Toxicological effects of solvent-extracted organic matter associated with PM2.5 on human bronchial epithelial cell line NL-20.

The heterogeneity and complexity of solvent-extracted organic matter associated with PM2.5 (SEOM-PM2.5) is well known; however, there is scarce information on its biological effects in human cells. This work aimed to evaluate the effect of SEOM-PM2.5 collected in northern Mexico City during the cold-dry season (November 2017) on NL-20 cells, a human bronchial epithelial cell line. The SEOM obtained accounted for 15.5% of the PM2.5 mass and contained 21 polycyclic aromatic hydrocarbons (PAHs). The cell viability decreased following exposure to SEOM-PM2.5, and there were noticeable morphological changes such as increased cell size and the presence of cytoplasmic vesicles in cells treated with 5-40 µg/mL SEOM-PM2.5. Exposure to 5 µg/mL SEOM-PM2.5 led to several alterations compared with the control cells, including the induction of double-stranded DNA breaks based (p < 0.001); nuclear fragmentation and an increased mitotic index (p < 0.05); 53BP1 staining, a marker of DNA repair by non-homologous end-joining (p < 0.001); increased BiP protein expression; and reduced ATF6, IRE1α, and PERK gene expression. Conversely, when exposed to 40 µg/mL SEOM-PM2.5, the cells showed an increase in reactive oxygen species formation (p < 0.001), BiP protein expression (p < 0.05), and PERK gene expression (p < 0.05), indicating endoplasmic reticulum stress. Our data suggest concentration-dependent toxicological effects of SEOM-PM2.5 on NL-20 cells, including genotoxicity, genomic instability, and endoplasmic reticulum stress.

Endoplasmic Reticulum Stress in Gliomas: Exploiting a Dual-Effect Dysfunction through Chemical Pharmaceutical Compounds and Natural Derivatives for Therapeutical Uses.

The endoplasmic reticulum maintains proteostasis, which can be disrupted by oxidative stress, nutrient deprivation, hypoxia, lack of ATP, and toxicity caused by xenobiotic compounds, all of which can result in the accumulation of misfolded proteins. These stressors activate the unfolded protein response (UPR), which aims to restore proteostasis and avoid cell death. However, endoplasmic response-associated degradation (ERAD) is sometimes triggered to degrade the misfolded and unassembled proteins instead. If stress persists, cells activate three sensors: PERK, IRE-1, and ATF6. Glioma cells can use these sensors to remain unresponsive to chemotherapeutic treatments. In such cases, the activation of ATF4 via PERK and some proteins via IRE-1 can promote several types of cell death. The search for new antitumor compounds that can successfully and directly induce an endoplasmic reticulum stress response ranges from ligands to oxygen-dependent metabolic pathways in the cell capable of activating cell death pathways. Herein, we discuss the importance of the ER stress mechanism in glioma and likely therapeutic targets within the UPR pathway, as well as chemicals, pharmaceutical compounds, and natural derivatives of potential use against gliomas.

ETV5 Silencing Produces Mesenchymal to Epithelial Transition in INS-1 (832/13) Cell Line.

ETV5 has been described to be involved in the epithelial to mesenchymal transition (EMT) mainly in cancer. It is known that EMT provokes cytoskeleton remodeling, improving cellular migratory, and invasive capabilities. Moreover, overexpression of ETV5 has been correlated to cancer development and this gene has been implicated in cell proliferation. However, little is known about the downregulation of ETV5 expression in a pancreatic cell line and the inverse mesenchymal to epithelial transition (MET). Therefore, we studied the implications of ETV5 silencing over the phenotype of the insulinoma INS-1 (832/13) cell line and described the MET by partial ETV5 silencing in the INS-1 (832/13) cell line. The downregulation of ETV5 expression was obtained by using ETV5 siRNA in the insulinoma rat cell line, INS-1 (832/13). Then, ETV5 knockdown provoked a MET phenotype observed by crystal violet staining and verified by immunohistochemistry against E-cadherin. Wound healing assay showed no migration, and F-actin stain revealed rearrangement of actin microfilaments. In addition, TGFß1 and TGFß3 were downregulated in the absence of ETV5. ETV5 silencing induces epithelial phenotype by downregulating TGFß1 and TGFß3 in INS-1 (832/13) cell line.

Nano fraction of pesticide induces genotoxicity and oxidative stress-dependent reticulum stress.

