Genomics of the expanding pine pathogen Lecanosticta acicola reveals patterns of ongoing genetic admixture

Lecanosticta acicola is the causal agent for brown spot needle blight that affects pine trees across the northern hemisphere. Based on marker genes and microsatellite data, two distinct lineages have been identified that were introduced into Europe on two separate occasions. Despite their overall distinct geographic distribution, they have been found to coexist in regions of northern Spain and France. Here, we present the first genome-wide study of Lecanosticta acicola, including assembly of the reference genome and a population genomics analysis of 70 natural isolates from northern Spain. We show that most of the isolates belong to the southern lineage but show signs of introgression with northern lineage isolates, indicating mating between the two lineages. We also identify phenotypic differences between the two lineages based on the activity profiles of 20 enzymes, with introgressed strains being more phenotypically similar to members of the southern lineage. In conclusion, we show undergoing genetic admixture between the two main lineages of L. acicola in a region of recent expansion.

IMPORTANCE

Lecanosticta acicola is a fungal pathogen causing severe defoliation, growth reduction, and even death in more than 70 conifer species. Despite the increasing incidence of this species, little is known about its population dynamics. Two divergent lineages have been described that have now been found together in regions of France and Spain, but it is unknown how these mixed populations evolve. Here we present the first reference genome for this important plant pathogenic fungi and use it to study the population genomics of 70 isolates from an affected forest in the north of Spain. We find signs of introgression between the two main lineages, indicating that active mating is occurring in this region which could propitiate the appearance of novel traits in this species. We also study the phenotypic differences across this population based on enzymatic activities on 20 compounds.

BioISO: An Objective-Oriented Application for Assisting the Curation of Genome-Scale Metabolic Models

As the reconstruction of Genome-Scale Metabolic Models (GEMs) becomes standard practice in systems biology, the number of organisms having at least one metabolic model is peaking at an unprecedented scale. The automation of laborious tasks, such as gap-finding and gap-filling, allowed the development of GEMs for poorly described organisms. However, the quality of these models can be compromised by the automation of several steps, which may lead to erroneous phenotype simulations. Biological networks constraint-based In Silico Optimisation (BioISO) is a computational tool aimed at accelerating the reconstruction of GEMs. This tool facilitates manual curation steps by reducing the large search spaces often met when debugging in silico biological models. BioISO uses a recursive relation-like algorithm and Flux Balance Analysis (FBA) to evaluate and guide debugging of in silico phenotype simulations. The potential of BioISO to guide the debugging of model reconstructions was showcased and compared with the results of two other state-of-the-art gap-filling tools (Meneco and fastGapFill). In this assessment, BioISO is better suited to reducing the search space for errors and gaps in metabolic networks by identifying smaller ratios of dead-end metabolites. Furthermore, BioISO was used as Meneco's gap-finding algorithm to reduce the number of proposed solutions for filling the gaps.

A chromosome-level reference genome for the common octopus, Octopus vulgaris (Cuvier, 1797)

Cephalopods are emerging animal models and include iconic species for studying the link between genomic innovations and physiological and behavioral complexities. Coleoid cephalopods possess the largest nervous system among invertebrates, both for cell counts and brain-to-body ratio. Octopus vulgaris has been at the center of a long-standing tradition of research into diverse aspects of cephalopod biology, including behavioral and neural plasticity, learning and memory recall, regeneration, and sophisticated cognition. However, no chromosome-scale genome assembly was available for O. vulgaris to aid in functional studies. To fill this gap, we sequenced and assembled a chromosome-scale genome of the common octopus, O. vulgaris. The final assembly spans 2.8 billion basepairs, 99.34% of which are in 30 chromosome-scale scaffolds. Hi-C heatmaps support a karyotype of 1n = 30 chromosomes. Comparisons with other octopus species' genomes show a conserved octopus karyotype and a pattern of local genome rearrangements between species. This new chromosome-scale genome of O. vulgaris will further facilitate research in all aspects of cephalopod biology, including various forms of plasticity and the neural machinery underlying sophisticated cognition, as well as an understanding of cephalopod evolution.

Complications of Synthetic Midurethral Slings: Is There a Relevant Discrepancy Between Observational Data and Clinical Trials?

CONTEXT

The complications of synthetic midurethral slings (MUSs) in women with stress urinary incontinence (SUI) have become a globally debated issue.

OBJECTIVE

To systematically review the short- and long-term complications of mesh slings reported in observational data compared with clinical trial data, to determine whether the complication rates from clinical trials reflects "real-world" observational data.

EVIDENCE ACQUISITION

PubMed and Cochrane Library were searched. Methods as detailed in Preferred Reporting Items for Systematic Reviews and Meta-analyses and Cochrane Handbook for Systematic Reviews of Interventions were followed.

EVIDENCE SYNTHESIS

Thirty registries/databases including 709 335 MUS procedures (1-22 yr of follow-up) were identified. MUS procedures were associated with intraoperative bladder perforation in 0.86-3.6%, urethral perforation in 0-0.1%, vascular injury in 0.04-0.1%, voiding lower urinary tract symptoms (LUTS) in 1.47-3.5%, vaginal exposure in 0.2-1.9%, and reoperation in up to 9% of cases. Forty-three randomised clinical trials were identified, including 6284 women who underwent MUS procedures and 2177 women who underwent other interventions (1-10 yr of follow-up). MUS procedures were associated with urinary tract perforation in 2.58%, vaginal injury in 1.43%, de novo voiding LUTS in 4.37%, de novo storage LUTS in 5.41%, mesh extrusion/exposure (vaginal/urinary tract) in 2.54%, dyspareunia in 2.26%, pain (pelvic/suprapubic/perineal) in 2.83%, and reoperation for complications required in 1.82% of cases. Meta-analyses of the randomised controlled trials revealed that retropubic MUSs were associated with more events of urinary tract perforation (risk ratio [RR] 9.81, 95% confidence interval [CI] 5.05-19.04, high certainty of evidence [COE]) and voiding LUTS (RR 1.57, 95% CI 1.19-2.07, high COE) than transobturator MUSs. MUSs were associated with more events of pain than mini-slings (RR 1.72, 95% CI 1.04-2.87, moderate COE).

CONCLUSIONS

Short- and long-term data on complications of polypropylene mesh used for female SUI are fairly comparable when using outcome data from well-designed clinical trials or from less structured prospective or retrospective registries. Comparisons have to be made with caution since the two systems of data collection are inherently incomparable. This knowledge should be incorporated in the discussion on how to implement polypropylene mesh for female stress incontinence.

