Genetic risk factors and COVID-19 severity in Brazil: results from BRACOVID study.

The coronavirus disease 2019 (COVID-19) pandemic has changed the paradigms for disease surveillance and rapid deployment of scientific-based evidence for understanding disease biology, susceptibility and treatment. We have organized a large-scale genome-wide association study (GWAS) in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected individuals in Sao Paulo, Brazil, one of the most affected areas of the pandemic in the country, itself one of the most affected in the world. Here, we present the results of the initial analysis in the first 5233 participants of the BRACOVID study. We have conducted a GWAS for COVID-19 hospitalization enrolling 3533 cases (hospitalized COVID-19 participants) and 1700 controls (non-hospitalized COVID-19 participants). Models were adjusted by age, sex and the 4 first principal components. A meta-analysis was also conducted merging BRACOVID hospitalization data with the Human Genetic Initiative (HGI) Consortia results. BRACOVID results validated most loci previously identified in the HGI meta-analysis. In addition, no significant heterogeneity according to ancestral group within the Brazilian population was observed for the two most important COVID-19 severity associated loci: 3p21.31 and Chr21 near IFNAR2. Using only data provided by BRACOVID, a new genome-wide significant locus was identified on Chr1 near the genes DSTYK and RBBP5. The associated haplotype has also been previously associated with a number of blood cell related traits and might play a role in modulating the immune response in COVID-19 cases.

Multi-ancestry genome-wide gene-sleep interactions identify novel loci for blood pressure.

Long and short sleep duration are associated with elevated blood pressure (BP), possibly through effects on molecular pathways that influence neuroendocrine and vascular systems. To gain new insights into the genetic basis of sleep-related BP variation, we performed genome-wide gene by short or long sleep duration interaction analyses on four BP traits (systolic BP, diastolic BP, mean arterial pressure, and pulse pressure) across five ancestry groups in two stages using 2 degree of freedom (df) joint test followed by 1df test of interaction effects. Primary multi-ancestry analysis in 62,969 individuals in stage 1 identified three novel gene by sleep interactions that were replicated in an additional 59,296 individuals in stage 2 (stage 1 + 2 Pjoint < 5 × 10-8), including rs7955964 (FIGNL2/ANKRD33) that increases BP among long sleepers, and rs73493041 (SNORA26/C9orf170) and rs10406644 (KCTD15/LSM14A) that increase BP among short sleepers (Pint < 5 × 10-8). Secondary ancestry-specific analysis identified another novel gene by long sleep interaction at rs111887471 (TRPC3/KIAA1109) in individuals of African ancestry (Pint = 2 × 10-6). Combined stage 1 and 2 analyses additionally identified significant gene by long sleep interactions at 10 loci including MKLN1 and RGL3/ELAVL3 previously associated with BP, and significant gene by short sleep interactions at 10 loci including C2orf43 previously associated with BP (Pint < 10-3). 2df test also identified novel loci for BP after modeling sleep that has known functions in sleep-wake regulation, nervous and cardiometabolic systems. This study indicates that sleep and primary mechanisms regulating BP may interact to elevate BP level, suggesting novel insights into sleep-related BP regulation.

Blockchain-Based Architecture Design for Personal Health Record: Development and Usability Study.