The implementation of nanotechnology in different sectors has generated expectations as a new source of use due to the novel characteristics that it will bring. Particularly, nano pesticides promise to be more sustainable and less harmful to the ecosystem and human health; however, most studies continue to focus on their efficacy in the field, leaving aside the effect on humans. This project aimed to evaluate the genotoxic effect of a nano-encapsulated pesticide on bronchial epithelial cells (NL-20) in vitro and elucidate the mechanism through which they induce damage. The nano fraction (NF) of the pesticide Karate Zeon® 5 CS was characterized and isolated, and the uptake into the cell and the changes induced in the cellular ultrastructure were evaluated. In addition, the primary markers of oxidative stress, reticulum stress, and genotoxicity were assessed using the micronucleus test. A 700 nm fraction with a Z potential of -40 mV was obtained, whose main component is polyurea formaldehyde; this allows the capsules to enter the cell through macropinocytosis and clathrin-mediated endocytosis. Inside, they induce oxidative stress activating a reticulum stress response via the BIP protein and the IRE-1 sensor, triggering an inflammatory response. Likewise, stress reduces cell proliferation, increasing genotoxic damage through micronuclei; however, this damage is mainly induced by direct contact of the capsules with the nucleus. This pioneering study uses a nanometric encapsulated commercial pesticide to evaluate the molecular mechanism of induced damage. It makes it the first step in analyzing whether these substances represent a contaminant or an emerging solution.

Effects of green tea polyphenols against metal-induced genotoxic damage: underlying mechanistic pathways.

This review is based upon evidence from the published effects of green tea polyphenols (GTP) on genotoxic damage induced by metals with carcinogenic potential. First, the relationship between GTP and antioxidant defense system is provided. Subsequently, the processes involved in the oxidative stress generated by metals and their relationship to oxidative DNA damage is examined. The review demonstrated that GTP generally decrease oxidative DNA damage induced by exposure to metals such as arsenic (As), cadmium (Cd), cobalt (Co), copper (Cu), chromium (Cr), iron (Fe), and lead (Pb). The pathways involved in these effects are related to: (1) direct scavenging of free radicals (FR); (2) activation of mechanisms to repair oxidative DNA damage; (3) regulation of the endogenous antioxidant system; and (4) elimination of cells with genetic damage via apoptosis. The results obtained in the studies reviewed demonstrate potential for possible use of GTP to prevent and treat oxidative damage in populations exposed to metals. Further, GTP may be considered as adjuvants to treatments for metal-associated diseases related to oxidative stress and DNA damage.

Perezone and its phenyl glycine derivative induce cytotoxicity via caspases on human glial cancer cells.

The new phenyl glycine derivative of perezone was obtained in a single reaction step in ca. 80% yield which showed remarkable cytotoxic activity against the astrocytoma U-251 cell line. After 24 h of exposure, both perezone (IC50 = 6.83 ± 1.64 µM) and its phenyl glycine derivative (2.60 ± 1.69 µM) showed cytotoxic effect on U-251 cells but were five times less cytotoxic on the non-tumoral SVGp12 cell line (IC50 = 28.54 ± 1.59 and 31.87 ± 1.54 µM respectively). Both compounds induced cellular morphological changes (pyknosis or cytoplasmic vacuolization) and increased the expression of caspases 3, 8, and 9 genes related to apoptosis. In the acute toxicity study, phenyl glycine perezone (DL50 = 2000 mg/Kg) demonstrated to be less toxic than perezone (DL50 = 500 mg/Kg). Phenylglycine-perezone can envisage a beneficial therapeutic potential.

Leukocyte surface expression of the endoplasmic reticulum chaperone GRP78 is increased in severe COVID-19.

Hyperinflammation present in individuals with severe COVID-19 has been associated with an exacerbated cytokine production and hyperactivated immune cells. Endoplasmic reticulum stress leading to the unfolded protein response has been recently reported as an active player in inducing inflammatory responses. Once unfolded protein response is activated, GRP78, an endoplasmic reticulum-resident chaperone, is translocated to the cell surface (sGRP78), where it is considered a cell stress marker; however, its presence has not been evaluated in immune cells during disease. Here we assessed the presence of sGRP78 on different cell subsets in blood samples from severe or convalescent COVID-19 patients. The frequency of CD45+sGRP78+ cells was higher in patients with the disease compared to convalescent patients. The latter showed similar frequencies to healthy controls. In patients with COVID-19, the lymphoid compartment showed the highest presence of sGRP78+ cells versus the myeloid compartment. CCL2, TNF-α, C-reactive protein, and international normalized ratio measurements showed a positive correlation with the frequency of CD45+sGRP78+ cells. Finally, gene expression microarray data showed that activated T and B cells increased the expression of GRP78, and peripheral blood mononuclear cells from healthy donors acquired sGRP78 upon activation with ionomycin and PMA. Thus, our data highlight the association of sGRP78 on immune cells in patients with severe COVID-19.

