RESUMO
Cecropins are a family of antimicrobial peptides (AMPs) that are widely found in the innate immune system of Cecropia moths. Cecropins exhibit a broad spectrum of antimicrobial and anticancer activities. The structures of Cecropins are composed of 34-39 amino acids with an N-terminal amphipathic α-helix, an AGP hinge and a hydrophobic C-terminal α-helix. KR12AGPWR6 was designed based on the Cecropin-like structural feature. In addition to its antimicrobial activities, KR12AGPWR6 also possesses enhanced salt resistance, antiendotoxin and anticancer properties. Herein, we have developed a strategy to produce recombinant KR12AGPWR6 through a salt-sensitive, pH and temperature dependent intein self-cleavage system. The His6-Intein-KR12AGPWR6 was expressed by E. coli and KR12AGPWR6 was released by the self-cleavage of intein under optimized ionic strength, pH and temperature conditions. The molecular weight and structural feature of the recombinant KR12AGPWR6 was determined by MALDI-TOF mass, CD, and NMR spectroscopy. The recombinant KR12AGPWR6 exhibited similar antimicrobial activities compared to the chemically synthesized KR12AGPWR6. Our results provide a potential strategy to obtain large quantities of AMPs and this method is feasible and easy to scale up for commercial production.
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There is an urgent and imminent need to develop new agents to fight against cancer. In addition to the antimicrobial and anti-inflammatory activities, many antimicrobial peptides can bind to and lyse cancer cells. P-113, a 12-amino acid clinically active histatin-rich peptide, was found to possess anti-Candida activities but showed poor anticancer activity. Herein, anticancer activities and induced immunogenic cancer cell death of phenylalanine-(Phe-P-113), ß-naphthylalanine-(Nal-P-113), ß-diphenylalanine-(Dip-P-113), and ß-(4,4'-biphenyl)alanine-(Bip-P-113) substituted P-113 were studied. Among these peptides, Nal-P-113 demonstrated the best anticancer activity and caused cancer cells to release potent danger-associated molecular patterns (DAMPs), such as reactive oxygen species (ROS), cytochrome c, ATP, and high-mobility group box 1 (HMGB1). These results could help in developing antimicrobial peptides with better anticancer activity and induced immunogenic cell death in therapeutic applications.
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The global spread of antibiotic-resistant infections has meant that there is an urgent need to develop new antimicrobial alternatives. In this study, we developed a strategy to boost and/or synergize the activity of conventional antibiotics by combination with antimicrobial peptides tagged with the bulky non-natural amino acid ß-naphthylalanine (Nal) to their N- or C-terminus. A checkerboard method was used to evaluate synergistic effects of the parent peptide and the Nal-tagged peptides. Moreover, boron-dipyrro-methene labeled vancomycin was used to characterize the synergistic mechanism of action between the peptides and vancomycin on the bacterial strains. These Nal-tagged antimicrobial peptides also reduced the antibiotic-induced release of lipopolysaccharide from Gram-negative bacteria by more than 99.95%. Our results demonstrate that Nal-tagged peptides could help in developing antimicrobial peptides that not only have enhanced antibacterial activities but also increase the synergistic effects with conventional antibiotics against antibiotic-resistant bacteria.
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There is an urgent and imminent need to develop new antimicrobials to fight against antibiotic-resistant bacterial and fungal strains. In this study, a checkerboard method was used to evaluate the synergistic effects of the antimicrobial peptide P-113 and its bulky non-nature amino acid substituted derivatives with vancomycin against vancomycin-resistant Enterococcus faecium, Staphylococcus aureus, and wild-type Escherichia coli. Boron-dipyrro-methene (BODIPY) labeled vancomycin was used to characterize the interactions between the peptides, vancomycin, and bacterial strains. Moreover, neutralization of antibiotic-induced releasing of lipopolysaccharide (LPS) from E. coli by the peptides was obtained. Among these peptides, Bip-P-113 demonstrated the best minimal inhibitory concentrations (MICs), antibiotics synergism, bacterial membrane permeabilization, and supernatant LPS neutralizing activities against the bacteria studied. These results could help in developing antimicrobial peptides that have synergistic activity with large size glycopeptides such as vancomycin in therapeutic applications.