BACKGROUND: The importance of blockchain-based architectures for personal health record (PHR) lies in the fact that they are thought and developed to allow patients to control and at least partly collect their health data. Ideally, these systems should provide the full control of such data to the respective owner. In spite of this importance, most of the works focus more on describing how blockchain models can be used in a PHR scenario rather than whether these models are in fact feasible and robust enough to support a large number of users. OBJECTIVE: To achieve a consistent, reproducible, and comparable PHR system, we build a novel ledger-oriented architecture out of a permissioned distributed network, providing patients with a manner to securely collect, store, share, and manage their health data. We also emphasize the importance of suitable ledgers and smart contracts to operate the blockchain network as well as discuss the necessity of standardizing evaluation metrics to compare related (net)works. METHODS: We adopted the Hyperledger Fabric platform to implement our blockchain-based architecture design and the Hyperledger Caliper framework to provide a detailed assessment of our system: first, under workload, ranging from 100 to 2500 simultaneous record submissions, and second, increasing the network size from 3 to 13 peers. In both experiments, we used throughput and average latency as the primary metrics. We also created a health database, a cryptographic unit, and a server to complement the blockchain network. RESULTS: With a 3-peer network, smart contracts that write on the ledger have throughputs, measured in transactions per second (tps) in an order of magnitude close to 102 tps, while those contracts that only read have rates close to 103 tps. Smart contracts that write also have latencies, measured in seconds, in an order of magnitude close to 101 seconds, while that only read have delays close to 100 seconds. In particular, smart contracts that retrieve, list, and view history have throughputs varying, respectively, from 1100 tps to 1300 tps, 650 tps to 750 tps, and 850 tps to 950 tps, impacting the overall system response if they are equally requested under the same workload. Varying the network size and applying an equal fixed load, in turn, writing throughputs go from 102 tps to 101 tps and latencies go from 101 seconds to 102 seconds, while reading ones maintain similar values. CONCLUSIONS: To the best of our knowledge, we are the first to evaluate, using Hyperledger Caliper, the performance of a PHR blockchain architecture and the first to evaluate each smart contract separately. Nevertheless, blockchain systems achieve performances far below what the traditional distributed databases achieve, indicating that the assessment of blockchain solutions for PHR is a major concern to be addressed before putting them into a real production.

Focal adhesion signaling: vascular smooth muscle cell contractility beyond calcium mechanisms.

Smooth muscle cell (SMC) contractility is essential to vessel tone maintenance and blood pressure regulation. In response to vasoconstrictors, calcium-dependent mechanisms promote the activation of the regulatory myosin light chain, leading to increased cytoskeleton tension that favors cell shortening. In contrast, SMC maintain an intrinsic level of a contractile force independent of vasoconstrictor stimulation and sustained SMC contraction beyond the timescale of calcium-dependent mechanisms suggesting the involvement of additional players in the contractile response. Focal adhesions (FAs) are conceivable candidates that may influence SMC contraction. They are required for actin-based traction employed by cells to sense and respond to environmental cues in a process termed mechanotransduction. Depletion of FA proteins impairs SMC contractility, producing arteries that are prone to dissection because of a lack of mechanical stability. Here, we discuss the role of calcium-independent FA signaling mechanisms in SMC contractility. We speculate that FA signaling contributes to the genesis of a variety of SMC phenotypes and discuss the potential implications for mechanical homeostasis in normal and diseased states.

Variant genotypes associated with reduced expression of RhCE antigens among Brazilian blood donors.

BACKGROUND: The genetic diversity of the RHCE gene locus has been explored in diverse populations of different racial backgrounds. Data referring to the diversity of RHCE encoding weakened expression of C, c, E, and e in multiethnic populations is still incomplete. METHODS: Samples from Brazilian blood donors presenting reduced expression of C, c, E, or e on gel method were selected for the study. All exons and flanking introns of RHCE were genotyped though direct Sanger sequencing for the included donors. RESULTS: Sixty-six donors were included: 23 with weak C, 22 with weak c, 6 with weak E, 14 with weak e, and 1 with weak c and E. Among the samples with weak C, the following altered RH*C were encountered: RHCE*CeMA (n = 3), RHCE*Ce941C (n = 1), and RHCE*CeVA (n = 1). RHD*D-CE(4-7)-D was detected in six cases, RHCE*CE was presumably present in five cases, and seven cases were unexplained. Two altered alleles underlay the weak c phenotype: RHCE*ceJAL (n = 20) and RHCE*ce340T (n = 2), and two altered RHCE justified weak e: RHCE*ceMO (n = 6) and RHCE*ceJAL (n = 8). Three variant RHCE were associated with weak E: RHCE*cEJU (n = 4), RHCE*cE382C (n = 1), and RHCE*cEIV (n = 1). The RHCE*cE905A justified one case of weak c and E. CONCLUSION: We describe the distribution of RHCE variants found in association with weak expression of C, c, E, and e in blood donors of multiethnic origin, which differs in comparison to that previously reported for people of African or Caucasian descent.

Phenotypical, Clinical, and Molecular Aspects of Adults and Children With Homozygous Familial Hypercholesterolemia in Iberoamerica.

