Biology subjects

Blanco, P.

Publications and source records attributed to Blanco, P..

9 recordsLinked to original sources

bioRxiv2026

Extracellular DNASE1L3 dysfunction fuels obesity-driven inflammation and metabolic syndrome

Obesity, a global health crisis affecting 16% of the world population, is characterized by chronic inflammation that contributes to health complications such as type 2 diabetes and metabolic dysfunction-associated steatotic liver disease (MASLD). Emerging evidence suggests that self-DNA released from dying cells aberrantly activates inflammatory responses during obesity. However, the role of extracellular deoxyribonucleases (DNASEs), which at steady state regulate abundance of extracellular self-DNA, remains poorly understood in this context. Here, we show that individuals with obesity exhibit elevated levels of circulating cell-free DNA (cfDNA) with a distinctive end-motif signature, anti-DNASE1L3 autoantibodies and a reduction in circulating DNASE activity. These cfDNA alterations correlate with the severity of obesity and can be corrected by therapeutic intervention such as bariatric surgery. Similarly, mice fed a high-fat diet (HFD) displayed increased cfDNA levels and decreased DNASE activity. Genetic deficiency of the extracellular nuclease DNASE1L3 in mice worsened HFD-induced metabolic complications, including glucose intolerance, insulin resistance, MASLD, and metabolic tissue inflammation. Conversely, targeted supplementation of DNASE1L3 in the liver using adeno-associated viral vectors protected obese mice from developing MASLD and liver inflammation. These findings uncover a novel role of DNASE1L3 in controlling obesity-associated inflammation and its potential therapeutic use for preventing metabolic disease.

pathology↗

bioRxiv2026

Large-scale recovery of integron cassettes for gene discovery screens

Integrons capture and stockpile adaptive genes encoded in modular mobile genetic elements called integron cassettes (ICs). Present in 17% of bacterial genomes, integrons can harbor hundreds of cassettes, representing a hotspot of genetic variability. Some ICs encode antimicrobial or phage resistance genes, but most remain functionally uncharacterized, representing an untapped source of genes of biotechnological interest. Here, we present two tools, the cassette gatherer and hunter, that allow the swift establishment of libraries of genes either from genetically tractable strains or directly from DNA. By re-engineering a class 1 integron, these platforms capture single cassettes in a sequence and function-independent manner. When applied to Vibrio genomes, they recovered hundreds of single cassettes per assay with >99% specificity. To validate the usability of our tools for the discovery of new genes, we subjected these libraries to screens against phages ICP2 and T4, and identified nine phage-defense systems, including five previously undescribed. Hence, these tools provide a fast and simple method to recover thousands of ICs, in a way amenable to gene-discovery screens.

microbiology↗

bioRxiv2024

Mobile Integrons Encode Phage Defence Systems

Integrons are bacterial genetic elements that capture, stockpile and modulate the expression of genes encoded in integron cassettes. Mobile Integrons (MI) are borne on plasmids, acting as a vehicle for hundreds of antimicrobial resistance genes among key pathogens. These elements also carry gene cassettes of unknown function (gcus) whose role and adaptive value remains unexplored. Here we show that gcus encode phage resistance systems, many of which are novel. Bacteriophage resistance integron cassettes (BRiCs) can be combined and mixed with resistance cassettes to produce multiphage or drug/phage-resistance. The fitness costs of BRiCs are variable, dependent on the genetic context, and can be modulated by changing the order of cassettes in the array. Hence, MIs act as highly mobile, low-cost defense islands. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=150 SRC="FIGDIR/small/601719v4_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@965766org.highwire.dtl.DTLVardef@442763org.highwire.dtl.DTLVardef@7600d4org.highwire.dtl.DTLVardef@13068ca_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOSummary FigureC_FLOATNO Novel phage defense systems identified in Mobile Integrons. We confronted genes of unknown function from mobile integrons against a panel of phage. We characterized 13 Bacteriophage Resistance integron Cassettes (BRiCs) and confirmed their function in Klebsiella pneumoniae and Pseudomonas aeruginosa. Combined with other cassettes, BRiCs produce multi-phage/antibiotic resistance. Additionally, their cost can be reduced in an array. C_FIG

microbiology↗

bioRxiv2023

IDENTIFICATION OF PROMOTER ACTIVITY IN GENE-LESS CASSETTES FROM VIBRIONACEAE SUPERINTEGRONS

Integrons are genetic platforms that acquire new genes encoded in integron cassettes (ICs), building arrays of adaptive functions. ICs generally encode promoterless genes, whose expression relies on the platform-associated Pc promoter, with the cassette array functioning as an operon-like structure regulated by the distance to the Pc. This is relevant in large sedentary chromosomal integrons (SCIs) carrying hundreds of ICs, like those in Vibrio species. We selected 29 gene-less cassettes in four Vibrio SCIs, and explored whether their function could be related to the transcription regulation of adjacent ICs. We show that most gene-less cassettes have promoter activity on the sense strand, enhancing the expression of downstream cassettes. Additionally, we identified the transcription start sites of gene-less ICs through 5-RACE. Accordingly, we found that most of the superintegron in Vibrio cholerae is not silent. These promoter cassettes can trigger the expression of a silent dfrB9 cassette downstream, increasing trimethoprim resistance >512-fold in V. cholerae and Escherichia coli. Furthermore, one cassette with an antisense promoter can reduce trimethoprim resistance when cloned downstream. Our findings highlight the regulatory role of gene-less cassettes in the expression of adjacent cassettes, emphasizing their significance in SCIs and their clinical importance if captured by mobile integrons.