The wild plant Gnaphalium lavandulifolium as a sentinel for biomonitoring the effects of environmental heavy metals in the metropolitan area of México Valley.

Biomonitoring is a valuable tool for assessing the presence and effects of air pollutants such as heavy metals (HM); due to their toxicity and stability, these compounds can affect human health and the balance of ecosystems. To assess its potential as a sentinel organism of HM pollution, the wild plant Gnaphalium lavandulifolium was exposed to four sites in the metropolitan area of México Valley (MAMV): Altzomoni (ALT) Coyoacán (COY), Ecatepec (ECA), and Tlalnepantla (TLA) during 2, 4, and 8 weeks, between October and November 2019. Control plants remained under controlled conditions. The chemical analysis determined twelve HM (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn) in the leaves. Macroscopic damage to the leaves, later determined in semi-thin sections under light microscopy, lead to a finer analysis. Transmission electron microscope (TEM) showed major structural changes: chromatin condensation, protoplast shrinkage, cytoplasm vacuolization, cell wall thinning, decreased number and size of starch grains, and plastoglobules in chloroplasts. All these characteristics of stress-induced programed cell death (sPCD) were related to the significant increase of toxic HM in the leaves of the exposed plants compared to the control (p < 0.05). Immunohistochemistry revealed a significant amount of proteases with caspase 3-like activity in ECA and TLA samples during long exposure times. Ultrastructural changes and sPCD features detected confirmed the usefulness of G. lavandulifolium as a good biomonitor of HM contamination. They supported the possibility of considering subcellular changes as markers of abiotic stress conditions in plants.

The Transcriptomic Landscape of Pediatric Astrocytoma.

Central nervous system tumors are the most common solid neoplasia during childhood and represent one of the leading causes of cancer-related mortality. Tumors arising from astrocytic cells (astrocytomas) are the most frequently diagnosed, and according to their histological and pathological characteristics, they are classified into four categories. However, an additional layer of molecular classification considering the DNA sequence of the tumorigenesis-associated genes IDH1/2 and H3F3A has recently been incorporated into the classification guidelines. Although mutations in H3F3A are found exclusively in a subtype of grade IV pediatric astrocytoma, mutations in IDH1/2 genes are very rare in children under 14 years of age. The transcriptomic profiles of astrocytoma in adults and children have been extensively studied. However, there is scarce information on these profiles in pediatric populations considering the status of tumorigenesis-associated genes. Therefore, here we report the transcriptomic landscape of the four grades of pediatric astrocytoma by RNA sequencing. We found several well-documented biological functions associated with the misregulated genes in the four grades of astrocytoma, as well as additional biological pathways. Among the four grades of astrocytoma, we found shared misregulated genes that could have implications in tumorigenesis. Finally, we identified a transcriptional signature for almost all grades of astrocytoma that could be used as a transcription-based identification method.

Catequinas del té verde: efectos antigenotóxicos y genotóxicos. Revisión sistemática / Green tea catechins: antigenotoxic and genotoxic effects. Systematic review

Las catequinas del té verde (Camellia sinensis) (CTV) presentan efectos benéficos para la salud asociados a su potencial antioxidante. Por otra parte, el estrés oxidante es una de las vías de inducción de daño genotóxico. De ahí que, en la presente revisión se realizó un análisis de los efectos antigenotóxicos y genotóxicos de las CTV, haciendo énfasis en las vías implicadas en estos procesos y sus efectos en la salud. Se realizó una revisión de artículos indexados en las bases de datos de PubMed® y Science Direct® (2021) con las palabras clave "green tea" y "green tea catechins". Se delimitaron los estudios utilizando los operadores booleanos "AND", "OR" y "NOT" ("antigenotoxic", "genotoxic", "antioxidant" y "prooxidant"). En su mayoría se consideraron las publicaciones del 2016 al 2021. Se observó que los efectos benéficos en la salud de las CTV están relacionados con: a) su actividad antioxidante mediante la captura, inhibición y prevención de la formación de las especies reactivas de oxígeno; b) la regulación del sistema antioxidante endógeno; c) la activación de los mecanismos de reparación al contribuir en la eliminación del aducto 8-hidroxi-2'-desoxiguanosina; d) la inducción de apoptosis en células con daño al ADN; y e) la inhibición de la inflamación relacionada con su actividad antiapoptótica. Si bien, en algunos de los estudios se reportaron efectos genotóxicos, estos a su vez contribuyeron en la eliminación de células con daño genético, por lo que, no se puede considerar del todo a la actividad genotóxica de las CTV como perjudiciales para la salud(AU)

