Intracellular Interactions Between Arboviruses and Wolbachia in Aedes aegypti

Aedes aegypti is inherently susceptible to arboviruses. The geographical expansion of this vector host species has led to the persistence of Dengue, Zika, and Chikungunya human infections. These viruses take advantage of the mosquito’s cell to create an environment conducive for their growth. Arboviral infection triggers transcriptomic and protein dysregulation in Ae. aegypti and in effect, host antiviral mechanisms are compromised. Currently, there are no existing vaccines able to protect human hosts from these infections and thus, vector control strategies such as Wolbachia mass release program is regarded as a viable option. Considerable evidence demonstrates how the presence of Wolbachia interferes with arboviruses by decreasing host cytoskeletal proteins and lipids essential for arboviral infection. Also, Wolbachia strengthens host immunity, cellular regeneration and causes the expression of microRNAs which could potentially be involved in virus inhibition. However, variation in the magnitude of Wolbachia’s pathogen blocking effect that is not due to the endosymbiont’s density has been recently reported. Furthermore, the cellular mechanisms involved in this phenotype differs depending on Wolbachia strain and host species. This prompts the need to explore the cellular interactions between Ae. aegypti-arboviruses-Wolbachia and how different Wolbachia strains overall affect the mosquito’s cell. Understanding what happens at the cellular and molecular level will provide evidence on the sustainability of Wolbachia vector control

Los alumnos de los primeros cursos ¿asocian el concepto de elemento a sustancias y objetos de la vida cotidiana?

El conocimiento aplicado ha modificado las formas de vida y la comunicación de las personas, los alumnos para su desarrollo personal y social deben estrechar la brecha entre la educación y el entorno cotidiano.En investigaciones anteriores realizadas con alumnos del curso de Química I del Departamento de Ciencias Naturales, hemos indagado por qué algunos contenidos que están en los diseños curriculares de todos los trayectos formativos, no aparecen como significativos en los estudiantes. En esta oportunidad nos proponemos indagar si los alumnos relacionan los elementos químicos con objetos y sustancias usuales.En el marco de una metodología cualitativa, se diseñaron una serie de etapas para encontrar argumentos que permitan averiguar si el estudio de los elementos químicos tiene alguna conexión con el entorno próximo de los estudiantes.En primer lugar se buscó información en los docentes del nivel secundario indagando, mediante encuestas, cómo y cuándo aborda esos contenidos básicos y qué considera importante cuando enseñan esos temas. Luego se planteó una actividad para que cada alumno y en forma individual precise sus ideas sobre estos contenidos.La investigación nos indica que el estudio y manejo de los elementos químicos, por varias razones, es un tema pendiente para los alumnos porque no los encuentran cercanos a ellos. Es interesante también destacar que en varios objetos elegidos mencionan el mismo elemento químico y en la composición de los objetos seleccionados el elemento indicado no es el componente habitual, por ejemplo “una pava de plata”. Creemos que es importante realizar un cambio, modificando las estrategias de enseñanza, evitando el aprendizaje repetitivo y asegurando la conexión entre los nuevos aprendizajes y los conocimientos previos, procurando que los contenidos sean potencialmente significativos

Assessment of plasma chitotriosidase activity, CCL18/PARC concentration and NP-C suspicion index in the diagnosis of Niemann-Pick disease type C: A prospective observational study

Background: Niemann-Pick disease type C (NP-C) is a rare, autosomal recessive neurodegenerative disease caused by mutations in either the NPC1 or NPC2 genes. The diagnosis of NP-C remains challenging due to the non-specific, heterogeneous nature of signs/symptoms. This study assessed the utility of plasma chitotriosidase (ChT) and Chemokine (C-C motif) ligand 18 (CCL18)/pulmonary and activation-regulated chemokine (PARC) in conjunction with the NP-C suspicion index (NP-C SI) for guiding confirmatory laboratory testing in patients with suspected NP-C. Methods: In a prospective observational cohort study, incorporating a retrospective determination of NP-C SI scores, two different diagnostic approaches were applied in two separate groups of unrelated patients from 51 Spanish medical centers (n = 118 in both groups). From Jan 2010 to Apr 2012 (Period 1), patients with =2 clinical signs/symptoms of NP-C were considered ''suspected NP-C'' cases, and NPC1/NPC2 sequencing, plasma chitotriosidase (ChT), CCL18/PARC and sphingomyelinase levels were assessed. Based on findings in Period 1, plasma ChT and CCL18/PARC, and NP-C SI prediction scores were determined in a second group of patients between May 2012 and Apr 2014 (Period 2), and NPC1 and NPC2 were sequenced only in those with elevated ChT and/or elevated CCL18/PARC and/or NP-C SI =70. Filipin staining and 7-ketocholesterol (7-KC) measurements were performed in all patients with NP-C gene mutations, where possible. Results: In total across Periods 1 and 2, 10/236 (4%) patients had a confirmed diagnosis o NP-C based on gene sequencing (5/118 4.2%] in each Period): all of these patients had two causal NPC1 mutations. Single mutant NPC1 alleles were detected in 8/236 (3%) patients, overall. Positive filipin staining results comprised three classical and five variant biochemical phenotypes. No NPC2 mutations were detected. All patients with NPC1 mutations had high ChT activity, high CCL18/PARC concentrations and/or NP-C SI scores =70. Plasma 7-KC was higher than control cut-off values in all patients with two NPC1 mutations, and in the majority of patients with single mutations. Family studies identified three further NP-C patients. Conclusion: This approach may be very useful for laboratories that do not have mass spectrometry facilities and therefore, they cannot use other NP-C biomarkers for diagnosis