Assuntos
Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Sinergismo Farmacológico , Enterococcus faecium/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Proteínas Citotóxicas Formadoras de Poros/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Vancomicina/farmacologia , Antibacterianos/farmacologia , Testes de Sensibilidade MicrobianaRESUMO
In the absence of proper immunity, such as in the case of acquired immune deficiency syndrome (AIDS) patients, Candida albicans, the most common human fungal pathogen, may cause mucosal and even life-threatening systemic infections. P-113 (AKRHHGYKRKFH), an antimicrobial peptide (AMP) derived from the human salivary protein histatin 5, shows good safety and efficacy profiles in gingivitis and human immunodeficiency virus (HIV) patients with oral candidiasis. However, little is known about how P-113 interacts with Candida albicans or its degradation by Candida-secreted proteases that contribute to the fungi's resistance. Here, we use solution nuclear magnetic resonance (NMR) methods to elucidate the molecular mechanism of interactions between P-113 and living Candida albicans cells. Furthermore, we found that proteolytic cleavage of the C-terminus prevents the entry of P-113 into cells and that increasing the hydrophobicity of the peptide can significantly increase its antifungal activity. These results could help in the design of novel antimicrobial peptides that have enhanced stability in vivo and that can have potential therapeutic applications.
Assuntos
Antifúngicos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Candida albicans/efeitos dos fármacos , Farmacorresistência Fúngica/efeitos dos fármacos , Sequência de Aminoácidos , Antifúngicos/química , Peptídeos Catiônicos Antimicrobianos/química , Candida albicans/ultraestrutura , Relação Dose-Resposta a Droga , Histatinas/química , Humanos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Proteólise , Fatores de TempoRESUMO
Neurofilaments: light, medium, and heavy (abbreviated as NF-L, NF-M, and NF-H, respectively), which belong to Type IV intermediate filament family (IF), are neuron-specific cytoskeletal components. Neurofilaments are axonal structural components and integral components of synapses, which are important for neuronal electric signal transmissions along the axons and post-translational modification. Abnormal assembly of neurofilaments is found in several human neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), infantile spinal muscular atrophy (SMA), and hereditary sensory-motor neuropathy (HSMN). In addition, those pathological neurofilament accumulations are known in α-synuclein in Parkinson's disease (PD), Aß and tau in Alzheimer's disease (AD), polyglutamine in CAG trinucleotide repeat disorders, superoxide dismutase 1 (SOD1), TAR DNA-binding protein 43 (TDP43), neuronal FUS proteins, optineurin (OPTN), ubiquilin 2 (UBQLN2), and dipeptide repeat protein (DRP) in amyotrophic lateral sclerosis (ALS). When axon damage occurs in central nervous disorders, neurofilament proteins are released and delivered into cerebrospinal fluid (CSF), which are then circulated into blood. New quantitative analyses and assay techniques are well-developed for the detection of neurofilament proteins, particularly NF-L and the phosphorylated NF-H (pNF-H) in CSF and serum. This review discusses the potential of using peripheral blood NF quantities and evaluating the severity of damage in the nervous system. Intermediate filaments could be promising biomarkers for evaluating disease progression in different nervous system disorders.
Assuntos
Doenças Neurodegenerativas/diagnóstico , Proteínas de Neurofilamentos/sangue , Biomarcadores/sangue , Humanos , PrognósticoRESUMO
Oligomerization of protein into specific quaternary structures plays important biological functions, including regulation of gene expression, enzymes activity, and cell-cell interactions. Here, we report the determination of two crystal structures of the Grimontia hollisae (formally described as Vibrio hollisae) thermostable direct hemolysin (Gh-TDH), a pore-forming toxin. The toxin crystalized in the same space group of P21212, but with two different crystal packing patterns, each revealing three consistent tetrameric oligomerization forms called Oligomer-I, -II, and -III. A central pore with comparable depth of ~50 Å but differing in shape and size was observed in all determined toxin tetrameric oligomers. A common motif of a toxin dimer was found in all determined structures, suggesting a plausible minimum functional unit within the tetrameric structure in cell membrane binding and possible hemolytic activity. Our results show that bacterial toxins may form a single or highly symmetric oligomerization state when exerting their biological functions. The dynamic nature of multiple symmetric oligomers formed upon release of the toxin may open a niche for bacteria survival in harsh living environments.
