Publications by authors named "Carlos M Restrepo"

19 Publications

  • Page 1 of 1

Gene expression patterns associated with Leishmania panamensis infection in macrophages from BALB/c and C57BL/6 mice.

PLoS Negl Trop Dis 2021 Feb 22;15(2):e0009225. Epub 2021 Feb 22.

Centro de Biología Celular y Molecular de Enfermedades, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Panama City, Panama, Republic of Panama.

Leishmania parasites can trigger different host immune responses that result in varying levels of disease severity. The C57BL/6 and BALB/c mouse strains are among the host models commonly used for characterizing the immunopathogenesis of Leishmania species and the possible antileishmanial effect of novel drug candidates. C57BL/6 mice tend to be resistant to Leishmania infections, whereas BALB/c mice display a susceptible phenotype. Studying species-specific interactions between Leishmania parasites and different host systems is a key step to characterize and validate these models for in vivo studies. Here, we use RNA-Seq and differential expression analysis to characterize the transcriptomic profiles of C57BL/6 and BALB/c peritoneal-derived macrophages in response to Leishmania panamensis infection. We observed differences between BALB/c and C57BL/6 macrophages regarding pathways associated with lysosomal degradation, arginine metabolism and the regulation of cell cycle. We also observed differences in the expression of chemokine and cytokine genes associated with regulation of immune responses. In conclusion, infection with L. panamensis induced an inflammatory gene expression pattern in C57BL/6 macrophages that is more consistently associated with a classic macrophage M1 activation, whereas in BALB/c macrophages a gene expression pattern consistent with an intermediate inflammatory response was observed.
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http://dx.doi.org/10.1371/journal.pntd.0009225DOI Listing
February 2021

HLA allele and haplotype frequencies in the Panamanian population.

Hum Immunol 2021 Jan 7;82(1):5-7. Epub 2020 Dec 7.

Laboratorio Nacional de Trasplante, Complejo Hospitalario Dr. Arnulfo Arias Madrid (CHDrAAM), Caja de Seguro Social, Panama, Panama. Electronic address:

In this study, we report for the first time HLA allele and haplotype frequencies in the modern Panamanian population at a two-field (four digits) resolution level. Reported frequencies were calculated from genotype data for the HLA-A, -B, -C, -DPB1, -DQB1 and -DRB1 loci of 462 healthy unrelated Panamanian adults of Hispanic ethnicity. In addition to providing new insights on the allelic structure of the Panamanian population and its origin, these data are critical for better planning of healthcare strategies in the country and for future research exploring the association with certain chronic and infectious diseases.
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http://dx.doi.org/10.1016/j.humimm.2020.11.006DOI Listing
January 2021

Antileishmanial activity of a new chloroquine analog in an animal model of Leishmania panamensis infection.

Int J Parasitol Drugs Drug Resist 2020 12 15;14:56-61. Epub 2020 Aug 15.

Centro de Biología Celular y Molecular de Enfermedades, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Edificio 208, Ciudad del Saber, Apartado 0843-01103, Panama, 0801, Panama. Electronic address:

Leishmania panamensis is a relevant causative agent of tegumentary leishmaniasis in several Latin American countries. Available antileishmanial drugs have several limitations including relatively high toxicity, difficult administration, high production costs and the emergence of resistance in circulating strains. Therefore, the identification of new molecules as potential therapeutics for leishmaniasis is of great relevance. Here, we developed a murine model of L. panamensis infection and evaluated the effect of a new compound in vivo. After treatment of animals with the compound, we observed a significant reduction of inflammation and parasite load at the inoculation site, in a dose-dependent manner. We observed a reduction in IL-10 production by popliteal lymph nodes cells of infected mice. These results pave the way for future evaluation of this compound as a potential antileishmanial drug or as a suitable scaffold for lead optimization strategies.
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http://dx.doi.org/10.1016/j.ijpddr.2020.08.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7502791PMC
December 2020

Genomes: How Genomic Information has been Used to Deal with Past Outbreaks and the COVID-19 Pandemic.

Int J Mol Sci 2020 Jun 26;21(12). Epub 2020 Jun 26.

Centro de Biología Celular y Molecular de Enfermedades, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Panama City 0801, Panama.

