The genetic landscape of mitochondrial diseases in the next-generation sequencing era: a Portuguese cohort study

Introduction: Rare disorders that are genetically and clinically heterogeneous, such as mitochondrial diseases (MDs), have a challenging diagnosis. Nuclear genes codify most proteins involved in mitochondrial biogenesis, despite all mitochondria having their own DNA. The development of next-generation sequencing (NGS) technologies has revolutionized the understanding of many genes involved in the pathogenesis of MDs. In this new genetic era, using the NGS approach, we aimed to identify the genetic etiology for a suspected MD in a cohort of 450 Portuguese patients. Methods: We examined 450 patients using a combined NGS strategy, starting with the analysis of a targeted mitochondrial panel of 213 nuclear genes, and then proceeding to analyze the whole mitochondrial DNA. Results and Discussion: In this study, we identified disease-related variants in 134 (30%) analyzed patients, 88 with nuclear DNA (nDNA) and 46 with mitochondrial DNA (mtDNA) variants, most of them being pediatric patients (66%), of which 77% were identified in nDNA and 23% in mtDNA. The molecular analysis of this cohort revealed 72 already described pathogenic and 20 novel, probably pathogenic, variants, as well as 62 variants of unknown significance. For this cohort of patients with suspected MDs, the use of a customized gene panel provided a molecular diagnosis in a timely and cost-effective manner. Patients who cannot be diagnosed after this initial approach will be further selected for whole-exome sequencing. Conclusion: As a national laboratory for the study and research of MDs, we demonstrated the power of NGS to achieve a molecular etiology, expanding the mutational spectrum and proposing accurate genetic counseling in this group of heterogeneous diseases without therapeutic options.

First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9  GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36  GeV/c^{2}, rejecting cross sections above 9.2×10^{-48}  cm at the 90% confidence level.

Profiling cardiac fibroblasts in regenerative hearts after myocardial infarction

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Fundação para a Ciência e Tecnologia (FCT)

Introduction

Mouse neonates at postnatal day 1 (P1) are able to regenerate their hearts after myocardial infarction (MI) by reactivating cardiomyocyte proliferation and neovascularization, with little to no fibrosis. However, this process is transient and 7 day-old animals develop a reparative response as observed in adults [1]. After MI, these animals undergo permanent loss of myocardial tissue that is replaced by a rigid fibrotic scar to avoid organ rupture, having devastating consequences for heart function. Although the role of cardiac fibroblasts (CF) - the main orchestrators of fibrosis – in adults is well-documented, no study has unveiled the role of CF during neonatal regeneration. Recent work from our group showed that at least a subset of neonatal CF is able to provide pro-regenerative cues to cardiomyocytes, pointing to a beneficial role of CF in MI resolution.

Purpose

The ultimate goal of our research is to unravel CF-mediated mechanisms that confer regenerative potential to the neonate and re-activate these processes in the adult.

Methods

Mouse ventricles from E16, P1, P3 and P7 mice were subjected to targeted RNA-sequencing. To unveil non-myocyte cell dynamics in the first week after injury in regenerative (P1) hearts, myocardial infarction (MI) was induced by permanent ligation of the left descending coronary artery. To specifically assess the impact of CF in heart regeneration, a Tcf21iCre knock-in mouse line, carrying the diphtheria toxin receptor, was generated, rendering Tcf21+ CF - the majority of CF in the heart - susceptible to diphtheria toxin.

Results

Transcriptional profiling around birth highlighted severe extracellular matrix (ECM) changes from regenerative (P1) to reparative stages (P7). Coherently, from P1 to P7 CF were found to populate the myocardium and undergo a phenotypic shift that explained the transcriptional alterations observed for ECM-encoding genes, indicating a role of CF in the regeneration to repair transition. After MI at P1, CF were found to be readily and transiently recruited to the ischemic site, peaking at day 5 post-MI and returning to basal levels at day 7, a period in which cardiomyocyte proliferation and neovascularization were up-regulated. Of note, no evidence was found of fibrotic tissue or myofibroblasts from 7 days post-MI onwards. Contrarily, MI at P7 resulted permanent loss of cardiomyocytes, impaired neovascularization and formation of aberrant fibrosis as a result from exuberant and persistent fibroblast recruitment and activation. To evaluate the functional impact of fibroblast ablation during the regenerative response, ablation of Tcf21+ CF was performed after MI at P1. CF removal resulted impaired cardiac cell proliferation, indicating that CF recruited after MI are essential for effective neonatal regeneration.

