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1.
J Clin Invest ; 130(11): 5674-5676, 2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-32925166

RESUMO

In a stunningly short period of time, the unexpected coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has turned the unprepared world topsy-turvy. Although the rapidity with which the virus struck was indeed overwhelming, scientists throughout the world have been up to the task of deciphering the mechanisms by which SARS-CoV-2 induces the multisystem and multiorgan inflammatory responses that, collectively, contribute to the high mortality rate in affected individuals. In this issue of the JCI, Skendros and Mitsios et al. is one such team who report that the complement system plays a substantial role in creating the hyperinflammation and thrombotic microangiopathy that appear to contribute to the severity of COVID-19. In support of the hypothesis that the complement system along with neutrophils and platelets contributes to COVID-19, the authors present empirical evidence showing that treatment with the complement inhibitor compstatin Cp40 inhibited the expression of tissue factor in neutrophils. These results confirm that the complement axis plays a critical role and suggest that targeted therapy using complement inhibitors is a potential therapeutic option to treat COVID-19-induced inflammation.


Assuntos
Betacoronavirus/metabolismo , Ativação do Complemento/efeitos dos fármacos , Infecções por Coronavirus , Pandemias , Peptídeos Cíclicos/farmacologia , Pneumonia Viral , Tromboplastina/biossíntese , Microangiopatias Trombóticas , Plaquetas/metabolismo , Plaquetas/patologia , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/patologia , Humanos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/patologia , Inflamação/virologia , Neutrófilos/metabolismo , Neutrófilos/patologia , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/metabolismo , Pneumonia Viral/patologia , Índice de Gravidade de Doença , Microangiopatias Trombóticas/tratamento farmacológico , Microangiopatias Trombóticas/metabolismo , Microangiopatias Trombóticas/patologia , Microangiopatias Trombóticas/virologia
2.
J Clin Invest ; 130(11): 6151-6157, 2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-32759504

RESUMO

Emerging data indicate that complement and neutrophils contribute to the maladaptive immune response that fuels hyperinflammation and thrombotic microangiopathy, thereby increasing coronavirus 2019 (COVID-19) mortality. Here, we investigated how complement interacts with the platelet/neutrophil extracellular traps (NETs)/thrombin axis, using COVID-19 specimens, cell-based inhibition studies, and NET/human aortic endothelial cell (HAEC) cocultures. Increased plasma levels of NETs, tissue factor (TF) activity, and sC5b-9 were detected in patients. Neutrophils of patients yielded high TF expression and released NETs carrying active TF. Treatment of control neutrophils with COVID-19 platelet-rich plasma generated TF-bearing NETs that induced thrombotic activity of HAECs. Thrombin or NETosis inhibition or C5aR1 blockade attenuated platelet-mediated NET-driven thrombogenicity. COVID-19 serum induced complement activation in vitro, consistent with high complement activity in clinical samples. Complement C3 inhibition with compstatin Cp40 disrupted TF expression in neutrophils. In conclusion, we provide a mechanistic basis for a pivotal role of complement and NETs in COVID-19 immunothrombosis. This study supports strategies against severe acute respiratory syndrome coronavirus 2 that exploit complement or NETosis inhibition.


Assuntos
Betacoronavirus , Complexo de Ataque à Membrana do Sistema Complemento , Infecções por Coronavirus , Armadilhas Extracelulares , Neutrófilos , Pandemias , Pneumonia Viral , Tromboplastina , Trombose , Idoso , Betacoronavirus/imunologia , Betacoronavirus/metabolismo , Ativação do Complemento/efeitos dos fármacos , Complexo de Ataque à Membrana do Sistema Complemento/imunologia , Complexo de Ataque à Membrana do Sistema Complemento/metabolismo , Infecções por Coronavirus/sangue , Infecções por Coronavirus/imunologia , Armadilhas Extracelulares/imunologia , Armadilhas Extracelulares/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neutrófilos/imunologia , Neutrófilos/metabolismo , Peptídeos Cíclicos/farmacologia , Pneumonia Viral/sangue , Pneumonia Viral/imunologia , Receptor da Anafilatoxina C5a/antagonistas & inibidores , Receptor da Anafilatoxina C5a/sangue , Receptor da Anafilatoxina C5a/imunologia , Síndrome do Desconforto Respiratório do Adulto/sangue , Síndrome do Desconforto Respiratório do Adulto/imunologia , Síndrome do Desconforto Respiratório do Adulto/virologia , Trombina/imunologia , Trombina/metabolismo , Tromboplastina/imunologia , Tromboplastina/metabolismo , Trombose/sangue , Trombose/imunologia , Trombose/virologia
3.
Nat Commun ; 11(1): 4027, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32788676

