Metabolic remodeling in astrocytes: Paving the path to brain tumor development.

The brain is a highly metabolic organ, composed of multiple cell classes, that controls crucial functions of the body. Although neurons have traditionally been the main protagonist, astrocytes have gained significant attention over the last decade. In this regard, astrocytes are a type of glial cells that have recently emerged as critical regulators of central nervous system (CNS) function and play a significant role in maintaining brain energy metabolism. However, in certain scenarios, astrocyte behavior can go awry, which poses a significant threat to brain integrity and function. This is definitively the case for mutations that turn normal astrocytes and astrocytic precursors into gliomas, an aggressive type of brain tumor. In addition, healthy astrocytes can interact with tumor cells, becoming part of the tumor microenvironment and influencing disease progression. In this review, we discuss the recent evidence suggesting that disturbed metabolism in astrocytes can contribute to the development and progression of fatal human diseases such as cancer. Emphasis is placed on detailing the molecular bases and metabolic pathways of this disease and highlighting unique metabolic vulnerabilities that can potentially be exploited to develop successful therapeutic opportunities.

CD40 in Endothelial Cells Restricts Neural Tissue Invasion by Toxoplasma gondii.

Little is known about whether pathogen invasion of neural tissue is affected by immune-based mechanisms in endothelial cells. We examined the effects of endothelial cell CD40 on Toxoplasma gondii invasion of the retina and brain, organs seeded hematogenously. T. gondii circulates in the bloodstream within infected leukocytes (including monocytes and dendritic cells) and as extracellular tachyzoites. After T. gondii infection, mice that expressed CD40 restricted to endothelial cells exhibited diminished parasite loads and histopathology in the retina and brain. These mice also had lower parasite loads in the retina and brain after intravenous (i.v.) injection of infected monocytes or dendritic cells. The protective effect of endothelial cell CD40 was not explained by changes in cellular or humoral immunity, reduced transmigration of leukocytes into neural tissue, or reduced invasion by extracellular parasites. Circulating T. gondii-infected leukocytes (dendritic cells used as a model) led to infection of neural endothelial cells. The number of foci of infection in these cells were reduced if endothelial cells expressed CD40. Infected dendritic cells and macrophages expressed membrane-associated inducible Hsp70. Infected leukocytes triggered Hsp70-dependent autophagy in CD40+ endothelial cells and anti-T. gondii activity dependent on ULK1 and beclin 1. Reduced parasite load in the retina and brain not only required CD40 expression in endothelial cells but was also dependent on beclin 1 and the expression of inducible Hsp70 in dendritic cells. These studies suggest that during endothelial cell-leukocyte interaction, CD40 restricts T. gondii invasion of neural tissue through a mechanism that appears mediated by endothelial cell anti-parasitic activity stimulated by Hsp70.

Immunoassays for scarce tumour-antigens in exosomes: detection of the human NKG2D-Ligand, MICA, in tetraspanin-containing nanovesicles from melanoma.

BACKGROUND: Tumour-derived exosomes can be released to serum and provide information on the features of the malignancy, however, in order to perform systematic studies in biological samples, faster diagnostic techniques are needed, especially for detection of low abundance proteins. Most human cancer cells are positive for at least one ligand for the activating immune receptor NKG2D and the presence in plasma of NKG2D-ligands can be associated with prognosis. METHODS: Using MICA as example of a tumour-derived antigen, endogenously expressed in metastatic melanoma and recruited to exosomes, we have developed two immunocapture-based assays for detection of different epitopes in nanovesicles. Although both techniques, enzyme-linked immunosorbent assay (ELISA) and Lateral flow immunoassays (LFIA) have the same theoretical basis, that is, using capture and detection antibodies for a colorimetric read-out, analysis of exosome-bound proteins poses methodological problems that do not occur when these techniques are used for detection of soluble molecules, due to the presence of multiple epitopes on the vesicle. RESULTS: Here we demonstrate that, in ELISA, the signal obtained was directly proportional to the amount of epitopes per exosome. In LFIA, the amount of detection antibody immobilized in Au-nanoparticles needs to be low for efficient detection, otherwise steric hindrance results in lower signal. We describe the conditions for detection of MICA in exosomes and prove, for the first time using both techniques, the co-existence in one vesicle of exosomal markers (the tetraspanins CD9, CD63 and CD81) and an endogenously expressed tumour-derived antigen. The study also reveals that scarce proteins can be used as targets for detection antibody in LFIA with a better result than very abundant proteins and that the conditions can be optimized for detection of the protein in plasma. CONCLUSIONS: These results open the possibility of analyzing biological samples for the presence of tumour-derived exosomes using high throughput techniques.

