Current and future trends in neoadjuvant immunotherapy for the treatment of triple-negative breast cancer.

Triple-negative breast cancer (TNBC) comprises 15-20% of all breast cancers (BC). Lacking targeted therapy options, TNBC becomes the focal point of clinical investigations aiming not only to identify drugs with enhanced response potential but also to uncover new immunological and/or metabolic pathways conducive to more effective treatments. Currently, neoadjuvant treatment for TNBC relies on standard chemotherapy in conjunction with immunotherapy, given the improved response observed with this drug combination. This review delves into the latest therapeutic updates in TNBC treatment and explores potential advancements shaping the future landscape of this disease in the neoadjuvant setting.

Estrategia metodológica para la prevención de los problemas de salud bucal en la educación primaria

Introducción: Las transformaciones que se evidencian en la sociedad, hace que surjan, en las instituciones educativas, exigencias referidas a la preparación de los profesionales para enfrentar los nuevos desafíos y lograr ciudadanos con una formación integral y responsables con el cuidado de su salud. Ahí es donde ocupan un lugar privilegiado los aspectos relacionados con la prevención de los problemas de salud bucal en la educación primaria. Objetivo: Diseñar una estrategia metodológica para la prevención de los problemas de salud bucal en la educación primaria. Materiales y métodos: La estrategia fue diseñada en cuatro etapas: diagnóstico, planeación, instrumentación, y control y evaluación. Para su elaboración se consideró el diagnóstico realizado en el curso escolar 2021-2022 a tres escuelas primarias pertenecientes al municipio Matanzas. Se definió la variable fundamental de la investigación y, a partir de su operacionalización, se establecieron las dimensiones e indicadores. Se aplicaron métodos del nivel teórico y empírico del conocimiento, así como métodos estadísticos. Resultados: Se evidencian limitadas acciones de preparación metodológica que inciden en el tratamiento a la prevención de los problemas de salud bucal desde el contexto escolar. Para transformar los resultados obtenidos se diseñó la estrategia metodológica. Conclusiones: El diseño de la estrategia metodológica revela una manera novedosa de organizar y realizar actividades en el sistema de trabajo metodológico de la escuela primaria, para contribuir a la preparación metodológica del maestro primario en la temática.

Introduction: The transformations that are evident in society cause to arise, in educational institutions, demands regarding to the training of professionals to face the new challenges and achieve citizens with comprehensive training and responsible with the care of their health. That is where aspects related to the prevention of oral health problems in primary education occupy a privileged place. Objective: To design a methodological strategy for the prevention of oral health problems in primary education. Materials and methods: The strategy was designed in four stages: diagnosis, planning, implementation; and evaluation and control. For its elaboration, the diagnosis carried out during the 2021-2022 school year in three primary schools belonging to the municipality of Matanzas was considered. The fundamental variable of the research was defined and the dimensions and indicators were established, on the basis of its operationalization. Methods of the theoretical and empirical level of knowledge were applied, as well as statistical methods. Results: It is evidenced that methodological preparation actions that have repercussion on the prevention of oral health problems from the school context are not enough. To transform the results obtained, the methodological strategy was designed. Conclusions: The design of the methodological strategy reveals a new way of organizing and carrying out activities in the methodological work system of the primary school, to contribute to the methodological preparation of primary teacher on the topic.

[Ethiology, risk factors and Whole blood viscosity index in thromboembolic venous disease]. / Etiología, factores de riesgo e Índice de viscosidad sanguíneo total en enfermedad tromboembólica venosa.

