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1.
PLoS One ; 19(5): e0292152, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38753846

RESUMEN

In the protozoan parasite Leishmania, most genes encoding for ribosomal proteins (RPs) are present as two or more copies in the genome. However, their untranslated regions (UTRs) are predominantly divergent and might be associated with a distinct regulation of the expression of paralogous genes. Herein, we investigated the expression profiles of two RPs (S16 and L13a) encoded by duplicated genes in Leishmania major. The genes encoding for the S16 protein possess identical coding sequences (CDSs) and divergent UTRs, whereas the CDSs of L13a diverge by two amino acids and by their UTRs. Using CRISPR/Cas9 genome editing, we generated knockout (Δ) and endogenously tagged transfectants for each paralog of L13a and S16 genes. Combining tagged and Δ cell lines we found evidence of differential expression of both RPS16 and RPL13a isoforms throughout parasite development, with one isoform consistently more abundant than its respective copy. In addition, compensatory expression was observed for each paralog upon deletion of the corresponding isoform, suggesting functional conservation between these proteins. This differential expression pattern relates to post-translational processes, given compensation occurs at the level of the protein, with no alterations detected at transcript level. Ribosomal profiles for RPL13a indicate a standard behavior for these paralogues suggestive of interaction with heavy RNA-protein complexes, as already reported for other RPs in trypanosomatids. We identified paralog-specific bound to their 3'UTRs which may be influential in regulating paralog expression. In support, we identified conserved cis-elements within the 3'UTRs of RPS16 and RPL13a; cis-elements exclusive to the UTR of the more abundant paralog or to the less abundant ones were identified.


Asunto(s)
Leishmania major , Proteínas Protozoarias , Proteínas Ribosómicas , Proteínas Ribosómicas/genética , Proteínas Ribosómicas/metabolismo , Leishmania major/genética , Proteínas Protozoarias/genética , Proteínas Protozoarias/metabolismo , Sistemas CRISPR-Cas , Regulación de la Expresión Génica , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo
2.
Microbiol Resour Announc ; 13(6): e0116823, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38651916

RESUMEN

We sequenced the genome of a hirame novirhabdovirus isolate recovered from a white bass (Morone chrysops). Hirame novirhabdoviruses are in the genus Novirhabdovirus, along with infectious hematopoietic necrosis virus and viral hemorrhagic septicemia virus. This detection highlights that the full host range of rhabdoviruses in fish is not fully understood.

3.
Acta Trop ; 244: 106959, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37257676

RESUMEN

Arginine methylation is catalysed by Protein Arginine Methyltransferases (PRMTs) and can affect how a target protein functions and how it interacts with other macromolecules, which in turn impacts on cell metabolism and gene expression control. Leishmania parasites express five different PRMTs, and although the presence of each individual PRMT is not essential per se, the imbalanced activity of these PRMTs can impact the virulence of Leishmania parasites in vitro and in vivo. Here we created a Leishmania major cell line overexpressing PRMT6 and show that similar to what was observed for the T. brucei homologous enzyme, L. major PRMT6 probably has a narrow substrate range. However, its overexpression notably impairs the infection in mice, with a mild reduction in the number of viable parasites in the lymph nodes. Our results indicate that arginine methylation by LmjPRMT6 plays a significant role in the adaptation of the parasite to the environment found in the mammalian host.


Asunto(s)
Leishmania major , Parásitos , Ratones , Animales , Proteína-Arginina N-Metiltransferasas/química , Proteína-Arginina N-Metiltransferasas/genética , Proteína-Arginina N-Metiltransferasas/metabolismo , Parásitos/metabolismo , Metilación , Arginina/metabolismo , Mamíferos
4.
Plast Reconstr Surg Glob Open ; 11(4): e4924, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37063507

