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1.
Artículo en Inglés | MEDLINE | ID: mdl-37604195

RESUMEN

BACKGROUND: Chronic hydrocephalus is a common complication of aneurysmal subarachnoid hemorrhage (aSAH); however, the risk factors and the mechanisms underlying its occurrence have yet to be fully elucidated. The purpose of this study was to identify biomarkers that could be used to predict chronic hydrocephalus after aSAH and to investigate the relationships. METHODS: We analyzed cerebrospinal fluid (CSF) samples from 19 patients with chronic hydrocephalus after aSAH and 44 controls without hydrocephalus after aSAH. Enzyme-linked immunosorbent assay was used to determine the levels of leucine-rich alpha-2-glycoprotein (LRG), transforming growth factor-ß (TGF-ß), Smad1, Smad4, Smad5, Smad8, activin receptor-like kinase 1 (Alk-1), activin receptor-like kinase 5 (Alk-5), P38, and TGF-ß type II receptor (TGFßRII) in CSF samples. RESULTS: In the CSF of patients with chronic hydrocephalus after aSAH, the levels of LRG, TGF-ß, Alk-1, Smad5, and TGFßRII were significantly increased (p < 0.05) and the levels of Smad1, Smad4, and Smad8 were significantly decreased (p < 0.05). There were no significant differences between the two groups concerning the levels of P38 and Alk-5 (p > 0.05). The analysis also identified significant correlations between specific biomarkers: LRG and Smad1, LRG and Smad5, TGF-ß and Alk-1, and Alk-1 and Smad4 (p < 0.05); the Pearson's correlation coefficients for these relationships were -0.341, 0.257, 0.256, and -0.424, respectively. CONCLUSION: The levels of LRG, TGF-ß, Alk-1, TGFßRII, Smad1/5/8, and Smad4 in the CSF are potentially helpful as predictive biomarkers of chronic hydrocephalus after aSAH. Moreover, the LRG-TGF-ß-Alk-1/TGFßRII-Smad1/5/8-Smad4 signaling pathway is highly likely to be involved in the pathogenic process of chronic hydrocephalus after aSAH.

2.
Front Immunol ; 13: 1000681, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36248865

RESUMEN

Background: The safety and immunogenicity of a personalized neoantigen-based peptide vaccine, iNeo-Vac-P01, was reported previously in patients with a variety of cancer types. The current study investigated the synergistic effects of radiofrequency ablation (RFA) and neoantigen vaccination in cancer patients and tumor-bearing mice. Methods: Twenty-eight cancer patients were enrolled in this study, including 10 patients who had received RFA treatment within 6 months before vaccination (Cohort 1), and 18 patients who had not (Cohort 2). Individualized neoantigen peptide vaccines were designed, manufactured, and subcutaneously administrated with GM-CSF as an adjuvant for all patients. Mouse models were employed to validate the synergistic efficacy of combination treatment of RFA and neoantigen vaccination. Results: Longer median progression free survival (mPFS) and median overall survival (mOS) were observed in patients in Cohort 1 compared to patients in Cohort 2 (4.42 and 20.18 months vs. 2.82 and 10.94 months). The results of ex vivo IFN-γ ELISpot assay showed that patients in Cohort 1 had stronger neoantigen-specific immune responses at baseline and post vaccination. Mice receiving combination treatment of RFA and neoantigen vaccines displayed higher antitumor immune responses than mice receiving single modality. The combination of PD-1 blockage with RFA and neoantigen vaccines further enhanced the antitumor response in mice. Conclusion: Neoantigen vaccination after local RFA treatment could improve the clinical and immune response among patients of different cancer types. The synergistic antitumor potentials of these two modalities were also validated in mice, and might be further enhanced by immune checkpoint inhibition. The mechanisms of their synergies require further investigation. Clinical trial registration: https://clinicaltrials.gov/, identifier NCT03662815.


Asunto(s)
Vacunas contra el Cáncer , Neoplasias , Ablación por Radiofrecuencia , Animales , Ratones , Factor Estimulante de Colonias de Granulocitos y Macrófagos , Inhibidores de Puntos de Control Inmunológico , Inmunoterapia/métodos , Neoplasias/terapia , Receptor de Muerte Celular Programada 1 , Vacunación , Vacunas de Subunidad
3.
J Ethnopharmacol ; 291: 115176, 2022 06 12.
Artículo en Inglés | MEDLINE | ID: mdl-35293313

RESUMEN

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. The authors have plagiarized/duplicated part of a paper that appeared in Neurosci Lett, 549 (2013) 63-68, (https://doi.org/10.1016/j.neulet.2013.06.002). Several images in the Journal of Ethnopharmacology paper; 3A, 3B, 4A, 4B correspond to figures; 2A, 2B, 3A and 3B respectively as published in Neuroscience Letters. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

4.
J Org Chem ; 87(2): 1470-1476, 2022 01 21.
Artículo en Inglés | MEDLINE | ID: mdl-34985274

RESUMEN

In this study, we developed an efficient approach for disulfide bond formation in peptides utilizing the Pt(IV) complex trans-[PtBr2(CN)4]2- to mediate Acm and Thz deprotections. [PtBr2(CN)4]2- can oxidatively deprotect two Acm groups or deprotect one Thz group and one Acm group to directly form an intramolecular disulfide bond in peptides. Several disulfide-containing peptides with excellent yields were achieved via the deprotection method in an aqueous medium under aerobic conditions. Kinetic studies indicated that the dominant path of the reaction is of first-order in both [Pt(IV)] and [peptide]; moreover, the deprotection rate increased dramatically with the addition of NaBr. A mechanism including a bromide-bridge-mediated electron transfer process was proposed. Apamin, α-conotoxin SI, and the parallel homodimer of oxytocin, all containing two disulfide bonds, were synthesized regioselectively through a one-pot method by the combined use of the above deprotection approach with oxidants l-methionine selenoxide and [PtBr2(CN)4]2-. All of the reactions were completed within 30 min to afford good yields for these peptides.