In the 21st century, three highly pathogenic betacoronaviruses have emerged, with an alarming rate of human morbidity and case fatality. Genomic information has been widely used to understand the pathogenesis, animal origin and mode of transmission of coronaviruses in the aftermath of the 2002-2003 severe acute respiratory syndrome (SARS) and 2012 Middle East respiratory syndrome (MERS) outbreaks. Furthermore, genome sequencing and bioinformatic analysis have had an unprecedented relevance in the battle against the 2019-2020 coronavirus disease 2019 (COVID-19) pandemic, the newest and most devastating outbreak caused by a coronavirus in the history of mankind. Here, we review how genomic information has been used to tackle outbreaks caused by emerging, highly pathogenic, betacoronavirus strains, emphasizing on SARS-CoV, MERS-CoV and SARS-CoV-2. We focus on shared genomic features of the betacoronaviruses and the application of genomic information to phylogenetic analysis, molecular epidemiology and the design of diagnostic systems, potential drugs and vaccine candidates.
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http://dx.doi.org/10.3390/ijms21124546DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7352669PMC
June 2020

Frequency of and Risk Factors Associated with the Infection in Stray Dogs and Cats of Panama.

Microorganisms 2020 Jun 19;8(6). Epub 2020 Jun 19.

Centro de Biología Celular y Molecular de Enfermedades, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT-AIP), Panamá 0801, Panama.

Stray animals such as dogs and cats have an important role in maintaining the transmission cycles and dissemination of . Therefore, the objective of this study was to evaluate the frequency of in stray dogs and cats in six different regions of Panama and determine risk factors associated with the dynamics of infection in each of the studied regions. Data were obtained using serological tests for the detection of anti- IgG and IgM antibodies. The results of this study revealed an overall infection frequency of 23.73%. The infection frequencies found in dog and cat populations were 25.70% and 21.93% respectively, showing no statistically significant difference. Risk factor correlations suggested different infection dynamics depending on the region analyzed. The San Miguelito, North and West regions were more associated with positive cases in dogs with an age range greater than 13 months. Conversely, the Metro, Central and East regions were more associated with negative cases in cats with age ranging between 0 and 5 months. Infection of the parasite in stray animals can be influenced by intrinsic characteristics of each region, which can potentiate different risk factors associated with the different routes of transmission.
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http://dx.doi.org/10.3390/microorganisms8060927DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7356863PMC
June 2020

Environmental Conditions May Shape the Patterns of Genomic Variations in .

Genes (Basel) 2019 10 24;10(11). Epub 2019 Oct 24.

Centro de Biología Celular y Molecular de Enfermedades, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Panama 0801, Panama.

Due to the absence of transcriptional regulation of gene expression in parasites, it is now well accepted that several forms of genomic variations modulate the levels of critical proteins through changes in gene dosage. We previously observed many of these variations in our reference laboratory strain of (PSC-1 strain), including chromosomes with an increased somy and the presence of a putative linear minichromosome derived from chromosome 34. Here, we compared the previously described genomic variations with those occurring after exposure of this strain to increasing concentrations of trivalent antimony (Sb), as well as those present in two geographically unrelated clinical isolates of . We observed changes in the somy of several chromosomes, amplifications of several chromosomal regions, and copy number variations in gene arrays after exposure to Sb. Occurrence of amplifications potentially beneficial for the Sb-resistant phenotype appears to be associated with the loss of other forms of amplification, such as the linear minichromosome. In contrast, we found no evidence of changes in somy or amplification of relatively large chromosomal regions in the clinical isolates. In these isolates, the predominant amplifications appear to be those that generate genes arrays; however, in many cases, the amplified arrays have a notably higher number of copies than those from the untreated and Sb-treated laboratory samples.
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http://dx.doi.org/10.3390/genes10110838DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6896075PMC
October 2019

Congenital Leptin Deficiency and Leptin Gene Missense Mutation Found in Two Colombian Sisters with Severe Obesity.

Genes (Basel) 2019 05 7;10(5). Epub 2019 May 7.

Facultad de Medicina, Universidad de La Sabana, Chía 53753, Colombia.

Background: Congenital leptin deficiency is a recessive genetic disorder associated with severe early-onset obesity. It is caused by mutations in the leptin () gene, which encodes the protein product leptin. These mutations may cause nonsense-mediated mRNA decay, defective secretion or the phenomenon of biologically inactive leptin, but typically lead to an absence of circulating leptin, resulting in a rare type of monogenic extreme obesity with intense hyperphagia, and serious metabolic abnormalities.