RESUMO

Programmed cell death or apoptosis is a central biological process that is dysregulated in many diseases, including inflammatory conditions and cancer. The detection and quantification of apoptotic cells in vivo is hampered by the need for fixatives or washing steps for non-fluorogenic reagents, and by the low levels of free calcium in diseased tissues that restrict the use of annexins. In this manuscript, we report the rational design of a highly stable fluorogenic peptide (termed Apo-15) that selectively stains apoptotic cells in vitro and in vivo in a calcium-independent manner and under wash-free conditions. Furthermore, using a combination of chemical and biophysical methods, we identify phosphatidylserine as a molecular target of Apo-15. We demonstrate that Apo-15 can be used for the quantification and imaging of drug-induced apoptosis in preclinical mouse models, thus creating opportunities for assessing the in vivo efficacy of anti-inflammatory and anti-cancer therapeutics.


Assuntos
Apoptose , Imageamento Tridimensional , Peptídeos Cíclicos/farmacologia , Sequência de Aminoácidos , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Feminino , Humanos , Camundongos Endogâmicos C57BL , Microscopia de Fluorescência , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Peptídeos Cíclicos/administração & dosagem , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/química , Fagocitose/efeitos dos fármacos , Fosfatidilserinas/metabolismo
4.
Int J Food Microbiol ; 330: 108783, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-32659523

RESUMO

The contamination of Aspergillus carbonarius causes decreases and great decay of agricultural products, and threatens the human and animal health by producing mycotoxins, especially ochratoxin A. Bacillus subtilis has been proved to efficiently inhibit the growth of A. carbonarius. Revealing the major active compound and the mechanisms for the antifungal of B. subtilis are essential to enhance its antifungal activity and control the quality of antifungal products made of it. In this study, we determined that iturin A is the major compound that inhibits Aspergillus carbonarius, a widespread fungal pathogen of grape and other fruits. Iturin A significantly inhibited growth and ochratoxin A production of A. carbonarius with minimal inhibitory concentrations (MICs) of 10 µg/mL and 0.312 µg/mL, respectively. Morphological observations revealed that iturin A caused swelling of the fungal cells and thinning of the cell wall and membrane at 1/2 MIC, whereas it inhibited fungal spore germination and caused mitochondrial swelling at higher concentrations. A differential transcriptomic analysis indicated that the mechanisms used by iturin A to inhibit A. carbonarius were to downregulate the expression of genes related to cell membrane, transport, osmotic pressure, oxidation-reduction processes, and energy metabolism. Among the down-regulated genes, those related to the transport capacity were most significantly influenced, including the increase of energy-related transport pathways and decrease of other pathways. Notably, the genes related to taurine and hypotaurine metabolism were also decreased, indicating iturin A potentially cause the occurrence of osmotic imbalance in A. carbonarius, which may be the intrinsic cause for the swelling of fungal cells and mitochondria. Overall, iturin A produced by B. subtilis played important roles to inhibit A. carbonarius via changing the fungal cell structure and causing perturbations to energy, transport and osmotic pressure metabolisms in fungi. The results indicated a new direction for researches on the mechanisms for lipopeptides and provided useful information to develop more efficient antifungal agents, which are important to agriculture and biomedicine.