Asunto(s)
Cisteína , Péptidos , Disulfuros , Cinética , Tiazolidinas
5.
Front Immunol ; 12: 691605, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34484187

RESUMEN

Background: Neoantigens are critical targets to elicit robust antitumor T-cell responses. Personalized cancer vaccines developed based on neoantigens have shown promising results by prolonging cancer patients' overall survival (OS) for several cancer types. However, the safety and efficacy of these vaccine modalities remains unclear in pancreatic cancer patients. Methods: This retrospective study enrolled 7 advanced pancreatic cancer patients. Up to 20 neoantigen peptides per patient identified by our in-house pipeline iNeo-Suite were selected, manufactured and administered to these patients with low tumor mutation burden (TMB) (less than 10 mutations/Mb). Each patient received multiple doses of vaccine depending on the progression of the disease. Peripheral blood samples of each patient were collected pre- and post-vaccination for the analysis of the immunogenicity of iNeo-Vac-P01 through ELISpot assay and flow cytometry. Results: No severe vaccine-related adverse effects were witnessed in patients enrolled in this study. The mean OS, OS associated with vaccine treatment and progression free survival (PFS) were reported to be 24.1, 8.3 and 3.1 months, respectively. Higher peripheral IFN-γ titer and CD4+ or CD8+ effector memory T cells count post vaccination were found in patients with relatively long overall survival. Remarkably, for patient P01 who had a 21-month OS associated with vaccine treatment, the abundance of antigen-specific TCR clone drastically increased from 0% to nearly 100%, indicating the potential of iNeo-Vac-P01 in inducing the activation of a specific subset of T cells to kill cancer cells. Conclusions: Neoantigen identification and selection were successfully applied to advanced pancreatic cancer patients with low TMB. As one of the earliest studies that addressed an issue in treating pancreatic cancer with personalized vaccines, it has been demonstrated that iNeo-Vac-P01, a personalized neoantigen-based peptide vaccine, could improve the currently limited clinical efficacy of pancreatic cancer. Clinical Trial Registration: ClinicalTrials.gov, identifier (NCT03645148).Registered August 24, 2018 - Retrospectively registered.


Asunto(s)
Antígenos de Neoplasias/inmunología , Vacunas contra el Cáncer/uso terapéutico , Neoplasias Pancreáticas/terapia , Vacunas de Subunidad/uso terapéutico , Vacunas contra el Cáncer/efectos adversos , Femenino , Humanos , Inmunoterapia/efectos adversos , Masculino , Persona de Mediana Edad , Neoplasias Pancreáticas/inmunología , Neoplasias Pancreáticas/mortalidad , Neoplasias Pancreáticas/patología , Medicina de Precisión , Estudios Retrospectivos , Análisis de Supervivencia , Linfocitos T/inmunología , Vacunas de Subunidad/efectos adversos
6.
J Org Chem ; 86(5): 4035-4044, 2021 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-33620221

RESUMEN

In this study, l-methionine selenoxide (MetSeO) was used as an oxidant for the construction of peptide disulfide bonds. Excellent yields for various disulfide-containing peptides were achieved via the MetSeO oxidation method in different solvents and on a resin. Most importantly, the construction of disulfide bonds can be performed in the trifluoroacetic acid cocktail used for the cleavage of peptides from the resin, which obviates the steps of peptide purification and lyophilization. This facilitates and simplifies the synthesis of disulfide-containing peptides. Kinetic and mechanistic studies of the reaction between MetSeO and dithiothreitol (DTT, a model compound of dicysteine-containing peptide) show that the reaction is first order in both [MetSeO] and [DTT], and a reaction mechanism is proposed that can help us gain insights into the reaction of the oxidative synthesis of disulfide bonds via MetSeO oxidation.


Asunto(s)
Disulfuros , Metionina , Metionina/análogos & derivados , Metionina/metabolismo , Compuestos de Organoselenio , Oxidación-Reducción , Péptidos , Óxidos de Selenio
7.
Front Psychiatry ; 11: 570574, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33101085

RESUMEN

BACKGROUND: Bipolar disorder (BD) and alcohol use disorder (AUD) are two major independent causes of psychopathology in the general population. The prevalence of AUD in BD is high. Identifying the clinical and demographic features of patients with BD who may develop AUD could help with early identification and intervention. METHODS: Data from 238 patients diagnosed with BD were gathered on alcohol use, social demographics, longitudinal course of BD, clinical features of the most severe lifetime manic and depressive episodes, comorbid physical diseases, anxiety disorders, and other substance use disorders. RESULTS: We found that 74 of 238 BD patients had AUD (67 with alcohol dependence and 7 with alcohol abuse). Bivariate logistic regression analysis and multivariate logistic regression analysis found that the best predictors of AUD in patients with BD were being male (OR = 2.086, 95% CI = 1.094-3.979, p = 0.001), younger (OR = 0.965, 95% CI = 0.935-0.996, p = 0.026), and comorbidity with other unclassified substance dependence (OR = 10.817, 95% CI = 1.238-94.550, p = 0.031). CONCLUSIONS: Male, younger current age, and having other substance use disorders were independently associated with AUD.

