The sole DNA ligase in entamoeba histolytica is a high-fidelity DNA ligase involved in DNA damage repair

"The protozoan parasite Entamoeba histolytica is exposed to reactive oxygen and nitric oxide species that have the potential to damage its genome. E. histolytica harbors enzymes involved in DNA repair pathways like Base and Nucleotide Excision Repair. The majority of DNA repairs pathways converge in their final step in which a DNA ligase seals the DNA nicks. In contrast to other eukaryotes, the genome of E. histolyticaencodes only one DNA ligase (EhDNAligI), suggesting that this ligase is involved in both DNA replication and DNA repair. Therefore, the aim of this work was to characterize EhDNAligI, its ligation fidelity and its ability to ligate opposite DNA mismatches and oxidative DNA lesions, and to study its expression changes and localization during and after recovery from UV and H2O2 treatment. We found that EhDNAligI is a high-fidelity DNA ligase on canonical substrates and is able to discriminate erroneous base-pairing opposite DNA lesions. EhDNAligI expression decreases after DNA damage induced by UV and H2O2 treatments, but it was upregulated during recovery time. Upon oxidative DNA damage, EhDNAligI relocates into the nucleus where it co-localizes with EhPCNA and the 8-oxoG adduct. The appearance and disappearance of 8-oxoG during and after both treatments suggest that DNA damaged was efficiently repaired because the mainly NER and BER components are expressed in this parasite and some of them were modulated after DNA insults. All these data disclose the relevance of EhDNAligI as a specialized and unique ligase in E. histolytica that may be involved in DNA repair of the 8-oxoG lesions.

First Latin American clinical practice guidelines for the treatment of systemic lupus erythematosus: Latin American Group for the Study of Lupus (GLADEL, Grupo Latino Americano de Estudio del Lupus)-Pan-American League of Associations of Rheumatology (PANLAR)