microbiology↗

bioRxiv2023

Chromosomal Integrons are Genetically and Functionally Isolated Units of Genomes

Integrons are genetic elements that increase the evolvability of bacteria by capturing new genes and stockpiling them in arrays. Sedentary chromosomal integrons (SCIs), can be massive and highly stabilized structures encoding hundreds of genes, whose function remains generally unknown. SCIs have co-evolved with the host for aeons and are highly intertwined with their physiology from a mechanistic point of view. But, paradoxically, other aspects, like their variable content and location within the genome, suggest a high genetic and functional independence. In this work, we have explored the connection of SCIs to their host genome using as a model the Superintegron (SI), a 179-cassette long SCI in the genome of Vibrio cholerae N16961. We have relocated and deleted the SI using SeqDelTA, a novel method that allows to counteract the strong stabilization conferred by toxin-antitoxin systems within the array. We have characterized in depth the impact in V. choleraes physiology, measuring fitness, chromosome replication dynamics, persistence, transcriptomics, phenomics and virulence. The deletion of the SI did not produce detectable effects in any condition, proving that -despite millions of years of co-evolution-, SCIs are genetically and functionally isolated units of genomes.

microbiology↗

bioRxiv2019

Novel inducers of the expression of multidrug efflux pumps that trigger Pseudomonas aeruginosa transient antibiotic resistance

The study of the acquisition of antibiotic resistance (AR) has mainly focused in inherited processes, namely mutations and acquisition of AR genes. However, inducible, non-inheritable AR has received less attention and most information in this field derives from the study of antibiotics as inducers of their associated resistance mechanisms. Less is known about non-antibiotic compounds or situations that can induce AR during infection. Multidrug resistance efflux pumps are a category of AR determinants characterized by the tightly regulation of their expression. Their contribution to acquired AR relies in their overexpression. Herein we analyzed potential inducers of the expression of the chromosomally-encoded Pseudomonas aeruginosa clinically-relevant efflux pumps, MexCD-OprJ and MexAB-OprM. For this purpose, we developed a set of luxCDABE-based P. aeruginosa biosensor strains, which allows the high-throughput analysis of compounds able of modifying the expression of these efflux pumps. Using these strains, we analyzed a set of 240 compounds present in Biolog Phenotype Microarrays. Several inducers of the expression of the genes that encode these efflux pumps were found. The study focused in dequalinium chloride, procaine and atropine, compounds that can be found in clinical settings. Using real-time PCR, we confirmed that these compounds indeed induce the expression of mexCD-oprJ. In addition, P. aeruginosa presents lower susceptibility to ciprofloxacin (a MexCD-OprJ substrate) when dequalinium chloride, procaine or atropine are present. This work emphasizes the need of studying compounds that can trigger transient AR during antibiotic treatment, a phenotype difficult to discover using classical susceptibility tests.

microbiology↗

bioRxiv2018

Integrating molecular markers and environmental covariates to interpret genotype by environment interaction in rice (Oryza sativa L.) grown in temperate areas

Understanding the genetic and environmental basis of genotype x environment interaction (GxE) is of fundamental importance in plant breeding. If we consider GxE in the context of genotype x year interactions (GxY), predicting which lines will have stable and superior performance across years is an important challenge for breeders. A better understanding of the factors that contribute to the overall grain yield and quality of rice (Oryza sativa L.) will lay the foundation for developing new breeding and selection strategies for combining high quality, with high yield. In this study, we used molecular marker data and environmental covariates (EC) simultaneously to predict rice yield, milling quality traits and plant height in untested environments (years), using both reaction norm models and partial least squares (PLS), in two rice breeding populations (indica and tropical japonica). We also sought to explain GxE by differential quantitative trait loci (QTL) expression in relation to EC. Our results showed that PLS models trained with both molecular markers and EC gave better prediction accuracies than reaction norm models when predicting future years. We also detected several milling quality QTL that showed a differential expression conditional on humidity and solar radiation, providing insight for the main environmental factors affecting milling quality in temperate rice growing areas.

genomics↗

bioRxiv2018

A novel method for comparison of arterial remodeling in hypertension: quantification of arterial trees and recognition of remodeling patterns on histological sections