Backround: Venous thromboembolic disease (VTED) is a frequent cause of hospitalization and mortality. Whole blood viscosity (WBV) participates in the pathogenesis of thrombosis. Objective: To identify the most frequent etiologies and their association with WBV index (WBVI) in hospitalized patients with VTED. Material and methods: Observational, cross-sectional, retrospective, analytical study, Group 1: cases (patients diagnosed with VTED) and Group 2: controls without thrombosis. Risk factors for VTED were described and WBVI was calculated from total proteins and hematocrit. Descriptive and inferential statistics were used with Chi-squared test, Fisher's exact test, Mann Whitney U test, bivariate and multivariate logistic regression analysis. Results: We included 146 patients and 148 controls, age 46.3 ±17.7 vs. 58 ± 18.2 years, of both sexes (female, 65.1%). The most frequent etiology was neoplastic (23.3%), followed by diseases with cardiovascular risk (17.8%). Independent risk factors for VTED were age, chronic kidney disease, presence of liver disease or solid neoplasia. WBVI was similar in patients with VTED as in those without thrombosis. We found an association of the presence of deep vein thrombosis and diseases with cardiovascular risk (p = 0.040). Conclusions: The presence of chronic kidney disease, liver disease, and solid neoplasia are independent risk factors for VTED. The WBVI is a simple and rapid diagnostic tool in the evaluation of patients with VTED.

Introducción: la enfermedad tromboembólica venosa (ETEV) es causa frecuente de hospitalización y mortalidad. La viscosidad sanguínea participa en la patogénesis de la trombosis. Objetivo: analizar los factores de riesgo y el índice de viscosidad sanguíneo total (IVTS) en pacientes con ETEV. Material y métodos: estudio observacional, transversal, retrospectivo, analítico. Grupo 1: casos (pacientes con diagnóstico de ETEV), y grupo 2: controles sin trombosis. Se describieron los factores de riesgo para ETEV y se calculó el IVTS a partir de proteínas totales y hematocrito. Se utilizó estadística descriptiva e inferencial con prueba de Chi cuadrada, prueba exacta de Fisher, U de Mann Whitney, análisis de regresión logística bivariado y multivariado. Resultados: incluimos 146 pacientes y 148 controles, edad 46.3 ± 17.7 frente a 58 ± 18.2 años, de ambos sexos, femenino (65.1%). La etiología más frecuente fue la neoplásica (23.3%), seguida de la enfermedad con riesgo cardiovascular (17.8%). Los factores de riesgo independientes para ETEV fueron: edad, enfermedad renal crónica, presencia de hepatopatía o neoplasia sólida. El IVTS fue similar en los pacientes con ETEV que en aquellos sin trombosis. Se encontró asociación de la presencia de trombosis venosa profunda y enfermedades con riesgo cardiovascular (p = 0.040). Conclusiones: la presencia de ERC, hepatopatía y neoplasia sólida son factores de riesgo independientes para ETEV. El IVTS es un instrumento diagnóstico sencillo y rápido en la evaluación de los pacientes con ETEV.

Probing the Conformational States of Thimet Oligopeptidase in Solution.

Thimet oligopeptidase (TOP) is a metallopeptidase involved in the metabolism of oligopeptides inside and outside cells of various tissues. It has been proposed that substrate or inhibitor binding in the TOP active site induces a large hinge-bending movement leading to a closed structure, in which the bound ligand is enclosed. The main goal of the present work was to study this conformational change, and fluorescence techniques were used. Four active TOP mutants were created, each equipped with a single-Trp residue (fluorescence donor) and a p-nitro-phenylalanine (pNF) residue as fluorescence acceptor at opposite sides of the active site. pNF was biosynthetically incorporated with high efficiency using the amber codon suppression technology. Inhibitor binding induced shorter Donor-Acceptor (D-A) distances in all mutants, supporting the view that a hinge-like movement is operative in TOP. The activity of TOP is known to be dependent on the ionic strength of the assay buffer and D-A distances were measured at different ionic strengths. Interestingly, a correlation between the D-A distance and the catalytic activity of TOP was observed: the highest activities corresponded to the shortest D-A distances. In this study for the first time the hinge-bending motion of a metallopeptidase in solution could be studied, yielding insight about the position of the equilibrium between the open and closed conformation. This information will contribute to a more detailed understanding of the mode of action of these enzymes, including therapeutic targets like neurolysin and angiotensin-converting enzyme 2 (ACE2).