8.
Adv Clin Exp Med ; 29(6): 661-668, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32614526

RESUMEN

BACKGROUND: New glucagon-like peptide-1 (GLP-1) analogues developed in recent years have a long half-life and offer further prospects for clinical application. At present, the neuroprotection of GLP-1 analogues in Alzheimer's disease (AD) has just begun to be explored. OBJECTIVES: To investigate how glucagon-like peptide-1 (liraglutide) plays a protective role in AD by regulating tau activation and BACE1 expression. MATERIAL AND METHODS: Human neuroblastoma cell line SH-SY5Y cells were cultured in vitro and pretreated with different concentrations of liraglutide, and then treated with different concentrations of okadaic acid (OA) in order to observe the apoptosis of the SH-SY5Y cells. After liraglutide treatment, the apoptosis of neurons in AD rats was detected using flow cytometry, and tau activation and ß-site APP cleaving enzyme 1 (BACE1) expression were detected using western blot. RESULTS: Different concentrations of OA were able to induce apoptosis of SH-SY5Y cells in a dose-dependent manner. Different concentrations of liraglutide were used to pretreat SH-SY5Y cells, which were able to protect the SH-SY5Y cells from apoptosis induced by OA. Okadaic acid significantly increased tau activation and BACE1 expression in the SH-SY5Y cells, which was blocked with liraglutide pretreatment. The results of a water maze experiment showed that liraglutide had significant protective effects on memory and cognitive ability in AD rats induced with OA, inhibited apoptosis of neural cells in AD rats, and inhibited tau activation and BACE1 expression of neural cells in AD rats induced with OA. CONCLUSIONS: Liraglutide has a protective effect on AD in vivo and in vitro, which may be mediated by preventing neuronal apoptosis and inhibiting the activation of tau and the expression of BACE1.


Asunto(s)
Enfermedad de Alzheimer , Liraglutida , Fármacos Neuroprotectores , Receptores de la Hormona Gastrointestinal , Enfermedad de Alzheimer/tratamiento farmacológico , Secretasas de la Proteína Precursora del Amiloide/efectos de los fármacos , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Secretasas de la Proteína Precursora del Amiloide/uso terapéutico , Animales , Ácido Aspártico Endopeptidasas/efectos de los fármacos , Ácido Aspártico Endopeptidasas/metabolismo , Ácido Aspártico Endopeptidasas/uso terapéutico , Línea Celular Tumoral , Péptido 1 Similar al Glucagón/uso terapéutico , Humanos , Liraglutida/farmacología , Fármacos Neuroprotectores/farmacología , Ratas , Receptores de la Hormona Gastrointestinal/agonistas , Receptores de la Hormona Gastrointestinal/antagonistas & inhibidores
9.
Mol Med Rep ; 19(1): 327-337, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30431087

RESUMEN

Early brain injury (EBI)­induced neuronal apoptosis is primarily responsible for the subsequent complications of aneurysmal subarachnoid hemorrhage (aSAH), which may increase the risk of mortality in patients with aSAH. c­Jun N­terminal kinase (JNK) has been demonstrated to be a promoter of EBI­induced cell apoptosis, although the mechanism has yet to be fully elucidated. The present study aimed to explore whether the role of JNK1 is associated with tumor protein p53 (p53), which is one of the most important factor that triggers cell apoptosis. JNK1 expression was downregulated via in vivo small interfering RNA transfection in an aSAH rat model in order to assess differences in the behavior, survival times, morphology and genetics of the experimental animals. The results revealed that JNK1 inhibition improved the neurological scores and survival times of SAH rats by interrupting cascaded neuronal apoptosis. The interruption of EBI­induced neuronal apoptosis may originate from a decrease in the level of p53 phosphorylation and deactivation of the downstream mitochondrial apoptotic pathway. Taken together, these results suggest that JNK1 may be a promising target for improving the prognosis of patients with aSAH.


Asunto(s)
Apoptosis , Lesiones Encefálicas/patología , Mitocondrias/patología , Proteína Quinasa 8 Activada por Mitógenos/metabolismo , Neuronas/patología , Hemorragia Subaracnoidea/patología , Proteína p53 Supresora de Tumor/metabolismo , Animales , Proteínas Reguladoras de la Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/metabolismo , Lesiones Encefálicas/metabolismo , Células Cultivadas , Masculino , Mitocondrias/metabolismo , Proteína Quinasa 8 Activada por Mitógenos/antagonistas & inhibidores , Proteína Quinasa 8 Activada por Mitógenos/genética , Neuronas/metabolismo , Fosforilación , ARN Interferente Pequeño , Ratas , Ratas Sprague-Dawley , Hemorragia Subaracnoidea/metabolismo , Proteína p53 Supresora de Tumor/genética
10.
Sci Rep ; 8(1): 4806, 2018 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-29555911