Activated T cells exhibit increased uptake of silicon phthalocyanine Pc 4 and increased susceptibility to Pc 4-photodynamic therapy-mediated cell death.

Photodynamic therapy (PDT) is an emerging treatment for malignant and inflammatory dermal disorders. Photoirradiation of the silicon phthalocyanine (Pc) 4 photosensitizer with red light generates singlet oxygen and other reactive oxygen species to induce cell death. We previously reported that Pc 4-PDT elicited cell death in lymphoid-derived (Jurkat) and epithelial-derived (A431) cell lines in vitro, and furthermore that Jurkat cells were more sensitive than A431 cells to treatment. In this study, we examined the effectiveness of Pc 4-PDT on primary human CD3(+) T cells in vitro. Fluorometric analyses of lysed T cells confirmed the dose-dependent uptake of Pc 4 in non-stimulated and stimulated T cells. Flow cytometric analyses measuring annexin V and propidium iodide (PI) demonstrated a dose-dependent increase of T cell apoptosis (6.6-59.9%) at Pc 4 doses ranging from 0-300 nM. Following T cell stimulation through the T cell receptor using a combination of anti-CD3 and anti-CD28 antibodies, activated T cells exhibited increased susceptibility to Pc 4-PDT-induced apoptosis (10.6-81.2%) as determined by Pc 4 fluorescence in each cell, in both non-stimulated and stimulated T cells, Pc 4 uptake increased with Pc 4 dose up to 300 nM as assessed by flow cytometry. The mean fluorescence intensity (MFI) of Pc 4 uptake measured in stimulated T cells was significantly increased over the uptake of resting T cells at each dose of Pc 4 tested (50, 100, 150 and 300 nM, p < 0.001 between 50 and 150 nM, n = 8). Treg uptake was diminished relative to other T cells. Cutaneous T cell lymphoma (CTCL) T cells appeared to take up somewhat more Pc 4 than normal resting T cells at 100 and 150 nm Pc 4. Confocal imaging revealed that Pc 4 localized in cytoplasmic organelles, with approximately half of the Pc 4 co-localized with mitochondria in T cells. Thus, Pc 4-PDT exerts an enhanced apoptotic effect on activated CD3(+) T cells that may be exploited in targeting T cell-mediated skin diseases, such as cutaneous T cell lymphoma (CTCL) or psoriasis.

Technical efficiency of women's health prevention programs in Bucaramanga, Colombia: a four-stage analysis.

BACKGROUND: Primary Health Care (PHC) is an efficient strategy to improve health outcomes in populations. Nevertheless, studies of technical efficiency in health care have focused on hospitals, with very little on primary health care centers. The objective of the present study was to use the Data Envelopment Analysis to estimate the technical efficiency of three women's health promotion and disease prevention programs offered by primary care centers in Bucaramanga, Colombia. METHODS: Efficiency was measured using a four-stage data envelopment analysis with a series of Tobit regressions to account for the effect of quality outcomes and context variables. Input/output information was collected from the institutions' records, chart reviews and personal interviews. Information about contextual variables was obtained from databases from the primary health program in the municipality. A jackknife analysis was used to assess the robustness of the results. RESULTS: The analysis was based on data from 21 public primary health care centers. The average efficiency scores, after adjusting for quality and context, were 92.4 %, 97.5 % and 86.2 % for the antenatal care (ANC), early detection of cervical cancer (EDCC) and family planning (FP) programs, respectively. On each program, 12 of the 21 (57.1 %) health centers were found to be technically efficient; having had the best-practice frontiers. Adjusting for context variables changed the scores and reference rankings of the three programs offered by the health centers. CONCLUSION: The performance of the women's health prevention programs offered by the centers was found to be heterogeneous. Adjusting for context and health care quality variables had a significant effect on the technical efficiency scores and ranking. The results can serve as a guide to strengthen management and organizational and planning processes related to local primary care services operating within a market-based model such as the one in Colombia.