Remodeling of spatially heterogeneous arterial trees is routinely quantified on tissue sections by averaging linear dimensions, with lack of comparison between different organs and models. The impact of experimental models or hypertension treatment modalities on organ-specific vascular remodeling remains undefined. A wide variety of arterial remodeling types has been demonstrated for hypertensive models, which include differences across organs. The purpose of this study was to reassess methods for measurement of arterial remodeling and to establish a morphometric algorithm for standard and comparable quantification of vascular remodeling in hypertension in different vascular beds. We performed a novel and comprehensive morphometric analysis of terminal arteries in the brain, heart, lung, liver, kidney, spleen, stomach, intestine, skin, skeletal muscle, and adrenal glands of control and Goldblatt hypertensive rats on routinely processed tissue sections. Mean dimensions were highly variable but grouping them into sequential 5 m intervals permitted creation of reliable linear regression equations and complex profiles. Averaged arterial dimensions demonstrated seven remodeling patterns that were distinct from conventional inward-outward and hypertrophic-eutrophic definitions. Numerical modeling predicted at least twenty variants of arterial spatial conformations. Recognition of remodeling variants was not possible using averaged dimensions, their ratios, or the remodeling and growth index. To distinguish remodeling patterns, a three-dimensional modeling was established and tested. The proposed algorithm permits quantitative analysis of arterial remodeling in different organs and may be applicable for comparative studies between animal hypertensive models and in human hypertension. Arterial wall tapering is the most important factor to consider in arterial morphometry, while perfusion fixation with vessel relaxation is not necessary. Terminal arteries in organs undergo the same remodeling pattern in Goldblatt rats, except for organs with hemodynamics affected by the arterial clip. The existing remodeling nomenclature should be replaced by a numerical classification applicable to any type of arterial remodeling.\n\nAuthor summaryArterial hypertension effects modern nations and is characterised by systemic hypertensive angiopathy that affects all organs. Arterial remodeling is a main factor to be analyzed in animal models and human. Despite abundant data, there is a significant lack of comparative analysis on arterial remodeling. The data from the present study have established a novel methodological approach to assess and compare arterial remodeling in hypertension. We have developed an effective algorithm for morphometry of intra-organ arteries to standardize remodeling assessment and allow comparisons between different hypertensive models, organs and species. Our study opens the possibility to assess remodeling using conventional widely used histological tissue sections with no need for special perfusion-fixation. The method will elucidate the improvement and development of animal models of hypertension, and enhance the assessment of experimental therapeutic modalities.

pathology↗

bioRxiv2018

Biolog phenotype microarray: a tool for the identification of multidrug resistance efflux pumps inducers

Overexpression of multidrug resistance efflux pumps is a relevant mechanism of antibiotic resistance for bacterial pathogens. These systems use to present low levels of basal expression. However, they can be induced by environmental signals or stresses which can lead to situations of phenotypic induced resistance. In contrast to efflux pumps substrates, inducers of these systems have not been thoroughly studied. In this work, we have applied a novel high-throughput methodology in order to identify inducer molecules of the Stenotrophomonas maltophilia SmeVWX and SmeYZ efflux pumps. To that goal, bioreporters in which the expression of the yellow fluorescent protein is linked to the activity of either the smeVWX or the smeYZ promoters were developed and used for the screening of potential inducers of the expression of these efflux pumps using Biolog phenotype microarrays. Confirmation of induction was carried out measuring YFP production along the bacterial growth and by flow cytometry; mRNA levels of smeV and smeY were also determined by real-time RT-PCR after exposure to the selected compounds. Among the 144 tested compounds, iodoacetate, clioquinol (5-chloro-7-iodo-8-hydroxyquinoline) and sodium selenite were found to be smeVWX inducers, while boric acid, erythromycin, chloramphenicol and lincomycin are able to trigger the expression of smeYZ. While the presence of the inducers allowed a decrease in the susceptibility to antibiotics that are known substrates of the efflux pumps, our results indicate that these efflux pumps did not contribute to S. maltophilia resistance to the analyzed inducers.\n\nImportanceMultidrug efflux pumps constitute a category of elements involved in the cellular response to stress that is universally represented; from bacteria to human cells. Besides playing basic roles in cell physiology, these elements are critical elements in the resistance to therapeutic agents, including anti-cancer drugs, antifungals and antibiotics. Stable-inheritable resistance is achieved through mutations in regulatory elements that allow overexpression of these systems. However, much less is known on the effectors, or growing conditions, that might induce their expression, leading to a situation of transient-phenotypic resistance, not detectable by current susceptibility tests, unless the inducer in known. Herein we present a methodology amenable for the high-throughput screening of efflux pumps inducers. The use of phenotype microarrays linked to fluorescence reporters have allowed to identify a set of different inducers for smeVWX and smeYZ. Notably, induction seems to be uncoupled from the detoxification of the inducers by the corresponding efflux pumps. The mechanism of action of each of the inducers for inhibiting bacterial growth allowed us to propose that smeVWX is likely induced as a response to thiol-reactive compounds, while smeYZ is induced by ribosome-targeting antimicrobials. Although applied to a specific bacterium, this method is of application to any type of organism and efflux pump, changing the growing conditions in the case of eukaryotic cells. Since the presence of inducers may change the cell response to therapeutic drugs, the identification of these molecules is of clinical relevance.

microbiology↗