Assuntos
Membrana Celular/metabolismo , Proteínas Hemolisinas/química , Proteínas Hemolisinas/metabolismo , Vibrionaceae/metabolismo , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/química , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Cristalografia por Raios X , Células HeLa , Proteínas Hemolisinas/genética , Hemólise , Humanos , Modelos Moleculares , Mutagênese Sítio-Dirigida , Ligação Proteica , Multimerização Proteica , Estrutura Quaternária de Proteína , Coelhos , Vibrionaceae/química , Vibrionaceae/genéticaRESUMO
HYPOTHESIS: Release of lipopolysaccharides (LPS) from bacteria into bloodstream may cause serious unwanted stimulation of the host immune system. P-113 is a clinically active histidine-rich antimicrobial peptide. Nal-P-113, a ß-naphthylalanine-substituted P-113, is salt-resistant but has limited LPS neutralizing activity. We suspected the size and shape of the non-natural bulky amino acid may affect its LPS neutralizing activity. Herein, antimicrobial, LPS neutralizing, and antiproteolytic effects of phenylalanine- (Phe-P-113), ß-naphthylalanine- (Nal-P-113), ß-diphenylalanine- (Dip-P-113), and ß-(4,4'-biphenyl)alanine- (Bip-P-113) substituted P-113 were studied. EXPERIMENTS: Structure-activity relationships of P-113, Phe-P-113, Nal-P-113, Dip-P-113, and Bip-P-113 were evaluated using antimicrobial activity assays, serum proteolytic assays, peptide-induced permeabilization of large unilamellar vesicles, zeta potential measurements, dynamic light scattering measurement of LPS aggregation, and Limulus amebocyte lysate assays for measuring LPS neutralization. In vitro and in vivo LPS neutralizing activities were further confirmed by LPS-induced inflammation inhibition in an endotoxemia mouse model. FINDINGS: Bip-P-113 and Dip-P-113 had the longest and widest non-nature amino acids, respectively. Bip-P-113 enhanced salt resistance, serum proteolytic stability, peptide-induced permeabilization, zeta potential measurements, LPS aggregation, and in vitro and in vivo LPS neutralizing activities. These results could help design novel antimicrobial peptides that have enhanced stability in vivo and that can have potential therapeutic applications.
Assuntos
Aminoácidos/química , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Endotoxemia/tratamento farmacológico , Inflamação/tratamento farmacológico , Lipopolissacarídeos/antagonistas & inibidores , Animais , Antibacterianos/sangue , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/sangue , Peptídeos Catiônicos Antimicrobianos/química , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Difusão Dinâmica da Luz , Endotoxemia/induzido quimicamente , Endotoxinas , Escherichia coli/efeitos dos fármacos , Fibroblastos , Técnica de Placa Hemolítica , Humanos , Inflamação/induzido quimicamente , Lipopolissacarídeos/química , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Relação Estrutura-Atividade , Propriedades de SuperfícieRESUMO
P-113, which was originally derived from the human saliva protein histatin 5, is a histidine-rich antimicrobial peptide with the sequence AKRHHGYKRKFH. P-113 is currently undergoing phase II clinical trial as a pharmaceutical agent to fight against fungal infections in HIV patients with oral candidiasis. Previously, we developed a new procedure for the high-yield expression and purification of hG31P, an analogue and antagonist of human CXCL8. Moreover, we have successfully removed lipopolysaccharide (LPS, endotoxin) associated with hG31P in the expression with Escherichia coli. In this paper, we have used hG31P as a novel fusion protein for the expression and purification of P-113. The purity of the expressed P-113 is more than 95% and the yield is 4 mg P-113 per liter of E. coli cell culture in Luria-Bertani (LB) medium. The antimicrobial activity of the purified P-113 was tested. Furthermore, we used circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy to study the structural properties of P-113. Our results indicate that using hG31P as a fusion protein to obtain large quantities of P-113 is feasible and is easy to scale up for commercial production. An effective way of producing enough P-113 for future clinical studies is evident in this study.