Assuntos
Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Aspergillus/metabolismo , Bacillus subtilis/metabolismo , Peptídeos Cíclicos/farmacologia , Antifúngicos/metabolismo , Aspergillus/genética , Aspergillus/crescimento & desenvolvimento , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/genética , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/genética , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Micotoxinas/metabolismo , Pressão Osmótica/efeitos dos fármacos , Peptídeos Cíclicos/metabolismo , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/metabolismo , Transcriptoma
5.
J Med Chem ; 63(13): 6979-6990, 2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32491863

RESUMO

We report on a cyclic peptide that inhibits matrix metalloproteinase-2 (MMP2) activation with a low-nM-level potency. This inhibitor specifically binds to the D570-A583 epitope on proMMP2 and interferes with the protein-protein interaction (PPI) between proMMP2 and tissue inhibitor of metalloproteinases-2 (TIMP2), thereby preventing the TIMP2-assisted proMMP2 activation process. We developed this cyclic peptide inhibitor through an epitope-targeted library screening process and validated its binding to proMMP2. Using a human melanoma cell line, we demonstrated the cyclic peptide's ability to modulate cellular MMP2 activities and inhibit cell migration. These results provide the first successful example of targeting the PPI between proMMP2 and TIMP2, confirming the feasibility of an MMP2 inhibition strategy that has been sought after for 2 decades.


Assuntos
Metaloproteinase 2 da Matriz/metabolismo , Peptídeos Cíclicos/farmacologia , Sequência de Aminoácidos , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Ativação Enzimática/efeitos dos fármacos , Humanos , Biblioteca de Peptídeos , Peptídeos Cíclicos/química , Ligação Proteica/efeitos dos fármacos , Relação Estrutura-Atividade , Inibidor Tecidual de Metaloproteinase-2/metabolismo
6.
J Med Chem ; 63(10): 5274-5286, 2020 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-32364733

RESUMO

The cyclic dimeric peptide 1229U91 (GR231118) has an unusual structure and displays potent, insurmountable antagonism of the Y1 receptor. To probe the structural basis for this activity, we have prepared ring size variants and heterodimeric compounds, identifying the specific residues underpinning the mechanism of 1229U91 binding. The homodimeric structure was shown to be dispensible, with analogues lacking key pharmacophoric residues in one dimer arm retaining high antagonist affinity. Compounds 11d-h also showed enhanced Y1R selectivity over Y4R compared to 1229U91.


Assuntos
Neuropeptídeos/química , Neuropeptídeos/metabolismo , Peptídeos Cíclicos/química , Peptídeos Cíclicos/metabolismo , Receptores de Neuropeptídeo Y/metabolismo , Animais , Células CHO , Cricetinae , Cricetulus , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Neuropeptídeos/farmacologia , Peptídeos Cíclicos/farmacologia , Multimerização Proteica/efeitos dos fármacos , Multimerização Proteica/fisiologia , Receptores de Neuropeptídeo Y/antagonistas & inibidores
7.
Biofouling ; 36(2): 210-221, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32292058

RESUMO

Surfactin is a type of cyclic lipopeptide biosurfactant implicated in a wide range of applications. Although its antimicrobial activity has been characterized, its effect on Candida albicans physiology remains to be elucidated. The present study evaluated the influence of surfactin-C15 (SF) and its complexes with divalent counterions on C. albicans biofilm formation and preformed biofilms. The SF and metal(II)-SF complexes inhibited biofilm formation and reduced the metabolic activity of mature biofilms in a concentration-dependent manner. The same concentrations of the compounds studied dislodged preexisting biofilms grown on polystyrene plates. Moreover, SF and its metal(II) complexes reduced the mRNA expression of hypha-specific genes HWP1, ALS1, ALS3, ECE1 and SAP4 without exhibiting significant growth inhibition. Further research showed that the compounds tested reduced cellular surface hydrophobicity (CSH). These results suggest that SF and metal(II)-SF complexes could be used as anti-biofilm agents against C. albicans hypha-related infections in clinical practice.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Complexos de Coordenação/farmacologia , Hifas/efeitos dos fármacos , Lipopeptídeos/farmacologia , Peptídeos Cíclicos/farmacologia , Tensoativos/metabolismo , Aderência Bacteriana/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida albicans/crescimento & desenvolvimento , Candida albicans/metabolismo , Proteínas Fúngicas/genética , Proteínas de Fluorescência Verde/genética , Hifas/crescimento & desenvolvimento
8.
Sci Rep ; 10(1): 4303, 2020 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-32152427