TLR2 engagement on CD4(+) T cells enhances effector functions and protective responses to Mycobacterium tuberculosis.

We have previously demonstrated that mycobacterial lipoproteins engage TLR2 on human CD4(+) T cells and upregulate TCR-triggered IFN-γ secretion and cell proliferation in vitro. Here we examined the role of CD4(+) T-cell-expressed TLR2 in Mycobacterium tuberculosis (MTB) Ag-specific T-cell priming and in protection against MTB infection in vivo. Like their human counterparts, mouse CD4(+) T cells express TLR2 and respond to TLR2 costimulation in vitro. This Th1-like response was observed in the context of both polyclonal and Ag-specific TCR stimulation. To evaluate the role of T-cell TLR2 in priming of CD4(+) T cells in vivo, naive MTB Ag85B-specific TCR transgenic CD4(+) T cells (P25 TCR-Tg) were adoptively transferred into Tlr2(-/-) recipient C57BL/6 mice that were then immunized with Ag85B and with or without TLR2 ligand Pam3 Cys-SKKKK. TLR2 engagement during priming resulted in increased numbers of IFN-γ-secreting P25 TCR-Tg T cells 1 week after immunization. P25 TCR-Tg T cells stimulated in vitro via TCR and TLR2 conferred more protection than T cells stimulated via TCR alone when adoptively transferred before MTB infection. Our findings indicate that TLR2 engagement on CD4(+) T cells increases MTB Ag-specific responses and may contribute to protection against MTB infection.

Replicative fitness and pathogenicity of primate lentiviruses in lymphoid tissue, primary human and chimpanzee cells: relation to possible jumps to humans.

BACKGROUND: Simian immunodeficiency viruses (SIV) have been jumping between non-human primates in West/Central Africa for thousands of years and yet, the HIV-1 epidemic only originated from a primate lentivirus over 100 years ago. METHODS: This study examined the replicative fitness, transmission, restriction, and cytopathogenicity of 22 primate lentiviruses in primary human lymphoid tissue and both primary human and chimpanzee peripheral blood mononuclear cells. FINDINGS: Pairwise competitions revealed that SIV from chimpanzees (cpz) had the highest replicative fitness in human or chimpanzee peripheral blood mononuclear cells, even higher fitness than HIV-1 group M strains responsible for worldwide epidemic. The SIV strains belonging to the "HIV-2 lineage" (including SIVsmm, SIVmac, SIVagm) had the lowest replicative fitness. SIVcpz strains were less inhibited by human restriction factors than the "HIV-2 lineage" strains. SIVcpz efficiently replicated in human tonsillar tissue but did not deplete CD4+ T-cells, consistent with the slow or nonpathogenic disease observed in most chimpanzees. In contrast, HIV-1 isolates and SIV of the HIV-2 lineage were pathogenic to the human tonsillar tissue, almost independent of the level of virus replication. INTERPRETATION: Of all primate lentiviruses, SIV from chimpanzees appears most capable of infecting and replicating in humans, establishing HIV-1. SIV from other Old World monkeys, e.g. the progenitor of HIV-2, replicate slowly in humans due in part to restriction factors. Nonetheless, many of these SIV strains were more pathogenic than SIVcpz. Either SIVcpz evolved into a more pathogenic virus while in humans or a rare SIVcpz, possibly extinct in chimpanzees, was pathogenic immediately following the jump into human. FUNDING: Support for this study to E.J.A. was provided by the NIH/NIAID R01 AI49170 and CIHR project grant 385787. Infrastructure support was provided by the NIH CFAR AI36219 and Canadian CFI/Ontario ORF 36287. Efforts of J.A.B. and N.J.H. was provided by NIH AI099473 and for D.H.C., by VA and NIH AI AI080313.