RESUMEN

Tick saliva is a rich source of modulators of vascular biology. We have characterized Ixonnexin, a member of the "Basic-tail" family of salivary proteins from the tick Ixodes scapularis. Ixonnexin is a 104 residues (11.8 KDa), non-enzymatic basic protein which contains 3 disulfide bonds and a C-terminal rich in lysine. It is homologous to SALP14, a tick salivary FXa anticoagulant. Ixonnexin was produced by ligation of synthesized fragments (51-104) and (1-50) followed by folding. Ixonnexin, like SALP14, interacts with FXa. Notably, Ixonnexin also modulates fibrinolysis in vitro by a unique salivary mechanism. Accordingly, it accelerates plasminogen activation by tissue-type plasminogen activator (t-PA) with Km 100 nM; however, it does not affect urokinase-mediated fibrinolysis. Additionally, lysine analogue ε-aminocaproic acid inhibits Ixonnexin-mediated plasmin generation implying that lysine-binding sites of Kringle domain(s) of plasminogen or t-PA are involved in this process. Moreover, surface plasmon resonance experiments shows that Ixonnexin binds t-PA, and plasminogen (KD 10 nM), but not urokinase. These results imply that Ixonnexin promotes fibrinolysis by supporting the interaction of plasminogen with t-PA through formation of an enzymatically productive ternary complex. Finally, in vivo experiments demonstrates that Ixonnexin inhibits FeCl3-induced thrombosis in mice. Ixonnexin emerges as novel modulator of fibrinolysis which may also affect parasite-vector-host interactions.


Asunto(s)
Arteriopatías Oclusivas/prevención & control , Fibrinólisis/efectos de los fármacos , Plasminógeno/metabolismo , Saliva/metabolismo , Proteínas y Péptidos Salivales/farmacología , Trombosis/prevención & control , Garrapatas/metabolismo , Activador de Tejido Plasminógeno/metabolismo , Animales , Arteriopatías Oclusivas/inducido químicamente , Arteriopatías Oclusivas/patología , Cloruros/toxicidad , Compuestos Férricos/toxicidad , Ratones , Noxas/toxicidad , Trombosis/inducido químicamente , Trombosis/patología
11.
Sci Transl Med ; 9(405)2017 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-28855397

RESUMEN

In HIV infection, persistent inflammation despite effective antiretroviral therapy is linked to increased risk of noninfectious chronic complications such as cardiovascular and thromboembolic disease. A better understanding of inflammatory and coagulation pathways in HIV infection is needed to optimize clinical care. Markers of monocyte activation and coagulation independently predict morbidity and mortality associated with non-AIDS events. We identified a specific subset of monocytes that express tissue factor (TF), persist after virological suppression, and trigger the coagulation cascade by activating factor X. This subset of monocytes expressing TF had a distinct gene signature with up-regulated innate immune markers and evidence of robust production of multiple proinflammatory cytokines, including interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), and IL-6, ex vivo and in vitro upon lipopolysaccharide stimulation. We validated our findings in a nonhuman primate model, showing that TF-expressing inflammatory monocytes were associated with simian immunodeficiency virus (SIV)-related coagulopathy in the progressive [pigtail macaques (PTMs)] but not in the nonpathogenic (African green monkeys) SIV infection model. Last, Ixolaris, an anticoagulant that inhibits the TF pathway, was tested and potently blocked functional TF activity in vitro in HIV and SIV infection without affecting monocyte responses to Toll-like receptor stimulation. Strikingly, in vivo treatment of SIV-infected PTMs with Ixolaris was associated with significant decreases in D-dimer and immune activation. These data suggest that TF-expressing monocytes are at the epicenter of inflammation and coagulation in chronic HIV and SIV infection and may represent a potential therapeutic target.


Asunto(s)
Trastornos de la Coagulación Sanguínea/patología , Infecciones por VIH/sangre , Infecciones por VIH/patología , Inflamación/patología , Monocitos/metabolismo , Síndrome de Inmunodeficiencia Adquirida del Simio/sangre , Virus de la Inmunodeficiencia de los Simios/fisiología , Tromboplastina/metabolismo , Animales , Antirretrovirales/farmacología , Antirretrovirales/uso terapéutico , Anticuerpos Antivirales/inmunología , Coagulación Sanguínea/efectos de los fármacos , Trastornos de la Coagulación Sanguínea/sangre , Trastornos de la Coagulación Sanguínea/tratamiento farmacológico , Trastornos de la Coagulación Sanguínea/inmunología , Chlorocebus aethiops , Enfermedad Crónica , Citocinas/metabolismo , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/inmunología , Humanos , Mediadores de Inflamación/metabolismo , Receptores de Lipopolisacáridos/metabolismo , Lipopolisacáridos/farmacología , Receptor PAR-1/metabolismo , Transducción de Señal , Síndrome de Inmunodeficiencia Adquirida del Simio/tratamiento farmacológico , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/patología
12.
Int J Oncol ; 49(6): 2387-2398, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27748800

RESUMEN

TGF-ß-induced epithelial-mesenchymal transition (EMT) plays an important role in tumor progression. We assessed whether the TGF-ß-induced EMT contributed to vasculogenic mimicry (VM) formation in glioma, we established an SHG44 cell line stably transfected with TGF-ß cDNA loaded lentivirus. SB203580 was employed to inhibit the TGF-ß-induced EMT. The results showed that the VM forming ability of cells could be improved by TGF-ß over-expression. The migration and invasion capabilities of cells were also enhanced due to EMT. SB203580 was able to weaken cell migration, invasion and VM forming abilities via blocking p38/MAPK signaling pathways, but it had tiny influence on MMP/LAMC2 chain. Consequently, we concluded that EMT inhibition via p38/MAPK signaling pathways would partly impair TGF-ß-induced VM formation in glioma.