RESUMO

Single substances within complex vertebrate chemical signals could be physiologically or behaviourally active. However, the vast diversity in chemical structure, physical properties and molecular size of semiochemicals makes identifying pheromonally active compounds no easy task. Here, we identified two volatile cyclic dipeptides, cyclo(L-Leu-L-Pro) and cyclo(L-Pro-L-Pro), from the complex mixture of a chemical signal in terrestrial vertebrates (lizard genus Sceloporus), synthesised one of them and investigated their biological activity in male intra-specific communication. In a series of behavioural trials, lizards performed more chemosensory behaviour (tongue flicks, lip smacks and substrate lickings) when presented with the synthesised cyclo(L-Pro-L-Pro) chemical blend, compared to the controls, the cyclo(L-Leu-L-Pro) blend, or a combined blend with both cyclic dipeptides. The results suggest a potential semiochemical role of cyclo(L-Pro-L-Pro) and a modulating effect of cyclo(L-Leu-L-Pro) that may depend on the relative concentration of both compounds in the chemical signal. In addition, our results stress how minor compounds in complex mixtures can produce a meaningful behavioural response, how small differences in structural design are crucial for biological activity, and highlight the need for more studies to determine the complete functional landscape of biologically relevant compounds.


Assuntos
Comportamento Animal/efeitos dos fármacos , Quimiotaxia , Dipeptídeos/farmacologia , Glândulas Exócrinas/metabolismo , Peptídeos Cíclicos/farmacologia , Compostos Orgânicos Voláteis/farmacologia , Animais , Dipeptídeos/química , Glândulas Exócrinas/efeitos dos fármacos , Lagartos , Peptídeos Cíclicos/química , Compostos Orgânicos Voláteis/química
9.
Chem Commun (Camb) ; 56(26): 3741-3744, 2020 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-32124910

RESUMO

Continuous efforts have been invested in the selective modification of proteins. Herein, we first report the construction of sulfonium tethered cyclic peptides via an intramolecular cyclization by an aliphatic halide. This cyclization could enhance the stability and cellular uptake of peptides. Furthermore, the sulfonium center could be recognized by cysteine in the vicinity of the protein-peptide interacting interface and form a peptide-protein conjugate.


Assuntos
Metionina/química , Peptídeos Cíclicos/química , Compostos de Sulfônio/química , Alquilação , Transporte Biológico , Ciclização , Células HeLa , Humanos , Peptídeos Cíclicos/farmacologia
10.
Pharmacol Rep ; 72(2): 314-321, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32125684

RESUMO

BACKGROUND: Irritable bowel syndrome (IBS) is a chronic condition with recurring gastrointestinal (GI) symptoms: altered motility and abdominal pain. As endogenous opioid system participates in pain perception and in the control of GI peristalsis, opioids have been proposed as a promising therapy in IBS. In a previous study, we observed that morphiceptin derivative, P-317 (Dmt-cyclo-(D-Lys-Phe-D-Pro-Asp)-NH2), presents promising features to be applied in IBS. In this project, we tested whether modifications in cyclic morphiceptin-based structure: fluorination (compound 1) or peptide bond reduction (compound 2) improve pharmacological effect. METHODS: We evaluated tested derivatives in the mouse GI system under physiological (GI transit) and pathophysiological (castor oil diarrhea, stress-induced hypermotility, visceral pain) conditions. RESULTS: Both compounds prolonged GI transit. Compound 1 and P-317 inhibited upper GI transit and motility of the colon; compound 2 remained inactive. Compound 1 and P-317 inhibited hypermotility in stressed mice and delayed the acute diarrhea in comparison to control. Only P-317 exerted antinociceptive effect. None of tested derivatives, similar to P-317, affected locomotor activity. CONCLUSIONS: Compound 1 is equally effective as P-317 in the mouse GI tract. The peptide bond reduction decreased the activity of compound 2. Fluorination appears to be an efficient way to increase the effects of morphiceptin analogs in the GI tract.