The green tea catechins (Camellia sinensis) (CTV) have beneficial effects for health associated with their antioxidant potential. Moreover, oxidative stress is one of the pathways for inducing genotoxic damage. Hence, in this review, an analysis of the antigenotoxic and genotoxic effects of CTV was carried out, emphasizing the pathways involved in these processes and their effects on health. A review of articles indexed in the PubMed® and ScienceDirect® (2021) databases with the keywords "green tea" and "green tea catechins" was carried out. Studies were delimited using the Boolean operators "AND", "OR" and "NOT" ("antigenotoxic", "genotoxic", "antioxidant" and "prooxidant"). For the most part, publications from 2016 to 2021 were considered. It was observed that the beneficial health effects of CTVs are related to: a) their antioxidant activity through the capture, inhibition and prevention of the formation of reactive oxygen species; b) the regulation of the endogenous antioxidant system; c) the activation of the repair mechanisms by contributing to the elimination of the 8-hydroxy-2'-deoxyguanosine adduct; d) the induction of apoptosis in cells with DNA damage; and e) the inhibition of inflammation related to its antiapoptotic activity. Although some of the studies reported genotoxic effects, these in turn contributed to the elimination of cells with genetic damage. Therefore, the genotoxic activity of CTV cannot be considered as harmful to health

Comparison of the genotoxicity of two commercial pesticides by their micro and nano size capsules.

The use of nanotechnology in the agrochemical industry has become increasingly popular over the past decade, raising the question of whether these products may represent a risk or benefit compared to their conventional presentations. In this study, we aimed to evaluate the different genotoxic effects of the Complete encapsulated presentation (CEP), the micro encapsulated fraction (MEF), and the nano encapsulated fraction (NEF) of two pesticides (Karate® and Ampligo®) in lymphocytes from human peripheral blood. To test the different fractions, the pesticides were separated by centrifugations by the average size of the capsule, then were characterized by the general composition of the capsule by RAMAN and FTIR spectroscopy and the active ingredient of both pesticides by gas chromatography-mass spectrometry. Each fraction was tested separately and analyzed by comet assay through the tail moment and the percentage of DNA in the tail and the cytokinesis-block micronucleus through their frequency of micronucleus, nucleoplasmic bridges, and nuclear buds. The nuclear division index and the Nuclear Division Cytotoxicity Index were also measured. For both pesticides, the CEP increased the genetic damage observed in the tail moment and percentage of DNA in the tail at all concentrations for both pesticides. However, in the micronucleus test, NEF induced more micronuclei than MEF and CEP in all treatments reducing cell proliferation as the concentration decreased for both pesticides. These results suggested that NEF had more genotoxic effects in both pesticides, increasing the damage to the cells.

Benzo[ghi]perylene induces cellular dormancy signaling and endoplasmic reticulum stress in NL-20 human bronchial epithelial cells.

Benzo[ghi]perylene (BghiP) is produced by the incomplete combustion of gasoline and it is a marker of high vehicular flow in big cities. Nowadays, it is known that BghiP functions as ligand for the aryl hydrocarbon receptor (AhR), which can cause several molecular responses. For this reason, the aim of the present study was to assess the in vitro effects of the exposure to BghiP, specifically, the induction of cellular dormancy and endoplasmic reticulum stress (ER stress) in NL-20 human cells. Our results proved that a 24 h exposure of BghiP, increased the expression of NR2F1 (p < 0.05). NR2F1 is the main activator of cell dormancy, therefore, we analyzed the expression of its target genes SOX9 and p27 showing an increase of the transcripts (p < 0.05), suggesting a pathway that could produce a cell cycle arrest. Interestingly, this effect was only observed with BghiP exposure, and not with a classic AhR ligand: benzo[a]pyrene. Moreover, in the presence of the AhR antagonist, CH223191, or when the expression of AhR was knock-down using dsiRNAs, the cellular dormancy signaling pathway was blocked. Morphological and ultrastructure analysis demonstrated that BghiP also induces ER stress, characterized by the dilated ER cisternae and the overexpression of PERK and CHOP genes (p < 0.05). Moreover, the halt of cell proliferation and the ER stress are both associated to the increase of pro-inflammatory cytokines (IL-6 and IL-8) and the cell survival in response to microenvironmental cues. These responses induced by BghiP on bronchial cells open new horizons on the research of other biological effects induced by environmental pollutants.

miR-21 differentially regulates IL-1ß and IL-10 expression in human decidual cells infected with streptococcus B.