Conclusion

After birth, CF undergo a switch from a regenerative to reparative phenotype that contributes to the loss of regenerative capacity after birth.

Expert range maps of global mammal distributions harmonised to three taxonomic authorities

AIM

Comprehensive, global information on species' occurrences is an essential biodiversity variable and central to a range of applications in ecology, evolution, biogeography and conservation. Expert range maps often represent a species' only available distributional information and play an increasing role in conservation assessments and macroecology. We provide global range maps for the native ranges of all extant mammal species harmonised to the taxonomy of the Mammal Diversity Database (MDD) mobilised from two sources, the Handbook of the Mammals of the World (HMW) and the Illustrated Checklist of the Mammals of the World (CMW).

LOCATION

Global.

TAXON

All extant mammal species.

METHODS

Range maps were digitally interpreted, georeferenced, error-checked and subsequently taxonomically aligned between the HMW (6253 species), the CMW (6431 species) and the MDD taxonomies (6362 species).

RESULTS

Range maps can be evaluated and visualised in an online map browser at Map of Life (mol.org) and accessed for individual or batch download for non-commercial use.

MAIN CONCLUSION

Expert maps of species' global distributions are limited in their spatial detail and temporal specificity, but form a useful basis for broad-scale characterizations and model-based integration with other data. We provide georeferenced range maps for the native ranges of all extant mammal species as shapefiles, with species-level metadata and source information packaged together in geodatabase format. Across the three taxonomic sources our maps entail, there are 1784 taxonomic name differences compared to the maps currently available on the IUCN Red List website. The expert maps provided here are harmonised to the MDD taxonomic authority and linked to a community of online tools that will enable transparent future updates and version control.

Elucidating the role of Cavin1 in drug-induced long QT syndrome (diLQTS)

Introduction

Several drugs can induce QT prolongation by altering cardiac ion currents, notably IKr. The cardiotoxic response to a drug is however extremely variable between individuals, ranging from no impact to life-threatening ventricular arrhythmias. The molecular mechanisms underlying this variability remain unclear. Previously, we reported higher expression levels of Cavin1, an essential protein for caveolae formation, in cardiomyocytes (CM) derived from patients with high susceptibility to develop sotalol-induced long QT.

Purpose

We aimed to explore whether Cavin1 could sway the cardiac repolarization response to drugs.

Method

We used induced pluripotent stem cells-derived CM (iPS-CM) from two subjects with the highest sensitivity (HS) to sotalol (ie, those with the highest increase in QTc) and two individuals with the lowest sensitivity to sotalol (LS) to perform molecular and electrophysiological investigations.

Results

At baseline, no differences in terms of repolarization durations, IKr amplitude, and ion channel expression were noted between the HS- and the LS-iPS-CM. However, the HS-iPS-CM displayed significant prolongation in action potential and field potential (FPD) durations after the application of 30 and 50μM of sotalol. They also displayed higher sensitivity to other drugs targeting hERG (E4031, vandetanib, and clarithromycin). Cavin1 mRNA and protein levels were increased by 2 fold in the HS-iPS-CM as compared to the LS-iPS-CM. Overexpressing Cavin1 in the LS-iPS-CM using adenovirus induced a higher sensitivity to sotalol as only 10μM was sufficient to induce 12% longer FPD. Consistently, the infection with Cavin1 increased the sensitivity of LS-CM to the other hERG blockers. In contrast, siRNA against Cavin1 reduced its expression by 60% in HS iPS-CM and switched their phenotype to a lower sensitivity to sotalol and the other hERG blockers. Interestingly, in line with the shortening of the FPD in LS-iPS-CM, overexpressing Cavin1 increased hERG expression in isolated membrane fraction from HEK cells stably expressing KCNH2. This suggests a role of Cavin1 in modulating hERG trafficking/recycling to the membrane and thereby the number of channels that can be blocked by drugs.