Assuntos
Dor Abdominal/tratamento farmacológico , Endorfinas/farmacologia , Trato Gastrointestinal/efeitos dos fármacos , Trânsito Gastrointestinal/efeitos dos fármacos , Peptídeos Cíclicos/farmacologia , Dor Abdominal/fisiopatologia , Animais , Endorfinas/química , Injeções Intraperitoneais , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Peptídeos Cíclicos/química , Relação Estrutura-Atividade
11.
Int J Oncol ; 56(3): 848-856, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32124968

RESUMO

Squamous cell lung carcinoma (SQCLC) is an aggressive type of lung cancer. In contrast with the marked advances that have been achieved in the treatment of lung adenocarcinoma, there are currently no effective targeted therapies for SQCLC, for with cytotoxic drugs are still the main treatment strategy. Therefore, the present study aimed to develop novel combination therapies for SQCLC. The results demonstrated that a combined treatment with the potent histone deacetylase (HDAC) inhibitor OBP­801 and the third­generation anthracycline amrubicin synergistically inhibited the viability of SQCLC cell lines by inducing apoptosis signal­regulating kinase 1 (ASK1)­dependent, as well as JNK­ and p38 mitogen­activated protein kinase (MAPK)­independent apoptosis. OBP­801 treatment strongly induced the protein expression levels of thioredoxin­interacting protein (TXNIP), and amrubicin treatment increased the levels of intracellular reactive oxygen species (ROS), which suggested that this combination oxidized and dissociated thioredoxin 2 (Trx2) from mitochondrial ASK1 and activated ASK1. Moreover, mouse xenograft experiments using human H520 SQCLC cells revealed that the co­treatment potently suppressed tumor growth in vivo. These results suggested that a combined treatment with OBP­801 and amrubicin may have potential as a therapeutic strategy for SQCLC.


Assuntos
Antraciclinas/administração & dosagem , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Inibidores de Histona Desacetilases/administração & dosagem , Neoplasias Pulmonares/tratamento farmacológico , MAP Quinase Quinase Quinase 5/metabolismo , Peptídeos Cíclicos/administração & dosagem , Animais , Antraciclinas/farmacologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Inibidores de Histona Desacetilases/farmacologia , Humanos , Neoplasias Pulmonares/metabolismo , Camundongos , Peptídeos Cíclicos/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
12.
PLoS One ; 15(3): e0229761, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32155179

RESUMO

Cyclo-Gly-Pro (CGP) attenuates nociception, however its effects on salivary glands remain unclear. In this study, we investigated the acute effects of CGP on salivary flow and composition, and on the submandibular gland composition, compared with morphine. Besides, we characterized the effects of naloxone (a non-selective opioid receptor antagonist) on CGP- and morphine-induced salivary and glandular alterations in mice. After that, in silico analyses were performed to predict the interaction between CGP and opioid receptors. Morphine and CGP significantly reduced salivary flow and total protein concentration of saliva and naloxone restored them to the physiological levels. Morphine and CGP also reduced several infrared vibrational modes (Amide I, 1687-1594cm-1; Amide II, 1594-1494cm-1; CH2/CH3, 1488-1433cm-1; C = O, 1432-1365cm-1; PO2 asymmetric, 1290-1185cm-1; PO2 symmetric, 1135-999cm-1) and naloxone reverted these alterations. The in silico docking analysis demonstrated the interaction of polar contacts between the CGP and opioid receptor Cys219 residue. Altogether, we showed that salivary hypofunction and glandular changes elicited by CGP may occur through opioid receptor suggesting that the blockage of opioid receptors in superior cervical and submandibular ganglions may be a possible strategy to restore salivary secretion while maintaining antinociceptive action due its effects on the central nervous system.


Assuntos
Gânglios Parassimpáticos/efeitos dos fármacos , Naloxona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Peptídeos Cíclicos/farmacologia , Glândulas Salivares/efeitos dos fármacos , Analgésicos Opioides/farmacologia , Animais , Sítios de Ligação , Gânglios Parassimpáticos/metabolismo , Gânglios Parassimpáticos/fisiologia , Masculino , Camundongos , Morfina/farmacologia , Nociceptividade , Ligação Proteica , Receptores Opioides/química , Receptores Opioides/metabolismo , Saliva/metabolismo , Glândulas Salivares/metabolismo , Glândulas Salivares/fisiologia
13.
Planta ; 251(3): 70, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32086615