PATIENT SUMMARY

In order to know whether mesh tapes used for treating stress incontinence work well and are safe, high-quality information is important. It appears that well-designed clinical studies give similar results to large registration databases. These data should be interpreted with caution in view of the different ways the information was collected. These results will help physicians and patients understand the risks of mesh tapes.

Development of a novel streamlined workflow (AACRE) and database (inCREDBle) for genomic analysis of carbapenem-resistant Enterobacterales

In response to the threat of increasing antimicrobial resistance, we must increase the amount of available high-quality genomic data gathered on antibiotic-resistant bacteria. To this end, we developed an integrated pipeline for high-throughput long-read sequencing, assembly, annotation and analysis of bacterial isolates and used it to generate a large genomic data set of carbapenemase-producing Enterobacterales (CPE) isolates collected in Spain. The set of 461 isolates were sequenced with a combination of both Illumina and Oxford Nanopore Technologies (ONT) DNA sequencing technologies in order to provide genomic context for chromosomal loci and, most importantly, structural resolution of plasmids, important determinants for transmission of antimicrobial resistance. We developed an informatics pipeline called Assembly and Annotation of Carbapenem-Resistant Enterobacteriaceae (AACRE) for the full assembly and annotation of the bacterial genomes and their complement of plasmids. To explore the resulting genomic data set, we developed a new database called inCREDBle that not only stores the genomic data, but provides unique ways to filter and compare data, enabling comparative genomic analyses at the level of chromosomes, plasmids and individual genes. We identified a new sequence type, ST5000, and discovered a genomic locus unique to ST15 that may be linked to its increased spread in the population. In addition to our major objective of generating a large regional data set, we took the opportunity to compare the effects of sample quality and sequencing methods, including R9 versus R10 nanopore chemistry, on genome assembly and annotation quality. We conclude that converting short-read and hybrid microbial sequencing and assembly workflows to the latest nanopore chemistry will further reduce processing time and cost, truly enabling the routine monitoring of resistance transmission patterns at the resolution of complete chromosomes and plasmids.

Chromosome-level assembly and annotation of the Xyrichtys novacula (Linnaeus, 1758) genome

The pearly razorfish (Xyrichtys novacula), commonly known as raor in the Balearic Islands, is a wrasse within the family Labridae. This fish species has particular biological and socio-cultural characteristics making it an ideal model organism in the fields of behavioural ecology, molecular ecology and conservation biology. In this study, we present the first annotated chromosome-level assembly for this species. Sequencing involved a combination of long reads with Oxford Nanopore Technologies, Illumina paired-end short reads (2 × 151 bp), Hi-C and RNA-seq from different tissues. The nuclear genome assembly has a scaffold N50 of 34.33 Mb, a total assembly span of 775.53 Mb and 99.63% of the sequence assembled into 24 superscaffolds, consistent with its known karyotype. Quality metrics revealed a consensus accuracy (QV) of 42.92 and gene completeness > 98%. The genome annotation resulted in 26,690 protein-coding genes and 12,737 non-coding transcripts. The coding regions encoded 39,613 unique protein products, 93% of them with assigned function. Overall, the publication of the X. novacula's reference genome will broaden the scope and impact of genomic research conducted on this iconic and colourful species.

Chromosome-level genome assembly of Lilford's wall lizard, Podarcis lilfordi (Günther, 1874) from the Balearic Islands (Spain)

The Mediterranean lizard Podarcis lilfordi is an emblematic species of the Balearic Islands. The extensive phenotypic diversity among extant isolated populations makes the species a great insular model system for eco-evolutionary studies, as well as a challenging target for conservation management plans. Here we report the first high quality chromosome-level assembly and annotation of the P. lilfordi genome, along with its mitogenome, based on a mixed sequencing strategy (10X Genomics linked reads, Oxford Nanopore Technologies long reads and Hi-C scaffolding) coupled with extensive transcriptomic data (Illumina and PacBio). The genome assembly (1.5 Gb) is highly contiguous (N50 = 90 Mb) and complete, with 99% of the sequence assigned to candidate chromosomal sequences and >97% gene completeness. We annotated a total of 25,663 protein-coding genes translating into 38,615 proteins. Comparison to the genome of the related species Podarcis muralis revealed substantial similarity in genome size, annotation metrics, repeat content, and a strong collinearity, despite their evolutionary distance (~18-20 MYA). This genome expands the repertoire of available reptilian genomes and will facilitate the exploration of the molecular and evolutionary processes underlying the extraordinary phenotypic diversity of this insular species, while providing a critical resource for conservation genomics.

A chromosome-level genome assembly enables the identification of the follicule stimulating hormone receptor as the master sex-determining gene in the flatfish Solea senegalensis

Sex determination (SD) shows huge variation among fish and a high evolutionary rate, as illustrated by the Pleuronectiformes (flatfishes). This order is characterized by its adaptation to demersal life, compact genomes and diversity of SD mechanisms. Here, we assembled the Solea senegalensis genome, a flatfish of great commercial value, into 82 contigs (614 Mb) combining long- and short-read sequencing, which were next scaffolded using a highly dense genetic map (28,838 markers, 21 linkage groups), representing 98.9% of the assembly. Further, we established the correspondence between the assembly and the 21 chromosomes by using BAC-FISH. Whole genome resequencing of six males and six females enabled the identification of 41 single nucleotide polymorphism variants in the follicle stimulating hormone receptor (fshr) consistent with an XX/XY SD system. The observed sex association was validated in a broader independent sample, providing a novel molecular sexing tool. The fshr gene displayed differential expression between male and female gonads from 86 days post-fertilization, when the gonad is still an undifferentiated primordium, concomitant with the activation of amh and cyp19a1a, testis and ovary marker genes, respectively, in males and females. The Y-linked fshr allele, which included 24 nonsynonymous variants and showed a highly divergent 3D protein structure, was overexpressed in males compared to the X-linked allele at all stages of gonadal differentiation. We hypothesize a mechanism hampering the action of the follicle stimulating hormone driving the undifferentiated gonad toward testis.