Conclusion

Altogether, this work identified Cavin1 as a novel modulator of cardiomyocyte response to hERG blockers and a potential risk factor for diLQT. Further understanding of its contribution may pave the way for personalized drug prescription to avoid undesirable cardiotoxicity.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Leducq

Benefits of two twelve-week multimodal programs on reaction time in community dwellings at risk of falling: preliminary results

Background

A slower reaction time (RT) performance is considered a risk factor for falls. Different approaches as a psychomotor intervention (involving neuromotor exercises) or the whole-body vibration (inducing neurophysiological changes) may reduce the risk of falls. Nevertheless, a combined program may promote greater gains. This study aimed to investigate the acceptability and the effect of two multimodal programs on RT in community-dwelling older adults fallers or balance-impaired.

Methods

A total of 37 participants (74.3 ± 5.2 years) were divided into two groups (3x/week): experimental group 1 (psychomotor intervention); experimental group 2 [EG2] (combined program: psychomotor intervention + whole-body vibration). The Deary-Liewald reaction time task assessed RT. Simple and choice reaction time [CRT] (ms) tasks were recorded under single and dual-task (DT) paradigms. DT cost was also computed.

Results

The attendance rate was 86.3%. Wilcoxon test comparisons revealed significant differences between baseline and post-intervention evaluations in the EG2. The improvement was observed in the variable ‘CRT-DT’, in which participants spent less time to perform the task (1026.0 ± 153.4 vs. 960.4 ± 160.9, P = 0.040). The correspondent effect size was medium (r = 0.33). The DT cost was also decreased in CRT-DT by 3.9%. No significant differences between groups were found.

Conclusions

This study demonstrated that both programs were safe and highly attended. The results suggest that a combined intervention (psychomotor intervention + whole-body vibration) should be privileged to improve RT and reduce the risk of falls. Trial Registration: ClinicalTrials.gov Identifier: NCT03446352. Funding: This study was supported by the ESACA Project (Grant ALT20-03-0145-FEDER-000007) and by FCT (SFRH/BD/147398/2019).

Novel approaches to reduce the risk of falling in community dwellings: effects of two multimodal programs in lower-body strength—a pilot study

Background

Muscle weakness is a key risk factor for falls and strength exercises should be included in fall prevention programs. A psychomotor intervention promoting motor stimulation and the whole-body vibration (WBV) providing muscle contractions may reduce the incidence of falls. Our hypothesis relies on the greater benefits of a combined program. This study aimed to evaluate the effectiveness and the feasibility of two 12-week multimodal programs in lower-body strength in community dwellings fallers or with balance impairment.

Methods

Thirty-seven participants (34 women; mean age 74.3 ± 5.2 years) were allocated into: experimental group 1 [EG1] (psychomotor intervention), or experimental group 2 [EG2] (combined program: psychomotor intervention plus WBV), 3x/week. Maximal strength of knee extensors and flexors was assessed by an isokinetic dynamometer at 60°/s. Wilcoxon and Mann-Whitney tests were performed.

Results

The overall adherence rate was high (86.3%), with a level intensity in the rating of perceived exertion of 12.1 ± 0.3 points, in EG1, and 12.5 ± 0.4 points, in EG2. Significant changes between the pre-post intervention were observed exclusively in EG2, in the variables ‘Peak torque extension’ (71.7 ± 28.6 Nm vs. 79.2 ± 23.5 Nm, P = 0.042) and ‘Agonist/Antagonist ratio’ (60.2 ± 13.0 vs. 53.5 ± 8.6, P = 0.013). The effect size (r) in both variables was medium. No significant changes between groups were detected.