RESUMEN

Radiofrequency is frequently used for skin rejuvenation, localized fat elimination and cellulite treatment. It prompts the expression of thermal shock proteins that lead to dermal thickening as a result of collagen synthesis. The authors report a histological and clinical analysis of the arm subdermal changes before and after bipolar radiofrequency treatment plus liposuction to determine their benefits for arm contouring. Methods: Inclusion criteria included patients with stage 1, 2a, and 2b brachial ptosis (Duncan classification) and upper limb fat deposits who were considered candidates for third-generation ultrasound-assisted liposculpture plus radiofrequency-assisted lipolysis/skin tightening. Arm subdermal tissue samples (5 mm³) were analyzed before and after the intervention. We used 10% formaldehyde for tissue fixation and stained each sample with hematoxylin/eosin, Masson trichrome, and antibody markers against the cell cycle Ki-67 protein. Results: We analyzed a total of 12 biopsies from six patients who meet the inclusion/exclusion criteria. Histological findings with hematoxylin/eosin revealed hyperplastic and metaplastic changes with focal distribution within the papillary and reticular dermis. Masson trichrome staining showed an increase of the characteristic basophilia of thin type-I and type-III collagen fibers. In contrast, molecular analysis reported an increase in fibroblast activity mediated by the activation of the heat shock protein HSP47. Conclusion: Radiofrequency may be a great alternative to improve skin retraction in patients with mild to moderate brachial dermatochalasis through the activation of HSP47 heat shock protein and the production of type-I and type-III collagen.

5.
Front Cell Infect Microbiol ; 13: 1102462, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36779182

RESUMEN

Leishmania are kinetoplastid pathogens that cause leishmaniasis, a debilitating and potentially life-threatening infection if untreated. Unusually, Leishmania regulate their gene expression largely post-transcriptionally due to the arrangement of their coding genes into polycistronic transcription units that may contain 100s of functionally unrelated genes. Yet, Leishmania are capable of rapid and responsive changes in gene expression to challenging environments, often instead correlating with dynamic changes in their genome composition, ranging from chromosome and gene copy number variations to the generation of extrachromosomal DNA and the accumulation of point mutations. Typically, such events indicate genome instability in other eukaryotes, coinciding with genetic abnormalities, but for Leishmania, exploiting these products of genome instability can provide selectable substrates to catalyse necessary gene expression changes by modifying gene copy number. Unorthodox DNA replication, DNA repair, replication stress factors and DNA repeats are recognised in Leishmania as contributors to this intrinsic instability, but how Leishmania regulate genome plasticity to enhance fitness whilst limiting toxic under- or over-expression of co-amplified and co-transcribed genes is unclear. Herein, we focus on fresh, and detailed insights that improve our understanding of genome plasticity in Leishmania. Furthermore, we discuss emerging models and factors that potentially circumvent regulatory issues arising from polycistronic transcription. Lastly, we highlight key gaps in our understanding of Leishmania genome plasticity and discuss future studies to define, in higher resolution, these complex regulatory interactions.


Asunto(s)
Leishmania , Humanos , Leishmania/genética , Variaciones en el Número de Copia de ADN , Plásticos , Inestabilidad Genómica , Expresión Génica
6.
IJID Reg ; 3: 101-105, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35755473

RESUMEN

Background: Few hematopoietic stem cell transplantations (HSCT) are performed in lower-middle income countries. Only four institutions in the Philippines are able to perform transplants. This study describes the experience of a newly established program. Methods: The charts of all adult patients who underwent HSCT at The Medical City from May 1, 2016 to December 31, 2019 were reviewed retrospectively. Results: A total of 33 patients were included in the cohort, of whom 31 (93.9%) underwent autologous HSCT and only two (6.1%) underwent allogeneic HSCT. Most were female (21/33, 63%), and median age was 51 years (range 21-67 years). The primary indication for transplantation was multiple myeloma (n = 21), followed by diffuse B-cell lymphoma (n = 6). Fifteen of the 33 patients had a history of treated tuberculosis (TB) disease (n = 4) or latent TB infection (n = 11). The median time for neutrophil recovery was 7.4 days (range 4-13 days). Transplant complications included neutropenic fever (n = 33, 100%) and mucositis (n = 14, 42.4%). Bacterial infection was documented in 12 (36.4%) patients, with nine (24.2%) developing a bacterial blood stream infection of which seven were related to a central line. The overall mortality rate was at 6.1% (2/33) in the first 30 days post-transplant, with no additional mortality in the succeeding days until day 100. Conclusions: This cohort with mostly autologous HSCT had favorable outcomes in the first 100 days. Rates of bacterial infection were high in the early post-transplant period. Latent TB infection was common, but no reactivation was observed. Longer-term follow-up of patients is needed to determine late post-transplant complications and outcomes.