Methods: We present two severely obese sisters from Colombia, members of the same lineal consanguinity. Their serum leptin was measured by MicroELISA. DNA sequencing was performed on MiSeq equipment (Illumina) of a next-generation sequencing (NGS) panel involving genes related to severe obesity, including .

Results: Direct sequencing of the coding region of gene in the sisters revealed a novel homozygous missense mutation in exon 3 [NM_002303.3], C350G>T [p.C117F]. Detailed information and clinical measurements of these sisters were also collected. Their serum leptin levels were undetectable despite their markedly elevated fat mass.

Conclusions: The mutation of , absence of detectable leptin, and the severe obesity found in these sisters provide the first evidence of monogenic leptin deficiency reported in the continents of North and South America.
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http://dx.doi.org/10.3390/genes10050342DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6562380PMC
May 2019

Identification of a New Candidate Locus for Ebstein Anomaly in 1p36.2.

Mol Syndromol 2018 May 28;9(3):164-169. Epub 2018 Apr 28.

Laboratorio de Biología Molecular y Pruebas Diagnósticas de Alta Complejidad, Bogotá, Colombia.

Ebstein anomaly (EA) is a rare congenital heart defect (CHD) with a poorly characterized genetic etiology. However, some EA patients carry deletions in 1p36, all of which have been reported to carry distal deletions and share loss of the gene, which is currently considered the most likely candidate for EA development in this region. Here, we report a patient with an 11.96-Mb proximal 1p36 deletion, without loss of , who presented with EA and a proximal deletion phenotype. This finding suggests that loss is not required for the development of EA in 1p36 deletions and that the loss of an additional proximal locus in 1p36 is also likely associated with EA. Our data suggest that a distal locus containing the gene and a proximal locus containing the CHD-associated genes and are the most probable etiological factors for EA in patients with 1p36 deletion syndrome.
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http://dx.doi.org/10.1159/000488820DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6006643PMC
May 2018

Identification of clinically relevant phenotypes in patients with Ebstein anomaly.

Clin Cardiol 2018 Mar 22;41(3):343-348. Epub 2018 Mar 22.

Departamento de Investigaciones, Fundación Cardioinfantil-Instituto de Cardiología, Bogotá, Colombia.

Background: Ebstein anomaly (EA) is a heterogeneous congenital heart defect (CHD), frequently accompanied by diverse cardiac and extracardiac comorbidities, resulting in a wide range of clinical outcomes.

Hypothesis: Phenotypic characterization of EA patients has the potential to identify variables that influence prognosis and subgroups with distinct contributing factors.

Methods: A comprehensive cross-sectional phenotypic characterization of 147 EA patients from one of the main referral institutions for CHD in Colombia was carried out. The most prevalent comorbidities and distinct subgroups within the patient cohort were identified through cluster analysis.

Results: The most prevalent cardiac comorbidities identified were atrial septal defect (61%), Wolff-Parkinson-White syndrome (WPW; 27%), and right ventricular outflow tract obstruction (25%). Cluster analysis showed that patients can be classified into 2 distinct subgroups with defined phenotypes that determine disease severity and survival. Patients in cluster 1 represented a particularly homogeneous subgroup with a milder spectrum of disease, including only patients with WPW and/or supraventricular tachycardia (SVT). Cluster 2 included patients with more diverse cardiovascular comorbidities.

Conclusions: This study represents one of the largest phenotypic characterizations of EA patients reported. The data show that EA is a heterogeneous disease, very frequently associated with cardiovascular and noncardiovascular comorbidities. Patients with WPW and SVT represent a homogeneous subgroup that presents with a less severe spectrum of disease and better survival when adequately managed. This should be considered when searching for genetic causes of EA and in the clinical setting.
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http://dx.doi.org/10.1002/clc.22870DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6489938PMC
March 2018

A combined linkage, microarray and exome analysis suggests MAP3K11 as a candidate gene for left ventricular hypertrophy.

BMC Med Genomics 2018 03 5;11(1):22. Epub 2018 Mar 5.

Genetic Epidemiology Unit, Department of Epidemiology, Erasmus University Medical Center, Rotterdam, the Netherlands.

Background: Electrocardiographic measures of left ventricular hypertrophy (LVH) are used as predictors of cardiovascular risk. We combined linkage and association analyses to discover novel rare genetic variants involved in three such measures and two principal components derived from them.