Conclusions

This pilot results indicate that both programs were feasible and well-tolerated. The combined program demonstrates larger effectiveness, since the WBV may positively influence the lower-body strength, reducing the risk of falls. Trial Registration: ClinicalTrials.gov Identifier: NCT03446352. Funding: This pilot was granted by the ESACA Project (Grant ALT20-03-0145-FEDER-000007) and by FCT (SFRH/BD/147398/2019).

Hopelessness in patients with schizophrenia

Introduction

Individuals with schizophrenia have a shortened average life expectancy, with a lifetime risk of suicide around 5%.

Objectives

Here we present a case of a patient diagnosed with schizophrenia who developed depressive symptoms with suicidal ideation, reactive to psychotic symptoms. Considering this specific case, the factors that contribute to the increased risk of suicide in these patients are reviewed.

Methods

Relevant clinical information was extracted from the patient’s clinical process. In addition, we searched Pubmed^R database with the terms “Schizophrenia”, “Hopelessness” and “Suicide”.

Results

A 40-year-old male patient, single and unemployed presents a progressive psychotic condition, with 20 years of evolution, with an impact on social and work behaviour. As a background he has a history of depressive episodes with suicidal ideation at the age of 36, following psychotic symptoms. This is a patient with preserved cognitive functioning combined with a high level of education, who understands the impact of his reality on his functioning. In this context, he develops feelings of hopelessness, that are the risk factor for suicide, most consistently reported in patients with schizophrenia.

Conclusions

This case assesses a patient with schizophrenia who has several factors, that contribute to an increased risk of suicide, focusing on hopelessness. In the future, it may be interesting to study in more detail the individual weight of each factor, so that it is possible to accurately predict the individual risk of each patient and, consequently, it is possible to implement preventive strategies.

Exome sequencing detected an extremely rare case of foetal onset familial haemophagocytic lymphohistiocytosis type 5 presenting with hydrops foetalis

Background

Familial hemophagocytic lymphohistiocytosis (FHL) is a genetically heterogeneous autosomal recessive hyper-inflammatory syndrome which needs early accurate diagnosis and appropriate treatment to prevent complications and early mortality. Recently, it was reported that mutations in STXBP2 gene are linked to FHL type 5 (FHL-5).

Case Presentation

We report a Sri Lankan neonate who presented with low Apgar scores at birth, abdominal distension, and hepatosplenomegaly, followed by lethargy, poor sucking and rapid decompensation with wide spread activation of inflammation within 48 h of birth. Her elder sibling also had a similar presentation during early neonatal period and deceased at two weeks of age with no diagnosis. Unfortunately, the index case deceased at 14 days of age following multi-organ dysfunction and severe metabolic acidosis. Targeted gene panel followed by reflex exome sequencing revealed a novel likely pathogenic homozygous variant in the STXBP2 gene (NM_001272034.1:c.1141-2A > G) which confirmed the diagnosis of autosomal recessive FHL-5.

Conclusion

Early diagnosis of FHL type 5 using genetic analysis and timely treatment are difficult in the absence of family history due to a wide spectrum of clinical manifestations. However both early diagnosis and treatment doesn’t alter the long term prognosis. So genetic counselling would be the better option.

Forssman Prevalence in a Portuguese Donor Population

Introduction Discovered in 1911 by Frederick Forssman, the Forssman (Fs) antigen (Ag) expression varies among species, being rarely present on human red blood cells (RBC). In 1987 three unrelated English families were identified with a phenotype designed Apae which was later classified as the 31st blood group: FORS. Since antibodies (Ab) anti-Fs has natural occurrence and the expression of the Ag occurs on the surface of the RBC, body fluids and organs, raises a potential role for this antigen in transfusion and transplantation implications.

Objectives Our main goals were to evaluate the prevalence of anti-Fs Ab and clarify its impact in transfusional medicine by classifying the type of immunoglobulin (Ig) involved.

Methodology 3-5% sheep RBC suspension with positive expression for Fs Ag was used to evaluate the presence of Ab anti-Fs in plasma samples from a Portuguese population of blood donor and classify the immunoglobulin involved. Standard tube technique was used in all the experiments.