RESUMO

MAIN CONCLUSION: Lipopeptides could help to overcome a large concern in agriculture: resistance against chemical pesticides. These molecules have activity against various phytopathogens and a potential to be transformed by genetic engineering. The exponential rise of pest resistances to different chemical pesticides and the global appeal of consumers for a sustainable agriculture and healthy nutrition have led to the search of new solutions for pest control. Furthermore, new laws require a different stance of producers. Based on that, bacteria of the genus Bacillus present a great agricultural potential, producing lipopeptides (LPs) that have high activity against insects, mites, nematodes, and/or phytopathogens that are harmful to plant cultures. Biopesticide activity can be found mainly in three families of Bacillus lipopeptides: surfactin, iturin, and fengycin. These molecules have an amphiphilic nature, interfering with biological membrane structures. Their antimicrobial properties include activity against bacteria, fungi, oomycetes, and viruses. Recent studies also highlight the ability of these compounds to stimulate defense mechanisms of plants and biofilm formation, which is a key factor for the successful colonization of biocontrol organisms. The use of molecular biology has also recently been researched for continuous advances and discoveries of new LPs, avoiding possible future problems of resistance against these molecules. As a consequence of the properties and possibilities of LPs, numerous studies and developments as well as the attention of large companies in the field is expected in the near future.


Assuntos
Agricultura , Bacillus/metabolismo , Lipopeptídeos/farmacologia , Controle Biológico de Vetores/métodos , Animais , Anti-Infecciosos/farmacologia , Antifúngicos/farmacologia , Bactérias/efeitos dos fármacos , Resistência a Medicamentos , Fungos/efeitos dos fármacos , Insetos/efeitos dos fármacos , Lipopeptídeos/química , Lipopeptídeos/metabolismo , Ácaros/efeitos dos fármacos , Nematoides/efeitos dos fármacos , Peptídeos Cíclicos/farmacologia , Praguicidas/farmacologia , Doenças das Plantas/prevenção & controle , Plantas/microbiologia , Vírus/efeitos dos fármacos
14.
Molecules ; 25(4)2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32069902

RESUMO

Antimicrobial resistance to conventional antibiotics and the limited alternatives to combat plant-threatening pathogens are worldwide problems. Antibiotic lipopeptides exert remarkable membrane activity, which usually is not prone to fast resistance formation, and often show organism-type selectivity. Additional modes of action commonly complement the bioactivity profiles of such compounds. The present work describes a multicomponent-based methodology for the synthesis of cyclic polycationic lipopeptides with stabilized helical structures. The protocol comprises an on solid support Ugi-4-component macrocyclization in the presence of a lipidic isocyanide. Circular dichroism was employed to study the influence of both macrocyclization and lipidation on the amphiphilic helical structure in water and micellar media. First bioactivity studies against model phytopathogens demonstrated a positive effect of the lipidation on the antimicrobial activity.


Assuntos
Antifúngicos/química , Lactamas/química , Lipopeptídeos/química , Peptídeos Cíclicos/química , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Antifúngicos/síntese química , Antifúngicos/farmacologia , Botrytis/efeitos dos fármacos , Lipopeptídeos/síntese química , Lipopeptídeos/farmacologia , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/farmacologia , Phytophthora infestans/efeitos dos fármacos
15.
Molecules ; 25(4)2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32093030

RESUMO

As opposed to small molecules, macrocyclic peptides possess a large surface area and are recognised as promising candidates to selectively treat diseases by disrupting specific protein-protein interactions (PPIs). Due to the difficulty in predicting cyclopeptide conformations in solution, the de novo design of bioactive cyclopeptides remains significantly challenging. In this study, we used the combination of conformational analyses and molecular docking studies to design a new cyclopeptide inhibitor of the interaction between the human tumour necrosis factor alpha (TNFα) and its receptor TNFR-1. This interaction is a key in mediating the inflammatory response to tissue injury and infection in humans, and it is also an important causative factor of rheumatoid arthritis, psoriasis and inflammatory bowel disease. The solution state NMR structure of the cyclopeptide was determined, which helped to deduce its mode of interaction with TNFα. TNFα sensor cells were used to evaluate the biological activity of the peptide.