[Dietary changes in Mexican women migrating to the U.S]. / Cambios alimenticios en mujeres morelenses migrantes a Estados Unidos.

OBJECTIVE: To describe the dietary changes and processes involved in the incorporation of new foods, in Mexican women with a migratory experience to the U.S. MATERIAL AND METHODS: A qualitative study was conducted, based on grounded theory, of women who had had a migratory experience and were residing in rural zones of the state of Morelos, Mexico. The data were obtained from 47 in-depth interviews carried out from February, 2005 to July, 2006. RESULTS: The women's diet is modified by the migratory experience and the amount of consumption increases during their stay in the U.S. They continue cooking traditional Mexican meals but incorporate foods from their country of destination. These changes are favored by the greater purchasing power, work-related aspects and availability of products and spaces where food is sold. CONCLUSIONS: We need to go deeper into the relationship between food and migration in the context of Mexico - U.S. - Mexico migration and its impact on women's health. We also need to propose public policies geared towards strengthening healthy habits.

Purple urine in Berdon syndrome: a rare finding in the clinic laboratory.

INTRODUCTION: Purple Urine Bag Syndrome (PUBS) is a rare disorder seen in elderly persons, wherein the urinary bag and the tubing turn in to purple colour. It is usually seen in patients who are on urinary catheters for a long time. It consists of a change in the colour of the urine that turns purple in a very specific context. CASE REPORT: We report the case of a paediatric female patient with Berdon Syndrome with symptoms consistent with urinary tract infection and purple urine discolouration. Urine test revealed leukocyturia and bacteriuria. DISCUSSION: Several risk factors have been proposed regarding this syndrome. Among them the commonest are female gender, advanced age, kind of diet (increased dietary tryptophan), alkaline urine and diverse situations that leads to urinary retentions which allows bacteria to work on their substrate for a longer time. Although it is a process that is not associated with gravity, recognizing it is important as treatment is simple and can minimize patient and family distress.

Barriers and facilitators of academia-government collaboration in the context of the COVID-19 pandemic in Colombia: a qualitative study.

The COVID-19 pandemic highlighted the importance of strengthening collaborations between academia and government. The development and maintenance of these collaborative relationships is a complex and dynamic process, particularly during public health emergencies. This study was aimed at identifying and analysing factors that acted as barriers and facilitators in the collaboration process between academia and government during the COVID-19 pandemic in the five largest cities in Colombia. The study used a qualitative approach based on the systematization of experiences. A total of 25 semi-structured interviews were conducted with local actors from government and academia during 2021. Participants identified a variety of situations that involved individual, institutional and relational factors that acted as barriers and facilitators, and which have been previously reported in other countries and contexts not related to pandemics. Based on participant reports, two additional factors emerged, one corresponding to situations related to the pandemic management process itself and another related to structural or systemic conditions that involved government processes and the Colombian health system. Despite the challenges posed by the pandemic, the health emergency brought about shared feelings of local commitment and a willingness to work through interdisciplinary teams to address the pandemic with the least adverse effects on the community. Other facilitators of the collaborative process that were recognized were the importance of timely access to data and transparent analyses, as well as government decisions being informed by the perspectives of academics. The main barriers identified by both actors were excessive centralization of the pandemic's management and the need for rapid decision-making processes under high levels of uncertainty. In addition, the fragmentation of services in the health system posed a barrier to the interventions that were suggested by the collaborative work. Our results suggest that government-academia collaborations should be implemented as ongoing participatory processes integrating various sectors, actors and disciplines.

Evaluation of online learning readiness in the new distance learning normality.