Methods: The study was conducted among participants from the Erasmus Rucphen Family Study (ERF), a Dutch family-based sample from the southwestern Netherlands. Variance components linkage analyses were performed using Merlin. Regions of interest (LOD > 1.9) were fine-mapped using microarray and exome sequence data.

Results: We observed one significant LOD score for the second principal component on chromosome 15 (LOD score = 3.01) and 12 suggestive LOD scores. Several loci contained variants identified in GWAS for these traits; however, these did not explain the linkage peaks, nor did other common variants. Exome sequence data identified two associated variants after multiple testing corrections were applied.

Conclusions: We did not find common SNPs explaining these linkage signals. Exome sequencing uncovered a relatively rare variant in MAPK3K11 on chromosome 11 (MAF = 0.01) that helped account for the suggestive linkage peak observed for the first principal component. Conditional analysis revealed a drop in LOD from 2.01 to 0.88 for MAP3K11, suggesting that this variant may partially explain the linkage signal at this chromosomal location. MAP3K11 is related to the JNK pathway and is a pro-apoptotic kinase that plays an important role in the induction of cardiomyocyte apoptosis in various pathologies, including LVH.
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http://dx.doi.org/10.1186/s12920-018-0339-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5838853PMC
March 2018

Use of AFLP for the study of eukaryotic pathogens affecting humans.

Infect Genet Evol 2018 09 19;63:360-369. Epub 2017 Sep 19.

Center for Cellular and Molecular Biology of Diseases, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Edificio 219, Ciudad del Saber, Apartado 0843-01103, Ciudad de Panamá, Panama.. Electronic address:

Amplified fragment length polymorphism (AFLP) is a genotyping technique based on PCR amplification of specific restriction fragments from a particular genome. The methodology has been extensively used in plant biology to solve a variety of scientific questions, including taxonomy, molecular epidemiology, systematics, population genetics, among many others. The AFLP share advantages and disadvantages with other types of molecular markers, being particularly useful in organisms with no previous DNA sequence knowledge. In eukaryotic pathogens, the technique has not been extensively used, although it has the potential to solve many important issues as it allows the simultaneous examination of hundreds or even thousands of polymorphic sites in the genome of the organism. Here we describe the main applications published on the use of AFLP in eukaryotic pathogens, with emphasis in species of the groups fungi, protozoa and helminths, and discuss the role of this methodology in the context of new techniques derived from the advances of the next generation sequencing.
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http://dx.doi.org/10.1016/j.meegid.2017.09.017DOI Listing
September 2018

Improving the evaluation of milestones for students completing a clinical genetics elective.

Genet Med 2017 12 11;19(12). Epub 2017 May 11.

Center For Research in Genetics and Genomics (CIGGUR). GENIUROS Research Group, School of Medicine and Health Sciences. Universidad del Rosario. Bogota, Colombia.

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http://dx.doi.org/10.1038/gim.2017.62DOI Listing
December 2017

Genome-wide discovery and development of polymorphic microsatellites from Leishmania panamensis parasites circulating in central Panama.

Parasit Vectors 2015 Oct 12;8:527. Epub 2015 Oct 12.

Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Building 219, Ciudad del Saber, Apartado 0843-01103, Ciudad de Panamá, República de Panamá.

Background: The parasite Leishmania panamensis is the main cause of leishmaniasis in Panama. The disease is largely uncontrolled, with a rising incidence and no appropriate control measures. While microsatellites are considered some of the best genetic markers to study population genetics and molecular epidemiology in these and other parasites, none has been developed for L. panamensis.

Findings: Here we have developed and tested a new panel of microsatellites for this species, based on high-throughput genome-wide screening. The new set of microsatellites is composed of seventeen loci, mainly spanning trinucleotide or longer motifs. We have evaluated the sensitivity and specificity of the panel based on a sample of 27 isolates obtained from cutaneous leishmaniasis patients from central Panama and also several reference species from both L. (Leishmania) and L. (Viannia) subgenera. The genetic equilibrium was assessed both intra- and inter-loci, while the reproductive mode was evaluated using several tests. The new SSR panel shows high polymorphism and sensitivity, as well as good specificity. The preliminary data described here for L. panamensis suggest extensive departure from Hardy-Weinberg proportions, significant linkage disequilibrium and strong deficit of heterozygotes. Several recombination tests involving multilocus linkage disequilibrium and a phylogenetic approach allowed rejection of frequent recombination in our dataset.