Headache frequency among 71,267 admissions to an adult medical emergency in the city of Recife in 2021

Introduction Pain is a warning sign that can mean great suffering and risk of death, and makes the patient seek a medical emergency for evaluation by specialists. Objective To verify the frequency of patients with headache disorders among those with pain admitted to the emergency department of a private hospital in Recife, Brazil, during the year 2021, using the international classification of diseases (ICD). Methods This is a retrospective study. The authors used the Business Intelligence (BI) tool to verify the number of admission by the ICD 10 recorded in 2021 in the emergency room of Hospital Unimed Recife III. The sample described in this study covers only the ICDs that had the word DOR (pain in Portuguese) or pain be the main symptom of the condition represented by the respective ICD. We selected only ICDs used in at least five admissions in 2021 (January to December), independent of readmission of the same patient. Results There were 71,267 consultations in 2021 using 2,296 different ICDs. Of these, the Headache (CEFALEIA) ICD was the 7th most frequent (n= 2,121) behind the following ICDs: Unspecified viral infection (n= 4,327); Influenza with other respiratory manifestations, due to unidentified virus (n= 3,335); Respiratory infection by the new coronavirus (Covid-19) (n= 2,927); Low back pain (n=2,759) and Diarrhea and gastroenteritis of presumptive infectious origin (n=2,739). In 27,853/71,267 (39.1%), the consultations were related to pain in any part of the body (with 258 ICDs). In the group of patients with pain of traumatological, orthopedic, or rheumatic origin, there were 10,148 consultations (142 ICDs); Abdominal or pelvic pain (5,675, with 23 DICs); Spinal pain (3,805, with 10 ICDs); and Chest pain, including coronary ischemia (1,786, with 10 ICDs)... (To see the complet abstract, please, check out the PDF.)

Systematic assessment of template-based genome-scale metabolic models created with the BiGG Integration Tool

Genome-scale metabolic models (GEMs) are essential tools for in silico phenotype prediction and strain optimisation. The most straightforward GEMs reconstruction approach uses published models as templates to generate the initial draft, requiring further curation. Such an approach is used by BiGG Integration Tool (BIT), available for merlin users. This tool uses models from BiGG Models database as templates for the draft models. Moreover, BIT allows the selection between different template combinations. The main objective of this study is to assess the draft models generated using this tool and compare them BIT, comparing these to CarveMe models, both of which use the BiGG database, and curated models. For this, three organisms were selected, namely Streptococcus thermophilus, Xylella fastidiosa and Mycobacterium tuberculosis. The models’ variability was assessed using reactions and genes’ metabolic functions. This study concluded that models generated with BIT for each organism were differentiated, despite sharing a significant portion of metabolic functions. Furthermore, the template seems to influence the content of the models, though to a lower extent. When comparing each draft with curated models, BIT had better performances than CarveMe in all metrics. Hence, BIT can be considered a fast and reliable alternative for draft reconstruction for bacteria models.

P-386 Serum P levels measured on the day of embryo transfer in FET modified natural cycles are not related to pregnancy outcome

Study question

Is there an optimal serum progesterone (P) threshold in frozen embryo transfer (FET) modified natural cycles when luteal phase support (LPS) is given?

Summary answer

Serum P measured on the day of ET is not related with ongoing pregnancy outcome when doing a modified natural cycle with LPS.

What is known already

Recent publications showed that there is a minimum threshold of serum P that needs to be reached in artificial cycles to optimize pregnancy rates. When using micronized vaginal P (MVP), about 30% of patients show low levels of serum P (<9 ng/mL) leading to a significant decrease in ongoing pregnancy; although this situation can be reverted by increasing and modifying the route of exogenous P. In pure natural cycles without LPS, serum P below 10 ng/mL impairs pregnancy outcome. Nevertheless, there is no data about the impact of serum P levels in modified natural cycles in which LPS is given.

Study design, size, duration

Prospective cohort unicentric study performed in IVI RMA Valencia (Spain), including 244 cycles from February 2020 to January 2021.

Participants/materials, setting, methods

Infertile patients <50 y.o. and BMI<40Kg/m2 undergoing a FET of a maximum of 2 blastocysts, from own or donated oocytes. FET were performed in the context of a modified natural cycle (single injection of rec-hCG when dominant follicle reached 17mm and endometrial thickness >6.5mm). MVP was used for LPS (200mg/12h). Ongoing pregnancy rate (OPR) was correlated with serum P levels on the FET day, measured within two hours before transfer.

Main results and the role of chance

A total of 241 patients were analyzed. Mean age was 38.1 + 3.8 years, with a mean BMI of 23.3 + 3.9. On the rec-hCG day the mean leading follicle size was 17.7±0.1 mm. The endometrium displayed a trilaminar pattern, with a mean thickness of 7.8±3.3 mm, and mean P and estradiol (E2) levels were 0.30±0.03 ng/ml and 249.39±11.03  pg/ml, respectively. A mean of 1.1 blastocysts were transferred (90.9% were single embryo transfers), 27.4% (66) from donated and 72.6 % (175) from own oocytes. On the day of FET, the mean serum P and E2 levels were 26.19 + 8.97ng/mL and 154.12 + 96.08pg/mL, respectively. The overall OPR was 51.5% (124). OPR according to quartiles of serum P (ng/mL) was 56.7% (Q1, P < 20.2), 47.5% (Q2, P > 20.2-24.8), 51.7% (Q3, P > 24.8-31.1), 50.0% (Q4, P > 31.1), p = 0.78). Multivariate logistic regression showed that serum P was not related with OPR after adjusting for age, BMI, E2 and origin of oocytes (aOR:0.98, 95% CI:0.93-1.04, p = 0.47). Only 2 patients had serum P levels below 10 ng/mL, with values of 8.6 and 8.8 ng/mL on the ET day and had a negative pregnancy test.

Limitations, reasons for caution

As part of our routine clinical practice, MVP (200mg/12h) is given for LPS in patients undergoing a FET in the context of a modified natural cycle. Thus, these results cannot be extrapolated to LPS-free or any other LPS protocol in FET modified natural cycles.

Wider implications of the findings

The majority of patients undergoing FET in modified natural cycles when using LPS have adequate levels of serum P and thus, do not have an impact on pregnancy outcome. According to our data, there is no need to measure serum P levels on the luteal phase of modified natural cycles.

Trial registration number

NCT04259996

P-365 Lesbian Shared IVF (ROPA) and IVF with donated semen – changing the recipient has no impact on reproductive outcomes

Study question

Are ROPA outcomes different from IVF with donated semen? – does the absence of genetic links between embryo and uterus impact reproductive outcomes?

Summary answer

The ROPA method has similar reproductive success rates to conventional IVF with donated semen.

What is known already

ROPA (reception of oocytes from partner), also known as lesbian shared IVF, is an assisted reproduction technique for female couples in which one woman provides the oocytes and the other receives the embryos, allowing both women to share biological motherhood. This technique may also be a way to assess the reproductive impact of the absence of a genetic link between the pregnant woman and the embryo. Broadly, it is an oocyte donation treatment, with the particularity that the patient’s partner is the donor. In practice, this means that the donor may not be as young, healthy and fertile as usual.

Study design, size, duration

Retrospective multicentric cohort study performed from January 2011 to December 2020 in 18 fertility clinics in Spain. A total of 99 ROPA (73 couples) and 2929 IVF cycles (2334 couples) were included.