The COVID-19 pandemic influenced teaching and learning in higher education. The transformation towards digital education challenged Faculty and students. This research examines the online learning readiness of students in a Higher Education Institution in Mexico. Specifically, we investigated how much prior digital skills, as well as having used the digital resources available by the university, influenced their academic achievement in distance learning settings. Seven dimensions of online learning readiness were selected to evaluate the student's preparation for the online learning process. Questionnaires were applied before the start and at the end of digital courses. Follow-up tools were offered to support the student, and two groups were observed, users and non-users of the digital devices. It was observed that students who used the support developed significantly better critical thinking, problem-solving, and time organization skills than non-users. On the other hand, although the evaluations were not significantly different, the lowest averages were found in the non-user group. Our results indicate that prior training in the use of digital tools is essential for the success of online education; in the same way, a timely follow-up with technical and pedagogical assistance is necessary for developing competencies. Training more autonomous and independent students capable of distance learning in a global world demands experts in digital education urgently. Educational institutions must embrace new technologies and teaching methods to meet the ever-changing needs of students. This research is expected to play a crucial role in promoting constructive discussions and facilitating informed decisions concerning the creation of future educational models.

Prevalence of the practice of physical activity and its associated factors in adult Colombian pregnant women / Prevalencia y factores asociados con la práctica de actividad física en mujeres gestantes adultas en Colombia

Introduction: Physical activity during pregnancy can be useful in the prevention of gestational complications. Objective: To estimate the prevalence of physical activity in adult Colombian pregnant women and its associated factors. Materials and methods: A secondary analysis of data from the 2015 National Nutrition Survey in Colombia was conducted. The total sample included 906 pregnant women. Leisure-time, commuting, and global physical activity were measured with the long version of the International Physical Activity Questionnaire. Factors associated with PA were evaluated through negative binomial regression models. Results: The prevalence of physical activity in pregnant women was 12.57% (95% CI=8.41-18.38), 28.66% (95% CI=23.29-34.70), and 36.33% (95% CI=30.92-42.11) in the leisuretime, commuting and global domains, respectively. Factors associated with leisure-time physical activity were living in Bogotá (prevalence ratio, PR=2.41; 95% CI=1.16-4.99), being in the third gestational trimester (PR=2.13; 95% CI=1.17-3.87), obtaining access to physical activity programs (PR=1.75; 95% CI=1.07-2.87), having a high school education (PR=0.51; 95% CI=0.29-0.91), and being in the second (PR=0.45; 95% CI=0.24-0.81), third and fourth quartiles of wealth (PR=0.43; 95% CI=0.23-0.80). Factors associated with physical activity while commuting were having at least one child (PR=1.60; 95% CI=1.14-2.24), living in Bogotá (PR=1.84; 95% CI=1.23-2.73), living with a partner (PR=0.66; 95% CI=0.49-0.89), and completing between one and four prenatal care sessions (PR=0.53; 95% CI=0.37-0.76). Conclusions: The prevalence of physical activity in pregnant Colombian women is worryingly low. Programs and projects aimed at promoting physical activity during pregnancy are needed.

Introducción. La actividad física durante el embarazo puede ser útil para la prevención de complicaciones gestacionales. Objetivo. Estimar la prevalencia de actividad física en mujeres gestantes adultas en Colombia y evaluar los factores asociados con su práctica. Materiales y métodos. Se hizo un análisis secundario de la información recolectada en la Encuesta Nacional de Situación Nutricional en Colombia del 2015. La muestra incluyó 906 mujeres gestantes. La actividad física en los dominios de tiempo libre, transporte y global se evaluó con la versión larga del International Physical Activity Questionnaire. Los factores asociados se evaluaron mediante modelos de regresión binomial negativa. Resultados. La prevalencia del cumplimiento de las recomendaciones de actividad física en las participantes fue de 12,57 % (IC95% 8,41-18,38), 28,66 % (IC95% 23,29-34,70) y 36,33 % (IC95% 30,92-42,11) en los dominios de tiempo libre, transporte y global, respectivamente. Los factores asociados con el dominio de tiempo libre fueron: residir en Bogotá (razón de prevalencia, RP=2,41; IC95% 1,16-4,99), encontrarse en el tercer trimestre de la gestación (RP=2,13; IC95% 1,17-3,87), disponer de programas de actividad física dirigida (RP=1,75; IC95% 1,07-2,87), nivel educativo de secundaria (RP=0,51; IC95% 0,29-0,91), y pertenecer a los cuartiles de riqueza dos (RP=0,45; IC95% 0,24-0,81), tres y cuatro (RP=0,43; IC95% 0,23-0,80). Los factores asociados con el transporte fueron: tener, por lo menos, un hijo (RP=1,60; IC95% 1,14-2,24), residir en Bogotá (RP=1,84; IC95% 1,23-2,73), convivir con compañero sentimental (RP=0,66: IC95% 0,49-0,89) y haber asistido a entre uno y cuatro controles prenatales (RP=0,53; IC95% 0,37-0,76). Conclusiones: La prevalencia de la actividad física en mujeres gestantes colombianas es preocupantemente baja. Se requiere la implementación de programas y proyectos orientados a la promoción de la actividad física durante el embarazo.