La prevención de los problemas de salud bucal: una visión desde la educación primaria

RESUMEN Introducción: la prevención, desde la escuela, debe facilitar una visión anticipadora que en la práctica se revierta en iniciativas en el proceso pedagógico, a partir de la participación de su colectivo, logrando modificaciones en la conducta de las personas para una mejor calidad de vida. Asimismo, propiciar la armonía entre las formas de pensar, sentir y actuar en el desarrollo del infante, y de manera activa contribuir a edificar el proyecto social deseado. Objetivo: describir el estado actual de los conocimientos, procedimientos y comportamientos, para prevenir los problemas de salud bucal en escolares de la Escuela Primaria José María Heredia de Heredia, del municipio de Matanzas. Materiales y métodos: se realizó un diagnóstico sobre los conocimientos, procedimientos y comportamientos que poseen los maestros para prever los problemas de salud bucal en escolares en la Escuela Primaria José María Heredia de Heredia, del municipio de Matanzas, entre los meses de febrero y abril de 2021. Resultados: se evidenció potencialidades e insuficiencias en la preparación del maestro primario para la prevención de los problemas de salud bucal. Conclusión: los conocimientos, procedimientos y comportamientos que poseen los maestros de esta institución educativa para precaver los problemas de salud bucal en sus escolares son insuficientes, y demuestran la necesidad de proponer acciones educativas dirigidas a solucionar esa insuficiencia.

ABSTRACT Introduction: prevention, from the school, should facilitate an anticipatory vision that in practice reverts to initiatives in the pedagogical process, based on the participation of its collective, leading to changes in the behavior of people for a better life quality. It also should propitiate harmony between the ways of thinking, feeling and behaving in the development of the child, and actively contribute to build the desired social project. Objective: to describe the current state of knowledge, procedures and behaviors to prevent oral health problems in schoolchildren at Jose Maria Heredia de Heredia Primary School, in the municipality of Matanzas. Materials and methods: a diagnostic was made on the knowledge, procedures and behaviors the teachers have to prevent oral health problems in schoolchildren at Jose Maria Heredia de Heredia Primary School, municipality of Matanzas, between the months of February and April 2021. Results: potentialities and insufficiencies were evidenced in the training of the primary teacher for the prevention of oral health problems. Conclusions: the knowledge, procedures and behaviors the teachers of this educational institution have to prevent oral health problems in their students are insufficient, and demonstrate the need of proposing educational actions aimed at solving this insufficiency.

El maestro primario y la prevención de los problemas bucales en escolares

RESUMEN La prevención de las enfermedades bucales es imprescindible desde las primeras etapas de la vida. Durante la niñez, junto con los padres, los maestros desempeñan un papel importante en el cuidado de la salud bucal. El trabajo tiene como objetivo mostrar el nivel de conocimiento que poseen los maestros primarios para la prevención de los problemas de salud bucal en escolares. Durante el mes de noviembre de 2021 se realizó una revisión bibliográfica en la que se utilizaron los descriptores: actitud, conocimiento, maestros y prevención, combinados con salud bucal. Se consultaron las bases de datos electrónicas Medline (vía PubMed), SciELO y Google Académico. La búsqueda no quedó restringida por idioma o país de origen de las publicaciones, pero sí tuvo como condición que los artículos fueran publicados en los últimos cinco años. Los maestros primarios son profesionales esenciales para prevenir problemas de salud bucal en los escolares, pero sus conocimientos sobre el tema son limitados.

ABSTRACT Prevention of oral diseases is indispensable since the first stages of life. During childhood, along with parents, teachers play an important role in oral health care. The aim of this work is showing the level of knowledge primary teachers have for the prevention of oral health problems in schoolchildren. A bibliographic review was carried out durin November 2021 using the following descriptors: attitude, knowledge, teachers and prevention, combined with oral health. Electronic database Medline (via PubMed), SciELO and Google Academic were consulted. The search was not restricted by language or country of origin of the publication, but it was conditioned to articles published in the last five years. Primary teachers are important professionals to prevent oral health problems in schoolchildren, but their knowledge on the subject is limited.

Generation and functional characterization of a single-chain variable fragment (scFv) of the anti-FGF2 3F12E7 monoclonal antibody.