OBJECTIVE: Characterize homozygous familial hypercholesterolemia (HoFH) individuals from Iberoamerica. Approach and Results: In a cross-sectional retrospective evaluation 134 individuals with a HoFH phenotype, 71 adults (age 39.3±15.8 years, 38.0% males), and 63 children (age 8.8±4.0 years, 50.8% males) were studied. Genetic characterization was available in 129 (96%). The majority (91%) were true homozygotes (true HoFH, n=79, 43.0% children, 46.8% males) or compound heterozygotes (compound heterozygous familial hypercholesterolemia, n=39, 51.3% children, 46.2% males) with putative pathogenic variants in the LDLR. True HoFH due to LDLR variants had higher total (P=0.015) and LDL (low-density lipoprotein)-cholesterol (P=0.008) compared with compound heterozygous familial hypercholesterolemia. Children with true HoFH (n=34) tended to be diagnosed earlier (P=0.051) and had a greater frequency of xanthomas (P=0.016) than those with compound heterozygous familial hypercholesterolemia (n=20). Previous major cardiovascular events were present in 25 (48%) of 52 children (missing information in 2 cases), and in 43 (67%) of 64 adults with LDLR variants. Children who are true HoFH had higher frequency of major cardiovascular events (P=0.02), coronary heart (P=0.013), and aortic/supra-aortic valve diseases (P=0.022) than compound heterozygous familial hypercholesterolemia. In adults, no differences were observed in major cardiovascular events according to type of LDLR variant. From 118 subjects with LDLR variants, 76 (64%) had 2 likely pathogenic or pathogenic variants. In 89 subjects with 2 LDLR variants, those with at least one null allele were younger (P=0.003) and had a greater frequency of major cardiovascular events (P=0.038) occurring at an earlier age (P=0.001). CONCLUSIONS: There was a high frequency of cardiovascular disease even in children. Phenotype and cardiovascular complications were heterogeneous and associated with the type of molecular defect.

Adherence to a Mediterranean diet, dyslipidemia and inflammation in familial hypercholesterolemia.

BACKGROUND AND AIMS: Familial Hypercholesterolemia (FH) is characterized by elevated LDL-cholesterol (LDL-C) and high atherosclerosis risk. The impact of different dietary patterns on atherosclerosis biomarkers has been poorly studied in FH. This study verified the association of adherence to a Mediterranean diet with biomarkers of dyslipidemia and low-grade inflammation in molecularly proven FH adults from Brazil (BR) and Spain (SP). METHODS AND RESULTS: In this cross-sectional study adherence to the Mediterranean diet was assessed by a validated score and generalized estimating equations were used to evaluate its association with plasma LDL-C, apolipoprotein-B (ApoB) and high sensitivity C-reactive protein (hs-CRP) concentrations. We included 92 (mean age 45 years, 58.7% females) and 98 FH individuals (mean age 46.8 years, 60.2% females) respectively from BR and SP. FH causing variants did not differ between countries. LDL-C, ApoB and hs-CRP concentrations were higher in BR than in SP: 179 (135-250) and 161 (133-193) mg/dL; 141 (109-181) and 103 (88-134) mg/dL; and 1.6 (0.8-4.0) and 0.8 (0.4-1.5) mg/L respectively (all p < 0.001). Most of BR had low adherence (n = 77, 83.7%), while the majority of SP were divided into moderate (n = 35, 35.7%) and strong adherence to the Mediterranean diet (n = 37, 37.8%), p < 0.001. There was a significant inverse association of adherence to the Mediterranean diet score with higher LDL-C, ApoB, and hs-CRP after adjusting for socio economic parameters, caloric and fatty acid intakes as well as pharmacological lipid lowering therapies. CONCLUSIONS: Higher adherence to a Mediterranean diet was associated with better dyslipidemia and low-grade inflammation profiles in FH.

Metabolomic Evaluation of Chronic Periodontal Disease in Older Adults.