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Peptídeos Catiônicos Antimicrobianos , Escherichia coli , Expressão Gênica , Histatinas , Peptídeos Catiônicos Antimicrobianos/biossíntese , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Histatinas/biossíntese , Histatinas/genética , Histatinas/isolamento & purificação , Humanos , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/isolamento & purificaçãoRESUMO
The growing number of zika virus (ZIKV) infections plus a 20-fold increase in neonatal microcephaly in newborns in Brazil have raised alarms in many countries regarding the threat to pregnant women. Instances of microcephaly and central nervous system malformations continue to increase in ZIKV outbreak regions. ZIKV is a small enveloped positive-strand RNA virus belonging to the Flavivirus genus of the Flaviviridae family. High-resolution ZIKV structures recently identified by cryo-electron microscopy indicate that the overall ZIKV structure is similar to those of other flaviviruses. With its compact surface, ZIKV is more thermally stable than the dengue virus (DENV). ZIKV E proteins have a characteristic "herringbone" structure with a single glycosylation site. The ZIKV E protein, the major protein involved in receptor binding and fusion, is formed as a head-to-tail dimer on the surfaces of viral particles. The E monomer consists of three distinct domains: DI, DII, and DIII. The finger-like DII contains a fusion loop (FL) that is inserted into the host cell endosomal membrane during pH-dependent conformational changes that drive fusion. Quaternary E:E dimer epitopes located at the interaction site of prM and E dimers can be further divided into two dimer epitopes. To date, more than 50 ZIKV vaccine candidates are now in various stages of research and development. Candidate ZIKV vaccines that are currently in phase I/II clinical trials include inactivated whole viruses, recombinant measles viral vector-based vaccines, DNA and mRNA vaccines, and a mosquito salivary peptide vaccine. Stabilized forms of ZIKV E:E dimer proteins have been successfully obtained either by introducing additional inter-subunit disulfide bond(s) in DII or via the direct assembly of E:E dimer proteins by immobilization with monomeric E proteins. The VLP-based approach is another alternative method for presenting native E:E dimer antigens among the vaccine components. Several forms of ZIKV VLPs have been reported featuring the co-expression of the prM-E, prM-E-NS1, C-prM-E, and NS2B/NS3 viral genes in human cells. To minimize the effect of the cross-reactive ADE-facilitating antibodies between ZIKV and DENV, several novel mutations have been reported either in or near the FL of DII or DIII to dampen the production of cross-reactive antibodies. Future ZIKV vaccine design efforts should be focused on eliciting improved neutralizing antibodies with a reduced level of cross-reactivity to confer sterilizing immunity.
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Vacinas Virais , Infecção por Zika virus , Zika virus , Anticorpos Antivirais/imunologia , Humanos , Modelos Moleculares , Vacinas de DNA , Proteínas Virais/genética , Proteínas Virais/imunologia , Zika virus/química , Zika virus/imunologia , Zika virus/ultraestrutura , Infecção por Zika virus/prevenção & controle , Infecção por Zika virus/virologiaRESUMO
BACKGROUND: Asians have higher frequency of intracranial arterial stenosis. The present study aimed to compare the clinical features and outcomes of ischemic stroke patients with and without middle cerebral artery (MCA) stenosis, assessed by transcranial sonography (TCS), based on the Taiwan Stroke Registry (TSR). METHODS: Patients with acute ischemic stroke or transient ischemic attack registered in the TSR, and received both carotid duplex and TCS assessment were categorized into those with stenosis (≥50%) and without (<50%) in the extracranial internal carotid artery (ICA) and MCA, respectively. Logistic regression analysis, Kaplan-Meier method and Cox proportional hazard model were applied to assess relevant variables between groups. RESULTS: Of 6003 patients, 23.3% had MCA stenosis, 10.1% ICA stenosis, and 3.9% both MCA and ICA stenosis. Patients with MCA stenosis had greater initial NIHSS, higher likelihood of stroke-in-evolution, and more severe disability than those without (all p<0.001). Patients with MCA stenosis had higher prevalence of hypertension, diabetes and hypercholesterolemia. Patients with combined MCA and extracranial ICA stenosis had even higher NIHSS, worse functional outcome, higher risk of stroke recurrence or death (hazard ratio, 2.204; 95% confidence intervals, 1.440-3.374; p<0.001) at 3 months after stroke than those without MCA stenosis. CONCLUSIONS: In conclusion, MCA stenosis was more prevalent than extracranial ICA stenosis in ischemic stroke patients in Taiwan. Patients with MCA stenosis, especially combined extracranial ICA stenosis, had more severe neurological deficit and worse outcome.
