Esteban Serra - Academia.edu (original) (raw)

Papers by Esteban Serra

Journal of Visualized Experiments, Nov 5, 2021

Trypanosoma cruzi is the causative agent of Chagas disease (ChD), an endemic disease of public he... more Trypanosoma cruzi is the causative agent of Chagas disease (ChD), an endemic disease of public health importance in Latin America that also affects many non-endemic countries due to the increase in migration. This disease affects nearly 8 million people, with new cases estimated at 50,000 per year. In the 1960s and 70s, two drugs for ChD treatment were introduced: nifurtimox and benznidazole (BZN). Both are effective in newborns and during the acute phase of the disease but not in the chronic phase, and their use is associated with important side effects. These facts underscore the urgent need to intensify the search for new drugs against T. cruzi. T. cruzi is transmitted through hematophagous insect vectors of the Reduviidae and Hemiptera families. Once in the mammalian host, it multiplies intracellularly as the non-flagellated amastigote form and differentiates into the trypomastigote, the bloodstream non-replicative infective form. Inside the insect vector, trypomastigotes transform into the epimastigote stage and multiply through binary fission. This paper describes an assay based on measuring the activity of the cytoplasmic β-galactosidase released into the culture due to parasites lysis by using the substrate, chlorophenol red β-D-galactopyranoside (CPRG). For this, the T. cruzi Dm28c strain was transfected with a β-galactosidase-overexpressing plasmid and used for in vitro pharmacological screening in epimastigote, trypomastigote, and amastigote stages. This paper also describes how to measure the enzymatic activity in cultured epimastigotes, infected Vero cells with amastigotes, and trypomastigotes released from the cultured cells using the reference drug, benznidazole, as an example. This colorimetric assay is easily performed and can be scaled to a high-throughput format and applied to other T. cruzi strains.

ACS Infectious Diseases, Apr 28, 2022

Trypanosoma cruzi is a unicellular parasite that causes Chagas disease, which is endemic in the A... more Trypanosoma cruzi is a unicellular parasite that causes Chagas disease, which is endemic in the American continent but also worldwide distributed by migratory movements. A striking feature of trypanosomatids is the polycistronic transcription associated with post-transcriptional mechanisms that regulate the levels of translatable mRNA. In this context, epigenetic regulatory mechanisms have been revealed of great importance, since they are the only ones that would control the access of RNA polymerases to chromatin. Bromodomains are epigenetic protein readers that recognize and specifically bind to acetylated lysine residues, mostly at histone proteins. There are seven coding sequences for BD-containing proteins in trypanosomatids, named TcBDF1 to TcBDF7, and a putative new protein-containing a bromodomain that was recently described. Using the Tet regulated overexpression plasmid pTcINDEX-GW and CRISPR/Cas9 genome editing we were able to demonstrate the essentiality of TcBDF2 in T cruzi. This bromodomain is located in the nucleus, through a bipartite nuclear localization signal. TcBDF2 was shown to be important for host cell invasion, amastigote replication, and differentiation from amastigotes to trypomastigotes. Overexpression of TcBDF2 diminished epimastigote replication. Also, some processes involved in pathogenesis were altered in these parasites, such as infection of mammalian cells, replication of amastigotes, and the number of trypomastigotes released from host cells. In in vitro studies, TcBDF2 was also able to bind inhibitors showing a specificity profile different from that of the previously characterized TcBDF3. These results, point to TcBDF2 as a druggable target against T. cruzi.