Conclusions: The genome-wide strategy described here proved to be useful to identify and test new polymorphic SSR loci in Leishmania. The new panel of polymorphic microsatellites is a valuable contribution to the existing molecular markers for the study of genetic structure and other aspects of this important species.
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http://dx.doi.org/10.1186/s13071-015-1153-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4603350PMC
October 2015

Transcriptional regulator PRDM12 is essential for human pain perception.

Nat Genet 2015 Jul 25;47(7):803-8. Epub 2015 May 25.

Friedrich-Baur-Institute, Ludwig Maximilians University Munich, Munich, Germany.

Pain perception has evolved as a warning mechanism to alert organisms to tissue damage and dangerous environments. In humans, however, undesirable, excessive or chronic pain is a common and major societal burden for which available medical treatments are currently suboptimal. New therapeutic options have recently been derived from studies of individuals with congenital insensitivity to pain (CIP). Here we identified 10 different homozygous mutations in PRDM12 (encoding PRDI-BF1 and RIZ homology domain-containing protein 12) in subjects with CIP from 11 families. Prdm proteins are a family of epigenetic regulators that control neural specification and neurogenesis. We determined that Prdm12 is expressed in nociceptors and their progenitors and participates in the development of sensory neurons in Xenopus embryos. Moreover, CIP-associated mutants abrogate the histone-modifying potential associated with wild-type Prdm12. Prdm12 emerges as a key factor in the orchestration of sensory neurogenesis and may hold promise as a target for new pain therapeutics.
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http://dx.doi.org/10.1038/ng.3308DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7212047PMC
July 2015

BMP15 c.-9C>G promoter sequence variant may contribute to the cause of non-syndromic premature ovarian failure.

Reprod Biomed Online 2014 Nov 12;29(5):627-33. Epub 2014 Aug 12.

Unidad de Genética, Grupo GENIUROS, Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia; Departamento de Fertilidad Humana, Genética Molecular de Colombia, Bogotá, Colombia. Electronic address:

BMP15 has drawn particular attention in the pathophysiology of reproduction, as its mutations in mammalian species have been related to different reproductive phenotypes. In humans, BMP15 coding regions have been sequenced in large panels of women with premature ovarian failure (POF), but only some mutations have been definitely validated as causing the phenotype. A functional association between the BMP15 c.-9C>G promoter polymorphism and cause of POF have been reported. The aim of this study was to determine the potential functional effect of this sequence variant on specific BMP15 promoter transactivation disturbances. Bioinformatics was used to identify transcription factor binding sites located on the promoter region of BMP15. Reverse transcription polymerase chain reaction was used to study specific gene expression in ovarian tissue. Luciferase reporter assays were used to establish transactivation disturbances caused by the BMP15 c.-9C>G variant. The c.-9C>G variant was found to modify the PITX1 transcription factor binding site. PITX1 and BMP15 co-expressed in human and mouse ovarian tissue, and PITX1 transactivated both BMP15 promoter versions (-9C and -9G). It was found that the BMP15 c.-9G allele was related to BMP15 increased transcription, supporting c.-9C>G as a causal agent of POF.
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http://dx.doi.org/10.1016/j.rbmo.2014.07.018DOI Listing
November 2014

A pseudopterane diterpene isolated from the octocoral Pseudopterogorgia acerosa inhibits the inflammatory response mediated by TLR-ligands and TNF-alpha in macrophages.

PLoS One 2013 16;8(12):e84107. Epub 2013 Dec 16.

Centro de Biología Celular y Molecular de Enfermedades, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, Ciudad de Panamá, Panamá

Several diterpenoids isolated from terrestrial and marine environments have been identified as important anti-inflammatory agents. Although considerable progress has been made in the area of anti-inflammatory treatment, the search for more effective and safer compounds is a very active field of research. In this study we investigated the anti-inflammatory effects of a known pseudopterane diterpene (referred here as compound 1) isolated from the octocoral Pseudopterogorgia acerosa on the tumor necrosis factor- alpha (TNF-α) and TLRs- induced response in macrophages. Compound 1 inhibited the expression and secretion of the inflammatory mediators TNF-α, interleukin (IL)-6, IL-1β, nitric oxide (NO), interferon gamma-induced protein 10 (IP-10), ciclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS) and monocyte chemoattractant protein-1 (MCP-1) induced by LPS in primary murine macrophages. This effect was associated with the inhibition of IκBα degradation and subsequent activation of NFκB. Compound 1 also inhibited the expression of the co-stimulatory molecules CD80 and CD86, which is a hallmark of macrophage activation and consequent initiation of an adaptive immune response. The anti-inflammatory effect was not exclusive to LPS because compound 1 also inhibited the response of macrophages to TNF-α and TLR2 and TLR3 ligands. Taken together, these results indicate that compound 1 is an anti-inflammatory molecule, which modulates a variety of processes occurring in macrophage activation.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0084107PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3865250PMC
September 2014