Results From a total of 11877 donors, 117 (0,99%) showed weak reactions (between 0 and 1 in a scale from 0 to 4). All these samples would be further studied to evaluate the presence of the Arg296Gln in the GBGT1 gene. Also, from the 192 samples studied to classify the Ab involved, 52% revealed to be only IgM, being the rest a mixture between IgG and IgM.

Conclusion The population studied revealed few samples with negative reaction against the sheep RBC confirm the low-prevalence of this blood group. The majority from the Ab to be IgM was also corroborated although the presence of an IgG portion can be clinically significant once it can cross the placental barrier.

Associations of socioeconomic and health related factors with fall risk on community dwelling older adults from Alentejo

Introduction With the world, population ageing falls become a problem. Portugal follows this tendency, particularly in Alentejo. Ecological models evidence that biological, behaviour and socioeconomic factors explain falls. However, the role of socioeconomic and health-related factors on the risk of falls is not well known.

Objectives To analyse the association of socioeconomic and health-related factors with fall risk on community-dwelling older adults from Alentejo.

Methodology This observational study involved 384 community-dwelling older adults (73.6 ± 6.0 years), the minimal sample size calculated by Open Epi Online program, of whom 40.6% fell at least once in the previous year. Sociodemographic characteristics (age, gender, marital status, schooling, retirement age, living alone and yield) and health-related factors (number of health conditions, cognitive state, fat mass %, physical activity, and depression index) were accessed.

Results Univariate Regression Logistic showed that gender was the only sociodemographic characteristics which significantly explains falls occurrence, in which to be woman increases the likelihood of falling on 96% (OR: 1.96, p < 0.05). As regard health-related factors, results show that for each additional health condition the likelihood of falling increased 17%, for each additional 1% on fat mass this likelihood increased 4%, and for each additional point on depression index this likelihood increased 15.1% (OR: 1.04 to 1.17, p < 0.05).

Conclusion Health-related factors showed to be more preponderant in the occurrence of falls compared to socio-demographic characteristics. Women with more chronic conditions increased fat mass, and high depression index will be the most susceptible to falls. Thus, preventive measures should play particular attention to these persons.

Twelve-week multimodal programs can improve dual-task performance in risk factors for falls in community-dwelling older adults: a pilot study

Introduction Performing a dual-task (DT), mainly while walking and performing another task simultaneously, is seen as determinants factors for falls and injuries in older adults. A psychomotor intervention relying on the prevention of sensorimotor and neurocognitive deterioration may prevent falls. The whole-body vibration (WBV) promotes the increase of agility, reducing the risk of falling. However, an intervention that combines both methods can lead to additional benefits, particularly as regards DT.

Objectives To evaluate the feasibility and the effect of two multimodal programs designed for community-dwelling older adults, fallers or at high risk of falling, on DT performance ability.

Methodology Thirty-seven participants (74.3±5.2 years) were randomly assigned into experimental group 1 [EG1] (psychomotor intervention); or experimental group 2 [EG2] (psychomotor intervention + WBV). DT performance (TUGcog) was assessed by the Timed Up and Go Test (s) performed simultaneously with the counting backward cognitive task.

Results Adherence rate was 86.3%. Wilcoxon test comparisons showed improvements from baseline to post-intervention on EG1 (time (s): 10.1±2.7 vs. 9.0±2.7, p = 0.001; cognitive stops (n): 0.9±1.0 vs. 0.2±0.4, p = 0.012; motor stops (n): 0.3±0.5 vs. 0.0±0.0, p = 0.025), corresponding to an effect size (cohen’s d) ranging from 0.41 (small) to 0.92 (medium) and on EG2 (time (s): 9.9±2.5 vs. 8.5±1.8, p = 0.010; cognitive stops (n): 1.1±0.7 vs. 0.4±0.5, p = 0.004), corresponding to a d ranging from 0.64 (medium) to 1.15 (medium). There were no significant differences between groups.