Systemic lupus erythematosus (SLE), a complex and heterogeneous autoimmune disease, represents a significant challenge for both diagnosis and treatment. Patients with SLE in Latin America face special problems that should be considered when therapeutic guidelines are developed. The objective of the study is to develop clinical practice guidelines for Latin American patients with lupus. Two independent teams (rheumatologists with experience in lupus management and methodologists) had an initial meeting in Panama City, Panama, in April 2016. They selected a list of questions for the clinical problems most commonly seen in Latin American patients with SLE. These were addressed with the best available evidence and summarised in a standardised format following the Grading of Recommendations Assessment, Development and Evaluation approach. All preliminary findings were discussed in a second face-to-face meeting in Washington, DC, in November 2016. As a result, nine organ/system sections are presented with the main findings; an 'overarching' treatment approach was added. Special emphasis was made on regional implementation issues. Best pharmacologic options were examined for musculoskeletal, mucocutaneous, kidney, cardiac, pulmonary, neuropsychiatric, haematological manifestations and the antiphospholipid syndrome. The roles of main therapeutic options (ie, glucocorticoids, antimalarials, immunosuppressant agents, therapeutic plasma exchange, belimumab, rituximab, abatacept, low-dose aspirin and anticoagulants) were summarised in each section. In all cases, benefits and harms, certainty of the evidence, values and preferences, feasibility, acceptability and equity issues were considered to produce a recommendation with special focus on ethnic and socioeconomic aspects. Guidelines for Latin American patients with lupus have been developed and could be used in similar settings.Fil: Pons Estel, Bernardo A.. Centro Regional de Enfermedades Autoinmunes y Reumáticas; ArgentinaFil: Bonfa, Eloisa. Universidade de Sao Paulo; BrasilFil: Soriano, Enrique R.. Instituto Universitario Hospital Italiano de Buenos Aires. Rectorado.; ArgentinaFil: Cardiel, Mario H.. Centro de Investigación Clínica de Morelia; MéxicoFil: Izcovich, Ariel. Hospital Alemán; ArgentinaFil: Popoff, Federico. Hospital Aleman; ArgentinaFil: Criniti, Juan M.. Hospital Alemán; ArgentinaFil: Vásquez, Gloria. Universidad de Antioquia; ColombiaFil: Massardo, Loreto. Universidad San Sebastián; ChileFil: Duarte, Margarita. Hospital de Clínicas; ParaguayFil: Barile Fabris, Leonor A.. Hospital Angeles del Pedregal; MéxicoFil: García, Mercedes A.. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Amigo, Mary Carmen. Centro Médico Abc; MéxicoFil: Espada, Graciela. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Catoggio, Luis J.. Hospital Italiano. Instituto Universitario. Escuela de Medicina; ArgentinaFil: Sato, Emilia Inoue. Universidade Federal de Sao Paulo; BrasilFil: Levy, Roger A.. Universidade do Estado de Rio do Janeiro; BrasilFil: Acevedo Vásquez, Eduardo M.. Universidad Nacional Mayor de San Marcos; PerúFil: Chacón Díaz, Rosa. Policlínica Méndez Gimón; VenezuelaFil: Galarza Maldonado, Claudio M.. Corporación Médica Monte Sinaí; EcuadorFil: Iglesias Gamarra, Antonio J.. Universidad Nacional de Colombia; ColombiaFil: Molina, José Fernando. Centro Integral de Reumatología; ColombiaFil: Neira, Oscar. Universidad de Chile; ChileFil: Silva, Clóvis A.. Universidade de Sao Paulo; BrasilFil: Vargas Peña, Andrea. Hospital Pasteur Montevideo; UruguayFil: Gómez Puerta, José A.. Hospital Clinic Barcelona; EspañaFil: Scolnik, Marina. Instituto Universitario Hospital Italiano de Buenos Aires. Rectorado.; ArgentinaFil: Pons Estel, Guillermo J.. Centro Regional de Enfermedades Autoinmunes y Reumáticas; Argentina. Hospital Provincial de Rosario; ArgentinaFil: Ugolini Lopes, Michelle R.. Universidade de Sao Paulo; BrasilFil: Savio, Verónica. Instituto Universitario Hospital Italiano de Buenos Aires. Rectorado.; ArgentinaFil: Drenkard, Cristina. University of Emory; Estados UnidosFil: Alvarellos, Alejandro J.. Hospital Privado Universitario de Córdoba; ArgentinaFil: Ugarte Gil, Manuel F.. Universidad Cientifica del Sur; Perú. Hospital Nacional Guillermo Almenara Irigoyen; PerúFil: Babini, Alejandra. Instituto Universitario Hospital Italiano de Buenos Aires. Rectorado.; ArgentinaFil: Cavalcanti, André. Universidade Federal de Pernambuco; BrasilFil: Cardoso Linhares, Fernanda Athayde. Hospital Pasteur Montevideo; UruguayFil: Haye Salinas, Maria Jezabel. Hospital Privado Universitario de Córdoba; ArgentinaFil: Fuentes Silva, Yurilis J.. Universidad de Oriente - Núcleo Bolívar; VenezuelaFil: Montandon De Oliveira E Silva, Ana Carolina. Universidade Federal de Goiás; BrasilFil: Eraso Garnica, Ruth M.. Universidad de Antioquia; ColombiaFil: Herrera Uribe, Sebastián. Hospital General de Medellin Luz Castro de Gutiérrez; ColombiaFil: Gómez Martín, DIana. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Robaina Sevrini, Ricardo. Universidad de la República; UruguayFil: Quintana, Rosana M.. Hospital Provincial de Rosario; Argentina. Centro Regional de Enfermedades Autoinmunes y Reumáticas; ArgentinaFil: Gordon, Sergio. Hospital Interzonal General de Agudos Dr Oscar Alende. Unidad de Reumatología y Enfermedades Autoinmunes Sistémicas; ArgentinaFil: Fragoso Loyo, Hilda. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Rosario, Violeta. Hospital Docente Padre Billini; República DominicanaFil: Saurit, Verónica. Hospital Privado Universitario de Córdoba; ArgentinaFil: Appenzeller, Simone. Universidade Estadual de Campinas; BrasilFil: Dos Reis Neto, Edgard Torres. Universidade Federal de Sao Paulo; BrasilFil: Cieza, Jorge. Hospital Nacional Edgardo Rebagliati Martins; PerúFil: González Naranjo, Luis A.. Universidad de Antioquia; ColombiaFil: González Bello, Yelitza C.. Ceibac; MéxicoFil: Collado, María Victoria. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Sarano, Judith. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Retamozo, Maria Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Ciencias de la Salud. Universidad Nacional de Córdoba. Instituto de Investigaciones en Ciencias de la Salud; ArgentinaFil: Sattler, María E.. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Gamboa Cárdenas, Rocio V.. Hospital Nacional Guillermo Almenara Irigoyen; PerúFil: Cairoli, Ernesto. Universidad de la República; UruguayFil: Conti, Silvana M.. Hospital Provincial de Rosario; ArgentinaFil: Amezcua Guerra, Luis M.. Instituto Nacional de Cardiologia Ignacio Chavez; MéxicoFil: Silveira, Luis H.. Instituto Nacional de Cardiologia Ignacio Chavez; MéxicoFil: Borba, Eduardo F.. Universidade de Sao Paulo; BrasilFil: Pera, Mariana A.. Hospital Interzonal General de Agudos General San Martín; ArgentinaFil: Alba Moreyra, Paula B.. Universidad Nacional de Córdoba. Facultad de Medicina; ArgentinaFil: Arturi, Valeria. Hospital Interzonal General de Agudos General San Martín; ArgentinaFil: Berbotto, Guillermo A.. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Gerling, Cristian. Hospital Interzonal General de Agudos Dr Oscar Alende. Unidad de Reumatología y Enfermedades Autoinmunes Sistémicas; ArgentinaFil: Gobbi, Carla Andrea. Universidad Nacional de Córdoba. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gervasoni, Viviana L.. Hospital Provincial de Rosario; ArgentinaFil: Scherbarth, Hugo R.. Hospital Interzonal General de Agudos Dr Oscar Alende. Unidad de Reumatología y Enfermedades Autoinmunes Sistémicas; ArgentinaFil: Brenol, João C. Tavares. Hospital de Clinicas de Porto Alegre; BrasilFil: Cavalcanti, Fernando. Universidade Federal de Pernambuco; BrasilFil: Costallat, Lilian T. Lavras. Universidade Estadual de Campinas; BrasilFil: Da Silva, Nilzio A.. Universidade Federal de Goiás; BrasilFil: Monticielo, Odirlei A.. Hospital de Clinicas de Porto Alegre; BrasilFil: Seguro, Luciana Parente Costa. Universidade de Sao Paulo; BrasilFil: Xavier, Ricardo M.. Hospital de Clinicas de Porto Alegre; BrasilFil: Llanos, Carolina. Universidad Católica de Chile; ChileFil: Montúfar Guardado, Rubén A.. Instituto Salvadoreño de la Seguridad Social; El SalvadorFil: Garcia De La Torre, Ignacio. Hospital General de Occidente; MéxicoFil: Pineda, Carlos. Instituto Nacional de Rehabilitación; MéxicoFil: Portela Hernández, Margarita. Umae Hospital de Especialidades Centro Medico Nacional Siglo Xxi; MéxicoFil: Danza, Alvaro. Hospital Pasteur Montevideo; UruguayFil: Guibert Toledano, Marlene. Medical-surgical Research Center; CubaFil: Reyes, Gil Llerena. Medical-surgical Research Center; CubaFil: Acosta Colman, Maria Isabel. Hospital de Clínicas; ParaguayFil: Aquino, Alicia M.. Hospital de Clínicas; ParaguayFil: Mora Trujillo, Claudia S.. Hospital Nacional Edgardo Rebagliati Martins; PerúFil: Muñoz Louis, Roberto. Hospital Docente Padre Billini; República DominicanaFil: García Valladares, Ignacio. Centro de Estudios de Investigación Básica y Clínica; MéxicoFil: Orozco, María Celeste. Instituto de Rehabilitación Psicofísica; ArgentinaFil: Burgos, Paula I.. Pontificia Universidad Católica de Chile; ChileFil: Betancur, Graciela V.. Instituto de Rehabilitación Psicofísica; ArgentinaFil: Alarcón, Graciela S.. Universidad Peruana Cayetano Heredia; Perú. University of Alabama at Birmingahm; Estados Unido