Intrauterine infections caused by bacteria like group B streptococcus (GBS) and the subsequent activation of the maternal inflammatory response have been long suspected to be the underlying cause of preterm labor. The inflammatory network triggered by maternal decidua has been widely described and includes the secretion of pro- and anti-inflammatory cytokines as IL-1ß and IL-10; however, the mechanisms that regulate their secretion have not been completely elucidated. MicroRNAs (miRNAs) are critical modulators of the inflammatory response by regulating cytokine expression in several cell types. Here, we explored the role of miR-21 in the expression of IL-1ß and IL-10 in human decidual stromal cells (DSCs) exposed in vitro to GBS. We observed that IL1B and IL10 expression at the mRNA level was increased in DSCs after GBS infection. IL-10 but not IL-1ß secretion was detected in the culture supernatants. We found a higher miR-21 expression (22-fold) in infected DSCs as compared with non-infected cells. miR-21 functional analysis revealed that DSCs transfected with an antagomiR vs. miR-21 significantly increased the secretion of IL-1ß but decreased that of IL-10 in DSCs cells infected with GBS. Our results suggest that miR-21 participates in balancing the inflammatory response in infected decidua through at least IL-1ß and IL-10 regulation. This is the first study attributing a functional role of miR-21 in the regulation of key molecules involved in the inflammatory response in infected DSCs, providing new insights into the epigenetic control of human decidual inflammation.

piRNAs: nature, biogenesis, regulation, and their potential clinical utility / piRNAs: naturaleza, biogénesis, regulación y utilidad clínica potencial

Abstract RNAs that interact with PIWI (P-element Induced Wimpy) proteins, called piRNAs, were discovered in 2006. Considered the "guardians of the genome," piRNAs were first described in germ cells of Mus musculus and Drosophila melanogaster. Since then, studies have focused on elucidating their origin, biogenesis, and mechanisms of action. Today, we know some of the molecules that participate in these processes, but the nature of the molecular processes that they perform remains largely unknown. However, recent studies have demonstrated that both the piRNAs and their associated proteins are also expressed in somatic cells, suggesting that their scope of action is much greater than initially thought. In addition, their union to PIWI proteins generates a silencing complex that represses the transcriptional and post-transcriptional expression of repeated sequences, including elements known as "transposables". Finally, a recent discovery revealed that this complex could modulate the silencing of specific messenger RNAs (mRNA) necessary for cell regulation. The regulatory function that piRNAs perform in various cellular processes has led to a diversification in their study concerning various diseases, including cancer, where there are indications of their potential function as diagnostic tools, biomarkers for prognoses, and future therapeutic targets. Recently, changes in piRNAs expression have been observed in diseases related to air pollution exposition, such as respiratory diseases.

Resumen Los RNA que interactúan con las proteínas PIWI (P-element Induced Wimpy), conocidos como piRNA, fueron descubiertos en 2006. Desde entonces, los estudios se han enfocado en dilucidar su origen, biogénesis y mecanismos de acción. En la actualidad se conocen algunas de las moléculas que participan en estos procesos. Sin embargo, los procesos moleculares que estas llevan a cabo aún se desconocen. Considerados como los «guardianes del genoma¼, los piRNA inicialmente se describieron en células germinales de Mus musculus y Drosophila melanogaster, pero los estudios recientes han demostrado que tanto los piRNA como sus proteínas asociadas se expresan también en células somáticas, lo que sugiere que la acción de los piRNA es mayor de lo que antes se pensaba. Además, su unión con las proteínas PIWI genera un complejo de silenciamiento que reprime la expresión de manera transcripcional y postranscripcional de secuencias repetidas, Áincluyendo elementos conocidos como «transponibles¼. Por último, un descubrimiento ha demostrado que este complejo puede modular el silenciamiento de ciertos RNA mensajeros necesarios para la regulación celular. La función reguladora de los piRNA en múltiples procesos celulares ha contribuido a la diversificación de su estudio en diferentes enfermedades, incluyendo el cáncer, en el que hay indicaciones de su potencial función como herramientas de diagnóstico, biomarcadores de pronóstico y, en un futuro, dianas terapéuticas. Recientemente se han observado cambios en la expresión de piRNA en enfermedades relacionadas con la exposición a contaminantes ambientales, como las enfermedades respiratorias.

piRNAs: nature, biogenesis, regulation, and their potential clinical utility.