Asunto(s)
Transición Epitelial-Mesenquimal/efectos de los fármacos , Glioma/patología , Sistema de Señalización de MAP Quinasas/genética , Factor de Crecimiento Transformador beta/antagonistas & inhibidores , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidores , Inhibidores de la Angiogénesis/farmacología , Animales , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Plasticidad de la Célula/fisiología , Proliferación Celular/efectos de los fármacos , Glioma/genética , Humanos , Imidazoles/farmacología , Lentivirus/genética , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Invasividad Neoplásica/patología , Trasplante de Neoplasias , Piridinas/farmacología , Transfección , Factor de Crecimiento Transformador beta/genética , Trasplante Heterólogo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
13.
PLoS Negl Trop Dis ; 10(1): e0004298, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26745503

RESUMEN

BACKGROUND: Hematophagous mosquitos and ticks avoid host hemostatic system through expression of enzyme inhibitors targeting proteolytic reactions of the coagulation and complement cascades. While most inhibitors characterized to date were found in the salivary glands, relatively few others have been identified in the midgut. Among those, Boophilin is a 2-Kunitz multifunctional inhibitor targeting thrombin, elastase, and kallikrein. However, the kinetics of Boophilin interaction with these enzymes, how it modulates platelet function, and whether it inhibits thrombosis in vivo have not been determined. METHODOLOGY/PRINCIPAL FINDINGS: Boophilin was expressed in HEK293 cells and purified to homogeneity. Using amidolytic assays and surface plasmon resonance experiments, we have demonstrated that Boophilin behaves as a classical, non-competitive inhibitor of thrombin with respect to small chromogenic substrates by a mechanism dependent on both exosite-1 and catalytic site. Inhibition is accompanied by blockade of platelet aggregation, fibrin formation, and clot-bound thrombin in vitro. Notably, we also identified Boophilin as a non-competitive inhibitor of FXIa, preventing FIX activation. In addition, Boophilin inhibits kallikrein activity and the reciprocal activation, indicating that it targets the contact pathway. Furthermore, Boophilin abrogates cathepsin G- and plasmin-induced platelet aggregation and partially affects elastase-mediated cleavage of Tissue Factor Pathway Inhibitor (TFPI). Finally, Boophilin inhibits carotid artery occlusion in vivo triggered by FeCl3, and promotes bleeding according to the mice tail transection method. CONCLUSION/SIGNIFICANCE: Through inhibition of several enzymes involved in proteolytic cascades and cell activation, Boophilin plays a major role in keeping the midgut microenvironment at low hemostatic and inflammatory tonus. This response allows ticks to successfully digest a blood meal which is critical for metabolism and egg development. Boophilin is the first tick midgut FXIa anticoagulant also found to inhibit thrombosis.


Asunto(s)
Fibrinolíticos/aislamiento & purificación , Fibrinolíticos/metabolismo , Inhibidores de Proteasas/aislamiento & purificación , Inhibidores de Proteasas/metabolismo , Rhipicephalus/química , Animales , Línea Celular , Factor XIa/antagonistas & inhibidores , Tracto Gastrointestinal/química , Expresión Génica , Humanos , Calicreínas/antagonistas & inhibidores , Ratones , Agregación Plaquetaria/efectos de los fármacos , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Trombina/antagonistas & inhibidores , Trombosis/inducido químicamente , Trombosis/prevención & control
14.
PLoS Negl Trop Dis ; 9(6): e0003869, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26110417

RESUMEN

BACKGROUND: The saliva of blood-feeding arthropods contains a notable diversity of molecules that target the hemostatic and immune systems of the host. Dipetalodipin and triplatin are triatomine salivary proteins that exhibit high affinity binding to prostanoids, such as TXA2, thus resulting in potent inhibitory effect on platelet aggregation in vitro. It was recently demonstrated that platelet-derived TXA2 mediates the formation of neutrophil extracellular traps (NETs), a newly recognized link between inflammation and thrombosis that promote thrombus growth and stability. METHODOLOGY/PRINCIPAL FINDINGS: This study evaluated the ability of dipetalodipin and triplatin to block NETs formation in vitro. We also investigated the in vivo antithrombotic activity of TXA2 binding proteins by employing two murine models of experimental thrombosis. Remarkably, we observed that both inhibitors abolished the platelet-mediated formation of NETs in vitro. Dipetalodipin and triplatin significantly increased carotid artery occlusion time in a FeCl3-induced injury model. Treatment with TXA2-binding proteins also protected mice from lethal pulmonary thromboembolism evoked by the intravenous injection of collagen and epinephrine. Effective antithrombotic doses of dipetalodipin and triplatin did not increase blood loss, which was estimated using the tail transection method. CONCLUSIONS/SIGNIFICANCE: Salivary TXA2-binding proteins, dipetalodipin and triplatin, are capable to prevent platelet-mediated NETs formation in vitro. This ability may contribute to the antithrombotic effects in vivo. Notably, both molecules inhibit arterial thrombosis without promoting excessive bleeding. Our results provide new insight into the antihemostatic effects of TXA2-binding proteins and may have important significance in elucidating the mechanisms of saliva to avoid host's hemostatic responses and innate immune system.