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Constrição Patológica/patologia , Artéria Cerebral Média/patologia , Acidente Vascular Cerebral/fisiopatologia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/patologiaRESUMO
Lipopolysaccharide (LPS, endotoxin) is the major component of Gram-negative bacterial outer surface membrane. LPS released from bacteria into bloodstream during infection may cause serious unwanted stimulation of host's immune system and lead to septic shock of the patient. Recently, we have developed a strategy to increase salt resistance and LPS neutralization of short antimicrobial peptides by adding ß-naphthylalanine end-tags to their termini. Herein, correlations between membrane immersion depth, orientation, and antiendotoxin activities of the antimicrobial peptides S1 and S1-Nal-Nal have been investigated via solution structure, paramagnetic resonance enhancement, and saturation transfer difference NMR studies. Unlike the parent peptide S1, S1-Nal-Nal rotated its two terminal ß-naphthylalanine residues into the hydrophobic lipid A motif of LPS micelles. The LPS-induced inflammation may then be prohibited by the blocked lipid A motif.
Assuntos
Anti-Inflamatórios não Esteroides/síntese química , Antídotos/síntese química , Peptídeos Catiônicos Antimicrobianos/síntese química , Lipopolissacarídeos/antagonistas & inibidores , Macrófagos/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Antídotos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Linhagem Celular , Relação Dose-Resposta a Droga , Desenho de Fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Lipopolissacarídeos/farmacologia , Macrófagos/citologia , Macrófagos/imunologia , Camundongos , Modelos Moleculares , Relação Estrutura-Atividade , Termodinâmica , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/biossínteseRESUMO
BACKGROUND: Many studies have investigated the association between markers for peripheral inflammation and risk of dementia, but the results have been conflicting. We aimed to evaluate the association between a specific inflammation marker, C-reactive protein (CRP), and dementia in an elderly Asian community cohort. METHODS: The cohort included 1436 individuals (ages 65 and older) from a national representative sample in Taiwan. Dementia incidence was identified using International Classification of Diseases, Ninth Revision codes for vascular dementia, Alzheimer disease, and nonvascular dementia. Baseline characteristics and CRP levels were determined. A Cox proportional hazard model and Fine and Grays model were adjusted for stroke and competing risk of death to estimate the association between inflammation and development of dementia. RESULTS: During 11.04 years (median) of follow-up, 607 individuals (50.77%) died and 260 individuals (18.11%) were diagnosed with dementia. Those with high CRP had a 55% higher risk of dementia (hazard ratio 1.55; 95% confidence interval 1.21-2.00) compared with those with normal CRP. After adjusting for possible confounding cardiovascular risk factors, high CRP was independently associated with vascular dementia but not Alzheimer disease. CONCLUSIONS: In this prospective study of an elderly Asian community cohort with more than 10 years of follow-up, the baseline serum CRP level was associated with future development of vascular dementia, but not Alzheimer disease after adjusting for common cardiovascular risk factors, stroke, and competing risk of death.
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Povo Asiático , Proteína C-Reativa/análise , Demência/epidemiologia , Valor Preditivo dos Testes , Idoso , Feminino , Humanos , Incidência , Masculino , Estudos Prospectivos , Taiwan/epidemiologiaRESUMO
PURPOSE: Among the medications approved for Alzheimer's disease (AD), rivastigmine is the only one available as transdermal patch. The aim of this study was to evaluate compliance and caregivers' preference with oral and transdermal (rivastigmine) monotherapy in patients with mild-to-moderate AD from Taiwan. METHODS: Real-world Evaluation of Compliance And Preference in Alzheimer's disease treatment (RECAP) in Taiwan was a prospective, noninterventional, observational study with a 24-week (±8 weeks) observational period for each participant. Eligible patients were grouped into one of the two treatment cohorts based on the baseline AD therapy: oral (donepezil, galantamine, rivastigmine, or memantine) or transdermal (rivastigmine patch). The primary end points were caregiver preference and caregiver assessment of patients' compliance to the current medication (oral or transdermal medication) at Week 24 (end of the study). Safety was assessed by recording any adverse events. RESULTS: A total of 301 patients (age: 77.6±7.19 years) were enrolled from nine centers in Taiwan, of whom 138 (45.8%) patients were in the transdermal monotherapy cohort. Caregivers of patients who were exposed to both forms of therapies demonstrated a higher preference for transdermal rivastigmine monotherapy than the oral monotherapy (82.4% [n=61] versus 17.6% [n=13], P<0.0001); for patients treated with only one therapy, the caregivers' preference was significantly in favor of the treatment to which the patient was exposed (both P<0.0001). In both cohorts, patients showed good compliance, with an overall score of 8.65±1.38 on an 11-point scale. Of 301 enrolled patients, 102 (33.9%) reported at least one adverse event during the study (51 patients each in the two cohorts). CONCLUSION: With the higher caregiver preference and a good patient compliance, the trans-dermal rivastigmine patch is a suitable treatment choice for patients with mild-to-moderate AD, especially for patients intolerant to oral therapies.