7.
ACS Infect Dis ; 8(3): 516-532, 2022 03 11.
Artículo en Inglés | MEDLINE | ID: mdl-35226477

RESUMEN

In trypanosomatids, regulation of gene expression occurs mainly at the posttranscriptional level, and RNA-binding proteins (RBPs) are key players in determining the fates of transcripts. RBPs are targets of protein arginine methyltransferases (PRMTs), which posttranslationally regulate the RNA-binding capacity and other RBP interactions by transferring methyl groups to arginine residues (R-methylation). Herein, we functionally characterized the five predicted PRMTs in Leishmania braziliensis by gene knockout and endogenous protein HA tagging using CRISPR/Cas9 gene editing. We report that R-methylation profiles vary among Leishmania species and across L. braziliensis lifecycle stages, with the peak PRMT expression occurring in promastigotes. A list of PRMT-interacting proteins was obtained in a single coimmunoprecipitation assay using HA-tagged PRMTs, suggesting a network of putative targets of PRMTs and cooperation between the R-methylation writers. Knockout of each L. braziliensis PRMT led to significant changes in global arginine methylation patterns without affecting cell viability. Deletion of either PRMT1 or PRMT3 disrupted most type I PRMT activity, resulting in a global increase in monomethyl arginine levels. Finally, we demonstrate that L. braziliensis PRMT1 and PRMT5 are required for efficient macrophage infection in vitro, and for axenic amastigote proliferation. The results indicate that R-methylation is modulated across lifecycle stages in L. braziliensis and show possible functional overlap and cooperation among the different PRMTs in targeting proteins. Overall, our data suggest important regulatory roles of these proteins throughout the L. braziliensis life cycle, showing that arginine methylation is important for parasite-host cell interactions.


Asunto(s)
Leishmania braziliensis , Proteína-Arginina N-Metiltransferasas , Arginina/metabolismo , Leishmania braziliensis/genética , Macrófagos/metabolismo , Metilación , Proteína-Arginina N-Metiltransferasas/química , Proteína-Arginina N-Metiltransferasas/genética , Proteína-Arginina N-Metiltransferasas/metabolismo
8.
Front Cell Infect Microbiol ; 11: 772311, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34858879

RESUMEN

Until 2015, loss-of-function studies to elucidate protein function in Leishmania relied on gene disruption through homologous recombination. Then, the CRISPR/Cas9 revolution reached these protozoan parasites allowing efficient genome editing with one round of transfection. In addition, the development of LeishGEdit, a PCR-based toolkit for generating knockouts and tagged lines using CRISPR/Cas9, allowed a more straightforward and effective genome editing. In this system, the plasmid pTB007 is delivered to Leishmania for episomal expression or integration in the ß-tubulin locus and for the stable expression of T7 RNA polymerase and Cas9. In South America, and especially in Brazil, Leishmania (Viannia) braziliensis is the most frequent etiological agent of tegumentary leishmaniasis. The L. braziliensis ß-tubulin locus presents significant sequence divergence in comparison with Leishmania major, which precludes the efficient integration of pTB007 and the stable expression of Cas9. To overcome this limitation, the L. major ß-tubulin sequences, present in the pTB007, were replaced by a Leishmania (Viannia) ß-tubulin conserved sequence generating the pTB007_Viannia plasmid. This modification allowed the successful integration of the pTB007_Viannia cassette in the L. braziliensis M2903 genome, and in silico predictions suggest that this can also be achieved in other Viannia species. The activity of Cas9 was evaluated by knocking out the flagellar protein PF16, which caused a phenotype of immobility in these transfectants. Endogenous PF16 was also successfully tagged with mNeonGreen, and an in-locus complementation strategy was employed to return a C-terminally tagged copy of the PF16 gene to the original locus, which resulted in the recovery of swimming capacity. The modified plasmid pTB007_Viannia allowed the integration and stable expression of both T7 RNA polymerase and Cas9 in L. braziliensis and provided an important tool for the study of the biology of this parasite.