Asunto(s)
Insectos Vectores/metabolismo , Inhibidores de Agregación Plaquetaria/farmacología , Proteínas y Péptidos Salivales/farmacología , Trombosis/prevención & control , Tromboxano A2/metabolismo , Triatominae/metabolismo , Animales , Proteínas de Artrópodos/metabolismo , Proteínas de Artrópodos/farmacología , Plaquetas/efectos de los fármacos , Enfermedad de Chagas/transmisión , Trampas Extracelulares/efectos de los fármacos , Trampas Extracelulares/fisiología , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Neutrófilos/efectos de los fármacos , Agregación Plaquetaria/efectos de los fármacos , Inhibidores de Agregación Plaquetaria/metabolismo , Unión Proteica/efectos de los fármacos , Proteínas Recombinantes , Proteínas y Péptidos Salivales/metabolismo
15.
Acta Crystallogr F Struct Biol Commun ; 71(Pt 6): 643-9, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26057788

RESUMEN

Secreted protein components of hookworm species include a number of representatives of the cysteine-rich/antigen 5/pathogenesis-related 1 (CAP) protein family known as Ancylostoma-secreted proteins (ASPs). Some of these have been considered as candidate antigens for the development of vaccines against hookworms. The functions of most CAP superfamily members are poorly understood, but one form, the hookworm platelet inhibitor (HPI), has been isolated as a putative antagonist of the platelet integrins αIIbß3 and α2ß1. Here, the crystal structure of HPI is described and its structural features are examined in relation to its possible function. The HPI structure is similar to those of other ASPs and shows incomplete conservation of the sequence motifs CAP1 and CAP2 that are considered to be diagnostic of CAP superfamily members. The asymmetric unit of the HPI crystal contains a dimer with an extensive interaction interface, but chromatographic measurements indicate that it is primarily monomeric in solution. In the dimeric structure, the putative active-site cleft areas from both monomers are united into a single negatively charged depression. A potential Lys-Gly-Asp disintegrin-like motif was identified in the sequence of HPI, but is not positioned at the apex of a tight turn, making it unlikely that it interacts with the integrin. Recombinant HPI produced in Escherichia coli was found not to inhibit the adhesion of human platelets to collagen or fibrinogen, despite having a native structure as shown by X-ray diffraction. This result corroborates previous analyses of recombinant HPI and suggests that it might require post-translational modification or have a different biological function.


Asunto(s)
Ancylostoma/química , Plaquetas/efectos de los fármacos , Adhesión Celular/efectos de los fármacos , Proteínas del Helminto/química , Secuencias de Aminoácidos , Ancylostoma/metabolismo , Animales , Plaquetas/química , Dominio Catalítico , Colágeno/química , Colágeno/metabolismo , Cristalografía por Rayos X , Escherichia coli/genética , Escherichia coli/metabolismo , Fibrinógeno/química , Fibrinógeno/metabolismo , Expresión Génica , Proteínas del Helminto/genética , Proteínas del Helminto/metabolismo , Proteínas del Helminto/farmacología , Humanos , Enlace de Hidrógeno , Integrina alfa2beta1/química , Integrina alfa2beta1/metabolismo , Modelos Moleculares , Datos de Secuencia Molecular , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/química , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/metabolismo , Multimerización de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Electricidad Estática
16.
PLoS Pathog ; 10(9): e1004338, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25211214

RESUMEN

BACKGROUND: Invasion of mosquito salivary glands (SGs) by Plasmodium falciparum sporozoites is an essential step in the malaria life cycle. How infection modulates gene expression, and affects hematophagy remains unclear. PRINCIPAL FINDINGS: Using Affimetrix chip microarray, we found that at least 43 genes are differentially expressed in the glands of Plasmodium falciparum-infected Anopheles gambiae mosquitoes. Among the upregulated genes, one codes for Agaphelin, a 58-amino acid protein containing a single Kazal domain with a Leu in the P1 position. Agaphelin displays high homology to orthologs present in Aedes sp and Culex sp salivary glands, indicating an evolutionarily expanded family. Kinetics and surface plasmon resonance experiments determined that chemically synthesized Agaphelin behaves as a slow and tight inhibitor of neutrophil elastase (K(D) ∼ 10 nM), but does not affect other enzymes, nor promotes vasodilation, or exhibit antimicrobial activity. TAXIscan chamber assay revealed that Agaphelin inhibits neutrophil chemotaxis toward fMLP, affecting several parameter associated with cell migration. In addition, Agaphelin reduces paw edema formation and accumulation of tissue myeloperoxidase triggered by injection of carrageenan in mice. Agaphelin also blocks elastase/cathepsin-mediated platelet aggregation, abrogates elastase-mediated cleavage of tissue factor pathway inhibitor, and attenuates neutrophil-induced coagulation. Notably, Agaphelin inhibits neutrophil extracellular traps (NETs) formation and prevents FeCl3-induced arterial thrombosis, without impairing hemostasis. CONCLUSIONS: Blockade of neutrophil elastase emerges as a novel antihemostatic mechanism in hematophagy; it also supports the notion that neutrophils and the innate immune response are targets for antithrombotic therapy. In addition, Agaphelin is the first antihemostatic whose expression is induced by Plasmodium sp infection. These results suggest that an important interplay takes place in parasite-vector-host interactions.