Secretory group V phospholipase A2 regulates acute lung injury and neutrophilic inflammation caused by LPS in mice

We investigated the regulatory role of 14-kDa secretory group V phospholipase A2 (gVPLA2) in the development of acute lung injury (ALI) and neutrophilic inflammation (NI) caused by intratracheal administration of LPS. Experiments were conducted in gVPLA2 knockout (pla2g5−/−) mice, which lack the gene, and gVPLA2 wild-type littermate control (pla2g5+/+) mice. Indices of pulmonary injury were evaluated 24 h after intratracheal administration of LPS. Expression of gVPLA2 in microsections of airways and mRNA content in lung homogenates were increased substantially in pla2g5+/+ mice after LPS-administered compared with saline-treated pla2g5+/+ mice. By contrast, expression of gVPLA2 was neither localized in LPS- nor saline-treated pla2g5−/− mice. LPS also caused 1) reduced transthoracic static compliance, 2) lung edema, 3) neutrophilic infiltration, and 4) increased neutrophil myeloperoxidase activity in pla2g5+/+ mice. These events were attenuated in pla2g5−/− mice exposed to LPS or in pla2g5+/+ mice receiving MCL-3G1, a neutralizing MAb directed against gVPLA2, before LPS administration. Our data demonstrate that gVPLA2 is an inducible protein in pla2g5+/+ mice but not in pla2g5−/− mice within 24 h after LPS treatment. Specific inhibition of gVPLA2 with MCL-3G1 or gene-targeted mice lacking gVPLA2 blocks ALI and attenuates NI caused by LPS

Group V Phospholipase A2 Mediates Barrier Disruption of Human Pulmonary Endothelial Cells Caused by LPS In Vitro

We examined the functional role of 14-kD secretory group V phospholipase A2 (gVPLA2) on the barrier function of pulmonary endothelial cells (ECs) after LPS activation in vitro. Expression of gVPLA2 was elicited by 20 ng/ml LPS as demonstrated by increased (1) mRNA, (2) protein content, and (3) cell surface expression of gVPLA2 within 4 hours. The effect of LPS on EC barrier function was measured by transendothelial monolayer electrical resistance (TER). LPS increased permeability across EC monolayers at 2–3 hours, and was sustained for 10 hours or more. Blockade of gVPLA2 with mouse monoclonal 3G1 (MCL-3G1) monoclonal antibody directed against gVPLA2 inhibited EC barrier dysfunction elicited by LPS in a time- and concentration-dependent manner; control IgG had no effect on TER. Like LPS, exogenous gVPLA2 caused increased EC permeability in a time- and concentration-dependent manner; neither gIIaPLA2, a close homolog of gVPLA2, nor W31A, an inactive mutant of gVPLA2, caused a decrease in EC TER. Immunofluorescence analysis revealed comparable F-actin stress fiber and intercellular gap formation for ECs treated with either gVPLA2 or LPS. Treatment with gVPLA2 disrupted vascular endothelial–cadherin junctional complexes on ECs. Coincubation of ECs with MCL-3G1 substantially attenuated the structural changes caused by gVPLA2 or LPS. We demonstrate that (1) gVPLA2 is constitutively expressed in ECs and is up-regulated after LPS activation, (2) endogenously secreted gVPLA2 from ECs after LPS increases EC permeability through F-actin and junctional complex rearrangement, and (3) inhibition of endogenous gVPLA2 from ECs is sufficient to block disruption of the EC barrier function after LPS in vitro