Molecular and Biochemical Parasitology, May 1, 1996

The CCAAT-binding factor NF-Y (CBF/CP1) is a heteromeric transcription factor involved in the reg... more The CCAAT-binding factor NF-Y (CBF/CP1) is a heteromeric transcription factor involved in the regulation of a variety of eukaryotic genes. We identified NF-Y as the CCAAT activity binding to the promoter region of the gene coding for the 28-kDa glutathione S-transferase of the human parasite Schistosoma mansoni (Sm28GST). We isolated the NF-YA cDNA from S. mansoni (SmNF-YA): the complete 268 amino acid sequence harbors a region in its C-terminal part that shows homology with the subunit interaction and DNA-binding domains of the mammalian NF-YA; the N-terminal region has an amino acid composition reminiscent of the mammalian and echinoderm counterparts, rich in glutamine and hydrophobic residues, but shows no sequence similarity at the primary level. In vitro synthesized SMNF-YA is able to associate with mammalian NF-YB/C subunits in the absence of DNA and to bind to the Sm28GST CCAAT box. Surprisingly, a monoclonal antibody directed against the non-conserved Q-rich activation domain of mammalian NF-YA supershifts and immunoprecipitates SMNF-YA, strongly suggesting structure conservation in the activation domain between divergent species.

ACS Combinatorial Science, Feb 26, 2018

A set of chemically engineered extracts enriched in compounds including N-N and N-O fragments in ... more A set of chemically engineered extracts enriched in compounds including N-N and N-O fragments in their structures was prepared. Bromodomain binding screening and bioguided fractionation led to the identification of one oxime hit that interacts with TcBDF3 with affinity in the submicromolar range and that shows interesting antiparasitic properties against the different life cycle stages of T. cruzi.

Memorias Do Instituto Oswaldo Cruz, Nov 21, 2014

We present here three expression plasmids for Trypanosoma cruzi adapted to the Gateway ® recombin... more We present here three expression plasmids for Trypanosoma cruzi adapted to the Gateway ® recombination cloning system. Two of these plasmids were designed to express trypanosomal proteins fused to a double tag for tandem affinity purification (TAPtag). The TAPtag and Gateway ® cassette were introduced into an episomal (pTEX) and an integrative (pTREX) plasmid. Both plasmids were assayed by introducing green fluorescent protein (GFP) by recombination and the integrity of the double-tagged protein was determined by western blotting and immunofluorescence microscopy. The third Gateway adapted vector assayed was the inducible pTcINDEX. When tested with GFP, pTcINDEX-GW showed a good response to tetracycline, being less leaky than its precursor (pTcINDEX).

FEBS Journal, Apr 18, 2016

The bromodomain is the only protein domain known to bind acetylated lysine. In the last few years... more The bromodomain is the only protein domain known to bind acetylated lysine. In the last few years many bromodomain inhibitors have been developed in order to treat diseases such as cancer caused by aberrant acetylation of lysine residues. We have previously characterized Trypanosoma cruzi bromodomain factor 3 (TcBDF3), a bromodomain with an atypical localization that binds acetylated a-tubulin. In the present work we show that parasites overexpressing TcBDF3 exhibit altered differentiation patterns and are less susceptible to treatment with bromodomain inhibitors. We also demonstrate that recombinant TcBDF3 is able to bind to these inhibitors in vitro in a concentration-dependant manner. In parallel, the overexpression of a mutated version of TcBDF3 negatively affects growth of epimastigotes. Recent results, including the ones presented here, suggest that bromodomain inhibitors can be conceived as a new type of anti-parasitic drug against trypanosomiasis.

Virology, Feb 1, 2010

We explored the cutaneotropic HPV genetic diversity in 71 subjects from Argentina. New generic pr... more We explored the cutaneotropic HPV genetic diversity in 71 subjects from Argentina. New generic primers (CUT) targeting 88 mucosal/cutaneous HPV were designed and compared to FAP primers. Overall, 69 different HPV types/putative types were identified, being 17 of them novel putative types. Phylogenetic analysis of partial L1 sequences grouped 2 novel putative types in the Beta-PV, 14 in the Gamma-PV and 1 in the Mu-PV genera. CUT primers showed broader capacity than FAP primers in detecting different genera/species and novel putative types (p<0.01). Using overlapping PCR, the full-length genome of a Beta-PV putative type was amplified and cloned. The new virus, designated HPV 115, encodes 5 early genes and 2 late genes. Phylogenetic analysis indicated HPV 115 as the most divergent type within the genus Beta-PV species 3. This report is the first providing data on cutaneous HPVs circulating in South America and expands our knowledge of the Papillomaviridae family.