Asunto(s)
Leishmania braziliensis , Leishmania major , Sistemas CRISPR-Cas , ARN Polimerasas Dirigidas por ADN , Edición Génica , Leishmania braziliensis/genética , Proteínas Virales
9.
Medicine (Baltimore) ; 100(51): e28315, 2021 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-34941127

RESUMEN

ABSTRACT: Circulating HIV subtypes in the Philippines have increasingly diversified, potentially affecting treatment. We monitored outcomes of a treatment-naïve cohort and their virus subtype prevalence.Retrospective/prospective study cohort.HIV-I-REACT clinic patients co-enrolled in the Virology Quality Assurance Program (RUSH-VQA) from 7/2017-6/2019 were included. Relevant demographic and laboratory information were collected. The ViroSeq HIV-1 Genotyping System v.3 and HIV-1 Integrase Genotyping Kit identified protease-reverse transcriptase and integrase drug resistance mutations (DRM). Sequence subtyping followed using the Stanford University Drug Resistance Database and the REGA HIV-1 Subtyping Tool v.3. The jpHMM HIV-1 Tool and REGA HIV-1 Subtyping Tool provided additional subtype analysis of this cohort's 5'LTR-VIF regions after Sanger sequencing. One-year outcomes included virologic suppression, mortality, and follow-up.86/88 patients were males. Median age was 30 (range 19-65) years; 61/88 were MSM. 15/85 carried baseline DRM. ViroSeq-generated sequences included subtypes CRF01_AE (66/85), B (14/85), and newer recombinants (4/85). Extensive sequencing (n = 71) of the 5'-LTR-GAG-Pol genes showed CRF01_AE (n = 50), subtype B (n = 7), and other recombinants (n = 13). Bootstrap analysis identified 7 pairs of highly related strains. Discordant DRM appeared in 2/7 pairs, where 1/2 strains displayed DRM. After 1 year, 87 individuals were alive, with 19 lost to care. Viral load (VL) was repeated for only 31/77 (40.2%). Follow-up CD4 testing for 39/77 (50.6%) showed an increase to a median of 327 cells/mm3.Our cohort currently carries subtype CRF01_AE (∼68%-70%), followed by subtype B and CRF01_AE/B recombinants. Outcomes were favorable, regardless of subtype after 1 year on cART.


Asunto(s)
Infecciones por VIH/epidemiología , VIH-1/genética , Adulto , Anciano , Femenino , Genotipo , Infecciones por VIH/tratamiento farmacológico , Seropositividad para VIH , VIH-1/aislamiento & purificación , Humanos , Masculino , Persona de Mediana Edad , Filipinas/epidemiología , Filogenia , Reacción en Cadena de la Polimerasa , Estudios Prospectivos , Estudios Retrospectivos , Secuenciación Completa del Genoma , Adulto Joven
10.
Front Mol Biosci ; 8: 692668, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34179098