RESUMO
Release of lipopolysaccharide (LPS) (endotoxin) from bacteria into the bloodstream may cause serious unwanted stimulation of the host immune system. Some but not all antimicrobial peptides can neutralize LPS-stimulated proinflammatory responses. Salt resistance and serum stability of short antimicrobial peptides can be boosted by adding ß-naphthylalanine to their termini. Herein, significant antiendotoxin effects were observed in vitro and in vivo with the ß-naphthylalanine end-tagged variants of the short antimicrobial peptides S1 and KWWK.
Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Lipopolissacarídeos/antagonistas & inibidores , Peptídeos Catiônicos Antimicrobianos/química , Interações Hidrofóbicas e Hidrofílicas , Testes de Sensibilidade Microbiana , beta-Alanina/análogos & derivados , beta-Alanina/químicaRESUMO
We describe a strategy to boost anticancer activity and reduce normal cell toxicity of short antimicrobial peptides by adding positive charge amino acids and non-nature bulky amino acid ß-naphthylalanine residues to their termini. Among the designed peptides, K4R2-Nal2-S1 displayed better salt resistance and less toxicity to hRBCs and human fibroblast than Nal2-S1 and K6-Nal2-S1. Fluorescence microscopic studies indicated that the FITC-labeled K4R2-Nal2-S1 preferentially binds cancer cells and causes apoptotic cell death. Moreover, a significant inhibition in human lung tumor growth was observed in the xenograft mice treated with K4R2-Nal2-S1. Our strategy provides new opportunities in the development of highly effective and selective antimicrobial and anticancer peptide-based therapeutics.
Assuntos
Antibacterianos/farmacologia , Antibióticos Antineoplásicos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Animais , Apoptose , Linhagem Celular Tumoral , Escherichia coli/efeitos dos fármacos , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
We report on the preparation of a new type of immunotoxin by conjugation of an epidermal growth factor receptor (EGFR)-binding peptide and an R46E mutation of thermostable direct hemolysin from Grimontia hollisae, (Gh-TDH(R) (46E) /EB). The hybrid immunotoxin was purified to homogeneity and showed a single band with slight slower mobility than that of Gh-TDH(R) (46E) . Cytotoxicity assay of Gh-TDH(R) (46E) /EB on EGFR highly, moderately, low, and non-expressed cells, A431, MDA-MB-231, HeLa, and HEK293 cells, respectively, showed apparent cytotoxicity on A431 and MDA-MB-231 cells but not on HeLa or HEK293 cells. In contrast, no cytotoxicity was observed for these cells treated with either Gh-TDH(R) (46E) or EB alone, indicating enhanced cytotoxic efficacy of Gh-TDH(R) (46E) by the EGFR binding moiety. Further antitumor activity assay of Gh-TDH(R) (46E) /EB in a xenograft model of athymic nude mice showed obvious shrinkage of tumor size and degeneration, necrosis, and lesions of tumor tissues compared to the normal tissues. Therefore, the combination of Gh-TDH(R) (46E) with target affinity agents opens new possibilities for pharmacological treatment of cancers and potentiates the anticancer drug's effect.
Assuntos
Antineoplásicos/farmacologia , Proteínas de Bactérias/farmacologia , Receptores ErbB/genética , Proteínas Hemolisinas/farmacologia , Imunotoxinas/farmacologia , Proteínas Recombinantes/farmacologia , Animais , Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Toxinas Bacterianas/farmacologia , Linhagem Celular Tumoral , Receptores ErbB/metabolismo , Feminino , Células HEK293 , Células HeLa , Proteínas Hemolisinas/genética , Humanos , Camundongos , Camundongos Nus , Proteínas Recombinantes/genética , Vibrionaceae/genéticaRESUMO
We enrolled 221 patients with elective carotid artery stenting (CAS). Patients with contralateral carotid stenosis exceeding 50%, insufficient vertebral artery (VA) flows, or angioplasty at subclavian artery were excluded. All patients underwent serial cerebral ultrasound studies. Of the 116 included patients, the direction of ophthalmic artery (OA) flow was forward in 74 patients while reversed in 42. The reversed flow group had worse ipsilateral stenosis, higher hemoglobin, and cardiac output. After CAS, the reversed flow group had an immediate recovery of ipsilateral internal carotid artery flow volume (FV; P < .0001), time average velocity (TAV) of middle cerebral artery (P = .02), and normalization of OA flow. The forward flow group had gradual decrement in TAV of contralateral anterior cerebral artery (P = .01) and total FV of VA (P = .001). Our results suggest CAS improves cerebral hemodynamics through different ways regardless of the direction of OA flow.