Participants/materials, setting, methods

ROPA and IVF cycles with donated semen of women younger than 38 years old and no know female fertility disorder were included. Clinical outcomes were compared between both groups, including positive pregnancy test, clinical pregnancy, miscarriage, ectopic pregnancy, preterm birth and live birth rates and weeks of gestation and newborn weight at birth.

Main results and the role of chance

No differences were found between groups in clinical outcomes, including positive pregnancy test, clinical pregnancy, miscarriage, ectopic pregnancy and live birth rates, neither with fresh nor frozen embryo transfers. In addition, there were no differences in gestational age at birth, preterm birth rate or newborn weight. The total clinical pregnancy rates per embryo transfer were 57% and 50.2% (p = 0.15) and the live birth rates were 46.1% and 40.9% (p = 0.14) for the ROPA and IVF groups, respectively. When adjusted to age and BMI of donors and recipients, there were also no differences in live birth rates between both groups. The cumulative live birth rate per ROPA cycle was 73.7% and the cumulative live birth rate per couple was 78.3%.

Limitations, reasons for caution

The retrospective nature of the study, the small sample size of the ROPA group, differences in age between both groups, the possibility of unknown other previous reproductive treatments, and the no analysis of obstetric and other neonatal complications and outcomes.

Wider implications of the findings

Clinical outcomes of ROPA and single way IVF were similar, both after fresh and frozen embryo transfers. These findings suggest no impact of the absence of genetic ties between the embryo and the uterus on reproductive treatments’ outcomes. Data regarding the outcomes of the ROPA method are reassuring.

Trial registration number

2011-VLC-093-PB

merlin, an improved framework for the reconstruction of high-quality genome-scale metabolic models

Genome-scale metabolic models have been recognised as useful tools for better understanding living organisms' metabolism. merlin (https://www.merlin-sysbio.org/) is an open-source and user-friendly resource that hastens the models' reconstruction process, conjugating manual and automatic procedures, while leveraging the user's expertise with a curation-oriented graphical interface. An updated and redesigned version of merlin is herein presented. Since 2015, several features have been implemented in merlin, along with deep changes in the software architecture, operational flow, and graphical interface. The current version (4.0) includes the implementation of novel algorithms and third-party tools for genome functional annotation, draft assembly, model refinement, and curation. Such updates increased the user base, resulting in multiple published works, including genome metabolic (re-)annotations and model reconstructions of multiple (lower and higher) eukaryotes and prokaryotes. merlin version 4.0 is the only tool able to perform template based and de novo draft reconstructions, while achieving competitive performance compared to state-of-the art tools both for well and less-studied organisms.

Chromosome-level assembly, annotation and phylome of Pelobates cultripes, the western spadefoot toad

Genomic resources for amphibians are still hugely under-represented in vertebrate genomic research, despite being a group of major interest for ecology, evolution and conservation. Amphibians constitute a highly threatened group of vertebrates, present a vast diversity in reproductive modes, are extremely diverse in morphology, occupy most ecoregions of the world, and present the widest range in genome sizes of any major group of vertebrates. We combined Illumina, Nanopore and Hi-C sequencing technologies to assemble a chromosome-level genome sequence for an anuran with a moderate genome size (assembly span 3.09 Gb); Pelobates cultripes, the western spadefoot toad. The genome has an N50 length of 330 Mb with 98.6% of the total sequence length assembled into 14 super scaffolds, and 87.7% complete BUSCO genes. We use published transcriptomic data to provide annotations, identifying 32,684 protein-coding genes. We also reconstruct the P. cultripes phylome and identify 2,527 gene expansions. We contribute the first draft of the genome of the western spadefoot toad, P. cultripes. This species represents a relatively basal lineage in the anuran tree with an interesting ecology and a high degree of developmental plasticity, and thus is an important resource for amphibian genomic research.

Emergence of 16S rRNA methyltransferases among carbapenemase-producing Enterobacterales in Spain studied by whole-genome sequencing

The emergence of 16S rRNA methyltransferases (RMTs) in Gram-negative pathogens bearing other clinically relevant resistance mechanisms, such as carbapenemase-producing Enterobacterales (CPE), is becoming an alarming concern. We investigated the prevalence, antimicrobial susceptibility, resistance mechanisms, molecular epidemiology and genetic support of RMTs in CPE isolates from Spain. This study included a collection of 468 CPE isolates recovered during 2018 from 32 participating Spanish hospitals. MICs were determined using the broth microdilution method, the agar dilution method (fosfomycin) or MIC gradient strips (plazomicin). All isolates were subjected to hybrid whole-genome sequencing (WGS). Sequence types (STs), core genome phylogenetic relatedness, horizontally acquired resistance mechanisms, plasmid analysis and the genetic environment of RMTs were determined in silico from WGS data in all RMT-positive isolates. Among the 468 CPE isolates evaluated, 24 isolates (5.1%) recovered from nine different hospitals spanning five Spanish regions showed resistance to all aminoglycosides and were positive for an RMT (21 RmtF, 2 ArmA and 1 RmtC). All RMT-producers showed high-level resistance to all aminoglycosides, including plazomicin, and in most cases exhibited an extensively drug-resistant susceptibility profile. The RMT-positive isolates showed low genetic diversity and were global clones of Klebsiella pneumoniae (ST147, ST101, ST395) and Enterobacter cloacae (ST93) bearing bla_OXA-48, bla_NDM-1 or bla_VIM-1 carbapenemase genes. RMTs were harboured in five different multidrug resistance plasmids and linked to efficient mobile genetic elements. Our findings highlight that RMTs are emerging among clinical CPE isolates from Spain and their spread should be monitored to preserve the future clinical utility of aminoglycosides and plazomicin.

Kinetic instability in inductively oscillatory plasma equilibrium

A uniform in space, oscillatory in time plasma equilibrium sustained by a time-dependent current density is analytically and numerically studied resorting to particle-in-cell simulations. The dispersion relation is derived from the Vlasov equation for oscillating equilibrium distribution functions, and used to demonstrate that the plasma has an infinite number of unstable kinetic modes. This instability represents a kinetic mechanism for the decay of the initial mode of infinite wavelength (or equivalently null wave number), for which no classical wave breaking or Landau damping exists. The relativistic generalization of the instability is discussed. In this regime, the growth rate of the fastest growing unstable modes scales with γ_{T}^{-1/2}, where γ_{T} is the largest Lorentz factor of the plasma distribution. This result hints that this instability is not as severely suppressed for large Lorentz factor flows as purely streaming instabilities. The relevance of this instability in inductive electric field oscillations driven in pulsar magnetospheres is discussed.