RESUMEN

A large number of eukaryotic proteins are processed by single or combinatorial post-translational covalent modifications that may alter their activity, interactions and fate. The set of modifications of each protein may be considered a "regulatory code". Among the PTMs, arginine methylation, catalyzed by protein arginine methyltransferases (PRMTs), can affect how a protein interacts with other macromolecules such as nucleic acids or other proteins. In fact, many RNA-binding (RBPs) proteins are targets of PRMTs. The methylation status of RBPs may affect the expression of their bound RNAs and impact a diverse range of physiological and pathological cellular processes. Unlike most eukaryotes, Kinetoplastids have overwhelmingly intronless genes that are arranged within polycistronic units from which mature mRNAs are generated by trans-splicing. Gene expression in these organisms is thus highly dependent on post-transcriptional control, and therefore on the action of RBPs. These genetic features make trypanosomatids excellent models for the study of post-transcriptional regulation of gene expression. The roles of PRMTs in controlling the activity of RBPs in pathogenic kinetoplastids have now been studied for close to 2 decades with important advances achieved in recent years. These include the finding that about 10% of the Trypanosoma brucei proteome carries arginine methylation and that arginine methylation controls Leishmania:host interaction. Herein, we review how trypanosomatid PRMTs regulate the activity of RBPs, including by modulating interactions with RNA and/or protein complex formation, and discuss how this impacts cellular and biological processes. We further highlight unique structural features of trypanosomatid PRMTs and how it contributes to their singular functionality.

12.
Biology (Basel) ; 10(3)2021 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-33808600

RESUMEN

The increased antibiotics usage in biomedical and agricultural settings has been well documented. Antibiotics have now been shown to exert effects outside their purposive use, including effects on physiological and developmental processes. We explored the effect of various antibiotics on intestinal regeneration in the sea cucumber Holothuria glaberrima. For this, holothurians were eviscerated and left to regenerate for 10 days in seawater with different penicillin/streptomycin-based cocktails (100 µg/mL PS) including: 100 µg/mL kanamycin (KPS), 5 µg/mL vancomycin (VPS), and 4 µg/mL (E4PS) or 20 µg/mL (E20PS) erythromycin. Immunohistological and histochemical analyses were performed to analyze regenerative processes, including rudiment size, extracellular matrix (ECM) remodeling, cell proliferation, and muscle dedifferentiation. A reduction in muscle dedifferentiation was observed in all antibiotic-treated animals. ECM remodeling was decreased by VPS, E4PS, and E20PS treatments. In addition, organisms subjected to E20PS displayed a significant reduction in the size of their regenerating rudiments while VPS exposure altered cell proliferation. MTT assays were used to discard the possibility that the antibiotics directly affect holothurian metabolic activity while bacterial cultures were used to test antibiotic effects on holothurian enteric microbiota. Our results demonstrate a negative effect on intestinal regeneration and strongly suggest that these effects are due to alterations in the microbial community.

13.
PLoS Negl Trop Dis ; 15(3): e0009230, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33651805

RESUMEN

Leishmania major is the main causative agent of cutaneous leishmaniasis in the Old World. In Leishmania parasites, the lack of transcriptional control is mostly compensated by post-transcriptional mechanisms. Methylation of arginine is a conserved post-translational modification executed by Protein Arginine Methyltransferase (PRMTs). The genome from L. major encodes five PRMT homologs, including the cytosolic protein associated with several RNA-binding proteins, LmjPRMT7. It has been previously reported that LmjPRMT7 could impact parasite infectivity. In addition, a more recent work has clearly shown the importance of LmjPRMT7 in RNA-binding capacity and protein stability of methylation targets, demonstrating the role of this enzyme as an important epigenetic regulator of mRNA metabolism. In this study, we unveil the impact of PRMT7-mediated methylation on parasite development and virulence. Our data reveals that higher levels of LmjPRMT7 can impair parasite pathogenicity, and that deletion of this enzyme rescues the pathogenic phenotype of an attenuated strain of L. major. Interestingly, lesion formation caused by LmjPRMT7 knockout parasites is associated with an exacerbated inflammatory reaction in the tissue correlated with an excessive neutrophil recruitment. Moreover, the absence of LmjPRMT7 also impairs parasite development within the sand fly vector Phlebotomus duboscqi. Finally, a transcriptome analysis shed light onto possible genes affected by depletion of this enzyme. Taken together, this study highlights how post-transcriptional regulation can affect different aspects of the parasite biology.