RNAs that interact with PIWI (P-element Induced Wimpy) proteins, called piRNAs, were discovered in 2006. Considered the "guardians of the genome," piRNAs were first described in germ cells of Mus musculus and Drosophila melanogaster. Since then, studies have focused on elucidating their origin, biogenesis, and mechanisms of action. Today, we know some of the molecules that participate in these processes, but the nature of the molecular processes that they perform remains largely unknown. However, recent studies have demonstrated that both the piRNAs and their associated proteins are also expressed in somatic cells, suggesting that their scope of action is much greater than initially thought. In addition, their union to PIWI proteins generates a silencing complex that represses the transcriptional and post-transcriptional expression of repeated sequences, including elements known as "transposables". Finally, a recent discovery revealed that this complex could modulate the silencing of specific messenger RNAs (mRNA) necessary for cell regulation. The regulatory function that piRNAs perform in various cellular processes has led to a diversification in their study concerning various diseases, including cancer, where there are indications of their potential function as diagnostic tools, biomarkers for prognoses, and future therapeutic targets. Recently, changes in piRNAs expression have been observed in diseases related to air pollution exposition, such as respiratory diseases.

Los RNA que interactúan con las proteínas PIWI (P-element Induced Wimpy), conocidos como piRNA, fueron descubiertos en 2006. Desde entonces, los estudios se han enfocado en dilucidar su origen, biogénesis y mecanismos de acción. En la actualidad se conocen algunas de las moléculas que participan en estos procesos. Sin embargo, los procesos moleculares que estas llevan a cabo aún se desconocen. Considerados como los «guardianes del genoma¼, los piRNA inicialmente se describieron en células germinales de Mus musculus y Drosophila melanogaster, pero los estudios recientes han demostrado que tanto los piRNA como sus proteínas asociadas se expresan también en células somáticas, lo que sugiere que la acción de los piRNA es mayor de lo que antes se pensaba. Además, su unión con las proteínas PIWI genera un complejo de silenciamiento que reprime la expresión de manera transcripcional y postranscripcional de secuencias repetidas, ­incluyendo elementos conocidos como «transponibles¼. Por último, un descubrimiento ha demostrado que este complejo puede modular el silenciamiento de ciertos RNA mensajeros necesarios para la regulación celular. La función reguladora de los piRNA en múltiples procesos celulares ha contribuido a la diversificación de su estudio en diferentes enfermedades, incluyendo el cáncer, en el que hay indicaciones de su potencial función como herramientas de diagnóstico, biomarcadores de pronóstico y, en un futuro, dianas terapéuticas. Recientemente se han observado cambios en la expresión de piRNA en enfermedades relacionadas con la exposición a contaminantes ambientales, como las enfermedades respiratorias.

Pseudomonas aeruginosa induces spatio-temporal secretion of IL-1ß, TNFα, proMMP-9, and reduction of epithelial E-cadherin in human alveolar epithelial type II (A549) cells.

Pseudomonas aeruginosa, is an opportunistic bacterium with a high prevalence in diverse pulmonary infections. Although several genes are involved in the system of resistance and evasion of the immunological response of the host, little is known about the inflammatory, degradative, and cell-binding response induced by P. aeruginosa in human lung alveolar epithelial cells. The purpose of this study was to determine the cytokine expression (IL-1ß and TNFα), pro matrix metalloproteinases activation (proMMP-2 and proMMP-9), and the effects on the cell-binding adhesion protein (E-cadherin) in an in vitro model of human lung alveolar epithelial cells. A549 cells were stimulated with a different number of colony-forming units of P. aeruginosa for 3, 6, and 24 hours. Subsequently, the culture medium was collected, IL-1ß and TNFα levels were evaluated by ELISA; proMMP-2 and -9 levels were determined by substrate gel zymography, and the MMP-9 and E-cadherin assessed by immunostaining of A549 cells. Our results demonstrated that P. aeruginosa induces mainly the secretion of TNFα, increases actMMP-9 level, and significantly reduces the level of E-cadherin in the A549 cells. In summary, the inflammatory/degradative process induced by P. aeruginosa modulates the expression of the E-cadherin protein. The probable clinical implications of this study suggest the use of inhibitors that reduce the degradative activity of proMMP-9 which will be further explored in the next phase of this study.

Role of aryl hydrocarbon receptor in central nervous system tumors: Biological and therapeutic implications.

Aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor, whose canonical pathway mainly regulates the genes involved in xenobiotic metabolism. However, it can also regulate several responses in a non-canonical manner, such as proliferation, differentiation, cell death and cell adhesion. AhR plays an important role in central nervous system tumors, as it can regulate several cellular responses via different pathways. The polymorphisms of the AHR gene have been associated with the development of gliomas. In addition, the metabolism of tumor cells promotes tumor growth, particularly in tryptophan synthesis, where some metabolites, such as kynurenine, can activate the AhR pathway, triggering cell proliferation in astrocytomas, medulloblastomas and glioblastomas. Furthermore, as part of the changes in neuroblastomas, AHR is able to downregulate the expression of proto-oncogene c-Myc, induce differentiation in tumor cells, and cause cell cycle arrest and apoptosis. Collectively, these data suggested that the modulation of the AhR pathway may downregulate tumor growth, providing a novel strategy for applications for the treatment of certain tumors through the control of the AhR pathway.

Robinsonecio gerberifolius as a sentinel organism for atmospheric pollution by heavy metals in several sites of Mexico city and its metropolitan area.

Evaluate the effect of heavy metals (HM) on sentinel organisms such as vascular plants represent a model to estimate toxic hazard due to environmental pollution. In the present study, the plant Robinsonecio gerberifolius was used to evaluate the toxic effects of the HM contained in the leaves of plants that were exposed to 4 different sites in Mexico city and its metropolitan area, during the rainy and dry seasons in the period 2017-2019. The comet assay to evaluate genotoxicity revealed an increase with respect to control (p < 0.05), in 2nd and 8th week of exposure, in all 4 study sites and in both seasons, more significant in the rainy period. An increase in the induction of oxidative stress was also observed in the exposed leaves from the 4 study sites when compared with the control; in some cases, the increases were significant (p < 0.05). In general, α- and ß-carotenoids were increased at 8th week of exposure, in all plants exposed in both seasons, while miR398 increased in plants exposed in 2 study sites (p < 0.05). Finally, toxic HM like aluminum, vanadium, and cadmium, increased significantly in the rainy season, while lead increased in the dry season. We conclude that R. gerberifolius can be considered a sentinel plant for evaluating the presence and general toxic effects caused by the presence of toxic HM that have been documented in the atmosphere of Mexico City and its metropolitan area.

Evaluation of the melting temperature of TaqMan probes as a genotyping method for IDH1, IDH2, and H3F3A in pediatric astrocytomas / Evaluación del método de temperatura de disociación de sondas TaqMan para la genotipificación de IDH1, IDH2 y H3F3A en astrocitomas pediátricos

Abstract Background: Astrocytomas are cancer tumors of the central nervous system and represent the most common type of solid tumors during human childhood. In 2016, the World Health Organization established a molecular classification system to regroup tumor entities to achieve a more accurate diagnosis and a better clinical decision-making and selection of treatment in patients with these types of tumors. Methods: We evaluated a genotyping assay for rapid and cost-effective mutation detection in astrocytomas using TaqMan probes in an asymmetric polymerase chain reaction (PCR) assay. Results: Four diffuse astrocytomas (Grade II), three anaplastic astrocytomas (Grade III), and four glioblastomas (Grade IV) were sequenced, and all of them displayed the wild-type (WT) sequence. We tried to set up this melting analysis for the genotyping of pediatric astrocytomas by identifying the specific melting temperatures of the TaqMan probes due to the presence of the WT sequences in the isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) and H3.3 histone A genes (H3F3A). We used an IDH1-TaqMan probe to identify the WT status of IDH1 in two different WT deoxyribonucleic acid (DNA) templates (pilocytic and diffuse astrocytoma) and obtained four melting temperature values ranged from 65.6 to 92.2°C. Furthermore, only four out of 29 reactions displayed amplification of the DNA template. Sanger sequencing was faster and more reliable to detect the gene status in all the sequenced samples. Conclusions: We conclude that conventional Sanger sequencing remains the gold standard for the genotyping of pediatric astrocytomas.