Combining Nanopore and Illumina Sequencing Permits Detailed Analysis of Insertion Mutations and Structural Variations Produced by PEG-Mediated Transformation in Ostreococcus tauri

Ostreococcus tauri is a simple unicellular green alga representing an ecologically important group of phytoplankton in oceans worldwide. Modern molecular techniques must be developed in order to understand the mechanisms that permit adaptation of microalgae to their environment. We present for the first time in O. tauri a detailed characterization of individual genomic integration events of foreign DNA of plasmid origin after PEG-mediated transformation. Vector integration occurred randomly at a single locus in the genome and mainly as a single copy. Thus, we confirmed the utility of this technique for insertional mutagenesis. While the mechanism of double-stranded DNA repair in the O. tauri model remains to be elucidated, we clearly demonstrate by genome resequencing that the integration of the vector leads to frequent structural variations (deletions/insertions and duplications) and some chromosomal rearrangements in the genome at the insertion loci. Furthermore, we often observed variations in the vector sequence itself. From these observations, we speculate that a nonhomologous end-joining-like mechanism is employed during random insertion events, as described in plants and other freshwater algal models. PEG-mediated transformation is therefore a promising molecular biology tool, not only for functional genomic studies, but also for biotechnological research in this ecologically important marine alga.

MEWpy: A Computational Strain Optimization Workbench in Python

Summary

Metabolic Engineering aims to favour the overproduction of native, as well as non-native, metabolites by modifying or extending the cellular processes of a specific organism. In this context, Computational Strain Optimization (CSO) plays a relevant role by putting forward mathematical approaches able to identify potential metabolic modifications to achieve the defined production goals. We present MEWpy, a Python workbench for metabolic engineering, which covers a wide range of metabolic and regulatory modelling approaches, as well as phenotype simulation and CSO algorithms.

Availability and implementation

MEWpy can be installed from PyPi (pip install mewpy), the source code being available at https://github.com/BioSystemsUM/mewpy under the GPL license.

Massive gene presence-absence variation shapes an open pan-genome in the Mediterranean mussel

BACKGROUND

The Mediterranean mussel Mytilus galloprovincialis is an ecologically and economically relevant edible marine bivalve, highly invasive and resilient to biotic and abiotic stressors causing recurrent massive mortalities in other bivalves. Although these traits have been recently linked with the maintenance of a high genetic variation within natural populations, the factors underlying the evolutionary success of this species remain unclear.

RESULTS

Here, after the assembly of a 1.28-Gb reference genome and the resequencing of 14 individuals from two independent populations, we reveal a complex pan-genomic architecture in M. galloprovincialis, with a core set of 45,000 genes plus a strikingly high number of dispensable genes (20,000) subject to presence-absence variation, which may be entirely missing in several individuals. We show that dispensable genes are associated with hemizygous genomic regions affected by structural variants, which overall account for nearly 580 Mb of DNA sequence not included in the reference genome assembly. As such, this is the first study to report the widespread occurrence of gene presence-absence variation at a whole-genome scale in the animal kingdom.

CONCLUSIONS

Dispensable genes usually belong to young and recently expanded gene families enriched in survival functions, which might be the key to explain the resilience and invasiveness of this species. This unique pan-genome architecture is characterized by dispensable genes in accessory genomic regions that exceed by orders of magnitude those observed in other metazoans, including humans, and closely mirror the open pan-genomes found in prokaryotes and in a few non-metazoan eukaryotes.

Novel insights on Andersen-Tawil syndrome type 1

Background

Andersen-Tawil Syndrome type 1 (ATS1) in a rare arrhythmogenic disease caused by loss-of-function mutations in the KCNJ2 gene and characterized by ventricular arrhythmias, dysmorphic features and episodes of periodic paralysis. Although the prognosis of ATS1 patients is typically considered benign, definitive outcome data are lacking.

Purpose

We aimed to: 1) define the risk of life-threatening arrhythmic events (LAEs); 2) identify risk factors for such events; 3) assess the efficacy of anti-arrhythmic drugs in preventing LAEs.

Methods

We included 118 ATS1 patients from 57 families with confirmed pathogenic or likely pathogenic KCNJ2 mutations. Clinical and genetical data were acquired by investigators from 23 centers in 9 countries.

Results

Baseline characteristics of the population are presented in the Table. Over a follow-up of 6.2 years, 17/118 (14%) patients experienced a first LAE, with a 5-year cumulative probability of 7.9% (Figure). Cox multivariable analysis demonstrated that a previous history of syncope (HR 4.5, p=0.02), the documentation of sustained VT (HR 9.3, p=0.001) and the administration of amiodarone (HR 268, p<0.001) were associated with an increased risk of LAE. The baseline rate of LAE was not reduced by beta-blockers alone (1.37 per 100 py; p=1), or in combination with class Ic antiarrhythmic drugs (1.46 per 100 py, p=1).

Conclusions

Our data demonstrate that the clinical course of patients with ATS1 is characterized by a high rate of LAE. A history of unexplained syncope, and documentation of sustained ventricular tachycardia are independently associated with a higher risk of LAE. Amiodarone is proarrhythmic and should be avoided in ATS1 patients.

ATS1: Diagnosis, Outcome, Risk Factors

Funding Acknowledgement

Type of funding source: Public grant(s) – EU funding. Main funding source(s): ERN Guard-Heart European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart

Genomic evidence for recurrent genetic admixture during the domestication of Mediterranean olive trees (Olea europaea L.)

BACKGROUND

Olive tree (Olea europaea L. subsp. europaea, Oleaceae) has been the most emblematic perennial crop for Mediterranean countries since its domestication around 6000 years ago in the Levant. Two taxonomic varieties are currently recognized: cultivated (var. europaea) and wild (var. sylvestris) trees. However, it remains unclear whether olive cultivars derive from a single initial domestication event followed by secondary diversification, or whether cultivated lineages are the result of more than a single, independent primary domestication event. To shed light into the recent evolution and domestication of the olive tree, here we analyze a group of newly sequenced and available genomes using a phylogenomics and population genomics framework.

RESULTS

We improved the assembly and annotation of the reference genome, newly sequenced the genomes of twelve individuals: ten var. europaea, one var. sylvestris, and one outgroup taxon (subsp. cuspidata)-and assembled a dataset comprising whole genome data from 46 var. europaea and 10 var. sylvestris. Phylogenomic and population structure analyses support a continuous process of olive tree domestication, involving a major domestication event, followed by recurrent independent genetic admixture events with wild populations across the Mediterranean Basin. Cultivated olives exhibit only slightly lower levels of genetic diversity than wild forms, which can be partially explained by the occurrence of a mild population bottleneck 3000-14,000 years ago during the primary domestication period, followed by recurrent introgression from wild populations. Genes associated with stress response and developmental processes were positively selected in cultivars, but we did not find evidence that genes involved in fruit size or oil content were under positive selection. This suggests that complex selective processes other than directional selection of a few genes are in place.