La renovación de la palabra en el bicentenario de la Argentina : los colores de la mirada lingüística

El libro reúne trabajos en los que se exponen resultados de investigaciones presentadas por investigadores de Argentina, Chile, Brasil, España, Italia y Alemania en el XII Congreso de la Sociedad Argentina de Lingüística (SAL), Bicentenario: la renovación de la palabra, realizado en Mendoza, Argentina, entre el 6 y el 9 de abril de 2010. Las temáticas abordadas en los 167 capítulos muestran las grandes líneas de investigación que se desarrollan fundamentalmente en nuestro país, pero también en los otros países mencionados arriba, y señalan además las áreas que recién se inician, con poca tradición en nuestro país y que deberían fomentarse. Los trabajos aquí publicados se enmarcan dentro de las siguientes disciplinas y/o campos de investigación: Fonología, Sintaxis, Semántica y Pragmática, Lingüística Cognitiva, Análisis del Discurso, Psicolingüística, Adquisición de la Lengua, Sociolingüística y Dialectología, Didáctica de la lengua, Lingüística Aplicada, Lingüística Computacional, Historia de la Lengua y la Lingüística, Lenguas Aborígenes, Filosofía del Lenguaje, Lexicología y Terminología

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation

Aggregation kinetic dataset to determine the stability of the purified and refolded recombinant ppTvCP4 protein of Trichomonas vaginalis

The recombinant ppTvCP4 (ppTvCP4r) protein, a specific inhibitor of the proteolytic activity and virulence properties of Trichomonas vaginalis, depending on cathepsin L-like cysteine proteinases (CPs) (http:dx.doi.org/ 10.1016/j.biocel.2014.12.001 [1], http:dx.doi.org/ 10.1016/j.micinf.2013.09.002 [2], http:dx.doi.org/ 10.1155/2015/946787 [3]) was stable in the elution buffer up to two months at 4 °C. However, it was prone to aggregate in PBS (functional assay buffer) [1]. Therefore, before functional assays, the aggregation kinetic of refolded ppTvCP4r was determined after the exchange to PBS. Samples of purified and refolded ppTvCP4r (0.15 mg/ml) in PBS were incubated for 0–24 h at 4 and 25 °C, spun down, measured the protein concentration in the supernatant and checked for the presence of aggregated protein in the pellet. The concentration of protein progressively decreased in the supernatant through time at both temperatures as the protein aggregated. Data in this article are related to the research paper [1]. Keywords: PpTvCP4r, Buffer exchange, Protein aggregation, Trichomonas vaginali

Dataset of cathepsin L-like CP inhibition of Naegleria fowleri and Acanthamoeba castellanii by ppTvCP4r from Trichomonas vaginalis

The recombinant TvCP4 prepro region (ppTvCP4r) acts as an exogenous inhibitor of cathepsin L-like CPs from Trichomonas vaginalis (Cárdenas-Guerra et al., 2015 [1]). Here, we present the dataset of the trichomonad ppTvCP4r inhibitory effect against the CP proteolytic activities from other microorganisms, such as Naegleria fowleri and Acanthamoeba castellanii free-living amoeba. The proteolytic activity inhibition of total crude extracts (TCEs) of N. fowleri and A. castellanii was determined and recorded using a fluorogenic substrate specific for cathepsin L CPs without or with a ppTvCP4r treatment at different concentrations and pH. Keywords: Acanthamoeba castellanii, Cathepsin L-like CPs, Cysteine proteinase inhibitors, Naegleria fowleri, ppTvCP4r, Trichomonas vaginali

Image_3_The Sole DNA Ligase in Entamoeba histolytica Is a High-Fidelity DNA Ligase Involved in DNA Damage Repair.JPEG

<p>The protozoan parasite Entamoeba histolytica is exposed to reactive oxygen and nitric oxide species that have the potential to damage its genome. E. histolytica harbors enzymes involved in DNA repair pathways like Base and Nucleotide Excision Repair. The majority of DNA repairs pathways converge in their final step in which a DNA ligase seals the DNA nicks. In contrast to other eukaryotes, the genome of E. histolytica encodes only one DNA ligase (EhDNAligI), suggesting that this ligase is involved in both DNA replication and DNA repair. Therefore, the aim of this work was to characterize EhDNAligI, its ligation fidelity and its ability to ligate opposite DNA mismatches and oxidative DNA lesions, and to study its expression changes and localization during and after recovery from UV and H₂O₂ treatment. We found that EhDNAligI is a high-fidelity DNA ligase on canonical substrates and is able to discriminate erroneous base-pairing opposite DNA lesions. EhDNAligI expression decreases after DNA damage induced by UV and H₂O₂ treatments, but it was upregulated during recovery time. Upon oxidative DNA damage, EhDNAligI relocates into the nucleus where it co-localizes with EhPCNA and the 8-oxoG adduct. The appearance and disappearance of 8-oxoG during and after both treatments suggest that DNA damaged was efficiently repaired because the mainly NER and BER components are expressed in this parasite and some of them were modulated after DNA insults. All these data disclose the relevance of EhDNAligI as a specialized and unique ligase in E. histolytica that may be involved in DNA repair of the 8-oxoG lesions.</p

Image_2_The Sole DNA Ligase in Entamoeba histolytica Is a High-Fidelity DNA Ligase Involved in DNA Damage Repair.JPEG