Resumen Introducción: Los astrocitomas son un tipo de cáncer que afecta al sistema nervioso central y representan el tumor sólido más común durante la infancia. En el año 2016, la Organización Mundial de la Salud estableció un sistema de clasificación molecular para reagrupar tumores con identidades genéticas similares y lograr un diagnóstico más preciso, lo que lleva a tomar las decisiones clínicas idóneas al elegir el tratamiento de pacientes con este tipo de tumores. Métodos: Se evaluó un protocolo que involucra el uso de sondas TaqMan en un ensayo de reacción en cadena de la polimerasa asimétrica para la detección de mutaciones en astrocitomas. Se secuenciaron cuatro astrocitomas difusos (Grado II), tres astrocitomas anaplásicos (Grado III) y cuatro glioblastomas (Grado IV). Se intentó establecer las condiciones del análisis para la genotipificación de los astrocitomas pediátricos mediante la identificación de las temperaturas de disociación específicas de las sondas TaqMan producidas por la prescencia de las secuancias WT en los genes isocitrato deshidrogenasa 1 y 2 (IDH1, IDH2) y H3.3 histona A (H3F3A). Resultados: Los astrocitomas mostraron la secuencia wild type (WT) (silvestre) de los genes. Se utilizó una sonda TaqMan IDH1 para identificar el estado de este gen en dos templados WT de DNA (astrocitoma pilocítico y difuso) y se obtuvieron cuatro valores de temperatura de disociación (65.6-92.2 °C). Solo cuatro de las 29 reacciones mostraron amplificación de DNA. La secuenciación de Sanger fue más rápida y confiable para detectar el estado de los genes en todas las muestras. Conclusiones: La secuenciación de Sanger sigue siendo la técnica más práctica para la genotipificación de astrocitomas pediátricos.

Evaluation of the melting temperature of TaqMan probes as a genotyping method for IDH1, IDH2, and H3F3A in pediatric astrocytomas.

Background: Astrocytomas are cancer tumors of the central nervous system and represent the most common type of solid tumors during human childhood. In 2016, the World Health Organization established a molecular classification system to regroup tumor entities to achieve a more accurate diagnosis and a better clinical decision-making and selection of treatment in patients with these types of tumors. Methods: We evaluated a genotyping assay for rapid and cost-effective mutation detection in astrocytomas using TaqMan probes in an asymmetric polymerase chain reaction (PCR) assay. Results: Four diffuse astrocytomas (Grade II), three anaplastic astrocytomas (Grade III), and four glioblastomas (Grade IV) were sequenced, and all of them displayed the wild-type (WT) sequence. We tried to set up this melting analysis for the genotyping of pediatric astrocytomas by identifying the specific melting temperatures of the TaqMan probes due to the presence of the WT sequences in the isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) and H3.3 histone A genes (H3F3A). We used an IDH1-TaqMan probe to identify the WT status of IDH1 in two different WT deoxyribonucleic acid (DNA) templates (pilocytic and diffuse astrocytoma) and obtained four melting temperature values ranged from 65.6 to 92.2°C. Furthermore, only four out of 29 reactions displayed amplification of the DNA template. Sanger sequencing was faster and more reliable to detect the gene status in all the sequenced samples. Conclusions: We conclude that conventional Sanger sequencing remains the gold standard for the genotyping of pediatric astrocytomas.

Introducción: Los astrocitomas son un tipo de cáncer que afecta al sistema nervioso central y representan el tumor sólido más común durante la infancia. En el año 2016, la Organización Mundial de la Salud estableció un sistema de clasificación molecular para reagrupar tumores con identidades genéticas similares y lograr un diagnóstico más preciso, lo que lleva a tomar las decisiones clínicas idóneas al elegir el tratamiento de pacientes con este tipo de tumores. Métodos: Se evaluó un protocolo que involucra el uso de sondas TaqMan en un ensayo de reacción en cadena de la polimerasa asimétrica para la detección de mutaciones en astrocitomas. Se secuenciaron cuatro astrocitomas difusos (Grado II), tres astrocitomas anaplásicos (Grado III) y cuatro glioblastomas (Grado IV). Se intentó establecer las condiciones del análisis para la genotipificación de los astrocitomas pediátricos mediante la identificación de las temperaturas de disociación específicas de las sondas TaqMan producidas por la prescencia de las secuancias WT en los genes isocitrato deshidrogenasa 1 y 2 (IDH1, IDH2) y H3.3 histona A (H3F3A). Resultados: Los astrocitomas mostraron la secuencia wild type (WT) (silvestre) de los genes. Se utilizó una sonda TaqMan IDH1 para identificar el estado de este gen en dos templados WT de DNA (astrocitoma pilocítico y difuso) y se obtuvieron cuatro valores de temperatura de disociación (65.6-92.2 °C). Solo cuatro de las 29 reacciones mostraron amplificación de DNA. La secuenciación de Sanger fue más rápida y confiable para detectar el estado de los genes en todas las muestras. Conclusiones: La secuenciación de Sanger sigue siendo la técnica más práctica para la genotipificación de astrocitomas pediátricos.