Concerted Model of Healthcare for Awá Indigenous of Nariño, Colombia.

Indigenous communities in Colombia are facing a critical health situation; alternative health care models based on the vision of the communities themselves are needed. The objective of this research was to create a health care model that decreases health inequities for the Indigenous Awá population of Nariño, Colombia. This study was guided by the paradigm of community-based participatory action research; the process was carried out in 2015 and 2016. The proposed Intercultural Health Care Model is essentially based on health promotion, disease prevention, community empowerment, social participation in health, decentralized health care and coordination between the two medicines (traditional and allopathic). Strategies such as those reported herein, with concerted efforts rather than imposition, maintain human rights and respect for the sovereignty and autonomy of Indigenous people.

[Benefits of combining methods to analyze the causes of maternal mortality, Bucaramanga, Colombia]. / Beneficios de combinar métodos para analizar causas de muertes maternas, Bucaramanga, Colombia.

OBJECTIVE: Define critical points of change in the maternal care process, guide decision-making in this area, and support the strengthening of service delivery policies, with a view to achieving the Millennium Development Goal of improving maternal health. METHODS: Retrospective descriptive study of a series of cases of maternal deaths recorded in Bucaramanga between 2004 and 2009. The study examined epidemiologic reporting cards, clinical histories, field visits, and the records of analysis committees. The road to survival (analysis of delays) and detection of critical links in care were used as the methods of analysis. The information obtained was triangulated. RESULTS: The 10 maternal deaths occurred in an urban area, and the women had received medical care from professionals at a health facility. The four types of delays-in recognizing the problem, in the timeliness of decisions and actions, in care/the logistics of referral, and in the quality of care-occurred with similar frequency in the 10 cases studied. The critical links in the prevention of maternal deaths were those related to deficiencies in the vertical and horizontal integration of the care process and the quality of care. CONCLUSIONS: Combining analysis methods made it possible to identify the deficiencies in care most related to maternal deaths. However, their use should be accompanied by other methods that make it possible to identify determinants that go beyond the context of service delivery. One documented lesson learned is the importance of the continuity and monitoring of interventions as a success factor in reducing maternal mortality.

[Perception of epidemiological competencies by public health students in Mexico and Colombia during the influenza A (H1N1) epidemic]. / Percepción de competencias en epidemiología en México y Colombia durante la epidemia de influenza A (H1N1) entre estudiantes de salud pública.

OBJECTIVE: Learn about the perception of public health students in Mexico and Colombia regarding the management of the influenza A (H1N1) epidemic to determine which curriculum contents in epidemiological education can be improved. METHODS: Survey administered to graduate students during the epidemic, from June to August 2009. The 30 epidemiological competencies for "intermediate epidemiologists" of the Council of State and Territorial Epidemiologists were evaluated. The results were described through stratification by covariables, and the less developed competencies were identified through exploratory factor analysis. RESULTS: A total of 154 students participated, 55.8% of whom were in Mexico. Significant differences in the student profile from each country were observed, which partially explains the perception of response to the epidemic. The first factor, which explains 21.5% of the variance, had lower scores in the factor analysis. This factor was associated with competencies related to the links between health personnel and the community, in which knowledge of the social sciences and communication skills are relevant. CONCLUSIONS: The students perceived that the response to the epidemic could have been better. It is suggested that public health human resources education include subjects related to the impact of culture on behavior and thinking, recognition of the prejudices of experts, effective community-level communication, and the ability to adapt to new situations. The "natural experiment" of the epidemic facilitated the identification of areas of opportunity to improve the teaching of epidemiology to health personnel.