<p>The protozoan parasite Entamoeba histolytica is exposed to reactive oxygen and nitric oxide species that have the potential to damage its genome. E. histolytica harbors enzymes involved in DNA repair pathways like Base and Nucleotide Excision Repair. The majority of DNA repairs pathways converge in their final step in which a DNA ligase seals the DNA nicks. In contrast to other eukaryotes, the genome of E. histolytica encodes only one DNA ligase (EhDNAligI), suggesting that this ligase is involved in both DNA replication and DNA repair. Therefore, the aim of this work was to characterize EhDNAligI, its ligation fidelity and its ability to ligate opposite DNA mismatches and oxidative DNA lesions, and to study its expression changes and localization during and after recovery from UV and H₂O₂ treatment. We found that EhDNAligI is a high-fidelity DNA ligase on canonical substrates and is able to discriminate erroneous base-pairing opposite DNA lesions. EhDNAligI expression decreases after DNA damage induced by UV and H₂O₂ treatments, but it was upregulated during recovery time. Upon oxidative DNA damage, EhDNAligI relocates into the nucleus where it co-localizes with EhPCNA and the 8-oxoG adduct. The appearance and disappearance of 8-oxoG during and after both treatments suggest that DNA damaged was efficiently repaired because the mainly NER and BER components are expressed in this parasite and some of them were modulated after DNA insults. All these data disclose the relevance of EhDNAligI as a specialized and unique ligase in E. histolytica that may be involved in DNA repair of the 8-oxoG lesions.</p

Table_2_The Sole DNA Ligase in Entamoeba histolytica Is a High-Fidelity DNA Ligase Involved in DNA Damage Repair.DOCX

<p>The protozoan parasite Entamoeba histolytica is exposed to reactive oxygen and nitric oxide species that have the potential to damage its genome. E. histolytica harbors enzymes involved in DNA repair pathways like Base and Nucleotide Excision Repair. The majority of DNA repairs pathways converge in their final step in which a DNA ligase seals the DNA nicks. In contrast to other eukaryotes, the genome of E. histolytica encodes only one DNA ligase (EhDNAligI), suggesting that this ligase is involved in both DNA replication and DNA repair. Therefore, the aim of this work was to characterize EhDNAligI, its ligation fidelity and its ability to ligate opposite DNA mismatches and oxidative DNA lesions, and to study its expression changes and localization during and after recovery from UV and H₂O₂ treatment. We found that EhDNAligI is a high-fidelity DNA ligase on canonical substrates and is able to discriminate erroneous base-pairing opposite DNA lesions. EhDNAligI expression decreases after DNA damage induced by UV and H₂O₂ treatments, but it was upregulated during recovery time. Upon oxidative DNA damage, EhDNAligI relocates into the nucleus where it co-localizes with EhPCNA and the 8-oxoG adduct. The appearance and disappearance of 8-oxoG during and after both treatments suggest that DNA damaged was efficiently repaired because the mainly NER and BER components are expressed in this parasite and some of them were modulated after DNA insults. All these data disclose the relevance of EhDNAligI as a specialized and unique ligase in E. histolytica that may be involved in DNA repair of the 8-oxoG lesions.</p

Image_1_The Sole DNA Ligase in Entamoeba histolytica Is a High-Fidelity DNA Ligase Involved in DNA Damage Repair.JPEG

<p>The protozoan parasite Entamoeba histolytica is exposed to reactive oxygen and nitric oxide species that have the potential to damage its genome. E. histolytica harbors enzymes involved in DNA repair pathways like Base and Nucleotide Excision Repair. The majority of DNA repairs pathways converge in their final step in which a DNA ligase seals the DNA nicks. In contrast to other eukaryotes, the genome of E. histolytica encodes only one DNA ligase (EhDNAligI), suggesting that this ligase is involved in both DNA replication and DNA repair. Therefore, the aim of this work was to characterize EhDNAligI, its ligation fidelity and its ability to ligate opposite DNA mismatches and oxidative DNA lesions, and to study its expression changes and localization during and after recovery from UV and H₂O₂ treatment. We found that EhDNAligI is a high-fidelity DNA ligase on canonical substrates and is able to discriminate erroneous base-pairing opposite DNA lesions. EhDNAligI expression decreases after DNA damage induced by UV and H₂O₂ treatments, but it was upregulated during recovery time. Upon oxidative DNA damage, EhDNAligI relocates into the nucleus where it co-localizes with EhPCNA and the 8-oxoG adduct. The appearance and disappearance of 8-oxoG during and after both treatments suggest that DNA damaged was efficiently repaired because the mainly NER and BER components are expressed in this parasite and some of them were modulated after DNA insults. All these data disclose the relevance of EhDNAligI as a specialized and unique ligase in E. histolytica that may be involved in DNA repair of the 8-oxoG lesions.</p