Asunto(s)
Anopheles/parasitología , Hemostasis/fisiología , Interacciones Huésped-Parásitos , Proteínas de Insectos/metabolismo , Neutrófilos/inmunología , Plasmodium falciparum/patogenicidad , Proteínas y Péptidos Salivales/metabolismo , Trombosis/prevención & control , Secuencia de Aminoácidos , Animales , Anopheles/metabolismo , Dicroismo Circular , Edema/etiología , Edema/metabolismo , Edema/prevención & control , Femenino , Proteínas de Insectos/química , Proteínas de Insectos/genética , Insectos Vectores , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Glándulas Salivales/metabolismo , Glándulas Salivales/parasitología , Proteínas y Péptidos Salivales/química , Proteínas y Péptidos Salivales/genética , Homología de Secuencia de Aminoácido , Resonancia por Plasmón de Superficie
17.
PLoS One ; 9(9): e107295, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25207644

RESUMEN

Salivary gland homogenate (SGH) from the female mosquitoes Anopheles gambiae, An. stephensi, An. freeborni, An. dirus and An. albimanus were found to exhibit hemagglutinating (lectin) activity. Lectin activity was not found for male An. gambiae, or female Ae aegypti, Culex quinquefasciatus, Phlebotomus duboscqi, and Lutzomyia longipalpis. With respect to species-specificity, An. gambiae SGH agglutinates red blood cells (RBC) from humans, horse, sheep, goat, pig, and cow; it is less active for rats RBC, and not detectable for guinea-pigs or chicken RBC. Notably, lectin activity was inhibited by low concentrations of dextran sulfate 50-500 K, fucoidan, heparin, laminin, heparin sulfate proteoglycan, sialyl-containing glycans (e.g. 3'-sialyl Lewis X, and 6'-sialyl lactose), and gangliosides (e.g. GM3, GD1, GD1b, GTB1, GM1, GQ1B), but not by simple sugars. These results imply that molecule(s) in the salivary gland target sulfated glycans. SGH from An. gambiae was also found to promote agglutination of HL-60 cells which are rich in sialyl Lewis X, a glycan that decorates PSGL-1, the neutrophils receptor that interacts with endothelial cell P-selectin. Accordingly, SGH interferes with HL-60 cells adhesion to immobilized P-selectin. Because An. gambiae SGH expresses galectins, one member of this family (herein named Agalectin) was expressed in E. coli. Recombinant Agalectin behaves as a non-covalent homodimer. It does not display lectin activity, and does not interact with 500 candidates tested in a Glycan microarray. Gel-filtration chromatography of the SGH of An. gambiae identified a fraction with hemagglutinating activity, which was analyzed by 1D PAGE followed by in-gel tryptic digestion, and nano-LC MS/MS. This approach identified several genes which emerge as candidates for a lectin targeting sulfated glycans, the first with this selectivity to be reported in the SGH of a blood-sucking arthropod. The role of salivary molecules (sialogenins) with lectin activity is discussed in the context of inflammation, and parasite-vector-host interactions.


Asunto(s)
Anopheles/química , Proteínas de Insectos/química , Insectos Vectores/química , Lectinas/química , Polisacáridos/química , Glándulas Salivales/química , Aedes/química , Pruebas de Aglutinación , Secuencia de Aminoácidos , Animales , Mezclas Complejas/química , Culex/química , Eritrocitos/citología , Eritrocitos/efectos de los fármacos , Femenino , Gangliósidos/química , Gangliósidos/farmacología , Células HL-60 , Humanos , Proteínas Inmovilizadas/química , Proteínas de Insectos/aislamiento & purificación , Proteínas de Insectos/farmacología , Lectinas/aislamiento & purificación , Lectinas/farmacología , Masculino , Datos de Secuencia Molecular , Selectina-P/química , Phlebotomus/química , Unión Proteica , Psychodidae/química , Rumiantes , Especificidad de la Especie , Ésteres del Ácido Sulfúrico
18.
Alcohol Alcohol ; 49(3): 256-60, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24585043

RESUMEN

AIMS: The purpose of this study was to investigate the association between the metabotropic glutamate receptor 3 (GRM3) subunit gene and alcohol dependence by the single-nucleotide polymorphisms (SNPs). METHODS: Two hundred and forty-eight male alcohol-dependent patients and 235 male control subjects were recruited. Ten SNPs in the GRM3 region were studied, and genotyping of SNPs was performed by ligase detection reactions. RESULTS: We found highly significant differences in allele and genotype frequencies of rs6465084 between the alcohol-dependent and control group, with the greater frequency of A allele of SNP rs6465084 in alcohol-dependent group. We also found significant differences of haplotype frequencies in five combinations (including TAATATT, CAGTATT, TCGTATT, CAATAGC, TAATATC) in the linkage disequilibrium constructed by seven SNPs between the groups. CONCLUSION: Our results supplied the first evidence that the polymorphism of GRM3 gene associates with the morbidity of alcohol dependence in human being, which may support a new potential target for alcoholism treatment.