Asunto(s)
Leishmania major/enzimología , Leishmaniasis Cutánea/patología , Neutrófilos/fisiología , Proteína Metiltransferasas/metabolismo , Proteínas Protozoarias/metabolismo , Animales , Eliminación de Gen , Regulación Enzimológica de la Expresión Génica , Leishmania major/genética , Leishmania major/metabolismo , Leishmaniasis Cutánea/parasitología , Ratones , Proteína Metiltransferasas/genética
14.
Mem Inst Oswaldo Cruz ; 116: e200634, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33787768

RESUMEN

The availability of Trypanosomatid genomic data in public databases has opened myriad experimental possibilities that have contributed to a more comprehensive understanding of the biology of these parasites and their interactions with hosts. In this review, after brief remarks on the history of the Trypanosoma cruzi and Leishmania genome initiatives, we present an overview of the relevant contributions of genomics, transcriptomics and functional genomics, discussing the primary obstacles, challenges, relevant achievements and future perspectives of these technologies.


Asunto(s)
Genoma de Protozoos/genética , Leishmania/genética , Trypanosoma cruzi/genética , Biología Computacional , Genómica
15.
Clin Transplant ; 35(2): e14169, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33247978

RESUMEN

Transplant recipients are vulnerable to infections, including COVID-19, given their comorbidities and chronic immunosuppression. In this study, all hospitalized renal transplant recipients (RTR) with a positive nasal swab for Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV2) seen consecutively between 03/01/2020 and 05/01/2020 at the Detroit Medical Center were included. Data on demographics, clinical presentation, laboratory findings, management, and outcomes were collected. Twenty-five patients were included, all African American (AA) and deceased-donor transplant recipients. The most common presenting symptom was dyspnea, followed by fever, cough and diarrhea. Multifocal opacities on initial chest x-ray were seen in 52% patients and 44% of patients had a presenting oxygen saturation of less than or equal to 94%. Four patients (16%) required transfer to the intensive care unit, one required intubation and one expired. COVID-19-infected RTR in this cohort had low mortality of 4% (n = 1). Despite multiple comorbidities and chronic immunosuppression, our cohort of African American RTR had favorable outcomes compared to other reports on COVID-19 in RTR.


Asunto(s)
Negro o Afroamericano , COVID-19/etnología , Terapia de Inmunosupresión/métodos , Unidades de Cuidados Intensivos , Trasplante de Riñón , Fallo Hepático/etnología , Receptores de Trasplantes , Anciano , Comorbilidad , Femenino , Humanos , Fallo Hepático/cirugía , Masculino , Michigan/epidemiología , Persona de Mediana Edad , ARN Viral/análisis , SARS-CoV-2/genética
16.
Nucleic Acids Res ; 48(10): 5511-5526, 2020 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-32365184

RESUMEN

RNA binding proteins (RBPs) are the primary gene regulators in kinetoplastids as transcriptional control is nearly absent, making Leishmania an exceptional model for investigating methylation of non-histone substrates. Arginine methylation is an evolutionarily conserved protein modification catalyzed by Protein aRginine Methyl Transferases (PRMTs). The chromatin modifier PRMT7 is the only Type III PRMT found in higher eukaryotes and a restricted number of unicellular eukaryotes. In Leishmania major, PRMT7 is a cytoplasmic protein implicit in pathogenesis with unknown substrates. Using comparative methyl-SILAC proteomics for the first time in protozoa, we identified 40 putative targets, including 17 RBPs hypomethylated upon PRMT7 knockout. PRMT7 can modify Alba3 and RBP16 trans-regulators (mammalian RPP25 and YBX2 homologs, respectively) as direct substrates in vitro. The absence of PRMT7 levels in vivo selectively reduces Alba3 mRNA-binding capacity to specific target transcripts and can impact the relative stability of RBP16 in the cytoplasm. RNA immunoprecipitation analyses demonstrate PRMT7-dependent methylation promotes Alba3 association with select target transcripts and thus indirectly stabilizes mRNA of a known virulence factor, δ-amastin surface antigen. These results highlight a novel role for PRMT7-mediated arginine methylation of RBP substrates, suggesting a regulatory pathway controlling gene expression and virulence in Leishmania. This work introduces Leishmania PRMTs as epigenetic regulators of mRNA metabolism with mechanistic insight into the functional manipulation of RBPs by methylation.