FEBS Letters, Nov 26, 1990

The ripcniny process in tonutto fruit!; is chnr~tctcrizcd by the disnppcarancc of chloroplasts (c... more The ripcniny process in tonutto fruit!; is chnr~tctcrizcd by the disnppcarancc of chloroplasts (cp) and the formation of non-photosyt~tl~ctic chromoplasts (cr). CI diffcrcnriation involves a number of morphological and biochemical changes, including starch degradation, breakdown of chlorophyll and thylnkoid mcmbrancs, and synthesis and accu~~ulation of cnrotenoids 111, In addition, photosynthetic proteins and their corrcspondinp mRNAs arc absent or greatly diminished [2,3], These changes in the patterns of gene cxprcssion are not due to major recombination4 arrangements of the pt genomc, since restriction patterns of cp-and crDNAs are identical in tomato [2,4, §], and other s$ccics [6,7]. Two different processes contribute to regulate gene expression during chromoplast biogenesis: (a) an overall decrease (S-lo-fold) of the transcriptional activity of chromoplasts as compared to chloroplasts ([8,9], Marano and Carrillo, unpublished), that affects most plastid genes to the same extent [IO] and (b) a specific impairment in the expression of individual genes in non-photosynthetic plastids, a phenomenon that has been attributed to transcription initiation [9], transcript processing and/or stability [8,10] and translational control [ 111.

Journal of Biomedicine and Biotechnology, 2012

In the past ten years the number of acetylated proteins reported in literature grew exponentially... more In the past ten years the number of acetylated proteins reported in literature grew exponentially. Several authors have proposed that acetylation might be a key component in most eukaryotic signaling pathways, as important as phosphorylation. The enzymes involved in this process are starting to emerge; acetyltransferases and deacetylases are found inside and outside the nuclear compartment and have different regulatory functions. In trypanosomatids several of these enzymes have been described and are postulated to be novel antiparasitic targets for the rational design of drugs. In this paper we overview the most important known acetylated proteins and the advances made in the identification of new acetylated proteins using high-resolution mass spectrometry. Also, we summarize what is known so far about the acetyltransferases and deacetylases in eukaryotes, focusing on trypanosomes and their potential use as chemotherapeutic targets.

European journal of biochemistry, Aug 15, 1997

The 1241-bp promoter region of the Schistosoma mansoni 28-kDa glutathione S-transferase gene (Sm2... more The 1241-bp promoter region of the Schistosoma mansoni 28-kDa glutathione S-transferase gene (Sm28GST) was sequentially deleted and analyzed using the luciferase reporter gene system in different cell lines. The activator protein-I (AP-1) site located at-231 seems to be responsible for the major part of the promoter activity. The 1241-bp Sm28GST promoter was not, in transient transfection experiments, activated by reagents generating reactive oxygen species, such as hydrogen peroxide (Hz02), 3-methylcholanthrene, and ter-methylhydroquinone, but was significantly stimulated by phorbol 12-myristate 13acetate, a potent protein kinase C activator. The involvement of the-231 AP-1 site in phorbol 12myristate 13-acetate stimulation was demonstrated. Moreover, evidence for in vitro and in vivo binding of the-231 AP-1 site to JudFos dimers was obtained using mobility gel shift assays and co-transfection of embryonic F9 cells with Jun/Fos expression plasmids, respectively. The presence in S. mansoni nuclear extracts of components with affinity for the AP-1 site suggests conservation of this regulatory pathway in the parasite.

Current Medicinal Chemistry, 2019

Bromodomains recognize and bind acetyl-lysine residues present in histone and non-histone protein... more Bromodomains recognize and bind acetyl-lysine residues present in histone and non-histone proteins in a specific manner. In the last decade they have raised as attractive targets for drug discovery because the miss-regulation of human bromodomains was discovered to be involved in the development of a large spectrum of diseases. However, targeting eukaryotic pathogens bromodomains continues to be almost unexplored. We and others have reported the essentiality of diverse bromodomain- containing proteins in protozoa, offering a new opportunity for the development of antiparasitic drugs, especially for Trypansoma cruzi, the causative agent of Chagas’ disease. Mammalian bromodomains were classified in eight groups based on sequence similarity but parasitic bromodomains are very divergent proteins and are hard to assign them to any of these groups, suggesting that selective inhibitors can be obtained. In this review, we describe the importance of lysine acetylation and bromodomains in T. ...