Extracellular Vesicles: Current Analytical Techniques for Detection and Quantification.

Since their first observation, understanding the biology of extracellular vesicles (EV) has been an important and challenging field of study. They play a key role in the intercellular communication and are involved in important physiological and pathological functions. Therefore, EV are considered as potential biomarkers for diagnosis, prognosis, and monitoring the response to treatment in some diseases. In addition, due to their properties, EV may be used for therapeutic purposes. In the study of EV, three major points have to be addressed: 1. How to isolate EV from cell culture supernatant/biological fluids, 2. how to detect them, and 3. how to characterize and quantify. In this review, we focus on the last two questions and provide the main analytical techniques up-to-date for detection and profiling of EV. We critically analyze the advantages and disadvantages of each one, aimed to be of relevance for all researchers working on EV biology and their potential applications.

Preparation and evaluation of a BisGMA-free dental composite resin based on a novel trimethacrylate monomer.

OBJECTIVE: The use of the BisGMA as base monomer in dental composites has been questioned because of bisphenol A (BPA) is used as raw material in its synthesis, and BPA possess estrogenic potential associated to several health problems. This study describes the synthesis of the trimethacrylate tris(4-hydroxyphenyl)methane triglycidyl methacrylate (TTM) monomer and evaluate its effect when used as base monomer in the formulation of experimental photopolymerizable composite resins. METHODS: The TTM monomer was synthesized by a nucleophilic acyl substitution. Its chemical structure was confirmed via 1H and 13C NMR spectroscopy and FTIR spectroscopy. Experimental composite resins were formulated by mixing TTM, triethyleneglycol dimethacrylate (TEGDMA) and inorganic fillers. A BisGMA/TEGDMA based composite resin was prepared and used as control to compare several physicochemical properties. Cell viability assay was used for cytotoxicity evaluation. RESULTS: TTM was successfully synthesized with quantitative yields. The results showed that the TTM-based composite resin had similar values of flexural strength, elastic modulus, degree of conversion and polymerization shrinkage than the control (p > 0.05). Water sorption and solubility were statistically significantly higher than the control (p < 0.05), however they complied the requirements stablished by the ISO 4049. Finally, this study shows there were no statistically significant differences for the biocompatibility outcomes (p = 0.345). SIGNIFICANCE: TTM monomer could be potentially useful in the formulation of BisGMA free composite resins, which could mean to minimize the human exposure to BPA.

Connexin43 peptide, TAT-Cx43266-283, selectively targets glioma cells, impairs malignant growth, and enhances survival in mouse models in vivo.

BACKGROUND: Malignant gliomas are the most frequent primary brain tumors and remain among the most incurable cancers. Although the role of the gap junction protein, connexin43 (Cx43), has been deeply investigated in malignant gliomas, no compounds have been reported with the ability to recapitulate the tumor suppressor properties of this protein in in vivo glioma models. METHODS: TAT-Cx43266-283 a cell-penetrating peptide which mimics the effect of Cx43 on c-Src inhibition, was studied in orthotopic immunocompetent and immunosuppressed models of glioma. The effects of this peptide in brain cells were also analyzed. RESULTS: While glioma stem cell malignant features were strongly affected by TAT-Cx43266-283, these properties were not significantly modified in neurons and astrocytes. Intraperitoneally administered TAT-Cx43266-283 decreased the invasion of intracranial tumors generated by GL261 mouse glioma cells in immunocompetent mice. When human glioma stem cells were intracranially injected with TAT-Cx43266-283 into immunodeficient mice, there was reduced expression of the stemness markers nestin and Sox2 in human glioma cells at 7 days post-implantation. Consistent with the role of Sox2 as a transcription factor required for tumorigenicity, TAT-Cx43266-283 reduced the number and stemness of human glioma cells at 30 days post-implantation. Furthermore, TAT-Cx43266-283 enhanced the survival of immunocompetent mice bearing gliomas derived from murine glioma stem cells. CONCLUSION: TAT-Cx43266-283 reduces the growth, invasion, and progression of malignant gliomas and enhances the survival of glioma-bearing mice without exerting toxicity in endogenous brain cells, which suggests that this peptide could be considered as a new clinical therapy for high-grade gliomas.