Cytosolic group IVa phospholipase A₂mediates IL-8/CXCL8-induced transmigration of human polymorphonuclear leukocytes <it>in vitro</it>

Abstract Background Cytosolic gIVaPLA2 is a critical enzyme in the generation of arachidonate metabolites and in induction of β2-integrin adhesion in granulocytes. We hypothesized that gIVaPLA2 activation also is an essential downstream step for post adhesive migration of PMN in vitro. Methods Migration of PMNs caused by IL-8/CXCL8 was assessed using a transwell migration chamber. PMNs were pretreated with two structurally unrelated inhibitors of gIVaPLA2, arachidonyl trifluoromethylketone (TFMK) or pyrrophenone, prior to IL-8/CXCL8 exposure. The fraction of migrated PMNs present in the lower chamber was measured as total myeloperoxidase content. GIVaPLA2 enzyme activity was analyzed using [14C-PAPC] as specific substrate F-actin polymerization and cell structure were examined after rhodamine-phalloidin staining. Results IL-8/CXCL8-induced migration of PMNs was elicited in concentration- and time-dependent manner. Time-related phosphorylation and translocation of cytosolic gIVaPLA2 to the nucleus was observed for PMNs stimulated with IL-8/CXCL8 in concentration sufficient to cause upstream phosphorylation of MAPKs (ERK-1/2 and p38) and Akt/PKB. Inhibition of gIVaPLA2 corresponded to the magnitude of blockade of PMN migration. Neither AA nor LTB4 secretion was elicited following IL-8/CXCL8 activation. In unstimulated PMNs, F-actin was located diffusely in the cytosol; however, a clear polarized morphology with F-actin-rich ruffles around the edges of the cell was observed after activation with IL-8/CXCL8. Inhibition of gIVaPLA2 blocked change in cell shape and migration caused by IL-8/CXCL8 but did not cause F-actin polymerization or translocation of cytosolic F-actin to inner leaflet of the PMN membrane. Conclusion We demonstrate that IL-8/CXCL8 causes a) phosphorylation and translocation of cytosolic gIVaPLA2 to the nucleus, b) change in cell shape, c) polymerization of F-actin, and d) chemoattractant/migration of PMN in vitro. Inhibition of gIVaPLA2 blocks the deformability and subsequent migration of PMNs caused by IL-8/CXCL8. Our data suggest that activation of gIVaPLA2 is an essential step in PMN migration in vitro.</p

Echocardiometric evaluation of cardiovascular abnormalities in Marfan syndrome

Marfan syndrome is an inherited disorder of connective tissue with manifestations in various organ-systems including cardiovascular system. The aim of this study was to characterize and determine the frequency of cardiovascular alterations by echocardiography in 2 age cohorts of Mexican patients with Marfan syndrome and their comparisons with control groups. Material and methods: Sixty six with Marfan syndrome and 33 control patients were evaluated by echocardiography. Segments of the aorta and pulmonary artery were measured at different levels, cardiac valves were examined for prolapse and the interatrial septum was assessed for septal aneurysm. Numeric values were corrected forthe body surface area and compared with the control group. Results: Mean significant values between group I (children) and Group II (adults) were as follows: aortic annulus 16.62 ± 4.57 mm/m² vs 12.81 ± 1.95 (p< 0.001), aortic root 23.30 ±7.49 mm/m²vs 18.36 ± 2.97 (p < 0.001), sinuses of Valsalva 24.14 ± 7.29 mm/m² vs 19.84 ± 3.59 (p < 0.001), ascending aorta 18.43 ± 5.90 mm/m² vs 17.02 ± 4.79 (p < 0.001), aortic arch 16.12 ± 4.73 mm/m² vs 14.20 ± 2.68 (p < 0.001). Pulmonary valve prolapse was seen in 10/22 (45.5%) vs 7/44 (15.9%), p < 0.03. Interatrial septal aneurysm was found in 3/22 (13.6%) vs 20/44 (45.5%), p < 0.03. There was a significative diference in the presence of atrial septal aneurysm between the adult group and control group (p < 0.001). Conclusions: The incidence of cardiovascular abnormalities in our series is similar to that in the literature with the exception of the very high incidence of pulmonary valve prolapse vs control groups, then it suggests that the clinical manifestations of MFS are strikingly severe in the Mexican population. Also a high incidence of interatrial septal aneurysm (34.9%) in comparison to control groups (18.2%) was found