AFLP polymorphisms allow high resolution genetic analysis of American Tegumentary Leishmaniasis agents circulating in Panama and other members of the Leishmania genus.

PLoS One 2013 9;8(9):e73177. Epub 2013 Sep 9.

Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT-AIP), Ciudad de Panamá, Panamá ; Department of Biotechnology, Acharya Nagarjuna University, Guntur, India.

American Tegumentary Leishmaniasis is caused by parasites of the genus Leishmania, and causes significant health problems throughout the Americas. In Panama, Leishmania parasites are endemic, causing thousands of new cases every year, mostly of the cutaneous form. In the last years, the burden of the disease has increased, coincident with increasing disturbances in its natural sylvatic environments. The study of genetic variation in parasites is important for a better understanding of the biology, population genetics, and ultimately the evolution and epidemiology of these organisms. Very few attempts have been made to characterize genetic polymorphisms of parasites isolated from Panamanian patients of cutaneous leishmaniasis. Here we present data on the genetic variability of local isolates of Leishmania, as well as specimens from several other species, by means of Amplified Fragment Length Polymorphisms (AFLP), a technique seldom used to study genetic makeup of parasites. We demonstrate that this technique allows detection of very high levels of genetic variability in local isolates of Leishmania panamensis in a highly reproducible manner. The analysis of AFLP fingerprints generated by unique selective primer combinations in L. panamensis suggests a predominant clonal mode of reproduction. Using fluorescently labeled primers, many taxon-specific fragments were identified which may show potential as species diagnostic fragments. The AFLP permitted a high resolution genetic analysis of the Leishmania genus, clearly separating certain groups among L. panamensis specimens and highly related species such as L. panamensis and L. guyanensis. The phylogenetic networks reconstructed from our AFLP data are congruent with established taxonomy for the genus Leishmania, even when using single selective primer combinations. Results of this study demonstrate that AFLP polymorphisms can be informative for genetic characterization in Leishmania parasites, at both intra and inter-specific levels.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0073177PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3767818PMC
June 2014

Mutation study of Spanish patients with hereditary hemorrhagic telangiectasia and expression analysis of Endoglin and ALK1.

Hum Mutat 2006 Mar;27(3):295

Centro de Investigaciones Biologicas, Madrid, Spain.

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant and age-dependent vascular disorder originated by mutations in Endoglin (ENG) or activin receptor-like kinase-1 (ALK1, ACVRL1) genes. The first large series HHT analysis in Spanish population has identified mutations in 17 unrelated families. Ten different mutations in ALK1 and six in ENG genes were found. Six unrelated families had a mutation in ENG gene, four representing new mutations, p.Y258fs, pV323fs, p.F279fs (c.834_837del CTTC), and p.F279fsdupC. Eleven unrelated families harboured mutations in ALK1; ten were new mutations identified as p.H328P, p.R145fs, p.G68C, p.A377T, p.H297R, p.M376T, p.C36Y, p.H328P, p.T82del and p.R47P. Overall, ALK1 mutations (HHT2) were predominant over ENG mutations (HHT1), in agreement with data reported for other Mediterranean countries (France, Italy), but at variance with Northern Europe or North America. Endoglin expression in HHT1 or HHT2 activated monocytes and blood outgrowth endothelial cells (BOECs) from older patients was well below the theoretical 50% level expected from the HHT1 haploinsufficiency model, suggesting that the pathogenic endoglin haploinsufficiency leading to the HHT phenotype is age-dependent. Interestingly, ALK1 protein levels of HHT BOECs in some missense ALK1 mutants were similar to controls. In vitro expression of these ALK1 constructs suggests that, in addition to the haploinsufficiency model, certain ALK1 mutants may inhibit the function of the wild type allele.
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http://dx.doi.org/10.1002/humu.9413DOI Listing
March 2006