CONCLUSIONS

Altogether, our results suggest that a primary domestication area in the eastern Mediterranean basin was followed by numerous secondary events across most countries of southern Europe and northern Africa, often involving genetic admixture with genetically rich wild populations, particularly from the western Mediterranean Basin.

Return to Play After a Lateral Ligament Ankle Sprain

Purpose of Review

The purpose of this review is to describe the current evidence on the most common sports-related ankle injuries. Joint anatomy, epidemiology, clinical findings, diagnostic approach, and treatment are presented with a specific focus on the available evidence towards return to play.

Recent Findings

Recent findings show that ankle sprain is the most common injury in the world of sports. Bony fractures, cartilage defects, and syndesmotic lesions are frequently seen in association with the more severe type of ankle sprains.

Summary

In summary, the majority of the athletes’ ankle sprains are managed conservatively with excellent outcomes and full return to their pre-injury level of play. However, it is essential to differentiate the single ligament sprain from a more complex injury to the ankle joint. The evidence-based treatment and rehabilitation programmes are associated with a better prognosis and a faster time to return to sport participation.

Phylogenomics Identifies an Ancestral Burst of Gene Duplications Predating the Diversification of Aphidomorpha

Aphids (Aphidoidea) are a diverse group of hemipteran insects that feed on plant phloem sap. A common finding in studies of aphid genomes is the presence of a large number of duplicated genes. However, when these duplications occurred remains unclear, partly due to the high relatedness of sequenced species. To better understand the origin of aphid duplications we sequenced and assembled the genome of Cinara cedri, an early branching lineage (Lachninae) of the Aphididae family. We performed a phylogenomic comparison of this genome with 20 other sequenced genomes, including the available genomes of five other aphids, along with the transcriptomes of two species belonging to Adelgidae (a closely related clade to the aphids) and Coccoidea. We found that gene duplication has been pervasive throughout the evolution of aphids, including many parallel waves of recent, species-specific duplications. Most notably, we identified a consistent set of very ancestral duplications, originating from a large-scale gene duplication predating the diversification of Aphidomorpha (comprising aphids, phylloxerids, and adelgids). Genes duplicated in this ancestral wave are enriched in functions related to traits shared by Aphidomorpha, such as association with endosymbionts, and adaptation to plant defenses and phloem-sap-based diet. The ancestral nature of this duplication wave (106-227 Ma) and the lack of sufficiently conserved synteny make it difficult to conclude whether it originated from a whole-genome duplication event or, alternatively, from a burst of large-scale segmental duplications. Genome sequencing of other aphid species belonging to different Aphidomorpha and related lineages may clarify these findings.

Administración y preparación de antimicrobianos en una unidad chilena de cuidados neonatales

Objetivo: Describir la preparación, administración y monitorización de los antimicrobianos utilizados en una Unidad de Cuidados Neonatales en Santiago de Chile. Métodos: Estudio descriptivo. Se realizó la aplicación de un instrumento a 20 matronas de neonatología de una Unidad Chilena de Cuidados Neonatales (UCHCN) en 2018, para recopilar información respecto a once variables en la preparación y administración de antimicrobianos. El estudio abarcó tres variables principales: preparación, mantención y monitorización de los antimicrobianos. Resultados: Se recopiló información de 14 antimicrobianos, de los cuales la presentación del 92.8% de ellos era inyectable y el 78.2% de los encuestados reconocía el valor de la unidad de dosificación del medicamento. Mantención 85.7% de los antimicrobianos son eliminados luego de su preparación. Para dilución se utiliza mayormente la solución fisiológica en un 76.9% de los casos y el volumen utilizado de diluyente y concentración final varió según cada medicamento. Un 92.8% de los antimicrobianos se administra por vía endovenosa y todos a través de una bomba de jeringa. Monitorización específica de la administración sólo se realiza en un 7.2% de ellos. Conclusiones: Debido a las variabilidades encontradas en los procesos de mantención, dilución y monitorización es que se propone la creación o el mejoramiento y difusión de protocolos locales, para evitar efectos adversos o complicaciones y así resguardar la seguridad de los pacientes.

Transposons played a major role in the diversification between the closely related almond and peach genomes: results from the almond genome sequence

We sequenced the genome of the highly heterozygous almond Prunus dulcis cv. Texas combining short- and long-read sequencing. We obtained a genome assembly totaling 227.6 Mb of the estimated almond genome size of 238 Mb, of which 91% is anchored to eight pseudomolecules corresponding to its haploid chromosome complement, and annotated 27 969 protein-coding genes and 6747 non-coding transcripts. By phylogenomic comparison with the genomes of 16 additional close and distant species we estimated that almond and peach (Prunus persica) diverged around 5.88 million years ago. These two genomes are highly syntenic and show a high degree of sequence conservation (20 nucleotide substitutions per kb). However, they also exhibit a high number of presence/absence variants, many attributable to the movement of transposable elements (TEs). Transposable elements have generated an important number of presence/absence variants between almond and peach, and we show that the recent history of TE movement seems markedly different between them. Transposable elements may also be at the origin of important phenotypic differences between both species, and in particular for the sweet kernel phenotype, a key agronomic and domestication character for almond. Here we show that in sweet almond cultivars, highly methylated TE insertions surround a gene involved in the biosynthesis of amygdalin, whose reduced expression has been correlated with the sweet almond phenotype. Altogether, our results suggest a key role of TEs in the recent history and diversification of almond and its close relative peach.

Multi-institutional experience of genetic diagnosis in Ecuador: National registry of chromosome alterations and polymorphisms

BACKGROUND

Detection of chromosomal abnormalities is crucial in various medical areas; to diagnose birth defects, genetic disorders, and infertility, among other complex phenotypes, in individuals across a wide range of ages. Hence, the present study wants to contribute to the knowledge of type and frequency of chromosomal alterations and polymorphisms in Ecuador.

METHODS

Cytogenetic registers from different Ecuadorian provinces have been merged and analyzed to construct an open-access national registry of chromosome alterations and polymorphisms.

RESULTS

Of 28,806 karyotypes analyzed, 6,008 (20.9%) exhibited alterations. Down syndrome was the most frequent autosome alteration (88.28%), followed by Turner syndrome (60.50%), a gonosome aneuploidy. A recurrent high percentage of Down syndrome mosaicism (7.45%) reported here, as well as by previous Ecuadorian preliminary registries, could be associated with geographic location and admixed ancestral composition. Translocations (2.46%) and polymorphisms (7.84%) were not as numerous as autosomopathies (64.33%) and gonosomopathies (25.37%). Complementary to conventional cytogenetics tests, molecular tools have allowed identification of submicroscopic alterations regions or candidate genes which can be possibly implicated in patients' symptoms and phenotypes.