Periodontal disease is an infectious inflammatory disease related to the destruction of supporting tissues of the teeth, leading to a functional loss of the teeth. Inflammatory molecules present in the exudate are catalyzed and form different metabolites that can be identified and quantified. Thus, we evaluated the inflammatory exudate present in crevicular fluid to identify metabolic biological markers for diagnosing chronic periodontal disease in older adults. Research participants were selected from long-term institutions in Brazil. Participants were individuals aged 65 years or older, healthy, or with chronic periodontal disease. Gas chromatography/mass spectrometry was used to evaluate potential biomarkers in 120 crevicular fluid samples. We identified 969 metabolites in the individuals. Of these, 15 metabolites showed a variable importance with projection score > 1 and were associated with periodontal disease. Further analysis showed that among the 15 metabolites, two (5-aminovaleric acid and serine, 3TMS derivative) were found at higher concentrations in the crevicular fluid, indicating their potential diagnostic power for periodontal disease in older adults. Our findings indicated that some metabolites are present at high concentrations in the crevicular fluid in older adults with periodontal disease and can be used as biomarkers of periodontal disease.

Electrical stimulation applied during differentiation drives the hiPSC-CMs towards a mature cardiac conduction-like cells.

Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) resemble fetal cardiomyocytes and electrical stimulation (ES) has been explored to mature the differentiated cells. Here, we hypothesize that ES applied at the beginning of the differentiation process, triggers both differentiation of the hiPSC-CMs into a specialized conduction system (CS) phenotype and cell maturation. We applied ES for 15 days starting on day 0 of the differentiation process and found an increased expression of transcription factors and proteins associated with the development and function of CS including Irx3, Nkx2.5 and contactin 2, Hcn4 and Scn5a, respectively. We also found activation of intercalated disc proteins (Nrap and ß-catenin). We detected ES-induced CM maturation as indicated by increased Tnni1 and Tnni3 expression. Confocal micrographs showed a shift towards expression of the gap junction protein connexin 40 in ES hiPSC-CM compared to the more dominant expression of connexin 43 in controls. Finally, analysis of functional parameters revealed that ES hiPSC-CMs exhibited faster action potential (AP) depolarization, longer intracellular Ca2+ transients, and slower AP duration at 90% of repolarization, resembling fast conducting fibers. Altogether, we provided evidence that ES during the differentiation of hiPSC to cardiomyocytes lead to development of cardiac conduction-like cells with more mature cytoarchitecture. Thus, hiPSC-CMs exposed to ES during differentiation can be instrumental to develop CS cells for cardiac disease modelling, screening individual drugs on a precison medicine type platform and support the development of novel therapeutics for arrhythmias.

Low rate of life-threatening events and limitations in predicting invasive and noninvasive markers of symptoms in a cohort of type 1 Brugada syndrome patients: Data and insights from the GenBra registry.

BACKGROUND: Brugada syndrome (BrS) has diagnostic challenges and controversial risk assessment. We aimed to investigate invasive and noninvasive parameters in symptomatic and asymptomatic patients from a Brazilian cohort of type-1 BrS. METHODS: Patients with spontaneous and drug-induced type-1 BrS were classified into two groups, asymptomatic (n = 116, 84.1%) and symptomatic (n = 22, 15.9%; 13 with arrhythmogenic syncope, 9 with aborted sudden cardiac death). Genetic testing, EPS parameters, and electrocardiogram (ECG) parameters were analyzed. RESULTS: A total of 138 consecutive patients were eligible, 101 men (73.2%), mean 41.4 years, mostly probands (79%). Spontaneous pattern, observed in 77.5% of the patients, was associated with symptoms only if expressed in V1 and V2 standard position (not high precordial leads; p = .014). All symptomatic patients were probands. The presence of right ventricular outflow tract conduction delay (RVOTcd) signs, positive EPS, and SCN5A status was similar between symptomatic and asymptomatic subjects. During the mean 75-month follow-up, eight patients had appropriate therapies. All had spontaneous type-1 ECG pattern and 2/8 (25%) were asymptomatic, with positive EPS. The overall LAE incidence of 1.1% per year dropped to 0.27% in asymptomatic patients. RVOTcd occurred more frequently in SCN5A carriers (QRS-f 33.3% vs. 7.7%; p = .005, AVR sign 58.3% vs. 13.6%; p < .001; deep S in lead I 75% vs. 48.5%, p = .025%), as well as longer HV interval (66 vs. 49 ms; p < .001). CONCLUSIONS: Spontaneous type-1 Brugada pattern in standard leads and proband status were more frequent in symptomatic subjects. RVOTcd, more common in SCN5A carriers, did not predict symptoms in BrS patients. EPS exhibited limited prognostic value for this low-risk population.