Assuntos
Desenho de Fármacos , Peptídeos Cíclicos , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Células HEK293 , Humanos , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/química , Peptídeos Cíclicos/farmacologia , Estrutura Secundária de Proteína , Relação Estrutura-Atividade
16.
Nature ; 578(7796): 582-587, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32051588

RESUMO

Addressing the ongoing antibiotic crisis requires the discovery of compounds with novel mechanisms of action that are capable of treating drug-resistant infections1. Many antibiotics are sourced from specialized metabolites produced by bacteria, particularly those of the Actinomycetes family2. Although actinomycete extracts have traditionally been screened using activity-based platforms, this approach has become unfavourable owing to the frequent rediscovery of known compounds. Genome sequencing of actinomycetes reveals an untapped reservoir of biosynthetic gene clusters, but prioritization is required to predict which gene clusters may yield promising new chemical matter2. Here we make use of the phylogeny of biosynthetic genes along with the lack of known resistance determinants to predict divergent members of the glycopeptide family of antibiotics that are likely to possess new biological activities. Using these predictions, we uncovered two members of a new functional class of glycopeptide antibiotics-the known glycopeptide antibiotic complestatin and a newly discovered compound we call corbomycin-that have a novel mode of action. We show that by binding to peptidoglycan, complestatin and corbomycin block the action of autolysins-essential peptidoglycan hydrolases that are required for remodelling of the cell wall during growth. Corbomycin and complestatin have low levels of resistance development and are effective in reducing bacterial burden in a mouse model of skin MRSA infection.


Assuntos
Antibacterianos , Descoberta de Drogas , Peptídeos Cíclicos , Peptidoglicano/efeitos dos fármacos , Peptidoglicano/metabolismo , Actinobacteria/química , Actinobacteria/genética , Actinobacteria/metabolismo , Animais , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Vias Biossintéticas/genética , Parede Celular/metabolismo , Clorofenóis/química , Clorofenóis/metabolismo , Clorofenóis/farmacologia , Modelos Animais de Doenças , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Resistência Microbiana a Medicamentos/genética , Feminino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Testes de Sensibilidade Microbiana , Família Multigênica , N-Acetil-Muramil-L-Alanina Amidase/antagonistas & inibidores , Peptídeos Cíclicos/química , Peptídeos Cíclicos/metabolismo , Peptídeos Cíclicos/farmacologia , Filogenia , Pele/microbiologia , Infecções Estafilocócicas/microbiologia
17.
J Med Chem ; 63(7): 3475-3484, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32003561

RESUMO

Tachyplesin I (TPI) is a cationic ß-hairpin antimicrobial peptide with broad-spectrum, potent antimicrobial activity. In this study, the all d-amino acid analogue of TPI (TPAD) was synthesized, and its structure and activity were determined. TPAD has comparable antibacterial activity to TPI on 14 bacterial strains, including four drug-resistant bacteria. Importantly, TPAD has significantly improved stability against enzymatic degradation and decreased hemolytic activity compared to TPI, indicating that it has better therapeutic potential. The induction of bacterial resistance using low concentrations of TPAD resulted in the activation of the QseC/B two-component system. Deletion of this system resulted in at least five-fold improvement of TPAD activity, and the combined use of TPAD with LED209, a QseC/B inhibitor, significantly enhanced the bactericidal effect against three classes of multidrug-resistant bacteria.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias/efeitos dos fármacos , Proteínas de Ligação a DNA/farmacologia , Peptídeos Cíclicos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Sequência de Aminoácidos , Antibacterianos/síntese química , Peptídeos Catiônicos Antimicrobianos/síntese química , Proteínas de Bactérias/metabolismo , Linhagem Celular , Membrana Celular/metabolismo , Proteínas de Ligação a DNA/síntese química , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Estabilidade de Medicamentos , Sinergismo Farmacológico , Humanos , Masculino , Testes de Sensibilidade Microbiana , Simulação de Dinâmica Molecular , Peptídeos Cíclicos/síntese química , Estereoisomerismo , Sulfonamidas/farmacologia
18.
Nucleic Acids Res ; 48(7): 3496-3512, 2020 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-32107550

RESUMO

Aberrant Notch signaling plays a pivotal role in T-cell acute lymphoblastic leukemia (T-ALL) and chronic lymphocytic leukemia (CLL). Amplitude and duration of the Notch response is controlled by ubiquitin-dependent proteasomal degradation of the Notch1 intracellular domain (NICD1), a hallmark of the leukemogenic process. Here, we show that HDAC3 controls NICD1 acetylation levels directly affecting NICD1 protein stability. Either genetic loss-of-function of HDAC3 or nanomolar concentrations of HDAC inhibitor apicidin lead to downregulation of Notch target genes accompanied by a local reduction of histone acetylation. Importantly, an HDAC3-insensitive NICD1 mutant is more stable but biologically less active. Collectively, these data show a new HDAC3- and acetylation-dependent mechanism that may be exploited to treat Notch1-dependent leukemias.