Asunto(s)
Leishmania major/enzimología , Proteína-Arginina N-Metiltransferasas/metabolismo , Proteínas Protozoarias/metabolismo , Proteínas de Unión al ARN/metabolismo , Regulación de la Expresión Génica , Leishmania major/genética , Metilación , Estabilidad Proteica
17.
PLoS Negl Trop Dis ; 14(5): e0008262, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32469928

RESUMEN

Adhesion of T. cruzi trypomastigotes to components of the extracellular matrix (ECM) is an important step in mammalian host cell invasion. We have recently described a significant increase in the tyrosine nitration levels of histones H2A and H4 when trypomastigotes are incubated with components of the ECM. In this work, we used chromatin immunoprecipitation (ChIP) with an anti-nitrotyrosine antibody followed by mass spectrometry to identify nitrated DNA binding proteins in T. cruzi and to detect alterations in nitration levels induced upon parasite incubation with the ECM. Histone H1, H2B, H2A and H3 were detected among the 9 most abundant nitrated DNA binding proteins using this proteomic approach. One nitrated tyrosine residue (Y29) was identified in Histone H2B in the MS/MS spectrum. In addition, we observed a significant increase in the nitration levels of histones H1, H2B, H2A and H4 upon parasite incubation with ECM. Finally, we used ChIP-Seq to map global changes in the DNA binding profile of nitrated proteins. We observed a significant change in the binding pattern of nitrated proteins to DNA after parasite incubation with ECM. This work provides the first global profile of nitrated DNA binding proteins in T. cruzi and additional evidence for modification in the nitration profile of histones upon parasite incubation with ECM. Our data also indicate that the parasite interaction with the ECM induces alterations in chromatin structure, possibly affecting nuclear functions.


Asunto(s)
Matriz Extracelular/parasitología , Histonas/análisis , Procesamiento Proteico-Postraduccional , Proteínas Protozoarias/análisis , Trypanosoma cruzi/química , Trypanosoma cruzi/crecimiento & desarrollo , Inmunoprecipitación de Cromatina , Matriz Extracelular/metabolismo , Histonas/metabolismo , Espectrometría de Masas , Nitrosación , Proteómica , Proteínas Protozoarias/metabolismo , Tirosina/análogos & derivados , Tirosina/inmunología
18.
Parasit Vectors ; 13(1): 9, 2020 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-31915065