CONCLUSION

The Ecuadorian National Registry of Chromosome Alterations and Polymorphisms provides a baseline to better understand chromosomal abnormalities in Ecuador and therefore their clinical management and awareness. This data will guide public policy makers to promote and financially support cytogenetic and genetic testing.

Chronic Distal Radioulnar Joint Dislocation: A Case Report

Dislocation of the distal radioulnar joint (DRUJ) usually occurs associated with a distal radius fracture. An isolated dislocation, without a radius fracture, is a rare situation.

We present a case of neglected isolated DRUJ dislocation in a 30-year-old manual laborer. The treatment was performed 4 months after the initial injury. Open reduction and fixation were performed. This resulted in a stable, pain-free joint, and the patient resumed his previous work.

Surgical techniques of foveal reattachment and dorsal capsuloplasty have been described for chronic DRUJ instability. An isolated and dislocated DRUJ is an uncommon injury that may be misdiagnosed and initially mistreated. There haven't been many reports in the literature of a case such as this.

SamPler - a novel method for selecting parameters for gene functional annotation routines

BACKGROUND

As genome sequencing projects grow rapidly, the diversity of organisms with recently assembled genome sequences peaks at an unprecedented scale, thereby highlighting the need to make gene functional annotations fast and efficient. However, the (high) quality of such annotations must be guaranteed, as this is the first indicator of the genomic potential of every organism. Automatic procedures help accelerating the annotation process, though decreasing the confidence and reliability of the outcomes. Manually curating a genome-wide annotation of genes, enzymes and transporter proteins function is a highly time-consuming, tedious and impractical task, even for the most proficient curator. Hence, a semi-automated procedure, which balances the two approaches, will increase the reliability of the annotation, while speeding up the process. In fact, a prior analysis of the annotation algorithm may leverage its performance, by manipulating its parameters, hastening the downstream processing and the manual curation of assigning functions to genes encoding proteins.

RESULTS

Here SamPler, a novel strategy to select parameters for gene functional annotation routines is presented. This semi-automated method is based on the manual curation of a randomly selected set of genes/proteins. Then, in a multi-dimensional array, this sample is used to assess the automatic annotations for all possible combinations of the algorithm's parameters. These assessments allow creating an array of confusion matrices, for which several metrics are calculated (accuracy, precision and negative predictive value) and used to reach optimal values for the parameters.

CONCLUSIONS

The potential of this methodology is demonstrated with four genome functional annotations performed in merlin, an in-house user-friendly computational framework for genome-scale metabolic annotation and model reconstruction. For that, SamPler was implemented as a new plugin for the merlin tool.

Adjustable transobturator male system (ATOMS®) as treatment of stress urinary incontinence secondary to transurethral resection of the prostate

OBJECTIVES

Feasibility study to evaluate efficacy and safety of Adjustable Transobturator Male System (ATOMS^®) for male stress urinary incontinence (SUI) after transurethral resection of the prostate.

MATERIALS AND METHODS

Twenty patients were implanted ATOMS^® for SUI caused by transurethral resection of the prostate with or without radiotherapy. Incontinence severity was evaluated as mild (2 pads/day), moderate (3-5 pads/day) or severe (≥6pads/day), and dryness as none or one security pad/day. Changes in pad-test and pad-count after adjustment were investigated, together with operative parameters, patient satisfaction with the procedure, and number and grade of complications (Clavien-Dindo).

RESULTS

Median age was 76.5years. Five patients received previous pelvic radiation (3 prostate, 2 rectal cancer) and 2 (10%) previous failed artificial urinary sphincter with urethral erosion and mechanical failure, respectively. Preoperative SUI was mild in 4 (20%), moderate in 7 (35%) and severe in 9 (45%). Median filling of the system was 13.5ml. Median pad-test decreased from 375±855ml baseline to 10±31.5ml and pad-count from 4±3 to 0±1.5 after adjustment (1±3fillings). Postoperative SUI distribution was mild in 2 (10%), moderate in one (5%) and severe in 2 (10%). Satisfaction rate was 80%, equal for transurethral resection of the prostate with/without previous radiotherapy. No patient had urinary retention after catheter removal. Complications presented in 3 (15%) patients, all minor. After median 38.5mo follow-up no system has been removed, 19 (95%) self-considered better than before and 11 (55%) very much better.

CONCLUSION

Based on short-term efficacy and patient satisfaction ATOMS^® can be considered a realistic alternative for SUI after transurethral resection of the prostate, even after irradiation. Absence of urethral erosion and very limited problems make this alternative especially attractive for cases with diminished dexterity, advanced age and previous failed treatments.

The High-Quality Genome Sequence of the Oceanic Island Endemic Species Drosophila guanche Reveals Signals of Adaptive Evolution in Genes Related to Flight and Genome Stability

Drosophila guanche is a member of the obscura group that originated in the Canary Islands archipelago upon its colonization by D. subobscura. It evolved into a new species in the laurisilva, a laurel forest present in wet regions that in the islands have only minor long-term weather fluctuations. Oceanic island endemic species such as D. guanche can become model species to investigate not only the relative role of drift and adaptation in speciation processes but also how population size affects nucleotide variation. Moreover, the previous identification of two satellite DNAs in D. guanche makes this species attractive for studying how centromeric DNA evolves. As a prerequisite for its establishment as a model species suitable to address all these questions, we generated a high-quality D. guanche genome sequence composed of 42 cytologically mapped scaffolds, which are assembled into six super-scaffolds (one per chromosome). The comparative analysis of the D. guanche proteome with that of twelve other Drosophila species identified 151 genes that were subject to adaptive evolution in the D. guanche lineage, with a subset of them being involved in flight and genome stability. For example, the Centromere Identifier (CID) protein, directly interacting with centromeric satellite DNA, shows signals of adaptation in this species. Both genomic analyses and FISH of the two satellites would support an ongoing replacement of centromeric satellite DNA in D. guanche.

Lateral Approach to the Maxillary Sinus and Mandibular Canal in Severely Atrophied Posterior Alveolar Bone

PURPOSE

To present a technique to rehabilitate atrophied alveolar ridges in the posterior maxilla and mandible using bone lateral to the maxillary sinus and to the inferior alveolar nerve and to present a retrospective study of the technique.