Conclusion These preliminary results suggested that the multimodal programs were feasible and effective in reducing the risk of falling by improving the determinant risk factor DT performance. Trial Registration: ClinicalTrials.gov Identifier: NCT03446352. Funding: This study was funded by ESACA Project (Grant ALT20-03-0145-FEDER-000007) and by FCT (SFRH/BD/147398/2019).

No man is an island: spatial clustering and access to primary care as possible targets for the development of new community mental health approaches

BACKGROUND

to understand if patients seen at Centro Hospitalar Psiquiátrico de Lisboa (CHPL) live in geographical clusters or randomly throughout the city, as well as determine their access to the psychiatric hospital and primary care facilities (PCF).

METHODS

spatial autocorrelation statistics were performed (queen criterion of contiguity), regarding all patients observed at CHPL in 2017 (at the census subsection level), and considering not only their overall number but also main diagnosis, and admission to the psychiatric ward - voluntary or compulsory. Distance to the hospital and to the closest PCF was measured (for each patient and the variables cited above), and the mean values were compared. Finally, the total number of patients around each PCF was counted, considering specified radius sizes of 656 and 1000 m.

RESULTS

All 5161 patients (509 psychiatric admissions) were geolocated, and statistical significance regarding patient clustering was found for the total number (p-0.0001) and specific group of disorders, namely Schizophrenia and related disorders (p-0.007) and depressive disorders (p-0.0002). Patients who were admitted in a psychiatric ward live farther away from the hospital (p-0.002), with the compulsory admissions (versus voluntary ones) living even farther (p-0.004). Furthermore, defining a radius of 1000 m for each PCF allowed the identification of two PCF with more than 1000 patients, and two others with more than 800.

CONCLUSIONS

as patients seem to live in geographical clusters (and considering PCFs with the highest number of them), possible locations for the development of programs regarding mental health treatment and prevention can now be identified.

Pru p 3 sublingual immunotherapy ultra-rush protocol is safe and clinically effective

Summary

Introduction. Sublingual immunotherapy (SLIT) with Pru p 3 can prevent severe allergic reactions to LTP-containing foods, but the standard initiation protocol is time-consuming. Objectives. Establish the safety of a novel ultra-rush initiation protocol for SLIT with Pru p 3. Methods. Prospective study comparing the side effects of the standard vs novel ultra-rush initiation protocols of SLIT with Pru p 3 in patients with anaphylaxis to LTP. Results. Fifteen patients were included (standard initiation, 5; ultra-rush initiation, 10), 80% females. All patients had oropharyngeal pruritus during initiation, 80% with spontaneous recovery, but no other gastro-intestinal, respiratory, cutaneous or systemic side effects occurred in any patient of both groups. Conclusion. The novel ultra-rush protocol halved the build-up time without increasing side effects.

Fe3O4@Au nanoparticles-based magnetoplatform for the HMGA maize endogenous gene electrochemical genosensing

This work addresses a technological advance applied to the construction of a magnetogenoassay with electrochemical transduction for the maize taxon-specific (HMGA gene) detection using gold-coated magnetic nanoparticles as nanosized platform. Superparamagnetic core-shell Fe₃O₄@Au nanoparticles (10.4 ± 1.7 nm) were used to assemble the genoassay through the covalent immobilization of HMGA DNA probes onto carboxylated self-assembled monolayers at the nanoparticles surface. A hybridization reaction using sandwich format was selected to prevent inefficient hybridization connected with stable secondary DNA structures using also fluorescein isothiocyanate as DNA signaling tag. The labelling of the hybridization reaction with enzymes allowed the chronoamperometric measurement of the peroxidase activity linked to the nanoplatform located on gold surface. Using this electrochemical magnetogenoassay a linear concentration range from 0.5 to 5 nM and a LOD of 90 pM with a RSD <1.2% was calculated. Certified maize was evaluated without further purification after PCR amplification. This work highlights the efficacy of the electrochemical magnetogenoassay for the HMGA detection, showing its potential as alternative procedure for the verification of the compliance of the legislation.