Single-chain variable fragments (scFvs) are small-sized artificial constructs composed of the immunoglobulin heavy and light chain variable regions connected by a peptide linker. We have previously described an anti-fibroblast growth factor 2 (FGF2) immunoglobulin G (IgG) monoclonal antibody (mAb), named 3F12E7, with notable antitumor potential revealed by preclinical assays. FGF2 is a known angiogenesis-associated molecule implicated in tumor progression. In this report, we describe a recombinant scFv format for the 3F12E7 mAb. The results demonstrate that the generated 3F12E7 scFv, although prone to aggregation, comprises an active anti-FGF2 product that contains monomers and small oligomers. Functionally, the 3F12E7 scFv preparations specifically recognize FGF2 and inhibit tumor growth similar to the corresponding full-length IgG counterpart in an experimental model. In silico molecular analysis provided insights into the aggregation propensity and the antigen-recognition by scFv units. Antigen-binding determinants were predicted outside the most aggregation-prone hotspots. Overall, our experimental and prediction dataset describes an scFv scaffold for the 3F12E7 mAb and also provides insights to further engineer non-aggregated anti-FGF2 scFv-based tools for therapeutic and research purposes.

SARS-Cov-2, el virus emergente que causa la pandemia de COVID-19 / SARS-CoV-2, the emerging virus behind the COVID-19 pandemic

Resumen La emergencia del nuevo SARS-CoV-2 - y el reconocimiento de la enfermedad que produce como pandemia - constituye el evento sanitario de mayor importancia en 2020. Debido a su reciente aparición y la inexistencia de medicamentos o vacunas seguras y eficaces, el manejo de casos y el control de brotes de la enfermedad se hace difícil. En esta revisión, se expone información sobre la pandemia, las características del virus, las manifestaciones clínicas de la enfermedad, su adecuado diagnóstico, las alternativas de tratamiento y las acciones que se ejecutan para su control (AU).

Abstract The emergency of the novel coronavirus, and the recognition of the disease it causes as a pandemic, constitute the main sanitary event in 2020. Because its recent discovery and the lack of safe and effective drugs or vaccines, the managing of cases and the control of the pandemic is problematic. In this review, the authors summarize the basic characteristics of the pathogen, the signs and symptoms of disease, and the diagnosis tools to identify presence of the virus. Furthermore, we also review the current knowledge on the treatment of infected cases as well as information about vaccine candidates. We highlight actions executed in Cuba to control the pandemic (AU).

Revealing the Mode of Action of Halictine Antimicrobial Peptides: A Comprehensive Study with Model Membranes.

Antimicrobial peptides are innate host defense molecules with the ability to kill pathogens. They have been widely studied for their membrane lytic activity and their potential to overcome the ever-increasing threat of antimicrobial resistance against conventional antibiotics. Here, we focus on two halictines, antimicrobial peptides first obtained from the venom of the eusocial bee Halictus sexcinctus. The peptides, HAL-1 and HAL-2, are cationic (with +3 and +4 charges, respectively) and amphipathic, have 12 amino acid residues, and exhibit high biological activity. For this study, the mechanism of action of HAL-1 and HAL-2 was studied in detail using large and giant unilamellar vesicles composed of pure palmitoyl oleoyl phosphatidyl choline (POPC) and a mixture of POPC and the anionic lipid palmitoyl oleoyl phosphatidyl glycerol (POPG) as biomimetic models of the membranes of eukaryotes and microorganisms, respectively. A set of complementary techniques was put forward: carboxyfluorescein leakage assay, phase contrast optical microscopy, ζ-potential, static and dynamic light scattering, fluorescence and circular dichroism spectroscopies, and isothermal titration calorimetry. The results show that both halictines are able to interact strongly with anionic membranes: The interaction is exothermic and accompanied by structuring of the peptides as an α-helix and deep insertion into the membrane causing substantial membrane permeabilization at very low peptide/lipid molar ratios. Extensive vesicle aggregation was detected only at a high peptide concentration. On the other hand, the interaction of the halictines with POPC is significantly milder. Yet, the peptides were able to permeabilize the POPC membranes to some extent. Comparing both peptides, HAL-1 showed a somewhat stronger effect on model membranes. Fits to the data revealed apparent binding constants on the order of 103-104 M-1 for anionic membranes and 1 order of magnitude lower for zwitterionic bilayers. When lytic activity results were compared at the same bound peptide/lipid ratio, the halictines exhibited a higher activity toward zwitterionic membranes. As novel peptides, small and with powerful activity, these halictines are potential candidates for becoming antimicrobial agents.

