & inibidores , Leishmania infantum/efeitos dos fármacos , Leishmania infantum/enzimologia , Pentamidina/farmacologia , Animais , Antígenos CD , Imuno-Histoquímica , Macrófagos/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Confocal
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