Asunto(s)
Alcoholismo/genética , Predisposición Genética a la Enfermedad/genética , Polimorfismo de Nucleótido Simple/genética , Receptores de Glutamato Metabotrópico/genética , Adolescente , Adulto , Pueblo Asiatico/genética , Estudios de Casos y Controles , Frecuencia de los Genes , Genotipo , Haplotipos , Humanos , Desequilibrio de Ligamiento/genética , Masculino , Persona de Mediana Edad , Adulto Joven
19.
PLoS One ; 9(2): e87140, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24586264

RESUMEN

BACKGROUND: The role of intracellular radical oxygen species (ROS) in pathogenesis of cerebral malaria (CM) remains incompletely understood. METHODS AND FINDINGS: We undertook testing Tempol--a superoxide dismutase (SOD) mimetic and pleiotropic intracellular antioxidant--in cells relevant to malaria pathogenesis in the context of coagulation and inflammation. Tempol was also tested in a murine model of CM induced by Plasmodium berghei Anka infection. Tempol was found to prevent transcription and functional expression of procoagulant tissue factor in endothelial cells (ECs) stimulated by lipopolysaccharide (LPS). This effect was accompanied by inhibition of IL-6, IL-8, and monocyte chemoattractant protein (MCP-1) production. Tempol also attenuated platelet aggregation and human promyelocytic leukemia HL60 cells oxidative burst. In dendritic cells, Tempol inhibited LPS-induced production of TNF-α, IL-6, and IL-12p70, downregulated expression of co-stimulatory molecules, and prevented antigen-dependent lymphocyte proliferation. Notably, Tempol (20 mg/kg) partially increased the survival of mice with CM. Mechanistically, treated mice had lowered plasma levels of MCP-1, suggesting that Tempol downmodulates EC function and vascular inflammation. Tempol also diminished blood brain barrier permeability associated with CM when started at day 4 post infection but not at day 1, suggesting that ROS production is tightly regulated. Other antioxidants-such as α-phenyl N-tertiary-butyl nitrone (PBN; a spin trap), MnTe-2-PyP and MnTBAP (Mn-phorphyrin), Mitoquinone (MitoQ) and Mitotempo (mitochondrial antioxidants), M30 (an iron chelator), and epigallocatechin gallate (EGCG; polyphenol from green tea) did not improve survival. By contrast, these compounds (except PBN) inhibited Plasmodium falciparum growth in culture with different IC50s. Knockout mice for SOD1 or phagocyte nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (gp91(phox-/-)) or mice treated with inhibitors of SOD (diethyldithiocarbamate) or NADPH oxidase (diphenyleneiodonium) did not show protection or exacerbation for CM. CONCLUSION: Results with Tempol suggest that intracellular ROS contribute, in part, to CM pathogenesis. Therapeutic targeting of intracellular ROS in CM is discussed.


Asunto(s)
Antioxidantes/farmacología , Óxidos N-Cíclicos/farmacología , Células Dendríticas/efectos de los fármacos , Células Dendríticas/metabolismo , Malaria Cerebral/tratamiento farmacológico , Tromboplastina/metabolismo , Animales , Antioxidantes/uso terapéutico , Células Cultivadas , Quimiocina CCL2/metabolismo , Óxidos N-Cíclicos/uso terapéutico , Ensayo de Inmunoadsorción Enzimática , Humanos , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Malaria Cerebral/metabolismo , Ratones , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Marcadores de Spin
20.
Blood ; 122(25): 4094-106, 2013 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-24159172

RESUMEN

The identity of vampire bat saliva anticoagulant remained elusive for almost a century. Sequencing the salivary gland genes from the vampire bat Desmodus rotundus identified Desmolaris as a novel 21.5-kDa naturally deleted (Kunitz 1-domainless) form of tissue factor pathway inhibitor. Recombinant Desmolaris was expressed in HEK293 cells and characterized as a slow, tight, and noncompetitive inhibitor of factor (F) XIa by a mechanism modulated by heparin. Desmolaris also inhibits FXa with lower affinity, independently of protein S. In addition, Desmolaris binds kallikrein and reduces bradykinin generation in plasma activated with kaolin. Truncated and mutated forms of Desmolaris determined that Arg32 in the Kunitz-1 domain is critical for protease inhibition. Moreover, Kunitz-2 and the carboxyl-terminus domains mediate interaction of Desmolaris with heparin and are required for optimal inhibition of FXIa and FXa. Notably, Desmolaris (100 µg/kg) inhibited FeCl3-induced carotid artery thrombus without impairing hemostasis. These results imply that FXIa is the primary in vivo target for Desmolaris at antithrombotic concentrations. Desmolaris also reduces the polyphosphate-induced increase in vascular permeability and collagen- and epinephrine-mediated thromboembolism in mice. Desmolaris emerges as a novel anticoagulant targeting FXIa under conditions in which the coagulation activation, particularly the contact pathway, plays a major pathological role.


Asunto(s)
Anticoagulantes/química , Anticoagulantes/farmacología , Quirópteros , Inhibidores del Factor Xa , Proteínas y Péptidos Salivales/química , Proteínas y Péptidos Salivales/farmacología , Trombosis/tratamiento farmacológico , Animales , Bradiquinina/química , Bradiquinina/genética , Bradiquinina/metabolismo , Cloruros/efectos adversos , Cloruros/farmacología , Modelos Animales de Enfermedad , Factor Xa/química , Factor Xa/genética , Factor Xa/metabolismo , Compuestos Férricos/efectos adversos , Compuestos Férricos/farmacología , Células HEK293 , Humanos , Inflamación/tratamiento farmacológico , Inflamación/genética , Inflamación/metabolismo , Calicreínas/química , Calicreínas/genética , Calicreínas/metabolismo , Ratones , Noxas/efectos adversos , Noxas/farmacología , Estructura Terciaria de Proteína , Proteínas y Péptidos Salivales/genética , Trombosis/inducido químicamente , Trombosis/genética , Trombosis/metabolismo
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