Location of the Positive Charges in Cationic Amphiphiles Modulates Their Mechanism of Action against Model Membranes.

Synthetic cationic amphiphiles (CAms) with physicochemical properties similar to antimicrobial peptides are promising molecules in the search for alternative antibiotics to which pathogens cannot easily develop resistance. Here, we investigate two types of CAms based on tartaric acid and containing two hydrophobic chains (of 7 or 11 carbons) and two positive charges, located either at the end of the acyl chains (bola-like, B7 and B11) or at the tartaric acid backbone (gemini-like, G7 and G11). The interaction of the CAms with biomimetic membrane models (anionic and neutral liposomes) was studied with zeta potential and dynamic light scattering measurements, isothermal titration calorimetry, and a fluorescent-based leakage assay. We show that the type of molecule determines the mechanism of action of the CAms. Gemini-like molecules (G7 and G11) interact mainly via electrostatics (exothermic process) and reside in the external vesicle leaflet, altering substantially the vesicle surface potential but not causing significant membrane lysis. On the other hand, the interaction of bola-like CAms (B7 and B11) is endothermic and thus entropy-driven, and these molecules reach both membrane leaflets and cause substantial membrane permeabilization, likely after clustering of anionic lipids. The lytic ability is clearly higher against anionic membranes as compared with neutral membranes. Within each class of molecule, longer alkyl chains (i.e., B11 and G11) exhibit higher affinity and lytic ability. Overall, the molecule B11 exhibits a high potential as antimicrobial agent, since it has a high membrane affinity and causes substantial membrane permeabilization.

Glucose Homeostasis and Energy Balance in Children With Pseudohypoparathyroidism.

Context: Pseudohypoparathyroidism (PHP) is a rare genetic disorder characterized by early-onset obesity and multihormone resistance. To treat abnormal weight gain and prevent complications such as diabetes, we must understand energy balance and glucose homeostasis in PHP types 1A and 1B. Objective: The aim of this study was to evaluate food intake, energy expenditure, and glucose homeostasis in children with PHP. Design: Assessments included resting energy expenditure (REE), physical activity, food intake, sucrose preference, questionnaires, endocrine status, and auxological status. All patients underwent an oral glucose tolerance test (OGTT). Setting: Vanderbilt University Medical Center. Patients: We assessed 16 children with PHP1A, three with PHP1B, and 15 healthy controls. Main Outcome Measures: Food intake during an ad lib buffet meal and glucose at five time points during OGTT. Results: PHP1A and control groups were well matched. Participants with PHP1A had significantly lower REE without concomitant change in food intake or physical activity. At baseline, participants with PHP1A had significantly lower fasting glucose and insulin resistance. During OGTT, participants with PHP1A had significantly delayed peak glucose and a slower rate of glucose decline despite similar oral glucose insulin sensitivity. Participants with PHP1A had 0.46% lower HbA1c levels than controls from a clinic database after adjustment for OGTT 2-hour glucose. The PHP1B group was similar to the PHP1A group. Conclusions: In contrast to other monogenic obesity syndromes, our results support reduced energy expenditure, not severe hyperphagia, as the primary cause of abnormal weight gain in PHP. Patients with PHP are at high risk for dysglycemia without reduced insulin sensitivity.

HPV-16 E7 expression up-regulates phospholipase D activity and promotes rapamycin resistance in a pRB-dependent manner.