Assuntos
Histona Desacetilases/metabolismo , Leucemia/metabolismo , Receptor Notch1/metabolismo , Transdução de Sinais , Animais , Linhagem Celular , Linhagem Celular Tumoral , Inibidores de Histona Desacetilases/farmacologia , Humanos , Leucemia/enzimologia , Lisina/metabolismo , Camundongos , Mutação , Peptídeos Cíclicos/farmacologia , Estabilidade Proteica , Receptor Notch1/química , Receptor Notch1/genética
19.
Biochim Biophys Acta Proteins Proteom ; 1868(5): 140378, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32032759

RESUMO

Amyloidogenic disorders are currently rising as a global health issue, prompting more and more studies dedicated to the development of effective targeted therapeutics. The innate affinity of these amyloidogenic proteins towards the biomembranes adds further complexities to the systems. Our previous studies have shown that biologically active peptides can effectively target amyloidogenesis serving as an efficient therapeutic alternative in several amyloidogenic disorders. The structural uniqueness of the PWWP motif in the de novo designed heptapeptide, KR7 (KPWWPRR-NH2) was demonstrated to target insulin fiber elongation specifically. By working on insulin, an important model system in amyloidogenic studies, we gained several mechanistic insights into the inhibitory actions at the protein-peptide interface. Here, we report a second-generation non-toxic and serum stable cyclic peptide, based primarily on the PWWP motif that resulted in complete inhibition of insulin fibrillation both in the presence and absence of the model membranes. Using both low- and high-resolution spectroscopic techniques, we could delineate the specific mechanism of inhibition, at atomistic resolution. Our studies put forward an effective therapeutic intervention that redirects the default aggregation kinetics towards off-pathway fibrillation. Based on the promising results, this novel cyclic peptide can be considered an excellent lead to design pharmaceutical molecules against amyloidogenesis.


Assuntos
Amiloide/química , Insulina/química , Peptídeos Cíclicos/farmacologia , Peptídeos Cíclicos/química , Multimerização Proteica/efeitos dos fármacos
20.
J Biol Chem ; 295(9): 2866-2884, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-31959628

RESUMO

Aberrant Ras signaling drives 30% of cancers, and inhibition of the Rho family small GTPase signaling has been shown to combat Ras-driven cancers. Here, we present the discovery of a 16-mer cyclic peptide that binds to Cdc42 with nanomolar affinity. Affinity maturation of this sequence has produced a panel of derived candidates with increased affinity and modulated specificity for other closely-related small GTPases. The structure of the tightest binding peptide was solved by NMR, and its binding site on Cdc42 was determined. Addition of a cell-penetrating sequence allowed the peptides to access the cell interior and engage with their target(s), modulating signaling pathways. In Ras-driven cancer cell models, the peptides have an inhibitory effect on proliferation and show suppression of both invasion and motility. As such, they represent promising candidates for Rho-family small GTPase inhibitors and therapeutics targeting Ras-driven cancers. Our data add to the growing literature demonstrating that peptides are establishing their place in the biologics arm of drug discovery.


Assuntos
Descoberta de Drogas , Peptídeos Cíclicos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Proteína cdc42 de Ligação ao GTP/antagonistas & inibidores , Proteínas ras/metabolismo , Sítios de Ligação , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Peptídeos Penetradores de Células , GTP Fosfo-Hidrolases/antagonistas & inibidores , Humanos , Estrutura Molecular , Invasividade Neoplásica/prevenção & controle , Neoplasias/tratamento farmacológico , Peptídeos Cíclicos/química , Peptídeos Cíclicos/metabolismo , Proteína cdc42 de Ligação ao GTP/metabolismo
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