RESUMEN

BACKGROUND: Prostaglandins (PG) are lipid mediators derived from arachidonic acid metabolism. They are involved in cellular processes such as inflammation and tissue homeostasis. PG production is not restricted to multicellular organisms. Trypanosomatids also synthesize several metabolites of arachidonic acid. Nevertheless, their biological role in these early-branching parasites and their role in host-parasite interaction are not well elucidated. Prostaglandin F2α synthase (PGF2S) has been observed in the Leishmania braziliensis secreted proteome and in L. donovani extracellular vesicles. Furthermore, we previously reported a positive correlation between L. braziliensis PGF2S (LbrPGF2S) expression and pathogenicity in mice. METHODS: LbrPGF2S gene expression and PGF2α synthesis in promastigotes were detected and quantified by western blotting and EIA assay kit, respectively. To investigate LbrPGF2S localization in amastigotes during bone marrow-derived macrophage infection, parasites expressing mCherry-LbrPGF2S were generated and followed by time-lapse imaging for 48 h post-infection. PGF2S homolog sequences from Leishmania and humans were analyzed in silico using ClustalW on Geneious v6 and EMBOSS Needle. RESULTS: Leishmania braziliensis promastigotes synthesize prostaglandin F2α in the presence of arachidonic acid, with peak production in the stationary growth phase under heat stress. LbrPGF2S is a cytoplasmic protein enriched in the secretory site of the parasite cell body, the flagellar pocket. It is an enzyme constitutively expressed throughout promastigote development, but overexpression of LbrPGF2S leads to an increase of infectivity in vitro. The data suggest that LbrPGF2S may be released from intracellular amastigotes into the cytoplasm of bone marrow-derived macrophages over a 48-hour infection period, using time-lapse microscopy and mCherry-PGF2S (mChPGF2S)-expressing parasites. CONCLUSIONS: LbrPGF2S, a parasite-derived protein, is targeted to the host cell cytoplasm. The putative transfer of this enzyme, involved in pro-inflammatory lipid mediator synthesis, to the host cell suggests a potential role in host-parasite interaction and may partially explain the increased pathogenicity associated with overexpression of LbrPGF2S in L. braziliensis. Our data provide valuable insights to help understand the importance of parasite-derived lipid mediators in pathogenesis.


Asunto(s)
Leishmania braziliensis/enzimología , Leishmaniasis Cutánea/parasitología , Prostaglandina-Endoperóxido Sintasas/metabolismo , Proteínas Protozoarias/metabolismo , Animales , Interacciones Huésped-Parásitos , Humanos , Leishmania braziliensis/genética , Leishmania braziliensis/crecimiento & desarrollo , Leishmania braziliensis/metabolismo , Macrófagos/parasitología , Ratones , Ratones Endogámicos BALB C , Prostaglandina-Endoperóxido Sintasas/genética , Prostaglandinas/biosíntesis , Proteínas Protozoarias/genética
20.
Nat Commun ; 10(1): 5273, 2019 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-31754185

RESUMEN

Leishmania RNA virus (LRV) is an important virulence factor associated with the development of mucocutaneous Leishmaniasis, a severe form of the disease. LRV-mediated disease exacerbation relies on TLR3 activation, but downstream mechanisms remain largely unexplored. Here, we combine human and mouse data to demonstrate that LRV triggers TLR3 and TRIF to induce type I IFN production, which induces autophagy. This process results in ATG5-mediated degradation of NLRP3 and ASC, thereby limiting NLRP3 inflammasome activation in macrophages. Consistent with the known restricting role of NLRP3 for Leishmania replication, the signaling pathway triggered by LRV results in increased parasite survival and disease progression. In support of this data, we find that lesions in patients infected with LRV+ Leishmania are associated with reduced inflammasome activation and the development of mucocutaneous disease. Our findings reveal the mechanisms triggered by LRV that contribute to the development of the debilitating mucocutaneous form of Leishmaniasis.


Asunto(s)
Inmunidad Innata/inmunología , Inflamasomas/inmunología , Leishmania/inmunología , Leishmaniasis Mucocutánea/inmunología , Proteína con Dominio Pirina 3 de la Familia NLR/inmunología , Virus ARN/inmunología , Receptor Toll-Like 3/inmunología , Animales , Autofagia/inmunología , Humanos , Interleucina-1beta/inmunología , Interleucina-1beta/metabolismo , Leishmania/fisiología , Leishmania/virología , Leishmaniasis Mucocutánea/parasitología , Leishmaniasis Mucocutánea/virología , Macrófagos/inmunología , Ratones , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Virus ARN/fisiología , Transducción de Señal/inmunología , Receptor Toll-Like 3/metabolismo
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