BACKGROUND: Human Papillomavirus (HPV) infection is the main risk factor for the development and progression of cervical cancer. HPV-16 E6 and E7 expression is essential for induction and maintenance of the transformed phenotype. These oncoproteins interfere with the function of several intracellular proteins, including those controlling the PI3K/AKT/mTOR pathway in which Phospolipase D (PLD) and Phosphatidic acid (PA) play a critical role. METHODS: PLD activity was measured in primary human keratinocytes transduced with retroviruses expressing HPV-16 E6, E7 or E7 mutants. The cytostatic effect of rapamycin, a well-known mTOR inhibitor with potential clinical applications, was evaluated in monolayer and organotypic cultures. RESULTS: HPV-16 E7 expression in primary human keratinocytes leads to an increase in PLD expression and activity. Moreover, this activation is dependent on the ability of HPV-16 E7 to induce retinoblastoma protein (pRb) degradation. We also show that cells expressing HPV-16 E7 or silenced for pRb acquire resistance to the antiproliferative effect of rapamycin. CONCLUSION: This is the first indication that HPV oncoproteins can affect PLD activity. Since PA can interfere with the ability of rapamycin to bind mTOR, the use of combined strategies to target mTOR and PLD activity might be considered to treat HPV-related malignancies.

Diabetes-specific family conflict: Informant discrepancies and the impact of parental factors.

Family conflict in adolescents with type 1 diabetes (T1D) has been linked to worse disease management (i.e., glycemic control, adherence to treatment regimen) and reduced quality of life. We sought to examine parental risk factors associated with increased levels of diabetes-specific family conflict and to investigate the discrepancies between parent and adolescent reports of conflict. Adolescents with T1D and their parents (N = 120 dyads) completed measures of diabetes-specific family conflict. Adolescents also reported on health-related quality of life, and parents reported on demographic information. Clinical data were obtained from adolescents' medical records. Adolescents reported significantly greater levels of conflict than their parents around direct diabetes management tasks (e.g., checking blood sugars) and indirect management tasks (e.g., carrying supplies for high or low blood sugars). Several demographic factors were associated with family conflict, including parental education, marital status, and household income. Discrepancies between parent and adolescent reports of family conflict were significantly associated with diabetes-related outcomes. Specifically, higher quality of life was related to discrepancies between parent and adolescent reports of conflict around indirect management tasks. In addition, poorer glycemic control was related to discrepancies between parent and adolescent reports of family conflict around direct diabetes management tasks. These results support obtaining both the adolescent and parent report of conflict for unique information regarding family functioning. (PsycINFO Database Record

Obstructive Sleep Apnea and Otolaryngologic Manifestations in Children with Pseudohypoparathyroidism.

BACKGROUND/AIMS: Pseudohypoparathyroidism (PHP) is a rare, genetic disorder. Patients with PHP may have increased prevalence of obstructive sleep apnea (OSA) but this has not been prospectively studied. METHODS: We enrolled children aged 6-18 years with PHP and matched controls. Evaluation included physical examination, medical history, and polysomnography. RESULTS: Fifteen children with PHP type 1A (PHP1A) and 15 controls completed the study. Both groups were obese (BMI 32.2 ± 8.7 vs. 31.7± 6.5). The majority of PHP1A patients required tympanostomy tubes (86.7%) and adenotonsillectomy (73.3%). The primary outcome, i.e., the obstructive disturbance index, was significantly higher in PHP1A children versus controls (1.8 ± 2.3 vs. 0.6 ± 0.5, p = 0.045). Children with PHP1A were more likely to have OSA compared with controls (60.0 vs. 13.3%, p = 0.008). Three siblings with PHP type 1B (PHP1B) were also studied (BMI 25.9 ± 9.0). None had a history of adenotonsillectomy, one had tympanostomy tubes. The obstructive disturbance index (2.0 ± 2.3) was similar to that of children with PHP1A. Two (66.7%) PHP1B participants had OSA. CONCLUSION: Children with PHP1A are at an increased risk for OSA compared with similarly obese peers. They also have higher rates of otitis media and adenotonsillar hypertrophy. Screening for OSA should be considered in all patients with PHP1A and possibly PHP1B though more research is needed.

Sleep in Type 1 Diabetes: Implications for Glycemic Control and Diabetes Management.