Assuntos
Angioplastia/instrumentação , Estenose das Carótidas/terapia , Circulação Cerebrovascular , Hemodinâmica , Artéria Cerebral Média/fisiopatologia , Artéria Oftálmica/fisiopatologia , Stents , Idoso , Estenose das Carótidas/diagnóstico , Estenose das Carótidas/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/diagnóstico por imagem , Artéria Oftálmica/diagnóstico por imagem , Valor Preditivo dos Testes , Recuperação de Função Fisiológica , Fluxo Sanguíneo Regional , Índice de Gravidade de Doença , Resultado do Tratamento , Ultrassonografia Doppler em Cores , Ultrassonografia Doppler TranscranianaRESUMO
BACKGROUND: Coronary artery disease (CAD) may coexist with extracranial carotid artery stenosis (ECAS), but the influence of CAD on procedure-related complications after carotid artery stenting (CAS) has not been well investigated. The study aimed to determine the impact of CAD on the occurrence of peri-CAS cerebral ischemic lesions on diffusion-weighted imaging (DWI) scanning. METHODS: Coronary angiography was performed within six months before CAS. DWI scanning was repetitively done within 1 week before and after CAS. Clinical outcome measures were stroke, angina, myocardial infarction and death within 30 days. RESULTS: Among 126 patients (69.5±9.0 years) recruited for unilateral protected CAS, 33 (26%) patients had peri-CAS DWI-positive lesions. CAD was noted in 79% (26 in 33) and 48% (45 in 93) of patients with and without peri-CAS DWI-positive lesions (OR, 4.0; 95% CI, 1.6-10.0; Pâ=â.0018), and the number of concomitant CAD on coronary angiography was positively correlated with the risk for peri-CAS DWI-positive lesions (Pâ=â.0032). In patients with no CAD (nâ=â55), asymptomatic CAD (nâ=â41) and symptomatic CAD (nâ=â30), the occurrence rates of peri-CAS DWI-positive lesions were 13%, 41% and 30% (Pâ=â.0048), and the peri-CAS stroke rates were 2%, 7% and 0% (Pâ=â.2120). CONCLUSIONS: The severity of morphological CAD and the presence of either symptomatic or asymptomatic CAD are associated with the occurrence of peri-CAS cerebral ischemic lesions.
Assuntos
Isquemia Encefálica/etiologia , Artérias Carótidas/patologia , Doença da Artéria Coronariana/complicações , Stents/efeitos adversos , Idoso , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , MasculinoRESUMO
BACKGROUND AND PURPOSE: Patients with low estimated glomerular filtration rate (eGFR) and proteinuria may be at increased risk for stroke. This study investigated whether low eGFR and proteinuria are outcome predictors in stroke patients treated with intravenous thrombolysis. METHODS: We studied 432 consecutive stroke patients who received thrombolysis from January 2006 to December 2012, in Taiwan. Unfavorable outcome was defined as modified Rankin scale ≥2 at 3 months after stroke. Proteinuria was classified as negative or trace, mild, and moderate to severe. Using logistic regression analysis, we identified independent factors for unfavorable outcome after thrombolysis. RESULTS: Of all patients, 32.7% had proteinuria. Patients with proteinuria were older, had higher frequencies of diabetes mellitus, hyperlipidemia, atrial fibrillation, lower eGFR, and greater severity of stroke upon admission than those without proteinuria. Proteinuria, not low eGFR, was an independent predictor for unfavorable outcome for stroke (ORâ=â2.00 for mild proteinuria, pâ=â0.035; ORâ=â2.54 for moderate to severe proteinuria, pâ=â0.035). However, no clear relationship was found between proteinuria and symptomatic hemorrhage after thrombolysis. CONCLUSIONS: Proteinuria is an independent predictor of unfavorable outcome for acute ischemic stroke in patients treated with intravenous thrombolysis, indicating the crucial role of chronic kidney disease on the effectiveness of thrombolysis.