Protein Expression and Purification, 1993

ACS Infectious Diseases, May 11, 2023

Photosynthesis: from Light to Biosphere, 1995

Experimental Parasitology, 1998

promotion, transformation, and other signal transduction ization of an intracellular receptor for... more promotion, transformation, and other signal transduction ization of an intracellular receptor for activated protein kinase C pathways. Activation of PKCs results in phosphorylation of (RACK) from the mollusc Biomphalaria glabrata, the intermediate specific proteins and their selective activity is dependent on host for Schistosoma mansoni. Experimental Parasitology 88, 194-199. specific subcellular targeting that allows their accessibility A receptor for activated protein kinase C (RACK) was characterized from the mollusc Biomphalaria glabrata, the intermediate host for to selected substrates (Liu 1996). the human parasite Schistosoma mansoni. This protein was shown to PKC isoenzymes are among the first signaling proteins possess structural and functional characteristics of other RACK proteins that have been shown to undergo translocation from the from various cells and organisms. Its ability to bind mammalian PKCs cytosol to the particulate fraction upon activation. Translocaalso confirmed the conservation of PKC and RACK interactive domains throughout evolution. Results of immunolocalization indicated the pres-tion of PKCs was first thought to reflect a direct binding of ence of Bg RACK in the cytoplasm of mollusc hemocytes and B. the enzyme to membrane lipids but further data indicated glabrata embryonic (Bge) cells with a more intense staining around that proteins could also anchor activated PKCs at the site of the nucleus. These results are in agreement with the association of translocation (Newton 1995). Many of these PKC-targeting RACK proteins with cytoskeletal elements.

En 1940 A. Einstein advirtió que en el futuro “solamente serán exitosos los pueblos que entiendan... more En 1940 A. Einstein advirtió que en el futuro “solamente serán exitosos los pueblos que entiendan cómo generar conocimientos y cómo protegerlos; cómo buscar a los jóvenes que tengan la capacidad de hacerlo y asegurarse de que se queden en el país. Las otras naciones se quedarán con litorales hermosos, con minas, con una historia espléndida; pero probablemente no se queden ni con las mismas banderas ni fronteras. Y mucho menos con capacidad económica”. Ante esta problemática, en nuestro país hubo diferentes respuestas con mayor o menor grado de formalidad, institucionalización e impactos. Una de ellas en 2007 fue el Programa de Recursos Humanos, con dos componentes: Proyectos de Investigación y Desarrollo para la Radicación de Investigadores (PIDRI) y Proyectos de Formación de Doctores en Áreas Tecnológicas Prioritarias (PFDT). La Universidad Nacional de Rosario presentó un Proyecto que incluyó tres de sus Facultades. El objetivo de este trabajo fue analizar el impacto de los PIDRI c...

*IC50 was calculated after 72 hs culture.ND: n... more *IC50 was calculated after 72 hs culture.ND: not determined.IC50<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0003725#t001fn001" target="_blank">*</a> values of sirtuin inhibitors on T. cruzi Dm28c epimastigotes.</p

Current Medicinal Chemistry, 2021

: The number of acetylated proteins identified from bacteria to mammals has grown exponentially i... more : The number of acetylated proteins identified from bacteria to mammals has grown exponentially in the last ten years and it is now accepted that acetylation is a key component in most eukaryotic signaling pathways, as important as phosphorylation. The enzymes involved in this process are well described in mammals; acetyltransferases and deacetylases are found inside and outside the nuclear compartment and have different regulatory functions. In trypanosomatids several of these enzymes have been described and are postulated to be novel antiparasitic targets for the rational design of drugs. In this review article we present an update of the most important known acetylated proteins in trypanosomatids analyzing the acetylomes available. Also, we summarize the information available regarding acetyltransferases and deacetylases in trypanosomes and their potential use as chemotherapeutic targets.

Journal of Visualized Experiments, 2021