PURPOSE OF REVIEW: To highlight recent findings from studies of sleep in type 1 diabetes (T1D), with a focus on the role of sleep in self-management, the cognitive and psychosocial outcomes related to sleep disturbances, and factors associated with sleep disturbances specific to T1D. RECENT FINDINGS: People with T1D experience higher rates of sleep disturbances than people without diabetes, and these disturbances have negative implications for glycemic control and diabetes management, as well as psychosocial and cognitive outcomes. Inconsistent sleep timing (bedtime and wake time) has emerged as a potential target for interventions, as variability in sleep timing has been linked with poorer glycemic control and adherence to treatment. Sleep-promoting interventions and new diabetes technology have the potential to improve sleep in people with T1D. Sleep is increasingly considered a critical factor in diabetes management, but more multi-method and longitudinal research is needed. We emphasize the importance of sufficient and consistent sleep for people with T1D, and the need for providers to routinely assess sleep among patients with T1D.

CCR2 contributes to the recruitment of monocytes and leads to kidney inflammation and fibrosis development.

Chemokines are a large family of proteins that, once associated to its receptor on leukocytes, stimulate their movement and migration from blood to tissues. Once in the tissue, immune cells trigger inflammation that, when uncontrolled, leads to fibrosis development. Among the immune cells, macrophages take a special role in fibrosis formation, since macrophage depletion reflects less collagen deposition. The majority of tissue macrophages is derived from monocytes, especially monocytes expressing the chemokine receptor CCR2. Here, we investigated the role of infiltrating CCR2+ cells in the development of fibrosis, and specifically, the dynamic of infiltration of these cells into kidneys under chronic obstructive lesion. Using liposome-encapsulated clodronate, we observed that macrophage depletion culminated in less collagen deposition and reduced chemokines milieu that were released in the damaged kidney after obstructive nephropathy. We also obstructed the kidneys of CCL3-/-, CCR2-/-, CCR4-/-, CCR5-/-, and C57BL/6 mice and we found that among all animals, CCR2-/- mice demonstrated the more robust protection, reflected by less inflammatory and Th17-related cytokines and less collagen formation. Next we evaluated the dynamic of CCR2+/rfp cell infiltration and we observed that they adhere onto the vessels at early stages of disease, culminating in increased recruitment of CCR2+/rfp cells at later stages. On the other hand, CCR2rfp/rfp animals exhibited less fibrosis formation and reduced numbers of recruited cells at later stages. We have experimentally demonstrated that inflammatory CCR2+ cells that reach the injured kidney at initial stages after tissue damage are responsible for the fibrotic pattern observed at later time points in the context of UUO.

Antimicrobial Peptide K0-W6-Hya1 Induces Stable Structurally Modified Lipid Domains in Anionic Membranes.

Considering the known different mode of action of antimicrobial peptides in zwitterionic and anionic cell membranes, the present work compares the action of the antimicrobial peptide K0-W6-Hya1 (KIFGAIWPLALGALKNLIK-NH2) with zwitterionic and negatively charged model membranes, namely, liposomes composed of phosphatidylcholine (PC) and phosphatidylglycerol (PG) membranes, and a mixture of the two. Differential scanning calorimetry (DSC), steady state fluorescence of the Trp residue, dynamic light scattering (DLS), and measurement of the leakage of an entrapped fluorescent dye (carboxyfluorescein, CF) were performed with large unilamellar vesicles (LUVs). All techniques evidenced the different action of the peptide in zwitterionic and anionic vesicles. Trp fluorescence spectroscopy shows that the differences are related not only to the partition of the cationic peptide in zwitterionic and anionic membranes, but also to the different penetration depth of the peptide into the lipid bilayers: Trp goes deeper into negatively charged membranes, both in the gel and fluid phases, than into zwitterionic ones. DSC shows that the peptide is strongly attached to anionic bilayers, giving rise to the coexistence of two different lipid regions, one depleted of peptide and another one peptide-disturbed, possibly a stable or transient polar pore, considering the leakage of CF. This contrasts with the homogeneous effect produced by the peptide in zwitterionic membranes, probably related to peptide-membrane diffusion. Moreover, in mixed bilayers (PC:PG), the peptide sequesters negatively charged lipids, creating peptide-rich anionic lipid regions, strongly disturbing the membrane. The distinct structural interaction displayed by the peptide in PC and PG membranes could be related to the different mechanisms of action of the peptide in anionic prokaryotic and zwitterionic eukaryotic cell membranes.