MATERIALS AND METHODS

Severe resorption of the posterior region of the maxilla and mandible was treated following a conservative approach. Patients who presented this bone crest condition that impeded the placement of implants and had an anatomy that allowed the inferior alveolar nerve or the maxillary sinus to be approached laterally were treated. The bone ridge thickness lateral to the maxillary sinus and the inferior alveolar nerve was measured by computed tomography, and implants with a wedge-shaped design were placed in the available bone. A retrospective review of clinical records of these patients, treated between 1998 and 2012 at the Clinest - Clinical Center of Research in Stomatology, was conducted. The studied variables were surgical and prosthetic complications, the implant survival rate, and the difference between the remaining bone ridge measurement in the ridge center and the implant length placed laterally.

RESULTS

Fifty-six patients met the inclusion criteria. These patients received 208 implants according to the aforementioned technique. The mean implant length gain was 6.9 mm, varying from 0.5 to 12 mm. The cumulative survival rate was high for both maxillaries. For the implants placed beside the inferior alveolar nerve, none were lost at 2 years, two were lost at 5 years, and four were lost at 10 years. For the implants placed beside the maxillary sinus, only four implants were lost at 10 years. Nerve injuries and surgical/prosthetic complications occurred but were not significant.

CONCLUSION

The use of available bone alongside the maxillary sinus and inferior alveolar nerve to place implants is a surgical possibility, and a predictable, safe approach, albeit delicate and experience-dependent.

Is the adjustable transobturator system ATOMS® useful for the treatment of male urinary incontinence in low to medium volume urological centers?

INTRODUCTION

Urinary incontinence (UI) is a complication of radical prostatectomy (RP) and transurethral resection of the prostate (TURP). The gold-standard treatment is the artificial urinary sphincter, however, new treatments have been investigated.

OBJECTIVE

To examine the outcome of an adjustable transobturator male system (ATOMS^®) in men with UI after prostatic surgery in a low to medium volume continence center.

MATERIALS AND METHODS

Twenty-five men with UI were implanted with ATOMS^® system between 2012 and 2014. The most common indication was UI after RP (92%), followed by UI after TURP (8%). Eleven patients (44%) had received adjuvant external beam radiotherapy (RT). Patients were considered to be 'dry' if they stopped wearing pads or needed just one protective pad per day; and improved if the daily number of pads used decreased by at least half. The Incontinence Quality of Life questionnaire (ICIQ-SF) was used, adding a verbal question about the satisfaction of the patient considering the outcome.

RESULTS

After a mean follow-up of 21.56 months, 64% were dry and 8% revealed a significant improvement. The success of the procedure was negatively correlated with the severity of the previous UI and with previous treatment with RT. Concerning patients satisfaction, 84% of the patients would repeat the procedure.

CONCLUSION

ATOMS^® offers good rates of cure and improvement of UI after prostatic surgery with a reasonable rate of minor complications. The results of this study, performed in a low to medium volume continence center, are comparable to the results achieved in high volume continence centers.

Association between CFH, CFB, ARMS2, SERPINF1, VEGFR1 and VEGF polymorphisms and anatomical and functional response to ranibizumab treatment in neovascular age-related macular degeneration

PURPOSE

We sought to determine if specific genetic single nucleotide polymorphisms (SNPs) influence vascular endothelial growth factor inhibition response to ranibizumab in neovascular age-related macular degeneration (AMD).

METHODS

A total of 403 Caucasian patients diagnosed with exudative AMD were included. After a three-injection loading phase, a pro re nata regimen was followed. Nine SNPs from six different genes (CFH, CFB, ARMS2, SERPINF1, VEGFR1, VEGF) were genotyped. Non-genetic risk factors (gender, smoking habit and hypertension) were also assessed. Patients were classified as good or poor responders (GR or PR) according to functional (visual acuity), anatomical (foveal thickness measured by OCT) and fluid criteria (fluid/no fluid measured by OCT).

RESULTS

Hypertension was the environmental factor with the strongest poor response association with ranibizumab in the anatomical measure after the loading phase (p = 0.0004; OR 3.7; 95% CI, 2.4-5.8) and after 12 months of treatment (p = 10^-5 ; OR 2.3; 95% CI, 1.5-3.4). The genetic variants rs12614 (CFB), rs699947 (VEGFA) and rs7993418 (VEGFR1) predisposed patients to a good response, while rs12603486 and rs1136287 (SERPINF1) were associated with a poor response. The protective genotype of rs800292 variant (CFH) was also associated with a poor anatomical response (p 0.0048).

CONCLUSION

All these data suggest that genetics play an important role in treatment response in AMD patients.

Sitagliptin improved glucose assimilation in detriment of fatty-acid utilization in experimental type-II diabetes: role of GLP-1 isoforms in Glut4 receptor trafficking

BACKGROUND

The distribution of glucose and fatty-acid transporters in the heart is crucial for energy consecution and myocardial function. In this sense, the glucagon-like peptide-1 (GLP-1) enhancer, sitagliptin, improves glucose homeostasis but it could also trigger direct cardioprotective actions, including regulation of energy substrate utilization.

METHODS

Type-II diabetic GK (Goto-Kakizaki), sitagliptin-treated GK (10 mg/kg/day) and wistar rats (n = 10, each) underwent echocardiographic evaluation, and positron emission tomography scanning for [¹⁸F]-2-fluoro-2-deoxy-D-glucose (¹⁸FDG). Hearts and plasma were isolated for biochemical approaches. Cultured cardiomyocytes were examined for receptor distribution after incretin stimulation in high fatty acid or high glucose media.

RESULTS

Untreated GK rats exhibited hyperglycemia, hyperlipidemia, insulin resistance, and plasma GLP-1 reduction. Moreover, GK myocardium decreased ¹⁸FDG assimilation and diastolic dysfunction. However, sitagliptin improved hyperglycemia, insulin resistance, and GLP-1 levels, and additionally, enhanced ¹⁸FDG uptake and diastolic function. Sitagliptin also stimulated the sarcolemmal translocation of the glucose transporter-4 (Glut4), in detriment of the fatty acyl translocase (FAT)/CD36. In fact, Glut4 mRNA expression and sarcolemmal translocation were also increased after GLP-1 stimulation in high-fatty acid incubated cardiomyocytes. PI3K/Akt and AMPKα were involved in this response. Intriguingly, the GLP-1 degradation metabolite, GLP-1(9-36), showed similar effects.

CONCLUSIONS

Besides of its anti-hyperglycemic effect, sitagliptin-enhanced GLP-1 may ameliorate diastolic dysfunction in type-II diabetes by shifting fatty acid to glucose utilization in the cardiomyocyte, and thus, improving cardiac efficiency and reducing lipolysis.