Targeting metabolic plasticity in glioma stem cells in vitro and in vivo through specific inhibition of c-Src by TAT-Cx43266-283.

BACKGROUND: Glioblastoma is the most aggressive primary brain tumour and has a very poor prognosis. Inhibition of c-Src activity in glioblastoma stem cells (GSCs, responsible for glioblastoma lethality) and primary glioblastoma cells by the peptide TAT-Cx43266-283 reduces tumorigenicity, and boosts survival in preclinical models. Because c-Src can modulate cell metabolism and several reports revealed poor clinical efficacy of various antitumoral drugs due to metabolic rewiring in cancer cells, here we explored the inhibition of advantageous GSC metabolic plasticity by the c-Src inhibitor TAT-Cx43266-283. METHODS: Metabolic impairment induced by the c-Src inhibitor TAT-Cx43266-283 in vitro was assessed by fluorometry, western blotting, immunofluorescence, qPCR, enzyme activity assays, electron microscopy, Seahorse analysis, time-lapse imaging, siRNA, and MTT assays. Protein expression in tumours from a xenograft orthotopic glioblastoma mouse model was evaluated by immunofluorescence. FINDINGS: TAT-Cx43266-283 decreased glucose uptake in human GSCs and reduced oxidative phosphorylation without a compensatory increase in glycolysis, with no effect on brain cell metabolism, including rat neurons, human and rat astrocytes, and human neural stem cells. TAT-Cx43266-283 impaired metabolic plasticity, reducing GSC growth and survival under different nutrient environments. Finally, GSCs intracranially implanted with TAT-Cx43266-283 showed decreased levels of important metabolic targets for cancer therapy, such as hexokinase-2 and GLUT-3. INTERPRETATION: The reduced ability of TAT-Cx43266-283-treated GSCs to survive in metabolically challenging settings, such as those with restricted nutrient availability or the ever-changing in vivo environment, allows us to conclude that the advantageous metabolic plasticity of GSCs can be therapeutically exploited through the specific and cell-selective inhibition of c-Src by TAT-Cx43266-283. FUNDING: Spanish Ministerio de Economía y Competitividad (FEDER BFU2015-70040-R and FEDER RTI2018-099873-B-I00), Fundación Ramón Areces. Fellowships from the Junta de Castilla y León, European Social Fund, Ministerio de Ciencia and Asociación Española Contra el Cáncer (AECC).

Structural factors and mechanisms underlying the improved photodynamic cell killing with silicon phthalocyanine photosensitizers directed to lysosomes versus mitochondria.

The phthalocyanine photosensitizer Pc 4 has been shown to bind preferentially to mitochondrial and endoplasmic reticulum membranes. Upon photoirradiation of Pc 4-loaded cells, membrane components, especially Bcl-2, are photodamaged and apoptosis, as indicated by activation of caspase-3 and cleavage of poly(ADP-ribose) polymerase, is triggered. A series of analogs of Pc 4 were synthesized, and the results demonstrate that Pcs with the aminopropylsiloxy ligand of Pc 4 or a similar one on one side of the Pc ring and a second large axial ligand on the other side of the ring have unexpected properties, including enhanced cell uptake, greater monomerization resulting in greater intracellular fluorescence and three-fold higher affinity constants for liposomes. The hydroxyl-bearing axial ligands tend to reduce aggregation of the Pc and direct it to lysosomes, resulting in four to six times more killing of cells, as defined by loss of clonogenicity, than with Pc 4. Whereas Pc 4-PDT photodamages Bcl-2 and Bcl-xL, Pc 181-PDT causes much less photodamage to Bcl-2 over the same dose-response range relative to cell killing, with earlier cleavage of Bid and slower caspase-3-dependent apoptosis. Therefore, within this series of photosensitizers, these hydroxyl-bearing axial ligands are less aggregated than is Pc 4, tend to localize to lysosomes and are more effective in overall cell killing than is Pc 4, but induce apoptosis more slowly and by a modified pathway.